Management capacity within small and medium tourism enterprises (SMTEs)
- Authors: Mxunyelwa, Siyabonga
- Date: 2019
- Subjects: Small business -- South Africa -- Eastern Cape -- Management , Tourism -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/41708 , vital:36574
- Description: The small to medium tourism enterprises are identified as important contributors to the growth of the local and regional economies and creates much needed entrepreneurial ventures. Universally, small to medium tourism enterprises play a significant role in the tourism sector. The small businesses are in many instances deemed to facing risk to economic environmental challenges and face uphill battles to operate their enterprises in a sustainable manner. Management of these enterprises by owners and managers seems to face challenges. This study focuses on small to medium tourism enterprises in the Eastern Cape Province, South Africa, which faces the triple threat challenges of poverty, inequality and unemployment, and is one of the economically poorest provinces of South Africa. In an endeavour to create a trajectory for progression and development of small to medium tourism enterprises, owners and managers are required to undertake management capacity programmes to deal with the problems that confront the enterprise on a daily basis. The study examines the factors impacting on management capacity with specific focus on the small to medium tourism enterprises in the Eastern Cape Province, South Africa. Management capacity is paramount as it builds managerial competency and has become significant to the small business economy, as these enterprises make every effort to avoid discontinuation. Management capacity improves business performance and small enterprises require help in order to have a broader understanding of issues that can be an impediment to address the challenges in the business environment. The factors that could impact on management capacity within the enterprises are the focus of this research. The eleven main factors were identified, namely skills development; reasons for starting a business; business challenges; strategic and management knowledge; business leadership; business resources, business environment; business communication; business organisational leadership; organisational strategy; and organisational information factors. Furthermore, the study examined the level of influence of these factors on the management capacity of small businesses in the tourism and hospitality sector in the Eastern Cape and investigated the relationships between these factors. A descriptive research design and a quantitative approach were considered suitable for this study. A systematic random sampling technique was utilised to choose a sample of 320 business respondents from the 2012 database of the Eastern Cape Parks and Tourism Agency, comprising of formally registered small tourism businesses. A total of 310 usable questionnaires was finally obtained. In this study descriptive and inferential statistics were applied. Descriptive statistics were captured to highlight the owners and managers’ general characteristics and to consolidate their measurement scores. Utilising inferential statistics, the study undertook an investigation into relationships between demographic variables and business characteristics. Furthermore, an investigation of the relationships amongst the following factors: skills development; reasons for starting a business; business challenges; strategic and management knowledge; business leadership; business resources, business environment; business communication; business organisational leadership; organisational strategy and organisational information factors was undertaken. Data were subjected to exploratory factor analysis and both the validity and reliability of the research instrument was assessed. The research findings support an overall significant correlation between management capacity and skills development; reasons for starting a business; business challenges; strategic and management knowledge; business leadership; business resources, business environment; business communication; business organisational leadership; organisational strategy and organisational information. The study also explored the relationship between demographics and business characteristics. A significant relationship was found between business characteristics and variables in the demographic profile, namely the gender of owners/managers, educational levels, qualifications, and gross annual turnover. What follows is a summation of the most significant contributions of this research. The overview of the significance of the tourism sector in the economy and the role of small businesses in the tourism and hospitality industry of the Eastern Cape will benefit researchers and potential owners/managers who have an interest in this developing sector. The study enhances the understanding of the factors that relate to management capacity. The study has established a profile of SMTE sector in the Eastern Cape, South Africa, which can play a significant role for future research. This research makes a contribution to the largely under-researched area of management capacity in small to medium tourism enterprises. Recommendations for owners/managers and consideration of future research included the following. Owners/managers need to have management skills and a strong strategic focus. Through management capacity the needs of the business will be addressed, and capacity building programmes can be tailored to maximise the benefits for owners/managers of SMTEs, thereby improving business performance and avoiding high failure rate. Managers need to be effectively trained to deal with business needs. The management of the business plays a pivotal role in the performance of the enterprise. Managers must be skilled with regards to developing strategic plans, marketing plans, and business plans, thus enhancing management capacity. Longitudinal studies can be undertaken to investigating the same factors which could impact on management capacity. It is recommended that this study be replicated across the global spectrum in order to analyse the factors that impact on management capacity of small to medium tourism businesses of other countries.
- Full Text:
- Date Issued: 2019
- Authors: Mxunyelwa, Siyabonga
- Date: 2019
- Subjects: Small business -- South Africa -- Eastern Cape -- Management , Tourism -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/41708 , vital:36574
- Description: The small to medium tourism enterprises are identified as important contributors to the growth of the local and regional economies and creates much needed entrepreneurial ventures. Universally, small to medium tourism enterprises play a significant role in the tourism sector. The small businesses are in many instances deemed to facing risk to economic environmental challenges and face uphill battles to operate their enterprises in a sustainable manner. Management of these enterprises by owners and managers seems to face challenges. This study focuses on small to medium tourism enterprises in the Eastern Cape Province, South Africa, which faces the triple threat challenges of poverty, inequality and unemployment, and is one of the economically poorest provinces of South Africa. In an endeavour to create a trajectory for progression and development of small to medium tourism enterprises, owners and managers are required to undertake management capacity programmes to deal with the problems that confront the enterprise on a daily basis. The study examines the factors impacting on management capacity with specific focus on the small to medium tourism enterprises in the Eastern Cape Province, South Africa. Management capacity is paramount as it builds managerial competency and has become significant to the small business economy, as these enterprises make every effort to avoid discontinuation. Management capacity improves business performance and small enterprises require help in order to have a broader understanding of issues that can be an impediment to address the challenges in the business environment. The factors that could impact on management capacity within the enterprises are the focus of this research. The eleven main factors were identified, namely skills development; reasons for starting a business; business challenges; strategic and management knowledge; business leadership; business resources, business environment; business communication; business organisational leadership; organisational strategy; and organisational information factors. Furthermore, the study examined the level of influence of these factors on the management capacity of small businesses in the tourism and hospitality sector in the Eastern Cape and investigated the relationships between these factors. A descriptive research design and a quantitative approach were considered suitable for this study. A systematic random sampling technique was utilised to choose a sample of 320 business respondents from the 2012 database of the Eastern Cape Parks and Tourism Agency, comprising of formally registered small tourism businesses. A total of 310 usable questionnaires was finally obtained. In this study descriptive and inferential statistics were applied. Descriptive statistics were captured to highlight the owners and managers’ general characteristics and to consolidate their measurement scores. Utilising inferential statistics, the study undertook an investigation into relationships between demographic variables and business characteristics. Furthermore, an investigation of the relationships amongst the following factors: skills development; reasons for starting a business; business challenges; strategic and management knowledge; business leadership; business resources, business environment; business communication; business organisational leadership; organisational strategy and organisational information factors was undertaken. Data were subjected to exploratory factor analysis and both the validity and reliability of the research instrument was assessed. The research findings support an overall significant correlation between management capacity and skills development; reasons for starting a business; business challenges; strategic and management knowledge; business leadership; business resources, business environment; business communication; business organisational leadership; organisational strategy and organisational information. The study also explored the relationship between demographics and business characteristics. A significant relationship was found between business characteristics and variables in the demographic profile, namely the gender of owners/managers, educational levels, qualifications, and gross annual turnover. What follows is a summation of the most significant contributions of this research. The overview of the significance of the tourism sector in the economy and the role of small businesses in the tourism and hospitality industry of the Eastern Cape will benefit researchers and potential owners/managers who have an interest in this developing sector. The study enhances the understanding of the factors that relate to management capacity. The study has established a profile of SMTE sector in the Eastern Cape, South Africa, which can play a significant role for future research. This research makes a contribution to the largely under-researched area of management capacity in small to medium tourism enterprises. Recommendations for owners/managers and consideration of future research included the following. Owners/managers need to have management skills and a strong strategic focus. Through management capacity the needs of the business will be addressed, and capacity building programmes can be tailored to maximise the benefits for owners/managers of SMTEs, thereby improving business performance and avoiding high failure rate. Managers need to be effectively trained to deal with business needs. The management of the business plays a pivotal role in the performance of the enterprise. Managers must be skilled with regards to developing strategic plans, marketing plans, and business plans, thus enhancing management capacity. Longitudinal studies can be undertaken to investigating the same factors which could impact on management capacity. It is recommended that this study be replicated across the global spectrum in order to analyse the factors that impact on management capacity of small to medium tourism businesses of other countries.
- Full Text:
- Date Issued: 2019
Mechanisms and modes of β-N-methylamino-lalanine neurotoxicity: the basis for designing therapies
- Authors: Van Onselen, Rianita
- Date: 2019
- Subjects: Cyanobacteria , Amino acids -- Toxicology , Neurotoxic agents
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/32971 , vital:32483
- Description: Since the discovery of the non-canonical amino acid β-N-methylamino-L-alanine (BMAA) and the demonstration of its acute neurotoxicity in chicks and rats, it has been postulated that BMAA might contribute to the development of neurodegenerative diseases worldwide due to its presence in numerous aquatic and terrestrial food webs. This hypothesized link was widely criticized because of the inability to reproduce symptoms in a BMAA-exposed animal model that resembled the symptoms observed in humans, and for the inability to achieve significant levels of toxicity in in vitro models via the postulated mechanisms of toxicity. The most widely described mechanism of BMAA toxicity was excitotoxicity by over-excitation of ionotropic and/or metabotropic glutamate receptors following activation by BMAA. However, the excitotoxic potency of BMAA is much lower than those of other known excitotoxins and it was not known whether BMAA could accumulate in significant concentrations in synapses to cause the said excitotoxicity. Therefore, uptake of BMAA into synaptic vesicles from where it can be released into synapses in high concentrations, was investigated and it was found that, unlike the uptake that was observed for glutamate, BMAA was not taken up into synaptic vesicles. This discovery suggests that BMAA is not released into synapses via synaptic vesicles and that excitotoxicity is an unlikely mechanism of BMAA toxicity in mammalian systems. Misincorporation of BMAA into proteins in the place of L-serine was suggested to be an important mechanism of BMAA toxicity that could lead to protein misfolding and the subsequent protein aggregates that are typically found in the central nervous system (CNS) of neurodegenerative disease patients. However, previous studies in prokaryotes and in a rat pheochromocytoma PC12 cell line showed that misincorporation of BMAA does not occur to any significant extent. However, these studies were criticized for not using human-derived model systems to show that misincorporation does not occur, and it was argued that due to differences in mitochondrial protein synthesis mechanisms, misincorporation of BMAA into human proteins could not be ruled out as a possible mechanism of toxicity. Therefore, misincorporation of BMAA was investigated in a number of human-derived non-neuronal cell lines and directly compared to the misincorporation of other known amino acid analogues. No evidence of misincorporation of BMAA into these cell lines was obtained and therefore it was concluded that misincorporation of BMAA into proteins does not occur in human-derived cell models. Although misincorporation of BMAA into proteins was refuted as a mechanism of toxicity, the strong interactions between BMAA and proteins that require extensive purification procedures to remove the associated BMAA, could not be discounted as a possible contributor to the toxicity of BMAA. Cell-free interactions between BMAA and enzymes, which resulted in reduced activity, were described previously but the nature of these interactions was never determined. Therefore, the direct interactions between BMAA and a range of commercial proteins and melanin (that is known to also have a strong affinity for BMAA) were investigated in an attempt to describe the nature of these interactions. It was discovered that BMAA has a high affinity for hydroxyl groups, and that if these hydroxyl groups in the form of hydroxyl containing amino acid residues occurred in important regulatory or active sites of proteins, BMAA reduced the enzyme activity. Catalase was subsequently selected as an important enzyme required for the maintenance of the delicate reactive oxygen species (ROS) balance in the CNS, to test the effect of BMAA on the activity of the enzyme. BMAA inhibited a human commercial extract of catalase in a cell free system, and this inhibition appeared to be non-competitive in nature. Subsequently, catalase in an extract from a human cell line was also shown to be inhibited by BMAA and it was concluded that this BMAA induced inhibition of catalase could be an important contributor to the toxicity of BMAA in in vivo systems. The affinity of BMAA for hydroxyl groups, especially the reactive L-tyrosine side chain hydroxyl, was recognized as a possible mechanism that can be utilized to protect against the toxicity of BMAA. It was subsequently shown that excess concentrations of L-serine and L-tyrosine could protect against the BMAA-induced enzyme inhibition and improper folding of proteins in a cell-free system. By administering an equimolar concentration of either L-phenylalanine (the soluble precursor of L-tyrosine) or L-serine an hour before administration of BMAA in a rat model, the BMAA-induced neurotoxicity was greatly reduced, especially by treatment with L-phenylalanine, which resulted in a decrease of between 60-70% in the observed neuropathologies. It was recognized that the protection offered by L-phenylalanine was greater than would be expected if protection was by virtue of direct hydroxyl binding alone and it was subsequently hypothesized that the conversion of L-phenylalanine to dopamine could have contributed to the observed protection. Subsequently, the possible protection offered by dopamine, administered as L-DOPA, against BMAA neurotoxicity was investigated in the same neonatal rat model and compared to the protection offered by L-tyrosine. It was discovered that dopamine protected against the BMAAinduced neuronal cell losses in the hippocampus, striatum and spinal cord but it was not as efficient as L-tyrosine in protection against the BMAA-induced proteinopathies, suggesting two distinct mechanisms of BMAA toxicity, one of which is a depletion of dopamine, which had not been previously described. Finally, the nature of the BMAA-induced dopamine depletion was investigated by administering BMAA in combination with other dopaminergic modifiers viz. apomorphine (a D1/D2 receptor agonist), a dopamine transporter inhibitor (GBR12783) and reserpine (a vesicular monoamine transporter -VMAT2- inhibitor) to the neonatal rat model in an attempt to describe how BMAA functions as a dopaminergic toxin. Based on these results it was concluded that BMAA inhibits uptake of dopamine into synaptic vesicles by inhibiting VMAT2-mediated uptake of dopamine, which causes neuronal loss in the hippocampus, striatum and substantia nigra pars compacta, and that the BMAA-induced inhibition of catalase contributes significantly to the toxicity of BMAA by causing an accumulation of hydrogen peroxide in the hippocampus, striatum and spinal cord, which results in extensive neuronal damage in these areas. This work was the first to thoroughly investigate the mechanisms that explain the observed pathologies caused by BMAA in an in vivo model, and was the first to suggest that BMAA can reduce the dopamine in the CNS by inhibiting VMAT2-mediated uptake of dopamine into synaptic vesicles, and increase damage by reactive oxygen species by inhibiting catalase. BMAA is therefore a multimechanistic and multimodal.
- Full Text:
- Date Issued: 2019
- Authors: Van Onselen, Rianita
- Date: 2019
- Subjects: Cyanobacteria , Amino acids -- Toxicology , Neurotoxic agents
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/32971 , vital:32483
- Description: Since the discovery of the non-canonical amino acid β-N-methylamino-L-alanine (BMAA) and the demonstration of its acute neurotoxicity in chicks and rats, it has been postulated that BMAA might contribute to the development of neurodegenerative diseases worldwide due to its presence in numerous aquatic and terrestrial food webs. This hypothesized link was widely criticized because of the inability to reproduce symptoms in a BMAA-exposed animal model that resembled the symptoms observed in humans, and for the inability to achieve significant levels of toxicity in in vitro models via the postulated mechanisms of toxicity. The most widely described mechanism of BMAA toxicity was excitotoxicity by over-excitation of ionotropic and/or metabotropic glutamate receptors following activation by BMAA. However, the excitotoxic potency of BMAA is much lower than those of other known excitotoxins and it was not known whether BMAA could accumulate in significant concentrations in synapses to cause the said excitotoxicity. Therefore, uptake of BMAA into synaptic vesicles from where it can be released into synapses in high concentrations, was investigated and it was found that, unlike the uptake that was observed for glutamate, BMAA was not taken up into synaptic vesicles. This discovery suggests that BMAA is not released into synapses via synaptic vesicles and that excitotoxicity is an unlikely mechanism of BMAA toxicity in mammalian systems. Misincorporation of BMAA into proteins in the place of L-serine was suggested to be an important mechanism of BMAA toxicity that could lead to protein misfolding and the subsequent protein aggregates that are typically found in the central nervous system (CNS) of neurodegenerative disease patients. However, previous studies in prokaryotes and in a rat pheochromocytoma PC12 cell line showed that misincorporation of BMAA does not occur to any significant extent. However, these studies were criticized for not using human-derived model systems to show that misincorporation does not occur, and it was argued that due to differences in mitochondrial protein synthesis mechanisms, misincorporation of BMAA into human proteins could not be ruled out as a possible mechanism of toxicity. Therefore, misincorporation of BMAA was investigated in a number of human-derived non-neuronal cell lines and directly compared to the misincorporation of other known amino acid analogues. No evidence of misincorporation of BMAA into these cell lines was obtained and therefore it was concluded that misincorporation of BMAA into proteins does not occur in human-derived cell models. Although misincorporation of BMAA into proteins was refuted as a mechanism of toxicity, the strong interactions between BMAA and proteins that require extensive purification procedures to remove the associated BMAA, could not be discounted as a possible contributor to the toxicity of BMAA. Cell-free interactions between BMAA and enzymes, which resulted in reduced activity, were described previously but the nature of these interactions was never determined. Therefore, the direct interactions between BMAA and a range of commercial proteins and melanin (that is known to also have a strong affinity for BMAA) were investigated in an attempt to describe the nature of these interactions. It was discovered that BMAA has a high affinity for hydroxyl groups, and that if these hydroxyl groups in the form of hydroxyl containing amino acid residues occurred in important regulatory or active sites of proteins, BMAA reduced the enzyme activity. Catalase was subsequently selected as an important enzyme required for the maintenance of the delicate reactive oxygen species (ROS) balance in the CNS, to test the effect of BMAA on the activity of the enzyme. BMAA inhibited a human commercial extract of catalase in a cell free system, and this inhibition appeared to be non-competitive in nature. Subsequently, catalase in an extract from a human cell line was also shown to be inhibited by BMAA and it was concluded that this BMAA induced inhibition of catalase could be an important contributor to the toxicity of BMAA in in vivo systems. The affinity of BMAA for hydroxyl groups, especially the reactive L-tyrosine side chain hydroxyl, was recognized as a possible mechanism that can be utilized to protect against the toxicity of BMAA. It was subsequently shown that excess concentrations of L-serine and L-tyrosine could protect against the BMAA-induced enzyme inhibition and improper folding of proteins in a cell-free system. By administering an equimolar concentration of either L-phenylalanine (the soluble precursor of L-tyrosine) or L-serine an hour before administration of BMAA in a rat model, the BMAA-induced neurotoxicity was greatly reduced, especially by treatment with L-phenylalanine, which resulted in a decrease of between 60-70% in the observed neuropathologies. It was recognized that the protection offered by L-phenylalanine was greater than would be expected if protection was by virtue of direct hydroxyl binding alone and it was subsequently hypothesized that the conversion of L-phenylalanine to dopamine could have contributed to the observed protection. Subsequently, the possible protection offered by dopamine, administered as L-DOPA, against BMAA neurotoxicity was investigated in the same neonatal rat model and compared to the protection offered by L-tyrosine. It was discovered that dopamine protected against the BMAAinduced neuronal cell losses in the hippocampus, striatum and spinal cord but it was not as efficient as L-tyrosine in protection against the BMAA-induced proteinopathies, suggesting two distinct mechanisms of BMAA toxicity, one of which is a depletion of dopamine, which had not been previously described. Finally, the nature of the BMAA-induced dopamine depletion was investigated by administering BMAA in combination with other dopaminergic modifiers viz. apomorphine (a D1/D2 receptor agonist), a dopamine transporter inhibitor (GBR12783) and reserpine (a vesicular monoamine transporter -VMAT2- inhibitor) to the neonatal rat model in an attempt to describe how BMAA functions as a dopaminergic toxin. Based on these results it was concluded that BMAA inhibits uptake of dopamine into synaptic vesicles by inhibiting VMAT2-mediated uptake of dopamine, which causes neuronal loss in the hippocampus, striatum and substantia nigra pars compacta, and that the BMAA-induced inhibition of catalase contributes significantly to the toxicity of BMAA by causing an accumulation of hydrogen peroxide in the hippocampus, striatum and spinal cord, which results in extensive neuronal damage in these areas. This work was the first to thoroughly investigate the mechanisms that explain the observed pathologies caused by BMAA in an in vivo model, and was the first to suggest that BMAA can reduce the dopamine in the CNS by inhibiting VMAT2-mediated uptake of dopamine into synaptic vesicles, and increase damage by reactive oxygen species by inhibiting catalase. BMAA is therefore a multimechanistic and multimodal.
- Full Text:
- Date Issued: 2019
Medicinal Plants Used to Treat and Manage Respiratory Infections in the Limpopo Province, South Africa: Phytotherapeutic Study of Bapedi Traditional Healers’ Practices
- Authors: Semenya, Sebua Silas
- Date: 2019
- Subjects: Medicinal plants Respiratory infections -- Alternative treatment
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15716 , vital:40512
- Description: There is paucity of data on South African traditional healers’ (THs) phytotherapeutic practices regarding respiratory infections (RIs). Several people in South Africa are contracting RIs due to prevalence of risk factors. This situation is exacerbated by limited modern health care facilities and associated personnel in some provinces in the country. The primary objectives of this study were twofold. First purpose was to execute a comprehensive social and ethnobotanical surveys aimed at (a) establishing the types of RIs treated by THs and diagnosis techniques used, (b) plants used as therapies for RIs and associated indigenous knowledge practices, (c) source/s of plants used as medicines, (d) harvesting practices, current local availability status, conservation status and threats of indigenous plants as well as the level of conservation knowledge possessed by THs. The second objective was to assess the therapeutic value of the four most frequently used plant species by THs by (a) analysing the phytochemical profile of the plant extracts, (b) their antioxidant activities, and (c) their antibacterial activities. Information linked to the social and ethnobotanical surveys was gathered via a semi-structured questionnaires, supplemented by field observations during face-to-face interview with 240 conveniently selected THs practicing in the municipalities of Capricorn, Sekhukhune and Waterberg districts of the Limpopo Province, South Africa. Data were generally analysed using Microsoft Excel and Statistical Package for the Social Sciences (SPSS). In addition to these softwares, ethnobotanical data were analysed via quantitative ethnobotanical indexes namely use mention (UM), fidelity level (FL), use value (UV) and preference ranking (PR). For laboratory experiments, qualitative phytochemical constitutes of the crude extracts were determined using the standard screening methods. The antioxidant activities of acetone, dichlomethane, hexane, methanol and water crude extracts were evaluated using qualitative and quantitative 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assays. Antibacterial activities of these extracts was assessed using microdilution and bioautography assays. Six types of RIs; tuberculosis (84.1%), sore throat (65%), asthma (58.3%), sinusitis (55%), pneumonia (53.3%) and rhinitis (43.7%) were treated by THs practicing as herbalists (58.7%), herbalists and diviners (40.5%), and diviners (0.4%). The identification of these RIs was based on the patients’ presentation of certain clinical symptoms, with THs practicing both herbalism and divination additionally using bone casting. There was a broad overlap between the clinical signs used to diagnose most of the RIs, and the specificity of symptoms followed when ascertaining an individual infection was low. A total of 224 plant species (83% indigenous and 16.9% exotics) belonging to 177 genera and 85 botanical families, mainly the Fabaceae (25 spp.) and Asteraceae (16 spp.) were used by THs as herbal medicines for the aforesaid RIs and perceived related symptoms (RSs). Most of the documented plant species were used for tuberculosis (82.1%) and asthma (46.4%). Roots (64%) and leaves (13%) formed an important mainstay for medicinal recipes preparations. Different routes of administering these recipes were noted, with oral (75.6%) and nasal (18.8%) being the most preferred. The most widely used species by THs to treat and manage all the six RIs with high UM, FL, UV and PR values included Clerodendrum ternatum, Cryptocarya transvaalensis, Enicostema axillare, Lasiosiphon caffer and Stylochaeton natalensis. Overall larger numbers of species used by Bapedi THs including the mentioned ones are recorded for the first time in scientific literature as remedies for RIs and RSs, thus reflecting a need for more similar studies amongst other ethnic groups of South Africa and elsewhere. The phytochemical screening of four most used plants C. ternatum, C. transvaalensis, E. axillare and L. caffer crude extracts revealed the presence of alkaloids, anthraquinones, cardiac glycosides, flavonoids, phlobatannin, saponins, steroids, tannins and terpenes. All plants including those that did not display any antioxidant activities using qualitative DPPH assay displayed a certain level of scavenging activity when quantified, with the mentioned extracts from E. axillare (water and hexane), L. caffer (water and acetone) and C. ternatum (acetone) showing excellent activity almost comparable to a standard antioxidant drug (ascorbic acid). Plant extracts from all used solvents were active against Mycobacterium smegmatis, Klebsiella pneumoniae, Staphylococcus aureus and Pseudomonas aeruginosa with miniumum bactericidal concentration values ranging between 0.019 and 2.5 mg/ml depending on the plant species. Some of plant extracts exhibited minimum inhibitory concentration values ranging between 0.63 to 2.5 mg/ml. This study showed that most of the diagnosis methods used by Bapedi THs and their herbal medicines have the potential to contribute towards the management and treatment of RIs and RSs. iii | Page Future endeavour should be focused on the following: (a) possibility of collaboration between questioned THs and local western health care practitioners in the treatment of these diseases, and (b) isolation, purification and characterization of the biologically active compounds from extract of the above-stated plants, amongst other inquiries.
- Full Text:
- Date Issued: 2019
- Authors: Semenya, Sebua Silas
- Date: 2019
- Subjects: Medicinal plants Respiratory infections -- Alternative treatment
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15716 , vital:40512
- Description: There is paucity of data on South African traditional healers’ (THs) phytotherapeutic practices regarding respiratory infections (RIs). Several people in South Africa are contracting RIs due to prevalence of risk factors. This situation is exacerbated by limited modern health care facilities and associated personnel in some provinces in the country. The primary objectives of this study were twofold. First purpose was to execute a comprehensive social and ethnobotanical surveys aimed at (a) establishing the types of RIs treated by THs and diagnosis techniques used, (b) plants used as therapies for RIs and associated indigenous knowledge practices, (c) source/s of plants used as medicines, (d) harvesting practices, current local availability status, conservation status and threats of indigenous plants as well as the level of conservation knowledge possessed by THs. The second objective was to assess the therapeutic value of the four most frequently used plant species by THs by (a) analysing the phytochemical profile of the plant extracts, (b) their antioxidant activities, and (c) their antibacterial activities. Information linked to the social and ethnobotanical surveys was gathered via a semi-structured questionnaires, supplemented by field observations during face-to-face interview with 240 conveniently selected THs practicing in the municipalities of Capricorn, Sekhukhune and Waterberg districts of the Limpopo Province, South Africa. Data were generally analysed using Microsoft Excel and Statistical Package for the Social Sciences (SPSS). In addition to these softwares, ethnobotanical data were analysed via quantitative ethnobotanical indexes namely use mention (UM), fidelity level (FL), use value (UV) and preference ranking (PR). For laboratory experiments, qualitative phytochemical constitutes of the crude extracts were determined using the standard screening methods. The antioxidant activities of acetone, dichlomethane, hexane, methanol and water crude extracts were evaluated using qualitative and quantitative 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assays. Antibacterial activities of these extracts was assessed using microdilution and bioautography assays. Six types of RIs; tuberculosis (84.1%), sore throat (65%), asthma (58.3%), sinusitis (55%), pneumonia (53.3%) and rhinitis (43.7%) were treated by THs practicing as herbalists (58.7%), herbalists and diviners (40.5%), and diviners (0.4%). The identification of these RIs was based on the patients’ presentation of certain clinical symptoms, with THs practicing both herbalism and divination additionally using bone casting. There was a broad overlap between the clinical signs used to diagnose most of the RIs, and the specificity of symptoms followed when ascertaining an individual infection was low. A total of 224 plant species (83% indigenous and 16.9% exotics) belonging to 177 genera and 85 botanical families, mainly the Fabaceae (25 spp.) and Asteraceae (16 spp.) were used by THs as herbal medicines for the aforesaid RIs and perceived related symptoms (RSs). Most of the documented plant species were used for tuberculosis (82.1%) and asthma (46.4%). Roots (64%) and leaves (13%) formed an important mainstay for medicinal recipes preparations. Different routes of administering these recipes were noted, with oral (75.6%) and nasal (18.8%) being the most preferred. The most widely used species by THs to treat and manage all the six RIs with high UM, FL, UV and PR values included Clerodendrum ternatum, Cryptocarya transvaalensis, Enicostema axillare, Lasiosiphon caffer and Stylochaeton natalensis. Overall larger numbers of species used by Bapedi THs including the mentioned ones are recorded for the first time in scientific literature as remedies for RIs and RSs, thus reflecting a need for more similar studies amongst other ethnic groups of South Africa and elsewhere. The phytochemical screening of four most used plants C. ternatum, C. transvaalensis, E. axillare and L. caffer crude extracts revealed the presence of alkaloids, anthraquinones, cardiac glycosides, flavonoids, phlobatannin, saponins, steroids, tannins and terpenes. All plants including those that did not display any antioxidant activities using qualitative DPPH assay displayed a certain level of scavenging activity when quantified, with the mentioned extracts from E. axillare (water and hexane), L. caffer (water and acetone) and C. ternatum (acetone) showing excellent activity almost comparable to a standard antioxidant drug (ascorbic acid). Plant extracts from all used solvents were active against Mycobacterium smegmatis, Klebsiella pneumoniae, Staphylococcus aureus and Pseudomonas aeruginosa with miniumum bactericidal concentration values ranging between 0.019 and 2.5 mg/ml depending on the plant species. Some of plant extracts exhibited minimum inhibitory concentration values ranging between 0.63 to 2.5 mg/ml. This study showed that most of the diagnosis methods used by Bapedi THs and their herbal medicines have the potential to contribute towards the management and treatment of RIs and RSs. iii | Page Future endeavour should be focused on the following: (a) possibility of collaboration between questioned THs and local western health care practitioners in the treatment of these diseases, and (b) isolation, purification and characterization of the biologically active compounds from extract of the above-stated plants, amongst other inquiries.
- Full Text:
- Date Issued: 2019
Microalgae as indicators of environmental change in the St Lucia estuarine system
- Authors: Nunes, Monique
- Date: 2019
- Subjects: Microalgae -- South Africa -- St Lucia estuarine
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/31165 , vital:31333
- Description: The St Lucia system represents 56% of the estuarine habitat area in South Africa. This dynamic estuarine lake responds to a complex interaction of climatic and anthropogenic drivers. There has been a long history of human interventions and the extended drought (2002-2012) led to major changes. In 1952, the inlet shared between the estuarine system and the Mfolozi River was artificially separated, which significantly reduced freshwater inflow. The systems were separated because of the silt load from the expanding agricultural activities in the Mfolozi River catchment. The drought prompted a critical review of re-establishing the historic connection, and in July 2012, the beach spillway was excavated marking the start of restoring connectivity. Increased rainfall coupled with the partial re-connection with the agriculturally-impacted Mfolozi River shifted the St Lucia estuarine system to a new wet phase. This study investigated the microalgal dynamics of the estuarine system as it transitioned to this new wet phase. Results showed that the phytoplankton and microphytobenthos (MPB) biomass was low (< 5 ug l-1 and < 60 mg m-2 respectively) throughout the system due to nutrient and light availability, water residence time and sediment type. The increased freshwater inflow from the Mfolozi River was limited to the Narrows and available nutrients promoted the growth of cyanobacteria and dinophytes in the water column. Of interest was the presence of the potentially harmful algal species Prorocentrum minimum. A weekly study investigated the relationship between freshwater inflow, phytoplankton succession and the introduction and persistence of harmful microalgal species in the lower reaches. The increased freshwater inflow received from the Mfolozi River has led to a system in a constant state of flux. The changes in salinity, light availability and water residence time, shifted the phytoplankton functional group structure to one where chlorophytes and euglenoids were dominant. The persistence of the nutrient tolerant euglenoids highlighted the influence of the nutrient-enriched freshwater inflow on the phytoplankton functional groups. However, the relative abundance of all functional groups remained low due to the rapid change in environmental conditions. The next step was to test the use of an artificial substrate as a monitoring method to detect nutrient induced change. Findings from the 28-day study showed that epilithic diatom communities growing on glass slides were good indicators of nutrient enrichment. The epilithic algal biomass increased significantly from 1.5 mg m-2 (Day 14) to 6 mg m-2 (Day 21), following peak river inflow. In contrast, the phytoplankton and MPB showed no discernible increase in biomass. Epilithic diatom community diversity, richness and evenness scores declined due to the increasing relative abundance of a single nutrient tolerant species, Cocconeis placentula var. euglypta. The use of diatoms as indicators of change depends on the accuracy of identification to species level. This can be a slow process requiring a high level of taxonomic expertise. Considering that molecular phylogenetic methods are readily used to produce a reliable taxonomic list, the suitability of DNA metabarcoding for diatom monitoring in the St Lucia Estuary was tested. Comparisons between the molecular and morphological method indicated that the diatom taxonomic composition was similar at 9 to 27% for genus level and 2 to 9% at species level. The low taxonomic similarity was related to the large number of unclassified DNA representative sequences included in the molecular inventory due to the incomplete DNA library database. However, the available operational taxonomic units (OTUs) from the molecular method did provide an effective alternative to determine the relevant community diversity estimates required for the application of the South African Estuarine Health Index (EHI). This research has highlighted the dynamic nature of the St Lucia estuarine system and the effectiveness of the microalgal communities to differentiate between the cyclical climatic phases and anthropogenic stressors such as nutrient enrichment.
- Full Text:
- Date Issued: 2019
- Authors: Nunes, Monique
- Date: 2019
- Subjects: Microalgae -- South Africa -- St Lucia estuarine
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/31165 , vital:31333
- Description: The St Lucia system represents 56% of the estuarine habitat area in South Africa. This dynamic estuarine lake responds to a complex interaction of climatic and anthropogenic drivers. There has been a long history of human interventions and the extended drought (2002-2012) led to major changes. In 1952, the inlet shared between the estuarine system and the Mfolozi River was artificially separated, which significantly reduced freshwater inflow. The systems were separated because of the silt load from the expanding agricultural activities in the Mfolozi River catchment. The drought prompted a critical review of re-establishing the historic connection, and in July 2012, the beach spillway was excavated marking the start of restoring connectivity. Increased rainfall coupled with the partial re-connection with the agriculturally-impacted Mfolozi River shifted the St Lucia estuarine system to a new wet phase. This study investigated the microalgal dynamics of the estuarine system as it transitioned to this new wet phase. Results showed that the phytoplankton and microphytobenthos (MPB) biomass was low (< 5 ug l-1 and < 60 mg m-2 respectively) throughout the system due to nutrient and light availability, water residence time and sediment type. The increased freshwater inflow from the Mfolozi River was limited to the Narrows and available nutrients promoted the growth of cyanobacteria and dinophytes in the water column. Of interest was the presence of the potentially harmful algal species Prorocentrum minimum. A weekly study investigated the relationship between freshwater inflow, phytoplankton succession and the introduction and persistence of harmful microalgal species in the lower reaches. The increased freshwater inflow received from the Mfolozi River has led to a system in a constant state of flux. The changes in salinity, light availability and water residence time, shifted the phytoplankton functional group structure to one where chlorophytes and euglenoids were dominant. The persistence of the nutrient tolerant euglenoids highlighted the influence of the nutrient-enriched freshwater inflow on the phytoplankton functional groups. However, the relative abundance of all functional groups remained low due to the rapid change in environmental conditions. The next step was to test the use of an artificial substrate as a monitoring method to detect nutrient induced change. Findings from the 28-day study showed that epilithic diatom communities growing on glass slides were good indicators of nutrient enrichment. The epilithic algal biomass increased significantly from 1.5 mg m-2 (Day 14) to 6 mg m-2 (Day 21), following peak river inflow. In contrast, the phytoplankton and MPB showed no discernible increase in biomass. Epilithic diatom community diversity, richness and evenness scores declined due to the increasing relative abundance of a single nutrient tolerant species, Cocconeis placentula var. euglypta. The use of diatoms as indicators of change depends on the accuracy of identification to species level. This can be a slow process requiring a high level of taxonomic expertise. Considering that molecular phylogenetic methods are readily used to produce a reliable taxonomic list, the suitability of DNA metabarcoding for diatom monitoring in the St Lucia Estuary was tested. Comparisons between the molecular and morphological method indicated that the diatom taxonomic composition was similar at 9 to 27% for genus level and 2 to 9% at species level. The low taxonomic similarity was related to the large number of unclassified DNA representative sequences included in the molecular inventory due to the incomplete DNA library database. However, the available operational taxonomic units (OTUs) from the molecular method did provide an effective alternative to determine the relevant community diversity estimates required for the application of the South African Estuarine Health Index (EHI). This research has highlighted the dynamic nature of the St Lucia estuarine system and the effectiveness of the microalgal communities to differentiate between the cyclical climatic phases and anthropogenic stressors such as nutrient enrichment.
- Full Text:
- Date Issued: 2019
Microstructural evolution of welded creep aged 12% cr martensitic stainless steel
- Authors: Marx, Genevéve
- Date: 2019
- Subjects: Stainless steel -- Welding
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/30766 , vital:31128
- Description: Tempered martensite ferritic (TMF) steels with 9-12% Cr additions are used extensively for high-pressure steam pipes in coal-fired power plants. They operate at temperatures above 500ºC and are consequently susceptible to creep damage. Due to economic reasons, welding must be performed on service exposed materials when a component needs to be replaced. Fusion welding results in the formation of different microstructural regions within the weldment. The primary failure mechanism of TMF steel welded components is Type IV cracking that results from accelerated void formation in the fine-grained heat affected zone (FGHAZ) during creep. Short-term creep-tests performed across weldments made on new and service exposed steels have shown that the weldment consistently fails in the FGHAZ of the service exposed material. This observation has not yet been fully explained since not much is known about the microstructural evolution of creep aged material during welding. Thus, further investigation on the microstructure of welded creep aged material is warranted. The main aim of this thesis was to investigate the microstructural evolution when welding upon creep aged 9-12% Cr martensitic steels using advanced electron microscopy techniques. X20CrMoV12-1 (12% Cr) in the virgin and long-term service-exposed state were investigated. GleebleTM weld simulation of the FGHAZ was performed on the materials. Detailed microstructural investigations were conducted on the parent and simulated FGHAZ materials to analyse the voids, dislocation density, micro-grains, and precipitates (M23C6, MX, Laves, Z-phase) in the materials. Light Microscopy (LM) and Scanning Electron Microscopy (SEM) was used to examine the voids. Twin-jet electropolished specimens were prepared for precipitate, micro-grain and substructure analyses using Transmission Kikuchi Diffraction (TKD) combined with Energy Dispersive Spectrometry (EDS), Concentric Backscatter (CBS) imaging, Energy-Filtered Transmission Electron Microscopy (EFTEM), and Annular Dark-Field Scanning Transmission Electron Microscopy (ADF-STEM) combined with EDS. The precipitates were extracted from the iron matrix using Bulk Replication and further investigated using EFTEM and STEM-EDS.
- Full Text:
- Date Issued: 2019
- Authors: Marx, Genevéve
- Date: 2019
- Subjects: Stainless steel -- Welding
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/30766 , vital:31128
- Description: Tempered martensite ferritic (TMF) steels with 9-12% Cr additions are used extensively for high-pressure steam pipes in coal-fired power plants. They operate at temperatures above 500ºC and are consequently susceptible to creep damage. Due to economic reasons, welding must be performed on service exposed materials when a component needs to be replaced. Fusion welding results in the formation of different microstructural regions within the weldment. The primary failure mechanism of TMF steel welded components is Type IV cracking that results from accelerated void formation in the fine-grained heat affected zone (FGHAZ) during creep. Short-term creep-tests performed across weldments made on new and service exposed steels have shown that the weldment consistently fails in the FGHAZ of the service exposed material. This observation has not yet been fully explained since not much is known about the microstructural evolution of creep aged material during welding. Thus, further investigation on the microstructure of welded creep aged material is warranted. The main aim of this thesis was to investigate the microstructural evolution when welding upon creep aged 9-12% Cr martensitic steels using advanced electron microscopy techniques. X20CrMoV12-1 (12% Cr) in the virgin and long-term service-exposed state were investigated. GleebleTM weld simulation of the FGHAZ was performed on the materials. Detailed microstructural investigations were conducted on the parent and simulated FGHAZ materials to analyse the voids, dislocation density, micro-grains, and precipitates (M23C6, MX, Laves, Z-phase) in the materials. Light Microscopy (LM) and Scanning Electron Microscopy (SEM) was used to examine the voids. Twin-jet electropolished specimens were prepared for precipitate, micro-grain and substructure analyses using Transmission Kikuchi Diffraction (TKD) combined with Energy Dispersive Spectrometry (EDS), Concentric Backscatter (CBS) imaging, Energy-Filtered Transmission Electron Microscopy (EFTEM), and Annular Dark-Field Scanning Transmission Electron Microscopy (ADF-STEM) combined with EDS. The precipitates were extracted from the iron matrix using Bulk Replication and further investigated using EFTEM and STEM-EDS.
- Full Text:
- Date Issued: 2019
Model for the alleviation of poverty in South Africa
- Authors: Visagie, Jana
- Date: 2019
- Subjects: Poverty -- South Africa , Poverty -- Prevention
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/45701 , vital:38956
- Description: The existence of extreme poverty in an affluent world is morally unacceptable and action needs to be taken. The reduction of economic and social inequality within countries and between countries, as well as the honouring of human rights, is of utmost importance, but the eradication of poverty must take priority One of the main problems with poverty is that poverty impedes human flourishing). People are hungry and constantly live in pain and anguish while education is hampered. People do not develop fully on cognitive and physical levels as poverty allows the exploitation of the poor and their bodies. Feelings of shame and worthlessness are established for reasons people cannot control. To contribute to the ongoing attempts to reduce poverty, it is necessary to have an understanding as to why people remain poor in an affluent world and what can be done to address the causes of poverty. Unless a global culture of ethics and value alignment is pursued for the reduction of poverty, there will be devastating effects for the future Underwriting lasting escapes from chronic poverty demands more investment in education, employment and human development potentials and in the related infrastructure that permits people to enhance their living standards while developing their resilience to handle setbacks and the effects of climate change.ffects include, for example, disaster-risk management, global healthcare and social cohesion. These investment efforts 9 have the ability to generate a virtuous cycle of poverty reduction, national economic growth and enlarged individual opportunity This could diminish the inequalities that decelerate human development. The lack of practical and outcome-based poverty reduction models affords this research with a unique opportunity to fulfil the need and to contribute to the body of knowledge regarding the reduction of poverty towards 2030.
- Full Text:
- Date Issued: 2019
- Authors: Visagie, Jana
- Date: 2019
- Subjects: Poverty -- South Africa , Poverty -- Prevention
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/45701 , vital:38956
- Description: The existence of extreme poverty in an affluent world is morally unacceptable and action needs to be taken. The reduction of economic and social inequality within countries and between countries, as well as the honouring of human rights, is of utmost importance, but the eradication of poverty must take priority One of the main problems with poverty is that poverty impedes human flourishing). People are hungry and constantly live in pain and anguish while education is hampered. People do not develop fully on cognitive and physical levels as poverty allows the exploitation of the poor and their bodies. Feelings of shame and worthlessness are established for reasons people cannot control. To contribute to the ongoing attempts to reduce poverty, it is necessary to have an understanding as to why people remain poor in an affluent world and what can be done to address the causes of poverty. Unless a global culture of ethics and value alignment is pursued for the reduction of poverty, there will be devastating effects for the future Underwriting lasting escapes from chronic poverty demands more investment in education, employment and human development potentials and in the related infrastructure that permits people to enhance their living standards while developing their resilience to handle setbacks and the effects of climate change.ffects include, for example, disaster-risk management, global healthcare and social cohesion. These investment efforts 9 have the ability to generate a virtuous cycle of poverty reduction, national economic growth and enlarged individual opportunity This could diminish the inequalities that decelerate human development. The lack of practical and outcome-based poverty reduction models affords this research with a unique opportunity to fulfil the need and to contribute to the body of knowledge regarding the reduction of poverty towards 2030.
- Full Text:
- Date Issued: 2019
Modelling storm-time TEC changes using linear and non-linear techniques
- Authors: Uwamahoro, Jean Claude
- Date: 2019
- Subjects: Magnetic storms , Astronomy -- Computer programs , Imaging systems in astronomy , Ionospheric storms , Electrons -- Measurement , Magnetosphere -- Observations
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/92908 , vital:30762
- Description: Statistical models based on empirical orthogonal functions (EOF) analysis and non-linear regression analysis (NLRA) were developed for the purpose of estimating the ionospheric total electron content (TEC) during geomagnetic storms. The well-known least squares method (LSM) and Metropolis-Hastings algorithm (MHA) were used as optimization techniques to determine the unknown coefficients of the developed analytical expressions. Artificial Neural Networks (ANNs), the International Reference Ionosphere (IRI) model, and the Multi-Instrument Data Analysis System (MIDAS) tomographic inversion algorithm were also applied to storm-time TEC modelling/reconstruction for various latitudes of the African sector and surrounding areas. This work presents some of the first statistical modeling of the mid-latitude and low-latitude ionosphere during geomagnetic storms that includes solar, geomagnetic and neutral wind drivers.Development and validation of the empirical models were based on storm-time TEC data derived from the global positioning system (GPS) measurements over ground receivers within Africa and surrounding areas. The storm criterion applied was Dst 6 −50 nT and/or Kp > 4. The performance evaluation of MIDAS compared with ANNs to reconstruct storm-time TEC over the African low- and mid-latitude regions showed that MIDAS and ANNs provide comparable results. Their respective mean absolute error (MAE) values were 4.81 and 4.18 TECU. The ANN model was, however, found to perform 24.37 % better than MIDAS at estimating storm-time TEC for low latitudes, while MIDAS is 13.44 % more accurate than ANN for the mid-latitudes. When their performances are compared with the IRI model, both MIDAS and ANN model were found to provide more accurate storm-time TEC reconstructions for the African low- and mid-latitude regions. A comparative study of the performances of EOF, NLRA, ANN, and IRI models to estimate TEC during geomagnetic storm conditions over various latitudes showed that the ANN model is about 10 %, 26 %, and 58 % more accurate than EOF, NLRA, and IRI models, respectively, while EOF was found to perform 15 %, and 44 % better than NLRA and IRI, respectively. It was further found that the NLRA model is 25 % more accurate than the IRI model. We have also investigated for the first time, the role of meridional neutral winds (from the Horizontal Wind Model) to storm-time TEC modelling in the low latitude, northern and southern hemisphere mid-latitude regions of the African sector, based on ANN models. Statistics have shown that the inclusion of the meridional wind velocity in TEC modelling during geomagnetic storms leads to percentage improvements of about 5 % for the low latitude, 10 % and 5 % for the northern and southern hemisphere mid-latitude regions, respectively. High-latitude storm-induced winds and the inter-hemispheric blows of the meridional winds from summer to winter hemisphere have been suggested to be associated with these improvements.
- Full Text:
- Date Issued: 2019
- Authors: Uwamahoro, Jean Claude
- Date: 2019
- Subjects: Magnetic storms , Astronomy -- Computer programs , Imaging systems in astronomy , Ionospheric storms , Electrons -- Measurement , Magnetosphere -- Observations
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/92908 , vital:30762
- Description: Statistical models based on empirical orthogonal functions (EOF) analysis and non-linear regression analysis (NLRA) were developed for the purpose of estimating the ionospheric total electron content (TEC) during geomagnetic storms. The well-known least squares method (LSM) and Metropolis-Hastings algorithm (MHA) were used as optimization techniques to determine the unknown coefficients of the developed analytical expressions. Artificial Neural Networks (ANNs), the International Reference Ionosphere (IRI) model, and the Multi-Instrument Data Analysis System (MIDAS) tomographic inversion algorithm were also applied to storm-time TEC modelling/reconstruction for various latitudes of the African sector and surrounding areas. This work presents some of the first statistical modeling of the mid-latitude and low-latitude ionosphere during geomagnetic storms that includes solar, geomagnetic and neutral wind drivers.Development and validation of the empirical models were based on storm-time TEC data derived from the global positioning system (GPS) measurements over ground receivers within Africa and surrounding areas. The storm criterion applied was Dst 6 −50 nT and/or Kp > 4. The performance evaluation of MIDAS compared with ANNs to reconstruct storm-time TEC over the African low- and mid-latitude regions showed that MIDAS and ANNs provide comparable results. Their respective mean absolute error (MAE) values were 4.81 and 4.18 TECU. The ANN model was, however, found to perform 24.37 % better than MIDAS at estimating storm-time TEC for low latitudes, while MIDAS is 13.44 % more accurate than ANN for the mid-latitudes. When their performances are compared with the IRI model, both MIDAS and ANN model were found to provide more accurate storm-time TEC reconstructions for the African low- and mid-latitude regions. A comparative study of the performances of EOF, NLRA, ANN, and IRI models to estimate TEC during geomagnetic storm conditions over various latitudes showed that the ANN model is about 10 %, 26 %, and 58 % more accurate than EOF, NLRA, and IRI models, respectively, while EOF was found to perform 15 %, and 44 % better than NLRA and IRI, respectively. It was further found that the NLRA model is 25 % more accurate than the IRI model. We have also investigated for the first time, the role of meridional neutral winds (from the Horizontal Wind Model) to storm-time TEC modelling in the low latitude, northern and southern hemisphere mid-latitude regions of the African sector, based on ANN models. Statistics have shown that the inclusion of the meridional wind velocity in TEC modelling during geomagnetic storms leads to percentage improvements of about 5 % for the low latitude, 10 % and 5 % for the northern and southern hemisphere mid-latitude regions, respectively. High-latitude storm-induced winds and the inter-hemispheric blows of the meridional winds from summer to winter hemisphere have been suggested to be associated with these improvements.
- Full Text:
- Date Issued: 2019
Muscle nanostructure, fat colour related fatty acids and Check-All-That-Apply visual profiling of South African A2 beef longissimus
- Authors: Soji, Zimkhitha
- Date: 2019
- Subjects: Meat -- Quality
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15264 , vital:40332
- Description: The main objective of this study was to determine the effect of muscle nanostructure on tenderness, fat colour related fatty acids and Check-All-That-Apply visual profiling of South African A2 beef longissimus. Fifty two A-class steers (n=52) of five breeds (Bonsmara (n=19), Beef master (n=7), Hereford (n=9) and Simbra (n=17)) typically processed in different South African feedlots were studied. The animals were humanely slaughtered at an abattoir following the commercial standard procedures. Fat colour measurements (CIE b*) were taken at the P8 site on hot carcasses at the abattoir. Carcass mass (warm and cold) was recorded at the slaughter line before chilling (warm) and after chilling (cold) while pH0 and temperature were measured at 45 minutes post-mortem on the Longissimus thoracis et lumborum (LTL) muscle. Thereafter, a 20 g subsection of the LTL muscle on the left side of each carcass was sampled for muscle nanostructure analysis. At 24 hours post-slaughter, ultimate pH (pH24) was measured, further subsections of the LTL muscle (20 g) were harvested for further muscle nanostructure analysis and 2.5 kg of the LTL muscle was also harvested for analysis of tenderness, fatty acids and sensory evaluation. The muscle nanostructure (myofibril diameter (MYD), myofibril spacing (MYS), muscle fibre diameter (MFD), muscle fibre spacing (MFS) and sarcomere length (SL)) was analysed using the scanning electron microscope (SEM) while tenderness was measured using Warner Bratzler Shear Force after 45mins, 24hrs, 3 and 7 days aging period at -20 ºC refrigerator temperature. Some proximate fractions (total extractable intramuscular fat (Fat %), Fat Free Dry matter (FFDM %) and Moisture content) and fatty acid profile were measured using extracted fat and fatty acid indices (desaturase index, atherogenicity index) were calculated. Lastly a Check-All-That-Apply visual profiling method rated by an 80-member consumer panel was done to assess consumer meat preferences and perceptions of Bonsmara, Hereford and Simbra A2 fresh steaks. At 45mins post-slaughter breed affected (P<0.05) MYD and MYS, while at 24hrs breed affected MFD and MFS only. Early post-mortem pH (pH0) had no effect on the muscle nanostructure and tenderness while ultimate pH (pH24) affected MYD and MYS only. Muscle temperature at 45mins affected (P<0.05) the MYD, MFD and MFS, while 24hrs muscle temperature affected (P<0.05) MYD only. Tenderness was not related to the muscle nanostructure early post-mortem and there was no uniformity on the changes in muscle nanostructure and tenderness from early post-mortem to 24hrs against the multifaceted carcass mass, muscle pH and temperature effects. During ageing, breed affected the MYD and MYS at 45mins, while at 24hrs in addition to the myofibril structure breed also had an effect on muscle fibre bundle characteristics (MFD and MFS). The changes in MYD, MYS and MFS became constant on day 3 while variations in the MFD still progressed. There was no uniformity on the SL pattern during ageing and a very weak linear relationship between tenderness, SL, MFD and MFS was observed. Notably there was also no uniformity on how the muscle texture features; including the surface structure, fibre separation, and the mechanism of muscle contraction and relaxation; changed throughout the ageing period across and within the breeds. Moreover, breed had a significant effect on pentadecyclic acid, total saturated fatty acids (SFA) and docosahexanoic acid. Differences (P<0.05) in SFA, monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), n-6, n-3, fatty acid ratios, and desaturase index were observed among the white, creamy-white and creamy fat colour. The distribution of fatty acid classes was SFA>MUFA>PUFA in descending order of concentrations of mean values (44.19:40.06:15.75, respectively), while the n-6: n-3 ratio was 12:1. In sensory evaluation, consumers indicated how they would prefer to pay premium for meat with guaranteed muscle and fat colour, low fat content, high marbling and tenderness. Consumers observed breed differences (P<0.05) in muscle fibre separation and muscle colour. The overall liking of each attribute was more on moderate bright cherry red lean colour, moderate yellow fat, very abundant marbling and slight separation of muscle fibres. Differences on discrete liking of each attribute among consumers had an effect on the overall liking of each steak with Hereford steaks being more preferred by consumers. It was concluded that meat from beef animals within the same feeding regime has a different fatty acid composition owing to different breed synthetic pathways and feed ingredients and that meat tenderness is not affected by the muscle nanostructure early post-mortem. However, during ageing, meat tenderness is directly linked to breed related myofibril structure changes in particular the myofibril diameter, spacing between myofibrils and their interaction; while the muscle texture features, fibre diameter, spacing between muscle fibres and sarcomere length explain the non-uniformity of beef tenderness. Also the organoleptic and health related quality of meat assumed more importance among consumers in sensory evaluation. Thus meat classification systems should include more credence aspects or indicators that support credence quality of meat
- Full Text:
- Date Issued: 2019
- Authors: Soji, Zimkhitha
- Date: 2019
- Subjects: Meat -- Quality
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15264 , vital:40332
- Description: The main objective of this study was to determine the effect of muscle nanostructure on tenderness, fat colour related fatty acids and Check-All-That-Apply visual profiling of South African A2 beef longissimus. Fifty two A-class steers (n=52) of five breeds (Bonsmara (n=19), Beef master (n=7), Hereford (n=9) and Simbra (n=17)) typically processed in different South African feedlots were studied. The animals were humanely slaughtered at an abattoir following the commercial standard procedures. Fat colour measurements (CIE b*) were taken at the P8 site on hot carcasses at the abattoir. Carcass mass (warm and cold) was recorded at the slaughter line before chilling (warm) and after chilling (cold) while pH0 and temperature were measured at 45 minutes post-mortem on the Longissimus thoracis et lumborum (LTL) muscle. Thereafter, a 20 g subsection of the LTL muscle on the left side of each carcass was sampled for muscle nanostructure analysis. At 24 hours post-slaughter, ultimate pH (pH24) was measured, further subsections of the LTL muscle (20 g) were harvested for further muscle nanostructure analysis and 2.5 kg of the LTL muscle was also harvested for analysis of tenderness, fatty acids and sensory evaluation. The muscle nanostructure (myofibril diameter (MYD), myofibril spacing (MYS), muscle fibre diameter (MFD), muscle fibre spacing (MFS) and sarcomere length (SL)) was analysed using the scanning electron microscope (SEM) while tenderness was measured using Warner Bratzler Shear Force after 45mins, 24hrs, 3 and 7 days aging period at -20 ºC refrigerator temperature. Some proximate fractions (total extractable intramuscular fat (Fat %), Fat Free Dry matter (FFDM %) and Moisture content) and fatty acid profile were measured using extracted fat and fatty acid indices (desaturase index, atherogenicity index) were calculated. Lastly a Check-All-That-Apply visual profiling method rated by an 80-member consumer panel was done to assess consumer meat preferences and perceptions of Bonsmara, Hereford and Simbra A2 fresh steaks. At 45mins post-slaughter breed affected (P<0.05) MYD and MYS, while at 24hrs breed affected MFD and MFS only. Early post-mortem pH (pH0) had no effect on the muscle nanostructure and tenderness while ultimate pH (pH24) affected MYD and MYS only. Muscle temperature at 45mins affected (P<0.05) the MYD, MFD and MFS, while 24hrs muscle temperature affected (P<0.05) MYD only. Tenderness was not related to the muscle nanostructure early post-mortem and there was no uniformity on the changes in muscle nanostructure and tenderness from early post-mortem to 24hrs against the multifaceted carcass mass, muscle pH and temperature effects. During ageing, breed affected the MYD and MYS at 45mins, while at 24hrs in addition to the myofibril structure breed also had an effect on muscle fibre bundle characteristics (MFD and MFS). The changes in MYD, MYS and MFS became constant on day 3 while variations in the MFD still progressed. There was no uniformity on the SL pattern during ageing and a very weak linear relationship between tenderness, SL, MFD and MFS was observed. Notably there was also no uniformity on how the muscle texture features; including the surface structure, fibre separation, and the mechanism of muscle contraction and relaxation; changed throughout the ageing period across and within the breeds. Moreover, breed had a significant effect on pentadecyclic acid, total saturated fatty acids (SFA) and docosahexanoic acid. Differences (P<0.05) in SFA, monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), n-6, n-3, fatty acid ratios, and desaturase index were observed among the white, creamy-white and creamy fat colour. The distribution of fatty acid classes was SFA>MUFA>PUFA in descending order of concentrations of mean values (44.19:40.06:15.75, respectively), while the n-6: n-3 ratio was 12:1. In sensory evaluation, consumers indicated how they would prefer to pay premium for meat with guaranteed muscle and fat colour, low fat content, high marbling and tenderness. Consumers observed breed differences (P<0.05) in muscle fibre separation and muscle colour. The overall liking of each attribute was more on moderate bright cherry red lean colour, moderate yellow fat, very abundant marbling and slight separation of muscle fibres. Differences on discrete liking of each attribute among consumers had an effect on the overall liking of each steak with Hereford steaks being more preferred by consumers. It was concluded that meat from beef animals within the same feeding regime has a different fatty acid composition owing to different breed synthetic pathways and feed ingredients and that meat tenderness is not affected by the muscle nanostructure early post-mortem. However, during ageing, meat tenderness is directly linked to breed related myofibril structure changes in particular the myofibril diameter, spacing between myofibrils and their interaction; while the muscle texture features, fibre diameter, spacing between muscle fibres and sarcomere length explain the non-uniformity of beef tenderness. Also the organoleptic and health related quality of meat assumed more importance among consumers in sensory evaluation. Thus meat classification systems should include more credence aspects or indicators that support credence quality of meat
- Full Text:
- Date Issued: 2019
Nonlinear optical responses of targeted phthalocyanines when conjugated with nanomaterials or fabricated into polymer thin films
- Authors: Nwaji, Njemuwa Njoku
- Date: 2019
- Subjects: Electrochemistry , Phthalocyanines , Nanoparticles , Bioconjugates , Thin films , Polymers , Nonlinear optics , Nonlinear optical spectroscopy , Nanostructured materials , Raman effect
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/71625 , vital:29926
- Description: A number of zinc, gallium and indium metallophthalocyanines (MPcs) with diverse substituents have been synthesized and characterized using various characterization tools such as proton nuclear magnetic resonance (1HNMR), matrix assisted laser desorption time of flight (MALDI-TOF) mass spectrometry, Fourier-transformed infra-red (FT-IR), Ultraviolet-visible (Uv-vis) spectrophotometry, magnetic circular dichroism and CHNS elemental analysis. The time dependent density functional theory was employed to probe the origin of spectroscopic information in these complexes. Complexes with gallium and indium as central metal showed higher triplet quantum yield compared to the zinc derivatives. Some of the MPcs were covalently linked to nanomaterials such as CdTe, CdTeSe, CdTeSe/ZnO, graphene quantum dots (GQDs) as well as metallic gold (AuNPs) and silver (AgNPs) nanoparticles. Others were either surface assembled onto AuNPs and AgNPs or embedded into polystyrene as polymer source. The phthalocyanine-nanomaterial composites (Pc-NMCs) were characterized with FT-IR, UV-visible spectrophotometry, transmission electron microscopy (TEM), dynamic light scattering (DLS), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and X-ray diffractometry (XRD). The thickness of the thin films was determined by utilization of the knife edge attachment of the A Bruker D8 Discover X-ray diffraction. The optical limiting properties (using the open-aperture Z-scan technique) of the MPcs and the Pc-NMCs were investigated. The investigated MPcs complexes generally showed good optical limiting properties. The nonlinear optical response of the MPcs were improved in the presence of nanomaterials such as the semiconductor quantum dots (SQDs), graphene quantum dots (GQDs) as well as metallic AuNPs and AgNPs with MPc-QDs showing the best optical limiting behavior. The optical limiting properties of the MPcs were greatly enhanced in the presence of polymer thin films.
- Full Text:
- Date Issued: 2019
- Authors: Nwaji, Njemuwa Njoku
- Date: 2019
- Subjects: Electrochemistry , Phthalocyanines , Nanoparticles , Bioconjugates , Thin films , Polymers , Nonlinear optics , Nonlinear optical spectroscopy , Nanostructured materials , Raman effect
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/71625 , vital:29926
- Description: A number of zinc, gallium and indium metallophthalocyanines (MPcs) with diverse substituents have been synthesized and characterized using various characterization tools such as proton nuclear magnetic resonance (1HNMR), matrix assisted laser desorption time of flight (MALDI-TOF) mass spectrometry, Fourier-transformed infra-red (FT-IR), Ultraviolet-visible (Uv-vis) spectrophotometry, magnetic circular dichroism and CHNS elemental analysis. The time dependent density functional theory was employed to probe the origin of spectroscopic information in these complexes. Complexes with gallium and indium as central metal showed higher triplet quantum yield compared to the zinc derivatives. Some of the MPcs were covalently linked to nanomaterials such as CdTe, CdTeSe, CdTeSe/ZnO, graphene quantum dots (GQDs) as well as metallic gold (AuNPs) and silver (AgNPs) nanoparticles. Others were either surface assembled onto AuNPs and AgNPs or embedded into polystyrene as polymer source. The phthalocyanine-nanomaterial composites (Pc-NMCs) were characterized with FT-IR, UV-visible spectrophotometry, transmission electron microscopy (TEM), dynamic light scattering (DLS), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and X-ray diffractometry (XRD). The thickness of the thin films was determined by utilization of the knife edge attachment of the A Bruker D8 Discover X-ray diffraction. The optical limiting properties (using the open-aperture Z-scan technique) of the MPcs and the Pc-NMCs were investigated. The investigated MPcs complexes generally showed good optical limiting properties. The nonlinear optical response of the MPcs were improved in the presence of nanomaterials such as the semiconductor quantum dots (SQDs), graphene quantum dots (GQDs) as well as metallic AuNPs and AgNPs with MPc-QDs showing the best optical limiting behavior. The optical limiting properties of the MPcs were greatly enhanced in the presence of polymer thin films.
- Full Text:
- Date Issued: 2019
Nutritional quality of sausage made with edible meat waste and the perception of consumers on offal product in Eastern Cape Province, South Africa
- Authors: Oluwasegun, Babatunde Alao
- Date: 2019
- Subjects: Meat -- Quality
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/19021 , vital:40094
- Description: Meat processing at the abattoir provides meat by product and waste while, the major part of the muscle which constitutes a third is edible. The edible by products (EBP) of meat have a notable position in our day-to-day life and are used in diverse forms. However, the quality of offal meat may differ according to intrinsic and extrinsic attributes that may occasionally be shaped by the attitude of consumers towards the products. Therefore, the first objective of this thesis focused on features that might influence consumer preferences and their perception of offal meat. A total of 202 consumers from three Municipalities in Amathole District were randomly sampled using exponential nondiscriminative snowball sampling. Data were gathered through a structured questionnaire containing open ended and closed ended questions. The study showed that consumers were more influenced by the freshness, price and availability of the product and these factors are used to determine the purchase outlet. Differences were observed in the offal meat consumption between the age groups. Age groups 25-34 (29.7%) and 35-44 (27.4%) showed the highest offal meat consumption, while the decline was observed in age groups of 55-64 (11.9%), 65- 74 (5.9%) and 75-85 (0.01%) respectively. The most preferred purchase point for offal meat in this study was in butcheries. However, it was observed that the factors influencing offal consumption in Amathole District were similar to meat consumption except that, offals were mainly purchased at butcher shops. The second objective in this study was to determine the sensory characteristics and consumer acceptance of sausages with 10% fat, 30% edible meat waste and 50% edible meat waste. Sensory descriptive attributes such as appearance, texture, colour, taste, flavour and overall acceptance of the sausage were evaluated by sensory panel (n = 60). The sensory panel comprised of students from undergraduates, post-graduates, post-doctoral fellows and lecturers at the University of Fort Hare. The findings of the study indicated that 50% replacement of xiii edible meat waste was similar to the commercial 10% fat with regard to several sensory attributes and pooled liking. Therefore, the utilization of the edible meat waste in production of sausages has the potential to increase profitability in meat industry and minimise meat waste in the industry. However, the cooking method that was more acceptable to consumers in this study was using the microwave as compared to oven-grilling. Furthermore, the effects of different cooking methods (microwave and oven-grilling) on proximate and mineral composition of the formulated sausages were determined. However, the cooking process appeared to have a significant effect on most of the minerals in the sausage. The cooking methods had a significant effect at P <0.01 on the nutrients composition of the formulated sausage. It was observed that the nutritional values of the sausage was better preserved after the cooking process due to higher mean values obtained after cooking. The mean values for calcium (173.1, 221.76, 231.29), potassium (444.57, 158.58, 156.67), magnesium (84.43, 257.97, 127.27), zinc (52.94, 35.27, 27.13), copper (8.8, 7.07, 4.44), manganese (8.74, 0.65, 0.08), sodium (589.42, 604.45, 529.79) and iron (63.3, 85.38, 74.81) in cooked. And the mean values for calcium (286.18, 132.18, 114.79), potassium (206.64, 113.83, 207.81), magnesium (189.89, 33.97, 48.11), zinc (61.05, 28.09, 26.44), copper (2.92, 2.73, 3.89), manganese (1.42, 0.11, 0.35), sodium (566.47, 530.79, 527.35) and iron (77.56, 58.68, 45.42) in uncooked sausage varied greatly among the treatments. Although, the disparities in the mineral content may be attributed to the different edible meat waste from different parts of the cattle which are either from feedlot or pastured based. In regard to the results obtained from proximate and mineral composition, microwave cooking method was found to be the best cooking technique for healthy eating. Finally, the effect of frying with two different oils (sunflower oil and olive oil) on the fatty acid composition of sausage made with edible meat waste was examined. The results revealed that beef sausage containing 70% edible meat wastes and 30% beef (T1) had a higher fat content xiv (25.7%±0.83%) than other treatments. On the other hand, beef sausage fortified with 10% fat and 90% beef (T3) had the lowest fat content but highest FFDM (55.85±0.57%) and moisture content (69.15±0.62) than other treatments. Despite the increase in omega-3: omega-6 fatty acid ratio in the sausage treatments after cooking, the mean value of omega-3: omega-6 fatty acid ratio was greater than 1:5 (0.2) which is within the FAO/WHO recommended range. The omega-3: omega-6 association is well-known for its importance in the diet because it is a key factor for balanced eicosanoid production in the living organism. The significant reduction in saturated fatty acids after cooking showed that there could also be a positive influence on the human health if consumed. Therefore, it may be concluded from the findings of the study that sausage made with edible meat waste as fat replacer is safe for human consumption.
- Full Text:
- Date Issued: 2019
- Authors: Oluwasegun, Babatunde Alao
- Date: 2019
- Subjects: Meat -- Quality
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/19021 , vital:40094
- Description: Meat processing at the abattoir provides meat by product and waste while, the major part of the muscle which constitutes a third is edible. The edible by products (EBP) of meat have a notable position in our day-to-day life and are used in diverse forms. However, the quality of offal meat may differ according to intrinsic and extrinsic attributes that may occasionally be shaped by the attitude of consumers towards the products. Therefore, the first objective of this thesis focused on features that might influence consumer preferences and their perception of offal meat. A total of 202 consumers from three Municipalities in Amathole District were randomly sampled using exponential nondiscriminative snowball sampling. Data were gathered through a structured questionnaire containing open ended and closed ended questions. The study showed that consumers were more influenced by the freshness, price and availability of the product and these factors are used to determine the purchase outlet. Differences were observed in the offal meat consumption between the age groups. Age groups 25-34 (29.7%) and 35-44 (27.4%) showed the highest offal meat consumption, while the decline was observed in age groups of 55-64 (11.9%), 65- 74 (5.9%) and 75-85 (0.01%) respectively. The most preferred purchase point for offal meat in this study was in butcheries. However, it was observed that the factors influencing offal consumption in Amathole District were similar to meat consumption except that, offals were mainly purchased at butcher shops. The second objective in this study was to determine the sensory characteristics and consumer acceptance of sausages with 10% fat, 30% edible meat waste and 50% edible meat waste. Sensory descriptive attributes such as appearance, texture, colour, taste, flavour and overall acceptance of the sausage were evaluated by sensory panel (n = 60). The sensory panel comprised of students from undergraduates, post-graduates, post-doctoral fellows and lecturers at the University of Fort Hare. The findings of the study indicated that 50% replacement of xiii edible meat waste was similar to the commercial 10% fat with regard to several sensory attributes and pooled liking. Therefore, the utilization of the edible meat waste in production of sausages has the potential to increase profitability in meat industry and minimise meat waste in the industry. However, the cooking method that was more acceptable to consumers in this study was using the microwave as compared to oven-grilling. Furthermore, the effects of different cooking methods (microwave and oven-grilling) on proximate and mineral composition of the formulated sausages were determined. However, the cooking process appeared to have a significant effect on most of the minerals in the sausage. The cooking methods had a significant effect at P <0.01 on the nutrients composition of the formulated sausage. It was observed that the nutritional values of the sausage was better preserved after the cooking process due to higher mean values obtained after cooking. The mean values for calcium (173.1, 221.76, 231.29), potassium (444.57, 158.58, 156.67), magnesium (84.43, 257.97, 127.27), zinc (52.94, 35.27, 27.13), copper (8.8, 7.07, 4.44), manganese (8.74, 0.65, 0.08), sodium (589.42, 604.45, 529.79) and iron (63.3, 85.38, 74.81) in cooked. And the mean values for calcium (286.18, 132.18, 114.79), potassium (206.64, 113.83, 207.81), magnesium (189.89, 33.97, 48.11), zinc (61.05, 28.09, 26.44), copper (2.92, 2.73, 3.89), manganese (1.42, 0.11, 0.35), sodium (566.47, 530.79, 527.35) and iron (77.56, 58.68, 45.42) in uncooked sausage varied greatly among the treatments. Although, the disparities in the mineral content may be attributed to the different edible meat waste from different parts of the cattle which are either from feedlot or pastured based. In regard to the results obtained from proximate and mineral composition, microwave cooking method was found to be the best cooking technique for healthy eating. Finally, the effect of frying with two different oils (sunflower oil and olive oil) on the fatty acid composition of sausage made with edible meat waste was examined. The results revealed that beef sausage containing 70% edible meat wastes and 30% beef (T1) had a higher fat content xiv (25.7%±0.83%) than other treatments. On the other hand, beef sausage fortified with 10% fat and 90% beef (T3) had the lowest fat content but highest FFDM (55.85±0.57%) and moisture content (69.15±0.62) than other treatments. Despite the increase in omega-3: omega-6 fatty acid ratio in the sausage treatments after cooking, the mean value of omega-3: omega-6 fatty acid ratio was greater than 1:5 (0.2) which is within the FAO/WHO recommended range. The omega-3: omega-6 association is well-known for its importance in the diet because it is a key factor for balanced eicosanoid production in the living organism. The significant reduction in saturated fatty acids after cooking showed that there could also be a positive influence on the human health if consumed. Therefore, it may be concluded from the findings of the study that sausage made with edible meat waste as fat replacer is safe for human consumption.
- Full Text:
- Date Issued: 2019
Observing cosmic reionization with PAPER: polarized foreground simulations and all sky images
- Authors: Nunhokee, Chuneeta Devi
- Date: 2019
- Subjects: Cosmic background radiation , Astronomy -- Observations , Epoch of reionization -- Research , Hydrogen -- Spectra , Radio interferometers
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/68203 , vital:29218
- Description: The Donald C. Backer Precision Array to Probe the Epoch of Reionization (PAPER, Parsons et al., 2010) was built with an aim to detect the redshifted 21 cm Hydrogen line, which is likely the best probe of thermal evolution of the intergalactic medium and reionization of neutral Hydrogen in our Universe. Observations of the 21 cm signal are challenged by bright astrophysical foregrounds and systematics that require precise modeling in order to extract the cosmological signal. In particular, the instrumental leakage of polarized foregrounds may contaminate the 21 cm power spectrum. In this work, we developed a formalism to describe the leakage due to instrumental widefield effects in visibility-based power spectra and used it to predict contaminations in observations. We find the leakage due to a population of point sources to be higher than the diffuse Galactic emission – for which we can predict minimal contaminations at k>0.3 h Mpc -¹ We also analyzed data from the last observing season of PAPER via all-sky imaging with a view to characterize the foregrounds. We generated an all-sky catalogue of 88 sources down to a flux density of 5 Jy. Moreover, we measured both polarized point source and the Galactic diffuse emission, and used these measurements to constrain our model of polarization leakage. We find the leakage due to a population of point sources to be 12% lower than the prediction from our polarized model.
- Full Text:
- Date Issued: 2019
- Authors: Nunhokee, Chuneeta Devi
- Date: 2019
- Subjects: Cosmic background radiation , Astronomy -- Observations , Epoch of reionization -- Research , Hydrogen -- Spectra , Radio interferometers
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/68203 , vital:29218
- Description: The Donald C. Backer Precision Array to Probe the Epoch of Reionization (PAPER, Parsons et al., 2010) was built with an aim to detect the redshifted 21 cm Hydrogen line, which is likely the best probe of thermal evolution of the intergalactic medium and reionization of neutral Hydrogen in our Universe. Observations of the 21 cm signal are challenged by bright astrophysical foregrounds and systematics that require precise modeling in order to extract the cosmological signal. In particular, the instrumental leakage of polarized foregrounds may contaminate the 21 cm power spectrum. In this work, we developed a formalism to describe the leakage due to instrumental widefield effects in visibility-based power spectra and used it to predict contaminations in observations. We find the leakage due to a population of point sources to be higher than the diffuse Galactic emission – for which we can predict minimal contaminations at k>0.3 h Mpc -¹ We also analyzed data from the last observing season of PAPER via all-sky imaging with a view to characterize the foregrounds. We generated an all-sky catalogue of 88 sources down to a flux density of 5 Jy. Moreover, we measured both polarized point source and the Galactic diffuse emission, and used these measurements to constrain our model of polarization leakage. We find the leakage due to a population of point sources to be 12% lower than the prediction from our polarized model.
- Full Text:
- Date Issued: 2019
Occurrence, feeding ecology, and population structure of two dolphin species, Tursiops aduncus and Delphinus delphis, off the Wild Coast of South Africa
- Authors: Caputo, Michelle Anne
- Date: 2019
- Subjects: Delphinus -- South Africa-- Kwazulu-Natal -- Ecology , Tursoops -- South Africa-- Kwazulu-Natal -- Ecology , Delphinus -- South Africa-- Kwazulu-Natal -- Feeding and feeds , Tursoops -- South Africa-- Kwazulu-Natal -- Feeding and feeds , Dolphins -- South Africa-- Kwazulu-Natal , Delphinus -- South Africa-- Kwazulu-Natal -- Behavior , Tursoops -- South Africa-- Kwazulu-Natal -- Behavior , Marine ecology -- South Africa -- Kwazulu-Natal
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115612 , vital:34197
- Description: Dolphins are apex predators and their movements, foraging activities and population dynamics play an important role in shaping their environment. Understanding their occurrence, movement patterns, and trophic ecology is essential to their conservation, especially as they are considered sentinel species. The Wild Coast of South Africa’s Eastern Cape, is characterized by the annual sardine (Sardinops sagax) run, which serves as an important foraging event for apex predators, including Indo-Pacific bottlenose (Tursiops aduncus) and long-beaked common dolphins (Delphinus delphis). Despite the ecological significance of this event, no dedicated surveys for these species have previously been conducted in this area. The main objectives of this research were to: investigate long-term occurrence of dolphins during the sardine run to determine if there have been any changes over the past 19 years, as has been predicted from common dolphin dietary investigations and anecdotal evidence; to determine short-term occurrence and movement patterns of selected inshore delphinids within the area, which is characterized by three marine protected areas (MPAs); and to use stable isotope analyses to determine trophic relationships and population structure of bottlenose and common dolphins within the region. Long-term data consisted of 131 opportunistic aerial surveys conducted between May and July over the period 1996 to 2014. Results from these surveys indicate that common dolphins, typically associated with sardines, decreased significantly in average group size over the study period (p=0.0343). Bottlenose dolphins, demonstrated no such trend (p=0.916). For both species, greater majority (> 70% of total counts) of sightings were made inside the MPAs. Short-term boat-based surveys were conducted three times a year between June 2014 and December 2016, contributing to a total of 47 days of surveys divided into three locations: Amathole, Hluleka, and Pondoland, each containing a MPA. Density and group size data were analyzed for both species and photographic identification analysis was performed for photographs of bottlenose dolphin dorsal fins. Results indicate that animal and sighting density did not differ temporally (bottlenose dolphin: sighting density – p=0.398, individual density –p=0.781; common dolphin: sighting density –p=0.472, individual density – p=0.204). Environmental factors (sea surface temperature, depth, substrate, and distance from shore) appeared to have limited effect on individual and sighting density and group size for both species (p>0.05). Photographic identification of bottlenose dolphins resulted in 2149 individuals, with a 11.8% resighting rate, with the highest resighting rate within the Pondoland MPA (16.1%). The resighting count did not differ temporally between monthly survey based on generalized linear models (p=0.866), but did differ between study areas (p<0.0001). These results provide the first evidence of the occurrence of both species of dolphin off the Wild Coast, as they were sighted in this region in all survey months. There was no trend in density based on temporal or environmental factors, which suggests other factors are influencing their occurrence. Resightings of bottlenose dolphins within the area suggest that there is some degree of residency, though the majority of animals were only sighted on a single occasion and there was no plateau in the discovery curve. A total of 256 biopsy samples (bottlenose dolphins =128; common dolphins=128) were collected during boat-based surveys. Bottlenose dolphin samples were also collected from adjacent areas to the southwest (Algoa Bay, n=22) and northeast (KwaZulu-Natal (KZN), n=20) of the Wild Coast to investigate similarities and differences between these areas. Despite a high degree of niche overlap between the two species (41%), common dolphins fed with a broader niche (standard ellipse area probability 0.89) than bottlenose dolphins in the summer and a narrower niche in the winter (probability 0.94). There was a clear spatial variation in the diet of bottlenose dolphins along the coast, with individuals from Algoa Bay and Amathole demonstrating 0% niche overlap with individuals from KZN, but the mechanism for these differences remains unclear as other species from South African waters demonstrate a strong southwest to northeast gradient in nitrogen for the Eastern Cape coastline. This research provides valuable baseline information regarding dolphins off the Wild Coast of South Africa, which remained largely unknown. My results indicate that bottlenose dolphins may be more resident in the Wild Coast than previous predicted, and confirm that common dolphins are highly mobile in this area.
- Full Text:
- Date Issued: 2019
- Authors: Caputo, Michelle Anne
- Date: 2019
- Subjects: Delphinus -- South Africa-- Kwazulu-Natal -- Ecology , Tursoops -- South Africa-- Kwazulu-Natal -- Ecology , Delphinus -- South Africa-- Kwazulu-Natal -- Feeding and feeds , Tursoops -- South Africa-- Kwazulu-Natal -- Feeding and feeds , Dolphins -- South Africa-- Kwazulu-Natal , Delphinus -- South Africa-- Kwazulu-Natal -- Behavior , Tursoops -- South Africa-- Kwazulu-Natal -- Behavior , Marine ecology -- South Africa -- Kwazulu-Natal
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115612 , vital:34197
- Description: Dolphins are apex predators and their movements, foraging activities and population dynamics play an important role in shaping their environment. Understanding their occurrence, movement patterns, and trophic ecology is essential to their conservation, especially as they are considered sentinel species. The Wild Coast of South Africa’s Eastern Cape, is characterized by the annual sardine (Sardinops sagax) run, which serves as an important foraging event for apex predators, including Indo-Pacific bottlenose (Tursiops aduncus) and long-beaked common dolphins (Delphinus delphis). Despite the ecological significance of this event, no dedicated surveys for these species have previously been conducted in this area. The main objectives of this research were to: investigate long-term occurrence of dolphins during the sardine run to determine if there have been any changes over the past 19 years, as has been predicted from common dolphin dietary investigations and anecdotal evidence; to determine short-term occurrence and movement patterns of selected inshore delphinids within the area, which is characterized by three marine protected areas (MPAs); and to use stable isotope analyses to determine trophic relationships and population structure of bottlenose and common dolphins within the region. Long-term data consisted of 131 opportunistic aerial surveys conducted between May and July over the period 1996 to 2014. Results from these surveys indicate that common dolphins, typically associated with sardines, decreased significantly in average group size over the study period (p=0.0343). Bottlenose dolphins, demonstrated no such trend (p=0.916). For both species, greater majority (> 70% of total counts) of sightings were made inside the MPAs. Short-term boat-based surveys were conducted three times a year between June 2014 and December 2016, contributing to a total of 47 days of surveys divided into three locations: Amathole, Hluleka, and Pondoland, each containing a MPA. Density and group size data were analyzed for both species and photographic identification analysis was performed for photographs of bottlenose dolphin dorsal fins. Results indicate that animal and sighting density did not differ temporally (bottlenose dolphin: sighting density – p=0.398, individual density –p=0.781; common dolphin: sighting density –p=0.472, individual density – p=0.204). Environmental factors (sea surface temperature, depth, substrate, and distance from shore) appeared to have limited effect on individual and sighting density and group size for both species (p>0.05). Photographic identification of bottlenose dolphins resulted in 2149 individuals, with a 11.8% resighting rate, with the highest resighting rate within the Pondoland MPA (16.1%). The resighting count did not differ temporally between monthly survey based on generalized linear models (p=0.866), but did differ between study areas (p<0.0001). These results provide the first evidence of the occurrence of both species of dolphin off the Wild Coast, as they were sighted in this region in all survey months. There was no trend in density based on temporal or environmental factors, which suggests other factors are influencing their occurrence. Resightings of bottlenose dolphins within the area suggest that there is some degree of residency, though the majority of animals were only sighted on a single occasion and there was no plateau in the discovery curve. A total of 256 biopsy samples (bottlenose dolphins =128; common dolphins=128) were collected during boat-based surveys. Bottlenose dolphin samples were also collected from adjacent areas to the southwest (Algoa Bay, n=22) and northeast (KwaZulu-Natal (KZN), n=20) of the Wild Coast to investigate similarities and differences between these areas. Despite a high degree of niche overlap between the two species (41%), common dolphins fed with a broader niche (standard ellipse area probability 0.89) than bottlenose dolphins in the summer and a narrower niche in the winter (probability 0.94). There was a clear spatial variation in the diet of bottlenose dolphins along the coast, with individuals from Algoa Bay and Amathole demonstrating 0% niche overlap with individuals from KZN, but the mechanism for these differences remains unclear as other species from South African waters demonstrate a strong southwest to northeast gradient in nitrogen for the Eastern Cape coastline. This research provides valuable baseline information regarding dolphins off the Wild Coast of South Africa, which remained largely unknown. My results indicate that bottlenose dolphins may be more resident in the Wild Coast than previous predicted, and confirm that common dolphins are highly mobile in this area.
- Full Text:
- Date Issued: 2019
Ontological Model for Xhosa Beadwork in Marginalised Rural Communities: A Case of the Eastern Cape
- Authors: Tinarwo, Loyd
- Date: 2019
- Subjects: Ontology Beadwork
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15749 , vital:40516
- Description: In South Africa, computational ontologies have gained traction and are increasingly viewed as one of the viable solutions to address the problem of fragmented and unstructured nature of indigenous knowledge (IK) particularly in the marginalized rural communities. The continual existence of IK in tacit form has impeded the use of IK as a potential resource that can catalyze socio-economic and cultural development in South Africa. This study was, therefore, designed to address part of this challenge by developing a Xhosa Beadwork Ontology (XBO) with the goal of structuring the domain knowledge into a reusable body of knowledge. Such a reusable body of knowledge promotes efficient sharing of a common understanding of Xhosa Beadwork in a computational form. The XBO is in OWL 2 DL. The development of the XBO was informed by the NeOn methodology and the iterativeincremental ontology development life cycle within the ambit of Action Research (AR). The XBO was developed around personal ornamentation Xhosa Beadwork consisting of Necklace, Headband, Armlet, Waistband, Bracelet, and Anklet. In this study, the XBO was evaluated focused on ascertaining that the created ontology is a comprehensive representation of the Xhosa Beadwork and is of the required standard. In addition, the XBO was documented into a human understandable and readable resource and was published. The outcome of the study has indicated that the XBO is an adequate, shareable and reusable semantic artifact that can indeed support the formalization and preservation of IK in the domain of Xhosa Beadwork
- Full Text:
- Date Issued: 2019
- Authors: Tinarwo, Loyd
- Date: 2019
- Subjects: Ontology Beadwork
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15749 , vital:40516
- Description: In South Africa, computational ontologies have gained traction and are increasingly viewed as one of the viable solutions to address the problem of fragmented and unstructured nature of indigenous knowledge (IK) particularly in the marginalized rural communities. The continual existence of IK in tacit form has impeded the use of IK as a potential resource that can catalyze socio-economic and cultural development in South Africa. This study was, therefore, designed to address part of this challenge by developing a Xhosa Beadwork Ontology (XBO) with the goal of structuring the domain knowledge into a reusable body of knowledge. Such a reusable body of knowledge promotes efficient sharing of a common understanding of Xhosa Beadwork in a computational form. The XBO is in OWL 2 DL. The development of the XBO was informed by the NeOn methodology and the iterativeincremental ontology development life cycle within the ambit of Action Research (AR). The XBO was developed around personal ornamentation Xhosa Beadwork consisting of Necklace, Headband, Armlet, Waistband, Bracelet, and Anklet. In this study, the XBO was evaluated focused on ascertaining that the created ontology is a comprehensive representation of the Xhosa Beadwork and is of the required standard. In addition, the XBO was documented into a human understandable and readable resource and was published. The outcome of the study has indicated that the XBO is an adequate, shareable and reusable semantic artifact that can indeed support the formalization and preservation of IK in the domain of Xhosa Beadwork
- Full Text:
- Date Issued: 2019
Optimising construction project role-player performance
- Authors: Hefer, Andre Le Roux
- Date: 2019
- Subjects: Construction industry -- Management , Project management Performance
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/40316 , vital:36140
- Description: Authors predict major changes in the requirements to manage complex environments in the 21st century. These 21st century challenges, for Project Managers (PM) in the construction industry, are evident through the ongoing perception that the industry performance record is suboptimal. In the pursuit of performance optimisation, management disciplines developed and implemented theories and models not only to achieve what is required, but also to excel and create high-performing teams. In search of project success, researchers have also identified quantifiable variables, models, success factors and other related issues. The PM’s role in the attainment of success has also been widely researched, especially the impact, influence, methods and tools related to the discipline. Nevertheless, the general concern remains, that the performance of the industry is suboptimal. This study therefore aimed to qualitatively evaluate and examine the various factors and influences on performance of a construction project team. This research applies to the motivation and environmental factors influencing project teams in the achievement of optimum performance; and in doing so, to enhance the performance of project-role players; while adding disciplinespecific theory. This study has employed in-depth interview data, which were thematically analysed. The interviews were conducted in a case-study design comprising four projects in South Africa. The study concluded by emphasising the importance of how role-players RELATE to each other, and LOVE project challenges. It further noted that PMs who are MANAGING LEADERS would be most influential in the project environment; while PROCUREMENT greatly influences the project environment. Relational issues are important to role-players; and they act as MOTIVATORS, with certain issues in a project presenting both performance BARRIERS and DRIVER capabilities. Finally, project MOMENTUM changes constantly, with the current momentum direction influencing the future course thereof. In meeting the aims of the research, a Performance Optimisation Framework was developed, noting how the emergent themes co-exist in optimal performance environments. The study also developed the Project Husbandry approach, reflecting on a caring, nurturing, diligent and mature approach when managing role-players. The study recommends that the themes impacting the project-operating environment should be influenced by management and leadership, in order to optimise the performance of all the role-players involved.
- Full Text:
- Date Issued: 2019
- Authors: Hefer, Andre Le Roux
- Date: 2019
- Subjects: Construction industry -- Management , Project management Performance
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/40316 , vital:36140
- Description: Authors predict major changes in the requirements to manage complex environments in the 21st century. These 21st century challenges, for Project Managers (PM) in the construction industry, are evident through the ongoing perception that the industry performance record is suboptimal. In the pursuit of performance optimisation, management disciplines developed and implemented theories and models not only to achieve what is required, but also to excel and create high-performing teams. In search of project success, researchers have also identified quantifiable variables, models, success factors and other related issues. The PM’s role in the attainment of success has also been widely researched, especially the impact, influence, methods and tools related to the discipline. Nevertheless, the general concern remains, that the performance of the industry is suboptimal. This study therefore aimed to qualitatively evaluate and examine the various factors and influences on performance of a construction project team. This research applies to the motivation and environmental factors influencing project teams in the achievement of optimum performance; and in doing so, to enhance the performance of project-role players; while adding disciplinespecific theory. This study has employed in-depth interview data, which were thematically analysed. The interviews were conducted in a case-study design comprising four projects in South Africa. The study concluded by emphasising the importance of how role-players RELATE to each other, and LOVE project challenges. It further noted that PMs who are MANAGING LEADERS would be most influential in the project environment; while PROCUREMENT greatly influences the project environment. Relational issues are important to role-players; and they act as MOTIVATORS, with certain issues in a project presenting both performance BARRIERS and DRIVER capabilities. Finally, project MOMENTUM changes constantly, with the current momentum direction influencing the future course thereof. In meeting the aims of the research, a Performance Optimisation Framework was developed, noting how the emergent themes co-exist in optimal performance environments. The study also developed the Project Husbandry approach, reflecting on a caring, nurturing, diligent and mature approach when managing role-players. The study recommends that the themes impacting the project-operating environment should be influenced by management and leadership, in order to optimise the performance of all the role-players involved.
- Full Text:
- Date Issued: 2019
Oral narratives as intertexts in selected Nigerian films
- Authors: Usman, Joshua
- Date: 2019
- Subjects: Folk literature -- Nigeria , Oral tradition -- Nigeria Motion pictures -- Nigeria
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/43721 , vital:37038
- Description: This research into the interface between orality and Nigerian film builds on previous scholarly works in the field (Ladebo (1992), Onabajo and M’Bayo (2009), Omolola (2013), Ezeigbo (2013), Mgbemere (2015) and Onzuike (2016)). Evident from these studies is the prevalence of recurring patterns of oral narratives in Nigerian film. The aim of this study is to consider the following research questions: Do film producers/directors adopt the use of oral narratives in Nigerian film texts? How do oral narratives translate into films? What is the rate of recurrence of oral narratives in Nigerian films? Do oral narratives aesthetically influence the quality of Nigerian films? For the purpose of this study a selection of nine Nigerian films (three each from the Yoruba, Hausa and Igbo groups). These films are analysed as primary texts to show the occurrence of elements of orature and oral narratives. Underpinning such analysis is the theory of intertextuality as coined by the French linguist Julia Kristeva. Kristeva sees the text as “intertextuality […] within the text of society and history” (Kristeva, 1980: 37). This approach is augmented by the views of Greenblatt on New Historicism, which implies literature should be studied and interpreted within the context of the history of the author and cultural/social context. The nine films under discussion are considered within their cultural/social context.
- Full Text:
- Date Issued: 2019
- Authors: Usman, Joshua
- Date: 2019
- Subjects: Folk literature -- Nigeria , Oral tradition -- Nigeria Motion pictures -- Nigeria
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/43721 , vital:37038
- Description: This research into the interface between orality and Nigerian film builds on previous scholarly works in the field (Ladebo (1992), Onabajo and M’Bayo (2009), Omolola (2013), Ezeigbo (2013), Mgbemere (2015) and Onzuike (2016)). Evident from these studies is the prevalence of recurring patterns of oral narratives in Nigerian film. The aim of this study is to consider the following research questions: Do film producers/directors adopt the use of oral narratives in Nigerian film texts? How do oral narratives translate into films? What is the rate of recurrence of oral narratives in Nigerian films? Do oral narratives aesthetically influence the quality of Nigerian films? For the purpose of this study a selection of nine Nigerian films (three each from the Yoruba, Hausa and Igbo groups). These films are analysed as primary texts to show the occurrence of elements of orature and oral narratives. Underpinning such analysis is the theory of intertextuality as coined by the French linguist Julia Kristeva. Kristeva sees the text as “intertextuality […] within the text of society and history” (Kristeva, 1980: 37). This approach is augmented by the views of Greenblatt on New Historicism, which implies literature should be studied and interpreted within the context of the history of the author and cultural/social context. The nine films under discussion are considered within their cultural/social context.
- Full Text:
- Date Issued: 2019
Patriarchy and the participation of women in Zimbabwean national politics: a study of selected women Politicians in Matabeleland Region
- Authors: Manyevere, Sithabile
- Date: 2019
- Subjects: Women politicians Women -- Political activity -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/17506 , vital:41082
- Description: The research sought to analyse how patriarchal perceptions have affected women in Zimbabwean national politics with specific focus on women politicians in Matabeleland region. The researcher observed that women politicians in this region seem to face multiple oppressions and yet seem to have been excluded in previous studies. The mixed method approach was adopted for the research. Questionnaires were used for the quantitative method, while key informant interviews and focus group discussions were utilised for the qualitative method. Findings from the survey revealed stereotypical perceptions such as that men are better leaders than women, women are not capable of holding decision making positions and the perception that politics is not safe for women. The findings from the key informants indicate that women politicians in Matabeleland face quite a number of challenges emanating from these patriarchal perceptions. The challenges include violence, humiliation and cultural stigmatization. Although women have attempted to resist patriarchy, it seems that the resistance has not been enough to eliminate the patriarchal mentality and the oppressions that accompany it. The research adopts a combination of feminist and intersectionality theory as a framework for analysis of the problem under investigation. The research potentially contributes to academic discourse by advancing literature on the multi-faceted aspects of patriarchy. The study recommends psychological and financial empowerment of women, electoral reforms and criminalization of offenders. The implementation of proper reforms and corrective measures envisage the long-awaited new dawn among women whom since time memorial, have been suppressed by deep-seated societal and patriarchal beliefs.
- Full Text:
- Date Issued: 2019
- Authors: Manyevere, Sithabile
- Date: 2019
- Subjects: Women politicians Women -- Political activity -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/17506 , vital:41082
- Description: The research sought to analyse how patriarchal perceptions have affected women in Zimbabwean national politics with specific focus on women politicians in Matabeleland region. The researcher observed that women politicians in this region seem to face multiple oppressions and yet seem to have been excluded in previous studies. The mixed method approach was adopted for the research. Questionnaires were used for the quantitative method, while key informant interviews and focus group discussions were utilised for the qualitative method. Findings from the survey revealed stereotypical perceptions such as that men are better leaders than women, women are not capable of holding decision making positions and the perception that politics is not safe for women. The findings from the key informants indicate that women politicians in Matabeleland face quite a number of challenges emanating from these patriarchal perceptions. The challenges include violence, humiliation and cultural stigmatization. Although women have attempted to resist patriarchy, it seems that the resistance has not been enough to eliminate the patriarchal mentality and the oppressions that accompany it. The research adopts a combination of feminist and intersectionality theory as a framework for analysis of the problem under investigation. The research potentially contributes to academic discourse by advancing literature on the multi-faceted aspects of patriarchy. The study recommends psychological and financial empowerment of women, electoral reforms and criminalization of offenders. The implementation of proper reforms and corrective measures envisage the long-awaited new dawn among women whom since time memorial, have been suppressed by deep-seated societal and patriarchal beliefs.
- Full Text:
- Date Issued: 2019
Perceptions on the efficacy of equine assisted play therapy™ in addressing low self-esteem of young bullied children
- Authors: Van Loggerenberg, Monique
- Date: 2019
- Subjects: Animals -- Therapeutic use , Play therapy Bullying Self-esteem -- South Africa Educational psychology -- South Africa
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: http://hdl.handle.net/10948/44179 , vital:37126
- Description: During the past decade, a surge of research emerged regarding the human-animal bond and how interactions with animals could be beneficial to both humans and animals on emotional, cognitive and biological levels. However, amongst others, a gap in literature on the experiences and perceptions of participants involved in animal assisted therapy programmes remain. This research focused on a specific population (bully victims presenting with low self-esteem in the middle childhood phase), also reflecting the perceptions of parties not directly involved in therapy, such as parents and teachers. This research adhered to strict ethical standards in accordance to NMU’s Ethical guidelines as well as in accordance to guidelines provided by the International Institute of Animal Assisted Play Therapy™. The welfare of both the horse and humans involved in this study was deemed equally important. Based upon the Gestalt therapy theory, the therapees were given the opportunity to explore alternatives, be creative and reveal specific therapeutic elements needing attention during each session. The focus was on building a therapeutic relationship in which the therapees could trust themselves, the therapist and horse to find the answers they needed and obtain the necessary skills to overcome feelings of helplessness when being bullied. Therapees presenting with low self-esteem results in specific vulnerability as it can be both the cause of being bullied or lead to being bullied. During the Equine Assisted Play Therapy™ (EAPT™) sessions the disempowered victim was allowed the opportunity to succeed in being assertive. Such children in therapy were given the opportunity to take centre-stage without being made fun of, whilst being encouraged to try out new behaviour and experience personal change. This study highlighted the perceptions of parents and teachers and the lived experiences of bully-victims. Exploring the efficacy of a relatively new therapeutic method, EAPT™ in addressing the low self-esteem levels and subsequent behaviour in the children who participated in this form of therapy, showed promising results in increasing self-esteem levels and positive behavioural changes in therapees.
- Full Text:
- Date Issued: 2019
- Authors: Van Loggerenberg, Monique
- Date: 2019
- Subjects: Animals -- Therapeutic use , Play therapy Bullying Self-esteem -- South Africa Educational psychology -- South Africa
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: http://hdl.handle.net/10948/44179 , vital:37126
- Description: During the past decade, a surge of research emerged regarding the human-animal bond and how interactions with animals could be beneficial to both humans and animals on emotional, cognitive and biological levels. However, amongst others, a gap in literature on the experiences and perceptions of participants involved in animal assisted therapy programmes remain. This research focused on a specific population (bully victims presenting with low self-esteem in the middle childhood phase), also reflecting the perceptions of parties not directly involved in therapy, such as parents and teachers. This research adhered to strict ethical standards in accordance to NMU’s Ethical guidelines as well as in accordance to guidelines provided by the International Institute of Animal Assisted Play Therapy™. The welfare of both the horse and humans involved in this study was deemed equally important. Based upon the Gestalt therapy theory, the therapees were given the opportunity to explore alternatives, be creative and reveal specific therapeutic elements needing attention during each session. The focus was on building a therapeutic relationship in which the therapees could trust themselves, the therapist and horse to find the answers they needed and obtain the necessary skills to overcome feelings of helplessness when being bullied. Therapees presenting with low self-esteem results in specific vulnerability as it can be both the cause of being bullied or lead to being bullied. During the Equine Assisted Play Therapy™ (EAPT™) sessions the disempowered victim was allowed the opportunity to succeed in being assertive. Such children in therapy were given the opportunity to take centre-stage without being made fun of, whilst being encouraged to try out new behaviour and experience personal change. This study highlighted the perceptions of parents and teachers and the lived experiences of bully-victims. Exploring the efficacy of a relatively new therapeutic method, EAPT™ in addressing the low self-esteem levels and subsequent behaviour in the children who participated in this form of therapy, showed promising results in increasing self-esteem levels and positive behavioural changes in therapees.
- Full Text:
- Date Issued: 2019
Personality and Psychological Conditions in Relation to Job Engagement among Municipal Workers in the Eastern Cape Province, South Africa
- Authors: Mhlanga, Tatenda Shaleen
- Date: 2019
- Subjects: Job stress -- South Africa -- Eastern Cape Municipal government -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , D.Com (Industrial Psychology)
- Identifier: http://hdl.handle.net/10353/13729 , vital:39702
- Description: The efficiency of the public service delivery depends on the performance of the public employees. Due to high protest in the Eastern Cape due to poor service delivery, it is crucial to understand if the employees are engaged in doing their work. Although researchers have discovered many of the beneficial and positive consequences of job engagement, little is known about the multitude of antecedent factors that lead to employee engagement such as personality. The motivation of this study is to examine the relationship between the big five personality traits (openness to experience, conscientiousness, extraversion, agreeableness and neuroticism) and job engagement (physical, cognitive and emotional engagement) among municipal employees working in the six district municipalities of the Eastern Cape Province of South Africa. The study also looked at psychological conditions (availability, meaningfulness and safety) as a moderating factor between personality and job engagement. This contributes to the theoretical and conceptual knowledge of how job engagement can be enhanced through the hiring employees with certain personality traits and enhancing meaningfulness, safety and availability of psychological resources in the workplace. Survey questionnaires were used to collect data. Inferential analysis from SPSS was carried out to understand the relationship between the study variables. An overall model of the study was also identified through which showed the relationship on the study variables. The study findings show that openness to experience, conscientiousness, extraversion, agreeableness had a positive relationship with job engagement while neuroticism has a negative relationship with job engagement. All psychological conditions had a positive correlation with job engagement and when combined with the big five personality traits they added more variance in job engagement. The results validate aspects of Kahn’s personal engagement model. v The study recommends managers to switch from an intervention-based focus to a selection-based focus as municipalities can maximize their resources by being able to better predict job success early in the selection process as opposed to trying to maximize performance on a continual basis through interventions. In addition, management practitioners should regularly measure and track employee engagement for the effectiveness of strategic efforts to increase employee engagement to be monitored and evaluated
- Full Text:
- Date Issued: 2019
- Authors: Mhlanga, Tatenda Shaleen
- Date: 2019
- Subjects: Job stress -- South Africa -- Eastern Cape Municipal government -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , D.Com (Industrial Psychology)
- Identifier: http://hdl.handle.net/10353/13729 , vital:39702
- Description: The efficiency of the public service delivery depends on the performance of the public employees. Due to high protest in the Eastern Cape due to poor service delivery, it is crucial to understand if the employees are engaged in doing their work. Although researchers have discovered many of the beneficial and positive consequences of job engagement, little is known about the multitude of antecedent factors that lead to employee engagement such as personality. The motivation of this study is to examine the relationship between the big five personality traits (openness to experience, conscientiousness, extraversion, agreeableness and neuroticism) and job engagement (physical, cognitive and emotional engagement) among municipal employees working in the six district municipalities of the Eastern Cape Province of South Africa. The study also looked at psychological conditions (availability, meaningfulness and safety) as a moderating factor between personality and job engagement. This contributes to the theoretical and conceptual knowledge of how job engagement can be enhanced through the hiring employees with certain personality traits and enhancing meaningfulness, safety and availability of psychological resources in the workplace. Survey questionnaires were used to collect data. Inferential analysis from SPSS was carried out to understand the relationship between the study variables. An overall model of the study was also identified through which showed the relationship on the study variables. The study findings show that openness to experience, conscientiousness, extraversion, agreeableness had a positive relationship with job engagement while neuroticism has a negative relationship with job engagement. All psychological conditions had a positive correlation with job engagement and when combined with the big five personality traits they added more variance in job engagement. The results validate aspects of Kahn’s personal engagement model. v The study recommends managers to switch from an intervention-based focus to a selection-based focus as municipalities can maximize their resources by being able to better predict job success early in the selection process as opposed to trying to maximize performance on a continual basis through interventions. In addition, management practitioners should regularly measure and track employee engagement for the effectiveness of strategic efforts to increase employee engagement to be monitored and evaluated
- Full Text:
- Date Issued: 2019
Personality in relation to work-family conflict among employees in a mining company in South Africa
- Authors: Ruzungunde, Vongai Sarah
- Date: 2019
- Subjects: Job stress Role conflict Work and family
- Language: English
- Type: Thesis , Doctoral , PhD (Industrial Psychology)
- Identifier: http://hdl.handle.net/10353/17007 , vital:40809
- Description: The study set out to investigate how the Big Five personality traits related to work family conflict, taking into consideration the different forms of work family conflict within the mining industry. The study made use of the quantitative design, with the sample consisting of 270 respondents from the selected mine in South Africa. Probability sampling was used to select respondents from the whole population. Data was analysed using descriptive statistical analysis. To examine the association between variables, linear regression analysis was used. Confirmatory analysis was used to measure validity for work-family conflict (WFC). To measure the validity for personality; face validity, construct and content validity were used. Reliability was measured using the Cronbach alpha. The results of the study showed a significant negative relationship between the personality traits and WFC except for the agreeableness trait. The results also showed significant negative correlations with the different forms of WFC, except for the agreeableness trait. Further, the results showed that, when combined, personality traits had greater variance on the experiences of WFC than each of them separately. The findings of this study are helpful to the mining industry as they assist in the implementation of procedures and policies that will help to reduce WFC and its consequences in the work environment.
- Full Text:
- Date Issued: 2019
- Authors: Ruzungunde, Vongai Sarah
- Date: 2019
- Subjects: Job stress Role conflict Work and family
- Language: English
- Type: Thesis , Doctoral , PhD (Industrial Psychology)
- Identifier: http://hdl.handle.net/10353/17007 , vital:40809
- Description: The study set out to investigate how the Big Five personality traits related to work family conflict, taking into consideration the different forms of work family conflict within the mining industry. The study made use of the quantitative design, with the sample consisting of 270 respondents from the selected mine in South Africa. Probability sampling was used to select respondents from the whole population. Data was analysed using descriptive statistical analysis. To examine the association between variables, linear regression analysis was used. Confirmatory analysis was used to measure validity for work-family conflict (WFC). To measure the validity for personality; face validity, construct and content validity were used. Reliability was measured using the Cronbach alpha. The results of the study showed a significant negative relationship between the personality traits and WFC except for the agreeableness trait. The results also showed significant negative correlations with the different forms of WFC, except for the agreeableness trait. Further, the results showed that, when combined, personality traits had greater variance on the experiences of WFC than each of them separately. The findings of this study are helpful to the mining industry as they assist in the implementation of procedures and policies that will help to reduce WFC and its consequences in the work environment.
- Full Text:
- Date Issued: 2019
Perspectives of South African women and midwives on clinical practice in public maternity units: facilitating the scaling-up of such clinical practices
- Authors: Wibbelink, Margreet
- Date: 2019
- Subjects: Physician practice patterns , Midwives -- South Africa -- Attitudes Pregnant women -- South Africa -- Attitudes Midwifery -- South Africa
- Language: English
- Type: Thesis , Doctoral , DCur
- Identifier: http://hdl.handle.net/10948/44422 , vital:37168
- Description: Despite a steady drop globally in maternal and newborn deaths since 1990, thousands of women and newborns still die each year during pregnancy and childbirth. South Africa, together with other countries, failed to achieve the Millennium Development Goal of reducing maternal mortality by three quarters by 2015. This is despite the positive efforts made in the country towards achieving these goals. However, much more still needs to be done. For that reason, proper and safe care of labouring women remains the identified major focus to prevent these deaths. The current study was the culmination of an investigation into the problem of poor performance regarding maternal and perinatal outcomes as identified by the researcher. The aim of this research study was to understand the experiences and perceptions of the women and the midwives regarding the clinical practices in public maternity units in South Africa in order to facilitate the scaling-up of the midwifery practice. A mixed-methods (sequential exploratory) design was used to answer the research question and objectives, and the study was conducted in three phases. In Phase One, a qualitative research design was implemented. The population were all the midwives in the Eastern Cape who had been working in public maternity units and women who had delivered in those settings. Non-probability purposive sampling with inclusion criteria assisted in selecting a suitable sample. Data collection was done using semi-structured audio-recorded interviews from eleven public sector midwives and eleven women receiving care from the midwives in the Eastern Cape, a province of South Africa. On data analysis, three themes emerged, namely participants had diverse experiences of the midwifery practice, midwives highlighted the burden with regard to the shortage of skilled midwives, and midwives identified managerial issues that affect their performance. Phase Two of the study comprised the quantitative research. The population was the midwives in South Africa who were working in public maternity units and nonprobability purposive sampling criteria were used to select participants. Data collection was done by means of a survey that used a tool adapted from the Hennessy-Hicks Training Needs Analysis Questionnaire. Questions for the survey tool were based on the results of Phase One. A total number of 314 questionnaires were completed, returned and analysed. Phase Three of the study comprised the integration of the results of the first two phases. The study found that midwives were committed to provide quality care but major factors needed to be addressed to facilitate scaling-up of clinical midwifery practices. The midwifery profession needed to be strengthened and an enabling working environment provided. Based on the results of the study as well as the theoretical, conceptual and contextual framework, two strategies were developed: Strategy 1: Empowering midwives to deliver woman-centred care in public sector maternity units Strategy 2: Creating an enabling work environment in order to deliver womancentred care in public sector maternity units.
- Full Text:
- Date Issued: 2019
- Authors: Wibbelink, Margreet
- Date: 2019
- Subjects: Physician practice patterns , Midwives -- South Africa -- Attitudes Pregnant women -- South Africa -- Attitudes Midwifery -- South Africa
- Language: English
- Type: Thesis , Doctoral , DCur
- Identifier: http://hdl.handle.net/10948/44422 , vital:37168
- Description: Despite a steady drop globally in maternal and newborn deaths since 1990, thousands of women and newborns still die each year during pregnancy and childbirth. South Africa, together with other countries, failed to achieve the Millennium Development Goal of reducing maternal mortality by three quarters by 2015. This is despite the positive efforts made in the country towards achieving these goals. However, much more still needs to be done. For that reason, proper and safe care of labouring women remains the identified major focus to prevent these deaths. The current study was the culmination of an investigation into the problem of poor performance regarding maternal and perinatal outcomes as identified by the researcher. The aim of this research study was to understand the experiences and perceptions of the women and the midwives regarding the clinical practices in public maternity units in South Africa in order to facilitate the scaling-up of the midwifery practice. A mixed-methods (sequential exploratory) design was used to answer the research question and objectives, and the study was conducted in three phases. In Phase One, a qualitative research design was implemented. The population were all the midwives in the Eastern Cape who had been working in public maternity units and women who had delivered in those settings. Non-probability purposive sampling with inclusion criteria assisted in selecting a suitable sample. Data collection was done using semi-structured audio-recorded interviews from eleven public sector midwives and eleven women receiving care from the midwives in the Eastern Cape, a province of South Africa. On data analysis, three themes emerged, namely participants had diverse experiences of the midwifery practice, midwives highlighted the burden with regard to the shortage of skilled midwives, and midwives identified managerial issues that affect their performance. Phase Two of the study comprised the quantitative research. The population was the midwives in South Africa who were working in public maternity units and nonprobability purposive sampling criteria were used to select participants. Data collection was done by means of a survey that used a tool adapted from the Hennessy-Hicks Training Needs Analysis Questionnaire. Questions for the survey tool were based on the results of Phase One. A total number of 314 questionnaires were completed, returned and analysed. Phase Three of the study comprised the integration of the results of the first two phases. The study found that midwives were committed to provide quality care but major factors needed to be addressed to facilitate scaling-up of clinical midwifery practices. The midwifery profession needed to be strengthened and an enabling working environment provided. Based on the results of the study as well as the theoretical, conceptual and contextual framework, two strategies were developed: Strategy 1: Empowering midwives to deliver woman-centred care in public sector maternity units Strategy 2: Creating an enabling work environment in order to deliver womancentred care in public sector maternity units.
- Full Text:
- Date Issued: 2019