Competing policy imperatives in Post-Apartheid South Africa: An analysis of the effects and larger significance of ESKOM restructuring on the South African automotive industry, 2005-2014
- Authors: Sibuyi, Lucas Nkosana
- Date: 2021-10-29
- Subjects: Eskom (Firm) , South Africa Colonial influence , Electric power Conservation South Africa , Electric utilities Government ownership South Africa , Electric utilities Privatization South Africa , Import substitution South Africa , Government business enterprises South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192911 , vital:45278 , 10.21504/10962/192911
- Description: The state has played an indispensable, major role in the industrialisation of South Africa, and its transformation from an economy of agriculture and mining to one based on manufacturing and services by the 1970s. Large state-owned corporations in communications and transportation, finance, industry and power have been key to this process, which also involved an extensive (and racist form of) import substitution industrialisation (ISI) from the 1920s. The 1970s saw a shift towards neoliberal policies, first under the National-Party-led apartheid government and then under the African-National-Congress-led democratic government formed in 1994. Since the 1980s, this restructuring has profoundly affected state-owned enterprises (SOEs), including the monopoly electricity utility ESKOM, and manufacturing industries, such as the automotive sector. This thesis examines the evolution of and interaction between different areas of neoliberal policy, and their evolution over time through a consideration of the relationship between the restructuring of SOEs and manufacturing, with a focus on ESKOM and autotomotives respectively. Relying on interviews with senior officials, policymakers, union leaders and industrialists, as well as primary documents, the study examines the responses of OEMs in South Africa (BMW, Ford, General Motors, Mercedes Benz/Daimler, Nissan, Toyota and Volkswagen) to ESKOM’s actions, and analyses the root of these actions. It argues that while restructuring has been framed by a common framework, policy development and implementation is not coordinated or cohesive. ESKOM, for example, gutted investment in electricity and maintenance generation capacity to become profitable and create space for Independent Power Providers (IPPs) – neoliberal measures for which it was rewarded and lauded. This took place at a time when national policy emphasised the need to grow manufacturing and attract direct investment by creating an investor-friendly climate resting on infrastructure. It also took place when the Department of Trade and Industry (DTI) rolled out highly successful plans – also praised and rewarded – to help adjust automotives to open markets; the sector grew much larger than under ISI, while other sectors like textiles collapsed. ESKOM’s measures, however, led to a rapid decline in the capacity and stability of the power system, and directly contradicted the drive to expand and globalise manufacturing, in which automotives was now the leading edge. Corruption in the utility worsened, much of it through subcontracting measures rooted in neoliberal reforms, but this did not cause the basic problems. It is argued that this situation of competing policy imperatives reflects deeper, long-term problems in the South African state, including contradictory policies, uneven capacity and a lack of coordination. For example, there was no coordination between the DTI and stakeholder departments that regulate ESKOM, being the shareholder ministry, the Department of Public Enterprises (DPE) and its policy ministry, and the Department of Mineral Resources and Energy (DMRE). These types of problems did not start postapartheid, and post-1994 reforms have not adequately addressed them. What exists is not a “developmental” state, as policymakers hope, but a fractured state of an intermediate type that combines “developmental” and “predatory” features in a oneparty dominant system in which lines between ruling party and state blur, and state resources are leveraged for elite class formation. Such was the case under apartheid skippered by the NP, with Afrikanerisation, and it continues today post-apartheid under the ANC with BEE. Major reforms are needed, but not just in SOE governance or budgets, as many have suggested. If we are to take the nation forward, the basic design of the state must be reformed. The state needs professionalised, coherent policy-making and implementation, proper coordination of state entities and hard decisions. It should manage high levels of public infrastructure, guarantee political stability and credit ratings, and provide policy certainty and predictability. Without big reforms it will remain a chronic underperformer. , Thesis (PhD) -- Faculty of Humanities, Sociology, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Sibuyi, Lucas Nkosana
- Date: 2021-10-29
- Subjects: Eskom (Firm) , South Africa Colonial influence , Electric power Conservation South Africa , Electric utilities Government ownership South Africa , Electric utilities Privatization South Africa , Import substitution South Africa , Government business enterprises South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192911 , vital:45278 , 10.21504/10962/192911
- Description: The state has played an indispensable, major role in the industrialisation of South Africa, and its transformation from an economy of agriculture and mining to one based on manufacturing and services by the 1970s. Large state-owned corporations in communications and transportation, finance, industry and power have been key to this process, which also involved an extensive (and racist form of) import substitution industrialisation (ISI) from the 1920s. The 1970s saw a shift towards neoliberal policies, first under the National-Party-led apartheid government and then under the African-National-Congress-led democratic government formed in 1994. Since the 1980s, this restructuring has profoundly affected state-owned enterprises (SOEs), including the monopoly electricity utility ESKOM, and manufacturing industries, such as the automotive sector. This thesis examines the evolution of and interaction between different areas of neoliberal policy, and their evolution over time through a consideration of the relationship between the restructuring of SOEs and manufacturing, with a focus on ESKOM and autotomotives respectively. Relying on interviews with senior officials, policymakers, union leaders and industrialists, as well as primary documents, the study examines the responses of OEMs in South Africa (BMW, Ford, General Motors, Mercedes Benz/Daimler, Nissan, Toyota and Volkswagen) to ESKOM’s actions, and analyses the root of these actions. It argues that while restructuring has been framed by a common framework, policy development and implementation is not coordinated or cohesive. ESKOM, for example, gutted investment in electricity and maintenance generation capacity to become profitable and create space for Independent Power Providers (IPPs) – neoliberal measures for which it was rewarded and lauded. This took place at a time when national policy emphasised the need to grow manufacturing and attract direct investment by creating an investor-friendly climate resting on infrastructure. It also took place when the Department of Trade and Industry (DTI) rolled out highly successful plans – also praised and rewarded – to help adjust automotives to open markets; the sector grew much larger than under ISI, while other sectors like textiles collapsed. ESKOM’s measures, however, led to a rapid decline in the capacity and stability of the power system, and directly contradicted the drive to expand and globalise manufacturing, in which automotives was now the leading edge. Corruption in the utility worsened, much of it through subcontracting measures rooted in neoliberal reforms, but this did not cause the basic problems. It is argued that this situation of competing policy imperatives reflects deeper, long-term problems in the South African state, including contradictory policies, uneven capacity and a lack of coordination. For example, there was no coordination between the DTI and stakeholder departments that regulate ESKOM, being the shareholder ministry, the Department of Public Enterprises (DPE) and its policy ministry, and the Department of Mineral Resources and Energy (DMRE). These types of problems did not start postapartheid, and post-1994 reforms have not adequately addressed them. What exists is not a “developmental” state, as policymakers hope, but a fractured state of an intermediate type that combines “developmental” and “predatory” features in a oneparty dominant system in which lines between ruling party and state blur, and state resources are leveraged for elite class formation. Such was the case under apartheid skippered by the NP, with Afrikanerisation, and it continues today post-apartheid under the ANC with BEE. Major reforms are needed, but not just in SOE governance or budgets, as many have suggested. If we are to take the nation forward, the basic design of the state must be reformed. The state needs professionalised, coherent policy-making and implementation, proper coordination of state entities and hard decisions. It should manage high levels of public infrastructure, guarantee political stability and credit ratings, and provide policy certainty and predictability. Without big reforms it will remain a chronic underperformer. , Thesis (PhD) -- Faculty of Humanities, Sociology, 2021
- Full Text:
- Date Issued: 2021-10-29
On the gravitational dual to strongly coupled fluids
- Authors: Shawa, Mark Musonda Webster
- Date: 2021-10-29
- Subjects: Quantum gravity , String models , Gauge fields (Physics) , Scattering amplitude (Nuclear physics) , Quark-gluon plasma , Anti-de Sitter/Conformal Field Theory (AdS/CFT) , Gauge/gravity duality
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192933 , vital:45280 , 10.21504/10962/192933
- Description: This thesis discusses the prospect of finding the gravitational dual to the strongly coupled conformal fluids, with a special interest in the quark-gluon plasma. Such a task can be achieved by matching certain physical observables of two apparently different theories that are dually related owing to the fact that the same string theory can be viewed in two different ways. This is particularly useful when one of the theories is intractable while its dual is manageable. We begin by postulating a particular type of gravitational theory from which we determine graviton scattering amplitudes in a special regime of high momentum. Using the gauge–gravity duality dictionary, the graviton scattering amplitudes can be mapped to stress-tensor correlation functions in the gauge theory. One of the outcomes of high-energy scattering experiments involving the quark-gluon plasma is stress-tensor correlator data. This thesis provides an algorithm for matching graviton scattering amplitudes with stress-tensor correlator data which, in principle, can be used to identify the gravitational dual to the quark-gluon plasma. , Thesis (PhD) -- Faculty of Science, Physics and Electronics, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Shawa, Mark Musonda Webster
- Date: 2021-10-29
- Subjects: Quantum gravity , String models , Gauge fields (Physics) , Scattering amplitude (Nuclear physics) , Quark-gluon plasma , Anti-de Sitter/Conformal Field Theory (AdS/CFT) , Gauge/gravity duality
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192933 , vital:45280 , 10.21504/10962/192933
- Description: This thesis discusses the prospect of finding the gravitational dual to the strongly coupled conformal fluids, with a special interest in the quark-gluon plasma. Such a task can be achieved by matching certain physical observables of two apparently different theories that are dually related owing to the fact that the same string theory can be viewed in two different ways. This is particularly useful when one of the theories is intractable while its dual is manageable. We begin by postulating a particular type of gravitational theory from which we determine graviton scattering amplitudes in a special regime of high momentum. Using the gauge–gravity duality dictionary, the graviton scattering amplitudes can be mapped to stress-tensor correlation functions in the gauge theory. One of the outcomes of high-energy scattering experiments involving the quark-gluon plasma is stress-tensor correlator data. This thesis provides an algorithm for matching graviton scattering amplitudes with stress-tensor correlator data which, in principle, can be used to identify the gravitational dual to the quark-gluon plasma. , Thesis (PhD) -- Faculty of Science, Physics and Electronics, 2021
- Full Text:
- Date Issued: 2021-10-29
Access to justice for female victims of crime: a study of girls and women with disabilities in Mashonaland Central Province of Zimbabwe
- Authors: Shumba, Nyaradzo Dorcas
- Date: 2021-09
- Subjects: Criminal justice, Administration of -- Zimbabwe , Women -- Crimes against , Victims of crimes
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22176 , vital:51994
- Description: This thesis utilized a thematic content analysis, looked at how significant barriers affect Mashonaland Central girls and women living with disabilities as victims of crime from accessing justice. Zimbabwe is an optimal case to apply this study, due to its contradictory legislation and evidence of high rate of human rights violations. Mashonaland Central Province is an ideal case study due to the extant records that indicate that it has the highest incidences of violence against women. This study is therefore based in a Victimological epoch with the aim to fill the research gap in acknowledging the process of accessing justice as an important step for protecting and promoting human right. By analyzing interviews conducted with 3 different women aged 18-65 and 3 girls living with disability who were under the age of 18, through the theoretical framework of basic human rights theory and victim dynamics, this thesis contributes to the existing body of knowledge, with suggestions of how these barriers which are inclusive of societal and cultural structures tend to affect the respondents’ everyday lives and in a most pertinent manner towards their right to access justice. This thesis is also governed by the perspectives of key actors in the judicial process including but not limited to the Victim Friendly Unit. The theoretical framework is also operationalized into themes and criteria, which are then applied to analyze the conducted interviews. The emerging findings illuminate that there is a discrepancy between government policy surrounding girls and women living with disabilities and the practical experiences of the respondents. The respondents experienced a lack of accessibility to basic rights such as health care, the law, and to sex education – which are all rights ensured by government policy. Identified consequences included: discouragement in seeking justice due to fears of cultural and social stigma, discouragement in reporting crimes, and receiving adequate support, as well as information from secondhand sources. This study therefore concludes lack of access to justice is a violation of security of person, human dignity and rights to health and life to women and girls living with disability. , Thesis (PhD) -- Faculty of Social Sciences and Humanities, 2021
- Full Text:
- Date Issued: 2021-09
- Authors: Shumba, Nyaradzo Dorcas
- Date: 2021-09
- Subjects: Criminal justice, Administration of -- Zimbabwe , Women -- Crimes against , Victims of crimes
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22176 , vital:51994
- Description: This thesis utilized a thematic content analysis, looked at how significant barriers affect Mashonaland Central girls and women living with disabilities as victims of crime from accessing justice. Zimbabwe is an optimal case to apply this study, due to its contradictory legislation and evidence of high rate of human rights violations. Mashonaland Central Province is an ideal case study due to the extant records that indicate that it has the highest incidences of violence against women. This study is therefore based in a Victimological epoch with the aim to fill the research gap in acknowledging the process of accessing justice as an important step for protecting and promoting human right. By analyzing interviews conducted with 3 different women aged 18-65 and 3 girls living with disability who were under the age of 18, through the theoretical framework of basic human rights theory and victim dynamics, this thesis contributes to the existing body of knowledge, with suggestions of how these barriers which are inclusive of societal and cultural structures tend to affect the respondents’ everyday lives and in a most pertinent manner towards their right to access justice. This thesis is also governed by the perspectives of key actors in the judicial process including but not limited to the Victim Friendly Unit. The theoretical framework is also operationalized into themes and criteria, which are then applied to analyze the conducted interviews. The emerging findings illuminate that there is a discrepancy between government policy surrounding girls and women living with disabilities and the practical experiences of the respondents. The respondents experienced a lack of accessibility to basic rights such as health care, the law, and to sex education – which are all rights ensured by government policy. Identified consequences included: discouragement in seeking justice due to fears of cultural and social stigma, discouragement in reporting crimes, and receiving adequate support, as well as information from secondhand sources. This study therefore concludes lack of access to justice is a violation of security of person, human dignity and rights to health and life to women and girls living with disability. , Thesis (PhD) -- Faculty of Social Sciences and Humanities, 2021
- Full Text:
- Date Issued: 2021-09
Compartmentalization of mineral elements, nutritional factors, biological potentials and phytochemical profiles in the fruits of Musa sinensis L.(Banana) and Musa paradisiaca L.(Plantain): A comparison among soft flesh, peel and boiled peel extract
- Oyeyinka, Barnabas Oluwatomide https://orcid.org/0000-0003-1191-9365
- Authors: Oyeyinka, Barnabas Oluwatomide https://orcid.org/0000-0003-1191-9365
- Date: 2021-09
- Subjects: Bananas , Plantain banana
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/23655 , vital:58274
- Description: Fruits are key contributors to human nutrition and health. However, banana and plantain are typical examples of fruits that have nutritionally under-utilized peel by-products. This study was thus carried out to investigate the compartmental distribution (soft flesh, peel, and boiled peel extract) of mineral elements, nutritional factors, biological potentials, and phytochemical profiles in M. sinensis and M. paradisiaca fruits (ripening stage 4-5), with focus on the peels. Proximal and and antinutritive analyses were done with standard methods of the Association of Official Analytical Chemists (AOAC), while mineral element composition in the fruit components was analyzed with the inductively coupled plasma optical emission spectroscopy (ICP-OES). The pharmacological potential of M. sinensis and M. paradisiaca fruit components was investigated spectrophotometrically by evaluating the polyphenolic constituents (total phenol, proanthocyanidin, flavonoid) and in vitro radical scavenging activities of the aqueous, acetone and ethanol extracts, using DPPH, ABTS, and FRAP assay models. The correlational evaluation of the polyphenolics and antioxidant activity in the components of both fruits using Pearson’s correlational coefficient (r). The proximal assays revealed that moisture content, fiber content, and carbohydratecontent were substantially present in the flesh and peel of M. sinensis and M. paradisiaca, while lipid content was low. The antinutritive results revealed safe levels of alkaloid, oxalate, phytate, and saponin factors in the flesh and peel by-products. Mineral analysis results indicated substantial levels of the macroelements K, Mg, Ca, and P in the peels. Other results revealed that acetone extracts had the highest phenolic, proanthocyanidin and flavonoid constituents respectively, across the soft flesh components ofM. sinensis (119.05 ± 5.80 mgGAE/g; 337.48 ± 13.16 mgCE/g; 602.64 ± 3.65 mgQE/g), M. paradisiaca (114.80 ± 1.49 mgGAE/g; 436.09 ± 36.44 mgCE/g; 777.35 ± 150.95mgQE/g) and the peel component of M. paradisiaca (136.87 ± 5.69 mgGAE/g; 530.06 ± 53.51 mgCE/g; 750.87 ± 55.61 mgQE/g), with an exception of the phenolic content of M. sinensis peel, where it was highest in the ethanol extract (157.19 ± 4.76 mgGAE/g). The ABTS (0.03 mg/mL) and DPPH (0.03 mg/mL) activities were at their highest in the boiled peel extracts of M. sinensis and M. paradisiaca, while ferric reducing power was highest in ethanol extracts across M. sinensis soft flesh, peel, and M. paradisiaca flesh. Acetone extract of M. paradisiaca peel had the highest ferric reducing capacity at peak concentration (0.1 mg/mL). Correlational analysis revealed a negative correlation between respective phenolic, proanthocyanidin, and flavonoid content and the IC50DPPH antioxidant capacity in M. sinensis flesh, M. sinensis peel and M. paradisiaca flesh. Conversely, there was positive correlation between IC50 DPPH with proanthocyanidin and flavonoid in M. paradisiaca peel. Negative correlation was detected between the phenolic, proanthocyanidin and flavonoid contents and IC50ABTS in M. sinensis flesh. Positive correlation was observed between respective phenolic, proanthocyanidin and flavonoid contentwith IC50 ABTS in M. sinensis peel, M. paradisiaca flesh and M. paradisiaca peel. There was negative correlation between the respective phenolic, proanthocyanidin and flavonoid contents and IC50 FRAP in the flesh of M. sinensis, while positive correlation was observed in M. sinensis peel. M. paradisiaca flesh on the other hand, showed positive correlation between the IC50 FRAP and the respective phytochemical contents. However, the peel, there was negative correlation. The correlational evaluation in this study revealed general positive and negative correlational patterns, which implies that no polyphenolic constituent contributed exclusively to antioxidant activity, but rather in combination. Ultrastructure and elemental spectra of M. sinensis and M. paradisiaca exocarps were analysed with electron microscopy (SEM)and energy dispersive x-ray (EDX). Microstructures such as interlocked, polyhedral epidermal cells, ellipsoid-shaped stomata, guard cells, intercellular space, anticlinal-patterned walls, and subsidiary cells were observed. The elemental spectra revealed the presence of elements such as potassium, iron, carbon, oxygen, silicon, and gold, with consistently high to relatively high carbon and oxygen peaks in M. sinensis and M. paradisiaca exocarps. The relative similarity observed in the constituents of a number of the elemental spectra in M. sinensis and M. paradisiaca peels, reflects some degree of relatedness. These outcomes indicate that banana and plantain peel and boiled peel extracts are nutritive, medicinal and potential nutraceuticals, with food preservative, shelf-life and quality enhancement potentials. The instrumentation in this study also have potential relevance in industrial food product analysis. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-09
- Authors: Oyeyinka, Barnabas Oluwatomide https://orcid.org/0000-0003-1191-9365
- Date: 2021-09
- Subjects: Bananas , Plantain banana
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/23655 , vital:58274
- Description: Fruits are key contributors to human nutrition and health. However, banana and plantain are typical examples of fruits that have nutritionally under-utilized peel by-products. This study was thus carried out to investigate the compartmental distribution (soft flesh, peel, and boiled peel extract) of mineral elements, nutritional factors, biological potentials, and phytochemical profiles in M. sinensis and M. paradisiaca fruits (ripening stage 4-5), with focus on the peels. Proximal and and antinutritive analyses were done with standard methods of the Association of Official Analytical Chemists (AOAC), while mineral element composition in the fruit components was analyzed with the inductively coupled plasma optical emission spectroscopy (ICP-OES). The pharmacological potential of M. sinensis and M. paradisiaca fruit components was investigated spectrophotometrically by evaluating the polyphenolic constituents (total phenol, proanthocyanidin, flavonoid) and in vitro radical scavenging activities of the aqueous, acetone and ethanol extracts, using DPPH, ABTS, and FRAP assay models. The correlational evaluation of the polyphenolics and antioxidant activity in the components of both fruits using Pearson’s correlational coefficient (r). The proximal assays revealed that moisture content, fiber content, and carbohydratecontent were substantially present in the flesh and peel of M. sinensis and M. paradisiaca, while lipid content was low. The antinutritive results revealed safe levels of alkaloid, oxalate, phytate, and saponin factors in the flesh and peel by-products. Mineral analysis results indicated substantial levels of the macroelements K, Mg, Ca, and P in the peels. Other results revealed that acetone extracts had the highest phenolic, proanthocyanidin and flavonoid constituents respectively, across the soft flesh components ofM. sinensis (119.05 ± 5.80 mgGAE/g; 337.48 ± 13.16 mgCE/g; 602.64 ± 3.65 mgQE/g), M. paradisiaca (114.80 ± 1.49 mgGAE/g; 436.09 ± 36.44 mgCE/g; 777.35 ± 150.95mgQE/g) and the peel component of M. paradisiaca (136.87 ± 5.69 mgGAE/g; 530.06 ± 53.51 mgCE/g; 750.87 ± 55.61 mgQE/g), with an exception of the phenolic content of M. sinensis peel, where it was highest in the ethanol extract (157.19 ± 4.76 mgGAE/g). The ABTS (0.03 mg/mL) and DPPH (0.03 mg/mL) activities were at their highest in the boiled peel extracts of M. sinensis and M. paradisiaca, while ferric reducing power was highest in ethanol extracts across M. sinensis soft flesh, peel, and M. paradisiaca flesh. Acetone extract of M. paradisiaca peel had the highest ferric reducing capacity at peak concentration (0.1 mg/mL). Correlational analysis revealed a negative correlation between respective phenolic, proanthocyanidin, and flavonoid content and the IC50DPPH antioxidant capacity in M. sinensis flesh, M. sinensis peel and M. paradisiaca flesh. Conversely, there was positive correlation between IC50 DPPH with proanthocyanidin and flavonoid in M. paradisiaca peel. Negative correlation was detected between the phenolic, proanthocyanidin and flavonoid contents and IC50ABTS in M. sinensis flesh. Positive correlation was observed between respective phenolic, proanthocyanidin and flavonoid contentwith IC50 ABTS in M. sinensis peel, M. paradisiaca flesh and M. paradisiaca peel. There was negative correlation between the respective phenolic, proanthocyanidin and flavonoid contents and IC50 FRAP in the flesh of M. sinensis, while positive correlation was observed in M. sinensis peel. M. paradisiaca flesh on the other hand, showed positive correlation between the IC50 FRAP and the respective phytochemical contents. However, the peel, there was negative correlation. The correlational evaluation in this study revealed general positive and negative correlational patterns, which implies that no polyphenolic constituent contributed exclusively to antioxidant activity, but rather in combination. Ultrastructure and elemental spectra of M. sinensis and M. paradisiaca exocarps were analysed with electron microscopy (SEM)and energy dispersive x-ray (EDX). Microstructures such as interlocked, polyhedral epidermal cells, ellipsoid-shaped stomata, guard cells, intercellular space, anticlinal-patterned walls, and subsidiary cells were observed. The elemental spectra revealed the presence of elements such as potassium, iron, carbon, oxygen, silicon, and gold, with consistently high to relatively high carbon and oxygen peaks in M. sinensis and M. paradisiaca exocarps. The relative similarity observed in the constituents of a number of the elemental spectra in M. sinensis and M. paradisiaca peels, reflects some degree of relatedness. These outcomes indicate that banana and plantain peel and boiled peel extracts are nutritive, medicinal and potential nutraceuticals, with food preservative, shelf-life and quality enhancement potentials. The instrumentation in this study also have potential relevance in industrial food product analysis. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-09
Conflict-induced displacement: a study of risk and support for the older refugees in South Africa
- Yusuf, Mohammed Sanusi https://orcid.org/0000-0002-6871-0186
- Authors: Yusuf, Mohammed Sanusi https://orcid.org/0000-0002-6871-0186
- Date: 2021-09
- Subjects: Migration, Internal , Displacement (Psychology) , Refugees -- Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22231 , vital:52001
- Description: With the exponential rise in conflict scenarios globally, the number of internally displaced persons (IDPs) and refugees in foreign countries continues to grow. Although there has been several international efforts and conventions aimed at alleviating the global refugee crisis, the international community has not found a sustainable answer to this knotty problem. In Africa, with some of the worst conflict situations, the scourge of social displacement resulting in migrations have caused different levels of risks and vulnerability for the refugees, as well as capacity constraints for the host communities, governments of host countries and non-governmental bodies working with refugees. In South Africa, with one of the highest numbers of refugees in Africa, especially those coming from African countries, contention for socio-economic space and cultural differences occasionally result in violence between refugees and local people. For the older refugees, the level of risk exposure and hardship have generated interests for both scholars and officials. This thesis explores the risks and support systems for older refugees in South Africa, with specific focus on the Eastern Cape province. Various stakeholders (such as government, NGOs, host communities and the older refugees) in refugee management in South Africa have argued differently on ‘how best’ to manage older refugees in the country. Using qualitative data gathered from refugee communities in the Eastern Cape province and documentary analysis, the study found that the experiences of older refugees in the Eastern Cape province are nuanced. The dominant narrative on the experiences of older refugees indicate peaceful coexistence and resilient organic community support systems, with minor conflicts – often associated with contestations for scarce economic opportunities. Although the study focuses on one province of South Africa, this finding challenges the often-overgeneralised perception of South Africa as ‘xenophobic’. It unpacks the hidden resilient social systems and networks of relationships that bind local populations and the refugees, especially the older ones. In the search for national, regional and global answers on the best way to manage refugee crisis, this study provides insights into community-level structures and dynamics that would benefit policymaking at the national and international levels , Thesis (PhD) -- Faculty of Social Sciences and Humanities, 2021
- Full Text:
- Date Issued: 2021-09
- Authors: Yusuf, Mohammed Sanusi https://orcid.org/0000-0002-6871-0186
- Date: 2021-09
- Subjects: Migration, Internal , Displacement (Psychology) , Refugees -- Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22231 , vital:52001
- Description: With the exponential rise in conflict scenarios globally, the number of internally displaced persons (IDPs) and refugees in foreign countries continues to grow. Although there has been several international efforts and conventions aimed at alleviating the global refugee crisis, the international community has not found a sustainable answer to this knotty problem. In Africa, with some of the worst conflict situations, the scourge of social displacement resulting in migrations have caused different levels of risks and vulnerability for the refugees, as well as capacity constraints for the host communities, governments of host countries and non-governmental bodies working with refugees. In South Africa, with one of the highest numbers of refugees in Africa, especially those coming from African countries, contention for socio-economic space and cultural differences occasionally result in violence between refugees and local people. For the older refugees, the level of risk exposure and hardship have generated interests for both scholars and officials. This thesis explores the risks and support systems for older refugees in South Africa, with specific focus on the Eastern Cape province. Various stakeholders (such as government, NGOs, host communities and the older refugees) in refugee management in South Africa have argued differently on ‘how best’ to manage older refugees in the country. Using qualitative data gathered from refugee communities in the Eastern Cape province and documentary analysis, the study found that the experiences of older refugees in the Eastern Cape province are nuanced. The dominant narrative on the experiences of older refugees indicate peaceful coexistence and resilient organic community support systems, with minor conflicts – often associated with contestations for scarce economic opportunities. Although the study focuses on one province of South Africa, this finding challenges the often-overgeneralised perception of South Africa as ‘xenophobic’. It unpacks the hidden resilient social systems and networks of relationships that bind local populations and the refugees, especially the older ones. In the search for national, regional and global answers on the best way to manage refugee crisis, this study provides insights into community-level structures and dynamics that would benefit policymaking at the national and international levels , Thesis (PhD) -- Faculty of Social Sciences and Humanities, 2021
- Full Text:
- Date Issued: 2021-09
Determination of acaricide resistance profiles, and geographic range of boophilid Rhipicephalus tick spp. (Acari: Ixodidae), and sero-status of tick-borne pathogens on communal cattle in the north-eastern regions of the Eastern Cape Province, South Africa
- Yawa, Mandla https://orcid.org/0000-0002-2402-298X
- Authors: Yawa, Mandla https://orcid.org/0000-0002-2402-298X
- Date: 2021-09
- Subjects: Cattle -- Diseases , Ticks as carriers of disease , Ticks
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21590 , vital:49356
- Description: Cattle industry improves livelihoods for many developing farmers in South Africa, however, ticks and tick-borne diseases (TBDs) pose a detriment impact on cattle success; this is due to their resistance to acaricide application. Thus, this study was conducted to determine the extent of acaricide resistance, serostatus of tick-borne pathogens, and geographic range of boophilid ticks in communal grazing cattle in the north-eastern regions of the Eastern Cape Province (ECP), South Africa. A total of 160 structured questionnaires were prepared and randomly administered to cattle farmers to investigate their knowledge, attitudes, and practice on ticks and TBDs affecting cattle, tick control methods used, and their knowledge of acaricide resistance. Engorged visible cattle ticks were collected seasonally from 10 randomly selected cattle from the community cattle herds during dipping days between October 2018 and September 2019, and stored into the labelled test tubes containing 70 percent ethanol. For TBDs determination, a total of 240 cattle from Elundini and Senqu Municipalities were seasonally used to investigate the prevalence of ticks and TBDs, packed cell volume (PCV), and body condition scores (BCS). Shaw Larval Immersion Test (SLIT) method was used to determine the resistance of Rhipicephalus decoloratus larvae to various acaricides such as amidines, organophosphate, and synthetic pyrethroids. This study indicates that approximately 59 percent of the interviewed cattle farmers had no knowledge of the effect of TBDs affecting cattle production, and 78 percent of respondents considered ticks are the major challenge to the success of their cattle farming. Pour-on (61 percent) was the most commonly used acaricidal treatment system with fortnightly (40 percent and 31percent) treatment frequencies during the summer and winter seasons respectively. Synthetic pyrethroids (73 percent) were the most used acaricide compounds to control ticks. Moreover, approximately 85 percent of respondents perceived that they do not practice acaricide rotation, and 88 percent of the respondents had no knowledge of acaricide resistance. Interestingly, the current study record Rhipicephalus microplus for the first time at Elundini, Senqu, and Walter Sisulu. Based on the morphological traits, a total of 6176 ticks belonging to two boophilid tick species of Rhipicephalus were identified: R. decoloratus (98 percent) and R. microplus (2 percent). Rhipicephalus decoloratus was significantly higher (P<0.05) in Elundini during the hot-dry (3.37±0.121) and hot-wet (3.35±0.121) seasons compared to other localit ies. In Senqu, R. microplus had high counts (P<0.05) during the post-rainy season (1.06±0.027) compared to other localities. From this present study, it was observed that Ehrlichia ruminantium was the most prevalent at Elundini (16 percent) and (14 percent) during post-rainy and hot-dry seasons respectively and 15 percent at Senqu during the post-rainy season. Babesia bigemina was more frequent at Elundini (18 percent) and Senqu (16 percent) during the post-rainy season and hot-wet season, respectively. Cattle BCS were significantly negatively correlated with E. ruminantium (P<0.01; r = -0.203), B. bovis (P<0.01; r = -0.125), and A. marginale (P < 0.01; r = -0.122). On the other hand, PCV was significantly negatively correlated with B. bigemina (P<0.01; r =-0.138). E. ruminantium was strongly positively correlated with Amblyomma hebraeum (P<0.05; r = 0.112), while B. bovis (P<0.05; r = 0.134) and B. bigemina (P<0.05; r = 0.188) were strong positively correlated with Rhipicephalus microplus infestation and B. bigemina (P<0.05; r = 0.077) with Rhipicephalus decoloratus. During acaricide resistance testing, Shaw Larvae Immersion Testing (SLIT) was only performed on R. decoloratus larvae as engorged R. microplus ticks could not meet the required sample size for resistance testing. The current study found that the majority of the tick were susceptible at exposure to differe nt acaricide field concentrations of amidines (49 percent at 250ppm), organophosphates (33 percent and 47 percent at 300ppm and 500ppm, respectively), and synthetic pyrethroids (44 percent and 23 percent at 150ppm and 300ppm, respectively). In conclusion, less knowledge of cattle farmers on the threat pose by ticks on their cattle production results in the spatio-temporal spread of boophilid tick from region to region and from season to season thus increases incidence and risk for tick resistance. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-09
- Authors: Yawa, Mandla https://orcid.org/0000-0002-2402-298X
- Date: 2021-09
- Subjects: Cattle -- Diseases , Ticks as carriers of disease , Ticks
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21590 , vital:49356
- Description: Cattle industry improves livelihoods for many developing farmers in South Africa, however, ticks and tick-borne diseases (TBDs) pose a detriment impact on cattle success; this is due to their resistance to acaricide application. Thus, this study was conducted to determine the extent of acaricide resistance, serostatus of tick-borne pathogens, and geographic range of boophilid ticks in communal grazing cattle in the north-eastern regions of the Eastern Cape Province (ECP), South Africa. A total of 160 structured questionnaires were prepared and randomly administered to cattle farmers to investigate their knowledge, attitudes, and practice on ticks and TBDs affecting cattle, tick control methods used, and their knowledge of acaricide resistance. Engorged visible cattle ticks were collected seasonally from 10 randomly selected cattle from the community cattle herds during dipping days between October 2018 and September 2019, and stored into the labelled test tubes containing 70 percent ethanol. For TBDs determination, a total of 240 cattle from Elundini and Senqu Municipalities were seasonally used to investigate the prevalence of ticks and TBDs, packed cell volume (PCV), and body condition scores (BCS). Shaw Larval Immersion Test (SLIT) method was used to determine the resistance of Rhipicephalus decoloratus larvae to various acaricides such as amidines, organophosphate, and synthetic pyrethroids. This study indicates that approximately 59 percent of the interviewed cattle farmers had no knowledge of the effect of TBDs affecting cattle production, and 78 percent of respondents considered ticks are the major challenge to the success of their cattle farming. Pour-on (61 percent) was the most commonly used acaricidal treatment system with fortnightly (40 percent and 31percent) treatment frequencies during the summer and winter seasons respectively. Synthetic pyrethroids (73 percent) were the most used acaricide compounds to control ticks. Moreover, approximately 85 percent of respondents perceived that they do not practice acaricide rotation, and 88 percent of the respondents had no knowledge of acaricide resistance. Interestingly, the current study record Rhipicephalus microplus for the first time at Elundini, Senqu, and Walter Sisulu. Based on the morphological traits, a total of 6176 ticks belonging to two boophilid tick species of Rhipicephalus were identified: R. decoloratus (98 percent) and R. microplus (2 percent). Rhipicephalus decoloratus was significantly higher (P<0.05) in Elundini during the hot-dry (3.37±0.121) and hot-wet (3.35±0.121) seasons compared to other localit ies. In Senqu, R. microplus had high counts (P<0.05) during the post-rainy season (1.06±0.027) compared to other localities. From this present study, it was observed that Ehrlichia ruminantium was the most prevalent at Elundini (16 percent) and (14 percent) during post-rainy and hot-dry seasons respectively and 15 percent at Senqu during the post-rainy season. Babesia bigemina was more frequent at Elundini (18 percent) and Senqu (16 percent) during the post-rainy season and hot-wet season, respectively. Cattle BCS were significantly negatively correlated with E. ruminantium (P<0.01; r = -0.203), B. bovis (P<0.01; r = -0.125), and A. marginale (P < 0.01; r = -0.122). On the other hand, PCV was significantly negatively correlated with B. bigemina (P<0.01; r =-0.138). E. ruminantium was strongly positively correlated with Amblyomma hebraeum (P<0.05; r = 0.112), while B. bovis (P<0.05; r = 0.134) and B. bigemina (P<0.05; r = 0.188) were strong positively correlated with Rhipicephalus microplus infestation and B. bigemina (P<0.05; r = 0.077) with Rhipicephalus decoloratus. During acaricide resistance testing, Shaw Larvae Immersion Testing (SLIT) was only performed on R. decoloratus larvae as engorged R. microplus ticks could not meet the required sample size for resistance testing. The current study found that the majority of the tick were susceptible at exposure to differe nt acaricide field concentrations of amidines (49 percent at 250ppm), organophosphates (33 percent and 47 percent at 300ppm and 500ppm, respectively), and synthetic pyrethroids (44 percent and 23 percent at 150ppm and 300ppm, respectively). In conclusion, less knowledge of cattle farmers on the threat pose by ticks on their cattle production results in the spatio-temporal spread of boophilid tick from region to region and from season to season thus increases incidence and risk for tick resistance. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-09
Effect of environmental responsible behaviour intervention programme on secondary school learners in environmental education knowledge, attitudes and practices in Nigeria
- Authors: Olagbaju, Oluwaseun Olaitan
- Date: 2021-09
- Subjects: Environmental education , Education, Secondary
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/20284 , vital:45647
- Description: The depletion of the environment compelled researchers to investigate Environmental Education issues, the methods of imparting knowledge and the creation of awareness about environmental problems. However, youths have knowledge of environmental concepts but lack the skills, intentions, and action competence to exhibit positive environmentally responsible behaviour. There is, therefore, a need for a change in human behaviour to overcome current environmental problems. This study determines the effect of an environmental responsible behaviour intervention programme on Junior Secondary School learners in environmental education. It also explores the moderating effects of gender and school location. The study adopted a pre-test, post-test, control group and quasi-experimental design. A multi-stage sampling technique was employed. Eight (8) coeducational secondary schools in Ibadan, Nigeria, were selected based on environmental challenges in their immediate environment. There were four (4) schools from Ibadan city (urban area of Ibadan) and four (4) from Ibadan less city (rural area of Ibadan). Seven hypotheses were tested at a 0.05 level of significance. Five research instruments were used for this study. Analysis of Covariance (ANCOVA) was used in testing the seven formulated hypotheses. Estimated Marginal mean analysis was used to determine the source of significant effect of treatment. A significant interaction effect was described using a graphical representation. All hypotheses were tested at P< .05 level of significance. The result reveals that there was a significant main effect of treatment (Environmental responsible behaviour intervention programme on Junior Secondary School learners’ environmental knowledge (F(1,715) = 40.62, p < 0.05, Partial , 2 .054). There was also significant main effect of treatment (environmental responsible behaviour intervention programme on junior secondary school students’ environmental attitude. (F(1,715) = 32.36, p < 0.05. partial 2 = 0.043). The effect of treatment (Environmental responsible behaviour intervention programme) on students’ environmental practices was statistically significant, F(1,715) = 17.02, p < 0.05. partial 2 = 0.023). The findings shows that there was a significant main effect of school location (Urban and Rural) on Junior Secondary School students’ environmental knowledge (F(1,716) = 71.62 p< 0.05. partial 2 =0.091). There was no significant main effect of gender (male / female) F(1,715) =0.27, p> 0.05, partial 2 = 0.000. The findings further shows that there was significant main effect of school location on students’ environmental attitude, (F(1,175) =39.21, p< 0.05 partial 2 = 0.052) Shows that there was no significant main effect of gender on students’ environmental attitude F(1,715) =2.1, p> 0.05. partial 2 =0.003 There was significant main effect of school location on students’ environmental practices, F(1,715) = 17.02, p< 0.05 partial 2 = 0.019 but there was no significant main effect of gender on students’ environmental practices, (F(1,715) = 1.17, p> 0.05. partial 2 = 0.002). Based on these findings, it is recommended that teachers should use an environmental responsible behaviour intervention programme in teaching environmental concepts in the classroom. To support this, group/teamwork should be encouraged amongst students. Students should be allowed to construct knowledge in order to bring about their active participation with a view to making learning realistic and effective and to enable the exhibition of environmentally friendly behaviour. , Thesis (PhD)(Education)-- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-09
- Authors: Olagbaju, Oluwaseun Olaitan
- Date: 2021-09
- Subjects: Environmental education , Education, Secondary
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/20284 , vital:45647
- Description: The depletion of the environment compelled researchers to investigate Environmental Education issues, the methods of imparting knowledge and the creation of awareness about environmental problems. However, youths have knowledge of environmental concepts but lack the skills, intentions, and action competence to exhibit positive environmentally responsible behaviour. There is, therefore, a need for a change in human behaviour to overcome current environmental problems. This study determines the effect of an environmental responsible behaviour intervention programme on Junior Secondary School learners in environmental education. It also explores the moderating effects of gender and school location. The study adopted a pre-test, post-test, control group and quasi-experimental design. A multi-stage sampling technique was employed. Eight (8) coeducational secondary schools in Ibadan, Nigeria, were selected based on environmental challenges in their immediate environment. There were four (4) schools from Ibadan city (urban area of Ibadan) and four (4) from Ibadan less city (rural area of Ibadan). Seven hypotheses were tested at a 0.05 level of significance. Five research instruments were used for this study. Analysis of Covariance (ANCOVA) was used in testing the seven formulated hypotheses. Estimated Marginal mean analysis was used to determine the source of significant effect of treatment. A significant interaction effect was described using a graphical representation. All hypotheses were tested at P< .05 level of significance. The result reveals that there was a significant main effect of treatment (Environmental responsible behaviour intervention programme on Junior Secondary School learners’ environmental knowledge (F(1,715) = 40.62, p < 0.05, Partial , 2 .054). There was also significant main effect of treatment (environmental responsible behaviour intervention programme on junior secondary school students’ environmental attitude. (F(1,715) = 32.36, p < 0.05. partial 2 = 0.043). The effect of treatment (Environmental responsible behaviour intervention programme) on students’ environmental practices was statistically significant, F(1,715) = 17.02, p < 0.05. partial 2 = 0.023). The findings shows that there was a significant main effect of school location (Urban and Rural) on Junior Secondary School students’ environmental knowledge (F(1,716) = 71.62 p< 0.05. partial 2 =0.091). There was no significant main effect of gender (male / female) F(1,715) =0.27, p> 0.05, partial 2 = 0.000. The findings further shows that there was significant main effect of school location on students’ environmental attitude, (F(1,175) =39.21, p< 0.05 partial 2 = 0.052) Shows that there was no significant main effect of gender on students’ environmental attitude F(1,715) =2.1, p> 0.05. partial 2 =0.003 There was significant main effect of school location on students’ environmental practices, F(1,715) = 17.02, p< 0.05 partial 2 = 0.019 but there was no significant main effect of gender on students’ environmental practices, (F(1,715) = 1.17, p> 0.05. partial 2 = 0.002). Based on these findings, it is recommended that teachers should use an environmental responsible behaviour intervention programme in teaching environmental concepts in the classroom. To support this, group/teamwork should be encouraged amongst students. Students should be allowed to construct knowledge in order to bring about their active participation with a view to making learning realistic and effective and to enable the exhibition of environmentally friendly behaviour. , Thesis (PhD)(Education)-- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-09
Evaluation of bacteria laccase hybrid biosensor and application in the detection of phenolic contaminants in water
- Edoamodu, Chiedu Epiphany https://orcid.org/0000-0002-9254-3955
- Authors: Edoamodu, Chiedu Epiphany https://orcid.org/0000-0002-9254-3955
- Date: 2021-09
- Subjects: Laccase , Water -- Purification
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22820 , vital:52802
- Description: The continuous outpour of aromatic pollutants in diverse groups, emanating from the industrial and domestic system due to population density, industrialisation and technological advancement is alarming. The increasing strength in wastewater discharge constitutes the main cause of the natural water pollution load, causing scarcity of potable water for consumption with an increasing health challenge. The physiochemical treatment approach has faced a series of limitations with little or no success. Hindrance to wastewater management can cause a point source contamination problem that might increase treatment cost and release a broad range of chemical contaminants in the environment. Hence, green, eco-friendly and cost-effective tools are imperative. The application of laccase has received much attention in bioremediation and bioprocessing matters owing to the oxidising capacity of a wide range of substrates. The process requires available molecular oxygen for its activation, releasing water as a by-product thus, establishing this research. This study was devised to examine the bioprocessing potentials of hybrid and amalgamated laccases extracted from the diverse environmental milieu of the Eastern Cape Province, South Africa. Bacteria producing laccase were isolated from marine sediment, cow dung, and wastewater samples via selective enrichment with some aromatic compounds. The axenic cultures were screened for laccase activity on various phenolic and non-phenolic substrates. The isolates were identified via molecular techniques and they belonged to the gammaproteobacteria and Bacilli classes under the following genera, Enterobacter and Bacillus. They were deposited in the NCBI database as Enterobacter asburiae ES1, Enterobacter sp. Kamsi, Enterobacter sp. AI1, and Bacillus sp. NU2 with the assigned accession number MN686602, MN686603, MN686605, MN686607, respectively. Optimisation of the laccase production via one factor at a time technique (OFAT) from the four bacteria species showed more enzyme yield in all lignocellulosic agro-waste media. However, wheat bran and mandarin peel maximally enhanced laccase production. In addition, xylose, galactose, fructose, and sorbitol were the best carbon sources utilised while (NH₄)₂SO8, KNO3 and NaNO3 were noted as the best nitrogen sources employed. Laccase yields were increased at pH 4 and 5, at temperatures 45 and 55 o C, and at 50 and 100 rpm, and precisely, at day eight of the incubation period. Further purification of the crude laccase yielded a purification fold of 4.18, 4.39, 2.78, 8.11, and the SDS-PAGE analysis showed a molecular size of 90, 55, 75 and 50 kDa for ES1, Kamsi, AI1, and NU2 laccases, respectively. The characterised purified laccase demonstrated polyextremotolerant potentials. The laccases were active through a wide temperature regime (30-90 o C) with maximum activity at 50 o C (ES1/AI1 and Kamsi/NU2) 60 o C (AI1), 70 o C (ES1, Kamsi, NU2); and were stable at 60 o C (ES1, AI1, NU2), 70 o C (ES1/AI1), 80 o C (Kamsi and Kamsi/NU2). Also, the laccases remained active through pH 3 - 8 and optimal at pH 4 (AI1, NU2), pH 5 (Kamsi, ES1/AI1), pH 7 (ES1), pH 8 (Kamsi/NU2), and the individual stability was measured at pH 4 (Kamsi, NU2), pH 5 (AI1), pH 6 (ES1), pH 7 (Kamsi/NU2), pH 10 (ES1/AI1). The purified laccases were either enhanced or left unchanged by a variable concentration of metallic salts, inhibitors, chelating agents and organic solvents. Clearly, the activities of the laccase were enhanced when pre-incubated with 1, 3, and 6 mm of CuCl2, FeCl3, MgCl2, ZnCl2 and AgCl, and 1, 2, 3 mm of Triton x-100, PMSF, EDTA, Tween 20, and NaCl. Additionally, 20, 30, and 10 percent v/v of acetone and DMSO were prominent organic solvents that also stimulated both the hybrid and amalgamated laccase activity. The gene of the purified laccases targeted showed a clear band size of 690 bp for the Enterobacter species laccases and 775 bp for the laccase from Bacillus sp. The protein sequence was deposited in NCBI database with the assigned accession numbers, MW251989, MW25990, MW251992, and MW251994 for ES1, Kamsi, AI1, and NU2 laccases, respectively. The optimised pH and temperature parameter examined on the decolourising potential of the bacteria laccases showed an effective dye removal on the five synthetic dyes (Congo Red (CR), Methyl Orange (MO), Malachite Green (MG), Reactive Blue 4 (RB4), Ramazol Brilliant Blue R (RBBR)) applied. The purified laccases were successfully immobilised in Na-alginate with cca. 88.49, 70.91, 76.04, 76.13, 90.07, and 91.99 laccase yield for the hybrid (ES1, ES1, Kamsi, AI1, NU2) and amalgamated (ES1/AI1 and Kamsi/NU2) laccases. The immobilised laccases were able to retain an average activity of 32 – 52 percent after eight dye decolourising cycles, exhibiting strong catalytic activity than the free laccases. Nonetheless, no significant difference was examined between the hybrid and amalgamated laccase activity. Also, the immobilised laccases were shown to be more efficient in biotechnological application than the free laccases. The result suggests that immobilising an enzyme in a carrier matrix served effectively as the remediation approach than the hybrid and the amalgamation of the free enzymes. Also, the application of lignocellulosic waste served as a cheaper substrate for commercial production of laccase and could help s in promoting es the biotechnology application and the bioeconomy. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-09
- Authors: Edoamodu, Chiedu Epiphany https://orcid.org/0000-0002-9254-3955
- Date: 2021-09
- Subjects: Laccase , Water -- Purification
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22820 , vital:52802
- Description: The continuous outpour of aromatic pollutants in diverse groups, emanating from the industrial and domestic system due to population density, industrialisation and technological advancement is alarming. The increasing strength in wastewater discharge constitutes the main cause of the natural water pollution load, causing scarcity of potable water for consumption with an increasing health challenge. The physiochemical treatment approach has faced a series of limitations with little or no success. Hindrance to wastewater management can cause a point source contamination problem that might increase treatment cost and release a broad range of chemical contaminants in the environment. Hence, green, eco-friendly and cost-effective tools are imperative. The application of laccase has received much attention in bioremediation and bioprocessing matters owing to the oxidising capacity of a wide range of substrates. The process requires available molecular oxygen for its activation, releasing water as a by-product thus, establishing this research. This study was devised to examine the bioprocessing potentials of hybrid and amalgamated laccases extracted from the diverse environmental milieu of the Eastern Cape Province, South Africa. Bacteria producing laccase were isolated from marine sediment, cow dung, and wastewater samples via selective enrichment with some aromatic compounds. The axenic cultures were screened for laccase activity on various phenolic and non-phenolic substrates. The isolates were identified via molecular techniques and they belonged to the gammaproteobacteria and Bacilli classes under the following genera, Enterobacter and Bacillus. They were deposited in the NCBI database as Enterobacter asburiae ES1, Enterobacter sp. Kamsi, Enterobacter sp. AI1, and Bacillus sp. NU2 with the assigned accession number MN686602, MN686603, MN686605, MN686607, respectively. Optimisation of the laccase production via one factor at a time technique (OFAT) from the four bacteria species showed more enzyme yield in all lignocellulosic agro-waste media. However, wheat bran and mandarin peel maximally enhanced laccase production. In addition, xylose, galactose, fructose, and sorbitol were the best carbon sources utilised while (NH₄)₂SO8, KNO3 and NaNO3 were noted as the best nitrogen sources employed. Laccase yields were increased at pH 4 and 5, at temperatures 45 and 55 o C, and at 50 and 100 rpm, and precisely, at day eight of the incubation period. Further purification of the crude laccase yielded a purification fold of 4.18, 4.39, 2.78, 8.11, and the SDS-PAGE analysis showed a molecular size of 90, 55, 75 and 50 kDa for ES1, Kamsi, AI1, and NU2 laccases, respectively. The characterised purified laccase demonstrated polyextremotolerant potentials. The laccases were active through a wide temperature regime (30-90 o C) with maximum activity at 50 o C (ES1/AI1 and Kamsi/NU2) 60 o C (AI1), 70 o C (ES1, Kamsi, NU2); and were stable at 60 o C (ES1, AI1, NU2), 70 o C (ES1/AI1), 80 o C (Kamsi and Kamsi/NU2). Also, the laccases remained active through pH 3 - 8 and optimal at pH 4 (AI1, NU2), pH 5 (Kamsi, ES1/AI1), pH 7 (ES1), pH 8 (Kamsi/NU2), and the individual stability was measured at pH 4 (Kamsi, NU2), pH 5 (AI1), pH 6 (ES1), pH 7 (Kamsi/NU2), pH 10 (ES1/AI1). The purified laccases were either enhanced or left unchanged by a variable concentration of metallic salts, inhibitors, chelating agents and organic solvents. Clearly, the activities of the laccase were enhanced when pre-incubated with 1, 3, and 6 mm of CuCl2, FeCl3, MgCl2, ZnCl2 and AgCl, and 1, 2, 3 mm of Triton x-100, PMSF, EDTA, Tween 20, and NaCl. Additionally, 20, 30, and 10 percent v/v of acetone and DMSO were prominent organic solvents that also stimulated both the hybrid and amalgamated laccase activity. The gene of the purified laccases targeted showed a clear band size of 690 bp for the Enterobacter species laccases and 775 bp for the laccase from Bacillus sp. The protein sequence was deposited in NCBI database with the assigned accession numbers, MW251989, MW25990, MW251992, and MW251994 for ES1, Kamsi, AI1, and NU2 laccases, respectively. The optimised pH and temperature parameter examined on the decolourising potential of the bacteria laccases showed an effective dye removal on the five synthetic dyes (Congo Red (CR), Methyl Orange (MO), Malachite Green (MG), Reactive Blue 4 (RB4), Ramazol Brilliant Blue R (RBBR)) applied. The purified laccases were successfully immobilised in Na-alginate with cca. 88.49, 70.91, 76.04, 76.13, 90.07, and 91.99 laccase yield for the hybrid (ES1, ES1, Kamsi, AI1, NU2) and amalgamated (ES1/AI1 and Kamsi/NU2) laccases. The immobilised laccases were able to retain an average activity of 32 – 52 percent after eight dye decolourising cycles, exhibiting strong catalytic activity than the free laccases. Nonetheless, no significant difference was examined between the hybrid and amalgamated laccase activity. Also, the immobilised laccases were shown to be more efficient in biotechnological application than the free laccases. The result suggests that immobilising an enzyme in a carrier matrix served effectively as the remediation approach than the hybrid and the amalgamation of the free enzymes. Also, the application of lignocellulosic waste served as a cheaper substrate for commercial production of laccase and could help s in promoting es the biotechnology application and the bioeconomy. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-09
In vitro investigation of the anti-hyperglycemic and chemical composition of Heteromorpha arborescens (Spreng.) Cham leaf extracts used in the management of diabetes mellitus
- Abifarin, Taiwo Oluwafunmilola https://orcid.org/00000003-4994-4638
- Authors: Abifarin, Taiwo Oluwafunmilola https://orcid.org/00000003-4994-4638
- Date: 2021-09
- Subjects: Diabetes
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22798 , vital:52760
- Description: Diabetes mellitus is currently a major threat all over the world. It is a chronic disorder characterized by elevated blood glucose levels and disturbance in carbohydrate, fat and protein metabolism which often times leads to several complications such as, atherosclerosis, diabetic nephropathy, retinopathy and neuropathy. Due to the side effects associated with synthetic oral hypoglycemic drugs, herbal remedies have become the alternative in the management of diabetes mellitus. Heteromorpha arborescens is one of the many plants used as herbal remedies for the management of diabetes mellitus in South Africa. In addition, the roots, barks and leaves are used in other parts of Southern Africa for the treatment of mental problems, asthma, cough, dysentery and tuberculosis. The roots are fed to malnourished children in Botswana and Swaziland. However, despite the high medicinal importance, there is little or no scientificinformation to prove this claim. Therefore, the basis of this study is to determine the chemical composition as well as perform and invitro investigation of the antihyperglycemic potential of H. arborescens leaf extracts to provide information that could validate the ethno-medicinal claims for the use of this plant in the management of diabetes mellitus. Phytochemical contents and antioxidant activity of the leaf extracts were determined. Phytochemical analysis of the acetone, ethanol, aqueous and blanched extracts of H. arborescens leaves indicated that the total phenol content of the extracts ranged between 15.10 mg GAE/g- 42.50 mg QAE/g, proanthocyanidin, 459-8402.1 mg QE/g and the flavonoid content, 109.24- 235.79 mg QE/g. In addition, alkaloids (7.65percent) and saponin (25.33percent) were present in significantamounts. Based on the IC50 values, the ethanol extract exhibited the highest total antioxidant activity (0.0125 mg/mL) with highest inhibition against DPPH and ABTS radicals (0.06 and 0.049 mg/mL respectively). Relatively high antioxidant activity may be attributed to the polyphenolic contents which possess hypoglycemic potentials. Minimum Inhibitory Concentrations (MIC) of H. arborescens leaf extracts against Bacillus pumilus, Staphylococcus epidermidis, Staphylococcus aureus, Escherichia coli and Klebselia pneumoniae was also determined and results indicated considerable antibacterial activity in the acetone, ethanol and blanched extracts with MIC values ranging from 1.563-12.5 mg/mL; however, the aqueous extract was inactive against all the bacteria strains. The antibacterial activity of the leaf extracts could be advantageous against diabetic related infections. The cytotoxicity, anti-obesity and antidiabetic potentials of blanched, aqueous and ethanol extracts of Heteromorpha arborescens (Spreng.) Cham leaves were also investigated. The results revealed that both ethanol and aqueous extracts indicated considerable inhibition against α-glucosidase (IC50 of 627.29 ± 4.33 μg/mL and 576.46 ± 3.21 μg/mL respectively) while the blanched extract showed weak α- glucosidase inhibition (IC50; 855.38 ± 4.29 μg/mL). The aqueous extract showed the best α- amylase inhibition (IC50; 583.74 ± 5.87 μg/mL) among the assessed extracts. However, weak α- amylase inhibition was observed in the ethanol (IC50; 724.60 ± 4.33 μg/mL) and blanched extracts (IC50; 791.63 ± 3.76 μg/mL) of H. arborescens leaves. Some level of glucose utilization in both C3A and L6 cells was also observed for the aqueous and ethanol extracts which may be attributed to the relatively lower toxicity levels present in them, however, glucose utilization was very weak for the blanched extract, which may be due to higher level of cytotoxicity it possessed. Relatively weak lipase inhibition was observed for the ethanol (IC50; 699.3 ± 1.33 μg/mL), aqueous (IC50; 811.52 ± 3.52 μg/mL) and blanched extract (IC50; 1152.7 ± 4.61 μg/mL) as compared to orlistat (IC50; 56.88 ± 0.11 μg/mL). However, there was no reasonable reduction in lipid accumulation observed in all the extract treated cells. The results obtained suggest that H.arborescens leaf extracts can serve as a potential tool for the development of new strategies for the treatment of diabetes and obesity. However, further analysis is required to ascertain its anti- obesity potential. Also, caution should be taken in the use of the plant at high concentrations in order to ensure safety and efficacy. Analyses were also carried out to determine the nutritional and antinutritional constituents of the plant for possible inclusion in the diet of diabetic patients. Proximate analysis revealed the presence of 8.5 percent total ash, 4.92 percent crude fat, 8.41 percent moisture, 15.74 percent crude protein, 21.48 percent crude fiber, 40.95 percent carbohydrates and 271.04 kcal/100g energy value. Mineral analysis showed that H. arborescens leaves are very rich in K, Ca, and Fe. Considerable amounts of Mg, Mn, Na, P, Cu and Zn were also present. Vitamin analysis showed that the plant has a high content of vitamins A, C and E. The anti-nutrients evaluated were phytate, oxalate, saponin, and alkaloids, all of which were below toxic levels except for saponin which was observed in moderately high level. This study revealed that H. arborescens leaves are a good source of nutrients and mineral elements, (with low anti-nutrient content) that are highly beneficial to human health especially in diabetic individuals, therefore, encouraging its possible inclusion as a vegetable. Essential oil composition of fresh Heteromorphaarborescens leaves were also determined by Solvent-Free-Microwave-Extraction (SFME) and Hydrodistillation (HD) methods and the compositions of both mehods were compared in terms of their chemical compositions, yield, CO2 emission and energy consumption. Solvent Free Microwave extraction method indicated higher oil yield of 0.7 mL/200 g (0.35 percent) as compared to 0.59 mL/200 g (0.295 percent), lower energy consumption and CO2 emission as compared to the hydrodistillation method. In conclusion, H. arborescens leaves indicated considerable potential efficacy in the management for diabetes mellitus and may require further structural elucidation and characterization in order to identify the bioactive constituents. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-09
- Authors: Abifarin, Taiwo Oluwafunmilola https://orcid.org/00000003-4994-4638
- Date: 2021-09
- Subjects: Diabetes
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22798 , vital:52760
- Description: Diabetes mellitus is currently a major threat all over the world. It is a chronic disorder characterized by elevated blood glucose levels and disturbance in carbohydrate, fat and protein metabolism which often times leads to several complications such as, atherosclerosis, diabetic nephropathy, retinopathy and neuropathy. Due to the side effects associated with synthetic oral hypoglycemic drugs, herbal remedies have become the alternative in the management of diabetes mellitus. Heteromorpha arborescens is one of the many plants used as herbal remedies for the management of diabetes mellitus in South Africa. In addition, the roots, barks and leaves are used in other parts of Southern Africa for the treatment of mental problems, asthma, cough, dysentery and tuberculosis. The roots are fed to malnourished children in Botswana and Swaziland. However, despite the high medicinal importance, there is little or no scientificinformation to prove this claim. Therefore, the basis of this study is to determine the chemical composition as well as perform and invitro investigation of the antihyperglycemic potential of H. arborescens leaf extracts to provide information that could validate the ethno-medicinal claims for the use of this plant in the management of diabetes mellitus. Phytochemical contents and antioxidant activity of the leaf extracts were determined. Phytochemical analysis of the acetone, ethanol, aqueous and blanched extracts of H. arborescens leaves indicated that the total phenol content of the extracts ranged between 15.10 mg GAE/g- 42.50 mg QAE/g, proanthocyanidin, 459-8402.1 mg QE/g and the flavonoid content, 109.24- 235.79 mg QE/g. In addition, alkaloids (7.65percent) and saponin (25.33percent) were present in significantamounts. Based on the IC50 values, the ethanol extract exhibited the highest total antioxidant activity (0.0125 mg/mL) with highest inhibition against DPPH and ABTS radicals (0.06 and 0.049 mg/mL respectively). Relatively high antioxidant activity may be attributed to the polyphenolic contents which possess hypoglycemic potentials. Minimum Inhibitory Concentrations (MIC) of H. arborescens leaf extracts against Bacillus pumilus, Staphylococcus epidermidis, Staphylococcus aureus, Escherichia coli and Klebselia pneumoniae was also determined and results indicated considerable antibacterial activity in the acetone, ethanol and blanched extracts with MIC values ranging from 1.563-12.5 mg/mL; however, the aqueous extract was inactive against all the bacteria strains. The antibacterial activity of the leaf extracts could be advantageous against diabetic related infections. The cytotoxicity, anti-obesity and antidiabetic potentials of blanched, aqueous and ethanol extracts of Heteromorpha arborescens (Spreng.) Cham leaves were also investigated. The results revealed that both ethanol and aqueous extracts indicated considerable inhibition against α-glucosidase (IC50 of 627.29 ± 4.33 μg/mL and 576.46 ± 3.21 μg/mL respectively) while the blanched extract showed weak α- glucosidase inhibition (IC50; 855.38 ± 4.29 μg/mL). The aqueous extract showed the best α- amylase inhibition (IC50; 583.74 ± 5.87 μg/mL) among the assessed extracts. However, weak α- amylase inhibition was observed in the ethanol (IC50; 724.60 ± 4.33 μg/mL) and blanched extracts (IC50; 791.63 ± 3.76 μg/mL) of H. arborescens leaves. Some level of glucose utilization in both C3A and L6 cells was also observed for the aqueous and ethanol extracts which may be attributed to the relatively lower toxicity levels present in them, however, glucose utilization was very weak for the blanched extract, which may be due to higher level of cytotoxicity it possessed. Relatively weak lipase inhibition was observed for the ethanol (IC50; 699.3 ± 1.33 μg/mL), aqueous (IC50; 811.52 ± 3.52 μg/mL) and blanched extract (IC50; 1152.7 ± 4.61 μg/mL) as compared to orlistat (IC50; 56.88 ± 0.11 μg/mL). However, there was no reasonable reduction in lipid accumulation observed in all the extract treated cells. The results obtained suggest that H.arborescens leaf extracts can serve as a potential tool for the development of new strategies for the treatment of diabetes and obesity. However, further analysis is required to ascertain its anti- obesity potential. Also, caution should be taken in the use of the plant at high concentrations in order to ensure safety and efficacy. Analyses were also carried out to determine the nutritional and antinutritional constituents of the plant for possible inclusion in the diet of diabetic patients. Proximate analysis revealed the presence of 8.5 percent total ash, 4.92 percent crude fat, 8.41 percent moisture, 15.74 percent crude protein, 21.48 percent crude fiber, 40.95 percent carbohydrates and 271.04 kcal/100g energy value. Mineral analysis showed that H. arborescens leaves are very rich in K, Ca, and Fe. Considerable amounts of Mg, Mn, Na, P, Cu and Zn were also present. Vitamin analysis showed that the plant has a high content of vitamins A, C and E. The anti-nutrients evaluated were phytate, oxalate, saponin, and alkaloids, all of which were below toxic levels except for saponin which was observed in moderately high level. This study revealed that H. arborescens leaves are a good source of nutrients and mineral elements, (with low anti-nutrient content) that are highly beneficial to human health especially in diabetic individuals, therefore, encouraging its possible inclusion as a vegetable. Essential oil composition of fresh Heteromorphaarborescens leaves were also determined by Solvent-Free-Microwave-Extraction (SFME) and Hydrodistillation (HD) methods and the compositions of both mehods were compared in terms of their chemical compositions, yield, CO2 emission and energy consumption. Solvent Free Microwave extraction method indicated higher oil yield of 0.7 mL/200 g (0.35 percent) as compared to 0.59 mL/200 g (0.295 percent), lower energy consumption and CO2 emission as compared to the hydrodistillation method. In conclusion, H. arborescens leaves indicated considerable potential efficacy in the management for diabetes mellitus and may require further structural elucidation and characterization in order to identify the bioactive constituents. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-09
Investigation of pharmaceutical residues and polybrominated diphenyl ethers in selected river estuaries and canal in Eastern Cape Province, South Africa
- Ohoro, Chinemerem Ruth https://orcid.org/ 0000-0002-8167-6314
- Authors: Ohoro, Chinemerem Ruth https://orcid.org/ 0000-0002-8167-6314
- Date: 2021-09
- Subjects: Marine pharmacology
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21545 , vital:48878
- Description: The increasing global pollution by contaminants of emerging concern due to industrialization, development, and improper handling of industrial and domestic waste is alarming. Some of these emerging contaminants are endocrine disruptors and persistent organic pollutants. Two groups of compounds (pharmaceuticals and polybrominated diphenyl ethers (PBDEs)) were considered for this study. Pharmaceuticals are drugs which we take to cure and nourish human and animal bodies, ranging from antibiotics, stimulants, psychiatric, to hormonal recipes among others. They are potentially toxic and comprise chemicals or active ingredients capable of disrupting hormones. They have been related to human and aquatic organisms' ecological risks, such as feminization and masculinization of fish, cancer, and disruption of the immune system. In recent times, pharmaceuticals are being tested in the Rivers of South Africa. PBDEs are human influential chemicals usually incorporated into products such as flame retardants, which can travel over a long distance. They are hydrophobic, lipophilic, environmentally persistent, and easily absorbed by aquatic organisms. About 209 congeners exist, and BDE- 17, 47, 66, 100, 153, 154, and 183 are frequently detected in the environment. The higher brominated congeners can debrominate to more toxic and lower congeners. Though they have low acute toxicity, their effect of interfering with the thyroid gland is long-term. They pose a risk such as immunological, neurological, carcinogenicity, and reproductive disruption. Water and sediment samples considered for investigation were collected from five different sites (Buffalo River Estuary, Sundays River Estuary, Swartkops River Estuary, Nahoon River Estuary, and Markman Canal stormwater). These sites are located in the two major cities hosting the two major Ports (East London and Port Elizabeth) in the Eastern Cape Province of South Africa. Five sampling points were chosen for the collection of both water and sediment samples across three seasons that span from August to December in each of the mentioned sites. Nahoon River Estuary that was not sampled in winter seasons due to logistics and the global pandemic of year 2020; sediment sample was not collected at point NH5 for the spring season because of inaccessibility and topography of the sampling point. Ultrasonic extraction was utilized for sediment samples while SPE method with C-18 cartridges, was used to extract pharmaceuticals in water samples and for the purification of sediment extracts. A chromatographic column was employed for sediment purification. Analytes considered in this study were carbamazepine, caffeine, trimethoprim, sulfamethoxazole, and testosterone. Nahoon River Estuary and Markman canal were considered for investigation of water and sediments for PBDEs. The samples were processed for analysis immediately on arrival to the laboratory after being stored in an ice chest at 4 oC. Physicochemical properties of water samples were taken on site. The temperature ranges from 15.5-24.5 oC for Markman and 24.5- 26.6 oC. Nahoon River Estuary. There was a correlation among the congeners except for BDE-153, which do not correlate with BDE- 17, 47, and 183 in Markman. However, BDE- 153 correlated with BDE-66 in Markman. The Ʃ5PBDE for water and Ʃ6PBDE sediment for all seasons were BDL – 1357 ng/L and BDL – 408.14 ng/g, respectively. The PBDEs mean concentrations in Nahoon water samples ranges from BDL-247 ng/L (spring). The dominant congeners in Nahoon Estuary and Markman Canal samples were BDE- 17 and BDE – 66. The temperature and pH of Swartkops River Estuary range from 16.66 – 25.15 oC, and 8.1 – 10.4, respectively. The pH of the Estuary was higher than that of the Markman Canal. The concentrations of pharmaceuticals in water samples were below detection limit. However, carbamazepine gave the highest concentration in sediment samples (23.86 μg/kg). SLF was not detected in sediment samples. The range of temperature for Buffalo River Estuary was lower than the other sites (18.10 – 20.22 oC); however, the pH showed no difference. Human and ecotoxicological risks were estimated for Markman Canal, Nahoon, Swartkops, Buffalo and Sundays River estuaries. The concentrations obtained for the two classes of contaminants in this study showed that PBDEs in Markman Canal sediment could pose a potential risk to humans, while Nahoon River Estuary poses no risk from PBDEs. Furthermore, the concentrations of caffeine in surface water of Sundays Estuary indicates low ecotoxicological risk to aquatic organisms (fish). Also, carbamazepine and trimethoprim levels (BDL – 9.50 and 1.39-2.00 μg/kg, respectively) suggest a high risk to aquatic organisms (bacteria, invertebrate, algae) in sediment of Buffalo, Sundays, and Swartkops estuaries, as well as Markman Canal. The situation report shows that the estuaries and canal in East London and Port Elizabeth are polluted by organic pollutants such as pharmaceuticals and polybrominated diphenyl ethers. Measures has to be taken to monitor the pollution of these rivers that are of economic value to South Africa. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-09
- Authors: Ohoro, Chinemerem Ruth https://orcid.org/ 0000-0002-8167-6314
- Date: 2021-09
- Subjects: Marine pharmacology
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21545 , vital:48878
- Description: The increasing global pollution by contaminants of emerging concern due to industrialization, development, and improper handling of industrial and domestic waste is alarming. Some of these emerging contaminants are endocrine disruptors and persistent organic pollutants. Two groups of compounds (pharmaceuticals and polybrominated diphenyl ethers (PBDEs)) were considered for this study. Pharmaceuticals are drugs which we take to cure and nourish human and animal bodies, ranging from antibiotics, stimulants, psychiatric, to hormonal recipes among others. They are potentially toxic and comprise chemicals or active ingredients capable of disrupting hormones. They have been related to human and aquatic organisms' ecological risks, such as feminization and masculinization of fish, cancer, and disruption of the immune system. In recent times, pharmaceuticals are being tested in the Rivers of South Africa. PBDEs are human influential chemicals usually incorporated into products such as flame retardants, which can travel over a long distance. They are hydrophobic, lipophilic, environmentally persistent, and easily absorbed by aquatic organisms. About 209 congeners exist, and BDE- 17, 47, 66, 100, 153, 154, and 183 are frequently detected in the environment. The higher brominated congeners can debrominate to more toxic and lower congeners. Though they have low acute toxicity, their effect of interfering with the thyroid gland is long-term. They pose a risk such as immunological, neurological, carcinogenicity, and reproductive disruption. Water and sediment samples considered for investigation were collected from five different sites (Buffalo River Estuary, Sundays River Estuary, Swartkops River Estuary, Nahoon River Estuary, and Markman Canal stormwater). These sites are located in the two major cities hosting the two major Ports (East London and Port Elizabeth) in the Eastern Cape Province of South Africa. Five sampling points were chosen for the collection of both water and sediment samples across three seasons that span from August to December in each of the mentioned sites. Nahoon River Estuary that was not sampled in winter seasons due to logistics and the global pandemic of year 2020; sediment sample was not collected at point NH5 for the spring season because of inaccessibility and topography of the sampling point. Ultrasonic extraction was utilized for sediment samples while SPE method with C-18 cartridges, was used to extract pharmaceuticals in water samples and for the purification of sediment extracts. A chromatographic column was employed for sediment purification. Analytes considered in this study were carbamazepine, caffeine, trimethoprim, sulfamethoxazole, and testosterone. Nahoon River Estuary and Markman canal were considered for investigation of water and sediments for PBDEs. The samples were processed for analysis immediately on arrival to the laboratory after being stored in an ice chest at 4 oC. Physicochemical properties of water samples were taken on site. The temperature ranges from 15.5-24.5 oC for Markman and 24.5- 26.6 oC. Nahoon River Estuary. There was a correlation among the congeners except for BDE-153, which do not correlate with BDE- 17, 47, and 183 in Markman. However, BDE- 153 correlated with BDE-66 in Markman. The Ʃ5PBDE for water and Ʃ6PBDE sediment for all seasons were BDL – 1357 ng/L and BDL – 408.14 ng/g, respectively. The PBDEs mean concentrations in Nahoon water samples ranges from BDL-247 ng/L (spring). The dominant congeners in Nahoon Estuary and Markman Canal samples were BDE- 17 and BDE – 66. The temperature and pH of Swartkops River Estuary range from 16.66 – 25.15 oC, and 8.1 – 10.4, respectively. The pH of the Estuary was higher than that of the Markman Canal. The concentrations of pharmaceuticals in water samples were below detection limit. However, carbamazepine gave the highest concentration in sediment samples (23.86 μg/kg). SLF was not detected in sediment samples. The range of temperature for Buffalo River Estuary was lower than the other sites (18.10 – 20.22 oC); however, the pH showed no difference. Human and ecotoxicological risks were estimated for Markman Canal, Nahoon, Swartkops, Buffalo and Sundays River estuaries. The concentrations obtained for the two classes of contaminants in this study showed that PBDEs in Markman Canal sediment could pose a potential risk to humans, while Nahoon River Estuary poses no risk from PBDEs. Furthermore, the concentrations of caffeine in surface water of Sundays Estuary indicates low ecotoxicological risk to aquatic organisms (fish). Also, carbamazepine and trimethoprim levels (BDL – 9.50 and 1.39-2.00 μg/kg, respectively) suggest a high risk to aquatic organisms (bacteria, invertebrate, algae) in sediment of Buffalo, Sundays, and Swartkops estuaries, as well as Markman Canal. The situation report shows that the estuaries and canal in East London and Port Elizabeth are polluted by organic pollutants such as pharmaceuticals and polybrominated diphenyl ethers. Measures has to be taken to monitor the pollution of these rivers that are of economic value to South Africa. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-09
Participation of smallholder farmers in the production of high-value commodities: The case of smallholder tobacco farmers in
- Authors: Mugande, Unity
- Date: 2021-09
- Subjects: Farms, Small -- Zimbabwe , Sustainable development -- Zimbabwe
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21533 , vital:48864
- Description: Participation in the production of high-value export commodities is important in increasing incomes and in enhancing smallholder farmers’ livelihoods. However, the level of their participation may be limited by several factors. Despite the limiting factors, smallholder tobacco farming has gained popularity, especially for the Zimbabwean tobacco industry. Since the Fast Track Land Reform Programme (FTLRP), the tobacco industry in Zimbabwe has seen an influx of smallholder farmers who have since dominated the industry producing over half of the national total tobacco output. The participation by smallholder farmers in tobacco production can be influenced by many factors, the main being income realisation. However, for farmers to realise reasonable incomes, they should be able to produce reasonable levels of good quality tobacco otherwise their farming would be in vain. It has been shown in the literature that smallholder farmers can be constrained by several factors to produce high levels of produce and these factors may include one or more of the following; lack of capital, lack of productive assets, lack of tobacco production skills, lack of financial resources to finance productive activities properly, lack of access to land to expand production among others. Given this background, this study sought to assess the participation of smallholder farmers in tobacco production in terms of quantities and qualities produced given the differences in their productive capacities. The study utilised both primary and secondary data for analysis. Primary data were collected from individual farmers and contract firms’ representatives. The unit of analysis was the smallholder farmer. Primary data were collected through structured questionnaires and a semi-structured interview guide for the contract representatives. Secondary data for the 2018 season were obtained from TIMB. Descriptive statistics, binary logistic regression analysis and multiple linear regression analysis were used to analyse the data. The descriptive statistics results showed that; the majority of the tobacco farmers had low levels of education and they relied mainly on farm incomes for survival. Concerning farm assets, the results showed that; on average, farmers own at least one of the following traditional assets; plough, scotch cart, cattle, storage facility, tobacco curing barn, (athough among the farmers some had indicated that they do not own curing facilities but used hired facilities to cure tobacco). Modern assets like tractors, ox-drawn ridgers and truck motor vehicles were owned by only a few farmers. The results further showed that contracted farmers were more productive and produced better quality tobacco than independent tobacco producers. The binary regression results showed that Ox-drawn ridgers, ploughs, having had a contract before, pricing, distance to the market, age of the farmer, type of curing facility, number of extension visits, number of bales produced and access to credit were significant factors influencing farmers’ participation in contract farming. However, four of the tested factors; tractors, cattle, number of hectares utilised for tobacco farming and number of years in tobacco farming were insignificant in influencing participation in contract farming. The results from the multiple linear regression analysis showed that the number of hectares utilised, the number of bales produced, market preferred, household size, tobacco production training, tractors, and type of curing facility were significant factors influencing the quality of tobacco produce. The other four variables that were tested; farmer category, type of energy used, being a member of a peer group and the number of years in tobacco farming; had no significant effect on the quality of tobacco produced by smallholder farmers. The study recommended that farmers should try and invest in commercial assets such as tractors, modern curing facilities, irrigation systems and other modern equipment that have potential to highly boost production rather than traditional assets like ox-drawn ploughs. The study also recommended that farmers should aim at maximising quantity per hectare of tobacco planted rather than planting larger crop areas they are unable to finance properly. Finally, it is recommended that farmers should get training on tobacco grading to avoid product quality loses that come with improper grading. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-09
- Authors: Mugande, Unity
- Date: 2021-09
- Subjects: Farms, Small -- Zimbabwe , Sustainable development -- Zimbabwe
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21533 , vital:48864
- Description: Participation in the production of high-value export commodities is important in increasing incomes and in enhancing smallholder farmers’ livelihoods. However, the level of their participation may be limited by several factors. Despite the limiting factors, smallholder tobacco farming has gained popularity, especially for the Zimbabwean tobacco industry. Since the Fast Track Land Reform Programme (FTLRP), the tobacco industry in Zimbabwe has seen an influx of smallholder farmers who have since dominated the industry producing over half of the national total tobacco output. The participation by smallholder farmers in tobacco production can be influenced by many factors, the main being income realisation. However, for farmers to realise reasonable incomes, they should be able to produce reasonable levels of good quality tobacco otherwise their farming would be in vain. It has been shown in the literature that smallholder farmers can be constrained by several factors to produce high levels of produce and these factors may include one or more of the following; lack of capital, lack of productive assets, lack of tobacco production skills, lack of financial resources to finance productive activities properly, lack of access to land to expand production among others. Given this background, this study sought to assess the participation of smallholder farmers in tobacco production in terms of quantities and qualities produced given the differences in their productive capacities. The study utilised both primary and secondary data for analysis. Primary data were collected from individual farmers and contract firms’ representatives. The unit of analysis was the smallholder farmer. Primary data were collected through structured questionnaires and a semi-structured interview guide for the contract representatives. Secondary data for the 2018 season were obtained from TIMB. Descriptive statistics, binary logistic regression analysis and multiple linear regression analysis were used to analyse the data. The descriptive statistics results showed that; the majority of the tobacco farmers had low levels of education and they relied mainly on farm incomes for survival. Concerning farm assets, the results showed that; on average, farmers own at least one of the following traditional assets; plough, scotch cart, cattle, storage facility, tobacco curing barn, (athough among the farmers some had indicated that they do not own curing facilities but used hired facilities to cure tobacco). Modern assets like tractors, ox-drawn ridgers and truck motor vehicles were owned by only a few farmers. The results further showed that contracted farmers were more productive and produced better quality tobacco than independent tobacco producers. The binary regression results showed that Ox-drawn ridgers, ploughs, having had a contract before, pricing, distance to the market, age of the farmer, type of curing facility, number of extension visits, number of bales produced and access to credit were significant factors influencing farmers’ participation in contract farming. However, four of the tested factors; tractors, cattle, number of hectares utilised for tobacco farming and number of years in tobacco farming were insignificant in influencing participation in contract farming. The results from the multiple linear regression analysis showed that the number of hectares utilised, the number of bales produced, market preferred, household size, tobacco production training, tractors, and type of curing facility were significant factors influencing the quality of tobacco produce. The other four variables that were tested; farmer category, type of energy used, being a member of a peer group and the number of years in tobacco farming; had no significant effect on the quality of tobacco produced by smallholder farmers. The study recommended that farmers should try and invest in commercial assets such as tractors, modern curing facilities, irrigation systems and other modern equipment that have potential to highly boost production rather than traditional assets like ox-drawn ploughs. The study also recommended that farmers should aim at maximising quantity per hectare of tobacco planted rather than planting larger crop areas they are unable to finance properly. Finally, it is recommended that farmers should get training on tobacco grading to avoid product quality loses that come with improper grading. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-09
Social media influence on graduateness skills and employability: the case of historically disadvantaged institutions.
- Authors: Murire, Obrain T
- Date: 2021-09
- Subjects: Social media--Influence
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/20383 , vital:45660
- Description: Orientation: The graduate labour force is increasing as more students are graduating from historically disadvantaged institutions (HDIs). The lack of graduateness attributes amongst final year students has in part contributed to the high rate of graduate unemployment in South Africa. Social media have been identified as a solution as more than 95percent of young adults enrolled at historically disadvantaged institutions in South Africa are using mobile technology. Research Purpose: The purpose of the study was to develop a model to enhance graduateness skills and employability through the use of social media amongst final year students at HDIs in the Eastern Cape Province of South Africa. Motivation for the study: The study is of utmost importance as it has developed an artefact that investigated the influence of social media use on graduateness skills and employability amongst students at HDIs in the Eastern Cape Province of South Africa. Additionally, students at HDIs are an interesting theoretical sample due to them being an under-researched sample. The HDIs context has received scant focus and attention. In theory, the link between psychological constructs (such as graduateness skills and employability) with a technology dimension especially within our South African context and internationally remains unexplored. Research approach/design and method: Social Media Integration and Career EDGE models were used as a theoretical foundation in this study. This study adopted design science as a research method, where a mixed-method technique was used to collect data from final year students and human resource practitioners. The sequential exploratory design was chosen as it offers an iterative process of developing an artefact that can be tested within a larger population. The questionnaire for interviews and the survey were developed after a thorough literature review and pilot study had been conducted. The questionnaire was distributed to all the participants, of which 411 responded, resulting in a response rate of 93percent; and 15 interviews were conducted. Descriptive statistics were used to analyse the data and correlations test were used to determine associations between variables. Main findings: The study found that there is a significant direct effect of social media use on graduateness skills; there is a significant direct effect of graduateness skills on perceived employability. Graduateness skills have a significant mediating effect on the relationship between social media use and perceived employability. The results also revealed that the direct effect of social media use on perceived employability does not exist. Practical/managerial implications: The study shows that there is a need for the government to devise policies that set guidelines for HR practitioners to follow when recruiting and selecting graduates. Contribution/value-add: The research study contributes to the growing body of research as it utilised a mixed-method approach to explore lived experiences. The Graduate Employability Social Media Model (GESM Model) is the main contribution made by this study to the body of knowledge in both the fields of Information Systems and Business Management. , Thesis (PhD) (Information Systems) -- University of Fort Hare, 2021.
- Full Text:
- Date Issued: 2021-09
- Authors: Murire, Obrain T
- Date: 2021-09
- Subjects: Social media--Influence
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/20383 , vital:45660
- Description: Orientation: The graduate labour force is increasing as more students are graduating from historically disadvantaged institutions (HDIs). The lack of graduateness attributes amongst final year students has in part contributed to the high rate of graduate unemployment in South Africa. Social media have been identified as a solution as more than 95percent of young adults enrolled at historically disadvantaged institutions in South Africa are using mobile technology. Research Purpose: The purpose of the study was to develop a model to enhance graduateness skills and employability through the use of social media amongst final year students at HDIs in the Eastern Cape Province of South Africa. Motivation for the study: The study is of utmost importance as it has developed an artefact that investigated the influence of social media use on graduateness skills and employability amongst students at HDIs in the Eastern Cape Province of South Africa. Additionally, students at HDIs are an interesting theoretical sample due to them being an under-researched sample. The HDIs context has received scant focus and attention. In theory, the link between psychological constructs (such as graduateness skills and employability) with a technology dimension especially within our South African context and internationally remains unexplored. Research approach/design and method: Social Media Integration and Career EDGE models were used as a theoretical foundation in this study. This study adopted design science as a research method, where a mixed-method technique was used to collect data from final year students and human resource practitioners. The sequential exploratory design was chosen as it offers an iterative process of developing an artefact that can be tested within a larger population. The questionnaire for interviews and the survey were developed after a thorough literature review and pilot study had been conducted. The questionnaire was distributed to all the participants, of which 411 responded, resulting in a response rate of 93percent; and 15 interviews were conducted. Descriptive statistics were used to analyse the data and correlations test were used to determine associations between variables. Main findings: The study found that there is a significant direct effect of social media use on graduateness skills; there is a significant direct effect of graduateness skills on perceived employability. Graduateness skills have a significant mediating effect on the relationship between social media use and perceived employability. The results also revealed that the direct effect of social media use on perceived employability does not exist. Practical/managerial implications: The study shows that there is a need for the government to devise policies that set guidelines for HR practitioners to follow when recruiting and selecting graduates. Contribution/value-add: The research study contributes to the growing body of research as it utilised a mixed-method approach to explore lived experiences. The Graduate Employability Social Media Model (GESM Model) is the main contribution made by this study to the body of knowledge in both the fields of Information Systems and Business Management. , Thesis (PhD) (Information Systems) -- University of Fort Hare, 2021.
- Full Text:
- Date Issued: 2021-09
The escalation of gender war within post-colonial South African society: an interrogation of beauty’s gift by Sindiwe Magona, happiness is a four-letter word by Cynthia Jele and black widow society by Angela Makholwa
- Authors: Goremusandu, Tania
- Date: 2021-09
- Subjects: Women and literature -- Africa , Women in literature
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21927 , vital:51843
- Description: The critical analysis of gender war in the African context is not a new venture but it is rather a significant discussion to the development of gender and feminist theories. The primary focus of this study is to investigate the limitations to empowerment that African women face at the hands of a post-colonial patriarchal society like South Africa, exacerbated by the oppression and subjugation employed by patriarchal and cultural norms. Thus, the research provides a comparative analysis of three contemporary novels by award winning South African women writers in African literature: Sindiwe Magona, Cynthia Jele and Angela Makholwa. These three dedicated women writers examine the different ways in which African patriarchy and culture oppress professional, educated women. Their work portray gender and / or female oppression and the stereotypes experienced by African women in the context of post-colonial, heavily patriarchal South African society. Therefore, this study interrogates the experience of South African women, as explored in the texts, revealing the literary expressions of gender oppression as well as the possibilities of empowerment. In addition, the texts are analysed through the lens of the Feminist literary criticism theory, Gender studies and African feminism. Through the examination offered by these theories, the study focuses on the experiences of South African women, as expressed by the female characters in the selected texts, through a critical analysis of female oppression and resistance and on the idea that gender is constructed socially and culturally in the African context. As this project reveals, the problem arising within post-colonial South African society is that women are still oppressed and are seen as passive and submissive. As a result, patriarchal perspectives combined with women’s economic dependence on men, make reaching self-actualization a challenging and even terrifying experience, and is often impossible for most women to achieve. Thus, there is a need to understand the experiences of these women so that effective and culturally sensitive interventions can be implemented. The emergence of these renowned female South African writers together with the emancipation of African countries from colonial supremacy has opened a space for women to compensate for and correct the stereotyped female images in African literature and in post-colonial societies. Most contemporary African writers such as Chimamanda Ngozi Adichie, Tsitsi Dangarembga, Neshani Andreas, Sindiwe Magona, Cynthia Jele and Angela Makholwa have shown that women are seeking empowerment and liberation. Therefore, this study seeks to highlight such experiences through its critical interrogation of the writings of selected South African women writers and the exploration of their gender-based themes in order to inform and or inspire women empowerment. It is intended to broaden and encourage further academic discussion in the fields of Feminism literary criticism, Gender studies and African feminism as well as women’s literature within the African context. , Thesis (PhD) -- Faculty of Social Sciences and Humanities, 2021
- Full Text:
- Date Issued: 2021-09
- Authors: Goremusandu, Tania
- Date: 2021-09
- Subjects: Women and literature -- Africa , Women in literature
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21927 , vital:51843
- Description: The critical analysis of gender war in the African context is not a new venture but it is rather a significant discussion to the development of gender and feminist theories. The primary focus of this study is to investigate the limitations to empowerment that African women face at the hands of a post-colonial patriarchal society like South Africa, exacerbated by the oppression and subjugation employed by patriarchal and cultural norms. Thus, the research provides a comparative analysis of three contemporary novels by award winning South African women writers in African literature: Sindiwe Magona, Cynthia Jele and Angela Makholwa. These three dedicated women writers examine the different ways in which African patriarchy and culture oppress professional, educated women. Their work portray gender and / or female oppression and the stereotypes experienced by African women in the context of post-colonial, heavily patriarchal South African society. Therefore, this study interrogates the experience of South African women, as explored in the texts, revealing the literary expressions of gender oppression as well as the possibilities of empowerment. In addition, the texts are analysed through the lens of the Feminist literary criticism theory, Gender studies and African feminism. Through the examination offered by these theories, the study focuses on the experiences of South African women, as expressed by the female characters in the selected texts, through a critical analysis of female oppression and resistance and on the idea that gender is constructed socially and culturally in the African context. As this project reveals, the problem arising within post-colonial South African society is that women are still oppressed and are seen as passive and submissive. As a result, patriarchal perspectives combined with women’s economic dependence on men, make reaching self-actualization a challenging and even terrifying experience, and is often impossible for most women to achieve. Thus, there is a need to understand the experiences of these women so that effective and culturally sensitive interventions can be implemented. The emergence of these renowned female South African writers together with the emancipation of African countries from colonial supremacy has opened a space for women to compensate for and correct the stereotyped female images in African literature and in post-colonial societies. Most contemporary African writers such as Chimamanda Ngozi Adichie, Tsitsi Dangarembga, Neshani Andreas, Sindiwe Magona, Cynthia Jele and Angela Makholwa have shown that women are seeking empowerment and liberation. Therefore, this study seeks to highlight such experiences through its critical interrogation of the writings of selected South African women writers and the exploration of their gender-based themes in order to inform and or inspire women empowerment. It is intended to broaden and encourage further academic discussion in the fields of Feminism literary criticism, Gender studies and African feminism as well as women’s literature within the African context. , Thesis (PhD) -- Faculty of Social Sciences and Humanities, 2021
- Full Text:
- Date Issued: 2021-09
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