Catholic and charismatic: identity construction in a catholic charismatic movement in Nigeria
- Authors: Torty, Livinus
- Date: 2019
- Subjects: Catholic Church -- Nigeria , Pentecostalism -- Catholic Church Identity (Psychology) Identity (Psychology) -- Social aspects -- Nigeria
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/43787 , vital:37047
- Description: The Catholic Charismatic Renewal is a movement within the Catholic Church that blends and synthesizes elements of Catholicism and Pentecostalism. The movement straddles these two religious traditions within Christianity. Besides its incorporation of elements of Catholicism and Pentecostalism, the movement also has as its objective, the revitalizing and renewal of the Catholic Church through the power of the Holy Spirit. These fundamental orientations of the Catholic Charismatic Renewal distinguish it from other Catholic movements, bestowing on it its unique identity. Although different from other Catholic movements, the movement and its members lay claim to a Catholic identity and seek to assert its legitimacy within the Catholic Church. Existing literature has provided useful insights into the question of identity within the Catholic Charismatic Renewal. However, the question of identity construction within the movement has not been adequately and comprehensively addressed in academic literature. This is especially the case in the African context. This leaves therefore a gap in our knowledge of how the movement and its members construct their catholic and charismatic identities. This study sets out to explore how the movement and its members construct their identity in relation to the Holy Spirit, the institutional Catholic Church and other Catholics, as well as in the context of the movement’s ritual music. Identity construction in the Catholic Charismatic Renewal is seen as key to making meaning of the movement and its place within Catholicism. The study adopted a qualitative research and ethnographic approach in which empirical data was collected in the context of fieldwork through informal, semi-structured and focus group interviews as well as participant observation during the activities of a Catholic Charismatic prayer group in Minna, Nigeria. Theoretical perspectives drawn from identity, hermeneutics and anthropology of extraordinary experience were used as analytical lens in the study. The study revealed that identity within the Catholic Charismatic Renewal was constructed principally in relation to the Holy Spirit. A spiritual experience or encounter was central in such identity construction, and the subjective and intersubjective identity of the members revolved around the two key concepts of ‘spirit-centred identity’ and ‘empowerment’. The study indicated that the members of the movement constructed their identity in ways that demonstrated their loyalty to the Church and their status as an officially recognised Catholic movement. In addition, their identity was also constructed in relation to the functions that they perceived themselves to perform within the Catholic Church. Although the members of the movement considered their charismatic and catholic identities to be compatible, they understood themselves to be different from other Catholics. The study also showed that while music was considered to be important within the movement, the context and content of its ritual music were overwhelmingly Pentecostal, and music that projected a catholic identity was relegated to the background and given expression mainly in the realm of individual religious practice. The study suggests that identity construction within the Catholic Charismatic Renewal is multiple, ongoing, flexible, and sometimes contradictory and paradoxical. Through its identity construction, the members of the movement demonstrate the heterogeneity of the Catholic space and seek to extend the boundaries of Catholicism.
- Full Text:
- Date Issued: 2019
- Authors: Torty, Livinus
- Date: 2019
- Subjects: Catholic Church -- Nigeria , Pentecostalism -- Catholic Church Identity (Psychology) Identity (Psychology) -- Social aspects -- Nigeria
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/43787 , vital:37047
- Description: The Catholic Charismatic Renewal is a movement within the Catholic Church that blends and synthesizes elements of Catholicism and Pentecostalism. The movement straddles these two religious traditions within Christianity. Besides its incorporation of elements of Catholicism and Pentecostalism, the movement also has as its objective, the revitalizing and renewal of the Catholic Church through the power of the Holy Spirit. These fundamental orientations of the Catholic Charismatic Renewal distinguish it from other Catholic movements, bestowing on it its unique identity. Although different from other Catholic movements, the movement and its members lay claim to a Catholic identity and seek to assert its legitimacy within the Catholic Church. Existing literature has provided useful insights into the question of identity within the Catholic Charismatic Renewal. However, the question of identity construction within the movement has not been adequately and comprehensively addressed in academic literature. This is especially the case in the African context. This leaves therefore a gap in our knowledge of how the movement and its members construct their catholic and charismatic identities. This study sets out to explore how the movement and its members construct their identity in relation to the Holy Spirit, the institutional Catholic Church and other Catholics, as well as in the context of the movement’s ritual music. Identity construction in the Catholic Charismatic Renewal is seen as key to making meaning of the movement and its place within Catholicism. The study adopted a qualitative research and ethnographic approach in which empirical data was collected in the context of fieldwork through informal, semi-structured and focus group interviews as well as participant observation during the activities of a Catholic Charismatic prayer group in Minna, Nigeria. Theoretical perspectives drawn from identity, hermeneutics and anthropology of extraordinary experience were used as analytical lens in the study. The study revealed that identity within the Catholic Charismatic Renewal was constructed principally in relation to the Holy Spirit. A spiritual experience or encounter was central in such identity construction, and the subjective and intersubjective identity of the members revolved around the two key concepts of ‘spirit-centred identity’ and ‘empowerment’. The study indicated that the members of the movement constructed their identity in ways that demonstrated their loyalty to the Church and their status as an officially recognised Catholic movement. In addition, their identity was also constructed in relation to the functions that they perceived themselves to perform within the Catholic Church. Although the members of the movement considered their charismatic and catholic identities to be compatible, they understood themselves to be different from other Catholics. The study also showed that while music was considered to be important within the movement, the context and content of its ritual music were overwhelmingly Pentecostal, and music that projected a catholic identity was relegated to the background and given expression mainly in the realm of individual religious practice. The study suggests that identity construction within the Catholic Charismatic Renewal is multiple, ongoing, flexible, and sometimes contradictory and paradoxical. Through its identity construction, the members of the movement demonstrate the heterogeneity of the Catholic space and seek to extend the boundaries of Catholicism.
- Full Text:
- Date Issued: 2019
Conflict transformation and campus protests at Rhodes University, 2015 - 2016
- Authors: Hunter, Andrew John
- Date: 2019
- Subjects: Student strikes -- South Africa -- Grahamstown , College students -- Political activity -- South Africa -- Grahamstown Protest movements -- South Africa Conflict management
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/40115 , vital:35756
- Description: This research explores the severe challenges of conflict resolution in the face of deep-rooted, intractable conflict. The dynamics of the student protests at Rhodes University, Grahamstown, South Africa, in 2015 and 2016 are used as a case study. There were four waves of protest at Rhodes University in 2015 and 2016: RhodesMustFall, around issues of transformation and decolonisation; FeesMustFall 2015 and 2016, with the demand for fee-free tertiary education; and ReferenceList, a protest against rape and rape culture. Each protest had its own dynamic, and provided to a greater or lesser extent the potential for resolution. The study was informed by conflict theory, models and approaches that included perspectives on decolonisation and transformation, social movement theory, conflict dynamics and conflict management strategies, rape culture and sexual violence. Key concepts were drawn from the works of Galtung on structural violence, and in particular his concept of the conflict triangle, and Lederach’s work on conflict transformation. This was qualitative research within the interpretivist paradigm. The chief sources of data were a series of semi-structured interviews; university statements and communications; statements by student protesters which appeared on social media; print and electronic media. The findings reveal that conflict resolution strategies were employed in all four protests. These succeeded in two of the protests: RhodesMustFall and FeesMustFall 2015. The other two protests – ReferenceList and FeesMustFall 2016 - ended in deadlock and hurting stalemate. The most successful negotiations were those facilitated by mediators from within the university community. There were also some significant attempts at intervention from outside. However, mediators from outside were generally unaware of the dynamics, lacked the trust from both sides, were easily open to manipulation, and failed to achieve solutions. What has emerged from this study, and which is consistent with conflict theory, are the limitations of conflict resolution strategies in situations of intractable conflict. Of particular significance was role of emotion in the protests under study. Humiliation, shame, fear and hatred all played their part. The protests saw the emergence of the tactics of “reverse humiliation”: an unconscious strategy by protesters to use humiliation and shame to undermine and weaken others. Where one or more of the parties had nothing to lose by allowing the conflict to continue, the negotiations had little prospect of success. In the context of intractable conflict and deep emotion, conflict management strategies, though useful, are of limited value. A model of a ‘peace and transformation mosaic’ of conflict resolution is proposed, and a number of recommendations for policy and strategy are made.
- Full Text:
- Date Issued: 2019
- Authors: Hunter, Andrew John
- Date: 2019
- Subjects: Student strikes -- South Africa -- Grahamstown , College students -- Political activity -- South Africa -- Grahamstown Protest movements -- South Africa Conflict management
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/40115 , vital:35756
- Description: This research explores the severe challenges of conflict resolution in the face of deep-rooted, intractable conflict. The dynamics of the student protests at Rhodes University, Grahamstown, South Africa, in 2015 and 2016 are used as a case study. There were four waves of protest at Rhodes University in 2015 and 2016: RhodesMustFall, around issues of transformation and decolonisation; FeesMustFall 2015 and 2016, with the demand for fee-free tertiary education; and ReferenceList, a protest against rape and rape culture. Each protest had its own dynamic, and provided to a greater or lesser extent the potential for resolution. The study was informed by conflict theory, models and approaches that included perspectives on decolonisation and transformation, social movement theory, conflict dynamics and conflict management strategies, rape culture and sexual violence. Key concepts were drawn from the works of Galtung on structural violence, and in particular his concept of the conflict triangle, and Lederach’s work on conflict transformation. This was qualitative research within the interpretivist paradigm. The chief sources of data were a series of semi-structured interviews; university statements and communications; statements by student protesters which appeared on social media; print and electronic media. The findings reveal that conflict resolution strategies were employed in all four protests. These succeeded in two of the protests: RhodesMustFall and FeesMustFall 2015. The other two protests – ReferenceList and FeesMustFall 2016 - ended in deadlock and hurting stalemate. The most successful negotiations were those facilitated by mediators from within the university community. There were also some significant attempts at intervention from outside. However, mediators from outside were generally unaware of the dynamics, lacked the trust from both sides, were easily open to manipulation, and failed to achieve solutions. What has emerged from this study, and which is consistent with conflict theory, are the limitations of conflict resolution strategies in situations of intractable conflict. Of particular significance was role of emotion in the protests under study. Humiliation, shame, fear and hatred all played their part. The protests saw the emergence of the tactics of “reverse humiliation”: an unconscious strategy by protesters to use humiliation and shame to undermine and weaken others. Where one or more of the parties had nothing to lose by allowing the conflict to continue, the negotiations had little prospect of success. In the context of intractable conflict and deep emotion, conflict management strategies, though useful, are of limited value. A model of a ‘peace and transformation mosaic’ of conflict resolution is proposed, and a number of recommendations for policy and strategy are made.
- Full Text:
- Date Issued: 2019
Construction material logistics management: the case of north-central Nigeria
- Authors: Alumbugu, Polycarp Olaku
- Date: 2019
- Subjects: Construction projects-- Nigeria --Management Construction projects --Management Logistics-- Nigeria -- Management , Construction industry -- Nigeria
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/44879 , vital:38179
- Description: The Management of Construction Material Logistics Systems plays a significant role in meeting the goals of cost, quality and time to completion of a construction project. Studies have revealed that the cost of construction materials is usually about 50%-60% of the total cost of the project and that the logistic cost accounts for between 17%-35% of the cost material. Fundamentally, it is accepted that any inefficiency in the delivery of construction material could lead to a time overrun and thus, a rise in construction costs addressing the operational performance of logistics would have a positive impact on the goals of a construction project. The aim of this study was to investigate and evaluate the operational performance of material logistics in North-Central Nigeria as there is little specific research conducted on its effectiveness and efficiency. The methodology used included an extensive literature review and a field study conducted on ten quantitative approach that is rooted in the positivist paradigm, and purposive sampling techniques, was adopted. The descriptive method of data analysis was employed, and the findings and interpretations presented through graphs and images. Analysis of the findings led to the conclusion that material logistics did not operate as a system. There was almost no collaboration and integration of the logistics systems to create a synergistic interrelationship between functions in pursuit of higher overall effectiveness and efficiency. Improvement was needed in warehouse and transport operations and processes; technology and automation of logistics operations were absent, and delivery of material to customers was not effective. The implication was that the current materials logistics system did not meet the delivery goals of cost, quality and time of a construction project. The recommendations suggested included the adoption of the framework developed in this study. This would serve as a guide towards effective and efficient logistics management for material manufacturing firms, and for construction professionals.
- Full Text:
- Date Issued: 2019
- Authors: Alumbugu, Polycarp Olaku
- Date: 2019
- Subjects: Construction projects-- Nigeria --Management Construction projects --Management Logistics-- Nigeria -- Management , Construction industry -- Nigeria
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/44879 , vital:38179
- Description: The Management of Construction Material Logistics Systems plays a significant role in meeting the goals of cost, quality and time to completion of a construction project. Studies have revealed that the cost of construction materials is usually about 50%-60% of the total cost of the project and that the logistic cost accounts for between 17%-35% of the cost material. Fundamentally, it is accepted that any inefficiency in the delivery of construction material could lead to a time overrun and thus, a rise in construction costs addressing the operational performance of logistics would have a positive impact on the goals of a construction project. The aim of this study was to investigate and evaluate the operational performance of material logistics in North-Central Nigeria as there is little specific research conducted on its effectiveness and efficiency. The methodology used included an extensive literature review and a field study conducted on ten quantitative approach that is rooted in the positivist paradigm, and purposive sampling techniques, was adopted. The descriptive method of data analysis was employed, and the findings and interpretations presented through graphs and images. Analysis of the findings led to the conclusion that material logistics did not operate as a system. There was almost no collaboration and integration of the logistics systems to create a synergistic interrelationship between functions in pursuit of higher overall effectiveness and efficiency. Improvement was needed in warehouse and transport operations and processes; technology and automation of logistics operations were absent, and delivery of material to customers was not effective. The implication was that the current materials logistics system did not meet the delivery goals of cost, quality and time of a construction project. The recommendations suggested included the adoption of the framework developed in this study. This would serve as a guide towards effective and efficient logistics management for material manufacturing firms, and for construction professionals.
- Full Text:
- Date Issued: 2019
Creating value through experiential marketing for mobile network operators in Ghana
- Authors: Yiadom, Michael Boakye
- Date: 2019
- Subjects: Target marketing -- Ghana , Branding (Marketing) -- Ghana Marketing -- Ghana Telecommunication -- Ghana
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/44357 , vital:37158
- Description: Experiential marketing and value creation have become paramount for businesses, worldwide, to remain competitive and sustainable. Due to the global economic crisis which put all public and private sector businesses under financial stress, experiential marketing has become necessary as a mechanism in facilitating value creation for the mobile network operators (MNOs) in Ghana to survive and to outdo their counterparts in the industry. The effective and efficient implementation of the experiential marketing programmes and campaigns, aside from helping these businesses in deriving value, could further assist the government of Ghana in its quest to develop the telecommunications industry. The government has stated that the mobile network industry of the country should be based upon the principles of open markets and fair competition, which requires strong policies and strategies in experiential marketing to create value as well as to survive. It must be noted that a unique product or service experience creates a memorable customer experience where emotion has a significant impact on business performance in terms of customer satisfaction, retention, and loyalty, as well as growth in sales and revenue and return on capital employed (ROCE). It is of the utmost importance, therefore, that network operators have the necessary resources and techniques in experiential marketing to facilitate sustainable value creation in the industry, as a lack of proper resources and implementation strategies can hinder the successful creation of value. Given this situation, this study sought to create value through experiential marketing for MNOs in Ghana. The study sought to empirically test a hypothetical model reflecting 11 independent variables on experiential marketing (i.e. mediating variables), particularly with proper attention to the experiential value gained by consumers after consumption. Also, the study addressed the contribution of all mobile components, namely processes, physical evidence, and people, in experiential marketing and creating value for businesses. The remaining hypothesis aimed at identifying the impact of the mediating variable (i.e. experiential marketing) on the dependent variable (i.e. business value) to assess how value is created through experiential marketing for MNOs in Ghana. The outcome of the primary research helped in recommending strategies that could be employed by businesses for improving competitiveness and sustainability. The debate about value creation through experiential marketing to MNOs in Ghana is not available. Consequently, this study attempted to develop a hypothetical model to provide a scientific, theoretical, and empirical contribution to MNOs, other businesses, and the entire telecommunications industry of Ghana in order to aid them in creating value through experiential marketing. To achieve the objectives of this study, a quantitative approach using a face-to-face self-administered questionnaire was adopted to test the hypotheses. The participants were randomly selected based on the 10 regions to which they belong in the country. With a visit to the regional offices of the mobile operators, the questionnaires were conveniently administered. A total of 384 participants were selected through a stratification sampling and, in addition, a total of 31 participants were conveniently added, producing a total of 415 respondents who completed the survey. Based on the analysis of various secondary sources, a hypothetical model regarding creating value through experiential marketing for MNOs in Ghana was constructed. The proposed hypothetical model indicated that the mediating variable of experiential marketing, with sub-variables related to experiential mix (i.e. sense, feel, think, act, and relate) and experiential value (i.e. emotional, functional, and social), is possibly influenced by the independent variables. This influence is also known as the mobile mix, namely 1) physical evidence with sub-variables related to the physical environment, building and spatial layout, and corporate branding; 2) process with sub-variables related to technology development, research and development, and machines and operation; and 3) people with sub-elements related to input and output logistics, marketing and customers services, human resource management, and procurement managing. The business value (i.e. the dependent variables) was identified as consisting of sales value, growth value, and return on capital employed value (ROEV). IBM’s SPSS AMOS (Version 25) was utilised for data analysis. Descriptive statistics were used to summarise the data of respondents leading to easy interpretation by the researcher. Inferential statistical analysis was utilised to test for relationships between identified variables by using a validity test, a reliability test, correlation, and a structural equation model (SEM). The empirical results revealed that the mobile mix (i.e. the independent variables) has a significant positive influence and relationship with experiential marketing (i.e. the mediating variables). On the other hand, experiential marketing was identified as having a significant positive influence on business value (i.e. the dependent variables). The majority of the respondents agreed concerning the variable items measuring experiential marketing and its influence on creating value to MNOs in Ghana. It is envisaged that the empirical evidence provided in this study could assist MNOs in Ghana in understanding the factors influencing experiential marketing and its role in creating value and, thereby, assist these businesses in strategy development and decision-making. This study provides relevant and practical recommendations that could make MNOs in Ghana generate sustainable long-term value. Thus, the objectives of this study were achieved, and the research problem was answered. This study could also act as a foundation for other studies, thereby contributing to the body of knowledge in this regard.
- Full Text:
- Date Issued: 2019
- Authors: Yiadom, Michael Boakye
- Date: 2019
- Subjects: Target marketing -- Ghana , Branding (Marketing) -- Ghana Marketing -- Ghana Telecommunication -- Ghana
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/44357 , vital:37158
- Description: Experiential marketing and value creation have become paramount for businesses, worldwide, to remain competitive and sustainable. Due to the global economic crisis which put all public and private sector businesses under financial stress, experiential marketing has become necessary as a mechanism in facilitating value creation for the mobile network operators (MNOs) in Ghana to survive and to outdo their counterparts in the industry. The effective and efficient implementation of the experiential marketing programmes and campaigns, aside from helping these businesses in deriving value, could further assist the government of Ghana in its quest to develop the telecommunications industry. The government has stated that the mobile network industry of the country should be based upon the principles of open markets and fair competition, which requires strong policies and strategies in experiential marketing to create value as well as to survive. It must be noted that a unique product or service experience creates a memorable customer experience where emotion has a significant impact on business performance in terms of customer satisfaction, retention, and loyalty, as well as growth in sales and revenue and return on capital employed (ROCE). It is of the utmost importance, therefore, that network operators have the necessary resources and techniques in experiential marketing to facilitate sustainable value creation in the industry, as a lack of proper resources and implementation strategies can hinder the successful creation of value. Given this situation, this study sought to create value through experiential marketing for MNOs in Ghana. The study sought to empirically test a hypothetical model reflecting 11 independent variables on experiential marketing (i.e. mediating variables), particularly with proper attention to the experiential value gained by consumers after consumption. Also, the study addressed the contribution of all mobile components, namely processes, physical evidence, and people, in experiential marketing and creating value for businesses. The remaining hypothesis aimed at identifying the impact of the mediating variable (i.e. experiential marketing) on the dependent variable (i.e. business value) to assess how value is created through experiential marketing for MNOs in Ghana. The outcome of the primary research helped in recommending strategies that could be employed by businesses for improving competitiveness and sustainability. The debate about value creation through experiential marketing to MNOs in Ghana is not available. Consequently, this study attempted to develop a hypothetical model to provide a scientific, theoretical, and empirical contribution to MNOs, other businesses, and the entire telecommunications industry of Ghana in order to aid them in creating value through experiential marketing. To achieve the objectives of this study, a quantitative approach using a face-to-face self-administered questionnaire was adopted to test the hypotheses. The participants were randomly selected based on the 10 regions to which they belong in the country. With a visit to the regional offices of the mobile operators, the questionnaires were conveniently administered. A total of 384 participants were selected through a stratification sampling and, in addition, a total of 31 participants were conveniently added, producing a total of 415 respondents who completed the survey. Based on the analysis of various secondary sources, a hypothetical model regarding creating value through experiential marketing for MNOs in Ghana was constructed. The proposed hypothetical model indicated that the mediating variable of experiential marketing, with sub-variables related to experiential mix (i.e. sense, feel, think, act, and relate) and experiential value (i.e. emotional, functional, and social), is possibly influenced by the independent variables. This influence is also known as the mobile mix, namely 1) physical evidence with sub-variables related to the physical environment, building and spatial layout, and corporate branding; 2) process with sub-variables related to technology development, research and development, and machines and operation; and 3) people with sub-elements related to input and output logistics, marketing and customers services, human resource management, and procurement managing. The business value (i.e. the dependent variables) was identified as consisting of sales value, growth value, and return on capital employed value (ROEV). IBM’s SPSS AMOS (Version 25) was utilised for data analysis. Descriptive statistics were used to summarise the data of respondents leading to easy interpretation by the researcher. Inferential statistical analysis was utilised to test for relationships between identified variables by using a validity test, a reliability test, correlation, and a structural equation model (SEM). The empirical results revealed that the mobile mix (i.e. the independent variables) has a significant positive influence and relationship with experiential marketing (i.e. the mediating variables). On the other hand, experiential marketing was identified as having a significant positive influence on business value (i.e. the dependent variables). The majority of the respondents agreed concerning the variable items measuring experiential marketing and its influence on creating value to MNOs in Ghana. It is envisaged that the empirical evidence provided in this study could assist MNOs in Ghana in understanding the factors influencing experiential marketing and its role in creating value and, thereby, assist these businesses in strategy development and decision-making. This study provides relevant and practical recommendations that could make MNOs in Ghana generate sustainable long-term value. Thus, the objectives of this study were achieved, and the research problem was answered. This study could also act as a foundation for other studies, thereby contributing to the body of knowledge in this regard.
- Full Text:
- Date Issued: 2019
Culturally-informed coping strategies of posttraumatic stress disorders among the black Africans in the greater Accra region of Ghana and black Africans in the eastern cape of South Africa
- Authors: Thompson, Sandra
- Date: 2019
- Subjects: Post-traumatic stress disorder -- Ghana -- Accra , Post-traumatic stress disorder -- South Africa -- Eastern Cape Cultural psychiatry Psychoanalysis and culture
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/45160 , vital:38259
- Description: The influence of culture in coping with Posttraumatic Stress Disorders (PTSD) has been highlighted in literature. However, these culture specific coping strategies are not as yet, extensively explored. The research sought to explore and describe the culturally-informed coping strategies of PTSD among the black Africans in the Greater Accra Region of Ghana and black Africans in the Eastern Cape of South Africa. A qualitative methodological approach was used to explore the phenomenon under study. Purposive non-probability sampling was employed to obtain access to participants who could inform the objectives of the study. Data was collected using semi-structured interviews with traumatised individuals and focus group discussions with cultural leaders. All interviews were audio-recorded, transcribed, translated and analysed using thematic content analysis to facilitate the description and comparison of the similarities and distinctive features emerging from the two African communities. The findings indicated that a number of cultural factors influence interpretation of symptoms of PTSD and the adopted coping strategies. Participants’ understanding of symptoms of PTSD relied heavily on Christian Religious and African cultural understandings. It was evident that almost all explanations were purely spiritual and minimal knowledge was expressed on cognitive interpretations. A great deal of emphasis by the Ghanaians and isiXhosa of South Africa, was on dreams and such interpretations were deferred to an authoritative individual (especially the traditional healer). An obvious hierarchy for coping emerged with the traditional healer playing a major role for the Ghanaian and isiXhosa participants. Performing rites and the use of plants were essential to healing for these group of individuals. Whereas, the Coloured-Afrikaans made reference to a higher power “God”. An outstanding observation was the extent to which Ghanaian and isiXhosa participants have incorporated Christian and traditional practices (i.e. praying to God, performing rites and using herbs or plants). Even where an individual did not wish to mix practice because of upbringing, they acknowledged the existence and effectiveness of these practices. Colonisation was drawn on as an explanation for such mixed practices. The advent of Christianity was explained as having established Western culture (specifically Christianity) that is incorporated by participants. The Coloured-Afrikaans on the other hand, were consistent with the Christian practices “prayers to God”. A great deal of consistency however existed among all participants. Social support was considered very important. Talking with family and friends were relevant to the healing process as it gets rid of distorted thought patterns and avoids isolation considered as a serious current threat to healing. While there was an element of cognitive understanding, Western based treatment using cognitive restructuring was not a treatment option. Clinical practitioners or Psychologists that come into contact with the black Ghanaians and black South Africans should consider collaborative treatment strategies using the draft checklist as a guide.
- Full Text:
- Date Issued: 2019
- Authors: Thompson, Sandra
- Date: 2019
- Subjects: Post-traumatic stress disorder -- Ghana -- Accra , Post-traumatic stress disorder -- South Africa -- Eastern Cape Cultural psychiatry Psychoanalysis and culture
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/45160 , vital:38259
- Description: The influence of culture in coping with Posttraumatic Stress Disorders (PTSD) has been highlighted in literature. However, these culture specific coping strategies are not as yet, extensively explored. The research sought to explore and describe the culturally-informed coping strategies of PTSD among the black Africans in the Greater Accra Region of Ghana and black Africans in the Eastern Cape of South Africa. A qualitative methodological approach was used to explore the phenomenon under study. Purposive non-probability sampling was employed to obtain access to participants who could inform the objectives of the study. Data was collected using semi-structured interviews with traumatised individuals and focus group discussions with cultural leaders. All interviews were audio-recorded, transcribed, translated and analysed using thematic content analysis to facilitate the description and comparison of the similarities and distinctive features emerging from the two African communities. The findings indicated that a number of cultural factors influence interpretation of symptoms of PTSD and the adopted coping strategies. Participants’ understanding of symptoms of PTSD relied heavily on Christian Religious and African cultural understandings. It was evident that almost all explanations were purely spiritual and minimal knowledge was expressed on cognitive interpretations. A great deal of emphasis by the Ghanaians and isiXhosa of South Africa, was on dreams and such interpretations were deferred to an authoritative individual (especially the traditional healer). An obvious hierarchy for coping emerged with the traditional healer playing a major role for the Ghanaian and isiXhosa participants. Performing rites and the use of plants were essential to healing for these group of individuals. Whereas, the Coloured-Afrikaans made reference to a higher power “God”. An outstanding observation was the extent to which Ghanaian and isiXhosa participants have incorporated Christian and traditional practices (i.e. praying to God, performing rites and using herbs or plants). Even where an individual did not wish to mix practice because of upbringing, they acknowledged the existence and effectiveness of these practices. Colonisation was drawn on as an explanation for such mixed practices. The advent of Christianity was explained as having established Western culture (specifically Christianity) that is incorporated by participants. The Coloured-Afrikaans on the other hand, were consistent with the Christian practices “prayers to God”. A great deal of consistency however existed among all participants. Social support was considered very important. Talking with family and friends were relevant to the healing process as it gets rid of distorted thought patterns and avoids isolation considered as a serious current threat to healing. While there was an element of cognitive understanding, Western based treatment using cognitive restructuring was not a treatment option. Clinical practitioners or Psychologists that come into contact with the black Ghanaians and black South Africans should consider collaborative treatment strategies using the draft checklist as a guide.
- Full Text:
- Date Issued: 2019
Data quality issues in electronic health records for large-scale databases
- Authors: Saiod, Abdul Kader
- Date: 2019
- Subjects: Electronic Health Records , Electronic Health Records--organization & administration Database management
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/44940 , vital:38190
- Description: Data Quality (DQ) in Electronic Health Records (EHRs) is one of the core functions that play a decisive role to improve the healthcare service quality. The DQ issues in EHRs are a noticeable trend to improve the introduction of an adaptive framework for interoperability and standards in Large-Scale Databases (LSDB) management systems. Therefore, large data communications are challenging in the traditional approaches to satisfy the needs of the consumers, as data is often not capture directly into the Database Management Systems (DBMS) in a seasonably enough fashion to enable their subsequent uses. In addition, large data plays a vital role in containing plenty of treasures for all the fields in the DBMS. EHRs technology provides portfolio management systems that allow HealthCare Organisations (HCOs) to deliver a higher quality of care to their patients than that which is possible with paper-based records. EHRs are in high demand for HCOs to run their daily services as increasing numbers of huge datasets occur every day. Efficient EHR systems reduce the data redundancy as well as the system application failure and increase the possibility to draw all necessary reports. However, one of the main challenges in developing efficient EHR systems is the inherent difficulty to coherently manage data from diverse heterogeneous sources. It is practically challenging to integrate diverse data into a global schema, which satisfies the need of users. The efficient management of HER systems using an existing DBMS present challenges because of incompatibility and sometimes inconsistency of data structures. As a result, no common methodological approach is currently in existence to effectively solve every data integration problem. The challenges of the DQ issue raised the need to find an efficient way to integrate large EHRs from diverse heterogeneous sources. To handle and align a large dataset efficiently, the hybrid algorithm method with the logical combination of Fuzzy-Ontology along with a large-scale EHRs analysis platform has shown the results in term of improved accuracy. This study investigated and addressed the raised DQ issues to interventions to overcome these barriers and challenges, including the provision of EHRs as they pertain to DQ and has combined features to search, extract, filter, clean and integrate data to ensure that users can coherently create new consistent data sets. The study researched the design of a hybrid method based on Fuzzy-Ontology with performed mathematical simulations based on the Markov Chain Probability Model. The similarity measurement based on dynamic Hungarian algorithm was followed by the Design Science Research (DSR) methodology, which will increase the quality of service over HCOs in adaptive frameworks.
- Full Text:
- Date Issued: 2019
- Authors: Saiod, Abdul Kader
- Date: 2019
- Subjects: Electronic Health Records , Electronic Health Records--organization & administration Database management
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/44940 , vital:38190
- Description: Data Quality (DQ) in Electronic Health Records (EHRs) is one of the core functions that play a decisive role to improve the healthcare service quality. The DQ issues in EHRs are a noticeable trend to improve the introduction of an adaptive framework for interoperability and standards in Large-Scale Databases (LSDB) management systems. Therefore, large data communications are challenging in the traditional approaches to satisfy the needs of the consumers, as data is often not capture directly into the Database Management Systems (DBMS) in a seasonably enough fashion to enable their subsequent uses. In addition, large data plays a vital role in containing plenty of treasures for all the fields in the DBMS. EHRs technology provides portfolio management systems that allow HealthCare Organisations (HCOs) to deliver a higher quality of care to their patients than that which is possible with paper-based records. EHRs are in high demand for HCOs to run their daily services as increasing numbers of huge datasets occur every day. Efficient EHR systems reduce the data redundancy as well as the system application failure and increase the possibility to draw all necessary reports. However, one of the main challenges in developing efficient EHR systems is the inherent difficulty to coherently manage data from diverse heterogeneous sources. It is practically challenging to integrate diverse data into a global schema, which satisfies the need of users. The efficient management of HER systems using an existing DBMS present challenges because of incompatibility and sometimes inconsistency of data structures. As a result, no common methodological approach is currently in existence to effectively solve every data integration problem. The challenges of the DQ issue raised the need to find an efficient way to integrate large EHRs from diverse heterogeneous sources. To handle and align a large dataset efficiently, the hybrid algorithm method with the logical combination of Fuzzy-Ontology along with a large-scale EHRs analysis platform has shown the results in term of improved accuracy. This study investigated and addressed the raised DQ issues to interventions to overcome these barriers and challenges, including the provision of EHRs as they pertain to DQ and has combined features to search, extract, filter, clean and integrate data to ensure that users can coherently create new consistent data sets. The study researched the design of a hybrid method based on Fuzzy-Ontology with performed mathematical simulations based on the Markov Chain Probability Model. The similarity measurement based on dynamic Hungarian algorithm was followed by the Design Science Research (DSR) methodology, which will increase the quality of service over HCOs in adaptive frameworks.
- Full Text:
- Date Issued: 2019
Descriptive guidelines for mediation to enhance the parental involvement of unmarried fathers
- Authors: Nordien-Lagardien, Razia
- Date: 2019
- Subjects: Mediation , Unmarried fathers -- South Africa Father and child -- South Africa Unmarried mothers -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/30462 , vital:30948
- Description: A significant change brought about by the Children’s Act 38 of 2005 (RSA, 2006), is that of the status of unmarried fathers. The parental rights of unmarried fathers have evolved in South Africa, especially since the Children’s Act 38 of 2005 (RSA, 2006) now recognises that unmarried fathers should have inherent right of contact, guardianship and care. These rights are, however, not automatic and need to be acquired through a process of mediation. While this legislation aims to facilitate the parental involvement of fathers by giving them rights as per Section 21 of the Children’s Act 38 of 2005 (RSA, 2006), the reality is that many unmarried fathers still remain challenged in this regard despite the change in their legal position as fathers. Unmarried fathers are often compelled to take the matter further through protracted court processes. Unmarried fathers face unique challenges with parental involvement after separation and they often need to negotiate their involvement with the mother after separation. Given that mediation between unmarried parents is in its infancy in South Africa, very little research has been done in this area. It was envisaged that this study would highlight the important aspects of mediation which need to be considered in order for mediation outcomes to be more successful and to enhance the co-parenting relationship. The study employed a qualitative research approach that was exploratory, descriptive and contextual in design. The research study consisted of three phases. Phase 1 employed a multiple case study design in order to develop an understanding of the experiences and perceptions of unmarried fathers and mothers, as well as mediators, regarding the parental responsibilities of unmarried fathers in addition to their experiences of mediation. The data collection process comprised in-depth semi-structured interviews with three sample groups, namely unmarried fathers, and mothers, and mediators. The data collected from the interviews were transcribed, coded and analysed by the researcher through the use of two techniques, namely: within-case analysis and cross-case synthesis. An independent coder was utilised to verify the coding and analysis process. The analysis of the data in Phase 1 revealed that the construction of the role of unmarried fathers is influenced by various factors such as cultural and religious influences; childhood experiences of fatherhood; societal constructions of the father’s role, and the perception of the legal rights of unmarried fathers. The new legislation pertaining to the responsibilities and rights of unmarried fathers, as contained in the Children’s Act 38 of 2005 (RSA, 2006), has resulted in increased parental conflict between parents after separation owing to their lack of awareness and confusion regarding the changes in legislation pertaining to the rights of unmarried fathers and the role of customary law in this regard. This has resulted in misconceptions about the legal rights of unmarried fathers, which have influenced unmarried parents’ attitudes and receptiveness to mediation. A significant barrier to father involvement emanating from the findings was relationship conflict experienced after separation, which was also identified as a significant challenge in mediation. The discussion of the themes reflected both positive and negative experiences of mediation for the study participants. While the parents derived educational and therapeutic benefits from mediation; there were also several factors such as relationship conflict, cultural barriers, influences of the extended family, and the approach and skills of the mediator, which influenced the mediation process. In Phase 2 of the study an integrative literature review and synthesis of the literature was conducted and critically appraised in terms of emergent themes and relevant research in the area of family mediation, which would inform the process of developing the descriptive guidelines for mediation with unmarried parents. The empirical findings from the study were synthesised with the findings from the integrative literature review, thus enabling conclusions to be drawn in order to generate descriptive guidelines for mediation. Phase 3 of the study describes the guidelines for mediation which emanated from the synthesis of the findings in Phase 1 and Phase 2 of the study. As part of a qualitative evaluation, the guidelines were presented to an expert panel for review, after which the guidelines were finalised. The proposed guidelines for mediation to enhance the parental involvement of unmarried fathers is based on the hybrid model of mediation, which incorporates elements from the Transformative approach, the African centred approach and the co-mediation model. The guidelines are further described in terms of a phased approach to mediation.
- Full Text:
- Date Issued: 2019
- Authors: Nordien-Lagardien, Razia
- Date: 2019
- Subjects: Mediation , Unmarried fathers -- South Africa Father and child -- South Africa Unmarried mothers -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/30462 , vital:30948
- Description: A significant change brought about by the Children’s Act 38 of 2005 (RSA, 2006), is that of the status of unmarried fathers. The parental rights of unmarried fathers have evolved in South Africa, especially since the Children’s Act 38 of 2005 (RSA, 2006) now recognises that unmarried fathers should have inherent right of contact, guardianship and care. These rights are, however, not automatic and need to be acquired through a process of mediation. While this legislation aims to facilitate the parental involvement of fathers by giving them rights as per Section 21 of the Children’s Act 38 of 2005 (RSA, 2006), the reality is that many unmarried fathers still remain challenged in this regard despite the change in their legal position as fathers. Unmarried fathers are often compelled to take the matter further through protracted court processes. Unmarried fathers face unique challenges with parental involvement after separation and they often need to negotiate their involvement with the mother after separation. Given that mediation between unmarried parents is in its infancy in South Africa, very little research has been done in this area. It was envisaged that this study would highlight the important aspects of mediation which need to be considered in order for mediation outcomes to be more successful and to enhance the co-parenting relationship. The study employed a qualitative research approach that was exploratory, descriptive and contextual in design. The research study consisted of three phases. Phase 1 employed a multiple case study design in order to develop an understanding of the experiences and perceptions of unmarried fathers and mothers, as well as mediators, regarding the parental responsibilities of unmarried fathers in addition to their experiences of mediation. The data collection process comprised in-depth semi-structured interviews with three sample groups, namely unmarried fathers, and mothers, and mediators. The data collected from the interviews were transcribed, coded and analysed by the researcher through the use of two techniques, namely: within-case analysis and cross-case synthesis. An independent coder was utilised to verify the coding and analysis process. The analysis of the data in Phase 1 revealed that the construction of the role of unmarried fathers is influenced by various factors such as cultural and religious influences; childhood experiences of fatherhood; societal constructions of the father’s role, and the perception of the legal rights of unmarried fathers. The new legislation pertaining to the responsibilities and rights of unmarried fathers, as contained in the Children’s Act 38 of 2005 (RSA, 2006), has resulted in increased parental conflict between parents after separation owing to their lack of awareness and confusion regarding the changes in legislation pertaining to the rights of unmarried fathers and the role of customary law in this regard. This has resulted in misconceptions about the legal rights of unmarried fathers, which have influenced unmarried parents’ attitudes and receptiveness to mediation. A significant barrier to father involvement emanating from the findings was relationship conflict experienced after separation, which was also identified as a significant challenge in mediation. The discussion of the themes reflected both positive and negative experiences of mediation for the study participants. While the parents derived educational and therapeutic benefits from mediation; there were also several factors such as relationship conflict, cultural barriers, influences of the extended family, and the approach and skills of the mediator, which influenced the mediation process. In Phase 2 of the study an integrative literature review and synthesis of the literature was conducted and critically appraised in terms of emergent themes and relevant research in the area of family mediation, which would inform the process of developing the descriptive guidelines for mediation with unmarried parents. The empirical findings from the study were synthesised with the findings from the integrative literature review, thus enabling conclusions to be drawn in order to generate descriptive guidelines for mediation. Phase 3 of the study describes the guidelines for mediation which emanated from the synthesis of the findings in Phase 1 and Phase 2 of the study. As part of a qualitative evaluation, the guidelines were presented to an expert panel for review, after which the guidelines were finalised. The proposed guidelines for mediation to enhance the parental involvement of unmarried fathers is based on the hybrid model of mediation, which incorporates elements from the Transformative approach, the African centred approach and the co-mediation model. The guidelines are further described in terms of a phased approach to mediation.
- Full Text:
- Date Issued: 2019
Design of metal ion-selective reagents for recovery of precious metals
- Authors: Moleko-Boyce, Pulleng
- Date: 2019
- Subjects: Bioinorganic chemistry , Metal complexes Speciation (Chemistry)
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/42510 , vital:36664
- Description: The study is divided into two sections; namely, (1) the design of rhodium(III) specific chelating ligands (tridentate bis-benzimidazole derivatives), and (2) the development of iridium(IV)-specific quaternary diammonium cations with electron donating and electron withdrawing groups. Bis-benzimidazole chelating ligands used were bis((1H-benzimidazol-2-yl)methyl)amine (NNN1), bis((1H-benzimidazol-2-yl)ethyl)amine (NNN2), bis((1H-benzimidazol-2-yl)methyl)sulfide (NSN1) and bis((1H-benzimidazol-2-yl)ethyl)sulfide (NSN2). Quaternary diammonium cations used were tetramethylbenzyl-1,10-diammonium chloride (QuatDMDAMeBnz), tetrabenzyl-1,10-diammonium chloride (QuatDMDABnz), tetratrifluoromethylbenzyl-1,10-diammonium chloride (QuatDMDACF3Bnz) and tetranitrobenzyl-1,10-diammonium chloride (QuatDMDANO2Bnz). For both studies, polyvinylbenzylchloride (PVBC) nanofibers were used as support material. The PVBC nanofibers which were functionalised with bis-benzimidazole derivatives and quaternary diammonium cations, respectively, were investigated for the selectivity for Rh(III) over Ir(III), Pt(II), Pd(II) and Ni(II), and for separation of Ir(IV) from Rh(III), respectively. The sorbent materials were characterised by FTIR, SEM, BET surface area, TGA, EDS and elemental analysis, and the results showed that the functionalization of the sorbent materials was successful.The efficiency of bis-benzimidazole derivatives and quaternary diammonium cations, respectively, were investigated in a column study under dynamic flow adsorption conditions. The adsorption kinetics and isotherms were investigated under batch conditions and fitted on pseudo-first-order and pseudo-second-order model, and Freundlich and Langmuir isotherm, respectively. It was observed that the bis-benzimidazole derivatives showed uptake of [RhCl3(H2O)3], and the loading capacities were observed in the following order; NSN1 (181.06 mg/g) > NSN2 (148.55 mg/g) > NNN1 (131.88 mg/g) > NNN2 (75.87 mg/g). The bis-benzimidazole derivatives preference for metal ions was further investigated with a multi-element solution containing Rh(III), Ir(III), Pt(II), Pd(II) and Ni(II). The bis-benzimidazole derivatives showed the following order of loading capacity: NSN1 (47.28 mg/g) > NSN2 (23.89 mg/g) > NNN1 (17.47 mg/g) > NNN2 (14.91 mg/g) for Rh(III); NSN2 (10.64 mg/g) > NNN2 (6.84 mg/g) > NSN1 (5.74 mg/g) > NNN1 (5.02 mg/g) for Ir(III); NNN2 (33.96 mg/g) > NSN1 (30.95 mg/g) > NSN2 (19.95 mg/g) > NNN1 (14.92 mg/g) for Pt(II); NNN1 (47.94 mg/g) > NNN2 (28.90 mg/g) > NSN1 (16.22 mg/g) > NSN2 (15.83 mg/g) for Pd(II). Bis-benzimidazole derivatives showed no uptake of nickel(II) under these conditions. It was observed the ligand-selectivity order for Rh(III) was similar in both single-element and multi-element studies. This order showed that the bis-benzimidazoles containing a sulfur atom showed a high preference for rhodium(III) compared to Pt(II) which had a high preference for NNN2 as well as Pd(II) which had a high preference for NNN1. Ir(III) generally had a lower preference for the ligands presumably due to its higher kinetic inertness compared with Rh(III). Column sorption of [IrCl6]2- and [RhCl5(H2O)]2- on nanofibers functionalized with diammonium cations was carried out and the loading capacities of [IrCl6]2- were obtained. [RhCl5(H2O)]2- was not adsorbed by the sorbent materials while [IrCl6]2- was loaded onto the column. The loading capacities of [IrCl6]2- with the quaternary diammonium sorbent materials increased in the order of F-QuatDMDAMeBnz (60.29 mg/g) < F-QuatDMDABnz (67.61 mg/g) < F-QuatDMDACF3Bnz (107.59 mg/g) < F-QuatDMDANO2Bnz (140.47 mg/g). The loading capacity for Ir(IV) with quaternary diammonium cationic nanofibers increased with an increase in the electron-withdrawing nature of the quaternizing group. The charge delocalizing ability of the nitrobenzyl group resulted in the best interaction of the diammonium cation with [IrCl6]2-. Batch equilibrium studies were carried out to assess the efficiency of bis-benzimidazole chelating derivatives as adsorbents using a multi-metal solution (Rh(III), Ir(III), Pt(II), Pd(II) and Ni(II)) in 0.5 M HCl. The efficiency of the quaternary diammonium cations was tested using a binary metal solution (Ir(IV) and Rh(III)) in 6 M HCl. The isothermal batch adsorption studies of a multi-metal solution with bis-benzimidazoles derivatives fitted the Langmuir isotherm model which confirmed monolayer adsorption onto a homogeneous surface. The Langmuir isotherm parameter (qe (mg/g)), using functionalized nanofibers, showed the order of NNN2 (128.21 mg/g) > NSN1 (99.01 mg/g) > NSN2 (91.74 mg/g) > NNN1 (84.03 mg/g) for Pt(II); NNN1 (66.23 mg/g) > NNN2 (5.89 mg/g) > NSN1 (1.40 mg/g) > NSN2 (0.59 mg/g) for Pd(II); NSN2 (10.64 mg/g) > NNN2 (6.84 mg/g) > NSN1 (5.74 mg/g) > NNN1 (5.02 mg/g) for Ir(III); NSN1 (140.85 mg/g) > NSN2 (109.89 mg/g) > NNN1 (104.17 mg/g) > NNN2 (91.74 mg/g) for Rh(III). The pseudo-first-order kinetics model was found to be the best fit to describe the adsorption kinetics of all metal ions onto all the sorbent materials. K1 (min-1) value in pseudo-first-order kinetics showed the same order of adsorption as observed in the Langmuir isotherms. The isothermal batch adsorption studies of [IrCl6]2- and [RhCl5(H2O)]2- with quaternary diammonium cations fitted the Freundlich isotherm model and confirmed to be effective for multiple-layered adsorption onto a heterogeneous surface. The Freundlich isotherm parameter (kf (mg/g)) using functionalized quaternary diammonium cationic nanofibers increased in the order of F-QuatDMDANO2Bnz (794.33 mg/g) > F-QuatDMDACF3Bnz (185.35 mg/g) > F-QuatDMDABnz (156.32 mg/g) > F-QuatDMDAMeBnz (112.46 mg/g) for Ir(IV) uptake. F-QuatDMDANO2Bnz resin showed the highest adsorption than that of F-QuatDMDAMeBnz, F-QuatDMDABnz and F-QuatDMDACF3Bnz and this order is similar to what was observed in column studies. The quaternary diammonium cations were shown to have the highest adsorption capacity for Ir(IV) compared with Rh(III). The adsorption of Rh(III) was also observed to increase in the order of F-QuatDMDANO2Bnz (177.83 mg/g) > F-QuatDMDACF3Bnz (40.37 mg/g) > F-QuatDMDABnz (36.98 mg/g) > F-QuatDMDAMeBnz (12.71 mg/g). The pseudo-second-order kinetic model was found to be the best fit to describe the adsorption kinetics of both metal ions onto all the sorbent materials. K2 (g.mg-1min-1) value in pseudo-second-order kinetics showed the same order of adsorption as observed in the Freundlich isotherms. The adsorption studies showed adsorption takes place via chemisorption process. This thesis presents PGMs and iridium-specific materials that could be applied in solutions of secondary PGMs sources containing rhodium, platinum and palladium with bis-benzimidazoles as well as in feed solutions from ore processing with diammonium cations for iridium recovery.
- Full Text:
- Date Issued: 2019
- Authors: Moleko-Boyce, Pulleng
- Date: 2019
- Subjects: Bioinorganic chemistry , Metal complexes Speciation (Chemistry)
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/42510 , vital:36664
- Description: The study is divided into two sections; namely, (1) the design of rhodium(III) specific chelating ligands (tridentate bis-benzimidazole derivatives), and (2) the development of iridium(IV)-specific quaternary diammonium cations with electron donating and electron withdrawing groups. Bis-benzimidazole chelating ligands used were bis((1H-benzimidazol-2-yl)methyl)amine (NNN1), bis((1H-benzimidazol-2-yl)ethyl)amine (NNN2), bis((1H-benzimidazol-2-yl)methyl)sulfide (NSN1) and bis((1H-benzimidazol-2-yl)ethyl)sulfide (NSN2). Quaternary diammonium cations used were tetramethylbenzyl-1,10-diammonium chloride (QuatDMDAMeBnz), tetrabenzyl-1,10-diammonium chloride (QuatDMDABnz), tetratrifluoromethylbenzyl-1,10-diammonium chloride (QuatDMDACF3Bnz) and tetranitrobenzyl-1,10-diammonium chloride (QuatDMDANO2Bnz). For both studies, polyvinylbenzylchloride (PVBC) nanofibers were used as support material. The PVBC nanofibers which were functionalised with bis-benzimidazole derivatives and quaternary diammonium cations, respectively, were investigated for the selectivity for Rh(III) over Ir(III), Pt(II), Pd(II) and Ni(II), and for separation of Ir(IV) from Rh(III), respectively. The sorbent materials were characterised by FTIR, SEM, BET surface area, TGA, EDS and elemental analysis, and the results showed that the functionalization of the sorbent materials was successful.The efficiency of bis-benzimidazole derivatives and quaternary diammonium cations, respectively, were investigated in a column study under dynamic flow adsorption conditions. The adsorption kinetics and isotherms were investigated under batch conditions and fitted on pseudo-first-order and pseudo-second-order model, and Freundlich and Langmuir isotherm, respectively. It was observed that the bis-benzimidazole derivatives showed uptake of [RhCl3(H2O)3], and the loading capacities were observed in the following order; NSN1 (181.06 mg/g) > NSN2 (148.55 mg/g) > NNN1 (131.88 mg/g) > NNN2 (75.87 mg/g). The bis-benzimidazole derivatives preference for metal ions was further investigated with a multi-element solution containing Rh(III), Ir(III), Pt(II), Pd(II) and Ni(II). The bis-benzimidazole derivatives showed the following order of loading capacity: NSN1 (47.28 mg/g) > NSN2 (23.89 mg/g) > NNN1 (17.47 mg/g) > NNN2 (14.91 mg/g) for Rh(III); NSN2 (10.64 mg/g) > NNN2 (6.84 mg/g) > NSN1 (5.74 mg/g) > NNN1 (5.02 mg/g) for Ir(III); NNN2 (33.96 mg/g) > NSN1 (30.95 mg/g) > NSN2 (19.95 mg/g) > NNN1 (14.92 mg/g) for Pt(II); NNN1 (47.94 mg/g) > NNN2 (28.90 mg/g) > NSN1 (16.22 mg/g) > NSN2 (15.83 mg/g) for Pd(II). Bis-benzimidazole derivatives showed no uptake of nickel(II) under these conditions. It was observed the ligand-selectivity order for Rh(III) was similar in both single-element and multi-element studies. This order showed that the bis-benzimidazoles containing a sulfur atom showed a high preference for rhodium(III) compared to Pt(II) which had a high preference for NNN2 as well as Pd(II) which had a high preference for NNN1. Ir(III) generally had a lower preference for the ligands presumably due to its higher kinetic inertness compared with Rh(III). Column sorption of [IrCl6]2- and [RhCl5(H2O)]2- on nanofibers functionalized with diammonium cations was carried out and the loading capacities of [IrCl6]2- were obtained. [RhCl5(H2O)]2- was not adsorbed by the sorbent materials while [IrCl6]2- was loaded onto the column. The loading capacities of [IrCl6]2- with the quaternary diammonium sorbent materials increased in the order of F-QuatDMDAMeBnz (60.29 mg/g) < F-QuatDMDABnz (67.61 mg/g) < F-QuatDMDACF3Bnz (107.59 mg/g) < F-QuatDMDANO2Bnz (140.47 mg/g). The loading capacity for Ir(IV) with quaternary diammonium cationic nanofibers increased with an increase in the electron-withdrawing nature of the quaternizing group. The charge delocalizing ability of the nitrobenzyl group resulted in the best interaction of the diammonium cation with [IrCl6]2-. Batch equilibrium studies were carried out to assess the efficiency of bis-benzimidazole chelating derivatives as adsorbents using a multi-metal solution (Rh(III), Ir(III), Pt(II), Pd(II) and Ni(II)) in 0.5 M HCl. The efficiency of the quaternary diammonium cations was tested using a binary metal solution (Ir(IV) and Rh(III)) in 6 M HCl. The isothermal batch adsorption studies of a multi-metal solution with bis-benzimidazoles derivatives fitted the Langmuir isotherm model which confirmed monolayer adsorption onto a homogeneous surface. The Langmuir isotherm parameter (qe (mg/g)), using functionalized nanofibers, showed the order of NNN2 (128.21 mg/g) > NSN1 (99.01 mg/g) > NSN2 (91.74 mg/g) > NNN1 (84.03 mg/g) for Pt(II); NNN1 (66.23 mg/g) > NNN2 (5.89 mg/g) > NSN1 (1.40 mg/g) > NSN2 (0.59 mg/g) for Pd(II); NSN2 (10.64 mg/g) > NNN2 (6.84 mg/g) > NSN1 (5.74 mg/g) > NNN1 (5.02 mg/g) for Ir(III); NSN1 (140.85 mg/g) > NSN2 (109.89 mg/g) > NNN1 (104.17 mg/g) > NNN2 (91.74 mg/g) for Rh(III). The pseudo-first-order kinetics model was found to be the best fit to describe the adsorption kinetics of all metal ions onto all the sorbent materials. K1 (min-1) value in pseudo-first-order kinetics showed the same order of adsorption as observed in the Langmuir isotherms. The isothermal batch adsorption studies of [IrCl6]2- and [RhCl5(H2O)]2- with quaternary diammonium cations fitted the Freundlich isotherm model and confirmed to be effective for multiple-layered adsorption onto a heterogeneous surface. The Freundlich isotherm parameter (kf (mg/g)) using functionalized quaternary diammonium cationic nanofibers increased in the order of F-QuatDMDANO2Bnz (794.33 mg/g) > F-QuatDMDACF3Bnz (185.35 mg/g) > F-QuatDMDABnz (156.32 mg/g) > F-QuatDMDAMeBnz (112.46 mg/g) for Ir(IV) uptake. F-QuatDMDANO2Bnz resin showed the highest adsorption than that of F-QuatDMDAMeBnz, F-QuatDMDABnz and F-QuatDMDACF3Bnz and this order is similar to what was observed in column studies. The quaternary diammonium cations were shown to have the highest adsorption capacity for Ir(IV) compared with Rh(III). The adsorption of Rh(III) was also observed to increase in the order of F-QuatDMDANO2Bnz (177.83 mg/g) > F-QuatDMDACF3Bnz (40.37 mg/g) > F-QuatDMDABnz (36.98 mg/g) > F-QuatDMDAMeBnz (12.71 mg/g). The pseudo-second-order kinetic model was found to be the best fit to describe the adsorption kinetics of both metal ions onto all the sorbent materials. K2 (g.mg-1min-1) value in pseudo-second-order kinetics showed the same order of adsorption as observed in the Freundlich isotherms. The adsorption studies showed adsorption takes place via chemisorption process. This thesis presents PGMs and iridium-specific materials that could be applied in solutions of secondary PGMs sources containing rhodium, platinum and palladium with bis-benzimidazoles as well as in feed solutions from ore processing with diammonium cations for iridium recovery.
- Full Text:
- Date Issued: 2019
Development of spunlaced nonwoven filters from PAN, PPS and PI fibres for industrial use
- Authors: Maduna, Lebo
- Date: 2019
- Subjects: Textile fibers -- Mechanical properties , Nonwoven fabrics --Technological innovations Textile fibers, Synthetic -- Mechanical properties
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/32610 , vital:32266
- Description: The aim of this work was to produce filter fabrics suitable for high temperature and other conditions encountered in coal power plants using the spunlacing manufacturing technique. Polyacrylonitrile (PAN), polyphenylene sulfide (PPS) and polyimide (PI) fibres being combined suitable for this purpose, each at three aerial density of (440, 500 and 560 g/m2) and each at three water jet pressures of (60, 80 and 90 bars) were produced. The effect of changing these on the fabric air permeability, tensile strength and filtration properties were investigated and optimized. For this purpose, the Box-Behnken experimental design (BBD) was considered the best and therefore used. The PPS/PI fabrics were found to consistently have the highest air permeability, tensile strength and filtration performance, followed by the PPS fabrics and the PAN fabrics. As could be expected, an increase in area weight and water jet pressure generally resulted in a decrease in air permeability irrespective of the fabric types, this being due to the increased number of fibres and therefore greater fibre surface area and entanglement respectively. For fabric tensile strength, the effects of varying fabric area weight and water jet pressure were not so straight forward. For cross direction (CD) an increase in water jet pressure resulted in an increase tensile strength whereas in the machine direction (MD) there was a decrease when the water jet pressure was increased. The filtration efficiency and dust holding capacity of the fabrics were found to be around 96% and 211g/m2, respectively, with the exception of the PPS (500 g/m2 80 bar) fabrics. Increasing the amount of dust being fed to the fabric during each loading cycle, it caused an increase in pressure drop, as the fabrics became increasingly clogged forming a cake layer.
- Full Text:
- Date Issued: 2019
- Authors: Maduna, Lebo
- Date: 2019
- Subjects: Textile fibers -- Mechanical properties , Nonwoven fabrics --Technological innovations Textile fibers, Synthetic -- Mechanical properties
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/32610 , vital:32266
- Description: The aim of this work was to produce filter fabrics suitable for high temperature and other conditions encountered in coal power plants using the spunlacing manufacturing technique. Polyacrylonitrile (PAN), polyphenylene sulfide (PPS) and polyimide (PI) fibres being combined suitable for this purpose, each at three aerial density of (440, 500 and 560 g/m2) and each at three water jet pressures of (60, 80 and 90 bars) were produced. The effect of changing these on the fabric air permeability, tensile strength and filtration properties were investigated and optimized. For this purpose, the Box-Behnken experimental design (BBD) was considered the best and therefore used. The PPS/PI fabrics were found to consistently have the highest air permeability, tensile strength and filtration performance, followed by the PPS fabrics and the PAN fabrics. As could be expected, an increase in area weight and water jet pressure generally resulted in a decrease in air permeability irrespective of the fabric types, this being due to the increased number of fibres and therefore greater fibre surface area and entanglement respectively. For fabric tensile strength, the effects of varying fabric area weight and water jet pressure were not so straight forward. For cross direction (CD) an increase in water jet pressure resulted in an increase tensile strength whereas in the machine direction (MD) there was a decrease when the water jet pressure was increased. The filtration efficiency and dust holding capacity of the fabrics were found to be around 96% and 211g/m2, respectively, with the exception of the PPS (500 g/m2 80 bar) fabrics. Increasing the amount of dust being fed to the fabric during each loading cycle, it caused an increase in pressure drop, as the fabrics became increasingly clogged forming a cake layer.
- Full Text:
- Date Issued: 2019
Effects of 99-year leases on newly resettled farmers’ farm improvement, productivity and empowerment in Zimbabwe, 2007 to 2013
- Authors: Makaye, Peter
- Date: 2019
- Subjects: Land reform - -Zimbabwe , Land tenure -- Zimbabwe Farmers -- Zimbabwe Sustainable development -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/40812 , vital:36239
- Description: This study seeks to interrogate the effects of 99-year leases on newly resettled farmers, with focus on Zimbabwe’s Fast Track Land Reform programme, shifting from its causes and processes to its variegated outcomes., The focus was on how the leasehold system has impinged on three variables: farm improvement, productivity, and empowerment. Quantitative data was collected from 92 newly resettled farmers randomly selected from three different farming regions in Zimbabwe: Region 2, an agriculturally well-endowed area concentrating on crop production, Region 4, an arid and hot region concentrating on livestock, and Region 5, specialising in sugar cane production under irrigation. To corroborate the survey findings, follow-up interviews and focus group discussions (FGDs) were carried out in these regions. Interviews with purposively sampled experts in agriculture in Zimbabwe were also conducted. Data are presented in charts and graphs as well as detailed descriptions. The study found that the 99-year leases influenced the fortunes of the farmers in different ways. In some areas, depending on the crop grown, the 99-year leases were accepted as a basis for a loan. In other instances, the leases have not been accepted as collateral and this has constrained the farmers’ ability to optimally utilise their farms optimally. Despite a general sense of insecurity, the farmers have shown a willingness to re-invest in the farms., Many improvements such as new accommodation for employees, the erection of fire guards, and the development of water sources are being made on the farms, all pointing to a desire for sustained utilisation of the A2 farms. The researcher proposes that serious effort has to be made towards making the 99-year leases acceptable as collateral for loans because otherwise, in the context of general undercapitalisation among the farmers, their ability to make the medium-scale farms optimally contribute to national accumulation will remain constrained. The form of tenure is related to the empowerment of the farmers, both materially and socially. This is in turn related to the sustainable use of the land and hence to sustainable development in Zimbabwe.
- Full Text:
- Date Issued: 2019
- Authors: Makaye, Peter
- Date: 2019
- Subjects: Land reform - -Zimbabwe , Land tenure -- Zimbabwe Farmers -- Zimbabwe Sustainable development -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/40812 , vital:36239
- Description: This study seeks to interrogate the effects of 99-year leases on newly resettled farmers, with focus on Zimbabwe’s Fast Track Land Reform programme, shifting from its causes and processes to its variegated outcomes., The focus was on how the leasehold system has impinged on three variables: farm improvement, productivity, and empowerment. Quantitative data was collected from 92 newly resettled farmers randomly selected from three different farming regions in Zimbabwe: Region 2, an agriculturally well-endowed area concentrating on crop production, Region 4, an arid and hot region concentrating on livestock, and Region 5, specialising in sugar cane production under irrigation. To corroborate the survey findings, follow-up interviews and focus group discussions (FGDs) were carried out in these regions. Interviews with purposively sampled experts in agriculture in Zimbabwe were also conducted. Data are presented in charts and graphs as well as detailed descriptions. The study found that the 99-year leases influenced the fortunes of the farmers in different ways. In some areas, depending on the crop grown, the 99-year leases were accepted as a basis for a loan. In other instances, the leases have not been accepted as collateral and this has constrained the farmers’ ability to optimally utilise their farms optimally. Despite a general sense of insecurity, the farmers have shown a willingness to re-invest in the farms., Many improvements such as new accommodation for employees, the erection of fire guards, and the development of water sources are being made on the farms, all pointing to a desire for sustained utilisation of the A2 farms. The researcher proposes that serious effort has to be made towards making the 99-year leases acceptable as collateral for loans because otherwise, in the context of general undercapitalisation among the farmers, their ability to make the medium-scale farms optimally contribute to national accumulation will remain constrained. The form of tenure is related to the empowerment of the farmers, both materially and socially. This is in turn related to the sustainable use of the land and hence to sustainable development in Zimbabwe.
- Full Text:
- Date Issued: 2019
Examining educators’ strategies for promoting science learning and science literacy among grade 9 learners in a South African Rural Education District
- Authors: Mtsi, Nomxolisi
- Date: 2019
- Subjects: Science -- Study and teaching (Elementary) Children's literature in science education
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/16150 , vital:40673
- Description: Science learning and Science Literacy (SL) play a crucial role in preparing learners to participate in the country’s economy with the relevant knowledge, higher order thinking and analytical reasoning to solve day-to-day problems. The purpose of this research was to examine educators’ strategies for promoting science learning and SL among grade 9 learners in a rural education district in South Africa’s Eastern Cape Province. Learning of science and promotion of SL complement each other and therefore science educators’ strategies are pertinent. The study used pragmatic paradigm and the mixed method approach and was informed by cognitive and social constructivism as theoretical frameworks. For data collection, the study used convenience sampling based on the proximity and comparative ease of the researcher to reach the rural schools to select 30 out of 67 schools spread over six out of the eight circuits in the selected education district. On the other hand, purposive sampling was used for the selection of learners by their educators based on academic performance, top, average and below average achievers. Since each school had only one grade 9 science educator, 30 grade 9 science educators from the selected 30 schools formed the sample for quantitative data. Out of these 30, 10 educators who volunteered first for interviews and gave permission for being observed in their classrooms were selected for qualitative data collection. Three learners in each of the 10 schools from which the educators for qualitative data collection were selected, constituted the learners’ sample (30 learners). While data were collected through questionnaires, interviews and observations from educators, data from learners were collected through focus group (FG) interviews. The questionnaire was structured in order to gather educators’ biographical data as well as information on educators’ strategies to promote science learning and SL. The interview schedule was similar to the questionnaire but biographical data were excluded. Observations focused on educators’ strategies for science learning, SL and assessments. The data from the questionnaire were descriptively analysed and the qualitative and transcribed observation data were thematically analysed. Final conclusions were drawn based on the triangulated data. Major findings showed that the strategies which the educators employed in the descending order of use were: Investigation at 97percent; Discussion, Presentation and Project, each at 93percent; Problem solving at 90percent; Demonstration and Question-Answer, each at 87percent; Case study and Brainstorming, each at 77percent; Role-play at 63percent; Lecture at 57percent; Modelling at 47percent, Inquiry at 27percent and Simulation at 23percent. Findings also revealed the strengths and weaknesses of the strategies used by educators. Some of the strengths were: promotion of interactive learning; stimulation of research skills; enhancement of critical thinking and development of confidence through participation. Some of the weaknesses were: learners’ tendency to rely on others; lack of resources hindering learning and promotion of plagiarism. The study recommends that all stakeholders must work together to achieve good quality education. District and Provincial officers ought to track and monitor the science curriculum implementation. Subject specialists, educator subject committees and cluster leaders must also be active in strategic planning for enhancing SL in schools by putting forward their inputs and adopting consensus-based ones. A framework for driving science content with pedagogical content knowledge and practicals-driven strategy for enhancing science content knowledge is proposed.
- Full Text:
- Date Issued: 2019
- Authors: Mtsi, Nomxolisi
- Date: 2019
- Subjects: Science -- Study and teaching (Elementary) Children's literature in science education
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/16150 , vital:40673
- Description: Science learning and Science Literacy (SL) play a crucial role in preparing learners to participate in the country’s economy with the relevant knowledge, higher order thinking and analytical reasoning to solve day-to-day problems. The purpose of this research was to examine educators’ strategies for promoting science learning and SL among grade 9 learners in a rural education district in South Africa’s Eastern Cape Province. Learning of science and promotion of SL complement each other and therefore science educators’ strategies are pertinent. The study used pragmatic paradigm and the mixed method approach and was informed by cognitive and social constructivism as theoretical frameworks. For data collection, the study used convenience sampling based on the proximity and comparative ease of the researcher to reach the rural schools to select 30 out of 67 schools spread over six out of the eight circuits in the selected education district. On the other hand, purposive sampling was used for the selection of learners by their educators based on academic performance, top, average and below average achievers. Since each school had only one grade 9 science educator, 30 grade 9 science educators from the selected 30 schools formed the sample for quantitative data. Out of these 30, 10 educators who volunteered first for interviews and gave permission for being observed in their classrooms were selected for qualitative data collection. Three learners in each of the 10 schools from which the educators for qualitative data collection were selected, constituted the learners’ sample (30 learners). While data were collected through questionnaires, interviews and observations from educators, data from learners were collected through focus group (FG) interviews. The questionnaire was structured in order to gather educators’ biographical data as well as information on educators’ strategies to promote science learning and SL. The interview schedule was similar to the questionnaire but biographical data were excluded. Observations focused on educators’ strategies for science learning, SL and assessments. The data from the questionnaire were descriptively analysed and the qualitative and transcribed observation data were thematically analysed. Final conclusions were drawn based on the triangulated data. Major findings showed that the strategies which the educators employed in the descending order of use were: Investigation at 97percent; Discussion, Presentation and Project, each at 93percent; Problem solving at 90percent; Demonstration and Question-Answer, each at 87percent; Case study and Brainstorming, each at 77percent; Role-play at 63percent; Lecture at 57percent; Modelling at 47percent, Inquiry at 27percent and Simulation at 23percent. Findings also revealed the strengths and weaknesses of the strategies used by educators. Some of the strengths were: promotion of interactive learning; stimulation of research skills; enhancement of critical thinking and development of confidence through participation. Some of the weaknesses were: learners’ tendency to rely on others; lack of resources hindering learning and promotion of plagiarism. The study recommends that all stakeholders must work together to achieve good quality education. District and Provincial officers ought to track and monitor the science curriculum implementation. Subject specialists, educator subject committees and cluster leaders must also be active in strategic planning for enhancing SL in schools by putting forward their inputs and adopting consensus-based ones. A framework for driving science content with pedagogical content knowledge and practicals-driven strategy for enhancing science content knowledge is proposed.
- Full Text:
- Date Issued: 2019
Examining the teaching of natural sciences concepts to English second language speakers in selected primary schools in the East London Education District
- Authors: Kumanda, Nomaroma
- Date: 2019
- Subjects: Science -- Study and teaching
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/15925 , vital:40564
- Description: The study sought to examine the teaching of Natural Sciences (NS) concepts to English second language speakers in selected primary schools. Grade 7 was chosen for the investigation as it precedes the last class at primary school. The researcher investigated the teaching and learning of Natural sciences concepts. A mixed method design was used. The research questions focused on the teaching of NS, learner-centred strategies used, challenges encountered, strategies employed by teachers when teaching NS, and the implications for science education.The purpose was to examine the teaching of Natural Sciences concepts to English second language speakers in selected primary schools in the East London Education District. Data were collected from grade 7 teachers and learners in selected township schools in East London, by means of semi-structured interviews, questionnaires and focus groups. Semi-structured questionnaires were administered to teachers and learners, individual interviews were conducted with NS head of department, focus group and interviews were held with grade 7 NS learners. Quantitative and qualitative data were independently analysed and merged at the interpretation stage for triangulation of results. The questions were grouped according to their themes. The researcher’s findings revealed that teachers linked the teaching of NS concepts by showing the teaching skills. Teachers used code-switching for learners to understand the scientific concepts for positive attitude to improve the learner performance. Teachers experienced problems using English as a Language of Learning and Teaching (LoLT) while teaching NS concepts, teachers’ understanding of NS influenced their ability to implement of transformational curriculum, but learners did not benefit much when learning science in English Language and those policies were designed by the Department of Education without teacher involvement. The study concluded by noting that It emerged that teachers and learners experienced difficulties in teaching and learning of the NS concepts.
- Full Text:
- Date Issued: 2019
- Authors: Kumanda, Nomaroma
- Date: 2019
- Subjects: Science -- Study and teaching
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/15925 , vital:40564
- Description: The study sought to examine the teaching of Natural Sciences (NS) concepts to English second language speakers in selected primary schools. Grade 7 was chosen for the investigation as it precedes the last class at primary school. The researcher investigated the teaching and learning of Natural sciences concepts. A mixed method design was used. The research questions focused on the teaching of NS, learner-centred strategies used, challenges encountered, strategies employed by teachers when teaching NS, and the implications for science education.The purpose was to examine the teaching of Natural Sciences concepts to English second language speakers in selected primary schools in the East London Education District. Data were collected from grade 7 teachers and learners in selected township schools in East London, by means of semi-structured interviews, questionnaires and focus groups. Semi-structured questionnaires were administered to teachers and learners, individual interviews were conducted with NS head of department, focus group and interviews were held with grade 7 NS learners. Quantitative and qualitative data were independently analysed and merged at the interpretation stage for triangulation of results. The questions were grouped according to their themes. The researcher’s findings revealed that teachers linked the teaching of NS concepts by showing the teaching skills. Teachers used code-switching for learners to understand the scientific concepts for positive attitude to improve the learner performance. Teachers experienced problems using English as a Language of Learning and Teaching (LoLT) while teaching NS concepts, teachers’ understanding of NS influenced their ability to implement of transformational curriculum, but learners did not benefit much when learning science in English Language and those policies were designed by the Department of Education without teacher involvement. The study concluded by noting that It emerged that teachers and learners experienced difficulties in teaching and learning of the NS concepts.
- Full Text:
- Date Issued: 2019
HIV-related stigma in rural areas: a case of citrus farm workers based in Addo community in Eastern Cape
- Authors: Mazorodze, Tasara
- Date: 2019
- Subjects: Stigma (Social psychology) -- South Africa -- Eastern Cape , Discrimination -- Psychology HIV infections -- Psychology AIDS (Disease) -- Psychology
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/41526 , vital:36501
- Description: While South Africa has recently joined the rest of the world in the race to achieve an AIDS free generation by the year of 2030, little has been done to develop the scientific interventions that address HIV-related stigma, which is one of the major barriers to the fight against HIV. To the researcher’s knowledge, this is the first study in the South African context that seeks to assess the forms of HIV- related stigma in a local context and in a rural area in particular, where HIV related stigma research and interventions remains scant. This study acknowledges the dynamic, unique, multidimensional and sensitive nature of HIV-related stigma and, therefore, an explanatory mixed approach enabled the researcher to provide a comprehensive assessment of HIV-related stigma amongst the citrus farm workers who are based in Addo, Eastern Cape. Quantitative data was collected from 200 participants across five farms, whereas 50 employees across the 5 farms were also selected to take part in the focus group discussions. An assessment of the reliability and validity of local HIV-related stigma scales (Kalichman et al., 2005 personal stigma scale-English, isiXhosa and Afrikaans version and Visser et al. 2008 personal and attributed stigma scale-English version) and the UNAIDS (2012) HIV knowledge scale was conducted. The assessment showed that the reliability of these scales of measurement tend to vary according to context. In this study, the Kalichman et al., (2005) personal stigma scale (English version) scored a weaker reliability score (alpha=0.58). Thus, as the scale is not reliable for the rural context, it was not considered. Furthermore, quantitative findings show that citrus farm workers are characterised by lack of/ little knowledge about HIV, which results in the stigmatisation of people who are HIV positive in the form of symbolic, instrumental, personal and attributed stigma, as well as a fear of HIV disclosure. Findings also revealed that participants who display a high personal stigma score are likely to display a high attributed stigma score (r=0.47, p<0.00). This confirm the assumption of social identity theory that people tend to use stigma as a ‘protective function’ to protect their identity by labelling other people as ‘’deviant’ or ‘stigmatising’. This finding is particularly relevant in that it reveals that, while many people are aware that stigmatising people with HIV is not morally acceptable, they rather attribute stigmatising attitudes to their communities. Thus future studies need to consider emphasising the assessment of attributed stigma in a rural context. Quantitative findings also revealed that the effect of the following demographic variables, namely race (F=20.1, p=0.00), marital status (F=3.58, p=0.00), religion (F=7.17, p=0.03) and education (F=2.63, p=0.03) on HIV-related stigma was statistically significant. This provides proof that HIV-related interventions that were developed for the Addo community need to consider the above-mentioned demographics variables. The qualitative findings provided an in-depth analysis of the key quantitative findings. A lack of knowledge about HIV among participants was further confirmed by the following themes that were common during focus group discussions: misconceptions about HIV transmission and prevention; false beliefs that healthy looking people cannot have HIV; HIV symptoms are clearly visible; and HIV can be transmitted through contact with people who are HIV positive. Possible causes of HIV-related stigma as revealed by the qualitative findings include; fear of death; the belief that HIV is a punishment for bad behaviour; and the fear of being isolated and rejected. The qualitative approach revealed other forms of HIV-related stigma that were not common in the quantitative studynamely; healthcare, employment and verbal stigma. The focus group discussions revealed the major reasons why a large number of the farm works may be reluctant to disclose their status, namely fear of the unknown and attributed stigma. The study concluded by offering recommendations for the designing and tailoring of HIV-related interventions in the rural context and in the citrus sector in particular.
- Full Text:
- Date Issued: 2019
- Authors: Mazorodze, Tasara
- Date: 2019
- Subjects: Stigma (Social psychology) -- South Africa -- Eastern Cape , Discrimination -- Psychology HIV infections -- Psychology AIDS (Disease) -- Psychology
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/41526 , vital:36501
- Description: While South Africa has recently joined the rest of the world in the race to achieve an AIDS free generation by the year of 2030, little has been done to develop the scientific interventions that address HIV-related stigma, which is one of the major barriers to the fight against HIV. To the researcher’s knowledge, this is the first study in the South African context that seeks to assess the forms of HIV- related stigma in a local context and in a rural area in particular, where HIV related stigma research and interventions remains scant. This study acknowledges the dynamic, unique, multidimensional and sensitive nature of HIV-related stigma and, therefore, an explanatory mixed approach enabled the researcher to provide a comprehensive assessment of HIV-related stigma amongst the citrus farm workers who are based in Addo, Eastern Cape. Quantitative data was collected from 200 participants across five farms, whereas 50 employees across the 5 farms were also selected to take part in the focus group discussions. An assessment of the reliability and validity of local HIV-related stigma scales (Kalichman et al., 2005 personal stigma scale-English, isiXhosa and Afrikaans version and Visser et al. 2008 personal and attributed stigma scale-English version) and the UNAIDS (2012) HIV knowledge scale was conducted. The assessment showed that the reliability of these scales of measurement tend to vary according to context. In this study, the Kalichman et al., (2005) personal stigma scale (English version) scored a weaker reliability score (alpha=0.58). Thus, as the scale is not reliable for the rural context, it was not considered. Furthermore, quantitative findings show that citrus farm workers are characterised by lack of/ little knowledge about HIV, which results in the stigmatisation of people who are HIV positive in the form of symbolic, instrumental, personal and attributed stigma, as well as a fear of HIV disclosure. Findings also revealed that participants who display a high personal stigma score are likely to display a high attributed stigma score (r=0.47, p<0.00). This confirm the assumption of social identity theory that people tend to use stigma as a ‘protective function’ to protect their identity by labelling other people as ‘’deviant’ or ‘stigmatising’. This finding is particularly relevant in that it reveals that, while many people are aware that stigmatising people with HIV is not morally acceptable, they rather attribute stigmatising attitudes to their communities. Thus future studies need to consider emphasising the assessment of attributed stigma in a rural context. Quantitative findings also revealed that the effect of the following demographic variables, namely race (F=20.1, p=0.00), marital status (F=3.58, p=0.00), religion (F=7.17, p=0.03) and education (F=2.63, p=0.03) on HIV-related stigma was statistically significant. This provides proof that HIV-related interventions that were developed for the Addo community need to consider the above-mentioned demographics variables. The qualitative findings provided an in-depth analysis of the key quantitative findings. A lack of knowledge about HIV among participants was further confirmed by the following themes that were common during focus group discussions: misconceptions about HIV transmission and prevention; false beliefs that healthy looking people cannot have HIV; HIV symptoms are clearly visible; and HIV can be transmitted through contact with people who are HIV positive. Possible causes of HIV-related stigma as revealed by the qualitative findings include; fear of death; the belief that HIV is a punishment for bad behaviour; and the fear of being isolated and rejected. The qualitative approach revealed other forms of HIV-related stigma that were not common in the quantitative studynamely; healthcare, employment and verbal stigma. The focus group discussions revealed the major reasons why a large number of the farm works may be reluctant to disclose their status, namely fear of the unknown and attributed stigma. The study concluded by offering recommendations for the designing and tailoring of HIV-related interventions in the rural context and in the citrus sector in particular.
- Full Text:
- Date Issued: 2019
Implementation of school-based assessment in high schools, Mpumalanga Province, South Africa : implications for teaching and learning
- Authors: Chipfiko, Jack
- Date: 2019
- Subjects: High schools -- Examinations Educational tests and measurements
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/15892 , vital:40549
- Description: The purpose of any education system is to deliver a quality educational product. Various forms of assessment are used to ensure the suitability of the product and inform decisions. In South Africa, School-Based Assessment(SBA) is one of the tools used to assess the content competences, skills, values and attitudes; to provide learners, parents and teachers with results that are a meaningful indication of what the learners know, understand and can do at the time of assessment (DBE, 2012). Surprisingly, on a yearly basis, Umalusi reports reveal that SBA marks are rejected resulting in the learners being resulted on mostly the year end examination. The purpose of this study was to examine the implementation of SBA with a view to unearth the factors contributing to the perennial rejection of SBA marks, resulting in learners from some schools being unfairly assessed. To explore the research problem, a mixed methods study, employing a concurrent triangulation design, was employed. Total Quality Management theory was the theoretical framework anchoring this study. Sub research questions to interrogate the research problem focused on examining the roles of the teachers, learners and parents in the implementation of SBA; assessing the structures in place to support the implementation of SBA; examining how teachers, learners and parents play complementary roles in the implementation of SBA; and identifying strategies to enhance the implementation of SBA in South African (SA) high schools. Data were collected using Questionnaires, interviews and focus group discussions with purposively selected samples of teachers, learners and SGB chairpersons from high schools in White River Circuit in Mpumalanga Province in South Africa. The use of mixed methods produced quantitative and qualitative data which were independently analysed and merged during interpretation. Findings revealed that: participants and respondents confirmed the various roles of SBA in teaching and learning; structures were in place to support the implementation of SBA in high schools; complementarity of roles were sporadic in the implementation of SBA in high schools; and various strategies were employed to enhance the implementation of SBA in high schools. Implications for teaching and learning focused on realigning the implementation processes in the production of a quality educational product, and maximising its benefits to teachers, learners and parents.
- Full Text:
- Date Issued: 2019
- Authors: Chipfiko, Jack
- Date: 2019
- Subjects: High schools -- Examinations Educational tests and measurements
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/15892 , vital:40549
- Description: The purpose of any education system is to deliver a quality educational product. Various forms of assessment are used to ensure the suitability of the product and inform decisions. In South Africa, School-Based Assessment(SBA) is one of the tools used to assess the content competences, skills, values and attitudes; to provide learners, parents and teachers with results that are a meaningful indication of what the learners know, understand and can do at the time of assessment (DBE, 2012). Surprisingly, on a yearly basis, Umalusi reports reveal that SBA marks are rejected resulting in the learners being resulted on mostly the year end examination. The purpose of this study was to examine the implementation of SBA with a view to unearth the factors contributing to the perennial rejection of SBA marks, resulting in learners from some schools being unfairly assessed. To explore the research problem, a mixed methods study, employing a concurrent triangulation design, was employed. Total Quality Management theory was the theoretical framework anchoring this study. Sub research questions to interrogate the research problem focused on examining the roles of the teachers, learners and parents in the implementation of SBA; assessing the structures in place to support the implementation of SBA; examining how teachers, learners and parents play complementary roles in the implementation of SBA; and identifying strategies to enhance the implementation of SBA in South African (SA) high schools. Data were collected using Questionnaires, interviews and focus group discussions with purposively selected samples of teachers, learners and SGB chairpersons from high schools in White River Circuit in Mpumalanga Province in South Africa. The use of mixed methods produced quantitative and qualitative data which were independently analysed and merged during interpretation. Findings revealed that: participants and respondents confirmed the various roles of SBA in teaching and learning; structures were in place to support the implementation of SBA in high schools; complementarity of roles were sporadic in the implementation of SBA in high schools; and various strategies were employed to enhance the implementation of SBA in high schools. Implications for teaching and learning focused on realigning the implementation processes in the production of a quality educational product, and maximising its benefits to teachers, learners and parents.
- Full Text:
- Date Issued: 2019
In search of identity: an anthropological study on the experiences of Rastafarians in contemporary Malawi
- Authors: Maganga, Stewart Martin
- Date: 2019
- Subjects: Malawi -- Religious life and customs , Rastafari movement Identity (Philosophical concept)
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/42536 , vital:36666
- Description: Prior to 1994, religious freedoms were largely restricted because the constitution at the time vested its powers in the president who was at the time was Dr. Hastings Kamuzu Banda. Banda, who ruled Malawi for thirty years, sought to present Malawi to the outside world as a Christian nation. This was purposefully done by ignoring the existence of other religious faiths in the country of which Rastafari was one. Although the Rastafari movement was in existence during Banda’s presidency, most Rastas found it difficult to practice their religious beliefs freely. Because of this, it was found that throughout the three decades Banda was in power, the Rastafari movement in Malawi was virtually underground. This further gave the public impression to the public at the time that Rastas were non-existent in the country. It was only after the general elections of 1994 that Malawians became aware of the existence of the Rastafari movement in the country. With that said, there remains a paucity of written information on the Rastafari movement in Malawi, that is before and after the 1994 general election. To be able to establish why the Rastafari movement continues to grow in Malawi, this thesis began by addressing the question of why a certain group of individuals would seek becoming to Rastas in Malawi including its impact on their lives including relationships with both friends and family members. For the many that embraced Rastafari, the intention was to embrace a spiritual identity that was separate to that of their parents. Most raised the concern that the religions that they were previously affiliated did not allow them the freedom to explore their spirituality. This further raises the question regarding the link between established religions and spirituality. In as much as Rastafari has provided the individuals in this study a sense of meaning and identity in their lives, they have had to contend with facing confrontation with friends and family members. This thesis also explored the experiences that come with being a Rasta in Malawi. Amongst the issues that are of concern to the Rasta community is that for the many Rasta children that attend public schools, most are denied their right to attend classes with dreadlocks. Most Rastas had hoped that with the advent of democracy in Malawi, their fundamental rights would be recognised and protected under the constitution. What this thesis has demonstrated that despite the existence of democracy in Malawi, it did ultimately result in a society that would be open to diversity. What this study has demonstrated is that Malawi continues to remain a highly conservative society. This is further illustrated in the way Malawian Rastas have had to contend with being denied employment opportunities including their fundamental right to smoke chamba (marijuana) freely. This thesis set out to argue that the democracy brought about by the elections of 1994 did not necessarily result in the improved conditions of minority religious groups like Rastafarians. This is despite the current constitution allowing for religious freedom. Despite this, the thesis further set out to show that the Rastafari movement does have vital role in the current dispensation. The issues that make the Rastafari movement pertinent in present-day Malawi include issues of corruption and neo-colonialism. This thesis concluded that more must be done to improve the conditions of Rastas in Malawi. Some of recommendations that were raised in this study included reviewing the current policy regarding the length of hair that one wears to school as it relates to one’s religious beliefs. The other recommendation that was raised in this study includes amending the Religious and Moral Education (RME) school curriculum in order that it becomes inclusive of other religious faiths that are existing in the country. In addition, the current legislation regarding the possession of chamba must be amended to accommodate for religious groups such as Rastas who use it for religious purposes.
- Full Text:
- Date Issued: 2019
- Authors: Maganga, Stewart Martin
- Date: 2019
- Subjects: Malawi -- Religious life and customs , Rastafari movement Identity (Philosophical concept)
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/42536 , vital:36666
- Description: Prior to 1994, religious freedoms were largely restricted because the constitution at the time vested its powers in the president who was at the time was Dr. Hastings Kamuzu Banda. Banda, who ruled Malawi for thirty years, sought to present Malawi to the outside world as a Christian nation. This was purposefully done by ignoring the existence of other religious faiths in the country of which Rastafari was one. Although the Rastafari movement was in existence during Banda’s presidency, most Rastas found it difficult to practice their religious beliefs freely. Because of this, it was found that throughout the three decades Banda was in power, the Rastafari movement in Malawi was virtually underground. This further gave the public impression to the public at the time that Rastas were non-existent in the country. It was only after the general elections of 1994 that Malawians became aware of the existence of the Rastafari movement in the country. With that said, there remains a paucity of written information on the Rastafari movement in Malawi, that is before and after the 1994 general election. To be able to establish why the Rastafari movement continues to grow in Malawi, this thesis began by addressing the question of why a certain group of individuals would seek becoming to Rastas in Malawi including its impact on their lives including relationships with both friends and family members. For the many that embraced Rastafari, the intention was to embrace a spiritual identity that was separate to that of their parents. Most raised the concern that the religions that they were previously affiliated did not allow them the freedom to explore their spirituality. This further raises the question regarding the link between established religions and spirituality. In as much as Rastafari has provided the individuals in this study a sense of meaning and identity in their lives, they have had to contend with facing confrontation with friends and family members. This thesis also explored the experiences that come with being a Rasta in Malawi. Amongst the issues that are of concern to the Rasta community is that for the many Rasta children that attend public schools, most are denied their right to attend classes with dreadlocks. Most Rastas had hoped that with the advent of democracy in Malawi, their fundamental rights would be recognised and protected under the constitution. What this thesis has demonstrated that despite the existence of democracy in Malawi, it did ultimately result in a society that would be open to diversity. What this study has demonstrated is that Malawi continues to remain a highly conservative society. This is further illustrated in the way Malawian Rastas have had to contend with being denied employment opportunities including their fundamental right to smoke chamba (marijuana) freely. This thesis set out to argue that the democracy brought about by the elections of 1994 did not necessarily result in the improved conditions of minority religious groups like Rastafarians. This is despite the current constitution allowing for religious freedom. Despite this, the thesis further set out to show that the Rastafari movement does have vital role in the current dispensation. The issues that make the Rastafari movement pertinent in present-day Malawi include issues of corruption and neo-colonialism. This thesis concluded that more must be done to improve the conditions of Rastas in Malawi. Some of recommendations that were raised in this study included reviewing the current policy regarding the length of hair that one wears to school as it relates to one’s religious beliefs. The other recommendation that was raised in this study includes amending the Religious and Moral Education (RME) school curriculum in order that it becomes inclusive of other religious faiths that are existing in the country. In addition, the current legislation regarding the possession of chamba must be amended to accommodate for religious groups such as Rastas who use it for religious purposes.
- Full Text:
- Date Issued: 2019
Influence of laser surface treatment on residual stress distribution and dynamic properties in rotary friction welded ti-6al-4v components
- Authors: Tsikayi, Davies Shamiso
- Date: 2019
- Subjects: Lasers -- Industrial applications , Friction welding Pressure welding Metals -- Research
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/43823 , vital:37050
- Description: This manuscript details a study on laser surface treatment, a surface modification technique that is an easily flexible way of improving material surface properties of complex geometries. The research explored the potential of laser surface modification/treatment as a post welding surface processing technique for RFW Ti-6Al-4V ELI components by evaluating the microstructural effects, influence on fatigue life and the depth and magnitude of residual stresses induced. The outcome of this study reveals how post processing by laser surface modification affects crack initiation hence fatigue life and further explains mechanisms potentially contributing to enhanced joint properties. This study was accomplished by investigating the effect of laser surface treatment on surface properties of hourglass cylindrical rotary friction welded Ti-6Al-4V ELI specimens. Preliminary work was done in two stages. The first stage involved conducting laser surface treatment on 3 mm Ti-6Al-4V sheets. In this stage, an understanding of the process variables concerning the laser surface treatment process characteristics was established. Laser power and focus position were varied whilst scanning speed was kept constant. The observed macrographs were quantified in terms of laser penetration depth and width. A hardness and microstructural analysis was also conducted on selected specimens of the laser surface treated flat sheets trials. The second stage involved surface treatment of the hourglass fatigue specimen. This preliminary work allowed for the type and influence of treatment strategy to be analysed. The influence of treatment strategy on the depth of penetration was established with an emphasis on achieving homogeneity of the laser surface treated zone’s depth of penetration around the complete cylindrical specimen’s diameter. The final matrix involved varying laser power, scanning speed and focus position and the specimens were characterised by comparing hardness, residual stresses and microstructure. The results showed that laser surface treatment changed the hardness profile of the near surface of the specimen owing to the introduction of a homogenous microstructure at the surface as compared to a friction welded specimen. The microstructure was resolved using electron backscatter diffraction. A fully α-lamella microstructure was observed in the two specimens analysed at a position of 200 μm from the surface. The α-lamella had different width sizes with the low-power density specimen having a very fine microstructure as compared to that of the high-power density specimen. EBSD phase maps were also analysed for the parent, rotary friction welded only and friction welded laser surface treated specimens. The laser treated specimens showed virtually no β phase present as compared to the parent and rotary friction welded only specimens. LST processing improved the fatigue properties of the RFW specimens. The position of failure shifted from the HAZ to outside the RFW joint. This change in position was attributed to the surface modification by LST thereby introducing a more homogenous microstructure at the surface of the specimen. Additionally, it was also observed that the power density had an important role to play in the fatigue properties of the laser surface treated specimens. The high-power density LST specimens had a low fatigue limit compared to the low-power density specimens. The low fatigue limit at high- power density correlated with the residual stress results where the high-power density specimen had the highest attained surface tensile axial residual stresses. In conclusion, the main influences of laser surface treatment of small friction welded Ti-6Al-4V ELI components relate to an increase in fatigue properties by shifting crack initiation sites to less stressed areas. In this way, laser surface treatment could assist in the optimisation of manufacturing methodologies for small near net shape complex geometry components. The uniform and homogenous microstructure eliminates or reduces microstructural variations as observed in as welded components, reducing weld zone hardness variation. Additionally, the study showed that the introduction of a near surface refined microstructure inhibited crack initiation in the welded region.
- Full Text:
- Date Issued: 2019
- Authors: Tsikayi, Davies Shamiso
- Date: 2019
- Subjects: Lasers -- Industrial applications , Friction welding Pressure welding Metals -- Research
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/43823 , vital:37050
- Description: This manuscript details a study on laser surface treatment, a surface modification technique that is an easily flexible way of improving material surface properties of complex geometries. The research explored the potential of laser surface modification/treatment as a post welding surface processing technique for RFW Ti-6Al-4V ELI components by evaluating the microstructural effects, influence on fatigue life and the depth and magnitude of residual stresses induced. The outcome of this study reveals how post processing by laser surface modification affects crack initiation hence fatigue life and further explains mechanisms potentially contributing to enhanced joint properties. This study was accomplished by investigating the effect of laser surface treatment on surface properties of hourglass cylindrical rotary friction welded Ti-6Al-4V ELI specimens. Preliminary work was done in two stages. The first stage involved conducting laser surface treatment on 3 mm Ti-6Al-4V sheets. In this stage, an understanding of the process variables concerning the laser surface treatment process characteristics was established. Laser power and focus position were varied whilst scanning speed was kept constant. The observed macrographs were quantified in terms of laser penetration depth and width. A hardness and microstructural analysis was also conducted on selected specimens of the laser surface treated flat sheets trials. The second stage involved surface treatment of the hourglass fatigue specimen. This preliminary work allowed for the type and influence of treatment strategy to be analysed. The influence of treatment strategy on the depth of penetration was established with an emphasis on achieving homogeneity of the laser surface treated zone’s depth of penetration around the complete cylindrical specimen’s diameter. The final matrix involved varying laser power, scanning speed and focus position and the specimens were characterised by comparing hardness, residual stresses and microstructure. The results showed that laser surface treatment changed the hardness profile of the near surface of the specimen owing to the introduction of a homogenous microstructure at the surface as compared to a friction welded specimen. The microstructure was resolved using electron backscatter diffraction. A fully α-lamella microstructure was observed in the two specimens analysed at a position of 200 μm from the surface. The α-lamella had different width sizes with the low-power density specimen having a very fine microstructure as compared to that of the high-power density specimen. EBSD phase maps were also analysed for the parent, rotary friction welded only and friction welded laser surface treated specimens. The laser treated specimens showed virtually no β phase present as compared to the parent and rotary friction welded only specimens. LST processing improved the fatigue properties of the RFW specimens. The position of failure shifted from the HAZ to outside the RFW joint. This change in position was attributed to the surface modification by LST thereby introducing a more homogenous microstructure at the surface of the specimen. Additionally, it was also observed that the power density had an important role to play in the fatigue properties of the laser surface treated specimens. The high-power density LST specimens had a low fatigue limit compared to the low-power density specimens. The low fatigue limit at high- power density correlated with the residual stress results where the high-power density specimen had the highest attained surface tensile axial residual stresses. In conclusion, the main influences of laser surface treatment of small friction welded Ti-6Al-4V ELI components relate to an increase in fatigue properties by shifting crack initiation sites to less stressed areas. In this way, laser surface treatment could assist in the optimisation of manufacturing methodologies for small near net shape complex geometry components. The uniform and homogenous microstructure eliminates or reduces microstructural variations as observed in as welded components, reducing weld zone hardness variation. Additionally, the study showed that the introduction of a near surface refined microstructure inhibited crack initiation in the welded region.
- Full Text:
- Date Issued: 2019
Innovation: its impact on the success of construction micro, small, and medium enterprises in northern Nigeria
- Authors: Tsado, Abel John
- Date: 2019
- Subjects: Construction industry -- Nigeria , Business enterprises -- Nigeria Success in business -- Nigeria Economics—Environmental aspects
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/44951 , vital:38191
- Description: There is growing recognition of the important role Construction Micro, Small and Medium Enterprises (CMSMEs) play in economic development. In 2013, Nigeria had about 36,994,578 Micro, Small, and Medium Enterprises (MSMEs) and 731,303 CMSMEs, about 1.99% of the total number of MSMEs in the country. However, 50% of CMSMEs in Nigeria close down within their first five years of existence. Consequently, only about 10% of CMSMEs in Nigeria survive, thrive, and grow to maturity. Enterprises failing within so short a time, portend a huge problem surrounding CMSME innovation and success. While literature seems to indicate innovation as the likely way out of CMSMEs failure, few researchers have considered the connection between CMSMEs innovation and their success. Hence, this research aimed to explore the effect of innovation(s) and innovation systems on the success of the Northern Nigerian CMSMEs. The research objectives were: to identify the types of innovation that are predominant in/peculiar to the Northern Nigerian CMSMEs; to determine how the types of innovation impact the success of the Northern Nigerian CMSMEs; to establish what the innovation systems that manage the innovation of the Northern Nigerian CMSMEs are; and, to determine how the innovation systems, promote innovation among the Northern Nigerian CMSMEs. Qualitative research method was utilised; consisting of 17 recorded interviews within Northern Nigerian which is the study area. The interview also employed structured interview guide, comprising structured open-ended questions to ensure consistency and rigour in the data collection process. The research adopted two stage non-probabilistic sampling, comprising judgmental and snowballing sampling for stage one and two respectively. In stage one, participants were drawn judgmentally based on their innovation and in stage two, the sample size was expanded, using a snowballing sampling technique where the participants in stage one suggested other participants who had also been innovative. Data collected were transcribed and open coded, while the codes for innovation types, and innovation impact on CMSME success were developed with the aid of a deductive code earlier developed from literature. The code occurrences were determined and categorised, and themes were developed. These themes were then subjected to interpretation and analysis. The research findings indicate that the predominant type of innovations within the CMSMEs in the northern part of Nigeria are product innovation, management innovation and service innovation. In addition, there are, technological application innovations, logistics innovations and labour innovations. These innovations impact on the profit, capital, customers, workers and the products of the CMSMEs studied. The innovations are responsible for the CMSMEs success periods, reasons for success and their salient points of success. Therefore, the research concludes that innovation impacts on the studied CMSMEs success. Consequently, the research achieved its aim. The study also discovered an absence of systems that support the innovation of CMSMEs in the northern part of Nigeria. Through this research, an innovation system framework has been developed and it is recommended that it be implemented because of the observed lack of innovation systems in Nigeria.
- Full Text:
- Date Issued: 2019
- Authors: Tsado, Abel John
- Date: 2019
- Subjects: Construction industry -- Nigeria , Business enterprises -- Nigeria Success in business -- Nigeria Economics—Environmental aspects
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/44951 , vital:38191
- Description: There is growing recognition of the important role Construction Micro, Small and Medium Enterprises (CMSMEs) play in economic development. In 2013, Nigeria had about 36,994,578 Micro, Small, and Medium Enterprises (MSMEs) and 731,303 CMSMEs, about 1.99% of the total number of MSMEs in the country. However, 50% of CMSMEs in Nigeria close down within their first five years of existence. Consequently, only about 10% of CMSMEs in Nigeria survive, thrive, and grow to maturity. Enterprises failing within so short a time, portend a huge problem surrounding CMSME innovation and success. While literature seems to indicate innovation as the likely way out of CMSMEs failure, few researchers have considered the connection between CMSMEs innovation and their success. Hence, this research aimed to explore the effect of innovation(s) and innovation systems on the success of the Northern Nigerian CMSMEs. The research objectives were: to identify the types of innovation that are predominant in/peculiar to the Northern Nigerian CMSMEs; to determine how the types of innovation impact the success of the Northern Nigerian CMSMEs; to establish what the innovation systems that manage the innovation of the Northern Nigerian CMSMEs are; and, to determine how the innovation systems, promote innovation among the Northern Nigerian CMSMEs. Qualitative research method was utilised; consisting of 17 recorded interviews within Northern Nigerian which is the study area. The interview also employed structured interview guide, comprising structured open-ended questions to ensure consistency and rigour in the data collection process. The research adopted two stage non-probabilistic sampling, comprising judgmental and snowballing sampling for stage one and two respectively. In stage one, participants were drawn judgmentally based on their innovation and in stage two, the sample size was expanded, using a snowballing sampling technique where the participants in stage one suggested other participants who had also been innovative. Data collected were transcribed and open coded, while the codes for innovation types, and innovation impact on CMSME success were developed with the aid of a deductive code earlier developed from literature. The code occurrences were determined and categorised, and themes were developed. These themes were then subjected to interpretation and analysis. The research findings indicate that the predominant type of innovations within the CMSMEs in the northern part of Nigeria are product innovation, management innovation and service innovation. In addition, there are, technological application innovations, logistics innovations and labour innovations. These innovations impact on the profit, capital, customers, workers and the products of the CMSMEs studied. The innovations are responsible for the CMSMEs success periods, reasons for success and their salient points of success. Therefore, the research concludes that innovation impacts on the studied CMSMEs success. Consequently, the research achieved its aim. The study also discovered an absence of systems that support the innovation of CMSMEs in the northern part of Nigeria. Through this research, an innovation system framework has been developed and it is recommended that it be implemented because of the observed lack of innovation systems in Nigeria.
- Full Text:
- Date Issued: 2019
Integration of indigenous knowledge in the intermediate phase school curriculum in a selected education district in the Eastern Cape, South Africa
- Mkosi, Nkosinathi Ndumiso Lizo
- Authors: Mkosi, Nkosinathi Ndumiso Lizo
- Date: 2019
- Subjects: Education -- Curricula -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/16136 , vital:40671
- Description: The aims and principles of the post-apartheid South African school curricula, ranging from the Revised National Curriculum Statement Grades R-9 and the National Curriculum Statement Grades 10-12, to include the Curriculum and Assessment Policy Statements (Grades 1-12), have been aligned with the aims and principles of the South African Constitution. The aims and principles, among others, speak to the establishment of human rights, inclusivity, environmental and social justice, and valuing of indigenous knowledge systems. These are the bedrock of all the subjects and do not necessarily confine themselves to the science subjects only; even though the call of inclusion of indigenous knowledge in the sciences is oversubscribed. There has been concerns raised variously that the integration of indigenous knowledge systems in the curriculum, generally, and in the teaching of the respective subjects, particularly, does not necessarily happen as it should be. Thus, the purpose of this mixed methods approach study that adopted a concurrent triangulation mixed methods design and premised on the postpositivist paradigm investigated the integration of indigenous knowledge in the Intermediate Phase school curriculum in a selected Education District in the Eastern Cape Province, South Africa. The guiding lenses adopted for this study were two-fold. The main primary theoretical framework drew from three integration theories: (a) Huang and Newell’s (2003) Knowledge Integration Processes and Dynamics notions; (b) Beane’s (1995) Curriculum Integration and the Disciplines of Knowledge and (c) Harden’s (2000) Integration ladder: A Tool for Curriculum Planning and Evaluation. The ‘secondary’ lens of analysis, which the researcher named, the ‘supplemental framework’, was constituted by notions and constructs derived from the indigenous knowledge systems discourses and postcolonial notions and constructs. The study revealed, among other findings, that (i) whilst a majority of teachers claimed to integrate IK in their classrooms, a significant number did not, and those who claimed to be integrating were unsure about how to integrate (ii) the majority of teachers, HoDs and Subject Advisors were either poorly trained or did not receive any training in the integration of IK (iii) the support and monitoring of IK integration was poor to non-existent. Thus, the study proposes a model, the Integrative Indigenous Knowledge Integration Support and Monitoring Model (IIKISMM), which may act as a framework for the coordination of the support and monitoring of IK integration in the school curriculum. There are significant recommendations offered by the study to teachers and policy makers with regards the integration of indigenous knowledge systems in the school curriculum. Also offered by the study are possibilities for further research in the integration of indigenous knowledge system in the curriculum.
- Full Text:
- Date Issued: 2019
- Authors: Mkosi, Nkosinathi Ndumiso Lizo
- Date: 2019
- Subjects: Education -- Curricula -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/16136 , vital:40671
- Description: The aims and principles of the post-apartheid South African school curricula, ranging from the Revised National Curriculum Statement Grades R-9 and the National Curriculum Statement Grades 10-12, to include the Curriculum and Assessment Policy Statements (Grades 1-12), have been aligned with the aims and principles of the South African Constitution. The aims and principles, among others, speak to the establishment of human rights, inclusivity, environmental and social justice, and valuing of indigenous knowledge systems. These are the bedrock of all the subjects and do not necessarily confine themselves to the science subjects only; even though the call of inclusion of indigenous knowledge in the sciences is oversubscribed. There has been concerns raised variously that the integration of indigenous knowledge systems in the curriculum, generally, and in the teaching of the respective subjects, particularly, does not necessarily happen as it should be. Thus, the purpose of this mixed methods approach study that adopted a concurrent triangulation mixed methods design and premised on the postpositivist paradigm investigated the integration of indigenous knowledge in the Intermediate Phase school curriculum in a selected Education District in the Eastern Cape Province, South Africa. The guiding lenses adopted for this study were two-fold. The main primary theoretical framework drew from three integration theories: (a) Huang and Newell’s (2003) Knowledge Integration Processes and Dynamics notions; (b) Beane’s (1995) Curriculum Integration and the Disciplines of Knowledge and (c) Harden’s (2000) Integration ladder: A Tool for Curriculum Planning and Evaluation. The ‘secondary’ lens of analysis, which the researcher named, the ‘supplemental framework’, was constituted by notions and constructs derived from the indigenous knowledge systems discourses and postcolonial notions and constructs. The study revealed, among other findings, that (i) whilst a majority of teachers claimed to integrate IK in their classrooms, a significant number did not, and those who claimed to be integrating were unsure about how to integrate (ii) the majority of teachers, HoDs and Subject Advisors were either poorly trained or did not receive any training in the integration of IK (iii) the support and monitoring of IK integration was poor to non-existent. Thus, the study proposes a model, the Integrative Indigenous Knowledge Integration Support and Monitoring Model (IIKISMM), which may act as a framework for the coordination of the support and monitoring of IK integration in the school curriculum. There are significant recommendations offered by the study to teachers and policy makers with regards the integration of indigenous knowledge systems in the school curriculum. Also offered by the study are possibilities for further research in the integration of indigenous knowledge system in the curriculum.
- Full Text:
- Date Issued: 2019
Management capacity within small and medium tourism enterprises (SMTEs)
- Authors: Mxunyelwa, Siyabonga
- Date: 2019
- Subjects: Small business -- South Africa -- Eastern Cape -- Management , Tourism -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/41708 , vital:36574
- Description: The small to medium tourism enterprises are identified as important contributors to the growth of the local and regional economies and creates much needed entrepreneurial ventures. Universally, small to medium tourism enterprises play a significant role in the tourism sector. The small businesses are in many instances deemed to facing risk to economic environmental challenges and face uphill battles to operate their enterprises in a sustainable manner. Management of these enterprises by owners and managers seems to face challenges. This study focuses on small to medium tourism enterprises in the Eastern Cape Province, South Africa, which faces the triple threat challenges of poverty, inequality and unemployment, and is one of the economically poorest provinces of South Africa. In an endeavour to create a trajectory for progression and development of small to medium tourism enterprises, owners and managers are required to undertake management capacity programmes to deal with the problems that confront the enterprise on a daily basis. The study examines the factors impacting on management capacity with specific focus on the small to medium tourism enterprises in the Eastern Cape Province, South Africa. Management capacity is paramount as it builds managerial competency and has become significant to the small business economy, as these enterprises make every effort to avoid discontinuation. Management capacity improves business performance and small enterprises require help in order to have a broader understanding of issues that can be an impediment to address the challenges in the business environment. The factors that could impact on management capacity within the enterprises are the focus of this research. The eleven main factors were identified, namely skills development; reasons for starting a business; business challenges; strategic and management knowledge; business leadership; business resources, business environment; business communication; business organisational leadership; organisational strategy; and organisational information factors. Furthermore, the study examined the level of influence of these factors on the management capacity of small businesses in the tourism and hospitality sector in the Eastern Cape and investigated the relationships between these factors. A descriptive research design and a quantitative approach were considered suitable for this study. A systematic random sampling technique was utilised to choose a sample of 320 business respondents from the 2012 database of the Eastern Cape Parks and Tourism Agency, comprising of formally registered small tourism businesses. A total of 310 usable questionnaires was finally obtained. In this study descriptive and inferential statistics were applied. Descriptive statistics were captured to highlight the owners and managers’ general characteristics and to consolidate their measurement scores. Utilising inferential statistics, the study undertook an investigation into relationships between demographic variables and business characteristics. Furthermore, an investigation of the relationships amongst the following factors: skills development; reasons for starting a business; business challenges; strategic and management knowledge; business leadership; business resources, business environment; business communication; business organisational leadership; organisational strategy and organisational information factors was undertaken. Data were subjected to exploratory factor analysis and both the validity and reliability of the research instrument was assessed. The research findings support an overall significant correlation between management capacity and skills development; reasons for starting a business; business challenges; strategic and management knowledge; business leadership; business resources, business environment; business communication; business organisational leadership; organisational strategy and organisational information. The study also explored the relationship between demographics and business characteristics. A significant relationship was found between business characteristics and variables in the demographic profile, namely the gender of owners/managers, educational levels, qualifications, and gross annual turnover. What follows is a summation of the most significant contributions of this research. The overview of the significance of the tourism sector in the economy and the role of small businesses in the tourism and hospitality industry of the Eastern Cape will benefit researchers and potential owners/managers who have an interest in this developing sector. The study enhances the understanding of the factors that relate to management capacity. The study has established a profile of SMTE sector in the Eastern Cape, South Africa, which can play a significant role for future research. This research makes a contribution to the largely under-researched area of management capacity in small to medium tourism enterprises. Recommendations for owners/managers and consideration of future research included the following. Owners/managers need to have management skills and a strong strategic focus. Through management capacity the needs of the business will be addressed, and capacity building programmes can be tailored to maximise the benefits for owners/managers of SMTEs, thereby improving business performance and avoiding high failure rate. Managers need to be effectively trained to deal with business needs. The management of the business plays a pivotal role in the performance of the enterprise. Managers must be skilled with regards to developing strategic plans, marketing plans, and business plans, thus enhancing management capacity. Longitudinal studies can be undertaken to investigating the same factors which could impact on management capacity. It is recommended that this study be replicated across the global spectrum in order to analyse the factors that impact on management capacity of small to medium tourism businesses of other countries.
- Full Text:
- Date Issued: 2019
- Authors: Mxunyelwa, Siyabonga
- Date: 2019
- Subjects: Small business -- South Africa -- Eastern Cape -- Management , Tourism -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/41708 , vital:36574
- Description: The small to medium tourism enterprises are identified as important contributors to the growth of the local and regional economies and creates much needed entrepreneurial ventures. Universally, small to medium tourism enterprises play a significant role in the tourism sector. The small businesses are in many instances deemed to facing risk to economic environmental challenges and face uphill battles to operate their enterprises in a sustainable manner. Management of these enterprises by owners and managers seems to face challenges. This study focuses on small to medium tourism enterprises in the Eastern Cape Province, South Africa, which faces the triple threat challenges of poverty, inequality and unemployment, and is one of the economically poorest provinces of South Africa. In an endeavour to create a trajectory for progression and development of small to medium tourism enterprises, owners and managers are required to undertake management capacity programmes to deal with the problems that confront the enterprise on a daily basis. The study examines the factors impacting on management capacity with specific focus on the small to medium tourism enterprises in the Eastern Cape Province, South Africa. Management capacity is paramount as it builds managerial competency and has become significant to the small business economy, as these enterprises make every effort to avoid discontinuation. Management capacity improves business performance and small enterprises require help in order to have a broader understanding of issues that can be an impediment to address the challenges in the business environment. The factors that could impact on management capacity within the enterprises are the focus of this research. The eleven main factors were identified, namely skills development; reasons for starting a business; business challenges; strategic and management knowledge; business leadership; business resources, business environment; business communication; business organisational leadership; organisational strategy; and organisational information factors. Furthermore, the study examined the level of influence of these factors on the management capacity of small businesses in the tourism and hospitality sector in the Eastern Cape and investigated the relationships between these factors. A descriptive research design and a quantitative approach were considered suitable for this study. A systematic random sampling technique was utilised to choose a sample of 320 business respondents from the 2012 database of the Eastern Cape Parks and Tourism Agency, comprising of formally registered small tourism businesses. A total of 310 usable questionnaires was finally obtained. In this study descriptive and inferential statistics were applied. Descriptive statistics were captured to highlight the owners and managers’ general characteristics and to consolidate their measurement scores. Utilising inferential statistics, the study undertook an investigation into relationships between demographic variables and business characteristics. Furthermore, an investigation of the relationships amongst the following factors: skills development; reasons for starting a business; business challenges; strategic and management knowledge; business leadership; business resources, business environment; business communication; business organisational leadership; organisational strategy and organisational information factors was undertaken. Data were subjected to exploratory factor analysis and both the validity and reliability of the research instrument was assessed. The research findings support an overall significant correlation between management capacity and skills development; reasons for starting a business; business challenges; strategic and management knowledge; business leadership; business resources, business environment; business communication; business organisational leadership; organisational strategy and organisational information. The study also explored the relationship between demographics and business characteristics. A significant relationship was found between business characteristics and variables in the demographic profile, namely the gender of owners/managers, educational levels, qualifications, and gross annual turnover. What follows is a summation of the most significant contributions of this research. The overview of the significance of the tourism sector in the economy and the role of small businesses in the tourism and hospitality industry of the Eastern Cape will benefit researchers and potential owners/managers who have an interest in this developing sector. The study enhances the understanding of the factors that relate to management capacity. The study has established a profile of SMTE sector in the Eastern Cape, South Africa, which can play a significant role for future research. This research makes a contribution to the largely under-researched area of management capacity in small to medium tourism enterprises. Recommendations for owners/managers and consideration of future research included the following. Owners/managers need to have management skills and a strong strategic focus. Through management capacity the needs of the business will be addressed, and capacity building programmes can be tailored to maximise the benefits for owners/managers of SMTEs, thereby improving business performance and avoiding high failure rate. Managers need to be effectively trained to deal with business needs. The management of the business plays a pivotal role in the performance of the enterprise. Managers must be skilled with regards to developing strategic plans, marketing plans, and business plans, thus enhancing management capacity. Longitudinal studies can be undertaken to investigating the same factors which could impact on management capacity. It is recommended that this study be replicated across the global spectrum in order to analyse the factors that impact on management capacity of small to medium tourism businesses of other countries.
- Full Text:
- Date Issued: 2019
Mechanisms and modes of β-N-methylamino-lalanine neurotoxicity: the basis for designing therapies
- Authors: Van Onselen, Rianita
- Date: 2019
- Subjects: Cyanobacteria , Amino acids -- Toxicology , Neurotoxic agents
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/32971 , vital:32483
- Description: Since the discovery of the non-canonical amino acid β-N-methylamino-L-alanine (BMAA) and the demonstration of its acute neurotoxicity in chicks and rats, it has been postulated that BMAA might contribute to the development of neurodegenerative diseases worldwide due to its presence in numerous aquatic and terrestrial food webs. This hypothesized link was widely criticized because of the inability to reproduce symptoms in a BMAA-exposed animal model that resembled the symptoms observed in humans, and for the inability to achieve significant levels of toxicity in in vitro models via the postulated mechanisms of toxicity. The most widely described mechanism of BMAA toxicity was excitotoxicity by over-excitation of ionotropic and/or metabotropic glutamate receptors following activation by BMAA. However, the excitotoxic potency of BMAA is much lower than those of other known excitotoxins and it was not known whether BMAA could accumulate in significant concentrations in synapses to cause the said excitotoxicity. Therefore, uptake of BMAA into synaptic vesicles from where it can be released into synapses in high concentrations, was investigated and it was found that, unlike the uptake that was observed for glutamate, BMAA was not taken up into synaptic vesicles. This discovery suggests that BMAA is not released into synapses via synaptic vesicles and that excitotoxicity is an unlikely mechanism of BMAA toxicity in mammalian systems. Misincorporation of BMAA into proteins in the place of L-serine was suggested to be an important mechanism of BMAA toxicity that could lead to protein misfolding and the subsequent protein aggregates that are typically found in the central nervous system (CNS) of neurodegenerative disease patients. However, previous studies in prokaryotes and in a rat pheochromocytoma PC12 cell line showed that misincorporation of BMAA does not occur to any significant extent. However, these studies were criticized for not using human-derived model systems to show that misincorporation does not occur, and it was argued that due to differences in mitochondrial protein synthesis mechanisms, misincorporation of BMAA into human proteins could not be ruled out as a possible mechanism of toxicity. Therefore, misincorporation of BMAA was investigated in a number of human-derived non-neuronal cell lines and directly compared to the misincorporation of other known amino acid analogues. No evidence of misincorporation of BMAA into these cell lines was obtained and therefore it was concluded that misincorporation of BMAA into proteins does not occur in human-derived cell models. Although misincorporation of BMAA into proteins was refuted as a mechanism of toxicity, the strong interactions between BMAA and proteins that require extensive purification procedures to remove the associated BMAA, could not be discounted as a possible contributor to the toxicity of BMAA. Cell-free interactions between BMAA and enzymes, which resulted in reduced activity, were described previously but the nature of these interactions was never determined. Therefore, the direct interactions between BMAA and a range of commercial proteins and melanin (that is known to also have a strong affinity for BMAA) were investigated in an attempt to describe the nature of these interactions. It was discovered that BMAA has a high affinity for hydroxyl groups, and that if these hydroxyl groups in the form of hydroxyl containing amino acid residues occurred in important regulatory or active sites of proteins, BMAA reduced the enzyme activity. Catalase was subsequently selected as an important enzyme required for the maintenance of the delicate reactive oxygen species (ROS) balance in the CNS, to test the effect of BMAA on the activity of the enzyme. BMAA inhibited a human commercial extract of catalase in a cell free system, and this inhibition appeared to be non-competitive in nature. Subsequently, catalase in an extract from a human cell line was also shown to be inhibited by BMAA and it was concluded that this BMAA induced inhibition of catalase could be an important contributor to the toxicity of BMAA in in vivo systems. The affinity of BMAA for hydroxyl groups, especially the reactive L-tyrosine side chain hydroxyl, was recognized as a possible mechanism that can be utilized to protect against the toxicity of BMAA. It was subsequently shown that excess concentrations of L-serine and L-tyrosine could protect against the BMAA-induced enzyme inhibition and improper folding of proteins in a cell-free system. By administering an equimolar concentration of either L-phenylalanine (the soluble precursor of L-tyrosine) or L-serine an hour before administration of BMAA in a rat model, the BMAA-induced neurotoxicity was greatly reduced, especially by treatment with L-phenylalanine, which resulted in a decrease of between 60-70% in the observed neuropathologies. It was recognized that the protection offered by L-phenylalanine was greater than would be expected if protection was by virtue of direct hydroxyl binding alone and it was subsequently hypothesized that the conversion of L-phenylalanine to dopamine could have contributed to the observed protection. Subsequently, the possible protection offered by dopamine, administered as L-DOPA, against BMAA neurotoxicity was investigated in the same neonatal rat model and compared to the protection offered by L-tyrosine. It was discovered that dopamine protected against the BMAAinduced neuronal cell losses in the hippocampus, striatum and spinal cord but it was not as efficient as L-tyrosine in protection against the BMAA-induced proteinopathies, suggesting two distinct mechanisms of BMAA toxicity, one of which is a depletion of dopamine, which had not been previously described. Finally, the nature of the BMAA-induced dopamine depletion was investigated by administering BMAA in combination with other dopaminergic modifiers viz. apomorphine (a D1/D2 receptor agonist), a dopamine transporter inhibitor (GBR12783) and reserpine (a vesicular monoamine transporter -VMAT2- inhibitor) to the neonatal rat model in an attempt to describe how BMAA functions as a dopaminergic toxin. Based on these results it was concluded that BMAA inhibits uptake of dopamine into synaptic vesicles by inhibiting VMAT2-mediated uptake of dopamine, which causes neuronal loss in the hippocampus, striatum and substantia nigra pars compacta, and that the BMAA-induced inhibition of catalase contributes significantly to the toxicity of BMAA by causing an accumulation of hydrogen peroxide in the hippocampus, striatum and spinal cord, which results in extensive neuronal damage in these areas. This work was the first to thoroughly investigate the mechanisms that explain the observed pathologies caused by BMAA in an in vivo model, and was the first to suggest that BMAA can reduce the dopamine in the CNS by inhibiting VMAT2-mediated uptake of dopamine into synaptic vesicles, and increase damage by reactive oxygen species by inhibiting catalase. BMAA is therefore a multimechanistic and multimodal.
- Full Text:
- Date Issued: 2019
- Authors: Van Onselen, Rianita
- Date: 2019
- Subjects: Cyanobacteria , Amino acids -- Toxicology , Neurotoxic agents
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/32971 , vital:32483
- Description: Since the discovery of the non-canonical amino acid β-N-methylamino-L-alanine (BMAA) and the demonstration of its acute neurotoxicity in chicks and rats, it has been postulated that BMAA might contribute to the development of neurodegenerative diseases worldwide due to its presence in numerous aquatic and terrestrial food webs. This hypothesized link was widely criticized because of the inability to reproduce symptoms in a BMAA-exposed animal model that resembled the symptoms observed in humans, and for the inability to achieve significant levels of toxicity in in vitro models via the postulated mechanisms of toxicity. The most widely described mechanism of BMAA toxicity was excitotoxicity by over-excitation of ionotropic and/or metabotropic glutamate receptors following activation by BMAA. However, the excitotoxic potency of BMAA is much lower than those of other known excitotoxins and it was not known whether BMAA could accumulate in significant concentrations in synapses to cause the said excitotoxicity. Therefore, uptake of BMAA into synaptic vesicles from where it can be released into synapses in high concentrations, was investigated and it was found that, unlike the uptake that was observed for glutamate, BMAA was not taken up into synaptic vesicles. This discovery suggests that BMAA is not released into synapses via synaptic vesicles and that excitotoxicity is an unlikely mechanism of BMAA toxicity in mammalian systems. Misincorporation of BMAA into proteins in the place of L-serine was suggested to be an important mechanism of BMAA toxicity that could lead to protein misfolding and the subsequent protein aggregates that are typically found in the central nervous system (CNS) of neurodegenerative disease patients. However, previous studies in prokaryotes and in a rat pheochromocytoma PC12 cell line showed that misincorporation of BMAA does not occur to any significant extent. However, these studies were criticized for not using human-derived model systems to show that misincorporation does not occur, and it was argued that due to differences in mitochondrial protein synthesis mechanisms, misincorporation of BMAA into human proteins could not be ruled out as a possible mechanism of toxicity. Therefore, misincorporation of BMAA was investigated in a number of human-derived non-neuronal cell lines and directly compared to the misincorporation of other known amino acid analogues. No evidence of misincorporation of BMAA into these cell lines was obtained and therefore it was concluded that misincorporation of BMAA into proteins does not occur in human-derived cell models. Although misincorporation of BMAA into proteins was refuted as a mechanism of toxicity, the strong interactions between BMAA and proteins that require extensive purification procedures to remove the associated BMAA, could not be discounted as a possible contributor to the toxicity of BMAA. Cell-free interactions between BMAA and enzymes, which resulted in reduced activity, were described previously but the nature of these interactions was never determined. Therefore, the direct interactions between BMAA and a range of commercial proteins and melanin (that is known to also have a strong affinity for BMAA) were investigated in an attempt to describe the nature of these interactions. It was discovered that BMAA has a high affinity for hydroxyl groups, and that if these hydroxyl groups in the form of hydroxyl containing amino acid residues occurred in important regulatory or active sites of proteins, BMAA reduced the enzyme activity. Catalase was subsequently selected as an important enzyme required for the maintenance of the delicate reactive oxygen species (ROS) balance in the CNS, to test the effect of BMAA on the activity of the enzyme. BMAA inhibited a human commercial extract of catalase in a cell free system, and this inhibition appeared to be non-competitive in nature. Subsequently, catalase in an extract from a human cell line was also shown to be inhibited by BMAA and it was concluded that this BMAA induced inhibition of catalase could be an important contributor to the toxicity of BMAA in in vivo systems. The affinity of BMAA for hydroxyl groups, especially the reactive L-tyrosine side chain hydroxyl, was recognized as a possible mechanism that can be utilized to protect against the toxicity of BMAA. It was subsequently shown that excess concentrations of L-serine and L-tyrosine could protect against the BMAA-induced enzyme inhibition and improper folding of proteins in a cell-free system. By administering an equimolar concentration of either L-phenylalanine (the soluble precursor of L-tyrosine) or L-serine an hour before administration of BMAA in a rat model, the BMAA-induced neurotoxicity was greatly reduced, especially by treatment with L-phenylalanine, which resulted in a decrease of between 60-70% in the observed neuropathologies. It was recognized that the protection offered by L-phenylalanine was greater than would be expected if protection was by virtue of direct hydroxyl binding alone and it was subsequently hypothesized that the conversion of L-phenylalanine to dopamine could have contributed to the observed protection. Subsequently, the possible protection offered by dopamine, administered as L-DOPA, against BMAA neurotoxicity was investigated in the same neonatal rat model and compared to the protection offered by L-tyrosine. It was discovered that dopamine protected against the BMAAinduced neuronal cell losses in the hippocampus, striatum and spinal cord but it was not as efficient as L-tyrosine in protection against the BMAA-induced proteinopathies, suggesting two distinct mechanisms of BMAA toxicity, one of which is a depletion of dopamine, which had not been previously described. Finally, the nature of the BMAA-induced dopamine depletion was investigated by administering BMAA in combination with other dopaminergic modifiers viz. apomorphine (a D1/D2 receptor agonist), a dopamine transporter inhibitor (GBR12783) and reserpine (a vesicular monoamine transporter -VMAT2- inhibitor) to the neonatal rat model in an attempt to describe how BMAA functions as a dopaminergic toxin. Based on these results it was concluded that BMAA inhibits uptake of dopamine into synaptic vesicles by inhibiting VMAT2-mediated uptake of dopamine, which causes neuronal loss in the hippocampus, striatum and substantia nigra pars compacta, and that the BMAA-induced inhibition of catalase contributes significantly to the toxicity of BMAA by causing an accumulation of hydrogen peroxide in the hippocampus, striatum and spinal cord, which results in extensive neuronal damage in these areas. This work was the first to thoroughly investigate the mechanisms that explain the observed pathologies caused by BMAA in an in vivo model, and was the first to suggest that BMAA can reduce the dopamine in the CNS by inhibiting VMAT2-mediated uptake of dopamine into synaptic vesicles, and increase damage by reactive oxygen species by inhibiting catalase. BMAA is therefore a multimechanistic and multimodal.
- Full Text:
- Date Issued: 2019