Exploring Ubuntu as service leadership competency
- Authors: Bangushe, Anele Greatjoy
- Date: 2022-10-14
- Subjects: Leadership Moral and ethical aspects , Ubuntu (Philosophy) , Methodist Church of South Africa , Servant leadership South Africa Makhanda , Christian leadership South Africa Makhanda , Community leadership South Africa Makhanda , Critical incident technique
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/380743 , vital:67488
- Description: This is a case study conducted in the Methodist Church of Southern Africa (MCSA), Grahamstown, in the Eastern Cape. Against the backdrop of identifying and conceptualising ethically oriented leadership competencies, the purpose of this study was to explore service as a leadership competency. The literature reviewed in this research underscored the importance of effective and ethical leadership, but critiqued the Westernised, individualistic orientation of the conceptualisation of service as a leadership competency. Based on a review of the literature, this study proposes that when African leaders are in leadership four components of Ubuntu are involved when they exercise service as a leadership competency. These components are collective consideration, collective compassion, community server and Ubuntu humility. The main aim of this study is to investigate if leaders display these four components when exercising service towards their followers, and if so, how, and why they do so. A conceptual framework of components of Ubuntu, which culminated in research themes and propositions, were produced from the literature chapter. A qualitative research method was adopted in this study in which eight participants were selected through convenience sampling for this case study. One minister and seven Vice-Presidents of various organisations in the Methodist Church were interviewed. Semi-structured interviews were conducted for data collection and a deductive thematic analysis approach was employed to analyse data. Also, the critical incident technique (CIT) was utilised to structure interview questions, which is best fitting to solicit complex and comprehensive data from the interviewees. In its findings, the study confirmed the presence of the four components of Ubuntu, but several delimitations and limitations are acknowledged. Nevertheless, the study has made some contribution to understanding the display of service as a leadership competency in an African context. The implications for management practice are considered and recommendations made for future research. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Bangushe, Anele Greatjoy
- Date: 2022-10-14
- Subjects: Leadership Moral and ethical aspects , Ubuntu (Philosophy) , Methodist Church of South Africa , Servant leadership South Africa Makhanda , Christian leadership South Africa Makhanda , Community leadership South Africa Makhanda , Critical incident technique
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/380743 , vital:67488
- Description: This is a case study conducted in the Methodist Church of Southern Africa (MCSA), Grahamstown, in the Eastern Cape. Against the backdrop of identifying and conceptualising ethically oriented leadership competencies, the purpose of this study was to explore service as a leadership competency. The literature reviewed in this research underscored the importance of effective and ethical leadership, but critiqued the Westernised, individualistic orientation of the conceptualisation of service as a leadership competency. Based on a review of the literature, this study proposes that when African leaders are in leadership four components of Ubuntu are involved when they exercise service as a leadership competency. These components are collective consideration, collective compassion, community server and Ubuntu humility. The main aim of this study is to investigate if leaders display these four components when exercising service towards their followers, and if so, how, and why they do so. A conceptual framework of components of Ubuntu, which culminated in research themes and propositions, were produced from the literature chapter. A qualitative research method was adopted in this study in which eight participants were selected through convenience sampling for this case study. One minister and seven Vice-Presidents of various organisations in the Methodist Church were interviewed. Semi-structured interviews were conducted for data collection and a deductive thematic analysis approach was employed to analyse data. Also, the critical incident technique (CIT) was utilised to structure interview questions, which is best fitting to solicit complex and comprehensive data from the interviewees. In its findings, the study confirmed the presence of the four components of Ubuntu, but several delimitations and limitations are acknowledged. Nevertheless, the study has made some contribution to understanding the display of service as a leadership competency in an African context. The implications for management practice are considered and recommendations made for future research. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2022
- Full Text:
- Date Issued: 2022-10-14
Potential of the Gravel Filter Towers, Pilot-scale Filter system and Biochar/Clay adsorbents for Bio-Physicochemical remediation and Desalination of greywater
- Authors: Bani, Siphumze
- Date: 2021-10-29
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/188375 , vital:44748
- Description: Thesis embargoed until 2023 , Thesis (MSc) -- Faculty of Science, Rhodes University Biotechnology Innovation Centre, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Bani, Siphumze
- Date: 2021-10-29
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/188375 , vital:44748
- Description: Thesis embargoed until 2023 , Thesis (MSc) -- Faculty of Science, Rhodes University Biotechnology Innovation Centre, 2021
- Full Text:
- Date Issued: 2021-10-29
Perceptions of teachers on the implementation of positive learner discipline: A case study of three primary schools in the Amathole-West Education District
- Authors: Bantom, Laetitia Anneline
- Date: 2020-06
- Subjects: School discipline , Classroom management
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/19980 , vital:44915
- Description: The aim of this study was to gain an insight into perceptions of teachers on the implementation of positive learner discipline in three primary schools in the Amathole- West Education District. The study was in the interpretive paradigm and adopted a qualitative approach in the collection of data. A case study design through face-to-face interviews and document analysis related to positive discipline were used for data collection. Three schools were selected through purposive sampling. Four teachers per school participated in the study and these were purposively sampled. Data from the findings were thematically presented and analysed by scrutinizing it for commonalities. The study revealed that teachers had ample knowledge on positive learner discipline and therefore tried to implement it to the best of their abilities. The study also established that teachers perceived positive discipline as a good approach for disciplining learners. Participants were aware that positive learner discipline made learners feel and that it assisted them to improve and sustain good behaviour. Data revealed that schools used different strategies to implement positive learner discipline, such as, class rules, rewards and awards, personal relationship with learners, role model, communication with learners, point system, goal setting, hand-system and sign language, isolated area in front of the classroom, positive attention and guidelines on discipline. In contrast, the study also revealed that a minority of teachers still administered corporal punishment, which is unlawful and traditional. They also applied punitive disciplinary measures. The study concluded that the selected schools encountered various challenges on the implementation of positive learner discipline. These included undisciplined learners, limited involvement and minimal support from the Department of Education (DoE) and limited support from the School Management Team (SMT), uninformed, ignorant and rude parents, lack of parental involvement, parents using punitive measures, no proper training for teachers and parents, overcrowded classrooms and unhappy teachers. As for monitoring and support from the SMT and DoE, the study envisaged that most participants were supported by the SMT, other than the DoE. , Thesis (MEd) -- Faculty of Education, 2020
- Full Text:
- Date Issued: 2020-06
- Authors: Bantom, Laetitia Anneline
- Date: 2020-06
- Subjects: School discipline , Classroom management
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/19980 , vital:44915
- Description: The aim of this study was to gain an insight into perceptions of teachers on the implementation of positive learner discipline in three primary schools in the Amathole- West Education District. The study was in the interpretive paradigm and adopted a qualitative approach in the collection of data. A case study design through face-to-face interviews and document analysis related to positive discipline were used for data collection. Three schools were selected through purposive sampling. Four teachers per school participated in the study and these were purposively sampled. Data from the findings were thematically presented and analysed by scrutinizing it for commonalities. The study revealed that teachers had ample knowledge on positive learner discipline and therefore tried to implement it to the best of their abilities. The study also established that teachers perceived positive discipline as a good approach for disciplining learners. Participants were aware that positive learner discipline made learners feel and that it assisted them to improve and sustain good behaviour. Data revealed that schools used different strategies to implement positive learner discipline, such as, class rules, rewards and awards, personal relationship with learners, role model, communication with learners, point system, goal setting, hand-system and sign language, isolated area in front of the classroom, positive attention and guidelines on discipline. In contrast, the study also revealed that a minority of teachers still administered corporal punishment, which is unlawful and traditional. They also applied punitive disciplinary measures. The study concluded that the selected schools encountered various challenges on the implementation of positive learner discipline. These included undisciplined learners, limited involvement and minimal support from the Department of Education (DoE) and limited support from the School Management Team (SMT), uninformed, ignorant and rude parents, lack of parental involvement, parents using punitive measures, no proper training for teachers and parents, overcrowded classrooms and unhappy teachers. As for monitoring and support from the SMT and DoE, the study envisaged that most participants were supported by the SMT, other than the DoE. , Thesis (MEd) -- Faculty of Education, 2020
- Full Text:
- Date Issued: 2020-06
Inflation, credit markets and economic growth: the case of BRICS Countries
- Authors: Barayi, Bavuyile
- Date: 2021-12
- Subjects: Economic development -- BRIC countries , Inflation (Finance) -- BRIC countries
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53700 , vital:45714
- Description: The empirical study investigates the relationship between inflation, credit markets and economic growth in the context of Brazil, Russia, India, China and South Africa (BRICS) countries. The BRICS group consists of five emerging market economies and was first coined by Jim O’Neil of Goldman Sachs in 2001 whereby initially the bloc consisted of only Brazil, Russia, India, China, South Africa joined the BRICS group in 2010. The BRICS bloc was deemed to be the top fast-growing economies that showed great potential for growth. Consequent to the 2008 global financial crisis, there has been a large change in economic thinking as policy-makers have struggled to overcome the economic misfortunes caused by the crisis. Amongst the emerging countries, the BRICS countries have in effect, established a New Development Bank to play the role of the credit facilitator the BRICS countries and other emerging countries as well. This BRICS New Development Bank was established in 2014 and already has identified and funded some projects within the BRICS countries. Moreover, the main objective of this bank is to provide credit to be utilised for infrastructure, climate change measures, as well as to ensure sustainable development. Against this backdrop, the current study investigates the role played by credit and the extent of development in credit markets on enhancing growth in the BRICS countries, particularly looking at the levels of inflation that are conducive to credit market development. The study notes that in order for credit expansion to be successful, the credit received by a country must reflect positively on a country’s economic growth. In other words, with more credit coming into a country, the expected result is that there will also be a rise in economic growth. Furthermore, seeing that inflation erodes the value of money, this credit or these funds that a country receives may not have the expected influence on growth. Therefore, the study finds it imperative to investigate the levels at which inflation allows for credit expansion to promote growth in a country. Furthermore, central banks play an important role in credit markets via the interest rate channel and the study examines the role of monetary policy in credit markets of each of the BRICS countries by looking at the inflation targeting regime as well as the absence thereof within these countries. Moreover, BRICS central banks share more or less the same goal of maintaining price stability and low inflation through various monetary policy tools. Therefore, achieving this objective will allow a central bank to gain both investor and consumer confidence which plays a role in a country’s investment rates. Moreover, inflation that is not controlled results in uncertainty which makes investors hesitant and unwilling to embark on investments. Ha, Ivanova, Ohnsorge and Unsal (2019) associate a developed financial sector with low inflation, stating that stable inflation rates eliminate uncertainty and avoids the erosion of the value of money. The current study used an Autoregressive Distributed Lag (ARDL) model to examine the linear co-integration and Non-linear Autoregressive Distributed Lag (NARDL) for the non-linear empirical analysis of the relationship between inflation, credit markets and economic growth in BRICS countries. The non-linearity of this relationship is important to study as there has been many debates on the nature of the inflation-growth relationships with some studies implying that it is positive, some say it is a negative relationship and some say it is non-linear. The annual data time series is extracted from the World Bank Indicators and the Penn State database covering the period 1960-2019. The main variables used in the study are Inflation (CPI), Credit (Domestic Credit to Private Sector) and Economic growth (GDP). The study conducted various regressions including the total of five linear regressions which were run individually for each country, the non-linear regressions consisted of three regressions for each country which were on 1) Only Inflation partitioned, (2) Only Credit partitioned and (3) both Inflation and Credit were partitioned. The partitioning of the variables is made possible by the NARDL model which allows variables to be partially decomposed into negative and positive sums to identify thresholds of variables which have various effects on other variables. The overall findings of the study suggest that although inflation exerts various effects on growth, according to this study’s results, it does not have a significant impact on credit for all the countries except for China whereby credit in general is conducive to economic growth and Brazil where growth is enhanced when credit is declining. The study revealed that generally, inflation exerts a negative impact on growth, therefore, authorities must focus on keeping inflation rates low particularly for Russia, India and South Africa as Brazil’s results suggest that rising inflation is conducive to its economic growth in the long run. According to the findings of this study, credit does not have the significant impact on growth even under different inflation thresholds. Furthermore, this does not imply that the credit channel is a futile tool for authorities, the relationship between inflation, credit and growth particularly with the hypothesis that inflation enhances credit market development and therefore growth, is not significant. , Thesis (MCom) -- Faculty of Business and Economic Sciences, School of Economics, Development & Tourism, 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Barayi, Bavuyile
- Date: 2021-12
- Subjects: Economic development -- BRIC countries , Inflation (Finance) -- BRIC countries
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53700 , vital:45714
- Description: The empirical study investigates the relationship between inflation, credit markets and economic growth in the context of Brazil, Russia, India, China and South Africa (BRICS) countries. The BRICS group consists of five emerging market economies and was first coined by Jim O’Neil of Goldman Sachs in 2001 whereby initially the bloc consisted of only Brazil, Russia, India, China, South Africa joined the BRICS group in 2010. The BRICS bloc was deemed to be the top fast-growing economies that showed great potential for growth. Consequent to the 2008 global financial crisis, there has been a large change in economic thinking as policy-makers have struggled to overcome the economic misfortunes caused by the crisis. Amongst the emerging countries, the BRICS countries have in effect, established a New Development Bank to play the role of the credit facilitator the BRICS countries and other emerging countries as well. This BRICS New Development Bank was established in 2014 and already has identified and funded some projects within the BRICS countries. Moreover, the main objective of this bank is to provide credit to be utilised for infrastructure, climate change measures, as well as to ensure sustainable development. Against this backdrop, the current study investigates the role played by credit and the extent of development in credit markets on enhancing growth in the BRICS countries, particularly looking at the levels of inflation that are conducive to credit market development. The study notes that in order for credit expansion to be successful, the credit received by a country must reflect positively on a country’s economic growth. In other words, with more credit coming into a country, the expected result is that there will also be a rise in economic growth. Furthermore, seeing that inflation erodes the value of money, this credit or these funds that a country receives may not have the expected influence on growth. Therefore, the study finds it imperative to investigate the levels at which inflation allows for credit expansion to promote growth in a country. Furthermore, central banks play an important role in credit markets via the interest rate channel and the study examines the role of monetary policy in credit markets of each of the BRICS countries by looking at the inflation targeting regime as well as the absence thereof within these countries. Moreover, BRICS central banks share more or less the same goal of maintaining price stability and low inflation through various monetary policy tools. Therefore, achieving this objective will allow a central bank to gain both investor and consumer confidence which plays a role in a country’s investment rates. Moreover, inflation that is not controlled results in uncertainty which makes investors hesitant and unwilling to embark on investments. Ha, Ivanova, Ohnsorge and Unsal (2019) associate a developed financial sector with low inflation, stating that stable inflation rates eliminate uncertainty and avoids the erosion of the value of money. The current study used an Autoregressive Distributed Lag (ARDL) model to examine the linear co-integration and Non-linear Autoregressive Distributed Lag (NARDL) for the non-linear empirical analysis of the relationship between inflation, credit markets and economic growth in BRICS countries. The non-linearity of this relationship is important to study as there has been many debates on the nature of the inflation-growth relationships with some studies implying that it is positive, some say it is a negative relationship and some say it is non-linear. The annual data time series is extracted from the World Bank Indicators and the Penn State database covering the period 1960-2019. The main variables used in the study are Inflation (CPI), Credit (Domestic Credit to Private Sector) and Economic growth (GDP). The study conducted various regressions including the total of five linear regressions which were run individually for each country, the non-linear regressions consisted of three regressions for each country which were on 1) Only Inflation partitioned, (2) Only Credit partitioned and (3) both Inflation and Credit were partitioned. The partitioning of the variables is made possible by the NARDL model which allows variables to be partially decomposed into negative and positive sums to identify thresholds of variables which have various effects on other variables. The overall findings of the study suggest that although inflation exerts various effects on growth, according to this study’s results, it does not have a significant impact on credit for all the countries except for China whereby credit in general is conducive to economic growth and Brazil where growth is enhanced when credit is declining. The study revealed that generally, inflation exerts a negative impact on growth, therefore, authorities must focus on keeping inflation rates low particularly for Russia, India and South Africa as Brazil’s results suggest that rising inflation is conducive to its economic growth in the long run. According to the findings of this study, credit does not have the significant impact on growth even under different inflation thresholds. Furthermore, this does not imply that the credit channel is a futile tool for authorities, the relationship between inflation, credit and growth particularly with the hypothesis that inflation enhances credit market development and therefore growth, is not significant. , Thesis (MCom) -- Faculty of Business and Economic Sciences, School of Economics, Development & Tourism, 2021
- Full Text:
- Date Issued: 2021-12
Access to digitised archival collections in National Heritage and Cultural study Centre and International Library of African Music
- Authors: Barbra, Kakumba
- Date: 2021-04
- Subjects: Archives--Access control , Archival materials -- Access control
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22356 , vital:52030
- Description: The study investigated access to digitised archival collections in two selected institutions in the Eastern Cape Province, South Africa. This study is significant because it sought to generate insights on adaptability of technology in archives and library operations, and accessibility thereof. This is important for monitoring the accessibility of digitised archival collections at institutions to improve their operations and maximize the global visibility. This study adopted qualitative research methodology. The researcher followed a rigorous methodological path that began with a thorough literature review and the careful and thoughtful posing of research questions and objectives. A purposive sample was chosen from National Heritage and Cultural Studies Centre (NAHECS) and International library of African Music (ILAM) (staff members) and interviewed through face-to-face interviews. The collected data was analysed thematically. The study established that, the type of materials digitised at NAHECS and ILAM are bound books, fragile papers, photographic prints, slides, audio-visual materials,artefacts and documents such as personal letters of early travellers,missionary’s records,traders writing personal file and political parties documents. Secondly, the study established that end users of digitised materials are researchers, students, archivist, librarians, international and local community, composers, musicians, and historians. It also emerged that awareness programmes used to increase public knowledge about access to digitised content in the two study sites include conferences, social media, and television advertisements. However, there are challenges faced in providing access to digitised materials at NAHECS and ILAM. Some of these challenges include lack of funding, unavailability of resources, lack of awareness, and information insecurity. These challenges have made access to digitised archival materials difficult. Based on these findings, it is recommended that archives facilities should be well resourced and archivists be continually trained on access to digitised archival materials. , Thesis (M Bibl) -- Faculty of Social Sciences and Humanities, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Barbra, Kakumba
- Date: 2021-04
- Subjects: Archives--Access control , Archival materials -- Access control
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22356 , vital:52030
- Description: The study investigated access to digitised archival collections in two selected institutions in the Eastern Cape Province, South Africa. This study is significant because it sought to generate insights on adaptability of technology in archives and library operations, and accessibility thereof. This is important for monitoring the accessibility of digitised archival collections at institutions to improve their operations and maximize the global visibility. This study adopted qualitative research methodology. The researcher followed a rigorous methodological path that began with a thorough literature review and the careful and thoughtful posing of research questions and objectives. A purposive sample was chosen from National Heritage and Cultural Studies Centre (NAHECS) and International library of African Music (ILAM) (staff members) and interviewed through face-to-face interviews. The collected data was analysed thematically. The study established that, the type of materials digitised at NAHECS and ILAM are bound books, fragile papers, photographic prints, slides, audio-visual materials,artefacts and documents such as personal letters of early travellers,missionary’s records,traders writing personal file and political parties documents. Secondly, the study established that end users of digitised materials are researchers, students, archivist, librarians, international and local community, composers, musicians, and historians. It also emerged that awareness programmes used to increase public knowledge about access to digitised content in the two study sites include conferences, social media, and television advertisements. However, there are challenges faced in providing access to digitised materials at NAHECS and ILAM. Some of these challenges include lack of funding, unavailability of resources, lack of awareness, and information insecurity. These challenges have made access to digitised archival materials difficult. Based on these findings, it is recommended that archives facilities should be well resourced and archivists be continually trained on access to digitised archival materials. , Thesis (M Bibl) -- Faculty of Social Sciences and Humanities, 2021
- Full Text:
- Date Issued: 2021-04
Phylogeography and reproductive isolation of the brown mussel, Perna perna, on the South African coastline
- Authors: Barker, Cassandra
- Date: 2021-10
- Subjects: Mexilhao mussel South Africa , Phylogeography South Africa , Mexilhao mussel Reproduction , Mexilhao mussel Genetics , Intertidal organisms South Africa , Mexilhao mussel Climatic factors South Africa , Cytochrome oxidase , Mitochondrial DNA , Haplotype network
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190041 , vital:44958
- Description: Maintenance of a species’ abundance and adaptive potential is partially dependent on its genetic diversity. Distinct genetic lineages within a species can differ significantly in their resistance and resilience to environmental pressure. An assessment of such differences is key to grasp the adaptive potential of a species. Physical environmental conditions are significant determinants of the distribution of species and their genetic lineages. Under climate change scenarios, the assessment of the temporal stability of the spatial distribution of genetic structure has important consequences for conservation as it offers key insights into the adaptive potential and evolutionary capacity of a species. This thesis investigated the phylogeography and reproductive isolation of Perna perna, the brown mussel. This species is an ecologically and economically important intertidal mussel on South Africa’s coastline. It was determined in 2007 that there were two distinct genetic lineages of P. perna present on South Africa’s coastline, the Eastern and Western lineage. This thesis compared mitochondrial DNA between samples collected in 2007 and samples collected in 2019 to determine differences in genetic structure of P. perna over time. This thesis further investigated the reproductive timing of the two lineages to determine if this contributes to the maintenance of the genetic structure of this species. The results show that there is a shift in the distribution of the Eastern lineage since 2007, an increase in the range of the overlap region, and there was a change in genetic diversity in the form of private haplotypes between 2007 and 2019. The lineages have unsynchronised spawning and reproductive patterns are more closely linked to changes in temperature. While the lineages have shown slight distributional changes over time, the influence of environmental conditions and the predicted changes in sea surface temperatures could see a change in future populations’ fitness and dispersal. Thus, changes in sea surface temperature could affect reproductive timing and the future genetic stability of the species. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2021
- Full Text:
- Date Issued: 2021-10
- Authors: Barker, Cassandra
- Date: 2021-10
- Subjects: Mexilhao mussel South Africa , Phylogeography South Africa , Mexilhao mussel Reproduction , Mexilhao mussel Genetics , Intertidal organisms South Africa , Mexilhao mussel Climatic factors South Africa , Cytochrome oxidase , Mitochondrial DNA , Haplotype network
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190041 , vital:44958
- Description: Maintenance of a species’ abundance and adaptive potential is partially dependent on its genetic diversity. Distinct genetic lineages within a species can differ significantly in their resistance and resilience to environmental pressure. An assessment of such differences is key to grasp the adaptive potential of a species. Physical environmental conditions are significant determinants of the distribution of species and their genetic lineages. Under climate change scenarios, the assessment of the temporal stability of the spatial distribution of genetic structure has important consequences for conservation as it offers key insights into the adaptive potential and evolutionary capacity of a species. This thesis investigated the phylogeography and reproductive isolation of Perna perna, the brown mussel. This species is an ecologically and economically important intertidal mussel on South Africa’s coastline. It was determined in 2007 that there were two distinct genetic lineages of P. perna present on South Africa’s coastline, the Eastern and Western lineage. This thesis compared mitochondrial DNA between samples collected in 2007 and samples collected in 2019 to determine differences in genetic structure of P. perna over time. This thesis further investigated the reproductive timing of the two lineages to determine if this contributes to the maintenance of the genetic structure of this species. The results show that there is a shift in the distribution of the Eastern lineage since 2007, an increase in the range of the overlap region, and there was a change in genetic diversity in the form of private haplotypes between 2007 and 2019. The lineages have unsynchronised spawning and reproductive patterns are more closely linked to changes in temperature. While the lineages have shown slight distributional changes over time, the influence of environmental conditions and the predicted changes in sea surface temperatures could see a change in future populations’ fitness and dispersal. Thus, changes in sea surface temperature could affect reproductive timing and the future genetic stability of the species. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2021
- Full Text:
- Date Issued: 2021-10
Coaches perspective on the positional demands of school boy (u18/u19) rugby players during a 70-minute match
- Authors: Barnard, Devon Vernon
- Date: 2021-10
- Subjects: Rugby football coaches South Africa , Rugby Union football players South Africa , Rugby football injuries South Africa , School sports South Africa , School sports Coaching South Africa , School sports Physiological aspects
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190089 , vital:44962
- Description: INTRODUCTION: Rugby union has been one of the team sports that has grown over the last few years, and the margin between success and failure for teams has become narrower as the years have gone by. The game consists of players going through different movements such as sprints and/or collisions, that vary in intensity. The demands that face schoolboy rugby players are not well understood, and the lack of research in this area leads to a potential lack of understanding of the perceptions that coaches have about the demands that schoolboys are faced with during a match. OBJECTIVE: Therefore, the purpose of this study was to determine the perceptions that the schoolboy rugby coaches had surrounding the demands that their players are faced with during a 70-minute match. There were a few secondary purposes of the study, such as determining which school, government or private, had a better understanding or perception of the demands, as well as comparing strength and conditioning coaches’ perceptions to regular coaches’ perceptions. METHODS: This was a cross-sectional, descriptive study to determine the coach’s perceptions. These perceptions were collected through an online questionnaire, which consisted of ten sections and 74 questions. The questionnaire was piloted on a subject group with different types of experience. Coaches from the top 100 schools list were contacted through their school website. RESULTS: The questionnaire had a 72% response rate: 41 responses from 51 emails. The 41 responses consisted of 23 government schools and 18 private schools, which included 11 of the top 20 rugby schools in South Africa, with most responses coming from the Eastern Cape (41.5%). Results indicated that a government school’s coaches had significantly (p<0.05) more experience than private schools’ coaches, and that they had significantly (p<0.05) better academic qualifications than private schools. However, strength and conditioning coaches had significantly (p<0.01) better academic qualifications than coach, whereas coaches had significantly (p<0.01) better coaching qualifications than strength and conditioning coaches. CONCLUSION: “Experience has been shown to be a potential reason for what is described as a good coach”. This is also another potential reason why government schools are a dominant force in schoolboy rugby in South Africa. However, this is also coupled with better qualifications showing the dual importance of both experience and education. This study has shown that coaches, within a South African cohort, overall had good general perception of the demands of school level rugby matches. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2021
- Full Text:
- Date Issued: 2021-10
- Authors: Barnard, Devon Vernon
- Date: 2021-10
- Subjects: Rugby football coaches South Africa , Rugby Union football players South Africa , Rugby football injuries South Africa , School sports South Africa , School sports Coaching South Africa , School sports Physiological aspects
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190089 , vital:44962
- Description: INTRODUCTION: Rugby union has been one of the team sports that has grown over the last few years, and the margin between success and failure for teams has become narrower as the years have gone by. The game consists of players going through different movements such as sprints and/or collisions, that vary in intensity. The demands that face schoolboy rugby players are not well understood, and the lack of research in this area leads to a potential lack of understanding of the perceptions that coaches have about the demands that schoolboys are faced with during a match. OBJECTIVE: Therefore, the purpose of this study was to determine the perceptions that the schoolboy rugby coaches had surrounding the demands that their players are faced with during a 70-minute match. There were a few secondary purposes of the study, such as determining which school, government or private, had a better understanding or perception of the demands, as well as comparing strength and conditioning coaches’ perceptions to regular coaches’ perceptions. METHODS: This was a cross-sectional, descriptive study to determine the coach’s perceptions. These perceptions were collected through an online questionnaire, which consisted of ten sections and 74 questions. The questionnaire was piloted on a subject group with different types of experience. Coaches from the top 100 schools list were contacted through their school website. RESULTS: The questionnaire had a 72% response rate: 41 responses from 51 emails. The 41 responses consisted of 23 government schools and 18 private schools, which included 11 of the top 20 rugby schools in South Africa, with most responses coming from the Eastern Cape (41.5%). Results indicated that a government school’s coaches had significantly (p<0.05) more experience than private schools’ coaches, and that they had significantly (p<0.05) better academic qualifications than private schools. However, strength and conditioning coaches had significantly (p<0.01) better academic qualifications than coach, whereas coaches had significantly (p<0.01) better coaching qualifications than strength and conditioning coaches. CONCLUSION: “Experience has been shown to be a potential reason for what is described as a good coach”. This is also another potential reason why government schools are a dominant force in schoolboy rugby in South Africa. However, this is also coupled with better qualifications showing the dual importance of both experience and education. This study has shown that coaches, within a South African cohort, overall had good general perception of the demands of school level rugby matches. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2021
- Full Text:
- Date Issued: 2021-10
Caregivers’ Knowledge, Attitude and Practices (KAP) of breastfeeding and prevention of mother-to-child transmission (pmtct) in Nelson Mandela Bay Health District: impact of a community dialogue intervention
- Authors: Barnard, Marné
- Date: 2021-04
- Subjects: Breastfeeding -- Transmission -- South Africa -- Nelson Mandela Bay Municipality -- Prevention , Communicable diseases -- South Africa -- Nelson Mandela Bay Municipality -- Prevention
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/50988 , vital:43196
- Description: Background: Globally, childhood mortality remains high with 5.3 million deaths occurring in children under the age of five years in 2018. Of these deaths, 43 000 were children from South Africa, with malnutrition being a significant risk factor contributing to disease and death. Breastfeeding has many benefits and reduces childhood mortality. Current primary health care strategies in South Africa are not having an adequate impact on breastfeeding rates, therefore appropriate messages need to be targeted at the community in order to improve breastfeeding rates. Participatory approaches have been identified as an effective tool to promote child health. Community dialogues led by skilled Early Childhood Development (ECD) mentors from the community might be key in order to improve caregivers’ knowledge, attitudes and practices (KAP) in relation to breastfeeding and Prevention of Mother to Child Transmission of HIV (PMTCT). Aim : The aim of the study was to explore the potential effects of community dialogues, led by ECD mentors, on caregivers’ knowledge, attitudes and practices (KAP) in relation to breastfeeding and prevention of mother-to-child transmission of HIV (PMTCT). Methods: Quasi-experimental design was used to compare the KAP of caregivers in relation to breastfeeding and PMTCT. Convenience sampling was used to include 63 caregivers who participated in the umbrella project (mixed-methods) and 61 caregivers who did not participate in the project. Ethics approval was obtained from the Nelson Mandela University Faculty Postgraduate Studies Committee. Participants had to provide written informed consent. A skilled interviewer used a structured questionnaire to assess the KAP of all participants. Data were captured on an Excel spreadsheet and analysed in collaboration with a statistician, who analysed the data using Microsoft Excel. Descriptive statistics were applied to numerical data, while frequency distributions were applied to categorical data. Correlations were calculated to describe the degree of relationship between two variables. Inferential statistic tests, conducted at a significance level of 0,05, were used for hypothesis testing. The t-test and analysis of variance (ANOVA) were used in tests involving mean values. Scheffé’s test was used in ANOVA to determine between which of the groups a statistically significant difference was found. Results: In the intervention group more than double the number participants (35%; n=22) had a good knowledge of breastfeeding when compared to participants (15%; n=9) in the control group. Additionally, the intervention group participants displayed better attitudes towards the RtHB (p=0.02). However, control group participants showed better knowledge towards the HIV (p=0.01). Finally, results suggest that in the intervention group, participants (33%; n=21) were more likely to have a good total KAP score in relation to breastfeeding and PMTCT when compared to participants (11%; n=7) in the control group. In the intervention group, better knowledge correlated with good practices relating to the RtHB (r=0.27). However, in the control group, positive attitudes correlated with better practices relating to HIV (r=0.29). Younger intervention group participants displayed better breastfeeding related practices (p=0.011). Additionally, younger control group participants displayed better knowledge of breastfeeding (p=0.001). Intervention group participants whose choices were influenced by their husband/ partner (p =0.016) and/ or radio/ magazines/ newspapers (p=0.004) had positive attitudes towards HIV. Control group participants whose choices were influenced by their other family members (p=0.043) and/ or clinic staff (p=0.016) had good knowledge of sharing their knowledge. Conclusions and recommendations: The intervention group displayed a better knowledge of breastfeeding as well as more desirable attitudes towards the RtHB, when compared to the control group. However, the control group displayed better knowledge of HIV, which could be due to the control group having more younger participants when compared to the intervention group. The community dialogue intervention had a positive impact on caregivers KAP relating to breastfeeding and PMTCT, which included all the different categories combined. In order to improve the Sakha Esethu intervention programme, managers need to provide guidance to the mentors on how to initiate conversations regarding HIV and discuss the stigma associated with HIV and breastfeeding. Results showed that including grandmothers and husbands or partners in the target population will benefit the intervention. Additionally, the use of radio needs to be considered especially for discussions regarding HIV. Lastly, sustainability needs to be improved due to many participants not remembering certain detail regarding topics that was discussed. , Thesis (MSc) -- Faculty of Health Sciences, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Barnard, Marné
- Date: 2021-04
- Subjects: Breastfeeding -- Transmission -- South Africa -- Nelson Mandela Bay Municipality -- Prevention , Communicable diseases -- South Africa -- Nelson Mandela Bay Municipality -- Prevention
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/50988 , vital:43196
- Description: Background: Globally, childhood mortality remains high with 5.3 million deaths occurring in children under the age of five years in 2018. Of these deaths, 43 000 were children from South Africa, with malnutrition being a significant risk factor contributing to disease and death. Breastfeeding has many benefits and reduces childhood mortality. Current primary health care strategies in South Africa are not having an adequate impact on breastfeeding rates, therefore appropriate messages need to be targeted at the community in order to improve breastfeeding rates. Participatory approaches have been identified as an effective tool to promote child health. Community dialogues led by skilled Early Childhood Development (ECD) mentors from the community might be key in order to improve caregivers’ knowledge, attitudes and practices (KAP) in relation to breastfeeding and Prevention of Mother to Child Transmission of HIV (PMTCT). Aim : The aim of the study was to explore the potential effects of community dialogues, led by ECD mentors, on caregivers’ knowledge, attitudes and practices (KAP) in relation to breastfeeding and prevention of mother-to-child transmission of HIV (PMTCT). Methods: Quasi-experimental design was used to compare the KAP of caregivers in relation to breastfeeding and PMTCT. Convenience sampling was used to include 63 caregivers who participated in the umbrella project (mixed-methods) and 61 caregivers who did not participate in the project. Ethics approval was obtained from the Nelson Mandela University Faculty Postgraduate Studies Committee. Participants had to provide written informed consent. A skilled interviewer used a structured questionnaire to assess the KAP of all participants. Data were captured on an Excel spreadsheet and analysed in collaboration with a statistician, who analysed the data using Microsoft Excel. Descriptive statistics were applied to numerical data, while frequency distributions were applied to categorical data. Correlations were calculated to describe the degree of relationship between two variables. Inferential statistic tests, conducted at a significance level of 0,05, were used for hypothesis testing. The t-test and analysis of variance (ANOVA) were used in tests involving mean values. Scheffé’s test was used in ANOVA to determine between which of the groups a statistically significant difference was found. Results: In the intervention group more than double the number participants (35%; n=22) had a good knowledge of breastfeeding when compared to participants (15%; n=9) in the control group. Additionally, the intervention group participants displayed better attitudes towards the RtHB (p=0.02). However, control group participants showed better knowledge towards the HIV (p=0.01). Finally, results suggest that in the intervention group, participants (33%; n=21) were more likely to have a good total KAP score in relation to breastfeeding and PMTCT when compared to participants (11%; n=7) in the control group. In the intervention group, better knowledge correlated with good practices relating to the RtHB (r=0.27). However, in the control group, positive attitudes correlated with better practices relating to HIV (r=0.29). Younger intervention group participants displayed better breastfeeding related practices (p=0.011). Additionally, younger control group participants displayed better knowledge of breastfeeding (p=0.001). Intervention group participants whose choices were influenced by their husband/ partner (p =0.016) and/ or radio/ magazines/ newspapers (p=0.004) had positive attitudes towards HIV. Control group participants whose choices were influenced by their other family members (p=0.043) and/ or clinic staff (p=0.016) had good knowledge of sharing their knowledge. Conclusions and recommendations: The intervention group displayed a better knowledge of breastfeeding as well as more desirable attitudes towards the RtHB, when compared to the control group. However, the control group displayed better knowledge of HIV, which could be due to the control group having more younger participants when compared to the intervention group. The community dialogue intervention had a positive impact on caregivers KAP relating to breastfeeding and PMTCT, which included all the different categories combined. In order to improve the Sakha Esethu intervention programme, managers need to provide guidance to the mentors on how to initiate conversations regarding HIV and discuss the stigma associated with HIV and breastfeeding. Results showed that including grandmothers and husbands or partners in the target population will benefit the intervention. Additionally, the use of radio needs to be considered especially for discussions regarding HIV. Lastly, sustainability needs to be improved due to many participants not remembering certain detail regarding topics that was discussed. , Thesis (MSc) -- Faculty of Health Sciences, 2021
- Full Text:
- Date Issued: 2021-04
Perceptions of blended learning by academic staff in the Health Sciences Faculty at Nelson Mandela University
- Authors: Barry, Janet
- Date: 2021-04
- Subjects: Blended learning -- South Africa -- Nelson Mandela Bay Municipality -- Faculty , Medical sciences -- South Africa -- Nelson Mandela Bay Municipality -- Faculty
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/50999 , vital:43199
- Description: Numerous studies have investigated the use of blended learning by academic staff at tertiary institutions. The purpose of this study was to examine the perceptions of blended learning by academic staff at the Faculty of Health Sciences at Nelson Mandela University. A related objective was to identify barriers and facilitators to the adoption of blended learning by academic staff. A sequential, exploratory mixed-methods design was adopted for this study whereby Phase 1 (focus groups) was used to inform Phase 2 (questionnaire) of the study. Results were analysed from both phases and organised according to strategies, support, and structure of a blended learning adoption framework. Existing support structures to assist with blended learning adoption, understanding of what blended learning is, confidence in using blended learning tools, and time to attend training were some of the findings of the study. The researcher concluded that academic staff in the Health Sciences Faculty at Nelson Mandela University are positioned in the second stage of the blended learning adoption framework, namely the early adoption stage of blended learning. These findings imply that existing strategies and support within the Faculty and the University need to be further developed, and structures put into place to move to an advanced stage of adoption of blended learning by academic staff in Health Sciences Faculty of Nelson Mandela University. , Thesis (MPharm) -- Faculty of Health Sciences, Pharmacy, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Barry, Janet
- Date: 2021-04
- Subjects: Blended learning -- South Africa -- Nelson Mandela Bay Municipality -- Faculty , Medical sciences -- South Africa -- Nelson Mandela Bay Municipality -- Faculty
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/50999 , vital:43199
- Description: Numerous studies have investigated the use of blended learning by academic staff at tertiary institutions. The purpose of this study was to examine the perceptions of blended learning by academic staff at the Faculty of Health Sciences at Nelson Mandela University. A related objective was to identify barriers and facilitators to the adoption of blended learning by academic staff. A sequential, exploratory mixed-methods design was adopted for this study whereby Phase 1 (focus groups) was used to inform Phase 2 (questionnaire) of the study. Results were analysed from both phases and organised according to strategies, support, and structure of a blended learning adoption framework. Existing support structures to assist with blended learning adoption, understanding of what blended learning is, confidence in using blended learning tools, and time to attend training were some of the findings of the study. The researcher concluded that academic staff in the Health Sciences Faculty at Nelson Mandela University are positioned in the second stage of the blended learning adoption framework, namely the early adoption stage of blended learning. These findings imply that existing strategies and support within the Faculty and the University need to be further developed, and structures put into place to move to an advanced stage of adoption of blended learning by academic staff in Health Sciences Faculty of Nelson Mandela University. , Thesis (MPharm) -- Faculty of Health Sciences, Pharmacy, 2021
- Full Text:
- Date Issued: 2021-04
An investigation of alternative separation strategies for common chemical mixtures by means of host-guest chemistry protocols with host compounds N,N′- bis(5-phenyl-5-dibenzo[a,d]cycloheptenyl)ethylenediamine and N,N’-bis(5-phenyl-10,11- dihydro-5-dibenzo[a,d]cycloheptenyl)ethylenediamine
- Authors: Barton, Danica Brione
- Date: 2023-04
- Subjects: Ethylenediaminetetraacetic acid -- South Africa , Enzymes –Analysis
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/61176 , vital:69791
- Description: In this work, the selectivity behaviour of two host compounds, namely N,N’-bis(5-phenyl-5- ibenzo[a,d]cycloheptenyl)ethylenediamine (H1) and N,N’-bis(5-phenyl-10,11-dihydro-5- ibenzo[a,d]cycloheptenyl)ethylenediamine (H2), was assessed in mixtures of difficult-toseparate compounds, including the xylenes and ethylbenzene, pyridine and methylpyridines, and anisole and methylanisoles. These host compounds were synthesized using Grignard addition reactions with phenylmagnesium bromide on dibenzo[a,d]cyclohepten-5-one and 10,11- dihydrodibenzo[a,d]cyclohepten-5-one, respectively. The resultant alcohols were treated with perchloric acid to form the corresponding perchlorate salts, which were then reacted with ethylenediamine to afford the required H1 and H2 host compounds. Yields were 95 ad 52% for this final step in each case. An investigation of the conformations, both from experiment (using single crystal X-ray diffractometry (SCXRD) on the apohost compound) and computational calculations was undertaken. Unfortunately, H1 always crystallized out as a powder unless this host compound formed a complex with a guest species, and so could not be subjected to SCXRD analysis as apohost alone. However, a single crystal structure for apohost H2 was successfully obtained and compared with computational data from a previous investigation. It was observed that the conformation of apohost H2 compared favourably with that of the lowest energy conformer from that work. In single solvent recrystallization experiments with o-, m-, p-xylene (o-Xy, m-Xy, p-Xy) and ethylbenzene (EB), both H1 and H2 formed complexes with only one of the four guest species, namely p-Xy and o-Xy, respectively. The host:guest (H:G) ratios were 1:1 for both of these complexes. In the equimolar guest/guest competition experiments, inclusion complexes only formed when p-Xy or o-Xy, respectively, were present in the mixtures; if p-Xy (for experiments with H1) or o-Xy (H2) was absent from these mixtures, only apohost was recovered from the glass vessels. Three selectivity profiles were constructed for each of these host compounds, in which each one was recrystallized from binary mixed guests in various proportions. These demonstrated an overwhelming preference of H1 for p-Xy and H2 for o-Xy, which concurred with the results from the equimolar experiments. Thermal analysis using H1∙p-Xy revealed that this complex was unstable at ambient conditions, while SCXRD explained this observation: this complex may be defined as a true clathrate since no host‧‧‧guest interactions were identified at all, and the guest was retained in the complex by means of steric factors alone. Furthermore, the guest molecules resided in wide open channels that may have facilitated the guest release process. H2∙o-Xy, on the other hand, was stable at room temperature, and the guest release event only commenced at 69.7 °C (Ton). This too was explained by SCXRD analyses in that interactions between host and guest species were observed in this case. Additionally, the guest molecules were housed in discrete cages, which made their escape more challenging compared with p-Xy in H1∙p-Xy. It was concluded that, in this guest series, both of the host compounds would be effective as separatory tools employing host-guest chemistry protocols due to their remarkable selectivities for p-Xy (H1) and o-Xy (H2). , Thesis (MSc) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2023
- Full Text:
- Date Issued: 2023-04
- Authors: Barton, Danica Brione
- Date: 2023-04
- Subjects: Ethylenediaminetetraacetic acid -- South Africa , Enzymes –Analysis
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/61176 , vital:69791
- Description: In this work, the selectivity behaviour of two host compounds, namely N,N’-bis(5-phenyl-5- ibenzo[a,d]cycloheptenyl)ethylenediamine (H1) and N,N’-bis(5-phenyl-10,11-dihydro-5- ibenzo[a,d]cycloheptenyl)ethylenediamine (H2), was assessed in mixtures of difficult-toseparate compounds, including the xylenes and ethylbenzene, pyridine and methylpyridines, and anisole and methylanisoles. These host compounds were synthesized using Grignard addition reactions with phenylmagnesium bromide on dibenzo[a,d]cyclohepten-5-one and 10,11- dihydrodibenzo[a,d]cyclohepten-5-one, respectively. The resultant alcohols were treated with perchloric acid to form the corresponding perchlorate salts, which were then reacted with ethylenediamine to afford the required H1 and H2 host compounds. Yields were 95 ad 52% for this final step in each case. An investigation of the conformations, both from experiment (using single crystal X-ray diffractometry (SCXRD) on the apohost compound) and computational calculations was undertaken. Unfortunately, H1 always crystallized out as a powder unless this host compound formed a complex with a guest species, and so could not be subjected to SCXRD analysis as apohost alone. However, a single crystal structure for apohost H2 was successfully obtained and compared with computational data from a previous investigation. It was observed that the conformation of apohost H2 compared favourably with that of the lowest energy conformer from that work. In single solvent recrystallization experiments with o-, m-, p-xylene (o-Xy, m-Xy, p-Xy) and ethylbenzene (EB), both H1 and H2 formed complexes with only one of the four guest species, namely p-Xy and o-Xy, respectively. The host:guest (H:G) ratios were 1:1 for both of these complexes. In the equimolar guest/guest competition experiments, inclusion complexes only formed when p-Xy or o-Xy, respectively, were present in the mixtures; if p-Xy (for experiments with H1) or o-Xy (H2) was absent from these mixtures, only apohost was recovered from the glass vessels. Three selectivity profiles were constructed for each of these host compounds, in which each one was recrystallized from binary mixed guests in various proportions. These demonstrated an overwhelming preference of H1 for p-Xy and H2 for o-Xy, which concurred with the results from the equimolar experiments. Thermal analysis using H1∙p-Xy revealed that this complex was unstable at ambient conditions, while SCXRD explained this observation: this complex may be defined as a true clathrate since no host‧‧‧guest interactions were identified at all, and the guest was retained in the complex by means of steric factors alone. Furthermore, the guest molecules resided in wide open channels that may have facilitated the guest release process. H2∙o-Xy, on the other hand, was stable at room temperature, and the guest release event only commenced at 69.7 °C (Ton). This too was explained by SCXRD analyses in that interactions between host and guest species were observed in this case. Additionally, the guest molecules were housed in discrete cages, which made their escape more challenging compared with p-Xy in H1∙p-Xy. It was concluded that, in this guest series, both of the host compounds would be effective as separatory tools employing host-guest chemistry protocols due to their remarkable selectivities for p-Xy (H1) and o-Xy (H2). , Thesis (MSc) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2023
- Full Text:
- Date Issued: 2023-04
Modification of Gelatin-Methacrylate, Hyaluronic-Methacrylate and Poly(ethylene) glycol Diacrylate hydrogel bioinks towards the additive manufacturing of articular cartilage
- Authors: Barwick, Matthew William
- Date: 2021-10
- Subjects: Cartilage Diseases , Cartilage Regeneration , Articular cartilage Diseases , Chondrogenesis , Stem cells , Scanning electron microscopy , Fourier transform infrared spectroscopy , Three-dimensional printing , Gelatin-Methacrylate , Hyaluronic-Methacrylate , Poly(ethylene) glycolDiacrylate , Hydrogel bioinks , Real-Time Quantitative Cell Analysis (RTCA) , Bioprinting
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/191181 , vital:45068
- Description: Cartilage degradation is most commonly associated with Rheumatoid arthritis and Osteoarthritis, affecting millions of people worldwide. Joint transplants commonly use titanium alloys, which have a shelf life of between 10-15 years. Although the titanium transplant restores partial mobility, side effects such as inflammation, swelling, faulty implants, and metal poisoning in some cases resulting from the transplant. The use of additive manufacturing of articular cartilage sheds new, innovative prospects for joint replacements. This study sets out to formulate and characterize five different hydrogel types towards the additive manufacturing of articular cartilage. Chondrogenic and Adipogenic differentiation was carried out on two separate adipose-mesenchymal stem cell lines A270620-01A, and A311019-02T and validation and efficiency of the differentiation and chondrogenic gene expression was carried out using Alcian Blue stain, Oil Red O stain and Quantitative Reverse Transcription PCR (RT-qPCR). Hydrogel formulation and characterisation of 10 % Gelatin-methacryloyl (GelMA), 10 % Poly (ethylene) glycol diacrylate (PEGDA), 5 % GelMA/5 % PEGDA, 10 % GelMA/0.5 % Hyaluronic Acid Methacrylate (HAMA) and 10 % PEGDA/0.5 % HAMA was carried out through swelling and degradation ratios, surface area and porosity characterisation using Scanning Electron Microscopy (SEM). Hydrogel component and spectroscopic analysis were carried using Real-Time Quantitative Cell Analysis (RTCA) and Fourier-transform Infrared Spectroscopy (FTIR) analysis for each formulated hydrogel's chemical characterisation. Three-dimensional printing (3D) of 10 % PEGDA/0.5 % HAMA and 5 % GelMA/5 % PEGDA was performed using the Zortrax INKSPIRE Resin Ultra-Violet (UV) LCD Desktop 3D Printer. Hydrogel sterility and cell viability were carried out for each hydrogel type using fluorescence microscopy. Both A270620-01A and A311019-02T cell lines showed adipogenic and chondrogenic differentiation ability, with A311019-02T cell line showing greater chondrogenic differentiation of Alcian blue staining. The A270620-01A cell line resulted in a greater collagen gene expression based on the RT-qPCR results. The hydrogel 10 % GelMA showed the greatest swelling ratio of 1260 % in DPBS and 1192 % in DMEM. A significant difference between hydrogel swelling and swelling with Dulbecco's Phosphate Buffered Saline (DPBS) and Dulbecco’s Modified Eagle Medium (DMEM) was observed. The 10 % PEGDA hydrogel had the greatest degradation ratio of 59 % mass remaining, where the 10 % GelMA/0.5 % HAMA showed the least amount of degradation with a mass remaining at 91 %. The 10 % GelMA showed the greatest porosity will the largest pore size of 14 μm in diameter. Hydrogel component and spectroscopic analysis showed no cytotoxic effects for the visible light photoinitiator used to polymerize the hydrogel and no cytotoxic effects for the concentrations used in chondrogenic differentiation. The FTIR analysis showed partial gelatin and hyaluronic acid modification with methacrylic anhydride; however, the distinction between the hybrid hydrogels and single polymer hydrogels could not be made effectively. UV and ethanol washing showed to completely sterilise the hydrogel disks from any contaminants, making them suitable for tissue culture. The cell viability analysis showed the 10 % GelMA/HAMA having the highest cell viability of 77.3 % using 5000 cells/disk and 89.64 % viability using 50 000 cells/disk over a 7-day incubation period. Overall, the combination of two polymers, GelMA and HAMA, has good potential as a 3D hydrogel scaffold towards additive manufacturing of articular cartilage. , Thesis (MSc) -- Faculty of Science, Biotechnology Innovation Centre, 2021
- Full Text:
- Date Issued: 2021-10
- Authors: Barwick, Matthew William
- Date: 2021-10
- Subjects: Cartilage Diseases , Cartilage Regeneration , Articular cartilage Diseases , Chondrogenesis , Stem cells , Scanning electron microscopy , Fourier transform infrared spectroscopy , Three-dimensional printing , Gelatin-Methacrylate , Hyaluronic-Methacrylate , Poly(ethylene) glycolDiacrylate , Hydrogel bioinks , Real-Time Quantitative Cell Analysis (RTCA) , Bioprinting
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/191181 , vital:45068
- Description: Cartilage degradation is most commonly associated with Rheumatoid arthritis and Osteoarthritis, affecting millions of people worldwide. Joint transplants commonly use titanium alloys, which have a shelf life of between 10-15 years. Although the titanium transplant restores partial mobility, side effects such as inflammation, swelling, faulty implants, and metal poisoning in some cases resulting from the transplant. The use of additive manufacturing of articular cartilage sheds new, innovative prospects for joint replacements. This study sets out to formulate and characterize five different hydrogel types towards the additive manufacturing of articular cartilage. Chondrogenic and Adipogenic differentiation was carried out on two separate adipose-mesenchymal stem cell lines A270620-01A, and A311019-02T and validation and efficiency of the differentiation and chondrogenic gene expression was carried out using Alcian Blue stain, Oil Red O stain and Quantitative Reverse Transcription PCR (RT-qPCR). Hydrogel formulation and characterisation of 10 % Gelatin-methacryloyl (GelMA), 10 % Poly (ethylene) glycol diacrylate (PEGDA), 5 % GelMA/5 % PEGDA, 10 % GelMA/0.5 % Hyaluronic Acid Methacrylate (HAMA) and 10 % PEGDA/0.5 % HAMA was carried out through swelling and degradation ratios, surface area and porosity characterisation using Scanning Electron Microscopy (SEM). Hydrogel component and spectroscopic analysis were carried using Real-Time Quantitative Cell Analysis (RTCA) and Fourier-transform Infrared Spectroscopy (FTIR) analysis for each formulated hydrogel's chemical characterisation. Three-dimensional printing (3D) of 10 % PEGDA/0.5 % HAMA and 5 % GelMA/5 % PEGDA was performed using the Zortrax INKSPIRE Resin Ultra-Violet (UV) LCD Desktop 3D Printer. Hydrogel sterility and cell viability were carried out for each hydrogel type using fluorescence microscopy. Both A270620-01A and A311019-02T cell lines showed adipogenic and chondrogenic differentiation ability, with A311019-02T cell line showing greater chondrogenic differentiation of Alcian blue staining. The A270620-01A cell line resulted in a greater collagen gene expression based on the RT-qPCR results. The hydrogel 10 % GelMA showed the greatest swelling ratio of 1260 % in DPBS and 1192 % in DMEM. A significant difference between hydrogel swelling and swelling with Dulbecco's Phosphate Buffered Saline (DPBS) and Dulbecco’s Modified Eagle Medium (DMEM) was observed. The 10 % PEGDA hydrogel had the greatest degradation ratio of 59 % mass remaining, where the 10 % GelMA/0.5 % HAMA showed the least amount of degradation with a mass remaining at 91 %. The 10 % GelMA showed the greatest porosity will the largest pore size of 14 μm in diameter. Hydrogel component and spectroscopic analysis showed no cytotoxic effects for the visible light photoinitiator used to polymerize the hydrogel and no cytotoxic effects for the concentrations used in chondrogenic differentiation. The FTIR analysis showed partial gelatin and hyaluronic acid modification with methacrylic anhydride; however, the distinction between the hybrid hydrogels and single polymer hydrogels could not be made effectively. UV and ethanol washing showed to completely sterilise the hydrogel disks from any contaminants, making them suitable for tissue culture. The cell viability analysis showed the 10 % GelMA/HAMA having the highest cell viability of 77.3 % using 5000 cells/disk and 89.64 % viability using 50 000 cells/disk over a 7-day incubation period. Overall, the combination of two polymers, GelMA and HAMA, has good potential as a 3D hydrogel scaffold towards additive manufacturing of articular cartilage. , Thesis (MSc) -- Faculty of Science, Biotechnology Innovation Centre, 2021
- Full Text:
- Date Issued: 2021-10
Anti-oxidant and cytotoxicity activity against the HCC70 Breast cancer cell line of aqueous and methanolic extracts of two red algae species from the Eastern Cape Coast, South Africa
- Authors: Basera, Afra Tsitsi
- Date: 2021
- Subjects: Drug resistance in cancer cells , Oxidative stress
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22589 , vital:52586
- Description: Cancer, despite extensive research, remains one of the leading causes of mortality. Research into plant-derived compounds has gained traction, as some are not cytotoxic towards healthy cells and pose fewer side effects. Marine algae produce secondary metabolites, protecting them from oxidative stress, which causes cardiovascular diseases, cancer, and diabetes. Therefore, this study aimed to evaluate the anticancer potential of selected red algae species, collected from Humewood Beach, Gqeberha in South Africa, against HCC70 (human breast adenocarcinoma) cancer cells. Identification of the species was made through DNA barcoding of the rbcL gene. Methanolic and aqueous extracts of Gelidium pristoides and Laurencia natalensis were evaluated for antioxidant activity, phytochemical content, and anticancer potential. The phytochemical composition was determined using the phenol, flavonoid, flavonol, tannin, and proanthocyanidin content assays. Antioxidant potential was evaluated using the Ferric reducing antioxidant potential, Diphenyl-1- Picrylhydrazyl (DPPH), nitric oxide, 2, 2’-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging activity, and total antioxidant capacity (TAC) assays. The resazurin assay was used to determine the antiproliferative and cytotoxic activity of the methanolic extracts and solid-phase extraction fractions against the HCC70 breast cancer cells. The red algae species were identified as G. pristoides and L. natalensis. The aqueous extract of G. pristoides exhibited significantly higher phenols (24.0 mg/g GAE), tannins (31.6 mg/g TAE), and flavonols content (20.5 mg/g RE) than its methanolic extract, or the aqueous and methanolic extracts of L. natalensis. Methanolic extracts of G. pristoides and L. natalensis exhibited significantly higher proanthocyanidin contents (19.4 mg/g and 15.7 mg/g CE) than their respective aqueous extracts (13.0 mg/g and 11.8 mg/g CE). Flavonoids, however, were absent in both species. The aqueous and methanol extracts of Laurencia natalensis and Gelidium pristoides exhibited low inhibitory activities (less than 50%) against DPPH, ABTS, and nitric oxide radicals. Both species also showed low ferric reducing power. All the extracts were antiproliferative and cytotoxic against the HCC70 breast cancer cells, with L. natalensis exhibiting more significant inhibitory activity. However, its Solid Phase Extraction fractions did not display antiproliferative potential, unlike fraction 4 of G. pristoides. The study results suggest that both G. pristoides and L. natalensis possess bioactive compounds with potential anticancer activity. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021
- Authors: Basera, Afra Tsitsi
- Date: 2021
- Subjects: Drug resistance in cancer cells , Oxidative stress
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22589 , vital:52586
- Description: Cancer, despite extensive research, remains one of the leading causes of mortality. Research into plant-derived compounds has gained traction, as some are not cytotoxic towards healthy cells and pose fewer side effects. Marine algae produce secondary metabolites, protecting them from oxidative stress, which causes cardiovascular diseases, cancer, and diabetes. Therefore, this study aimed to evaluate the anticancer potential of selected red algae species, collected from Humewood Beach, Gqeberha in South Africa, against HCC70 (human breast adenocarcinoma) cancer cells. Identification of the species was made through DNA barcoding of the rbcL gene. Methanolic and aqueous extracts of Gelidium pristoides and Laurencia natalensis were evaluated for antioxidant activity, phytochemical content, and anticancer potential. The phytochemical composition was determined using the phenol, flavonoid, flavonol, tannin, and proanthocyanidin content assays. Antioxidant potential was evaluated using the Ferric reducing antioxidant potential, Diphenyl-1- Picrylhydrazyl (DPPH), nitric oxide, 2, 2’-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging activity, and total antioxidant capacity (TAC) assays. The resazurin assay was used to determine the antiproliferative and cytotoxic activity of the methanolic extracts and solid-phase extraction fractions against the HCC70 breast cancer cells. The red algae species were identified as G. pristoides and L. natalensis. The aqueous extract of G. pristoides exhibited significantly higher phenols (24.0 mg/g GAE), tannins (31.6 mg/g TAE), and flavonols content (20.5 mg/g RE) than its methanolic extract, or the aqueous and methanolic extracts of L. natalensis. Methanolic extracts of G. pristoides and L. natalensis exhibited significantly higher proanthocyanidin contents (19.4 mg/g and 15.7 mg/g CE) than their respective aqueous extracts (13.0 mg/g and 11.8 mg/g CE). Flavonoids, however, were absent in both species. The aqueous and methanol extracts of Laurencia natalensis and Gelidium pristoides exhibited low inhibitory activities (less than 50%) against DPPH, ABTS, and nitric oxide radicals. Both species also showed low ferric reducing power. All the extracts were antiproliferative and cytotoxic against the HCC70 breast cancer cells, with L. natalensis exhibiting more significant inhibitory activity. However, its Solid Phase Extraction fractions did not display antiproliferative potential, unlike fraction 4 of G. pristoides. The study results suggest that both G. pristoides and L. natalensis possess bioactive compounds with potential anticancer activity. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021
"Burnout" in children's home houseparents
- Authors: Bath, Peter John
- Date: 1983
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/193118 , vital:45300
- Description: Aimed at replicating the results of an American study into "Burnout" in Group Home houseparents, this research had the following aims: 1) To ascertain the validity and reliability of the instrument used in the original study and presented as a "useful measure of burnout”. 2) To establish whether this line of research, within a highly problematic research field, can at present offer any guidelines in the resolution of the current staffing crisis faced by South African children's homes. 3} To describe more closely the burnout syndrome. 4) To study possible etiological factors within a local context. Sixty three houseparents completed questionaires and three independent measures of burnout were obtained. The results were regarded as having failed to replicate those of the original study. The reason for this was found to be the low validity of the original instrument. The main conclusion drawn was that the line of research adopted in the original study can offer only very tentative guidelines towards the resolution of the staffing crisis faced until such time as valid and reliable instruments to measure burnout have been developed. Many of the suggested relationships between situational variables and ones of personal characteristics were confirmed for the local population of houseparents. , Thesis (MSocSci) -- Faculty of Humanities, Psychology, 1983
- Full Text:
- Date Issued: 1983
- Authors: Bath, Peter John
- Date: 1983
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/193118 , vital:45300
- Description: Aimed at replicating the results of an American study into "Burnout" in Group Home houseparents, this research had the following aims: 1) To ascertain the validity and reliability of the instrument used in the original study and presented as a "useful measure of burnout”. 2) To establish whether this line of research, within a highly problematic research field, can at present offer any guidelines in the resolution of the current staffing crisis faced by South African children's homes. 3} To describe more closely the burnout syndrome. 4) To study possible etiological factors within a local context. Sixty three houseparents completed questionaires and three independent measures of burnout were obtained. The results were regarded as having failed to replicate those of the original study. The reason for this was found to be the low validity of the original instrument. The main conclusion drawn was that the line of research adopted in the original study can offer only very tentative guidelines towards the resolution of the staffing crisis faced until such time as valid and reliable instruments to measure burnout have been developed. Many of the suggested relationships between situational variables and ones of personal characteristics were confirmed for the local population of houseparents. , Thesis (MSocSci) -- Faculty of Humanities, Psychology, 1983
- Full Text:
- Date Issued: 1983
A Feminist Analysis of Lyman Frank Baum’s The Wonderful Wizard of Oz, Lucy Maud Montgomery’s Anne of Green Gables and Frances Hodgson Burnett’s The Secret Garden
- Authors: Becker, Bonnie
- Date: 2013-01
- Subjects: Fiction , Children , Orphans
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/23214 , vital:55905
- Description: The primary aim of this project is to provide a close contextual and textual analysis of the selected children’s classics: The Wonderful Wizard of Oz, Anne of Green Gables and The Secret Garden using the feminist literary theory. From this perspective I have shown how the selected works of Lyman Frank Baum, Lucy Maud Montgomery and Frances Hodgson Burnett’s writing have contributed to women’s stereotypical roles within society and perpetuated their subjugated position. I have also conducted an examination of the extent to which the female protagonists attempt to emancipate themselves from gender oppression. A comparative study of the selected children’s texts has not yet been conducted and therefore this project serves as a significant contribution to this field of study. An exploration of the historical background of the authors and children’s literature is conducted to provide an overview into the inner workings of the writers’ lives and the historical significance of children’s literature as a genre. The theoretical framework of feminist literary theory is used in the analysis of the selected texts. The connection between feminist literary theory and children’s literature is highlighted and provides further understanding of the purpose of this study. The history of feminism as both a movement and a contemporary literary criticism is explored. Simone de Beauvoir’s The Second Sex is used when analysing the texts’ characters and how they are based on society’s stereotypical gender roles. Luce Irigaray’s Speculum of the Other Woman and This Sex Which is Not One is examined to aid in an exploration of psychological female oppression through feminine and masculine discourse evident in the creation of the novels’ female and male characters. Hélène Cixous’ “The Laugh of the Medusa” and The Newly Born Woman is interrogated according to the stereotypical ideology surrounding the terms masculinity and femininity and how these terms are interpreted in the selected works. Judith Butler’s Gender Trouble and Undoing Gender are additionally explored to assist in the understanding of the concept of gender performativity and through the lens of Butler’s interpolation of gender the move towards the emancipation of women is seen in the selected children’s texts. The close textual feminist analysis focuses on the female protagonists: Dorothy, Anne and Mary as well as the secondary female characters: the wicked witches, Aunt Em, the Queen of the Field-Mice, the princess made from china, Glinda’s female soldiers from The Wonderful Wizard of Oz; Marilla Cuthbert, Rachel Lynde and Diana Barry from Anne of Green Gables and Martha, Mrs Sowerby and Mrs Craven from The Secret Garden. The portrayal of the secondary male characters are additionally explored according to feminist literary theory: The Scarecrow, the Tin Woodman, the Lion and the wizard Oz from The Wonderful Wizard of Oz; Matthew Cuthbert and Gilbert Blythe from Anne of the Green Gables’ and Mr Craven, Colin Craven and Dickon Sowerby from The Secret Garden. The comparison of these children’s classics by Baum, Montgomery and Burnett provides insight into the selected works of all three writers, through the lens offered by feminist literary theory. Through the interrogation of these representative female protagonists found in early children’s literature, an understanding of not only the subordination of women, as evident in literature during this era, is illustrated but also the comprehension that women’s liberation was foreshadowed in these early children’s novels. , Thesis (MA) -- Faculty of Social Sciences and Humanities, 2013
- Full Text:
- Date Issued: 2013-01
- Authors: Becker, Bonnie
- Date: 2013-01
- Subjects: Fiction , Children , Orphans
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/23214 , vital:55905
- Description: The primary aim of this project is to provide a close contextual and textual analysis of the selected children’s classics: The Wonderful Wizard of Oz, Anne of Green Gables and The Secret Garden using the feminist literary theory. From this perspective I have shown how the selected works of Lyman Frank Baum, Lucy Maud Montgomery and Frances Hodgson Burnett’s writing have contributed to women’s stereotypical roles within society and perpetuated their subjugated position. I have also conducted an examination of the extent to which the female protagonists attempt to emancipate themselves from gender oppression. A comparative study of the selected children’s texts has not yet been conducted and therefore this project serves as a significant contribution to this field of study. An exploration of the historical background of the authors and children’s literature is conducted to provide an overview into the inner workings of the writers’ lives and the historical significance of children’s literature as a genre. The theoretical framework of feminist literary theory is used in the analysis of the selected texts. The connection between feminist literary theory and children’s literature is highlighted and provides further understanding of the purpose of this study. The history of feminism as both a movement and a contemporary literary criticism is explored. Simone de Beauvoir’s The Second Sex is used when analysing the texts’ characters and how they are based on society’s stereotypical gender roles. Luce Irigaray’s Speculum of the Other Woman and This Sex Which is Not One is examined to aid in an exploration of psychological female oppression through feminine and masculine discourse evident in the creation of the novels’ female and male characters. Hélène Cixous’ “The Laugh of the Medusa” and The Newly Born Woman is interrogated according to the stereotypical ideology surrounding the terms masculinity and femininity and how these terms are interpreted in the selected works. Judith Butler’s Gender Trouble and Undoing Gender are additionally explored to assist in the understanding of the concept of gender performativity and through the lens of Butler’s interpolation of gender the move towards the emancipation of women is seen in the selected children’s texts. The close textual feminist analysis focuses on the female protagonists: Dorothy, Anne and Mary as well as the secondary female characters: the wicked witches, Aunt Em, the Queen of the Field-Mice, the princess made from china, Glinda’s female soldiers from The Wonderful Wizard of Oz; Marilla Cuthbert, Rachel Lynde and Diana Barry from Anne of Green Gables and Martha, Mrs Sowerby and Mrs Craven from The Secret Garden. The portrayal of the secondary male characters are additionally explored according to feminist literary theory: The Scarecrow, the Tin Woodman, the Lion and the wizard Oz from The Wonderful Wizard of Oz; Matthew Cuthbert and Gilbert Blythe from Anne of the Green Gables’ and Mr Craven, Colin Craven and Dickon Sowerby from The Secret Garden. The comparison of these children’s classics by Baum, Montgomery and Burnett provides insight into the selected works of all three writers, through the lens offered by feminist literary theory. Through the interrogation of these representative female protagonists found in early children’s literature, an understanding of not only the subordination of women, as evident in literature during this era, is illustrated but also the comprehension that women’s liberation was foreshadowed in these early children’s novels. , Thesis (MA) -- Faculty of Social Sciences and Humanities, 2013
- Full Text:
- Date Issued: 2013-01
The role of Stress Inducible Protein 1 (STI1) in the regulation of actin dynamics
- Authors: Beckley, Samantha Joy
- Date: 2015
- Subjects: Heat shock proteins , Molecular chaperones , Actin , Microfilament proteins , Cell migration , Adenosine triphosphatase , Metastasis
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/193941 , vital:45409
- Description: Stress-inducible protein 1 (STI1) otherwise known as Hop (Hsp70/Hsp90 organising protein) is a highly conserved abundant co-chaperone of the Hsp70 and Hsp90 chaperones. STI1 acts as an adapter protein, where it regulates the transfer of protein substrates from Hsp70 to Hsp90 during the assembly of a number of chaperone-client protein complexes. The role of STI1 associating independently with non-chaperone proteins has become increasingly prominent. Recent data from colocalisation and co-sedimentation analyses in our laboratory suggested a direct interaction between STI1 and the cytoskeletal protein, actin. However, there was a lack of information on the motifs which mediated this interaction, as well as the exact role of STI1 in the regulation of cytoskeletal dynamics. Two putative actin binding motifs, DAYKKK (within the TPR2A domain) and a polyproline region (after the DP1 domain), were identified in mammalian STI1. Our data from in vitro interaction studies including surface plasmon resonance and high speed co-sedimentation assays suggested that both TPR1 and TPR2AB were required for the STI1-actin interaction, and peptides corresponding to either the DAYKKK or the polyproline motif, alone or in combination, could not block the STI1-actin interaction. Full length mSTI1 was shown to have ATPase activity and when combined with actin an increase in ATPase activity was seen. Ex vivo studies using STI1 knockdown shRNA HEK293T cells and non-targeting control shRNA HEK293T cells showed a change of F-actin morphology as well as reduction in levels of actin-binding proteins profilin, cofilin and tubulin in the STI1 knockdown cells. These data extend our understanding of the role of STI1 in regulating actin dynamics and may have implications for cell migration. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2015
- Full Text:
- Date Issued: 2015
- Authors: Beckley, Samantha Joy
- Date: 2015
- Subjects: Heat shock proteins , Molecular chaperones , Actin , Microfilament proteins , Cell migration , Adenosine triphosphatase , Metastasis
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/193941 , vital:45409
- Description: Stress-inducible protein 1 (STI1) otherwise known as Hop (Hsp70/Hsp90 organising protein) is a highly conserved abundant co-chaperone of the Hsp70 and Hsp90 chaperones. STI1 acts as an adapter protein, where it regulates the transfer of protein substrates from Hsp70 to Hsp90 during the assembly of a number of chaperone-client protein complexes. The role of STI1 associating independently with non-chaperone proteins has become increasingly prominent. Recent data from colocalisation and co-sedimentation analyses in our laboratory suggested a direct interaction between STI1 and the cytoskeletal protein, actin. However, there was a lack of information on the motifs which mediated this interaction, as well as the exact role of STI1 in the regulation of cytoskeletal dynamics. Two putative actin binding motifs, DAYKKK (within the TPR2A domain) and a polyproline region (after the DP1 domain), were identified in mammalian STI1. Our data from in vitro interaction studies including surface plasmon resonance and high speed co-sedimentation assays suggested that both TPR1 and TPR2AB were required for the STI1-actin interaction, and peptides corresponding to either the DAYKKK or the polyproline motif, alone or in combination, could not block the STI1-actin interaction. Full length mSTI1 was shown to have ATPase activity and when combined with actin an increase in ATPase activity was seen. Ex vivo studies using STI1 knockdown shRNA HEK293T cells and non-targeting control shRNA HEK293T cells showed a change of F-actin morphology as well as reduction in levels of actin-binding proteins profilin, cofilin and tubulin in the STI1 knockdown cells. These data extend our understanding of the role of STI1 in regulating actin dynamics and may have implications for cell migration. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2015
- Full Text:
- Date Issued: 2015
The technical efficiency of SACU Ports: a data envelopment analysis approach
- Authors: Bekebu, Siyanda
- Date: 2021-12
- Subjects: Free ports and zones -- Africa, Southern , Harbors -- Africa, Southern
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53813 , vital:45982
- Description: There ever growing international trade and increasing congestion of ports led to an increased focus attention on technical efficiency. Seaports are a central and necessary component in facilitating international trade. Yet, there is only limited comprehensive information available on the technical efficiency of African ports. The study investigated the technical efficiency of the SACU ports during the period 2014-2019 using DEA model. The DEA model is effective in resolving the measurement of port efficiency since the calculations are nonparametric and do not need definition or knowledge of a priori weights for the inputs or outputs, as is necessary for estimate of efficiency using production functions. To identify the roots of the technical inefficiency of the SACU ports, the study subdivided technical efficiency into pure technical and scale efficiency. The model used cargo handled, container throughput, ship calls as output variables. Whilst, quay cranes, number of tugboats, draft, quay length and number of quays were used as input variables. The study used the scores of DEA-BCC model as explanatory variables in Tobit model. The results showed that quay cranes and quay length are the cause of technical inefficiencies in the ports. , Thesis (MCom (Economics)) -- Faculty of Business and Economic Sciences, 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Bekebu, Siyanda
- Date: 2021-12
- Subjects: Free ports and zones -- Africa, Southern , Harbors -- Africa, Southern
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53813 , vital:45982
- Description: There ever growing international trade and increasing congestion of ports led to an increased focus attention on technical efficiency. Seaports are a central and necessary component in facilitating international trade. Yet, there is only limited comprehensive information available on the technical efficiency of African ports. The study investigated the technical efficiency of the SACU ports during the period 2014-2019 using DEA model. The DEA model is effective in resolving the measurement of port efficiency since the calculations are nonparametric and do not need definition or knowledge of a priori weights for the inputs or outputs, as is necessary for estimate of efficiency using production functions. To identify the roots of the technical inefficiency of the SACU ports, the study subdivided technical efficiency into pure technical and scale efficiency. The model used cargo handled, container throughput, ship calls as output variables. Whilst, quay cranes, number of tugboats, draft, quay length and number of quays were used as input variables. The study used the scores of DEA-BCC model as explanatory variables in Tobit model. The results showed that quay cranes and quay length are the cause of technical inefficiencies in the ports. , Thesis (MCom (Economics)) -- Faculty of Business and Economic Sciences, 2021
- Full Text:
- Date Issued: 2021-12
The effects of different shift patterns on nurses’ sleep-wake behaviours in selected, private healthcare facilities
- Authors: Bell, Emma Catherine
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424219 , vital:72134
- Description: Nurses are required to work shifts to provide 24-hour care, in which they complete physically and mentally demanding tasks. The length and type of shifts, particularly night shifts interfere with the natural sleep-wake behaviours, leading to extended wakefulness and overall reduced sleep, and increase the likelihood of sleepiness during subsequent shifts. This can in turn affected various cognitive processes such attention, vigilance and alertness, which are necessary during the care process. Sleepiness as a result of working shifts has also been associated with an increased risk accidents and error during the delivery of care. Given the unique demands and ways in which workplaces are structured, each context arranges its shifts in unique ways and thus, in order to determine how to manage the effects of shift work, it is important to understand how it affects self-reported fatigue and sleep, of, in this case, nurses. While there has been extensive research on this in the global north, to date, there has been limited research aimed at examining the effects of shift work on nurses’ sleep-wake behaviours and fatigue in the South African context. Therefore, the aim of this study is to characterise shift arrangements in selected private facilities and explore its effects on private healthcare nurses. This study adopted a cross-sectional, survey design using an amended version of Standard Shiftwork Index. The questionnaire included demographic and shift details and explored the impact of the shift systems on nurse sleep-wake behaviours and disturbances and fatigue and workload. It was distributed among shift working nurses registered with the South African Nursing Council across three selected, private, healthcare facilities in the Eastern Cape, over a two-month period. The responses were analysed with descriptive and inferential statistics, with open-ended questions analysed using a thematic analysis. A total of 51 nurses completed the survey. Nurses worked 12-hour shifts which included night shifts and day shifts with fixed start and end times. Over time was commonly reported and generally, nurses reported having very little control over their shift arrangements. Overall, nurses slept less than what they reported they needed on duty days, with nurses working both day and night shifts reporting to sleep less than the globally recommended required sleep. This was compensated for by longer sleep durations during days off. The data collection revealed that three different shift arrangements were in use, including permanent day shifts, permanent night shifts and rotating shift work including nights, with permanent night nurses working significantly more consecutive shifts (seven) than the other two shift types and having significantly more days off (seven) as well. While there were no significant differences in self-reported sleep across the three shift types, permanent night nurses were found to have the shortest sleep. During days off, rotating nurse reported significantly longer sleep times compared to day shift workers which may point to the need to catch up from sleep debt. Rotating nurses experienced the greater total disturbances to their sleep than permanent day and permanent night shift nurses. While not statistically significant, it may point to the fact that rotating shift workers could not obtain regularly timed sleep (due to having to change their schedules) compared to permanent day and night nurses. Workload (physical, emotional, mental and time pressure) did not differ between the shifts (day or night) or the shift types, but did reflect a heavier workload, possibly due to the data collection occurring during the 5th wave of the COVID 19 pandemic. This study highlights that nurses in private healthcare facilities are working extended hours which were associated with reduced total sleep, irrespective of the nature of the shift, with rotating shift nurses experiencing some degree of greater disturbances to their sleep. The number, duration speed and direction of the shifts of rotating nurses needs to be explored further, whilst also exploring the influence of individual factors on sleep-wake behaviours of nurses. It may be beneficial for the healthcare facilities to implement fatigue management strategies to mitigate the negative impacts of shift work, given the impact that this may impact the delivery of care. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Bell, Emma Catherine
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424219 , vital:72134
- Description: Nurses are required to work shifts to provide 24-hour care, in which they complete physically and mentally demanding tasks. The length and type of shifts, particularly night shifts interfere with the natural sleep-wake behaviours, leading to extended wakefulness and overall reduced sleep, and increase the likelihood of sleepiness during subsequent shifts. This can in turn affected various cognitive processes such attention, vigilance and alertness, which are necessary during the care process. Sleepiness as a result of working shifts has also been associated with an increased risk accidents and error during the delivery of care. Given the unique demands and ways in which workplaces are structured, each context arranges its shifts in unique ways and thus, in order to determine how to manage the effects of shift work, it is important to understand how it affects self-reported fatigue and sleep, of, in this case, nurses. While there has been extensive research on this in the global north, to date, there has been limited research aimed at examining the effects of shift work on nurses’ sleep-wake behaviours and fatigue in the South African context. Therefore, the aim of this study is to characterise shift arrangements in selected private facilities and explore its effects on private healthcare nurses. This study adopted a cross-sectional, survey design using an amended version of Standard Shiftwork Index. The questionnaire included demographic and shift details and explored the impact of the shift systems on nurse sleep-wake behaviours and disturbances and fatigue and workload. It was distributed among shift working nurses registered with the South African Nursing Council across three selected, private, healthcare facilities in the Eastern Cape, over a two-month period. The responses were analysed with descriptive and inferential statistics, with open-ended questions analysed using a thematic analysis. A total of 51 nurses completed the survey. Nurses worked 12-hour shifts which included night shifts and day shifts with fixed start and end times. Over time was commonly reported and generally, nurses reported having very little control over their shift arrangements. Overall, nurses slept less than what they reported they needed on duty days, with nurses working both day and night shifts reporting to sleep less than the globally recommended required sleep. This was compensated for by longer sleep durations during days off. The data collection revealed that three different shift arrangements were in use, including permanent day shifts, permanent night shifts and rotating shift work including nights, with permanent night nurses working significantly more consecutive shifts (seven) than the other two shift types and having significantly more days off (seven) as well. While there were no significant differences in self-reported sleep across the three shift types, permanent night nurses were found to have the shortest sleep. During days off, rotating nurse reported significantly longer sleep times compared to day shift workers which may point to the need to catch up from sleep debt. Rotating nurses experienced the greater total disturbances to their sleep than permanent day and permanent night shift nurses. While not statistically significant, it may point to the fact that rotating shift workers could not obtain regularly timed sleep (due to having to change their schedules) compared to permanent day and night nurses. Workload (physical, emotional, mental and time pressure) did not differ between the shifts (day or night) or the shift types, but did reflect a heavier workload, possibly due to the data collection occurring during the 5th wave of the COVID 19 pandemic. This study highlights that nurses in private healthcare facilities are working extended hours which were associated with reduced total sleep, irrespective of the nature of the shift, with rotating shift nurses experiencing some degree of greater disturbances to their sleep. The number, duration speed and direction of the shifts of rotating nurses needs to be explored further, whilst also exploring the influence of individual factors on sleep-wake behaviours of nurses. It may be beneficial for the healthcare facilities to implement fatigue management strategies to mitigate the negative impacts of shift work, given the impact that this may impact the delivery of care. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2023
- Full Text:
- Date Issued: 2023-10-13
Using narratives to understand consumer behaviour, nutrition knowledge perceptions and experiences amongst women at Thembeni Location
- Ben, Sive https://orcid.org/0000-0003-4186-924X
- Authors: Ben, Sive https://orcid.org/0000-0003-4186-924X
- Date: 2021-04
- Subjects: Women -- Nutrition
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20164 , vital:45381
- Description: Orientation: Nutrition knowledge is an important aspect which shapes the lived experiences of women when they are making a purchase. South Africa, being a developing country, is faced with many challenges that have in turn subjected rural women to various challenges in approaching nutrition. These challenges include but are not limited to low economic status, low levels of education, and lack of developmental programmes that are structured to cater for rural women. Purpose: The purpose of this study was to understand the experiences and the perceptions of rural women concerning nutrition knowledge. Motivation for the study: This study was conducted with a motivation to understand how a sample of women in a rural area approach issues of nutrition. In understanding this, women can be empowered in asserting the approach to consumer behaviour. Research design: A phenomenological philosophy was adopted using a qualitative tradition in pursuit of the research objective. A judgemental sampling technique was utilised to sample 20 women and semi-structured interviews were undertaken and the gathered data on the experiences and perceptions of women was analysed by way of narrative analysis. , Thesis (MCom) -- Faculty of Management and Commerce, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Ben, Sive https://orcid.org/0000-0003-4186-924X
- Date: 2021-04
- Subjects: Women -- Nutrition
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20164 , vital:45381
- Description: Orientation: Nutrition knowledge is an important aspect which shapes the lived experiences of women when they are making a purchase. South Africa, being a developing country, is faced with many challenges that have in turn subjected rural women to various challenges in approaching nutrition. These challenges include but are not limited to low economic status, low levels of education, and lack of developmental programmes that are structured to cater for rural women. Purpose: The purpose of this study was to understand the experiences and the perceptions of rural women concerning nutrition knowledge. Motivation for the study: This study was conducted with a motivation to understand how a sample of women in a rural area approach issues of nutrition. In understanding this, women can be empowered in asserting the approach to consumer behaviour. Research design: A phenomenological philosophy was adopted using a qualitative tradition in pursuit of the research objective. A judgemental sampling technique was utilised to sample 20 women and semi-structured interviews were undertaken and the gathered data on the experiences and perceptions of women was analysed by way of narrative analysis. , Thesis (MCom) -- Faculty of Management and Commerce, 2021
- Full Text:
- Date Issued: 2021-04
Investigating talent management strategies influencing the retention of employees with technical expertise at Aspen Pharmacare
- Ben-Mazwi Matolengwe, Yonela
- Authors: Ben-Mazwi Matolengwe, Yonela
- Date: 2021-04
- Subjects: Employee retention -- South Africa , Talent management -- South Africa , Human capital
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/50944 , vital:43174
- Description: This study examines the influence of talent management strategies on employee retention with employee engagement as a mediating variable. This study was conducted at Aspen Pharmacare Port Elizabeth site, South Africa. The population in this study is approximately 1500 employees from Aspen Pharmacare Port Elizabeth. The sampling method uses census techniques so that the number of samples used is 49 employees. The research data was collected using an online questionnaire which is then analysed using a path analysis technique using SPSS software to examine the relationships among the variables, which are: employee value proposition, work motivation and employee performance. The results show that there is a positive relationship between all talent management strategies and retention. Leadership has a largely significant correlation with retention, however, it is indicated that engagement is a mediating variable. Employees with technical expertise value the impact that leadership has in their roles at the organisation. , Thesis (MBA) -- Faculty of Business and Economic Sciences, Business Administration, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Ben-Mazwi Matolengwe, Yonela
- Date: 2021-04
- Subjects: Employee retention -- South Africa , Talent management -- South Africa , Human capital
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/50944 , vital:43174
- Description: This study examines the influence of talent management strategies on employee retention with employee engagement as a mediating variable. This study was conducted at Aspen Pharmacare Port Elizabeth site, South Africa. The population in this study is approximately 1500 employees from Aspen Pharmacare Port Elizabeth. The sampling method uses census techniques so that the number of samples used is 49 employees. The research data was collected using an online questionnaire which is then analysed using a path analysis technique using SPSS software to examine the relationships among the variables, which are: employee value proposition, work motivation and employee performance. The results show that there is a positive relationship between all talent management strategies and retention. Leadership has a largely significant correlation with retention, however, it is indicated that engagement is a mediating variable. Employees with technical expertise value the impact that leadership has in their roles at the organisation. , Thesis (MBA) -- Faculty of Business and Economic Sciences, Business Administration, 2021
- Full Text:
- Date Issued: 2021-04
Genetic analysis and field application of a UV-tolerant strain of CrleGV for improved control of Thaumatotibia leucotreta
- Authors: Bennett, Tahnee Tashia
- Date: 2022-10-14
- Subjects: Cryptophlebia leucotreta Biological control , Pests Integrated control , Biological pest control agents , Ultraviolet radiation , Oligonucleotides
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/362741 , vital:65358
- Description: Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), also known as false codling moth (FCM), is indigenous to sub-Saharan Africa. Thaumatotibia leucotreta has been controlled through an integrated pest management (IPM) programme, which includes chemical control, sterile insect technique (SIT), cultural and biological control. As part of the biological control, a key component is the use of Cryptophlebia leucotreta granulovirus (CrleGV-SA). Currently, CryptogranTM, a commercial formulation of CrleGV, is the preferred product to use in South Africa for the control of T. leucotreta. The registration of the biopesticide Cryptogran (River bioscience, South Africa) was established after conducting extensive field trials with CrleGV-SA. One of the major factors affecting the baculovirus efficacy in the field is UV irradiation. A UV-tolerant Cryptophlebia leucotreta granulovirus (CrleGV-SA-C5) isolate was isolated after consecutive cycles of UV exposure. This UV-tolerant isolate is genetically distinct from the CrleGV-SA isolate. The CrleGV-SA-C5 isolate has the potential as a biological control agent. The control of T. leucotreta in South Africa could be improved by the development of novel isolates into new biopesticide formulations. To date, there has not been any field trials conducted on the CrleGV-SA-C5 isolate. Therefore, it is important to determine the biological and genetic stability of this isolate and to conduct field trials with CrleGV-SA- C5 to test the efficacy of the isolate before possible production into a biopesticide. A de novo assembly was conducted to reassemble the genome of CrleGV-SA-C5 which was followed by a sequence comparison with the CrleGV-SA genome. The identification of SNPs, led to the design of oligonucleotides flanking the regions where the SNPs were detected. Polymerase chain reaction amplification of the target regions was conducted using the oligonucleotides. After sequence comparison, seven SNPs were detected and PCR amplification was successful using the three oligonucleotides, Pif-2, HypoP and Lef-8/HP. To differentiate between CrleGV-SA-C5 and CrleGV-SA genomes and confirm the presence of the SNPs, two methods of screening were conducted. The first was the construction of six plasmids, the plasmids contained the targeted pif-2, HypoP, and the Lef-8/HP insert regions from both the CrleGV-SA-C5 and CrleGV-SA genome region where the SNPs were identified, followed by sequencing. The Five recombinant plasmids, pC5_Pif-2, pSA_Pif-2, pC5_HypoP, pSA_HypoP, and pC5_Lef-8/HP were successfully sequenced. No amplicon was obtained for one of the plasmids used as template (pSA_Lef-8/HP) and therefore the PCR product used for cloning was sequenced instead. Sequence alignment confirmed the presence of four of the five targeted SNPs in the genome of the CrleGV-SA-C5 isolate. However, of these only one SNP (UV_7) rendered a suitable marker for the differentiation between the CrleGV-SA-C5 and CrleGV-SA isolates as the SNPs, UV_2, UV_3 and UV_5, were also present in the CrleGV- SA sequences. The second screening method was a quantitative polymerase chain reaction (qPCR) melt curve analysis to differentiate between the CrleGV-SA-C5 and CrleGV-SA isolates. qPCR melt curve analysis was done using the CrleGV-SA-C5 and CrleGV-SA HypoP PCR products. This technique was unable to differentiate between the CrleGV-SA-C5 and CrleGV-SA isolates. However, this may be as a result of sequence data confirming that SNP UV_5 originally identified in the CrleGV-SA-C5 HypoP region was identical to the SNP at the same position in the CrleGV-SA HypoP region. Following the differentiation of the CrleGV-SA-C5 and CrleGV-SA isolates through two screening methods, the genetic integrity of the CrleGV-SA-C5 isolate after two virus bulk-ups was determined by PCR amplification of the target regions in the bulk-up virus followed by sequencing. Prior to virus bulk-up, surface dose bioassays were conducted on 4th instar larvae and LC50 and LC90 values of 4.01 x 106 OBs/ml and 8.75 x 109 OBs/ml respectively were obtained. The CrleGV-SA-C5 isolate was then bulked up in fourth instar T. leucotreta larvae using the LC90 value that was determined. Sequencing of the target regions from the CrleGV- SA-C5_BU2 (bulk-up 2) was conducted. Sequencing results confirmed the presence of the target SNPs in the CrleGV-SA-C5_BU2 genome. The UV-tolerance of the CrleGV-SA-C5 isolate in comparison to the CrleGV-SA isolate was evaluated by detached fruit bioassays under natural UV irradiation. Two detached fruit bioassays were set-up, a UV exposure and a non-UV exposure bioassay set-up. Three treatments were used for each bioassay set-up which were the viruses CrleGV-SA-C5 and CrleGV-SA and a ddH2O control. Statistical analysis indicated that there was no significant difference between the virus treatments in both the UV exposed detached fruit bioassay and the non-UV exposed detached fruit bioassay. This study is the second study to report on the de novo assembly of the CrleGV-SA-C5 and sequence comparison with the CrleGV-SA genome, and the first to report on the UV-tolerance of the CrleGV-SA-C5 isolate by detached fruit bioassays. Future work could involve further evaluation of intraspecific genetic variability in the CrleGV-SA-C5 isolate and to identify any additional SNPs present within the genome that can be used as suitable markers for differentiation between the CrleGV-SA-C5 and CrleGV-SA isolates. It was recognised that it is required to conduct further detached fruit bioassays and field trials, but with improved protocols, for the efficacy and UV-tolerance of the CrleGV-SA-C5 isolate to be conclusively determined. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Bennett, Tahnee Tashia
- Date: 2022-10-14
- Subjects: Cryptophlebia leucotreta Biological control , Pests Integrated control , Biological pest control agents , Ultraviolet radiation , Oligonucleotides
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/362741 , vital:65358
- Description: Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), also known as false codling moth (FCM), is indigenous to sub-Saharan Africa. Thaumatotibia leucotreta has been controlled through an integrated pest management (IPM) programme, which includes chemical control, sterile insect technique (SIT), cultural and biological control. As part of the biological control, a key component is the use of Cryptophlebia leucotreta granulovirus (CrleGV-SA). Currently, CryptogranTM, a commercial formulation of CrleGV, is the preferred product to use in South Africa for the control of T. leucotreta. The registration of the biopesticide Cryptogran (River bioscience, South Africa) was established after conducting extensive field trials with CrleGV-SA. One of the major factors affecting the baculovirus efficacy in the field is UV irradiation. A UV-tolerant Cryptophlebia leucotreta granulovirus (CrleGV-SA-C5) isolate was isolated after consecutive cycles of UV exposure. This UV-tolerant isolate is genetically distinct from the CrleGV-SA isolate. The CrleGV-SA-C5 isolate has the potential as a biological control agent. The control of T. leucotreta in South Africa could be improved by the development of novel isolates into new biopesticide formulations. To date, there has not been any field trials conducted on the CrleGV-SA-C5 isolate. Therefore, it is important to determine the biological and genetic stability of this isolate and to conduct field trials with CrleGV-SA- C5 to test the efficacy of the isolate before possible production into a biopesticide. A de novo assembly was conducted to reassemble the genome of CrleGV-SA-C5 which was followed by a sequence comparison with the CrleGV-SA genome. The identification of SNPs, led to the design of oligonucleotides flanking the regions where the SNPs were detected. Polymerase chain reaction amplification of the target regions was conducted using the oligonucleotides. After sequence comparison, seven SNPs were detected and PCR amplification was successful using the three oligonucleotides, Pif-2, HypoP and Lef-8/HP. To differentiate between CrleGV-SA-C5 and CrleGV-SA genomes and confirm the presence of the SNPs, two methods of screening were conducted. The first was the construction of six plasmids, the plasmids contained the targeted pif-2, HypoP, and the Lef-8/HP insert regions from both the CrleGV-SA-C5 and CrleGV-SA genome region where the SNPs were identified, followed by sequencing. The Five recombinant plasmids, pC5_Pif-2, pSA_Pif-2, pC5_HypoP, pSA_HypoP, and pC5_Lef-8/HP were successfully sequenced. No amplicon was obtained for one of the plasmids used as template (pSA_Lef-8/HP) and therefore the PCR product used for cloning was sequenced instead. Sequence alignment confirmed the presence of four of the five targeted SNPs in the genome of the CrleGV-SA-C5 isolate. However, of these only one SNP (UV_7) rendered a suitable marker for the differentiation between the CrleGV-SA-C5 and CrleGV-SA isolates as the SNPs, UV_2, UV_3 and UV_5, were also present in the CrleGV- SA sequences. The second screening method was a quantitative polymerase chain reaction (qPCR) melt curve analysis to differentiate between the CrleGV-SA-C5 and CrleGV-SA isolates. qPCR melt curve analysis was done using the CrleGV-SA-C5 and CrleGV-SA HypoP PCR products. This technique was unable to differentiate between the CrleGV-SA-C5 and CrleGV-SA isolates. However, this may be as a result of sequence data confirming that SNP UV_5 originally identified in the CrleGV-SA-C5 HypoP region was identical to the SNP at the same position in the CrleGV-SA HypoP region. Following the differentiation of the CrleGV-SA-C5 and CrleGV-SA isolates through two screening methods, the genetic integrity of the CrleGV-SA-C5 isolate after two virus bulk-ups was determined by PCR amplification of the target regions in the bulk-up virus followed by sequencing. Prior to virus bulk-up, surface dose bioassays were conducted on 4th instar larvae and LC50 and LC90 values of 4.01 x 106 OBs/ml and 8.75 x 109 OBs/ml respectively were obtained. The CrleGV-SA-C5 isolate was then bulked up in fourth instar T. leucotreta larvae using the LC90 value that was determined. Sequencing of the target regions from the CrleGV- SA-C5_BU2 (bulk-up 2) was conducted. Sequencing results confirmed the presence of the target SNPs in the CrleGV-SA-C5_BU2 genome. The UV-tolerance of the CrleGV-SA-C5 isolate in comparison to the CrleGV-SA isolate was evaluated by detached fruit bioassays under natural UV irradiation. Two detached fruit bioassays were set-up, a UV exposure and a non-UV exposure bioassay set-up. Three treatments were used for each bioassay set-up which were the viruses CrleGV-SA-C5 and CrleGV-SA and a ddH2O control. Statistical analysis indicated that there was no significant difference between the virus treatments in both the UV exposed detached fruit bioassay and the non-UV exposed detached fruit bioassay. This study is the second study to report on the de novo assembly of the CrleGV-SA-C5 and sequence comparison with the CrleGV-SA genome, and the first to report on the UV-tolerance of the CrleGV-SA-C5 isolate by detached fruit bioassays. Future work could involve further evaluation of intraspecific genetic variability in the CrleGV-SA-C5 isolate and to identify any additional SNPs present within the genome that can be used as suitable markers for differentiation between the CrleGV-SA-C5 and CrleGV-SA isolates. It was recognised that it is required to conduct further detached fruit bioassays and field trials, but with improved protocols, for the efficacy and UV-tolerance of the CrleGV-SA-C5 isolate to be conclusively determined. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2022
- Full Text:
- Date Issued: 2022-10-14