Customer relationship management in small to medium tourism enterprises (SMTEs) in the Eastern Cape Province
- Authors: Vallabh, Dinesh
- Date: 2014
- Subjects: Customer relations -- Management , Small business -- South Africa -- Eastern Cape , Tourism -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9322 , http://hdl.handle.net/10948/d1020797
- Description: The role of entrepreneurship in small to medium tourism enterprises is well recognised and acknowledged as a significant contributor to economic development and employment opportunities. Worldwide, small to medium tourism enterprises play a dominant role in the tourism industry. These businesses are often vulnerable to external economic forces and find it increasingly difficult to transform their strategic and operational management to face the challenges placed upon them. This study focuses on small to medium tourism enterprises in the Eastern Cape Province, which is economically the poorest province of South Africa. To ensure the growth and sustainability of small to medium tourism enterprises, owners need to make efficient and effective business decisions regarding the challenges their businesses face. The study examines the factors impacting customer relationship management in the context of small to medium tourism enterprises in the Eastern Cape. Customer relationship management, that is, building relationships with customers, has become of pivotal importance to many organisations as businesses strive to be competitive and profitable. While large organisations practice customer relationship management to enable them to better target profitable customers, improve customer services, enhance customer retention and ultimately improve business performance, small businesses often need assistance in understanding and effecting this complex relationship. The factors that could impact customer relationship management in the organisations are the focus of this study. Three major factors were identified, namely, strategic, operational, and organisational factors. The study furthermore examined the extent to which these factors are present in the tourism and hospitality sector of the Eastern Cape and investigated the relationships between these factors. Quantitative research was deemed appropriate for this study. Systematic random sampling was employed to select a sample of 332 respondent organisations from the 2012 database of the Eastern Cape Parks and Tourism Agency consisting of formally registered small to medium tourism enterprises. A total of 310 usable questionnaires were finally obtained. Both descriptive and inferential statistics were used in the study. Descriptive statistics were computed to reflect the organisations‟ and respondent managers‟ general characteristics and to summarise their measurement scores. Using inferential statistics, the study further investigated relationships between customer relationship management factors, as well as demographic factors. Data were subjected to exploratory factor analysis and both the validity (refer to section 2.10.1) and reliability (refer to section 2.10.2) of the research instrument was assessed. The relationships between customer relationship management variables were also investigated (refer to section 2.11.4). The research results support an overall significant association between customer relationship management readiness and business strategy, customer strategy, touch points and competencies, skills and technology. Relationships were also explored among customer relationship management factors and demographic characteristics. Significant results were found between perceived business performance and the gender of managers, family businesses and gross annual turnover. The most salient contributions of this research can be summarised as follows. The overview of the importance of tourism and the role of small to medium enterprises in the tourism and hospitality industry of the Eastern Cape will benefit researchers and potential owners who have an interest in this sector. The study contributes to an improved understanding of the factors that should precede customer relationship management. The study established a profile of the small to medium tourism enterprises in the Eastern Cape which can serve as a basis for future research. A measuring instrument for assessing respondents‟ views on the existence of the strategic, operational and organisational factors in their organisations was developed. This instrument showed good internal validity and reliability and can serve as a basis for the same purpose in contexts other than the tourism and hospitality sector. This research has made a contribution toward a largely under-researched area concerning customer relationship management in small to medium enterprises. Recommendations for managers and consideration of future research included the following. Managers need to have a strategic vision and a strong customer-centric focus. Through understanding customers and their needs, offerings can be tailored to maximize the overall value of customers, thereby, improving business performance. Through efficient operational processes in place, enhanced customer service levels can be attained in the organisations. Managers need to effectively manage customer information through data warehousing and technology. Top management commitment is a crucial element for ensuring improved customer services. Managers need to train staff with respect to customer services, thus enhancing CRM. Future researchers can conduct a longitudinal study and investigate the same factors which could impact customer relationship management. A verification of the usefulness of the measuring instrument in examining the determinants of customer relationship management and the level of development regarding other small businesses is suggested. It is recommended that this study be replicated abroad in an effort to verify to what extent the determinants of customer relationship management are evident in small businesses of other countries.
- Full Text:
- Date Issued: 2014
- Authors: Vallabh, Dinesh
- Date: 2014
- Subjects: Customer relations -- Management , Small business -- South Africa -- Eastern Cape , Tourism -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9322 , http://hdl.handle.net/10948/d1020797
- Description: The role of entrepreneurship in small to medium tourism enterprises is well recognised and acknowledged as a significant contributor to economic development and employment opportunities. Worldwide, small to medium tourism enterprises play a dominant role in the tourism industry. These businesses are often vulnerable to external economic forces and find it increasingly difficult to transform their strategic and operational management to face the challenges placed upon them. This study focuses on small to medium tourism enterprises in the Eastern Cape Province, which is economically the poorest province of South Africa. To ensure the growth and sustainability of small to medium tourism enterprises, owners need to make efficient and effective business decisions regarding the challenges their businesses face. The study examines the factors impacting customer relationship management in the context of small to medium tourism enterprises in the Eastern Cape. Customer relationship management, that is, building relationships with customers, has become of pivotal importance to many organisations as businesses strive to be competitive and profitable. While large organisations practice customer relationship management to enable them to better target profitable customers, improve customer services, enhance customer retention and ultimately improve business performance, small businesses often need assistance in understanding and effecting this complex relationship. The factors that could impact customer relationship management in the organisations are the focus of this study. Three major factors were identified, namely, strategic, operational, and organisational factors. The study furthermore examined the extent to which these factors are present in the tourism and hospitality sector of the Eastern Cape and investigated the relationships between these factors. Quantitative research was deemed appropriate for this study. Systematic random sampling was employed to select a sample of 332 respondent organisations from the 2012 database of the Eastern Cape Parks and Tourism Agency consisting of formally registered small to medium tourism enterprises. A total of 310 usable questionnaires were finally obtained. Both descriptive and inferential statistics were used in the study. Descriptive statistics were computed to reflect the organisations‟ and respondent managers‟ general characteristics and to summarise their measurement scores. Using inferential statistics, the study further investigated relationships between customer relationship management factors, as well as demographic factors. Data were subjected to exploratory factor analysis and both the validity (refer to section 2.10.1) and reliability (refer to section 2.10.2) of the research instrument was assessed. The relationships between customer relationship management variables were also investigated (refer to section 2.11.4). The research results support an overall significant association between customer relationship management readiness and business strategy, customer strategy, touch points and competencies, skills and technology. Relationships were also explored among customer relationship management factors and demographic characteristics. Significant results were found between perceived business performance and the gender of managers, family businesses and gross annual turnover. The most salient contributions of this research can be summarised as follows. The overview of the importance of tourism and the role of small to medium enterprises in the tourism and hospitality industry of the Eastern Cape will benefit researchers and potential owners who have an interest in this sector. The study contributes to an improved understanding of the factors that should precede customer relationship management. The study established a profile of the small to medium tourism enterprises in the Eastern Cape which can serve as a basis for future research. A measuring instrument for assessing respondents‟ views on the existence of the strategic, operational and organisational factors in their organisations was developed. This instrument showed good internal validity and reliability and can serve as a basis for the same purpose in contexts other than the tourism and hospitality sector. This research has made a contribution toward a largely under-researched area concerning customer relationship management in small to medium enterprises. Recommendations for managers and consideration of future research included the following. Managers need to have a strategic vision and a strong customer-centric focus. Through understanding customers and their needs, offerings can be tailored to maximize the overall value of customers, thereby, improving business performance. Through efficient operational processes in place, enhanced customer service levels can be attained in the organisations. Managers need to effectively manage customer information through data warehousing and technology. Top management commitment is a crucial element for ensuring improved customer services. Managers need to train staff with respect to customer services, thus enhancing CRM. Future researchers can conduct a longitudinal study and investigate the same factors which could impact customer relationship management. A verification of the usefulness of the measuring instrument in examining the determinants of customer relationship management and the level of development regarding other small businesses is suggested. It is recommended that this study be replicated abroad in an effort to verify to what extent the determinants of customer relationship management are evident in small businesses of other countries.
- Full Text:
- Date Issued: 2014
Determinants of cloud computing: adoption and application by high school learners
- Authors: Nyembezi, Nceba
- Date: 2014
- Subjects: Cloud computing -- Study and teaching -- South Africa -- Eastern Cape , High schools -- Computer networks -- South Africa -- Eastern Cape , High school students -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD (Education)
- Identifier: http://hdl.handle.net/10353/1339 , vital:26547 , Cloud computing -- Study and teaching -- South Africa -- Eastern Cape , High schools -- Computer networks -- South Africa -- Eastern Cape , High school students -- South Africa -- Eastern Cape
- Description: The current study investigated the determinants of Internet services’ adoption and use among high school learners in the East London Education District, in the Eastern Cape. Underpinned by the Unified Theory of Acceptance and Use of Technology, the research questions included: (1) What is the effect of performance expectancy on the learner’s intention to adopt and use Internet services? (2) What degree of variation exists for effort expectancy on the learner’s intention to adopt and use Internet services? (3) How much of the determinants explain the usage of Internet services? (4) Which is (are) the best predictor(s) of Internet service usage given a set of determinants? (5) What is the effect of confounding variables (if any) on Internet services’ adoption and usage? (6) Which model can be designed based on the best predictor(s) of Internet services’ adoption and usage for secondary school learners? A quantitative approach based on the positivist paradigm was used to quantify the relationships among various factors that contribute to Internet services’ adoption and use. The research design used was a survey. Data were collected through structured questionnaires. Out of 286 questionnaires issued, the response rate was 40.6%. The study sample size was 116 high school learners using simple random sampling. The data was analysed using the multiple regression analysis technique, and Pearson correlations. Out of the four determinants from the UTAUT, performance expectancy was the strongest predictor of intention to adopt Internet services. Large positive correlations ranging from r = 0.638 up to r = 0.989 were found among performance expectancy and effort expectancy variables towards the intention to use Internet services, significant at p < 0.05. To enhance the efficiency of the UTAUT model, this study has designed the Adoption and Application of Technology for Learning (AATL) model, which added the price of Internet, persistent use of Internet, and perceptions about Internet use.
- Full Text:
- Date Issued: 2014
- Authors: Nyembezi, Nceba
- Date: 2014
- Subjects: Cloud computing -- Study and teaching -- South Africa -- Eastern Cape , High schools -- Computer networks -- South Africa -- Eastern Cape , High school students -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD (Education)
- Identifier: http://hdl.handle.net/10353/1339 , vital:26547 , Cloud computing -- Study and teaching -- South Africa -- Eastern Cape , High schools -- Computer networks -- South Africa -- Eastern Cape , High school students -- South Africa -- Eastern Cape
- Description: The current study investigated the determinants of Internet services’ adoption and use among high school learners in the East London Education District, in the Eastern Cape. Underpinned by the Unified Theory of Acceptance and Use of Technology, the research questions included: (1) What is the effect of performance expectancy on the learner’s intention to adopt and use Internet services? (2) What degree of variation exists for effort expectancy on the learner’s intention to adopt and use Internet services? (3) How much of the determinants explain the usage of Internet services? (4) Which is (are) the best predictor(s) of Internet service usage given a set of determinants? (5) What is the effect of confounding variables (if any) on Internet services’ adoption and usage? (6) Which model can be designed based on the best predictor(s) of Internet services’ adoption and usage for secondary school learners? A quantitative approach based on the positivist paradigm was used to quantify the relationships among various factors that contribute to Internet services’ adoption and use. The research design used was a survey. Data were collected through structured questionnaires. Out of 286 questionnaires issued, the response rate was 40.6%. The study sample size was 116 high school learners using simple random sampling. The data was analysed using the multiple regression analysis technique, and Pearson correlations. Out of the four determinants from the UTAUT, performance expectancy was the strongest predictor of intention to adopt Internet services. Large positive correlations ranging from r = 0.638 up to r = 0.989 were found among performance expectancy and effort expectancy variables towards the intention to use Internet services, significant at p < 0.05. To enhance the efficiency of the UTAUT model, this study has designed the Adoption and Application of Technology for Learning (AATL) model, which added the price of Internet, persistent use of Internet, and perceptions about Internet use.
- Full Text:
- Date Issued: 2014
Determinants of psycho-social well-being of informal caregivers of physically challenged children in South-Western Nigeria
- Authors: Oyeleke, Isaac Ajiboye
- Date: 2014
- Language: English
- Type: Thesis , Doctoral , PhD (Social Work)
- Identifier: vital:11767 , http://hdl.handle.net/10353/d1015356
- Description: Informal caregiving denotes care that is provided by a family member or friend rather than by a professional who is reimbursed for services. Assuming a caregiving role can be stressful and burdensome. The effects of caregiving on the caregiver's health are moderated by individual differences in resources and vulnerabilities, such as socioeconomic status, prior health status, and level of social support. This work describes the determinant of psycho-social well-being of informal caregivers of physically challenged children in southwest of Nigeria. This study is guided theoretically by Ryff”s psychosocial well-being theory, The study adopted expo facto research design. Multistage samplings involving the use of random and purposive techniques were used to select 812 respondents who are informal caregivers. Social support questionnaire, Social support satisfaction level, Ryff’s psychological well-being scale were used. Findings indicated that social support predicted psycho-social well-being of informal caregivers of physically challenged children. Social support and satisfaction level combine together have impact on psycho-social well-being of informal caregivers of physically challenged children. More also, socio-economic factors such as occupation, educational level and income also predict psycho-social well-being of informal caregivers. Finally, marital status and gender also contribute to well-being of caregivers. It was therefore, recommended that social inclusion should be pursued with de-institutionalization of children with disability. Parents of children with disability should be encouraged to form support group and as well as encouraging fathers of children with disability to take an active part in ensuring their children with disability well-being. More also, there is need to empower informal caregivers through training and education. More importantly governments at the three levels ( Federal, State and local) should assist caregivers at ensuring their own and that of their children with disability well-being through improvement on various existing social welfare services in the country.
- Full Text:
- Date Issued: 2014
- Authors: Oyeleke, Isaac Ajiboye
- Date: 2014
- Language: English
- Type: Thesis , Doctoral , PhD (Social Work)
- Identifier: vital:11767 , http://hdl.handle.net/10353/d1015356
- Description: Informal caregiving denotes care that is provided by a family member or friend rather than by a professional who is reimbursed for services. Assuming a caregiving role can be stressful and burdensome. The effects of caregiving on the caregiver's health are moderated by individual differences in resources and vulnerabilities, such as socioeconomic status, prior health status, and level of social support. This work describes the determinant of psycho-social well-being of informal caregivers of physically challenged children in southwest of Nigeria. This study is guided theoretically by Ryff”s psychosocial well-being theory, The study adopted expo facto research design. Multistage samplings involving the use of random and purposive techniques were used to select 812 respondents who are informal caregivers. Social support questionnaire, Social support satisfaction level, Ryff’s psychological well-being scale were used. Findings indicated that social support predicted psycho-social well-being of informal caregivers of physically challenged children. Social support and satisfaction level combine together have impact on psycho-social well-being of informal caregivers of physically challenged children. More also, socio-economic factors such as occupation, educational level and income also predict psycho-social well-being of informal caregivers. Finally, marital status and gender also contribute to well-being of caregivers. It was therefore, recommended that social inclusion should be pursued with de-institutionalization of children with disability. Parents of children with disability should be encouraged to form support group and as well as encouraging fathers of children with disability to take an active part in ensuring their children with disability well-being. More also, there is need to empower informal caregivers through training and education. More importantly governments at the three levels ( Federal, State and local) should assist caregivers at ensuring their own and that of their children with disability well-being through improvement on various existing social welfare services in the country.
- Full Text:
- Date Issued: 2014
Development of a bulbine frutescens and carpobrotus edulis cream in collaboration with african traditional healers of the Nelson Mandela Metropole
- Authors: Keele, Mbali Zamathiyane
- Date: 2014
- Subjects: Drug development -- South Africa -- Port Elizabeth , Healers -- South Africa -- Port Elizabeth , Traditional medicine -- South Africa -- Port Elizabeth , Physicians -- Health -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10358 , http://hdl.handle.net/10948/d1021016
- Description: Collaborations between researchers and African traditional healers on medicinal plants need to go beyond the flow of information from African traditional healers to researchers. Mutual beneficiation wherein African traditional healers reap rewards due to the information they possess is necessary and has been legislated in South Africa. The manner in which such beneficiation occurs and how it will be distributed should be subject to negotiation between (a) the researchers and holders of indigenous knowledge and (b) among holders of indigenous knowledge themselves. Beneficiation can be in the form of access to information, monetary or through shares in commercialised products, amongst others. African traditional healers involved in the collaboration with researchers of the Department of Biochemistry and Microbiology and the Department of Pharmacy at the Nelson Mandela Metropolitan University beneficiated by having access to knowledge and medicinal plants cultivated in the medicinal garden. Beneficiation was expected to extend to monetary gains from the sale of sewn garments and plants from a medicinal plants nursery which was to be developed and from a herbal topical product which was also to be developed. The aim of this research project was to develop a wound healing herbal cream consisting of Bulbine frutescens and Carpobrotus edulis as active ingredients. B. frutescens demonstrated better wound closure properties when compared to C. edulis and the combined extracts. The scratch assay wound was completely closed after 24 hours at B. frutescens concentrations of 5 μg/ml and 10 μg/ml. B. frutescens was more toxic to 3t3-L1 cells than C. edulis, but it was less toxic than the combined extracts. None of the extracts were toxic to Vero cells and the combined extracts significantly promoted their proliferation. Antibacterial activity of all the extracts was low. C. edulis showed antiviral activity against human herpes simplex virus 1 at 62.5, 125 and 250 μg/ml, while the combined extracts were active at 250 μg/ml. The combined extracts exhibited synergistic antioxidant activity. A reverse phase, gradient, high performance liquid chromatography method was developed and validated and used to conduct quality control tests on the extracts and the finished product. It was concluded that the use of whole chromatographic data instead of common peaks data is best for analysis of medicinal plants. The cream that was developed used buffered cream as the base and was stable at 25 °C/65 percent RH for one month with regard to organoleptic and rheological properties and microbial preservation.
- Full Text:
- Date Issued: 2014
- Authors: Keele, Mbali Zamathiyane
- Date: 2014
- Subjects: Drug development -- South Africa -- Port Elizabeth , Healers -- South Africa -- Port Elizabeth , Traditional medicine -- South Africa -- Port Elizabeth , Physicians -- Health -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10358 , http://hdl.handle.net/10948/d1021016
- Description: Collaborations between researchers and African traditional healers on medicinal plants need to go beyond the flow of information from African traditional healers to researchers. Mutual beneficiation wherein African traditional healers reap rewards due to the information they possess is necessary and has been legislated in South Africa. The manner in which such beneficiation occurs and how it will be distributed should be subject to negotiation between (a) the researchers and holders of indigenous knowledge and (b) among holders of indigenous knowledge themselves. Beneficiation can be in the form of access to information, monetary or through shares in commercialised products, amongst others. African traditional healers involved in the collaboration with researchers of the Department of Biochemistry and Microbiology and the Department of Pharmacy at the Nelson Mandela Metropolitan University beneficiated by having access to knowledge and medicinal plants cultivated in the medicinal garden. Beneficiation was expected to extend to monetary gains from the sale of sewn garments and plants from a medicinal plants nursery which was to be developed and from a herbal topical product which was also to be developed. The aim of this research project was to develop a wound healing herbal cream consisting of Bulbine frutescens and Carpobrotus edulis as active ingredients. B. frutescens demonstrated better wound closure properties when compared to C. edulis and the combined extracts. The scratch assay wound was completely closed after 24 hours at B. frutescens concentrations of 5 μg/ml and 10 μg/ml. B. frutescens was more toxic to 3t3-L1 cells than C. edulis, but it was less toxic than the combined extracts. None of the extracts were toxic to Vero cells and the combined extracts significantly promoted their proliferation. Antibacterial activity of all the extracts was low. C. edulis showed antiviral activity against human herpes simplex virus 1 at 62.5, 125 and 250 μg/ml, while the combined extracts were active at 250 μg/ml. The combined extracts exhibited synergistic antioxidant activity. A reverse phase, gradient, high performance liquid chromatography method was developed and validated and used to conduct quality control tests on the extracts and the finished product. It was concluded that the use of whole chromatographic data instead of common peaks data is best for analysis of medicinal plants. The cream that was developed used buffered cream as the base and was stable at 25 °C/65 percent RH for one month with regard to organoleptic and rheological properties and microbial preservation.
- Full Text:
- Date Issued: 2014
Development of an ionospheric map for Africa
- Authors: Ssessanga, Nicholas
- Date: 2014
- Subjects: Ionosondes Ionosphere Ionosphere -- Observations Ionosphere -- Research -- Africa Ionospheric electron density -- Africa Ionospheric critical frequencies
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5519 , http://hdl.handle.net/10962/d1011498
- Description: This thesis presents research pertaining to the development of an African Ionospheric Map (AIM). An ionospheric map is a computer program that is able to display spatial and temporal representations of ionospheric parameters such as, electron density and critical plasma frequencies, for every geographical location on the map. The purpose of this development was to make the most optimum use of all available data sources, namely ionosondes, satellites and models, and to implement error minimisation techniques in order to obtain the best result at any given location on the African continent. The focus was placed on the accurate estimation of three upper atmosphere parameters which are important for radio communications: critical frequency of the F2 layer (foF2), Total Electron Content (TEC) and the maximum usable frequency over a distance of 3000 km (M3000F2). The results show that AIM provided a more accurate estimation of the three parameters than the internationally recognised and recommended ionosphere model (IRI-2012) when used on its own. Therefore, the AIM is a more accurate solution than single independent data sources for applications requiring ionospheric mapping over the African continent.
- Full Text:
- Date Issued: 2014
- Authors: Ssessanga, Nicholas
- Date: 2014
- Subjects: Ionosondes Ionosphere Ionosphere -- Observations Ionosphere -- Research -- Africa Ionospheric electron density -- Africa Ionospheric critical frequencies
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5519 , http://hdl.handle.net/10962/d1011498
- Description: This thesis presents research pertaining to the development of an African Ionospheric Map (AIM). An ionospheric map is a computer program that is able to display spatial and temporal representations of ionospheric parameters such as, electron density and critical plasma frequencies, for every geographical location on the map. The purpose of this development was to make the most optimum use of all available data sources, namely ionosondes, satellites and models, and to implement error minimisation techniques in order to obtain the best result at any given location on the African continent. The focus was placed on the accurate estimation of three upper atmosphere parameters which are important for radio communications: critical frequency of the F2 layer (foF2), Total Electron Content (TEC) and the maximum usable frequency over a distance of 3000 km (M3000F2). The results show that AIM provided a more accurate estimation of the three parameters than the internationally recognised and recommended ionosphere model (IRI-2012) when used on its own. Therefore, the AIM is a more accurate solution than single independent data sources for applications requiring ionospheric mapping over the African continent.
- Full Text:
- Date Issued: 2014
Development of conservation methods for gunnera perpensa l.: an overexploited medicinal plant in the Eastern Cape, South Africa
- Authors: Chigor, Chinyere Blessing
- Date: 2014
- Subjects: Gunnera -- South Africa -- Eastern Cape , Medicinal plants -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Eastern Cape , Medical anthropology -- South Africa -- Eastern Cape , Medical policy -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD (Botany)
- Identifier: vital:11311 , http://hdl.handle.net/10353/d1019832 , Gunnera -- South Africa -- Eastern Cape , Medicinal plants -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Eastern Cape , Medical anthropology -- South Africa -- Eastern Cape , Medical policy -- South Africa -- Eastern Cape
- Description: South Africa, many plants which are used in traditional medicines are collected from wild populations. The high demand for trade and use of these medicinal plants place an enormous pressure on their natural populations, especially because they are indiscriminately harvested. The most affected of these plant species are those harvested from their underground parts, among which is Gunnera perpensa L. Gunnera perpensa is of considerable ethnobotanical interest in traditional medicine because of its wide usage. The rhizomes are widely used and indiscriminately collected in large quantities from the wild to meet the ever increasing demand in traditional medicine markets. As a result, this valuable medicinal plant species is being endangered. According to the Red List of South African Plants, the conservation status of G. perpensa has been listed as ‘declining’. The ethnobotanical survey conducted as part of this research confirms the plant species as threatened. It is, therefore, important to develop propagation and conservation strategies for this medicinal plant. Clonal propagation of G. perpensa was conducted using varying lengths of the rhizome (1, 2, 3, 4 and 5 cm) segments as propagules. While regeneration was possible with all the rhizome lengths, most of the growth parameters were significantly higher in the 5 cm rhizomes than the other rhizome segments. The appropriate planting depth for the rhizomes was also determined and 4 or 5 cm planting depths were found appropriate. No significant difference was observed in the growth parameters amongst the planting depths; nevertheless, 4 cm depth gave higher growth and yield. The results of this study show that regenerating G. perpensa.
- Full Text:
- Date Issued: 2014
- Authors: Chigor, Chinyere Blessing
- Date: 2014
- Subjects: Gunnera -- South Africa -- Eastern Cape , Medicinal plants -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Eastern Cape , Medical anthropology -- South Africa -- Eastern Cape , Medical policy -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD (Botany)
- Identifier: vital:11311 , http://hdl.handle.net/10353/d1019832 , Gunnera -- South Africa -- Eastern Cape , Medicinal plants -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Eastern Cape , Medical anthropology -- South Africa -- Eastern Cape , Medical policy -- South Africa -- Eastern Cape
- Description: South Africa, many plants which are used in traditional medicines are collected from wild populations. The high demand for trade and use of these medicinal plants place an enormous pressure on their natural populations, especially because they are indiscriminately harvested. The most affected of these plant species are those harvested from their underground parts, among which is Gunnera perpensa L. Gunnera perpensa is of considerable ethnobotanical interest in traditional medicine because of its wide usage. The rhizomes are widely used and indiscriminately collected in large quantities from the wild to meet the ever increasing demand in traditional medicine markets. As a result, this valuable medicinal plant species is being endangered. According to the Red List of South African Plants, the conservation status of G. perpensa has been listed as ‘declining’. The ethnobotanical survey conducted as part of this research confirms the plant species as threatened. It is, therefore, important to develop propagation and conservation strategies for this medicinal plant. Clonal propagation of G. perpensa was conducted using varying lengths of the rhizome (1, 2, 3, 4 and 5 cm) segments as propagules. While regeneration was possible with all the rhizome lengths, most of the growth parameters were significantly higher in the 5 cm rhizomes than the other rhizome segments. The appropriate planting depth for the rhizomes was also determined and 4 or 5 cm planting depths were found appropriate. No significant difference was observed in the growth parameters amongst the planting depths; nevertheless, 4 cm depth gave higher growth and yield. The results of this study show that regenerating G. perpensa.
- Full Text:
- Date Issued: 2014
Development of styrene based imprinted sorbents for selective clean-up of metalloporphyrins in organic media
- Authors: Awokoya, Kehinde Nurudeen
- Date: 2014
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54521 , vital:26580
- Description: Most crude oils contain traces of vanadium and nickel complex with porphyrins (VTPP and NTPP) within their asphaltene fraction. Although these metals are only present in trace quantities, they have a significant and detrimental impact on the refining process by degrading the quality of intermediate and end products. Therefore, their selective removal is highly desirable. This thesis presents the development of nickel porphyrin, nickel vanadyl porphyrin imprinted nanofibers and vanadyl porphyrin imprinted polymer (MIP) particles for application as selective sorbents. Computational model based on the combination of molecular dynamics simulations and quantum mechanics was successfully applied to the styrene functional monomer selection. The particle was prepared by bulk polymerization and the nanofibers by a novel approach combining molecular imprinting and electrospinning technology. The morphologies, thermal stabilities and porosities of the imprinted sorbents were studied using SEM, TGA, and BET nitrogen gas adsorption. Chloroform was found to swell the polymer particles to a higher degree than methanol and acetonitrile. The adsorption characteristics of the imprinted sorbents best fitted with Freundlich isotherm model. The imprinted sorbents recorded high extraction efficiencies (EEs) of > 99 % in selectively extracting the metalloporphyrins. The impact of the template on the affinity of recognition for NTPP was evaluated. The results showed that the NTPP adsorption capacity increased as the molar ratio of NTPP to styrene was increased from 1:1 to 3:1. The optimal ratio of template to functional monomer which yielded the best specific affinity and highest recovery (99.9 %) was 3:1. The effects of trifluoroacetic acid (TFA), dichloromethane (DCM), dimethyl sulphoxide (DMSO), pentane (PEN) on electro-spinnability of the polymer solutions and the morphological appearance of the nanofibers were investigated. The imprinted nanofibers exhibited the same selectivity specialism for both NTPP and VTPP. A remarkable stability in relation to reusability was observed when imprinted nanofibers were used, as they could be reused nine times without incurring any significant loss in removal efficiency. The results were validated by analysing a certified reference material. The imprinted sorbents were therefore found to be selective sorbents that are well suited for handling trace metals in organic media.
- Full Text:
- Date Issued: 2014
- Authors: Awokoya, Kehinde Nurudeen
- Date: 2014
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54521 , vital:26580
- Description: Most crude oils contain traces of vanadium and nickel complex with porphyrins (VTPP and NTPP) within their asphaltene fraction. Although these metals are only present in trace quantities, they have a significant and detrimental impact on the refining process by degrading the quality of intermediate and end products. Therefore, their selective removal is highly desirable. This thesis presents the development of nickel porphyrin, nickel vanadyl porphyrin imprinted nanofibers and vanadyl porphyrin imprinted polymer (MIP) particles for application as selective sorbents. Computational model based on the combination of molecular dynamics simulations and quantum mechanics was successfully applied to the styrene functional monomer selection. The particle was prepared by bulk polymerization and the nanofibers by a novel approach combining molecular imprinting and electrospinning technology. The morphologies, thermal stabilities and porosities of the imprinted sorbents were studied using SEM, TGA, and BET nitrogen gas adsorption. Chloroform was found to swell the polymer particles to a higher degree than methanol and acetonitrile. The adsorption characteristics of the imprinted sorbents best fitted with Freundlich isotherm model. The imprinted sorbents recorded high extraction efficiencies (EEs) of > 99 % in selectively extracting the metalloporphyrins. The impact of the template on the affinity of recognition for NTPP was evaluated. The results showed that the NTPP adsorption capacity increased as the molar ratio of NTPP to styrene was increased from 1:1 to 3:1. The optimal ratio of template to functional monomer which yielded the best specific affinity and highest recovery (99.9 %) was 3:1. The effects of trifluoroacetic acid (TFA), dichloromethane (DCM), dimethyl sulphoxide (DMSO), pentane (PEN) on electro-spinnability of the polymer solutions and the morphological appearance of the nanofibers were investigated. The imprinted nanofibers exhibited the same selectivity specialism for both NTPP and VTPP. A remarkable stability in relation to reusability was observed when imprinted nanofibers were used, as they could be reused nine times without incurring any significant loss in removal efficiency. The results were validated by analysing a certified reference material. The imprinted sorbents were therefore found to be selective sorbents that are well suited for handling trace metals in organic media.
- Full Text:
- Date Issued: 2014
Development of tourism diploma in IsiXhosa-speaking students' academic literacies : a multilingual intervention
- Authors: Batyi, Thokozile Thelma
- Date: 2014
- Subjects: Education, Bilingual -- South Africa -- Port Elizabeth , Language and languages -- Study and teaching -- South Africa -- Port Elizabeth , Education -- Study and teaching (Higher) -- South Africa -- Port Elizabeth , Multilingual communication -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:8369 , http://hdl.handle.net/10948/d1020194
- Description: In this study, it is argued that a bi/multilingual instruction is extremely beneficial for bi/multilingual students in higher education in South Africa. Since the adoption of democracy in 1994, cultural and linguistic diversity has become the norm in classrooms at Nelson Mandela Metropolitan University in Port Elizabeth. The testing of bi/multilingual strategies in this study (i.e. translation and development of multilingual glossaries; code-switching by tutor and students during teaching and learning; code-meshing by students online; and reading, speaking and writing bilingually), is an attempt to pedagogically adapt the curriculum to students’ needs. The data was collected from students in their Tourism Communication tutorial. The study was conducted in order to demonstrate that students benefit from bilingual pedagogies, which mobilise isiXhosa and English as languages of learning. Data was collected from tests, a questionnaire and interview, summaries, online discussions, written assignments and reflective journals in order to determine to what extent students’ performance was enhanced by bilingual tuition.
- Full Text:
- Date Issued: 2014
- Authors: Batyi, Thokozile Thelma
- Date: 2014
- Subjects: Education, Bilingual -- South Africa -- Port Elizabeth , Language and languages -- Study and teaching -- South Africa -- Port Elizabeth , Education -- Study and teaching (Higher) -- South Africa -- Port Elizabeth , Multilingual communication -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:8369 , http://hdl.handle.net/10948/d1020194
- Description: In this study, it is argued that a bi/multilingual instruction is extremely beneficial for bi/multilingual students in higher education in South Africa. Since the adoption of democracy in 1994, cultural and linguistic diversity has become the norm in classrooms at Nelson Mandela Metropolitan University in Port Elizabeth. The testing of bi/multilingual strategies in this study (i.e. translation and development of multilingual glossaries; code-switching by tutor and students during teaching and learning; code-meshing by students online; and reading, speaking and writing bilingually), is an attempt to pedagogically adapt the curriculum to students’ needs. The data was collected from students in their Tourism Communication tutorial. The study was conducted in order to demonstrate that students benefit from bilingual pedagogies, which mobilise isiXhosa and English as languages of learning. Data was collected from tests, a questionnaire and interview, summaries, online discussions, written assignments and reflective journals in order to determine to what extent students’ performance was enhanced by bilingual tuition.
- Full Text:
- Date Issued: 2014
Dialogic pedagogical innovation for liberating learning practices: a case of one programme in a higher education institution in South Africa
- Authors: Mudehwe, Florence Rutendo
- Date: 2014
- Subjects: Educational change -- South Africa , School improvement programs -- South Africa , Critical pedagogy , Curriculum evaluation -- South Africa , Education --Study and teaching
- Language: English
- Type: Thesis , Doctoral , PhD (Education)
- Identifier: vital:16225 , http://hdl.handle.net/10353/d1019737 , Educational change -- South Africa , School improvement programs -- South Africa , Critical pedagogy , Curriculum evaluation -- South Africa , Education --Study and teaching
- Description: The past two to three decades have seen unprecedented expansion in enrolments in Universities across the world. Increased participation rates in Higher Education, however, has not been matched by a corresponding increase in success rates as reflected in students' poor retention rates and unsatisfactory outcomes. One strand of explanation claims that students, for a variety of reasons, come to university `unprepared' and suffer an articulation gap in the transition between high school and university; the other explanation seeks to move away from the deficit perspective and puts emphasis on the need to enrich experiences of students to enable them to exercise agency and change constraining circumstances in order to succeed. This study reports on one programme, a grounding programme known as the Life, Knowledge and Action (LKA) in one South African university. One of the central purposes of the LKA is to enrich students' first year experiences through liberating dialogue embedded in its pedagogical architecture. A sequential mixed methods study was carried out. A survey of first year students who had been exposed to the LKA was first carried out. This was followed by a case study of purposively selected first year students. Findings show that LKA promoted dialogue in varied ways depending on the level of the pedagogical architecture. At Umzi level students as peers across disciplines exchanged ideas freely about their circumstances and social issues. At the Ekhaya level where the abakwezeli (facilitators) were active, power dynamics emerged between students and the facilitators which had the effect of diminishing dialogical moments. At village level, there was not much discussion; instead there was a lot of lecturing. Dialogue was limited to a few minutes of discussion at the end of the lecture. The other finding was that seen from Archer's lens of morphogenetic analysis, the `articulation gap' can be seen as a structural constraint, that can be addressed through liberating dialogue which enables the students to question the status quo. There was evidence that through dialogue in the LKA, students felt that it liberated them in the sense that it exposed them to different perspectives as well as enabled them to explore alternatives. It can be concluded that through an appropriately designed dialogical pedagogy, students can be empowered to transform the structural constraints to their education and create enablers that can help them succeed in their learning. There is evidence that within the LKA pedagogical architecture, the students have the opportunity to take responsibility for their learning and thus enabled to exercise agency. It is recommended that the processes that take place at each level of the LKA architecture must be further studied with a view to discovering mechanisms at work that may undermine the liberating thrust of the programme. As a liberating core curriculum, LKA must not be limited to first year students; consideration must be given to roll it out across the levels of the undergraduate offerings.
- Full Text:
- Date Issued: 2014
- Authors: Mudehwe, Florence Rutendo
- Date: 2014
- Subjects: Educational change -- South Africa , School improvement programs -- South Africa , Critical pedagogy , Curriculum evaluation -- South Africa , Education --Study and teaching
- Language: English
- Type: Thesis , Doctoral , PhD (Education)
- Identifier: vital:16225 , http://hdl.handle.net/10353/d1019737 , Educational change -- South Africa , School improvement programs -- South Africa , Critical pedagogy , Curriculum evaluation -- South Africa , Education --Study and teaching
- Description: The past two to three decades have seen unprecedented expansion in enrolments in Universities across the world. Increased participation rates in Higher Education, however, has not been matched by a corresponding increase in success rates as reflected in students' poor retention rates and unsatisfactory outcomes. One strand of explanation claims that students, for a variety of reasons, come to university `unprepared' and suffer an articulation gap in the transition between high school and university; the other explanation seeks to move away from the deficit perspective and puts emphasis on the need to enrich experiences of students to enable them to exercise agency and change constraining circumstances in order to succeed. This study reports on one programme, a grounding programme known as the Life, Knowledge and Action (LKA) in one South African university. One of the central purposes of the LKA is to enrich students' first year experiences through liberating dialogue embedded in its pedagogical architecture. A sequential mixed methods study was carried out. A survey of first year students who had been exposed to the LKA was first carried out. This was followed by a case study of purposively selected first year students. Findings show that LKA promoted dialogue in varied ways depending on the level of the pedagogical architecture. At Umzi level students as peers across disciplines exchanged ideas freely about their circumstances and social issues. At the Ekhaya level where the abakwezeli (facilitators) were active, power dynamics emerged between students and the facilitators which had the effect of diminishing dialogical moments. At village level, there was not much discussion; instead there was a lot of lecturing. Dialogue was limited to a few minutes of discussion at the end of the lecture. The other finding was that seen from Archer's lens of morphogenetic analysis, the `articulation gap' can be seen as a structural constraint, that can be addressed through liberating dialogue which enables the students to question the status quo. There was evidence that through dialogue in the LKA, students felt that it liberated them in the sense that it exposed them to different perspectives as well as enabled them to explore alternatives. It can be concluded that through an appropriately designed dialogical pedagogy, students can be empowered to transform the structural constraints to their education and create enablers that can help them succeed in their learning. There is evidence that within the LKA pedagogical architecture, the students have the opportunity to take responsibility for their learning and thus enabled to exercise agency. It is recommended that the processes that take place at each level of the LKA architecture must be further studied with a view to discovering mechanisms at work that may undermine the liberating thrust of the programme. As a liberating core curriculum, LKA must not be limited to first year students; consideration must be given to roll it out across the levels of the undergraduate offerings.
- Full Text:
- Date Issued: 2014
Digital storytelling to explore HIV- and AIDS- related stigma with secondary school learners in a rural community in KwaZulu-Natal
- Authors: Mnisi, Thoko Esther
- Date: 2014
- Subjects: AIDS (Disease) in adolescence -- Social aspects -- Africa, Southern , HIV infections -- Social aspects -- Africa, Southern , Stigma (Social psychology) -- South Africa -- KwaZulu-Natal , Digital storytelling
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9576 , http://hdl.handle.net/10948/d1018717
- Description: This study explores, through digital storytelling, the experiences of HIV- and AIDS-related stigma of rural community secondary school learners. HIV- and AIDS-related stigma is seen as an impediment to a proficient response to HIV and AIDS in communities, also rural communities, and requires addressing. The rural community in which the research is undertaken is particularly hard hit by HIV and AIDS. Learners’ experiences of HIV- and AIDS related stigma could therefore inform how school and community could engage with HIV- and AIDS-related stigma and how they could address it in a constructive way. The study attempts to respond to two research questions: What can digital storytelling reveal about secondary school learners’ experiences of HIV- and AIDS-related stigma in schools in a rural community? How can digital storytelling enable secondary school learners in school in a rural community to take action to address stigma? This qualitative study is positioned within a critical paradigm, and employs a community-based participatory research strategy. Twelve Grade 8 and 9 male and female learners aged 15 to 18 years, from two secondary schools in rural Vulindlela district of KwaZulu-Natal, South Africa, who experienced, witnessed or heard about HIV- and AIDS-related stigma participated. Digital storytelling, a visual participatory method, was used to generate the data, and this was complemented by group discussion and written pieces completed by the participants in reflection sessions. The thematic analysis of the data made use of participatory analysis: the analysis of the digital stories was done by the participants while the overarching analysis was done by the researcher. This study, located in the field of the Psychology of Education, is informed by the theoretical framework of symbolic interactionism. In terms of the experienced stigma, it was found that living with HIV and AIDS and the related stigma is perceived as a ‘hardship’. The stigma is experienced on many levels: in the family, at school, and from friends and members of the community. It has an impact on the individual on an intrapersonal and interpersonal level. The young person is caught up in a vicious cycle of silent suffering since there are no reliable and trustworthy people with whom he or she can share these challenges. Some so-called traditional beliefs and customs such as not talking about sex, and practices like virginity testing, also fuel HIV- and AIDS-related stigma. The use of derogatory terms and the severe criticism of early sexual debut along with the gossiping which is used to spread the stigmatising statements further complicate the hardship experienced by young people. Digital storytelling was found to not only enable the learners’ voices to be heard but also to enable their taking charge of the stigma and thus create the space for critical participation in this research. The implications for the study are that the pervasive stigma that young people experience should be addressed at every level of the community. The stakeholders such as the families, school, educators, the King (Inkosi) and Chiefs (Indunas) of the area, relevant departments with that of Education taking the lead, must work hand-in-hand with the affected young people. Such collaboration may allow for the identification of the problem, for reflection on it, and also for the addressing of it. HIV- and AIDS-related stigma, while it has changed since the emergence of HIV, still is an issue that many HIV-positive individuals have to contend with. This stigma is, however, contextual and how the individual is stigmatised fits in with the language, meaning and thought that a community constructs around stigma. While digital storytelling enables the uncovering of particular stories of stigma that learners experience in the context of a school in a rural community, the digital storytelling in and of itself enables a change in the language, meaning and thought around stigma in its drawing on the specifics of the stigma as experienced in the community. Also, digital storytelling is about sharing stories about, and experiences of HIV- and AIDS-related stigma and how these stories can be used as part of the solution. If such stories can be told, people can spread them just as gossip is spread, but in this case such spreading would work towards positive social change. I claim that in order to confront the challenges raised by the perpetuation of stigma, efforts must involve the communities and must tap into their own experiences of perpetuating or enduring stigmatisation. Suggestions by the very same people from the community who are at the front line of perpetuating and /or suffering the stigma must be considered. This may also become one way of instantly communicating the research findings back to the community involved in the research. Using digital storytelling can ensure getting self-tailored, contextual, specific views on how HIV- and AIDS-related stigma is experienced but also how it could be addressed.
- Full Text:
- Date Issued: 2014
- Authors: Mnisi, Thoko Esther
- Date: 2014
- Subjects: AIDS (Disease) in adolescence -- Social aspects -- Africa, Southern , HIV infections -- Social aspects -- Africa, Southern , Stigma (Social psychology) -- South Africa -- KwaZulu-Natal , Digital storytelling
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9576 , http://hdl.handle.net/10948/d1018717
- Description: This study explores, through digital storytelling, the experiences of HIV- and AIDS-related stigma of rural community secondary school learners. HIV- and AIDS-related stigma is seen as an impediment to a proficient response to HIV and AIDS in communities, also rural communities, and requires addressing. The rural community in which the research is undertaken is particularly hard hit by HIV and AIDS. Learners’ experiences of HIV- and AIDS related stigma could therefore inform how school and community could engage with HIV- and AIDS-related stigma and how they could address it in a constructive way. The study attempts to respond to two research questions: What can digital storytelling reveal about secondary school learners’ experiences of HIV- and AIDS-related stigma in schools in a rural community? How can digital storytelling enable secondary school learners in school in a rural community to take action to address stigma? This qualitative study is positioned within a critical paradigm, and employs a community-based participatory research strategy. Twelve Grade 8 and 9 male and female learners aged 15 to 18 years, from two secondary schools in rural Vulindlela district of KwaZulu-Natal, South Africa, who experienced, witnessed or heard about HIV- and AIDS-related stigma participated. Digital storytelling, a visual participatory method, was used to generate the data, and this was complemented by group discussion and written pieces completed by the participants in reflection sessions. The thematic analysis of the data made use of participatory analysis: the analysis of the digital stories was done by the participants while the overarching analysis was done by the researcher. This study, located in the field of the Psychology of Education, is informed by the theoretical framework of symbolic interactionism. In terms of the experienced stigma, it was found that living with HIV and AIDS and the related stigma is perceived as a ‘hardship’. The stigma is experienced on many levels: in the family, at school, and from friends and members of the community. It has an impact on the individual on an intrapersonal and interpersonal level. The young person is caught up in a vicious cycle of silent suffering since there are no reliable and trustworthy people with whom he or she can share these challenges. Some so-called traditional beliefs and customs such as not talking about sex, and practices like virginity testing, also fuel HIV- and AIDS-related stigma. The use of derogatory terms and the severe criticism of early sexual debut along with the gossiping which is used to spread the stigmatising statements further complicate the hardship experienced by young people. Digital storytelling was found to not only enable the learners’ voices to be heard but also to enable their taking charge of the stigma and thus create the space for critical participation in this research. The implications for the study are that the pervasive stigma that young people experience should be addressed at every level of the community. The stakeholders such as the families, school, educators, the King (Inkosi) and Chiefs (Indunas) of the area, relevant departments with that of Education taking the lead, must work hand-in-hand with the affected young people. Such collaboration may allow for the identification of the problem, for reflection on it, and also for the addressing of it. HIV- and AIDS-related stigma, while it has changed since the emergence of HIV, still is an issue that many HIV-positive individuals have to contend with. This stigma is, however, contextual and how the individual is stigmatised fits in with the language, meaning and thought that a community constructs around stigma. While digital storytelling enables the uncovering of particular stories of stigma that learners experience in the context of a school in a rural community, the digital storytelling in and of itself enables a change in the language, meaning and thought around stigma in its drawing on the specifics of the stigma as experienced in the community. Also, digital storytelling is about sharing stories about, and experiences of HIV- and AIDS-related stigma and how these stories can be used as part of the solution. If such stories can be told, people can spread them just as gossip is spread, but in this case such spreading would work towards positive social change. I claim that in order to confront the challenges raised by the perpetuation of stigma, efforts must involve the communities and must tap into their own experiences of perpetuating or enduring stigmatisation. Suggestions by the very same people from the community who are at the front line of perpetuating and /or suffering the stigma must be considered. This may also become one way of instantly communicating the research findings back to the community involved in the research. Using digital storytelling can ensure getting self-tailored, contextual, specific views on how HIV- and AIDS-related stigma is experienced but also how it could be addressed.
- Full Text:
- Date Issued: 2014
Direct and indirect effects of zooplanktivorous predators on the estuarine plankton community
- Authors: Wasserman, Ryan John
- Date: 2014
- Subjects: Zooplankton -- Effect of predation on , Predation (Biology) , Zooplankton -- Predators of , Copepoda
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5870 , http://hdl.handle.net/10962/d1012938
- Description: Although predation has been identified as a potentially important driver in terrestrial and freshwater ecosystems, estuarine planktonic research has focused largely on the so-called "bottom-up" drivers of community assemblages. As such, this thesis focuses on the direct and indirect effects of zooplanktivorous predators on the planktonic community in an estuarine environment. By using a suite of in situ mesocosm experiments, a number of hypotheses, pertaining to the major research themes associated with predator-prey interactions, are tested. These themes included trophic cascading, risk effects associated with predation events and the importance of predator diversity in maintaining prey communities. The first experiment assessed the significance of apex predation pressure for the planktonic community through trophic cascades. Various treatments using in situ mesocosms were established in a closed oligotrophic estuary to highlight the importance of predation in stabilising estuarine plankton abundances. Through either the removal (filtration) or addition of certain planktonic groups, varied trophic scenarios were established. The experimental treatment containing apex zooplanktivores had consequences for multiple trophic levels, exerting a stabilising pressure throughout the food web (Chapter 3). Furthermore, pyrosequencing of filtered water samples revealed that when compared to the remaining treatments, the treatment containing stable apex predatory pressure experienced limited temporal deviation-from-initial in bacterial community structure (Chapter 4). These findings are consistent with trophic cascade theory whereby predators mediate interactions at multiple lower trophic levels with consequent repercussions for diversity. To assess the non-consumptive effects of predators on prey, two experiments were conducted. Firstly, using egg numbers per clutch as a measure of potential reproductive output, the non-lethal effects of predatory pressure on reproductive success in a key planktonic copepod was investigated. In this study, the average clutch size of fecund female copepods was found to be consistently lower in the presence of predators when compared to females not exposed to predation threat (Chapter 5). The second study assessed the effects of conspecific chemical alarm cues associated with predation, on population dynamics of a copepod species. This study revealed that the copepods appear to detect the presence of chemical alarm cues associated with predation events, with repercussions for population demographics over time. Furthermore, it showed that in the absence of actual predation, copepod prey responses to alarm cues were adjusted over time, consistent with the threat sensitive predator avoidance hypothesis (Chapter 6). The final data chapter dealt with predator diversity and its implications for zooplankton community structure. By experimentally monitoring the effects of two alternate model predators on the metazoan community over time, dissimilarities in community level control emerged. Alternate key prey populations were regulated by the different model predators, highlighting the importance of predator and prey behaviour in mediating predator-prey interactions (Chapter 7). These results highlight the potential importance of predators in maintaining community dynamics in estuarine planktonic communities under certain conditions. This study represents some of the first work to address these various aspects of predator-prey dynamics within the context of planktonic estuarine ecology.
- Full Text:
- Date Issued: 2014
- Authors: Wasserman, Ryan John
- Date: 2014
- Subjects: Zooplankton -- Effect of predation on , Predation (Biology) , Zooplankton -- Predators of , Copepoda
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5870 , http://hdl.handle.net/10962/d1012938
- Description: Although predation has been identified as a potentially important driver in terrestrial and freshwater ecosystems, estuarine planktonic research has focused largely on the so-called "bottom-up" drivers of community assemblages. As such, this thesis focuses on the direct and indirect effects of zooplanktivorous predators on the planktonic community in an estuarine environment. By using a suite of in situ mesocosm experiments, a number of hypotheses, pertaining to the major research themes associated with predator-prey interactions, are tested. These themes included trophic cascading, risk effects associated with predation events and the importance of predator diversity in maintaining prey communities. The first experiment assessed the significance of apex predation pressure for the planktonic community through trophic cascades. Various treatments using in situ mesocosms were established in a closed oligotrophic estuary to highlight the importance of predation in stabilising estuarine plankton abundances. Through either the removal (filtration) or addition of certain planktonic groups, varied trophic scenarios were established. The experimental treatment containing apex zooplanktivores had consequences for multiple trophic levels, exerting a stabilising pressure throughout the food web (Chapter 3). Furthermore, pyrosequencing of filtered water samples revealed that when compared to the remaining treatments, the treatment containing stable apex predatory pressure experienced limited temporal deviation-from-initial in bacterial community structure (Chapter 4). These findings are consistent with trophic cascade theory whereby predators mediate interactions at multiple lower trophic levels with consequent repercussions for diversity. To assess the non-consumptive effects of predators on prey, two experiments were conducted. Firstly, using egg numbers per clutch as a measure of potential reproductive output, the non-lethal effects of predatory pressure on reproductive success in a key planktonic copepod was investigated. In this study, the average clutch size of fecund female copepods was found to be consistently lower in the presence of predators when compared to females not exposed to predation threat (Chapter 5). The second study assessed the effects of conspecific chemical alarm cues associated with predation, on population dynamics of a copepod species. This study revealed that the copepods appear to detect the presence of chemical alarm cues associated with predation events, with repercussions for population demographics over time. Furthermore, it showed that in the absence of actual predation, copepod prey responses to alarm cues were adjusted over time, consistent with the threat sensitive predator avoidance hypothesis (Chapter 6). The final data chapter dealt with predator diversity and its implications for zooplankton community structure. By experimentally monitoring the effects of two alternate model predators on the metazoan community over time, dissimilarities in community level control emerged. Alternate key prey populations were regulated by the different model predators, highlighting the importance of predator and prey behaviour in mediating predator-prey interactions (Chapter 7). These results highlight the potential importance of predators in maintaining community dynamics in estuarine planktonic communities under certain conditions. This study represents some of the first work to address these various aspects of predator-prey dynamics within the context of planktonic estuarine ecology.
- Full Text:
- Date Issued: 2014
Ecological consequences of non-native fish invasion in Eastern Cape headwater streams
- Authors: Ellender, Bruce Robert
- Date: 2014
- Subjects: Fishery management -- South Africa -- Eastern Cape Fishes -- Conservation -- South Africa Introduced fishes -- South Africa -- Eastern Cape Introduced organisms
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/69065 , vital:29380
- Description: The introduction, spread and concomitant impacts of non-native species are a global problem. Fish are among the most widely introduced vertebrate groups, with their impacts affecting multiple levels of organisation- from individuals, populations and communities, to entire ecosystems. In South Africa, the largest perceived threat to range-restricted endemic headwater stream fishes is said to be invasion by non-native fishes, however, as is the case elsewhere, invasive impacts are often a case of risk perception rather than actual risk analysis. Two range-restricted headwater species, the Eastern Cape redfin Pseudobarbus afer and the Border barb Barbus trevelyani are redlisted by the International Union for the Conservation of Nature (IUCN) as ‘Endangered’, primarily due to invasion by non-native fishes. To investigate invasions in South Africa, and provide a quantitative estimate of the impact of non-native fishes on the two imperilled endemics, P. afer and B. trevelyani, the overall aims of this thesis were to: (A) Provide a literature review on non-native fish invasions in South Africa; (B) Using two case studies on the headwaters of the perennial Keiskamma and episodic Swartkops River systems, investigate the naturalisation-invasion continuum to provide a holistic view of the invasion process in these variable environments. The specific thesis objectives were: (1) Reviewing current knowledge of invasive impacts of non-native fishes in South Africa; (2) Investigating invasibility of headwater stream environments by non-native fishes; (3) Determining the establishment success of non-native fishes, (4) Assessing the spatial and temporal impacts of invasion; (5) Understanding mechanisms responsible for non-native fish impacts; (6) Investigating the threat of non-native fish invasion on the genetic diversity of two the two headwater fishes, P. afer and B. trevelyani. Results from the literature review of fish invasions (Chapter 1) showed that South Africa has a long history of non-native fish introductions, spanning two and a half centuries. Currently, 55 species have been introduced or translocated. Many of these introduced species have become fully invasive (36%). Their impacts also span multiple levels of biological organisation. There was a general paucity of studies on fish invasions (38 studies), however, of those conducted, reviewed studies placed emphases on invasive impacts (25 studies) and the transport, introduction, establishment and spread stages of the invasion process were largely ignored. The two study systems, the Swartkops and Keiskamma Rivers, were heavily invaded and numbers of introduced species surpassed that of natives (Chapter 2, 3 and 5). Headwater streams had varying invasibility and a number of non-native species were successfully established (Chapter 2, 3, 5 and 6). The remainder of the invasions were casual incursions into headwater streams from source populations in mainstream and impoundment environments which were invasion hotspots. Irrespective of establishment, four predatory invaders (largemouth bass Micropterus salmoides, smallmouth bass M. dolomieu, brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss) impacted heavily on native fish communities (Chapter 3, 4 and 5). Two broad types of invasion were documented, top down invasion by non-native O. mykiss and S. trutta and upstream invasion by M. salmoides and M. dolomieu (Chapter 3 and 5). Their impacts included changes in community structure, extirpation from invaded stream reaches resulting in contracted distribution, and isolation and fragmentation of native fish populations. The impacts of non-native predatory fishes were particularly acute for P. afer and B. trevelyani. Where non-native predatory fish occurred, P. afer and B. trevelyani had been extirpated (Chapter 3 and 5). As a result both native species exhibited contracted distributions (>20% habitat loss due to invasion). Upstream invasion by centrarchids isolated and fragmented P. afer populations into headwater refugia, while top down invasion by salmonids excluded B. trevelyani from invaded, more pristine stream reaches, by forcing the species into degraded unsuitable lower stream reaches. Predation also disrupted population processes such as adult dispersal for P. afer, and centrarchid-invaded zones acted as demographic sinks, where adults dispersing through invaded reaches were rapidly depleted. While the Mandela lineage of P. afer exhibited little within or between drainage genetic structuring, B. trevelyani was >4% divergent between drainages, and up to 2% divergent between streams within the Keiskamma River system (Chapter 7). The distribution of genetic diversity for B. trevelyani also indicated that the loss of diversity was imminent without immediate conservation interventions. This thesis has provided conclusive evidence that native fishes are vulnerable to invasion and that non-native predatory fishes have significant impacts on native fishes in Eastern Cape headwater streams. If management and conservation measures are implemented, the unwanted introduction and spread of non-native fishes may be restricted, allowing native fishes opportunities for recovery.
- Full Text:
- Date Issued: 2014
- Authors: Ellender, Bruce Robert
- Date: 2014
- Subjects: Fishery management -- South Africa -- Eastern Cape Fishes -- Conservation -- South Africa Introduced fishes -- South Africa -- Eastern Cape Introduced organisms
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/69065 , vital:29380
- Description: The introduction, spread and concomitant impacts of non-native species are a global problem. Fish are among the most widely introduced vertebrate groups, with their impacts affecting multiple levels of organisation- from individuals, populations and communities, to entire ecosystems. In South Africa, the largest perceived threat to range-restricted endemic headwater stream fishes is said to be invasion by non-native fishes, however, as is the case elsewhere, invasive impacts are often a case of risk perception rather than actual risk analysis. Two range-restricted headwater species, the Eastern Cape redfin Pseudobarbus afer and the Border barb Barbus trevelyani are redlisted by the International Union for the Conservation of Nature (IUCN) as ‘Endangered’, primarily due to invasion by non-native fishes. To investigate invasions in South Africa, and provide a quantitative estimate of the impact of non-native fishes on the two imperilled endemics, P. afer and B. trevelyani, the overall aims of this thesis were to: (A) Provide a literature review on non-native fish invasions in South Africa; (B) Using two case studies on the headwaters of the perennial Keiskamma and episodic Swartkops River systems, investigate the naturalisation-invasion continuum to provide a holistic view of the invasion process in these variable environments. The specific thesis objectives were: (1) Reviewing current knowledge of invasive impacts of non-native fishes in South Africa; (2) Investigating invasibility of headwater stream environments by non-native fishes; (3) Determining the establishment success of non-native fishes, (4) Assessing the spatial and temporal impacts of invasion; (5) Understanding mechanisms responsible for non-native fish impacts; (6) Investigating the threat of non-native fish invasion on the genetic diversity of two the two headwater fishes, P. afer and B. trevelyani. Results from the literature review of fish invasions (Chapter 1) showed that South Africa has a long history of non-native fish introductions, spanning two and a half centuries. Currently, 55 species have been introduced or translocated. Many of these introduced species have become fully invasive (36%). Their impacts also span multiple levels of biological organisation. There was a general paucity of studies on fish invasions (38 studies), however, of those conducted, reviewed studies placed emphases on invasive impacts (25 studies) and the transport, introduction, establishment and spread stages of the invasion process were largely ignored. The two study systems, the Swartkops and Keiskamma Rivers, were heavily invaded and numbers of introduced species surpassed that of natives (Chapter 2, 3 and 5). Headwater streams had varying invasibility and a number of non-native species were successfully established (Chapter 2, 3, 5 and 6). The remainder of the invasions were casual incursions into headwater streams from source populations in mainstream and impoundment environments which were invasion hotspots. Irrespective of establishment, four predatory invaders (largemouth bass Micropterus salmoides, smallmouth bass M. dolomieu, brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss) impacted heavily on native fish communities (Chapter 3, 4 and 5). Two broad types of invasion were documented, top down invasion by non-native O. mykiss and S. trutta and upstream invasion by M. salmoides and M. dolomieu (Chapter 3 and 5). Their impacts included changes in community structure, extirpation from invaded stream reaches resulting in contracted distribution, and isolation and fragmentation of native fish populations. The impacts of non-native predatory fishes were particularly acute for P. afer and B. trevelyani. Where non-native predatory fish occurred, P. afer and B. trevelyani had been extirpated (Chapter 3 and 5). As a result both native species exhibited contracted distributions (>20% habitat loss due to invasion). Upstream invasion by centrarchids isolated and fragmented P. afer populations into headwater refugia, while top down invasion by salmonids excluded B. trevelyani from invaded, more pristine stream reaches, by forcing the species into degraded unsuitable lower stream reaches. Predation also disrupted population processes such as adult dispersal for P. afer, and centrarchid-invaded zones acted as demographic sinks, where adults dispersing through invaded reaches were rapidly depleted. While the Mandela lineage of P. afer exhibited little within or between drainage genetic structuring, B. trevelyani was >4% divergent between drainages, and up to 2% divergent between streams within the Keiskamma River system (Chapter 7). The distribution of genetic diversity for B. trevelyani also indicated that the loss of diversity was imminent without immediate conservation interventions. This thesis has provided conclusive evidence that native fishes are vulnerable to invasion and that non-native predatory fishes have significant impacts on native fishes in Eastern Cape headwater streams. If management and conservation measures are implemented, the unwanted introduction and spread of non-native fishes may be restricted, allowing native fishes opportunities for recovery.
- Full Text:
- Date Issued: 2014
Efficacy of two medical plant extracts and metformin in the prevention of diet induced fatty liver
- Tshidino, Shonisani Cathphonia
- Authors: Tshidino, Shonisani Cathphonia
- Date: 2014
- Subjects: Plant Extracts -- Therapeutic use , Medicinal plants
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/9066 , vital:26461
- Description: Non‐alcoholic fatty liver diseases (NAFLD) is manifested in the absent of alcohol abuse. This disease is the major cause of liver failure and death among adults and children worldwide, including South Africa. Its increasing prevalence urges the need of therapeutic intervention. The main objectives of this study were to investigate the following: (1) The effect of 38.9% high fat diet (HFD)‐induced insulin resistance and fatty liver in male Wistar rats, (2) The efficacy of aqueous extracts from Sutherlandia frutescens leaves and Prunus africana bark and metformin in the treatment of HFDinduced insulin resistance and fatty liver. Male Wistar rats were fed on HFD (the HF group) or normal rat chow (the LF group) for 12 weeks. Even though the HFD‐fed rats had developed insulin resistance by week 12, fatty liver developed by week 16. After week 12, the HF group was divided into four groups of 6‐7 rats each and three of those groups were gavaged with either 0.125 mg P. africana extract/kg bwt/day (the HF+Pa group) or 50 mg S. frutescens extract kg bwt/day (the HF+Sf group) or 16 mg metformin/ kg bwt/day (HF+Met group), while kept on the same diet for an additional of 4 weeks, to investigate whether two medicinal plant extracts and metformin can prevent HFD to induce fatty liver or not. After 16 weeks, the liver histological images revealed that the HF group developed fatty liver in the form of both microsteatosis and macrosteatosis. Fatty liver was confirmed by significant increased liver total lipid (TL) and activities of glucose‐6‐phosphate dehydrogenase (cG6PD) and xanthine oxidase (XO), mitochondrial NADH oxidase (mNOX) and by a decrease (P<0.05) in the activities of the homogenate superoxide dismutase (hSOD) and mitochondrial complex II in the HF group, when compared to the LF group. Since the activities of mCS and cACL enzymes were not changed in the HF group, hence increased cG6PD activity in the HF group indicates that there was increased NADPH demand for lipid accumulation from activated NEFAs taken up by the liver from circulation and for maintenance of the NADPH‐dependent antioxidants and oxidants, respectively. The obtained data also show that mitochondria of the HFD‐fed rats adapted to an increase in energy availability, thereby compensation through decreasing complex II activity, to allow electron flux from β‐oxidation to respiratory chain in the HF group. Liver TL content was significantly decreased in the rats treated with metformin and P. africana extract, but not in the rats treated with S. frutescens when compared to the HF group (P < 0.05). However, the TL content remained >5% per liver weight in all treated groups. The present study demonstrates that these two plant extracts and metformin have different glucogenic and lipogenic effects from that presented by HFD alone when compared to the LFD alone. In conclusion, metformin and P. africana extract can attenuate HFD‐induced fatty liver without changing the dietary habits. Hence S. frutescens extract is less effective in the prevention of HFD‐induced fatty liver. A change in the dietary habits is recommended to be considered during the use of these three remedies in the treatment of HFD‐induced insulin resistance and fatty liver. All three treatments enhanced antioxidant capacity, and may improve insulin resistance and fatty liver mediated by the present HFD through different mechanism of actions in the liver.
- Full Text:
- Date Issued: 2014
- Authors: Tshidino, Shonisani Cathphonia
- Date: 2014
- Subjects: Plant Extracts -- Therapeutic use , Medicinal plants
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/9066 , vital:26461
- Description: Non‐alcoholic fatty liver diseases (NAFLD) is manifested in the absent of alcohol abuse. This disease is the major cause of liver failure and death among adults and children worldwide, including South Africa. Its increasing prevalence urges the need of therapeutic intervention. The main objectives of this study were to investigate the following: (1) The effect of 38.9% high fat diet (HFD)‐induced insulin resistance and fatty liver in male Wistar rats, (2) The efficacy of aqueous extracts from Sutherlandia frutescens leaves and Prunus africana bark and metformin in the treatment of HFDinduced insulin resistance and fatty liver. Male Wistar rats were fed on HFD (the HF group) or normal rat chow (the LF group) for 12 weeks. Even though the HFD‐fed rats had developed insulin resistance by week 12, fatty liver developed by week 16. After week 12, the HF group was divided into four groups of 6‐7 rats each and three of those groups were gavaged with either 0.125 mg P. africana extract/kg bwt/day (the HF+Pa group) or 50 mg S. frutescens extract kg bwt/day (the HF+Sf group) or 16 mg metformin/ kg bwt/day (HF+Met group), while kept on the same diet for an additional of 4 weeks, to investigate whether two medicinal plant extracts and metformin can prevent HFD to induce fatty liver or not. After 16 weeks, the liver histological images revealed that the HF group developed fatty liver in the form of both microsteatosis and macrosteatosis. Fatty liver was confirmed by significant increased liver total lipid (TL) and activities of glucose‐6‐phosphate dehydrogenase (cG6PD) and xanthine oxidase (XO), mitochondrial NADH oxidase (mNOX) and by a decrease (P<0.05) in the activities of the homogenate superoxide dismutase (hSOD) and mitochondrial complex II in the HF group, when compared to the LF group. Since the activities of mCS and cACL enzymes were not changed in the HF group, hence increased cG6PD activity in the HF group indicates that there was increased NADPH demand for lipid accumulation from activated NEFAs taken up by the liver from circulation and for maintenance of the NADPH‐dependent antioxidants and oxidants, respectively. The obtained data also show that mitochondria of the HFD‐fed rats adapted to an increase in energy availability, thereby compensation through decreasing complex II activity, to allow electron flux from β‐oxidation to respiratory chain in the HF group. Liver TL content was significantly decreased in the rats treated with metformin and P. africana extract, but not in the rats treated with S. frutescens when compared to the HF group (P < 0.05). However, the TL content remained >5% per liver weight in all treated groups. The present study demonstrates that these two plant extracts and metformin have different glucogenic and lipogenic effects from that presented by HFD alone when compared to the LFD alone. In conclusion, metformin and P. africana extract can attenuate HFD‐induced fatty liver without changing the dietary habits. Hence S. frutescens extract is less effective in the prevention of HFD‐induced fatty liver. A change in the dietary habits is recommended to be considered during the use of these three remedies in the treatment of HFD‐induced insulin resistance and fatty liver. All three treatments enhanced antioxidant capacity, and may improve insulin resistance and fatty liver mediated by the present HFD through different mechanism of actions in the liver.
- Full Text:
- Date Issued: 2014
Electrospun fiber based colorimetric probes for aspartate aminotransferase and I7ß-estradiol
- Authors: Pule, Bellah Oreeditse
- Date: 2014
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54869 , vital:26623
- Description: Fabrication, characterization and application of electrospun polymer composite based colorimetric probes are presented in this thesis. The first part of the thesis involved the development of a protocol for in situ reduction of gold trication (Au³+) into metallic gold atoms with sodium borohydride. The prepared PS-Au NPs showed an SPR band at 542 nm. Furthermore the absorbance of the colloidal Au NPs in polystyrene exhibited a good linear correlation (r2 = 0.9934) to E2 concentration in the range 5 to 50 ppb. The lowest naked eye detection limit was found to be 0.5 ppb and could further be easily monitored by UV-vis spectrophotometer. Upon interaction with E2 Au NPs aggregated to give nanoparticle clusters, confirmed through TEM analysis. Different concentrations of Au NPs were found to have a significant effect on the conductivity of the PS-Au NPs solution. At low concentrations of Au NPs (0.002, 0.015 and 0.025% w/v) PS-Au NPs solution could be electrospun without clogging. The FE-SEM images showed a non-beaded morphology of PS-Au NPs composite fibers. Upon interaction of the colorimetric probe strips with various E2 concentrations it was observed that with increasing E2 concentrations (50 ng/ml to 1000 µg/ml) the colour of the probe changed gradually from white to shades of pink and eventually to shades of blue at higher E2 concentrations. The visible cut-off concentration was 100 ng/ml. The second component of the thesis focussed on the development of diazonium dye-nylon 6 colorimetric probe for aspartate aminotransferase. At optimal pH 7.4 the enzyme was stable, highly active and catalyzed a reaction that was susceptible to detailed kinetic analysis by continuous optical methods. The KM values for L-aspartate, a- ketoglutarate and oxaloacetate were 2.60, 0.59 and 0.066 mM, respectively. On the basis of these KM values the solid-state colorimetric probe was developed. A colour change occurred when an electrospun dye-N 6 probes were exposed to visibly detectable concentrations of oxaloacetate, an AST-catalyzed reaction product. While monitoring AST activity at 530 run, a linear relation was obtained between oxaloacetate concentrations ranging from 0.4 - 7.4 µg/ml. Naked eye detection limit of 2.4 µg/ml oxalaoacetate equivalence of 10 times the normal AST activity was attained. The colorimetric probe was in addition, tested against co-substrates aspartate, ketoglutarate and a variety of other compounds such as alanine, pryruvate, as well as glutamic, malaic and succinic acids known to interfere with AST activity. Each compound elicited a distinct and unambiguous colour change upon interaction with the colorimetric probe. Further X-ray powder diffraction (XRD), duNouy ring tensiometer, Brunauer- Emmett- Teller (BET) and energy dispersive X-ray spectroscopy (EDS/EDX) characterization confirmed composition and stability of the colorimetric probes. Colorimetric probes developed in this thesis are relatively cost effective, simple and "rugged" for measurement of analytes with visual detection without sample pretreatment in matrices, such as plasma and dairy effluents. The probes warrant further investigation as they have shown potential and offer a promising solid-state platform for both clinical diagnostics and environmental monitoring.
- Full Text:
- Date Issued: 2014
- Authors: Pule, Bellah Oreeditse
- Date: 2014
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54869 , vital:26623
- Description: Fabrication, characterization and application of electrospun polymer composite based colorimetric probes are presented in this thesis. The first part of the thesis involved the development of a protocol for in situ reduction of gold trication (Au³+) into metallic gold atoms with sodium borohydride. The prepared PS-Au NPs showed an SPR band at 542 nm. Furthermore the absorbance of the colloidal Au NPs in polystyrene exhibited a good linear correlation (r2 = 0.9934) to E2 concentration in the range 5 to 50 ppb. The lowest naked eye detection limit was found to be 0.5 ppb and could further be easily monitored by UV-vis spectrophotometer. Upon interaction with E2 Au NPs aggregated to give nanoparticle clusters, confirmed through TEM analysis. Different concentrations of Au NPs were found to have a significant effect on the conductivity of the PS-Au NPs solution. At low concentrations of Au NPs (0.002, 0.015 and 0.025% w/v) PS-Au NPs solution could be electrospun without clogging. The FE-SEM images showed a non-beaded morphology of PS-Au NPs composite fibers. Upon interaction of the colorimetric probe strips with various E2 concentrations it was observed that with increasing E2 concentrations (50 ng/ml to 1000 µg/ml) the colour of the probe changed gradually from white to shades of pink and eventually to shades of blue at higher E2 concentrations. The visible cut-off concentration was 100 ng/ml. The second component of the thesis focussed on the development of diazonium dye-nylon 6 colorimetric probe for aspartate aminotransferase. At optimal pH 7.4 the enzyme was stable, highly active and catalyzed a reaction that was susceptible to detailed kinetic analysis by continuous optical methods. The KM values for L-aspartate, a- ketoglutarate and oxaloacetate were 2.60, 0.59 and 0.066 mM, respectively. On the basis of these KM values the solid-state colorimetric probe was developed. A colour change occurred when an electrospun dye-N 6 probes were exposed to visibly detectable concentrations of oxaloacetate, an AST-catalyzed reaction product. While monitoring AST activity at 530 run, a linear relation was obtained between oxaloacetate concentrations ranging from 0.4 - 7.4 µg/ml. Naked eye detection limit of 2.4 µg/ml oxalaoacetate equivalence of 10 times the normal AST activity was attained. The colorimetric probe was in addition, tested against co-substrates aspartate, ketoglutarate and a variety of other compounds such as alanine, pryruvate, as well as glutamic, malaic and succinic acids known to interfere with AST activity. Each compound elicited a distinct and unambiguous colour change upon interaction with the colorimetric probe. Further X-ray powder diffraction (XRD), duNouy ring tensiometer, Brunauer- Emmett- Teller (BET) and energy dispersive X-ray spectroscopy (EDS/EDX) characterization confirmed composition and stability of the colorimetric probes. Colorimetric probes developed in this thesis are relatively cost effective, simple and "rugged" for measurement of analytes with visual detection without sample pretreatment in matrices, such as plasma and dairy effluents. The probes warrant further investigation as they have shown potential and offer a promising solid-state platform for both clinical diagnostics and environmental monitoring.
- Full Text:
- Date Issued: 2014
Electrospun fibre based colorimetric probes for biological molecules
- Authors: Mudabuka, Boitumelo
- Date: 2014
- Subjects: Nanofibers , Vitamin C , Dopamine
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4535 , http://hdl.handle.net/10962/d1016354
- Description: The thesis reports the use of electrospun nanofibres as a platform for the development of colorimetric probes. Three colorimetric probes in the form of electrospun nanofibre test strips were developed for the selective detection of ascorbic acid and dopamine because they are crucial biomolecules for physiological processes in human metabolism and usually coexist in biological samples. The simultaneous detection of the biomolecules is very important as their abnormal concentration levels would lead to diseases such as Parkinson's and schizophrenia. Different methods of incorporating detector agents into the nanofibre were exploited for the detection of the biomolecules. The methods included physical incorporation of nanoparticles, covalent bonding of ligand/dyes through surface modification of the fibres. The first colorimetric test strip for ascorbic acid was based on copper-gold alloy nanoparticles prepared in-situ and hosted in nylon6. The test strip showed selectivity in detecting ascorbic acid in the pH range 2 – 7. The suitability of fibres in hosting copper-gold alloy nanoparticles for the colorimetric detection of ascorbic acid was investigated using nylon6, poly(vinyl benzyl chloride)-styrene and cellulose acetate based test strips. All the test strips exhibited leaching and the nylon6 based test strip was found to be thermally stable up to 60 ˚C. The colorimetric performance of the test strips was maintained and neither was colour decay exhibited after 10 months of storage in a shelf. The test strip achieved an eye-ball limit of detection of 1.76 x10-2 mg L-1 and its suitability was demonstrated by the determination of ascorbic acid in fruit juices, urine, serum, and vitamin C tablets. The second colorimetric test strip for ascorbic acid and dopamine employed prussian blue synthesised in-situ in nylon6. Ascorbic acid turned the deep blue test strip to light blue at pH 3, and a faded navy blue colour at a pH range of 6 - 7 while dopamine changed the strip to purple at the same pH range. The versatility of the test strip was demonstrated by detecting ascorbic acid in commercial fruit juices as well as by detecting ascorbic acid as well as dopamine in fortified urine. The eye-ball detection limit of the Prussian blue test strip for ascorbic acid and dopamine was 17.6 mg L-1 and 18.9 mg L-1, respectively. The third method involved a covalent approach, where poly(vinylbenzyl chloride) nanofibers were post functionalised with 2-(2′-pyridyl)-imidazole and iron(III) for the selective detection of ascorbic acid and dopamine. The eye-ball detection limit for ascorbic acid and dopamine was 17.6 mg L-1 and 18.9 mg L-1, respectively. The test strip was selective for dopamine, but the detection of ascorbic acid suffered from interference by glutathione. The application of the test strips was nevertheless demonstrated by the detection of ascorbic acid in fruit juices and dopamine in fortified urine. The developed test strips employing the three approaches were applied without sample pre-treatment and use of supporting equipment.
- Full Text:
- Date Issued: 2014
- Authors: Mudabuka, Boitumelo
- Date: 2014
- Subjects: Nanofibers , Vitamin C , Dopamine
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4535 , http://hdl.handle.net/10962/d1016354
- Description: The thesis reports the use of electrospun nanofibres as a platform for the development of colorimetric probes. Three colorimetric probes in the form of electrospun nanofibre test strips were developed for the selective detection of ascorbic acid and dopamine because they are crucial biomolecules for physiological processes in human metabolism and usually coexist in biological samples. The simultaneous detection of the biomolecules is very important as their abnormal concentration levels would lead to diseases such as Parkinson's and schizophrenia. Different methods of incorporating detector agents into the nanofibre were exploited for the detection of the biomolecules. The methods included physical incorporation of nanoparticles, covalent bonding of ligand/dyes through surface modification of the fibres. The first colorimetric test strip for ascorbic acid was based on copper-gold alloy nanoparticles prepared in-situ and hosted in nylon6. The test strip showed selectivity in detecting ascorbic acid in the pH range 2 – 7. The suitability of fibres in hosting copper-gold alloy nanoparticles for the colorimetric detection of ascorbic acid was investigated using nylon6, poly(vinyl benzyl chloride)-styrene and cellulose acetate based test strips. All the test strips exhibited leaching and the nylon6 based test strip was found to be thermally stable up to 60 ˚C. The colorimetric performance of the test strips was maintained and neither was colour decay exhibited after 10 months of storage in a shelf. The test strip achieved an eye-ball limit of detection of 1.76 x10-2 mg L-1 and its suitability was demonstrated by the determination of ascorbic acid in fruit juices, urine, serum, and vitamin C tablets. The second colorimetric test strip for ascorbic acid and dopamine employed prussian blue synthesised in-situ in nylon6. Ascorbic acid turned the deep blue test strip to light blue at pH 3, and a faded navy blue colour at a pH range of 6 - 7 while dopamine changed the strip to purple at the same pH range. The versatility of the test strip was demonstrated by detecting ascorbic acid in commercial fruit juices as well as by detecting ascorbic acid as well as dopamine in fortified urine. The eye-ball detection limit of the Prussian blue test strip for ascorbic acid and dopamine was 17.6 mg L-1 and 18.9 mg L-1, respectively. The third method involved a covalent approach, where poly(vinylbenzyl chloride) nanofibers were post functionalised with 2-(2′-pyridyl)-imidazole and iron(III) for the selective detection of ascorbic acid and dopamine. The eye-ball detection limit for ascorbic acid and dopamine was 17.6 mg L-1 and 18.9 mg L-1, respectively. The test strip was selective for dopamine, but the detection of ascorbic acid suffered from interference by glutathione. The application of the test strips was nevertheless demonstrated by the detection of ascorbic acid in fruit juices and dopamine in fortified urine. The developed test strips employing the three approaches were applied without sample pre-treatment and use of supporting equipment.
- Full Text:
- Date Issued: 2014
Electrospun nanofibers as solid phase extraction sorbents and support for alkylphenols colorimetric probes
- Authors: Tancu, Yolanda
- Date: 2014
- Subjects: Nanofibers , Electrospinning , Extraction (Chemistry) , Sorbents , Phenols , Colorimetry , Transmission electron microscopy , High resolution spectroscopy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4486 , http://hdl.handle.net/10962/d1012997
- Description: The thesis reports on fabricating alternative solid phase extraction (SPE) sorbents and colorimetric probes based on electrospun nanofibers for alkylphenols (APs). Hydroxyl methylated styrene [poly(co-styrene-CH₃OH)] and 3-oxobutanoate styrene [poly(co-styrene-OCOCH₃COCH₃)] copolymers were synthesized and fabricated into sorbent materials by electro-spinning/spraying. The fabricated morphologies consisting of bead free fibers, beaded fibers and particles were evaluated as SPE sorbents using batch experiments. Electropun fibers proved to be better sorbents as they exhibited extraction efficiency that exceeded 95% compared to 60% for beaded fibers and 40% for particles. In view to reduce sample and solvent volumes, smooth fibers were packed into pipette tips as SPE devices that yielded quantitative recoveries of APs from spiked wastewater samples. Recoveries ranged from 70% to 125% with LOD of 0.008, 0.01 and 0.1 μg mL⁻¹ for 4-tert octylphenol (4-t-OP), 4-octylphenol (4-OP) and 4-nonylphenol (4-NP) respectively, when using high performance liquid chromatography-fluorescence detector (HPLC-FLD). Furthermore, amino functionalised polydiacetylene polymers (PDAs), citrate capped gold (AuNPs) and silver nanoparticles (AgNPs) were evaluated as colorimetric probes for visual detection of APs. In colloidal studies, AuNPs probe showed a colour change from wine red to green upon introduction of analyte. UV-vis spectroscopy revealed the shifting of the surface plasmon resonance (SPR) peak from 525 nm to 729 nm induced by aggregation of AuNPs. For AgNPs probe, a colour change was observed from yellowish green to brown. Transmission electron microscopy (TEM) studies showed growth of AgNPs. A presumed oxidation of the analyte, forming an absorbing compound at 279 nm in both AgNPs and PDAs probes was also observed. For PDAs probe the colour change was from purple to pink. Concentrations as low as 30 μg mL⁻¹ were detectable in all colloidal based probes. Further colorimetric investigations were conducted with electrospun AuNPs-nylon 6 fiber mat. A colour change from purplish red to navy blue at concentrations of 1000 μg mL⁻¹ was observed. Electrospun AgNPs –nylon 6 fiber mat did not show a distinct colour change. High resolution scanning electron microscopy (HRSEM) revealed the analyte inducing the assembly of AuNPs and AgNPs as they covered the surface of the nanofiber mat. Electrospun nanofibers are a platform for analysis and thus tuning their chemistry will lead to sensitive and selective methods
- Full Text:
- Date Issued: 2014
- Authors: Tancu, Yolanda
- Date: 2014
- Subjects: Nanofibers , Electrospinning , Extraction (Chemistry) , Sorbents , Phenols , Colorimetry , Transmission electron microscopy , High resolution spectroscopy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4486 , http://hdl.handle.net/10962/d1012997
- Description: The thesis reports on fabricating alternative solid phase extraction (SPE) sorbents and colorimetric probes based on electrospun nanofibers for alkylphenols (APs). Hydroxyl methylated styrene [poly(co-styrene-CH₃OH)] and 3-oxobutanoate styrene [poly(co-styrene-OCOCH₃COCH₃)] copolymers were synthesized and fabricated into sorbent materials by electro-spinning/spraying. The fabricated morphologies consisting of bead free fibers, beaded fibers and particles were evaluated as SPE sorbents using batch experiments. Electropun fibers proved to be better sorbents as they exhibited extraction efficiency that exceeded 95% compared to 60% for beaded fibers and 40% for particles. In view to reduce sample and solvent volumes, smooth fibers were packed into pipette tips as SPE devices that yielded quantitative recoveries of APs from spiked wastewater samples. Recoveries ranged from 70% to 125% with LOD of 0.008, 0.01 and 0.1 μg mL⁻¹ for 4-tert octylphenol (4-t-OP), 4-octylphenol (4-OP) and 4-nonylphenol (4-NP) respectively, when using high performance liquid chromatography-fluorescence detector (HPLC-FLD). Furthermore, amino functionalised polydiacetylene polymers (PDAs), citrate capped gold (AuNPs) and silver nanoparticles (AgNPs) were evaluated as colorimetric probes for visual detection of APs. In colloidal studies, AuNPs probe showed a colour change from wine red to green upon introduction of analyte. UV-vis spectroscopy revealed the shifting of the surface plasmon resonance (SPR) peak from 525 nm to 729 nm induced by aggregation of AuNPs. For AgNPs probe, a colour change was observed from yellowish green to brown. Transmission electron microscopy (TEM) studies showed growth of AgNPs. A presumed oxidation of the analyte, forming an absorbing compound at 279 nm in both AgNPs and PDAs probes was also observed. For PDAs probe the colour change was from purple to pink. Concentrations as low as 30 μg mL⁻¹ were detectable in all colloidal based probes. Further colorimetric investigations were conducted with electrospun AuNPs-nylon 6 fiber mat. A colour change from purplish red to navy blue at concentrations of 1000 μg mL⁻¹ was observed. Electrospun AgNPs –nylon 6 fiber mat did not show a distinct colour change. High resolution scanning electron microscopy (HRSEM) revealed the analyte inducing the assembly of AuNPs and AgNPs as they covered the surface of the nanofiber mat. Electrospun nanofibers are a platform for analysis and thus tuning their chemistry will lead to sensitive and selective methods
- Full Text:
- Date Issued: 2014
Empathy in the time of ecological apartheid : a social sculpture practice-led inquiry into developing pedagogies for ecological citizenship
- Authors: McGarry, Dylan Kenneth
- Date: 2014
- Subjects: Education -- Philosophy , Social learning , Environmental education , Arts in education
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1985 , http://hdl.handle.net/10962/d1013154
- Description: Considering the ecological crisis and the increased disconnection between human beings and nature, this study attempts to find the social and aesthetic educational response needed for developing ecological citizenship for the 21st century. In this transdisciplinary study I articulate what at first seems a clumsy attempt to enable the capacities of the embodied ecological citizen, and which later emerges as an alchemical ‘social sculpture’ approach to learning that expands the range of capacities available to the citizen and the citizen’s immediate community. This learning bridges the gap between purely biocentric and technocentric forms of education, and addresses the ambiguity of concepts and forms of action such as ‘sustainability’. My primary focus is enabling both communal and personal forms of agency: new ways of 'doing’ and 'being' in the world as it changes radically. I argue that this demands constantly reflecting on and engaging without understanding, place and perception of the problems we see. Attending to a call for the importance of complex learning processes, that deepens our understanding of sustainability, and the need for methodological and pedagogical approaches to accessible forms of learning socially in the era of climate change and environmental degradation, this study offers a particular insight into the education of an ecological citizen. In particular I examine a form of learning that enables individuals to explore relationships between themselves and their ecologies (both physical and social), and that encourages personal forms of knowing so that each person’s values can be cultivated within the experience and intuitive expression from both inner and outer realities. Central to my research focus is addressing the difficulties inherent in ‘ecological apartheid’, which is defined as a growing separation of relationships that include the human being’s relationship with the natural world, as well as disconnections experienced within one’s own inner and outer capacities. Subsequently I investigate forms of learning that encourage agency that most appropriately enable citizens to respond personally to both inner and outer forms of disconnection. ‘Personal’ and ‘relational agency’ are defined and investigated through an initial twelve-month collaborative participatory contextual profiling exploratory research period in South Africa (phase A), where I explore various forms of multiple-genre creative social learning practice that develop an accessible set of methodologies and pedagogies for the ecological citizen. Through this exploratory research, I place significance in the relatively unknown field of social sculpture, which I investigate through a self-made apprenticeship with Shelley Sacks, an expert in the field. This is documented through a rigorous ethnographic inquiry over a period of 18 months. Following this I undertake another two-year collaborative, practice-based research study across South Africa (phase B: 17 towns, with a total of 350 citizens) and eventually abroad (United Kingdom, Germany, USA and Belgium).The focus of this study was the implementation of a collaboratively developed citizen learning practice entitled Earth Forum developed by Shelley Sacks as a progression from her work “Exchange Values: voices of insivible lives” and my collaboative exploration into Earth Forum and its further development draws heavily from social sculpture methods obtained during the apprenticeship, and applied in 36 different incidences. I further explore the efficacy of this practice in enabling and expanding the capacities of participants, particularly those that encourage the development of personal and relational agency. This was achieved through a pedagogical development and expansion period (phase C). A primary finding through the iterative phase (phase D) was the value of imaginal contemplation, attentive listening, and empathy as capacities that enable an ecological citizen’s overall capability. I ascribed this to Nussbaum and Sen’s (1993) capability theory and the need to enable the articulation and implementation of a citizen’s valued ‘beings and doings’. Through this iterative phase, specific attention is given to listening and intuitive capacities in enabling personal and relational agency, and specifically I observed the fundamental role of imagination in this form of learning. Particularly valuable for the educational contribution of this study is the pedagogical development of the Earth Forum practice that enables an accessible, socially constructed form of learning. This contributes specifically to exploring ‘how’ social learning is undertaken, and I argue that an aesthetic approach to learning is vital for the education of the ecological citizen. I carefully describe how one can conduct collaborative practice-based research that utilises creative connective practice in agency development. This collaborative approach, with regard to learning socially and capacity development for ecological citizenship (that focuses its attention on addressing ecological apartheid and separateness), is articulated through a multiple-genred text. I found that empathetic capacity in ecological citizen education is relatively unexplored, and within listening and as well in empathy theory, that the role of imagination in listening and empathy development, requires greater attention. I attempt to reveal how connective practice considers aesthetic form and shape in expanding capacities of human beings, and introduce novel expanded forms of developing pedagogies that encourage personal and relational agency in the context of ecological apartheid from the artsbased field of social sculpture. Finally, I aim in this study to share the potential value found in social sculpture theory and practice into the field of environmental education and social learning through a reflection on the current context of education and social learning, and its potential enrichment via social sculpture processes.
- Full Text:
- Date Issued: 2014
- Authors: McGarry, Dylan Kenneth
- Date: 2014
- Subjects: Education -- Philosophy , Social learning , Environmental education , Arts in education
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1985 , http://hdl.handle.net/10962/d1013154
- Description: Considering the ecological crisis and the increased disconnection between human beings and nature, this study attempts to find the social and aesthetic educational response needed for developing ecological citizenship for the 21st century. In this transdisciplinary study I articulate what at first seems a clumsy attempt to enable the capacities of the embodied ecological citizen, and which later emerges as an alchemical ‘social sculpture’ approach to learning that expands the range of capacities available to the citizen and the citizen’s immediate community. This learning bridges the gap between purely biocentric and technocentric forms of education, and addresses the ambiguity of concepts and forms of action such as ‘sustainability’. My primary focus is enabling both communal and personal forms of agency: new ways of 'doing’ and 'being' in the world as it changes radically. I argue that this demands constantly reflecting on and engaging without understanding, place and perception of the problems we see. Attending to a call for the importance of complex learning processes, that deepens our understanding of sustainability, and the need for methodological and pedagogical approaches to accessible forms of learning socially in the era of climate change and environmental degradation, this study offers a particular insight into the education of an ecological citizen. In particular I examine a form of learning that enables individuals to explore relationships between themselves and their ecologies (both physical and social), and that encourages personal forms of knowing so that each person’s values can be cultivated within the experience and intuitive expression from both inner and outer realities. Central to my research focus is addressing the difficulties inherent in ‘ecological apartheid’, which is defined as a growing separation of relationships that include the human being’s relationship with the natural world, as well as disconnections experienced within one’s own inner and outer capacities. Subsequently I investigate forms of learning that encourage agency that most appropriately enable citizens to respond personally to both inner and outer forms of disconnection. ‘Personal’ and ‘relational agency’ are defined and investigated through an initial twelve-month collaborative participatory contextual profiling exploratory research period in South Africa (phase A), where I explore various forms of multiple-genre creative social learning practice that develop an accessible set of methodologies and pedagogies for the ecological citizen. Through this exploratory research, I place significance in the relatively unknown field of social sculpture, which I investigate through a self-made apprenticeship with Shelley Sacks, an expert in the field. This is documented through a rigorous ethnographic inquiry over a period of 18 months. Following this I undertake another two-year collaborative, practice-based research study across South Africa (phase B: 17 towns, with a total of 350 citizens) and eventually abroad (United Kingdom, Germany, USA and Belgium).The focus of this study was the implementation of a collaboratively developed citizen learning practice entitled Earth Forum developed by Shelley Sacks as a progression from her work “Exchange Values: voices of insivible lives” and my collaboative exploration into Earth Forum and its further development draws heavily from social sculpture methods obtained during the apprenticeship, and applied in 36 different incidences. I further explore the efficacy of this practice in enabling and expanding the capacities of participants, particularly those that encourage the development of personal and relational agency. This was achieved through a pedagogical development and expansion period (phase C). A primary finding through the iterative phase (phase D) was the value of imaginal contemplation, attentive listening, and empathy as capacities that enable an ecological citizen’s overall capability. I ascribed this to Nussbaum and Sen’s (1993) capability theory and the need to enable the articulation and implementation of a citizen’s valued ‘beings and doings’. Through this iterative phase, specific attention is given to listening and intuitive capacities in enabling personal and relational agency, and specifically I observed the fundamental role of imagination in this form of learning. Particularly valuable for the educational contribution of this study is the pedagogical development of the Earth Forum practice that enables an accessible, socially constructed form of learning. This contributes specifically to exploring ‘how’ social learning is undertaken, and I argue that an aesthetic approach to learning is vital for the education of the ecological citizen. I carefully describe how one can conduct collaborative practice-based research that utilises creative connective practice in agency development. This collaborative approach, with regard to learning socially and capacity development for ecological citizenship (that focuses its attention on addressing ecological apartheid and separateness), is articulated through a multiple-genred text. I found that empathetic capacity in ecological citizen education is relatively unexplored, and within listening and as well in empathy theory, that the role of imagination in listening and empathy development, requires greater attention. I attempt to reveal how connective practice considers aesthetic form and shape in expanding capacities of human beings, and introduce novel expanded forms of developing pedagogies that encourage personal and relational agency in the context of ecological apartheid from the artsbased field of social sculpture. Finally, I aim in this study to share the potential value found in social sculpture theory and practice into the field of environmental education and social learning through a reflection on the current context of education and social learning, and its potential enrichment via social sculpture processes.
- Full Text:
- Date Issued: 2014
Enabling cumulative knowledge-building through teaching: a legitimation code theory analysis of pedagogic practice in law and political science
- Authors: Clarence, Sherran
- Date: 2014
- Subjects: Law -- Study and teaching (Higher) -- South Africa Political science -- Study and teaching (Higher) -- South Africa Education, Higher -- South Africa College teaching -- South Africa Knowledge, Theory of Social realism
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1966 , http://hdl.handle.net/10962/d1011763
- Description: Much current research and practice in teaching and learning in higher education tends to overfocus on social aspects of education; on how rather than what students are learning. Much of this research and practice is influenced by constructivism, which has a relativist stance on knowledge, generally arguing, contra positivism, that knowledge is constructed in socio-historical contexts and largely inseparable from those who construct it and from issues of power. This leads to a confusion of knowledge with knowing, and knowledge is thus obscured as an object of study because it is only seen or understood as knowing or as a subject of learning and teaching. This ‘knowledge-blindness’ (Maton 2013a: 4) is problematic in higher education because knowledge and knowing are two separate parts of educational fields, and while they need to be brought together to provide a whole account of these fields, they also need to be analysed and understood separately to avoid blurring necessary boundaries and to avoid confusing knowledge itself with how it can be known. Being able to see and analyse knowledge as an object with its own properties and powers is crucial for both epistemological access and social inclusion and justice, because knowledge and knowledge practices are at the heart of academic disciplines in universities. Social realism offers an alternative to the dilemma brought about by constructivism’s tendency towards knowledge-blindness. Social realism argues that it is possible to see and analyse both actors within social fields of practice as well as knowledge as something that is produced by these actors but also about more than just these actors and their practices; thus knowledge can be understood as emergent from these practices and fields but not reducible to them (Maton & Moore 2010). Social realism, drawing from Roy Bhaskar’s critical realist philosophy (1975, 2008), is intent on looking at the real structures and mechanisms that lie beneath appearances and practices in order to understand the ways in which these practices are shaped, and change over time. Legitimation Code Theory is a realist conceptual framework that has, as its central aim, the uncovering and analysis of organising principles that shape and change intellectual and education fields of production and reproduction of knowledge. In other words, the conceptual tools Legitimation Code Theory offers can enable an analysis of both knowledge and knowers within relational social fields of practice by enabling the analysis of the ways in which these fields, such as academic disciplines, are organised and how knowledge and knowing are understood in educational practice. This study draws on social realism more broadly and Legitimation Code Theory specifically to develop a relatively novel conceptual and explanatory framework within which to analyse and answer its central question regarding how to enable cumulative knowledge building through pedagogic practice. Using qualitative data from two academic disciplines, Law and Political Science, which was analysed using a set of conceptual and analytical tools drawn from Legitimation Code Theory, this study shows that the more nuanced and layered accounts of pedagogy that have been generated are able to provide valuable insights into what lecturers are doing as they teach in terms of helping students to acquire, use and produce disciplinary and ‘powerful’ knowledge (Young 2008b). Further, the study demonstrates that the organising principles underlying academic disciplines have a profound effect on how the role of the knower and the place or purpose of knowledge is understood in pedagogy and this affects how the pedagogy is designed and enacted. This study has argued that if we can research pedagogy rigorously using tools that allow us to see the real mechanisms and principles influencing and shaping it, and if we can reclaim the role of disciplinary knowledge as a central part of the pedagogic relationship between lecturer and students, then we can begin to see how teaching both enables and constrains cumulative learning. Further, we can change pedagogy to better enable cumulative learning and greater epistemological access to disciplinary knowledge and related practices for greater numbers of students. The study concludes by suggesting that the conceptual tools offered by Legitimation Code Theory can provide academic lecturers with a set of tools that can begin to enable them to 'see' and understand their own teaching more clearly, as well as the possible gaps between what they are teaching and what their students are learning. This study argues that a social realist approach to the study of pedagogy such as the one used here can begin not only to enable changes in pedagogy aimed at filling these gaps but also begin to provide a more rigorous theoretical and practical approach to analysing, understanding and enacting pedagogic practice. This, in turn, can lead to more socially just and inclusive student learning and epistemic and social access to the powerful knowledge and ways of knowing in their disciplines.
- Full Text:
- Date Issued: 2014
- Authors: Clarence, Sherran
- Date: 2014
- Subjects: Law -- Study and teaching (Higher) -- South Africa Political science -- Study and teaching (Higher) -- South Africa Education, Higher -- South Africa College teaching -- South Africa Knowledge, Theory of Social realism
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1966 , http://hdl.handle.net/10962/d1011763
- Description: Much current research and practice in teaching and learning in higher education tends to overfocus on social aspects of education; on how rather than what students are learning. Much of this research and practice is influenced by constructivism, which has a relativist stance on knowledge, generally arguing, contra positivism, that knowledge is constructed in socio-historical contexts and largely inseparable from those who construct it and from issues of power. This leads to a confusion of knowledge with knowing, and knowledge is thus obscured as an object of study because it is only seen or understood as knowing or as a subject of learning and teaching. This ‘knowledge-blindness’ (Maton 2013a: 4) is problematic in higher education because knowledge and knowing are two separate parts of educational fields, and while they need to be brought together to provide a whole account of these fields, they also need to be analysed and understood separately to avoid blurring necessary boundaries and to avoid confusing knowledge itself with how it can be known. Being able to see and analyse knowledge as an object with its own properties and powers is crucial for both epistemological access and social inclusion and justice, because knowledge and knowledge practices are at the heart of academic disciplines in universities. Social realism offers an alternative to the dilemma brought about by constructivism’s tendency towards knowledge-blindness. Social realism argues that it is possible to see and analyse both actors within social fields of practice as well as knowledge as something that is produced by these actors but also about more than just these actors and their practices; thus knowledge can be understood as emergent from these practices and fields but not reducible to them (Maton & Moore 2010). Social realism, drawing from Roy Bhaskar’s critical realist philosophy (1975, 2008), is intent on looking at the real structures and mechanisms that lie beneath appearances and practices in order to understand the ways in which these practices are shaped, and change over time. Legitimation Code Theory is a realist conceptual framework that has, as its central aim, the uncovering and analysis of organising principles that shape and change intellectual and education fields of production and reproduction of knowledge. In other words, the conceptual tools Legitimation Code Theory offers can enable an analysis of both knowledge and knowers within relational social fields of practice by enabling the analysis of the ways in which these fields, such as academic disciplines, are organised and how knowledge and knowing are understood in educational practice. This study draws on social realism more broadly and Legitimation Code Theory specifically to develop a relatively novel conceptual and explanatory framework within which to analyse and answer its central question regarding how to enable cumulative knowledge building through pedagogic practice. Using qualitative data from two academic disciplines, Law and Political Science, which was analysed using a set of conceptual and analytical tools drawn from Legitimation Code Theory, this study shows that the more nuanced and layered accounts of pedagogy that have been generated are able to provide valuable insights into what lecturers are doing as they teach in terms of helping students to acquire, use and produce disciplinary and ‘powerful’ knowledge (Young 2008b). Further, the study demonstrates that the organising principles underlying academic disciplines have a profound effect on how the role of the knower and the place or purpose of knowledge is understood in pedagogy and this affects how the pedagogy is designed and enacted. This study has argued that if we can research pedagogy rigorously using tools that allow us to see the real mechanisms and principles influencing and shaping it, and if we can reclaim the role of disciplinary knowledge as a central part of the pedagogic relationship between lecturer and students, then we can begin to see how teaching both enables and constrains cumulative learning. Further, we can change pedagogy to better enable cumulative learning and greater epistemological access to disciplinary knowledge and related practices for greater numbers of students. The study concludes by suggesting that the conceptual tools offered by Legitimation Code Theory can provide academic lecturers with a set of tools that can begin to enable them to 'see' and understand their own teaching more clearly, as well as the possible gaps between what they are teaching and what their students are learning. This study argues that a social realist approach to the study of pedagogy such as the one used here can begin not only to enable changes in pedagogy aimed at filling these gaps but also begin to provide a more rigorous theoretical and practical approach to analysing, understanding and enacting pedagogic practice. This, in turn, can lead to more socially just and inclusive student learning and epistemic and social access to the powerful knowledge and ways of knowing in their disciplines.
- Full Text:
- Date Issued: 2014
Enhanced visualisation techniques to support access to personal information across multiple devices
- Authors: Beets, Simone Yvonne
- Date: 2014
- Subjects: Information visualisation , Database management , Web services , Personal information management
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10500 , http://hdl.handle.net/10948/d1021136
- Description: The increasing number of devices owned by a single user makes it increasingly difficult to access, organise and visualise personal information (PI), i.e. documents and media, across these devices. The primary method that is currently used to organise and visualise PI is the hierarchical folder structure, which is a familiar and widely used means to manage PI. However, this hierarchy does not effectively support personal information management (PIM) across multiple devices. Current solutions, such as the Personal Information Dashboard and Stuff I’ve Seen, do not support PIM across multiple devices. Alternative PIM tools, such as Dropbox and TeamViewer, attempt to provide a means of accessing PI across multiple devices, but these solutions also suffer from several limitations. The aim of this research was to investigate to what extent enhanced information visualisation (IV) techniques could be used to support accessing PI across multiple devices. An interview study was conducted to identify how PI is currently managed across multiple devices. This interview study further motivated the need for a tool to support visualising PI across multiple devices and identified requirements for such an IV tool. Several suitable IV techniques were selected and enhanced to support PIM across multiple devices. These techniques comprised an Overview using a nested circles layout, a Tag Cloud and a Partition Layout, which used a novel set-based technique. A prototype, called MyPSI, was designed and implemented incorporating these enhanced IV techniques. The requirements and design of the MyPSI prototype were validated using a conceptual walkthrough. The design of the MyPSI prototype was initially implemented for a desktop or laptop device with mouse-based interaction. A sample personal space of information (PSI) was used to evaluate the prototype in a controlled user study. The user study was used to identify any usability problems with the MyPSI prototype. The results were highly positive and the participants agreed that such a tool could be useful in future. No major problems were identified with the prototype. The MyPSI prototype was then implemented on a mobile device, specifically an Android tablet device, using a similar design, but supporting touch-based interaction. Users were allowed to upload their own PSI using Dropbox, which was visualised by the MyPSI prototype. A field study was conducted following the Multi-dimensional In-depth Long-term Case Studies approach specifically designed for IV evaluation. The field study was conducted over a two-week period, evaluating both the desktop and mobile versions of the MyPSI prototype. Both versions received positive results, but the desktop version was slightly preferred over the mobile version, mainly due to familiarity and problems experienced with the mobile implementation. Design recommendations were derived to inform future designs of IV tools to support accessing PI across multiple devices. This research has shown that IV techniques can be enhanced to effectively support accessing PI across multiple devices. Future work will involve customising the MyPSI prototype for mobile phones and supporting additional platforms.
- Full Text:
- Date Issued: 2014
- Authors: Beets, Simone Yvonne
- Date: 2014
- Subjects: Information visualisation , Database management , Web services , Personal information management
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10500 , http://hdl.handle.net/10948/d1021136
- Description: The increasing number of devices owned by a single user makes it increasingly difficult to access, organise and visualise personal information (PI), i.e. documents and media, across these devices. The primary method that is currently used to organise and visualise PI is the hierarchical folder structure, which is a familiar and widely used means to manage PI. However, this hierarchy does not effectively support personal information management (PIM) across multiple devices. Current solutions, such as the Personal Information Dashboard and Stuff I’ve Seen, do not support PIM across multiple devices. Alternative PIM tools, such as Dropbox and TeamViewer, attempt to provide a means of accessing PI across multiple devices, but these solutions also suffer from several limitations. The aim of this research was to investigate to what extent enhanced information visualisation (IV) techniques could be used to support accessing PI across multiple devices. An interview study was conducted to identify how PI is currently managed across multiple devices. This interview study further motivated the need for a tool to support visualising PI across multiple devices and identified requirements for such an IV tool. Several suitable IV techniques were selected and enhanced to support PIM across multiple devices. These techniques comprised an Overview using a nested circles layout, a Tag Cloud and a Partition Layout, which used a novel set-based technique. A prototype, called MyPSI, was designed and implemented incorporating these enhanced IV techniques. The requirements and design of the MyPSI prototype were validated using a conceptual walkthrough. The design of the MyPSI prototype was initially implemented for a desktop or laptop device with mouse-based interaction. A sample personal space of information (PSI) was used to evaluate the prototype in a controlled user study. The user study was used to identify any usability problems with the MyPSI prototype. The results were highly positive and the participants agreed that such a tool could be useful in future. No major problems were identified with the prototype. The MyPSI prototype was then implemented on a mobile device, specifically an Android tablet device, using a similar design, but supporting touch-based interaction. Users were allowed to upload their own PSI using Dropbox, which was visualised by the MyPSI prototype. A field study was conducted following the Multi-dimensional In-depth Long-term Case Studies approach specifically designed for IV evaluation. The field study was conducted over a two-week period, evaluating both the desktop and mobile versions of the MyPSI prototype. Both versions received positive results, but the desktop version was slightly preferred over the mobile version, mainly due to familiarity and problems experienced with the mobile implementation. Design recommendations were derived to inform future designs of IV tools to support accessing PI across multiple devices. This research has shown that IV techniques can be enhanced to effectively support accessing PI across multiple devices. Future work will involve customising the MyPSI prototype for mobile phones and supporting additional platforms.
- Full Text:
- Date Issued: 2014
Enhancing parental involvement in primary schools in disadvantaged communities
- Hendricks, Charlotte Augusta
- Authors: Hendricks, Charlotte Augusta
- Date: 2014
- Subjects: Education, Primary -- Parent participation -- South Africa -- Port Elizabeth , Parent-teacher relationships -- South Africa -- Port Elizabeth , Ecological Systems Theory
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9461 , http://hdl.handle.net/10948/d1020169
- Description: The main research question guiding this study is: “What strategies can be established to enhance parental involvement in primary schools in disadvantaged communities in the Northern Areas of Port Elizabeth”? To answer this question, this study examines parents’ and teachers’ practices concerning parental involvement in the Northern Areas of Nelson Mandela Metropolitan. Parents and teachers were purposely selected from participating schools. In this qualitative study, the researcher proposed strategies to enhance parental involvement at primary schools. Qualitative research methods, associated with phenomenological inquiry were employed to explore the life-world of the participants who have had personal experience with the phenomenon of parental involvement. Data was collected through semi-structured interviews with parents and teachers. This allowed the researcher to gather in-depth information about opinions, beliefs, practices and attitudes concerning the involvement of parents in their children’s education. Bronfenbrenner’s ecosystemic theory served as the theorectical framework of this investigation. Since this study is about parental involvement in primary schools educational policies like inclusive education as well as different models of parental involvement were investigated in the literature study. The results of the study indicated several barriers to the enhancement of parental involvement for instance communication barriers between parents and teachers. The researcher established four strategies for the enhancement of parental involvement and recommended that these strategies should be employed by schools and other stakeholders. She also made further recommendations for parents, teachers, school principals, Department of Basic Education and professionals in the community.
- Full Text:
- Date Issued: 2014
- Authors: Hendricks, Charlotte Augusta
- Date: 2014
- Subjects: Education, Primary -- Parent participation -- South Africa -- Port Elizabeth , Parent-teacher relationships -- South Africa -- Port Elizabeth , Ecological Systems Theory
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9461 , http://hdl.handle.net/10948/d1020169
- Description: The main research question guiding this study is: “What strategies can be established to enhance parental involvement in primary schools in disadvantaged communities in the Northern Areas of Port Elizabeth”? To answer this question, this study examines parents’ and teachers’ practices concerning parental involvement in the Northern Areas of Nelson Mandela Metropolitan. Parents and teachers were purposely selected from participating schools. In this qualitative study, the researcher proposed strategies to enhance parental involvement at primary schools. Qualitative research methods, associated with phenomenological inquiry were employed to explore the life-world of the participants who have had personal experience with the phenomenon of parental involvement. Data was collected through semi-structured interviews with parents and teachers. This allowed the researcher to gather in-depth information about opinions, beliefs, practices and attitudes concerning the involvement of parents in their children’s education. Bronfenbrenner’s ecosystemic theory served as the theorectical framework of this investigation. Since this study is about parental involvement in primary schools educational policies like inclusive education as well as different models of parental involvement were investigated in the literature study. The results of the study indicated several barriers to the enhancement of parental involvement for instance communication barriers between parents and teachers. The researcher established four strategies for the enhancement of parental involvement and recommended that these strategies should be employed by schools and other stakeholders. She also made further recommendations for parents, teachers, school principals, Department of Basic Education and professionals in the community.
- Full Text:
- Date Issued: 2014