The development of a personal philosophy and practice of servant leadership : a grounded theory study
- Authors: Taylor, Simon Michael
- Date: 2014
- Subjects: Hilton College (Pietermaritzburg, South Africa) , Servant leadership , Grounded theory , Community and school -- South Africa -- KwaZulu-Natal , Student volunteers in social service -- South Africa -- KwaZulu-Natal , Educational leadership -- South Africa -- KwaZulu-Natal
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1199 , http://hdl.handle.net/10962/d1012986
- Description: The purpose of this study is to develop a substantive grounded theory explaining the development of a philosophy and the practice of leadership amongst young adults who had attended Hilton College and whom were exposed to their servant leadership development programme. The grounded theory method in this study was developed using conventions identified by Strauss and Corbin (1990) and relying upon a collection of incidents noted during interviews with former students, teachers, housemasters, headmaster and Hiltonian Society board members. In total thirty-six interviews were conducted over a period of four years in South Africa, the United Kingdom and Kenya. Using the grounded theory methodology, an understanding of the theoretical model emerged through the development of a personal philosophy and the practice of servant leadership. Related to the central phenomenon of individual leadership philosophy and practice, the causal condition of opportunity to lead, influenced how the individual philosophy and practice emerged. Strategies used by the participants to nurture their philosophy and practice of leadership were the leadership development programme, community service, feedback and reflection. The data identified the intervening conditions and conditions relating to the context of the leadership philosophy and practice. The consequences of developing a leadership philosophy and practice were related to leadership behaviour; self-esteem; growth; follower relations; empowering of others; and relationship to institutions. The theoretical model illustrated the holistic nature of an individual’s leadership philosophy and practice. In this instance, the nature of the data revealed that the individual's leadership philosophy and practice that developed amongst the participants was predominately servant leadership. The different approaches to leadership development were scrutinised with the intention of locating the grounded theory that developed in this study, within the available literature. The literature did provide some useful insights, in particular the social field theory of Bourdieu (1998), which offered a more encompassing explanation and showed much promise in providing an understanding of leadership development. Wheatley's (1999) interpretation of field theory further explained the influence of servant leadership in leadership development. Finally, the researcher developed a set of propositions and recommendations for practice and future research and discussed the value of this research.
- Full Text:
- Date Issued: 2014
- Authors: Taylor, Simon Michael
- Date: 2014
- Subjects: Hilton College (Pietermaritzburg, South Africa) , Servant leadership , Grounded theory , Community and school -- South Africa -- KwaZulu-Natal , Student volunteers in social service -- South Africa -- KwaZulu-Natal , Educational leadership -- South Africa -- KwaZulu-Natal
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1199 , http://hdl.handle.net/10962/d1012986
- Description: The purpose of this study is to develop a substantive grounded theory explaining the development of a philosophy and the practice of leadership amongst young adults who had attended Hilton College and whom were exposed to their servant leadership development programme. The grounded theory method in this study was developed using conventions identified by Strauss and Corbin (1990) and relying upon a collection of incidents noted during interviews with former students, teachers, housemasters, headmaster and Hiltonian Society board members. In total thirty-six interviews were conducted over a period of four years in South Africa, the United Kingdom and Kenya. Using the grounded theory methodology, an understanding of the theoretical model emerged through the development of a personal philosophy and the practice of servant leadership. Related to the central phenomenon of individual leadership philosophy and practice, the causal condition of opportunity to lead, influenced how the individual philosophy and practice emerged. Strategies used by the participants to nurture their philosophy and practice of leadership were the leadership development programme, community service, feedback and reflection. The data identified the intervening conditions and conditions relating to the context of the leadership philosophy and practice. The consequences of developing a leadership philosophy and practice were related to leadership behaviour; self-esteem; growth; follower relations; empowering of others; and relationship to institutions. The theoretical model illustrated the holistic nature of an individual’s leadership philosophy and practice. In this instance, the nature of the data revealed that the individual's leadership philosophy and practice that developed amongst the participants was predominately servant leadership. The different approaches to leadership development were scrutinised with the intention of locating the grounded theory that developed in this study, within the available literature. The literature did provide some useful insights, in particular the social field theory of Bourdieu (1998), which offered a more encompassing explanation and showed much promise in providing an understanding of leadership development. Wheatley's (1999) interpretation of field theory further explained the influence of servant leadership in leadership development. Finally, the researcher developed a set of propositions and recommendations for practice and future research and discussed the value of this research.
- Full Text:
- Date Issued: 2014
The development of functionalized electrospun nanofibers for the control of pathogenic microorganisms in water.
- Authors: Kleyi, Phumelele Eldridge
- Date: 2014
- Subjects: Electrospinning , Nanofibers , Pathogenic microorganisms , Pathogenic microorganisms -- Detection , Drinking water -- Microbiology , Water quality -- Measurement , Imidazoles , Spectrum analysis , Anti-infective agents , Polymerization
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4497 , http://hdl.handle.net/10962/d1013134
- Description: The thesis presents the development of functionalized electrospun nylon 6 nanofibers for the eradication of pathogenic microorganisms in drinking water. Imidazole derivatives were synthesized as the antimicrobial agents and were characterized by means of NMR spectroscopy, IR spectroscopy, elemental analysis and X-ray crystallography. The first set of compounds (2-substituted N-alkylimidazoles) consisted of imidazole derivatives substituted with different alkyl groups (methyl, ethyl, propyl, butyl, heptyl, octyl, decyl and benzyl) at the 1-position and various functional groups [carboxaldehyde (CHO), alcohol (CH2OH) and carboxylic acid (COOH)] at the 2-position. It was observed that the antimicrobial activity of the compounds increased with increasing alkyl chain length and decreasing pKa of the 2-substituent. It was also observed that the antimicrobial activity was predominantly against a Gram-positive bacterial strains [Staphylococcus aureus (MIC = 5-160 μg/mL) and Bacillus subtilis subsp. spizizenii (MIC = 5-20 μg/mL)], with the latter being the more susceptible. However, the compounds displayed poor antimicrobial activity against Gram-negative bacterial strain, E. coli (MIC = 150- >2500 μg/mL) and did not show any activity against the yeast, C. albicans. The second set of compounds consisted of the silver(I) complexes containing 2-hydroxymethyl-N-alkylimidazoles. The complexes displayed a broad spectrum antimicrobial activity towards the microorganisms that were tested and their activity [E. coli (MIC = 5-40 μg/mL), S. aureus (MIC = 20-80 μg/mL), Bacillus subtilis subsp. spizizenii (MIC = 5-40 μg/mL) and C. albicans (MIC = 40-80 μg/mL)] increased with the alkyl chain length of the 2-hydroxymethyl-N-alkylimidazole. The third set of compounds consisted of the vinylimidazoles containing the vinyl group either at the 1-position or at the 4- or 5- position. The imidazoles with the vinyl group at the 4- or 5-position contained the alkyl group (decyl) at the 1-position. For the fabrication of the antimicrobial nanofibers, the first two sets of imidazole derivatives (2-substituted N-alkylimidazoles and silver(I) complexes) were incorporated into electrospun nylon 6 nanofibers while the third set (2-substituted vinylimidazoles) was immobilized onto electrospun nylon 6 nanofibers employing the graft polymerization method. The antimicrobial nylon nanofibers were characterized by IR spectroscopy and SEM-EDAX (EDS). The electrospun nylon 6 nanofibers incorporated with 2-substituted N-alkylimidazoles displayed moderate to excellent levels of growth reduction against S. aureus (73.2-99.8 percent). For the electrospun nylon 6 nanofibers incorporated with silver(I) complexes, the levels of growth reduction were >99.99 percent, after the antimicrobial activity evaluation using the shake flask method. Furthermore, the grafted electrospun nylon 6 nanofibers showed excellent levels of growth reduction for E. coli (99.94-99.99 percent) and S. aureus (99.93-99.99 percent). The reusability results indicated that the grafted electrospun nylon 6 nanofibers maintained the antibacterial activity until the third cycle of useage. The cytotoxicity studies showed that grafted electrospun nylon 6 nanofibers possess lower cytotoxic effects on Chang liver cells with IC50 values in the range 23.48-26.81 μg/mL. The thesis demonstrated that the development of antimicrobial electrospun nanofibers, with potential for the eradication of pathogenic microoganisms in water, could be accomplished by incorporation as well as immobilization strategies.
- Full Text:
- Date Issued: 2014
- Authors: Kleyi, Phumelele Eldridge
- Date: 2014
- Subjects: Electrospinning , Nanofibers , Pathogenic microorganisms , Pathogenic microorganisms -- Detection , Drinking water -- Microbiology , Water quality -- Measurement , Imidazoles , Spectrum analysis , Anti-infective agents , Polymerization
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4497 , http://hdl.handle.net/10962/d1013134
- Description: The thesis presents the development of functionalized electrospun nylon 6 nanofibers for the eradication of pathogenic microorganisms in drinking water. Imidazole derivatives were synthesized as the antimicrobial agents and were characterized by means of NMR spectroscopy, IR spectroscopy, elemental analysis and X-ray crystallography. The first set of compounds (2-substituted N-alkylimidazoles) consisted of imidazole derivatives substituted with different alkyl groups (methyl, ethyl, propyl, butyl, heptyl, octyl, decyl and benzyl) at the 1-position and various functional groups [carboxaldehyde (CHO), alcohol (CH2OH) and carboxylic acid (COOH)] at the 2-position. It was observed that the antimicrobial activity of the compounds increased with increasing alkyl chain length and decreasing pKa of the 2-substituent. It was also observed that the antimicrobial activity was predominantly against a Gram-positive bacterial strains [Staphylococcus aureus (MIC = 5-160 μg/mL) and Bacillus subtilis subsp. spizizenii (MIC = 5-20 μg/mL)], with the latter being the more susceptible. However, the compounds displayed poor antimicrobial activity against Gram-negative bacterial strain, E. coli (MIC = 150- >2500 μg/mL) and did not show any activity against the yeast, C. albicans. The second set of compounds consisted of the silver(I) complexes containing 2-hydroxymethyl-N-alkylimidazoles. The complexes displayed a broad spectrum antimicrobial activity towards the microorganisms that were tested and their activity [E. coli (MIC = 5-40 μg/mL), S. aureus (MIC = 20-80 μg/mL), Bacillus subtilis subsp. spizizenii (MIC = 5-40 μg/mL) and C. albicans (MIC = 40-80 μg/mL)] increased with the alkyl chain length of the 2-hydroxymethyl-N-alkylimidazole. The third set of compounds consisted of the vinylimidazoles containing the vinyl group either at the 1-position or at the 4- or 5- position. The imidazoles with the vinyl group at the 4- or 5-position contained the alkyl group (decyl) at the 1-position. For the fabrication of the antimicrobial nanofibers, the first two sets of imidazole derivatives (2-substituted N-alkylimidazoles and silver(I) complexes) were incorporated into electrospun nylon 6 nanofibers while the third set (2-substituted vinylimidazoles) was immobilized onto electrospun nylon 6 nanofibers employing the graft polymerization method. The antimicrobial nylon nanofibers were characterized by IR spectroscopy and SEM-EDAX (EDS). The electrospun nylon 6 nanofibers incorporated with 2-substituted N-alkylimidazoles displayed moderate to excellent levels of growth reduction against S. aureus (73.2-99.8 percent). For the electrospun nylon 6 nanofibers incorporated with silver(I) complexes, the levels of growth reduction were >99.99 percent, after the antimicrobial activity evaluation using the shake flask method. Furthermore, the grafted electrospun nylon 6 nanofibers showed excellent levels of growth reduction for E. coli (99.94-99.99 percent) and S. aureus (99.93-99.99 percent). The reusability results indicated that the grafted electrospun nylon 6 nanofibers maintained the antibacterial activity until the third cycle of useage. The cytotoxicity studies showed that grafted electrospun nylon 6 nanofibers possess lower cytotoxic effects on Chang liver cells with IC50 values in the range 23.48-26.81 μg/mL. The thesis demonstrated that the development of antimicrobial electrospun nanofibers, with potential for the eradication of pathogenic microoganisms in water, could be accomplished by incorporation as well as immobilization strategies.
- Full Text:
- Date Issued: 2014
The establishment of a mobile phone information security culture: linking student awareness and behavioural intent
- Authors: Bukelwa, Ngoqo
- Date: 2014
- Subjects: Information security awareness -- Mobile phone security , Information safety
- Language: English
- Type: Thesis , Doctoral , PhD (Information Systems)
- Identifier: http://hdl.handle.net/10353/657 , vital:26485 , Information security awareness -- Mobile phone security , Information safety
- Description: The information security behaviour of technology users has become an increasingly popular research area as security experts have come to recognise that while securing technology by means of firewalls, passwords and offsite backups is important, such security may be rendered ineffective if the technology users themselves are not information security conscious. The mobile phone has become a necessity for many students but, at the same time, it exposes them to security threats that may result in a loss of information. Students in developing countries are at a disadvantage because they have limited access to information relating to information security threats, unlike their counterparts in more developed societies who can readily access this information from sources like the Internet. The developmental environment is plagued with challenges like access to the Internet or limited access to computers. The poor security behaviour exhibited by student mobile phone users, which was confirmed by the findings of this study, is of particular interest in the university context as most undergraduate students are offered a computer-related course which covers certain information security-related principles. During the restructuring of the South African higher education system, smaller universities and technikons (polytechnics) were merged to form comprehensive universities. Thus, the resultant South African university landscape is made up of traditional and comprehensive universities as well as universities of technology. Ordinarily, one would expect university students to have similar profiles. However in the case of this study, the environment was a unique factor which had a direct impact on students’ learning experiences and learning outcomes. Mbeki (2004) refers to two economies within South Africa the first one is financially sound and globally integrated, and the other found in urban and rural areas consists of unemployed and unemployable people who do not benefit from progress in the first economy. Action research was the methodological approach which was chosen for the purposes of this study to collect the requisite data among a population of university students from the ‘second economy’. The study focuses on the relationship between awareness and behavioural intention in understanding mobile phone user information security behaviour. The study concludes by proposing a behaviour profile forecasting framework based on predefined security behavioural profiles. A key finding of this study is that the security behaviour exhibited by mobile phone users is influenced by a combination of information security awareness and information security behavioural intention, and not just information security awareness.
- Full Text:
- Date Issued: 2014
- Authors: Bukelwa, Ngoqo
- Date: 2014
- Subjects: Information security awareness -- Mobile phone security , Information safety
- Language: English
- Type: Thesis , Doctoral , PhD (Information Systems)
- Identifier: http://hdl.handle.net/10353/657 , vital:26485 , Information security awareness -- Mobile phone security , Information safety
- Description: The information security behaviour of technology users has become an increasingly popular research area as security experts have come to recognise that while securing technology by means of firewalls, passwords and offsite backups is important, such security may be rendered ineffective if the technology users themselves are not information security conscious. The mobile phone has become a necessity for many students but, at the same time, it exposes them to security threats that may result in a loss of information. Students in developing countries are at a disadvantage because they have limited access to information relating to information security threats, unlike their counterparts in more developed societies who can readily access this information from sources like the Internet. The developmental environment is plagued with challenges like access to the Internet or limited access to computers. The poor security behaviour exhibited by student mobile phone users, which was confirmed by the findings of this study, is of particular interest in the university context as most undergraduate students are offered a computer-related course which covers certain information security-related principles. During the restructuring of the South African higher education system, smaller universities and technikons (polytechnics) were merged to form comprehensive universities. Thus, the resultant South African university landscape is made up of traditional and comprehensive universities as well as universities of technology. Ordinarily, one would expect university students to have similar profiles. However in the case of this study, the environment was a unique factor which had a direct impact on students’ learning experiences and learning outcomes. Mbeki (2004) refers to two economies within South Africa the first one is financially sound and globally integrated, and the other found in urban and rural areas consists of unemployed and unemployable people who do not benefit from progress in the first economy. Action research was the methodological approach which was chosen for the purposes of this study to collect the requisite data among a population of university students from the ‘second economy’. The study focuses on the relationship between awareness and behavioural intention in understanding mobile phone user information security behaviour. The study concludes by proposing a behaviour profile forecasting framework based on predefined security behavioural profiles. A key finding of this study is that the security behaviour exhibited by mobile phone users is influenced by a combination of information security awareness and information security behavioural intention, and not just information security awareness.
- Full Text:
- Date Issued: 2014
The fantastic subject: a visio-cultural study of Nollywood video-film
- Authors: Makhubu, Nomusa Mary
- Date: 2014
- Subjects: Motion picture industry -- Nigeria , Motion pictures -- Nigeria , Supernatural in motion pictures , Art and popular culture -- Nigeria , Fantasy in motion pictures , Fantasy in art
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2516 , http://hdl.handle.net/10962/d1021166
- Description: The increasing popularity of Nigerian video-film, defined as the ‘Nollywood phenomenon’ (Barrot 2008, Haynes 2010, Adesokan 2011), has attracted recent interdisciplinary academic attention, now known as ‘Nollywood Studies’. The aesthetics and ideological approach of Nollywood video-film are often differentiated from those of the long-established and illustrious African Cinema. Films of Africa are, however, generally characterised by seemingly unique forms of the fantastic – an uneasy theme in scholarship on Nollywood. Although Nollywood video-film is commended by some scholars, its representation of the supernatural and the fantastic is often perceived to be demeaning. Considering the complexity of fantastic themes in creative arts of Africa, this study contributes to this field of study by positioning Nollywood as an interventionist artistic practice that subverts the division between art and popular culture. Further, it considers how this positioning could shift our thinking about what constitutes art and creative practice in Africa. The distinctions between art and popular culture have been inherited from particularly Western disciplines. A critical analysis of the fantastic in Nollywood could expand interpretations of the broader uses of new media and appropriation and develop the discourse on contemporary creative practices of Africa and the parameters of the art history discipline. I interrogate the visual language of the video-film medium through a discussion of other forms of artistic media such as photography, video art, and performance art. The fantastic themes, such as ‘magic’, ‘fetishism’ and violence, conveyed through new media open up a field of questions regarding contemporary social-political dynamics. The cultural value of Nollywood video-film is often based on who makes it. As a proletarian product, Nollywood has been underestimated as a ‘low’ form of culture. Its use of appropriated material connotes the complex dialectics that formulate class difference. I consider how a positioning of video-film as a creative practice could be complicated by the fact that it also operates as a theocentric implement that is used by churches to evangelise. Moreover, I examine how ‘epic’ films construct idyllic notions of ‘ethnicity’ based on dialectics of rational/irrational or real/fantastic. Nollywood video-film also creates images of fantastic spaces. In this thesis, I address concepts of space in Nollywood from which fantastic desire is constructed.
- Full Text:
- Date Issued: 2014
- Authors: Makhubu, Nomusa Mary
- Date: 2014
- Subjects: Motion picture industry -- Nigeria , Motion pictures -- Nigeria , Supernatural in motion pictures , Art and popular culture -- Nigeria , Fantasy in motion pictures , Fantasy in art
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2516 , http://hdl.handle.net/10962/d1021166
- Description: The increasing popularity of Nigerian video-film, defined as the ‘Nollywood phenomenon’ (Barrot 2008, Haynes 2010, Adesokan 2011), has attracted recent interdisciplinary academic attention, now known as ‘Nollywood Studies’. The aesthetics and ideological approach of Nollywood video-film are often differentiated from those of the long-established and illustrious African Cinema. Films of Africa are, however, generally characterised by seemingly unique forms of the fantastic – an uneasy theme in scholarship on Nollywood. Although Nollywood video-film is commended by some scholars, its representation of the supernatural and the fantastic is often perceived to be demeaning. Considering the complexity of fantastic themes in creative arts of Africa, this study contributes to this field of study by positioning Nollywood as an interventionist artistic practice that subverts the division between art and popular culture. Further, it considers how this positioning could shift our thinking about what constitutes art and creative practice in Africa. The distinctions between art and popular culture have been inherited from particularly Western disciplines. A critical analysis of the fantastic in Nollywood could expand interpretations of the broader uses of new media and appropriation and develop the discourse on contemporary creative practices of Africa and the parameters of the art history discipline. I interrogate the visual language of the video-film medium through a discussion of other forms of artistic media such as photography, video art, and performance art. The fantastic themes, such as ‘magic’, ‘fetishism’ and violence, conveyed through new media open up a field of questions regarding contemporary social-political dynamics. The cultural value of Nollywood video-film is often based on who makes it. As a proletarian product, Nollywood has been underestimated as a ‘low’ form of culture. Its use of appropriated material connotes the complex dialectics that formulate class difference. I consider how a positioning of video-film as a creative practice could be complicated by the fact that it also operates as a theocentric implement that is used by churches to evangelise. Moreover, I examine how ‘epic’ films construct idyllic notions of ‘ethnicity’ based on dialectics of rational/irrational or real/fantastic. Nollywood video-film also creates images of fantastic spaces. In this thesis, I address concepts of space in Nollywood from which fantastic desire is constructed.
- Full Text:
- Date Issued: 2014
The impact of economic freedom on economic growth in the SADC
- Authors: Gorlach, Vsevolod Igorevich
- Date: 2014
- Subjects: Free enterprise -- Africa, Southern , Economic development -- Africa, Southern , Africa, Southern -- Economic conditions
- Language: English
- Type: Thesis , Doctoral , DCom
- Identifier: vital:9030 , http://hdl.handle.net/10948/d1020786
- Description: The role of institutions – economic freedom – is a critical determinant of economic growth, yet the global distribution of economic freedom is skewed. Economic freedom focuses on personal choice, the ability to make voluntary transactions, the freedom to compete and the security of property rights. The SADC is attempting to alleviate poverty and achieve sustainable development and economic growth. This thesis illustrates that economic freedom, in aggregate, and on an individual component basis, drives economic growth. The annual data for the 12 SADC counties from 2000 to 2009 are used to construct a panel data model to conduct the empirical analyses. Cross-sectional effects, as well as time (period) effects, are valid; and thus, a two-way error-component model is estimated. The Hausman test showed the regressors to be endogenous and correlated with the error term. The Pesaran CD test, suitable for dynamic panels, determined that cross-sections are interdependent; and the cross-correlation coefficient indicated a relatively weak, yet substantial, correlation. The LSDV two-way error-component model is re-estimated using the Driscoll and Kraay standard errors and time-demeaned data to correct for cross-sectional dependence. Given the endogeneity between the idiosyncratic disturbance term and the regressors, the presence of heteroskedasticity and serial correlation, as well as the interdependence amongst the cross-sections, the econometric model is then estimated using the two-step system general method of moments with forward orthogonal deviations – instead of differencing. The results meet all the post-estimation diagnostic requirements: the Arellano and Bond test for second-order serial correlation fails to reject the null hypothesis of no autocorrelation; theSargan test for over-identification fails to reject the null hypothesis that the over-identification restrictions are valid, and the difference-in-Hansen test fails to reject the null hypothesis that the instrument subsets are strictly exogenous. The empirical results confirm the a priori expectations. Economic freedom is a positive and significant driver of economic growth. Investment and economic openness are positively related to growth, whereas government debt decreases growth. Government consumption is an insignificant driver of a country’s growth. The Granger causality test confirmed the direction of causality; economic freedom precedes economic growth; and it is possible for the SADC to improve their growth rates by becoming economically freer. The coefficient of adjustment derived from the error-correction model indicates that the dynamic system takes approximately two years to adjust to the long-run structural level. The Koyck Transformation indicates that the relationship between economic freedom and growth is intertemporal, requiring a lag structure. An impulse-response function shows that a permanent, positive ‘shock’ to economic freedom results in an increase in economic growth, although the extent differs for each country, as well as for the different freedom components. The five individual economic freedom components are all highly significant and positive drivers of growth; however, the magnitude of the elasticity parameters varies. The causality amongst the components indicates that bidirectional causality is present. Therefore, improving economic freedom in one area improves economic freedom in another, creating a multiplier effect.
- Full Text:
- Date Issued: 2014
- Authors: Gorlach, Vsevolod Igorevich
- Date: 2014
- Subjects: Free enterprise -- Africa, Southern , Economic development -- Africa, Southern , Africa, Southern -- Economic conditions
- Language: English
- Type: Thesis , Doctoral , DCom
- Identifier: vital:9030 , http://hdl.handle.net/10948/d1020786
- Description: The role of institutions – economic freedom – is a critical determinant of economic growth, yet the global distribution of economic freedom is skewed. Economic freedom focuses on personal choice, the ability to make voluntary transactions, the freedom to compete and the security of property rights. The SADC is attempting to alleviate poverty and achieve sustainable development and economic growth. This thesis illustrates that economic freedom, in aggregate, and on an individual component basis, drives economic growth. The annual data for the 12 SADC counties from 2000 to 2009 are used to construct a panel data model to conduct the empirical analyses. Cross-sectional effects, as well as time (period) effects, are valid; and thus, a two-way error-component model is estimated. The Hausman test showed the regressors to be endogenous and correlated with the error term. The Pesaran CD test, suitable for dynamic panels, determined that cross-sections are interdependent; and the cross-correlation coefficient indicated a relatively weak, yet substantial, correlation. The LSDV two-way error-component model is re-estimated using the Driscoll and Kraay standard errors and time-demeaned data to correct for cross-sectional dependence. Given the endogeneity between the idiosyncratic disturbance term and the regressors, the presence of heteroskedasticity and serial correlation, as well as the interdependence amongst the cross-sections, the econometric model is then estimated using the two-step system general method of moments with forward orthogonal deviations – instead of differencing. The results meet all the post-estimation diagnostic requirements: the Arellano and Bond test for second-order serial correlation fails to reject the null hypothesis of no autocorrelation; theSargan test for over-identification fails to reject the null hypothesis that the over-identification restrictions are valid, and the difference-in-Hansen test fails to reject the null hypothesis that the instrument subsets are strictly exogenous. The empirical results confirm the a priori expectations. Economic freedom is a positive and significant driver of economic growth. Investment and economic openness are positively related to growth, whereas government debt decreases growth. Government consumption is an insignificant driver of a country’s growth. The Granger causality test confirmed the direction of causality; economic freedom precedes economic growth; and it is possible for the SADC to improve their growth rates by becoming economically freer. The coefficient of adjustment derived from the error-correction model indicates that the dynamic system takes approximately two years to adjust to the long-run structural level. The Koyck Transformation indicates that the relationship between economic freedom and growth is intertemporal, requiring a lag structure. An impulse-response function shows that a permanent, positive ‘shock’ to economic freedom results in an increase in economic growth, although the extent differs for each country, as well as for the different freedom components. The five individual economic freedom components are all highly significant and positive drivers of growth; however, the magnitude of the elasticity parameters varies. The causality amongst the components indicates that bidirectional causality is present. Therefore, improving economic freedom in one area improves economic freedom in another, creating a multiplier effect.
- Full Text:
- Date Issued: 2014
The impact of export diversification on economic performance in South Africa: 1980-2012
- Authors: Choga, Ireen
- Date: 2014
- Language: English
- Type: Thesis , Doctoral , Doctor of Commerce (in Economics)
- Identifier: vital:11489 , http://hdl.handle.net/10353/d1018223
- Description: A widely held view is that export diversification constitutes an important component of export led growth, and poses a major challenge for many developing countries. Given this, the role of export diversification on economic growth warrants a fresh analysis in South Africa. The primary objective of this study is to determine the impact of export diversification on economic growth in South Africa. In this context, the study seeks to establish the relationship between export diversification, export stability and export growth. Initially, the study examines the extent and structure of export diversification in South Africa; it then empirically establishes the link between export diversification, export stability and export growth. Finally, it develops a model and investigates the effects of export diversification on economic growth in South Africa. As an attempt to fulfill the proposed objectives, this study uses quarterly data for the period 1980 to 2012 as well as data for 28 selected groups of commodities to investigate the effects of export diversification on economic growth in South Africa. Measures of export diversification and structural changes in exports in the context of South Africa were discussed. The findings of this study are that the Commodity Specific Cumulative Experience function showed that plots for manufactured commodities are shifted to the right indicating that the commodities are non-traditional in nature whereas, plots for primary commodities are shifted to the left. Results also indicated that South Africa relies more on traditional exports than manufactured exports. Various measures of export instability were used to calculate the export instability index in South Africa. The results of the study reveal that the South African export basket is slightly diversified, and the less diversified or primary commodities are associated with high instability VECM approach was used to allow us to establish the extent of influence of export diversification and other explanatory variables on economic growth. Consistent with other researchers, the study found that export diversification plays significant roles to economic growth in South Africa. A number of diagnostic checks were employed to validate the parameter evaluation of the outcomes achieved by the model. The model passed all the diagnostic checks. On the whole, the results to a larger extent painted a pictured that export diversification is important or drives economic growth in South Africa. Corroborating our findings with work of other scholars, we conclude that our results are complementary.
- Full Text:
- Date Issued: 2014
- Authors: Choga, Ireen
- Date: 2014
- Language: English
- Type: Thesis , Doctoral , Doctor of Commerce (in Economics)
- Identifier: vital:11489 , http://hdl.handle.net/10353/d1018223
- Description: A widely held view is that export diversification constitutes an important component of export led growth, and poses a major challenge for many developing countries. Given this, the role of export diversification on economic growth warrants a fresh analysis in South Africa. The primary objective of this study is to determine the impact of export diversification on economic growth in South Africa. In this context, the study seeks to establish the relationship between export diversification, export stability and export growth. Initially, the study examines the extent and structure of export diversification in South Africa; it then empirically establishes the link between export diversification, export stability and export growth. Finally, it develops a model and investigates the effects of export diversification on economic growth in South Africa. As an attempt to fulfill the proposed objectives, this study uses quarterly data for the period 1980 to 2012 as well as data for 28 selected groups of commodities to investigate the effects of export diversification on economic growth in South Africa. Measures of export diversification and structural changes in exports in the context of South Africa were discussed. The findings of this study are that the Commodity Specific Cumulative Experience function showed that plots for manufactured commodities are shifted to the right indicating that the commodities are non-traditional in nature whereas, plots for primary commodities are shifted to the left. Results also indicated that South Africa relies more on traditional exports than manufactured exports. Various measures of export instability were used to calculate the export instability index in South Africa. The results of the study reveal that the South African export basket is slightly diversified, and the less diversified or primary commodities are associated with high instability VECM approach was used to allow us to establish the extent of influence of export diversification and other explanatory variables on economic growth. Consistent with other researchers, the study found that export diversification plays significant roles to economic growth in South Africa. A number of diagnostic checks were employed to validate the parameter evaluation of the outcomes achieved by the model. The model passed all the diagnostic checks. On the whole, the results to a larger extent painted a pictured that export diversification is important or drives economic growth in South Africa. Corroborating our findings with work of other scholars, we conclude that our results are complementary.
- Full Text:
- Date Issued: 2014
The implementation of inclusion policy for learners with special education needs in primary schools in Fort beafort district :Towards a rights based approach to education
- Authors: Adewumi, Toyin Mary
- Date: 2014
- Subjects: Inclusive education Education and state -- South Africa -- Eastern Cape Children with disabilities -- Education -- South Africa -- Eastern Cape Special education -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , Degree
- Identifier: http://hdl.handle.net/10353/5873 , vital:29413
- Description: The implementation of inclusion policy for learners with special education needs as stipulated in the Education White Paper 2001has been an issue of concern for South African schools. This study sheds light on the implementation of inclusion policy for learners with special education needs in the selected primary schools in the Fort Beaufort District in the Eastern Cape Province in South Africa. The aim of the study is to examine the implementation of inclusion policy for learners with special education needs. The study was placed within the post-positivism paradigm and used a mixed method research approach that integrated concurrent procedures in the collection, analysis and interpretation of the data. Questionnaires were used to collect quantitative data while qualitative data were collected through interviews, and document analysis. A total number of 30 teachers completed the questionnaires. The researcher conducted interviews with ten principals and eight teachers. She also held interviews with four education district officials and one provincial official. Data were analysed by statistical and non-statistical procedures. The study revealed that the inclusion policy is being implemented in the selected schools. However, there are challenges that are being encountered. Firstly, some teachers have not received adequate training with regards to inclusive education policy. Staff development workshops put in place to address this challenge are minimal, and there is not enough joint effort being established by the different stakeholders with regards to support and monitoring the implementation process. Despite the challenges that accompany implementation of inclusion of learners with special education needs, as well as the difficult working conditions, this study reveals that there are pockets of good practice of inclusion policy in some of the selected schools in the Fort Beaufort District. For instance, it was found that teachers implement inclusion of learners with special education needs, even though the majority of them do not have qualifications in special education. It was also revealed that teachers used learner-centred teaching methods to accommodate all learners, which include group and individual teaching, group demonstration, discussions, question-and-answer sessions, and practical activities.
- Full Text:
- Date Issued: 2014
- Authors: Adewumi, Toyin Mary
- Date: 2014
- Subjects: Inclusive education Education and state -- South Africa -- Eastern Cape Children with disabilities -- Education -- South Africa -- Eastern Cape Special education -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , Degree
- Identifier: http://hdl.handle.net/10353/5873 , vital:29413
- Description: The implementation of inclusion policy for learners with special education needs as stipulated in the Education White Paper 2001has been an issue of concern for South African schools. This study sheds light on the implementation of inclusion policy for learners with special education needs in the selected primary schools in the Fort Beaufort District in the Eastern Cape Province in South Africa. The aim of the study is to examine the implementation of inclusion policy for learners with special education needs. The study was placed within the post-positivism paradigm and used a mixed method research approach that integrated concurrent procedures in the collection, analysis and interpretation of the data. Questionnaires were used to collect quantitative data while qualitative data were collected through interviews, and document analysis. A total number of 30 teachers completed the questionnaires. The researcher conducted interviews with ten principals and eight teachers. She also held interviews with four education district officials and one provincial official. Data were analysed by statistical and non-statistical procedures. The study revealed that the inclusion policy is being implemented in the selected schools. However, there are challenges that are being encountered. Firstly, some teachers have not received adequate training with regards to inclusive education policy. Staff development workshops put in place to address this challenge are minimal, and there is not enough joint effort being established by the different stakeholders with regards to support and monitoring the implementation process. Despite the challenges that accompany implementation of inclusion of learners with special education needs, as well as the difficult working conditions, this study reveals that there are pockets of good practice of inclusion policy in some of the selected schools in the Fort Beaufort District. For instance, it was found that teachers implement inclusion of learners with special education needs, even though the majority of them do not have qualifications in special education. It was also revealed that teachers used learner-centred teaching methods to accommodate all learners, which include group and individual teaching, group demonstration, discussions, question-and-answer sessions, and practical activities.
- Full Text:
- Date Issued: 2014
The influence of indigenous languages on Ugandan English as used in the media
- Authors: Tukwasibwe, Constance
- Date: 2014
- Subjects: Mass media and language -- Uganda , Languages in contact -- Uganda , English language -- Uganda , Language transfer (Language learning) -- Uganda , Communication and culture -- Uganda , Bilingualism -- Uganda , Linguistic demography -- Uganda , Uganda -- Languages
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3646 , http://hdl.handle.net/10962/d1015637
- Description: When two or more languages come in contact, they influence each other in various ways, for example through word borrowing, transfer of sounds, morphology and syntax taken from one language system and imported to another. In this study, the primary concern is on the indigenous communities of Uganda learning the English language, plus the influence that this interaction brings into the linguistic space. Bringing the Ugandan multilingual situation into perspective, the study looks at how the English language has interacted with the local languages and the local speech habits, customs and traditions of the indigenous people, to the extent that it has been indigenized. Some word usage results in miscommunication due to the socio-cultural uniqueness of Ugandan cultural expressions. As an example, because of the practice of polygamy in most Ugandan cultures, words like co-wife are coined to mean 'a woman who shares a husband, or a husband's other wife', a word that is absent in both the language and culture of native English speakers. Furthermore some words are formed by calquing some indigenous language expressions, e.g. 'to eat money' or 'to eat cash', an expression that is calqued from the Luganda phrase, kulya sente. Such word coinages are meant to fill the 'shortfall' where the English language fails to provide adequate equivalents. Understanding the context of this kind of English usage and the influence from the indigenous languages is helpful in handling inter-cultural discourses, as the same expression may convey different senses to different people in different contexts. So then, this study deals with some peculiarities of Ugandan English, namely; the features of Ugandan English grammar which are influenced by the indigenous languages. Evidence from the Corpus of Ugandan English is explored to establish that indigenous languages in Uganda have a significant influence on the English language variety spoken in the country, and that a large part of English bilingual speakers cannot speak English without transferring the features from their mother tongue or indeed, switching and mixing codes. A British corpus was used for the purposes of comparison with Ugandan English. The research was conducted in Uganda, drawing data from English newspapers, radio and television talk -shows that were recorded to provide a structural analysis of the contact situations. The result of the study points to the fact that, indeed, the phonological, morpho-syntactic and semantic characteristics of Ugandan English have a considerable amount of influence from indigenous local languages. This study is hinged on the assumption that when indigenous languages and the target language come together in a linguistic contact situation, the resulting variety would exhibit distinct phonological, lexical, grammatical and semantic/pragmatic features ( cf. Sankoff, 2001; Thomason, 1995; Thomason & Kaufman, 1988; Winford, 2005). However, some of these innovations have attracted criticism from 'prescriptivists' such as Quirk (1985, 1988, 1990); Gaudio (2011); and Abbot (1991) who perceive them as 'nonstandard', 'incorrect English language usage' and a 'direct translation from the language user's mother tongue into English'. Yet, indigenous languages continue to play important roles in shaping the kind of English language usage in Uganda.
- Full Text:
- Date Issued: 2014
- Authors: Tukwasibwe, Constance
- Date: 2014
- Subjects: Mass media and language -- Uganda , Languages in contact -- Uganda , English language -- Uganda , Language transfer (Language learning) -- Uganda , Communication and culture -- Uganda , Bilingualism -- Uganda , Linguistic demography -- Uganda , Uganda -- Languages
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3646 , http://hdl.handle.net/10962/d1015637
- Description: When two or more languages come in contact, they influence each other in various ways, for example through word borrowing, transfer of sounds, morphology and syntax taken from one language system and imported to another. In this study, the primary concern is on the indigenous communities of Uganda learning the English language, plus the influence that this interaction brings into the linguistic space. Bringing the Ugandan multilingual situation into perspective, the study looks at how the English language has interacted with the local languages and the local speech habits, customs and traditions of the indigenous people, to the extent that it has been indigenized. Some word usage results in miscommunication due to the socio-cultural uniqueness of Ugandan cultural expressions. As an example, because of the practice of polygamy in most Ugandan cultures, words like co-wife are coined to mean 'a woman who shares a husband, or a husband's other wife', a word that is absent in both the language and culture of native English speakers. Furthermore some words are formed by calquing some indigenous language expressions, e.g. 'to eat money' or 'to eat cash', an expression that is calqued from the Luganda phrase, kulya sente. Such word coinages are meant to fill the 'shortfall' where the English language fails to provide adequate equivalents. Understanding the context of this kind of English usage and the influence from the indigenous languages is helpful in handling inter-cultural discourses, as the same expression may convey different senses to different people in different contexts. So then, this study deals with some peculiarities of Ugandan English, namely; the features of Ugandan English grammar which are influenced by the indigenous languages. Evidence from the Corpus of Ugandan English is explored to establish that indigenous languages in Uganda have a significant influence on the English language variety spoken in the country, and that a large part of English bilingual speakers cannot speak English without transferring the features from their mother tongue or indeed, switching and mixing codes. A British corpus was used for the purposes of comparison with Ugandan English. The research was conducted in Uganda, drawing data from English newspapers, radio and television talk -shows that were recorded to provide a structural analysis of the contact situations. The result of the study points to the fact that, indeed, the phonological, morpho-syntactic and semantic characteristics of Ugandan English have a considerable amount of influence from indigenous local languages. This study is hinged on the assumption that when indigenous languages and the target language come together in a linguistic contact situation, the resulting variety would exhibit distinct phonological, lexical, grammatical and semantic/pragmatic features ( cf. Sankoff, 2001; Thomason, 1995; Thomason & Kaufman, 1988; Winford, 2005). However, some of these innovations have attracted criticism from 'prescriptivists' such as Quirk (1985, 1988, 1990); Gaudio (2011); and Abbot (1991) who perceive them as 'nonstandard', 'incorrect English language usage' and a 'direct translation from the language user's mother tongue into English'. Yet, indigenous languages continue to play important roles in shaping the kind of English language usage in Uganda.
- Full Text:
- Date Issued: 2014
The plasmodium falciparum exported Hsp40 co-chaperone, PFA0660w
- Authors: Daniyan, Michael Oluwatoyin
- Date: 2014
- Subjects: Molecular chaperones Heat shock proteins Proteins -- Analysis Proteins -- Structure Plasmodium Plasmodium falciparum Malaria -- Prevention -- Research
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4108 , http://hdl.handle.net/10962/d1011780
- Description: Plasmodium falciparum is the pathogen that is responsible for the most virulent, severe and dangerous form of human malaria infection, accounting for nearly a million deaths every year. To survive and develop in the unusual environment of the red blood cells, the parasite causes structural remodelling of the host cell and biochemical changes through the export of virulence factors. Among the exportome are the molecular chaperones of the heat shock protein family, of which Hsp40s and Hsp70s are prominent. PF A0660w, a type II P. falciparum Hsp40, has been shown to be exported in complex with PfHsp70-x into the infected erythrocyte, suggesting possible functional interactions. However, the chaperone properties of PF A0660w and its interactions with proteins of parasite and human origin are yet to be investigated. Using a codon optimised coding region, PF A0660w was successfully expressed in E. coli M 15 [pREP4] cells. However, the expressed protein was largely deposited as insoluble pellet, and analysis of the pellets revealed a high percentage of PF A0660w, characteristic of inclusion body formation. PF A0660w was purified from inclusion bodies using additive enhanced solubilisation and refolding buffers followed by nickel affinity chromatography. SDS-PAGE and western analysis revealed that the purified protein was of high purity. Size exclusion chromatography showed that the protein existed as a monomer in solution and the secondary structure analysis using Fourier transformed infrared spectroscopy (FTIR) confirmed the success of the refolding approach. Its monomeric state suggests that PF A0660w may be functionally different from other Hsp40 that form dimers and that for PF A0660w, dimer formation may not be needed to maintain the stability of the protein in solution, but may occur in response to functional necessities during its interaction with partner Hsp70. PFA0660w was able to significantly stimulate the ATPase activity ofPfl-Isp70-x but not Pfl-Isp70-1 or human Hsp70 (HsHsp70), suggesting a specific functional interaction. Also, PF A0660w produced a dose dependent suppression of rhodanese aggregation and cooperated with Pfl-Isp70-1, PfHsp70-x and HsHsp70 to cause enhanced aggregation suppression. Its ability to independently suppress aggregation may help to maintain substrates in an unfolded conformation for eventual transfer to partner Hsp70s during refolding processes. Also, the in vivo characterisation using a PF A0660w peptide specific antibody confirmed that PF A0660w was exported into the cytosol of infected erythrocytes. Its lack of induction upon heat shock suggests that PF A0660w may not be involved in the response of the parasite to heat stress. Overall, this study has provided the first heterologous over-expression, purification and biochemical evidence for the possible functional role of PF A0660w, and has thereby provided the needed background for further exploration of this protein as a potential target for drug discovery.
- Full Text:
- Date Issued: 2014
- Authors: Daniyan, Michael Oluwatoyin
- Date: 2014
- Subjects: Molecular chaperones Heat shock proteins Proteins -- Analysis Proteins -- Structure Plasmodium Plasmodium falciparum Malaria -- Prevention -- Research
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4108 , http://hdl.handle.net/10962/d1011780
- Description: Plasmodium falciparum is the pathogen that is responsible for the most virulent, severe and dangerous form of human malaria infection, accounting for nearly a million deaths every year. To survive and develop in the unusual environment of the red blood cells, the parasite causes structural remodelling of the host cell and biochemical changes through the export of virulence factors. Among the exportome are the molecular chaperones of the heat shock protein family, of which Hsp40s and Hsp70s are prominent. PF A0660w, a type II P. falciparum Hsp40, has been shown to be exported in complex with PfHsp70-x into the infected erythrocyte, suggesting possible functional interactions. However, the chaperone properties of PF A0660w and its interactions with proteins of parasite and human origin are yet to be investigated. Using a codon optimised coding region, PF A0660w was successfully expressed in E. coli M 15 [pREP4] cells. However, the expressed protein was largely deposited as insoluble pellet, and analysis of the pellets revealed a high percentage of PF A0660w, characteristic of inclusion body formation. PF A0660w was purified from inclusion bodies using additive enhanced solubilisation and refolding buffers followed by nickel affinity chromatography. SDS-PAGE and western analysis revealed that the purified protein was of high purity. Size exclusion chromatography showed that the protein existed as a monomer in solution and the secondary structure analysis using Fourier transformed infrared spectroscopy (FTIR) confirmed the success of the refolding approach. Its monomeric state suggests that PF A0660w may be functionally different from other Hsp40 that form dimers and that for PF A0660w, dimer formation may not be needed to maintain the stability of the protein in solution, but may occur in response to functional necessities during its interaction with partner Hsp70. PFA0660w was able to significantly stimulate the ATPase activity ofPfl-Isp70-x but not Pfl-Isp70-1 or human Hsp70 (HsHsp70), suggesting a specific functional interaction. Also, PF A0660w produced a dose dependent suppression of rhodanese aggregation and cooperated with Pfl-Isp70-1, PfHsp70-x and HsHsp70 to cause enhanced aggregation suppression. Its ability to independently suppress aggregation may help to maintain substrates in an unfolded conformation for eventual transfer to partner Hsp70s during refolding processes. Also, the in vivo characterisation using a PF A0660w peptide specific antibody confirmed that PF A0660w was exported into the cytosol of infected erythrocytes. Its lack of induction upon heat shock suggests that PF A0660w may not be involved in the response of the parasite to heat stress. Overall, this study has provided the first heterologous over-expression, purification and biochemical evidence for the possible functional role of PF A0660w, and has thereby provided the needed background for further exploration of this protein as a potential target for drug discovery.
- Full Text:
- Date Issued: 2014
The role of the deep spawning grounds in chokka squid (Loligo reynaudi d'orbigny, 1845) recruitment
- Authors: Downey, Nicola Jean
- Date: 2014
- Subjects: Squids -- Spawning -- South Africa Squids -- Effect of temperature on -- South Africa Squids -- Embryos -- South Africa Squids -- South Africa -- Geographical distribution Loligo -- Research -- South Africa Loligo fisheries -- South Africa Recruitment (Population biology) -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5359 , http://hdl.handle.net/10962/d1011867
- Description: It was previously thought that the South African chokka squid Loligo reynaudi is exclusively an inshore, shallow water spawner. Although spawning mostly within shallow bays (<60 m) the presence of squid eggs in trawls at depths up to 130 m indicates this species frequently makes use of deeper spawning areas on the mid-shelf. The extent of mid-shelf spawning (referred to as deep spawning) and the contribution to recruitment has yet to be assessed. Studies have shown mid-shelf bottom temperature to vary considerably from those inshore, suggesting chokka squid spawn in two very different oceanographic environments. Considering these apparent environmental differences, what leads to the mid-shelf environment becoming a suitable spawning habitat? Does a suitable benthic habitat, required for the attachment of egg pods, occur on the mid-shelf? These questions are not only important for determining the extent of deep spawning, but also to the understanding of factors “driving” deep spawning. The fate of deep spawned hatchlings is another unknown. It has been proposed that the main chokka squid inshore spawning grounds are positioned to exploit the net westward currents on the Eastern Agulhas Bank, i.e. paralarvae would be transported west from the hatching site to the cold ridge, an area of high primary and secondary productivity on the Central Agulhas Bank. This concept has come to be known as the Western Transport Hypothesis. Lagrangian ROMS-IBMs (regional ocean model system – individual-based model) predict the net westward transport of paralarvae from both the inshore and deep spawning grounds, to the cold ridge. These simulations were used to investigate the transport of hatchlings to the cold ridge feeding grounds before the exhaustion of yolk reserves. The fate of paralarvae on reaching the feeding grounds has not yet been investigated. This work has contributed new knowledge to our understanding of deep spawning and its role in recruitment. Specific aims of this study were to (1) determine the extent, range and importance of the deep spawning grounds relative to those inshore; (2) investigate the deep spawning ground habitat (Agulhas Bank mid-shelf) morphology and oceanographic environment; (3) determine the transport and survival of deep spawned hatchlings; and (4) investigate the origin and distribution of chokka squid paralarvae on the Agulhas Bank. The extent, depth range and importance of the deep spawning grounds, relative to those inshore was assessed using 23 years of demersal trawl survey data. Data for both the west and south coasts of South Africa were examined for egg capsules. No spawning was found on the west coast. Data showed that chokka squid preferred the Eastern Agulhas Bank for spawning. Spawning occurred not only inshore but also on the mid-shelf extending to depths of 270 m near the shelf edge. The majority of deep spawned eggs however, were found in the depth range 71-130 m. Squid egg density markedly decreased beyond 70 m, suggesting delineation between the inshore and deep spawning grounds. Total egg biomass calculations for depths shallower and deeper than 70 m indicated the coastal area to be strongly favoured, i.e. 82 vs. 18%. These results contest the commonly accepted notion that chokka squid is an inshore spawner and redefine the spawning grounds to extend across the shelf. Apart from an initial study investigating bottom temperature on the mid-shelf, very little is known about the deep spawning habitat. St Francis Bay, a commonly used spawning location, was chosen as a demonstration area for further study. The deep spawning grounds (71-130 m) were mapped and benthic habitat described from underwater video footage. A study investigating cross-shelf bottom conditions was undertaken off Thys Bay. CTD data were used to compare seasonal bottom temperature and oxygen on the St Francis Bay inshore and deep spawning grounds. Squid movement between the two spawning habitats was assessed using filament tagging. Predation and fishing pressure across the spawning grounds was reviewed. The mid-shelf benthic habitat was found to be similar to that inshore and available for spawning. Despite the generally colder bottom temperatures on the mid-shelf, this study showed that bottom temperature in deeper waters can at times be warmer than inshore. Although mid-shelf warming events lasted from a few hours to a number of days, they resulted in similar conditions to those on the inshore spawning grounds. It is likely these events act to expand or shift spawning habitat. The movement of squid between the two spawning habitats makes it possible for them to seek patches of warm bottom water with appropiate substrate. This suggests they are spawning habitat opportunists. Predation and fishing pressure appear to be higher on the inshore spawning grounds. It is feasible that this also forces spawners to seek out more favourable habitat offshore. An individual-based model was used to predict the fate of mid-shelf and inshore hatched paralarvae. Within the model, both the highly productive cold ridge and inshore spawning grounds were considered feeding or nursery areas. Paralarvae were released from six inshore and six deep spawning sites, spanning the coast between Port Alfred and Knysna. All paralarvae not reaching the feeding areas before the exhaustion of yolk-reserves (≤5 days), not retained within the feeding grounds (≥14 days), and not retained on the Agulhas Bank after exiting the feeding grounds were considered lost. This work illustrated the dependence of paralarval transport success on both spawning location and time of hatching, as established in earlier studies. The current IBM has expanded on initial work, emphasizing the importance of the cold ridge and inshore spawning grounds as nursery areas for deep and inshore spawned paralarvae, respectively. This work has highlighted the complex interactions between processes influencing recruitment variability for chokka squid. Possible relationships between periods of highest recruitment success and spawning peaks were identified for both spawning habitats. Based on the likely autumn increase in deep spawning off Tsitsikamma, and the beneficial currents during this period, it can be concluded deep spawning may at times contribute significantly to recruitment. This is particularly true for years where the cold ridge persists into winter. Data on chokka squid paralarval distribution are scarce. Paralarval distribution and abundance, in relation to Agulhas Bank oceanography, was investigated using bongo caught paralarvae and corresponding oceanographic data. Individual-based models (IBMs) were used to predict the origin or spawning site of the wild caught paralarvae, with reference to inshore versus deep spawning. Although failing to predict realistic points of origin, this study provided evidence to support a number of scenarios previously assumed to influence chokka squid recruitment. First is the possible influence of coastal upwelling on the retention, and hence spatial distribution, of paralarvae on the inshore spawning grounds. The second factor thought to impact recruitment is the loss of paralarvae from the Agulhas Bank ecosystem. This study confirmed the removal of paralarvae from the Eastern Agulhas Bank due to Agulhas Current boundary phenomena and resultant offshelf leakage. In addition, data suggested that the formation of the cold ridge could enhance retention on the Central Agulhas Bank, and so prevent offshelf leakage from the Central and Western Agulhas Bank. A synthesis of the main conclusions is presented. Implications of the findings and directions for future research are discussed.
- Full Text:
- Date Issued: 2014
- Authors: Downey, Nicola Jean
- Date: 2014
- Subjects: Squids -- Spawning -- South Africa Squids -- Effect of temperature on -- South Africa Squids -- Embryos -- South Africa Squids -- South Africa -- Geographical distribution Loligo -- Research -- South Africa Loligo fisheries -- South Africa Recruitment (Population biology) -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5359 , http://hdl.handle.net/10962/d1011867
- Description: It was previously thought that the South African chokka squid Loligo reynaudi is exclusively an inshore, shallow water spawner. Although spawning mostly within shallow bays (<60 m) the presence of squid eggs in trawls at depths up to 130 m indicates this species frequently makes use of deeper spawning areas on the mid-shelf. The extent of mid-shelf spawning (referred to as deep spawning) and the contribution to recruitment has yet to be assessed. Studies have shown mid-shelf bottom temperature to vary considerably from those inshore, suggesting chokka squid spawn in two very different oceanographic environments. Considering these apparent environmental differences, what leads to the mid-shelf environment becoming a suitable spawning habitat? Does a suitable benthic habitat, required for the attachment of egg pods, occur on the mid-shelf? These questions are not only important for determining the extent of deep spawning, but also to the understanding of factors “driving” deep spawning. The fate of deep spawned hatchlings is another unknown. It has been proposed that the main chokka squid inshore spawning grounds are positioned to exploit the net westward currents on the Eastern Agulhas Bank, i.e. paralarvae would be transported west from the hatching site to the cold ridge, an area of high primary and secondary productivity on the Central Agulhas Bank. This concept has come to be known as the Western Transport Hypothesis. Lagrangian ROMS-IBMs (regional ocean model system – individual-based model) predict the net westward transport of paralarvae from both the inshore and deep spawning grounds, to the cold ridge. These simulations were used to investigate the transport of hatchlings to the cold ridge feeding grounds before the exhaustion of yolk reserves. The fate of paralarvae on reaching the feeding grounds has not yet been investigated. This work has contributed new knowledge to our understanding of deep spawning and its role in recruitment. Specific aims of this study were to (1) determine the extent, range and importance of the deep spawning grounds relative to those inshore; (2) investigate the deep spawning ground habitat (Agulhas Bank mid-shelf) morphology and oceanographic environment; (3) determine the transport and survival of deep spawned hatchlings; and (4) investigate the origin and distribution of chokka squid paralarvae on the Agulhas Bank. The extent, depth range and importance of the deep spawning grounds, relative to those inshore was assessed using 23 years of demersal trawl survey data. Data for both the west and south coasts of South Africa were examined for egg capsules. No spawning was found on the west coast. Data showed that chokka squid preferred the Eastern Agulhas Bank for spawning. Spawning occurred not only inshore but also on the mid-shelf extending to depths of 270 m near the shelf edge. The majority of deep spawned eggs however, were found in the depth range 71-130 m. Squid egg density markedly decreased beyond 70 m, suggesting delineation between the inshore and deep spawning grounds. Total egg biomass calculations for depths shallower and deeper than 70 m indicated the coastal area to be strongly favoured, i.e. 82 vs. 18%. These results contest the commonly accepted notion that chokka squid is an inshore spawner and redefine the spawning grounds to extend across the shelf. Apart from an initial study investigating bottom temperature on the mid-shelf, very little is known about the deep spawning habitat. St Francis Bay, a commonly used spawning location, was chosen as a demonstration area for further study. The deep spawning grounds (71-130 m) were mapped and benthic habitat described from underwater video footage. A study investigating cross-shelf bottom conditions was undertaken off Thys Bay. CTD data were used to compare seasonal bottom temperature and oxygen on the St Francis Bay inshore and deep spawning grounds. Squid movement between the two spawning habitats was assessed using filament tagging. Predation and fishing pressure across the spawning grounds was reviewed. The mid-shelf benthic habitat was found to be similar to that inshore and available for spawning. Despite the generally colder bottom temperatures on the mid-shelf, this study showed that bottom temperature in deeper waters can at times be warmer than inshore. Although mid-shelf warming events lasted from a few hours to a number of days, they resulted in similar conditions to those on the inshore spawning grounds. It is likely these events act to expand or shift spawning habitat. The movement of squid between the two spawning habitats makes it possible for them to seek patches of warm bottom water with appropiate substrate. This suggests they are spawning habitat opportunists. Predation and fishing pressure appear to be higher on the inshore spawning grounds. It is feasible that this also forces spawners to seek out more favourable habitat offshore. An individual-based model was used to predict the fate of mid-shelf and inshore hatched paralarvae. Within the model, both the highly productive cold ridge and inshore spawning grounds were considered feeding or nursery areas. Paralarvae were released from six inshore and six deep spawning sites, spanning the coast between Port Alfred and Knysna. All paralarvae not reaching the feeding areas before the exhaustion of yolk-reserves (≤5 days), not retained within the feeding grounds (≥14 days), and not retained on the Agulhas Bank after exiting the feeding grounds were considered lost. This work illustrated the dependence of paralarval transport success on both spawning location and time of hatching, as established in earlier studies. The current IBM has expanded on initial work, emphasizing the importance of the cold ridge and inshore spawning grounds as nursery areas for deep and inshore spawned paralarvae, respectively. This work has highlighted the complex interactions between processes influencing recruitment variability for chokka squid. Possible relationships between periods of highest recruitment success and spawning peaks were identified for both spawning habitats. Based on the likely autumn increase in deep spawning off Tsitsikamma, and the beneficial currents during this period, it can be concluded deep spawning may at times contribute significantly to recruitment. This is particularly true for years where the cold ridge persists into winter. Data on chokka squid paralarval distribution are scarce. Paralarval distribution and abundance, in relation to Agulhas Bank oceanography, was investigated using bongo caught paralarvae and corresponding oceanographic data. Individual-based models (IBMs) were used to predict the origin or spawning site of the wild caught paralarvae, with reference to inshore versus deep spawning. Although failing to predict realistic points of origin, this study provided evidence to support a number of scenarios previously assumed to influence chokka squid recruitment. First is the possible influence of coastal upwelling on the retention, and hence spatial distribution, of paralarvae on the inshore spawning grounds. The second factor thought to impact recruitment is the loss of paralarvae from the Agulhas Bank ecosystem. This study confirmed the removal of paralarvae from the Eastern Agulhas Bank due to Agulhas Current boundary phenomena and resultant offshelf leakage. In addition, data suggested that the formation of the cold ridge could enhance retention on the Central Agulhas Bank, and so prevent offshelf leakage from the Central and Western Agulhas Bank. A synthesis of the main conclusions is presented. Implications of the findings and directions for future research are discussed.
- Full Text:
- Date Issued: 2014
The training of artisans for house building projects in South Western Nigeria
- Authors: Oni, Oluwole Joseph
- Date: 2014
- Subjects: Skilled labor -- Nigeria , Artisans -- Training of -- Nigeria , Construction industry -- Employees -- Training of -- Nigeria , Training needs -- Nigeria
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9726 , http://hdl.handle.net/10948/d1020625
- Description: The current shortage of artisans in the Nigerian house construction sector has constrained the productivity of the sector and exacerbated the nation‟s housing problem. The persistent neglect of the artisan training system has negatively impacted on the stock of artisans available for house construction projects. Nigeria‟s large and fast-growing population of over 140 million with an estimated growth rate of 3.2 percent has engendered increased investment in shelter provision; especially by individuals and families due to fast rising housing rentals- mainly in the urban centres. Past policies have not adequately addressed the realities of the skills crisis occasioned by inadequate and neglected apprenticeship training and poorly developed vocational education and training systems. The fallout of this is manifested in the difficulties faced by developers in sourcing suitably qualified and experienced artisans for house construction projects. In response to this challenge, an upsurge of migrant artisans and craftsmen from neighbouring West African nations like Togo, Benin Republic and Ghana to Nigeria has occurred in the recent times. They were attracted by building contracting firms to fill the gap created by inadequate artisan supply that is currently being experienced locally. This development is totally unacceptable as it exacerbates the overarching socio-economic problems in Nigeria, especially the already high unemployment rate which is estimated to be 23.9 percent. This study has consequently investigated the inadequate training of house construction artisans in South Western Nigeria; evolving interventions and developing a strategic model for improving the artisan training system to ensure an adequate and sustainable artisan supply in the house construction sector. The model incorporates best practices, rethinking strategies and integrated approaches in mitigating the identified challenges. The model is underpinned by reviewed literature and empirical findings. Quantitative surveys and interviews were utilised as the data sources. The research findings show that the factors which negatively impact on the artisan training system in the house construction sector include: the poor image of artisans in society; lack of recruitment strategies for attracting potential artisans; inadequate policy framework for training and employment; a faulty and rigid National Qualification Framework (NQF); the non-participation of employers in training; a poor funding mechanism; a weak regulatory framework and corrupt practices in training administration. Recommendations for addressing the inadequate training of artisans include education policy reforms to give priority to vocational education; a new regime of funding for vocational education and training; a review of the National Qualification Framework to integrate the vocational colleges with the university system; a reform of the regulatory framework; public re-orientation on the societal image of the artisans; adoption of a new approach of public- private partnership in artisan training; the provision of incentives schemes to attract potential artisans and the appropriation of the proposed model for an integrated approach to addressing the challenges.
- Full Text:
- Date Issued: 2014
- Authors: Oni, Oluwole Joseph
- Date: 2014
- Subjects: Skilled labor -- Nigeria , Artisans -- Training of -- Nigeria , Construction industry -- Employees -- Training of -- Nigeria , Training needs -- Nigeria
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9726 , http://hdl.handle.net/10948/d1020625
- Description: The current shortage of artisans in the Nigerian house construction sector has constrained the productivity of the sector and exacerbated the nation‟s housing problem. The persistent neglect of the artisan training system has negatively impacted on the stock of artisans available for house construction projects. Nigeria‟s large and fast-growing population of over 140 million with an estimated growth rate of 3.2 percent has engendered increased investment in shelter provision; especially by individuals and families due to fast rising housing rentals- mainly in the urban centres. Past policies have not adequately addressed the realities of the skills crisis occasioned by inadequate and neglected apprenticeship training and poorly developed vocational education and training systems. The fallout of this is manifested in the difficulties faced by developers in sourcing suitably qualified and experienced artisans for house construction projects. In response to this challenge, an upsurge of migrant artisans and craftsmen from neighbouring West African nations like Togo, Benin Republic and Ghana to Nigeria has occurred in the recent times. They were attracted by building contracting firms to fill the gap created by inadequate artisan supply that is currently being experienced locally. This development is totally unacceptable as it exacerbates the overarching socio-economic problems in Nigeria, especially the already high unemployment rate which is estimated to be 23.9 percent. This study has consequently investigated the inadequate training of house construction artisans in South Western Nigeria; evolving interventions and developing a strategic model for improving the artisan training system to ensure an adequate and sustainable artisan supply in the house construction sector. The model incorporates best practices, rethinking strategies and integrated approaches in mitigating the identified challenges. The model is underpinned by reviewed literature and empirical findings. Quantitative surveys and interviews were utilised as the data sources. The research findings show that the factors which negatively impact on the artisan training system in the house construction sector include: the poor image of artisans in society; lack of recruitment strategies for attracting potential artisans; inadequate policy framework for training and employment; a faulty and rigid National Qualification Framework (NQF); the non-participation of employers in training; a poor funding mechanism; a weak regulatory framework and corrupt practices in training administration. Recommendations for addressing the inadequate training of artisans include education policy reforms to give priority to vocational education; a new regime of funding for vocational education and training; a review of the National Qualification Framework to integrate the vocational colleges with the university system; a reform of the regulatory framework; public re-orientation on the societal image of the artisans; adoption of a new approach of public- private partnership in artisan training; the provision of incentives schemes to attract potential artisans and the appropriation of the proposed model for an integrated approach to addressing the challenges.
- Full Text:
- Date Issued: 2014
Tourism management in selected municipalities in the Eden District: a theoretical study
- Authors: Lamont, Andrew John
- Date: 2014
- Subjects: Sustainable tourism -- South Africa , Tourism -- South Africa -- Management
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/8025 , vital:24460
- Description: For attainment sustainable tourism requires the growth of tourism‟s contribution to the economy and society as well as the sustainable use of resources and the environment. The achievement of both relies on dependable and sound understanding, appropriate development and management of the tourism demand. As demand patterns and economic structures change, no industry, and in particular no industry at the national or regional level, could or should assume that there is a constant or increasing flow of demand for its outputs and thus focus solely on resource issues (Butler, 1996). According to Elliot (1997:19) local government plays an important role in tourism, as it is only governments that have the authority to provide political stability, security and the legal and financial framework which tourism requires. Connell et al (2009) argue that one of the more important roles of local government is the development and implementation of community planning, legislation and policy. However, while tourism-related developments are usually integrated with economic development or official community plans, often there is no guiding policy framework or identified area of responsibility for tourism, which can be problematic for effective and sustainable tourism development. The effectiveness of local tourism governance in achieving the goals of sustainable tourism depends on the effectiveness of institutional structures and processes, and the rational resources and skill sets available (Healy, 2006). This study examines the arrangements of selected municipalities and the effectiveness of their local tourism governance and its relevance to sustainable tourism.
- Full Text:
- Date Issued: 2014
- Authors: Lamont, Andrew John
- Date: 2014
- Subjects: Sustainable tourism -- South Africa , Tourism -- South Africa -- Management
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/8025 , vital:24460
- Description: For attainment sustainable tourism requires the growth of tourism‟s contribution to the economy and society as well as the sustainable use of resources and the environment. The achievement of both relies on dependable and sound understanding, appropriate development and management of the tourism demand. As demand patterns and economic structures change, no industry, and in particular no industry at the national or regional level, could or should assume that there is a constant or increasing flow of demand for its outputs and thus focus solely on resource issues (Butler, 1996). According to Elliot (1997:19) local government plays an important role in tourism, as it is only governments that have the authority to provide political stability, security and the legal and financial framework which tourism requires. Connell et al (2009) argue that one of the more important roles of local government is the development and implementation of community planning, legislation and policy. However, while tourism-related developments are usually integrated with economic development or official community plans, often there is no guiding policy framework or identified area of responsibility for tourism, which can be problematic for effective and sustainable tourism development. The effectiveness of local tourism governance in achieving the goals of sustainable tourism depends on the effectiveness of institutional structures and processes, and the rational resources and skill sets available (Healy, 2006). This study examines the arrangements of selected municipalities and the effectiveness of their local tourism governance and its relevance to sustainable tourism.
- Full Text:
- Date Issued: 2014
Towards the development of a larval feeding strategy for the white-margined sole (Dagetichthys marginatus)
- Authors: Thompson, Ernst Frederick
- Date: 2014
- Subjects: Flatfishes -- South Africa , Soleidae -- South Africa , Soleidae -- Larvae , Soleidae -- Larvae -- Feeding and feeds , Soleidae -- Larvae -- Physiology , Artemia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5364 , http://hdl.handle.net/10962/d1012982
- Description: The major bottleneck during the domestication of the white-margined sole Dagetichthys marginatus in South Africa has been low larval survival. The cause of this is not clear but considering current literature on flatfish culture and more specifically soleid culture, nutritional deficiencies are hypothesized to be the main possible cause. Following the importance of nutrition, the first aim of the research was to use an ontogenetic developmental approach to develop a species specific larval feeding strategy. Ontogenetic development of D. marginatus showed that weaning will take place at much later ages than other soleids currently being farmed. This makes the partial replacement of Artemia with a suitable inert diet in co-feeding strategies very important to cut the cost associated of live food production. This leads on to the second aim, in which an 'in vitro' approach was used to model the digestibility of Artemia, which could ultimately contribute towards designing inert feeds with similar digestibility characteristics to Artemia in the future. Obtaining nutrients from food is closely linked to the functional status of the digestive tract, the support organs and the external morphological characteristics required for the ingestion of live or inert feeds. Considering both morphological and physiological ontogenetic development, it is clear that D. marginatus follow a similar pattern to other soleids. Larvae can successfully feed on Artemia as early as 3 days after hatching but exhibit a slow metamorphosis into the juvenile stage when compared to other soleids. The absence of any detectable acidic protease activity during the first 45 days of development and the importance of exogenous enzymes from Artemia all points to limited capacity to digest artificial diets. Prior to modelling the 'in vitro' digestion of Artemia, digestive enzyme activity at different pH's were modelled using functional forms from the normal distributive category of functions. , As there is no substantiated information for the general effects of pH on enzyme activity in the literature for finfish larvae, three species occurring in the same bio-geographical region of Dagetichthys marginatus, namely Sarpa salpa, Diplodus sargus capensis and Argyrosomus japonicus were used to investigate this effect. The fitted parameters, namely the optimal pH and sigma (the slope around the optimal pH) showed two interesting results. When using a negative log likelihood ratio test to test for differences between species for a particular enzyme, the optimal pH for alkaline proteases (7.67), lipase (8.03), amylase (7.69) and phosphatase (9.84) activity was the same for all three species. Furthermore, the study illustrated the potential to detect dietary shifts during ontogenetic development based on changes in enzyme activity around the optimal pH using the sigma parameter. Sarpa salpa showed increased amylase activity and a decrease in protease activity around the optimal pH with increased size, corresponding to a change in diet from zooplankton to algae. The 'in vitro' modelling approach taken in this study was based on known enzyme interactions and dynamics which makes the results very interpretable. from Artemia is achieved based on gut evacuation time and enzyme levels. This 'in vitro' study furthermore clearly indicates the importance of exogenous enzymes from Artemia, contributing as much as 54 percent to protein digestion and 64 – 72 percent to carbohydrate digestion. This was however, only an initial investigation, and further expansion of the model is required to achieve a complete understanding of Artemia digestion and ultimately partial replacement with artificial diets. A feeding strategy for D. marginatus should therefore follow those of other farmed soleids, although there will be a general delay in implementation due to slower development. Problems can thus be solved and improvements made by transferring technology from other soleids to D. marginatus.
- Full Text:
- Date Issued: 2014
- Authors: Thompson, Ernst Frederick
- Date: 2014
- Subjects: Flatfishes -- South Africa , Soleidae -- South Africa , Soleidae -- Larvae , Soleidae -- Larvae -- Feeding and feeds , Soleidae -- Larvae -- Physiology , Artemia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5364 , http://hdl.handle.net/10962/d1012982
- Description: The major bottleneck during the domestication of the white-margined sole Dagetichthys marginatus in South Africa has been low larval survival. The cause of this is not clear but considering current literature on flatfish culture and more specifically soleid culture, nutritional deficiencies are hypothesized to be the main possible cause. Following the importance of nutrition, the first aim of the research was to use an ontogenetic developmental approach to develop a species specific larval feeding strategy. Ontogenetic development of D. marginatus showed that weaning will take place at much later ages than other soleids currently being farmed. This makes the partial replacement of Artemia with a suitable inert diet in co-feeding strategies very important to cut the cost associated of live food production. This leads on to the second aim, in which an 'in vitro' approach was used to model the digestibility of Artemia, which could ultimately contribute towards designing inert feeds with similar digestibility characteristics to Artemia in the future. Obtaining nutrients from food is closely linked to the functional status of the digestive tract, the support organs and the external morphological characteristics required for the ingestion of live or inert feeds. Considering both morphological and physiological ontogenetic development, it is clear that D. marginatus follow a similar pattern to other soleids. Larvae can successfully feed on Artemia as early as 3 days after hatching but exhibit a slow metamorphosis into the juvenile stage when compared to other soleids. The absence of any detectable acidic protease activity during the first 45 days of development and the importance of exogenous enzymes from Artemia all points to limited capacity to digest artificial diets. Prior to modelling the 'in vitro' digestion of Artemia, digestive enzyme activity at different pH's were modelled using functional forms from the normal distributive category of functions. , As there is no substantiated information for the general effects of pH on enzyme activity in the literature for finfish larvae, three species occurring in the same bio-geographical region of Dagetichthys marginatus, namely Sarpa salpa, Diplodus sargus capensis and Argyrosomus japonicus were used to investigate this effect. The fitted parameters, namely the optimal pH and sigma (the slope around the optimal pH) showed two interesting results. When using a negative log likelihood ratio test to test for differences between species for a particular enzyme, the optimal pH for alkaline proteases (7.67), lipase (8.03), amylase (7.69) and phosphatase (9.84) activity was the same for all three species. Furthermore, the study illustrated the potential to detect dietary shifts during ontogenetic development based on changes in enzyme activity around the optimal pH using the sigma parameter. Sarpa salpa showed increased amylase activity and a decrease in protease activity around the optimal pH with increased size, corresponding to a change in diet from zooplankton to algae. The 'in vitro' modelling approach taken in this study was based on known enzyme interactions and dynamics which makes the results very interpretable. from Artemia is achieved based on gut evacuation time and enzyme levels. This 'in vitro' study furthermore clearly indicates the importance of exogenous enzymes from Artemia, contributing as much as 54 percent to protein digestion and 64 – 72 percent to carbohydrate digestion. This was however, only an initial investigation, and further expansion of the model is required to achieve a complete understanding of Artemia digestion and ultimately partial replacement with artificial diets. A feeding strategy for D. marginatus should therefore follow those of other farmed soleids, although there will be a general delay in implementation due to slower development. Problems can thus be solved and improvements made by transferring technology from other soleids to D. marginatus.
- Full Text:
- Date Issued: 2014
Towards the modeling of indigenous poultry production in the Eastern Cape Province, South Africa: characterization and extension evaluation for poverty reduction
- Yusuf, Shehu Folaranmi Gbolahan Shehu
- Authors: Yusuf, Shehu Folaranmi Gbolahan Shehu
- Date: 2014
- Subjects: Poultry -- Breeding -- South Africa -- Eastern Cape , Chickens -- Breeding -- South Africa -- Eastern Cape , Economic development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD (Agricultural Economics)
- Identifier: vital:11223 , http://hdl.handle.net/10353/d1019833 , Poultry -- Breeding -- South Africa -- Eastern Cape , Chickens -- Breeding -- South Africa -- Eastern Cape , Economic development -- South Africa -- Eastern Cape
- Description: Poverty remains a critical issue mostly in the rural South Africa. Various initiatives, policies and programs have been enacted by the government with attempting to reduce poverty at the national and provincial levels; poverty is yet to be abated. The target of the Millennium Development Goal 1 (MDG1) of halving poverty by the year 2015 notwithstanding, poverty remains a threat to quality livelihoods. Agriculture has continued to be one of the pillars of government efforts to address poverty. However, in livestock production interventions, efforts of government had largely been on cattle, sheep, goats, pigs and exotic poultry with little attention being given to indigenous poultry production (IPP). This study explores the option of using IPP to address rural poverty by capitalizing on its minimal inputs while recognizing its prevalence in a variety of households. The study addresses the characterization of the IPP from the perspectives of housing, feeding, healthcare management, breeding and marketing options.Skill competencies of the indigenous poultry farmers (IPFs) and the Agricultural Development Technicians (ADTs) were examined. This study reviewed poultry models in different parts of the world with special attention to Africa. The human resource development program of the department of rural development and agrarian reform was discussed. The study employed the use of multi-methods approach, the quantitative and qualitative research methodologies. Descriptive statistical analysis, frequent count, percentage, means, standard deviation, chisquare, and principal component analysis was used in the quantitative data analysis while the “open social system” was used for the qualitative methodology. Findings revealed that IPFs face some challenges among which are, the poor housing that exposed the birds to inclement weather, predator attacks and stock theft, high mortality of chicks after hatching and expensive feed for the flock. The IPFs showed competencies in nine skill items that included ability to identify chicken predators (x=3.92) and high yielding chickens (x=3.79); control of predators(x=3.77); methods of using ethno veterinary drugs to treat chicken diseases and pests (x=3.72), and identify signs of diseases (x=3.69), among others. However, the ADTs did not show any competency in any of the 32 skills items. The principal component analysis with Varimax rotation was performed to ascertain the dimensionality of the measures. Six factors with eigen value of >1, which accounted for 77.317% were extracted, with each factor loading ranging from 0.523 to 0.93. Factor loading after rotation that emerged on the same component was described; as brooding, shelter and care of the chicks; predators and healthcare; hygiene and litter management; feeds and feeding stuff; and record keeping and marketing. The findings on the human resource development revealed that staff meetings were the most common method of capacity development. This was followed by in-service-training, formal study, workshop, and on the job training. The farmers’ field school and study tours were sparingly used. However, respondents were in favor of on-site training, staff meetings, formal study and in-service training. The findings on the appropriate model suggest a theoretical indigenous poultry production model (IPPM) for the Eastern Cape Province (ECP). The “open social system” was used to develop a framework for an indigenous poultry cooperative society (to be known as Abafuyi Benkukhu Zemveli [ABZ]). This was meant to create a binding force for capacity development, a strong economic foundation through equity contributions, creation of marketing channels, and the development of a concept of ‘‘our own'' product in the market. Lastly, the study offers options for a training program that would accommodate the new initiatives, with a strong capacity development training approach. In this context, the study advocates for institutional support for the IPFs and the incorporation of indigenous poultry in the curriculum of the agricultural training programs at higher education institutions in South Africa.
- Full Text:
- Date Issued: 2014
- Authors: Yusuf, Shehu Folaranmi Gbolahan Shehu
- Date: 2014
- Subjects: Poultry -- Breeding -- South Africa -- Eastern Cape , Chickens -- Breeding -- South Africa -- Eastern Cape , Economic development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD (Agricultural Economics)
- Identifier: vital:11223 , http://hdl.handle.net/10353/d1019833 , Poultry -- Breeding -- South Africa -- Eastern Cape , Chickens -- Breeding -- South Africa -- Eastern Cape , Economic development -- South Africa -- Eastern Cape
- Description: Poverty remains a critical issue mostly in the rural South Africa. Various initiatives, policies and programs have been enacted by the government with attempting to reduce poverty at the national and provincial levels; poverty is yet to be abated. The target of the Millennium Development Goal 1 (MDG1) of halving poverty by the year 2015 notwithstanding, poverty remains a threat to quality livelihoods. Agriculture has continued to be one of the pillars of government efforts to address poverty. However, in livestock production interventions, efforts of government had largely been on cattle, sheep, goats, pigs and exotic poultry with little attention being given to indigenous poultry production (IPP). This study explores the option of using IPP to address rural poverty by capitalizing on its minimal inputs while recognizing its prevalence in a variety of households. The study addresses the characterization of the IPP from the perspectives of housing, feeding, healthcare management, breeding and marketing options.Skill competencies of the indigenous poultry farmers (IPFs) and the Agricultural Development Technicians (ADTs) were examined. This study reviewed poultry models in different parts of the world with special attention to Africa. The human resource development program of the department of rural development and agrarian reform was discussed. The study employed the use of multi-methods approach, the quantitative and qualitative research methodologies. Descriptive statistical analysis, frequent count, percentage, means, standard deviation, chisquare, and principal component analysis was used in the quantitative data analysis while the “open social system” was used for the qualitative methodology. Findings revealed that IPFs face some challenges among which are, the poor housing that exposed the birds to inclement weather, predator attacks and stock theft, high mortality of chicks after hatching and expensive feed for the flock. The IPFs showed competencies in nine skill items that included ability to identify chicken predators (x=3.92) and high yielding chickens (x=3.79); control of predators(x=3.77); methods of using ethno veterinary drugs to treat chicken diseases and pests (x=3.72), and identify signs of diseases (x=3.69), among others. However, the ADTs did not show any competency in any of the 32 skills items. The principal component analysis with Varimax rotation was performed to ascertain the dimensionality of the measures. Six factors with eigen value of >1, which accounted for 77.317% were extracted, with each factor loading ranging from 0.523 to 0.93. Factor loading after rotation that emerged on the same component was described; as brooding, shelter and care of the chicks; predators and healthcare; hygiene and litter management; feeds and feeding stuff; and record keeping and marketing. The findings on the human resource development revealed that staff meetings were the most common method of capacity development. This was followed by in-service-training, formal study, workshop, and on the job training. The farmers’ field school and study tours were sparingly used. However, respondents were in favor of on-site training, staff meetings, formal study and in-service training. The findings on the appropriate model suggest a theoretical indigenous poultry production model (IPPM) for the Eastern Cape Province (ECP). The “open social system” was used to develop a framework for an indigenous poultry cooperative society (to be known as Abafuyi Benkukhu Zemveli [ABZ]). This was meant to create a binding force for capacity development, a strong economic foundation through equity contributions, creation of marketing channels, and the development of a concept of ‘‘our own'' product in the market. Lastly, the study offers options for a training program that would accommodate the new initiatives, with a strong capacity development training approach. In this context, the study advocates for institutional support for the IPFs and the incorporation of indigenous poultry in the curriculum of the agricultural training programs at higher education institutions in South Africa.
- Full Text:
- Date Issued: 2014
Training of teachers in multigrade teaching: integration of vertical and horizontal knowledge in post -training
- Authors: Ganqa, Ncumisa Hazel
- Date: 2014
- Subjects: Combination of grades -- Cross-cultural studies Teachers -- In-service training Teachers
- Language: English
- Type: Thesis , Doctoral , PhD (Education)
- Identifier: http://hdl.handle.net/10353/6158 , vital:29496
- Description: The purpose of this study was to examine the training and development of teachers in multi-grade teaching in selected Eastern Cape primary schools with a particular focus on the integration of vertical and horizontal knowledge in post-training. Multigrade teaching is the combining of learners of different grade levels in one classroom taught by one teacher. To gain better understanding of the construct of vertical and horizontal integration of knowledge within post-training environment, this qualitative case study design sampled eight teachers, four school principals and three trainers, purposively. In order to evaluate the training and development provided for teachers in multi-grade classrooms the researcher examined the training programmes, the training curriculum and transfer of training inputs. The results of the study indicate that post-training is the determinant of the extent of the effectiveness of the transfer of training skills, knowledge and attitudes gained in multi-grade teaching training. The study found a massive gap that currently exists between training in multi-grade teaching and the actual transferability of such training in multi-grade contexts. Positive transfer of training in multi-grade teaching strategies was found to be skills related to teaching strategies, lesson management, curriculum integration and social components of multi-grade teaching. Negative transfer of training included classroom organisation, lesson planning, timetabling, curriculum adaptation and assessment. Although multi-grade teacher training programme is assumed to change behaviours, attitudes, impart knowledge and improve teaching skills, the results of the study indicate that training inputs might not necessarily transform into classroom practice. In order to facilitate and ensure vertical and horizontal integration of knowledge and skills and transfer of training to classroombased teaching, recurrent training in multi-grade teaching is therefore, suggested.
- Full Text:
- Date Issued: 2014
- Authors: Ganqa, Ncumisa Hazel
- Date: 2014
- Subjects: Combination of grades -- Cross-cultural studies Teachers -- In-service training Teachers
- Language: English
- Type: Thesis , Doctoral , PhD (Education)
- Identifier: http://hdl.handle.net/10353/6158 , vital:29496
- Description: The purpose of this study was to examine the training and development of teachers in multi-grade teaching in selected Eastern Cape primary schools with a particular focus on the integration of vertical and horizontal knowledge in post-training. Multigrade teaching is the combining of learners of different grade levels in one classroom taught by one teacher. To gain better understanding of the construct of vertical and horizontal integration of knowledge within post-training environment, this qualitative case study design sampled eight teachers, four school principals and three trainers, purposively. In order to evaluate the training and development provided for teachers in multi-grade classrooms the researcher examined the training programmes, the training curriculum and transfer of training inputs. The results of the study indicate that post-training is the determinant of the extent of the effectiveness of the transfer of training skills, knowledge and attitudes gained in multi-grade teaching training. The study found a massive gap that currently exists between training in multi-grade teaching and the actual transferability of such training in multi-grade contexts. Positive transfer of training in multi-grade teaching strategies was found to be skills related to teaching strategies, lesson management, curriculum integration and social components of multi-grade teaching. Negative transfer of training included classroom organisation, lesson planning, timetabling, curriculum adaptation and assessment. Although multi-grade teacher training programme is assumed to change behaviours, attitudes, impart knowledge and improve teaching skills, the results of the study indicate that training inputs might not necessarily transform into classroom practice. In order to facilitate and ensure vertical and horizontal integration of knowledge and skills and transfer of training to classroombased teaching, recurrent training in multi-grade teaching is therefore, suggested.
- Full Text:
- Date Issued: 2014
Triggering physics lecturers' reflections on the instructional affordance of their use of representations: a design-based study
- Authors: Lombard, Elsa Helena
- Date: 2014
- Subjects: Physics -- Study and teaching , Physics -- Research
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/2899 , vital:20361
- Description: There is growing awareness in the physics education research community about the importance of using representations in physics teaching and the need for lecturers to reflect on their practice. This research study adopted a design-based research approach in an attempt to design a reliable, valid and practically useful artefact (framework/strategy) that could be used to trigger introductory physics lecturers’ reflections on their instructional use of representations. The artefact, which was instantiated with physics lecturers, comprised an observation protocol, an accompanying definitions key, a communication platform, and an instrument to assess the outcome (the levels of reflection). The video-data of lecturer practice were analysed using a priori codes to generate profiles of teaching practice. The resulting profiles were used to trigger individual video-stimulated reflection. The levels of reflection were assessed using a purpose-designed ‘Expectations of Reflection’ taxonomy. Thereafter a set of design guidelines and design principles were generated to guide further similar design-based educational studies. The process was validated via interview data but, while it was deemed a valid and reliable solution to the research problem, there were varying levels of perceived value of the artefact among the participating lecturers.
- Full Text:
- Date Issued: 2014
- Authors: Lombard, Elsa Helena
- Date: 2014
- Subjects: Physics -- Study and teaching , Physics -- Research
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/2899 , vital:20361
- Description: There is growing awareness in the physics education research community about the importance of using representations in physics teaching and the need for lecturers to reflect on their practice. This research study adopted a design-based research approach in an attempt to design a reliable, valid and practically useful artefact (framework/strategy) that could be used to trigger introductory physics lecturers’ reflections on their instructional use of representations. The artefact, which was instantiated with physics lecturers, comprised an observation protocol, an accompanying definitions key, a communication platform, and an instrument to assess the outcome (the levels of reflection). The video-data of lecturer practice were analysed using a priori codes to generate profiles of teaching practice. The resulting profiles were used to trigger individual video-stimulated reflection. The levels of reflection were assessed using a purpose-designed ‘Expectations of Reflection’ taxonomy. Thereafter a set of design guidelines and design principles were generated to guide further similar design-based educational studies. The process was validated via interview data but, while it was deemed a valid and reliable solution to the research problem, there were varying levels of perceived value of the artefact among the participating lecturers.
- Full Text:
- Date Issued: 2014
Trophic relationships of hake (Merluccius capensis Castelnau, 1851 and M. paradoxus Franca 1960) from the Northern Benguela current ecosystem (Namibia) : inferences from stable isotopes and fatty acids
- Authors: Iitembu, Johannes Angala
- Date: 2014
- Subjects: Hake -- Benguela Current , Merlucciidae -- Benguela Current , Multitrophic interactions (Ecology) , Food chains (Ecology) , Biotic communities -- Benguela Current , Merlucciidae -- Food , Fishery management -- Namibia , Stable isotopes , Fatty acids
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5944 , http://hdl.handle.net/10962/d1020296
- Description: Two species of hake (Merluccius capensis and Merluccius paradoxus) account for most of Namibia’s fisheries catch, and they are important secondary consumers in the Benguela Current ecosystem. Inferences on their trophic relationships have been based mainly on stomach content analyses. However, such data are limited temporally because they represent only snapshots of recent feeding, and are quantitatively biased because of variation in the digestion rates of different prey. The principal aim of the thesis was to understand the trophic relationships of two hake species relative to each other, their known prey and top predators (demersal sharks) in the northern Benguela Current ecosystem (Namibia), using time-integrating trophic biomarkers. By using stable isotope (carbon and nitrogen) and fatty acid signatures of their muscle tissues, my overall objectives were to produce new knowledge about 1) hake ontogenic trophic relationships, 2) the contributions of different prey to hake diets, 3) hake dietary differences, and 4) some aspects of hake’s trophic relationships with demersal sharks. Tissues of hake (n=358), their potential prey (n=455), and demersal sharks (n=42) were collected between 2008 and 2012 during demersal bottom trawl surveys off Namibia, for stable isotope and fatty acid analyses. And more...
- Full Text:
- Date Issued: 2014
- Authors: Iitembu, Johannes Angala
- Date: 2014
- Subjects: Hake -- Benguela Current , Merlucciidae -- Benguela Current , Multitrophic interactions (Ecology) , Food chains (Ecology) , Biotic communities -- Benguela Current , Merlucciidae -- Food , Fishery management -- Namibia , Stable isotopes , Fatty acids
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5944 , http://hdl.handle.net/10962/d1020296
- Description: Two species of hake (Merluccius capensis and Merluccius paradoxus) account for most of Namibia’s fisheries catch, and they are important secondary consumers in the Benguela Current ecosystem. Inferences on their trophic relationships have been based mainly on stomach content analyses. However, such data are limited temporally because they represent only snapshots of recent feeding, and are quantitatively biased because of variation in the digestion rates of different prey. The principal aim of the thesis was to understand the trophic relationships of two hake species relative to each other, their known prey and top predators (demersal sharks) in the northern Benguela Current ecosystem (Namibia), using time-integrating trophic biomarkers. By using stable isotope (carbon and nitrogen) and fatty acid signatures of their muscle tissues, my overall objectives were to produce new knowledge about 1) hake ontogenic trophic relationships, 2) the contributions of different prey to hake diets, 3) hake dietary differences, and 4) some aspects of hake’s trophic relationships with demersal sharks. Tissues of hake (n=358), their potential prey (n=455), and demersal sharks (n=42) were collected between 2008 and 2012 during demersal bottom trawl surveys off Namibia, for stable isotope and fatty acid analyses. And more...
- Full Text:
- Date Issued: 2014
Understanding and modelling of surface and groundwater interactions
- Authors: Tanner, Jane Louise
- Date: 2014
- Subjects: Groundwater -- South Africa , Water-supply -- Management , Integrated water development , Hydrogeology , Water resources development -- South Africa , Water -- Analysis , Groundwater -- Management , Watersheds -- South Africa , Hydrologic models
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:6043 , http://hdl.handle.net/10962/d1012994
- Description: The connections between surface water and groundwater systems remain poorly understood in many catchments throughout the world and yet they are fundamental to effectively managing water resources. Managing water resources in an integrated manner is not straightforward, particularly if both resources are being utilised, and especially in those regions that suffer problems of data scarcity. This study explores some of the principle issues associated with understanding and practically modelling surface and groundwater interactions. In South Africa, there remains much controversy over the most appropriate type of integrated model to be used and the way forward in terms of the development of the discipline; part of the disagreement stems from the fact that we cannot validate models adequately. This is largely due to traditional forms of model testing having limited power as it is difficult to differentiate between the uncertainties within different model structures, different sets of alternative parameter values and in the input data used to run the model. While model structural uncertainties are important to consider, the uncertainty from input data error together with parameter estimation error are often more significant to the overall residual error, and essential to consider if we want to achieve reliable predictions for water resource decisions. While new philosophies and theories on modelling and results validation have been developed (Beven, 2002; Gupta et al., 2008), in many cases models are not only still being validated and compared using sparse and uncertain datasets, but also expected to produce reliable predictions based on the flawed data. The approach in this study is focused on fundamental understanding of hydrological systems rather than calibration based modelling and promotes the use of all the available 'hard' and 'soft' data together with thoughtful conceptual examination of the processes occurring in an environment to ensure as far as possible that a model is generating sensible results by simulating the correct processes. The first part of the thesis focuses on characterising the 'typical' interaction environments found in South Africa. It was found that many traditional perceptual models are not necessarily applicable to South African conditions, largely due to the relative importance of unsaturated zone processes and the complexity of the dominantly fractured rock environments. The interaction environments were categorised into four main 'types' of environment. These include karst, primary, fractured rock (secondary), and alluvial environments. Processes critical to Integrated Water Resource Management (IWRM) were defined within each interaction type as a guideline to setting a model up to realistically represent the dominant processes in the respective settings. The second part of the thesis addressed the application and evaluation of the modified Pitman model (Hughes, 2004), which allows for surface and groundwater interaction behaviour at the catchment scale to be simulated. The issue is whether, given the different sources of uncertainty in the modelling process, we can differentiate one conceptual flow path from another in trying to refine the understanding and consequently have more faith in model predictions. Seven example catchments were selected from around South Africa to assess whether reliable integrated assessments can be carried out given the existing data. Specific catchment perceptual models were used to identify the critical processes occurring in each setting and the Pitman model was assessed on whether it could represent them (structural uncertainty). The available knowledge of specific environments or catchments was then examined in an attempt to resolve the parameter uncertainty present within each catchment and ensure the subsequent model setup was correctly representing the process understanding as far as possible. The confidence in the quantitative results inevitably varied with the amount and quality of the data available. While the model was deemed to be robust based on the behavioural results obtained in the majority of the case studies, in many cases a quantitative validation of the outputs was just not possible based on the available data. In these cases, the model was judged on its ability to represent the conceptualisation of the processes occurring in the catchments. While the lack of appropriate data means there will always be considerable uncertainty surrounding model validation, it can be argued that improved process understanding in an environment can be used to validate model outcomes to a degree, by assessing whether a model is getting the right results for the right reasons. Many water resource decisions are still made without adequate account being taken of the uncertainties inherent in assessing the response of hydrological systems. Certainly, with all the possible sources of uncertainty in a data scarce country such as South Africa, pure calibration based modelling is unlikely to produce reliable information for water resource managers as it can produce the right results for the wrong reasons. Thus it becomes essential to incorporate conceptual thinking into the modelling process, so that at the very least we are able to conclude that a model generates estimates that are consistent with, and reflect, our understanding (however limited) of the catchment processes. It is fairly clear that achieving the optimum model of a hydrological system may be fraught with difficulty, if not impossible. This makes it very difficult from a practitioner's point of view to decide which model and uncertainty estimation method to use. According to Beven (2009), this may be a transitional problem and in the future it may become clearer as we learn more about how to estimate the uncertainties associated with hydrological systems. Until then, a better understanding of the fundamental and most critical hydrogeological processes should be used to critically test and improve model predictions as far as possible. A major focus of the study was to identify whether the modified Pitman model could provide a practical tool for water resource managers by reliably determining the available water resource. The incorporation of surface and groundwater interaction routines seems to have resulted in a more robust and realistic model of basin hydrology. The overall conclusion is that the model, although simplified, is capable of representing the catchment scale processes that occur under most South African conditions.
- Full Text:
- Date Issued: 2014
- Authors: Tanner, Jane Louise
- Date: 2014
- Subjects: Groundwater -- South Africa , Water-supply -- Management , Integrated water development , Hydrogeology , Water resources development -- South Africa , Water -- Analysis , Groundwater -- Management , Watersheds -- South Africa , Hydrologic models
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:6043 , http://hdl.handle.net/10962/d1012994
- Description: The connections between surface water and groundwater systems remain poorly understood in many catchments throughout the world and yet they are fundamental to effectively managing water resources. Managing water resources in an integrated manner is not straightforward, particularly if both resources are being utilised, and especially in those regions that suffer problems of data scarcity. This study explores some of the principle issues associated with understanding and practically modelling surface and groundwater interactions. In South Africa, there remains much controversy over the most appropriate type of integrated model to be used and the way forward in terms of the development of the discipline; part of the disagreement stems from the fact that we cannot validate models adequately. This is largely due to traditional forms of model testing having limited power as it is difficult to differentiate between the uncertainties within different model structures, different sets of alternative parameter values and in the input data used to run the model. While model structural uncertainties are important to consider, the uncertainty from input data error together with parameter estimation error are often more significant to the overall residual error, and essential to consider if we want to achieve reliable predictions for water resource decisions. While new philosophies and theories on modelling and results validation have been developed (Beven, 2002; Gupta et al., 2008), in many cases models are not only still being validated and compared using sparse and uncertain datasets, but also expected to produce reliable predictions based on the flawed data. The approach in this study is focused on fundamental understanding of hydrological systems rather than calibration based modelling and promotes the use of all the available 'hard' and 'soft' data together with thoughtful conceptual examination of the processes occurring in an environment to ensure as far as possible that a model is generating sensible results by simulating the correct processes. The first part of the thesis focuses on characterising the 'typical' interaction environments found in South Africa. It was found that many traditional perceptual models are not necessarily applicable to South African conditions, largely due to the relative importance of unsaturated zone processes and the complexity of the dominantly fractured rock environments. The interaction environments were categorised into four main 'types' of environment. These include karst, primary, fractured rock (secondary), and alluvial environments. Processes critical to Integrated Water Resource Management (IWRM) were defined within each interaction type as a guideline to setting a model up to realistically represent the dominant processes in the respective settings. The second part of the thesis addressed the application and evaluation of the modified Pitman model (Hughes, 2004), which allows for surface and groundwater interaction behaviour at the catchment scale to be simulated. The issue is whether, given the different sources of uncertainty in the modelling process, we can differentiate one conceptual flow path from another in trying to refine the understanding and consequently have more faith in model predictions. Seven example catchments were selected from around South Africa to assess whether reliable integrated assessments can be carried out given the existing data. Specific catchment perceptual models were used to identify the critical processes occurring in each setting and the Pitman model was assessed on whether it could represent them (structural uncertainty). The available knowledge of specific environments or catchments was then examined in an attempt to resolve the parameter uncertainty present within each catchment and ensure the subsequent model setup was correctly representing the process understanding as far as possible. The confidence in the quantitative results inevitably varied with the amount and quality of the data available. While the model was deemed to be robust based on the behavioural results obtained in the majority of the case studies, in many cases a quantitative validation of the outputs was just not possible based on the available data. In these cases, the model was judged on its ability to represent the conceptualisation of the processes occurring in the catchments. While the lack of appropriate data means there will always be considerable uncertainty surrounding model validation, it can be argued that improved process understanding in an environment can be used to validate model outcomes to a degree, by assessing whether a model is getting the right results for the right reasons. Many water resource decisions are still made without adequate account being taken of the uncertainties inherent in assessing the response of hydrological systems. Certainly, with all the possible sources of uncertainty in a data scarce country such as South Africa, pure calibration based modelling is unlikely to produce reliable information for water resource managers as it can produce the right results for the wrong reasons. Thus it becomes essential to incorporate conceptual thinking into the modelling process, so that at the very least we are able to conclude that a model generates estimates that are consistent with, and reflect, our understanding (however limited) of the catchment processes. It is fairly clear that achieving the optimum model of a hydrological system may be fraught with difficulty, if not impossible. This makes it very difficult from a practitioner's point of view to decide which model and uncertainty estimation method to use. According to Beven (2009), this may be a transitional problem and in the future it may become clearer as we learn more about how to estimate the uncertainties associated with hydrological systems. Until then, a better understanding of the fundamental and most critical hydrogeological processes should be used to critically test and improve model predictions as far as possible. A major focus of the study was to identify whether the modified Pitman model could provide a practical tool for water resource managers by reliably determining the available water resource. The incorporation of surface and groundwater interaction routines seems to have resulted in a more robust and realistic model of basin hydrology. The overall conclusion is that the model, although simplified, is capable of representing the catchment scale processes that occur under most South African conditions.
- Full Text:
- Date Issued: 2014
Vulnerability and adaptation of Zanzibar east coast communities to climate variability and change and other interacting stressors
- Authors: Makame, Makame Omar
- Date: 2014
- Subjects: Climatic changes -- Tanzania -- Zanzibar Bioclimatology Global temperature changes Food security -- Tanzania -- Zanzibar Water-supply -- Tanzania -- Zanzibar Sustainable development -- Tanzania -- Zanzibar Climatic changes -- Social aspects -- Tanzania -- Zanzibar Human ecology -- Tanzania -- Zanzibar Zanzibar -- Economic conditions
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4778 , http://hdl.handle.net/10962/d1011895
- Description: Climate variability and change as well as sea level rise poses significant challenges to livelihoods, water and food security in small island developing states (SIDSs) including the Zanzibar Islands. Thus, without planned strategic adaptation, the future projected changes in climate and sea level will intensify the vulnerability of these sensitive areas. This thesis is based on research conducted in two sites located in the north eastern parts of each island, namely Kiuyu Mbuyuni, Pemba Island and Matemwe, Unguja Island. The research focused firstly on assessing the vulnerability of these two coastal communities to climate variability and change and other stressors. This included investigation of (1) the perceptions of fishers, farmers and seaweed farmers regarding climate stressors and shocks and associated risks and impacts, (2) existing and possible future water and food security issues, and (3) household's access to important livelihood assets. This was followed by an exploration of the coping and adaptive responses of farmers, fishers and seaweed farmers to perceived shocks and stresses and some of the barriers to these responses. Lastly, an analysis of the implications of the findings for achieving sustainable coastal livelihoods and a resilient coastal community was undertaken. The general picture that emerges is that local people along the east coasts of both islands are already vulnerable to a wide range of stressors. Although variability in rainfall is not a new phenomenon in these areas, increasing frequency of dry spells and coastal floods resulting from the influence of El Niño and La Niña events exert enormous pressures on local activities (fishing, farming and seaweed farming) which are the crux of the local economy. The main argument of the study is that the nature and characteristics of these activities are the main source of sensitivity amongst these communities and this creates high levels of vulnerability to climate shocks and trends. This vulnerability is evidenced by the reoccurrence of localised food shortages and the observed food and water insecurity. The study found that food insecurity is a result of unreliable rainfall, drought and seasonality changes. These interacted with other contextual factors such as poor soil, low purchasing power and the lack of livelihood diversification options. In addition to exposure to these almost unavoidable risks from climate variability, the vulnerability of the local communities along the east coasts is also influenced by the low level of capital stocks and limited access to the assets that are important for coping and adaptation. Despite this, some households managed to overcome barriers and adapt in various ways both within the three main livelihood sectors (fishing, farming and seaweed farming) as well as through adopting options outside these sectors resulting in diversification of the livelihood portfolio. However, the study found that most of the strategies opted for by fishers, farmers and seaweed farmers were mainly spontaneous. Few planned adaptation measures supported by state authorities were observed across the sites, with the exception of the provision of motorised boats which were specifically meant to increase physical assets amongst fishers, reduce pressure in the marine conservation areas and prevent overfishing in-shore. Furthermore, numerous strategies that people adopted were discontinued when further barriers were encountered. Interestingly, some of the barriers that prevented households adapting were the same ones that forced households that had responded to abandon their adaptations. To increase resilience amongst east coast communities to current and future predicted changes in climate and sea level, the study argues that traditional livelihood activities (fishing, farming and seaweed farming) need to be better supported, and access to a range of livelihood assets improved. This may be achieved through increased access to local sources of water and facilitation of rainwater harvesting, expanding the livelihood options available to people and increasing climate change awareness, and access to sources of credit.
- Full Text:
- Date Issued: 2014
- Authors: Makame, Makame Omar
- Date: 2014
- Subjects: Climatic changes -- Tanzania -- Zanzibar Bioclimatology Global temperature changes Food security -- Tanzania -- Zanzibar Water-supply -- Tanzania -- Zanzibar Sustainable development -- Tanzania -- Zanzibar Climatic changes -- Social aspects -- Tanzania -- Zanzibar Human ecology -- Tanzania -- Zanzibar Zanzibar -- Economic conditions
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4778 , http://hdl.handle.net/10962/d1011895
- Description: Climate variability and change as well as sea level rise poses significant challenges to livelihoods, water and food security in small island developing states (SIDSs) including the Zanzibar Islands. Thus, without planned strategic adaptation, the future projected changes in climate and sea level will intensify the vulnerability of these sensitive areas. This thesis is based on research conducted in two sites located in the north eastern parts of each island, namely Kiuyu Mbuyuni, Pemba Island and Matemwe, Unguja Island. The research focused firstly on assessing the vulnerability of these two coastal communities to climate variability and change and other stressors. This included investigation of (1) the perceptions of fishers, farmers and seaweed farmers regarding climate stressors and shocks and associated risks and impacts, (2) existing and possible future water and food security issues, and (3) household's access to important livelihood assets. This was followed by an exploration of the coping and adaptive responses of farmers, fishers and seaweed farmers to perceived shocks and stresses and some of the barriers to these responses. Lastly, an analysis of the implications of the findings for achieving sustainable coastal livelihoods and a resilient coastal community was undertaken. The general picture that emerges is that local people along the east coasts of both islands are already vulnerable to a wide range of stressors. Although variability in rainfall is not a new phenomenon in these areas, increasing frequency of dry spells and coastal floods resulting from the influence of El Niño and La Niña events exert enormous pressures on local activities (fishing, farming and seaweed farming) which are the crux of the local economy. The main argument of the study is that the nature and characteristics of these activities are the main source of sensitivity amongst these communities and this creates high levels of vulnerability to climate shocks and trends. This vulnerability is evidenced by the reoccurrence of localised food shortages and the observed food and water insecurity. The study found that food insecurity is a result of unreliable rainfall, drought and seasonality changes. These interacted with other contextual factors such as poor soil, low purchasing power and the lack of livelihood diversification options. In addition to exposure to these almost unavoidable risks from climate variability, the vulnerability of the local communities along the east coasts is also influenced by the low level of capital stocks and limited access to the assets that are important for coping and adaptation. Despite this, some households managed to overcome barriers and adapt in various ways both within the three main livelihood sectors (fishing, farming and seaweed farming) as well as through adopting options outside these sectors resulting in diversification of the livelihood portfolio. However, the study found that most of the strategies opted for by fishers, farmers and seaweed farmers were mainly spontaneous. Few planned adaptation measures supported by state authorities were observed across the sites, with the exception of the provision of motorised boats which were specifically meant to increase physical assets amongst fishers, reduce pressure in the marine conservation areas and prevent overfishing in-shore. Furthermore, numerous strategies that people adopted were discontinued when further barriers were encountered. Interestingly, some of the barriers that prevented households adapting were the same ones that forced households that had responded to abandon their adaptations. To increase resilience amongst east coast communities to current and future predicted changes in climate and sea level, the study argues that traditional livelihood activities (fishing, farming and seaweed farming) need to be better supported, and access to a range of livelihood assets improved. This may be achieved through increased access to local sources of water and facilitation of rainwater harvesting, expanding the livelihood options available to people and increasing climate change awareness, and access to sources of credit.
- Full Text:
- Date Issued: 2014
Wild vegetables of the Eastern Cape of South Africa: the nutritional value and domestication of solanum nigrum l
- Authors: Bvenura, Callistus
- Date: 2014
- Language: English
- Type: Thesis , Doctoral , PhD (Ethnobotany)
- Identifier: vital:11885 , http://hdl.handle.net/10353/d1015514
- Description: An ethnobotanical survey was conducted in Alice and Willowvale in the Nkonkobe and Mbashe municipalities of the Eastern Cape Province, South Africa to identify and document wild vegetables growing in the areas. The survey documented 22 vegetable species belonging to 12 different families. The Amaryllidaceae, Amaranthaceae, Apiaceae, Asteraceae, Caryophyllaceae, Chenopodiaceae, Convolvulaceae, Cruciferae, Cucurbitaceaea, Euphorbiaceae, Tiliaceae, Solanaceae, Polygonaceae and Urticaceae were the families that were recorded. The species were Tulbaghia violacea Harv., Amaranthus blitoides S., Amaranthus blitum L., Amaranthus hybridus L., Centella coriacea Nannfd., Bidens pilosa L, Cotula heterocarpa DC., Sonchus oleraceus L., Galinsoga parviflora Cav., Taraxacum officinale Weber, Hypochaeris radicata L., Stellaria media L., Chenopodium album L., Chenopodium murale L., Ipomoea batatas L., Sisymbrium thellungii O. Schulz, Cucurbita pepo L., Rumex crispus L., Acalypha virginica L., Nicandra physalodes L., Physalis peruviana L., Solanum nigrum L., Urtica urens L. and Corchorus olitorius L. About 27 % of the wild vegetables were native to South Africa and about 45 % were also used as medicinal plants in the areas. Sun drying was the most common method of preserving the wild vegetables for the off season months. This study also revealed that, men and the younger generation knew less about wild vegetables than the women. The study also revealed a loss of knowledge of wild vegetables and their use by the rural dwellers who are more in favour of the exotic types such as spinach and cabbage.
- Full Text:
- Date Issued: 2014
- Authors: Bvenura, Callistus
- Date: 2014
- Language: English
- Type: Thesis , Doctoral , PhD (Ethnobotany)
- Identifier: vital:11885 , http://hdl.handle.net/10353/d1015514
- Description: An ethnobotanical survey was conducted in Alice and Willowvale in the Nkonkobe and Mbashe municipalities of the Eastern Cape Province, South Africa to identify and document wild vegetables growing in the areas. The survey documented 22 vegetable species belonging to 12 different families. The Amaryllidaceae, Amaranthaceae, Apiaceae, Asteraceae, Caryophyllaceae, Chenopodiaceae, Convolvulaceae, Cruciferae, Cucurbitaceaea, Euphorbiaceae, Tiliaceae, Solanaceae, Polygonaceae and Urticaceae were the families that were recorded. The species were Tulbaghia violacea Harv., Amaranthus blitoides S., Amaranthus blitum L., Amaranthus hybridus L., Centella coriacea Nannfd., Bidens pilosa L, Cotula heterocarpa DC., Sonchus oleraceus L., Galinsoga parviflora Cav., Taraxacum officinale Weber, Hypochaeris radicata L., Stellaria media L., Chenopodium album L., Chenopodium murale L., Ipomoea batatas L., Sisymbrium thellungii O. Schulz, Cucurbita pepo L., Rumex crispus L., Acalypha virginica L., Nicandra physalodes L., Physalis peruviana L., Solanum nigrum L., Urtica urens L. and Corchorus olitorius L. About 27 % of the wild vegetables were native to South Africa and about 45 % were also used as medicinal plants in the areas. Sun drying was the most common method of preserving the wild vegetables for the off season months. This study also revealed that, men and the younger generation knew less about wild vegetables than the women. The study also revealed a loss of knowledge of wild vegetables and their use by the rural dwellers who are more in favour of the exotic types such as spinach and cabbage.
- Full Text:
- Date Issued: 2014