A study on the role of the media in identity formation among isiXhosa speaking youth in Grahamstown with focus on SABC’s Yo TV
- Authors: Mabusela, Pumeza
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3661 , http://hdl.handle.net/10962/d1021302
- Description: This study explores the use of African languages, more specifically isiXhosa, in the South African Broadcasting Corporation (SABC). It does this by investigating the YO TV programme and its impact on identity formation amongst isiXhosa speaking youth. The research was conducted in Grahamstown which is located in the Eastern Cape province of South Africa. Young isiXhosa speakers were used as participants for questionnaires and focus group interviews. The location of the study within the Eastern Cape was driven by the fact that Grahamstown consists of mainly isiXhosa speakers, and young people are a big part of the population. Secondly, the participants were chosen in order to look at how isiXhosa and the Xhosa culture are represented in the YO TV programme through the lenses of young people who speak the language, and whether the representation of these two aspects plays a role in the formation of their identity. The goals of the research were to explore the relationship between language and youth identity, and the role of television in the construction of this identity. The research looked at the SABC’s YO TV which is a youth programme targeting South African youth who speak different languages and the role it plays in constructing the identity of isiXhosa speaking youth in relation to language and culture. It also examined for what purpose isiXhosa was used in the YO TV programme. The study further identified and critically analysed the already existing strategies used by the SABC to promote African languages in youth programs. The study made several findings, one of these being that there is a relationship that exists between language, culture and identity. As a result of this relationship, this study found that when one of these aspects is less represented on television, it affects the other(s). Thus, little representation of isiXhosa on YO TV has an impact on the identity formation of young isiXhosa speakers as they believe that language and culture are a part of who they are, their identity. This study also discovered that institutions of power such as the media play a key role in affirming the identity of young people. They play a role in influencing the way young people reason and do things. This study argues that television programmes such as the YO TV programme must use African languages, as well as English because the use of African languages adds value to how young people perceive them. The use of African languages on television will contribute to their growth and development. Moreover, the use of these languages in the media contributes in identity construction of young African language speakers.
- Full Text:
- Authors: Mabusela, Pumeza
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3661 , http://hdl.handle.net/10962/d1021302
- Description: This study explores the use of African languages, more specifically isiXhosa, in the South African Broadcasting Corporation (SABC). It does this by investigating the YO TV programme and its impact on identity formation amongst isiXhosa speaking youth. The research was conducted in Grahamstown which is located in the Eastern Cape province of South Africa. Young isiXhosa speakers were used as participants for questionnaires and focus group interviews. The location of the study within the Eastern Cape was driven by the fact that Grahamstown consists of mainly isiXhosa speakers, and young people are a big part of the population. Secondly, the participants were chosen in order to look at how isiXhosa and the Xhosa culture are represented in the YO TV programme through the lenses of young people who speak the language, and whether the representation of these two aspects plays a role in the formation of their identity. The goals of the research were to explore the relationship between language and youth identity, and the role of television in the construction of this identity. The research looked at the SABC’s YO TV which is a youth programme targeting South African youth who speak different languages and the role it plays in constructing the identity of isiXhosa speaking youth in relation to language and culture. It also examined for what purpose isiXhosa was used in the YO TV programme. The study further identified and critically analysed the already existing strategies used by the SABC to promote African languages in youth programs. The study made several findings, one of these being that there is a relationship that exists between language, culture and identity. As a result of this relationship, this study found that when one of these aspects is less represented on television, it affects the other(s). Thus, little representation of isiXhosa on YO TV has an impact on the identity formation of young isiXhosa speakers as they believe that language and culture are a part of who they are, their identity. This study also discovered that institutions of power such as the media play a key role in affirming the identity of young people. They play a role in influencing the way young people reason and do things. This study argues that television programmes such as the YO TV programme must use African languages, as well as English because the use of African languages adds value to how young people perceive them. The use of African languages on television will contribute to their growth and development. Moreover, the use of these languages in the media contributes in identity construction of young African language speakers.
- Full Text:
Petrogenetic implications for the Merensky Reef: a platinum-group element distribution study from wide-reef facies in the western Bushveld Complex, RSA
- Authors: Largatzis, Savvas Anthony
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3167 , vital:20380
- Description: Despite decades of research and its economic importance, the formation of the Merensky Reef still remains controversial. This study reports on the distribution of platinum-group elements within widereef facies in an attempt to identify petrogenetic controls in the formation of the Merensky Reef. Widereef Merensky was sampled from Eland Platinum Mines in the western Bushveld. Macroscopic investigation of the drillcore identified a basal chromitite stringer overlying an anorthositic footwall. The reef comprised a pyroxenite unit while the hangingwall comprised noritic, leuconoritic and anorthositic units (upwards the stratigraphy). Furthermore, an anorthositic seam was identified within the pyroxenite reef, near the top of the unit. Ophitic textures of orthopyroxene oikocrysts comprising inclusions of plagioclase chadacrysts suggest that the crystallization of plagioclase preceded the crystallization of orthopyroxene. Furthermore, plagioclase and orthopyroxene were shown to be in mineral disequilibrium with one another. Pervasive hydrous alteration features throughout the Merensky Reef suggest late stage deuteric alteration. Mineral chemistry of plagioclase cores recorded ranges for An content in the Merensky Reef as follows: An72-79 in the anorthositic footwall, An71-77 in the chromitite stringer, An45-78 in the pyroxenite reef unit, An47-73 in the anorthosite reef unit, An72-76 in the norite hangingwall, An75-77 in the leuconorite hangingwall and An72-77 in the anorthosite hangingwall. This suggest that the reef units were more evolved than the footwall and hangingwall units. Furthermore, plagioclase showed reverse zoning in the anorthosite footwall unit while normal zoning was identified in the anorthosite reef unit. This suggested that the footwall unit underwent reheating and re-equilibration with a hotter, more primitive magma (also evident in recrystallization textures) while the anorthositic reef unit cooled relatively slowly and interstitial plagioclase present within this unit equilibrated with a trapped, more evolved liquid. The pyroxenite reef unit shows enrichment in incompatible elements and corresponding negative Eu anomalies, indicating the presence of trapped liquids. Cu, Ni and S concentrations remained low throughout the reef with the exception of a peak underlying the anorthositic seam and further enrichment underlying this peak. Platinum-group element geochemistry identified two major peaks: an upper peak which coincided with the peaks for Cu, Ni and S, and showed preferential enrichment in Pd and Au relative to other PGE, and a lower peak which coincided with the presence of chromitite and showed the preferential enrichment of Os, Ir, Ru, Rh and Pt relative to Pd, Au, Cu and Ni. The formation of the lower peak was consistent with a model involving the co-precipitation of chromite and PGE clusters (as PGM) while the upper peak was attributed to a model involving the collection of PGE by an immiscible sulphide liquid. Moreover, high Cu/Pd and Pt/Pd ratios in the lower pyroxenite unit indicated a process involving sulphide fractional segregation and scavenging while the inverse, present within the upper pyroxenite unit, suggested a more dynamic system involving the introduction of PGE-undepleted magma and S during simultaneous sulphide precipitation. Furthermore, a separation of PPGE peaks from IPGE peaks was observed within the pyroxenite unit, indicating a different partitioning behavior between PPGE and IPGE. The separation of these peaks is attributed to a sulphide liquid fractionation model while depletion haloes occurring in the proximity of the main PGE peaks was suggested to form through an Ostwald-ripening type mechanism. The results of this study are consistent with a model for the formation of the Merensky Reef involving a combination of geochemical processes, including sulphide segregation and fractionation, as well as multiple replenishments of magma.
- Full Text:
- Authors: Largatzis, Savvas Anthony
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3167 , vital:20380
- Description: Despite decades of research and its economic importance, the formation of the Merensky Reef still remains controversial. This study reports on the distribution of platinum-group elements within widereef facies in an attempt to identify petrogenetic controls in the formation of the Merensky Reef. Widereef Merensky was sampled from Eland Platinum Mines in the western Bushveld. Macroscopic investigation of the drillcore identified a basal chromitite stringer overlying an anorthositic footwall. The reef comprised a pyroxenite unit while the hangingwall comprised noritic, leuconoritic and anorthositic units (upwards the stratigraphy). Furthermore, an anorthositic seam was identified within the pyroxenite reef, near the top of the unit. Ophitic textures of orthopyroxene oikocrysts comprising inclusions of plagioclase chadacrysts suggest that the crystallization of plagioclase preceded the crystallization of orthopyroxene. Furthermore, plagioclase and orthopyroxene were shown to be in mineral disequilibrium with one another. Pervasive hydrous alteration features throughout the Merensky Reef suggest late stage deuteric alteration. Mineral chemistry of plagioclase cores recorded ranges for An content in the Merensky Reef as follows: An72-79 in the anorthositic footwall, An71-77 in the chromitite stringer, An45-78 in the pyroxenite reef unit, An47-73 in the anorthosite reef unit, An72-76 in the norite hangingwall, An75-77 in the leuconorite hangingwall and An72-77 in the anorthosite hangingwall. This suggest that the reef units were more evolved than the footwall and hangingwall units. Furthermore, plagioclase showed reverse zoning in the anorthosite footwall unit while normal zoning was identified in the anorthosite reef unit. This suggested that the footwall unit underwent reheating and re-equilibration with a hotter, more primitive magma (also evident in recrystallization textures) while the anorthositic reef unit cooled relatively slowly and interstitial plagioclase present within this unit equilibrated with a trapped, more evolved liquid. The pyroxenite reef unit shows enrichment in incompatible elements and corresponding negative Eu anomalies, indicating the presence of trapped liquids. Cu, Ni and S concentrations remained low throughout the reef with the exception of a peak underlying the anorthositic seam and further enrichment underlying this peak. Platinum-group element geochemistry identified two major peaks: an upper peak which coincided with the peaks for Cu, Ni and S, and showed preferential enrichment in Pd and Au relative to other PGE, and a lower peak which coincided with the presence of chromitite and showed the preferential enrichment of Os, Ir, Ru, Rh and Pt relative to Pd, Au, Cu and Ni. The formation of the lower peak was consistent with a model involving the co-precipitation of chromite and PGE clusters (as PGM) while the upper peak was attributed to a model involving the collection of PGE by an immiscible sulphide liquid. Moreover, high Cu/Pd and Pt/Pd ratios in the lower pyroxenite unit indicated a process involving sulphide fractional segregation and scavenging while the inverse, present within the upper pyroxenite unit, suggested a more dynamic system involving the introduction of PGE-undepleted magma and S during simultaneous sulphide precipitation. Furthermore, a separation of PPGE peaks from IPGE peaks was observed within the pyroxenite unit, indicating a different partitioning behavior between PPGE and IPGE. The separation of these peaks is attributed to a sulphide liquid fractionation model while depletion haloes occurring in the proximity of the main PGE peaks was suggested to form through an Ostwald-ripening type mechanism. The results of this study are consistent with a model for the formation of the Merensky Reef involving a combination of geochemical processes, including sulphide segregation and fractionation, as well as multiple replenishments of magma.
- Full Text:
The use of treated brewery effluent as a water and nutrient source in crop irrigation
- Authors: Taylor, Richard Peter
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5390 , http://hdl.handle.net/10962/d1021265
- Description: Brewery effluent (BE) needs to be treated before it can be released into the environment, reused or used in down-stream activities. Current technologies used to address this concern at the experimental wastewater treatment plant at Ibahyi Brewery (SAB Ltd) include anaerobic digestion (AD), primary facultative ponds (PFP), high rate algal ponds (HRAP) and constructed wetlands (CW). The aim of this work was to determine if BE treated in these systems might be suitable for crop irrigation. A test crop, cabbage (Brassica oleracea cv. Star 3301), grew best on post-AD and post-PFP BE compared to those irrigated with post-HRAP or post-CW effluent. However, the yield was 13% lower than cabbage plants irrigated with a commercial nutrient solution and fresh water. The relatively high conductivity (3019.05 ± 48.72 μs/cm2) of BE may be the main factor reducing the cabbage yields. Post-HRAP and post-CW BE were the least suitable for irrigated crop production due to the higher conductivity and lower nutrient content of these treated effluents. After three months, soils irrigated with post-AD and post-PFP BE had a significantly higher sodium content and sodium adsorption ratio (3919 ± 94.77 mg/kg & 8.18 ± 0.17) than soil irrigated with a commercial nutrient solution (920.58 ± 27.46 mg/kg & 2.20 ± 0.05; p<0.05). However, this was not accompanied by a deterioration in the soil’s hydro-physical properties, nor a change in the metabolic community structure of the soil (p>0.05). After prolonged irrigation with treated BE, sodium is likely to build up in the soil and this can be expected to be accompanied by a deterioration in the soil physical structure. However, crops species such as millet (Echinochloa esculenta), lucerne (Medicago sativa) and saltbush (Atriplex nummularia) reduced the build-up of sodium in the soil. The results suggest that sodium was mainly removed from the soil through plant-assisted leaching. Of the crops grown, lucerne showed the most promise because it improved the soil physical properties, is able to grow well in alkaline environments, is a popular fodder crop and can be harvested multiple times from a single stand. Brewery effluent is more suitable for soil production systems than hydroponic production systems because the soil was able to act as a buffer against the high pH of post-AD BE, whereas in a hydroponics systems the high pH reduced the availability of key minerals to plants. In conclusion brewery effluent contains sufficient plants nutrients to support the growth of cabbages, saltbush, lucerne and millet. However the sodium content of BE is a concern as it accumulates in the soil, and in the long-term it may lead to soil degradation. It is suggested that the brewery change the pH neutralising treatment of BE from sodium hydroxide to potassium hydroxide, or dolomitic lime (calcium and magnesium carbonate) because this would reduce the introduction of sodium into the system, and would increase the suitability of BE for crop production, given potassium and calcium are plant nutrients. The benefits of developing this nutrient and water resource could contribute to cost-reductions at the brewery, more efficient water, nutrient and energy management, create job opportunities with the potential of improving food security in the local community.
- Full Text:
- Authors: Taylor, Richard Peter
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5390 , http://hdl.handle.net/10962/d1021265
- Description: Brewery effluent (BE) needs to be treated before it can be released into the environment, reused or used in down-stream activities. Current technologies used to address this concern at the experimental wastewater treatment plant at Ibahyi Brewery (SAB Ltd) include anaerobic digestion (AD), primary facultative ponds (PFP), high rate algal ponds (HRAP) and constructed wetlands (CW). The aim of this work was to determine if BE treated in these systems might be suitable for crop irrigation. A test crop, cabbage (Brassica oleracea cv. Star 3301), grew best on post-AD and post-PFP BE compared to those irrigated with post-HRAP or post-CW effluent. However, the yield was 13% lower than cabbage plants irrigated with a commercial nutrient solution and fresh water. The relatively high conductivity (3019.05 ± 48.72 μs/cm2) of BE may be the main factor reducing the cabbage yields. Post-HRAP and post-CW BE were the least suitable for irrigated crop production due to the higher conductivity and lower nutrient content of these treated effluents. After three months, soils irrigated with post-AD and post-PFP BE had a significantly higher sodium content and sodium adsorption ratio (3919 ± 94.77 mg/kg & 8.18 ± 0.17) than soil irrigated with a commercial nutrient solution (920.58 ± 27.46 mg/kg & 2.20 ± 0.05; p<0.05). However, this was not accompanied by a deterioration in the soil’s hydro-physical properties, nor a change in the metabolic community structure of the soil (p>0.05). After prolonged irrigation with treated BE, sodium is likely to build up in the soil and this can be expected to be accompanied by a deterioration in the soil physical structure. However, crops species such as millet (Echinochloa esculenta), lucerne (Medicago sativa) and saltbush (Atriplex nummularia) reduced the build-up of sodium in the soil. The results suggest that sodium was mainly removed from the soil through plant-assisted leaching. Of the crops grown, lucerne showed the most promise because it improved the soil physical properties, is able to grow well in alkaline environments, is a popular fodder crop and can be harvested multiple times from a single stand. Brewery effluent is more suitable for soil production systems than hydroponic production systems because the soil was able to act as a buffer against the high pH of post-AD BE, whereas in a hydroponics systems the high pH reduced the availability of key minerals to plants. In conclusion brewery effluent contains sufficient plants nutrients to support the growth of cabbages, saltbush, lucerne and millet. However the sodium content of BE is a concern as it accumulates in the soil, and in the long-term it may lead to soil degradation. It is suggested that the brewery change the pH neutralising treatment of BE from sodium hydroxide to potassium hydroxide, or dolomitic lime (calcium and magnesium carbonate) because this would reduce the introduction of sodium into the system, and would increase the suitability of BE for crop production, given potassium and calcium are plant nutrients. The benefits of developing this nutrient and water resource could contribute to cost-reductions at the brewery, more efficient water, nutrient and energy management, create job opportunities with the potential of improving food security in the local community.
- Full Text:
An investigation into the promotion of productive learning dispositions in government policies and teacher assessment in Grade R and Grade 1
- Authors: Long, Roxanne
- Date: 2015
- Subjects: Learning, Psychology of , Early childhood education -- Evaluation , Learning -- Evaluation , Educational psychology
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:2018 , http://hdl.handle.net/10962/d1017182
- Description: The impetus for this study came from the increasing acknowledgement of learning dispositions as a central, yet largely under explored area of numeracy learning, in both international education literature and in the current work conducted by the South African Numeracy Chair, based at Rhodes University. This coupled with my own personal interest in the crucial transitional phase between Grade R (the year before formal schooling) and Grade 1 and the role of developing progressively strengthened learning dispositions, particularly in relation to numeracy learning, to enable this transition. This, together with the lack of research around what constitutes a quality Grade R programme, especially in South Africa, inspired an investigation into the promotion of key productive learning dispositions within current government policy and in teacher assessment practices across Grade R and Grade 1 in six local schools. I designed a qualitative research study underpinned by a socio-cultural theoretical perspective that foregrounds learning. Within this broad theoretical perspective I drew on two key analytic frameworks that cohere with this socio cultural view that prioritises learning dispositions (ways of being, habits of mind). In particular the work of Kilpatrick et al. (2001) and Carr & Claxton (2010), in defining essential elements of key productive learning dispositions, were combined to enable the development of an indicator matrix used for the analysis of current government policy and teacher assessment practices in the Grade R and Grade 1. Additionally empirical data from the study enabled extension and adaptation of the indicator matrix derived from key literature. The research contributes an analysis of various curriculum and policy documents across Grade R and 1 in terms of the inclusion and promotion of learning dispositions. The presences of certain promoted dispositions are compared with international literature and frameworks and certain absences or under represented dispositions are noted. The empirical data derived from Gr R and Gr 1 teacher questionnaires and exemplar reports across 6 schools are analysed and related back to policy. Similarities and differences across teachers in different grades and teachers in different schools are discussed. The findings point towards several avenues of research and also provide an emergent dispositional discourse from empirical data, policy analysis and literature that could enable engagement between various stakeholders around the notion of learning dispositions as a central feature of schooling in the Grade R to Grade 1 transition. It is argued from the data that the inclusion of exemplar reports, in teacher assessment policy guides, which indicate possible ways to communicate dispositional priorities to both parents and learners, would assist teachers in achieving greater coherence between dispositions promoted in the classroom and those assessed and reported on.
- Full Text:
- Authors: Long, Roxanne
- Date: 2015
- Subjects: Learning, Psychology of , Early childhood education -- Evaluation , Learning -- Evaluation , Educational psychology
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:2018 , http://hdl.handle.net/10962/d1017182
- Description: The impetus for this study came from the increasing acknowledgement of learning dispositions as a central, yet largely under explored area of numeracy learning, in both international education literature and in the current work conducted by the South African Numeracy Chair, based at Rhodes University. This coupled with my own personal interest in the crucial transitional phase between Grade R (the year before formal schooling) and Grade 1 and the role of developing progressively strengthened learning dispositions, particularly in relation to numeracy learning, to enable this transition. This, together with the lack of research around what constitutes a quality Grade R programme, especially in South Africa, inspired an investigation into the promotion of key productive learning dispositions within current government policy and in teacher assessment practices across Grade R and Grade 1 in six local schools. I designed a qualitative research study underpinned by a socio-cultural theoretical perspective that foregrounds learning. Within this broad theoretical perspective I drew on two key analytic frameworks that cohere with this socio cultural view that prioritises learning dispositions (ways of being, habits of mind). In particular the work of Kilpatrick et al. (2001) and Carr & Claxton (2010), in defining essential elements of key productive learning dispositions, were combined to enable the development of an indicator matrix used for the analysis of current government policy and teacher assessment practices in the Grade R and Grade 1. Additionally empirical data from the study enabled extension and adaptation of the indicator matrix derived from key literature. The research contributes an analysis of various curriculum and policy documents across Grade R and 1 in terms of the inclusion and promotion of learning dispositions. The presences of certain promoted dispositions are compared with international literature and frameworks and certain absences or under represented dispositions are noted. The empirical data derived from Gr R and Gr 1 teacher questionnaires and exemplar reports across 6 schools are analysed and related back to policy. Similarities and differences across teachers in different grades and teachers in different schools are discussed. The findings point towards several avenues of research and also provide an emergent dispositional discourse from empirical data, policy analysis and literature that could enable engagement between various stakeholders around the notion of learning dispositions as a central feature of schooling in the Grade R to Grade 1 transition. It is argued from the data that the inclusion of exemplar reports, in teacher assessment policy guides, which indicate possible ways to communicate dispositional priorities to both parents and learners, would assist teachers in achieving greater coherence between dispositions promoted in the classroom and those assessed and reported on.
- Full Text:
Afro-communitarianism and the nature of reconciliation
- Authors: Oelofsen, Rianna
- Date: 2013
- Subjects: Ubuntu (Philosophy) Reconciliation -- South Africa Communitarianism -- Africa Philosophy, African
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2736 , http://hdl.handle.net/10962/d1006809
- Description: In this dissertation I sketch a conception of personhood as understood from within an Afrocommunitarian worldview, and argue that this understanding of personhood has implications for understanding the concept of reconciliation. Understanding ‘being human’ as a collective, communal enterprise has implications for how responsibility, justice, forgiveness and humanization (all cognate concepts of reconciliation) are conceptualized. In line with this understanding of reconciliation and its cognate concepts, I argue that the humanization of self and other (according to the Afrocommunitarian understanding of personhood) is required for addressing the ‘inferiority’ and concurrent ‘superiority’ racial complexes as diagnosed by Franz Fanon and Steve Biko. These complexes reach deeply within individual and collective psyches and political identities, and I argue that political solutions to protracted conflict (in South Africa and other racially charged contexts) which do not address these deeply entrenched pathologies will be inadequate according to an Afrocommunitarian framework.
- Full Text:
- Authors: Oelofsen, Rianna
- Date: 2013
- Subjects: Ubuntu (Philosophy) Reconciliation -- South Africa Communitarianism -- Africa Philosophy, African
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2736 , http://hdl.handle.net/10962/d1006809
- Description: In this dissertation I sketch a conception of personhood as understood from within an Afrocommunitarian worldview, and argue that this understanding of personhood has implications for understanding the concept of reconciliation. Understanding ‘being human’ as a collective, communal enterprise has implications for how responsibility, justice, forgiveness and humanization (all cognate concepts of reconciliation) are conceptualized. In line with this understanding of reconciliation and its cognate concepts, I argue that the humanization of self and other (according to the Afrocommunitarian understanding of personhood) is required for addressing the ‘inferiority’ and concurrent ‘superiority’ racial complexes as diagnosed by Franz Fanon and Steve Biko. These complexes reach deeply within individual and collective psyches and political identities, and I argue that political solutions to protracted conflict (in South Africa and other racially charged contexts) which do not address these deeply entrenched pathologies will be inadequate according to an Afrocommunitarian framework.
- Full Text:
Investigating the dual influences of theory and practice on the design and implementation of a learning programme
- Authors: Jackelman, Susan Iona
- Date: 2012
- Subjects: Education -- Research Education -- Philosophy Teaching -- Methodology -- South Africa -- Eastern Cape Mathematics teachers -- Training of -- South Africa -- Eastern Cape Teaching -- Aids and devices -- South Africa -- Eastern Cape Mathematics -- Study and teaching (Secondary) -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1591 , http://hdl.handle.net/10962/d1003473
- Description: It is widely recognized that educational research and theory should be motivated by the desire to continually improve the practice of teaching. However, bridging the divide between theoretical research outcomes and the practical constraints of classroom-based teaching has proved somewhat challenging. The involvement of teachers as the 'bridge-builders' between theory and practice could provide an effective mechanism for achieving this integration. The purpose of this study is thus to investigate whether the involvement of teachers in developing and implementing a theory-based teaching module would improve teaching practice in the classroom. A teaching module was collaboratively developed by a group of teachers for Grade 9 linear functions using: the principles of mathematical proficiency postulated by Kilpatrick, Swafford and Findell, (2001); the teaching phases formulated by van Hiele (1986); and the cognitive classification of classroom activities developed by Stein and Smith (1998). This module was then taught to six Grade 9 classes by four teachers in one school in the Eastern Cape, South Africa over a period of 5 weeks. The effectiveness of the module, and its application in the classroom, was assessed in terms of: (i) the extent to which theory could be used to inform the design and development of teaching materials; (ii) the efficacy of this teaching material in promoting teaching for mathematical proficiency; and (iii) the effects of extraneous influences on the usefulness of the module in teaching for mathematical proficiency. While the theoretical framework provided a sound basis for developing the teaching module, it was found that collaboratively transforming this theory into a teaching module for practical use in the classroom is certainly possible, but it requires considerable time and effort that practising teachers do not have. Developing the depth of understanding required for mathematical proficiency also takes time - a commodity often in short supply as teachers grapple with the demands of the curriculum. Teaching for mathematical proficiency is a layered process. It starts with thinking about an idea (like a graph) that is developed out of a related concept that then has a set of characteristic algorithms and actions which are learnt and performed in sequence. Building understanding in this way ends with a student being able to visualize and conceive the graph as a structure that can be described as if it were an object (encapsulating all the previous concepts belonging to similar graphs in one idea). This development of understanding is important for mathematical proficiency but is not necessarily easy. When teaching with the module, it was necessary to create an extra opportunity for students to use procedural knowledge and repetition in order to provide enough examples to help them see the link: between linear number patterns and linear graphs. Extraneous influences on teaching for mathematical proficiency were grouped into two categories - endogenous and exogenous influences. Endogenous influences were teacher related and included the attitudes, decisions and disposition of the teacher. Exogenous influences were more contextual (and in effect out of the control of the teacher) and included teaching time available, curriculum, external assessments etc. Both of these influences were seen to affect teaching for mathematical proficiency, either promoting or inhibiting it. This research affirmed the central role that teachers play in teaching for mathematical proficiency. It is considered critical that research actively involve teachers in the evolution of mathematical theory. The development of an enabling environment (including institutional support, time, capacity, resources, skills and tools) for teachers will further enhance their capacity to teach for mathematical proficiency.
- Full Text:
- Authors: Jackelman, Susan Iona
- Date: 2012
- Subjects: Education -- Research Education -- Philosophy Teaching -- Methodology -- South Africa -- Eastern Cape Mathematics teachers -- Training of -- South Africa -- Eastern Cape Teaching -- Aids and devices -- South Africa -- Eastern Cape Mathematics -- Study and teaching (Secondary) -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1591 , http://hdl.handle.net/10962/d1003473
- Description: It is widely recognized that educational research and theory should be motivated by the desire to continually improve the practice of teaching. However, bridging the divide between theoretical research outcomes and the practical constraints of classroom-based teaching has proved somewhat challenging. The involvement of teachers as the 'bridge-builders' between theory and practice could provide an effective mechanism for achieving this integration. The purpose of this study is thus to investigate whether the involvement of teachers in developing and implementing a theory-based teaching module would improve teaching practice in the classroom. A teaching module was collaboratively developed by a group of teachers for Grade 9 linear functions using: the principles of mathematical proficiency postulated by Kilpatrick, Swafford and Findell, (2001); the teaching phases formulated by van Hiele (1986); and the cognitive classification of classroom activities developed by Stein and Smith (1998). This module was then taught to six Grade 9 classes by four teachers in one school in the Eastern Cape, South Africa over a period of 5 weeks. The effectiveness of the module, and its application in the classroom, was assessed in terms of: (i) the extent to which theory could be used to inform the design and development of teaching materials; (ii) the efficacy of this teaching material in promoting teaching for mathematical proficiency; and (iii) the effects of extraneous influences on the usefulness of the module in teaching for mathematical proficiency. While the theoretical framework provided a sound basis for developing the teaching module, it was found that collaboratively transforming this theory into a teaching module for practical use in the classroom is certainly possible, but it requires considerable time and effort that practising teachers do not have. Developing the depth of understanding required for mathematical proficiency also takes time - a commodity often in short supply as teachers grapple with the demands of the curriculum. Teaching for mathematical proficiency is a layered process. It starts with thinking about an idea (like a graph) that is developed out of a related concept that then has a set of characteristic algorithms and actions which are learnt and performed in sequence. Building understanding in this way ends with a student being able to visualize and conceive the graph as a structure that can be described as if it were an object (encapsulating all the previous concepts belonging to similar graphs in one idea). This development of understanding is important for mathematical proficiency but is not necessarily easy. When teaching with the module, it was necessary to create an extra opportunity for students to use procedural knowledge and repetition in order to provide enough examples to help them see the link: between linear number patterns and linear graphs. Extraneous influences on teaching for mathematical proficiency were grouped into two categories - endogenous and exogenous influences. Endogenous influences were teacher related and included the attitudes, decisions and disposition of the teacher. Exogenous influences were more contextual (and in effect out of the control of the teacher) and included teaching time available, curriculum, external assessments etc. Both of these influences were seen to affect teaching for mathematical proficiency, either promoting or inhibiting it. This research affirmed the central role that teachers play in teaching for mathematical proficiency. It is considered critical that research actively involve teachers in the evolution of mathematical theory. The development of an enabling environment (including institutional support, time, capacity, resources, skills and tools) for teachers will further enhance their capacity to teach for mathematical proficiency.
- Full Text:
The druggable antimalarial target 1-deoxy-D-xylulose-5-phosphate reductoisomerase: purfication, kinetic characterization and inhibition studies
- Authors: Goble, Jessica Leigh
- Date: 2011
- Subjects: Antimalarials -- Development Plasmodium falciparum Drug development Plasmodium falciparum -- Purification Plasmodium falciparum -- Inhibitors Enzyme kinetics Malaria -- Chemotherapy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3949 , http://hdl.handle.net/10962/d1004008
- Description: Plasmodium falciparum 1–deoxy–D–xylulose–5 phosphatereductoisomerase (PfDXR) plays a role in isoprenoid biosynthesis in the malaria parasite and is absent in the human host, making this parasite enzyme an attractive target for antimalarial drug design. To characterize PfDXR, it is necessary to produce large quantities of the enzyme in a soluble and functional form. However, the over–production of malarial proteins in prokaryotic host systems often results in the formation of truncated proteins or insoluble protein aggregates. A heterologous expression system was developed for the production of active PfDXR using codon harmonization and tight control of expression in the presence of lac repressor. Yields of up to 2 mg/l of enzyme were reported using the optimised expression system, which is 8 to 10– fold greater than previously reported yields. The kinetic parameters Km, Vmax and kcat were determined for PfDXR; values reported in this study were consistent with those reported in the literature for other DXR enzymes. A three–dimensional model of the malarial drug target protein PfDXR was generated, and validated using structure–checking programs and protein docking studies. Structural and functional features unique to PfDXR were identified using the model and comparative sequence analyses with apicomplexan and non–apicomplexan DXR proteins. Residues Val44 and Asn45, essential for NADPH binding; and catalytic hatch residues Lys224 and Lys226, which are unique to the species of Plasmodium, were mutated to resemble those of E. coli DXR. Interestingly,these mutations resulted in significant reductions in substrate affinity, when compared to the unmutated PfDXR. Mutant enzymes PfDXR(VN43,44AG) and PfDXR(KK224,226NS) also demonstrated a decreased ability to turnover substrate by 4–fold and 2–fold respectively. This study indicates a difference in the role of the catalytic hatch of PfDXR with regards to the way in which it captures substrates. The study also highlights subtle differences in cofactor binding to PfDXR, compared with the well characterized EcDXR enzyme. The validated PfDXR model was also used to develop a novel efficient in silico screening method for potential tool compounds for use in the rational design of novel DXR inhibitors. Following in silico screening of 46 potential DXR inhibitors, a two–tiered in vitro screening approach was undertaken. DXR inhibition was assessed for the 46 novel compounds using an NADPH– ependant DXP enzyme inhibition assay and antimalarial potential was assessed using P.falciparum–infected erythrocyte growth assays. Select compounds were tested in human cells in order to determine whether they were toxic to the host. From the parallel in silico and in vitro drug screening, it was evident that only a single compound demonstrated reasonable potential binding to DXR (determined using in silico docking), inhibited DXR in vitro and inhibited P. falciparum growth, without being toxic to human cells. Its potential as a lead compound in antimalarial drug development is therefore feasible. Two outcomes were evident from this work. Firstly, analogues of known antimalarial natural products can be screened against malaria, which may then lead towards the rational design of novel compounds that are effective against a specific antimalarial drug target enzyme, such as PfDXR. Secondly, the rational design of novel compounds against a specific antimalarial drug target enzyme can be untaken by adopting a coupled in silico and in vitro approach to drug discovery.
- Full Text:
- Authors: Goble, Jessica Leigh
- Date: 2011
- Subjects: Antimalarials -- Development Plasmodium falciparum Drug development Plasmodium falciparum -- Purification Plasmodium falciparum -- Inhibitors Enzyme kinetics Malaria -- Chemotherapy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3949 , http://hdl.handle.net/10962/d1004008
- Description: Plasmodium falciparum 1–deoxy–D–xylulose–5 phosphatereductoisomerase (PfDXR) plays a role in isoprenoid biosynthesis in the malaria parasite and is absent in the human host, making this parasite enzyme an attractive target for antimalarial drug design. To characterize PfDXR, it is necessary to produce large quantities of the enzyme in a soluble and functional form. However, the over–production of malarial proteins in prokaryotic host systems often results in the formation of truncated proteins or insoluble protein aggregates. A heterologous expression system was developed for the production of active PfDXR using codon harmonization and tight control of expression in the presence of lac repressor. Yields of up to 2 mg/l of enzyme were reported using the optimised expression system, which is 8 to 10– fold greater than previously reported yields. The kinetic parameters Km, Vmax and kcat were determined for PfDXR; values reported in this study were consistent with those reported in the literature for other DXR enzymes. A three–dimensional model of the malarial drug target protein PfDXR was generated, and validated using structure–checking programs and protein docking studies. Structural and functional features unique to PfDXR were identified using the model and comparative sequence analyses with apicomplexan and non–apicomplexan DXR proteins. Residues Val44 and Asn45, essential for NADPH binding; and catalytic hatch residues Lys224 and Lys226, which are unique to the species of Plasmodium, were mutated to resemble those of E. coli DXR. Interestingly,these mutations resulted in significant reductions in substrate affinity, when compared to the unmutated PfDXR. Mutant enzymes PfDXR(VN43,44AG) and PfDXR(KK224,226NS) also demonstrated a decreased ability to turnover substrate by 4–fold and 2–fold respectively. This study indicates a difference in the role of the catalytic hatch of PfDXR with regards to the way in which it captures substrates. The study also highlights subtle differences in cofactor binding to PfDXR, compared with the well characterized EcDXR enzyme. The validated PfDXR model was also used to develop a novel efficient in silico screening method for potential tool compounds for use in the rational design of novel DXR inhibitors. Following in silico screening of 46 potential DXR inhibitors, a two–tiered in vitro screening approach was undertaken. DXR inhibition was assessed for the 46 novel compounds using an NADPH– ependant DXP enzyme inhibition assay and antimalarial potential was assessed using P.falciparum–infected erythrocyte growth assays. Select compounds were tested in human cells in order to determine whether they were toxic to the host. From the parallel in silico and in vitro drug screening, it was evident that only a single compound demonstrated reasonable potential binding to DXR (determined using in silico docking), inhibited DXR in vitro and inhibited P. falciparum growth, without being toxic to human cells. Its potential as a lead compound in antimalarial drug development is therefore feasible. Two outcomes were evident from this work. Firstly, analogues of known antimalarial natural products can be screened against malaria, which may then lead towards the rational design of novel compounds that are effective against a specific antimalarial drug target enzyme, such as PfDXR. Secondly, the rational design of novel compounds against a specific antimalarial drug target enzyme can be untaken by adopting a coupled in silico and in vitro approach to drug discovery.
- Full Text:
Application of dermal microdialysis and tape stripping methods to determine the bioavailability and/or bioequivalence of topical ketoprofen formulations
- Tettey-Amlalo, Ralph Nii Okai
- Authors: Tettey-Amlalo, Ralph Nii Okai
- Date: 2008
- Subjects: Drugs -- Therapeutic equivalency Transdermal medication High performance liquid chromatography Nonsteroidal anti-inflammatory agents -- Bioavailability Nonsteroidal anti-inflammatory agents -- Effectiveness Nonsteroidal anti-inflammatory agents -- Testing Nonsteroidal anti-inflammatory agents -- Side effects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3796 , http://hdl.handle.net/10962/d1003274
- Description: The widespread acceptance of topical formulations intended for local and/or regional activity has prompted renewed interest in developing a model to determine the bioavailability of drugs in order to establish bioequivalence as a means of evaluating formulation performance of multisource products and also for use during formulation development. Current in vivo techniques such as blister suction and skin biopsy amongst others used to determine the bioavailability and/or bioequivalence of topical formulations are either too invasive to generate appropriate concentration-time profiles or require large numbers of study subjects thereby making the study expensive and time-consuming. Moreover, there are currently no sampling techniques that can demonstrate dermal bioavailability and/or bioequivalence of topical formulations intended for local and/or regional activity. Dermal microdialysis is a relatively new application of microdialysis that permits continuous monitoring of endogenous and/or exogenous solutes in the interstitial fluid. The technique is involves the implantation of semi-permeable membranes which are perfused with an isotonic medium at extremely slow flow rates and collection of microlitre sample volumes containing diffused drugs. Tape stripping, a relatively older technique, has been extensively used in comparative bioavailability studies of various topical formulations. However, due to shortcomings arising from reproducibility and inter-subject variation amongst others, the published FDA guidance outlining the initial protocol was subsequently withdrawn. The incorporation of transepidermal water loss with tape stripping has garnered renewed interest and has been used for the determination of drug bioavailability from a number of topical formulations. Hence the primary objective of this research is to develop and evaluate microdialysis sampling and tape stripping techniques, including the incorporation of the determination of transepidermal water loss, to assess the dermal bioavailability of ketoprofen from topical gel formulations and to develop models for bioequivalence assessment. A rapid UPLC-MS/MS method with requisite sensitivity for the analysis of samples generated from dermal microdialysis was developed and validated which accommodated the microlitre sample volumes collected. An HPLC-UV method was developed and validated for the analysis of samples generated from the in vitro microdialysis and in vivo tape stripping studies. The work presented herein contributes to a growing body of scientific knowledge seeking to develop a model for the determination of bioequivalence of pharmaceutically equivalent topical formulations intended for local and/or regional activity in human subjects.
- Full Text:
- Authors: Tettey-Amlalo, Ralph Nii Okai
- Date: 2008
- Subjects: Drugs -- Therapeutic equivalency Transdermal medication High performance liquid chromatography Nonsteroidal anti-inflammatory agents -- Bioavailability Nonsteroidal anti-inflammatory agents -- Effectiveness Nonsteroidal anti-inflammatory agents -- Testing Nonsteroidal anti-inflammatory agents -- Side effects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3796 , http://hdl.handle.net/10962/d1003274
- Description: The widespread acceptance of topical formulations intended for local and/or regional activity has prompted renewed interest in developing a model to determine the bioavailability of drugs in order to establish bioequivalence as a means of evaluating formulation performance of multisource products and also for use during formulation development. Current in vivo techniques such as blister suction and skin biopsy amongst others used to determine the bioavailability and/or bioequivalence of topical formulations are either too invasive to generate appropriate concentration-time profiles or require large numbers of study subjects thereby making the study expensive and time-consuming. Moreover, there are currently no sampling techniques that can demonstrate dermal bioavailability and/or bioequivalence of topical formulations intended for local and/or regional activity. Dermal microdialysis is a relatively new application of microdialysis that permits continuous monitoring of endogenous and/or exogenous solutes in the interstitial fluid. The technique is involves the implantation of semi-permeable membranes which are perfused with an isotonic medium at extremely slow flow rates and collection of microlitre sample volumes containing diffused drugs. Tape stripping, a relatively older technique, has been extensively used in comparative bioavailability studies of various topical formulations. However, due to shortcomings arising from reproducibility and inter-subject variation amongst others, the published FDA guidance outlining the initial protocol was subsequently withdrawn. The incorporation of transepidermal water loss with tape stripping has garnered renewed interest and has been used for the determination of drug bioavailability from a number of topical formulations. Hence the primary objective of this research is to develop and evaluate microdialysis sampling and tape stripping techniques, including the incorporation of the determination of transepidermal water loss, to assess the dermal bioavailability of ketoprofen from topical gel formulations and to develop models for bioequivalence assessment. A rapid UPLC-MS/MS method with requisite sensitivity for the analysis of samples generated from dermal microdialysis was developed and validated which accommodated the microlitre sample volumes collected. An HPLC-UV method was developed and validated for the analysis of samples generated from the in vitro microdialysis and in vivo tape stripping studies. The work presented herein contributes to a growing body of scientific knowledge seeking to develop a model for the determination of bioequivalence of pharmaceutically equivalent topical formulations intended for local and/or regional activity in human subjects.
- Full Text:
The cost of credit in the micro-finance industry in South Africa
- Authors: Campbell, Jonathan
- Date: 2007
- Subjects: Contracts -- South Africa , Credit -- Law and legislation -- South Africa , Microfinance -- South Africa , Usury laws -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3667 , http://hdl.handle.net/10962/d1003182 , Contracts -- South Africa , Credit -- Law and legislation -- South Africa , Microfinance -- South Africa , Usury laws -- South Africa
- Description: This thesis analyses the cost of credit in the micro-finance industry in South Africa. The study situates micro-lending agreements within the law of contract, beginning with an examination of contractual fairness in terms of the common law: the fundamental principle of freedom of contract that underpins the common law of contract; the principle that agreements contrary to public policy should not be enforced; and the impetus given by constitutional values that inform public policy. In regard to moneylending transactions, common law usury law will be explained. The study then goes on to trace the origins and rapid growth of the micro-finance industry which was made possible by its exemption in 1992 from the Usury Act 73 of 1968. The upshot of this development was that registered micro-lenders have for nearly 14 years charged excessive interest rates, and continue to do so. The dire socio-economic impact of these high interest rates on individual consumers and lowincome communities is then demonstrated: how borrowers of small loans soon become over-indebted; the loss of billions of rands every year to low-income communities in the form of interest on micro-loans. The study then shifts to the legislative response to the need for consumer protection in regard to consumer credit. The extensive credit law review process is explained, resulting ultimately in the National Credit Act 34 of 2005, which allows the Minister to prescribe limits on interest rates and fees in all sectors of the consumer credit market. The prescribed limits on the cost of credit in the micro-finance sector are thoroughly explained and analysed, with particular reference to the implications of each element of the credit costing structure, and the combined impact of the total cost of credit on different types and sizes of loans. The envisaged maximum interest and fees will markedly alter the positions of micro-lenders and consumers, and receive careful analysis. The study closes with a summary of findings in the thesis, which includes suggested amendments to the National Credit Regulations and a review of possible legal challenges to the high cost of credit on smaller loans.
- Full Text:
- Authors: Campbell, Jonathan
- Date: 2007
- Subjects: Contracts -- South Africa , Credit -- Law and legislation -- South Africa , Microfinance -- South Africa , Usury laws -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3667 , http://hdl.handle.net/10962/d1003182 , Contracts -- South Africa , Credit -- Law and legislation -- South Africa , Microfinance -- South Africa , Usury laws -- South Africa
- Description: This thesis analyses the cost of credit in the micro-finance industry in South Africa. The study situates micro-lending agreements within the law of contract, beginning with an examination of contractual fairness in terms of the common law: the fundamental principle of freedom of contract that underpins the common law of contract; the principle that agreements contrary to public policy should not be enforced; and the impetus given by constitutional values that inform public policy. In regard to moneylending transactions, common law usury law will be explained. The study then goes on to trace the origins and rapid growth of the micro-finance industry which was made possible by its exemption in 1992 from the Usury Act 73 of 1968. The upshot of this development was that registered micro-lenders have for nearly 14 years charged excessive interest rates, and continue to do so. The dire socio-economic impact of these high interest rates on individual consumers and lowincome communities is then demonstrated: how borrowers of small loans soon become over-indebted; the loss of billions of rands every year to low-income communities in the form of interest on micro-loans. The study then shifts to the legislative response to the need for consumer protection in regard to consumer credit. The extensive credit law review process is explained, resulting ultimately in the National Credit Act 34 of 2005, which allows the Minister to prescribe limits on interest rates and fees in all sectors of the consumer credit market. The prescribed limits on the cost of credit in the micro-finance sector are thoroughly explained and analysed, with particular reference to the implications of each element of the credit costing structure, and the combined impact of the total cost of credit on different types and sizes of loans. The envisaged maximum interest and fees will markedly alter the positions of micro-lenders and consumers, and receive careful analysis. The study closes with a summary of findings in the thesis, which includes suggested amendments to the National Credit Regulations and a review of possible legal challenges to the high cost of credit on smaller loans.
- Full Text:
The application of the monthly time step Pitman rainfall-runoff model to the Kafue River basin of Zambia
- Mwelwa, Elenestina Mutekenya
- Authors: Mwelwa, Elenestina Mutekenya
- Date: 2005
- Subjects: Kafue River (Zambia) , Kafue Flats (Zambia) , Floodplains -- Zambia , Rain and rainfall -- Mathematical models , Runoff -- Mathematical models , Hydrology -- Mathematical models
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:6032 , http://hdl.handle.net/10962/d1006171 , Kafue River (Zambia) , Kafue Flats (Zambia) , Floodplains -- Zambia , Rain and rainfall -- Mathematical models , Runoff -- Mathematical models , Hydrology -- Mathematical models
- Description: This thesis presents a discussion on the study undertaken in the application of the monthly time step Pitman rainfall-runoff model to the Kafue River basin. The study constituted one of the initial steps in the capacity building and expansion of the application of hydrologic models in the southern African region for water resources assessment, one of the core areas of the Southern African FRIEND project (Flow Regimes from International Experimental Network Data). The research process was undertaken in four major stages, each stage working towards achieving the research objectives. The first stage was the preparation of spatial data which included the selection and delineation of sub-catchments and inclusion of spatial features required to run the Pitman model and transferring the spatial data into SPATSIM. The second stage was the preparation of input data, mainly rainfall, streamflow, evaporation, and water abstraction data. This information was then imported into SPATSIM, which was able to assist in the further preparation of data by assessment of the input data quality, linking of observed flows and spatial interpolation of point rainfall data to average catchment rainfall in readiness for running and calibration of the model. The third stage was the running and calibration of the Pitman model. Use was made of both the automatic calibration facility, as well as manual calibration by means of the time series graph display and analysis facility of SPATSIM. Model calibration was used to obtain the best fit and an acceptable correlation between the simulated and the observed flows and to obtain simulation parameter sets for sub-catchments and regions within the Kafue catchment. The fourth stage was the analysis and evaluation of the model results. This included verification of results over different time periods and validation and testing of parameter transfers to other catchments. This stage also included the evaluation of SPATSIM as a tool for applying the model and as a database for the processing and storage of water resources data. The study’s output includes: A comprehensive database of hydrometeorological, physical catchment characteristics, landuse and water abstraction information for the Kafue basin; calibrated Pitman model parameters for the sub-catchments within the Kafue basin; recommendations for future work and data collection programmes for the application of the model. The study has also built capacity by facilitating training and exposure to rainfall-runoff models (specifically the Pitman model) and associated software, SPATSIM. In addition, the dissemination of the results of this study will serve as an effective way of raising awareness on the application of the Pitman model and the use of the SPATSIM software within Zambia and the region. The overall Pitman model results were found to be satisfactory and the calibrated model is able to reproduce the observed spatial and temporal variations in streamflow characteristics in the Kafue River basin.
- Full Text:
- Authors: Mwelwa, Elenestina Mutekenya
- Date: 2005
- Subjects: Kafue River (Zambia) , Kafue Flats (Zambia) , Floodplains -- Zambia , Rain and rainfall -- Mathematical models , Runoff -- Mathematical models , Hydrology -- Mathematical models
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:6032 , http://hdl.handle.net/10962/d1006171 , Kafue River (Zambia) , Kafue Flats (Zambia) , Floodplains -- Zambia , Rain and rainfall -- Mathematical models , Runoff -- Mathematical models , Hydrology -- Mathematical models
- Description: This thesis presents a discussion on the study undertaken in the application of the monthly time step Pitman rainfall-runoff model to the Kafue River basin. The study constituted one of the initial steps in the capacity building and expansion of the application of hydrologic models in the southern African region for water resources assessment, one of the core areas of the Southern African FRIEND project (Flow Regimes from International Experimental Network Data). The research process was undertaken in four major stages, each stage working towards achieving the research objectives. The first stage was the preparation of spatial data which included the selection and delineation of sub-catchments and inclusion of spatial features required to run the Pitman model and transferring the spatial data into SPATSIM. The second stage was the preparation of input data, mainly rainfall, streamflow, evaporation, and water abstraction data. This information was then imported into SPATSIM, which was able to assist in the further preparation of data by assessment of the input data quality, linking of observed flows and spatial interpolation of point rainfall data to average catchment rainfall in readiness for running and calibration of the model. The third stage was the running and calibration of the Pitman model. Use was made of both the automatic calibration facility, as well as manual calibration by means of the time series graph display and analysis facility of SPATSIM. Model calibration was used to obtain the best fit and an acceptable correlation between the simulated and the observed flows and to obtain simulation parameter sets for sub-catchments and regions within the Kafue catchment. The fourth stage was the analysis and evaluation of the model results. This included verification of results over different time periods and validation and testing of parameter transfers to other catchments. This stage also included the evaluation of SPATSIM as a tool for applying the model and as a database for the processing and storage of water resources data. The study’s output includes: A comprehensive database of hydrometeorological, physical catchment characteristics, landuse and water abstraction information for the Kafue basin; calibrated Pitman model parameters for the sub-catchments within the Kafue basin; recommendations for future work and data collection programmes for the application of the model. The study has also built capacity by facilitating training and exposure to rainfall-runoff models (specifically the Pitman model) and associated software, SPATSIM. In addition, the dissemination of the results of this study will serve as an effective way of raising awareness on the application of the Pitman model and the use of the SPATSIM software within Zambia and the region. The overall Pitman model results were found to be satisfactory and the calibrated model is able to reproduce the observed spatial and temporal variations in streamflow characteristics in the Kafue River basin.
- Full Text:
Development of a language policy in a rural school
- Authors: Fumba, Zamumzi Norman
- Date: 2003
- Subjects: Language policy -- South Africa Language and education -- South Africa Education, Rural -- South Africa -- Peddie Black people -- Education -- South Africa Native language and education -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1940 , http://hdl.handle.net/10962/d1007798
- Description: The study was undertaken to observe and participate in the process and development of a language policy for a rural secondary school in Peddie in the Eastern Cape. This was done in collaboration with parents, learners, and teachers. The researcher acted as a researcher, facilitator and learner in the process that Iead to the final product. Twenty four learners were selected from Grade 8 to Grade 10. These learners formed three focus groups. A questionnaire and lesson observation were used to establish what was taking place in the school with regard to language practices and preferences by learners, teachers and parents. Lesson observations were recorded by a tape recorder. Outcomes are that Xhosa is the dominant language to which the learners are exposed. They only have the exposure to 'chunks' of English in class and when they read magazines, newspapers and listening to radio and TV. Teachers code switch. This is supported by both learners and their parents. Parents want their children to improve performance by being taught in the medium of a language they understand well enough. The study shows different perceptions about the language that should be used as LOLT. Parents in the study favour English as LOLT, while parents in general favour Xhosa. This view is also held by both teachers and learners. At a conscious level when teachers and learners talk about the language to be used as LOLT, they favour English, but when they are faced with the reality of the class they are ambivalent, hence they code switch. The study finally reports on the divergent views of the parents, on one hand, and those of the teachers and the learners on the other hand. The divergence will be resolved in a workshop, part of the broader process of school language policy research, which is beyond the scope of the research reported in the thesis. The final product, in the form of the school language policy, will then be drafted for presentation to the School Governing Body (SGB) for ratification and writing up process.
- Full Text:
- Authors: Fumba, Zamumzi Norman
- Date: 2003
- Subjects: Language policy -- South Africa Language and education -- South Africa Education, Rural -- South Africa -- Peddie Black people -- Education -- South Africa Native language and education -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1940 , http://hdl.handle.net/10962/d1007798
- Description: The study was undertaken to observe and participate in the process and development of a language policy for a rural secondary school in Peddie in the Eastern Cape. This was done in collaboration with parents, learners, and teachers. The researcher acted as a researcher, facilitator and learner in the process that Iead to the final product. Twenty four learners were selected from Grade 8 to Grade 10. These learners formed three focus groups. A questionnaire and lesson observation were used to establish what was taking place in the school with regard to language practices and preferences by learners, teachers and parents. Lesson observations were recorded by a tape recorder. Outcomes are that Xhosa is the dominant language to which the learners are exposed. They only have the exposure to 'chunks' of English in class and when they read magazines, newspapers and listening to radio and TV. Teachers code switch. This is supported by both learners and their parents. Parents want their children to improve performance by being taught in the medium of a language they understand well enough. The study shows different perceptions about the language that should be used as LOLT. Parents in the study favour English as LOLT, while parents in general favour Xhosa. This view is also held by both teachers and learners. At a conscious level when teachers and learners talk about the language to be used as LOLT, they favour English, but when they are faced with the reality of the class they are ambivalent, hence they code switch. The study finally reports on the divergent views of the parents, on one hand, and those of the teachers and the learners on the other hand. The divergence will be resolved in a workshop, part of the broader process of school language policy research, which is beyond the scope of the research reported in the thesis. The final product, in the form of the school language policy, will then be drafted for presentation to the School Governing Body (SGB) for ratification and writing up process.
- Full Text:
Effects of substituents on the photosensitizing and electrocatalytic properties of phthalocyanines
- Authors: Maree, Suzanne Elizabeth
- Date: 2002
- Subjects: Phthalocyanines
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4554 , http://hdl.handle.net/10962/d1018247
- Description: In this work a selection of octasubstituted phthalocyaninato Zinc, Ge(IV) and Sn(IV) complexes were synthesized for possible use in photodynamic therapy and their photochemistry, photophysics and electrochemistry studied. Third-generation complexes containing steroids, e.g. cholesterol and estrone, were synthesized to improve tumour selectivity. The zinc phthalocyanine complexes (ZnPc) showed that complexes containing electron-donating groups have higher photostability. Germanium phthalocyanine complexes (GePc) undergo phototransformation rather than direct photobleaching and the tin phthalocyanine complexes (SnPc) undergo photobleaching mediated by photoreduction of the phthalocyanine ring. Singlet oxygen production showed increased in the following order: GePc>SnPc>ZnPc. Triplet lifetimes of the GePc (168-340μs) are very similar to that of the ZnPc (197 - 366μs), but the triplet lifetimes of the SnPc are ten fold shorter (10 - 32μs ). Triplet quantum yields are higher for the GePc (0.20 - 0.50) and SnPc (0.08 - 0.45) than for the ZnPc (0.02 - 0.25). Fluorescence lifetimes of GePc ( 4.0 - 5.1 ns) are significantly longer than that of ZnPc (1.9 - 3.0 ns) and SnPc (0.2 - 0.4 ns). Fluorescence quantum yields decrease in the following order: GePc(0.21-0.31)>ZnPc(0.02-0.21)>SnPc(0.02- 0.06). Ring-substituted cobalt phthalocyanine complexes of the form CoPc(R)4 (R= NH2, N02, C(CH3)3, S03H and COOH) are compared for their catalytic activities towards the oxidation of cysteine. The potential for the electrocatalytic oxidation of cysteine is closely related to the Com/Co11 couple of the CoPc(R)4 complexes in acidic media and to the Con/Co1 couple in basic media. The catalytic current and the oxidation potential for cysteine are dependent on the pH of the solution, the potential becoming less positive and the currents increasing with increase in pH.
- Full Text:
- Authors: Maree, Suzanne Elizabeth
- Date: 2002
- Subjects: Phthalocyanines
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4554 , http://hdl.handle.net/10962/d1018247
- Description: In this work a selection of octasubstituted phthalocyaninato Zinc, Ge(IV) and Sn(IV) complexes were synthesized for possible use in photodynamic therapy and their photochemistry, photophysics and electrochemistry studied. Third-generation complexes containing steroids, e.g. cholesterol and estrone, were synthesized to improve tumour selectivity. The zinc phthalocyanine complexes (ZnPc) showed that complexes containing electron-donating groups have higher photostability. Germanium phthalocyanine complexes (GePc) undergo phototransformation rather than direct photobleaching and the tin phthalocyanine complexes (SnPc) undergo photobleaching mediated by photoreduction of the phthalocyanine ring. Singlet oxygen production showed increased in the following order: GePc>SnPc>ZnPc. Triplet lifetimes of the GePc (168-340μs) are very similar to that of the ZnPc (197 - 366μs), but the triplet lifetimes of the SnPc are ten fold shorter (10 - 32μs ). Triplet quantum yields are higher for the GePc (0.20 - 0.50) and SnPc (0.08 - 0.45) than for the ZnPc (0.02 - 0.25). Fluorescence lifetimes of GePc ( 4.0 - 5.1 ns) are significantly longer than that of ZnPc (1.9 - 3.0 ns) and SnPc (0.2 - 0.4 ns). Fluorescence quantum yields decrease in the following order: GePc(0.21-0.31)>ZnPc(0.02-0.21)>SnPc(0.02- 0.06). Ring-substituted cobalt phthalocyanine complexes of the form CoPc(R)4 (R= NH2, N02, C(CH3)3, S03H and COOH) are compared for their catalytic activities towards the oxidation of cysteine. The potential for the electrocatalytic oxidation of cysteine is closely related to the Com/Co11 couple of the CoPc(R)4 complexes in acidic media and to the Con/Co1 couple in basic media. The catalytic current and the oxidation potential for cysteine are dependent on the pH of the solution, the potential becoming less positive and the currents increasing with increase in pH.
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A case study of input and classroom interaction in a multilingual chemistry class at the Port Elizabeth Technikon
- Authors: Potgieter, Sally
- Date: 1996
- Subjects: Interaction analysis in education Teacher-student relationships Language and languages -- Study and teaching Multicultural education -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1437 , http://hdl.handle.net/10962/d1003318
- Description: This study examines input and interactional modifications in a multilingual chemistry class at the Port Elizabeth Technikon. The investigation constituted observing lectures presented in chemistry and analysing the data so obtained within a framework developed from a study of current theories on the relationship between language and cognition and the role of input. It was further informed by data gathered from interviews with the lecturer, questionnaires administered to the students and separate focus group discussions with first language and second language speakers of English. The conclusion is that the lecturer's interactional and input modifications make the subject content accessible to both first language and second language learners. I have made suggestions for future research in this area in the belief that the data gathered in this case study offers some useful pointers for the retraining of teachers of multilingual classes in a tertiary context.
- Full Text:
- Authors: Potgieter, Sally
- Date: 1996
- Subjects: Interaction analysis in education Teacher-student relationships Language and languages -- Study and teaching Multicultural education -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1437 , http://hdl.handle.net/10962/d1003318
- Description: This study examines input and interactional modifications in a multilingual chemistry class at the Port Elizabeth Technikon. The investigation constituted observing lectures presented in chemistry and analysing the data so obtained within a framework developed from a study of current theories on the relationship between language and cognition and the role of input. It was further informed by data gathered from interviews with the lecturer, questionnaires administered to the students and separate focus group discussions with first language and second language speakers of English. The conclusion is that the lecturer's interactional and input modifications make the subject content accessible to both first language and second language learners. I have made suggestions for future research in this area in the belief that the data gathered in this case study offers some useful pointers for the retraining of teachers of multilingual classes in a tertiary context.
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Where are the men? : an investigation into female-headed households in Rini, with reference to household structures, the dynamics of gender and strategies against poverty
- Authors: Brown, Brenda
- Date: 1996
- Subjects: Women heads of households -- South Africa , Poor women -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2097 , http://hdl.handle.net/10962/d1002660 , Women heads of households -- South Africa , Poor women -- South Africa
- Description: An in-depth study is conducted into ten female-headed households in the township of Rini, an underprivileged section of Grahamstown in the Eastem Cape region of South Africa. The study provides information on the way in which such households function in conditions of poverty and underemployment. The meaning of the term 'household' is clearly defined. A household consists of a group of people, who may or may not be kin-related, but who usually live under the same roof, eat together and share resources. Household members may be absent for varying periods of time, but are still considered to have rights in the household to which they belong. The female-headed household usually contains a core of adult women who are often uterine kin. Men are frequently members of these households and are usually related to the women who form the core. Their status and roles in such households are defined and intra-household relations between household members are discussed. In this study, female headship is observed to occur in conditions of poverty when an elderly woman is widowed, receives a regular income in the form of and old age pension, and when her status as the senior member of the household is acknowledged. The presence of men in female-headed households has not been widely emphasised in other studies, either of the female-headed household itself, or in research done in this area of South Africa. An attempt is therefore made to illustrate the way in which men function in these households and the varying roles they play. An attempt is also made to describe other structures and practices which support the female-headed household in a rapidly changing urban environment. These include church membership, burial society membership, the informal economy, wider kinship networks and, in the case of the men, the rite of circumcision.
- Full Text:
- Authors: Brown, Brenda
- Date: 1996
- Subjects: Women heads of households -- South Africa , Poor women -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2097 , http://hdl.handle.net/10962/d1002660 , Women heads of households -- South Africa , Poor women -- South Africa
- Description: An in-depth study is conducted into ten female-headed households in the township of Rini, an underprivileged section of Grahamstown in the Eastem Cape region of South Africa. The study provides information on the way in which such households function in conditions of poverty and underemployment. The meaning of the term 'household' is clearly defined. A household consists of a group of people, who may or may not be kin-related, but who usually live under the same roof, eat together and share resources. Household members may be absent for varying periods of time, but are still considered to have rights in the household to which they belong. The female-headed household usually contains a core of adult women who are often uterine kin. Men are frequently members of these households and are usually related to the women who form the core. Their status and roles in such households are defined and intra-household relations between household members are discussed. In this study, female headship is observed to occur in conditions of poverty when an elderly woman is widowed, receives a regular income in the form of and old age pension, and when her status as the senior member of the household is acknowledged. The presence of men in female-headed households has not been widely emphasised in other studies, either of the female-headed household itself, or in research done in this area of South Africa. An attempt is therefore made to illustrate the way in which men function in these households and the varying roles they play. An attempt is also made to describe other structures and practices which support the female-headed household in a rapidly changing urban environment. These include church membership, burial society membership, the informal economy, wider kinship networks and, in the case of the men, the rite of circumcision.
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The evolution of heteronomous host relationships in Aphelinidaa (Hymenoptera Chalcidoidea) with special reference to the biology of Coccophagus Bartletti Annecke and Insley
- Authors: Walter, Grenville Hugh
- Date: 1984
- Subjects: Hymenoptera
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5620 , http://hdl.handle.net/10962/d1003746
- Description: Résumé: Heteronomous host relationships are unique to parasitoids in about 8 aphelinid genera. Males have host relationships quite distinct from those of their females. Females of ALL species are primary endoparasitoids of homopterous hosts. Males, on the other hand, may be either primary ectoparasitoids of the same host species as their conspecific females, or they may be hyperparasitic upon parasitoids within Homoptera, and some are primary endoparasitoids of moth eggs. Species in these groups are termed DIPHAGOUS PARASITOIDS, HETERONOMOUS HYPERPARASITOIDS and HETEROTROPHIC PARASITOIDS, respectively. The selective advantages proposed to explain the evolution of these unusual host relationships are examined in this thesis. The biology of a diphagous parasitoid was examined in detail because diphagous parasitism is considered the most primitive of heteronomous host relationships. Diphagous parasitism is thought to have evolved during a period when ovipositing females continuously encountered large proportions of parasitised hosts. Larval competition may have generated the selection pressures that favoured male ectoparasitism. Ectoparasitoids are known to be superior in competition against other larvae, even older ones. A series of observations was carried out on the diphagous parasitoid, Coccophagus bartletti. Information was gathered on oviposition and host-feeding behaviour, daily activity patterns, and sex ratios in the laboratory and field. This enabled the design and interpretation of a series of observations on the responses of mated C. bartletti females to already-parasitised hosts. The results indicate that competition from other parasitoids probably played no role in the evolution of diphagous host relationships. Heteronomous hyperparasitoids, thought to have evolved from diphagous parasitoids, appear to be strong competitors because their males kill other parasitoids. However, an alternative hypothesis to the competition one, and based on the present study, is presented. Implications for the generally-held view, that competition is important in moulding species' characters, are discussed.
- Full Text:
- Authors: Walter, Grenville Hugh
- Date: 1984
- Subjects: Hymenoptera
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5620 , http://hdl.handle.net/10962/d1003746
- Description: Résumé: Heteronomous host relationships are unique to parasitoids in about 8 aphelinid genera. Males have host relationships quite distinct from those of their females. Females of ALL species are primary endoparasitoids of homopterous hosts. Males, on the other hand, may be either primary ectoparasitoids of the same host species as their conspecific females, or they may be hyperparasitic upon parasitoids within Homoptera, and some are primary endoparasitoids of moth eggs. Species in these groups are termed DIPHAGOUS PARASITOIDS, HETERONOMOUS HYPERPARASITOIDS and HETEROTROPHIC PARASITOIDS, respectively. The selective advantages proposed to explain the evolution of these unusual host relationships are examined in this thesis. The biology of a diphagous parasitoid was examined in detail because diphagous parasitism is considered the most primitive of heteronomous host relationships. Diphagous parasitism is thought to have evolved during a period when ovipositing females continuously encountered large proportions of parasitised hosts. Larval competition may have generated the selection pressures that favoured male ectoparasitism. Ectoparasitoids are known to be superior in competition against other larvae, even older ones. A series of observations was carried out on the diphagous parasitoid, Coccophagus bartletti. Information was gathered on oviposition and host-feeding behaviour, daily activity patterns, and sex ratios in the laboratory and field. This enabled the design and interpretation of a series of observations on the responses of mated C. bartletti females to already-parasitised hosts. The results indicate that competition from other parasitoids probably played no role in the evolution of diphagous host relationships. Heteronomous hyperparasitoids, thought to have evolved from diphagous parasitoids, appear to be strong competitors because their males kill other parasitoids. However, an alternative hypothesis to the competition one, and based on the present study, is presented. Implications for the generally-held view, that competition is important in moulding species' characters, are discussed.
- Full Text:
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