Community development education: the integration of individual and collective consciousness for community well-being within a social development paradigm in South Africa
- Authors: Maistry, Savathrie
- Date: 2008
- Subjects: Community development -- South Africa , Social planning -- South Africa , Public welfare -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD (Development Studies)
- Identifier: vital:11754 , http://hdl.handle.net/10353/182 , Community development -- South Africa , Social planning -- South Africa , Public welfare -- South Africa
- Description: This study focused on community development education and practice for the democratic and transformative South context. Social and community development are relatively new approaches to social welfare and community development is emerging as a discipline and profession to contribute to the goal of developmental social welfare. Community work, albeit to a minimal extent and not community development was viewed as a method of social work during apartheid. With community development being prioritized as an intervention strategy for poverty reduction by the national government, the gap in community development education needs to be addressed. The goal of the study was to develop an undergraduate curriculum framework for community development education that would produce a new generation of ethical community development professionals to contribute to the goal of developmental social welfare. The study focused on the integrated approach to community development education and practice; with education of the student as a whole human being as critical for community development in a transformative South Africa. To achieve its goal, the study identified three themes that were critical to the research: a conceptual framework, clarifying key terms; a curriculum framework for community development education; and qualities and ethics for a new generation of development practitioners. The qualitative study was based in the Eastern Cape Province, South Africa and because of the lack of a referential framework for community development education, the researcher looked towards learning from India which has over fifty years of experience in social and community development education and practice. The state of Kerala established a social development approach in 1957 and was chosen as a learning experience. The state’s Kudumbashree Mission which aims at poverty alleviation through the empowerment of women was chosen as a case study. The integral and values based education system of Sri Sathya Sai University in the state of Andhra Pradesh and the community development education and practice of Loyola College in the state of Kerala were examined. The research design was exploratory, conceptual, descriptive and developmental in nature. The qualitative methodology best suited the nature of this study and a combination of methods to obtain data from a variety of sources across national boundaries was employed. The participants interviewed in both countries were purposively selected for their involvement in social and community development directly as target groups, practitioners, managers and policy makers. The research produced a philosophical and theoretical framework that is unitary and integral and aligned with the current social development policy to guide community development education and practice. The unitary and integral framework encompasses the individual within the family and community context and locates the various dimensions of development such as the social, physical, cultural, psychological, spiritual, political and economical dimensions within a unitary platform. The framework is dominated by the holistic and humanistic philosophies without negating the rational and pragmatic perspectives. In conclusion, the study conceptualizes community development as a natural process; the integration of individual and collective consciousness and an intervention. The outcome of the study is a recommended curriculum framework for community development education that would be of relevance to the Eastern Cape Province in particular and for the South African context generally.
- Full Text:
- Date Issued: 2008
- Authors: Maistry, Savathrie
- Date: 2008
- Subjects: Community development -- South Africa , Social planning -- South Africa , Public welfare -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD (Development Studies)
- Identifier: vital:11754 , http://hdl.handle.net/10353/182 , Community development -- South Africa , Social planning -- South Africa , Public welfare -- South Africa
- Description: This study focused on community development education and practice for the democratic and transformative South context. Social and community development are relatively new approaches to social welfare and community development is emerging as a discipline and profession to contribute to the goal of developmental social welfare. Community work, albeit to a minimal extent and not community development was viewed as a method of social work during apartheid. With community development being prioritized as an intervention strategy for poverty reduction by the national government, the gap in community development education needs to be addressed. The goal of the study was to develop an undergraduate curriculum framework for community development education that would produce a new generation of ethical community development professionals to contribute to the goal of developmental social welfare. The study focused on the integrated approach to community development education and practice; with education of the student as a whole human being as critical for community development in a transformative South Africa. To achieve its goal, the study identified three themes that were critical to the research: a conceptual framework, clarifying key terms; a curriculum framework for community development education; and qualities and ethics for a new generation of development practitioners. The qualitative study was based in the Eastern Cape Province, South Africa and because of the lack of a referential framework for community development education, the researcher looked towards learning from India which has over fifty years of experience in social and community development education and practice. The state of Kerala established a social development approach in 1957 and was chosen as a learning experience. The state’s Kudumbashree Mission which aims at poverty alleviation through the empowerment of women was chosen as a case study. The integral and values based education system of Sri Sathya Sai University in the state of Andhra Pradesh and the community development education and practice of Loyola College in the state of Kerala were examined. The research design was exploratory, conceptual, descriptive and developmental in nature. The qualitative methodology best suited the nature of this study and a combination of methods to obtain data from a variety of sources across national boundaries was employed. The participants interviewed in both countries were purposively selected for their involvement in social and community development directly as target groups, practitioners, managers and policy makers. The research produced a philosophical and theoretical framework that is unitary and integral and aligned with the current social development policy to guide community development education and practice. The unitary and integral framework encompasses the individual within the family and community context and locates the various dimensions of development such as the social, physical, cultural, psychological, spiritual, political and economical dimensions within a unitary platform. The framework is dominated by the holistic and humanistic philosophies without negating the rational and pragmatic perspectives. In conclusion, the study conceptualizes community development as a natural process; the integration of individual and collective consciousness and an intervention. The outcome of the study is a recommended curriculum framework for community development education that would be of relevance to the Eastern Cape Province in particular and for the South African context generally.
- Full Text:
- Date Issued: 2008
Novel camphor derivatives as potential asymmetric alkylation auxiliaries
- Authors: Skiti-Mama, Neliswa
- Date: 2008
- Subjects: Alkylation , Chemistry, Organic
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10372 , http://hdl.handle.net/10948/1077 , Alkylation , Chemistry, Organic
- Description: The investigation has been focussed on the synthesis and characterisation of camphor-derived chiral auxiliaries that incorporate two camphor skeletons and an evaluation of their stereodirecting potential in ester α-benzylation reactions. Two regioisomeric camphorquinone-derived monoketals were synthesised and identified by 1D- and 2D-NMR, and X-ray crystallography. The stereo-directing potential of the alcohols that resulted from reduction of these ketones as chiral auxiliaries in the alkylation of carboxylate ester derivatives has been studied. The diastereoselectivities shown by NMR spectroscopy range from 14- 30 % d.e. for (1R,2 S, 3R) -2 ,2-[ (1R, 2 S, 3R) -bornane-2,3-dioxy] - bornan-3-ol and 68-74 % d.e. for (1R, 2S ,3R) -3 ,3-[ (1R, 2S ,3R) - bornane-2, 3 -dioxy]bornan-2-ol with selectivities that correlate with the size of the alkyl group in the ester moiety. Trapping of the enolates generated from (1R, 2S ,3R)-2, 2 -[(1R,2 S, 3R) -bornane- 2,3-dioxy]bornan-3-yl propanoate afforded both E- and Z-silyl ketene acetal derivatives in the ratio of 64:36 confirming the formation of both possible enolate structures during enolization. Chiral auxiliaries containing a hemiaminal ether blocking group as well as two chiral alcohols containing monothio-ketal blocking groups have also been synthesised. α-Benzylation of their corresponding propanoate esters afforded the alkylated product with disappointingly low diastereos electivities. Asymmetric reduction of α-keto esters attached to (1R, 2 S, 3R) - 2,2- [ (1R,2 S, 3R) -bornane-2, 3 -dioxy]bornan-3-ol and (1R, 2S ,3R) - 3,3- [ (1R,2 S, 3R) -bornane-2, 3 -dioxy]bornan-2-ol with metal hydrides proceeded with selectivities of up to 30 % d.e. Modelling of the keto ester derivatives at DFT levels provided useful insights into possible conformations adopted by the two α-keto esters and hence the preferred face of attack by metal hydride during reduction.
- Full Text:
- Date Issued: 2008
- Authors: Skiti-Mama, Neliswa
- Date: 2008
- Subjects: Alkylation , Chemistry, Organic
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10372 , http://hdl.handle.net/10948/1077 , Alkylation , Chemistry, Organic
- Description: The investigation has been focussed on the synthesis and characterisation of camphor-derived chiral auxiliaries that incorporate two camphor skeletons and an evaluation of their stereodirecting potential in ester α-benzylation reactions. Two regioisomeric camphorquinone-derived monoketals were synthesised and identified by 1D- and 2D-NMR, and X-ray crystallography. The stereo-directing potential of the alcohols that resulted from reduction of these ketones as chiral auxiliaries in the alkylation of carboxylate ester derivatives has been studied. The diastereoselectivities shown by NMR spectroscopy range from 14- 30 % d.e. for (1R,2 S, 3R) -2 ,2-[ (1R, 2 S, 3R) -bornane-2,3-dioxy] - bornan-3-ol and 68-74 % d.e. for (1R, 2S ,3R) -3 ,3-[ (1R, 2S ,3R) - bornane-2, 3 -dioxy]bornan-2-ol with selectivities that correlate with the size of the alkyl group in the ester moiety. Trapping of the enolates generated from (1R, 2S ,3R)-2, 2 -[(1R,2 S, 3R) -bornane- 2,3-dioxy]bornan-3-yl propanoate afforded both E- and Z-silyl ketene acetal derivatives in the ratio of 64:36 confirming the formation of both possible enolate structures during enolization. Chiral auxiliaries containing a hemiaminal ether blocking group as well as two chiral alcohols containing monothio-ketal blocking groups have also been synthesised. α-Benzylation of their corresponding propanoate esters afforded the alkylated product with disappointingly low diastereos electivities. Asymmetric reduction of α-keto esters attached to (1R, 2 S, 3R) - 2,2- [ (1R,2 S, 3R) -bornane-2, 3 -dioxy]bornan-3-ol and (1R, 2S ,3R) - 3,3- [ (1R,2 S, 3R) -bornane-2, 3 -dioxy]bornan-2-ol with metal hydrides proceeded with selectivities of up to 30 % d.e. Modelling of the keto ester derivatives at DFT levels provided useful insights into possible conformations adopted by the two α-keto esters and hence the preferred face of attack by metal hydride during reduction.
- Full Text:
- Date Issued: 2008
Communal production systems of goats raised by resource-poor farmers in the Eastern Cape Province of South Africa
- Authors: Gwaze, Francisca Rumosa
- Date: 2008
- Subjects: Agriculture -- Economic aspects -- South Africa -- Eastern Cape , Commons -- South Africa -- Eastern Cape , Pastoral systems -- Economic aspects -- South Africa -- Eastern Cape , Goats -- Economic aspects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD (Animal Science)
- Identifier: vital:11578 , http://hdl.handle.net/10353/172 , Agriculture -- Economic aspects -- South Africa -- Eastern Cape , Commons -- South Africa -- Eastern Cape , Pastoral systems -- Economic aspects -- South Africa -- Eastern Cape , Goats -- Economic aspects -- South Africa -- Eastern Cape
- Description: Goats significantly contribute towards the subsistence, economic and social livelihoods of many resource-poor farmers in developing countries, the majority of which own goats. There, however, is dearth of information on communal goat production potential and roles to the rural populace. The broad objective of the study was to evaluate production practices, constraints, production efficiency and to determine nutritional and health status of goats raised by resource-poor communal farmers in the Eastern Cape Province of South Africa. Roles and management systems of goats, goat flock dynamics and, prevalence and loads of gastrointestinal infections and the nutritional status of goats in the study areas were determined. The relationships among body weight, body condition score, faecal egg counts and, haematological and biochemical profiles were also determined. Mean goat flock sizes per household were similar between the two districts studied; Amatole (14.0 ± 0.31) and Alfred Nzo (14.1 ± 1.42). Seventy-nine percent of households in Amatole and 78% in Alfred Nzo kept goats for ceremonies, such as the initiation ceremonies. Goat houses in the two districts were poorly constructed. Thirty two percent of farmers in Alfred Nzo district and 27% in Amatole district reported low buck to doe ratios, suggesting that inbreeding might have been reducing productivity of their flocks. Kid mortality had two major peaks; in May (21%) and in September (21%). Goat production potential (GPP), the proportion of mature and growing goats to the total flock size, was affected by gender of owner of goats. Goats owned by female had a significantly lower GPP value of 0.63 ± 0.015 than goats owned by male farmers (0.70 ± 0.010). Month also significantly affected GPP with the highest (P < 0.05) GPP recorded in May, June and July and the lowest in March and April. Village affected GPP with values for Nkosana and Qawukeni being significantly higher than for Mankone. Goat production potential was also higher (P < 0.05) in small flocks (0.04 ± 0.008) than in large flocks (0.02 ± 0.008). Goat production efficiency (GPE) ranged from 0.11 ± 0.193 in April to 1.55 ± 0.193 in December. The most prevalent gastrointestinal eggs were the strongyle egg type (68.4 ± 8.49 in Qawukeni and 96.1 ± 12.01 in Nkosana) followed by coccidia (53.3 ± 8.76 in Qawukeni and 68.8 ± 8.00 in Mankone). The other identified nematodes were Strongyloides and Trichostrongylus egg types. The trematodes observed were Fasciola and Paramphistomum species. High loads of strongyle eggs were observed in the hot-wet season and the post-rainy season, whilst the other egg types showed a peak in the hot-wet season only. For most of the gastrointestinal parasite eggs, prevalence was higher (P < 0.05) in the sour rangeland compared to the sweet rangeland. Higher (P < 0.05) levels of total protein (TP), globulin, aspartate aminotransferase (AST) and creatinine kinase (CK) levels were recorded in the wet than in the dry season. Body condition scores were positively correlated (P < 0.05) to albumin, body weight and packed cell volume. However, body condition scores were negatively correlated to TP, glucose, alanine transaminase (ALT) and AST. Strongyle egg loads were positively correlated to FAMACHA scores, packed cell volume, body weight and body condition score. The observed high globulin levels suggested a chronic health challenge. Thus, it is fundamental to devise affordable interventions for the control of gastrointestinal parasites in communal goats leading to improved goat productivity and hence rural livelihood
- Full Text:
- Date Issued: 2008
- Authors: Gwaze, Francisca Rumosa
- Date: 2008
- Subjects: Agriculture -- Economic aspects -- South Africa -- Eastern Cape , Commons -- South Africa -- Eastern Cape , Pastoral systems -- Economic aspects -- South Africa -- Eastern Cape , Goats -- Economic aspects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD (Animal Science)
- Identifier: vital:11578 , http://hdl.handle.net/10353/172 , Agriculture -- Economic aspects -- South Africa -- Eastern Cape , Commons -- South Africa -- Eastern Cape , Pastoral systems -- Economic aspects -- South Africa -- Eastern Cape , Goats -- Economic aspects -- South Africa -- Eastern Cape
- Description: Goats significantly contribute towards the subsistence, economic and social livelihoods of many resource-poor farmers in developing countries, the majority of which own goats. There, however, is dearth of information on communal goat production potential and roles to the rural populace. The broad objective of the study was to evaluate production practices, constraints, production efficiency and to determine nutritional and health status of goats raised by resource-poor communal farmers in the Eastern Cape Province of South Africa. Roles and management systems of goats, goat flock dynamics and, prevalence and loads of gastrointestinal infections and the nutritional status of goats in the study areas were determined. The relationships among body weight, body condition score, faecal egg counts and, haematological and biochemical profiles were also determined. Mean goat flock sizes per household were similar between the two districts studied; Amatole (14.0 ± 0.31) and Alfred Nzo (14.1 ± 1.42). Seventy-nine percent of households in Amatole and 78% in Alfred Nzo kept goats for ceremonies, such as the initiation ceremonies. Goat houses in the two districts were poorly constructed. Thirty two percent of farmers in Alfred Nzo district and 27% in Amatole district reported low buck to doe ratios, suggesting that inbreeding might have been reducing productivity of their flocks. Kid mortality had two major peaks; in May (21%) and in September (21%). Goat production potential (GPP), the proportion of mature and growing goats to the total flock size, was affected by gender of owner of goats. Goats owned by female had a significantly lower GPP value of 0.63 ± 0.015 than goats owned by male farmers (0.70 ± 0.010). Month also significantly affected GPP with the highest (P < 0.05) GPP recorded in May, June and July and the lowest in March and April. Village affected GPP with values for Nkosana and Qawukeni being significantly higher than for Mankone. Goat production potential was also higher (P < 0.05) in small flocks (0.04 ± 0.008) than in large flocks (0.02 ± 0.008). Goat production efficiency (GPE) ranged from 0.11 ± 0.193 in April to 1.55 ± 0.193 in December. The most prevalent gastrointestinal eggs were the strongyle egg type (68.4 ± 8.49 in Qawukeni and 96.1 ± 12.01 in Nkosana) followed by coccidia (53.3 ± 8.76 in Qawukeni and 68.8 ± 8.00 in Mankone). The other identified nematodes were Strongyloides and Trichostrongylus egg types. The trematodes observed were Fasciola and Paramphistomum species. High loads of strongyle eggs were observed in the hot-wet season and the post-rainy season, whilst the other egg types showed a peak in the hot-wet season only. For most of the gastrointestinal parasite eggs, prevalence was higher (P < 0.05) in the sour rangeland compared to the sweet rangeland. Higher (P < 0.05) levels of total protein (TP), globulin, aspartate aminotransferase (AST) and creatinine kinase (CK) levels were recorded in the wet than in the dry season. Body condition scores were positively correlated (P < 0.05) to albumin, body weight and packed cell volume. However, body condition scores were negatively correlated to TP, glucose, alanine transaminase (ALT) and AST. Strongyle egg loads were positively correlated to FAMACHA scores, packed cell volume, body weight and body condition score. The observed high globulin levels suggested a chronic health challenge. Thus, it is fundamental to devise affordable interventions for the control of gastrointestinal parasites in communal goats leading to improved goat productivity and hence rural livelihood
- Full Text:
- Date Issued: 2008
A model for sustainable operational excellence through knowledge management practices and continuous improvement principles
- Beeken, Wilhelm Frederik Hartmann
- Authors: Beeken, Wilhelm Frederik Hartmann
- Date: 2008
- Subjects: Organizational effectiveness , Knowledge management
- Language: English
- Type: Thesis , Doctoral , DBA
- Identifier: vital:8699 , http://hdl.handle.net/10948/1061 , Organizational effectiveness , Knowledge management
- Description: Integrating Knowledge Management maturity with associated Continuous Improvement efforts in order to remain competitive, is absent in most Operational Excellence initiatives. Furthermore, the intertwined relationship of Continuous Improvement and work development becomes a crucial focus area for organisations that wish to establish a continuously evolving management system consisting of core values, methodologies and tools with the aim of creating more satisfied customers with less resources. The old industrial paradigm that focused on labour, capital, materials, and energy viewed technology and knowledge as external influences on production. This framework is now being challenged and a new trend is emerging. This trend seeks to transform the old industrial system to that of a knowledge-based which one can lead to innovation and hence economic advantage. Continuous Improvement as a concept has roots in many other fields, including social-technical system design, human relations progress and the discussion surrounding ‘lean manufacturing’. This study will focus on Continuous Improvement as a noun, referring to on the outcome of the process of a stream of emergent innovations. The primary objective of the study is to create a model that will present an organisation with a three-layer knowledge reference process grid, which will align and depict the surrounding business knowledge functions, knowledge-enabling processes and knowledge-manipulating processes aiming for enabling Operational Excellence. This study promotes the theory that the cognitive domain layer, functional domain layer and resources layer of an organisation can be increasingly stimulated by focusing effort through Continuous Improvement routines towards the associated inter-organisational knowledge processes sustaining Operational Excellence. The proposed model is structured to review, compare, evaluate and integrate existing Knowledge Management practices of ii an organisation within the context of clear definitions for important concepts of Knowledge Management. Additionally the model provides an assessment instrument for evaluating the organisation’s Knowledge Management maturity level. The study concerns itself with two concepts towards business value creation which will lead to increased Operational Excellence. Firstly, the maturity of Knowledge Management processes, and secondly the level of the organisation wide process of focused and continuous incremental improvement namely, Continuous Improvement. A case study with PriceWaterhouseCoopers was concluded and an on-line Internet survey was used with a stratified sample from knowledge workers to test the factors from both a Knowledge Management and Continuous Improvement perspective. These factors were verified by means of a hypotheses network, describing in a structured and descriptive way, the importance of Knowledge Management and Continuous Improvement collectively on sustainable Operational Excellence as an integral development of Operational Excellence. With respect to Knowledge Management practices, the hypothesis network proposed at least three domains, which of knowledge generation, knowledge mobilisation and knowledge application as important input to the proposed process grid of knowledge development and associated layer elements. From a Continuous Improvement principles perspective it is apparent that elements from Continuous Improvement routines and Continuous Improvement characteristics are associated with the organisation Continuous Improvement ability. These findings are also a result of the deliberate design of processes, tools, structures and environments with the intent to increase, renew, share or improve the use of knowledge represented in any of the three elements for structural, human and social of intellectual capital. The proposed model combines the framework of the Boyd cycle as it is conceptualized as self-assessment activities, for it becomes possible to use them as basis of a self-assessment with sense making navigational properties across iii the proposed knowledge process grid for the model. The model will facilitate the concept of a three-layer knowledge reference process grid, which represents the main components of the knowledge processes within the cognitive domain layer, functional layer and resources layer of an organisation. The proposed model will deliver a single value that co-exists with the Knowledge Management maturity level and Continuous Improvement readiness index rating attained. Logical relationships to dynamic, evolving and flexible enabling Knowledge Management practices for each layer of the proposed three-layer knowledge reference process grid will be integrated as output of the proposed model. The research has limitations as Knowledge Management practices were measured using a subjective norm scale. It is suggested that a more comprehensive measure of Knowledge Management maturity processes may be needed to represent this construct. The complexity of the proposed model and the number of associated variables included in the results need further confirmation using possible multiple samples and additional measures of Knowledge Management maturity and Continuous Improvement readiness elements. The benefit of the proposed model as a practical Operational Excellence tool is to overcome the perceived gap of implementing Knowledge Management practices and Continuous Improvement principles collectively to deliver and sustain Operational Excellence.
- Full Text:
- Date Issued: 2008
- Authors: Beeken, Wilhelm Frederik Hartmann
- Date: 2008
- Subjects: Organizational effectiveness , Knowledge management
- Language: English
- Type: Thesis , Doctoral , DBA
- Identifier: vital:8699 , http://hdl.handle.net/10948/1061 , Organizational effectiveness , Knowledge management
- Description: Integrating Knowledge Management maturity with associated Continuous Improvement efforts in order to remain competitive, is absent in most Operational Excellence initiatives. Furthermore, the intertwined relationship of Continuous Improvement and work development becomes a crucial focus area for organisations that wish to establish a continuously evolving management system consisting of core values, methodologies and tools with the aim of creating more satisfied customers with less resources. The old industrial paradigm that focused on labour, capital, materials, and energy viewed technology and knowledge as external influences on production. This framework is now being challenged and a new trend is emerging. This trend seeks to transform the old industrial system to that of a knowledge-based which one can lead to innovation and hence economic advantage. Continuous Improvement as a concept has roots in many other fields, including social-technical system design, human relations progress and the discussion surrounding ‘lean manufacturing’. This study will focus on Continuous Improvement as a noun, referring to on the outcome of the process of a stream of emergent innovations. The primary objective of the study is to create a model that will present an organisation with a three-layer knowledge reference process grid, which will align and depict the surrounding business knowledge functions, knowledge-enabling processes and knowledge-manipulating processes aiming for enabling Operational Excellence. This study promotes the theory that the cognitive domain layer, functional domain layer and resources layer of an organisation can be increasingly stimulated by focusing effort through Continuous Improvement routines towards the associated inter-organisational knowledge processes sustaining Operational Excellence. The proposed model is structured to review, compare, evaluate and integrate existing Knowledge Management practices of ii an organisation within the context of clear definitions for important concepts of Knowledge Management. Additionally the model provides an assessment instrument for evaluating the organisation’s Knowledge Management maturity level. The study concerns itself with two concepts towards business value creation which will lead to increased Operational Excellence. Firstly, the maturity of Knowledge Management processes, and secondly the level of the organisation wide process of focused and continuous incremental improvement namely, Continuous Improvement. A case study with PriceWaterhouseCoopers was concluded and an on-line Internet survey was used with a stratified sample from knowledge workers to test the factors from both a Knowledge Management and Continuous Improvement perspective. These factors were verified by means of a hypotheses network, describing in a structured and descriptive way, the importance of Knowledge Management and Continuous Improvement collectively on sustainable Operational Excellence as an integral development of Operational Excellence. With respect to Knowledge Management practices, the hypothesis network proposed at least three domains, which of knowledge generation, knowledge mobilisation and knowledge application as important input to the proposed process grid of knowledge development and associated layer elements. From a Continuous Improvement principles perspective it is apparent that elements from Continuous Improvement routines and Continuous Improvement characteristics are associated with the organisation Continuous Improvement ability. These findings are also a result of the deliberate design of processes, tools, structures and environments with the intent to increase, renew, share or improve the use of knowledge represented in any of the three elements for structural, human and social of intellectual capital. The proposed model combines the framework of the Boyd cycle as it is conceptualized as self-assessment activities, for it becomes possible to use them as basis of a self-assessment with sense making navigational properties across iii the proposed knowledge process grid for the model. The model will facilitate the concept of a three-layer knowledge reference process grid, which represents the main components of the knowledge processes within the cognitive domain layer, functional layer and resources layer of an organisation. The proposed model will deliver a single value that co-exists with the Knowledge Management maturity level and Continuous Improvement readiness index rating attained. Logical relationships to dynamic, evolving and flexible enabling Knowledge Management practices for each layer of the proposed three-layer knowledge reference process grid will be integrated as output of the proposed model. The research has limitations as Knowledge Management practices were measured using a subjective norm scale. It is suggested that a more comprehensive measure of Knowledge Management maturity processes may be needed to represent this construct. The complexity of the proposed model and the number of associated variables included in the results need further confirmation using possible multiple samples and additional measures of Knowledge Management maturity and Continuous Improvement readiness elements. The benefit of the proposed model as a practical Operational Excellence tool is to overcome the perceived gap of implementing Knowledge Management practices and Continuous Improvement principles collectively to deliver and sustain Operational Excellence.
- Full Text:
- Date Issued: 2008
Utility of the cognitive assessment system (CAS) to predict reading proficiency in grade 1
- Authors: Hüttenrauch, Maria Eleonore
- Date: 2008
- Subjects: Das-Naglieri Cognitive Assessment System , Intelligence tests for preliterates , Cognition in children , Reading disability
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9839 , http://hdl.handle.net/10948/965 , Das-Naglieri Cognitive Assessment System , Intelligence tests for preliterates , Cognition in children , Reading disability
- Description: Reading disability, as the most commonly diagnosed learning disability, continues to pose a tenacious problem to teachers, practitioners and researchers. In an effort to understand the causes of reading disability, voluminous research has been undertaken over the past decades to pinpoint its causes or developmental stumbling blocks. One approach, the Planning, Attention, Simultaneous, and Successive processing (PASS) model, combines neuropsychological theory with elements from cognitive psychology. Based on this model, the Cognitive Assessment System (CAS), as well as methods of intervention for reading disability were developed. Although many studies have been conducted that investigated reading disability in terms of PASS cognitive processes, the final version of the CAS and its predictive utility with respect to reading disability has not been explored to date. The present study aimed to investigate the utility of the CAS, administered at the beginning of grade 1, to predict reading proficiency at the end of grade 1. The sample was comprised of 119 “average” (i.e., belonging to the general population) grade 1 students from schools of the Calgary Board of Education (CBE). The Basic Battery of the CAS was administered to the children in the sample at the beginning of grade 1, as well as four reading subtests of the Woodcock-Johnson Tests of Achievement – Third Edition (WJ-III ACH) at the end of grade 1. The WJ-III ACH yielded a cluster score for basic reading and one for reading comprehension. Correlational and regression analyses were used to address the first aim of this study, namely to explore the relationship between students’ scores on the CAS and their later reading proficiency. To this end, the children’s CAS Full Scale scores and WJ-III ACH cluster scores were subjected to a hierarchical regression analysis, whereby age, gender, and - xviii - SES were kept constant by entering them first in the equation. Next, the relationship between students’ PASS scale scores and the CAS subtest scores respectively and scores on the WJ-III ACH Basic Reading and Reading Comprehension Cluster scores was explored by means of stepwise regression analysis. To improve on the generalizability of results, the regression analyses were conducted on a randomly drawn analysis sample consisting of 80% of the sample, and cross-validated on the remaining 20% of the sample. The second aim of the present study was to ascertain whether clusters could be identified on the basis of CAS performance as well as levels of reading proficiency. To this end, the children’s CAS FS scores, PASS scale scores, and CAS subtest scores were subjected to cluster analyses. The investigation of aim 1 yielded some encouraging results, in that it was found that, together with the covariates: • The CAS FS emerged as a moderately strong predictor of both basic reading and reading comprehension; • Successive processing, in particular the Word Series subtest, significantly predicted basic reading skills; • Successive and simultaneous processing, particularly the Nonverbal Matrices and Sentence Repetition subtests, were significant predictors of reading comprehension; The second aim, which explored the relationship between patterns of CAS cognitive processes and their relationship with reading proficiency, yielded: • Two clusters with distinctly different PASS scale scores and with significant differences between their levels of reading proficiency. Higher PASS scales scores, particularly on the Attention and Planning scales, were associated with higher reading proficiency scores. • Four clusters with distinctly different CAS subtest scores that were also associated with distinctly different levels of reading performance. Good - xix - reading proficiency was associated with good CAS performance, whereas weaker reading proficiency was linked to weaker CAS performance. Biographical variables, such as age and SES were found to be related to performance on the CAS and reading proficiency, while gender did not emerge as an important predictor variable. The present study demonstrated the usefulness of the CAS, particularly its Successive and Simultaneous scales, as potential early predictor of reading disability. An exploration of the relationship between patterns of CAS cognitive processes and later reading proficiency also yielded encouraging and interesting results.
- Full Text:
- Date Issued: 2008
- Authors: Hüttenrauch, Maria Eleonore
- Date: 2008
- Subjects: Das-Naglieri Cognitive Assessment System , Intelligence tests for preliterates , Cognition in children , Reading disability
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9839 , http://hdl.handle.net/10948/965 , Das-Naglieri Cognitive Assessment System , Intelligence tests for preliterates , Cognition in children , Reading disability
- Description: Reading disability, as the most commonly diagnosed learning disability, continues to pose a tenacious problem to teachers, practitioners and researchers. In an effort to understand the causes of reading disability, voluminous research has been undertaken over the past decades to pinpoint its causes or developmental stumbling blocks. One approach, the Planning, Attention, Simultaneous, and Successive processing (PASS) model, combines neuropsychological theory with elements from cognitive psychology. Based on this model, the Cognitive Assessment System (CAS), as well as methods of intervention for reading disability were developed. Although many studies have been conducted that investigated reading disability in terms of PASS cognitive processes, the final version of the CAS and its predictive utility with respect to reading disability has not been explored to date. The present study aimed to investigate the utility of the CAS, administered at the beginning of grade 1, to predict reading proficiency at the end of grade 1. The sample was comprised of 119 “average” (i.e., belonging to the general population) grade 1 students from schools of the Calgary Board of Education (CBE). The Basic Battery of the CAS was administered to the children in the sample at the beginning of grade 1, as well as four reading subtests of the Woodcock-Johnson Tests of Achievement – Third Edition (WJ-III ACH) at the end of grade 1. The WJ-III ACH yielded a cluster score for basic reading and one for reading comprehension. Correlational and regression analyses were used to address the first aim of this study, namely to explore the relationship between students’ scores on the CAS and their later reading proficiency. To this end, the children’s CAS Full Scale scores and WJ-III ACH cluster scores were subjected to a hierarchical regression analysis, whereby age, gender, and - xviii - SES were kept constant by entering them first in the equation. Next, the relationship between students’ PASS scale scores and the CAS subtest scores respectively and scores on the WJ-III ACH Basic Reading and Reading Comprehension Cluster scores was explored by means of stepwise regression analysis. To improve on the generalizability of results, the regression analyses were conducted on a randomly drawn analysis sample consisting of 80% of the sample, and cross-validated on the remaining 20% of the sample. The second aim of the present study was to ascertain whether clusters could be identified on the basis of CAS performance as well as levels of reading proficiency. To this end, the children’s CAS FS scores, PASS scale scores, and CAS subtest scores were subjected to cluster analyses. The investigation of aim 1 yielded some encouraging results, in that it was found that, together with the covariates: • The CAS FS emerged as a moderately strong predictor of both basic reading and reading comprehension; • Successive processing, in particular the Word Series subtest, significantly predicted basic reading skills; • Successive and simultaneous processing, particularly the Nonverbal Matrices and Sentence Repetition subtests, were significant predictors of reading comprehension; The second aim, which explored the relationship between patterns of CAS cognitive processes and their relationship with reading proficiency, yielded: • Two clusters with distinctly different PASS scale scores and with significant differences between their levels of reading proficiency. Higher PASS scales scores, particularly on the Attention and Planning scales, were associated with higher reading proficiency scores. • Four clusters with distinctly different CAS subtest scores that were also associated with distinctly different levels of reading performance. Good - xix - reading proficiency was associated with good CAS performance, whereas weaker reading proficiency was linked to weaker CAS performance. Biographical variables, such as age and SES were found to be related to performance on the CAS and reading proficiency, while gender did not emerge as an important predictor variable. The present study demonstrated the usefulness of the CAS, particularly its Successive and Simultaneous scales, as potential early predictor of reading disability. An exploration of the relationship between patterns of CAS cognitive processes and later reading proficiency also yielded encouraging and interesting results.
- Full Text:
- Date Issued: 2008
A historic-hermeneutic critique of luthiery with specific reference to selected South African guiter builders
- Authors: Bower, Rudi
- Date: 2008
- Subjects: Guitar -- Construction , Guitar -- History
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:8512 , http://hdl.handle.net/10948/779 , Guitar -- Construction , Guitar -- History
- Description: This study uses a general historical overview of luthiery that provides the reader with a basic understanding of construction techniques and terminology as a point of departure. From the outset the lack of consensus over an ideal or desired construction technique is highlighted. However, Torres is credited with the establishing of a perceived Spanish tradition of guitar construction and acknowledged as the “father” of the modern guitar. This will serve as a basic framework in which a discussion of six prominent past and present international luthiers can occur. These luthiers, namely Antonio de Torres, Hermann Hauser, Robert Bouchet, Daniel Friederich, Jose Romanillos and Greg Smallman are included in this study by virtue of their influence on the South African luthiers that are featured here. It is noted that these six luthiers, with the exception of Greg Smallman, all adhere to the “Spanish tradition” of guitar construction. Smallman can be considered a foremost proponent of a more recent “modern” school of guitar construction characterized by various innovative construction techniques. These are a result of new demands placed on the guitar as performance instrument because of larger concert venues and more collaboration with different instruments, resulting in a need for a stronger tone and more projection and penetration in sound. These two “poles” of luthiery are then manifested in the discussion on the seven featured South African luthiers. Alistair Thompson, Colin Cleveland, Mervyn Davis, Garth Pickard, Marc Maingard, Rodney Stedall and Hans van den Berg are discussed with special mention made of the features of their instruments, woods used and thoughts on luthiery, against the backdrop of their biographies. The four South African luthiers who build within the “Spanish tradition” (Pickard, Maingard, Stedall and Van den Berg) are distinguished from the three who build outside this so-called tradition (Thompson, Cleveland, Davis). South African luthiery is therefore shown to be an accurate microcosm of luthiery in global terms with styles of construction ranging from very “traditional” to very “modern”. The critical reflection on the information contained in this study appears in the form of a hermeneutic critique on luthiery that occurs within the parameters of the thought of two prominent hermeneutic thinkers, Martin Heidegger and his student, Hans-Georg Gadamer. It is shown that the collaboration that often occurs between guitar makers and performers can be related back to Gadamer and his analysis of Heidegger’s notion of the the hermeneutic circle. It is also argued that luthiery as practiced by the international and South African luthiers featured in this study can be seen both as art and technology in ancient Greek terms in that they are both a mode of revealing. Finally, it is shown how luthiery in its entirety can be viewed as a tradition and that different luthiers respond and add to this tradition in various ways.
- Full Text:
- Date Issued: 2008
- Authors: Bower, Rudi
- Date: 2008
- Subjects: Guitar -- Construction , Guitar -- History
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:8512 , http://hdl.handle.net/10948/779 , Guitar -- Construction , Guitar -- History
- Description: This study uses a general historical overview of luthiery that provides the reader with a basic understanding of construction techniques and terminology as a point of departure. From the outset the lack of consensus over an ideal or desired construction technique is highlighted. However, Torres is credited with the establishing of a perceived Spanish tradition of guitar construction and acknowledged as the “father” of the modern guitar. This will serve as a basic framework in which a discussion of six prominent past and present international luthiers can occur. These luthiers, namely Antonio de Torres, Hermann Hauser, Robert Bouchet, Daniel Friederich, Jose Romanillos and Greg Smallman are included in this study by virtue of their influence on the South African luthiers that are featured here. It is noted that these six luthiers, with the exception of Greg Smallman, all adhere to the “Spanish tradition” of guitar construction. Smallman can be considered a foremost proponent of a more recent “modern” school of guitar construction characterized by various innovative construction techniques. These are a result of new demands placed on the guitar as performance instrument because of larger concert venues and more collaboration with different instruments, resulting in a need for a stronger tone and more projection and penetration in sound. These two “poles” of luthiery are then manifested in the discussion on the seven featured South African luthiers. Alistair Thompson, Colin Cleveland, Mervyn Davis, Garth Pickard, Marc Maingard, Rodney Stedall and Hans van den Berg are discussed with special mention made of the features of their instruments, woods used and thoughts on luthiery, against the backdrop of their biographies. The four South African luthiers who build within the “Spanish tradition” (Pickard, Maingard, Stedall and Van den Berg) are distinguished from the three who build outside this so-called tradition (Thompson, Cleveland, Davis). South African luthiery is therefore shown to be an accurate microcosm of luthiery in global terms with styles of construction ranging from very “traditional” to very “modern”. The critical reflection on the information contained in this study appears in the form of a hermeneutic critique on luthiery that occurs within the parameters of the thought of two prominent hermeneutic thinkers, Martin Heidegger and his student, Hans-Georg Gadamer. It is shown that the collaboration that often occurs between guitar makers and performers can be related back to Gadamer and his analysis of Heidegger’s notion of the the hermeneutic circle. It is also argued that luthiery as practiced by the international and South African luthiers featured in this study can be seen both as art and technology in ancient Greek terms in that they are both a mode of revealing. Finally, it is shown how luthiery in its entirety can be viewed as a tradition and that different luthiers respond and add to this tradition in various ways.
- Full Text:
- Date Issued: 2008
A bioinorganic study of some cobalt(II) Schiff base complexes of variously substituted hydroxybenzaldimines
- Authors: Shaibu, Rafiu Olarewaju
- Date: 2008
- Subjects: Cobalt Schiff bases Artemia Spectrum analysis Ligands -- Analysis Bioinorganic chemistry Antineoplastic agents Cancer -- Chemotherapy Ligands -- Toxicity
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4394 , http://hdl.handle.net/10962/d1006009
- Description: Syntheses of Schiff bases were carried out by reacting salicylaldyhde, ortho-vanillin, para-vanillin or vanillin with aniline, 1-aminonaphthalene, 4- and 3-aminopyridine, and also with 2- and 3-aminomethylpyridine. The various Schiff bases obtained from the condensation reaction were reacted with CoCl₂.6H₂0, triethylamine stripped CoCl₂.6H₂0 or Co(CH₃COO)₂ to form cobalt(Il) complexes of ratio 2:1. The complexes obtained from cobalt chloride designated as the "A series" are of the general formulae ML₂X₂.nH₂0 , (L = Schiff base, X = chlorine) while those obtained from cobalt acetate or triethylamine stripped cobalt chloride denoted as "B" and C" are of the general formulae ML₂. nH₂0. The few complexes that do not follow the general formulae highlighted above are: IA [M(HL)₃.Cl₂], (L = N-phenylsalicylaldimine), 4A = (MLCl₂), (L = N-phenylvanaldiminato), 7 A and 21 A (ML₂), (L = N-naphthyl-o-vanaldiminato, and N-methy-2-pyridylsalicylaldiminato respectively), 8A = MLCI, (L = N-naphthylvanaldiminato), 12A = M₂L₃Cl₂, (L = N-4-pyridylvanaldiminato), 15A (MLCI), (L = N-3-pyridyl-o-vanaldiminato). The ligands and their complexes were characterized using elemental analyses and cobalt analysis using ICP, FT-IR spectroscopy (mid and far-IR), NIR-UV/vis (diffuse reflectance), UV/vis in an aprotic and a protic solvents, while mass spectrometry, ¹HNMR and ¹³CNMR, was used to further characterized the ligands. The tautomeric nature of the Schiff bases were determined by examining the behaviour of Schiff bases and their complexes in a protic (e.g. MeOH) and non-protic (e.g. DMF) polar solvents. The effects of solvents on the electronic behaviour of the compounds were also examined. Using CDCl₃, the NMR technique was further used to confirm the structures of the Schiff bases. The tentative geometry of the complexes was determined using the spectra information obtained from the far infrared and the diffuse reflectance spectroscopy. With few exceptions, most of the "A" series are tetrahedral or distorted tetrahedral, while the "B + C" are octahedral or pseudooctahedral. A small number of complexes are assigned square-planar geometry owing to the characteristic spectral behaviour shown. In order to determine their biological activity, two biological assay methods (antimicrobial testing and brine shrimp lethality assay) were used. Using disc method, the bacteriostatic and fungicidal activities of the various Schiff bases and their respective complexes to Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa as well as Aspergillus niger, were measured and the average inhibition zones are tabulated and analysed. Both the Schiff bases and their complexes showed varying bacteriostatic and fungicidal activity against the bacteria and fungus tested. The inhibition activity is concentration dependent and potential antibiotic and fungicides are identified. To determine the toxicity of the ligands and their corresponding cobalt(II) complexes, brine shrimp lethality assay was used. The LD₅₀ of the tested compounds were calculated and the results obtained were tabulated for comparison.
- Full Text:
- Date Issued: 2008
- Authors: Shaibu, Rafiu Olarewaju
- Date: 2008
- Subjects: Cobalt Schiff bases Artemia Spectrum analysis Ligands -- Analysis Bioinorganic chemistry Antineoplastic agents Cancer -- Chemotherapy Ligands -- Toxicity
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4394 , http://hdl.handle.net/10962/d1006009
- Description: Syntheses of Schiff bases were carried out by reacting salicylaldyhde, ortho-vanillin, para-vanillin or vanillin with aniline, 1-aminonaphthalene, 4- and 3-aminopyridine, and also with 2- and 3-aminomethylpyridine. The various Schiff bases obtained from the condensation reaction were reacted with CoCl₂.6H₂0, triethylamine stripped CoCl₂.6H₂0 or Co(CH₃COO)₂ to form cobalt(Il) complexes of ratio 2:1. The complexes obtained from cobalt chloride designated as the "A series" are of the general formulae ML₂X₂.nH₂0 , (L = Schiff base, X = chlorine) while those obtained from cobalt acetate or triethylamine stripped cobalt chloride denoted as "B" and C" are of the general formulae ML₂. nH₂0. The few complexes that do not follow the general formulae highlighted above are: IA [M(HL)₃.Cl₂], (L = N-phenylsalicylaldimine), 4A = (MLCl₂), (L = N-phenylvanaldiminato), 7 A and 21 A (ML₂), (L = N-naphthyl-o-vanaldiminato, and N-methy-2-pyridylsalicylaldiminato respectively), 8A = MLCI, (L = N-naphthylvanaldiminato), 12A = M₂L₃Cl₂, (L = N-4-pyridylvanaldiminato), 15A (MLCI), (L = N-3-pyridyl-o-vanaldiminato). The ligands and their complexes were characterized using elemental analyses and cobalt analysis using ICP, FT-IR spectroscopy (mid and far-IR), NIR-UV/vis (diffuse reflectance), UV/vis in an aprotic and a protic solvents, while mass spectrometry, ¹HNMR and ¹³CNMR, was used to further characterized the ligands. The tautomeric nature of the Schiff bases were determined by examining the behaviour of Schiff bases and their complexes in a protic (e.g. MeOH) and non-protic (e.g. DMF) polar solvents. The effects of solvents on the electronic behaviour of the compounds were also examined. Using CDCl₃, the NMR technique was further used to confirm the structures of the Schiff bases. The tentative geometry of the complexes was determined using the spectra information obtained from the far infrared and the diffuse reflectance spectroscopy. With few exceptions, most of the "A" series are tetrahedral or distorted tetrahedral, while the "B + C" are octahedral or pseudooctahedral. A small number of complexes are assigned square-planar geometry owing to the characteristic spectral behaviour shown. In order to determine their biological activity, two biological assay methods (antimicrobial testing and brine shrimp lethality assay) were used. Using disc method, the bacteriostatic and fungicidal activities of the various Schiff bases and their respective complexes to Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa as well as Aspergillus niger, were measured and the average inhibition zones are tabulated and analysed. Both the Schiff bases and their complexes showed varying bacteriostatic and fungicidal activity against the bacteria and fungus tested. The inhibition activity is concentration dependent and potential antibiotic and fungicides are identified. To determine the toxicity of the ligands and their corresponding cobalt(II) complexes, brine shrimp lethality assay was used. The LD₅₀ of the tested compounds were calculated and the results obtained were tabulated for comparison.
- Full Text:
- Date Issued: 2008
The separation of platinum and gold from an industrial feed solution
- Authors: Louw, Talana
- Date: 2008
- Subjects: Platinum -- Separation , Gold , Separation -- Technology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10400 , http://hdl.handle.net/10948/731 , Platinum -- Separation , Gold , Separation -- Technology
- Description: In this thesis, the aim was to develop resins which are platinum and gold specific to be utilized for the early removal of these metals from the industrial feed. Efforts were therefore directed towards the synthesis of silica based resins with active centra which were designed for platinum and gold specificity respectively. The large chlorometallate ions in the feed stream were characterized in terms of physical parameters relevant to phase distribution namely distortability (RD), charge density, softness (σ) etc. Matching cations for each of the types were investigated. In order to attempt the design of platinum specific resins different structural amines were used to aminate the silicone precursor and subsequently to fix these onto the silica framework. Two different solvents i.e. alcohol and dmf were used for this process, resulting in two sets of resins with different properties. For gold specific resins, various polyethers were attached to a different type of silicone precursor, which was attached to the silica framework. The design was based on previous experience with these ions with reference to their behaviour towards different types of cations. The platinum species PtCl6 2- and PtCl4 2-, the gold species AuCl4 -, as well as the most important contaminants in the feed stream were typified bearing in mind size, charge, charge density and distortability. Different types of cationic centra having differences in charge density, stereochemical crowding and extent of hydrophobicity were synthesized and tested both as solvent extractants (where possible) and silica based resins. The results indicated that partly screened secondary ammonium cationic resin species, which could be regarded as “intermediate”, proved to be satisfactory both in their high percentage extraction for PtCl4 2- and rejection of contaminants like chlororhodates, chloroiridates(III) and FeCl4 -. It was, however, necessary to work at a redox potential where iridium(IV) in the form of IrCl6 2- is absent. Various 2-aminoalkane resins were prepared with variation in the length of alkane group and synthesized in the two different solvents. The latter resulted in two sets of resins with different compactness also having significantly different properties with reference to platinum specificity, HCl effect and stripping potential. The 2- aminobutane and 2-aminoheptane resins both proved to be very satisfactory platinum specific resins with respect to selectivity, platinum capacity and stripping potential. The various physical parameters could be utilized to accommodate the chemical behaviour. To obtain gold specific resins, experiments were performed with resins having oxygen-donor atoms which can readily be protonated to form onium type cations for example amides and ether oxygen atoms. In the case of the latter, various polyethers with a different number of ether groups (polyether groups linked by ethylene and propylene groups) and variations of hydrophobicity (by substitution) have also been studied. Linked to the polyether groups were alkane and aryl groups. Those having 8 to 10 ether groups and aromatic tail ends proved to be moderately successful in terms of gold capacity and sharp breakthrough curves of their columns, however, platinum could not be very effectively rejected.
- Full Text:
- Date Issued: 2008
- Authors: Louw, Talana
- Date: 2008
- Subjects: Platinum -- Separation , Gold , Separation -- Technology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10400 , http://hdl.handle.net/10948/731 , Platinum -- Separation , Gold , Separation -- Technology
- Description: In this thesis, the aim was to develop resins which are platinum and gold specific to be utilized for the early removal of these metals from the industrial feed. Efforts were therefore directed towards the synthesis of silica based resins with active centra which were designed for platinum and gold specificity respectively. The large chlorometallate ions in the feed stream were characterized in terms of physical parameters relevant to phase distribution namely distortability (RD), charge density, softness (σ) etc. Matching cations for each of the types were investigated. In order to attempt the design of platinum specific resins different structural amines were used to aminate the silicone precursor and subsequently to fix these onto the silica framework. Two different solvents i.e. alcohol and dmf were used for this process, resulting in two sets of resins with different properties. For gold specific resins, various polyethers were attached to a different type of silicone precursor, which was attached to the silica framework. The design was based on previous experience with these ions with reference to their behaviour towards different types of cations. The platinum species PtCl6 2- and PtCl4 2-, the gold species AuCl4 -, as well as the most important contaminants in the feed stream were typified bearing in mind size, charge, charge density and distortability. Different types of cationic centra having differences in charge density, stereochemical crowding and extent of hydrophobicity were synthesized and tested both as solvent extractants (where possible) and silica based resins. The results indicated that partly screened secondary ammonium cationic resin species, which could be regarded as “intermediate”, proved to be satisfactory both in their high percentage extraction for PtCl4 2- and rejection of contaminants like chlororhodates, chloroiridates(III) and FeCl4 -. It was, however, necessary to work at a redox potential where iridium(IV) in the form of IrCl6 2- is absent. Various 2-aminoalkane resins were prepared with variation in the length of alkane group and synthesized in the two different solvents. The latter resulted in two sets of resins with different compactness also having significantly different properties with reference to platinum specificity, HCl effect and stripping potential. The 2- aminobutane and 2-aminoheptane resins both proved to be very satisfactory platinum specific resins with respect to selectivity, platinum capacity and stripping potential. The various physical parameters could be utilized to accommodate the chemical behaviour. To obtain gold specific resins, experiments were performed with resins having oxygen-donor atoms which can readily be protonated to form onium type cations for example amides and ether oxygen atoms. In the case of the latter, various polyethers with a different number of ether groups (polyether groups linked by ethylene and propylene groups) and variations of hydrophobicity (by substitution) have also been studied. Linked to the polyether groups were alkane and aryl groups. Those having 8 to 10 ether groups and aromatic tail ends proved to be moderately successful in terms of gold capacity and sharp breakthrough curves of their columns, however, platinum could not be very effectively rejected.
- Full Text:
- Date Issued: 2008
The rhizosphere as a bioprocess environment for the bioconversion of hard coal
- Authors: Igbinigie, Eric Egbe
- Date: 2008
- Subjects: Rhizosphere Biotechnology Bermuda grass Coal -- Microbiology Biomass conversion
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3924 , http://hdl.handle.net/10962/d1003983
- Description: Fundamental processes involved in the microbial degradation of coal and its derivatives have been well investigated and documented over the past two decades. However, limited progress in industrial application has been identified as bottleneck in further active development of the field. The sporadic and unanticipated growth of Cynodon dactylon (Bermuda grass) has been observed on the surface of some coal dumps in the Witbank coal mining area of South Africa. Preliminary investigations showed the formation of a humic soil-like material from the breakdown of hard coal in the root zone of these plants. The potential of this system to contribute to industrial scale bioprocessing of hard coal was investigated. This study involved an investigation of the C. dactylon/coal rhizosphere environment and demonstrated the presence of fungal species with known coal bioconversion capability. Amongst these Neosartorya fischeri was identified and its activity in coal bioconversion was described for the first time. Cynodon dactylon plant roots were also shown to be colonized by mycorrhizal fungi including Glomus, Paraglomus and Gigaspora species. The role of plant photosynthate translocation into the root zone, providing organic carbon supplementation of fungal coal bioconversion was investigated in deep liquid culture with the N. fischeri isolate used as the biocatalyst. Organic acids, sugars and complex organic carbon sources were investigated and it was shown that glutamate provided significant enhancement of bioconversion activity in this system. The performance of N. fischeri in coal bioconversion was compared with Phanaerochaete chrysosporium and Trametes versicolor, both previously described fungal species in the coal bioconversion application. Fourier transform infrared spectroscopy indicated more pronounced oxidation and introduction of nitro groups in the matrix of the humic acid product of coal bioconversion in N. fischeri and P. chrysosporium than for T. versicolor. Macro-elemental analysis of biomass-bound humic acid obtained from the N. fischeri catalyzed reaction showed an increase in the oxygen and nitrogen components and coupled with a reduction in carbon and hydrogen. Pyrolysis gas chromatography mass spectroscopy further supported the proposal that the mechanism of bioconversion involves oxygen and nitrogen insertion into the coal structure. The C. dactylon bituminous hard coal dump environment was simulated in a fixed-bed perfusion column bioreactor in which the contribution of organic supplement by the plant/mycorrhizal component of the system was investigated. The results enabled the proposal of a descriptive model accounting for the performance of the system in which the plant/mycorrhizal component introduces organic substances into the root zone. The non-mycorrhizal fungi utilize the organic carbon supplement in its attack on the coal substrate, breaking it down, and releasing plant nutrients and a soil-like substrate which in turn enables the growth of C. dactylon in this hostile environment. Based on these results, the Stacked Heap Coal Bioreactor concept was developed as a large-scale industrial bioprocess application based on heap-leach mineral processing technology. Field studies have confirmed that bituminous hard coal can be converted to a humic acid rich substrate in a stacked heap system inoculated with mycorrhizal and N. fischeri cultures and planted with C. dactylon.
- Full Text:
- Date Issued: 2008
- Authors: Igbinigie, Eric Egbe
- Date: 2008
- Subjects: Rhizosphere Biotechnology Bermuda grass Coal -- Microbiology Biomass conversion
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3924 , http://hdl.handle.net/10962/d1003983
- Description: Fundamental processes involved in the microbial degradation of coal and its derivatives have been well investigated and documented over the past two decades. However, limited progress in industrial application has been identified as bottleneck in further active development of the field. The sporadic and unanticipated growth of Cynodon dactylon (Bermuda grass) has been observed on the surface of some coal dumps in the Witbank coal mining area of South Africa. Preliminary investigations showed the formation of a humic soil-like material from the breakdown of hard coal in the root zone of these plants. The potential of this system to contribute to industrial scale bioprocessing of hard coal was investigated. This study involved an investigation of the C. dactylon/coal rhizosphere environment and demonstrated the presence of fungal species with known coal bioconversion capability. Amongst these Neosartorya fischeri was identified and its activity in coal bioconversion was described for the first time. Cynodon dactylon plant roots were also shown to be colonized by mycorrhizal fungi including Glomus, Paraglomus and Gigaspora species. The role of plant photosynthate translocation into the root zone, providing organic carbon supplementation of fungal coal bioconversion was investigated in deep liquid culture with the N. fischeri isolate used as the biocatalyst. Organic acids, sugars and complex organic carbon sources were investigated and it was shown that glutamate provided significant enhancement of bioconversion activity in this system. The performance of N. fischeri in coal bioconversion was compared with Phanaerochaete chrysosporium and Trametes versicolor, both previously described fungal species in the coal bioconversion application. Fourier transform infrared spectroscopy indicated more pronounced oxidation and introduction of nitro groups in the matrix of the humic acid product of coal bioconversion in N. fischeri and P. chrysosporium than for T. versicolor. Macro-elemental analysis of biomass-bound humic acid obtained from the N. fischeri catalyzed reaction showed an increase in the oxygen and nitrogen components and coupled with a reduction in carbon and hydrogen. Pyrolysis gas chromatography mass spectroscopy further supported the proposal that the mechanism of bioconversion involves oxygen and nitrogen insertion into the coal structure. The C. dactylon bituminous hard coal dump environment was simulated in a fixed-bed perfusion column bioreactor in which the contribution of organic supplement by the plant/mycorrhizal component of the system was investigated. The results enabled the proposal of a descriptive model accounting for the performance of the system in which the plant/mycorrhizal component introduces organic substances into the root zone. The non-mycorrhizal fungi utilize the organic carbon supplement in its attack on the coal substrate, breaking it down, and releasing plant nutrients and a soil-like substrate which in turn enables the growth of C. dactylon in this hostile environment. Based on these results, the Stacked Heap Coal Bioreactor concept was developed as a large-scale industrial bioprocess application based on heap-leach mineral processing technology. Field studies have confirmed that bituminous hard coal can be converted to a humic acid rich substrate in a stacked heap system inoculated with mycorrhizal and N. fischeri cultures and planted with C. dactylon.
- Full Text:
- Date Issued: 2008
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:
- Date Issued: 2008
- 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:
- Date Issued: 2008
The impact of the identification process and the corporate social responsibility process on the effectiveness of multi-racial advertising in South Africa
- Authors: Johnson, Guillaume Desire
- Date: 2008
- Subjects: Marketing -- South Africa Advertising -- South Africa Sales promotion -- South Africa Consumers' preferences -- South Africa Marketing research -- South Africa Consumer behavior -- South Africa Consumption (Economics) -- Social aspect Attribution (Social psychology) South Africans -- Race identity Race awareness -- South Africa Ethnopsychology -- South Africa Group identity Racially mixed people
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1196 , http://hdl.handle.net/10962/d1008263
- Description: Selecting actors to appear in an advertisement is an important decision which has a crucial impact on the effectiveness of an advertising campaign. The same message, delivered by different actors, produces varying outcomes among consumers. This dilemma concerning the choice of actors occurs particularly in multi-racial societies, such as South Africa, where advertisers have to target different sectors of the community. In multi-racial societies, the choice of actors in advertisements goes beyond the usual commercial reasons. Indeed, two dimensions are generally conferred to multi-racial advertising. Firstly, the use of multi-racial representations allows for the targeting of a wider population that also owns a wider purchasing power. Marketers who want to market their brand use, for example, white and black actors so that white and black consumers can identify with the actors and recognize themselves as the target of the advertisement. Secondly, the multi-racial representations of this type of advertising hold a social role that counteracts the segregated depiction of the society. Consumers who are exposed to a multi-racial advertisement might perceive this social dimension and attribute a social responsibility to the advertisement. The purpose of this thesis is to examine the influence of the above dimensions on the effectiveness of a multi-racial advertisement. On the one hand, this study investigates the Identification Process followed by a consumer exposed to a multi-racial advertisement. On the other hand, it examines how consumers attribute a social responsibility to a specific multiracial advertisement and how this attribution, in turn, influences their responses to the advertisement and brand. Finally, the impacts of both of these dimensions on consumer behaviour are compared and the most persuasive dimension is identified. This thesis draws on Attribution Theory and Identification Theory in arguing that there are strong economic imperatives for adopting a multi-racial advertising approach. The thesis develops a conceptual framework and tests empirically hypotheses regarding the key constructs and moderating variables. The empirical results point out that both dimensions symbiotically influence the effectiveness of a multi-racial advertisement. Specifically, the results highlight that the social responsibility attributed by the viewers to the advertisement influences their behaviour more than the Identification Process.
- Full Text:
- Date Issued: 2008
- Authors: Johnson, Guillaume Desire
- Date: 2008
- Subjects: Marketing -- South Africa Advertising -- South Africa Sales promotion -- South Africa Consumers' preferences -- South Africa Marketing research -- South Africa Consumer behavior -- South Africa Consumption (Economics) -- Social aspect Attribution (Social psychology) South Africans -- Race identity Race awareness -- South Africa Ethnopsychology -- South Africa Group identity Racially mixed people
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1196 , http://hdl.handle.net/10962/d1008263
- Description: Selecting actors to appear in an advertisement is an important decision which has a crucial impact on the effectiveness of an advertising campaign. The same message, delivered by different actors, produces varying outcomes among consumers. This dilemma concerning the choice of actors occurs particularly in multi-racial societies, such as South Africa, where advertisers have to target different sectors of the community. In multi-racial societies, the choice of actors in advertisements goes beyond the usual commercial reasons. Indeed, two dimensions are generally conferred to multi-racial advertising. Firstly, the use of multi-racial representations allows for the targeting of a wider population that also owns a wider purchasing power. Marketers who want to market their brand use, for example, white and black actors so that white and black consumers can identify with the actors and recognize themselves as the target of the advertisement. Secondly, the multi-racial representations of this type of advertising hold a social role that counteracts the segregated depiction of the society. Consumers who are exposed to a multi-racial advertisement might perceive this social dimension and attribute a social responsibility to the advertisement. The purpose of this thesis is to examine the influence of the above dimensions on the effectiveness of a multi-racial advertisement. On the one hand, this study investigates the Identification Process followed by a consumer exposed to a multi-racial advertisement. On the other hand, it examines how consumers attribute a social responsibility to a specific multiracial advertisement and how this attribution, in turn, influences their responses to the advertisement and brand. Finally, the impacts of both of these dimensions on consumer behaviour are compared and the most persuasive dimension is identified. This thesis draws on Attribution Theory and Identification Theory in arguing that there are strong economic imperatives for adopting a multi-racial advertising approach. The thesis develops a conceptual framework and tests empirically hypotheses regarding the key constructs and moderating variables. The empirical results point out that both dimensions symbiotically influence the effectiveness of a multi-racial advertisement. Specifically, the results highlight that the social responsibility attributed by the viewers to the advertisement influences their behaviour more than the Identification Process.
- Full Text:
- Date Issued: 2008
Assembly of Omegatetravirus virus-like particles in the yeast Saccharomyces cerevisiae
- Authors: Tomasicchio, Michele
- Date: 2008
- Subjects: Helicoverpa armigera Imbrasia cytherea Viruses RNA viruses Insects -- Viruses Lepidoptera -- Viruses Saccharomyces cerevisiae
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3930 , http://hdl.handle.net/10962/d1003989
- Description: The Tetraviridae are a family of ss (+) RNA viruses that specifically infect lepidopteran insects. Their icosahedral capsids are non-enveloped and approximately 40 nm in diameter with T=4 quasi-equivalent symmetry. The omegatetraviruses, which are structurally the best characterised in the family, include Helicoverpa armigera stunt virus (HaSV) and Nudaurelia capensis omega virus (NwV). The omegatetravirus procapsid is composed of 240 identical copies of the capsid precursor proteins, which undergo autoproteolytic cleavage at its carboxyl-terminus generating the mature capsid protein (b) and γ-peptide. This process occurs in vitro following a shift from pH 7.6 to pH 6.0. The viral capsid encapsidates two ss genomic RNAs: The larger RNA1 encodes the viral replicase as well as three small ORFs while RNA2 encodes the capsid precursor protein together with an overlapping ORF designated P17. While a wealth of structural data pertaining to the assembly and maturation of omegatetraviruses is available, little is known about how this relates to their lifecycle. The principle aim of the research described in this thesis was to use an experimental system developed in the yeast, Saccharomyces cerevisiae, to investigate the assembly of HaSV and NwV virus-like particles (VLPs) in terms of maturation and encapsidation of viral RNAs, in vivo. The yeast expression system used two promoter systems for expression of capsid precursor protein: in the first, a hybrid promoter (PGADH) was used for high-level expression, while the second, PGAL1, produced substantially lower levels of the virus capsid protein precursors. An increase in the level of HaSV capsid protein precursor (p71) via the PGADH promoter resulted in a dramatic increase in VLP assembly as compared with the PGAL system. A protein equivalent to the mature capsid protein (p64) appeared at later time intervals following induction of transcription. Transmission electron microscopic studies showed that p64 correlated with the presence of mature VLPs as opposed to procapsids in cells containing p71. This confirmed that the presence of p64 denoted maturation of VLPs in vivo. Further investigation indicated that maturation correlated with cell aging and the onset of apoptosis. It was shown that induction of apoptosis resulted in VLP maturation while inhibition of apoptosis prevented maturation. These results suggested that the process of apoptosis might be the trigger for maturation of virus procapsids in their host cells. The increase in the efficiency of VLP assembly observed in the high-level expression system was proposed to be due to an increase in the cellular concentrations of viral RNA. To test this hypothesis, HaSV P71 was co-expressed with either P71 mRNA or full length RNA2. An increase in the solubility of p71 was observed in cells expressing increased levels of both RNAs, but there was no increase in the efficiency of VLP assembly. Northern analysis of encapsidated RNAs revealed that there was no selective encapsidation of either P71 mRNA or viral RNA2. This data indicated that the increase in viral RNA was not the reason for increased efficiency of VLP assembly, but most likely resulted from higher concentrations of p71 itself. It was decided to determine whether a highly efficient nodavirus replication system developed in yeast for heterologous production of proteins, could be used as a method for expressing the capsid protein precursor. The aim of using this system was to determine if VLPs assembled in a replication system specifically encapsidated viral RNA. Transcripts encoding the NwV capsid protein precursor (p70) were generated in yeast cells by replication of a hybrid RNA template by the Nodamura virus (NoV) replicase. Western analysis confirmed the presence of p70 as well as a protein of 62 kDa corresponding to the mature NwV capsid protein. Northern analysis of purified VLPs showed that NoV RNA1 and RNA3 were encapsidated, but no RNA2 was detected. Taken together, the data lead to the conclusion that specific encapsidation of tetraviral RNAs required more than close proximity of the viral RNAs and assembling virus-like particles. Encapsidation specificity in the omegatetraviruses may require additional viral proteins such as p17 during encapsidation or specific viral RNA encapsidation was replication-dependent. Replication-dependent assembly has been shown in the nodaviruses.
- Full Text:
- Date Issued: 2008
- Authors: Tomasicchio, Michele
- Date: 2008
- Subjects: Helicoverpa armigera Imbrasia cytherea Viruses RNA viruses Insects -- Viruses Lepidoptera -- Viruses Saccharomyces cerevisiae
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3930 , http://hdl.handle.net/10962/d1003989
- Description: The Tetraviridae are a family of ss (+) RNA viruses that specifically infect lepidopteran insects. Their icosahedral capsids are non-enveloped and approximately 40 nm in diameter with T=4 quasi-equivalent symmetry. The omegatetraviruses, which are structurally the best characterised in the family, include Helicoverpa armigera stunt virus (HaSV) and Nudaurelia capensis omega virus (NwV). The omegatetravirus procapsid is composed of 240 identical copies of the capsid precursor proteins, which undergo autoproteolytic cleavage at its carboxyl-terminus generating the mature capsid protein (b) and γ-peptide. This process occurs in vitro following a shift from pH 7.6 to pH 6.0. The viral capsid encapsidates two ss genomic RNAs: The larger RNA1 encodes the viral replicase as well as three small ORFs while RNA2 encodes the capsid precursor protein together with an overlapping ORF designated P17. While a wealth of structural data pertaining to the assembly and maturation of omegatetraviruses is available, little is known about how this relates to their lifecycle. The principle aim of the research described in this thesis was to use an experimental system developed in the yeast, Saccharomyces cerevisiae, to investigate the assembly of HaSV and NwV virus-like particles (VLPs) in terms of maturation and encapsidation of viral RNAs, in vivo. The yeast expression system used two promoter systems for expression of capsid precursor protein: in the first, a hybrid promoter (PGADH) was used for high-level expression, while the second, PGAL1, produced substantially lower levels of the virus capsid protein precursors. An increase in the level of HaSV capsid protein precursor (p71) via the PGADH promoter resulted in a dramatic increase in VLP assembly as compared with the PGAL system. A protein equivalent to the mature capsid protein (p64) appeared at later time intervals following induction of transcription. Transmission electron microscopic studies showed that p64 correlated with the presence of mature VLPs as opposed to procapsids in cells containing p71. This confirmed that the presence of p64 denoted maturation of VLPs in vivo. Further investigation indicated that maturation correlated with cell aging and the onset of apoptosis. It was shown that induction of apoptosis resulted in VLP maturation while inhibition of apoptosis prevented maturation. These results suggested that the process of apoptosis might be the trigger for maturation of virus procapsids in their host cells. The increase in the efficiency of VLP assembly observed in the high-level expression system was proposed to be due to an increase in the cellular concentrations of viral RNA. To test this hypothesis, HaSV P71 was co-expressed with either P71 mRNA or full length RNA2. An increase in the solubility of p71 was observed in cells expressing increased levels of both RNAs, but there was no increase in the efficiency of VLP assembly. Northern analysis of encapsidated RNAs revealed that there was no selective encapsidation of either P71 mRNA or viral RNA2. This data indicated that the increase in viral RNA was not the reason for increased efficiency of VLP assembly, but most likely resulted from higher concentrations of p71 itself. It was decided to determine whether a highly efficient nodavirus replication system developed in yeast for heterologous production of proteins, could be used as a method for expressing the capsid protein precursor. The aim of using this system was to determine if VLPs assembled in a replication system specifically encapsidated viral RNA. Transcripts encoding the NwV capsid protein precursor (p70) were generated in yeast cells by replication of a hybrid RNA template by the Nodamura virus (NoV) replicase. Western analysis confirmed the presence of p70 as well as a protein of 62 kDa corresponding to the mature NwV capsid protein. Northern analysis of purified VLPs showed that NoV RNA1 and RNA3 were encapsidated, but no RNA2 was detected. Taken together, the data lead to the conclusion that specific encapsidation of tetraviral RNAs required more than close proximity of the viral RNAs and assembling virus-like particles. Encapsidation specificity in the omegatetraviruses may require additional viral proteins such as p17 during encapsidation or specific viral RNA encapsidation was replication-dependent. Replication-dependent assembly has been shown in the nodaviruses.
- Full Text:
- Date Issued: 2008
Melatonin and anticancer therapy interactions with 5-Fluorouracil
- Authors: Cassim, Layla
- Date: 2008
- Subjects: Melatonin Melatonin -- Therapeutic use Antineoplastic agents Fluorouracil Fluorouracil -- Toxicology Cancer -- Treatment
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3746 , http://hdl.handle.net/10962/d1003224
- Description: On the basis of clinical studies, some researchers have advocated that the neurohormone and antioxidant melatonin, shown to possess intrinsic anticancer properties, be used as co-therapy in cancer patients being treated with the antineoplastic agent 5-fluorouracil, as increased patient survival times and enhanced quality of life have been observed. The focus of this research was thus to investigate the mechanisms of this seemingly beneficial drug interaction between 5-fluorouracil and melatonin. Metabolism studies were undertaken, in which it was established that there is no hepatic metabolic drug interaction between these agents by cytochrome P450, and that neither agent alters the activity of this enzyme system. Co-therapy with melatonin is thus unlikely to alter plasma levels of 5-fluorouracil by this mechanism. Novel mechanisms by which 5-fluorouracil is toxic were elucidated, such as the induction of lipid peroxidation, due to the formation of reactive oxygen species; decreases in brain serotonin, dopamine and norepinephrine levels, possibly leading to depression; hippocampal shrinkage and morphological alterations and lysis of hippocampal cells, which may underlie cognitive impairment; and a reduction in the nociceptive threshold when administered acutely. All these deleterious effects are attenuated by the co-administration of melatonin, suggesting that the agent exhibits antidepressive and analgesic properties, in addition to its known antioxidative and free radical-scavenging abilities. This suggests that melatonin cotherapy can significantly decrease 5-fluorouracil-induced toxicity, but this may also exert a protective effect on cancer cells and thus compromise the anticancer efficacy of 5-fluorouracil. It was, furthermore, found that stimulation of indoleamine 2,3-dioxygenase activity, mediated by increases in superoxide anion and interferon-γ levels, may underlie resistance to 5-fluorouracil therapy. Melatonin was shown to increase superoxide anion levels in vivo, and this is believed to be by conversion to the metabolite and known oxidant 6- hydroxymelatonin. This highlights that the possible deleterious effects of melatonin metabolites should be studied further. Serum corticosterone levels and cytokine profiles are unaltered by both 5-FU and melatonin, suggesting that these agents may be used by HIV infected individuals without promoting the progression to AIDS. It can thus be concluded that melatonin co-therapy is potentially useful in countering 5-fluorouracil toxicity.
- Full Text:
- Date Issued: 2008
- Authors: Cassim, Layla
- Date: 2008
- Subjects: Melatonin Melatonin -- Therapeutic use Antineoplastic agents Fluorouracil Fluorouracil -- Toxicology Cancer -- Treatment
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3746 , http://hdl.handle.net/10962/d1003224
- Description: On the basis of clinical studies, some researchers have advocated that the neurohormone and antioxidant melatonin, shown to possess intrinsic anticancer properties, be used as co-therapy in cancer patients being treated with the antineoplastic agent 5-fluorouracil, as increased patient survival times and enhanced quality of life have been observed. The focus of this research was thus to investigate the mechanisms of this seemingly beneficial drug interaction between 5-fluorouracil and melatonin. Metabolism studies were undertaken, in which it was established that there is no hepatic metabolic drug interaction between these agents by cytochrome P450, and that neither agent alters the activity of this enzyme system. Co-therapy with melatonin is thus unlikely to alter plasma levels of 5-fluorouracil by this mechanism. Novel mechanisms by which 5-fluorouracil is toxic were elucidated, such as the induction of lipid peroxidation, due to the formation of reactive oxygen species; decreases in brain serotonin, dopamine and norepinephrine levels, possibly leading to depression; hippocampal shrinkage and morphological alterations and lysis of hippocampal cells, which may underlie cognitive impairment; and a reduction in the nociceptive threshold when administered acutely. All these deleterious effects are attenuated by the co-administration of melatonin, suggesting that the agent exhibits antidepressive and analgesic properties, in addition to its known antioxidative and free radical-scavenging abilities. This suggests that melatonin cotherapy can significantly decrease 5-fluorouracil-induced toxicity, but this may also exert a protective effect on cancer cells and thus compromise the anticancer efficacy of 5-fluorouracil. It was, furthermore, found that stimulation of indoleamine 2,3-dioxygenase activity, mediated by increases in superoxide anion and interferon-γ levels, may underlie resistance to 5-fluorouracil therapy. Melatonin was shown to increase superoxide anion levels in vivo, and this is believed to be by conversion to the metabolite and known oxidant 6- hydroxymelatonin. This highlights that the possible deleterious effects of melatonin metabolites should be studied further. Serum corticosterone levels and cytokine profiles are unaltered by both 5-FU and melatonin, suggesting that these agents may be used by HIV infected individuals without promoting the progression to AIDS. It can thus be concluded that melatonin co-therapy is potentially useful in countering 5-fluorouracil toxicity.
- Full Text:
- Date Issued: 2008
South Africa and Malaysia: identity and history in South-South relations
- Authors: Haron, Muhammed
- Date: 2008
- Subjects: Critical theory South Africa -- Foreign relations -- Malaysia Malaysia -- Foreign relations -- South Africa South Africa -- Politics and government -- History Malaysia -- Politics and government -- History South Africa -- Politics and government Malaysia -- Politics and government South Africa -- Social conditions -- History Malaysia -- Social conditions -- History South Africa -- Economic conditions Malaysia -- Economic conditions
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2780 , http://hdl.handle.net/10962/d1002990
- Description: The focus of this thesis is on the bilateral relationship between South Africa and Malaysia. The thesis appropriates ‘critical theory,’ and as a flexible theoretical tool, and, as an open-ended, loose frame in order to give voice to the marginalized and voiceless from the South. The thesis thus looks at the politico-economic ties that have been developed and brings into view the socio-cultural relations that had been established between the peoples of the two sovereign nation-states during the apartheid and post-apartheid eras respectively. The basic purpose of this study was fivefold: (a) to contribute to the extant literature that concentrates on South Africa’s relations with Malaysia, (b) to examine the relationship at political and economic ties in some detail, (c) to demonstrate that apart from the afore-mentioned bonds IR specialists should also take into account the socio-cultural dimensions of international relations, (d) to bring to light the nation-state’s limitations when discussing the role of non-state actors and considering the contributions of other factors such as globalization, and (e) to stimulate further research on bilateral and multilateral relations in the South – particularly between South Africa and other states in Asia and Latin America - that would assist to better understand the past, present and perhaps the future.
- Full Text:
- Date Issued: 2008
- Authors: Haron, Muhammed
- Date: 2008
- Subjects: Critical theory South Africa -- Foreign relations -- Malaysia Malaysia -- Foreign relations -- South Africa South Africa -- Politics and government -- History Malaysia -- Politics and government -- History South Africa -- Politics and government Malaysia -- Politics and government South Africa -- Social conditions -- History Malaysia -- Social conditions -- History South Africa -- Economic conditions Malaysia -- Economic conditions
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2780 , http://hdl.handle.net/10962/d1002990
- Description: The focus of this thesis is on the bilateral relationship between South Africa and Malaysia. The thesis appropriates ‘critical theory,’ and as a flexible theoretical tool, and, as an open-ended, loose frame in order to give voice to the marginalized and voiceless from the South. The thesis thus looks at the politico-economic ties that have been developed and brings into view the socio-cultural relations that had been established between the peoples of the two sovereign nation-states during the apartheid and post-apartheid eras respectively. The basic purpose of this study was fivefold: (a) to contribute to the extant literature that concentrates on South Africa’s relations with Malaysia, (b) to examine the relationship at political and economic ties in some detail, (c) to demonstrate that apart from the afore-mentioned bonds IR specialists should also take into account the socio-cultural dimensions of international relations, (d) to bring to light the nation-state’s limitations when discussing the role of non-state actors and considering the contributions of other factors such as globalization, and (e) to stimulate further research on bilateral and multilateral relations in the South – particularly between South Africa and other states in Asia and Latin America - that would assist to better understand the past, present and perhaps the future.
- Full Text:
- Date Issued: 2008
Studies on the use of essential oils for the control of Sitophilus Zeamais (Motschulsky) (Coleoptera; Curculionidae): a pest of stored maize grains
- Odeyemi, Oluwakemi Oluwaseyi
- Authors: Odeyemi, Oluwakemi Oluwaseyi
- Date: 2008
- Subjects: Curculionidae , Essences and essential oils , Corn -- Diseases and pests -- South Africa , Biological pest control agents -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD (Botany)
- Identifier: vital:11301 , http://hdl.handle.net/10353/168 , Curculionidae , Essences and essential oils , Corn -- Diseases and pests -- South Africa , Biological pest control agents -- South Africa
- Description: The common maize weevil, Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae), a well known pest of stored-maize grain in most parts of the world, was identified as one of the major constraints of harvested maize grains in the Eastern Cape Province, South Africa. The use of plants or their products is one of the recent methods being investigated for insect pest control worldwide. Therefore, the main aim of the present study was to identify available plants in the Eastern Cape that could be used to combat the problem of Sitophilus zeamais in stored-maize grains. For the realization of the aims of this research, the following studies were carried out; a preliminary survey was conducted to obtain baseline information on the farmers’ knowledge and experience of indigenous insect pest control methods in the Eastern Cape. Also, studies on the insecticidal potential of the essential oils of some plants were investigated against the maize weevil. The quality parameters of maize grains treated with the essential oils was also studied and, using a rat model, the toxicity of the essential oils was investigated. The outcome from this study revealed that there is awareness amongst the farmers in the Eastern Cape on the use of plants or their products to control insect pests. Unfortunately, such methods are currently being neglected and the knowledge of their application was found to be eroding. Among the various essential oils screened were those from Mentha longifolia L. and Tagetes minuta L. which evoked an appreciable level of contact, fumigant and repellent toxicity on the maize weevil. Further work done to determine the effects of the oils on maize stored over a period of three months revealed that the two oils had no adverse effect on the proximate compositions and some quality parameters of the stored maize. However, the toxicological study conducted on rats showed that the oils at tested concentrations exhibited some level of toxicity. It is, therefore, suggested that the essential oils of M. longifolia and T. minuta should not be used to treat maize grains intended for human consumption.
- Full Text:
- Date Issued: 2008
- Authors: Odeyemi, Oluwakemi Oluwaseyi
- Date: 2008
- Subjects: Curculionidae , Essences and essential oils , Corn -- Diseases and pests -- South Africa , Biological pest control agents -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD (Botany)
- Identifier: vital:11301 , http://hdl.handle.net/10353/168 , Curculionidae , Essences and essential oils , Corn -- Diseases and pests -- South Africa , Biological pest control agents -- South Africa
- Description: The common maize weevil, Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae), a well known pest of stored-maize grain in most parts of the world, was identified as one of the major constraints of harvested maize grains in the Eastern Cape Province, South Africa. The use of plants or their products is one of the recent methods being investigated for insect pest control worldwide. Therefore, the main aim of the present study was to identify available plants in the Eastern Cape that could be used to combat the problem of Sitophilus zeamais in stored-maize grains. For the realization of the aims of this research, the following studies were carried out; a preliminary survey was conducted to obtain baseline information on the farmers’ knowledge and experience of indigenous insect pest control methods in the Eastern Cape. Also, studies on the insecticidal potential of the essential oils of some plants were investigated against the maize weevil. The quality parameters of maize grains treated with the essential oils was also studied and, using a rat model, the toxicity of the essential oils was investigated. The outcome from this study revealed that there is awareness amongst the farmers in the Eastern Cape on the use of plants or their products to control insect pests. Unfortunately, such methods are currently being neglected and the knowledge of their application was found to be eroding. Among the various essential oils screened were those from Mentha longifolia L. and Tagetes minuta L. which evoked an appreciable level of contact, fumigant and repellent toxicity on the maize weevil. Further work done to determine the effects of the oils on maize stored over a period of three months revealed that the two oils had no adverse effect on the proximate compositions and some quality parameters of the stored maize. However, the toxicological study conducted on rats showed that the oils at tested concentrations exhibited some level of toxicity. It is, therefore, suggested that the essential oils of M. longifolia and T. minuta should not be used to treat maize grains intended for human consumption.
- Full Text:
- Date Issued: 2008
Solar cycle effects on GNSS-derived ionospheric total electron content observed over Southern Africa
- Authors: Moeketsi, Daniel Mojalefa
- Date: 2008
- Subjects: Ionosphere -- Africa, Southern Electrons Ionospheric electron density -- Africa, Southern Ionosondes -- Africa, Southern Electromagnetic waves
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5489 , http://hdl.handle.net/10962/d1005275
- Description: The South African Global Navigation Satellite System (GNSS) network of dual frequency receivers provide an opportunity to investigate solar cycle effects on ionospheric Total Electron Content (TEC) over the South Africa region by taking advantage of the dispersive nature of the ionospheric medium. For this task, the global University of New Brunswick Ionospheric Modelling Technique (UNB-IMT) was adopted, modified and applied to compute TEC using data from the southern African GNSS Network. TEC values were compared with CODE International GNSS services TEC predictions and Ionosonde-derived TEC (ITEC) measurements to test and validate the UNB-IMT results over South Africa. It was found that the variation trends of GTEC and ITEC over all stations are in good agreement and show pronounced seasonal variations with high TEC values around equinoxes for a year near solar maximum and less pronounced around solar minimum. Signature TEC depletions and enhanced spikes were prevalently evident around equinoxes, particularly for a year near solar maximum. These observations were investigated and further discussed with an analysis of the midday Disturbance Storm Time (DST) index of geomagnetic activity. The residual GTEC – ITEC corresponding to plasmaspheric electron content and equivalent ionospheric foF2 and total slab thickness parameters were computed and comprehensively discussed. The results verified the use of UNB-IMT as one of the tools for ionospheric research over South Africa. The UNB-IMT algorithm was applied to investigate TEC variability during different epochs of solar cycle 23. The results were investigated and further discussed by analyzing the GOES 8 and 10 satellites X-ray flux (0.1 – 0.8 nm) and SOHO Solar Extreme Ultraviolet Monitor higher resolution data. Comparison of UNB-IMT TEC derived from collocated HRAO and HARB GNSS receivers was undertaken for the solar X17 and X9 flare events, which occurred on day 301, 2003 and day 339, 2006. It was found that there exist considerable TEC differences between the two collocated receivers with some evidence of solar cycle dependence. Furthermore, the daytime UNB TEC compared with the International Reference Ionosphere 2001 predicted TEC found both models to show a good agreement. The UNB-IMT TEC was further applied to investigate the capabilities of geodetic Very Long Baseline Interferometry (VLBI) derived TEC using the Vienna TEC Model for space weather monitoring over HartRAO during the CONT02 and CONT05 campaigns conducted during the years 2002 (near solar maximum) and 005 (near solar minimum). The results verified the use of geodetic VLBI as one of the possible instruments for monitoring space weather impacts on the ionosphere over South Africa.
- Full Text:
- Date Issued: 2008
Solar cycle effects on GNSS-derived ionospheric total electron content observed over Southern Africa
- Authors: Moeketsi, Daniel Mojalefa
- Date: 2008
- Subjects: Ionosphere -- Africa, Southern Electrons Ionospheric electron density -- Africa, Southern Ionosondes -- Africa, Southern Electromagnetic waves
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5489 , http://hdl.handle.net/10962/d1005275
- Description: The South African Global Navigation Satellite System (GNSS) network of dual frequency receivers provide an opportunity to investigate solar cycle effects on ionospheric Total Electron Content (TEC) over the South Africa region by taking advantage of the dispersive nature of the ionospheric medium. For this task, the global University of New Brunswick Ionospheric Modelling Technique (UNB-IMT) was adopted, modified and applied to compute TEC using data from the southern African GNSS Network. TEC values were compared with CODE International GNSS services TEC predictions and Ionosonde-derived TEC (ITEC) measurements to test and validate the UNB-IMT results over South Africa. It was found that the variation trends of GTEC and ITEC over all stations are in good agreement and show pronounced seasonal variations with high TEC values around equinoxes for a year near solar maximum and less pronounced around solar minimum. Signature TEC depletions and enhanced spikes were prevalently evident around equinoxes, particularly for a year near solar maximum. These observations were investigated and further discussed with an analysis of the midday Disturbance Storm Time (DST) index of geomagnetic activity. The residual GTEC – ITEC corresponding to plasmaspheric electron content and equivalent ionospheric foF2 and total slab thickness parameters were computed and comprehensively discussed. The results verified the use of UNB-IMT as one of the tools for ionospheric research over South Africa. The UNB-IMT algorithm was applied to investigate TEC variability during different epochs of solar cycle 23. The results were investigated and further discussed by analyzing the GOES 8 and 10 satellites X-ray flux (0.1 – 0.8 nm) and SOHO Solar Extreme Ultraviolet Monitor higher resolution data. Comparison of UNB-IMT TEC derived from collocated HRAO and HARB GNSS receivers was undertaken for the solar X17 and X9 flare events, which occurred on day 301, 2003 and day 339, 2006. It was found that there exist considerable TEC differences between the two collocated receivers with some evidence of solar cycle dependence. Furthermore, the daytime UNB TEC compared with the International Reference Ionosphere 2001 predicted TEC found both models to show a good agreement. The UNB-IMT TEC was further applied to investigate the capabilities of geodetic Very Long Baseline Interferometry (VLBI) derived TEC using the Vienna TEC Model for space weather monitoring over HartRAO during the CONT02 and CONT05 campaigns conducted during the years 2002 (near solar maximum) and 005 (near solar minimum). The results verified the use of geodetic VLBI as one of the possible instruments for monitoring space weather impacts on the ionosphere over South Africa.
- Full Text:
- Date Issued: 2008
South African public private partnership (PPP) projects
- Nyagwachi, Josiah Nyangaresi
- Authors: Nyagwachi, Josiah Nyangaresi
- Date: 2008
- Subjects: Public-private sector cooperation -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9696 , http://hdl.handle.net/10948/716 , Public-private sector cooperation -- South Africa
- Description: The purpose of this thesis is to disseminate research work done towards a higher degree and report on the findings of the research that was conducted relative to South African Public Private Partnership (PPP) projects. The research investigated perceptions of PPP actors on the performance of operational PPP projects. The aim of the research was to fulfil the requirements for the award of the degree of philosophiae doctor in construction management; contribute to the PPP body of knowledge; contribute further understanding of the performance of PPP projects in South Africa; and develop a systemic model for a sustainable PPP system within the country and beyond. All the aforementioned have been achieved, despite the research limitations as indicated in Chapter 1. A case study approach was adopted to examine various performance aspects of operational South African PPP projects. The research was a multi-case study design. Each individual case study consisted of a ‘whole’ study, in which facts were gathered from the selected PPP projects and conclusions drawn on those facts. A web-based questionnaire was used to capture the experiences and perceptions of various actors involved directly, or indirectly in selected PPP projects. The sample stratum consisted of all operational PPP projects registered in accordance with Treasury Regulations as of December 2005 and other projects that reached financial closure before the Public Finance Management Act of 1999 became effective. PPPs involve highly complex procurement processes, are relatively new in South Africa and to date have attracted limited investigation to refine our understanding of the operational performance of PPP projects. This is notable, as significant financial and other resources are involved, and the perception exists that service delivery in most parts of the country is poor. Key empirical evidence from the research indicates that South Africa has developed a robust policy and regulatory framework for PPPs; has an inadequate level of PPP awareness and training; and lacks the project management capacity to facilitate deal flow. It is suggested that further research be conducted on a yearly basis, preferably every six months, so that trends can be established concerning various aspects of other operational PPPs. Further, it is recommended that the PPP Unit commission sector-specific studies that will conduct further research, to compare research across PPP and non-PPP contracts. The choice to conduct a multi-case study required extensive resources and time beyond the means available to the researcher. Further, the sensitive nature of PPP projects made it difficult to obtain required data at the first attempt. However, the researcher made several follow up calls and reminders before eventually obtaining the required data from the respondents. A systemic PPP model has been developed for PPP implementation and management. This model was tested for appropriateness by conducting a further survey on PPP participants attending an international conference on 'Financing of Infrastructure Development in Africa through Public Private Partnerships’ staged in August 2007, in the St. George Hotel, Johannesburg, South Africa. The findings from this research make an invaluable and original contribution to the PPP body of knowledge, provide insight for further research in this important field, refine the understanding of operational PPP projects, and provide direction for policy and decision makers in the public and private sectors, within South Africa and beyond.
- Full Text:
- Date Issued: 2008
- Authors: Nyagwachi, Josiah Nyangaresi
- Date: 2008
- Subjects: Public-private sector cooperation -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9696 , http://hdl.handle.net/10948/716 , Public-private sector cooperation -- South Africa
- Description: The purpose of this thesis is to disseminate research work done towards a higher degree and report on the findings of the research that was conducted relative to South African Public Private Partnership (PPP) projects. The research investigated perceptions of PPP actors on the performance of operational PPP projects. The aim of the research was to fulfil the requirements for the award of the degree of philosophiae doctor in construction management; contribute to the PPP body of knowledge; contribute further understanding of the performance of PPP projects in South Africa; and develop a systemic model for a sustainable PPP system within the country and beyond. All the aforementioned have been achieved, despite the research limitations as indicated in Chapter 1. A case study approach was adopted to examine various performance aspects of operational South African PPP projects. The research was a multi-case study design. Each individual case study consisted of a ‘whole’ study, in which facts were gathered from the selected PPP projects and conclusions drawn on those facts. A web-based questionnaire was used to capture the experiences and perceptions of various actors involved directly, or indirectly in selected PPP projects. The sample stratum consisted of all operational PPP projects registered in accordance with Treasury Regulations as of December 2005 and other projects that reached financial closure before the Public Finance Management Act of 1999 became effective. PPPs involve highly complex procurement processes, are relatively new in South Africa and to date have attracted limited investigation to refine our understanding of the operational performance of PPP projects. This is notable, as significant financial and other resources are involved, and the perception exists that service delivery in most parts of the country is poor. Key empirical evidence from the research indicates that South Africa has developed a robust policy and regulatory framework for PPPs; has an inadequate level of PPP awareness and training; and lacks the project management capacity to facilitate deal flow. It is suggested that further research be conducted on a yearly basis, preferably every six months, so that trends can be established concerning various aspects of other operational PPPs. Further, it is recommended that the PPP Unit commission sector-specific studies that will conduct further research, to compare research across PPP and non-PPP contracts. The choice to conduct a multi-case study required extensive resources and time beyond the means available to the researcher. Further, the sensitive nature of PPP projects made it difficult to obtain required data at the first attempt. However, the researcher made several follow up calls and reminders before eventually obtaining the required data from the respondents. A systemic PPP model has been developed for PPP implementation and management. This model was tested for appropriateness by conducting a further survey on PPP participants attending an international conference on 'Financing of Infrastructure Development in Africa through Public Private Partnerships’ staged in August 2007, in the St. George Hotel, Johannesburg, South Africa. The findings from this research make an invaluable and original contribution to the PPP body of knowledge, provide insight for further research in this important field, refine the understanding of operational PPP projects, and provide direction for policy and decision makers in the public and private sectors, within South Africa and beyond.
- Full Text:
- Date Issued: 2008
Camphor derivatives in asymmetric synthesis: a synthetic, mechanistic and theoretical study
- Authors: Lobb, Kevin Alan
- Date: 2008
- Subjects: Chemistry, Organic -- Research Esters Organic compounds -- Synthesis Alkylation Chemical reactions -- Computer simulation Chemical kinetics Camphor Cinnamomum
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4414 , http://hdl.handle.net/10962/d1006770
- Description: A series of 3,3-ethylenedioxy-exo- and endo- bornyl esters have been prepared and subjected to α-benzylation using lithium diisopropylamide and benzyl bromide. In the exo-series of esters the diastereofacial selectivity of benzylation was found to improve (up to 34% d.e.) as the steric bulk of the O-alkyl group increased, whereas in the endo-series, a surprising decrease in stereoselectivity was observed as the steric bulk increased – an observation attributed to flexibility of the metal-coordinated endo-enolate system, compared to the relative rigidity of the exo analogues. The conformational options for each series was explored at the density functional theory level. Reductive cyclization of a range of specially prepared N-carbobenzyloxy-amino acid esters has been shown to afford the corresponding derivatives, contrary to previous reports that the cyclization is limited to the glycine derivative. The cyclization sequence has been explored in detail, and the yield has been shown to be critically dependent on the stereochemistry of the α-amino acid moiety. Moreover, it seems that reductive cyclization occurs more readily with the endo- rather than the exo-bornyl N-CBZ-amino acid esters. Molecular modelling of relevant transition states at the DFT levels indicates that L-amino acid-derived systems should cyclize preferably in the exo-series and D-amino acid-derived systems should cyclize preferably in the endo series. Studies of alkylation of an iminolactone system have reported an interesting anomaly - exo-methylation is observed while endo-alkylation predominates for larger alkyl groups. This has been studied in detail at the DFT level, and the anomaly is attributed to thermodynamic control in the methyl case, whereas kinetic control is the norm in this system. Preliminary computer modelling of the intramolecular rearrangement of a 3,3-xylylbornyl system at the HF/STO-3G level raised doubts concerning the structure assigned by Evans to one of the rearrangement products, prompting an X-ray crystallographic analysis and leading to the revision of its structure from a pinene to a camphene derivative. The previously elusive spiro[bornane-3,2’-indan]-2-exo-tosylate has been successfully isolated, and the kinetics of its ready decomposition to the two camphene products has been followed by 1H NMR spectroscopy. The endo-tosylate analogue, on the other hand, was found to be remarkably stable. Kinetic data obtained for rearrangement of this exo-bornyl tosylate have indicated the operation of tandem autocatalytic and pseudo-first-order transformations leading sequentially to the two isomeric camphene products. An extensive coset analysis of all possible rearrangement processes of the initially-formed cation formed from decomposition of the exo-tosylate has afforded a graph containing 336 classical cations (modelled at the AM1 and B3LYP levels) and 526 transition-state complexes (modelled at the AM1 level). This analysis afforded a viable 4-step classical mechanism connecting the first camphene product with the second. A more realistic study, involving non-classical carbocations, has afforded a graph of all possible (classical and non-classical) cations that could be formed by rearrangment of the initiallyformed cation. The resulting graph confirms that the only energetically feasible path corresponds to the classical mechanism, but simply involves two steps, including a novel, concerted Wagner-Meerwein – 6,2-hydride shift – Wagner-Meerwein rearrangement.
- Full Text:
- Date Issued: 2008
- Authors: Lobb, Kevin Alan
- Date: 2008
- Subjects: Chemistry, Organic -- Research Esters Organic compounds -- Synthesis Alkylation Chemical reactions -- Computer simulation Chemical kinetics Camphor Cinnamomum
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4414 , http://hdl.handle.net/10962/d1006770
- Description: A series of 3,3-ethylenedioxy-exo- and endo- bornyl esters have been prepared and subjected to α-benzylation using lithium diisopropylamide and benzyl bromide. In the exo-series of esters the diastereofacial selectivity of benzylation was found to improve (up to 34% d.e.) as the steric bulk of the O-alkyl group increased, whereas in the endo-series, a surprising decrease in stereoselectivity was observed as the steric bulk increased – an observation attributed to flexibility of the metal-coordinated endo-enolate system, compared to the relative rigidity of the exo analogues. The conformational options for each series was explored at the density functional theory level. Reductive cyclization of a range of specially prepared N-carbobenzyloxy-amino acid esters has been shown to afford the corresponding derivatives, contrary to previous reports that the cyclization is limited to the glycine derivative. The cyclization sequence has been explored in detail, and the yield has been shown to be critically dependent on the stereochemistry of the α-amino acid moiety. Moreover, it seems that reductive cyclization occurs more readily with the endo- rather than the exo-bornyl N-CBZ-amino acid esters. Molecular modelling of relevant transition states at the DFT levels indicates that L-amino acid-derived systems should cyclize preferably in the exo-series and D-amino acid-derived systems should cyclize preferably in the endo series. Studies of alkylation of an iminolactone system have reported an interesting anomaly - exo-methylation is observed while endo-alkylation predominates for larger alkyl groups. This has been studied in detail at the DFT level, and the anomaly is attributed to thermodynamic control in the methyl case, whereas kinetic control is the norm in this system. Preliminary computer modelling of the intramolecular rearrangement of a 3,3-xylylbornyl system at the HF/STO-3G level raised doubts concerning the structure assigned by Evans to one of the rearrangement products, prompting an X-ray crystallographic analysis and leading to the revision of its structure from a pinene to a camphene derivative. The previously elusive spiro[bornane-3,2’-indan]-2-exo-tosylate has been successfully isolated, and the kinetics of its ready decomposition to the two camphene products has been followed by 1H NMR spectroscopy. The endo-tosylate analogue, on the other hand, was found to be remarkably stable. Kinetic data obtained for rearrangement of this exo-bornyl tosylate have indicated the operation of tandem autocatalytic and pseudo-first-order transformations leading sequentially to the two isomeric camphene products. An extensive coset analysis of all possible rearrangement processes of the initially-formed cation formed from decomposition of the exo-tosylate has afforded a graph containing 336 classical cations (modelled at the AM1 and B3LYP levels) and 526 transition-state complexes (modelled at the AM1 level). This analysis afforded a viable 4-step classical mechanism connecting the first camphene product with the second. A more realistic study, involving non-classical carbocations, has afforded a graph of all possible (classical and non-classical) cations that could be formed by rearrangment of the initiallyformed cation. The resulting graph confirms that the only energetically feasible path corresponds to the classical mechanism, but simply involves two steps, including a novel, concerted Wagner-Meerwein – 6,2-hydride shift – Wagner-Meerwein rearrangement.
- Full Text:
- Date Issued: 2008
A holistic healthcare model for higher education campus health services
- Authors: Ricks, Esmeralda Jennifer
- Date: 2008
- Subjects: College students -- Health and hygiene -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DCur
- Identifier: vital:10038 , http://hdl.handle.net/10948/666 , College students -- Health and hygiene -- South Africa -- Eastern Cape
- Description: Most students are adolescents and young adults, a group characterized by a new-found sense of independence, experimentation with sex and sometimes drugs and a feeling of invincibility (Gayle, Richard, Keeling, Garcia-Tunon, Kilbourne, Narkunas, Ingram, rogers and Curran, 1990:1538). These behavioural, developmental and environmental issues may contribute to premature morbidity, mortality and reduced quality of life for university students (Patrick et al., 1992:260). The ages of staff on the other hand range from young adults to retirement age. The types of health problems that exist among staff who use the campus health service include First Aid treatment on site for injuries on duty and more chronic health problems such as, for example, hypertension and diabetes mellitus. To date there is very little evidence as to whether or not the healthcare needs of students and staff are being met comprehensively or whether the practitioners rendering the service are knowledgeable and complying with the PHC norms and standards developed by the department of Health’s Quality Assurance Directorate. The lack of such empirical data can contribute to misconceptions and hamper the management of public health problems experienced in SA, for example sexually transmitted infections and the transmission of HIV. Thus the purpose of this research was to develop a model that would assist registered nurses employed at a higher education campus health service in the Western Region of the Eastern Cape Province to render a healthcare service relevant to the healthcare needs of the students and staff on campus.
- Full Text:
- Date Issued: 2008
- Authors: Ricks, Esmeralda Jennifer
- Date: 2008
- Subjects: College students -- Health and hygiene -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DCur
- Identifier: vital:10038 , http://hdl.handle.net/10948/666 , College students -- Health and hygiene -- South Africa -- Eastern Cape
- Description: Most students are adolescents and young adults, a group characterized by a new-found sense of independence, experimentation with sex and sometimes drugs and a feeling of invincibility (Gayle, Richard, Keeling, Garcia-Tunon, Kilbourne, Narkunas, Ingram, rogers and Curran, 1990:1538). These behavioural, developmental and environmental issues may contribute to premature morbidity, mortality and reduced quality of life for university students (Patrick et al., 1992:260). The ages of staff on the other hand range from young adults to retirement age. The types of health problems that exist among staff who use the campus health service include First Aid treatment on site for injuries on duty and more chronic health problems such as, for example, hypertension and diabetes mellitus. To date there is very little evidence as to whether or not the healthcare needs of students and staff are being met comprehensively or whether the practitioners rendering the service are knowledgeable and complying with the PHC norms and standards developed by the department of Health’s Quality Assurance Directorate. The lack of such empirical data can contribute to misconceptions and hamper the management of public health problems experienced in SA, for example sexually transmitted infections and the transmission of HIV. Thus the purpose of this research was to develop a model that would assist registered nurses employed at a higher education campus health service in the Western Region of the Eastern Cape Province to render a healthcare service relevant to the healthcare needs of the students and staff on campus.
- Full Text:
- Date Issued: 2008
Managing conflict across cultures, values and identities: a case study in the South African automotive industry
- Authors: Mayer, Claude-Hélène
- Date: 2008
- Subjects: Conflict management -- South Africa Automobile industry and trade -- South Africa Automobile industry workers -- South Africa Communication in management -- South Africa Intercultural communication -- South Africa Culture conflict -- South Africa Diversity in the workplace -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1174 , http://hdl.handle.net/10962/d1002790
- Description: Over the past fifty years, interest in the field of conflict management and peacekeeping has developed worldwide. During the same time, the potential for trans-ultural) conflict has escalated. This can mainly be attributed to the trend towards globalisation, as well as the growing complexity of societies increasingly experiencing more intercultural encounters or cultural transition situations and work-related or organisational conflicts. Cultural transition situations occur in the South African international automotive industry where the emergence of international co-operation, such as joint ventures (driven by globalisation) and new diversity management trends, have changed the way business is conducted. Due to these changes, employees of diverse origins with different cultures, values and identities work together, experiencing work-related conflicts. The purpose of this study was to assess managerial perspectives on conflict, identity and values, as well as on how (trans-cultural) conflict is managed in a selected international organisation in the South African automotive industry. The contribution of this study is twofold, namely to increase the understanding of the complexities of conflict in organisations; and to provide recommendations for conflict resolution strategies to manage (trans-cultural) conflict constructively by considering the values and identity aspects of those individuals involved. This study comprises a single explanatory case study which made use of qualitative data collection and analysis to investigate managerial perspectives on conflict, identity and values, as well as the management thereof, in the selected international organisation in the South African automotive context. Based on the main findings from this case study, it could be concluded that managers with diverse backgrounds experience work-related conflicts which are related to value and identity concepts in the selected organisation. The conflicts experienced fell into the categories of Communication and Treatment, Position and Competition, Organisation and Race and Gender.An overview of the occurrence frequency of value statements revealed that equality, communication and respect were the most commonly indicated values in conflicts. These value concepts include sub-concepts such as: · for equality: race, gender and human equality; · for communication: open, personal, free, decent, calm and proactive communication; and · for respect: mutual respect for self and others. With regard to value concepts and according to value domains of Schwartz (1994) and Schwartz and Bilsky (1987), the value dimensions of selftranscendence comprised the highest number of value statements. This dimension included the value domains of universalism and benevolence. Conflict in the data material was interlinked with identity. The extracts, based on the key words of the identity factors, demonstrated that the identity factors were related to either a weakening or strengthening effect on identities. Social and identity multiplicity in managers provides creativity spaces and flexibility in cases of strong identity patterns. Particularly with weak identities, the existence of conflict potentials could lead to complex conflicts and challenges in conflict management. Communication was most often mentioned as important to successful conflict resolution management and included examples such as round-table talks, smooth communication, face-to-face communication and room meetings. Communication was followed in frequency by strategies of internal intervention, which included the use of the formal structure of the organisation to resolve conflicts.
- Full Text:
- Date Issued: 2008
- Authors: Mayer, Claude-Hélène
- Date: 2008
- Subjects: Conflict management -- South Africa Automobile industry and trade -- South Africa Automobile industry workers -- South Africa Communication in management -- South Africa Intercultural communication -- South Africa Culture conflict -- South Africa Diversity in the workplace -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1174 , http://hdl.handle.net/10962/d1002790
- Description: Over the past fifty years, interest in the field of conflict management and peacekeeping has developed worldwide. During the same time, the potential for trans-ultural) conflict has escalated. This can mainly be attributed to the trend towards globalisation, as well as the growing complexity of societies increasingly experiencing more intercultural encounters or cultural transition situations and work-related or organisational conflicts. Cultural transition situations occur in the South African international automotive industry where the emergence of international co-operation, such as joint ventures (driven by globalisation) and new diversity management trends, have changed the way business is conducted. Due to these changes, employees of diverse origins with different cultures, values and identities work together, experiencing work-related conflicts. The purpose of this study was to assess managerial perspectives on conflict, identity and values, as well as on how (trans-cultural) conflict is managed in a selected international organisation in the South African automotive industry. The contribution of this study is twofold, namely to increase the understanding of the complexities of conflict in organisations; and to provide recommendations for conflict resolution strategies to manage (trans-cultural) conflict constructively by considering the values and identity aspects of those individuals involved. This study comprises a single explanatory case study which made use of qualitative data collection and analysis to investigate managerial perspectives on conflict, identity and values, as well as the management thereof, in the selected international organisation in the South African automotive context. Based on the main findings from this case study, it could be concluded that managers with diverse backgrounds experience work-related conflicts which are related to value and identity concepts in the selected organisation. The conflicts experienced fell into the categories of Communication and Treatment, Position and Competition, Organisation and Race and Gender.An overview of the occurrence frequency of value statements revealed that equality, communication and respect were the most commonly indicated values in conflicts. These value concepts include sub-concepts such as: · for equality: race, gender and human equality; · for communication: open, personal, free, decent, calm and proactive communication; and · for respect: mutual respect for self and others. With regard to value concepts and according to value domains of Schwartz (1994) and Schwartz and Bilsky (1987), the value dimensions of selftranscendence comprised the highest number of value statements. This dimension included the value domains of universalism and benevolence. Conflict in the data material was interlinked with identity. The extracts, based on the key words of the identity factors, demonstrated that the identity factors were related to either a weakening or strengthening effect on identities. Social and identity multiplicity in managers provides creativity spaces and flexibility in cases of strong identity patterns. Particularly with weak identities, the existence of conflict potentials could lead to complex conflicts and challenges in conflict management. Communication was most often mentioned as important to successful conflict resolution management and included examples such as round-table talks, smooth communication, face-to-face communication and room meetings. Communication was followed in frequency by strategies of internal intervention, which included the use of the formal structure of the organisation to resolve conflicts.
- Full Text:
- Date Issued: 2008