Biological responses to a resumption in river flow in a freshwater-deprived, permanently open Southern African estuary
- Vorwerk, Paul D, Froneman, P William, Paterson, Angus W, Strydom, Nadine A, Whitfield, Alan K
- Authors: Vorwerk, Paul D , Froneman, P William , Paterson, Angus W , Strydom, Nadine A , Whitfield, Alan K
- Date: 2008
- Language: English
- Type: text , Article
- Identifier: vital:6886 , http://hdl.handle.net/10962/d1011645
- Description: The Kariega Estuary is a freshwater-deprived system due to numerous impoundments in the catchment. This system has had little or no horizontal salinity gradient over the last 15 years, with hypersaline conditions sometimes predominating in the upper reaches. Following high rainfall events in the catchment during the spring of 2006, including a flood event (approximate 1:10 year) in August 2006, a series of riverine pulses entered the estuary and a horizontal salinity gradient was established. This study examined the influence of this freshwater pulse on four components of the biota within the estuary, namely the zooplankton, and larval, littoral and demersal fishes. The study demonstrated that in three of these components elevated densities were recorded following the riverine input, with only the littoral fishes retaining an almost constant density. In addition, changes in the relative contributions of the estuarine utilisation classes for all three fish groups examined indicated that freshwater input into these systems positively influences the abundances. This has significant implications for water managers as it demonstrates the importance of an Ecological Reserve (defined as ‘the water required to protect the aquatic ecosystems of the water resource’) for this system.
- Full Text:
- Date Issued: 2008
- Authors: Vorwerk, Paul D , Froneman, P William , Paterson, Angus W , Strydom, Nadine A , Whitfield, Alan K
- Date: 2008
- Language: English
- Type: text , Article
- Identifier: vital:6886 , http://hdl.handle.net/10962/d1011645
- Description: The Kariega Estuary is a freshwater-deprived system due to numerous impoundments in the catchment. This system has had little or no horizontal salinity gradient over the last 15 years, with hypersaline conditions sometimes predominating in the upper reaches. Following high rainfall events in the catchment during the spring of 2006, including a flood event (approximate 1:10 year) in August 2006, a series of riverine pulses entered the estuary and a horizontal salinity gradient was established. This study examined the influence of this freshwater pulse on four components of the biota within the estuary, namely the zooplankton, and larval, littoral and demersal fishes. The study demonstrated that in three of these components elevated densities were recorded following the riverine input, with only the littoral fishes retaining an almost constant density. In addition, changes in the relative contributions of the estuarine utilisation classes for all three fish groups examined indicated that freshwater input into these systems positively influences the abundances. This has significant implications for water managers as it demonstrates the importance of an Ecological Reserve (defined as ‘the water required to protect the aquatic ecosystems of the water resource’) for this system.
- Full Text:
- Date Issued: 2008
Bioprocess development for removal of nitrogenous compounds from precious metal refinery wastewater
- Manipura, Walappuly Mudiyanselage Janakasiri Aruna Shantha Bandara
- Authors: Manipura, Walappuly Mudiyanselage Janakasiri Aruna Shantha Bandara
- Date: 2008
- Subjects: Factory and trade waste Centralized industrial waste treatment facilities Metals -- Absorption and adsorption Metals -- Environmental aspects Water -- Purification -- Mathematical models Water quality management Water reuse Metals -- Refining Microbiology -- Research
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4076 , http://hdl.handle.net/10962/d1007341
- Description: Removal of nitrogenous compounds from precious metal refinery (PMR) wastewater is important in terms of avoiding eutrophication (environmental protection), metal recovery (increased overall process efficiency and value recovery) and reuse of treated water (maximum use of natural resources). Extreme pH conditions (4 to 13 depending on the wastewater stream), high chemical oxygen demand (> 10,000 mg/I), numerous metals and high concentrations of those metals (> 20 mg/l of platinum group metals) in the wastewater are the main challenges for biological removal of nitrogenous compounds from PMR wastewater. Nitrogenous compounds such as NH₄⁺-N and N0₃-N are strong metal ligands, which make it difficult to recover metals from the wastewater. Therefore, a bioprocess was developed for removal of nitrogenous compounds from carefully simulated PMR wastewater. A preliminary investigation of metal wastewater was carried out to determine its composition and physico-chemical properties, the ability to nitrify and denitrify under different pH conditions and denitrification with different carbon Source compounds and amounts. Even at pH 4, nitrification could be carried out. A suitable hydraulic retention time was found to be 72 hours. There was no significant difference between sodium acetate and sodium lactate as carbon sources for denitrification. Based on these results, a reactor comparison study was carried out using simulated PMR wastewater in three types of reactors: continuously stirred tank reactor (CSTR), packed-bed reactor (PBR) and airlift suspension reactor (ALSR). These reactors were fed with 30 mg/l of Rh bound in an NH₄⁺ based compound (Claus salt: pentaaminechlororhodium (III) dichloride). Total nitrogen removal efficiencies of > 68 % , > 79 % and > 45 % were obtained in the CSTR, PBR and ALSR, respectively. Serially connected CSTR-PBR and PBR-CSTR reactor configurations were then studied to determine the best configuration for maximum removal of nitrogenous compounds from the wastewater. The PBR-CSTR configuration gave consistent biomass retention and automatic pH control in the CSTR. Ammonium removal efficiencies > 95 % were achieved in both reactors. As poor nitrate removal was observed a toxicity study was carried out using respirometry and the half saturation inhibition coefficients for Pt, Pd, Rh and Ru were found to be 15.81, 25.00, 33.34 and 39.25 mg/l, respectively. A mathematical model was developed to describe the nitrogen removal in PMR wastewater using activated sludge model number 1 (ASMl), two step nitrification and metal toxicity. An operational protocol was developed based on the literature review, experimental work and simulation results. The optimum reactor configuration under the set conditions (20 mg/I of Rh and < 100 mg/I of NH₄⁺-N) was found to be PBR-CSTR-PBR process, which achieved overall NH₄⁺-N and N0₃⁻-N removal efficiencies of > 90 % and 95 %, respectively. Finally, a rudimentary microbial characterisation was carried out on subsamples from the CSTR and PBRsecondary. It was found that the CSTR biomass consisted of both rods and cocci while PBRsecondary consisted of rods only. Based on these experimental works, further research needs and recommendations were made for optimisation of the developed bioprocess for removal of nitrogenous compounds from PMR wastewater.
- Full Text:
- Date Issued: 2008
- Authors: Manipura, Walappuly Mudiyanselage Janakasiri Aruna Shantha Bandara
- Date: 2008
- Subjects: Factory and trade waste Centralized industrial waste treatment facilities Metals -- Absorption and adsorption Metals -- Environmental aspects Water -- Purification -- Mathematical models Water quality management Water reuse Metals -- Refining Microbiology -- Research
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4076 , http://hdl.handle.net/10962/d1007341
- Description: Removal of nitrogenous compounds from precious metal refinery (PMR) wastewater is important in terms of avoiding eutrophication (environmental protection), metal recovery (increased overall process efficiency and value recovery) and reuse of treated water (maximum use of natural resources). Extreme pH conditions (4 to 13 depending on the wastewater stream), high chemical oxygen demand (> 10,000 mg/I), numerous metals and high concentrations of those metals (> 20 mg/l of platinum group metals) in the wastewater are the main challenges for biological removal of nitrogenous compounds from PMR wastewater. Nitrogenous compounds such as NH₄⁺-N and N0₃-N are strong metal ligands, which make it difficult to recover metals from the wastewater. Therefore, a bioprocess was developed for removal of nitrogenous compounds from carefully simulated PMR wastewater. A preliminary investigation of metal wastewater was carried out to determine its composition and physico-chemical properties, the ability to nitrify and denitrify under different pH conditions and denitrification with different carbon Source compounds and amounts. Even at pH 4, nitrification could be carried out. A suitable hydraulic retention time was found to be 72 hours. There was no significant difference between sodium acetate and sodium lactate as carbon sources for denitrification. Based on these results, a reactor comparison study was carried out using simulated PMR wastewater in three types of reactors: continuously stirred tank reactor (CSTR), packed-bed reactor (PBR) and airlift suspension reactor (ALSR). These reactors were fed with 30 mg/l of Rh bound in an NH₄⁺ based compound (Claus salt: pentaaminechlororhodium (III) dichloride). Total nitrogen removal efficiencies of > 68 % , > 79 % and > 45 % were obtained in the CSTR, PBR and ALSR, respectively. Serially connected CSTR-PBR and PBR-CSTR reactor configurations were then studied to determine the best configuration for maximum removal of nitrogenous compounds from the wastewater. The PBR-CSTR configuration gave consistent biomass retention and automatic pH control in the CSTR. Ammonium removal efficiencies > 95 % were achieved in both reactors. As poor nitrate removal was observed a toxicity study was carried out using respirometry and the half saturation inhibition coefficients for Pt, Pd, Rh and Ru were found to be 15.81, 25.00, 33.34 and 39.25 mg/l, respectively. A mathematical model was developed to describe the nitrogen removal in PMR wastewater using activated sludge model number 1 (ASMl), two step nitrification and metal toxicity. An operational protocol was developed based on the literature review, experimental work and simulation results. The optimum reactor configuration under the set conditions (20 mg/I of Rh and < 100 mg/I of NH₄⁺-N) was found to be PBR-CSTR-PBR process, which achieved overall NH₄⁺-N and N0₃⁻-N removal efficiencies of > 90 % and 95 %, respectively. Finally, a rudimentary microbial characterisation was carried out on subsamples from the CSTR and PBRsecondary. It was found that the CSTR biomass consisted of both rods and cocci while PBRsecondary consisted of rods only. Based on these experimental works, further research needs and recommendations were made for optimisation of the developed bioprocess for removal of nitrogenous compounds from PMR wastewater.
- Full Text:
- Date Issued: 2008
Biosorption of precious metals from synthetic and refinery wastewaters by immobilized saccharomyces cerevisiae
- Authors: Mack, Cherie-Lynn
- Date: 2008
- Subjects: Metals -- Refining Metals -- Absorption and adsorption Saccharomyces cerevisiae Factory and trade waste Water reuse Platinum
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4071 , http://hdl.handle.net/10962/d1006977
- Description: The process of precious metal refining can be up to 99.99% efficient at best, and although it may seem small, the amount of valuable metal lost to waste streams is appreciable enough to warrant recovery. The method currently used to remove entrained metal ions from refinery wastewaters, chemical precipitation, is not an effective means for selective recovery of precious metals from a wastewater. Biosorption, the ability of certain types of biomass to bind and concentrate metals from even very dilute aqueous solutions, may be an effective point-source metal recovery strategy. The yeast, Saccharomyces cerevisiae, has been found capable of sorbing numerous precious and base metals, and is a cheap and abundant source of biomass. As such, it represents a possible precious metal sorbent for application to refining wastewaters. In this investigation, S. cerevisiae biomass was immobilized, using polyethyleneimine and glutaraldehyde, to produce a suitable sorbent, which was found to be capable of high platinum uptake (150 to 170 mg/g) at low pH (< 2). The sorption mechanism was elucidated and found to be a chemical reaction, which made effective desorption impossible. The sorption process was investigated in a packed bed column conformation, the results of which showed that the diameter and height of the column require further optimization in order to attain the metal uptake values achieved in the batch studies. When applied to a refinery wastewater, two key wastewater characteristics limited the success of the sorption process; the high inorganic ion content and the complex speciation of the platinum ions. The results proved the concept principle of platinum recovery by immobilized yeast biosorption and indicated that a more detailed understanding of the platinum speciation within the wastewater is required before the biosorption process can be applied. Overall, the sorption of platinum by the S. cerevisiae sorbent was demonstrated to be highly effective in principle, but the complexity of the wastewater requires that pretreatment steps be taken before the successful application of this process to an industrial wastewater.
- Full Text:
- Date Issued: 2008
- Authors: Mack, Cherie-Lynn
- Date: 2008
- Subjects: Metals -- Refining Metals -- Absorption and adsorption Saccharomyces cerevisiae Factory and trade waste Water reuse Platinum
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4071 , http://hdl.handle.net/10962/d1006977
- Description: The process of precious metal refining can be up to 99.99% efficient at best, and although it may seem small, the amount of valuable metal lost to waste streams is appreciable enough to warrant recovery. The method currently used to remove entrained metal ions from refinery wastewaters, chemical precipitation, is not an effective means for selective recovery of precious metals from a wastewater. Biosorption, the ability of certain types of biomass to bind and concentrate metals from even very dilute aqueous solutions, may be an effective point-source metal recovery strategy. The yeast, Saccharomyces cerevisiae, has been found capable of sorbing numerous precious and base metals, and is a cheap and abundant source of biomass. As such, it represents a possible precious metal sorbent for application to refining wastewaters. In this investigation, S. cerevisiae biomass was immobilized, using polyethyleneimine and glutaraldehyde, to produce a suitable sorbent, which was found to be capable of high platinum uptake (150 to 170 mg/g) at low pH (< 2). The sorption mechanism was elucidated and found to be a chemical reaction, which made effective desorption impossible. The sorption process was investigated in a packed bed column conformation, the results of which showed that the diameter and height of the column require further optimization in order to attain the metal uptake values achieved in the batch studies. When applied to a refinery wastewater, two key wastewater characteristics limited the success of the sorption process; the high inorganic ion content and the complex speciation of the platinum ions. The results proved the concept principle of platinum recovery by immobilized yeast biosorption and indicated that a more detailed understanding of the platinum speciation within the wastewater is required before the biosorption process can be applied. Overall, the sorption of platinum by the S. cerevisiae sorbent was demonstrated to be highly effective in principle, but the complexity of the wastewater requires that pretreatment steps be taken before the successful application of this process to an industrial wastewater.
- Full Text:
- Date Issued: 2008
Black parental involvement in education
- Authors: Mbokodi, Sindiswa Madgie
- Date: 2008
- Subjects: Education -- Parent participation -- South Africa , Parent-teacher relationships -- South Africa
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: vital:9518 , http://hdl.handle.net/10948/1013 , Education -- Parent participation -- South Africa , Parent-teacher relationships -- South Africa
- Description: The study was conducted in the backdrop of Section 24(1)(a) of the South African Schools Act (SASA) 84 of 1996 which promulgated that parents should be involved in the education of their children. To fulfil this requirement, each school is expected to have a legally constituted School Governing Body (SGB) as part of school governance. The involvement of the SGB does not exclude parents involving themselves in school activities as individuals but as organised groups geared towards working on a specific project of the school. Involvement also implies helping the child at home. The study investigated the extent to which black parents involve themselves in school activities as envisaged by the SASA. Conceptual literature relating to issues of parental involvement in school was reviewed. Specifically the concept parent/parental involvement as it relates to black parents was explored. Factors promoting or hindering parental involvement in school were also examined. The research is qualitative. Participants included principals, teachers, learners and chairpersons of school governing bodies of ten selected schools in the major townships of Port Elizabeth. Views and experiences of participants were captured and explained through in-depth interviews and observations. Results are discussed in relation to the relevant literature, allowing grounded theory to emerge. What emerged was a desperate situation of non-involvement of black parents in school activities largely because of the failure of the Department of Education (DoE) to capacitate all parties involved in strategies to involve parents in school. The potential for generalizability and transferability is discussed in the report and possible intervention strategies are recommended at micro- and macro-levels. The study demonstrates that the DoE needs to follow up on its policies to ensure that the envisaged change is realized.
- Full Text:
- Date Issued: 2008
- Authors: Mbokodi, Sindiswa Madgie
- Date: 2008
- Subjects: Education -- Parent participation -- South Africa , Parent-teacher relationships -- South Africa
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: vital:9518 , http://hdl.handle.net/10948/1013 , Education -- Parent participation -- South Africa , Parent-teacher relationships -- South Africa
- Description: The study was conducted in the backdrop of Section 24(1)(a) of the South African Schools Act (SASA) 84 of 1996 which promulgated that parents should be involved in the education of their children. To fulfil this requirement, each school is expected to have a legally constituted School Governing Body (SGB) as part of school governance. The involvement of the SGB does not exclude parents involving themselves in school activities as individuals but as organised groups geared towards working on a specific project of the school. Involvement also implies helping the child at home. The study investigated the extent to which black parents involve themselves in school activities as envisaged by the SASA. Conceptual literature relating to issues of parental involvement in school was reviewed. Specifically the concept parent/parental involvement as it relates to black parents was explored. Factors promoting or hindering parental involvement in school were also examined. The research is qualitative. Participants included principals, teachers, learners and chairpersons of school governing bodies of ten selected schools in the major townships of Port Elizabeth. Views and experiences of participants were captured and explained through in-depth interviews and observations. Results are discussed in relation to the relevant literature, allowing grounded theory to emerge. What emerged was a desperate situation of non-involvement of black parents in school activities largely because of the failure of the Department of Education (DoE) to capacitate all parties involved in strategies to involve parents in school. The potential for generalizability and transferability is discussed in the report and possible intervention strategies are recommended at micro- and macro-levels. The study demonstrates that the DoE needs to follow up on its policies to ensure that the envisaged change is realized.
- Full Text:
- Date Issued: 2008
Breaking into the conversation: cultural value and the role of the South African National Arts Festival from apartheid to democracy
- Snowball, Jeanette D, Webb, Arthur C M
- Authors: Snowball, Jeanette D , Webb, Arthur C M
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71311 , vital:29832 , https://doi.org/10.1080/10286630802106326
- Description: The paper examines the value of the South African National Arts Festival (NAF) in the transition to democracy using theories of cultural capital. NAF history from 1974 to 2004 is used to argue that the Festival provided an important arena for the expression of political resistance in the 1980s and, to some degree, continues to do so today. It is concluded that an important part of the value of the arts is their ability to provide a forum for debating the goals and values of society and that individualistic utility theory is not always successful in measuring such social value.
- Full Text:
- Date Issued: 2008
- Authors: Snowball, Jeanette D , Webb, Arthur C M
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71311 , vital:29832 , https://doi.org/10.1080/10286630802106326
- Description: The paper examines the value of the South African National Arts Festival (NAF) in the transition to democracy using theories of cultural capital. NAF history from 1974 to 2004 is used to argue that the Festival provided an important arena for the expression of political resistance in the 1980s and, to some degree, continues to do so today. It is concluded that an important part of the value of the arts is their ability to provide a forum for debating the goals and values of society and that individualistic utility theory is not always successful in measuring such social value.
- Full Text:
- Date Issued: 2008
Building and Woodworkers International (BWI) Baseline gender survey
- Authors: Benjamin, Nina
- Date: 2008
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/60109 , vital:27737
- Description: This Gender Survey is about exploring both the nature of as well as the shifts in the gender relations between men women in the construction sector. The report is defining gender relations as the power relations between men and women. In the context of the construction sector, workers and particularly semi and unskilled workers generally have appalling working conditions. These conditions affect both men and women workers but the vast majority of women workers find themselves right at the bottom of a hierarchy that is shaped by class, race and gender. Large multinational construction companies are still owned and controlled by rich white men while black women, youth and the disabled find themselves right at the bottom of the hierarchy.
- Full Text:
- Date Issued: 2008
- Authors: Benjamin, Nina
- Date: 2008
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/60109 , vital:27737
- Description: This Gender Survey is about exploring both the nature of as well as the shifts in the gender relations between men women in the construction sector. The report is defining gender relations as the power relations between men and women. In the context of the construction sector, workers and particularly semi and unskilled workers generally have appalling working conditions. These conditions affect both men and women workers but the vast majority of women workers find themselves right at the bottom of a hierarchy that is shaped by class, race and gender. Large multinational construction companies are still owned and controlled by rich white men while black women, youth and the disabled find themselves right at the bottom of the hierarchy.
- Full Text:
- Date Issued: 2008
Bushclumps as refugia for small mammals in two Eastern Cape conservation areas
- Whittington-Jones, Gareth M, Bernard, Ric T F, Parker, Daniel M
- Authors: Whittington-Jones, Gareth M , Bernard, Ric T F , Parker, Daniel M
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/446975 , vital:74574 , https://hdl.handle.net/10520/EJC18077
- Description: Bushclumps are scattered islands of thicket-like vegetation within a matrix of more open vegetation. We investigated the role of bushclumps as refugia for small mammals, and examined the effect of a limited number of abiotic and biotic factors on their richness, diversity and abundance. Small mammals were surveyed using Sherman small mammal traps at two sites in the Eastern Cape Province, South Africa (Mountain Zebra National Park and Kwandwe Private Game Reserve). Soil hardness and seed abundance, inside and outside bushclumps, were determined. Trap success was significantly higher inside bushclumps than in areas outside, and species diversity and the abundance of small mammals were greater within bushclumps compared to outside. Bushclumps also had significantly softer soil and a higher concentration of seeds. We conclude that bushclumps provide a concentrated source of food and protection from predators for small mammals, and are thus used significantly more than adjacent open areas. The conservation of bushclumps is therefore important for the overall maintenance of ecosystem functioning.
- Full Text:
- Date Issued: 2008
- Authors: Whittington-Jones, Gareth M , Bernard, Ric T F , Parker, Daniel M
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/446975 , vital:74574 , https://hdl.handle.net/10520/EJC18077
- Description: Bushclumps are scattered islands of thicket-like vegetation within a matrix of more open vegetation. We investigated the role of bushclumps as refugia for small mammals, and examined the effect of a limited number of abiotic and biotic factors on their richness, diversity and abundance. Small mammals were surveyed using Sherman small mammal traps at two sites in the Eastern Cape Province, South Africa (Mountain Zebra National Park and Kwandwe Private Game Reserve). Soil hardness and seed abundance, inside and outside bushclumps, were determined. Trap success was significantly higher inside bushclumps than in areas outside, and species diversity and the abundance of small mammals were greater within bushclumps compared to outside. Bushclumps also had significantly softer soil and a higher concentration of seeds. We conclude that bushclumps provide a concentrated source of food and protection from predators for small mammals, and are thus used significantly more than adjacent open areas. The conservation of bushclumps is therefore important for the overall maintenance of ecosystem functioning.
- Full Text:
- Date Issued: 2008
Business process security maturity: a paradigm convergence
- Authors: Box, Debra
- Date: 2008
- Subjects: Management information systems , Reengineering (Management) , Organizational change , Systems engineering , Information resources management
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9785 , http://hdl.handle.net/10948/722 , Management information systems , Reengineering (Management) , Organizational change , Systems engineering , Information resources management
- Description: Information technology developments in software and hardware have enabled radical changes in information systems, culminating in the paradigm Business Process Management. There has been a concomitant rise in the importance of information security and security engineering due to the increased reliance by society on information. Information is seen as a critical success factor which needs protection. Information security is the response to increased hazards created through recent innovations in Web technology and the advent of intra and inter enterprise-wide systems. Security engineering is based on a variety of codes of practice and security metrics which aim at ameliorating these increased security hazards. Its aim is to produce a balanced set of security needs which are integrated into the system activities to establish confidence in the effectiveness of the security counter-measures. It is generally accepted that security should be applied in an integrated approach, for example, in Information Systems development. This has proved to be a noble thought but is the exception to the rule. Security, historically, is generally applied as an after-thought in an Information Technology implementation. This motivated the concept of formulating a model of integrating security inherently within the paradigm of BPM. The overarching requirements of the model are to align the overall organisational security initiatives and ensure continuous improvement through constant evaluation and adaptation of the security processes. It is the intention of this research to show that these requirements are achievable through aligning the process management methodology of BPM, with the security paradigms of Information Security Management (using the ISO 17799 standard) and security engineering (using the Systems Security Engineering Capability Maturity Model – SSE-CMM). The aim of the Business Process Security Maturity model as the output of this research, is to link the SSE-CMM, as the security metric and appraisal method, to the ISO 17799 security standard, which provides the guidance for the information security management framework and security control selection, within the Business Process Management environment. The SSE-CMM, as the security version of the Capability Maturity Model, provides the necessary strategy to control the security engineering processes that support the information systems and it maintains that as processes mature they become more predictable, effective and manageable. The aim of the model is to provide an integrated, mature security strategy within the business process and monitor and correct the security posture of the implemented counter-measures.
- Full Text:
- Date Issued: 2008
- Authors: Box, Debra
- Date: 2008
- Subjects: Management information systems , Reengineering (Management) , Organizational change , Systems engineering , Information resources management
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9785 , http://hdl.handle.net/10948/722 , Management information systems , Reengineering (Management) , Organizational change , Systems engineering , Information resources management
- Description: Information technology developments in software and hardware have enabled radical changes in information systems, culminating in the paradigm Business Process Management. There has been a concomitant rise in the importance of information security and security engineering due to the increased reliance by society on information. Information is seen as a critical success factor which needs protection. Information security is the response to increased hazards created through recent innovations in Web technology and the advent of intra and inter enterprise-wide systems. Security engineering is based on a variety of codes of practice and security metrics which aim at ameliorating these increased security hazards. Its aim is to produce a balanced set of security needs which are integrated into the system activities to establish confidence in the effectiveness of the security counter-measures. It is generally accepted that security should be applied in an integrated approach, for example, in Information Systems development. This has proved to be a noble thought but is the exception to the rule. Security, historically, is generally applied as an after-thought in an Information Technology implementation. This motivated the concept of formulating a model of integrating security inherently within the paradigm of BPM. The overarching requirements of the model are to align the overall organisational security initiatives and ensure continuous improvement through constant evaluation and adaptation of the security processes. It is the intention of this research to show that these requirements are achievable through aligning the process management methodology of BPM, with the security paradigms of Information Security Management (using the ISO 17799 standard) and security engineering (using the Systems Security Engineering Capability Maturity Model – SSE-CMM). The aim of the Business Process Security Maturity model as the output of this research, is to link the SSE-CMM, as the security metric and appraisal method, to the ISO 17799 security standard, which provides the guidance for the information security management framework and security control selection, within the Business Process Management environment. The SSE-CMM, as the security version of the Capability Maturity Model, provides the necessary strategy to control the security engineering processes that support the information systems and it maintains that as processes mature they become more predictable, effective and manageable. The aim of the model is to provide an integrated, mature security strategy within the business process and monitor and correct the security posture of the implemented counter-measures.
- 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
Challenges and opportunities: an evaluation of the implementation of gender mainstreaming in South African government departments, with specific reference to the department of justice and constitutional development (DoJ&CD) and the department of foreign affairs (DFA)
- Authors: Sedibelwana, Maria Valerie
- Date: 2008
- Subjects: Women government executives , Sex discrimination , Women in the civil service -- South Africa , Gender mainstreaming -- South Africa
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: vital:8243 , http://hdl.handle.net/10948/757 , Women government executives , Sex discrimination , Women in the civil service -- South Africa , Gender mainstreaming -- South Africa
- Description: The aim of this research project is to conduct an evaluation on the implementation of gender mainstreaming in South African government departments, with specific reference to the Department of Justice and Constitutional Development (DoJ&CD) and the Department of Foreign Affairs (DFA). The research project is based on the hypothesis that despite the existence of a National Gender Machinery, Gender Focal Points (GFPs) face numerous challenges in implementing gender mainstreaming, due to various internal and external factors. Based on the two case studies, the research project concludes that despite a strong commitment from government, GFPs still face challenges in effectively implementing gender mainstreaming. This is due to a lack of accountability, an understanding of the concept of gender mainstreaming, as well as a lack of resources. Furthermore, systemic weaknesses within the National Gender Machinery are exacerbating the challenges faced GFP
- Full Text:
- Date Issued: 2008
- Authors: Sedibelwana, Maria Valerie
- Date: 2008
- Subjects: Women government executives , Sex discrimination , Women in the civil service -- South Africa , Gender mainstreaming -- South Africa
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: vital:8243 , http://hdl.handle.net/10948/757 , Women government executives , Sex discrimination , Women in the civil service -- South Africa , Gender mainstreaming -- South Africa
- Description: The aim of this research project is to conduct an evaluation on the implementation of gender mainstreaming in South African government departments, with specific reference to the Department of Justice and Constitutional Development (DoJ&CD) and the Department of Foreign Affairs (DFA). The research project is based on the hypothesis that despite the existence of a National Gender Machinery, Gender Focal Points (GFPs) face numerous challenges in implementing gender mainstreaming, due to various internal and external factors. Based on the two case studies, the research project concludes that despite a strong commitment from government, GFPs still face challenges in effectively implementing gender mainstreaming. This is due to a lack of accountability, an understanding of the concept of gender mainstreaming, as well as a lack of resources. Furthermore, systemic weaknesses within the National Gender Machinery are exacerbating the challenges faced GFP
- Full Text:
- Date Issued: 2008
Challenges faced by secondary school teachers in integrating ICT into the curriculum: a multiple case study in the Grahamstown Circuit
- Maholwana-Sotashe, Nikiwe Laura
- Authors: Maholwana-Sotashe, Nikiwe Laura
- Date: 2008
- Subjects: Educational technology -- South Africa -- Grahamstown Education, Secondary -- South Africa -- Grahamstown -- Data processing Information technology -- Study and teaching (Secondary) -- South Africa -- Grahamstown Internet in education -- South Africa -- Grahamstown Information technology -- South Africa -- Grahamstown Computer-assisted instruction -- South Africa -- Grahamstown Education, Secondary -- Curricula -- South Africa -- Grahamstown Educational innovations
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1445 , http://hdl.handle.net/10962/d1003326
- Description: The integration of Information and Communication Technology (ICT) into the curriculum has become the major issue worldwide. The education system does not only pursue the integration of ICT into the curriculum because of its popularity in the market system, but because of the role it is perceived to play in the changing curriculum (encourages active construction of knowledge). According to White Paper 7 e-Education policy (2004:17) every South African learner should be able to use ICTs confidently and creatively to develop the skills and knowledge they need to achieve personal goals and to be full participants in the global community by 2013. The central role played by teachers in teaching and learning requires them to have a holistic understanding of ICT integration. Furthermore they should be able to analyse when ICT integration is appropriate according to what is expected from the learner in the teaching and learning process. Drawing on the evidence from a survey of nine secondary schools in the Grahamstown Circuit of the Eastern Cape, this study examines how teachers from three different types of secondary schools: Former Department of Education (FDET) schools, Former House of Representatives (FHOR) schools and Former Model C (FMC) schools perceive the integration of ICTs in the curriculum. The salient ideas of how teachers perceive the integration of ICTs into the curriculum emerge from what they view as benefits of using ICT and what they view as challenges of integrating ICT into the curriculum. Contrary to expectations, the degree of ICT integration within the curriculum did not correspond directly with the availability of sufficient hardware, software or Internet connectivity at the participating schools.
- Full Text:
- Date Issued: 2008
- Authors: Maholwana-Sotashe, Nikiwe Laura
- Date: 2008
- Subjects: Educational technology -- South Africa -- Grahamstown Education, Secondary -- South Africa -- Grahamstown -- Data processing Information technology -- Study and teaching (Secondary) -- South Africa -- Grahamstown Internet in education -- South Africa -- Grahamstown Information technology -- South Africa -- Grahamstown Computer-assisted instruction -- South Africa -- Grahamstown Education, Secondary -- Curricula -- South Africa -- Grahamstown Educational innovations
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1445 , http://hdl.handle.net/10962/d1003326
- Description: The integration of Information and Communication Technology (ICT) into the curriculum has become the major issue worldwide. The education system does not only pursue the integration of ICT into the curriculum because of its popularity in the market system, but because of the role it is perceived to play in the changing curriculum (encourages active construction of knowledge). According to White Paper 7 e-Education policy (2004:17) every South African learner should be able to use ICTs confidently and creatively to develop the skills and knowledge they need to achieve personal goals and to be full participants in the global community by 2013. The central role played by teachers in teaching and learning requires them to have a holistic understanding of ICT integration. Furthermore they should be able to analyse when ICT integration is appropriate according to what is expected from the learner in the teaching and learning process. Drawing on the evidence from a survey of nine secondary schools in the Grahamstown Circuit of the Eastern Cape, this study examines how teachers from three different types of secondary schools: Former Department of Education (FDET) schools, Former House of Representatives (FHOR) schools and Former Model C (FMC) schools perceive the integration of ICTs in the curriculum. The salient ideas of how teachers perceive the integration of ICTs into the curriculum emerge from what they view as benefits of using ICT and what they view as challenges of integrating ICT into the curriculum. Contrary to expectations, the degree of ICT integration within the curriculum did not correspond directly with the availability of sufficient hardware, software or Internet connectivity at the participating schools.
- Full Text:
- Date Issued: 2008
Changing words and worlds?: a phenomenological study of the acquisition of an academic literacy
- Authors: Thomson, Carol Irene
- Date: 2008
- Subjects: Education -- Study and teaching (Higher) -- South Africa Universities and colleges -- South Africa College student development programs -- South Africa Literacy -- South Africa Education, Higher -- Philosophy Educational change -- South Africa Phenomenology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1446 , http://hdl.handle.net/10962/d1003327
- Description: This study is contextualised within the field of post-graduate, continuing teacher education, and the vibrant and demanding policy context that has characterised higher education in post-apartheid South Africa. Situated within a module specifically designed to address what is commonly understood to be the academic literacy development needs of students in the Bachelor of Education Honours programme at the former University of Natal, it aims to unveil the lived experiences of students taking this module. The module, Reading and Writing Academic Texts (RWAT), was developed in direct response to academics’ call that something be done about the ‘problem’ of students’ reading and writing proficiency. As a core, compulsory module, RWAT was informed by Systemic Functional Linguistics and drew on Genre Theory for its conceptual and theoretical framework. It foregrounded the genre of the academic argument as the key academic literacy that was taught. The motivation for this study came from my own increasing concern that the theoretical and conceptual framework we had adopted for the module was emerging as an inherently limiting and formulaic model of literacy, and was resulting in students exiting the module with little or no ‘critical’ perspective on any aspect of literacy as social practice. I was also keen, in a climate of increasing de-personalisation and the massification of education, to reinstate the personal. Thus, I chose to focus on individual lives, and through an exploration of a small group of participants’ ‘lived’ experiences of the RWAT module, ascertain what it is like to acquire an academic literacy. The key research question is, therefore: What is it like to acquire an academic literacy? The secondary research question is: How is this experience influenced by the mode of delivery in which it occurs? For its conceptual and theoretical framing, this study draws on social literacy theory and phenomenology, the latter as both a philosophy and a methodology. However, although the study has drawn significantly on the phenomenological tradition for inspiration and direction, it has not done so uncritically. Thus, the study engages with phenomenology-as-philosophy in great depth before turning to phenomenology-as-methodology, in order to arrive at a point where the methods and procedures applied in it, are justified. The main findings of the study suggest that, despite the RWAT module espousing an ideological model (Street, 1984) of literacy in its learning materials and readings, participants came very much closer to experiencing an autonomous model of literacy (Street, 1984). The data shows that the RWAT module was largely inadequate to the task of inducting participants into the ‘situated practices’ and ‘situated meanings’ of the Discourse of Genre Theory and/or the academy, hence the many ‘lived’ difficulties participants experienced. The data also highlights the ease with which an autonomous model of literacy can come to govern practice and student experience even when curriculum intention is underpinned by an ideological position on literacy as social practice. Finally, the study suggests that the research community in South Africa, characterised as it is by such diversity, would be enriched by more studies derived from phenomenology, and a continuing engagement with phenomenology-as-a-movement in order to both challenge and expand its existing framework.
- Full Text:
- Date Issued: 2008
- Authors: Thomson, Carol Irene
- Date: 2008
- Subjects: Education -- Study and teaching (Higher) -- South Africa Universities and colleges -- South Africa College student development programs -- South Africa Literacy -- South Africa Education, Higher -- Philosophy Educational change -- South Africa Phenomenology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1446 , http://hdl.handle.net/10962/d1003327
- Description: This study is contextualised within the field of post-graduate, continuing teacher education, and the vibrant and demanding policy context that has characterised higher education in post-apartheid South Africa. Situated within a module specifically designed to address what is commonly understood to be the academic literacy development needs of students in the Bachelor of Education Honours programme at the former University of Natal, it aims to unveil the lived experiences of students taking this module. The module, Reading and Writing Academic Texts (RWAT), was developed in direct response to academics’ call that something be done about the ‘problem’ of students’ reading and writing proficiency. As a core, compulsory module, RWAT was informed by Systemic Functional Linguistics and drew on Genre Theory for its conceptual and theoretical framework. It foregrounded the genre of the academic argument as the key academic literacy that was taught. The motivation for this study came from my own increasing concern that the theoretical and conceptual framework we had adopted for the module was emerging as an inherently limiting and formulaic model of literacy, and was resulting in students exiting the module with little or no ‘critical’ perspective on any aspect of literacy as social practice. I was also keen, in a climate of increasing de-personalisation and the massification of education, to reinstate the personal. Thus, I chose to focus on individual lives, and through an exploration of a small group of participants’ ‘lived’ experiences of the RWAT module, ascertain what it is like to acquire an academic literacy. The key research question is, therefore: What is it like to acquire an academic literacy? The secondary research question is: How is this experience influenced by the mode of delivery in which it occurs? For its conceptual and theoretical framing, this study draws on social literacy theory and phenomenology, the latter as both a philosophy and a methodology. However, although the study has drawn significantly on the phenomenological tradition for inspiration and direction, it has not done so uncritically. Thus, the study engages with phenomenology-as-philosophy in great depth before turning to phenomenology-as-methodology, in order to arrive at a point where the methods and procedures applied in it, are justified. The main findings of the study suggest that, despite the RWAT module espousing an ideological model (Street, 1984) of literacy in its learning materials and readings, participants came very much closer to experiencing an autonomous model of literacy (Street, 1984). The data shows that the RWAT module was largely inadequate to the task of inducting participants into the ‘situated practices’ and ‘situated meanings’ of the Discourse of Genre Theory and/or the academy, hence the many ‘lived’ difficulties participants experienced. The data also highlights the ease with which an autonomous model of literacy can come to govern practice and student experience even when curriculum intention is underpinned by an ideological position on literacy as social practice. Finally, the study suggests that the research community in South Africa, characterised as it is by such diversity, would be enriched by more studies derived from phenomenology, and a continuing engagement with phenomenology-as-a-movement in order to both challenge and expand its existing framework.
- Full Text:
- Date Issued: 2008
Characterization of a succession of small insect viruses in a wild South African population of Nudaurelia cytherea capensis (Lepidoptera: Saturniidae)
- Walter, Cheryl T, Tomasicchio, Michelle, Hodgson, V, Hendry, Donald A, Hill, Martin P, Dorrington, Rosemary A
- Authors: Walter, Cheryl T , Tomasicchio, Michelle , Hodgson, V , Hendry, Donald A , Hill, Martin P , Dorrington, Rosemary A
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6474 , http://hdl.handle.net/10962/d1006161 , http://www.scielo.org.za/scielo.php?pid=S0038-23532008000200015&script=sci_arttext
- Description: The Tetraviridae are a family of small insect RNA viruses first discovered in South Africa some 40 years ago. They consist of one or two single-stranded (+) RNAs encapsidated in an icosahedral capsid of approximately 40 nm in diameter, with T = 4 symmetry. The type members of the two genera within this family, Nudaurelia β virus (NβV) and Nudaurelia ω virus (NωV), infect Nudaurelia cytherea capensis (pine emperor moth) larvae. The absence of N. capensis laboratory colonies and tissue culture cell lines susceptible to virus infection have limited research on the biology of NβV and NωV because the availability of infectious virus is dependent upon sporadic outbreaks in the wild N. capensis populations. In September 2002, dead and dying N. capensis larvae exhibiting symptoms similar to those reported previously in other tetravirus infections were observed in a wild population in a pine forest in the Western Cape province of South Africa. We report here the isolation of three small insect viruses from this population over a period of three years. Transmission electron microscopy and serological characterization indicate that all three are tetra-like virus isolates. One isolate was shown by cDNA sequence analysis to be NβV, which was thought to have been extinct since 1985. The two other isolates are likely new tetraviruses, designated Nudaurelia ψ virus (NψV) and Nudaurelia ζ virus (NζV), which are morphologically and serologically related to NωV and NβV, respectively.
- Full Text:
- Date Issued: 2008
- Authors: Walter, Cheryl T , Tomasicchio, Michelle , Hodgson, V , Hendry, Donald A , Hill, Martin P , Dorrington, Rosemary A
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6474 , http://hdl.handle.net/10962/d1006161 , http://www.scielo.org.za/scielo.php?pid=S0038-23532008000200015&script=sci_arttext
- Description: The Tetraviridae are a family of small insect RNA viruses first discovered in South Africa some 40 years ago. They consist of one or two single-stranded (+) RNAs encapsidated in an icosahedral capsid of approximately 40 nm in diameter, with T = 4 symmetry. The type members of the two genera within this family, Nudaurelia β virus (NβV) and Nudaurelia ω virus (NωV), infect Nudaurelia cytherea capensis (pine emperor moth) larvae. The absence of N. capensis laboratory colonies and tissue culture cell lines susceptible to virus infection have limited research on the biology of NβV and NωV because the availability of infectious virus is dependent upon sporadic outbreaks in the wild N. capensis populations. In September 2002, dead and dying N. capensis larvae exhibiting symptoms similar to those reported previously in other tetravirus infections were observed in a wild population in a pine forest in the Western Cape province of South Africa. We report here the isolation of three small insect viruses from this population over a period of three years. Transmission electron microscopy and serological characterization indicate that all three are tetra-like virus isolates. One isolate was shown by cDNA sequence analysis to be NβV, which was thought to have been extinct since 1985. The two other isolates are likely new tetraviruses, designated Nudaurelia ψ virus (NψV) and Nudaurelia ζ virus (NζV), which are morphologically and serologically related to NωV and NβV, respectively.
- Full Text:
- Date Issued: 2008
Characterization of polarization dependent loss in optical fibres and optical components in the presence of polarization mode dispersion
- Authors: Pelaelo, Gaoboelwe
- Date: 2008
- Subjects: Fiber optics , Polarization (Light)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10528 , http://hdl.handle.net/10948/695 , Fiber optics , Polarization (Light)
- Description: In this study, the Jones matrix eigenanalysis (JME), optical spectrum analyzer (OSA) and polarization scrambling methods were used to investigate polarization dependent loss (PDL) in the presence of polarization mode dispersion (PMD) in optical components and fibres. The PDL measurements were conducted both in the laboratory and in the field. For field measurements, a buried link (28.8 km) and an aerial fibre (7.1 km) were extensively studied. The findings obtained from these studies are very important for network operators who must assess the impact of PDL on the network reliability. The three different PDL measurement methods (JME, OSA and polarization scrambling) were compared and their PDL values were found to agree very well at the selected wavelength of 1550 nm. Concatenation of PDL components showed that as expected, PDL increase as the number of PDL components were added. The interactions between PMD and PDL measurements were analyzed. A PMD/PDL emulator was constructed. We observed that PMD decreased while PDL increased. The PMD decrease was a result of the PMD vector cancellation enhanced by the randomly distributed mode coupling angles while PDL increase was a result of each PM fibre segments contributing to the overall global PDL. It was observed that the presence of PMD in a link containing PDL, results in PDL being wavelength dependent and this resulted in the extraction of the PMD information from the PDL data. PDL was found to be Maxwellian distributed when considering low values of PMD. High PMD values resulted in the PDL distribution deviating from Maxwellian. Long-term PDL and PMD (average DGD) measurements indicated that the PDL and PMD varied slowly with time and wavelength for both the laboratory and field measurements. It was observed that the BER increase as both PDL and PMD increased for simulated optical link.
- Full Text:
- Date Issued: 2008
- Authors: Pelaelo, Gaoboelwe
- Date: 2008
- Subjects: Fiber optics , Polarization (Light)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10528 , http://hdl.handle.net/10948/695 , Fiber optics , Polarization (Light)
- Description: In this study, the Jones matrix eigenanalysis (JME), optical spectrum analyzer (OSA) and polarization scrambling methods were used to investigate polarization dependent loss (PDL) in the presence of polarization mode dispersion (PMD) in optical components and fibres. The PDL measurements were conducted both in the laboratory and in the field. For field measurements, a buried link (28.8 km) and an aerial fibre (7.1 km) were extensively studied. The findings obtained from these studies are very important for network operators who must assess the impact of PDL on the network reliability. The three different PDL measurement methods (JME, OSA and polarization scrambling) were compared and their PDL values were found to agree very well at the selected wavelength of 1550 nm. Concatenation of PDL components showed that as expected, PDL increase as the number of PDL components were added. The interactions between PMD and PDL measurements were analyzed. A PMD/PDL emulator was constructed. We observed that PMD decreased while PDL increased. The PMD decrease was a result of the PMD vector cancellation enhanced by the randomly distributed mode coupling angles while PDL increase was a result of each PM fibre segments contributing to the overall global PDL. It was observed that the presence of PMD in a link containing PDL, results in PDL being wavelength dependent and this resulted in the extraction of the PMD information from the PDL data. PDL was found to be Maxwellian distributed when considering low values of PMD. High PMD values resulted in the PDL distribution deviating from Maxwellian. Long-term PDL and PMD (average DGD) measurements indicated that the PDL and PMD varied slowly with time and wavelength for both the laboratory and field measurements. It was observed that the BER increase as both PDL and PMD increased for simulated optical link.
- Full Text:
- Date Issued: 2008
Characterization of polarization effects on deployed aerial optical fibre in South Africa
- Authors: Mudau, Azwitamisi Eric
- Date: 2008
- Subjects: Polarization (Light) , Fiber optics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10521 , http://hdl.handle.net/10948/1060 , Polarization (Light) , Fiber optics
- Description: In this study, two polarization effects, namely the state of polarization (SOP) and polarization mode dispersion (PMD) in optical fibre cable are investigated. The change in polarization effects introduces errors in optical fibre communication system. We find that the SOP drifts slowly in buried cables, and rapidly in aerial cables. This is because buried cables are located in a static environment, whereas aerial cables are exposed directly to a dynamic environment. The SOP change in aerial cable shows significant correlation with its environment (the global radiation, temperature and wind). The autocorrelation function (ACF) was not performed in buried cable, since they do not satisfy the ACF assumption, whereas in aerial cable it is found that the ACF of the SOP decorrelates quite quickly during the day. The 50 percent decorrelation time during the day and night are 9.6 and 30.4 minutes, respectively. During the day the properties of the optical fibre change rapidly as a result of the rapidly changing environmental conditions, whereas at night the environmental conditions change relatively slowly. Fast Fourier Transform (FFT) of the SOP fluctuations show discrete peaks, which corresponds to the wind induced vibrational frequency of the cable. The PMD fluctuations for undeployed and deployed aerial optical fibre cable are monitored using the generalized interferometric technique (GINTY). It is found that the PMD measured with polarization scrambling is more scattered but more reliable than the PMD measured without polarization scrambling. This is because the PMD obtained with polarization scrambling is averaged over different input and output (I/O) SOP pairs. For deployed aerial cable, it is found that the PMD measured without polarization scrambling fluctuates rapidly during high wind speed conditions. Furthermore, there is a correlation between the measured PMD and the change in temperature. It is found that the change in temperature has a stronger influence than the wind on the PMD of the optical fibre link.
- Full Text:
- Date Issued: 2008
- Authors: Mudau, Azwitamisi Eric
- Date: 2008
- Subjects: Polarization (Light) , Fiber optics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10521 , http://hdl.handle.net/10948/1060 , Polarization (Light) , Fiber optics
- Description: In this study, two polarization effects, namely the state of polarization (SOP) and polarization mode dispersion (PMD) in optical fibre cable are investigated. The change in polarization effects introduces errors in optical fibre communication system. We find that the SOP drifts slowly in buried cables, and rapidly in aerial cables. This is because buried cables are located in a static environment, whereas aerial cables are exposed directly to a dynamic environment. The SOP change in aerial cable shows significant correlation with its environment (the global radiation, temperature and wind). The autocorrelation function (ACF) was not performed in buried cable, since they do not satisfy the ACF assumption, whereas in aerial cable it is found that the ACF of the SOP decorrelates quite quickly during the day. The 50 percent decorrelation time during the day and night are 9.6 and 30.4 minutes, respectively. During the day the properties of the optical fibre change rapidly as a result of the rapidly changing environmental conditions, whereas at night the environmental conditions change relatively slowly. Fast Fourier Transform (FFT) of the SOP fluctuations show discrete peaks, which corresponds to the wind induced vibrational frequency of the cable. The PMD fluctuations for undeployed and deployed aerial optical fibre cable are monitored using the generalized interferometric technique (GINTY). It is found that the PMD measured with polarization scrambling is more scattered but more reliable than the PMD measured without polarization scrambling. This is because the PMD obtained with polarization scrambling is averaged over different input and output (I/O) SOP pairs. For deployed aerial cable, it is found that the PMD measured without polarization scrambling fluctuates rapidly during high wind speed conditions. Furthermore, there is a correlation between the measured PMD and the change in temperature. It is found that the change in temperature has a stronger influence than the wind on the PMD of the optical fibre link.
- Full Text:
- Date Issued: 2008
Cluster centre principals' perceptions of the implementation of the school cluster system in Namibia
- Authors: Aipinge, Lydia P
- Date: 2008
- Subjects: School management and organization -- Namibia Education -- Namibia School principals -- Namibia Educational leadership -- Namibia Educational change -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1449 , http://hdl.handle.net/10962/d1003330
- Description: The School Clustering System (SCS) was introduced five years after Namibia’s independence in 1990. The rationale for its implementation was to improve the quality of education in Namibian schools by enabling the sharing of resources, experience and expertise among clusters and facilitating school administration by pooling resources from several schools to be shared equally. It was piloted in Rundu and then gradually expanded to the whole country. The cluster system groups 5-7 schools that are eographically close and accessible to each other in one cluster under the leadership of one of the principals known as a Cluster Centre Principal (CCP). The purpose of this study was to investigate the perceptions of CCPs of the implementation of the SCS in two clusters of a particular circuit in the Omusati region. It is a case study involving two CCPs, one serving Inspector of Education (IE), a former Inspector of Education, several teachers, principals and parents. Data were collected through interviews, document analysis, and focus group discussions. The study found that the practice of cluster leaders is informed by contemporary leadership and management thinking. The participatory approach employed in clusterbased committees enables site-based management and collaboration. This has led to organisational learning. It was also found that a number of challenges are hampering the implementation of the SCS. These include lack of system support and inadequate resources. However, the human potential coupled with a high degree of readiness exhibited by cluster members are seen as potential drivers of further development of the system. The study recommends the adoption of a national policy that formalises the SCS as well as the strengthening of system support to build cluster capacity. It also makes suggestions for further research in organisational culture and behaviour with the aim of developing leadership and management practices in the SCS.
- Full Text:
- Date Issued: 2008
Cluster centre principals' perceptions of the implementation of the school cluster system in Namibia
- Authors: Aipinge, Lydia P
- Date: 2008
- Subjects: School management and organization -- Namibia Education -- Namibia School principals -- Namibia Educational leadership -- Namibia Educational change -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1449 , http://hdl.handle.net/10962/d1003330
- Description: The School Clustering System (SCS) was introduced five years after Namibia’s independence in 1990. The rationale for its implementation was to improve the quality of education in Namibian schools by enabling the sharing of resources, experience and expertise among clusters and facilitating school administration by pooling resources from several schools to be shared equally. It was piloted in Rundu and then gradually expanded to the whole country. The cluster system groups 5-7 schools that are eographically close and accessible to each other in one cluster under the leadership of one of the principals known as a Cluster Centre Principal (CCP). The purpose of this study was to investigate the perceptions of CCPs of the implementation of the SCS in two clusters of a particular circuit in the Omusati region. It is a case study involving two CCPs, one serving Inspector of Education (IE), a former Inspector of Education, several teachers, principals and parents. Data were collected through interviews, document analysis, and focus group discussions. The study found that the practice of cluster leaders is informed by contemporary leadership and management thinking. The participatory approach employed in clusterbased committees enables site-based management and collaboration. This has led to organisational learning. It was also found that a number of challenges are hampering the implementation of the SCS. These include lack of system support and inadequate resources. However, the human potential coupled with a high degree of readiness exhibited by cluster members are seen as potential drivers of further development of the system. The study recommends the adoption of a national policy that formalises the SCS as well as the strengthening of system support to build cluster capacity. It also makes suggestions for further research in organisational culture and behaviour with the aim of developing leadership and management practices in the SCS.
- Full Text:
- Date Issued: 2008
Coastal topography drives genetic structure in marine mussels
- Nicastro, Katy R, Zardi, Gerardo I, McQuaid, Christopher D, Teske, Peter R, Barker, Nigel P
- Authors: Nicastro, Katy R , Zardi, Gerardo I , McQuaid, Christopher D , Teske, Peter R , Barker, Nigel P
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445634 , vital:74409 , https://doi.org/10.3354/meps07607
- Description: Understanding population connectivity is fundamental to ecology, and, for sedentary organisms, connectivity is achieved through larval dispersal. We tested whether coastal topography influences genetic structure in Perna perna mussels by comparing populations inside bays and on the open coast. Higher hydrodynamic stress on the open coast produces higher mortality and thus genetic turnover. Populations on the open coast had fewer private haplotypes and less genetic endemism than those inside bays. Gene flow analysis showed that bays act as source populations, with greater migration rates out of bays than into them. Differences in genetic structure on scales of 10s of kilometres show that coastal configuration strongly affects selection, larval dispersal and haplotype diversity.
- Full Text: false
- Date Issued: 2008
- Authors: Nicastro, Katy R , Zardi, Gerardo I , McQuaid, Christopher D , Teske, Peter R , Barker, Nigel P
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445634 , vital:74409 , https://doi.org/10.3354/meps07607
- Description: Understanding population connectivity is fundamental to ecology, and, for sedentary organisms, connectivity is achieved through larval dispersal. We tested whether coastal topography influences genetic structure in Perna perna mussels by comparing populations inside bays and on the open coast. Higher hydrodynamic stress on the open coast produces higher mortality and thus genetic turnover. Populations on the open coast had fewer private haplotypes and less genetic endemism than those inside bays. Gene flow analysis showed that bays act as source populations, with greater migration rates out of bays than into them. Differences in genetic structure on scales of 10s of kilometres show that coastal configuration strongly affects selection, larval dispersal and haplotype diversity.
- Full Text: false
- Date Issued: 2008
Coming to terms with the "Border War" in post-apartheid South Africa
- Authors: Baines, Gary F
- Date: 2008
- Language: English
- Type: Conference paper
- Identifier: vital:6157 , http://hdl.handle.net/10962/d1007077
- Description: If you are a white, male South African between the ages of about 35 and 60 it is very likely that you donned the nutria brown uniform of the South African Defence Force (SADF). Between 1967 and 1994 approximately 300 000 young white males were conscripted by the SADF. As far as most of these conscripts were concerned, there was no option other than heeding the call-up and performing national service or diensplig. Failure to do so meant harsh penalties. The alternatives were to object on conscientious (actually religious) grounds and face a six year jail sentence, or flee the country. And the obligation did not end with national service as conscripts were assigned to citizen force or commando units that were liable for periodical call-ups for camps that might have included deployment in the “operational areas” from 1974 or tours of duty in the black townships from 1984. Those - like myself - belonging to this national service generation were part-time soldiers for much of their adult lives. Most served willingly, some with patriotic fervour. Others did so reluctantly and with little enthusiasm.
- Full Text:
- Date Issued: 2008
- Authors: Baines, Gary F
- Date: 2008
- Language: English
- Type: Conference paper
- Identifier: vital:6157 , http://hdl.handle.net/10962/d1007077
- Description: If you are a white, male South African between the ages of about 35 and 60 it is very likely that you donned the nutria brown uniform of the South African Defence Force (SADF). Between 1967 and 1994 approximately 300 000 young white males were conscripted by the SADF. As far as most of these conscripts were concerned, there was no option other than heeding the call-up and performing national service or diensplig. Failure to do so meant harsh penalties. The alternatives were to object on conscientious (actually religious) grounds and face a six year jail sentence, or flee the country. And the obligation did not end with national service as conscripts were assigned to citizen force or commando units that were liable for periodical call-ups for camps that might have included deployment in the “operational areas” from 1974 or tours of duty in the black townships from 1984. Those - like myself - belonging to this national service generation were part-time soldiers for much of their adult lives. Most served willingly, some with patriotic fervour. Others did so reluctantly and with little enthusiasm.
- Full Text:
- Date Issued: 2008
Commodity fetishism and domination: the contributions of Marx, Lukács, Horkheimer, Adorno and Bourdieu
- Authors: Lloyd, Gareth
- Date: 2008
- Subjects: Marx, Karl, 1818-1883 Lukács, György, 1885-1971 Horkheimer, Max, 1895-1973 Adorno, Theodor W., 1903-1969 Bourdieu, Pierre, 1930-2002 Commodity fetishism Capitalism Consumption (Economics) Marxian economics
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2795 , http://hdl.handle.net/10962/d1003005
- Description: This thesis seeks to trace domination theory back to the influential work done by Marx on commodity fetishism. Marx's work proves to be an original account of domination that explains how the dominated many accept the rule of the privileged few. The theory of commodity fetishism develops the idea that individuals come to adopt beliefs that bolster and reproduce the status quo of capitalism. For Marx, the way that individuals experience capitalism is different from the way that it actually works because, in fact, lived experience is actually false. Oppression, inequality and exploitation are thus hidden and the main source of conflict between the oppressed many and the privileged few is obscured. I seek to develop this insight of Marx's into a more comprehensive account of how dominating capitalism self maintains. Lukács' theory of reification explains how capitalism has become all-embracing because capitalism has developed its own type of rationality. This specific rationality shapes thought, which in turn, generates false beliefs that favour the continuation of the status quo. Horkheimer and Adorno argue that capitalism extends its influence by means of its deep involvement in modern culture. Today, culture has become an massive industry which inculcates the logic and principles of capitalism into individuals. For these theorists, capitalism has penetrated all areas of life; experience, knowledge and thought have become extensions of capitalism itself. Marx, Lukács, Horkheimer and Adorno give accounts of how false beliefs are put into practice. Hence the importance of the work of Bourdieu. Bourdieu's theory of distinction describes how the status quo in capitalism is maintained by the behaviour of individuals through their daily acts of consumption. I argue that the consumption of commodities reproduces the status quo in two ways: firstly, establishing an upper-class which takes the lead in patterns of consumption, and, secondly, by creating a middle class that follows its example. Finally, I relate Bourdieu's insights to the theories of Marx, Lukács, Horkheimer and Adorno and Bourdieu in order to arrive at a more inclusive account of how.
- Full Text:
- Date Issued: 2008
- Authors: Lloyd, Gareth
- Date: 2008
- Subjects: Marx, Karl, 1818-1883 Lukács, György, 1885-1971 Horkheimer, Max, 1895-1973 Adorno, Theodor W., 1903-1969 Bourdieu, Pierre, 1930-2002 Commodity fetishism Capitalism Consumption (Economics) Marxian economics
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2795 , http://hdl.handle.net/10962/d1003005
- Description: This thesis seeks to trace domination theory back to the influential work done by Marx on commodity fetishism. Marx's work proves to be an original account of domination that explains how the dominated many accept the rule of the privileged few. The theory of commodity fetishism develops the idea that individuals come to adopt beliefs that bolster and reproduce the status quo of capitalism. For Marx, the way that individuals experience capitalism is different from the way that it actually works because, in fact, lived experience is actually false. Oppression, inequality and exploitation are thus hidden and the main source of conflict between the oppressed many and the privileged few is obscured. I seek to develop this insight of Marx's into a more comprehensive account of how dominating capitalism self maintains. Lukács' theory of reification explains how capitalism has become all-embracing because capitalism has developed its own type of rationality. This specific rationality shapes thought, which in turn, generates false beliefs that favour the continuation of the status quo. Horkheimer and Adorno argue that capitalism extends its influence by means of its deep involvement in modern culture. Today, culture has become an massive industry which inculcates the logic and principles of capitalism into individuals. For these theorists, capitalism has penetrated all areas of life; experience, knowledge and thought have become extensions of capitalism itself. Marx, Lukács, Horkheimer and Adorno give accounts of how false beliefs are put into practice. Hence the importance of the work of Bourdieu. Bourdieu's theory of distinction describes how the status quo in capitalism is maintained by the behaviour of individuals through their daily acts of consumption. I argue that the consumption of commodities reproduces the status quo in two ways: firstly, establishing an upper-class which takes the lead in patterns of consumption, and, secondly, by creating a middle class that follows its example. Finally, I relate Bourdieu's insights to the theories of Marx, Lukács, Horkheimer and Adorno and Bourdieu in order to arrive at a more inclusive account of how.
- 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