Thermal degradation of diamond compacts: a TEM investigation
- Authors: Westraadt, Johan Ewald
- Date: 2011
- Subjects: Materials -- Thermal properties Chemical weathering
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/10829 , vital:26827
- Description: Diamond compacts consist of fine diamond grains bonded together by using high pressure and high temperature. In this study transmission electron microscopy (TEM)was used to study thermal degradation of diamond compacts. Three different types of diamond compacts – namely cobalt polycrystalline diamond (PCD), calcium carbonate PCD, and diamond-SiC composites – were investigated with TEM to understand the processes that occur during synthesis. These compacts were then heated in inert atmospheres and the chemical changes studied with TEM. It was found that PCD, using cobalt as a bonding agent, will degrade after exposure to temperatures above 750ºC. The cobalt pools contain tungsten in solid solution. During heat treatment above 700ºC the solid solution tungsten combines with cobalt and dissolved carbon to form η-phase particles at the cobalt/diamond interface. At higher temperatures or insufficient tungsten levels the rate of dissolved carbon, into the cobalt pool, is too high and the excess carbon will form as graphite in the cobalt pool. Increased levels of solid solution tungsten, in the cobalt, is expected to delay the onset of graphitization in the diamond compact, thereby increasing the thermal stability of the diamond compact. Non-metallic PCD using calcium carbonate as a bonding agent was successfully sintered in this study. TEM revealed similar micro-structural features as in cobalt based PCD. No signs of thermal degradation were found after exposure to 1200ºC in vacuum for this PCD. Contaminants introduced during processing prevented a detailed study of the binder in this system. The effect of substitutional metal atoms and plastic deformation of diamond on the thermal stability of diamond-SiC composites were investigated. A piston cylinder press was developed and used to synthesize diamond-SiC composites with different levels of plastically deformed diamond. It was concluded that substitutional metal atoms and plastic deformation of diamond grains play no role in the thermal degradation of diamond compacts at 750ºC. The thermal degradation of cobalt PCD is therefore completely determined by the cobalt/diamond interaction at 750ºC.
- Full Text:
- Date Issued: 2011
- Authors: Westraadt, Johan Ewald
- Date: 2011
- Subjects: Materials -- Thermal properties Chemical weathering
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/10829 , vital:26827
- Description: Diamond compacts consist of fine diamond grains bonded together by using high pressure and high temperature. In this study transmission electron microscopy (TEM)was used to study thermal degradation of diamond compacts. Three different types of diamond compacts – namely cobalt polycrystalline diamond (PCD), calcium carbonate PCD, and diamond-SiC composites – were investigated with TEM to understand the processes that occur during synthesis. These compacts were then heated in inert atmospheres and the chemical changes studied with TEM. It was found that PCD, using cobalt as a bonding agent, will degrade after exposure to temperatures above 750ºC. The cobalt pools contain tungsten in solid solution. During heat treatment above 700ºC the solid solution tungsten combines with cobalt and dissolved carbon to form η-phase particles at the cobalt/diamond interface. At higher temperatures or insufficient tungsten levels the rate of dissolved carbon, into the cobalt pool, is too high and the excess carbon will form as graphite in the cobalt pool. Increased levels of solid solution tungsten, in the cobalt, is expected to delay the onset of graphitization in the diamond compact, thereby increasing the thermal stability of the diamond compact. Non-metallic PCD using calcium carbonate as a bonding agent was successfully sintered in this study. TEM revealed similar micro-structural features as in cobalt based PCD. No signs of thermal degradation were found after exposure to 1200ºC in vacuum for this PCD. Contaminants introduced during processing prevented a detailed study of the binder in this system. The effect of substitutional metal atoms and plastic deformation of diamond on the thermal stability of diamond-SiC composites were investigated. A piston cylinder press was developed and used to synthesize diamond-SiC composites with different levels of plastically deformed diamond. It was concluded that substitutional metal atoms and plastic deformation of diamond grains play no role in the thermal degradation of diamond compacts at 750ºC. The thermal degradation of cobalt PCD is therefore completely determined by the cobalt/diamond interaction at 750ºC.
- Full Text:
- Date Issued: 2011
The entrepreneurial orientation of selected ICT SMME's
- Authors: Whittaker, Donna
- Date: 2011
- Subjects: Business enterprises , Information technology
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8754 , http://hdl.handle.net/10948/d1011417 , Business enterprises , Information technology
- Description: Despite the demand for ICT skills, businesses are experiencing an ICT skills shortage. Constantly changing ICT technologies require business leaders to find qualified ICT professionals to implement new business strategies and business processes. The Information and Communications Technology (ICT) sector is experiencing a continued skills shortage and various initiatives have been launched to address the problem. Businesses continually struggle to find qualified and suitably skilled ICT personnel. As a result businesses have had to outsource their ICT requirements off-shore to obtain the required ICT skills and maintain their competitive advantage. In a country desperate for job creation, entrepreneurial inclination and start up of new businesses may play a pivotal role in the economic development and well being of individuals able to capitalise on the availability of ICT opportunities. Entrepreneurship is a critical factor in promoting innovation, creating employment opportunities and generating social and economic wealth in a country's economy. Sectors such as Information and Communication Technologies can be seen as archetypal entrepreneurial industries and can consequently play a key role in economic development. In the research that follows the author identifies an ICT skills shortage in South Africa. This is followed by an exploratory study that investigates the influence of psychological traits and socio-cultural variables on the entrepreneurial intent of selected ICT SMME’s in the Nelson Mandela Metropolitan Area. The findings revealed that both psychological traits together with socio-cultural variables influence an individual’s intention to start up a business. The predominant psychological trait discovered during the research was perseverance. Family environmental issues were the dominant socio-cultural variable influencing entrepreneurial intention amongst the case study subjects.
- Full Text:
- Date Issued: 2011
- Authors: Whittaker, Donna
- Date: 2011
- Subjects: Business enterprises , Information technology
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8754 , http://hdl.handle.net/10948/d1011417 , Business enterprises , Information technology
- Description: Despite the demand for ICT skills, businesses are experiencing an ICT skills shortage. Constantly changing ICT technologies require business leaders to find qualified ICT professionals to implement new business strategies and business processes. The Information and Communications Technology (ICT) sector is experiencing a continued skills shortage and various initiatives have been launched to address the problem. Businesses continually struggle to find qualified and suitably skilled ICT personnel. As a result businesses have had to outsource their ICT requirements off-shore to obtain the required ICT skills and maintain their competitive advantage. In a country desperate for job creation, entrepreneurial inclination and start up of new businesses may play a pivotal role in the economic development and well being of individuals able to capitalise on the availability of ICT opportunities. Entrepreneurship is a critical factor in promoting innovation, creating employment opportunities and generating social and economic wealth in a country's economy. Sectors such as Information and Communication Technologies can be seen as archetypal entrepreneurial industries and can consequently play a key role in economic development. In the research that follows the author identifies an ICT skills shortage in South Africa. This is followed by an exploratory study that investigates the influence of psychological traits and socio-cultural variables on the entrepreneurial intent of selected ICT SMME’s in the Nelson Mandela Metropolitan Area. The findings revealed that both psychological traits together with socio-cultural variables influence an individual’s intention to start up a business. The predominant psychological trait discovered during the research was perseverance. Family environmental issues were the dominant socio-cultural variable influencing entrepreneurial intention amongst the case study subjects.
- Full Text:
- Date Issued: 2011
Empowering teachers to render learner support to learners who experience reading barriers
- Authors: Wienand, Merna Adeliade
- Date: 2011
- Subjects: Inclusive eduction
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:9497 , http://hdl.handle.net/10948/1353 , Inclusive eduction
- Description: In this qualitative study the researcher provided proposed guidelines to empower teachers to render learner support to learners who experience reading barriers. A literature study was undertaken to investigate the importance and consequences of inclusive education, the need for a systematic approach, reading problems and its causes and remediation thereof. The empirical study includes interviews with important stakeholders and observations. The results of the empirical study culminated into proposed guidelines to empower teachers to render learner support to these learners. Recommendations were made based on the literature study and the results of the empirical research
- Full Text:
- Date Issued: 2011
- Authors: Wienand, Merna Adeliade
- Date: 2011
- Subjects: Inclusive eduction
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:9497 , http://hdl.handle.net/10948/1353 , Inclusive eduction
- Description: In this qualitative study the researcher provided proposed guidelines to empower teachers to render learner support to learners who experience reading barriers. A literature study was undertaken to investigate the importance and consequences of inclusive education, the need for a systematic approach, reading problems and its causes and remediation thereof. The empirical study includes interviews with important stakeholders and observations. The results of the empirical study culminated into proposed guidelines to empower teachers to render learner support to these learners. Recommendations were made based on the literature study and the results of the empirical research
- Full Text:
- Date Issued: 2011
Nelson Mandela Metropolitan University students' perceptions of sexualised advertisements of three South African fast food brands
- Authors: Wignall, Andrea
- Date: 2011
- Subjects: Sex in advertising -- South Africa -- Childhood and youth , Food industry and trade -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8408 , http://hdl.handle.net/10948/d1011443 , Sex in advertising -- South Africa -- Childhood and youth , Food industry and trade -- South Africa
- Description: This research study aimed to provide the South African fast food industry and their advertising representatives with insights into 18-28-year-olds‟ perception of using sexual appeal to elicit their attention, and whether using this advertising technique is gaining positive brand recognition with this target market. This research study aimed to determine the selected sample‟s (NMMU students) perceptions of three South African fast food brands, namely KFC, Nando’s and Steers, in terms of their use of sexualised fast food advertisements. An electronic survey questionnaire was conducted with both closed and open-ended questions relating to the use of sexual appeal in advertising within the three South African fast food brands. The survey questionnaire helped determine what the selected sample‟s perceptions were of each advertisement, and whether the use of sexual appeal captured their attention. A semiotic analysis of each advertisement was conducted to determine if the advertisements do contain the use of sexual appeal, by examining the sign. This includes looking at the three aspects of a sign namely the signifier, the referent and the signified. In terms of this study, the signifier represents the T.V. advertisements; the signified represents the meaning of the advertisements and the referent represents to what the advertisements are initially referring. The results of the study indicated that each of the three fast food advertisements incorporated the use of sexual appeal in varying degrees. Respondents indicated that the sexual appeal in the advertisements was appropriate if they were directed at the right age group. The respondents indicated that these three advertisements were more likely to attract the males, in the target market and they felt that the advertisements leaned towards objectifying the women, which would be offensive to the females in the target market. It was determined that if the advertisements contained humour, they were more effective and memorable.
- Full Text:
- Date Issued: 2011
- Authors: Wignall, Andrea
- Date: 2011
- Subjects: Sex in advertising -- South Africa -- Childhood and youth , Food industry and trade -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8408 , http://hdl.handle.net/10948/d1011443 , Sex in advertising -- South Africa -- Childhood and youth , Food industry and trade -- South Africa
- Description: This research study aimed to provide the South African fast food industry and their advertising representatives with insights into 18-28-year-olds‟ perception of using sexual appeal to elicit their attention, and whether using this advertising technique is gaining positive brand recognition with this target market. This research study aimed to determine the selected sample‟s (NMMU students) perceptions of three South African fast food brands, namely KFC, Nando’s and Steers, in terms of their use of sexualised fast food advertisements. An electronic survey questionnaire was conducted with both closed and open-ended questions relating to the use of sexual appeal in advertising within the three South African fast food brands. The survey questionnaire helped determine what the selected sample‟s perceptions were of each advertisement, and whether the use of sexual appeal captured their attention. A semiotic analysis of each advertisement was conducted to determine if the advertisements do contain the use of sexual appeal, by examining the sign. This includes looking at the three aspects of a sign namely the signifier, the referent and the signified. In terms of this study, the signifier represents the T.V. advertisements; the signified represents the meaning of the advertisements and the referent represents to what the advertisements are initially referring. The results of the study indicated that each of the three fast food advertisements incorporated the use of sexual appeal in varying degrees. Respondents indicated that the sexual appeal in the advertisements was appropriate if they were directed at the right age group. The respondents indicated that these three advertisements were more likely to attract the males, in the target market and they felt that the advertisements leaned towards objectifying the women, which would be offensive to the females in the target market. It was determined that if the advertisements contained humour, they were more effective and memorable.
- Full Text:
- Date Issued: 2011
Using social marketing to bridge the gap between systematic conservation planning and implementation at the local government level
- Authors: Wilhelm-Rechmann, Angelika
- Date: 2011
- Subjects: Nature conservation -- South Africa -- Eastern Cape , Land use -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10603 , http://hdl.handle.net/10948/1550 , Nature conservation -- South Africa -- Eastern Cape , Land use -- South Africa -- Eastern Cape
- Description: The study presented here describes an attempt to bridge the gap between systematic conservation assessment and decision-making for land-use planning in the Eastern Cape province, South Africa. The aim was to investigate how to effectively convince officials concerned with land use planning processes in the local municipal sphere to include conservation priorities meaningfully in their processes. The approach used to reach this aim was social marketing, the use of marketing technologies and concepts to effect behavior changes to further societal good. So far social marketing is not commonly used in the conservation domain; I therefore aimed also at proving the usefulness of this approach for conservation. Following the introduction which provides background to the project and a more detailed summary, Chapter 2 provides a detailed and comprehensive review of the considerations and concepts regarding the use of social marketing in a context geared at protecting nature. The research on the primary target group for this study, officials concerned with land use planning processes in the local municipal sphere is described in Chapter 3. The main outcomes were that land use planners perceive few needs with regards to implementing the incorporation of biodiversity conservation issues in the land use planning process, and that the deficiencies in the land use planning process per se, as well as the lack of recognition in the political sphere (the domain of elected councilors), represent the core barriers to adopting the conservation priorities. I conclude that to effect behavior change towards adoption of conservation priorities the land use planning processes need to be supported and the political sphere need to be included in the behavior change process. 6 Chapter 4 therefore focuses on the new target group that emerged as essential in the previous chapter, locally elected councilors. I found that councilors do actually consider land use planning procedures as being important, but also as being dysfunctional. Councilors do value their natural environment for themselves as well as for its tourism value, but most councilors had little understanding of what the term “biodiversity” means and did not connect the term “sustainability” with the natural environment. It became also evident, that councilors do not see conservation in a predominantly positive manner. Chapter 5 therefore yields insight on councilor’s perception that environmental protection and development are mutually exclusive, and the negative frames attached to the conservation endeavor as being socially unjust, disrespectful and utopian. In Chapter 6 I investigated the usefulness of a tractable and well established measure of environmental attitudes or beliefs. I assessed my target audience’s responses to the New Ecological Paradigm scale and the Inclusion of Nature in Self scale. I conclude in Chapter 7 with an account of the difficulties I encountered during the project, an assessment of my project from a social marketing perspective, components of my project that did not yield the results expected, and a proposal for future research.
- Full Text:
- Date Issued: 2011
- Authors: Wilhelm-Rechmann, Angelika
- Date: 2011
- Subjects: Nature conservation -- South Africa -- Eastern Cape , Land use -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10603 , http://hdl.handle.net/10948/1550 , Nature conservation -- South Africa -- Eastern Cape , Land use -- South Africa -- Eastern Cape
- Description: The study presented here describes an attempt to bridge the gap between systematic conservation assessment and decision-making for land-use planning in the Eastern Cape province, South Africa. The aim was to investigate how to effectively convince officials concerned with land use planning processes in the local municipal sphere to include conservation priorities meaningfully in their processes. The approach used to reach this aim was social marketing, the use of marketing technologies and concepts to effect behavior changes to further societal good. So far social marketing is not commonly used in the conservation domain; I therefore aimed also at proving the usefulness of this approach for conservation. Following the introduction which provides background to the project and a more detailed summary, Chapter 2 provides a detailed and comprehensive review of the considerations and concepts regarding the use of social marketing in a context geared at protecting nature. The research on the primary target group for this study, officials concerned with land use planning processes in the local municipal sphere is described in Chapter 3. The main outcomes were that land use planners perceive few needs with regards to implementing the incorporation of biodiversity conservation issues in the land use planning process, and that the deficiencies in the land use planning process per se, as well as the lack of recognition in the political sphere (the domain of elected councilors), represent the core barriers to adopting the conservation priorities. I conclude that to effect behavior change towards adoption of conservation priorities the land use planning processes need to be supported and the political sphere need to be included in the behavior change process. 6 Chapter 4 therefore focuses on the new target group that emerged as essential in the previous chapter, locally elected councilors. I found that councilors do actually consider land use planning procedures as being important, but also as being dysfunctional. Councilors do value their natural environment for themselves as well as for its tourism value, but most councilors had little understanding of what the term “biodiversity” means and did not connect the term “sustainability” with the natural environment. It became also evident, that councilors do not see conservation in a predominantly positive manner. Chapter 5 therefore yields insight on councilor’s perception that environmental protection and development are mutually exclusive, and the negative frames attached to the conservation endeavor as being socially unjust, disrespectful and utopian. In Chapter 6 I investigated the usefulness of a tractable and well established measure of environmental attitudes or beliefs. I assessed my target audience’s responses to the New Ecological Paradigm scale and the Inclusion of Nature in Self scale. I conclude in Chapter 7 with an account of the difficulties I encountered during the project, an assessment of my project from a social marketing perspective, components of my project that did not yield the results expected, and a proposal for future research.
- Full Text:
- Date Issued: 2011
A comparative analysis of the intermediary systems in South Africa, Namibia, Zimbabwe and Ethiopia
- Authors: Wilkerson, Tendai Marowa
- Date: 2011
- Subjects: Juvenile courts -- South Africa , Juvenile courts -- Namibia , Juveline courts -- Zimbabwe , Juvenile courts -- Ethiopia , Children -- Legal status, laws, etc. -- South Africa , Children -- Legal status, laws, etc. -- Namibia , Children -- Legal status, laws, etc. -- Zimbabwe , Children -- Legal status, laws, etc. -- Ethiopia , Child witnesses -- South Africa , Child witnesses -- Namibia , Child witnesses -- Zimbabwe , Child witnesses -- Ethiopia , Mediation -- Law and legislation -- South Africa , Mediation -- Law and legislation -- Namibia , Mediation -- Law and legislation -- Zimbabwe , Mediation -- Law and legislation -- Ethiopia , Children's rights -- South Africa , Children's rights -- Namibia , Children's rights -- Zimbabwe , Children's rights -- Ethiopia
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3698 , http://hdl.handle.net/10962/d1003213 , Juvenile courts -- South Africa , Juvenile courts -- Namibia , Juveline courts -- Zimbabwe , Juvenile courts -- Ethiopia , Children -- Legal status, laws, etc. -- South Africa , Children -- Legal status, laws, etc. -- Namibia , Children -- Legal status, laws, etc. -- Zimbabwe , Children -- Legal status, laws, etc. -- Ethiopia , Child witnesses -- South Africa , Child witnesses -- Namibia , Child witnesses -- Zimbabwe , Child witnesses -- Ethiopia , Mediation -- Law and legislation -- South Africa , Mediation -- Law and legislation -- Namibia , Mediation -- Law and legislation -- Zimbabwe , Mediation -- Law and legislation -- Ethiopia , Children's rights -- South Africa , Children's rights -- Namibia , Children's rights -- Zimbabwe , Children's rights -- Ethiopia
- Description: Prior to 1990, very few countries in the world offered special protection to child witnesses interfacing with the justice system. There were no legal provisions permitting testimonial accommodations for children in court. The courtroom experience was significantly traumatic for the children. With the international focus shifting from protecting and upholding the rights of the accused in the courtroom towards a more victim-centred approach, various international and regional instruments have strongly dvocated that children deserve special protection because of their vulnerability. In order for the courts to be able to elicit accurate evidence from the child without further traumatizing the child, research has shown that the child needs assistance. An intermediary may be defined as a person who facilitates communication between the child and the courtroom in a manner that takes into account the child‟s cognitive and developmental limitations. The thesis was prompted by the need to make a contribution to the currently limited body of literature on the intermediary systems in South Africa, Namibia, Zimbabwe and Ethiopia by investigating how the systems can be improved and sustained in a way that helps to protect the child witness in court. Despite the problems the South African courts have had in identifying the appropriate interpretation of its intermediary legislation, the country emerges as a clear leader for the steps it took by creating a positive legal framework within which child protection issues are addressed and introducing the concept of the intermediary. This concept proved to be an inspiration to its neighbours, Namibia and Zimbabwe. The influence of the South African intermediary legislation is evident in the Namibian and Zimbabwean legislation. Although Namibian legislators have drafted laws that permit intermediary assistance in court, there are as yet no intermediaries appointed. In Ethiopia, although there is no discernible intermediary legislation, the country has managed to establish an intermediary system. As a result of the analysis conducted, it is evident that the efficacy of the intermediary system is dependent on the presence of an enabling legislation, its clarity and ease of interpretation, the sensitisation of court role players on child vulnerabilities, the significance of intermediary assistance, and finally a government's commitment towards the implementation process.
- Full Text:
- Date Issued: 2011
- Authors: Wilkerson, Tendai Marowa
- Date: 2011
- Subjects: Juvenile courts -- South Africa , Juvenile courts -- Namibia , Juveline courts -- Zimbabwe , Juvenile courts -- Ethiopia , Children -- Legal status, laws, etc. -- South Africa , Children -- Legal status, laws, etc. -- Namibia , Children -- Legal status, laws, etc. -- Zimbabwe , Children -- Legal status, laws, etc. -- Ethiopia , Child witnesses -- South Africa , Child witnesses -- Namibia , Child witnesses -- Zimbabwe , Child witnesses -- Ethiopia , Mediation -- Law and legislation -- South Africa , Mediation -- Law and legislation -- Namibia , Mediation -- Law and legislation -- Zimbabwe , Mediation -- Law and legislation -- Ethiopia , Children's rights -- South Africa , Children's rights -- Namibia , Children's rights -- Zimbabwe , Children's rights -- Ethiopia
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3698 , http://hdl.handle.net/10962/d1003213 , Juvenile courts -- South Africa , Juvenile courts -- Namibia , Juveline courts -- Zimbabwe , Juvenile courts -- Ethiopia , Children -- Legal status, laws, etc. -- South Africa , Children -- Legal status, laws, etc. -- Namibia , Children -- Legal status, laws, etc. -- Zimbabwe , Children -- Legal status, laws, etc. -- Ethiopia , Child witnesses -- South Africa , Child witnesses -- Namibia , Child witnesses -- Zimbabwe , Child witnesses -- Ethiopia , Mediation -- Law and legislation -- South Africa , Mediation -- Law and legislation -- Namibia , Mediation -- Law and legislation -- Zimbabwe , Mediation -- Law and legislation -- Ethiopia , Children's rights -- South Africa , Children's rights -- Namibia , Children's rights -- Zimbabwe , Children's rights -- Ethiopia
- Description: Prior to 1990, very few countries in the world offered special protection to child witnesses interfacing with the justice system. There were no legal provisions permitting testimonial accommodations for children in court. The courtroom experience was significantly traumatic for the children. With the international focus shifting from protecting and upholding the rights of the accused in the courtroom towards a more victim-centred approach, various international and regional instruments have strongly dvocated that children deserve special protection because of their vulnerability. In order for the courts to be able to elicit accurate evidence from the child without further traumatizing the child, research has shown that the child needs assistance. An intermediary may be defined as a person who facilitates communication between the child and the courtroom in a manner that takes into account the child‟s cognitive and developmental limitations. The thesis was prompted by the need to make a contribution to the currently limited body of literature on the intermediary systems in South Africa, Namibia, Zimbabwe and Ethiopia by investigating how the systems can be improved and sustained in a way that helps to protect the child witness in court. Despite the problems the South African courts have had in identifying the appropriate interpretation of its intermediary legislation, the country emerges as a clear leader for the steps it took by creating a positive legal framework within which child protection issues are addressed and introducing the concept of the intermediary. This concept proved to be an inspiration to its neighbours, Namibia and Zimbabwe. The influence of the South African intermediary legislation is evident in the Namibian and Zimbabwean legislation. Although Namibian legislators have drafted laws that permit intermediary assistance in court, there are as yet no intermediaries appointed. In Ethiopia, although there is no discernible intermediary legislation, the country has managed to establish an intermediary system. As a result of the analysis conducted, it is evident that the efficacy of the intermediary system is dependent on the presence of an enabling legislation, its clarity and ease of interpretation, the sensitisation of court role players on child vulnerabilities, the significance of intermediary assistance, and finally a government's commitment towards the implementation process.
- Full Text:
- Date Issued: 2011
A study of mathematics instructional practices in foundation phase grade three classrooms in East London
- Authors: Williams, Beverley Diana
- Date: 2011
- Subjects: Mathematics--Study and teaching (Primary) http://id.loc.gov/authorities/subjects/sh85082164 , Mathematics--Study and teaching (Elementary) http://id.loc.gov/authorities/subjects/sh85082163
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/19585 , vital:43146
- Description: This study describes the instructional practices of grade three teachers in their attempt to facilitate mathematical learning. The teachers’ practices are described in relation to the requirements of the revised National Curriculum Statement. In order to demarcate the field of investigation, the researcher provides an overview of the historical background of the study and draws attention to the knowledge interest of the investigation. The problem, the research questions, the assumptions of the study, the significance of the study, the rationale and the delimitation of the study are all set out in this chapter. A list of the major terms used in the study is also given. In concluding the chapter and outline of the issues discussed in each of the five chapters is given. , Thesis (MEd) -- University of Fort Hare, 2011
- Full Text:
- Date Issued: 2011
- Authors: Williams, Beverley Diana
- Date: 2011
- Subjects: Mathematics--Study and teaching (Primary) http://id.loc.gov/authorities/subjects/sh85082164 , Mathematics--Study and teaching (Elementary) http://id.loc.gov/authorities/subjects/sh85082163
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/19585 , vital:43146
- Description: This study describes the instructional practices of grade three teachers in their attempt to facilitate mathematical learning. The teachers’ practices are described in relation to the requirements of the revised National Curriculum Statement. In order to demarcate the field of investigation, the researcher provides an overview of the historical background of the study and draws attention to the knowledge interest of the investigation. The problem, the research questions, the assumptions of the study, the significance of the study, the rationale and the delimitation of the study are all set out in this chapter. A list of the major terms used in the study is also given. In concluding the chapter and outline of the issues discussed in each of the five chapters is given. , Thesis (MEd) -- University of Fort Hare, 2011
- Full Text:
- Date Issued: 2011
On the design and monitoring of photovoltaic systems for rural homes
- Authors: Williams, Nathaniel John
- Date: 2011
- Subjects: Photovoltaic cells , Dwellings -- Power supply
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10516 , http://hdl.handle.net/10948/1308 , Photovoltaic cells , Dwellings -- Power supply
- Description: It is estimated that 1.6 billion people today live without access to electricity. Most of these people live in remote rural areas in developing countries. One economic solution to this problem is the deployment of small domestic photovoltaic (PV) systems called solar home systems (SHS). In order to improve the performance and reduce the life cycle cost of these systems, accurate monitoring data of real SHSs is required. To this end, two SHSs typical of those found in the field were designed and installed, one in a rural area of the Eastern Cape of South Africa and the other in the laboratory. Monitoring systems were designed to record energy ows in the system and important environmental parameters. A novel technique was developed to correct for measurement errors occurring during the utilization of pulse width modulation charge control techniques. These errors were found to be as large as 47.6 percent. Simulations show that correction techniques produce measurement errors that are up to 20 times smaller than uncorrected values, depending upon the operating conditions. As a tool to aid in the analysis of monitoring data, a PV performance model was developed. The model, used to predict the maximum power point (MPP) power of a PV array, was able to predict MPP energy production to within 0.2 percent over the course of three days. Monitoring data from the laboratory system shows that the largest sources of energy loss are charge control, module under performance relative to manufacturer specifications and operation of the PV array away from MPP. These accounted for losses of approximately 18-27 percent, 15 percent and 8-11 percent of rated PV energy under standard test conditions, respectively. Energy consumed by loads on the systems was less than 50 percent of rated PV energy for both the remote and laboratory systems. Performance ratios (PR) for the laboratory system ranged from 0.38 to 0.49 for the three monitoring periods. The remote system produced a PR of 0.46. In both systems the PV arrays appear to have been oversized. This was due to overestimation of the energy requirements of the loads on the systems. In the laboratory system, the loads consisting of three compact fluorescent lamps and one incandescent lamp, were used to simulate a typical SHS load pro le and collectively consumed only 85 percent of their rated power. The 8 predicted load profile for the remote system proved to be signi cantly overestimated. The results of the monitoring project demonstrate the importance of acquiring an accurate estimation of the energy demand from loads on the system. Overestimations result in over-sized arrays and energy lost to charge control while under-sized systems risk damaging system batteries and load shedding. Significant under-performance of the PV module used in the laboratory system, underlines the importance of measuring module IV curves and verifying manufacturer specifications before system deployment. It was also found that signi cant PV array performance gains could be obtained by the use of maximum power point tracking charge controllers. Increased PV array performance leads to smaller arrays and reduced system cost.
- Full Text:
- Date Issued: 2011
- Authors: Williams, Nathaniel John
- Date: 2011
- Subjects: Photovoltaic cells , Dwellings -- Power supply
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10516 , http://hdl.handle.net/10948/1308 , Photovoltaic cells , Dwellings -- Power supply
- Description: It is estimated that 1.6 billion people today live without access to electricity. Most of these people live in remote rural areas in developing countries. One economic solution to this problem is the deployment of small domestic photovoltaic (PV) systems called solar home systems (SHS). In order to improve the performance and reduce the life cycle cost of these systems, accurate monitoring data of real SHSs is required. To this end, two SHSs typical of those found in the field were designed and installed, one in a rural area of the Eastern Cape of South Africa and the other in the laboratory. Monitoring systems were designed to record energy ows in the system and important environmental parameters. A novel technique was developed to correct for measurement errors occurring during the utilization of pulse width modulation charge control techniques. These errors were found to be as large as 47.6 percent. Simulations show that correction techniques produce measurement errors that are up to 20 times smaller than uncorrected values, depending upon the operating conditions. As a tool to aid in the analysis of monitoring data, a PV performance model was developed. The model, used to predict the maximum power point (MPP) power of a PV array, was able to predict MPP energy production to within 0.2 percent over the course of three days. Monitoring data from the laboratory system shows that the largest sources of energy loss are charge control, module under performance relative to manufacturer specifications and operation of the PV array away from MPP. These accounted for losses of approximately 18-27 percent, 15 percent and 8-11 percent of rated PV energy under standard test conditions, respectively. Energy consumed by loads on the systems was less than 50 percent of rated PV energy for both the remote and laboratory systems. Performance ratios (PR) for the laboratory system ranged from 0.38 to 0.49 for the three monitoring periods. The remote system produced a PR of 0.46. In both systems the PV arrays appear to have been oversized. This was due to overestimation of the energy requirements of the loads on the systems. In the laboratory system, the loads consisting of three compact fluorescent lamps and one incandescent lamp, were used to simulate a typical SHS load pro le and collectively consumed only 85 percent of their rated power. The 8 predicted load profile for the remote system proved to be signi cantly overestimated. The results of the monitoring project demonstrate the importance of acquiring an accurate estimation of the energy demand from loads on the system. Overestimations result in over-sized arrays and energy lost to charge control while under-sized systems risk damaging system batteries and load shedding. Significant under-performance of the PV module used in the laboratory system, underlines the importance of measuring module IV curves and verifying manufacturer specifications before system deployment. It was also found that signi cant PV array performance gains could be obtained by the use of maximum power point tracking charge controllers. Increased PV array performance leads to smaller arrays and reduced system cost.
- Full Text:
- Date Issued: 2011
Adoption and sustained use of M-Commerce to improve efficacy of construction SMMEs
- Authors: Williams, Zenande
- Date: 2011
- Subjects: Construction industry , Mobile commerce , Small business , Computer-assisted instruction , Interactive videos
- Language: English
- Type: Thesis , Masters , MCom (Information Systems)
- Identifier: vital:11125 , http://hdl.handle.net/10353/528 , Construction industry , Mobile commerce , Small business , Computer-assisted instruction , Interactive videos
- Description: E-commerce has been said to bring value to businesses by improving business efficiency and effectiveness and thus providing business with a competitive advantage through the potential benefits that it offers (Cloete, Courtney & Fintz, 2002). However, despite the potential benefits that e-commerce can offer, the adoption of B2C e-commerce in South African construction SMMEs is low and this is due to the challenges associated with e-commerce (Vaithanathan, 2010; Uzoka, Shemi & Seleka, 2007; Love & Irani, 2004; Anumba & Ruikar, 2002). These e-commerce challenges include: high implementation costs, lack or poor infrastructure, inadequate resources, low use of e-commerce by suppliers and consumers, lack of access to e-commerce, computer illiteracy, deficiency in understanding the potential benefits of e-commerce and security concerns (Vaithanathan, 2010; Uzoka, Shemi, & Seleka, 2007; Mensah, Bahta, & Mhlanga, 2005; Cloete, Courtney, & Fintz, 2002). Therefore, due to these e-commerce challenges, construction SMMEs do not exploit the business advantages that e-commerce offers. In order to assist South African construction SMMEs in their efforts to improve their business effectiveness and efficiency through commercial technologies.
- Full Text:
- Date Issued: 2011
- Authors: Williams, Zenande
- Date: 2011
- Subjects: Construction industry , Mobile commerce , Small business , Computer-assisted instruction , Interactive videos
- Language: English
- Type: Thesis , Masters , MCom (Information Systems)
- Identifier: vital:11125 , http://hdl.handle.net/10353/528 , Construction industry , Mobile commerce , Small business , Computer-assisted instruction , Interactive videos
- Description: E-commerce has been said to bring value to businesses by improving business efficiency and effectiveness and thus providing business with a competitive advantage through the potential benefits that it offers (Cloete, Courtney & Fintz, 2002). However, despite the potential benefits that e-commerce can offer, the adoption of B2C e-commerce in South African construction SMMEs is low and this is due to the challenges associated with e-commerce (Vaithanathan, 2010; Uzoka, Shemi & Seleka, 2007; Love & Irani, 2004; Anumba & Ruikar, 2002). These e-commerce challenges include: high implementation costs, lack or poor infrastructure, inadequate resources, low use of e-commerce by suppliers and consumers, lack of access to e-commerce, computer illiteracy, deficiency in understanding the potential benefits of e-commerce and security concerns (Vaithanathan, 2010; Uzoka, Shemi, & Seleka, 2007; Mensah, Bahta, & Mhlanga, 2005; Cloete, Courtney, & Fintz, 2002). Therefore, due to these e-commerce challenges, construction SMMEs do not exploit the business advantages that e-commerce offers. In order to assist South African construction SMMEs in their efforts to improve their business effectiveness and efficiency through commercial technologies.
- Full Text:
- Date Issued: 2011
The general and emotional development of a sample of South African children in residential care
- Authors: Wills, Nicolene
- Date: 2011
- Subjects: Children -- Institutional care -- South Africa , Child psychopathology -- Residential treatment -- South Africa , Children -- Services for -- South Africa , Child welfare -- South Africa , Child care services -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9856 , http://hdl.handle.net/10948/1578 , Children -- Institutional care -- South Africa , Child psychopathology -- Residential treatment -- South Africa , Children -- Services for -- South Africa , Child welfare -- South Africa , Child care services -- South Africa
- Description: The main aim of this study was to explore and describe the general and emotional development of a sample of South African children between the age of five and eight years in residential care. More specifically, the study aimed to explore and describe the general level of development of a sample of children in residential care; to explore and describe the development of a sample of children in residential care in six areas of development; and to describe the emotional wellbeing of children in residential care. A non-probability, purposive sampling method was applied as the participants were comprised of children between the ages of 5 and 8 years housed at the residential care facility. The sample consisted of 11 children. The multiple case study method was used to achieve the aim of the study, using both qualitative and quantitative data. The quantitative data consisted of scores obtained from the administration of the Griffiths Mental Development Scales - Extended Revised (GMDS-ER). The qualitative data was obtained from the Human Figure Drawing (HFD), participants’ scholastic progress reports, case reports from the residential care facility and clinical observations during the assessment period. The data was analysed according to thematic analysis. The results highlighted the pervasiveness of delays in all domains of child development of children housed in residential care, specifically that of language, social and emotional development. An important finding of the study was that decrements in these domains of development underpinned delays in the other domains of development since they form the foundation of learning and relating to the world. The study served to emphasize the importance of consistent developmental assessment in order to ascertain whether these children present with developmental delays and, if so, to xv identify which areas of development are most affected. Information from the developmental assessments could assist in the early identification of developmental delays and allow for individually tailored interventions to overcome such delays.
- Full Text:
- Date Issued: 2011
- Authors: Wills, Nicolene
- Date: 2011
- Subjects: Children -- Institutional care -- South Africa , Child psychopathology -- Residential treatment -- South Africa , Children -- Services for -- South Africa , Child welfare -- South Africa , Child care services -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9856 , http://hdl.handle.net/10948/1578 , Children -- Institutional care -- South Africa , Child psychopathology -- Residential treatment -- South Africa , Children -- Services for -- South Africa , Child welfare -- South Africa , Child care services -- South Africa
- Description: The main aim of this study was to explore and describe the general and emotional development of a sample of South African children between the age of five and eight years in residential care. More specifically, the study aimed to explore and describe the general level of development of a sample of children in residential care; to explore and describe the development of a sample of children in residential care in six areas of development; and to describe the emotional wellbeing of children in residential care. A non-probability, purposive sampling method was applied as the participants were comprised of children between the ages of 5 and 8 years housed at the residential care facility. The sample consisted of 11 children. The multiple case study method was used to achieve the aim of the study, using both qualitative and quantitative data. The quantitative data consisted of scores obtained from the administration of the Griffiths Mental Development Scales - Extended Revised (GMDS-ER). The qualitative data was obtained from the Human Figure Drawing (HFD), participants’ scholastic progress reports, case reports from the residential care facility and clinical observations during the assessment period. The data was analysed according to thematic analysis. The results highlighted the pervasiveness of delays in all domains of child development of children housed in residential care, specifically that of language, social and emotional development. An important finding of the study was that decrements in these domains of development underpinned delays in the other domains of development since they form the foundation of learning and relating to the world. The study served to emphasize the importance of consistent developmental assessment in order to ascertain whether these children present with developmental delays and, if so, to xv identify which areas of development are most affected. Information from the developmental assessments could assist in the early identification of developmental delays and allow for individually tailored interventions to overcome such delays.
- Full Text:
- Date Issued: 2011
Life history and population dynamics of invasive common carp, Cyprinus carpio, within a large turbid African impoundment
- Winker, A Henning, Weyl, Olaf L F, Booth, Anthony J, Ellender, Bruce R
- Authors: Winker, A Henning , Weyl, Olaf L F , Booth, Anthony J , Ellender, Bruce R
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124898 , vital:35708 , https://doi.10.1071/MF11054
- Description: Common carp (Cyprinus carpio) is one of the world’s most widely introduced and established freshwater fishes (Casal 2006). The species is considered to be one of the eight most invasive freshwater fishes (Lowe et al. 2000) and worldwide, it accounts for most of the records of successful establishments and adverse ecological effects (Casal 2006; Kulhanek et al. 2011). This invasive success suggests that feral C. carpio is equipped with a set of adaptable life history attributes that allow it to successfully colonise a wide range of habitats (Koehn 2004; Zambrano et al. 2006; Britton et al. 2007). Where feral C. carpio occurs in high densities, it is often perceived as an invasive pest species (Sivakumaran et al. 2003; Brown and Walker 2004; Koehn 2004) because it can have severe impacts on habitat heterogeneity and biodiversity by increasing water turbidity through its bottom feeding behaviour, increasing nutrient availability, decreasing benthic and macrophyte density and diversity, altering zooplankton assemblages and decreasing endemic fish abundance (Zambrano et al. 2001; Khan 2003; Kulhanek et al. 2011). Within south-east Australia, for example, C. carpio comprises the largest proportion of the ichthyobiomass in the continent’s largest river system – the Murray–Darling Basin (Gehrke et al. 1995). As a consequence, serious concerns about its threat to endemic freshwater species (Koehn 2004) have prompted several of the most recent investigations into its life history (e.g. Sivakumaran et al. 2003; Smith and Walker 2004; Brown et al. 2005). Other potential threats posed also include competition with indigenous species and the spread of diseases and parasites (Dudgeon et al. 2006). In South Africa, for example, Asian tapeworm Bothriocephalus acheilognathi is now widely distributed in seven river systems and has infected eight novel cyprinid hosts due to the translocation of infected by C. carpio from a centralized aquaculture facility (Stadtlander et al. 2011).
- Full Text:
- Date Issued: 2011
- Authors: Winker, A Henning , Weyl, Olaf L F , Booth, Anthony J , Ellender, Bruce R
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124898 , vital:35708 , https://doi.10.1071/MF11054
- Description: Common carp (Cyprinus carpio) is one of the world’s most widely introduced and established freshwater fishes (Casal 2006). The species is considered to be one of the eight most invasive freshwater fishes (Lowe et al. 2000) and worldwide, it accounts for most of the records of successful establishments and adverse ecological effects (Casal 2006; Kulhanek et al. 2011). This invasive success suggests that feral C. carpio is equipped with a set of adaptable life history attributes that allow it to successfully colonise a wide range of habitats (Koehn 2004; Zambrano et al. 2006; Britton et al. 2007). Where feral C. carpio occurs in high densities, it is often perceived as an invasive pest species (Sivakumaran et al. 2003; Brown and Walker 2004; Koehn 2004) because it can have severe impacts on habitat heterogeneity and biodiversity by increasing water turbidity through its bottom feeding behaviour, increasing nutrient availability, decreasing benthic and macrophyte density and diversity, altering zooplankton assemblages and decreasing endemic fish abundance (Zambrano et al. 2001; Khan 2003; Kulhanek et al. 2011). Within south-east Australia, for example, C. carpio comprises the largest proportion of the ichthyobiomass in the continent’s largest river system – the Murray–Darling Basin (Gehrke et al. 1995). As a consequence, serious concerns about its threat to endemic freshwater species (Koehn 2004) have prompted several of the most recent investigations into its life history (e.g. Sivakumaran et al. 2003; Smith and Walker 2004; Brown et al. 2005). Other potential threats posed also include competition with indigenous species and the spread of diseases and parasites (Dudgeon et al. 2006). In South Africa, for example, Asian tapeworm Bothriocephalus acheilognathi is now widely distributed in seven river systems and has infected eight novel cyprinid hosts due to the translocation of infected by C. carpio from a centralized aquaculture facility (Stadtlander et al. 2011).
- Full Text:
- Date Issued: 2011
Post-impoundment population dynamics of non-native common carp Cyprinus Carpio in relation to two large native cyprinids in Lake Gariep, South Africa
- Authors: Winker, Henning
- Date: 2011
- Subjects: Cyprinidae -- South Africa -- Gariep Dam Carp -- South Africa -- Gariep Dam Fish populations -- South Africa -- Gariep Dam Fishes -- Physiology -- South Africa -- Gariep Dam Barbus aeneus -- South Africa -- Gariep Dam Mudfishes -- South Africa -- Gariep Dam Freshwater fishes -- South Africa -- Gariep Dam
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5311 , http://hdl.handle.net/10962/d1005156
- Description: To contribute to the understanding of the invasion biology of common carp Cyprinus carpio in southern Africa, this thesis investigated the life history, relative abundance, long-term population demographics and trophic niche utilisations of non-native common carp C. carpio in relation to two endemic cyprinids, Orange River mudfish Labeo capensis and smallmouth yellowfish Labeobarbus aeneus in South Africa‟s largest impoundment, Lake Gariep. The growth zone deposition rates in astericus otoliths of the three species were validated as biannual for C. carpio and as annual for L. capensis and L. aeneus, which allowed for reliable estimation of lengths-at-age upon which growth, age-at-maturity and mortality rates could be estimated. Cyprinus carpio exhibited fast growth, matured relatively early at two years of age and attained a maximum age of seven years. Labeo capensis grew significantly slower, but attained older ages of up to 12 years. Females showed notably delayed maturation at approximately six years of age. The life history parameter estimates for L. aeneus were similar to those of L. capensis. These species-specific life history characteristics contributed to a substantially higher population growth potential of C. carpio compared to L. capensis and L. aeneus. Delta-lognormal and delta-gamma Generalized Linear Models (GLMs) were used to analyse patterns of relative abundance of L. capensis, L. aeneus and C. carpio. The application of these GLMs was necessary to account for large proportions of zeros and strong skewness in the catch-per-unit-effort (CPUE) from experimental gillnet and fisheries-dependent angler surveys. Confidence intervals around predicted abundance indices were obtained through the development of a generalised parametric bootstrap procedure. The resulting standardised abundance indices were coupled with results from analysis of stable isotope ratios of fish tissues and potential food resources and revealed that C. carpio was mainly confined to soft-bottom habitats, where it predominantly foraged on benthic invertebrates. Labeo capensis was abundant in a wide range of benthic habitats and was consumed basal food resources such as detritus. Labeobarbus aeneus was found to feed mostly on pelagic zooplankton. There were no significant interspecific differences in trophic niche space, suggesting limited resource competition among the three species. Standardised historical and contemporary gillnet CPUE data indicated slow population growth rates of L. capensis and L. aeneus during the first ten years postimpoundment, but showed high biomass levels some four decades after impoundment. These results could be corroborated by stochastic age-structured production model (ASPM) simulations. In contrast to the two endemic species, the gillnet CPUE of C. carpio showed a clear „boom and bust‟ pattern, which, based on ASPM simulations, could be best explained by increased food availability during the first five years postimpoundment, followed by suboptimal conditions thereafter. Together, these results provided evidence that the establishment of the C. carpio population did not prevent the slow but successful long-term establishment of the two large endemic cyprinids. Both endemic fishes revealed specialised feeding within the impoundment.
- Full Text:
- Date Issued: 2011
- Authors: Winker, Henning
- Date: 2011
- Subjects: Cyprinidae -- South Africa -- Gariep Dam Carp -- South Africa -- Gariep Dam Fish populations -- South Africa -- Gariep Dam Fishes -- Physiology -- South Africa -- Gariep Dam Barbus aeneus -- South Africa -- Gariep Dam Mudfishes -- South Africa -- Gariep Dam Freshwater fishes -- South Africa -- Gariep Dam
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5311 , http://hdl.handle.net/10962/d1005156
- Description: To contribute to the understanding of the invasion biology of common carp Cyprinus carpio in southern Africa, this thesis investigated the life history, relative abundance, long-term population demographics and trophic niche utilisations of non-native common carp C. carpio in relation to two endemic cyprinids, Orange River mudfish Labeo capensis and smallmouth yellowfish Labeobarbus aeneus in South Africa‟s largest impoundment, Lake Gariep. The growth zone deposition rates in astericus otoliths of the three species were validated as biannual for C. carpio and as annual for L. capensis and L. aeneus, which allowed for reliable estimation of lengths-at-age upon which growth, age-at-maturity and mortality rates could be estimated. Cyprinus carpio exhibited fast growth, matured relatively early at two years of age and attained a maximum age of seven years. Labeo capensis grew significantly slower, but attained older ages of up to 12 years. Females showed notably delayed maturation at approximately six years of age. The life history parameter estimates for L. aeneus were similar to those of L. capensis. These species-specific life history characteristics contributed to a substantially higher population growth potential of C. carpio compared to L. capensis and L. aeneus. Delta-lognormal and delta-gamma Generalized Linear Models (GLMs) were used to analyse patterns of relative abundance of L. capensis, L. aeneus and C. carpio. The application of these GLMs was necessary to account for large proportions of zeros and strong skewness in the catch-per-unit-effort (CPUE) from experimental gillnet and fisheries-dependent angler surveys. Confidence intervals around predicted abundance indices were obtained through the development of a generalised parametric bootstrap procedure. The resulting standardised abundance indices were coupled with results from analysis of stable isotope ratios of fish tissues and potential food resources and revealed that C. carpio was mainly confined to soft-bottom habitats, where it predominantly foraged on benthic invertebrates. Labeo capensis was abundant in a wide range of benthic habitats and was consumed basal food resources such as detritus. Labeobarbus aeneus was found to feed mostly on pelagic zooplankton. There were no significant interspecific differences in trophic niche space, suggesting limited resource competition among the three species. Standardised historical and contemporary gillnet CPUE data indicated slow population growth rates of L. capensis and L. aeneus during the first ten years postimpoundment, but showed high biomass levels some four decades after impoundment. These results could be corroborated by stochastic age-structured production model (ASPM) simulations. In contrast to the two endemic species, the gillnet CPUE of C. carpio showed a clear „boom and bust‟ pattern, which, based on ASPM simulations, could be best explained by increased food availability during the first five years postimpoundment, followed by suboptimal conditions thereafter. Together, these results provided evidence that the establishment of the C. carpio population did not prevent the slow but successful long-term establishment of the two large endemic cyprinids. Both endemic fishes revealed specialised feeding within the impoundment.
- Full Text:
- Date Issued: 2011
The efficacy and toxicological effects of aloe ferox mill. used in the management of constipation in Nkonkobe municipality of the Eastern Cape province, South Africa
- Authors: Wintola, Olubunmi Abosede A
- Date: 2011
- Subjects: Asphodelaceae -- South Africa -- Eastern Cape , Aloe -- South Africa -- Eastern Cape , Herbs -- Therapeutic use -- South Africa -- Eastern Cape , Medicinal plants -- South Africa -- Eastern Cape , Constipation -- South Africa -- Eastern Cape , Poisonous plants -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD (Ethnobotany)
- Identifier: vital:11882 , http://hdl.handle.net/10353/485 , Asphodelaceae -- South Africa -- Eastern Cape , Aloe -- South Africa -- Eastern Cape , Herbs -- Therapeutic use -- South Africa -- Eastern Cape , Medicinal plants -- South Africa -- Eastern Cape , Constipation -- South Africa -- Eastern Cape , Poisonous plants -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Eastern Cape
- Description: Herbal remedies are commonly used in developing countries for the treatment of various diseases, including constipation. The rationale for utilizing medicinal plants for the treatment of diseases rested largely on the belief that they are safe and free of side effects. However, there is limited scientific evidence on the safety and efficacy of these herbal medicines to back up their continued therapeutic application. Aloe ferox Mill. (Aspodelaceae), known as Cape aloe, locally called ikhala is a medicinal plant used by the people of the Eastern Cape Province for the treatment of gastrointestinal problems and constipation. The plant is a perennial shrub with thick succulent leaves bearing brown thorns on the margin and bright orange flowers arranged in oval lanceolate. It occurs in all weather in bush veld, road side, gardens and undisturbed places. According to the ethnomedicinal information, A. ferox is used as purgative. This research project was therefore designed to evaluate its ability in the treatment of constipation and to investigate its possible toxicological property. At the beginning of this programme, a survey of plants used for the treatment of constipation in Nkonkobe Municipality of the Eastern Cape Province was carried out using a questionnaire, which was administered to herbalists, traditional healers and rural dwellers. The study revealed 10 plant species from 8 families that are used for the treatment of constipation in the province. Four plants, Aloe ferox Mill, Boophone distischa L.f Herb, Alepidea amatybica Eckl and Artemisia afra Jacq, were repeatedly mentioned. Based on the frequency of usage, perceived efficacy and availability to the rural dwellers and the traditional healers, Aloe ferox was the most commonly used of the plants for the treatment of constipation. The plant was thus, chosen for the study. The invivo laxative effect of the aqueous extract of Aloe ferox in the treatment of loperamide-induced constipation in Wistar rats was investigated at varying concentrations. The leaf extract at all the dosages investigated (50, 100 and 200 mg/kg body weight) improved intestinal motility, increased fecal volume and normalized body weight in the constipated rats. This was an indication of its laxative properties. However, the laxative property of the herb at 200 mg/kg body weight of the extract showed best efficacy and compares favourably well with senokot, a standard laxative drug. These findings have therefore, lent scientific credence to the folkloric use of the herb by the people of the Eastern Cape of South Africa as a laxative agent. Toxicological evaluation of aqueous leaf extract of Aloe ferox in loperamide-induced constipation was studied at 50, 100, and 200 mg/kg body weight. The oral administration of the extracts did not show any significant effect on the liver and kidney body weight ratios as well as the kidney and liver function indices. The extracts, at all the dosages investigated, did not alter the levels of creatinine, uric acid, urea, calcium and potassium ions. Similarly, the levels of total protein, albumin, bilirubin and gamma glutamyl transferase (GGT) were not significantly different from the control. The plant extract appreciably normalized the elevated activities of alkaline phosphatase (ALP), alanine transaminase (ALT) and aspartate transaminase (AST) in the untreated constipated rats following treatment with the extract. The extract did not show a significant effect on the hematological parameters except for the increase in the lymphocyte count in the untreated constipated rats, which was attenuated after administering the herb. ThThe available evidence in this study suggests that A. ferox may be safe as an oral remedy for constipation. Generally, the effect of the extract compared favourably well with senokot, a recommended drug for the treatment of constipation. The antioxidant activities against 1, 1 diphenyl- 2 picrylhydrazl (DPPH), 2,2’ – azinobis [3- ethylbenzothiazoline -6- sulfonic acid] diammonium salt (ABTS), hydrogen peroxide (H2O2), Nitric oxide (NO), lipid peroxidation and the ferric reducing agents were investigated spectrophotometrically. Alkaloids, saponins, tannins, total phenols, flavonoids, flavonols and proanthocyanidin were also determined to assess their effects on the antioxidants activity of this plant. The phytochemical content of the ethanol and acetone extracts were consistently high compared to other solvents extracts. The level of tannins was not significant (P > 0.05) as compared with other solvent extracts. The free radical scavenging activity of the extracts was high even at lower concentrations (0.025 mg/ml) except in DPPH and lipid peroxidation. The ferric reducing potential of the extracts was concentration dependent and significantly different from Vitamin C and butylated hydroxytoluene (BHT) that were used as standard drugs. The present study showed a high level of scavenging activity of the leaf extracts of Aloe ferox in all the solvent extracts. Both ethanol and methanolic extract showed potent antioxidant activities than acetone and aqueous extracts. The study indicated that the leaf extracts of Aloe ferox might be a valuable source of natural antioxidant for both medicine and food industries. A. ferox leaf consists of the gel, latex and mesophyll layer; however, the main active constituents of the latex and the leaf exudate of Aloe ferox are anthraquinones which are believed to be responsible for the laxative property. The laxative compound in Aloe ferox leaf extract was isolated and characterized by extracting the plant material in methanol and extract suspended in distilled water. Partitioning was done with n-hexane, ethyl acetate and butanol respectively and was co-spotted with the over-the-counter (OTC) laxative drugs. This led to the successive column chromatography and thin layer chromatography (TLC) of the most active ethyl acetate fraction on silica gel with benzene/ethanol/ammonia hydroxide (BEA: 90:10:1), ethyl acetate/methanol/water (EMW: 40:5.4:5) and chloroform/ethyl acetate/formic acid (CEF: 50:40:10) as the mobile phase. The successive chromatograph and TLC afforded two compounds of Rf 0.420 (blue) and 0.831 (yellow) with the over-the-counter (OTC) drugs. These compounds were not totally elucidated due to their small quantity and instability. However, hydroxyl (OH) and carboxyl groups (COOH) was established as common to the extracted compounds, which might be responsible for the biological activity recorded for the plant extract.
- Full Text:
- Date Issued: 2011
- Authors: Wintola, Olubunmi Abosede A
- Date: 2011
- Subjects: Asphodelaceae -- South Africa -- Eastern Cape , Aloe -- South Africa -- Eastern Cape , Herbs -- Therapeutic use -- South Africa -- Eastern Cape , Medicinal plants -- South Africa -- Eastern Cape , Constipation -- South Africa -- Eastern Cape , Poisonous plants -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD (Ethnobotany)
- Identifier: vital:11882 , http://hdl.handle.net/10353/485 , Asphodelaceae -- South Africa -- Eastern Cape , Aloe -- South Africa -- Eastern Cape , Herbs -- Therapeutic use -- South Africa -- Eastern Cape , Medicinal plants -- South Africa -- Eastern Cape , Constipation -- South Africa -- Eastern Cape , Poisonous plants -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Eastern Cape
- Description: Herbal remedies are commonly used in developing countries for the treatment of various diseases, including constipation. The rationale for utilizing medicinal plants for the treatment of diseases rested largely on the belief that they are safe and free of side effects. However, there is limited scientific evidence on the safety and efficacy of these herbal medicines to back up their continued therapeutic application. Aloe ferox Mill. (Aspodelaceae), known as Cape aloe, locally called ikhala is a medicinal plant used by the people of the Eastern Cape Province for the treatment of gastrointestinal problems and constipation. The plant is a perennial shrub with thick succulent leaves bearing brown thorns on the margin and bright orange flowers arranged in oval lanceolate. It occurs in all weather in bush veld, road side, gardens and undisturbed places. According to the ethnomedicinal information, A. ferox is used as purgative. This research project was therefore designed to evaluate its ability in the treatment of constipation and to investigate its possible toxicological property. At the beginning of this programme, a survey of plants used for the treatment of constipation in Nkonkobe Municipality of the Eastern Cape Province was carried out using a questionnaire, which was administered to herbalists, traditional healers and rural dwellers. The study revealed 10 plant species from 8 families that are used for the treatment of constipation in the province. Four plants, Aloe ferox Mill, Boophone distischa L.f Herb, Alepidea amatybica Eckl and Artemisia afra Jacq, were repeatedly mentioned. Based on the frequency of usage, perceived efficacy and availability to the rural dwellers and the traditional healers, Aloe ferox was the most commonly used of the plants for the treatment of constipation. The plant was thus, chosen for the study. The invivo laxative effect of the aqueous extract of Aloe ferox in the treatment of loperamide-induced constipation in Wistar rats was investigated at varying concentrations. The leaf extract at all the dosages investigated (50, 100 and 200 mg/kg body weight) improved intestinal motility, increased fecal volume and normalized body weight in the constipated rats. This was an indication of its laxative properties. However, the laxative property of the herb at 200 mg/kg body weight of the extract showed best efficacy and compares favourably well with senokot, a standard laxative drug. These findings have therefore, lent scientific credence to the folkloric use of the herb by the people of the Eastern Cape of South Africa as a laxative agent. Toxicological evaluation of aqueous leaf extract of Aloe ferox in loperamide-induced constipation was studied at 50, 100, and 200 mg/kg body weight. The oral administration of the extracts did not show any significant effect on the liver and kidney body weight ratios as well as the kidney and liver function indices. The extracts, at all the dosages investigated, did not alter the levels of creatinine, uric acid, urea, calcium and potassium ions. Similarly, the levels of total protein, albumin, bilirubin and gamma glutamyl transferase (GGT) were not significantly different from the control. The plant extract appreciably normalized the elevated activities of alkaline phosphatase (ALP), alanine transaminase (ALT) and aspartate transaminase (AST) in the untreated constipated rats following treatment with the extract. The extract did not show a significant effect on the hematological parameters except for the increase in the lymphocyte count in the untreated constipated rats, which was attenuated after administering the herb. ThThe available evidence in this study suggests that A. ferox may be safe as an oral remedy for constipation. Generally, the effect of the extract compared favourably well with senokot, a recommended drug for the treatment of constipation. The antioxidant activities against 1, 1 diphenyl- 2 picrylhydrazl (DPPH), 2,2’ – azinobis [3- ethylbenzothiazoline -6- sulfonic acid] diammonium salt (ABTS), hydrogen peroxide (H2O2), Nitric oxide (NO), lipid peroxidation and the ferric reducing agents were investigated spectrophotometrically. Alkaloids, saponins, tannins, total phenols, flavonoids, flavonols and proanthocyanidin were also determined to assess their effects on the antioxidants activity of this plant. The phytochemical content of the ethanol and acetone extracts were consistently high compared to other solvents extracts. The level of tannins was not significant (P > 0.05) as compared with other solvent extracts. The free radical scavenging activity of the extracts was high even at lower concentrations (0.025 mg/ml) except in DPPH and lipid peroxidation. The ferric reducing potential of the extracts was concentration dependent and significantly different from Vitamin C and butylated hydroxytoluene (BHT) that were used as standard drugs. The present study showed a high level of scavenging activity of the leaf extracts of Aloe ferox in all the solvent extracts. Both ethanol and methanolic extract showed potent antioxidant activities than acetone and aqueous extracts. The study indicated that the leaf extracts of Aloe ferox might be a valuable source of natural antioxidant for both medicine and food industries. A. ferox leaf consists of the gel, latex and mesophyll layer; however, the main active constituents of the latex and the leaf exudate of Aloe ferox are anthraquinones which are believed to be responsible for the laxative property. The laxative compound in Aloe ferox leaf extract was isolated and characterized by extracting the plant material in methanol and extract suspended in distilled water. Partitioning was done with n-hexane, ethyl acetate and butanol respectively and was co-spotted with the over-the-counter (OTC) laxative drugs. This led to the successive column chromatography and thin layer chromatography (TLC) of the most active ethyl acetate fraction on silica gel with benzene/ethanol/ammonia hydroxide (BEA: 90:10:1), ethyl acetate/methanol/water (EMW: 40:5.4:5) and chloroform/ethyl acetate/formic acid (CEF: 50:40:10) as the mobile phase. The successive chromatograph and TLC afforded two compounds of Rf 0.420 (blue) and 0.831 (yellow) with the over-the-counter (OTC) drugs. These compounds were not totally elucidated due to their small quantity and instability. However, hydroxyl (OH) and carboxyl groups (COOH) was established as common to the extracted compounds, which might be responsible for the biological activity recorded for the plant extract.
- Full Text:
- Date Issued: 2011
Poverty alleviation and community participation towards development in Bahir-Dar, Amhara regional state, Ethiopia
- Authors: Worku, Askal Tilahun
- Date: 2011
- Subjects: Poverty -- Ethiopia , Poor -- Services for -- Ethiopia , Community development -- Ethiopia , Economic development projects -- Ethiopia , Political participation -- Ethiopia , Economic assistance, Domestic -- Ethiopia
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9143 , http://hdl.handle.net/10948/d1018801
- Description: The objective of the research was to assess the trends and forms of community participation to poverty alleviation in Bahir Dar town. The field study was limited to two projects, micro and small scale enterprise activities and credit service, however the finding and recommendation can be applied to all projects aimed to poverty alleviation and community self sustaining projects. In order to achieve the research objectives, a review of relevant literature was done. It began by reviewing definitions and concepts of poverty. The literature also over reviewed the importance of community participation to poverty alleviation efforts of a country and reviews the Ethiopian poverty reduction process. The literature further highlighted the role of community participation in achieving development goals. The data collection was done by means of focus group discussions complimented by face-to-face interviews. The data collected were analyzed thematically with the use of narrative summary and categorization in respect to the objective of the study. The findings of the study showed that there is low participation of community and therefore creating more opportunities for community participation activity and detailed study in the area is recommended.
- Full Text:
- Date Issued: 2011
- Authors: Worku, Askal Tilahun
- Date: 2011
- Subjects: Poverty -- Ethiopia , Poor -- Services for -- Ethiopia , Community development -- Ethiopia , Economic development projects -- Ethiopia , Political participation -- Ethiopia , Economic assistance, Domestic -- Ethiopia
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9143 , http://hdl.handle.net/10948/d1018801
- Description: The objective of the research was to assess the trends and forms of community participation to poverty alleviation in Bahir Dar town. The field study was limited to two projects, micro and small scale enterprise activities and credit service, however the finding and recommendation can be applied to all projects aimed to poverty alleviation and community self sustaining projects. In order to achieve the research objectives, a review of relevant literature was done. It began by reviewing definitions and concepts of poverty. The literature also over reviewed the importance of community participation to poverty alleviation efforts of a country and reviews the Ethiopian poverty reduction process. The literature further highlighted the role of community participation in achieving development goals. The data collection was done by means of focus group discussions complimented by face-to-face interviews. The data collected were analyzed thematically with the use of narrative summary and categorization in respect to the objective of the study. The findings of the study showed that there is low participation of community and therefore creating more opportunities for community participation activity and detailed study in the area is recommended.
- Full Text:
- Date Issued: 2011
'Iron on iron': modernism engaging apartheid in some South African railway poems
- Authors: Wright, Laurence
- Date: 2011
- Language: English
- Type: text , article
- Identifier: vital:7068 , http://hdl.handle.net/10962/d1007459 , https://doi.org/10.1080/00138398.2011.626177
- Description: preprint , Modernism tends to be criticised, internationally, as politically conservative. The objection is often valid, although the charge says little about the quality of artistic achievement involved. This article argues that the alliance between Modernism and political conservatism is by no means a necessary one, and that there are instances where modernist vision has been used to convey substantive political insight, effective social critique and solid resistance. To illustrate the contrast,the article juxtaposes the abstract Modernism associated with Ben Nicholson and World War 2, with a neglected strain of South African railway poetry which uses modernist techniques to effect a powerful critique of South Africa’s apartheid dispensation. The article sustains a distinction between universalising modernist art that requires ethical work from its audiences to achieve artistic completion, and art in which modernist vision performs the requisite ethical work within its own formal constraints. Four very different South African railway poems, by Dennis Brutus, John Hendrickse, Alan Paton, and Leonard Koza, are examined and contextualised to demonstrate ways in which a modernist vision has been used to portray the social disruptions caused by apartheid. Modernist techniques are used to turn railway experience into a metonym for massive social disruption,without betraying the social reality of the transport technology involved.
- Full Text:
- Date Issued: 2011
- Authors: Wright, Laurence
- Date: 2011
- Language: English
- Type: text , article
- Identifier: vital:7068 , http://hdl.handle.net/10962/d1007459 , https://doi.org/10.1080/00138398.2011.626177
- Description: preprint , Modernism tends to be criticised, internationally, as politically conservative. The objection is often valid, although the charge says little about the quality of artistic achievement involved. This article argues that the alliance between Modernism and political conservatism is by no means a necessary one, and that there are instances where modernist vision has been used to convey substantive political insight, effective social critique and solid resistance. To illustrate the contrast,the article juxtaposes the abstract Modernism associated with Ben Nicholson and World War 2, with a neglected strain of South African railway poetry which uses modernist techniques to effect a powerful critique of South Africa’s apartheid dispensation. The article sustains a distinction between universalising modernist art that requires ethical work from its audiences to achieve artistic completion, and art in which modernist vision performs the requisite ethical work within its own formal constraints. Four very different South African railway poems, by Dennis Brutus, John Hendrickse, Alan Paton, and Leonard Koza, are examined and contextualised to demonstrate ways in which a modernist vision has been used to portray the social disruptions caused by apartheid. Modernist techniques are used to turn railway experience into a metonym for massive social disruption,without betraying the social reality of the transport technology involved.
- Full Text:
- Date Issued: 2011
Elephants, compassion, and the largesse of literature
- Authors: Wylie, Dan
- Date: 2011
- Language: English
- Type: Text
- Identifier: vital:582 , http://hdl.handle.net/10962/d1018924
- Description: [From the text] Why is it that we do not raise a monument, a mausoleum, nor even a humble gravestone, to mark the death of every elephant? We habitually, even compulsively, do this for other humans, occasionally for treasured pets. Yet we do not do it for the most charismatic, gigantic, culturally resonant land animal we will ever encounter. Why not? Some possible answers. One: too much work. Another: we regard other animals as less conscious than ourselves; we are the only creatures who deserve to have our deaths so commemorated. A third: wild animals are part of wild ecosystems; it is ‘natural’ for them to die and to be reabsorbed namelessly back into those ecosystems. We humans, on the other hand, consider ourselves somehow separate from those ecosystems: we shield ourselves from ‘Nature’ with bricks and literatures while we live, with marble and epitaphs after we die.
- Full Text:
- Date Issued: 2011
- Authors: Wylie, Dan
- Date: 2011
- Language: English
- Type: Text
- Identifier: vital:582 , http://hdl.handle.net/10962/d1018924
- Description: [From the text] Why is it that we do not raise a monument, a mausoleum, nor even a humble gravestone, to mark the death of every elephant? We habitually, even compulsively, do this for other humans, occasionally for treasured pets. Yet we do not do it for the most charismatic, gigantic, culturally resonant land animal we will ever encounter. Why not? Some possible answers. One: too much work. Another: we regard other animals as less conscious than ourselves; we are the only creatures who deserve to have our deaths so commemorated. A third: wild animals are part of wild ecosystems; it is ‘natural’ for them to die and to be reabsorbed namelessly back into those ecosystems. We humans, on the other hand, consider ourselves somehow separate from those ecosystems: we shield ourselves from ‘Nature’ with bricks and literatures while we live, with marble and epitaphs after we die.
- Full Text:
- Date Issued: 2011
An investigation on how educators experience their workloads against the background of teacher shortage
- Authors: Xabanisa, X V
- Date: 2011
- Subjects: Teacher shortage -- Workload
- Language: English
- Type: Thesis , Masters , M Ed
- Identifier: vital:18415 , http://hdl.handle.net/11260/d1006570
- Description: An investigation on how educators experience their workloads against the background of teacher shortage. This research study seeks to explore educators’ experiences of the effects of educator shortage on the academic performance of Grade 12 learners in the Butterworth Education District, in the Eastern Cape Province of South Africa. The research study was a result of the South African literature in education which over- emphasises the poor quality of teacher development as though it is the only cause of the poor academic performance of learners in South African Senior Secondary Schools. For example, the Centre for Education Policy Development Evaluation and Management (CEPD) (2000, p.130) asserts that “Training for educators and managers has been spotlighted in the Curriculum Review Report”. Through this study the researcher wanted to explore other possible explanations for the poor academic performance of the Grade 12 learners in the Butterworth Education District. The research study seeks to investigate whether educator shortages in Senior Secondary Schools could be responsible for the poor academic performance of learners in Grade 12. It was imperative therefore to look into the views and experiences of educators in this regard, with the object of finding the extent of educator shortages in schools, and the possible measures to address the situation, if it is a reality in schools. Six schools were selected, with each providing five participants who made a sum of 30 educators who volunteered to participate in the study. The study was an interpretive survey, where the qualitative methodology was used. The data was collected using semi-structured interviews. A tape recorder was also used to ensure that participants were not misrepresented in the analysis and discussions of the findings. The data was presented, analysed and discussed according to the patterns and themes derived from the sub-research questions. It emerged from the study that there are educator shortages in most senior secondary schools in the Butterworth Education District. This was due to the policies and reports which were contrary to one another. Contradictory reports were produced by three highly respected research institutions the National Teacher Educator Audit (NTEA) there was an oversupply of educators in South African schools (Hofmeyr and Hall 1996). On the other hand the research was conducted by the Pre-Service Education and Training (PRESET) and In-service Educational Service and Training (INSET) published that there is serious educator shortage in South Africa. There was a lack of insight from the Management of the National Department of Education, together with the Provincial Managers of education. These managers of the DoE failed to note that the decisions that they had made in 1994, of ensuring that all learners between ages of 7 and 15 should be taken by parents to school, would negatively affect the future of education if it was not properly planned for. This call for all learners of the above mentioned ages to go to school was made in line with the South African Schools Act No. 84 0f 1996. The implication of the Governments call to send more learners to school, whether parents had money or not, was that more educators had to be employed in the future but that did not happen. Instead, a once-off policy of severance packages was implemented by the government, which led to a lot of good educators taking their packages and leaving the profession. Literature reveals that Teacher Training Colleges were closed at about the same time. The literature also reveals that before the closure of Teacher Training Colleges there was a challenge of redeployment which was also not properly planned, implemented and monitored by the Provincial Managers of the DoE. The study reveals that poor planning of this process led to overcrowded classrooms, a phenomenon which was further exacerbated by the fact that the salaries of Principals and the HoDs in schools were linked to the number of learners the school had admitted. This had its own ramification like schools over-admitting learners because it meant more money for the principals and Heads of Departments. The study has revealed serious consequences which emanated from the educator shortage as a result of overcrowded classes. The literature also reveal that educators get employed and use the profession of teaching as a stepping stone for better paying professions. According to Peltzer, et al. (2005, p.35) “around 21 000 educators were leaving the system annually, although up to 30% of these were temporary teachers.” South Africa faces challenges with its pool of available educators. One of these challenges is that of attracting new educators into the teaching profession and another is the challenge of how to retain those already in the system (DoE, 2005 p.13). In the event that there are teacher shortage in the system the DoE is using the available educators to teach larger classes than they are capable. This causes problems when these teachers have to teach outside their areas of specialization. These consequences include the fact that educators are teaching more than six classes a day, and educators are overloaded; they do not have sufficient time to provide individual attention to the learners, mark leaner assessments, provide feedback on time, or do remedial work. The study also revealed that most educators are suffering from burnout and stress due to too much workload. The study has also shown that educators work even on Saturdays and holidays to try to finish the syllabus. As a result, there are very few young stars who aspire to making education their career. More educators are changing their careers because they know that life is about improved standards of living. The question is: What is the use of having all the good policies aimed at improving the quality of teaching and learning if there are insufficient implementers (educators) of these policies in schools. The policies include School Based Assessment (SBA), Annual National Assessment (ANA), Systemic Evaluation, Common Tasks for Assessments (CATs), Whole School Evaluation (WSE) and the Integrated Quality Management Systems (IQMS). Recommendations have been proposed on the strategies that the DoE may employ to address the educator shortage in schools and the quality of education.
- Full Text:
- Date Issued: 2011
- Authors: Xabanisa, X V
- Date: 2011
- Subjects: Teacher shortage -- Workload
- Language: English
- Type: Thesis , Masters , M Ed
- Identifier: vital:18415 , http://hdl.handle.net/11260/d1006570
- Description: An investigation on how educators experience their workloads against the background of teacher shortage. This research study seeks to explore educators’ experiences of the effects of educator shortage on the academic performance of Grade 12 learners in the Butterworth Education District, in the Eastern Cape Province of South Africa. The research study was a result of the South African literature in education which over- emphasises the poor quality of teacher development as though it is the only cause of the poor academic performance of learners in South African Senior Secondary Schools. For example, the Centre for Education Policy Development Evaluation and Management (CEPD) (2000, p.130) asserts that “Training for educators and managers has been spotlighted in the Curriculum Review Report”. Through this study the researcher wanted to explore other possible explanations for the poor academic performance of the Grade 12 learners in the Butterworth Education District. The research study seeks to investigate whether educator shortages in Senior Secondary Schools could be responsible for the poor academic performance of learners in Grade 12. It was imperative therefore to look into the views and experiences of educators in this regard, with the object of finding the extent of educator shortages in schools, and the possible measures to address the situation, if it is a reality in schools. Six schools were selected, with each providing five participants who made a sum of 30 educators who volunteered to participate in the study. The study was an interpretive survey, where the qualitative methodology was used. The data was collected using semi-structured interviews. A tape recorder was also used to ensure that participants were not misrepresented in the analysis and discussions of the findings. The data was presented, analysed and discussed according to the patterns and themes derived from the sub-research questions. It emerged from the study that there are educator shortages in most senior secondary schools in the Butterworth Education District. This was due to the policies and reports which were contrary to one another. Contradictory reports were produced by three highly respected research institutions the National Teacher Educator Audit (NTEA) there was an oversupply of educators in South African schools (Hofmeyr and Hall 1996). On the other hand the research was conducted by the Pre-Service Education and Training (PRESET) and In-service Educational Service and Training (INSET) published that there is serious educator shortage in South Africa. There was a lack of insight from the Management of the National Department of Education, together with the Provincial Managers of education. These managers of the DoE failed to note that the decisions that they had made in 1994, of ensuring that all learners between ages of 7 and 15 should be taken by parents to school, would negatively affect the future of education if it was not properly planned for. This call for all learners of the above mentioned ages to go to school was made in line with the South African Schools Act No. 84 0f 1996. The implication of the Governments call to send more learners to school, whether parents had money or not, was that more educators had to be employed in the future but that did not happen. Instead, a once-off policy of severance packages was implemented by the government, which led to a lot of good educators taking their packages and leaving the profession. Literature reveals that Teacher Training Colleges were closed at about the same time. The literature also reveals that before the closure of Teacher Training Colleges there was a challenge of redeployment which was also not properly planned, implemented and monitored by the Provincial Managers of the DoE. The study reveals that poor planning of this process led to overcrowded classrooms, a phenomenon which was further exacerbated by the fact that the salaries of Principals and the HoDs in schools were linked to the number of learners the school had admitted. This had its own ramification like schools over-admitting learners because it meant more money for the principals and Heads of Departments. The study has revealed serious consequences which emanated from the educator shortage as a result of overcrowded classes. The literature also reveal that educators get employed and use the profession of teaching as a stepping stone for better paying professions. According to Peltzer, et al. (2005, p.35) “around 21 000 educators were leaving the system annually, although up to 30% of these were temporary teachers.” South Africa faces challenges with its pool of available educators. One of these challenges is that of attracting new educators into the teaching profession and another is the challenge of how to retain those already in the system (DoE, 2005 p.13). In the event that there are teacher shortage in the system the DoE is using the available educators to teach larger classes than they are capable. This causes problems when these teachers have to teach outside their areas of specialization. These consequences include the fact that educators are teaching more than six classes a day, and educators are overloaded; they do not have sufficient time to provide individual attention to the learners, mark leaner assessments, provide feedback on time, or do remedial work. The study also revealed that most educators are suffering from burnout and stress due to too much workload. The study has also shown that educators work even on Saturdays and holidays to try to finish the syllabus. As a result, there are very few young stars who aspire to making education their career. More educators are changing their careers because they know that life is about improved standards of living. The question is: What is the use of having all the good policies aimed at improving the quality of teaching and learning if there are insufficient implementers (educators) of these policies in schools. The policies include School Based Assessment (SBA), Annual National Assessment (ANA), Systemic Evaluation, Common Tasks for Assessments (CATs), Whole School Evaluation (WSE) and the Integrated Quality Management Systems (IQMS). Recommendations have been proposed on the strategies that the DoE may employ to address the educator shortage in schools and the quality of education.
- Full Text:
- Date Issued: 2011
Adherence to pre-selected infant feeding practices among mothers on the prevention of mother-to-child transmission (PMTCT) of HIV/AIDS programme in the Amathole region, Eastern Cape
- Authors: Yako, Elizabeth Matseliso
- Date: 2011
- Subjects: Child care -- South Africa -- Eastern Cape , Child health services -- South Africa -- Eastern Cape , Mother and infant -- South Africa -- Eastern Cape , Parenteral feeding of children -- South Africa -- Eastern Cape , Motherhood -- South Africa -- Eastern Cape , HIV infections -- Children -- Transmission -- Prevention , Maternal health services -- South Africa -- Eastern Cape , AIDS (Disease) in pregnancy -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Nursing Science)
- Identifier: vital:11891 , http://hdl.handle.net/10353/d1001091 , Child care -- South Africa -- Eastern Cape , Child health services -- South Africa -- Eastern Cape , Mother and infant -- South Africa -- Eastern Cape , Parenteral feeding of children -- South Africa -- Eastern Cape , Motherhood -- South Africa -- Eastern Cape , HIV infections -- Children -- Transmission -- Prevention , Maternal health services -- South Africa -- Eastern Cape , AIDS (Disease) in pregnancy -- South Africa -- Eastern Cape
- Description: Infant feeding in the context of HIV/AIDS poses a challenge among mothers. The implementation of UNICEF guidelines on infant feeding, which state that “when replacement feeding is acceptable, feasible, affordable, sustainable and safe, avoidance of all breastfeeding by HIV-infected mothers is recommended” (WHO, 2003:12) are not easy to meet. In more developed countries, where these criteria are met, almost all HIV-infected mothers have ceased to breast feed. Consequently, infants of mothers in these countries are less likely to be infected with HIV postnatally. In South Africa, more specifically in the Eastern Cape, infant feeding is a challenge as a number of UNICEF criteria cannot be met. The Eastern Cape is one of the poorest Provinces in South Africa, with a number of rural communities. Earlier studies have shown that, if mothers select either exclusive breast feeding or exclusive formula feeding, this reduces mother-to-child transmission of HIV. A limited number of studies on adherence to the method of infant feeding selected before delivery were found in the literature, hence the need for the current study. The purpose of the study was to explore adherence to exclusive breast feeding and exclusive formula feeding among mothers with HIV infection and to determine the problems that mothers may be facing in implementing their pre-selected methods.
- Full Text:
- Date Issued: 2011
- Authors: Yako, Elizabeth Matseliso
- Date: 2011
- Subjects: Child care -- South Africa -- Eastern Cape , Child health services -- South Africa -- Eastern Cape , Mother and infant -- South Africa -- Eastern Cape , Parenteral feeding of children -- South Africa -- Eastern Cape , Motherhood -- South Africa -- Eastern Cape , HIV infections -- Children -- Transmission -- Prevention , Maternal health services -- South Africa -- Eastern Cape , AIDS (Disease) in pregnancy -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Nursing Science)
- Identifier: vital:11891 , http://hdl.handle.net/10353/d1001091 , Child care -- South Africa -- Eastern Cape , Child health services -- South Africa -- Eastern Cape , Mother and infant -- South Africa -- Eastern Cape , Parenteral feeding of children -- South Africa -- Eastern Cape , Motherhood -- South Africa -- Eastern Cape , HIV infections -- Children -- Transmission -- Prevention , Maternal health services -- South Africa -- Eastern Cape , AIDS (Disease) in pregnancy -- South Africa -- Eastern Cape
- Description: Infant feeding in the context of HIV/AIDS poses a challenge among mothers. The implementation of UNICEF guidelines on infant feeding, which state that “when replacement feeding is acceptable, feasible, affordable, sustainable and safe, avoidance of all breastfeeding by HIV-infected mothers is recommended” (WHO, 2003:12) are not easy to meet. In more developed countries, where these criteria are met, almost all HIV-infected mothers have ceased to breast feed. Consequently, infants of mothers in these countries are less likely to be infected with HIV postnatally. In South Africa, more specifically in the Eastern Cape, infant feeding is a challenge as a number of UNICEF criteria cannot be met. The Eastern Cape is one of the poorest Provinces in South Africa, with a number of rural communities. Earlier studies have shown that, if mothers select either exclusive breast feeding or exclusive formula feeding, this reduces mother-to-child transmission of HIV. A limited number of studies on adherence to the method of infant feeding selected before delivery were found in the literature, hence the need for the current study. The purpose of the study was to explore adherence to exclusive breast feeding and exclusive formula feeding among mothers with HIV infection and to determine the problems that mothers may be facing in implementing their pre-selected methods.
- Full Text:
- Date Issued: 2011
A framework to evaluate usable security in online social networking
- Authors: Yeratziotis, Alexandros
- Date: 2011
- Subjects: Online social networks -- Security measures , Computer security , Data protection
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9807 , http://hdl.handle.net/10948/d1012933
- Description: It is commonly held in the literature that users find security and privacy difficult to comprehend. It is also acknowledged that most end-user applications and websites have built-in security and privacy features. Users are expected to interact with these in order to protect their personal information. However, security is generally a secondary goal for users. Considering the complexity associated with security in combination with the notion that it is not users’ primary task, it makes sense that users tend to ignore their security responsibilities. As a result, they make poor security-related decisions and, consequently, their personal information is at risk. Usable Security is the field that investigates these types of issue, focusing on the design of security and privacy features that are usable. In order to understand and appreciate the complexities that exist in the field of Usable Security, the research fields of Human-Computer Interaction and Information Security should be examined. Accordingly, the Information Security field is concerned with all aspects pertaining to the security and privacy of information, while the field of Human-Computer Interaction is concerned with the design, evaluation and implementation of interactive computing systems for human use. This research delivers a framework to evaluate Usable Security in online social networks. In this study, online social networks that are particular to the health domain were used as a case study and contributed to the development of a framework consisting of three components: a process, a validation tool and a Usable Security heuristic evaluation. There is no existing qualitative process that describes how one would develop and validate a heuristic evaluation. In this regard a heuristic evaluation is a usability inspection method that is used to evaluate the design of an interface for any usability violations in the field of Human-Computer Interaction. Therefore, firstly, a new process and a validation tool were required to be developed. Once this had been achieved, the process could then be followed to develop a new heuristic evaluation that is specific to Usable Security. In order to assess the validity of a new heuristic evaluation a validation tool is used. The development of tools that can improve the design of security and privacy features on end-user applications and websites in terms of their usability is critical, as this will ensure that the intended users experience them as usable and can utilise them effectively. The framework for evaluating Usable Security contributes to this objective in the context of online social networks.
- Full Text:
- Date Issued: 2011
- Authors: Yeratziotis, Alexandros
- Date: 2011
- Subjects: Online social networks -- Security measures , Computer security , Data protection
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9807 , http://hdl.handle.net/10948/d1012933
- Description: It is commonly held in the literature that users find security and privacy difficult to comprehend. It is also acknowledged that most end-user applications and websites have built-in security and privacy features. Users are expected to interact with these in order to protect their personal information. However, security is generally a secondary goal for users. Considering the complexity associated with security in combination with the notion that it is not users’ primary task, it makes sense that users tend to ignore their security responsibilities. As a result, they make poor security-related decisions and, consequently, their personal information is at risk. Usable Security is the field that investigates these types of issue, focusing on the design of security and privacy features that are usable. In order to understand and appreciate the complexities that exist in the field of Usable Security, the research fields of Human-Computer Interaction and Information Security should be examined. Accordingly, the Information Security field is concerned with all aspects pertaining to the security and privacy of information, while the field of Human-Computer Interaction is concerned with the design, evaluation and implementation of interactive computing systems for human use. This research delivers a framework to evaluate Usable Security in online social networks. In this study, online social networks that are particular to the health domain were used as a case study and contributed to the development of a framework consisting of three components: a process, a validation tool and a Usable Security heuristic evaluation. There is no existing qualitative process that describes how one would develop and validate a heuristic evaluation. In this regard a heuristic evaluation is a usability inspection method that is used to evaluate the design of an interface for any usability violations in the field of Human-Computer Interaction. Therefore, firstly, a new process and a validation tool were required to be developed. Once this had been achieved, the process could then be followed to develop a new heuristic evaluation that is specific to Usable Security. In order to assess the validity of a new heuristic evaluation a validation tool is used. The development of tools that can improve the design of security and privacy features on end-user applications and websites in terms of their usability is critical, as this will ensure that the intended users experience them as usable and can utilise them effectively. The framework for evaluating Usable Security contributes to this objective in the context of online social networks.
- Full Text:
- Date Issued: 2011
Comparative structural bioinformatics analysis of Bacillus amyloliquefaciens chemotaxis proteins within Bacillus subtilis group
- Yssel, Anna, Reva, Oleg, Tastan Bishop, Özlem
- Authors: Yssel, Anna , Reva, Oleg , Tastan Bishop, Özlem
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123966 , vital:35521 , https://doi.10.1007/s00253-011-3582-y
- Description: Chemotaxis is a process in which bacteria sense their chemical environment and move towards more favorable conditions. Since plant colonization by bacteria is a multifaceted process which requires a response to the complex chemical environment, a finely tuned and sensitive chemotaxis system is needed. Members of the Bacillus subtilis group including Bacillus amyloliquefaciens are industrially important, for example, as bio-pesticides. The group exhibits plant growth-promoting characteristics, with different specificity towards certain host plants. Therefore, we hypothesize that while the principal molecular mechanisms of bacterial chemotaxis may be conserved, the bacterial chemotaxis system may need an evolutionary tweaking to adapt it to specific requirements, particularly in the process of evolution of free-living soil organisms, towards plant colonization behaviour. To date, almost nothing is known about what parts of the chemotaxis proteins are subjected to positive amino acid substitutions, involved in adjusting the chemotaxis system of bacteria during speciation. In this novel study, positively selected and purified sites of chemotaxis proteins were calculated, and these residues were mapped onto homology models that were built for the chemotaxis proteins, in an attempt to understand the spatial evolution of the chemotaxis proteins. Various positively selected amino acids were identified in semi-conserved regions of the proteins away from the known active sites.
- Full Text:
- Date Issued: 2011
- Authors: Yssel, Anna , Reva, Oleg , Tastan Bishop, Özlem
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123966 , vital:35521 , https://doi.10.1007/s00253-011-3582-y
- Description: Chemotaxis is a process in which bacteria sense their chemical environment and move towards more favorable conditions. Since plant colonization by bacteria is a multifaceted process which requires a response to the complex chemical environment, a finely tuned and sensitive chemotaxis system is needed. Members of the Bacillus subtilis group including Bacillus amyloliquefaciens are industrially important, for example, as bio-pesticides. The group exhibits plant growth-promoting characteristics, with different specificity towards certain host plants. Therefore, we hypothesize that while the principal molecular mechanisms of bacterial chemotaxis may be conserved, the bacterial chemotaxis system may need an evolutionary tweaking to adapt it to specific requirements, particularly in the process of evolution of free-living soil organisms, towards plant colonization behaviour. To date, almost nothing is known about what parts of the chemotaxis proteins are subjected to positive amino acid substitutions, involved in adjusting the chemotaxis system of bacteria during speciation. In this novel study, positively selected and purified sites of chemotaxis proteins were calculated, and these residues were mapped onto homology models that were built for the chemotaxis proteins, in an attempt to understand the spatial evolution of the chemotaxis proteins. Various positively selected amino acids were identified in semi-conserved regions of the proteins away from the known active sites.
- Full Text:
- Date Issued: 2011