The constitutional right of access to social security
- Authors: Govindjee, Avinash
- Date: 2001
- Subjects: Social security -- Law and legislation -- South Africa , South Africa -- Social policy
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:11061 , http://hdl.handle.net/10948/280 , Social security -- Law and legislation -- South Africa , South Africa -- Social policy
- Description: The inclusion of the right of access to social security in the Constitution did not meet with wholehearted approval in South Africa. This right, however, is of vital importance for the future upliftment of the country. The present social security system is based upon a clear distinction between social assistance and social insurance. There is a gap in current social security provisions in that the unemployed middle aged individual is not covered. Unemployment itself is one of the greatest challenges obscuring the implementation of a comprehensive social security system. The Constitutional right is to have ‘access’ to social security and the amount of resources at the state’s disposal is directly related to increasing this right, although it is true that a number of available resources are misspent. The state must take reasonable legislative and other measures, within its available resources, to achieve the progressive realisation of the right of access to social security. The principles of solidarity and ubuntu must be cultivated so that national social development becomes a concern for all citizens. There are numerous problems facing South Africans in attaining the goal of access to social security – even if national social development does become a priority. Budgetary constraints, poverty, unemployment, HIV/Aids and foreigners are examples of these. By making social security a priority for everyone, existing ideas (almost all of which have merit) may be converted into long-term solutions for poverty and unemployment. Currently, numerous opportunities to salvage the situation are being overlooked as a result of the lack of a comprehensive and structured plan to better the access to social security. The constitutional right of access to social security is enforceable, although the jurisprudence in this field remains underdeveloped. Conditions are currently favourable, within the country and beyond its borders, for an imaginative and concerted attempt to be made to find potential solutions. It is possible for resources to be increased and for tax benefits to be incorporated for businesses which have the capacity to contribute. The issue of defence spending is controversial, but could hold the key to lowering unemployment. Should jobs be created, it is likely that they will initially be of a temporary nature. Consequently, provisions are needed to ensure some guarantee of income in the lacuna between when a job is lost and another found. Ultimately, one thing is certain: the constitutional right of access to social security will only be complete once the people who are recipients of this right make sacrifices and create corresponding duties for themselves to ensure that the next generation of inhabitants of this country are not facing similar problems. The state’s goal should be to ensure that the basic rights which all people enjoy in terms of the Constitution (in particular the other socio-economic rights) are guaranteed for the duration of their existence, even if the level of benefits received by such people is low.
- Full Text:
- Date Issued: 2001
- Authors: Govindjee, Avinash
- Date: 2001
- Subjects: Social security -- Law and legislation -- South Africa , South Africa -- Social policy
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:11061 , http://hdl.handle.net/10948/280 , Social security -- Law and legislation -- South Africa , South Africa -- Social policy
- Description: The inclusion of the right of access to social security in the Constitution did not meet with wholehearted approval in South Africa. This right, however, is of vital importance for the future upliftment of the country. The present social security system is based upon a clear distinction between social assistance and social insurance. There is a gap in current social security provisions in that the unemployed middle aged individual is not covered. Unemployment itself is one of the greatest challenges obscuring the implementation of a comprehensive social security system. The Constitutional right is to have ‘access’ to social security and the amount of resources at the state’s disposal is directly related to increasing this right, although it is true that a number of available resources are misspent. The state must take reasonable legislative and other measures, within its available resources, to achieve the progressive realisation of the right of access to social security. The principles of solidarity and ubuntu must be cultivated so that national social development becomes a concern for all citizens. There are numerous problems facing South Africans in attaining the goal of access to social security – even if national social development does become a priority. Budgetary constraints, poverty, unemployment, HIV/Aids and foreigners are examples of these. By making social security a priority for everyone, existing ideas (almost all of which have merit) may be converted into long-term solutions for poverty and unemployment. Currently, numerous opportunities to salvage the situation are being overlooked as a result of the lack of a comprehensive and structured plan to better the access to social security. The constitutional right of access to social security is enforceable, although the jurisprudence in this field remains underdeveloped. Conditions are currently favourable, within the country and beyond its borders, for an imaginative and concerted attempt to be made to find potential solutions. It is possible for resources to be increased and for tax benefits to be incorporated for businesses which have the capacity to contribute. The issue of defence spending is controversial, but could hold the key to lowering unemployment. Should jobs be created, it is likely that they will initially be of a temporary nature. Consequently, provisions are needed to ensure some guarantee of income in the lacuna between when a job is lost and another found. Ultimately, one thing is certain: the constitutional right of access to social security will only be complete once the people who are recipients of this right make sacrifices and create corresponding duties for themselves to ensure that the next generation of inhabitants of this country are not facing similar problems. The state’s goal should be to ensure that the basic rights which all people enjoy in terms of the Constitution (in particular the other socio-economic rights) are guaranteed for the duration of their existence, even if the level of benefits received by such people is low.
- Full Text:
- Date Issued: 2001
The specification and design of a prototype 2-D MPEG-4 authoring tool
- Authors: Viljoen, Deon Walter
- Date: 2003
- Subjects: MPEG (Video coding standard) , Digital video -- Standards , Multimedia systems
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11092 , http://hdl.handle.net/10948/d1015741 , MPEG (Video coding standard) , Digital video -- Standards , Multimedia systems
- Description: The purpose of this project was the specification, design and implementation of a prototype 2-D MPEG-4 authoring tool. A literature study was conducted of the MPEG-4 standard and multimedia authoring tools to determine the specification and design of a prototype 2- D MPEG-4 authoring tool. The specification and design was used as a basis for the implementation of a prototype 2-D MPEG-4 authoring tool that complies with the Complete 2-D Scene Graph Profile. The need for research into MPEG-4 authoring tools arose from the reported lack of knowledge of the MPEG-4 standard and the limited implementations of MPEG-4 authoring tools available to content authors. In order for MPEG-4 to reach its full potential, it will require authoring tools and content players that satisfy the needs of its users. The theoretical component of this dissertation included a literature study of the MPEG-4 standard and an investigation of relevant multimedia authoring systems. MPEG-4 was introduced as a standard that allows for the creation and streaming of interactive multimedia content at variable bit rates over high and low bandwidth connections. The requirements for the prototype 2-D MPEG-4 authoring system were documented and a prototype system satisfying the requirements was designed, implemented and evaluated. The evaluation of the prototype system showed that the system successfully satisfied all its requirements and that it provides the user with an easy to use and intuitive authoring tool. MPEG-4 has the potential to satisfy the increasing demand for innovative multimedia content on low bandwidth networks, including the Internet and mobile networks, as well as the need expressed by users to interact with multimedia content. This dissertation makes an important contribution to the understanding of the MPEG-4 standard, its functionality and the design of a 2-D MPEG-4 Authoring tool. Keywords: MPEG-4; MPEG-4 authoring; Binary Format for Scenes.
- Full Text:
- Date Issued: 2003
- Authors: Viljoen, Deon Walter
- Date: 2003
- Subjects: MPEG (Video coding standard) , Digital video -- Standards , Multimedia systems
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11092 , http://hdl.handle.net/10948/d1015741 , MPEG (Video coding standard) , Digital video -- Standards , Multimedia systems
- Description: The purpose of this project was the specification, design and implementation of a prototype 2-D MPEG-4 authoring tool. A literature study was conducted of the MPEG-4 standard and multimedia authoring tools to determine the specification and design of a prototype 2- D MPEG-4 authoring tool. The specification and design was used as a basis for the implementation of a prototype 2-D MPEG-4 authoring tool that complies with the Complete 2-D Scene Graph Profile. The need for research into MPEG-4 authoring tools arose from the reported lack of knowledge of the MPEG-4 standard and the limited implementations of MPEG-4 authoring tools available to content authors. In order for MPEG-4 to reach its full potential, it will require authoring tools and content players that satisfy the needs of its users. The theoretical component of this dissertation included a literature study of the MPEG-4 standard and an investigation of relevant multimedia authoring systems. MPEG-4 was introduced as a standard that allows for the creation and streaming of interactive multimedia content at variable bit rates over high and low bandwidth connections. The requirements for the prototype 2-D MPEG-4 authoring system were documented and a prototype system satisfying the requirements was designed, implemented and evaluated. The evaluation of the prototype system showed that the system successfully satisfied all its requirements and that it provides the user with an easy to use and intuitive authoring tool. MPEG-4 has the potential to satisfy the increasing demand for innovative multimedia content on low bandwidth networks, including the Internet and mobile networks, as well as the need expressed by users to interact with multimedia content. This dissertation makes an important contribution to the understanding of the MPEG-4 standard, its functionality and the design of a 2-D MPEG-4 Authoring tool. Keywords: MPEG-4; MPEG-4 authoring; Binary Format for Scenes.
- Full Text:
- Date Issued: 2003
The execution of the financial management function in small to medium-sized building contractors as a means of promoting business sustainability
- Authors: Bekker, Jakobus Petrus
- Date: 2004
- Subjects: Contractors' operation -- Finance , Construction industry -- Finance
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11004 , http://hdl.handle.net/10948/336 , Contractors' operation -- Finance , Construction industry -- Finance
- Description: The objective of this study was to investigate the extent to which small to medium-sized building contractors beneficially utilise the financial management function in their enterprises to improve and ensure business sustainability. Financial management focuses on the principles of decision-making, which requires action, without perfect knowledge of the outcome. To effectively execute the financial function, using the primary inputs in decision-making, financial management requires the ability to: understand and interpret financial statements and reports; make reasoned and objective decisions in controlling the operations of the enterprise; have a thorough knowledge of the internal functioning of the enterprise; and have a thorough knowledge of current and expected future economic conditions in the external environment. To do this, requires an effectively applied financial management function in the enterprises, which includes the utilisation of the financial management criteria to ensure business sustainability. However, without an appreciation of what financial management is, how important financial management is, and how financial management must be applied in the enterprise, small to medium-sized building contractors will find it difficult to effectively perform the financial management function and its different activities. It was therefore important to determine how well owners and construction managers of the average small to medium-sized building contractor deal with and utilise the financial management function in their enterprises. Consequently, a survey was carried out amongst small to medium-sized building contractors in the Nelson Mandela Metropolitan Municipal (NMMM) area, which revealed information that was used to come to certain conclusions: Firstly, it can be concluded that the financial management function is generally exercised superficially. This is supported by the responses of small to medium-sized building contractors, which implied that more than half the contractors do not fully perform financial management tasks. Secondly, it was concluded that the financial management criteria generally do not play a role in the business sustainability considerations of small to medium-sized building contractors. This is supported by the results, which imply that more than half the contractors do not fully utilise the financial management criteria.
- Full Text:
- Date Issued: 2004
- Authors: Bekker, Jakobus Petrus
- Date: 2004
- Subjects: Contractors' operation -- Finance , Construction industry -- Finance
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11004 , http://hdl.handle.net/10948/336 , Contractors' operation -- Finance , Construction industry -- Finance
- Description: The objective of this study was to investigate the extent to which small to medium-sized building contractors beneficially utilise the financial management function in their enterprises to improve and ensure business sustainability. Financial management focuses on the principles of decision-making, which requires action, without perfect knowledge of the outcome. To effectively execute the financial function, using the primary inputs in decision-making, financial management requires the ability to: understand and interpret financial statements and reports; make reasoned and objective decisions in controlling the operations of the enterprise; have a thorough knowledge of the internal functioning of the enterprise; and have a thorough knowledge of current and expected future economic conditions in the external environment. To do this, requires an effectively applied financial management function in the enterprises, which includes the utilisation of the financial management criteria to ensure business sustainability. However, without an appreciation of what financial management is, how important financial management is, and how financial management must be applied in the enterprise, small to medium-sized building contractors will find it difficult to effectively perform the financial management function and its different activities. It was therefore important to determine how well owners and construction managers of the average small to medium-sized building contractor deal with and utilise the financial management function in their enterprises. Consequently, a survey was carried out amongst small to medium-sized building contractors in the Nelson Mandela Metropolitan Municipal (NMMM) area, which revealed information that was used to come to certain conclusions: Firstly, it can be concluded that the financial management function is generally exercised superficially. This is supported by the responses of small to medium-sized building contractors, which implied that more than half the contractors do not fully perform financial management tasks. Secondly, it was concluded that the financial management criteria generally do not play a role in the business sustainability considerations of small to medium-sized building contractors. This is supported by the results, which imply that more than half the contractors do not fully utilise the financial management criteria.
- Full Text:
- Date Issued: 2004
Die bestuursrol van die skoolhoof in die implementering van 'n nuwe kurrikulum
- Authors: Mey, Hermanus Pieter
- Date: 2004
- Subjects: School principals -- South Africa , Educational leadership -- South Africa , Curriculum change -- South Africa
- Language: Afrikaans
- Type: Thesis , Masters , MPhil
- Identifier: vital:11010 , http://hdl.handle.net/10948/367 , School principals -- South Africa , Educational leadership -- South Africa , Curriculum change -- South Africa
- Description: The implementation of a new curriculum has become a very relevant issue in South Africa with the implementation of Curriculum 2005 (C 2005) since 1998. The school principal plays a very important role at school level in the implementation of change in general and a new curriculum in particular. The aim of this study was to have a closer look at this role. It is a qualitative study executed in six schools in the Port Elizabeth area. It investigates the problems school principals experienced with the implementation of C 2005 with the objective of identifying guidelines for the role of the principal in the implementation of a new curriculum The most important findings include the importance of equipping the principal to provide guidance with the implementation of a new curriculum. This equipping refers to the principal’s knowledge of the new curriculum, the ability to employ various leadership styles, as well as the maintenance of a certain balance between supporting and putting pressure on the staff. Other findings refer to the importance of well-trained and prepared facilitators of workshops, as well as the role the Department of Education needs to play in the training and preparation of these facilitators. The ongoing support of schools in the implementation process also needs to be emphasized. The principal should play a key role with respect to this last role of the Department. The study also emphasizes the principal’s responsibility to bind the educators together in building a shared vision, so that their focus will remain on the curriculum implementation.
- Full Text:
- Date Issued: 2004
- Authors: Mey, Hermanus Pieter
- Date: 2004
- Subjects: School principals -- South Africa , Educational leadership -- South Africa , Curriculum change -- South Africa
- Language: Afrikaans
- Type: Thesis , Masters , MPhil
- Identifier: vital:11010 , http://hdl.handle.net/10948/367 , School principals -- South Africa , Educational leadership -- South Africa , Curriculum change -- South Africa
- Description: The implementation of a new curriculum has become a very relevant issue in South Africa with the implementation of Curriculum 2005 (C 2005) since 1998. The school principal plays a very important role at school level in the implementation of change in general and a new curriculum in particular. The aim of this study was to have a closer look at this role. It is a qualitative study executed in six schools in the Port Elizabeth area. It investigates the problems school principals experienced with the implementation of C 2005 with the objective of identifying guidelines for the role of the principal in the implementation of a new curriculum The most important findings include the importance of equipping the principal to provide guidance with the implementation of a new curriculum. This equipping refers to the principal’s knowledge of the new curriculum, the ability to employ various leadership styles, as well as the maintenance of a certain balance between supporting and putting pressure on the staff. Other findings refer to the importance of well-trained and prepared facilitators of workshops, as well as the role the Department of Education needs to play in the training and preparation of these facilitators. The ongoing support of schools in the implementation process also needs to be emphasized. The principal should play a key role with respect to this last role of the Department. The study also emphasizes the principal’s responsibility to bind the educators together in building a shared vision, so that their focus will remain on the curriculum implementation.
- Full Text:
- Date Issued: 2004
A preliminary investigation into the patterns of performance on a computerized adaptive test battery implications for admissions and placement
- Authors: Vorster, Marlene
- Date: 2002
- Subjects: Universities and colleges -- Admission , Advanced placement programs (Education) , Computer adaptive testing , Universities and colleges -- Entrance requirements
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11030 , http://hdl.handle.net/10948/285 , Universities and colleges -- Admission , Advanced placement programs (Education) , Computer adaptive testing , Universities and colleges -- Entrance requirements
- Description: The fallibility of human judgment in the making of decisions requires the use of tests to enhance decision-making processes. Although testing is surrounded with issues of bias and fairness, it remains the best means of facilitating decisions over more subjective alternatives. As a country in transition, all facets of South African society are being transformed. The changes taking place within the tertiary education system to redress the legacy of Apartheid, coincide with an international trend of transforming higher education. One important area that is being transformed relates to university entrance requirements and admissions procedures. In South Africa, these were traditionally based on matriculation performance, which has been found to be a more variable predictor of academic success for historically disadvantaged students. Alternative or revised admissions procedures have been implemented at universities throughout the country, in conjunction with academic development programmes. However, it is argued in this dissertation that a paradigm shift is necessary to conceptualise admissions and placement assessment in a developmentally oriented way. Furthermore, it is motivated that it is important to keep abreast of advances in theory, such as item response theory (IRT) and technology, such as computerized adaptive testing (CAT), in test development to enhance the effectiveness of selecting and placing learners in tertiary programmes. This study focuses on investigating the use of the Accuplacer Computerized Placement Tests (CPTs), an adaptive test battery that was developed in the USA, to facilitate unbiased and fair admissions, placement and development decisions in the transforming South African context. The battery has been implemented at a university in the Eastern Cape and its usefulness was investigated for 193 participants, divided into two groups of degree programmes, depending on whether or not admission to the degree required mathematics as a matriculation subject. Mathematics based degree programme learners (n = 125) wrote three and non-mathematics based degree programme learners (n = 68) wrote two tests of the Accuplacer test battery. Correlations were computed between the Accuplacer scores and matriculation performance, and between the Accuplacer scores, matriculation performance and academic results. All yielded significant positive relationships excepting for the one subtest of the Accuplacer with academic performance for the non-mathematics based degree group. Multiple correlations for both groups indicated that the Accuplacer scores and matriculation results contribute unique information about academic performance. Cluster analysis for both groups yielded three underlying patterns of performance in the data sets. An attempt was made to validate the cluster groups internally through a MANOVA and single-factor ANOVAs. It was found that Accuplacer subtests and matriculation results do discriminate to an extent among clusters of learners in both groups of degree programmes investigated. Clusters were described in terms of demographic information and it was determined that the factors of culture and home language and how they relate to cluster group membership need further investigation. The main suggestion flowing from these findings is that an attempt be made to confirm the results with a larger sample size and for different cultural and language groups.
- Full Text:
- Date Issued: 2002
- Authors: Vorster, Marlene
- Date: 2002
- Subjects: Universities and colleges -- Admission , Advanced placement programs (Education) , Computer adaptive testing , Universities and colleges -- Entrance requirements
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11030 , http://hdl.handle.net/10948/285 , Universities and colleges -- Admission , Advanced placement programs (Education) , Computer adaptive testing , Universities and colleges -- Entrance requirements
- Description: The fallibility of human judgment in the making of decisions requires the use of tests to enhance decision-making processes. Although testing is surrounded with issues of bias and fairness, it remains the best means of facilitating decisions over more subjective alternatives. As a country in transition, all facets of South African society are being transformed. The changes taking place within the tertiary education system to redress the legacy of Apartheid, coincide with an international trend of transforming higher education. One important area that is being transformed relates to university entrance requirements and admissions procedures. In South Africa, these were traditionally based on matriculation performance, which has been found to be a more variable predictor of academic success for historically disadvantaged students. Alternative or revised admissions procedures have been implemented at universities throughout the country, in conjunction with academic development programmes. However, it is argued in this dissertation that a paradigm shift is necessary to conceptualise admissions and placement assessment in a developmentally oriented way. Furthermore, it is motivated that it is important to keep abreast of advances in theory, such as item response theory (IRT) and technology, such as computerized adaptive testing (CAT), in test development to enhance the effectiveness of selecting and placing learners in tertiary programmes. This study focuses on investigating the use of the Accuplacer Computerized Placement Tests (CPTs), an adaptive test battery that was developed in the USA, to facilitate unbiased and fair admissions, placement and development decisions in the transforming South African context. The battery has been implemented at a university in the Eastern Cape and its usefulness was investigated for 193 participants, divided into two groups of degree programmes, depending on whether or not admission to the degree required mathematics as a matriculation subject. Mathematics based degree programme learners (n = 125) wrote three and non-mathematics based degree programme learners (n = 68) wrote two tests of the Accuplacer test battery. Correlations were computed between the Accuplacer scores and matriculation performance, and between the Accuplacer scores, matriculation performance and academic results. All yielded significant positive relationships excepting for the one subtest of the Accuplacer with academic performance for the non-mathematics based degree group. Multiple correlations for both groups indicated that the Accuplacer scores and matriculation results contribute unique information about academic performance. Cluster analysis for both groups yielded three underlying patterns of performance in the data sets. An attempt was made to validate the cluster groups internally through a MANOVA and single-factor ANOVAs. It was found that Accuplacer subtests and matriculation results do discriminate to an extent among clusters of learners in both groups of degree programmes investigated. Clusters were described in terms of demographic information and it was determined that the factors of culture and home language and how they relate to cluster group membership need further investigation. The main suggestion flowing from these findings is that an attempt be made to confirm the results with a larger sample size and for different cultural and language groups.
- Full Text:
- Date Issued: 2002
The effect of selenium in the detoxification of the microcystin hepatotoxins
- Authors: Downs, Kerry
- Date: 2002
- Subjects: Cynaobacterial toxins , Microcystins , Selenium
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11070 , http://hdl.handle.net/10948/284 , Cynaobacterial toxins , Microcystins , Selenium
- Description: Blooms of cyanobacteria have been known to cause illness in humans and death in wild and domestic animals. One of the toxins produced by cyanobacteria is microcystin, which is a potent hepatotoxin. Microcystin is taken up by bile acid transporters in the intestine and transported into the liver. After exposure to acute doses of microcystin, severe haemorrhage has been observed along with apoptotic and necrotic hepatocytes. The cytoskeletal structure of the hepatocytes is disrupted and oxidative stress is induced. Selenium, a known anti-oxidant, has been shown to induce increased activity of glutathione peroxidase. Glutathione peroxidase removes peroxides from cells protecting them from oxidative stress. This study set out to determine if selenium could play a role in preventing the damage to mice livers due to microcystin toxin. The protective role of selenium was explored in three main studies: in the first study, the ability of selenium to increase the survival time of mice exposed to a lethal dose of toxin was determined. In the second study the mice were exposed to sublethal chronic doses of toxin over 30 days. The ability of selenium to minimise liver damage under these conditions was determined. The final study investigated the mechanism of the protective effect of selenium. The results of the first study suggested that selenium could extend survival time. In the second study the selenium supplemented mice showed a reduction in the extent of the increase in liver weight and a decrease in the amount of lipid peroxidation induced compared to the mice that received only toxin. The histology of the selenium supplemented mice also showed a decrease in the severity and amount of morphological changes in the liver. The third study indicated that the protection shown by selenium might be mediated by an increase in the glutathione peroxidase (GPX) activity in selenium supplemented mice. This increase in GPX activity would increase the removal of the lipid hydroperoxides and prevent the damage they would cause in the cell. A further result indicated an increase in glutathione S-transferase in only the toxin control mice when compared to the selenium supplemented and control mice. ii In conclusion selenium offers protection against microcystin but further studies need to be done to provide statistically valid results to clarify the level of protection.
- Full Text:
- Date Issued: 2002
- Authors: Downs, Kerry
- Date: 2002
- Subjects: Cynaobacterial toxins , Microcystins , Selenium
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11070 , http://hdl.handle.net/10948/284 , Cynaobacterial toxins , Microcystins , Selenium
- Description: Blooms of cyanobacteria have been known to cause illness in humans and death in wild and domestic animals. One of the toxins produced by cyanobacteria is microcystin, which is a potent hepatotoxin. Microcystin is taken up by bile acid transporters in the intestine and transported into the liver. After exposure to acute doses of microcystin, severe haemorrhage has been observed along with apoptotic and necrotic hepatocytes. The cytoskeletal structure of the hepatocytes is disrupted and oxidative stress is induced. Selenium, a known anti-oxidant, has been shown to induce increased activity of glutathione peroxidase. Glutathione peroxidase removes peroxides from cells protecting them from oxidative stress. This study set out to determine if selenium could play a role in preventing the damage to mice livers due to microcystin toxin. The protective role of selenium was explored in three main studies: in the first study, the ability of selenium to increase the survival time of mice exposed to a lethal dose of toxin was determined. In the second study the mice were exposed to sublethal chronic doses of toxin over 30 days. The ability of selenium to minimise liver damage under these conditions was determined. The final study investigated the mechanism of the protective effect of selenium. The results of the first study suggested that selenium could extend survival time. In the second study the selenium supplemented mice showed a reduction in the extent of the increase in liver weight and a decrease in the amount of lipid peroxidation induced compared to the mice that received only toxin. The histology of the selenium supplemented mice also showed a decrease in the severity and amount of morphological changes in the liver. The third study indicated that the protection shown by selenium might be mediated by an increase in the glutathione peroxidase (GPX) activity in selenium supplemented mice. This increase in GPX activity would increase the removal of the lipid hydroperoxides and prevent the damage they would cause in the cell. A further result indicated an increase in glutathione S-transferase in only the toxin control mice when compared to the selenium supplemented and control mice. ii In conclusion selenium offers protection against microcystin but further studies need to be done to provide statistically valid results to clarify the level of protection.
- Full Text:
- Date Issued: 2002
Jane Austen re-visited a feminist evaluation of the longevity and relevance of the Austen Oeuvre
- Authors: Kollmann, Elizabeth
- Date: 2003
- Subjects: Austen, Jane, 1775-1817 -- Criticism and interpretation , Feminist literary criticism
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10994 , http://hdl.handle.net/10948/299 , Austen, Jane, 1775-1817 -- Criticism and interpretation , Feminist literary criticism
- Description: Although many might consider Jane Austen to be outdated and clichéd, her work retains an undying appeal. During the last decade the English-speaking world has experienced an Austen renaissance as it has been treated to a number of film and television adaptations of her work, including Pride and Prejudice, Emma, Mansfield Park and Sense and Sensibility. Film critics such as Bill De Lapp (1996) and Sherry Dean (1996) have commented on the phenomenal response these productions received and have been amazed by Austen’s ability to compete with current movie scripts. The reasons for viewers and readers enjoying and identifying with Austen’s fiction are numerous. Readers of varying persuasions have different agendas and hence different views and interpretations of Austen. This thesis follows a gynocritical approach and applies a feminist point of view when reading and discussing Austen. Austen’s novels - Pride and Prejudice, Mansfield Park, Emma, Northanger Abbey, Sense and Sensibility, and Persuasion – are re-read and reevaluated from a feminist perspective in order to call attention to Austen’s awareness of women’s second-class position in her society. Women’s experiences in Austen’s time are compared to women’s experiences in society today in order to illustrate, in some way, the tremendous progress the feminist movement has made. In addition, by examining what Austen reveals about the material reality of women in her time, it is possible to explore the legacy that modern women have inherited. Literary critics such as André Brink (1998), Claudia Johnson (1988), and Gilbert and Gubar (1979) believe Austen to create feminist awareness in her novels. There are critics, however, who do not view Austen as necessarily feminist in her writing. Nancy Armstrong writes in Desire and Domestic Fiction (1987) that Austen’s objective is not a critique of the Abstract iv old order but rather a redefinition of wealth and status. In Culture and Imperialism (1993) Edward Said implicates Austen in the rationale for imperial expansion, while Barbara Seeber argues in “The Schooling of Marianne Dashwood” (1999) that Austen’s texts should be understood as dialogic. Others, such as Patricia Beer (1974), believe Austen’s fiction primarily to be about marriage since all her novels end with matrimony. My own reading of Austen takes into consideration her social milieu and patriarchal inheritance. It argues that Austen writes within the framework of patriarchy (for example by marrying off her heroines) possibly because she is aware that in order to survive as a woman (writer) in a male-favouring world and in a publishing world dominated by men, her critique needs to be covert. If read from a feminist perspective, Austen’s fiction draws our attention to issues such as women’s (lack of) education, the effects of not being given access to knowledge, marriage as a patriarchal institution of entrapment, and women’s identity. Her fiction reveals the effects of educating women for a life of domesticity, and illustrates that such an education is biased, leaving women powerless and without any means of self-protection in a male-dominated world. Although contemporary women in the Western world mostly enjoy equal education opportunities to men, they suffer the consequences of a legacy which denied them access to a proper education. Feminist writers such as Flis Henwood (2000) show that contemporary women believe certain areas of expertise belong to men exclusively. Others such as Linda Nochlin (1994) reveal that because women did not have access to higher education for so many years, they failed to produce great women artists like Chaucer or Cézanne. Austen’s fiction also exposes the economic and social system (of which education constitutes a major part) for enforcing marriage and for enfeebling women. In addition, it illustrates some of the realities and pitfalls of marriage. While Austen only subtly refers to Abstract v women’s disempowerment within marriage, contemporary feminist scholars such as Germaine Greer (1999) and Arnot, Araújo, Deliyanni, and Ivinson (2000) explicitly warn women that marriage is a patriarchal institution of entrapment and that it often leaves women feeling unfulfilled. The issue of marriage as a patriarchal institution has been thought important and has been addressed by feminists because it contributes to women’s powerlessness. Feminist scholars today find it imperative to expose all forms of power in order to eradicate women’s subordination. bell hooks comments in Feminist Theory: From Margin to Center (2000) on the importance of revealing unfair power relations in order to eliminate oppression of any kind. Austen does not necessarily express the wish to eradicate forms of power or oppression in her novels. Yet, if we read her work from a feminist point of view, we are made aware of the social construction of power. From her fiction we can infer that male power is enshrined in the very structure of society, and this makes us aware of women’s lack of power in her time. Austen’s novels, however, are not merely novels of powerlessness but of empowerment. By creating rounded women characters and by giving them the power to judge, to refuse and to write, Austen challenges the stereotyped view of woman as either overpowering monster or weak and fragile angel. In addition, her novels seem to question women’s inherited identity and to suggest that qualities such as emotionality and mothering are not natural aspects of being a woman. Because she suggests ways in which women might empower themselves, albeit within patriarchal parameters, one could argue that she contributes, in a small way, to the transformation of existing power relations and to the eradication of women’s servile position in society.
- Full Text:
- Date Issued: 2003
- Authors: Kollmann, Elizabeth
- Date: 2003
- Subjects: Austen, Jane, 1775-1817 -- Criticism and interpretation , Feminist literary criticism
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10994 , http://hdl.handle.net/10948/299 , Austen, Jane, 1775-1817 -- Criticism and interpretation , Feminist literary criticism
- Description: Although many might consider Jane Austen to be outdated and clichéd, her work retains an undying appeal. During the last decade the English-speaking world has experienced an Austen renaissance as it has been treated to a number of film and television adaptations of her work, including Pride and Prejudice, Emma, Mansfield Park and Sense and Sensibility. Film critics such as Bill De Lapp (1996) and Sherry Dean (1996) have commented on the phenomenal response these productions received and have been amazed by Austen’s ability to compete with current movie scripts. The reasons for viewers and readers enjoying and identifying with Austen’s fiction are numerous. Readers of varying persuasions have different agendas and hence different views and interpretations of Austen. This thesis follows a gynocritical approach and applies a feminist point of view when reading and discussing Austen. Austen’s novels - Pride and Prejudice, Mansfield Park, Emma, Northanger Abbey, Sense and Sensibility, and Persuasion – are re-read and reevaluated from a feminist perspective in order to call attention to Austen’s awareness of women’s second-class position in her society. Women’s experiences in Austen’s time are compared to women’s experiences in society today in order to illustrate, in some way, the tremendous progress the feminist movement has made. In addition, by examining what Austen reveals about the material reality of women in her time, it is possible to explore the legacy that modern women have inherited. Literary critics such as André Brink (1998), Claudia Johnson (1988), and Gilbert and Gubar (1979) believe Austen to create feminist awareness in her novels. There are critics, however, who do not view Austen as necessarily feminist in her writing. Nancy Armstrong writes in Desire and Domestic Fiction (1987) that Austen’s objective is not a critique of the Abstract iv old order but rather a redefinition of wealth and status. In Culture and Imperialism (1993) Edward Said implicates Austen in the rationale for imperial expansion, while Barbara Seeber argues in “The Schooling of Marianne Dashwood” (1999) that Austen’s texts should be understood as dialogic. Others, such as Patricia Beer (1974), believe Austen’s fiction primarily to be about marriage since all her novels end with matrimony. My own reading of Austen takes into consideration her social milieu and patriarchal inheritance. It argues that Austen writes within the framework of patriarchy (for example by marrying off her heroines) possibly because she is aware that in order to survive as a woman (writer) in a male-favouring world and in a publishing world dominated by men, her critique needs to be covert. If read from a feminist perspective, Austen’s fiction draws our attention to issues such as women’s (lack of) education, the effects of not being given access to knowledge, marriage as a patriarchal institution of entrapment, and women’s identity. Her fiction reveals the effects of educating women for a life of domesticity, and illustrates that such an education is biased, leaving women powerless and without any means of self-protection in a male-dominated world. Although contemporary women in the Western world mostly enjoy equal education opportunities to men, they suffer the consequences of a legacy which denied them access to a proper education. Feminist writers such as Flis Henwood (2000) show that contemporary women believe certain areas of expertise belong to men exclusively. Others such as Linda Nochlin (1994) reveal that because women did not have access to higher education for so many years, they failed to produce great women artists like Chaucer or Cézanne. Austen’s fiction also exposes the economic and social system (of which education constitutes a major part) for enforcing marriage and for enfeebling women. In addition, it illustrates some of the realities and pitfalls of marriage. While Austen only subtly refers to Abstract v women’s disempowerment within marriage, contemporary feminist scholars such as Germaine Greer (1999) and Arnot, Araújo, Deliyanni, and Ivinson (2000) explicitly warn women that marriage is a patriarchal institution of entrapment and that it often leaves women feeling unfulfilled. The issue of marriage as a patriarchal institution has been thought important and has been addressed by feminists because it contributes to women’s powerlessness. Feminist scholars today find it imperative to expose all forms of power in order to eradicate women’s subordination. bell hooks comments in Feminist Theory: From Margin to Center (2000) on the importance of revealing unfair power relations in order to eliminate oppression of any kind. Austen does not necessarily express the wish to eradicate forms of power or oppression in her novels. Yet, if we read her work from a feminist point of view, we are made aware of the social construction of power. From her fiction we can infer that male power is enshrined in the very structure of society, and this makes us aware of women’s lack of power in her time. Austen’s novels, however, are not merely novels of powerlessness but of empowerment. By creating rounded women characters and by giving them the power to judge, to refuse and to write, Austen challenges the stereotyped view of woman as either overpowering monster or weak and fragile angel. In addition, her novels seem to question women’s inherited identity and to suggest that qualities such as emotionality and mothering are not natural aspects of being a woman. Because she suggests ways in which women might empower themselves, albeit within patriarchal parameters, one could argue that she contributes, in a small way, to the transformation of existing power relations and to the eradication of women’s servile position in society.
- Full Text:
- Date Issued: 2003
Ostrich calpastatin purification and partial characterization of the liver inhibitor
- Authors: Roman, Henry James
- Date: 2000
- Subjects: Calpastatin , Protease inhibitors , Ion exchange chromatography , Ostriches
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11090 , http://hdl.handle.net/10948/d1015522
- Description: The isolation and purification of calpastatin from ostrich liver is presented, along with its physicochemical and kinetic properties. By using extraction from liver, ion-exchange chromatography on DEAE-Toyopearl, heating to 90 °C for 10 min and rechromatography on Toyopearl Super-Q 650 S, ostrich calpastatin was isolated and purified from ostrich liver. The purified intact calpastatin showed homogeneity on SDS-PAGE (Mr of 105.6 K). Amino acid analysis showed that ostrich calpastatin resembled that of rabbit liver and human erythrocyte calpastatin. An N-terminal sequence could not be obtained because the N-terminus was found to be blocked by an as yet unknown amino acid residue. The Mr values of degradative forms of ostrich liver calpastatin were determined to be 56 K and 90 K. By using PAG-IEF the pI of the intact form was determined to be 5.1. Ostrich liver calpastatin behaved characteristically like other calpastatins during kinetic analysis. Calpastatin inhibited calpain from pH 6 to 9 and was found to be unaffected by temperatures as high as 100 °C. Calpastatin also inhibited calpain activity at Ca2+ concentrations ranging from 1 to 10 mM. The inhibitor was shown to be phosphorylated because after incubation with alkaline phosphatase there was a decrease in inhibitory activity. No inhibitory effects were detected against other proteases such as chymotrypsin and trypsin, with both proteases inactivating calpastatin completely. Ostrich liver calpain was shown to have a pH optimum of 7.5 and a temperature optimum of 30 °C. In terms of its thermodynamic properties it resembled that of other ostrich proteases; DH, DS and DG being 47.07 kJ/mol, -91.1 J/mol/K and 74.237 kJ/mol, respectively. Ostrich liver calpain showed a Km of 0.14 % (w/v). The enzyme was active at both milli- and micro-molar concentrations of Ca2+. Ostrich liver calpastatin showed many physical, chemical and kinetic properties similar to those of other known calpastatins.
- Full Text: false
- Date Issued: 2000
- Authors: Roman, Henry James
- Date: 2000
- Subjects: Calpastatin , Protease inhibitors , Ion exchange chromatography , Ostriches
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11090 , http://hdl.handle.net/10948/d1015522
- Description: The isolation and purification of calpastatin from ostrich liver is presented, along with its physicochemical and kinetic properties. By using extraction from liver, ion-exchange chromatography on DEAE-Toyopearl, heating to 90 °C for 10 min and rechromatography on Toyopearl Super-Q 650 S, ostrich calpastatin was isolated and purified from ostrich liver. The purified intact calpastatin showed homogeneity on SDS-PAGE (Mr of 105.6 K). Amino acid analysis showed that ostrich calpastatin resembled that of rabbit liver and human erythrocyte calpastatin. An N-terminal sequence could not be obtained because the N-terminus was found to be blocked by an as yet unknown amino acid residue. The Mr values of degradative forms of ostrich liver calpastatin were determined to be 56 K and 90 K. By using PAG-IEF the pI of the intact form was determined to be 5.1. Ostrich liver calpastatin behaved characteristically like other calpastatins during kinetic analysis. Calpastatin inhibited calpain from pH 6 to 9 and was found to be unaffected by temperatures as high as 100 °C. Calpastatin also inhibited calpain activity at Ca2+ concentrations ranging from 1 to 10 mM. The inhibitor was shown to be phosphorylated because after incubation with alkaline phosphatase there was a decrease in inhibitory activity. No inhibitory effects were detected against other proteases such as chymotrypsin and trypsin, with both proteases inactivating calpastatin completely. Ostrich liver calpain was shown to have a pH optimum of 7.5 and a temperature optimum of 30 °C. In terms of its thermodynamic properties it resembled that of other ostrich proteases; DH, DS and DG being 47.07 kJ/mol, -91.1 J/mol/K and 74.237 kJ/mol, respectively. Ostrich liver calpain showed a Km of 0.14 % (w/v). The enzyme was active at both milli- and micro-molar concentrations of Ca2+. Ostrich liver calpastatin showed many physical, chemical and kinetic properties similar to those of other known calpastatins.
- Full Text: false
- Date Issued: 2000
The right to mother tongue education a multi-disciplinary, normative perspective
- Authors: Prinsloo, Dawn Lilian
- Date: 2005
- Subjects: Native language and education -- Government policy -- South Africa , Language and education -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10999 , http://hdl.handle.net/10948/365 , Native language and education -- Government policy -- South Africa , Language and education -- South Africa
- Description: The post-apartheid South African Constitution guarantees the children of this country “the right to receive education in the official language or languages of their choice in public education institutions where that education is reasonably practicable” (The Constitution of the Republic of South Africa, Act 108 of 1996, Section 29 (2)) (Juta’s Statutes 2003). Yet ten years into the new dispensation nothing significant has been done to alter a situation in which the majority of children are obliged to access their basic education largely through the medium of a second or even a third language — English. In contravention of both the intentions and the specific provisions of numerous legislative measures and policy statements, Government has made no serious or effective attempt to promote the use of any language other than English in South African schools nor to encourage language practices most conducive to the cognitive development and academic success of millions of non-English speaking pupils. To make matters worse, most of the children who enter the school system with very little knowledge of English and are expected to make an abrupt transition to that language as a medium of instruction after a totally inadequate three years are from impoverished households and communities still suffering the gravest effects of the discrimination and oppression of apartheid. They are often underprepared and seriously disadvantaged by their background circumstances when they enter the culturally strange and intimidating western-style education system. To heap on top of these disadvantages the burden of language practices in the classroom that hinder rather than facilitate their access to education is indefensible. When Macdonald asks, “ Are our children still swimming up the waterfall?” (Macdonald 2002: 111) she is not exaggerating. In these circumstances and if ineffective language teaching and inadequate use of the mother tongue as a medium of instruction can be shown to bar effective access to basic education of an acceptable standard, there are far more serious and far-reaching implications in terms of human rights than just the right to choice of language medium. Linguistic research into medium of instruction has tended to be isolated from evaluative legal approaches to minority language rights, children’s rights, education rights or other fundamental human rights. Insufficient attention has been given to the interrelationship between the various rights and the importance of local conditions and circumstances in any assessment of their relative weight and enforceability. Human rights cannot be seen out of context, and theory from various disciplines, such as politics, economics and linguistics may be invaluable in forming a fresh perspective on the right to mother tongue education and, indeed, to basic education in general. The principle of non-discrimination in education is generally recognised, to be sure, as is the importance of ensuring access to and quality of education (Strydom 1992/93:139), but the dependence of these factors on the most appropriate medium of instruction within the education system does not merit much attention in the literature. The right to basic education tends to be seen as separate from any possible right to choice of medium of instruction and the latter often merely as a question of convenience or preference, at best a qualified right (Oosthuizen and Rossouw 2001: 666), dependent on feasibility, numbers and available finance (Motata and Lemmer 2002: 111). In fact, the case for regarding the right to mother tongue education as a strong positive right in many contexts and countries does not appear yet to have been made. This study is theoretical in nature and constitutes an attempt to fill this gap by examining the findings and views of experts from various disciplines within the framework of current thinking on human rights issues. The development of a coherent framework within which to view the right to mother tongue education and government obligations in connection therewith might be of some value to policy makers in their efforts to plan improvements within the education system. The synthesis and possibly, to a limited extent, the development of theory from the relevant disciplines will be undertaken by means of a survey of the relevant literature, an analysis of not only local but also international legislation and policy documents and the weighing and balancing of conflicting evidence and contrasting viewpoints. Sources and contributions in each area will be discussed under the headings outlined in Chapter 3. First, however, I should like to provide an overview of the educational, political and economic context in which mother tongue education must be considered.
- Full Text:
- Date Issued: 2005
- Authors: Prinsloo, Dawn Lilian
- Date: 2005
- Subjects: Native language and education -- Government policy -- South Africa , Language and education -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10999 , http://hdl.handle.net/10948/365 , Native language and education -- Government policy -- South Africa , Language and education -- South Africa
- Description: The post-apartheid South African Constitution guarantees the children of this country “the right to receive education in the official language or languages of their choice in public education institutions where that education is reasonably practicable” (The Constitution of the Republic of South Africa, Act 108 of 1996, Section 29 (2)) (Juta’s Statutes 2003). Yet ten years into the new dispensation nothing significant has been done to alter a situation in which the majority of children are obliged to access their basic education largely through the medium of a second or even a third language — English. In contravention of both the intentions and the specific provisions of numerous legislative measures and policy statements, Government has made no serious or effective attempt to promote the use of any language other than English in South African schools nor to encourage language practices most conducive to the cognitive development and academic success of millions of non-English speaking pupils. To make matters worse, most of the children who enter the school system with very little knowledge of English and are expected to make an abrupt transition to that language as a medium of instruction after a totally inadequate three years are from impoverished households and communities still suffering the gravest effects of the discrimination and oppression of apartheid. They are often underprepared and seriously disadvantaged by their background circumstances when they enter the culturally strange and intimidating western-style education system. To heap on top of these disadvantages the burden of language practices in the classroom that hinder rather than facilitate their access to education is indefensible. When Macdonald asks, “ Are our children still swimming up the waterfall?” (Macdonald 2002: 111) she is not exaggerating. In these circumstances and if ineffective language teaching and inadequate use of the mother tongue as a medium of instruction can be shown to bar effective access to basic education of an acceptable standard, there are far more serious and far-reaching implications in terms of human rights than just the right to choice of language medium. Linguistic research into medium of instruction has tended to be isolated from evaluative legal approaches to minority language rights, children’s rights, education rights or other fundamental human rights. Insufficient attention has been given to the interrelationship between the various rights and the importance of local conditions and circumstances in any assessment of their relative weight and enforceability. Human rights cannot be seen out of context, and theory from various disciplines, such as politics, economics and linguistics may be invaluable in forming a fresh perspective on the right to mother tongue education and, indeed, to basic education in general. The principle of non-discrimination in education is generally recognised, to be sure, as is the importance of ensuring access to and quality of education (Strydom 1992/93:139), but the dependence of these factors on the most appropriate medium of instruction within the education system does not merit much attention in the literature. The right to basic education tends to be seen as separate from any possible right to choice of medium of instruction and the latter often merely as a question of convenience or preference, at best a qualified right (Oosthuizen and Rossouw 2001: 666), dependent on feasibility, numbers and available finance (Motata and Lemmer 2002: 111). In fact, the case for regarding the right to mother tongue education as a strong positive right in many contexts and countries does not appear yet to have been made. This study is theoretical in nature and constitutes an attempt to fill this gap by examining the findings and views of experts from various disciplines within the framework of current thinking on human rights issues. The development of a coherent framework within which to view the right to mother tongue education and government obligations in connection therewith might be of some value to policy makers in their efforts to plan improvements within the education system. The synthesis and possibly, to a limited extent, the development of theory from the relevant disciplines will be undertaken by means of a survey of the relevant literature, an analysis of not only local but also international legislation and policy documents and the weighing and balancing of conflicting evidence and contrasting viewpoints. Sources and contributions in each area will be discussed under the headings outlined in Chapter 3. First, however, I should like to provide an overview of the educational, political and economic context in which mother tongue education must be considered.
- Full Text:
- Date Issued: 2005
The influence of an adapted knee angle, as determined by isokinetic assessment, on sprint starting performance
- Authors: Schultz, Adrian Brent
- Date: 2004
- Subjects: Sprinting -- South Africa -- Physiological aspects -- Testing , Muscle strength -- Testing , Runners (Sports) -- South Africa -- Testing
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11029 , http://hdl.handle.net/10948/317 , Sprinting -- South Africa -- Physiological aspects -- Testing , Muscle strength -- Testing , Runners (Sports) -- South Africa -- Testing
- Description: Muscle strength has been identified as an important contributor to athletic performance. Little attention however, has been paid to the specific relationship between peak isokinetic muscle strength and sprint starting performance. The aim of this study was to determine the influence of an adapted front knee angle, as determined by isokinetic assessment (the angle of peak torque production), on starting performance. Sixteen track sprinters, of elite-national or competitive-regional standard, were asked to perform eight sprints over 50m using four separate starting techniques. Technique 1 featured the athlete’s usual starting preferences while Techniques 2, 3 and 4 featured a standardised set of starting preferences with experimental modifications of the front knee angle in the “set” position. Isokinetic muscle strength was measured at slow (60°/s) and fast (240°/s) test speeds in order to determine the angle of peak torque production for concentric knee extension of each subject’s lead leg. Using one-way analysis of variance (ANOVA) and Post Hoc analysis (LSD), no significant differences (p>0.05) were observed between the experimental techniques for: block time, force-time measures during block time, sprint times, sprint velocity and acceleratio n measures at intervals up to 50m. Significant differences (p<0.05) were however observed between reaction times for the experimental techniques. Slower reaction times are most likely due to increased upper body pretension, resulting from the increased hip elevation seen for these techniques. The results indicate that increased hip elevation may have delayed the initiation of the relevant motor response required to affect an optimal sprint start. Technique 1 resulted in the shortest reaction times, shortest block times, fastest sprint times and greatest sprint velocities for all four techniques. This result was possibly due to the athlete’s experience with, and repeated use of, this technique. The experimental techniques therefore provided no added advantage over the subject’s preferred starting technique and did not significantly optimise sprint starting performance. The results show that modification of the front knee angle had no significant influence on sprint starting performance and sprint running ve locity or acceleration patterns up to 50m. Using Pearson’s Correlation Coefficient to determine the strongest correlations between isokinetic knee strength and sprint starting performance, analysis revealed that the strongest relationships were found between sprint starting performance expressed as acceleration and isokinetic knee strength expressed as relative peak torque and absolute peak torque. For Technique 1 the strongest correlation was found between acceleration (30m - 40m) and relative peak torque as measured at a test speed of 240°/s (r = 0.62). For the remaining experimental techniques, the strongest correlation was found between acceleration (10m - 20m) and relative peak torque as measured at a test speed of 60°/s (r = 0.53) for Technique 2, between acceleration (40m - 50m) and peak torque measured at a test speed of 60°/s (r = 0.72) for Technique 3, and between acceleration (0m - 5m) and peak torque as measured at a test speed of 240°/s (r = 0.71) for Technique 4. These results suggest that isokinetic muscle strength does not correlate strongly with sprint starting performance and that additional factors, such as neuromuscular organisation and muscle fibre typing, possibly make a greater contribution to optimal sprint starting performance.
- Full Text:
- Date Issued: 2004
- Authors: Schultz, Adrian Brent
- Date: 2004
- Subjects: Sprinting -- South Africa -- Physiological aspects -- Testing , Muscle strength -- Testing , Runners (Sports) -- South Africa -- Testing
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11029 , http://hdl.handle.net/10948/317 , Sprinting -- South Africa -- Physiological aspects -- Testing , Muscle strength -- Testing , Runners (Sports) -- South Africa -- Testing
- Description: Muscle strength has been identified as an important contributor to athletic performance. Little attention however, has been paid to the specific relationship between peak isokinetic muscle strength and sprint starting performance. The aim of this study was to determine the influence of an adapted front knee angle, as determined by isokinetic assessment (the angle of peak torque production), on starting performance. Sixteen track sprinters, of elite-national or competitive-regional standard, were asked to perform eight sprints over 50m using four separate starting techniques. Technique 1 featured the athlete’s usual starting preferences while Techniques 2, 3 and 4 featured a standardised set of starting preferences with experimental modifications of the front knee angle in the “set” position. Isokinetic muscle strength was measured at slow (60°/s) and fast (240°/s) test speeds in order to determine the angle of peak torque production for concentric knee extension of each subject’s lead leg. Using one-way analysis of variance (ANOVA) and Post Hoc analysis (LSD), no significant differences (p>0.05) were observed between the experimental techniques for: block time, force-time measures during block time, sprint times, sprint velocity and acceleratio n measures at intervals up to 50m. Significant differences (p<0.05) were however observed between reaction times for the experimental techniques. Slower reaction times are most likely due to increased upper body pretension, resulting from the increased hip elevation seen for these techniques. The results indicate that increased hip elevation may have delayed the initiation of the relevant motor response required to affect an optimal sprint start. Technique 1 resulted in the shortest reaction times, shortest block times, fastest sprint times and greatest sprint velocities for all four techniques. This result was possibly due to the athlete’s experience with, and repeated use of, this technique. The experimental techniques therefore provided no added advantage over the subject’s preferred starting technique and did not significantly optimise sprint starting performance. The results show that modification of the front knee angle had no significant influence on sprint starting performance and sprint running ve locity or acceleration patterns up to 50m. Using Pearson’s Correlation Coefficient to determine the strongest correlations between isokinetic knee strength and sprint starting performance, analysis revealed that the strongest relationships were found between sprint starting performance expressed as acceleration and isokinetic knee strength expressed as relative peak torque and absolute peak torque. For Technique 1 the strongest correlation was found between acceleration (30m - 40m) and relative peak torque as measured at a test speed of 240°/s (r = 0.62). For the remaining experimental techniques, the strongest correlation was found between acceleration (10m - 20m) and relative peak torque as measured at a test speed of 60°/s (r = 0.53) for Technique 2, between acceleration (40m - 50m) and peak torque measured at a test speed of 60°/s (r = 0.72) for Technique 3, and between acceleration (0m - 5m) and peak torque as measured at a test speed of 240°/s (r = 0.71) for Technique 4. These results suggest that isokinetic muscle strength does not correlate strongly with sprint starting performance and that additional factors, such as neuromuscular organisation and muscle fibre typing, possibly make a greater contribution to optimal sprint starting performance.
- Full Text:
- Date Issued: 2004
Apollo, Dionysus, dialectical reason and critical cinema
- Authors: Konik, Adrian
- Date: 2003
- Subjects: Motion pictures and language , Philosophy in motion pictures , Dionysus (Greek deity) in literature , Apollo (Greek deity) in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10990 , http://hdl.handle.net/10948/295 , Motion pictures and language , Philosophy in motion pictures , Dionysus (Greek deity) in literature , Apollo (Greek deity) in literature
- Description: The contemporary era is dominated by an Apollonian visual language, i.e. the visual language of mainstream cinema and the mass media, and this study concerns the role that critical cinema, as Dionysian subverter, plays under such conditions. I argue that critical cinema should not be viewed as something completely ‘new’ but rather as a new, or at least the latest, manifestation of an older subversive ‘Dionysian’ voice that has made its presence felt since the dawn of the hegemony of an Apollonian disposition in Homeric epic. (I maintain that the history of western culture can be understood in terms of the persistent tension between Apollonian and Dionysian dispositions, and I use the distinction Derrida makes in Différance, between restricted and general economies, to distinguish between them, respectively.) I begin by considering the Dionysian echoes within Homer’s Iliad and then consider the way in which they became a ‘roar’ in the tragedies of Aeschylus. After Aeschylus a predominantly Apollonian voice asserted itself once again (to various degrees) through the work of Sophocles and Euripides. This was in keeping with the trend towards a more (Apollonian) restricted economy that is reflected in the writings of Homer’s literary successors, and which reached a crucial stage in Plato’s valorisation of ‘dialectics’, or what I term ‘dialecticis m’, which saw the birth of ‘dialectical language’. Through Plato dialecticism, or dialectical language, became instantiated as the ‘language’ of western philosophy and this predisposed western culture to develop along predominantly Apollonian lines. This continued from Plato, through the Middle Ages, until in the 17th century this Apollonian trend became manifest in the concept of the stable, integral, autonomous and self -transparent Cartesian ego, which is inextricably linked to dialectical language that promises certainty of ‘truth’ and maintains the possibility of representing the world in its entirety (as a system). In the contemporary ‘age of a world picture’, the hegemonic (Apollonian) visual language of mainstream cinema and the mass media propagates and perpetuates the belief in the possibility of representing the world in its entirety through the image, and insofar as it caters to audiences’ needs for stability and certainty (of ‘truth’) through providing such ‘complete’ representations, shapes their subjectivity along the lines of the Cartesian ego. According to Baudrillard, in contemporary society and culture the hyperreal realm of visual language has become far more significant for individuals than their immediate, empirical experiences, and that, as a result, they are far less predisposed to discussion and reflection and far more prone to passive ‘watching’. Also, Adorno maintains that it is impossible to have a form of critical cinema because of the way in which features inherent to cinema predispose it towards being an ideological apparatus. However, if both Baudrillard and Adorno are correct then the future appears increasingly bleak as it involves nothing other than the continuation and propagation of the hegemony of the visual language of mainstream cinema and the mass media, with no possibility for critical resistance. I argue instead that critical cinema is possible because the move towards a more restricted economy, motivated by an Apollonian disposition, did not develop from Homer to the contemporary era without meeting Dionysian resistance. I trace the presence of a subversive Dionysian voice through Homer’s Iliad, through Aeschylus’ Prometheus Bound, and through Plato’s Dialogues, where it echoes in the sentiments of some of Plato’s interlocutors, such as Callicles. In addition, I maintain that a ‘Dionysian’ voice resonates through both Nietzsche’s and Heidegger’s respective criticisms of ‘dialectical language’ and the ‘validity’ of the Cartesian ego. I argue that critical cinema, particularly Aronofsky’s postmodern critical cinema, parallels their similar epistemological and ontological perspectives in the way in which it engages with the (Apollonian) visual language of mainstream cinema and the mass media, and thereby, potentially, facilitates a more porous and protean subjectivity.
- Full Text:
- Date Issued: 2003
- Authors: Konik, Adrian
- Date: 2003
- Subjects: Motion pictures and language , Philosophy in motion pictures , Dionysus (Greek deity) in literature , Apollo (Greek deity) in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10990 , http://hdl.handle.net/10948/295 , Motion pictures and language , Philosophy in motion pictures , Dionysus (Greek deity) in literature , Apollo (Greek deity) in literature
- Description: The contemporary era is dominated by an Apollonian visual language, i.e. the visual language of mainstream cinema and the mass media, and this study concerns the role that critical cinema, as Dionysian subverter, plays under such conditions. I argue that critical cinema should not be viewed as something completely ‘new’ but rather as a new, or at least the latest, manifestation of an older subversive ‘Dionysian’ voice that has made its presence felt since the dawn of the hegemony of an Apollonian disposition in Homeric epic. (I maintain that the history of western culture can be understood in terms of the persistent tension between Apollonian and Dionysian dispositions, and I use the distinction Derrida makes in Différance, between restricted and general economies, to distinguish between them, respectively.) I begin by considering the Dionysian echoes within Homer’s Iliad and then consider the way in which they became a ‘roar’ in the tragedies of Aeschylus. After Aeschylus a predominantly Apollonian voice asserted itself once again (to various degrees) through the work of Sophocles and Euripides. This was in keeping with the trend towards a more (Apollonian) restricted economy that is reflected in the writings of Homer’s literary successors, and which reached a crucial stage in Plato’s valorisation of ‘dialectics’, or what I term ‘dialecticis m’, which saw the birth of ‘dialectical language’. Through Plato dialecticism, or dialectical language, became instantiated as the ‘language’ of western philosophy and this predisposed western culture to develop along predominantly Apollonian lines. This continued from Plato, through the Middle Ages, until in the 17th century this Apollonian trend became manifest in the concept of the stable, integral, autonomous and self -transparent Cartesian ego, which is inextricably linked to dialectical language that promises certainty of ‘truth’ and maintains the possibility of representing the world in its entirety (as a system). In the contemporary ‘age of a world picture’, the hegemonic (Apollonian) visual language of mainstream cinema and the mass media propagates and perpetuates the belief in the possibility of representing the world in its entirety through the image, and insofar as it caters to audiences’ needs for stability and certainty (of ‘truth’) through providing such ‘complete’ representations, shapes their subjectivity along the lines of the Cartesian ego. According to Baudrillard, in contemporary society and culture the hyperreal realm of visual language has become far more significant for individuals than their immediate, empirical experiences, and that, as a result, they are far less predisposed to discussion and reflection and far more prone to passive ‘watching’. Also, Adorno maintains that it is impossible to have a form of critical cinema because of the way in which features inherent to cinema predispose it towards being an ideological apparatus. However, if both Baudrillard and Adorno are correct then the future appears increasingly bleak as it involves nothing other than the continuation and propagation of the hegemony of the visual language of mainstream cinema and the mass media, with no possibility for critical resistance. I argue instead that critical cinema is possible because the move towards a more restricted economy, motivated by an Apollonian disposition, did not develop from Homer to the contemporary era without meeting Dionysian resistance. I trace the presence of a subversive Dionysian voice through Homer’s Iliad, through Aeschylus’ Prometheus Bound, and through Plato’s Dialogues, where it echoes in the sentiments of some of Plato’s interlocutors, such as Callicles. In addition, I maintain that a ‘Dionysian’ voice resonates through both Nietzsche’s and Heidegger’s respective criticisms of ‘dialectical language’ and the ‘validity’ of the Cartesian ego. I argue that critical cinema, particularly Aronofsky’s postmodern critical cinema, parallels their similar epistemological and ontological perspectives in the way in which it engages with the (Apollonian) visual language of mainstream cinema and the mass media, and thereby, potentially, facilitates a more porous and protean subjectivity.
- Full Text:
- Date Issued: 2003
An analysis of group adverse impact in selection strategies of a communications company
- Authors: Bradfield, Claire Caroline
- Date: 2004
- Subjects: Telecommunication -- Employees -- Selection and appointment -- South Africa , Employee selection -- South Africa , Discrimination in employment -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10993 , http://hdl.handle.net/10948/361 , Telecommunication -- Employees -- Selection and appointment -- South Africa , Employee selection -- South Africa , Discrimination in employment -- South Africa
- Description: An overview of the literature indicates that there is a real and pressing need to explore the concept of adverse impact in more detail. The Employment Equity Act of 1998 prioritises the issue of group representivity in staff selection and although there are merits in enforcing an Affirmative Action policy, an objective assessment of the inherent requirements of job applicants is still a constitutional and procedural outcome. There is no simple mechanism that can be used to determine the manifestation of adverse impact. However, evidence thereof can be most useful in securing fairness in selection and employment decisions. There is a distinct need to examine the matter of adverse impact and its implications in the South African context. South Africa is confronted with a labour force that is growing dramatically and changing significantly. The demographic trends in our dynamically changing labour markets are likely to amplify skill and ability differences between the resulting contradictory goals of equal opportunity based on individual merit and equal employment results for subgroups of populations. Three selection strategies of a communications company were used as a basis for the assessment of adverse impact. The total population of the Call Centre selection strategy was 150. Seven instruments and measures were utilised in the study, namely, a job analysis, pre-screening exercise, psychometric ability tests, role-play simulation, structured interview, job compatibility questionnaire and a performance evaluation. The total population of the Operator Services selection strategy was 139. Five psychometric instruments were utilised in the study. The total population of the Female Leadership Development Programme selection strategy was 471. Three psychometric instruments were utilised in the study. The Adverse Impact Model was applied to each of the aforementioned strategies. In terms of the definition, adverse impact exists if the selection ratio associated with a particular passing score on a test for one sub-group of job applicants is less than 4/5th’s or 80% of the selection ration for the largest sub-group of applicants. 13 The results of the study indicate that adverse impact occurred in the following instances. In the Call Centre selection strategy, there was evidence of adverse impact in the racial analysis in the ability testing stage. There was also evidence of adverse impact in the gender analysis during this stage. There was no evidence of adverse impact in either the racial or gender analyses during the interview stage. There was no evidence of adverse impact in the racial analysis during the appointment stage. There was however evidence of adverse impact in the gender analysis during the appointment stage. The Female Leadership Development Programme selection strategy revealed evidence of adverse impact in the racial analysis during the appointment stage. The Operator Services selection strategy revealed an adverse impact in both the racial and gender analyses during the testing stage. The issue of adverse impact is obviously controversial. However, data obtained from this process will provide for informative analysis.
- Full Text:
- Date Issued: 2004
- Authors: Bradfield, Claire Caroline
- Date: 2004
- Subjects: Telecommunication -- Employees -- Selection and appointment -- South Africa , Employee selection -- South Africa , Discrimination in employment -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10993 , http://hdl.handle.net/10948/361 , Telecommunication -- Employees -- Selection and appointment -- South Africa , Employee selection -- South Africa , Discrimination in employment -- South Africa
- Description: An overview of the literature indicates that there is a real and pressing need to explore the concept of adverse impact in more detail. The Employment Equity Act of 1998 prioritises the issue of group representivity in staff selection and although there are merits in enforcing an Affirmative Action policy, an objective assessment of the inherent requirements of job applicants is still a constitutional and procedural outcome. There is no simple mechanism that can be used to determine the manifestation of adverse impact. However, evidence thereof can be most useful in securing fairness in selection and employment decisions. There is a distinct need to examine the matter of adverse impact and its implications in the South African context. South Africa is confronted with a labour force that is growing dramatically and changing significantly. The demographic trends in our dynamically changing labour markets are likely to amplify skill and ability differences between the resulting contradictory goals of equal opportunity based on individual merit and equal employment results for subgroups of populations. Three selection strategies of a communications company were used as a basis for the assessment of adverse impact. The total population of the Call Centre selection strategy was 150. Seven instruments and measures were utilised in the study, namely, a job analysis, pre-screening exercise, psychometric ability tests, role-play simulation, structured interview, job compatibility questionnaire and a performance evaluation. The total population of the Operator Services selection strategy was 139. Five psychometric instruments were utilised in the study. The total population of the Female Leadership Development Programme selection strategy was 471. Three psychometric instruments were utilised in the study. The Adverse Impact Model was applied to each of the aforementioned strategies. In terms of the definition, adverse impact exists if the selection ratio associated with a particular passing score on a test for one sub-group of job applicants is less than 4/5th’s or 80% of the selection ration for the largest sub-group of applicants. 13 The results of the study indicate that adverse impact occurred in the following instances. In the Call Centre selection strategy, there was evidence of adverse impact in the racial analysis in the ability testing stage. There was also evidence of adverse impact in the gender analysis during this stage. There was no evidence of adverse impact in either the racial or gender analyses during the interview stage. There was no evidence of adverse impact in the racial analysis during the appointment stage. There was however evidence of adverse impact in the gender analysis during the appointment stage. The Female Leadership Development Programme selection strategy revealed evidence of adverse impact in the racial analysis during the appointment stage. The Operator Services selection strategy revealed an adverse impact in both the racial and gender analyses during the testing stage. The issue of adverse impact is obviously controversial. However, data obtained from this process will provide for informative analysis.
- Full Text:
- Date Issued: 2004
A critical analysis of the influence of the "Prevention of the illegal eviction from and unlawful occupation of Land Act 19 of 1998" on investment in residential income-producing property
- Authors: Botha, Brink
- Date: 2004
- Subjects: Rental housing -- Law and legislation -- South Africa , Eviction -- Law and legislation -- South Africa , Occupancy (Law) -- South Africa , Real estate investment -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11005 , http://hdl.handle.net/10948/321 , Rental housing -- Law and legislation -- South Africa , Eviction -- Law and legislation -- South Africa , Occupancy (Law) -- South Africa , Real estate investment -- Law and legislation -- South Africa
- Description: This research will focus on the influence of legislation (as indicated in this research) on the investment decision in residential income-producing property. Assumptions, as recorded in the hypothesis of this study, indicate that the legislation had a changing influence on the investment decision in residential income-producing property in comparison to the time period prior to the promulgation of the legislation. The research methodology will be based on a comparative analysis of the current legislation and the proposed Draft Amendment Bill. This analysis will be tested by means of a case study analysis incorporating a phenomenological study based on written data. The problems, sub-problems and hypothesis will be addressed and tested in this research in conjunction with the prescribed research methodology. This research is concluded by means of a synopsis and recommendations.
- Full Text:
- Date Issued: 2004
- Authors: Botha, Brink
- Date: 2004
- Subjects: Rental housing -- Law and legislation -- South Africa , Eviction -- Law and legislation -- South Africa , Occupancy (Law) -- South Africa , Real estate investment -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11005 , http://hdl.handle.net/10948/321 , Rental housing -- Law and legislation -- South Africa , Eviction -- Law and legislation -- South Africa , Occupancy (Law) -- South Africa , Real estate investment -- Law and legislation -- South Africa
- Description: This research will focus on the influence of legislation (as indicated in this research) on the investment decision in residential income-producing property. Assumptions, as recorded in the hypothesis of this study, indicate that the legislation had a changing influence on the investment decision in residential income-producing property in comparison to the time period prior to the promulgation of the legislation. The research methodology will be based on a comparative analysis of the current legislation and the proposed Draft Amendment Bill. This analysis will be tested by means of a case study analysis incorporating a phenomenological study based on written data. The problems, sub-problems and hypothesis will be addressed and tested in this research in conjunction with the prescribed research methodology. This research is concluded by means of a synopsis and recommendations.
- Full Text:
- Date Issued: 2004
An evaluation of the Xenopus laevis liver slice model to study the toxic effects of microcystin
- Authors: Coates, Nadya
- Date: 2003
- Subjects: Zenopus laevis , Microcystis aeruginosa -- Toxicology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11069 , http://hdl.handle.net/10948/307 , Zenopus laevis , Microcystis aeruginosa -- Toxicology
- Description: Blooms of cyanobacteria have increased in occurrence in the past three decades and have been reported to cause severe problems for animals and humans, leading to death in extreme instances. The majority of poisonings that have taken place have been attributed to a hepatotoxin produced by the species Microcystis aeruginosa, namely microcystin. The appearance of a cyanobacterial bloom does not give any indication as to its toxicity and therefore, it is imperative that simple, yet sensitive, bioassays are developed to overcome this problem. This study was undertaken to evaluate the effects of microcystin-LR on the liver of Xenopus laevis both in vitro and in vivo. This animal provides an opportunity to study the long-term hepatotoxic effects of the toxin compared to in vitro studies performed with mice and rats. The use of the liver slice model system as a potential bioassay to study the effects of microcystin-LR on Xenopus laevis liver was evaluated. Liver slices were cultured in RPMI- 1640 culture medium for periods ranging from 30 hours to 10 days and the liver slices were exposed to toxin concentrations ranging from 1nM to 500nM. The use of frog liver slices to study the longer-term effects of low-dose exposure to microcystin-LR was evaluated by observing the ultrastructural changes within hepatocytes using transmission electron microscopy, the release of the enzymes alanine aminotransferase and lactate dehydrogenase into the surrounding culture medium, as well as using a 3-[4,5-dimethylthiazol-2yl]-2,5- diphenyl tetrazolium bromide assay to determine the viability of the liver slices in culture. The amount of lipid peroxidation in the liver slices after exposure to microcystin-LR was assessed using the Thiobarbituric Acid Test. Results showed the frog liver slice culture system to be an inadequate method to evaluate the hepatotoxic effects of microcystin-LR. An in vivo assessment of the effects of microcystin-LR on Xenopus laevis was carried out using a total of 9 frogs (3 groups of 3 frogs). Frogs received a single intraperitoneal dose of 120mg/kg of microcystin-LR and were sacrificed at 8 and 24 hours post exposure. Microcystin-LR caused no significant change in serum lactate dehydrogenase levels, hepatosomatic index (liver weight as a percentage body weight), glutathione peroxidase activity, glycogen or lipid peroxidation. There was, however, an increase in glutathione sii transferase activity in the liver. The presence of the toxin in the liver was confirmed by immunohistochemistry. This study suggests that Xenopus laevis has, in some way, adapted to detoxifying aquatic toxins in the environment.
- Full Text:
- Date Issued: 2003
- Authors: Coates, Nadya
- Date: 2003
- Subjects: Zenopus laevis , Microcystis aeruginosa -- Toxicology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11069 , http://hdl.handle.net/10948/307 , Zenopus laevis , Microcystis aeruginosa -- Toxicology
- Description: Blooms of cyanobacteria have increased in occurrence in the past three decades and have been reported to cause severe problems for animals and humans, leading to death in extreme instances. The majority of poisonings that have taken place have been attributed to a hepatotoxin produced by the species Microcystis aeruginosa, namely microcystin. The appearance of a cyanobacterial bloom does not give any indication as to its toxicity and therefore, it is imperative that simple, yet sensitive, bioassays are developed to overcome this problem. This study was undertaken to evaluate the effects of microcystin-LR on the liver of Xenopus laevis both in vitro and in vivo. This animal provides an opportunity to study the long-term hepatotoxic effects of the toxin compared to in vitro studies performed with mice and rats. The use of the liver slice model system as a potential bioassay to study the effects of microcystin-LR on Xenopus laevis liver was evaluated. Liver slices were cultured in RPMI- 1640 culture medium for periods ranging from 30 hours to 10 days and the liver slices were exposed to toxin concentrations ranging from 1nM to 500nM. The use of frog liver slices to study the longer-term effects of low-dose exposure to microcystin-LR was evaluated by observing the ultrastructural changes within hepatocytes using transmission electron microscopy, the release of the enzymes alanine aminotransferase and lactate dehydrogenase into the surrounding culture medium, as well as using a 3-[4,5-dimethylthiazol-2yl]-2,5- diphenyl tetrazolium bromide assay to determine the viability of the liver slices in culture. The amount of lipid peroxidation in the liver slices after exposure to microcystin-LR was assessed using the Thiobarbituric Acid Test. Results showed the frog liver slice culture system to be an inadequate method to evaluate the hepatotoxic effects of microcystin-LR. An in vivo assessment of the effects of microcystin-LR on Xenopus laevis was carried out using a total of 9 frogs (3 groups of 3 frogs). Frogs received a single intraperitoneal dose of 120mg/kg of microcystin-LR and were sacrificed at 8 and 24 hours post exposure. Microcystin-LR caused no significant change in serum lactate dehydrogenase levels, hepatosomatic index (liver weight as a percentage body weight), glutathione peroxidase activity, glycogen or lipid peroxidation. There was, however, an increase in glutathione sii transferase activity in the liver. The presence of the toxin in the liver was confirmed by immunohistochemistry. This study suggests that Xenopus laevis has, in some way, adapted to detoxifying aquatic toxins in the environment.
- Full Text:
- Date Issued: 2003
A revision of a section of the hearing and speech scale of the Griffiths Scales of Mental Development
- Authors: Kotras, Nicole
- Date: 2004
- Subjects: Griffiths scales of mental development , Psychological tests for children
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11022 , http://hdl.handle.net/10948/350 , Griffiths scales of mental development , Psychological tests for children
- Description: Since the introduction of the Griffiths Scales of Mental Development (Griffiths Scales) in the United Kingdom (1950) and South Africa (1977) they have become widely used and researched, both at a national and international level. Studies completed in South Africa have demonstrated the invaluable role the Griffiths Scales have fulfilled in the assessment of South African children of all cultural and socio-economic groups. However, research has indicated a need for the revision of the scales specifically relating to social and cultural factors that influence performance. The aim of this study was two-fold , namely: (i) to revise the 20 small pictures and the large picture of the Hearing and Speech Scale of the Griffiths Scales, making them more culturally relevant for the children of our contemporary world, and especially in South Africa; and (ii) to describe the performance of South African children, between 60 and 83 months of age, utilizing the revised pictures. For the qualitative component of the study a questionnaire pertaining to the small and large “Experimental pictures” was completed by the participants. The participants consisted of the executive committee members of the ARICD in the United Kingdom. Additionally 17 “expert “ Griffith's users and “lay-experts” working in early childhood development throughout South Africa, were included. Their responses were content analyzed and incorporated into the Experimental pictures. This resulted in the development of the Revised Griffiths pictures. The quantitative component of the study utilized two sample pools. Sample 1 (n=204) and Sample 2 (n=180) were comprised of pre-school children aged between 60 and 83 months. Sample 1 was utilized for the 20 small revised pictures and the large revised SA picture, while sample 2 was utilized for the 20 small revised pictures and the large revised United Kingdom/ European/Australian picture. Furthermore, both samples, consisted of children from all cultural, socio-economic, language, and gender groups. x The major findings of the present study were as follows: 1. Referring to sample 1, only the White and Indian pre-schoolers correctly identified a mean number of small pictures above that which was proposed by Griffiths (1960). The Coloured pre-schoolers almost identified Griffiths (1960) proposed number. 2. Referring to sample 2, all excepting the Black pre-schoolers correctly identified Griffiths’ (1960) proposed mean of small pictures. 3. All children from sample 1 and sample 2 were able to identify more stimuli from the large revised pictures, than was proposed by Griffiths (1960). 4. All four cultural groups from samples 1 and 2, elicited a mean number of descriptive words below Griffiths’ (1960) proposed criteria. 5. White pre-schoolers from sample 1 elicited a mean number of descriptive sentences above Griffiths’ (1960) proposed criteria. 6. White and Coloured pre-schoolers from sample 2 elicited a mean number of descriptive sentences above Griffiths’ (1960) proposed criteria. 7. All four cultural groups from sample 1 and sample 2, elicited a mean number of personal or possessive pronouns below Griffith's (1960) proposed criteria. 8. A general trend noted for the four cultural groups of both samples, was that the percentage of children who passed successive age-appropriate items, did not decrease stepwise as would be expected from the placement of items in order of difficulty. In view of the latter finding, it is recommended that for South African children the placement of the items for the small and large pictures of the Hearing and Speech Scale should be revised in terms of their order of difficulty. It is furthermore recommended that separate norms for South African children be established for the Hearing and Speech Scale
- Full Text:
- Authors: Kotras, Nicole
- Date: 2004
- Subjects: Griffiths scales of mental development , Psychological tests for children
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11022 , http://hdl.handle.net/10948/350 , Griffiths scales of mental development , Psychological tests for children
- Description: Since the introduction of the Griffiths Scales of Mental Development (Griffiths Scales) in the United Kingdom (1950) and South Africa (1977) they have become widely used and researched, both at a national and international level. Studies completed in South Africa have demonstrated the invaluable role the Griffiths Scales have fulfilled in the assessment of South African children of all cultural and socio-economic groups. However, research has indicated a need for the revision of the scales specifically relating to social and cultural factors that influence performance. The aim of this study was two-fold , namely: (i) to revise the 20 small pictures and the large picture of the Hearing and Speech Scale of the Griffiths Scales, making them more culturally relevant for the children of our contemporary world, and especially in South Africa; and (ii) to describe the performance of South African children, between 60 and 83 months of age, utilizing the revised pictures. For the qualitative component of the study a questionnaire pertaining to the small and large “Experimental pictures” was completed by the participants. The participants consisted of the executive committee members of the ARICD in the United Kingdom. Additionally 17 “expert “ Griffith's users and “lay-experts” working in early childhood development throughout South Africa, were included. Their responses were content analyzed and incorporated into the Experimental pictures. This resulted in the development of the Revised Griffiths pictures. The quantitative component of the study utilized two sample pools. Sample 1 (n=204) and Sample 2 (n=180) were comprised of pre-school children aged between 60 and 83 months. Sample 1 was utilized for the 20 small revised pictures and the large revised SA picture, while sample 2 was utilized for the 20 small revised pictures and the large revised United Kingdom/ European/Australian picture. Furthermore, both samples, consisted of children from all cultural, socio-economic, language, and gender groups. x The major findings of the present study were as follows: 1. Referring to sample 1, only the White and Indian pre-schoolers correctly identified a mean number of small pictures above that which was proposed by Griffiths (1960). The Coloured pre-schoolers almost identified Griffiths (1960) proposed number. 2. Referring to sample 2, all excepting the Black pre-schoolers correctly identified Griffiths’ (1960) proposed mean of small pictures. 3. All children from sample 1 and sample 2 were able to identify more stimuli from the large revised pictures, than was proposed by Griffiths (1960). 4. All four cultural groups from samples 1 and 2, elicited a mean number of descriptive words below Griffiths’ (1960) proposed criteria. 5. White pre-schoolers from sample 1 elicited a mean number of descriptive sentences above Griffiths’ (1960) proposed criteria. 6. White and Coloured pre-schoolers from sample 2 elicited a mean number of descriptive sentences above Griffiths’ (1960) proposed criteria. 7. All four cultural groups from sample 1 and sample 2, elicited a mean number of personal or possessive pronouns below Griffith's (1960) proposed criteria. 8. A general trend noted for the four cultural groups of both samples, was that the percentage of children who passed successive age-appropriate items, did not decrease stepwise as would be expected from the placement of items in order of difficulty. In view of the latter finding, it is recommended that for South African children the placement of the items for the small and large pictures of the Hearing and Speech Scale should be revised in terms of their order of difficulty. It is furthermore recommended that separate norms for South African children be established for the Hearing and Speech Scale
- Full Text:
An assessment of bait availability, utilization and management guidelines in Eastern Cape estuaries
- Authors: Jooste, Jakobus Gerrit
- Date: 2003
- Subjects: Upogebia african -- Effects of sediments on -- South Africa -- Eastern Cape , Estuarine ecology -- South Africa -- Eastern Cape , Fishing baits -- Conservation -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11073 , http://hdl.handle.net/10948/334 , Upogebia african -- Effects of sediments on -- South Africa -- Eastern Cape , Estuarine ecology -- South Africa -- Eastern Cape , Fishing baits -- Conservation -- South Africa -- Eastern Cape
- Description: Aspects around the management of benthic soft sediment bait organisms, with special focus on the mud prawn (Upogebia africana) of eastern Cape estuaries was investigated. The recreational linefishery of the Gamtoos estuary was described, and compared to previous studies. Target fish species was identified, and a large dependency on bait sourced from estuaries needed for the capture of these species was noted, especially for spotted grunter (Pomadasys commersonnii). A comparison between bait use, success and the natural diet of target fish species was also made. The structure and distribution of sediments in the old channel mud banks was described and compared with historical data. The influence of sediments on mud prawn distribution was investigated, but no significant interactions were found at the study site. The impacts of once-off pumping and digging events, and monthly trampling on the sediments and mud prawn population was studied over a 7-month period. Initial removal rates as well as recovery time varied significantly between the two collection methods, while the largest decline in prawn numbers (to zero) with no recovery visible after seven months was caused by trampling. All disturbances caused some alteration in sediment composition, but not to such an extent that the sediments became unfavorable for mud prawns. Trampling did, however, result in the compaction of sediments to such a degree that prawns could not construct burrows. Issues around current removal quotas of bait species as well as the creation of a small-scale commercial (SSC) bait selling operation at Swartkops estuary were critically evaluated, and suggestions for the future removal rates of mud prawns based on production export calculations were made. The distribution, size, sex ratios and number of gravid females occurring along a tidal gradient as well as along horizontal gradient of the mud bank during growth (January – March) and reproductive (September – October) periods was investigated. Changes in the distribution of females between the two study periods were significant, while the distribution of reproductively active females were closely linked to the low water mark (Lower tidal levels). Females occurring in this zone were also significantly larger than females occurring towards the back of the study site. Some minor changes along the horizontal gradient were also observed. The sediment compos ition of the mud bank was found not to play a role in this distribution, leading to the suggestion that exposure to ebb and flood tide currents could influence female prawn distributions. Management recommendations based on these observations were made.
- Full Text:
- Date Issued: 2003
- Authors: Jooste, Jakobus Gerrit
- Date: 2003
- Subjects: Upogebia african -- Effects of sediments on -- South Africa -- Eastern Cape , Estuarine ecology -- South Africa -- Eastern Cape , Fishing baits -- Conservation -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11073 , http://hdl.handle.net/10948/334 , Upogebia african -- Effects of sediments on -- South Africa -- Eastern Cape , Estuarine ecology -- South Africa -- Eastern Cape , Fishing baits -- Conservation -- South Africa -- Eastern Cape
- Description: Aspects around the management of benthic soft sediment bait organisms, with special focus on the mud prawn (Upogebia africana) of eastern Cape estuaries was investigated. The recreational linefishery of the Gamtoos estuary was described, and compared to previous studies. Target fish species was identified, and a large dependency on bait sourced from estuaries needed for the capture of these species was noted, especially for spotted grunter (Pomadasys commersonnii). A comparison between bait use, success and the natural diet of target fish species was also made. The structure and distribution of sediments in the old channel mud banks was described and compared with historical data. The influence of sediments on mud prawn distribution was investigated, but no significant interactions were found at the study site. The impacts of once-off pumping and digging events, and monthly trampling on the sediments and mud prawn population was studied over a 7-month period. Initial removal rates as well as recovery time varied significantly between the two collection methods, while the largest decline in prawn numbers (to zero) with no recovery visible after seven months was caused by trampling. All disturbances caused some alteration in sediment composition, but not to such an extent that the sediments became unfavorable for mud prawns. Trampling did, however, result in the compaction of sediments to such a degree that prawns could not construct burrows. Issues around current removal quotas of bait species as well as the creation of a small-scale commercial (SSC) bait selling operation at Swartkops estuary were critically evaluated, and suggestions for the future removal rates of mud prawns based on production export calculations were made. The distribution, size, sex ratios and number of gravid females occurring along a tidal gradient as well as along horizontal gradient of the mud bank during growth (January – March) and reproductive (September – October) periods was investigated. Changes in the distribution of females between the two study periods were significant, while the distribution of reproductively active females were closely linked to the low water mark (Lower tidal levels). Females occurring in this zone were also significantly larger than females occurring towards the back of the study site. Some minor changes along the horizontal gradient were also observed. The sediment compos ition of the mud bank was found not to play a role in this distribution, leading to the suggestion that exposure to ebb and flood tide currents could influence female prawn distributions. Management recommendations based on these observations were made.
- Full Text:
- Date Issued: 2003
An exploration of adolescent risk-taking behaviour : a case study analysis
- Authors: Dietrich, Valerie
- Date: 2003
- Subjects: Teenagers -- South Africa -- Conduct of life , Risk-taking (psychology) in adolescence
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10989 , http://hdl.handle.net/10948/312 , Teenagers -- South Africa -- Conduct of life , Risk-taking (psychology) in adolescence
- Description: Do adolescents of colour really engage in risk-taking behaviours as often generalised by the public? Are they in fact the alcohol, drugs, sex, and violence generation? This study attempts to investigate the conditions influencing the choices adolescents make prior to their engaging in risk-taking behaviours. In the social sciences, concerns over adolescents’ recklessly irresponsible behaviours have deep roots. In 1904 G. Stanley Hall depicted adolescence as misbehaving because of the storms and stresses of the transition from childhood to adulthood. Subsequently, social scientists produced substantial evidence that the storminess of adolescence is largely an over generalisation, which has not been empirically substantiated. In corroboration of this interpretation, this study also indicates that not all adolescents engage in risk-taking behaviour, and those risky individuals do not necessarily engage in all spheres of risk-taking. The majority of the target group only experimented with certain risk behaviours by engaging in them on one occasion only. The specific high school was selected because the researcher knew the learners, as she was an educator there at the time. She was thus reasonably aware of the frequency, the nature and the severity of the risk-taking behaviours of the target group. In general, the most important findings of the study signified a moderate level of participation in risk-taking activities. However, in certain spheres such as cigarette smoking, alcohol usage and sexual intercourse, an extreme participation level was reported. Certain factors such as gender, age, socio-economic conditions, parental (one or both) absence, and the respondents’ attitude towards the specific behaviour, were discovered to have played an influential role in the target group taking risks. Based on the reasons advanced for engaging in risk-taking behaviour, the researcher concluded that the following theories were applicable in explaining the behaviour of the respondents. These theories are the social learning theory, symbolic interactionist theory, social identity, the theory of reasoned action, and Maslow’s hierarchy of needs. The researcher trusts that this study will assist the reader to understand the complex contributing circumstances that the target group has to contend with in making decisions.
- Full Text:
- Date Issued: 2003
- Authors: Dietrich, Valerie
- Date: 2003
- Subjects: Teenagers -- South Africa -- Conduct of life , Risk-taking (psychology) in adolescence
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10989 , http://hdl.handle.net/10948/312 , Teenagers -- South Africa -- Conduct of life , Risk-taking (psychology) in adolescence
- Description: Do adolescents of colour really engage in risk-taking behaviours as often generalised by the public? Are they in fact the alcohol, drugs, sex, and violence generation? This study attempts to investigate the conditions influencing the choices adolescents make prior to their engaging in risk-taking behaviours. In the social sciences, concerns over adolescents’ recklessly irresponsible behaviours have deep roots. In 1904 G. Stanley Hall depicted adolescence as misbehaving because of the storms and stresses of the transition from childhood to adulthood. Subsequently, social scientists produced substantial evidence that the storminess of adolescence is largely an over generalisation, which has not been empirically substantiated. In corroboration of this interpretation, this study also indicates that not all adolescents engage in risk-taking behaviour, and those risky individuals do not necessarily engage in all spheres of risk-taking. The majority of the target group only experimented with certain risk behaviours by engaging in them on one occasion only. The specific high school was selected because the researcher knew the learners, as she was an educator there at the time. She was thus reasonably aware of the frequency, the nature and the severity of the risk-taking behaviours of the target group. In general, the most important findings of the study signified a moderate level of participation in risk-taking activities. However, in certain spheres such as cigarette smoking, alcohol usage and sexual intercourse, an extreme participation level was reported. Certain factors such as gender, age, socio-economic conditions, parental (one or both) absence, and the respondents’ attitude towards the specific behaviour, were discovered to have played an influential role in the target group taking risks. Based on the reasons advanced for engaging in risk-taking behaviour, the researcher concluded that the following theories were applicable in explaining the behaviour of the respondents. These theories are the social learning theory, symbolic interactionist theory, social identity, the theory of reasoned action, and Maslow’s hierarchy of needs. The researcher trusts that this study will assist the reader to understand the complex contributing circumstances that the target group has to contend with in making decisions.
- Full Text:
- Date Issued: 2003
The challenge of applying systematic conservation planning to the marine environment using expert knowledge (focus: Sparidae)
- Authors: Bause, Mariëtte
- Date: 2004
- Subjects: Marine parks and reserves -- South Africa , Nature conservation -- South Africa , Fishery conservation -- South Africa , Sparidae
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11064 , http://hdl.handle.net/10948/343 , Marine parks and reserves -- South Africa , Nature conservation -- South Africa , Fishery conservation -- South Africa , Sparidae
- Description: Although the marine environment has generally been considered to be less in need of attention from conservationists, politicians and managers than the terrestrial environment, there has been an increasing appreciation that there is little left in the marine environment that can be considered unaltered by humans. Conservation action is therefore urgently needed to protect marine populations, species and environments from anthropogenic pressures. Since overharvesting seems to be the main cause of the collapse in coastal ecosystems, areas need to be protected so that stocks can recover. However, the proclamation of such marine protected areas (MPAs) need to be well planned to ensure that species are well represented and that their biological requirements are met in the long term. While terrestrial conservation planners have started to incorporate biological, social and economic information into so-called systematic conservation plans, marine planners have been more hesitant to use these approaches due to the greater openness of the ocean (with the associated greater dispersal of marine organisms and propogules, lower levels of endemism, and lack of ownership) and the paucity of available information. The current study aimed to investigate the applicability of systematic approaches to the process of selecting sites for a network of potential replenishment zones for seabream species that could supplement protection already afforded by existing no-fishing reserves. Since many of these seabream species are popular targets in both the recreational and commercial linefishery sectors, they have been overexploited and are in need of additional protection. Information on these species and the diversity of their associated reefs were obtained through consultations with scientists, managers and resource-users (namely SCUBA divers, spearfishers as well as recreational and commercial fishers). These data were obtained during workshops where Participatory Rural Appraisal (PRA) scoring and mapping methods were applied. Although ordinal-scale, rather than interval-or ratio-scale data were obtained, these data could be used in an interactive selection process. Because these methods require relatively cheap materials and few personnel, they could be used to collect information where limited budgets are available. Quantitative targets for the protection of individual species were set on the basis of their status in the Marine Living Resource Act, since this reflected their different requirements for protection. A preliminary investigation indicated that the current no-fishing reserves effectively achieved most of these goals for seabream species. The selection of sites for the replenishment network was based on irreplaceability analyses, while decisions between sites with lower irreplaceability values were based on explicit design rules. A total of 26 sites were required to achieve targets for all species. These replenishment zones could potentially be established, managed and monitored by voluntary community groups. This study therefore indicated that systematic conservation planning can successfully be applied to the marine environment, while the involvement of stakeholders is crucial to ensure that conservation action is supported.
- Full Text:
- Date Issued: 2004
- Authors: Bause, Mariëtte
- Date: 2004
- Subjects: Marine parks and reserves -- South Africa , Nature conservation -- South Africa , Fishery conservation -- South Africa , Sparidae
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11064 , http://hdl.handle.net/10948/343 , Marine parks and reserves -- South Africa , Nature conservation -- South Africa , Fishery conservation -- South Africa , Sparidae
- Description: Although the marine environment has generally been considered to be less in need of attention from conservationists, politicians and managers than the terrestrial environment, there has been an increasing appreciation that there is little left in the marine environment that can be considered unaltered by humans. Conservation action is therefore urgently needed to protect marine populations, species and environments from anthropogenic pressures. Since overharvesting seems to be the main cause of the collapse in coastal ecosystems, areas need to be protected so that stocks can recover. However, the proclamation of such marine protected areas (MPAs) need to be well planned to ensure that species are well represented and that their biological requirements are met in the long term. While terrestrial conservation planners have started to incorporate biological, social and economic information into so-called systematic conservation plans, marine planners have been more hesitant to use these approaches due to the greater openness of the ocean (with the associated greater dispersal of marine organisms and propogules, lower levels of endemism, and lack of ownership) and the paucity of available information. The current study aimed to investigate the applicability of systematic approaches to the process of selecting sites for a network of potential replenishment zones for seabream species that could supplement protection already afforded by existing no-fishing reserves. Since many of these seabream species are popular targets in both the recreational and commercial linefishery sectors, they have been overexploited and are in need of additional protection. Information on these species and the diversity of their associated reefs were obtained through consultations with scientists, managers and resource-users (namely SCUBA divers, spearfishers as well as recreational and commercial fishers). These data were obtained during workshops where Participatory Rural Appraisal (PRA) scoring and mapping methods were applied. Although ordinal-scale, rather than interval-or ratio-scale data were obtained, these data could be used in an interactive selection process. Because these methods require relatively cheap materials and few personnel, they could be used to collect information where limited budgets are available. Quantitative targets for the protection of individual species were set on the basis of their status in the Marine Living Resource Act, since this reflected their different requirements for protection. A preliminary investigation indicated that the current no-fishing reserves effectively achieved most of these goals for seabream species. The selection of sites for the replenishment network was based on irreplaceability analyses, while decisions between sites with lower irreplaceability values were based on explicit design rules. A total of 26 sites were required to achieve targets for all species. These replenishment zones could potentially be established, managed and monitored by voluntary community groups. This study therefore indicated that systematic conservation planning can successfully be applied to the marine environment, while the involvement of stakeholders is crucial to ensure that conservation action is supported.
- Full Text:
- Date Issued: 2004
The application of the hearsay rule in labour law proceedings
- Authors: Hanekom, Jurgens Philip
- Date: 2003
- Subjects: Labor courts -- South Africa , Evidence, Hearsay -- South Africa , Evidence (Law) -- South Africa , Labor laws and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:11053 , http://hdl.handle.net/10948/300 , Labor courts -- South Africa , Evidence, Hearsay -- South Africa , Evidence (Law) -- South Africa , Labor laws and legislation -- South Africa
- Description: To know your law and not to understand it is like a legal barbarian lost in the battlefield of legal theory. A proper and thorough understanding of the law of evidence and hearsay evidence in particular, is of paramount importance not only for lawyers but also for persons who regard themselves as labour law experts. It takes a great deal of experience before a lawyer truly becomes confident with the law of evidence and its application. The only way one becomes good at it is firstly to know the law. (Where does it come from and why is it there?) Then one must get to understand it by looking at examples and apply it in practice. Only then will a person gain practical experience. The aim of this treatise is not to try and educate experienced lawyers. This article is aimed at those that need some motivation to pursue their journey in the labour law process. Remember we all assume that lawyers know and understand their subject until they proof the contrary. In this work I shall try to highlight the importance of the law of evidence in labour law proceedings. Firstly the meaning of the law of evidence and hearsay evidence is considered. Further emphasis will be on the approach and application of the law of evidence, and in particular the hearsay rule, in labour law proceedings.
- Full Text:
- Date Issued: 2003
- Authors: Hanekom, Jurgens Philip
- Date: 2003
- Subjects: Labor courts -- South Africa , Evidence, Hearsay -- South Africa , Evidence (Law) -- South Africa , Labor laws and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:11053 , http://hdl.handle.net/10948/300 , Labor courts -- South Africa , Evidence, Hearsay -- South Africa , Evidence (Law) -- South Africa , Labor laws and legislation -- South Africa
- Description: To know your law and not to understand it is like a legal barbarian lost in the battlefield of legal theory. A proper and thorough understanding of the law of evidence and hearsay evidence in particular, is of paramount importance not only for lawyers but also for persons who regard themselves as labour law experts. It takes a great deal of experience before a lawyer truly becomes confident with the law of evidence and its application. The only way one becomes good at it is firstly to know the law. (Where does it come from and why is it there?) Then one must get to understand it by looking at examples and apply it in practice. Only then will a person gain practical experience. The aim of this treatise is not to try and educate experienced lawyers. This article is aimed at those that need some motivation to pursue their journey in the labour law process. Remember we all assume that lawyers know and understand their subject until they proof the contrary. In this work I shall try to highlight the importance of the law of evidence in labour law proceedings. Firstly the meaning of the law of evidence and hearsay evidence is considered. Further emphasis will be on the approach and application of the law of evidence, and in particular the hearsay rule, in labour law proceedings.
- Full Text:
- Date Issued: 2003
The effect of nutrient levels and ratios on the growth of Microcystis aeruginosa and microcystin production
- Authors: Sember, Craig Stewart
- Date: 2002
- Subjects: Microcystis aeruginosa -- Toxicology , Nitrates , Microcystins
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11076 , http://hdl.handle.net/10948/287 , Microcystis aeruginosa -- Toxicology , Nitrates , Microcystins
- Description: This study reports the findings on the effect of nitrates and phosphates on the biomass and toxin production of various strains of the unicellular non-nitrogen fixing cyanobacterium, Microcystis aeruginosa. The occurrence of blooms of Microcystis aeruginosa and microcystin in freshwater impoundments across the globe has been on the increase lately due to increased levels of eutrophication, resulting in human and animal deaths and illness, as well as drinking and recreational water foulment. A range of environmental factors have been shown to effect growth and microcystin production. Existing literature however is somewhat contradictory as to the effects of these physical and chemical factors on toxin production. Therefore Microcystis aeruginosa strains were cultured under batch and continuous conditions to determine the effect of nitrate and phosphate concentrations and ratios on biomass and toxin production. Cultures were analysed with regards to internal nutrient stores, biomass production, nutrient depletion, photosynthetic efficiency and microcystin production. Results showed that microcystin production correlated to growth rate, photosynthetic efficiency and internal nitrogen stores and that an optimal N:P ratio was associated with microcystin levels, growth rate and photosynthetic efficiency. Results therefore led to the conclusion that the nitrogen, carbon, and phosphate balance within the cell is closely associated with microcystin production. Whether or not microcystin is produced to maintain this balance or produced as a function of this balance remains to be determined.
- Full Text:
- Date Issued: 2002
- Authors: Sember, Craig Stewart
- Date: 2002
- Subjects: Microcystis aeruginosa -- Toxicology , Nitrates , Microcystins
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11076 , http://hdl.handle.net/10948/287 , Microcystis aeruginosa -- Toxicology , Nitrates , Microcystins
- Description: This study reports the findings on the effect of nitrates and phosphates on the biomass and toxin production of various strains of the unicellular non-nitrogen fixing cyanobacterium, Microcystis aeruginosa. The occurrence of blooms of Microcystis aeruginosa and microcystin in freshwater impoundments across the globe has been on the increase lately due to increased levels of eutrophication, resulting in human and animal deaths and illness, as well as drinking and recreational water foulment. A range of environmental factors have been shown to effect growth and microcystin production. Existing literature however is somewhat contradictory as to the effects of these physical and chemical factors on toxin production. Therefore Microcystis aeruginosa strains were cultured under batch and continuous conditions to determine the effect of nitrate and phosphate concentrations and ratios on biomass and toxin production. Cultures were analysed with regards to internal nutrient stores, biomass production, nutrient depletion, photosynthetic efficiency and microcystin production. Results showed that microcystin production correlated to growth rate, photosynthetic efficiency and internal nitrogen stores and that an optimal N:P ratio was associated with microcystin levels, growth rate and photosynthetic efficiency. Results therefore led to the conclusion that the nitrogen, carbon, and phosphate balance within the cell is closely associated with microcystin production. Whether or not microcystin is produced to maintain this balance or produced as a function of this balance remains to be determined.
- Full Text:
- Date Issued: 2002