Telkom Substantive Negotiations
- CWU
- Authors: CWU
- Date: 1998
- Subjects: CWU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/175666 , vital:42604
- Description: During the financial presentation of the company, the impression was created that the attributable income is unrealistic due to the fact that capital expenditure for the first six months were way below budget.
- Full Text:
- Date Issued: 1998
- Authors: CWU
- Date: 1998
- Subjects: CWU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/175666 , vital:42604
- Description: During the financial presentation of the company, the impression was created that the attributable income is unrealistic due to the fact that capital expenditure for the first six months were way below budget.
- Full Text:
- Date Issued: 1998
Testing Guidano's model of psychopathology in eating-disordered individuals : a multiple case study
- Authors: Hajayiannis, Helen
- Date: 1998
- Subjects: Psychology, Pathological Eating disorders -- Case studies Guidano, V F Eating disorders -- Etiology
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3192 , http://hdl.handle.net/10962/d1008557
- Description: This thesis sets out to critically examine Guidano's model of psychopathology in eating-disordered individuals . The literature review highlights the diverse etiological approaches that have been taken in understanding eating disorders. Guidano's model is presented as an alternative to traditional approaches . It is a developmental, unitary model of psychopathology, conceptualised within a systems/process-oriented approach to organised complexity. Within a qualitative framework, case study methodology is utilised to test the viability and limitations of Guidano's model. Four in-depth case histories are presented which offer appropriate material for the testing of the model. The data is analysed using the reading guide method and presented in terms of the four features of Guidano's model: (1) dysfunctional patterns of attachment; (2) sense of self; (3) major themes on systemic coherence; (4) common coping strategies. The findings of the research support Guidano's model of psychopathology in eating-disordered individuals. The findings are: (1) attachment styles are ambiguous, "intrusive, and enmeshed; participants experience a disappointment in the preferential attachment relationship; (2) that participants' sense of self is blurred and wavering; (3) the major theme on systemic coherence is the oscillation between seeking and avoiding intimacy; (4) common coping strategies are: the seeking of supportive intimacy with minimal self-exposure; withdrawal into the self; perfectionism; the development of an eating disorder; continuous thoughts about food, eating, and weight which prevents participants from becoming aware of the real issues confronting them. An evaluation of Guidano's model in terms of its specific contribution to knowledge and research on the role of father in child and adolescent psychopathology, as well as how father effects evidence in eating disorders, demonstrates the model's value as an explanatory tool and raises implications for future treatment, theory, and research practices of eating-disordered individuals.
- Full Text:
- Date Issued: 1998
- Authors: Hajayiannis, Helen
- Date: 1998
- Subjects: Psychology, Pathological Eating disorders -- Case studies Guidano, V F Eating disorders -- Etiology
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3192 , http://hdl.handle.net/10962/d1008557
- Description: This thesis sets out to critically examine Guidano's model of psychopathology in eating-disordered individuals . The literature review highlights the diverse etiological approaches that have been taken in understanding eating disorders. Guidano's model is presented as an alternative to traditional approaches . It is a developmental, unitary model of psychopathology, conceptualised within a systems/process-oriented approach to organised complexity. Within a qualitative framework, case study methodology is utilised to test the viability and limitations of Guidano's model. Four in-depth case histories are presented which offer appropriate material for the testing of the model. The data is analysed using the reading guide method and presented in terms of the four features of Guidano's model: (1) dysfunctional patterns of attachment; (2) sense of self; (3) major themes on systemic coherence; (4) common coping strategies. The findings of the research support Guidano's model of psychopathology in eating-disordered individuals. The findings are: (1) attachment styles are ambiguous, "intrusive, and enmeshed; participants experience a disappointment in the preferential attachment relationship; (2) that participants' sense of self is blurred and wavering; (3) the major theme on systemic coherence is the oscillation between seeking and avoiding intimacy; (4) common coping strategies are: the seeking of supportive intimacy with minimal self-exposure; withdrawal into the self; perfectionism; the development of an eating disorder; continuous thoughts about food, eating, and weight which prevents participants from becoming aware of the real issues confronting them. An evaluation of Guidano's model in terms of its specific contribution to knowledge and research on the role of father in child and adolescent psychopathology, as well as how father effects evidence in eating disorders, demonstrates the model's value as an explanatory tool and raises implications for future treatment, theory, and research practices of eating-disordered individuals.
- Full Text:
- Date Issued: 1998
The Anglican Church's mission to the Muslims in Cape Town during the nineteenth and twentieth centuries : a study in the changes of missiological methods and attitudes
- Authors: Pratt, Derek Alfred
- Date: 1998
- Subjects: Missions to Muslims -- South Africa -- Cape Town Mission of the church Anglican Communion -- South Africa -- Cape Town Christianity and other religions -- Islam
- Language: English
- Type: Thesis , Masters , MTh
- Identifier: vital:1236 , http://hdl.handle.net/10962/d1007592
- Description: When Bishop Robert Gray arrived at the Cape in 1848, he was concerned at the large percentage of the former slave population who had been attracted to the Muslim faith. He appointed Michael Angelo Camilleri (1848-1854) as a missionary to the Muslims of Cape Town. Camilleri's tenure was short and he was frequently used to fill other ecclesiastical posts. From 1854 until 1911 the responsibility of mission to the Muslims was given to priests whose parishes had large Muslims populations. In 1911 a fulltime missionary was once again appointed. Thomas Fothergill Lightfoot, arrived at the Cape in 1858 and served at St Paul's, Bree Street until his death in 1904. His was a ministry of love and caring. He was greatly respected for his work by all sections of the population. John Mühleissen Arnold worked in the parish of St Mary's, Woodstock. His aggressive missiological technique broke down much of the religious tolerance which had existed. His publication of a pamphlet supposedly written by a Muslim, raises doubts about his integrity as a missionary and his ethical stance as a Christian. In 1907 the Diocesan Mission Board took control of the Muslim mission and in 1911 appointed Stephen Garabedian as director. Under Garabedian the policy of the mission was aimed primarily at preventing Christian women 'lapsing' from Christianity and becoming Muslims through marriage. After his resignation in 1922, the work continued under numerous women workers who concentrated on Muslim women and children through sewing guilds and childrens' clubs. In 1960, George Swartz was appointed as director. Swartz was the first Coloured and South African-born priest to hold the post of director. Swartz served as director until he was appointed to Bonteheuwel as parish priest. He subsequently chaired the board until it ceased to meet in 1976. Throughout its one hundred twenty eight years of active existence, the Anglican mission to the Muslims failed to attract a large number of converts. Initially this could be attributed to the attraction the Muslims had to those seeking a strong community life. Later, outside influences from the Islamic world strengthened the faith of the Muslim community against any Christian conversion attempts. During the latter part of the twentieth century the mission viewed its tasks as preventing the conversion of Christians who wished to marry Muslims and informing and educating Christians on the Islamic faith. In the late 1960s, the Board encouraged dialogue rather than confrontation. It changed its name to the Board of Muslim Relationship. Apartheid was seen as the common enemy of both Christians and Muslims and they worked together against its evils. The need for a Mission Board was seen as redundant and from 1976 it ceased to be active.
- Full Text:
- Date Issued: 1998
- Authors: Pratt, Derek Alfred
- Date: 1998
- Subjects: Missions to Muslims -- South Africa -- Cape Town Mission of the church Anglican Communion -- South Africa -- Cape Town Christianity and other religions -- Islam
- Language: English
- Type: Thesis , Masters , MTh
- Identifier: vital:1236 , http://hdl.handle.net/10962/d1007592
- Description: When Bishop Robert Gray arrived at the Cape in 1848, he was concerned at the large percentage of the former slave population who had been attracted to the Muslim faith. He appointed Michael Angelo Camilleri (1848-1854) as a missionary to the Muslims of Cape Town. Camilleri's tenure was short and he was frequently used to fill other ecclesiastical posts. From 1854 until 1911 the responsibility of mission to the Muslims was given to priests whose parishes had large Muslims populations. In 1911 a fulltime missionary was once again appointed. Thomas Fothergill Lightfoot, arrived at the Cape in 1858 and served at St Paul's, Bree Street until his death in 1904. His was a ministry of love and caring. He was greatly respected for his work by all sections of the population. John Mühleissen Arnold worked in the parish of St Mary's, Woodstock. His aggressive missiological technique broke down much of the religious tolerance which had existed. His publication of a pamphlet supposedly written by a Muslim, raises doubts about his integrity as a missionary and his ethical stance as a Christian. In 1907 the Diocesan Mission Board took control of the Muslim mission and in 1911 appointed Stephen Garabedian as director. Under Garabedian the policy of the mission was aimed primarily at preventing Christian women 'lapsing' from Christianity and becoming Muslims through marriage. After his resignation in 1922, the work continued under numerous women workers who concentrated on Muslim women and children through sewing guilds and childrens' clubs. In 1960, George Swartz was appointed as director. Swartz was the first Coloured and South African-born priest to hold the post of director. Swartz served as director until he was appointed to Bonteheuwel as parish priest. He subsequently chaired the board until it ceased to meet in 1976. Throughout its one hundred twenty eight years of active existence, the Anglican mission to the Muslims failed to attract a large number of converts. Initially this could be attributed to the attraction the Muslims had to those seeking a strong community life. Later, outside influences from the Islamic world strengthened the faith of the Muslim community against any Christian conversion attempts. During the latter part of the twentieth century the mission viewed its tasks as preventing the conversion of Christians who wished to marry Muslims and informing and educating Christians on the Islamic faith. In the late 1960s, the Board encouraged dialogue rather than confrontation. It changed its name to the Board of Muslim Relationship. Apartheid was seen as the common enemy of both Christians and Muslims and they worked together against its evils. The need for a Mission Board was seen as redundant and from 1976 it ceased to be active.
- Full Text:
- Date Issued: 1998
The biology of Tilapia rendalli and Oreochromis mossambicus (Pisces: Cichlidae) in a subtropical lake in Mozambique
- Weyl, Olaf L F, Hecht, Thomas
- Authors: Weyl, Olaf L F , Hecht, Thomas
- Date: 1998
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/446944 , vital:74572 , https://www.ajol.info/index.php/az/article/view/154744
- Description: This study of age and growth, reproduction and juvenile recruitment of Tilapia rendalli and Oreochromis mossambicus was undertaken in Lake Chicamba, a large, clear subtropical lake in central Mozambique. Sectioned otoliths were used to estimate age. Marginal zone analysis showed that annulus formation occurred during winter, in July and August. Maximum age estimates for T. rendalli and O. mossambicus were 16 and 10 years, respectively. Growth was described by the 3 parameter von Bertalanffy model as Lt= 238.74 (1-e-0,636 (1+ 00905)) mm TL for T. rendalli and Lt= 266.06 (1-e-0 70904 (1+ 0269)) mm TL for O. mossambicus. The length-at-50% maturity (Lm 50) of male T. rendalli was 218 mm total lenglh (TL) and 205 mm TL in females. In O. mossambicus the Lm 50 for males was 251 mm TL and for females 223 mm TL. Both species spawned throughout summer. Lake level was found to have no effect on spawning periodicity although recruitment was flood dependent.
- Full Text:
- Date Issued: 1998
- Authors: Weyl, Olaf L F , Hecht, Thomas
- Date: 1998
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/446944 , vital:74572 , https://www.ajol.info/index.php/az/article/view/154744
- Description: This study of age and growth, reproduction and juvenile recruitment of Tilapia rendalli and Oreochromis mossambicus was undertaken in Lake Chicamba, a large, clear subtropical lake in central Mozambique. Sectioned otoliths were used to estimate age. Marginal zone analysis showed that annulus formation occurred during winter, in July and August. Maximum age estimates for T. rendalli and O. mossambicus were 16 and 10 years, respectively. Growth was described by the 3 parameter von Bertalanffy model as Lt= 238.74 (1-e-0,636 (1+ 00905)) mm TL for T. rendalli and Lt= 266.06 (1-e-0 70904 (1+ 0269)) mm TL for O. mossambicus. The length-at-50% maturity (Lm 50) of male T. rendalli was 218 mm total lenglh (TL) and 205 mm TL in females. In O. mossambicus the Lm 50 for males was 251 mm TL and for females 223 mm TL. Both species spawned throughout summer. Lake level was found to have no effect on spawning periodicity although recruitment was flood dependent.
- Full Text:
- Date Issued: 1998
The biotechnology of high rate algal ponding systems in the treatment of saline tannery wastewaters
- Authors: Dunn, Kevin Matthew
- Date: 1998
- Subjects: Sewage lagoons Tanneries -- Waste disposal Saline waters
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4006 , http://hdl.handle.net/10962/d1004066
- Description: Salinisation has been identified as a major cause of the progressive deterioration in the public water system in South Africa. To deal with this problem Waste Stabilisation Ponding systems have been used by the Leather Processing Industry as zero-dischaJ;ge wastewater evaporation disposal processes in water-limited inland regions of the country. While effective in the evaporation disposal function these systems are plagued by the generation of serious odour nuisance creating intractable environmental problems relating to adjacent residential communities. High loading to ponds of organic compounds, sulphides and ammonia results in strongly reducing anaerobic conditions prevailing in early parts of pond cascades. These are characterised by bright red colours due to the predominance of purple photosynthetic bacteria. Sporadic micro algal blooms of Spirulina sp. and Dunaliella sp. had been previously noted to occur on the latter ponds in these cascades, and were associated with their conversion to facultative function, with aerobic surface layers, and a marked reduction in odour release. This research programme undertook an investigation of the microbial ecology of a tannery waste stabilisation ponding system to describe factors which give rise to these blooms, and to determine whether microalgal growth may be manipulated to achieve a reliable oxygengenerating capping of the anaerobic ponds. The predominance of near pure cultures of Spin/lina platensis was demonstrated for the blooms and factors restricting its growth in the system were described. These include the interaction of ammonia and sulphide toxic effects and laboratory studies were undertaken to show how effluent loading may be regulated to enable effective growth of the cyanobacterium. At appropriate dilutions of tannery effluent an enhancement of growth was noted, compared to growth in defined mineral medium. An investigation of this phenomenon provided preliminary evidence for organic uptake by the pond micro algae and a possible contribution to heterotrophic nutrition. The manipulation of Spirulina sp. growth in a High Rate Algal Pond raceway was undertaken in outdoor pilot plant studies and the effect of microalgal capping of the anaerobic ponds in the cascade was demonstrated by activating a recycle loop from a blooming facultative pond. Heavy metal contaminants were effectively eliminated by an optimisation of the primary anaerobic pond function and precipitation as metal sulphides. Biomass was harvested and dried, during which a range of methods were evaluated. Toxicological studies were undertaken on the dried biomass using Artemia and chick assays, and feed studies showed its useful application in rations for the abalone Haliotlls midae and rainbow trout Onchorhynchlls mykiss. Based on positive independent assessment of research outcomes, a decision was made by the tanning company operating the Waste Stabilisation Ponding system, to proceed to the construction of a full-scale 2 500 m2 High Rate Algal Pond raceway. This would be used for controlled Spirlilina biomass production to effect a practical capping of the anaerobic ponds in the system, and to evaluate its commercial potential in the feed market. The Advanced Integrated Wastewater Ponding System described by Oswald (1991) provided the conceptual basis for the Algal Biotechnology process development undertaken. The studies of the microbial ecology and the biotechnological potential of this system have shown that a Spirulina-based High Rate Algal Ponding process can be engineered in such a way that saline tannery effluents may be treated to effect a significant reduction in overall pollution load, that biomass may be recovered as a value added product of the treatment process and that the operational performance of Waste Stabilisation Ponding systems, and hence their immediate environment, may be improved by the use of the High Rate Algal Pond as a retrofitted upgrading unit operation.
- Full Text:
- Date Issued: 1998
- Authors: Dunn, Kevin Matthew
- Date: 1998
- Subjects: Sewage lagoons Tanneries -- Waste disposal Saline waters
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4006 , http://hdl.handle.net/10962/d1004066
- Description: Salinisation has been identified as a major cause of the progressive deterioration in the public water system in South Africa. To deal with this problem Waste Stabilisation Ponding systems have been used by the Leather Processing Industry as zero-dischaJ;ge wastewater evaporation disposal processes in water-limited inland regions of the country. While effective in the evaporation disposal function these systems are plagued by the generation of serious odour nuisance creating intractable environmental problems relating to adjacent residential communities. High loading to ponds of organic compounds, sulphides and ammonia results in strongly reducing anaerobic conditions prevailing in early parts of pond cascades. These are characterised by bright red colours due to the predominance of purple photosynthetic bacteria. Sporadic micro algal blooms of Spirulina sp. and Dunaliella sp. had been previously noted to occur on the latter ponds in these cascades, and were associated with their conversion to facultative function, with aerobic surface layers, and a marked reduction in odour release. This research programme undertook an investigation of the microbial ecology of a tannery waste stabilisation ponding system to describe factors which give rise to these blooms, and to determine whether microalgal growth may be manipulated to achieve a reliable oxygengenerating capping of the anaerobic ponds. The predominance of near pure cultures of Spin/lina platensis was demonstrated for the blooms and factors restricting its growth in the system were described. These include the interaction of ammonia and sulphide toxic effects and laboratory studies were undertaken to show how effluent loading may be regulated to enable effective growth of the cyanobacterium. At appropriate dilutions of tannery effluent an enhancement of growth was noted, compared to growth in defined mineral medium. An investigation of this phenomenon provided preliminary evidence for organic uptake by the pond micro algae and a possible contribution to heterotrophic nutrition. The manipulation of Spirulina sp. growth in a High Rate Algal Pond raceway was undertaken in outdoor pilot plant studies and the effect of microalgal capping of the anaerobic ponds in the cascade was demonstrated by activating a recycle loop from a blooming facultative pond. Heavy metal contaminants were effectively eliminated by an optimisation of the primary anaerobic pond function and precipitation as metal sulphides. Biomass was harvested and dried, during which a range of methods were evaluated. Toxicological studies were undertaken on the dried biomass using Artemia and chick assays, and feed studies showed its useful application in rations for the abalone Haliotlls midae and rainbow trout Onchorhynchlls mykiss. Based on positive independent assessment of research outcomes, a decision was made by the tanning company operating the Waste Stabilisation Ponding system, to proceed to the construction of a full-scale 2 500 m2 High Rate Algal Pond raceway. This would be used for controlled Spirlilina biomass production to effect a practical capping of the anaerobic ponds in the system, and to evaluate its commercial potential in the feed market. The Advanced Integrated Wastewater Ponding System described by Oswald (1991) provided the conceptual basis for the Algal Biotechnology process development undertaken. The studies of the microbial ecology and the biotechnological potential of this system have shown that a Spirulina-based High Rate Algal Ponding process can be engineered in such a way that saline tannery effluents may be treated to effect a significant reduction in overall pollution load, that biomass may be recovered as a value added product of the treatment process and that the operational performance of Waste Stabilisation Ponding systems, and hence their immediate environment, may be improved by the use of the High Rate Algal Pond as a retrofitted upgrading unit operation.
- Full Text:
- Date Issued: 1998
The child witness in the accusatorial system
- Authors: Müller, Karen, 1964-
- Date: 1998
- Subjects: Child witnesses , Children -- Legal status, laws, etc. , Child witnesses -- South Africa , Evidence (Law)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3715 , http://hdl.handle.net/10962/d1007708 , Child witnesses , Children -- Legal status, laws, etc. , Child witnesses -- South Africa , Evidence (Law)
- Description: For the purpose of this study tbe child witness in the accusatorial system will be viewed as a source of information. When a witness gives evidence in court, the function of the witness is to provide the court with certain information. A number of crucial questions arise when the witness is a child. Do children bave the ability to remember and relate an event accurately? Are children prone to suggestion and fantasy? What effect, if any, does the court environment have on a child 's ability to convey information? What perceptions do children have about the legal process, and how do these perceptions affect their ability to testify? Do adults influence the information which children impart by the techniques they employ to obtain such information? Accepting the hypothesis that child witnesses are sources of information, the purpose of this study is to evaluate all aspects of the criminal justice system relating to child witnesses as well as available research on children to determine whether it is possible to obtain reliable and accurate information from children. Proposals will be formulated regarding the most successful methods of obtaining reliable and accurate information from children, and how these can be adapted for use by the legal system. The purpose of the study is to develop an approach to children in the legal system that will be fair to children while at the same time protecting the rights of the accused, and which will lead to a successful method of obtaining accurate information.
- Full Text:
- Date Issued: 1998
- Authors: Müller, Karen, 1964-
- Date: 1998
- Subjects: Child witnesses , Children -- Legal status, laws, etc. , Child witnesses -- South Africa , Evidence (Law)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3715 , http://hdl.handle.net/10962/d1007708 , Child witnesses , Children -- Legal status, laws, etc. , Child witnesses -- South Africa , Evidence (Law)
- Description: For the purpose of this study tbe child witness in the accusatorial system will be viewed as a source of information. When a witness gives evidence in court, the function of the witness is to provide the court with certain information. A number of crucial questions arise when the witness is a child. Do children bave the ability to remember and relate an event accurately? Are children prone to suggestion and fantasy? What effect, if any, does the court environment have on a child 's ability to convey information? What perceptions do children have about the legal process, and how do these perceptions affect their ability to testify? Do adults influence the information which children impart by the techniques they employ to obtain such information? Accepting the hypothesis that child witnesses are sources of information, the purpose of this study is to evaluate all aspects of the criminal justice system relating to child witnesses as well as available research on children to determine whether it is possible to obtain reliable and accurate information from children. Proposals will be formulated regarding the most successful methods of obtaining reliable and accurate information from children, and how these can be adapted for use by the legal system. The purpose of the study is to develop an approach to children in the legal system that will be fair to children while at the same time protecting the rights of the accused, and which will lead to a successful method of obtaining accurate information.
- Full Text:
- Date Issued: 1998
The Dance Factory, Newtown, Johannesburg a site of resistance
- Authors: Ginslov, Jeannette
- Date: 1998
- Subjects: Dance factory , Dance -- Political aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2139 , http://hdl.handle.net/10962/d1002371 , Dance factory , Dance -- Political aspects -- South Africa
- Description: This mini thesis proposes that the Dance Factory in Ne'Ntown, Johannesburg, is a site of resistance. Its source and motivation are the personal, artistic and socio-poIiticaI sites ofresistance to mainstream forms of dance with nationalistic tendencies and to dominant ideological hegemonies that enforced apartheid or nationalism. Therefore, these sites or resistance are examined prior to and after the democratisation of South African culture. An analysis of the dances choreographed in this period of transition and changing hegemonies reveal shifts of resistance. These are traced within the development of the Dance Factory. Chapter one explores the notion of resistance as a form of power and the notion of site, where the operations of power evoke resistance. Three sites of resistance within South African dance culture are identified and examined. These are the Dance Factory, the artistic site of dance and the site of the dancing body. The chapter reveals the development of these sites in a changed culture and notes a re-orientation of resistance within dance, namely Afro-fusion, and the subsequent development and emergence of 'alternative' sites of resistance. These reveal new expressionistic tendencies, body politics and the feminist strategies of 'new poetics' and 'ecriture feminine'. The codified mainstream forms of dance, subject to nationalistic strategies of dassicism and its inherent Iogocentricity are challenged and destabilised by the emergence of these altemative resistant forms of dance. Chapter two examines the artistic policies of the Nationalist Govemment, the African National Congress and the Dance Factory from 1983-1997. It notes the effects of the changes in the artistic policies on sites of resistance in dance, performed at the Dance Factory. The chapter desaibes the development of the Dance Factory, its policies of diversification as a strategy of resistance, its promotion of praxis, its resistance to nationalism and the ramifications thereof. It also explores the effects of a governmentalisation of culture and the role of the organic intellectual within the Dance Factory. An analysis of the alternative dance work 'Torso-Tongue" in chapter three furthers the argument that the Dance Factory maintains and encourages the changing sites of resistance in dance. This analysis demonstrates the resistant aspects of dance as discussed in chapter one and thereby confirms the aims and missions of the Dance Factory. The thesis examines the role of the Dance Factory as it develops, nurtures and responds to the shifts in resistance and changes in culture and dance. Most importantly the thesis exposes the resistance to and the effects of an imposition of a nationalistic ideology on dance. The resultant resistance to this form of domination is explored in dance within the site of the Dance Factory, thus supporting the premise that the Dance Factory is a site of resistance.
- Full Text:
- Date Issued: 1998
- Authors: Ginslov, Jeannette
- Date: 1998
- Subjects: Dance factory , Dance -- Political aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2139 , http://hdl.handle.net/10962/d1002371 , Dance factory , Dance -- Political aspects -- South Africa
- Description: This mini thesis proposes that the Dance Factory in Ne'Ntown, Johannesburg, is a site of resistance. Its source and motivation are the personal, artistic and socio-poIiticaI sites ofresistance to mainstream forms of dance with nationalistic tendencies and to dominant ideological hegemonies that enforced apartheid or nationalism. Therefore, these sites or resistance are examined prior to and after the democratisation of South African culture. An analysis of the dances choreographed in this period of transition and changing hegemonies reveal shifts of resistance. These are traced within the development of the Dance Factory. Chapter one explores the notion of resistance as a form of power and the notion of site, where the operations of power evoke resistance. Three sites of resistance within South African dance culture are identified and examined. These are the Dance Factory, the artistic site of dance and the site of the dancing body. The chapter reveals the development of these sites in a changed culture and notes a re-orientation of resistance within dance, namely Afro-fusion, and the subsequent development and emergence of 'alternative' sites of resistance. These reveal new expressionistic tendencies, body politics and the feminist strategies of 'new poetics' and 'ecriture feminine'. The codified mainstream forms of dance, subject to nationalistic strategies of dassicism and its inherent Iogocentricity are challenged and destabilised by the emergence of these altemative resistant forms of dance. Chapter two examines the artistic policies of the Nationalist Govemment, the African National Congress and the Dance Factory from 1983-1997. It notes the effects of the changes in the artistic policies on sites of resistance in dance, performed at the Dance Factory. The chapter desaibes the development of the Dance Factory, its policies of diversification as a strategy of resistance, its promotion of praxis, its resistance to nationalism and the ramifications thereof. It also explores the effects of a governmentalisation of culture and the role of the organic intellectual within the Dance Factory. An analysis of the alternative dance work 'Torso-Tongue" in chapter three furthers the argument that the Dance Factory maintains and encourages the changing sites of resistance in dance. This analysis demonstrates the resistant aspects of dance as discussed in chapter one and thereby confirms the aims and missions of the Dance Factory. The thesis examines the role of the Dance Factory as it develops, nurtures and responds to the shifts in resistance and changes in culture and dance. Most importantly the thesis exposes the resistance to and the effects of an imposition of a nationalistic ideology on dance. The resultant resistance to this form of domination is explored in dance within the site of the Dance Factory, thus supporting the premise that the Dance Factory is a site of resistance.
- Full Text:
- Date Issued: 1998
The development of academic literacy in the first-year psychology course at Rhodes University: an assessment of the tutorial programme
- Authors: Amos, Trevor Lawrence
- Date: 1998
- Subjects: Psychology -- Study and teaching (Higher) , Psychology -- Study and teaching (Higher) -- South Africa , Academic achievement -- South Africa , College student development programs -- South Africa
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:2923 , http://hdl.handle.net/10962/d1002432 , Psychology -- Study and teaching (Higher) , Psychology -- Study and teaching (Higher) -- South Africa , Academic achievement -- South Africa , College student development programs -- South Africa
- Description: This research is concerned with the cognitive development of students in higher education. Specifically, it is recognised that the demands facing students are different to those previously encountered in secondary education. These demands include being able to master what Strohm Kitchener (1983) calls ill-structured problems and learning the groundrules of their academic disciplines. This is termed academic literacy. Current thought in academic development proposes that students need to be shown how to mobilise their cognitive processes to meet these demands. It is argued that this is best accomplished when such activities are integrated into the discipline itself as opposed to being an add-on process. Taking into account the social and dialectical nature of learning (Vygotsky, 1978), academic development and academic literacy are seen to best occur within the tutorial system. The purpose of this research was to evaluate the 1997 first-year Psychology tutorial programme at Rhodes University, Grahamstown to assess how academic literacy was being developed. A qualitative research approach was followed, guided by the ten stage evaluation model of education programmes (Jacobs, 1996) and an adapted version of the Context, Input, Process and Product approach to evaluation (Parlett and Hamilton cited in Calder, 1995, p.25). Using indepth interviews, data was gathered from eight first year students, seven staff members and one programme co-ordinator. Focus groups were used to gather data from nine tutors. Further data collection techniques included observation of tutor briefing sessions and tutorials as well as documentary research. Data was analysed using qualitative data analysis techniques (Coffey & Atkinson, 1996). The Psychology Department at Rhodes University aims to integrate the development of academic literacy into mainstream teaching at the first year level through its tutorial programme. The Department has conceptualised its understanding of academic development as the development of academic, vocational and professional literacy which is rather unique. Academic literacy is defined and conceptualised further in a list of pre-determined skills (reading, writing and general skills) to be developed incrementally. This conceptualisation of academic literacy tends to neglect to include the mobilisation of relevant cognitive processes explicitly and the implementation tends to remain implicit. A lack of tactical strategies to implement academic development is evidence of the difficulty in moving from the philosophical level of academic development to the practical level. The programme is perceived as disorganised and lacking in a co-ordinated or incremental development of the predetermined skills.
- Full Text:
- Date Issued: 1998
- Authors: Amos, Trevor Lawrence
- Date: 1998
- Subjects: Psychology -- Study and teaching (Higher) , Psychology -- Study and teaching (Higher) -- South Africa , Academic achievement -- South Africa , College student development programs -- South Africa
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:2923 , http://hdl.handle.net/10962/d1002432 , Psychology -- Study and teaching (Higher) , Psychology -- Study and teaching (Higher) -- South Africa , Academic achievement -- South Africa , College student development programs -- South Africa
- Description: This research is concerned with the cognitive development of students in higher education. Specifically, it is recognised that the demands facing students are different to those previously encountered in secondary education. These demands include being able to master what Strohm Kitchener (1983) calls ill-structured problems and learning the groundrules of their academic disciplines. This is termed academic literacy. Current thought in academic development proposes that students need to be shown how to mobilise their cognitive processes to meet these demands. It is argued that this is best accomplished when such activities are integrated into the discipline itself as opposed to being an add-on process. Taking into account the social and dialectical nature of learning (Vygotsky, 1978), academic development and academic literacy are seen to best occur within the tutorial system. The purpose of this research was to evaluate the 1997 first-year Psychology tutorial programme at Rhodes University, Grahamstown to assess how academic literacy was being developed. A qualitative research approach was followed, guided by the ten stage evaluation model of education programmes (Jacobs, 1996) and an adapted version of the Context, Input, Process and Product approach to evaluation (Parlett and Hamilton cited in Calder, 1995, p.25). Using indepth interviews, data was gathered from eight first year students, seven staff members and one programme co-ordinator. Focus groups were used to gather data from nine tutors. Further data collection techniques included observation of tutor briefing sessions and tutorials as well as documentary research. Data was analysed using qualitative data analysis techniques (Coffey & Atkinson, 1996). The Psychology Department at Rhodes University aims to integrate the development of academic literacy into mainstream teaching at the first year level through its tutorial programme. The Department has conceptualised its understanding of academic development as the development of academic, vocational and professional literacy which is rather unique. Academic literacy is defined and conceptualised further in a list of pre-determined skills (reading, writing and general skills) to be developed incrementally. This conceptualisation of academic literacy tends to neglect to include the mobilisation of relevant cognitive processes explicitly and the implementation tends to remain implicit. A lack of tactical strategies to implement academic development is evidence of the difficulty in moving from the philosophical level of academic development to the practical level. The programme is perceived as disorganised and lacking in a co-ordinated or incremental development of the predetermined skills.
- Full Text:
- Date Issued: 1998
The diary of Robert John Mullins (1833-1913)
- Nicholls, B M, Charton, N C J, Knowling, Mary
- Authors: Nicholls, B M , Charton, N C J , Knowling, Mary
- Date: 1998
- Subjects: Mullins, Robert John, 1833-1913 , Church of the Province of Southern Africa -- Clergy , Missions -- South Africa -- Eastern Cape , Cattle Killing, 1856-1857 , St Mark's mission , St Luke's mission , Missionaries -- South Africa -- Eastern Cape , Education -- South Africa -- Cape of Good Hope , Bolotwa mission , St Peter's mission -- History , Grahamstown (South Africa) -- History , Kaffir Institute -- Grahamstown
- Language: English
- Type: Book
- Identifier: vital:527 , http://hdl.handle.net/10962/d1004350 , Mullins, Robert John, 1833-1913 , Church of the Province of Southern Africa -- Clergy , Missions -- South Africa -- Eastern Cape , Cattle Killing, 1856-1857 , St Mark's mission , St Luke's mission , Missionaries -- South Africa -- Eastern Cape , Education -- South Africa -- Cape of Good Hope , Bolotwa mission , St Peter's mission -- History , Grahamstown (South Africa) -- History , Kaffir Institute -- Grahamstown
- Description: Summary of Content: This volume offers its readers extracts from the diary and the correspondence of Robert John Mullins, Anglican missionary, priest and in due time principal of what was called the Kafir Institution in Grahamstown and as such a pioneer in the field of western education to black South Africans. After his marriage to Jennie Roe he was assisted in all that he undertook by a loyal and devoted wife. The editors have made use of the earlier diaries and manuscripts because of the light they shed on the conditions in the eastern Cape frontier in the crucial years before and after the cattle-killing. While Mullins' own observations are those of a young missionary his remarks and the record of his experiences are themselves to be viewed in the light of the recent scholarship in regard to the cattle-killing which reveals the multisidedness of an appalling social tragedy. What Mullins wrote records, for better or for worse, episodes which show how South Africans of different origins have in the past regarded one another. Mullins was a committed Christian eager to offer to all whom he could reach the salvation of Christ in which he so fervently believed.He was often intolerant of Xhosa customs he could not understand as well as often perplexed and discouraged. But the overwhelming impact of this record is what it took to be a missionary: courage, commitment, humour, resilience, a capacity to endure physical hardship and enjoy physical activity. All these were qualities which Robert John Mullins possessed in abundance. As his diary shows they were the qualities the frontier demanded. Working over a long period of time Nancy Charton and Brenda Nicholls (who became a coeditor in 1991) have transcribed the diary entries and the correspondence working with the help of the sites of some of the missionary activity. The help of members of the Mullins family (notably Judy Sturrock and her husband) is gratefully acknowledged. Earlier generous contributions made it possible to obtain a typescript from which the editors could work. Every effort has been made to identify the individuals (Xhosa, Tembu and white) and events (both in South Africa and abroad) which are alluded to in the diary. This was a time consuming task and the editors are grateful to all who helped them with it. The book consists of an introduction and eleven chapters. The introduction describes the material and the methods of the editors, discusses the religious and social conditions of the time, addresses the problems of interpartition presented by the cattle-killings, turns attention to the dilemmas of missionaries and then focusses the attention of readers on the diarist Robert John Mullins (with Jennie as later stand-in) as well as the value of the diary. There is much to interest the educationist, the theologian, the economist, and the historian. Chapter 1 deals with Mullins' voyage to the Cape in 1854 and the extracts record the experiences of an exuberant as well as a dedicated lad of sixteen. Chapter 2 deals with the arrival at the Cape in 1854. Chapter 3 gives us a picture of Mullins' experience of Graham's Town in 1854. Chapter 4 deals with Mullins' experience at St Luke's Mission. Chapter 5 covers the period of 1856-57 when Mullins was at Balotwa and the cattle-killing frenzy developed. Chapter 6 describes the hunger and turmoil which followed in the wake of the cattle-killing. Chapter 7 describes the founding of a new station, St Peter's Gwytyu. Chapter 8 is concerned with life at St Peter's in the early months of 1858. Chapter 9 covers the last months at St Peter's and his journey to the Bashee. Chapters 10 and 11 cover the early years in the married life of Robert John Mullins and his wife Jennie. The Mullins' delight in family life is strongly evident in their joy in each other's company and their anxious joy over their first-born baby. Chapter 11 gives the reader the texts of letters written by Robert John and his wife Jennie in the years which marked the end of Mullins' career as a frontier missionary, and the opening to him of the opportunity to become Principal of the Kafir Institution. A map carefully prepared by Mr Oakley West of the Geography Department, with the assistance of Deby Brody, enables the reader to trace the frontier journeys of Robert John Mullins and his wife Jennie who were among the pioneers of frontier societies who did their best to make available to others what they believed to be the eternal benefits of the Christian faith, and the accompanying mores of the 'western' culture of their day.
- Full Text:
- Date Issued: 1998
- Authors: Nicholls, B M , Charton, N C J , Knowling, Mary
- Date: 1998
- Subjects: Mullins, Robert John, 1833-1913 , Church of the Province of Southern Africa -- Clergy , Missions -- South Africa -- Eastern Cape , Cattle Killing, 1856-1857 , St Mark's mission , St Luke's mission , Missionaries -- South Africa -- Eastern Cape , Education -- South Africa -- Cape of Good Hope , Bolotwa mission , St Peter's mission -- History , Grahamstown (South Africa) -- History , Kaffir Institute -- Grahamstown
- Language: English
- Type: Book
- Identifier: vital:527 , http://hdl.handle.net/10962/d1004350 , Mullins, Robert John, 1833-1913 , Church of the Province of Southern Africa -- Clergy , Missions -- South Africa -- Eastern Cape , Cattle Killing, 1856-1857 , St Mark's mission , St Luke's mission , Missionaries -- South Africa -- Eastern Cape , Education -- South Africa -- Cape of Good Hope , Bolotwa mission , St Peter's mission -- History , Grahamstown (South Africa) -- History , Kaffir Institute -- Grahamstown
- Description: Summary of Content: This volume offers its readers extracts from the diary and the correspondence of Robert John Mullins, Anglican missionary, priest and in due time principal of what was called the Kafir Institution in Grahamstown and as such a pioneer in the field of western education to black South Africans. After his marriage to Jennie Roe he was assisted in all that he undertook by a loyal and devoted wife. The editors have made use of the earlier diaries and manuscripts because of the light they shed on the conditions in the eastern Cape frontier in the crucial years before and after the cattle-killing. While Mullins' own observations are those of a young missionary his remarks and the record of his experiences are themselves to be viewed in the light of the recent scholarship in regard to the cattle-killing which reveals the multisidedness of an appalling social tragedy. What Mullins wrote records, for better or for worse, episodes which show how South Africans of different origins have in the past regarded one another. Mullins was a committed Christian eager to offer to all whom he could reach the salvation of Christ in which he so fervently believed.He was often intolerant of Xhosa customs he could not understand as well as often perplexed and discouraged. But the overwhelming impact of this record is what it took to be a missionary: courage, commitment, humour, resilience, a capacity to endure physical hardship and enjoy physical activity. All these were qualities which Robert John Mullins possessed in abundance. As his diary shows they were the qualities the frontier demanded. Working over a long period of time Nancy Charton and Brenda Nicholls (who became a coeditor in 1991) have transcribed the diary entries and the correspondence working with the help of the sites of some of the missionary activity. The help of members of the Mullins family (notably Judy Sturrock and her husband) is gratefully acknowledged. Earlier generous contributions made it possible to obtain a typescript from which the editors could work. Every effort has been made to identify the individuals (Xhosa, Tembu and white) and events (both in South Africa and abroad) which are alluded to in the diary. This was a time consuming task and the editors are grateful to all who helped them with it. The book consists of an introduction and eleven chapters. The introduction describes the material and the methods of the editors, discusses the religious and social conditions of the time, addresses the problems of interpartition presented by the cattle-killings, turns attention to the dilemmas of missionaries and then focusses the attention of readers on the diarist Robert John Mullins (with Jennie as later stand-in) as well as the value of the diary. There is much to interest the educationist, the theologian, the economist, and the historian. Chapter 1 deals with Mullins' voyage to the Cape in 1854 and the extracts record the experiences of an exuberant as well as a dedicated lad of sixteen. Chapter 2 deals with the arrival at the Cape in 1854. Chapter 3 gives us a picture of Mullins' experience of Graham's Town in 1854. Chapter 4 deals with Mullins' experience at St Luke's Mission. Chapter 5 covers the period of 1856-57 when Mullins was at Balotwa and the cattle-killing frenzy developed. Chapter 6 describes the hunger and turmoil which followed in the wake of the cattle-killing. Chapter 7 describes the founding of a new station, St Peter's Gwytyu. Chapter 8 is concerned with life at St Peter's in the early months of 1858. Chapter 9 covers the last months at St Peter's and his journey to the Bashee. Chapters 10 and 11 cover the early years in the married life of Robert John Mullins and his wife Jennie. The Mullins' delight in family life is strongly evident in their joy in each other's company and their anxious joy over their first-born baby. Chapter 11 gives the reader the texts of letters written by Robert John and his wife Jennie in the years which marked the end of Mullins' career as a frontier missionary, and the opening to him of the opportunity to become Principal of the Kafir Institution. A map carefully prepared by Mr Oakley West of the Geography Department, with the assistance of Deby Brody, enables the reader to trace the frontier journeys of Robert John Mullins and his wife Jennie who were among the pioneers of frontier societies who did their best to make available to others what they believed to be the eternal benefits of the Christian faith, and the accompanying mores of the 'western' culture of their day.
- Full Text:
- Date Issued: 1998
The diet of the black-backed jackal (Canis mesomelas) and caracal (Felis caracal) in the Eastern Cape, South Africa
- Authors: Bussiahn, Frans Ernst Carl
- Date: 1998
- Subjects: Black-backed jackal -- South Africa -- Eastern Cape , Felis -- South Africa -- Eastern Cape , Jackals -- South Africa -- Eastern Cape , Jackals -- Food , Felis -- Food
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5807 , http://hdl.handle.net/10962/d1006489 , Black-backed jackal -- South Africa -- Eastern Cape , Felis -- South Africa -- Eastern Cape , Jackals -- South Africa -- Eastern Cape , Jackals -- Food , Felis -- Food
- Description: The black-backed jackal (Canis mesomelas) and the caracal (Felis caracal) are considered by most farmers in the Eastern Cape to be responsible for excessive livestock losses (sheep and goats) and are, as such, hunted extensively within the Province. Stomach content analyses of individuals killed during predator control operations indicate that caracal are opportunistic hunters of small to medium-sized mammals, preying predominantly on antelope within farmland. Black-backed jackal are opportunistic omnivores, preying predominantly on livestock and antelope in farmland, while invertebrates and antelope constitute the major food items within a game reserve. The diet of caracal was found to be largely influenced by the age of individual animals with old and young animals being the predominant killers of livestock, whereas black-backed jackal diet is influenced primarily by the social structure exhibited by the species, with male animals exhibiting a marked summer peak in livestock killing, due to the increased energetic demands of parental care associated with a long term pair bond. Two caracal (a sub-adult male and adult female), were radio-tracked within farmland for a total of twelve months, yielding the smallest recorded homerange sizes for the species to date (2.1km² and 1.3km² respectively). No livestock losses were recorded within these homeranges for the duration of the study. These data suggest a relatively high abundance of caracal within Lower Albany and further illustrate that individual animals are capable of preying solely on natural prey species over an extended period, when occurring within livestock farming areas. The analysis of local hunt club records and questionnaires revealed a higher incidence of local black-backed jackal (15.2 PD/Kill), than caracal (34.7 PD/Kill), with a marked seasonal peak in kills, for both species, occurring during summer months. The use of hound packs was found to be more effective in reducing the overall abundance of caracal than black-backed jackal, as this technique was seen to eliminate more adult female caracal than black-backed jackal, during the respective breeding season of each species. Local hunt club owners and farmers were more accurate in identifying problem black-backed jackal (74%), than caracal (59%). Recommendations are presented for minimizing stock losses through the application of selective control of specific problem animals, the use of various control measures and encouraging natural prey abundance.
- Full Text:
- Date Issued: 1998
- Authors: Bussiahn, Frans Ernst Carl
- Date: 1998
- Subjects: Black-backed jackal -- South Africa -- Eastern Cape , Felis -- South Africa -- Eastern Cape , Jackals -- South Africa -- Eastern Cape , Jackals -- Food , Felis -- Food
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5807 , http://hdl.handle.net/10962/d1006489 , Black-backed jackal -- South Africa -- Eastern Cape , Felis -- South Africa -- Eastern Cape , Jackals -- South Africa -- Eastern Cape , Jackals -- Food , Felis -- Food
- Description: The black-backed jackal (Canis mesomelas) and the caracal (Felis caracal) are considered by most farmers in the Eastern Cape to be responsible for excessive livestock losses (sheep and goats) and are, as such, hunted extensively within the Province. Stomach content analyses of individuals killed during predator control operations indicate that caracal are opportunistic hunters of small to medium-sized mammals, preying predominantly on antelope within farmland. Black-backed jackal are opportunistic omnivores, preying predominantly on livestock and antelope in farmland, while invertebrates and antelope constitute the major food items within a game reserve. The diet of caracal was found to be largely influenced by the age of individual animals with old and young animals being the predominant killers of livestock, whereas black-backed jackal diet is influenced primarily by the social structure exhibited by the species, with male animals exhibiting a marked summer peak in livestock killing, due to the increased energetic demands of parental care associated with a long term pair bond. Two caracal (a sub-adult male and adult female), were radio-tracked within farmland for a total of twelve months, yielding the smallest recorded homerange sizes for the species to date (2.1km² and 1.3km² respectively). No livestock losses were recorded within these homeranges for the duration of the study. These data suggest a relatively high abundance of caracal within Lower Albany and further illustrate that individual animals are capable of preying solely on natural prey species over an extended period, when occurring within livestock farming areas. The analysis of local hunt club records and questionnaires revealed a higher incidence of local black-backed jackal (15.2 PD/Kill), than caracal (34.7 PD/Kill), with a marked seasonal peak in kills, for both species, occurring during summer months. The use of hound packs was found to be more effective in reducing the overall abundance of caracal than black-backed jackal, as this technique was seen to eliminate more adult female caracal than black-backed jackal, during the respective breeding season of each species. Local hunt club owners and farmers were more accurate in identifying problem black-backed jackal (74%), than caracal (59%). Recommendations are presented for minimizing stock losses through the application of selective control of specific problem animals, the use of various control measures and encouraging natural prey abundance.
- Full Text:
- Date Issued: 1998
The effect of different parameters on the rupture properties of leather in a tensile test
- Authors: Makhothe, Kelebohile
- Date: 1998
- Subjects: Leather -- Testing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5462 , http://hdl.handle.net/10962/d1005247 , Leather -- Testing
- Description: This thesis explores the effect of some parameters on the breaking strain, strength and the shape of the stress-strain curve of bovine leather as revealed by uniaxial tensile tests. The parameters explored are fatliquoring, moisture content, strain rate and cyclic stressing. A basic mechanical model of a simple two-dimensional weave is created and used to describe the effect of such a weave on the shape of the stress-strain curve. It is found that fatliquoring lubricates and opens up the fibre structure and thereby makes the weave more extensible. The increase in the extensibility depends on the direction in which samples are cut and therefore the manner in which the fibres are orientated. Patliquoring is observed to increase the degree to which fibres pull out at break. There are indications that the strength of fatliquored leather decreases with time of storage, while the extensibility increases. The effect of the strain rate on the breaking strain, the tensile strength and the shape of the stress-strain curve is not very clear. The stressing and releasing leather decreases the strength of leather when the fibres are orientated preferentially along the direction of the applied stresses, but has an insignificant effect in the transverse direction. It is concluded that the degree of lubrication in a weave and the orientation of the fibre bundles significantly influence the performance of leather in a test. Both moisture and fatliquoring lubricate the weave. In both the cases the degree of fibre adhesions in a weave is decreased. A well lubricated weave allows its constituent fibres to slide and align along the direction of the applied stresses, and this tends to occur before the fibres themselves areextended. Cyclic testing, at low strains, ruptures fibre adhesions and as a result induces permanent set and makes a hide softer. Most of the work done in breaking the fibre adhesion is done in the first cycle.
- Full Text:
- Date Issued: 1998
- Authors: Makhothe, Kelebohile
- Date: 1998
- Subjects: Leather -- Testing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5462 , http://hdl.handle.net/10962/d1005247 , Leather -- Testing
- Description: This thesis explores the effect of some parameters on the breaking strain, strength and the shape of the stress-strain curve of bovine leather as revealed by uniaxial tensile tests. The parameters explored are fatliquoring, moisture content, strain rate and cyclic stressing. A basic mechanical model of a simple two-dimensional weave is created and used to describe the effect of such a weave on the shape of the stress-strain curve. It is found that fatliquoring lubricates and opens up the fibre structure and thereby makes the weave more extensible. The increase in the extensibility depends on the direction in which samples are cut and therefore the manner in which the fibres are orientated. Patliquoring is observed to increase the degree to which fibres pull out at break. There are indications that the strength of fatliquored leather decreases with time of storage, while the extensibility increases. The effect of the strain rate on the breaking strain, the tensile strength and the shape of the stress-strain curve is not very clear. The stressing and releasing leather decreases the strength of leather when the fibres are orientated preferentially along the direction of the applied stresses, but has an insignificant effect in the transverse direction. It is concluded that the degree of lubrication in a weave and the orientation of the fibre bundles significantly influence the performance of leather in a test. Both moisture and fatliquoring lubricate the weave. In both the cases the degree of fibre adhesions in a weave is decreased. A well lubricated weave allows its constituent fibres to slide and align along the direction of the applied stresses, and this tends to occur before the fibres themselves areextended. Cyclic testing, at low strains, ruptures fibre adhesions and as a result induces permanent set and makes a hide softer. Most of the work done in breaking the fibre adhesion is done in the first cycle.
- Full Text:
- Date Issued: 1998
The effect of environmental factors and hormone treatments on ovulation rate and spawning success in cardinal tetras, Paracheirodon axelrodi (Pisces: Characidae)
- Authors: Burton, Simon Mark
- Date: 1998
- Subjects: Characidae , Characidae -- Breeding , Tropical fish -- Breeding , Fishes -- Induced spawning , Characidae -- Spawning
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5273 , http://hdl.handle.net/10962/d1005117 , Characidae , Characidae -- Breeding , Tropical fish -- Breeding , Fishes -- Induced spawning , Characidae -- Spawning
- Description: Cardinal tetras, Paracheirodon axelrodi (Pisces: Characidae), are among the most popular tropical ornamental fish in the world. Millions of cardinal tetras are removed from their natural habitat, the upper tributaries of the Rio Negro in Brazil, each year and exported to North America and Europe where they are abundantly available at low cost. This, combined with the fact that they do not spawn freely in captivity has excluded any incentive to culture this fish on a commercial scale in these areas. However, the demand for cardinal tetras in South Africa is high, but their availability is limited to sporadic imports of wild caught fish which has resulted in an increase in their relative value. Thus, there is an appreciable incentive to investigate methods for inducing this species to reproduce in captivity. Information on methods for inducing spawning would form an integral part of a potential production plan for the culture of this species in South Africa. This study consisted of a number of experiments designed to investigate factors related to the spawning of cardinal tetras in captivity. The first series of experiments investigated the effect of variables such as the water chemistry of the experimental system, the sex ratio of the fish, the effect of conditioning and the effect of different spawning media on spawning success. The second series of experiments tested the effects of various environmental stimuli or hormonal treatments on spawning in cardinal tetras. Environmental stimuli tested included a rise in temperature, a rise in water level and a fresh rain water flush. Hormonal treatments included feeding GnRHa enriched brine shrimps to the fish or the application of hormone injections (hypophysation). Neither environmental stimuli nor brine shrimp enrichment induced cardinals to spawn in a repeatable manner. The same was true for hypophysation, but in this case a low incedence of ovulation of injected females was observed. Oocytes from ovulated and non-ovulated females were examined under a microscope and from this it was determined that cardinal tetras are group synchronous spawners, containing two distinct cohorts of oocytes in the ovary. The effect of a number of environmental stimuli on ovulation rate in cardinal tetras were then tested but did not induce ovulation in any females. A series of three experiments was performed investigating the effect of conditioning the sexes together on ovulation rate and spawning success. Conditioning the sexes together had no effect on spawning success, but a significantly higher ovulation rate was observed in females that vvere conditioned together with males. Male cardinals did not follow this trend and lost condition when conditioned together with females. The next experiment tested if pheromones from red serpae tetras, Hyphessobrycon serpae, could be used to induce ovulation and spawning in cardinal tetras. This was found not to be the case. The final series of experiments tested the effect of Aquaspawn® enriched Artemia on ovulation rates in female cardinal tetras. Aquaspawn® is a water soluble preparation of GnRHa and dopamine. Aquaspawn® enriched Artemia were found to be effective for inducing female cardinal tetras to ovulate. However, the results from this method of enrichment were not entirely reliable and further research is warranted. Finally, a protocol for evaluating spawning in topical, freshwater egg-laying fish was proposed, based on the results from this study. The advantages and disadvantages of such a protocol were discussed.
- Full Text:
- Date Issued: 1998
- Authors: Burton, Simon Mark
- Date: 1998
- Subjects: Characidae , Characidae -- Breeding , Tropical fish -- Breeding , Fishes -- Induced spawning , Characidae -- Spawning
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5273 , http://hdl.handle.net/10962/d1005117 , Characidae , Characidae -- Breeding , Tropical fish -- Breeding , Fishes -- Induced spawning , Characidae -- Spawning
- Description: Cardinal tetras, Paracheirodon axelrodi (Pisces: Characidae), are among the most popular tropical ornamental fish in the world. Millions of cardinal tetras are removed from their natural habitat, the upper tributaries of the Rio Negro in Brazil, each year and exported to North America and Europe where they are abundantly available at low cost. This, combined with the fact that they do not spawn freely in captivity has excluded any incentive to culture this fish on a commercial scale in these areas. However, the demand for cardinal tetras in South Africa is high, but their availability is limited to sporadic imports of wild caught fish which has resulted in an increase in their relative value. Thus, there is an appreciable incentive to investigate methods for inducing this species to reproduce in captivity. Information on methods for inducing spawning would form an integral part of a potential production plan for the culture of this species in South Africa. This study consisted of a number of experiments designed to investigate factors related to the spawning of cardinal tetras in captivity. The first series of experiments investigated the effect of variables such as the water chemistry of the experimental system, the sex ratio of the fish, the effect of conditioning and the effect of different spawning media on spawning success. The second series of experiments tested the effects of various environmental stimuli or hormonal treatments on spawning in cardinal tetras. Environmental stimuli tested included a rise in temperature, a rise in water level and a fresh rain water flush. Hormonal treatments included feeding GnRHa enriched brine shrimps to the fish or the application of hormone injections (hypophysation). Neither environmental stimuli nor brine shrimp enrichment induced cardinals to spawn in a repeatable manner. The same was true for hypophysation, but in this case a low incedence of ovulation of injected females was observed. Oocytes from ovulated and non-ovulated females were examined under a microscope and from this it was determined that cardinal tetras are group synchronous spawners, containing two distinct cohorts of oocytes in the ovary. The effect of a number of environmental stimuli on ovulation rate in cardinal tetras were then tested but did not induce ovulation in any females. A series of three experiments was performed investigating the effect of conditioning the sexes together on ovulation rate and spawning success. Conditioning the sexes together had no effect on spawning success, but a significantly higher ovulation rate was observed in females that vvere conditioned together with males. Male cardinals did not follow this trend and lost condition when conditioned together with females. The next experiment tested if pheromones from red serpae tetras, Hyphessobrycon serpae, could be used to induce ovulation and spawning in cardinal tetras. This was found not to be the case. The final series of experiments tested the effect of Aquaspawn® enriched Artemia on ovulation rates in female cardinal tetras. Aquaspawn® is a water soluble preparation of GnRHa and dopamine. Aquaspawn® enriched Artemia were found to be effective for inducing female cardinal tetras to ovulate. However, the results from this method of enrichment were not entirely reliable and further research is warranted. Finally, a protocol for evaluating spawning in topical, freshwater egg-laying fish was proposed, based on the results from this study. The advantages and disadvantages of such a protocol were discussed.
- Full Text:
- Date Issued: 1998
The effects of night work and task diversification on efficiency of performance
- Authors: Munton, Lynne Kerry
- Date: 1998
- Subjects: Night work -- Evaluation , Shift systems , Performance
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:5175 , http://hdl.handle.net/10962/d1018253
- Description: This study investigated the effects of night work on performance efficiency. Night work is generally acknowledged to impair performance, yet much research has contradicted this assertion. The feasibility of including brief periods of physical activity to stimulate arousal within mentally demanding work shifts was also evaluated. Thirty six postgraduate volunteers were assigned to either the cognitive tasks (CT) or cognitive and motor tasks (CMT) group. All subjects performed three psycho-motor tests, using the Vienna Test System, at midday and midnight. The CMT group performed a short cycling activity before each test. Heart rate responses served as physiological measures, the Perceived Strain Scale was used to quantify individual perceptions of strain and performance efficiency was assessed in terms of speed and accuracy. Although several trends were apparent, no significant differences (p < 0.05) were revealed with respect to the three performance variables between the midday and midnight test sessions, or between the CT and CMT subjects, other than the higher heart rates recorded in the CMT group. In summary, neither time of day nor physical activity were found to affect performance within the controlled environment of this study.
- Full Text:
- Date Issued: 1998
- Authors: Munton, Lynne Kerry
- Date: 1998
- Subjects: Night work -- Evaluation , Shift systems , Performance
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:5175 , http://hdl.handle.net/10962/d1018253
- Description: This study investigated the effects of night work on performance efficiency. Night work is generally acknowledged to impair performance, yet much research has contradicted this assertion. The feasibility of including brief periods of physical activity to stimulate arousal within mentally demanding work shifts was also evaluated. Thirty six postgraduate volunteers were assigned to either the cognitive tasks (CT) or cognitive and motor tasks (CMT) group. All subjects performed three psycho-motor tests, using the Vienna Test System, at midday and midnight. The CMT group performed a short cycling activity before each test. Heart rate responses served as physiological measures, the Perceived Strain Scale was used to quantify individual perceptions of strain and performance efficiency was assessed in terms of speed and accuracy. Although several trends were apparent, no significant differences (p < 0.05) were revealed with respect to the three performance variables between the midday and midnight test sessions, or between the CT and CMT subjects, other than the higher heart rates recorded in the CMT group. In summary, neither time of day nor physical activity were found to affect performance within the controlled environment of this study.
- Full Text:
- Date Issued: 1998
The effects of whole body immersion in cold water upon subsequent terrestrial aerobic performance : a study in hypothermia
- Authors: Manley, Elizabeth
- Date: 1998 , 2013-09-04
- Subjects: Hypothermia , Cold -- Physiological effect , Temperature -- Physiological effect , Aerobic exercises , Cryobiology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5143 , http://hdl.handle.net/10962/d1007458 , Hypothermia , Cold -- Physiological effect , Temperature -- Physiological effect , Aerobic exercises , Cryobiology
- Description: This study examined the extent to which physiological and psychological concomitants of aerobic terrestrial performance were affected by body cooling of varying degrees induced by cold water immersion (CWI). Thirteen male and 13 female subjects underwent three randomly assigned 30 min treadmill runs: a control run without prior manipulation of the subjects' thermal status and the same exercise after "central" (core temperature 1°C below pre-immersion) and "peripheral" cooling (skin heat loss 100kcal.m⁻².h⁻¹). During treadmill runs core temperature was measured, together with chest, leg, arm and hand temperatures, from which mean skin temperature (T [subscript]s[subscript]k) and mean body temperature (T[subscript]b) were calculated. Heart rate, oxygen consumption (VO₂,), carbon dioxide production (VCO₂), minute ventilation (V₂ (BTPS)), breathing frequency (f), cadence and ratings of perceived exertion (RPE) and thermal sensation (PTS) were also measured. Both central and peripheral cooling resulted in significantly reduced T[subscript]r[subscript]e (males : control 37.9±0. 3°C; central cooling : 36.8±0.5°C; peripheral cooling: 37.5±0.4°C; females: control: 37.9±0.4°C; central cooling: 37.2±0.5; p<0.05) during subsequent treadmill running, except following peripheral cooling for females (37.9±0.3°C) . For males and females T[subscript]s[subscript]k was lower following peripheral cooling than control values and lowest after central cooling (males: control: 30.0±1.3°C; central cooling: 36.8±0.5°C; peripheral cooling: 37.5±0.4°C; females: control: 30.5±1.2°C; central cooling: 25.9±1.8°C; peripheral cooling: 26.9±1.9°C; p<0.05). Female subjects experienced significantly higher T[subscript]r[subscript]e than males following central and peripheral cooling and a lower T[subscript]s[subscript]k following central cooling. Females experienced less of an increase in heart rate than males during exercise following central and peripheral cooling (control: l57.7±23.7b.min⁻¹; central cooling: 143.5±20.5b.min⁻¹; peripheral cooling 151.7±16.7b.min⁻¹; p<0 .05). Male responses were the same following central cooling but higher for peripheral cooling than control values (control: 139.1±7.3b.min⁻¹; central cooling 134.7±17.5b.min⁻¹; peripheral cooling: 145.0±16.4b.min⁻¹; p<0.05). These data indicate a depression in cardiovascular function for females following peripheral cooling that was not apparent for males. The VO₂ was not different between tests for males; only peripheral cooling resulted in a raised VO₂ of 28.6±3 .3ml.kg⁻¹.min⁻¹ (p<0 .05) for females compared to 27.6±2.6ml.kg⁻¹.min⁻¹ (control). A biphasic response was evident for VO₂ VCO₂ and V[subscript]B (BTPS). For both sexes overall RPE was lower for peripheral cooling (males: 9.4±1.9; females: 8.7±1.3; p<0 .05) than for control and central cooling. Central RPE was only changed for females following peripheral cooling. Changes in cadence and step length together with the effect of low skin and leg temperatures resulted in higher local RPE for females after central cooling (9.6±1.2; p<0.05) than control (9.4±1.9) and peripheral cooling (8.9±1.2 ). Males and females rated the same ambient temperature during the same exercise lower after peripheral cooling (males: 4.6±1.5; females : 5.3±1.3) than control values and lower still after central cooling (males: 3. 8±1.8; females: 2 .7±l. 5) In this study T[subscript]s[subscript]k was the primary determinant of PTS after precooling. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 1998
- Authors: Manley, Elizabeth
- Date: 1998 , 2013-09-04
- Subjects: Hypothermia , Cold -- Physiological effect , Temperature -- Physiological effect , Aerobic exercises , Cryobiology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5143 , http://hdl.handle.net/10962/d1007458 , Hypothermia , Cold -- Physiological effect , Temperature -- Physiological effect , Aerobic exercises , Cryobiology
- Description: This study examined the extent to which physiological and psychological concomitants of aerobic terrestrial performance were affected by body cooling of varying degrees induced by cold water immersion (CWI). Thirteen male and 13 female subjects underwent three randomly assigned 30 min treadmill runs: a control run without prior manipulation of the subjects' thermal status and the same exercise after "central" (core temperature 1°C below pre-immersion) and "peripheral" cooling (skin heat loss 100kcal.m⁻².h⁻¹). During treadmill runs core temperature was measured, together with chest, leg, arm and hand temperatures, from which mean skin temperature (T [subscript]s[subscript]k) and mean body temperature (T[subscript]b) were calculated. Heart rate, oxygen consumption (VO₂,), carbon dioxide production (VCO₂), minute ventilation (V₂ (BTPS)), breathing frequency (f), cadence and ratings of perceived exertion (RPE) and thermal sensation (PTS) were also measured. Both central and peripheral cooling resulted in significantly reduced T[subscript]r[subscript]e (males : control 37.9±0. 3°C; central cooling : 36.8±0.5°C; peripheral cooling: 37.5±0.4°C; females: control: 37.9±0.4°C; central cooling: 37.2±0.5; p<0.05) during subsequent treadmill running, except following peripheral cooling for females (37.9±0.3°C) . For males and females T[subscript]s[subscript]k was lower following peripheral cooling than control values and lowest after central cooling (males: control: 30.0±1.3°C; central cooling: 36.8±0.5°C; peripheral cooling: 37.5±0.4°C; females: control: 30.5±1.2°C; central cooling: 25.9±1.8°C; peripheral cooling: 26.9±1.9°C; p<0.05). Female subjects experienced significantly higher T[subscript]r[subscript]e than males following central and peripheral cooling and a lower T[subscript]s[subscript]k following central cooling. Females experienced less of an increase in heart rate than males during exercise following central and peripheral cooling (control: l57.7±23.7b.min⁻¹; central cooling: 143.5±20.5b.min⁻¹; peripheral cooling 151.7±16.7b.min⁻¹; p<0 .05). Male responses were the same following central cooling but higher for peripheral cooling than control values (control: 139.1±7.3b.min⁻¹; central cooling 134.7±17.5b.min⁻¹; peripheral cooling: 145.0±16.4b.min⁻¹; p<0.05). These data indicate a depression in cardiovascular function for females following peripheral cooling that was not apparent for males. The VO₂ was not different between tests for males; only peripheral cooling resulted in a raised VO₂ of 28.6±3 .3ml.kg⁻¹.min⁻¹ (p<0 .05) for females compared to 27.6±2.6ml.kg⁻¹.min⁻¹ (control). A biphasic response was evident for VO₂ VCO₂ and V[subscript]B (BTPS). For both sexes overall RPE was lower for peripheral cooling (males: 9.4±1.9; females: 8.7±1.3; p<0 .05) than for control and central cooling. Central RPE was only changed for females following peripheral cooling. Changes in cadence and step length together with the effect of low skin and leg temperatures resulted in higher local RPE for females after central cooling (9.6±1.2; p<0.05) than control (9.4±1.9) and peripheral cooling (8.9±1.2 ). Males and females rated the same ambient temperature during the same exercise lower after peripheral cooling (males: 4.6±1.5; females : 5.3±1.3) than control values and lower still after central cooling (males: 3. 8±1.8; females: 2 .7±l. 5) In this study T[subscript]s[subscript]k was the primary determinant of PTS after precooling. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 1998
The end of apartheid and the organisation of work in manufacturing plants in South Africa's Eastern Cape Province
- Authors: Smith, M R , Wood, G T
- Date: 1998
- Language: English
- Type: text , Article
- Identifier: vital:6319 , http://hdl.handle.net/10962/d1011313
- Description: The election of 1994 radically changed the environment within which management chose its labour control policies. Prior to the change of government in 1994 plant practices were shaped by the fact of substantial protection against foreign competition, widespread illiteracy, and a set of laws and policies that offered few protections for individual workers or organised labour. Since the change in government the political and legal environment has substantially changed. In this paper we report on management practices before and after the political changes in South Africa in a set of plants in a part of the country where many of the current difficulties of the South African economy exist in a fairly extreme form.
- Full Text:
- Date Issued: 1998
- Authors: Smith, M R , Wood, G T
- Date: 1998
- Language: English
- Type: text , Article
- Identifier: vital:6319 , http://hdl.handle.net/10962/d1011313
- Description: The election of 1994 radically changed the environment within which management chose its labour control policies. Prior to the change of government in 1994 plant practices were shaped by the fact of substantial protection against foreign competition, widespread illiteracy, and a set of laws and policies that offered few protections for individual workers or organised labour. Since the change in government the political and legal environment has substantially changed. In this paper we report on management practices before and after the political changes in South Africa in a set of plants in a part of the country where many of the current difficulties of the South African economy exist in a fairly extreme form.
- Full Text:
- Date Issued: 1998
The growth, development and impact of the Grahamstown Festival of the Arts with special reference to music
- Authors: Silva, Jane Susan
- Date: 1998
- Subjects: Standard Bank National Arts Festival -- Grahamstown , Standard Bank National Arts Festival -- Influence , Grahamstown (South Africa) -- Art and music , Music -- South Africa -- Eastern Cape -- Grahamstown
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2656 , http://hdl.handle.net/10962/d1002322 , Standard Bank National Arts Festival -- Grahamstown , Standard Bank National Arts Festival -- Influence , Grahamstown (South Africa) -- Art and music , Music -- South Africa -- Eastern Cape -- Grahamstown
- Description: The Grahamstown Festival has become a huge and complex annual celebration of the arts, transforming the small Eastern Cape city for ten days every year. However this event had very modest beginnings, as did music and festivals in the city of Grahamstown. From its early days Grahamstown showed strong signs of becoming an important cultural centre, presenting numerous musical concerts from 1812, the festival tradition in the city beginning in 1887. The modern arts festival, initiated in 1971, had a chequered history during the early and mid 1970's, weathering economic recession, petrol restrictions and a repressive and restrictive political atmosphere. However by 1979 the event had become established and popular enough to ensure continued success during the 1980's. The period 1980-89 was one of great growth and development for the festival regarding attendance, and the number and nature of productions presented. Music had always been an integral part of the festival, and for the first time its role in this artistic celebration is being examined. The impact of such an event is varied and far-reaching, and thus difficult to assess, but the thesis ends with an attempt to gauge the Festival's impact.
- Full Text:
- Date Issued: 1998
- Authors: Silva, Jane Susan
- Date: 1998
- Subjects: Standard Bank National Arts Festival -- Grahamstown , Standard Bank National Arts Festival -- Influence , Grahamstown (South Africa) -- Art and music , Music -- South Africa -- Eastern Cape -- Grahamstown
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2656 , http://hdl.handle.net/10962/d1002322 , Standard Bank National Arts Festival -- Grahamstown , Standard Bank National Arts Festival -- Influence , Grahamstown (South Africa) -- Art and music , Music -- South Africa -- Eastern Cape -- Grahamstown
- Description: The Grahamstown Festival has become a huge and complex annual celebration of the arts, transforming the small Eastern Cape city for ten days every year. However this event had very modest beginnings, as did music and festivals in the city of Grahamstown. From its early days Grahamstown showed strong signs of becoming an important cultural centre, presenting numerous musical concerts from 1812, the festival tradition in the city beginning in 1887. The modern arts festival, initiated in 1971, had a chequered history during the early and mid 1970's, weathering economic recession, petrol restrictions and a repressive and restrictive political atmosphere. However by 1979 the event had become established and popular enough to ensure continued success during the 1980's. The period 1980-89 was one of great growth and development for the festival regarding attendance, and the number and nature of productions presented. Music had always been an integral part of the festival, and for the first time its role in this artistic celebration is being examined. The impact of such an event is varied and far-reaching, and thus difficult to assess, but the thesis ends with an attempt to gauge the Festival's impact.
- Full Text:
- Date Issued: 1998
The interaction of melatonin and its precursors with aluminium, cadmium, copper, iron, lead, and zinc
- Limson, Janice L, Nyokong, Tebello, Daya, Santy
- Authors: Limson, Janice L , Nyokong, Tebello , Daya, Santy
- Date: 1998
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/293323 , vital:57075 , xlink:href="https://doi.org/10.1111/j.1600-079X.1998.tb00361.x"
- Description: Melatonin, a pineal secretory product, and its precursors, tryptophan and serotonin, were examined for their metal binding affinities for both essential and toxic metals: aluminium, cadmium, copper, iron, lead, and zinc. An electrochemical technique, adsorptive stripping voltammetry, showed the varying abilities of melatonin and its precursors to bind the metals in situ. The results show that the following metal complexes were formed: aluminium with melatonin, tryptophan, and serotonin; cadmium with melatonin and tryptophan; copper with melatonin and serotonin; iron(III) with melatonin and serotonin; lead with melatonin, tryptophan, and serotonin; and zinc with melatonin and tryptophan. Iron(II) showed the formation of an in situ complex with tryptophan only. These studies suggest a further role for melatonin in the reduction of free radical generation and metal detoxification, and they may explain the accumulation of aluminium in Alzheimer's disease.
- Full Text:
- Date Issued: 1998
- Authors: Limson, Janice L , Nyokong, Tebello , Daya, Santy
- Date: 1998
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/293323 , vital:57075 , xlink:href="https://doi.org/10.1111/j.1600-079X.1998.tb00361.x"
- Description: Melatonin, a pineal secretory product, and its precursors, tryptophan and serotonin, were examined for their metal binding affinities for both essential and toxic metals: aluminium, cadmium, copper, iron, lead, and zinc. An electrochemical technique, adsorptive stripping voltammetry, showed the varying abilities of melatonin and its precursors to bind the metals in situ. The results show that the following metal complexes were formed: aluminium with melatonin, tryptophan, and serotonin; cadmium with melatonin and tryptophan; copper with melatonin and serotonin; iron(III) with melatonin and serotonin; lead with melatonin, tryptophan, and serotonin; and zinc with melatonin and tryptophan. Iron(II) showed the formation of an in situ complex with tryptophan only. These studies suggest a further role for melatonin in the reduction of free radical generation and metal detoxification, and they may explain the accumulation of aluminium in Alzheimer's disease.
- Full Text:
- Date Issued: 1998
The invertebrates of temporary rivers in the Eastern Cape, South Africa
- Authors: Uys, Amanda Cloete
- Date: 1998
- Subjects: Rivers -- South Africa -- Eastern Cape Stream ecology -- South Africa -- Eastern Cape Freshwater invertebrates -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5628 , http://hdl.handle.net/10962/d1004908
- Description: Temporary rivers in dryland regions are subject to highly variable and unpredictable rainfall and flow, and are considered unstable systems relative to perennial rivers of temperate zones. Little is known of the ecology of South Africa's temporary rivers, despite their abundance. The research presented focusses on the aquatic invertebrates inhabiting intermittently-flowing rivers in the 'arid corridor' of the Eastern Cape, South Africa. The major aims of the work were: to investigate which invertebrates inhabit these rivers, how the fauna is affected by environmental variability at various spatial and temporal scales, whether or not a characteristic fauna can be associated with these rivers or the hydrological phases which characterise them, and to establish to what extent faunal overlap occurs between different temporary rivers and between natural and modified temporary and perennial rivers. Research results indicate that the fauna of the Eastern Cape temporary rivers shows little structure at the scales of investigation, and that communities are generally non-equilibrial in character. The major forces shaping the biota are considered to be physical rather than biological, and the most important of these are: present and antecedent hydrological conditions and their duration; time of year; and biotope character, extent and heterogeneity. Three groups of fauna were identified as inhabitants of the temporary rivers: 'residents', 'facultative taxa' and 'opportunist colonists'. Taxa were tentatively allocated to these groups. Faunal resemblance was fairly high in Eastern Cape temporary rivers at the level of family, but not at more detailed taxonomic levels. A comparison between faunas of temporary and perennial rivers in different regions of South Africa illustrated the influence of geographical location on diversity. Within regions, however, there was no indication that perennial rivers were more diverse than intermittent rivers. The relatively high diversities in temporary rivers in this study are attributed at least in part to the heterogeneity in surface water conditions over time. A conceptual framework envisioning a continuum between perennial and temporary rivers is proposed as a basis for ongoing research into these rivers. A supporting terminology for the range of river flow types in South Africa is presented.
- Full Text:
- Date Issued: 1998
- Authors: Uys, Amanda Cloete
- Date: 1998
- Subjects: Rivers -- South Africa -- Eastern Cape Stream ecology -- South Africa -- Eastern Cape Freshwater invertebrates -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5628 , http://hdl.handle.net/10962/d1004908
- Description: Temporary rivers in dryland regions are subject to highly variable and unpredictable rainfall and flow, and are considered unstable systems relative to perennial rivers of temperate zones. Little is known of the ecology of South Africa's temporary rivers, despite their abundance. The research presented focusses on the aquatic invertebrates inhabiting intermittently-flowing rivers in the 'arid corridor' of the Eastern Cape, South Africa. The major aims of the work were: to investigate which invertebrates inhabit these rivers, how the fauna is affected by environmental variability at various spatial and temporal scales, whether or not a characteristic fauna can be associated with these rivers or the hydrological phases which characterise them, and to establish to what extent faunal overlap occurs between different temporary rivers and between natural and modified temporary and perennial rivers. Research results indicate that the fauna of the Eastern Cape temporary rivers shows little structure at the scales of investigation, and that communities are generally non-equilibrial in character. The major forces shaping the biota are considered to be physical rather than biological, and the most important of these are: present and antecedent hydrological conditions and their duration; time of year; and biotope character, extent and heterogeneity. Three groups of fauna were identified as inhabitants of the temporary rivers: 'residents', 'facultative taxa' and 'opportunist colonists'. Taxa were tentatively allocated to these groups. Faunal resemblance was fairly high in Eastern Cape temporary rivers at the level of family, but not at more detailed taxonomic levels. A comparison between faunas of temporary and perennial rivers in different regions of South Africa illustrated the influence of geographical location on diversity. Within regions, however, there was no indication that perennial rivers were more diverse than intermittent rivers. The relatively high diversities in temporary rivers in this study are attributed at least in part to the heterogeneity in surface water conditions over time. A conceptual framework envisioning a continuum between perennial and temporary rivers is proposed as a basis for ongoing research into these rivers. A supporting terminology for the range of river flow types in South Africa is presented.
- Full Text:
- Date Issued: 1998
The larva of Rhinocoeta sanguinipes (Gory and Percheron 1833) (Coleoptera Scarabaeidae) description and phylogenetic inferences
- Smith, Tamara J, Perissinotto, Renzo, Villet, Martin H
- Authors: Smith, Tamara J , Perissinotto, Renzo , Villet, Martin H
- Date: 1998
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/453942 , vital:75299 , https://doi.org/10.1080/03946975.1998.10539365
- Description: The genus Rhinocoeta Burmeister 1842 is unusual among cetoniines, as adults do not feed on flowers or fruits. The biology and ecology of the genus are still completely unknown, and only for three of the six species representing the group have adults of both sexes been described. No information is available for the larval stages of any of the species. Here, we present the first discription of the third instar larvae of one of the species, Rhinocoeta sanguinipes (Gory and Percheron 1833). Cladistic analysis of larval characters confirms the primitive phylogenetic position of this species relative to a small sample of other South African cetoniines, and supports the hypothesis that the genus might belong in the subtribe Xiphoscelidina rather than the Cetoniina, thereby constituting part of a relict lineage derived directly from the most primitive Cetoniinae.
- Full Text:
- Date Issued: 1998
- Authors: Smith, Tamara J , Perissinotto, Renzo , Villet, Martin H
- Date: 1998
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/453942 , vital:75299 , https://doi.org/10.1080/03946975.1998.10539365
- Description: The genus Rhinocoeta Burmeister 1842 is unusual among cetoniines, as adults do not feed on flowers or fruits. The biology and ecology of the genus are still completely unknown, and only for three of the six species representing the group have adults of both sexes been described. No information is available for the larval stages of any of the species. Here, we present the first discription of the third instar larvae of one of the species, Rhinocoeta sanguinipes (Gory and Percheron 1833). Cladistic analysis of larval characters confirms the primitive phylogenetic position of this species relative to a small sample of other South African cetoniines, and supports the hypothesis that the genus might belong in the subtribe Xiphoscelidina rather than the Cetoniina, thereby constituting part of a relict lineage derived directly from the most primitive Cetoniinae.
- Full Text:
- Date Issued: 1998
The Marinkas Quellen Carbonatite Complex, southern Namibia: carbonatite magmatism with an uncontaminated depleted mantle signature in a continental setting
- Smithies, Robert H, Marsh, Julian S
- Authors: Smithies, Robert H , Marsh, Julian S
- Date: 1998
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149736 , vital:38879 , https://doi.org/10.1016/S0009-2541(98)00029-1
- Description: The Marinkas Quellen Carbonatite Complex, in southern Namibia, forms part of the ca. 490–550 Ma Kuboos-Bremen Igneous Province, a zone of alkaline igneous rocks that intrude the Mesoproterzoic to Paleoproterozoic Namaqualand Metamorphic Province and Neoproterozoic platform sediments. The carbonatite complex includes Ca-rich, Mg-rich and Fe-rich carbonatites as well as late ferrocarbonatite dykes that show extreme enrichments in Mn, REE and Th. Compared to most carbonatites, those at Marinkas Quellen are generally depleted in most trace elements, particularly Ba and the LREE.
- Full Text: false
- Date Issued: 1998
- Authors: Smithies, Robert H , Marsh, Julian S
- Date: 1998
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149736 , vital:38879 , https://doi.org/10.1016/S0009-2541(98)00029-1
- Description: The Marinkas Quellen Carbonatite Complex, in southern Namibia, forms part of the ca. 490–550 Ma Kuboos-Bremen Igneous Province, a zone of alkaline igneous rocks that intrude the Mesoproterzoic to Paleoproterozoic Namaqualand Metamorphic Province and Neoproterozoic platform sediments. The carbonatite complex includes Ca-rich, Mg-rich and Fe-rich carbonatites as well as late ferrocarbonatite dykes that show extreme enrichments in Mn, REE and Th. Compared to most carbonatites, those at Marinkas Quellen are generally depleted in most trace elements, particularly Ba and the LREE.
- Full Text: false
- Date Issued: 1998