Pragmatics teaching: on the development of learners’ linguistic competence among selected East London District schools
- Authors: Myoli, Ndileka
- Date: 2019
- Subjects: Pragmatics -- Study and teaching Language and languages -- Study and teaching
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/11232 , vital:37607
- Description: South Africa was listed amongst the countries with a percentage of students with achievement too low for estimation by “Progress International Results in Reading” in 2011. Meanwhile, there was also an indication that, high school learners in the Eastern Cape Province are highly challenged, as far as their ability to produce speech, as well as the ability to interpret meaning beyond what is literally suggested. Since such difficulties usually pose problems of content understanding, concerned researchers in the field of language took it upon themselves to investigate the underlying cause of the problem, in order to prevent more problems of pragmatics incompetence, such as, problems with social interaction that could retard one’s ability to function independently as an adult. While many studies have been conducted in the area of Pragmatics language competence, this study found it necessary to contribute around this debate. Since the study was two-fold, isiXhosa Home language learners of Grades 10 to 12 were investigated with an objective to determine the extent of pragmatic incompetence and the Teachers were investigated to determine the effectiveness of their teaching of pragmatics language. A number of 108 high school isiXhosa learners, of ages of between 16 and 18 years, from East London Directorate, 36 per Grade, from the three selected schools high schools, were sampled, 36 consisting of 18 males and 18 females per grade from each selected high school. 9 isiXhosa Home Language teachers of between the ages of 45 to 54 years were sampled from the selected schools. This study used an assessment test for the learners and the questionnaire for the teachers, as a means of data collection techniques. The study applied a high consideration of validity as well as of ethical matters in order to ensure the reliability of results. The study found that, isiXhosa Home language learners’ levels of pragmatic competence are high and with the appropriate use of good methods of pragmatics language teaching, learners’ pragmatics competence can develop.This study will be able to encourage syllabus designers to collaborate with subject teachers, beginning right at the inception of the syllabus planning. IsiXhosa language teachers can develop teaching material appropriate for their primary goal, which is the development of pragmatic competence. Further research is recommended to investigate more around this area of study to a point where isiXhosa Home language can be counted amongst the great and valued languages of South Africa.
- Full Text:
- Date Issued: 2019
- Authors: Myoli, Ndileka
- Date: 2019
- Subjects: Pragmatics -- Study and teaching Language and languages -- Study and teaching
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/11232 , vital:37607
- Description: South Africa was listed amongst the countries with a percentage of students with achievement too low for estimation by “Progress International Results in Reading” in 2011. Meanwhile, there was also an indication that, high school learners in the Eastern Cape Province are highly challenged, as far as their ability to produce speech, as well as the ability to interpret meaning beyond what is literally suggested. Since such difficulties usually pose problems of content understanding, concerned researchers in the field of language took it upon themselves to investigate the underlying cause of the problem, in order to prevent more problems of pragmatics incompetence, such as, problems with social interaction that could retard one’s ability to function independently as an adult. While many studies have been conducted in the area of Pragmatics language competence, this study found it necessary to contribute around this debate. Since the study was two-fold, isiXhosa Home language learners of Grades 10 to 12 were investigated with an objective to determine the extent of pragmatic incompetence and the Teachers were investigated to determine the effectiveness of their teaching of pragmatics language. A number of 108 high school isiXhosa learners, of ages of between 16 and 18 years, from East London Directorate, 36 per Grade, from the three selected schools high schools, were sampled, 36 consisting of 18 males and 18 females per grade from each selected high school. 9 isiXhosa Home Language teachers of between the ages of 45 to 54 years were sampled from the selected schools. This study used an assessment test for the learners and the questionnaire for the teachers, as a means of data collection techniques. The study applied a high consideration of validity as well as of ethical matters in order to ensure the reliability of results. The study found that, isiXhosa Home language learners’ levels of pragmatic competence are high and with the appropriate use of good methods of pragmatics language teaching, learners’ pragmatics competence can develop.This study will be able to encourage syllabus designers to collaborate with subject teachers, beginning right at the inception of the syllabus planning. IsiXhosa language teachers can develop teaching material appropriate for their primary goal, which is the development of pragmatic competence. Further research is recommended to investigate more around this area of study to a point where isiXhosa Home language can be counted amongst the great and valued languages of South Africa.
- Full Text:
- Date Issued: 2019
Job Engagement and Coping Strategies as Moderators of the Relationship between Occupational Stress and Burnout among Police Officers in the Eastern Cape, South Africa
- Authors: Dywili, Mtutuzeli
- Date: 2016
- Subjects: Police -- Job stress -- South Africa -- Eastern cape Job satisfaction -- South Africa -- Eastern Cape Employee motivation -- South Africa -- Eastern Cape Work -- Psychological aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/7697 , vital:30707
- Description: Police work in South Africa is demanding and stressful. Literature reveals that occupational stress when fully manifest amount to emotional burnout. It was therefore the aim of this study to examine job engagement and coping strategies as moderators of the relationship between occupational stress and burnout among police officers. Using a sample of 377 police officers from the Eastern Cape, South Africa, data was collected using various scales namely; the Effort – Reward Imbalance (ERI) questionnaire (occupational stress), the Maslach Burnout Inventory – General Survey MBI-GS (emotional burnout), the Utrecht Work Engagement Scale (job engagement), and the Coping Orientation to Problems Experienced questionnaire (coping strategies). Correlation tests and regression analysis were ministered on the data to test the research hypotheses. The major finding of the study indicated that job engagement and coping strategies collectively significantly moderate the relationship between occupational stress and emotional burnout. However, job engagement on its own was reported to be an insignificant moderator of the relationship between occupational stress and emotional burnout.
- Full Text:
- Date Issued: 2016
- Authors: Dywili, Mtutuzeli
- Date: 2016
- Subjects: Police -- Job stress -- South Africa -- Eastern cape Job satisfaction -- South Africa -- Eastern Cape Employee motivation -- South Africa -- Eastern Cape Work -- Psychological aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/7697 , vital:30707
- Description: Police work in South Africa is demanding and stressful. Literature reveals that occupational stress when fully manifest amount to emotional burnout. It was therefore the aim of this study to examine job engagement and coping strategies as moderators of the relationship between occupational stress and burnout among police officers. Using a sample of 377 police officers from the Eastern Cape, South Africa, data was collected using various scales namely; the Effort – Reward Imbalance (ERI) questionnaire (occupational stress), the Maslach Burnout Inventory – General Survey MBI-GS (emotional burnout), the Utrecht Work Engagement Scale (job engagement), and the Coping Orientation to Problems Experienced questionnaire (coping strategies). Correlation tests and regression analysis were ministered on the data to test the research hypotheses. The major finding of the study indicated that job engagement and coping strategies collectively significantly moderate the relationship between occupational stress and emotional burnout. However, job engagement on its own was reported to be an insignificant moderator of the relationship between occupational stress and emotional burnout.
- Full Text:
- Date Issued: 2016
Pro-active visualization of cyber security on a National Level : a South African case study
- Authors: Swart, Ignatius Petrus
- Date: 2015
- Subjects: Internet -- Security measures -- South Africa , Computer security -- Government policy -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4718 , http://hdl.handle.net/10962/d1017940
- Description: The need for increased national cyber security situational awareness is evident from the growing number of published national cyber security strategies. Governments are progressively seen as responsible for cyber security, but at the same time increasingly constrained by legal, privacy and resource considerations. Infrastructure and services that form part of the national cyber domain are often not under the control of government, necessitating the need for information sharing between governments and commercial partners. While sharing of security information is necessary, it typically requires considerable time to be implemented effectively. In an effort to decrease the time and effort required for cyber security situational awareness, this study considered commercially available data sources relating to a national cyber domain. Open source information is typically used by attackers to gather information with great success. An understanding of the data provided by these sources can also afford decision makers the opportunity to set priorities more effectively. Through the use of an adapted Joint Directors of Laboratories (JDL) fusion model, an experimental system was implemented that visualized the potential that open source intelligence could have on cyber situational awareness. Datasets used in the validation of the model contained information obtained from eight different data sources over a two year period with a focus on the South African .co.za sub domain. Over a million infrastructure devices were examined in this study along with information pertaining to a potential 88 million vulnerabilities on these devices. During the examination of data sources, a severe lack of information regarding the human aspect in cyber security was identified that led to the creation of a novel Personally Identifiable Information detection sensor (PII). The resultant two million records pertaining to PII in the South African domain were incorporated into the data fusion experiment for processing. The results of this processing are discussed in the three case studies. The results offered in this study aim to highlight how data fusion and effective visualization can serve to move national cyber security from a primarily reactive undertaking to a more pro-active model.
- Full Text:
- Date Issued: 2015
- Authors: Swart, Ignatius Petrus
- Date: 2015
- Subjects: Internet -- Security measures -- South Africa , Computer security -- Government policy -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4718 , http://hdl.handle.net/10962/d1017940
- Description: The need for increased national cyber security situational awareness is evident from the growing number of published national cyber security strategies. Governments are progressively seen as responsible for cyber security, but at the same time increasingly constrained by legal, privacy and resource considerations. Infrastructure and services that form part of the national cyber domain are often not under the control of government, necessitating the need for information sharing between governments and commercial partners. While sharing of security information is necessary, it typically requires considerable time to be implemented effectively. In an effort to decrease the time and effort required for cyber security situational awareness, this study considered commercially available data sources relating to a national cyber domain. Open source information is typically used by attackers to gather information with great success. An understanding of the data provided by these sources can also afford decision makers the opportunity to set priorities more effectively. Through the use of an adapted Joint Directors of Laboratories (JDL) fusion model, an experimental system was implemented that visualized the potential that open source intelligence could have on cyber situational awareness. Datasets used in the validation of the model contained information obtained from eight different data sources over a two year period with a focus on the South African .co.za sub domain. Over a million infrastructure devices were examined in this study along with information pertaining to a potential 88 million vulnerabilities on these devices. During the examination of data sources, a severe lack of information regarding the human aspect in cyber security was identified that led to the creation of a novel Personally Identifiable Information detection sensor (PII). The resultant two million records pertaining to PII in the South African domain were incorporated into the data fusion experiment for processing. The results of this processing are discussed in the three case studies. The results offered in this study aim to highlight how data fusion and effective visualization can serve to move national cyber security from a primarily reactive undertaking to a more pro-active model.
- Full Text:
- Date Issued: 2015
Pharmaceutical analysis and quality of complementary medicines : sceletium and associated products
- Patnala, Satya Siva Rama Ranganath Srinivas
- Authors: Patnala, Satya Siva Rama Ranganath Srinivas
- Date: 2007
- Subjects: Alternative medicine , Herbs -- Therapeutic use
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3872 , http://hdl.handle.net/10962/d1018263
- Description: There has been an upsurge in the use of Complementary and Alternate Medicines (CAMs) in both developed and developing countries. Although herbal medicines have been in use for many centuries, their quality, safety and efficacy are still of major concern. Many countries are in the process of integrating CAMs into conventional health care systems based on the knowledge and use of traditional medicines. The quality control (QC) of herbal products usually presents a formidable analytical challenge in view of the complexity of the constituents in plant material and the commercial non-availability of appropriate qualified reference standards. Sceletium, a genus belonging to the family Aizoaceae, has been reported to contain psychoactive alkaloids, specifically mesembrine, mesembrenone, mesembrenol and some other related alkaloids. Sceletium is marketed as dried plant powder and as phyto-pharmaceutical dosage forms. Sceletium products and plant material marketed through health shops and on the internet are associated with unjustified claims of specific therapeutic efficacy and may be of dubious quality. Validated analytical methods to estimate Sceletium alkaloids have not previously been reported in the scientific literature and the available methods have focused only on qualitative estimation. Furthermore, since appropriate markers were not commercially available for use as reference standards, a primary objective of this study was to isolate relevant compounds, qualify them as reference standards which could be applied to develop appropriate validated qualitative and quantitative analytical methods for fingerprinting and assay of Sceletium plant material and dosage forms. The alkaloidal markers mesembrine, mesembrenone and ∆⁷ mesembrenone were isolated by solvent extraction and chromatography from dried plant material. Mesembranol and epimesembranol were synthesised by hydrogenation of the isolated mesembrine using the catalyst platinum (IV) oxide and then further purified by semi-preparative column chromatography. All compounds were subjected to analysis by ¹H, ¹³C, 2-D nuclear magnetic resonance and liquid chromatography-tandem mass spectroscopy. Mesembrine was converted to hydrochloride crystals and mesembranol was isolated as crystals from the hydrogenation reaction mass. These compounds were analysed and characterised by X-ray crystallography. A relatively simple HPLC method for the separation and quantitative analysis of five relevant alkaloidal components in Sceletium was developed and validated. The method was applied to determine the alkaloids in plant material and dosage forms containing Sceletium. An LCMS method developed during the study provided accurate identification of the five relevant Sceletium alkaloids. The method was applied for the quantitative analysis and QC of Sceletium plant material and its dosage forms. This LCMS method was found to efficiently ionize the relevant alkaloidal markers in order to facilitate their detection, identification and quantification in Sceletium plant material as well as for the assay and QC of dosage forms containing Sceletium. The chemotaxonomy of some Sceletium species and commercially available Sceletium dosage forms were successfully studied by the LCMS method. The HPLC and LCMS methods were also used to monitor the bio-conversion of some of the alkaloids while processing the plant material as per traditional method of fermentation. Additionally a high resolution CZE method was developed for the separation of several Sceletium alkaloids in relatively short analysis times. This analytical method was used successfully to fingerprint the alkaloids and quantify mesembrine in Sceletium and its products. Sceletium species grown under varying conditions at different locations, when analyzed, showed major differences in their composition of alkaloids and an enormous difference was found to exist between the various species with respect to the presence and content of alkaloids. Sceletium and its products marketed through health shops and the internet may thus have problems with respect to the quality and related therapeutic efficacy. The QC of Sceletium presents a formidable challenge as Sceletium plants and products contain a complex mixture of compounds. The work presented herein contributes to a growing body of scientific knowledge to improve the QC standards of herbal medicines and also to provide vital information regarding the selection of plant species and information on the specific alkaloidal constituents to the cultivators of Sceletium and the manufacturers of its products.
- Full Text:
- Date Issued: 2007
- Authors: Patnala, Satya Siva Rama Ranganath Srinivas
- Date: 2007
- Subjects: Alternative medicine , Herbs -- Therapeutic use
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3872 , http://hdl.handle.net/10962/d1018263
- Description: There has been an upsurge in the use of Complementary and Alternate Medicines (CAMs) in both developed and developing countries. Although herbal medicines have been in use for many centuries, their quality, safety and efficacy are still of major concern. Many countries are in the process of integrating CAMs into conventional health care systems based on the knowledge and use of traditional medicines. The quality control (QC) of herbal products usually presents a formidable analytical challenge in view of the complexity of the constituents in plant material and the commercial non-availability of appropriate qualified reference standards. Sceletium, a genus belonging to the family Aizoaceae, has been reported to contain psychoactive alkaloids, specifically mesembrine, mesembrenone, mesembrenol and some other related alkaloids. Sceletium is marketed as dried plant powder and as phyto-pharmaceutical dosage forms. Sceletium products and plant material marketed through health shops and on the internet are associated with unjustified claims of specific therapeutic efficacy and may be of dubious quality. Validated analytical methods to estimate Sceletium alkaloids have not previously been reported in the scientific literature and the available methods have focused only on qualitative estimation. Furthermore, since appropriate markers were not commercially available for use as reference standards, a primary objective of this study was to isolate relevant compounds, qualify them as reference standards which could be applied to develop appropriate validated qualitative and quantitative analytical methods for fingerprinting and assay of Sceletium plant material and dosage forms. The alkaloidal markers mesembrine, mesembrenone and ∆⁷ mesembrenone were isolated by solvent extraction and chromatography from dried plant material. Mesembranol and epimesembranol were synthesised by hydrogenation of the isolated mesembrine using the catalyst platinum (IV) oxide and then further purified by semi-preparative column chromatography. All compounds were subjected to analysis by ¹H, ¹³C, 2-D nuclear magnetic resonance and liquid chromatography-tandem mass spectroscopy. Mesembrine was converted to hydrochloride crystals and mesembranol was isolated as crystals from the hydrogenation reaction mass. These compounds were analysed and characterised by X-ray crystallography. A relatively simple HPLC method for the separation and quantitative analysis of five relevant alkaloidal components in Sceletium was developed and validated. The method was applied to determine the alkaloids in plant material and dosage forms containing Sceletium. An LCMS method developed during the study provided accurate identification of the five relevant Sceletium alkaloids. The method was applied for the quantitative analysis and QC of Sceletium plant material and its dosage forms. This LCMS method was found to efficiently ionize the relevant alkaloidal markers in order to facilitate their detection, identification and quantification in Sceletium plant material as well as for the assay and QC of dosage forms containing Sceletium. The chemotaxonomy of some Sceletium species and commercially available Sceletium dosage forms were successfully studied by the LCMS method. The HPLC and LCMS methods were also used to monitor the bio-conversion of some of the alkaloids while processing the plant material as per traditional method of fermentation. Additionally a high resolution CZE method was developed for the separation of several Sceletium alkaloids in relatively short analysis times. This analytical method was used successfully to fingerprint the alkaloids and quantify mesembrine in Sceletium and its products. Sceletium species grown under varying conditions at different locations, when analyzed, showed major differences in their composition of alkaloids and an enormous difference was found to exist between the various species with respect to the presence and content of alkaloids. Sceletium and its products marketed through health shops and the internet may thus have problems with respect to the quality and related therapeutic efficacy. The QC of Sceletium presents a formidable challenge as Sceletium plants and products contain a complex mixture of compounds. The work presented herein contributes to a growing body of scientific knowledge to improve the QC standards of herbal medicines and also to provide vital information regarding the selection of plant species and information on the specific alkaloidal constituents to the cultivators of Sceletium and the manufacturers of its products.
- Full Text:
- Date Issued: 2007
An investigation into the neuroprotective properties of melatonin
- Authors: Southgate, Garrick Steven
- Date: 1999
- Subjects: Melatonin
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3900 , http://hdl.handle.net/10962/d1003959
- Description: Until the beginning of this decade the neurohormone, melatonin, had been considered as little more than a tranquillising hormone, responsible for regulating certain circadian and circannual rhythms. In the last eight years, a whole new dimension to melatonin’s role in biological organisms has emerged. In 1991 it was discovered [1,2] that melatonin exhibited antioxidant properties. Since then, many researchers [3,4] have found melatonin to be a powerful free radical scavenger and antioxidant. In the present study, the ability of melatonin to offer neuroprotection against glutamate, N-methyl-D-aspartate (NMDA), quinolinic acid (QA) and kainic acid (KA) (collectively referred to as the glutamate receptor agonists) was investigated. It was first shown that stress causes an increase in circulating glucocorticoid concentrations, which resulted in an increase the number of glutamate receptors on synaptic membranes in rat brain homogenate. Melatonin acted to reduce the number of glutamate receptors present on the synaptic membranes, implying that melatonin has neuroprotective properties, as overstimulation of the glutamate receptors leads to excitotoxicity and neurodegeneration. Further investigations showed that the glutamate receptor agonists induce neurodegeneration in primary neuronal cell cultures. Both co-treatment and posttreatment with melatonin against the glutamate receptor agonists, increased neuronal cell viability in a dose dependent manner. Melatonin also appeared to offer protection against quinolinic acid-induced neurodegeneration following intrahippocampal injections of quinolinic acid. The mechanism whereby melatonin offered this protection was investigated. The glutamate receptor agonists caused an increase in intracellular calcium concentrations, which is known [5] to be responsible for initiating the excitotoxic response. Melatonin had no effect on regulating intracellular calcium concentrations Additional studies indicated that melatonin was effective at scavenging superoxide radicals. Production of superoxide radicals was induced by the glutamate receptor agonists in primary neuronal cultures. Superoxide radicals induce lipid peroxidation, which involves the destruction of lipid membranes by chain reactions. By acting as an antioxidant, melatonin was able to reduce quinolinic acid-induced lipid peroxidation in rat brain homogenate, in a dose dependent manner. Melatonin was also effective at reducing lipid peroxidation induced by the glutamate receptor agonists in primary neuronal cultures. Melatonin therefore appeared to be offering neuroprotection by removing superoxide radicals and inhibiting lipid peroxidation. It had been reported [6] that melatonin inhibits nitric oxide synthase activity. This enzyme produces the free radical, nitric oxide, and can also produce superoxide radicals. Melatonin was able to reduce nitric oxide synthase activity in a dose dependent manner. This is a novel method of neuroprotection, as melatonin was now acting as an enzyme regulator. The results obtained demonstrate that melatonin offers neuroprotection against glutamate induced excitotoxicity, by removing free radicals and preventing lipid peroxidation. The neurohormone offers further protection by decreasing the activity of enzymes that aid in the neurotoxic cascade. Melatonin is the most potent naturally occurring free radical scavenger in the body [3]. During aging, the serum concentrations of melatonin decrease [7]. During the senescence of life, free radical damage to the body is at its highest [8], while at the same time melatonin concentrations are at their lowest. Melatonin therefore shows potential for the treatment of diseases and disorders that exhibit an excitotoxic pathology.
- Full Text:
- Date Issued: 1999
- Authors: Southgate, Garrick Steven
- Date: 1999
- Subjects: Melatonin
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3900 , http://hdl.handle.net/10962/d1003959
- Description: Until the beginning of this decade the neurohormone, melatonin, had been considered as little more than a tranquillising hormone, responsible for regulating certain circadian and circannual rhythms. In the last eight years, a whole new dimension to melatonin’s role in biological organisms has emerged. In 1991 it was discovered [1,2] that melatonin exhibited antioxidant properties. Since then, many researchers [3,4] have found melatonin to be a powerful free radical scavenger and antioxidant. In the present study, the ability of melatonin to offer neuroprotection against glutamate, N-methyl-D-aspartate (NMDA), quinolinic acid (QA) and kainic acid (KA) (collectively referred to as the glutamate receptor agonists) was investigated. It was first shown that stress causes an increase in circulating glucocorticoid concentrations, which resulted in an increase the number of glutamate receptors on synaptic membranes in rat brain homogenate. Melatonin acted to reduce the number of glutamate receptors present on the synaptic membranes, implying that melatonin has neuroprotective properties, as overstimulation of the glutamate receptors leads to excitotoxicity and neurodegeneration. Further investigations showed that the glutamate receptor agonists induce neurodegeneration in primary neuronal cell cultures. Both co-treatment and posttreatment with melatonin against the glutamate receptor agonists, increased neuronal cell viability in a dose dependent manner. Melatonin also appeared to offer protection against quinolinic acid-induced neurodegeneration following intrahippocampal injections of quinolinic acid. The mechanism whereby melatonin offered this protection was investigated. The glutamate receptor agonists caused an increase in intracellular calcium concentrations, which is known [5] to be responsible for initiating the excitotoxic response. Melatonin had no effect on regulating intracellular calcium concentrations Additional studies indicated that melatonin was effective at scavenging superoxide radicals. Production of superoxide radicals was induced by the glutamate receptor agonists in primary neuronal cultures. Superoxide radicals induce lipid peroxidation, which involves the destruction of lipid membranes by chain reactions. By acting as an antioxidant, melatonin was able to reduce quinolinic acid-induced lipid peroxidation in rat brain homogenate, in a dose dependent manner. Melatonin was also effective at reducing lipid peroxidation induced by the glutamate receptor agonists in primary neuronal cultures. Melatonin therefore appeared to be offering neuroprotection by removing superoxide radicals and inhibiting lipid peroxidation. It had been reported [6] that melatonin inhibits nitric oxide synthase activity. This enzyme produces the free radical, nitric oxide, and can also produce superoxide radicals. Melatonin was able to reduce nitric oxide synthase activity in a dose dependent manner. This is a novel method of neuroprotection, as melatonin was now acting as an enzyme regulator. The results obtained demonstrate that melatonin offers neuroprotection against glutamate induced excitotoxicity, by removing free radicals and preventing lipid peroxidation. The neurohormone offers further protection by decreasing the activity of enzymes that aid in the neurotoxic cascade. Melatonin is the most potent naturally occurring free radical scavenger in the body [3]. During aging, the serum concentrations of melatonin decrease [7]. During the senescence of life, free radical damage to the body is at its highest [8], while at the same time melatonin concentrations are at their lowest. Melatonin therefore shows potential for the treatment of diseases and disorders that exhibit an excitotoxic pathology.
- Full Text:
- Date Issued: 1999
Managing natural resources in a rural settlement in Peddie district
- Authors: Ainslie, Andrew
- Date: 1998
- Subjects: Conservation of natural resources -- South Africa -- Management , Natural resources -- South Africa -- Peddie District -- Management , Peddie (South Africa) -- Social conditions , Peddie (South Africa) -- History
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2110 , http://hdl.handle.net/10962/d1007462 , Conservation of natural resources -- South Africa -- Management , Natural resources -- South Africa -- Peddie District -- Management , Peddie (South Africa) -- Social conditions , Peddie (South Africa) -- History
- Description: This thesis is an account of the challenges people in Tyefu Location, Peddie District, and specifically in Gwabeni village, face in their attempts to manage their common pool natural resources. Taking my analytical cue from the literature which deals with the institutional dimensions of resource management in common property systems, I look at the impact of both outside influences and local dynamics on resource managing institutions at village level. I show how particular historical circumstances, including state interventions, led to the enclosure of Tyefu Location, and to the rapid increase in the population that had to be accommodated here. This placed enormous pressure on the natural resources of the area, and contributed to the emasculation of the local institutions responsible for overseeing resource management. The residents of the location adopted whatever strategies they could to ameliorate the depletion of natural resources in their villages. One 'traditional' strategy they have sought to emulate is to move their imizi (homesteads) away from areas where local resources has been exhausted. Given the finite area of land available to them, this strategy was only ever likely to be successful in the short-term. I analyse social, economic and institutional factors at village level that appear to act as disincentives to collective resource management activities. These factors include the social structure of the imizi and the socio-economic heterogeneity that exists between imizi in Gwabeni village. The varying degrees of household economic marginality that follow from this, together with the differential ownership of livestock and other possessions that decrease people's reliance on locally available natural resources, mean that the transaction costs that people would incur by contributing to collective resource management activities, differ widely. A primary cause of people's failure to engage in resource management at village level stems from the dispersion of the members of their imizi. This factor robs the village of decision makers and undermines the capacity of those left behind to make and implement resource management decisions. It results in the various members of imizi in the village having different orientations that dissipate the energy needed for collective action. It also fuels existing struggles, and creates new ones, over the meanings and uses of the term 'community'. I conclude by arguing that, in Tyefu Location, the management of natural resources is extremely difficult to co-ordinate, because such management is highly contested, undermined by differentiation among resource users, and subject to the attentions of weak village institutions that do not share a clear set of resource management objectives. , KMBT_363
- Full Text:
- Date Issued: 1998
- Authors: Ainslie, Andrew
- Date: 1998
- Subjects: Conservation of natural resources -- South Africa -- Management , Natural resources -- South Africa -- Peddie District -- Management , Peddie (South Africa) -- Social conditions , Peddie (South Africa) -- History
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2110 , http://hdl.handle.net/10962/d1007462 , Conservation of natural resources -- South Africa -- Management , Natural resources -- South Africa -- Peddie District -- Management , Peddie (South Africa) -- Social conditions , Peddie (South Africa) -- History
- Description: This thesis is an account of the challenges people in Tyefu Location, Peddie District, and specifically in Gwabeni village, face in their attempts to manage their common pool natural resources. Taking my analytical cue from the literature which deals with the institutional dimensions of resource management in common property systems, I look at the impact of both outside influences and local dynamics on resource managing institutions at village level. I show how particular historical circumstances, including state interventions, led to the enclosure of Tyefu Location, and to the rapid increase in the population that had to be accommodated here. This placed enormous pressure on the natural resources of the area, and contributed to the emasculation of the local institutions responsible for overseeing resource management. The residents of the location adopted whatever strategies they could to ameliorate the depletion of natural resources in their villages. One 'traditional' strategy they have sought to emulate is to move their imizi (homesteads) away from areas where local resources has been exhausted. Given the finite area of land available to them, this strategy was only ever likely to be successful in the short-term. I analyse social, economic and institutional factors at village level that appear to act as disincentives to collective resource management activities. These factors include the social structure of the imizi and the socio-economic heterogeneity that exists between imizi in Gwabeni village. The varying degrees of household economic marginality that follow from this, together with the differential ownership of livestock and other possessions that decrease people's reliance on locally available natural resources, mean that the transaction costs that people would incur by contributing to collective resource management activities, differ widely. A primary cause of people's failure to engage in resource management at village level stems from the dispersion of the members of their imizi. This factor robs the village of decision makers and undermines the capacity of those left behind to make and implement resource management decisions. It results in the various members of imizi in the village having different orientations that dissipate the energy needed for collective action. It also fuels existing struggles, and creates new ones, over the meanings and uses of the term 'community'. I conclude by arguing that, in Tyefu Location, the management of natural resources is extremely difficult to co-ordinate, because such management is highly contested, undermined by differentiation among resource users, and subject to the attentions of weak village institutions that do not share a clear set of resource management objectives. , KMBT_363
- Full Text:
- Date Issued: 1998
Authority, avoidances and marriage: an analysis of the position of Gcaleka women in Qwaninga, Willowvale District, Transkei
- Authors: Liebenberg, Alida
- Date: 1994
- Subjects: Marriage customs and rites -- South Africa -- Transkei , Xhosa (African people) -- Social life and customs , Women -- Developing countries
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2100 , http://hdl.handle.net/10962/d1002663 , Marriage customs and rites -- South Africa -- Transkei , Xhosa (African people) -- Social life and customs , Women -- Developing countries
- Description: Authority as it operates in the daily lives of married women in Gcaleka society is reinforced and maintained by a body of avoidances which women need to observe during their married lives. Avoidances constitute part of the control system in the society whereby wives are being 'kept in their place'. Avoidances do not only restrict her, but also safeguard her position and her interests. Lines of authority emerge through the process of interaction; the structure reveals itself as avoidances are acted out in time and space. This study was conducted in Qwaninga, an administrative area in the coastal area of the Willowvale district, Transkei. The research started out as a study of ritual impurity and the status of women in a traditional, 'red' Gcaleka society. It soon became clear that pollution practices and beliefs associated with women form part of a greater body of avoidances which women need to observe during their married lives. Avoidances entail economic, dietary, sexual, linguistic and spatial prohibitions; as well as restrictions concerning what a woman is supposed to wear, and her withdrawal from social life. These restrictions are enforced through certain ritual and other sanctions. Three forms of avoidances are identified in this study, and are discussed and analysed. Avoidances are found in the everyday male/female division in society; in the ways through which the wife shows respect towards her husband and her in-laws (especially her husband's ancestors); and in the reproductive situations a woman finds herself in from time to time. In many anthropological studies in the past women have often been hidden in the background. This study is an attempt to give women the prominence they should be given, to show that nonwestern women are not as subordinated as people in Western society like to assume. In Gcaleka society the authority structure affecting the position of women is not only based on a distinction being made between males and females. It will be shown that a finer authority structure operates in this society whereby gender as well as age and kinship distinctions are being made. These distinctions constitute a system of classification which is safeguarded and protected by the avoidances and other restrictions imposed on women.
- Full Text:
- Date Issued: 1994
- Authors: Liebenberg, Alida
- Date: 1994
- Subjects: Marriage customs and rites -- South Africa -- Transkei , Xhosa (African people) -- Social life and customs , Women -- Developing countries
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2100 , http://hdl.handle.net/10962/d1002663 , Marriage customs and rites -- South Africa -- Transkei , Xhosa (African people) -- Social life and customs , Women -- Developing countries
- Description: Authority as it operates in the daily lives of married women in Gcaleka society is reinforced and maintained by a body of avoidances which women need to observe during their married lives. Avoidances constitute part of the control system in the society whereby wives are being 'kept in their place'. Avoidances do not only restrict her, but also safeguard her position and her interests. Lines of authority emerge through the process of interaction; the structure reveals itself as avoidances are acted out in time and space. This study was conducted in Qwaninga, an administrative area in the coastal area of the Willowvale district, Transkei. The research started out as a study of ritual impurity and the status of women in a traditional, 'red' Gcaleka society. It soon became clear that pollution practices and beliefs associated with women form part of a greater body of avoidances which women need to observe during their married lives. Avoidances entail economic, dietary, sexual, linguistic and spatial prohibitions; as well as restrictions concerning what a woman is supposed to wear, and her withdrawal from social life. These restrictions are enforced through certain ritual and other sanctions. Three forms of avoidances are identified in this study, and are discussed and analysed. Avoidances are found in the everyday male/female division in society; in the ways through which the wife shows respect towards her husband and her in-laws (especially her husband's ancestors); and in the reproductive situations a woman finds herself in from time to time. In many anthropological studies in the past women have often been hidden in the background. This study is an attempt to give women the prominence they should be given, to show that nonwestern women are not as subordinated as people in Western society like to assume. In Gcaleka society the authority structure affecting the position of women is not only based on a distinction being made between males and females. It will be shown that a finer authority structure operates in this society whereby gender as well as age and kinship distinctions are being made. These distinctions constitute a system of classification which is safeguarded and protected by the avoidances and other restrictions imposed on women.
- Full Text:
- Date Issued: 1994
Studies in asymmetric synthesis
- Authors: Ravindran, Swarnam Shanthi
- Date: 1994
- Subjects: Asymmetric synthesis Chirality Organic compounds -- Synthesis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4352 , http://hdl.handle.net/10962/d1005017
- Description: The stereoselectivity of TiCI₄-catalysed Mukaiyama reactions of a camphor acetal-derived chiral silyl enol ether with a range of substituted aromatic aldehydes has been examined. The enantiomeric excess in each of the resulting ß-hydroxy ketones, determined by ¹H NMR spectroscopy using the lanthanide chiral shift reagent Pr(Etcf₃), ranged between 9 and 13%. The stereo-directing potential of the camphor acetal as a chiral auxiliary in the α-benzylation of carboxylate esters has been studied; the acids were chosen to illustrate substituent effects on asymmetric induction. The observed diastereoselectivity increased with increasing steric bulk of the ester group and α-benzylation of the tert-butylacetate derivative proceeded with 48% diastereoselectivity. It is proposed that the enolate adopts an endo-s-trans conformation in the transition state and preferential attack by the electrophile at the somewhat less hindered Si-face is supported by both the optical rotation data and computer modelling studies. Reductive cleavage and hydrolysis of one of the benzylated esters furnished known products from whose optical rotation the configuration of the major diastereomer was established. In order to improve the steric advantage of Si-facial attack, methods of increasing the steric bulk of the blocking group were explored. A novel 2,2-propylenedioxy hydroxycamphor acetal and its 3,3-propylenedioxy analogue were prepared. Selected carboxylate esters of these propylenedioxy acetals were subjected to α-benzylation and the 2,2-(propylenedioxy)-3-exo-tert-butylacetate derivative showed a diastereoselectivity of 57% during a-benzylation. Hydrolysis of the abenzylated phenylacetate analogue offered the known 2,3-diphenylpropanoic acid whose optical rotation indicated the preferred configuration at the new chiral centre to be (R), a result which is consistent with the proposed approach of the electrophile to the less hindered Re-face of theendo-s-trans enolate moiety and reflects an inversion of the configurational bias observed with 2-v exo-carboxylate analogues. Attempts to prepare the monocatechol acetal of the hydroxy camphor derivative although unsuccessful, led to the isolation of two novel dibornyl ethers whose structures were established by 1- and 2-D NMR spectroscopy. A study of novel applications of camphor-derived auxiliaries in the asymmetric synthesis of α-amino acids has been initiated. The several approaches tried led to the preparation of three novel dural glycine derivatives in good yield
- Full Text:
- Date Issued: 1994
- Authors: Ravindran, Swarnam Shanthi
- Date: 1994
- Subjects: Asymmetric synthesis Chirality Organic compounds -- Synthesis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4352 , http://hdl.handle.net/10962/d1005017
- Description: The stereoselectivity of TiCI₄-catalysed Mukaiyama reactions of a camphor acetal-derived chiral silyl enol ether with a range of substituted aromatic aldehydes has been examined. The enantiomeric excess in each of the resulting ß-hydroxy ketones, determined by ¹H NMR spectroscopy using the lanthanide chiral shift reagent Pr(Etcf₃), ranged between 9 and 13%. The stereo-directing potential of the camphor acetal as a chiral auxiliary in the α-benzylation of carboxylate esters has been studied; the acids were chosen to illustrate substituent effects on asymmetric induction. The observed diastereoselectivity increased with increasing steric bulk of the ester group and α-benzylation of the tert-butylacetate derivative proceeded with 48% diastereoselectivity. It is proposed that the enolate adopts an endo-s-trans conformation in the transition state and preferential attack by the electrophile at the somewhat less hindered Si-face is supported by both the optical rotation data and computer modelling studies. Reductive cleavage and hydrolysis of one of the benzylated esters furnished known products from whose optical rotation the configuration of the major diastereomer was established. In order to improve the steric advantage of Si-facial attack, methods of increasing the steric bulk of the blocking group were explored. A novel 2,2-propylenedioxy hydroxycamphor acetal and its 3,3-propylenedioxy analogue were prepared. Selected carboxylate esters of these propylenedioxy acetals were subjected to α-benzylation and the 2,2-(propylenedioxy)-3-exo-tert-butylacetate derivative showed a diastereoselectivity of 57% during a-benzylation. Hydrolysis of the abenzylated phenylacetate analogue offered the known 2,3-diphenylpropanoic acid whose optical rotation indicated the preferred configuration at the new chiral centre to be (R), a result which is consistent with the proposed approach of the electrophile to the less hindered Re-face of theendo-s-trans enolate moiety and reflects an inversion of the configurational bias observed with 2-v exo-carboxylate analogues. Attempts to prepare the monocatechol acetal of the hydroxy camphor derivative although unsuccessful, led to the isolation of two novel dibornyl ethers whose structures were established by 1- and 2-D NMR spectroscopy. A study of novel applications of camphor-derived auxiliaries in the asymmetric synthesis of α-amino acids has been initiated. The several approaches tried led to the preparation of three novel dural glycine derivatives in good yield
- Full Text:
- Date Issued: 1994
Die evolusie van nedersetting in die Sondagsriviervallei
- Authors: Potgieter, J M
- Date: 1953
- Subjects: Land settlement -- South Africa -- Sundays River Valley , Agriculture -- South Africa -- Sundays River Valley , Irrigation -- South Africa -- Eastern Cape -- Sundays River Valley
- Language: Afrikaans
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4875 , http://hdl.handle.net/10962/d1013041
- Description: Soos die titel aandui is hierdie verhandeling 'n volledige en noukeurige oorsig van die evolusie (ontwikkeling) van blanke nedersetting in die Sondagsriviervallei. Dis die eerste poging wat aangewend is om die ontwikkeling op alle gebiede van die grondlegging af tot op die huidige datum teen 'n geskiedkundige agtergrond te skilder. Maar dwarsdaur is daar getrag om 'n duidelike begrip van die interaksie van natuur en mens te handhaaf.
- Full Text:
- Date Issued: 1953
- Authors: Potgieter, J M
- Date: 1953
- Subjects: Land settlement -- South Africa -- Sundays River Valley , Agriculture -- South Africa -- Sundays River Valley , Irrigation -- South Africa -- Eastern Cape -- Sundays River Valley
- Language: Afrikaans
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4875 , http://hdl.handle.net/10962/d1013041
- Description: Soos die titel aandui is hierdie verhandeling 'n volledige en noukeurige oorsig van die evolusie (ontwikkeling) van blanke nedersetting in die Sondagsriviervallei. Dis die eerste poging wat aangewend is om die ontwikkeling op alle gebiede van die grondlegging af tot op die huidige datum teen 'n geskiedkundige agtergrond te skilder. Maar dwarsdaur is daar getrag om 'n duidelike begrip van die interaksie van natuur en mens te handhaaf.
- Full Text:
- Date Issued: 1953
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