A cognitive behavioural treatment program for chronic lower back pain: a case study approach
- Authors: Wohlman, Michael Avron
- Date: 2000
- Subjects: Backache -- Psychological aspects , Backache -- Treatment , Backache -- Treatment -- Case studies
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3087 , http://hdl.handle.net/10962/d1002596 , Backache -- Psychological aspects , Backache -- Treatment , Backache -- Treatment -- Case studies
- Description: A cognitive behavioural treatment program for chronic lower back pain was designed, implemented and evaluated. The outpatient treatment program included education sessions, goal setting, graded activity training, physical exercise, relaxation training, cognitive techniques, social skills training, and medication reduction. Three participants volunteered to participate in the eightweek treatment program. Of the three participants, only one completed the program successfully. The results were used to critically discuss and evaluate the literature. The successful participant showed significant improvement in activity levels, decrease in subjective levels of pain, as well as decreased levels of anxiety and depression. It was shown that correcting cognitive distortions (e.g. selective abstraction, catastrophising, misattribution) and challenging early maladaptive schemas of abandonment, emotional deprivation and emotional inhibition (Young, 1990) assisted in enhancing coping mechanisms and the belief that the pain episodes would be short-lived and could be controlled. There was considerable improvement for the second participant, although he chose to withdraw from the program prior to its completion. The components of the psycho-education, relaxation and stress management and exercise program were beneficial for him. The third participant failed to accept the treatment formulation, and did not engage collaboratively in the treatment program. The case is presented as a point for examining therapeutic ailures.
- Full Text:
- Date Issued: 2000
- Authors: Wohlman, Michael Avron
- Date: 2000
- Subjects: Backache -- Psychological aspects , Backache -- Treatment , Backache -- Treatment -- Case studies
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3087 , http://hdl.handle.net/10962/d1002596 , Backache -- Psychological aspects , Backache -- Treatment , Backache -- Treatment -- Case studies
- Description: A cognitive behavioural treatment program for chronic lower back pain was designed, implemented and evaluated. The outpatient treatment program included education sessions, goal setting, graded activity training, physical exercise, relaxation training, cognitive techniques, social skills training, and medication reduction. Three participants volunteered to participate in the eightweek treatment program. Of the three participants, only one completed the program successfully. The results were used to critically discuss and evaluate the literature. The successful participant showed significant improvement in activity levels, decrease in subjective levels of pain, as well as decreased levels of anxiety and depression. It was shown that correcting cognitive distortions (e.g. selective abstraction, catastrophising, misattribution) and challenging early maladaptive schemas of abandonment, emotional deprivation and emotional inhibition (Young, 1990) assisted in enhancing coping mechanisms and the belief that the pain episodes would be short-lived and could be controlled. There was considerable improvement for the second participant, although he chose to withdraw from the program prior to its completion. The components of the psycho-education, relaxation and stress management and exercise program were beneficial for him. The third participant failed to accept the treatment formulation, and did not engage collaboratively in the treatment program. The case is presented as a point for examining therapeutic ailures.
- Full Text:
- Date Issued: 2000
Development of the components of a low cost, distributed facial virtual conferencing system
- Authors: Panagou, Soterios
- Date: 2000 , 2011-11-10
- Subjects: Virtual computer systems , Virtual reality , Computer conferencing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4622 , http://hdl.handle.net/10962/d1006490 , Virtual computer systems , Virtual reality , Computer conferencing
- Description: This thesis investigates the development of a low cost, component based facial virtual conferencing system. The design is decomposed into an encoding phase and a decoding phase, which communicate with each other via a network connection. The encoding phase is composed of three components: model acquisition (which handles avatar generation), pose estimation and expression analysis. Audio is not considered part of the encoding and decoding process, and as such is not evaluated. The model acquisition component is implemented using a visual hull reconstruction algorithm that is able to reconstruct real-world objects using only sets of images of the object as input. The object to be reconstructed is assumed to lie in a bounding volume of voxels. The reconstruction process involves the following stages: - Space carving for basic shape extraction; - Isosurface extraction to remove voxels not part of the surface of the reconstruction; - Mesh connection to generate a closed, connected polyhedral mesh; - Texture generation. Texturing is achieved by Gouraud shading the reconstruction with a vertex colour map; - Mesh decimation to simplify the object. The original algorithm has complexity O(n), but suffers from an inability to reconstruct concave surfaces that do not form part of the visual hull of the object. A novel extension to this algorithm based on Normalised Cross Correlation (NCC) is proposed to overcome this problem. An extension to speed up traditional NCC evaluations is proposed which reduces the NCC search space from a 2D search problem down to a single evaluation. Pose estimation and expression analysis are performed by tracking six fiducial points on the face of a subject. A tracking algorithm is developed that uses Normalised Cross Correlation to facilitate robust tracking that is invariant to changing lighting conditions, rotations and scaling. Pose estimation involves the recovery of the head position and orientation through the tracking of the triangle formed by the subject's eyebrows and nose tip. A rule-based evaluation of points that are tracked around the subject's mouth forms the basis of the expression analysis. A user assisted feedback loop and caching mechanism is used to overcome tracking errors due to fast motion or occlusions. The NCC tracker is shown to achieve a tracking performance of 10 fps when tracking the six fiducial points. The decoding phase is divided into 3 tasks, namely: avatar movement, expression generation and expression management. Avatar movement is implemented using the base VR system. Expression generation is facilitated using a Vertex Interpolation Deformation method. A weighting system is proposed for expression management. Its function is to gradually transform from one expression to the next. The use of the vertex interpolation method allows real-time deformations of the avatar representation, achieving 16 fps when applied to a model consisting of 7500 vertices. An Expression Parameter Lookup Table (EPLT) facilitates an independent mapping between the two phases. It defines a list of generic expressions that are known to the system and associates an Expression ID with each one. For each generic expression, it relates the expression analysis rules for any subject with the expression generation parameters for any avatar model. The result is that facial expression replication between any subject and avatar combination can be performed by transferring only the Expression ID from the encoder application to the decoder application. The ideas developed in the thesis are demonstrated in an implementation using the CoRgi Virtual Reality system. It is shown that the virtual-conferencing application based on this design requires only a bandwidth of 2 Kbps. , Adobe Acrobat Pro 9.4.6 , Adobe Acrobat 9.46 Paper Capture Plug-in
- Full Text:
- Date Issued: 2000
- Authors: Panagou, Soterios
- Date: 2000 , 2011-11-10
- Subjects: Virtual computer systems , Virtual reality , Computer conferencing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4622 , http://hdl.handle.net/10962/d1006490 , Virtual computer systems , Virtual reality , Computer conferencing
- Description: This thesis investigates the development of a low cost, component based facial virtual conferencing system. The design is decomposed into an encoding phase and a decoding phase, which communicate with each other via a network connection. The encoding phase is composed of three components: model acquisition (which handles avatar generation), pose estimation and expression analysis. Audio is not considered part of the encoding and decoding process, and as such is not evaluated. The model acquisition component is implemented using a visual hull reconstruction algorithm that is able to reconstruct real-world objects using only sets of images of the object as input. The object to be reconstructed is assumed to lie in a bounding volume of voxels. The reconstruction process involves the following stages: - Space carving for basic shape extraction; - Isosurface extraction to remove voxels not part of the surface of the reconstruction; - Mesh connection to generate a closed, connected polyhedral mesh; - Texture generation. Texturing is achieved by Gouraud shading the reconstruction with a vertex colour map; - Mesh decimation to simplify the object. The original algorithm has complexity O(n), but suffers from an inability to reconstruct concave surfaces that do not form part of the visual hull of the object. A novel extension to this algorithm based on Normalised Cross Correlation (NCC) is proposed to overcome this problem. An extension to speed up traditional NCC evaluations is proposed which reduces the NCC search space from a 2D search problem down to a single evaluation. Pose estimation and expression analysis are performed by tracking six fiducial points on the face of a subject. A tracking algorithm is developed that uses Normalised Cross Correlation to facilitate robust tracking that is invariant to changing lighting conditions, rotations and scaling. Pose estimation involves the recovery of the head position and orientation through the tracking of the triangle formed by the subject's eyebrows and nose tip. A rule-based evaluation of points that are tracked around the subject's mouth forms the basis of the expression analysis. A user assisted feedback loop and caching mechanism is used to overcome tracking errors due to fast motion or occlusions. The NCC tracker is shown to achieve a tracking performance of 10 fps when tracking the six fiducial points. The decoding phase is divided into 3 tasks, namely: avatar movement, expression generation and expression management. Avatar movement is implemented using the base VR system. Expression generation is facilitated using a Vertex Interpolation Deformation method. A weighting system is proposed for expression management. Its function is to gradually transform from one expression to the next. The use of the vertex interpolation method allows real-time deformations of the avatar representation, achieving 16 fps when applied to a model consisting of 7500 vertices. An Expression Parameter Lookup Table (EPLT) facilitates an independent mapping between the two phases. It defines a list of generic expressions that are known to the system and associates an Expression ID with each one. For each generic expression, it relates the expression analysis rules for any subject with the expression generation parameters for any avatar model. The result is that facial expression replication between any subject and avatar combination can be performed by transferring only the Expression ID from the encoder application to the decoder application. The ideas developed in the thesis are demonstrated in an implementation using the CoRgi Virtual Reality system. It is shown that the virtual-conferencing application based on this design requires only a bandwidth of 2 Kbps. , Adobe Acrobat Pro 9.4.6 , Adobe Acrobat 9.46 Paper Capture Plug-in
- Full Text:
- Date Issued: 2000
Professional development in environmental education in Zanzibar, Tanzania: distances encountered in a semi-distance learning course
- Authors: Heylings, Phillippa Frances
- Date: 2000
- Subjects: Environmental education -- Tanzania -- Zanzibar Distance education -- Tanzania -- Zanzibar Environmental education Distance education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1715 , http://hdl.handle.net/10962/d1003598
- Description: In Zanzibar, in 1995, opportunities for professional development in environmental education were minimal. Yet the demand for professional development was high, especially because of an emphasis on formal qualifications in the country. Credibility was afforded to forms of professional development, aimed at creating more ‘experts’. Ongoing environmental education practice was not achieving its objectives. Into this setting, which was culturally and socio-politically different from the South African context where it was developed, I introduced the Rhodes University Certificate and Gold Fields Participatory Course in Environmental Education (RU/GF); a non-formal, counter-hegemonic course which encouraged critical reflection on the dominant orientations to environmental education practice – including professional development. I used critical ethnographic and action research methods to explore my praxiological interest, the adaptation of the RU/GF curriculum to the Zanzibar context. During the research process, a decision was made to formally accredit the RU/GF course. This decision did not alter the course orientation or the learning process but opened up possibilities for future curriculum development processes. It allowed the students both a formal qualification necessary for status and promotion, and participation in a learning process that challenged the dominant paradigm on professional development and status from within the socio-political context. The research took on a reflexive orientation to research and environmental education. Through a dialectical development of theory, method and results, several important issues emerged. These deal with the ‘distances’ encountered in attempting to address some of the perceived dichotomies in professional development in environmental education through semi-distance learning: the distances between status and learning; the need for career upgrading and the type of learning considered appropriate for professional development in environmental education; the non-quantifiable aims associated with a reflexive orientation to professional development and formal assessment demands for measurable criteria; the democratisation of open-entry courses and the elitism of restricted access; the focus on individual growth and the attainment of a normative grade; theory and practice; and finally distances between learner, text and language. The research supports similar findings emerging from evaluation of the RU/GF course in South Africa and resonates with, and contributes to, issues concerning professional development in environmental education being considered internationally.
- Full Text:
- Date Issued: 2000
- Authors: Heylings, Phillippa Frances
- Date: 2000
- Subjects: Environmental education -- Tanzania -- Zanzibar Distance education -- Tanzania -- Zanzibar Environmental education Distance education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1715 , http://hdl.handle.net/10962/d1003598
- Description: In Zanzibar, in 1995, opportunities for professional development in environmental education were minimal. Yet the demand for professional development was high, especially because of an emphasis on formal qualifications in the country. Credibility was afforded to forms of professional development, aimed at creating more ‘experts’. Ongoing environmental education practice was not achieving its objectives. Into this setting, which was culturally and socio-politically different from the South African context where it was developed, I introduced the Rhodes University Certificate and Gold Fields Participatory Course in Environmental Education (RU/GF); a non-formal, counter-hegemonic course which encouraged critical reflection on the dominant orientations to environmental education practice – including professional development. I used critical ethnographic and action research methods to explore my praxiological interest, the adaptation of the RU/GF curriculum to the Zanzibar context. During the research process, a decision was made to formally accredit the RU/GF course. This decision did not alter the course orientation or the learning process but opened up possibilities for future curriculum development processes. It allowed the students both a formal qualification necessary for status and promotion, and participation in a learning process that challenged the dominant paradigm on professional development and status from within the socio-political context. The research took on a reflexive orientation to research and environmental education. Through a dialectical development of theory, method and results, several important issues emerged. These deal with the ‘distances’ encountered in attempting to address some of the perceived dichotomies in professional development in environmental education through semi-distance learning: the distances between status and learning; the need for career upgrading and the type of learning considered appropriate for professional development in environmental education; the non-quantifiable aims associated with a reflexive orientation to professional development and formal assessment demands for measurable criteria; the democratisation of open-entry courses and the elitism of restricted access; the focus on individual growth and the attainment of a normative grade; theory and practice; and finally distances between learner, text and language. The research supports similar findings emerging from evaluation of the RU/GF course in South Africa and resonates with, and contributes to, issues concerning professional development in environmental education being considered internationally.
- Full Text:
- Date Issued: 2000
An investigation into dopamine-melatonin interactions in the rat Corpus striatum and pineal gland: a possible pineal-striatal axis
- Authors: Boyd, Clinton Shane
- Date: 2000
- Subjects: Pineal gland -- Research Melatonin Dopamine -- Physiological effect Dopamine Brain chemistry Rats -- Physiology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3906 , http://hdl.handle.net/10962/d1003965
- Description: Dysfunction of central dopaminergic systems has been implicated in neuroendocrine, neurodegenerative and psychiatric disorders. Monoamine oxidase and catechol-Omethyltransferase represent the key catabolic enzymes of dopamine, terminating neurotransmission following synaptic release of this catecholamine. Thus, both enzymes have been associated with the pathology of dopaminergic systems and represent therapeutic targets elf enormous clinical importance. Some neuroendocrine and circadian effects of melatonin have been attributed to an antidopamimetic effect of this pineal hormone in the hypothalamus and pituitary. Furthermore, both melatonin and dopamine modulate the behavioural output of the mesencephalic dopaminergic pathways of the basal ganglia, including movement disorders. However, the biochemical basis for the tonic inhibitory effect of melatonin in the nigro-striatal pathway has been poorly delineated. Thus, this study determined whether melatonin influences dopaminergic function in the corpus striatum of the Wistar rat by modulating monoamine oxidase and catecholO- methyltransferase activity. Reciprocally, the putative existence of an intrapineal dopaminergic system was investigated by determining the effect of selective dopaminergic agents, R-( -)apomorphine, haloperidol and dopamine, on indole metabolism of the pineal gland. The akinetic state of drug-induced catalepsy was employed as an animal model of Parkinson's disease to probe the neurotransmitter systems involved in the behavioural effects of melatonin. Indole metabolism was a reliable indicator of state-dependent metabolic fluxes in pineal gland function. These included a robust diurnal and seasonal variation in N-acetylserotonin and melatonin biosynthesis, and photoperiod- and drug-induced alterations of Inftabolism. The predominant changes could be attributed to an effect on serotonin N-acetyltransferase activity and/or the melatoninl5-methoxytryptophol ratio. Pineal 5-methoxyindole biosynthesis was determined primarily by the bioavailability of the corresponding 5-hydroxyindole and its affinity for hydroxyindole-O-methyltransferase. Evidence was found for the negative feedback or paracrine control of pineal indole metabolism by melatonin. A high inter-individual variability was observed in the biosynthesis of N-acetylserotonin and melatonin biosynthesis, and the weight of the pineal glands. Accordingly, the rats could be classified as either high or low capacity producers of these two indoles. R-(-)-apomorphine and dopamine in vitro, but not acute haloperidol in vivo, had dose- and phase-dependent effects on pineal indole metabolism. The predominant effect was a suppression of the scotophase-dependent induction ofN-acetylserotonin and melatonin biosynthesis by dopamine and R-( -)-apomorphine. It is postulated that these agonists inhibited nocturnal N-acetyltransferase activity via postsynaptic pineal D2 or D2-like receptors. The observed modulatory nature of the intrapineal dopaminergic system suggests that dopamine may be involved in the long-term regulation of pineal indole biosynthesis. Several lines of evidence are presented that the activity of striatal monoamine oxidase A and catechol-O-methyltransferase, represented predominantly by the soluble isoform, is statedependent and regulated in vivo by endogenous melatonin. Firstly, both enzymes showed a daynight variation in activity. Secondly, acute and subchronic administration and photoperiod manipulation studies indicated that both exogenous and endogenous melatonin inhibited each enzyme in a chronotypic fashion, with a more robust effect against catechol- -methyltransferase. The intensity of the in vivo effects was critically dependent on the dose, duration, route and the phase-timing of administration during the light dark cycle, and the length of the exposure to constant light. Melatonin in vitro had no effect on basal or Mg2+ -induced catechol-Omethyltransferase activity. Thus, it is proposed that the in vivo effects of the hormone can be attributed to a time-dependent change in the amount of active molecules of this enzyme. In contrast, melatonin and numerous other endogenous indolic compounds were found to be reversible inhibitors of striatal monoamine oxidase A in vitro. Structure-activity modeling revealed that the 5-methoxy moiety on the indole nucleus and substitution of the free primary amine of these compounds were the principal determinants of the potency and time-dependency of inhibition. Thus melatonin most likely has a direct inhibitory effect in vivo at the level of the active site of monoamine oxidase A. Exogenous melatonin alone had no cataleptogenic potential whereas a variety of behavioural responses were observed following intraperitoneal administration of y-hydroxybutyrate. The latter responses were state-dependent with day-night variations in intensity. Furthermore, yhydroxybutyrate stimulated melatonin biosynthesis during the photophase both in vitro and in vivo. These results point to a possible involvement of melatonin in the behavioural and neurochemical effects of y-hydroxybutyrate. Thus the general conclusion is that dopamine and melatonin display functional antagonism at the level of the pineal gland and corpus striatum of the Wistar rats. Therefore melatonin may be an important homeostatic modulator of dopaminergic neurotransmission throu~out the central nervous system. Furthermore, the putative existence of a functional pineal-striatal axis would greatly strengthen the argument for a holistic concept of brain homeostasis. The ability of endogenous melatonin to regulate monoamine oxidase A and catechol-O-methyltransferase may represent an alternative strategy for the treatment of disorders associated with these enzymes.
- Full Text:
- Date Issued: 2000
- Authors: Boyd, Clinton Shane
- Date: 2000
- Subjects: Pineal gland -- Research Melatonin Dopamine -- Physiological effect Dopamine Brain chemistry Rats -- Physiology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3906 , http://hdl.handle.net/10962/d1003965
- Description: Dysfunction of central dopaminergic systems has been implicated in neuroendocrine, neurodegenerative and psychiatric disorders. Monoamine oxidase and catechol-Omethyltransferase represent the key catabolic enzymes of dopamine, terminating neurotransmission following synaptic release of this catecholamine. Thus, both enzymes have been associated with the pathology of dopaminergic systems and represent therapeutic targets elf enormous clinical importance. Some neuroendocrine and circadian effects of melatonin have been attributed to an antidopamimetic effect of this pineal hormone in the hypothalamus and pituitary. Furthermore, both melatonin and dopamine modulate the behavioural output of the mesencephalic dopaminergic pathways of the basal ganglia, including movement disorders. However, the biochemical basis for the tonic inhibitory effect of melatonin in the nigro-striatal pathway has been poorly delineated. Thus, this study determined whether melatonin influences dopaminergic function in the corpus striatum of the Wistar rat by modulating monoamine oxidase and catecholO- methyltransferase activity. Reciprocally, the putative existence of an intrapineal dopaminergic system was investigated by determining the effect of selective dopaminergic agents, R-( -)apomorphine, haloperidol and dopamine, on indole metabolism of the pineal gland. The akinetic state of drug-induced catalepsy was employed as an animal model of Parkinson's disease to probe the neurotransmitter systems involved in the behavioural effects of melatonin. Indole metabolism was a reliable indicator of state-dependent metabolic fluxes in pineal gland function. These included a robust diurnal and seasonal variation in N-acetylserotonin and melatonin biosynthesis, and photoperiod- and drug-induced alterations of Inftabolism. The predominant changes could be attributed to an effect on serotonin N-acetyltransferase activity and/or the melatoninl5-methoxytryptophol ratio. Pineal 5-methoxyindole biosynthesis was determined primarily by the bioavailability of the corresponding 5-hydroxyindole and its affinity for hydroxyindole-O-methyltransferase. Evidence was found for the negative feedback or paracrine control of pineal indole metabolism by melatonin. A high inter-individual variability was observed in the biosynthesis of N-acetylserotonin and melatonin biosynthesis, and the weight of the pineal glands. Accordingly, the rats could be classified as either high or low capacity producers of these two indoles. R-(-)-apomorphine and dopamine in vitro, but not acute haloperidol in vivo, had dose- and phase-dependent effects on pineal indole metabolism. The predominant effect was a suppression of the scotophase-dependent induction ofN-acetylserotonin and melatonin biosynthesis by dopamine and R-( -)-apomorphine. It is postulated that these agonists inhibited nocturnal N-acetyltransferase activity via postsynaptic pineal D2 or D2-like receptors. The observed modulatory nature of the intrapineal dopaminergic system suggests that dopamine may be involved in the long-term regulation of pineal indole biosynthesis. Several lines of evidence are presented that the activity of striatal monoamine oxidase A and catechol-O-methyltransferase, represented predominantly by the soluble isoform, is statedependent and regulated in vivo by endogenous melatonin. Firstly, both enzymes showed a daynight variation in activity. Secondly, acute and subchronic administration and photoperiod manipulation studies indicated that both exogenous and endogenous melatonin inhibited each enzyme in a chronotypic fashion, with a more robust effect against catechol- -methyltransferase. The intensity of the in vivo effects was critically dependent on the dose, duration, route and the phase-timing of administration during the light dark cycle, and the length of the exposure to constant light. Melatonin in vitro had no effect on basal or Mg2+ -induced catechol-Omethyltransferase activity. Thus, it is proposed that the in vivo effects of the hormone can be attributed to a time-dependent change in the amount of active molecules of this enzyme. In contrast, melatonin and numerous other endogenous indolic compounds were found to be reversible inhibitors of striatal monoamine oxidase A in vitro. Structure-activity modeling revealed that the 5-methoxy moiety on the indole nucleus and substitution of the free primary amine of these compounds were the principal determinants of the potency and time-dependency of inhibition. Thus melatonin most likely has a direct inhibitory effect in vivo at the level of the active site of monoamine oxidase A. Exogenous melatonin alone had no cataleptogenic potential whereas a variety of behavioural responses were observed following intraperitoneal administration of y-hydroxybutyrate. The latter responses were state-dependent with day-night variations in intensity. Furthermore, yhydroxybutyrate stimulated melatonin biosynthesis during the photophase both in vitro and in vivo. These results point to a possible involvement of melatonin in the behavioural and neurochemical effects of y-hydroxybutyrate. Thus the general conclusion is that dopamine and melatonin display functional antagonism at the level of the pineal gland and corpus striatum of the Wistar rats. Therefore melatonin may be an important homeostatic modulator of dopaminergic neurotransmission throu~out the central nervous system. Furthermore, the putative existence of a functional pineal-striatal axis would greatly strengthen the argument for a holistic concept of brain homeostasis. The ability of endogenous melatonin to regulate monoamine oxidase A and catechol-O-methyltransferase may represent an alternative strategy for the treatment of disorders associated with these enzymes.
- Full Text:
- Date Issued: 2000
Materials in flexible learning teacher education courses in environmental education : an evaluative case study
- Authors: Molose, Vivian Innotantia
- Date: 2000
- Subjects: Environmental education -- Study and teaching Environmental education -- Study and teaching -- Evaluation Environmental education -- South Africa -- Study and teaching
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1672 , http://hdl.handle.net/10962/d1003555
- Description: The study aimed at researching the role of materials in flexible learning teacher education courses, specifically looking at the Eastern Cape Teacher Course as a case study. The research aimed at exploring how courses and materials were developed, selected, used and adapted or redeveloped so as to support the course orientation and the intended outcomes. I did this with the hope that my research might inform the process of improving the role of course materials in flexible learning teacher education courses. I did a naturalistic enquiry within which I interviewed 39 participants (teachers and teacher educators) and two course co-ordinators. I also analysed documents such as the course materials, nine participants' journals and seven of their assignments. The observation notes compiled during the early days of the course were not used as a main source of data but as support to data sources mentioned above. Questionnaires were handed out to all the course participants, i.e. course co-ordinators, tutors and student participants. The questionnaires were intended as a means for pre interview and post interview reflection for interviewees. Through this research, I have learnt a lot about the role of materials in professional development courses, including the importance of mediation of materials and their overt use during course sessions, the importance of providing and encouraging a culture of reading through time allocation during contact sessions, through discussions on materials, and also through providing orientating comm~nts on materials rather than just handing them out to participants. Readings that are more focussed do better to motivate participants to interact with them.
- Full Text:
- Date Issued: 2000
- Authors: Molose, Vivian Innotantia
- Date: 2000
- Subjects: Environmental education -- Study and teaching Environmental education -- Study and teaching -- Evaluation Environmental education -- South Africa -- Study and teaching
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1672 , http://hdl.handle.net/10962/d1003555
- Description: The study aimed at researching the role of materials in flexible learning teacher education courses, specifically looking at the Eastern Cape Teacher Course as a case study. The research aimed at exploring how courses and materials were developed, selected, used and adapted or redeveloped so as to support the course orientation and the intended outcomes. I did this with the hope that my research might inform the process of improving the role of course materials in flexible learning teacher education courses. I did a naturalistic enquiry within which I interviewed 39 participants (teachers and teacher educators) and two course co-ordinators. I also analysed documents such as the course materials, nine participants' journals and seven of their assignments. The observation notes compiled during the early days of the course were not used as a main source of data but as support to data sources mentioned above. Questionnaires were handed out to all the course participants, i.e. course co-ordinators, tutors and student participants. The questionnaires were intended as a means for pre interview and post interview reflection for interviewees. Through this research, I have learnt a lot about the role of materials in professional development courses, including the importance of mediation of materials and their overt use during course sessions, the importance of providing and encouraging a culture of reading through time allocation during contact sessions, through discussions on materials, and also through providing orientating comm~nts on materials rather than just handing them out to participants. Readings that are more focussed do better to motivate participants to interact with them.
- Full Text:
- Date Issued: 2000
Making sense of ʺessenceʺ : a critical examination of the adequacy of the modern philosophical conception of ʺessenceʺ
- Authors: Ross, Allison
- Date: 2000
- Subjects: Essentialism (Philosophy)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2720 , http://hdl.handle.net/10962/d1002850 , Essentialism (Philosophy)
- Description: The idea that some sub-set of the properties of an object captures what it is to be that thing i.e. that it has an essence which is there to be discovered and about which we can be mistaken - is a commonsense assumption that we use all the time. However, philosophers of this century have regarded the realism about essence with skepticism, arguing that we impose essences on things by the way we define our concepts as opposed to discovering them. Essences are supposedly characteristics of our concepts rather than of objects in the world. This was the orthodox view until a group of philosophers of language developed the theory of direct reference. They claimed that proper names and certain other words refer non-connotatively which entails that the real properties of objects are crucial to the establishment of the reference of such terms. It can be shown that the properties involved in reference determination must be all and only the necessary properties of those objects. This discovery has been taken to mark the rehabilitation of the notion of essence, with an object’s essence being taken to be that set of properties which it must have in all possible worlds in which it exists. I will argue that the theory of direct reference is correct up to the point at which it assimilates the necessary properties of objects to their essences. I will show that the set of an object’s necessary properties cannot fulfill the role reserved for the concept of essence in metaphysical hypotheses concerning the nature of objects. I will go on to show that a sub-set of a thing’s necessary properties can fulfill this role and I will suggest that we identify the members of this sub-set by testing their ability to furnish the kinds of explanations we expect from essences. I will demonstrate how this can be done using the Aristotelian idea that the notion of essence is required in order to explain how it is that objects can persist through change.
- Full Text:
- Date Issued: 2000
- Authors: Ross, Allison
- Date: 2000
- Subjects: Essentialism (Philosophy)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2720 , http://hdl.handle.net/10962/d1002850 , Essentialism (Philosophy)
- Description: The idea that some sub-set of the properties of an object captures what it is to be that thing i.e. that it has an essence which is there to be discovered and about which we can be mistaken - is a commonsense assumption that we use all the time. However, philosophers of this century have regarded the realism about essence with skepticism, arguing that we impose essences on things by the way we define our concepts as opposed to discovering them. Essences are supposedly characteristics of our concepts rather than of objects in the world. This was the orthodox view until a group of philosophers of language developed the theory of direct reference. They claimed that proper names and certain other words refer non-connotatively which entails that the real properties of objects are crucial to the establishment of the reference of such terms. It can be shown that the properties involved in reference determination must be all and only the necessary properties of those objects. This discovery has been taken to mark the rehabilitation of the notion of essence, with an object’s essence being taken to be that set of properties which it must have in all possible worlds in which it exists. I will argue that the theory of direct reference is correct up to the point at which it assimilates the necessary properties of objects to their essences. I will show that the set of an object’s necessary properties cannot fulfill the role reserved for the concept of essence in metaphysical hypotheses concerning the nature of objects. I will go on to show that a sub-set of a thing’s necessary properties can fulfill this role and I will suggest that we identify the members of this sub-set by testing their ability to furnish the kinds of explanations we expect from essences. I will demonstrate how this can be done using the Aristotelian idea that the notion of essence is required in order to explain how it is that objects can persist through change.
- Full Text:
- Date Issued: 2000
Settler women's experiences of fear, illness and isolation, with particular reference to the Eastern Cape Frontier, 1820-1890
- Authors: Dampier, Helen
- Date: 2000
- Subjects: Women -- South Africa -- History , Women -- South Africa -- Eastern Cape -- Social conditions , Women -- South Africa -- Eastern Cape -- History , British settlers of 1820 (South Africa) , Frontier and pioneer life -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2537 , http://hdl.handle.net/10962/d1002389 , Women -- South Africa -- History , Women -- South Africa -- Eastern Cape -- Social conditions , Women -- South Africa -- Eastern Cape -- History , British settlers of 1820 (South Africa) , Frontier and pioneer life -- South Africa
- Description: This thesis is an exploration of diaries and letters written by middle-class English-speaking settler women living on the Eastern Cape frontier between 1820 and 1890. By according primacy to these women’s experiences and perceptions, it aims for a greater understanding of women’s encounters with the frontier, and how these were articulated in their personal writing. An emphasis on the recurrent themes of ill-health, fearfulness and solitude undermines the popular myth of the brave, conquering, invincible pioneers which dominates settler historiography to date. The tensions felt by white women living on the frontier disrupted their identities as middle-class Victorian ‘ladies’, and as a result these women either constantly re-established a sense of self, or absorbed some aspects of the Eastern Cape, and thus redefined themselves. Settler women’s experiences of the frontier changed little during the seventy year period spanned by this study, indicating that frontier life led to a rigidification and reinforcement of old, familiar values and behaviours. Rather than adapting to and embracing their new surroundings, settler women sought to duplicate accepted, conventional Victorian ideals and customs. White Victorian women identified themselves as refined, civilized, moral and respectable, and perceived Africa and Africans as untamed, immoral, uncivilized and threatening. To keep these menacing, destabilizing forces at bay, settler women attempted to recreate ‘home’ in the Eastern Cape; to domesticate the frontier by rendering it as familiar and predictable as possible. The fear, illness and solitariness that characterise settler women’s personal writings manifest their attempts to eliminate alienating difference, and record their refusal to truly engage with the frontier landscape and its inhabitants.
- Full Text:
- Date Issued: 2000
- Authors: Dampier, Helen
- Date: 2000
- Subjects: Women -- South Africa -- History , Women -- South Africa -- Eastern Cape -- Social conditions , Women -- South Africa -- Eastern Cape -- History , British settlers of 1820 (South Africa) , Frontier and pioneer life -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2537 , http://hdl.handle.net/10962/d1002389 , Women -- South Africa -- History , Women -- South Africa -- Eastern Cape -- Social conditions , Women -- South Africa -- Eastern Cape -- History , British settlers of 1820 (South Africa) , Frontier and pioneer life -- South Africa
- Description: This thesis is an exploration of diaries and letters written by middle-class English-speaking settler women living on the Eastern Cape frontier between 1820 and 1890. By according primacy to these women’s experiences and perceptions, it aims for a greater understanding of women’s encounters with the frontier, and how these were articulated in their personal writing. An emphasis on the recurrent themes of ill-health, fearfulness and solitude undermines the popular myth of the brave, conquering, invincible pioneers which dominates settler historiography to date. The tensions felt by white women living on the frontier disrupted their identities as middle-class Victorian ‘ladies’, and as a result these women either constantly re-established a sense of self, or absorbed some aspects of the Eastern Cape, and thus redefined themselves. Settler women’s experiences of the frontier changed little during the seventy year period spanned by this study, indicating that frontier life led to a rigidification and reinforcement of old, familiar values and behaviours. Rather than adapting to and embracing their new surroundings, settler women sought to duplicate accepted, conventional Victorian ideals and customs. White Victorian women identified themselves as refined, civilized, moral and respectable, and perceived Africa and Africans as untamed, immoral, uncivilized and threatening. To keep these menacing, destabilizing forces at bay, settler women attempted to recreate ‘home’ in the Eastern Cape; to domesticate the frontier by rendering it as familiar and predictable as possible. The fear, illness and solitariness that characterise settler women’s personal writings manifest their attempts to eliminate alienating difference, and record their refusal to truly engage with the frontier landscape and its inhabitants.
- Full Text:
- Date Issued: 2000
An evaluation of the life science curriculum in Namibia and its development through stakeholders' perceptions of ʺlearner centred educationʺ
- Authors: Kristensen, Jesper Olsson
- Date: 2000
- Subjects: Life science project Curriculum evaluation -- Namibia Environmental education Educational change -- Namibia Life sciences -- Study and teaching -- Evaluation
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1527 , http://hdl.handle.net/10962/d1003409
- Description: Following Independence in 1991 Namibia embarked on a major reform of the entire education system. The reform was perceived as a way of redressing the apartheid legacy and bringing about a democratic learner centred education for all. At the same time the reform was also seen as a prime vehicle to bring about sustainable development through incorporating relevant environmental education into various carrier subjects. One such carrier has been the subject Life Science, which is compulsory from Grade 8 to Grade 10. The Life Science Project was a joint venture between the Ministry of Education and Ibis, a Danish Development NGO, established to develop and support the implementation of Life Science in junior secondary schools. This half-thesis is an evaluation of the Life Science Project through an analysis of the central assumptions on which the Life Science curriculum is based and by investigating different stakeholders’ perceptions and understanding of the learner centred approach adopted by the curriculum. Three questions have guided this research: 1. Are there curriculum models that are more conducive for reform and change than others? 2. Do stakeholders and curriculum developers in Namibia understand the theory of social constructivism, and the systemic implications such an approach has for the education system? 3. Which approach to environmental education complements a transformative curriculum and the changes outlined in policy? From the research carried out in this half-thesis, it would appear that the Namibian education system and the Life Science curriculum suffers from what could be termed “ideological confusion”. Confusion in the sense that there are marked inconsistencies between policy and praxis, between the stated goals and aims of the reform and the curriculum designed to achieve these. This confusion is further exacerbated by various stakeholders’ different interpretations of both policy and the systemic implications the reform policy has on education. In this half-thesis I argue that embarking on an objectives driven model of curriculum cannot bring about change and transformation of the Namibian education system. I further argue that, by not having considered and implemented the necessary systemic changes to the education system, Namibia has, in fact, developed a child centred education system which is fundamentally different from a learner centred education system. Finally, I argue that environmental education, through the subject Life Science, set within an objectives driven, Child Centred Education system is inappropriate for and unable to address the need for developing an environmentally literate citizenry who are able to take informed decisions in order to address the environmental crisis and bring forth a more sustainable future.
- Full Text:
- Date Issued: 2000
- Authors: Kristensen, Jesper Olsson
- Date: 2000
- Subjects: Life science project Curriculum evaluation -- Namibia Environmental education Educational change -- Namibia Life sciences -- Study and teaching -- Evaluation
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1527 , http://hdl.handle.net/10962/d1003409
- Description: Following Independence in 1991 Namibia embarked on a major reform of the entire education system. The reform was perceived as a way of redressing the apartheid legacy and bringing about a democratic learner centred education for all. At the same time the reform was also seen as a prime vehicle to bring about sustainable development through incorporating relevant environmental education into various carrier subjects. One such carrier has been the subject Life Science, which is compulsory from Grade 8 to Grade 10. The Life Science Project was a joint venture between the Ministry of Education and Ibis, a Danish Development NGO, established to develop and support the implementation of Life Science in junior secondary schools. This half-thesis is an evaluation of the Life Science Project through an analysis of the central assumptions on which the Life Science curriculum is based and by investigating different stakeholders’ perceptions and understanding of the learner centred approach adopted by the curriculum. Three questions have guided this research: 1. Are there curriculum models that are more conducive for reform and change than others? 2. Do stakeholders and curriculum developers in Namibia understand the theory of social constructivism, and the systemic implications such an approach has for the education system? 3. Which approach to environmental education complements a transformative curriculum and the changes outlined in policy? From the research carried out in this half-thesis, it would appear that the Namibian education system and the Life Science curriculum suffers from what could be termed “ideological confusion”. Confusion in the sense that there are marked inconsistencies between policy and praxis, between the stated goals and aims of the reform and the curriculum designed to achieve these. This confusion is further exacerbated by various stakeholders’ different interpretations of both policy and the systemic implications the reform policy has on education. In this half-thesis I argue that embarking on an objectives driven model of curriculum cannot bring about change and transformation of the Namibian education system. I further argue that, by not having considered and implemented the necessary systemic changes to the education system, Namibia has, in fact, developed a child centred education system which is fundamentally different from a learner centred education system. Finally, I argue that environmental education, through the subject Life Science, set within an objectives driven, Child Centred Education system is inappropriate for and unable to address the need for developing an environmentally literate citizenry who are able to take informed decisions in order to address the environmental crisis and bring forth a more sustainable future.
- Full Text:
- Date Issued: 2000
The development of a pro forma document for use in police rape investigations in South Africa
- Authors: Netto, Lauren Joy
- Date: 2000
- Subjects: Interviewing in law enforcement , Criminal investigation , Police questioning -- Forms , Rape -- Investigation -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3031 , http://hdl.handle.net/10962/d1002540 , Interviewing in law enforcement , Criminal investigation , Police questioning -- Forms , Rape -- Investigation -- South Africa
- Description: This research developed a pro forma document for use in police rape investigations in South Africa. The immediate context for the research is the alarmingly high incidence of rape in South Africa. The rape statistics vary to an extent, largely due to the fact that a large proportion of the rapes that occur in South Africa are not reported to the police. These statistics expose the limited success of the South African Police Services (SAPS) in terms of investigating rape cases in this country, as well as the public perception of the effectiveness of the South African Police Services in this regard as evidenced by the non or under-reporting of rape in South Africa. The pro forma document is an investigative tool designed to standardise and systematise rape investigations by providing set guidelines for obtaining the essential information about each rape case. This is a prerequisite for Tender profiling, which involves predicting the relationship between offence and offender variables. Profiling can only be successful if the investigator obtains all the information about a crime. Hence the pro forma document, as an investigative instrument designed to access essential information about a crime, is a key requirement for the development of informed and accurate profiles of offenders. As a standardised form, the document will allow for systematic and thorough rape investigations in South Africa. The researcher employed the qualitative methodology of action research. This entailed involving the participants in all stages of the research process. The data was collected by means of focus group interviews with detectives from the Serious and Violent Crimes Unit and the Child Protection Unit in Grahamstown. Additional sources of data were various investigative documents that originated from a number of different countries. Analysis of the data followed a number of procedural steps specifically suggested for focus group interview research and involved a process of coding. The codes identified during the analysis provided the foundation for the items that were included in the pro forma document. In keeping with the action research approach, the participants were caned upon to evaluate the progress of the research after the initial data collection and analysis were completed, and a draft version of the pro forma document had been compiled. This feedback provided another source of data which contained suggestions for amendments to the pro forma document which the researcher implemented. The research process was hindered to a certain extent by the unpredictable nature of police work which influenced the data gathering procedure. This could point to a possible limitation of the research. Furthermore, the aim of the research was to develop a pro forma document for use in rape investigations in South Africa. This aim did not encompass marketing the document. Herein lies another possible limitation of the research in that the document has not yet been used and tested in real cases. A discussion of the research process includes issues involved in practically implementing the pro forma document in rape investigations.
- Full Text:
- Date Issued: 2000
- Authors: Netto, Lauren Joy
- Date: 2000
- Subjects: Interviewing in law enforcement , Criminal investigation , Police questioning -- Forms , Rape -- Investigation -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3031 , http://hdl.handle.net/10962/d1002540 , Interviewing in law enforcement , Criminal investigation , Police questioning -- Forms , Rape -- Investigation -- South Africa
- Description: This research developed a pro forma document for use in police rape investigations in South Africa. The immediate context for the research is the alarmingly high incidence of rape in South Africa. The rape statistics vary to an extent, largely due to the fact that a large proportion of the rapes that occur in South Africa are not reported to the police. These statistics expose the limited success of the South African Police Services (SAPS) in terms of investigating rape cases in this country, as well as the public perception of the effectiveness of the South African Police Services in this regard as evidenced by the non or under-reporting of rape in South Africa. The pro forma document is an investigative tool designed to standardise and systematise rape investigations by providing set guidelines for obtaining the essential information about each rape case. This is a prerequisite for Tender profiling, which involves predicting the relationship between offence and offender variables. Profiling can only be successful if the investigator obtains all the information about a crime. Hence the pro forma document, as an investigative instrument designed to access essential information about a crime, is a key requirement for the development of informed and accurate profiles of offenders. As a standardised form, the document will allow for systematic and thorough rape investigations in South Africa. The researcher employed the qualitative methodology of action research. This entailed involving the participants in all stages of the research process. The data was collected by means of focus group interviews with detectives from the Serious and Violent Crimes Unit and the Child Protection Unit in Grahamstown. Additional sources of data were various investigative documents that originated from a number of different countries. Analysis of the data followed a number of procedural steps specifically suggested for focus group interview research and involved a process of coding. The codes identified during the analysis provided the foundation for the items that were included in the pro forma document. In keeping with the action research approach, the participants were caned upon to evaluate the progress of the research after the initial data collection and analysis were completed, and a draft version of the pro forma document had been compiled. This feedback provided another source of data which contained suggestions for amendments to the pro forma document which the researcher implemented. The research process was hindered to a certain extent by the unpredictable nature of police work which influenced the data gathering procedure. This could point to a possible limitation of the research. Furthermore, the aim of the research was to develop a pro forma document for use in rape investigations in South Africa. This aim did not encompass marketing the document. Herein lies another possible limitation of the research in that the document has not yet been used and tested in real cases. A discussion of the research process includes issues involved in practically implementing the pro forma document in rape investigations.
- Full Text:
- Date Issued: 2000
The political significance of Winnie-Madikazela Mandela's position in the African National Congress
- Authors: Motseta, Sello
- Date: 2000
- Subjects: African National Congress , Mandela, Winnie , South Africa -- Politics and government -- 1994-
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2810 , http://hdl.handle.net/10962/d1003020 , African National Congress , Mandela, Winnie , South Africa -- Politics and government -- 1994-
- Description: Winnie Mandela has endured so many scandals over the last ten years that she has acquired a reputation for being untouchable. It is therefore ironic that there are those who feel that "the ANC want to act against Winnie not because of her human rights record, but for her outspoken criticism of the government's inability to deliver houses, thwart crime and testing our feelings on the death penalty." This assessment is instructive because in the "... turbulent years of the 1980s, she was a hero, a living martyr to the black liberation cause and despite the discomforts inflicted on her by her perpetrators, she revelled in the role" (Sparks, 1994:15). But Winnie Madikazela-Mandela, who was a Deputy Minister before being dismissed and who has had to appear before the TRC because of allegations that she was responsible for the death of teenage activist Stompie Seipei, has nevertheless been able to make a political comeback. The thesis therefore sets out to examine the rationale behind the State President's (he did not hold this title then) decision to take a considerable risk in standing by Winnie Madikazela-Mandela (they were at the time married) during her trial on charges of kidnapping in 1991. Even after her conviction, Mandela wrote that "as far as I was concerned, verdict or no verdict, her innocence was not in doubt." This unstinting loyalty was replicated elsewhere. Commenting on her acquittal on the assault charges, ANC Youth League President, Peter Mokaba, said: "What was taken away from her as a result of these false allegations must now be given back". He described the Appellate Division decision as "a political sentence" saying: "It has nothing to do with whether she was guilty or not."3 The ANC has established a practice of accommodating dissidents within its structures and has survived complex challenges during its years in exile by doing so. But political commentators are now asking whether the political cost will prove to be too great.
- Full Text:
- Date Issued: 2000
- Authors: Motseta, Sello
- Date: 2000
- Subjects: African National Congress , Mandela, Winnie , South Africa -- Politics and government -- 1994-
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2810 , http://hdl.handle.net/10962/d1003020 , African National Congress , Mandela, Winnie , South Africa -- Politics and government -- 1994-
- Description: Winnie Mandela has endured so many scandals over the last ten years that she has acquired a reputation for being untouchable. It is therefore ironic that there are those who feel that "the ANC want to act against Winnie not because of her human rights record, but for her outspoken criticism of the government's inability to deliver houses, thwart crime and testing our feelings on the death penalty." This assessment is instructive because in the "... turbulent years of the 1980s, she was a hero, a living martyr to the black liberation cause and despite the discomforts inflicted on her by her perpetrators, she revelled in the role" (Sparks, 1994:15). But Winnie Madikazela-Mandela, who was a Deputy Minister before being dismissed and who has had to appear before the TRC because of allegations that she was responsible for the death of teenage activist Stompie Seipei, has nevertheless been able to make a political comeback. The thesis therefore sets out to examine the rationale behind the State President's (he did not hold this title then) decision to take a considerable risk in standing by Winnie Madikazela-Mandela (they were at the time married) during her trial on charges of kidnapping in 1991. Even after her conviction, Mandela wrote that "as far as I was concerned, verdict or no verdict, her innocence was not in doubt." This unstinting loyalty was replicated elsewhere. Commenting on her acquittal on the assault charges, ANC Youth League President, Peter Mokaba, said: "What was taken away from her as a result of these false allegations must now be given back". He described the Appellate Division decision as "a political sentence" saying: "It has nothing to do with whether she was guilty or not."3 The ANC has established a practice of accommodating dissidents within its structures and has survived complex challenges during its years in exile by doing so. But political commentators are now asking whether the political cost will prove to be too great.
- Full Text:
- Date Issued: 2000
The development of a WAIS-III short form for use in South Africa
- Authors: Rust, Annegret L
- Date: 2000
- Subjects: Wechsler Adult Intelligence Scale , Intelligence tests -- South Africa , Wechsler Adult Intelligence Scale -- South Africa
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3047 , http://hdl.handle.net/10962/d1002556 , Wechsler Adult Intelligence Scale , Intelligence tests -- South Africa , Wechsler Adult Intelligence Scale -- South Africa
- Description: The Wechsler Adult Intelligence Scale - 3rd Edition (WAIS-III) is the newest of the internationally recognised Wechsler family of intelligence tests. It has been improved in terms of its psychometric properties, neuropsychological assessment abilities and its content. This test is in the process of being standardised by the Human Sciences Research Council (HSRC) in South Africa. As the adapted South African version will be available shortly for use in the multicultural circumstances of South Africa, the application of the various aspects of this test needs to be investigated. This test is very comprehensive and thorough, however its one disadvantage is that it takes on average three hours to administer in its entirety. Thus there is a need to find ways in which to abbreviate the test for particular purposes when time is limited, for example in research, brief clinical assessments or neuropsychological screenings. The concept of abbreviating tests, including the earlier Wechsler intelligence test can be traced back to 1917, when it was asked if all the items on the Binet-Simon scale were required to give an accurate assessment of IQ (Levy, 1968). Since then there have been many short form suggestions made, with many different considerations in mind. These can be divided into two main approaches or methods. Firstly, the number of subtests of the scale can be reduced. Thus with the WAIS-III which consists of 14 subtests in total, an option is to use, for example only four of the subtests to get an estimate of a person's IQ. Secondly, the number of items in each subtest can be reduced. Thus only half the items or even only a third of the items on a subtest can be administered to get an estimate of the persons' performance on each subtest and in this way estimate their overall IQ. Both methods have been used on the WAIS and WAIS-R, although the reduction of the subtests is favoured. Both should now be validated and considered for use with the WATS-III in South Africa. Wechsler tests and their constituent subtests have been found to be differentially effected by race, education, language and socio-economic status (Kaufman, McLean & Reynolds, 1988; Nell 1999). These differences have also been found to impact on the short forms which are suggested, as certain subtests are considered to be more biased towards particular groups than others. Vocabulary and Block Design in particular bias testees who are not as westernised or acculturated towards a largely American and European culture (Kaufman, McLean & Reynolds, 1988). These differences, although often ascribed to race, language or socio-economic status can best be understood more broadly in terms of degree of acculturation (i.e. westernisation) (Shuttleworth-Jordan, 1996) and test-wiseness (Nell, 1999). In South Africa in particular, with its extreme cultural diversity these factors need to be carefully considered when developing short forms. In the present study the development of a short form appropriate to South Africa's diverse cultural circumstances will be approached, through a sample which has been stratified according to gender, first language (English vs. African), quality of schooling received (Private/Model C vs. DET) and level of education achieved (Matric vs. Graduate). Both a subtest reduction method and an item reduction method will be considered to arrive at a short form. The subtest reduction method will be considered further in an attempt to clarify which subtests would be more or less appropriate to include in a short form considering group differences. Finally the thesis will develop suggestions as to which short forms would be best for use in South Africa.
- Full Text:
- Date Issued: 2000
- Authors: Rust, Annegret L
- Date: 2000
- Subjects: Wechsler Adult Intelligence Scale , Intelligence tests -- South Africa , Wechsler Adult Intelligence Scale -- South Africa
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3047 , http://hdl.handle.net/10962/d1002556 , Wechsler Adult Intelligence Scale , Intelligence tests -- South Africa , Wechsler Adult Intelligence Scale -- South Africa
- Description: The Wechsler Adult Intelligence Scale - 3rd Edition (WAIS-III) is the newest of the internationally recognised Wechsler family of intelligence tests. It has been improved in terms of its psychometric properties, neuropsychological assessment abilities and its content. This test is in the process of being standardised by the Human Sciences Research Council (HSRC) in South Africa. As the adapted South African version will be available shortly for use in the multicultural circumstances of South Africa, the application of the various aspects of this test needs to be investigated. This test is very comprehensive and thorough, however its one disadvantage is that it takes on average three hours to administer in its entirety. Thus there is a need to find ways in which to abbreviate the test for particular purposes when time is limited, for example in research, brief clinical assessments or neuropsychological screenings. The concept of abbreviating tests, including the earlier Wechsler intelligence test can be traced back to 1917, when it was asked if all the items on the Binet-Simon scale were required to give an accurate assessment of IQ (Levy, 1968). Since then there have been many short form suggestions made, with many different considerations in mind. These can be divided into two main approaches or methods. Firstly, the number of subtests of the scale can be reduced. Thus with the WAIS-III which consists of 14 subtests in total, an option is to use, for example only four of the subtests to get an estimate of a person's IQ. Secondly, the number of items in each subtest can be reduced. Thus only half the items or even only a third of the items on a subtest can be administered to get an estimate of the persons' performance on each subtest and in this way estimate their overall IQ. Both methods have been used on the WAIS and WAIS-R, although the reduction of the subtests is favoured. Both should now be validated and considered for use with the WATS-III in South Africa. Wechsler tests and their constituent subtests have been found to be differentially effected by race, education, language and socio-economic status (Kaufman, McLean & Reynolds, 1988; Nell 1999). These differences have also been found to impact on the short forms which are suggested, as certain subtests are considered to be more biased towards particular groups than others. Vocabulary and Block Design in particular bias testees who are not as westernised or acculturated towards a largely American and European culture (Kaufman, McLean & Reynolds, 1988). These differences, although often ascribed to race, language or socio-economic status can best be understood more broadly in terms of degree of acculturation (i.e. westernisation) (Shuttleworth-Jordan, 1996) and test-wiseness (Nell, 1999). In South Africa in particular, with its extreme cultural diversity these factors need to be carefully considered when developing short forms. In the present study the development of a short form appropriate to South Africa's diverse cultural circumstances will be approached, through a sample which has been stratified according to gender, first language (English vs. African), quality of schooling received (Private/Model C vs. DET) and level of education achieved (Matric vs. Graduate). Both a subtest reduction method and an item reduction method will be considered to arrive at a short form. The subtest reduction method will be considered further in an attempt to clarify which subtests would be more or less appropriate to include in a short form considering group differences. Finally the thesis will develop suggestions as to which short forms would be best for use in South Africa.
- Full Text:
- Date Issued: 2000
Theatre voice as metaphor : the advocacy of a praxis based on the centrality of voice to performance
- Authors: Mills, Elizabeth
- Date: 2000
- Subjects: Voice , Voice culture , Acting
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2141 , http://hdl.handle.net/10962/d1002373 , Voice , Voice culture , Acting
- Description: This study proposes a view of theatre voice as central to performance. It proposes a shift in paradigm through the foregrounding of the function of theatre voice as one of the creative strands of the theatre matrix. The function of theatre voice becomes a theatrical function. Theatre is created in the voice and, therefore, any act of theatre should include conscious questions about the meanings that are, or can be evoked through the voice in theatre. A second thrust to this study is that theatre voice practice should be included in, and theatre voice practitioners should actively engage in, broader debates about theatre. Introduction: The idea that the voice in performance is the enactment of conscious theatrical choices is set up through the notion of the theatrical use of the voice. The introduction outlines the kinds of performance contexts in which a theatrical use of the voice takes shape. This includes an assessment of the degree to which the specific South African context of the writer is useful to questions about a theatrical use of the voice. The concepts which are central to such a view of theatre voice are expanded. These are: the theatrical agency of the actor, theatre voice, the theatrical use of the voice and praxis. Selected examples from local and other productions are offered to illustrate a range of interpretive possibilities open to the voice when considered, in the first instance, as performance. Chapter one: The actor’s relationship with voice is explored through the notion of actor agency. Historically, actors were theatrically empowered by a closer involvement with playwriting, staging, apprenticeship forms of actor training and theatre management. It is argued that the emergence of the director as a new theatrical agent has diminished this actor agency. On the other hand, the introduction of a realist acting methodology has given the actor autonomy of craft, empowering the actor in unprecedented ways. The theatrical agency of actors, directors and theatre voice practitioners is explored as influencing the status and the perception of theatre voice within theatre. The proposal of the centrality of voice to performance is dependent on the agency of actors, directors and theatre voice practitioners. Chapter two: It is argued that an Aristotelian Poetics of Voice has, under the influence of realism, developed into a “Poetics of the Self”. The paradigmatic shift proposed through a view of the voice as central to theatre, is explored through a post realist, intertextuality of voice. This includes a re-consideration of the contemporary theatre voice notion of the “natural” voice. Chapter three: Cicely Berry’s work, with particular reference to The Actor and his Text (1987), is analysed in terms of realism and the theatrical use of the voice. A second focus in the analysis of Berry’s work supports the argument that voice practitioners theorise positions for theatre voice even though their texts are practical and technically orientated. Berry’s work is singled out here because the contemporary practice of the Central School tradition is the generic tradition of South African English theatre voice practice. Chapter four: Strategies and constructs are proposed in support of the centrality of voice to the theatre. Ways of realising a theatrical use of the voice are also suggested. This is based on a shift in the way in which practitioners think about theatre voice. In the first instance, it is suggested that practitioners move beyond positions of polarity and actively embrace that which is contradictory in theatre and theatre voice practice. Secondly, a traditional hermeneutic understanding of the interpretation of voice is challenged. Thirdly, the use of metaphor which is pertinent to actors, directors and voice practitioners is explored as a means to vocal action. Concrete examples of the creative use of the voice, are provided through the sonic texts of Performance Writing. By way of conclusion, some ideas are offered about the issue of empowering the actor in a theatrical use of the voice. This study is intended to contribute to a theoretical and practical debate which will promote the argument for the centrality of voice to performance.
- Full Text:
- Date Issued: 2000
Theatre voice as metaphor : the advocacy of a praxis based on the centrality of voice to performance
- Authors: Mills, Elizabeth
- Date: 2000
- Subjects: Voice , Voice culture , Acting
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2141 , http://hdl.handle.net/10962/d1002373 , Voice , Voice culture , Acting
- Description: This study proposes a view of theatre voice as central to performance. It proposes a shift in paradigm through the foregrounding of the function of theatre voice as one of the creative strands of the theatre matrix. The function of theatre voice becomes a theatrical function. Theatre is created in the voice and, therefore, any act of theatre should include conscious questions about the meanings that are, or can be evoked through the voice in theatre. A second thrust to this study is that theatre voice practice should be included in, and theatre voice practitioners should actively engage in, broader debates about theatre. Introduction: The idea that the voice in performance is the enactment of conscious theatrical choices is set up through the notion of the theatrical use of the voice. The introduction outlines the kinds of performance contexts in which a theatrical use of the voice takes shape. This includes an assessment of the degree to which the specific South African context of the writer is useful to questions about a theatrical use of the voice. The concepts which are central to such a view of theatre voice are expanded. These are: the theatrical agency of the actor, theatre voice, the theatrical use of the voice and praxis. Selected examples from local and other productions are offered to illustrate a range of interpretive possibilities open to the voice when considered, in the first instance, as performance. Chapter one: The actor’s relationship with voice is explored through the notion of actor agency. Historically, actors were theatrically empowered by a closer involvement with playwriting, staging, apprenticeship forms of actor training and theatre management. It is argued that the emergence of the director as a new theatrical agent has diminished this actor agency. On the other hand, the introduction of a realist acting methodology has given the actor autonomy of craft, empowering the actor in unprecedented ways. The theatrical agency of actors, directors and theatre voice practitioners is explored as influencing the status and the perception of theatre voice within theatre. The proposal of the centrality of voice to performance is dependent on the agency of actors, directors and theatre voice practitioners. Chapter two: It is argued that an Aristotelian Poetics of Voice has, under the influence of realism, developed into a “Poetics of the Self”. The paradigmatic shift proposed through a view of the voice as central to theatre, is explored through a post realist, intertextuality of voice. This includes a re-consideration of the contemporary theatre voice notion of the “natural” voice. Chapter three: Cicely Berry’s work, with particular reference to The Actor and his Text (1987), is analysed in terms of realism and the theatrical use of the voice. A second focus in the analysis of Berry’s work supports the argument that voice practitioners theorise positions for theatre voice even though their texts are practical and technically orientated. Berry’s work is singled out here because the contemporary practice of the Central School tradition is the generic tradition of South African English theatre voice practice. Chapter four: Strategies and constructs are proposed in support of the centrality of voice to the theatre. Ways of realising a theatrical use of the voice are also suggested. This is based on a shift in the way in which practitioners think about theatre voice. In the first instance, it is suggested that practitioners move beyond positions of polarity and actively embrace that which is contradictory in theatre and theatre voice practice. Secondly, a traditional hermeneutic understanding of the interpretation of voice is challenged. Thirdly, the use of metaphor which is pertinent to actors, directors and voice practitioners is explored as a means to vocal action. Concrete examples of the creative use of the voice, are provided through the sonic texts of Performance Writing. By way of conclusion, some ideas are offered about the issue of empowering the actor in a theatrical use of the voice. This study is intended to contribute to a theoretical and practical debate which will promote the argument for the centrality of voice to performance.
- Full Text:
- Date Issued: 2000
The development of a geographic information systems based atlas of southern African freshwater fish, and its application to biogeographic analysis
- Scott, Lucy Elizabeth Powell
- Authors: Scott, Lucy Elizabeth Powell
- Date: 2000
- Subjects: Freshwater fishes -- Africa, Southern , Freshwater fishes -- Geographical distribution -- Atlases , Freshwater fishes -- Africa, Southern -- Geographical distribution -- Atlases , Geographic information systems
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5256 , http://hdl.handle.net/10962/d1005099 , Freshwater fishes -- Africa, Southern , Freshwater fishes -- Geographical distribution -- Atlases , Freshwater fishes -- Africa, Southern -- Geographical distribution -- Atlases , Geographic information systems
- Description: A Geographic Information Systems (GIS) atlas of southern African freshwater fish was developed for the SADC countries from natural history collection specimens, hydrological, topographical and climatological data. The primary purpose of the development of the atlas of freshwater fish was the construction of a practical framework to transform vast amounts of existing biological data for use in research and management of aquatic resources. The database of freshwater fish collection specimens that was incorporated into the atlas, was developed in association with ALCOM (Aquatic Resources Management for Local Community Development Programme). The development of advanced computing and GIS technology has increased the scope of biological atlas projects by facilitating the integration of large amounts of spatial data to produce derived databases for specific applications. The atlas of freshwater fish was constructed using TNTmips GIS software as the most practical system available for managing and analysing biological data with a spatial component. The atlas contains 35 180 comprehensive distribution records of 735 species of fish. It has many applications as an inventory of ichthyofaunal spatial biodiversity, including those of conservation planning, environmental assessment and biogeographic research. Biogeographic studies have traditionally been subjective due to the logistical problems of working with large amounts of distribution data, although some small-scale quantitative research has been carried out in the past. The content of the atlas of freshwater fish is tested with respect to these previous studies, on known patterns of freshwater fish distributions, and the analytical capability of the atlas is tested and demonstrated with some new preliminary approaches to the analysis of freshwater fish distributions in southern Africa.
- Full Text:
- Date Issued: 2000
- Authors: Scott, Lucy Elizabeth Powell
- Date: 2000
- Subjects: Freshwater fishes -- Africa, Southern , Freshwater fishes -- Geographical distribution -- Atlases , Freshwater fishes -- Africa, Southern -- Geographical distribution -- Atlases , Geographic information systems
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5256 , http://hdl.handle.net/10962/d1005099 , Freshwater fishes -- Africa, Southern , Freshwater fishes -- Geographical distribution -- Atlases , Freshwater fishes -- Africa, Southern -- Geographical distribution -- Atlases , Geographic information systems
- Description: A Geographic Information Systems (GIS) atlas of southern African freshwater fish was developed for the SADC countries from natural history collection specimens, hydrological, topographical and climatological data. The primary purpose of the development of the atlas of freshwater fish was the construction of a practical framework to transform vast amounts of existing biological data for use in research and management of aquatic resources. The database of freshwater fish collection specimens that was incorporated into the atlas, was developed in association with ALCOM (Aquatic Resources Management for Local Community Development Programme). The development of advanced computing and GIS technology has increased the scope of biological atlas projects by facilitating the integration of large amounts of spatial data to produce derived databases for specific applications. The atlas of freshwater fish was constructed using TNTmips GIS software as the most practical system available for managing and analysing biological data with a spatial component. The atlas contains 35 180 comprehensive distribution records of 735 species of fish. It has many applications as an inventory of ichthyofaunal spatial biodiversity, including those of conservation planning, environmental assessment and biogeographic research. Biogeographic studies have traditionally been subjective due to the logistical problems of working with large amounts of distribution data, although some small-scale quantitative research has been carried out in the past. The content of the atlas of freshwater fish is tested with respect to these previous studies, on known patterns of freshwater fish distributions, and the analytical capability of the atlas is tested and demonstrated with some new preliminary approaches to the analysis of freshwater fish distributions in southern Africa.
- Full Text:
- Date Issued: 2000
Sulphide-enhanced hydrolysis of primary sewage sludge : implications for the bioremediation of sulphate-enriched wastewaters
- Whittington-Jones, Kevin John
- Authors: Whittington-Jones, Kevin John
- Date: 2000
- Subjects: Bioremediation Sewage sludge Hydrolysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3910 , http://hdl.handle.net/10962/d1003969
- Description: The potential application of sulphate reducing bacteria for the bioremediation of acid mine drainage has already been recognised, and offers significant financial advantages over conventional chemical treatment approaches. Although the technology has been demonstrated successfully on both small- and large-scale, it’s extensive implementation has been constrained by the provision of suitable and cost effective electron donor and carbon sources. Primary sewage sludge is readily available in large quantities, but the slow rate of solubilization and low yield of soluble products do not apparently favour its use for this application. A number of pre-treatment steps have been introduced in an attempt to improve the yield and rates under methanogenic conditions. However, although early work suggested that degradation of lignocellulose and proteins may be more rapid under sulphate reducing conditions, the fate of primary sewage sludge under these conditions has been ignored. It was proposed that by combining the hydrolysis of primary sewage sludge and biological sulphate reduction, in a settling sludge bed, both processes would be enhanced. The aim of this study was to test this hypothesis on laboratory- and pilot-scale, and attempt to elucidate the underlying mechanism involved. The solubilization of primary sewage sludge was enhanced in the presence of sulphate reduction in continuous laboratory-scale reactors. Particulate matter accumulated in the bed of non-sulphidogenic systems, but not in sulphidogenic ones. This was attributed to increased solubilization and the smaller average floc size in the latter. Solubilization occurred within the settling sludge bed of the reactors, and offered a possible explanation for the better performance of the multiple- over single-stage reactor. A pilot-scale Falling Sludge Bed Reactor was constructed at Grootvlei Gold Mine, Springs, South Africa, and resulted in the solubilization of more than 70% of the influent primary sewage sludge. The system was also found to be highly resilient to severe perturbations, and returned rapidly to steady-state. Flask studies revealed that the hydrolysis of both proteins and complex carbohydrates was accelerated in the presence of biological sulphate reduction or sulphide. A study of the enzymology of sludge digestion revealed that sulphate reduction had little direct effect on the activity of the hydrolytic enzymes, but that reactor design was critical in the prevention of washout of these enzymes. Finally, a descriptive model was developed to explain the enhanced hydrolysis of primary sewage sludge. The model incorporated the effect of sulphidogenesis on floc fracture and reflocculation, and likely implications for mass transfer limitations.
- Full Text:
- Date Issued: 2000
- Authors: Whittington-Jones, Kevin John
- Date: 2000
- Subjects: Bioremediation Sewage sludge Hydrolysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3910 , http://hdl.handle.net/10962/d1003969
- Description: The potential application of sulphate reducing bacteria for the bioremediation of acid mine drainage has already been recognised, and offers significant financial advantages over conventional chemical treatment approaches. Although the technology has been demonstrated successfully on both small- and large-scale, it’s extensive implementation has been constrained by the provision of suitable and cost effective electron donor and carbon sources. Primary sewage sludge is readily available in large quantities, but the slow rate of solubilization and low yield of soluble products do not apparently favour its use for this application. A number of pre-treatment steps have been introduced in an attempt to improve the yield and rates under methanogenic conditions. However, although early work suggested that degradation of lignocellulose and proteins may be more rapid under sulphate reducing conditions, the fate of primary sewage sludge under these conditions has been ignored. It was proposed that by combining the hydrolysis of primary sewage sludge and biological sulphate reduction, in a settling sludge bed, both processes would be enhanced. The aim of this study was to test this hypothesis on laboratory- and pilot-scale, and attempt to elucidate the underlying mechanism involved. The solubilization of primary sewage sludge was enhanced in the presence of sulphate reduction in continuous laboratory-scale reactors. Particulate matter accumulated in the bed of non-sulphidogenic systems, but not in sulphidogenic ones. This was attributed to increased solubilization and the smaller average floc size in the latter. Solubilization occurred within the settling sludge bed of the reactors, and offered a possible explanation for the better performance of the multiple- over single-stage reactor. A pilot-scale Falling Sludge Bed Reactor was constructed at Grootvlei Gold Mine, Springs, South Africa, and resulted in the solubilization of more than 70% of the influent primary sewage sludge. The system was also found to be highly resilient to severe perturbations, and returned rapidly to steady-state. Flask studies revealed that the hydrolysis of both proteins and complex carbohydrates was accelerated in the presence of biological sulphate reduction or sulphide. A study of the enzymology of sludge digestion revealed that sulphate reduction had little direct effect on the activity of the hydrolytic enzymes, but that reactor design was critical in the prevention of washout of these enzymes. Finally, a descriptive model was developed to explain the enhanced hydrolysis of primary sewage sludge. The model incorporated the effect of sulphidogenesis on floc fracture and reflocculation, and likely implications for mass transfer limitations.
- Full Text:
- Date Issued: 2000
Grassroots diplomacy between Lesotho and South Africa: the district liaison committees
- Moeletsi, Motheba Gwendoline
- Authors: Moeletsi, Motheba Gwendoline
- Date: 2000
- Subjects: Lesotho -- Foreign relations -- South Africa , South Africa -- Foreign relations -- Lesotho , Africa -- Foreign relations -- 1960- , Africa -- Politics and government -- 1960-
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2805 , http://hdl.handle.net/10962/d1003015 , Lesotho -- Foreign relations -- South Africa , South Africa -- Foreign relations -- Lesotho , Africa -- Foreign relations -- 1960- , Africa -- Politics and government -- 1960-
- Description: Cross-border conflicts on the African continent have increased tremendously in the post-colonial years. The widespread border conflicts on the African continent have been attributed to the arbitrariness with which Africa’s national boundaries were drawn during the colonial period. The colonial boundaries have left the doors open for perpetual conflicts among African states. This thesis proposes to investigate the prospects of grassroots diplomacy as an option of dealing with border conflicts with specific reference to the case of Lesotho/South Africa border relations. This is done by critically evaluating the role the District Liaison Committees (DLCs) have played in border relations between Lesotho and South Africa. The Lesotho and South African governments have institutionalised the resolution of border conflicts at grassroots level through the establishment of the DLCs. The DLCs consists of representatives of border communities in Lesotho and South Africa. The paper introduces a not so familiar concept of involving people at grassroots levels in the conducting of diplomacy between the two neighbouring countries. The central issue implicit in this paper is that grassroots diplomacy is succeeding in the case of Lesotho and South Africa. The DLCs have managed to reduce tension between the two countries along the borders which had existed over a long period of time, thereby, relieving the central governments of some of their duties. The thesis contents that high level conventional diplomacy is not always the answer to cross-border conflicts. The example of Lesotho and South Africa could be followed by other African countries in similar situations.
- Full Text:
- Date Issued: 2000
- Authors: Moeletsi, Motheba Gwendoline
- Date: 2000
- Subjects: Lesotho -- Foreign relations -- South Africa , South Africa -- Foreign relations -- Lesotho , Africa -- Foreign relations -- 1960- , Africa -- Politics and government -- 1960-
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2805 , http://hdl.handle.net/10962/d1003015 , Lesotho -- Foreign relations -- South Africa , South Africa -- Foreign relations -- Lesotho , Africa -- Foreign relations -- 1960- , Africa -- Politics and government -- 1960-
- Description: Cross-border conflicts on the African continent have increased tremendously in the post-colonial years. The widespread border conflicts on the African continent have been attributed to the arbitrariness with which Africa’s national boundaries were drawn during the colonial period. The colonial boundaries have left the doors open for perpetual conflicts among African states. This thesis proposes to investigate the prospects of grassroots diplomacy as an option of dealing with border conflicts with specific reference to the case of Lesotho/South Africa border relations. This is done by critically evaluating the role the District Liaison Committees (DLCs) have played in border relations between Lesotho and South Africa. The Lesotho and South African governments have institutionalised the resolution of border conflicts at grassroots level through the establishment of the DLCs. The DLCs consists of representatives of border communities in Lesotho and South Africa. The paper introduces a not so familiar concept of involving people at grassroots levels in the conducting of diplomacy between the two neighbouring countries. The central issue implicit in this paper is that grassroots diplomacy is succeeding in the case of Lesotho and South Africa. The DLCs have managed to reduce tension between the two countries along the borders which had existed over a long period of time, thereby, relieving the central governments of some of their duties. The thesis contents that high level conventional diplomacy is not always the answer to cross-border conflicts. The example of Lesotho and South Africa could be followed by other African countries in similar situations.
- Full Text:
- Date Issued: 2000
"Changing ourselves, changing others" : an analysis of the life stories of participants in a training course for volunteers within a non-governmental organisation in the Eastern Cape Province of South Africa
- Authors: Harper, Christopher Duncan
- Date: 2000
- Subjects: Non-governmental organizations -- South Africa -- Eastern Cape , Violence -- South Africa -- Eastern Cape , Abused women -- Counseling of , Women -- Crimes against -- South Africa , Volunteers
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2985 , http://hdl.handle.net/10962/d1002494 , Non-governmental organizations -- South Africa -- Eastern Cape , Violence -- South Africa -- Eastern Cape , Abused women -- Counseling of , Women -- Crimes against -- South Africa , Volunteers
- Description: Gender-based violence has been recognized as a pressing mental health problem that is prevalent within South African society. Non-governmental organizations play a major role in addressing and highlighting the issue. These organizations make use of volunteers in order to assist in meeting their goals. The modernist perspective has been the dominant investigative mode when research into volunteers has been conducted. However, this study has been conducted with an emphasis on narrative. In its use of this constitutionalist and deconstructive perspective, it examines the identity of the research participants within the dominant social and cultural discourses that story their lives. This presents a major challenge to the modernist framework. In examining the life stories of the participants an emergent nature of identity is noted. Through the process of storying their lives and ascribing meaning to their experiences and understandings, the participants engaged in a process of constructing their identity. This research recognizes that identity is both multi-sited and multi-storied. The emphasis on personal agency enables the participants to restory their lives in the light of challenging prevailing discourses. It is in this process of challenge that they reauthor their lives and are in a position to change their own lives and the lives of others.
- Full Text:
- Date Issued: 2000
- Authors: Harper, Christopher Duncan
- Date: 2000
- Subjects: Non-governmental organizations -- South Africa -- Eastern Cape , Violence -- South Africa -- Eastern Cape , Abused women -- Counseling of , Women -- Crimes against -- South Africa , Volunteers
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2985 , http://hdl.handle.net/10962/d1002494 , Non-governmental organizations -- South Africa -- Eastern Cape , Violence -- South Africa -- Eastern Cape , Abused women -- Counseling of , Women -- Crimes against -- South Africa , Volunteers
- Description: Gender-based violence has been recognized as a pressing mental health problem that is prevalent within South African society. Non-governmental organizations play a major role in addressing and highlighting the issue. These organizations make use of volunteers in order to assist in meeting their goals. The modernist perspective has been the dominant investigative mode when research into volunteers has been conducted. However, this study has been conducted with an emphasis on narrative. In its use of this constitutionalist and deconstructive perspective, it examines the identity of the research participants within the dominant social and cultural discourses that story their lives. This presents a major challenge to the modernist framework. In examining the life stories of the participants an emergent nature of identity is noted. Through the process of storying their lives and ascribing meaning to their experiences and understandings, the participants engaged in a process of constructing their identity. This research recognizes that identity is both multi-sited and multi-storied. The emphasis on personal agency enables the participants to restory their lives in the light of challenging prevailing discourses. It is in this process of challenge that they reauthor their lives and are in a position to change their own lives and the lives of others.
- Full Text:
- Date Issued: 2000
The scrum-down on brain damage effects of cumulative mild head injury in rugby: a comparison of group mean scores between national rugby players and non-contact sport controls
- Authors: Finkelstein, Melissa
- Date: 2000
- Subjects: Sports injuries , Head -- Wounds and injuries , Sports injuries -- Psychological aspects , Neuropsychological tests , Rugby football injuries
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:2976 , http://hdl.handle.net/10962/d1002485 , Sports injuries , Head -- Wounds and injuries , Sports injuries -- Psychological aspects , Neuropsychological tests , Rugby football injuries
- Description: The present study comprises the second phase of a larger and ongoing research study investigating the brain damage effects of cumulative mild head injury in rugby. The purpose of this study was to determine whether cumulative mild head injury sustained in the game of rugby would cause brain injury as evidenced by impaired performance on sensitive neuropsychological tests. Participants were Springbok professional rugby players (n = 26), Under 21 rugby players (n = 19), and a non-contact sport control of national hockey players (n = 21). Comparisons of performance were carried out across a spectrum of neuropsychological tests for the three rugby groups (Total Rugby, Springbok Rugby, and Under 21 Rugby) versus the performance of the non-contact sport control group (Hockey Control), as well as comparisons of performance f9r the subgroups of Rugby Forwards versus Rugby Backs. Comparisons revealed a consistent pattern of poorer performance across all rugby groups relative to the performance of the controls on tests highly sensitive to the effects of diffuse brain damage. Within rugby group comparisons (Forwards versus Backs) showed significantly poorer performance for Total Rugby Forwards and Springbok Rugby Forwards relative to the performance of the respective Total Rugby Backs and Springbok Rugby Backs on sensitive, as well as on somewhat less sensitive, neuropsychological tests. The performance of Under 21 Rugby Forwards relative to Under 21 Rugby Backs demonstrated similar trends. Brain reserve capacity theory was used as a conceptual basis for discussing the implications of these findings.
- Full Text:
- Date Issued: 2000
- Authors: Finkelstein, Melissa
- Date: 2000
- Subjects: Sports injuries , Head -- Wounds and injuries , Sports injuries -- Psychological aspects , Neuropsychological tests , Rugby football injuries
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:2976 , http://hdl.handle.net/10962/d1002485 , Sports injuries , Head -- Wounds and injuries , Sports injuries -- Psychological aspects , Neuropsychological tests , Rugby football injuries
- Description: The present study comprises the second phase of a larger and ongoing research study investigating the brain damage effects of cumulative mild head injury in rugby. The purpose of this study was to determine whether cumulative mild head injury sustained in the game of rugby would cause brain injury as evidenced by impaired performance on sensitive neuropsychological tests. Participants were Springbok professional rugby players (n = 26), Under 21 rugby players (n = 19), and a non-contact sport control of national hockey players (n = 21). Comparisons of performance were carried out across a spectrum of neuropsychological tests for the three rugby groups (Total Rugby, Springbok Rugby, and Under 21 Rugby) versus the performance of the non-contact sport control group (Hockey Control), as well as comparisons of performance f9r the subgroups of Rugby Forwards versus Rugby Backs. Comparisons revealed a consistent pattern of poorer performance across all rugby groups relative to the performance of the controls on tests highly sensitive to the effects of diffuse brain damage. Within rugby group comparisons (Forwards versus Backs) showed significantly poorer performance for Total Rugby Forwards and Springbok Rugby Forwards relative to the performance of the respective Total Rugby Backs and Springbok Rugby Backs on sensitive, as well as on somewhat less sensitive, neuropsychological tests. The performance of Under 21 Rugby Forwards relative to Under 21 Rugby Backs demonstrated similar trends. Brain reserve capacity theory was used as a conceptual basis for discussing the implications of these findings.
- Full Text:
- Date Issued: 2000
Effects of sustained elevated CO2 concentration and Nitrogen nutrition on wheat (Triticum aestivum L. cv Gamtoos)
- Authors: Kgope, Barney Stephen
- Date: 2000
- Subjects: Wheat -- Growth , Wheat -- Nutrition , Nitrogen fertilizers , Nitrogen in agriculture
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4205 , http://hdl.handle.net/10962/d1003774 , Wheat -- Growth , Wheat -- Nutrition , Nitrogen fertilizers , Nitrogen in agriculture
- Description: There is consensus that high CO2 results in enhanced growth and yield for most crop plants. However, most of these studies were carried out in the presence of adequate nutrients, which is also the case in agricultural systems (managed ecosystems). About 20% of the earth’s land mass have sufficiently low levels of nutrients to cause some kind of stress to plants. On the other hand, elevated [CO2] decreases foliar nutrient elements in plants and as a result partitioning of certain nutrient elements in plants is altered. Little data is available on the partitioning of most nutrient elements in plants, and this will definitely impact on growth and yield. To investigate this, wheat (Triticum aestivum L. c.v. Gamtoos) was grown in controlled environment cabinets at 360 and 700 µmol mol -1 CO2. The full Long-Ashton nutrient solution comprising of three-nitrogen concentrations ([N]) viz. (4,6 and 12 mM) was used to water plants everyday. The measurement of net assimilation rate (NAR), stomatal conductance (gs), transpiration rate (E), water use efficiency (WUE), foliar [N], nitrogen use efficiency (NUE) and growth parameters (total plant biomass (TPB), total plant height (TPH), leaf area (LA), shoot and root dry weight) were made 7 days after germination (7 DAG) till the onset of flowering. The increase in nitrogen supply in the order of 4, 6 and 12mM resulted in an increase in NAR, g_s_ , WUE and a decline in E under elevated [CO2]. Under elevated [CO2] NAR was observed to increase during the first two weeks reaching its maximum at 14 DAG, thereafter followed by a decline reaching its maximum at 28 DAG. This was later followed by an increase at 35 DAG onwards. Under elevated [CO2], NAR was increased significantly between the nitrogen regimes during the first (7-14 DAG) and the last two (35-42 DAG) weeks. The response of assimilation as a function of internal [CO2] (Ci), showed a decrease with age at ages 14, 28 and 35 DAG. This negatively affected the initial slope and the CO2 saturated photosynthetic rates under all treatments. This suggest that acclimation may have been as a result of both stomatal and biochemical limitations. All the photosynthetic pigment levels (chl_a_, chl_b_, chl_(a+b)_, and C_(x+c)_ ) increased with an increase in nitrogen supply from 4 to 6mM [N]. A 12mM [N] resulted in a significant decline in the photosynthetic pigment levels compared to a 6mM [N]. Chla remained higher than chlb under all treatments. Also, NAR was seen to increase and decrease concomitantly with the photosynthetic pigment levels. Foliar [N] was seen to decrease with an increase in nitrogen supply from 4 to 6 mM [N] under elevated [CO2] and the effects were adverse under the 4mM [N]. Under the 6mM N regime foliar [N] was positively correlated to NAR for elevated [CO2] grown plants. Similarly, E was positively correlated to foliar [N] under the same conditions. Elevated CO2 and increase in nitrogen supply had a pronounced effect on total plant height (TPH), total plant biomass (TPB), leaf area (LA), shoot and root dry weight and nitrogen use efficiency (NUE). The effects were more pronounced under a 6mM [N] as a result of high NUE. However, under 12mM [N] growth was not as expected as a result of lower NUE. Under all treatments shoot dry weight (SDW) was positively correlated to NUE. Anatomical studies revealed that total leaf and midrib thickness was significantly increased with an increase in nitrogen supply under elevated CO2 to support the larger leaf areas. There were no significant changes in the chloroplast ultrastructure as a result of the increase in nitrogen supply and CO2 enrichment. Starch grain surface area was seen to decline with an increase in nitrogen under both ambient and elevated CO2. Elevated CO2 and increase in nitrogen supply significantly increased total grain dry weight per plant by 47 and 46% respectively under 6 and 12mM [N]. In contrast, the increase was by about 21, 61 and 67% respectively under 4, 6 and 12mM [N] between the CO2 regimes.
- Full Text:
- Date Issued: 2000
- Authors: Kgope, Barney Stephen
- Date: 2000
- Subjects: Wheat -- Growth , Wheat -- Nutrition , Nitrogen fertilizers , Nitrogen in agriculture
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4205 , http://hdl.handle.net/10962/d1003774 , Wheat -- Growth , Wheat -- Nutrition , Nitrogen fertilizers , Nitrogen in agriculture
- Description: There is consensus that high CO2 results in enhanced growth and yield for most crop plants. However, most of these studies were carried out in the presence of adequate nutrients, which is also the case in agricultural systems (managed ecosystems). About 20% of the earth’s land mass have sufficiently low levels of nutrients to cause some kind of stress to plants. On the other hand, elevated [CO2] decreases foliar nutrient elements in plants and as a result partitioning of certain nutrient elements in plants is altered. Little data is available on the partitioning of most nutrient elements in plants, and this will definitely impact on growth and yield. To investigate this, wheat (Triticum aestivum L. c.v. Gamtoos) was grown in controlled environment cabinets at 360 and 700 µmol mol -1 CO2. The full Long-Ashton nutrient solution comprising of three-nitrogen concentrations ([N]) viz. (4,6 and 12 mM) was used to water plants everyday. The measurement of net assimilation rate (NAR), stomatal conductance (gs), transpiration rate (E), water use efficiency (WUE), foliar [N], nitrogen use efficiency (NUE) and growth parameters (total plant biomass (TPB), total plant height (TPH), leaf area (LA), shoot and root dry weight) were made 7 days after germination (7 DAG) till the onset of flowering. The increase in nitrogen supply in the order of 4, 6 and 12mM resulted in an increase in NAR, g_s_ , WUE and a decline in E under elevated [CO2]. Under elevated [CO2] NAR was observed to increase during the first two weeks reaching its maximum at 14 DAG, thereafter followed by a decline reaching its maximum at 28 DAG. This was later followed by an increase at 35 DAG onwards. Under elevated [CO2], NAR was increased significantly between the nitrogen regimes during the first (7-14 DAG) and the last two (35-42 DAG) weeks. The response of assimilation as a function of internal [CO2] (Ci), showed a decrease with age at ages 14, 28 and 35 DAG. This negatively affected the initial slope and the CO2 saturated photosynthetic rates under all treatments. This suggest that acclimation may have been as a result of both stomatal and biochemical limitations. All the photosynthetic pigment levels (chl_a_, chl_b_, chl_(a+b)_, and C_(x+c)_ ) increased with an increase in nitrogen supply from 4 to 6mM [N]. A 12mM [N] resulted in a significant decline in the photosynthetic pigment levels compared to a 6mM [N]. Chla remained higher than chlb under all treatments. Also, NAR was seen to increase and decrease concomitantly with the photosynthetic pigment levels. Foliar [N] was seen to decrease with an increase in nitrogen supply from 4 to 6 mM [N] under elevated [CO2] and the effects were adverse under the 4mM [N]. Under the 6mM N regime foliar [N] was positively correlated to NAR for elevated [CO2] grown plants. Similarly, E was positively correlated to foliar [N] under the same conditions. Elevated CO2 and increase in nitrogen supply had a pronounced effect on total plant height (TPH), total plant biomass (TPB), leaf area (LA), shoot and root dry weight and nitrogen use efficiency (NUE). The effects were more pronounced under a 6mM [N] as a result of high NUE. However, under 12mM [N] growth was not as expected as a result of lower NUE. Under all treatments shoot dry weight (SDW) was positively correlated to NUE. Anatomical studies revealed that total leaf and midrib thickness was significantly increased with an increase in nitrogen supply under elevated CO2 to support the larger leaf areas. There were no significant changes in the chloroplast ultrastructure as a result of the increase in nitrogen supply and CO2 enrichment. Starch grain surface area was seen to decline with an increase in nitrogen under both ambient and elevated CO2. Elevated CO2 and increase in nitrogen supply significantly increased total grain dry weight per plant by 47 and 46% respectively under 6 and 12mM [N]. In contrast, the increase was by about 21, 61 and 67% respectively under 4, 6 and 12mM [N] between the CO2 regimes.
- Full Text:
- Date Issued: 2000
The use of indigenous plants as food by a rural community in the Eastern Cape : an educational exploration
- Authors: Shava, Soul
- Date: 2000
- Subjects: Plants, Edible -- South Africa -- Eastern Cape Wild plants, Edible -- South Africa -- Eastern Cape Human-plant relationships -- South Africa -- Eastern Cape Endemic plants -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1813 , http://hdl.handle.net/10962/d1003699
- Description: Looking at the use of plants as food reflects how humankind has fashioned nature. There has been a significant change in production patterns from hunter-gathering through subsistence agriculture to technologically advanced commercial agriculture with a subsequent reduction in the diversity of plants used as food. A parallel trend in consumption patterns has occurred, from home-based food processing for subsistence through small- scale production to large-scale industrial processing and the commodification of food. The overall result of such trends is a narrowing of the food resource base and an increasing reliance on processed foods at the expense of traditional diets, accompanied by increasing diet-related health risks. This research is an ethnographic case study on the use of indigenous food plants by the community of Tuku A village in the Eastern Cape using interviews and observations as the main data collecting strategies. A nutritional analysis of some wild food plants was also carried out. An inventory of more than 70 food plant species was compiled, with the knowledge of such plants found among both the elderly and the youth. The incorporation of this knowledge into education systems is recommended. Of the wild food plants documented, some were non-indigenous indicating the dynamic nature of indigenous knowledge. Some wild spinach were left to grow amongst cultivated food plants, hinting at some form of ‘domestication’ in process. This observation together with the observation that wild fruit trees were selectively conserved highlights the possibility of the continued use of wild food contributing to conservation of botanical diversity. Community use of indigenous food was found to be diminishing. Stigmatisation of indigenous food plants, urbanisation, formal education, changes in lifestyle, and media were some of the factors possibly influencing this dietary shift. The community made links between diet and health, which correspond to modern scientific knowledge, with modern diet being lamented for ill health. The nutritional analysis revealed that wild food plants do contain essential dietary nutrients, an area recommended for further research.
- Full Text:
- Date Issued: 2000
- Authors: Shava, Soul
- Date: 2000
- Subjects: Plants, Edible -- South Africa -- Eastern Cape Wild plants, Edible -- South Africa -- Eastern Cape Human-plant relationships -- South Africa -- Eastern Cape Endemic plants -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1813 , http://hdl.handle.net/10962/d1003699
- Description: Looking at the use of plants as food reflects how humankind has fashioned nature. There has been a significant change in production patterns from hunter-gathering through subsistence agriculture to technologically advanced commercial agriculture with a subsequent reduction in the diversity of plants used as food. A parallel trend in consumption patterns has occurred, from home-based food processing for subsistence through small- scale production to large-scale industrial processing and the commodification of food. The overall result of such trends is a narrowing of the food resource base and an increasing reliance on processed foods at the expense of traditional diets, accompanied by increasing diet-related health risks. This research is an ethnographic case study on the use of indigenous food plants by the community of Tuku A village in the Eastern Cape using interviews and observations as the main data collecting strategies. A nutritional analysis of some wild food plants was also carried out. An inventory of more than 70 food plant species was compiled, with the knowledge of such plants found among both the elderly and the youth. The incorporation of this knowledge into education systems is recommended. Of the wild food plants documented, some were non-indigenous indicating the dynamic nature of indigenous knowledge. Some wild spinach were left to grow amongst cultivated food plants, hinting at some form of ‘domestication’ in process. This observation together with the observation that wild fruit trees were selectively conserved highlights the possibility of the continued use of wild food contributing to conservation of botanical diversity. Community use of indigenous food was found to be diminishing. Stigmatisation of indigenous food plants, urbanisation, formal education, changes in lifestyle, and media were some of the factors possibly influencing this dietary shift. The community made links between diet and health, which correspond to modern scientific knowledge, with modern diet being lamented for ill health. The nutritional analysis revealed that wild food plants do contain essential dietary nutrients, an area recommended for further research.
- Full Text:
- Date Issued: 2000
Serotonin-melatonin interactions in acetaminophen and N,N-dimethylformamide toxicity
- Anoopkumar-Dukie, Shailendra
- Authors: Anoopkumar-Dukie, Shailendra
- Date: 2000
- Subjects: Serotonin , Acetaminophen , Melatonin
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3898 , http://hdl.handle.net/10962/d1003957 , Serotonin , Acetaminophen , Melatonin
- Description: Acetaminophen and N,N-dimethylformamide (DMF) are compounds which are extremely toxic to the liver. Acetaminophen is a drug which is well known for its analgesic and antipyretic properties. However, the abuse potential of this agent as a non-narcotic analgesic in alcoholics is well known. It is also the leading cause of overdose in England. DMF toxicity results mainly from occupational exposure. At present there are no known reports of an antidote for DMF poisoning, while N-acetylcysteine, the antidote for acetaminophen poisoning, is known to produce adverse effects. The present study evaluates the potential of melatonin as an antidote for acetaminophen and DMF poisoning. This study also investigates the mechanism underlying acetaminophen addiction and abuse. Initial studies involved in vitro techniques in an attempt to remove the complexities of organ interactions. The photodegradation studies, using ultraviolet (UV) light, revealed that melatonin accelerates the rate of acetaminophen degradation in the presence of air, and reduces the rate of degradation in the presence of nitrogen. This study also revealed that melatonin is rapidly degraded in the presence of air, following UV irradiation. The effect of DMF on hydroxyl radical generation was also determined. DMF was shown to act as a free radical scavenger, rather that a generator of free radicals. The in vitro studies were followed by lipid peroxidation determination. DMF (0.4ml/kg and 0.8ml/kg) did not produce any significant increases in lipid peroxidation in the liver. Three different doses of acetaminophen (30mg/kg, 100mg/kg, and 500mg/kg) were administered to rats for seven days. Acetaminophen (500mg/kg) was shown to significantly increase (p<0.05) lipid peroxidation in the liver. Melatonin (2.5mg/kg) was not able to significantly reduce the damage. The lower doses of acetaminophen (30mg/kg and 100mg/kg) did not increase lipid peroxidation. Electron microscopy studies showed that DMF adversely affects the liver, and in particular, the endoplasmic reticulum. Co administration of melatonin (2.5mg/kg) was able to reduce the damage. Further experiments need to be performed before an accurate assessment can be made on the ability of melatonin as an antidote for DMF and acetaminophen poisoning. Several experiments were done in an attempt to uncover the biochemical mechanism underlying acetaminophen addiction and abuse. The first experiment targeted the liver enzyme tryptophan-2,3-dioxygenase (TDO). This enzyme is the major determinant of tryptophan levels in vivo. Acetaminophen administration (100mg/kg for three hours) was shown to significantly inhibit (p<0.05) the activity of TDO, indicating increased peripheral levels of tryptophan. This experiment was followed up with determination of brain serotonin and pineal melatonin. Brain serotonin was determined using the ELISA technique. Melatonin was estimated using this technique as well as with pineal organ culture. Acetaminophen administration (100mg/kg for three hours) significantly increased (p<0.05) brain serotonin levels. Using organ culture where exogenous (3H) tryptophan is metabolised to (3H) melatonin, acetaminophen (100mg/kg for three hours) was shown to significantly increase (p<0.05) pineal melatonin concentrations. However, the ELISA technique did not reveal any changes in endogenous pineal melatonin levels. The final experiment was the determination of urinary 5-hydroxyindole acetic acid (5- HIAA), the major metabolite of serotonin, following acetaminophen administration (100mg/kg for three hours). Acetaminophen was shown to significantly reduce 5-HIAA levels (p<0.05) suggesting reduced catabolism of serotonin. The findings of this study indicate that acetaminophen mimics the actions of an antidepressant. This compelling finding has important clinical implications, and needs to be examined further.
- Full Text:
- Date Issued: 2000
- Authors: Anoopkumar-Dukie, Shailendra
- Date: 2000
- Subjects: Serotonin , Acetaminophen , Melatonin
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3898 , http://hdl.handle.net/10962/d1003957 , Serotonin , Acetaminophen , Melatonin
- Description: Acetaminophen and N,N-dimethylformamide (DMF) are compounds which are extremely toxic to the liver. Acetaminophen is a drug which is well known for its analgesic and antipyretic properties. However, the abuse potential of this agent as a non-narcotic analgesic in alcoholics is well known. It is also the leading cause of overdose in England. DMF toxicity results mainly from occupational exposure. At present there are no known reports of an antidote for DMF poisoning, while N-acetylcysteine, the antidote for acetaminophen poisoning, is known to produce adverse effects. The present study evaluates the potential of melatonin as an antidote for acetaminophen and DMF poisoning. This study also investigates the mechanism underlying acetaminophen addiction and abuse. Initial studies involved in vitro techniques in an attempt to remove the complexities of organ interactions. The photodegradation studies, using ultraviolet (UV) light, revealed that melatonin accelerates the rate of acetaminophen degradation in the presence of air, and reduces the rate of degradation in the presence of nitrogen. This study also revealed that melatonin is rapidly degraded in the presence of air, following UV irradiation. The effect of DMF on hydroxyl radical generation was also determined. DMF was shown to act as a free radical scavenger, rather that a generator of free radicals. The in vitro studies were followed by lipid peroxidation determination. DMF (0.4ml/kg and 0.8ml/kg) did not produce any significant increases in lipid peroxidation in the liver. Three different doses of acetaminophen (30mg/kg, 100mg/kg, and 500mg/kg) were administered to rats for seven days. Acetaminophen (500mg/kg) was shown to significantly increase (p<0.05) lipid peroxidation in the liver. Melatonin (2.5mg/kg) was not able to significantly reduce the damage. The lower doses of acetaminophen (30mg/kg and 100mg/kg) did not increase lipid peroxidation. Electron microscopy studies showed that DMF adversely affects the liver, and in particular, the endoplasmic reticulum. Co administration of melatonin (2.5mg/kg) was able to reduce the damage. Further experiments need to be performed before an accurate assessment can be made on the ability of melatonin as an antidote for DMF and acetaminophen poisoning. Several experiments were done in an attempt to uncover the biochemical mechanism underlying acetaminophen addiction and abuse. The first experiment targeted the liver enzyme tryptophan-2,3-dioxygenase (TDO). This enzyme is the major determinant of tryptophan levels in vivo. Acetaminophen administration (100mg/kg for three hours) was shown to significantly inhibit (p<0.05) the activity of TDO, indicating increased peripheral levels of tryptophan. This experiment was followed up with determination of brain serotonin and pineal melatonin. Brain serotonin was determined using the ELISA technique. Melatonin was estimated using this technique as well as with pineal organ culture. Acetaminophen administration (100mg/kg for three hours) significantly increased (p<0.05) brain serotonin levels. Using organ culture where exogenous (3H) tryptophan is metabolised to (3H) melatonin, acetaminophen (100mg/kg for three hours) was shown to significantly increase (p<0.05) pineal melatonin concentrations. However, the ELISA technique did not reveal any changes in endogenous pineal melatonin levels. The final experiment was the determination of urinary 5-hydroxyindole acetic acid (5- HIAA), the major metabolite of serotonin, following acetaminophen administration (100mg/kg for three hours). Acetaminophen was shown to significantly reduce 5-HIAA levels (p<0.05) suggesting reduced catabolism of serotonin. The findings of this study indicate that acetaminophen mimics the actions of an antidepressant. This compelling finding has important clinical implications, and needs to be examined further.
- Full Text:
- Date Issued: 2000