Enabling reflexivity and the development of reflexive competence within course processes: a case study of an environmental education professional development course
- Authors: Raven, Glenda C
- Date: 2005
- Subjects: Rhodes University / Gold Fields Course in Environmental Education Environmental education -- Research -- South Africa Environmental education -- South Africa -- Curricula Competency-based education -- South Africa Education and state -- South Africa Education -- Research
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1507 , http://hdl.handle.net/10962/d1003389
- Description: This research was undertaken in the context of socio-economic transformation in South Africa, and more specifically, in the context of change in education policy. To support socio-economic transformation in South Africa after the first democratic elections in 1994, a competence-based National Qualifications Framework (NQF) was introduced in 1995. In responding to the particular socio-historical context of South Africa, the South African NQF is underpinned by the notion of applied competence, integrating practical, foundational and reflexive competence, which is the key and distinguishing feature of this competence-based framework. In this context of transformation, the research was aimed at an in-depth exploration of the notion of reflexivity and reflexive competence, and course processes that enable its development, with a view to providing curriculum development insights for learning programme development in the competence-based NQF, more broadly, and environmental education professional development programmes, more specifically. To enable these aims, the research was undertaken in the context of the Rhodes University / Gold Fields Participatory Course in Environmental Education (RU/GF course), as a case example of a professional development course that aims to develop critically reflexive practitioners. Within an interpretivist orientation, a multiple-embedded case study approach was used to gain insight into the relationship between course processes, reflexivity and the development of reflexive competence to clarify and provide a critical perspective on how competence develops in the context of the course. Data was collected over a period of one year using observation, interviewing and document analysis as the primary data collection techniques. Data was analysed through various phases and layers to inform data generation and the synthesising of data for further interpretation. Through the literature review undertaken within the study, various significant insights emerged around the notion of reflexivity and reflexive competence. Firstly, there appears to be a need to distinguish between reflexivity as social processes of change (social actions and interactions within social systems, structures and processes) and reflexive competence (a range of integrative elements of competence) that provides the evidence of an engagement within social processes of change. The second key insight emerging is the significance of social structure in shaping participation in reflexive processes, thus emphasising the duality of structure as both the medium for, and outcome of reflexive social actions and interactions and so challenges the deterministic conception of social structure. Further, the significance of an epistemologically framed notion of reflexivity and reflexive competence emerged, in the context of responding to the complex and uncertain quality of socio-ecological risks and in supporting change in context. Reflexivity, distinguished from processes of critical reflection, foregrounds a critical exploration of both knowledge and unawareness. As such a reinterpretation of reflexive competence is offered as a process of potential challenge to dominant and reigning forms of reasoning (knowledge frameworks) and consequent principles of ordering. Through this reframing of reflexive competence, the potential exists to destabilise dominant forms of reasoning and principles of ordering to create a broader scope of possibilities for action and change in context. This reframing of reflexive competence in the context of transformation in South Africa has critical implications for engaging within processes of learning programme design in the NQF to support an engagement within reflexive processes of change and the development of a range of integrative elements of reflexive competence. In this light, the study attempts to make the following contribution to curriculum deliberations within the context of environmental education and the NQF in relation to reflexivity, reflexive competence and change: ♦ Reflexivity is conceptualised as social processes of change with reflexive competence providing evidence of engagement within these social processes of change; ♦ An epistemologically framed conception of reflexivity and reflexive competence recognises how rules of reason and the ordering of the ‘reasonable’ person come to shape social life; and so ♦ Change is conceptualised as ruptures and breaks in dominant knowledge frames and the power relations embedded in these; ♦ Unawareness emerges as a key dimension within reflexive environmental education processes in responding to the unpredictable and uncertain nature of risks; ♦ An epistemological framing of reflexivity and reflexive competence highlights the need to develop open processes of learning to support the critical exploration of knowledge and unawareness; and ♦ Within this framing of reflexivity and reflexive competence, the difficulty emerges in specifically predefining reflexive competence to inform standard setting processes within a context of intended change. In framing data within this emerging conception of reflexivity and reflexive competence, a review of course processes highlighted potential areas for reorienting the RU/GF course to support change in context, for which I make specific recommendations. Drawing on the review of course processes in the RU/GF course, and in light of the reframing of reflexivity and reflexive competence, I further offer summative discussions as ‘possible implications’ for learning programme design in the South African competence-based NQF, broadly and environmental education professional development programmes in this framework, more specifically.
- Full Text:
- Authors: Raven, Glenda C
- Date: 2005
- Subjects: Rhodes University / Gold Fields Course in Environmental Education Environmental education -- Research -- South Africa Environmental education -- South Africa -- Curricula Competency-based education -- South Africa Education and state -- South Africa Education -- Research
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1507 , http://hdl.handle.net/10962/d1003389
- Description: This research was undertaken in the context of socio-economic transformation in South Africa, and more specifically, in the context of change in education policy. To support socio-economic transformation in South Africa after the first democratic elections in 1994, a competence-based National Qualifications Framework (NQF) was introduced in 1995. In responding to the particular socio-historical context of South Africa, the South African NQF is underpinned by the notion of applied competence, integrating practical, foundational and reflexive competence, which is the key and distinguishing feature of this competence-based framework. In this context of transformation, the research was aimed at an in-depth exploration of the notion of reflexivity and reflexive competence, and course processes that enable its development, with a view to providing curriculum development insights for learning programme development in the competence-based NQF, more broadly, and environmental education professional development programmes, more specifically. To enable these aims, the research was undertaken in the context of the Rhodes University / Gold Fields Participatory Course in Environmental Education (RU/GF course), as a case example of a professional development course that aims to develop critically reflexive practitioners. Within an interpretivist orientation, a multiple-embedded case study approach was used to gain insight into the relationship between course processes, reflexivity and the development of reflexive competence to clarify and provide a critical perspective on how competence develops in the context of the course. Data was collected over a period of one year using observation, interviewing and document analysis as the primary data collection techniques. Data was analysed through various phases and layers to inform data generation and the synthesising of data for further interpretation. Through the literature review undertaken within the study, various significant insights emerged around the notion of reflexivity and reflexive competence. Firstly, there appears to be a need to distinguish between reflexivity as social processes of change (social actions and interactions within social systems, structures and processes) and reflexive competence (a range of integrative elements of competence) that provides the evidence of an engagement within social processes of change. The second key insight emerging is the significance of social structure in shaping participation in reflexive processes, thus emphasising the duality of structure as both the medium for, and outcome of reflexive social actions and interactions and so challenges the deterministic conception of social structure. Further, the significance of an epistemologically framed notion of reflexivity and reflexive competence emerged, in the context of responding to the complex and uncertain quality of socio-ecological risks and in supporting change in context. Reflexivity, distinguished from processes of critical reflection, foregrounds a critical exploration of both knowledge and unawareness. As such a reinterpretation of reflexive competence is offered as a process of potential challenge to dominant and reigning forms of reasoning (knowledge frameworks) and consequent principles of ordering. Through this reframing of reflexive competence, the potential exists to destabilise dominant forms of reasoning and principles of ordering to create a broader scope of possibilities for action and change in context. This reframing of reflexive competence in the context of transformation in South Africa has critical implications for engaging within processes of learning programme design in the NQF to support an engagement within reflexive processes of change and the development of a range of integrative elements of reflexive competence. In this light, the study attempts to make the following contribution to curriculum deliberations within the context of environmental education and the NQF in relation to reflexivity, reflexive competence and change: ♦ Reflexivity is conceptualised as social processes of change with reflexive competence providing evidence of engagement within these social processes of change; ♦ An epistemologically framed conception of reflexivity and reflexive competence recognises how rules of reason and the ordering of the ‘reasonable’ person come to shape social life; and so ♦ Change is conceptualised as ruptures and breaks in dominant knowledge frames and the power relations embedded in these; ♦ Unawareness emerges as a key dimension within reflexive environmental education processes in responding to the unpredictable and uncertain nature of risks; ♦ An epistemological framing of reflexivity and reflexive competence highlights the need to develop open processes of learning to support the critical exploration of knowledge and unawareness; and ♦ Within this framing of reflexivity and reflexive competence, the difficulty emerges in specifically predefining reflexive competence to inform standard setting processes within a context of intended change. In framing data within this emerging conception of reflexivity and reflexive competence, a review of course processes highlighted potential areas for reorienting the RU/GF course to support change in context, for which I make specific recommendations. Drawing on the review of course processes in the RU/GF course, and in light of the reframing of reflexivity and reflexive competence, I further offer summative discussions as ‘possible implications’ for learning programme design in the South African competence-based NQF, broadly and environmental education professional development programmes in this framework, more specifically.
- Full Text:
Enzymatic recovery of rhodium(III) from aqueous solution and industrial effluent using sulphate reducing bacteria: role of a hydrogenase enzyme
- Authors: Ngwenya, Nonhlanhla
- Date: 2005
- Subjects: Enzymes , Rhodium , Enzymes -- Industrial applications , Sulfur bacteria , Hydrogenation , Hydragenase , Factory and trade waste -- Purification
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3956 , http://hdl.handle.net/10962/d1004015 , Enzymes , Rhodium , Enzymes -- Industrial applications , Sulfur bacteria , Hydrogenation , Hydragenase , Factory and trade waste -- Purification
- Description: In an attempt to overcome the high maintenance and costs associated with traditional physico-chemical methods, much work is being done on the application of enzymes for the recovery of valuable metals from solutions and industrial effluents. One of the most widely studied enzymatic metal recovery systems uses hydrogenase enzymes, particularly from sulphate reducing bacteria (SRB). While it is known that hydrogenases from SRB mediate the reductive precipitation of metals, the mechanism of enzymatic reduction, however, is not yet fully understood. The main aim of the present study was to investigate the role of a hydrogenase enzyme in the removal of rhodium from both aqueous solution and industrial effluent. A quantitative analysis of the rate of removal of rhodium(III) by a resting SRB consortium under different initial rhodium and biomass concentrations, pH, temperature, presence and absence of SRB cells and electron donor, was studied. Rhodium speciation was found to be the main factor controlling the rate of removal of rhodium from solution. SRB cells were found to have a higher affinity for anionic rhodium species, as compared to both cationic and neutral species, which become abundant when speciation equilibrium was reached. Consequently, a pH-dependant rate of rhodium removal from solution was observed. The maximum SRB uptake capacity for rhodium was found to be 66 mg rhodium per g of resting SRB biomass. Electron microscopy studies revealed a time-dependant localization and distribution of rhodium precipitates, initially intracellularly and then extracellularly, suggesting the involvement of an enzymatic reductive precipitation process. A hydrogenase enzyme capable of reducing rhodium(III) from solution was isolated and purified by PEG, DEAE-Sephacel anion exchanger and Sephadex G200 gel exclusion. A distinct protein band with a molecular weight of 62kDa was obtained when the hydrogenase containing fractions were subjected to a 10% SDS-PAGE. Characterization studies indicated that the purified hydrogenase had an optimum pH and temperature of 8 and 40°C, respectively. A maximum of 88% of the initial rhodium in solution was removed when the purified hydrogenase was incubated under hydrogen. Due to the low pH of the industrial effluent (1.31), the enzymatic reduction of rhodium by the purified hydrogenase was greatly retarded. It was apparent that industrial effluent pretreatment was necessary before the application an enzymatic treatment method. In the present study, however, it has been established that SRB are good candidates for the enzymatic recovery of rhodium from both solution and effluent.
- Full Text:
- Authors: Ngwenya, Nonhlanhla
- Date: 2005
- Subjects: Enzymes , Rhodium , Enzymes -- Industrial applications , Sulfur bacteria , Hydrogenation , Hydragenase , Factory and trade waste -- Purification
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3956 , http://hdl.handle.net/10962/d1004015 , Enzymes , Rhodium , Enzymes -- Industrial applications , Sulfur bacteria , Hydrogenation , Hydragenase , Factory and trade waste -- Purification
- Description: In an attempt to overcome the high maintenance and costs associated with traditional physico-chemical methods, much work is being done on the application of enzymes for the recovery of valuable metals from solutions and industrial effluents. One of the most widely studied enzymatic metal recovery systems uses hydrogenase enzymes, particularly from sulphate reducing bacteria (SRB). While it is known that hydrogenases from SRB mediate the reductive precipitation of metals, the mechanism of enzymatic reduction, however, is not yet fully understood. The main aim of the present study was to investigate the role of a hydrogenase enzyme in the removal of rhodium from both aqueous solution and industrial effluent. A quantitative analysis of the rate of removal of rhodium(III) by a resting SRB consortium under different initial rhodium and biomass concentrations, pH, temperature, presence and absence of SRB cells and electron donor, was studied. Rhodium speciation was found to be the main factor controlling the rate of removal of rhodium from solution. SRB cells were found to have a higher affinity for anionic rhodium species, as compared to both cationic and neutral species, which become abundant when speciation equilibrium was reached. Consequently, a pH-dependant rate of rhodium removal from solution was observed. The maximum SRB uptake capacity for rhodium was found to be 66 mg rhodium per g of resting SRB biomass. Electron microscopy studies revealed a time-dependant localization and distribution of rhodium precipitates, initially intracellularly and then extracellularly, suggesting the involvement of an enzymatic reductive precipitation process. A hydrogenase enzyme capable of reducing rhodium(III) from solution was isolated and purified by PEG, DEAE-Sephacel anion exchanger and Sephadex G200 gel exclusion. A distinct protein band with a molecular weight of 62kDa was obtained when the hydrogenase containing fractions were subjected to a 10% SDS-PAGE. Characterization studies indicated that the purified hydrogenase had an optimum pH and temperature of 8 and 40°C, respectively. A maximum of 88% of the initial rhodium in solution was removed when the purified hydrogenase was incubated under hydrogen. Due to the low pH of the industrial effluent (1.31), the enzymatic reduction of rhodium by the purified hydrogenase was greatly retarded. It was apparent that industrial effluent pretreatment was necessary before the application an enzymatic treatment method. In the present study, however, it has been established that SRB are good candidates for the enzymatic recovery of rhodium from both solution and effluent.
- Full Text:
Establishment and impact of the sap-sucking mirid, Falconia intermedia (Distant) (Hemiptera: Miridae) on Lantana camara (Verbenaceae) varieties in the Eastern Cape Province, South Africa
- Heshula, Unathi-Nkosi Lelethu Peter
- Authors: Heshula, Unathi-Nkosi Lelethu Peter
- Date: 2005
- Subjects: Lantana camara -- South Africa -- Eastern Cape , Biological pest control agents -- South Africa -- Eastern Cape , Hemiptera -- South Africa -- Eastern Cape , Miridae -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5832 , http://hdl.handle.net/10962/d1008085
- Description: The biological control of the weedy complex Lantana camara (L.) (Verbenaceae) has been ongoing in South Africa for over 40 years. Despite this, the weed is still not under sufficient control and continues to invade new territories in the country. The biological control programme needs to be bolstered with releases of new and potentially damaging biological control agents. A promising biological control agent endemic to Central America, Falconia intermedia (Distant) (Hemiptera: Miridae), was imported into quarantine from Jamaica in 1994. This agent was released on sites in KwaZulu-Natal and Limpopo provinces of South Africa in 1999. Even though it initially established and damaged L. camara, populations died out at most of the release sites. As varietal difference and adverse climate have been cited as the reason for non-establishment and ineffective control in L. camara biocontrol programmes worldwide, this study attempts to investigate the role that these two factors play in this weed herbivore relationship. Laboratory no-choice trials were conducted to determine the varietal performance of F intermedia, among five Eastern Cape varieties of the weed from East London, Whitney Farm, Heather Glen Farm, Port Alfred and Lyndhurst Farm, and a variety from the Plant Protection Research Institute (PPRI), Pretoria. However, there were differences in performance as the adult mirids performed better on white-pink varieties from Whitney Farm and Heather Glen Farm. To test varietal preference in field conditions, field releases of F intermedia were also made at East London, Whitney Farm, Heather Glen Farm, Port Alfred and Lyndhurst Farm. Post release evaluations were conducted monthly for two years (2002 and 2003). The insect established at East London and Whitney Farm, both of which have white-pink varieties. Insect populations quickly died out at the Lyndhurst Farm and Port Alfred sites, which have dark pink varieties. It is suggested that field conditions may have resulted in poor plant quality and led indirectly to varietal preference, and to non-establishment at these two sites. With the onset of cooler weather, populations disappeared at Heather Glen Farm. This suggested that F. intermedia was suitable for release in more subtropical areas within South Africa where climatic conditions would be suitable throughout the year. The mirid performed well at Whitney Farm, resulting in significant reduction in plant growth parameters such as height and percentage cover, and increasing the cover of other flora growing beneath L. camara plants. Finally, ways to improve the efficacy of this agent are considered in an effort towards better control of L. camara in South Africa.
- Full Text:
- Authors: Heshula, Unathi-Nkosi Lelethu Peter
- Date: 2005
- Subjects: Lantana camara -- South Africa -- Eastern Cape , Biological pest control agents -- South Africa -- Eastern Cape , Hemiptera -- South Africa -- Eastern Cape , Miridae -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5832 , http://hdl.handle.net/10962/d1008085
- Description: The biological control of the weedy complex Lantana camara (L.) (Verbenaceae) has been ongoing in South Africa for over 40 years. Despite this, the weed is still not under sufficient control and continues to invade new territories in the country. The biological control programme needs to be bolstered with releases of new and potentially damaging biological control agents. A promising biological control agent endemic to Central America, Falconia intermedia (Distant) (Hemiptera: Miridae), was imported into quarantine from Jamaica in 1994. This agent was released on sites in KwaZulu-Natal and Limpopo provinces of South Africa in 1999. Even though it initially established and damaged L. camara, populations died out at most of the release sites. As varietal difference and adverse climate have been cited as the reason for non-establishment and ineffective control in L. camara biocontrol programmes worldwide, this study attempts to investigate the role that these two factors play in this weed herbivore relationship. Laboratory no-choice trials were conducted to determine the varietal performance of F intermedia, among five Eastern Cape varieties of the weed from East London, Whitney Farm, Heather Glen Farm, Port Alfred and Lyndhurst Farm, and a variety from the Plant Protection Research Institute (PPRI), Pretoria. However, there were differences in performance as the adult mirids performed better on white-pink varieties from Whitney Farm and Heather Glen Farm. To test varietal preference in field conditions, field releases of F intermedia were also made at East London, Whitney Farm, Heather Glen Farm, Port Alfred and Lyndhurst Farm. Post release evaluations were conducted monthly for two years (2002 and 2003). The insect established at East London and Whitney Farm, both of which have white-pink varieties. Insect populations quickly died out at the Lyndhurst Farm and Port Alfred sites, which have dark pink varieties. It is suggested that field conditions may have resulted in poor plant quality and led indirectly to varietal preference, and to non-establishment at these two sites. With the onset of cooler weather, populations disappeared at Heather Glen Farm. This suggested that F. intermedia was suitable for release in more subtropical areas within South Africa where climatic conditions would be suitable throughout the year. The mirid performed well at Whitney Farm, resulting in significant reduction in plant growth parameters such as height and percentage cover, and increasing the cover of other flora growing beneath L. camara plants. Finally, ways to improve the efficacy of this agent are considered in an effort towards better control of L. camara in South Africa.
- Full Text:
Euphausiid population structure and grazing in the Indian sector of the Antarctic Polar Frontal Zone, during austral autumn
- Bernard, Anthony Thomas Firth
- Authors: Bernard, Anthony Thomas Firth
- Date: 2005
- Subjects: Euphausiacea -- Antarctic Ocean , Euphausiacea -- Feeding and feeds
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5913 , http://hdl.handle.net/10962/d1015960
- Description: The trophodynamics of the numerically dominant euphausiid species within a region of high mesoscale oceanographic variability in the southwest Indian sector of the Antarctic Polar Frontal Zone (PFZ) were investigated during the austral autumns April/May) of 2004 and 2005. During the 2004 survey, sub-surface (200 m) temperature profiles indicated that an intense frontal feature, formed by the convergence of the Sub-Antarctic Front (SAF) and the Antarctic Polar Front (APF) bisected the survey area into two distinct zones, the Sub- Antarctic Zone (SAZ) and the Antarctic Zone (AAZ). Total integrated chlorophyll-a (chl-a) biomass was typical for the region (< 25 mg chl-a m⁻²), and was dominated by picophytoplankton. Total euphausiid abundance and biomass ranged from 0.1 to 3.1 ind m⁻³ and 0.1 to 8.1 mg dwt m⁻³, respectively, and did not differ significantly between the stations occupied in the SAZ and AAZ (p > 0.05). The multivariate analysis identified two interacting mechanisms controlling the distribution patterns, abundance and biomass of the various euphausiid species, namely (1) diel changes in abundance and biomass, (2) and restricted distribution patterns associated with the different water masses. Ingestion rates were determined for five euphausiid species. E. triacantha was found to have the highest daily ingestion rate ranging from 1 226.1 to 6 029.1 ng pigm ind⁻¹d⁻¹, while the lowest daily ingestion rates were observed in the juvenile Thysanoessa species (6.4 to 943.0 ng pigm ind⁻¹ d⁻¹). The total grazing impact of the selected euphausiids ranged from < 0.1 to 20.1 μg pigm m⁻²d⁻¹, corresponding to < 0.15 % of the areal chl-a biomass. The daily ration estimates of autotrophic carbon for the euphausiids suggested that phytoplankton represented a minor component in their diets, with only the sub-adult E. vallentini consuming sufficient phytoplankton to meet their daily carbon requirements. A cyclonic cold-core eddy spawned from the region of the APF located in the southwest Indian sector of the PFZ was the dominant feature during the 2005 survey. The total areal chl-a biomass throughout the region was low, ranging between 5.6 and 11.4 mg chl-a m⁻², and was significantly higher within the core of the eddy compared to the surrounding waters (p < 0.05). RMT-8 and WP-2 total euphausiid abundance and biomass estimates were high, and ranged from 0.004 to 0.36 ind m⁻³ and 0.065 to 1.21 mg dwt m⁻³, and from 0.01 to 18.2 ind m⁻³ and 0.01 to 15.7 mg dwt m⁻³, respectively. A distinct spatial pattern in the euphausiid community was evident with the Antarctic species, Euphausia frigida, E. triacantha and E. superba predominating within the core of the eddy, while the PFZ waters were characterized by the sub-Antarctic species, E. longirostris, Stylocheiron maximum, Nematoscelis megalops and Thysanoessa gregaria. The eddy edge acted as a transition zone where species from both regions co-occurred. Within the survey area the combined ingestion rate of the six numerically dominant euphausiid species ranged between 0.02 and 5.31 μg pigm m⁻²d¹, which corresponded to a loss of between < 0.001 and 0.11 % of the available chl-a biomass. E. triacantha and juvenile T. macura were identified as the dominant grazers. There was no apparent spatial pattern in the grazing activity of the euphausiids within the region of investigation. The average daily rations of the euphausiids examined were < 2 % of their body carbon. The low daily ration of the euphausiids could be ascribed to the predominance of small picophytoplankton in the region of investigation, which are too small to be grazed efficiently by larger zooplankton. The marked spatial patterns in species composition and the elevated abundance and biomass of euphausiids, suggest that the mesoscale eddies contribute to the spatial and temporal heterogeneity of the planktonic community of the PFZ and may represent important foraging regions for many of the apex predators within the region.
- Full Text:
- Authors: Bernard, Anthony Thomas Firth
- Date: 2005
- Subjects: Euphausiacea -- Antarctic Ocean , Euphausiacea -- Feeding and feeds
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5913 , http://hdl.handle.net/10962/d1015960
- Description: The trophodynamics of the numerically dominant euphausiid species within a region of high mesoscale oceanographic variability in the southwest Indian sector of the Antarctic Polar Frontal Zone (PFZ) were investigated during the austral autumns April/May) of 2004 and 2005. During the 2004 survey, sub-surface (200 m) temperature profiles indicated that an intense frontal feature, formed by the convergence of the Sub-Antarctic Front (SAF) and the Antarctic Polar Front (APF) bisected the survey area into two distinct zones, the Sub- Antarctic Zone (SAZ) and the Antarctic Zone (AAZ). Total integrated chlorophyll-a (chl-a) biomass was typical for the region (< 25 mg chl-a m⁻²), and was dominated by picophytoplankton. Total euphausiid abundance and biomass ranged from 0.1 to 3.1 ind m⁻³ and 0.1 to 8.1 mg dwt m⁻³, respectively, and did not differ significantly between the stations occupied in the SAZ and AAZ (p > 0.05). The multivariate analysis identified two interacting mechanisms controlling the distribution patterns, abundance and biomass of the various euphausiid species, namely (1) diel changes in abundance and biomass, (2) and restricted distribution patterns associated with the different water masses. Ingestion rates were determined for five euphausiid species. E. triacantha was found to have the highest daily ingestion rate ranging from 1 226.1 to 6 029.1 ng pigm ind⁻¹d⁻¹, while the lowest daily ingestion rates were observed in the juvenile Thysanoessa species (6.4 to 943.0 ng pigm ind⁻¹ d⁻¹). The total grazing impact of the selected euphausiids ranged from < 0.1 to 20.1 μg pigm m⁻²d⁻¹, corresponding to < 0.15 % of the areal chl-a biomass. The daily ration estimates of autotrophic carbon for the euphausiids suggested that phytoplankton represented a minor component in their diets, with only the sub-adult E. vallentini consuming sufficient phytoplankton to meet their daily carbon requirements. A cyclonic cold-core eddy spawned from the region of the APF located in the southwest Indian sector of the PFZ was the dominant feature during the 2005 survey. The total areal chl-a biomass throughout the region was low, ranging between 5.6 and 11.4 mg chl-a m⁻², and was significantly higher within the core of the eddy compared to the surrounding waters (p < 0.05). RMT-8 and WP-2 total euphausiid abundance and biomass estimates were high, and ranged from 0.004 to 0.36 ind m⁻³ and 0.065 to 1.21 mg dwt m⁻³, and from 0.01 to 18.2 ind m⁻³ and 0.01 to 15.7 mg dwt m⁻³, respectively. A distinct spatial pattern in the euphausiid community was evident with the Antarctic species, Euphausia frigida, E. triacantha and E. superba predominating within the core of the eddy, while the PFZ waters were characterized by the sub-Antarctic species, E. longirostris, Stylocheiron maximum, Nematoscelis megalops and Thysanoessa gregaria. The eddy edge acted as a transition zone where species from both regions co-occurred. Within the survey area the combined ingestion rate of the six numerically dominant euphausiid species ranged between 0.02 and 5.31 μg pigm m⁻²d¹, which corresponded to a loss of between < 0.001 and 0.11 % of the available chl-a biomass. E. triacantha and juvenile T. macura were identified as the dominant grazers. There was no apparent spatial pattern in the grazing activity of the euphausiids within the region of investigation. The average daily rations of the euphausiids examined were < 2 % of their body carbon. The low daily ration of the euphausiids could be ascribed to the predominance of small picophytoplankton in the region of investigation, which are too small to be grazed efficiently by larger zooplankton. The marked spatial patterns in species composition and the elevated abundance and biomass of euphausiids, suggest that the mesoscale eddies contribute to the spatial and temporal heterogeneity of the planktonic community of the PFZ and may represent important foraging regions for many of the apex predators within the region.
- Full Text:
Exploring learners' mathematical understanding through an analysis of their solution strategies
- Authors: Penlington, Thomas Helm
- Date: 2005
- Subjects: Mathematics -- Study and teaching (Elementary) Mathematics -- Problems, exercises, etc. Problem solving -- Study and teaching Reasoning Mathematical ability
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1934 , http://hdl.handle.net/10962/d1007642
- Description: The purpose of this study is to investigate various solution strategies employed by Grade 7 learners and their teachers when solving a given set of mathematical tasks. This study is oriented in an interpretive paradigm and is characterised by qualitative methods. The research, set in nine schools in the Eastern Cape, was carried out with nine learners and their mathematics teachers and was designed around two phases. The research tools consisted of a set of 12 tasks that were modelled after the Third International Mathematics and Science Study (TIMSS), and a process of clinical interviews that interrogated the solution strategies that were used in solving the 12 tasks. Aspects of grounded theory were used in the analysis of the data. The study reveals that in most tasks, learners relied heavily on procedural understanding at the expense of conceptual understanding. It also emphasises that the solution strategies adopted by learners, particularly whole number operations, were consistent with those strategies used by their teachers. Both learners and teachers favoured using the traditional, standard algorithm strategies and appeared to have learned these algorithms in isolation from concepts, failing to relate them to understanding. Another important finding was that there was evidence to suggest that some learners and teachers did employ their own constructed solution strategies. They were able to make sense of the problems and to 'mathematize' effectively and reason mathematically. An interesting outcome of the study shows that participants were more proficient in solving word problems than mathematical computations. This is in contrast to existing research on word problems, where it is shown that teachers find them difficult to teach and learners find them difficult to understand. The findings of this study also highlight issues for mathematics teachers to consider when dealing with computations and word problems involving number sense and other problem solving type problems.
- Full Text:
- Authors: Penlington, Thomas Helm
- Date: 2005
- Subjects: Mathematics -- Study and teaching (Elementary) Mathematics -- Problems, exercises, etc. Problem solving -- Study and teaching Reasoning Mathematical ability
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1934 , http://hdl.handle.net/10962/d1007642
- Description: The purpose of this study is to investigate various solution strategies employed by Grade 7 learners and their teachers when solving a given set of mathematical tasks. This study is oriented in an interpretive paradigm and is characterised by qualitative methods. The research, set in nine schools in the Eastern Cape, was carried out with nine learners and their mathematics teachers and was designed around two phases. The research tools consisted of a set of 12 tasks that were modelled after the Third International Mathematics and Science Study (TIMSS), and a process of clinical interviews that interrogated the solution strategies that were used in solving the 12 tasks. Aspects of grounded theory were used in the analysis of the data. The study reveals that in most tasks, learners relied heavily on procedural understanding at the expense of conceptual understanding. It also emphasises that the solution strategies adopted by learners, particularly whole number operations, were consistent with those strategies used by their teachers. Both learners and teachers favoured using the traditional, standard algorithm strategies and appeared to have learned these algorithms in isolation from concepts, failing to relate them to understanding. Another important finding was that there was evidence to suggest that some learners and teachers did employ their own constructed solution strategies. They were able to make sense of the problems and to 'mathematize' effectively and reason mathematically. An interesting outcome of the study shows that participants were more proficient in solving word problems than mathematical computations. This is in contrast to existing research on word problems, where it is shown that teachers find them difficult to teach and learners find them difficult to understand. The findings of this study also highlight issues for mathematics teachers to consider when dealing with computations and word problems involving number sense and other problem solving type problems.
- Full Text:
Fisheries management, fishing rights and redistribution within the commercial chokka squid fishery of South Africa
- Authors: Martin, Lindsay
- Date: 2005 , 2013-06-05
- Subjects: Fishery management -- South Africa , Squids -- South Africa , Squid fisheries -- South Africa , Fishery law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1059 , http://hdl.handle.net/10962/d1007500 , Fishery management -- South Africa , Squids -- South Africa , Squid fisheries -- South Africa , Fishery law and legislation -- South Africa
- Description: The objective of this thesis is to analyse the management and redistribution policies implemented in the South African squid industry. This is done within the broader context of fisheries policies that have been implemented within the South African fishing industry as the squid industry has developed. The study therefore has an institutional basis, which reviews the development of institutional mechanisms as they have evolved to deal fisheries management problems. These mechanisms (which can either be formal or informal) consist of committees, laws and constitutions that have developed as society has progressed. Probably the most prominent of these, in terms of current fisheries policy, is the Marine Living Resources Act (MLRA) of 1998. The broad policy prescription of the MLRA basically advocates the sustainable utilisation of marine resources while outlining the need to restructure the fishing industry to address historical imbalances and to achieve equity. It is this broad objective that this thesis applies to the squid fishery. The primary means of achieving the above objective, within the squid industry, has been through the reallocation of permit rights. These rights also provide the primary means by which effort is managed. A disruption in the rights allocation process therefore has implications for resource management as well. Permits rights can be described as a form of use right or propertY right. These rights are structured according to their operational-level characteristics, or rules. Changing these rules can thus affect the efficiency or flexibility of a rights based system. This is important because initial reallocation of rights, by the Department of Environmental Affairs and Tourism (DEAT), was based on an incomplete set of rights. This partly led to the failure of early redistribution attempts resulting in a "paper permit" market. Nevertheless, this thesis argues that redistribution attempts were based on ill-defined criteria that contributed to the failure described above. In addition to this the method through which redistribution was attempted is also questionable. This can be described as a weak redistribution strategy that did not account for all equity criteria (i.e. factors like capital ownership, employment or relative income levels). This thesis thus recommends, among other things, that an incentive based rights system be adopted and that the design of this system correctly caters of the operational-level rules mentioned above. In addition to this a strong redistribution, based on fishing capital, ownership, income and the transfer of skills, should be implemented. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Authors: Martin, Lindsay
- Date: 2005 , 2013-06-05
- Subjects: Fishery management -- South Africa , Squids -- South Africa , Squid fisheries -- South Africa , Fishery law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1059 , http://hdl.handle.net/10962/d1007500 , Fishery management -- South Africa , Squids -- South Africa , Squid fisheries -- South Africa , Fishery law and legislation -- South Africa
- Description: The objective of this thesis is to analyse the management and redistribution policies implemented in the South African squid industry. This is done within the broader context of fisheries policies that have been implemented within the South African fishing industry as the squid industry has developed. The study therefore has an institutional basis, which reviews the development of institutional mechanisms as they have evolved to deal fisheries management problems. These mechanisms (which can either be formal or informal) consist of committees, laws and constitutions that have developed as society has progressed. Probably the most prominent of these, in terms of current fisheries policy, is the Marine Living Resources Act (MLRA) of 1998. The broad policy prescription of the MLRA basically advocates the sustainable utilisation of marine resources while outlining the need to restructure the fishing industry to address historical imbalances and to achieve equity. It is this broad objective that this thesis applies to the squid fishery. The primary means of achieving the above objective, within the squid industry, has been through the reallocation of permit rights. These rights also provide the primary means by which effort is managed. A disruption in the rights allocation process therefore has implications for resource management as well. Permits rights can be described as a form of use right or propertY right. These rights are structured according to their operational-level characteristics, or rules. Changing these rules can thus affect the efficiency or flexibility of a rights based system. This is important because initial reallocation of rights, by the Department of Environmental Affairs and Tourism (DEAT), was based on an incomplete set of rights. This partly led to the failure of early redistribution attempts resulting in a "paper permit" market. Nevertheless, this thesis argues that redistribution attempts were based on ill-defined criteria that contributed to the failure described above. In addition to this the method through which redistribution was attempted is also questionable. This can be described as a weak redistribution strategy that did not account for all equity criteria (i.e. factors like capital ownership, employment or relative income levels). This thesis thus recommends, among other things, that an incentive based rights system be adopted and that the design of this system correctly caters of the operational-level rules mentioned above. In addition to this a strong redistribution, based on fishing capital, ownership, income and the transfer of skills, should be implemented. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
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Fishing rights, redistribution and policy : the South African commercial T.A.C. fisheries
- Authors: Mather, Diarmid John
- Date: 2005
- Subjects: Fisheries -- South Africa Fish trade -- South Africa Fishery law and legislation -- South Africa Fishery policy -- South Africa Fishery management -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1061 , http://hdl.handle.net/10962/d1007531
- Description: The main objective of this thesis is to provide an analysis of the economic logic behind fisheries policy and redistribution in South African. An examination of the institutional and organizational evolution reveals that South African fisheries policy followed the world trend in the movement toward quota management systems. However, it is argued that due to the peculiarities of the Apartheid political system, South Africa developed a unique and persistent structure of individual fishing rights that resulted in a transfer of power from the fisher to monopsonistic, and subsequently vertically integrated, fish processing companies. Problems, however, arose with the need to redistribute fishing rights to previously repressed racial groups. It is proposed that, within a specific form (TAC), the structure of individual fishing rights can be decomposed into four operational rules, namely, the right of participation, asset size, tradability and duration of term. Policy design is restricted to a feasible set of rules that impact on the flexibility of the system, the incentives facing private fishing companies and fishers, the efficiency of the fisheries management plan and finally the effect it has on a redistribution strategy. Within this analytical framework, South Africa's policy yields a very flexible system favourable to monopsonistic industrial organisation. However, by adding a redistribution constraint, this structure has a number of important effects. First, as new quota holders are added the information costs for effective fisheries management increase exponentially. Second, the transaction costs to private fishing companies are increased. Third, only the resource rent is redistributed (weak redistribution). Next, the micro to small vessel fisheries, the medium vessel fisheries and the large vessel fisheries are examined separately. The major aim is to determine, within the available data, the effect that a weak redistribution policy (redistribution of the resource rent), has on strong redistribution (redistribution of fishing capital and skills). The evidence definitely supports the analytical framework and suggests that fundamentally the structure of individual fishing rights, which evolved in response to a monopsonistic industrial organisation during the apartheid era in South Africa, works against strong redistribution. Also, that different fisheries face different constraints and that these should in certain instances be treated separately.
- Full Text:
- Authors: Mather, Diarmid John
- Date: 2005
- Subjects: Fisheries -- South Africa Fish trade -- South Africa Fishery law and legislation -- South Africa Fishery policy -- South Africa Fishery management -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1061 , http://hdl.handle.net/10962/d1007531
- Description: The main objective of this thesis is to provide an analysis of the economic logic behind fisheries policy and redistribution in South African. An examination of the institutional and organizational evolution reveals that South African fisheries policy followed the world trend in the movement toward quota management systems. However, it is argued that due to the peculiarities of the Apartheid political system, South Africa developed a unique and persistent structure of individual fishing rights that resulted in a transfer of power from the fisher to monopsonistic, and subsequently vertically integrated, fish processing companies. Problems, however, arose with the need to redistribute fishing rights to previously repressed racial groups. It is proposed that, within a specific form (TAC), the structure of individual fishing rights can be decomposed into four operational rules, namely, the right of participation, asset size, tradability and duration of term. Policy design is restricted to a feasible set of rules that impact on the flexibility of the system, the incentives facing private fishing companies and fishers, the efficiency of the fisheries management plan and finally the effect it has on a redistribution strategy. Within this analytical framework, South Africa's policy yields a very flexible system favourable to monopsonistic industrial organisation. However, by adding a redistribution constraint, this structure has a number of important effects. First, as new quota holders are added the information costs for effective fisheries management increase exponentially. Second, the transaction costs to private fishing companies are increased. Third, only the resource rent is redistributed (weak redistribution). Next, the micro to small vessel fisheries, the medium vessel fisheries and the large vessel fisheries are examined separately. The major aim is to determine, within the available data, the effect that a weak redistribution policy (redistribution of the resource rent), has on strong redistribution (redistribution of fishing capital and skills). The evidence definitely supports the analytical framework and suggests that fundamentally the structure of individual fishing rights, which evolved in response to a monopsonistic industrial organisation during the apartheid era in South Africa, works against strong redistribution. Also, that different fisheries face different constraints and that these should in certain instances be treated separately.
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Formulation and assessment of verapamil sustained release tablets
- Khamanga, Sandile Maswazi Malungelo
- Authors: Khamanga, Sandile Maswazi Malungelo
- Date: 2005
- Subjects: Verapamil , Tablets (Medicine) , Drugs -- Administration , Cardiovascular agents , Calcium -- Antagonists , Drugs -- Controlled release
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3869 , http://hdl.handle.net/10962/d1018236
- Description: The oral route of drug administration is most extensively used due to the obvious ease of administration. Verapamil hydrochloride is a WHO listed phenylalkylarnine, L-type calcium channel antagonist that is mainly indicated for cardiovascular disorders such as angina pectoris, supraventricular tachycardia and hypertension. Due to its relatively short half-life of approximately 4.0 hours, the formulation of a sustained-release dosage form is useful to improve patient compliance and to achieve predictable and optimized therapeutic plasma concentrations. Direct compression and wet granulation were initially used as methods for tablet manufacture. The direct compression method of manufacture produced tablets that exhibited formulation and manufacturing difficulties. Mini-tablets containing veraparnil hydrochloride were then prepared by wet granulation using Surelease® E-7-19010.and Eudragit® NE 30D as the granulating agents after which the granules were incorporated with an hydrophilic matrix material, Carbopol® 974P NF. Granule and powder blends were evaluated using the angle of repose, loose and tapped bulk density, Can's compressibility index, Hausner's ratio and drug content. Granules with good flow properties and satisfactory compressibility were used for further studies. Tablets were subjected to thickness, diameter and weight variation tests, crushing strength, tensile strength, friability and content uniformity studies. Tablets that showed acceptable pharmaco-technical properties were selected for further analysis. Drug content uniformity and dissolution release rates were determined using a validated isocratic HPLC method. Initially, USP apparatus 1 and 3 dissolution apparatus were used to determine in-vitro drug release rates from the formulations over a 22-hour period. USP apparatus 3 was finally selected as it offers the advantages of mimicking, in part, the changes in the physicochemical environment experienced by products in the gastro-intestinal tract. Differences in release rates between the test formulations and a commercially available product, Isoptin® SR were observed at different pH's using USP apparatus 1. The release of veraparnil hydrochloride from matrix tablets was pH dependent and was markedly reduced at higher pH values. This may be due, in part, to the poor solubility of veraparnil hydrochloride at these pH values and also the possible interaction of verapamil hydrochloride with anionic polymers used in these formulations. Swelling and erosion behaviour of the tablets were evaluated and differences in behaviour were observed which may be attributed to the physico-chemical characteristics of the polymers used in this study. In-vitro dissolution profiles were characterized by the difference (j1) and similarity factor (j2) and also by a new similarity factor, Sct. In addition, the mechanism of drug release from these dosage forms was mainly evaluated using the Korsmeyer-Peppas model and the kinetics of drug release assessed using other models, including Zero order, First order, Higuchi, HixsonCrowell, Weibull and the Baker-Lonsdale model. Dissolution kinetics were best described by application of the Weibull model, and the Korsmeyer-Peppas model. The release exponent, n, confirmed that drug release from these dosage forms was due to the mixed effects of diffusion and swelling and therefore, anomalous release kinetics are predominant. In conclusion, two test batches were found to be comparable to the reference product Isoptin® SR with respect to their in-vitro release profiles.
- Full Text:
- Authors: Khamanga, Sandile Maswazi Malungelo
- Date: 2005
- Subjects: Verapamil , Tablets (Medicine) , Drugs -- Administration , Cardiovascular agents , Calcium -- Antagonists , Drugs -- Controlled release
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3869 , http://hdl.handle.net/10962/d1018236
- Description: The oral route of drug administration is most extensively used due to the obvious ease of administration. Verapamil hydrochloride is a WHO listed phenylalkylarnine, L-type calcium channel antagonist that is mainly indicated for cardiovascular disorders such as angina pectoris, supraventricular tachycardia and hypertension. Due to its relatively short half-life of approximately 4.0 hours, the formulation of a sustained-release dosage form is useful to improve patient compliance and to achieve predictable and optimized therapeutic plasma concentrations. Direct compression and wet granulation were initially used as methods for tablet manufacture. The direct compression method of manufacture produced tablets that exhibited formulation and manufacturing difficulties. Mini-tablets containing veraparnil hydrochloride were then prepared by wet granulation using Surelease® E-7-19010.and Eudragit® NE 30D as the granulating agents after which the granules were incorporated with an hydrophilic matrix material, Carbopol® 974P NF. Granule and powder blends were evaluated using the angle of repose, loose and tapped bulk density, Can's compressibility index, Hausner's ratio and drug content. Granules with good flow properties and satisfactory compressibility were used for further studies. Tablets were subjected to thickness, diameter and weight variation tests, crushing strength, tensile strength, friability and content uniformity studies. Tablets that showed acceptable pharmaco-technical properties were selected for further analysis. Drug content uniformity and dissolution release rates were determined using a validated isocratic HPLC method. Initially, USP apparatus 1 and 3 dissolution apparatus were used to determine in-vitro drug release rates from the formulations over a 22-hour period. USP apparatus 3 was finally selected as it offers the advantages of mimicking, in part, the changes in the physicochemical environment experienced by products in the gastro-intestinal tract. Differences in release rates between the test formulations and a commercially available product, Isoptin® SR were observed at different pH's using USP apparatus 1. The release of veraparnil hydrochloride from matrix tablets was pH dependent and was markedly reduced at higher pH values. This may be due, in part, to the poor solubility of veraparnil hydrochloride at these pH values and also the possible interaction of verapamil hydrochloride with anionic polymers used in these formulations. Swelling and erosion behaviour of the tablets were evaluated and differences in behaviour were observed which may be attributed to the physico-chemical characteristics of the polymers used in this study. In-vitro dissolution profiles were characterized by the difference (j1) and similarity factor (j2) and also by a new similarity factor, Sct. In addition, the mechanism of drug release from these dosage forms was mainly evaluated using the Korsmeyer-Peppas model and the kinetics of drug release assessed using other models, including Zero order, First order, Higuchi, HixsonCrowell, Weibull and the Baker-Lonsdale model. Dissolution kinetics were best described by application of the Weibull model, and the Korsmeyer-Peppas model. The release exponent, n, confirmed that drug release from these dosage forms was due to the mixed effects of diffusion and swelling and therefore, anomalous release kinetics are predominant. In conclusion, two test batches were found to be comparable to the reference product Isoptin® SR with respect to their in-vitro release profiles.
- Full Text:
Fractured solidarities: labour regulation, workplace restructuring, and employment 'flexibility' in Namibia
- Authors: Klerck, Gilton
- Date: 2005
- Subjects: Industrial relations -- Namibia Labor -- Namibia Labor unions -- Namibia Organizational change -- Namibia Labor laws and legislation -- Namibia Casual labor -- Namibia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3343 , http://hdl.handle.net/10962/d1004898
- Description: A central concern of this thesis is the expansion, distribution and control of 'non-standard' employment in Namibia since independence. The employment relationship has assumed various historical forms under capitalism, each of which corresponds to a specific mode of regulation with distinct structural dynamics. An attempt is made to extend the regulation approach 'downwards' to account for the problem of order in the workplace and to place the employment relationship within its own regulatory framework. The point of departure in this study of the dynamics of labour regulation is the contradictory nature of labour's incorporation, allocation, control and reproduction within the labour market. The employment relationship is never only an economic exchange, but is also mediated through an institutional framework that connects the processes of production and social reproduction, and regulates conflicting interests inside and outside the workplace. This relationship, as critical realists have pointed out, is a product of the indeterminate intersection of several generative structures. The roots of these generative structures can be traced to three sets of social processes: the processes of production and the structuring of labour demand; the processes of social reproduction and the structuring of labour supply; and the forces of regulation. Non-standard employment is viewed as a particular social and spatio-temporal 'fix' for the various regulatory dilemmas generated by the standard employment relationship. This conception underscores the fact that a national system of labour regulation decisively shapes the conditions under which employers are able to casualise a part of their workforce. The differential experience across national boundaries suggests that analytical space needs to be provided for systems of labour market regulation which may either accentuate or moderate pressures for casualisation. Segmentation on the demand side of the labour market is explored through an analysis of the types of non-standard jobs created in different economic sectors. The various forms of employment 'flexibility' tend to vary in importance according to the specific manner in which a firm chooses to compete. Consequently, non-standard employees are distributed in a complex and uneven manner across industrial sectors and the occupational hierarchy, and face a diverse range of possibilities and liabilities that shape their levels and forms of participation in the labour market. By counteracting the homogenisation effects of labour law and collective bargaining, the mobilisation of cheap and disposable labour through non-standard employment contracts allows employers much greater discretion in constructing the wage-effort bargain. With non-standard employment, social and statutory regulation is weak or underdeveloped and hence managerial control is autocratic, with a significant contractual component. Although the changing social composition of the workforce associated with employment 'flexibility' poses serious challenges to the modes of organisation that have long served the labour movement, trade unions in Namibia and elsewhere have been slow to respond to the threats of casualisation. Of concern here, is the extent to which attempts to promote the security of existing union members is compatible with attempts to organise non-standard employees. This thesis shows that the unions have developed a complex amalgam of strategies in their efforts to regulate non-standard employment relationships.
- Full Text:
- Authors: Klerck, Gilton
- Date: 2005
- Subjects: Industrial relations -- Namibia Labor -- Namibia Labor unions -- Namibia Organizational change -- Namibia Labor laws and legislation -- Namibia Casual labor -- Namibia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3343 , http://hdl.handle.net/10962/d1004898
- Description: A central concern of this thesis is the expansion, distribution and control of 'non-standard' employment in Namibia since independence. The employment relationship has assumed various historical forms under capitalism, each of which corresponds to a specific mode of regulation with distinct structural dynamics. An attempt is made to extend the regulation approach 'downwards' to account for the problem of order in the workplace and to place the employment relationship within its own regulatory framework. The point of departure in this study of the dynamics of labour regulation is the contradictory nature of labour's incorporation, allocation, control and reproduction within the labour market. The employment relationship is never only an economic exchange, but is also mediated through an institutional framework that connects the processes of production and social reproduction, and regulates conflicting interests inside and outside the workplace. This relationship, as critical realists have pointed out, is a product of the indeterminate intersection of several generative structures. The roots of these generative structures can be traced to three sets of social processes: the processes of production and the structuring of labour demand; the processes of social reproduction and the structuring of labour supply; and the forces of regulation. Non-standard employment is viewed as a particular social and spatio-temporal 'fix' for the various regulatory dilemmas generated by the standard employment relationship. This conception underscores the fact that a national system of labour regulation decisively shapes the conditions under which employers are able to casualise a part of their workforce. The differential experience across national boundaries suggests that analytical space needs to be provided for systems of labour market regulation which may either accentuate or moderate pressures for casualisation. Segmentation on the demand side of the labour market is explored through an analysis of the types of non-standard jobs created in different economic sectors. The various forms of employment 'flexibility' tend to vary in importance according to the specific manner in which a firm chooses to compete. Consequently, non-standard employees are distributed in a complex and uneven manner across industrial sectors and the occupational hierarchy, and face a diverse range of possibilities and liabilities that shape their levels and forms of participation in the labour market. By counteracting the homogenisation effects of labour law and collective bargaining, the mobilisation of cheap and disposable labour through non-standard employment contracts allows employers much greater discretion in constructing the wage-effort bargain. With non-standard employment, social and statutory regulation is weak or underdeveloped and hence managerial control is autocratic, with a significant contractual component. Although the changing social composition of the workforce associated with employment 'flexibility' poses serious challenges to the modes of organisation that have long served the labour movement, trade unions in Namibia and elsewhere have been slow to respond to the threats of casualisation. Of concern here, is the extent to which attempts to promote the security of existing union members is compatible with attempts to organise non-standard employees. This thesis shows that the unions have developed a complex amalgam of strategies in their efforts to regulate non-standard employment relationships.
- Full Text:
Geology, structure and mineralization of the Onguati area, Karibib district, central Namibia
- Authors: Viljoen, Wayne
- Date: 2005
- Subjects: Geology -- Namibia -- Karibib , Geology, Structural -- Namibia -- Karibib , Mines and mineral resources -- Namibia -- Karibib
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4964 , http://hdl.handle.net/10962/d1005576 , Geology -- Namibia -- Karibib , Geology, Structural -- Namibia -- Karibib , Mines and mineral resources -- Namibia -- Karibib
- Description: The study area is situated in the Southern Central Zone of the intracontinental Pan-African Damara Orogen, approximately 20km NNE of Navachab Gold Mine in the Karibib district of Namibia. Mesothermal vein systems with Cu-Fe±Au mineralization are hosted by amphibolite facies calcitic and dolomitic marbles belonging to the Navachab Member of the Karibib Formation, and are best developed around the defunct Onguati Copper Mine, Brown Mountain and Western Workings areas. The Onguati study area is located in the saddle region of a moderately-to-gently inclined anticlinorium that experienced significant flattening during NNW-SSE-directed compression. The parallelogram arrangement of ENE- and NNE-trending thrusts and reverse faults that surround the Onguati study area may have developed when the direction of greatest principle subregional stress was oriented WSW-ESE. These structures define part of a Riedel shear system and later faults may have developed in the position of R and P shears respectively. Significant strain partitioning occurred between the ductile calcitic marbles which host the best developed, shear-related vein systems and the more competent dolomitic marbles. The thickness distributions of veins in the marbles of the Onguati Mine, Brown Mountain and Western Workings areas conform to a fractal or power-law distribution, The most intensely mineralized vein systems in the Onguati Mine and Western Workings calcitic marbles share similar low fractal dimensions (D-values) of 0.41 and 0.37 respectively. Veins In the calcitic and dolomitic marbles of the Brown Mountain area and in the dolomitic marbles of Western Workings have elevated D-values (>0.60) and are poorly mineralized. The low D-values «0.40) of the well mineralized vein systems reflect the higher degree of fracture connectivity. These vein systems were capable of efficiently draining and localizing large volumes of mineralizing fluids from crustal-scale structures. A metamorphic devolatization model is proposed where the entire Damaran metasedimentary and meta-volcanic package is seen as a large source area of very low concentrations of Cu, Au and other metals. Localization of deformation into crustal-scale faults and shear zones led to regional-scale hydrothermal fluid flow and focussing into the upstream fracture networks of the Onguati study area. Strong mineralization resulted when fluids encountered the reactive marble lithologies
- Full Text:
- Authors: Viljoen, Wayne
- Date: 2005
- Subjects: Geology -- Namibia -- Karibib , Geology, Structural -- Namibia -- Karibib , Mines and mineral resources -- Namibia -- Karibib
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4964 , http://hdl.handle.net/10962/d1005576 , Geology -- Namibia -- Karibib , Geology, Structural -- Namibia -- Karibib , Mines and mineral resources -- Namibia -- Karibib
- Description: The study area is situated in the Southern Central Zone of the intracontinental Pan-African Damara Orogen, approximately 20km NNE of Navachab Gold Mine in the Karibib district of Namibia. Mesothermal vein systems with Cu-Fe±Au mineralization are hosted by amphibolite facies calcitic and dolomitic marbles belonging to the Navachab Member of the Karibib Formation, and are best developed around the defunct Onguati Copper Mine, Brown Mountain and Western Workings areas. The Onguati study area is located in the saddle region of a moderately-to-gently inclined anticlinorium that experienced significant flattening during NNW-SSE-directed compression. The parallelogram arrangement of ENE- and NNE-trending thrusts and reverse faults that surround the Onguati study area may have developed when the direction of greatest principle subregional stress was oriented WSW-ESE. These structures define part of a Riedel shear system and later faults may have developed in the position of R and P shears respectively. Significant strain partitioning occurred between the ductile calcitic marbles which host the best developed, shear-related vein systems and the more competent dolomitic marbles. The thickness distributions of veins in the marbles of the Onguati Mine, Brown Mountain and Western Workings areas conform to a fractal or power-law distribution, The most intensely mineralized vein systems in the Onguati Mine and Western Workings calcitic marbles share similar low fractal dimensions (D-values) of 0.41 and 0.37 respectively. Veins In the calcitic and dolomitic marbles of the Brown Mountain area and in the dolomitic marbles of Western Workings have elevated D-values (>0.60) and are poorly mineralized. The low D-values «0.40) of the well mineralized vein systems reflect the higher degree of fracture connectivity. These vein systems were capable of efficiently draining and localizing large volumes of mineralizing fluids from crustal-scale structures. A metamorphic devolatization model is proposed where the entire Damaran metasedimentary and meta-volcanic package is seen as a large source area of very low concentrations of Cu, Au and other metals. Localization of deformation into crustal-scale faults and shear zones led to regional-scale hydrothermal fluid flow and focussing into the upstream fracture networks of the Onguati study area. Strong mineralization resulted when fluids encountered the reactive marble lithologies
- Full Text:
Growth, feeding and sex change in the sequential protandric shrimp Nauticaris marionis Bate 1888 at the Prince Edward Islands (Southern Ocean)
- Authors: Vumazonke, Lukhanyiso Unam
- Date: 2005
- Subjects: Shrimps -- Prince Edward Islands , Shrimps -- Feeding and feeds , Shrimps -- Nutrition , Shrimps -- Growth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5704 , http://hdl.handle.net/10962/d1005390 , Shrimps -- Prince Edward Islands , Shrimps -- Feeding and feeds , Shrimps -- Nutrition , Shrimps -- Growth
- Description: Demographic parameters and the general biology of the subantarctic shrimp Nauticaris marionis from the Prince Edward Islands were investigated. The carapace length is the most accurate indicator of body size and it was confirmed that N. marionis is a partially protandric hermaphrodite. Gravid females of N. marionis observed mainly in March with negligible hatching persisting until April/May. The majority of juveniles develop into males. Juveniles are characterised by an appendage on the endopodite of the first pleopod called the appendix interna or a.i.1. Juveniles that develop into males do so by growing a further appendage on the endopodite of the second pleopod. This appendage characterises males and is called the appendix masculina (or a.m.). Juveniles may develop directly into primary females through the development of an ovary and the loss of the a.i.1. The sequence differs among individuals, with some developing the ovary before losing the a.i.1 and others losing the a.i.1 first. Loss of the a.i.1 appears to be by shedding during a single moult, rather than by atrophy. Females can also develop by an alternative route as secondary females. Such animals first become males with an a.m. and then develop an ovary, thus forming an intermediate form called a tertium quid, or “third thing”. Again, there are two forms of tertium quid. Tertia quae a have the a.m. as well as the a.i.1. Tertia quae b have the a.m. in combination with an ovary but no a.i.1. Either form of tertium quid can develop into a secondary female through loss of the a.m., and in the case of the tertium quid a, loss of the a.i.1. It is unclear whether sexual differentiation occurs in the plankton or just after N. marionis settles on the benthos. The results of gut content analysis suggest that N. marionis is an opportunistic feeder, preying on a variety of prey with a preference for detritus, benthic amphipods and gastropods. Cannibalism of conspecific pleopods by large individuals of N. marionis occurred mostly in females, particularly in incubation containers. Cannibalism also occurs in males, and its occurrence depends on individual size, not gender. No diel patterns were observed in the feeding activity of N. marionis. In situ daily rations of males (carapace length <7mm) and females (>7mm) were equivalent to ≈10% and ≈5% of body dry weight, respectively. The von Bertalanffy growth curve parameters were empirically identified, by cohort analysis of data collected during 4 years, as K = 0.22239/year, L[subscript]∞ = 14.05789mm, t₀ = -0.05174, L₀ = 0.16083mm. N. marionis can survive up to seven years under natural conditions.
- Full Text:
- Authors: Vumazonke, Lukhanyiso Unam
- Date: 2005
- Subjects: Shrimps -- Prince Edward Islands , Shrimps -- Feeding and feeds , Shrimps -- Nutrition , Shrimps -- Growth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5704 , http://hdl.handle.net/10962/d1005390 , Shrimps -- Prince Edward Islands , Shrimps -- Feeding and feeds , Shrimps -- Nutrition , Shrimps -- Growth
- Description: Demographic parameters and the general biology of the subantarctic shrimp Nauticaris marionis from the Prince Edward Islands were investigated. The carapace length is the most accurate indicator of body size and it was confirmed that N. marionis is a partially protandric hermaphrodite. Gravid females of N. marionis observed mainly in March with negligible hatching persisting until April/May. The majority of juveniles develop into males. Juveniles are characterised by an appendage on the endopodite of the first pleopod called the appendix interna or a.i.1. Juveniles that develop into males do so by growing a further appendage on the endopodite of the second pleopod. This appendage characterises males and is called the appendix masculina (or a.m.). Juveniles may develop directly into primary females through the development of an ovary and the loss of the a.i.1. The sequence differs among individuals, with some developing the ovary before losing the a.i.1 and others losing the a.i.1 first. Loss of the a.i.1 appears to be by shedding during a single moult, rather than by atrophy. Females can also develop by an alternative route as secondary females. Such animals first become males with an a.m. and then develop an ovary, thus forming an intermediate form called a tertium quid, or “third thing”. Again, there are two forms of tertium quid. Tertia quae a have the a.m. as well as the a.i.1. Tertia quae b have the a.m. in combination with an ovary but no a.i.1. Either form of tertium quid can develop into a secondary female through loss of the a.m., and in the case of the tertium quid a, loss of the a.i.1. It is unclear whether sexual differentiation occurs in the plankton or just after N. marionis settles on the benthos. The results of gut content analysis suggest that N. marionis is an opportunistic feeder, preying on a variety of prey with a preference for detritus, benthic amphipods and gastropods. Cannibalism of conspecific pleopods by large individuals of N. marionis occurred mostly in females, particularly in incubation containers. Cannibalism also occurs in males, and its occurrence depends on individual size, not gender. No diel patterns were observed in the feeding activity of N. marionis. In situ daily rations of males (carapace length <7mm) and females (>7mm) were equivalent to ≈10% and ≈5% of body dry weight, respectively. The von Bertalanffy growth curve parameters were empirically identified, by cohort analysis of data collected during 4 years, as K = 0.22239/year, L[subscript]∞ = 14.05789mm, t₀ = -0.05174, L₀ = 0.16083mm. N. marionis can survive up to seven years under natural conditions.
- Full Text:
How policy discourses and contextual realities influence environmental teaching and learning processes in early childhood development: a case study of the Raglan Road child care centre
- Authors: Vallabh, Priya
- Date: 2005
- Subjects: Early childhood education -- South Africa , Health education -- South Africa , Environmental education -- Study and teaching -- South Africa , Day care centers -- South Africa , Child development
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1559 , http://hdl.handle.net/10962/d1003441 , Early childhood education -- South Africa , Health education -- South Africa , Environmental education -- Study and teaching -- South Africa , Day care centers -- South Africa , Child development
- Description: This case study considers the relationship between context, school policy and environmental teaching and learning processes at a community-based early childhood development centre in South Africa. The study recognises that educational practices in the early childhood development field are shaped by historical, cultural, economic and political realities at both local and national levels. It is from the understanding that each school is a unique composition of these shaping factors that the research was designed to consider the community-based school participating in this study. By compiling a contextual profile, this study attempts to consider dominant contextual factors affecting the school. Through the critical discourse analysis of a school policy document, this study considers local level policy, and through the literature chapter, national policy. Teacher interviews provide insight into teacher understanding of school policy in response to contextual issues, as well as providing insight into how teachers perceive their translation of policy into teaching practice. Observations of lessons in the centre provided an. opportunity to see how context and policy translated into and influenced environmental teaching and learning processes. This study looks at how environmental education is addressed in the Raglan Road Child Care Centre, and provides insight into how environmental education within the context of the school and in relation to school policy may be strengthened. It comments on the tensions and ambivalences arising from the relationships between context, policy and environmental teaching and learning processes and makes recommendations to address these ambivalences in ways that are contextually relevant. The main recommendations were designed to be practically useful for the school involved in the study and are focused around engaging the ambivalences emerging from this study to open up 'spaces' for deliberating environmental teaching and learning processes and other tensions arising out of the study at an ECD level. Recommendations included: 1) engaging with the strong development focus in school policy and the educational focus in national policy and teacher discourse; 2) deliberating the ways in which school policy and national policy respond to risk; 3) engaging with the ambivalence in the school-parent relationship; 4) the re-alignment of the explicit curriculum and broadening the contextually-based view of whole child development; and 5) engaging the ambivalence in approaches to education at the centre.
- Full Text:
- Authors: Vallabh, Priya
- Date: 2005
- Subjects: Early childhood education -- South Africa , Health education -- South Africa , Environmental education -- Study and teaching -- South Africa , Day care centers -- South Africa , Child development
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1559 , http://hdl.handle.net/10962/d1003441 , Early childhood education -- South Africa , Health education -- South Africa , Environmental education -- Study and teaching -- South Africa , Day care centers -- South Africa , Child development
- Description: This case study considers the relationship between context, school policy and environmental teaching and learning processes at a community-based early childhood development centre in South Africa. The study recognises that educational practices in the early childhood development field are shaped by historical, cultural, economic and political realities at both local and national levels. It is from the understanding that each school is a unique composition of these shaping factors that the research was designed to consider the community-based school participating in this study. By compiling a contextual profile, this study attempts to consider dominant contextual factors affecting the school. Through the critical discourse analysis of a school policy document, this study considers local level policy, and through the literature chapter, national policy. Teacher interviews provide insight into teacher understanding of school policy in response to contextual issues, as well as providing insight into how teachers perceive their translation of policy into teaching practice. Observations of lessons in the centre provided an. opportunity to see how context and policy translated into and influenced environmental teaching and learning processes. This study looks at how environmental education is addressed in the Raglan Road Child Care Centre, and provides insight into how environmental education within the context of the school and in relation to school policy may be strengthened. It comments on the tensions and ambivalences arising from the relationships between context, policy and environmental teaching and learning processes and makes recommendations to address these ambivalences in ways that are contextually relevant. The main recommendations were designed to be practically useful for the school involved in the study and are focused around engaging the ambivalences emerging from this study to open up 'spaces' for deliberating environmental teaching and learning processes and other tensions arising out of the study at an ECD level. Recommendations included: 1) engaging with the strong development focus in school policy and the educational focus in national policy and teacher discourse; 2) deliberating the ways in which school policy and national policy respond to risk; 3) engaging with the ambivalence in the school-parent relationship; 4) the re-alignment of the explicit curriculum and broadening the contextually-based view of whole child development; and 5) engaging the ambivalence in approaches to education at the centre.
- Full Text:
Identification of cis-elements and transacting factors involved in the abiotic stress responses of plants
- Authors: Maclear, Athlee
- Date: 2005 , 2013-06-10
- Subjects: Plants -- Effect of stress on , Proteins -- Analysis , Bioinformatics , DNA , Plant genetics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4074 , http://hdl.handle.net/10962/d1007236 , Plants -- Effect of stress on , Proteins -- Analysis , Bioinformatics , DNA , Plant genetics
- Description: Many stress situations limit plant growth, resulting in crop production difficulties. Population growth, limited availability and over-utilization of arable land, and intolerant crop species have resulted in tremendous strain being placed on agriculturalists to produce enough to sustain the world's population. An understanding of the principles involved in plant resistance to environmental stress will enable scientists to harness these mechanisms to create stress-tolerant crop species, thus increasing crop production, and enabling the farming of previously unproductive land. This research project uses computational and bioinformatics techniques to explore the promoter regions of genes, encoding proteins that are up- or down-regulated in response to specific abiotic stresses, with the aim of identifying common patterns in the cis-elements governing the regulation of these abiotic stress responsive genes. An initial dataset of fifty known genes encoding for proteins reported to be up- or down-regulated in response to plant stresses that result in water-deficit at the cellular level viz. drought, low temperature, and salinity, were identified, and a postgreSQL database created to store relevant information pertaining to these genes and the proteins encoded by them. The genomic DNA was obtained where possible, and the promoter and intron regions identified. The Neural Network Promoter Prediction (NNPP) software package was used to predict the transcription start signal (TSS) and the promoter searching software tool, TESS (Transcription Element Search Software) used to identify known and user-defined cis-elements within the promoter regions of these genes. Currently available promoter prediction software analysis tools are reported to predict one promoter per kilobase of DNA, whilst functional promoters are thought to only occur one in 30-40 kilobases, which indicates that a large perccntage of predictions are likely to be false positives (pedersen et. al., 1999). NNPP was chosen as it was rated as the highest performing promoter prediction software tool by Fickett and Hatzigeorgiou (1997) in a thorough review of eukaryotic promoter prediction algorithms, however results were less than promising as very few predicted TSS were identified in the area 50 bps up- and downstream of the gene start site, where biologically functional TSSs are known to occur (Reese, 2000; Fickett and Hatzigeorgiou, 1997). TESS results seemed to support the hypothesis that drought, low-temperature and high salinity plant stress response proteins have similar as-elements in their promoter regions, and suggested links to various other gene regulation mechanisms viz. gibberellin-, light-, auxin- and development-regulated gene expression, highlighting the vast complexity of plant stress response processes. Although far from conclusive, results provide a valuable basis for future comparative promoter studies that will attempt to deduce possible common transcriptional initiation of abiotic stress response genes. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Authors: Maclear, Athlee
- Date: 2005 , 2013-06-10
- Subjects: Plants -- Effect of stress on , Proteins -- Analysis , Bioinformatics , DNA , Plant genetics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4074 , http://hdl.handle.net/10962/d1007236 , Plants -- Effect of stress on , Proteins -- Analysis , Bioinformatics , DNA , Plant genetics
- Description: Many stress situations limit plant growth, resulting in crop production difficulties. Population growth, limited availability and over-utilization of arable land, and intolerant crop species have resulted in tremendous strain being placed on agriculturalists to produce enough to sustain the world's population. An understanding of the principles involved in plant resistance to environmental stress will enable scientists to harness these mechanisms to create stress-tolerant crop species, thus increasing crop production, and enabling the farming of previously unproductive land. This research project uses computational and bioinformatics techniques to explore the promoter regions of genes, encoding proteins that are up- or down-regulated in response to specific abiotic stresses, with the aim of identifying common patterns in the cis-elements governing the regulation of these abiotic stress responsive genes. An initial dataset of fifty known genes encoding for proteins reported to be up- or down-regulated in response to plant stresses that result in water-deficit at the cellular level viz. drought, low temperature, and salinity, were identified, and a postgreSQL database created to store relevant information pertaining to these genes and the proteins encoded by them. The genomic DNA was obtained where possible, and the promoter and intron regions identified. The Neural Network Promoter Prediction (NNPP) software package was used to predict the transcription start signal (TSS) and the promoter searching software tool, TESS (Transcription Element Search Software) used to identify known and user-defined cis-elements within the promoter regions of these genes. Currently available promoter prediction software analysis tools are reported to predict one promoter per kilobase of DNA, whilst functional promoters are thought to only occur one in 30-40 kilobases, which indicates that a large perccntage of predictions are likely to be false positives (pedersen et. al., 1999). NNPP was chosen as it was rated as the highest performing promoter prediction software tool by Fickett and Hatzigeorgiou (1997) in a thorough review of eukaryotic promoter prediction algorithms, however results were less than promising as very few predicted TSS were identified in the area 50 bps up- and downstream of the gene start site, where biologically functional TSSs are known to occur (Reese, 2000; Fickett and Hatzigeorgiou, 1997). TESS results seemed to support the hypothesis that drought, low-temperature and high salinity plant stress response proteins have similar as-elements in their promoter regions, and suggested links to various other gene regulation mechanisms viz. gibberellin-, light-, auxin- and development-regulated gene expression, highlighting the vast complexity of plant stress response processes. Although far from conclusive, results provide a valuable basis for future comparative promoter studies that will attempt to deduce possible common transcriptional initiation of abiotic stress response genes. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
Impacts of wildlife and cattle grazing on spider (araneae) biodiversity in a highland savanna ecosystem, in Laikipia, Central Kenya
- Authors: Warui, Charles Mwaura
- Date: 2005
- Subjects: Spiders -- Kenya Environmental monitoring -- Kenya Savanna ecology -- Kenya Biodiversity -- Kenya Species diversity -- Kenya Wildlife management -- Kenya Herbivores -- Ecology -- Kenya
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5712 , http://hdl.handle.net/10962/d1005398
- Description: Spiders were sampled at Mpala Research Centre, Laikipia, Kenya by pitfall-trapping and sweep-netting from May 2001 to July 2002, at a Kenyan Long-term Exclosure Experiment. The aim was to establish species composition, checklist and examine spider responses to disturbances caused by cattle, megaherbivores (giraffe and elephants) and mesoherbivores (other ungulates) by looking at three levels of resolution, namely the overall community, guilds and individual species. This is the first controlled replicated experimental study on the effects on invertebrates (spiders) by different land uses (access by large herbivores). A total of 10,487 individuals from 132 species belonging to 30 families were recorded. The family Salticidae had the highest number of species (24), followed by Gnaphosidae (20), Araneidae and Lycosidae (15 each), Theridiidae and Thomisidae (8 each) and Zodariidae (4). Most of the other families had fewer than 4 species. Throughout the study period, species not previously sampled emerged after rainfall peaks. Exclosure treatments affected plant cover, spider diversity and total species mainly through the effects of cattle, whose presence significantly reduced relative vegetation cover. An increase in vegetation cover significantly increased the diversity, total species and species evenness of the overall spider community (total samples data set). Megaherbivores and mesoherbivores had no effects on overall spider diversity. Relative vegetation cover explained approximately 20-30% of variation in community diversity, species richness and species evenness. At the guild level of resolution, the exclosure treatments had no significant effects on diversity, species richness and species evenness of web builders, plant wanderers and ground wanderers. Plant wanderers were significantly and positively correlated with relative vegetation cover, which explained 17% of variation in their diversity. Six individual species responded strongly and in contrasting ways to the same environmental variables, indicating that this level was more sensitive to environmental changes than guilds or the overall spider community. Spider diversity, relative vegetation cover and rainfall varied at a temporal scale of months and not at a spatial scale of hundreds of metres. Only species diversity and species richness from sweep-netting samples and total species from pitfall-trapping varied significantly at a spatial scale of hundreds of metres. Ordination analysis revealed that sweep-netting samples were a better indicator of grazing impacts than pitfalltrapping or combined samples and grouped to reflect cattle grazing, non-cattle grazing and to a small extent the control treatments. Other ordination analyses showed that only samples from sweep-netting and not from pitfall-trapping, were spatially partitioned at a scale of hundreds of metres. This study concludes that the spider fauna of black cotton soil habitats is rich and useful for environmental monitoring and that monitoring of several individual species as indicator of grazing impacts in savanna could be useful and relatively easy.
- Full Text:
- Authors: Warui, Charles Mwaura
- Date: 2005
- Subjects: Spiders -- Kenya Environmental monitoring -- Kenya Savanna ecology -- Kenya Biodiversity -- Kenya Species diversity -- Kenya Wildlife management -- Kenya Herbivores -- Ecology -- Kenya
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5712 , http://hdl.handle.net/10962/d1005398
- Description: Spiders were sampled at Mpala Research Centre, Laikipia, Kenya by pitfall-trapping and sweep-netting from May 2001 to July 2002, at a Kenyan Long-term Exclosure Experiment. The aim was to establish species composition, checklist and examine spider responses to disturbances caused by cattle, megaherbivores (giraffe and elephants) and mesoherbivores (other ungulates) by looking at three levels of resolution, namely the overall community, guilds and individual species. This is the first controlled replicated experimental study on the effects on invertebrates (spiders) by different land uses (access by large herbivores). A total of 10,487 individuals from 132 species belonging to 30 families were recorded. The family Salticidae had the highest number of species (24), followed by Gnaphosidae (20), Araneidae and Lycosidae (15 each), Theridiidae and Thomisidae (8 each) and Zodariidae (4). Most of the other families had fewer than 4 species. Throughout the study period, species not previously sampled emerged after rainfall peaks. Exclosure treatments affected plant cover, spider diversity and total species mainly through the effects of cattle, whose presence significantly reduced relative vegetation cover. An increase in vegetation cover significantly increased the diversity, total species and species evenness of the overall spider community (total samples data set). Megaherbivores and mesoherbivores had no effects on overall spider diversity. Relative vegetation cover explained approximately 20-30% of variation in community diversity, species richness and species evenness. At the guild level of resolution, the exclosure treatments had no significant effects on diversity, species richness and species evenness of web builders, plant wanderers and ground wanderers. Plant wanderers were significantly and positively correlated with relative vegetation cover, which explained 17% of variation in their diversity. Six individual species responded strongly and in contrasting ways to the same environmental variables, indicating that this level was more sensitive to environmental changes than guilds or the overall spider community. Spider diversity, relative vegetation cover and rainfall varied at a temporal scale of months and not at a spatial scale of hundreds of metres. Only species diversity and species richness from sweep-netting samples and total species from pitfall-trapping varied significantly at a spatial scale of hundreds of metres. Ordination analysis revealed that sweep-netting samples were a better indicator of grazing impacts than pitfalltrapping or combined samples and grouped to reflect cattle grazing, non-cattle grazing and to a small extent the control treatments. Other ordination analyses showed that only samples from sweep-netting and not from pitfall-trapping, were spatially partitioned at a scale of hundreds of metres. This study concludes that the spider fauna of black cotton soil habitats is rich and useful for environmental monitoring and that monitoring of several individual species as indicator of grazing impacts in savanna could be useful and relatively easy.
- Full Text:
In vitro release of ketoprofen from proprietary and extemporaneously manufactured gels
- Tettey-Amlalo, Ralph Nii Okai
- Authors: Tettey-Amlalo, Ralph Nii Okai
- Date: 2005
- Subjects: Transdermal medication , Drug delivery systems , High performance liquid chromatography , Nonsteroidal anti-inflammatory agents , Rheumatoid arthritis -- Treatment
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3797 , http://hdl.handle.net/10962/d1003275 , Transdermal medication , Drug delivery systems , High performance liquid chromatography , Nonsteroidal anti-inflammatory agents , Rheumatoid arthritis -- Treatment
- Description: Ketoprofen is a potent non-steroidal anti-inflammatory drug which is used for the treatment of rheumatoid arthritis. The oral administration of ketoprofen can cause gastric irritation and adverse renal effects. Transdermal delivery of the drug can bypass gastrointestinal disturbances and provide relatively consistent drug concentrations at the site of administration. The release of ketoprofen from proprietary gel products from three different countries was evaluated by comparing the in vitro release profiles. Twenty extemporaneously prepared ketoprofen gel formulations using Carbopol® polymers were manufactured. The effect of polymer, drug concentration, pH and solvent systems on the in vitro release of ketoprofen from these formulations were investigated. The gels were evaluated for drug content and pH. The release of the drug from all the formulations obeyed the Higuchi principle. Two static FDA approved diffusion cells, namely the modified Franz diffusion cell and the European Pharmacopoeia diffusion cell, were compared by measuring the in vitro release rate of ketoprofen from all the gel formulations through a synthetic silicone membrane. High-performance liquid chromatography and ultraviolet spectrophotometric analytical techniques were both used for the analysis of ketoprofen. The validated methods were employed for the determination of ketoprofen in the sample solutions taken from the receptor fluid. Two of the three proprietary products registered under the same manufacturing license exhibited similar results whereas the third product differed significantly. Among the variables investigated, the vehicle pH and solvent composition were found have the most significant effect on the in vitro release of ketoprofen from Carbopol® polymers. The different grades of Carbopol® polymers showed statistically significantly different release kinetics with respect to lag time. When evaluating the proprietary products, both the modified Franz diffusion cell and the European Pharmacopoeia diffusion cell were deemed adequate although higher profiles were generally obtained from the European Pharmacopoeia diffusion cells. Smoother diffusion profiles were obtained from samples analysed by high-performance liquid chromatography than by ultraviolet spectrophotometry in both diffusion cells. Sample solutions taken from Franz diffusion cells and analysed by ultraviolet spectrophotometry also produced smooth diffusion profiles. Erratic and higher diffusion profiles were observed with samples taken from the European Pharmacopoeia diffusion cell and analysed by ultraviolet spectrophotometry. The choice of diffusion cells and analytical procedure in product development must be weighed against the relatively poor reproducibility as observed with the European Pharmacopoeia diffusion cell.
- Full Text:
- Authors: Tettey-Amlalo, Ralph Nii Okai
- Date: 2005
- Subjects: Transdermal medication , Drug delivery systems , High performance liquid chromatography , Nonsteroidal anti-inflammatory agents , Rheumatoid arthritis -- Treatment
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3797 , http://hdl.handle.net/10962/d1003275 , Transdermal medication , Drug delivery systems , High performance liquid chromatography , Nonsteroidal anti-inflammatory agents , Rheumatoid arthritis -- Treatment
- Description: Ketoprofen is a potent non-steroidal anti-inflammatory drug which is used for the treatment of rheumatoid arthritis. The oral administration of ketoprofen can cause gastric irritation and adverse renal effects. Transdermal delivery of the drug can bypass gastrointestinal disturbances and provide relatively consistent drug concentrations at the site of administration. The release of ketoprofen from proprietary gel products from three different countries was evaluated by comparing the in vitro release profiles. Twenty extemporaneously prepared ketoprofen gel formulations using Carbopol® polymers were manufactured. The effect of polymer, drug concentration, pH and solvent systems on the in vitro release of ketoprofen from these formulations were investigated. The gels were evaluated for drug content and pH. The release of the drug from all the formulations obeyed the Higuchi principle. Two static FDA approved diffusion cells, namely the modified Franz diffusion cell and the European Pharmacopoeia diffusion cell, were compared by measuring the in vitro release rate of ketoprofen from all the gel formulations through a synthetic silicone membrane. High-performance liquid chromatography and ultraviolet spectrophotometric analytical techniques were both used for the analysis of ketoprofen. The validated methods were employed for the determination of ketoprofen in the sample solutions taken from the receptor fluid. Two of the three proprietary products registered under the same manufacturing license exhibited similar results whereas the third product differed significantly. Among the variables investigated, the vehicle pH and solvent composition were found have the most significant effect on the in vitro release of ketoprofen from Carbopol® polymers. The different grades of Carbopol® polymers showed statistically significantly different release kinetics with respect to lag time. When evaluating the proprietary products, both the modified Franz diffusion cell and the European Pharmacopoeia diffusion cell were deemed adequate although higher profiles were generally obtained from the European Pharmacopoeia diffusion cells. Smoother diffusion profiles were obtained from samples analysed by high-performance liquid chromatography than by ultraviolet spectrophotometry in both diffusion cells. Sample solutions taken from Franz diffusion cells and analysed by ultraviolet spectrophotometry also produced smooth diffusion profiles. Erratic and higher diffusion profiles were observed with samples taken from the European Pharmacopoeia diffusion cell and analysed by ultraviolet spectrophotometry. The choice of diffusion cells and analytical procedure in product development must be weighed against the relatively poor reproducibility as observed with the European Pharmacopoeia diffusion cell.
- Full Text:
Incorporating indigenous management in rock art sites in KwaZulu-Natal
- Authors: Ndlovu, Ndukuyakhe
- Date: 2005
- Subjects: Rock paintings -- Drakenberg Mountains , Cave paintings -- Drakensberg Mountains , San (African people) -- Art , Art, Prehistoric -- Drakensberg Mountains , Art, Prehistoric -- South Africa , Heritage tourism -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2089 , http://hdl.handle.net/10962/d1002652 , Rock paintings -- Drakenberg Mountains , Cave paintings -- Drakensberg Mountains , San (African people) -- Art , Art, Prehistoric -- Drakensberg Mountains , Art, Prehistoric -- South Africa , Heritage tourism -- South Africa
- Description: The majestic mountains of the uKhahlamba Drakensberg, formed many millennia ago were home to the Bushmen[footnote 1] or San people. They lived at these mountains for thousands of years before they were colonised by the Bantu speakers and the Europeans. Academic writings for many years have perpetuated the thinking that Bushman people were largely extinct. The dominance of this view in the academic writings was encouraged by historical evidence that Europeans and Bantu speakers hunted and killed Bushmen over the last several centuries. Researchers argue that the extermination of the Bushmen was because they were less human in the eyes of the foreigners, due to cattle raiding. There is still some element of this thinking amongst today’s academics, although research in the last decade is questioning this thinking. The question of whether descendants do exist is relevant to issues of rights of access to ancestral sacred sites, in particular rock art sites. At present, access to rock art sites is granted on qualification as an authentic fee-paying tourist (or affordability) rather than on group rights to a cultural heritage resource (cultural rights). Based on this, I argue that access to rock art sites is based on qualification rather than by right. This is largely driven by an approach that emphasises the physical conservation and financial sustainability of a site, rather than its spiritual maintenance. It has become clear that the interests in rock art by tourists and Bushman descendants are distinct from each other. Tourists have an aesthetic significance for rock art while Bushmen descendants have a spiritual significance for the paintings. Beyond any doubt, the physically based and financially driven approach has brought new challenges to today’s Bushmen descendants, whom in reaffirming their identities now have a new challenge to overcome. Not only are the rock art sites physically threatened but also they have lost much of their spiritual powers. Their fate lies in the hands of heritage officers who must determine access rights to the painted shelters. Both the National Heritage Resources Act and the KwaZulu-Natal Heritage Act acknowledge living heritage. However, the existence of this heritage is judged against the physical approach to rock art management. If the practises of descendants are perceived to be a threat to the rock art, they will not be approved. The case of the Duma is a classic example. Prior to the ritual ceremony at Game Pass Shelter, Kamberg, they were informed of the minimum standards for opening a rock art site to public and rules of how people should behave while visiting painted shelters. While it was evident that there are problems with the two approaches, the spiritual and physical approach, discussed in the thesis, it is important that solutions are identified. I do not believe that one approach on its own will be good enough, for reasons discussed in the thesis. Instead, the two approaches should be implemented together to compliment each other by identifying common grounds. I provide strategies as to how I believe that such a common ground can be reached. In addition, I provide my own analytical thinking as to how these strategies can be achieved. There is no general consensus over which term is appropriate. Both terms are considered by some academics to be derogatory or pejorative (Chennels 2003). San means vagabond and was given to the Bushmen by Khoi-Khoi people, because they considered themselves of a better social class, as they had domesticated animals and were more sedentary than Bushmen. However, according to WIMSA (Thoma 2003) the word San is derived from the Hai||om language meaning “people who gather”. It is normally written Saan but it has been accepted to write San. In 1993 the San requested to be called San when referred to as an entire group. If one refers to individual people/groups they like to be called by their language and cultural name i.e. Khwe, !Kung, !Xun, Ju|’hoansi, ‡Khomani, N|u, |’Auni, Hai||om, etc In this thesis, Bushmen is a preferred term, because it is a better-known term among the people who are central to this study. It is used without any insulting connotations attached to the term.
- Full Text:
- Authors: Ndlovu, Ndukuyakhe
- Date: 2005
- Subjects: Rock paintings -- Drakenberg Mountains , Cave paintings -- Drakensberg Mountains , San (African people) -- Art , Art, Prehistoric -- Drakensberg Mountains , Art, Prehistoric -- South Africa , Heritage tourism -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2089 , http://hdl.handle.net/10962/d1002652 , Rock paintings -- Drakenberg Mountains , Cave paintings -- Drakensberg Mountains , San (African people) -- Art , Art, Prehistoric -- Drakensberg Mountains , Art, Prehistoric -- South Africa , Heritage tourism -- South Africa
- Description: The majestic mountains of the uKhahlamba Drakensberg, formed many millennia ago were home to the Bushmen[footnote 1] or San people. They lived at these mountains for thousands of years before they were colonised by the Bantu speakers and the Europeans. Academic writings for many years have perpetuated the thinking that Bushman people were largely extinct. The dominance of this view in the academic writings was encouraged by historical evidence that Europeans and Bantu speakers hunted and killed Bushmen over the last several centuries. Researchers argue that the extermination of the Bushmen was because they were less human in the eyes of the foreigners, due to cattle raiding. There is still some element of this thinking amongst today’s academics, although research in the last decade is questioning this thinking. The question of whether descendants do exist is relevant to issues of rights of access to ancestral sacred sites, in particular rock art sites. At present, access to rock art sites is granted on qualification as an authentic fee-paying tourist (or affordability) rather than on group rights to a cultural heritage resource (cultural rights). Based on this, I argue that access to rock art sites is based on qualification rather than by right. This is largely driven by an approach that emphasises the physical conservation and financial sustainability of a site, rather than its spiritual maintenance. It has become clear that the interests in rock art by tourists and Bushman descendants are distinct from each other. Tourists have an aesthetic significance for rock art while Bushmen descendants have a spiritual significance for the paintings. Beyond any doubt, the physically based and financially driven approach has brought new challenges to today’s Bushmen descendants, whom in reaffirming their identities now have a new challenge to overcome. Not only are the rock art sites physically threatened but also they have lost much of their spiritual powers. Their fate lies in the hands of heritage officers who must determine access rights to the painted shelters. Both the National Heritage Resources Act and the KwaZulu-Natal Heritage Act acknowledge living heritage. However, the existence of this heritage is judged against the physical approach to rock art management. If the practises of descendants are perceived to be a threat to the rock art, they will not be approved. The case of the Duma is a classic example. Prior to the ritual ceremony at Game Pass Shelter, Kamberg, they were informed of the minimum standards for opening a rock art site to public and rules of how people should behave while visiting painted shelters. While it was evident that there are problems with the two approaches, the spiritual and physical approach, discussed in the thesis, it is important that solutions are identified. I do not believe that one approach on its own will be good enough, for reasons discussed in the thesis. Instead, the two approaches should be implemented together to compliment each other by identifying common grounds. I provide strategies as to how I believe that such a common ground can be reached. In addition, I provide my own analytical thinking as to how these strategies can be achieved. There is no general consensus over which term is appropriate. Both terms are considered by some academics to be derogatory or pejorative (Chennels 2003). San means vagabond and was given to the Bushmen by Khoi-Khoi people, because they considered themselves of a better social class, as they had domesticated animals and were more sedentary than Bushmen. However, according to WIMSA (Thoma 2003) the word San is derived from the Hai||om language meaning “people who gather”. It is normally written Saan but it has been accepted to write San. In 1993 the San requested to be called San when referred to as an entire group. If one refers to individual people/groups they like to be called by their language and cultural name i.e. Khwe, !Kung, !Xun, Ju|’hoansi, ‡Khomani, N|u, |’Auni, Hai||om, etc In this thesis, Bushmen is a preferred term, because it is a better-known term among the people who are central to this study. It is used without any insulting connotations attached to the term.
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Inspectors of education's perceptions of female principalship in the Rundu region of Namibia
- Authors: Kawana, Irene
- Date: 2005
- Subjects: Women school principals -- Namibia -- Rundu , Educational leadership -- Namibia -- Rundu , Sex discrimination in employment -- Namibia , School supervisors -- Namibia -- Attitudes
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:2006 , http://hdl.handle.net/10962/d1015746
- Description: While women constitute more than 51% of the population and far outnumber men in teaching positions in Namibia, very few occupy positions of leadership. Male candidates are still favoured for top positions, thereby denying women the chance to gain entrance to these positions. One of the reasons for this imbalance seems to be that, in spite of conscious political effort and legislation, women may still be perceived as less effective leaders than men. This research focused on leadership in education, in particular school principals, and explored the perceptions of female principalship held by school inspectors. Three school inspectors from the Rundu Education Region were purposefully selected and interviewed. Inspectors were selected on the grounds of their considerable influence in the selection and appointment of school principals. The study found that these inspectors favour school principals who show commitment to their work, have good interpersonal working relationships, are caring, good listeners, visionary and produce good results. The inspectors attribute female principals’ success to their traditionally perceived characteristics, such as caring leadership and ability to develop good human relations. Instead of perceiving these qualities as professionally negative (as is sometimes argued in the literature) the inspectors see them as indisputable assets to leadership. The respondents acknowledge the cultural stereotyping that may have influenced male attitudes to women in the past, but argue that good leadership is not specific to gender, but part of the qualities a person possesses, regardless of sex. This study concludes that, contrary to what has been reported in many studies, these inspectors perceive women principals as effective – equal to their male counterparts or sometimes even more effective - because they are caring, well organized and good at communicating and establishing relations with others. Though these qualities are different from the traditional masculine qualities which include independence and emotional strength, the respondents recognize and legitimize them as preferred qualities in current effective leadership practice.
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- Authors: Kawana, Irene
- Date: 2005
- Subjects: Women school principals -- Namibia -- Rundu , Educational leadership -- Namibia -- Rundu , Sex discrimination in employment -- Namibia , School supervisors -- Namibia -- Attitudes
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:2006 , http://hdl.handle.net/10962/d1015746
- Description: While women constitute more than 51% of the population and far outnumber men in teaching positions in Namibia, very few occupy positions of leadership. Male candidates are still favoured for top positions, thereby denying women the chance to gain entrance to these positions. One of the reasons for this imbalance seems to be that, in spite of conscious political effort and legislation, women may still be perceived as less effective leaders than men. This research focused on leadership in education, in particular school principals, and explored the perceptions of female principalship held by school inspectors. Three school inspectors from the Rundu Education Region were purposefully selected and interviewed. Inspectors were selected on the grounds of their considerable influence in the selection and appointment of school principals. The study found that these inspectors favour school principals who show commitment to their work, have good interpersonal working relationships, are caring, good listeners, visionary and produce good results. The inspectors attribute female principals’ success to their traditionally perceived characteristics, such as caring leadership and ability to develop good human relations. Instead of perceiving these qualities as professionally negative (as is sometimes argued in the literature) the inspectors see them as indisputable assets to leadership. The respondents acknowledge the cultural stereotyping that may have influenced male attitudes to women in the past, but argue that good leadership is not specific to gender, but part of the qualities a person possesses, regardless of sex. This study concludes that, contrary to what has been reported in many studies, these inspectors perceive women principals as effective – equal to their male counterparts or sometimes even more effective - because they are caring, well organized and good at communicating and establishing relations with others. Though these qualities are different from the traditional masculine qualities which include independence and emotional strength, the respondents recognize and legitimize them as preferred qualities in current effective leadership practice.
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Institutional change and ecosystem dynamics in the communal areas around Mt Coke State Forest, Eastern Cape, South Africa
- Authors: Cundill, Georgina
- Date: 2005
- Subjects: Biodiversity -- South Africa -- Eastern Cape , Ecosystem management -- South Africa -- Eastern Cape , Natural resources -- Management -- South Africa -- Eastern Cape , Sustainable agriculture -- South Africa -- Eastern Cape , Sustainable development -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape , Nature conservation -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:4746 , http://hdl.handle.net/10962/d1006959 , Biodiversity -- South Africa -- Eastern Cape , Ecosystem management -- South Africa -- Eastern Cape , Natural resources -- Management -- South Africa -- Eastern Cape , Sustainable agriculture -- South Africa -- Eastern Cape , Sustainable development -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape , Nature conservation -- South Africa -- Eastern Cape
- Description: Through a combination of theoretical discussion and case study analysis from two villages in the Eastern Cape Province, South Africa, this thesis explores the relationship between institutional change and ecosystem dynamics through a multi-scale approach that combines local and scientific knowledge. Several conceptual approaches were combined in this study. These included; the Resilience perspective, the Sustainable Rural Livelihoods approach, the Millennium Assessment framework and principles, and the Environmental Entitlements approach. Various participatory research techniques were employed which combined with GIS technologies, existing data sets, and historical records. Common pool resource areas are social spaces, where local values attached to resources are institutionally mediated, politically nuanced, economically interpreted and historically situated. Political driving forces at various scales have played a disproportionate role in local level institutional functioning in the case study area. In particular, inappropriate state-lead interventions into land use planning have weakened local level institutions, and have reduced the ability of the linked social-ecological system to cope with change and uncertainty. People and ecosystems become more vulnerable when driving forces such as political upheaval, economic depression and drought over-lap. However, rural people are not mere spectators in the face of these driving forces; they respond both reactively and proactively to ensure resilience to change and uncertainty. Ecosystems at Mt Coke play a key role during times of crisis in rural livelihoods. These ecosystems have undergone various short-term cyclical changes largely in response to rainfall fluctuations, and some longer-term changes linked to political events and trends that have affected management practices and local institutions over time. Orthodox ecological interpretations of ecosystem change appear to ignore four key factors identified in this study: 1) the role of institutions in shaping access to resources, 2) the demand for resources in rural livelihoods, 3) the dynamic interaction between social and natural systems, and 4) the interaction between social and natural systems across scales of analysis. The future of common pool resource management lies in the combination of local and scientific knowledge through an adaptive management approach that encourages learning and adaptation in local level institutional structures.
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- Authors: Cundill, Georgina
- Date: 2005
- Subjects: Biodiversity -- South Africa -- Eastern Cape , Ecosystem management -- South Africa -- Eastern Cape , Natural resources -- Management -- South Africa -- Eastern Cape , Sustainable agriculture -- South Africa -- Eastern Cape , Sustainable development -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape , Nature conservation -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:4746 , http://hdl.handle.net/10962/d1006959 , Biodiversity -- South Africa -- Eastern Cape , Ecosystem management -- South Africa -- Eastern Cape , Natural resources -- Management -- South Africa -- Eastern Cape , Sustainable agriculture -- South Africa -- Eastern Cape , Sustainable development -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape , Nature conservation -- South Africa -- Eastern Cape
- Description: Through a combination of theoretical discussion and case study analysis from two villages in the Eastern Cape Province, South Africa, this thesis explores the relationship between institutional change and ecosystem dynamics through a multi-scale approach that combines local and scientific knowledge. Several conceptual approaches were combined in this study. These included; the Resilience perspective, the Sustainable Rural Livelihoods approach, the Millennium Assessment framework and principles, and the Environmental Entitlements approach. Various participatory research techniques were employed which combined with GIS technologies, existing data sets, and historical records. Common pool resource areas are social spaces, where local values attached to resources are institutionally mediated, politically nuanced, economically interpreted and historically situated. Political driving forces at various scales have played a disproportionate role in local level institutional functioning in the case study area. In particular, inappropriate state-lead interventions into land use planning have weakened local level institutions, and have reduced the ability of the linked social-ecological system to cope with change and uncertainty. People and ecosystems become more vulnerable when driving forces such as political upheaval, economic depression and drought over-lap. However, rural people are not mere spectators in the face of these driving forces; they respond both reactively and proactively to ensure resilience to change and uncertainty. Ecosystems at Mt Coke play a key role during times of crisis in rural livelihoods. These ecosystems have undergone various short-term cyclical changes largely in response to rainfall fluctuations, and some longer-term changes linked to political events and trends that have affected management practices and local institutions over time. Orthodox ecological interpretations of ecosystem change appear to ignore four key factors identified in this study: 1) the role of institutions in shaping access to resources, 2) the demand for resources in rural livelihoods, 3) the dynamic interaction between social and natural systems, and 4) the interaction between social and natural systems across scales of analysis. The future of common pool resource management lies in the combination of local and scientific knowledge through an adaptive management approach that encourages learning and adaptation in local level institutional structures.
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Interest rate behaviour in a more transparent South African monetary policy environment
- Authors: Ballim, Goolam Hoosen
- Date: 2005
- Subjects: South African Reserve Bank , Monetary policy -- South Africa , Banks and banking -- South Africa , Interest rates -- South Africa , South Africa -- Economic policy , South Africa -- Economic conditions
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1034 , http://hdl.handle.net/10962/d1004462 , South African Reserve Bank , Monetary policy -- South Africa , Banks and banking -- South Africa , Interest rates -- South Africa , South Africa -- Economic policy , South Africa -- Economic conditions
- Description: South Africa introduced inflation targeting as a monetary policy framework in 2000. This marked a sizable shift in monetary policy management from the previous "eclectic" approach and the explicit focus on M3 money supply before that. The study appraises the effectiveness of monetary policy under this new dispensation. However, the analysis does not centre on inflation outcomes, which can be a measure of effectiveness because they are the overriding objective of the South African Reserve Bank in effect, it is possible to have a target-friendly inflation rate for a length of time despite monetary policy that is ambiguous and encourages unpredictability in market interest rates. However, persistent policy opaqueness can, over time, damage a favourable inflation scenario. For instance, if the public is unsure about the Reserve Bank's desired inflation target, price setting in the wage and goods markets may eventually produce an inflation outcome that is higher than the Bank may have intended. Rather, this study adjudicates the effectiveness of monetary policy within the context of policy transparency, which is an intrinsic part of the inflation targeting framework. The study looks at the extent to which monetary policy transparency has enhanced both the anticipatory nature of the market's response to policy actions and the force that policy has on all interest rates in the financial system, particularly long-term rates. These concepts are important because through the transmission mechanism of monetary policy, the more deft market participants are at anticipating future Reserve Bank policy the greater the Bank's ability to steady the economy before the actual policy event. With the aid of regression models to estimate the response of market rates to policy changes, the results show that there is significant movement in market rates in anticipation of policy action, rather than on the day of the event or the day after. Indeed, the estimates for market rates movement on the day of and even the day after the policy action are generally minute. For instance, the R157 long-term government bond yield changes by a significant 41 basis points in response to a one percentage point change in the Reserve Bank's benchmark repo rate in the period between the last policy action and the day preceding the current action. In contrast, the R157 bond yield changes by an insignificant 2 basis points on the day of the current repo rate change and about 1 basis point the day after the current change. The results point to a robust relationship between policy transparency and the market's ability to foresee rate action. If this were not the case, it is likely that there would be persistent market surprise and, hence, noticeable movement in interest rates on the day of the rate action and perhaps even the day after. Another important observation is that monetary policy impacts significantly on both short- and long-term market rates. Again, certifying the robustness of monetary policy under the inflation targeting regime
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- Authors: Ballim, Goolam Hoosen
- Date: 2005
- Subjects: South African Reserve Bank , Monetary policy -- South Africa , Banks and banking -- South Africa , Interest rates -- South Africa , South Africa -- Economic policy , South Africa -- Economic conditions
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1034 , http://hdl.handle.net/10962/d1004462 , South African Reserve Bank , Monetary policy -- South Africa , Banks and banking -- South Africa , Interest rates -- South Africa , South Africa -- Economic policy , South Africa -- Economic conditions
- Description: South Africa introduced inflation targeting as a monetary policy framework in 2000. This marked a sizable shift in monetary policy management from the previous "eclectic" approach and the explicit focus on M3 money supply before that. The study appraises the effectiveness of monetary policy under this new dispensation. However, the analysis does not centre on inflation outcomes, which can be a measure of effectiveness because they are the overriding objective of the South African Reserve Bank in effect, it is possible to have a target-friendly inflation rate for a length of time despite monetary policy that is ambiguous and encourages unpredictability in market interest rates. However, persistent policy opaqueness can, over time, damage a favourable inflation scenario. For instance, if the public is unsure about the Reserve Bank's desired inflation target, price setting in the wage and goods markets may eventually produce an inflation outcome that is higher than the Bank may have intended. Rather, this study adjudicates the effectiveness of monetary policy within the context of policy transparency, which is an intrinsic part of the inflation targeting framework. The study looks at the extent to which monetary policy transparency has enhanced both the anticipatory nature of the market's response to policy actions and the force that policy has on all interest rates in the financial system, particularly long-term rates. These concepts are important because through the transmission mechanism of monetary policy, the more deft market participants are at anticipating future Reserve Bank policy the greater the Bank's ability to steady the economy before the actual policy event. With the aid of regression models to estimate the response of market rates to policy changes, the results show that there is significant movement in market rates in anticipation of policy action, rather than on the day of the event or the day after. Indeed, the estimates for market rates movement on the day of and even the day after the policy action are generally minute. For instance, the R157 long-term government bond yield changes by a significant 41 basis points in response to a one percentage point change in the Reserve Bank's benchmark repo rate in the period between the last policy action and the day preceding the current action. In contrast, the R157 bond yield changes by an insignificant 2 basis points on the day of the current repo rate change and about 1 basis point the day after the current change. The results point to a robust relationship between policy transparency and the market's ability to foresee rate action. If this were not the case, it is likely that there would be persistent market surprise and, hence, noticeable movement in interest rates on the day of the rate action and perhaps even the day after. Another important observation is that monetary policy impacts significantly on both short- and long-term market rates. Again, certifying the robustness of monetary policy under the inflation targeting regime
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International relations and change: a Kuhnian interpretation
- Authors: Schoeman, Jacobus
- Date: 2005
- Subjects: Kuhn, Thomas S Kuhn, Thomas S -- Criticism and interpretation International relations International relations -- Philosophy Knowledge, Theory of
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2830 , http://hdl.handle.net/10962/d1003040
- Description: Using notions of change developed by Thomas Kuhn, the thesis argues that the rise of globalisation and the end of the Cold War presented the Westphalian or state-centric paradigm of international relations with a Kuhnian paradigm “crisis”. As a result, both the theory and the practice of international relations are in the midst of (what Kuhn calls) a “paradigm shift”. Emerging from this shift is (what is described in this work as) “Access World” and “Denial World” – a particular global configuration of the practice of international relations. Kuhn’s idea of “incommensurability” seems to typify the relationship between the two components of this bifurcated configuration of the international. Both intellectual risk-taking and political courage are required if the ontological struggle raging between “Access World” and “Denial World” is to be settled. This will pave the way for a new paradigm to emerge. Kuhn provides us with the insight that, to achieve this ontological breakthrough, a fundamental change in our vision of the discipline of International Relations, but also of the world of everyday international relations, is required. This entails recasting the study of International Relations as an emancipatory project and by recognising the centrality of human beings in the practice of international relations. Only if this is done, will we be able to arrive at a cosmopolitan political bargain that is appropriate for the 21st century.
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- Authors: Schoeman, Jacobus
- Date: 2005
- Subjects: Kuhn, Thomas S Kuhn, Thomas S -- Criticism and interpretation International relations International relations -- Philosophy Knowledge, Theory of
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2830 , http://hdl.handle.net/10962/d1003040
- Description: Using notions of change developed by Thomas Kuhn, the thesis argues that the rise of globalisation and the end of the Cold War presented the Westphalian or state-centric paradigm of international relations with a Kuhnian paradigm “crisis”. As a result, both the theory and the practice of international relations are in the midst of (what Kuhn calls) a “paradigm shift”. Emerging from this shift is (what is described in this work as) “Access World” and “Denial World” – a particular global configuration of the practice of international relations. Kuhn’s idea of “incommensurability” seems to typify the relationship between the two components of this bifurcated configuration of the international. Both intellectual risk-taking and political courage are required if the ontological struggle raging between “Access World” and “Denial World” is to be settled. This will pave the way for a new paradigm to emerge. Kuhn provides us with the insight that, to achieve this ontological breakthrough, a fundamental change in our vision of the discipline of International Relations, but also of the world of everyday international relations, is required. This entails recasting the study of International Relations as an emancipatory project and by recognising the centrality of human beings in the practice of international relations. Only if this is done, will we be able to arrive at a cosmopolitan political bargain that is appropriate for the 21st century.
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