A framework for price tariffs in the costing structures of South African private hospitals
- Authors: Botha, Gideon
- Date: 2020
- Subjects: Medical care, Cost of -- South Africa , Medical economics -- South Africa Medical care -- South Africa -- Cost control Cost accounting
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/50432 , vital:42167
- Description: The increase of South African health care costs can be extrapolated into the global healthcare cost challenge, with various factors contributing to this problem. One of the factors viewed as being central to the rising cost of health care is the inability of health care provider organisations to accurately measure unit costs of resources used to treat a patient for their medical condition and patient outcomes. The measurement of an accurate unit cost and patient outcomes is imperative to improving value, which is seen as an improvement in outcomes for every rand spent. The determination of price tariffs and the price tariff payment model used to onward bill the price tariff for medical services have also been identified as having a central role in improving value in health care. In order for price tariffs to improve value, they should be reflective and be based on an accurate unit cost that reflects the cost of resources used to provide efficient and effective care for a patient’s medical condition. For the price tariff payment model to improve value, it needs to reward providers for delivering superior patient outcomes at a lower cost by making price tariffs contingent on achieving specified outcomes as well as incorporating performance payments or holdbacks based on outcomes achieved. This study provides a framework for price tariffs in the costing structures of South African private hospitals. Secondary research was conducted in the form of a comprehensive literature search in order to do an interpretative analysis of the strengths and weaknesses of the various combinations of unit costing models and price tariff payment models used to determine prices in private hospitals. The literature review was followed by primary research that involved three phases, all of which used a qualitative research approach. In Phase 1, primary data were collected using unobtrusive measures that consisted of a data request first, followed by unstructured interviews with representatives of Hospital A and Hospital B to obtain an analysis of the combinations of unit costing model and price tariff payment model used for a laparoscopic appendectomy. In Phase 2, data were collected by means of an unstructured interview with a surgeon describing a laparoscopic appendectomy procedure in detail and based on this process description, the approximate costs for the various resources that were sourced from different suppliers could be calculated. The data analysis and interpretation were done in three phases, with each phase having different research objectives. The data were first coded and then interpreted. In the first primary research phase, the combinations of unit costing models and price tariff payment models used by private Hospital A and Hospital B were evaluated. In the second phase, the recommended combination of unit costing model and price tariff payment model was applied to a hypothetical example and evaluated. In the final phase, based on the outcome of the first and second research phases, a combination of unit costing model and price tariff payment model for private hospitals was recommended. The results showed that the recommended combination of unit costing and price tariff payment model namely time-driven activity-based costing with the global fee price tariff payment model was the most appropriate to determine price tariffs in private hospitals when compared to the unit costing models and price tariff payment models used by Hospital A and Hospital B for a laparoscopic appendectomy. Furthermore, the recommended combination of unit costing model and price tariff payment model was found to be usable for the determination of price tariffs in the costing structures of private hospitals. The time-driven activity-based costing model and global fee price tariff payment model should be adopted or used as guidelines for determining price tariffs in private hospitals in South Africa. Price tariffs would be more transparent as they would reflect the actual resource cost of treating the patient and the resources used and treatment provided could then be assessed against the delivery value chain that charts the principal activities involved in a patient’s care for a medical condition to ensure that patient best-practice protocols are followed. The proposed framework enables the determination of price tariffs based on an accurate unit cost reflecting the actual resources used to provide efficient and effective care and also improve value for the patient.
- Full Text:
- Date Issued: 2020
- Authors: Botha, Gideon
- Date: 2020
- Subjects: Medical care, Cost of -- South Africa , Medical economics -- South Africa Medical care -- South Africa -- Cost control Cost accounting
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/50432 , vital:42167
- Description: The increase of South African health care costs can be extrapolated into the global healthcare cost challenge, with various factors contributing to this problem. One of the factors viewed as being central to the rising cost of health care is the inability of health care provider organisations to accurately measure unit costs of resources used to treat a patient for their medical condition and patient outcomes. The measurement of an accurate unit cost and patient outcomes is imperative to improving value, which is seen as an improvement in outcomes for every rand spent. The determination of price tariffs and the price tariff payment model used to onward bill the price tariff for medical services have also been identified as having a central role in improving value in health care. In order for price tariffs to improve value, they should be reflective and be based on an accurate unit cost that reflects the cost of resources used to provide efficient and effective care for a patient’s medical condition. For the price tariff payment model to improve value, it needs to reward providers for delivering superior patient outcomes at a lower cost by making price tariffs contingent on achieving specified outcomes as well as incorporating performance payments or holdbacks based on outcomes achieved. This study provides a framework for price tariffs in the costing structures of South African private hospitals. Secondary research was conducted in the form of a comprehensive literature search in order to do an interpretative analysis of the strengths and weaknesses of the various combinations of unit costing models and price tariff payment models used to determine prices in private hospitals. The literature review was followed by primary research that involved three phases, all of which used a qualitative research approach. In Phase 1, primary data were collected using unobtrusive measures that consisted of a data request first, followed by unstructured interviews with representatives of Hospital A and Hospital B to obtain an analysis of the combinations of unit costing model and price tariff payment model used for a laparoscopic appendectomy. In Phase 2, data were collected by means of an unstructured interview with a surgeon describing a laparoscopic appendectomy procedure in detail and based on this process description, the approximate costs for the various resources that were sourced from different suppliers could be calculated. The data analysis and interpretation were done in three phases, with each phase having different research objectives. The data were first coded and then interpreted. In the first primary research phase, the combinations of unit costing models and price tariff payment models used by private Hospital A and Hospital B were evaluated. In the second phase, the recommended combination of unit costing model and price tariff payment model was applied to a hypothetical example and evaluated. In the final phase, based on the outcome of the first and second research phases, a combination of unit costing model and price tariff payment model for private hospitals was recommended. The results showed that the recommended combination of unit costing and price tariff payment model namely time-driven activity-based costing with the global fee price tariff payment model was the most appropriate to determine price tariffs in private hospitals when compared to the unit costing models and price tariff payment models used by Hospital A and Hospital B for a laparoscopic appendectomy. Furthermore, the recommended combination of unit costing model and price tariff payment model was found to be usable for the determination of price tariffs in the costing structures of private hospitals. The time-driven activity-based costing model and global fee price tariff payment model should be adopted or used as guidelines for determining price tariffs in private hospitals in South Africa. Price tariffs would be more transparent as they would reflect the actual resource cost of treating the patient and the resources used and treatment provided could then be assessed against the delivery value chain that charts the principal activities involved in a patient’s care for a medical condition to ensure that patient best-practice protocols are followed. The proposed framework enables the determination of price tariffs based on an accurate unit cost reflecting the actual resources used to provide efficient and effective care and also improve value for the patient.
- Full Text:
- Date Issued: 2020
Hate speech as a limitation to freedom of expression
- Authors: Botha, Joanna Catherine
- Date: 2016
- Subjects: Freedom of speech -- South Africa , Hate speech -- South Africa , Civil rights -- South Africa
- Language: English
- Type: Thesis , Doctoral , LLD
- Identifier: http://hdl.handle.net/10948/9054 , vital:26460
- Description: Hate speech in South Africa creates a tension between the right to freedom of expression and the rights to human dignity and equality. The challenge is to achieve a balance between these competing rights in the context of the divisive past and the transformative constitutional ideal, in which reconciliation and respect for group difference are promoted. Freedom of expression, an individual right, must be construed in light of its underlying values, but regard must also be given to communitarian interests. The constitutional standard draws the initial line. The advocacy of hatred on four grounds and which constitutes incitement to cause harm is not constitutionally protected speech. Such speech undermines nation building, causes acrimony, and is not tolerated in the egalitarian society envisaged by the Constitution. The thesis formulates a principled legislative hate speech framework for South Africa at both human rights and criminal levels within the parameters of the constitutional mandate, as guided by the standard for hate speech restrictions in international law, and the Canadian regulatory model. An essential premise is that regulation requires a multi-faceted balancing enquiry. A holistic approach is proposed where factors such as respect for the dignity of the victims, autonomy for speakers, listeners and the wider community; the causal link between hate speech and hatred in a community; and the desire to achieve a diverse and harmonious society; amongst others, are considered. Failure to regulate hate speech constructively endorses hatemongers and promotes damaging speech at the expense of vulnerable groups. Regulation ensures that law sets the normative benchmark, affirms the protection of vulnerable groups within the social fabric and upholds social cohesion, inclusiveness and the equal citizenship of all individuals in society. The thesis contains a proposal for the enactment of legislation creating a self-standing hate speech crime for the advocacy of extreme hatred, shaped in accordance with international requirements and comparative foreign law, and structured in light of the distinction between hate crime and hate speech. The existing legal framework is unable to provide consistent and fitting redress for the severe harm caused by such speech, namely the fostering of an environment in which the stigmatisation of groups is promoted, their exclusion from society justified and intervention is needed to remedy the escalated levels of hatred and violence between different groups in society. PEPUDA, a remedial statute aimed at promoting transformation and substantive equality, is valuable, but its speech prohibitions are broad and imprecise. Consequently, their effectiveness is compromised and their constitutionality questioned. The thesis proposes recommendations for amendments to sections 7(a), 10(1) and 12 of PEPUDA. The aim is to ensure compliance with the international standard and to foster the optimal regulation of hate speech and other forms of damaging speech, including derogatory racial epithets, which undermine human dignity and equality and threaten national unity. It is intended for the two systems to complement one another and to create a legal framework aimed at addressing hate speech constructively and in context, promoting tolerance, respect for difference, reconciliation and transformation.
- Full Text:
- Date Issued: 2016
- Authors: Botha, Joanna Catherine
- Date: 2016
- Subjects: Freedom of speech -- South Africa , Hate speech -- South Africa , Civil rights -- South Africa
- Language: English
- Type: Thesis , Doctoral , LLD
- Identifier: http://hdl.handle.net/10948/9054 , vital:26460
- Description: Hate speech in South Africa creates a tension between the right to freedom of expression and the rights to human dignity and equality. The challenge is to achieve a balance between these competing rights in the context of the divisive past and the transformative constitutional ideal, in which reconciliation and respect for group difference are promoted. Freedom of expression, an individual right, must be construed in light of its underlying values, but regard must also be given to communitarian interests. The constitutional standard draws the initial line. The advocacy of hatred on four grounds and which constitutes incitement to cause harm is not constitutionally protected speech. Such speech undermines nation building, causes acrimony, and is not tolerated in the egalitarian society envisaged by the Constitution. The thesis formulates a principled legislative hate speech framework for South Africa at both human rights and criminal levels within the parameters of the constitutional mandate, as guided by the standard for hate speech restrictions in international law, and the Canadian regulatory model. An essential premise is that regulation requires a multi-faceted balancing enquiry. A holistic approach is proposed where factors such as respect for the dignity of the victims, autonomy for speakers, listeners and the wider community; the causal link between hate speech and hatred in a community; and the desire to achieve a diverse and harmonious society; amongst others, are considered. Failure to regulate hate speech constructively endorses hatemongers and promotes damaging speech at the expense of vulnerable groups. Regulation ensures that law sets the normative benchmark, affirms the protection of vulnerable groups within the social fabric and upholds social cohesion, inclusiveness and the equal citizenship of all individuals in society. The thesis contains a proposal for the enactment of legislation creating a self-standing hate speech crime for the advocacy of extreme hatred, shaped in accordance with international requirements and comparative foreign law, and structured in light of the distinction between hate crime and hate speech. The existing legal framework is unable to provide consistent and fitting redress for the severe harm caused by such speech, namely the fostering of an environment in which the stigmatisation of groups is promoted, their exclusion from society justified and intervention is needed to remedy the escalated levels of hatred and violence between different groups in society. PEPUDA, a remedial statute aimed at promoting transformation and substantive equality, is valuable, but its speech prohibitions are broad and imprecise. Consequently, their effectiveness is compromised and their constitutionality questioned. The thesis proposes recommendations for amendments to sections 7(a), 10(1) and 12 of PEPUDA. The aim is to ensure compliance with the international standard and to foster the optimal regulation of hate speech and other forms of damaging speech, including derogatory racial epithets, which undermine human dignity and equality and threaten national unity. It is intended for the two systems to complement one another and to create a legal framework aimed at addressing hate speech constructively and in context, promoting tolerance, respect for difference, reconciliation and transformation.
- Full Text:
- Date Issued: 2016
Aspects of prostacyclin in experimental hypertension
- Authors: Botha, Julia Hilary
- Date: 1983
- Subjects: Prostacyclin Prostaglandins Prostaglandin endoperoxides Thromboxanes Hypertension
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3825 , http://hdl.handle.net/10962/d1006109
- Description: A new prostaglandin - prostaglandin X (later renamed prostacyclin or prostaglandin I₂ (PGI₂)), was discovered by Moncada, Gryglewski, Bunting and Vane in 1976. This unstable substance was shown to be produced by vascular tissue and to be a vasodilator and the most potent endogenous inhibitor of platelet aggregation known. Because of its properties, it appeared that a lack of it may be related to the development and or maintenance of hypertension, a disorder featuring vasoconstriction and an increased tendency to arterial thrombosis. The present studies aimed to investigate this possibility using a rat model. A bioassay for prostacyclin was first perfected. This consisted of a modification of the method used by Moncada, Higgs and Vane (1977): PGI₂ released by rat aortic strips, during incubation in tris buffer, was measured by assessing the ability of the incubate to inhibit adenosine diphosphate induced aggregation of human platelets, as compared to the inhibitory effect of standard prostacyclin sodium salt. The specificity of the assay for the detection of PGI₂ was tested. The abil ity of hypertensive rat aorta to release prostacycl in was investigated in two studies. The first compared aortas of Wistar rats of the New Zealand genetically hypertensive strain (GH) with those of matched normotensive Wistar controls. In the second study, hypertension was induced by wrappi ng the ri ght kidney with surgical silk and removing the contralateral kidney. Ten weeks later, aortic generation of prostacyclin by these animals was compared with that of matched sham controls which had received identical surgical manipulation but for the application of silk to the right kidney. Contrary to expectation, in both forms of hypertension, aortas of the rats with elevated pressure produced consistently more prostacyclin than those of matched controls. In order to discover more about the relationship between elevated pressure and elevated PGI₂ production, the effect of pressure reduction with hypotensive agents on the ability of GH rat aortas to produce prostacyclin, was investigated. After pressure had been controlled within normal range for one week (achieved by oral administration of furosemide, dihydralazine and reserpine for one month), aortic PGI₂ was reduced in comparison with matched GH controls. However, the reduction was not consistent and statistical significance was not reached. Because it was subsequently reported by other workers, that some of the hypotensive agents which had been employed may effect prostaglandin levels per se, no conclusions could be drawn from this study as to any possible direct relationships between pressure and aortic prostacyclin generating capacity. A further means of reducing elevated pressure (which had no inherent effect on prostaglandin levels) was thus sought. A mechanical method was eventually selected, application of a silver clip to the aortas of GH rats, just below the diaphragm, producing an immediate reduction in pressure distal to the constriction. Eighteen hours with later, PGI₂ production by these distal aortas those of matched sham GH controls and was was compared found to be consistently reduced. These results indicate that the ability to produce PGI₂ may be influenced by prior local pressure changes and that the increased capacity of hypertensive rat aortas to generate prostacyclin may be related to the increased mechanical transmural stress consequent on elevated pressure. Since haemostatic balance must be influenced not only by vascular PGI₂ generation but also by platelet sensitivity to PGI₂, the response of GH platelets to the anti-aggregatory effect of prostacyc1in was also investigated. As it had been shown by Sinzinger, Si1berbauer, Horsch and Gall (1981) that intra-arterial infusion of PGI₂ in humans decreased platelet sensitivity to the substance, the possibility existed that platelet sensitivity in hypertension might be reduced. This hypothesis was, however, invalidated as the sensitivity of GH platelets to the anti-aggregatory effect of PGI₂ was almost identical to that of normotensive controls. The shortcomings of the methodology and the possible importance of these findings in the hypertensive animal are discussed. The idea that elevated PGI₂ in hypertension may play a protective role both with respect to platelet aggregation and in attenuating further pressure rises is considered. It is finally suggested that it will be possible to draw more accurate conclusions as to the meaning of the increased PGI₂ generation in hypertension (both in relation to vascular tone and platelet function) only when details of production of, and sensitivity to, thromboxane A₂ are known. Thromboxane A₂ (TXA₂) is a vasoconstrictor and promotor of aggregation (Hamberg, Svensson and Samuelson, 1975) and it may be that, despite elevated vascular PGI₂ generation, the TXA₂/PGI₂ balance is still tipped in favour of vasoconstriction and platelet aggregation in hypertension.
- Full Text:
- Date Issued: 1983
- Authors: Botha, Julia Hilary
- Date: 1983
- Subjects: Prostacyclin Prostaglandins Prostaglandin endoperoxides Thromboxanes Hypertension
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3825 , http://hdl.handle.net/10962/d1006109
- Description: A new prostaglandin - prostaglandin X (later renamed prostacyclin or prostaglandin I₂ (PGI₂)), was discovered by Moncada, Gryglewski, Bunting and Vane in 1976. This unstable substance was shown to be produced by vascular tissue and to be a vasodilator and the most potent endogenous inhibitor of platelet aggregation known. Because of its properties, it appeared that a lack of it may be related to the development and or maintenance of hypertension, a disorder featuring vasoconstriction and an increased tendency to arterial thrombosis. The present studies aimed to investigate this possibility using a rat model. A bioassay for prostacyclin was first perfected. This consisted of a modification of the method used by Moncada, Higgs and Vane (1977): PGI₂ released by rat aortic strips, during incubation in tris buffer, was measured by assessing the ability of the incubate to inhibit adenosine diphosphate induced aggregation of human platelets, as compared to the inhibitory effect of standard prostacyclin sodium salt. The specificity of the assay for the detection of PGI₂ was tested. The abil ity of hypertensive rat aorta to release prostacycl in was investigated in two studies. The first compared aortas of Wistar rats of the New Zealand genetically hypertensive strain (GH) with those of matched normotensive Wistar controls. In the second study, hypertension was induced by wrappi ng the ri ght kidney with surgical silk and removing the contralateral kidney. Ten weeks later, aortic generation of prostacyclin by these animals was compared with that of matched sham controls which had received identical surgical manipulation but for the application of silk to the right kidney. Contrary to expectation, in both forms of hypertension, aortas of the rats with elevated pressure produced consistently more prostacyclin than those of matched controls. In order to discover more about the relationship between elevated pressure and elevated PGI₂ production, the effect of pressure reduction with hypotensive agents on the ability of GH rat aortas to produce prostacyclin, was investigated. After pressure had been controlled within normal range for one week (achieved by oral administration of furosemide, dihydralazine and reserpine for one month), aortic PGI₂ was reduced in comparison with matched GH controls. However, the reduction was not consistent and statistical significance was not reached. Because it was subsequently reported by other workers, that some of the hypotensive agents which had been employed may effect prostaglandin levels per se, no conclusions could be drawn from this study as to any possible direct relationships between pressure and aortic prostacyclin generating capacity. A further means of reducing elevated pressure (which had no inherent effect on prostaglandin levels) was thus sought. A mechanical method was eventually selected, application of a silver clip to the aortas of GH rats, just below the diaphragm, producing an immediate reduction in pressure distal to the constriction. Eighteen hours with later, PGI₂ production by these distal aortas those of matched sham GH controls and was was compared found to be consistently reduced. These results indicate that the ability to produce PGI₂ may be influenced by prior local pressure changes and that the increased capacity of hypertensive rat aortas to generate prostacyclin may be related to the increased mechanical transmural stress consequent on elevated pressure. Since haemostatic balance must be influenced not only by vascular PGI₂ generation but also by platelet sensitivity to PGI₂, the response of GH platelets to the anti-aggregatory effect of prostacyc1in was also investigated. As it had been shown by Sinzinger, Si1berbauer, Horsch and Gall (1981) that intra-arterial infusion of PGI₂ in humans decreased platelet sensitivity to the substance, the possibility existed that platelet sensitivity in hypertension might be reduced. This hypothesis was, however, invalidated as the sensitivity of GH platelets to the anti-aggregatory effect of PGI₂ was almost identical to that of normotensive controls. The shortcomings of the methodology and the possible importance of these findings in the hypertensive animal are discussed. The idea that elevated PGI₂ in hypertension may play a protective role both with respect to platelet aggregation and in attenuating further pressure rises is considered. It is finally suggested that it will be possible to draw more accurate conclusions as to the meaning of the increased PGI₂ generation in hypertension (both in relation to vascular tone and platelet function) only when details of production of, and sensitivity to, thromboxane A₂ are known. Thromboxane A₂ (TXA₂) is a vasoconstrictor and promotor of aggregation (Hamberg, Svensson and Samuelson, 1975) and it may be that, despite elevated vascular PGI₂ generation, the TXA₂/PGI₂ balance is still tipped in favour of vasoconstriction and platelet aggregation in hypertension.
- Full Text:
- Date Issued: 1983
Die outobiografiese kode in Antjie Krog se poëtiese oeuvre
- Authors: Botha, Maria Elizabeth
- Date: 2011
- Subjects: Krog, Antjie -- Criticism and interpretation , Autobiography -- History and criticism , Afrikaans poetry -- 20th century -- History and criticism
- Language: Afrikaans
- Type: Thesis , Doctoral , DLitt
- Identifier: vital:8444 , http://hdl.handle.net/10948/1534 , Krog, Antjie -- Criticism and interpretation , Autobiography -- History and criticism , Afrikaans poetry -- 20th century -- History and criticism
- Description: This study primarily investigates the autobiographical code in Antjie Krog's poetical oeuvre, spanning from 1970 to the present. Krog's poetry collections may be read as offering life writing through poetry, while the prose works mostly present the reader with a mixture of autobiographical fact plus creative reworkings of fact and fiction. Even though her 10 volumes of poetry follow her biological development from young girl to grandmother, uncertainty still exists about about where truth ends and fiction begins in this poet and autobiographer's interwoven tapestry of multiple and varied perspectives. Furthermore, autobiographical (as utilised and adapted in Krog's oeuvre, in combination with the conventioans from other genres), offers a variety of creatively innovative, experimental strategies and possibilities exploited adroitly by Krog. Reading her poetry with the focus on autobiographical markers leads to another, mostly untapped, dimension of interpretation. This literary approach is in stark contrast to the approach prescibed by N.P. van Wyk Louw in "Die 'mens' agter die boek" ["The 'Person' behind the Book] (1956), in which he states clearly that a text should be interpreted as not "about the human behind the text". To a large extent Krog as poet is inviting the reader to consciously break the taboo that Louw placed on the reader intent on "searching the actual person behind the text". My hypothesis is that in Krog's poetry there is a distinct interrelationship between the perceptions, experiences and sensual impressions of the lyrical "I" in the poems and that of the authobiographical "I" writing. It would be irresponsible to declare the poet and the speaker as one and the same, but in instances where the poet purposefully integrates autobiographical elements into her poems, she is implicitly requesting the reader to interpret her work in this way. This fictive and implicit request is referred to by Philippe Lejeune as the autobiographical poet. Krog's poetry can be divided into four categories: "direct autobiographical", "indirect autobiographical", "universal" and "general" poems. The first category involves criteria that are linked to the poet, such as the use of the names, initials and dates. Indirect autobiographical poems can be read against the background of knowledge (previously published information) about the poet. Poetry with no apparent autobiographical element, but with universal themes such as love, loss and transience, fall into the third category of "universal" poetry. If poems do not fit into the mentioned categories, they are deemed "general".
- Full Text:
- Date Issued: 2011
- Authors: Botha, Maria Elizabeth
- Date: 2011
- Subjects: Krog, Antjie -- Criticism and interpretation , Autobiography -- History and criticism , Afrikaans poetry -- 20th century -- History and criticism
- Language: Afrikaans
- Type: Thesis , Doctoral , DLitt
- Identifier: vital:8444 , http://hdl.handle.net/10948/1534 , Krog, Antjie -- Criticism and interpretation , Autobiography -- History and criticism , Afrikaans poetry -- 20th century -- History and criticism
- Description: This study primarily investigates the autobiographical code in Antjie Krog's poetical oeuvre, spanning from 1970 to the present. Krog's poetry collections may be read as offering life writing through poetry, while the prose works mostly present the reader with a mixture of autobiographical fact plus creative reworkings of fact and fiction. Even though her 10 volumes of poetry follow her biological development from young girl to grandmother, uncertainty still exists about about where truth ends and fiction begins in this poet and autobiographer's interwoven tapestry of multiple and varied perspectives. Furthermore, autobiographical (as utilised and adapted in Krog's oeuvre, in combination with the conventioans from other genres), offers a variety of creatively innovative, experimental strategies and possibilities exploited adroitly by Krog. Reading her poetry with the focus on autobiographical markers leads to another, mostly untapped, dimension of interpretation. This literary approach is in stark contrast to the approach prescibed by N.P. van Wyk Louw in "Die 'mens' agter die boek" ["The 'Person' behind the Book] (1956), in which he states clearly that a text should be interpreted as not "about the human behind the text". To a large extent Krog as poet is inviting the reader to consciously break the taboo that Louw placed on the reader intent on "searching the actual person behind the text". My hypothesis is that in Krog's poetry there is a distinct interrelationship between the perceptions, experiences and sensual impressions of the lyrical "I" in the poems and that of the authobiographical "I" writing. It would be irresponsible to declare the poet and the speaker as one and the same, but in instances where the poet purposefully integrates autobiographical elements into her poems, she is implicitly requesting the reader to interpret her work in this way. This fictive and implicit request is referred to by Philippe Lejeune as the autobiographical poet. Krog's poetry can be divided into four categories: "direct autobiographical", "indirect autobiographical", "universal" and "general" poems. The first category involves criteria that are linked to the poet, such as the use of the names, initials and dates. Indirect autobiographical poems can be read against the background of knowledge (previously published information) about the poet. Poetry with no apparent autobiographical element, but with universal themes such as love, loss and transience, fall into the third category of "universal" poetry. If poems do not fit into the mentioned categories, they are deemed "general".
- Full Text:
- Date Issued: 2011
A gatherer’s paradise? early humans and plant foraging on the Cape south coast, South Africa
- Authors: Botha, Maria Susan
- Date: 2019
- Subjects: Plant remains (Archaeology) -- South Africa , Plant physiology Plant ecology Botany -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/37139 , vital:34124
- Description: Humans were driven to refugia during the cold and dry glacial Marine Isotope Stage 6 (MIS6) (~195–125 ka); only a few places, including the Cape south coast, show archaeological evidence of continuous human occupation. It has been hypothesised that the Cape south coast provided the requisite shelter to ensure human’s earliest survival because it provided all the right ingredients. The shores offer abundant shellfish, the land a diverse array of plants, and the climate was ameliorated due to the proximity of the then exposed Palaeo-Agulhas Plain to the warm Agulhas current. The aim of this study is to determine whether the indigenous flora of this region could have provided a sufficient edible resource for early humans. Residents of the Cape south coast have genetic ancestry linking them to the Khoe-San, the original inhabitants of the area, and still have an extensive knowledge of the local edible plants. With their help, I set out to determine a) whether humans have been utilising the same plant species over time, b) what the foraging potential of the edible plants in the region is and c) how resilient these plants are to human foraging. If we know whether the plant species known and used today were the same as those that were utilised by past humans, we can then use the contemporary knowledge to make predictions about past utilisation. To answer this question, I collated two databases: archaeological (all plant species found in archaeological sites [dating 0 to 80,000 BP]) and contemporary (all plant species in the modern-day ethnographic literature [last 400 years]) that occur within the Greater Cape Floristic Region(GCFR). I found a significant number of plant species shared between the two databases, which suggests that at least some plant species have been used by humans over a long period of time. To determine the indigenous plant foraging potential of the region, I foraged for food in the Cape south coast (451 bouts) monthly over a two-year period with the help of local inhabitants. The findings show that edible plant resources are distributed patchily and focusing on specific vegetation types would greatly enhance chances of harvesting 2,000 kcal per day, which is considered the daily calorific requirements for a typical hunter-gatherer. I then sought to understand how resilient these plants [(with an emphasis on plants with an underground storage organ (USO)] would be to human foraging. To do this, I set out plots and harvested all edible foods for three consecutive years with the help of foragers. Results indicate that there was a significant reduction in edible weight only in the third year of consecutive harvesting. In conclusion, using various approaches, this study investigates the plant food potential of the Cape south coast from the perspective of early human consumers. The findings suggest that knowledge regarding useful plants dates back to at least 80,000 BP. Food resources are patchily distributed across the main vegetation types found within the Cape south coast and occur in hotspots, i.e. concentrated areas hosting high densities of edible plant foods, surrounded by areas with very low plant food densities. Foragers could have harvested their daily calorific quota more easily if they focused their harvesting efforts in specific vegetation types found in the Cape south coast. Furthermore, many USOs circumvent climatic fluctuations, herbivory or both by staggering their emergence over multiple years, which implies they have some resilience to human foraging.
- Full Text:
- Date Issued: 2019
- Authors: Botha, Maria Susan
- Date: 2019
- Subjects: Plant remains (Archaeology) -- South Africa , Plant physiology Plant ecology Botany -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/37139 , vital:34124
- Description: Humans were driven to refugia during the cold and dry glacial Marine Isotope Stage 6 (MIS6) (~195–125 ka); only a few places, including the Cape south coast, show archaeological evidence of continuous human occupation. It has been hypothesised that the Cape south coast provided the requisite shelter to ensure human’s earliest survival because it provided all the right ingredients. The shores offer abundant shellfish, the land a diverse array of plants, and the climate was ameliorated due to the proximity of the then exposed Palaeo-Agulhas Plain to the warm Agulhas current. The aim of this study is to determine whether the indigenous flora of this region could have provided a sufficient edible resource for early humans. Residents of the Cape south coast have genetic ancestry linking them to the Khoe-San, the original inhabitants of the area, and still have an extensive knowledge of the local edible plants. With their help, I set out to determine a) whether humans have been utilising the same plant species over time, b) what the foraging potential of the edible plants in the region is and c) how resilient these plants are to human foraging. If we know whether the plant species known and used today were the same as those that were utilised by past humans, we can then use the contemporary knowledge to make predictions about past utilisation. To answer this question, I collated two databases: archaeological (all plant species found in archaeological sites [dating 0 to 80,000 BP]) and contemporary (all plant species in the modern-day ethnographic literature [last 400 years]) that occur within the Greater Cape Floristic Region(GCFR). I found a significant number of plant species shared between the two databases, which suggests that at least some plant species have been used by humans over a long period of time. To determine the indigenous plant foraging potential of the region, I foraged for food in the Cape south coast (451 bouts) monthly over a two-year period with the help of local inhabitants. The findings show that edible plant resources are distributed patchily and focusing on specific vegetation types would greatly enhance chances of harvesting 2,000 kcal per day, which is considered the daily calorific requirements for a typical hunter-gatherer. I then sought to understand how resilient these plants [(with an emphasis on plants with an underground storage organ (USO)] would be to human foraging. To do this, I set out plots and harvested all edible foods for three consecutive years with the help of foragers. Results indicate that there was a significant reduction in edible weight only in the third year of consecutive harvesting. In conclusion, using various approaches, this study investigates the plant food potential of the Cape south coast from the perspective of early human consumers. The findings suggest that knowledge regarding useful plants dates back to at least 80,000 BP. Food resources are patchily distributed across the main vegetation types found within the Cape south coast and occur in hotspots, i.e. concentrated areas hosting high densities of edible plant foods, surrounded by areas with very low plant food densities. Foragers could have harvested their daily calorific quota more easily if they focused their harvesting efforts in specific vegetation types found in the Cape south coast. Furthermore, many USOs circumvent climatic fluctuations, herbivory or both by staggering their emergence over multiple years, which implies they have some resilience to human foraging.
- Full Text:
- Date Issued: 2019
NeGPAIM : a model for the proactive detection of information security intrusions, utilizing fuzzy logic and neural network techniques
- Authors: Botha, Martin
- Date: 2003
- Subjects: Computer security , Fuzzy logic , Neural networks (Computer science)
- Language: English
- Type: Thesis , Doctoral , DTech (Computer Studies)
- Identifier: vital:10792 , http://hdl.handle.net/10948/142 , Computer security , Fuzzy logic , Neural networks (Computer science)
- Description: “Information is the lifeblood of any organisation and everything an organisation does involves using information in some way” (Peppard, 1993, p.5). Therefore, it can be argued that information is an organisation’s most precious asset and as with all other assets, like equipment, money, personnel, and so on, this asset needs to be protected properly at all times (Whitman & Mattord, 2003, pp.1-14). The introduction of modern technologies, such as e-commerce, will not only increase the value of information, but will also increase security requirements of those organizations that are intending to utilize such technologies. Evidence of these requirements can be observed in the 2001 CSI/FBI Computer Crime and Security Survey (Power, 2001). According to this source, the annual financial losses caused through security breaches in 2001 have increased by 277% when compared to the results from 1997. The 2002 and 2003 Computer Crime and Security Survey confirms this by stating that the threat of computer crime and other related information security breaches continues unabated and that the financial toll is mounting (Richardson, 2003). Information is normally protected by means of a process of identifying, implementing, managing and maintaining a set of information security controls, countermeasures or safeguards (GMITS, 1998). In the rest of this thesis, the term security controls will be utilized when referring to information protection mechanisms or procedures. These security controls can be of a physical (for example, door locks), a technical (for example, passwords) and/or a procedural nature (for example, to make back-up copies of critical files)(Pfleeger, 2003, pp.22-23; Stallings, 1995, p.1). The effective identification, implementation, management and maintenance of this set of security controls are usually integrated into an Information Security Management Program, the objective of which is to ensure an acceptable level of information confidentiality, integrity and availability within the organisation at all times (Pfleeger, 2003, pp.10-12; Whitman & Mattord, 2003, pp.1-14; Von Solms, 1993). Once the most effective security controls have been identified and implemented, it is important that this level of security be maintained through a process of continued control. For this reason, it is important that proper change management, measurement, audit, monitoring and detection be implemented (Bruce & Dempsey, 1997). Monitoring and detection are important functions and refer to the ability to identify and detect situations where information security policies have been compromised and/or breached or security violations have taken place (BS 7799, 1999; GMITS, 1998; Von Solms, 1993). The Information Security Officer is usually the person responsible for most of the operational tasks in the control process within an Information Security Management Program (Von Solms, 1993). In practice, these tasks could also be performed by a system administrator, network administrator, etc. In the rest of the thesis the person responsible for these tasks will be referred to as system administrator. These tasks have proved to be very challenging and demanding. The main reason for this is the rapid advancement of technology in the discipline of Information Technology, for example, the modern distributed computing environment, the Internet, the “freedom” of end-users, the introduction of e-commerce, and etc. (Whitman & Mattord, 2003, p.9; Sundaram, 2000, p.1; Moses, 2001, p.6; Allen, 2001, p.1). As a result of the importance of this control process, and especially the monitoring and detection tasks, it is vital that the system administrator has proper tools at his/her disposal to perform this task effectively. Many of the tools that are currently available to the system administrator, utilize technical controls, such as, audit logs and user profiles. Audit logs are normally used to record all events executed on a system. These logs are simply files that record security and non-security related events that take place on a computer system within an organisation. For this reason, these logs can be used by these tools to gain valuable information on security violations, such as intrusions and, therefore, are able to monitor the current actions of each user (Microsoft, 2002; Smith, 1989, pp. 116-117). User profiles are files that contain information about users` desktop operating environments and are used by the operating system to structure each user environment so that it is the same each time a user logs onto the system (Microsoft, 2002; Block, 1994, p.54). Thus, a user profile is used to indicate which actions the user is allowed to perform on the system. Both technical controls (audit logs and user profiles) are frequently available in most computer environments (such as, UNIX, Firewalls, Windows, etc.) (Cooper et al, 1995, p.129). Therefore, seeing that the audit logs record most events taking place on an information system and the user profile indicates the authorized actions of each user, the system administrator could most probably utilise these controls in a more proactive manner.
- Full Text:
- Date Issued: 2003
- Authors: Botha, Martin
- Date: 2003
- Subjects: Computer security , Fuzzy logic , Neural networks (Computer science)
- Language: English
- Type: Thesis , Doctoral , DTech (Computer Studies)
- Identifier: vital:10792 , http://hdl.handle.net/10948/142 , Computer security , Fuzzy logic , Neural networks (Computer science)
- Description: “Information is the lifeblood of any organisation and everything an organisation does involves using information in some way” (Peppard, 1993, p.5). Therefore, it can be argued that information is an organisation’s most precious asset and as with all other assets, like equipment, money, personnel, and so on, this asset needs to be protected properly at all times (Whitman & Mattord, 2003, pp.1-14). The introduction of modern technologies, such as e-commerce, will not only increase the value of information, but will also increase security requirements of those organizations that are intending to utilize such technologies. Evidence of these requirements can be observed in the 2001 CSI/FBI Computer Crime and Security Survey (Power, 2001). According to this source, the annual financial losses caused through security breaches in 2001 have increased by 277% when compared to the results from 1997. The 2002 and 2003 Computer Crime and Security Survey confirms this by stating that the threat of computer crime and other related information security breaches continues unabated and that the financial toll is mounting (Richardson, 2003). Information is normally protected by means of a process of identifying, implementing, managing and maintaining a set of information security controls, countermeasures or safeguards (GMITS, 1998). In the rest of this thesis, the term security controls will be utilized when referring to information protection mechanisms or procedures. These security controls can be of a physical (for example, door locks), a technical (for example, passwords) and/or a procedural nature (for example, to make back-up copies of critical files)(Pfleeger, 2003, pp.22-23; Stallings, 1995, p.1). The effective identification, implementation, management and maintenance of this set of security controls are usually integrated into an Information Security Management Program, the objective of which is to ensure an acceptable level of information confidentiality, integrity and availability within the organisation at all times (Pfleeger, 2003, pp.10-12; Whitman & Mattord, 2003, pp.1-14; Von Solms, 1993). Once the most effective security controls have been identified and implemented, it is important that this level of security be maintained through a process of continued control. For this reason, it is important that proper change management, measurement, audit, monitoring and detection be implemented (Bruce & Dempsey, 1997). Monitoring and detection are important functions and refer to the ability to identify and detect situations where information security policies have been compromised and/or breached or security violations have taken place (BS 7799, 1999; GMITS, 1998; Von Solms, 1993). The Information Security Officer is usually the person responsible for most of the operational tasks in the control process within an Information Security Management Program (Von Solms, 1993). In practice, these tasks could also be performed by a system administrator, network administrator, etc. In the rest of the thesis the person responsible for these tasks will be referred to as system administrator. These tasks have proved to be very challenging and demanding. The main reason for this is the rapid advancement of technology in the discipline of Information Technology, for example, the modern distributed computing environment, the Internet, the “freedom” of end-users, the introduction of e-commerce, and etc. (Whitman & Mattord, 2003, p.9; Sundaram, 2000, p.1; Moses, 2001, p.6; Allen, 2001, p.1). As a result of the importance of this control process, and especially the monitoring and detection tasks, it is vital that the system administrator has proper tools at his/her disposal to perform this task effectively. Many of the tools that are currently available to the system administrator, utilize technical controls, such as, audit logs and user profiles. Audit logs are normally used to record all events executed on a system. These logs are simply files that record security and non-security related events that take place on a computer system within an organisation. For this reason, these logs can be used by these tools to gain valuable information on security violations, such as intrusions and, therefore, are able to monitor the current actions of each user (Microsoft, 2002; Smith, 1989, pp. 116-117). User profiles are files that contain information about users` desktop operating environments and are used by the operating system to structure each user environment so that it is the same each time a user logs onto the system (Microsoft, 2002; Block, 1994, p.54). Thus, a user profile is used to indicate which actions the user is allowed to perform on the system. Both technical controls (audit logs and user profiles) are frequently available in most computer environments (such as, UNIX, Firewalls, Windows, etc.) (Cooper et al, 1995, p.129). Therefore, seeing that the audit logs record most events taking place on an information system and the user profile indicates the authorized actions of each user, the system administrator could most probably utilise these controls in a more proactive manner.
- Full Text:
- Date Issued: 2003
Characterisation of the plasmodium falciparum Hsp40 chaperones and their partnerships with Hsp70
- Authors: Botha, Melissa
- Date: 2009
- Subjects: Heat shock proteins Plasmodium falciparum Protein folding Molecular chaperones Malaria
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3938 , http://hdl.handle.net/10962/d1003997
- Description: Central to this research, 40 kDa Heat shock proteins (Hsp40s) are known to partner (or cochaperone) 70 kDa Heat shock proteins (Hsp70s), facilitating the selection and transfer of protein substrate to Hsp70 and the stimulation of the protein folding ability of Hsp70. Members of the diverse Hsp70-Hsp40 protein complement of Plasmodium falciparum have been implicated in the cytoprotection of this malaria parasite, and are thought to facilitate the protein folding, assembly and translocation tasks required by the parasite to commandeer the infected human erythrocyte subsequent to invasion. In particular, the parasite has evolved an expanded and specialised 43- member suite of Hsp40 proteins, 19 of which bear an identifiable export motif for secretion into the infected erythrocyte cytoplasm where they potentially interact with human Hsp70. Although type I Hsp40 proteins are representative of typical regulators of Hsp70 activity, only two of these proteins are apparent in the parasite’s Hsp40 complement. These include a characteristic type I Hsp40 termed PfHsp40, and a larger, atypical type I Hsp40 termed Pfj1. Both Hsp40 proteins are predicted to be parasite-resident and are most likely to facilitate the co-chaperone regulation of the highly abundant and stress-inducible Hsp70 homolog, PfHsp70-I. In this work, the co-chaperone functionality of PfHsp40 and Pfj1 was elucidated using in vivo and in vitro assays. Purified recombinant PfHsp40 was shown to stimulate the ATPase activity of PfHsp70-I in in vitro single turnover and steady state ATPase assays, and co-operate with PfHsp70-I in in vitro aggregation suppression assays. In these in vitro assays, heterologous partnerships could be demonstrated between PfHsp70-I and the human Hsp40, Hsj1a, and human Hsp70 and PfHsp40, suggesting a common mode of Hsp70-Hsp40 interaction in the parasite and host organism. The functionality of the signature Hsp40 domain, the Jdomain, of Pfj1 was demonstrated by its ability to replace the equivalent domain of the A. tumefaciens Hsp40, Agt DnaJ, in interactions with the prokaryotic Hsp70, DnaK, in the thermosensitive dnaJ cbpA E. coli OD259 deletion strain. An H33Q mutation introduced into the invariant and crucial HPD tripeptide motif abrogated the functionality of the J-domain in the in vivo complementation system. These findings provide the first evidence for the conservation of the prototypical mode of J-domain based interaction of Hsp40 with Hsp70 in P. falciparum. Immunofluorescence staining revealed the localisation of PfHsp40 to the parasite cytoplasm, and Pfj1 to the parasite cytoplasm and nucleus in cultured intraerythrocytic stage P. falciparum parasites. PfHsp70-I was also shown to localise to the parasite cytoplasm and nucleus in these stages, consistent with the literature. Overall we propose that PfHsp40 and Pfj1 co-localise with and regulate the chaperone activity of PfHsp70-I in P. falciparum. This is the first study to identify and provide evidence for a functional Hsp70-Hsp40 partnership in P. falciparum, and provides a platform for future studies to elucidate the importance of these chaperone partnerships in the establishment and survival of the parasite in the intraerythrocytic-stages of development.
- Full Text:
- Date Issued: 2009
- Authors: Botha, Melissa
- Date: 2009
- Subjects: Heat shock proteins Plasmodium falciparum Protein folding Molecular chaperones Malaria
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3938 , http://hdl.handle.net/10962/d1003997
- Description: Central to this research, 40 kDa Heat shock proteins (Hsp40s) are known to partner (or cochaperone) 70 kDa Heat shock proteins (Hsp70s), facilitating the selection and transfer of protein substrate to Hsp70 and the stimulation of the protein folding ability of Hsp70. Members of the diverse Hsp70-Hsp40 protein complement of Plasmodium falciparum have been implicated in the cytoprotection of this malaria parasite, and are thought to facilitate the protein folding, assembly and translocation tasks required by the parasite to commandeer the infected human erythrocyte subsequent to invasion. In particular, the parasite has evolved an expanded and specialised 43- member suite of Hsp40 proteins, 19 of which bear an identifiable export motif for secretion into the infected erythrocyte cytoplasm where they potentially interact with human Hsp70. Although type I Hsp40 proteins are representative of typical regulators of Hsp70 activity, only two of these proteins are apparent in the parasite’s Hsp40 complement. These include a characteristic type I Hsp40 termed PfHsp40, and a larger, atypical type I Hsp40 termed Pfj1. Both Hsp40 proteins are predicted to be parasite-resident and are most likely to facilitate the co-chaperone regulation of the highly abundant and stress-inducible Hsp70 homolog, PfHsp70-I. In this work, the co-chaperone functionality of PfHsp40 and Pfj1 was elucidated using in vivo and in vitro assays. Purified recombinant PfHsp40 was shown to stimulate the ATPase activity of PfHsp70-I in in vitro single turnover and steady state ATPase assays, and co-operate with PfHsp70-I in in vitro aggregation suppression assays. In these in vitro assays, heterologous partnerships could be demonstrated between PfHsp70-I and the human Hsp40, Hsj1a, and human Hsp70 and PfHsp40, suggesting a common mode of Hsp70-Hsp40 interaction in the parasite and host organism. The functionality of the signature Hsp40 domain, the Jdomain, of Pfj1 was demonstrated by its ability to replace the equivalent domain of the A. tumefaciens Hsp40, Agt DnaJ, in interactions with the prokaryotic Hsp70, DnaK, in the thermosensitive dnaJ cbpA E. coli OD259 deletion strain. An H33Q mutation introduced into the invariant and crucial HPD tripeptide motif abrogated the functionality of the J-domain in the in vivo complementation system. These findings provide the first evidence for the conservation of the prototypical mode of J-domain based interaction of Hsp40 with Hsp70 in P. falciparum. Immunofluorescence staining revealed the localisation of PfHsp40 to the parasite cytoplasm, and Pfj1 to the parasite cytoplasm and nucleus in cultured intraerythrocytic stage P. falciparum parasites. PfHsp70-I was also shown to localise to the parasite cytoplasm and nucleus in these stages, consistent with the literature. Overall we propose that PfHsp40 and Pfj1 co-localise with and regulate the chaperone activity of PfHsp70-I in P. falciparum. This is the first study to identify and provide evidence for a functional Hsp70-Hsp40 partnership in P. falciparum, and provides a platform for future studies to elucidate the importance of these chaperone partnerships in the establishment and survival of the parasite in the intraerythrocytic-stages of development.
- Full Text:
- Date Issued: 2009
The role of reasonableness in the review of CCMA arbitration awards in South Africa : an English law comparison
- Authors: Botma-Kleu, Carli Helena
- Date: 2013
- Subjects: Arbitration and award -- South Africa , Labor courts -- South Africa , Law -- South Africa -- English influences
- Language: English
- Type: Thesis , Doctoral , LLD
- Identifier: vital:10291 , http://hdl.handle.net/10948/d1020196
- Description: In South Africa, the Labour Courts have experienced an important and continuing controversy regarding the permissible scope of judicial review of arbitration awards of the Commission for Conciliation Mediation and Arbitration (“CCMA”) in terms of section 145 of the Labour Relations Act 66 of 1995 (“LRA”). Section 145(1) of the LRA specifically provides that arbitration awards, generally considered final and binding, can be reviewed and set aside by the Labour Court on the basis of a defect as defined in section 145(2)(a) and (b). These defects are not prescribed in an open-ended manner but limited to decisions involving allegations of misconduct by the commissioner in relation to his or her duties, a gross irregularity in the conduct of the proceedings and/or allegations that the commissioner exceeded his or her powers or that the award was improperly obtained. Unreasonableness and/or irrationality are not included within the scope of a defect as per section 145(2)(a) and (b). Initially, Carephone (Pty) Ltd v Marcus NO & others 1998 11 BLLR 1093 (LAC) found that the interpretation of section 145 was influenced by rational justifiability in accordance with the right to just administrative action as provided for in section 33, read with item 23(2) of Schedule 6, of the Constitution of the Republic of South Africa, 1996 (‘the 1996 Constitution’). Today, leading precedent in the form of Sidumo & another v Rustenburg Platinum Mines Ltd & others 2007 12 BLLR 1097 (CC) dictates that section 145 of the LRA is suffused by reasonableness in accordance with the right to just administrative action as provided for in section 33 of the 1996 Constitution. The ultimate enquiry is whether the arbitration award is one that a reasonable decision-maker could reach as articulated in Bato Star Fishing (Pty) Ltd v Minister of Environmental Affairs and Tourism and others 2004 4 SA 490 (CC). However, the enquiry into the reasonableness of a decision is indistinct. As a result, the Labour Courts have struggled to apply the concept of reasonableness in a consistent manner. This thesis seeks to identify the proper role of reasonableness in the judicial review process, including identifying factors that would assist in recognising an unreasonable decision. Relevant principles of judicial review in South Africa in the general administrative law context are considered and distinguished from the process of appeal. An assessment of English case law and commentary in the field of both administrative and employment law is conducted. Finally an extensive examination of South African case law and commentary on the subject, both pre- and post Sidumo, is undertaken. The English law approach is found to provide greater clarity to the interpretation of reasonableness in South African labour law in several respects.
- Full Text:
- Date Issued: 2013
- Authors: Botma-Kleu, Carli Helena
- Date: 2013
- Subjects: Arbitration and award -- South Africa , Labor courts -- South Africa , Law -- South Africa -- English influences
- Language: English
- Type: Thesis , Doctoral , LLD
- Identifier: vital:10291 , http://hdl.handle.net/10948/d1020196
- Description: In South Africa, the Labour Courts have experienced an important and continuing controversy regarding the permissible scope of judicial review of arbitration awards of the Commission for Conciliation Mediation and Arbitration (“CCMA”) in terms of section 145 of the Labour Relations Act 66 of 1995 (“LRA”). Section 145(1) of the LRA specifically provides that arbitration awards, generally considered final and binding, can be reviewed and set aside by the Labour Court on the basis of a defect as defined in section 145(2)(a) and (b). These defects are not prescribed in an open-ended manner but limited to decisions involving allegations of misconduct by the commissioner in relation to his or her duties, a gross irregularity in the conduct of the proceedings and/or allegations that the commissioner exceeded his or her powers or that the award was improperly obtained. Unreasonableness and/or irrationality are not included within the scope of a defect as per section 145(2)(a) and (b). Initially, Carephone (Pty) Ltd v Marcus NO & others 1998 11 BLLR 1093 (LAC) found that the interpretation of section 145 was influenced by rational justifiability in accordance with the right to just administrative action as provided for in section 33, read with item 23(2) of Schedule 6, of the Constitution of the Republic of South Africa, 1996 (‘the 1996 Constitution’). Today, leading precedent in the form of Sidumo & another v Rustenburg Platinum Mines Ltd & others 2007 12 BLLR 1097 (CC) dictates that section 145 of the LRA is suffused by reasonableness in accordance with the right to just administrative action as provided for in section 33 of the 1996 Constitution. The ultimate enquiry is whether the arbitration award is one that a reasonable decision-maker could reach as articulated in Bato Star Fishing (Pty) Ltd v Minister of Environmental Affairs and Tourism and others 2004 4 SA 490 (CC). However, the enquiry into the reasonableness of a decision is indistinct. As a result, the Labour Courts have struggled to apply the concept of reasonableness in a consistent manner. This thesis seeks to identify the proper role of reasonableness in the judicial review process, including identifying factors that would assist in recognising an unreasonable decision. Relevant principles of judicial review in South Africa in the general administrative law context are considered and distinguished from the process of appeal. An assessment of English case law and commentary in the field of both administrative and employment law is conducted. Finally an extensive examination of South African case law and commentary on the subject, both pre- and post Sidumo, is undertaken. The English law approach is found to provide greater clarity to the interpretation of reasonableness in South African labour law in several respects.
- Full Text:
- Date Issued: 2013
The in vitro biological activities of three Hypoxis species and their active compounds
- Authors: Boukes, Gerhardt Johannes
- Date: 2010
- Subjects: Potatoes -- Africa , Potatoes -- Therapeutic use , Medicinal plants
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10322 , http://hdl.handle.net/10948/1228 , Potatoes -- Africa , Potatoes -- Therapeutic use , Medicinal plants
- Description: The African potato is used as an African traditional medicine for its nutritional and medicinal properties. Most research has been carried out on H. hemerocallidea, with very little or nothing on other Hypoxis spp. The main aim of this project was to provide scientific data on the anticancer, anti-inflammatory and antioxidant properties of H. hemerocallidea, H. stellipilis and H. sobolifera chloroform extracts and their active compounds. The hypoxoside and phytosterol contents of the three Hypoxis spp. were determined using TLC, HPLC and GC. H. hemerocallidea and H. sobolifera chloroform extracts contained the highest amounts of hypoxoside and β-sitosterol, respectively. For the anticancer properties, cytotoxicity of the Hypoxis extracts and its purified compounds were determined against the HeLa, HT-29 and MCF-7 cancer cell lines (using MTT), and PBMCs (using CellTiter-Blue®). H. sobolifera had the best cytotoxicity against the three cancer cell lines, whereas H. stellipilis stimulated HeLa and HT-29 cancer cell growth. IC50 values of hypoxoside and rooperol were determined. DNA cell cycle arrest (using PI staining) occurred in the late G1/early S (confirmed by increased p21Waf1/Cip1 expression) and G2/M phases after 15 and 48 hrs, respectively, when treated with Hypoxis extracts and rooperol. H. sobolifera and rooperol activated caspase-3 and -7 (using fluorescently labelled antibodies) in HeLa and HT-29 cancer cells, and caspase-7 in MCF-7 cancer cells after 48 hrs. Annexin V binding to phosphatidylserines in rooperol treated U937 cells confirmed early apoptosis after 15 hrs. The TUNEL assay showed DNA fragmentation in the three cancer cell lines when treated with H. sobolifera and rooperol for 48 hrs. A shift pass the G2/M phase has led to the investigation of endoreduplication, which was confirmed by cell/nucleus size, and anti-apoptotic proteins (Akt, phospho-Akt, phospho-Bcl-2 and p21Waf1/Cip1). U937 cell differentiation to monocyte-macrophages was optimized using PMA and 1,25(OH)2D3, which was confirmed by morphological and biochemical changes. For the anti-inflammatory properties, Hypoxis extracts and rooperol significantly increased NO production in monocyte-macrophages (pre-loaded with DAF-2 DA) and phagocytosis of pHrodoTM E. coli BioParticles®. The treatments had no effect on COX-2 expression in monocyte-macrophages. The phytosterols significantly increased IL-1β and IL-6 secretion xv (using the FlowCytomix Multiplex human Th1/Th2 10plex Kit I) in the PBMCs of one donor. For the antioxidant properties, Hypoxis extracts and rooperol significantly increased ROS production in undifferentiated and differentiated U937 cells, which were pre-loaded with DCFH-DA. Hypoxis extracts and purified compounds had ferric reducing activities, but only rooperol had ferric reducing activities significantly greater than ascorbic acid. β-sitosterol, campesterol and cholesterol significantly increased SOD activity in Chang liver cells, while H. stellipilis, H. sobolifera and rooperol decreased SOD activity. Anticancer, anti-inflammatory and antioxidant properties of the Hypoxis extracts may be attributed to the β-sitosterol content, because Hypoxis chloroform extracts contained very little or no hypoxoside. Unidentified compounds, and synergistic and additive effects of the compounds may have contributed to the biological effects. This study confirms previous reports that rooperol is the active compound. Results provide scientific data on the medicinal properties of one of the most frequently used medicinal plants in South Africa.
- Full Text:
- Date Issued: 2010
- Authors: Boukes, Gerhardt Johannes
- Date: 2010
- Subjects: Potatoes -- Africa , Potatoes -- Therapeutic use , Medicinal plants
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10322 , http://hdl.handle.net/10948/1228 , Potatoes -- Africa , Potatoes -- Therapeutic use , Medicinal plants
- Description: The African potato is used as an African traditional medicine for its nutritional and medicinal properties. Most research has been carried out on H. hemerocallidea, with very little or nothing on other Hypoxis spp. The main aim of this project was to provide scientific data on the anticancer, anti-inflammatory and antioxidant properties of H. hemerocallidea, H. stellipilis and H. sobolifera chloroform extracts and their active compounds. The hypoxoside and phytosterol contents of the three Hypoxis spp. were determined using TLC, HPLC and GC. H. hemerocallidea and H. sobolifera chloroform extracts contained the highest amounts of hypoxoside and β-sitosterol, respectively. For the anticancer properties, cytotoxicity of the Hypoxis extracts and its purified compounds were determined against the HeLa, HT-29 and MCF-7 cancer cell lines (using MTT), and PBMCs (using CellTiter-Blue®). H. sobolifera had the best cytotoxicity against the three cancer cell lines, whereas H. stellipilis stimulated HeLa and HT-29 cancer cell growth. IC50 values of hypoxoside and rooperol were determined. DNA cell cycle arrest (using PI staining) occurred in the late G1/early S (confirmed by increased p21Waf1/Cip1 expression) and G2/M phases after 15 and 48 hrs, respectively, when treated with Hypoxis extracts and rooperol. H. sobolifera and rooperol activated caspase-3 and -7 (using fluorescently labelled antibodies) in HeLa and HT-29 cancer cells, and caspase-7 in MCF-7 cancer cells after 48 hrs. Annexin V binding to phosphatidylserines in rooperol treated U937 cells confirmed early apoptosis after 15 hrs. The TUNEL assay showed DNA fragmentation in the three cancer cell lines when treated with H. sobolifera and rooperol for 48 hrs. A shift pass the G2/M phase has led to the investigation of endoreduplication, which was confirmed by cell/nucleus size, and anti-apoptotic proteins (Akt, phospho-Akt, phospho-Bcl-2 and p21Waf1/Cip1). U937 cell differentiation to monocyte-macrophages was optimized using PMA and 1,25(OH)2D3, which was confirmed by morphological and biochemical changes. For the anti-inflammatory properties, Hypoxis extracts and rooperol significantly increased NO production in monocyte-macrophages (pre-loaded with DAF-2 DA) and phagocytosis of pHrodoTM E. coli BioParticles®. The treatments had no effect on COX-2 expression in monocyte-macrophages. The phytosterols significantly increased IL-1β and IL-6 secretion xv (using the FlowCytomix Multiplex human Th1/Th2 10plex Kit I) in the PBMCs of one donor. For the antioxidant properties, Hypoxis extracts and rooperol significantly increased ROS production in undifferentiated and differentiated U937 cells, which were pre-loaded with DCFH-DA. Hypoxis extracts and purified compounds had ferric reducing activities, but only rooperol had ferric reducing activities significantly greater than ascorbic acid. β-sitosterol, campesterol and cholesterol significantly increased SOD activity in Chang liver cells, while H. stellipilis, H. sobolifera and rooperol decreased SOD activity. Anticancer, anti-inflammatory and antioxidant properties of the Hypoxis extracts may be attributed to the β-sitosterol content, because Hypoxis chloroform extracts contained very little or no hypoxoside. Unidentified compounds, and synergistic and additive effects of the compounds may have contributed to the biological effects. This study confirms previous reports that rooperol is the active compound. Results provide scientific data on the medicinal properties of one of the most frequently used medicinal plants in South Africa.
- Full Text:
- Date Issued: 2010
"I felt that I deserved it" : an Investigation into HIV-related PTSD, traumatic life events, and the personal experiences of living with HIV : a mixed-method study
- Authors: Boulind, Melissa Jane
- Date: 2014
- Subjects: Post-traumatic stress disorder -- Psychological aspects -- Research -- South Africa -- Kwazulu HIV infections -- Psychological aspects -- Research -- South Africa -- Kwazulu HIV-positive persons -- South Africa -- Kwazulu -- Interviews Psychic trauma -- Research Stress (Psychology) -- Research
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3211 , http://hdl.handle.net/10962/d1012172
- Description: There appears to be a growing body of literature focusing on PTSD and HIV-related PTSD (the diagnosis of HIV being the significant traumatic event) amongst HIV-positive samples, but only a few African studies that attempt to estimate the prevalence of PTSD amongst HIV-positive people, and even fewer that attempt to estimate the prevalence of HIV-related PTSD. The systemic review presented in this study is currently fully inclusive and is the most up-to-date available. Estimates of the prevalence of PTSD and HIV-related PTSD in South Africa range from 0.7 to 54.1% and, 4.2 to 40% respectively. The current cross-sectional study made use of a mixed-method approach to investigate traumatic life events, PTSD and HIV-related PTSD within a primary health-care centre in KwaZulu-Natal. The quantitative sample consisted of 159 adults (18-50 years) who were compliant on ARV medication. Using the CIDI-PTSD module, the adapted CIDI-PTSD module for HIV, and IES-R, findings indicated that 62% had reported some kind of traumatic event in their lifetime, with 29.6% of participants meeting the criteria for lifetime PTSD, and 40.9% meeting the criteria for lifetime HIV-related PTSD. Altogether, 57.9% of individuals met the criteria for some form of PTSD (either regular PTSD or HIV-related PTSD), and 12.6% met the criteria for both PTSD and HIV-related PTSD. Of the different categories of traumatic events, interpersonal violence has the highest rate of PTSD, followed by a diagnosis of and living with HIV, and then disaster. Furthermore, the IES-R was compared for its usefulness as a screening measure for PTSD against both the CIDI, but results suggest that it is an inferior screening measure to the PDS. The qualitative study consisted of six participants who were examined using IPA methodology informed by the Ehlers and Clark (2000) Model of trauma. Their experiences revealed experiences of stigma, a number of negative appraisals, negative emotions and coping behaviours. Some of the latter might serve as compensatory mechanisms to avoid negative judgements. Hypervigilance seems to be a feature of ARV-compliance that might confer added vulnerability to PTSD and other anxiety disorders.
- Full Text:
- Date Issued: 2014
- Authors: Boulind, Melissa Jane
- Date: 2014
- Subjects: Post-traumatic stress disorder -- Psychological aspects -- Research -- South Africa -- Kwazulu HIV infections -- Psychological aspects -- Research -- South Africa -- Kwazulu HIV-positive persons -- South Africa -- Kwazulu -- Interviews Psychic trauma -- Research Stress (Psychology) -- Research
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3211 , http://hdl.handle.net/10962/d1012172
- Description: There appears to be a growing body of literature focusing on PTSD and HIV-related PTSD (the diagnosis of HIV being the significant traumatic event) amongst HIV-positive samples, but only a few African studies that attempt to estimate the prevalence of PTSD amongst HIV-positive people, and even fewer that attempt to estimate the prevalence of HIV-related PTSD. The systemic review presented in this study is currently fully inclusive and is the most up-to-date available. Estimates of the prevalence of PTSD and HIV-related PTSD in South Africa range from 0.7 to 54.1% and, 4.2 to 40% respectively. The current cross-sectional study made use of a mixed-method approach to investigate traumatic life events, PTSD and HIV-related PTSD within a primary health-care centre in KwaZulu-Natal. The quantitative sample consisted of 159 adults (18-50 years) who were compliant on ARV medication. Using the CIDI-PTSD module, the adapted CIDI-PTSD module for HIV, and IES-R, findings indicated that 62% had reported some kind of traumatic event in their lifetime, with 29.6% of participants meeting the criteria for lifetime PTSD, and 40.9% meeting the criteria for lifetime HIV-related PTSD. Altogether, 57.9% of individuals met the criteria for some form of PTSD (either regular PTSD or HIV-related PTSD), and 12.6% met the criteria for both PTSD and HIV-related PTSD. Of the different categories of traumatic events, interpersonal violence has the highest rate of PTSD, followed by a diagnosis of and living with HIV, and then disaster. Furthermore, the IES-R was compared for its usefulness as a screening measure for PTSD against both the CIDI, but results suggest that it is an inferior screening measure to the PDS. The qualitative study consisted of six participants who were examined using IPA methodology informed by the Ehlers and Clark (2000) Model of trauma. Their experiences revealed experiences of stigma, a number of negative appraisals, negative emotions and coping behaviours. Some of the latter might serve as compensatory mechanisms to avoid negative judgements. Hypervigilance seems to be a feature of ARV-compliance that might confer added vulnerability to PTSD and other anxiety disorders.
- Full Text:
- Date Issued: 2014
F C Erasmus and the politics of South African defence, 1948-1959
- Authors: Boulter, Roger Stephen
- Date: 1998
- Subjects: Erasmus, F C (Francois Christiaan) South Africa -- Politics and government -- 1948-1961 South Africa -- Armed Forces -- History South Africa -- Military policy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2534 , http://hdl.handle.net/10962/d1002386
- Description: FC Erasmus became South Africa's defence minister in 1948 after two decades as a leading political organiser for the National Party. Although an architect of the Nationalists' post-war election victory he was not considered a minister of the first rank. Erasmus initiated a process of ridding the defence force of officers who he believed were associated with the Smuts government and replacing them with party supporters. As a result the military often lost experienced and talented officers. Erasmus felt that the armed services had been too British in ethos and appearance. He inaugurated tighter regulations on bi-lingualism, reintroduced boer rank titles, launched new uniforms and original medals and decorations, to the acclaim of the volk. His purpose was to have a defence force which was uniquely South African. Many of his policies came under attack not only from the United Party but also groups such as the Torch Commando and the veterans organisations. With the apparent lack of an imminent military threat to the apartheid government Erasmus never received substantial budgetary allocations from finance ministers. The defence force, one without conscription, remained small with largely antiquated equipment for the important air and land forces. However by the decade's end the navy was gradually receiving modern ships under the terms of the Simonstown agreement, which Erasmus had negotiated with Britain. The events of the Sharpeville crisis, just after Erasmus left defence, demonstrated that the armed forces as moulded by the minister were in poor condition to assist the civil power in suppressing disturbances. Overseas Erasmus hoped to increase the acceptability of the Union as a defence partner among Western countries by providing personnel for the Berlin Air Lift and the Korean conflict and promising a contingent for the Middle East. He attempted unsuccessfully to instigate anti-communist alliances for the land and maritime defence of Africa when the European powers were leaving the continent. These actions were primarily to obtain political support for the Union, whose prestige was rapidly decreasing as apartheid became better known. The external initiatives with the exception of the Simonstown naval agreements were not lasting.
- Full Text:
- Date Issued: 1998
- Authors: Boulter, Roger Stephen
- Date: 1998
- Subjects: Erasmus, F C (Francois Christiaan) South Africa -- Politics and government -- 1948-1961 South Africa -- Armed Forces -- History South Africa -- Military policy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2534 , http://hdl.handle.net/10962/d1002386
- Description: FC Erasmus became South Africa's defence minister in 1948 after two decades as a leading political organiser for the National Party. Although an architect of the Nationalists' post-war election victory he was not considered a minister of the first rank. Erasmus initiated a process of ridding the defence force of officers who he believed were associated with the Smuts government and replacing them with party supporters. As a result the military often lost experienced and talented officers. Erasmus felt that the armed services had been too British in ethos and appearance. He inaugurated tighter regulations on bi-lingualism, reintroduced boer rank titles, launched new uniforms and original medals and decorations, to the acclaim of the volk. His purpose was to have a defence force which was uniquely South African. Many of his policies came under attack not only from the United Party but also groups such as the Torch Commando and the veterans organisations. With the apparent lack of an imminent military threat to the apartheid government Erasmus never received substantial budgetary allocations from finance ministers. The defence force, one without conscription, remained small with largely antiquated equipment for the important air and land forces. However by the decade's end the navy was gradually receiving modern ships under the terms of the Simonstown agreement, which Erasmus had negotiated with Britain. The events of the Sharpeville crisis, just after Erasmus left defence, demonstrated that the armed forces as moulded by the minister were in poor condition to assist the civil power in suppressing disturbances. Overseas Erasmus hoped to increase the acceptability of the Union as a defence partner among Western countries by providing personnel for the Berlin Air Lift and the Korean conflict and promising a contingent for the Middle East. He attempted unsuccessfully to instigate anti-communist alliances for the land and maritime defence of Africa when the European powers were leaving the continent. These actions were primarily to obtain political support for the Union, whose prestige was rapidly decreasing as apartheid became better known. The external initiatives with the exception of the Simonstown naval agreements were not lasting.
- Full Text:
- Date Issued: 1998
'n Studie van die houding en gesindheid teenoor spesiale onderwys soos geopenbaar deur 'n groep ouers van spesiale klas-leerlinge in Oos-Kaapland
- Bouwer, Jeremia Cornelius Esias
- Authors: Bouwer, Jeremia Cornelius Esias
- Date: 1979
- Subjects: Special education -- South Africa -- Eastern Cape
- Language: Afrikaans
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1361 , http://hdl.handle.net/10962/d1001427
- Description: Die weerstand wat ouers soms teen Spesiale Onderwys bied, kan stremmend inwerk op leerlinge. Om insig in die gesindheid van ouers van Spesiale Klas-Ieerlinge te verkry, is 'n gewysigde vorm van die Thurston Sentence Completion Form gebruik. Die vorms is deur ouers van leerlinge in 'n aantal Spesiale Klasse in Oos-Kaapland voltooi en die response is in positiewe en negatiewe reaksies ingedeel. Ook is elke item ontleed. Daar is tot die gevolgtrekking gekom dat die meeste ouers tog weI positief ingesteld is teenoor Spesiale Onderwys en inderdaad erkenning verleen aan die werk wat in die klasse gedoen word. Die behoefte aan 'n nouer skakeling tussen die betrokke ouers en die skole het duidelik na vore gekom
- Full Text:
- Date Issued: 1979
- Authors: Bouwer, Jeremia Cornelius Esias
- Date: 1979
- Subjects: Special education -- South Africa -- Eastern Cape
- Language: Afrikaans
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1361 , http://hdl.handle.net/10962/d1001427
- Description: Die weerstand wat ouers soms teen Spesiale Onderwys bied, kan stremmend inwerk op leerlinge. Om insig in die gesindheid van ouers van Spesiale Klas-Ieerlinge te verkry, is 'n gewysigde vorm van die Thurston Sentence Completion Form gebruik. Die vorms is deur ouers van leerlinge in 'n aantal Spesiale Klasse in Oos-Kaapland voltooi en die response is in positiewe en negatiewe reaksies ingedeel. Ook is elke item ontleed. Daar is tot die gevolgtrekking gekom dat die meeste ouers tog weI positief ingesteld is teenoor Spesiale Onderwys en inderdaad erkenning verleen aan die werk wat in die klasse gedoen word. Die behoefte aan 'n nouer skakeling tussen die betrokke ouers en die skole het duidelik na vore gekom
- Full Text:
- Date Issued: 1979
Novel aspects of platinum-amine coordination compounds: their chemistry and anticancer application
- Authors: Bouwer, Yolanda
- Date: 2008
- Subjects: Coordination compounds , Platinum compounds , Antineoplastic agents
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10444 , http://hdl.handle.net/10948/d1021052
- Description: The aim in this thesis, was to synthesize novel platinum coordination compounds, in order to develop compounds with improved anticancer action which could lead to an improved understanding of the mechanism by which they operate and at the same time, improve synthetic methods for their products. The initial work included the development of a novel synthetic method for 1R,2R-diaminocyclohexaneoxalato-platinum(II) (oxaliplatin), by using an essentially non-aqueous solvent medium and direct ligand exchange at elevated temperatures. This was done by a study of the kinetics of the reaction in a variety of conditions; such as relative reagent concentrations and ratios as well as solvent mixtures. An effective method was developed which could be applied industrially. An international patent was taken out on this method. Various amine complexes of platinum(II) were synthesized using chloro, bromo and oxalato groups as leaving groups. The non-leaving groups were selected having certain specific characteristics in mind. Novel mononitroplatinum(IV) complexes were synthesized, mostly with oxalato leaving groups. One of these in particular, had excellent anticancer behaviour. Another trichloromononitro complex was also synthesized with very good anticancer properties. Two international patents were filed for the latter two compounds. As far as possible, all compounds were studied by spectrometric, chromatographic and thermal methods. They were also tested against 3 cancer cell lines namely cervical (Hela), Colon (HT29) and Breast (MCF7) cancer cells.
- Full Text:
- Date Issued: 2008
- Authors: Bouwer, Yolanda
- Date: 2008
- Subjects: Coordination compounds , Platinum compounds , Antineoplastic agents
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10444 , http://hdl.handle.net/10948/d1021052
- Description: The aim in this thesis, was to synthesize novel platinum coordination compounds, in order to develop compounds with improved anticancer action which could lead to an improved understanding of the mechanism by which they operate and at the same time, improve synthetic methods for their products. The initial work included the development of a novel synthetic method for 1R,2R-diaminocyclohexaneoxalato-platinum(II) (oxaliplatin), by using an essentially non-aqueous solvent medium and direct ligand exchange at elevated temperatures. This was done by a study of the kinetics of the reaction in a variety of conditions; such as relative reagent concentrations and ratios as well as solvent mixtures. An effective method was developed which could be applied industrially. An international patent was taken out on this method. Various amine complexes of platinum(II) were synthesized using chloro, bromo and oxalato groups as leaving groups. The non-leaving groups were selected having certain specific characteristics in mind. Novel mononitroplatinum(IV) complexes were synthesized, mostly with oxalato leaving groups. One of these in particular, had excellent anticancer behaviour. Another trichloromononitro complex was also synthesized with very good anticancer properties. Two international patents were filed for the latter two compounds. As far as possible, all compounds were studied by spectrometric, chromatographic and thermal methods. They were also tested against 3 cancer cell lines namely cervical (Hela), Colon (HT29) and Breast (MCF7) cancer cells.
- Full Text:
- Date Issued: 2008
Towards a norm of compliance in recreational fisheries
- Authors: Bova, Christopher S
- Date: 2019
- Subjects: Fishing -- Management -- South Africa , Fishery law and legislation -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/95909 , vital:31213
- Description: The activity of fishing can be traced back to prehistoric times. However, only in the last century has there been a focus on the management of fisheries. Fishery regulations are tools used by resource managers with the aim of protecting the long-term sustainability of fishery resources. Although there is an overwhelming amount of evidence demonstrating the decline of fisheries, non-compliance with these regulations by fishers continues to manifest, which can exacerbate the negative ecological impacts of fisheries. Popular methods towards the measurement of noncompliance in fisheries derived from previous human dimensions literature may be flawed. Theories on improving compliance behaviour have typically relied on theory, which has at times proved paradoxical. Addressing the issues of non-compliance within a fishery of interest requires measuring the levels of non-compliance within the fishery and determining the relevant sociopsychological drivers behind the non-compliant behaviour. The data collection methods used during these assessments are limited in human dimensions research and are often case and context specific, requiring researchers to identify which approach is most practical for the specific fishery of interest. By identifying relevant behavioural drivers of non-compliance, a more effective approach aimed at improving compliance can be tailored. The recreational marine-based shore fishery (MBSF) in South Africa is not impervious to noncomplaint behaviour. In fact, it has been estimated to have relatively high rates of non-compliance. This high level of non-compliance makes the South African MBSF a unique and optimal context in which to undertake research that aims to formulate a framework towards compliance assessments and that develops a suitable approach for improving compliance rates. Using surveys to obtain compliance data can provide a range of details about violators, however they are susceptible to social desirability bias (SDB). Choosing the best method for controlling SDB required an assessment of existing methods for doing so. In this first part of the study, only fishers who were covertly observed breaking the rules were surveyed, using one of three methods for reducing SDB, to ground-truth the responses. Ground-truthing was done to determine which method would be most effective for a large-scale study within the same fishery. Of the methods used, which include the direct questioning method (DQM), the random response technique (RRT) and the ballot box method (BBM), all contained some level of SDB. However, the BBM provided a significantly higher level of response accuracy (79.6% ± 11.9) than the DQM (46.5% ± 14.9) and the RRT (44.3% ± 12.5). Random-stratified roving creel compliance surveys that employed the BBM were then undertaken at various locations along South Africa’s coastline to estimate current rates of non-compliance, and the face-to-face results were compared to results from an identical online survey to determine the suitability of online surveys as a replacement. The results indicated that online surveys only represent a subgroup of the fisher population within the MBSF, suggesting that face-to-face survey methods are required to obtain a more comprehensive sample and a more robust estimate of noncompliance. The results, based on 453 face-to-face surveys, showed a high level of overall self-reported noncompliance (48.3%) within the fishery. Responses to Likert scale survey questions on various aspects of the fishery, including angler motivations for fishing, were then modelled to test the relationship between the anglers’ responses and their compliance behaviour. In the South African MBSF context, the most significant behavioural drivers behind non-compliance related to normative concepts. Specifically, the poor perceptions of management and value-based legitimacy as well as low levels of moral obligation to adhere to the regulations appeared to contribute most to the observed non-compliant behaviour. Angler motivations for fishing also played a significant role in determining the compliance behaviour of anglers, with those fishing for food being more likely to violate regulations. In most countries, regardless of economic context, interventions to improve recreational fishery compliance have been developed around the instrumental concept. However, these findings suggest that for recreational fisheries, managers would do well to evaluate the impact of normative concepts on compliance and to design interventions aimed at addressing these. In the case of the South African MBSF, interventions that address angler perceptions of legitimacy and aim to correct misperceptions about social norms of compliance may provide a more practical and cost- effective method for improving poor compliance behaviour.
- Full Text:
- Date Issued: 2019
- Authors: Bova, Christopher S
- Date: 2019
- Subjects: Fishing -- Management -- South Africa , Fishery law and legislation -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/95909 , vital:31213
- Description: The activity of fishing can be traced back to prehistoric times. However, only in the last century has there been a focus on the management of fisheries. Fishery regulations are tools used by resource managers with the aim of protecting the long-term sustainability of fishery resources. Although there is an overwhelming amount of evidence demonstrating the decline of fisheries, non-compliance with these regulations by fishers continues to manifest, which can exacerbate the negative ecological impacts of fisheries. Popular methods towards the measurement of noncompliance in fisheries derived from previous human dimensions literature may be flawed. Theories on improving compliance behaviour have typically relied on theory, which has at times proved paradoxical. Addressing the issues of non-compliance within a fishery of interest requires measuring the levels of non-compliance within the fishery and determining the relevant sociopsychological drivers behind the non-compliant behaviour. The data collection methods used during these assessments are limited in human dimensions research and are often case and context specific, requiring researchers to identify which approach is most practical for the specific fishery of interest. By identifying relevant behavioural drivers of non-compliance, a more effective approach aimed at improving compliance can be tailored. The recreational marine-based shore fishery (MBSF) in South Africa is not impervious to noncomplaint behaviour. In fact, it has been estimated to have relatively high rates of non-compliance. This high level of non-compliance makes the South African MBSF a unique and optimal context in which to undertake research that aims to formulate a framework towards compliance assessments and that develops a suitable approach for improving compliance rates. Using surveys to obtain compliance data can provide a range of details about violators, however they are susceptible to social desirability bias (SDB). Choosing the best method for controlling SDB required an assessment of existing methods for doing so. In this first part of the study, only fishers who were covertly observed breaking the rules were surveyed, using one of three methods for reducing SDB, to ground-truth the responses. Ground-truthing was done to determine which method would be most effective for a large-scale study within the same fishery. Of the methods used, which include the direct questioning method (DQM), the random response technique (RRT) and the ballot box method (BBM), all contained some level of SDB. However, the BBM provided a significantly higher level of response accuracy (79.6% ± 11.9) than the DQM (46.5% ± 14.9) and the RRT (44.3% ± 12.5). Random-stratified roving creel compliance surveys that employed the BBM were then undertaken at various locations along South Africa’s coastline to estimate current rates of non-compliance, and the face-to-face results were compared to results from an identical online survey to determine the suitability of online surveys as a replacement. The results indicated that online surveys only represent a subgroup of the fisher population within the MBSF, suggesting that face-to-face survey methods are required to obtain a more comprehensive sample and a more robust estimate of noncompliance. The results, based on 453 face-to-face surveys, showed a high level of overall self-reported noncompliance (48.3%) within the fishery. Responses to Likert scale survey questions on various aspects of the fishery, including angler motivations for fishing, were then modelled to test the relationship between the anglers’ responses and their compliance behaviour. In the South African MBSF context, the most significant behavioural drivers behind non-compliance related to normative concepts. Specifically, the poor perceptions of management and value-based legitimacy as well as low levels of moral obligation to adhere to the regulations appeared to contribute most to the observed non-compliant behaviour. Angler motivations for fishing also played a significant role in determining the compliance behaviour of anglers, with those fishing for food being more likely to violate regulations. In most countries, regardless of economic context, interventions to improve recreational fishery compliance have been developed around the instrumental concept. However, these findings suggest that for recreational fisheries, managers would do well to evaluate the impact of normative concepts on compliance and to design interventions aimed at addressing these. In the case of the South African MBSF, interventions that address angler perceptions of legitimacy and aim to correct misperceptions about social norms of compliance may provide a more practical and cost- effective method for improving poor compliance behaviour.
- Full Text:
- Date Issued: 2019
Feeding ecology of the cichlid fish Sarotherodon Mossambicus in Lake Sibaya, KwaZulu
- Authors: Bowen, Stephen H
- Date: 1977
- Subjects: Cichlids -- Ecology , Fishes -- Ecology -- South Africa -- KwaZulu-Natal -- Sibaya, Lake
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5837 , http://hdl.handle.net/10962/d1009688 , Cichlids -- Ecology , Fishes -- Ecology -- South Africa -- KwaZulu-Natal -- Sibaya, Lake
- Description: The feeding of the cichlid fish Sarotherodon mossambicus in Lake Sibaya, KwaZulu, was studied in relation to various biotic and abiotic features of the l ake environment from January, 1973 to July, 1975. The primary goal of the study was to determine the cause of stunting and poor condition of adults in this population. Juvenile and adult S. mossambicus feed on a mixture of detritus, bacteria and diatoms that occurs as a flocculent layer on sand substrates throughout the lake. Concentrated gastric acid, commonly at pH values of 1.5 and lower, lyses diatoms and bacteria which are subsequently digested in the intestine. This is the first report of digestion of bacteria by a fish, and the nutritional significance of the finding is discussed. Juveniles feed predominantly on shallow sand terraces found along the margin of much of the lake, while adults usually feed in offshore waters at depths of 3 m and greater. Benthic floc from feeding areas of juveniles and adults have similar concentrations of organic matter, total carbohydrate, soluble carbohydrate and calories, but differ markedly in respect to diatom and protein concentration. Diatom concentrations are generally high in terrace floc but are consistently low in floc from deep water. Protein concentration of benthic floc decreases with increasing depth from 0 - 5 m. Partial correlation analysis shows that protein and diatom concentrations have no correlation independent. of their common relationship to depth, and the evidence implicates detrital bacteria as the primary source of protein in benthic floc. Probable causes of the observed distributions of diatoms and protein are discussed. The protein content of benthic floc profoundly influences its nutritional value. A comparison with available data on animal nutrition shows that the ratio of digestible protein to digestible energy in floc in the shallows is high enough that this food resource would be expected to support good growth, but the ratio for deep water floc is so low that it would be expected to result in conspicuous malnutrition. Thus, inadequate dietary protein is identified as the principal cause of stunting and poor condition of adult S· mossambicus in Lake Sibaya; It is argued that the ratio of digestible protein to digestible calories can be expected to determine the food value of particulate organic matter that includes amorphous detritus in other ecosystems. Despite stunting and poor condition of adults, S. mossambicus are abundant in Lake Sibaya. The precocious breeding of this population is discussed as an adaptation that allows it to maximize reproductive output given the limited resources available to adults. Juvenile S. mossambicus perform daily movements from deep water onto the terraces where they feed and then back into deep water. During periods of relatively low lake level when terrace waters were usually less than 1.5 m deep (1-73 to 1-74), juveniles were present on the terrace throughout daylight hours. At relatively high lake levels (7-74 to 8-75), juveniles were present on the terraces for only about five hours following sunset. Periods of heavy wave action interrupt feeding activity and result in reduced numbers of fish in terrace waters. The possible roles of predator avoidance and temperature in determination of daily feeding behavior are discussed. Daily energy assimilation by juveniles, estimated by a field technique, is approximately 115 cal per g fish dry weight.
- Full Text:
- Date Issued: 1977
- Authors: Bowen, Stephen H
- Date: 1977
- Subjects: Cichlids -- Ecology , Fishes -- Ecology -- South Africa -- KwaZulu-Natal -- Sibaya, Lake
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5837 , http://hdl.handle.net/10962/d1009688 , Cichlids -- Ecology , Fishes -- Ecology -- South Africa -- KwaZulu-Natal -- Sibaya, Lake
- Description: The feeding of the cichlid fish Sarotherodon mossambicus in Lake Sibaya, KwaZulu, was studied in relation to various biotic and abiotic features of the l ake environment from January, 1973 to July, 1975. The primary goal of the study was to determine the cause of stunting and poor condition of adults in this population. Juvenile and adult S. mossambicus feed on a mixture of detritus, bacteria and diatoms that occurs as a flocculent layer on sand substrates throughout the lake. Concentrated gastric acid, commonly at pH values of 1.5 and lower, lyses diatoms and bacteria which are subsequently digested in the intestine. This is the first report of digestion of bacteria by a fish, and the nutritional significance of the finding is discussed. Juveniles feed predominantly on shallow sand terraces found along the margin of much of the lake, while adults usually feed in offshore waters at depths of 3 m and greater. Benthic floc from feeding areas of juveniles and adults have similar concentrations of organic matter, total carbohydrate, soluble carbohydrate and calories, but differ markedly in respect to diatom and protein concentration. Diatom concentrations are generally high in terrace floc but are consistently low in floc from deep water. Protein concentration of benthic floc decreases with increasing depth from 0 - 5 m. Partial correlation analysis shows that protein and diatom concentrations have no correlation independent. of their common relationship to depth, and the evidence implicates detrital bacteria as the primary source of protein in benthic floc. Probable causes of the observed distributions of diatoms and protein are discussed. The protein content of benthic floc profoundly influences its nutritional value. A comparison with available data on animal nutrition shows that the ratio of digestible protein to digestible energy in floc in the shallows is high enough that this food resource would be expected to support good growth, but the ratio for deep water floc is so low that it would be expected to result in conspicuous malnutrition. Thus, inadequate dietary protein is identified as the principal cause of stunting and poor condition of adult S· mossambicus in Lake Sibaya; It is argued that the ratio of digestible protein to digestible calories can be expected to determine the food value of particulate organic matter that includes amorphous detritus in other ecosystems. Despite stunting and poor condition of adults, S. mossambicus are abundant in Lake Sibaya. The precocious breeding of this population is discussed as an adaptation that allows it to maximize reproductive output given the limited resources available to adults. Juvenile S. mossambicus perform daily movements from deep water onto the terraces where they feed and then back into deep water. During periods of relatively low lake level when terrace waters were usually less than 1.5 m deep (1-73 to 1-74), juveniles were present on the terrace throughout daylight hours. At relatively high lake levels (7-74 to 8-75), juveniles were present on the terraces for only about five hours following sunset. Periods of heavy wave action interrupt feeding activity and result in reduced numbers of fish in terrace waters. The possible roles of predator avoidance and temperature in determination of daily feeding behavior are discussed. Daily energy assimilation by juveniles, estimated by a field technique, is approximately 115 cal per g fish dry weight.
- Full Text:
- Date Issued: 1977
A historic-hermeneutic critique of luthiery with specific reference to selected South African guiter builders
- Authors: Bower, Rudi
- Date: 2008
- Subjects: Guitar -- Construction , Guitar -- History
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:8512 , http://hdl.handle.net/10948/779 , Guitar -- Construction , Guitar -- History
- Description: This study uses a general historical overview of luthiery that provides the reader with a basic understanding of construction techniques and terminology as a point of departure. From the outset the lack of consensus over an ideal or desired construction technique is highlighted. However, Torres is credited with the establishing of a perceived Spanish tradition of guitar construction and acknowledged as the “father” of the modern guitar. This will serve as a basic framework in which a discussion of six prominent past and present international luthiers can occur. These luthiers, namely Antonio de Torres, Hermann Hauser, Robert Bouchet, Daniel Friederich, Jose Romanillos and Greg Smallman are included in this study by virtue of their influence on the South African luthiers that are featured here. It is noted that these six luthiers, with the exception of Greg Smallman, all adhere to the “Spanish tradition” of guitar construction. Smallman can be considered a foremost proponent of a more recent “modern” school of guitar construction characterized by various innovative construction techniques. These are a result of new demands placed on the guitar as performance instrument because of larger concert venues and more collaboration with different instruments, resulting in a need for a stronger tone and more projection and penetration in sound. These two “poles” of luthiery are then manifested in the discussion on the seven featured South African luthiers. Alistair Thompson, Colin Cleveland, Mervyn Davis, Garth Pickard, Marc Maingard, Rodney Stedall and Hans van den Berg are discussed with special mention made of the features of their instruments, woods used and thoughts on luthiery, against the backdrop of their biographies. The four South African luthiers who build within the “Spanish tradition” (Pickard, Maingard, Stedall and Van den Berg) are distinguished from the three who build outside this so-called tradition (Thompson, Cleveland, Davis). South African luthiery is therefore shown to be an accurate microcosm of luthiery in global terms with styles of construction ranging from very “traditional” to very “modern”. The critical reflection on the information contained in this study appears in the form of a hermeneutic critique on luthiery that occurs within the parameters of the thought of two prominent hermeneutic thinkers, Martin Heidegger and his student, Hans-Georg Gadamer. It is shown that the collaboration that often occurs between guitar makers and performers can be related back to Gadamer and his analysis of Heidegger’s notion of the the hermeneutic circle. It is also argued that luthiery as practiced by the international and South African luthiers featured in this study can be seen both as art and technology in ancient Greek terms in that they are both a mode of revealing. Finally, it is shown how luthiery in its entirety can be viewed as a tradition and that different luthiers respond and add to this tradition in various ways.
- Full Text:
- Date Issued: 2008
- Authors: Bower, Rudi
- Date: 2008
- Subjects: Guitar -- Construction , Guitar -- History
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:8512 , http://hdl.handle.net/10948/779 , Guitar -- Construction , Guitar -- History
- Description: This study uses a general historical overview of luthiery that provides the reader with a basic understanding of construction techniques and terminology as a point of departure. From the outset the lack of consensus over an ideal or desired construction technique is highlighted. However, Torres is credited with the establishing of a perceived Spanish tradition of guitar construction and acknowledged as the “father” of the modern guitar. This will serve as a basic framework in which a discussion of six prominent past and present international luthiers can occur. These luthiers, namely Antonio de Torres, Hermann Hauser, Robert Bouchet, Daniel Friederich, Jose Romanillos and Greg Smallman are included in this study by virtue of their influence on the South African luthiers that are featured here. It is noted that these six luthiers, with the exception of Greg Smallman, all adhere to the “Spanish tradition” of guitar construction. Smallman can be considered a foremost proponent of a more recent “modern” school of guitar construction characterized by various innovative construction techniques. These are a result of new demands placed on the guitar as performance instrument because of larger concert venues and more collaboration with different instruments, resulting in a need for a stronger tone and more projection and penetration in sound. These two “poles” of luthiery are then manifested in the discussion on the seven featured South African luthiers. Alistair Thompson, Colin Cleveland, Mervyn Davis, Garth Pickard, Marc Maingard, Rodney Stedall and Hans van den Berg are discussed with special mention made of the features of their instruments, woods used and thoughts on luthiery, against the backdrop of their biographies. The four South African luthiers who build within the “Spanish tradition” (Pickard, Maingard, Stedall and Van den Berg) are distinguished from the three who build outside this so-called tradition (Thompson, Cleveland, Davis). South African luthiery is therefore shown to be an accurate microcosm of luthiery in global terms with styles of construction ranging from very “traditional” to very “modern”. The critical reflection on the information contained in this study appears in the form of a hermeneutic critique on luthiery that occurs within the parameters of the thought of two prominent hermeneutic thinkers, Martin Heidegger and his student, Hans-Georg Gadamer. It is shown that the collaboration that often occurs between guitar makers and performers can be related back to Gadamer and his analysis of Heidegger’s notion of the the hermeneutic circle. It is also argued that luthiery as practiced by the international and South African luthiers featured in this study can be seen both as art and technology in ancient Greek terms in that they are both a mode of revealing. Finally, it is shown how luthiery in its entirety can be viewed as a tradition and that different luthiers respond and add to this tradition in various ways.
- Full Text:
- Date Issued: 2008
Antecedents and influence of the union-management relationship on employee relationships in the automotive, component and metal industries in the Nelson Mandela Bay Metropole
- Authors: Bowler, Jennifer
- Date: 2019
- Subjects: Industrial relations, South Africa , Psychology, Industrial Work environment Industrial relations Labor unions
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/37150 , vital:34126
- Description: South Africa is consistently portrayed as having uncooperative union-management relationships which negatively impact competitiveness. However, the post-1994 labour legislation was specifically crafted with the intention of positioning the adversarial wealth distribution phase of the union-management relationship within centralised bargaining forums and promoting cooperative relationships within workplaces. The purpose of this study was to investigate whether within the South Africa context of global competitiveness, the employment relations institutions of centralised and decentralised collective bargaining, employee participation and involvement, in the context of organisational justice, have contributed to management, shop stewards and production employees developing effective1 collective and individual employment relationships positively associated with competitive individual and company performance. The targeted population were companies within the Nelson Mandela Metropolitan Area that were registered with one of the four bargaining councils, Automotive (NBF), Automotive component (MIBCO), New Tyre (NTMIBC) and Metal and Engineering (MEIBC). In addition, since the National Union of Metal Workers was the dominant union in all four of these councils, an additional criterion for potential participation was at least one NUMSA shop steward. Fourteen companies agreed to participate. In total 63 shop stewards, 82 managers and 660 production employees were surveyed using self-administered questionnaires. The results of the study identified that the three major stakeholders hold significantly different perceptions regarding the quality of the management-shop steward relationship, with management the most positive and production employees the least. Further, investigating the factors that influence the perceptions that management and shop stewards have of their relationship, it was identified that for management the most influential factor was their beliefs regarding the interdependent nature of the relationship. For the shop stewards the situation was more nuanced with beliefs regarding interdependence, the perceptions of shop steward-management climate within the bargaining council, satisfaction 1 Definition of an effective employment relationship: An effective employment relationship is one in which the parties successfully resolve issues arising from their conflicting interests and successfully pursue joint gains where they share common interests (Kochan & Katz, 1988) with bargaining council agreements and workplace human resource practices and procedural fairness all contributing factors to the quality of the shop steward-management relationship. The model tested for production employees investigated the relationship between the factors human resource practices, procedural fairness, the standardisation of work, the employees’ perception of the shop steward-management relationship and the relationship of the employees with both their supervisor and the organisation. The primary finding was that the perception that the production employees held regarding the shop steward-management relationship fully mediated the employees’ relationship with the organisation and partially mediated that with the supervisor. These findings confirm the mediating position occupied by shop stewards within unionised companies and without derogating the importance of supervisory-employee relationships, indicated the central importance of the management-shop steward relations in forging strong employee-manager and employee-organisational bonds. While the original purpose of the study included investigating the link between the key employment relationships, namely, shop steward-management, employee-supervisor and employee-organisation relationships, and company competitiveness, unfortunately due to the limited number of companies that participated, it was not possible to test a company level model that included company performance. However, tentative support was found for relationships between the shop steward-management relationship and company performance. This remains an area for further study.
- Full Text:
- Date Issued: 2019
- Authors: Bowler, Jennifer
- Date: 2019
- Subjects: Industrial relations, South Africa , Psychology, Industrial Work environment Industrial relations Labor unions
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/37150 , vital:34126
- Description: South Africa is consistently portrayed as having uncooperative union-management relationships which negatively impact competitiveness. However, the post-1994 labour legislation was specifically crafted with the intention of positioning the adversarial wealth distribution phase of the union-management relationship within centralised bargaining forums and promoting cooperative relationships within workplaces. The purpose of this study was to investigate whether within the South Africa context of global competitiveness, the employment relations institutions of centralised and decentralised collective bargaining, employee participation and involvement, in the context of organisational justice, have contributed to management, shop stewards and production employees developing effective1 collective and individual employment relationships positively associated with competitive individual and company performance. The targeted population were companies within the Nelson Mandela Metropolitan Area that were registered with one of the four bargaining councils, Automotive (NBF), Automotive component (MIBCO), New Tyre (NTMIBC) and Metal and Engineering (MEIBC). In addition, since the National Union of Metal Workers was the dominant union in all four of these councils, an additional criterion for potential participation was at least one NUMSA shop steward. Fourteen companies agreed to participate. In total 63 shop stewards, 82 managers and 660 production employees were surveyed using self-administered questionnaires. The results of the study identified that the three major stakeholders hold significantly different perceptions regarding the quality of the management-shop steward relationship, with management the most positive and production employees the least. Further, investigating the factors that influence the perceptions that management and shop stewards have of their relationship, it was identified that for management the most influential factor was their beliefs regarding the interdependent nature of the relationship. For the shop stewards the situation was more nuanced with beliefs regarding interdependence, the perceptions of shop steward-management climate within the bargaining council, satisfaction 1 Definition of an effective employment relationship: An effective employment relationship is one in which the parties successfully resolve issues arising from their conflicting interests and successfully pursue joint gains where they share common interests (Kochan & Katz, 1988) with bargaining council agreements and workplace human resource practices and procedural fairness all contributing factors to the quality of the shop steward-management relationship. The model tested for production employees investigated the relationship between the factors human resource practices, procedural fairness, the standardisation of work, the employees’ perception of the shop steward-management relationship and the relationship of the employees with both their supervisor and the organisation. The primary finding was that the perception that the production employees held regarding the shop steward-management relationship fully mediated the employees’ relationship with the organisation and partially mediated that with the supervisor. These findings confirm the mediating position occupied by shop stewards within unionised companies and without derogating the importance of supervisory-employee relationships, indicated the central importance of the management-shop steward relations in forging strong employee-manager and employee-organisational bonds. While the original purpose of the study included investigating the link between the key employment relationships, namely, shop steward-management, employee-supervisor and employee-organisation relationships, and company competitiveness, unfortunately due to the limited number of companies that participated, it was not possible to test a company level model that included company performance. However, tentative support was found for relationships between the shop steward-management relationship and company performance. This remains an area for further study.
- Full Text:
- Date Issued: 2019
An investigation of IgE regulation by recombinant soluble IgE receptors and co-receptors in human cell culture models
- Authors: Bowles, Sandra Lyn
- Date: 2010
- Subjects: Immunoglobulin E , Allergy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10321 , http://hdl.handle.net/10948/1231 , Immunoglobulin E , Allergy
- Description: Type I hypersensitivities are mediated by the IgE antibody. The effector functions and synthesis of IgE result from interactions with a network of proteins that include a high affinity (FcRIα) and a low affinity (CD23, FcRII) Fc receptor in conjunction with the B lymphocyte receptor, CD21. CD23 is a multifunctional type II transmembrane protein that binds its known ligands through its ectodomain either as a membrane-bound or soluble receptor generated in vivo by specific proteolytic cleavages. IgE production is primarily regulated by interactions between IgE, CD23 and CD21. Despite its importance for development of strategies to limit hypersensitivity, precise information about the molecular interactions remains limited. During this study, I engineered, expressed and purified from bacteria three soluble human CD23 fragments that are normally formed in vivo and shed from the cell surface (1) derCD23, amino acids 156-298 (2) sCD23, amino acids 150-321 and (3) the entire ectodomain, exCD23, amino acids 48-321 to examine the comparative binding of recombinant human CD21 SCR 1-2 and native human IgE to these fragments. Gel filtration HPLC revealed that derCD23 and sCD23 were monomeric whereas exCD23 assembled as a heterogeneous mixture that included trimers and monomers. At the concentrations utilized, CD23 fragments sCD23 and exCD23 bound CD21 with similar affinity, whereas interaction between derCD23 and CD21 was minimal when analyzed by surface plasmon resonance (SPR) spectroscopy. These findings suggest that penultimate “tail” amino acids between 298 and 321 stabilize CD21 attachment, although it cannot be ruled out, the region between Met 150 and Ser 156 may also play a role in binding CD21 SCR 1-2. In contrast, there is a progressive increment in the affinity of soluble fragments (exCD23>sCD23>derCD23) for IgE, upon increasing length of the proximal CD23 “stalk” domain. These findings highlight the differences in both the structural basis and affinity of the three physiological fragments of human CD23 for the ligands CD21 and IgE and underscore the complexity of CD23-mediated regulatory networks. It was found that B-cells only make up ~5% of the PBMC population, and that these cells were able to be activated, via STAT-6 phosphorylation, to enter class switch recombination (CSR) by the addition of switch factors (IL-4 and anti-CD40). Titration experiments dictated that 25 ng/mL of CD23 was the most efficient concentration to up-regulate IgE synthesis in PBMCs; furthermore, soluble CD23 proteins were incubated with PBMCs in the presence and absence of CD21 SCR 1-2 to investigate the effect that these recombinant proteins have on IgE synthesis. Results showed that the influence of recombinant proteins (both CD23 and CD21) on IgE synthesis was slight. It was shown that while derCD23 had no significant effect, monomeric sCD23 down-regulated, and the mixture of monomeric and oligomeric exCD23 up-regulated IgE synthesis. On addition of CD21 SCR 1-2 to the cells switched and treated with soluble CD23, it was found that in both cases for sCD23 and exCD23, IgE synthesis was increased, while for derCD23, there was no noticeable difference in IgE synthesis. This confirmed previous data showing the lack of binding between derCD23 and CD21 SCR 1-2. The exact binding site for CD21 on the CD23 molecule is unknown, and incompletely represented in the NMR and crystal structures. It is thought that CD21 binds to the C-terminal tail section, not present in derCD23. It is therefore likely that only a negative-feedback mechanism operates with derCD23 to regulate IgE synthesis. Further investigation of the binding of CD23 fragments to SCR 5-8 of CD21 and the effect of this on IgE synthesis may lead to a potential therapeutic role for derCD23 in the treatment of allergic disease. Data accumulated in this study suggests that investigating the modulation of oligomeric state and thus the activity of soluble CD23 fragments may be important in the construction of new regulators of IgE synthesis.
- Full Text:
- Date Issued: 2010
- Authors: Bowles, Sandra Lyn
- Date: 2010
- Subjects: Immunoglobulin E , Allergy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10321 , http://hdl.handle.net/10948/1231 , Immunoglobulin E , Allergy
- Description: Type I hypersensitivities are mediated by the IgE antibody. The effector functions and synthesis of IgE result from interactions with a network of proteins that include a high affinity (FcRIα) and a low affinity (CD23, FcRII) Fc receptor in conjunction with the B lymphocyte receptor, CD21. CD23 is a multifunctional type II transmembrane protein that binds its known ligands through its ectodomain either as a membrane-bound or soluble receptor generated in vivo by specific proteolytic cleavages. IgE production is primarily regulated by interactions between IgE, CD23 and CD21. Despite its importance for development of strategies to limit hypersensitivity, precise information about the molecular interactions remains limited. During this study, I engineered, expressed and purified from bacteria three soluble human CD23 fragments that are normally formed in vivo and shed from the cell surface (1) derCD23, amino acids 156-298 (2) sCD23, amino acids 150-321 and (3) the entire ectodomain, exCD23, amino acids 48-321 to examine the comparative binding of recombinant human CD21 SCR 1-2 and native human IgE to these fragments. Gel filtration HPLC revealed that derCD23 and sCD23 were monomeric whereas exCD23 assembled as a heterogeneous mixture that included trimers and monomers. At the concentrations utilized, CD23 fragments sCD23 and exCD23 bound CD21 with similar affinity, whereas interaction between derCD23 and CD21 was minimal when analyzed by surface plasmon resonance (SPR) spectroscopy. These findings suggest that penultimate “tail” amino acids between 298 and 321 stabilize CD21 attachment, although it cannot be ruled out, the region between Met 150 and Ser 156 may also play a role in binding CD21 SCR 1-2. In contrast, there is a progressive increment in the affinity of soluble fragments (exCD23>sCD23>derCD23) for IgE, upon increasing length of the proximal CD23 “stalk” domain. These findings highlight the differences in both the structural basis and affinity of the three physiological fragments of human CD23 for the ligands CD21 and IgE and underscore the complexity of CD23-mediated regulatory networks. It was found that B-cells only make up ~5% of the PBMC population, and that these cells were able to be activated, via STAT-6 phosphorylation, to enter class switch recombination (CSR) by the addition of switch factors (IL-4 and anti-CD40). Titration experiments dictated that 25 ng/mL of CD23 was the most efficient concentration to up-regulate IgE synthesis in PBMCs; furthermore, soluble CD23 proteins were incubated with PBMCs in the presence and absence of CD21 SCR 1-2 to investigate the effect that these recombinant proteins have on IgE synthesis. Results showed that the influence of recombinant proteins (both CD23 and CD21) on IgE synthesis was slight. It was shown that while derCD23 had no significant effect, monomeric sCD23 down-regulated, and the mixture of monomeric and oligomeric exCD23 up-regulated IgE synthesis. On addition of CD21 SCR 1-2 to the cells switched and treated with soluble CD23, it was found that in both cases for sCD23 and exCD23, IgE synthesis was increased, while for derCD23, there was no noticeable difference in IgE synthesis. This confirmed previous data showing the lack of binding between derCD23 and CD21 SCR 1-2. The exact binding site for CD21 on the CD23 molecule is unknown, and incompletely represented in the NMR and crystal structures. It is thought that CD21 binds to the C-terminal tail section, not present in derCD23. It is therefore likely that only a negative-feedback mechanism operates with derCD23 to regulate IgE synthesis. Further investigation of the binding of CD23 fragments to SCR 5-8 of CD21 and the effect of this on IgE synthesis may lead to a potential therapeutic role for derCD23 in the treatment of allergic disease. Data accumulated in this study suggests that investigating the modulation of oligomeric state and thus the activity of soluble CD23 fragments may be important in the construction of new regulators of IgE synthesis.
- Full Text:
- Date Issued: 2010
Evaluation of a plant-herbivore system in determining potential efficacy of a candidate biological control agent, cornops aquaticum for water hyacinth, eichhornia crassipes
- Authors: Bownes, Angela
- Date: 2009
- Subjects: Water hyacinth -- Control -- South Africa , Eichhornia crassipedes , Pontederiaceae , Grasshoppers , Biological pest control agents -- South Africa , Weeds -- Biological control -- South Africa , Invasive plants -- Biological control -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5687 , http://hdl.handle.net/10962/d1005373
- Description: Water hyacinth, Eichhornia crassipes Mart. Solms-Laubach (Pontederiaceae), a freefloating aquatic macrophyte of Neotropical origin, was introduced into South Africa as an ornamental aquarium plant in the early 1900’s. By the 1970’s it had reached pest proportions in dams and rivers around the country. Due to the sustainability, cost efficiency and low environmental risk associated with biological control, this has been a widely used method in an attempt to reduce infestations to below the threshold where they cause economic and ecological damage. To date, five arthropod and one pathogen biocontrol agents have been introduced for the control of water hyacinth but their impact has been variable. It is believed that their efficacy is hampered by the presence of highly eutrophic systems in South Africa in which plant growth is prolific and the negative effects of herbivory are therefore mitigated. It is for these reasons that new, potentially more damaging biocontrol agents are being considered for release. The water hyacinth grasshopper, Cornops aquaticum Brüner (Orthoptera: Acrididae), which is native to South America and Mexico, was brought into quarantine in Pretoria, South Africa in 1995. Although the grasshopper was identified as one of the most damaging insects associated with water hyacinth in its native range, it has not been considered as a biocontrol agent for water hyacinth anywhere else in the world. After extensive host-range testing which revealed it to be safe for release, a release permit for this candidate agent was issued in 2007. However, host specificity testing is no longer considered to be the only important component of pre-release screening of candidate biocontrol agents. Investigating biological and ecological aspects of the plant-herbivore system that will assist in determination of potential establishment, efficacy and the ability to build up good populations in the recipient environment are some of the important factors. This thesis is a pre-release evaluation of C. aquaticum to determine whether it is sufficiently damaging to water hyacinth to warrant its release. It investigated interactions between the grasshopper and water hyacinth under a range of nutrient conditions found in South African water bodies as well as the impact of the grasshopper on the competitive performance of water hyacinth. Both plant growth rates and the response of water hyacinth to herbivory by the grasshopper were influenced by nutrient availability to the plants. The ability of water hyacinth to compensate for loss of tissue through herbivory was greater under eutrophic nutrient conditions. However, a negative linear relationship was found between grasshopper biomass and water hyacinth performance parameters such as biomass accumulation and leaf production, even under eutrophic conditions. Water hyacinth’s compensatory ability in terms of its potential to mitigate to detrimental effects of insect feeding was dependent on the amount of damage caused by herbivory by the grasshopper. Plant biomass and the competitive ability of water hyacinth in relation to another freefloating aquatic weed species were reduced by C. aquaticum under eutrophic nutrient conditions, in a short space of time. It was also found that grasshopper feeding and characteristics related to their population dynamics such as fecundity and survival were significantly influenced by water nutrient availability and that environmental nutrient availability will influence the control potential of this species should it be released in South Africa. Cornops aquaticum shows promise as a biocontrol agent for water hyacinth but additional factors that were not investigated in this study such as compatibility with the South African climate and the current water hyacinth biocontrol agents need to be combined with these data to make a decision on its release. Possible management options for this species if it is to be introduced into South Africa are discussed.
- Full Text:
- Date Issued: 2009
- Authors: Bownes, Angela
- Date: 2009
- Subjects: Water hyacinth -- Control -- South Africa , Eichhornia crassipedes , Pontederiaceae , Grasshoppers , Biological pest control agents -- South Africa , Weeds -- Biological control -- South Africa , Invasive plants -- Biological control -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5687 , http://hdl.handle.net/10962/d1005373
- Description: Water hyacinth, Eichhornia crassipes Mart. Solms-Laubach (Pontederiaceae), a freefloating aquatic macrophyte of Neotropical origin, was introduced into South Africa as an ornamental aquarium plant in the early 1900’s. By the 1970’s it had reached pest proportions in dams and rivers around the country. Due to the sustainability, cost efficiency and low environmental risk associated with biological control, this has been a widely used method in an attempt to reduce infestations to below the threshold where they cause economic and ecological damage. To date, five arthropod and one pathogen biocontrol agents have been introduced for the control of water hyacinth but their impact has been variable. It is believed that their efficacy is hampered by the presence of highly eutrophic systems in South Africa in which plant growth is prolific and the negative effects of herbivory are therefore mitigated. It is for these reasons that new, potentially more damaging biocontrol agents are being considered for release. The water hyacinth grasshopper, Cornops aquaticum Brüner (Orthoptera: Acrididae), which is native to South America and Mexico, was brought into quarantine in Pretoria, South Africa in 1995. Although the grasshopper was identified as one of the most damaging insects associated with water hyacinth in its native range, it has not been considered as a biocontrol agent for water hyacinth anywhere else in the world. After extensive host-range testing which revealed it to be safe for release, a release permit for this candidate agent was issued in 2007. However, host specificity testing is no longer considered to be the only important component of pre-release screening of candidate biocontrol agents. Investigating biological and ecological aspects of the plant-herbivore system that will assist in determination of potential establishment, efficacy and the ability to build up good populations in the recipient environment are some of the important factors. This thesis is a pre-release evaluation of C. aquaticum to determine whether it is sufficiently damaging to water hyacinth to warrant its release. It investigated interactions between the grasshopper and water hyacinth under a range of nutrient conditions found in South African water bodies as well as the impact of the grasshopper on the competitive performance of water hyacinth. Both plant growth rates and the response of water hyacinth to herbivory by the grasshopper were influenced by nutrient availability to the plants. The ability of water hyacinth to compensate for loss of tissue through herbivory was greater under eutrophic nutrient conditions. However, a negative linear relationship was found between grasshopper biomass and water hyacinth performance parameters such as biomass accumulation and leaf production, even under eutrophic conditions. Water hyacinth’s compensatory ability in terms of its potential to mitigate to detrimental effects of insect feeding was dependent on the amount of damage caused by herbivory by the grasshopper. Plant biomass and the competitive ability of water hyacinth in relation to another freefloating aquatic weed species were reduced by C. aquaticum under eutrophic nutrient conditions, in a short space of time. It was also found that grasshopper feeding and characteristics related to their population dynamics such as fecundity and survival were significantly influenced by water nutrient availability and that environmental nutrient availability will influence the control potential of this species should it be released in South Africa. Cornops aquaticum shows promise as a biocontrol agent for water hyacinth but additional factors that were not investigated in this study such as compatibility with the South African climate and the current water hyacinth biocontrol agents need to be combined with these data to make a decision on its release. Possible management options for this species if it is to be introduced into South Africa are discussed.
- Full Text:
- Date Issued: 2009
Habitat segregation in competing species of intertidal mussels in South Africa
- Authors: Bownes, Sarah
- Date: 2006
- Subjects: Mussels -- South Africa Mussels -- Growth Mussels -- Habitat -- South Africa Mussels -- Larvae Perna -- South Africa Mytilus galloprovincialis -- South Africa Choromytilus meridionalis -- South Africa Mytilidae -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5706 , http://hdl.handle.net/10962/d1005392
- Description: Mytilus galloprovincialis is invasive on rocky shores on the west coast of South Africa where it has become the dominant intertidal mussel. The success of this species on the west coast and its superior competitive abilities, have led to concern that it may become invasive on the south coast at the expense of the indigenous mussel Perna perna. On shores where these species co-occur, there appears to be habitat segregation among zones occupied by mussels. M.galloprovincialis dominates the high-shore and P.perna the low-shore, with a mixed zone at mid-shore level. This study examined the factors responsible for these differences in distribution and abundance. The study was conducted in Plettenberg Bay and Tsitsikamma (70km apart) on the south coast of South Africa. Each site included two randomly selected locations (300-400m apart). A third mussel species, Choromytilus meridionalis, is found in large numbers at the sand/rock interface at one location in Plettenberg Bay. Aspects of settlement, recruitment, growth and mortality of juvenile and adult mussels were examined at different tidal heights at each site. Quantitative analysis of mussel population structure at these sites supported the initial observation of vertical habitat segregation. Post-larvae were identified to species and this was confirmed using hinge morphology and mitochondrial DNA analysis. Size at settlement was determined for each species to differentiate between primary and secondary settlement. Adult distribution of C.meridionalis was primarily determined by settlement, which was highly selective in this species. Settlement, recruitment and growth of P.perna decreased with increasing tidal height, while post-settlement mortality and adult mortality increased higher upshore. Thus all aspects of P.perna’s life history contribute to the adult distribution of this species. Presumably, the abundance of P.perna on the high-shore is initially limited by recruitment while those that survive remain prone to elimination throughout adulthood. M.galloprovincialis displayed the same patterns of settlement and recruitment as P.perna. However, post-settlement mortality in this species was consistently low in the low and high zones. Juvenile growth also decreased upshore, suggesting that M.galloprovincialis may be able to maintain high densities on the high-shore through the persistence of successive settlements of slow-growing individuals. The low cover of M.galloprovincialis on the lowshore appeared to be determined by adult interactions. M.galloprovincialis experienced significantly higher adult mortality rates than P.perna in this zone. There were seasonal variations in the competitive advantages enjoyed by each species through growth, recruitment or mortality on the low-shore. In summer, P.perna had higher recruitment rates, faster growth and lower mortality rates, while M.galloprovincialis had slightly higher recruitment rates and faster growth rates in winter. P.perna is a warm water species while M.galloprovincialis thrives on the cold-temperate west coast of South Africa. Therefore both species appear to be at the edge of their optimal temperature regimes on the south coast, which may explain the seasonal advantages of each. Nevertheless, P.perna has maintained spatial dominance on the low-shore suggesting that it may ultimately be the winner in competition between these species. M.galloprovincialis appears to have a refuge from competition with P.perna on the high-shore due to its greater tolerance of desiccation stress, while being competitively excluded from the low-shore. Warm water temperatures coupled with poor recruitment rates at most sites may limit the success of M.galloprovincialis on this coast.
- Full Text:
- Date Issued: 2006
- Authors: Bownes, Sarah
- Date: 2006
- Subjects: Mussels -- South Africa Mussels -- Growth Mussels -- Habitat -- South Africa Mussels -- Larvae Perna -- South Africa Mytilus galloprovincialis -- South Africa Choromytilus meridionalis -- South Africa Mytilidae -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5706 , http://hdl.handle.net/10962/d1005392
- Description: Mytilus galloprovincialis is invasive on rocky shores on the west coast of South Africa where it has become the dominant intertidal mussel. The success of this species on the west coast and its superior competitive abilities, have led to concern that it may become invasive on the south coast at the expense of the indigenous mussel Perna perna. On shores where these species co-occur, there appears to be habitat segregation among zones occupied by mussels. M.galloprovincialis dominates the high-shore and P.perna the low-shore, with a mixed zone at mid-shore level. This study examined the factors responsible for these differences in distribution and abundance. The study was conducted in Plettenberg Bay and Tsitsikamma (70km apart) on the south coast of South Africa. Each site included two randomly selected locations (300-400m apart). A third mussel species, Choromytilus meridionalis, is found in large numbers at the sand/rock interface at one location in Plettenberg Bay. Aspects of settlement, recruitment, growth and mortality of juvenile and adult mussels were examined at different tidal heights at each site. Quantitative analysis of mussel population structure at these sites supported the initial observation of vertical habitat segregation. Post-larvae were identified to species and this was confirmed using hinge morphology and mitochondrial DNA analysis. Size at settlement was determined for each species to differentiate between primary and secondary settlement. Adult distribution of C.meridionalis was primarily determined by settlement, which was highly selective in this species. Settlement, recruitment and growth of P.perna decreased with increasing tidal height, while post-settlement mortality and adult mortality increased higher upshore. Thus all aspects of P.perna’s life history contribute to the adult distribution of this species. Presumably, the abundance of P.perna on the high-shore is initially limited by recruitment while those that survive remain prone to elimination throughout adulthood. M.galloprovincialis displayed the same patterns of settlement and recruitment as P.perna. However, post-settlement mortality in this species was consistently low in the low and high zones. Juvenile growth also decreased upshore, suggesting that M.galloprovincialis may be able to maintain high densities on the high-shore through the persistence of successive settlements of slow-growing individuals. The low cover of M.galloprovincialis on the lowshore appeared to be determined by adult interactions. M.galloprovincialis experienced significantly higher adult mortality rates than P.perna in this zone. There were seasonal variations in the competitive advantages enjoyed by each species through growth, recruitment or mortality on the low-shore. In summer, P.perna had higher recruitment rates, faster growth and lower mortality rates, while M.galloprovincialis had slightly higher recruitment rates and faster growth rates in winter. P.perna is a warm water species while M.galloprovincialis thrives on the cold-temperate west coast of South Africa. Therefore both species appear to be at the edge of their optimal temperature regimes on the south coast, which may explain the seasonal advantages of each. Nevertheless, P.perna has maintained spatial dominance on the low-shore suggesting that it may ultimately be the winner in competition between these species. M.galloprovincialis appears to have a refuge from competition with P.perna on the high-shore due to its greater tolerance of desiccation stress, while being competitively excluded from the low-shore. Warm water temperatures coupled with poor recruitment rates at most sites may limit the success of M.galloprovincialis on this coast.
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- Date Issued: 2006