A critical analysis of community participation at the primary level of the health system in Goromonzi District, Zimbabwe
- Authors: Gondo, Rachel
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: http://hdl.handle.net/10962/1454 , vital:20059
- Description: The adoption of the primary health care approach by Zimbabwe in 1980 signalled the government’s intention to consolidate the gains of the liberation struggle by providing equitable health for all citizens regardless of race and class. This approach frames community participation as central to the design and implementation of responsive health systems. Having earned international recognition for its pro-poor policies in the social sectors after independence in 1980, the Zimbabwean government over the last three decades has overseen a progressive decline in the provision of health services and near collapse of the health sector. Participation of communities, whether in the form of organised groups or as unorganised members of the public, is argued to be an important pillar in the effective performance of a health system. There has been extensive research conducted on Zimbabwe’s implementation of primary health care in light of health status, accessibility and health services uptake. A few studies have been undertaken to demonstrate that the participation of communities in the health system is an important factor in improving the effectiveness of the health system in Zimbabwe. This thesis analyses the existing mechanisms for community participation in the health system in Zimbabwe and brings out multiple perspectives on the underlying contradictions, tensions and processes at play between policy and practice. This thesis makes a contribution to the growing number of studies on participation in health by offering an empirically rich critical analysis of community participation in the health system in one ward located in Goromonzi District in Zimbabwe. In examining the structural and procedural forms of the health system, insights concerning the nature and form of community participation in primary health care are brought to the fore. The thesis concludes that the ways in which community participation takes place in the health system in Zimbabwe is influenced by a number of socio-economic, political and societal factors and this in turn has a bearing on how health policy expresses itself in practice.
- Full Text:
- Date Issued: 2016
- Authors: Gondo, Rachel
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: http://hdl.handle.net/10962/1454 , vital:20059
- Description: The adoption of the primary health care approach by Zimbabwe in 1980 signalled the government’s intention to consolidate the gains of the liberation struggle by providing equitable health for all citizens regardless of race and class. This approach frames community participation as central to the design and implementation of responsive health systems. Having earned international recognition for its pro-poor policies in the social sectors after independence in 1980, the Zimbabwean government over the last three decades has overseen a progressive decline in the provision of health services and near collapse of the health sector. Participation of communities, whether in the form of organised groups or as unorganised members of the public, is argued to be an important pillar in the effective performance of a health system. There has been extensive research conducted on Zimbabwe’s implementation of primary health care in light of health status, accessibility and health services uptake. A few studies have been undertaken to demonstrate that the participation of communities in the health system is an important factor in improving the effectiveness of the health system in Zimbabwe. This thesis analyses the existing mechanisms for community participation in the health system in Zimbabwe and brings out multiple perspectives on the underlying contradictions, tensions and processes at play between policy and practice. This thesis makes a contribution to the growing number of studies on participation in health by offering an empirically rich critical analysis of community participation in the health system in one ward located in Goromonzi District in Zimbabwe. In examining the structural and procedural forms of the health system, insights concerning the nature and form of community participation in primary health care are brought to the fore. The thesis concludes that the ways in which community participation takes place in the health system in Zimbabwe is influenced by a number of socio-economic, political and societal factors and this in turn has a bearing on how health policy expresses itself in practice.
- Full Text:
- Date Issued: 2016
A neural network based ionospheric model for the bottomside electron density profile over Grahamstown, South Africa
- Authors: McKinnell, L A
- Date: 2003
- Subjects: Neural networks (Computer science) Ionospheric electron density -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5477 , http://hdl.handle.net/10962/d1005262
- Description: This thesis describes the development and application of a neural network based ionospheric model for the bottomside electron density profile over Grahamstown, South Africa. All available ionospheric data from the archives of the Grahamstown (33.32ºS, 26.50ºE) ionospheric station were used for training neural networks (NNs) to predict the parameters required to produce the final profile. Inputs to the model, called the LAM model, are day number, hour, and measures of solar and magnetic activity. The output is a mathematical description of the bottomside electron density profile for that particular input set. The two main ionospheric layers, the E and F layers, are predicted separately and then combined at the final stage. For each layer, NNs have been trained to predict the individual ionospheric characteristics and coefficients that were required to describe the layer profile. NNs were also applied to the task of determining the hours between which an E layer is measurable by a groundbased ionosonde and the probability of the existence of an F1 layer. The F1 probability NN is innovative in that it provides information on the existence of the F1 layer as well as the probability of that layer being in a L-condition state - the state where an F1 layer is present on an ionogram but it is not possible to record any F1 parameters. In the event of an L-condition state being predicted as probable, an L algorithm has been designed to alter the shape of the profile to reflect this state. A smoothing algorithm has been implemented to remove discontinuities at the F1-F2 boundary and ensure that the profile represents realistic ionospheric behaviour in the F1 region. Tests show that the LAM model is more successful at predicting Grahamstown electron density profiles for a particular set of inputs than the International Reference Ionosphere (IRI). It is anticipated that the LAM model will be used as a tool in the pin-pointing of hostile HF transmitters, known as single-site location.
- Full Text:
- Date Issued: 2003
- Authors: McKinnell, L A
- Date: 2003
- Subjects: Neural networks (Computer science) Ionospheric electron density -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5477 , http://hdl.handle.net/10962/d1005262
- Description: This thesis describes the development and application of a neural network based ionospheric model for the bottomside electron density profile over Grahamstown, South Africa. All available ionospheric data from the archives of the Grahamstown (33.32ºS, 26.50ºE) ionospheric station were used for training neural networks (NNs) to predict the parameters required to produce the final profile. Inputs to the model, called the LAM model, are day number, hour, and measures of solar and magnetic activity. The output is a mathematical description of the bottomside electron density profile for that particular input set. The two main ionospheric layers, the E and F layers, are predicted separately and then combined at the final stage. For each layer, NNs have been trained to predict the individual ionospheric characteristics and coefficients that were required to describe the layer profile. NNs were also applied to the task of determining the hours between which an E layer is measurable by a groundbased ionosonde and the probability of the existence of an F1 layer. The F1 probability NN is innovative in that it provides information on the existence of the F1 layer as well as the probability of that layer being in a L-condition state - the state where an F1 layer is present on an ionogram but it is not possible to record any F1 parameters. In the event of an L-condition state being predicted as probable, an L algorithm has been designed to alter the shape of the profile to reflect this state. A smoothing algorithm has been implemented to remove discontinuities at the F1-F2 boundary and ensure that the profile represents realistic ionospheric behaviour in the F1 region. Tests show that the LAM model is more successful at predicting Grahamstown electron density profiles for a particular set of inputs than the International Reference Ionosphere (IRI). It is anticipated that the LAM model will be used as a tool in the pin-pointing of hostile HF transmitters, known as single-site location.
- Full Text:
- Date Issued: 2003
African traditional medicines-antiretroviral drug interactions: the effect of African potato (Hypoxis hemerocallidea) on the pharmacokinetics of efavirenz in humans
- Authors: Mogatle, Seloi
- Date: 2009
- Subjects: Potatoes -- Africa Potatoes -- Therapeutic use Medicinal plants Traditional medicine AIDS (Disease) -- Treatment HIV infections -- Drug therapy Drug interactions Antiretroviral agents Pharmacokinetics Hypoxidaceae -- Therapeutic use High performance liquid chromatography
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3773 , http://hdl.handle.net/10962/d1003251
- Description: African Potato (Hypoxis hemerocallidea), (AP) is an African traditional medicine (TM) that is commonly used for various nutritional/medicinal purposes and also by people infected with the human immuno deficiency virus HIV and AIDS patients as an immune booster. The use of AP has also been recommended by the former Minister of Health of South Africa for use by HIV positive people. The main phytochemical component of AP is a norlignan glucoside, hypoxoside, and other relatively minor components have also been reported. A recent in vitro study reported the effects of AP extracts, hypoxoside and rooperol (the metabolite of hypoxoside) on human metabolic enzymes such as the cytochrome P450 (CYP450) group of enzymes and also on the transporter protein, p-glycoprotein (P-gp). This research focussed on investigating the clinical significance of those in vitro effects on the pharmacokinetics of efavirenz (EFV) in humans. EFV was chosen as the substrate drug because it is in first-line regimen of treatment of HIV/AIDS in South Africa, and also has been reported to be a substrate for the specific CYP isozymes, 3A4 and 2B6, in common with APs metabolic involvement with 3A4. A high performance liquid chromatography method with ultra-violet detection (HPLC-UV) for the quantitative determination of EFV in plasma was developed and successfully validated according to international standards with good reproducibility, accuracy, recovery, linear response and requisite sensitivity. The preparation of the plasma samples for analysis was effected by using a simple and rapid precipitation method, and the mobile phase consisted of readily available solvents. EFV in plasma samples was found to be stable under the relevant storage conditions studied. The oral dose of AP, administered as a freshly prepared traditional decoction, was standardised based on the hypoxoside content, and the quality of all the AP decoctions was analysed immediately prior to administration, using a validated HPLC-UV method. A single dose, two-phase sequential study was conducted over a period of 31 days in 10 healthy volunteers. The clinical study was approved by the Rhodes University Ethical Standards Committee, and all the participants agreed to the conditions of the study by giving their informed consent. On day 1 of the study, human subjects were administered a 600 mg EFV tablet and blood samples were collected before dosing and at various intervals over a period of 48 hr post dosing. From day 16, a traditionally prepared AP decoction was administered daily at a standardized dose of 15 mg/kg/day per subject until day 30. On day 29, volunteers were administered a single 600 mg dose of EFV as was done on day 1. Plasma samples were harvested immediately after blood sample collection and frozen at -80 ºC until assayed. Geometric mean ratios of relevant pharmacokinetic parameters, Cmax (maximum plasma concentration achieved following dosing) and AUC0-48 (area under the curve of a plot of drug plasma concentrations versus time representing the extent of absorption) of EFV before and after co-administration of 14 successive daily doses of AP were compared and evaluated to determine whether an interaction had occurred. All subjects completed the study and the geometric mean ratios of Cmax and AUC0-48 were 97.30 and 102.82 with corresponding 90% confidence intervals (CIs) of 78.81-120.14% and 89.04-118.80%, respectively. Whereas the acceptance criteria for the ratios of the AUCs fell within the preset 90% CIs indicating no interaction, the Cmax ratios fell outside the limits. Although the protocol was developed in accordance with the United States of America Food & Drug Administration’s Guidance for Drug Interactions, a priori stating that both criteria need to fall within the acceptance limits to indicate no interaction, an argument is presented to waive the Cmax requirement for the declaration of an interaction. As a result, the pharmacokinetic data generated during this study indicated that the effect of AP on the pharmacokinetics of EFV is not clinically significant. Hence, co-administration of AP is unlikely to affect the clinical use of EFV. In summary the objectives of this project were: 1. To develop and validate a suitable HPLC-UV method for the quantitative determination of EFV in plasma. 2. To perform a mini-validation of the determination of hypoxoside for use as a marker in the quality control and standardisation of AP decoctions. 3. To conduct a clinical interaction study in order to determine whether AP affects the pharmacokinetics of EFV following concurrent administration. 4. To apply the validated HPLC-UV method to determine plasma concentrations of EFV in plasma of human subjects. 5. To use appropriate statistical methods and treatments such as a non-compartmental pharmacokinetic analysis to determine the occurrence of an interaction.
- Full Text:
- Date Issued: 2009
- Authors: Mogatle, Seloi
- Date: 2009
- Subjects: Potatoes -- Africa Potatoes -- Therapeutic use Medicinal plants Traditional medicine AIDS (Disease) -- Treatment HIV infections -- Drug therapy Drug interactions Antiretroviral agents Pharmacokinetics Hypoxidaceae -- Therapeutic use High performance liquid chromatography
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3773 , http://hdl.handle.net/10962/d1003251
- Description: African Potato (Hypoxis hemerocallidea), (AP) is an African traditional medicine (TM) that is commonly used for various nutritional/medicinal purposes and also by people infected with the human immuno deficiency virus HIV and AIDS patients as an immune booster. The use of AP has also been recommended by the former Minister of Health of South Africa for use by HIV positive people. The main phytochemical component of AP is a norlignan glucoside, hypoxoside, and other relatively minor components have also been reported. A recent in vitro study reported the effects of AP extracts, hypoxoside and rooperol (the metabolite of hypoxoside) on human metabolic enzymes such as the cytochrome P450 (CYP450) group of enzymes and also on the transporter protein, p-glycoprotein (P-gp). This research focussed on investigating the clinical significance of those in vitro effects on the pharmacokinetics of efavirenz (EFV) in humans. EFV was chosen as the substrate drug because it is in first-line regimen of treatment of HIV/AIDS in South Africa, and also has been reported to be a substrate for the specific CYP isozymes, 3A4 and 2B6, in common with APs metabolic involvement with 3A4. A high performance liquid chromatography method with ultra-violet detection (HPLC-UV) for the quantitative determination of EFV in plasma was developed and successfully validated according to international standards with good reproducibility, accuracy, recovery, linear response and requisite sensitivity. The preparation of the plasma samples for analysis was effected by using a simple and rapid precipitation method, and the mobile phase consisted of readily available solvents. EFV in plasma samples was found to be stable under the relevant storage conditions studied. The oral dose of AP, administered as a freshly prepared traditional decoction, was standardised based on the hypoxoside content, and the quality of all the AP decoctions was analysed immediately prior to administration, using a validated HPLC-UV method. A single dose, two-phase sequential study was conducted over a period of 31 days in 10 healthy volunteers. The clinical study was approved by the Rhodes University Ethical Standards Committee, and all the participants agreed to the conditions of the study by giving their informed consent. On day 1 of the study, human subjects were administered a 600 mg EFV tablet and blood samples were collected before dosing and at various intervals over a period of 48 hr post dosing. From day 16, a traditionally prepared AP decoction was administered daily at a standardized dose of 15 mg/kg/day per subject until day 30. On day 29, volunteers were administered a single 600 mg dose of EFV as was done on day 1. Plasma samples were harvested immediately after blood sample collection and frozen at -80 ºC until assayed. Geometric mean ratios of relevant pharmacokinetic parameters, Cmax (maximum plasma concentration achieved following dosing) and AUC0-48 (area under the curve of a plot of drug plasma concentrations versus time representing the extent of absorption) of EFV before and after co-administration of 14 successive daily doses of AP were compared and evaluated to determine whether an interaction had occurred. All subjects completed the study and the geometric mean ratios of Cmax and AUC0-48 were 97.30 and 102.82 with corresponding 90% confidence intervals (CIs) of 78.81-120.14% and 89.04-118.80%, respectively. Whereas the acceptance criteria for the ratios of the AUCs fell within the preset 90% CIs indicating no interaction, the Cmax ratios fell outside the limits. Although the protocol was developed in accordance with the United States of America Food & Drug Administration’s Guidance for Drug Interactions, a priori stating that both criteria need to fall within the acceptance limits to indicate no interaction, an argument is presented to waive the Cmax requirement for the declaration of an interaction. As a result, the pharmacokinetic data generated during this study indicated that the effect of AP on the pharmacokinetics of EFV is not clinically significant. Hence, co-administration of AP is unlikely to affect the clinical use of EFV. In summary the objectives of this project were: 1. To develop and validate a suitable HPLC-UV method for the quantitative determination of EFV in plasma. 2. To perform a mini-validation of the determination of hypoxoside for use as a marker in the quality control and standardisation of AP decoctions. 3. To conduct a clinical interaction study in order to determine whether AP affects the pharmacokinetics of EFV following concurrent administration. 4. To apply the validated HPLC-UV method to determine plasma concentrations of EFV in plasma of human subjects. 5. To use appropriate statistical methods and treatments such as a non-compartmental pharmacokinetic analysis to determine the occurrence of an interaction.
- Full Text:
- Date Issued: 2009
An investigation into how grade 9 learners make sense of prior everyday knowledge and practical learning through exploring tooth decay problems in Onangalo village: a case study
- Authors: Asino, Tomas
- Date: 2013
- Subjects: Dental caries -- Study and teaching (Secondary) -- Namibia -- Omusati -- Case studies Science -- Study and teaching (Secondary) -- Namibia -- Omusati -- Case studies Experiential learning -- Namibia -- Omusati -- Case studies Educational change -- Namibia Curriculum planning -- Namibia Education, Secondary -- Namibia -- Omusati
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1406 , http://hdl.handle.net/10962/d1001986
- Description: The main goal of this study was to investigate how grade 9 learners make sense of prior everyday knowledge and practical learning through exploring tooth decay problems in their local context. The study was conducted at a deep rural Junior Secondary School situated in Onangalo Village, Tsandi constituency in Omusati political region, northern part of Namibia. My research was triggered by the transformation in the Namibian curriculum, which now recognizes a need to contextualize science and make it relevant to the learners’ everyday life experiences. An interpretivist paradigm informed this study. Within this paradigm, a qualitative case study approach was employed. The unit of analysis was the various activities undertaken by my grade 9 learners with a view to make meaning of prior everyday knowledge and practical investigations in chemistry. A variety of data generating techniques were used in this study, namely, brainstorming and discussion sessions, questionnaires, practical activities with worksheets and semi-structured interviews. A video recorder was used to capture events throughout. Analytical categories emerged as a result of a coding system called pawing. From the analytical categories, analytical statements were formulated. The generated data was validated by a critical friend who was a Life Science teacher at the same school at which I did this study. Further validation was done through learners watching the video recordings and through focus group interviews. Methodological triangulation was also used to validate the data. The study revealed that the use of learners’ prior everyday knowledge and experiences in teaching and learning promoted active learners’ participation and enhanced meaning making. Thus, the study recommends the adoption of well-structured science lessons which take into consideration learners’ prior everyday knowledge. The study recommends that these science lessons be used in conjunction with practical activities to promote active learner engagement and conceptual development. Despite the benefits of integrating learners’ prior everyday knowledge during teaching and learning, the study however also revealed some challenges such as limited time and difficulties of English language proficiency amongst learners.
- Full Text:
- Date Issued: 2013
- Authors: Asino, Tomas
- Date: 2013
- Subjects: Dental caries -- Study and teaching (Secondary) -- Namibia -- Omusati -- Case studies Science -- Study and teaching (Secondary) -- Namibia -- Omusati -- Case studies Experiential learning -- Namibia -- Omusati -- Case studies Educational change -- Namibia Curriculum planning -- Namibia Education, Secondary -- Namibia -- Omusati
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1406 , http://hdl.handle.net/10962/d1001986
- Description: The main goal of this study was to investigate how grade 9 learners make sense of prior everyday knowledge and practical learning through exploring tooth decay problems in their local context. The study was conducted at a deep rural Junior Secondary School situated in Onangalo Village, Tsandi constituency in Omusati political region, northern part of Namibia. My research was triggered by the transformation in the Namibian curriculum, which now recognizes a need to contextualize science and make it relevant to the learners’ everyday life experiences. An interpretivist paradigm informed this study. Within this paradigm, a qualitative case study approach was employed. The unit of analysis was the various activities undertaken by my grade 9 learners with a view to make meaning of prior everyday knowledge and practical investigations in chemistry. A variety of data generating techniques were used in this study, namely, brainstorming and discussion sessions, questionnaires, practical activities with worksheets and semi-structured interviews. A video recorder was used to capture events throughout. Analytical categories emerged as a result of a coding system called pawing. From the analytical categories, analytical statements were formulated. The generated data was validated by a critical friend who was a Life Science teacher at the same school at which I did this study. Further validation was done through learners watching the video recordings and through focus group interviews. Methodological triangulation was also used to validate the data. The study revealed that the use of learners’ prior everyday knowledge and experiences in teaching and learning promoted active learners’ participation and enhanced meaning making. Thus, the study recommends the adoption of well-structured science lessons which take into consideration learners’ prior everyday knowledge. The study recommends that these science lessons be used in conjunction with practical activities to promote active learner engagement and conceptual development. Despite the benefits of integrating learners’ prior everyday knowledge during teaching and learning, the study however also revealed some challenges such as limited time and difficulties of English language proficiency amongst learners.
- Full Text:
- Date Issued: 2013
An organisation development intervention in an Anglican church theological seminary in Southern Africa
- Authors: Chinganga, Percy
- Date: 2013-08-08
- Subjects: College of the Transfiguration (Grahamstown, South Africa) Organizational change -- Church of England -- Africa, Southern Leadership -- Religious aspects -- Christianity -- Africa, Southern Church management -- Church of England -- Africa, Southern
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1959 , http://hdl.handle.net/10962/d1008377
- Description: "Organisation development is a planned, systematic process in which applied behavioral science principles and practices are introduced into ongoing organisations toward the goal of increasing individual and organisational effectiveness. " [French and Bell] This study describes and analyses the implementation of Organisation Development (OD) to an Anglican Church theological seminary, The College of the Transfiguration (Cott), in the Anglican Church of the Province of Southern Africa (ACSA). The origins of OD are business related, emerging in the late 1950s and early 1960s. Over the years, and recently in South Africa, OD has been applied in educational change initiatives. Unlike more traditional change strategies, OD promotes collaboration in organisational change processes through the inclusive participation of all stakeholders. This study is unique in the sense that OD is applied to an Anglican Church theological institution in Southern Africa. The goal of theological institutions, particularly Cot!, is to "form, inform and transform" (Cot! Prospectus, 2011) those who feel called to ordained ministry. Personal experience in this practice has confirmed that organisational emphasis is placed more on product than process; on results rather than the leadership and management of the organisation. This study was an attempt to introduce a process of planned change to such an organisational context. OD was introduced to The College of the Transfiguration in the form of action research using the Survey Data Feedback (SDF) strategy. Data gathered was interpreted and analysed, followed by action planning and implementation of agreed plans. The process had a positive impact on both stakeholders and the organisation despite the challenges associated with the unpredictable world of organisations. Ultimately, I propose tentative recommendations which could help Cott and other educational institutions to achieve long-term improvement in organisational leadership and management.
- Full Text:
- Authors: Chinganga, Percy
- Date: 2013-08-08
- Subjects: College of the Transfiguration (Grahamstown, South Africa) Organizational change -- Church of England -- Africa, Southern Leadership -- Religious aspects -- Christianity -- Africa, Southern Church management -- Church of England -- Africa, Southern
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1959 , http://hdl.handle.net/10962/d1008377
- Description: "Organisation development is a planned, systematic process in which applied behavioral science principles and practices are introduced into ongoing organisations toward the goal of increasing individual and organisational effectiveness. " [French and Bell] This study describes and analyses the implementation of Organisation Development (OD) to an Anglican Church theological seminary, The College of the Transfiguration (Cott), in the Anglican Church of the Province of Southern Africa (ACSA). The origins of OD are business related, emerging in the late 1950s and early 1960s. Over the years, and recently in South Africa, OD has been applied in educational change initiatives. Unlike more traditional change strategies, OD promotes collaboration in organisational change processes through the inclusive participation of all stakeholders. This study is unique in the sense that OD is applied to an Anglican Church theological institution in Southern Africa. The goal of theological institutions, particularly Cot!, is to "form, inform and transform" (Cot! Prospectus, 2011) those who feel called to ordained ministry. Personal experience in this practice has confirmed that organisational emphasis is placed more on product than process; on results rather than the leadership and management of the organisation. This study was an attempt to introduce a process of planned change to such an organisational context. OD was introduced to The College of the Transfiguration in the form of action research using the Survey Data Feedback (SDF) strategy. Data gathered was interpreted and analysed, followed by action planning and implementation of agreed plans. The process had a positive impact on both stakeholders and the organisation despite the challenges associated with the unpredictable world of organisations. Ultimately, I propose tentative recommendations which could help Cott and other educational institutions to achieve long-term improvement in organisational leadership and management.
- Full Text:
Bioaccumulation of heavy metals by the yeast S. cerevisiae and the bioremediation of industrial waste water
- Authors: Stoll, Anita
- Date: 1997
- Subjects: Saccharomyces cerevisiae Yeast fungi -- Biotechnology Metal ions Bioremediation Water -- Purification -- Biological treatment
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4015 , http://hdl.handle.net/10962/d1004075
- Description: Water is an essential element in all aspects of life and is vital for both domestic and industrial purposes regarding both the quality and quantity thereof. Similar to many other drought stricken countries, South Africa requires water for the socio-economic growth of the country, yet is faced with the problem of maintaining the quality of its drinking water as well as protecting the dwindling supplies. In an attempt to prevent the deterioration of South African water supplies the treatment, purification and recycling of industrial and mining waste water has recently become of prime importance. Many industrial and mining waste waters contain heavy metals in toxic quantities. The conventional processes that have been used till recently to address this problem, are often expensive or contain chemical agents which compound the environmental problem. As an alternative biological methods of metal accumulation appear to offer an economic and efficient alternative to these methods. An advantage to the South African scenario is the commercial production of the yeast, S. cerevisiae as a readily inexpensive by-product from some fermentation industries, Yeast cells, and in particular S. cerevisiae have proven to be capable of accumulating heavy metals, and therefore exhibit potential application in the bioremediation of waste water. The aim of this project was twofold. The initial part of this work attempted to define the mechanisms of metal accumulation by the yeast cells and cellular components. The information obtained from these initial studies provided a data base required for the development of a bioremediation system. Initial contact with the metal ions occurs at the wall interface of the yeast cell. Metal accumulation appears to be a function of all the cell wall components. The isolated cell wall components are better metal chelators then the intact cell walls. An apparent affinity series of mannan > chitin> glucan > intact cell walls exists. However, these components differ in their affinities for metal ions. Storage of metal ions within the cell occurs predominantly in the vacuole. The present study concluded that metal accumulation by the vacuole could be related to size. Metal accumulation occurred in the order of Cu2+ > Co2+ > Cd2+ with a corresponding decrease in atomic radii of Cd2+ > C02+ > Cu2+. Vacuolar ion deposition occurs at an early stage during the internalization of metal ions within the yeast cells. At the onset of vacuolar saturation, depositions of metal ions as granules within the cytosol occurs. In the presence of heavy metal cations viable yeast cells can be shown to exhibit two types of cellular responses. Uptake of Cu2+ and Cd2+ causes the loss of intracellular physiological cations from within the yeast cell. In comparison, uptake of Co2+ into the cell does not have this effect. All three heavy metal cations initiate plasma cell membrane permeability, thus the Cu2+ and Cd2+ induced loss of the intracellular cations, occurs. ~ a result of ion-exchange mechanisms and not due to cation leakage brought about by membrane permeabilization. Uptake of heavy metals by viable yeasts appears to be generally non-selective though the amount of metals accumulated are largely affected by the ratio of ambient metal concentration to biomass quantity. In addition, the energy dependent nature of internalization necessitates the availability of an external energy source for metal uptake by viable yeast cells. For these reasons metal removal from industrial waste water was investigated using non-viable biomass. By immobilizing the yeast cells additional mechanical integrity and stability was conferred apon the biomass. The three types of biomass preparations developed in this study, viz. polyvinyl alcohol (PV A) Na-alginate, PV A Na-orthophosphate and alkali treated polyethylenimine (PEI):glutaraldehyde (GA) biomass pellets, all fulfilled the necessary physical requirements. However, the superior metal accumulating properties of the PEI:GA biomass determined its selection as a biosorbent for bioremediation purposes. Biosorption of heavy metals by PEI:GA biomass is of a competitive nature, with the amount of metal accumulated influenced by the availability of the metal ions. This availability is largely determined by the solution pH. At low pH values the affinity of the biomass for metals decreases, whilst enhanced metal biosorption occurs at higher pHs, ego pH 4.5 - 6.0. PEI:GA biomass pellets can be implemented -as a biosorbent for the bi9remediaiton of high concentration, low-volume metal containing industrial waste. Several options regarding the bioremediation system are available. Depending on the concentration of the metals in the effluent, the bioremediation process can either be used independently or as part of a biphasic remediation system for the treatment of waste water. Initial phase chemical modification may be required, whilst two types of biological systems can be implemented as 'part of the second phase. The PEI:GA biomass can either be contained within continuous-flow fixed bed tanks or continuous-flow stirred bioreactor tanks. Due to the simplicity of the process and the ease with which scale-up is facilitated, the second type of system shows greater application potential for the treatment of this type of industrial waste water than the fixed-bed systems.
- Full Text:
- Date Issued: 1997
- Authors: Stoll, Anita
- Date: 1997
- Subjects: Saccharomyces cerevisiae Yeast fungi -- Biotechnology Metal ions Bioremediation Water -- Purification -- Biological treatment
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4015 , http://hdl.handle.net/10962/d1004075
- Description: Water is an essential element in all aspects of life and is vital for both domestic and industrial purposes regarding both the quality and quantity thereof. Similar to many other drought stricken countries, South Africa requires water for the socio-economic growth of the country, yet is faced with the problem of maintaining the quality of its drinking water as well as protecting the dwindling supplies. In an attempt to prevent the deterioration of South African water supplies the treatment, purification and recycling of industrial and mining waste water has recently become of prime importance. Many industrial and mining waste waters contain heavy metals in toxic quantities. The conventional processes that have been used till recently to address this problem, are often expensive or contain chemical agents which compound the environmental problem. As an alternative biological methods of metal accumulation appear to offer an economic and efficient alternative to these methods. An advantage to the South African scenario is the commercial production of the yeast, S. cerevisiae as a readily inexpensive by-product from some fermentation industries, Yeast cells, and in particular S. cerevisiae have proven to be capable of accumulating heavy metals, and therefore exhibit potential application in the bioremediation of waste water. The aim of this project was twofold. The initial part of this work attempted to define the mechanisms of metal accumulation by the yeast cells and cellular components. The information obtained from these initial studies provided a data base required for the development of a bioremediation system. Initial contact with the metal ions occurs at the wall interface of the yeast cell. Metal accumulation appears to be a function of all the cell wall components. The isolated cell wall components are better metal chelators then the intact cell walls. An apparent affinity series of mannan > chitin> glucan > intact cell walls exists. However, these components differ in their affinities for metal ions. Storage of metal ions within the cell occurs predominantly in the vacuole. The present study concluded that metal accumulation by the vacuole could be related to size. Metal accumulation occurred in the order of Cu2+ > Co2+ > Cd2+ with a corresponding decrease in atomic radii of Cd2+ > C02+ > Cu2+. Vacuolar ion deposition occurs at an early stage during the internalization of metal ions within the yeast cells. At the onset of vacuolar saturation, depositions of metal ions as granules within the cytosol occurs. In the presence of heavy metal cations viable yeast cells can be shown to exhibit two types of cellular responses. Uptake of Cu2+ and Cd2+ causes the loss of intracellular physiological cations from within the yeast cell. In comparison, uptake of Co2+ into the cell does not have this effect. All three heavy metal cations initiate plasma cell membrane permeability, thus the Cu2+ and Cd2+ induced loss of the intracellular cations, occurs. ~ a result of ion-exchange mechanisms and not due to cation leakage brought about by membrane permeabilization. Uptake of heavy metals by viable yeasts appears to be generally non-selective though the amount of metals accumulated are largely affected by the ratio of ambient metal concentration to biomass quantity. In addition, the energy dependent nature of internalization necessitates the availability of an external energy source for metal uptake by viable yeast cells. For these reasons metal removal from industrial waste water was investigated using non-viable biomass. By immobilizing the yeast cells additional mechanical integrity and stability was conferred apon the biomass. The three types of biomass preparations developed in this study, viz. polyvinyl alcohol (PV A) Na-alginate, PV A Na-orthophosphate and alkali treated polyethylenimine (PEI):glutaraldehyde (GA) biomass pellets, all fulfilled the necessary physical requirements. However, the superior metal accumulating properties of the PEI:GA biomass determined its selection as a biosorbent for bioremediation purposes. Biosorption of heavy metals by PEI:GA biomass is of a competitive nature, with the amount of metal accumulated influenced by the availability of the metal ions. This availability is largely determined by the solution pH. At low pH values the affinity of the biomass for metals decreases, whilst enhanced metal biosorption occurs at higher pHs, ego pH 4.5 - 6.0. PEI:GA biomass pellets can be implemented -as a biosorbent for the bi9remediaiton of high concentration, low-volume metal containing industrial waste. Several options regarding the bioremediation system are available. Depending on the concentration of the metals in the effluent, the bioremediation process can either be used independently or as part of a biphasic remediation system for the treatment of waste water. Initial phase chemical modification may be required, whilst two types of biological systems can be implemented as 'part of the second phase. The PEI:GA biomass can either be contained within continuous-flow fixed bed tanks or continuous-flow stirred bioreactor tanks. Due to the simplicity of the process and the ease with which scale-up is facilitated, the second type of system shows greater application potential for the treatment of this type of industrial waste water than the fixed-bed systems.
- Full Text:
- Date Issued: 1997
Corporate taxes and the taxation of dividends
- Authors: Williams, John Mark
- Date: 1997
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:890 , http://hdl.handle.net/10962/d1001644
- Description: The classical system of taxation, whereby companies are taxed without a deduction for dividends paid and shareholders are taxed on their dividend receipts, results in double taxation of dividends. Split rate and imputation systems have been developed in an attempt to mitigate the effects of double taxation of dividends. Double taxation of dividends and differences between corporate and maximum individual marginal tax rates result in corporate tax systems lacking neutrality. Distortions arise between organisational forms, between debt and equity financing and between the retention and distribution of profits. Various methods of integrating corporate and individual taxes have been advocated to overcome the lack of neutrality caused by corporate taxes. Following the introduction of the South African Income Tax Act in 1914, a number of taxes relating to dividends have existed. These have included a Dividend Tax, Non-resident Shareholder's Tax, Undistributed Profits Tax and Secondary Tax on Companies, hereafter referred to as STC. STC is a tax on net dividends declared and results in distributed income being taxed at higher rates than retained income. Despite the implementation of group relief provisions, STC results in an inhibition on the reinvestment of profits within the context of a group of companies. It is also a major cause of the lack of neutrality of the South African corporate tax system. As a result of the lack of neutrality and inhibition of group reinvestment caused by STC, a full imputation system is suggested as an alternative to replace STC.
- Full Text:
- Date Issued: 1997
- Authors: Williams, John Mark
- Date: 1997
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:890 , http://hdl.handle.net/10962/d1001644
- Description: The classical system of taxation, whereby companies are taxed without a deduction for dividends paid and shareholders are taxed on their dividend receipts, results in double taxation of dividends. Split rate and imputation systems have been developed in an attempt to mitigate the effects of double taxation of dividends. Double taxation of dividends and differences between corporate and maximum individual marginal tax rates result in corporate tax systems lacking neutrality. Distortions arise between organisational forms, between debt and equity financing and between the retention and distribution of profits. Various methods of integrating corporate and individual taxes have been advocated to overcome the lack of neutrality caused by corporate taxes. Following the introduction of the South African Income Tax Act in 1914, a number of taxes relating to dividends have existed. These have included a Dividend Tax, Non-resident Shareholder's Tax, Undistributed Profits Tax and Secondary Tax on Companies, hereafter referred to as STC. STC is a tax on net dividends declared and results in distributed income being taxed at higher rates than retained income. Despite the implementation of group relief provisions, STC results in an inhibition on the reinvestment of profits within the context of a group of companies. It is also a major cause of the lack of neutrality of the South African corporate tax system. As a result of the lack of neutrality and inhibition of group reinvestment caused by STC, a full imputation system is suggested as an alternative to replace STC.
- Full Text:
- Date Issued: 1997
Development of a novel, quantitative assay for determining the rate of activity of antimalarial drugs
- Authors: Khan, Tasmiyah
- Date: 2013
- Subjects: Assay , ATP , Antimalarials -- Therapeutic use Malaria Malaria -- Drug therapy Adenosine triphosphate Luciferases Plasmodium falciparum
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3884 , http://hdl.handle.net/10962/d1001618
- Description: Malaria, caused by an intracellular Plasmodium parasite, remains a devastating disease, having claimed approximately 655 000 lives worldwide in 2010. The Medicines for Malaria Venture suggests a "single-dose radical cure" as the ideal malaria treatment since rapid clearance of blood-stage parasites and symptom relief improves patient compliance and limits drug resistance. Thus, novel antimalarials should be rapid-acting and assessing their rate of activity is critical to drug discovery. Traditional evaluation of this rate by morphological assessments is flawed by highly subjective, operator-specific interpretations, mainly due to heterogeneous parasite morphology under routine culture conditions. This study aimed to develop an alternative, quantitative assay. Energy is vital for the growth and maintenance of all living organisms. Commercially available kits allow rapid quantification of the cell's energy currency, ATP. Therefore, quantification of parasite ATP shows potential for diagnosing abnormal parasite metabolism and the kinetics of drug action. In this study, a rapid protocol for detecting ATP in Plasmodium falciparum parasites using a luminescence-based kit was developed and optimised. Furthermore, luciferase-expressing transgenic parasites, in which luciferase activity is detected using a similar kit, were acquired. The utility of both methods for evaluating the rate of drug-induced stress was explored using antimalarials with varying modes of action and, presumably, rates of activity. Results showed that parasite ATP remained unchanged, increased or decreased during drug exposure. Morphological examinations by light microscopy and a Recovery assay, aided interpretation of the drug-induced changes in parasite ATP. These investigations suggested that unchanged parasite ATP levels reflect poor drug action, increased ATP levels indicate a stress response and partially compromised viability, while significantly reduced ATP reflects severely compromised viability. Concerning the Luciferase assay, parasite luciferase activity decreased during drug exposure, even in the presence of proteasome inhibitors. Changes in parasite ATP and luciferase activity occurred at rates which suggested that chloroquine is slow-acting, mefloquine has a moderate rate of activity and artemisinin is rapid-acting. These findings are compatible with the expected rates of activity of these established antimalarials. Hence, measurement of parasite ATP and/or luciferase activity may support assessments of parasite health and the kinetics of antimalarial action during drug discovery
- Full Text:
- Date Issued: 2013
- Authors: Khan, Tasmiyah
- Date: 2013
- Subjects: Assay , ATP , Antimalarials -- Therapeutic use Malaria Malaria -- Drug therapy Adenosine triphosphate Luciferases Plasmodium falciparum
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3884 , http://hdl.handle.net/10962/d1001618
- Description: Malaria, caused by an intracellular Plasmodium parasite, remains a devastating disease, having claimed approximately 655 000 lives worldwide in 2010. The Medicines for Malaria Venture suggests a "single-dose radical cure" as the ideal malaria treatment since rapid clearance of blood-stage parasites and symptom relief improves patient compliance and limits drug resistance. Thus, novel antimalarials should be rapid-acting and assessing their rate of activity is critical to drug discovery. Traditional evaluation of this rate by morphological assessments is flawed by highly subjective, operator-specific interpretations, mainly due to heterogeneous parasite morphology under routine culture conditions. This study aimed to develop an alternative, quantitative assay. Energy is vital for the growth and maintenance of all living organisms. Commercially available kits allow rapid quantification of the cell's energy currency, ATP. Therefore, quantification of parasite ATP shows potential for diagnosing abnormal parasite metabolism and the kinetics of drug action. In this study, a rapid protocol for detecting ATP in Plasmodium falciparum parasites using a luminescence-based kit was developed and optimised. Furthermore, luciferase-expressing transgenic parasites, in which luciferase activity is detected using a similar kit, were acquired. The utility of both methods for evaluating the rate of drug-induced stress was explored using antimalarials with varying modes of action and, presumably, rates of activity. Results showed that parasite ATP remained unchanged, increased or decreased during drug exposure. Morphological examinations by light microscopy and a Recovery assay, aided interpretation of the drug-induced changes in parasite ATP. These investigations suggested that unchanged parasite ATP levels reflect poor drug action, increased ATP levels indicate a stress response and partially compromised viability, while significantly reduced ATP reflects severely compromised viability. Concerning the Luciferase assay, parasite luciferase activity decreased during drug exposure, even in the presence of proteasome inhibitors. Changes in parasite ATP and luciferase activity occurred at rates which suggested that chloroquine is slow-acting, mefloquine has a moderate rate of activity and artemisinin is rapid-acting. These findings are compatible with the expected rates of activity of these established antimalarials. Hence, measurement of parasite ATP and/or luciferase activity may support assessments of parasite health and the kinetics of antimalarial action during drug discovery
- Full Text:
- Date Issued: 2013
Does primary resource-based industrialisation offer an escape from underdevelopment?
- Authors: Ali, Fatimah
- Date: 2006
- Subjects: Comparative advantage (International trade) , Exports -- Africa, West , Exports -- Mauritius , Exports -- South Africa , Foreign trade promotion -- Mauritius , International trade , Primary commodities -- Africa , Human capital -- Economic aspects -- Africa , Natural resources -- Africa , Africa -- Commerce
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1018 , http://hdl.handle.net/10962/d1002753 , Comparative advantage (International trade) , Exports -- Africa, West , Exports -- Mauritius , Exports -- South Africa , Foreign trade promotion -- Mauritius , International trade , Primary commodities -- Africa , Human capital -- Economic aspects -- Africa , Natural resources -- Africa , Africa -- Commerce
- Description: It is commonly believed about sub-Saharan Africa (SSA) that the region has a comparative advantage in primary resources as reflected by its high share of primary exports to total exports. In acknowledging the region's comparative advantage, the study tries to put the determinants from the Wood and Mayer (1998, (999) (W-M) Heckscher-Ohlin based model in the context of two relatively diversified countries (South Africa and Mauritius) and two commodity-export-dependent countries of sub-Saharan Africa (Nigeria and Cô̌̌te d'Ivoire). The study finds that the skill and land resource measures used in the W -M (1998, 1999) thesis do not explain why Nigeria, having a similar level of skill per worker ratio to South Africa, has not diversified. Further, Mauritius having relatively the highest skill per land ratio specialises in low-skill textiles and clothing, while South Africa specialises in the more human capital-intensive "other manufactures" group. The other measure, a low land per worker ratio that explains Mauritius' relatively higher share of manufacturing exports, also fails to apply to Nigeria. The thesis thus concludes that the W-M land and skill measures could only be rough proxies in determining comparative advantage in manufacturing exports. However, employing the Dutch disease hypothesis recognises the potential of land abundance as a natural resource, namely minerals in South Africa, oil in Nigeria, and cocoa in Cǒ̌te d'Ivoire. The Dutch disease is a dynamic process of structural economic and political development that will permit an understanding of why natural resource abundant countries do not have a comparative advantage in manufacturing, at least in the short to medium term. The study therefore investigates commodity dependence and the Dutch disease effects to examine whether primary resource- based industrialisation offers an escape from underdevelopment. It establishes that South Africa, a mineral resource rich country, diversified based on a broad mineral-energy-complex (MEC) reinforcing the notion that land abundant countries will first invest in capital- intensive primary resource processing. However, the thesis concludes that in Nigeria and Cǒ̌te d'Ivoire where external shocks are more predominant probably because of single commodity export reliance, the manufacturing sector lags behind more due to resource and spending effects that a natural resource boom generates in these economies.
- Full Text:
- Date Issued: 2006
- Authors: Ali, Fatimah
- Date: 2006
- Subjects: Comparative advantage (International trade) , Exports -- Africa, West , Exports -- Mauritius , Exports -- South Africa , Foreign trade promotion -- Mauritius , International trade , Primary commodities -- Africa , Human capital -- Economic aspects -- Africa , Natural resources -- Africa , Africa -- Commerce
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1018 , http://hdl.handle.net/10962/d1002753 , Comparative advantage (International trade) , Exports -- Africa, West , Exports -- Mauritius , Exports -- South Africa , Foreign trade promotion -- Mauritius , International trade , Primary commodities -- Africa , Human capital -- Economic aspects -- Africa , Natural resources -- Africa , Africa -- Commerce
- Description: It is commonly believed about sub-Saharan Africa (SSA) that the region has a comparative advantage in primary resources as reflected by its high share of primary exports to total exports. In acknowledging the region's comparative advantage, the study tries to put the determinants from the Wood and Mayer (1998, (999) (W-M) Heckscher-Ohlin based model in the context of two relatively diversified countries (South Africa and Mauritius) and two commodity-export-dependent countries of sub-Saharan Africa (Nigeria and Cô̌̌te d'Ivoire). The study finds that the skill and land resource measures used in the W -M (1998, 1999) thesis do not explain why Nigeria, having a similar level of skill per worker ratio to South Africa, has not diversified. Further, Mauritius having relatively the highest skill per land ratio specialises in low-skill textiles and clothing, while South Africa specialises in the more human capital-intensive "other manufactures" group. The other measure, a low land per worker ratio that explains Mauritius' relatively higher share of manufacturing exports, also fails to apply to Nigeria. The thesis thus concludes that the W-M land and skill measures could only be rough proxies in determining comparative advantage in manufacturing exports. However, employing the Dutch disease hypothesis recognises the potential of land abundance as a natural resource, namely minerals in South Africa, oil in Nigeria, and cocoa in Cǒ̌te d'Ivoire. The Dutch disease is a dynamic process of structural economic and political development that will permit an understanding of why natural resource abundant countries do not have a comparative advantage in manufacturing, at least in the short to medium term. The study therefore investigates commodity dependence and the Dutch disease effects to examine whether primary resource- based industrialisation offers an escape from underdevelopment. It establishes that South Africa, a mineral resource rich country, diversified based on a broad mineral-energy-complex (MEC) reinforcing the notion that land abundant countries will first invest in capital- intensive primary resource processing. However, the thesis concludes that in Nigeria and Cǒ̌te d'Ivoire where external shocks are more predominant probably because of single commodity export reliance, the manufacturing sector lags behind more due to resource and spending effects that a natural resource boom generates in these economies.
- Full Text:
- Date Issued: 2006
Enhancing the critical reading skills of student teachers in Namibia : An action research project
- Authors: Dikuwa, Alexander
- Date: 2012
- Subjects: Reading (Higher education) Critical thinking , Teachers -- Training of -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1912 , http://hdl.handle.net/10962/d1007162
- Description: This thesis reports on a responsive action research case study undertaken to teach student teachers to read critically. I undertook this research to gain a basic knowledge about critical reading as well as to form a knowledge base that would enable me to teach it effectively. First, I gave students a diagnostic assessment activity, analyzed the result and established the students’ ability to read a text critically. After I had established the students’ strengths, weaknesses, and the requirements to move students from their existing critical reading competency to an improved one, I reviewed the literature to provide me with a theory of teaching critical reading. The lessons were then planned and taught. The lessons; focus group interviews; researcher’s diary; students’ reflections and non-participant observer comments formed the data of the study. The data were analyzed using the framework of “what went well”, “what did not go well” and “what needs to be improved if the lessons were to be repeated”. The main purpose was to address the goals of the research, which were to find effective ways of teaching critical reading, appropriate critical reading materials, and to identify any pedagogic shortcomings. The 30 students who took part in this research were third-year students studying English Second language and Mother tongue pedagogies to become specialists in the teaching of both at Junior Secondary level (grades 8 – 10). The study was guided by constructivist theory, which underpins learner-centred education, which continues to inform and shape the development of curricula in Namibia.
- Full Text:
- Date Issued: 2012
- Authors: Dikuwa, Alexander
- Date: 2012
- Subjects: Reading (Higher education) Critical thinking , Teachers -- Training of -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1912 , http://hdl.handle.net/10962/d1007162
- Description: This thesis reports on a responsive action research case study undertaken to teach student teachers to read critically. I undertook this research to gain a basic knowledge about critical reading as well as to form a knowledge base that would enable me to teach it effectively. First, I gave students a diagnostic assessment activity, analyzed the result and established the students’ ability to read a text critically. After I had established the students’ strengths, weaknesses, and the requirements to move students from their existing critical reading competency to an improved one, I reviewed the literature to provide me with a theory of teaching critical reading. The lessons were then planned and taught. The lessons; focus group interviews; researcher’s diary; students’ reflections and non-participant observer comments formed the data of the study. The data were analyzed using the framework of “what went well”, “what did not go well” and “what needs to be improved if the lessons were to be repeated”. The main purpose was to address the goals of the research, which were to find effective ways of teaching critical reading, appropriate critical reading materials, and to identify any pedagogic shortcomings. The 30 students who took part in this research were third-year students studying English Second language and Mother tongue pedagogies to become specialists in the teaching of both at Junior Secondary level (grades 8 – 10). The study was guided by constructivist theory, which underpins learner-centred education, which continues to inform and shape the development of curricula in Namibia.
- Full Text:
- Date Issued: 2012
FRAME: frame routing and manipulation engine
- Authors: Pennefather, Sean Niel
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3608 , vital:20529
- Description: This research reports on the design and implementation of FRAME: an embedded hardware network processing platform designed to perform network frame manipulation and monitoring. This is possible at line speeds compliant with the IEEE 802.3 Ethernet standard. The system provides frame manipulation functionality to aid in the development and implementation of network testing environments. Platform cost and ease of use are both considered during design resulting in fabrication of hardware and the development of Link, a Domain Specific Language used to create custom applications that are compatible with the platform. Functionality of the resulting platform is shown through conformance testing of designed modules and application examples. Throughput testing showed that the peak throughput achievable by the platform is limited to 86.4 Mbit/s, comparable to commodity 100 Mbit hardware and the total cost of the prototype platform ranged between $220 and $254.
- Full Text:
- Date Issued: 2016
- Authors: Pennefather, Sean Niel
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3608 , vital:20529
- Description: This research reports on the design and implementation of FRAME: an embedded hardware network processing platform designed to perform network frame manipulation and monitoring. This is possible at line speeds compliant with the IEEE 802.3 Ethernet standard. The system provides frame manipulation functionality to aid in the development and implementation of network testing environments. Platform cost and ease of use are both considered during design resulting in fabrication of hardware and the development of Link, a Domain Specific Language used to create custom applications that are compatible with the platform. Functionality of the resulting platform is shown through conformance testing of designed modules and application examples. Throughput testing showed that the peak throughput achievable by the platform is limited to 86.4 Mbit/s, comparable to commodity 100 Mbit hardware and the total cost of the prototype platform ranged between $220 and $254.
- Full Text:
- Date Issued: 2016
Happiness levels amongst South African Veterinarians
- Authors: Venter,Cordene
- Date: 2018
- Subjects: Happiness , Job satisfaction , Veterinarians -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/45745 , vital:38960
- Description: Happiness is a new field of study in various healthcare fields. Researchers indicated that although there are numerous studies investigating mental well-being amongst veterinarians, scientific research into happiness in veterinary medicine has not begun and that happiness levels of veterinarians are unknown. This treatise is the first known study examining the happiness levels of South African veterinarians and the implications that increased happiness levels can have for organisations who employ veterinarians. An in-depth literature review was conducted and the two main constructs of happiness – eudaimonia and hedonism were examined. Additionally, the three theories of happiness, namely set-point theory, social comparison theory and the affect theory were explored and the importance of happiness in the workplace was established. The literature further laid the foundation for the conceptual model that proposed influence in the workplace, social relationships, satisfaction with work-life balance, purpose, optimism, work satisfaction, work stress and leisure lead to happiness of South African veterinarians. The study concludes with managerial recommendations that veterinary practice owners can implement to increase the happiness levels of their veterinarians so that they can have social, financial and personal gain. encourage their employees to pursue leisure activities. Life coaches or industrial psychologists can be used to bridge the generational gap between veterinarians and to minimise interpersonal conflict. Moreover, managers need to have conversations with their employees to understand their needs and to help them achieve their professional goals.
- Full Text:
- Date Issued: 2018
- Authors: Venter,Cordene
- Date: 2018
- Subjects: Happiness , Job satisfaction , Veterinarians -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/45745 , vital:38960
- Description: Happiness is a new field of study in various healthcare fields. Researchers indicated that although there are numerous studies investigating mental well-being amongst veterinarians, scientific research into happiness in veterinary medicine has not begun and that happiness levels of veterinarians are unknown. This treatise is the first known study examining the happiness levels of South African veterinarians and the implications that increased happiness levels can have for organisations who employ veterinarians. An in-depth literature review was conducted and the two main constructs of happiness – eudaimonia and hedonism were examined. Additionally, the three theories of happiness, namely set-point theory, social comparison theory and the affect theory were explored and the importance of happiness in the workplace was established. The literature further laid the foundation for the conceptual model that proposed influence in the workplace, social relationships, satisfaction with work-life balance, purpose, optimism, work satisfaction, work stress and leisure lead to happiness of South African veterinarians. The study concludes with managerial recommendations that veterinary practice owners can implement to increase the happiness levels of their veterinarians so that they can have social, financial and personal gain. encourage their employees to pursue leisure activities. Life coaches or industrial psychologists can be used to bridge the generational gap between veterinarians and to minimise interpersonal conflict. Moreover, managers need to have conversations with their employees to understand their needs and to help them achieve their professional goals.
- Full Text:
- Date Issued: 2018
Insect pests of cultivated and wild olives, and some of their natural enemies, in the Eastern Cape, South Africa
- Authors: Mkize, Nolwazi
- Date: 2009
- Subjects: Pests -- Control -- South Africa -- Eastern Cape Olive -- Diseases and pests -- South Africa -- Eastern Cape Agriculture -- South Africa -- Eastern Cape Fruit-flies -- South Africa -- Eastern Cape Tephritidae Flea beetles Lace bugs
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5717 , http://hdl.handle.net/10962/d1005403
- Description: This thesis has two focuses. The first problem facing the olive industry in the Eastern Cape is the growers’ perceptions of both what the industry will provide them and what a pest management program might entail. The second focus is the biology of olive pests in the Eastern Cape in terms of understanding their populations and their natural enemies on private farms, with future hopes of understanding how Integrated Pest Management strategies can be developed for this crop. Eastern Cape private farmers, small-scale farmers and workers from agricultural training institutions were interviewed regarding the history and cultivation of the local olive crop. Only one commercially viable olive grove was identified; other groves were small, experimental pilot ventures. The introduction of olives to small-scale farmers and agricultural training schools was generally a top-down initiative that led to a lack of sense of ownership and the trees being neglected. Other problems included poor human capital; poor financial capital; lack of adequate support; lack of knowledge transfer and stability; lack of communication and evaluation procedures of the project; miscommunication; and finally, olive pests. Apart from hesitancy to plant at a commercial scale, the main problem facing private farmers (Varnam Farm, Hewlands Farm and Springvale Farm) was pests. Therefore an investigation of pests from private farms was conducted ranging from collection of cultivated and wild olive fruit and flea beetle larvae for parasitism, trapping systems both for fruit flies and olive flea beetle adults. A survey of olive fruits yielded larval fruit flies of the families Tephritidae (Bactrocera oleae (Rossi), B. biguttula (Bezzi) and Ceratitis capitata (Wiedemann)) and Drosophilidae (Drosophila melanogaster (Meigen)) from wild olives (O. europaea cuspidata (Wall. ex G. Don) Cif.) but none from cultivated olives (O. e. europaea L.). Braconid wasps (Opiinae and Braconinae) were reared only from fruits containing B. oleae and B. biguttula. This suggests that B. oleae is not of economic significance in the Eastern Cape, perhaps because it is controlled to a significant level by natural enemies, but B. biguttula may be a potential economic pest. A survey of adult fruit flies using ChamP traps baited with ammonium bicarbonate and spiroketal capsules and Sensus trap baited with methyl eugenol and Questlure confirmed the relative importance of B. biguttula over B. oleae. ChamP traps were over 50 times better than Sensus traps for mass trapping of B. biguttula but both were ineffective for trapping B. oleae and C. capitata. Six indigenous flea beetles of the genus Argopistes Motschulsky (Chrysomelidae: Alticinae) were found, three described by Bryant in 1922 and 1944 and three new species. Their morphology was investigated by scanning electron microscopy and mutivariate morphometric analysis. The leaf-mining larvae are pests of wild and cultivated olives in South Africa and threaten the local olive industry. At Springvale Farm, A. oleae Bryant and A. sexvittatus Bryant preferred the upper parts of trees, near new leaves. Pseudophanomeris inopinatus (Blkb.) (Braconidae) was reared from 23 Argopistes larvae. The beetle larvae might not be controlled to a significant level by natural enemies because the rate of parasitism was low. The olive flea beetles showed no attraction to traps containing various volatile compounds as baits. The lace bug, Plerochila australis Distant (Tingidae), was sometimes a pest. It showed a preference for the underside of leaves on the lower parts of the trees. A moth, Palpita unionalis Hübner (Crambidae), was reared in very low numbers and without parasitoids. A twig-boring beetle larva, chalcidoid parasitoids and seed wasps of the families Eurytomidae, Ormyridae and Eupelmidae were also recorded.
- Full Text:
- Date Issued: 2009
- Authors: Mkize, Nolwazi
- Date: 2009
- Subjects: Pests -- Control -- South Africa -- Eastern Cape Olive -- Diseases and pests -- South Africa -- Eastern Cape Agriculture -- South Africa -- Eastern Cape Fruit-flies -- South Africa -- Eastern Cape Tephritidae Flea beetles Lace bugs
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5717 , http://hdl.handle.net/10962/d1005403
- Description: This thesis has two focuses. The first problem facing the olive industry in the Eastern Cape is the growers’ perceptions of both what the industry will provide them and what a pest management program might entail. The second focus is the biology of olive pests in the Eastern Cape in terms of understanding their populations and their natural enemies on private farms, with future hopes of understanding how Integrated Pest Management strategies can be developed for this crop. Eastern Cape private farmers, small-scale farmers and workers from agricultural training institutions were interviewed regarding the history and cultivation of the local olive crop. Only one commercially viable olive grove was identified; other groves were small, experimental pilot ventures. The introduction of olives to small-scale farmers and agricultural training schools was generally a top-down initiative that led to a lack of sense of ownership and the trees being neglected. Other problems included poor human capital; poor financial capital; lack of adequate support; lack of knowledge transfer and stability; lack of communication and evaluation procedures of the project; miscommunication; and finally, olive pests. Apart from hesitancy to plant at a commercial scale, the main problem facing private farmers (Varnam Farm, Hewlands Farm and Springvale Farm) was pests. Therefore an investigation of pests from private farms was conducted ranging from collection of cultivated and wild olive fruit and flea beetle larvae for parasitism, trapping systems both for fruit flies and olive flea beetle adults. A survey of olive fruits yielded larval fruit flies of the families Tephritidae (Bactrocera oleae (Rossi), B. biguttula (Bezzi) and Ceratitis capitata (Wiedemann)) and Drosophilidae (Drosophila melanogaster (Meigen)) from wild olives (O. europaea cuspidata (Wall. ex G. Don) Cif.) but none from cultivated olives (O. e. europaea L.). Braconid wasps (Opiinae and Braconinae) were reared only from fruits containing B. oleae and B. biguttula. This suggests that B. oleae is not of economic significance in the Eastern Cape, perhaps because it is controlled to a significant level by natural enemies, but B. biguttula may be a potential economic pest. A survey of adult fruit flies using ChamP traps baited with ammonium bicarbonate and spiroketal capsules and Sensus trap baited with methyl eugenol and Questlure confirmed the relative importance of B. biguttula over B. oleae. ChamP traps were over 50 times better than Sensus traps for mass trapping of B. biguttula but both were ineffective for trapping B. oleae and C. capitata. Six indigenous flea beetles of the genus Argopistes Motschulsky (Chrysomelidae: Alticinae) were found, three described by Bryant in 1922 and 1944 and three new species. Their morphology was investigated by scanning electron microscopy and mutivariate morphometric analysis. The leaf-mining larvae are pests of wild and cultivated olives in South Africa and threaten the local olive industry. At Springvale Farm, A. oleae Bryant and A. sexvittatus Bryant preferred the upper parts of trees, near new leaves. Pseudophanomeris inopinatus (Blkb.) (Braconidae) was reared from 23 Argopistes larvae. The beetle larvae might not be controlled to a significant level by natural enemies because the rate of parasitism was low. The olive flea beetles showed no attraction to traps containing various volatile compounds as baits. The lace bug, Plerochila australis Distant (Tingidae), was sometimes a pest. It showed a preference for the underside of leaves on the lower parts of the trees. A moth, Palpita unionalis Hübner (Crambidae), was reared in very low numbers and without parasitoids. A twig-boring beetle larva, chalcidoid parasitoids and seed wasps of the families Eurytomidae, Ormyridae and Eupelmidae were also recorded.
- Full Text:
- Date Issued: 2009
Investigating an environmental education curriculum to a developing society's needs: a case study of the programme offered at the Pilanesberg National Park, Bophuthatswana
- Authors: Johnson, Steven Robert
- Date: 1994
- Subjects: Environmental education Environmental education -- Curricula -- South Africa -- Bophuthatswana Environmental education -- Curricula -- Case studies Pilanesberg National Park (South Africa)
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1585 , http://hdl.handle.net/10962/d1003467
- Description: The Environmental Education programme offered at the Gold Fields Environmental Education Centre (GFEE Centre) in the Pilanesberg National Park, Bophuthatswana, was initiated in response to requests from schools in Bophuthatswana to visit game reserves as 'syllabus related school activities'. Evaluative research into the GFEE Centre programme by an external researcher indicated that the learning experiences largely concentrated on cognitive development, and neglected to influence affective and psychomotor development. After a number of adaptations to the programme, which emphasised a more child-centred approach it was realised that little was known about the background and learning needs of the predominantly BaTswana school children. It was felt by the researcher that the learning activities provided at the GFEE Centre could also possibly be biased by a Western, scientific orientation which possibly lacked relevance to the cultural backgrounds of the pupils. The researcher used an action research approach in a number of workshops with a purposive sample of BaTswana primary school teachers, to gather data. The teachers were encouraged to critically reflect on the background and learning-needs of BaTswana children, with specific regard to environmental issues and worldviews. The information provided by the teachers' reflective deliberations and a seperate research project with school children, indicated that primary school children in Bophuthatswana tend to follow accepted human development patterns in their perceptions of the environment. The influence of either a predominantly rural or urban upbringing during a child's early formative years was considered by the teachers to be significant in determining worldviews, and culture was considered to have an influence on children's learning processes. Their beliefs and experiences were used by them in generating suggestions to correct the GFEE Centre programme. The teachers' also highlighted the fact that there were a number of socio-cultural and institutional issues which influenced the effectiveness of the GFEE Centre programme.
- Full Text:
- Date Issued: 1994
- Authors: Johnson, Steven Robert
- Date: 1994
- Subjects: Environmental education Environmental education -- Curricula -- South Africa -- Bophuthatswana Environmental education -- Curricula -- Case studies Pilanesberg National Park (South Africa)
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1585 , http://hdl.handle.net/10962/d1003467
- Description: The Environmental Education programme offered at the Gold Fields Environmental Education Centre (GFEE Centre) in the Pilanesberg National Park, Bophuthatswana, was initiated in response to requests from schools in Bophuthatswana to visit game reserves as 'syllabus related school activities'. Evaluative research into the GFEE Centre programme by an external researcher indicated that the learning experiences largely concentrated on cognitive development, and neglected to influence affective and psychomotor development. After a number of adaptations to the programme, which emphasised a more child-centred approach it was realised that little was known about the background and learning needs of the predominantly BaTswana school children. It was felt by the researcher that the learning activities provided at the GFEE Centre could also possibly be biased by a Western, scientific orientation which possibly lacked relevance to the cultural backgrounds of the pupils. The researcher used an action research approach in a number of workshops with a purposive sample of BaTswana primary school teachers, to gather data. The teachers were encouraged to critically reflect on the background and learning-needs of BaTswana children, with specific regard to environmental issues and worldviews. The information provided by the teachers' reflective deliberations and a seperate research project with school children, indicated that primary school children in Bophuthatswana tend to follow accepted human development patterns in their perceptions of the environment. The influence of either a predominantly rural or urban upbringing during a child's early formative years was considered by the teachers to be significant in determining worldviews, and culture was considered to have an influence on children's learning processes. Their beliefs and experiences were used by them in generating suggestions to correct the GFEE Centre programme. The teachers' also highlighted the fact that there were a number of socio-cultural and institutional issues which influenced the effectiveness of the GFEE Centre programme.
- Full Text:
- Date Issued: 1994
Investigating teaching and learning within three Eastern Cape reception year classrooms
- Authors: Mnene, Mthetheleli
- Date: 2012
- Subjects: Competency-based education -- South Africa -- Eastern Cape Education, Elementary -- Social aspects -- South Africa -- Eastern Cape Curriculum evaluation -- South Africa -- Eastern Cape Education, Elementary -- South Africa -- Eastern Cape Education, Elementary -- Parent participation -- South Africa Education, Elementary -- Aims and objectives -- South Africa -- Eastern Cape Education, Elementary -- Curricula -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1589 , http://hdl.handle.net/10962/d1003471
- Description: The purpose of this study is to explore the extent to which young children in three Grade R classes in the Eastern Cape Province were exposed to developmentally appropriate opportunities to achieve the Critical Outcomes as outlined in the South African National Curriculum Statement. The research took the form of a case study. Semi-structured interviews and observations were used to collect data. Respondents included children, their parents, Grade R practitioners and the school leadership. The findings tentatively showed that this set of parents perceived their role in providing for their children’s developmental needs as separate to that of the GR practitioners. They seemed to see their roles as helping their children to develop social and emotional competence only, and that the GR practitioners provided, in addition to this, literacy and numeracy teaching to their children. In contrast, the three GR practitioners believed that parents were responsible also for promoting literacy, numeracy and life skills. There seemed therefore to be a lack of clarity of specific teacher and parent views of their roles. The researcher found, however, that the children seemed to be given few developmentally appropriate opportunities for planned and structured activities which enabled them to explore the Critical Outcomes, for example, working together, solving problems, using technology. The teaching methodology used by the GR practitioners during the observation periods, seemed to a large extent, to be based in 'talk and chalk' in the plenary grouping. It did not seem to enable the implementation of the curriculum and especially of the Critical Outcomes in a developmentally appropriate way. In addition, the environment in which children learned was not observed to be developmentally appropriate for relevant education to take place. Too many children were crowded into the available space, while learning equipment and materials were lacking. Any competences that young children in these three GR programmes achieved were therefore possibly learned incidentally, rather than deliberately through planned activities. In addition, GR classes in this study were not observed to be supported within the schools to deliver competent curriculum activities to the children. The study makes suggestions to meet some of these challenges. These include improving the understanding of curriculum guidelines of all role players in the three schools, enabling the management teams and especially parents to take a stronger support and monitoring role, and providing and using materials and equipment to promote the use of the Critical Out comes as methods for teaching and for learning.
- Full Text:
- Date Issued: 2012
- Authors: Mnene, Mthetheleli
- Date: 2012
- Subjects: Competency-based education -- South Africa -- Eastern Cape Education, Elementary -- Social aspects -- South Africa -- Eastern Cape Curriculum evaluation -- South Africa -- Eastern Cape Education, Elementary -- South Africa -- Eastern Cape Education, Elementary -- Parent participation -- South Africa Education, Elementary -- Aims and objectives -- South Africa -- Eastern Cape Education, Elementary -- Curricula -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1589 , http://hdl.handle.net/10962/d1003471
- Description: The purpose of this study is to explore the extent to which young children in three Grade R classes in the Eastern Cape Province were exposed to developmentally appropriate opportunities to achieve the Critical Outcomes as outlined in the South African National Curriculum Statement. The research took the form of a case study. Semi-structured interviews and observations were used to collect data. Respondents included children, their parents, Grade R practitioners and the school leadership. The findings tentatively showed that this set of parents perceived their role in providing for their children’s developmental needs as separate to that of the GR practitioners. They seemed to see their roles as helping their children to develop social and emotional competence only, and that the GR practitioners provided, in addition to this, literacy and numeracy teaching to their children. In contrast, the three GR practitioners believed that parents were responsible also for promoting literacy, numeracy and life skills. There seemed therefore to be a lack of clarity of specific teacher and parent views of their roles. The researcher found, however, that the children seemed to be given few developmentally appropriate opportunities for planned and structured activities which enabled them to explore the Critical Outcomes, for example, working together, solving problems, using technology. The teaching methodology used by the GR practitioners during the observation periods, seemed to a large extent, to be based in 'talk and chalk' in the plenary grouping. It did not seem to enable the implementation of the curriculum and especially of the Critical Outcomes in a developmentally appropriate way. In addition, the environment in which children learned was not observed to be developmentally appropriate for relevant education to take place. Too many children were crowded into the available space, while learning equipment and materials were lacking. Any competences that young children in these three GR programmes achieved were therefore possibly learned incidentally, rather than deliberately through planned activities. In addition, GR classes in this study were not observed to be supported within the schools to deliver competent curriculum activities to the children. The study makes suggestions to meet some of these challenges. These include improving the understanding of curriculum guidelines of all role players in the three schools, enabling the management teams and especially parents to take a stronger support and monitoring role, and providing and using materials and equipment to promote the use of the Critical Out comes as methods for teaching and for learning.
- Full Text:
- Date Issued: 2012
Numerical relativity on cosmological past null cones
- Van der Walt, Petrus Johannes
- Authors: Van der Walt, Petrus Johannes
- Date: 2013
- Subjects: Cosmology Numerical calculations General relativity (Physics) -- Mathematics Einstein field equations Gravity Gravitational waves Horizon
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5396 , http://hdl.handle.net/10962/d1002959
- Description: The observational approach to cosmology is the endeavour to reconstruct the geometry of the Universe using only data that is theoretically verifiable within the causal boundaries of a cosmological observer. Using this approach, it was shown in [36] that given ideal cosmological observations, the only essential assumption necessary to determine the geometry of the Universe is a theory of gravity. Assuming General Relativity, the full set of Einstein field equations (EFEs) can be used to reconstruct the geometry of the Universe using direct observations on the past null cone (PNC) as initial conditions. Observationally and theoretically this is a very ambitious task and therefore, current developments have been restricted to spherically symmetric dust models while only relaxing the usual assumption of homogeneity in the radial direction. These restricted models are important for the development of theoretical foundations and also useful as verification models since they avoid the circularity of verifying what has already been assumed. The work presented in this thesis is the development of such a model where numerical relativity (NR) is used to simulate the observable universe. Similar to the work of Ellis and co-workers [36], a reference frame based on the PNC is used. The reference frame used here, however, is based on that of the characteristic formalism of NR, which has developed for calculating the propagation of gravitational waves. This provides a formalism that is well established in NR, making the use of existing algorithms possible. The Bondi-Sachs coordinates of the characteristic formalism is, however, not suitable for calculations beyond the observer apparent horizon (AH) since the diameter distance used as a radial coordinate becomes multi-valued when the cosmological PNC reconverges in the history of a universe, smaller in the past. With this taken into consideration, the Bondi-Sachs characteristic formalism is implemented for cosmology and the problem approaching the AH is investigated. Further developments address the limitations approaching the AH by introducing a metric based on the Bondi-Sachs metric where the radial coordinate is replaced with an affine parameter. The model is derived with a cosmological constant Λ incorporated into the EFEs where Λ is taken as a parameter of the theory of gravity rather than as a matter source term. Similar to the conventional characteristic formalism, this model consists of a system of differential equations for numerically evolving the EFEs as a characteristic initial value problem (CIVP). A numerical code implemented for the method has been found to be second order convergent. This code enables simulations of different models given identical data on the initial null cone and provides a method to investigate their physical consistency within the causally connected region of our current PNC. These developments closely follow existing 3D schemes developed for gravitational wave simulations, which should make it natural to extend the affine CIVP beyond spherical symmetric simulations. The developments presented in this thesis is an extended version of two papers published earlier.
- Full Text:
- Date Issued: 2013
- Authors: Van der Walt, Petrus Johannes
- Date: 2013
- Subjects: Cosmology Numerical calculations General relativity (Physics) -- Mathematics Einstein field equations Gravity Gravitational waves Horizon
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5396 , http://hdl.handle.net/10962/d1002959
- Description: The observational approach to cosmology is the endeavour to reconstruct the geometry of the Universe using only data that is theoretically verifiable within the causal boundaries of a cosmological observer. Using this approach, it was shown in [36] that given ideal cosmological observations, the only essential assumption necessary to determine the geometry of the Universe is a theory of gravity. Assuming General Relativity, the full set of Einstein field equations (EFEs) can be used to reconstruct the geometry of the Universe using direct observations on the past null cone (PNC) as initial conditions. Observationally and theoretically this is a very ambitious task and therefore, current developments have been restricted to spherically symmetric dust models while only relaxing the usual assumption of homogeneity in the radial direction. These restricted models are important for the development of theoretical foundations and also useful as verification models since they avoid the circularity of verifying what has already been assumed. The work presented in this thesis is the development of such a model where numerical relativity (NR) is used to simulate the observable universe. Similar to the work of Ellis and co-workers [36], a reference frame based on the PNC is used. The reference frame used here, however, is based on that of the characteristic formalism of NR, which has developed for calculating the propagation of gravitational waves. This provides a formalism that is well established in NR, making the use of existing algorithms possible. The Bondi-Sachs coordinates of the characteristic formalism is, however, not suitable for calculations beyond the observer apparent horizon (AH) since the diameter distance used as a radial coordinate becomes multi-valued when the cosmological PNC reconverges in the history of a universe, smaller in the past. With this taken into consideration, the Bondi-Sachs characteristic formalism is implemented for cosmology and the problem approaching the AH is investigated. Further developments address the limitations approaching the AH by introducing a metric based on the Bondi-Sachs metric where the radial coordinate is replaced with an affine parameter. The model is derived with a cosmological constant Λ incorporated into the EFEs where Λ is taken as a parameter of the theory of gravity rather than as a matter source term. Similar to the conventional characteristic formalism, this model consists of a system of differential equations for numerically evolving the EFEs as a characteristic initial value problem (CIVP). A numerical code implemented for the method has been found to be second order convergent. This code enables simulations of different models given identical data on the initial null cone and provides a method to investigate their physical consistency within the causally connected region of our current PNC. These developments closely follow existing 3D schemes developed for gravitational wave simulations, which should make it natural to extend the affine CIVP beyond spherical symmetric simulations. The developments presented in this thesis is an extended version of two papers published earlier.
- Full Text:
- Date Issued: 2013
Participatory development (PD): NGOs and developmental practice in Zimbabwe
- Authors: Hwati, Lucky
- Date: 2013
- Language: English
- Type: Thesis , Masters , M Soc Sc (Dev)
- Identifier: vital:11446 , http://hdl.handle.net/10353/d1015315
- Description: The rising to prominence of Non- Governmental Organizations (NGOs) as essential partners to development was as a result of a shift in development authority into decentralized governance. Prior to this, the state was the central player in development. At liberation from political colonial control, most African governments adopted a centralized governance system. This meant that even in their drive to eco-socio development the state was the sole and most important driver. As explained by Allen (1995), in order to keep their grip on power, African leaders invented different solutions. Among them was an amplified centralization of its administrative device, or the creation of a centralized bureaucratic organization. Indeed, from 1960, the majority of African leaders banned political competition and instituted one-party regimes under which an ever-expanding bureaucracy was used to distribute resources to political allies, often under the form of membership in administrative positions (Allen, 1995). It was this need to keep a firm grip on power which saw most governments spearheading their own development, with NGOs playing a peripheral role. In the second instance, the state was instrumental in leading development. Throughout Africa, numerous government boards and ministries were created, each with a specific role to play in development (Willis, 2011; Allen, 1995). In the same way, most governments instituted policies and plans, with specific time frames, where certain development targets were supposed to be met. This system was adopted and became more pronounced in countries such as Malawi, Zambia and Zimbabwe.
- Full Text:
- Date Issued: 2013
- Authors: Hwati, Lucky
- Date: 2013
- Language: English
- Type: Thesis , Masters , M Soc Sc (Dev)
- Identifier: vital:11446 , http://hdl.handle.net/10353/d1015315
- Description: The rising to prominence of Non- Governmental Organizations (NGOs) as essential partners to development was as a result of a shift in development authority into decentralized governance. Prior to this, the state was the central player in development. At liberation from political colonial control, most African governments adopted a centralized governance system. This meant that even in their drive to eco-socio development the state was the sole and most important driver. As explained by Allen (1995), in order to keep their grip on power, African leaders invented different solutions. Among them was an amplified centralization of its administrative device, or the creation of a centralized bureaucratic organization. Indeed, from 1960, the majority of African leaders banned political competition and instituted one-party regimes under which an ever-expanding bureaucracy was used to distribute resources to political allies, often under the form of membership in administrative positions (Allen, 1995). It was this need to keep a firm grip on power which saw most governments spearheading their own development, with NGOs playing a peripheral role. In the second instance, the state was instrumental in leading development. Throughout Africa, numerous government boards and ministries were created, each with a specific role to play in development (Willis, 2011; Allen, 1995). In the same way, most governments instituted policies and plans, with specific time frames, where certain development targets were supposed to be met. This system was adopted and became more pronounced in countries such as Malawi, Zambia and Zimbabwe.
- Full Text:
- Date Issued: 2013
Phytochemical, antibacterial and pharmacological investigations of Clausena Anisata (Wild). Hook : bone of the medicinal plants used for traditional treatment of "tuberculosis" in Eastern Cape, South Africa
- Authors: Lawal, Ibraheem O
- Date: 2015
- Subjects: Traditional medicine--South Africa--Eastern Cape Tuberculosis--Treatment--South Africa--Eastern Cape Mycobacterial diseases--South Africa--Eastern Cape
- Language: English
- Type: Thesis , Doctoral , Ethnobotany
- Identifier: http://hdl.handle.net/10353/11828 , vital:39110
- Description: Clausena anisata (Willd) Hook, is the only species out of the 15 species of the genus found in the African continent and is regarded as a threatened species in this area of Southern region of Africa. Its distribution spread across Africa to south-east Asia. C. anisata has a wide range of ethno-pharmacological importance. Despite the numerous studies on the pharmacological profile of the plant, there is still dearth of scientific literature on the foliar micro-morphology of this valuable medicinal plant. The morphorlogical structure of the leaves of C. anisata was examined under Light Microscopy (LM), Scanning Electron Microscopy (SEM) and Energy Dispersive x-ray Spectroscopy (EDS) following standard procedures. LM indicates the types of stomata of the leaves (amphistomatic). SEM revealed the presence of the whip like trichomes with its uniqueness to the plants. EDS showed the chemical composition of the foliar appendages which indicated the presence Ca, Mg, S, and Fe. The indication of the elements could probably be helpful in the herbal drug regulation based on the mineral composition and in return reduced herbal drug toxicity.
- Full Text:
- Date Issued: 2015
- Authors: Lawal, Ibraheem O
- Date: 2015
- Subjects: Traditional medicine--South Africa--Eastern Cape Tuberculosis--Treatment--South Africa--Eastern Cape Mycobacterial diseases--South Africa--Eastern Cape
- Language: English
- Type: Thesis , Doctoral , Ethnobotany
- Identifier: http://hdl.handle.net/10353/11828 , vital:39110
- Description: Clausena anisata (Willd) Hook, is the only species out of the 15 species of the genus found in the African continent and is regarded as a threatened species in this area of Southern region of Africa. Its distribution spread across Africa to south-east Asia. C. anisata has a wide range of ethno-pharmacological importance. Despite the numerous studies on the pharmacological profile of the plant, there is still dearth of scientific literature on the foliar micro-morphology of this valuable medicinal plant. The morphorlogical structure of the leaves of C. anisata was examined under Light Microscopy (LM), Scanning Electron Microscopy (SEM) and Energy Dispersive x-ray Spectroscopy (EDS) following standard procedures. LM indicates the types of stomata of the leaves (amphistomatic). SEM revealed the presence of the whip like trichomes with its uniqueness to the plants. EDS showed the chemical composition of the foliar appendages which indicated the presence Ca, Mg, S, and Fe. The indication of the elements could probably be helpful in the herbal drug regulation based on the mineral composition and in return reduced herbal drug toxicity.
- Full Text:
- Date Issued: 2015
Polymerized serum albumin beads for use as slow-release adjuvants
- Martin, Michelle Elizabeth Denny
- Authors: Martin, Michelle Elizabeth Denny
- Date: 1988
- Subjects: Serum albumin , Antigens , Vaccines
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3879 , http://hdl.handle.net/10962/d1001613
- Description: Experimental vaccines have been made by covalently bonding virus particles into polymerized rabbit serum albumin beads. Using Nodamura virus as a model antigen, these model vaccines induced specific humoral antibody production, comparable with that achieved using Freund's adjuvants. Virus specific antibodies were also induced when Nodamura virus was covalently attached to the bead surface using different crosslinkers. However, when poliovirus type 2 (Sabin strain) was polymerized into beads, the levels of neutralizing antibodies were insignificant compared with control aqueous vaccines. The synthetic immunostimulator, muramyl dipeptide, was included with bead vaccines in an attempt to potentiate the immune response. Immunostimulation is achieved by a slow release of antigen coinciding with the gradual breakdown of bead structure.
- Full Text:
- Date Issued: 1988
- Authors: Martin, Michelle Elizabeth Denny
- Date: 1988
- Subjects: Serum albumin , Antigens , Vaccines
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3879 , http://hdl.handle.net/10962/d1001613
- Description: Experimental vaccines have been made by covalently bonding virus particles into polymerized rabbit serum albumin beads. Using Nodamura virus as a model antigen, these model vaccines induced specific humoral antibody production, comparable with that achieved using Freund's adjuvants. Virus specific antibodies were also induced when Nodamura virus was covalently attached to the bead surface using different crosslinkers. However, when poliovirus type 2 (Sabin strain) was polymerized into beads, the levels of neutralizing antibodies were insignificant compared with control aqueous vaccines. The synthetic immunostimulator, muramyl dipeptide, was included with bead vaccines in an attempt to potentiate the immune response. Immunostimulation is achieved by a slow release of antigen coinciding with the gradual breakdown of bead structure.
- Full Text:
- Date Issued: 1988
Production systems, profitability and participation in the mainstream markets by smallholder broiler chicken farmers of Maseru district in Lesotho
- Mphahama, Litsoanelo Evodiah
- Authors: Mphahama, Litsoanelo Evodiah
- Date: 2017
- Subjects: Broilers (Chickens)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8678 , vital:33423
- Description: Growth in global demand for broiler chicken meat has become tremendous, hence; as one segment of poultry, broiler chicken production has a privilege to highly contribute to nations’ nutritional demands because of the shorter productive age, with only 42 days needed to reach a marketable weight with a high rate of productivity. In fact; in developing countries the importance of broiler chickens to the national economy cannot be overemphasized, as it has become a popular industry especially for the smallholder farmers that have great contribution to the economies of their countries. However, it is difficult to see a bright future for smallholder broiler chicken farmers in this rapidly changing industry structure. A major concern is that this group of farmers faces severe constraints and challenges to taking advantage of mainstream market opportunities; a situation that would impede the success of the sector leading the farmers to exit the business. The aim of this study was to investigate factors challenging small-holder broiler chicken profitability and the choice of market channels used by these famers. The study was conducted in the Maseru district in Lesotho. Using availability sampling; 220 smallholder broiler chicken farming households were purposively selected. Data were obtained from secondary sources and by an administration of questionnaires from January until March 2016. Excel, XLSTAT and SPSS were used for analyzing the data. The descriptive findings of this study were applied to the biographical characteristics of the smallholder broiler chicken farmers. Ages, household size, marital status, occupation, source of credit and broiler chicken production system were determined using SPSS through graphs, mean and percentages. Findings from determining broiler chicken profitability revealed that a mean gross margin of M607.74 in the rural areas and M665.13 from the urban areas were obtained. The results indicated broiler chicken feeds and day old chicks as major operational costs in broiler chicken rearing. This study also explored factors that influence broiler chicken profitability on smallholder farmers. The results suggest that cost starter feeds, cost finisher feeds, transport cost and cost dox/doc negatively affected broiler chicken profits while a number of sold chicken and chicken price had a positive influence. The empirical results from the Binary option of market participation revealed that three variables (number of years in broiler chicken business, access to transport, and access to extension) and one variable (stock size) in rural and urban households respectively had positive signs, thereby, implying an increase in participation in the formal markets. On the other hand two variables; access to information and household size in rural and urban households respectively had negative associations, thus implying that an increase in any of these variables may be associated with a decrease in the formal market participation level. The study therefore, concludes that number of sold chicken and chicken price positively affect broiler chicken profitability however; household size have negative effect on the level of formal market participation among urban households. Therefore, it is recommended that smallholder broiler chicken farmers increase their stocking volumes and get amalgamated into cooperatives in order to be able to access formal markets; hence increased broiler chicken profits.
- Full Text:
- Date Issued: 2017
- Authors: Mphahama, Litsoanelo Evodiah
- Date: 2017
- Subjects: Broilers (Chickens)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8678 , vital:33423
- Description: Growth in global demand for broiler chicken meat has become tremendous, hence; as one segment of poultry, broiler chicken production has a privilege to highly contribute to nations’ nutritional demands because of the shorter productive age, with only 42 days needed to reach a marketable weight with a high rate of productivity. In fact; in developing countries the importance of broiler chickens to the national economy cannot be overemphasized, as it has become a popular industry especially for the smallholder farmers that have great contribution to the economies of their countries. However, it is difficult to see a bright future for smallholder broiler chicken farmers in this rapidly changing industry structure. A major concern is that this group of farmers faces severe constraints and challenges to taking advantage of mainstream market opportunities; a situation that would impede the success of the sector leading the farmers to exit the business. The aim of this study was to investigate factors challenging small-holder broiler chicken profitability and the choice of market channels used by these famers. The study was conducted in the Maseru district in Lesotho. Using availability sampling; 220 smallholder broiler chicken farming households were purposively selected. Data were obtained from secondary sources and by an administration of questionnaires from January until March 2016. Excel, XLSTAT and SPSS were used for analyzing the data. The descriptive findings of this study were applied to the biographical characteristics of the smallholder broiler chicken farmers. Ages, household size, marital status, occupation, source of credit and broiler chicken production system were determined using SPSS through graphs, mean and percentages. Findings from determining broiler chicken profitability revealed that a mean gross margin of M607.74 in the rural areas and M665.13 from the urban areas were obtained. The results indicated broiler chicken feeds and day old chicks as major operational costs in broiler chicken rearing. This study also explored factors that influence broiler chicken profitability on smallholder farmers. The results suggest that cost starter feeds, cost finisher feeds, transport cost and cost dox/doc negatively affected broiler chicken profits while a number of sold chicken and chicken price had a positive influence. The empirical results from the Binary option of market participation revealed that three variables (number of years in broiler chicken business, access to transport, and access to extension) and one variable (stock size) in rural and urban households respectively had positive signs, thereby, implying an increase in participation in the formal markets. On the other hand two variables; access to information and household size in rural and urban households respectively had negative associations, thus implying that an increase in any of these variables may be associated with a decrease in the formal market participation level. The study therefore, concludes that number of sold chicken and chicken price positively affect broiler chicken profitability however; household size have negative effect on the level of formal market participation among urban households. Therefore, it is recommended that smallholder broiler chicken farmers increase their stocking volumes and get amalgamated into cooperatives in order to be able to access formal markets; hence increased broiler chicken profits.
- Full Text:
- Date Issued: 2017