Language and access in the public healthcare system in South Africa with a particular focus on primary public health facilities in Grahamstown and Cofimvaba in the Eastern Cape
- Authors: Mhlauli, Nonceba
- Date: 2017
- Subjects: Health literacy -- South Africa -- Eastern Cape , Patient education -- South Africa -- Eastern Cape , Communication in medicine -- South Africa -- Eastern Cape , Health literacy -- Social aspects -- South Africa -- Eastern Cape , Poor -- Medical care -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/56692 , vital:26817
- Description: The right to language and the right to healthcare services are human rights which are enshrined in the Constitution of the Republic of South Africa. Section 6 (5) of the Constitution and Section 1.3 (b) and (e) of the Eastern Cape Provincial Language Policy provide protection against unfair discrimination on the grounds of language; while sections 30 and 31 (1) of the Constitution refer to people’s rights in terms of cultural, religious and linguistic participation. Section 27 (a) states that ‘everyone has the right to access to healthcare services’. In accordance with the Constitution, in 2011 the National Department of Health passed a Policy on Language Services. This policy aims to facilitate equitable access to government services and information, as well as respect for language rights as spelled out in the Constitution. The Policy on Language Services further aims to promote multilingualism in the National Department of Health and to allow people to access information in a language of their choice, understand important messages and the language necessary for informed and participatory decision making (Department of Health 2011:1). Given the above policy and Constitutional provisions as far as policy commitment is concerned, the crucial issue remains the implementation of such policy to ensure that the right to access to health and language are realised. The study provides an analysis of the Policy on Language Services 2011 as it relates to language rights and the delivery of health services, focusing on the roll out and implementation process and the public awareness of the policy. This study primarily focuses on the role language plays in accessing public healthcare in primary healthcare facilities in the Grahamstown and Cofimvaba. The study looked at communication between patient and healthcare providers and whether healthcare services were provided in the language of the patient or the language the patient knows best. This study further assessed indications of patients’ comprehension of information such as medical instructions on packaged medicine, comprehension of posters, pamphlets and health education sessions in order to fully participate in the process of their health status. The data of this research was collected from healthcare providers and patients in primary healthcare facilities in Grahamstown and Cofimvaba in the Eastern Cape. The research methods used was in-depth interviews, non-participant observations as well as content analysis such as sign/direction posts, medical labels and information boards. These methods were used to determine whether language plays a role in accessing quality healthcare services in these facilities. The research found that the lack of implementation of language and health policy resulted in the perpetuation of language barriers in the healthcare sector. The study therefore argues that adequate healthcare can only be provided if and when healthcare providers and patients are able to communicate with each other in the language they know best or feel most comfortable in. Thus meaning the implementation of the current Constitutional and policy provisions is crucial to language and access to healthcare services.
- Full Text:
- Authors: Mhlauli, Nonceba
- Date: 2017
- Subjects: Health literacy -- South Africa -- Eastern Cape , Patient education -- South Africa -- Eastern Cape , Communication in medicine -- South Africa -- Eastern Cape , Health literacy -- Social aspects -- South Africa -- Eastern Cape , Poor -- Medical care -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/56692 , vital:26817
- Description: The right to language and the right to healthcare services are human rights which are enshrined in the Constitution of the Republic of South Africa. Section 6 (5) of the Constitution and Section 1.3 (b) and (e) of the Eastern Cape Provincial Language Policy provide protection against unfair discrimination on the grounds of language; while sections 30 and 31 (1) of the Constitution refer to people’s rights in terms of cultural, religious and linguistic participation. Section 27 (a) states that ‘everyone has the right to access to healthcare services’. In accordance with the Constitution, in 2011 the National Department of Health passed a Policy on Language Services. This policy aims to facilitate equitable access to government services and information, as well as respect for language rights as spelled out in the Constitution. The Policy on Language Services further aims to promote multilingualism in the National Department of Health and to allow people to access information in a language of their choice, understand important messages and the language necessary for informed and participatory decision making (Department of Health 2011:1). Given the above policy and Constitutional provisions as far as policy commitment is concerned, the crucial issue remains the implementation of such policy to ensure that the right to access to health and language are realised. The study provides an analysis of the Policy on Language Services 2011 as it relates to language rights and the delivery of health services, focusing on the roll out and implementation process and the public awareness of the policy. This study primarily focuses on the role language plays in accessing public healthcare in primary healthcare facilities in the Grahamstown and Cofimvaba. The study looked at communication between patient and healthcare providers and whether healthcare services were provided in the language of the patient or the language the patient knows best. This study further assessed indications of patients’ comprehension of information such as medical instructions on packaged medicine, comprehension of posters, pamphlets and health education sessions in order to fully participate in the process of their health status. The data of this research was collected from healthcare providers and patients in primary healthcare facilities in Grahamstown and Cofimvaba in the Eastern Cape. The research methods used was in-depth interviews, non-participant observations as well as content analysis such as sign/direction posts, medical labels and information boards. These methods were used to determine whether language plays a role in accessing quality healthcare services in these facilities. The research found that the lack of implementation of language and health policy resulted in the perpetuation of language barriers in the healthcare sector. The study therefore argues that adequate healthcare can only be provided if and when healthcare providers and patients are able to communicate with each other in the language they know best or feel most comfortable in. Thus meaning the implementation of the current Constitutional and policy provisions is crucial to language and access to healthcare services.
- Full Text:
Malawi’s foreign policy decision-making: the 2012 Malawi-Tanzania boundary dispute
- Kaunda, Mapopa Charles Martin Sazamleke
- Authors: Kaunda, Mapopa Charles Martin Sazamleke
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/59225 , vital:27484
- Description: Expected release date-April 2019
- Full Text:
- Authors: Kaunda, Mapopa Charles Martin Sazamleke
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/59225 , vital:27484
- Description: Expected release date-April 2019
- Full Text:
Microbial water quality monitoring of raw and treated water sources in Harare and the effect of gender in disaster management due to water related disasters
- Authors: Chirenda, Tatenda Grace
- Date: 2017
- Subjects: Drinking water Microbiology Zimbabwe Harare , Heterotrophic bacteria Zimbabwe Harare , Emergency management Zimbabwe Harare , Disasters Social aspects Zimbabwe Harare , Water quality management Zimbabwe Harare , Public health Zimbabwe Harare , Sex role Zimbabwe Harare
- Language: English
- Type: text , Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/59156 , vital:27444
- Description: Background - Microbial water quality monitoring is essential to the provision of potable water for domestic use. Unsafe water sources increase the risk of waterborne diseases. There is a need to raise awareness of legislature that supports management of water related disasters. Gender, education, health, and economic vulnerability contribute to the success of disaster management. Aim - This study aimed to investigate the microbial water quality of treated water in the Harare area. The study also researched the microbial water quality monitoring practices in Zimbabwe and how these contribute to the management of water borne diseases. The impact of gender, marriage, education, and disease in disaster management practices in Zimbabwe and South Africa was analysed. Method - Literature review was conducted on microbial water quality monitoring practices in Zimbabwe and legislature that supports disaster management. Practices of disaster management in Zimbabwe, and South Africa were investigated and compared. The perspective of the Harare community on the quality of their potable water was investigated through the use of a questionnaire and water quality testing was conducted using hydrogen sulphide test and R2A based heterotrophic plate count. Raw water supplying Manyame River and tap water in Harare households were assessed for microbial quality. Results and Discussion - Raw water sources were found to be contaminated by faecal matter. Household water sources had no faecal contamination, but tested positive for heterotrophic bacteria. The CFU/ml quantities obtained ranged from 1- 452 CFU/ml for all samples. The WHO guidelines for domestic water sources recommend that domestic water should have no coliforms/100 ml sample. Disaster management protocols were available in disaster prone areas such as the Matabeleland South Province. No guidelines were in place for monitoring microbial water quality as a disaster prevention method. Conclusion - The current state of treated water supplied by the Morton Jaffray Treatment Plant was found to be suitable for domestic use, but not sufficient to meet the Harare population’s needs. The need to push for legislature supporting microbial water quality monitoring was recognised. Initiating public / private partnerships in water distribution and water quality monitoring in Zimbabwe was encouraged.
- Full Text:
- Authors: Chirenda, Tatenda Grace
- Date: 2017
- Subjects: Drinking water Microbiology Zimbabwe Harare , Heterotrophic bacteria Zimbabwe Harare , Emergency management Zimbabwe Harare , Disasters Social aspects Zimbabwe Harare , Water quality management Zimbabwe Harare , Public health Zimbabwe Harare , Sex role Zimbabwe Harare
- Language: English
- Type: text , Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/59156 , vital:27444
- Description: Background - Microbial water quality monitoring is essential to the provision of potable water for domestic use. Unsafe water sources increase the risk of waterborne diseases. There is a need to raise awareness of legislature that supports management of water related disasters. Gender, education, health, and economic vulnerability contribute to the success of disaster management. Aim - This study aimed to investigate the microbial water quality of treated water in the Harare area. The study also researched the microbial water quality monitoring practices in Zimbabwe and how these contribute to the management of water borne diseases. The impact of gender, marriage, education, and disease in disaster management practices in Zimbabwe and South Africa was analysed. Method - Literature review was conducted on microbial water quality monitoring practices in Zimbabwe and legislature that supports disaster management. Practices of disaster management in Zimbabwe, and South Africa were investigated and compared. The perspective of the Harare community on the quality of their potable water was investigated through the use of a questionnaire and water quality testing was conducted using hydrogen sulphide test and R2A based heterotrophic plate count. Raw water supplying Manyame River and tap water in Harare households were assessed for microbial quality. Results and Discussion - Raw water sources were found to be contaminated by faecal matter. Household water sources had no faecal contamination, but tested positive for heterotrophic bacteria. The CFU/ml quantities obtained ranged from 1- 452 CFU/ml for all samples. The WHO guidelines for domestic water sources recommend that domestic water should have no coliforms/100 ml sample. Disaster management protocols were available in disaster prone areas such as the Matabeleland South Province. No guidelines were in place for monitoring microbial water quality as a disaster prevention method. Conclusion - The current state of treated water supplied by the Morton Jaffray Treatment Plant was found to be suitable for domestic use, but not sufficient to meet the Harare population’s needs. The need to push for legislature supporting microbial water quality monitoring was recognised. Initiating public / private partnerships in water distribution and water quality monitoring in Zimbabwe was encouraged.
- Full Text:
Middle management communication in the midst of a crisis
- Authors: Mbolekwano, Veliswa A
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/52477 , vital:26194
- Description: Crisis communication by organisational top leadership to external stakeholders has been explored in literature, while internal crisis communication dynamics by middle managers with their employees within the organisation has been under studied. This paper pursues an understanding of crisis communication dynamics between middle management and their subordinates by investigating how the Middle Managers/Team Leaders of Makana Brick Manufacturing Firm (MBMF) communicated with their employees in the midst of the Eskom load shedding crisis in 2014. The investigation is not limited only to how they handled or made sense of the crisis, but also examines the effect and efficiency of their daily communication on both employees (subordinates) and operations in pursuing this end. As a foundation and background, the study broadly explores the literature on Crisis Leadership, Crisis and Crisis Communication, which are critical topics to understanding the communication role of the middle managers who were the primary subject of this research. The research was conducted through semi-structured, face-to-face interviews. Nine Team Leaders were interviewed. The data collected was transcribed verbatim and analysed through open coding. In the literature of crisis management, the concept of crisis communication has been extensively examined as a function of crisis management, primarily with regards to the crisis communication strategy, encompassing the actual verbal and nonverbal responses an organisation uses to address a crisis. The findings are generally congruent with the crisis communication literature, and reinforce the importance of efficient internal communication in building a culture of transparency between management and employees, as espoused in the literature reviewed, which in addition presents an invaluable opportunity for employees across all levels to engage in and be informed of the organisation’s priorities and therefore has the potential to dictate the success or failure of any major change or crisis situation. As such, it can be argued that there is a need for the same analytical rigour that is given to external crisis communication to be given to financial or operational measures (Barrett, 2002). For both external and internal stakeholders, human compassion, concern and empathy; faith in legitimate and appropriate actions taken by the chosen organisation spokesperson; and honesty, candidness and openness in communication (Seeger 2006, p. 242) are universal. The quality and the quantity of communication, essentially, affect the level of trust and involvement of employees (Thomas, Zolin & Hartman, 2009), which is particularly relevant in times of crisis (Mazzei & Ravazzani, 2015 p. 322). Trust must be developed with staff through clear, honest communication and transparent actions. These encompass being fair, open in communication and intentions, showing consistency, fulfilling promises and being honest about what middle managers can and cannot communicate to their employees (Farrel & Schlesinger, 2013, p. 125). In this study, face to face communication proved to be the most preferred communication channel because of its rewarding advantages such as direct feedback, two-way communication, relationship building and project collaboration.
- Full Text:
- Authors: Mbolekwano, Veliswa A
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/52477 , vital:26194
- Description: Crisis communication by organisational top leadership to external stakeholders has been explored in literature, while internal crisis communication dynamics by middle managers with their employees within the organisation has been under studied. This paper pursues an understanding of crisis communication dynamics between middle management and their subordinates by investigating how the Middle Managers/Team Leaders of Makana Brick Manufacturing Firm (MBMF) communicated with their employees in the midst of the Eskom load shedding crisis in 2014. The investigation is not limited only to how they handled or made sense of the crisis, but also examines the effect and efficiency of their daily communication on both employees (subordinates) and operations in pursuing this end. As a foundation and background, the study broadly explores the literature on Crisis Leadership, Crisis and Crisis Communication, which are critical topics to understanding the communication role of the middle managers who were the primary subject of this research. The research was conducted through semi-structured, face-to-face interviews. Nine Team Leaders were interviewed. The data collected was transcribed verbatim and analysed through open coding. In the literature of crisis management, the concept of crisis communication has been extensively examined as a function of crisis management, primarily with regards to the crisis communication strategy, encompassing the actual verbal and nonverbal responses an organisation uses to address a crisis. The findings are generally congruent with the crisis communication literature, and reinforce the importance of efficient internal communication in building a culture of transparency between management and employees, as espoused in the literature reviewed, which in addition presents an invaluable opportunity for employees across all levels to engage in and be informed of the organisation’s priorities and therefore has the potential to dictate the success or failure of any major change or crisis situation. As such, it can be argued that there is a need for the same analytical rigour that is given to external crisis communication to be given to financial or operational measures (Barrett, 2002). For both external and internal stakeholders, human compassion, concern and empathy; faith in legitimate and appropriate actions taken by the chosen organisation spokesperson; and honesty, candidness and openness in communication (Seeger 2006, p. 242) are universal. The quality and the quantity of communication, essentially, affect the level of trust and involvement of employees (Thomas, Zolin & Hartman, 2009), which is particularly relevant in times of crisis (Mazzei & Ravazzani, 2015 p. 322). Trust must be developed with staff through clear, honest communication and transparent actions. These encompass being fair, open in communication and intentions, showing consistency, fulfilling promises and being honest about what middle managers can and cannot communicate to their employees (Farrel & Schlesinger, 2013, p. 125). In this study, face to face communication proved to be the most preferred communication channel because of its rewarding advantages such as direct feedback, two-way communication, relationship building and project collaboration.
- Full Text:
Mineralogical and geochemical constraints on the origin, alteration history and metallogenic significance of the Manganore iron-formation, Northern Cape Province, South Africa
- Authors: Papadopoulos, Vlassis
- Date: 2017
- Subjects: Banded iron formation , Transvaal Supergroup (South Africa) , Groups (Stratigraphy) South Africa , Lithostratigraphy , Petrology South Africa , Geochemistry South Africa
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/65189 , vital:28702
- Description: The Manganore iron-formation (MIF) of the Transvaal Supergroup is host to the most important high-grade iron ore bodies in South Africa. Prevailing models for ore genesis invoke supergene processes performing during a long period of erosion, oxidation and weathering under tropical lateritic conditions while the role of potential hydrothermal processes is not addressed. Lack of detailed petrographical and geochemical data necessitated reexamination of the MIF through new and existing drill core exploration material. Thorough petrographical investigation revealed a multi-event complex alteration history involving hydrothermal activity. Iron and silica mobility during alteration is demonstrated by a series of replacement, overprinting, crosscutting textures, extensive silicification and hematitization. Metasomatized textures such as pseudomorphs of primary magnetite, carbonate minerals and chert pods/lenses point to an alteration occurring in layer- controlled fronts and link stratigraphically the MIF to Kuruman and Griquatown iron- formations. Whole-rock geochemical data verify textural observations suggesting strong enrichment of iron or silica in meter-scale horizons, expressed by different generations of quartz and hematite. High-grade iron ore is highly enriched in TiO2 and Al2O3 compared to the protolith while both BIF and iron ore display highly increased concentrations of trace elements (transition metals and HFSE). Oxygen isotopes from different quartz textures reveal little to none isotopic exchangement during alteration whereas O isotopes from hematite are in concert to values from literature and suggest two different generations of hematite. A total of 20 minerals apart from quartz and hematite were documented. An earlier alkali/HFSE alteration event that is believed to have affected the overlying Gamagara shales is recorded in the BIF by the presence of muscovite, apatite, rutile, zircon and xenotime. A later and possibly ongoing event of succeeding hydrothermal pulses involves mainly sulphates (gypsum, baryte, celestine), pyrite, carbonates (siderite, calcite) and silicates (berthierine and tourmaline). Alkali-bearing brines persistently exploit the BIF mainly through karstification-related secondary porosity, are evidently carrying iron and are proposed to participate in or control the iron enrichment by facilitating removal of silica. The source of metals, sulfur and carbon is attributed to the underlying Campbellrand dolomites and especially to the upper Gamogaan Formation. The unconformable contact between BIF and the overlying shales is suggested as a suitable fluid conduit for the development of the observed BIF and shale-derived high-grade hematite iron ore.
- Full Text:
- Authors: Papadopoulos, Vlassis
- Date: 2017
- Subjects: Banded iron formation , Transvaal Supergroup (South Africa) , Groups (Stratigraphy) South Africa , Lithostratigraphy , Petrology South Africa , Geochemistry South Africa
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/65189 , vital:28702
- Description: The Manganore iron-formation (MIF) of the Transvaal Supergroup is host to the most important high-grade iron ore bodies in South Africa. Prevailing models for ore genesis invoke supergene processes performing during a long period of erosion, oxidation and weathering under tropical lateritic conditions while the role of potential hydrothermal processes is not addressed. Lack of detailed petrographical and geochemical data necessitated reexamination of the MIF through new and existing drill core exploration material. Thorough petrographical investigation revealed a multi-event complex alteration history involving hydrothermal activity. Iron and silica mobility during alteration is demonstrated by a series of replacement, overprinting, crosscutting textures, extensive silicification and hematitization. Metasomatized textures such as pseudomorphs of primary magnetite, carbonate minerals and chert pods/lenses point to an alteration occurring in layer- controlled fronts and link stratigraphically the MIF to Kuruman and Griquatown iron- formations. Whole-rock geochemical data verify textural observations suggesting strong enrichment of iron or silica in meter-scale horizons, expressed by different generations of quartz and hematite. High-grade iron ore is highly enriched in TiO2 and Al2O3 compared to the protolith while both BIF and iron ore display highly increased concentrations of trace elements (transition metals and HFSE). Oxygen isotopes from different quartz textures reveal little to none isotopic exchangement during alteration whereas O isotopes from hematite are in concert to values from literature and suggest two different generations of hematite. A total of 20 minerals apart from quartz and hematite were documented. An earlier alkali/HFSE alteration event that is believed to have affected the overlying Gamagara shales is recorded in the BIF by the presence of muscovite, apatite, rutile, zircon and xenotime. A later and possibly ongoing event of succeeding hydrothermal pulses involves mainly sulphates (gypsum, baryte, celestine), pyrite, carbonates (siderite, calcite) and silicates (berthierine and tourmaline). Alkali-bearing brines persistently exploit the BIF mainly through karstification-related secondary porosity, are evidently carrying iron and are proposed to participate in or control the iron enrichment by facilitating removal of silica. The source of metals, sulfur and carbon is attributed to the underlying Campbellrand dolomites and especially to the upper Gamogaan Formation. The unconformable contact between BIF and the overlying shales is suggested as a suitable fluid conduit for the development of the observed BIF and shale-derived high-grade hematite iron ore.
- Full Text:
Nonlinear optical properties of Sn(IV) phthalocyanines: experimental and theoretical approach
- Authors: Louzada, Marcel Severiano
- Date: 2017
- Subjects: Phthalocyanines , Nonlinear optics
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/57852 , vital:26996
- Description: This work presents the nonlinear properties of six Sn(IV) Phthalocyanines. Three of the phthalocyanines are linked by an alkylthiol substituent and the rest are linked with a phenoxy substituent. For all six compounds non-linear optic analysis was carried out in four solvents: chloroform, toluene, dichloromethane, and tetrahydrofuran, and their differences were recorded. Calculation of the linear, singlet excited, triplet excited and two photon absorption cross-sections were also carried out and the results compared. To form a comparison the first order hyperpolarizabilities, DFT calculations were also performed and the results compared to see if the behaviour between the two properties can be predicted using DFT.
- Full Text:
- Authors: Louzada, Marcel Severiano
- Date: 2017
- Subjects: Phthalocyanines , Nonlinear optics
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/57852 , vital:26996
- Description: This work presents the nonlinear properties of six Sn(IV) Phthalocyanines. Three of the phthalocyanines are linked by an alkylthiol substituent and the rest are linked with a phenoxy substituent. For all six compounds non-linear optic analysis was carried out in four solvents: chloroform, toluene, dichloromethane, and tetrahydrofuran, and their differences were recorded. Calculation of the linear, singlet excited, triplet excited and two photon absorption cross-sections were also carried out and the results compared. To form a comparison the first order hyperpolarizabilities, DFT calculations were also performed and the results compared to see if the behaviour between the two properties can be predicted using DFT.
- Full Text:
Oxygen limitation and thermal tolerance: a comparison of pulmonate and patellogastropod limpets
- Authors: Kankondi, Sebbi
- Date: 2017
- Subjects: Thermal tolerance (Physiology) , Limpets -- Physiology , Limpets -- Effect of temperature on , Oxygen consumption (Physiology)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/7570 , vital:21274
- Description: Since the scientific community anticipates a general change in the global climate, it has become increasingly important to develop predictive models which encompass mechanisms to generate reliable forecasts of the effects this change on ecological communities and processes. To this end, the oxygen- and capacity- limited thermal tolerance (OCLTT) theory has been developed as a link between various physiological processes, the thermal aspect of climate change and the associated shifts at different levels of biological organization. This study set out to assess the general applicability of the OCLTT theory in eurythermal pulmonate and patellogastropod limpets, whose distributions overlap on the high shore rocks of the warm temperate, south-east coast of South Africa.This was done by determining their microhabitat use, median lethal temperatures and cardiac, Arrhenius breakpoint temperatures as measures of their upper thermal tolerance limits, in both air and water. The main hypotheses of the study were that the pulmonate limpets would be more common than the patellogastropods in warmer microhabitats during low tide and would have higher thermal limits than the patellogastropods in air and vice versa in water. This was based on the assumption that the two limpet groups have different capabilities of oxygen consumption in air and water, due to differences in their respiratory organs and that this would be reflected in their thermal tolerances based on predictions made by the OCLTT. This assumption was important because oxygen consumption was not measured in this study. Previous research (e.g. Garrity, 1984), showed that a thermal stress gradient exists among rocky intertidal microhabitats. From most to least thermally stressful the gradient is horizontal surfaces> slopes> vertical surfaces> tide pools> crevices. The current study found that, while the pulmonate limpets, Siphonaria capensis and S. serrata, preferred rock pools, sloped, vertical and horizontal rock surfaces, the patellogastropod limpets, Cellana capensis and Scutellastra granularis, preferred rock pools and vertical rock surfaces. Furthermore, the pulmonate limpets were only common on horizontal rock surfaces where specific ameliorating conditions would have mitigated thermal stress there. In addition, C. capensis had similar thermal tolerance limits to the pulmonate limpets in air and the pulmonate limpets had similar and/or higher thermal tolerance limits compared to S. granularis in water. This indicates that the pulmonate limpets did not necessarily prefer warmer microhabitats than the patellogastropod limpets and that there were no differences in the collective upper thermal tolerance limits between the two limpet groups in either medium.Consequently, there was no indication from this study that an assumed superior capacity for oxygen supply translates into greater thermal tolerance and that the hypotheses based on the OCLTT were not supported. Although this was an indirect test of the OCLTT theory, I conclude that this study does not support the notion of its general applicability and that mechanisms other than those outlined by the OCLTT theory may help explain the patterns of thermal limitation observed in the current study.
- Full Text:
- Authors: Kankondi, Sebbi
- Date: 2017
- Subjects: Thermal tolerance (Physiology) , Limpets -- Physiology , Limpets -- Effect of temperature on , Oxygen consumption (Physiology)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/7570 , vital:21274
- Description: Since the scientific community anticipates a general change in the global climate, it has become increasingly important to develop predictive models which encompass mechanisms to generate reliable forecasts of the effects this change on ecological communities and processes. To this end, the oxygen- and capacity- limited thermal tolerance (OCLTT) theory has been developed as a link between various physiological processes, the thermal aspect of climate change and the associated shifts at different levels of biological organization. This study set out to assess the general applicability of the OCLTT theory in eurythermal pulmonate and patellogastropod limpets, whose distributions overlap on the high shore rocks of the warm temperate, south-east coast of South Africa.This was done by determining their microhabitat use, median lethal temperatures and cardiac, Arrhenius breakpoint temperatures as measures of their upper thermal tolerance limits, in both air and water. The main hypotheses of the study were that the pulmonate limpets would be more common than the patellogastropods in warmer microhabitats during low tide and would have higher thermal limits than the patellogastropods in air and vice versa in water. This was based on the assumption that the two limpet groups have different capabilities of oxygen consumption in air and water, due to differences in their respiratory organs and that this would be reflected in their thermal tolerances based on predictions made by the OCLTT. This assumption was important because oxygen consumption was not measured in this study. Previous research (e.g. Garrity, 1984), showed that a thermal stress gradient exists among rocky intertidal microhabitats. From most to least thermally stressful the gradient is horizontal surfaces> slopes> vertical surfaces> tide pools> crevices. The current study found that, while the pulmonate limpets, Siphonaria capensis and S. serrata, preferred rock pools, sloped, vertical and horizontal rock surfaces, the patellogastropod limpets, Cellana capensis and Scutellastra granularis, preferred rock pools and vertical rock surfaces. Furthermore, the pulmonate limpets were only common on horizontal rock surfaces where specific ameliorating conditions would have mitigated thermal stress there. In addition, C. capensis had similar thermal tolerance limits to the pulmonate limpets in air and the pulmonate limpets had similar and/or higher thermal tolerance limits compared to S. granularis in water. This indicates that the pulmonate limpets did not necessarily prefer warmer microhabitats than the patellogastropod limpets and that there were no differences in the collective upper thermal tolerance limits between the two limpet groups in either medium.Consequently, there was no indication from this study that an assumed superior capacity for oxygen supply translates into greater thermal tolerance and that the hypotheses based on the OCLTT were not supported. Although this was an indirect test of the OCLTT theory, I conclude that this study does not support the notion of its general applicability and that mechanisms other than those outlined by the OCLTT theory may help explain the patterns of thermal limitation observed in the current study.
- Full Text:
Population genomics analysis of yellowfin tuna Thunnus albacares off South Africa reveals need for a shifted management boundary
- Authors: Mullins, Rachel Brenna
- Date: 2017
- Subjects: Yellowfin tuna fisheries -- South Africa -- Western Cape , Genomics , Tuna fisheries -- South Africa , Fishery management -- South Africa
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/57819 , vital:26992
- Description: Yellowfin tuna Thunnus albacares is a commercially and economically important fisheries species, which comprises the second largest component of South Africa’s catch of tuna and tuna-like species. Catches of the species off South Africa are treated as two discrete stocks by the two tuna Regional Fisheries Management Organisations (tRFMOs) under whose jurisdictions they fall. Individuals caught off the Western Cape, west of the boundary between the tRFMOs at 20°E, are included in assessment and management of the Atlantic Ocean yellowfin tuna stock by the International Commission for the Conservation of Atlantic Tunas (ICCAT), and those caught east of this boundary are assessed and managed as part of the Indian Ocean stock by the Indian Ocean Tuna Commission (IOTC). The boundary between these stocks is based on the confluence of the two oceans in this region and does not incorporate the population structure of species. For sustainable exploitation of fisheries resources, it is important that the definition of management stocks reflects species’ biological population structure; the fine-scale stock structure of yellowfin tuna off South Africa is therefore a research priority which this study aimed to address by means of population genomics analyses. Yellowfin tuna exhibit shallow genetic differentiation over wide geographic areas, and as such traditional population genetic approaches have limited power in resolving fishery significant population structure in the species. Herein, a population genomic approach was employed, specifically, genome-wide analysis of single nucleotide polymorphisms (SNPs) discovered using a next-generation DNA sequencing approach, to confer (i) increased statistical power to detect neutral structuring reflecting population connectivity patterns and (ii) signatures of local adaptation. The mitochondrial Control Region (mtDNA CR) was also sequenced to compare the resolving power of different approaches and to permit coalescent based analyses of the species evolutionary history in the region. Neutral SNP loci revealed significant structure within the dataset (Fst=0.0043; P<0.0001); partitioning of this differentiation within the dataset indicated significant differentiation between yellowfin tuna from the Western Cape and the Gulf of Guinea in the eastern Atlantic Ocean, with no significant differentiation between individuals from the Western Cape and Western Indian Ocean regions. This indicates two population units wherein there is a separation of the Gulf of Guinea from the remaining samples (Indian Ocean including Western Cape) that are largely derived from a single genetic population. This pattern was also supported by assignment tests. Positive outlier SNPs, exhibiting signatures of diversifying selection, suggest that individuals from these regions may be locally adapted, as well as demographically isolated. The mtDNA CR did not reveal any significant genetic structure among samples (Fst=0.0030; P=0.309), demonstrating the increased resolving power provided by population genomics approaches, but revealed signatures of historical demographic fluctuations associated with glacial cycles. Based on the findings of this study, it is suggested that yellowfin tuna caught off the Western Cape of South Africa are migrants from the Indian Ocean population, exhibiting significant genetic differentiation from the Atlantic Ocean Gulf of Guinea individuals, and should thus be included in the assessment and management of the Indian Ocean stock. It is therefore recommended that the boundary between the Atlantic and Indian Ocean yellowfin tuna stocks, under the mandates of ICCAT and the IOTC respectively, should be shifted to approximately 13.35°E to include all individuals caught in South African waters in the Indian Ocean stock.
- Full Text:
- Authors: Mullins, Rachel Brenna
- Date: 2017
- Subjects: Yellowfin tuna fisheries -- South Africa -- Western Cape , Genomics , Tuna fisheries -- South Africa , Fishery management -- South Africa
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/57819 , vital:26992
- Description: Yellowfin tuna Thunnus albacares is a commercially and economically important fisheries species, which comprises the second largest component of South Africa’s catch of tuna and tuna-like species. Catches of the species off South Africa are treated as two discrete stocks by the two tuna Regional Fisheries Management Organisations (tRFMOs) under whose jurisdictions they fall. Individuals caught off the Western Cape, west of the boundary between the tRFMOs at 20°E, are included in assessment and management of the Atlantic Ocean yellowfin tuna stock by the International Commission for the Conservation of Atlantic Tunas (ICCAT), and those caught east of this boundary are assessed and managed as part of the Indian Ocean stock by the Indian Ocean Tuna Commission (IOTC). The boundary between these stocks is based on the confluence of the two oceans in this region and does not incorporate the population structure of species. For sustainable exploitation of fisheries resources, it is important that the definition of management stocks reflects species’ biological population structure; the fine-scale stock structure of yellowfin tuna off South Africa is therefore a research priority which this study aimed to address by means of population genomics analyses. Yellowfin tuna exhibit shallow genetic differentiation over wide geographic areas, and as such traditional population genetic approaches have limited power in resolving fishery significant population structure in the species. Herein, a population genomic approach was employed, specifically, genome-wide analysis of single nucleotide polymorphisms (SNPs) discovered using a next-generation DNA sequencing approach, to confer (i) increased statistical power to detect neutral structuring reflecting population connectivity patterns and (ii) signatures of local adaptation. The mitochondrial Control Region (mtDNA CR) was also sequenced to compare the resolving power of different approaches and to permit coalescent based analyses of the species evolutionary history in the region. Neutral SNP loci revealed significant structure within the dataset (Fst=0.0043; P<0.0001); partitioning of this differentiation within the dataset indicated significant differentiation between yellowfin tuna from the Western Cape and the Gulf of Guinea in the eastern Atlantic Ocean, with no significant differentiation between individuals from the Western Cape and Western Indian Ocean regions. This indicates two population units wherein there is a separation of the Gulf of Guinea from the remaining samples (Indian Ocean including Western Cape) that are largely derived from a single genetic population. This pattern was also supported by assignment tests. Positive outlier SNPs, exhibiting signatures of diversifying selection, suggest that individuals from these regions may be locally adapted, as well as demographically isolated. The mtDNA CR did not reveal any significant genetic structure among samples (Fst=0.0030; P=0.309), demonstrating the increased resolving power provided by population genomics approaches, but revealed signatures of historical demographic fluctuations associated with glacial cycles. Based on the findings of this study, it is suggested that yellowfin tuna caught off the Western Cape of South Africa are migrants from the Indian Ocean population, exhibiting significant genetic differentiation from the Atlantic Ocean Gulf of Guinea individuals, and should thus be included in the assessment and management of the Indian Ocean stock. It is therefore recommended that the boundary between the Atlantic and Indian Ocean yellowfin tuna stocks, under the mandates of ICCAT and the IOTC respectively, should be shifted to approximately 13.35°E to include all individuals caught in South African waters in the Indian Ocean stock.
- Full Text:
Post-release evaluation of the biological control programme against Cereus jamacaru De Candolle (Cactaceae), in South Africa
- Authors: Sutton, Guy Frederick
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/7982 , vital:21330
- Description: Cereus jamacaru De Candolle (Cactaceae) is an environment-transforming weed of both agricultural and wildlife habitats in South Africa. Weed infestations reduce carrying capacity of the land, and pose a risk to livestock, wildlife and human safety due to the plant’s spiny thorns. The weed is considered to be under complete biological control in South Africa, due to its introduced control agent, Hypogeococcus festerianus Lizer y Trelles (Hemiptera: Pseudococcidae), although observational reports suggest that the level of success achieved is variable. In this thesis, a formal post-release evaluation of this biological control programme was conducted, specifically to determine the efficacy of H. festerianus as a biological control agent, and to identify factors which may limit or constrain the level of success achieved by the control agent. These data were collected with the intention of improving the control of C. jamacaru in South Africa. A field-based study of C. jamacaru population demographics investigated the efficacy of H. festerianus as a biological control agent of the weed, by integrating weed growth, fecundity and survival metrics with C. jamacaru population dynamics and demographic patterns from 8 sites where H. festerianus was present and 14 sites where the control agent was absent. The findings indicated that H. festerianus significantly reduced weed fecundity, which resulted in fewer seedling recruits, and that levels of plant mortality were greater at sites where H. festerianus was present. The reduction in weed fecundity and survival translated into negative population-level consequences for H. festerianus. Weed-population age frequency distributions in the absence of H. festerianus demonstrated a “reverse J-shaped” distribution, indicative of high recruitment rates and population stability, while C. jamacaru populations infected with H. festerianus were described by bell-shaped distributions, and were typified by limited recruitment, or a complete lack thereof. By constraining recruitment and inhibiting selfregeneration, H. festerianus appears to regulate populations of C. jamacaru. Predation and parasitism of H. festerianus was believed to be a limiting factor for the biological control programme against C. jamacaru in South Africa, although no formal evaluation of this claim had been undertaken. Accordingly, the assemblage of natural enemies acquired by H. festerianus in South Africa was identified by field-collections of infected H. festerianus gall-material. Further, timed point-count surveys of natural enemies associated with H. festerianus were performed and integrated with the data on the impact of H. festerianus on weed population dynamics to assess the impact of two prominent predaceous taxa on H. festerianus efficacy as a biological control agent. Although H. festerianus had acquired a diverse suite of novel natural enemies in South Africa, this has not prevented the biocontrol agent from having an impact on C. jamacaru populations, although other subtler effects cannot be ruled out. This study showed that biological control efforts employing H. festerianus for the management of C. jamacaru have been successful. Furthermore, these data demonstrated the utility of retrospective analyses in developing and improving the science of biological control, specifically how to improve candidate agent prioritisation, determining how many agents are required for successful biological control, and how to evaluate the success of biological control efforts. Improvements in our theoretical understanding of biological control will undoubtedly reduce costs of biological control programmes, improve success rates, and increase the predictability of biological control.
- Full Text:
- Authors: Sutton, Guy Frederick
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/7982 , vital:21330
- Description: Cereus jamacaru De Candolle (Cactaceae) is an environment-transforming weed of both agricultural and wildlife habitats in South Africa. Weed infestations reduce carrying capacity of the land, and pose a risk to livestock, wildlife and human safety due to the plant’s spiny thorns. The weed is considered to be under complete biological control in South Africa, due to its introduced control agent, Hypogeococcus festerianus Lizer y Trelles (Hemiptera: Pseudococcidae), although observational reports suggest that the level of success achieved is variable. In this thesis, a formal post-release evaluation of this biological control programme was conducted, specifically to determine the efficacy of H. festerianus as a biological control agent, and to identify factors which may limit or constrain the level of success achieved by the control agent. These data were collected with the intention of improving the control of C. jamacaru in South Africa. A field-based study of C. jamacaru population demographics investigated the efficacy of H. festerianus as a biological control agent of the weed, by integrating weed growth, fecundity and survival metrics with C. jamacaru population dynamics and demographic patterns from 8 sites where H. festerianus was present and 14 sites where the control agent was absent. The findings indicated that H. festerianus significantly reduced weed fecundity, which resulted in fewer seedling recruits, and that levels of plant mortality were greater at sites where H. festerianus was present. The reduction in weed fecundity and survival translated into negative population-level consequences for H. festerianus. Weed-population age frequency distributions in the absence of H. festerianus demonstrated a “reverse J-shaped” distribution, indicative of high recruitment rates and population stability, while C. jamacaru populations infected with H. festerianus were described by bell-shaped distributions, and were typified by limited recruitment, or a complete lack thereof. By constraining recruitment and inhibiting selfregeneration, H. festerianus appears to regulate populations of C. jamacaru. Predation and parasitism of H. festerianus was believed to be a limiting factor for the biological control programme against C. jamacaru in South Africa, although no formal evaluation of this claim had been undertaken. Accordingly, the assemblage of natural enemies acquired by H. festerianus in South Africa was identified by field-collections of infected H. festerianus gall-material. Further, timed point-count surveys of natural enemies associated with H. festerianus were performed and integrated with the data on the impact of H. festerianus on weed population dynamics to assess the impact of two prominent predaceous taxa on H. festerianus efficacy as a biological control agent. Although H. festerianus had acquired a diverse suite of novel natural enemies in South Africa, this has not prevented the biocontrol agent from having an impact on C. jamacaru populations, although other subtler effects cannot be ruled out. This study showed that biological control efforts employing H. festerianus for the management of C. jamacaru have been successful. Furthermore, these data demonstrated the utility of retrospective analyses in developing and improving the science of biological control, specifically how to improve candidate agent prioritisation, determining how many agents are required for successful biological control, and how to evaluate the success of biological control efforts. Improvements in our theoretical understanding of biological control will undoubtedly reduce costs of biological control programmes, improve success rates, and increase the predictability of biological control.
- Full Text:
Preparation and evaluation of captopril - ion exchange resin complexes
- Chikukwa, Mellisa Tafadzwa Ruramai
- Authors: Chikukwa, Mellisa Tafadzwa Ruramai
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/59146 , vital:27441
- Description: Restricted access-thesis embargoed for 2 years
- Full Text:
- Authors: Chikukwa, Mellisa Tafadzwa Ruramai
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/59146 , vital:27441
- Description: Restricted access-thesis embargoed for 2 years
- Full Text:
Regulation of cell biology by extracellular species of the Hsp90- Hsp70 organising protein (Hop)
- Authors: Höft, Maxine Allison
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/59199 , vital:27465
- Description: Expected release date-April 2019
- Full Text:
- Authors: Höft, Maxine Allison
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/59199 , vital:27465
- Description: Expected release date-April 2019
- Full Text:
Release success of captive bred Cape Vultures (Gyps coprotheres) in the Magaliesberg Mountains, South Africa
- Authors: Hirschauer, Maggie
- Date: 2017
- Subjects: Vultures -- South Africa -- Magaliesburg , Vultures -- South Africa -- Behavior
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/4743 , vital:20720
- Description: The Cape Vulture, Gyps coprotheres, is currently classified as ‘endangered’. Endemic to southern Africa, its population has declined continuously over the past 40 years. The species is facing multiple anthropogenic threats. Notably, birds frequently collide with power lines and some cannot be released after treatment. This has led to the establishment of a captive breeding population with the hope that captive bred young can supplement wild populations and re-establish a now- abandoned breeding colony in the Magaliesberg Mountains, South Africa. This study aimed to follow the breeding behaviours of the captive colony and assess the appropriateness of chick rearing conditions. The study also aimed to monitor the behaviour, physical condition and dispersal of ten captive bred vultures after release in relation to their age. Behavioural observations of captive adult breeding and parental behaviours were conducted to establish whether chicks developed under comparable conditions to wild chicks. A high percentage of total colony copulation attempts (22 %) were extra-pair copulations. Four paired males formed ephemeral extra-pair relationships, two of which were homosexual. Chicks fledged earlier than wild chicks, on average at 128 days old. Wild and captive bred birds were observed at carcasses to compare competitive and feeding behaviours. Older birds, both wild and captive, fed the most efficiently. Preliminary evidence suggests females are more dominant and have higher display rates than males. Captive bred juvenile and four year old birds’ competitive and feeding behaviours (interaction rate, feeding rate, display rate, dominance, aggressiveness, and feeding efficiency) were the closest to, but still generally below, average values for same-aged wild birds. An index of body condition, body mass, and the prevalence of fault bars on the rectrices were used to assess their physical condition. After eight months, none of the ten birds had moved more than 8 km from the release site, nor had they foraged away from the vulture restaurant on site. Although altitude records of > 3100 m were recorded, their flight skills seemed inadequate. Future management considerations include the initiation of a pre-release exercise regime, the establishment of an acclimatization enclosure removed from the breeding site, and a varied or reduced post-release feeding schedule. Fledglings should be relocated and housed at the release enclosure until they are four years old.
- Full Text:
- Authors: Hirschauer, Maggie
- Date: 2017
- Subjects: Vultures -- South Africa -- Magaliesburg , Vultures -- South Africa -- Behavior
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/4743 , vital:20720
- Description: The Cape Vulture, Gyps coprotheres, is currently classified as ‘endangered’. Endemic to southern Africa, its population has declined continuously over the past 40 years. The species is facing multiple anthropogenic threats. Notably, birds frequently collide with power lines and some cannot be released after treatment. This has led to the establishment of a captive breeding population with the hope that captive bred young can supplement wild populations and re-establish a now- abandoned breeding colony in the Magaliesberg Mountains, South Africa. This study aimed to follow the breeding behaviours of the captive colony and assess the appropriateness of chick rearing conditions. The study also aimed to monitor the behaviour, physical condition and dispersal of ten captive bred vultures after release in relation to their age. Behavioural observations of captive adult breeding and parental behaviours were conducted to establish whether chicks developed under comparable conditions to wild chicks. A high percentage of total colony copulation attempts (22 %) were extra-pair copulations. Four paired males formed ephemeral extra-pair relationships, two of which were homosexual. Chicks fledged earlier than wild chicks, on average at 128 days old. Wild and captive bred birds were observed at carcasses to compare competitive and feeding behaviours. Older birds, both wild and captive, fed the most efficiently. Preliminary evidence suggests females are more dominant and have higher display rates than males. Captive bred juvenile and four year old birds’ competitive and feeding behaviours (interaction rate, feeding rate, display rate, dominance, aggressiveness, and feeding efficiency) were the closest to, but still generally below, average values for same-aged wild birds. An index of body condition, body mass, and the prevalence of fault bars on the rectrices were used to assess their physical condition. After eight months, none of the ten birds had moved more than 8 km from the release site, nor had they foraged away from the vulture restaurant on site. Although altitude records of > 3100 m were recorded, their flight skills seemed inadequate. Future management considerations include the initiation of a pre-release exercise regime, the establishment of an acclimatization enclosure removed from the breeding site, and a varied or reduced post-release feeding schedule. Fledglings should be relocated and housed at the release enclosure until they are four years old.
- Full Text:
Sorptive and microbial properties of low-cost adsorbents used in the extraction of ciprofloxacin and isoniazid from aqueous solution
- Authors: Dube, Cyril Simbarashe
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSC
- Identifier: http://hdl.handle.net/10962/59178 , vital:27450
- Description: This work describes how coal fly ash (FA), kaolinite, perlite, talc and vermiculite were used to remove ciprofloxacin and isoniazid from aqueous solutions. The adsorptive features of the adsorbents were evaluated for ciprofloxacin and isoniazid with regards to the effects of contact time, pH, solid/liquid ratio and antibiotic concentration. All adsorbents were sterilised by dry heat before use to avoid the proliferation of antimicrobial resistance by the bacteria present on the adsorbents during experiments. The regression correlation coefficients indicate that the linearised form of the Langmuir isotherm gives the best fit for the sorption of both antibiotics onto FA and talc, ciprofloxacin onto kaolinite, and isoniazid onto perlite and vermiculite with R2 values ranging from 0.908 - 0.999. The linearised form of the Freundlich isotherm best describes the sorption of ciprofloxacin onto vermiculite and isoniazid onto kaolinite with R2 values of 0.999 for both. The linearised form of the Temkin isotherm best describes the sorption of ciprofloxacin onto perlite with an R2 = 0.997. The values of the Freundlich exponent, 1/n, range from 0.221 - 0.998, indicating a favourable adsorption of ciprofloxacin and isoniazid onto the adsorbents. The heat of sorption, B, calculated from the Temkin plots has values ranging from 0.018 - 10.460 J/mol, indicating a physical adsorption process (physisorption). Adsorption equilibrium on all adsorbents was achieved after 30 min for both antibiotics and the kinetic data obtained conforms best to the pseudo-second order equation with R2 values ranging from 0.998 - 0.999. The removal of ciprofloxacin and isoniazid by all adsorbents except FA was strongly influenced by the pH suggesting that electrostatic interactions play a major role in the adsorption processes. All adsorbents except FA removed showed excellent adsorption of ciprofloxacin from aqueous solutions with all of them achieving removals ranging from 80 - 99%. The adsorbents were less efficient in removing isoniazid and kaolinite gave the highest removal of 55 %. Furthermore, the microbial quality of the adsorbents was investigated and the results revealed that kaolinite, talc, perlite and vermiculite were heavily contaminated with microorganisms. FA was sterile. The fungi isolated from the mineral adsorbents were in concentrations ranging from 2.13 x 106 to 1.25 x 107 CFU/g and were mostly moulds; Penicillium spp., Aspergillus niger, Aspergillus fumigatus, Aspergillus flavus, Cladosporium spp. and Rhizopus oryzae. One yeast was isolated and was identified as Candida albicans. The bacteria identified were in concentrations ranging from 4.96 x 106 - 1.19 x 109 CFU/g. E. coli, Enterobacter cloacae, Exiguobacterium spp., Pseudomonas aeruginosa, Bacillus spp. and Serratia liquefaciens. The leachability index (LI) values obtained for adsorbents indicated that it is highly unlikely that microorganisms could be leached out of the adsorbents by rain. Heat inactivation of the microorganisms at a 105 °C was totally unsuccessful. However, it was established that a dry heat dose of 160 °C for at least 15 min was sufficient to eradicate all microorganisms present in the adsorbents. The D-values for coliform bacteria from all samples were very similar ranging from 1.7-2.2 min indicating homogeneity in heat resistance by the microorganisms. The Pseudomonas aureginosa isolated had a D-value of 2.2 min. The fungi isolated from the samples had D-values ranging from 2.1-3.2 min.
- Full Text:
- Authors: Dube, Cyril Simbarashe
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSC
- Identifier: http://hdl.handle.net/10962/59178 , vital:27450
- Description: This work describes how coal fly ash (FA), kaolinite, perlite, talc and vermiculite were used to remove ciprofloxacin and isoniazid from aqueous solutions. The adsorptive features of the adsorbents were evaluated for ciprofloxacin and isoniazid with regards to the effects of contact time, pH, solid/liquid ratio and antibiotic concentration. All adsorbents were sterilised by dry heat before use to avoid the proliferation of antimicrobial resistance by the bacteria present on the adsorbents during experiments. The regression correlation coefficients indicate that the linearised form of the Langmuir isotherm gives the best fit for the sorption of both antibiotics onto FA and talc, ciprofloxacin onto kaolinite, and isoniazid onto perlite and vermiculite with R2 values ranging from 0.908 - 0.999. The linearised form of the Freundlich isotherm best describes the sorption of ciprofloxacin onto vermiculite and isoniazid onto kaolinite with R2 values of 0.999 for both. The linearised form of the Temkin isotherm best describes the sorption of ciprofloxacin onto perlite with an R2 = 0.997. The values of the Freundlich exponent, 1/n, range from 0.221 - 0.998, indicating a favourable adsorption of ciprofloxacin and isoniazid onto the adsorbents. The heat of sorption, B, calculated from the Temkin plots has values ranging from 0.018 - 10.460 J/mol, indicating a physical adsorption process (physisorption). Adsorption equilibrium on all adsorbents was achieved after 30 min for both antibiotics and the kinetic data obtained conforms best to the pseudo-second order equation with R2 values ranging from 0.998 - 0.999. The removal of ciprofloxacin and isoniazid by all adsorbents except FA was strongly influenced by the pH suggesting that electrostatic interactions play a major role in the adsorption processes. All adsorbents except FA removed showed excellent adsorption of ciprofloxacin from aqueous solutions with all of them achieving removals ranging from 80 - 99%. The adsorbents were less efficient in removing isoniazid and kaolinite gave the highest removal of 55 %. Furthermore, the microbial quality of the adsorbents was investigated and the results revealed that kaolinite, talc, perlite and vermiculite were heavily contaminated with microorganisms. FA was sterile. The fungi isolated from the mineral adsorbents were in concentrations ranging from 2.13 x 106 to 1.25 x 107 CFU/g and were mostly moulds; Penicillium spp., Aspergillus niger, Aspergillus fumigatus, Aspergillus flavus, Cladosporium spp. and Rhizopus oryzae. One yeast was isolated and was identified as Candida albicans. The bacteria identified were in concentrations ranging from 4.96 x 106 - 1.19 x 109 CFU/g. E. coli, Enterobacter cloacae, Exiguobacterium spp., Pseudomonas aeruginosa, Bacillus spp. and Serratia liquefaciens. The leachability index (LI) values obtained for adsorbents indicated that it is highly unlikely that microorganisms could be leached out of the adsorbents by rain. Heat inactivation of the microorganisms at a 105 °C was totally unsuccessful. However, it was established that a dry heat dose of 160 °C for at least 15 min was sufficient to eradicate all microorganisms present in the adsorbents. The D-values for coliform bacteria from all samples were very similar ranging from 1.7-2.2 min indicating homogeneity in heat resistance by the microorganisms. The Pseudomonas aureginosa isolated had a D-value of 2.2 min. The fungi isolated from the samples had D-values ranging from 2.1-3.2 min.
- Full Text:
Spectroscopic and electrochemical characterization of thio binuclear phthalocyanine complexes
- Authors: Makinde, Zainab Olusola
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/59287 , vital:27541
- Description: Expected release date-April 2019
- Full Text:
- Authors: Makinde, Zainab Olusola
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/59287 , vital:27541
- Description: Expected release date-April 2019
- Full Text:
Stochastic models in finance
- Authors: Mazengera, Hassan
- Date: 2017
- Subjects: Finance -- Mathematical models , C++ (Computer program language) , GARCH model , Lebesgue-Radon-Nikodym theorems , Radon measures , Stochastic models , Stochastic processes , Stochastic processes -- Computer programs , Martingales (Mathematics) , Pricing -- Mathematical models
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/162724 , vital:40976
- Description: Stochastic models for pricing financial securities are developed. First, we consider the Black Scholes model, which is a classic example of a complete market model and finally focus on Lévy driven models. Jumps may render the market incomplete and are induced in a model by inclusion of a Poisson process. Lévy driven models are more realistic in modelling of asset price dynamics than the Black Scholes model. Martingales are central in pricing, especially of derivatives and we give them the desired attention in the context of pricing. There are an increasing number of important pricing models where analytical solutions are not available hence computational methods come in handy, see Broadie and Glasserman (1997). It is also important to note that computational methods are also applicable to models with analytical solutions. We computationally value selected stochastic financial models using C++. Computational methods are also used to value or price complex financial instruments such as path dependent derivatives. This pricing procedure is applied in the computational valuation of a stochastic (revenue based) loan contract. Derivatives with simple pay of functions and models with analytical solutions are considered for illustrative purposes. The Black-Scholes P.D.E is complex to solve analytically and finite difference methods are widely used. Explicit finite difference scheme is considered in this thesis for computational valuation of derivatives that are modelled by the Black-Scholes P.D.E. Stochastic modelling of asset prices is important for the valuation of derivatives: Gaussian, exponential and gamma variates are simulated for the valuation purposes.
- Full Text:
- Authors: Mazengera, Hassan
- Date: 2017
- Subjects: Finance -- Mathematical models , C++ (Computer program language) , GARCH model , Lebesgue-Radon-Nikodym theorems , Radon measures , Stochastic models , Stochastic processes , Stochastic processes -- Computer programs , Martingales (Mathematics) , Pricing -- Mathematical models
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/162724 , vital:40976
- Description: Stochastic models for pricing financial securities are developed. First, we consider the Black Scholes model, which is a classic example of a complete market model and finally focus on Lévy driven models. Jumps may render the market incomplete and are induced in a model by inclusion of a Poisson process. Lévy driven models are more realistic in modelling of asset price dynamics than the Black Scholes model. Martingales are central in pricing, especially of derivatives and we give them the desired attention in the context of pricing. There are an increasing number of important pricing models where analytical solutions are not available hence computational methods come in handy, see Broadie and Glasserman (1997). It is also important to note that computational methods are also applicable to models with analytical solutions. We computationally value selected stochastic financial models using C++. Computational methods are also used to value or price complex financial instruments such as path dependent derivatives. This pricing procedure is applied in the computational valuation of a stochastic (revenue based) loan contract. Derivatives with simple pay of functions and models with analytical solutions are considered for illustrative purposes. The Black-Scholes P.D.E is complex to solve analytically and finite difference methods are widely used. Explicit finite difference scheme is considered in this thesis for computational valuation of derivatives that are modelled by the Black-Scholes P.D.E. Stochastic modelling of asset prices is important for the valuation of derivatives: Gaussian, exponential and gamma variates are simulated for the valuation purposes.
- Full Text:
Synthesis and evaluation of arylpyrrole-chalcone hybrids as antiplasmodial and antitrypanosomal agents
- Authors: Zulu, Ayanda Ignatia
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/65268 , vital:28716
- Description: Expected release date-May 2019
- Full Text:
- Authors: Zulu, Ayanda Ignatia
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/65268 , vital:28716
- Description: Expected release date-May 2019
- Full Text:
Taste masking of clarithromycin with ion exchange resins
- Authors: Ntemi, Pascal Vitalis
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/65178 , vital:28701
- Description: Expected release date-May 2019
- Full Text:
- Authors: Ntemi, Pascal Vitalis
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/65178 , vital:28701
- Description: Expected release date-May 2019
- Full Text:
The development of biodegradable aerogel scaffolds for the generation of vascularised 3D adipose tissue models
- Authors: Makhene, Lebohang
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/59245 , vital:27492
- Description: Expected release date-April 2019
- Full Text:
- Authors: Makhene, Lebohang
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/59245 , vital:27492
- Description: Expected release date-April 2019
- Full Text:
The development, manufacture and characterisation of niosomes intended to deliver nevirapine to the brain
- Authors: Witika, Bwalya Angel
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/65257 , vital:28715
- Description: Expected release date-May 2019
- Full Text:
- Authors: Witika, Bwalya Angel
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/65257 , vital:28715
- Description: Expected release date-May 2019
- Full Text:
The ecological impacts of pollution on a river ecosystem: a community index and stable isotope approach
- Authors: Gininda, Simphiwe Linah
- Date: 2017
- Subjects: Water -- Pollution -- Bloukrans River , Water quality -- South Africa -- Makhanda , Stream ecology -- South Africa -- Makhanda , South African Scoring System , Sewage disposal in rivers, lakes, etc. -- South Africa -- Makhanda , Agricultural ecology -- South Africa -- Makhanda , Agricultural pollution -- South Africa -- Makhanda
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/7993 , vital:21331
- Description: For decades, urbanized rivers have been modified to meet the needs of constantly expanding human populations in many countries around the world. The Bloukrans River in Grahamstown is one of the polluted and structurally modified urban rivers in South Africa, and there is no published information regarding its water quality and ecological status. Water quality is threatened by human activities including the disposal of treated and raw sewage, livestock farming, and agriculture. This study was conducted to determine the ecological status of the river by assessing its biological, chemical, and physical components in relation to man-mediated activities. Biological responses of macroinvertebrates were used to assess changes in water quality through space and time based on the South African Scoring System version 5 and the Average Score per Taxon water quality indices. The results showed poor water quality due to high nitrate and ammonium concentrations derived from sewage, and channel modifications by agricultural activities and dumping of solid waste. Channel width, water depth, dissolved oxygen, nitrate, and ammonium concentrations were the main drivers of macroinvertebrate distribution patterns and had the most influence on the variability in macroinvertebrates taxa richness, diversity and abundance. Diatoms were also used to assess water quality, specifically to indicate the trophic status of the river based on changes in the Trophic Diatom Index. The results suggested that the Bloukrans River was eutrophic during the course of this study. However, the trophic status varied with freshwater input, resulting in mesotrophic conditions during flooding and eutrophication in dry seasons. Changes in pH, phosphate concentration, water velocity (current speed), and temperature influenced the distribution of diatoms in the Bloukrans River. However, only pH was important at the community level and significantly influenced diatom abundances. Stable nitrogen isotope ratios (S15N) of autotrophs and primary and secondary consumers revealed noticeable differences between tissues of organisms exposed to treated sewage and those without any exposure. The S15N values in biota occurring above the sewage treatment discharge point were low, and those collected below the sewage point were higher. Although fertilizer derived nitrogen is generally depleted in 15N, agriculture-derived nitrogen could not be excluded as a possible source since animals at the sample site that was most affected by agricultural activities had the highest S15N values. This study provided valuable information on the ecological status of the Bloukrans River and identified the major activities associated with reduced biodiversity and water quality.
- Full Text:
- Authors: Gininda, Simphiwe Linah
- Date: 2017
- Subjects: Water -- Pollution -- Bloukrans River , Water quality -- South Africa -- Makhanda , Stream ecology -- South Africa -- Makhanda , South African Scoring System , Sewage disposal in rivers, lakes, etc. -- South Africa -- Makhanda , Agricultural ecology -- South Africa -- Makhanda , Agricultural pollution -- South Africa -- Makhanda
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/7993 , vital:21331
- Description: For decades, urbanized rivers have been modified to meet the needs of constantly expanding human populations in many countries around the world. The Bloukrans River in Grahamstown is one of the polluted and structurally modified urban rivers in South Africa, and there is no published information regarding its water quality and ecological status. Water quality is threatened by human activities including the disposal of treated and raw sewage, livestock farming, and agriculture. This study was conducted to determine the ecological status of the river by assessing its biological, chemical, and physical components in relation to man-mediated activities. Biological responses of macroinvertebrates were used to assess changes in water quality through space and time based on the South African Scoring System version 5 and the Average Score per Taxon water quality indices. The results showed poor water quality due to high nitrate and ammonium concentrations derived from sewage, and channel modifications by agricultural activities and dumping of solid waste. Channel width, water depth, dissolved oxygen, nitrate, and ammonium concentrations were the main drivers of macroinvertebrate distribution patterns and had the most influence on the variability in macroinvertebrates taxa richness, diversity and abundance. Diatoms were also used to assess water quality, specifically to indicate the trophic status of the river based on changes in the Trophic Diatom Index. The results suggested that the Bloukrans River was eutrophic during the course of this study. However, the trophic status varied with freshwater input, resulting in mesotrophic conditions during flooding and eutrophication in dry seasons. Changes in pH, phosphate concentration, water velocity (current speed), and temperature influenced the distribution of diatoms in the Bloukrans River. However, only pH was important at the community level and significantly influenced diatom abundances. Stable nitrogen isotope ratios (S15N) of autotrophs and primary and secondary consumers revealed noticeable differences between tissues of organisms exposed to treated sewage and those without any exposure. The S15N values in biota occurring above the sewage treatment discharge point were low, and those collected below the sewage point were higher. Although fertilizer derived nitrogen is generally depleted in 15N, agriculture-derived nitrogen could not be excluded as a possible source since animals at the sample site that was most affected by agricultural activities had the highest S15N values. This study provided valuable information on the ecological status of the Bloukrans River and identified the major activities associated with reduced biodiversity and water quality.
- Full Text: