Remote sensing as a monitoring solution for water hyacinth (Pontederia crassipes) in the context of the biological control programme at Hartbeespoort Dam
- Authors: Kinsler, David Louis
- Date: 2023-10-13
- Subjects: Remote sensing , Water hyacinth South Africa Hartbeespoort , Aquatic weeds Biological control South Africa Hartbeespoort , Megamelus scutellaris , Eutrophication
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424599 , vital:72167
- Description: Water hyacinth (Pontederia crassipes (C.Mart.) Solms (Pontederiaceae)) is a significant aquatic weed both globally and in South Africa. Despite notable success with biological control of other invasive macrophytes, the plant remains as a problematic weed in many aquatic systems in South Africa, particularly due to the eutrophic status of many of its water systems, as well as the plant’s tolerance to cooler climatic conditions than most of its existing biological control agents. Hartbeespoort Dam, located about 30 kilometres west of Pretoria, South Africa, has been infamously infested with water hyacinth for decades, which impacts the important socioeconomic utility of the dam and functioning of natural ecological processes in the system. The dam has a long history of efforts to control water hyacinth, which include widespread herbicidal spray, mechanical removal and classical biological control programmes since the early 1990s - mostly with limited or short-lived success. However, after the introduction of a new, cold-tolerant biological control agent, Megamelus scutellaris Berg (Hemiptera: Delphacidae) in 2018 with an inundative release strategy, the water hyacinth dropped significantly from a maximum cover of about 45 percent (819 hectares) down to less than two percent (40 hectares) over a three-month period (November 2019 – January 2020). This was significant, as it marked the first successful biological control of water hyacinth in a eutrophic, temperate system in South Africa. However, due to the scale of Hartbeespoort Dam (1820 hectares) and the high spatiotemporal variation of the floating mats across time and space, quantifying and monitoring these rapid changes has proved difficult. In response to this problem, this thesis proposed a remote sensing solution to address the need for accurate, timely and readily accessible monitoring data of the water hyacinth population on the dam. Leveraging the temporally frequent (< 5 days revisit time) Sentinel-2 multispectral satellite data, as well as the powerful cloud-computing resources of Google Earth Engine, this thesis developed and deployed a relatively simple and robust index-based decision tree classification method to demonstrate the value of these technologies as an effective monitoring and analysis tool for monitoring large macrophyte infestations. To this end, several challenges had to be overcome in order to produce easily accessible data that was accurate and reliable. For example, due to the size of the Sentinel-2 Level-1C image dataset from August 2015 to March 2021 (n = 654), an automated process of filtering out clouded images was required. Additionally, the co-presence of algal and cyanobacterial blooms necessitated the development of a novel index, coined the Algae Resistant Macrophyte Index (ARMI), to deal with the challenges of accurate macrophyte detection. The high spatiotemporal variability of the floating mats meant that a typical, location-based confusion matrix as a means of assessing the accuracy of the decision tree classifier required a different approach which compared the total classified areas with higher resolution images. This thesis aims to demonstrate the utility of remote sensing tools to provide effective monitoring information to managers, researchers and other stakeholders. There is scope to expand to more areas in South Africa and beyond and may prove an invaluable tool to augment and support on-going and future macrophyte monitoring programmes. , Thesis (MSc) -- Faculty of Science, Geography, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Kinsler, David Louis
- Date: 2023-10-13
- Subjects: Remote sensing , Water hyacinth South Africa Hartbeespoort , Aquatic weeds Biological control South Africa Hartbeespoort , Megamelus scutellaris , Eutrophication
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424599 , vital:72167
- Description: Water hyacinth (Pontederia crassipes (C.Mart.) Solms (Pontederiaceae)) is a significant aquatic weed both globally and in South Africa. Despite notable success with biological control of other invasive macrophytes, the plant remains as a problematic weed in many aquatic systems in South Africa, particularly due to the eutrophic status of many of its water systems, as well as the plant’s tolerance to cooler climatic conditions than most of its existing biological control agents. Hartbeespoort Dam, located about 30 kilometres west of Pretoria, South Africa, has been infamously infested with water hyacinth for decades, which impacts the important socioeconomic utility of the dam and functioning of natural ecological processes in the system. The dam has a long history of efforts to control water hyacinth, which include widespread herbicidal spray, mechanical removal and classical biological control programmes since the early 1990s - mostly with limited or short-lived success. However, after the introduction of a new, cold-tolerant biological control agent, Megamelus scutellaris Berg (Hemiptera: Delphacidae) in 2018 with an inundative release strategy, the water hyacinth dropped significantly from a maximum cover of about 45 percent (819 hectares) down to less than two percent (40 hectares) over a three-month period (November 2019 – January 2020). This was significant, as it marked the first successful biological control of water hyacinth in a eutrophic, temperate system in South Africa. However, due to the scale of Hartbeespoort Dam (1820 hectares) and the high spatiotemporal variation of the floating mats across time and space, quantifying and monitoring these rapid changes has proved difficult. In response to this problem, this thesis proposed a remote sensing solution to address the need for accurate, timely and readily accessible monitoring data of the water hyacinth population on the dam. Leveraging the temporally frequent (< 5 days revisit time) Sentinel-2 multispectral satellite data, as well as the powerful cloud-computing resources of Google Earth Engine, this thesis developed and deployed a relatively simple and robust index-based decision tree classification method to demonstrate the value of these technologies as an effective monitoring and analysis tool for monitoring large macrophyte infestations. To this end, several challenges had to be overcome in order to produce easily accessible data that was accurate and reliable. For example, due to the size of the Sentinel-2 Level-1C image dataset from August 2015 to March 2021 (n = 654), an automated process of filtering out clouded images was required. Additionally, the co-presence of algal and cyanobacterial blooms necessitated the development of a novel index, coined the Algae Resistant Macrophyte Index (ARMI), to deal with the challenges of accurate macrophyte detection. The high spatiotemporal variability of the floating mats meant that a typical, location-based confusion matrix as a means of assessing the accuracy of the decision tree classifier required a different approach which compared the total classified areas with higher resolution images. This thesis aims to demonstrate the utility of remote sensing tools to provide effective monitoring information to managers, researchers and other stakeholders. There is scope to expand to more areas in South Africa and beyond and may prove an invaluable tool to augment and support on-going and future macrophyte monitoring programmes. , Thesis (MSc) -- Faculty of Science, Geography, 2023
- Full Text:
- Date Issued: 2023-10-13
The implementation of new public management principles towards effective service delivery in the Eastern Cape government
- Authors: Gwavu, Luzuko
- Date: 2022-03
- Subjects: Performance--Management. , Public administration. , Performance--Evaluation.
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21903 , vital:51841
- Description: New Public Management (NPM) is a new paradigm of public administration which highlights the failures and inadequacies of the public sector performance over time. NPM was developed in order to enhance performance and service delivery within the public sector through adopting principles of the public sector. The nature and process of the activities within the public sector and the traditional public administration have been seen as problematic. As such, the birth of NPM is grounded in the need to offer more efficient mechanisms for service delivery. This study aimed at assessing the implementation of NPM principles towards effective service delivery within the Eastern Cape government. The study was underpinned by the New Public Management Approach. A qualitative desktop review was adopted to find answers to research questions of the study. The data was evaluated qualitatively through thematic analysis. The study findings reveal that the Eastern Cape government is making strides to effectively implement NPM principles towards improving service delivery. The implemented principles are privatisation, managerialism, performance management, decentralisation and customer oriented. The effectiveness of strategies aimed at enhancing effective implementation of NPM principles for improved service delivery was also assessed. The findings show that the strategies are effective although there are some inherent issues that derail effective implementation. Poor reporting, corruption, poor management, shortage of trained managers and staff shortages were identified as challenges affecting effective implementation of NPM principles. The study recommends the need for effective implementation of anti-corruption policies as well as facilitating training and skills development. , Thesis (MPA) -- University of Fort Hare, 2022
- Full Text:
- Date Issued: 2022-03
- Authors: Gwavu, Luzuko
- Date: 2022-03
- Subjects: Performance--Management. , Public administration. , Performance--Evaluation.
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21903 , vital:51841
- Description: New Public Management (NPM) is a new paradigm of public administration which highlights the failures and inadequacies of the public sector performance over time. NPM was developed in order to enhance performance and service delivery within the public sector through adopting principles of the public sector. The nature and process of the activities within the public sector and the traditional public administration have been seen as problematic. As such, the birth of NPM is grounded in the need to offer more efficient mechanisms for service delivery. This study aimed at assessing the implementation of NPM principles towards effective service delivery within the Eastern Cape government. The study was underpinned by the New Public Management Approach. A qualitative desktop review was adopted to find answers to research questions of the study. The data was evaluated qualitatively through thematic analysis. The study findings reveal that the Eastern Cape government is making strides to effectively implement NPM principles towards improving service delivery. The implemented principles are privatisation, managerialism, performance management, decentralisation and customer oriented. The effectiveness of strategies aimed at enhancing effective implementation of NPM principles for improved service delivery was also assessed. The findings show that the strategies are effective although there are some inherent issues that derail effective implementation. Poor reporting, corruption, poor management, shortage of trained managers and staff shortages were identified as challenges affecting effective implementation of NPM principles. The study recommends the need for effective implementation of anti-corruption policies as well as facilitating training and skills development. , Thesis (MPA) -- University of Fort Hare, 2022
- Full Text:
- Date Issued: 2022-03
An analysis of talent management practices of recently hired employees from the perspective of the psychological contract
- Authors: Bischoff, Olivia Edjegayhu
- Date: 2021-10-29
- Subjects: Gifted persons , Contracts Psychological aspects , Personnel management Psychological aspects , Breach of contract , Psychology, Industrial , Organizational behavior , Industrial relations , Employees Attitudes , Employee retention
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/191865 , vital:45173
- Description: This research took the form of an explanatory case study focused within a single organisation to evaluate talent management practices of recently hired employees from the perspective of the psychological contract. The theory underpinning this research is Resource-Based Theory (RBT) in the context of Talent Management. The research aims were: 1) to analyse how talent management practices have affected the psychological contract, 2) to analyse how employees have responded and intend to respond if there has been a breach in the contract and 3) to analyse how employees have responded or intend to respond where psychological contract expectations have been met. The key concepts identified include talent management and the psychological contract. The literature therefore expanded on talent management highlighting the importance of recruiting, attracting and retaining talent, especially in a global context where experience and skills are a source of competitive advantage. Following this, the concept of the psychological contract was used as a lens through which to analyse the experience of individuals, specifically focusing on new employees joining the organisation, to assess their socialisation and onboarding experience. The literature further explored the importance of focusing on new employees, as this is deemed by the literature as a critical time of transition in the shaping of the psychological contract. In further reviewing the literature regarding early onboarding, further review of the literature identified important components, including (1) socialisation and onboarding, (2) performance management and probation, (3) employee development and (4) work conditions. From reviewing the literature four propositions were deduced as follows: • Proposition 1: All integrative processes in early onboarding influence the initial psychological contract of the employee. Proposition 1 was further divided into three sub propositions as follows: Sub Proposition 1a) HR plays a key role in early onboarding, influencing the initial psychological contract; Sub Proposition 1b) Supervisor support plays a key role in early onboarding, influencing the initial psychological contract; and IV Sub Proposition 1c) The work team plays a key role in early onboarding, influencing the initial psychological contract. • Proposition 2 stated: Performance discussions influence the psychological contract. • Proposition 3: Employee development opportunities are a source of motivation in the fulfilment of the psychological contract. • Proposition 4: Employment conditions influence the fulfilment of the psychological contract. The research followed a qualitative approach, using deductive analysis to analyse the data collected from semi-structured interviews. The findings and discussion show that the propositions confirmed the literature and were relevant to the case study at hand. Where there was varying degree of experience regarding the effect of the influence or impact on the psychological contract this was noted and expanded on accordingly. The study also recognised the additional context that presented itself within the findings, namely the context of the COVID-19 pandemic. The research concludes in acknowledging the delimitations and limitations of the study while making suggestions for areas of future studies. To conclude, this research shows that the transition of a new employee in their early stages within the organisation is an opportunity to support in positively influencing and maintaining the psychological contract to support employee satisfaction and motivation. If organisations can also appreciate that the psychological contract is dynamic and can change over time based on changing circumstances or needs, then this can be proactively monitored to support long-term retention of talent. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Bischoff, Olivia Edjegayhu
- Date: 2021-10-29
- Subjects: Gifted persons , Contracts Psychological aspects , Personnel management Psychological aspects , Breach of contract , Psychology, Industrial , Organizational behavior , Industrial relations , Employees Attitudes , Employee retention
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/191865 , vital:45173
- Description: This research took the form of an explanatory case study focused within a single organisation to evaluate talent management practices of recently hired employees from the perspective of the psychological contract. The theory underpinning this research is Resource-Based Theory (RBT) in the context of Talent Management. The research aims were: 1) to analyse how talent management practices have affected the psychological contract, 2) to analyse how employees have responded and intend to respond if there has been a breach in the contract and 3) to analyse how employees have responded or intend to respond where psychological contract expectations have been met. The key concepts identified include talent management and the psychological contract. The literature therefore expanded on talent management highlighting the importance of recruiting, attracting and retaining talent, especially in a global context where experience and skills are a source of competitive advantage. Following this, the concept of the psychological contract was used as a lens through which to analyse the experience of individuals, specifically focusing on new employees joining the organisation, to assess their socialisation and onboarding experience. The literature further explored the importance of focusing on new employees, as this is deemed by the literature as a critical time of transition in the shaping of the psychological contract. In further reviewing the literature regarding early onboarding, further review of the literature identified important components, including (1) socialisation and onboarding, (2) performance management and probation, (3) employee development and (4) work conditions. From reviewing the literature four propositions were deduced as follows: • Proposition 1: All integrative processes in early onboarding influence the initial psychological contract of the employee. Proposition 1 was further divided into three sub propositions as follows: Sub Proposition 1a) HR plays a key role in early onboarding, influencing the initial psychological contract; Sub Proposition 1b) Supervisor support plays a key role in early onboarding, influencing the initial psychological contract; and IV Sub Proposition 1c) The work team plays a key role in early onboarding, influencing the initial psychological contract. • Proposition 2 stated: Performance discussions influence the psychological contract. • Proposition 3: Employee development opportunities are a source of motivation in the fulfilment of the psychological contract. • Proposition 4: Employment conditions influence the fulfilment of the psychological contract. The research followed a qualitative approach, using deductive analysis to analyse the data collected from semi-structured interviews. The findings and discussion show that the propositions confirmed the literature and were relevant to the case study at hand. Where there was varying degree of experience regarding the effect of the influence or impact on the psychological contract this was noted and expanded on accordingly. The study also recognised the additional context that presented itself within the findings, namely the context of the COVID-19 pandemic. The research concludes in acknowledging the delimitations and limitations of the study while making suggestions for areas of future studies. To conclude, this research shows that the transition of a new employee in their early stages within the organisation is an opportunity to support in positively influencing and maintaining the psychological contract to support employee satisfaction and motivation. If organisations can also appreciate that the psychological contract is dynamic and can change over time based on changing circumstances or needs, then this can be proactively monitored to support long-term retention of talent. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2021
- Full Text:
- Date Issued: 2021-10-29
Concerning Marya Schechtman’s narrative account
- Authors: Simuja, Clement
- Date: 2021-10-29
- Subjects: Schechtman, Marya, 1960- Criticism and interpretation , Narrative inquiry (Research method) , Identity (Psychology) , Identity (Philosophical concept) , Self , Individuality
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190748 , vital:45024
- Description: The persistence of personal identity stands at the heart of many human practices, such as paying individuals for their work or holding people responsible for their actions. As such, it seems important that theories of personal identity are able to account for the practical implications of continuity of personal identity. Mindful of the practical importance of personal identity, Marya Schechtman (1994) argues that her narrative view only accounts for the four features that persons must possess. Any account of personal identity is supposed to make persons capable of possessing these features. She then posits her narrative self-constitution view as an account of personal identity she feels is capable of explaining the link between personal identity and certain features of persons. In this thesis project, I present how the narrative views, as described by Schechtman and others, are interpretive enterprises and that this leads them to a potentially devastating conclusion. The narratives must be constructed from something, and I argue that it is memory. But empirical facts about memory do not allow for it to persist in a quantitative way, but rather in a qualitative way, much like persons. Upon making this argument, I further argue that if mainstream psychological views is correct, this reduces the persistence of memory to resemblance relations. And memory is the building blocks of narrative. If this is the case, then narrative is also reduced to resemblance relations. Narrative, therefore, does not persist through time in a non-qualitative way, and one is better off accepting a psychological theory by virtue of parsimony. Ultimately, I argue that Schechtman and narrative theorists may save narrative views by adopting what I call as a ‘causal narrative view’. A causal narrative view will encapsulate all of the relevant features of the typical narrative view, including the emphasis on construction, but will also add the addendum that narrative states must be placed in a causal relation to each other. , Thesis (MA) -- Faculty of Humanities, Philosophy, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Simuja, Clement
- Date: 2021-10-29
- Subjects: Schechtman, Marya, 1960- Criticism and interpretation , Narrative inquiry (Research method) , Identity (Psychology) , Identity (Philosophical concept) , Self , Individuality
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190748 , vital:45024
- Description: The persistence of personal identity stands at the heart of many human practices, such as paying individuals for their work or holding people responsible for their actions. As such, it seems important that theories of personal identity are able to account for the practical implications of continuity of personal identity. Mindful of the practical importance of personal identity, Marya Schechtman (1994) argues that her narrative view only accounts for the four features that persons must possess. Any account of personal identity is supposed to make persons capable of possessing these features. She then posits her narrative self-constitution view as an account of personal identity she feels is capable of explaining the link between personal identity and certain features of persons. In this thesis project, I present how the narrative views, as described by Schechtman and others, are interpretive enterprises and that this leads them to a potentially devastating conclusion. The narratives must be constructed from something, and I argue that it is memory. But empirical facts about memory do not allow for it to persist in a quantitative way, but rather in a qualitative way, much like persons. Upon making this argument, I further argue that if mainstream psychological views is correct, this reduces the persistence of memory to resemblance relations. And memory is the building blocks of narrative. If this is the case, then narrative is also reduced to resemblance relations. Narrative, therefore, does not persist through time in a non-qualitative way, and one is better off accepting a psychological theory by virtue of parsimony. Ultimately, I argue that Schechtman and narrative theorists may save narrative views by adopting what I call as a ‘causal narrative view’. A causal narrative view will encapsulate all of the relevant features of the typical narrative view, including the emphasis on construction, but will also add the addendum that narrative states must be placed in a causal relation to each other. , Thesis (MA) -- Faculty of Humanities, Philosophy, 2021
- Full Text:
- Date Issued: 2021-10-29
Framing realities : a critical analysis of perspectival distortion in the film Alice by Czech Surrealist Jan Švankmajer
- Authors: Soutter, Simone
- Date: 2021-04
- Subjects: Švankmajer, Jan, 1934- -- Criticism and interpretation , Depression, Mental -- Exhibitions , Perception , Frames (Sociology) , Surrealism -- Influence , Cubism -- Influence , Surrealism in motion pictures , Depression, Mental in art
- Language: English
- Type: thesis , text , Masters , MFA
- Identifier: http://hdl.handle.net/10962/178365 , vital:42933
- Description: My MFA exhibition Through the looking glass; altered states of perception, explores my experience of mental distress: Major Depressive Disorder (MDD), through the medium of painting and multimedia collage. Situated in the Main Fine Art building on Rhodes University campus, this practical submission takes the form of a collection of oil paintings accompanied by an immersive wall of collaged experimentations, depicting the perspectival shifts I have experienced in coping with mental distress. The paintings explore concepts of framing and perspective, both literally and metaphorically in unpacking how our perceptions are manipulated by the way in which situations and concepts are framed. I use strategies and techniques drawn from the Surrealist and Cubist movements in order to depict my distorted experience of time and space, but also to tap into my own unconscious. In this mini-thesis: Framing realities; A critical analysis of perspectival distortion in the film Alice by Czech Surrealist Jan Švankmajer, I explore the strategies and concepts developed during the Surrealist and Cubist movements in relation to strategies used by Švankmajer in his disturbing interpretation of Alice’s Adventures into Wonderland. Here, he visually explores the psyche of an imaginative child. His unique interpretation is expressed through the combination of live-action film and stop-motion animation. I position my work in relation to themes proposed by Maurice Merleau-Ponty, Ernst Jentch, Sigmund Freud and Julia Kristeva. In the first Chapter: Framing and Perspectival shifts, I unpack framing and perspectival shifts exhibited in the Cubist (a physical shift), Dadaist (a social shift), and Surrealist (an unconscious shift) movements. In Chapter Two: A critical analysis of Alice by Jan Švankmajer, I engage in an analysis of themes (examined in the above art movements) relative to the film Alice. These are found objects and assemblages, ambiguity, distortion of scale, the Unconscious, the uncanny and multi-sensory modalities. Chapter Three: Through the Looking Glass; Altered states of perception, I discuss how the themes discussed in Chapter Two apply to my own body of work and how these themes are addressed with regards to my lived experience of mental disorder and distress. , Thesis (MFA) -- Faculty of Humanities, Fine Arts, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Soutter, Simone
- Date: 2021-04
- Subjects: Švankmajer, Jan, 1934- -- Criticism and interpretation , Depression, Mental -- Exhibitions , Perception , Frames (Sociology) , Surrealism -- Influence , Cubism -- Influence , Surrealism in motion pictures , Depression, Mental in art
- Language: English
- Type: thesis , text , Masters , MFA
- Identifier: http://hdl.handle.net/10962/178365 , vital:42933
- Description: My MFA exhibition Through the looking glass; altered states of perception, explores my experience of mental distress: Major Depressive Disorder (MDD), through the medium of painting and multimedia collage. Situated in the Main Fine Art building on Rhodes University campus, this practical submission takes the form of a collection of oil paintings accompanied by an immersive wall of collaged experimentations, depicting the perspectival shifts I have experienced in coping with mental distress. The paintings explore concepts of framing and perspective, both literally and metaphorically in unpacking how our perceptions are manipulated by the way in which situations and concepts are framed. I use strategies and techniques drawn from the Surrealist and Cubist movements in order to depict my distorted experience of time and space, but also to tap into my own unconscious. In this mini-thesis: Framing realities; A critical analysis of perspectival distortion in the film Alice by Czech Surrealist Jan Švankmajer, I explore the strategies and concepts developed during the Surrealist and Cubist movements in relation to strategies used by Švankmajer in his disturbing interpretation of Alice’s Adventures into Wonderland. Here, he visually explores the psyche of an imaginative child. His unique interpretation is expressed through the combination of live-action film and stop-motion animation. I position my work in relation to themes proposed by Maurice Merleau-Ponty, Ernst Jentch, Sigmund Freud and Julia Kristeva. In the first Chapter: Framing and Perspectival shifts, I unpack framing and perspectival shifts exhibited in the Cubist (a physical shift), Dadaist (a social shift), and Surrealist (an unconscious shift) movements. In Chapter Two: A critical analysis of Alice by Jan Švankmajer, I engage in an analysis of themes (examined in the above art movements) relative to the film Alice. These are found objects and assemblages, ambiguity, distortion of scale, the Unconscious, the uncanny and multi-sensory modalities. Chapter Three: Through the Looking Glass; Altered states of perception, I discuss how the themes discussed in Chapter Two apply to my own body of work and how these themes are addressed with regards to my lived experience of mental disorder and distress. , Thesis (MFA) -- Faculty of Humanities, Fine Arts, 2021
- Full Text:
- Date Issued: 2021-04
Analysis of the regulation of HSP90α expression upon differentiation of C2C12 cells
- Authors: Holm, Nathan Christopher
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/163318 , vital:41028
- Description: Thesis (MSc)--Rhodes University, Faculty of Science, Biochemistry and Microbiology, 2020.
- Full Text:
- Date Issued: 2020
- Authors: Holm, Nathan Christopher
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/163318 , vital:41028
- Description: Thesis (MSc)--Rhodes University, Faculty of Science, Biochemistry and Microbiology, 2020.
- Full Text:
- Date Issued: 2020
Degradation of Paracetamol and other constituents in Perfalgan®: subtitle if needed. If no subtitle follow instructions in manual
- Authors: Curran,Catherine
- Date: 2014
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/11260/3165 , vital:43181
- Description: Abstract text. 5.1 Background Paracetamol (acetaminophen) is useful for the treatment of mild to moderate pain as well as being opiate–sparing. In recent years the problem of poor solubility of paracetamol in water has been overcome and an intravenous formulation of paracetamol developed. In South Africa this is marketed by Bristol-Myers Squibb as Perfalgan®. Each 500 mg or 1g ampoule of Perfalgan® is recommended for single use only and is to be discarded once opened (Medicines.org, n.d.). This is most likely due to concerns about degradation of paracetamol or other ingredients in the solution once exposed to air and sterility issues. However in South Africa where this drug is expensive, some centers use one ampoule for multiple cases over the course of 12-24 hours. No obvious clinical adverse effects have been reported. 5.2 Objective of study The aim of this study was to examine the practice of using a single vial of Perfalgan® in divided doses over the course of a day for different patients by way of assessing the stability of Perfalgan® on exposure to air. The study has three components, namely: 1. In vitro assessment of paracetamol levels on exposure to air and stressors over time. 2. In vitro assessment of levels of the excipients, namely mannitol and cysteine on exposure to air and stressors over time. 3. Assessment of the lipid permeability of paracetamol in Perfalgan® on exposure to air and stressors over time. C Curran 2014 Degradation of paracetamol and other constituents in Perfalgan® 8 5.3 Methodology High performance liquid chromatography (HPCL-UV) was used to determine the concentration of paracetamol and the presence of degradation products in samples taken at set time periods following exposure of Perfalgan® to air and stressors. Initial work was done using pure paracetamol to determine optimal measurement conditions prior to analysing Perfalgan®. The concentrations of the additives and their degradation products were measured using nuclear magnetic resonance (1 H NMR). Appreciable changes in these could indicate a safety hazard or decreased bioavailability. Finally ultraviolet spectroscopy was performed to assess samples at a wider spectrum of wavelengths, instead of the single wavelength used in HPLC. This was used to assess for degradation products which absorb at different wavelengths and therefore may be missed if HPLC was used alone. Ultraviolet spectroscopy was also used to test bioavailability of the drug via the octanol:water partition coefficient under stressed and unstressed conditions. 5.4 Results The paracetamol in Perfalgan® did not degrade on exposure to air over 24 hours. Neither did it degrade on exposure to acid, alkali, oxidative or heat stress. The HPLC retention time was constantly between 3.17-3.29 minutes. 1 H NMR revealed no change in the formulation of Perfalgan® except for the conversion of the oxygen scavenger cysteine to cystine. The octanol:water partition coefficient likewise stayed constant and was in agreement with the value of 0.46-0.49 quoted in the literature (International Programme on Chemical Safety, 2008; McNeil Consumer Healthcare, 2010). 5.5 Conclusion The paracetamol in Perfalgan® did not degrade on exposure to air and other stressors over 24 hours. The formulation as Perfalgan® was likewise found to be stable. The drug retained its lipid permeability over this period. , Thesis (MMED) -- Faculty of Health Sciences, 2014
- Full Text:
- Date Issued: 2014
- Authors: Curran,Catherine
- Date: 2014
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/11260/3165 , vital:43181
- Description: Abstract text. 5.1 Background Paracetamol (acetaminophen) is useful for the treatment of mild to moderate pain as well as being opiate–sparing. In recent years the problem of poor solubility of paracetamol in water has been overcome and an intravenous formulation of paracetamol developed. In South Africa this is marketed by Bristol-Myers Squibb as Perfalgan®. Each 500 mg or 1g ampoule of Perfalgan® is recommended for single use only and is to be discarded once opened (Medicines.org, n.d.). This is most likely due to concerns about degradation of paracetamol or other ingredients in the solution once exposed to air and sterility issues. However in South Africa where this drug is expensive, some centers use one ampoule for multiple cases over the course of 12-24 hours. No obvious clinical adverse effects have been reported. 5.2 Objective of study The aim of this study was to examine the practice of using a single vial of Perfalgan® in divided doses over the course of a day for different patients by way of assessing the stability of Perfalgan® on exposure to air. The study has three components, namely: 1. In vitro assessment of paracetamol levels on exposure to air and stressors over time. 2. In vitro assessment of levels of the excipients, namely mannitol and cysteine on exposure to air and stressors over time. 3. Assessment of the lipid permeability of paracetamol in Perfalgan® on exposure to air and stressors over time. C Curran 2014 Degradation of paracetamol and other constituents in Perfalgan® 8 5.3 Methodology High performance liquid chromatography (HPCL-UV) was used to determine the concentration of paracetamol and the presence of degradation products in samples taken at set time periods following exposure of Perfalgan® to air and stressors. Initial work was done using pure paracetamol to determine optimal measurement conditions prior to analysing Perfalgan®. The concentrations of the additives and their degradation products were measured using nuclear magnetic resonance (1 H NMR). Appreciable changes in these could indicate a safety hazard or decreased bioavailability. Finally ultraviolet spectroscopy was performed to assess samples at a wider spectrum of wavelengths, instead of the single wavelength used in HPLC. This was used to assess for degradation products which absorb at different wavelengths and therefore may be missed if HPLC was used alone. Ultraviolet spectroscopy was also used to test bioavailability of the drug via the octanol:water partition coefficient under stressed and unstressed conditions. 5.4 Results The paracetamol in Perfalgan® did not degrade on exposure to air over 24 hours. Neither did it degrade on exposure to acid, alkali, oxidative or heat stress. The HPLC retention time was constantly between 3.17-3.29 minutes. 1 H NMR revealed no change in the formulation of Perfalgan® except for the conversion of the oxygen scavenger cysteine to cystine. The octanol:water partition coefficient likewise stayed constant and was in agreement with the value of 0.46-0.49 quoted in the literature (International Programme on Chemical Safety, 2008; McNeil Consumer Healthcare, 2010). 5.5 Conclusion The paracetamol in Perfalgan® did not degrade on exposure to air and other stressors over 24 hours. The formulation as Perfalgan® was likewise found to be stable. The drug retained its lipid permeability over this period. , Thesis (MMED) -- Faculty of Health Sciences, 2014
- Full Text:
- Date Issued: 2014
Factors which Influence English Language Pass Rate at Matric Level in the Engcobo District of The Eastern Cape of South Africa
- Songwaxa, Nokuthula Patience
- Authors: Songwaxa, Nokuthula Patience
- Date: 2013
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/11260/3517 , vital:43622
- Description: This study investigates the management of English teaching to improve matriculation pass-rate in selected schools in the Engcobo District of the Eastern Cape of South Africa. The study has been circuits of the Engcobo district. Questionnaires were administered over a group of matriculants, English second language teachers and 8 school principals with a variety of questions and interviews on the causes of this failure problem. Based on the study it has been reared through collect data that some teachers have not been workshopped in the current curriculum (NCS) and this somehow affects the learners. Learners from rural areas have a problem in understanding English language. Lack of educational facilities like libraries also have a negative impact in learner’s progress. Learners who came from Junior Secondary Schools to High schools are not ready and this gives High School teachers a big task to mould them to be ready for matric. It is recommended that parental involvement is vital in their children’s education so as to see their progress and to develop the teacher-parent locomotives learners need to be engaged in Educational activities like debates, public speaking, conducting so as to improve their communication skills. Educators should give more writing and reading exercises to learners so as to minimize the number of learners who are unable to write in Matric. , Thesis (MMED) -- Faculty of Educational Sciences, 2013
- Full Text:
- Date Issued: 2013
- Authors: Songwaxa, Nokuthula Patience
- Date: 2013
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/11260/3517 , vital:43622
- Description: This study investigates the management of English teaching to improve matriculation pass-rate in selected schools in the Engcobo District of the Eastern Cape of South Africa. The study has been circuits of the Engcobo district. Questionnaires were administered over a group of matriculants, English second language teachers and 8 school principals with a variety of questions and interviews on the causes of this failure problem. Based on the study it has been reared through collect data that some teachers have not been workshopped in the current curriculum (NCS) and this somehow affects the learners. Learners from rural areas have a problem in understanding English language. Lack of educational facilities like libraries also have a negative impact in learner’s progress. Learners who came from Junior Secondary Schools to High schools are not ready and this gives High School teachers a big task to mould them to be ready for matric. It is recommended that parental involvement is vital in their children’s education so as to see their progress and to develop the teacher-parent locomotives learners need to be engaged in Educational activities like debates, public speaking, conducting so as to improve their communication skills. Educators should give more writing and reading exercises to learners so as to minimize the number of learners who are unable to write in Matric. , Thesis (MMED) -- Faculty of Educational Sciences, 2013
- Full Text:
- Date Issued: 2013
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