M3: Mining Mini-Halos with MeerKAT
- Authors: Trehaeven, Keegan Somerset
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424754 , vital:72181
- Description: This work aims to showcase the MeerKAT telescope’s capabilities and related calibration and imaging software in studying the emission of radio mini-halos. These diffuse radio synchrotron sources surround a Brightest Cluster Galaxy (BCG) in relatively relaxed clusters out to a few 100 kpc in size. They are difficult to image because of their relatively low surface brightness and small angular size. Hence, they could not be studied in great detail by previous generations of radio telescopes and much about their nature, particularly the exact production mechanism, is not yet fully understood. Thus, for the first time, MeerKAT observed a sample of five galaxy clusters to investigate the central radio mini-halo in each. Studying these sources requires the deepest images generated from the data and the effective subtraction of any projected sources obscuring or contaminating the underlying diffuse emission. Therefore, I describe the data reduction used to create third-generation calibrated, primary beam corrected, point source subtracted Stokes I L-band continuum images of these clusters. For first- and second-generation calibration, I use the CARACal pipeline, which implements software optimised explicitly for MeerKAT data. For third-generation calibration, I use the faceted approach of killMS and DDFacet, and then I perform visibility-plane point source subtraction to disentangle the compact and diffuse emissions. I then measured the size, flux density, in-band spectral properties, and radio power of the central mini-halos. I present the first new mini-halo detection by MeerKAT (MACS J2140.2-2339, Trehaeven et al. accepted), the first spectral index maps of these mini-halos, which show very interesting distributions, and a ∼100 kpc II southern extension to the ACO 3444 mini-halo previously unseen in archival VLA data. Thereafter, I present a multi-wavelength case study for two complementary mini-halos from our sample and show via a radio-to-X-ray spatial correlation test that they might be caused by different particle (re)-acceleration mechanisms. Through these initial science results, I have shown that future observations of radio mini-halos with MeerKAT are an exciting prospect that can lead to a better understanding of the fundamental physics behind these sources. , Thesis (MSc) -- Faculty of Science, Physics and Electronics, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Trehaeven, Keegan Somerset
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424754 , vital:72181
- Description: This work aims to showcase the MeerKAT telescope’s capabilities and related calibration and imaging software in studying the emission of radio mini-halos. These diffuse radio synchrotron sources surround a Brightest Cluster Galaxy (BCG) in relatively relaxed clusters out to a few 100 kpc in size. They are difficult to image because of their relatively low surface brightness and small angular size. Hence, they could not be studied in great detail by previous generations of radio telescopes and much about their nature, particularly the exact production mechanism, is not yet fully understood. Thus, for the first time, MeerKAT observed a sample of five galaxy clusters to investigate the central radio mini-halo in each. Studying these sources requires the deepest images generated from the data and the effective subtraction of any projected sources obscuring or contaminating the underlying diffuse emission. Therefore, I describe the data reduction used to create third-generation calibrated, primary beam corrected, point source subtracted Stokes I L-band continuum images of these clusters. For first- and second-generation calibration, I use the CARACal pipeline, which implements software optimised explicitly for MeerKAT data. For third-generation calibration, I use the faceted approach of killMS and DDFacet, and then I perform visibility-plane point source subtraction to disentangle the compact and diffuse emissions. I then measured the size, flux density, in-band spectral properties, and radio power of the central mini-halos. I present the first new mini-halo detection by MeerKAT (MACS J2140.2-2339, Trehaeven et al. accepted), the first spectral index maps of these mini-halos, which show very interesting distributions, and a ∼100 kpc II southern extension to the ACO 3444 mini-halo previously unseen in archival VLA data. Thereafter, I present a multi-wavelength case study for two complementary mini-halos from our sample and show via a radio-to-X-ray spatial correlation test that they might be caused by different particle (re)-acceleration mechanisms. Through these initial science results, I have shown that future observations of radio mini-halos with MeerKAT are an exciting prospect that can lead to a better understanding of the fundamental physics behind these sources. , Thesis (MSc) -- Faculty of Science, Physics and Electronics, 2023
- Full Text:
- Date Issued: 2023-10-13
Assessing the density and distribution of spotted hyaenas (Crocuta crocuta) in Hluhluwe–iMfolozi Park, KwaZulu-Natal, South Africa
- Authors: Roberts, Peter Jean
- Date: 2022-04-06
- Subjects: Spotted hyena Home range South Africa Hluhluwe Game Reserve , Spotted hyena Habitat South Africa Hluhluwe Game Reserve , Animal population density South Africa Hluhluwe Game Reserve , Scouting cameras , Home range (Animal geography) , Spatially-explicit mark recapture (SECR)
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/292681 , vital:57006
- Description: Protected areas are becoming increasingly isolated refugia for large carnivores and are critical for their survival. Spotted hyaenas (Crocuta crocuta) have, for centuries, been ‘managed’ as problem causing animals and their conservation has been largely overlooked. To preserve a population, it is paramount to understand its distribution and abundance through reliable and cost-effective monitoring techniques. My study estimated the density of spotted hyaenas and their use of space in Hluhluwe–iMfolozi Park (HiP), South Africa. I compared camera trap by-catch data and call-up surveys between 2013–2018 to assess spotted hyaena densities. The camera trap data estimated an average of 16.72 (SD: ±2.22) hyaenas per 100 km2 between 2013–2018, with an annual estimated high of 19.01 in 2018 and a low of 12.77 in 2015. The call-up surveys consistently produced lower estimates than those obtained from the camera trap data. These results highlight the importance of calibrating the response probability factor for call-up surveys to maintain precision. The space use of spotted hyaenas was analysed using the photo-capture data obtained during the same six-year period, to produce individual 100% Minimum Convex Polygon’s (MCPs). Seven clan territories were identified from individual female home ranges that overlapped by more than 66% of their MCPs. Territory sizes were similar to historical estimates for the park, with averages of 13.96 (SD: ±6.48) km2 in Hluhluwe and 34.61 (SD: ±23.87) km2 in iMfolozi. My study successfully used by-catch camera data to calculate annual density estimates and investigate the spatial use patterns for spotted hyaenas in HiP. I demonstrate that this approach is cost-effective and reliable for calculating density estimates. Conservation practitioners should take heed of the advancements in technology and analytical capacity now available to them to improve monitoring efforts. My study specifically calls for collaborative efforts to use existing camera trap data to improve regional estimates and population trends of spotted hyaenas across their range. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Roberts, Peter Jean
- Date: 2022-04-06
- Subjects: Spotted hyena Home range South Africa Hluhluwe Game Reserve , Spotted hyena Habitat South Africa Hluhluwe Game Reserve , Animal population density South Africa Hluhluwe Game Reserve , Scouting cameras , Home range (Animal geography) , Spatially-explicit mark recapture (SECR)
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/292681 , vital:57006
- Description: Protected areas are becoming increasingly isolated refugia for large carnivores and are critical for their survival. Spotted hyaenas (Crocuta crocuta) have, for centuries, been ‘managed’ as problem causing animals and their conservation has been largely overlooked. To preserve a population, it is paramount to understand its distribution and abundance through reliable and cost-effective monitoring techniques. My study estimated the density of spotted hyaenas and their use of space in Hluhluwe–iMfolozi Park (HiP), South Africa. I compared camera trap by-catch data and call-up surveys between 2013–2018 to assess spotted hyaena densities. The camera trap data estimated an average of 16.72 (SD: ±2.22) hyaenas per 100 km2 between 2013–2018, with an annual estimated high of 19.01 in 2018 and a low of 12.77 in 2015. The call-up surveys consistently produced lower estimates than those obtained from the camera trap data. These results highlight the importance of calibrating the response probability factor for call-up surveys to maintain precision. The space use of spotted hyaenas was analysed using the photo-capture data obtained during the same six-year period, to produce individual 100% Minimum Convex Polygon’s (MCPs). Seven clan territories were identified from individual female home ranges that overlapped by more than 66% of their MCPs. Territory sizes were similar to historical estimates for the park, with averages of 13.96 (SD: ±6.48) km2 in Hluhluwe and 34.61 (SD: ±23.87) km2 in iMfolozi. My study successfully used by-catch camera data to calculate annual density estimates and investigate the spatial use patterns for spotted hyaenas in HiP. I demonstrate that this approach is cost-effective and reliable for calculating density estimates. Conservation practitioners should take heed of the advancements in technology and analytical capacity now available to them to improve monitoring efforts. My study specifically calls for collaborative efforts to use existing camera trap data to improve regional estimates and population trends of spotted hyaenas across their range. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2022
- Full Text:
- Date Issued: 2022-04-06
The role of a national system of innovation in facilitating development in South Africa from a comparative BRICS perspective
- Authors: Sibhukwana, Andiswa
- Date: 2022-04-06
- Subjects: BRIC countries , Technological innovations Economic aspects South Africa , Economic development South Africa , Economics Mathematical models , Neoclassical school of economics , South Africa Economic conditions , South Africa Economic policy , National systems of innovation
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/284616 , vital:56079
- Description: The aim of the dissertation was to investigate whether the adoption of a national system of innovation has helped facilitate development in South Africa from a comparative BRICS perspective. South Africa has an expanding focus on science and technology, as per the Science and Technology White Paper (1996). There appeared to be innovation that had left out much of the citizenry. There continued to be poverty, inequality, and joblessness. The study aimed to understand how the NSI approach could be used to foster inclusive and transformative development. The study used a mixed-methods approach. The qualitative aspect of the research focused on an innovation and public policy study which assessed the various policies and initiatives implemented in each of the BRICS countries to drive innovation and foster development. The qualitative aspect of the study found that the innovation paradigm required governments to adopt a more holistic approach to public policy design and analysis. The quantitative aspect of the research focused on a trend, correlation, and regression analysis. The trend analysis revealed that China and Brazil increased their allocation of resources towards R&D compared to the other countries. Brazil is regarded as a social investment state, while China is a developmental state: this means the state plays an extraordinarily strong coordinative and financing role in the NSI. On the other hand, the correlation matrix for South Africa revealed a statistically significant positive linear association between various NSI indicators and human development. This suggested that the innovation benefits are trickling down to the general citizenry. In essence the study articulated key elements of the understanding of current and potential impacts of technological change in productivity and growth, employment and inequality that can be used for policy making. , Thesis (MEcon) -- Faculty of Commerce, Economics and Economic History, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Sibhukwana, Andiswa
- Date: 2022-04-06
- Subjects: BRIC countries , Technological innovations Economic aspects South Africa , Economic development South Africa , Economics Mathematical models , Neoclassical school of economics , South Africa Economic conditions , South Africa Economic policy , National systems of innovation
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/284616 , vital:56079
- Description: The aim of the dissertation was to investigate whether the adoption of a national system of innovation has helped facilitate development in South Africa from a comparative BRICS perspective. South Africa has an expanding focus on science and technology, as per the Science and Technology White Paper (1996). There appeared to be innovation that had left out much of the citizenry. There continued to be poverty, inequality, and joblessness. The study aimed to understand how the NSI approach could be used to foster inclusive and transformative development. The study used a mixed-methods approach. The qualitative aspect of the research focused on an innovation and public policy study which assessed the various policies and initiatives implemented in each of the BRICS countries to drive innovation and foster development. The qualitative aspect of the study found that the innovation paradigm required governments to adopt a more holistic approach to public policy design and analysis. The quantitative aspect of the research focused on a trend, correlation, and regression analysis. The trend analysis revealed that China and Brazil increased their allocation of resources towards R&D compared to the other countries. Brazil is regarded as a social investment state, while China is a developmental state: this means the state plays an extraordinarily strong coordinative and financing role in the NSI. On the other hand, the correlation matrix for South Africa revealed a statistically significant positive linear association between various NSI indicators and human development. This suggested that the innovation benefits are trickling down to the general citizenry. In essence the study articulated key elements of the understanding of current and potential impacts of technological change in productivity and growth, employment and inequality that can be used for policy making. , Thesis (MEcon) -- Faculty of Commerce, Economics and Economic History, 2022
- Full Text:
- Date Issued: 2022-04-06
Spatial modelling of accessibility to tuberculosis treatment: the case of Ngaka Modiri Molema District
- Authors: Ramotsongwa, Karabo Naome
- Date: 2022-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55435 , vital:52000
- Description: Accessibility to healthcare refers to the availability, or the provision of healthcare-byhealthcare professionals and stakeholders and individuals' ability to obtain care and treatment. It affects overall physical, social, and mental health; disease and disability prevention; detection and treatment of health conditions; standard of living; preventable death; and life expectancy, and it is crucial to the performance of health care systems around the world. If healthcare services are available and are in sufficient supply, people will be able to seek health care, and a population will have access to services. The leading cause of death globally is Tuberculosis (TB) and South Africa is amongst the top 5 countries most affected by TB. This is aggravated by high HIV/AIDS statistics. Children belowthe age of 4, between the ages of 4- 15, and women and men of working ages are highly affected by TB and it is the primary cause of death in these groups in the Ngaka Modiri Molema District. This study used study tools like Spatial Modelling, Geographic Information Systems and software like ArcGIS 10.5, TerrSet IDRISI 18.30, and secondary data from the North West Departmentof Health (Tier.net &DHIS) and also TB patients’ home addresses to investigate the accessibility of TB treatment in Ngaka Modiri Molema, in order to spatially visualize the distribution of a communicable disease like TB and public healthcare facilities in the Ngaka Modiri Molema (NMM) District and suggest optimum sites for hospital facilities. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Ramotsongwa, Karabo Naome
- Date: 2022-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55435 , vital:52000
- Description: Accessibility to healthcare refers to the availability, or the provision of healthcare-byhealthcare professionals and stakeholders and individuals' ability to obtain care and treatment. It affects overall physical, social, and mental health; disease and disability prevention; detection and treatment of health conditions; standard of living; preventable death; and life expectancy, and it is crucial to the performance of health care systems around the world. If healthcare services are available and are in sufficient supply, people will be able to seek health care, and a population will have access to services. The leading cause of death globally is Tuberculosis (TB) and South Africa is amongst the top 5 countries most affected by TB. This is aggravated by high HIV/AIDS statistics. Children belowthe age of 4, between the ages of 4- 15, and women and men of working ages are highly affected by TB and it is the primary cause of death in these groups in the Ngaka Modiri Molema District. This study used study tools like Spatial Modelling, Geographic Information Systems and software like ArcGIS 10.5, TerrSet IDRISI 18.30, and secondary data from the North West Departmentof Health (Tier.net &DHIS) and also TB patients’ home addresses to investigate the accessibility of TB treatment in Ngaka Modiri Molema, in order to spatially visualize the distribution of a communicable disease like TB and public healthcare facilities in the Ngaka Modiri Molema (NMM) District and suggest optimum sites for hospital facilities. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2022
- Full Text:
- Date Issued: 2022-04
Strategies to improve implementation of curriculum and assessment policy statement (CAPS) in Secondary Schools in Eastern Cape Province
- Authors: Mafilika, Zamikhaya
- Date: 2022-00
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/11260/10676 , vital:75212
- Description: The study was conducted in one education district of the Eastern Cape Province. The study aimed to explore the challenges experienced by teachers and learners concerning the implementation of CAPS in secondary schools of the Eastern Cape Province. The study reviewed to improve the implementation of CAPS in secondary schools. The cognitive constructivist theory was used in this study. The study adopted a qualitative research approach through which a case study design was chosen. In-depth individual interviews were conducted to attain rich and accurate data from ten teachers, five principals, five heads of departments and five learners who participated in this study: from five secondary schools of Chris Hani West district. A total of nine themes became observable in this study through the analysis of the interviews. One of the key findings was that the Department of Basic Education did not involve teachers when changing the curriculum. The study concludes that issues such as learner-teacher ratio, overcrowded classrooms, insufficient resources, promotion and progression policy, syllabus coverage, lack of teachers with inclusive education, lack of parental involvement in learners’ work and Language of Learning and Teaching hinder the quality of teaching and learning processes. It was suggested that the Department of Basic Education, parents, principals and learners should collaborate to address the hindrances to effective teaching and learning. , Thesis (Masters) -- Faculty of Education, 2022
- Full Text:
- Date Issued: 2022-00
- Authors: Mafilika, Zamikhaya
- Date: 2022-00
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/11260/10676 , vital:75212
- Description: The study was conducted in one education district of the Eastern Cape Province. The study aimed to explore the challenges experienced by teachers and learners concerning the implementation of CAPS in secondary schools of the Eastern Cape Province. The study reviewed to improve the implementation of CAPS in secondary schools. The cognitive constructivist theory was used in this study. The study adopted a qualitative research approach through which a case study design was chosen. In-depth individual interviews were conducted to attain rich and accurate data from ten teachers, five principals, five heads of departments and five learners who participated in this study: from five secondary schools of Chris Hani West district. A total of nine themes became observable in this study through the analysis of the interviews. One of the key findings was that the Department of Basic Education did not involve teachers when changing the curriculum. The study concludes that issues such as learner-teacher ratio, overcrowded classrooms, insufficient resources, promotion and progression policy, syllabus coverage, lack of teachers with inclusive education, lack of parental involvement in learners’ work and Language of Learning and Teaching hinder the quality of teaching and learning processes. It was suggested that the Department of Basic Education, parents, principals and learners should collaborate to address the hindrances to effective teaching and learning. , Thesis (Masters) -- Faculty of Education, 2022
- Full Text:
- Date Issued: 2022-00
Inkcitha nzila nobomi obutsha (The release of the widow and life after mourning): Xhosa widows and citizenship
- Jimlongo, Gcotyelwa Nomxolisi
- Authors: Jimlongo, Gcotyelwa Nomxolisi
- Date: 2021-10-29
- Subjects: Widows South Africa Eastern Cape , Women, Black South Africa Eastern Cape , Xhosa (African people) South Africa Eastern Cape , Widows Social conditions , Widowhood Psychological aspects South Africa Eastern Cape , Widowhood Economic aspects South Africa Eastern Cape , Widowhood Social aspects South Africa Eastern Cape , Mourning customs South Africa Eastern Cape , Feminist economics South Africa Eastern Cape
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192220 , vital:45206
- Description: This study examines the everyday conceptions and navigations of citizenship by Xhosa widows. It examines widows’ own understandings and experiences of citizenship once the official mourning period, known amongst amaXhosa as ukuzila, has ended. The study draws from 14 interviews with Xhosa widows from the Amalinda, Tsholomnqa, Mdantsane, Magcumeni, KwaNonkcampa, and Dimbaza areas in the Eastern Cape, South Africa. This thesis contextualises claims to widowhood in the context of democratic South Africa, and the various ways in which widowed women conceptualise their lives after ukuzila. While ukuzila itself is written about in the literature, the contentious claims to widowhood and the ways in which women come to make sense of their lives in the post-mourning period remains largely unexplored. Interviews were conducted with women who had undertaken customary and/or civil marriages, had divorced or separated from their partners, or had cohabited. They reveal that widowhood is tenuous and as such, remains contested and contestable. The study demonstrates that much of the claims to widowhood are made because of the undeniable labour that women perform during the partnerships, where they are the primary economic providers. The study shows that whether in the formal and informal sector, women have been central in building the economic livelihoods of their families. In the post-mourning period, the theme of ukuhlala (to stay) that is articulated by widows, shows that they choose to remain in their marital homes to protect what they have laboured for. The findings demonstrate that the key to ‘good’ widowhood is intricately linked to ‘good’ motherhood. For Xhosa widows, much of their decision-making, and livelihood strategies, rests on how they craft good livelihoods for their families. These include a negotiation of feminist economies with woman-centred networks, a reliance on spirituality, as well as negotiations for dignity and respect within the homestead through the protection and maintenance of what they have built over the years. , Thesis (MA) -- Faculty of Humanities, Political and International Studies, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Jimlongo, Gcotyelwa Nomxolisi
- Date: 2021-10-29
- Subjects: Widows South Africa Eastern Cape , Women, Black South Africa Eastern Cape , Xhosa (African people) South Africa Eastern Cape , Widows Social conditions , Widowhood Psychological aspects South Africa Eastern Cape , Widowhood Economic aspects South Africa Eastern Cape , Widowhood Social aspects South Africa Eastern Cape , Mourning customs South Africa Eastern Cape , Feminist economics South Africa Eastern Cape
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192220 , vital:45206
- Description: This study examines the everyday conceptions and navigations of citizenship by Xhosa widows. It examines widows’ own understandings and experiences of citizenship once the official mourning period, known amongst amaXhosa as ukuzila, has ended. The study draws from 14 interviews with Xhosa widows from the Amalinda, Tsholomnqa, Mdantsane, Magcumeni, KwaNonkcampa, and Dimbaza areas in the Eastern Cape, South Africa. This thesis contextualises claims to widowhood in the context of democratic South Africa, and the various ways in which widowed women conceptualise their lives after ukuzila. While ukuzila itself is written about in the literature, the contentious claims to widowhood and the ways in which women come to make sense of their lives in the post-mourning period remains largely unexplored. Interviews were conducted with women who had undertaken customary and/or civil marriages, had divorced or separated from their partners, or had cohabited. They reveal that widowhood is tenuous and as such, remains contested and contestable. The study demonstrates that much of the claims to widowhood are made because of the undeniable labour that women perform during the partnerships, where they are the primary economic providers. The study shows that whether in the formal and informal sector, women have been central in building the economic livelihoods of their families. In the post-mourning period, the theme of ukuhlala (to stay) that is articulated by widows, shows that they choose to remain in their marital homes to protect what they have laboured for. The findings demonstrate that the key to ‘good’ widowhood is intricately linked to ‘good’ motherhood. For Xhosa widows, much of their decision-making, and livelihood strategies, rests on how they craft good livelihoods for their families. These include a negotiation of feminist economies with woman-centred networks, a reliance on spirituality, as well as negotiations for dignity and respect within the homestead through the protection and maintenance of what they have built over the years. , Thesis (MA) -- Faculty of Humanities, Political and International Studies, 2021
- Full Text:
- Date Issued: 2021-10-29
Echogenic liposomes for ultrasound-triggered drug delivery
- Authors: Izuchukwu, Ezekiel Charles
- Date: 2021-10
- Subjects: Liposomes , Drug delivery systems , Colon (Anatomy) Cancer Treatment , Transmission electron microscopy , Fourier transform infrared spectroscopy , Liquid chromatography , Echogenic liposomes , Ultrasound-triggered drug delivery
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/10962/188997 , vital:44805
- Description: Colorectal cancer is one of common cancers worldwide. It is the third most diagnosed cancer and the second leading cause of death. The use of 5-fluorouracil (5-FU) alone or in a chemotherapy regime has been the effective treatment of colorectal cancer patients. The efficacy of 5-FU in colorectal cancer treatment is significantly limited by drug resistance, gastrointestinal, and bone marrow toxicity through high-level expression of thymidylate synthase, justifying a need to improve its therapeutic index. Liposomes are colloidal membranes comprising of one or more lipid bilayers enclosing an aqueous core. They have been used to improve the therapeutic index of many anti-cancer drugs by changing drug absorption, elongating biological half-life, reducing metabolism, and reducing toxicity to healthy tissues. Echogenic liposomes are specifically designed to respond to external triggering like ultrasound stimulation by entrapping a gas or an emulsion that can vaporize. A liposome's unique property is that it can entrap both hydrophobic and hydrophilic substances simultaneously in the lipid bilayer and the aqueous core, respectively. These stimuli-responsive liposomes can be triggered externally with ultrasound, to release the chemotherapeutic cargo only at the required site. This research aims to formulate echogenic liposomes encapsulating 5-FU for potential ultrasound triggered release (echogenic). Liposome formulations wereprepared with lipid composition of crude soybean lecithin and cholesterol by thin-filmhydration method and the drug was passively loaded in the formulation. The 5-FU loadedliposomes were evaluated by dynamic light scattering (DLS) for particle size, polydispersityindex, and zeta potential and transmission electron microscopy (TEM) for morphology.Encapsulated liposomal formulations were also evaluated using physicochemical techniquesincluding thermogravimetric analysis (TGA), differential scanning calorimetry (DSC),Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). Theencapsulation efficiency and release kinetics were studied using a validated high-performanceliquid chromatography (HPLC) method. Echogenic properties were explored by entrapping abiocompatible gas (argon) at the same time as the drug (5-FU) using a pressure/freezemethodology. The liposomal formulations were typically spherical with a size of about 150 nmand encapsulation efficiency of 62%. Low-frequency ultrasound (20 kHz) was used to triggerthe drug release from the complete formulation at 10%, 15%, and 20% amplitude and exposuretime of 5 min and 10 min. The rate of drug release from the nano-carrier was a function of theultrasound amplitude and exposure time and reached a maximum of 65% release under theconditions investigated. The cumulative release was investigated, with and without theapplication of ultrasound. It was demonstrated that the application of ultrasound resulted in complete release (99%) after 12 h while this dropped to 70% without ultrasound. These results are encouraging for optimizing ultrasound parameters for triggered and controlled release of the 5-FU, for conditions such as the management of cancer where low-power ultrasound can be applied. , Thesis (MSc) -- Faculty of Science, Chemistry, 2021
- Full Text:
- Date Issued: 2021-10
- Authors: Izuchukwu, Ezekiel Charles
- Date: 2021-10
- Subjects: Liposomes , Drug delivery systems , Colon (Anatomy) Cancer Treatment , Transmission electron microscopy , Fourier transform infrared spectroscopy , Liquid chromatography , Echogenic liposomes , Ultrasound-triggered drug delivery
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/10962/188997 , vital:44805
- Description: Colorectal cancer is one of common cancers worldwide. It is the third most diagnosed cancer and the second leading cause of death. The use of 5-fluorouracil (5-FU) alone or in a chemotherapy regime has been the effective treatment of colorectal cancer patients. The efficacy of 5-FU in colorectal cancer treatment is significantly limited by drug resistance, gastrointestinal, and bone marrow toxicity through high-level expression of thymidylate synthase, justifying a need to improve its therapeutic index. Liposomes are colloidal membranes comprising of one or more lipid bilayers enclosing an aqueous core. They have been used to improve the therapeutic index of many anti-cancer drugs by changing drug absorption, elongating biological half-life, reducing metabolism, and reducing toxicity to healthy tissues. Echogenic liposomes are specifically designed to respond to external triggering like ultrasound stimulation by entrapping a gas or an emulsion that can vaporize. A liposome's unique property is that it can entrap both hydrophobic and hydrophilic substances simultaneously in the lipid bilayer and the aqueous core, respectively. These stimuli-responsive liposomes can be triggered externally with ultrasound, to release the chemotherapeutic cargo only at the required site. This research aims to formulate echogenic liposomes encapsulating 5-FU for potential ultrasound triggered release (echogenic). Liposome formulations wereprepared with lipid composition of crude soybean lecithin and cholesterol by thin-filmhydration method and the drug was passively loaded in the formulation. The 5-FU loadedliposomes were evaluated by dynamic light scattering (DLS) for particle size, polydispersityindex, and zeta potential and transmission electron microscopy (TEM) for morphology.Encapsulated liposomal formulations were also evaluated using physicochemical techniquesincluding thermogravimetric analysis (TGA), differential scanning calorimetry (DSC),Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). Theencapsulation efficiency and release kinetics were studied using a validated high-performanceliquid chromatography (HPLC) method. Echogenic properties were explored by entrapping abiocompatible gas (argon) at the same time as the drug (5-FU) using a pressure/freezemethodology. The liposomal formulations were typically spherical with a size of about 150 nmand encapsulation efficiency of 62%. Low-frequency ultrasound (20 kHz) was used to triggerthe drug release from the complete formulation at 10%, 15%, and 20% amplitude and exposuretime of 5 min and 10 min. The rate of drug release from the nano-carrier was a function of theultrasound amplitude and exposure time and reached a maximum of 65% release under theconditions investigated. The cumulative release was investigated, with and without theapplication of ultrasound. It was demonstrated that the application of ultrasound resulted in complete release (99%) after 12 h while this dropped to 70% without ultrasound. These results are encouraging for optimizing ultrasound parameters for triggered and controlled release of the 5-FU, for conditions such as the management of cancer where low-power ultrasound can be applied. , Thesis (MSc) -- Faculty of Science, Chemistry, 2021
- Full Text:
- Date Issued: 2021-10
The enforcement of code conduct in local government: the case of O R Tambo District.
- Authors: Tyali, Gcobani Sonwabile
- Date: 2021-09
- Subjects: Public administration--Moral and ethical aspects , Civil service ethics
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21300 , vital:48381
- Description: The post-apartheid transformative agenda for local government in South Africa (SA) was built on a system of new key performance areas for public employees. The problems of accountability and transparency in local government finance management, as well as good governance and the capacity building of those public officials designated to support local development, were among them. Over the years, the conduct of public officials has received more scrutiny in the media as well as in academic research. Ethics management therefore, has garnered more attention as well especially in the fight against corruption. The premise is that, if ethics management can be institutionalised public officials can become more effective and discharge their duties with respect for public resources. The imperative for the implementation of an ethical framework was also based on the need to ensure inclusive development which can be enhanced by ensuring accountability by local government functionaries. In this regard, the conduct of municipal functionaries and its regulation based on the code of conduct takes centre stage. The study contextualises ethics management and its efficacy with specific reference to the code of conduct and its role in the prevalence of unethical conduct. The results reveal glaring inconsistencies in the implementation of the code of conduct and a myriad of challenges rendering ethics management ineffective. , Thesis (MA) (Administration) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-09
- Authors: Tyali, Gcobani Sonwabile
- Date: 2021-09
- Subjects: Public administration--Moral and ethical aspects , Civil service ethics
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21300 , vital:48381
- Description: The post-apartheid transformative agenda for local government in South Africa (SA) was built on a system of new key performance areas for public employees. The problems of accountability and transparency in local government finance management, as well as good governance and the capacity building of those public officials designated to support local development, were among them. Over the years, the conduct of public officials has received more scrutiny in the media as well as in academic research. Ethics management therefore, has garnered more attention as well especially in the fight against corruption. The premise is that, if ethics management can be institutionalised public officials can become more effective and discharge their duties with respect for public resources. The imperative for the implementation of an ethical framework was also based on the need to ensure inclusive development which can be enhanced by ensuring accountability by local government functionaries. In this regard, the conduct of municipal functionaries and its regulation based on the code of conduct takes centre stage. The study contextualises ethics management and its efficacy with specific reference to the code of conduct and its role in the prevalence of unethical conduct. The results reveal glaring inconsistencies in the implementation of the code of conduct and a myriad of challenges rendering ethics management ineffective. , Thesis (MA) (Administration) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-09
An investigation into the use of a consumer incentive to encourage recycling in South Africa
- Authors: Conway, John Charles
- Date: 2021-04
- Subjects: Recycling (Waste, etc.) -- Economic aspects , Consumption (Economics) -- South Africa , Consumer behavior
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/51096 , vital:43208
- Description: The focus of this study is the factors that influence recycling behaviours, particularly whether incentives are likely to change consumers’ recycling behaviours in South Africa. Africa is said to become the most polluted continent within a few decades. Three of the largest metropoles in South African are likely to run out of landfill space within the next ten years. Waste streams provide considerable opportunity if waste can be safely collected and either reused, recycled, or recovered, but extracting value from the waste streams is costly and difficult. Consumers need to separate waste at source to improve the efficacy of the recycling stream, yet South Africans do not separate waste at source as a norm. The question that arises then is would an incentive improve South Africans’ willingness to recycle? This study tried to determine if incentives are likely to change consumers’ recycling behaviours in South Africa. It explored the relationship between factors that influence recycling behaviours grounded in Taylor and Todd's (1995) extension of Ajzen's (1991) Theory Of Planned Behaviour. A quantitative survey design, using both online and face to face questionnaires, was used to collect data from a cross section of randomly selected consumers. The research determines that the call to address waste management infrastructure and facilities, is indeed correct. It further confirms previous research findings that an incentive alone is not enough to change recycling behaviours as it will not negate other environmental factors. Lower income groups are more conscientious about recycling and may be enticed to participate in the recycling industry through an incentive to improve their income. , Thesis (MBA) -- Faculty of Business and Economic Sciences, Business Administration, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Conway, John Charles
- Date: 2021-04
- Subjects: Recycling (Waste, etc.) -- Economic aspects , Consumption (Economics) -- South Africa , Consumer behavior
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/51096 , vital:43208
- Description: The focus of this study is the factors that influence recycling behaviours, particularly whether incentives are likely to change consumers’ recycling behaviours in South Africa. Africa is said to become the most polluted continent within a few decades. Three of the largest metropoles in South African are likely to run out of landfill space within the next ten years. Waste streams provide considerable opportunity if waste can be safely collected and either reused, recycled, or recovered, but extracting value from the waste streams is costly and difficult. Consumers need to separate waste at source to improve the efficacy of the recycling stream, yet South Africans do not separate waste at source as a norm. The question that arises then is would an incentive improve South Africans’ willingness to recycle? This study tried to determine if incentives are likely to change consumers’ recycling behaviours in South Africa. It explored the relationship between factors that influence recycling behaviours grounded in Taylor and Todd's (1995) extension of Ajzen's (1991) Theory Of Planned Behaviour. A quantitative survey design, using both online and face to face questionnaires, was used to collect data from a cross section of randomly selected consumers. The research determines that the call to address waste management infrastructure and facilities, is indeed correct. It further confirms previous research findings that an incentive alone is not enough to change recycling behaviours as it will not negate other environmental factors. Lower income groups are more conscientious about recycling and may be enticed to participate in the recycling industry through an incentive to improve their income. , Thesis (MBA) -- Faculty of Business and Economic Sciences, Business Administration, 2021
- Full Text:
- Date Issued: 2021-04
An exploration of the (re)production of femininity in netball spaces: the case of Nelson Mandela Bay, Eastern Cape
- Authors: Phuza, Nobubele
- Date: 2020-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55150 , vital:49163
- Description: Since its introduction in 1920, Netball has reflected and reinforced appropriate ideas of female physicality and a culturally valued femininity. It is socially accepted as an appropriate sport for women evidenced by its promotion for girls in schools, the number of teams, clubs and leagues in existence and the invisibility of men’s netball in the media and society. Existing literature from Australian and New Zealand scholars in the sociology of sport and leisure consistently makes the argument that the meaning of femininity and the expected attributes thereof, are powerfully presented in the bodily performances that occur in netball. “You learn to be a woman, female bonding, female submission and the like. All while seeming to do nothing but throw a ball around.” The aim of this dissertation is to contextualize the conversation around femininity and netball for South Africa, specifically Nelson Mandela Bay. The research focuses on how netball remains an island of femininity in the sea of masculine sport. I draw on individual interviews with twelve (12) competitive netball players and ethnographic field work to examine the meaning of femininity in netball and women’s affinity to it. Using a Bourdieusian-feminist lens, I explain netball spaces as subfields of sport, structured by the configuration of valued capital(s). The findings revealed femininity as a valued capital in netball. It was a compliant femininity, characterised by the need to be aesthetically pleasing, levels of modesty, religiosity and pseudo-fragility. As players accrued netball femininity, they internalized associated dispositions as their own, a habitus. They would transmit and redeposit the habitus through interactions in the field during training sessions and matches. To this end, the dissertation also revealed that the reproduction of femininity in netball was a function of habitus and the reciprocal relationship between bodies and space. , Thesis (MA) -- Faculty of Humanities, School of Governmental and Social Sciences, 2020
- Full Text:
- Date Issued: 2020-04
- Authors: Phuza, Nobubele
- Date: 2020-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55150 , vital:49163
- Description: Since its introduction in 1920, Netball has reflected and reinforced appropriate ideas of female physicality and a culturally valued femininity. It is socially accepted as an appropriate sport for women evidenced by its promotion for girls in schools, the number of teams, clubs and leagues in existence and the invisibility of men’s netball in the media and society. Existing literature from Australian and New Zealand scholars in the sociology of sport and leisure consistently makes the argument that the meaning of femininity and the expected attributes thereof, are powerfully presented in the bodily performances that occur in netball. “You learn to be a woman, female bonding, female submission and the like. All while seeming to do nothing but throw a ball around.” The aim of this dissertation is to contextualize the conversation around femininity and netball for South Africa, specifically Nelson Mandela Bay. The research focuses on how netball remains an island of femininity in the sea of masculine sport. I draw on individual interviews with twelve (12) competitive netball players and ethnographic field work to examine the meaning of femininity in netball and women’s affinity to it. Using a Bourdieusian-feminist lens, I explain netball spaces as subfields of sport, structured by the configuration of valued capital(s). The findings revealed femininity as a valued capital in netball. It was a compliant femininity, characterised by the need to be aesthetically pleasing, levels of modesty, religiosity and pseudo-fragility. As players accrued netball femininity, they internalized associated dispositions as their own, a habitus. They would transmit and redeposit the habitus through interactions in the field during training sessions and matches. To this end, the dissertation also revealed that the reproduction of femininity in netball was a function of habitus and the reciprocal relationship between bodies and space. , Thesis (MA) -- Faculty of Humanities, School of Governmental and Social Sciences, 2020
- Full Text:
- Date Issued: 2020-04
Visual narratives portraying the lived experience of women with invisible illnesses
- Authors: Scholtz, Micaela
- Date: 2020-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55207 , vital:49596
- Description: Stereotypical views and misrepresentation impact on how women experience ‘invisible’ gynaecological illnesses such as endometriosis. Patriarchal society forces a particular set of roles and standards upon women to which they must adhere and thus, a limited understanding exists as to how they experience their lived realities with endometriosis. This study consists of two components. The first component is a theoretical component in which I analyse how a visual narrative approach can be utilised in order to portray the lived experiences of women with an invisible illness. In support of this research I reflect on the work of Frida Kahlo, Georgie Wileman and Ellie Kammer in order to determine how these artists addressed the experiences of their illnesses within visual representation. The second part is the practical component informed by theory, interviews and auto-ethnographic data. This study established that women with endometriosis are largely influenced by the societal expectations placed on women as well as how the female body is represented by the media. By visually presenting the lived realities of women with endometriosis, the misperceptions of the disease and its effects are better understood. This study concludes having created a series of visual narratives which expresses internalised pain and emotions, and makes visible that which is invisible about endometriosis. Furthermore, the practical component challenges the stereotypical ideals and representations of femininity through presenting that which is often deemed as taboo. , Thesis (MA) -- Faculty of Arts, School of Visual and Performing Arts, 2020
- Full Text:
- Date Issued: 2020-04
- Authors: Scholtz, Micaela
- Date: 2020-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55207 , vital:49596
- Description: Stereotypical views and misrepresentation impact on how women experience ‘invisible’ gynaecological illnesses such as endometriosis. Patriarchal society forces a particular set of roles and standards upon women to which they must adhere and thus, a limited understanding exists as to how they experience their lived realities with endometriosis. This study consists of two components. The first component is a theoretical component in which I analyse how a visual narrative approach can be utilised in order to portray the lived experiences of women with an invisible illness. In support of this research I reflect on the work of Frida Kahlo, Georgie Wileman and Ellie Kammer in order to determine how these artists addressed the experiences of their illnesses within visual representation. The second part is the practical component informed by theory, interviews and auto-ethnographic data. This study established that women with endometriosis are largely influenced by the societal expectations placed on women as well as how the female body is represented by the media. By visually presenting the lived realities of women with endometriosis, the misperceptions of the disease and its effects are better understood. This study concludes having created a series of visual narratives which expresses internalised pain and emotions, and makes visible that which is invisible about endometriosis. Furthermore, the practical component challenges the stereotypical ideals and representations of femininity through presenting that which is often deemed as taboo. , Thesis (MA) -- Faculty of Arts, School of Visual and Performing Arts, 2020
- Full Text:
- Date Issued: 2020-04
Investigating water knowledge flow to communities
- Burt, Jane C, Berold, Robert
- Authors: Burt, Jane C , Berold, Robert
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433013 , vital:72923 , xlink:href="https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/KV%20288-11.pdf"
- Description: Those of us who work in water resource management have found that very few knowledge/research resources are accessible to most people. This happens because resources are not disseminated properly (or at all), or because they are inappropriately technicist, or because potential readers are hampered by low education. What is the best way to make water research accessible to as many people as possible and especially to people whose lives would be affected by the research? In the early 1980s an attempt was made to address this issue when Robert Berold edited People's Workbook (EDA 1981), a user-friendly book that presented basic technical information for rural people – not only on water, but also on agriculture, health, building construction, and income generation. The book included real-life interviews, and was disseminated by rural fieldworkers. Perhaps because there was nothing like it at the time, it was enormously popular.
- Full Text:
- Date Issued: 2012
- Authors: Burt, Jane C , Berold, Robert
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433013 , vital:72923 , xlink:href="https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/KV%20288-11.pdf"
- Description: Those of us who work in water resource management have found that very few knowledge/research resources are accessible to most people. This happens because resources are not disseminated properly (or at all), or because they are inappropriately technicist, or because potential readers are hampered by low education. What is the best way to make water research accessible to as many people as possible and especially to people whose lives would be affected by the research? In the early 1980s an attempt was made to address this issue when Robert Berold edited People's Workbook (EDA 1981), a user-friendly book that presented basic technical information for rural people – not only on water, but also on agriculture, health, building construction, and income generation. The book included real-life interviews, and was disseminated by rural fieldworkers. Perhaps because there was nothing like it at the time, it was enormously popular.
- Full Text:
- Date Issued: 2012
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