Community radio as a tool for sport development: a case study of Mdantsane FM.
- Authors: Sifingo, Yamkela
- Date: 2018
- Subjects: Community radio--South Africa--Eastern Cape , Radio in community development--South Africa--Eastern Cape , Sport development
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/19650 , vital:43155
- Description: This study focuses on critically examining the role of community radio in sports development, using Mdantsane FM as a case study. To carry out the study, the researcher employed a mixed research methodology as both qualitative and quantitative research approaches were used. In-depth interviews were conducted with key stakeholders and in addition, two focus groups discussions were conducted consisting of eight individuals in each group. The first focus group was held within the radio station and consisted of radio presenters and news readers. The second focus group was held with the external stakeholders who run sports programmes around Mdantsane community, from both the schools and local leagues and competitions. To try and fully represent the studied community and considering the vast population in Mdantsane, a survey/questionnaire study was also carried out. The research findings revealed that Mdantsane FM Community Radio Station listeners and members of the community are of the views that the radio station is playing a crucial role in driving community sport development programs, fixtures, leagues and tournaments. The sport fraternity feels that the radio station promotes local content and it represents the community it serves. Community sport coverage and announcements are said to be always accepted as the sports department operates with an open door policy, where every community member has the equal right to exercise the presence of the radio station accordingly. , Thesis (M Soc Sc) (Communication) -- University of Fort Hare, 2018
- Full Text:
- Date Issued: 2018
- Authors: Sifingo, Yamkela
- Date: 2018
- Subjects: Community radio--South Africa--Eastern Cape , Radio in community development--South Africa--Eastern Cape , Sport development
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/19650 , vital:43155
- Description: This study focuses on critically examining the role of community radio in sports development, using Mdantsane FM as a case study. To carry out the study, the researcher employed a mixed research methodology as both qualitative and quantitative research approaches were used. In-depth interviews were conducted with key stakeholders and in addition, two focus groups discussions were conducted consisting of eight individuals in each group. The first focus group was held within the radio station and consisted of radio presenters and news readers. The second focus group was held with the external stakeholders who run sports programmes around Mdantsane community, from both the schools and local leagues and competitions. To try and fully represent the studied community and considering the vast population in Mdantsane, a survey/questionnaire study was also carried out. The research findings revealed that Mdantsane FM Community Radio Station listeners and members of the community are of the views that the radio station is playing a crucial role in driving community sport development programs, fixtures, leagues and tournaments. The sport fraternity feels that the radio station promotes local content and it represents the community it serves. Community sport coverage and announcements are said to be always accepted as the sports department operates with an open door policy, where every community member has the equal right to exercise the presence of the radio station accordingly. , Thesis (M Soc Sc) (Communication) -- University of Fort Hare, 2018
- Full Text:
- Date Issued: 2018
Evaluating metabolism-induced toxicity using a non-hepatic cell line
- Authors: Weyers, Carli
- Date: 2018
- Subjects: Cytochrome P-450 , Drugs Metabolism , Drugs Design
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/61950 , vital:28087
- Description: The drug discovery pipeline is a complicated process taking roughly 15 years to complete, costing in excess of $1 billion per new chemical entity. It has been estimated that for every 100, 000 promising hit or lead compounds, only one will make it onto the market due to numerous drug candidates being discarded because of many complications. One such complication is metabolism-induced toxicity. Accordingly, an early understanding of the metabolism of any new chemical entity is becoming an integral part of the pipeline. In order to explore this, various methods have been developed including in silico and in vitro techniques. One such method involves performing cell viability assays on human liver cancer cell lines, which overexpress specific metabolic cytochrome P450 enzymes. If a toxic metabolite is produced it would result in reduced cell viability of the transformed cell line in comparison to a control. Since the liver is the primary site of metabolism in the human body, we were curious as to the extent to which background metabolism may play a role in the degree to which toxic metabolites would be produced in these cell lines. The aim of this project, therefore, was to establish if a non-hepatic cell-based system which overexpresses CYP3A4 could be used to detect the metabolism and any subsequent toxicity of compounds which have been reported to be substrates of the CYP450 enzyme. The HEK293 cell line was stably transfected with a plasmid vector for human CYP3A4 to create a model overexpression system for our metabolism studies. The activity of the enzyme was confirmed using the substrate, 7-benzyloxy-4-trifluoromethyl-coumarin. Subsequently, cytotoxicity testing was done on four known pharmaceuticals reported to generate toxic metabolites in hepatic cell-based assays. In silico metabolic predictions on the four known compounds were performed and compared to the results of published literature. Finally, the metabolism of one compound was studied using a combination of high performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS) in order to detect predicted metabolites. We observed no change in cellular toxicity nor did we detect the formation of metabolites, even though the overexpressed CYP3A4 enzyme was active. The results suggest that caution should be taken when interpreting the results of cell-based metabolism studies, and background metabolism may play a significant role in the data. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2018
- Full Text:
- Date Issued: 2018
- Authors: Weyers, Carli
- Date: 2018
- Subjects: Cytochrome P-450 , Drugs Metabolism , Drugs Design
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/61950 , vital:28087
- Description: The drug discovery pipeline is a complicated process taking roughly 15 years to complete, costing in excess of $1 billion per new chemical entity. It has been estimated that for every 100, 000 promising hit or lead compounds, only one will make it onto the market due to numerous drug candidates being discarded because of many complications. One such complication is metabolism-induced toxicity. Accordingly, an early understanding of the metabolism of any new chemical entity is becoming an integral part of the pipeline. In order to explore this, various methods have been developed including in silico and in vitro techniques. One such method involves performing cell viability assays on human liver cancer cell lines, which overexpress specific metabolic cytochrome P450 enzymes. If a toxic metabolite is produced it would result in reduced cell viability of the transformed cell line in comparison to a control. Since the liver is the primary site of metabolism in the human body, we were curious as to the extent to which background metabolism may play a role in the degree to which toxic metabolites would be produced in these cell lines. The aim of this project, therefore, was to establish if a non-hepatic cell-based system which overexpresses CYP3A4 could be used to detect the metabolism and any subsequent toxicity of compounds which have been reported to be substrates of the CYP450 enzyme. The HEK293 cell line was stably transfected with a plasmid vector for human CYP3A4 to create a model overexpression system for our metabolism studies. The activity of the enzyme was confirmed using the substrate, 7-benzyloxy-4-trifluoromethyl-coumarin. Subsequently, cytotoxicity testing was done on four known pharmaceuticals reported to generate toxic metabolites in hepatic cell-based assays. In silico metabolic predictions on the four known compounds were performed and compared to the results of published literature. Finally, the metabolism of one compound was studied using a combination of high performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS) in order to detect predicted metabolites. We observed no change in cellular toxicity nor did we detect the formation of metabolites, even though the overexpressed CYP3A4 enzyme was active. The results suggest that caution should be taken when interpreting the results of cell-based metabolism studies, and background metabolism may play a significant role in the data. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2018
- Full Text:
- Date Issued: 2018
Exploring para-thiophenols to expand the SAR of antimalarial 3-indolylethanones
- Authors: Chisango, Ruramai Lissa
- Date: 2018
- Subjects: Antimalarials , Malaria Chemotherapy , Thiols , Plasmodium falciparum , Blood-brain barrier
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/63515 , vital:28428
- Description: According to the WHO, malaria is responsible for over half a million deaths annually especially in populations from disadvantaged settings. Although there has been a documented improvement in the mortality rates, malaria has proved to be a global emergency. Mostly affecting the poor population, this disease is perpetuating a vicious cycle of poverty in the developing world as current preventive measures are not adequate unless adopted in addition to effective treatment. However, there has been a worldwide increase in resistance to available treatment which presents a need for novel, affordable treatment. A study conducted in our laboratory identified two hit thiophenol containing compounds 2.24 and 2.25. These molecules provided initial insight into the SAR and potential pharmacophore of this class of compounds. We decided to further explore these compounds by making bioisosteric replacements to optimize the structure as we monitor the effect of these modifications on the anti-plasmodial activity. The synthetic pathway to form the target compounds of our study comprised of three steps which were initiated by the Friedel-Crafts acetylation of the indoles resulting in compounds 3.5 - 3.7. A bromination step followed which yielded the -bromo ketones (3.8 - 3.11). Some of the thiophenols (3.14 and 3.16) were not readily available in our laboratory and so were synthesized for the final synthetic step. This step involved the nucleophilic displacement of the -bromine to generate the -aryl substituted 3-indolylethanones (3.17 - 3.27). The thioethers displayed improved antimalarial activity from 2.24 and 2.25 against the chloroquine sensitive 3D7 Plasmodium falciparum strain. In addition, these compounds were non-toxic against HeLa cells which indicated this potential novel class of antimalarials is selective for the malaria parasite as hypothesized in the previous study conducted in our laboratory. In an attempt to predict the bioavailability of some of our compounds, in silico studies were conducted revealing that these compounds could be passively absorbed by the gastrointestinal tract, a positive result for bioavailability purposes. However, results from these studies indicate that modifications of these compounds would be necessary to allow for permeation through the blood brain barrier (BBB) for instances when the patient has cerebral malaria. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2018
- Full Text:
- Date Issued: 2018
- Authors: Chisango, Ruramai Lissa
- Date: 2018
- Subjects: Antimalarials , Malaria Chemotherapy , Thiols , Plasmodium falciparum , Blood-brain barrier
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/63515 , vital:28428
- Description: According to the WHO, malaria is responsible for over half a million deaths annually especially in populations from disadvantaged settings. Although there has been a documented improvement in the mortality rates, malaria has proved to be a global emergency. Mostly affecting the poor population, this disease is perpetuating a vicious cycle of poverty in the developing world as current preventive measures are not adequate unless adopted in addition to effective treatment. However, there has been a worldwide increase in resistance to available treatment which presents a need for novel, affordable treatment. A study conducted in our laboratory identified two hit thiophenol containing compounds 2.24 and 2.25. These molecules provided initial insight into the SAR and potential pharmacophore of this class of compounds. We decided to further explore these compounds by making bioisosteric replacements to optimize the structure as we monitor the effect of these modifications on the anti-plasmodial activity. The synthetic pathway to form the target compounds of our study comprised of three steps which were initiated by the Friedel-Crafts acetylation of the indoles resulting in compounds 3.5 - 3.7. A bromination step followed which yielded the -bromo ketones (3.8 - 3.11). Some of the thiophenols (3.14 and 3.16) were not readily available in our laboratory and so were synthesized for the final synthetic step. This step involved the nucleophilic displacement of the -bromine to generate the -aryl substituted 3-indolylethanones (3.17 - 3.27). The thioethers displayed improved antimalarial activity from 2.24 and 2.25 against the chloroquine sensitive 3D7 Plasmodium falciparum strain. In addition, these compounds were non-toxic against HeLa cells which indicated this potential novel class of antimalarials is selective for the malaria parasite as hypothesized in the previous study conducted in our laboratory. In an attempt to predict the bioavailability of some of our compounds, in silico studies were conducted revealing that these compounds could be passively absorbed by the gastrointestinal tract, a positive result for bioavailability purposes. However, results from these studies indicate that modifications of these compounds would be necessary to allow for permeation through the blood brain barrier (BBB) for instances when the patient has cerebral malaria. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2018
- Full Text:
- Date Issued: 2018
Factors contributing to low supervision rate in Ugu District primary healthcare clinics
- Authors: Mkhize, Ntokozo Clarice
- Date: 2018
- Subjects: Mentoring in medicine http://id.loc.gov/authorities/subjects/sh98003695 , Mentoring in nursing http://id.loc.gov/authorities/subjects/sh92002828 , Public health personnel--Supervision of
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/19534 , vital:43136
- Description: Among the threats, barriers and challenges impeding access to health services in developing countries, Primary Healthcare Supervision was reported as a critical link with complex interventions that are implemented in different ways (Bosch-Capblanch & Garner, 2008:369). Among the objectives of the KwaZulu-Natal Department of Health Policy for PHC Supervision; are increasing the PHC Supervision rate from 60 percent to 85 percent; improvement of community participation and inter-sectoral collaboration to achieve improved health services in all health clinics in the Province of KwaZuluNatal (KZN Department of Health PHC Supervision Policy, 2010:9). However, currently there is no policy guiding the PHC Supervision processes in the province albeit an adapted policy document from the National Health Department and set of supervision tools are used to date. It is therefore critical to examine the strength and weaknesses of the current adapted guidelines for PHC Supervision processes including the reasons for the current low PHC Supervision rate in the province. , Thesis (MPH) -- University of Fort Hare, 2018
- Full Text:
- Date Issued: 2018
- Authors: Mkhize, Ntokozo Clarice
- Date: 2018
- Subjects: Mentoring in medicine http://id.loc.gov/authorities/subjects/sh98003695 , Mentoring in nursing http://id.loc.gov/authorities/subjects/sh92002828 , Public health personnel--Supervision of
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/19534 , vital:43136
- Description: Among the threats, barriers and challenges impeding access to health services in developing countries, Primary Healthcare Supervision was reported as a critical link with complex interventions that are implemented in different ways (Bosch-Capblanch & Garner, 2008:369). Among the objectives of the KwaZulu-Natal Department of Health Policy for PHC Supervision; are increasing the PHC Supervision rate from 60 percent to 85 percent; improvement of community participation and inter-sectoral collaboration to achieve improved health services in all health clinics in the Province of KwaZuluNatal (KZN Department of Health PHC Supervision Policy, 2010:9). However, currently there is no policy guiding the PHC Supervision processes in the province albeit an adapted policy document from the National Health Department and set of supervision tools are used to date. It is therefore critical to examine the strength and weaknesses of the current adapted guidelines for PHC Supervision processes including the reasons for the current low PHC Supervision rate in the province. , Thesis (MPH) -- University of Fort Hare, 2018
- Full Text:
- Date Issued: 2018
Import licensing regulation within the WTO: a case study of the dispute between Zimbabwe and South Africa over the Control of Goods (Open General Import Licence) Notice of 2016 (Statutory Instrument 64)
- Kamunjoma, Charles https://orcid.org/0000-0002-1930-4341
- Authors: Kamunjoma, Charles https://orcid.org/0000-0002-1930-4341
- Date: 2018
- Subjects: Import quotas , Customs unions , Africa, Southern -- Economic integration
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/27854 , vital:70097
- Description: Over the years, Zimbabwe has arbitrarily enforced trade restrictive measures including mandatory inspections on certain products, duty increases, surtaxes and import permits on basic products such as cooking oil. The measures have been allegedly targeting goods from South Africa. Amongst the most recent restrictive measures imposed by Zimbabwe is SI 64 of 2016 that now operates as SI 122 of 2017. In response to SI 64, for the first time, South Africa threatened retaliation. As a result, there is visible trade tension between Zimbabwe and South Africa. With the absence of an effective dispute settlement mechanism within SADC, or most African Regional Economic Communities RECs for that matter, a WTO approach to the issue will provide valuable insights on how else South Africa (and other African countries) can deal with cross-border trade problems such as the ones posed by SI 64. , Thesis (LLM) -- Faculty of Law, 2018
- Full Text:
- Date Issued: 2018
- Authors: Kamunjoma, Charles https://orcid.org/0000-0002-1930-4341
- Date: 2018
- Subjects: Import quotas , Customs unions , Africa, Southern -- Economic integration
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/27854 , vital:70097
- Description: Over the years, Zimbabwe has arbitrarily enforced trade restrictive measures including mandatory inspections on certain products, duty increases, surtaxes and import permits on basic products such as cooking oil. The measures have been allegedly targeting goods from South Africa. Amongst the most recent restrictive measures imposed by Zimbabwe is SI 64 of 2016 that now operates as SI 122 of 2017. In response to SI 64, for the first time, South Africa threatened retaliation. As a result, there is visible trade tension between Zimbabwe and South Africa. With the absence of an effective dispute settlement mechanism within SADC, or most African Regional Economic Communities RECs for that matter, a WTO approach to the issue will provide valuable insights on how else South Africa (and other African countries) can deal with cross-border trade problems such as the ones posed by SI 64. , Thesis (LLM) -- Faculty of Law, 2018
- Full Text:
- Date Issued: 2018
Production, purification, and characterisation of proteases from an ericoid mycorrhizal fungus, Oidiodendron maius
- Authors: Manyumwa, Colleen Varaidzo
- Date: 2018
- Subjects: Ascomycetes , Mycorrhizal fungi , Ericaceae , Proteolytic enzymes , Silver Recycling
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/62833 , vital:28298
- Description: The aim of this study was to produce, purify and characterise proteases from the ericoid mycorrhizal fungus, Oidiodendron maius (CafRU082b/KP119480), as well as to explore their potential application in the recovery of silver from X-ray film. Firstly, the growth of the ericoid mycorrhizal fungus, Oidiodendron maius (CafRU082b), was studied, and its ability to produce proteolytic enzymes was investigated. O. maius proved to grow well in the dark, submerged in Modified Melin Norkran’s liquid medium at a pH of 5 and at 25°C. Pure cultures of the fungus were maintained on Potato Dextrose Agar (PDA). The fungus grew on PDA plates containing different substrates including haemoglobin, casein, gelatin as well as azocasein. Zones of clearance, however, were only observed on plates containing gelatin after treatment with mercuric chloride, HgCl2. Proteases were successfully produced after 14 days when gelatin was incorporated into the growth medium. After production of the proteases, purification and characterisation of the enzymes was performed. Purification of the enzymes was performed by acetone precipitation followed by ultrafiltration with 50 kDa and 30 kDa cut off membrane filters. A final purification fold of approximately 37.6 was achieved. Unusual yields of above 100% were observed after each purification step with the final yield achieved being 196% with a final specific activity of 2707 U/mg. SDS-PAGE revealed a protease band of 35 kDa which was also visible on the zymogram at approximately 36 kDa. The zymogram showed clear hydrolysis bands against a blue background after staining with Coomassie Brilliant Blue. Physico-chemical characterisation of the protease revealed its pH optimum to be pH 3.0 and its temperature optimum 68°C. Another peak was observed on the pH profile at pH 7.0. The protease exhibited high thermostability at temperatures 37°C, 80°C as well as 100°C with the enzyme retaining close to 50% of its initial activity after 4 h of exposure to all three temperatures. All ions tested for their effects on the proteases, except Ca2+, enhanced protease activity. Ca2+ did not exhibit any significant effect on the enzyme’s activity while Zn2+ had the highest effect, enhancing enzyme activity by 305%. The proteases, however, were not significantly inhibited by EDTA, a metal chelating agent and a known metalloprotease inhibitor. The enzyme was classified as an aspartic protease due to complete inhibition by 25 μM of pepstatin A, coupled to its low pH optimum of 3.0. Addition of trans-Epoxysuccinyl-L-leucylamido-(4-guanidino)butane (E-64), a cysteine protease inhibitor, and 2-mercaptoethanol increased protease activity. The proteases exhibited a narrow substrate specificity towards gelatin and no other substrate. Substrate kinetics values were plotted on a Michaelis-Menten Graph and showed that the enzyme had a Vmax of 55.25 U/ml and a Km of 2.7 mg/ml gelatin. A low Km indicated that the protease had a high affinity for gelatin. Silver recovery studies from X-ray film revealed the proteases’ capability to remove silver from X-ray film, leaving the film intact. The recovery of silver was perceived visually, by film observation, as well as by scan electron microscopy (SEM) images, where clearance of the film was observed after incubation with the enzyme. Energy dispersive X-ray spectroscopy (EDS) profiles also confirmed removal of silver from the film, with a Ag peak showing on the profile of the film before treatment with the proteases and no peak after treatment. The crude protease sample was, however, catalytically more efficient compared to the partially purified sample. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2018
- Full Text:
- Date Issued: 2018
- Authors: Manyumwa, Colleen Varaidzo
- Date: 2018
- Subjects: Ascomycetes , Mycorrhizal fungi , Ericaceae , Proteolytic enzymes , Silver Recycling
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/62833 , vital:28298
- Description: The aim of this study was to produce, purify and characterise proteases from the ericoid mycorrhizal fungus, Oidiodendron maius (CafRU082b/KP119480), as well as to explore their potential application in the recovery of silver from X-ray film. Firstly, the growth of the ericoid mycorrhizal fungus, Oidiodendron maius (CafRU082b), was studied, and its ability to produce proteolytic enzymes was investigated. O. maius proved to grow well in the dark, submerged in Modified Melin Norkran’s liquid medium at a pH of 5 and at 25°C. Pure cultures of the fungus were maintained on Potato Dextrose Agar (PDA). The fungus grew on PDA plates containing different substrates including haemoglobin, casein, gelatin as well as azocasein. Zones of clearance, however, were only observed on plates containing gelatin after treatment with mercuric chloride, HgCl2. Proteases were successfully produced after 14 days when gelatin was incorporated into the growth medium. After production of the proteases, purification and characterisation of the enzymes was performed. Purification of the enzymes was performed by acetone precipitation followed by ultrafiltration with 50 kDa and 30 kDa cut off membrane filters. A final purification fold of approximately 37.6 was achieved. Unusual yields of above 100% were observed after each purification step with the final yield achieved being 196% with a final specific activity of 2707 U/mg. SDS-PAGE revealed a protease band of 35 kDa which was also visible on the zymogram at approximately 36 kDa. The zymogram showed clear hydrolysis bands against a blue background after staining with Coomassie Brilliant Blue. Physico-chemical characterisation of the protease revealed its pH optimum to be pH 3.0 and its temperature optimum 68°C. Another peak was observed on the pH profile at pH 7.0. The protease exhibited high thermostability at temperatures 37°C, 80°C as well as 100°C with the enzyme retaining close to 50% of its initial activity after 4 h of exposure to all three temperatures. All ions tested for their effects on the proteases, except Ca2+, enhanced protease activity. Ca2+ did not exhibit any significant effect on the enzyme’s activity while Zn2+ had the highest effect, enhancing enzyme activity by 305%. The proteases, however, were not significantly inhibited by EDTA, a metal chelating agent and a known metalloprotease inhibitor. The enzyme was classified as an aspartic protease due to complete inhibition by 25 μM of pepstatin A, coupled to its low pH optimum of 3.0. Addition of trans-Epoxysuccinyl-L-leucylamido-(4-guanidino)butane (E-64), a cysteine protease inhibitor, and 2-mercaptoethanol increased protease activity. The proteases exhibited a narrow substrate specificity towards gelatin and no other substrate. Substrate kinetics values were plotted on a Michaelis-Menten Graph and showed that the enzyme had a Vmax of 55.25 U/ml and a Km of 2.7 mg/ml gelatin. A low Km indicated that the protease had a high affinity for gelatin. Silver recovery studies from X-ray film revealed the proteases’ capability to remove silver from X-ray film, leaving the film intact. The recovery of silver was perceived visually, by film observation, as well as by scan electron microscopy (SEM) images, where clearance of the film was observed after incubation with the enzyme. Energy dispersive X-ray spectroscopy (EDS) profiles also confirmed removal of silver from the film, with a Ag peak showing on the profile of the film before treatment with the proteases and no peak after treatment. The crude protease sample was, however, catalytically more efficient compared to the partially purified sample. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2018
- Full Text:
- Date Issued: 2018
The effect of human resources management practices on employee commitment: the case of Mnquma Local Municipality
- Fihla, Siphenathi https://orcid.org/0000-0001-9632-2650
- Authors: Fihla, Siphenathi https://orcid.org/0000-0001-9632-2650
- Date: 2018
- Subjects: Personnel management--South Africa , Municipal government--South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/24431 , vital:62790
- Description: This study evaluated the relationship between the Human Resource Management Practices (HRMP) and employee commitment. Results based on a sample from Mnquma Local Municipality indicate that these practices have a significant impact on employee commitment. This project will help to advance research on exploring the influence of organisational variables on commitment. Research purpose: The purpose of the study was to investigate the effects of human resources management practices on employee commitment at Mnquma Local Municipality. Motivation for the study: The study examines HRMP and employee commitment in the public sector. The relationship between the two may be of value to the municipality’s success. Research approach, design and method: A quantitative research approach was followed to carry out this study. Data were collected from a sample of 137 respondents in a selected municipality (Mnquma Local Municipality). A self-administered questionnaire was sent to respondents. Main findings: A significant relationship was found between HRMP and employee commitment. Practical or managerial implications: Findings may be relevant to practitioners, including strategic management researchers, policy-makers, directors, managers, and supervisors. The study could assist various practitioners directly or indirectly involved in private and public organisations to develop HRMP that improves employee commitment. Contribution or value-add: The study adds to the literature on HRMP and employee commitment among the public service. , Thesis (MCom) -- Faculty of Management and Commerce, 2018
- Full Text:
- Date Issued: 2018
- Authors: Fihla, Siphenathi https://orcid.org/0000-0001-9632-2650
- Date: 2018
- Subjects: Personnel management--South Africa , Municipal government--South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/24431 , vital:62790
- Description: This study evaluated the relationship between the Human Resource Management Practices (HRMP) and employee commitment. Results based on a sample from Mnquma Local Municipality indicate that these practices have a significant impact on employee commitment. This project will help to advance research on exploring the influence of organisational variables on commitment. Research purpose: The purpose of the study was to investigate the effects of human resources management practices on employee commitment at Mnquma Local Municipality. Motivation for the study: The study examines HRMP and employee commitment in the public sector. The relationship between the two may be of value to the municipality’s success. Research approach, design and method: A quantitative research approach was followed to carry out this study. Data were collected from a sample of 137 respondents in a selected municipality (Mnquma Local Municipality). A self-administered questionnaire was sent to respondents. Main findings: A significant relationship was found between HRMP and employee commitment. Practical or managerial implications: Findings may be relevant to practitioners, including strategic management researchers, policy-makers, directors, managers, and supervisors. The study could assist various practitioners directly or indirectly involved in private and public organisations to develop HRMP that improves employee commitment. Contribution or value-add: The study adds to the literature on HRMP and employee commitment among the public service. , Thesis (MCom) -- Faculty of Management and Commerce, 2018
- Full Text:
- Date Issued: 2018
The role of ward committees in the local government sector: a case study of Enoch Mgijima local municipality of Eastern Cape (2012 – 2016)
- Authors: Mteyise, Nomapa Pretty
- Date: 2018
- Subjects: Public administration--Citizen participation. , Community development. , Public administration.
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22143 , vital:51987
- Description: Public participation is a vital aspect of developmental local government. A ward committee system was introduced in South Africa, as a channel for driving public participation programmes. This study set out to examine the experiences of ward committee members in Enoch Mgijima Local Municipality (EMLM). The aim was to assess the ward committee system as a vehicle for meaningful public participation in the integrated development planning processes. In 1995 the government formulated the White Paper on the Transformation of the Public Service. It indicated the importance of service delivery, and the aim was to transform the South African public service, as the key machinery of the government to equalize service delivery to all citizens. In 1996, the Constitution of the Republic of South Africa anchored the Bill of Rights as the cornerstone of democracy that enshrines the rights of all people and affirms the democratic values of human dignity, equality and freedom. The South African government has developed a wide array of legislation that ensures that communities are consulted on an unremitting basis with regard to how services need to be rendered. Communities have a right to be consulted and to give input into issues affecting them. Public consultation as envisaged in the South African legislation has, nevertheless, not yielded the desired results, which is evident in the spate of service delivery protests over poor or non-service delivery. Section 152(1) (e) of the Constitution promotes involvement of communities and community organisations in the matters of local government. Section 73 of the Municipal Structures Act (Act 117 of 1998) also requires municipalities to establish ward committees in a manner that seeks to enhance participatory democracy at the local level. This study set out to explore the experiences of ward committee members in EMLM. The intention was to evaluate the role of ward committees in the local government sector. , Thesis (MPA) -- University of Fort Hare, 2022
- Full Text:
- Date Issued: 2018
- Authors: Mteyise, Nomapa Pretty
- Date: 2018
- Subjects: Public administration--Citizen participation. , Community development. , Public administration.
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22143 , vital:51987
- Description: Public participation is a vital aspect of developmental local government. A ward committee system was introduced in South Africa, as a channel for driving public participation programmes. This study set out to examine the experiences of ward committee members in Enoch Mgijima Local Municipality (EMLM). The aim was to assess the ward committee system as a vehicle for meaningful public participation in the integrated development planning processes. In 1995 the government formulated the White Paper on the Transformation of the Public Service. It indicated the importance of service delivery, and the aim was to transform the South African public service, as the key machinery of the government to equalize service delivery to all citizens. In 1996, the Constitution of the Republic of South Africa anchored the Bill of Rights as the cornerstone of democracy that enshrines the rights of all people and affirms the democratic values of human dignity, equality and freedom. The South African government has developed a wide array of legislation that ensures that communities are consulted on an unremitting basis with regard to how services need to be rendered. Communities have a right to be consulted and to give input into issues affecting them. Public consultation as envisaged in the South African legislation has, nevertheless, not yielded the desired results, which is evident in the spate of service delivery protests over poor or non-service delivery. Section 152(1) (e) of the Constitution promotes involvement of communities and community organisations in the matters of local government. Section 73 of the Municipal Structures Act (Act 117 of 1998) also requires municipalities to establish ward committees in a manner that seeks to enhance participatory democracy at the local level. This study set out to explore the experiences of ward committee members in EMLM. The intention was to evaluate the role of ward committees in the local government sector. , Thesis (MPA) -- University of Fort Hare, 2022
- Full Text:
- Date Issued: 2018
Vachellia erioloba (camel thorn) and microbial interactions
- Authors: Van Aswegen, Sunet
- Date: 2018
- Subjects: Vesicular-arbuscular mycorrhizas , Cadmium , Rhizobacteria , Plant growth-promoting rhizobacteria , Acacia erioloba
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/63716 , vital:28475
- Description: Vachellia erioloba (camel thorn) is one of South Africa’s economically important tree species and therefore requires further investigation to improve its health and growth. Beneficial soil microbes have positive effects on plants through various mechanisms such as nitrogen fixation, phosphate solubilisation, indole acetic acid and siderophore production and biofilm formation. These traits enhance plant growth and protect the host plant against parasitic organisms that are present in soil. The arbuscular mycorrhizal (AM) fungi are well known for their beneficial symbiotic effects on host plants. The objective of this study was to determine the role of AM fungi and associated beneficial rhizobacteria in improving the growth of V. erioloba seedlings. Soil and root samples were collected from a farm in the Northern Cape, South Africa. Fifty-seven bacterial cultures were isolated from the soil and tested for plant growth promoting characteristics. Fourteen isolates showing at least four beneficial traits were molecularly identified using the GenBank database. The AM fungal and bacterial populations in the soil samples were assessed using Illumina sequencing. Sequences were identified using the MaarJAM and GenBank databases, respectively. Three separate pot trials were conducted to determine; 1) the effects of cadmium (Cd) on seedling growth; 2) the individual effects of three selected bacterial isolates and AM fungi alone and combined on seedling growth, and 3) the combined effects of the selected bacteria on AM fungal inoculated and uninoculated seedlings. Of the fourteen isolates the Enterobacter genera was the dominant species identified, with Acinetobacter, Pantoea and Bacillus each having one isolate. All were described as plant growth promoting rhizobacteria. One isolate from each genus, excluding Pantoea, was used in the pot trials. Three genera were identified in the AM fungal population that was assessed, namely Ambispora, Paraglomus and Glomus with Ambispora being the dominant genus. The bacterial population assessed showed a high diversity of bacteria from the Actinobacteria phylum being the dominant group. The results of the heavy metal pot trial showed that the symbiotic relationship between the seedlings and AM fungi increased the seedlings’ health and growth during heavy metal stress. The combination of bacteria and AM fungi increased growth parameters in all the inoculated seedlings, but not when compared to uninoculated seedlings indicating a possible competition for nutrients. The results were influenced by the presence of a nematode, which was suspected to have been seed borne. Further investigations on these interactions are required. Inoculation of AM fungi and selected PGPR is recommended for V. erioloba seedling production. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2018
- Full Text:
- Date Issued: 2018
- Authors: Van Aswegen, Sunet
- Date: 2018
- Subjects: Vesicular-arbuscular mycorrhizas , Cadmium , Rhizobacteria , Plant growth-promoting rhizobacteria , Acacia erioloba
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/63716 , vital:28475
- Description: Vachellia erioloba (camel thorn) is one of South Africa’s economically important tree species and therefore requires further investigation to improve its health and growth. Beneficial soil microbes have positive effects on plants through various mechanisms such as nitrogen fixation, phosphate solubilisation, indole acetic acid and siderophore production and biofilm formation. These traits enhance plant growth and protect the host plant against parasitic organisms that are present in soil. The arbuscular mycorrhizal (AM) fungi are well known for their beneficial symbiotic effects on host plants. The objective of this study was to determine the role of AM fungi and associated beneficial rhizobacteria in improving the growth of V. erioloba seedlings. Soil and root samples were collected from a farm in the Northern Cape, South Africa. Fifty-seven bacterial cultures were isolated from the soil and tested for plant growth promoting characteristics. Fourteen isolates showing at least four beneficial traits were molecularly identified using the GenBank database. The AM fungal and bacterial populations in the soil samples were assessed using Illumina sequencing. Sequences were identified using the MaarJAM and GenBank databases, respectively. Three separate pot trials were conducted to determine; 1) the effects of cadmium (Cd) on seedling growth; 2) the individual effects of three selected bacterial isolates and AM fungi alone and combined on seedling growth, and 3) the combined effects of the selected bacteria on AM fungal inoculated and uninoculated seedlings. Of the fourteen isolates the Enterobacter genera was the dominant species identified, with Acinetobacter, Pantoea and Bacillus each having one isolate. All were described as plant growth promoting rhizobacteria. One isolate from each genus, excluding Pantoea, was used in the pot trials. Three genera were identified in the AM fungal population that was assessed, namely Ambispora, Paraglomus and Glomus with Ambispora being the dominant genus. The bacterial population assessed showed a high diversity of bacteria from the Actinobacteria phylum being the dominant group. The results of the heavy metal pot trial showed that the symbiotic relationship between the seedlings and AM fungi increased the seedlings’ health and growth during heavy metal stress. The combination of bacteria and AM fungi increased growth parameters in all the inoculated seedlings, but not when compared to uninoculated seedlings indicating a possible competition for nutrients. The results were influenced by the presence of a nematode, which was suspected to have been seed borne. Further investigations on these interactions are required. Inoculation of AM fungi and selected PGPR is recommended for V. erioloba seedling production. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2018
- Full Text:
- Date Issued: 2018
Yeast-baculovirus synergism: investigating mixed infections for improved management of the false codling moth, Thaumatotibia leucotreta
- Authors: Van der Merwe, Marcel
- Date: 2018
- Subjects: Cryptophlebia leucotreta , Baculoviruses , Yeast , Citrus Diseases and pests , Biological pest control agents , Pests Integrated control
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/62963 , vital:28347
- Description: Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) or otherwise commonly known as the false codling moth is an indigenous pest of the citrus industry in southern Africa. The pest is highly significant as it impacts negatively on the export of fresh citrus fruits from South Africa to international markets. To control T. leucotreta in South Africa, an integrated pest management (IPM) programme has been implemented. One component of this programme is the baculovirus Cryptophlebia leucotreta granulovirus (CrleGV-SA) which has been formulated into the products Cryptogran™ and Cryptex®. It has previously been reported that there is a mutualistic association between Cydia pomonella (L.) (Lepidoptera: Tortricidae) also known as codling moth, and epiphytic yeasts. Cydia pomonella larval feeding galleries were colonised by yeasts and this, in turn, reduced larval mortality and enhanced larval development. It has been demonstrated in laboratory assays and field trials that combining yeast and brown cane sugar with Cydia pomonella granulovirus (CpGV) significantly increased larval mortality and lowered the proportion of injured apple fruit. This suggests that yeasts can enhance the effectiveness of an insect virus in managing pest larvae. In this study, we proposed to determine which species of yeast occur naturally in the digestive tract, frass and on the epidermis of T. leucotreta larvae and to examine whether any of these yeasts, when combined with the CrleGV-SA, have a synergistic effect in increasing mortality of T. leucotreta larvae. Firstly, Navel oranges infested with T. leucotreta larvae were collected from orchards in Sundays River Valley in Eastern Cape of South Africa. Larvae were extracted and analysed for the presence of yeast on their surface, or in their gut and frass. Four yeasts were isolated from T. leucotreta larvae and identified down to species level via PCR amplification and sequencing of internal transcribed spacer (ITS) region and D1/D2 domain of the large subunit (LSU) of rDNA region. These yeasts were isolated from the frass, epidermis and digestive tract of T. leucotreta larvae. The yeast isolates were identified as Meyerozyma caribbica, Pichia kluyveri, Pichia kudriavzevii and Hanseniaspora opuntiae. A yeast preference assay was conducted on female T. leucotreta moths to examine whether any of the isolated yeast species affected their oviposition preference. Navel oranges were inoculated with the isolated yeast species at a concentration of 6 × 108 cells.ml-1. The assay also included a Brewer’s yeast and distilled water control. Pichia kudriavzevii was shown to be the preferred yeast species for oviposition, as significantly more eggs were deposited on Navel oranges inoculated with this yeast compared to the other treatments. Lastly, a detached fruit bioassay was performed to evaluate the efficacy of mixing P. kudriavzevii with CrleGV-SA to enhance T. leucotreta larvae mortality. Pichia kudriavzevii was selected as it was demonstrated as having an effect on the oviposition preference of female T. leucotreta moths. The concentration at which P. kudriavzevii was applied remained the same as in the preference assay while CrleGV-SA was applied at lethal concentration required to kill 50 % of the population (9.31 × 107 OBs.ml-1). Although an increase in larval mortality was observed between CrleGV-SA being applied alone and the yeast/virus mixture, this result was determined not to be statistically significant. The experiments performed in this study provide a platform for further research into the application of a yeast-virus combination as a novel control option for T. leucotreta in the field. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2018
- Full Text:
- Date Issued: 2018
- Authors: Van der Merwe, Marcel
- Date: 2018
- Subjects: Cryptophlebia leucotreta , Baculoviruses , Yeast , Citrus Diseases and pests , Biological pest control agents , Pests Integrated control
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/62963 , vital:28347
- Description: Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) or otherwise commonly known as the false codling moth is an indigenous pest of the citrus industry in southern Africa. The pest is highly significant as it impacts negatively on the export of fresh citrus fruits from South Africa to international markets. To control T. leucotreta in South Africa, an integrated pest management (IPM) programme has been implemented. One component of this programme is the baculovirus Cryptophlebia leucotreta granulovirus (CrleGV-SA) which has been formulated into the products Cryptogran™ and Cryptex®. It has previously been reported that there is a mutualistic association between Cydia pomonella (L.) (Lepidoptera: Tortricidae) also known as codling moth, and epiphytic yeasts. Cydia pomonella larval feeding galleries were colonised by yeasts and this, in turn, reduced larval mortality and enhanced larval development. It has been demonstrated in laboratory assays and field trials that combining yeast and brown cane sugar with Cydia pomonella granulovirus (CpGV) significantly increased larval mortality and lowered the proportion of injured apple fruit. This suggests that yeasts can enhance the effectiveness of an insect virus in managing pest larvae. In this study, we proposed to determine which species of yeast occur naturally in the digestive tract, frass and on the epidermis of T. leucotreta larvae and to examine whether any of these yeasts, when combined with the CrleGV-SA, have a synergistic effect in increasing mortality of T. leucotreta larvae. Firstly, Navel oranges infested with T. leucotreta larvae were collected from orchards in Sundays River Valley in Eastern Cape of South Africa. Larvae were extracted and analysed for the presence of yeast on their surface, or in their gut and frass. Four yeasts were isolated from T. leucotreta larvae and identified down to species level via PCR amplification and sequencing of internal transcribed spacer (ITS) region and D1/D2 domain of the large subunit (LSU) of rDNA region. These yeasts were isolated from the frass, epidermis and digestive tract of T. leucotreta larvae. The yeast isolates were identified as Meyerozyma caribbica, Pichia kluyveri, Pichia kudriavzevii and Hanseniaspora opuntiae. A yeast preference assay was conducted on female T. leucotreta moths to examine whether any of the isolated yeast species affected their oviposition preference. Navel oranges were inoculated with the isolated yeast species at a concentration of 6 × 108 cells.ml-1. The assay also included a Brewer’s yeast and distilled water control. Pichia kudriavzevii was shown to be the preferred yeast species for oviposition, as significantly more eggs were deposited on Navel oranges inoculated with this yeast compared to the other treatments. Lastly, a detached fruit bioassay was performed to evaluate the efficacy of mixing P. kudriavzevii with CrleGV-SA to enhance T. leucotreta larvae mortality. Pichia kudriavzevii was selected as it was demonstrated as having an effect on the oviposition preference of female T. leucotreta moths. The concentration at which P. kudriavzevii was applied remained the same as in the preference assay while CrleGV-SA was applied at lethal concentration required to kill 50 % of the population (9.31 × 107 OBs.ml-1). Although an increase in larval mortality was observed between CrleGV-SA being applied alone and the yeast/virus mixture, this result was determined not to be statistically significant. The experiments performed in this study provide a platform for further research into the application of a yeast-virus combination as a novel control option for T. leucotreta in the field. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2018
- Full Text:
- Date Issued: 2018
Synthesis and characterization of titanium dioxide nanotubes on fluorine-doped tin oxide (FTO) glass substrate using electro-anodization technique
- Zinya, Simcelile https://orcid.org/0000-0001-5864-0957
- Authors: Zinya, Simcelile https://orcid.org/0000-0001-5864-0957
- Date: 2017-12
- Subjects: Titanium dioxide , Nanotubes , Nanostructured materials
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/23979 , vital:62201
- Description: One-dimensional (1-D) titanium dioxide nanotubes (TNTs) have attracted much attention as a promising alternative electrode material for dye sensitized solar cell (DSSC). As compared to the randomly packed and disordered TiO2 nanoparticles (TNPs) network with numerous particle-particle interfaces, TNTs prove to have fascinating features than make them suitable candidates in DSSCs. Well-structured TNTs arrays are of great potential among the various types of 1D TiO2 nano-materials owing to their superior electron transport properties with limited grain boundaries. Vectorial transport of photon generated electrons along the TNTs has been reported to lead to higher charge mobility which is crucial for improvement of DSSC performances. In this work, highly adhesive titanium films were deposited on functional substrates (FS) using radio frequency (RF) sputtering technique at a sputtering output power of 1kW, operating pressure of 1.5 Pa and at a deposition temperature of 200 °C to obtain a thickness of 10 μm under an inert argon atmosphere. The duration period for sputter coating 10 μm thickness of titanium film layer was 122 minutes with sputter rate for titanium target of about 82 nm per minutes. Subsequently, the RF sputtered titanium films were anodized with 0.5 wt. percent ammonium fluoride + 0.35 wt. percent deionised water and 96 wt. percent glycerol electrolyte solution at room temperature at 60 V for 72 hours. The resulting TNTs on functional substrates (TNTs-FS) were subjected to thermal treatment at 350 °C, 450 °C, 550 °C and 650 °C for 3 hours under oxygen atmosphere. The effect of annealing temperature on the morphological, and structural properties have been scrutinized. The as prepared and thermally treated TNTs-FS were characterized using scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and Confocal Raman Spectroscopy (CRS). SEM and HRTEM techniques were employed to confirm the presence of the TNTs-FS and also to study the structural-morphology of the TNTs as the annealing temperature increases. SEM revealed improvement in morphology with increase in sample annealing temperature, even at high temperatures such as 650 °C with no collapsing and sintering of the TNTs-FS occurring. SEM images revealed TNTs-FS with pore diameter sizes in the range between 85-170 nm. This is in compliance with HRTEM analysis, which revealed smooth and straight tube walls and improved surface morphology with increase in annealing temperature. In addition HRTEM images revealed pore diameter of TNTs-FS in the range between 85-165 nm. Furthermore, HRTEM revealed lattice fringes of 0.351, 0.352 and 0.353 nm between the neighbouring lattice fringes. All corresponding to (101) planes of anatase phase TNTs at different annealing temperatures (350-650 °C). The crystallographic structure of TNTs-FS was characterized by XRD measurements after thermal treatment at 350 °C, 450 °C, 550 °C and 650 °C. The XRD pattern revealed peaks in the wide angle range of 2θ (20° < 2θ > 80°) discovered at 29.43°, 45.10°, 56.52°, 63.5°, 64.92° and 74.81° corresponding to the planes (101), (112), (200), (105), (211) and (204) crystalline structures of the anatase TNTs. The intensity of the peaks increased with increasing annealing temperature. The strong sharp peaks indicate the large quantities and higher degrees of crystallinity of anatase phase of the TNTs. CRS Large Area Scan (LAS) and Depth profiling (DP) were employed to evaluate the crystallinity and phase distribution of TNTs-FS thermally treated at different temperatures. CRS LAS in the XY direction of TNTs-FS revealed the presence of differently crystallized anatase phases of TiO2 with Raman vibrational modes of 159.38 cm-1 (Eg), 208.37 cm-1 (Eg), 399.67 cm-1 (B1g), 514.25 cm-1 (A1g) and 641.58 cm-1 (Eg) for the samples annealed at 350 °C. The effect of annealing temperature on TiO2 phase evolution was meticulously evaluated using CRS for TNTs-FS for the samples annealed at 350 °C, 450 °C, 550 °C and 650 °C. The FWHM was estimated from CRS and decreases with increasing annealing temperature resulting in increasing crystallinity. Increase in anatase FWHM and anatase peak intensity implies higher degree of crystallinity and increasing crystallite sizes were also confirmed by XRD. Growing of titanium dioxide on functional substrates one novel contribution towards the fabrication of efficient electrode materials for solar cell development. Our method of characterizing TNTs-FS from a large area scan along the surface of the samples and depth profiling along the TNTs tube walls using confocal Raman spectroscopy prove to be a pivotal step in the development of efficient photoelectrode materials of the solar devices. , Thesis (MSc) -- Faculty of Science and Agriculture, 2017
- Full Text:
- Date Issued: 2017-12
- Authors: Zinya, Simcelile https://orcid.org/0000-0001-5864-0957
- Date: 2017-12
- Subjects: Titanium dioxide , Nanotubes , Nanostructured materials
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/23979 , vital:62201
- Description: One-dimensional (1-D) titanium dioxide nanotubes (TNTs) have attracted much attention as a promising alternative electrode material for dye sensitized solar cell (DSSC). As compared to the randomly packed and disordered TiO2 nanoparticles (TNPs) network with numerous particle-particle interfaces, TNTs prove to have fascinating features than make them suitable candidates in DSSCs. Well-structured TNTs arrays are of great potential among the various types of 1D TiO2 nano-materials owing to their superior electron transport properties with limited grain boundaries. Vectorial transport of photon generated electrons along the TNTs has been reported to lead to higher charge mobility which is crucial for improvement of DSSC performances. In this work, highly adhesive titanium films were deposited on functional substrates (FS) using radio frequency (RF) sputtering technique at a sputtering output power of 1kW, operating pressure of 1.5 Pa and at a deposition temperature of 200 °C to obtain a thickness of 10 μm under an inert argon atmosphere. The duration period for sputter coating 10 μm thickness of titanium film layer was 122 minutes with sputter rate for titanium target of about 82 nm per minutes. Subsequently, the RF sputtered titanium films were anodized with 0.5 wt. percent ammonium fluoride + 0.35 wt. percent deionised water and 96 wt. percent glycerol electrolyte solution at room temperature at 60 V for 72 hours. The resulting TNTs on functional substrates (TNTs-FS) were subjected to thermal treatment at 350 °C, 450 °C, 550 °C and 650 °C for 3 hours under oxygen atmosphere. The effect of annealing temperature on the morphological, and structural properties have been scrutinized. The as prepared and thermally treated TNTs-FS were characterized using scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and Confocal Raman Spectroscopy (CRS). SEM and HRTEM techniques were employed to confirm the presence of the TNTs-FS and also to study the structural-morphology of the TNTs as the annealing temperature increases. SEM revealed improvement in morphology with increase in sample annealing temperature, even at high temperatures such as 650 °C with no collapsing and sintering of the TNTs-FS occurring. SEM images revealed TNTs-FS with pore diameter sizes in the range between 85-170 nm. This is in compliance with HRTEM analysis, which revealed smooth and straight tube walls and improved surface morphology with increase in annealing temperature. In addition HRTEM images revealed pore diameter of TNTs-FS in the range between 85-165 nm. Furthermore, HRTEM revealed lattice fringes of 0.351, 0.352 and 0.353 nm between the neighbouring lattice fringes. All corresponding to (101) planes of anatase phase TNTs at different annealing temperatures (350-650 °C). The crystallographic structure of TNTs-FS was characterized by XRD measurements after thermal treatment at 350 °C, 450 °C, 550 °C and 650 °C. The XRD pattern revealed peaks in the wide angle range of 2θ (20° < 2θ > 80°) discovered at 29.43°, 45.10°, 56.52°, 63.5°, 64.92° and 74.81° corresponding to the planes (101), (112), (200), (105), (211) and (204) crystalline structures of the anatase TNTs. The intensity of the peaks increased with increasing annealing temperature. The strong sharp peaks indicate the large quantities and higher degrees of crystallinity of anatase phase of the TNTs. CRS Large Area Scan (LAS) and Depth profiling (DP) were employed to evaluate the crystallinity and phase distribution of TNTs-FS thermally treated at different temperatures. CRS LAS in the XY direction of TNTs-FS revealed the presence of differently crystallized anatase phases of TiO2 with Raman vibrational modes of 159.38 cm-1 (Eg), 208.37 cm-1 (Eg), 399.67 cm-1 (B1g), 514.25 cm-1 (A1g) and 641.58 cm-1 (Eg) for the samples annealed at 350 °C. The effect of annealing temperature on TiO2 phase evolution was meticulously evaluated using CRS for TNTs-FS for the samples annealed at 350 °C, 450 °C, 550 °C and 650 °C. The FWHM was estimated from CRS and decreases with increasing annealing temperature resulting in increasing crystallinity. Increase in anatase FWHM and anatase peak intensity implies higher degree of crystallinity and increasing crystallite sizes were also confirmed by XRD. Growing of titanium dioxide on functional substrates one novel contribution towards the fabrication of efficient electrode materials for solar cell development. Our method of characterizing TNTs-FS from a large area scan along the surface of the samples and depth profiling along the TNTs tube walls using confocal Raman spectroscopy prove to be a pivotal step in the development of efficient photoelectrode materials of the solar devices. , Thesis (MSc) -- Faculty of Science and Agriculture, 2017
- Full Text:
- Date Issued: 2017-12
Examining the reasons for the exclusion of pregnant learners from school through the school governing body pregnancy policy
- Bamidele, James Seidu https://orcid.org/0000-0001-6641-0385
- Authors: Bamidele, James Seidu https://orcid.org/0000-0001-6641-0385
- Date: 2017-07
- Subjects: School board members , Pregnant teenagers , Human rights
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22979 , vital:53375
- Description: Discrimination is a serious violation of human rights and it is strongly condemned by various legal instruments in South Africa. The South African Constitution (1996), Promotion of Administration Justice Act (2000) and Promotion of Equality and Prevention of Unfair Discrimination Act (2000) forbade discrimination and exclusion of pregnant learners from school. In spite of these legislative frameworks, School Governing Body (SGB) continues to exclude pregnant learners from school. SGB claimed that pregnant learners are harmful to other female learners and is becoming a significant barrier to girls’ education. Research shows that learners’ pregnancy is predominant in rural areas, apparently poses a threat to female education (Annual School Survey Report, 2010). The purpose of this dissertation is to establish that SGB lacks power to do so; however, their resistance to the law by excluding the pregnant learners from school is in conflict with the South African Constitution. This dissertation investigated an alternative instrument of legal remedy to reduce the problem of learners’ pregnancy rather than exclusion. The theoretical framework of this study is informed by Public Policy Theory (Ijeoma, 2010). Literatures and scholarly works on education law (Oosthuizen, 2015) and articles on Learners’ pregnancy shall be reviewed (Morell, Bhana & Shefer, 2012). The study followed qualitative research method which utilizes a transformative research paradigm that provides a collective voice for the participants. The data is collected through focused interview and open-ended questions, and subsequently analysed to establish that SGB lacks power to exclude a pregnant learner from school. Finally, the study reveals an alternative instrument of legal remedy to reduce the alarming number of pregnant learners rather than exclusion. , Thesis (MEd) -- Faculty of Education, 2017
- Full Text:
- Date Issued: 2017-07
- Authors: Bamidele, James Seidu https://orcid.org/0000-0001-6641-0385
- Date: 2017-07
- Subjects: School board members , Pregnant teenagers , Human rights
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22979 , vital:53375
- Description: Discrimination is a serious violation of human rights and it is strongly condemned by various legal instruments in South Africa. The South African Constitution (1996), Promotion of Administration Justice Act (2000) and Promotion of Equality and Prevention of Unfair Discrimination Act (2000) forbade discrimination and exclusion of pregnant learners from school. In spite of these legislative frameworks, School Governing Body (SGB) continues to exclude pregnant learners from school. SGB claimed that pregnant learners are harmful to other female learners and is becoming a significant barrier to girls’ education. Research shows that learners’ pregnancy is predominant in rural areas, apparently poses a threat to female education (Annual School Survey Report, 2010). The purpose of this dissertation is to establish that SGB lacks power to do so; however, their resistance to the law by excluding the pregnant learners from school is in conflict with the South African Constitution. This dissertation investigated an alternative instrument of legal remedy to reduce the problem of learners’ pregnancy rather than exclusion. The theoretical framework of this study is informed by Public Policy Theory (Ijeoma, 2010). Literatures and scholarly works on education law (Oosthuizen, 2015) and articles on Learners’ pregnancy shall be reviewed (Morell, Bhana & Shefer, 2012). The study followed qualitative research method which utilizes a transformative research paradigm that provides a collective voice for the participants. The data is collected through focused interview and open-ended questions, and subsequently analysed to establish that SGB lacks power to exclude a pregnant learner from school. Finally, the study reveals an alternative instrument of legal remedy to reduce the alarming number of pregnant learners rather than exclusion. , Thesis (MEd) -- Faculty of Education, 2017
- Full Text:
- Date Issued: 2017-07
An Investigation into the community's experience of the land claim process: the case study of Cwengcwe village in King Williams Town, Eastern Cape
- Authors: Mgweba, Unati Natashe
- Date: 2017
- Subjects: Land reform -- South Africa , Restitution , Black people -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/26808 , vital:66011
- Description: This study examines Cwengcwe community’s experiences of the land claim process. This community is located in King William’s Town, Eastern Cape. The land issue remains unfinished business in the South African context with many land claimants still waiting to receive their land back or to be compensated for their land with money. Cwengcwe community members are not an exception in the channel of claiming back their land and having to wait for a lengthy period of time to be compensated. The main objective of the study was therefore to find out about the experiences of the Cwengcwe community with regards to the land claims process. The study adopted a qualitative research approach and the data was collected by conducting semi-structured interviews and observations. Purposive sampling was used to collect data from community members at Cwengcwe village. The findings of the study reveal that the community members in this village are very disappointed at the slow progress of processing the land claims, as their claims which were lodged in 2015 had not been settled as yet in November 2017. Furthermore, the minimal and/or lack of communication from the Department of Rural Development and Land Reform was a negative indicator in the prioritisation ladder. This study recommends further exploration of the land claim process in order to review its model and come up with alternative processes that might ease the land claim process. , Thesis (MSoc) -- Faculty of Social Sciences and Humanities, 2017
- Full Text:
- Date Issued: 2017
- Authors: Mgweba, Unati Natashe
- Date: 2017
- Subjects: Land reform -- South Africa , Restitution , Black people -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/26808 , vital:66011
- Description: This study examines Cwengcwe community’s experiences of the land claim process. This community is located in King William’s Town, Eastern Cape. The land issue remains unfinished business in the South African context with many land claimants still waiting to receive their land back or to be compensated for their land with money. Cwengcwe community members are not an exception in the channel of claiming back their land and having to wait for a lengthy period of time to be compensated. The main objective of the study was therefore to find out about the experiences of the Cwengcwe community with regards to the land claims process. The study adopted a qualitative research approach and the data was collected by conducting semi-structured interviews and observations. Purposive sampling was used to collect data from community members at Cwengcwe village. The findings of the study reveal that the community members in this village are very disappointed at the slow progress of processing the land claims, as their claims which were lodged in 2015 had not been settled as yet in November 2017. Furthermore, the minimal and/or lack of communication from the Department of Rural Development and Land Reform was a negative indicator in the prioritisation ladder. This study recommends further exploration of the land claim process in order to review its model and come up with alternative processes that might ease the land claim process. , Thesis (MSoc) -- Faculty of Social Sciences and Humanities, 2017
- Full Text:
- Date Issued: 2017
Composition and fate of triclosan in the sludge from wastewater treatment in Grahamstown, South Africa and Tiaret, Algeria
- Authors: Ncube, Mbonisi
- Date: 2017
- Subjects: Sewage sludge , Sewage Purification South Africa Grahamstown , Sewage Purification Algeria Tiaret , Sewage sludge as fertilizer , Anti-infective agents
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/65156 , vital:28697
- Description: Physicochemical properties such as pH, specific surface area (SSA), cationic exchange capacity (CEC), loss on ignition (LOI), pathogens, plant nutrients (nitrates, ammonium and phosphates), and heavy metals (manganese, copper, lead and cadmium) were determined for sewage sludge from Grahamstown and Tiaret. The values obtained were log transformed thereafter a t-test at 5 % level of significance was used to test for the difference in each parameter for both sludges. The pH of sludge was determined in 1:3 water, 16 water, 1:3 0.01 M calcium chloride and 1:3 1 M potassium chloride. The pH for Grahamstown and Tiaret sludge were in the ranges of 6.66-7.11 and 7.88-8.18 respectively. The SSA values for Grahamstown and Tiaret were 218 ± 108 and 261 ± 99.9 m2/g, and the CEC values were 119 ± 2.09 and 136 ± 6.03 mEq/100, respectively. The LOI values obtained were 1.33 ± 0.03 and 1.48 ± 0.11 % for Grahamstown and Tiaret, respectively. E. coll and heterotrophic bacteria were the pathogens determined, and were extracted from sludge using sterile saline and nutrient broth. The concentration of E. coll in Grahamstown and Tiaret sludge were 468 ± 7.63 and 7769 ± 1268 CFU/g d.w and for heterotrophic bacteria were 1.17x109 ± 7.42x108 and 1.43x109 ± 9.11 x108 CFU/g d.w. For Grahamstown sludge, the concentration of nitrates, ammonium and phosphates were 55.61 ± 55.20 mg/g d.w, 6.60 ± 2.36 mg/g d.w and 1.40 ± 0.30 mg/g d.w, respectively. For Tiaret sludge, the concentration of nitrates, ammonium and phosphates were 2.56 ± 2.90 mg/g d.w, 0.64 ± 0.45 mg/g d.w and 0.24 ± 0.19 mg/g d.w, respectively. The concentration of Mn, Cu, Pb and Cd in Grahamstown sludge were 423 ± 101, 353 ± 92, 40.2 ± 20 and 0.0 mg/kg d.w respectively, and for Tiaret sludge, the corresponding concentrations were 358± 295, 549±50, 1427± 1352 and 1.54 ± 0.61 mg/kg d.w. Sewage sludge was found to contain Triclosan, and solubility studies of the compound were conducted using sodium deoxycholate and sodium lithocholate. The apparent solubilities and rate constants indicated in brackets of TCS at 37 °C were 35.4 ± 1.21 mg/L (1.28 ± 0.36 Hr-) and 14.4 ± 0.34 mg/L (0.99 ± 0.17 Hr-) in sodium lithocholate and sodium deoxycholate, respectively. The apparent solubilities and rate constants indicated in brackets of TCS at 15 °C were 32.3 ± 0.88 mg/L (2.16 ± 0.80 Hr-) and 14.2 ± 0.39 mg/L (1.02 ± 0.17 Hr-) in sodium lithocholate and sodium deoxycholate, respectively. Triclosan was extracted from sludge using 1 g/L sodium deoxycholate and the determined concentration were 142 ± 33.5 gg/g d.w for Grahamstown sludge and 0-12 gg/g d.w for Tiaret sludge. Finally plant growth studies were conducted on radish and garden cress plants using Grahamstown sludge at 0, 20, 40, 80 and 100 % treatments. Statistical analysis (t-test and Kruskal-Wallis) at 5 % level of significance was done to compare growth parameters between control and different sludge treatments. For radish plants, the values for plant height, root length, number of leaves, leaf length and dry mass were 28.4-80-7 mm, 4.3-44.7 mm, 3.3-17.0 mm, 2.3-4.0 leaves and 6.3-15.3 %, respectively. For garden cress, the values for plant height, root length, number of leaves, leaf length and dry mass were 13.7-25.0 mm, 7.7-20.3 mm, 5.7-8.3 leaves, 3.0-8.3 mm and 8.8-15.0 %, respectively. Twenty percent (20 %) sludge treatment gave the best results in radish and garden cress plants with respect to plant height, root length, number of leaves and dry mass. Triclosan concentration in radish and garden cress plants was below the detection limit of 32.4 gg/g d.w. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2017
- Full Text:
- Date Issued: 2017
- Authors: Ncube, Mbonisi
- Date: 2017
- Subjects: Sewage sludge , Sewage Purification South Africa Grahamstown , Sewage Purification Algeria Tiaret , Sewage sludge as fertilizer , Anti-infective agents
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/65156 , vital:28697
- Description: Physicochemical properties such as pH, specific surface area (SSA), cationic exchange capacity (CEC), loss on ignition (LOI), pathogens, plant nutrients (nitrates, ammonium and phosphates), and heavy metals (manganese, copper, lead and cadmium) were determined for sewage sludge from Grahamstown and Tiaret. The values obtained were log transformed thereafter a t-test at 5 % level of significance was used to test for the difference in each parameter for both sludges. The pH of sludge was determined in 1:3 water, 16 water, 1:3 0.01 M calcium chloride and 1:3 1 M potassium chloride. The pH for Grahamstown and Tiaret sludge were in the ranges of 6.66-7.11 and 7.88-8.18 respectively. The SSA values for Grahamstown and Tiaret were 218 ± 108 and 261 ± 99.9 m2/g, and the CEC values were 119 ± 2.09 and 136 ± 6.03 mEq/100, respectively. The LOI values obtained were 1.33 ± 0.03 and 1.48 ± 0.11 % for Grahamstown and Tiaret, respectively. E. coll and heterotrophic bacteria were the pathogens determined, and were extracted from sludge using sterile saline and nutrient broth. The concentration of E. coll in Grahamstown and Tiaret sludge were 468 ± 7.63 and 7769 ± 1268 CFU/g d.w and for heterotrophic bacteria were 1.17x109 ± 7.42x108 and 1.43x109 ± 9.11 x108 CFU/g d.w. For Grahamstown sludge, the concentration of nitrates, ammonium and phosphates were 55.61 ± 55.20 mg/g d.w, 6.60 ± 2.36 mg/g d.w and 1.40 ± 0.30 mg/g d.w, respectively. For Tiaret sludge, the concentration of nitrates, ammonium and phosphates were 2.56 ± 2.90 mg/g d.w, 0.64 ± 0.45 mg/g d.w and 0.24 ± 0.19 mg/g d.w, respectively. The concentration of Mn, Cu, Pb and Cd in Grahamstown sludge were 423 ± 101, 353 ± 92, 40.2 ± 20 and 0.0 mg/kg d.w respectively, and for Tiaret sludge, the corresponding concentrations were 358± 295, 549±50, 1427± 1352 and 1.54 ± 0.61 mg/kg d.w. Sewage sludge was found to contain Triclosan, and solubility studies of the compound were conducted using sodium deoxycholate and sodium lithocholate. The apparent solubilities and rate constants indicated in brackets of TCS at 37 °C were 35.4 ± 1.21 mg/L (1.28 ± 0.36 Hr-) and 14.4 ± 0.34 mg/L (0.99 ± 0.17 Hr-) in sodium lithocholate and sodium deoxycholate, respectively. The apparent solubilities and rate constants indicated in brackets of TCS at 15 °C were 32.3 ± 0.88 mg/L (2.16 ± 0.80 Hr-) and 14.2 ± 0.39 mg/L (1.02 ± 0.17 Hr-) in sodium lithocholate and sodium deoxycholate, respectively. Triclosan was extracted from sludge using 1 g/L sodium deoxycholate and the determined concentration were 142 ± 33.5 gg/g d.w for Grahamstown sludge and 0-12 gg/g d.w for Tiaret sludge. Finally plant growth studies were conducted on radish and garden cress plants using Grahamstown sludge at 0, 20, 40, 80 and 100 % treatments. Statistical analysis (t-test and Kruskal-Wallis) at 5 % level of significance was done to compare growth parameters between control and different sludge treatments. For radish plants, the values for plant height, root length, number of leaves, leaf length and dry mass were 28.4-80-7 mm, 4.3-44.7 mm, 3.3-17.0 mm, 2.3-4.0 leaves and 6.3-15.3 %, respectively. For garden cress, the values for plant height, root length, number of leaves, leaf length and dry mass were 13.7-25.0 mm, 7.7-20.3 mm, 5.7-8.3 leaves, 3.0-8.3 mm and 8.8-15.0 %, respectively. Twenty percent (20 %) sludge treatment gave the best results in radish and garden cress plants with respect to plant height, root length, number of leaves and dry mass. Triclosan concentration in radish and garden cress plants was below the detection limit of 32.4 gg/g d.w. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2017
- Full Text:
- Date Issued: 2017
Development and assessment of gastric-retentive sustained release metronidazole microcapsules
- Authors: Makan, Anjana
- Date: 2017
- Subjects: Metronidazole , Drug delivery systems , Helicobacter pylori , High performance liquid chromatography , Gas chromatography , Drugs , Drugs Controlled release
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/59240 , vital:27491
- Description: Helicobacter pylori is one of the most common pathogenic bacterial infections and is the leading cause of gastritis, gastroduodenal ulcer disease and gastric cancers. Studies have revealed the prevalence of Helicobacter pylori is high in many countries around the globe. Although Helicobacter pylori is highly sensitive to antimicrobial agents in vitro the clinical eradication rate of the disease is still low. The instability of API at gastric pH, low concentration of API in the gastric mucosa and short gastric residence times are the main reasons for poor eradication rates. The high prevalence rate of this disease necessitates the design and development of gastric-retentive site specific oral dosage forms for the optimized delivery of existing therapeutic molecules and may be an approach to improving the eradication rate of Helicobacter pylori. Metronidazole (MTZ) is a 5-nitroimidazole derivative that exhibits antibiotic and antiprotozoal activity. MTZ is used in combination with other compounds for the treatment of Helicobacter pylori in peptic ulcer disease. MTZ is a potential candidate for inclusion in a sustained release gastric-retentive delivery system that acts in the stomach and since it is unstable in the intestinal/colonic environment enhancing gastric residence time would be a therapeutic advantage. MTZ is a cost-effective therapy that exhibits good anti-microbial activity and has a favourable pharmacokinetic profile. A sustained release gastric-retentive formulation is therefore proposed as an approach to enhance the local delivery of MTZ and improve treatment outcomes for patients infected with Helicobacter pylori. A stability indicating Reversed-Phase High Performance Liquid Chromatography (RP- HPLC) method for the quantitation of MTZ in pharmaceutical dosage forms was developed and optimised using a Central Composite Design (CCD) approach. The RP-HPLC method was found to be linear, accurate, precise, sensitive, selective, and was applied to the analysis of MTZ in commercially available medicines. Preformulation studies were conducted as preparative work prior to manufacture gastric- retentive sustained release MTZ microcapsules. The experiments conducted were tailored for the development of sustained release MTZ microcapsules using a solvent evaporation method. The particle size and shape of the microcapsules was investigated using Scanning Electron Microscopy (SEM). MTZ- excipient compatibility studies were performed using Fourier Transform Infra-red Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and X-Ray Diffraction (XRD). The results revealed that no definite interaction between MTZ and intended excipients to be used for manufacture of MTZ formulations occurred. A solvent evaporation procedure was used for the manufacture of MTZ microcapsules. Preliminary formulations were manufactured using two different grades of Methocel® at various levels. In addition the impact of processing parameters on performance was also investigated. The formulations were assessed in terms of in vitro release, buoyancy, yield, encapsulation efficiency and microcapsule size. Formulation optimisation was undertaken using a CCD approach and numerical optimisation was used to predict an optimised formulation composition that would produce minimal initial MTZ release, maximum MTZ release at 12 hours and maximum buoyancy, encapsulation efficiency and yield. The kinetics of MTZ release from microcapsules was established by fitting in vitro release data to different mathematical models. Higuchi model and first-order model appeared to best fit the data as majority of the formulation batches had highest R2 values for these models. Short-term stability assessment of the optimised formulation was established by undertaking stability studies at 25°C/60% RH and 40°C/75%RH. No significant changes in any of the CQA were observed over 30 days of stability testing. A gas chromatographic (GC) method was developed and validated for the quantitation of residual acetone and n-hexane. The optimised formulation contained 213.60 ppm/g acetone and 25.23 ppm/g n-hexane which are well below the limits set for residual solvents. In conclusion, gastric-retentive sustained release MTZ microcapsules with potential for further development and optimisation have been successfully developed and assessed in these studies. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2017
- Full Text:
- Date Issued: 2017
- Authors: Makan, Anjana
- Date: 2017
- Subjects: Metronidazole , Drug delivery systems , Helicobacter pylori , High performance liquid chromatography , Gas chromatography , Drugs , Drugs Controlled release
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/59240 , vital:27491
- Description: Helicobacter pylori is one of the most common pathogenic bacterial infections and is the leading cause of gastritis, gastroduodenal ulcer disease and gastric cancers. Studies have revealed the prevalence of Helicobacter pylori is high in many countries around the globe. Although Helicobacter pylori is highly sensitive to antimicrobial agents in vitro the clinical eradication rate of the disease is still low. The instability of API at gastric pH, low concentration of API in the gastric mucosa and short gastric residence times are the main reasons for poor eradication rates. The high prevalence rate of this disease necessitates the design and development of gastric-retentive site specific oral dosage forms for the optimized delivery of existing therapeutic molecules and may be an approach to improving the eradication rate of Helicobacter pylori. Metronidazole (MTZ) is a 5-nitroimidazole derivative that exhibits antibiotic and antiprotozoal activity. MTZ is used in combination with other compounds for the treatment of Helicobacter pylori in peptic ulcer disease. MTZ is a potential candidate for inclusion in a sustained release gastric-retentive delivery system that acts in the stomach and since it is unstable in the intestinal/colonic environment enhancing gastric residence time would be a therapeutic advantage. MTZ is a cost-effective therapy that exhibits good anti-microbial activity and has a favourable pharmacokinetic profile. A sustained release gastric-retentive formulation is therefore proposed as an approach to enhance the local delivery of MTZ and improve treatment outcomes for patients infected with Helicobacter pylori. A stability indicating Reversed-Phase High Performance Liquid Chromatography (RP- HPLC) method for the quantitation of MTZ in pharmaceutical dosage forms was developed and optimised using a Central Composite Design (CCD) approach. The RP-HPLC method was found to be linear, accurate, precise, sensitive, selective, and was applied to the analysis of MTZ in commercially available medicines. Preformulation studies were conducted as preparative work prior to manufacture gastric- retentive sustained release MTZ microcapsules. The experiments conducted were tailored for the development of sustained release MTZ microcapsules using a solvent evaporation method. The particle size and shape of the microcapsules was investigated using Scanning Electron Microscopy (SEM). MTZ- excipient compatibility studies were performed using Fourier Transform Infra-red Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and X-Ray Diffraction (XRD). The results revealed that no definite interaction between MTZ and intended excipients to be used for manufacture of MTZ formulations occurred. A solvent evaporation procedure was used for the manufacture of MTZ microcapsules. Preliminary formulations were manufactured using two different grades of Methocel® at various levels. In addition the impact of processing parameters on performance was also investigated. The formulations were assessed in terms of in vitro release, buoyancy, yield, encapsulation efficiency and microcapsule size. Formulation optimisation was undertaken using a CCD approach and numerical optimisation was used to predict an optimised formulation composition that would produce minimal initial MTZ release, maximum MTZ release at 12 hours and maximum buoyancy, encapsulation efficiency and yield. The kinetics of MTZ release from microcapsules was established by fitting in vitro release data to different mathematical models. Higuchi model and first-order model appeared to best fit the data as majority of the formulation batches had highest R2 values for these models. Short-term stability assessment of the optimised formulation was established by undertaking stability studies at 25°C/60% RH and 40°C/75%RH. No significant changes in any of the CQA were observed over 30 days of stability testing. A gas chromatographic (GC) method was developed and validated for the quantitation of residual acetone and n-hexane. The optimised formulation contained 213.60 ppm/g acetone and 25.23 ppm/g n-hexane which are well below the limits set for residual solvents. In conclusion, gastric-retentive sustained release MTZ microcapsules with potential for further development and optimisation have been successfully developed and assessed in these studies. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2017
- Full Text:
- Date Issued: 2017
Evaluating the potential of monometallic and bimetallic nanomaterials as horseradish peroxidase mimetics
- Authors: Mvango, Sindisiwe
- Date: 2017
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/65134 , vital:28694
- Description: This study presents the synthesis of citrate-capped gold nanoparticles (cit-AuNPs), copper oxide nanoparticles (CuONPs), glutathione-capped gold nanoparticles (GSH-AuNPs), 4- aminothiophenol-capped gold nanoparticles (4-ATP-AuNPs), 4-mercapto benzoic acid- capped gold nanoparticles (4-MBA-AuNPs) and copper oxide gold nanoalloys (CuO-Au nanoalloys). Microscopy and spectroscopy techniques were used to confirm the successful synthesis of these nanoparticles. The synthesized nanoparticles were studied their potential applications as horseradish peroxidase (HPR) enzyme mimetics and for the detection of glucose. The cit-AuNPs and GSH-AuNPs exhibited peroxidase-like activity towards hydrogen peroxide (H2O2) with high Michaelis-Menten (Km) values of 61.5 mM and 30.8 mM, respectively. The other nanoparticles, that is, 4-ATP-AuNPs, CuONPs and CuO-Au nanoalloys gave lower Km values of 4.74 mM, 1.92 mM and 4.05 mM, respectively. The obtained Km values were comparable to those of HRP enzymes which ranged from 0.214 - 3.70 mM with 4-ATP-AuNPs and CuO-Au nanoalloys slightly higher. These values were within the reasonable experimental values of the HRP enzyme. The studies showed that the gold nanoparticles had low adsorptive efficiency towards H2O2 compared to the copper-based nanoparticles (CuONPs and CuO-Au nanoalloys). The CuO-Au nanoalloys also showed the synergistic effect between the gold and copper nanoparticles with extended linear concentration range for the quantification of H2O2. The mechanism of catalysis was confirmed using UV-vis spectroscopy and electron paramagnetic resonance (EPR) in that the generation of reactive oxygen species was observed. The use of 1,3-diphenylisobenzofuran (DPBF) as radical quencher and 5,5- dimethyl-1-pyrroline N-oxide (DMPO) as a radical scavenger confirmed the production of reductive reactive oxygen species using UV-vis and EPR studies. The rate of production of reactive oxygen species in the gold-based nanoparticles was small compared to the copper-based nanoparticles, that is CuONPs and CuO-Au (bimetallic) nanoalloys. The synthesized nanoparticles were further studied their potential use in the colorimetric detection of glucose. The copper-based nanomaterials, CuONPs and CuO-Au nanoalloys, were excellent towards detection of glucose, with a limit of detection (LoD) of 9.34 pM for CuONPs and 6.75 pM for CuO-Au nanoalloys. The linear concentration (LCR) range of CuONPs was 0 to 70 pM and for CuO-Au nanoalloys the LCR was 0.0 - 30 pM. , Thesis (MSc) -- Faculty of Science, Chemistry, 2017
- Full Text:
- Date Issued: 2017
- Authors: Mvango, Sindisiwe
- Date: 2017
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/65134 , vital:28694
- Description: This study presents the synthesis of citrate-capped gold nanoparticles (cit-AuNPs), copper oxide nanoparticles (CuONPs), glutathione-capped gold nanoparticles (GSH-AuNPs), 4- aminothiophenol-capped gold nanoparticles (4-ATP-AuNPs), 4-mercapto benzoic acid- capped gold nanoparticles (4-MBA-AuNPs) and copper oxide gold nanoalloys (CuO-Au nanoalloys). Microscopy and spectroscopy techniques were used to confirm the successful synthesis of these nanoparticles. The synthesized nanoparticles were studied their potential applications as horseradish peroxidase (HPR) enzyme mimetics and for the detection of glucose. The cit-AuNPs and GSH-AuNPs exhibited peroxidase-like activity towards hydrogen peroxide (H2O2) with high Michaelis-Menten (Km) values of 61.5 mM and 30.8 mM, respectively. The other nanoparticles, that is, 4-ATP-AuNPs, CuONPs and CuO-Au nanoalloys gave lower Km values of 4.74 mM, 1.92 mM and 4.05 mM, respectively. The obtained Km values were comparable to those of HRP enzymes which ranged from 0.214 - 3.70 mM with 4-ATP-AuNPs and CuO-Au nanoalloys slightly higher. These values were within the reasonable experimental values of the HRP enzyme. The studies showed that the gold nanoparticles had low adsorptive efficiency towards H2O2 compared to the copper-based nanoparticles (CuONPs and CuO-Au nanoalloys). The CuO-Au nanoalloys also showed the synergistic effect between the gold and copper nanoparticles with extended linear concentration range for the quantification of H2O2. The mechanism of catalysis was confirmed using UV-vis spectroscopy and electron paramagnetic resonance (EPR) in that the generation of reactive oxygen species was observed. The use of 1,3-diphenylisobenzofuran (DPBF) as radical quencher and 5,5- dimethyl-1-pyrroline N-oxide (DMPO) as a radical scavenger confirmed the production of reductive reactive oxygen species using UV-vis and EPR studies. The rate of production of reactive oxygen species in the gold-based nanoparticles was small compared to the copper-based nanoparticles, that is CuONPs and CuO-Au (bimetallic) nanoalloys. The synthesized nanoparticles were further studied their potential use in the colorimetric detection of glucose. The copper-based nanomaterials, CuONPs and CuO-Au nanoalloys, were excellent towards detection of glucose, with a limit of detection (LoD) of 9.34 pM for CuONPs and 6.75 pM for CuO-Au nanoalloys. The linear concentration (LCR) range of CuONPs was 0 to 70 pM and for CuO-Au nanoalloys the LCR was 0.0 - 30 pM. , Thesis (MSc) -- Faculty of Science, Chemistry, 2017
- Full Text:
- Date Issued: 2017
Formulation development, manufacture and evaluation of hydralazine hydrochloride microspheres
- Kangausaru, Shakemore Tinashe
- Authors: Kangausaru, Shakemore Tinashe
- Date: 2017
- Subjects: Hydralazine , Microspheres , Drugs Controlled release , Drugs Design , Drug development , Hypertension Chemotherapy
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/59220 , vital:27482
- Description: Despite improvements in its detection and treatment since the 1970s, hypertension is the most common and important risk factor for cardiovascular diseases. Hypertension is a chronic condition often underdiagnosed and/or inadequately treated in Sub-Saharan Africa. Recent survey results illustrate that the condition continues to contribute significantly to mortality and morbidity in adults and that it is poorly controlled in clinical practice. Hydralazine (HYD) is used either alone or in combination for the management of chronic hypertension, chronic cardiac failure and hypertensive crises. Due to its short plasma half-life of between 2 to 4 hours, HYD is normally administered two to four times daily, therefore making it a potential candidate for inclusion in sustained release formulations. The formulation of sustained release microsphere dosage forms may be useful to improve patient adherence and to achieve predictable and optimised therapeutic plasma concentrations. A stability indicating reversed-phase high performance liquid chromatography (RP-HPLC) method for the quantitation of HYD in pharmaceutical dosage forms was developed and optimised using a Central Composite Design (CCD) approach. UV/Vis detection method was selected as HYD contains an ultraviolet light-absorbing chromophore. The method was validated with respect to linearity and range, limits of quantitation (LOQ) and detection (LOD), accuracy, precision, sensitivity, selectivity and specificity as per International Conference on Harmonisation (ICH) guidelines. The method was applied to commercially available HYD tablets. No interfering peaks were observed from excipients used in the commercially available tablets. Preformulation studies were conducted to ensure the manufacture of high quality, stable sustained release HYD microspheres. The results revealed that there was an interaction between HYD and Carbopol® 971P, therefore Carbopol® polymers were not included during formulation studies. HYD was found to be compatible with Methocel® K100LV, Eudragit® RS PO and Avicel® 101 and HYD formulations were developed and optimised using these excipients. An oil-in-oil (o/o) solvent evaporation technique was selected for the manufacture of HYD microspheres due to its simplicity and to avoid exposure of HYD to moisture that could have been encountered if a water-in-oil (w/o) manufacturing process was used. The selection of o/o solvent evaporation technique was also based on the hydrophilicity of HYD and the polymers selected. Different grades of Methocel® and Eudragit® were selected to evaluate their effect on encapsulation efficiency (EE), in vitro release and microparticle shape and morphology. The best combination of these polymers which resulted in the desired EE, in vitro release, microparticle shape and size were then selected for formulation optimisation. A numerical optimisation approach was used to predict a formulation composition that would produce minimal HYD release initially and maximum HYD release after 12 hours of dissolution testing. The release kinetics of HYD from the manufactured microspheres were established by fitting in vitro release data to several mathematical models. The in vitro release data for the optimised formulations was best described using Higuchi model. The short-term stability of the optimised formulations was established by undertaking stability studies at 4°C, 25 °C/60 % RH and 40 °C/75 % RH. The results revealed that there was no significant change in appearance and physicochemical properties of the microspheres over a period of one month. However, long-term stability studies would be required to determine the shelf-life of the formulations. In addition, a gas chromatographic (GC) method was selected for determining residual amounts of acetone and n-hexane in the optimised formulations. GC methods were developed and optimised by evaluation of process parameters. System suitability testing was performed with respect to resolution, theoretical number of plates and selectivity. Method validation was performed with respect to linearity, range, inter- and intra-day precision, retention time (Rt) precision, limit of quantitation (LOQ) and detection (LOD). A solvent extraction method was used to analyse residual solvents in the optimised formulations. The drying process was sufficient in evaporating acetone and n-hexane from the optimised formulations. Solvent evaporation technique has been successfully used in the manufacture of HYD microspheres. The microspheres have potential for further development, scale up formulation studies and long-term stability studies. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2017
- Full Text:
- Date Issued: 2017
- Authors: Kangausaru, Shakemore Tinashe
- Date: 2017
- Subjects: Hydralazine , Microspheres , Drugs Controlled release , Drugs Design , Drug development , Hypertension Chemotherapy
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/59220 , vital:27482
- Description: Despite improvements in its detection and treatment since the 1970s, hypertension is the most common and important risk factor for cardiovascular diseases. Hypertension is a chronic condition often underdiagnosed and/or inadequately treated in Sub-Saharan Africa. Recent survey results illustrate that the condition continues to contribute significantly to mortality and morbidity in adults and that it is poorly controlled in clinical practice. Hydralazine (HYD) is used either alone or in combination for the management of chronic hypertension, chronic cardiac failure and hypertensive crises. Due to its short plasma half-life of between 2 to 4 hours, HYD is normally administered two to four times daily, therefore making it a potential candidate for inclusion in sustained release formulations. The formulation of sustained release microsphere dosage forms may be useful to improve patient adherence and to achieve predictable and optimised therapeutic plasma concentrations. A stability indicating reversed-phase high performance liquid chromatography (RP-HPLC) method for the quantitation of HYD in pharmaceutical dosage forms was developed and optimised using a Central Composite Design (CCD) approach. UV/Vis detection method was selected as HYD contains an ultraviolet light-absorbing chromophore. The method was validated with respect to linearity and range, limits of quantitation (LOQ) and detection (LOD), accuracy, precision, sensitivity, selectivity and specificity as per International Conference on Harmonisation (ICH) guidelines. The method was applied to commercially available HYD tablets. No interfering peaks were observed from excipients used in the commercially available tablets. Preformulation studies were conducted to ensure the manufacture of high quality, stable sustained release HYD microspheres. The results revealed that there was an interaction between HYD and Carbopol® 971P, therefore Carbopol® polymers were not included during formulation studies. HYD was found to be compatible with Methocel® K100LV, Eudragit® RS PO and Avicel® 101 and HYD formulations were developed and optimised using these excipients. An oil-in-oil (o/o) solvent evaporation technique was selected for the manufacture of HYD microspheres due to its simplicity and to avoid exposure of HYD to moisture that could have been encountered if a water-in-oil (w/o) manufacturing process was used. The selection of o/o solvent evaporation technique was also based on the hydrophilicity of HYD and the polymers selected. Different grades of Methocel® and Eudragit® were selected to evaluate their effect on encapsulation efficiency (EE), in vitro release and microparticle shape and morphology. The best combination of these polymers which resulted in the desired EE, in vitro release, microparticle shape and size were then selected for formulation optimisation. A numerical optimisation approach was used to predict a formulation composition that would produce minimal HYD release initially and maximum HYD release after 12 hours of dissolution testing. The release kinetics of HYD from the manufactured microspheres were established by fitting in vitro release data to several mathematical models. The in vitro release data for the optimised formulations was best described using Higuchi model. The short-term stability of the optimised formulations was established by undertaking stability studies at 4°C, 25 °C/60 % RH and 40 °C/75 % RH. The results revealed that there was no significant change in appearance and physicochemical properties of the microspheres over a period of one month. However, long-term stability studies would be required to determine the shelf-life of the formulations. In addition, a gas chromatographic (GC) method was selected for determining residual amounts of acetone and n-hexane in the optimised formulations. GC methods were developed and optimised by evaluation of process parameters. System suitability testing was performed with respect to resolution, theoretical number of plates and selectivity. Method validation was performed with respect to linearity, range, inter- and intra-day precision, retention time (Rt) precision, limit of quantitation (LOQ) and detection (LOD). A solvent extraction method was used to analyse residual solvents in the optimised formulations. The drying process was sufficient in evaporating acetone and n-hexane from the optimised formulations. Solvent evaporation technique has been successfully used in the manufacture of HYD microspheres. The microspheres have potential for further development, scale up formulation studies and long-term stability studies. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2017
- Full Text:
- Date Issued: 2017
Geological study and economic evaluation of the Paardeplaats Coal Exploration Project
- Authors: Gcayi, Gcobani
- Date: 2017
- Subjects: Coal Geology South Africa Mpumalanga , Coal Prospecting South Africa Mpumalanga , Coal mines and mining South Africa Mpumalanga , Geology, Economic South Africa , Coal reserves South Africa Mpumalanga
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/59183 , vital:27452
- Description: For a coal mining company the coal resources are an important asset, and they are acquired in a number of different ways, such as obtaining a prospecting permit from government or an existing permit from another entity and or purchasing an operating colliery from another entity. The Paardeplaats Project is a brownfields project located approximately 7 km south west of the town of Belfast in Mpumalanga Province, South Africa, on the far eastern edge of the Witbank Coalfield. The project is located adjacent to an operating mine, Glisa Colliery, owned by Eyesizwe Coal. Eyesizwe Coal was awarded the prospecting permit in 2006 by the Department of Mineral Resources. Subsequent exploration activities, which included airborne magnetic survey and borehole drilling, were conducted between 2008 and 2010. The results of the drilling confirmed the presence of coal resources, which are classified in the Measured, Indicated and Inferred categories. Mining and beneficiation methods from the adjacent Glisa Colliery, which has similar geology to the project area, were assumed in order to generate a coal reserve statement. The Coal Reserve qualities are suitable to the domestic market, particularly Eskom. South Africa’s coal supply is demand driven, primarily from Eskom for electricity generation followed by the export market and thirdly by Sasol for synthetic fuel generation. The majority of Eskom’s existing coal-fired power stations are located in the Mpumalanga Province, which provides a viable market for coal projects in Mpumalanga when considering existing transport infrastructure and transportation costs. Eskom’s continued demand for coal in the Mpumalanga region, at least until 2040, provides a future market for advanced coal projects in the region. A valuation of the project using the Cash Flow Approach showed the project to be economically viable. , Thesis (MSc) -- Faculty of Faculty of Science, Geology, 2017
- Full Text:
- Date Issued: 2017
- Authors: Gcayi, Gcobani
- Date: 2017
- Subjects: Coal Geology South Africa Mpumalanga , Coal Prospecting South Africa Mpumalanga , Coal mines and mining South Africa Mpumalanga , Geology, Economic South Africa , Coal reserves South Africa Mpumalanga
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/59183 , vital:27452
- Description: For a coal mining company the coal resources are an important asset, and they are acquired in a number of different ways, such as obtaining a prospecting permit from government or an existing permit from another entity and or purchasing an operating colliery from another entity. The Paardeplaats Project is a brownfields project located approximately 7 km south west of the town of Belfast in Mpumalanga Province, South Africa, on the far eastern edge of the Witbank Coalfield. The project is located adjacent to an operating mine, Glisa Colliery, owned by Eyesizwe Coal. Eyesizwe Coal was awarded the prospecting permit in 2006 by the Department of Mineral Resources. Subsequent exploration activities, which included airborne magnetic survey and borehole drilling, were conducted between 2008 and 2010. The results of the drilling confirmed the presence of coal resources, which are classified in the Measured, Indicated and Inferred categories. Mining and beneficiation methods from the adjacent Glisa Colliery, which has similar geology to the project area, were assumed in order to generate a coal reserve statement. The Coal Reserve qualities are suitable to the domestic market, particularly Eskom. South Africa’s coal supply is demand driven, primarily from Eskom for electricity generation followed by the export market and thirdly by Sasol for synthetic fuel generation. The majority of Eskom’s existing coal-fired power stations are located in the Mpumalanga Province, which provides a viable market for coal projects in Mpumalanga when considering existing transport infrastructure and transportation costs. Eskom’s continued demand for coal in the Mpumalanga region, at least until 2040, provides a future market for advanced coal projects in the region. A valuation of the project using the Cash Flow Approach showed the project to be economically viable. , Thesis (MSc) -- Faculty of Faculty of Science, Geology, 2017
- Full Text:
- Date Issued: 2017
Investigating the expression of three small open reading frames encoded on Helicoverpa armigera stunt virus RNA 1
- Authors: De Bruyn, Mart-Mari
- Date: 2017
- Subjects: Helicoverpa armigera , RNA viruses , Insects Viruses , Proteins
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/59168 , vital:27448
- Description: The Helicoverpa armigera stunt virus (HaSV), belonging to the Family Alphatetraviridae (Genus: Omegatetravirus), is a non-enveloped insect virus encapsidating a bi-partite, positive-sense single-stranded RNA genome. RNA1 encodes the replicase, as well as three small open reading frames (ORFs) arranged in tandem, and overlapping with the 3’ end of the replicase ORF. These ORFs, designated p11, p15 and p8, encode putative proteins of unknown function. The p11 and p15 ORFs are conserved in the genome of the related Omegatetravirus, Dendrolimus punctatus tetravirus. In HaSV, the stop codon of p11 is followed immediately by the start of p15, whereas the stop of p15 and start of p8 are separated by a glycine intercodon. Furthermore, only p11 is known to have a recognizable Kozak sequence. The aim of this study was to determine the expression and function of these three small proteins in the HaSV infectious lifecycle. The authenticity of the viral cDNA sequence, encoding the three small ORFs, was validated by sequencing multiple cDNA clones of the relevant region in viral RNA (vRNA), purified from infectious HaSV particles. The sequence of all three ORFs was conserved in seven cDNA clones, while point mutations were observed in each of two remaining cDNA clones, suggesting that the ORFs were conserved in infectious virus. Polyclonal antisera were raised against a p11 peptide, and a recombinant p15-p8 fusion protein (p23) expressed and purified from Escherichia coli. The affinity of the anti-p23 antiserum was confirmed by western blot analysis, while that of the anti-p11 antiserum was confirmed using immunofluorescence microscopy, as attempted expression of recombinant p11 in E. coli appeared to be toxic. The antisera were used to detect expression of the small proteins in HaSV-infected H. armigera larvae by western blot analysis. A band migrating at approximately 34 kDa was detected by both antisera in infected larvae, absent in uninfected larvae, suggesting the expression of a p11-p15-p8 polyprotein. Protein bands of 11 kDa and 8 kDa were also detected by the anti-p11 and anti-p23 antisera, respectively. Bioinformatic analysis revealed that the polyprotein would be produced by a novel type of stop codon read-through, however the mechanism required for individual expression could not be definitively determined. The mechanism by which these ORFs are translated was further investigated by expressing p11-p15, tagged with FLAG and enhanced green flourescent protein (EGFP) at its amino- and carboxyl-termini respectively (FLAG-p11-p15-EGFP), in Spodoptera frugiperda (Sf9) cells detected by flourescence microscopy. Punctate structures were observed throughout the cytoplasm that were also detected with antiFLAG, anti-p11 and anti-p23 antisera, complementing results obtained in previous studies. Since p15 does not exhibit a strong recognizable Kozak like p11, the dependency of p15 expression on that of p11 was investigated by mutating this construct such that p15 occurred in a +1 frame to p11. Both EGFP and anti-p23 fluorescence was detected with the same cytoplasmic distribution as the unmutated construct, whereas nothing was detected by anti-FLAG and anti-p11. Preliminary results therefore suggested p15 may also be expressed as a discrete protein, independent of p11. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2018
- Full Text:
- Date Issued: 2017
- Authors: De Bruyn, Mart-Mari
- Date: 2017
- Subjects: Helicoverpa armigera , RNA viruses , Insects Viruses , Proteins
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/59168 , vital:27448
- Description: The Helicoverpa armigera stunt virus (HaSV), belonging to the Family Alphatetraviridae (Genus: Omegatetravirus), is a non-enveloped insect virus encapsidating a bi-partite, positive-sense single-stranded RNA genome. RNA1 encodes the replicase, as well as three small open reading frames (ORFs) arranged in tandem, and overlapping with the 3’ end of the replicase ORF. These ORFs, designated p11, p15 and p8, encode putative proteins of unknown function. The p11 and p15 ORFs are conserved in the genome of the related Omegatetravirus, Dendrolimus punctatus tetravirus. In HaSV, the stop codon of p11 is followed immediately by the start of p15, whereas the stop of p15 and start of p8 are separated by a glycine intercodon. Furthermore, only p11 is known to have a recognizable Kozak sequence. The aim of this study was to determine the expression and function of these three small proteins in the HaSV infectious lifecycle. The authenticity of the viral cDNA sequence, encoding the three small ORFs, was validated by sequencing multiple cDNA clones of the relevant region in viral RNA (vRNA), purified from infectious HaSV particles. The sequence of all three ORFs was conserved in seven cDNA clones, while point mutations were observed in each of two remaining cDNA clones, suggesting that the ORFs were conserved in infectious virus. Polyclonal antisera were raised against a p11 peptide, and a recombinant p15-p8 fusion protein (p23) expressed and purified from Escherichia coli. The affinity of the anti-p23 antiserum was confirmed by western blot analysis, while that of the anti-p11 antiserum was confirmed using immunofluorescence microscopy, as attempted expression of recombinant p11 in E. coli appeared to be toxic. The antisera were used to detect expression of the small proteins in HaSV-infected H. armigera larvae by western blot analysis. A band migrating at approximately 34 kDa was detected by both antisera in infected larvae, absent in uninfected larvae, suggesting the expression of a p11-p15-p8 polyprotein. Protein bands of 11 kDa and 8 kDa were also detected by the anti-p11 and anti-p23 antisera, respectively. Bioinformatic analysis revealed that the polyprotein would be produced by a novel type of stop codon read-through, however the mechanism required for individual expression could not be definitively determined. The mechanism by which these ORFs are translated was further investigated by expressing p11-p15, tagged with FLAG and enhanced green flourescent protein (EGFP) at its amino- and carboxyl-termini respectively (FLAG-p11-p15-EGFP), in Spodoptera frugiperda (Sf9) cells detected by flourescence microscopy. Punctate structures were observed throughout the cytoplasm that were also detected with antiFLAG, anti-p11 and anti-p23 antisera, complementing results obtained in previous studies. Since p15 does not exhibit a strong recognizable Kozak like p11, the dependency of p15 expression on that of p11 was investigated by mutating this construct such that p15 occurred in a +1 frame to p11. Both EGFP and anti-p23 fluorescence was detected with the same cytoplasmic distribution as the unmutated construct, whereas nothing was detected by anti-FLAG and anti-p11. Preliminary results therefore suggested p15 may also be expressed as a discrete protein, independent of p11. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2018
- Full Text:
- Date Issued: 2017
Investigation on the nature of records management in the office of the Premier Supply Chain management
- Authors: Vakalisa, Ndileka
- Date: 2017
- Subjects: Grahamstown (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/27606 , vital:69319
- Description: The purpose of the study was to investigate on the nature of records management in the office of the Premier Supply Chain Management. This study focuses on the Supply Chain Unit in the office of the Premier in the Eastern Cape Province of South Africa. The study sought to investigate the classification systems in place that is records management policy, procedure manual and file plans. The legal framework that regulates archives. Data was collected using open-ended questionnaire. The target population of this study included all the officials within the Office of the Premier. The sample of 15 was derived from the supply chain management officials, records management managers and directors. The study adopted a qualitative research methodology, which is multimethod in its orientation, which involves an interpretative, naturalistic emphasis to its subject issue. Findings from the study revealed that the unit had its internal records management policy, an official framework document that outlined the processes involved in organising records within the department. Thus, there are policy frameworks within the department even though not clearly described to other employees, which might lead to risks in the management of records. The study also revealed that most records personnel were not trained to effectively manage records. It was also indicated that there is a lack of proper filing system and or electronic records management system. Hence, for effective and efficient records management, the study recommends the creation of a web-based integrated system for communication and where records can be accessed within one system. The study also recommends proper training of records personnel to mitigate risks. Hence, the study recommends that senior management create and implement a records management program that clearly outlines the procedures of records management, risks factors and how to minimize them. This will aide in good practice, uniformity, standardization, high levels of professionalism, accountability, and transparency. , Thesis (MLIS) -- Faculty of Social Sciences and Humanities, 2017
- Full Text:
- Date Issued: 2017
- Authors: Vakalisa, Ndileka
- Date: 2017
- Subjects: Grahamstown (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/27606 , vital:69319
- Description: The purpose of the study was to investigate on the nature of records management in the office of the Premier Supply Chain Management. This study focuses on the Supply Chain Unit in the office of the Premier in the Eastern Cape Province of South Africa. The study sought to investigate the classification systems in place that is records management policy, procedure manual and file plans. The legal framework that regulates archives. Data was collected using open-ended questionnaire. The target population of this study included all the officials within the Office of the Premier. The sample of 15 was derived from the supply chain management officials, records management managers and directors. The study adopted a qualitative research methodology, which is multimethod in its orientation, which involves an interpretative, naturalistic emphasis to its subject issue. Findings from the study revealed that the unit had its internal records management policy, an official framework document that outlined the processes involved in organising records within the department. Thus, there are policy frameworks within the department even though not clearly described to other employees, which might lead to risks in the management of records. The study also revealed that most records personnel were not trained to effectively manage records. It was also indicated that there is a lack of proper filing system and or electronic records management system. Hence, for effective and efficient records management, the study recommends the creation of a web-based integrated system for communication and where records can be accessed within one system. The study also recommends proper training of records personnel to mitigate risks. Hence, the study recommends that senior management create and implement a records management program that clearly outlines the procedures of records management, risks factors and how to minimize them. This will aide in good practice, uniformity, standardization, high levels of professionalism, accountability, and transparency. , Thesis (MLIS) -- Faculty of Social Sciences and Humanities, 2017
- Full Text:
- Date Issued: 2017