Bioprospecting for entomopathogenic fungi against a foliar citrus pest
- Authors: Boon, Erin Ashley
- Date: 2025-04-02
- Subjects: Citrus Diseases and pests South Africa , Entomopathogenic fungi , Pests Integrated control , Biological assay , Cryptophlebia leucotreta , Ultraviolet radiation Physiological effect
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/478991 , vital:78247
- Description: Historically, pest management was highly dependent on the use of chemical insecticides for the control of agriculturally important pests. However, more recently, key export markets have imposed stringent chemical residue restrictions for citrus export. This deterring factor for chemical use has been coupled with the fact that these economically important pests are experiencing insecticidal resistance. As a result, the use of entomopathogenic fungi (EPF) has been explored as a complementary control option in integrated pest management (IPM) regimes. Previous research in South Africa identified several strains of Beauveria bassiana and Metarhizium spp. (including isolate M. pinghaense FCM Ar 23 B3). Laboratory bioassays evaluating the virulence of these isolates against major pests such as the false codling moth (FCM) (Thaumatotibia leucotreta, Lepidoptera: Tortricidae), citrus thrips (Scirtothrips aurantii, Thysanoptera: Thripidae), and citrus mealybugs (Planococcus citri, Hemiptera: Pseudococcidae) highlighted the potential of these EPF. While field trials targeting FCM with soil-applied treatments yielded encouraging results, foliar applications aimed at controlling citrus thrips and mealybugs showed limited success. These findings highlighted the need to assess the biological traits of the recovered isolates. Varying temperature ranges and humidity levels were found to not hinder the isolates' efficacy in the field. Conidial inactivation induced by ultraviolet (UV) radiation however, was. As these strains were recovered from the soil environment, it stood to reason that EPF isolates recovered from the foliar environment may be more suited for foliar application. Thus, bioprospecting for isolates from the aboveground environment was initiated and was the focal point of this thesis. Following the isolation and identification, the pathogenic ability and virulence, as well as the UV tolerance of these novel strains were established. Of the isolates recovered from the aboveground environment and identified using morphological and molecular techniques, four were B. bassiana (Px LM 4, Ha LM 11, Ha LM 12, Coe 18), one M. anisopliae (Hu LM 14), one Fusarium oxysporum (Pc HV 9), and one Geotrichum candidum yeast (Ha LM 2). The majority were isolated from insect cadavers, but one (Coe 18) was isolated as a foliar endophyte from an organically managed citrus farm in the Eastern Cape. Using standard protocols and conidial doses, the virulence of the recovered isolates was established against a common foliar pest of citrus, citrus mealybug. Isolate FCM Ar 23 B3 was included as a comparative control in this study as the virulence against citrus mealybug has previously been established. The initial screening of the isolates ranged between 15 and 90 % mortality. Isolates Px LM 4 and FCM Ar 23 B3 both induced an average mortality of 90 %. Isolates Ha LM 11, Ha LM 12, Hu LM 14, and Coe 18 caused mortalities greater than 60 % and were further investigated under dose-response assays. Of the six isolates measured for LC50, FCM Ar 23 B3 was the most virulent (5.25 × 105 conidia/ml), followed by Px LM 4 (1.09 × 106 conidia/ml) and Hu LM 14 (1.32 × 106 conidia/ml). The UV susceptibility to simulated sunlight of the six most virulent isolates was investigated. Whilst UV radiation certainly delayed the conidial germination of all the isolates, all the strains isolated from the aboveground environment demonstrated significant initial tolerance to UV radiation compared to the most virulent M. pinghaense FCM Ar 23 B3, which was recovered from the soil environment. Even though the B. bassiana Coe 18, which was recovered as an endophytic EPF, was not the most virulent, it stood out with strong initial UV tolerance and sustained a relatively high germination rate over time, establishing it as the most UV-tolerant isolate. Although formulation for development as a microbial biocontrol programme should not be overlooked for these isolates, the initial UV and sustained tolerance demonstrated by these aboveground isolates warrants further investigation under field conditions. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2025
- Full Text:
- Authors: Boon, Erin Ashley
- Date: 2025-04-02
- Subjects: Citrus Diseases and pests South Africa , Entomopathogenic fungi , Pests Integrated control , Biological assay , Cryptophlebia leucotreta , Ultraviolet radiation Physiological effect
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/478991 , vital:78247
- Description: Historically, pest management was highly dependent on the use of chemical insecticides for the control of agriculturally important pests. However, more recently, key export markets have imposed stringent chemical residue restrictions for citrus export. This deterring factor for chemical use has been coupled with the fact that these economically important pests are experiencing insecticidal resistance. As a result, the use of entomopathogenic fungi (EPF) has been explored as a complementary control option in integrated pest management (IPM) regimes. Previous research in South Africa identified several strains of Beauveria bassiana and Metarhizium spp. (including isolate M. pinghaense FCM Ar 23 B3). Laboratory bioassays evaluating the virulence of these isolates against major pests such as the false codling moth (FCM) (Thaumatotibia leucotreta, Lepidoptera: Tortricidae), citrus thrips (Scirtothrips aurantii, Thysanoptera: Thripidae), and citrus mealybugs (Planococcus citri, Hemiptera: Pseudococcidae) highlighted the potential of these EPF. While field trials targeting FCM with soil-applied treatments yielded encouraging results, foliar applications aimed at controlling citrus thrips and mealybugs showed limited success. These findings highlighted the need to assess the biological traits of the recovered isolates. Varying temperature ranges and humidity levels were found to not hinder the isolates' efficacy in the field. Conidial inactivation induced by ultraviolet (UV) radiation however, was. As these strains were recovered from the soil environment, it stood to reason that EPF isolates recovered from the foliar environment may be more suited for foliar application. Thus, bioprospecting for isolates from the aboveground environment was initiated and was the focal point of this thesis. Following the isolation and identification, the pathogenic ability and virulence, as well as the UV tolerance of these novel strains were established. Of the isolates recovered from the aboveground environment and identified using morphological and molecular techniques, four were B. bassiana (Px LM 4, Ha LM 11, Ha LM 12, Coe 18), one M. anisopliae (Hu LM 14), one Fusarium oxysporum (Pc HV 9), and one Geotrichum candidum yeast (Ha LM 2). The majority were isolated from insect cadavers, but one (Coe 18) was isolated as a foliar endophyte from an organically managed citrus farm in the Eastern Cape. Using standard protocols and conidial doses, the virulence of the recovered isolates was established against a common foliar pest of citrus, citrus mealybug. Isolate FCM Ar 23 B3 was included as a comparative control in this study as the virulence against citrus mealybug has previously been established. The initial screening of the isolates ranged between 15 and 90 % mortality. Isolates Px LM 4 and FCM Ar 23 B3 both induced an average mortality of 90 %. Isolates Ha LM 11, Ha LM 12, Hu LM 14, and Coe 18 caused mortalities greater than 60 % and were further investigated under dose-response assays. Of the six isolates measured for LC50, FCM Ar 23 B3 was the most virulent (5.25 × 105 conidia/ml), followed by Px LM 4 (1.09 × 106 conidia/ml) and Hu LM 14 (1.32 × 106 conidia/ml). The UV susceptibility to simulated sunlight of the six most virulent isolates was investigated. Whilst UV radiation certainly delayed the conidial germination of all the isolates, all the strains isolated from the aboveground environment demonstrated significant initial tolerance to UV radiation compared to the most virulent M. pinghaense FCM Ar 23 B3, which was recovered from the soil environment. Even though the B. bassiana Coe 18, which was recovered as an endophytic EPF, was not the most virulent, it stood out with strong initial UV tolerance and sustained a relatively high germination rate over time, establishing it as the most UV-tolerant isolate. Although formulation for development as a microbial biocontrol programme should not be overlooked for these isolates, the initial UV and sustained tolerance demonstrated by these aboveground isolates warrants further investigation under field conditions. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2025
- Full Text:
Do the Cytochrome P450 1A2 allele variations have an effect on the structure and function of the protein?
- Authors: Mondile, Queenie
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/463907 , vital:76456
- Description: Access restricted. Expected release in 2025. , Thesis (MSc) -- Faculty of Science, Biochemistry, Microbiology & Bioinformatics, 2024
- Full Text:
- Authors: Mondile, Queenie
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/463907 , vital:76456
- Description: Access restricted. Expected release in 2025. , Thesis (MSc) -- Faculty of Science, Biochemistry, Microbiology & Bioinformatics, 2024
- Full Text:
Exploring food waste narratives and perceptions in print media and in the urban community of Makhanda, in the Eastern Cape, South Africa
- Authors: Dlamini, Zinhle Nkululeko
- Date: 2024-10-11
- Subjects: Food waste South Africa Makhanda , Agenda-setting theory , Sociocultural system , Makhanda (South Africa) Social conditions , Mass media and public opinion South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464798 , vital:76546
- Description: Food waste (FW) is a global issue that has gained increasing attention in recent decades. There has been more research to identify the multi-layered causes and effects of this issue. A vast number of studies focus on the quantification of FW, its drivers, and causes. While quantifying the amount of FW being generated is important in revealing the scope of the problem, there are many aspects of FW that are still not as widely covered i.e., the socio-cultural component of FW. This is because first and foremost what is considered food, and what is considered FW is influenced by the sociocultural context in which it is obtained, prepared, and consumed. The socio-cultural context of a society cannot be studied properly without looking at the way the people that practice those specific societal norms and cultural practices think and perceive things. Perceptions are important because sociocultural behaviours and practices tend to be reproduced in correlation to how they are perceived. Thus, if the socio-cultural dimension of FW is to be dissected, one needs to look at the socialisation agents that affect the cultural context. A socialisation agent that has been cited as growing in influence and enjoying unprecedented access in human society is the media. Despite the proven influence of the media on perceptions and behavioural patterns, the sheer volume of studies that look at the linkages between media and topics such as FW is limited. in the context of the Global South, particularly in South Africa. In response to this research gap, I set out to examine the types of narratives and perceptions that print media and media consumers within an urban community have about FW. Since the study is centred around print media perceptions and narratives and those of the community, the study used a mixed-method approach that comprised of a media analysis, one-onone, semi structured interviews, key informant discussions as well as food focus groups. Thirty six respondents were interviewed with semi-structured one on one interviews, a further six respondents were key informants, they too were interviewed with one on one semi-structured interviews. Lastly, 16 were participants in the focus sessions, and each session comprised of 8 randomly selected participants. To procure the FW perceptions and narratives of print media and the people of Makhanda, the study was divided into three phases. Phase one comprised of a print media analysis through an archival media platform of SABINET. Phase two comprised of two food focus group sessions; phase three of the study comprised of the semi-structured interviews with 36 interviewees representing the general public and six with key informants. To make sense of the results obtained from the print media analysis, the study used the agenda setting framework and found that that the representation of FW content in print media was limited. Through the use of thematic analysis, 14 viii FW perceptions and narratives were identified in print media (and perceptions and narratives are used interchangeably, therefore 14 themes equals 14 FW perceptions and narratives). Of these 14 themes there were some that were more frequently presented than others. The most frequently presented perceptions and narratives in print media were the FW and food insecurity/hunger, FW and morality and FW and the economy. The study also found that a bulk of the FW content disseminated by print media belonged to a relatively few publications namely: Cape Argus, The Star, the Mail and Gurdian and the Daily Dispatch. These findings reinforced that FW perceptions and narratives in print media were not only disproportionally represented but were also disseminated by a limited pool of media content creators. The study found that Makhanda respondents used and preferred other media forms outside of print media i.e., radio and television. Respondents maintained that the media form they were the least exposed to and least preferred was print media (newspapers). From the 58 respondents, only seven respondents indicated that they listened to and preferred radio more than any other media form, and only two respondents noted that they read newspapers. In contrast, 24 respondents noted that they preferred and were more exposed to television than any other media form. In addition, respondents noted that they saw and heard a limited amount of FW content on the media that they were most exposed to. Instead, they noted that they were more exposed to content that encouraged them to procure and consume food, such as food advertisements. On average, individuals that were exposed to and preferred radio reported to hearing more FW content as opposed to individuals that preferred television. For instance, from the seven respondents that preferred and were most exposed to radio, four of them noted that they had heard a lot of FW content. While 17 of the 24 respondents that preferred and were most exposed to television, maintained that they did not recall seeing any FW content. The study also found that Makhanda respondents had a number of perceptions and narratives about FW, that were converted into themes using content and thematic analysis. The study found that Makhanda respondents had a total of 15 FW perceptions and narratives. Just like in the media analysis there were some perceptions and narratives that were emphasised and more frequently mentioned than others. The three most dominant themes were: affluence, FW and hunger, and FW and morality. Furthermore, the research also found that the perceptions and narratives of respondents were influenced by a variety of external and internal factors such as socio-economic status/affluence, gender, age, race, and media preference. These factors interacted with each other and varied in their significance from one respondent to the other. By far, the aspect shown to be the most influential in shaping respondents FW perceptions and narratives was affluence. Twentyeight respondents spoke about the economic drawbacks of FW and cited as reason for not engaging viii in FW. In addition to this, there were some respondents that maintained that FW did not occur amongst people who belonged to the lower socio-economic class and that rather, the phenomena were limited to those who were more affluent. In speaking about affluence, respondents e linked FW with other aspects such as race, gender, age, and media preference. For instance, in addition to claiming that FW was only limited to affluent households, other respondents felt that wasting food was a luxury the only white people participated in. Such claims highlight the idea that the sociocultural historical context of South Africa is one that has some influence in the FW perceptions and narratives of Makhanda respondents. The study found that there was little overlap in the types of perceptions and narratives that print media and the Makhanda respondents have about FW. From the 14 and 15 perceptions and narratives found between each realm there were only three thematic overlaps namely: the theme of affluence, morality and FW and food insecurity. This limited overlap of perceptions and narratives suggest that there is a disconnection present between the perceptions and narratives of print media and those that are exhibited by Makhanda respondents. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2024
- Full Text:
- Authors: Dlamini, Zinhle Nkululeko
- Date: 2024-10-11
- Subjects: Food waste South Africa Makhanda , Agenda-setting theory , Sociocultural system , Makhanda (South Africa) Social conditions , Mass media and public opinion South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464798 , vital:76546
- Description: Food waste (FW) is a global issue that has gained increasing attention in recent decades. There has been more research to identify the multi-layered causes and effects of this issue. A vast number of studies focus on the quantification of FW, its drivers, and causes. While quantifying the amount of FW being generated is important in revealing the scope of the problem, there are many aspects of FW that are still not as widely covered i.e., the socio-cultural component of FW. This is because first and foremost what is considered food, and what is considered FW is influenced by the sociocultural context in which it is obtained, prepared, and consumed. The socio-cultural context of a society cannot be studied properly without looking at the way the people that practice those specific societal norms and cultural practices think and perceive things. Perceptions are important because sociocultural behaviours and practices tend to be reproduced in correlation to how they are perceived. Thus, if the socio-cultural dimension of FW is to be dissected, one needs to look at the socialisation agents that affect the cultural context. A socialisation agent that has been cited as growing in influence and enjoying unprecedented access in human society is the media. Despite the proven influence of the media on perceptions and behavioural patterns, the sheer volume of studies that look at the linkages between media and topics such as FW is limited. in the context of the Global South, particularly in South Africa. In response to this research gap, I set out to examine the types of narratives and perceptions that print media and media consumers within an urban community have about FW. Since the study is centred around print media perceptions and narratives and those of the community, the study used a mixed-method approach that comprised of a media analysis, one-onone, semi structured interviews, key informant discussions as well as food focus groups. Thirty six respondents were interviewed with semi-structured one on one interviews, a further six respondents were key informants, they too were interviewed with one on one semi-structured interviews. Lastly, 16 were participants in the focus sessions, and each session comprised of 8 randomly selected participants. To procure the FW perceptions and narratives of print media and the people of Makhanda, the study was divided into three phases. Phase one comprised of a print media analysis through an archival media platform of SABINET. Phase two comprised of two food focus group sessions; phase three of the study comprised of the semi-structured interviews with 36 interviewees representing the general public and six with key informants. To make sense of the results obtained from the print media analysis, the study used the agenda setting framework and found that that the representation of FW content in print media was limited. Through the use of thematic analysis, 14 viii FW perceptions and narratives were identified in print media (and perceptions and narratives are used interchangeably, therefore 14 themes equals 14 FW perceptions and narratives). Of these 14 themes there were some that were more frequently presented than others. The most frequently presented perceptions and narratives in print media were the FW and food insecurity/hunger, FW and morality and FW and the economy. The study also found that a bulk of the FW content disseminated by print media belonged to a relatively few publications namely: Cape Argus, The Star, the Mail and Gurdian and the Daily Dispatch. These findings reinforced that FW perceptions and narratives in print media were not only disproportionally represented but were also disseminated by a limited pool of media content creators. The study found that Makhanda respondents used and preferred other media forms outside of print media i.e., radio and television. Respondents maintained that the media form they were the least exposed to and least preferred was print media (newspapers). From the 58 respondents, only seven respondents indicated that they listened to and preferred radio more than any other media form, and only two respondents noted that they read newspapers. In contrast, 24 respondents noted that they preferred and were more exposed to television than any other media form. In addition, respondents noted that they saw and heard a limited amount of FW content on the media that they were most exposed to. Instead, they noted that they were more exposed to content that encouraged them to procure and consume food, such as food advertisements. On average, individuals that were exposed to and preferred radio reported to hearing more FW content as opposed to individuals that preferred television. For instance, from the seven respondents that preferred and were most exposed to radio, four of them noted that they had heard a lot of FW content. While 17 of the 24 respondents that preferred and were most exposed to television, maintained that they did not recall seeing any FW content. The study also found that Makhanda respondents had a number of perceptions and narratives about FW, that were converted into themes using content and thematic analysis. The study found that Makhanda respondents had a total of 15 FW perceptions and narratives. Just like in the media analysis there were some perceptions and narratives that were emphasised and more frequently mentioned than others. The three most dominant themes were: affluence, FW and hunger, and FW and morality. Furthermore, the research also found that the perceptions and narratives of respondents were influenced by a variety of external and internal factors such as socio-economic status/affluence, gender, age, race, and media preference. These factors interacted with each other and varied in their significance from one respondent to the other. By far, the aspect shown to be the most influential in shaping respondents FW perceptions and narratives was affluence. Twentyeight respondents spoke about the economic drawbacks of FW and cited as reason for not engaging viii in FW. In addition to this, there were some respondents that maintained that FW did not occur amongst people who belonged to the lower socio-economic class and that rather, the phenomena were limited to those who were more affluent. In speaking about affluence, respondents e linked FW with other aspects such as race, gender, age, and media preference. For instance, in addition to claiming that FW was only limited to affluent households, other respondents felt that wasting food was a luxury the only white people participated in. Such claims highlight the idea that the sociocultural historical context of South Africa is one that has some influence in the FW perceptions and narratives of Makhanda respondents. The study found that there was little overlap in the types of perceptions and narratives that print media and the Makhanda respondents have about FW. From the 14 and 15 perceptions and narratives found between each realm there were only three thematic overlaps namely: the theme of affluence, morality and FW and food insecurity. This limited overlap of perceptions and narratives suggest that there is a disconnection present between the perceptions and narratives of print media and those that are exhibited by Makhanda respondents. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2024
- Full Text:
Investigating optoelectronic and thermal properties of perylene tetracarboxylic bisimide derivatives-and-cellulose nanocomposites for possible solar energy applications
- Ndwandwe, Bongeka Lethukukhanya
- Authors: Ndwandwe, Bongeka Lethukukhanya
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464554 , vital:76521
- Description: Restricted access. Expected release in 2026. , Thesis (MSc) -- Faculty of Science, Chemistry, 2024
- Full Text:
- Authors: Ndwandwe, Bongeka Lethukukhanya
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464554 , vital:76521
- Description: Restricted access. Expected release in 2026. , Thesis (MSc) -- Faculty of Science, Chemistry, 2024
- Full Text:
Participatory mapping of key drivers of ecological change and analysing equity dimensions of ecosystem services flow in the Kat River Catchment
- Authors: Seriki, Esther Ahuoiza
- Date: 2024-10-11
- Subjects: Ecological change , Ecosystem services South Africa Kat River Valley , Participatory GIS , Freshwater ecosystem , Social equity
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/465024 , vital:76566
- Description: Rivers are important ecosystems which supply ecosystem services critical to social-economic well-being. However, many rivers are degraded due to human activities. Degradation of river systems compromises the quality and quantity of ecosystem services they can supply. Managing important drivers of ecological change requires broad-based stakeholder participation to mobilise collective actions for an effective rehabilitation strategy. This study looked at two crucial research objectives in the Kat River catchment. The first was to undertake a multidimensional, participatory, engaged mapping of ecological changes, as well as current and changing ecosystem services in the Kat River catchment, and the second was to analyse the equity dimensions of ecosystem services flow in the Kat River catchment. Data were collected through semi-structured interviews and participatory GIS mapping exercises. A purposive sampling method was applied to recruit research participants for interviews and workshops. Between March 13th and May 31st, 2023, thirty-one (31) participants representing four social groups, non-farming individuals, catchment management forum members, commercial and subsistence farmers, participated in interviews. Additionally, twenty-two (22) stakeholders attended 2-day workshops held between 20−21 April 2022, and 30−31 May 2023. Data collected from interviews and workshops were analysed using thematic analysis. The results of stakeholder perceptions regarding the perceived ecological changes and their key drivers in the Kat River catchment revealed a concerning trend. Participants reported significant changes to the catchment area over time, including increased occurrences of flooding and water pollution and decreased aquatic biodiversity. Furthermore, degradation of ecosystem services, such as water quality, availability of medicinal plants, reeds, and fish populations, was noted. These environmental shifts have been accompanied by a rise in social-economic burdens, including the prevalence of water-borne diseases, cultural burdens (particularly the inability of certain groups to access ancestral grave sites) and declining fish populations. These findings emphasise the urgent need for intervention strategies to mitigate further degradation of the catchment area and safeguard the well-being of both the human population and the integrity of the ecosystems. Recommended intervention measures include improving wastewater management practices and creating targeted public awareness campaigns. By addressing these challenges, stakeholders can work towards preserving the integrity of the catchment area, protecting water resources and conserving biodiversity for future generations. The equity dimensions (distributive and procedural equity) analysis revealed notable disparities in access to the benefits of ecosystem services, as well as in participation of residents in the Kat River Water Users Association. Certain social groups, such as commercial farmers, were observed to receive more benefits from ecosystem services, while other groups, including the elderly and disabled individuals, seem to be negatively impacted by the activities of those who benefit most from ecosystem services in the Kat River catchment. This raises not only an equity issue but also the issue of how costs are externalised by certain groups. Of particular concern was the finding that seventy (70) per cent of the research participants were not aware of the presence of the Kat River Water Users Association, raising concerns about procedural equity in water resource management processes. Additionally, ninety (90) per cent of the participants had the perception that there was unfair water access and allocation across the various social groups, highlighting possible distributive inequities. The participants expressed a clear interest in learning more about the existence and operation of the Kat River Water Users Association, signalling a need for increased awareness and participation among social groups. Addressing these equity concerns is crucial to ensure that water resource management processes are designed to provide all stakeholders and water-dependent actors with equitable and fair access to decision making. Moving forward, efforts should be directed towards raising awareness of the Kat River Water Users Association and to promoting inclusive participation among all social groups. This awareness may involve targeted outreach campaigns, community engagement initiatives and policy reforms to foster more equitable water governance practices within the catchment. , Thesis (MSc) -- Faculty of Science, Institute for Water Research, 2024
- Full Text:
- Authors: Seriki, Esther Ahuoiza
- Date: 2024-10-11
- Subjects: Ecological change , Ecosystem services South Africa Kat River Valley , Participatory GIS , Freshwater ecosystem , Social equity
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/465024 , vital:76566
- Description: Rivers are important ecosystems which supply ecosystem services critical to social-economic well-being. However, many rivers are degraded due to human activities. Degradation of river systems compromises the quality and quantity of ecosystem services they can supply. Managing important drivers of ecological change requires broad-based stakeholder participation to mobilise collective actions for an effective rehabilitation strategy. This study looked at two crucial research objectives in the Kat River catchment. The first was to undertake a multidimensional, participatory, engaged mapping of ecological changes, as well as current and changing ecosystem services in the Kat River catchment, and the second was to analyse the equity dimensions of ecosystem services flow in the Kat River catchment. Data were collected through semi-structured interviews and participatory GIS mapping exercises. A purposive sampling method was applied to recruit research participants for interviews and workshops. Between March 13th and May 31st, 2023, thirty-one (31) participants representing four social groups, non-farming individuals, catchment management forum members, commercial and subsistence farmers, participated in interviews. Additionally, twenty-two (22) stakeholders attended 2-day workshops held between 20−21 April 2022, and 30−31 May 2023. Data collected from interviews and workshops were analysed using thematic analysis. The results of stakeholder perceptions regarding the perceived ecological changes and their key drivers in the Kat River catchment revealed a concerning trend. Participants reported significant changes to the catchment area over time, including increased occurrences of flooding and water pollution and decreased aquatic biodiversity. Furthermore, degradation of ecosystem services, such as water quality, availability of medicinal plants, reeds, and fish populations, was noted. These environmental shifts have been accompanied by a rise in social-economic burdens, including the prevalence of water-borne diseases, cultural burdens (particularly the inability of certain groups to access ancestral grave sites) and declining fish populations. These findings emphasise the urgent need for intervention strategies to mitigate further degradation of the catchment area and safeguard the well-being of both the human population and the integrity of the ecosystems. Recommended intervention measures include improving wastewater management practices and creating targeted public awareness campaigns. By addressing these challenges, stakeholders can work towards preserving the integrity of the catchment area, protecting water resources and conserving biodiversity for future generations. The equity dimensions (distributive and procedural equity) analysis revealed notable disparities in access to the benefits of ecosystem services, as well as in participation of residents in the Kat River Water Users Association. Certain social groups, such as commercial farmers, were observed to receive more benefits from ecosystem services, while other groups, including the elderly and disabled individuals, seem to be negatively impacted by the activities of those who benefit most from ecosystem services in the Kat River catchment. This raises not only an equity issue but also the issue of how costs are externalised by certain groups. Of particular concern was the finding that seventy (70) per cent of the research participants were not aware of the presence of the Kat River Water Users Association, raising concerns about procedural equity in water resource management processes. Additionally, ninety (90) per cent of the participants had the perception that there was unfair water access and allocation across the various social groups, highlighting possible distributive inequities. The participants expressed a clear interest in learning more about the existence and operation of the Kat River Water Users Association, signalling a need for increased awareness and participation among social groups. Addressing these equity concerns is crucial to ensure that water resource management processes are designed to provide all stakeholders and water-dependent actors with equitable and fair access to decision making. Moving forward, efforts should be directed towards raising awareness of the Kat River Water Users Association and to promoting inclusive participation among all social groups. This awareness may involve targeted outreach campaigns, community engagement initiatives and policy reforms to foster more equitable water governance practices within the catchment. , Thesis (MSc) -- Faculty of Science, Institute for Water Research, 2024
- Full Text:
Search for acrylonitrile-based inhibitors of SAR-Cov-19 main and papain-like proteases through covalent docking and high-throughput virtual screening
- Authors: Ntantiso, Yamkela
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/463941 , vital:76459
- Description: The sudden outbreak of SARS-CoV-2 formerly known as the 2019 novel coronavirus (2019-nCoV) quickly turned into a pandemic of coronavirus disease 2019 (COVID-19), the scale of which has never been seen before. High infection rates and mortality from COVID-19 placed pressure on global health services, and this has been to the detriment of the global economy. However, treatment options for COVID-19 are still very limited; hence, it is now as important as ever that researchers explore searching for new compounds with pharmacokinetic properties that inhibit the two COVID proteases - the main protease (Mpro) and the papain-like protease (PLpro). The main protease is a cysteine protease; as such, it is susceptible to permanent inhibition by reactive species (warheads) that may covalently bind to cysteine residues. One such class of compounds is acrylonitriles, in which the reactive acrylonitrile is reactive towards cysteine through a Michael addition reaction. The resulting covalent interaction is permanent and inactivates the cysteine residue and hence the protease within the context of the COVID-19 life-cycle. In this context, this study seeks to utilize computational-based approaches to identify acrylonitrile-based inhibitors of coronavirus drug targets. To do this, the ZINC database has been screened for compounds containing acrylonitrile functionality, due to its known nature as a warhead that binds to cysteine residues. Pharmacokinetic properties are computed to evaluate the viability of identified inhibitors, and covalent and non-covalent molecular docking approaches to the Mpro enzyme crystal structure have also been used to assess the identified systems. To gather more information and evaluate the most promising systems, a subset of the most promising compounds have been subjected to molecular dynamics simulation (for both covalently bound and non-covalently bound systems). , Thesis (MSc) -- Faculty of Science, Biochemistry, Microbiology & Bioinformatics, 2024
- Full Text:
- Authors: Ntantiso, Yamkela
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/463941 , vital:76459
- Description: The sudden outbreak of SARS-CoV-2 formerly known as the 2019 novel coronavirus (2019-nCoV) quickly turned into a pandemic of coronavirus disease 2019 (COVID-19), the scale of which has never been seen before. High infection rates and mortality from COVID-19 placed pressure on global health services, and this has been to the detriment of the global economy. However, treatment options for COVID-19 are still very limited; hence, it is now as important as ever that researchers explore searching for new compounds with pharmacokinetic properties that inhibit the two COVID proteases - the main protease (Mpro) and the papain-like protease (PLpro). The main protease is a cysteine protease; as such, it is susceptible to permanent inhibition by reactive species (warheads) that may covalently bind to cysteine residues. One such class of compounds is acrylonitriles, in which the reactive acrylonitrile is reactive towards cysteine through a Michael addition reaction. The resulting covalent interaction is permanent and inactivates the cysteine residue and hence the protease within the context of the COVID-19 life-cycle. In this context, this study seeks to utilize computational-based approaches to identify acrylonitrile-based inhibitors of coronavirus drug targets. To do this, the ZINC database has been screened for compounds containing acrylonitrile functionality, due to its known nature as a warhead that binds to cysteine residues. Pharmacokinetic properties are computed to evaluate the viability of identified inhibitors, and covalent and non-covalent molecular docking approaches to the Mpro enzyme crystal structure have also been used to assess the identified systems. To gather more information and evaluate the most promising systems, a subset of the most promising compounds have been subjected to molecular dynamics simulation (for both covalently bound and non-covalently bound systems). , Thesis (MSc) -- Faculty of Science, Biochemistry, Microbiology & Bioinformatics, 2024
- Full Text:
Examining the expenditures and retention of money of recreational fishing along the Wild Coast, South Africa
- Authors: Pyle, Michael Jonathan
- Date: 2023-10-13
- Subjects: Ecotourism South Africa , Sustainable fisheries South Africa , Wild Coast Region , Small-scale fisheries Economic aspects South Africa , Socioeconomic development , Leakage
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419673 , vital:71665
- Description: Developing countries and rural communities rely heavily on the ocean for food, transport, and the sustainability of their livelihoods. While the economics of small-scale fisheries in rural areas have received much attention, there is generally less information on the economic contributions from recreational fisheries in these areas. South Africa’s marine recreational fishery is large and contributes to a significant amount of economic activity. However, the retention of money from recreational fishing activities in local rural economies is unknown and thus the potential developmental benefits from this sector remain unquantified. This study examined the economic contributions from recreational fishing along the Wild Coast and retention of expenditures within the local economy. A total of 109 face-to-face economic surveys were administered during the peak recreational fishing season in December 2021. Based on the results, recreational fishing in the Wild Coast has the ability to generate R 415 446 098 in economic activity annually, however only 9.5% of this is retained within local coastal economies, which diminishes the economic contributions of the fishery to the Wild Coast region. Expenditures on items stemming from the informal collection and selling of bait and seafood, domestic work and guiding were the highest locally retained expenditures within the region. 98% of all bait and seafood was harvested and sold by local gillies, with 2% being bought through hotels (n=109). The total direct economic contribution in terms of informal harvesting was estimated at R 16 077 711 for 2021 (n= 9 601). The identification of these contributions can be used to provide recommendations for local economic development strategies which can support the recreational fishery while uplifting coastal communities that should be benefitting more from the activity. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2023
- Full Text:
- Authors: Pyle, Michael Jonathan
- Date: 2023-10-13
- Subjects: Ecotourism South Africa , Sustainable fisheries South Africa , Wild Coast Region , Small-scale fisheries Economic aspects South Africa , Socioeconomic development , Leakage
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419673 , vital:71665
- Description: Developing countries and rural communities rely heavily on the ocean for food, transport, and the sustainability of their livelihoods. While the economics of small-scale fisheries in rural areas have received much attention, there is generally less information on the economic contributions from recreational fisheries in these areas. South Africa’s marine recreational fishery is large and contributes to a significant amount of economic activity. However, the retention of money from recreational fishing activities in local rural economies is unknown and thus the potential developmental benefits from this sector remain unquantified. This study examined the economic contributions from recreational fishing along the Wild Coast and retention of expenditures within the local economy. A total of 109 face-to-face economic surveys were administered during the peak recreational fishing season in December 2021. Based on the results, recreational fishing in the Wild Coast has the ability to generate R 415 446 098 in economic activity annually, however only 9.5% of this is retained within local coastal economies, which diminishes the economic contributions of the fishery to the Wild Coast region. Expenditures on items stemming from the informal collection and selling of bait and seafood, domestic work and guiding were the highest locally retained expenditures within the region. 98% of all bait and seafood was harvested and sold by local gillies, with 2% being bought through hotels (n=109). The total direct economic contribution in terms of informal harvesting was estimated at R 16 077 711 for 2021 (n= 9 601). The identification of these contributions can be used to provide recommendations for local economic development strategies which can support the recreational fishery while uplifting coastal communities that should be benefitting more from the activity. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2023
- Full Text:
The obligation of South Africa to provide social security to refugees and asylum seekers during the COVID-19 pandemic
- Authors: Dekeda, Awethu Zethu
- Date: 2023-10-13
- Subjects: Social security Law and legislation South Africa , Human rights South Africa , Refugees Government policy South Africa , Political refugees South Africa , COVID-19 Pandemic, 2020- Influence
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424119 , vital:72125
- Description: Covid-19 a novel pandemic, has wreaked havoc globally, threatening the livelihoods of all, including refugees and asylum seekers. Like all other countries globally, South Africa has gone to great lengths to mitigate the challenges that this pandemic has caused. However, it is far from clear whether these responses are according due regard to the rights of some of the most vulnerable in society, amongst which are refugees. This thesis deals with South Africa’s obligation to provide social security to refugees during the Covid-19 pandemic. It specifically assesses whether South Africa's responses to the Covid-19 pandemic were in adherence to fundamental refugee law principles relevant to the protection of refugees. The study commences with a general introduction, followed by an analysis of the international human rights and refugee law framework relevant to protection of refugees. This framework is used to assess South Africa’s responses. Subsequently, the discussion delves into South Africa’s own national framework on social security. Using the standards identified in both the national and international frameworks, the thesis then proceeds to measure South Africa’s Covid-19 related responses regarding social security to resolve the issue of whether South Africa adhered to these standards in as far the protection of refugees’ right to social security is concerned. , Thesis (LLM) -- Faculty of Law, Law, 2023
- Full Text:
- Authors: Dekeda, Awethu Zethu
- Date: 2023-10-13
- Subjects: Social security Law and legislation South Africa , Human rights South Africa , Refugees Government policy South Africa , Political refugees South Africa , COVID-19 Pandemic, 2020- Influence
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424119 , vital:72125
- Description: Covid-19 a novel pandemic, has wreaked havoc globally, threatening the livelihoods of all, including refugees and asylum seekers. Like all other countries globally, South Africa has gone to great lengths to mitigate the challenges that this pandemic has caused. However, it is far from clear whether these responses are according due regard to the rights of some of the most vulnerable in society, amongst which are refugees. This thesis deals with South Africa’s obligation to provide social security to refugees during the Covid-19 pandemic. It specifically assesses whether South Africa's responses to the Covid-19 pandemic were in adherence to fundamental refugee law principles relevant to the protection of refugees. The study commences with a general introduction, followed by an analysis of the international human rights and refugee law framework relevant to protection of refugees. This framework is used to assess South Africa’s responses. Subsequently, the discussion delves into South Africa’s own national framework on social security. Using the standards identified in both the national and international frameworks, the thesis then proceeds to measure South Africa’s Covid-19 related responses regarding social security to resolve the issue of whether South Africa adhered to these standards in as far the protection of refugees’ right to social security is concerned. , Thesis (LLM) -- Faculty of Law, Law, 2023
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The yield spread as a predictor for buy or sell signals for sectoral indices of the JSE
- Authors: Roeber, Christine
- Date: 2023-10-13
- Subjects: Yield curve , Rate of return South Africa , Yield spread , Interest rate , Johannesburg Stock Exchange
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419687 , vital:71666
- Description: The predictive nature of the yield curve has been of interest to researchers for years. In this thesis, the evidence for the yield curve as a predictor is examine, specifically as a predictor for bear markets in the JSE stock market for 8 sub-sectoral indices. The study explores a dynamic market timing strategy for timing the South African stock market compared to a normal buy-and-hold strategy. First, probit models are estimated for each of the sectoral indices which did not prove to have tracked well all the bear market phases. Then a dynamic market timing portfolio is simulated against a buy-and-hold only strategy, the dynamic market timing portfolio proved to have outperformed a buy-and-hold strategy for almost all the indices. Thus, a Henriksson-Merton parametric model test which tests for market timing ability was done on these sub-indices. The research finds that the yield curve in South Africa is not a useful tool for a buy-sell strategy for most of the sub-sectoral indices of the JSE. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2023
- Full Text:
- Authors: Roeber, Christine
- Date: 2023-10-13
- Subjects: Yield curve , Rate of return South Africa , Yield spread , Interest rate , Johannesburg Stock Exchange
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419687 , vital:71666
- Description: The predictive nature of the yield curve has been of interest to researchers for years. In this thesis, the evidence for the yield curve as a predictor is examine, specifically as a predictor for bear markets in the JSE stock market for 8 sub-sectoral indices. The study explores a dynamic market timing strategy for timing the South African stock market compared to a normal buy-and-hold strategy. First, probit models are estimated for each of the sectoral indices which did not prove to have tracked well all the bear market phases. Then a dynamic market timing portfolio is simulated against a buy-and-hold only strategy, the dynamic market timing portfolio proved to have outperformed a buy-and-hold strategy for almost all the indices. Thus, a Henriksson-Merton parametric model test which tests for market timing ability was done on these sub-indices. The research finds that the yield curve in South Africa is not a useful tool for a buy-sell strategy for most of the sub-sectoral indices of the JSE. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2023
- Full Text:
Vulamasango Singene: sociological analysis of a rural social movement
- Authors: Kirchmann, Gail Lynne
- Date: 2023-10-13
- Subjects: Social movements South Africa Eastern Cape , Land reform South Africa , Non-governmental organizations South Africa , Reparations for historical injustices South Africa , Betterments South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425132 , vital:72213
- Description: This dissertation tests the claim made by a large membership-based organisation that it is a social movement. The organisation, Vulamasango Singene (VS) operates across the rural areas of large parts of the Eastern Cape Province. It has, for twenty years, advocated for the re-opening of land restitution claims for a specific category of forced removal known as “betterment”. This study provides an analysis of an organisation that has yet to achieve its objective in spite of sufficient financial resources, logistical and strategic support, numeric strength and the legal clarity of its demand. The research is situated within the framework of social movement theory. The study examined the origins, institutional infrastructure, demographic make-up, activities and culture of VS. These were analysed against four components that are identified in the literature as key characteristics of a social movement. These are: (i) informal networks (as opposed to structured and managed engagements); (ii) a plurality of actors (as opposed to a homogenous grouping); (iii) mobilising around issues of conflict; and (iv) sharing common beliefs and demonstrating solidarity. Data were gathered through an archival study and field research. Semi-structured interviews were carried out with a sample of VS’s leadership, and staff of the non-governmental organisation in which VS originated, as well as expert informants in the land reform arena. The findings with respect to each of the criteria were: (i) VS’s structure was rigid and internal communication was largely formal. (ii) There was almost no demographic or political diversity within VS. (iii) VS had, in the past, mobilised around issues of conflict, but there had been no mobilisation for ten years. (iv) While there was some evidence of sharing common beliefs and demonstrating solidarity, this was limited. The conclusion reached was that VS is not a social movement. This does not imply that VS is not an important democratic or representative organisation. It does, however, provide a theoretical position from which VS, and other organisations, can direct further action. The study touched on the relationship between northern donors, local professional NGOs and grassroots organisations in South Africa. Interactions among these institutions impact on the way that organisations and social movements develop. Comparisons with other similar organisations were made and similarities and differences were highlighted. It was suggested that, because of the importance of the issue, further research in this regard is necessary. , Thesis (MA) -- Faculty of Humanities, Sociology, 2023
- Full Text:
- Authors: Kirchmann, Gail Lynne
- Date: 2023-10-13
- Subjects: Social movements South Africa Eastern Cape , Land reform South Africa , Non-governmental organizations South Africa , Reparations for historical injustices South Africa , Betterments South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425132 , vital:72213
- Description: This dissertation tests the claim made by a large membership-based organisation that it is a social movement. The organisation, Vulamasango Singene (VS) operates across the rural areas of large parts of the Eastern Cape Province. It has, for twenty years, advocated for the re-opening of land restitution claims for a specific category of forced removal known as “betterment”. This study provides an analysis of an organisation that has yet to achieve its objective in spite of sufficient financial resources, logistical and strategic support, numeric strength and the legal clarity of its demand. The research is situated within the framework of social movement theory. The study examined the origins, institutional infrastructure, demographic make-up, activities and culture of VS. These were analysed against four components that are identified in the literature as key characteristics of a social movement. These are: (i) informal networks (as opposed to structured and managed engagements); (ii) a plurality of actors (as opposed to a homogenous grouping); (iii) mobilising around issues of conflict; and (iv) sharing common beliefs and demonstrating solidarity. Data were gathered through an archival study and field research. Semi-structured interviews were carried out with a sample of VS’s leadership, and staff of the non-governmental organisation in which VS originated, as well as expert informants in the land reform arena. The findings with respect to each of the criteria were: (i) VS’s structure was rigid and internal communication was largely formal. (ii) There was almost no demographic or political diversity within VS. (iii) VS had, in the past, mobilised around issues of conflict, but there had been no mobilisation for ten years. (iv) While there was some evidence of sharing common beliefs and demonstrating solidarity, this was limited. The conclusion reached was that VS is not a social movement. This does not imply that VS is not an important democratic or representative organisation. It does, however, provide a theoretical position from which VS, and other organisations, can direct further action. The study touched on the relationship between northern donors, local professional NGOs and grassroots organisations in South Africa. Interactions among these institutions impact on the way that organisations and social movements develop. Comparisons with other similar organisations were made and similarities and differences were highlighted. It was suggested that, because of the importance of the issue, further research in this regard is necessary. , Thesis (MA) -- Faculty of Humanities, Sociology, 2023
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Technological pedagogical content knowledge development: investigating secondary school teachers' integration and use of technology during emergency remote teaching in Endola education circuit
- Authors: Munyanyo, Johanna
- Date: 2023-10
- Subjects: Pedagogical content knowledge , Social distancing (Public health) and education , Distance teaching , Educational technology , Technological Pedagogical Content Knowledge
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/423882 , vital:72101
- Description: The Covid-19 pandemic has created the largest disruption of education systems in human history. The closure of schools and other learning spaces has impacted billions of learners worldwide. The mitigative measures and many new standard operating procedures have brought restrictions and many challenges. The face-to-face traditional teaching method lost its value, and teaching shifted to distance through the integration of technologies. The integration of technologies necessitated the emergency remote teaching process, as it is one of the distance teaching modes that can make teaching possible even for less technologically privileged nations. Literature has shown that the integration and usage of technology during teaching support the development of technological pedagogical and content knowledge (TPACK) of teachers. This study, therefore, sought to investigate how the integration and use of technology during the emergency remote teaching of Covid-19 developed the secondary school teachers’ technological pedagogical and content knowledge. The study is underpinned by an interpretive paradigm, and a qualitative case study approach was employed. It was conducted in seven secondary schools in the Endola education circuit, Ohangwena region, with the purposeful participation of twenty-six secondary school teachers. Data was collected using semi-structured questionnaires and semi-structured interviews. The study was informed by Vygotsky’s (1978) sociocultural theory together with the TPACK framework of Thompson and Mishra (2007) as both theoretical and analytical frameworks. The study's results showed that teachers made use of existing technological resources to sustain their teaching efforts during ERT. They encountered various challenges, including a lack of technological expertise (knowledge) among both teachers and learners. The shift to virtual instruction during ERT supported teachers in developing proficient technological pedagogical content knowledge. This research concludes that schools possess the necessary technological infrastructure to enable teachers to incorporate technology into their teaching methods. Furthermore, it highlights that teachers generally hold favourable attitudes toward integrating technology into their instruction. Nevertheless, it recommends that there is a need for improving both in-service and pre-service teachers’ training and support for effectively teaching in online and blended learning environments. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2023
- Full Text:
- Authors: Munyanyo, Johanna
- Date: 2023-10
- Subjects: Pedagogical content knowledge , Social distancing (Public health) and education , Distance teaching , Educational technology , Technological Pedagogical Content Knowledge
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/423882 , vital:72101
- Description: The Covid-19 pandemic has created the largest disruption of education systems in human history. The closure of schools and other learning spaces has impacted billions of learners worldwide. The mitigative measures and many new standard operating procedures have brought restrictions and many challenges. The face-to-face traditional teaching method lost its value, and teaching shifted to distance through the integration of technologies. The integration of technologies necessitated the emergency remote teaching process, as it is one of the distance teaching modes that can make teaching possible even for less technologically privileged nations. Literature has shown that the integration and usage of technology during teaching support the development of technological pedagogical and content knowledge (TPACK) of teachers. This study, therefore, sought to investigate how the integration and use of technology during the emergency remote teaching of Covid-19 developed the secondary school teachers’ technological pedagogical and content knowledge. The study is underpinned by an interpretive paradigm, and a qualitative case study approach was employed. It was conducted in seven secondary schools in the Endola education circuit, Ohangwena region, with the purposeful participation of twenty-six secondary school teachers. Data was collected using semi-structured questionnaires and semi-structured interviews. The study was informed by Vygotsky’s (1978) sociocultural theory together with the TPACK framework of Thompson and Mishra (2007) as both theoretical and analytical frameworks. The study's results showed that teachers made use of existing technological resources to sustain their teaching efforts during ERT. They encountered various challenges, including a lack of technological expertise (knowledge) among both teachers and learners. The shift to virtual instruction during ERT supported teachers in developing proficient technological pedagogical content knowledge. This research concludes that schools possess the necessary technological infrastructure to enable teachers to incorporate technology into their teaching methods. Furthermore, it highlights that teachers generally hold favourable attitudes toward integrating technology into their instruction. Nevertheless, it recommends that there is a need for improving both in-service and pre-service teachers’ training and support for effectively teaching in online and blended learning environments. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2023
- Full Text:
A review of the Siyakhula Living Lab’s network solution for Internet in marginalized communities
- Muchatibaya, Hilbert Munashe
- Authors: Muchatibaya, Hilbert Munashe
- Date: 2022-10-14
- Subjects: Information and communication technologies for development , Information technology South Africa , Access network , User experience , Local area networks (Computer networks) South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/364943 , vital:65664
- Description: Changes within Information and Communication Technology (ICT) over the past decade required a review of the network layer component deployed in the Siyakhula Living Lab (SLL), a long-term joint venture between the Telkom Centres of Excellence hosted at University of Fort Hare and Rhodes University in South Africa. The SLL overall solution for the sustainable internet in poor communities consists of three main components – the computing infrastructure layer, the network layer, and the e-services layer. At the core of the network layer is the concept of BI, a high-speed local area network realized through easy-to deploy wireless technologies that establish point-to-multipoint connections among schools within a limited geographical area. Schools within the broadband island become then Digital Access Nodes (DANs), with computing infrastructure that provides access to the network. The review, reported in this thesis, aimed at determining whether the model for the network layer was still able to meet the needs of marginalized communities in South Africa, given the recent changes in ICT. The research work used the living lab methodology – a grassroots, user-driven approach that emphasizes co-creation between the beneficiaries and external entities (researchers, industry partners and the government) - to do viability tests on the solution for the network component. The viability tests included lab and field experiments, to produce the qualitative and quantitative data needed to propose an updated blueprint. The results of the review found that the network topology used in the SLL’s network, the BI, is still viable, while WiMAX is now outdated. Also, the in-network web cache, Squid, is no longer effective, given the switch to HTTPS and the pervasive presence of advertising. The solution to the first issue is outdoor Wi-Fi, a proven solution easily deployable in grass-roots fashion. The second issue can be mitigated by leveraging Squid’s ‘bumping’ and splicing features; deploying a browser extension to make picture download optional; and using Pihole, a DNS sinkhole. Hopefully, the revised solution could become a component of South African Government’s broadband plan, “SA Connect”. , Thesis (MSc) -- Faculty of Science, Computer Science, 2022
- Full Text:
- Authors: Muchatibaya, Hilbert Munashe
- Date: 2022-10-14
- Subjects: Information and communication technologies for development , Information technology South Africa , Access network , User experience , Local area networks (Computer networks) South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/364943 , vital:65664
- Description: Changes within Information and Communication Technology (ICT) over the past decade required a review of the network layer component deployed in the Siyakhula Living Lab (SLL), a long-term joint venture between the Telkom Centres of Excellence hosted at University of Fort Hare and Rhodes University in South Africa. The SLL overall solution for the sustainable internet in poor communities consists of three main components – the computing infrastructure layer, the network layer, and the e-services layer. At the core of the network layer is the concept of BI, a high-speed local area network realized through easy-to deploy wireless technologies that establish point-to-multipoint connections among schools within a limited geographical area. Schools within the broadband island become then Digital Access Nodes (DANs), with computing infrastructure that provides access to the network. The review, reported in this thesis, aimed at determining whether the model for the network layer was still able to meet the needs of marginalized communities in South Africa, given the recent changes in ICT. The research work used the living lab methodology – a grassroots, user-driven approach that emphasizes co-creation between the beneficiaries and external entities (researchers, industry partners and the government) - to do viability tests on the solution for the network component. The viability tests included lab and field experiments, to produce the qualitative and quantitative data needed to propose an updated blueprint. The results of the review found that the network topology used in the SLL’s network, the BI, is still viable, while WiMAX is now outdated. Also, the in-network web cache, Squid, is no longer effective, given the switch to HTTPS and the pervasive presence of advertising. The solution to the first issue is outdoor Wi-Fi, a proven solution easily deployable in grass-roots fashion. The second issue can be mitigated by leveraging Squid’s ‘bumping’ and splicing features; deploying a browser extension to make picture download optional; and using Pihole, a DNS sinkhole. Hopefully, the revised solution could become a component of South African Government’s broadband plan, “SA Connect”. , Thesis (MSc) -- Faculty of Science, Computer Science, 2022
- Full Text:
Design, synthesis, manufacture, characterization and evaluation of lipid nanocapsules in chitosan-iota-carrageenan based hydrogel scaffold as a potential anti-Covid-19 drug delivery system
- Authors: Mukubwa, Grady Kathondo
- Date: 2022-10-14
- Subjects: Nanocapsules Design , Hydrogel , COVID-19 (Disease) , Characterization , Drug delivery systems
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/364955 , vital:65665
- Description: Covid-19 is a deadly viral disease that has been rampant around the world since 2019. Although the successful introduction of the vaccine has reduced the spread of covid-19, new cases and deaths are still being recorded. To date, no specific curative antiviral treatment has been approved for covid-19. However, many existing antiviral drugs have been and are still being studied against covid-19 and some of them, such as Remdesivir, have shown promise and could be repurposed to treat this infection. Unfortunately, antiviral drugs are prone to resistance as most of them have poor biopharmaceutical properties, including low solubility, permeability and bioavailability, which could hinder any clinical success. Recent advances in nanotechnology-based delivery systems have made it possible to improve the biopharmaceutical properties of many drugs, especially those of poorly water-soluble drugs, by formulating them as lipid nanoparticles (LNP). Thus, in order to contribute to the fight against covid-19, this work aimed to develop Lipid Nanocapsules (LNC), based on some natural raw materials, which could improve the biopharmaceutical properties of antiviral drugs. In addition, since covid-19 infection is mainly respiratory, this work also aimed to fabricate a targeted delivery system based on a hydrogel capable of entrapping LNC and ensuring their efficient deposition and release in the lungs. The LNC consisted of a mixture of medium-chain triglycerides oil (MCT oil), crude soy lecithin, tween 80, NaCl and water, while the hydrogel consisted of a chitosan-grafted-iota carrageenan-grafted-poly (acrylamide-co-acrylic acid) system (CS-iCar-p (AAm-Co-AA)). Efavirenz (EFV), a drug with very low water solubility that has recently been demonstrated to have the potential to influence sars-cov-2 life cycle through different targets (3CLP, RdRp, Hellicase, 3’to5’exonuclease, 2’-O-ribose methyltransferase and EndoRNAse), was chosen as the model drug to evaluate the developed delivery system. The combination of LNP and hydrogel results in a delivery system known as the LNP-hydrogel composite, an emerging area of research in the field of drug delivery. To date, no research has reported the design and fabrication of an LNC-CS-iCar-p (AAm-Co-AA) hydrogel composite that could effectively deliver an antiviral drug to the lungs in addition to its advantages in terms of biological activities. Prior to the design of experiment, EFV solubility was assessed in water, labrafac lipophile 1349 and MCT oil. After that, the Design Expert Software version 13 was used to design the different experiments performed in this work. The I-optimal mixture design of experiments was performed for both LNC preparation and CS-iCar-p (AAm-Co-AA) hydrogel synthesis to study the impact of raw materials on the characteristics of these delivery systems. LNC were prepared using the phase inversion method while the free radical precipitation graft copolymerization method was used to synthesize hydrogel. In order to build polynomial models that could predict the amount of drug both LNC and CS-iCar-p (AAm-Co-AA) hydrogel can entrap, a D-optimal (custom) randomized design was performed. Moreover, various characterization techniques were used to investigate the physicochemical properties of the developed delivery systems. Thereafter, drug release studies were performed using a 1% sodium lauryl sulfate solution adjusted to either pH 4 or 7. Solubility studies revealed that EFV was more soluble in labrafac lipophile 1349 and in MCT oil than in water; therefore, given its affordability, MCT oil was used for the LNC formulation. The design of experiment carried out allowed the construction of polynomial models that could predict, on the one hand, the droplet size, the polydispersity index and the Zeta potential of LNC, which were respectively around 50nm, below 0.2 and below -33. On the other hand, the model could predict the swelling capacity of the synthesized hydrogel, which was optimised to about 30,000% (300 g of water to 1 g of hydrogel). This turned out to be influenced by the proportion of polymers, the ratio of monomers as well as the concentration of the cross-linking agent. In addition, the characterization techniques further supported the improvement of EFV solubility by highlighting its conversion into its amorphous state after encapsulation in LNC. They also confirmed successful synthesis of CS-iCar-p (AAm-co-AA) hydrogel. LNC were able to encapsulate about 87% of EFV while the synthesized CS-iCar-p (AAm-co-AA) hydrogel entrapped around 53% of EFV encapsulated in LNC. While LNC were able to release 42% and 27% of EFV after 74 hours in a 1% sodium lauryl sulfate solution (SLS) at pH 7 and pH 4 respectively, the LNC-CS-iCar-p (AAm-co-AA) hydrogel composite released about 50% and 40% of the drug after 9 days in the same release medium. Interestingly, the chemical integrity of the drug was preserved throughout the manufacturing process up to after its release, suggesting that the developed LNC-CS-iCar-p (AAm-co-AA) hydrogel composite could be used as a novel potential anticovid-19 drugs delivery system. , Thesis (MSc) -- Faculty of Science, Chemistry, 2022
- Full Text:
- Authors: Mukubwa, Grady Kathondo
- Date: 2022-10-14
- Subjects: Nanocapsules Design , Hydrogel , COVID-19 (Disease) , Characterization , Drug delivery systems
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/364955 , vital:65665
- Description: Covid-19 is a deadly viral disease that has been rampant around the world since 2019. Although the successful introduction of the vaccine has reduced the spread of covid-19, new cases and deaths are still being recorded. To date, no specific curative antiviral treatment has been approved for covid-19. However, many existing antiviral drugs have been and are still being studied against covid-19 and some of them, such as Remdesivir, have shown promise and could be repurposed to treat this infection. Unfortunately, antiviral drugs are prone to resistance as most of them have poor biopharmaceutical properties, including low solubility, permeability and bioavailability, which could hinder any clinical success. Recent advances in nanotechnology-based delivery systems have made it possible to improve the biopharmaceutical properties of many drugs, especially those of poorly water-soluble drugs, by formulating them as lipid nanoparticles (LNP). Thus, in order to contribute to the fight against covid-19, this work aimed to develop Lipid Nanocapsules (LNC), based on some natural raw materials, which could improve the biopharmaceutical properties of antiviral drugs. In addition, since covid-19 infection is mainly respiratory, this work also aimed to fabricate a targeted delivery system based on a hydrogel capable of entrapping LNC and ensuring their efficient deposition and release in the lungs. The LNC consisted of a mixture of medium-chain triglycerides oil (MCT oil), crude soy lecithin, tween 80, NaCl and water, while the hydrogel consisted of a chitosan-grafted-iota carrageenan-grafted-poly (acrylamide-co-acrylic acid) system (CS-iCar-p (AAm-Co-AA)). Efavirenz (EFV), a drug with very low water solubility that has recently been demonstrated to have the potential to influence sars-cov-2 life cycle through different targets (3CLP, RdRp, Hellicase, 3’to5’exonuclease, 2’-O-ribose methyltransferase and EndoRNAse), was chosen as the model drug to evaluate the developed delivery system. The combination of LNP and hydrogel results in a delivery system known as the LNP-hydrogel composite, an emerging area of research in the field of drug delivery. To date, no research has reported the design and fabrication of an LNC-CS-iCar-p (AAm-Co-AA) hydrogel composite that could effectively deliver an antiviral drug to the lungs in addition to its advantages in terms of biological activities. Prior to the design of experiment, EFV solubility was assessed in water, labrafac lipophile 1349 and MCT oil. After that, the Design Expert Software version 13 was used to design the different experiments performed in this work. The I-optimal mixture design of experiments was performed for both LNC preparation and CS-iCar-p (AAm-Co-AA) hydrogel synthesis to study the impact of raw materials on the characteristics of these delivery systems. LNC were prepared using the phase inversion method while the free radical precipitation graft copolymerization method was used to synthesize hydrogel. In order to build polynomial models that could predict the amount of drug both LNC and CS-iCar-p (AAm-Co-AA) hydrogel can entrap, a D-optimal (custom) randomized design was performed. Moreover, various characterization techniques were used to investigate the physicochemical properties of the developed delivery systems. Thereafter, drug release studies were performed using a 1% sodium lauryl sulfate solution adjusted to either pH 4 or 7. Solubility studies revealed that EFV was more soluble in labrafac lipophile 1349 and in MCT oil than in water; therefore, given its affordability, MCT oil was used for the LNC formulation. The design of experiment carried out allowed the construction of polynomial models that could predict, on the one hand, the droplet size, the polydispersity index and the Zeta potential of LNC, which were respectively around 50nm, below 0.2 and below -33. On the other hand, the model could predict the swelling capacity of the synthesized hydrogel, which was optimised to about 30,000% (300 g of water to 1 g of hydrogel). This turned out to be influenced by the proportion of polymers, the ratio of monomers as well as the concentration of the cross-linking agent. In addition, the characterization techniques further supported the improvement of EFV solubility by highlighting its conversion into its amorphous state after encapsulation in LNC. They also confirmed successful synthesis of CS-iCar-p (AAm-co-AA) hydrogel. LNC were able to encapsulate about 87% of EFV while the synthesized CS-iCar-p (AAm-co-AA) hydrogel entrapped around 53% of EFV encapsulated in LNC. While LNC were able to release 42% and 27% of EFV after 74 hours in a 1% sodium lauryl sulfate solution (SLS) at pH 7 and pH 4 respectively, the LNC-CS-iCar-p (AAm-co-AA) hydrogel composite released about 50% and 40% of the drug after 9 days in the same release medium. Interestingly, the chemical integrity of the drug was preserved throughout the manufacturing process up to after its release, suggesting that the developed LNC-CS-iCar-p (AAm-co-AA) hydrogel composite could be used as a novel potential anticovid-19 drugs delivery system. , Thesis (MSc) -- Faculty of Science, Chemistry, 2022
- Full Text:
The effects of strategic planning and oversight on electricity service delivery outcomes in South African local municipalities: a case study of Inxuba Yethemba Municipality
- Authors: Ntintili, Noxolo Indwe
- Date: 2022-10-14
- Subjects: Strategic planning South Africa , Strategic management , Municipal services South Africa , Local government South Africa , Local service delivery , Public sector , Oversight
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/408693 , vital:70517
- Description: Poor service delivery in South Africa is a widely researched phenomenon. Yet despite the existing knowledge production efforts, in a context of a progressive developmental municipal legislative framework, South African municipalities continue to be plagued with corruption and poor service delivery performance. This thesis aims to transcend the tendency to attribute poor service delivery to a sole cause (e.g. corruption) by explaining the effects of strategic planning and oversight on several municipal service delivery processes. Therefore, this thesis introduces the Municipal Public Resource Management (MPRM) model as a strategic management tool to explain the relationship between strategic planning, the practical implementation of municipal services, and oversight processes. Specifically, thesis triangulates legislative mandates, documents published by Inxuba Yethemba Municipality (IYM) and responses from semi-structured interviews conducted with three municipal officials and three Municipal Public Accounts Committee (MPAC) councillors to uncover descriptions and explanations of service delivery processes in IYM. Findings from this thesis confirm that poor strategic planning and weak oversight contributed to poor electricity service delivery outcomes in IYM in the 2018/19 – 2019/20 financial year, and this highlights the importance of implementing strategic management for improved service delivery in South African local municipalities. , Thesis (MSocSci) -- Faculty of Humanities, Sociology, 2022
- Full Text:
- Authors: Ntintili, Noxolo Indwe
- Date: 2022-10-14
- Subjects: Strategic planning South Africa , Strategic management , Municipal services South Africa , Local government South Africa , Local service delivery , Public sector , Oversight
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/408693 , vital:70517
- Description: Poor service delivery in South Africa is a widely researched phenomenon. Yet despite the existing knowledge production efforts, in a context of a progressive developmental municipal legislative framework, South African municipalities continue to be plagued with corruption and poor service delivery performance. This thesis aims to transcend the tendency to attribute poor service delivery to a sole cause (e.g. corruption) by explaining the effects of strategic planning and oversight on several municipal service delivery processes. Therefore, this thesis introduces the Municipal Public Resource Management (MPRM) model as a strategic management tool to explain the relationship between strategic planning, the practical implementation of municipal services, and oversight processes. Specifically, thesis triangulates legislative mandates, documents published by Inxuba Yethemba Municipality (IYM) and responses from semi-structured interviews conducted with three municipal officials and three Municipal Public Accounts Committee (MPAC) councillors to uncover descriptions and explanations of service delivery processes in IYM. Findings from this thesis confirm that poor strategic planning and weak oversight contributed to poor electricity service delivery outcomes in IYM in the 2018/19 – 2019/20 financial year, and this highlights the importance of implementing strategic management for improved service delivery in South African local municipalities. , Thesis (MSocSci) -- Faculty of Humanities, Sociology, 2022
- Full Text:
English additional language student teachers’ development of oral strategic competence and confidence
- Authors: Meyers, Rozanne Elanore
- Date: 2022-04-08
- Subjects: Student teaching South Africa , Communicative competence South Africa , Oral communication , Native language and education , Language arts , Verbal ability , Multilingual education
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/263613 , vital:53643
- Description: This case study sought to understand how oral strategic and discourse competence and confidence developed in student teachers using English, their additional language, firstly as a tool of learning and secondly, as a medium of instruction in education environments. Within the broad qualitative approach an interpretive framework was adopted using multiple data collection tools. This was in order to privilege detailed accounts of participants’ experiences. Namely, unstructured interviews, drawings, observational checklists, and selfassessment questionnaires. Participants’ oral strategic and discourse competence were assessed using an observation checklist as they presented micro-teaching lessons. Additionally, participants completed a self-assessment questionnaire, reflecting on their oral competence after conducting their micro-teaching lessons. These perceptions were confirmed through a discussion of drawings that illustrated how they perceived themselves during lectures when they had to use English during oral interaction with lecturers and fellow students. Finally, unstructured interviews were conducted after participants completed their micro-teaching lessons and after participants had completed their drawings. The raw data from the four tools were analysed using a thematic approach. Main themes and categories were analysed and discussed to provide answers to the research questions. Data correlated the attitude of participants towards English and their level of oral confidence and competence. The main findings were that students were motivated to develop their oral English competence because they believed it was an important skill for teachers to possess. This motivation also proved to be a leading factor in participants’ competence despite the negative emotions they identified during spoken exchanges. Furthermore, the analysis found that collaborating with fellow students in making meaning of oral communication during lectures, increased students’ oral competence and their confidence because they were communicating in smaller groups. However, in certain situations, collaborating with students also decreased their confidence. Findings indicated that reciprocal facial expressions and the body language of those who engaged orally with the student teachers, increased their oral confidence as it served as an indication to them that they were understood. Based on these findings, recommendations are made regarding interactions during lectures for teacher training programmes in Higher Education in South Africa, for lecturers and lecturing practices, and curriculum designers in the South African Department of Education. , Thesis (MEd) -- Faculty of Education, Education, 2022
- Full Text:
- Authors: Meyers, Rozanne Elanore
- Date: 2022-04-08
- Subjects: Student teaching South Africa , Communicative competence South Africa , Oral communication , Native language and education , Language arts , Verbal ability , Multilingual education
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/263613 , vital:53643
- Description: This case study sought to understand how oral strategic and discourse competence and confidence developed in student teachers using English, their additional language, firstly as a tool of learning and secondly, as a medium of instruction in education environments. Within the broad qualitative approach an interpretive framework was adopted using multiple data collection tools. This was in order to privilege detailed accounts of participants’ experiences. Namely, unstructured interviews, drawings, observational checklists, and selfassessment questionnaires. Participants’ oral strategic and discourse competence were assessed using an observation checklist as they presented micro-teaching lessons. Additionally, participants completed a self-assessment questionnaire, reflecting on their oral competence after conducting their micro-teaching lessons. These perceptions were confirmed through a discussion of drawings that illustrated how they perceived themselves during lectures when they had to use English during oral interaction with lecturers and fellow students. Finally, unstructured interviews were conducted after participants completed their micro-teaching lessons and after participants had completed their drawings. The raw data from the four tools were analysed using a thematic approach. Main themes and categories were analysed and discussed to provide answers to the research questions. Data correlated the attitude of participants towards English and their level of oral confidence and competence. The main findings were that students were motivated to develop their oral English competence because they believed it was an important skill for teachers to possess. This motivation also proved to be a leading factor in participants’ competence despite the negative emotions they identified during spoken exchanges. Furthermore, the analysis found that collaborating with fellow students in making meaning of oral communication during lectures, increased students’ oral competence and their confidence because they were communicating in smaller groups. However, in certain situations, collaborating with students also decreased their confidence. Findings indicated that reciprocal facial expressions and the body language of those who engaged orally with the student teachers, increased their oral confidence as it served as an indication to them that they were understood. Based on these findings, recommendations are made regarding interactions during lectures for teacher training programmes in Higher Education in South Africa, for lecturers and lecturing practices, and curriculum designers in the South African Department of Education. , Thesis (MEd) -- Faculty of Education, Education, 2022
- Full Text:
Stock market volatility during times of crisis: a comparative analysis of the conditional volatilities of JSE stock indices during the 2007/08 global financial crisis and COVID-19
- Authors: Wang, Zixiao
- Date: 2022-04-06
- Subjects: Stock exchanges , Johannesburg Stock Exchange , Global Financial Crisis, 2008-2009 , COVID-19 (Disease) Economic aspects , Economic forecasting , Stock exchanges and current events , GARCH model
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/284603 , vital:56078
- Description: This research analyses the comparative behaviour of stock market volatility during two crises. The goal of this research is to determine whether assumed cyclical and defensive sectors have either retained or revealed their expected properties during both the Global Financial Crisis (GFC) and COVID-19 by analysing sectoral volatility amid these two crises. Understanding how volatility changes amid crises helps to determine whether the volatility assumptions of diversified investment portfolios for both defensive and cyclical sectors still held given the different causes of each crisis. In turn, this knowledge can assist with risk management and portfolio allocation in stock market investments. The study can also contribute towards the enhancement of financial markets’ resistance against systemic risks through portfolio diversification, and aid government decision-making targeted at tackling the weaknesses of different economic sectors especially in times of overall economic weakness. This research makes use of the GARCH model to analyse a group of daily time series that consists of eleven sectoral indices and one benchmark index, all based on the South African stock markets. These observed series are categorised into two full sample periods, one designated to the Global Financial Crisis (January 2006 to May 2009) and the other for COVID-19 (January 2018 to May 2021). These are further divided into two sets of sub-sample periods, each made up of a pre-crisis and during-crisis. Furthermore, the dummy variables representing the occurrence of structural breaks are inserted into the full sample periods’ conditional variance equations. This is aimed at capturing the asymmetrical impact of the crises themselves on all observed series. Based on the movement of volatility persistency from pre-crisis to during-crisis for both crises, the results show that, firstly, Health Care and Consumer Goods are considered defensive Sectors. Secondly, Banks, Basic Materials, Chemicals, Telecommunications, and Financials are considered cyclical Sectors. Thirdly, Automobiles & Parts, Consumer Services, and Technology are considered indeterminable Sectors due to the inconsistent behaviour of these sectors’ volatility persistency throughout the sub-sample periods of both crises. Overall, according to the average volatility persistency, the observed series for COVID-19’s full sample period are generally less volatile than those of the GFC. However, the sub-sample periods suggest that the observed series for both pre-crisis and during-crisis periods of COVID-19 are more volatile than those same sub-samples of the Global Financial Crisis. Being able to analyse the characteristics of stock market sectors is crucial for risk management and optimal portfolio allocation of stock market investments. This can be achieved through portfolio diversification by investing in a variety of stocks, both cyclical and defensive, and adjusted over time based the needs of stock market investors. Diversified portfolios do not only serve the interests of individual investors, but can also enhance the financial markets’ overall resistance against systemic risks. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2022
- Full Text:
- Authors: Wang, Zixiao
- Date: 2022-04-06
- Subjects: Stock exchanges , Johannesburg Stock Exchange , Global Financial Crisis, 2008-2009 , COVID-19 (Disease) Economic aspects , Economic forecasting , Stock exchanges and current events , GARCH model
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/284603 , vital:56078
- Description: This research analyses the comparative behaviour of stock market volatility during two crises. The goal of this research is to determine whether assumed cyclical and defensive sectors have either retained or revealed their expected properties during both the Global Financial Crisis (GFC) and COVID-19 by analysing sectoral volatility amid these two crises. Understanding how volatility changes amid crises helps to determine whether the volatility assumptions of diversified investment portfolios for both defensive and cyclical sectors still held given the different causes of each crisis. In turn, this knowledge can assist with risk management and portfolio allocation in stock market investments. The study can also contribute towards the enhancement of financial markets’ resistance against systemic risks through portfolio diversification, and aid government decision-making targeted at tackling the weaknesses of different economic sectors especially in times of overall economic weakness. This research makes use of the GARCH model to analyse a group of daily time series that consists of eleven sectoral indices and one benchmark index, all based on the South African stock markets. These observed series are categorised into two full sample periods, one designated to the Global Financial Crisis (January 2006 to May 2009) and the other for COVID-19 (January 2018 to May 2021). These are further divided into two sets of sub-sample periods, each made up of a pre-crisis and during-crisis. Furthermore, the dummy variables representing the occurrence of structural breaks are inserted into the full sample periods’ conditional variance equations. This is aimed at capturing the asymmetrical impact of the crises themselves on all observed series. Based on the movement of volatility persistency from pre-crisis to during-crisis for both crises, the results show that, firstly, Health Care and Consumer Goods are considered defensive Sectors. Secondly, Banks, Basic Materials, Chemicals, Telecommunications, and Financials are considered cyclical Sectors. Thirdly, Automobiles & Parts, Consumer Services, and Technology are considered indeterminable Sectors due to the inconsistent behaviour of these sectors’ volatility persistency throughout the sub-sample periods of both crises. Overall, according to the average volatility persistency, the observed series for COVID-19’s full sample period are generally less volatile than those of the GFC. However, the sub-sample periods suggest that the observed series for both pre-crisis and during-crisis periods of COVID-19 are more volatile than those same sub-samples of the Global Financial Crisis. Being able to analyse the characteristics of stock market sectors is crucial for risk management and optimal portfolio allocation of stock market investments. This can be achieved through portfolio diversification by investing in a variety of stocks, both cyclical and defensive, and adjusted over time based the needs of stock market investors. Diversified portfolios do not only serve the interests of individual investors, but can also enhance the financial markets’ overall resistance against systemic risks. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2022
- Full Text:
Educating learners with special educational needs in special schools: an interpretative phenomenological study of teachers’ experiences
- Authors: Matebese, Sibongile
- Date: 2021-10-29
- Subjects: Children with disabilities Education South Africa , South Africa. Department of Education , Inclusive education South Africa , Special education teachers South Africa , Special education teachers South Africa Interviews , Phenomenological psychology
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192270 , vital:45211
- Description: In 2001, the Department of Education introduced a policy known as White Paper 6: Special Needs Education: Building an Inclusive Education and Training System. This policy was a response to the worldwide call for inclusive education. It aimed to ensure that all learners with special educational needs (LSEN) and who experience barriers to learning are accommodated and taught in mainstream schooling contexts. Implementation of this policy in South Africa has been a challenge, and special schools continue to exist. While research has explored the experiences of teachers who teach LSEN, such studies have focused on teacher experiences in mainstream schools. A few international and South African studies have explored teacher experiences of teaching LSEN in special schools; however, these explore specific aspects of teacher experiences and are outdated. Based on this premise and drawing on a phenomenological approach, this study sought to explore and understand the experiences of teachers who teach LSEN in special schools. Using the semi-structured interview, eight teachers teaching in special schools in a city in the Eastern Cape were recruited and interviewed. Five superordinate themes emerged from the shared experiences, namely, ‘personal commitment and the need for a balance’, ‘recognising the learner at the centre’, ‘the importance of a holistic approach’, ‘the ups and downs of teaching LSEN’, and ‘support is available but limited’. Within these themes, the teachers experienced teaching LSEN as involving more than teaching, as a role guided by the learner, as collaborative, associated with positive experiences and challenges, including an endeavour that they are adequately supported in but simultaneously require more support for. In reflecting on this analysis, this study argues that special schools are necessary; teaching LSEN in special schools is important to teachers, and they feel a responsibility for it. Recommendations for future research include repeating the present study with a different population and methodology, interviewing parents of LSEN and LSEN themselves to gain further insights into special schooling. The study makes key recommendations for special needs education to help ensure that such an educational system is sustained as inclusion is a long way from being realised. , Thesis (MA) -- Faculty of Humanities, Psychology, 2021
- Full Text:
- Authors: Matebese, Sibongile
- Date: 2021-10-29
- Subjects: Children with disabilities Education South Africa , South Africa. Department of Education , Inclusive education South Africa , Special education teachers South Africa , Special education teachers South Africa Interviews , Phenomenological psychology
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192270 , vital:45211
- Description: In 2001, the Department of Education introduced a policy known as White Paper 6: Special Needs Education: Building an Inclusive Education and Training System. This policy was a response to the worldwide call for inclusive education. It aimed to ensure that all learners with special educational needs (LSEN) and who experience barriers to learning are accommodated and taught in mainstream schooling contexts. Implementation of this policy in South Africa has been a challenge, and special schools continue to exist. While research has explored the experiences of teachers who teach LSEN, such studies have focused on teacher experiences in mainstream schools. A few international and South African studies have explored teacher experiences of teaching LSEN in special schools; however, these explore specific aspects of teacher experiences and are outdated. Based on this premise and drawing on a phenomenological approach, this study sought to explore and understand the experiences of teachers who teach LSEN in special schools. Using the semi-structured interview, eight teachers teaching in special schools in a city in the Eastern Cape were recruited and interviewed. Five superordinate themes emerged from the shared experiences, namely, ‘personal commitment and the need for a balance’, ‘recognising the learner at the centre’, ‘the importance of a holistic approach’, ‘the ups and downs of teaching LSEN’, and ‘support is available but limited’. Within these themes, the teachers experienced teaching LSEN as involving more than teaching, as a role guided by the learner, as collaborative, associated with positive experiences and challenges, including an endeavour that they are adequately supported in but simultaneously require more support for. In reflecting on this analysis, this study argues that special schools are necessary; teaching LSEN in special schools is important to teachers, and they feel a responsibility for it. Recommendations for future research include repeating the present study with a different population and methodology, interviewing parents of LSEN and LSEN themselves to gain further insights into special schooling. The study makes key recommendations for special needs education to help ensure that such an educational system is sustained as inclusion is a long way from being realised. , Thesis (MA) -- Faculty of Humanities, Psychology, 2021
- Full Text:
Investigation of sediment buffering function of the Gatberg Floodplain Wetland in the upper Tsitsa River Catchment, South Africa
- Pakati, Sibuyisele Sweetness
- Authors: Pakati, Sibuyisele Sweetness
- Date: 2021-10
- Subjects: Sedimentation and deposition South Africa Eastern Cape , Sediment transport South Africa Eastern Cape , Floodplain morphology South Africa Eastern Cape , Wetlands South Africa Eastern Cape , Suspended sediments South Africa Eastern Cape , Floods South Africa Eastern Cape , Fluvial geomorphology South Africa Eastern Cape , Floodplain plants South Africa Eastern Cape , Inundation depth
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190792 , vital:45028
- Description: Floodplain wetlands are important components of river systems that provide various ecosystem services such as sediment buffering. These wide and often expansive storage areas have a substantial impact on downstream water quality by trapping sediment and storing ‘contaminants’ adhered to sediment thus improving water quality. The planned construction of the Ntabelanga and Lalini Dams in the Tsitsa River Catchment has been proposed; however, due to the steep landscapes and erodible soils, this promotes high erosion rates that can potentially reduce the lifespan of the proposed dams. The existing wetlands in the Tsitsa River Catchment have therefore been identified as key sediment buffers that can reduce sediment transport, but the effectiveness of these buffers is poorly researched. This study attempts to investigate the current sediment buffering function of the Gatberg Floodplain Wetland over one wet season (August 2019 to August 2020). Time integrated samplers were installed above and below the wetland to determine relative sediment volume and character coming in and out of the wetland. Five transects were surveyed across the wetland width to evaluate the topography and vegetation characteristics. Surface sediment samples on the floodplain were taken at key morphological features along each transect and along the river longitudinal profile to determine organic content, particle size, and type of stored sediment. Astro turf mats were deployed on targeted transects and on key floodplain features to determine sediment accumulation rates. Field measurements of vegetation parameters (height, density, and stem diameter) were taken to calculate vegetation-induced hydraulic roughness to understand possible sedimentation feedbacks. The relative sediment volume coming into the wetland was greater than that leaving the wetland. This implies that some of the sediment is buffered within the wetland. An approximate proportion of 73% trapping efficiency of the incoming sediment was buffered within the floodplain wetland during the wet season. This accumulated approximately 4 tons within the wetland over the monitoring frame. Bed particle size in the longitudinal profile increased with distance downstream, this was due to localized tributary and hillslope inputs. Inundation depth varied across the floodplain wetland with deeper inundation depths at the head of the wetland than at the bottom; where particle size was larger with an increase in water level depth. This may be linked to both high stream velocities and variability of the floodplain topography. However, the observed trends were inconclusive and uncertain. Stronger correlations with particle size were shown by vegetation roughness (b* = 0.41) and distance from the channel (b* = -0.38). Flood benches and banks had a coarser D50 particle size than back swamps and oxbows. Coarser sediment in flood benches are associated with proximity to the sediment-laden water that experiences abrupt flow velocity changes, while finer material in oxbows are due to minimal flow velocities which reduce with distance from the channel. Finer particles remain in suspension and are carried aloft for longer periods at very low velocities. Therefore, particle size decreased with distance from the channel due to longer travel distances and high surface area relative to weight. Further results showed that finer surface sediment particle size was associated with high vegetation roughness whilst coarser material was associated with low roughness. This was due to vegetation geometry and type or changes in flow velocity and energy. Grassy vegetation induced finer particle size than shrubby vegetation that has a greater line spacing. Furthermore, vegetation roughness varied over the wet season; roughness was highest in late summer and low in early summer. Low roughness was due to fire occurrence in the study area which resulted in a decrease in biomass. Increasing vegetation roughness can be due to increased flood events, and the introduction of non-perennial species; which can increase sediment accumulation rates. Although studies have shown that vegetation density is the most essential factor affecting flow resistance and sedimentation processes; vegetation height and stem diameter for this study area seem to contrast these observations and rather may be the most significant contributing factors in sedimentation. This concluded that vegetation density may not always be the most essential component in sedimentation processes. Sediment particle size was inversely proportional to organic content; finer particle size are more cohesive and more capable of carrying organics. Regions further away from the channel such as oxbows with stable moisture conditions favour plant growth and soil formation thus are susceptible to high organic content. Flood benches are closer to the channel, thus have coarser material and fluctuating moisture conditions that have unstable high water flow velocities. High sediment accumulation rates on flood benches and oxbows is due to high connectivity to sediment-laden water and high hydroperiods or high residence time for sediment accumulation in oxbows. Sediment accumulation rate was shown to be a function of particle size itself (b* = 0.67) rather than the expected vegetation roughness. Although a true representation of sediment accumulation rates in the Gatberg Wetland was limited by the disturbance of astro turf mats by animals and possibly by high flooding events; the wetland can be regarded as a good sediment buffer as some sediment was stored (e.g. up to 48,04 kg/m2 in flood benches) within the wetland over the monitoring period. , Thesis (MSc) -- Faculty of Science, Geography, 2021
- Full Text:
- Authors: Pakati, Sibuyisele Sweetness
- Date: 2021-10
- Subjects: Sedimentation and deposition South Africa Eastern Cape , Sediment transport South Africa Eastern Cape , Floodplain morphology South Africa Eastern Cape , Wetlands South Africa Eastern Cape , Suspended sediments South Africa Eastern Cape , Floods South Africa Eastern Cape , Fluvial geomorphology South Africa Eastern Cape , Floodplain plants South Africa Eastern Cape , Inundation depth
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190792 , vital:45028
- Description: Floodplain wetlands are important components of river systems that provide various ecosystem services such as sediment buffering. These wide and often expansive storage areas have a substantial impact on downstream water quality by trapping sediment and storing ‘contaminants’ adhered to sediment thus improving water quality. The planned construction of the Ntabelanga and Lalini Dams in the Tsitsa River Catchment has been proposed; however, due to the steep landscapes and erodible soils, this promotes high erosion rates that can potentially reduce the lifespan of the proposed dams. The existing wetlands in the Tsitsa River Catchment have therefore been identified as key sediment buffers that can reduce sediment transport, but the effectiveness of these buffers is poorly researched. This study attempts to investigate the current sediment buffering function of the Gatberg Floodplain Wetland over one wet season (August 2019 to August 2020). Time integrated samplers were installed above and below the wetland to determine relative sediment volume and character coming in and out of the wetland. Five transects were surveyed across the wetland width to evaluate the topography and vegetation characteristics. Surface sediment samples on the floodplain were taken at key morphological features along each transect and along the river longitudinal profile to determine organic content, particle size, and type of stored sediment. Astro turf mats were deployed on targeted transects and on key floodplain features to determine sediment accumulation rates. Field measurements of vegetation parameters (height, density, and stem diameter) were taken to calculate vegetation-induced hydraulic roughness to understand possible sedimentation feedbacks. The relative sediment volume coming into the wetland was greater than that leaving the wetland. This implies that some of the sediment is buffered within the wetland. An approximate proportion of 73% trapping efficiency of the incoming sediment was buffered within the floodplain wetland during the wet season. This accumulated approximately 4 tons within the wetland over the monitoring frame. Bed particle size in the longitudinal profile increased with distance downstream, this was due to localized tributary and hillslope inputs. Inundation depth varied across the floodplain wetland with deeper inundation depths at the head of the wetland than at the bottom; where particle size was larger with an increase in water level depth. This may be linked to both high stream velocities and variability of the floodplain topography. However, the observed trends were inconclusive and uncertain. Stronger correlations with particle size were shown by vegetation roughness (b* = 0.41) and distance from the channel (b* = -0.38). Flood benches and banks had a coarser D50 particle size than back swamps and oxbows. Coarser sediment in flood benches are associated with proximity to the sediment-laden water that experiences abrupt flow velocity changes, while finer material in oxbows are due to minimal flow velocities which reduce with distance from the channel. Finer particles remain in suspension and are carried aloft for longer periods at very low velocities. Therefore, particle size decreased with distance from the channel due to longer travel distances and high surface area relative to weight. Further results showed that finer surface sediment particle size was associated with high vegetation roughness whilst coarser material was associated with low roughness. This was due to vegetation geometry and type or changes in flow velocity and energy. Grassy vegetation induced finer particle size than shrubby vegetation that has a greater line spacing. Furthermore, vegetation roughness varied over the wet season; roughness was highest in late summer and low in early summer. Low roughness was due to fire occurrence in the study area which resulted in a decrease in biomass. Increasing vegetation roughness can be due to increased flood events, and the introduction of non-perennial species; which can increase sediment accumulation rates. Although studies have shown that vegetation density is the most essential factor affecting flow resistance and sedimentation processes; vegetation height and stem diameter for this study area seem to contrast these observations and rather may be the most significant contributing factors in sedimentation. This concluded that vegetation density may not always be the most essential component in sedimentation processes. Sediment particle size was inversely proportional to organic content; finer particle size are more cohesive and more capable of carrying organics. Regions further away from the channel such as oxbows with stable moisture conditions favour plant growth and soil formation thus are susceptible to high organic content. Flood benches are closer to the channel, thus have coarser material and fluctuating moisture conditions that have unstable high water flow velocities. High sediment accumulation rates on flood benches and oxbows is due to high connectivity to sediment-laden water and high hydroperiods or high residence time for sediment accumulation in oxbows. Sediment accumulation rate was shown to be a function of particle size itself (b* = 0.67) rather than the expected vegetation roughness. Although a true representation of sediment accumulation rates in the Gatberg Wetland was limited by the disturbance of astro turf mats by animals and possibly by high flooding events; the wetland can be regarded as a good sediment buffer as some sediment was stored (e.g. up to 48,04 kg/m2 in flood benches) within the wetland over the monitoring period. , Thesis (MSc) -- Faculty of Science, Geography, 2021
- Full Text:
In silico identification of selective novel hits against the active site of wild type mycobacterium tuberculosis pyrazinamidase and its mutants
- Authors: Gowo, Prudence
- Date: 2021-04
- Subjects: Mycobacterium tuberculosis , Pyrazinamide , Multidrug resistance , Antitubercular agents , Molecular dynamics , Hydrogen bonding , Ligand binding (Biochemistry) , Dynamic Residue Network
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/178007 , vital:42898
- Description: The World Health Organization declared Tuberculosis a global health emergency and has set a goal to eradicate it by 2035. However, effective treatment and control of the disease is being hindered by the emerging Multi-Drug Resistant and Extensively Drug Resistant strains on the most effective first line prodrug, Pyrazinamide (PZA). Studies have shown that the main cause of PZA resistance is due to mutations in the pncA gene that codes for the target protein Pyrazinamidase (PZase). Therefore, this study aimed to identify novel drug compounds that bind to the active site of wild type PZase and study the dynamics of these potential anti-TB drugs in the mutant systems of PZase. This approach will aid in identifying drugs that may be repurposed for TB therapy and/or designed to counteract PZA resistance. This was achieved by screening 2089 DrugBank compounds against the whole wild type (WT) PZase protein in molecular docking using AutoDOCK4.2. Compound screening based on docking binding energy, hydrogen bonds, molecular weight and active site proximity identified 47 compounds meeting all the set selection criteria. The stability of these compounds were analysed in Molecular Dynamic (MD) simulations and were further studied in PZase mutant systems of A3P, A134V, A146V, D8G, D49A, D49G, D63G, H51P, H137R, L85R, L116R, Q10P, R140S, T61P, V139M and Y103S. Generally, mutant-ligand systems displayed little deviation from the WT systems. The compound systems remained compact, with less fluctuations and more hydrogen bond interactions throughout the simulation (DB00255, DB00655, DB00672, DB00782, DB00977, DB01196, DB04573, DB06414, DB08981, DB11181, DB11760, DB13867, DB13952). From this research study, potential drugs that may be repurposed for TB therapy were identified. Majority of these drugs are currently used in the treatment of hypertension, menopause disorders and inflammation. To further understand the mutant-ligand dynamic systems, calculations such as Dynamic Residue Network (DRN) may be done. Also, the bioactivity of these drugs on Mycobacterium tuberculosis may be studied in wet laboratory, to understand their clinical impart in vivo experiments. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2021
- Full Text:
- Authors: Gowo, Prudence
- Date: 2021-04
- Subjects: Mycobacterium tuberculosis , Pyrazinamide , Multidrug resistance , Antitubercular agents , Molecular dynamics , Hydrogen bonding , Ligand binding (Biochemistry) , Dynamic Residue Network
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/178007 , vital:42898
- Description: The World Health Organization declared Tuberculosis a global health emergency and has set a goal to eradicate it by 2035. However, effective treatment and control of the disease is being hindered by the emerging Multi-Drug Resistant and Extensively Drug Resistant strains on the most effective first line prodrug, Pyrazinamide (PZA). Studies have shown that the main cause of PZA resistance is due to mutations in the pncA gene that codes for the target protein Pyrazinamidase (PZase). Therefore, this study aimed to identify novel drug compounds that bind to the active site of wild type PZase and study the dynamics of these potential anti-TB drugs in the mutant systems of PZase. This approach will aid in identifying drugs that may be repurposed for TB therapy and/or designed to counteract PZA resistance. This was achieved by screening 2089 DrugBank compounds against the whole wild type (WT) PZase protein in molecular docking using AutoDOCK4.2. Compound screening based on docking binding energy, hydrogen bonds, molecular weight and active site proximity identified 47 compounds meeting all the set selection criteria. The stability of these compounds were analysed in Molecular Dynamic (MD) simulations and were further studied in PZase mutant systems of A3P, A134V, A146V, D8G, D49A, D49G, D63G, H51P, H137R, L85R, L116R, Q10P, R140S, T61P, V139M and Y103S. Generally, mutant-ligand systems displayed little deviation from the WT systems. The compound systems remained compact, with less fluctuations and more hydrogen bond interactions throughout the simulation (DB00255, DB00655, DB00672, DB00782, DB00977, DB01196, DB04573, DB06414, DB08981, DB11181, DB11760, DB13867, DB13952). From this research study, potential drugs that may be repurposed for TB therapy were identified. Majority of these drugs are currently used in the treatment of hypertension, menopause disorders and inflammation. To further understand the mutant-ligand dynamic systems, calculations such as Dynamic Residue Network (DRN) may be done. Also, the bioactivity of these drugs on Mycobacterium tuberculosis may be studied in wet laboratory, to understand their clinical impart in vivo experiments. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2021
- Full Text:
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