High-intensity Interval Training utilising a standardised versus customised training programme among endurance trained male cyclists
- Authors: Salzwedel, Jarred Wayne
- Date: 2020
- Subjects: Cycling South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/46423 , vital:39596
- Description: The primary aim of this study was to compare the effect of a standardised versus customised high-intensity interval training programmeon performance indicators of endurance trained male cyclists utilising a standardised method of prescribing intervals in comparison to a customised method of prescribing intervals based on training feedback. The study was exploratory and quasi-experimental in nature and utilized a quantitative approach. A quasi-experimental, pretest-postestcontrol group study design was used. A total number of 22 participants that met the inclusion criteria were included in the study by means of purposive sampling. The participants were subdivided into an experimental group (n=11) and a control group (n=11)by means of random stratification in order to ensure performance equality between the two groups. The experimental group completed a High-Intensity Interval Training (HIIT) block of 28 days (four weeks) with three weeks of interval-based sessions and one recovery week ending off the block. The programmeutilised the same “anaerobic” type intervals (10 x 30 seconds at 170% PPO with 4 minutes 30 seconds recovery) as the control group, performed twice per week for three consecutive weeks. The Lamberts and Lambert submaximal cycling test (LSCT) was used to determine whether a participant in the experimental group could start his HIIT session on a particular day.Participants were notallowed to start their HIIT session if twoor more of the set criteria weremet.If the participants did not qualify to participate in a HIIT session they were required to perform a low intensity training session in the same venue. Differences between the pre-and post-test showed statistically non-significant improvements (p>0.05) from pre-to post-test for both the experimental and control groups in respect of the physiological variables measured (gas exchange threshold, respiratory compensation point, maximal oxygen consumption). The experimental group did however show more positive, but statistically non-significantimprovements in peak power output. The findings of this study therefore showed that no significant within group nor between group improvements were achieved utilizing a standised versus customised HIIT training programme over the four-week study period. The findings do however suggest that the LSCT may have merit in prescribing HIIT sessions in trained athletesas suggested by the improvements of the experimental group’s peak power output.
- Full Text:
- Date Issued: 2020
- Authors: Salzwedel, Jarred Wayne
- Date: 2020
- Subjects: Cycling South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/46423 , vital:39596
- Description: The primary aim of this study was to compare the effect of a standardised versus customised high-intensity interval training programmeon performance indicators of endurance trained male cyclists utilising a standardised method of prescribing intervals in comparison to a customised method of prescribing intervals based on training feedback. The study was exploratory and quasi-experimental in nature and utilized a quantitative approach. A quasi-experimental, pretest-postestcontrol group study design was used. A total number of 22 participants that met the inclusion criteria were included in the study by means of purposive sampling. The participants were subdivided into an experimental group (n=11) and a control group (n=11)by means of random stratification in order to ensure performance equality between the two groups. The experimental group completed a High-Intensity Interval Training (HIIT) block of 28 days (four weeks) with three weeks of interval-based sessions and one recovery week ending off the block. The programmeutilised the same “anaerobic” type intervals (10 x 30 seconds at 170% PPO with 4 minutes 30 seconds recovery) as the control group, performed twice per week for three consecutive weeks. The Lamberts and Lambert submaximal cycling test (LSCT) was used to determine whether a participant in the experimental group could start his HIIT session on a particular day.Participants were notallowed to start their HIIT session if twoor more of the set criteria weremet.If the participants did not qualify to participate in a HIIT session they were required to perform a low intensity training session in the same venue. Differences between the pre-and post-test showed statistically non-significant improvements (p>0.05) from pre-to post-test for both the experimental and control groups in respect of the physiological variables measured (gas exchange threshold, respiratory compensation point, maximal oxygen consumption). The experimental group did however show more positive, but statistically non-significantimprovements in peak power output. The findings of this study therefore showed that no significant within group nor between group improvements were achieved utilizing a standised versus customised HIIT training programme over the four-week study period. The findings do however suggest that the LSCT may have merit in prescribing HIIT sessions in trained athletesas suggested by the improvements of the experimental group’s peak power output.
- Full Text:
- Date Issued: 2020
Hope in a small town
- Authors: Ngubelanga, Xolisa
- Date: 2020
- Subjects: South African fiction (English) -- 21st century , South African fiction (English) -- History and criticism , Short stories, South African (English) -- 21st century
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/145089 , vital:38407
- Description: Writing has always experienced as the elite relative in the family of arts, especially among African artists and art consumers. Somehow writing has in past and to a great extent still is in the present been referred more than song, storytelling and dancing. Interrogating the past of colonization of African narratives I could point that this is the case because African expression had always packaged in a ‘come see the Africans are dancing, singing or storytelling. Listen to their clicks.’ Writing, however, could only be executed by those Africans of white assimilation with higher social status and missionary education. Among amaXhosa, the disparity of socially lesser African arts and that of the educated has been termed the narrative of Amaqaba and Amagqobhoka. Amaqaba being those whose stories have taken longer to be documented in modern means of writing but have been enriched through years of live telling. Amagqobhoka on the other hand who easily documented their narrative after having been trained in writing have enjoined the audience of readers and access into literary space longer.
- Full Text:
- Date Issued: 2020
- Authors: Ngubelanga, Xolisa
- Date: 2020
- Subjects: South African fiction (English) -- 21st century , South African fiction (English) -- History and criticism , Short stories, South African (English) -- 21st century
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/145089 , vital:38407
- Description: Writing has always experienced as the elite relative in the family of arts, especially among African artists and art consumers. Somehow writing has in past and to a great extent still is in the present been referred more than song, storytelling and dancing. Interrogating the past of colonization of African narratives I could point that this is the case because African expression had always packaged in a ‘come see the Africans are dancing, singing or storytelling. Listen to their clicks.’ Writing, however, could only be executed by those Africans of white assimilation with higher social status and missionary education. Among amaXhosa, the disparity of socially lesser African arts and that of the educated has been termed the narrative of Amaqaba and Amagqobhoka. Amaqaba being those whose stories have taken longer to be documented in modern means of writing but have been enriched through years of live telling. Amagqobhoka on the other hand who easily documented their narrative after having been trained in writing have enjoined the audience of readers and access into literary space longer.
- Full Text:
- Date Issued: 2020
Household and business recycling programs as green strategies for waste management in East London, South Africa
- Authors: Fotoyi, Tenjiwe
- Date: 2020
- Subjects: Refuse and refuse disposal
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/18687 , vital:42706
- Description: Municipalities in South Africa generate enormous waste which is disposed of in a few landfill sites which, in turn, have a limited life span. Household recycling is one important mechanism that can be used to reduce the amount of waste that reaches overfilled landfill sites. The city of East London is running out of land to dispose waste, and their landfill sites, in particular, are filing up fast. Most of the waste generated, is recyclable, however recycling in the city remains fragmented, and is moving very slowly. This is because of the lack of a co-ordinated approach between the BCMM and the local communities, across the many suburbs of East London. Considering that urban areas have limited space, effective and efficient use of current landfills is of strategic importance. This research therefore will examine ways of improving recycling in East London, addressing challenges facing current recycling. Data for this study was collected from the random administration of 100 questionnaires on different categories of respondents in the study area. The study revealed that by the introduction of the “Hand-on-waste” programme, the waste management personnel have taken the first step towards household waste recycling. However, the level of awareness and knowledge of the public on domestic recycling was quite poor, if residents are given the necessary encouragement, motivation and recycling infrastructure waste minimisation would be achieved
- Full Text:
- Date Issued: 2020
- Authors: Fotoyi, Tenjiwe
- Date: 2020
- Subjects: Refuse and refuse disposal
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/18687 , vital:42706
- Description: Municipalities in South Africa generate enormous waste which is disposed of in a few landfill sites which, in turn, have a limited life span. Household recycling is one important mechanism that can be used to reduce the amount of waste that reaches overfilled landfill sites. The city of East London is running out of land to dispose waste, and their landfill sites, in particular, are filing up fast. Most of the waste generated, is recyclable, however recycling in the city remains fragmented, and is moving very slowly. This is because of the lack of a co-ordinated approach between the BCMM and the local communities, across the many suburbs of East London. Considering that urban areas have limited space, effective and efficient use of current landfills is of strategic importance. This research therefore will examine ways of improving recycling in East London, addressing challenges facing current recycling. Data for this study was collected from the random administration of 100 questionnaires on different categories of respondents in the study area. The study revealed that by the introduction of the “Hand-on-waste” programme, the waste management personnel have taken the first step towards household waste recycling. However, the level of awareness and knowledge of the public on domestic recycling was quite poor, if residents are given the necessary encouragement, motivation and recycling infrastructure waste minimisation would be achieved
- Full Text:
- Date Issued: 2020
How relational and strategic leadership shape organizational culture
- Lebusa, Libuseng Mampolokeng
- Authors: Lebusa, Libuseng Mampolokeng
- Date: 2020
- Subjects: SOS Quthing Children's Village -- Management , Corporate culture , Corporate culture -- Lesotho -- Quthing , Leadership -- Lesotho -- Quthing , Nonprofit organizations -- Lesotho -- Quthing
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/166070 , vital:41326
- Description: The study aims at analysing how relational and strategic leadership shapes the culture of an organization, using as a case study the SOS Children’s Village Lesotho in Quthing District. As an International Federation, SOS Children’s Village espouses four values, namely Courage, Trust, Commitment, and Accountability. The case was selected because SOS Children’s Village’s performance in Lesotho has been outstanding, due to employee commitment in the organization. The review of the literature drew upon three theories: the theory of organizational culture by Schein (2010), which shed a light on cultural embedding mechanisms, the relational leadership components of Komives, S, Lucas, N, and McMahon, T (1998), and the strategic leadership roles of Ireland and Hitt (1999). This study adopted a deductive qualitative research method, where structured interviews supplemented with documents were used to collect data. Thematic analysis and pattern matching analysed the data with the aid of a pre-developed codebook that identify theoretical codes and themes in the data. The findings confirmed that with the use of cultural embedding mechanisms, relational and strategic leadership shaped the culture of commitment. The main characteristics of the culture of the commitment of SOS Quthing are punctuality, teamwork, and individual initiative. Relational and strategic leadership behaviours helped to create a culture of commitment through the fair and equitable allocation of resources, the inclusion of employees in decision making, having an orientation program for new employees, giving rewards and recognition, holding regular meetings, supervision, utilizing the online collaboration system and the systematic development of human capital. The literature supported the study results. The study acknowledges the limitations and delimitations of the research. The study’s contribution was in identifying how leadership behaviours operate through cultural embedding mechanisms to "identify" creates a culture of commitment. In conclusion, managerial recommendations were made for SOS to strengthen their leadership behaviours further and further research recommendations.
- Full Text:
- Date Issued: 2020
- Authors: Lebusa, Libuseng Mampolokeng
- Date: 2020
- Subjects: SOS Quthing Children's Village -- Management , Corporate culture , Corporate culture -- Lesotho -- Quthing , Leadership -- Lesotho -- Quthing , Nonprofit organizations -- Lesotho -- Quthing
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/166070 , vital:41326
- Description: The study aims at analysing how relational and strategic leadership shapes the culture of an organization, using as a case study the SOS Children’s Village Lesotho in Quthing District. As an International Federation, SOS Children’s Village espouses four values, namely Courage, Trust, Commitment, and Accountability. The case was selected because SOS Children’s Village’s performance in Lesotho has been outstanding, due to employee commitment in the organization. The review of the literature drew upon three theories: the theory of organizational culture by Schein (2010), which shed a light on cultural embedding mechanisms, the relational leadership components of Komives, S, Lucas, N, and McMahon, T (1998), and the strategic leadership roles of Ireland and Hitt (1999). This study adopted a deductive qualitative research method, where structured interviews supplemented with documents were used to collect data. Thematic analysis and pattern matching analysed the data with the aid of a pre-developed codebook that identify theoretical codes and themes in the data. The findings confirmed that with the use of cultural embedding mechanisms, relational and strategic leadership shaped the culture of commitment. The main characteristics of the culture of the commitment of SOS Quthing are punctuality, teamwork, and individual initiative. Relational and strategic leadership behaviours helped to create a culture of commitment through the fair and equitable allocation of resources, the inclusion of employees in decision making, having an orientation program for new employees, giving rewards and recognition, holding regular meetings, supervision, utilizing the online collaboration system and the systematic development of human capital. The literature supported the study results. The study acknowledges the limitations and delimitations of the research. The study’s contribution was in identifying how leadership behaviours operate through cultural embedding mechanisms to "identify" creates a culture of commitment. In conclusion, managerial recommendations were made for SOS to strengthen their leadership behaviours further and further research recommendations.
- Full Text:
- Date Issued: 2020
Human capital Development and Economic Growth: A cross country study
- Authors: Sokanti, Thembalethu
- Date: 2020
- Subjects: Economic development Human capital
- Language: English
- Type: Thesis , Masters , MCom (Economics)
- Identifier: http://hdl.handle.net/10353/18985 , vital:43005
- Description: The study examined the impact of human capital development on economic growth for 129 countries comprising of developed and developing countries. The primary focus of the study is on examining the contribution of human capital index components on economic growth for the period 2014 to 2017. The panel data model was employed in the study. Firstly, the hausman test was used to determine the suitable method between fixed and random effects. The fixed effects model was selected as the best panel econometric technique to be used in the study. The empirical results showed that there is a positive and statistically significant relationship between human capital index components (capacity, development, deployment and know how) and economic growth. The study also found that these components of human capital index have more impact on economic growth when they are interacted together based on theories of human capital and economic growth. Capacity and development are found to be the best contributors to economic growth for all the regions; thus, the study recommends that for economic growth to be increased, countries should invest more of their funds on capacity and development sub- indexes of human capital index. Exchange rates and inflation are found to have a negative relationship with the economic growth, while interest rates are found to have a positive and statistical relationship with the economic growth. The study also found out that there is a regional effect associated with human capital development, with European region being the best contributor to GDP. The components of human capital index also found to be important for all regions to invest on to improve economic performance. Deployment is found not to be significant is Sub-Saharan Africa. The existence of income group effect is found with developed countries performing much better compared to developing countries. The study also recommended that countries should invest more of their wealth in human capital development components such as education and health to enhance their economic growth
- Full Text:
- Date Issued: 2020
- Authors: Sokanti, Thembalethu
- Date: 2020
- Subjects: Economic development Human capital
- Language: English
- Type: Thesis , Masters , MCom (Economics)
- Identifier: http://hdl.handle.net/10353/18985 , vital:43005
- Description: The study examined the impact of human capital development on economic growth for 129 countries comprising of developed and developing countries. The primary focus of the study is on examining the contribution of human capital index components on economic growth for the period 2014 to 2017. The panel data model was employed in the study. Firstly, the hausman test was used to determine the suitable method between fixed and random effects. The fixed effects model was selected as the best panel econometric technique to be used in the study. The empirical results showed that there is a positive and statistically significant relationship between human capital index components (capacity, development, deployment and know how) and economic growth. The study also found that these components of human capital index have more impact on economic growth when they are interacted together based on theories of human capital and economic growth. Capacity and development are found to be the best contributors to economic growth for all the regions; thus, the study recommends that for economic growth to be increased, countries should invest more of their funds on capacity and development sub- indexes of human capital index. Exchange rates and inflation are found to have a negative relationship with the economic growth, while interest rates are found to have a positive and statistical relationship with the economic growth. The study also found out that there is a regional effect associated with human capital development, with European region being the best contributor to GDP. The components of human capital index also found to be important for all regions to invest on to improve economic performance. Deployment is found not to be significant is Sub-Saharan Africa. The existence of income group effect is found with developed countries performing much better compared to developing countries. The study also recommended that countries should invest more of their wealth in human capital development components such as education and health to enhance their economic growth
- Full Text:
- Date Issued: 2020
Hydrogeochemistry of shallow karoo basin aquifers in the border-kei region flanking the Indian Ocean, Eastern Cape, South Africa
- Authors: Jeppesen, Keegan
- Date: 2020
- Subjects: Water chemistry -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/48401 , vital:40856
- Description: As the potential for shale gas exploitation becomes a real possibility across parts of the Karoo in South Africa, and groundwater is one of the systems that could become heavily stressed if the shale gas industry becomes operational, it is important therefore to gain a better understanding into the hydrogeochemical systems and processes that occur within the Karoo Basin. Groundwater systems are very complex and are heavily relied upon in many areas across the Karoo that are surface water deficient. Groundwater is used domestically, for irrigation and livestock as well as in industry. A hydrogeochemical baseline investigation was undertaken in the shallow Karoo Basin aquifers (< 100 m) of the Border-Kei region with in the Eastern Cape of South Africa, which flanks the Indian Ocean. Since it has been suggested that seawater might be used as a potential fracking fluid, it is important to also establish baseline data linked to potential seawater salinisation in the coastal aquifers. This was achieved by sampling water from both 35 production and 3 non-production boreholes (by making use of a bailer and discrete interval sampler). Water from all 38 samples was analysed for major anions and cations, trace elements as well as for δ 18O and δ 2H stable isotopes. Results indicate that the majority of the groundwater in the study area falls within acceptable limits for domestic use, and although slightly saline, is exploitable for other uses as well. It was also found that dolerite dykes that have intruded into the Karoo Basin sediments have slight effects on the groundwater chemistry, but that these effects are also masked by the water-rock interactions occurring with the aquifer. It was also determined with major ions and stable isotopes that although the coastal aquifers do have saline signatures (EC > 200 mS/m) this is not due to salinisation via seawater intrusion. It is instead postulated that the salinity arises from marine aerosols that have introduced NaCl onto the soil layer, and which then leaches into the groundwater system through precipitation or irrigation. In the event of shale gas extraction through fracking or the expansion of rural and urban centres, this project serves as a preliminary hydrogeochemical baseline before any of these processes proceed within the Karoo Basin.
- Full Text:
- Date Issued: 2020
- Authors: Jeppesen, Keegan
- Date: 2020
- Subjects: Water chemistry -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/48401 , vital:40856
- Description: As the potential for shale gas exploitation becomes a real possibility across parts of the Karoo in South Africa, and groundwater is one of the systems that could become heavily stressed if the shale gas industry becomes operational, it is important therefore to gain a better understanding into the hydrogeochemical systems and processes that occur within the Karoo Basin. Groundwater systems are very complex and are heavily relied upon in many areas across the Karoo that are surface water deficient. Groundwater is used domestically, for irrigation and livestock as well as in industry. A hydrogeochemical baseline investigation was undertaken in the shallow Karoo Basin aquifers (< 100 m) of the Border-Kei region with in the Eastern Cape of South Africa, which flanks the Indian Ocean. Since it has been suggested that seawater might be used as a potential fracking fluid, it is important to also establish baseline data linked to potential seawater salinisation in the coastal aquifers. This was achieved by sampling water from both 35 production and 3 non-production boreholes (by making use of a bailer and discrete interval sampler). Water from all 38 samples was analysed for major anions and cations, trace elements as well as for δ 18O and δ 2H stable isotopes. Results indicate that the majority of the groundwater in the study area falls within acceptable limits for domestic use, and although slightly saline, is exploitable for other uses as well. It was also found that dolerite dykes that have intruded into the Karoo Basin sediments have slight effects on the groundwater chemistry, but that these effects are also masked by the water-rock interactions occurring with the aquifer. It was also determined with major ions and stable isotopes that although the coastal aquifers do have saline signatures (EC > 200 mS/m) this is not due to salinisation via seawater intrusion. It is instead postulated that the salinity arises from marine aerosols that have introduced NaCl onto the soil layer, and which then leaches into the groundwater system through precipitation or irrigation. In the event of shale gas extraction through fracking or the expansion of rural and urban centres, this project serves as a preliminary hydrogeochemical baseline before any of these processes proceed within the Karoo Basin.
- Full Text:
- Date Issued: 2020
Identification of differentially expressed proteins involved in wheat (Triticum aestivum) resistance against Russian Wheat Aphid (Diuraphis noxia) SA2 using SWATH-MS analysis
- Authors: Ntlokwana, Sitha Emmanuel
- Date: 2020
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/18872 , vital:42888
- Description: Wheat (Triticum aestivum) is the second most-consumed cereal crop in the world, second only to maize. In South Africa it is mainly produced in three provinces; the Free State, Western Cape, and the Northen Cape. The average total land area used for wheat cultivation in these three Provinces, is 533 000 hectares, with a resultant annual production of between 1.3 to 2 million tons. The total wheat requirement in South Africa is currently 2.7 million tons according to the production of wheat guidelines published by the Department of Agriculture, Forestry and Fisheries, which is higher than the total annual production. One of the primary reasons that contribute to the lower production levels is insect and pest infestation, in particular, the Russian wheat aphid (Diurophis noxis), which can result in crop loss of up to sixty percent. Russian wheat aphids (RWA) are invasive insects that feed on the phloem of the plant through their specialised thin stylet-like mouthparts and release toxic agents contained in their saliva during feeding, which disrupt cellular functions inside the host plant. This damage leads to symptoms like; chlorosis, necrosis, wilting, stunting and curling of leaves, also known as leaf rolling. This study aimed to identify differentially expressed proteins in resistant and susceptible wheat (Triticum aestivum) cultivars during Russian wheat aphid Biotype South African 2 (RWA-SA2) infestation, in order to identify proteins involved in the wheat resistant mechanism against RWA-SA2. Two wheat cultivars SST398 (resistant to RWA-SA2) and SST356 (susceptible to RWA-SA2) were used, and a total number of 126 plants were planted and divided according to four different harvest times (Control day 0; day 5; day 7 and day 12). The wheat plants were infested with approximately 10 aphids per plant at the three-leaf stage, and placed within an insect cage inside a growth chamber (Conviron, Winnipeg, Canada) set at 24ºC, light intensity of 352 µmol.m-2.sec-1, ambient CO2 levels (410 ppm) and humidity of 60% with a 16h/8h day/night cycle. Wheat leaves were harvested at various time frames, and total protein extraction was performed. The protein samples were reduced with 10 mM dithiothreitol (DTT) and alkylated with 30 mM iodoacetamide (IAA). Sample clean-up and on-bead trypsin digest were performed on megReSyn Hilic columns, over four hours. The resultant peptides were vacuum dried and resuspended in 2% acetonitrile (ACN) before submitting them to LC-MS/MS (SWATH) for analysis. A total number of 611 proteins were differentially expressed, of which 19 were identified to be involved in the resistance response of wheat, and an additional 20 involved in biotic stress responses. This study showed that reactive oxidative species (ROS) such as hydrogen peroxide and hydroxyl radicals (OH-) play a significant role in the early stages of wheat resistance against RWA-SA2 infestation. They are involved in cell wall strengthening, activation of defence genes, involvement of phytohormone signals such as salicylic and jasmonic acid, which also mediates the systemic defences such as, systemic acquired resistance (SAR), leading to the expression of pathogen-related proteins such as (thaumatin-like proteins, oxalate oxidase, defensin, chitinase, and thionins). Although up-regulation of photosynthesis proteins such as (chlorophyll a/b binding protein, photosystem I and II, rubisco and divinyl chlorophyllide a, and 8 vinyl-reductase) were seen on both infested cultivars (susceptible and resistance), higher numbers of these classes of proteins were identified in the resistance cultivar, suggesting that they also play a critical role in resistance. In conclusion, the SWATH analysis used in this study was able to identify numerous proteins involved in the wheat resistance mechanism against RWA-SA2, most of which have not yet been reported to be involved in either biotic stress or RWA-SA2 resistance responses. Future studies are required to biochemically confirm the involvement of these enzymes and proteins the specific metabolic pathways where they are found, in the wheat resistance mechanism against Russian wheat aphid Biotype 2
- Full Text:
- Date Issued: 2020
- Authors: Ntlokwana, Sitha Emmanuel
- Date: 2020
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/18872 , vital:42888
- Description: Wheat (Triticum aestivum) is the second most-consumed cereal crop in the world, second only to maize. In South Africa it is mainly produced in three provinces; the Free State, Western Cape, and the Northen Cape. The average total land area used for wheat cultivation in these three Provinces, is 533 000 hectares, with a resultant annual production of between 1.3 to 2 million tons. The total wheat requirement in South Africa is currently 2.7 million tons according to the production of wheat guidelines published by the Department of Agriculture, Forestry and Fisheries, which is higher than the total annual production. One of the primary reasons that contribute to the lower production levels is insect and pest infestation, in particular, the Russian wheat aphid (Diurophis noxis), which can result in crop loss of up to sixty percent. Russian wheat aphids (RWA) are invasive insects that feed on the phloem of the plant through their specialised thin stylet-like mouthparts and release toxic agents contained in their saliva during feeding, which disrupt cellular functions inside the host plant. This damage leads to symptoms like; chlorosis, necrosis, wilting, stunting and curling of leaves, also known as leaf rolling. This study aimed to identify differentially expressed proteins in resistant and susceptible wheat (Triticum aestivum) cultivars during Russian wheat aphid Biotype South African 2 (RWA-SA2) infestation, in order to identify proteins involved in the wheat resistant mechanism against RWA-SA2. Two wheat cultivars SST398 (resistant to RWA-SA2) and SST356 (susceptible to RWA-SA2) were used, and a total number of 126 plants were planted and divided according to four different harvest times (Control day 0; day 5; day 7 and day 12). The wheat plants were infested with approximately 10 aphids per plant at the three-leaf stage, and placed within an insect cage inside a growth chamber (Conviron, Winnipeg, Canada) set at 24ºC, light intensity of 352 µmol.m-2.sec-1, ambient CO2 levels (410 ppm) and humidity of 60% with a 16h/8h day/night cycle. Wheat leaves were harvested at various time frames, and total protein extraction was performed. The protein samples were reduced with 10 mM dithiothreitol (DTT) and alkylated with 30 mM iodoacetamide (IAA). Sample clean-up and on-bead trypsin digest were performed on megReSyn Hilic columns, over four hours. The resultant peptides were vacuum dried and resuspended in 2% acetonitrile (ACN) before submitting them to LC-MS/MS (SWATH) for analysis. A total number of 611 proteins were differentially expressed, of which 19 were identified to be involved in the resistance response of wheat, and an additional 20 involved in biotic stress responses. This study showed that reactive oxidative species (ROS) such as hydrogen peroxide and hydroxyl radicals (OH-) play a significant role in the early stages of wheat resistance against RWA-SA2 infestation. They are involved in cell wall strengthening, activation of defence genes, involvement of phytohormone signals such as salicylic and jasmonic acid, which also mediates the systemic defences such as, systemic acquired resistance (SAR), leading to the expression of pathogen-related proteins such as (thaumatin-like proteins, oxalate oxidase, defensin, chitinase, and thionins). Although up-regulation of photosynthesis proteins such as (chlorophyll a/b binding protein, photosystem I and II, rubisco and divinyl chlorophyllide a, and 8 vinyl-reductase) were seen on both infested cultivars (susceptible and resistance), higher numbers of these classes of proteins were identified in the resistance cultivar, suggesting that they also play a critical role in resistance. In conclusion, the SWATH analysis used in this study was able to identify numerous proteins involved in the wheat resistance mechanism against RWA-SA2, most of which have not yet been reported to be involved in either biotic stress or RWA-SA2 resistance responses. Future studies are required to biochemically confirm the involvement of these enzymes and proteins the specific metabolic pathways where they are found, in the wheat resistance mechanism against Russian wheat aphid Biotype 2
- Full Text:
- Date Issued: 2020
Identification of SANCDB compounds against G2019S and I2020T variants of leucine-rich repeat Kinase 2 (LRRK2) for the development of drugs against Parkinson’s Disease
- Authors: Baye, Bertha Cinthia
- Date: 2020
- Subjects: Antiparkinsonian agents , Parkinson's disease -- Treatment , Protein kinases , Parkinson's disease -- Chemotherapy , Molecules -- Models
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/138764 , vital:37671
- Description: Parkinson’s disease is a type of movement disorder that occurs when nerve cells in the brain stop producing dopamine. It is the second neurodegenerative disease affecting 1-2% of people above the ages of 65 years old. There is a worldwide prevalence of 7 to 10 million affected people of all cultures and race. Studies have shown that mutation that causes Parkinson’s disease result in increased kinase activity. The c.6055 G > A in exon 41 is the most prevalent LRRK2 variation which causes a substitution of glycine to serine in G2019S in the highly activated loop of its MAP kinase domain. The LRRK2 G2019S variant is the most common genetic determinant of Parkinson’s disease identified to date. This work focused on building accurate 3D models of the LRRK2 kinase domain, that were used for large-scale in silico docking against South African natural compounds from the South African Natural Compounds Database (SANCDB; https://sancdb.rubi.ru.ac.za/). Molecular docking was performed to identify compounds that formed interactions with the active site of the protein and had the lowest binding energy scores. Molecular dynamics simulations showed different movements of the protein-ligand complexes and behavioural difference of the wildtype and the variants, all three structures proved to be compact. Network analysis was done to study residue interactions, contact maps, dynamic cross correlations, average BC and average L were used to study the residue interactions and general residue contribution to the functioning of the protein..
- Full Text:
- Date Issued: 2020
- Authors: Baye, Bertha Cinthia
- Date: 2020
- Subjects: Antiparkinsonian agents , Parkinson's disease -- Treatment , Protein kinases , Parkinson's disease -- Chemotherapy , Molecules -- Models
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/138764 , vital:37671
- Description: Parkinson’s disease is a type of movement disorder that occurs when nerve cells in the brain stop producing dopamine. It is the second neurodegenerative disease affecting 1-2% of people above the ages of 65 years old. There is a worldwide prevalence of 7 to 10 million affected people of all cultures and race. Studies have shown that mutation that causes Parkinson’s disease result in increased kinase activity. The c.6055 G > A in exon 41 is the most prevalent LRRK2 variation which causes a substitution of glycine to serine in G2019S in the highly activated loop of its MAP kinase domain. The LRRK2 G2019S variant is the most common genetic determinant of Parkinson’s disease identified to date. This work focused on building accurate 3D models of the LRRK2 kinase domain, that were used for large-scale in silico docking against South African natural compounds from the South African Natural Compounds Database (SANCDB; https://sancdb.rubi.ru.ac.za/). Molecular docking was performed to identify compounds that formed interactions with the active site of the protein and had the lowest binding energy scores. Molecular dynamics simulations showed different movements of the protein-ligand complexes and behavioural difference of the wildtype and the variants, all three structures proved to be compact. Network analysis was done to study residue interactions, contact maps, dynamic cross correlations, average BC and average L were used to study the residue interactions and general residue contribution to the functioning of the protein..
- Full Text:
- Date Issued: 2020
Identifying the causes of widespread illegal dumping in Buffalo City Metropolitan Municipality and innovative waste management mechanism
- Authors: Brown, Drayton
- Date: 2020
- Subjects: Waste minimization -- law and legislation -- South Africa -- Buffalo City Metropolitan Municipality
- Language: English
- Type: Thesis , Masters , Degree
- Identifier: http://hdl.handle.net/10948/49767 , vital:41798
- Description: South Africa faces the daily challenge of illegal dumping and authorities cannot seem to contain the problem. This is particularly the case in Buffalo City Metropolitan Municipality (BCMM) as the same non-effective means of curbing illegal dumping is attempted again and again. This study sought to gain insight into why residents would illegally dump waste near their homes considering the numerous negative health and environmental consequences. While many studies have focused on the quantitative aspects of waste management and illegal dumping, none have been conducted in the Eastern Cape or BCMM or enquired as to how citizens felt about the phenomena. This research utilised in-depth semi-structured interviews to gain insight into the problem of illegal dumping through the lenses of both residents and BCMM staff members. One of the key themes within the findings of the study is the apathetic nature of citizens towards their environment. There are also two predominant ways illegal dumping sites form. The first is through ‘Systemic Dumping’ which arises through the lack of waste infrastructure in low income communities and the second is ‘Ad-hoc Illegal Dumping’which form when BCMM does not provide a timely waste management service.
- Full Text:
- Date Issued: 2020
- Authors: Brown, Drayton
- Date: 2020
- Subjects: Waste minimization -- law and legislation -- South Africa -- Buffalo City Metropolitan Municipality
- Language: English
- Type: Thesis , Masters , Degree
- Identifier: http://hdl.handle.net/10948/49767 , vital:41798
- Description: South Africa faces the daily challenge of illegal dumping and authorities cannot seem to contain the problem. This is particularly the case in Buffalo City Metropolitan Municipality (BCMM) as the same non-effective means of curbing illegal dumping is attempted again and again. This study sought to gain insight into why residents would illegally dump waste near their homes considering the numerous negative health and environmental consequences. While many studies have focused on the quantitative aspects of waste management and illegal dumping, none have been conducted in the Eastern Cape or BCMM or enquired as to how citizens felt about the phenomena. This research utilised in-depth semi-structured interviews to gain insight into the problem of illegal dumping through the lenses of both residents and BCMM staff members. One of the key themes within the findings of the study is the apathetic nature of citizens towards their environment. There are also two predominant ways illegal dumping sites form. The first is through ‘Systemic Dumping’ which arises through the lack of waste infrastructure in low income communities and the second is ‘Ad-hoc Illegal Dumping’which form when BCMM does not provide a timely waste management service.
- Full Text:
- Date Issued: 2020
Identifying the causes of widespread illegal dumping in buffalo city metropolitan municipality and innovative waste management mechanisms
- Authors: Brown, Drayton
- Date: 2020
- Subjects: Refuse and refuse disposal -- South Africa -- Eastern Cape , Municipal Services -- South Africa -- Eastern Cape Waste minimization -- South Africa -- Buffalo City Metropolitan Municipality
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/50444 , vital:42168
- Description: South Africa faces the daily challenge of illegal dumping and authorities cannot seem to contain the problem. This is particularly the case in Buffalo City Metropolitan Municipality (BCMM) as the same non-effective means of curbing illegal dumping is attempted again and again. This study sought to gain insight into why residents would illegally dump waste near their homes considering the numerous negative health and environmental consequences. While many studies have focused on the quantitative aspects of waste management and illegal dumping, none have been conducted in the Eastern Cape or BCMM or enquired as to how citizens felt about the phenomena. This research utilised in-depth semi-structured interviews to gain insight into the problem of illegal dumping through the lenses of both residents and BCMM staff members. One of the key themes within the findings of the study is the apathetic nature of citizens towards their environment. There are also two predominant ways illegal dumping sites form. The first is through ‘Systemic Dumping’ which arises through the lack of waste infrastructure in low income communities and the second is ‘Ad-hoc Illegal Dumping’ which form when BCMM does not provide a timely waste management service.
- Full Text:
- Date Issued: 2020
- Authors: Brown, Drayton
- Date: 2020
- Subjects: Refuse and refuse disposal -- South Africa -- Eastern Cape , Municipal Services -- South Africa -- Eastern Cape Waste minimization -- South Africa -- Buffalo City Metropolitan Municipality
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/50444 , vital:42168
- Description: South Africa faces the daily challenge of illegal dumping and authorities cannot seem to contain the problem. This is particularly the case in Buffalo City Metropolitan Municipality (BCMM) as the same non-effective means of curbing illegal dumping is attempted again and again. This study sought to gain insight into why residents would illegally dump waste near their homes considering the numerous negative health and environmental consequences. While many studies have focused on the quantitative aspects of waste management and illegal dumping, none have been conducted in the Eastern Cape or BCMM or enquired as to how citizens felt about the phenomena. This research utilised in-depth semi-structured interviews to gain insight into the problem of illegal dumping through the lenses of both residents and BCMM staff members. One of the key themes within the findings of the study is the apathetic nature of citizens towards their environment. There are also two predominant ways illegal dumping sites form. The first is through ‘Systemic Dumping’ which arises through the lack of waste infrastructure in low income communities and the second is ‘Ad-hoc Illegal Dumping’ which form when BCMM does not provide a timely waste management service.
- Full Text:
- Date Issued: 2020
Impact of change management on employee engagement
- Authors: Moche, Boitshoko
- Date: 2020
- Subjects: Personnel management Organizational change
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/49703 , vital:41772
- Description: Change is inevitable and change is necessary; in order for organisations to remain competitive they have to keep on evolving, ensuring that the organisational vision and strategy are aligned to the organisation’s vision, importantly, that the employees have a fulfilling work experience in order to do their best and live up to the organisation’s values. In the high-pressured, agile work environment, it is necessary for the organisations to move their processes with the times, providing information on digital platforms while upskilling the employees and saving time. Employee engagement is defined as the force that drives the organisational success and when achieved it eventually leads to high morale, employee retention, employee trust and loyalty to the organisation and organisational performance The aim of the study was to investigate the impact of change management process on the employee engagement in the workplace. The three identified main factors were readiness for change, process of change and leadership involvement. Change initiatives have been reported to fail by 70% if not implemented effectively and can have a negative impact on how the employees receive the change. The mixed method study approach was used, starting with interviews with the four key players in the organisation to establish how they perceive change and gather new information. It was followed by a quantitative e-survey to departments which have had technological change in the past year. The empirical results showed that the there is a relationship between the factors of change and employee engagement. Importance of readiness for change was highlighted, supporting the need for an organisational analysis followed by a detailed change plan aligned to the organisational vision. Process of change had a positive significance for employee engagement while lack of leadership involvement showed the negative relationship to employee engagement. The findings show how change leadership should work in sync with organisational leadership at all times and should incorporate change management into the organisational DNA.
- Full Text:
- Date Issued: 2020
- Authors: Moche, Boitshoko
- Date: 2020
- Subjects: Personnel management Organizational change
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/49703 , vital:41772
- Description: Change is inevitable and change is necessary; in order for organisations to remain competitive they have to keep on evolving, ensuring that the organisational vision and strategy are aligned to the organisation’s vision, importantly, that the employees have a fulfilling work experience in order to do their best and live up to the organisation’s values. In the high-pressured, agile work environment, it is necessary for the organisations to move their processes with the times, providing information on digital platforms while upskilling the employees and saving time. Employee engagement is defined as the force that drives the organisational success and when achieved it eventually leads to high morale, employee retention, employee trust and loyalty to the organisation and organisational performance The aim of the study was to investigate the impact of change management process on the employee engagement in the workplace. The three identified main factors were readiness for change, process of change and leadership involvement. Change initiatives have been reported to fail by 70% if not implemented effectively and can have a negative impact on how the employees receive the change. The mixed method study approach was used, starting with interviews with the four key players in the organisation to establish how they perceive change and gather new information. It was followed by a quantitative e-survey to departments which have had technological change in the past year. The empirical results showed that the there is a relationship between the factors of change and employee engagement. Importance of readiness for change was highlighted, supporting the need for an organisational analysis followed by a detailed change plan aligned to the organisational vision. Process of change had a positive significance for employee engagement while lack of leadership involvement showed the negative relationship to employee engagement. The findings show how change leadership should work in sync with organisational leadership at all times and should incorporate change management into the organisational DNA.
- Full Text:
- Date Issued: 2020
Impact of digital age on street traders in Buffalo City and preparation for future economic activity
- Authors: Mkonwana, Siyasanga Phiwe
- Date: 2020
- Subjects: LCSH LCSH
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/49681 , vital:41770
- Description: The study was focusing on the street trading as a form of informal trade in Buffalo City, and how the digital age has impacted on the street traders. Street trading is a form of informal trade that takes place in many developing countries. It is mostly located in urban areas, towns and cities where there is foot traffic. Traditionally, street trading has not been recognised as contributing to the economy of a country (Robinson, 2002). The lack of economic acknowledgement has led to street trading issues being largely ignored or referred to urban managers (Lyons and Snoxell, 2005). Digitalisation has shifted the world’s paradigm and has impacted the business and its operations. The world is currently in the ‘digital age’, where everything is done (or will soon be done) through the use of technology such as cell phones, the internet of things (IoT), driverless cars, and three-dimensional (3D) technology (WEF, 2018). Technology also promote continuous new invention and innovation (World Trade Report [WTR], 2017). In the workplace, digitisation is estimated to have an increasingly negative impact on the labour market in the developing countries, leading to higher unemployment rates and low productivity (UNCTA, 2016). Semi-structured focused interviews were used to collect data for the research from 10 street traders in the BCMM area of the Eastern Cape, South Africa. The interviews were undertaken between November 2018 and January 2019. There are two predominant paradigms used for the research, namely the constructivist/ interpretative and the positivist/post-positivist paradigms (Cillisa, 2011). Data analysis was done through linking the empirical data to the propositions and interpretations were done in the last chapter.
- Full Text:
- Date Issued: 2020
Impact of digital age on street traders in Buffalo City and preparation for future economic activity
- Authors: Mkonwana, Siyasanga Phiwe
- Date: 2020
- Subjects: LCSH LCSH
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/49681 , vital:41770
- Description: The study was focusing on the street trading as a form of informal trade in Buffalo City, and how the digital age has impacted on the street traders. Street trading is a form of informal trade that takes place in many developing countries. It is mostly located in urban areas, towns and cities where there is foot traffic. Traditionally, street trading has not been recognised as contributing to the economy of a country (Robinson, 2002). The lack of economic acknowledgement has led to street trading issues being largely ignored or referred to urban managers (Lyons and Snoxell, 2005). Digitalisation has shifted the world’s paradigm and has impacted the business and its operations. The world is currently in the ‘digital age’, where everything is done (or will soon be done) through the use of technology such as cell phones, the internet of things (IoT), driverless cars, and three-dimensional (3D) technology (WEF, 2018). Technology also promote continuous new invention and innovation (World Trade Report [WTR], 2017). In the workplace, digitisation is estimated to have an increasingly negative impact on the labour market in the developing countries, leading to higher unemployment rates and low productivity (UNCTA, 2016). Semi-structured focused interviews were used to collect data for the research from 10 street traders in the BCMM area of the Eastern Cape, South Africa. The interviews were undertaken between November 2018 and January 2019. There are two predominant paradigms used for the research, namely the constructivist/ interpretative and the positivist/post-positivist paradigms (Cillisa, 2011). Data analysis was done through linking the empirical data to the propositions and interpretations were done in the last chapter.
- Full Text:
- Date Issued: 2020
Impact of fracking fluid on Karoo plants based on field and greenhouse experiments
- Authors: Liddell, Duncan Carlyle
- Date: 2020
- Subjects: Plants -- South Africa -- Little Karoo , Desert ecology -- South Africa Great Karoo (South Africa)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/49125 , vital:41603
- Description: Fracking fluid has been indicated to be detrimental to vegetation. In forest vegetation the fracking fluid caused ground vegetation to be extensively damaged with high mortality rates and trees showing premature leaf loss following application. A study by Martin (2017) investigated these effects on Karoo vegetation in a greenhouse and found it to increase stress and reduced the growth with some life forms being identified as sensitive. The current study followed on the work of Martin testing additional species in the same greenhouse and applying different treatments of fracking fluid to Karoo vegetation in their habitat. The plants were monitored by measuring their height, photosynthetic efficiency (stress), biomass allocation and the temperature of the sites. The greenhouse plants had increased growth associated with repeated fracking fluid treatments while having variable stress levels with different treatments of the fracking fluid. The farm had mixed results being generally more stressed due to the treatments, the repeated fracking fluid treatments showed greater growth. The farm vegetation was more sensitive due to prolonged drought which is suspected to play a large role in the different response to fracking fluid between the two sites. The several hypotheses based on the finding of Martin (2017) were not supported by the data in this study. However, the application of fracking fluid did affect the tree species as they were found to be sensitive, while the other plant species was generally stressed after the applications. The greenhouse study cannot accurately represent the effects of fracking fluid on the farm vegetation, due to the large difference in the environment thus, more field studies would need to be conducted to determine the effects of fracking fluid.
- Full Text:
- Date Issued: 2020
- Authors: Liddell, Duncan Carlyle
- Date: 2020
- Subjects: Plants -- South Africa -- Little Karoo , Desert ecology -- South Africa Great Karoo (South Africa)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/49125 , vital:41603
- Description: Fracking fluid has been indicated to be detrimental to vegetation. In forest vegetation the fracking fluid caused ground vegetation to be extensively damaged with high mortality rates and trees showing premature leaf loss following application. A study by Martin (2017) investigated these effects on Karoo vegetation in a greenhouse and found it to increase stress and reduced the growth with some life forms being identified as sensitive. The current study followed on the work of Martin testing additional species in the same greenhouse and applying different treatments of fracking fluid to Karoo vegetation in their habitat. The plants were monitored by measuring their height, photosynthetic efficiency (stress), biomass allocation and the temperature of the sites. The greenhouse plants had increased growth associated with repeated fracking fluid treatments while having variable stress levels with different treatments of the fracking fluid. The farm had mixed results being generally more stressed due to the treatments, the repeated fracking fluid treatments showed greater growth. The farm vegetation was more sensitive due to prolonged drought which is suspected to play a large role in the different response to fracking fluid between the two sites. The several hypotheses based on the finding of Martin (2017) were not supported by the data in this study. However, the application of fracking fluid did affect the tree species as they were found to be sensitive, while the other plant species was generally stressed after the applications. The greenhouse study cannot accurately represent the effects of fracking fluid on the farm vegetation, due to the large difference in the environment thus, more field studies would need to be conducted to determine the effects of fracking fluid.
- Full Text:
- Date Issued: 2020
Impacts of cattle grazing pressure on vegetation and soil characteristics in an arid grassland of South Africa
- Authors: Botha, Gert Stephanus
- Date: 2020
- Subjects: Grazing -- Environmental aspects -- South Africa , Cattle -- Feeding and feeds -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/${Handle} , vital:39749
- Description: Natural rangelands are often degraded due to the implementation of incorrect grazing systems. One potential solution is the use of short duration, high intensity grazing. The impacts of this grazing system on, inter alia, vegetation and soil properties have not yet been comprehensively tested within the arid rangelands of South Africa. This study aimed to determine the impacts of grazing intensity on vegetation composition, forage quantity and quality, and soil compaction, soil water infiltration rates and soil chemical properties in an arid grassland in South Africa. The following three grazing treatments were compared: no grazing (NG), low intensity grazing (LIG) and high intensity grazing (HIG). A total of 18 plots (six replicates per treatment) were grazed with Bonsmara cattle. Each plot, 4 ha in size, was surveyed pre-grazing, directly after grazing, and again three, six and 12 months post-grazing. The results indicated that different grazing intensities did not affect grass diversity and the veld condition a year after grazing. Phytomass was influenced by grazing intensity, with no grazing having the highest phytomass throughout the study period. Soil compaction differed among seasons but not among treatments, with summer surveys recording the lowest soil compaction rates. The soil water infiltration rates did not differ between the three different treatments, indicating that grazing intensity did not affect infiltration rates. However, grazing did seem to improve soil nutrient levels when compared to NG. The grazed treatments had higher NH4+, K+, and organic carbon than the NG treatment. Nevertheless, there was no significant difference in nutrients levels when comparing the LIG system to the HIG system. When comparing the soil nutrients levels within a treatment over time, only the HIG treatment showed an increase in soil nutrient levels (Mg2+) over time, whereas the LIG and NG treatments showed no changed throughout the study period. Generally, the study results indicated that in the short term there was no advantage to using higher grazing intensity, although the presence of grazing (as opposed to no grazing) is advantageous to arid grassland functioning.
- Full Text:
- Date Issued: 2020
- Authors: Botha, Gert Stephanus
- Date: 2020
- Subjects: Grazing -- Environmental aspects -- South Africa , Cattle -- Feeding and feeds -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/${Handle} , vital:39749
- Description: Natural rangelands are often degraded due to the implementation of incorrect grazing systems. One potential solution is the use of short duration, high intensity grazing. The impacts of this grazing system on, inter alia, vegetation and soil properties have not yet been comprehensively tested within the arid rangelands of South Africa. This study aimed to determine the impacts of grazing intensity on vegetation composition, forage quantity and quality, and soil compaction, soil water infiltration rates and soil chemical properties in an arid grassland in South Africa. The following three grazing treatments were compared: no grazing (NG), low intensity grazing (LIG) and high intensity grazing (HIG). A total of 18 plots (six replicates per treatment) were grazed with Bonsmara cattle. Each plot, 4 ha in size, was surveyed pre-grazing, directly after grazing, and again three, six and 12 months post-grazing. The results indicated that different grazing intensities did not affect grass diversity and the veld condition a year after grazing. Phytomass was influenced by grazing intensity, with no grazing having the highest phytomass throughout the study period. Soil compaction differed among seasons but not among treatments, with summer surveys recording the lowest soil compaction rates. The soil water infiltration rates did not differ between the three different treatments, indicating that grazing intensity did not affect infiltration rates. However, grazing did seem to improve soil nutrient levels when compared to NG. The grazed treatments had higher NH4+, K+, and organic carbon than the NG treatment. Nevertheless, there was no significant difference in nutrients levels when comparing the LIG system to the HIG system. When comparing the soil nutrients levels within a treatment over time, only the HIG treatment showed an increase in soil nutrient levels (Mg2+) over time, whereas the LIG and NG treatments showed no changed throughout the study period. Generally, the study results indicated that in the short term there was no advantage to using higher grazing intensity, although the presence of grazing (as opposed to no grazing) is advantageous to arid grassland functioning.
- Full Text:
- Date Issued: 2020
Implementation of Professional Development Programmes For Grade R Teachers: A case study of four primary schools in Amathole West Education District, Eastern Cape
- Authors: Jumo, Theresa
- Date: 2020
- Subjects: Teachers -- Development -- Eastern Cape -- South Africa Teachers -- Vocational guidance -- Eastern Cape -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10353/11341 , vital:39061
- Description: This study investigated the implementation of Professional Development Programmes for Grade R teachers in four primary schools in Amathole West Education District. The interpretive paradigm was employed in this study because it focused on the teachers’ professional development and their participation in a social learning interaction as community of practice. Furthermore, a qualitative approach was used for the collection of data so as to gain in-depth information on the implementation of professional development programmes. Semi-structured interviews and document analysis were used as a form of collecting data. The participants were purposively selected for the sample of this study and comprised of 4 Principals, 1 Subject Advisor and 4 Teachers. Data analysis was done in line with the research questions, aims and objectives of the study. Through the participants’ answers from schools under study, a transcript was formulated, coded and categorized in view of the implementation of Professional Development Programmes for Grade R teachers. The data revealed that Grade R teachers under study were under qualified such that none of the teachers had the recommended Diploma in Grade R qualification as stated by the Department of Basic Education. It was also found that there was diversity in the teachers’ qualifications, colleges and the length in training. The study also indicated that although professional development programmes were held, these were however not properly monitored. Findings also revealed that the intervention strategies through professional development programmes and the support given by the district and the schools were strategies through professional development programmes and the support given by the district and the schools were not adequate and consistent. As a result the participants encountered a number of challenges regarding the implementation of professional development programmes for Grade R teachers. Namely: (1) lack of appropriately qualified personnel to support the teachers both at school and the district (2) lack of adequate follow up support visits and feedbacks from both the school and the district (3) lack of proper management by the schools and (4) lack of collaboration ii and team work in the schools. Thus, there were variances in schools under study especially with regards to late release of funding for teaching and learning materials, support offered to the principals by the Department of Education. As a result, recommendations from the study suggested that the Department of Education and the District have to come up with more strategies of continuously training the teachers and the principals and offering strong and adequate support. The study also recommended the engagement of NGOs for job embedded professional development with longer in-service training periods as compared to the shot in-service professional development programs of once- off workshops. Also another suggestion that the district must monitor school based professional development programs regularly was raised in the study
- Full Text:
- Date Issued: 2020
- Authors: Jumo, Theresa
- Date: 2020
- Subjects: Teachers -- Development -- Eastern Cape -- South Africa Teachers -- Vocational guidance -- Eastern Cape -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10353/11341 , vital:39061
- Description: This study investigated the implementation of Professional Development Programmes for Grade R teachers in four primary schools in Amathole West Education District. The interpretive paradigm was employed in this study because it focused on the teachers’ professional development and their participation in a social learning interaction as community of practice. Furthermore, a qualitative approach was used for the collection of data so as to gain in-depth information on the implementation of professional development programmes. Semi-structured interviews and document analysis were used as a form of collecting data. The participants were purposively selected for the sample of this study and comprised of 4 Principals, 1 Subject Advisor and 4 Teachers. Data analysis was done in line with the research questions, aims and objectives of the study. Through the participants’ answers from schools under study, a transcript was formulated, coded and categorized in view of the implementation of Professional Development Programmes for Grade R teachers. The data revealed that Grade R teachers under study were under qualified such that none of the teachers had the recommended Diploma in Grade R qualification as stated by the Department of Basic Education. It was also found that there was diversity in the teachers’ qualifications, colleges and the length in training. The study also indicated that although professional development programmes were held, these were however not properly monitored. Findings also revealed that the intervention strategies through professional development programmes and the support given by the district and the schools were strategies through professional development programmes and the support given by the district and the schools were not adequate and consistent. As a result the participants encountered a number of challenges regarding the implementation of professional development programmes for Grade R teachers. Namely: (1) lack of appropriately qualified personnel to support the teachers both at school and the district (2) lack of adequate follow up support visits and feedbacks from both the school and the district (3) lack of proper management by the schools and (4) lack of collaboration ii and team work in the schools. Thus, there were variances in schools under study especially with regards to late release of funding for teaching and learning materials, support offered to the principals by the Department of Education. As a result, recommendations from the study suggested that the Department of Education and the District have to come up with more strategies of continuously training the teachers and the principals and offering strong and adequate support. The study also recommended the engagement of NGOs for job embedded professional development with longer in-service training periods as compared to the shot in-service professional development programs of once- off workshops. Also another suggestion that the district must monitor school based professional development programs regularly was raised in the study
- Full Text:
- Date Issued: 2020
Implementation of safety measures in selected public high schools in the Alfred Nzo East education district
- Authors: Mditshwa, Simbongile
- Date: 2020
- Subjects: Schools -- Security measures School safety and security
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10353/17895 , vital:41975
- Description: The main aim of the study was to find out how safety measures are implemented in selected public high schools in the Alfred Nzo East Education District. The study was motivated by multiple media reports about incidents that have to do with the safety of learners especially in rural public schools. This case study was grounded in the interpretive paradigm and the qualitative approach was adopted. The study was theoretically guided by the principles from both the Street-Level Bureaucracy (SLB) and the Rational Decision Making Model (RDMM). The data was collected from three schools in the Alfred Nzo East Education District, Eastern Cape, RSA. A purposive sampling technique was utilized to choose the research participants. A total of 21 human participants were involved in interviews where two teachers per school, two learners per school, two SGB parents and a principal were interviewed. Interviews were supplemented with short observations and document analysis. The findings of the research include the following: educators get a minimal empowerment to manage school safety in terms of access to school, scholar transport and on. The researched schools had no school-based safety policies. Some of the challenges included the level of roadworthiness of the vehicles that are used to transport school children which exposes learners to a high risk and that puts more pressure on school safety. Drugs and dangerous weapons are other factors which contribute to the instability of school safety. The researcher recommended that educators should be empowered through support from the principals and from the district coordinator through frequent policy implementation conference using online platform to minimize the costs of physical conferences. I recommended that the community must be active whistle-blowers for drug smuggling because drugs in schools emanate from the communities. Indemnity forms, release forms and school-based policies must be made available for implementation and referencing purposes. Schools should establish healthy relationship with external stakeholders like traditional leaders, SAPS and the Department of Social Development to curb lack of safety in schools.
- Full Text:
- Date Issued: 2020
- Authors: Mditshwa, Simbongile
- Date: 2020
- Subjects: Schools -- Security measures School safety and security
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10353/17895 , vital:41975
- Description: The main aim of the study was to find out how safety measures are implemented in selected public high schools in the Alfred Nzo East Education District. The study was motivated by multiple media reports about incidents that have to do with the safety of learners especially in rural public schools. This case study was grounded in the interpretive paradigm and the qualitative approach was adopted. The study was theoretically guided by the principles from both the Street-Level Bureaucracy (SLB) and the Rational Decision Making Model (RDMM). The data was collected from three schools in the Alfred Nzo East Education District, Eastern Cape, RSA. A purposive sampling technique was utilized to choose the research participants. A total of 21 human participants were involved in interviews where two teachers per school, two learners per school, two SGB parents and a principal were interviewed. Interviews were supplemented with short observations and document analysis. The findings of the research include the following: educators get a minimal empowerment to manage school safety in terms of access to school, scholar transport and on. The researched schools had no school-based safety policies. Some of the challenges included the level of roadworthiness of the vehicles that are used to transport school children which exposes learners to a high risk and that puts more pressure on school safety. Drugs and dangerous weapons are other factors which contribute to the instability of school safety. The researcher recommended that educators should be empowered through support from the principals and from the district coordinator through frequent policy implementation conference using online platform to minimize the costs of physical conferences. I recommended that the community must be active whistle-blowers for drug smuggling because drugs in schools emanate from the communities. Indemnity forms, release forms and school-based policies must be made available for implementation and referencing purposes. Schools should establish healthy relationship with external stakeholders like traditional leaders, SAPS and the Department of Social Development to curb lack of safety in schools.
- Full Text:
- Date Issued: 2020
In vitro susceptibility of Staphylococcus aureus to porphyrin-silver mediated photodynamic antimicrobial chemotherapy
- Authors: Shabangu, Samuel Malewa
- Date: 2020
- Subjects: Porphyrins , Nanoparticles , Photochemotherapy , Drug resistance in microorganisms , Staphylococcus aureus
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/167476 , vital:41484
- Description: This work reports on the syntheses and characterization of symmetrical and unsymmetrical porphyrin complexes namely, 5,10,15,20-tetra(4-pyridyl)-porphyrinato zinc(II) (1), 5,10,15,20-tetrathienyl porphyrinato zinc(II) (2), 5-(4-hydroxyphenyl)-10, 15, 20-tris(2-thienyl) porphyrinato zinc(II) (3), 5-(4-carboxyphenyl)-10,15,20-tris(pentafluorophenyl)- porphyrinato zinc(II) (4), 5-(4-carboxyphenyl)-10,15,20-triphenyl-porphyrinato zinc(II) (5) and 5-(4-carboxyphenyl)-10, 15, 20-tris(2-thienyl)-porphyrinato zinc(II) (6). The synthesis of silver nanoparticles (AgNPs) was also undertaken in this research work. Complexes 1, 2, 3 and 6 were linked to oleic acid/oleylamine functionalized nanoparticles via self-assembly and 4-6 were linked via covalent interaction through an amide bond to glutathione capped AgNPs. The effect of nature of bond along with symmetry were investigated, of interest were the five membered thienyl substituents. The photophysical and photochemical behaviour of the complexes and their conjugates with AgNPs were investigated in dimethylformamide. The porphyrin and AgNPs conjugates afforded an increase in singlet oxygen quantum yield. Complexes 1-6 and their conjugates were used for photodynamic antimicrobial chemotherapy of Staphylococcus aureus. The antimicrobial studies were done in two different concentrations of 0.36 and 2.0 μg/mL. The thienyl substituted porphyrin complexes and their conjugates gave better photodynamic activity as compared to phenyl analogues
- Full Text:
- Date Issued: 2020
- Authors: Shabangu, Samuel Malewa
- Date: 2020
- Subjects: Porphyrins , Nanoparticles , Photochemotherapy , Drug resistance in microorganisms , Staphylococcus aureus
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/167476 , vital:41484
- Description: This work reports on the syntheses and characterization of symmetrical and unsymmetrical porphyrin complexes namely, 5,10,15,20-tetra(4-pyridyl)-porphyrinato zinc(II) (1), 5,10,15,20-tetrathienyl porphyrinato zinc(II) (2), 5-(4-hydroxyphenyl)-10, 15, 20-tris(2-thienyl) porphyrinato zinc(II) (3), 5-(4-carboxyphenyl)-10,15,20-tris(pentafluorophenyl)- porphyrinato zinc(II) (4), 5-(4-carboxyphenyl)-10,15,20-triphenyl-porphyrinato zinc(II) (5) and 5-(4-carboxyphenyl)-10, 15, 20-tris(2-thienyl)-porphyrinato zinc(II) (6). The synthesis of silver nanoparticles (AgNPs) was also undertaken in this research work. Complexes 1, 2, 3 and 6 were linked to oleic acid/oleylamine functionalized nanoparticles via self-assembly and 4-6 were linked via covalent interaction through an amide bond to glutathione capped AgNPs. The effect of nature of bond along with symmetry were investigated, of interest were the five membered thienyl substituents. The photophysical and photochemical behaviour of the complexes and their conjugates with AgNPs were investigated in dimethylformamide. The porphyrin and AgNPs conjugates afforded an increase in singlet oxygen quantum yield. Complexes 1-6 and their conjugates were used for photodynamic antimicrobial chemotherapy of Staphylococcus aureus. The antimicrobial studies were done in two different concentrations of 0.36 and 2.0 μg/mL. The thienyl substituted porphyrin complexes and their conjugates gave better photodynamic activity as compared to phenyl analogues
- Full Text:
- Date Issued: 2020
Inclusion in organisations following disability
- Authors: Durrheim, Zenita Beth
- Date: 2020
- Subjects: People with disabilities -- Employment -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/47818 , vital:40380
- Description: Given the prevalence of disability in South Africa and specifically amongst the working population, this study explores the experiences of individuals who have been rendered disabled following injury and have returned to work. This study used a qualitative research design, specifically from an interpretative perspective to gain an understanding of individuals’ experiences of inclusion in organisations following disability due to injury. The phenomenological approach was best suited to this study in terms of its provision of valuable data collection directly from the participants, based on their own unique experiences. The research methodology was based on a multiple case study approach. Semi-structured interviews were conducted with 11 identified participants through purposive sampling. Through thematic analysis, five themes of inclusion were identified including ‘supportive relationships’, ‘organisational support, accommodation and policies’, ‘nature of the working environment’, ‘work ability and financial implications’ and finally ‘personal well-being’. Furthermore, for each of the primary themes, 12 sub-themes were identified. These themes and sub-themes were explored in relation to participant experiences of inclusion as well as linking specific literature of inclusion, return-to-work and disability models to the themes presented. Linking the findings to existing theoretical models of inclusion provided context with many of the themes identified also evident within the theoretical models. The factors identified within the themes of inclusion were conceptualised at different systemic levels with eight factors identified at the macro-organisational level, nine factors at the meso-group level and eight factors at the micro-group level. These identified factors could aid organisations and policymakers to ensure the effective inclusion of individuals with disabilities in organisations.
- Full Text:
- Date Issued: 2020
- Authors: Durrheim, Zenita Beth
- Date: 2020
- Subjects: People with disabilities -- Employment -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/47818 , vital:40380
- Description: Given the prevalence of disability in South Africa and specifically amongst the working population, this study explores the experiences of individuals who have been rendered disabled following injury and have returned to work. This study used a qualitative research design, specifically from an interpretative perspective to gain an understanding of individuals’ experiences of inclusion in organisations following disability due to injury. The phenomenological approach was best suited to this study in terms of its provision of valuable data collection directly from the participants, based on their own unique experiences. The research methodology was based on a multiple case study approach. Semi-structured interviews were conducted with 11 identified participants through purposive sampling. Through thematic analysis, five themes of inclusion were identified including ‘supportive relationships’, ‘organisational support, accommodation and policies’, ‘nature of the working environment’, ‘work ability and financial implications’ and finally ‘personal well-being’. Furthermore, for each of the primary themes, 12 sub-themes were identified. These themes and sub-themes were explored in relation to participant experiences of inclusion as well as linking specific literature of inclusion, return-to-work and disability models to the themes presented. Linking the findings to existing theoretical models of inclusion provided context with many of the themes identified also evident within the theoretical models. The factors identified within the themes of inclusion were conceptualised at different systemic levels with eight factors identified at the macro-organisational level, nine factors at the meso-group level and eight factors at the micro-group level. These identified factors could aid organisations and policymakers to ensure the effective inclusion of individuals with disabilities in organisations.
- Full Text:
- Date Issued: 2020
Index of coordination for swimming and running in triathletes: a comparative study
- Authors: Van Den Bergh, Katelyne Mei
- Date: 2020
- Subjects: Triathletes
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/46406 , vital:39598
- Description: The primary aim of this study was to compare the Index of Coordination (IdC) for both sprint and endurance swimming and running of less-skilled level triathletes. The researchutilised a quantitative approach, specifically exploratory, with a one group post-test-only research design. Twenty participants from the triathlon community, ages 18 years and older, were selected via purposive and convenient sampling. The participants were expected to complete a total of four physical tests, namely 50 m sprint swim, 1500 m endurance swim, 50 m sprint run,and 5000 m endurance run, on four separate days, over a period of two weeks. The data was collected by video recording each participant performing each of the four different tests andcoded frame-by-frame onDartfish Video Solution (10.0).The IdCwas derived by identifying the time-in markers and time-out markers for both left and right arms when swimming; and by identifying the time-on markers and time-off markers for both left and right legs when running. The results revealed significant differencesbetweenthe IdCvalues ofsprint swimming and endurance swimming(p<0.001); sprint running andendurance running(p<0.001); sprint swimming andsprint running(p<0.001); andendurance swimmingandendurance running(p<0.001).The top performersin each testwere significantly faster than bottom performers(sprint swimming: p<0.001; sprint running:p<0.001; endurance swimming: p<0.001; endurance running: p<0.001) but no significant group differences on associated IdC were found(sprint swimming: p=0.535; sprint running: p=0.857; endurance swimming: p=0.132; endurance running: p=0.775).Bothendurance tests were divided into three equal portions and it was found that 23% ofthe fastest trial endurance swim time can be explained by the IdC obtained in portion three(p=0.032); and that 62% of the fastest trial endurance run time can be explained by the IdC obtained in portion one(p<0.001). The overall findings of the study suggest that an IdC mode is considered efficient relative to the environmental contextand thatIdCis relative to skill level or alternatively independent of performance times. The IdC, therefore, remains inconclusive as an alternative method but warrants further investigation particularly in longer distance endurance events.
- Full Text:
- Date Issued: 2020
- Authors: Van Den Bergh, Katelyne Mei
- Date: 2020
- Subjects: Triathletes
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/46406 , vital:39598
- Description: The primary aim of this study was to compare the Index of Coordination (IdC) for both sprint and endurance swimming and running of less-skilled level triathletes. The researchutilised a quantitative approach, specifically exploratory, with a one group post-test-only research design. Twenty participants from the triathlon community, ages 18 years and older, were selected via purposive and convenient sampling. The participants were expected to complete a total of four physical tests, namely 50 m sprint swim, 1500 m endurance swim, 50 m sprint run,and 5000 m endurance run, on four separate days, over a period of two weeks. The data was collected by video recording each participant performing each of the four different tests andcoded frame-by-frame onDartfish Video Solution (10.0).The IdCwas derived by identifying the time-in markers and time-out markers for both left and right arms when swimming; and by identifying the time-on markers and time-off markers for both left and right legs when running. The results revealed significant differencesbetweenthe IdCvalues ofsprint swimming and endurance swimming(p<0.001); sprint running andendurance running(p<0.001); sprint swimming andsprint running(p<0.001); andendurance swimmingandendurance running(p<0.001).The top performersin each testwere significantly faster than bottom performers(sprint swimming: p<0.001; sprint running:p<0.001; endurance swimming: p<0.001; endurance running: p<0.001) but no significant group differences on associated IdC were found(sprint swimming: p=0.535; sprint running: p=0.857; endurance swimming: p=0.132; endurance running: p=0.775).Bothendurance tests were divided into three equal portions and it was found that 23% ofthe fastest trial endurance swim time can be explained by the IdC obtained in portion three(p=0.032); and that 62% of the fastest trial endurance run time can be explained by the IdC obtained in portion one(p<0.001). The overall findings of the study suggest that an IdC mode is considered efficient relative to the environmental contextand thatIdCis relative to skill level or alternatively independent of performance times. The IdC, therefore, remains inconclusive as an alternative method but warrants further investigation particularly in longer distance endurance events.
- Full Text:
- Date Issued: 2020
Influence of Tamarix species on soil physicochemical properties and mapping its distribution and density using GIS in Western Cape, South Africa
- Authors: Mlahlwa, Asiphe
- Date: 2020
- Subjects: Tamarisks
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/18588 , vital:42611
- Description: Tamarix ramosissima invasion is unarguably one of the worst ecological disasters in South Africa and is classified under category 1b by the National Environmental Management: Biodiversity Act 2014 (NEM: BA). The exotic Tamarix species was introduced in South Africa during the early 1900s as an ornamental or phytoremediating plant. This study was conducted to assess Tamarix distribution and evaluate its impact on soil physicochemical properties in two sites at Leeu River and Olifant River in Western Cape, South Africa. Samples were collected from Leeu River (which consists both the exotic and native Tamarix species) and Olifant River (only exotic Tamarix species). Three transects were laid from the water point outwards, with exotic Tamarix invading the river bank (first transect), the control on the open land (second transect) and the native Tamarix at the far end of the study site (third transect) in Leeu River. In Olifant, transects were laid according to the degree of invasion, low Tamarix density transect was referred to as T1, the medium as T2 and the high density as T3. Soil samples from each transect were taken from three points, at three soil depths (0-10, 10-20 and 20-30 cm) during winter and summer. Soil physiochemical properties such as soil pH, electro-conductivity (EC), total nitrogen (TN), total carbon (TC), soil organic carbon (SOC), sodium (Na+ ), potassium (K+ ), Calcium (Ca2+), Magnesium (Mg2+), bulk density, soil texture and sodium adsorption ratio (SAR) were determined. Soil chemicals properties including EC, Na+ , SAR, K+ and Mg2+ were found significantly higher under the native and the exotic Tamarix species when compared to Tamarix free soils. In general, salinity of surface soils (0–10 cm) was greater than those in the deeper soils with 5.05 mS/cm and 4.73 mS/cm observed under exotic and native Tamarix species, respectively. High levels of EC, K+ , Ca2+, Na+ , SAR, TN, TC and SOC were observed under T3, followed by T2 with the lowest being recorded in T1 at 0-10 cm. Unlike the soil EC, the effect of Tamarix density on soil pH at 0-10 cm soil profile was not significant. Alterations of soil physicochemical properties were more pronounced under the high Tamarix density as compared to the low invasion. Increased in distance from the river was related to a higher density of the invasive species and also topography had a major role in the change of species density. An increase in Tamarix density, results in high leaf litter which in turn results in salinity and soil nutrient at 0-10 cm. Soil salinity was dramatically increased under Tamarix species. Tamarix species are capable of altering the soil properties making it conducive for their growth.
- Full Text:
- Date Issued: 2020
- Authors: Mlahlwa, Asiphe
- Date: 2020
- Subjects: Tamarisks
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/18588 , vital:42611
- Description: Tamarix ramosissima invasion is unarguably one of the worst ecological disasters in South Africa and is classified under category 1b by the National Environmental Management: Biodiversity Act 2014 (NEM: BA). The exotic Tamarix species was introduced in South Africa during the early 1900s as an ornamental or phytoremediating plant. This study was conducted to assess Tamarix distribution and evaluate its impact on soil physicochemical properties in two sites at Leeu River and Olifant River in Western Cape, South Africa. Samples were collected from Leeu River (which consists both the exotic and native Tamarix species) and Olifant River (only exotic Tamarix species). Three transects were laid from the water point outwards, with exotic Tamarix invading the river bank (first transect), the control on the open land (second transect) and the native Tamarix at the far end of the study site (third transect) in Leeu River. In Olifant, transects were laid according to the degree of invasion, low Tamarix density transect was referred to as T1, the medium as T2 and the high density as T3. Soil samples from each transect were taken from three points, at three soil depths (0-10, 10-20 and 20-30 cm) during winter and summer. Soil physiochemical properties such as soil pH, electro-conductivity (EC), total nitrogen (TN), total carbon (TC), soil organic carbon (SOC), sodium (Na+ ), potassium (K+ ), Calcium (Ca2+), Magnesium (Mg2+), bulk density, soil texture and sodium adsorption ratio (SAR) were determined. Soil chemicals properties including EC, Na+ , SAR, K+ and Mg2+ were found significantly higher under the native and the exotic Tamarix species when compared to Tamarix free soils. In general, salinity of surface soils (0–10 cm) was greater than those in the deeper soils with 5.05 mS/cm and 4.73 mS/cm observed under exotic and native Tamarix species, respectively. High levels of EC, K+ , Ca2+, Na+ , SAR, TN, TC and SOC were observed under T3, followed by T2 with the lowest being recorded in T1 at 0-10 cm. Unlike the soil EC, the effect of Tamarix density on soil pH at 0-10 cm soil profile was not significant. Alterations of soil physicochemical properties were more pronounced under the high Tamarix density as compared to the low invasion. Increased in distance from the river was related to a higher density of the invasive species and also topography had a major role in the change of species density. An increase in Tamarix density, results in high leaf litter which in turn results in salinity and soil nutrient at 0-10 cm. Soil salinity was dramatically increased under Tamarix species. Tamarix species are capable of altering the soil properties making it conducive for their growth.
- Full Text:
- Date Issued: 2020