Green synthesis of antimicrobial silver nanoparticles using aqueous leaf extracts from three Congolese plant species (Brillantaisia patula, Crossopteryx febrifuga and Senna siamea)
- Kambale, Espoir K, Nkanga, Christian I, Mutonkole, Blaise-Pascal I, Bapolisi, Alain M, Tassa, Daniel O, Liesse, Jean-Marie I, Krause, Rui W M, Memvanga, Patrick B
- Authors: Kambale, Espoir K , Nkanga, Christian I , Mutonkole, Blaise-Pascal I , Bapolisi, Alain M , Tassa, Daniel O , Liesse, Jean-Marie I , Krause, Rui W M , Memvanga, Patrick B
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193419 , vital:45330 , xlink:href="https://doi.org/10.1016/j.heliyon.2020.e04493"
- Description: In the present study, silver nanoparticles (AgNPs) were synthesized using aqueous leaf extracts of three Congolese plant species, namely Brillantaisia patula (BR-PA), Crossopteryx febrifuga (CR-FE) and Senna siamea (SE-SI). The obtained AgNPs were studied for their optical, structural, surface morphological and antibacterial properties. The prepared AgNPs were characterized by using UV-Visible spectra, Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray spectroscopy (EDX) and X-ray diffractometer (XRD). The synthesized nanoparticles were spherical shaped and well-dispersed with average sizes ranging from 45 to 110 nm. The AgNPs derived from BR-PA, CR-FE and SE-SI exhibited higher antibacterial activity against three bacterial pathogens of the human skin compared to their respective crude extracts and AgNO3. This indicated that the biomolecules covering the nanoparticles may enhance the biological activity of metal nanoparticles. Hence, our results support that biogenic synthesis of AgNPs from Congolese plants constitutes a potential area of interest for the therapeutic management of microbial diseases such as infectious skin diseases.
- Full Text:
- Date Issued: 2020
- Authors: Kambale, Espoir K , Nkanga, Christian I , Mutonkole, Blaise-Pascal I , Bapolisi, Alain M , Tassa, Daniel O , Liesse, Jean-Marie I , Krause, Rui W M , Memvanga, Patrick B
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193419 , vital:45330 , xlink:href="https://doi.org/10.1016/j.heliyon.2020.e04493"
- Description: In the present study, silver nanoparticles (AgNPs) were synthesized using aqueous leaf extracts of three Congolese plant species, namely Brillantaisia patula (BR-PA), Crossopteryx febrifuga (CR-FE) and Senna siamea (SE-SI). The obtained AgNPs were studied for their optical, structural, surface morphological and antibacterial properties. The prepared AgNPs were characterized by using UV-Visible spectra, Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray spectroscopy (EDX) and X-ray diffractometer (XRD). The synthesized nanoparticles were spherical shaped and well-dispersed with average sizes ranging from 45 to 110 nm. The AgNPs derived from BR-PA, CR-FE and SE-SI exhibited higher antibacterial activity against three bacterial pathogens of the human skin compared to their respective crude extracts and AgNO3. This indicated that the biomolecules covering the nanoparticles may enhance the biological activity of metal nanoparticles. Hence, our results support that biogenic synthesis of AgNPs from Congolese plants constitutes a potential area of interest for the therapeutic management of microbial diseases such as infectious skin diseases.
- Full Text:
- Date Issued: 2020
Ground-truthing climate-matching predictions in a post-release evaluation
- Muskett, Phillippa C, Paterson, Iain D, Coetzee, Julie A
- Authors: Muskett, Phillippa C , Paterson, Iain D , Coetzee, Julie A
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423504 , vital:72067 , xlink:href="https://doi.org/10.1016/j.biocontrol.2020.104217"
- Description: Pereskia aculeata Miller (Cactaceae) is an invasive alien cactus which has negative impacts on indigenous plant biodiversity in South Africa. Catorhintha schaffneri Barilovsky and Garcia (Coreidae), the pereskia stem-wilter, was collected at coastal sites in the subtropical region of Santa Catarina state in southern Brazil and released as a biological control agent to control P. aculeata, in South Africa, in 2014. The introduced distribution of P. aculeata covers a wide variety of climatic conditions which was expected to influence the establishment success of the new agent. The thermal tolerance of C. schaffneri was investigated by developing a degree-day model and calculating the thermal limits of the species. The influence of humidity on egg hatchability and adult survival was also investigated. These data were then used to determine where the agent was likely to establish in South Africa using both weather station and microclimate temperature data. To ground-truth these predictions, sixteen release sites were selected covering a wide range of climatic conditions in the introduced distribution. Three releases of 30 adult C. schaffneri were conducted at each site and population establishment was recorded. Field establishment was recorded at only two of the sixteen experimental release sites. Low winter temperatures were predicted to prevent establishment at seven of the sixteen sites, but nine sites were considered climatically suitable according to the agent’s thermal physiology. Low rainfall and humidity could explain why the agent did not survive at some sites with suitable thermal climates. Many of the thermally suitable sites were affected by a severe drought over the course of the experiment, so further releases during periods with average rainfall and humidity are warranted and could confirm whether the drought was a significant factor influencing the failure of the agent to establish. Although climatic-matching and thermal physiology studies are valuable for tentative predictions of establishment success, there are numerous variables involved that require ground-truthing. Releasing the agent over a wide range of climatic zones believed to be within the thermal limits of the agent, and following releases with detailed post-release evaluations may be the best method of determining where future releases should be focused.
- Full Text:
- Date Issued: 2020
- Authors: Muskett, Phillippa C , Paterson, Iain D , Coetzee, Julie A
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423504 , vital:72067 , xlink:href="https://doi.org/10.1016/j.biocontrol.2020.104217"
- Description: Pereskia aculeata Miller (Cactaceae) is an invasive alien cactus which has negative impacts on indigenous plant biodiversity in South Africa. Catorhintha schaffneri Barilovsky and Garcia (Coreidae), the pereskia stem-wilter, was collected at coastal sites in the subtropical region of Santa Catarina state in southern Brazil and released as a biological control agent to control P. aculeata, in South Africa, in 2014. The introduced distribution of P. aculeata covers a wide variety of climatic conditions which was expected to influence the establishment success of the new agent. The thermal tolerance of C. schaffneri was investigated by developing a degree-day model and calculating the thermal limits of the species. The influence of humidity on egg hatchability and adult survival was also investigated. These data were then used to determine where the agent was likely to establish in South Africa using both weather station and microclimate temperature data. To ground-truth these predictions, sixteen release sites were selected covering a wide range of climatic conditions in the introduced distribution. Three releases of 30 adult C. schaffneri were conducted at each site and population establishment was recorded. Field establishment was recorded at only two of the sixteen experimental release sites. Low winter temperatures were predicted to prevent establishment at seven of the sixteen sites, but nine sites were considered climatically suitable according to the agent’s thermal physiology. Low rainfall and humidity could explain why the agent did not survive at some sites with suitable thermal climates. Many of the thermally suitable sites were affected by a severe drought over the course of the experiment, so further releases during periods with average rainfall and humidity are warranted and could confirm whether the drought was a significant factor influencing the failure of the agent to establish. Although climatic-matching and thermal physiology studies are valuable for tentative predictions of establishment success, there are numerous variables involved that require ground-truthing. Releasing the agent over a wide range of climatic zones believed to be within the thermal limits of the agent, and following releases with detailed post-release evaluations may be the best method of determining where future releases should be focused.
- Full Text:
- Date Issued: 2020
Growth and photosynthetic responses of Acacia (Vachellia) seedlings to atmospheric CO2 increased from glacial to current concentrations: underlying mechanisms and ecological implications
- Authors: Anderson, Bruce Maurice
- Date: 2020
- Subjects: Acacia vachellia , Acacia vachellia -- Growth , Acacia -- South Africa
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/138182 , vital:37604
- Description: The African Acacia species Vachellia karroo, V. robusta, V. nilotica, and V. tortilis are some of the most invasive species implicated in bush encroachment and woody thickening of historically open savannas in southern Africa. This is partially explained by historic increases in atmospheric CO2 concentrations, which are proposed to have promoted the growth and survivorship of C3 tree seedlings relative to C4 grasses. However, the uniformity of CO2 responsiveness and differences among Vachellia species remain largely undetermined. Here we investigate the growth and photosynthetic responses of four Vachellia species, all implicated in woody encroachment, but originating from distinct climatic niches. Exposing these species to a range of sub-ambient CO2 concentrations (12 – 40 Pa) showed that V. karroo, V. robusta, V. nilotica and V. tortilis all responded strongly and fairly consistently to increasing CO2 concentrations, acting as a ‘functional type’ despite being selected from different geographic regions and having different climatic niches. Combined average net CO2 assimilation rates increased by 130% despite significant, but low levels of down-regulation and decreased stomatal conductance. The increased photosynthetic rates stimulated growth and biomass production in all compartments, with no significant differences in interspecific above and below ground allocation. Growth rates and dry biomass increased by 50% and 186%, respectively, while leaf level water use efficiency (ratio of net CO2 assimilation rate to transpiration rate) increased by an average of 218%. When this was scaled to the whole plant level, this stimulation was decreased to 80%. The decrease was the result of the CO2 stimulated increase in canopy areas, which increased leaf area for water loss. The seedlings’ total number of spinescent physical defenses, as well as the average mass and spine mass fraction also increased with rising CO2. These thicker spines could act as better deterrents against vertebrate browsers. Spine density was unchanged, however, showing that the increased spine numbers were associated with larger seedlings at higher CO2 rather than an increase in the number of spines per stem length. The stimulatory effects of increasing CO2 concentrations since the last glacial maximum and resultant increases in seedling growth and biomass are likely to have had important consequences for the survival and establishment of Acacia seedlings. Tolerance of drought and disturbance has been related to seedling size, hence stimulating the growth rate could confer disturbance tolerance and this tolerance would develop more rapidly with increasing CO2 concentrations. Furthermore, increased nitrogen and water use efficiency have the potential to support seedling establishment in environments where these resources would otherwise be limited at lower atmospheric CO2 concentrations. Resulting in a larger proportion of CO2 fertilization responsive woody seedlings surviving the seedling size classes, and persisting within historically open savannas. Where interspecific differences occurred they are likely to have arisen from adaptation to specific climates where these species are native and selection would have been driven by factors such climate, resource availability, levels of disturbance and competitive interactions. V. karroo had the highest growth rates and strong CO2 driven increases in biomass accumulation, despite having the lowest inherent photosynthetic rates. V. karroo also had the lowest increase in water use efficiency and high transpiration rates could potentially increase access to soil nutrients through mass flow. This species had the highest mean spine mass and showed significant increases in spine mass fraction at elevated CO2 concentrations, which may be important for deterring herbivores. V. robusta’s distribution to the mesic east coast of Africa suggests that water is an important limitation to its distribution. Hence, the CO2 stimulated increase in water use efficiency at both leaf and whole canopy level allows speculation that this may be an important driver of this species’ range expansion, which might continue if increasing levels of CO2 continue to promote water use efficiency. V. nilotica occupies a broad range of habitats, inhabiting large areas of the subtropics both north and south of the equator, with the strongest climatic correlates being the precipitation of the wettest quarter followed by high temperature seasonality. In response to increasing CO2, V. nilotica showed overall strong increases in growth, water use efficiency, and physical defenses. These responses may explain why V. nilotica has been such a successful encroacher in a broad range of habitats where limitations are likely to include multiple climatic factors and disturbances. V. tortilis has the widest distribution of all the species studied, covering broad ranges of Africa and only being excluded from the wettest parts of the equator and driest parts of the deserts. In these experiments this species showed the lowest biomass responsiveness to CO2, but had especially large increases in water use efficiency at both the leaf and canopy level. This may have been an important driver for this species’ encroachment into the more arid parts of its distribution, however this link will need to be verified with further experimentation.
- Full Text:
- Date Issued: 2020
- Authors: Anderson, Bruce Maurice
- Date: 2020
- Subjects: Acacia vachellia , Acacia vachellia -- Growth , Acacia -- South Africa
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/138182 , vital:37604
- Description: The African Acacia species Vachellia karroo, V. robusta, V. nilotica, and V. tortilis are some of the most invasive species implicated in bush encroachment and woody thickening of historically open savannas in southern Africa. This is partially explained by historic increases in atmospheric CO2 concentrations, which are proposed to have promoted the growth and survivorship of C3 tree seedlings relative to C4 grasses. However, the uniformity of CO2 responsiveness and differences among Vachellia species remain largely undetermined. Here we investigate the growth and photosynthetic responses of four Vachellia species, all implicated in woody encroachment, but originating from distinct climatic niches. Exposing these species to a range of sub-ambient CO2 concentrations (12 – 40 Pa) showed that V. karroo, V. robusta, V. nilotica and V. tortilis all responded strongly and fairly consistently to increasing CO2 concentrations, acting as a ‘functional type’ despite being selected from different geographic regions and having different climatic niches. Combined average net CO2 assimilation rates increased by 130% despite significant, but low levels of down-regulation and decreased stomatal conductance. The increased photosynthetic rates stimulated growth and biomass production in all compartments, with no significant differences in interspecific above and below ground allocation. Growth rates and dry biomass increased by 50% and 186%, respectively, while leaf level water use efficiency (ratio of net CO2 assimilation rate to transpiration rate) increased by an average of 218%. When this was scaled to the whole plant level, this stimulation was decreased to 80%. The decrease was the result of the CO2 stimulated increase in canopy areas, which increased leaf area for water loss. The seedlings’ total number of spinescent physical defenses, as well as the average mass and spine mass fraction also increased with rising CO2. These thicker spines could act as better deterrents against vertebrate browsers. Spine density was unchanged, however, showing that the increased spine numbers were associated with larger seedlings at higher CO2 rather than an increase in the number of spines per stem length. The stimulatory effects of increasing CO2 concentrations since the last glacial maximum and resultant increases in seedling growth and biomass are likely to have had important consequences for the survival and establishment of Acacia seedlings. Tolerance of drought and disturbance has been related to seedling size, hence stimulating the growth rate could confer disturbance tolerance and this tolerance would develop more rapidly with increasing CO2 concentrations. Furthermore, increased nitrogen and water use efficiency have the potential to support seedling establishment in environments where these resources would otherwise be limited at lower atmospheric CO2 concentrations. Resulting in a larger proportion of CO2 fertilization responsive woody seedlings surviving the seedling size classes, and persisting within historically open savannas. Where interspecific differences occurred they are likely to have arisen from adaptation to specific climates where these species are native and selection would have been driven by factors such climate, resource availability, levels of disturbance and competitive interactions. V. karroo had the highest growth rates and strong CO2 driven increases in biomass accumulation, despite having the lowest inherent photosynthetic rates. V. karroo also had the lowest increase in water use efficiency and high transpiration rates could potentially increase access to soil nutrients through mass flow. This species had the highest mean spine mass and showed significant increases in spine mass fraction at elevated CO2 concentrations, which may be important for deterring herbivores. V. robusta’s distribution to the mesic east coast of Africa suggests that water is an important limitation to its distribution. Hence, the CO2 stimulated increase in water use efficiency at both leaf and whole canopy level allows speculation that this may be an important driver of this species’ range expansion, which might continue if increasing levels of CO2 continue to promote water use efficiency. V. nilotica occupies a broad range of habitats, inhabiting large areas of the subtropics both north and south of the equator, with the strongest climatic correlates being the precipitation of the wettest quarter followed by high temperature seasonality. In response to increasing CO2, V. nilotica showed overall strong increases in growth, water use efficiency, and physical defenses. These responses may explain why V. nilotica has been such a successful encroacher in a broad range of habitats where limitations are likely to include multiple climatic factors and disturbances. V. tortilis has the widest distribution of all the species studied, covering broad ranges of Africa and only being excluded from the wettest parts of the equator and driest parts of the deserts. In these experiments this species showed the lowest biomass responsiveness to CO2, but had especially large increases in water use efficiency at both the leaf and canopy level. This may have been an important driver for this species’ encroachment into the more arid parts of its distribution, however this link will need to be verified with further experimentation.
- Full Text:
- Date Issued: 2020
Growth of centimeter scale carbon wires using in-liquid AC arc discharge:
- Jankowski, Krzysztof, Ostafin, Agnes, Tomasik, Mikolaj, Nyokong, Tebello, Britton, Jonathan
- Authors: Jankowski, Krzysztof , Ostafin, Agnes , Tomasik, Mikolaj , Nyokong, Tebello , Britton, Jonathan
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149956 , vital:38914 , https://0-doi.org.wam.seals.ac.za/10.1007/s42452-020-2881-2
- Description: A novel observation of the formation of carbon wire in a carbon-based liquid solvent, using in liquid high voltage AC arc discharge is described. The authors describe the observed phenomenon, technical equipment needed to achieve the effect and preliminary qualitative results of obtained material. The wire consisted of well packed layers of carbon elements. The arc-discharge method is a simple, low cost method for the production of three dimensional carbon structures. A further research is needed to get a thorough understanding of the phenomenon.
- Full Text:
- Date Issued: 2020
- Authors: Jankowski, Krzysztof , Ostafin, Agnes , Tomasik, Mikolaj , Nyokong, Tebello , Britton, Jonathan
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149956 , vital:38914 , https://0-doi.org.wam.seals.ac.za/10.1007/s42452-020-2881-2
- Description: A novel observation of the formation of carbon wire in a carbon-based liquid solvent, using in liquid high voltage AC arc discharge is described. The authors describe the observed phenomenon, technical equipment needed to achieve the effect and preliminary qualitative results of obtained material. The wire consisted of well packed layers of carbon elements. The arc-discharge method is a simple, low cost method for the production of three dimensional carbon structures. A further research is needed to get a thorough understanding of the phenomenon.
- Full Text:
- Date Issued: 2020
Guidelines for the use of machine learning to predict student project group academic performance
- Authors: Evezard, Ryan
- Date: 2020
- Subjects: Academic achievement , Machine learning
- Language: English
- Type: Thesis , Masters , MIT
- Identifier: http://hdl.handle.net/10948/46042 , vital:39476
- Description: Education plays a crucial role in the growth and development of a country. However, in South Africa, there is a limited capacity and an increasing demand of students seeking an education. In an attempt to address this demand, universities are pressured into accepting more students to increase their throughput. This pressure leads to educators having less time to give students individual attention. This study aims to address this problem by demonstrating how machine learning can be used to predict student group academic performance so that educators may allocate more resources and attention to students and groups at risk. The study focused on data obtained from the third-year capstone project for the diploma in Information Technology at the Nelson Mandela University. Learning analytics and educational data mining and their processes were discussed with an in-depth look at the machine learning techniques involved therein. Artificial neural networks, decision trees and naïve Bayes classifiers were proposed and motivated for prediction modelling. An experiment was performed resulting in proposed guidelines, which give insight and recommendations for the use of machine learning to predict student group academic performance.
- Full Text:
- Date Issued: 2020
- Authors: Evezard, Ryan
- Date: 2020
- Subjects: Academic achievement , Machine learning
- Language: English
- Type: Thesis , Masters , MIT
- Identifier: http://hdl.handle.net/10948/46042 , vital:39476
- Description: Education plays a crucial role in the growth and development of a country. However, in South Africa, there is a limited capacity and an increasing demand of students seeking an education. In an attempt to address this demand, universities are pressured into accepting more students to increase their throughput. This pressure leads to educators having less time to give students individual attention. This study aims to address this problem by demonstrating how machine learning can be used to predict student group academic performance so that educators may allocate more resources and attention to students and groups at risk. The study focused on data obtained from the third-year capstone project for the diploma in Information Technology at the Nelson Mandela University. Learning analytics and educational data mining and their processes were discussed with an in-depth look at the machine learning techniques involved therein. Artificial neural networks, decision trees and naïve Bayes classifiers were proposed and motivated for prediction modelling. An experiment was performed resulting in proposed guidelines, which give insight and recommendations for the use of machine learning to predict student group academic performance.
- Full Text:
- Date Issued: 2020
Guidelines for the user interface design of electronic medical records in optometry
- Authors: Nathoo, Dina
- Date: 2020
- Subjects: User interfaces (Computer systems) , Medical records -- Data processing , Optometry -- South Africa -- Eastern Cape , System design , Workflow management systems
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/148782 , vital:38773
- Description: With the prevalence of digitalisation in the medical industry, e-health systems have largely replaced the traditional paper-based recording methods. At the centre of these e-health systems are Electronic Health Records (EHRs) and Electronic Medical Records (EMRs), whose benefits significantly improve physician workflows. However, provision for user interface designs (UIDs) of these systems have been so poor that they have severely hindered physician usability, disrupted their workflows and risked patient safety. UID and usability guidelines have been provided, but have been very high level and general, mostly suitable for EHRs (which are used in general practices and hospitals). These guidelines have thus been ineffective in applicability for EMRs, which are typically used in niche medical environments. Within the niche field of Optometry, physicians experience disrupted workflows as a result of poor EMR UID and usability, of which EMR guidelines to improve these challenges are scarce. Hence, the need for this research arose, aiming to create UID guidelines for EMRs in Optometry, which will help improve the usability of the optometrists’ EMR. The main research question was successfully answered to produce the set of UID Guidelines for EMRs in Optometry, which includes guidelines built upon from literature and made contextually relevant, as well as some new additions, which are more patient focused. Design Science Research (DSR) was chosen as a suitable approach, and the phased Design Science Research Process Model (DSRPM) was used to guide this research. A literature review was conducted, including EHR and EMR, usability, UIDs, Optometry, related fields, and studies previously conducted to provide guidelines, frameworks and models. The review also included studying usability problems reported on the systems and the methods to overcome them. Task Analysis (TA) was used to observe and understand the optometrists’ workflows and their interactions with their EMRs during patient appointments, also identifying EMR problem areas. To address these problems, Focus Groups (FGs) were used to brainstorm solutions in the form of EMR UID features that optometrists’ required to improve their usability. From the literature review, TAs and FGs, proposed guidelines were created. The created guidelines informed the UID of an EMR prototype, which was successfully demonstrated to optometrists during Usability Testing sessions for the evaluation. Surveys were also used for the evaluation. The results proved the guidelines were successful, and were usable, effective, efficient and of good quality. A revised, final set of guidelines was then presented. Future researchers and designers may benefit from the contributions made from this research, which are both theoretical and practical.
- Full Text:
- Date Issued: 2020
- Authors: Nathoo, Dina
- Date: 2020
- Subjects: User interfaces (Computer systems) , Medical records -- Data processing , Optometry -- South Africa -- Eastern Cape , System design , Workflow management systems
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/148782 , vital:38773
- Description: With the prevalence of digitalisation in the medical industry, e-health systems have largely replaced the traditional paper-based recording methods. At the centre of these e-health systems are Electronic Health Records (EHRs) and Electronic Medical Records (EMRs), whose benefits significantly improve physician workflows. However, provision for user interface designs (UIDs) of these systems have been so poor that they have severely hindered physician usability, disrupted their workflows and risked patient safety. UID and usability guidelines have been provided, but have been very high level and general, mostly suitable for EHRs (which are used in general practices and hospitals). These guidelines have thus been ineffective in applicability for EMRs, which are typically used in niche medical environments. Within the niche field of Optometry, physicians experience disrupted workflows as a result of poor EMR UID and usability, of which EMR guidelines to improve these challenges are scarce. Hence, the need for this research arose, aiming to create UID guidelines for EMRs in Optometry, which will help improve the usability of the optometrists’ EMR. The main research question was successfully answered to produce the set of UID Guidelines for EMRs in Optometry, which includes guidelines built upon from literature and made contextually relevant, as well as some new additions, which are more patient focused. Design Science Research (DSR) was chosen as a suitable approach, and the phased Design Science Research Process Model (DSRPM) was used to guide this research. A literature review was conducted, including EHR and EMR, usability, UIDs, Optometry, related fields, and studies previously conducted to provide guidelines, frameworks and models. The review also included studying usability problems reported on the systems and the methods to overcome them. Task Analysis (TA) was used to observe and understand the optometrists’ workflows and their interactions with their EMRs during patient appointments, also identifying EMR problem areas. To address these problems, Focus Groups (FGs) were used to brainstorm solutions in the form of EMR UID features that optometrists’ required to improve their usability. From the literature review, TAs and FGs, proposed guidelines were created. The created guidelines informed the UID of an EMR prototype, which was successfully demonstrated to optometrists during Usability Testing sessions for the evaluation. Surveys were also used for the evaluation. The results proved the guidelines were successful, and were usable, effective, efficient and of good quality. A revised, final set of guidelines was then presented. Future researchers and designers may benefit from the contributions made from this research, which are both theoretical and practical.
- Full Text:
- Date Issued: 2020
Habitat requirements affect genetic variation in three species of mayfly (Ephemeroptera, Baetidae) from South Africa:
- Taylor, Chantal L, Barker, Nigel P, Barber-James, Helen M, Villet, Martin H, Pereira-da-Conceicoa, Lyndall L
- Authors: Taylor, Chantal L , Barker, Nigel P , Barber-James, Helen M , Villet, Martin H , Pereira-da-Conceicoa, Lyndall L
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149314 , vital:38824 , https://doi.org/10.3897/zookeys.936.38587
- Description: This study investigates genetic diversity in three species of Ephemeroptera, one eurytopic and therefore widespread (Afroptilum sudafricanum) and two stenotopic and thus endemic (Demoreptus natalensis and Demoreptus capensis) species, all of which co-occur in the southern Great Escarpment, South Africa. Mitochondrial DNA was analysed to compare the genetic diversity between the habitat generalist and the two habitat specialists. Afroptilum sudafricanum showed no indication of population genetic structure due to geographic location, while both Demoreptus species revealed clear genetic differentiation between geographic localities and catchments, evident from phylogenetic analyses and high FST values from AMOVA.
- Full Text:
- Date Issued: 2020
- Authors: Taylor, Chantal L , Barker, Nigel P , Barber-James, Helen M , Villet, Martin H , Pereira-da-Conceicoa, Lyndall L
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149314 , vital:38824 , https://doi.org/10.3897/zookeys.936.38587
- Description: This study investigates genetic diversity in three species of Ephemeroptera, one eurytopic and therefore widespread (Afroptilum sudafricanum) and two stenotopic and thus endemic (Demoreptus natalensis and Demoreptus capensis) species, all of which co-occur in the southern Great Escarpment, South Africa. Mitochondrial DNA was analysed to compare the genetic diversity between the habitat generalist and the two habitat specialists. Afroptilum sudafricanum showed no indication of population genetic structure due to geographic location, while both Demoreptus species revealed clear genetic differentiation between geographic localities and catchments, evident from phylogenetic analyses and high FST values from AMOVA.
- Full Text:
- Date Issued: 2020
Heat dissipation behaviour of birds in seasonally hot arid‐zones: are there global patterns?
- Pattinson, Nicholas B, Thompson, Michelle L, Griego, Michael, Russell, Grace, Mitchell, Nicola J, Martin, Rowan O, Wolf, Blair O, Smit, Ben, Cunningham, Susan J, McKechnie, Andrew, Hockey, Philip A R
- Authors: Pattinson, Nicholas B , Thompson, Michelle L , Griego, Michael , Russell, Grace , Mitchell, Nicola J , Martin, Rowan O , Wolf, Blair O , Smit, Ben , Cunningham, Susan J , McKechnie, Andrew , Hockey, Philip A R
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441682 , vital:73906 , https://doi.org/10.1111/jav.02350
- Description: Quantifying organismal sensitivity to heat stress provides one means for predicting vulnerability to climate change. Birds are ideal for investigating this approach, as they display quantifiable fitness consequences associated with behavioural and physiological responses to heat stress. We used a recently developed method that examines correlations between readily‐observable behaviours and air temperature (Tair) to investigate interspecific variation in avian responses to heat stress in seasonally hot, arid regions on three continents: the southwestern United States, the Kalahari Desert of southern Africa and the Gascoyne region of western Australia.
- Full Text:
- Date Issued: 2020
- Authors: Pattinson, Nicholas B , Thompson, Michelle L , Griego, Michael , Russell, Grace , Mitchell, Nicola J , Martin, Rowan O , Wolf, Blair O , Smit, Ben , Cunningham, Susan J , McKechnie, Andrew , Hockey, Philip A R
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441682 , vital:73906 , https://doi.org/10.1111/jav.02350
- Description: Quantifying organismal sensitivity to heat stress provides one means for predicting vulnerability to climate change. Birds are ideal for investigating this approach, as they display quantifiable fitness consequences associated with behavioural and physiological responses to heat stress. We used a recently developed method that examines correlations between readily‐observable behaviours and air temperature (Tair) to investigate interspecific variation in avian responses to heat stress in seasonally hot, arid regions on three continents: the southwestern United States, the Kalahari Desert of southern Africa and the Gascoyne region of western Australia.
- Full Text:
- Date Issued: 2020
Hegemon and handmaiden: a neo-gramscian approach to South Africa’s position in the global political economy
- Authors: Koza, Zintle
- Date: 2020
- Subjects: Hegemony
- Language: English
- Type: Thesis , Masters , MSoc (Political Science)
- Identifier: http://hdl.handle.net/10353/18325 , vital:42252
- Description: Despite its assumed leadership of and investment in the African Union (AU) and the Southern African Development Community (SADC), South Africa has not developed its own hegemonic project and is consequently unable to exert significant influence over the ideas of the two institutions. Rooted in Antonio Gramsci’s absolute historicism, which locates decisions and actions at the level of the state within specific contexts, Robert Cox’s Method of Historical Structures (MHS) offers a framework that enables an approach informed by Critical Theory to analysing and empirically understanding the underlying factors of this situation. Utilising the three elements of the MHS, namely, material capabilities, ideas and institutions, and applying them to the context of international relations, it was found that South Africa’s choices have been informed by the global context of the post-USSR global arena it entered in 1990. The triumph of the neoliberal world order led by the United States framed the context of South Africa’s engagement with Africa and the world, with its choices informed by a composite of neoliberally defined global social relations of production and ideas that had already elicited global consent. South Africa’s organisation of material capabilities and resources was thus limited within the parameters of a neoliberal world order, and the predominance of institutions that facilitated the penetration of neoliberalism, regionally and globally. The global hegemonic order relies on surrogates for its functioning and South Africa’s subsequent domestic adherence to the hegemonic neoliberal order has been transferred to SADC and, to a limited extent, to the AU through the policies and institutional projects that South Africa has championed since 1994. Nonetheless, in the face of persistent inequality and poverty, internal contestation to this adherence has emanated from trade unions and civil society organisations. It was found that the continued and intensifying domestic contestation iii reinforces the lack of a domestic hegemonic project that could have been projected externally to SADC and the AU, so that South Africa, as a dominant peripheral state in the global world order, displays more characteristics of handmaiden than hegemon.
- Full Text:
- Date Issued: 2020
- Authors: Koza, Zintle
- Date: 2020
- Subjects: Hegemony
- Language: English
- Type: Thesis , Masters , MSoc (Political Science)
- Identifier: http://hdl.handle.net/10353/18325 , vital:42252
- Description: Despite its assumed leadership of and investment in the African Union (AU) and the Southern African Development Community (SADC), South Africa has not developed its own hegemonic project and is consequently unable to exert significant influence over the ideas of the two institutions. Rooted in Antonio Gramsci’s absolute historicism, which locates decisions and actions at the level of the state within specific contexts, Robert Cox’s Method of Historical Structures (MHS) offers a framework that enables an approach informed by Critical Theory to analysing and empirically understanding the underlying factors of this situation. Utilising the three elements of the MHS, namely, material capabilities, ideas and institutions, and applying them to the context of international relations, it was found that South Africa’s choices have been informed by the global context of the post-USSR global arena it entered in 1990. The triumph of the neoliberal world order led by the United States framed the context of South Africa’s engagement with Africa and the world, with its choices informed by a composite of neoliberally defined global social relations of production and ideas that had already elicited global consent. South Africa’s organisation of material capabilities and resources was thus limited within the parameters of a neoliberal world order, and the predominance of institutions that facilitated the penetration of neoliberalism, regionally and globally. The global hegemonic order relies on surrogates for its functioning and South Africa’s subsequent domestic adherence to the hegemonic neoliberal order has been transferred to SADC and, to a limited extent, to the AU through the policies and institutional projects that South Africa has championed since 1994. Nonetheless, in the face of persistent inequality and poverty, internal contestation to this adherence has emanated from trade unions and civil society organisations. It was found that the continued and intensifying domestic contestation iii reinforces the lack of a domestic hegemonic project that could have been projected externally to SADC and the AU, so that South Africa, as a dominant peripheral state in the global world order, displays more characteristics of handmaiden than hegemon.
- Full Text:
- Date Issued: 2020
High genetic diversity and limited spatial structure in an endangered, endemic South African sparid, the red steenbras Petrus rupestris:
- Gouws, Gavin, Kerwath, S E, Potts, Warren M, James, Nicola C, Vine, Niall G, Cowley, Paul D
- Authors: Gouws, Gavin , Kerwath, S E , Potts, Warren M , James, Nicola C , Vine, Niall G , Cowley, Paul D
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160379 , vital:40440 , DOI: 10.2989/1814232X.2020.1788640
- Description: The red steenbras Petrus rupestris is endemic to South Africa, occurring from False Bay in the Western Cape Province to St Lucia in the province of KwaZulu-Natal. This species, the largest member of the family Sparidae, has undergone a substantial stock decline as a result of overfishing and is considered to be collapsed. Various aspects of its life history, including high residency, predictable migrations, late maturity and longevity, have made it vulnerable to overexploitation. This study analysed the diversity and genetic structure of red steenbras across seven sampling regions, using mitochondrial (control region) and nuclear (S7 intron 1) DNA markers.
- Full Text:
- Date Issued: 2020
- Authors: Gouws, Gavin , Kerwath, S E , Potts, Warren M , James, Nicola C , Vine, Niall G , Cowley, Paul D
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160379 , vital:40440 , DOI: 10.2989/1814232X.2020.1788640
- Description: The red steenbras Petrus rupestris is endemic to South Africa, occurring from False Bay in the Western Cape Province to St Lucia in the province of KwaZulu-Natal. This species, the largest member of the family Sparidae, has undergone a substantial stock decline as a result of overfishing and is considered to be collapsed. Various aspects of its life history, including high residency, predictable migrations, late maturity and longevity, have made it vulnerable to overexploitation. This study analysed the diversity and genetic structure of red steenbras across seven sampling regions, using mitochondrial (control region) and nuclear (S7 intron 1) DNA markers.
- Full Text:
- Date Issued: 2020
High genetic diversity and limited spatial structure in an endangered, endemic South African sparid, the red steenbras Petrus rupestris:
- Tang, Wei, Qiu, Yuanyuan, Li, Xiaonan, Soy, Rodah C, Mack, John, Nyokong, Tebello
- Authors: Tang, Wei , Qiu, Yuanyuan , Li, Xiaonan , Soy, Rodah C , Mack, John , Nyokong, Tebello
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160390 , vital:40441 , DOI: 10.6060/mhc200183l
- Description: Earth-abundant first row transition metal corrole complexes have played an important role in fundamental research due to their unique molecular structures and attractive properties. In comparison to porphyrins, corroles have three inner N-H protons and are ring-contracted with a smaller macrocyclic cavity. First row transition metal corroles have been widely used as effective electrochemical catalysts for small molecule activations, such as hydrogen evolution, oxygen reduction/evolution and CO2 reduction reactions (HERs, ORRs/OERs and CO2 RRs) through homogenous and/or heterogenous prodecures. Several strategies have been used to modulate the catalytic efficiency of synthetic metallocorroles.
- Full Text:
- Date Issued: 2020
- Authors: Tang, Wei , Qiu, Yuanyuan , Li, Xiaonan , Soy, Rodah C , Mack, John , Nyokong, Tebello
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160390 , vital:40441 , DOI: 10.6060/mhc200183l
- Description: Earth-abundant first row transition metal corrole complexes have played an important role in fundamental research due to their unique molecular structures and attractive properties. In comparison to porphyrins, corroles have three inner N-H protons and are ring-contracted with a smaller macrocyclic cavity. First row transition metal corroles have been widely used as effective electrochemical catalysts for small molecule activations, such as hydrogen evolution, oxygen reduction/evolution and CO2 reduction reactions (HERs, ORRs/OERs and CO2 RRs) through homogenous and/or heterogenous prodecures. Several strategies have been used to modulate the catalytic efficiency of synthetic metallocorroles.
- Full Text:
- Date Issued: 2020
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
History on trial: a study of the Salem commonage land claim
- Authors: Bezuidenhout, GJW
- Date: 2020
- Subjects: South Africa. Restitution of Land Rights Act, 1994 , Salem (South Africa) -- History , Land tenure -- Law and legilstion -- South Africa , Land reform -- Law and legislation -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146647 , vital:38545
- Description: This thesis critically examines the Salem commonage claim, a dispute that has shaken the hamlet of Salem to its core. On ground level it has caused racialized fault lines to reopen, while suspicion and distrust has also grown between the black Africans of the area as well. On a national level, the Constitutional Court judgement has potentially set a precedent with regards to its jurisprudential approach in determining the validity of land claims in South Africa. Its interpretation of the law was determined by the restorative justice jurisprudence enshrined in the Restitution of Land Rights Act 22 of 1994 (the Act). It based its own understanding of the history of the commonage on this jurisprudence. In a bold step towards realising the aims and purposes of the Act, the Constitutional Court found that both the black African claimants as well as the white landowners have equal rights to the land. One of the reasons why the decision of the Constitutional Court is ground-breaking is that the dispute involves a former commonage – land used for common purpose. The Constitutional Court emphasised that the Act was an “extraordinary piece of legislation” and had to be interpreted in such a way so as to address the injustices of the past. This included provisions of the Act which dealt with how oral testimonies from claimants would be dealt with. Another interesting feature was the heavy reliance by all parties on expert witnesses in the persons of eminent historians, Professors Martin Legassick and Herman Giliomee. This case gave much-needed clarification as to what the appropriate role of an expert historian witness may be in a land claim. The success or failure of land claims often depend on the weight of the evidence supplied by the expert historian witness. But the historian must also take cognisance of the fact that the evidence s/he gives is appropriate according to the scope of law. This case also dismisses the assumption that colonial instruments of land assignation are beyond reproach. These instruments which grant rights to land may also be scrutinised in a court of law, just like when oral testimony is tested for its credibility. This is important to note, especially when balancing land rights of the claimants against those of the landowners. This thesis agrees with the decision taken by the Constitutional Court in this instance. However, it also cautions that such softly-softly approaches may appear as a suitable compromise on paper, but the feeling on the ground may not be as receptive to reconciliation as what the courts would have hoped for. To the jurist, this judgement accurately encapsulates the purpose and aims of the Act. However, such a judgement may not seem satisfactory to the people of Salem. The decisions of the Salem commonage case are sure to inform the discourse of land claims in South Africa.
- Full Text:
- Date Issued: 2020
- Authors: Bezuidenhout, GJW
- Date: 2020
- Subjects: South Africa. Restitution of Land Rights Act, 1994 , Salem (South Africa) -- History , Land tenure -- Law and legilstion -- South Africa , Land reform -- Law and legislation -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146647 , vital:38545
- Description: This thesis critically examines the Salem commonage claim, a dispute that has shaken the hamlet of Salem to its core. On ground level it has caused racialized fault lines to reopen, while suspicion and distrust has also grown between the black Africans of the area as well. On a national level, the Constitutional Court judgement has potentially set a precedent with regards to its jurisprudential approach in determining the validity of land claims in South Africa. Its interpretation of the law was determined by the restorative justice jurisprudence enshrined in the Restitution of Land Rights Act 22 of 1994 (the Act). It based its own understanding of the history of the commonage on this jurisprudence. In a bold step towards realising the aims and purposes of the Act, the Constitutional Court found that both the black African claimants as well as the white landowners have equal rights to the land. One of the reasons why the decision of the Constitutional Court is ground-breaking is that the dispute involves a former commonage – land used for common purpose. The Constitutional Court emphasised that the Act was an “extraordinary piece of legislation” and had to be interpreted in such a way so as to address the injustices of the past. This included provisions of the Act which dealt with how oral testimonies from claimants would be dealt with. Another interesting feature was the heavy reliance by all parties on expert witnesses in the persons of eminent historians, Professors Martin Legassick and Herman Giliomee. This case gave much-needed clarification as to what the appropriate role of an expert historian witness may be in a land claim. The success or failure of land claims often depend on the weight of the evidence supplied by the expert historian witness. But the historian must also take cognisance of the fact that the evidence s/he gives is appropriate according to the scope of law. This case also dismisses the assumption that colonial instruments of land assignation are beyond reproach. These instruments which grant rights to land may also be scrutinised in a court of law, just like when oral testimony is tested for its credibility. This is important to note, especially when balancing land rights of the claimants against those of the landowners. This thesis agrees with the decision taken by the Constitutional Court in this instance. However, it also cautions that such softly-softly approaches may appear as a suitable compromise on paper, but the feeling on the ground may not be as receptive to reconciliation as what the courts would have hoped for. To the jurist, this judgement accurately encapsulates the purpose and aims of the Act. However, such a judgement may not seem satisfactory to the people of Salem. The decisions of the Salem commonage case are sure to inform the discourse of land claims in South Africa.
- Full Text:
- Date Issued: 2020
Holistic nursing in practice: mindfulness-based yoga as an intervention to manage stress and burnout
- Hilcove, Kelly, Marceau, Catherine, Thekdi, Prachi, Larkey, Linda, Brewer, Melanie A, Jones, Kerry
- Authors: Hilcove, Kelly , Marceau, Catherine , Thekdi, Prachi , Larkey, Linda , Brewer, Melanie A , Jones, Kerry
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149336 , vital:38826 , https://0-doi.org.wam.seals.ac.za/10.1177/0898010120921587
- Description: Effects of a mindfulness-based (MB) yoga practice on stress, burnout, and indicators of well-being among nurses and health care professionals (HCPs).
- Full Text:
- Date Issued: 2020
Holistic nursing in practice: mindfulness-based yoga as an intervention to manage stress and burnout
- Authors: Hilcove, Kelly , Marceau, Catherine , Thekdi, Prachi , Larkey, Linda , Brewer, Melanie A , Jones, Kerry
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149336 , vital:38826 , https://0-doi.org.wam.seals.ac.za/10.1177/0898010120921587
- Description: Effects of a mindfulness-based (MB) yoga practice on stress, burnout, and indicators of well-being among nurses and health care professionals (HCPs).
- Full Text:
- Date Issued: 2020
Hop depletion reduces HSF1 levels and activity and coincides with reduced stress resilience:
- Chakraborty, Abantika, Edkins, Adrienne L
- Authors: Chakraborty, Abantika , Edkins, Adrienne L
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165440 , vital:41244 , https://doi.org/10.1016/j.bbrc.2020.04.072
- Description: Heat-shock factor 1 (HSF1) regulates the transcriptional response to stress and controls expression of molecular chaperones required for cell survival. Here we report that HSF1 is regulated by the abundance of the Hsp70-Hsp90 organizing protein (Hop/STIP1).
- Full Text:
- Date Issued: 2020
- Authors: Chakraborty, Abantika , Edkins, Adrienne L
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165440 , vital:41244 , https://doi.org/10.1016/j.bbrc.2020.04.072
- Description: Heat-shock factor 1 (HSF1) regulates the transcriptional response to stress and controls expression of molecular chaperones required for cell survival. Here we report that HSF1 is regulated by the abundance of the Hsp70-Hsp90 organizing protein (Hop/STIP1).
- 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
Host stage preference and performance of Dolichogenidea gelechiidivoris (Hymenoptera: Braconidae), a candidate for classical biological control of Tuta absoluta in Africa
- Aigbedion-Atalor, Pascal O, Mohamed, Samira A, Hill, Martin P, Zalucki, Myron P, Azrag, Abdelmutalab G A, Srinivasan, Ramasamy, Ekesi, Sunday
- Authors: Aigbedion-Atalor, Pascal O , Mohamed, Samira A , Hill, Martin P , Zalucki, Myron P , Azrag, Abdelmutalab G A , Srinivasan, Ramasamy , Ekesi, Sunday
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423516 , vital:72068 , xlink:href="https://doi.org/10.1016/j.biocontrol.2020.104215"
- Description: Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is native to South America but has invaded the Afro-Eurasian supercontinent where it is currently the most devastating invasive arthropod pest of tomato. As a part of the first classical biological control programme against T. absoluta in Africa, a larval parasitoid, Dolichogenidea gelechiidivoris Marsh. (Syn.: Apanteles gelechiidivoris Marsh) (Hymenoptera: Braconidae), of T. absoluta was imported from Peru into the quarantine facility of the International Centre of Insect Physiology and Ecology, Kenya. We report on the host larval preference of D. gelechiidivoris and the host suitability, and the parasitoid’s reproductive strategy, including lifetime fecundity and egg maturation dynamics. Dolichogenidea gelechiidivoris females preferentially oviposited in early (1st and 2nd) larval instars of T. absoluta but parasitized and completed development in all four instars of the host. Host instar did not affect D. gelechiidivoris sex-ratio but females reared on the first instar had significantly fewer eggs than when reared in late larval instars (3rd and 4th). Females of the parasitoid emerged with a high mature egg load which peaked 2 d post eclosion. The females of D. gelechiidivoris survived 8.51 ± 0.65 d and produced 103 ± 8 offspring per female at 26 ± 4 °C (range: 24 to 29 °C) and 50–70% relative humidity (RH) with males present and fed honey-water (80% honey). Increasing maternal age decreased the proportion of female offspring. Under the aforementioned laboratory conditions, the Gross and Net reproductive rates were 72 and 39.5 respectively, while the mean generation time was 20 d. The potential intrinsic rate of natural increase was 0.18. This study shows that D. gelechiidivoris is a potential biological control agent of T. absoluta and should be considered for release in Kenya and across Africa following host specificity testing and risk assessments.
- Full Text:
- Date Issued: 2020
- Authors: Aigbedion-Atalor, Pascal O , Mohamed, Samira A , Hill, Martin P , Zalucki, Myron P , Azrag, Abdelmutalab G A , Srinivasan, Ramasamy , Ekesi, Sunday
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423516 , vital:72068 , xlink:href="https://doi.org/10.1016/j.biocontrol.2020.104215"
- Description: Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is native to South America but has invaded the Afro-Eurasian supercontinent where it is currently the most devastating invasive arthropod pest of tomato. As a part of the first classical biological control programme against T. absoluta in Africa, a larval parasitoid, Dolichogenidea gelechiidivoris Marsh. (Syn.: Apanteles gelechiidivoris Marsh) (Hymenoptera: Braconidae), of T. absoluta was imported from Peru into the quarantine facility of the International Centre of Insect Physiology and Ecology, Kenya. We report on the host larval preference of D. gelechiidivoris and the host suitability, and the parasitoid’s reproductive strategy, including lifetime fecundity and egg maturation dynamics. Dolichogenidea gelechiidivoris females preferentially oviposited in early (1st and 2nd) larval instars of T. absoluta but parasitized and completed development in all four instars of the host. Host instar did not affect D. gelechiidivoris sex-ratio but females reared on the first instar had significantly fewer eggs than when reared in late larval instars (3rd and 4th). Females of the parasitoid emerged with a high mature egg load which peaked 2 d post eclosion. The females of D. gelechiidivoris survived 8.51 ± 0.65 d and produced 103 ± 8 offspring per female at 26 ± 4 °C (range: 24 to 29 °C) and 50–70% relative humidity (RH) with males present and fed honey-water (80% honey). Increasing maternal age decreased the proportion of female offspring. Under the aforementioned laboratory conditions, the Gross and Net reproductive rates were 72 and 39.5 respectively, while the mean generation time was 20 d. The potential intrinsic rate of natural increase was 0.18. This study shows that D. gelechiidivoris is a potential biological control agent of T. absoluta and should be considered for release in Kenya and across Africa following host specificity testing and risk assessments.
- 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
Household food insecurity and its association with psychological well-being of pregnant women in Ghana: the role of selected psychosocial factors
- Authors: Addai, Prince
- Date: 2020
- Subjects: Food security -- Ghana Households -- Ghana Self-reliance
- Language: English
- Type: Thesis , Doctoral , PhD (Industrial Psychology)
- Identifier: http://hdl.handle.net/10353/12547 , vital:39286
- Description: The inability to get enough food has contributed immensely to dangers confronting pregnant women, especially in the developing countries. Food insecurity has been associated with a variety of negative consequences such as poor health and wellbeing. However, the impact of food insecurity on well-being has not received the needed attention by researchers in Sub-Saharan Africa where the state of food insecurity and its consequence is very pandemic. The objective of this study was to assess the impact of food insecurity on psychological well-being and its components among pregnant women in Northern Ghana and to assess the roles of self-esteem, locus of control, proactivity, and social support on the underlying relationship. The cross-sectional survey was adopted where 386 pregnant women were recruited to complete questionnaires on demographic, some psychological factors, psychological well-being and food insecurity. Dimensionality and Item analyses were conducted to detect complex and poor items and also to ensure unidimensionality. Regression analysis, MANOVA, Baron and Kenney Model of moderation and mediation, the multivariate ANOVA and the Two-way ANOVA were used to test the hypotheses. Results indicated that the measurement and the structural models showed a good fit with the observed data. Results showed that about 37.5% (n=144) out of the 384 pregnant women experienced severe food insecurity. Food insecurity was negatively significantly related with psychological well-being and all its components among pregnant women. Food insecurity elucidated 48.5% of the observed variance of food insecurity. Food insecurity correlated highly to personal growth (β = -.327) element of psychological well-being compared to autonomy (β = -.227), interpersonal relationship (β = -.207), environmental mastery (β = -.168), self-acceptance (β = -.117), and of purpose in life (β = -.107). Self-esteem and locus of control mediated the relationship between food insecurity and psychological well-being. Proactivity and social support also moderated the nexus between food insecurity and psychological well-being. 4 Final Submission of Thesis, Dissertation or Research Report/Project, Conference or Exam Paper Having higher income status and being employed were associated positively with higher psychological well-being. Support was not found for the nexus between marital status and age with psychological well-being. Recommendations are made for pregnant mothers to be supported and empowered to boost their self-esteem and make them proactive.
- Full Text:
- Date Issued: 2020
- Authors: Addai, Prince
- Date: 2020
- Subjects: Food security -- Ghana Households -- Ghana Self-reliance
- Language: English
- Type: Thesis , Doctoral , PhD (Industrial Psychology)
- Identifier: http://hdl.handle.net/10353/12547 , vital:39286
- Description: The inability to get enough food has contributed immensely to dangers confronting pregnant women, especially in the developing countries. Food insecurity has been associated with a variety of negative consequences such as poor health and wellbeing. However, the impact of food insecurity on well-being has not received the needed attention by researchers in Sub-Saharan Africa where the state of food insecurity and its consequence is very pandemic. The objective of this study was to assess the impact of food insecurity on psychological well-being and its components among pregnant women in Northern Ghana and to assess the roles of self-esteem, locus of control, proactivity, and social support on the underlying relationship. The cross-sectional survey was adopted where 386 pregnant women were recruited to complete questionnaires on demographic, some psychological factors, psychological well-being and food insecurity. Dimensionality and Item analyses were conducted to detect complex and poor items and also to ensure unidimensionality. Regression analysis, MANOVA, Baron and Kenney Model of moderation and mediation, the multivariate ANOVA and the Two-way ANOVA were used to test the hypotheses. Results indicated that the measurement and the structural models showed a good fit with the observed data. Results showed that about 37.5% (n=144) out of the 384 pregnant women experienced severe food insecurity. Food insecurity was negatively significantly related with psychological well-being and all its components among pregnant women. Food insecurity elucidated 48.5% of the observed variance of food insecurity. Food insecurity correlated highly to personal growth (β = -.327) element of psychological well-being compared to autonomy (β = -.227), interpersonal relationship (β = -.207), environmental mastery (β = -.168), self-acceptance (β = -.117), and of purpose in life (β = -.107). Self-esteem and locus of control mediated the relationship between food insecurity and psychological well-being. Proactivity and social support also moderated the nexus between food insecurity and psychological well-being. 4 Final Submission of Thesis, Dissertation or Research Report/Project, Conference or Exam Paper Having higher income status and being employed were associated positively with higher psychological well-being. Support was not found for the nexus between marital status and age with psychological well-being. Recommendations are made for pregnant mothers to be supported and empowered to boost their self-esteem and make them proactive.
- 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