Enhanced upconversion emission of Er3+-Yb3+ co-doped Ba5 (PO4) 3OH powder phosphor for application in photodynamic therapy
- Mokoena, Puseletso P, Poluwole, David O, Nyokong, Tebello, Swart, Hendrik C, Ntwaeaborwa, Odireleng M
- Authors: Mokoena, Puseletso P , Poluwole, David O , Nyokong, Tebello , Swart, Hendrik C , Ntwaeaborwa, Odireleng M
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185035 , vital:44318 , xlink:href="https://doi.org/10.1016/j.sna.2021.113014"
- Description: Er3+-Yb3+ co-doped Ba5(PO4)3OH nanoparticle powder phosphors were successfully synthesized by urea combustion method. The resulting powder phosphors were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), high resolution scanning electron microscopy (HRSEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and photoluminescence spectroscopy (PL). XRD data confirmed crystallization of pure hexagonal phase of Ba5(PO4)3OH and HRSEM images showed formation of ellipsoidal particles. XPS data combined with EDS analysis confirmed the materials composition that corresponds with identification of all the chemical elements constituting the materials. The in vitro dark cytotoxicity of the particles confirmed lack of cytocidal behaviour in the absence of light, but considerable photodynamic therapy (PDT) activity was observed upon illumination. Upon excitation using a 980 nm laser, multiple emission peaks in the green and red regions corresponding to the optical transitions of Er3+ ion were observed. Upon co-doping with Yb3+, upconverted red emission was detected and this was attributable to non-radiative energy transfer from Yb3+ to Er3+. The proposed mechanism of upconversion photoluminescence is discussed.
- Full Text:
- Date Issued: 2021
- Authors: Mokoena, Puseletso P , Poluwole, David O , Nyokong, Tebello , Swart, Hendrik C , Ntwaeaborwa, Odireleng M
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185035 , vital:44318 , xlink:href="https://doi.org/10.1016/j.sna.2021.113014"
- Description: Er3+-Yb3+ co-doped Ba5(PO4)3OH nanoparticle powder phosphors were successfully synthesized by urea combustion method. The resulting powder phosphors were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), high resolution scanning electron microscopy (HRSEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and photoluminescence spectroscopy (PL). XRD data confirmed crystallization of pure hexagonal phase of Ba5(PO4)3OH and HRSEM images showed formation of ellipsoidal particles. XPS data combined with EDS analysis confirmed the materials composition that corresponds with identification of all the chemical elements constituting the materials. The in vitro dark cytotoxicity of the particles confirmed lack of cytocidal behaviour in the absence of light, but considerable photodynamic therapy (PDT) activity was observed upon illumination. Upon excitation using a 980 nm laser, multiple emission peaks in the green and red regions corresponding to the optical transitions of Er3+ ion were observed. Upon co-doping with Yb3+, upconverted red emission was detected and this was attributable to non-radiative energy transfer from Yb3+ to Er3+. The proposed mechanism of upconversion photoluminescence is discussed.
- Full Text:
- Date Issued: 2021
Enhancement of Biological and Pharmacological Properties of an Encapsulated Polyphenol: Curcumin
- Witika, Bwalya A, Makoni, Pedzisai A, Matafwali, Scott K, Mweetwa, Larry L, Shandele, Ginnethon C, Walker, Roderick B
- Authors: Witika, Bwalya A , Makoni, Pedzisai A , Matafwali, Scott K , Mweetwa, Larry L , Shandele, Ginnethon C , Walker, Roderick B
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183161 , vital:43917 , xlink:href="https://doi.org/10.3390/molecules26144244"
- Description: There is a dearth of natural remedies available for the treatment of an increasing number of diseases facing mankind. Natural products may provide an opportunity to produce formulations and therapeutic solutions to address this shortage. Curcumin (CUR), diferuloylmethane; I,7-bis-(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione is the major pigment in turmeric powder which has been reported to exhibit a number of health benefits including, antibacterial, antiviral, anti-cancer, anti-inflammatory and anti-oxidant properties. In this review, the authors attempt to highlight the biological and pharmacological properties of CUR in addition to emphasizing aspects relating to the biosynthesis, encapsulation and therapeutic effects of the compound. The information contained in this review was generated by considering published information in which evidence of enhanced biological and pharmacological properties of nano-encapsulated CUR was reported. CUR has contributed to a significant improvement in melanoma, breast, lung, gastro-intestinal, and genito-urinary cancer therapy. We highlight the impact of nano-encapsulated CUR for efficient inhibition of cell proliferation, even at low concentrations compared to the free CUR when considering anti-proliferation. Furthermore nano-encapsulated CUR exhibited bioactive properties, exerted cytotoxic and anti-oxidant effects by acting on endogenous and cholinergic anti-oxidant systems. CUR was reported to block Hepatitis C virus (HCV) entry into hepatic cells, inhibit MRSA proliferation, enhance wound healing and reduce bacterial load. Nano-encapsulated CUR has also shown bioactive properties when acting on antioxidant systems (endogenous and cholinergic). Future research is necessary and must focus on investigation of encapsulated CUR nano-particles in different models of human pathology.
- Full Text:
- Date Issued: 2021
- Authors: Witika, Bwalya A , Makoni, Pedzisai A , Matafwali, Scott K , Mweetwa, Larry L , Shandele, Ginnethon C , Walker, Roderick B
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183161 , vital:43917 , xlink:href="https://doi.org/10.3390/molecules26144244"
- Description: There is a dearth of natural remedies available for the treatment of an increasing number of diseases facing mankind. Natural products may provide an opportunity to produce formulations and therapeutic solutions to address this shortage. Curcumin (CUR), diferuloylmethane; I,7-bis-(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione is the major pigment in turmeric powder which has been reported to exhibit a number of health benefits including, antibacterial, antiviral, anti-cancer, anti-inflammatory and anti-oxidant properties. In this review, the authors attempt to highlight the biological and pharmacological properties of CUR in addition to emphasizing aspects relating to the biosynthesis, encapsulation and therapeutic effects of the compound. The information contained in this review was generated by considering published information in which evidence of enhanced biological and pharmacological properties of nano-encapsulated CUR was reported. CUR has contributed to a significant improvement in melanoma, breast, lung, gastro-intestinal, and genito-urinary cancer therapy. We highlight the impact of nano-encapsulated CUR for efficient inhibition of cell proliferation, even at low concentrations compared to the free CUR when considering anti-proliferation. Furthermore nano-encapsulated CUR exhibited bioactive properties, exerted cytotoxic and anti-oxidant effects by acting on endogenous and cholinergic anti-oxidant systems. CUR was reported to block Hepatitis C virus (HCV) entry into hepatic cells, inhibit MRSA proliferation, enhance wound healing and reduce bacterial load. Nano-encapsulated CUR has also shown bioactive properties when acting on antioxidant systems (endogenous and cholinergic). Future research is necessary and must focus on investigation of encapsulated CUR nano-particles in different models of human pathology.
- Full Text:
- Date Issued: 2021
Enhancing Capabilities of Life Sciences Teachers: Professional Development, Conversion Factors and Functionings in Teachers’ Professional Learning Communities
- Tshiningayamwe, Sirkka, Lotz-Sisitka, Heila
- Authors: Tshiningayamwe, Sirkka , Lotz-Sisitka, Heila
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/435220 , vital:73139 , ISBN 9781928502241 , https://library.oapen.org/handle/20.500.12657/64082
- Description: South Africa is rich in biodiversity and is home to about 95 000 known species (South Africa DEA 2014; SANBI 2019). Yet, compared to other southern African countries, the country has a high number of threatened species (Driver et al. 2012). Approximately 12 million South Africans depend on the natural environment to meet their needs. Among other factors, overharvesting of biological resources is one of the main causes of biodiversity loss in the country (South Africa DEA 2014; SANBI 2019). In line with assessment of biodiversity reports, Unesco (2018) notes that biodiversity loss is a global phenomenon. Emphasis in these reports is that over 7 billion people in the world rely on biodiversity to maintain and enhance their well-being. The realisation of biodiversity conservation as a global concern has resulted in various international conventions, policies, legislation and educational programmes that foreground biodiversity (Shava and Schudel 2013). Aligned with international trends, South Africa also has national policies and legislation aimed at protecting biodiversity. Among these is the National Environmental Management Biodiversity Act which introduces a legal framework for governing sustainable development in the country, and includes a clause for all training and education programmes to integrate education for sustainable development (RSA 1998). Thus, like many other countries in the world, South Africa has incorporated biodiversity components in its ongoing curriculum reforms including in the Curriculum Assessment Policy Statement (CAPS).
- Full Text:
- Date Issued: 2021
- Authors: Tshiningayamwe, Sirkka , Lotz-Sisitka, Heila
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/435220 , vital:73139 , ISBN 9781928502241 , https://library.oapen.org/handle/20.500.12657/64082
- Description: South Africa is rich in biodiversity and is home to about 95 000 known species (South Africa DEA 2014; SANBI 2019). Yet, compared to other southern African countries, the country has a high number of threatened species (Driver et al. 2012). Approximately 12 million South Africans depend on the natural environment to meet their needs. Among other factors, overharvesting of biological resources is one of the main causes of biodiversity loss in the country (South Africa DEA 2014; SANBI 2019). In line with assessment of biodiversity reports, Unesco (2018) notes that biodiversity loss is a global phenomenon. Emphasis in these reports is that over 7 billion people in the world rely on biodiversity to maintain and enhance their well-being. The realisation of biodiversity conservation as a global concern has resulted in various international conventions, policies, legislation and educational programmes that foreground biodiversity (Shava and Schudel 2013). Aligned with international trends, South Africa also has national policies and legislation aimed at protecting biodiversity. Among these is the National Environmental Management Biodiversity Act which introduces a legal framework for governing sustainable development in the country, and includes a clause for all training and education programmes to integrate education for sustainable development (RSA 1998). Thus, like many other countries in the world, South Africa has incorporated biodiversity components in its ongoing curriculum reforms including in the Curriculum Assessment Policy Statement (CAPS).
- Full Text:
- Date Issued: 2021
Environmental entrepreneurship as an innovation catalyst for social change: A systematic review as a basis for future research
- Diale, Dineo, Kanakana-Katumba, Mukondeleli G, Maladzhi, Rendani W
- Authors: Diale, Dineo , Kanakana-Katumba, Mukondeleli G , Maladzhi, Rendani W
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/450641 , vital:74970 , xlink:href="https://www.astesj.com/publications/ASTESJ_060145.pdf"
- Description: There are pressures to adopt sustainable behaviour more so in generating profits and benefiting the society to accelerate green efforts through a green framework. The overarching goal of the paper is premised through various works of literature, building the ecosystem the elements highlighted by most researchers in the field of environmental entrepreneurship. The various models reviewed consists of generic incubators and entrepreneurship, and societal and environmental factors. Environmental entrepreneurship is often used interchangeably with concepts such as green entrepreneurship and ecopreneurship which under-researched globally, with non-existent efforts on the applicability and modelling of key environmental entrepreneurship within a specific context utilising the system dynamics approach. In order to assess the environmental entrepreneurship ecosystem, the authors adopted a system dynamic approach to determine key variables that enable the development of the system. A literature review was conducted, and of the 135 articles reviewed, n= 92 peer-reviewed articles met the criteria that the researchers set. Some of the results emanating from a systematic review are environmental policy, green skills, financial and non-financial support, societal and behavioural factors, environmental agility, ethics and governance, and access to markets. The theoretical results are simulated using system dynamics modelling. Due to limited research on the abovementioned topic, a possible impacting variable (Exogenous variables) was broadened to add value to, and have an impact on, the study. Upon reviewing the above-mentioned models, the framework emerged signalling elements to be simulated in the system dynamics model, which were then theoretically contextualised for the South African context. The theoretical virtual system dynamic model forming part of the framework will be tested and validated in the next study. The applicability of the theoretical ecosystem to South African context as well as future recommendations are provided in the study.
- Full Text:
- Date Issued: 2021
- Authors: Diale, Dineo , Kanakana-Katumba, Mukondeleli G , Maladzhi, Rendani W
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/450641 , vital:74970 , xlink:href="https://www.astesj.com/publications/ASTESJ_060145.pdf"
- Description: There are pressures to adopt sustainable behaviour more so in generating profits and benefiting the society to accelerate green efforts through a green framework. The overarching goal of the paper is premised through various works of literature, building the ecosystem the elements highlighted by most researchers in the field of environmental entrepreneurship. The various models reviewed consists of generic incubators and entrepreneurship, and societal and environmental factors. Environmental entrepreneurship is often used interchangeably with concepts such as green entrepreneurship and ecopreneurship which under-researched globally, with non-existent efforts on the applicability and modelling of key environmental entrepreneurship within a specific context utilising the system dynamics approach. In order to assess the environmental entrepreneurship ecosystem, the authors adopted a system dynamic approach to determine key variables that enable the development of the system. A literature review was conducted, and of the 135 articles reviewed, n= 92 peer-reviewed articles met the criteria that the researchers set. Some of the results emanating from a systematic review are environmental policy, green skills, financial and non-financial support, societal and behavioural factors, environmental agility, ethics and governance, and access to markets. The theoretical results are simulated using system dynamics modelling. Due to limited research on the abovementioned topic, a possible impacting variable (Exogenous variables) was broadened to add value to, and have an impact on, the study. Upon reviewing the above-mentioned models, the framework emerged signalling elements to be simulated in the system dynamics model, which were then theoretically contextualised for the South African context. The theoretical virtual system dynamic model forming part of the framework will be tested and validated in the next study. The applicability of the theoretical ecosystem to South African context as well as future recommendations are provided in the study.
- Full Text:
- Date Issued: 2021
Environmental ethics: A sourcebook for educators
- Jickling, Bob, Lotz-Sisitka, Heila, Olvitt, Lausanne L, O’Donoghue, Rob B, Schudel, Ingrid J, McGarry, Dylan K, Niblett, Blair
- Authors: Jickling, Bob , Lotz-Sisitka, Heila , Olvitt, Lausanne L , O’Donoghue, Rob B , Schudel, Ingrid J , McGarry, Dylan K , Niblett, Blair
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/435834 , vital:73205 , ISBN 978-1991201287 , https://www.amazon.com/Environmental-Ethics-Sourcebook-Bob-Jickling/dp/1991201281
- Description: This well-constructed, and highly original, sourcebook inte-grates educational materials for teaching environmental eth-ics with theoretical reflections. The book is set to contribute immensely to its aim of taking ethics out of philosophy de-partments and putting it into the streets, into villages, and on the Earth—to make ethics an everyday activity, not some-thing left to experts and specialists. Context-based activities are presented in almost every chapter. While it acknowledg-es foundational theories in environmental ethics, and the work that they continue to do, it wholeheartedly embraces a growing body of literature that emphasises contextual, pro-cess-oriented, and place-based approaches to ethical reflec-tion, deliberation, and action. It walks on the ground and isn’t afraid to get a little dirty or to seek joy in earthly relationships. And it ultimately breaks with much Western academic tradi-tion by framing “ethics in a storied world”, thus making room to move beyond Euro-American perspectives in environmen-tal issues. This work will be of interest to school teachers and other non-formal and informal educators, teacher educators, college instructors, university professors, and other profes-sionals who wish to bring environmental ethics to the fore-front of their pedagogical practices.
- Full Text:
- Date Issued: 2021
- Authors: Jickling, Bob , Lotz-Sisitka, Heila , Olvitt, Lausanne L , O’Donoghue, Rob B , Schudel, Ingrid J , McGarry, Dylan K , Niblett, Blair
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/435834 , vital:73205 , ISBN 978-1991201287 , https://www.amazon.com/Environmental-Ethics-Sourcebook-Bob-Jickling/dp/1991201281
- Description: This well-constructed, and highly original, sourcebook inte-grates educational materials for teaching environmental eth-ics with theoretical reflections. The book is set to contribute immensely to its aim of taking ethics out of philosophy de-partments and putting it into the streets, into villages, and on the Earth—to make ethics an everyday activity, not some-thing left to experts and specialists. Context-based activities are presented in almost every chapter. While it acknowledg-es foundational theories in environmental ethics, and the work that they continue to do, it wholeheartedly embraces a growing body of literature that emphasises contextual, pro-cess-oriented, and place-based approaches to ethical reflec-tion, deliberation, and action. It walks on the ground and isn’t afraid to get a little dirty or to seek joy in earthly relationships. And it ultimately breaks with much Western academic tradi-tion by framing “ethics in a storied world”, thus making room to move beyond Euro-American perspectives in environmen-tal issues. This work will be of interest to school teachers and other non-formal and informal educators, teacher educators, college instructors, university professors, and other profes-sionals who wish to bring environmental ethics to the fore-front of their pedagogical practices.
- Full Text:
- Date Issued: 2021
Epidemiology, risk factors and molecular analysis of carbapenem-resistant Enterobacteriaceae (CRE) in Mthatha, Eastern Cape, South Africa:
- S.D.Vasaikar, P.Hanise, D.T.Abaver
- Authors: S.D.Vasaikar , P.Hanise , D.T.Abaver
- Date: 2021
- Subjects: Epidemiology Carbapenem-resistant Enterobacteriaceae Mthatha
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/3129 , vital:43143 , xlink:href="https://doi.org/10.3390/f10060467"
- Description: Abstract text. Background: The emergence of carbapenem resistance in Enterobacteriaceae is an important threat to global health. Reported outcomes of infections with carbapenem-resistant Enterobacteriaceae (CRE) are poor. Commonly used antibiotics are generally inactive against CRE. Therefore, timely detection of CRE is of paramount importance. This study aimed to investigate the resistance genes responsible for CRE in Mthatha and to identify risk factors. Methods and materials: Study design – Prospective cohort study. Study period – 23 April to 27 September 2019. Setting – Eastern Cape province, SA. Study population – All adult and paediatric CRE patients. CRE case definition according to CDC 2018. ID and AST-bioMérieux Vitek 2 system. Detection of the blaOXA-48, blaKPC, blaNDM, and blaVIM by the RESIST-4 OKNV assay (Coris). Patients were interviewed to determine risk factors associated with CRE. Results: Forty-four non-duplicate CRE patients were identified during the study period from microbiology lab at NMAH. Enterobacteriaceae species: K. pneumoniae 22 (61.4%), E. cloacae 10 (22.7%), E. coli 2 (4.5%) and K. oxytoca, P. rettgeri and M. morganii 1 each (4.3%). Adult patient 29 (65.9%0 and paediatric 15 (34.1%). Race: all black patients except one white. CRE genes-blaOXA-48 22 (50%), blaNDM 8 (18.2%), two isolates (4.5%) with both blaOXA and blaNDM. We did not find any blaKPC and blaVIM in our setting and 12 (27.2%) isolates were negative for all OKNV. Outcomes: Demised 18 (40.9%), still admitted in the ward 1 (2.3%), discharged home on basis of clinical grounds 22 (50%) and 3 (6.8%) were transferred back to the district hospitals. HAI in 27 (61.4%) with VAP 8, HABSI 8, CAUTI 5, SSI 3 and CLABSI in 3. Risk factors for CRE acquisition were antibiotic exposure 25 (58.7%), ICU stay 7 (15.9%), received medical care in last 6 months 35 (79.6%) and none travelled outside RSA. HIV positive – 19 (43.2%). Conclusion: In out setting our CRE mortality rate is 40.9%, common CRE genotypes are blaOXA-48 and blaNDM. K. pneumoniae is the most common CRE-producing Enterobacteriaceae and antibiotic exposure is an important risk factor in Mthatha and surrounding areas.
- Full Text:
- Date Issued: 2021
- Authors: S.D.Vasaikar , P.Hanise , D.T.Abaver
- Date: 2021
- Subjects: Epidemiology Carbapenem-resistant Enterobacteriaceae Mthatha
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/3129 , vital:43143 , xlink:href="https://doi.org/10.3390/f10060467"
- Description: Abstract text. Background: The emergence of carbapenem resistance in Enterobacteriaceae is an important threat to global health. Reported outcomes of infections with carbapenem-resistant Enterobacteriaceae (CRE) are poor. Commonly used antibiotics are generally inactive against CRE. Therefore, timely detection of CRE is of paramount importance. This study aimed to investigate the resistance genes responsible for CRE in Mthatha and to identify risk factors. Methods and materials: Study design – Prospective cohort study. Study period – 23 April to 27 September 2019. Setting – Eastern Cape province, SA. Study population – All adult and paediatric CRE patients. CRE case definition according to CDC 2018. ID and AST-bioMérieux Vitek 2 system. Detection of the blaOXA-48, blaKPC, blaNDM, and blaVIM by the RESIST-4 OKNV assay (Coris). Patients were interviewed to determine risk factors associated with CRE. Results: Forty-four non-duplicate CRE patients were identified during the study period from microbiology lab at NMAH. Enterobacteriaceae species: K. pneumoniae 22 (61.4%), E. cloacae 10 (22.7%), E. coli 2 (4.5%) and K. oxytoca, P. rettgeri and M. morganii 1 each (4.3%). Adult patient 29 (65.9%0 and paediatric 15 (34.1%). Race: all black patients except one white. CRE genes-blaOXA-48 22 (50%), blaNDM 8 (18.2%), two isolates (4.5%) with both blaOXA and blaNDM. We did not find any blaKPC and blaVIM in our setting and 12 (27.2%) isolates were negative for all OKNV. Outcomes: Demised 18 (40.9%), still admitted in the ward 1 (2.3%), discharged home on basis of clinical grounds 22 (50%) and 3 (6.8%) were transferred back to the district hospitals. HAI in 27 (61.4%) with VAP 8, HABSI 8, CAUTI 5, SSI 3 and CLABSI in 3. Risk factors for CRE acquisition were antibiotic exposure 25 (58.7%), ICU stay 7 (15.9%), received medical care in last 6 months 35 (79.6%) and none travelled outside RSA. HIV positive – 19 (43.2%). Conclusion: In out setting our CRE mortality rate is 40.9%, common CRE genotypes are blaOXA-48 and blaNDM. K. pneumoniae is the most common CRE-producing Enterobacteriaceae and antibiotic exposure is an important risk factor in Mthatha and surrounding areas.
- Full Text:
- Date Issued: 2021
Ethnobotanical survey, phytoconstituents and antibacterial investigation of Rapanea melanophloeos (L.) Mez. bark, fruit and leaf extracts
- Lukhele, Thabile, Olivier, Denise K, Tata, Charlotte, Ikhile, Monisola I, Krause, Rui W M, van Vuuren, Sandy, Ndineh, Derek T
- Authors: Lukhele, Thabile , Olivier, Denise K , Tata, Charlotte , Ikhile, Monisola I , Krause, Rui W M , van Vuuren, Sandy , Ndineh, Derek T
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/191791 , vital:45164 , xlink:href="https://doi.org/10.1515/psr-2020-0143"
- Description: Rapanea melanophloeos is traditionally used in South Africa in the treatment of ailments of the skin, pulmonary and gastro intestinal tract. This study was aimed at giving an overview of these traditional uses and comparing the phytochemicals and antibacterial activities of various crude extracts of the leaves, fruits and bark in order to validate these uses. The three plant parts were extracted using petroleum ether (PE), ethyl acetate (EtOAc), methanol (MeOH) and water. Various phytochemicals were compared using TLC, while alcohol precipitable solids (APS), non-polar terpenes and amino acids were analysed by GC-MS. Antibacterial activity was determined against three Gram-positive and three Gram-negative strains by microdilution assays. Caryophyllene oxides, α-cadinol and (−)-spathulenol were identified in the PE extracts. All nine essential amino acids were present in fruit extracts in significantly higher levels than in the leaves and bark; 255.1, 23.4 and 21.3 mg/g respectively. Most of the extracts showed good antibacterial activity, especially against the Gram-positive pathogens (MIC of ≤1 mg/mL), the EtOAc extracts exhibited the best activity with the fruit having an MIC values of 0.1 ± 0.2 mg/mL against Staphylococcus epidermidis and Enterococcus faecalis, 0.05 mg/mL against Bacillus cereus. Results from this study validate the ethnomedicinal uses of R. melanophloeos extracts for ailments of bacterial etiology. The plant had a rich supply of secondary metabolites, APS and amino acids and TLC and antibacterial activities of the extracts showed slight variations in chemical composition due to geographic distribution.
- Full Text:
- Date Issued: 2021
- Authors: Lukhele, Thabile , Olivier, Denise K , Tata, Charlotte , Ikhile, Monisola I , Krause, Rui W M , van Vuuren, Sandy , Ndineh, Derek T
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/191791 , vital:45164 , xlink:href="https://doi.org/10.1515/psr-2020-0143"
- Description: Rapanea melanophloeos is traditionally used in South Africa in the treatment of ailments of the skin, pulmonary and gastro intestinal tract. This study was aimed at giving an overview of these traditional uses and comparing the phytochemicals and antibacterial activities of various crude extracts of the leaves, fruits and bark in order to validate these uses. The three plant parts were extracted using petroleum ether (PE), ethyl acetate (EtOAc), methanol (MeOH) and water. Various phytochemicals were compared using TLC, while alcohol precipitable solids (APS), non-polar terpenes and amino acids were analysed by GC-MS. Antibacterial activity was determined against three Gram-positive and three Gram-negative strains by microdilution assays. Caryophyllene oxides, α-cadinol and (−)-spathulenol were identified in the PE extracts. All nine essential amino acids were present in fruit extracts in significantly higher levels than in the leaves and bark; 255.1, 23.4 and 21.3 mg/g respectively. Most of the extracts showed good antibacterial activity, especially against the Gram-positive pathogens (MIC of ≤1 mg/mL), the EtOAc extracts exhibited the best activity with the fruit having an MIC values of 0.1 ± 0.2 mg/mL against Staphylococcus epidermidis and Enterococcus faecalis, 0.05 mg/mL against Bacillus cereus. Results from this study validate the ethnomedicinal uses of R. melanophloeos extracts for ailments of bacterial etiology. The plant had a rich supply of secondary metabolites, APS and amino acids and TLC and antibacterial activities of the extracts showed slight variations in chemical composition due to geographic distribution.
- Full Text:
- Date Issued: 2021
Evaluating and reflecting on coproduction of protected area management plans
- Roux, Dirk J, Nel, Jeanne L, Freitag, Stefanie, Novellie, Peter, Rosenberg, Eureta
- Authors: Roux, Dirk J , Nel, Jeanne L , Freitag, Stefanie , Novellie, Peter , Rosenberg, Eureta
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/370550 , vital:66353 , xlink:href="https://doi.org/10.1111/csp2.542"
- Description: Protected areas are complex social-ecological systems, hence their management should be guided by engagement and co-learning with diverse stakeholders. The challenge of effective stakeholder participation has generated a body of literature on the design and facilitation of coproduction processes. In this study, we used this literature to develop a principle-based framework for assessing coproduction. We then applied this framework to evaluate how well “adaptive planning” (a sub-process of adaptive management used for visioning and objective setting with stakeholders), as applied to the Garden Route National Park in South Africa, aligned with the ideals of coproduction. Our analysis revealed shortcomings in the adaptive planning process, which could be improved through broadening the agenda beyond the mandate and control of national parks, empowering collective agency among a wider stakeholder network, and embedding co-learning with stakeholders as an ongoing journey. A significant finding was that adaptive management does not align well with the ideals of coproduction, which may be better supported by an adaptive comanagement approach. The latter is particularly necessary in complex national parks that are diverse in terms of both ecosystems and stakeholders, and where governance may be contested.
- Full Text:
- Date Issued: 2021
- Authors: Roux, Dirk J , Nel, Jeanne L , Freitag, Stefanie , Novellie, Peter , Rosenberg, Eureta
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/370550 , vital:66353 , xlink:href="https://doi.org/10.1111/csp2.542"
- Description: Protected areas are complex social-ecological systems, hence their management should be guided by engagement and co-learning with diverse stakeholders. The challenge of effective stakeholder participation has generated a body of literature on the design and facilitation of coproduction processes. In this study, we used this literature to develop a principle-based framework for assessing coproduction. We then applied this framework to evaluate how well “adaptive planning” (a sub-process of adaptive management used for visioning and objective setting with stakeholders), as applied to the Garden Route National Park in South Africa, aligned with the ideals of coproduction. Our analysis revealed shortcomings in the adaptive planning process, which could be improved through broadening the agenda beyond the mandate and control of national parks, empowering collective agency among a wider stakeholder network, and embedding co-learning with stakeholders as an ongoing journey. A significant finding was that adaptive management does not align well with the ideals of coproduction, which may be better supported by an adaptive comanagement approach. The latter is particularly necessary in complex national parks that are diverse in terms of both ecosystems and stakeholders, and where governance may be contested.
- Full Text:
- Date Issued: 2021
Evaluating Community Engagement Strategies to Manage Stigma in Two African Genomics Studies Involving People Living with Schizophrenia or Rheumatic Heart Disease
- Campbell, Megan M, Matshabane, Olivia P, Mqulwana, Sibonile, Mndini, Michael, Nagdee, Mohammed, Stein, Dan J, de Vries, Jantina
- Authors: Campbell, Megan M , Matshabane, Olivia P , Mqulwana, Sibonile , Mndini, Michael , Nagdee, Mohammed , Stein, Dan J , de Vries, Jantina
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/302475 , vital:58199 , xlink:href="https://doi.org/10.1155/2021/9926495"
- Description: In global health research and genomics research specifically, community engagement has gained prominence in enhancing ethical conduct, particularly in managing the risk of stigmatization, but there is minimal scientific evidence on how to do this effectively. This article reports on community engagement evaluation strategies in two African genomics studies: the Stigma in African Genomics Research study and the Genomics of Schizophrenia in South African Xhosa People (SAX) study. Within the Stigma in African Genomics Research study, a self-report rating scale and open-ended questions were used to track participant responses to an experiential theatre workshop. The workshop focused on participant experiences of living with schizophrenia or rheumatic heart disease (RHD). While the schizophrenia group reported more alienation and less stigma resistance than the RHD group, both groups demonstrated increased stigma resistance over time, after participating in the workshops. Hearing from others living with and managing the same illness normalised participants’ own experiences and encouraged them. Within the SAX study, a short rating scale and qualitative feedback methods were used to evaluate a Mental Health Literacy Day targeting mental health stigma. Information talks about (i) the symptoms of schizophrenia and treatment options and (ii) the illness experiences of a patient in recovery were rated as the most helpful on the day. Audience members reported that these talks challenged negative perceptions about severe mental illness. Three important learnings emerged from these evaluations: firstly, integration of evaluation strategies at the research study planning phase is likely to promote more effective community engagement. Secondly, a combination of quantitative and qualitative methods that draw on simple descriptive statistics and thematic analysis can provide nuanced perspectives about the value of community engagement. Thirdly, such evidence is necessary in establishing and promoting the science of community engagement in genomics research and health research more broadly.
- Full Text:
- Date Issued: 2021
- Authors: Campbell, Megan M , Matshabane, Olivia P , Mqulwana, Sibonile , Mndini, Michael , Nagdee, Mohammed , Stein, Dan J , de Vries, Jantina
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/302475 , vital:58199 , xlink:href="https://doi.org/10.1155/2021/9926495"
- Description: In global health research and genomics research specifically, community engagement has gained prominence in enhancing ethical conduct, particularly in managing the risk of stigmatization, but there is minimal scientific evidence on how to do this effectively. This article reports on community engagement evaluation strategies in two African genomics studies: the Stigma in African Genomics Research study and the Genomics of Schizophrenia in South African Xhosa People (SAX) study. Within the Stigma in African Genomics Research study, a self-report rating scale and open-ended questions were used to track participant responses to an experiential theatre workshop. The workshop focused on participant experiences of living with schizophrenia or rheumatic heart disease (RHD). While the schizophrenia group reported more alienation and less stigma resistance than the RHD group, both groups demonstrated increased stigma resistance over time, after participating in the workshops. Hearing from others living with and managing the same illness normalised participants’ own experiences and encouraged them. Within the SAX study, a short rating scale and qualitative feedback methods were used to evaluate a Mental Health Literacy Day targeting mental health stigma. Information talks about (i) the symptoms of schizophrenia and treatment options and (ii) the illness experiences of a patient in recovery were rated as the most helpful on the day. Audience members reported that these talks challenged negative perceptions about severe mental illness. Three important learnings emerged from these evaluations: firstly, integration of evaluation strategies at the research study planning phase is likely to promote more effective community engagement. Secondly, a combination of quantitative and qualitative methods that draw on simple descriptive statistics and thematic analysis can provide nuanced perspectives about the value of community engagement. Thirdly, such evidence is necessary in establishing and promoting the science of community engagement in genomics research and health research more broadly.
- Full Text:
- Date Issued: 2021
Evaluating the cyber security skills gap relating to penetration testing
- Authors: Beukes, Dirk Johannes
- Date: 2021
- Subjects: Computer networks -- Security measures , Computer networks -- Monitoring , Computer networks -- Management , Data protection , Information technology -- Security measures , Professionals -- Supply and demand , Electronic data personnel -- Supply and demand
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/171120 , vital:42021
- Description: Information Technology (IT) is growing rapidly and has become an integral part of daily life. It provides a boundless list of services and opportunities, generating boundless sources of information, which could be abused or exploited. Due to this growth, there are thousands of new users added to the grid using computer systems in a static and mobile environment; this fact alone creates endless volumes of data to be exploited and hardware devices to be abused by the wrong people. The growth in the IT environment adds challenges that may affect users in their personal, professional, and business lives. There are constant threats on corporate and private computer networks and computer systems. In the corporate environment companies try to eliminate the threat by testing networks making use of penetration tests and by implementing cyber awareness programs to make employees more aware of the cyber threat. Penetration tests and vulnerability assessments are undervalued; are seen as a formality and are not used to increase system security. If used regularly the computer system will be more secure and attacks minimized. With the growth in technology, industries all over the globe become fully dependent on information systems in doing their day-to-day business. As technology evolves and new technology becomes available, the bigger the risk becomes to protect against the dangers which come with this new technology. For industry to protect itself against this growth in technology, personnel with a certain skill set is needed. This is where cyber security plays a very important role in the protection of information systems to ensure the confidentiality, integrity and availability of the information system itself and the data on the system. Due to this drive to secure information systems, the need for cyber security by professionals is on the rise as well. It is estimated that there is a shortage of one million cyber security professionals globally. What is the reason for this skills shortage? Will it be possible to close this skills shortage gap? This study is about identifying the skills gap and identifying possible ways to close this skills gap. In this study, research was conducted on the cyber security international standards, cyber security training at universities and international certification focusing specifically on penetration testing, the evaluation of the need of industry while recruiting new penetration testers, finishing with suggestions on how to fill possible gaps in the skills market with a conclusion.
- Full Text:
- Date Issued: 2021
- Authors: Beukes, Dirk Johannes
- Date: 2021
- Subjects: Computer networks -- Security measures , Computer networks -- Monitoring , Computer networks -- Management , Data protection , Information technology -- Security measures , Professionals -- Supply and demand , Electronic data personnel -- Supply and demand
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/171120 , vital:42021
- Description: Information Technology (IT) is growing rapidly and has become an integral part of daily life. It provides a boundless list of services and opportunities, generating boundless sources of information, which could be abused or exploited. Due to this growth, there are thousands of new users added to the grid using computer systems in a static and mobile environment; this fact alone creates endless volumes of data to be exploited and hardware devices to be abused by the wrong people. The growth in the IT environment adds challenges that may affect users in their personal, professional, and business lives. There are constant threats on corporate and private computer networks and computer systems. In the corporate environment companies try to eliminate the threat by testing networks making use of penetration tests and by implementing cyber awareness programs to make employees more aware of the cyber threat. Penetration tests and vulnerability assessments are undervalued; are seen as a formality and are not used to increase system security. If used regularly the computer system will be more secure and attacks minimized. With the growth in technology, industries all over the globe become fully dependent on information systems in doing their day-to-day business. As technology evolves and new technology becomes available, the bigger the risk becomes to protect against the dangers which come with this new technology. For industry to protect itself against this growth in technology, personnel with a certain skill set is needed. This is where cyber security plays a very important role in the protection of information systems to ensure the confidentiality, integrity and availability of the information system itself and the data on the system. Due to this drive to secure information systems, the need for cyber security by professionals is on the rise as well. It is estimated that there is a shortage of one million cyber security professionals globally. What is the reason for this skills shortage? Will it be possible to close this skills shortage gap? This study is about identifying the skills gap and identifying possible ways to close this skills gap. In this study, research was conducted on the cyber security international standards, cyber security training at universities and international certification focusing specifically on penetration testing, the evaluation of the need of industry while recruiting new penetration testers, finishing with suggestions on how to fill possible gaps in the skills market with a conclusion.
- Full Text:
- Date Issued: 2021
Evaluation of metallophthalocyanine functionalized photocatalytic asymmetric polymer membranes for pollution control and antimicrobial activity
- Mafukidze, Donovan Musizvinoda Chidyamurimi
- Authors: Mafukidze, Donovan Musizvinoda Chidyamurimi
- Date: 2021
- Subjects: Photosensitizing compounds , Water -- Purification -- Photocatalysis , Phthalocyanines , Polymeric membranes , Porphyrins
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/171357 , vital:42052 , 10.21504/10962/171357
- Description: The conceptualisation of photosensitizing water treatment polymer membranes using phthalocyanine based photosensitizers is reported in this thesis. The key to successful preparation of stable photoactive polymer membranes was established as the covalent anchorage of the photosensitizer to a polymer, which was proven by singlet oxygen generation by the membranes without photosensitizer deterioration. Despite this limitation, the covalent linkage-incapable unsubstituted zinc (II) phthalocyanine (complex 2) was applied as a nanoconjugate of graphene quantum dots (2π(GQDs)). 2π(GQDs) was formed through π-π stacking, and was then covalently anchored, as a proof of concept. This concept was also applied to 2-(4-carboxyphenoxy) phthalocyaninato zinc (II) (complex 3) which is capable of covalent linkage but proved to deteriorate the efficiency of singlet oxygen formation with comparison to the covalent conjugates. Singlet oxygen generation by functionalized polymer membranes rendered them photocatalytic in the degradation of organic pollutants and microorganisms in water. Organic pollutant degradation capability was exemplified by 2π(GQDs) and a porphyrin-phthalocyanine heterodyad (complex 10) functionalized membranes (2π(GQDs)-memb and 10-memb respectively), where a MPc loading of approximately 0.139 μmol MPc/g of membrane was able to achieve a 4-chlorophenol degradation rate of 3.77 × 10−6 mol L−1 min−1 in a second order reaction with an initial 4-chlorophenol concentration of 3.24 × 10−4 mol L−1 for 2π(GQDs)-memb as an example. Antibacterial studies against S.aureus using a quaternized MPc and conjugates of silver triangular nanoprisms with zinc (II) and indium (III) MPcs showed note-worthy improvements in photodynamic antimicrobial chemotherapy (PACT) activity in comparison to the unquaternized MPc precursor, and the free zinc and indium MPcs respectively. Functionalization of polymer membranes with these higher activity photosensitizers translated to the formation of potentially superior biological fouling resistant membranes. The use of porphyrin-phthalocyanine polynuclei arrays (complex 10) in polymer membrane functionalization resulted in the use of a wider wavelength range (white light). The findings from this work as a whole, thus presents the potential applicability of phthalocyanine functionalized polymer membranes in water treatment technology.
- Full Text:
- Date Issued: 2021
- Authors: Mafukidze, Donovan Musizvinoda Chidyamurimi
- Date: 2021
- Subjects: Photosensitizing compounds , Water -- Purification -- Photocatalysis , Phthalocyanines , Polymeric membranes , Porphyrins
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/171357 , vital:42052 , 10.21504/10962/171357
- Description: The conceptualisation of photosensitizing water treatment polymer membranes using phthalocyanine based photosensitizers is reported in this thesis. The key to successful preparation of stable photoactive polymer membranes was established as the covalent anchorage of the photosensitizer to a polymer, which was proven by singlet oxygen generation by the membranes without photosensitizer deterioration. Despite this limitation, the covalent linkage-incapable unsubstituted zinc (II) phthalocyanine (complex 2) was applied as a nanoconjugate of graphene quantum dots (2π(GQDs)). 2π(GQDs) was formed through π-π stacking, and was then covalently anchored, as a proof of concept. This concept was also applied to 2-(4-carboxyphenoxy) phthalocyaninato zinc (II) (complex 3) which is capable of covalent linkage but proved to deteriorate the efficiency of singlet oxygen formation with comparison to the covalent conjugates. Singlet oxygen generation by functionalized polymer membranes rendered them photocatalytic in the degradation of organic pollutants and microorganisms in water. Organic pollutant degradation capability was exemplified by 2π(GQDs) and a porphyrin-phthalocyanine heterodyad (complex 10) functionalized membranes (2π(GQDs)-memb and 10-memb respectively), where a MPc loading of approximately 0.139 μmol MPc/g of membrane was able to achieve a 4-chlorophenol degradation rate of 3.77 × 10−6 mol L−1 min−1 in a second order reaction with an initial 4-chlorophenol concentration of 3.24 × 10−4 mol L−1 for 2π(GQDs)-memb as an example. Antibacterial studies against S.aureus using a quaternized MPc and conjugates of silver triangular nanoprisms with zinc (II) and indium (III) MPcs showed note-worthy improvements in photodynamic antimicrobial chemotherapy (PACT) activity in comparison to the unquaternized MPc precursor, and the free zinc and indium MPcs respectively. Functionalization of polymer membranes with these higher activity photosensitizers translated to the formation of potentially superior biological fouling resistant membranes. The use of porphyrin-phthalocyanine polynuclei arrays (complex 10) in polymer membrane functionalization resulted in the use of a wider wavelength range (white light). The findings from this work as a whole, thus presents the potential applicability of phthalocyanine functionalized polymer membranes in water treatment technology.
- Full Text:
- Date Issued: 2021
Exploring domestic workers’ subjectivities through stories of their personal childcare arrangements
- Authors: Michaeu, Nisha
- Date: 2021
- Subjects: Women household employees, Black -- Social conditions -- South Africa , Women household employees, Black -- Social conditions -- South Africa -- Case studies , Women household employees, Black -- Psychology -- South Africa , Day care aides -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/172029 , vital:42150
- Description: Domestic service has long been a major sector of the South African labour market, for black women particularly, who must support their family and children. Existing research has stressed the way in which race, class and gender has shaped the oppressive character of domestic service in South Africa. In this narrative study a new slant is provided on this existing theoretical discussion of domestic labour, one that is focused on exploring the agentic human being beyond ‘the servant question’. This study uses narrative interviews with domestic workers in Makhanda/Grahamstown in the Eastern Cape province of South Africa to show how we can expand on potentially limited or constricted passive ‘domestic worker identities’ and ideas/beliefs about women who do domestic work. A performative and positioning narrative analysis is used to explore the subject positions of domestic workers in their stories about their childcare arrangements. This analysis examines multiple shifting identities and positions that are used by domestic workers in relation to their maternal subjectivity and their audience (here, a white trainee-psychologist esearcher), while highlighting the significance of narrative methodology in making these positions visible. The areas of focus were their history, experience of domestic work, life outside of domestic work, family network/dynamics and personal childcare arrangements. Under these areas of focus the following was analysed: the ways in which the storyteller positioned herself in her narrative, how she compared/contrasted or located herself in relation to the other, claims of identity that were made, what she incorporated or purposefully left out, words and phrases that were chosen, which sections of talk were embellished or elaborated on and appeals that were made to the interviewer (Riessman, 2002). Through exploring the micro-practices of domestic workers’ lives the study found that there were various subject positions constructed and used by this group of women. Findings showed that domestic workers positioned themselves actively as breadwinners, good mothers who give their children opportunities that they were not given, nurturers and crafty mothers who secure good care for their children. In contrast to these active subject positions, positions of sacrifice were performed when domestic workers spoke about leaving their young children in the care of another while they worked. The study also found that participants managed complex positions of disappointment and unmet expectations for a better life in the new South Africa by using narratives of resistance and agency. In certain instances, identity appeals were made to the interviewer that they, and other women who do domestic work, are entrepreneurial and creative with their income and possess skills outside of their day-to-day household cleaning jobs. This was interpreted as an attempt to extend the domestic worker identity positioning beyond the traditionally accepted notions of unskilled/uneducated women who do domestic work. In the study this allowed for more subject positions to be taken up in terms of identities and selves, beyond just being a “domestic worker”.
- Full Text:
- Date Issued: 2021
- Authors: Michaeu, Nisha
- Date: 2021
- Subjects: Women household employees, Black -- Social conditions -- South Africa , Women household employees, Black -- Social conditions -- South Africa -- Case studies , Women household employees, Black -- Psychology -- South Africa , Day care aides -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/172029 , vital:42150
- Description: Domestic service has long been a major sector of the South African labour market, for black women particularly, who must support their family and children. Existing research has stressed the way in which race, class and gender has shaped the oppressive character of domestic service in South Africa. In this narrative study a new slant is provided on this existing theoretical discussion of domestic labour, one that is focused on exploring the agentic human being beyond ‘the servant question’. This study uses narrative interviews with domestic workers in Makhanda/Grahamstown in the Eastern Cape province of South Africa to show how we can expand on potentially limited or constricted passive ‘domestic worker identities’ and ideas/beliefs about women who do domestic work. A performative and positioning narrative analysis is used to explore the subject positions of domestic workers in their stories about their childcare arrangements. This analysis examines multiple shifting identities and positions that are used by domestic workers in relation to their maternal subjectivity and their audience (here, a white trainee-psychologist esearcher), while highlighting the significance of narrative methodology in making these positions visible. The areas of focus were their history, experience of domestic work, life outside of domestic work, family network/dynamics and personal childcare arrangements. Under these areas of focus the following was analysed: the ways in which the storyteller positioned herself in her narrative, how she compared/contrasted or located herself in relation to the other, claims of identity that were made, what she incorporated or purposefully left out, words and phrases that were chosen, which sections of talk were embellished or elaborated on and appeals that were made to the interviewer (Riessman, 2002). Through exploring the micro-practices of domestic workers’ lives the study found that there were various subject positions constructed and used by this group of women. Findings showed that domestic workers positioned themselves actively as breadwinners, good mothers who give their children opportunities that they were not given, nurturers and crafty mothers who secure good care for their children. In contrast to these active subject positions, positions of sacrifice were performed when domestic workers spoke about leaving their young children in the care of another while they worked. The study also found that participants managed complex positions of disappointment and unmet expectations for a better life in the new South Africa by using narratives of resistance and agency. In certain instances, identity appeals were made to the interviewer that they, and other women who do domestic work, are entrepreneurial and creative with their income and possess skills outside of their day-to-day household cleaning jobs. This was interpreted as an attempt to extend the domestic worker identity positioning beyond the traditionally accepted notions of unskilled/uneducated women who do domestic work. In the study this allowed for more subject positions to be taken up in terms of identities and selves, beyond just being a “domestic worker”.
- Full Text:
- Date Issued: 2021
Exploring the role of supervisors in developing employee commitment in a Namibian Public Institution from the subordinates’ perspective
- Authors: Daniel, Anna
- Date: 2021
- Subjects: Supervisors -- Namibia -- Case studies , Leadership -- Namibia -- Case studies , Employee motivation -- Namibia -- Case studies , Employee loyalty -- Namibia -- Case studies , Supervision -- Namibia -- Case studies , Management -- Employee participation -- Namibia -- Case studies
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/170770 , vital:41958
- Description: Over the years, scholars have noted the importance of organisations managing the performance of their employees by effectively maintaining their commitment. Hence, l ite rature highlighted that employee s have the potential to be recognised as a source of competitive advantage for an organisation and not a resource of an organisation. The main aim of the study was to explore the role of supervisors in developing employee commitment in a Namibian Public Ins titution from the subordinates’ perspective. The focus of this research was to understand how subordinates were included in decision making and were supported by their supervisors , and on how subordinates received feed b ack on role fulfilment and performance from their supervisors. Furthermore, the study described how subordinates viewed the leadership behaviour of their supervisors and how this i nfluenced employee commitment. The data was collected using qualitative me t hods through semi - structured face - to - face interview s with the subordinates of the selected institution. During this study, a sample of 15 subordinates taken from a population of 266 within the institution’s structure was inte rviewed . The interview quest ion s were based on how supervisors included subordinates in decision making, developed subordinates ’ support and delivered feedback on role and performance. The study used secondary data to determine the level of performance against set targets of the inst itu tion, using the annual performance report of the institution. In addition , the study used the staff access control syste m to determine the work time s of employees Lastly, the study analysed the data regarding staff resignation for the last five years to a ssess the level of staff turnover rate of the institution. The study f ound that the subordinates felt the re should be greater subordinate inclusion in decision making, increased levels of re gular feedback and higher levels of support shown by supervis ors t o subordinates when e xecuting their jobs. The study further highlighted the importance of supervisors to develop the ability of shifting from one leadership style to another depending on the situation at hand. The study reviewed six leadership style s that could influence commitment . Therefore, the study recommend s th at the institution direct its attention towards developing the situational leadership skills of their supervisors and developing their skills to enable them to better harmonise teamwork, increas e regular communication and give regular feedback to their subordinates . The results from this research will be beneficial to public institutions within the region and will, in add ition, enhance the academic body of literature in this field . The s tudy will draw the attention of supervisors to the importance of their behaviour, conduct, and their subsequent impact on employee commitment.
- Full Text:
- Date Issued: 2021
- Authors: Daniel, Anna
- Date: 2021
- Subjects: Supervisors -- Namibia -- Case studies , Leadership -- Namibia -- Case studies , Employee motivation -- Namibia -- Case studies , Employee loyalty -- Namibia -- Case studies , Supervision -- Namibia -- Case studies , Management -- Employee participation -- Namibia -- Case studies
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/170770 , vital:41958
- Description: Over the years, scholars have noted the importance of organisations managing the performance of their employees by effectively maintaining their commitment. Hence, l ite rature highlighted that employee s have the potential to be recognised as a source of competitive advantage for an organisation and not a resource of an organisation. The main aim of the study was to explore the role of supervisors in developing employee commitment in a Namibian Public Ins titution from the subordinates’ perspective. The focus of this research was to understand how subordinates were included in decision making and were supported by their supervisors , and on how subordinates received feed b ack on role fulfilment and performance from their supervisors. Furthermore, the study described how subordinates viewed the leadership behaviour of their supervisors and how this i nfluenced employee commitment. The data was collected using qualitative me t hods through semi - structured face - to - face interview s with the subordinates of the selected institution. During this study, a sample of 15 subordinates taken from a population of 266 within the institution’s structure was inte rviewed . The interview quest ion s were based on how supervisors included subordinates in decision making, developed subordinates ’ support and delivered feedback on role and performance. The study used secondary data to determine the level of performance against set targets of the inst itu tion, using the annual performance report of the institution. In addition , the study used the staff access control syste m to determine the work time s of employees Lastly, the study analysed the data regarding staff resignation for the last five years to a ssess the level of staff turnover rate of the institution. The study f ound that the subordinates felt the re should be greater subordinate inclusion in decision making, increased levels of re gular feedback and higher levels of support shown by supervis ors t o subordinates when e xecuting their jobs. The study further highlighted the importance of supervisors to develop the ability of shifting from one leadership style to another depending on the situation at hand. The study reviewed six leadership style s that could influence commitment . Therefore, the study recommend s th at the institution direct its attention towards developing the situational leadership skills of their supervisors and developing their skills to enable them to better harmonise teamwork, increas e regular communication and give regular feedback to their subordinates . The results from this research will be beneficial to public institutions within the region and will, in add ition, enhance the academic body of literature in this field . The s tudy will draw the attention of supervisors to the importance of their behaviour, conduct, and their subsequent impact on employee commitment.
- Full Text:
- Date Issued: 2021
External Factors affecting Blackboard Learning Management System adoption by Students: Evidence from a Historically Disadvantaged Higher Education Institution in South Africa
- O. Matarirano, M. Panicker, N.R. Jere https://orcid.org/0000-0001-8966-2753, A. Maliwa
- Authors: O. Matarirano , M. Panicker , N.R. Jere https://orcid.org/0000-0001-8966-2753 , A. Maliwa
- Date: 2021
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/3304 , vital:43306 , https://doi.org/10.20853/35-2-4025
- Description: Learning Management Systems (LMS) have the ability to transform learning experiences of students in Higher Education Institutions (HEI). In addition to the developmental benefits, LMS assist teaching and learning during student unrests, a common feature in historically disadvantaged institutions in South Africa. Regardless of the benefits of LMS platforms such as Blackboard, the utilisation by university students at the institution under study has been very low. Applying cross sectional electronic survey, this study identifies the key factors influencing technology adoption, as identified in the General Extended Technology Acceptance Model for E-Learning (GETAMEL), behind perceived ease of use and perceived usefulness in the adoption of technology. A sample of 125 students at a historically disadvantaged institution in South Africa was considered for the study. Data was collected to understand their perceptions on use of Blackboard Learning Management System (BB) for learning. Data was analysed with SmartPLS statistical analysis software. Results show that perceived ease of use of BB is influenced by computer self-efficacy, computer amusement and computer anxiety whilst perceived usefulness of BB is influenced by subjective norm and computer enjoyment. The findings also show computer experience to significantly affect computer self-efficacy and computer self-efficacy to affect computer enjoyment. The article presents the external factors that affect the usage of LMS at one of the historically disadvantaged HEI in South Africa. HEI leadership has to prioritise the identified external factors to increase chances of acceptance and utilisation of Blackboard by learners.
- Full Text:
- Date Issued: 2021
- Authors: O. Matarirano , M. Panicker , N.R. Jere https://orcid.org/0000-0001-8966-2753 , A. Maliwa
- Date: 2021
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/3304 , vital:43306 , https://doi.org/10.20853/35-2-4025
- Description: Learning Management Systems (LMS) have the ability to transform learning experiences of students in Higher Education Institutions (HEI). In addition to the developmental benefits, LMS assist teaching and learning during student unrests, a common feature in historically disadvantaged institutions in South Africa. Regardless of the benefits of LMS platforms such as Blackboard, the utilisation by university students at the institution under study has been very low. Applying cross sectional electronic survey, this study identifies the key factors influencing technology adoption, as identified in the General Extended Technology Acceptance Model for E-Learning (GETAMEL), behind perceived ease of use and perceived usefulness in the adoption of technology. A sample of 125 students at a historically disadvantaged institution in South Africa was considered for the study. Data was collected to understand their perceptions on use of Blackboard Learning Management System (BB) for learning. Data was analysed with SmartPLS statistical analysis software. Results show that perceived ease of use of BB is influenced by computer self-efficacy, computer amusement and computer anxiety whilst perceived usefulness of BB is influenced by subjective norm and computer enjoyment. The findings also show computer experience to significantly affect computer self-efficacy and computer self-efficacy to affect computer enjoyment. The article presents the external factors that affect the usage of LMS at one of the historically disadvantaged HEI in South Africa. HEI leadership has to prioritise the identified external factors to increase chances of acceptance and utilisation of Blackboard by learners.
- Full Text:
- Date Issued: 2021
Feasibility Study: Computing Confidence Interval (CI) for IBR Data Using Bootstrapping Technique
- Chindipha, Stones D, Irwin, Barry V W
- Authors: Chindipha, Stones D , Irwin, Barry V W
- Date: 2021
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427665 , vital:72454 , https://www.researchgate.net/profile/Barry-Ir-win/publication/358895311_Feasibility_Study_Computing_Confidence_Inter-val_CI_for_IBR_Data_Using_Bootstrapping_Technique/links/621bdc469947d339eb6e578b/Feasibility-Study-Computing-Confidence-Interval-CI-for-IBR-Data-Using-Bootstrapping-Technique.pdf
- Description: Statistical bootstrapping has been used in different fields over the years since it was introduced as a technique that one can use to simulate data. In this study, parametric and nonparametric bootstrapping techniques were used to create samples of different compositions from the baseline data. The bootstrap distribution of a point estimator of a population parameter has been used in the past to produce a bootstrapped confidence interval (CI) for the parameter’s true value, if the parameter is written as a function of the population’s distribution. Population parameters are estimated with many point estimators. The study used mean as the population parameter of interest from which bootstrap samples were created. This research was more interested in the CI side of bootstrapping and it is this aspect that this paper focused on. This is the case because the study wanted to offer a certain degree of assurance and reliability of IBR data to users who may not have access to a larger ’lens’ of a network telescope to allow them to monitor security threats in their network. The primary interest in the dataset were source and destination IP (DSTIP) addresses, thus the study selected different size pools of DSTIP addresses to simulate bootstrap samples.
- Full Text:
- Date Issued: 2021
- Authors: Chindipha, Stones D , Irwin, Barry V W
- Date: 2021
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427665 , vital:72454 , https://www.researchgate.net/profile/Barry-Ir-win/publication/358895311_Feasibility_Study_Computing_Confidence_Inter-val_CI_for_IBR_Data_Using_Bootstrapping_Technique/links/621bdc469947d339eb6e578b/Feasibility-Study-Computing-Confidence-Interval-CI-for-IBR-Data-Using-Bootstrapping-Technique.pdf
- Description: Statistical bootstrapping has been used in different fields over the years since it was introduced as a technique that one can use to simulate data. In this study, parametric and nonparametric bootstrapping techniques were used to create samples of different compositions from the baseline data. The bootstrap distribution of a point estimator of a population parameter has been used in the past to produce a bootstrapped confidence interval (CI) for the parameter’s true value, if the parameter is written as a function of the population’s distribution. Population parameters are estimated with many point estimators. The study used mean as the population parameter of interest from which bootstrap samples were created. This research was more interested in the CI side of bootstrapping and it is this aspect that this paper focused on. This is the case because the study wanted to offer a certain degree of assurance and reliability of IBR data to users who may not have access to a larger ’lens’ of a network telescope to allow them to monitor security threats in their network. The primary interest in the dataset were source and destination IP (DSTIP) addresses, thus the study selected different size pools of DSTIP addresses to simulate bootstrap samples.
- Full Text:
- Date Issued: 2021
Field-based ecological studies to assess prospective biological control agents for invasive alien plants: An example from giant rat's tail grass
- Sutton, Guy F, Canavan, Kim N, Day, Michael M, Paterson, Iain D
- Authors: Sutton, Guy F , Canavan, Kim N , Day, Michael M , Paterson, Iain D
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423756 , vital:72091 , xlink:href="https://doi.org/10.1111/1365-2664.13834"
- Description: Biological control (biocontrol) of invasive alien plants is a widely utilised weed management tool. Prospective biocontrol agents are typically assessed through host specificity testing and pre-release efficacy studies performed in quarantine. However, rearing of the potential biocontrol agents and/or test plants is often difficult or impossible under quarantine conditions. Moreover, practitioners may attain laboratory artefacts in quarantine, which may result in the potential agent being needlessly rejected. Field-based studies in the weed's indigenous distribution could overcome these issues.
- Full Text:
- Date Issued: 2021
- Authors: Sutton, Guy F , Canavan, Kim N , Day, Michael M , Paterson, Iain D
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423756 , vital:72091 , xlink:href="https://doi.org/10.1111/1365-2664.13834"
- Description: Biological control (biocontrol) of invasive alien plants is a widely utilised weed management tool. Prospective biocontrol agents are typically assessed through host specificity testing and pre-release efficacy studies performed in quarantine. However, rearing of the potential biocontrol agents and/or test plants is often difficult or impossible under quarantine conditions. Moreover, practitioners may attain laboratory artefacts in quarantine, which may result in the potential agent being needlessly rejected. Field-based studies in the weed's indigenous distribution could overcome these issues.
- Full Text:
- Date Issued: 2021
Flavonoids from the Genus Euphorbia
- Magozwi, Douglas K, Dinala, Mmabatho, Mokwana, Nthabiseng, Siwe-Noundou, Xavier, Krause, Rui W M, Sonopo, Molahleli, McGaw, Lyndy J, Augustyn, Wilma A, Tembu, Vuyelwa J
- Authors: Magozwi, Douglas K , Dinala, Mmabatho , Mokwana, Nthabiseng , Siwe-Noundou, Xavier , Krause, Rui W M , Sonopo, Molahleli , McGaw, Lyndy J , Augustyn, Wilma A , Tembu, Vuyelwa J
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/191736 , vital:45159 , xlink:href="https://doi.org/10.3390/ph14050428"
- Description: Plants of the genus Euphorbia are widely distributed across temperate, tropical and subtropical regions of South America, Asia and Africa with established Ayurvedic, Chinese and Malay ethnomedical records. The present review reports the isolation, occurrence, phytochemistry, biological properties, therapeutic potential and structure–activity relationship of Euphorbia flavonoids for the period covering 2000–2020, while identifying potential areas for future studies aimed at development of new therapeutic agents from these plants. The findings suggest that the extracts and isolated flavonoids possess anticancer, antiproliferative, antimalarial, antibacterial, anti-venom, anti-inflammatory, anti-hepatitis and antioxidant properties and have different mechanisms of action against cancer cells. Of the investigated species, over 80 different types of flavonoids have been isolated to date. Most of the isolated flavonoids were flavonols and comprised simple O-substitution patterns, C-methylation and prenylation. Others had a glycoside, glycosidic linkages and a carbohydrate attached at either C-3 or C-7, and were designated as d-glucose, l-rhamnose or glucorhamnose. The structure–activity relationship studies showed that methylation of the hydroxyl groups on C-3 or C-7 reduces the activities while glycosylation loses the activity and that the parent skeletal structure is essential in retaining the activity. These constituents can therefore offer potential alternative scaffolds towards development of new Euphorbia-based therapeutic agents.
- Full Text:
- Date Issued: 2021
- Authors: Magozwi, Douglas K , Dinala, Mmabatho , Mokwana, Nthabiseng , Siwe-Noundou, Xavier , Krause, Rui W M , Sonopo, Molahleli , McGaw, Lyndy J , Augustyn, Wilma A , Tembu, Vuyelwa J
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/191736 , vital:45159 , xlink:href="https://doi.org/10.3390/ph14050428"
- Description: Plants of the genus Euphorbia are widely distributed across temperate, tropical and subtropical regions of South America, Asia and Africa with established Ayurvedic, Chinese and Malay ethnomedical records. The present review reports the isolation, occurrence, phytochemistry, biological properties, therapeutic potential and structure–activity relationship of Euphorbia flavonoids for the period covering 2000–2020, while identifying potential areas for future studies aimed at development of new therapeutic agents from these plants. The findings suggest that the extracts and isolated flavonoids possess anticancer, antiproliferative, antimalarial, antibacterial, anti-venom, anti-inflammatory, anti-hepatitis and antioxidant properties and have different mechanisms of action against cancer cells. Of the investigated species, over 80 different types of flavonoids have been isolated to date. Most of the isolated flavonoids were flavonols and comprised simple O-substitution patterns, C-methylation and prenylation. Others had a glycoside, glycosidic linkages and a carbohydrate attached at either C-3 or C-7, and were designated as d-glucose, l-rhamnose or glucorhamnose. The structure–activity relationship studies showed that methylation of the hydroxyl groups on C-3 or C-7 reduces the activities while glycosylation loses the activity and that the parent skeletal structure is essential in retaining the activity. These constituents can therefore offer potential alternative scaffolds towards development of new Euphorbia-based therapeutic agents.
- Full Text:
- Date Issued: 2021
Folic acid-modified phthalocyanine-nanozyme loaded liposomes for targeted photodynamic therapy
- Nwahara, Nnamdi, Abrahams, Garth, Prinsloo, Earl, Nyokong, Tebello
- Authors: Nwahara, Nnamdi , Abrahams, Garth , Prinsloo, Earl , Nyokong, Tebello
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/231369 , vital:49881 , xlink:href="https://doi.org/10.1016/j.pdpdt.2021.102527"
- Description: The hypoxic tumour microenvironment and poor spatiotemporal localization of photosensitizers are two significant obstacles that limit practical applications of photodynamic therapy. In response, a biocompatible, light-activatable liposome integrated with both a zinc phthalocyanine photodynamic component and Pt nanoparticles-decorated with MnO2 catalase-mimicking component are engineered. This multifunctional system was rationally designed using unsaturated phospholipids to achieve on-demand drug release following light irradiation. Specificity was achieved by folic acid functionalization resulting in folate-modified liposomes (FTLiposomes). We demonstrated its specific uptake by fluorescence imaging using folate receptor (FR) overexpressing HeLa and MCF-7 cells as in vitro models. This multifunctional liposome exhibits superior hypoxic anti-tumour effects and holds the potential to reduce side effects associated with untargeted therapy. Fluorescence of the constituent ZnPc and folate-receptor targeting could enable tracking and permit spatiotemporal regulation for improved cancer treatment.
- Full Text:
- Date Issued: 2021
- Authors: Nwahara, Nnamdi , Abrahams, Garth , Prinsloo, Earl , Nyokong, Tebello
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/231369 , vital:49881 , xlink:href="https://doi.org/10.1016/j.pdpdt.2021.102527"
- Description: The hypoxic tumour microenvironment and poor spatiotemporal localization of photosensitizers are two significant obstacles that limit practical applications of photodynamic therapy. In response, a biocompatible, light-activatable liposome integrated with both a zinc phthalocyanine photodynamic component and Pt nanoparticles-decorated with MnO2 catalase-mimicking component are engineered. This multifunctional system was rationally designed using unsaturated phospholipids to achieve on-demand drug release following light irradiation. Specificity was achieved by folic acid functionalization resulting in folate-modified liposomes (FTLiposomes). We demonstrated its specific uptake by fluorescence imaging using folate receptor (FR) overexpressing HeLa and MCF-7 cells as in vitro models. This multifunctional liposome exhibits superior hypoxic anti-tumour effects and holds the potential to reduce side effects associated with untargeted therapy. Fluorescence of the constituent ZnPc and folate-receptor targeting could enable tracking and permit spatiotemporal regulation for improved cancer treatment.
- Full Text:
- Date Issued: 2021
Force Field Parameters for Fe2+ 4S2− 4 Clusters of Dihydropyrimidine Dehydrogenase, the 5-Fluorouracil Cancer Drug Deactivation Protein: A Step towards In Silico Pharmacogenomics Studies
- Tendwa, Maureen B, Chebon-Bore, Lorna, Lobb, Kevin A, Musyoka, Thommas M, Taştan Bishop, Özlem
- Authors: Tendwa, Maureen B , Chebon-Bore, Lorna , Lobb, Kevin A , Musyoka, Thommas M , Taştan Bishop, Özlem
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/451078 , vital:75016 , xlink:href="https://doi.org/10.3390/molecules26102929 "
- Description: The dimeric dihydropyrimidine dehydrogenase (DPD), metalloenzyme, an adjunct anti-cancer drug target, contains highly specialized 4 × Fe2+4S2−4 clusters per chain. These clusters facilitate the catalysis of the rate-limiting step in the pyrimidine degradation pathway through a harmonized electron transfer cascade that triggers a redox catabolic reaction. In the process, the bulk of the administered 5-fluorouracil (5-FU) cancer drug is inactivated, while a small proportion is activated to nucleic acid antimetabolites. The occurrence of missense mutations in DPD protein within the general population, including those of African descent, has adverse toxicity effects due to altered 5-FU metabolism. Thus, deciphering mutation effects on protein structure and function is vital, especially for precision medicine purposes. We previously proposed combining molecular dynamics (MD) and dynamic residue network (DRN) analysis to decipher the molecular mechanisms of missense mutations in other proteins. However, the presence of Fe2+4S2−4 clusters in DPD poses a challenge for such in silico studies. The existing AMBER force field parameters cannot accurately describe the Fe2+ center coordination exhibited by this enzyme. Therefore, this study aimed to derive AMBER force field parameters for DPD enzyme Fe2+ centers, using the original Seminario method and the collation features Visual Force Field Derivation Toolkit as a supportive approach. All-atom MD simulations were performed to validate the results. Both approaches generated similar force field parameters, which accurately described the human DPD protein Fe2+4S2−4 cluster architecture. This information is crucial and opens new avenues for in silico cancer pharmacogenomics and drug discovery related research on 5-FU drug efficacy and toxicity issues.
- Full Text:
- Date Issued: 2021
- Authors: Tendwa, Maureen B , Chebon-Bore, Lorna , Lobb, Kevin A , Musyoka, Thommas M , Taştan Bishop, Özlem
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/451078 , vital:75016 , xlink:href="https://doi.org/10.3390/molecules26102929 "
- Description: The dimeric dihydropyrimidine dehydrogenase (DPD), metalloenzyme, an adjunct anti-cancer drug target, contains highly specialized 4 × Fe2+4S2−4 clusters per chain. These clusters facilitate the catalysis of the rate-limiting step in the pyrimidine degradation pathway through a harmonized electron transfer cascade that triggers a redox catabolic reaction. In the process, the bulk of the administered 5-fluorouracil (5-FU) cancer drug is inactivated, while a small proportion is activated to nucleic acid antimetabolites. The occurrence of missense mutations in DPD protein within the general population, including those of African descent, has adverse toxicity effects due to altered 5-FU metabolism. Thus, deciphering mutation effects on protein structure and function is vital, especially for precision medicine purposes. We previously proposed combining molecular dynamics (MD) and dynamic residue network (DRN) analysis to decipher the molecular mechanisms of missense mutations in other proteins. However, the presence of Fe2+4S2−4 clusters in DPD poses a challenge for such in silico studies. The existing AMBER force field parameters cannot accurately describe the Fe2+ center coordination exhibited by this enzyme. Therefore, this study aimed to derive AMBER force field parameters for DPD enzyme Fe2+ centers, using the original Seminario method and the collation features Visual Force Field Derivation Toolkit as a supportive approach. All-atom MD simulations were performed to validate the results. Both approaches generated similar force field parameters, which accurately described the human DPD protein Fe2+4S2−4 cluster architecture. This information is crucial and opens new avenues for in silico cancer pharmacogenomics and drug discovery related research on 5-FU drug efficacy and toxicity issues.
- Full Text:
- Date Issued: 2021
Formative Assessment for Quality Environmental Learning in Natural Sciences Classrooms
- Mgoqi, Nomvuyo, Schudel, Ingrid J
- Authors: Mgoqi, Nomvuyo , Schudel, Ingrid J
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/435127 , vital:73132 , ISBN 9781928502241 , https://library.oapen.org/handle/20.500.12657/64082
- Description: The study that informs this chapter aimed at exploring how teachers used formative assessment strategies to support higher order thinking in environmental topics taught in Natural Sciences classrooms (Mgoqi 2019). Higher order thinking is used widely by educational curriculum developers and assessment experts to design test items that measure a variety of thinking skills (Haladyna 2004). For example, the Curriculum Assessment Policy Statement (CAPS) Natural Sciences developers have framed low, middle and high order cognitive levels for guiding classroom assessment (South Africa DBE 2011). These levels describe the way in which learners are expected to work with knowledge as follows: knowing (low order); understanding and applying (medium order); and evaluating, analysing and synthesising (high order). These cognitive levels are closely linked to Bloom’s Taxonomy of Learning which Zohar and Dori (2003) used to describe higher order thinking as analysing, evaluating and creating. These latter three levels build on the lower order thinking levels of remembering, understanding and applying. These higher order thinking skills are important for environmental learning which promotes ‘critical thinking, understanding complex systems, imagining future scenarios, and making decisions in a participatory and collaborative way’ (Unesco 2014: 33). In this chapter, a revised Bloom’s Taxonomy as proposed by Krathwohl (2002) is discussed and used as a lens to review the cognitive levels evident in the activities planned and implemented by teachers.
- Full Text:
- Date Issued: 2021
- Authors: Mgoqi, Nomvuyo , Schudel, Ingrid J
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/435127 , vital:73132 , ISBN 9781928502241 , https://library.oapen.org/handle/20.500.12657/64082
- Description: The study that informs this chapter aimed at exploring how teachers used formative assessment strategies to support higher order thinking in environmental topics taught in Natural Sciences classrooms (Mgoqi 2019). Higher order thinking is used widely by educational curriculum developers and assessment experts to design test items that measure a variety of thinking skills (Haladyna 2004). For example, the Curriculum Assessment Policy Statement (CAPS) Natural Sciences developers have framed low, middle and high order cognitive levels for guiding classroom assessment (South Africa DBE 2011). These levels describe the way in which learners are expected to work with knowledge as follows: knowing (low order); understanding and applying (medium order); and evaluating, analysing and synthesising (high order). These cognitive levels are closely linked to Bloom’s Taxonomy of Learning which Zohar and Dori (2003) used to describe higher order thinking as analysing, evaluating and creating. These latter three levels build on the lower order thinking levels of remembering, understanding and applying. These higher order thinking skills are important for environmental learning which promotes ‘critical thinking, understanding complex systems, imagining future scenarios, and making decisions in a participatory and collaborative way’ (Unesco 2014: 33). In this chapter, a revised Bloom’s Taxonomy as proposed by Krathwohl (2002) is discussed and used as a lens to review the cognitive levels evident in the activities planned and implemented by teachers.
- Full Text:
- Date Issued: 2021