Decoration of glass wool with zinc (II) phthalocyanine for the photocatalytic transformation of methyl orange
- Sindelo, Azole, Britton, Jonathan, Lanterna, Anabel E, Scaiano, Juan C, Nyokong, Tebello
- Authors: Sindelo, Azole , Britton, Jonathan , Lanterna, Anabel E , Scaiano, Juan C , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295742 , vital:57374 , xlink:href="https://doi.org/10.1016/j.jphotochem.2022.114127"
- Description: Zinc phthalocyanines containing one (mono carboxy phenoxy, ZnMCPPc), four (tetra carboxy phenoxy, ZnTCPPc), and eight (tetra isophthalic acid, ZnTIPAPc) carboxyl groups were covalently conjugated to amine-functionalized glass wool (GW). The GW-Pcs were characterized and evaluated for singlet oxygen generation. The photocatalytic efficiencies of the GW-Pcs were assessed using methyl orange. Glass wool alone and the modified conjugates exhibited low to no degradation of methyl orange in the dark. The improved catalytic rate was observed for GW-ZnMCPPc and GW-ZnTCPPc compared to GW-ZnTIPAPc due to the latter's lower singlet oxygen quantum yield generation. In addition, the modified glass wool was recyclable, making it suitable candidates for future environmental applications.
- Full Text:
- Date Issued: 2022
- Authors: Sindelo, Azole , Britton, Jonathan , Lanterna, Anabel E , Scaiano, Juan C , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295742 , vital:57374 , xlink:href="https://doi.org/10.1016/j.jphotochem.2022.114127"
- Description: Zinc phthalocyanines containing one (mono carboxy phenoxy, ZnMCPPc), four (tetra carboxy phenoxy, ZnTCPPc), and eight (tetra isophthalic acid, ZnTIPAPc) carboxyl groups were covalently conjugated to amine-functionalized glass wool (GW). The GW-Pcs were characterized and evaluated for singlet oxygen generation. The photocatalytic efficiencies of the GW-Pcs were assessed using methyl orange. Glass wool alone and the modified conjugates exhibited low to no degradation of methyl orange in the dark. The improved catalytic rate was observed for GW-ZnMCPPc and GW-ZnTCPPc compared to GW-ZnTIPAPc due to the latter's lower singlet oxygen quantum yield generation. In addition, the modified glass wool was recyclable, making it suitable candidates for future environmental applications.
- Full Text:
- Date Issued: 2022
Deep Palmprint Recognition with Alignment and Augmentation of Limited Training Samples
- Brown, Dane, Bradshaw, Karen L
- Authors: Brown, Dane , Bradshaw, Karen L
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440249 , vital:73760 , xlink:href="https://doi.org/10.1007/s42979-021-00859-3"
- Description: This paper builds upon a previously proposed automatic palmprint alignment and classification system. The proposed system was geared towards palmprints acquired from either contact or contactless sensors. It was robust to finger location and fist shape changes—accurately extracting the palmprints in images without fingers. An extension to this previous work includes comparisons of traditional and deep learning models, both with hyperparameter tuning. The proposed methods are compared with related verification systems and a detailed evaluation of open-set identification. The best results were yielded by a proposed Convolutional Neural Network, based on VGG-16, and outperforming tuned VGG-16 and Xception architectures. All deep learning algorithms are provided with augmented data, included in the tuning process, enabling significant accuracy gains. Highlights include near-zero and zero EER on IITD-Palmprint verification using one training sample and leave-one-out strategy, respectively. Therefore, the proposed palmprint system is practical as it is effective on data containing many and few training examples.
- Full Text:
- Date Issued: 2022
- Authors: Brown, Dane , Bradshaw, Karen L
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440249 , vital:73760 , xlink:href="https://doi.org/10.1007/s42979-021-00859-3"
- Description: This paper builds upon a previously proposed automatic palmprint alignment and classification system. The proposed system was geared towards palmprints acquired from either contact or contactless sensors. It was robust to finger location and fist shape changes—accurately extracting the palmprints in images without fingers. An extension to this previous work includes comparisons of traditional and deep learning models, both with hyperparameter tuning. The proposed methods are compared with related verification systems and a detailed evaluation of open-set identification. The best results were yielded by a proposed Convolutional Neural Network, based on VGG-16, and outperforming tuned VGG-16 and Xception architectures. All deep learning algorithms are provided with augmented data, included in the tuning process, enabling significant accuracy gains. Highlights include near-zero and zero EER on IITD-Palmprint verification using one training sample and leave-one-out strategy, respectively. Therefore, the proposed palmprint system is practical as it is effective on data containing many and few training examples.
- Full Text:
- Date Issued: 2022
Design and fabrication of electrochemical sensor based on molecularly imprinted polymer loaded onto silver nanoparticles for the detection of 17-β-Estradiol
- Regasa, Melkamu Biyana, Nyokong, Tebello
- Authors: Regasa, Melkamu Biyana , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300287 , vital:57913 , xlink:href="https://doi.org/10.1002/jmr.2978"
- Description: In this research report, we prepared an electrochemical sensor based on the molecularly imprinted poly(p-aminophenol) supported by silver nanoparticles capped with 2-mercaptobenzoxazole for the selective and sensitive detection of endocrine disrupting 17-β-estradiol (E2). The electropolymerization of the functional monomer prepared the proposed molecularly imprinted polymer (MIP) composite-based sensor in the presence of E2 as a template. The recognition materials were characterized using Fourier transform infrared, cyclic voltammetry (CV), square wave voltammetry (SWV), scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray powder diffraction techniques. The electrochemical measurements were performed by employing both CV and SWV methods. We did the optimization of critical parameters affecting the sensor performances through the experimental design and verification. The developed sensor showed a linear range from 10 pM to 100 nM with the calculated quantification and detection limits of 1.86 and 6.19 pM, respectively. The incorporation of AgNP with high electrical conductivity into the MIP matrix enhanced the sensor's performance. Furthermore, the sensor was applied to determine E2 in real water samples without any sample preconcentration steps to achieve the percent recovery of 91.87% to 98.36% and acceptable reusability and storage stability performances.
- Full Text:
- Date Issued: 2022
- Authors: Regasa, Melkamu Biyana , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300287 , vital:57913 , xlink:href="https://doi.org/10.1002/jmr.2978"
- Description: In this research report, we prepared an electrochemical sensor based on the molecularly imprinted poly(p-aminophenol) supported by silver nanoparticles capped with 2-mercaptobenzoxazole for the selective and sensitive detection of endocrine disrupting 17-β-estradiol (E2). The electropolymerization of the functional monomer prepared the proposed molecularly imprinted polymer (MIP) composite-based sensor in the presence of E2 as a template. The recognition materials were characterized using Fourier transform infrared, cyclic voltammetry (CV), square wave voltammetry (SWV), scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray powder diffraction techniques. The electrochemical measurements were performed by employing both CV and SWV methods. We did the optimization of critical parameters affecting the sensor performances through the experimental design and verification. The developed sensor showed a linear range from 10 pM to 100 nM with the calculated quantification and detection limits of 1.86 and 6.19 pM, respectively. The incorporation of AgNP with high electrical conductivity into the MIP matrix enhanced the sensor's performance. Furthermore, the sensor was applied to determine E2 in real water samples without any sample preconcentration steps to achieve the percent recovery of 91.87% to 98.36% and acceptable reusability and storage stability performances.
- Full Text:
- Date Issued: 2022
Detecting and removing sample contamination in phylogenomic data: an example and its implications for Cicadidae phylogeny (Insecta Hemiptera).
- Owen, Christopher L, Marshall, David C, Wade, Elizabeth J, Meister, Russ, Goemans, Geert, Kunte, Krushnamegh, Moulds, Max, Hill, Kathy, Villet, Martin H, Pham, Thai-Hong, Kortyna, Michelle, Lemmon, Emily M, Lemmon, Alan R, Simon, Chris
- Authors: Owen, Christopher L , Marshall, David C , Wade, Elizabeth J , Meister, Russ , Goemans, Geert , Kunte, Krushnamegh , Moulds, Max , Hill, Kathy , Villet, Martin H , Pham, Thai-Hong , Kortyna, Michelle , Lemmon, Emily M , Lemmon, Alan R , Simon, Chris
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440749 , vital:73809 , https://doi.org/10.1093/sysbio/syac043
- Description: Contamination of a genetic sample with DNA from one or more nontarget species is a continuing concern of molecular phylogenetic studies, both Sanger sequencing studies and next-generation sequencing studies. We developed an automated pipeline for identifying and excluding likely cross-contaminated loci based on the detection of bimodal distributions of patristic distances across gene trees. When contamination occurs between samples within a data set, a comparison between a contaminated sample and its contaminant taxon will yield bimodal distributions with one peak close to zero patristic distance. This new method does not rely on a priori knowledge of taxon relatedness nor does it determine the causes(s) of the contamination. Exclusion of putatively contaminated loci from a data set generated for the insect family Cicadidae showed that these sequences were affecting some topological patterns and branch supports, although the effects were sometimes subtle, with some contamination-influenced relationships exhibiting strong bootstrap support. Long tip branches and outlier values for one anchored phylogenomic pipeline statistic (AvgNHomologs) were correlated with the presence of contamination.
- Full Text:
- Date Issued: 2022
- Authors: Owen, Christopher L , Marshall, David C , Wade, Elizabeth J , Meister, Russ , Goemans, Geert , Kunte, Krushnamegh , Moulds, Max , Hill, Kathy , Villet, Martin H , Pham, Thai-Hong , Kortyna, Michelle , Lemmon, Emily M , Lemmon, Alan R , Simon, Chris
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440749 , vital:73809 , https://doi.org/10.1093/sysbio/syac043
- Description: Contamination of a genetic sample with DNA from one or more nontarget species is a continuing concern of molecular phylogenetic studies, both Sanger sequencing studies and next-generation sequencing studies. We developed an automated pipeline for identifying and excluding likely cross-contaminated loci based on the detection of bimodal distributions of patristic distances across gene trees. When contamination occurs between samples within a data set, a comparison between a contaminated sample and its contaminant taxon will yield bimodal distributions with one peak close to zero patristic distance. This new method does not rely on a priori knowledge of taxon relatedness nor does it determine the causes(s) of the contamination. Exclusion of putatively contaminated loci from a data set generated for the insect family Cicadidae showed that these sequences were affecting some topological patterns and branch supports, although the effects were sometimes subtle, with some contamination-influenced relationships exhibiting strong bootstrap support. Long tip branches and outlier values for one anchored phylogenomic pipeline statistic (AvgNHomologs) were correlated with the presence of contamination.
- Full Text:
- Date Issued: 2022
Developing Relationships for Community-Based Research at Rhodes University: Values, Principles and Challenges
- Rouillard, Tessa, Deponselle, Keagan, Bezerra, Joana C
- Authors: Rouillard, Tessa , Deponselle, Keagan , Bezerra, Joana C
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426430 , vital:72352 , xlink:href="https://doi.org/10.3390/su142315525"
- Description: In addition to providing benefits to people, protected areas are valued in ways that go beyond the tangible. A sense of place, and the collection of values, feelings, and meanings associated with a place, can illuminate people-place relationships. Understanding how people relate to a place is essential in acquiring support for protected areas. This research investigates tourists’ and residents’ sense of place in Knysna, an open-access section of the Garden Route National Park, South Africa. Data was collected through questionnaires and semi-structured interviews. The sense of place was characterised using five variables: physical, cultural, social, dependent, and ideological. Although ‘physical’ was the dominant variable for both tourists and residents, the ‘ideological’ for residents and the ‘cultural’ for tourists came second, highlighting the importance of safe places and recreational activities, respectively. The physical environment influences sense of place, and the importance of protected areas to stakeholders offers an opportunity for management to engage with the public.
- Full Text:
- Date Issued: 2022
- Authors: Rouillard, Tessa , Deponselle, Keagan , Bezerra, Joana C
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426430 , vital:72352 , xlink:href="https://doi.org/10.3390/su142315525"
- Description: In addition to providing benefits to people, protected areas are valued in ways that go beyond the tangible. A sense of place, and the collection of values, feelings, and meanings associated with a place, can illuminate people-place relationships. Understanding how people relate to a place is essential in acquiring support for protected areas. This research investigates tourists’ and residents’ sense of place in Knysna, an open-access section of the Garden Route National Park, South Africa. Data was collected through questionnaires and semi-structured interviews. The sense of place was characterised using five variables: physical, cultural, social, dependent, and ideological. Although ‘physical’ was the dominant variable for both tourists and residents, the ‘ideological’ for residents and the ‘cultural’ for tourists came second, highlighting the importance of safe places and recreational activities, respectively. The physical environment influences sense of place, and the importance of protected areas to stakeholders offers an opportunity for management to engage with the public.
- Full Text:
- Date Issued: 2022
Developing Relationships for Community-Based Research at Rhodes University: Values, Principles and Challenges
- Hornby, Diana, Maistry, Savathrie M
- Authors: Hornby, Diana , Maistry, Savathrie M
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433524 , vital:72981 , ISBN 978-3-030-86401-9 , https://doi.org/10.1007/978-3-030-86402-6_6
- Description: Post-apartheid education policy in South Africa mandates that universities should become more responsive to the socio-economic development of the country, positioning community engagement as a core function of higher education. Community engagement in all its forms, and particularly in the form of community-based research, should develop the social responsibility of both students and the institution by providing opportunities for partnering in community-based projects to promote the social good, thus narrowing the gap between universities and communities. The Community Engagement Division at Rhodes University in the Eastern Cape province of South Africa, supported by the highest level of management of the institution, was fully aware that removal of the ‘ivory tower’ image was a herculean task. Thus, they developed a set of values and principles to guide the establishment of community partnerships with the community the university serves. This chapter explains these values and principles, using the Reviving Schools community engagement initiative as an example. It discusses some of the challenges experienced and how they were overcome to build research relationships and a sense of ‘community’ between Rhodes University and its external partners in Makhanda.
- Full Text:
- Date Issued: 2022
- Authors: Hornby, Diana , Maistry, Savathrie M
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433524 , vital:72981 , ISBN 978-3-030-86401-9 , https://doi.org/10.1007/978-3-030-86402-6_6
- Description: Post-apartheid education policy in South Africa mandates that universities should become more responsive to the socio-economic development of the country, positioning community engagement as a core function of higher education. Community engagement in all its forms, and particularly in the form of community-based research, should develop the social responsibility of both students and the institution by providing opportunities for partnering in community-based projects to promote the social good, thus narrowing the gap between universities and communities. The Community Engagement Division at Rhodes University in the Eastern Cape province of South Africa, supported by the highest level of management of the institution, was fully aware that removal of the ‘ivory tower’ image was a herculean task. Thus, they developed a set of values and principles to guide the establishment of community partnerships with the community the university serves. This chapter explains these values and principles, using the Reviving Schools community engagement initiative as an example. It discusses some of the challenges experienced and how they were overcome to build research relationships and a sense of ‘community’ between Rhodes University and its external partners in Makhanda.
- Full Text:
- Date Issued: 2022
Development and in vitro biological studies of polymer-based wound dressings with a high haemostatic ability for the management of wounds
- Nqoro, Xhamla https://orcid.org/0000-0002-2065-3629
- Authors: Nqoro, Xhamla https://orcid.org/0000-0002-2065-3629
- Date: 2022
- Subjects: Wound healing , Surgical wound infections , Wound treatment equipment industry
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/27970 , vital:71404
- Description: Wounds are usually accompanied by complications such as excessive bleeding and bacteria invasion. The design of wound dressings that rapidly stop excessive bleeding and inhibit bacterial invasion is crucial to promoting accelerated wound healing. To meet the abovementioned requirements in wound dressings, topical gels were prepared from sodium alginate SA and carboxymethylcellulose CMC. The wound dressings were loaded with an antifibrinolytic agent, tranexamic acid TA, essential oils, and a variety of metal-based nanoparticles, and carbon-based biomaterials. The scanning electron microscopy SEM and X-ray diffraction XRD confirmed the successful formation of the nanoparticles. The prepared formulations exhibited in vitro drug release kinetics that best fitted with the Korsmeyer-Peppas model. These gels exhibited good spreadability and viscosity, showing a shear-thinning behaviour with pH between 6.7 and 7.3, signifying suitability for skin application and ease of application. The prepared topical gels exhibited significant antibacterial effects against gram-negative and gram-positive strains of bacteria. SA EO-based formulations showed high antibacterial activity across all bacterial strains, followed by SA-based formulations compared to CMC-based formulations, which exhibited moderate antibacterial activity. Moreover, the prepared gels showed good cytocompatibility, promoted cell proliferation, and exhibited 80 percent wound closure on day 3 compared to the untreated group, which showed a 38 percent wound reduction in vitro. Excellent blood clotting properties were observed with CMC-based gels compared to other formulations. However, all the prepared formulations exhibited outstanding blood clotting ability compared to the control, showing that they can promote rapid blood coagulation. The features presented by the prepared gels reveal that they are suitable for rapid wound healing , Thesis (PhD) -- Faculty of Science and Agriculture, 2022
- Full Text:
- Date Issued: 2022
- Authors: Nqoro, Xhamla https://orcid.org/0000-0002-2065-3629
- Date: 2022
- Subjects: Wound healing , Surgical wound infections , Wound treatment equipment industry
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/27970 , vital:71404
- Description: Wounds are usually accompanied by complications such as excessive bleeding and bacteria invasion. The design of wound dressings that rapidly stop excessive bleeding and inhibit bacterial invasion is crucial to promoting accelerated wound healing. To meet the abovementioned requirements in wound dressings, topical gels were prepared from sodium alginate SA and carboxymethylcellulose CMC. The wound dressings were loaded with an antifibrinolytic agent, tranexamic acid TA, essential oils, and a variety of metal-based nanoparticles, and carbon-based biomaterials. The scanning electron microscopy SEM and X-ray diffraction XRD confirmed the successful formation of the nanoparticles. The prepared formulations exhibited in vitro drug release kinetics that best fitted with the Korsmeyer-Peppas model. These gels exhibited good spreadability and viscosity, showing a shear-thinning behaviour with pH between 6.7 and 7.3, signifying suitability for skin application and ease of application. The prepared topical gels exhibited significant antibacterial effects against gram-negative and gram-positive strains of bacteria. SA EO-based formulations showed high antibacterial activity across all bacterial strains, followed by SA-based formulations compared to CMC-based formulations, which exhibited moderate antibacterial activity. Moreover, the prepared gels showed good cytocompatibility, promoted cell proliferation, and exhibited 80 percent wound closure on day 3 compared to the untreated group, which showed a 38 percent wound reduction in vitro. Excellent blood clotting properties were observed with CMC-based gels compared to other formulations. However, all the prepared formulations exhibited outstanding blood clotting ability compared to the control, showing that they can promote rapid blood coagulation. The features presented by the prepared gels reveal that they are suitable for rapid wound healing , Thesis (PhD) -- Faculty of Science and Agriculture, 2022
- Full Text:
- Date Issued: 2022
Digitalisation and Transformative Learning for Sustainable Futures in Rural Africa Leaving No One Behind
- Shetye, Nyanta, Lotz-Sisitka, Heila, Albrecht, Eike, Durr, Sarah, Marx, Dirk, Chirambo, Dumisani, Metelerkamp, Luke, van Zyl-Bulitta, Verena
- Authors: Shetye, Nyanta , Lotz-Sisitka, Heila , Albrecht, Eike , Durr, Sarah , Marx, Dirk , Chirambo, Dumisani , Metelerkamp, Luke , van Zyl-Bulitta, Verena
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/435263 , vital:73143 , ISBN 9781928502241 , https://www.taylorfrancis.com/chapters/oa-edit/10.4324/9781003274322-14/digitalisation-transformative-learning-sustainable-futures-rural-africa-niyanta-shetye-heila-lotz-sisitka-eike-albrecht-sarah-durr-dirk-marx-dumisani-chirambo-luke-metelerkamp-verena-van-zyl-bulitta
- Description: This chapter assesses the use of Information and Telecommunication Technologies (ICTs) for social and community learning to achieve sustainable development in rural communities in Africa. It focuses on new and emerging trends in the cooperation between the African Union and European Union (AU–EU) and links two thematic areas; namely green transitions and digital transformations. The chapter highlights low-cost and effective digital learning solutions. It is based on a literature review and cases that provide insight into potential AU–EU cooperation and the “leave no one behind” agenda. The chapter argues that in addition to digital technology transfer, innovation and investments are needed in building a learning-centred support for green transitioning and digital cooperation. Hence, we focus on transformative learning opportunities and informal Education for Sustainable Development (ESD). In response to ICTs becoming a catalyst for such a transformation, we seek insights into how constructive AU–EU cooperation and co-learning can pave ways for societal transformations, particularly in rural communities.
- Full Text:
- Date Issued: 2022
- Authors: Shetye, Nyanta , Lotz-Sisitka, Heila , Albrecht, Eike , Durr, Sarah , Marx, Dirk , Chirambo, Dumisani , Metelerkamp, Luke , van Zyl-Bulitta, Verena
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/435263 , vital:73143 , ISBN 9781928502241 , https://www.taylorfrancis.com/chapters/oa-edit/10.4324/9781003274322-14/digitalisation-transformative-learning-sustainable-futures-rural-africa-niyanta-shetye-heila-lotz-sisitka-eike-albrecht-sarah-durr-dirk-marx-dumisani-chirambo-luke-metelerkamp-verena-van-zyl-bulitta
- Description: This chapter assesses the use of Information and Telecommunication Technologies (ICTs) for social and community learning to achieve sustainable development in rural communities in Africa. It focuses on new and emerging trends in the cooperation between the African Union and European Union (AU–EU) and links two thematic areas; namely green transitions and digital transformations. The chapter highlights low-cost and effective digital learning solutions. It is based on a literature review and cases that provide insight into potential AU–EU cooperation and the “leave no one behind” agenda. The chapter argues that in addition to digital technology transfer, innovation and investments are needed in building a learning-centred support for green transitioning and digital cooperation. Hence, we focus on transformative learning opportunities and informal Education for Sustainable Development (ESD). In response to ICTs becoming a catalyst for such a transformation, we seek insights into how constructive AU–EU cooperation and co-learning can pave ways for societal transformations, particularly in rural communities.
- Full Text:
- Date Issued: 2022
Double stimulation and transformative agency for leadership development of school learners in Southern Africa
- Authors: Grant, Carolyn
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281035 , vital:55685 , xlink:href="https://doi.org/10.1080/14681366.2020.1805495"
- Description: Learners, because of their minor status, are a virtual absence in everyday school leadership work, particularly on the African continent. School leadership, therefore, continues to be misconceived as an adult phenomenon. Framed by Cultural Historical Activity Theory, this paper reports on a Southern African Higher Education studythat engages with the Vygotskian principle of ‘double stimulation’ and its relationship to transformative agency in the context of a school-based learner leadership development initiative. One school change project was purposively selected as the case, and data were drawn from a postgraduate student research report and self-reflective journal. Drawing on the Sannino model of double stimulation, the paper explores the phases of double stimulation as well as instances of transformative agency evident in the data, and speculates about the relationship between double stimulation and transformative agency in the leadership development of learners.
- Full Text:
- Date Issued: 2022
- Authors: Grant, Carolyn
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281035 , vital:55685 , xlink:href="https://doi.org/10.1080/14681366.2020.1805495"
- Description: Learners, because of their minor status, are a virtual absence in everyday school leadership work, particularly on the African continent. School leadership, therefore, continues to be misconceived as an adult phenomenon. Framed by Cultural Historical Activity Theory, this paper reports on a Southern African Higher Education studythat engages with the Vygotskian principle of ‘double stimulation’ and its relationship to transformative agency in the context of a school-based learner leadership development initiative. One school change project was purposively selected as the case, and data were drawn from a postgraduate student research report and self-reflective journal. Drawing on the Sannino model of double stimulation, the paper explores the phases of double stimulation as well as instances of transformative agency evident in the data, and speculates about the relationship between double stimulation and transformative agency in the leadership development of learners.
- Full Text:
- Date Issued: 2022
Drowning in data, thirsty for information and starved for understanding: A biodiversity information hub for cooperative environmental monitoring in South Africa
- MacFadyen, Sandra, Allsopp, Nicky, Altwegg, Res, Archibald, Sally, Botha, Judith, Bradshaw, Karen L, Carruthers, Jane, De Klerk, Helen, de Vos, Alta, Distiller, Greg, Foord, Stefan, Freitag-Ronaldson, Stefanie, Gibbs, Richard, Hamer, Michelle, Landi, Pietro, MacFayden, Duncan, Manuel, Jeffrey, Midgley, Guy, Moncrieff, Glenn, Munch, Zahn, Mutanga, Onisimo, Sershen, Nenguda, Rendani, Ngwenya, Mzabalazo, Parker, Daniel M, Peel, Mike, Power, John, Pretorius, Joachim, Ramdhani, Syd, Robertson, Mark P, Rushworth, Ian, Skowno, Andrew, Slingsby, Jasper, Turner, Andrew, Visser, Vernon, van Wageningen, Gerhard, Hui, Cang
- Authors: MacFadyen, Sandra , Allsopp, Nicky , Altwegg, Res , Archibald, Sally , Botha, Judith , Bradshaw, Karen L , Carruthers, Jane , De Klerk, Helen , de Vos, Alta , Distiller, Greg , Foord, Stefan , Freitag-Ronaldson, Stefanie , Gibbs, Richard , Hamer, Michelle , Landi, Pietro , MacFayden, Duncan , Manuel, Jeffrey , Midgley, Guy , Moncrieff, Glenn , Munch, Zahn , Mutanga, Onisimo , Sershen , Nenguda, Rendani , Ngwenya, Mzabalazo , Parker, Daniel M , Peel, Mike , Power, John , Pretorius, Joachim , Ramdhani, Syd , Robertson, Mark P , Rushworth, Ian , Skowno, Andrew , Slingsby, Jasper , Turner, Andrew , Visser, Vernon , van Wageningen, Gerhard , Hui, Cang
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/415624 , vital:71271 , xlink:href="https://doi.org/10.1016/j.biocon.2022.109736"
- Description: The world is firmly cemented in a notitian age (Latin: notitia, meaning data) – drowning in data, yet thirsty for information and the synthesis of knowledge into understanding. As concerns over biodiversity declines escalate, the volume, diversity and speed at which new environmental and ecological data are generated has increased exponentially. Data availability primes the research and discovery engine driving biodiversity conservation. South Africa (SA) is poised to become a world leader in biodiversity conservation. However, continent-wide resource limitations hamper the establishment of inclusive technologies and robust platforms and tools for biodiversity informatics. In this perspectives piece, we bring together the opinions of 37 co-authors from 20 different departments, across 10 SA universities, 7 national and provincial conservation research agencies, and various institutes and private conservation, research and management bodies, to develop a way forward for biodiversity informatics in SA. We propose the development of a SA Biodiversity Informatics Hub and describe the essential components necessary for its design, implementation and sustainability. We emphasise the importance of developing a culture of cooperation, collaboration and interoperability among custodians of biodiversity data to establish operational workflows for data synthesis. However, our biggest challenges are misgivings around data sharing and multidisciplinary collaboration.
- Full Text:
- Date Issued: 2022
- Authors: MacFadyen, Sandra , Allsopp, Nicky , Altwegg, Res , Archibald, Sally , Botha, Judith , Bradshaw, Karen L , Carruthers, Jane , De Klerk, Helen , de Vos, Alta , Distiller, Greg , Foord, Stefan , Freitag-Ronaldson, Stefanie , Gibbs, Richard , Hamer, Michelle , Landi, Pietro , MacFayden, Duncan , Manuel, Jeffrey , Midgley, Guy , Moncrieff, Glenn , Munch, Zahn , Mutanga, Onisimo , Sershen , Nenguda, Rendani , Ngwenya, Mzabalazo , Parker, Daniel M , Peel, Mike , Power, John , Pretorius, Joachim , Ramdhani, Syd , Robertson, Mark P , Rushworth, Ian , Skowno, Andrew , Slingsby, Jasper , Turner, Andrew , Visser, Vernon , van Wageningen, Gerhard , Hui, Cang
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/415624 , vital:71271 , xlink:href="https://doi.org/10.1016/j.biocon.2022.109736"
- Description: The world is firmly cemented in a notitian age (Latin: notitia, meaning data) – drowning in data, yet thirsty for information and the synthesis of knowledge into understanding. As concerns over biodiversity declines escalate, the volume, diversity and speed at which new environmental and ecological data are generated has increased exponentially. Data availability primes the research and discovery engine driving biodiversity conservation. South Africa (SA) is poised to become a world leader in biodiversity conservation. However, continent-wide resource limitations hamper the establishment of inclusive technologies and robust platforms and tools for biodiversity informatics. In this perspectives piece, we bring together the opinions of 37 co-authors from 20 different departments, across 10 SA universities, 7 national and provincial conservation research agencies, and various institutes and private conservation, research and management bodies, to develop a way forward for biodiversity informatics in SA. We propose the development of a SA Biodiversity Informatics Hub and describe the essential components necessary for its design, implementation and sustainability. We emphasise the importance of developing a culture of cooperation, collaboration and interoperability among custodians of biodiversity data to establish operational workflows for data synthesis. However, our biggest challenges are misgivings around data sharing and multidisciplinary collaboration.
- Full Text:
- Date Issued: 2022
Drug Resistance in the HIV-1 Subtype C Protease Enzyme: A High Throughput Virtual Screening Approach in Search of New Ligands with Activity
- Sarron, Arthur F D, Lobb, Kevin A
- Authors: Sarron, Arthur F D , Lobb, Kevin A
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/452699 , vital:75163 , xlink:href="10.2174/1871520622666220202161543"
- Description: Background: HIV-1 subtype C protease is a strategic target for antiretroviral treatment. However, resistance to protease inhibi-tors appears after months of treatment. Chromones and 2- bis-coumarin derivatives show potential for inhibition of the HIV- subtype C protease. Objective: Different heterocyclic structures from the ZINC database were docked against Human Immuno-deficiency Virus-1 (HIV) subtype C protease crystal structure 2R5Q and 2R5P. The 5 best molecules were selected to be docked against 62 homology models based on HIV-protease se-quences from infants failing antiretroviral protease treatment. This experimentation was performed with two molecular docking programs: Autodock and Autodock Vina. These molecules were modified by substituting protons with different moieties, and the derivatives were docked against the same targets. Ligand-protein interactions, physical/chemical proprieties of the mole-cules, and dynamics simulations were analyzed.
- Full Text:
- Date Issued: 2022
- Authors: Sarron, Arthur F D , Lobb, Kevin A
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/452699 , vital:75163 , xlink:href="10.2174/1871520622666220202161543"
- Description: Background: HIV-1 subtype C protease is a strategic target for antiretroviral treatment. However, resistance to protease inhibi-tors appears after months of treatment. Chromones and 2- bis-coumarin derivatives show potential for inhibition of the HIV- subtype C protease. Objective: Different heterocyclic structures from the ZINC database were docked against Human Immuno-deficiency Virus-1 (HIV) subtype C protease crystal structure 2R5Q and 2R5P. The 5 best molecules were selected to be docked against 62 homology models based on HIV-protease se-quences from infants failing antiretroviral protease treatment. This experimentation was performed with two molecular docking programs: Autodock and Autodock Vina. These molecules were modified by substituting protons with different moieties, and the derivatives were docked against the same targets. Ligand-protein interactions, physical/chemical proprieties of the mole-cules, and dynamics simulations were analyzed.
- Full Text:
- Date Issued: 2022
Ecosystem for 4th industrial revolution to accelerate sustainable development goals in the South Africa’,‘n context: a conceptual framework
- Diale, Dineo, Kanakana-Katumba, Mukondeleli G, Maladzhi, Rendani W, von der Ohe, Hartmut
- Authors: Diale, Dineo , Kanakana-Katumba, Mukondeleli G , Maladzhi, Rendani W , von der Ohe, Hartmut
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/450592 , vital:74963 , xlink:href="https://ieomsociety.org/proceedings/2022nigeria/11.pdf"
- Description: Contextualizing technology and digitalization in a period of having to meet sustainable development goals (SDGs), requires a paradigm shift which calls for collaboration from multiple stakeholders. The current turbulent environment requires an investigation into ways of adopting the Fourth Industrial Revolution (4IR) as a pertinent mechanism for accelerating sustainable development goals. The need to formulate a conceptual framework and adapt it to the South African context, requires careful mapping of the elements of 4IR, the relevant infrastructure and resources There has been perceptions instigating resistance towards the SDGs, hence the need to develop the conceptual framework. The exploratory research method fitted well as its nature a systematic review to effect and respond to the abovementioned investigation. The study reviewed about 70 articles of which 53 of those were peerreviewed articles within 4th industrial revolution in South Africa as set for ecosystem. Due to limited research on the topic, possible impacting variables that added immeasurable value were explored as contributing factors the study. Both reviewed literature and government archive on 4th industrial revolution revealed how the ecosystems of 4IR accelerated the achievement of SDGs in South Africa. The study further singled smart factories, smart cities, integrated systems, green technologies, cybernetics, the internet of people, the internet of energy, and the internet of things as contributing factors towards 4IR. The recommended the applicability of the ecosystems onto the South African context to advance innovation agenda to achieve green energy, sustainable water provision, waste management, trade in low-carbon products, cleaner and greener technologies, green buildings, green chemistry and sustainable transport, as well as improved air quality.
- Full Text:
- Date Issued: 2022
- Authors: Diale, Dineo , Kanakana-Katumba, Mukondeleli G , Maladzhi, Rendani W , von der Ohe, Hartmut
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/450592 , vital:74963 , xlink:href="https://ieomsociety.org/proceedings/2022nigeria/11.pdf"
- Description: Contextualizing technology and digitalization in a period of having to meet sustainable development goals (SDGs), requires a paradigm shift which calls for collaboration from multiple stakeholders. The current turbulent environment requires an investigation into ways of adopting the Fourth Industrial Revolution (4IR) as a pertinent mechanism for accelerating sustainable development goals. The need to formulate a conceptual framework and adapt it to the South African context, requires careful mapping of the elements of 4IR, the relevant infrastructure and resources There has been perceptions instigating resistance towards the SDGs, hence the need to develop the conceptual framework. The exploratory research method fitted well as its nature a systematic review to effect and respond to the abovementioned investigation. The study reviewed about 70 articles of which 53 of those were peerreviewed articles within 4th industrial revolution in South Africa as set for ecosystem. Due to limited research on the topic, possible impacting variables that added immeasurable value were explored as contributing factors the study. Both reviewed literature and government archive on 4th industrial revolution revealed how the ecosystems of 4IR accelerated the achievement of SDGs in South Africa. The study further singled smart factories, smart cities, integrated systems, green technologies, cybernetics, the internet of people, the internet of energy, and the internet of things as contributing factors towards 4IR. The recommended the applicability of the ecosystems onto the South African context to advance innovation agenda to achieve green energy, sustainable water provision, waste management, trade in low-carbon products, cleaner and greener technologies, green buildings, green chemistry and sustainable transport, as well as improved air quality.
- Full Text:
- Date Issued: 2022
Electrocatalytic activity of benzothiazole substituted cobalt phthalocyanine in the presence of detonation nanodiamonds
- Ncwane, Lunathi, Mpeta, Lekhetho S, Nyokong, Tebello
- Authors: Ncwane, Lunathi , Mpeta, Lekhetho S , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295753 , vital:57375 , xlink:href="https://doi.org/10.1016/j.diamond.2022.109319"
- Description: This work reports on the synthesis and electrochemical sensing properties of benzothiazole substituted cobalt phthalocyanine (CoPc) when π-π stacked on detonation nanodiamonds (to form CoPc-DNDs(ππ). The synthesized materials were characterized using UV–visible, mass, Fourier transform infrared, and Raman spectroscopies as well as transmission electron microscopy and dynamic light scattering. The electrochemical studies were conducted using cyclic voltammetry, electrochemical impedance spectroscopy and chronoamperometry. Hydrazine was utilized as an analyte of interest, due to its mutagenic and carcinogenic effects. Glassy carbon electrodes (GCE) were modified with DNDs, CoPc, and CoPc-DNDs(ππ) represented as GCE/DNDs, GCE/CoPc and GCE/ CoPc-DNDs(ππ). GCE was also modified sequential addition of the CoPc and DNDs onto the GCE, represented as GCE/CoPc-DNDs(seq) when CoPc is placed before DNDs on the electrode and GCE/DNDs-CoPc(seq) when DNDs are placed before CoPc, where seq represents sequential. GCE/CoPc-DNDs(ππ) electrode gave better results in terms of limit of detection (1.68 μM), sensitivity (9.59 μA.mM−1) and catalytic rate constant (1.25 × 106 M−1 s−1).
- Full Text:
- Date Issued: 2022
- Authors: Ncwane, Lunathi , Mpeta, Lekhetho S , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295753 , vital:57375 , xlink:href="https://doi.org/10.1016/j.diamond.2022.109319"
- Description: This work reports on the synthesis and electrochemical sensing properties of benzothiazole substituted cobalt phthalocyanine (CoPc) when π-π stacked on detonation nanodiamonds (to form CoPc-DNDs(ππ). The synthesized materials were characterized using UV–visible, mass, Fourier transform infrared, and Raman spectroscopies as well as transmission electron microscopy and dynamic light scattering. The electrochemical studies were conducted using cyclic voltammetry, electrochemical impedance spectroscopy and chronoamperometry. Hydrazine was utilized as an analyte of interest, due to its mutagenic and carcinogenic effects. Glassy carbon electrodes (GCE) were modified with DNDs, CoPc, and CoPc-DNDs(ππ) represented as GCE/DNDs, GCE/CoPc and GCE/ CoPc-DNDs(ππ). GCE was also modified sequential addition of the CoPc and DNDs onto the GCE, represented as GCE/CoPc-DNDs(seq) when CoPc is placed before DNDs on the electrode and GCE/DNDs-CoPc(seq) when DNDs are placed before CoPc, where seq represents sequential. GCE/CoPc-DNDs(ππ) electrode gave better results in terms of limit of detection (1.68 μM), sensitivity (9.59 μA.mM−1) and catalytic rate constant (1.25 × 106 M−1 s−1).
- Full Text:
- Date Issued: 2022
Electrochemical detection of human epidermal growth factor receptor 2 using an aptamer on cobalt phthalocyanines–Cerium oxide nanoparticle conjugate
- Centane, Sixolile, Mgidlana, Sithi, Openda, Yolanda, Nyokong, Tebello
- Authors: Centane, Sixolile , Mgidlana, Sithi , Openda, Yolanda , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/299835 , vital:57859 , xlink:href="https://doi.org/10.1016/j.bioelechem.2022.108146"
- Description: The role of the biointerface design towards the development of an impedimetric biosensor for the electrochemical detection of human epidermal growth factor receptor 2 (HER2) is investigated. Two novel cobalt phthalocyanines: cobalt tetraphenyl acetic acid phthalocyanine and cobalt tetraphenyl propionic acid phthalocyanine are compared as signal amplifiers and immobilization platforms of the HB5 aptamer towards the electrochemical detection of HER2. In addition, the phthalocyanines are coupled with the metal based cerium oxide nanoparticles. The efficiency of each electrode modification step and the performance of the constructed aptasensors were assessed by impedance spectroscopy. The aptasensors showed very low limit of detection values (all less than 0.2 ng/mL) with high sensitivity and stability. Furthermore, the aptasensors showed very good performance even in human serum samples. Considering these results, the aptasensors demonstrate great potential for improved monitoring of human epidermal growth factor receptor 2 levels for the management of breast cancers.
- Full Text:
- Date Issued: 2022
- Authors: Centane, Sixolile , Mgidlana, Sithi , Openda, Yolanda , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/299835 , vital:57859 , xlink:href="https://doi.org/10.1016/j.bioelechem.2022.108146"
- Description: The role of the biointerface design towards the development of an impedimetric biosensor for the electrochemical detection of human epidermal growth factor receptor 2 (HER2) is investigated. Two novel cobalt phthalocyanines: cobalt tetraphenyl acetic acid phthalocyanine and cobalt tetraphenyl propionic acid phthalocyanine are compared as signal amplifiers and immobilization platforms of the HB5 aptamer towards the electrochemical detection of HER2. In addition, the phthalocyanines are coupled with the metal based cerium oxide nanoparticles. The efficiency of each electrode modification step and the performance of the constructed aptasensors were assessed by impedance spectroscopy. The aptasensors showed very low limit of detection values (all less than 0.2 ng/mL) with high sensitivity and stability. Furthermore, the aptasensors showed very good performance even in human serum samples. Considering these results, the aptasensors demonstrate great potential for improved monitoring of human epidermal growth factor receptor 2 levels for the management of breast cancers.
- Full Text:
- Date Issued: 2022
Enacting Environmental Ethics Education for Wildlife Conservation using an Afrophilic ‘Philosophy for Children’approach
- Authors: Bhurekeni, John
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/389821 , vital:68487 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/224689"
- Description: Environmental Ethics Education has in recent years emerged as a critical tool for wildlife conservation research. Despite this, Environmental Ethics Education is paradoxically predominated by traditional forms of western science such as the concept of the Anthropocene which appears to exclude aspects of African life-worlds where the natural environment is considered a heritage component and is linked to onto-ethical understandings of human existence. The purpose of this study is to explore how African heritage-based knowledges and practices are understood by children who identify and understand the relevance of their totems and taboos associated with them, in relation to wildlife conservation. The study from which this paper is derived utilised formative interventionist methodology complemented by a multi-voiced decolonial approach to explore whether children-participants aged 8 to 11 years understand the purposes of their totems and associated taboos. To achieve this I used an Afrophilic Philosophy for Children pedagogical approach, which foregrounds dialogical learning and development of critical reflexive thinking skills. Emerging findings indicated that children associated their totems and connected taboos as tools for protection against environmental pollution and for minimising resource over-extraction. Findings further demonstrated improved learner agency and development of ethical reasoning among children. As participants’ respect for environmental conservation and sustainability was informed by the significance placed on their totems, I recommend the need for schools to develop generative curricula that take seriously context-based solutions to environmental problems. Future research should also consider understanding environmental conservation issues from a context-based perspective, which can inform existing heritage practices and pedagogies.
- Full Text:
- Date Issued: 2022
- Authors: Bhurekeni, John
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/389821 , vital:68487 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/224689"
- Description: Environmental Ethics Education has in recent years emerged as a critical tool for wildlife conservation research. Despite this, Environmental Ethics Education is paradoxically predominated by traditional forms of western science such as the concept of the Anthropocene which appears to exclude aspects of African life-worlds where the natural environment is considered a heritage component and is linked to onto-ethical understandings of human existence. The purpose of this study is to explore how African heritage-based knowledges and practices are understood by children who identify and understand the relevance of their totems and taboos associated with them, in relation to wildlife conservation. The study from which this paper is derived utilised formative interventionist methodology complemented by a multi-voiced decolonial approach to explore whether children-participants aged 8 to 11 years understand the purposes of their totems and associated taboos. To achieve this I used an Afrophilic Philosophy for Children pedagogical approach, which foregrounds dialogical learning and development of critical reflexive thinking skills. Emerging findings indicated that children associated their totems and connected taboos as tools for protection against environmental pollution and for minimising resource over-extraction. Findings further demonstrated improved learner agency and development of ethical reasoning among children. As participants’ respect for environmental conservation and sustainability was informed by the significance placed on their totems, I recommend the need for schools to develop generative curricula that take seriously context-based solutions to environmental problems. Future research should also consider understanding environmental conservation issues from a context-based perspective, which can inform existing heritage practices and pedagogies.
- Full Text:
- Date Issued: 2022
Enhanced mitochondria destruction on MCF-7 and HeLa cell lines in vitro using triphenyl-phosphonium-labelled phthalocyanines in ultrasound-assisted photodynamic therapy activity
- Nene, Lindokuhle Cindy, Magadla, Aviwe, Nyokong, Tebello
- Authors: Nene, Lindokuhle Cindy , Magadla, Aviwe , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295766 , vital:57376 , xlink:href="https://doi.org/10.1016/j.jphotobiol.2022.112553"
- Description: This work reports on the reactive oxygen species (ROS) generation and the therapeutic activities of new triphenyl-phosphonium-labelled phthalocyanines (Pcs), the 2,9,16,23-tetrakis(N-(N-butyl-4-triphenyl-phosphonium)- pyridine-4-yloxy) Zn(II) Pc (3) and 2,9,16,23-tetrakis-(N-(N-butyl-4-triphenyl-phosphonium)-morpholino) Zn(II) Pc (4) upon exposure to light, ultrasound and the combination of light and ultrasound. Two types of ROS were detected: the singlet oxygen (1O2) and hydroxyl radicals. For light irradiations, only the 1O2 was detected. An increase in the ROS generation was observed for samples treated with the combination of light and ultrasound compared to the light and ultrasound mono-treatments. The in vitro anticancer activity through photodynamic (PDT) and sonodynamic (SDT) therapy for the Pcs were also determined and compared to the photo-sonodynamic combination therapy (PSDT). The two cancer cell lines used for the in vitro studies included the Michigan Cancer Foundation-7 (MCF-7) breast cancer and Henrietta Lacks (HeLa) cervical cancer cell lines. The SDT treatments showed improved therapeutic efficacy on the cancer cells for both the Pcs compared to PDT. PSDT showed better therapeutic efficacy compared to both the PDT and SDT mono-treatments.
- Full Text:
- Date Issued: 2022
- Authors: Nene, Lindokuhle Cindy , Magadla, Aviwe , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295766 , vital:57376 , xlink:href="https://doi.org/10.1016/j.jphotobiol.2022.112553"
- Description: This work reports on the reactive oxygen species (ROS) generation and the therapeutic activities of new triphenyl-phosphonium-labelled phthalocyanines (Pcs), the 2,9,16,23-tetrakis(N-(N-butyl-4-triphenyl-phosphonium)- pyridine-4-yloxy) Zn(II) Pc (3) and 2,9,16,23-tetrakis-(N-(N-butyl-4-triphenyl-phosphonium)-morpholino) Zn(II) Pc (4) upon exposure to light, ultrasound and the combination of light and ultrasound. Two types of ROS were detected: the singlet oxygen (1O2) and hydroxyl radicals. For light irradiations, only the 1O2 was detected. An increase in the ROS generation was observed for samples treated with the combination of light and ultrasound compared to the light and ultrasound mono-treatments. The in vitro anticancer activity through photodynamic (PDT) and sonodynamic (SDT) therapy for the Pcs were also determined and compared to the photo-sonodynamic combination therapy (PSDT). The two cancer cell lines used for the in vitro studies included the Michigan Cancer Foundation-7 (MCF-7) breast cancer and Henrietta Lacks (HeLa) cervical cancer cell lines. The SDT treatments showed improved therapeutic efficacy on the cancer cells for both the Pcs compared to PDT. PSDT showed better therapeutic efficacy compared to both the PDT and SDT mono-treatments.
- Full Text:
- Date Issued: 2022
Enhanced Solar Efficiency via Incorporation of Plasmonic Gold Nanostructures in a Titanium Oxide/Eosin Y Dye-Sensitized Solar Cell
- Nyembe, Sanele, Chindeka, Francis, Ndlovu, Gebhu, Mkhohlakali, Andile, Nyokong, Tebello, Sikhwiyhilu, Lucy
- Authors: Nyembe, Sanele , Chindeka, Francis , Ndlovu, Gebhu , Mkhohlakali, Andile , Nyokong, Tebello , Sikhwiyhilu, Lucy
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295783 , vital:57377 , xlink:href="https://doi.org/10.3390/nano12101715"
- Description: Plasmonic gold nanoparticles significantly improved the efficiency of a TiO2 and Eosin Y based dye-sensitized solar cell from 2.4 to 6.43%. The gold nanoparticles’ sizes that were tested were 14 nm, 30 nm and 40 nm synthesized via the systematic reduction of citrate concentration using the Turkevich method. Prestine TiO2 without plasmonic gold nanoparticles yielded an efficiency of 2.4%. However, the loading of 40 nm gold nanoparticles into the TiO2 matrix yielded the highest DSSC efficiency of 6.43% compared to 30 nm (5.91%) and 14 nm (2.6%). The relatively high efficiency demonstrated by plasmonic gold nanoparticles is ascribed to light absorption/scattering, hot electron injection and plasmon-induced resonance energy transfer (PIRET), influenced by the size of the gold nanoparticles.
- Full Text:
- Date Issued: 2022
- Authors: Nyembe, Sanele , Chindeka, Francis , Ndlovu, Gebhu , Mkhohlakali, Andile , Nyokong, Tebello , Sikhwiyhilu, Lucy
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295783 , vital:57377 , xlink:href="https://doi.org/10.3390/nano12101715"
- Description: Plasmonic gold nanoparticles significantly improved the efficiency of a TiO2 and Eosin Y based dye-sensitized solar cell from 2.4 to 6.43%. The gold nanoparticles’ sizes that were tested were 14 nm, 30 nm and 40 nm synthesized via the systematic reduction of citrate concentration using the Turkevich method. Prestine TiO2 without plasmonic gold nanoparticles yielded an efficiency of 2.4%. However, the loading of 40 nm gold nanoparticles into the TiO2 matrix yielded the highest DSSC efficiency of 6.43% compared to 30 nm (5.91%) and 14 nm (2.6%). The relatively high efficiency demonstrated by plasmonic gold nanoparticles is ascribed to light absorption/scattering, hot electron injection and plasmon-induced resonance energy transfer (PIRET), influenced by the size of the gold nanoparticles.
- Full Text:
- Date Issued: 2022
Evaluation of functionalized silver and silica nanoparticles for the removal of deoxyribonucleic acid conveying antibiotics resistance genes from water
- Authors: Ezeuko, Adaora Stella
- Date: 2022
- Subjects: DNA , Silica , Water
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/27765 , vital:69414
- Description: Antibiotic resistance genes ARGs are recognized as a serious public health emergency linked to extensive use of antibiotics by humans and animals as a prophylactic agent that treats and prevents infections. The occurrence of high concentrations being identified in wastewater treatment plants, rivers, etc is due to untreated effluents being discharged from households, hospitals, agriculture, and pharmaceutical industries. The application of adequate treatment techniques and material for the removal of bacteria DNA conveying ARGs from the effluents before their release to the environment cannot be overemphasized. Adsorption techniques seem to be effective due to their easy design, operation, and ability to regenerate adsorbents for use without producing toxic by-products. This concept was employed for the removal of bacteria DNA conveying ARGs from simulated aqueous solution, effluents from hospital, river and WWTPs using silver and silica metallic nanoparticles. This thesis investigated the effectiveness of metallic nanoparticles containing silver AgNPs and mesoporous silica nanoparticles MSNPs as well as magnetite Fe3O4 functionalized with 4 4hydroxyphenyl 2 262-terpyridine onto their surface, for the removal of bacteria DNA conveying antibiotic resistance genes from water samples from hospitals, river, and wastewater treatment plants WWTPs. Silver nanoparticles AgNPs of different molar concentrations 0.1M, 0.5M and 1.0 M and mesoporous silica nanoparticles MSNPs adsorbents were successfully synthesized in their original states and surface functionalization achieved by incorporating magnetite Fe3O4 and 4 4 hydroxyphenyl 2 2 6 2 terpyridine on the silver AgNPs Fe3O4 and silica MSNPs TPPY surfaces respectively. Their effectiveness as adsorbent for the removal of bacteria DNA conveying ARGs from aqueous solutions and real water/wastewater samples were investigated. The DNA uptake by the as-synthesized AgNPs and MSNPs were compared to the functionalized AgNPs Fe3O4 and MSNPsTPPY by determining the adsorbents with the highest removal efficiencies. All as synthesized and functionalized adsorbents were characterized by SEM, EDX, FTIR, XRD, UV spectroscopy and PZC before the removal process. The extraction of genomic DNA from antibiotic-resistant Enterococcus faecium and Vibrio parahaemolyticus was successfully achieved via the boiling method. Antibiotic susceptibility test was conducted using the disk diffusion method before the commencement of genomic DNA extraction. Molecular characterization via gel electrophoresis confirmed the presence of resistance genes at different base pairs. Adsorption batch experiment were investigated, and the best optimum parameters were evaluated through the influence of pH, contact time, initial DNA concentration, adsorbent dose, and competitive ions for each sorption process. The rate determining step were determined by fitting kinetic models such as Natarajan and Khalaf first order, pseudo first order, pseudo second order, Elovich model to experimental data. Also, the adsorption mechanisms determining adsorption equilibrium were investigated by fitting Freundlich, Langmuir and Sips model into the experimental data. The application of AgNPsFe3O4 nanocomposite and MSNPsTPPY for the removal of bacteria DNA demonstrated much enhancement for DNA uptake than the as-synthesized AgNPs and MSNPs materials. The incorporation of magnetite and 4 4hydroxyphenyl 2 2 6 2-terpyridine onto AgNPs and MSNPs significantly enhanced the binding affinity towards the removal the bacteria DNA via strong electrostatic attraction between the active sites on the adsorbent and the negative DNA molecules. Finally, high adsorption capacities were recorded with AgNPsFe3O4 nanocomposite and MSNPsTPPY compared to AgNPs and MSNPs with chaotropic salts. The kinetic adsorption models were mostly best fitted by the pseudo-second order and Elovich models while the adsorption equilibrium was best described by Langmuir and Sips isotherm models. MSNPs with different chaotropic salts, AgNPsFe3O4 nanocomposite and MSNPsTPPY also proved its effectiveness in DNA removal not only in the simulated aqueous solution but in three different real life water samples obtained from Cofimvaba hospital, Ndevana river and Uitenhage WWTPs. High adsorption efficiencies above 90 percent were achieved during the removal of DNA in all the three real water samples. Therefore, application of these adsorbents for the removal of bacteria DNA conveying ARGs may be a promising option that would tackle the consequences of consuming ARGs infected water globally. , Thesis (MSc) -- Faculty of Science and Agriculture, 2022
- Full Text:
- Date Issued: 2022
- Authors: Ezeuko, Adaora Stella
- Date: 2022
- Subjects: DNA , Silica , Water
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/27765 , vital:69414
- Description: Antibiotic resistance genes ARGs are recognized as a serious public health emergency linked to extensive use of antibiotics by humans and animals as a prophylactic agent that treats and prevents infections. The occurrence of high concentrations being identified in wastewater treatment plants, rivers, etc is due to untreated effluents being discharged from households, hospitals, agriculture, and pharmaceutical industries. The application of adequate treatment techniques and material for the removal of bacteria DNA conveying ARGs from the effluents before their release to the environment cannot be overemphasized. Adsorption techniques seem to be effective due to their easy design, operation, and ability to regenerate adsorbents for use without producing toxic by-products. This concept was employed for the removal of bacteria DNA conveying ARGs from simulated aqueous solution, effluents from hospital, river and WWTPs using silver and silica metallic nanoparticles. This thesis investigated the effectiveness of metallic nanoparticles containing silver AgNPs and mesoporous silica nanoparticles MSNPs as well as magnetite Fe3O4 functionalized with 4 4hydroxyphenyl 2 262-terpyridine onto their surface, for the removal of bacteria DNA conveying antibiotic resistance genes from water samples from hospitals, river, and wastewater treatment plants WWTPs. Silver nanoparticles AgNPs of different molar concentrations 0.1M, 0.5M and 1.0 M and mesoporous silica nanoparticles MSNPs adsorbents were successfully synthesized in their original states and surface functionalization achieved by incorporating magnetite Fe3O4 and 4 4 hydroxyphenyl 2 2 6 2 terpyridine on the silver AgNPs Fe3O4 and silica MSNPs TPPY surfaces respectively. Their effectiveness as adsorbent for the removal of bacteria DNA conveying ARGs from aqueous solutions and real water/wastewater samples were investigated. The DNA uptake by the as-synthesized AgNPs and MSNPs were compared to the functionalized AgNPs Fe3O4 and MSNPsTPPY by determining the adsorbents with the highest removal efficiencies. All as synthesized and functionalized adsorbents were characterized by SEM, EDX, FTIR, XRD, UV spectroscopy and PZC before the removal process. The extraction of genomic DNA from antibiotic-resistant Enterococcus faecium and Vibrio parahaemolyticus was successfully achieved via the boiling method. Antibiotic susceptibility test was conducted using the disk diffusion method before the commencement of genomic DNA extraction. Molecular characterization via gel electrophoresis confirmed the presence of resistance genes at different base pairs. Adsorption batch experiment were investigated, and the best optimum parameters were evaluated through the influence of pH, contact time, initial DNA concentration, adsorbent dose, and competitive ions for each sorption process. The rate determining step were determined by fitting kinetic models such as Natarajan and Khalaf first order, pseudo first order, pseudo second order, Elovich model to experimental data. Also, the adsorption mechanisms determining adsorption equilibrium were investigated by fitting Freundlich, Langmuir and Sips model into the experimental data. The application of AgNPsFe3O4 nanocomposite and MSNPsTPPY for the removal of bacteria DNA demonstrated much enhancement for DNA uptake than the as-synthesized AgNPs and MSNPs materials. The incorporation of magnetite and 4 4hydroxyphenyl 2 2 6 2-terpyridine onto AgNPs and MSNPs significantly enhanced the binding affinity towards the removal the bacteria DNA via strong electrostatic attraction between the active sites on the adsorbent and the negative DNA molecules. Finally, high adsorption capacities were recorded with AgNPsFe3O4 nanocomposite and MSNPsTPPY compared to AgNPs and MSNPs with chaotropic salts. The kinetic adsorption models were mostly best fitted by the pseudo-second order and Elovich models while the adsorption equilibrium was best described by Langmuir and Sips isotherm models. MSNPs with different chaotropic salts, AgNPsFe3O4 nanocomposite and MSNPsTPPY also proved its effectiveness in DNA removal not only in the simulated aqueous solution but in three different real life water samples obtained from Cofimvaba hospital, Ndevana river and Uitenhage WWTPs. High adsorption efficiencies above 90 percent were achieved during the removal of DNA in all the three real water samples. Therefore, application of these adsorbents for the removal of bacteria DNA conveying ARGs may be a promising option that would tackle the consequences of consuming ARGs infected water globally. , Thesis (MSc) -- Faculty of Science and Agriculture, 2022
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- Date Issued: 2022
Evaluation of the extent of the public programming by Eastern Cape Provincial Archives and Records Services
- Tshebi, Siyathemba Mboneleli https://orcid.org/0000-0003-2833-9842
- Authors: Tshebi, Siyathemba Mboneleli https://orcid.org/0000-0003-2833-9842
- Date: 2022
- Subjects: Grahamstown (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/27663 , vital:69381
- Description: Public programming initiatives are an integral part of archival operations worldwide as they support the greater use of archival records by attracting prospective users and sponsors. Public programming comprises a sequence of strategies for publicizing and marketing archives to the public, which are crucial in archival operations as they promote better use of archives and records. South African National Archives and Records. Services depends on provisions of the National Archives of South Africa Act of 1996 in its strive to promote access and use of archives as sources of information. . unknown and therefore not used to their maximal utility value, likely due to low-key and ineffective archival public programming initiatives. Consequently, the primary purpose of this research study was to evaluate the extent of public programming strategies used by the Eastern Cape Provincial Archives and Records Services (EAPARS). The study used a mixed-method, embracing qualitative and quantitative research approaches. As an integrated record-keeping framework, Record Continuum was used as a theoretical framework to guide the study. Sixteen copies of questionnaire were distributed among staff and users ECPARS. The research uncovered that ECPARS does not have specific regulations and policies on public programming, but relies on the more general provisions of the Provincial Archives and Records Services Act of 1996 as a guiding instrument in executing its public programming operations. The study further revealed various factors, such as the limited budget and inadequate staff, as key hindering factors in the smooth execution of archival public programming plans by ECPARS. The study recommends a review and update by ECPARS of how it can specifically effectively implement the provisions of the 1996 Act to the modern ways of taking public archives to the people. The research also recommends that ECPARS engage additional staff or outsourced services to strengthen its the public programming of its archival resources and services workforce for Eastern Cape Provincial Archives and Records. The study concludes that improved financial resources, use of ICTs, and coherent policy framework, and public awareness creation and education can facilitate better to acquire, widen access to use of its archives. Keyword , Thesis (MLIS) -- Faculty of Social Sciences and Humanities, 2022
- Full Text:
- Date Issued: 2022
- Authors: Tshebi, Siyathemba Mboneleli https://orcid.org/0000-0003-2833-9842
- Date: 2022
- Subjects: Grahamstown (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/27663 , vital:69381
- Description: Public programming initiatives are an integral part of archival operations worldwide as they support the greater use of archival records by attracting prospective users and sponsors. Public programming comprises a sequence of strategies for publicizing and marketing archives to the public, which are crucial in archival operations as they promote better use of archives and records. South African National Archives and Records. Services depends on provisions of the National Archives of South Africa Act of 1996 in its strive to promote access and use of archives as sources of information. . unknown and therefore not used to their maximal utility value, likely due to low-key and ineffective archival public programming initiatives. Consequently, the primary purpose of this research study was to evaluate the extent of public programming strategies used by the Eastern Cape Provincial Archives and Records Services (EAPARS). The study used a mixed-method, embracing qualitative and quantitative research approaches. As an integrated record-keeping framework, Record Continuum was used as a theoretical framework to guide the study. Sixteen copies of questionnaire were distributed among staff and users ECPARS. The research uncovered that ECPARS does not have specific regulations and policies on public programming, but relies on the more general provisions of the Provincial Archives and Records Services Act of 1996 as a guiding instrument in executing its public programming operations. The study further revealed various factors, such as the limited budget and inadequate staff, as key hindering factors in the smooth execution of archival public programming plans by ECPARS. The study recommends a review and update by ECPARS of how it can specifically effectively implement the provisions of the 1996 Act to the modern ways of taking public archives to the people. The research also recommends that ECPARS engage additional staff or outsourced services to strengthen its the public programming of its archival resources and services workforce for Eastern Cape Provincial Archives and Records. The study concludes that improved financial resources, use of ICTs, and coherent policy framework, and public awareness creation and education can facilitate better to acquire, widen access to use of its archives. Keyword , Thesis (MLIS) -- Faculty of Social Sciences and Humanities, 2022
- Full Text:
- Date Issued: 2022
Expansive Learning and Transformative Agency for Equity and Sustainability: Formative Interventions in Six Continents
- Engeström, Yrjö, Bal, Aydin, Sannino, Annalisa, Morgado, Luciana P, de Gouveia Vilela, R A, Querol, Marco P, Lotz-Sisitka, Heila, Wei, Ge, Chikunda, Charles, Hopwood, Nick, Virkkunen, Jaakko, Mukute, Mutizwa
- Authors: Engeström, Yrjö , Bal, Aydin , Sannino, Annalisa , Morgado, Luciana P , de Gouveia Vilela, R A , Querol, Marco P , Lotz-Sisitka, Heila , Wei, Ge , Chikunda, Charles , Hopwood, Nick , Virkkunen, Jaakko , Mukute, Mutizwa
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , symposium
- Identifier: http://hdl.handle.net/10962/436688 , vital:73293 , ISBN 978-3-030-99347-4 , https://repository.isls.org//handle/1/8974
- Description: This double symposium brings together activity-theoretical formative intervention research conducted in six continents. The aim is to illuminate and examine the common threads, important differences, and new challenges of formative inter-vention studies to address “wicked problems” in different cul-tural, political, and economic contexts. Formative interven-tions facilitate expansive learning and systemic transfor-mation led by local stakeholders in organizations and social movements. The formative intervention methodology is based on the principles of double stimulation and ascending from the abstract to the concrete. Its most well-known appli-cation is the Change Laboratory method. Formative interven-tions generate and support expansive learning and trans-formative agency. The current global crises of climate change, poverty and deepening inequalities are giving rise to what is called fourth generation activity theory for tackling fateful challenges by building heterogenous multiactivity coa-litions. The symposium will present the theoretical and peda-gogical challenges and possibilities in Change Laboratories and other formative interventions to develop just and sus-tainable solutions to global crises.
- Full Text:
- Date Issued: 2022
- Authors: Engeström, Yrjö , Bal, Aydin , Sannino, Annalisa , Morgado, Luciana P , de Gouveia Vilela, R A , Querol, Marco P , Lotz-Sisitka, Heila , Wei, Ge , Chikunda, Charles , Hopwood, Nick , Virkkunen, Jaakko , Mukute, Mutizwa
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , symposium
- Identifier: http://hdl.handle.net/10962/436688 , vital:73293 , ISBN 978-3-030-99347-4 , https://repository.isls.org//handle/1/8974
- Description: This double symposium brings together activity-theoretical formative intervention research conducted in six continents. The aim is to illuminate and examine the common threads, important differences, and new challenges of formative inter-vention studies to address “wicked problems” in different cul-tural, political, and economic contexts. Formative interven-tions facilitate expansive learning and systemic transfor-mation led by local stakeholders in organizations and social movements. The formative intervention methodology is based on the principles of double stimulation and ascending from the abstract to the concrete. Its most well-known appli-cation is the Change Laboratory method. Formative interven-tions generate and support expansive learning and trans-formative agency. The current global crises of climate change, poverty and deepening inequalities are giving rise to what is called fourth generation activity theory for tackling fateful challenges by building heterogenous multiactivity coa-litions. The symposium will present the theoretical and peda-gogical challenges and possibilities in Change Laboratories and other formative interventions to develop just and sus-tainable solutions to global crises.
- Full Text:
- Date Issued: 2022