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
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
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, 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 , 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 , 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
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
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
Fabrication of asymmetrical morpholine phthalocyanines conjugated chitosan-polyacrylonitrile nanofibers for improved photodynamic antimicrobial chemotherapy activity
- Sindelo, Azole, Mafukidze, Donovan M, Nyokong, Tebello
- Authors: Sindelo, Azole , Mafukidze, Donovan M , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229873 , vital:49719 , xlink:href="https://doi.org/10.1016/j.pdpdt.2022.102760"
- Description: The work is based on the synthesis and photodynamic antimicrobial chemotherapy (PACT) activities of neutral (1 and 2) and cationic (1Q and 2Q) morpholine substituted phthalocyanines. For applicability, these complexes were covalently linked to modified polyacrylonitrile (PAN) to form 1-PAN, 2-PAN, 1Q-PAN, and 2Q-PAN, respectively. Chitosan was conjugated to PAN (to form PAN-CS) which was then linked to the Pcs to form PAN-CS-1, PAN-CS-2, PAN-CS-1Q, and PAN-CS-2Q, respectively. Singlet oxygen quantum yields improved following the inclusion of chitosan. The PACT activities of the complexes alone and when anchored to both PAN and PAN-CS was evaluated against bacteria: S. aureus, E. coli and fungi C. albicans. Cationic phthalocyanine showed high efficacy values of >7 log reduction value for all microorganisms. These results translated into excellent bacterial colony reduction of >90% against both S. aureus and C. albicans after 1 h of photoirradiation on PAN-CS support.
- Full Text:
- Date Issued: 2022
- Authors: Sindelo, Azole , Mafukidze, Donovan M , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229873 , vital:49719 , xlink:href="https://doi.org/10.1016/j.pdpdt.2022.102760"
- Description: The work is based on the synthesis and photodynamic antimicrobial chemotherapy (PACT) activities of neutral (1 and 2) and cationic (1Q and 2Q) morpholine substituted phthalocyanines. For applicability, these complexes were covalently linked to modified polyacrylonitrile (PAN) to form 1-PAN, 2-PAN, 1Q-PAN, and 2Q-PAN, respectively. Chitosan was conjugated to PAN (to form PAN-CS) which was then linked to the Pcs to form PAN-CS-1, PAN-CS-2, PAN-CS-1Q, and PAN-CS-2Q, respectively. Singlet oxygen quantum yields improved following the inclusion of chitosan. The PACT activities of the complexes alone and when anchored to both PAN and PAN-CS was evaluated against bacteria: S. aureus, E. coli and fungi C. albicans. Cationic phthalocyanine showed high efficacy values of >7 log reduction value for all microorganisms. These results translated into excellent bacterial colony reduction of >90% against both S. aureus and C. albicans after 1 h of photoirradiation on PAN-CS support.
- Full Text:
- Date Issued: 2022
From affirmative to transformative approaches to academic development
- McKenna, Sioux, Hlengwa, Amanda, Quinn, Lyn, Vorster, Jo-Anne
- Authors: McKenna, Sioux , Hlengwa, Amanda , Quinn, Lyn , Vorster, Jo-Anne
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426651 , vital:72375 , xlink:href="https://doi.org/10.1080/13562517.2022.2119077"
- Description: Much academic development work, whether it be student, academic staff, institutional or curriculum development, is undertaken from an affirmative rather than a transformative approach (Luckett, L., and S. Shay. 2020.“Reframing the Curriculum: A Transformative Approach.” Critical Studies in Education61 (1): 50–65). To be transformative, academic development has to reframe the problem beyond one of poor student retention and throughput. We need to make sense of the conditions from which issues such as poor retention and throughput rates emerge, rather than focusing on mitigating the effects of such conditions within the status quo. Drawing on Fraser’s concept of parity of participation, we suggest that if academic development is to engage in transformative approaches, it needs to adjust the scale of the problem and challenge underpinning assumptions, and thereby review the fitness of universities, curricula and academic development practices for a pluralist society. In sum, a transformative approach to academic development work will entail conceptualising academic development as a political knowledge project.
- Full Text:
- Date Issued: 2022
- Authors: McKenna, Sioux , Hlengwa, Amanda , Quinn, Lyn , Vorster, Jo-Anne
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426651 , vital:72375 , xlink:href="https://doi.org/10.1080/13562517.2022.2119077"
- Description: Much academic development work, whether it be student, academic staff, institutional or curriculum development, is undertaken from an affirmative rather than a transformative approach (Luckett, L., and S. Shay. 2020.“Reframing the Curriculum: A Transformative Approach.” Critical Studies in Education61 (1): 50–65). To be transformative, academic development has to reframe the problem beyond one of poor student retention and throughput. We need to make sense of the conditions from which issues such as poor retention and throughput rates emerge, rather than focusing on mitigating the effects of such conditions within the status quo. Drawing on Fraser’s concept of parity of participation, we suggest that if academic development is to engage in transformative approaches, it needs to adjust the scale of the problem and challenge underpinning assumptions, and thereby review the fitness of universities, curricula and academic development practices for a pluralist society. In sum, a transformative approach to academic development work will entail conceptualising academic development as a political knowledge project.
- Full Text:
- Date Issued: 2022
From imperialism to radical hospitality: propositions for reconfiguring social work towards a justice-to-come
- Bozalek, Vivienne, Holscher, Dorothee
- Authors: Bozalek, Vivienne , Holscher, Dorothee
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426904 , vital:72399 , xlink:href="https://doi.org/10.25159/2708-9355/8889"
- Description: The focus of the article is on injustices towards South African families in postcolonial and neocolonial contexts, our understanding of which has been greatly enlarged by Nancy Fraser’s conceptualisations of expropriation and imperialism and Jacques Derrida’s notions of hostility and hospitality. We used Walter Benjamin’s and Karen Barad’s montage methods of fragmentary writing to diffractively read expropriation, imperialism, hostility and hospitality through one another in the context of injustices done to South African families. A diffractive methodology entails a close and attentive reading of concepts or pieces of text through one another, to arrive at new insights with regard to a particular issue. The new insights we arrive at in the article are five propositions for ethically engaging in a justice-to-come for social work – that of attentiveness, rendering each other capable, responsibility, response-ability and radical hospitality.
- Full Text:
- Date Issued: 2022
- Authors: Bozalek, Vivienne , Holscher, Dorothee
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426904 , vital:72399 , xlink:href="https://doi.org/10.25159/2708-9355/8889"
- Description: The focus of the article is on injustices towards South African families in postcolonial and neocolonial contexts, our understanding of which has been greatly enlarged by Nancy Fraser’s conceptualisations of expropriation and imperialism and Jacques Derrida’s notions of hostility and hospitality. We used Walter Benjamin’s and Karen Barad’s montage methods of fragmentary writing to diffractively read expropriation, imperialism, hostility and hospitality through one another in the context of injustices done to South African families. A diffractive methodology entails a close and attentive reading of concepts or pieces of text through one another, to arrive at new insights with regard to a particular issue. The new insights we arrive at in the article are five propositions for ethically engaging in a justice-to-come for social work – that of attentiveness, rendering each other capable, responsibility, response-ability and radical hospitality.
- Full Text:
- Date Issued: 2022
Fuelwood in South Africa Revisited: Widespread Use in a Policy Vacuum
- Shackleton, Charlie M, Sinasson, Gisele, Adeyemi, Opeyemi, Martins, Vusumzi
- Authors: Shackleton, Charlie M , Sinasson, Gisele , Adeyemi, Opeyemi , Martins, Vusumzi
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/402275 , vital:69837 , xlink:href="https://doi.org/10.3390/su141711018"
- Description: South Africa has experienced massive urbanisation and socioeconomic development over the past two decades. Concomitantly, the national energy policy focuses on the provision of modern fuels, notably electricity, for domestic use. Given this policy environment and socioeconomic development, we examine pertinent literature and policies from South Africa on fuelwood use, value, and sustainability to understand how it might have changed in tandem with the national shifts in urbanisation and socioeconomic development over the last 20 years. Recent literature shows that fuelwood is still used to some extent by 96% of rural households and 69% of low-income urban ones. We also estimate that the use of fuelwood by rural households alone is valued at approximately ZAR 10.5 billion (approx. USD 700 million) annually, with the probability of an equally high value to low-income urban households. However, despite the extensive use and high value, our analysis of cognate national policies related to energy, forestry, environment, and social development, show that fuelwood and its use is hardly considered, indicating a policy vacuum. This policy vacuum means that there is no strategic or apposite support or interventions in any localised areas where fuelwood demand might exceed supply, thereby undermining the livelihoods and energy security of affected citizens, most notably the poor.
- Full Text:
- Date Issued: 2022
- Authors: Shackleton, Charlie M , Sinasson, Gisele , Adeyemi, Opeyemi , Martins, Vusumzi
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/402275 , vital:69837 , xlink:href="https://doi.org/10.3390/su141711018"
- Description: South Africa has experienced massive urbanisation and socioeconomic development over the past two decades. Concomitantly, the national energy policy focuses on the provision of modern fuels, notably electricity, for domestic use. Given this policy environment and socioeconomic development, we examine pertinent literature and policies from South Africa on fuelwood use, value, and sustainability to understand how it might have changed in tandem with the national shifts in urbanisation and socioeconomic development over the last 20 years. Recent literature shows that fuelwood is still used to some extent by 96% of rural households and 69% of low-income urban ones. We also estimate that the use of fuelwood by rural households alone is valued at approximately ZAR 10.5 billion (approx. USD 700 million) annually, with the probability of an equally high value to low-income urban households. However, despite the extensive use and high value, our analysis of cognate national policies related to energy, forestry, environment, and social development, show that fuelwood and its use is hardly considered, indicating a policy vacuum. This policy vacuum means that there is no strategic or apposite support or interventions in any localised areas where fuelwood demand might exceed supply, thereby undermining the livelihoods and energy security of affected citizens, most notably the poor.
- Full Text:
- Date Issued: 2022
Fuelwood Production and Carbon Sequestration in Public Urban Green Spaces in Bulawayo, Zimbabwe
- Ngulani, Thembelihle, Shackleton, Charlie M
- Authors: Ngulani, Thembelihle , Shackleton, Charlie M
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/438757 , vital:73497 , xlink:href="https://doi.org/10.3390/f13050741"
- Description: Understanding tree species autecology and population structure supports effective conservation actions. Of particular importance are multipurpose trees that provide non-timber forest products (NTFPs). We assessed the population structures and morphologies of two species of NTFP trees in the genus Mimusops across bioclimatic zones in Benin by sampling 288 plots within 11 forests. Structural characteristics were compared between species, forests and zones. Correlations were also observed between Mimusops tree regeneration density, tree features and ecological characteristics. The density of trees ≥5 cm and of regeneration and mean tree height were higher for M. andongensis (within more protected forest) than M. kummel (in forests with access to people), while the highest mean diameter was observed for M. kummel. Tree and regeneration densities and mean height were greatest in the humid zone of Benin, whilst the largest mean diameter was obtained in the sub-humid zone. The results showed significant correlations between regeneration density and soil properties for M. andongensis but not for M. kummel. The correlations between tree morphology and soil characteristics were weak for both species. Ecological characteristics, along with the species’ functional traits and pressures, are important factors related to the observed differences between the species. All diameter classes were represented, and the population seemed more stable in the more protected forest relative to other forests. Mimusops trees with a diameter of 5–15 cm represented more than 30% of this species in most forests; this suggests, for M. kummel, whose trees flower when quite small (≥6 cm dbh), that there are sufficient reproductive trees. Thus, as a long-lived species, its populations could be maintained even with low/episodic recruitment. However, we found no regeneration in many forests and climate change could threaten populations. Therefore, it is important to investigate regeneration growth and dynamics, seed production and germination of the species in relation to the biophysical conditions and disturbances experienced by Mimusops stands.
- Full Text:
- Date Issued: 2022
- Authors: Ngulani, Thembelihle , Shackleton, Charlie M
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/438757 , vital:73497 , xlink:href="https://doi.org/10.3390/f13050741"
- Description: Understanding tree species autecology and population structure supports effective conservation actions. Of particular importance are multipurpose trees that provide non-timber forest products (NTFPs). We assessed the population structures and morphologies of two species of NTFP trees in the genus Mimusops across bioclimatic zones in Benin by sampling 288 plots within 11 forests. Structural characteristics were compared between species, forests and zones. Correlations were also observed between Mimusops tree regeneration density, tree features and ecological characteristics. The density of trees ≥5 cm and of regeneration and mean tree height were higher for M. andongensis (within more protected forest) than M. kummel (in forests with access to people), while the highest mean diameter was observed for M. kummel. Tree and regeneration densities and mean height were greatest in the humid zone of Benin, whilst the largest mean diameter was obtained in the sub-humid zone. The results showed significant correlations between regeneration density and soil properties for M. andongensis but not for M. kummel. The correlations between tree morphology and soil characteristics were weak for both species. Ecological characteristics, along with the species’ functional traits and pressures, are important factors related to the observed differences between the species. All diameter classes were represented, and the population seemed more stable in the more protected forest relative to other forests. Mimusops trees with a diameter of 5–15 cm represented more than 30% of this species in most forests; this suggests, for M. kummel, whose trees flower when quite small (≥6 cm dbh), that there are sufficient reproductive trees. Thus, as a long-lived species, its populations could be maintained even with low/episodic recruitment. However, we found no regeneration in many forests and climate change could threaten populations. Therefore, it is important to investigate regeneration growth and dynamics, seed production and germination of the species in relation to the biophysical conditions and disturbances experienced by Mimusops stands.
- Full Text:
- Date Issued: 2022
Ga III triarylcorroles with push–pull substitutions
- Niu, Yingjie, Wang, Lin, Guo, Yingxin, Zhu, Weihua, Soy, Rodah C, Babu, Balaji, Mack, John, Nyokong, Tebello, Xu, Haijun, Liang, Xu
- Authors: Niu, Yingjie , Wang, Lin , Guo, Yingxin , Zhu, Weihua , Soy, Rodah C , Babu, Balaji , Mack, John , Nyokong, Tebello , Xu, Haijun , Liang, Xu
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300079 , vital:57890 , xlink:href="https://doi.org/10.1039/D2DT01262F"
- Description: Two A2B type H3corroles and two GaIIItriarylcorroles with carbazole substitutions at 10-positions were synthesized and characterized. An analysis of structure–property relationships of the corroles has been carried out by investigating the optical spectroscopy of the dyes to trends predicted in DFT and TD-DFT calculations. Interestingly, the photodynamic therapy (PDT) and photodynamic antimicrobial chemotherapy (PACT) activity properties of the GaIIItriarylcorroles were determined against the MCF-7 breast cancer line, and Staphyloccocus aureus (S. aureus) and Escherichia coli (E. coli), respectively. The cationic G-2Q species exhibited the most favorable properties with an IC50 value of 7.8 μM against MCF-7 cells, and Log reduction values of 7.78 and 3.26 against planktonic S. aureus and E. coli at 0.5 and 10 μM, respectively.
- Full Text:
- Date Issued: 2022
- Authors: Niu, Yingjie , Wang, Lin , Guo, Yingxin , Zhu, Weihua , Soy, Rodah C , Babu, Balaji , Mack, John , Nyokong, Tebello , Xu, Haijun , Liang, Xu
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300079 , vital:57890 , xlink:href="https://doi.org/10.1039/D2DT01262F"
- Description: Two A2B type H3corroles and two GaIIItriarylcorroles with carbazole substitutions at 10-positions were synthesized and characterized. An analysis of structure–property relationships of the corroles has been carried out by investigating the optical spectroscopy of the dyes to trends predicted in DFT and TD-DFT calculations. Interestingly, the photodynamic therapy (PDT) and photodynamic antimicrobial chemotherapy (PACT) activity properties of the GaIIItriarylcorroles were determined against the MCF-7 breast cancer line, and Staphyloccocus aureus (S. aureus) and Escherichia coli (E. coli), respectively. The cationic G-2Q species exhibited the most favorable properties with an IC50 value of 7.8 μM against MCF-7 cells, and Log reduction values of 7.78 and 3.26 against planktonic S. aureus and E. coli at 0.5 and 10 μM, respectively.
- Full Text:
- Date Issued: 2022
Household dietary patterns and food security challenges in Peri-Urban South Africa: A reflection of high unemployment in the wake of rising food prices
- Authors: Chakona, Gamuchirai
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433943 , vital:73013 , ISBN 978-3-030-93072-1 , https://doi.org/10.1007/978-3-030-93072-1_11
- Description: Urbanization is one of the major social changes sweeping the globe, with rapid growth of the urban population and stagnating growth of the rural population, especially in developing regions (UN-Habitat, 2020). In subSaharan Africa, rapid urbanization and poverty are the major fundamental development challenges that are perpetuating and deepening the crisis of food and nutrition insecurity in urban areas (Battersby, 2012). Many people living in urban areas face under-nutrition, mainly due to their lack of income rather than to a lack of capacity to produce food (Satterthwaite et al., 2010). The health and nutritional status of urban populations with very low incomes are at risk from rising prices in staple foods. This became evident with the rising hunger among urban populations after the food price rises in 2007 and the first half of 2008 (Cohen and Garrett, 2009). In South Africa, poverty, unemployment and high food prices are dominant and influence dietary change, which subsequently increases urban food insecurity and malnutrition (Battersby, 2012).
- Full Text:
- Date Issued: 2022
- Authors: Chakona, Gamuchirai
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433943 , vital:73013 , ISBN 978-3-030-93072-1 , https://doi.org/10.1007/978-3-030-93072-1_11
- Description: Urbanization is one of the major social changes sweeping the globe, with rapid growth of the urban population and stagnating growth of the rural population, especially in developing regions (UN-Habitat, 2020). In subSaharan Africa, rapid urbanization and poverty are the major fundamental development challenges that are perpetuating and deepening the crisis of food and nutrition insecurity in urban areas (Battersby, 2012). Many people living in urban areas face under-nutrition, mainly due to their lack of income rather than to a lack of capacity to produce food (Satterthwaite et al., 2010). The health and nutritional status of urban populations with very low incomes are at risk from rising prices in staple foods. This became evident with the rising hunger among urban populations after the food price rises in 2007 and the first half of 2008 (Cohen and Garrett, 2009). In South Africa, poverty, unemployment and high food prices are dominant and influence dietary change, which subsequently increases urban food insecurity and malnutrition (Battersby, 2012).
- Full Text:
- Date Issued: 2022
How many people globally actually use non-timber forest products?
- Shackleton, Charlie M, de Vos, Alta
- Authors: Shackleton, Charlie M , de Vos, Alta
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/403200 , vital:69933 , xlink:href="https://doi.org/10.1016/j.forpol.2021.102659"
- Description: Non-timber forest products (NTFPs) are widely used wild, biological products harvested from rural and urban landscapes for household subsistence, income and culture, thereby contributing to human wellbeing. Estimates of the numbers of people making use of, or being dependent on, NTFPs vary widely, and global estimates to date have excluded urban populations and also NTFP users in the Global North. Additionally, most global or continental estimates are two or more decades old, and hence do not account for significant worldwide changes in societies, cultures, economies and landscapes since the estimates were made. Here we collate more recent empirical studies reporting the number of NTFP users at fine scales that we extrapolate up for three broad regions, viz. rural areas of the Global South, urban areas of the Global South, and the Global North, as the basis for estimating the number of NTFP users globally. We calculate the lower and upper bounds, as well a median estimate. We find the lowest and median approximations to be 3.5 billion and 5.76 billion users globally, respectively, based on conservative approaches. This is more than double and triple, respectively, the oft cited and dated figure of 1.6 billion. Moreover, we find that only half of the global NTFP users are located in rural regions of the Global South, and that the other half are in urban areas and the Global North, showing that NTFPs are of importance across socio-economic and geographic regions, not just in remote and underdeveloped villages of the Global South. With such large numbers of users around the world, it is imperative that the supply, management, conservation and safeguarding of the values of NTFPs take a more central place in sectoral and development policies.
- Full Text:
- Date Issued: 2022
- Authors: Shackleton, Charlie M , de Vos, Alta
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/403200 , vital:69933 , xlink:href="https://doi.org/10.1016/j.forpol.2021.102659"
- Description: Non-timber forest products (NTFPs) are widely used wild, biological products harvested from rural and urban landscapes for household subsistence, income and culture, thereby contributing to human wellbeing. Estimates of the numbers of people making use of, or being dependent on, NTFPs vary widely, and global estimates to date have excluded urban populations and also NTFP users in the Global North. Additionally, most global or continental estimates are two or more decades old, and hence do not account for significant worldwide changes in societies, cultures, economies and landscapes since the estimates were made. Here we collate more recent empirical studies reporting the number of NTFP users at fine scales that we extrapolate up for three broad regions, viz. rural areas of the Global South, urban areas of the Global South, and the Global North, as the basis for estimating the number of NTFP users globally. We calculate the lower and upper bounds, as well a median estimate. We find the lowest and median approximations to be 3.5 billion and 5.76 billion users globally, respectively, based on conservative approaches. This is more than double and triple, respectively, the oft cited and dated figure of 1.6 billion. Moreover, we find that only half of the global NTFP users are located in rural regions of the Global South, and that the other half are in urban areas and the Global North, showing that NTFPs are of importance across socio-economic and geographic regions, not just in remote and underdeveloped villages of the Global South. With such large numbers of users around the world, it is imperative that the supply, management, conservation and safeguarding of the values of NTFPs take a more central place in sectoral and development policies.
- Full Text:
- Date Issued: 2022