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
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
Exploring the community structure of Afrotropical macroinvertebrate traits and ecological preferences along an agricultural pollution gradient in the Kat River, Eastern Cape, South Africa
- Akamagwuna, Frank C, Odume, Oghenekaro N, Richoux, Nicole B
- Authors: Akamagwuna, Frank C , Odume, Oghenekaro N , Richoux, Nicole B
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/454334 , vital:75336 , xlink:href="https://doi.org/10.1016/j.ecolind.2022.108570"
- Description: Agricultural activities impact riverine ecosystem structure, function, and processes. In the Afrotropical regions, research on agricultural effects on macroinvertebrate trait distribution is sparse. In this study, we investigated the spatial and temporal changes in the community structure of macroinvertebrate traits along an agricultural disturbance gradient in an Afrotropical River system. Physicochemical variables were sampled alongside macroinvertebrates at eight sites in the dry (winter and spring) and wet (summer and autumn) periods of 2018–2019. We grouped the sites into four categories using the percentage of agricultural land-use cover within each drainage area. Our results showed that agricultural pollution exhibited varying effects on traits and ecological preferences, with traits such as a predatory lifestyle, medium body-size (>10–20 mm), active swimming, possession of spiracles and haemoglobin, and adult aquatic life stage increasing with the pollution gradient. These traits were positively associated with nutrients (PO4+-P, NO2+-N, NH4+-N and NO3+-N), salinity, turbidity and temperature and were deemed tolerant of agricultural pollution. Shredding, crawling, and a preference for macrophytes as food showed strong positive associations with the least disturbed sites and were negatively associated with increasing nutrients, salinity, turbidity and water temperature. As such, these three traits were considered sensitive to agricultural pollution. The identified indicator traits can be used to predict the survival and distribution patterns of organisms under the impact of agriculture-induced stress.
- Full Text:
- Date Issued: 2022
- Authors: Akamagwuna, Frank C , Odume, Oghenekaro N , Richoux, Nicole B
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/454334 , vital:75336 , xlink:href="https://doi.org/10.1016/j.ecolind.2022.108570"
- Description: Agricultural activities impact riverine ecosystem structure, function, and processes. In the Afrotropical regions, research on agricultural effects on macroinvertebrate trait distribution is sparse. In this study, we investigated the spatial and temporal changes in the community structure of macroinvertebrate traits along an agricultural disturbance gradient in an Afrotropical River system. Physicochemical variables were sampled alongside macroinvertebrates at eight sites in the dry (winter and spring) and wet (summer and autumn) periods of 2018–2019. We grouped the sites into four categories using the percentage of agricultural land-use cover within each drainage area. Our results showed that agricultural pollution exhibited varying effects on traits and ecological preferences, with traits such as a predatory lifestyle, medium body-size (>10–20 mm), active swimming, possession of spiracles and haemoglobin, and adult aquatic life stage increasing with the pollution gradient. These traits were positively associated with nutrients (PO4+-P, NO2+-N, NH4+-N and NO3+-N), salinity, turbidity and temperature and were deemed tolerant of agricultural pollution. Shredding, crawling, and a preference for macrophytes as food showed strong positive associations with the least disturbed sites and were negatively associated with increasing nutrients, salinity, turbidity and water temperature. As such, these three traits were considered sensitive to agricultural pollution. The identified indicator traits can be used to predict the survival and distribution patterns of organisms under the impact of agriculture-induced stress.
- 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 E
- Authors: McKenna, Sioux , Hlengwa, Amanda , Quinn, Lyn , Vorster, Jo-Anne E
- 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 E
- 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
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
How the Teaching Development Grant was used (and the problem of common-sense understandings of teaching and learning)
- Moyo, Temwa, McKenna, Sioux, Ndebele, Clever
- Authors: Moyo, Temwa , McKenna, Sioux , Ndebele, Clever
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426917 , vital:72400 , xlink:href="http://dx.doi.org/10.17159/2520-9868/i86a07"
- Description: Teachers at primary and secondary education levels are required to hold a professional qualification but, at the higher education level, all that is required is content expertise. This may well contribute to South Africa's low university throughput and retention rates, in response to which, since 2004, the state has provided ZAR5.5 billion in the form of the Teaching Development Grant (now the University Capacity Development Grant) to address poor completion rates. We present an analysis of the use of the grant across the sector using a social realist framework. Every academic and student has themselves been taught and so have developed untheorised assumptions about curriculum and pedagogy. Such common-sense assumptions about teaching and learning often serve to reinforce the status quo, which is particularly problematic in a sector with poor and racially differentiated throughput and success rates. Many initiatives funded through the grant evidenced a reliance on common-sense assumptions rather than on theorised accounts. In particular, student development often took the form of remedial, add-on initiatives that left the mainstream curriculum untouched-and staff development was often generic and short term. We also found that expertise in academic development, which could potentially challenge common-sense assumptions, was unevenly distributed.
- Full Text:
- Date Issued: 2022
- Authors: Moyo, Temwa , McKenna, Sioux , Ndebele, Clever
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426917 , vital:72400 , xlink:href="http://dx.doi.org/10.17159/2520-9868/i86a07"
- Description: Teachers at primary and secondary education levels are required to hold a professional qualification but, at the higher education level, all that is required is content expertise. This may well contribute to South Africa's low university throughput and retention rates, in response to which, since 2004, the state has provided ZAR5.5 billion in the form of the Teaching Development Grant (now the University Capacity Development Grant) to address poor completion rates. We present an analysis of the use of the grant across the sector using a social realist framework. Every academic and student has themselves been taught and so have developed untheorised assumptions about curriculum and pedagogy. Such common-sense assumptions about teaching and learning often serve to reinforce the status quo, which is particularly problematic in a sector with poor and racially differentiated throughput and success rates. Many initiatives funded through the grant evidenced a reliance on common-sense assumptions rather than on theorised accounts. In particular, student development often took the form of remedial, add-on initiatives that left the mainstream curriculum untouched-and staff development was often generic and short term. We also found that expertise in academic development, which could potentially challenge common-sense assumptions, was unevenly distributed.
- Full Text:
- Date Issued: 2022