“Eye on the big prize!”: Iconizing the Democratic Alliance in the Daily Sun
- Siebörger, Ian, Adendorff, Ralph D
- Authors: Siebörger, Ian , Adendorff, Ralph D
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/385324 , vital:68007 , xlink:href="https://www.ajol.info/index.php/splp/article/view/253996"
- Description: This article gives a snapshot view of how Mmusi Maimane’s rise to leadership in the Democratic Alliance (DA) in 2015 was reported on in the Daily Sun, South Africa’s biggest-selling national daily newspaper (South African Audience Research Foundation, 2016). Through analysis of a Daily Sun news article exemplifying trends in the positioning of the DA in the tabloid over the first half of 2015, the present study demonstrates how Maimane tried to align the DA around a new iconography (Tann 2010, 2013), centred on the values of “freedom”, “fairness” and “opportunity”. Moreover, the present study also shows how this purported transformation in the DA was treated with scepticism by the news article’s author, who iconizes the DA as incapable of transformation and effective governance. Fine-grained complementary Legitimation Code Theory (LCT) and Systemic Functional Linguistics (SFL) analyses were conducted on this news article. The LCT analysis shows how multiple voices in the news article create conflicting binary constellations, axiologically charged through various linguistic resources, including intertextual references. The analysis, using SFL’s Appraisal system (Martin and White 2005), shows how iconization is accomplished in the news article through evaluative language, coupled with intertextual references, grammatical metaphor andtechnicality to produce syndromes of meaning in the news article. Such iconization works, in this case, to reproduce an attitude of cynicism toward party politics in post-apartheid South Africa. This cynicism foreshadows Maimane’s ultimate lack of success in transforming the discourses of the DA.
- Full Text:
- Date Issued: 2022
- Authors: Siebörger, Ian , Adendorff, Ralph D
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/385324 , vital:68007 , xlink:href="https://www.ajol.info/index.php/splp/article/view/253996"
- Description: This article gives a snapshot view of how Mmusi Maimane’s rise to leadership in the Democratic Alliance (DA) in 2015 was reported on in the Daily Sun, South Africa’s biggest-selling national daily newspaper (South African Audience Research Foundation, 2016). Through analysis of a Daily Sun news article exemplifying trends in the positioning of the DA in the tabloid over the first half of 2015, the present study demonstrates how Maimane tried to align the DA around a new iconography (Tann 2010, 2013), centred on the values of “freedom”, “fairness” and “opportunity”. Moreover, the present study also shows how this purported transformation in the DA was treated with scepticism by the news article’s author, who iconizes the DA as incapable of transformation and effective governance. Fine-grained complementary Legitimation Code Theory (LCT) and Systemic Functional Linguistics (SFL) analyses were conducted on this news article. The LCT analysis shows how multiple voices in the news article create conflicting binary constellations, axiologically charged through various linguistic resources, including intertextual references. The analysis, using SFL’s Appraisal system (Martin and White 2005), shows how iconization is accomplished in the news article through evaluative language, coupled with intertextual references, grammatical metaphor andtechnicality to produce syndromes of meaning in the news article. Such iconization works, in this case, to reproduce an attitude of cynicism toward party politics in post-apartheid South Africa. This cynicism foreshadows Maimane’s ultimate lack of success in transforming the discourses of the DA.
- Full Text:
- Date Issued: 2022
Working in poverty: Informal employment of household gardeners in Eastern Cape towns, South Africa
- King, A, Shackleton, Charlie M
- Authors: King, A , Shackleton, Charlie M
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/401398 , vital:69731 , xlink:href="https://doi.org/10.1080/0376835X.2021.1940867"
- Description: In South Africa there has been relatively little consideration of the informal employment offered to domestic household workers and gardeners. Here we report on the number and profile of gardeners employed by private households and the wage and satisfaction rates in 12 towns of the Eastern Cape. Over 98% of the informal gardeners were male, middle-aged and with limited formal schooling. Approximately 58% of middle and upper income households employed a gardener, at a mean daily rate of R112.20 in 2019. This equated to 13 170 gardeners earning a total wage bill of R139 million p.a. across the 12 towns, which scales up to 0.7–1 million informal gardeners nationally earning approximately R10–14 billion per year. However, daily remuneration was insufficient to cover basic needs, and slightly more than half of the gardeners would prefer a different job, indicating the survivalist nature of the sector.
- Full Text:
- Date Issued: 2022
- Authors: King, A , Shackleton, Charlie M
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/401398 , vital:69731 , xlink:href="https://doi.org/10.1080/0376835X.2021.1940867"
- Description: In South Africa there has been relatively little consideration of the informal employment offered to domestic household workers and gardeners. Here we report on the number and profile of gardeners employed by private households and the wage and satisfaction rates in 12 towns of the Eastern Cape. Over 98% of the informal gardeners were male, middle-aged and with limited formal schooling. Approximately 58% of middle and upper income households employed a gardener, at a mean daily rate of R112.20 in 2019. This equated to 13 170 gardeners earning a total wage bill of R139 million p.a. across the 12 towns, which scales up to 0.7–1 million informal gardeners nationally earning approximately R10–14 billion per year. However, daily remuneration was insufficient to cover basic needs, and slightly more than half of the gardeners would prefer a different job, indicating the survivalist nature of the sector.
- Full Text:
- Date Issued: 2022
Wooden pot engraved with elephant, rhinoceros and tree patterns
- Date: 2022 , 2022-10-06
- Subjects: Bam, Brigalia , Pots
- Language: English
- Type: realia
- Identifier: http://hdl.handle.net/10948/56995 , vital:57211
- Description: Wooden pot engraved with elephant, rhinoceros and tree patterns. , Donated/gifted to Nelson Mandela University Archives , Forms part of: Brigalia Bam collection
- Full Text: false
- Date Issued: 2022
- Date: 2022 , 2022-10-06
- Subjects: Bam, Brigalia , Pots
- Language: English
- Type: realia
- Identifier: http://hdl.handle.net/10948/56995 , vital:57211
- Description: Wooden pot engraved with elephant, rhinoceros and tree patterns. , Donated/gifted to Nelson Mandela University Archives , Forms part of: Brigalia Bam collection
- Full Text: false
- Date Issued: 2022
White crocheted circular doily
- Date: 2022 , 2022-10-05
- Subjects: Bam, Brigalia , Doilies , Crochet
- Language: English
- Type: realia
- Identifier: http://hdl.handle.net/10948/56834 , vital:57193
- Description: White crocheted circular doily, made by Mrs. Bam Senior. , Donated/gifted to Nelson Mandela Archives , Forms part of: Brigalia Bam collection
- Full Text: false
- Date Issued: 2022
- Date: 2022 , 2022-10-05
- Subjects: Bam, Brigalia , Doilies , Crochet
- Language: English
- Type: realia
- Identifier: http://hdl.handle.net/10948/56834 , vital:57193
- Description: White crocheted circular doily, made by Mrs. Bam Senior. , Donated/gifted to Nelson Mandela Archives , Forms part of: Brigalia Bam collection
- Full Text: false
- Date Issued: 2022
What’s in a conference theme?: Some reflections on critical realist research and its emergence in Africa over a period of 20+ years
- Authors: Lotz-Sisitka, Heila
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/370739 , vital:66372 , xlink:href="https://doi.org/10.1080/14767430.2023.2146923"
- Description: In keeping with the 2021 IACR Conference theme (Re) Envisaging Emancipatory Research, Science and Practice, this paper reviews over fifty instances of critical realist research in Africa which have sought to establish emancipatory research praxis by using critical realism to underlabour a range of applied studies in a diversity of disciplines and countries. The initiators of this research have been drawn to critical realism for several reasons, most notably its return to ontology, its interest in transformed, transformative praxis, and its potential for addressing knowledge and experiences exclusions. The paper ends with a reflection on ‘What's in a Conference Theme', returning to the earlier 2012 IACR conference hosted in Africa, and the 2021 conference’s focus on emancipatory research. It argues both for the deepening of conversations between critical realism and Africana Critical Theory; and for the grounding of these conversations in the voices and power of the people in our communities
- Full Text:
- Date Issued: 2022
- Authors: Lotz-Sisitka, Heila
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/370739 , vital:66372 , xlink:href="https://doi.org/10.1080/14767430.2023.2146923"
- Description: In keeping with the 2021 IACR Conference theme (Re) Envisaging Emancipatory Research, Science and Practice, this paper reviews over fifty instances of critical realist research in Africa which have sought to establish emancipatory research praxis by using critical realism to underlabour a range of applied studies in a diversity of disciplines and countries. The initiators of this research have been drawn to critical realism for several reasons, most notably its return to ontology, its interest in transformed, transformative praxis, and its potential for addressing knowledge and experiences exclusions. The paper ends with a reflection on ‘What's in a Conference Theme', returning to the earlier 2012 IACR conference hosted in Africa, and the 2021 conference’s focus on emancipatory research. It argues both for the deepening of conversations between critical realism and Africana Critical Theory; and for the grounding of these conversations in the voices and power of the people in our communities
- Full Text:
- Date Issued: 2022
Vintage wooden fountain pen holder, with colorful decoupage pattern
- Date: 2022 , 2022-10-05
- Subjects: Bam, Brigalia
- Language: English
- Type: realia
- Identifier: http://hdl.handle.net/10948/56844 , vital:57194
- Description: Vintage wooden fountain pen holder, with colorful decoupage pattern, without the pen. , Donated/gifted to Nelson Mandela University Archives , Forms part of: Brigalia Bam collection
- Full Text: false
- Date Issued: 2022
- Date: 2022 , 2022-10-05
- Subjects: Bam, Brigalia
- Language: English
- Type: realia
- Identifier: http://hdl.handle.net/10948/56844 , vital:57194
- Description: Vintage wooden fountain pen holder, with colorful decoupage pattern, without the pen. , Donated/gifted to Nelson Mandela University Archives , Forms part of: Brigalia Bam collection
- Full Text: false
- Date Issued: 2022
Validity of categories related to gender identity in ICD-11 and DSM-5 among transgender individuals who seek gender-affirming medical procedures
- Robles, Rebeca, Keeley, Jared W, Vega-Ramírez, H, Cruz-Islas, Jeremy, Rodríguez-Pérez, Victor, Sharan, Pratap, Purnima, Shivani, Rao, Ravindra, Rodrigues-Lobato, María I, Soll, Bianca, Askevis-Leherpeux, Françoise, Roelandt, Jean-Luc, Campbell, Megan, Grobler, Gerhard, Stein, Dan H, Khoury, Brigitte, El Khoury, Joseph, Fresán, Ana, Medina-Mora, María, Reed, Geoffrey M
- Authors: Robles, Rebeca , Keeley, Jared W , Vega-Ramírez, H , Cruz-Islas, Jeremy , Rodríguez-Pérez, Victor , Sharan, Pratap , Purnima, Shivani , Rao, Ravindra , Rodrigues-Lobato, María I , Soll, Bianca , Askevis-Leherpeux, Françoise , Roelandt, Jean-Luc , Campbell, Megan , Grobler, Gerhard , Stein, Dan H , Khoury, Brigitte , El Khoury, Joseph , Fresán, Ana , Medina-Mora, María , Reed, Geoffrey M
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/302589 , vital:58210 , xlink:href="https://doi.org/10.1016/j.ijchp.2021.100281"
- Description: Background/Objective: The most recent versions of the two main mental disorders classifications—the World Health Organization's ICD-11 and the American Psychiatric Association's DSM–5—differ substantially in their diagnostic categories related to transgender identity. ICD-11 gender incongruence (GI), in contrast to DSM-5 gender dysphoria (GD), is explicitly not a mental disorder; neither distress nor dysfunction is a required feature. The objective was compared ICD-11 and DSM-5 diagnostic requirements in terms of their sensitivity, specificity, discriminability and ability to predict the use of gender-affirming medical procedures. Method: A total of 649 of transgender adults in six countries completed a retrospective structured interview. Results: Using ROC analysis, sensitivity of the diagnostic requirements was equivalent for both systems, but ICD-11 showed greater specificity than DSM-5. Regression analyses indicated that history of hormones and/or surgery was predicted by variables that are an intrinsic aspect of GI/GD more than by distress and dysfunction. IRT analyses showed that the ICD-11 diagnostic formulation was more parsimonious and contained more information about caseness than the DSM-5 model. Conclusions: This study supports the ICD-11 position that GI/GD is not a mental disorder; additional diagnostic requirements of distress and/or dysfunction in DSM-5 reduce the predictive power of the diagnostic model.
- Full Text:
- Date Issued: 2022
- Authors: Robles, Rebeca , Keeley, Jared W , Vega-Ramírez, H , Cruz-Islas, Jeremy , Rodríguez-Pérez, Victor , Sharan, Pratap , Purnima, Shivani , Rao, Ravindra , Rodrigues-Lobato, María I , Soll, Bianca , Askevis-Leherpeux, Françoise , Roelandt, Jean-Luc , Campbell, Megan , Grobler, Gerhard , Stein, Dan H , Khoury, Brigitte , El Khoury, Joseph , Fresán, Ana , Medina-Mora, María , Reed, Geoffrey M
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/302589 , vital:58210 , xlink:href="https://doi.org/10.1016/j.ijchp.2021.100281"
- Description: Background/Objective: The most recent versions of the two main mental disorders classifications—the World Health Organization's ICD-11 and the American Psychiatric Association's DSM–5—differ substantially in their diagnostic categories related to transgender identity. ICD-11 gender incongruence (GI), in contrast to DSM-5 gender dysphoria (GD), is explicitly not a mental disorder; neither distress nor dysfunction is a required feature. The objective was compared ICD-11 and DSM-5 diagnostic requirements in terms of their sensitivity, specificity, discriminability and ability to predict the use of gender-affirming medical procedures. Method: A total of 649 of transgender adults in six countries completed a retrospective structured interview. Results: Using ROC analysis, sensitivity of the diagnostic requirements was equivalent for both systems, but ICD-11 showed greater specificity than DSM-5. Regression analyses indicated that history of hormones and/or surgery was predicted by variables that are an intrinsic aspect of GI/GD more than by distress and dysfunction. IRT analyses showed that the ICD-11 diagnostic formulation was more parsimonious and contained more information about caseness than the DSM-5 model. Conclusions: This study supports the ICD-11 position that GI/GD is not a mental disorder; additional diagnostic requirements of distress and/or dysfunction in DSM-5 reduce the predictive power of the diagnostic model.
- Full Text:
- Date Issued: 2022
Understanding rural–urban transitions in the Global South through peri-urban turbulence
- Hutchings, Paul, Willcock, Simon, Lynch, Kenneth, Bundhoo, Dilshaad, Brewer, Tim, Cooper, Sarah, Keech, Daniel, Mekala, Sneha, Mishra, Prajna P, Parker, Alison, Shackleton, Charlie M, Venkatesh, Kongala, Vicario, Dolores R, Welivita, Indunee
- Authors: Hutchings, Paul , Willcock, Simon , Lynch, Kenneth , Bundhoo, Dilshaad , Brewer, Tim , Cooper, Sarah , Keech, Daniel , Mekala, Sneha , Mishra, Prajna P , Parker, Alison , Shackleton, Charlie M , Venkatesh, Kongala , Vicario, Dolores R , Welivita, Indunee
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/401368 , vital:69729 , xlink:href="https://doi.org/10.1038/s41893-022-00920-w"
- Description: Much previous research has problematized the use of a binary urban–rural distinction to describe human settlement patterns in and around cities. Peri-urban zones, on the edge of urban settlements, are important both in the sheer magnitude of human population and in terms of being home to vulnerable populations with high rates of poverty. This Perspective presents a framework that conceptualizes rural–urban transition through the prism of shifts in natural, engineered and institutional infrastructure to explain the processes of rapid change and the dip in service provision often found in peri-urban areas in the Global South. We draw on examples related to the provision of water and sanitation to illustrate the theory and discuss its implications for future research on the peri-urban. A research agenda is set out that emphasizes the importance of studying early warning signs of service dips using systems theory concepts such as flickering and critical slowing down. Through such approaches, research can better predict and explain what we call peri-urban turbulence and inform the development of mitigation strategies to reduce the vulnerabilities that peri-urban residents too often face during periods of rural–urban transition.
- Full Text:
- Date Issued: 2022
- Authors: Hutchings, Paul , Willcock, Simon , Lynch, Kenneth , Bundhoo, Dilshaad , Brewer, Tim , Cooper, Sarah , Keech, Daniel , Mekala, Sneha , Mishra, Prajna P , Parker, Alison , Shackleton, Charlie M , Venkatesh, Kongala , Vicario, Dolores R , Welivita, Indunee
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/401368 , vital:69729 , xlink:href="https://doi.org/10.1038/s41893-022-00920-w"
- Description: Much previous research has problematized the use of a binary urban–rural distinction to describe human settlement patterns in and around cities. Peri-urban zones, on the edge of urban settlements, are important both in the sheer magnitude of human population and in terms of being home to vulnerable populations with high rates of poverty. This Perspective presents a framework that conceptualizes rural–urban transition through the prism of shifts in natural, engineered and institutional infrastructure to explain the processes of rapid change and the dip in service provision often found in peri-urban areas in the Global South. We draw on examples related to the provision of water and sanitation to illustrate the theory and discuss its implications for future research on the peri-urban. A research agenda is set out that emphasizes the importance of studying early warning signs of service dips using systems theory concepts such as flickering and critical slowing down. Through such approaches, research can better predict and explain what we call peri-urban turbulence and inform the development of mitigation strategies to reduce the vulnerabilities that peri-urban residents too often face during periods of rural–urban transition.
- Full Text:
- Date Issued: 2022
Ultrasensitive detection of prostate-specific antigen using glucose-encapsulated nanoliposomes anti-PSA polyclonal antibody as detection nanobioprobes
- Mwanza, Daniel, Mfamela, Nololo, Adeniyi, Omotayo, Nyokong, Tebello, Mashazi, Philani N
- Authors: Mwanza, Daniel , Mfamela, Nololo , Adeniyi, Omotayo , Nyokong, Tebello , Mashazi, Philani N
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300268 , vital:57911 , xlink:href="https://doi.org/10.1016/j.talanta.2022.123483"
- Description: In this work, the preparation of glucose encapsulating nanoliposomes was achieved using two different lipid formulations, labelled as F1 and F2. Both formulations contained phosphatidylcholine (PC), oleylamido-4-butanoic acid (OABA) and in addition, F1 had cholesterol (CHO) while F2 contained cholesteroyl hemisussinate (CHEMS). These formulations were studied for their pH sensitivity and controlled release of encapsulated glucose for indirect detection of prostate-specific antigen (PSA) using sandwich immunoassay. As a signal generator, encapsulated glucose in nanoliposomes was quantified directly using the personal glucose meter (PGM) and colorimetrically using peroxidase property of horseradish peroxidase (HRP) enzyme and Pd|PdO as nanozymes. Controlled release of the encapsulated glucose was achieved using the pH effect or Triton-X 100 as a surfactant to destabilize the liposomal structure. The F2 formulation showed maximum controlled release at acidic phosphate buffer saline (PBS, pH 5.0). The concentration of encapsulated glucose was found to be high in F2 formulation and these were applied for the indirect detection of PSA. The limit of detection (LOD) values for PSA were found to be 53 fg mL−1, 64 fg mL−1 and 10 fg mL−1 when HRP, Pd|PdO and PGM were respectively used. The detection signal was linear over a wide concentration range for PSA including the clinical range of 4–10 ng mL−1. The HRP system showed low LOD value when compared with Pd|PdO nanozymes. PGM system gave lowest LOD values owing to the sensitivity of the system towards glucose. Pd|PdO nanozyme system showed good stability over a wide temperature up to 80 °C. PGM system required less reaction time (2 min), low reagents and results were readily generated in digital format.
- Full Text:
- Date Issued: 2022
- Authors: Mwanza, Daniel , Mfamela, Nololo , Adeniyi, Omotayo , Nyokong, Tebello , Mashazi, Philani N
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300268 , vital:57911 , xlink:href="https://doi.org/10.1016/j.talanta.2022.123483"
- Description: In this work, the preparation of glucose encapsulating nanoliposomes was achieved using two different lipid formulations, labelled as F1 and F2. Both formulations contained phosphatidylcholine (PC), oleylamido-4-butanoic acid (OABA) and in addition, F1 had cholesterol (CHO) while F2 contained cholesteroyl hemisussinate (CHEMS). These formulations were studied for their pH sensitivity and controlled release of encapsulated glucose for indirect detection of prostate-specific antigen (PSA) using sandwich immunoassay. As a signal generator, encapsulated glucose in nanoliposomes was quantified directly using the personal glucose meter (PGM) and colorimetrically using peroxidase property of horseradish peroxidase (HRP) enzyme and Pd|PdO as nanozymes. Controlled release of the encapsulated glucose was achieved using the pH effect or Triton-X 100 as a surfactant to destabilize the liposomal structure. The F2 formulation showed maximum controlled release at acidic phosphate buffer saline (PBS, pH 5.0). The concentration of encapsulated glucose was found to be high in F2 formulation and these were applied for the indirect detection of PSA. The limit of detection (LOD) values for PSA were found to be 53 fg mL−1, 64 fg mL−1 and 10 fg mL−1 when HRP, Pd|PdO and PGM were respectively used. The detection signal was linear over a wide concentration range for PSA including the clinical range of 4–10 ng mL−1. The HRP system showed low LOD value when compared with Pd|PdO nanozymes. PGM system gave lowest LOD values owing to the sensitivity of the system towards glucose. Pd|PdO nanozyme system showed good stability over a wide temperature up to 80 °C. PGM system required less reaction time (2 min), low reagents and results were readily generated in digital format.
- Full Text:
- Date Issued: 2022
Trees stocks in domestic gardens and willingness to participate in tree planting initiatives in low-cost housing areas of the Eastern Cape, South Africa
- Gwedla, Nanamhla, Shackleton, Charlie, Olvitt, Lausanne L
- Authors: Gwedla, Nanamhla , Shackleton, Charlie , Olvitt, Lausanne L
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/372825 , vital:66626 , xlink:href="https://doi.org/10.1016/j.ufug.2022.127484"
- Description: Increasing human populations and rapid urbanization in sub-Saharan Africa have prompted the development and maintenance of urban green infrastructure, including urban trees for sustainability, human wellbeing, liveability and climate resilience. However, there are still insufficient amounts and large inequities in the distribution of trees between and within towns and cities of the Global North and South. In South Africa, urban green space planning and planting are encoded in several policies at national level. However, these policies are rarely translated into specific guides, standards or actions, and consequently disparities in urban trees and green space distribution persist. This study assessed the prevalence of urban trees in domestic gardens in low-cost housing areas (LCHAs) of eight small to medium-sized towns in the Eastern Cape province of South Africa and examined residents’ perceptions in this regard. This was done via surveys with 800 households in old and recently developed LCHAs. The results revealed that most households (52 %) had at least one tree in their yard, with more households in the older neighbourhoods (60 %) reporting having trees than in the newer ones (44 %). Most of the trees (66 %) had been deliberately planted as opposed to natural regeneration. Experience of formal urban tree planting programs was low, but 75 % of residents expressed willingness to participate in the future, preferably in tree planting and maintenance. Urban green spaces and trees cannot be an afterthought in the development of sustainable human settlements, and municipal plans should reflect tangible commitments in this regard. Meeting goals for greener LCHAs requires the involvement of local residents, and for municipal authorities to be receptive to the wishes of residents and willingness to green their residential areas.
- Full Text:
- Date Issued: 2022
- Authors: Gwedla, Nanamhla , Shackleton, Charlie , Olvitt, Lausanne L
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/372825 , vital:66626 , xlink:href="https://doi.org/10.1016/j.ufug.2022.127484"
- Description: Increasing human populations and rapid urbanization in sub-Saharan Africa have prompted the development and maintenance of urban green infrastructure, including urban trees for sustainability, human wellbeing, liveability and climate resilience. However, there are still insufficient amounts and large inequities in the distribution of trees between and within towns and cities of the Global North and South. In South Africa, urban green space planning and planting are encoded in several policies at national level. However, these policies are rarely translated into specific guides, standards or actions, and consequently disparities in urban trees and green space distribution persist. This study assessed the prevalence of urban trees in domestic gardens in low-cost housing areas (LCHAs) of eight small to medium-sized towns in the Eastern Cape province of South Africa and examined residents’ perceptions in this regard. This was done via surveys with 800 households in old and recently developed LCHAs. The results revealed that most households (52 %) had at least one tree in their yard, with more households in the older neighbourhoods (60 %) reporting having trees than in the newer ones (44 %). Most of the trees (66 %) had been deliberately planted as opposed to natural regeneration. Experience of formal urban tree planting programs was low, but 75 % of residents expressed willingness to participate in the future, preferably in tree planting and maintenance. Urban green spaces and trees cannot be an afterthought in the development of sustainable human settlements, and municipal plans should reflect tangible commitments in this regard. Meeting goals for greener LCHAs requires the involvement of local residents, and for municipal authorities to be receptive to the wishes of residents and willingness to green their residential areas.
- Full Text:
- Date Issued: 2022
Transforming Education for Sustainable Futures: Intersecting dynamics of food, water, livelihoods and education in the COVID-19 pandemic
- Velempini, Kgosietsile, Lotz-Sisitka, Heila, Kulundu, Injairu, Maqwelane, Lwanda, James, Anna, Mphepo, Gibson, Dyantyi, Phila, Kunkwenza, Esthery
- Authors: Velempini, Kgosietsile , Lotz-Sisitka, Heila , Kulundu, Injairu , Maqwelane, Lwanda , James, Anna , Mphepo, Gibson , Dyantyi, Phila , Kunkwenza, Esthery
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/389903 , vital:68494 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/211392"
- Description: Since 2019, the COVID-19 pandemic has posed challenges to but also highlighted the urgent need for transforming education for sustainable futures. The purpose of this article is to share insights gained from a southern African study on intersecting influences of water, food, livelihoods and education, and what they mean for Education for Sustainable Development going forward. The interest is to learn from this study in ways that can inform transformation of education for sustainable futures in southern Africa going forward. The study involved a number of early career researchers in SADC countries, and was conducted via an online approach during the early days of the pandemic. It followed a qualitative research design, employed document analysis, interviews and questionnaires, and drew on a systems perspective to inform analysis. The findings are as relevant today as they were in the pandemic, and point to the importance of giving attention to intersecting issues that affect education. The study highlights six transformative praxis pathways for transforming education for sustainable futures.
- Full Text:
- Date Issued: 2022
- Authors: Velempini, Kgosietsile , Lotz-Sisitka, Heila , Kulundu, Injairu , Maqwelane, Lwanda , James, Anna , Mphepo, Gibson , Dyantyi, Phila , Kunkwenza, Esthery
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/389903 , vital:68494 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/211392"
- Description: Since 2019, the COVID-19 pandemic has posed challenges to but also highlighted the urgent need for transforming education for sustainable futures. The purpose of this article is to share insights gained from a southern African study on intersecting influences of water, food, livelihoods and education, and what they mean for Education for Sustainable Development going forward. The interest is to learn from this study in ways that can inform transformation of education for sustainable futures in southern Africa going forward. The study involved a number of early career researchers in SADC countries, and was conducted via an online approach during the early days of the pandemic. It followed a qualitative research design, employed document analysis, interviews and questionnaires, and drew on a systems perspective to inform analysis. The findings are as relevant today as they were in the pandemic, and point to the importance of giving attention to intersecting issues that affect education. The study highlights six transformative praxis pathways for transforming education for sustainable futures.
- Full Text:
- Date Issued: 2022
Towards SDG 15.3: The biome context as the appropriate degradation monitoring dimension
- Xoxo, Sinetemba, Mantel, Sukhmani, de Vos, Alta, Mahlaba, Bawinile, le Maître, David, Tanner, Jane
- Authors: Xoxo, Sinetemba , Mantel, Sukhmani , de Vos, Alta , Mahlaba, Bawinile , le Maître, David , Tanner, Jane
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/415961 , vital:71304 , xlink:href="https://doi.org/10.1016/j.envsci.2022.07.008"
- Description: Accurate and reliable estimation of terrestrial ecosystem degradation is critical to meeting the challenge of reversing land degradation. Remote sensing data (especially land productivity dynamics) is commonly used to estimate land degradation, and this study uses the TRENDS.EARTH toolbox for the period covering 2000–2018, demonstrating the benefit of tracking the degradation process (SDG 15.3.1) at a biophysical unit. Contributing to the country’s SDG 15.3.1 monitoring, anthropogenic degradation was estimated based on RESTREND land productivity, biome-specific land cover trends, and soil organic carbon (SOC) stocks. Underlying degradation was evaluated by reclassifying a 28-year national land cover change dataset to match the UNCCD land cover legend. Analysis results indicate that land productivity changes (especially in stable grasslands, afforested, and cropland areas) mainly influenced the degradation status of the biome (19.9% degraded and 25.6% improvement). Global datasets also suggest that land cover and SOC had a minimal contribution (more than 2%) to anthropogenic degradation dynamics in the biome between 2000 and 2018. The GIS analysis showed that long-term, the major contributors to the biome’s underlying 9% anthropogenic degradation were woody proliferation into the Grassland Biome, urban expansion, and wetland drainage.
- Full Text:
- Date Issued: 2022
- Authors: Xoxo, Sinetemba , Mantel, Sukhmani , de Vos, Alta , Mahlaba, Bawinile , le Maître, David , Tanner, Jane
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/415961 , vital:71304 , xlink:href="https://doi.org/10.1016/j.envsci.2022.07.008"
- Description: Accurate and reliable estimation of terrestrial ecosystem degradation is critical to meeting the challenge of reversing land degradation. Remote sensing data (especially land productivity dynamics) is commonly used to estimate land degradation, and this study uses the TRENDS.EARTH toolbox for the period covering 2000–2018, demonstrating the benefit of tracking the degradation process (SDG 15.3.1) at a biophysical unit. Contributing to the country’s SDG 15.3.1 monitoring, anthropogenic degradation was estimated based on RESTREND land productivity, biome-specific land cover trends, and soil organic carbon (SOC) stocks. Underlying degradation was evaluated by reclassifying a 28-year national land cover change dataset to match the UNCCD land cover legend. Analysis results indicate that land productivity changes (especially in stable grasslands, afforested, and cropland areas) mainly influenced the degradation status of the biome (19.9% degraded and 25.6% improvement). Global datasets also suggest that land cover and SOC had a minimal contribution (more than 2%) to anthropogenic degradation dynamics in the biome between 2000 and 2018. The GIS analysis showed that long-term, the major contributors to the biome’s underlying 9% anthropogenic degradation were woody proliferation into the Grassland Biome, urban expansion, and wetland drainage.
- Full Text:
- Date Issued: 2022
Time-dependent characterization of graphene quantum dots and graphitic carbon nitride quantum dots synthesized by hydrothermal methods
- Nxele, Siphesihle Robin, Nyokong, Tebello
- Authors: Nxele, Siphesihle Robin , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/230917 , vital:49831 , xlink:href="https://doi.org/10.1016/j.diamond.2021.108751"
- Description: We report on the facile synthesis of graphene quantum dots (GQDs), nitrogen-doped quantum dots (NGQDs) and graphitic carbon nitride quantum dots (gCNQDs) by the bottom-up hydrothermal synthetic process. The time is varied to study its effects on the structural, hydrodynamic and optical properties of these nanostructures. The techniques used to characterize these nanostructures were transmission electron microscopy, X-ray diffractometry, dynamic light scattering, and zetametry (zeta potential), and by energy dispersive X-ray, UV/vis, fluorescence, Fourier transform infrared, Raman and X-ray photoelectron spectroscopies. For gCNQDs and NGQDs, Raman spectroscopy showed an increase in disorder with synthesis time, indicating introduction of more triazine groups for the former and increase in doping with the N atoms for the latter, hence higher temperatures are recommended. For GQDs, Raman spectra showed an increase in the spatial order of the π-conjugated structure with synthesis time. Considering all the techniques employed in this work, the synthesis times of 6h and 8 h are recommended for GQDs and NGQDs.
- Full Text:
- Date Issued: 2022
- Authors: Nxele, Siphesihle Robin , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/230917 , vital:49831 , xlink:href="https://doi.org/10.1016/j.diamond.2021.108751"
- Description: We report on the facile synthesis of graphene quantum dots (GQDs), nitrogen-doped quantum dots (NGQDs) and graphitic carbon nitride quantum dots (gCNQDs) by the bottom-up hydrothermal synthetic process. The time is varied to study its effects on the structural, hydrodynamic and optical properties of these nanostructures. The techniques used to characterize these nanostructures were transmission electron microscopy, X-ray diffractometry, dynamic light scattering, and zetametry (zeta potential), and by energy dispersive X-ray, UV/vis, fluorescence, Fourier transform infrared, Raman and X-ray photoelectron spectroscopies. For gCNQDs and NGQDs, Raman spectroscopy showed an increase in disorder with synthesis time, indicating introduction of more triazine groups for the former and increase in doping with the N atoms for the latter, hence higher temperatures are recommended. For GQDs, Raman spectra showed an increase in the spatial order of the π-conjugated structure with synthesis time. Considering all the techniques employed in this work, the synthesis times of 6h and 8 h are recommended for GQDs and NGQDs.
- Full Text:
- Date Issued: 2022
The use and value of wild harvested provisioning ecosystem services along a landscape heterogeneity gradient in rural South Africa
- Herd-Hoare, Shannon, Shackleton, Charlie M
- Authors: Herd-Hoare, Shannon , Shackleton, Charlie M
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/401341 , vital:69727 , xlink:href="https://doi.org/10.1080/26395916.2022.2140711"
- Description: Provisioning ecosystem services (PES) are typically crucial to rural livelihoods, especially in developing countries. However, the links between PES and local biodiversity or landscape heterogeneity are poorly explored. Here, we examined the extent of use and value of locally harvested wild, terrestrial and marine PES (such as wild foods, traditional medicines, firewood, building materials and others) in three villages (35–40 households per village) along a gradient of decreasing landscape heterogeneity. Households at the site with the highest landscape heterogeneity used a greater array of PES (9 ± 4) compared to the intermediate (5 ± 3) and least heterogenous (0.9 ± 0.8) sites. This resulted in a significantly greater annual value of PES to local livelihoods at the most diverse site (US$2 656 ± 2 587 per household), compared to US$1 120 ± 1 313 at the intermediate site and only US$105 ± 193 at the least heterogeneous site. This study shows the importance of access to a diversity of landscapes and PES to support rural livelihoods, which is frequently overlooked in PES valuation studies and in situations of land use change where landscape heterogeneity may decline.
- Full Text:
- Date Issued: 2022
- Authors: Herd-Hoare, Shannon , Shackleton, Charlie M
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/401341 , vital:69727 , xlink:href="https://doi.org/10.1080/26395916.2022.2140711"
- Description: Provisioning ecosystem services (PES) are typically crucial to rural livelihoods, especially in developing countries. However, the links between PES and local biodiversity or landscape heterogeneity are poorly explored. Here, we examined the extent of use and value of locally harvested wild, terrestrial and marine PES (such as wild foods, traditional medicines, firewood, building materials and others) in three villages (35–40 households per village) along a gradient of decreasing landscape heterogeneity. Households at the site with the highest landscape heterogeneity used a greater array of PES (9 ± 4) compared to the intermediate (5 ± 3) and least heterogenous (0.9 ± 0.8) sites. This resulted in a significantly greater annual value of PES to local livelihoods at the most diverse site (US$2 656 ± 2 587 per household), compared to US$1 120 ± 1 313 at the intermediate site and only US$105 ± 193 at the least heterogeneous site. This study shows the importance of access to a diversity of landscapes and PES to support rural livelihoods, which is frequently overlooked in PES valuation studies and in situations of land use change where landscape heterogeneity may decline.
- Full Text:
- Date Issued: 2022
The thermal physiology of Lysathia sp.(Coleoptera: Chrysomelidae), a biocontrol agent of parrot’s feather in South Africa, supports its success
- Goddard, Matthew, Owen, Candice A, Grant, Martin D, Coetzee, Julie A
- Authors: Goddard, Matthew , Owen, Candice A , Grant, Martin D , Coetzee, Julie A
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417806 , vital:71487 , xlink:href="https://doi.org/10.1080/09583157.2022.2054949"
- Description: The establishment success of biocontrol agents originating from tropical regions is often limited by climate when introduced in temperate regions. However, the flea beetle, Lysathia sp. (Coleoptera: Chrysomelidae), a biocontrol agent of Myriophyllum aquaticum (Vell.) Verdc. (Haloragaceae) in South Africa, is an effective agent in regions where other biocontrol agents of tropical aquatic weeds have failed due to winter-induced mortality. The development (degree-day model) and thermal tolerance (critical thermal minimum/maximum [CTmin/max] and lower/upper lethal limits [LLT/ULT50]) of Lysathia sp. were investigated to explain this success. The model predicted that Lysathia sp. could complete 6 to 12 generations per year in the colder regions of the country. The lower threshold for development (t0) was 13.0 °C and thermal constant (K) was 222.4 days, which is considerably lower than the K values of other biocontrol agents of aquatic weeds in South Africa. This suggests that above the temperature threshold, Lysathia sp. can develop faster than those other species and complete multiple life cycles in the cooler winter months, allowing for rapid population growth and thus improving M. aquaticum control. Furthermore, the CTmin of Lysathia sp. was 2.3 ± 0.2 °C and the CTmax was 49.0 ± 0.5 °C. The LLT50 was calculated as ∼ −7.0 °C and the ULT50 as ∼ 43.0 °C. These wide tolerance ranges and survival below freezing show why Lysathia sp. has established at cool sites and suggest that it may be a suitable agent for other cold countries invaded by M. aquaticum.
- Full Text:
- Date Issued: 2022
- Authors: Goddard, Matthew , Owen, Candice A , Grant, Martin D , Coetzee, Julie A
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417806 , vital:71487 , xlink:href="https://doi.org/10.1080/09583157.2022.2054949"
- Description: The establishment success of biocontrol agents originating from tropical regions is often limited by climate when introduced in temperate regions. However, the flea beetle, Lysathia sp. (Coleoptera: Chrysomelidae), a biocontrol agent of Myriophyllum aquaticum (Vell.) Verdc. (Haloragaceae) in South Africa, is an effective agent in regions where other biocontrol agents of tropical aquatic weeds have failed due to winter-induced mortality. The development (degree-day model) and thermal tolerance (critical thermal minimum/maximum [CTmin/max] and lower/upper lethal limits [LLT/ULT50]) of Lysathia sp. were investigated to explain this success. The model predicted that Lysathia sp. could complete 6 to 12 generations per year in the colder regions of the country. The lower threshold for development (t0) was 13.0 °C and thermal constant (K) was 222.4 days, which is considerably lower than the K values of other biocontrol agents of aquatic weeds in South Africa. This suggests that above the temperature threshold, Lysathia sp. can develop faster than those other species and complete multiple life cycles in the cooler winter months, allowing for rapid population growth and thus improving M. aquaticum control. Furthermore, the CTmin of Lysathia sp. was 2.3 ± 0.2 °C and the CTmax was 49.0 ± 0.5 °C. The LLT50 was calculated as ∼ −7.0 °C and the ULT50 as ∼ 43.0 °C. These wide tolerance ranges and survival below freezing show why Lysathia sp. has established at cool sites and suggest that it may be a suitable agent for other cold countries invaded by M. aquaticum.
- Full Text:
- Date Issued: 2022
The synergistic effects of coupling Au nanoparticles with an alkynyl Co (II) phthalocyanine on the detection of prostate specific antigen
- Nxele, Siphesihle Robin, Nkhahle, Reitumetse, Nyokong, Tebello
- Authors: Nxele, Siphesihle Robin , Nkhahle, Reitumetse , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/230232 , vital:49756 , xlink:href="https://doi.org/10.1016/j.talanta.2021.122948"
- Description: Prostate specific antigen (PSA) aptasensors are fabricated using a novel asymmetrically substituted Co phthalocyanine (CoPc), gold nanoparticles (AuNPs) and PSA-specific antigen. The fabricated aptasensors are: GCE-AuNPs-Aptamer, GCE@CoPc-Aptamer and GCE-AuNPs@CoPc-Aptamer (GCE = glassy carbon electrode). The fabricated sensors are characterized at each modification step to monitor the changes occurring at the sensor surface. Concentration studies were carried out using differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) to determine detection limits. All the fabricated aptasensors were found to be highly specific and selective but the GCE-AuNPs@CoPc-Aptamer nanoconjugate performed the best. The aptasensors were also tested in spiked serum samples and detection limits, as well as % recoveries were determined. The results obtained showed that the GCE-AuNPs@CoPc-Aptamer has the potential to be used for clinical studies as the results agree with those obtained for detection of PSA in buffer.
- Full Text:
- Date Issued: 2022
- Authors: Nxele, Siphesihle Robin , Nkhahle, Reitumetse , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/230232 , vital:49756 , xlink:href="https://doi.org/10.1016/j.talanta.2021.122948"
- Description: Prostate specific antigen (PSA) aptasensors are fabricated using a novel asymmetrically substituted Co phthalocyanine (CoPc), gold nanoparticles (AuNPs) and PSA-specific antigen. The fabricated aptasensors are: GCE-AuNPs-Aptamer, GCE@CoPc-Aptamer and GCE-AuNPs@CoPc-Aptamer (GCE = glassy carbon electrode). The fabricated sensors are characterized at each modification step to monitor the changes occurring at the sensor surface. Concentration studies were carried out using differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) to determine detection limits. All the fabricated aptasensors were found to be highly specific and selective but the GCE-AuNPs@CoPc-Aptamer nanoconjugate performed the best. The aptasensors were also tested in spiked serum samples and detection limits, as well as % recoveries were determined. The results obtained showed that the GCE-AuNPs@CoPc-Aptamer has the potential to be used for clinical studies as the results agree with those obtained for detection of PSA in buffer.
- Full Text:
- Date Issued: 2022
The prevalence, composition and distribution of forageable plant species in different urban spaces in two medium-sized towns in South Africa
- Garekae, Hesekia, Shackleton, Charlie M, Tsheboeng, Gaolathe
- Authors: Garekae, Hesekia , Shackleton, Charlie M , Tsheboeng, Gaolathe
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/401300 , vital:69724 , xlink:href="https://doi.org/10.1016/j.gecco.2021.e01972"
- Description: Globally, the importance of urban vegetation in the quality and maintenance of life in urban areas is increasingly recognized. As the basis of urban green infrastructure, urban vegetation provides a diversity of ecosystem services, including provisioning services. However, there is limited understanding of the potential of urban vegetation as a supply of forageable resources within urban landscapes. This study examined the prevalence and distribution of forageable plant species across different spaces in the towns of Potchefstroom and Thabazimbi, South Africa. A multi-stage sampling technique was employed for selecting study sites, with a total of 136 plots sampled. In total, 88 plant species (foraged and forageable) were encountered across the sample plots, with almost three-quarters (70%) being indigenous to South Africa. Most of the species had multiple uses, with medicine, food and firewood being the most common uses, in order of frequency. Species cover and richness significantly differed across the urban spaces, being markedly higher in protected areas as compared to other spaces. Moreover, five plant communities were identified, resembling various species uses. Overall, the findings show that the fragmented urban spaces are endowed with a diversity of forageable plant species, with many valuable to particular sectors of urban society, such as foragers. Moreover, the notable number of forageable plant species encountered across the different spaces demonstrates the potential of urban green infrastructure as a supply of provisioning and cultural ecosystem services. This provides the basis for the selection of a diversity of species in urban greening programs for enhancing liveability and overall well-being in urban areas.
- Full Text:
- Date Issued: 2022
- Authors: Garekae, Hesekia , Shackleton, Charlie M , Tsheboeng, Gaolathe
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/401300 , vital:69724 , xlink:href="https://doi.org/10.1016/j.gecco.2021.e01972"
- Description: Globally, the importance of urban vegetation in the quality and maintenance of life in urban areas is increasingly recognized. As the basis of urban green infrastructure, urban vegetation provides a diversity of ecosystem services, including provisioning services. However, there is limited understanding of the potential of urban vegetation as a supply of forageable resources within urban landscapes. This study examined the prevalence and distribution of forageable plant species across different spaces in the towns of Potchefstroom and Thabazimbi, South Africa. A multi-stage sampling technique was employed for selecting study sites, with a total of 136 plots sampled. In total, 88 plant species (foraged and forageable) were encountered across the sample plots, with almost three-quarters (70%) being indigenous to South Africa. Most of the species had multiple uses, with medicine, food and firewood being the most common uses, in order of frequency. Species cover and richness significantly differed across the urban spaces, being markedly higher in protected areas as compared to other spaces. Moreover, five plant communities were identified, resembling various species uses. Overall, the findings show that the fragmented urban spaces are endowed with a diversity of forageable plant species, with many valuable to particular sectors of urban society, such as foragers. Moreover, the notable number of forageable plant species encountered across the different spaces demonstrates the potential of urban green infrastructure as a supply of provisioning and cultural ecosystem services. This provides the basis for the selection of a diversity of species in urban greening programs for enhancing liveability and overall well-being in urban areas.
- Full Text:
- Date Issued: 2022
The photocatalytic properties of zinc phthalocyanines supported on hematite nanofibers for use against methyl orange and Staphylococcus aureus
- Mapukata, Sivuyisiwe, Britton, Jonathan, Nwahara, Nnamdi, Nyokong, Tebello
- Authors: Mapukata, Sivuyisiwe , Britton, Jonathan , Nwahara, Nnamdi , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/230184 , vital:49751 , xlink:href="https://doi.org/10.1016/j.jphotochem.2021.113637"
- Description: Heterogeneous photocatalysis is a promising approach for environmental remediation from contaminants including microorganisms and organic pollutants. In this work, hematite nanofibers are fabricated and modified with a novel monosubstituted Pc (4) as well as an asymmetrical tetrasubstituted Pc (5) with the aim of creating hybrid photocatalysts. The photocatalytic activities of the unmodified and phthalocyanine modified hematite nanofibers were compared based on their efficiencies in the photoinactivation of S. aureus and photooxidation of methyl orange. For both applications, the hybrid nanofibers were found to be more efficient photocatalysts than the unmodified hematite nanofibers. Comparison of the modified nanofibers (4-Fe2O3 and 5-Fe2O3) showed that they have comparable antibacterial activity while the 5-Fe2O3 nanofibers are the best for the photooxidation of methyl orange. The singlet oxygen generation efficiency, high activity, versatility, regenerability and thus reusability of the fabricated hybrid nanofibers makes them ideal candidates for real life water treatment studies.
- Full Text:
- Date Issued: 2022
- Authors: Mapukata, Sivuyisiwe , Britton, Jonathan , Nwahara, Nnamdi , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/230184 , vital:49751 , xlink:href="https://doi.org/10.1016/j.jphotochem.2021.113637"
- Description: Heterogeneous photocatalysis is a promising approach for environmental remediation from contaminants including microorganisms and organic pollutants. In this work, hematite nanofibers are fabricated and modified with a novel monosubstituted Pc (4) as well as an asymmetrical tetrasubstituted Pc (5) with the aim of creating hybrid photocatalysts. The photocatalytic activities of the unmodified and phthalocyanine modified hematite nanofibers were compared based on their efficiencies in the photoinactivation of S. aureus and photooxidation of methyl orange. For both applications, the hybrid nanofibers were found to be more efficient photocatalysts than the unmodified hematite nanofibers. Comparison of the modified nanofibers (4-Fe2O3 and 5-Fe2O3) showed that they have comparable antibacterial activity while the 5-Fe2O3 nanofibers are the best for the photooxidation of methyl orange. The singlet oxygen generation efficiency, high activity, versatility, regenerability and thus reusability of the fabricated hybrid nanofibers makes them ideal candidates for real life water treatment studies.
- Full Text:
- Date Issued: 2022
The nexus between petroleum energy security and South Africa’s foreign policy
- Authors: Seshibedi S S
- Date: 2022
- Subjects: Petroleum industry and trade -- Government policy , Energy industries , Petroleum law and legislation
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/27165 , vital:66325
- Description: This study sets out to explore the nexus between South Africa’s petroleum energy security and its foreign policy. The specific objectives of the research include: to find out the state of South Africa’s oil energy security, the extent to which oil is a consideration in the development of the country’s foreign policy and the extent to which its foreign policy is framed to favour oil exporting states. Qualitative research methodology is applied in this study with the Realism as the theoretical framework. The study found out that the state of South Africa’s oil energy security, which compels the country to rely on foreign oil, provides grounds for foreign policy intervention, with discernible espousal of relations with oil exporting states that is different to those that do not produce oil. The study also found that oil is a consideration in the development of South Africa’s foreign policy, as the country’s policy strategy towards oil exporting states is to build relations of bilateral nature, through diplomatic instruments, among others. South Africa’s regional politics makes discernible the fact that South Africa prefers a policy of multilateralism to manage its relations with SADC and SACU members who are not oil exporting, while evidence showed that bilateral relations are preferred towards oil exporting states. The study recommends amongst others, that South Africa’s over-reliance on foreign oil can be mitigated by taking the lead in transitioning to renewable energy. , Thesis (MSoc) -- Faculty of Social Sciences and Humanities, 2022
- Full Text:
- Date Issued: 2022
- Authors: Seshibedi S S
- Date: 2022
- Subjects: Petroleum industry and trade -- Government policy , Energy industries , Petroleum law and legislation
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/27165 , vital:66325
- Description: This study sets out to explore the nexus between South Africa’s petroleum energy security and its foreign policy. The specific objectives of the research include: to find out the state of South Africa’s oil energy security, the extent to which oil is a consideration in the development of the country’s foreign policy and the extent to which its foreign policy is framed to favour oil exporting states. Qualitative research methodology is applied in this study with the Realism as the theoretical framework. The study found out that the state of South Africa’s oil energy security, which compels the country to rely on foreign oil, provides grounds for foreign policy intervention, with discernible espousal of relations with oil exporting states that is different to those that do not produce oil. The study also found that oil is a consideration in the development of South Africa’s foreign policy, as the country’s policy strategy towards oil exporting states is to build relations of bilateral nature, through diplomatic instruments, among others. South Africa’s regional politics makes discernible the fact that South Africa prefers a policy of multilateralism to manage its relations with SADC and SACU members who are not oil exporting, while evidence showed that bilateral relations are preferred towards oil exporting states. The study recommends amongst others, that South Africa’s over-reliance on foreign oil can be mitigated by taking the lead in transitioning to renewable energy. , Thesis (MSoc) -- Faculty of Social Sciences and Humanities, 2022
- Full Text:
- Date Issued: 2022
The in vitro photo-sonodynamic combinatorial therapy activity of cationic and zwitterionic phthalocyanines on MCF-7 and HeLa cancer cell lines
- Nene, Lindokuhle Cindy, Buthelezi, Khanyisile, Prinsloo, Earl, Nyokong, Tebello
- Authors: Nene, Lindokuhle Cindy , Buthelezi, Khanyisile , Prinsloo, Earl , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295891 , vital:57387 , xlink:href="https://doi.org/10.1016/j.jphotochem.2022.114116"
- Description: The syntheses and characterization studies of zwitterionic 2,9,16,23-tetrakis-(N-propane sultone-morpholino) zinc(II) (4) and 2,9,16,23-tetrakis-(2,5-dimethyl-4-(N-propane sultone-morpholinomethyl))-phenoxy zinc(II) (6) phthalocyanines are reported in this work. The photophysical properties, reactive oxygen species (ROS) generation and in vitro anticancer photodynamic (PDT), sonodynamic (SDT), and photo-sonodynamic combination (PSDT) therapy activities of the Pcs were studied and compared to their cationic counterparts: (2,9,16,23-tetrakis-(N-methyl-morpholino) Zn(II)Pc, 3), (2,9,16,23-tetrakis-(2,5-dimethyl-4-(N-methylmorpholine)-phenoxy) Zn(II)Pc, 5). The cationic Pcs maintained higher anticancer activity for all treatment types and had higher ROS generation compared to the zwitterionic Pcs. Singlet oxygen and hydroxyl radicals were generated during ultrasound and combination irradiations of the Pcs. The zwitterionic Pcs also generated carbon radicals under ultrasound and combination irradiations. The ability of the Pcs to generate ROS is essential for PDT, SDT and PSDT, thus making these Pcs potential anticancer probes for these treatment types. Furthermore, the Pcs demonstrated the ability to bind to bovine serum albumin protein.
- Full Text:
- Date Issued: 2022
- Authors: Nene, Lindokuhle Cindy , Buthelezi, Khanyisile , Prinsloo, Earl , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295891 , vital:57387 , xlink:href="https://doi.org/10.1016/j.jphotochem.2022.114116"
- Description: The syntheses and characterization studies of zwitterionic 2,9,16,23-tetrakis-(N-propane sultone-morpholino) zinc(II) (4) and 2,9,16,23-tetrakis-(2,5-dimethyl-4-(N-propane sultone-morpholinomethyl))-phenoxy zinc(II) (6) phthalocyanines are reported in this work. The photophysical properties, reactive oxygen species (ROS) generation and in vitro anticancer photodynamic (PDT), sonodynamic (SDT), and photo-sonodynamic combination (PSDT) therapy activities of the Pcs were studied and compared to their cationic counterparts: (2,9,16,23-tetrakis-(N-methyl-morpholino) Zn(II)Pc, 3), (2,9,16,23-tetrakis-(2,5-dimethyl-4-(N-methylmorpholine)-phenoxy) Zn(II)Pc, 5). The cationic Pcs maintained higher anticancer activity for all treatment types and had higher ROS generation compared to the zwitterionic Pcs. Singlet oxygen and hydroxyl radicals were generated during ultrasound and combination irradiations of the Pcs. The zwitterionic Pcs also generated carbon radicals under ultrasound and combination irradiations. The ability of the Pcs to generate ROS is essential for PDT, SDT and PSDT, thus making these Pcs potential anticancer probes for these treatment types. Furthermore, the Pcs demonstrated the ability to bind to bovine serum albumin protein.
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- Date Issued: 2022