An Application to Support end-users of wi-fi Hotspots in the Township of Makhanda
- Buwa, Lubabalo, Shibeshi, Zelalem S, Terzoli, Alfredo
- Authors: Buwa, Lubabalo , Shibeshi, Zelalem S , Terzoli, Alfredo
- Date: 2021
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429077 , vital:72558 , https://ieeexplore.ieee.org/abstract/document/9514200
- Description: Having access to the Internet is a powerful resource that can change one's life, but connectivity inequality continues to be a significant issue, especially for disadvantaged communities. The usage of Wi-Fi hotspots is becoming very useful for accommodating many people living in underprivileged areas to connect to the Internet. Primarily, these hotspots get deployed in public places like hotels, restaurants, etc. This paper discusses how such a system can be made to work as a solution for disadvantaged communities considering the user base in such communities and adhering to government regulations. The research is developed in collaboration with Khula Tech Solutions ISP that provides wireless Internet services in Makhanda (formally known as Grahamstown). Khula Tech Solutions is starting an initiative of installing Wi-Fi hotspots around the township of Makhanda and needs an application that will support users of the Wi-Fi hotspots. The research's result is a proof-of-concept mobile application developed through iterative and incremental software development techniques and mobile application technologies. With this research, the hope is that it is the beginning of further work for the users to become connected citizens.
- Full Text:
- Date Issued: 2021
- Authors: Buwa, Lubabalo , Shibeshi, Zelalem S , Terzoli, Alfredo
- Date: 2021
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429077 , vital:72558 , https://ieeexplore.ieee.org/abstract/document/9514200
- Description: Having access to the Internet is a powerful resource that can change one's life, but connectivity inequality continues to be a significant issue, especially for disadvantaged communities. The usage of Wi-Fi hotspots is becoming very useful for accommodating many people living in underprivileged areas to connect to the Internet. Primarily, these hotspots get deployed in public places like hotels, restaurants, etc. This paper discusses how such a system can be made to work as a solution for disadvantaged communities considering the user base in such communities and adhering to government regulations. The research is developed in collaboration with Khula Tech Solutions ISP that provides wireless Internet services in Makhanda (formally known as Grahamstown). Khula Tech Solutions is starting an initiative of installing Wi-Fi hotspots around the township of Makhanda and needs an application that will support users of the Wi-Fi hotspots. The research's result is a proof-of-concept mobile application developed through iterative and incremental software development techniques and mobile application technologies. With this research, the hope is that it is the beginning of further work for the users to become connected citizens.
- Full Text:
- Date Issued: 2021
An Examination of the Nexus between Environmental Knowledge and Environmental Learning Processes
- Chitsiga, Christina, Schudel, Ingrid J
- Authors: Chitsiga, Christina , Schudel, Ingrid J
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/435086 , vital:73129 , ISBN 9781928502241 , https://library.oapen.org/handle/20.500.12657/64082
- Description: Previous chapters in this book have discussed the complexity of environmental content (see Schudel and Lotz-Sisitka, Chapter 2; Isaacs and Olvitt, Chapter 4) and Chapter 8 (Schudel) has highlighted the significance and key elements of active and critical approaches to learning. The primary purpose of this chapter is to draw these two approaches together; that is, to explore the nexus of environmental content and environmental learning processes.
- Full Text:
- Date Issued: 2021
- Authors: Chitsiga, Christina , Schudel, Ingrid J
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/435086 , vital:73129 , ISBN 9781928502241 , https://library.oapen.org/handle/20.500.12657/64082
- Description: Previous chapters in this book have discussed the complexity of environmental content (see Schudel and Lotz-Sisitka, Chapter 2; Isaacs and Olvitt, Chapter 4) and Chapter 8 (Schudel) has highlighted the significance and key elements of active and critical approaches to learning. The primary purpose of this chapter is to draw these two approaches together; that is, to explore the nexus of environmental content and environmental learning processes.
- Full Text:
- Date Issued: 2021
An Exploration of what Grade 7 Natural Sciences Teachers Know, Believe and Say about Biodiversity and the Teaching of Biodiversity
- Isaacs, Dorelle, Olvitt, Lausanne L
- Authors: Isaacs, Dorelle , Olvitt, Lausanne L
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/435153 , vital:73134 , ISBN 9781928502241 , https://library.oapen.org/handle/20.500.12657/64082
- Description: This chapter shares the findings of a small-scale qualitative research project that investigated what three Grade 7 Natural Sciences teachers know, believe and say about biodiversity (Isaacs 2016). The study was sparked by the researcher’s interest in environmental learning and the importance of school curricula in preparing children to take care of their local and global environments. Biodiversity refers to Earth’s rich variety of plants and animals. It has been described as ‘the complex web of life’that includes diversity at genetic, species and ecosystem levels (Gurr et al. 2012: 4). The concept came to prominence in 1992 when the United Nations’ Convention on Biological Diversity defined biological diversity as ‘the variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems’(United Nations 1992: Article 2).
- Full Text:
- Date Issued: 2021
- Authors: Isaacs, Dorelle , Olvitt, Lausanne L
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/435153 , vital:73134 , ISBN 9781928502241 , https://library.oapen.org/handle/20.500.12657/64082
- Description: This chapter shares the findings of a small-scale qualitative research project that investigated what three Grade 7 Natural Sciences teachers know, believe and say about biodiversity (Isaacs 2016). The study was sparked by the researcher’s interest in environmental learning and the importance of school curricula in preparing children to take care of their local and global environments. Biodiversity refers to Earth’s rich variety of plants and animals. It has been described as ‘the complex web of life’that includes diversity at genetic, species and ecosystem levels (Gurr et al. 2012: 4). The concept came to prominence in 1992 when the United Nations’ Convention on Biological Diversity defined biological diversity as ‘the variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems’(United Nations 1992: Article 2).
- Full Text:
- Date Issued: 2021
An exploratory study of psychologists’ perceptions of the phenomenon currently understood as ‘borderline personality disorder’
- Authors: Daya, Lekha
- Date: 2021
- Subjects: Borderline personality disorder , Psychologists -- Attitudes -- South Africa , Diagnostic and statistical manual of mental disorders
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/171139 , vital:42023
- Description: The phenomenon currently understood as ‘borderline personality disorder’ (BPD) has been complex and multifaceted since its inception. Previous studies have focused on the validity of The Diagnostic and Statistical Manual of Mental Disorders (DSM) conceptualisation of BPD, aetiologies of BPD, the psychologies of persons diagnosed with BPD, and the gendered nature of BPD. This study aimed to specifically explore South African practising psychologists’ perceptions of BPD. Through thematic analysis from a constructivist, post-modern paradigm, this study aimed to explore the perceptions and experiences of practising psychologists on BPD, as well as the usefulness of the DSM in working with BPD in a non-western society such as South Africa (SA). The study sampled two Counselling and two Clinical psychologists practising in the South African context, with exposure to and experience in working with BPD. Collectively, results in this study identified psychologists’ perceptions of shortcomings in the usefulness of the DSM’s approach to categorising phenomena associated with BPD, and brought attention to a need for further research and attention into the role of psychologists’ in the construction of BPD. This study seeks to represent psychologists’ practical experiences and perceptions, in an attempt to add contextually relevant findings on the DSM’s construction of BPD, and to contribute to challenging the stigma and misunderstanding associated with BPD. Specific practice implications and recommendations for future research are discussed within.
- Full Text:
- Date Issued: 2021
- Authors: Daya, Lekha
- Date: 2021
- Subjects: Borderline personality disorder , Psychologists -- Attitudes -- South Africa , Diagnostic and statistical manual of mental disorders
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/171139 , vital:42023
- Description: The phenomenon currently understood as ‘borderline personality disorder’ (BPD) has been complex and multifaceted since its inception. Previous studies have focused on the validity of The Diagnostic and Statistical Manual of Mental Disorders (DSM) conceptualisation of BPD, aetiologies of BPD, the psychologies of persons diagnosed with BPD, and the gendered nature of BPD. This study aimed to specifically explore South African practising psychologists’ perceptions of BPD. Through thematic analysis from a constructivist, post-modern paradigm, this study aimed to explore the perceptions and experiences of practising psychologists on BPD, as well as the usefulness of the DSM in working with BPD in a non-western society such as South Africa (SA). The study sampled two Counselling and two Clinical psychologists practising in the South African context, with exposure to and experience in working with BPD. Collectively, results in this study identified psychologists’ perceptions of shortcomings in the usefulness of the DSM’s approach to categorising phenomena associated with BPD, and brought attention to a need for further research and attention into the role of psychologists’ in the construction of BPD. This study seeks to represent psychologists’ practical experiences and perceptions, in an attempt to add contextually relevant findings on the DSM’s construction of BPD, and to contribute to challenging the stigma and misunderstanding associated with BPD. Specific practice implications and recommendations for future research are discussed within.
- Full Text:
- Date Issued: 2021
An introduction to the fourth decadal review of biological control of invasive alien plants in South Africa (2011–2020)
- Paterson, Iain D, den Breeyen, Alana, Martin, Grant D, Olckers, Tamryn
- Authors: Paterson, Iain D , den Breeyen, Alana , Martin, Grant D , Olckers, Tamryn
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/413387 , vital:71031 , xlink:href="https://hdl.handle.net/10520/ejc-ento_v29_n3_a2"
- Description: This special issue is the fourth decadal review of biological control of invasive alien plants (biocontrol of weeds) in South Africa, following those published in 1991, 1999 and 2011. Including this introduction, there are 24 papers covering the weed biocontrol programmes, or important developments in the science and practice, from the period 2011-2020. Seventy-two target weed species are covered, including 25 species on which projects were initiated during the past decade. Developments in regulations, mass-rearing and implementation, and community engagement are also reviewed. An updated catalogue of agents released, rejected and under consideration is presented and reflects the most recent methods of quantifying success in weed biocontrol. Key events over the last decade include the hosting of the XIV International Symposium on Biological Control of Weeds to celebrate 100 years of weed biocontrol in South Africa, as well as the establishment of the Centre for Biological Control at Rhodes University. The science and practice of weed biocontrol has expanded significantly in the past decade, with growth in the number of researchers and practitioners, increased funding, and an increased number of scholarly outputs. Unlike many other countries in the world, South Africa has largely avoided constraints due to restrictive and risk averse legislation and bureaucracy, and has continued to release new biocontrol agents at a similar rate to that in previous years. Much of the success of weed biocontrol in South Africa is due to the sustained and increasing support of the Natural Resource Management Programme of the Department of Forestry, Fisheries and the Environment (Working for Water Programme). However, gaps in funding, where no funds are available for months at a time, are a major concern as the weed biocontrol community loses human capital in these periods, and research programmes suffer significant set-backs. Weed biocontrol is an essential component of South Africa’s strategy to reduce the negative impacts of invasive alien plants and has contributed significantly towards the protection of the country’s ecosystems, indigenous biodiversity, water security, agricultural productivity, and society in general. If the trend of increasing support for weed biocontrol in South Africa continues, we can expect that the benefits for the country at large will increase substantially in the future.
- Full Text:
- Date Issued: 2021
- Authors: Paterson, Iain D , den Breeyen, Alana , Martin, Grant D , Olckers, Tamryn
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/413387 , vital:71031 , xlink:href="https://hdl.handle.net/10520/ejc-ento_v29_n3_a2"
- Description: This special issue is the fourth decadal review of biological control of invasive alien plants (biocontrol of weeds) in South Africa, following those published in 1991, 1999 and 2011. Including this introduction, there are 24 papers covering the weed biocontrol programmes, or important developments in the science and practice, from the period 2011-2020. Seventy-two target weed species are covered, including 25 species on which projects were initiated during the past decade. Developments in regulations, mass-rearing and implementation, and community engagement are also reviewed. An updated catalogue of agents released, rejected and under consideration is presented and reflects the most recent methods of quantifying success in weed biocontrol. Key events over the last decade include the hosting of the XIV International Symposium on Biological Control of Weeds to celebrate 100 years of weed biocontrol in South Africa, as well as the establishment of the Centre for Biological Control at Rhodes University. The science and practice of weed biocontrol has expanded significantly in the past decade, with growth in the number of researchers and practitioners, increased funding, and an increased number of scholarly outputs. Unlike many other countries in the world, South Africa has largely avoided constraints due to restrictive and risk averse legislation and bureaucracy, and has continued to release new biocontrol agents at a similar rate to that in previous years. Much of the success of weed biocontrol in South Africa is due to the sustained and increasing support of the Natural Resource Management Programme of the Department of Forestry, Fisheries and the Environment (Working for Water Programme). However, gaps in funding, where no funds are available for months at a time, are a major concern as the weed biocontrol community loses human capital in these periods, and research programmes suffer significant set-backs. Weed biocontrol is an essential component of South Africa’s strategy to reduce the negative impacts of invasive alien plants and has contributed significantly towards the protection of the country’s ecosystems, indigenous biodiversity, water security, agricultural productivity, and society in general. If the trend of increasing support for weed biocontrol in South Africa continues, we can expect that the benefits for the country at large will increase substantially in the future.
- Full Text:
- Date Issued: 2021
An online information security Aaareness model: the disclosure of personal data
- Authors: Parker, Heather Joubert
- Date: 2021
- Subjects: Social media -- Psychological aspects , Social media -- Psychological aspects -- South Africa , Human behavior , Disclosure of information -- Psychological aspects -- Case studies , Personal information management -- Psychological aspects -- Case studies , Data protection -- Psychologial aspects -- Case studies
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/172329 , vital:42189
- Description: Social media has revolutionized the way people send and receive information by creating a new level of interconnected communication. However, the use of the Internet and social media brings about various ways in which a user’s personal data can be put at risk. This study aims to investigate what drives the disclosure of personal information online and whether an increase in awareness of the value of personal information motivates users to safeguard their information. Fourteen university students participated in a mixed-methods experiment, where they completed a questionnaire before and after being shown the data stored about them by online platforms to determine if changes occur in their intention to disclose. Following completing the initial questionnaire, the participant viewed the personal data stored about them by Facebook, Google, and Instagram. Other online tools such as Social Profile Checker, Facebook View As, and HaveIBeenPawned were used to see the information publicly available about each participant. Together these findings were discussed in a semi-structured interview to determine the influence of attitudes, subjective norms, and awareness on the cost-benefit analysis users conduct when disclosing information online. Overall, the findings indicate that users are able to disregard their concerns due to a resigned and apathetic attitude towards privacy. Furthermore, subjective norms enhanced by FOMO further allow users to overlook potential risks to their information in order to avoid social isolation and sanction. Alternatively, an increased awareness of the personal value of information and having experienced a previous privacy violation encourage the protection of information and limited disclosure. Thus, this study provides insight into privacy and information disclosure on social media in South Africa. It reveals more insight into the cost-benefit analysis users conduct by combining the Theory of Planned Behaviour with the Privacy Calculus Model, as well as the antecedent factors of Trust in the Social Media Provider, FOMO, and Personal Valuation of Information.
- Full Text:
- Date Issued: 2021
- Authors: Parker, Heather Joubert
- Date: 2021
- Subjects: Social media -- Psychological aspects , Social media -- Psychological aspects -- South Africa , Human behavior , Disclosure of information -- Psychological aspects -- Case studies , Personal information management -- Psychological aspects -- Case studies , Data protection -- Psychologial aspects -- Case studies
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/172329 , vital:42189
- Description: Social media has revolutionized the way people send and receive information by creating a new level of interconnected communication. However, the use of the Internet and social media brings about various ways in which a user’s personal data can be put at risk. This study aims to investigate what drives the disclosure of personal information online and whether an increase in awareness of the value of personal information motivates users to safeguard their information. Fourteen university students participated in a mixed-methods experiment, where they completed a questionnaire before and after being shown the data stored about them by online platforms to determine if changes occur in their intention to disclose. Following completing the initial questionnaire, the participant viewed the personal data stored about them by Facebook, Google, and Instagram. Other online tools such as Social Profile Checker, Facebook View As, and HaveIBeenPawned were used to see the information publicly available about each participant. Together these findings were discussed in a semi-structured interview to determine the influence of attitudes, subjective norms, and awareness on the cost-benefit analysis users conduct when disclosing information online. Overall, the findings indicate that users are able to disregard their concerns due to a resigned and apathetic attitude towards privacy. Furthermore, subjective norms enhanced by FOMO further allow users to overlook potential risks to their information in order to avoid social isolation and sanction. Alternatively, an increased awareness of the personal value of information and having experienced a previous privacy violation encourage the protection of information and limited disclosure. Thus, this study provides insight into privacy and information disclosure on social media in South Africa. It reveals more insight into the cost-benefit analysis users conduct by combining the Theory of Planned Behaviour with the Privacy Calculus Model, as well as the antecedent factors of Trust in the Social Media Provider, FOMO, and Personal Valuation of Information.
- Full Text:
- Date Issued: 2021
Anti-oxidant and cytotoxicity activity against the HCC70 Breast cancer cell line of aqueous and methanolic extracts of two red algae species from the Eastern Cape Coast, South Africa
- Authors: Basera, Afra Tsitsi
- Date: 2021
- Subjects: Drug resistance in cancer cells , Oxidative stress
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22589 , vital:52586
- Description: Cancer, despite extensive research, remains one of the leading causes of mortality. Research into plant-derived compounds has gained traction, as some are not cytotoxic towards healthy cells and pose fewer side effects. Marine algae produce secondary metabolites, protecting them from oxidative stress, which causes cardiovascular diseases, cancer, and diabetes. Therefore, this study aimed to evaluate the anticancer potential of selected red algae species, collected from Humewood Beach, Gqeberha in South Africa, against HCC70 (human breast adenocarcinoma) cancer cells. Identification of the species was made through DNA barcoding of the rbcL gene. Methanolic and aqueous extracts of Gelidium pristoides and Laurencia natalensis were evaluated for antioxidant activity, phytochemical content, and anticancer potential. The phytochemical composition was determined using the phenol, flavonoid, flavonol, tannin, and proanthocyanidin content assays. Antioxidant potential was evaluated using the Ferric reducing antioxidant potential, Diphenyl-1- Picrylhydrazyl (DPPH), nitric oxide, 2, 2’-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging activity, and total antioxidant capacity (TAC) assays. The resazurin assay was used to determine the antiproliferative and cytotoxic activity of the methanolic extracts and solid-phase extraction fractions against the HCC70 breast cancer cells. The red algae species were identified as G. pristoides and L. natalensis. The aqueous extract of G. pristoides exhibited significantly higher phenols (24.0 mg/g GAE), tannins (31.6 mg/g TAE), and flavonols content (20.5 mg/g RE) than its methanolic extract, or the aqueous and methanolic extracts of L. natalensis. Methanolic extracts of G. pristoides and L. natalensis exhibited significantly higher proanthocyanidin contents (19.4 mg/g and 15.7 mg/g CE) than their respective aqueous extracts (13.0 mg/g and 11.8 mg/g CE). Flavonoids, however, were absent in both species. The aqueous and methanol extracts of Laurencia natalensis and Gelidium pristoides exhibited low inhibitory activities (less than 50%) against DPPH, ABTS, and nitric oxide radicals. Both species also showed low ferric reducing power. All the extracts were antiproliferative and cytotoxic against the HCC70 breast cancer cells, with L. natalensis exhibiting more significant inhibitory activity. However, its Solid Phase Extraction fractions did not display antiproliferative potential, unlike fraction 4 of G. pristoides. The study results suggest that both G. pristoides and L. natalensis possess bioactive compounds with potential anticancer activity. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021
- Authors: Basera, Afra Tsitsi
- Date: 2021
- Subjects: Drug resistance in cancer cells , Oxidative stress
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22589 , vital:52586
- Description: Cancer, despite extensive research, remains one of the leading causes of mortality. Research into plant-derived compounds has gained traction, as some are not cytotoxic towards healthy cells and pose fewer side effects. Marine algae produce secondary metabolites, protecting them from oxidative stress, which causes cardiovascular diseases, cancer, and diabetes. Therefore, this study aimed to evaluate the anticancer potential of selected red algae species, collected from Humewood Beach, Gqeberha in South Africa, against HCC70 (human breast adenocarcinoma) cancer cells. Identification of the species was made through DNA barcoding of the rbcL gene. Methanolic and aqueous extracts of Gelidium pristoides and Laurencia natalensis were evaluated for antioxidant activity, phytochemical content, and anticancer potential. The phytochemical composition was determined using the phenol, flavonoid, flavonol, tannin, and proanthocyanidin content assays. Antioxidant potential was evaluated using the Ferric reducing antioxidant potential, Diphenyl-1- Picrylhydrazyl (DPPH), nitric oxide, 2, 2’-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging activity, and total antioxidant capacity (TAC) assays. The resazurin assay was used to determine the antiproliferative and cytotoxic activity of the methanolic extracts and solid-phase extraction fractions against the HCC70 breast cancer cells. The red algae species were identified as G. pristoides and L. natalensis. The aqueous extract of G. pristoides exhibited significantly higher phenols (24.0 mg/g GAE), tannins (31.6 mg/g TAE), and flavonols content (20.5 mg/g RE) than its methanolic extract, or the aqueous and methanolic extracts of L. natalensis. Methanolic extracts of G. pristoides and L. natalensis exhibited significantly higher proanthocyanidin contents (19.4 mg/g and 15.7 mg/g CE) than their respective aqueous extracts (13.0 mg/g and 11.8 mg/g CE). Flavonoids, however, were absent in both species. The aqueous and methanol extracts of Laurencia natalensis and Gelidium pristoides exhibited low inhibitory activities (less than 50%) against DPPH, ABTS, and nitric oxide radicals. Both species also showed low ferric reducing power. All the extracts were antiproliferative and cytotoxic against the HCC70 breast cancer cells, with L. natalensis exhibiting more significant inhibitory activity. However, its Solid Phase Extraction fractions did not display antiproliferative potential, unlike fraction 4 of G. pristoides. The study results suggest that both G. pristoides and L. natalensis possess bioactive compounds with potential anticancer activity. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021
Antiviral drug discovery: preparing for the next pandemic
- Adamson, Catherine S, Chibale, Kelly, Goss, Rebecca J M, Jaspars, Marcel, Newman, David J, Dorrington, Rosemary A
- Authors: Adamson, Catherine S , Chibale, Kelly , Goss, Rebecca J M , Jaspars, Marcel , Newman, David J , Dorrington, Rosemary A
- Date: 2021
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/177499 , vital:42827 , DOI: 10.1039/d0cs01118e
- Description: Clinically approved antiviral drugs are currently available for only 10 of the more than 220 viruses known to infect humans. The SARS-CoV-2 outbreak has exposed the critical need for compounds that can be rapidly mobilised for the treatment of re-emerging or emerging viral diseases, while vaccine development is underway. We review the current status of antiviral therapies focusing on RNA viruses, highlighting strategies for antiviral drug discovery and discuss the challenges, solutions and options to accelerate drug discovery efforts.
- Full Text:
- Date Issued: 2021
- Authors: Adamson, Catherine S , Chibale, Kelly , Goss, Rebecca J M , Jaspars, Marcel , Newman, David J , Dorrington, Rosemary A
- Date: 2021
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/177499 , vital:42827 , DOI: 10.1039/d0cs01118e
- Description: Clinically approved antiviral drugs are currently available for only 10 of the more than 220 viruses known to infect humans. The SARS-CoV-2 outbreak has exposed the critical need for compounds that can be rapidly mobilised for the treatment of re-emerging or emerging viral diseases, while vaccine development is underway. We review the current status of antiviral therapies focusing on RNA viruses, highlighting strategies for antiviral drug discovery and discuss the challenges, solutions and options to accelerate drug discovery efforts.
- Full Text:
- Date Issued: 2021
Assisting Learners to Take Up Agency in Problem-Solving Activities
- Lambrechts, Therese, O’Donoghue, Rob B, Schudel, Ingrid J
- Authors: Lambrechts, Therese , O’Donoghue, Rob B , Schudel, Ingrid J
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/435099 , vital:73130 , ISBN 9781928502241 , https://library.oapen.org/handle/20.500.12657/64082
- Description: The study was informed by an expansion of the ‘design research’ reported by McKenny and Reeves (2012) and it developed as a collaborative design process similar to that described by Voogt, Laferriere, Breuleux, Itow, Hickey and McKenny (2015). Voogt et al. approached design research as a successive and developing process of formative work by participants working together to design and assess a learning programme. In our case the design work was undertaken within a course-supported process of ESD design innovation among participating teachers and subject advisors.
- Full Text:
- Date Issued: 2021
- Authors: Lambrechts, Therese , O’Donoghue, Rob B , Schudel, Ingrid J
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/435099 , vital:73130 , ISBN 9781928502241 , https://library.oapen.org/handle/20.500.12657/64082
- Description: The study was informed by an expansion of the ‘design research’ reported by McKenny and Reeves (2012) and it developed as a collaborative design process similar to that described by Voogt, Laferriere, Breuleux, Itow, Hickey and McKenny (2015). Voogt et al. approached design research as a successive and developing process of formative work by participants working together to design and assess a learning programme. In our case the design work was undertaken within a course-supported process of ESD design innovation among participating teachers and subject advisors.
- Full Text:
- Date Issued: 2021
Asymmetric price transmission: an empirical analysis of the relationship between UG-2 chrome ore, charge chrome, nickel and Chinese domestic 304 stainless steel cold rolled coil
- Authors: Le Roux, Simon Petrus
- Date: 2021
- Subjects: Pricing , Chromium ores -- Prices -- South Africa , Nickel -- Prices -- South Africa , Austenitic stainless steel-- Prices -- China , Steel -- Prices -- South Africa , Non-Linear Autoregressive Distributive Lag (NARDL)
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/171336 , vital:42049
- Description: The goal of this study was to determine whether asymmetric price transmission (APT) exists between the prices of South African UG-2 Chrome ore, Charge Chrome, Nickel and Chinese Domestic 304 Stainless steel Cold Rolled Coil prices. Monthly time series data for the period January 2009 to July 2019 was analysed. The Non-Linear Autoregressive Distributive Lag (NARDL) model was applied to test for the presence of price asymmetry between the four variables. Firstly, it was observed that the four variables are cointegrated in the long-run. Secondly, no evidence of price asymmetry was found to be present within the Stainless steel supply chain. The reason for this is most likely due to the extremely close-knit and highly concentrated nature of this industry at each level within the supply chain. The industry can be very opaque to external observers even though the distribution of pricing information is very efficient for participants within the industry.
- Full Text:
- Date Issued: 2021
- Authors: Le Roux, Simon Petrus
- Date: 2021
- Subjects: Pricing , Chromium ores -- Prices -- South Africa , Nickel -- Prices -- South Africa , Austenitic stainless steel-- Prices -- China , Steel -- Prices -- South Africa , Non-Linear Autoregressive Distributive Lag (NARDL)
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/171336 , vital:42049
- Description: The goal of this study was to determine whether asymmetric price transmission (APT) exists between the prices of South African UG-2 Chrome ore, Charge Chrome, Nickel and Chinese Domestic 304 Stainless steel Cold Rolled Coil prices. Monthly time series data for the period January 2009 to July 2019 was analysed. The Non-Linear Autoregressive Distributive Lag (NARDL) model was applied to test for the presence of price asymmetry between the four variables. Firstly, it was observed that the four variables are cointegrated in the long-run. Secondly, no evidence of price asymmetry was found to be present within the Stainless steel supply chain. The reason for this is most likely due to the extremely close-knit and highly concentrated nature of this industry at each level within the supply chain. The industry can be very opaque to external observers even though the distribution of pricing information is very efficient for participants within the industry.
- Full Text:
- Date Issued: 2021
Asymmetrical zinc (II) phthalocyanines cobalt tungstate nanomaterial conjugates for photodegradation of methylene blue
- Mgidlana, Sithi, Nyokong, Tebello
- Authors: Mgidlana, Sithi , Nyokong, Tebello
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184991 , vital:44314 , xlink:href="https://doi.org/10.1016/j.jphotochem.2021.113421"
- Description: Herein, we present syntheses of three asymmetrical zinc(II) phthalocyanine (ZnPc) complexes and hydrothermal synthesis of cobalt tungstate nanoparticles. The ZnPc derivatives were covalently linked to cobalt tungstate nanoparticles. Photophysical and photochemical behaviour of Pcs and nanoconjugates were investigated. The nanoconjugates generated higher triplet quantum yield and singlet oxygen quantum yield than the ZnPcs alone. Furthermore, in this paper photocatalytic efficiencies of ZnPc complexes and nanoconjugates were investigated for the degradation of methylene blue and higher photocatalytic behaviour was observed for the conjugates. The kinetic model was used to study photocatalytic behaviour of all the prepared photocatalysts.
- Full Text:
- Date Issued: 2021
- Authors: Mgidlana, Sithi , Nyokong, Tebello
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184991 , vital:44314 , xlink:href="https://doi.org/10.1016/j.jphotochem.2021.113421"
- Description: Herein, we present syntheses of three asymmetrical zinc(II) phthalocyanine (ZnPc) complexes and hydrothermal synthesis of cobalt tungstate nanoparticles. The ZnPc derivatives were covalently linked to cobalt tungstate nanoparticles. Photophysical and photochemical behaviour of Pcs and nanoconjugates were investigated. The nanoconjugates generated higher triplet quantum yield and singlet oxygen quantum yield than the ZnPcs alone. Furthermore, in this paper photocatalytic efficiencies of ZnPc complexes and nanoconjugates were investigated for the degradation of methylene blue and higher photocatalytic behaviour was observed for the conjugates. The kinetic model was used to study photocatalytic behaviour of all the prepared photocatalysts.
- Full Text:
- Date Issued: 2021
Attitudes and preferences towards elements of formal and informal public green spaces in two South African towns
- Manyani, Amanda, Shackleton, Charlie M, Cocks, Michelle
- Authors: Manyani, Amanda , Shackleton, Charlie M , Cocks, Michelle
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/402203 , vital:69830 , xlink:href="https://doi.org/10.1016/j.landurbplan.2021.104147"
- Description: Different types of public urban green spaces (PUGS) contain various natural (such as trees, pools, flowerbeds) and artificial elements (such as benches, play equipment, fountains) which contribute to the enjoyment and experience of users. However, which elements users most require, appreciate or notice has rarely been examined as the basis of their choice for specific PUGS, especially in poorer neighbourhoods and countries, where formal PUGS may be limited. The study was carried out in two towns in the Eastern Cape province of South Africa, both characterized by high poverty and unemployment levels, low literacy rates and many people living without basic infrastructure and services. To understand the meanings people, have for specific PUGS elements, formal and informal PUGS and peri-urban municipal commonages were assessed with respect to the natural and artificial elements present. A survey of 360 households was conducted across two towns by targeting PUGS users and households within 100 m from the designated PUGS. Approximately 63% of the respondents visited PUGS, with informal PUGS being the most frequented. However, they were strong negative feelings towards some natural elements because of their unkempt nature. Issues of safety, cultural restrictions and lack of recreational facilities were mentioned as some of the specific deterrents against visiting the closest PUGS among different user and age groups. Most respondents emphasized the need for PUGS that are well laid out with maintained lawns, recreational facilities and open vegetation. Thus, the current design and available features within the studied PUGS do not meet local preferences and needs and thus do not contribute to enjoyment as much as they could. Attention needs to be given to understand and incorporate the elements that invoke positive attitudes among urban residents.
- Full Text:
- Date Issued: 2021
- Authors: Manyani, Amanda , Shackleton, Charlie M , Cocks, Michelle
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/402203 , vital:69830 , xlink:href="https://doi.org/10.1016/j.landurbplan.2021.104147"
- Description: Different types of public urban green spaces (PUGS) contain various natural (such as trees, pools, flowerbeds) and artificial elements (such as benches, play equipment, fountains) which contribute to the enjoyment and experience of users. However, which elements users most require, appreciate or notice has rarely been examined as the basis of their choice for specific PUGS, especially in poorer neighbourhoods and countries, where formal PUGS may be limited. The study was carried out in two towns in the Eastern Cape province of South Africa, both characterized by high poverty and unemployment levels, low literacy rates and many people living without basic infrastructure and services. To understand the meanings people, have for specific PUGS elements, formal and informal PUGS and peri-urban municipal commonages were assessed with respect to the natural and artificial elements present. A survey of 360 households was conducted across two towns by targeting PUGS users and households within 100 m from the designated PUGS. Approximately 63% of the respondents visited PUGS, with informal PUGS being the most frequented. However, they were strong negative feelings towards some natural elements because of their unkempt nature. Issues of safety, cultural restrictions and lack of recreational facilities were mentioned as some of the specific deterrents against visiting the closest PUGS among different user and age groups. Most respondents emphasized the need for PUGS that are well laid out with maintained lawns, recreational facilities and open vegetation. Thus, the current design and available features within the studied PUGS do not meet local preferences and needs and thus do not contribute to enjoyment as much as they could. Attention needs to be given to understand and incorporate the elements that invoke positive attitudes among urban residents.
- Full Text:
- Date Issued: 2021
Ball-type phthalocyanines and reduced graphene oxide nanoparticles as separate and combined corrosion inhibitors of aluminium in HCl
- Nnaji, Nnaemeka, Nawji, Njemuwa, Mack, John, Nyokong, Tebello
- Authors: Nnaji, Nnaemeka , Nawji, Njemuwa , Mack, John , Nyokong, Tebello
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185421 , vital:44385 , xlink:href="https://doi.org/10.1016/j.molstruc.2021.130279"
- Description: Corrosion inhibition performances and adsorption behaviour at the aluminum-HCl solution interface were investigated for reduced graphene oxide nanosheets (rGONS), tetrakis-[4,4′-((4-(benzo[d]thiazol-2-yl)-1,2-bis(phenoxy)] (diphthalocyaninato gallium (III) chloride) (2) and tetrakis-4-(hexadecane-1,2-dioxyl)-bis(phthalocyaninato gallium(III) chloride) (1). Corrosion inhibition effects of rGONS, 1 and 2 were evaluated alone and in combination in 1.0 M hydrochloric acid solution using electrochemical techniques. The mechanism of aluminum corrosion inhibition revealed predominantly anodic character for rGONS and predominantly cathodic character for 1, 2, and conjugates with rGONS . The polarization technique gave inhibition efficiency values of 96.5% and 96.9% respectively for 1 and 2, which increased in the presence of rGONS to 97.4% and 98.1%, respectively, for the highest concentrations of 1 and 2. Scanning electron microscopy revealed effective metal surface protection by the inhibitors by formation of protective films.
- Full Text:
- Date Issued: 2021
- Authors: Nnaji, Nnaemeka , Nawji, Njemuwa , Mack, John , Nyokong, Tebello
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185421 , vital:44385 , xlink:href="https://doi.org/10.1016/j.molstruc.2021.130279"
- Description: Corrosion inhibition performances and adsorption behaviour at the aluminum-HCl solution interface were investigated for reduced graphene oxide nanosheets (rGONS), tetrakis-[4,4′-((4-(benzo[d]thiazol-2-yl)-1,2-bis(phenoxy)] (diphthalocyaninato gallium (III) chloride) (2) and tetrakis-4-(hexadecane-1,2-dioxyl)-bis(phthalocyaninato gallium(III) chloride) (1). Corrosion inhibition effects of rGONS, 1 and 2 were evaluated alone and in combination in 1.0 M hydrochloric acid solution using electrochemical techniques. The mechanism of aluminum corrosion inhibition revealed predominantly anodic character for rGONS and predominantly cathodic character for 1, 2, and conjugates with rGONS . The polarization technique gave inhibition efficiency values of 96.5% and 96.9% respectively for 1 and 2, which increased in the presence of rGONS to 97.4% and 98.1%, respectively, for the highest concentrations of 1 and 2. Scanning electron microscopy revealed effective metal surface protection by the inhibitors by formation of protective films.
- Full Text:
- Date Issued: 2021
Barriers to access second-trimester abortion: A case report
- Authors: Ramprakash Kaswa
- Date: 2021
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/3330 , vital:43314 , https://doi.org/10.4102/safp.v63i1.5028
- Description: Despite the implementation of the Choice on Termination of Pregnancy (CTOP) Act, many women continue to procure illegal abortions in South Africa. A lack of knowledge of the CTOP Act and poor access to legal abortion in public health facilities is a big challenge. In the scope of the CTOP Act, the termination of pregnancy is a time-restricted health service, and women presented to a health care facility in the second trimester have encounter more obstacles to access the services. Keywords: Abortion; termination of pregnancy; CTOP Act; Illegal; Second Trimester.
- Full Text:
- Date Issued: 2021
- Authors: Ramprakash Kaswa
- Date: 2021
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/3330 , vital:43314 , https://doi.org/10.4102/safp.v63i1.5028
- Description: Despite the implementation of the Choice on Termination of Pregnancy (CTOP) Act, many women continue to procure illegal abortions in South Africa. A lack of knowledge of the CTOP Act and poor access to legal abortion in public health facilities is a big challenge. In the scope of the CTOP Act, the termination of pregnancy is a time-restricted health service, and women presented to a health care facility in the second trimester have encounter more obstacles to access the services. Keywords: Abortion; termination of pregnancy; CTOP Act; Illegal; Second Trimester.
- Full Text:
- Date Issued: 2021
Barriers to Implementing Information Communication Technology (ICT) in Managing Small to Medium Tourism Enterprises (SMTEs): the Case of Hogsback, Eastern Cape, South Africa
- Authors: Mxunyelwa,Siyabonga
- Date: 2021
- Subjects: Hogsback, South Africa Small and medium-sized enterprises Small Business Information Communication Technology (ICT) Computer File
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6031 , vital:45083 , https://www.ijicc.net/images/Vol_15/Iss_10/151057_Mxunyelwa_2021_E_R.pdf
- Description: Information Communication Technology is recognised worldwide for its contribution towardsSMTEs development and the economy. However, the level of ICT implementation as a management tool, its contribution and the extent of benefits on SMTEs is a debateable phenomenon. The purpose of this study was to investigate the barriers to the implementation of ICT within the context of small and medium tourism enterprises in Hogsback. Both quantitative and qualitative research methods were applied in this study. Questionnaire interviews were conducted with owner/managers in Hogsback. The stratified sampling methodwas utilised to collect data. The study indicates that (46.2%) of the business respondents wereoperating the accommodation establishments. The findings of the study underscores that (25.6%) of the business owners identified the barriers of ICT appears to be high costs. Further(23.1%) stated that accessing technology was also an impediment. Moreover, the study elucidates that (94.9%) of the SMTE concur that implementation ICT as a management tool helps to meet objectives of the business for the daily operations of the business. It is therefore recommended that ICT be implemented as a management tool for small and medium tourism enterprises. Furthermore, the study recommends that the managers/owners should invest in technology to ensure the success of the SMTEs in all aspects. Furthermore, the study serves asthe basis for future studies in the area of ICT within the SMTE sector
- Full Text:
- Date Issued: 2021
- Authors: Mxunyelwa,Siyabonga
- Date: 2021
- Subjects: Hogsback, South Africa Small and medium-sized enterprises Small Business Information Communication Technology (ICT) Computer File
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6031 , vital:45083 , https://www.ijicc.net/images/Vol_15/Iss_10/151057_Mxunyelwa_2021_E_R.pdf
- Description: Information Communication Technology is recognised worldwide for its contribution towardsSMTEs development and the economy. However, the level of ICT implementation as a management tool, its contribution and the extent of benefits on SMTEs is a debateable phenomenon. The purpose of this study was to investigate the barriers to the implementation of ICT within the context of small and medium tourism enterprises in Hogsback. Both quantitative and qualitative research methods were applied in this study. Questionnaire interviews were conducted with owner/managers in Hogsback. The stratified sampling methodwas utilised to collect data. The study indicates that (46.2%) of the business respondents wereoperating the accommodation establishments. The findings of the study underscores that (25.6%) of the business owners identified the barriers of ICT appears to be high costs. Further(23.1%) stated that accessing technology was also an impediment. Moreover, the study elucidates that (94.9%) of the SMTE concur that implementation ICT as a management tool helps to meet objectives of the business for the daily operations of the business. It is therefore recommended that ICT be implemented as a management tool for small and medium tourism enterprises. Furthermore, the study recommends that the managers/owners should invest in technology to ensure the success of the SMTEs in all aspects. Furthermore, the study serves asthe basis for future studies in the area of ICT within the SMTE sector
- Full Text:
- Date Issued: 2021
Biological control of cactaceae in South Africa
- Paterson, Iain D, Klein, Hildegard, Muskett, Phillippa C, Griffith, Tamzin C, Mayonde, Samalesu, Mofokeng, Kedibone, Mnqeta, Zezethu, Venter, Nic
- Authors: Paterson, Iain D , Klein, Hildegard , Muskett, Phillippa C , Griffith, Tamzin C , Mayonde, Samalesu , Mofokeng, Kedibone , Mnqeta, Zezethu , Venter, Nic
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/${Handle} , vital:71034 , xlink:href="https://hdl.handle.net/10520/ejc-ento_v29_n3_a4"
- Description: Cactaceae are among the most problematic invasive alien plants in South Africa, posing serious negative consequences to agriculture and natural ecosystems. Fortunately, South Africa has a long and successful history of controlling cactus weeds using biological control (biocontrol). This paper reviews all the biocontrol programmes against invasive alien Cactaceae in South Africa, focusing on the decade since the last review published in 2011, up to, and including 2020. Biocontrol programmes against 16 target weeds are summarised, all of which rely on either the galling mealybug, Hypogeococcus sp. (Pseudococcidae), or various species or intraspecific lineages of cochineal insects (Dactylopius spp., Dactylopiidae) as agents. New agents are being considered for the three target weed species, Opuntia elata Salm-Dyck, Opuntia megapotamica Arechav. and Trichocereus spachianus (Lem.) Riccob., while permission to release a new agent against Cylindropuntia pallida (Rose) F.M. Knuth has recently been granted. The biocontrol agent, Dactylopius opuntiae (Cockrell) ‘stricta’, which has been utilised for the successful control of Opuntia stricta Haw., has shown some promise as an agent against one of the worst cactus weeds in the country, the North Cape/Free State variety of Opuntia engelmannii Salm-Dyck. Post-release monitoring and recent observations of the status of control for the 11 other cactus weeds, all of which have well-established agents, are provided. Taxonomic uncertainties and misidentifications of both target weeds and agents has been a constraint to biocontrol efforts, but this has been partially overcome through the use of genetic techniques. Biocontrol is particularly successful in controlling cactus weeds compared to most other taxonomic groups, and it is likely that past successes can be repeated with new target weeds. Mass-rearing and redistribution of agents are essential to gain the maximum possible benefit from cactus biocontrol agents, and recent increases in mass-rearing outputs have been beneficial.
- Full Text:
- Date Issued: 2021
- Authors: Paterson, Iain D , Klein, Hildegard , Muskett, Phillippa C , Griffith, Tamzin C , Mayonde, Samalesu , Mofokeng, Kedibone , Mnqeta, Zezethu , Venter, Nic
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/${Handle} , vital:71034 , xlink:href="https://hdl.handle.net/10520/ejc-ento_v29_n3_a4"
- Description: Cactaceae are among the most problematic invasive alien plants in South Africa, posing serious negative consequences to agriculture and natural ecosystems. Fortunately, South Africa has a long and successful history of controlling cactus weeds using biological control (biocontrol). This paper reviews all the biocontrol programmes against invasive alien Cactaceae in South Africa, focusing on the decade since the last review published in 2011, up to, and including 2020. Biocontrol programmes against 16 target weeds are summarised, all of which rely on either the galling mealybug, Hypogeococcus sp. (Pseudococcidae), or various species or intraspecific lineages of cochineal insects (Dactylopius spp., Dactylopiidae) as agents. New agents are being considered for the three target weed species, Opuntia elata Salm-Dyck, Opuntia megapotamica Arechav. and Trichocereus spachianus (Lem.) Riccob., while permission to release a new agent against Cylindropuntia pallida (Rose) F.M. Knuth has recently been granted. The biocontrol agent, Dactylopius opuntiae (Cockrell) ‘stricta’, which has been utilised for the successful control of Opuntia stricta Haw., has shown some promise as an agent against one of the worst cactus weeds in the country, the North Cape/Free State variety of Opuntia engelmannii Salm-Dyck. Post-release monitoring and recent observations of the status of control for the 11 other cactus weeds, all of which have well-established agents, are provided. Taxonomic uncertainties and misidentifications of both target weeds and agents has been a constraint to biocontrol efforts, but this has been partially overcome through the use of genetic techniques. Biocontrol is particularly successful in controlling cactus weeds compared to most other taxonomic groups, and it is likely that past successes can be repeated with new target weeds. Mass-rearing and redistribution of agents are essential to gain the maximum possible benefit from cactus biocontrol agents, and recent increases in mass-rearing outputs have been beneficial.
- Full Text:
- Date Issued: 2021
Biological control of invasive climbing plants in South Africa
- King, Anthony M, Paterson, Iain D, Simelane, David O, Mawela, Khethani V, Mngeta, Zezethu
- Authors: King, Anthony M , Paterson, Iain D , Simelane, David O , Mawela, Khethani V , Mngeta, Zezethu
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/413471 , vital:71041 , xlink:href="https://hdl.handle.net/10520/ejc-ento_v29_n3_a17"
- Description: Vines and other climbing plants typically invest their resources into growth at the expense of accumulating self-supporting biomass. Adaptive traits that have arisen because of the life history needs of climbing species, such as rapid and extensive growth, as well as resilience to physical damage, make these plants highly competitive. Introduced climbing species therefore have the potential to be particularly damaging in novel ranges where they escape pressure from natural enemies. In South Africa, invasive climbing species negatively influence biodiversity and plant-community structure, and as conventional management is often difficult, biological control (biocontrol) is viewed as the only viable long-term control method. This paper consolidates the work done on biocontrol programmes against climbing species in South Africa, including Anredera cordifolia (Ten.) Steenis (Basellaceae), Cardiospermum grandiflorum Sw. (Sapindaceae), Dolichandra unguis-cati (L.) L.G.Lohmann (Bignoniaceae) and Pereskia aculeata Miller (Cactaceae). To date, these programmes have investigated some 27 potential biocontrol agents, of which nine have been approved for release in the country. Since 2010, three new agents have been introduced, and considerable progress made with post-release evaluations of all the introduced agents. Some positive results have been achieved, most notably the successful reduction in seed set of C. grandiflorum due to Cissanthonomus tuberculipennis Hustache (Curculionidae), but considerable variation in efficacy over time and between infestations has been recorded for many of the other agents. Further work may help explain the factors limiting success, leading to improved control, but in some cases, such as for A. cordifolia, new biocontrol agents should be considered.
- Full Text:
- Date Issued: 2021
- Authors: King, Anthony M , Paterson, Iain D , Simelane, David O , Mawela, Khethani V , Mngeta, Zezethu
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/413471 , vital:71041 , xlink:href="https://hdl.handle.net/10520/ejc-ento_v29_n3_a17"
- Description: Vines and other climbing plants typically invest their resources into growth at the expense of accumulating self-supporting biomass. Adaptive traits that have arisen because of the life history needs of climbing species, such as rapid and extensive growth, as well as resilience to physical damage, make these plants highly competitive. Introduced climbing species therefore have the potential to be particularly damaging in novel ranges where they escape pressure from natural enemies. In South Africa, invasive climbing species negatively influence biodiversity and plant-community structure, and as conventional management is often difficult, biological control (biocontrol) is viewed as the only viable long-term control method. This paper consolidates the work done on biocontrol programmes against climbing species in South Africa, including Anredera cordifolia (Ten.) Steenis (Basellaceae), Cardiospermum grandiflorum Sw. (Sapindaceae), Dolichandra unguis-cati (L.) L.G.Lohmann (Bignoniaceae) and Pereskia aculeata Miller (Cactaceae). To date, these programmes have investigated some 27 potential biocontrol agents, of which nine have been approved for release in the country. Since 2010, three new agents have been introduced, and considerable progress made with post-release evaluations of all the introduced agents. Some positive results have been achieved, most notably the successful reduction in seed set of C. grandiflorum due to Cissanthonomus tuberculipennis Hustache (Curculionidae), but considerable variation in efficacy over time and between infestations has been recorded for many of the other agents. Further work may help explain the factors limiting success, leading to improved control, but in some cases, such as for A. cordifolia, new biocontrol agents should be considered.
- Full Text:
- Date Issued: 2021
Biological control of South African plants that are invasive elsewhere in the world: A review of earlier and current programmes
- Olckers, Terence, Coetzee, Julie A, Egli, Daniella, Martin, Grant D, Paterson, Iain D, Sutton, Guy F, Wood, Alan
- Authors: Olckers, Terence , Coetzee, Julie A , Egli, Daniella , Martin, Grant D , Paterson, Iain D , Sutton, Guy F , Wood, Alan
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/414336 , vital:71137 , xlink:href="https://hdl.handle.net/10520/ejc-ento_v29_n3_a21"
- Description: South Africa supports a rich floral diversity, with 21 643 native plant taxa that include a high proportion (76.3%) of endemic species, and many of these favoured as ornamentals, both locally and globally. Consequently, South Africa has contributed substantially to global plant invasions, with 1093 native taxa (5% of all species) naturalized in other countries. At least 80 taxa are invasive in natural or semi-natural ecosystems elsewhere, while an additional 132 taxa are potentially invasive. Of the global naturalized flora, 8.2% originate from South Africa and largely comprise species of Poaceae, Asteraceae, Iridaceae and Fabaceae. Australia, in particular, but also Europe and North America are major recipients of South African weeds. However, few countries have targeted South African plants for biological control (biocontrol), with most efforts undertaken by Australia. Previous and current targets have involved only 26 species with 17 agents (15 insects, one mite and one rust fungus) of South African origin released on five target species in Australia and the United States of America. South Africa’s history of weed biocontrol, together with a large cohort of active scientists, is currently facilitating several internationally funded programmes targeting invasive plants of South African origin. In particular, the recently inaugurated Centre for Biological Control at Rhodes University and the University of KwaZulu-Natal have provided the impetus for novel efforts on five new target species and renewed efforts on four previously targeted species. In this contribution, we review the history of earlier biocontrol programmes against weeds of South African origin and the status of projects currently in progress in South Africa.
- Full Text:
- Date Issued: 2021
- Authors: Olckers, Terence , Coetzee, Julie A , Egli, Daniella , Martin, Grant D , Paterson, Iain D , Sutton, Guy F , Wood, Alan
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/414336 , vital:71137 , xlink:href="https://hdl.handle.net/10520/ejc-ento_v29_n3_a21"
- Description: South Africa supports a rich floral diversity, with 21 643 native plant taxa that include a high proportion (76.3%) of endemic species, and many of these favoured as ornamentals, both locally and globally. Consequently, South Africa has contributed substantially to global plant invasions, with 1093 native taxa (5% of all species) naturalized in other countries. At least 80 taxa are invasive in natural or semi-natural ecosystems elsewhere, while an additional 132 taxa are potentially invasive. Of the global naturalized flora, 8.2% originate from South Africa and largely comprise species of Poaceae, Asteraceae, Iridaceae and Fabaceae. Australia, in particular, but also Europe and North America are major recipients of South African weeds. However, few countries have targeted South African plants for biological control (biocontrol), with most efforts undertaken by Australia. Previous and current targets have involved only 26 species with 17 agents (15 insects, one mite and one rust fungus) of South African origin released on five target species in Australia and the United States of America. South Africa’s history of weed biocontrol, together with a large cohort of active scientists, is currently facilitating several internationally funded programmes targeting invasive plants of South African origin. In particular, the recently inaugurated Centre for Biological Control at Rhodes University and the University of KwaZulu-Natal have provided the impetus for novel efforts on five new target species and renewed efforts on four previously targeted species. In this contribution, we review the history of earlier biocontrol programmes against weeds of South African origin and the status of projects currently in progress in South Africa.
- Full Text:
- Date Issued: 2021
Book Review Quinn, L.(ed.) 2019. Re-imagining Curriculum: Spaces for Disruption
- Authors: McKenna, Sioux
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185865 , vital:44441 , xlink:href="https://journals.co.za/doi/abs/10.14426/cristal.v9i1.434"
- Description: This book is in some ways a continuation of the conversation begun with Reimaging Academic Staff Development: Spaces for Disruption (2012), also edited by Lynn Quinn. But the 2019 volume takes a much wider viewpoint including, as it does, twenty chapters by forty-two authors who are academics and academic developers across institutional types from Australia, Canada, South Africa, the United States of America, the United Kingdom, and the West Indies. Quinn and Vorster (2019: 2) state in Chapter One that the purpose of the book is 'to share theoretical perspectives and practical ideas for ways in which academic developers (and academic leaders) can work in partnership with lecturers and students to respond to the urgent calls for curriculum transformation and decolonisation'. This captures the four threads that run throughout the collection.
- Full Text:
- Date Issued: 2021
- Authors: McKenna, Sioux
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185865 , vital:44441 , xlink:href="https://journals.co.za/doi/abs/10.14426/cristal.v9i1.434"
- Description: This book is in some ways a continuation of the conversation begun with Reimaging Academic Staff Development: Spaces for Disruption (2012), also edited by Lynn Quinn. But the 2019 volume takes a much wider viewpoint including, as it does, twenty chapters by forty-two authors who are academics and academic developers across institutional types from Australia, Canada, South Africa, the United States of America, the United Kingdom, and the West Indies. Quinn and Vorster (2019: 2) state in Chapter One that the purpose of the book is 'to share theoretical perspectives and practical ideas for ways in which academic developers (and academic leaders) can work in partnership with lecturers and students to respond to the urgent calls for curriculum transformation and decolonisation'. This captures the four threads that run throughout the collection.
- Full Text:
- Date Issued: 2021
Borneol-triarylcorrole hybrids with chiral-optical response and anticancer behaviours
- Fu, Bo, Wang, Lin, Yu, Xiaoxiao, Fang, Xianying, Mack, John, Dingiswayo, Somila, Nyokong, Tebello, Liang, Xu, Xu, Haijun
- Authors: Fu, Bo , Wang, Lin , Yu, Xiaoxiao , Fang, Xianying , Mack, John , Dingiswayo, Somila , Nyokong, Tebello , Liang, Xu , Xu, Haijun
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185294 , vital:44362 , xlink:href="https://doi.org/10.1016/j.dyepig.2021.109699"
- Description: A series of four multifunctional A2B type H3corroles with meso-borneol substituents at the B position have been synthesized and characterized. A detailed analysis of the optical properties was carried out, and a comparison was made with theoretical calculations to identify the key trends in the structure-property relationships. The meso-borneol substituent couples with the corrole core leading to clear CD signals in the B band region. Enhanced anti-cancer properties are observed in vitro relative to (−)-borneol with cell inhibition rates of up to 94%.
- Full Text:
- Date Issued: 2021
- Authors: Fu, Bo , Wang, Lin , Yu, Xiaoxiao , Fang, Xianying , Mack, John , Dingiswayo, Somila , Nyokong, Tebello , Liang, Xu , Xu, Haijun
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185294 , vital:44362 , xlink:href="https://doi.org/10.1016/j.dyepig.2021.109699"
- Description: A series of four multifunctional A2B type H3corroles with meso-borneol substituents at the B position have been synthesized and characterized. A detailed analysis of the optical properties was carried out, and a comparison was made with theoretical calculations to identify the key trends in the structure-property relationships. The meso-borneol substituent couples with the corrole core leading to clear CD signals in the B band region. Enhanced anti-cancer properties are observed in vitro relative to (−)-borneol with cell inhibition rates of up to 94%.
- Full Text:
- Date Issued: 2021