A critical review of sanctioned knowledge production concerning abortion in Africa: Implications for feminist health psychology
- Macleod, Catriona I, Chiweshe, Malvern T, Mavuso, Jabulile M-J J
- Authors: Macleod, Catriona I , Chiweshe, Malvern T , Mavuso, Jabulile M-J J
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444212 , vital:74207 , xlink:href="https://doi.org/10.1177/1359105316644294"
- Description: Taking a feminist health psychology approach, we conducted a systematic review of published research on abortion featured in PsycINFO over a 7-year period. We analysed the 39 articles included in the review in terms of countries in which the research was conducted, types of research, issues covered, the way the research was framed and main findings. Despite 97per cent of abortions performed in Africa being classifiable as unsafe, there has been no engagement in knowledge production about abortion in Africa from psychologists, outside of South Africa. Given this, we outline the implications of the current knowledge base for feminism, psychology and feminist health psychology in Africa.
- Full Text:
- Date Issued: 2018
- Authors: Macleod, Catriona I , Chiweshe, Malvern T , Mavuso, Jabulile M-J J
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444212 , vital:74207 , xlink:href="https://doi.org/10.1177/1359105316644294"
- Description: Taking a feminist health psychology approach, we conducted a systematic review of published research on abortion featured in PsycINFO over a 7-year period. We analysed the 39 articles included in the review in terms of countries in which the research was conducted, types of research, issues covered, the way the research was framed and main findings. Despite 97per cent of abortions performed in Africa being classifiable as unsafe, there has been no engagement in knowledge production about abortion in Africa from psychologists, outside of South Africa. Given this, we outline the implications of the current knowledge base for feminism, psychology and feminist health psychology in Africa.
- Full Text:
- Date Issued: 2018
A return to common-sense: why ecology needs transcendental realism
- Authors: Price, Leigh
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/390324 , vital:68538 , xlink:href="https://doi.org/10.1080/14767430.2019.1580178"
- Description: Empirical realist ecologists, such as C. S. Holling, face significant methodological contradictions; for instance, they must cope with the problem that ecological models and theories of climate change, resilience and succession cannot make predictions in open systems. Generally, they respond to this problem by supplementing their empirical realism with transcendental idealism: they therefore say that their models are simply metaphorical or heuristic, that is, 'not true' in that they are not empirical. Thus, they explicitly deny an ontology for what their models are about. Nevertheless, in their practice, ecologists act as if their theories do have an ontology and thus tell us something truthful about the real world. This discrepancy leaves ecology vulnerable to unnecessary critique, such as that climate science is not real science. Transcendental realism offers a solution because it releases ecologists from the requirement to make predictions; but it does so without denying ontology. This provides several advantages to ecologists.
- Full Text:
- Date Issued: 2019
- Authors: Price, Leigh
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/390324 , vital:68538 , xlink:href="https://doi.org/10.1080/14767430.2019.1580178"
- Description: Empirical realist ecologists, such as C. S. Holling, face significant methodological contradictions; for instance, they must cope with the problem that ecological models and theories of climate change, resilience and succession cannot make predictions in open systems. Generally, they respond to this problem by supplementing their empirical realism with transcendental idealism: they therefore say that their models are simply metaphorical or heuristic, that is, 'not true' in that they are not empirical. Thus, they explicitly deny an ontology for what their models are about. Nevertheless, in their practice, ecologists act as if their theories do have an ontology and thus tell us something truthful about the real world. This discrepancy leaves ecology vulnerable to unnecessary critique, such as that climate science is not real science. Transcendental realism offers a solution because it releases ecologists from the requirement to make predictions; but it does so without denying ontology. This provides several advantages to ecologists.
- Full Text:
- Date Issued: 2019
Actor/actant-network theory as emerging methodology for environmental education research in southern Africa
- Authors: Nhamo, Godwell
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/373553 , vital:66701 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122722"
- Description: This paper deliberates on actor/actant-network theory (AANT) as methodology for policy research in environmental education (EE). Insights are drawn from work that applied AANT to research environmental policy processes surrounding the formulation and implementation of South Africa’s Plastic Bags Regulations of 2003. The paper reveals that the application of AANT methodology made it possible to trace relationships, actors, actants and actor/actant-networks surrounding the Plastic Bags Regulations as quasi-object (token). The methodology also enabled a focus on understanding and investigating tensions, debates and responses emerging from the policy process. The findings were that after the promulgation of the first draft of the Plastic Bags Regulations in May 2000, tensions emerged around the nature of regulation (whether to use the command and control approach – preferred by Organised Government – or self regulation – preferred by Organised Business and Organised Labour). From these findings, a series of conceptual frameworks were drawn up as identified around key actors and actor/actant-networks. The conceptual frameworks included among them, Organised Government, Organised Business and Organised Labour.
- Full Text: false
- Date Issued: 2006
- Authors: Nhamo, Godwell
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/373553 , vital:66701 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122722"
- Description: This paper deliberates on actor/actant-network theory (AANT) as methodology for policy research in environmental education (EE). Insights are drawn from work that applied AANT to research environmental policy processes surrounding the formulation and implementation of South Africa’s Plastic Bags Regulations of 2003. The paper reveals that the application of AANT methodology made it possible to trace relationships, actors, actants and actor/actant-networks surrounding the Plastic Bags Regulations as quasi-object (token). The methodology also enabled a focus on understanding and investigating tensions, debates and responses emerging from the policy process. The findings were that after the promulgation of the first draft of the Plastic Bags Regulations in May 2000, tensions emerged around the nature of regulation (whether to use the command and control approach – preferred by Organised Government – or self regulation – preferred by Organised Business and Organised Labour). From these findings, a series of conceptual frameworks were drawn up as identified around key actors and actor/actant-networks. The conceptual frameworks included among them, Organised Government, Organised Business and Organised Labour.
- Full Text: false
- Date Issued: 2006
Actor/actant-network theory as emerging methodology for environmental education research in southern Africa
- Authors: Nhamo, Godwell
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/373537 , vital:66702 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122722"
- Description: This paper deliberates on actor/actant-network theory (AANT) as methodology for policy research in environmental education (EE). Insights are drawn from work that applied AANT to research environmental policy processes surrounding the formulation and implementation of South Africa’s Plastic Bags Regulations of 2003. The paper reveals that the application of AANT methodology made it possible to trace relationships, actors, actants and actor/actant-networks surrounding the Plastic Bags Regulations as quasi-object (token). The methodology also enabled a focus on understanding and investigating tensions, debates and responses emerging from the policy process. The findings were that after the promulgation of the first draft of the Plastic Bags Regulations in May 2000, tensions emerged around the nature of regulation (whether to use the command and control approach – preferred by Organised Government – or self regulation – preferred by Organised Business and Organised Labour). From these findings, a series of conceptual frameworks were drawn up as identified around key actors and actor/actant-networks. The conceptual frameworks included among them, Organised Government, Organised Business and Organised Labour.
- Full Text:
- Date Issued: 2006
- Authors: Nhamo, Godwell
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/373537 , vital:66702 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122722"
- Description: This paper deliberates on actor/actant-network theory (AANT) as methodology for policy research in environmental education (EE). Insights are drawn from work that applied AANT to research environmental policy processes surrounding the formulation and implementation of South Africa’s Plastic Bags Regulations of 2003. The paper reveals that the application of AANT methodology made it possible to trace relationships, actors, actants and actor/actant-networks surrounding the Plastic Bags Regulations as quasi-object (token). The methodology also enabled a focus on understanding and investigating tensions, debates and responses emerging from the policy process. The findings were that after the promulgation of the first draft of the Plastic Bags Regulations in May 2000, tensions emerged around the nature of regulation (whether to use the command and control approach – preferred by Organised Government – or self regulation – preferred by Organised Business and Organised Labour). From these findings, a series of conceptual frameworks were drawn up as identified around key actors and actor/actant-networks. The conceptual frameworks included among them, Organised Government, Organised Business and Organised Labour.
- Full Text:
- Date Issued: 2006
Adaptation and validation of a computerized neurocognitive battery in the Xhosa of South Africa
- Cobb, Scott J, Moore, Tyler M, Stein, Dan J, Pretorius, Adele, Zingela, Zukiswa, Nagdee, Mohammed, Ngqengelele, Linda, Campbell, Megan M, Sibeko, Goodman, King, Mary C, McClellan, Jon M, Port, Allison M, Jackson, Chad, Ruparel, Kosha, Susser, Ezra, Gur, Ruben C
- Authors: Cobb, Scott J , Moore, Tyler M , Stein, Dan J , Pretorius, Adele , Zingela, Zukiswa , Nagdee, Mohammed , Ngqengelele, Linda , Campbell, Megan M , Sibeko, Goodman , King, Mary C , McClellan, Jon M , Port, Allison M , Jackson, Chad , Ruparel, Kosha , Susser, Ezra , Gur, Ruben C
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/302439 , vital:58196 , xlink:href="https://doi.org/10.1037/neu0000742"
- Description: Objective: Large-scale studies have revolutionized biomedical research, and neurocognitive tests can help elucidate the biological basis of neuropsychiatric diseases. However, studies have predominantly been conducted in Western settings. We describe the development and validation of a computerized battery (PennCNB) with the Xhosa population of South Africa. Method: Individuals with schizophrenia (n = 525) and a normative comparison group (n = 744) were balanced on age, sex, education, and region. Participants provided blood samples, were assessed psychiatrically, and were administered a PennCNB translation to isiXhosa, including measures of executive functions, episodic memory, complex cognition, social cognition, and sensorimotor speed. Feasibility was examined with test completion rates and input from administrators, and psychometric structural validity and associations with clinical and demographic characteristics were examined. Results: Tests were well tolerated by participants, as >87% had one (or fewer) test missing. Results suggested a similar factor structure to prior PennCNB studies in Western contexts, and expected age and sex effects were apparent. Furthermore, a similar profile of schizophrenia was observed, with neurocognitive deficits most pronounced for executive functions, especially attention, as well as memory, social cognition, and motor speed relative to complex cognition and sensorimotor speed. Conclusions: Results support the feasibility of implementing a culturally adapted computerized neurocognitive battery in sub-Saharan African settings and provide evidence supporting the concurrent validity of the translated instrument. Thus, the PennCNB is implementable on a large scale in non-Western contexts, shows expected factor structure, and can detect cognitive deficits associated with neuropsychiatric disorders. Obtaining valid measures of cognition by nonspecialized proctors is especially suitable in resource-limited settings, where traditional testing is prohibitive. Future work should establish normative standards, test–retest reliability, and sensitivity to treatment.
- Full Text:
- Date Issued: 2021
- Authors: Cobb, Scott J , Moore, Tyler M , Stein, Dan J , Pretorius, Adele , Zingela, Zukiswa , Nagdee, Mohammed , Ngqengelele, Linda , Campbell, Megan M , Sibeko, Goodman , King, Mary C , McClellan, Jon M , Port, Allison M , Jackson, Chad , Ruparel, Kosha , Susser, Ezra , Gur, Ruben C
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/302439 , vital:58196 , xlink:href="https://doi.org/10.1037/neu0000742"
- Description: Objective: Large-scale studies have revolutionized biomedical research, and neurocognitive tests can help elucidate the biological basis of neuropsychiatric diseases. However, studies have predominantly been conducted in Western settings. We describe the development and validation of a computerized battery (PennCNB) with the Xhosa population of South Africa. Method: Individuals with schizophrenia (n = 525) and a normative comparison group (n = 744) were balanced on age, sex, education, and region. Participants provided blood samples, were assessed psychiatrically, and were administered a PennCNB translation to isiXhosa, including measures of executive functions, episodic memory, complex cognition, social cognition, and sensorimotor speed. Feasibility was examined with test completion rates and input from administrators, and psychometric structural validity and associations with clinical and demographic characteristics were examined. Results: Tests were well tolerated by participants, as >87% had one (or fewer) test missing. Results suggested a similar factor structure to prior PennCNB studies in Western contexts, and expected age and sex effects were apparent. Furthermore, a similar profile of schizophrenia was observed, with neurocognitive deficits most pronounced for executive functions, especially attention, as well as memory, social cognition, and motor speed relative to complex cognition and sensorimotor speed. Conclusions: Results support the feasibility of implementing a culturally adapted computerized neurocognitive battery in sub-Saharan African settings and provide evidence supporting the concurrent validity of the translated instrument. Thus, the PennCNB is implementable on a large scale in non-Western contexts, shows expected factor structure, and can detect cognitive deficits associated with neuropsychiatric disorders. Obtaining valid measures of cognition by nonspecialized proctors is especially suitable in resource-limited settings, where traditional testing is prohibitive. Future work should establish normative standards, test–retest reliability, and sensitivity to treatment.
- Full Text:
- Date Issued: 2021
Aluminum corrosion retardation properties of acetamidophenoxy phthalocyanines: Effect of central metal
- Nnaji, Nnaemeka, Sen, Pinar, Nyokong, Tebello
- Authors: Nnaji, Nnaemeka , Sen, Pinar , Nyokong, Tebello
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185433 , vital:44386 , xlink:href="https://doi.org/10.1016/j.molstruc.2021.130806"
- Description: Corrosion inhibition performances and adsorption behaviour at the aluminum-HCl solution interface were investigated for metal free (2), ClGa (3) and Co (4) tetrakis (4-acetamidophenoxy) phthalocyanine. Electrochemical techniques were used in the study and complemented with Fourier transform infrared, scanning electron microscopy and X-ray diffraction measurements. Potentiodynamic polarization technique gave inhibition efficiency values as 93.3% (2), 69.7% (3) and 87.7% (4) at 28°C at highest inhibitor concentration (10 µM) in the following order 2 > 4 > 3. These compounds exhibited good corrosion inhibition performance as mixed-type corrosion inhibitors. All applied techniques gave results which corroborated.
- Full Text:
- Date Issued: 2021
- Authors: Nnaji, Nnaemeka , Sen, Pinar , Nyokong, Tebello
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185433 , vital:44386 , xlink:href="https://doi.org/10.1016/j.molstruc.2021.130806"
- Description: Corrosion inhibition performances and adsorption behaviour at the aluminum-HCl solution interface were investigated for metal free (2), ClGa (3) and Co (4) tetrakis (4-acetamidophenoxy) phthalocyanine. Electrochemical techniques were used in the study and complemented with Fourier transform infrared, scanning electron microscopy and X-ray diffraction measurements. Potentiodynamic polarization technique gave inhibition efficiency values as 93.3% (2), 69.7% (3) and 87.7% (4) at 28°C at highest inhibitor concentration (10 µM) in the following order 2 > 4 > 3. These compounds exhibited good corrosion inhibition performance as mixed-type corrosion inhibitors. All applied techniques gave results which corroborated.
- Full Text:
- Date Issued: 2021
An investigation of face and fingerprint feature-fusion guidelines
- Brown, Dane L, Bradshaw, Karen L
- Authors: Brown, Dane L , Bradshaw, Karen L
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/473751 , vital:77678 , xlink:href="https://doi.org/10.1007/978-3-319-34099-9_45"
- Description: There are a lack of multi-modal biometric fusion guidelines at the feature-level. This paper investigates face and fingerprint features in the form of their strengths and weaknesses. This serves as a set of guidelines to authors that are planning face and fingerprint feature-fusion applications or aim to extend this into a general framework. The proposed guidelines were applied to the face and fingerprint to achieve a 91.11 % recognition accuracy when using only a single training sample. Furthermore, an accuracy of 99.69 % was achieved when using five training samples.
- Full Text:
- Date Issued: 2016
- Authors: Brown, Dane L , Bradshaw, Karen L
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/473751 , vital:77678 , xlink:href="https://doi.org/10.1007/978-3-319-34099-9_45"
- Description: There are a lack of multi-modal biometric fusion guidelines at the feature-level. This paper investigates face and fingerprint features in the form of their strengths and weaknesses. This serves as a set of guidelines to authors that are planning face and fingerprint feature-fusion applications or aim to extend this into a general framework. The proposed guidelines were applied to the face and fingerprint to achieve a 91.11 % recognition accuracy when using only a single training sample. Furthermore, an accuracy of 99.69 % was achieved when using five training samples.
- Full Text:
- Date Issued: 2016
Articulating reproductive justice through reparative justice: case studies of abortion in Great Britain and South Africa
- Macleod, Catriona I, Beynon-Jones, Siân, Toerien, Merran
- Authors: Macleod, Catriona I , Beynon-Jones, Siân , Toerien, Merran
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444237 , vital:74209 , xlink:href="https://doi.org/10.1080/13691058.2016.1257738"
- Description: Public health and rights-based approaches to abortion advocacy are well established. Feminists are, however, increasingly using a broader framework of ‘reproductive justice’, which considers the intersecting conditions that serve to enhance or hinder women’s reproductive freedoms, including their capacities to decide about the outcome of their pregnancies. Nonetheless, reproductive justice approaches to abortion are, conceptually, relatively under-developed. We introduce a reparative justice approach as a method of further articulating the concept of reproductive justice. We first explain how this approach can be used to conceptualise safe, accessible and supportive abortion as a key element of reproductive justice in relation to the injustice of unwanted or unsupportable pregnancies. Using Ernesto Verdeja’s critical theory of reparative justice and case studies of two countries (South Africa and Great Britain) where abortion is legal, we show how such an approach enables an analysis of reproductive justice within the specificities of particular contexts. We argue that both the rights-based legal framework adopted in South Africa and the medicalised approach of British law have, in practice, limited reparative justice in these contexts. We discuss the implications of reparative justice for abortion advocacy.
- Full Text:
- Date Issued: 2017
- Authors: Macleod, Catriona I , Beynon-Jones, Siân , Toerien, Merran
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444237 , vital:74209 , xlink:href="https://doi.org/10.1080/13691058.2016.1257738"
- Description: Public health and rights-based approaches to abortion advocacy are well established. Feminists are, however, increasingly using a broader framework of ‘reproductive justice’, which considers the intersecting conditions that serve to enhance or hinder women’s reproductive freedoms, including their capacities to decide about the outcome of their pregnancies. Nonetheless, reproductive justice approaches to abortion are, conceptually, relatively under-developed. We introduce a reparative justice approach as a method of further articulating the concept of reproductive justice. We first explain how this approach can be used to conceptualise safe, accessible and supportive abortion as a key element of reproductive justice in relation to the injustice of unwanted or unsupportable pregnancies. Using Ernesto Verdeja’s critical theory of reparative justice and case studies of two countries (South Africa and Great Britain) where abortion is legal, we show how such an approach enables an analysis of reproductive justice within the specificities of particular contexts. We argue that both the rights-based legal framework adopted in South Africa and the medicalised approach of British law have, in practice, limited reparative justice in these contexts. We discuss the implications of reparative justice for abortion advocacy.
- Full Text:
- Date Issued: 2017
Assessment of spatial variation in carbon utilization by benthic and pelagic invertebrates in a temperate South African estuary using stable isotope signatures
- Richoux, Nicole B, Froneman, P William
- Authors: Richoux, Nicole B , Froneman, P William
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/457923 , vital:75695 , xlink:href="https://doi.org/10.1016/j.ecss.2006.09.007 "
- Description: Stable isotope analyses (δ13C and δ15N) were used to evaluate the spatial variations in carbon flow from primary producers to consumers at two sites in the temperate and permanently open Kariega Estuary on the southeastern coast of South Africa during October 2005 and February 2006. One site was located opposite a salt marsh while the second was upstream of the marsh. Except for significantly enriched δ13C values of Zostera capensis and surface sediments near the salt marsh, the δ13C and δ15N signatures of the producers were similar between sites. The invertebrates were clustered into groups roughly corresponding to the predominant feeding modes. The suspension feeders showed δ13C values closest to the seston, whereas the deposit feeders, detritivores and scavengers/predators had more enriched δ13C values reflecting primary carbon sources that were likely a combination of seston, Spartina maritima and Z. capensis at the upstream site, with an increased influence of benthic algae and Z. capensis at the salt marsh site. The δ15N signatures of the consumers showed a stepwise continuum rather than distinct levels of fractionation, indicating highly complex trophic linkages and significant dietary overlap among the species. Consumers exhibited significantly enriched δ13C values at the salt marsh site, an effect that was attributed to enriched Z. capensis detritus in this region in addition to increased phytoplankton biomass in their diets compared with invertebrates living upstream. The data reinforce the concept that between-site variations in the stable isotope ratios of consumers can result not only from dietary shifts, but also from alterations in the isotope ratios of primary producers.
- Full Text:
- Date Issued: 2007
- Authors: Richoux, Nicole B , Froneman, P William
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/457923 , vital:75695 , xlink:href="https://doi.org/10.1016/j.ecss.2006.09.007 "
- Description: Stable isotope analyses (δ13C and δ15N) were used to evaluate the spatial variations in carbon flow from primary producers to consumers at two sites in the temperate and permanently open Kariega Estuary on the southeastern coast of South Africa during October 2005 and February 2006. One site was located opposite a salt marsh while the second was upstream of the marsh. Except for significantly enriched δ13C values of Zostera capensis and surface sediments near the salt marsh, the δ13C and δ15N signatures of the producers were similar between sites. The invertebrates were clustered into groups roughly corresponding to the predominant feeding modes. The suspension feeders showed δ13C values closest to the seston, whereas the deposit feeders, detritivores and scavengers/predators had more enriched δ13C values reflecting primary carbon sources that were likely a combination of seston, Spartina maritima and Z. capensis at the upstream site, with an increased influence of benthic algae and Z. capensis at the salt marsh site. The δ15N signatures of the consumers showed a stepwise continuum rather than distinct levels of fractionation, indicating highly complex trophic linkages and significant dietary overlap among the species. Consumers exhibited significantly enriched δ13C values at the salt marsh site, an effect that was attributed to enriched Z. capensis detritus in this region in addition to increased phytoplankton biomass in their diets compared with invertebrates living upstream. The data reinforce the concept that between-site variations in the stable isotope ratios of consumers can result not only from dietary shifts, but also from alterations in the isotope ratios of primary producers.
- Full Text:
- Date Issued: 2007
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
Axial coordination of zinc and silicon phthalocyanines to silver and gold nanoparticles: an investigation of their photophysicochemical and antimicrobial behavior
- Masilela, Nkosiphile, Antunes, Edith M, Nyokong, Tebello
- Authors: Masilela, Nkosiphile , Antunes, Edith M , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241818 , vital:50972 , xlink:href="https://doi.org/10.1142/S1088424613500016"
- Description: This work reports on the axial coordination of zinc phthalocyanine and bis-(1,6-hexanedithiol) silicon phthalocyanine to silver and gold nanoparticles. Red shifting of absorption spectra of the phthalocyanine complexes was observed after conjugation with the nanoparticles. An improvement in the photophysicochemical behavior and antimicrobial activity was achieved in the presence of metal nanoparticles for both complexes. A decrease in triplet lifetimes was observed for all the phthalocyanine metal nanoparticle conjugates. The Zn phthalocyanine complex gave the highest triplet and singlet oxygen quantum yield in the presence of gold nanoparticles. On the other hand, the bacterial inhibition was found to be best for the Si phthalocyanine derivative in the presence of nanoparticles compared to the Zn phthalocyanine counterpart. The highest antimicrobial activity was achieved for both conjugates against B. subtilis compared to S. aureaus both in the dark and under illumination with light.
- Full Text:
- Date Issued: 2013
- Authors: Masilela, Nkosiphile , Antunes, Edith M , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241818 , vital:50972 , xlink:href="https://doi.org/10.1142/S1088424613500016"
- Description: This work reports on the axial coordination of zinc phthalocyanine and bis-(1,6-hexanedithiol) silicon phthalocyanine to silver and gold nanoparticles. Red shifting of absorption spectra of the phthalocyanine complexes was observed after conjugation with the nanoparticles. An improvement in the photophysicochemical behavior and antimicrobial activity was achieved in the presence of metal nanoparticles for both complexes. A decrease in triplet lifetimes was observed for all the phthalocyanine metal nanoparticle conjugates. The Zn phthalocyanine complex gave the highest triplet and singlet oxygen quantum yield in the presence of gold nanoparticles. On the other hand, the bacterial inhibition was found to be best for the Si phthalocyanine derivative in the presence of nanoparticles compared to the Zn phthalocyanine counterpart. The highest antimicrobial activity was achieved for both conjugates against B. subtilis compared to S. aureaus both in the dark and under illumination with light.
- Full Text:
- Date Issued: 2013
Battle of the large carnivores: spatial partitioning in a small, enclosed reserve?
- Comley, Jessica, Joubert, Christoffel J, Mgqatsa, Nokubonga, Parker, Daniel M
- Authors: Comley, Jessica , Joubert, Christoffel J , Mgqatsa, Nokubonga , Parker, Daniel M
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/462581 , vital:76316 , xlink:href="https://hdl.handle.net/10520/EJC-2037326828"
- Description: Interspecific competition among terrestrial carnivores can have widespread impacts on community structure and can ultimately determine which species are able to coexist. Within the carnivore guild, coexistence can be achieved through either spatial, temporal or dietary partitioning. The most effective method of avoiding competition may be spatial partitioning, as it removes the potential for negative interactions. The ways in which large carnivore species utilize and partition space in small, enclosed reserves in South Africa is currently poorly understood. This knowledge gap weakens our understanding of which mechanisms structure large carnivore communities in these systems. Thus, our aim was to use Global Positioning System (GPS) collars to investigate the spatial dynamics of large carnivores [four lions (Panthera leo), three leopards (Panthera pardus) and three spotted hyaenas (Crocuta crocuta)] on a small, enclosed reserve (Selati Game Reserve). Regarding home ranges, lions had considerable overlap among themselves (especially the females), leopards had minimal overlap, while spotted hyaenas had no home range overlap. Although we found no evidence for spatial partitioning amongst the collared large carnivores, differences in the habitat use patterns of the three large carnivore species is evident. The high prey abundance of Selati, carnivore predation strategies, behavioural adaptations and ecological separation could be facilitating the coexistence of lions, spotted hyaenas and leopards in Selati. We encourage future research to be aimed at investigating the interactions of multiple sympatric carnivores in an attempt to bridge the knowledge gap on which mechanisms structure carnivore communities.
- Full Text:
- Date Issued: 2020
- Authors: Comley, Jessica , Joubert, Christoffel J , Mgqatsa, Nokubonga , Parker, Daniel M
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/462581 , vital:76316 , xlink:href="https://hdl.handle.net/10520/EJC-2037326828"
- Description: Interspecific competition among terrestrial carnivores can have widespread impacts on community structure and can ultimately determine which species are able to coexist. Within the carnivore guild, coexistence can be achieved through either spatial, temporal or dietary partitioning. The most effective method of avoiding competition may be spatial partitioning, as it removes the potential for negative interactions. The ways in which large carnivore species utilize and partition space in small, enclosed reserves in South Africa is currently poorly understood. This knowledge gap weakens our understanding of which mechanisms structure large carnivore communities in these systems. Thus, our aim was to use Global Positioning System (GPS) collars to investigate the spatial dynamics of large carnivores [four lions (Panthera leo), three leopards (Panthera pardus) and three spotted hyaenas (Crocuta crocuta)] on a small, enclosed reserve (Selati Game Reserve). Regarding home ranges, lions had considerable overlap among themselves (especially the females), leopards had minimal overlap, while spotted hyaenas had no home range overlap. Although we found no evidence for spatial partitioning amongst the collared large carnivores, differences in the habitat use patterns of the three large carnivore species is evident. The high prey abundance of Selati, carnivore predation strategies, behavioural adaptations and ecological separation could be facilitating the coexistence of lions, spotted hyaenas and leopards in Selati. We encourage future research to be aimed at investigating the interactions of multiple sympatric carnivores in an attempt to bridge the knowledge gap on which mechanisms structure carnivore communities.
- Full Text:
- Date Issued: 2020
Challenges of information and communication technology policy implementation in rural South Africa
- Chisango, Grasia, Lesame, Carol
- Authors: Chisango, Grasia , Lesame, Carol
- Date: 2017
- Subjects: Information society , Digital inclusion , Education
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/5592 , vital:44611 , https://doi.org/10.18820/24150525/Comm.v22.4
- Description: While the South African government has implemented an information and communication technology (ICT) policy to address issues of universal access and service, questions remain about the effective implementation of this policy in rural areas. This article explores the extent to which ICT policy and regulation were implemented in rural South Africa, with specific reference to the Eastern Cape province. Focus group interviews and in-depth face-to-face interviews were conducted to collect qualitative data from 28 high school learners, two local municipal mayors and two women support group leaders in the Chris Hani District Municipality. A theme analysis indicated that the Universal Service and Access Agency of South Africa (USAASA) is failing to fulfil its mandate of promoting universal access and service. It is recommended that the provincial government in the Eastern Cape design an ICT strategy for its municipalities and that there should be easy access to Thusong Service Centres in rural areas.
- Full Text:
- Date Issued: 2017
- Authors: Chisango, Grasia , Lesame, Carol
- Date: 2017
- Subjects: Information society , Digital inclusion , Education
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/5592 , vital:44611 , https://doi.org/10.18820/24150525/Comm.v22.4
- Description: While the South African government has implemented an information and communication technology (ICT) policy to address issues of universal access and service, questions remain about the effective implementation of this policy in rural areas. This article explores the extent to which ICT policy and regulation were implemented in rural South Africa, with specific reference to the Eastern Cape province. Focus group interviews and in-depth face-to-face interviews were conducted to collect qualitative data from 28 high school learners, two local municipal mayors and two women support group leaders in the Chris Hani District Municipality. A theme analysis indicated that the Universal Service and Access Agency of South Africa (USAASA) is failing to fulfil its mandate of promoting universal access and service. It is recommended that the provincial government in the Eastern Cape design an ICT strategy for its municipalities and that there should be easy access to Thusong Service Centres in rural areas.
- Full Text:
- Date Issued: 2017
Chemical constituents, antioxidant and cytotoxicity properties of Leonotis leonurus used in the folklore management of neurological disorders in the Eastern Cape, South Africa
- Tonisi, Sipho, Okaiyeto, Kunle, Hoppe, Heinrich C, Mabinya, Leonard V, Nwodo, Uchechukwu U, Okoh, Anthony I
- Authors: Tonisi, Sipho , Okaiyeto, Kunle , Hoppe, Heinrich C , Mabinya, Leonard V , Nwodo, Uchechukwu U , Okoh, Anthony I
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429384 , vital:72606 , xlink:href="https://doi.org/10.1007/s13205-020-2126-5"
- Description: In the present study, we evaluated the phytochemical compounds and antioxidant properties of chloroform, ethanol and acetone extracts for leaves and flowers of Leonutus leonurus (L. leonurus) alongside with their cytotoxic effects on human cervical carcinoma (HeLa) cell lines. The phytochemical compounds present in the leaves and flowers of L. leonurus included; phenolics, flavonoids and alkaloids. Their radicals scavenging effects against 2, 2-diphenyl-1-picrylhydrazyl [DPPH] 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulphonate) [ABTS·+], hydrogen peroxide, nitric oxide as well as metal chelating activities showed dose-dependent activities. Gas chromatography-mass spectrometry (GCMS) analyses revealed the presence of important bioactive compounds, which are associated with antioxidant; and the extracts exhibited toxicity effect against HeLa cells. The findings from this study divulge extracts of L. leonurus as prospective sources of antioxidant and anticancer agents; and hence, further study on their neuroprotective potentials becomes imperative.
- Full Text:
- Date Issued: 2020
- Authors: Tonisi, Sipho , Okaiyeto, Kunle , Hoppe, Heinrich C , Mabinya, Leonard V , Nwodo, Uchechukwu U , Okoh, Anthony I
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429384 , vital:72606 , xlink:href="https://doi.org/10.1007/s13205-020-2126-5"
- Description: In the present study, we evaluated the phytochemical compounds and antioxidant properties of chloroform, ethanol and acetone extracts for leaves and flowers of Leonutus leonurus (L. leonurus) alongside with their cytotoxic effects on human cervical carcinoma (HeLa) cell lines. The phytochemical compounds present in the leaves and flowers of L. leonurus included; phenolics, flavonoids and alkaloids. Their radicals scavenging effects against 2, 2-diphenyl-1-picrylhydrazyl [DPPH] 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulphonate) [ABTS·+], hydrogen peroxide, nitric oxide as well as metal chelating activities showed dose-dependent activities. Gas chromatography-mass spectrometry (GCMS) analyses revealed the presence of important bioactive compounds, which are associated with antioxidant; and the extracts exhibited toxicity effect against HeLa cells. The findings from this study divulge extracts of L. leonurus as prospective sources of antioxidant and anticancer agents; and hence, further study on their neuroprotective potentials becomes imperative.
- Full Text:
- Date Issued: 2020
Cholera in KwaZulu-Natal: Probing institutional governmentality and indigenous hand-washing practices
- Authors: O'Donoghue, Rob B
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/373574 , vital:66704 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122699"
- Description: The paper reviews education activities in a successful anti-cholera campaign amongst rural communities in eastern southern Africa. It is centred on probing how a modern institutional governmentality was relatively blind to an historical legacy of Nguni hand-washing practices and came to exclude use of simple tests for coliform contamination in rural health education activities. The study examines institutional processes, probing discontinuities between the health education message and the complex social ecology of cholera. In so doing, it uncovers how a post-apartheid institutional rhetoric of participation, empowerment and social transformation is playing out in communicative interventions to instil healthier practices amongst the rural poor. Institutional perspectives such as this are rooted in an institutional legacy of appropriation and control. Despite the current rhetoric of participation, instrumental orientations are being sustained as the radical critique of struggle for freedom and change gives way, through comfortable submission and intellectual conformity, to an instrumental conservatism in many post-apartheid institutional settings today. The study notes and probes a surprising resonance between the ecology of the disease and an intergenerational social capital of indigenous hand-washing practices. The evidence suggests that these patterns of hand-washing practice would have served to contain the disease in earlier times and points to this social capital as a focus for co-engaged action on environment and health concerns. The findings suggest that an opposing of institutional and indigenous knowledge is not a simple matter and that moving beyond a legacy of cultural exclusion and marginalisation remains a challenge as the first decade of post-apartheid democratic governance comes to a close.
- Full Text:
- Date Issued: 2005
- Authors: O'Donoghue, Rob B
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/373574 , vital:66704 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122699"
- Description: The paper reviews education activities in a successful anti-cholera campaign amongst rural communities in eastern southern Africa. It is centred on probing how a modern institutional governmentality was relatively blind to an historical legacy of Nguni hand-washing practices and came to exclude use of simple tests for coliform contamination in rural health education activities. The study examines institutional processes, probing discontinuities between the health education message and the complex social ecology of cholera. In so doing, it uncovers how a post-apartheid institutional rhetoric of participation, empowerment and social transformation is playing out in communicative interventions to instil healthier practices amongst the rural poor. Institutional perspectives such as this are rooted in an institutional legacy of appropriation and control. Despite the current rhetoric of participation, instrumental orientations are being sustained as the radical critique of struggle for freedom and change gives way, through comfortable submission and intellectual conformity, to an instrumental conservatism in many post-apartheid institutional settings today. The study notes and probes a surprising resonance between the ecology of the disease and an intergenerational social capital of indigenous hand-washing practices. The evidence suggests that these patterns of hand-washing practice would have served to contain the disease in earlier times and points to this social capital as a focus for co-engaged action on environment and health concerns. The findings suggest that an opposing of institutional and indigenous knowledge is not a simple matter and that moving beyond a legacy of cultural exclusion and marginalisation remains a challenge as the first decade of post-apartheid democratic governance comes to a close.
- Full Text:
- Date Issued: 2005
Conjugation of azide-functionalised CdSe/ZnS quantum dots with tetrakis (5-hexyn-oxy) Fe (II) phthalocyanine via click chemistry for electrocatalysis
- Nxele, Siphesihle R, Nyokong, Tebello
- Authors: Nxele, Siphesihle R , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188755 , vital:44782 , xlink:href="https://doi.org/10.1016/j.electacta.2016.01.234"
- Description: In this work, azide-funtionalised CdSe/ZnS QDs are conjugated with tetrakis(5-hexyn-oxy) Fe(II) phthalocyanine for the electrocatalytic detection of paraquat. The conjugate was fully characterised using various techniques to confirm the success of the reaction. They also showed good electrocatalytic ability towards the electroreduction of paraquat with limits of detection (LoD) of 5.9 × 10−9 μM which is a great improvement compared to other reported sensors for this analyte.
- Full Text:
- Date Issued: 2016
- Authors: Nxele, Siphesihle R , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188755 , vital:44782 , xlink:href="https://doi.org/10.1016/j.electacta.2016.01.234"
- Description: In this work, azide-funtionalised CdSe/ZnS QDs are conjugated with tetrakis(5-hexyn-oxy) Fe(II) phthalocyanine for the electrocatalytic detection of paraquat. The conjugate was fully characterised using various techniques to confirm the success of the reaction. They also showed good electrocatalytic ability towards the electroreduction of paraquat with limits of detection (LoD) of 5.9 × 10−9 μM which is a great improvement compared to other reported sensors for this analyte.
- Full Text:
- Date Issued: 2016
Cordidepsine is A Potential New Anti-HIV Depsidone from Cordia millenii
- Zeukang, Rostanie D, Siwe-Noundou, Xavier, Fotsing, Maurice T, Mbafor, Joseph T, Krause, Rui W M, Choudhary, Muhammad I, Atchade, Alex de Theodore
- Authors: Zeukang, Rostanie D , Siwe-Noundou, Xavier , Fotsing, Maurice T , Mbafor, Joseph T , Krause, Rui W M , Choudhary, Muhammad I , Atchade, Alex de Theodore
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193988 , vital:45413 , xlink:href="https://doi.org/10.3390/molecules24173202"
- Description: Chemical investigation of Cordia millenii, Baker resulted in the isolation of a new depsidone, cordidepsine (1), along with twelve known compounds including cyclooctasulfur (2), lup-20(29)-en-3-triacontanoate (3), 1-(26-hydroxyhexacosanoyl)glycerol (4), glyceryl-1-hexacosanoate (5) betulinic acid (6), lupenone (7), β-amyrone (8), lupeol (9), β-amyrin (10), allantoin (11), 2′-(4-hydroxyphenyl)ethylpropanoate (12) and stigmasterol glycoside (13). Hemi-synthetic reactions were carried out on two isolated compounds (5 and 6) to afford two new derivatives, that is, cordicerol A (14) and cordicerol B (15), respectively. The chemical structures of all the compounds were established based on analysis and interpretation of spectroscopic data such as electron ionization mass spectrometry (EI–MS), high resolution electrospray ionization mass spectrometry (HR-ESI–MS), fast atom bombardment mass spectrometry (FAB–MS), one dimension and two dimension nuclear magnetic resonance (1D and 2D-NMR) spectral data as well as X-ray crystallography (XRC). Lupeol ester derivatives [Lup-20(29)-en-3-triacontanoate (3)], monoglycerol derivatives [1-(26-hydroxyhexacosanoyl)glycerol (4) and glyceryl-1 hexacosanoate (5)] were isolated for the first time from Cordia genus while sulfur allotrope [cyclooctasulfur (2)] was isolated for the first time from plant origin. Biological assays cordidepsine (1) exhibited significant anti-HIV integrase activity with IC50 = 4.65 μM; EtOAc extract of stem barks, EtOAc fraction of roots and leaves were not toxic against 3T3 cells.
- Full Text:
- Date Issued: 2019
- Authors: Zeukang, Rostanie D , Siwe-Noundou, Xavier , Fotsing, Maurice T , Mbafor, Joseph T , Krause, Rui W M , Choudhary, Muhammad I , Atchade, Alex de Theodore
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193988 , vital:45413 , xlink:href="https://doi.org/10.3390/molecules24173202"
- Description: Chemical investigation of Cordia millenii, Baker resulted in the isolation of a new depsidone, cordidepsine (1), along with twelve known compounds including cyclooctasulfur (2), lup-20(29)-en-3-triacontanoate (3), 1-(26-hydroxyhexacosanoyl)glycerol (4), glyceryl-1-hexacosanoate (5) betulinic acid (6), lupenone (7), β-amyrone (8), lupeol (9), β-amyrin (10), allantoin (11), 2′-(4-hydroxyphenyl)ethylpropanoate (12) and stigmasterol glycoside (13). Hemi-synthetic reactions were carried out on two isolated compounds (5 and 6) to afford two new derivatives, that is, cordicerol A (14) and cordicerol B (15), respectively. The chemical structures of all the compounds were established based on analysis and interpretation of spectroscopic data such as electron ionization mass spectrometry (EI–MS), high resolution electrospray ionization mass spectrometry (HR-ESI–MS), fast atom bombardment mass spectrometry (FAB–MS), one dimension and two dimension nuclear magnetic resonance (1D and 2D-NMR) spectral data as well as X-ray crystallography (XRC). Lupeol ester derivatives [Lup-20(29)-en-3-triacontanoate (3)], monoglycerol derivatives [1-(26-hydroxyhexacosanoyl)glycerol (4) and glyceryl-1 hexacosanoate (5)] were isolated for the first time from Cordia genus while sulfur allotrope [cyclooctasulfur (2)] was isolated for the first time from plant origin. Biological assays cordidepsine (1) exhibited significant anti-HIV integrase activity with IC50 = 4.65 μM; EtOAc extract of stem barks, EtOAc fraction of roots and leaves were not toxic against 3T3 cells.
- Full Text:
- Date Issued: 2019
Current and future biological control efforts against Solanum mauritianum (Solanaceae) in South Africa
- Venter, Nic, Cowie, Blair W, Olckers, Terence, Byrne, Marcus J
- Authors: Venter, Nic , Cowie, Blair W , Olckers, Terence , Byrne, Marcus J
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/414349 , vital:71138 , xlink:href="https://hdl.handle.net/10520/ejc-ento_v29_n3_a14"
- Description: Solanum mauritianum Scop. (Solanaceae), colloquially referred to as bugweed in South Africa, remains a widespread invasive tree of global significance. Although biological control (biocontrol) efforts were undertaken from 1984 -2003 in South Africa, the programme eventually only released two agents, the sap-sucking lace bug Gargaphia decoris Drake (Hemiptera: Tingidae) and flowerbud-feeding weevil Anthonomus santacruzi Hustache (Coleoptera: Curculionidae). To date, these agents have been relatively ineffective in controlling S. mauritianum, largely due to low establishment success due to climatic incompatibility in relation to the widespread distribution of S. mauritianum. This has prompted the revival of S. mauritianum biocontrol research in 2018, with the programme focused largely on sourcing additional agents from climatically suitable regions in the plant’s native range in South America. Climate matching between cooler regions of South Africa and known S. mauritianum sites in South America identified Uruguay as a promising source of new agents. Field collections in Uruguay focused mainly on Anthonomus spp. but included stem-boring and shoot-galling weevils. Low incidence in the field and difficulties in culturing candidate species temporarily precluded research into stem-boring and shoot-galling candidates, but the rearing and assessment of the flowerbud-feeding weevil Anthonomus morticinus Clark (Coleoptera: Curculionidae) is ongoing. Host-specificity testing of A. morticinus has thus far confirmed a narrow host range, suggesting it has potential as a new agent.
- Full Text:
- Date Issued: 2021
- Authors: Venter, Nic , Cowie, Blair W , Olckers, Terence , Byrne, Marcus J
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/414349 , vital:71138 , xlink:href="https://hdl.handle.net/10520/ejc-ento_v29_n3_a14"
- Description: Solanum mauritianum Scop. (Solanaceae), colloquially referred to as bugweed in South Africa, remains a widespread invasive tree of global significance. Although biological control (biocontrol) efforts were undertaken from 1984 -2003 in South Africa, the programme eventually only released two agents, the sap-sucking lace bug Gargaphia decoris Drake (Hemiptera: Tingidae) and flowerbud-feeding weevil Anthonomus santacruzi Hustache (Coleoptera: Curculionidae). To date, these agents have been relatively ineffective in controlling S. mauritianum, largely due to low establishment success due to climatic incompatibility in relation to the widespread distribution of S. mauritianum. This has prompted the revival of S. mauritianum biocontrol research in 2018, with the programme focused largely on sourcing additional agents from climatically suitable regions in the plant’s native range in South America. Climate matching between cooler regions of South Africa and known S. mauritianum sites in South America identified Uruguay as a promising source of new agents. Field collections in Uruguay focused mainly on Anthonomus spp. but included stem-boring and shoot-galling weevils. Low incidence in the field and difficulties in culturing candidate species temporarily precluded research into stem-boring and shoot-galling candidates, but the rearing and assessment of the flowerbud-feeding weevil Anthonomus morticinus Clark (Coleoptera: Curculionidae) is ongoing. Host-specificity testing of A. morticinus has thus far confirmed a narrow host range, suggesting it has potential as a new agent.
- Full Text:
- Date Issued: 2021
Deactivation of field cultivation in communal areas of South Africa: Patterns, drivers and socio-economic and ecological consequences
- Shackleton, Charlie M, Mograbi, Penelope, Drimie, Scott, Fay, Derick, Hebinck, Paul, Hoffman, Michael T, Maciejewski, Kristine, Twine, Wayne
- Authors: Shackleton, Charlie M , Mograbi, Penelope , Drimie, Scott , Fay, Derick , Hebinck, Paul , Hoffman, Michael T , Maciejewski, Kristine , Twine, Wayne
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/398210 , vital:69384 , xlink:href="https://doi.org/10.1016/j.landusepol.2019.01.009"
- Description: Smallholder production is a significant contributor to rural livelihoods and rural economies in much of the developing world. Yet, there is evidence of increasing disengagement in some regions, including southern Africa. However, there has been little consideration of the rates and the livelihood, ecological and policy implications of such. In this paper we examine previous studies on rates of deactivation of crop fields by smallholders in the communal areas of South Africa, supported by repeat photo images and case study material. Together these various methods show that it is a widespread phenomenon occurring at variable rates. Over short periods deactivation of crop fields can be balanced through some reactivation or intensification of homegardens. But over longer periods there is a net decline in the area of fields cultivated in many areas, with corresponding increases in the area of fallow land which, through time, may undergo changes towards more natural vegetation. We review the drivers of this deactivation of field cropping, and then contemplate the possible socio-economic and ecological implications at local and national scales. We show that there are numerous and profound implications that require greater understanding and policy responses.
- Full Text:
- Date Issued: 2019
- Authors: Shackleton, Charlie M , Mograbi, Penelope , Drimie, Scott , Fay, Derick , Hebinck, Paul , Hoffman, Michael T , Maciejewski, Kristine , Twine, Wayne
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/398210 , vital:69384 , xlink:href="https://doi.org/10.1016/j.landusepol.2019.01.009"
- Description: Smallholder production is a significant contributor to rural livelihoods and rural economies in much of the developing world. Yet, there is evidence of increasing disengagement in some regions, including southern Africa. However, there has been little consideration of the rates and the livelihood, ecological and policy implications of such. In this paper we examine previous studies on rates of deactivation of crop fields by smallholders in the communal areas of South Africa, supported by repeat photo images and case study material. Together these various methods show that it is a widespread phenomenon occurring at variable rates. Over short periods deactivation of crop fields can be balanced through some reactivation or intensification of homegardens. But over longer periods there is a net decline in the area of fields cultivated in many areas, with corresponding increases in the area of fallow land which, through time, may undergo changes towards more natural vegetation. We review the drivers of this deactivation of field cropping, and then contemplate the possible socio-economic and ecological implications at local and national scales. We show that there are numerous and profound implications that require greater understanding and policy responses.
- Full Text:
- Date Issued: 2019
Declines in Livestock Numbers Accompany Cropping Deagrarianisation Processes in the Eastern Cape, South Africa
- Shackleton, Charlie M, Ntshudu, Monde
- Authors: Shackleton, Charlie M , Ntshudu, Monde
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/402248 , vital:69834 , xlink:href="https://doi.org/10.3390/land12091735"
- Description: Deagrarianisation amongst smallholder farmers is a growing phenomenon globally, driven by a complex array of context-specific and higher-scale factors. Most research has focused on declines in arable cropping, with relatively little regard to the deagrarianisation dynamics associated with livestock ownership, yet the two are often linked through the need for draught power for ploughing. Here, we report on a survey of 293 rural households in 10 rural villages in the Eastern Cape province, South Africa, where we ascertained whether ownership of cattle, goats, sheep and pigs had changed over the previous 15 years and what were the underlying reasons for any changes at both village- and household-scale. The majority felt that there had been a decline in the number of households keeping livestock and the number of animals in the village. Additionally, a clear majority of owners for each type of livestock stated that their households currently have fewer animals than 15 years ago. The main reasons for declines were that their animals had died due to drought or disease, theft, or they had sold them because of financial needs. There was a positive association between the keeping of cattle and field cultivation. Despite these general declines, two-thirds of households currently without livestock wished that they had some, primarily for use in cultural ceremonies/rituals or for income. This study shows the deagrarianisation processes in the region also apply to the livestock sector despite the significance of livestock in the local Xhosa culture. This study highlights the multifaceted nature of deagrarianisation in communal tenure systems.
- Full Text:
- Date Issued: 2023
- Authors: Shackleton, Charlie M , Ntshudu, Monde
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/402248 , vital:69834 , xlink:href="https://doi.org/10.3390/land12091735"
- Description: Deagrarianisation amongst smallholder farmers is a growing phenomenon globally, driven by a complex array of context-specific and higher-scale factors. Most research has focused on declines in arable cropping, with relatively little regard to the deagrarianisation dynamics associated with livestock ownership, yet the two are often linked through the need for draught power for ploughing. Here, we report on a survey of 293 rural households in 10 rural villages in the Eastern Cape province, South Africa, where we ascertained whether ownership of cattle, goats, sheep and pigs had changed over the previous 15 years and what were the underlying reasons for any changes at both village- and household-scale. The majority felt that there had been a decline in the number of households keeping livestock and the number of animals in the village. Additionally, a clear majority of owners for each type of livestock stated that their households currently have fewer animals than 15 years ago. The main reasons for declines were that their animals had died due to drought or disease, theft, or they had sold them because of financial needs. There was a positive association between the keeping of cattle and field cultivation. Despite these general declines, two-thirds of households currently without livestock wished that they had some, primarily for use in cultural ceremonies/rituals or for income. This study shows the deagrarianisation processes in the region also apply to the livestock sector despite the significance of livestock in the local Xhosa culture. This study highlights the multifaceted nature of deagrarianisation in communal tenure systems.
- Full Text:
- Date Issued: 2023