Looking back to move forward: a scoping review of counselling psychology in South Africa
- Haine, Phillipa, Young, Charles S, Booysen, Duane D
- Authors: Haine, Phillipa , Young, Charles S , Booysen, Duane D
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/454106 , vital:75310 , xlink:href="https://doi.org/10.1177/00812463221091433"
- Description: Despite that counselling psychologists represent a substantial group of registered psychologists in South Africa, literature specifically on the sub-speciality within the country is limited. The aim of this scoping review was to provide a comprehensive summary of the literature available on counselling psychology in South Africa and examine the extent to which literature is available from a lifespan or career-stage perspective. Three electronic databases (EBSCOhost, Sabinet®, and PubMed) were searched for articles published between 2000 and 2021. Titles and abstracts were reviewed, and data extracted and synthesised thematically. Of 507 citations identified, 10 met the inclusion criteria. Findings indicate that literature on counselling psychology in South Africa is scarce, subject to methodological limitations, and dominated by a small number of authors conducting multiple analyses on the same sets of data. Furthermore, literature on counselling psychologists at key career stages across the professional lifespan is largely missing from the professional discourse. Emphasis is instead placed on counselling psychology as embedded in the sociopolitical history of South Africa, professional identity, the contemporary status of the profession, professional threats and challenges, and the profession’s future promise. Our review highlights the need for more empirically informed studies making use of different methodologies, involving multiple authors with diverse backgrounds, tracking employment trends, and soliciting first-person accounts of counselling psychologist’s experiences at key career stages. Without doing so, ideas about how best to support and utilise this particular group of practitioners may be misguided, in turn compromising the successful provision of mental health care within the country.
- Full Text:
- Authors: Haine, Phillipa , Young, Charles S , Booysen, Duane D
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/454106 , vital:75310 , xlink:href="https://doi.org/10.1177/00812463221091433"
- Description: Despite that counselling psychologists represent a substantial group of registered psychologists in South Africa, literature specifically on the sub-speciality within the country is limited. The aim of this scoping review was to provide a comprehensive summary of the literature available on counselling psychology in South Africa and examine the extent to which literature is available from a lifespan or career-stage perspective. Three electronic databases (EBSCOhost, Sabinet®, and PubMed) were searched for articles published between 2000 and 2021. Titles and abstracts were reviewed, and data extracted and synthesised thematically. Of 507 citations identified, 10 met the inclusion criteria. Findings indicate that literature on counselling psychology in South Africa is scarce, subject to methodological limitations, and dominated by a small number of authors conducting multiple analyses on the same sets of data. Furthermore, literature on counselling psychologists at key career stages across the professional lifespan is largely missing from the professional discourse. Emphasis is instead placed on counselling psychology as embedded in the sociopolitical history of South Africa, professional identity, the contemporary status of the profession, professional threats and challenges, and the profession’s future promise. Our review highlights the need for more empirically informed studies making use of different methodologies, involving multiple authors with diverse backgrounds, tracking employment trends, and soliciting first-person accounts of counselling psychologist’s experiences at key career stages. Without doing so, ideas about how best to support and utilise this particular group of practitioners may be misguided, in turn compromising the successful provision of mental health care within the country.
- Full Text:
Love at first bite? Pre-release surveys reveal a novel association between a native weevil and the invasive Nymphaea mexicana Zuccarini (Nymphaeaceae) in South Africa
- Reid, Megan K, Hill, Martin P, Coetzee, Julie A
- Authors: Reid, Megan K , Hill, Martin P , Coetzee, Julie A
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/416866 , vital:71392 , xlink:href="https://hdl.handle.net/10520/ejc-ento_v31_n1_a19"
- Description: Classical biological control aims to suppress alien invasive plant populations by introducing host-specific natural enemies from the native range. This relies on the assumption that invasive plant populations in the invaded range benefit from the release of natural enemies. Pre-release surveys in the invaded range are a useful way to determine if enemy release applies to a particular invasive alien plant, and to determine what other factors may contribute to the invasion. Similarly, pre-release surveys gather information that can be used to compare invaded sites before and after the release of biological control agents and may also identify whether natural enemies have been accidentally introduced into the country. Pre-release surveys were conducted in South Africa on the invasive Nymphaea mexicana Zuccarini (Nymphaeaceae) to gather such information about this species, for which a biological control programme is being developed. There was lower diversity and abundance of herbivores in the native range compared to South Africa, suggesting that N. mexicana does experience enemy release at most sites in South Africa. This support for the enemy release hypothesis justifies the investment in biological control for its management. However, a native weevil, Bagous longulus Gyllenhal (Coleoptera: Curculionidae), was found feeding and reproducing on N. mexicana at three sites, resulting in damage to the leaves and suggesting that a novel association has formed between these species. Bagous longulus may have potential to be distributed to sites of N. mexicana where it is not present, though further investigation is necessary to confirm if its host range is suitable for this to be a safe endeavour. With the exception of sites where B. longulus was present, leaf sizes were large and damage was low, and there is no evidence that any natural enemies have been accidentally introduced from the native range. Findings such as these emphasise the importance of conducting thorough surveys during the development of biological control programmes.
- Full Text:
- Authors: Reid, Megan K , Hill, Martin P , Coetzee, Julie A
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/416866 , vital:71392 , xlink:href="https://hdl.handle.net/10520/ejc-ento_v31_n1_a19"
- Description: Classical biological control aims to suppress alien invasive plant populations by introducing host-specific natural enemies from the native range. This relies on the assumption that invasive plant populations in the invaded range benefit from the release of natural enemies. Pre-release surveys in the invaded range are a useful way to determine if enemy release applies to a particular invasive alien plant, and to determine what other factors may contribute to the invasion. Similarly, pre-release surveys gather information that can be used to compare invaded sites before and after the release of biological control agents and may also identify whether natural enemies have been accidentally introduced into the country. Pre-release surveys were conducted in South Africa on the invasive Nymphaea mexicana Zuccarini (Nymphaeaceae) to gather such information about this species, for which a biological control programme is being developed. There was lower diversity and abundance of herbivores in the native range compared to South Africa, suggesting that N. mexicana does experience enemy release at most sites in South Africa. This support for the enemy release hypothesis justifies the investment in biological control for its management. However, a native weevil, Bagous longulus Gyllenhal (Coleoptera: Curculionidae), was found feeding and reproducing on N. mexicana at three sites, resulting in damage to the leaves and suggesting that a novel association has formed between these species. Bagous longulus may have potential to be distributed to sites of N. mexicana where it is not present, though further investigation is necessary to confirm if its host range is suitable for this to be a safe endeavour. With the exception of sites where B. longulus was present, leaf sizes were large and damage was low, and there is no evidence that any natural enemies have been accidentally introduced from the native range. Findings such as these emphasise the importance of conducting thorough surveys during the development of biological control programmes.
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Male peer talk about menstruation: Discursively bolstering hegemonic masculinities among young men in South Africa
- Macleod, Catriona I, Glover, Jonathan M, Makuse, Manase, Kelland, Lindsay, Paphitis, Sharli A
- Authors: Macleod, Catriona I , Glover, Jonathan M , Makuse, Manase , Kelland, Lindsay , Paphitis, Sharli A
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441253 , vital:73870 , xlink:href="https://doi.org/10.1080/23293691.2022.2057830"
- Description: In this paper, we show how male peer talk about menstruating women may be used to discursively bolster hegemonic masculinities and denigrate women. Focus group discussions among 37 young isiXhosa-speaking men from two South African schools were facilitated by two young men; statements garnered from a sexuality education class about menstruation conducted in the same schools were used as cues. Data were analyzed using discourse analysis. The interactive talk constructed a bifurcation: “disgusting” menstruating women versus “reasonable” non-menstruating women who abide by idealized feminine behavior and are available sexually. We argue that as the non-menstruating woman cyclically become the other (menstruating woman) in women of particular ages, the trace of disgust inhabits the signifier “woman” for these men. Menstruation also disrupted a core identity strategy of local hegemonic masculinities: virile (hetero)sexuality. Given this, discursive distancing of the self from the very topic of menstruation is necessary. Small moments of resistance to these constructions were quickly closed down, and caring masculinity emerged only in the context of negotiating sex during menstruation. Involving men in menstrual hygiene management programs may provide spaces for resistance to denigrating discourses about menstruation.
- Full Text:
- Authors: Macleod, Catriona I , Glover, Jonathan M , Makuse, Manase , Kelland, Lindsay , Paphitis, Sharli A
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441253 , vital:73870 , xlink:href="https://doi.org/10.1080/23293691.2022.2057830"
- Description: In this paper, we show how male peer talk about menstruating women may be used to discursively bolster hegemonic masculinities and denigrate women. Focus group discussions among 37 young isiXhosa-speaking men from two South African schools were facilitated by two young men; statements garnered from a sexuality education class about menstruation conducted in the same schools were used as cues. Data were analyzed using discourse analysis. The interactive talk constructed a bifurcation: “disgusting” menstruating women versus “reasonable” non-menstruating women who abide by idealized feminine behavior and are available sexually. We argue that as the non-menstruating woman cyclically become the other (menstruating woman) in women of particular ages, the trace of disgust inhabits the signifier “woman” for these men. Menstruation also disrupted a core identity strategy of local hegemonic masculinities: virile (hetero)sexuality. Given this, discursive distancing of the self from the very topic of menstruation is necessary. Small moments of resistance to these constructions were quickly closed down, and caring masculinity emerged only in the context of negotiating sex during menstruation. Involving men in menstrual hygiene management programs may provide spaces for resistance to denigrating discourses about menstruation.
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Microbial Community Responses to Alterations in Historical Fire Regimes in Montane Grasslands
- Gokul, Jarishma K, Matcher, Gwynneth F, Dames, Joanna F, Nkangala, Kuhle, Gordijn, Paul J, Barker, Nigel P
- Authors: Gokul, Jarishma K , Matcher, Gwynneth F , Dames, Joanna F , Nkangala, Kuhle , Gordijn, Paul J , Barker, Nigel P
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440366 , vital:73777 , https://doi.org/10.3390/d15070818
- Description: The influence of fire regimes on soil microbial diversity in montane grasslands is a relatively unexplored area of interest. Understanding the belowground diversity is a crucial stepping-stone toward unravelling community dynamics, nutrient sequestration, and overall ecosystem stability. In this study, metabarcoding was used to unravel the impact of fire disturbance regimes on bacterial and arbuscular mycorrhizal fungal community structures in South African montane grasslands that have been subjected to an intermediate (up to five years) term experimental fire-return interval gradient. Bacterial communities in this study exhibited a shift in composition in soils subjected to annual and biennial fires compared to the controls, with carbon and nitrogen identified as significant potential chemical drivers of bacterial communities. Shifts in relative abundances of dominant fungal operational taxonomic units were noted, with Glomeromycota as the dominant arbuscular mycorrhiza observed across the fire-return gradient. A reduction in mycorrhizal root colonisation was also observed in frequently burnt autumnal grassland plots in this study. Furthermore, evidence of significant mutualistic interactions between bacteria and fungi that may act as drivers of the observed community structure were detected. Through this pilot study, we can show that fire regime strongly impacts bacterial and fungal communities in southern African montane grasslands, and that changes to their usually resilient structure are mediated by seasonal burn patterns, chemical drivers, and mutualistic interactions between these two groups.
- Full Text:
- Authors: Gokul, Jarishma K , Matcher, Gwynneth F , Dames, Joanna F , Nkangala, Kuhle , Gordijn, Paul J , Barker, Nigel P
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440366 , vital:73777 , https://doi.org/10.3390/d15070818
- Description: The influence of fire regimes on soil microbial diversity in montane grasslands is a relatively unexplored area of interest. Understanding the belowground diversity is a crucial stepping-stone toward unravelling community dynamics, nutrient sequestration, and overall ecosystem stability. In this study, metabarcoding was used to unravel the impact of fire disturbance regimes on bacterial and arbuscular mycorrhizal fungal community structures in South African montane grasslands that have been subjected to an intermediate (up to five years) term experimental fire-return interval gradient. Bacterial communities in this study exhibited a shift in composition in soils subjected to annual and biennial fires compared to the controls, with carbon and nitrogen identified as significant potential chemical drivers of bacterial communities. Shifts in relative abundances of dominant fungal operational taxonomic units were noted, with Glomeromycota as the dominant arbuscular mycorrhiza observed across the fire-return gradient. A reduction in mycorrhizal root colonisation was also observed in frequently burnt autumnal grassland plots in this study. Furthermore, evidence of significant mutualistic interactions between bacteria and fungi that may act as drivers of the observed community structure were detected. Through this pilot study, we can show that fire regime strongly impacts bacterial and fungal communities in southern African montane grasslands, and that changes to their usually resilient structure are mediated by seasonal burn patterns, chemical drivers, and mutualistic interactions between these two groups.
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Microplastics as vectors of chemical contaminants and biological agents in freshwater ecosystems: Current knowledge status and future perspectives
- Tumwesigye, Edgar, Nnadozie, Chika F, Akamagwuna, Frank C, Noundou, Xavier S, Nyakairu, George W A, Odume, Oghenekaro N
- Authors: Tumwesigye, Edgar , Nnadozie, Chika F , Akamagwuna, Frank C , Noundou, Xavier S , Nyakairu, George W A , Odume, Oghenekaro N
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/484484 , vital:78917 , https://doi.org/10.1016/j.envpol.2023.121829
- Description: Microplastics (MPs) are becoming ubiquitous, and their environmental fate is becoming an issue of concern. Our review aims to synthesize current knowledge status and provide future perspectives regarding the vector effect of MPs for chemical contaminants and biological agents. The evidence in the literature indicates that MPs are a vector for persistent organic pollutants (POPs), metals and pharmaceuticals. Concentrations of chemical contaminant in orders of six-fold higher on MPs surfaces than in the surrounding environmental waters have been reported. Chemical pollutants such as perfluoroalkyl substances (PAFSs), hexachlorocyclohexane (HCHs) and polycyclic aromatic hydrocarbons (PAHs), exhibiting polarities in the range of 3.3–9 are the commonest chemicals reported on MP surfaces. Regarding metals on MPs including chromium (Cr), lead (Pb), cobalt (Co), the presence of C–O and N–H in MPs promote a relatively high adsorption of these metals onto MP surfaces. Regarding pharmaceuticals, not much has been done, but a few studies indicate that commonly used drugs such as ibuprofen, ibuprofen, diclofenac, and naproxen have been associated with MPs. There is sufficient evidence supporting the claim that MPs can act as vectors for viruses, bacterial and antibiotic-resistant bacteria and genes, and MPs act to accelerate horizontal and vertical gene transfer. An area that deserves urgent attention is whether MPs can act as vectors for invertebrates and vertebrates, mainly non-native, invasive freshwater species. Despite the ecological significance of invasive biology, little research has been done in this regard. Overall, our review summarises the state of the current knowledge, identifies critical research gaps and provides perspectives for future research.
- Full Text:
- Authors: Tumwesigye, Edgar , Nnadozie, Chika F , Akamagwuna, Frank C , Noundou, Xavier S , Nyakairu, George W A , Odume, Oghenekaro N
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/484484 , vital:78917 , https://doi.org/10.1016/j.envpol.2023.121829
- Description: Microplastics (MPs) are becoming ubiquitous, and their environmental fate is becoming an issue of concern. Our review aims to synthesize current knowledge status and provide future perspectives regarding the vector effect of MPs for chemical contaminants and biological agents. The evidence in the literature indicates that MPs are a vector for persistent organic pollutants (POPs), metals and pharmaceuticals. Concentrations of chemical contaminant in orders of six-fold higher on MPs surfaces than in the surrounding environmental waters have been reported. Chemical pollutants such as perfluoroalkyl substances (PAFSs), hexachlorocyclohexane (HCHs) and polycyclic aromatic hydrocarbons (PAHs), exhibiting polarities in the range of 3.3–9 are the commonest chemicals reported on MP surfaces. Regarding metals on MPs including chromium (Cr), lead (Pb), cobalt (Co), the presence of C–O and N–H in MPs promote a relatively high adsorption of these metals onto MP surfaces. Regarding pharmaceuticals, not much has been done, but a few studies indicate that commonly used drugs such as ibuprofen, ibuprofen, diclofenac, and naproxen have been associated with MPs. There is sufficient evidence supporting the claim that MPs can act as vectors for viruses, bacterial and antibiotic-resistant bacteria and genes, and MPs act to accelerate horizontal and vertical gene transfer. An area that deserves urgent attention is whether MPs can act as vectors for invertebrates and vertebrates, mainly non-native, invasive freshwater species. Despite the ecological significance of invasive biology, little research has been done in this regard. Overall, our review summarises the state of the current knowledge, identifies critical research gaps and provides perspectives for future research.
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Mobile communication and urban/rural flows in a South African marginalised community
- Authors: Dalvit, Lorenzo
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/468162 , vital:77025 , https://doi.org/10.1177/000276422210928
- Description: This article draws on Castells’ concept of space of flows to explore the role of mobile communication in mediating the flows of ideas, people and resources concerning Dwesa, a rural community in South Africa. While it is the site of an ICT-for-development project fifteen years in the making, Dwesa is representative of many contemporary South African rural realities in terms of lack of infrastructure, endemic poverty and ur-ban migration. Mobile network coverage is almost universal, sustaining a bidirectional flow of people, resources and information between Dwe-sa and urban areas such as Cape Town. A critical review of the sub-stantial body of research conducted in the area, as well as thematic analysis of social media texts and semi-structured interviews with community members, reveal that mobile phones play an important and nuanced role in arranging physical or virtual rendezvous, facilitating transfers of monetary and other resources, and enabling timeless communication and exchange of information across distance.
- Full Text:
- Authors: Dalvit, Lorenzo
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/468162 , vital:77025 , https://doi.org/10.1177/000276422210928
- Description: This article draws on Castells’ concept of space of flows to explore the role of mobile communication in mediating the flows of ideas, people and resources concerning Dwesa, a rural community in South Africa. While it is the site of an ICT-for-development project fifteen years in the making, Dwesa is representative of many contemporary South African rural realities in terms of lack of infrastructure, endemic poverty and ur-ban migration. Mobile network coverage is almost universal, sustaining a bidirectional flow of people, resources and information between Dwe-sa and urban areas such as Cape Town. A critical review of the sub-stantial body of research conducted in the area, as well as thematic analysis of social media texts and semi-structured interviews with community members, reveal that mobile phones play an important and nuanced role in arranging physical or virtual rendezvous, facilitating transfers of monetary and other resources, and enabling timeless communication and exchange of information across distance.
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Mobile money taxation and informal workers: Evidence from Ghana's E‐levy
- Anyidoho, Nana A, Gallien, Max, Rogan, Michael, Van den Boogaard, Vanessa
- Authors: Anyidoho, Nana A , Gallien, Max , Rogan, Michael , Van den Boogaard, Vanessa
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/477985 , vital:78144 , https://doi.org/10.1111/dpr.12704
- Description: In recent years, governments in low-income countries have increasingly introduced taxes on mobile money transfers. These are often explicitly promoted as a way of taxing informal economic activity, but critics have noted their potential negative impact on lower-income groups and specifically those in the informal sector. Yet there is virtually no evidence base on the effects of mobile money taxes on informal workers. This article assesses how informal workers in Accra, Ghana, use mobile money and how they perceive Ghana's Electronic Transfer Levy (E-levy), introduced in May 2022. This provides a particularly interesting case study to explore the equity implications of the tax, as the policy was explicitly justified as a way of taxing the informal economy but also includes measures to limit the tax burden on lower-income groups.
- Full Text:
- Authors: Anyidoho, Nana A , Gallien, Max , Rogan, Michael , Van den Boogaard, Vanessa
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/477985 , vital:78144 , https://doi.org/10.1111/dpr.12704
- Description: In recent years, governments in low-income countries have increasingly introduced taxes on mobile money transfers. These are often explicitly promoted as a way of taxing informal economic activity, but critics have noted their potential negative impact on lower-income groups and specifically those in the informal sector. Yet there is virtually no evidence base on the effects of mobile money taxes on informal workers. This article assesses how informal workers in Accra, Ghana, use mobile money and how they perceive Ghana's Electronic Transfer Levy (E-levy), introduced in May 2022. This provides a particularly interesting case study to explore the equity implications of the tax, as the policy was explicitly justified as a way of taxing the informal economy but also includes measures to limit the tax burden on lower-income groups.
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Mosquito community composition in Central District, Botswana: insights from a malaria endemic to non-endemic gradient
- Buxton, M, Nyamukondiwa, C, Kesamang, M, Wasserman, Ryan J
- Authors: Buxton, M , Nyamukondiwa, C , Kesamang, M , Wasserman, Ryan J
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/452402 , vital:75126 , http://dx.doi.org/10.17159/2254-8854/2022/a13584
- Description: Spatial distribution of vector mosquitoes plays a critical role in the dynamics of associated diseases' spread across diverse landscapes. In Botswana, six Districts are implicated as malaria endemic zones, one of which is the Central District comprising both malaria endemic and non-endemic sub-districts. Despite being the biggest in the country, mosquito diversity in this District is under-explored, more so in the malaria non-endemic sub-districts. Here, we thus sampled mosquito adults and larvae from the malaria endemic sub-district of Bobirwa and non-endemic sub-districts of Palapye and Serowe, to determine spatial mosquito abundance and diversity in the District.
- Full Text:
- Authors: Buxton, M , Nyamukondiwa, C , Kesamang, M , Wasserman, Ryan J
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/452402 , vital:75126 , http://dx.doi.org/10.17159/2254-8854/2022/a13584
- Description: Spatial distribution of vector mosquitoes plays a critical role in the dynamics of associated diseases' spread across diverse landscapes. In Botswana, six Districts are implicated as malaria endemic zones, one of which is the Central District comprising both malaria endemic and non-endemic sub-districts. Despite being the biggest in the country, mosquito diversity in this District is under-explored, more so in the malaria non-endemic sub-districts. Here, we thus sampled mosquito adults and larvae from the malaria endemic sub-district of Bobirwa and non-endemic sub-districts of Palapye and Serowe, to determine spatial mosquito abundance and diversity in the District.
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Multispectral Plant Disease Detection with Vision Transformer–Convolutional Neural Network Hybrid Approaches
- De Silva, Malitha, Brown, Dane L
- Authors: De Silva, Malitha , Brown, Dane L
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/463428 , vital:76408 , xlink:href="https://doi.org/10.3390/s23208531"
- Description: Plant diseases pose a critical threat to global agricultural productivity, demanding timely detection for effective crop yield management. Traditional methods for disease identification are laborious and require specialised expertise. Leveraging cutting-edge deep learning algorithms, this study explores innovative approaches to plant disease identification, combining Convolutional Neural Networks (CNNs) and Vision Transformers (ViTs) to enhance accuracy. A multispectral dataset was meticulously collected to facilitate this research using six 50 mm filter filters, covering both the visible and several near-infrared (NIR) wavelengths. Among the models employed, ViT-B16 notably achieved the highest test accuracy, precision, recall, and F1 score across all filters, with averages of 83.3%, 90.1%, 90.75%, and 89.5%, respectively. Furthermore, a comparative analysis highlights the pivotal role of balanced datasets in selecting the appropriate wavelength and deep learning model for robust disease identification. These findings promise to advance crop disease management in real-world agricultural applications and contribute to global food security. The study underscores the significance of machine learning in transforming plant disease diagnostics and encourages further research in this field.
- Full Text:
- Authors: De Silva, Malitha , Brown, Dane L
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/463428 , vital:76408 , xlink:href="https://doi.org/10.3390/s23208531"
- Description: Plant diseases pose a critical threat to global agricultural productivity, demanding timely detection for effective crop yield management. Traditional methods for disease identification are laborious and require specialised expertise. Leveraging cutting-edge deep learning algorithms, this study explores innovative approaches to plant disease identification, combining Convolutional Neural Networks (CNNs) and Vision Transformers (ViTs) to enhance accuracy. A multispectral dataset was meticulously collected to facilitate this research using six 50 mm filter filters, covering both the visible and several near-infrared (NIR) wavelengths. Among the models employed, ViT-B16 notably achieved the highest test accuracy, precision, recall, and F1 score across all filters, with averages of 83.3%, 90.1%, 90.75%, and 89.5%, respectively. Furthermore, a comparative analysis highlights the pivotal role of balanced datasets in selecting the appropriate wavelength and deep learning model for robust disease identification. These findings promise to advance crop disease management in real-world agricultural applications and contribute to global food security. The study underscores the significance of machine learning in transforming plant disease diagnostics and encourages further research in this field.
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Nagoya Protocol and Africa’s willingness to share biological control agents, are we deterred by barriers instead of using opportunities to work together?
- Ivey, Philip J, Hill, Martin P, Voukeng, Sonia Nadege Kenfack, Weaver, Kim N
- Authors: Ivey, Philip J , Hill, Martin P , Voukeng, Sonia Nadege Kenfack , Weaver, Kim N
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/418040 , vital:71503 , xlink:href="https://doi.org/10.1007/s10526-023-10184-8"
- Description: Amongst members of the biological control community there is a range of perceptions regarding the Nagoya Protocol, at best it will hinder access to natural enemies of pests and invasive plants and at worst implementation of the Protocol will prevent access to these resources. In this preliminary study of Africa’s preparedness to implement the Nagoya Protocol and control access to potential biological control agents, we found that several countries have not yet established procedures and policies in this regard. Several factors including lack of awareness, insufficient relevant information and lack of capacity may cause delay in countries implementing access and benefit sharing legislation and processes. The lack of preparedness provides an opportunity for the research community to work with government officials to facilitate future access to natural enemies to act as biological control agents on invasive plants and agricultural pests. Collaboration between researchers, managers and bureaucrats in support of African countries could lead to collective action that develops policies and implements processes to foster exploration of African biodiversity. This collaboration could also foster the sharing of biological control agents that will benefit Africa through integrated pest management in agriculture, protection of human lives and livelihoods, and reduction of the impact of invasive alien species on biodiversity and environmental infrastructure.
- Full Text:
- Authors: Ivey, Philip J , Hill, Martin P , Voukeng, Sonia Nadege Kenfack , Weaver, Kim N
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/418040 , vital:71503 , xlink:href="https://doi.org/10.1007/s10526-023-10184-8"
- Description: Amongst members of the biological control community there is a range of perceptions regarding the Nagoya Protocol, at best it will hinder access to natural enemies of pests and invasive plants and at worst implementation of the Protocol will prevent access to these resources. In this preliminary study of Africa’s preparedness to implement the Nagoya Protocol and control access to potential biological control agents, we found that several countries have not yet established procedures and policies in this regard. Several factors including lack of awareness, insufficient relevant information and lack of capacity may cause delay in countries implementing access and benefit sharing legislation and processes. The lack of preparedness provides an opportunity for the research community to work with government officials to facilitate future access to natural enemies to act as biological control agents on invasive plants and agricultural pests. Collaboration between researchers, managers and bureaucrats in support of African countries could lead to collective action that develops policies and implements processes to foster exploration of African biodiversity. This collaboration could also foster the sharing of biological control agents that will benefit Africa through integrated pest management in agriculture, protection of human lives and livelihoods, and reduction of the impact of invasive alien species on biodiversity and environmental infrastructure.
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Nature-Connectedness and Well-Being Experienced During Best and Worst Times of Life: A Case for Safeguarding Biocultural Diversity
- Møller, Valerie, Cocks, Michelle L, Vetter, Susanne M
- Authors: Møller, Valerie , Cocks, Michelle L , Vetter, Susanne M
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426516 , vital:72359 , xlink:href="https://doi.org/10.1007/s11205-023-03063-3"
- Description: South Africa boasts some of the richest diversity of fauna and flora in the world; it also claims to be a world in one country given its cultural diversity. In a time of climate change, rapid population growth and urbanisation, the country’s natural resources as well as its cultural diversity are under threat. We report a multi-dimensional survey conducted among Xhosa-speaking people in the Eastern Cape Province of South Africa, that collected detailed information on indigenous knowledge of nature and its impact on cultural practices and well-being. Survey respondents included both rural and urban dwellers, a majority of whom professed to be Christians who also held traditional religious beliefs and acknowledged the ancestors. Survey respondents described their Best and Worst periods of life in line with Bernheim’s Anamnestic Comparative Self-Assessment, and indicated whether going into nature had contributed to their Best life experience and helped them to cope during their Worst one. Being in nature typically contributed to well-being across many of the Best social domains of life, such as celebrations with family, personal achievements and milestones in life, including traditional rites of passage to adulthood. Deaths in the family represented by far the most common Worst experience in life when going into nature often provided comfort and solace. Findings suggest that experience of the multiple benefits of being in nature may be universal across cultures and that many traditional Xhosa religious beliefs and cultural practices go hand in hand with access and exposure to nature that enhances well-being.
- Full Text:
- Authors: Møller, Valerie , Cocks, Michelle L , Vetter, Susanne M
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426516 , vital:72359 , xlink:href="https://doi.org/10.1007/s11205-023-03063-3"
- Description: South Africa boasts some of the richest diversity of fauna and flora in the world; it also claims to be a world in one country given its cultural diversity. In a time of climate change, rapid population growth and urbanisation, the country’s natural resources as well as its cultural diversity are under threat. We report a multi-dimensional survey conducted among Xhosa-speaking people in the Eastern Cape Province of South Africa, that collected detailed information on indigenous knowledge of nature and its impact on cultural practices and well-being. Survey respondents included both rural and urban dwellers, a majority of whom professed to be Christians who also held traditional religious beliefs and acknowledged the ancestors. Survey respondents described their Best and Worst periods of life in line with Bernheim’s Anamnestic Comparative Self-Assessment, and indicated whether going into nature had contributed to their Best life experience and helped them to cope during their Worst one. Being in nature typically contributed to well-being across many of the Best social domains of life, such as celebrations with family, personal achievements and milestones in life, including traditional rites of passage to adulthood. Deaths in the family represented by far the most common Worst experience in life when going into nature often provided comfort and solace. Findings suggest that experience of the multiple benefits of being in nature may be universal across cultures and that many traditional Xhosa religious beliefs and cultural practices go hand in hand with access and exposure to nature that enhances well-being.
- Full Text:
New mythologies: violence and colonialism in Hollywood blockbusters
- Authors: Boshoff, Priscilla A
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/455521 , vital:75436 , https://doi.org/10.1080/17533171.2023.2272500
- Description: Countries create mythologies about themselves in their self-representations in film. This is nothing new. The United States of Amer-ica has done so with great success for over a hundred years through the Hollywood “machine.” 1 On the one hand, this mythology can serve as a form of propaganda that is accepted uncritically by many as “reali-ty.” On the other, it takes the form of wishful thinking which may in cer-tain ways be even more revealing than realism of the motivations be-hind a nation’s mythologizing. Here, Marvel comics present an apt ex-ample of how the United States’ selfimage takes shape in the public imagination: exceptional powers, huge muscles, dominion over man and nature through science. One of these heroes is even called Cap-tain America. In short, a fantasy of potential total control. We take for granted that this mythologizing concerns the country’s own powers, a form of public self-regard. This much is to be expected.
- Full Text:
- Authors: Boshoff, Priscilla A
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/455521 , vital:75436 , https://doi.org/10.1080/17533171.2023.2272500
- Description: Countries create mythologies about themselves in their self-representations in film. This is nothing new. The United States of Amer-ica has done so with great success for over a hundred years through the Hollywood “machine.” 1 On the one hand, this mythology can serve as a form of propaganda that is accepted uncritically by many as “reali-ty.” On the other, it takes the form of wishful thinking which may in cer-tain ways be even more revealing than realism of the motivations be-hind a nation’s mythologizing. Here, Marvel comics present an apt ex-ample of how the United States’ selfimage takes shape in the public imagination: exceptional powers, huge muscles, dominion over man and nature through science. One of these heroes is even called Cap-tain America. In short, a fantasy of potential total control. We take for granted that this mythologizing concerns the country’s own powers, a form of public self-regard. This much is to be expected.
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Oxpecker host-selection in the Salambala conservancy, northeastern Namibia
- Lukubwe, Michael S, Craig, Adrian J F K, Manyangadze, Tawanda
- Authors: Lukubwe, Michael S , Craig, Adrian J F K , Manyangadze, Tawanda
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/449934 , vital:74866 , https://doi.org/10.3957/056.053.0166
- Description: By studying the host-selection patterns of oxpecker species, researchers can gain valuable insights into their ecological roles and interactions with different host species. This information is crucial for developing effective conservation strategies that prioritise the protection of oxpeckers and their host populations. The study conducted field observations and recorded data on the number of oxpeckers and their respective host species. Additionally, this study investigated the relationship between host species and host parameters (body mass and hair length) in the Salambala conservancy in northeastern Namibia. Selection and density indices were used to calculate the number of host animals supporting one oxpecker as well as the oxpecker density on a host's body surface. Pentad-based counts of oxpeckers and ungulates were conducted.
- Full Text:
- Authors: Lukubwe, Michael S , Craig, Adrian J F K , Manyangadze, Tawanda
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/449934 , vital:74866 , https://doi.org/10.3957/056.053.0166
- Description: By studying the host-selection patterns of oxpecker species, researchers can gain valuable insights into their ecological roles and interactions with different host species. This information is crucial for developing effective conservation strategies that prioritise the protection of oxpeckers and their host populations. The study conducted field observations and recorded data on the number of oxpeckers and their respective host species. Additionally, this study investigated the relationship between host species and host parameters (body mass and hair length) in the Salambala conservancy in northeastern Namibia. Selection and density indices were used to calculate the number of host animals supporting one oxpecker as well as the oxpecker density on a host's body surface. Pentad-based counts of oxpeckers and ungulates were conducted.
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Performance and field host range of the life stages of Cornops aquaticum, a biological control agent of water hyacinth
- Franceschini, M Celeste, Hill, Martin P, Fuentes-Rodríguez, Daniela, Gervazoni, Paula B, Sabater, Lara M, Coetzee, Julie A
- Authors: Franceschini, M Celeste , Hill, Martin P , Fuentes-Rodríguez, Daniela , Gervazoni, Paula B , Sabater, Lara M , Coetzee, Julie A
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/424814 , vital:72186 , xlink:href="https://doi.org/10.1111/eea.13354"
- Description: Host specificity determination of weed biocontrol agents has historically relied on evidence generated through quarantine trials in the region of introduction. These trials could give ‘false positive’ results due to a maximum type I error probability, and where possible, more research under field conditions should be conducted in the region of origin. The oligophagous, semiaquatic grasshopper, Cornops aquaticum Bruner (Orthoptera: Acrididae, Tetrataeniini), was released in South Africa for the biological control of Pontederia crassipes Pellegrini and Horn (Pontederiaceae). The aim of this study was to assess how the performance and field host range of C. aquaticum varies according to its stages of development, and how this contributes to the understanding of the relationship between the fundamental (laboratory-based) and the ecological (field-based) host range of this grasshopper, and its implications for water hyacinth biocontrol. We conducted post-release laboratory no-choice trials, confining early instars (instars 1 and 2), later instars (instars 3–6), and adult females and males in mesh cages, to determine insect performance on wetland plants growing in sympatry with P. crassipes. Also, gut analysis from field-collected C. aquaticum was done to determine the ecological host range of this insect, identifying epidermal tissue of consumed plants. In no-choice trials, survival rates of the later instars and adult C. aquaticum were similar on Pistia stratiotes L. (Araceae), Oxycaryum cubense (Poepp. and Kunth) Lye (Cyperaceae), and P. crassipes. However, under field conditions, P. crassipes and the congeneric Pontederia azurea Sw. were the only plant contents in the guts of early instars and the most abundant species in later instars and adults. The results support the hypothesis that C. aquaticum is an oligophagous insect on the genus Pontederia, and that different life stages should be considered when conducting host-specificity trials in externally feeding mobile herbivore species. Diet composition of field-collected insects thus could help detect false positives in laboratory trials, being an additional and realistic approach in understanding and predicting the selection processes of the insect in the new environment. Retrospective analysis of potential agents that were rejected due to lack of host-specificity, using the methods from this study, could add a suite of additional agents to programs where invasive weeds remain unmanaged.
- Full Text:
- Authors: Franceschini, M Celeste , Hill, Martin P , Fuentes-Rodríguez, Daniela , Gervazoni, Paula B , Sabater, Lara M , Coetzee, Julie A
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/424814 , vital:72186 , xlink:href="https://doi.org/10.1111/eea.13354"
- Description: Host specificity determination of weed biocontrol agents has historically relied on evidence generated through quarantine trials in the region of introduction. These trials could give ‘false positive’ results due to a maximum type I error probability, and where possible, more research under field conditions should be conducted in the region of origin. The oligophagous, semiaquatic grasshopper, Cornops aquaticum Bruner (Orthoptera: Acrididae, Tetrataeniini), was released in South Africa for the biological control of Pontederia crassipes Pellegrini and Horn (Pontederiaceae). The aim of this study was to assess how the performance and field host range of C. aquaticum varies according to its stages of development, and how this contributes to the understanding of the relationship between the fundamental (laboratory-based) and the ecological (field-based) host range of this grasshopper, and its implications for water hyacinth biocontrol. We conducted post-release laboratory no-choice trials, confining early instars (instars 1 and 2), later instars (instars 3–6), and adult females and males in mesh cages, to determine insect performance on wetland plants growing in sympatry with P. crassipes. Also, gut analysis from field-collected C. aquaticum was done to determine the ecological host range of this insect, identifying epidermal tissue of consumed plants. In no-choice trials, survival rates of the later instars and adult C. aquaticum were similar on Pistia stratiotes L. (Araceae), Oxycaryum cubense (Poepp. and Kunth) Lye (Cyperaceae), and P. crassipes. However, under field conditions, P. crassipes and the congeneric Pontederia azurea Sw. were the only plant contents in the guts of early instars and the most abundant species in later instars and adults. The results support the hypothesis that C. aquaticum is an oligophagous insect on the genus Pontederia, and that different life stages should be considered when conducting host-specificity trials in externally feeding mobile herbivore species. Diet composition of field-collected insects thus could help detect false positives in laboratory trials, being an additional and realistic approach in understanding and predicting the selection processes of the insect in the new environment. Retrospective analysis of potential agents that were rejected due to lack of host-specificity, using the methods from this study, could add a suite of additional agents to programs where invasive weeds remain unmanaged.
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Performance determinants of life insurers: A systematic review of the literature
- Zinyoro, Tafadzwanash, Aziakpono, Meshach J
- Authors: Zinyoro, Tafadzwanash , Aziakpono, Meshach J
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/469908 , vital:77306 , https://doi.org/10.1080/23322039.2023.2266915
- Description: The life insurance industry plays a crucial role in the economy as it serves as one of the channels through which countries mobilize long-term savings, promote the development of capital markets, foster efficient capital allocation, and substitute and complement government security programs. Therefore, the performance of this sector is imperative. Since the early 1990s, researchers have been paying particular attention to the performance of life insurance firms, with a specific emphasis on identifying the key determinants of their performance. The objective of this study is to synthesize the studies that have explored this topic. Using a systematic literature review approach, the study reviews 129 studies published between 1990 and 2021. The analysis reveals that the literature primarily examines factors such as size, organizational structure, capital composition, diversification, distribution systems, risk management practices, and reinsurance strategies as key firm-specific drivers of life insurer performance. Additionally, the study underscores the importance of competition and macroeconomic conditions as commonly discussed external determinants. While a clear relationship between performance and factors like firm size, organizational structure, and risk management practices is evident, the impact of other factors remains inconclusive. One of the implications of this study is that policymakers should enact laws that promote competition in the insurance industry. The study also reveals several research gaps, including methodological gaps.
- Full Text:
- Authors: Zinyoro, Tafadzwanash , Aziakpono, Meshach J
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/469908 , vital:77306 , https://doi.org/10.1080/23322039.2023.2266915
- Description: The life insurance industry plays a crucial role in the economy as it serves as one of the channels through which countries mobilize long-term savings, promote the development of capital markets, foster efficient capital allocation, and substitute and complement government security programs. Therefore, the performance of this sector is imperative. Since the early 1990s, researchers have been paying particular attention to the performance of life insurance firms, with a specific emphasis on identifying the key determinants of their performance. The objective of this study is to synthesize the studies that have explored this topic. Using a systematic literature review approach, the study reviews 129 studies published between 1990 and 2021. The analysis reveals that the literature primarily examines factors such as size, organizational structure, capital composition, diversification, distribution systems, risk management practices, and reinsurance strategies as key firm-specific drivers of life insurer performance. Additionally, the study underscores the importance of competition and macroeconomic conditions as commonly discussed external determinants. While a clear relationship between performance and factors like firm size, organizational structure, and risk management practices is evident, the impact of other factors remains inconclusive. One of the implications of this study is that policymakers should enact laws that promote competition in the insurance industry. The study also reveals several research gaps, including methodological gaps.
- Full Text:
Performing the archive as interdisciplinary artistic-educational process
- Authors: Parker, Alan , Samuel, G M
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/469151 , vital:77214 , ISBN 9781000768770
- Description: Since 2015, South African tertiary education institutions have been deeply embroiled in processes of re-thinking pedagogies and curricula, spurred by calls for decolonial change by young student-led, national movements such as# Rhodesmustfall and# Feesmustfall. In the field of performance studies and practice, this has initiated a welcomed re-imagining of how teaching and learning occur within the performing arts in South Africa where diverse disciplines, forms, histories and discourses, connecting to a wide range of both indigenous and global contexts, combine in the training of multi-skilled, critically aware performers, theatre-makers, educators and researchers. At the University of Cape Town, in particular, this process has been complemented by the recent merger between the School of Dance and the Department of Drama into the newly formed Centre for Theatre, Dance and Performance Studies. Through this merging of artistic disciplines, the decolonial re-thinking of teaching and learning has been augmented by a significant move towards artistic interdisciplinarity and a strong focus on experimentation and research within performancemaking practices. As educators and choreographers working within this particular context, we have found the intersection between “choreographic performance”(Cvejić, 2015, p. 14) 1 and the archive to be a particularly rich and open field of possibility where critical questions can be asked, through the body, about the relationality between the past and the present and where tacit ideologies, socio-cultural belief systems and geopolitical perspectives, often implicit in bodies and their behaviours, can be surfaced and openly critiqued.
- Full Text:
- Authors: Parker, Alan , Samuel, G M
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/469151 , vital:77214 , ISBN 9781000768770
- Description: Since 2015, South African tertiary education institutions have been deeply embroiled in processes of re-thinking pedagogies and curricula, spurred by calls for decolonial change by young student-led, national movements such as# Rhodesmustfall and# Feesmustfall. In the field of performance studies and practice, this has initiated a welcomed re-imagining of how teaching and learning occur within the performing arts in South Africa where diverse disciplines, forms, histories and discourses, connecting to a wide range of both indigenous and global contexts, combine in the training of multi-skilled, critically aware performers, theatre-makers, educators and researchers. At the University of Cape Town, in particular, this process has been complemented by the recent merger between the School of Dance and the Department of Drama into the newly formed Centre for Theatre, Dance and Performance Studies. Through this merging of artistic disciplines, the decolonial re-thinking of teaching and learning has been augmented by a significant move towards artistic interdisciplinarity and a strong focus on experimentation and research within performancemaking practices. As educators and choreographers working within this particular context, we have found the intersection between “choreographic performance”(Cvejić, 2015, p. 14) 1 and the archive to be a particularly rich and open field of possibility where critical questions can be asked, through the body, about the relationality between the past and the present and where tacit ideologies, socio-cultural belief systems and geopolitical perspectives, often implicit in bodies and their behaviours, can be surfaced and openly critiqued.
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Persistent effects of historical sea levels on the population structure of a temporary wetland copepod
- Emami-Khoyi, Arsalan, Jooste, Candice M, Wasserman, Ryan J, Dalu, Tatenda, Raath-Krüger, Morgan J, Jansen van Vuuren, Bettine, Teske, Peter R
- Authors: Emami-Khoyi, Arsalan , Jooste, Candice M , Wasserman, Ryan J , Dalu, Tatenda , Raath-Krüger, Morgan J , Jansen van Vuuren, Bettine , Teske, Peter R
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445115 , vital:74348 , https://doi.org/10.1111/fwb.14139
- Description: Temporary wetland ecosystems are common in arid and semi‐arid envi-ronments, and are inhabited by diverse invertebrate communities. Little is known about the dynamics of genetic connectivity in the geograph-ically scattered populations of these wetland specialists. The current study investigated the spatial genetic structure and dispersal history of a recently described calanoid copepod, Lovenula raynerae, reported from temporary wetlands in the Eastern Cape province of South Africa. We tested whether the species represents a single, well‐connected population or comprises different regional genetic groups, some of which may be rare or endangered.
- Full Text:
- Authors: Emami-Khoyi, Arsalan , Jooste, Candice M , Wasserman, Ryan J , Dalu, Tatenda , Raath-Krüger, Morgan J , Jansen van Vuuren, Bettine , Teske, Peter R
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445115 , vital:74348 , https://doi.org/10.1111/fwb.14139
- Description: Temporary wetland ecosystems are common in arid and semi‐arid envi-ronments, and are inhabited by diverse invertebrate communities. Little is known about the dynamics of genetic connectivity in the geograph-ically scattered populations of these wetland specialists. The current study investigated the spatial genetic structure and dispersal history of a recently described calanoid copepod, Lovenula raynerae, reported from temporary wetlands in the Eastern Cape province of South Africa. We tested whether the species represents a single, well‐connected population or comprises different regional genetic groups, some of which may be rare or endangered.
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Photoantimicrobial activity of Schiff-base morpholino phthalocyanines against drug resistant micro-organisms in their planktonic and biofilm forms
- Sindelo, Azole, Sen, Pinar, Nyokong, Tebello
- Authors: Sindelo, Azole , Sen, Pinar , Nyokong, Tebello
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/360437 , vital:65088 , xlink:href="https://doi.org/10.1016/j.pdpdt.2023.103519"
- Description: Antimicrobial photodynamic inactivation (aPDI) is a treatment for the eradication of drug-resistant micro-organisms. One of the advantages of this technique, is that there is minimal possibility of microbial resistance. Hence, herein, the preparation and characterization of novel neutral and cationic morpholine containing Schiff base phthalocyanines are reported. The cationic complexes gave moderate singlet oxygen quantum yields (ΦΔ) of ∼0.2 in aqueous media. Conversely, the neutral complexes generated very low ΦΔ values making them very poor candidates for antimicrobial studies. The cationic phthalocyanines showed excellent photodynamic activity against planktonic cells of all micro-organisms (Candida albicans, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Salmonella enterica subspecies enterica serovar Choleraesuis, vancomycin-resistant Enterococcus faecium, and methicillin-resistant Staphylococcus aureus). The efficiency of aPDI was shown to be both concentration and light-dose-dependent. Mono biofilms were susceptible when treated with 200 µM of cationic Pcs at 108 J/cm2. However, ∼10% of the mixed biofilm survived after treatment.
- Full Text:
- Authors: Sindelo, Azole , Sen, Pinar , Nyokong, Tebello
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/360437 , vital:65088 , xlink:href="https://doi.org/10.1016/j.pdpdt.2023.103519"
- Description: Antimicrobial photodynamic inactivation (aPDI) is a treatment for the eradication of drug-resistant micro-organisms. One of the advantages of this technique, is that there is minimal possibility of microbial resistance. Hence, herein, the preparation and characterization of novel neutral and cationic morpholine containing Schiff base phthalocyanines are reported. The cationic complexes gave moderate singlet oxygen quantum yields (ΦΔ) of ∼0.2 in aqueous media. Conversely, the neutral complexes generated very low ΦΔ values making them very poor candidates for antimicrobial studies. The cationic phthalocyanines showed excellent photodynamic activity against planktonic cells of all micro-organisms (Candida albicans, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Salmonella enterica subspecies enterica serovar Choleraesuis, vancomycin-resistant Enterococcus faecium, and methicillin-resistant Staphylococcus aureus). The efficiency of aPDI was shown to be both concentration and light-dose-dependent. Mono biofilms were susceptible when treated with 200 µM of cationic Pcs at 108 J/cm2. However, ∼10% of the mixed biofilm survived after treatment.
- Full Text:
Photodynamic inactivation of methicillin-resistant Staphylococcus aureus using pyrrolidinium containing Schiff base phthalocyanines
- Sindelo, Azole, Sen, Pinar, Nyokong, Tebello
- Authors: Sindelo, Azole , Sen, Pinar , Nyokong, Tebello
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/360449 , vital:65089 , xlink:href="https://doi.org/10.1016/j.jphotochem.2022.114535"
- Description: New tetra-substituted zinc and indium Schiff base phthalocyanines (ZnPc and InPc, respectively) are synthesized and characterized herein. The ethyl pyrrolidine (ZnPc-2, InPc-2) and propyl pyrrolidine (ZnPc-3, InPc-3) substituted Schiff base Pcs were reacted with methyl iodide to form their cationic derivatives (ZnPc-2Q, InPc-2Q, ZnPc-3Q, and InPc-3Q, respectively). The photophysical and photochemical properties of the Pcs were studied. The cationic Pcs generated higher singlet oxygen quantum yield in aqueous media than the neutral Pcs. The photoinactivation of Methicillin-resistant Staphylococcus aureus (MRSA) and Methicillin-sensitive Staphylococcus aureus (MSSA) strains was evaluated. 5 µM ZnPc-3Q and InPc-3Q inactivated 100 % of the MSSA and MRSA while 5 µM ZnPc-2Q and InPc-2Q eradicated 100 % for MSSA and 97.2 % and 98.7 % (respectively) of the MRSA. The photodynamic antimicrobial chemotherapy studies depended on singlet oxygen ability, the charges, and the extension of the alkyl groups.
- Full Text:
- Authors: Sindelo, Azole , Sen, Pinar , Nyokong, Tebello
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/360449 , vital:65089 , xlink:href="https://doi.org/10.1016/j.jphotochem.2022.114535"
- Description: New tetra-substituted zinc and indium Schiff base phthalocyanines (ZnPc and InPc, respectively) are synthesized and characterized herein. The ethyl pyrrolidine (ZnPc-2, InPc-2) and propyl pyrrolidine (ZnPc-3, InPc-3) substituted Schiff base Pcs were reacted with methyl iodide to form their cationic derivatives (ZnPc-2Q, InPc-2Q, ZnPc-3Q, and InPc-3Q, respectively). The photophysical and photochemical properties of the Pcs were studied. The cationic Pcs generated higher singlet oxygen quantum yield in aqueous media than the neutral Pcs. The photoinactivation of Methicillin-resistant Staphylococcus aureus (MRSA) and Methicillin-sensitive Staphylococcus aureus (MSSA) strains was evaluated. 5 µM ZnPc-3Q and InPc-3Q inactivated 100 % of the MSSA and MRSA while 5 µM ZnPc-2Q and InPc-2Q eradicated 100 % for MSSA and 97.2 % and 98.7 % (respectively) of the MRSA. The photodynamic antimicrobial chemotherapy studies depended on singlet oxygen ability, the charges, and the extension of the alkyl groups.
- Full Text:
Plant Disease Detection using Vision Transformers on Multispectral Natural Environment Images
- De Silva, Malitha, Brown, Dane L
- Authors: De Silva, Malitha , Brown, Dane L
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/463456 , vital:76410 , xlink:href="https://ieeexplore.ieee.org/abstract/document/10220517"
- Description: Enhancing agricultural practices has become essential in mitigating global hunger. Over the years, significant technological advancements have been introduced to improve the quality and quantity of harvests by effectively managing weeds, pests, and diseases. Many studies have focused on identifying plant diseases, as this information aids in making informed decisions about applying fungicides and fertilizers. Advanced systems often employ a combination of image processing and deep learning techniques to identify diseases based on visible symptoms. However, these systems typically rely on pre-existing datasets or images captured in controlled environments. This study showcases the efficacy of utilizing multispectral images captured in visible and Near Infrared (NIR) ranges for identifying plant diseases in real-world environmental conditions. The collected datasets were classified using popular Vision Transformer (ViT) models, including ViT- S16, ViT-BI6, ViT-LI6 and ViT-B32. The results showed impressive training and test accuracies for all the data collected using diverse Kolari vision lenses with 93.71 % and 90.02 %, respectively. This work highlights the potential of utilizing advanced imaging techniques for accurate and reliable plant disease identification in practical field conditions.
- Full Text:
- Authors: De Silva, Malitha , Brown, Dane L
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/463456 , vital:76410 , xlink:href="https://ieeexplore.ieee.org/abstract/document/10220517"
- Description: Enhancing agricultural practices has become essential in mitigating global hunger. Over the years, significant technological advancements have been introduced to improve the quality and quantity of harvests by effectively managing weeds, pests, and diseases. Many studies have focused on identifying plant diseases, as this information aids in making informed decisions about applying fungicides and fertilizers. Advanced systems often employ a combination of image processing and deep learning techniques to identify diseases based on visible symptoms. However, these systems typically rely on pre-existing datasets or images captured in controlled environments. This study showcases the efficacy of utilizing multispectral images captured in visible and Near Infrared (NIR) ranges for identifying plant diseases in real-world environmental conditions. The collected datasets were classified using popular Vision Transformer (ViT) models, including ViT- S16, ViT-BI6, ViT-LI6 and ViT-B32. The results showed impressive training and test accuracies for all the data collected using diverse Kolari vision lenses with 93.71 % and 90.02 %, respectively. This work highlights the potential of utilizing advanced imaging techniques for accurate and reliable plant disease identification in practical field conditions.
- Full Text: