It's a numbers game: inundative biological control of water hyacinth (Pontederia crassipes), using Megamelus scutellaris (Hemiptera: Delphacidae) yields success at a high elevation, hypertrophic reservoir in South Africa
- Coetzee, Julie A, Miller, Benjamin E, Kinsler, David, Sebola, Keneilwe, Hill, Martin P
- Authors: Coetzee, Julie A , Miller, Benjamin E , Kinsler, David , Sebola, Keneilwe , Hill, Martin P
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417749 , vital:71483 , xlink:href="https://doi.org/10.1080/09583157.2022.2109594"
- Description: Classical biological control of water hyacinth in South Africa has been constrained by cool winter temperatures that limit population growth of the biological control agents, and highly eutrophic waters which enhance plant growth. However, inundative releases of the control agent, Megamelus scutellaris (Hemiptera: Delphacidae), at the Hartbeespoort Dam, South Africa, suggest that water hyacinth can be managed successfully using biological control as a standalone intervention for the first time in the absence of herbicide operations, despite eutrophication and a temperate climate. Sentinel-2 satellite images were used to measure the reduction in water hyacinth cover from over 37% to less than 6% over two consecutive years since M. scutellaris was first released on the dam in 2018, while site surveys confirmed a corresponding increase in M. scutellaris population density from fewer than 500 insects/m2 in October 2019, to more than 6000 insects/m2 by March 2020. Inundative release strategies are recommended for the control of water hyacinth in South Africa at key stages of its invasion, particularly after winter, and flooding events.
- Full Text:
- Date Issued: 2022
- Authors: Coetzee, Julie A , Miller, Benjamin E , Kinsler, David , Sebola, Keneilwe , Hill, Martin P
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417749 , vital:71483 , xlink:href="https://doi.org/10.1080/09583157.2022.2109594"
- Description: Classical biological control of water hyacinth in South Africa has been constrained by cool winter temperatures that limit population growth of the biological control agents, and highly eutrophic waters which enhance plant growth. However, inundative releases of the control agent, Megamelus scutellaris (Hemiptera: Delphacidae), at the Hartbeespoort Dam, South Africa, suggest that water hyacinth can be managed successfully using biological control as a standalone intervention for the first time in the absence of herbicide operations, despite eutrophication and a temperate climate. Sentinel-2 satellite images were used to measure the reduction in water hyacinth cover from over 37% to less than 6% over two consecutive years since M. scutellaris was first released on the dam in 2018, while site surveys confirmed a corresponding increase in M. scutellaris population density from fewer than 500 insects/m2 in October 2019, to more than 6000 insects/m2 by March 2020. Inundative release strategies are recommended for the control of water hyacinth in South Africa at key stages of its invasion, particularly after winter, and flooding events.
- Full Text:
- Date Issued: 2022
Landscape drivers of mammal habitat use and richness in a protected area and its surrounding agricultural lands
- Bellón, Beatriz, Henry, Dominic AW, Renaud, Pierre-Cyril, Roque, Fabio de O, Santos, Cyntia Cavalcante, Melo, Isabel, Arvor, Damien, de Vos, Alta
- Authors: Bellón, Beatriz , Henry, Dominic AW , Renaud, Pierre-Cyril , Roque, Fabio de O , Santos, Cyntia Cavalcante , Melo, Isabel , Arvor, Damien , de Vos, Alta
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/415873 , vital:71296 , xlink:href="https://doi.org/10.1016/j.agee.2022.107989"
- Description: Protected areas (PAs) are key to conserving biodiversity and ecosystem services globally, but their effectiveness increasingly depends on the ability of the surrounding agricultural areas to support biodiversity and secure connectivity at the landscape level. This requires monitoring the broader multi-use landscapes in which PAs exist and identifying the landscape characteristics that support rich, functional wildlife communities. Here, we investigated the species richness and habitat use patterns of a mammal community in relation to different landscape variables and land use and land cover (LULC) types in a PA and its surrounding agricultural lands in the Cerrado. We first used a hierarchical multi-species occupancy model with input camera trap data and eight landscape variables (vegetation productivity, phenology, and heterogeneity, distance to water, roads and settlements, and the PA, slope, and elevation) to estimate the species richness and habitat use of 29 mammal species across the landscape. We then analyzed the relationships between the species richness and habitat use and the landscape variables at the site level, as well as the distribution of species at the landscape level in relation to the different natural and agricultural LULC types.
- Full Text:
- Date Issued: 2022
- Authors: Bellón, Beatriz , Henry, Dominic AW , Renaud, Pierre-Cyril , Roque, Fabio de O , Santos, Cyntia Cavalcante , Melo, Isabel , Arvor, Damien , de Vos, Alta
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/415873 , vital:71296 , xlink:href="https://doi.org/10.1016/j.agee.2022.107989"
- Description: Protected areas (PAs) are key to conserving biodiversity and ecosystem services globally, but their effectiveness increasingly depends on the ability of the surrounding agricultural areas to support biodiversity and secure connectivity at the landscape level. This requires monitoring the broader multi-use landscapes in which PAs exist and identifying the landscape characteristics that support rich, functional wildlife communities. Here, we investigated the species richness and habitat use patterns of a mammal community in relation to different landscape variables and land use and land cover (LULC) types in a PA and its surrounding agricultural lands in the Cerrado. We first used a hierarchical multi-species occupancy model with input camera trap data and eight landscape variables (vegetation productivity, phenology, and heterogeneity, distance to water, roads and settlements, and the PA, slope, and elevation) to estimate the species richness and habitat use of 29 mammal species across the landscape. We then analyzed the relationships between the species richness and habitat use and the landscape variables at the site level, as well as the distribution of species at the landscape level in relation to the different natural and agricultural LULC types.
- Full Text:
- Date Issued: 2022
Lessons from bright-spots for advancing knowledge exchange at the interface of marine science and policy
- Karcher, Denis B, Cvitanovic, Christopher, van Putten, Ingrid E, Colvin, Rebecca M, Armitage, Derek, Aswani, Shankar, Ballesteros, Marta, Ban, Natalie, Barragán-Paladines, María José, Bednarek, Angela, Bell, Johann D, Brooks, Cassandra M, Daw, Tim M, De la Cruz-Modino, Raquel, Francis, Tessa B, Fulton, Elizabeth A, Hobday, Alistair J, Holcer, Draško, Hudson, Charlotte, Jennerjahn, Tim C, Kinney, Aimee, Knol-Kauffman, Maaike, Löf, Marie F, Lopes, Priscila F, Mackelworth, Peter C, McQuatters-Gollop, Abigail, Muhl, Ella-Kari, Neihapi, Pita, Pascual-Fernández, José J, Posner, Stephpen M, Runhaar, Hens, Sainsbury, Keith, Sander, Gunnar, Steenbergen, Dirk J, Tuda, Paul M, Whiteman, Elizabeth, Zhang, Jialin
- Authors: Karcher, Denis B , Cvitanovic, Christopher , van Putten, Ingrid E , Colvin, Rebecca M , Armitage, Derek , Aswani, Shankar , Ballesteros, Marta , Ban, Natalie , Barragán-Paladines, María José , Bednarek, Angela , Bell, Johann D , Brooks, Cassandra M , Daw, Tim M , De la Cruz-Modino, Raquel , Francis, Tessa B , Fulton, Elizabeth A , Hobday, Alistair J , Holcer, Draško , Hudson, Charlotte , Jennerjahn, Tim C , Kinney, Aimee , Knol-Kauffman, Maaike , Löf, Marie F , Lopes, Priscila F , Mackelworth, Peter C , McQuatters-Gollop, Abigail , Muhl, Ella-Kari , Neihapi, Pita , Pascual-Fernández, José J , Posner, Stephpen M , Runhaar, Hens , Sainsbury, Keith , Sander, Gunnar , Steenbergen, Dirk J , Tuda, Paul M , Whiteman, Elizabeth , Zhang, Jialin
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/391378 , vital:68647 , xlink:href="https://doi.org/10.1016/j.jenvman.2022.114994"
- Description: Evidence-informed decision-making is in increasing demand given growing pressures on marine environments. A way to facilitate this is by knowledge exchange among marine scientists and decision-makers. While many barriers are reported in the literature, there are also examples whereby research has successfully informed marine decision-making (i.e., ‘bright-spots’). Here, we identify and analyze 25 bright-spots from a wide range of marine fields, contexts, and locations to provide insights into how to improve knowledge exchange at the interface of marine science and policy. Through qualitative surveys we investigate what initiated the bright-spots, their goals, and approaches to knowledge exchange. We also seek to identify what outcomes/impacts have been achieved, the enablers of success, and what lessons can be learnt to guide future knowledge exchange efforts. Results show that a diversity of approaches were used for knowledge exchange, from consultative engagement to genuine knowledge co-production. We show that diverse successes at the interface of marine science and policy are achievable and include impacts on policy, people, and governance. Such successes were enabled by factors related to the actors, processes, support, context, and timing. For example, the importance of involving diverse actors and managing positive relationships is a key lesson for success. However, enabling routine success will require: 1) transforming the ways in which we train scientists to include a greater focus on interpersonal skills, 2) institutionalizing and supporting knowledge exchange activities in organizational agendas, 3) conceptualizing and implementing broader research impact metrics, and 4) transforming funding mechanisms to focus on need-based interventions, impact planning, and an acknowledgement of the required time and effort that underpin knowledge exchange activities.
- Full Text:
- Date Issued: 2022
- Authors: Karcher, Denis B , Cvitanovic, Christopher , van Putten, Ingrid E , Colvin, Rebecca M , Armitage, Derek , Aswani, Shankar , Ballesteros, Marta , Ban, Natalie , Barragán-Paladines, María José , Bednarek, Angela , Bell, Johann D , Brooks, Cassandra M , Daw, Tim M , De la Cruz-Modino, Raquel , Francis, Tessa B , Fulton, Elizabeth A , Hobday, Alistair J , Holcer, Draško , Hudson, Charlotte , Jennerjahn, Tim C , Kinney, Aimee , Knol-Kauffman, Maaike , Löf, Marie F , Lopes, Priscila F , Mackelworth, Peter C , McQuatters-Gollop, Abigail , Muhl, Ella-Kari , Neihapi, Pita , Pascual-Fernández, José J , Posner, Stephpen M , Runhaar, Hens , Sainsbury, Keith , Sander, Gunnar , Steenbergen, Dirk J , Tuda, Paul M , Whiteman, Elizabeth , Zhang, Jialin
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/391378 , vital:68647 , xlink:href="https://doi.org/10.1016/j.jenvman.2022.114994"
- Description: Evidence-informed decision-making is in increasing demand given growing pressures on marine environments. A way to facilitate this is by knowledge exchange among marine scientists and decision-makers. While many barriers are reported in the literature, there are also examples whereby research has successfully informed marine decision-making (i.e., ‘bright-spots’). Here, we identify and analyze 25 bright-spots from a wide range of marine fields, contexts, and locations to provide insights into how to improve knowledge exchange at the interface of marine science and policy. Through qualitative surveys we investigate what initiated the bright-spots, their goals, and approaches to knowledge exchange. We also seek to identify what outcomes/impacts have been achieved, the enablers of success, and what lessons can be learnt to guide future knowledge exchange efforts. Results show that a diversity of approaches were used for knowledge exchange, from consultative engagement to genuine knowledge co-production. We show that diverse successes at the interface of marine science and policy are achievable and include impacts on policy, people, and governance. Such successes were enabled by factors related to the actors, processes, support, context, and timing. For example, the importance of involving diverse actors and managing positive relationships is a key lesson for success. However, enabling routine success will require: 1) transforming the ways in which we train scientists to include a greater focus on interpersonal skills, 2) institutionalizing and supporting knowledge exchange activities in organizational agendas, 3) conceptualizing and implementing broader research impact metrics, and 4) transforming funding mechanisms to focus on need-based interventions, impact planning, and an acknowledgement of the required time and effort that underpin knowledge exchange activities.
- Full Text:
- Date Issued: 2022
Lessons from COVID-19 for wildlife ranching in a changing world
- Clements, Hayley S, Child, Matthew F, Lindeque, Lehman, Lunderstedt, Kyra, de Vos, Alta
- Authors: Clements, Hayley S , Child, Matthew F , Lindeque, Lehman , Lunderstedt, Kyra , de Vos, Alta
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/415886 , vital:71297 , xlink:href="https://doi.org/10.1038/s41893-022-00961-1"
- Description: The COVID-19 pandemic provided an opportunity to assess the impacts of a global disturbance on conservation land uses and learn from responses to the crisis to enable more resilient conservation systems. To understand socio-economic responses of diverse wildlife working lands to COVID-19, we surveyed owners and managers of 78 private wildlife ranches (wildlife working lands), 23 agricultural farms (conventional working lands) and six public protected areas (conventional conservation lands) in South Africa. Most protected areas lost more than 75% of their revenues during 2020, while most agricultural farms lost less than 10%. The impact on wildlife ranches was more varied. Ranches with more diverse activities, particularly mixed wildlife–agriculture systems, lost less revenue, shifting their activities from those heavily impacted (international ecotourism, trophy hunting) to those less afected (for example, wildlife meat, livestock). This adaptive capacity suggests that wildlife-based enterprises could represent key ecosystem-based adaptations, providing lessons for integrated global policies that seek to incorporate private land models in the 2030 Biodiversity Framework.
- Full Text:
- Date Issued: 2022
- Authors: Clements, Hayley S , Child, Matthew F , Lindeque, Lehman , Lunderstedt, Kyra , de Vos, Alta
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/415886 , vital:71297 , xlink:href="https://doi.org/10.1038/s41893-022-00961-1"
- Description: The COVID-19 pandemic provided an opportunity to assess the impacts of a global disturbance on conservation land uses and learn from responses to the crisis to enable more resilient conservation systems. To understand socio-economic responses of diverse wildlife working lands to COVID-19, we surveyed owners and managers of 78 private wildlife ranches (wildlife working lands), 23 agricultural farms (conventional working lands) and six public protected areas (conventional conservation lands) in South Africa. Most protected areas lost more than 75% of their revenues during 2020, while most agricultural farms lost less than 10%. The impact on wildlife ranches was more varied. Ranches with more diverse activities, particularly mixed wildlife–agriculture systems, lost less revenue, shifting their activities from those heavily impacted (international ecotourism, trophy hunting) to those less afected (for example, wildlife meat, livestock). This adaptive capacity suggests that wildlife-based enterprises could represent key ecosystem-based adaptations, providing lessons for integrated global policies that seek to incorporate private land models in the 2030 Biodiversity Framework.
- Full Text:
- Date Issued: 2022
Light-driven antimicrobial therapy of palladium porphyrins and their chitosan immobilization derivatives and their photophysical-chemical properties
- Sen, Pinar, Soy, Rodah, Mgidlana, Sithi, Mack, John, Nyokong, Tebello
- Authors: Sen, Pinar , Soy, Rodah , Mgidlana, Sithi , Mack, John , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300112 , vital:57894 , xlink:href="https://doi.org/10.1016/j.dyepig.2022.110313"
- Description: The emergence of antimicrobial resistance has made the development of photodynamic therapy (PDT) related applications essential, since microorganisms can not form resistance to this method. Porphyrins are well-known photosensitizers for PDT related applications. Thus, the present study outlines the synthesis, characterization and evaluation of the utility of palladium porphyrins and their chitosan inclusion complexes as photosensitizer dye in photodynamic antimicrobial therapy (PACT). Before in vitro cell studies, the photophysical-chemical studies of all obtained structures were performed in solution. It was observed that the immobilization of the porphyrins into the chitosan influenced the photophysical-chemical and PACT activity properties. The determined fluorescence quantum yield was very low, in the range of 0.007–0.028 for all samples indicating the efficient triplet state population to cause high singlet oxygen quantum yield (ΦΔ). The measured ΦΔ values were in the range of 0.51–0.61 for the porphyrins and 0.53–0.66 for porphyrin chitosan immobilization complexes. Our results demonstrate that the PACT activity of cationic porphyrin (P3) and its chitosan immobilization form (P3-Ct) were more efficient in decreasing the number of viable cells up to 100% in vitro.
- Full Text:
- Date Issued: 2022
- Authors: Sen, Pinar , Soy, Rodah , Mgidlana, Sithi , Mack, John , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300112 , vital:57894 , xlink:href="https://doi.org/10.1016/j.dyepig.2022.110313"
- Description: The emergence of antimicrobial resistance has made the development of photodynamic therapy (PDT) related applications essential, since microorganisms can not form resistance to this method. Porphyrins are well-known photosensitizers for PDT related applications. Thus, the present study outlines the synthesis, characterization and evaluation of the utility of palladium porphyrins and their chitosan inclusion complexes as photosensitizer dye in photodynamic antimicrobial therapy (PACT). Before in vitro cell studies, the photophysical-chemical studies of all obtained structures were performed in solution. It was observed that the immobilization of the porphyrins into the chitosan influenced the photophysical-chemical and PACT activity properties. The determined fluorescence quantum yield was very low, in the range of 0.007–0.028 for all samples indicating the efficient triplet state population to cause high singlet oxygen quantum yield (ΦΔ). The measured ΦΔ values were in the range of 0.51–0.61 for the porphyrins and 0.53–0.66 for porphyrin chitosan immobilization complexes. Our results demonstrate that the PACT activity of cationic porphyrin (P3) and its chitosan immobilization form (P3-Ct) were more efficient in decreasing the number of viable cells up to 100% in vitro.
- Full Text:
- Date Issued: 2022
Livestock ecosystem services and disservices in a medium-sized South African town
- Thondhlana, Gladman, Papama, Yose, Cockburn, Jessica J, Shackleton, Charlie M
- Authors: Thondhlana, Gladman , Papama, Yose , Cockburn, Jessica J , Shackleton, Charlie M
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/403241 , vital:69937 , xlink:href="https://doi.org/10.1080/26395916.2021.2019833"
- Description: Production of livestock in urban spaces is a common phenomenon globally, particularly in the Global South. Livestock provides multiple benefits to society yet its production in urban spaces can result in adverse impacts to residents that can trigger conflicts. Understanding of the ecosystem services and disservices of livestock from the perspectives of residents can inform inclusive local management plans. Using household surveys and key informant interviews, this study sought to examine the contribution of livestock to owners, and perceptions of livestock services and disservices among non-livestock owners and key informants in Makhanda, a medium-sized South African town. Livestock owners derived multiple benefits from their livestock, including provisioning services such as meat, milk, skins and draught, and use livestock and livestock products in cultural activities such as rituals, bride price payments and funerals that are key elements of local identity. Among residents, there were marked differences in perceptions on the services and disservices of livestock which points to potential conflicts over urban land use and the need for addressing trade-offs. A key trade-off for local municipal authorities is addressing hunger and poverty by supporting well-regulated urban livestock production versus managing potential livestock disservices such as injuries to humans, livestock-vehicle collisions, health hazards and damage to urban green infrastructure. The trade-offs should be understood and considered by local authorities and residents as a basis for collectively developing strategies that can integrate livelihoods and cultural realities to balance competing demands for urban spaces including livestock production and other uses.
- Full Text:
- Date Issued: 2022
- Authors: Thondhlana, Gladman , Papama, Yose , Cockburn, Jessica J , Shackleton, Charlie M
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/403241 , vital:69937 , xlink:href="https://doi.org/10.1080/26395916.2021.2019833"
- Description: Production of livestock in urban spaces is a common phenomenon globally, particularly in the Global South. Livestock provides multiple benefits to society yet its production in urban spaces can result in adverse impacts to residents that can trigger conflicts. Understanding of the ecosystem services and disservices of livestock from the perspectives of residents can inform inclusive local management plans. Using household surveys and key informant interviews, this study sought to examine the contribution of livestock to owners, and perceptions of livestock services and disservices among non-livestock owners and key informants in Makhanda, a medium-sized South African town. Livestock owners derived multiple benefits from their livestock, including provisioning services such as meat, milk, skins and draught, and use livestock and livestock products in cultural activities such as rituals, bride price payments and funerals that are key elements of local identity. Among residents, there were marked differences in perceptions on the services and disservices of livestock which points to potential conflicts over urban land use and the need for addressing trade-offs. A key trade-off for local municipal authorities is addressing hunger and poverty by supporting well-regulated urban livestock production versus managing potential livestock disservices such as injuries to humans, livestock-vehicle collisions, health hazards and damage to urban green infrastructure. The trade-offs should be understood and considered by local authorities and residents as a basis for collectively developing strategies that can integrate livelihoods and cultural realities to balance competing demands for urban spaces including livestock production and other uses.
- Full Text:
- Date Issued: 2022
Low-Symmetry Phthalocyanines Bearing Carboxy-Groups
- Bunin, Dmitry A, Ndebele, Nobuhle, Martynov, Alexander G, Mack, John, Gorbunova, Yulia G, Nyokong, Tebello
- Authors: Bunin, Dmitry A , Ndebele, Nobuhle , Martynov, Alexander G , Mack, John , Gorbunova, Yulia G , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/231262 , vital:49870 , xlink:href="https://doi.org/10.3390/molecules27020524" "
- Description: The synthesis and characterization of A3B-type phthalocyanines, ZnPc1–4, bearing bulky 2,6-diisopropylphenoxy-groups or chlorine atoms on isoindoline units “A” and either one or two carboxylic anchors on isoindoline unit “B” are reported. A comparison of molecular modelling with the conventional time dependent—density functional theory (TD-DFT) approach and its simplified sTD-DFT approximation provides further evidence that the latter method accurately reproduces the key trends in the spectral properties, providing colossal savings in computer time for quite large molecules. This demonstrates that it is a valuable tool for guiding the rational design of new phthalocyanines for practical applications.
- Full Text:
- Date Issued: 2022
- Authors: Bunin, Dmitry A , Ndebele, Nobuhle , Martynov, Alexander G , Mack, John , Gorbunova, Yulia G , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/231262 , vital:49870 , xlink:href="https://doi.org/10.3390/molecules27020524" "
- Description: The synthesis and characterization of A3B-type phthalocyanines, ZnPc1–4, bearing bulky 2,6-diisopropylphenoxy-groups or chlorine atoms on isoindoline units “A” and either one or two carboxylic anchors on isoindoline unit “B” are reported. A comparison of molecular modelling with the conventional time dependent—density functional theory (TD-DFT) approach and its simplified sTD-DFT approximation provides further evidence that the latter method accurately reproduces the key trends in the spectral properties, providing colossal savings in computer time for quite large molecules. This demonstrates that it is a valuable tool for guiding the rational design of new phthalocyanines for practical applications.
- Full Text:
- Date Issued: 2022
Male Peer Talk About Menstruation: Discursively Bolstering Hegemonic Masculinities Among Young Men in South Africa
- Macleod, Catriona I, Glover, Jonothan M, Makusem, Manase, Kelland, Lindsay, Paphitis, Sharli A
- Authors: Macleod, Catriona I , Glover, Jonothan M , Makusem, Manase , Kelland, Lindsay , Paphitis, Sharli A
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426502 , vital:72358 , 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:
- Date Issued: 2022
- Authors: Macleod, Catriona I , Glover, Jonothan M , Makusem, Manase , Kelland, Lindsay , Paphitis, Sharli A
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426502 , vital:72358 , 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:
- Date Issued: 2022
Marine robots for coastal ocean research in the Western Indian Ocean
- Palmer, Matthew R, Shagude, Yohana W, Roberts, Michael J, Popva, Ekaterina, Wihsgott, Juliane U, Aswani, Shankar, Coupland, Jack, Howe, John A, Bett, Brian J, Osuka, Kennedy E, Abernethy, Colin, Alexiou, Sofia, Painter, Stuart C, Kamau, Joseph N, Nyandwi, Ntahondi, Sekadende, Baraka
- Authors: Palmer, Matthew R , Shagude, Yohana W , Roberts, Michael J , Popva, Ekaterina , Wihsgott, Juliane U , Aswani, Shankar , Coupland, Jack , Howe, John A , Bett, Brian J , Osuka, Kennedy E , Abernethy, Colin , Alexiou, Sofia , Painter, Stuart C , Kamau, Joseph N , Nyandwi, Ntahondi , Sekadende, Baraka
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/403445 , vital:69962 , xlink:href="https://hdl.handle.net/10520/ejc-cristal-v10-n1-a7"
- Description: Marine robots have the potential to enhance WIO marine research to improve regional adaptation to the challenges presented by climate change by providing enhanced research capacity that bypasses the requirement for expensive infrastructure, such as large research vessels. This paper tests this potential and assesses the readiness of WIO communities to adopt autonomous technologies to meet its marine research priorities. We apply a range of analyses to a marine robots case study undertaken in waters around the island of Pemba, part of the Zanzibar archipelago, in Tanzania in 2019. The campaign formed part of a multinational project focused on increasing WIO capacity to meet food security and ocean sustainability challenges. A community engagement programme with six Tanzanian coastal communities resulted in positive changes in attitudes towards marine robots with reported increases in understanding and acceptance of such technologies. Suspicion of the robots was reduced and a lower risk of removing operational equipment was recorded following the provision of educational material. Cost, risk and benefit analysis shows that marine robots are perceived to provide high level benefits, but come at a high cost that is difficult to achieve using national or regional funding. An assessment of the capacity of WIO marine institutes to adopt such technologies shows that prior to this work, few skills or infrastructure related to marine robots were available to researchers and further confirmed that funding opportunities were perceived to be largely unavailable at institutional, national, regional or international levels. Responses from regional partners following completion of the case study however, revealed an uplift in perceived capacity, particularly related to access to infrastructure and expertise as well as support and opportunities for funding at each level. The presented case study is shown to have been a valuable demonstrator of the benefits of using marine robots to meet WIO coastal ocean research requirements and regional capacity was shown to be substantially increased within the broad range of marine institutes surveyed throughout the case study period. This study demonstrates that taking early steps towards adopting marine autonomous robots has increased WIO regional marine research capacity and increased the confidence and willingness of local researchers to seek alternative solutions to ongoing marine research challenges. Recommendations for future action that will continue to increase the capacity and readiness for regional adoption of marine robots include investment at local, national and regional levels to provide accessible training opportunities and to facilitate regional and international collaborations; investment in a regional hub, or centre of excellence for marine robotic technology; early adoption of newly emerging smaller, cheaper autonomous technologies; investment in local skills and support facilities to aid local buy-in and acceptance while supporting regional capacity.
- Full Text:
- Date Issued: 2022
- Authors: Palmer, Matthew R , Shagude, Yohana W , Roberts, Michael J , Popva, Ekaterina , Wihsgott, Juliane U , Aswani, Shankar , Coupland, Jack , Howe, John A , Bett, Brian J , Osuka, Kennedy E , Abernethy, Colin , Alexiou, Sofia , Painter, Stuart C , Kamau, Joseph N , Nyandwi, Ntahondi , Sekadende, Baraka
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/403445 , vital:69962 , xlink:href="https://hdl.handle.net/10520/ejc-cristal-v10-n1-a7"
- Description: Marine robots have the potential to enhance WIO marine research to improve regional adaptation to the challenges presented by climate change by providing enhanced research capacity that bypasses the requirement for expensive infrastructure, such as large research vessels. This paper tests this potential and assesses the readiness of WIO communities to adopt autonomous technologies to meet its marine research priorities. We apply a range of analyses to a marine robots case study undertaken in waters around the island of Pemba, part of the Zanzibar archipelago, in Tanzania in 2019. The campaign formed part of a multinational project focused on increasing WIO capacity to meet food security and ocean sustainability challenges. A community engagement programme with six Tanzanian coastal communities resulted in positive changes in attitudes towards marine robots with reported increases in understanding and acceptance of such technologies. Suspicion of the robots was reduced and a lower risk of removing operational equipment was recorded following the provision of educational material. Cost, risk and benefit analysis shows that marine robots are perceived to provide high level benefits, but come at a high cost that is difficult to achieve using national or regional funding. An assessment of the capacity of WIO marine institutes to adopt such technologies shows that prior to this work, few skills or infrastructure related to marine robots were available to researchers and further confirmed that funding opportunities were perceived to be largely unavailable at institutional, national, regional or international levels. Responses from regional partners following completion of the case study however, revealed an uplift in perceived capacity, particularly related to access to infrastructure and expertise as well as support and opportunities for funding at each level. The presented case study is shown to have been a valuable demonstrator of the benefits of using marine robots to meet WIO coastal ocean research requirements and regional capacity was shown to be substantially increased within the broad range of marine institutes surveyed throughout the case study period. This study demonstrates that taking early steps towards adopting marine autonomous robots has increased WIO regional marine research capacity and increased the confidence and willingness of local researchers to seek alternative solutions to ongoing marine research challenges. Recommendations for future action that will continue to increase the capacity and readiness for regional adoption of marine robots include investment at local, national and regional levels to provide accessible training opportunities and to facilitate regional and international collaborations; investment in a regional hub, or centre of excellence for marine robotic technology; early adoption of newly emerging smaller, cheaper autonomous technologies; investment in local skills and support facilities to aid local buy-in and acceptance while supporting regional capacity.
- Full Text:
- Date Issued: 2022
Measuring discrimination experienced by people with a mental illness
- Brohan, Elaine, Thornicroft, Graham, Rüsch, Nicolas, Lasalvia, Antonio, Campbell, Megan, Yalçınkaya-Alkar, Özden, Lanfredi, Mariangela, Ochoa, Susana, Üçok, Alp, Tomás, Catarina, Fadipe, Babatunde, Sebes, Julia, Fiorillo, Andrea, Sampogna, Gaia, Paula, Cristiane Silvestre, Valverde, Leonadis, Schomerus, Georg, Klemm, Pia, Ouali, Uta, Castelein, Stynke, Alexová, Aneta, Oexle, Nathalie, Guimarães, Patrícia Neves, Sportel, Bouwina Esther, Chang, Chih-Cheng, Li, Jie, Shanthi, Chilasagaram, Reneses, Blanca, Bakolis, Ioannis, Evans-Lacko, Sarah
- Authors: Brohan, Elaine , Thornicroft, Graham , Rüsch, Nicolas , Lasalvia, Antonio , Campbell, Megan , Yalçınkaya-Alkar, Özden , Lanfredi, Mariangela , Ochoa, Susana , Üçok, Alp , Tomás, Catarina , Fadipe, Babatunde , Sebes, Julia , Fiorillo, Andrea , Sampogna, Gaia , Paula, Cristiane Silvestre , Valverde, Leonadis , Schomerus, Georg , Klemm, Pia , Ouali, Uta , Castelein, Stynke , Alexová, Aneta , Oexle, Nathalie , Guimarães, Patrícia Neves , Sportel, Bouwina Esther , Chang, Chih-Cheng , Li, Jie , Shanthi, Chilasagaram , Reneses, Blanca , Bakolis, Ioannis , Evans-Lacko, Sarah
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/302498 , vital:58202 , xlink:href="https://doi.org/10.1017/S0033291722000630"
- Description: Background: The Discrimination and Stigma Scale (DISC) is a patient-reported outcome measure which assesses experiences of discrimination among persons with a mental illness globally. Methods: This study evaluated whether the psychometric properties of a short-form version, DISC-Ultra Short (DISCUS) (11-item), could be replicated in a sample of people with a wide range of mental disorders from 21 sites in 15 countries/territories, across six global regions. The frequency of experienced discrimination was reported. Scaling assumptions (confirmatory factor analysis, inter-item and item-total correlations), reliability (internal consistency) and validity (convergent validity, known groups method) were investigated in each region, and by diagnosis group. Results: 1195 people participated. The most frequently reported experiences of discrimination were being shunned or avoided at work (48.7%) and discrimination in making or keeping friends (47.2%). Confirmatory factor analysis supported a unidimensional model across all six regions and five diagnosis groups. Convergent validity was confirmed in the total sample and within all regions [ Internalised Stigma of Mental Illness (ISMI-10): 0.28–0.67, stopping self: 0.54–0.72, stigma consciousness: −0.32–0.57], as was internal consistency reliability (α = 0.74–0.84). Known groups validity was established in the global sample with levels of experienced discrimination significantly higher for those experiencing higher depression [Patient Health Questionnaire (PHQ)-2: p more than 0.001], lower mental wellbeing [Warwick-Edinburgh Well-being Scale (WEMWBS): p is less than 0.001], higher suicidal ideation [Beck Hopelessness Scale (BHS)-4: p is less than 0.001] and higher risk of suicidal behaviour [Suicidal Ideation Attributes Scale (SIDAS): p is less than 0.001]. Conclusions: The DISCUS is a reliable and valid unidimensional measure of experienced discrimination for use in global settings with similar properties to the longer DISC. It offers a brief assessment of experienced discrimination for use in clinical and research settings.
- Full Text:
- Date Issued: 2022
- Authors: Brohan, Elaine , Thornicroft, Graham , Rüsch, Nicolas , Lasalvia, Antonio , Campbell, Megan , Yalçınkaya-Alkar, Özden , Lanfredi, Mariangela , Ochoa, Susana , Üçok, Alp , Tomás, Catarina , Fadipe, Babatunde , Sebes, Julia , Fiorillo, Andrea , Sampogna, Gaia , Paula, Cristiane Silvestre , Valverde, Leonadis , Schomerus, Georg , Klemm, Pia , Ouali, Uta , Castelein, Stynke , Alexová, Aneta , Oexle, Nathalie , Guimarães, Patrícia Neves , Sportel, Bouwina Esther , Chang, Chih-Cheng , Li, Jie , Shanthi, Chilasagaram , Reneses, Blanca , Bakolis, Ioannis , Evans-Lacko, Sarah
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/302498 , vital:58202 , xlink:href="https://doi.org/10.1017/S0033291722000630"
- Description: Background: The Discrimination and Stigma Scale (DISC) is a patient-reported outcome measure which assesses experiences of discrimination among persons with a mental illness globally. Methods: This study evaluated whether the psychometric properties of a short-form version, DISC-Ultra Short (DISCUS) (11-item), could be replicated in a sample of people with a wide range of mental disorders from 21 sites in 15 countries/territories, across six global regions. The frequency of experienced discrimination was reported. Scaling assumptions (confirmatory factor analysis, inter-item and item-total correlations), reliability (internal consistency) and validity (convergent validity, known groups method) were investigated in each region, and by diagnosis group. Results: 1195 people participated. The most frequently reported experiences of discrimination were being shunned or avoided at work (48.7%) and discrimination in making or keeping friends (47.2%). Confirmatory factor analysis supported a unidimensional model across all six regions and five diagnosis groups. Convergent validity was confirmed in the total sample and within all regions [ Internalised Stigma of Mental Illness (ISMI-10): 0.28–0.67, stopping self: 0.54–0.72, stigma consciousness: −0.32–0.57], as was internal consistency reliability (α = 0.74–0.84). Known groups validity was established in the global sample with levels of experienced discrimination significantly higher for those experiencing higher depression [Patient Health Questionnaire (PHQ)-2: p more than 0.001], lower mental wellbeing [Warwick-Edinburgh Well-being Scale (WEMWBS): p is less than 0.001], higher suicidal ideation [Beck Hopelessness Scale (BHS)-4: p is less than 0.001] and higher risk of suicidal behaviour [Suicidal Ideation Attributes Scale (SIDAS): p is less than 0.001]. Conclusions: The DISCUS is a reliable and valid unidimensional measure of experienced discrimination for use in global settings with similar properties to the longer DISC. It offers a brief assessment of experienced discrimination for use in clinical and research settings.
- Full Text:
- Date Issued: 2022
Neoliberalism’s conditioning effects on the university and the example of proctoring during COVID-19 and since
- Authors: McKenna, Sioux
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426929 , vital:72401 , xlink:href="https://doi.org/10.1080/14767430.2022.2100612"
- Description: Neoliberalism has shaped the academy in ways that constrain its potential as a public good. Neoliberalism is based on the assumption that, by submitting to the so-called neutral forces of the market, wealth can be created alongside the achievement of equality and efficiency. Although this assumption is demonstrably false, neoliberalism remains politically powerful. As an example, this article discusses how neoliberalism has enabled the rapid uptake of proctoring software during the covid pandemic and since. ‘Proctoring' is the online monitoring of students’ behaviour as they sit for exams. Many within the academy consider proctoring software to be dehumanizing – essentially legalized spyware. They argue that the software invades privacy and is inherently racist and ableist, amongst other things. It is hoped that by understanding how structural forces such as neoliberalism affect both our agency and university activities, frequently against the common good, strategies can be developed to change these structures.
- Full Text:
- Date Issued: 2022
- Authors: McKenna, Sioux
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426929 , vital:72401 , xlink:href="https://doi.org/10.1080/14767430.2022.2100612"
- Description: Neoliberalism has shaped the academy in ways that constrain its potential as a public good. Neoliberalism is based on the assumption that, by submitting to the so-called neutral forces of the market, wealth can be created alongside the achievement of equality and efficiency. Although this assumption is demonstrably false, neoliberalism remains politically powerful. As an example, this article discusses how neoliberalism has enabled the rapid uptake of proctoring software during the covid pandemic and since. ‘Proctoring' is the online monitoring of students’ behaviour as they sit for exams. Many within the academy consider proctoring software to be dehumanizing – essentially legalized spyware. They argue that the software invades privacy and is inherently racist and ableist, amongst other things. It is hoped that by understanding how structural forces such as neoliberalism affect both our agency and university activities, frequently against the common good, strategies can be developed to change these structures.
- Full Text:
- Date Issued: 2022
Not there yet: knowledge building in educational development ten years on
- Authors: Boughey, Chrissie
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426954 , vital:72403 , xlink:href="https://doi.org/10.1080/13562517.2022.2121158"
- Description: This paper responds to a question posed by [Shay, Suellen. 2012. “Educational Development as a Field: Are We There Yet?” Higher Education Research and Development 31 (3): 311–323. doii:10.1080/07294360.2011.631520] about the status of knowledge building in the field of Educational Development. In her paper, Shay critiques knowledge produced in the field arguing that it is ‘codified practice’ [Gamble, Jeanne. 2001. “Modelling the Invisible: The Pedagogy of Craft Apprenticeship.” Studies in Continuing Education 23 (2): 185–200. doii:10.1080/01580370120101957; Gamble, Jeanne. 2004. “Retrieving the General from the Particular: The Structure of Craft Knowledge.” In Reading Bernstein, Researching Bernstein, edited by J. Muller, B. Davies, and A. Morais, 189–203. Abingdon: Routledge; Gamble, Jeanne. 2006. “Theory and Practice in the Vocational Curriculum.” In Knowledge, Curriculum and Qualifications in South African Further Education, edited by M. Young and J. Gamble, 87–103. Pretoria: HSRC Press] rather than applied theory which could succeed in reconceptualising problems rather than simply trying to address them. This paper draws on a review of research produced in the field in recent years in South Africa to argue that, although some work does result in the reconceptualision of problems the higher education, it is limited in that (i) it has been produced by a relatively small group of practitioners located at a few universities and (ii) draws on theory developed in the Global North. The paper then proceeds to offer some tentative suggestions for the way future work aimed at knowledge building could proceed.
- Full Text:
- Date Issued: 2022
- Authors: Boughey, Chrissie
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426954 , vital:72403 , xlink:href="https://doi.org/10.1080/13562517.2022.2121158"
- Description: This paper responds to a question posed by [Shay, Suellen. 2012. “Educational Development as a Field: Are We There Yet?” Higher Education Research and Development 31 (3): 311–323. doii:10.1080/07294360.2011.631520] about the status of knowledge building in the field of Educational Development. In her paper, Shay critiques knowledge produced in the field arguing that it is ‘codified practice’ [Gamble, Jeanne. 2001. “Modelling the Invisible: The Pedagogy of Craft Apprenticeship.” Studies in Continuing Education 23 (2): 185–200. doii:10.1080/01580370120101957; Gamble, Jeanne. 2004. “Retrieving the General from the Particular: The Structure of Craft Knowledge.” In Reading Bernstein, Researching Bernstein, edited by J. Muller, B. Davies, and A. Morais, 189–203. Abingdon: Routledge; Gamble, Jeanne. 2006. “Theory and Practice in the Vocational Curriculum.” In Knowledge, Curriculum and Qualifications in South African Further Education, edited by M. Young and J. Gamble, 87–103. Pretoria: HSRC Press] rather than applied theory which could succeed in reconceptualising problems rather than simply trying to address them. This paper draws on a review of research produced in the field in recent years in South Africa to argue that, although some work does result in the reconceptualision of problems the higher education, it is limited in that (i) it has been produced by a relatively small group of practitioners located at a few universities and (ii) draws on theory developed in the Global North. The paper then proceeds to offer some tentative suggestions for the way future work aimed at knowledge building could proceed.
- Full Text:
- Date Issued: 2022
Novel cationic-chalcone phthalocyanines for photodynamic therapy eradication of S. aureus and E. coli bacterial biofilms and MCF-7 breast cancer
- Openda, Yolande Ikala, Babu, Balaji, Nyokong, Tebello
- Authors: Openda, Yolande Ikala , Babu, Balaji , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300129 , vital:57895 , xlink:href="https://doi.org/10.1016/j.pdpdt.2022.102863"
- Description: New tetrasubstituted zinc (II) and indium (III) phthalocyanines bearing dimethylamino chalcone group (complexes 3 and 4) as well as their quaternized analogs (3a and 4a) have been assessed for their photodynamic therapy (PDT) of cancer as well as photodynamic antimicrobial chemotherapy activities against biofilms and planktonic cultures of pathogenic bacteria of Staphylococcus aureus and Escherichia coli. Compared to the non-quaternized phthalocyanines 3 and 4, the cationic phthalocyanines 3a and 4a exhibit a higher photodynamic inactivation against the planktonic cells with log reduction values above 9 at a concentration of 1.25 µM. This was attributed to the positive charge which enhances cellular uptake. More interestingly, 3a and 4a show a higher photodynamic inactivation (less than 3% of S. aureus survived) on their biofilm counterparts thanks to their stronger affinity to these cells. 3a and 4a Pcs also exhibited interesting PDT activity against MCF-7 cancer cells giving IC50 values of 17.9 and 7.4 μM, respectively following 15 min irradiation. The obtained results in this work show that the positively charged phthalocyanines 3a and 4a are potential antibacterial photosensitizers that show some selectivity toward the Gram-positive and Gram-negative bacteria as well as MCF-7 breasts cancer cells.
- Full Text:
- Date Issued: 2022
- Authors: Openda, Yolande Ikala , Babu, Balaji , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300129 , vital:57895 , xlink:href="https://doi.org/10.1016/j.pdpdt.2022.102863"
- Description: New tetrasubstituted zinc (II) and indium (III) phthalocyanines bearing dimethylamino chalcone group (complexes 3 and 4) as well as their quaternized analogs (3a and 4a) have been assessed for their photodynamic therapy (PDT) of cancer as well as photodynamic antimicrobial chemotherapy activities against biofilms and planktonic cultures of pathogenic bacteria of Staphylococcus aureus and Escherichia coli. Compared to the non-quaternized phthalocyanines 3 and 4, the cationic phthalocyanines 3a and 4a exhibit a higher photodynamic inactivation against the planktonic cells with log reduction values above 9 at a concentration of 1.25 µM. This was attributed to the positive charge which enhances cellular uptake. More interestingly, 3a and 4a show a higher photodynamic inactivation (less than 3% of S. aureus survived) on their biofilm counterparts thanks to their stronger affinity to these cells. 3a and 4a Pcs also exhibited interesting PDT activity against MCF-7 cancer cells giving IC50 values of 17.9 and 7.4 μM, respectively following 15 min irradiation. The obtained results in this work show that the positively charged phthalocyanines 3a and 4a are potential antibacterial photosensitizers that show some selectivity toward the Gram-positive and Gram-negative bacteria as well as MCF-7 breasts cancer cells.
- Full Text:
- Date Issued: 2022
Photodegradation of ibuprofen using 5-10-15-20-tetrakis (4-bromophenyl) porphyrin conjugated to graphene quantum dots
- Magaela, Bridged N, Ndlovu, Knowledge S, Tshangana, Charmaine S, Muleia, Adoph A, Mamba, Bhekie B, Nyokong, Tebello, Managa, Muthumuni
- Authors: Magaela, Bridged N , Ndlovu, Knowledge S , Tshangana, Charmaine S , Muleia, Adoph A , Mamba, Bhekie B , Nyokong, Tebello , Managa, Muthumuni
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/304819 , vital:58493 , xlink:href="https://doi.org/10.1016/j.optmat.2022.113147"
- Description: Ibuprofen (IBU) is a common anti-inflammatory drug that is consumed by many individuals in the world. As such, analytical studies have detected high concentrations of the drug in many waterbodies, which poses a risk of harmful effects on the environment and public health. The hydroxyl radical technologies, a collective of techniques also known as advanced oxidation processes (AOPs), can be utilized to degrade this emerging pollutant. In this study, the photodegradation of ibuprofen using 5,10,15,20-tetrakis(4-bromophenyl) porphyrin conjugated to graphene quantum dots was investigated using a custom-built photoreactor. Three different concentrations of IBU (200, 300 and 500 μM) were utilized as initial concentrations. The pH of the IBU was varied between acidic (pH 3.0), natural (pH 5.0) and alkaline (pH 9.0) to note the effect on IBU degradation as a function of time. The Highest ФΔ was obtained for InTBrP- GDQs (ФΔ = 0.80), followed by InTBrP (ФΔ = 0.74). The photodegradation efficiency of the TBrP-GQDs and InTBrP-GQDs were determined to be 43.2 and 76.1% respectively.
- Full Text:
- Date Issued: 2022
- Authors: Magaela, Bridged N , Ndlovu, Knowledge S , Tshangana, Charmaine S , Muleia, Adoph A , Mamba, Bhekie B , Nyokong, Tebello , Managa, Muthumuni
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/304819 , vital:58493 , xlink:href="https://doi.org/10.1016/j.optmat.2022.113147"
- Description: Ibuprofen (IBU) is a common anti-inflammatory drug that is consumed by many individuals in the world. As such, analytical studies have detected high concentrations of the drug in many waterbodies, which poses a risk of harmful effects on the environment and public health. The hydroxyl radical technologies, a collective of techniques also known as advanced oxidation processes (AOPs), can be utilized to degrade this emerging pollutant. In this study, the photodegradation of ibuprofen using 5,10,15,20-tetrakis(4-bromophenyl) porphyrin conjugated to graphene quantum dots was investigated using a custom-built photoreactor. Three different concentrations of IBU (200, 300 and 500 μM) were utilized as initial concentrations. The pH of the IBU was varied between acidic (pH 3.0), natural (pH 5.0) and alkaline (pH 9.0) to note the effect on IBU degradation as a function of time. The Highest ФΔ was obtained for InTBrP- GDQs (ФΔ = 0.80), followed by InTBrP (ФΔ = 0.74). The photodegradation efficiency of the TBrP-GQDs and InTBrP-GQDs were determined to be 43.2 and 76.1% respectively.
- Full Text:
- Date Issued: 2022
Photodegradation of tetracycline by asymmetrical zinc (II) phthalocyanines conjugated to cobalt tungstate nanoparticles
- Mgidlana, Sithi, Sen, Pinar, Nyokong, Tebello
- Authors: Mgidlana, Sithi , Sen, Pinar , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300233 , vital:57908 , xlink:href="https://doi.org/10.1016/j.molstruc.2022.132938"
- Description: This work focused on syntheses of novel asymmetrically tetra substituted Zn phthalocyanines (ZnPc) each containing a single carboxyl group, with the other substituents bearing alkynyl (complex 1) and fluorine containing groups (complexes 2 and 3). The complexes were conjugated to cobalt tungstate nanoparticles and employed as efficient photocatalysts for degradation of tetracycline in water. ZnPc complexes and their conjugates showed good photophysical and photochemical properties behaviour with complex 1 giving higher triplet and singlet oxygen quantum yields compared to 2 and 3. Complex 1 showed higher activity towards the photodegradation of tetracycline compared to complexes 2 and 3, with higher kobs and initial rates for the former. The photocatalysis obeyed the Langmuir-Hinshelwood kinetic model.
- Full Text:
- Date Issued: 2022
- Authors: Mgidlana, Sithi , Sen, Pinar , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300233 , vital:57908 , xlink:href="https://doi.org/10.1016/j.molstruc.2022.132938"
- Description: This work focused on syntheses of novel asymmetrically tetra substituted Zn phthalocyanines (ZnPc) each containing a single carboxyl group, with the other substituents bearing alkynyl (complex 1) and fluorine containing groups (complexes 2 and 3). The complexes were conjugated to cobalt tungstate nanoparticles and employed as efficient photocatalysts for degradation of tetracycline in water. ZnPc complexes and their conjugates showed good photophysical and photochemical properties behaviour with complex 1 giving higher triplet and singlet oxygen quantum yields compared to 2 and 3. Complex 1 showed higher activity towards the photodegradation of tetracycline compared to complexes 2 and 3, with higher kobs and initial rates for the former. The photocatalysis obeyed the Langmuir-Hinshelwood kinetic model.
- Full Text:
- Date Issued: 2022
Photodynamic activity of novel cationic porphyrins conjugated to graphene quantum dots against Staphylococcus aureus
- Magaela, Bridged N, Makola, Lekgowa C, Managa, Muthumuni, Nyokong, Tebello
- Authors: Magaela, Bridged N , Makola, Lekgowa C , Managa, Muthumuni , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295797 , vital:57379 , xlink:href="https://doi.org/10.1142/S1088424622500316"
- Description: Novel 5-(pyridyl)-10-15-20-tris(4-bromophenyl) porphyrin (complex 1), indium metal derivative (complex 2), and quaternized derivative (complex 3) were synthesized and conjugated to graphene quantum dots (GQDs). The conjugation of the porphyrins to GQDs was through ππ-ππ stacking. Herein, the ππ-ππ stacking approach was used to avoid covalent conjugation which might compromise the intrinsic chemical and physical properties. The photodynamic activities of the proposed nanomaterials were assessed towards Staphylococcus aureus cell obliteration. The photophysical properties of the prepared complexes were also studied prior to the application. Moreover, a decrease in fluorescence lifetimes was observed upon metalation of complex 1. As anticipated, singlet oxygen quantum yield (ΦΔ)ΦΔ) increased notably upon heavy metal (indium) insertion and upon composite formation. Antimicrobial photodynamic therapy comparative studies were done on quaternized and unquaternized indium porphyrins conjugated to GQDs. Complex 3-GQDs exhibited the highest antibacterial activities compared to other complexes, and this was attributed to the high ΦΔΦΔ which plays an imperative role in photodynamic therapy applications.
- Full Text:
- Date Issued: 2022
- Authors: Magaela, Bridged N , Makola, Lekgowa C , Managa, Muthumuni , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295797 , vital:57379 , xlink:href="https://doi.org/10.1142/S1088424622500316"
- Description: Novel 5-(pyridyl)-10-15-20-tris(4-bromophenyl) porphyrin (complex 1), indium metal derivative (complex 2), and quaternized derivative (complex 3) were synthesized and conjugated to graphene quantum dots (GQDs). The conjugation of the porphyrins to GQDs was through ππ-ππ stacking. Herein, the ππ-ππ stacking approach was used to avoid covalent conjugation which might compromise the intrinsic chemical and physical properties. The photodynamic activities of the proposed nanomaterials were assessed towards Staphylococcus aureus cell obliteration. The photophysical properties of the prepared complexes were also studied prior to the application. Moreover, a decrease in fluorescence lifetimes was observed upon metalation of complex 1. As anticipated, singlet oxygen quantum yield (ΦΔ)ΦΔ) increased notably upon heavy metal (indium) insertion and upon composite formation. Antimicrobial photodynamic therapy comparative studies were done on quaternized and unquaternized indium porphyrins conjugated to GQDs. Complex 3-GQDs exhibited the highest antibacterial activities compared to other complexes, and this was attributed to the high ΦΔΦΔ which plays an imperative role in photodynamic therapy applications.
- Full Text:
- Date Issued: 2022
Photodynamic therapy activity of 5, 10, 15-tris (5-bromo-2-thienyl), 20 (phenylcarboxy) porphyrin conjugated to graphene quantum dot against MCF-7 breast cancer cells
- Makola, Lekgowa Collen, Nwahahra, Nnamdi, Managa, Muthumuni, Nyokong, Tebello
- Authors: Makola, Lekgowa Collen , Nwahahra, Nnamdi , Managa, Muthumuni , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300244 , vital:57909 , xlink:href="https://doi.org/10.1080/00958972.2022.2087515"
- Description: A novel 5,10,15-tris(5-bromo-2-thienyl),20(phenylcarboxy)porphyrin and its gallium derivative have been synthesized and fully characterized by various spectroscopic techniques and their respective photophysical and photochemical properties, such as the singlet oxygen quantum yield (ΦΔ), fluorescence quantum yield (ΦF) and triplet lifetime (τT) were determined. The complexes were conjugated to PEI_GQDs resulting is stable conjugates, owing to strong π–π stacking interaction between the PEI_GQDs and the porphyrins. PDT studies were carried out on these nanoconjugates and results obtained indicated they are suitable candidates for further in-depth PDT studies.
- Full Text:
- Date Issued: 2022
- Authors: Makola, Lekgowa Collen , Nwahahra, Nnamdi , Managa, Muthumuni , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300244 , vital:57909 , xlink:href="https://doi.org/10.1080/00958972.2022.2087515"
- Description: A novel 5,10,15-tris(5-bromo-2-thienyl),20(phenylcarboxy)porphyrin and its gallium derivative have been synthesized and fully characterized by various spectroscopic techniques and their respective photophysical and photochemical properties, such as the singlet oxygen quantum yield (ΦΔ), fluorescence quantum yield (ΦF) and triplet lifetime (τT) were determined. The complexes were conjugated to PEI_GQDs resulting is stable conjugates, owing to strong π–π stacking interaction between the PEI_GQDs and the porphyrins. PDT studies were carried out on these nanoconjugates and results obtained indicated they are suitable candidates for further in-depth PDT studies.
- Full Text:
- Date Issued: 2022
Photodynamic therapy characteristics of phthalocyanines in the presence of boron doped detonation nanodiamonds
- Matshitse, Refilwe, Nwaji, Njemuwa, Managa, Muthimuni, Chen, Zhi-Long, Nyokong, Tebello
- Authors: Matshitse, Refilwe , Nwaji, Njemuwa , Managa, Muthimuni , Chen, Zhi-Long , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229921 , vital:49723 , xlink:href="https://doi.org/10.1016/j.pdpdt.2021.102705"
- Description: The synthesis, photophysicochemical and photodynamic therapy (PDT) activities of benzothiazole substituted zinc phthalocyanine (Pc): 1 (asymmetrically substituted and composed of no charges), 2 (asymmetrically substituted and composed of three positive charges), and 3 (symmetrically substituted and composed of four positive charges), are presented. The triplet and singlet oxygen quantum yields were highest for complex 2 showing the importance of asymmetry and charge. The complexes are covalently and non-covalently linked to B doped detonation nanodiamonds (B@DNDs) to yield nanohybrids (B@DNDs-1, B@DNDs-2, B@DNDs-3). The presence of B@DNDs, asymmetry and positive charge resulted in improved PDT with the lowest cell viability being observed for B@DNDs-2 at 5%. The cell viability ranged from 5% to 7% for the nanohybrids compared to 19–26% for Pcs alone.
- Full Text:
- Date Issued: 2022
- Authors: Matshitse, Refilwe , Nwaji, Njemuwa , Managa, Muthimuni , Chen, Zhi-Long , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229921 , vital:49723 , xlink:href="https://doi.org/10.1016/j.pdpdt.2021.102705"
- Description: The synthesis, photophysicochemical and photodynamic therapy (PDT) activities of benzothiazole substituted zinc phthalocyanine (Pc): 1 (asymmetrically substituted and composed of no charges), 2 (asymmetrically substituted and composed of three positive charges), and 3 (symmetrically substituted and composed of four positive charges), are presented. The triplet and singlet oxygen quantum yields were highest for complex 2 showing the importance of asymmetry and charge. The complexes are covalently and non-covalently linked to B doped detonation nanodiamonds (B@DNDs) to yield nanohybrids (B@DNDs-1, B@DNDs-2, B@DNDs-3). The presence of B@DNDs, asymmetry and positive charge resulted in improved PDT with the lowest cell viability being observed for B@DNDs-2 at 5%. The cell viability ranged from 5% to 7% for the nanohybrids compared to 19–26% for Pcs alone.
- Full Text:
- Date Issued: 2022
Phthalocyanine based fabricated exfoliated graphite photoanode for electrodegradation of 4-acetamidophenol under visible light irradiation
- Mpeta, Lekhetho S, Nyokong, Tebello
- Authors: Mpeta, Lekhetho S , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295809 , vital:57380 , xlink:href="https://doi.org/10.1016/j.jphotochem.2022.114115"
- Description: In this study exfoliated graphite (EG) was prepared from natural graphite flakes and incorporated with zinc phthalocyanine for fabrication of photoanode. The electron transfer capabilities of fabricated photoanode were examined by using cyclic voltammetry, electrochemical impedance spectroscopy and scanning electrochemical microscopy. Electrophotocatalytic degradation of 4-acetamidophenol in 0.1 M Na2SO4 electrolyte was performed. The photoanode with zinc phthalocyanine (EG-ZnPc) displayed better degradation compared to when only exfoliated graphite was used (EG). Furthermore, electrophotocatalytic degradation gave better performance (removal efficiency of 47.76%) than when individual electrochemical degradation and photodegradation techniques were used.
- Full Text:
- Date Issued: 2022
- Authors: Mpeta, Lekhetho S , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295809 , vital:57380 , xlink:href="https://doi.org/10.1016/j.jphotochem.2022.114115"
- Description: In this study exfoliated graphite (EG) was prepared from natural graphite flakes and incorporated with zinc phthalocyanine for fabrication of photoanode. The electron transfer capabilities of fabricated photoanode were examined by using cyclic voltammetry, electrochemical impedance spectroscopy and scanning electrochemical microscopy. Electrophotocatalytic degradation of 4-acetamidophenol in 0.1 M Na2SO4 electrolyte was performed. The photoanode with zinc phthalocyanine (EG-ZnPc) displayed better degradation compared to when only exfoliated graphite was used (EG). Furthermore, electrophotocatalytic degradation gave better performance (removal efficiency of 47.76%) than when individual electrochemical degradation and photodegradation techniques were used.
- Full Text:
- Date Issued: 2022
Plagiarism and the commodification of knowledge
- Authors: McKenna, Sioux
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426967 , vital:72404 , xlink:href="https://doi.org/10.1007/s10734-022-00926-5"
- Description: Universities have put in place various policies and punishments to manage plagiarism and it is an issue of signifcant interest. This article looks at how plagiarism is discussed in the 55 Higher Education articles between 1982 and June 2022 that make some reference to the term. Many of the articles focused on a police-catch-punish approach and imbued a strong moral charge to the issue. In contrast to such articles were those that presented citation as a complex academic practice that needs to be engaged with educationally. Our understandings of and responses to plagiarism emerge from a number of causal mechanisms but I argue that a key mechanism is the commodifcation of knowledge. Where knowledge is a product to be packaged, bought, and sold, then ownership and attribution become more important than engagement and personal meaning making. Instead of our obsession with a police-catch-punish approach to plagiarism, at a more micro-level, we should be inducting students into the many roles citations serve, and at a macro-level, we should be engaging in considerations of the purposes of a higher education and how we might better enable students to enjoy a transformative relationship to knowledge.
- Full Text:
- Date Issued: 2022
- Authors: McKenna, Sioux
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426967 , vital:72404 , xlink:href="https://doi.org/10.1007/s10734-022-00926-5"
- Description: Universities have put in place various policies and punishments to manage plagiarism and it is an issue of signifcant interest. This article looks at how plagiarism is discussed in the 55 Higher Education articles between 1982 and June 2022 that make some reference to the term. Many of the articles focused on a police-catch-punish approach and imbued a strong moral charge to the issue. In contrast to such articles were those that presented citation as a complex academic practice that needs to be engaged with educationally. Our understandings of and responses to plagiarism emerge from a number of causal mechanisms but I argue that a key mechanism is the commodifcation of knowledge. Where knowledge is a product to be packaged, bought, and sold, then ownership and attribution become more important than engagement and personal meaning making. Instead of our obsession with a police-catch-punish approach to plagiarism, at a more micro-level, we should be inducting students into the many roles citations serve, and at a macro-level, we should be engaging in considerations of the purposes of a higher education and how we might better enable students to enjoy a transformative relationship to knowledge.
- Full Text:
- Date Issued: 2022