Historical diversification of Pseudonympha Wallengren, 1857 (Lepidoptera: Nymphalidae: Satyrinae).
- van Steenderen, Clarke J M, Pringle, Ernest L, Villet, Martin H
- Authors: van Steenderen, Clarke J M , Pringle, Ernest L , Villet, Martin H
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442182 , vital:73965 , https://doi.org/10.1080/00222933.2023.2257373
- Description: The butterfly genus Pseudonympha and several related genera are endemic to southern Africa. Although many of the species are montane, some inhabit the arid interior of South Africa, offering an opportunity to study the palaeobiogeography of this biome. Morphological data (for all species of Pseudonympha and allied African and Asian genera) and molecular data (WG and COI genes for nine of the 15 species of Pseudonympha and all of the southern African endemic genera of Ypthimina) were compiled. Phylogenetic analysis indicated that Pseudonympha apparently originated in the Cape Fold Mountains about 15 Mya ago and spread steadily eastwards and northwards along the Great Escarpment during the aridification of the region, perhaps assisted by orogeny in the east and oceanic cooling in the west. Aridification cycles seem to have intermittently isolated some early lineages in elevated habitats in the interior, so that those lineages show lower speciation rates (or perhaps higher extinction rates) than those in the east. Four species delineation techniques indicated that some species are taxonomically oversplit. Based on genetic polyphyly and morphological similarity, we propose that the status of P. swanepoeli be reduced to that of a subspecies of P. varii, such that all the north-eastern populations from Harrismith to Tzaneen fall under P. varii swanepoeli van Son stat. n., and all the southern populations fall under P. varii varii van Son stat. n. Ultimately, the diversification of both of these lineages seems tied to their host plants’ response to aridification brought on by continental drift and orogeny. Sympatric organisms (eg cicadas) with biologies focused around different resources (eg savanna trees) show other patterns of diversification. The phylogenetic analysis of the subtribe Ypthimina also supports the monophyly of Paternympha, paraphyly of Ypthima, recognition of Thymipa Moore stat. rev. as a phylogenetic independent genus, and new relationships for Strabena.
- Full Text:
- Date Issued: 2023
- Authors: van Steenderen, Clarke J M , Pringle, Ernest L , Villet, Martin H
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442182 , vital:73965 , https://doi.org/10.1080/00222933.2023.2257373
- Description: The butterfly genus Pseudonympha and several related genera are endemic to southern Africa. Although many of the species are montane, some inhabit the arid interior of South Africa, offering an opportunity to study the palaeobiogeography of this biome. Morphological data (for all species of Pseudonympha and allied African and Asian genera) and molecular data (WG and COI genes for nine of the 15 species of Pseudonympha and all of the southern African endemic genera of Ypthimina) were compiled. Phylogenetic analysis indicated that Pseudonympha apparently originated in the Cape Fold Mountains about 15 Mya ago and spread steadily eastwards and northwards along the Great Escarpment during the aridification of the region, perhaps assisted by orogeny in the east and oceanic cooling in the west. Aridification cycles seem to have intermittently isolated some early lineages in elevated habitats in the interior, so that those lineages show lower speciation rates (or perhaps higher extinction rates) than those in the east. Four species delineation techniques indicated that some species are taxonomically oversplit. Based on genetic polyphyly and morphological similarity, we propose that the status of P. swanepoeli be reduced to that of a subspecies of P. varii, such that all the north-eastern populations from Harrismith to Tzaneen fall under P. varii swanepoeli van Son stat. n., and all the southern populations fall under P. varii varii van Son stat. n. Ultimately, the diversification of both of these lineages seems tied to their host plants’ response to aridification brought on by continental drift and orogeny. Sympatric organisms (eg cicadas) with biologies focused around different resources (eg savanna trees) show other patterns of diversification. The phylogenetic analysis of the subtribe Ypthimina also supports the monophyly of Paternympha, paraphyly of Ypthima, recognition of Thymipa Moore stat. rev. as a phylogenetic independent genus, and new relationships for Strabena.
- Full Text:
- Date Issued: 2023
History matters: Societal acceptance of deep-sea mining and incipient conflicts in Papua New Guinea
- van Putten, Ingrid, Aswani, Shankar, Boonstra, W.J, De la Cruz-Modino, R, Das, Jewel, Glaser, Marion, Heck, Nadine, Narayan, Siddharth, Paytan, Adina, Selim, Samiya, Vave, Ron
- Authors: van Putten, Ingrid , Aswani, Shankar , Boonstra, W.J , De la Cruz-Modino, R , Das, Jewel , Glaser, Marion , Heck, Nadine , Narayan, Siddharth , Paytan, Adina , Selim, Samiya , Vave, Ron
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/391453 , vital:68653 , xlink:href="https://doi.org/10.1007/s40152-023-00318-0"
- Description: New marine industries that develop and grow in response to the changing demand for their products have the potential to exert pressure on fragile marine environments. These emerging industries can benefit local communities but equally can have negative environmental and socio-cultural impacts. The development of new and emerging industries, like deep seabed mining (DSM), requires the acceptance and involvement of local communities. Yet, the history of marine exploitation is imbued with conflicts between industries and local communities. This paper presents a DSM case study in Papua New Guinea (PNG) to stimulate debate around the potential for conflict in the pursuit of resource extraction from the deep sea and the social and environmental harm that these extractions can cause. We do so by first presenting a timeline of local and extra-local events and enabling conditions that form the development background for the DSM Solwara 1 project in PNG. We then undertake a media narrative analysis to consider the contribution of aspects of social acceptability to this highly complex and multi-scale conflict. We find that the lack of (or a decrease in) social acceptability contributed to the conflict situation and ultimately the demise of the Solwara 1 project. Extra-locally, the initial development was positively framed around solutions for decarbonisation using new technology. Over time, actions by international NGOs, financial issues related to foreign companies, and asymmetry in the power balance between the Pacific Island nation and global businesses played a role in growing negative perceptions of acceptability. Historical experiences with prior environmental mining disasters, together with sea tenure governance challenges, and a lack of community and stakeholder acceptance also contributed to the demise of the project. Untangling and debating these complex interactions provides context and reasons for the tension between the lack of societal acceptance at a local scale and the perceived need for DSM products in the global North for innovative technologies and decarbonising societies. Better understanding these interactions and tensions can help emerging industries navigate a future blue economy.
- Full Text:
- Date Issued: 2023
- Authors: van Putten, Ingrid , Aswani, Shankar , Boonstra, W.J , De la Cruz-Modino, R , Das, Jewel , Glaser, Marion , Heck, Nadine , Narayan, Siddharth , Paytan, Adina , Selim, Samiya , Vave, Ron
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/391453 , vital:68653 , xlink:href="https://doi.org/10.1007/s40152-023-00318-0"
- Description: New marine industries that develop and grow in response to the changing demand for their products have the potential to exert pressure on fragile marine environments. These emerging industries can benefit local communities but equally can have negative environmental and socio-cultural impacts. The development of new and emerging industries, like deep seabed mining (DSM), requires the acceptance and involvement of local communities. Yet, the history of marine exploitation is imbued with conflicts between industries and local communities. This paper presents a DSM case study in Papua New Guinea (PNG) to stimulate debate around the potential for conflict in the pursuit of resource extraction from the deep sea and the social and environmental harm that these extractions can cause. We do so by first presenting a timeline of local and extra-local events and enabling conditions that form the development background for the DSM Solwara 1 project in PNG. We then undertake a media narrative analysis to consider the contribution of aspects of social acceptability to this highly complex and multi-scale conflict. We find that the lack of (or a decrease in) social acceptability contributed to the conflict situation and ultimately the demise of the Solwara 1 project. Extra-locally, the initial development was positively framed around solutions for decarbonisation using new technology. Over time, actions by international NGOs, financial issues related to foreign companies, and asymmetry in the power balance between the Pacific Island nation and global businesses played a role in growing negative perceptions of acceptability. Historical experiences with prior environmental mining disasters, together with sea tenure governance challenges, and a lack of community and stakeholder acceptance also contributed to the demise of the project. Untangling and debating these complex interactions provides context and reasons for the tension between the lack of societal acceptance at a local scale and the perceived need for DSM products in the global North for innovative technologies and decarbonising societies. Better understanding these interactions and tensions can help emerging industries navigate a future blue economy.
- Full Text:
- Date Issued: 2023
Host-specificity testing of the leaf-feeding flea beetle, Phenrica guerini, a biological control agent for the invasive alien cactus, Pereskia aculeata
- Dixon, Elizabeth, Paterson, Iain D, Muskett, Phillippa C, McConnachie, Andrew
- Authors: Dixon, Elizabeth , Paterson, Iain D , Muskett, Phillippa C , McConnachie, Andrew
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417687 , vital:71478 , xlink:href="https://doi.org/10.1080/09583157.2023.2214342"
- Description: Pereskia aculeata Miller (Cactaceae) is an environmentally damaging invasive alien plant in South Africa and Australia. The flea-beetle, Phenrica guerini Bechyné (Coleoptera: Chrysomelidae), has been used in South Africa as a biological control agent against the plant for more than 30 years but updated host-specificity testing was required to determine its suitability as an agent in Australia. No-choice larval survival tests were conducted on 26 test plant species from 11 families, with survival to the adult stage only being recorded on the target weed, P. aculeata. No-choice oviposition testing with adult P. guerini was conducted on six test plant species. No adult feeding was recorded on any test plants and significantly more eggs were oviposited on P. aculeata (158.8 SE ± 21.4) than on Talinum caffrum (5.2 SE ± 5.2), which was the only test plant on which they oviposited. The adults survived on average 27 days longer on P. aculeata than on any test plant species. In a multiple-choice trial that included all three species that supported any larval feeding as well as P. aculeata, oviposition and feeding was only recorded on target weed. Phenrica guerini is suitably host specific for consideration in Australia as a biological control agent against P. aculeata.
- Full Text:
- Date Issued: 2023
- Authors: Dixon, Elizabeth , Paterson, Iain D , Muskett, Phillippa C , McConnachie, Andrew
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417687 , vital:71478 , xlink:href="https://doi.org/10.1080/09583157.2023.2214342"
- Description: Pereskia aculeata Miller (Cactaceae) is an environmentally damaging invasive alien plant in South Africa and Australia. The flea-beetle, Phenrica guerini Bechyné (Coleoptera: Chrysomelidae), has been used in South Africa as a biological control agent against the plant for more than 30 years but updated host-specificity testing was required to determine its suitability as an agent in Australia. No-choice larval survival tests were conducted on 26 test plant species from 11 families, with survival to the adult stage only being recorded on the target weed, P. aculeata. No-choice oviposition testing with adult P. guerini was conducted on six test plant species. No adult feeding was recorded on any test plants and significantly more eggs were oviposited on P. aculeata (158.8 SE ± 21.4) than on Talinum caffrum (5.2 SE ± 5.2), which was the only test plant on which they oviposited. The adults survived on average 27 days longer on P. aculeata than on any test plant species. In a multiple-choice trial that included all three species that supported any larval feeding as well as P. aculeata, oviposition and feeding was only recorded on target weed. Phenrica guerini is suitably host specific for consideration in Australia as a biological control agent against P. aculeata.
- Full Text:
- Date Issued: 2023
Impact assessment of genetically modified TELA® Bt. maize variety adoption on yield, household income, technical efficiency and food security: a case of maize farmers in Limpopo and Mpumalanga Provinces, South Africa.
- Authors: Mailula, Lesiba Pertunia
- Date: 2023
- Subjects: Food security , Farmers -- Training of , Seed technology -- Economic aspects
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/28266 , vital:74040
- Description: The agricultural sector is widely recognized as a crucial factor for promoting sustainable economic development, reducing poverty, and ensuring food security in developing countries. However, in Africa, the agricultural sector continues to underperform, with growth rates falling behind the population growth, this can be attributed to various challenges, including climate change and pest infestation. This has over the years weakened the defence of crops leading to the disruptions in crop production and food security. As such, calls have been made that adoption of the agricultural technology may promote food security through high yields. This is because agricultural technology crops have improved varieties such as drought tolerance and pest resistance traits. However, adoption of improved agricultural technology in Africa has been very sluggish amongst smallholder farmers, particularly for GM seed, this is due to the on-going controversies and compliance requirements regarding GM technologies. The controversies are raised by the unknown benefits and risks associated with the adoption of GM seeds technology. Furthermore, there are mixed benefits associated with GM technology adoption as well as methodological and data gaps associated with assessment of GM impact on the farmer’s welfare. In 2016, five Bt. maize varieties trademarked TELA were developed through the WEMA project. Trials were approved and launched with smallholder farmers in various countries in Africa, and South Africa is not an exception. Several smallholder maize farmers have accessed the TELA Bt. maize varieties through local seed companies and have been producing it for the past seasons. Yet, no study that has been conducted on the impact of the GM TELA Bt. maize technology adoption on yield, income, food security and technical efficiency, hence, a need for such a study. The primary data was collected from 289 183 TELA Bt. and 106 non-TELA Bt. smallholder farmers in Mpumalanga and Limpopo provinces using convenience and snowball sampling techniques. Data were analysed using various analytical tools that included descriptive statistics, gross margin analysis, Household Dietary Diversity Score, Stochastic Frontier Model and the Propensity Score Matching, modelled through the Probit regression model. These tools were utilised to address the objectives. The descriptive statistics show that the TELA Bt. maize variety yielded 61.1 percent more maize output as compared to non-TELA Bt. maize farmers, with an average of 691kg ha and 429kg ha, respectively. The gross margin analysis showed higher subsequent income for the TELA Bt. maize farmers R2 834.93 compared to R2 124.96 for the non-TELA Bt. maize farmers. The results of the HDDS showed a marginal effect of TELA Bt. maize seed technology on food diversity. The average HDDS scores were 8.4 and 7.5 for the TELA Bt. and non-TELA Bt. maize farmers, respectively. The Stochastic Frontier Analysis SFA results revealed that both the TELA Bt. maize farmers and non-TELA Bt. maize farmers were technically inefficient. However, the TELA Bt. maize farmers were better-off than their counterparts, with mean technical efficiency scores of 0.416 and 0.328, respectively. The Propensity Score Matching PSM using the Probit model revealed that gender 0.6064, number of years in farming 0.0099 credit 1.1438 and market access 0.4427 had a positive and significant influence on the decision taken by the farmers to adopt TELA Bt. maize seed technology. However, access to extension services was found to have a negative and significant impact on the adoption of TELA Bt. maize seed technology. The Average Treatment Effect of the Treated ATT using the Nearest Neighbour Matching algorithm indicated that adoption of TELA Bt. maize technology improved farmers’ yields by 254.3kg, income by 0.36 cents and technical efficiency by 8.6 percent. There was no significant relationship observed between adoption of the GM technology and food security. Generally, the results from this study imply that adoption of GM TELA Bt. maize seed technology improves farmers’ yields, income, technical efficiency, as well as food security. The study therefore, recommends increased awareness of the GM seed technology benefits to farmers, coupled with training and capacity development to enhance adoption of seed technology towards improved farmers’ welfare. In addition, there is a need for sustained Research and Development investments towards GM seed technologies to enhance maize productivity and technical efficiency of the farmers. , Thesis (MSc) -- Faculty of Science and Agriculture, 2023
- Full Text:
- Date Issued: 2023
- Authors: Mailula, Lesiba Pertunia
- Date: 2023
- Subjects: Food security , Farmers -- Training of , Seed technology -- Economic aspects
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/28266 , vital:74040
- Description: The agricultural sector is widely recognized as a crucial factor for promoting sustainable economic development, reducing poverty, and ensuring food security in developing countries. However, in Africa, the agricultural sector continues to underperform, with growth rates falling behind the population growth, this can be attributed to various challenges, including climate change and pest infestation. This has over the years weakened the defence of crops leading to the disruptions in crop production and food security. As such, calls have been made that adoption of the agricultural technology may promote food security through high yields. This is because agricultural technology crops have improved varieties such as drought tolerance and pest resistance traits. However, adoption of improved agricultural technology in Africa has been very sluggish amongst smallholder farmers, particularly for GM seed, this is due to the on-going controversies and compliance requirements regarding GM technologies. The controversies are raised by the unknown benefits and risks associated with the adoption of GM seeds technology. Furthermore, there are mixed benefits associated with GM technology adoption as well as methodological and data gaps associated with assessment of GM impact on the farmer’s welfare. In 2016, five Bt. maize varieties trademarked TELA were developed through the WEMA project. Trials were approved and launched with smallholder farmers in various countries in Africa, and South Africa is not an exception. Several smallholder maize farmers have accessed the TELA Bt. maize varieties through local seed companies and have been producing it for the past seasons. Yet, no study that has been conducted on the impact of the GM TELA Bt. maize technology adoption on yield, income, food security and technical efficiency, hence, a need for such a study. The primary data was collected from 289 183 TELA Bt. and 106 non-TELA Bt. smallholder farmers in Mpumalanga and Limpopo provinces using convenience and snowball sampling techniques. Data were analysed using various analytical tools that included descriptive statistics, gross margin analysis, Household Dietary Diversity Score, Stochastic Frontier Model and the Propensity Score Matching, modelled through the Probit regression model. These tools were utilised to address the objectives. The descriptive statistics show that the TELA Bt. maize variety yielded 61.1 percent more maize output as compared to non-TELA Bt. maize farmers, with an average of 691kg ha and 429kg ha, respectively. The gross margin analysis showed higher subsequent income for the TELA Bt. maize farmers R2 834.93 compared to R2 124.96 for the non-TELA Bt. maize farmers. The results of the HDDS showed a marginal effect of TELA Bt. maize seed technology on food diversity. The average HDDS scores were 8.4 and 7.5 for the TELA Bt. and non-TELA Bt. maize farmers, respectively. The Stochastic Frontier Analysis SFA results revealed that both the TELA Bt. maize farmers and non-TELA Bt. maize farmers were technically inefficient. However, the TELA Bt. maize farmers were better-off than their counterparts, with mean technical efficiency scores of 0.416 and 0.328, respectively. The Propensity Score Matching PSM using the Probit model revealed that gender 0.6064, number of years in farming 0.0099 credit 1.1438 and market access 0.4427 had a positive and significant influence on the decision taken by the farmers to adopt TELA Bt. maize seed technology. However, access to extension services was found to have a negative and significant impact on the adoption of TELA Bt. maize seed technology. The Average Treatment Effect of the Treated ATT using the Nearest Neighbour Matching algorithm indicated that adoption of TELA Bt. maize technology improved farmers’ yields by 254.3kg, income by 0.36 cents and technical efficiency by 8.6 percent. There was no significant relationship observed between adoption of the GM technology and food security. Generally, the results from this study imply that adoption of GM TELA Bt. maize seed technology improves farmers’ yields, income, technical efficiency, as well as food security. The study therefore, recommends increased awareness of the GM seed technology benefits to farmers, coupled with training and capacity development to enhance adoption of seed technology towards improved farmers’ welfare. In addition, there is a need for sustained Research and Development investments towards GM seed technologies to enhance maize productivity and technical efficiency of the farmers. , Thesis (MSc) -- Faculty of Science and Agriculture, 2023
- Full Text:
- Date Issued: 2023
Impact of Access and Benefit Sharing implementation on biological control genetic resources
- Mason, Peter G, Barratt, Barbara I P, Mc Kay, Fernando, Klapwijk, Johannette N, Silvestri, Luciano C, Hill, Martin P, Hinz, Hariet L, Sheppard, Andy, Brodeur, Jacques, Vitorino, Marcello Diniz, Weyl, Philip S R, Hoelmer, Kim A
- Authors: Mason, Peter G , Barratt, Barbara I P , Mc Kay, Fernando , Klapwijk, Johannette N , Silvestri, Luciano C , Hill, Martin P , Hinz, Hariet L , Sheppard, Andy , Brodeur, Jacques , Vitorino, Marcello Diniz , Weyl, Philip S R , Hoelmer, Kim A
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/418013 , vital:71501 , xlink:href="https://doi.org/10.1007/s10526-023-10176-8"
- Description: The third objective of the Convention on Biological Diversity, the fair and equitable sharing of benefits arising out of the use of genetic resources was further developed when the Nagoya Protocol on Access and Benefit Sharing came into effect in 2014. Interpretation of how this agreement is being implemented is wide-ranging and there are implications for biological control. A survey of biological control workers indicated that while some countries have facilitated access to biological control genetic resources, requirements in other countries have impeded biological control implementation. There was consensus that benefits to provider countries should be in the form of supporting local research communities. There was also agreement that the free use and exchange of biological control genetic resources has provided benefits to the global community, including to both providers and recipients of the agents. It is recommended that consideration of the free use and exchange principal should be a key element of Access and Benefit Sharing measures for the future.
- Full Text:
- Date Issued: 2023
- Authors: Mason, Peter G , Barratt, Barbara I P , Mc Kay, Fernando , Klapwijk, Johannette N , Silvestri, Luciano C , Hill, Martin P , Hinz, Hariet L , Sheppard, Andy , Brodeur, Jacques , Vitorino, Marcello Diniz , Weyl, Philip S R , Hoelmer, Kim A
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/418013 , vital:71501 , xlink:href="https://doi.org/10.1007/s10526-023-10176-8"
- Description: The third objective of the Convention on Biological Diversity, the fair and equitable sharing of benefits arising out of the use of genetic resources was further developed when the Nagoya Protocol on Access and Benefit Sharing came into effect in 2014. Interpretation of how this agreement is being implemented is wide-ranging and there are implications for biological control. A survey of biological control workers indicated that while some countries have facilitated access to biological control genetic resources, requirements in other countries have impeded biological control implementation. There was consensus that benefits to provider countries should be in the form of supporting local research communities. There was also agreement that the free use and exchange of biological control genetic resources has provided benefits to the global community, including to both providers and recipients of the agents. It is recommended that consideration of the free use and exchange principal should be a key element of Access and Benefit Sharing measures for the future.
- Full Text:
- Date Issued: 2023
Impact of relaxing flood policy interventions on fish production: lessons from earthen pond‑based farmers in Southwest Nigeria
- Authors: Adewale, Isaac Olutumise
- Date: 2023
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/11260/9169 , vital:73018
- Description: These days, aquatic (fish) welfare is a major issue and a significant component that affects fish output. Although numerous factors can be involved, climate-induced floods are one of the most critical limiting factors in the aquaculture and fisheries industry’s development. Understanding the extent of losses and damages caused by floods at the farm level will thereby exacerbate pre-emptive policy responses. Thus, the impact of floods on fish production by focusing on catfish earthen pond-based farmers in Southwest Nigeria is presented. A survey is conducted for 150 fish farms in the region. A marginal treatment effects (MTE) approach is employed to determine the heterogeneity across the households and the policy-relevant treatment effects (PRTE). The results show significant heterogeneity in the effects of floods on fish production, considering both observed and unobserved characteristics of the farmers. It is shown that flood significantly increases output loss. Furthermore, farmers with high propensity scores to flood tend to have a high likelihood of incurring output loss. The estimates of PRTE reveal that relaxing policy strategies, such as access to climate information and climate-related training and workshops, would significantly exacerbate output loss due to flood incidences. Thus, intensifying awareness and sensitization on climate change policies will address the flood menace and still increase food production.
- Full Text:
- Date Issued: 2023
- Authors: Adewale, Isaac Olutumise
- Date: 2023
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/11260/9169 , vital:73018
- Description: These days, aquatic (fish) welfare is a major issue and a significant component that affects fish output. Although numerous factors can be involved, climate-induced floods are one of the most critical limiting factors in the aquaculture and fisheries industry’s development. Understanding the extent of losses and damages caused by floods at the farm level will thereby exacerbate pre-emptive policy responses. Thus, the impact of floods on fish production by focusing on catfish earthen pond-based farmers in Southwest Nigeria is presented. A survey is conducted for 150 fish farms in the region. A marginal treatment effects (MTE) approach is employed to determine the heterogeneity across the households and the policy-relevant treatment effects (PRTE). The results show significant heterogeneity in the effects of floods on fish production, considering both observed and unobserved characteristics of the farmers. It is shown that flood significantly increases output loss. Furthermore, farmers with high propensity scores to flood tend to have a high likelihood of incurring output loss. The estimates of PRTE reveal that relaxing policy strategies, such as access to climate information and climate-related training and workshops, would significantly exacerbate output loss due to flood incidences. Thus, intensifying awareness and sensitization on climate change policies will address the flood menace and still increase food production.
- Full Text:
- Date Issued: 2023
Impact of sustainable tax revenue and expenditure on the achievement of sustainable development goals in some selected African countries
- Authors: Kola, Benson Ajeigbe
- Date: 2023
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/11260/9234 , vital:73024
- Description: Abstract The study examined the impact of Sustainable Tax Revenue and Expenditure on the achievement of Sustainable Development Goals in African countries using secondary data. The dataset was extracted from the World Development Indicators database. The large gap between developed and developing countries when comparing the probability of them achieving the SDGs was the main motivation behind this study. Data retrieved from 45 countries comprised of both African and developed countries for the period 2010–2020 was analyzed using the Generalized Method of Moments technique. The results revealed that the coefficients of grants received, various forms of taxes, and other revenue have a positive effect on economic growth but a negative effect on poverty and unemployment for African and developed countries. This finding suggests that improvements in tax revenue generation, grants and other revenue accumulation across different sources boost economic performance and the welfare of individuals in the analyzed countries. The outcome is an indication that accumulating more grants from different sources will help to achieve sustainable development, improve financial stability, contributes to the economic growth and development in these countries. This study can guide policymakers, governments, international institutions, revenue bodies such as SARS and other stakeholders in their various planning and other decision-making endeavors. Governments and other policymakers must ensure the efficient generation and sustainable utilization of revenue generated from taxes and other revenues to spur the growth and development of their countries. They should have Growth-Sustainability-Oriented Fiscal Adjustment Programs and Sustainable Government Expenditure that can help push and redirect governments to achieve the SDGs in Africa.
- Full Text:
- Date Issued: 2023
- Authors: Kola, Benson Ajeigbe
- Date: 2023
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/11260/9234 , vital:73024
- Description: Abstract The study examined the impact of Sustainable Tax Revenue and Expenditure on the achievement of Sustainable Development Goals in African countries using secondary data. The dataset was extracted from the World Development Indicators database. The large gap between developed and developing countries when comparing the probability of them achieving the SDGs was the main motivation behind this study. Data retrieved from 45 countries comprised of both African and developed countries for the period 2010–2020 was analyzed using the Generalized Method of Moments technique. The results revealed that the coefficients of grants received, various forms of taxes, and other revenue have a positive effect on economic growth but a negative effect on poverty and unemployment for African and developed countries. This finding suggests that improvements in tax revenue generation, grants and other revenue accumulation across different sources boost economic performance and the welfare of individuals in the analyzed countries. The outcome is an indication that accumulating more grants from different sources will help to achieve sustainable development, improve financial stability, contributes to the economic growth and development in these countries. This study can guide policymakers, governments, international institutions, revenue bodies such as SARS and other stakeholders in their various planning and other decision-making endeavors. Governments and other policymakers must ensure the efficient generation and sustainable utilization of revenue generated from taxes and other revenues to spur the growth and development of their countries. They should have Growth-Sustainability-Oriented Fiscal Adjustment Programs and Sustainable Government Expenditure that can help push and redirect governments to achieve the SDGs in Africa.
- Full Text:
- Date Issued: 2023
In silico substrate-binding profiling for SARS-CoV-2 Main protease (Mpro) using Hexapeptide substrates
- Zabo, Sophakama, Lobb, Kevin A
- Authors: Zabo, Sophakama , Lobb, Kevin A
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/452711 , vital:75164 , xlink:href="https://doi.org/10.3390/v15071480"
- Description: The SARS-CoV-2 main protease (Mpro) is essential for the life cycle of the COVID-19 virus. It cleaves the two polyproteins at 11 positions to generate mature proteins for virion formation. The cleavage site on these polyproteins is known to be Leu-Gln↓(Ser/Ala/Gly). A range of hexapeptides that follow the known sequence for recognition and cleavage was constructed using RDKit libraries and complexed with the crystal structure of Mpro (PDB ID 6XHM) through extensive molecular docking calculations. A subset of 131 of these complexes underwent 20 ns molecular dynamics simulations. The analyses of the trajectories from molecular dynamics included principal component analysis (PCA), and a method to compare PCA plots from separate trajectories was developed in terms of encoding PCA progression during the simulations. The hexapeptides formed stable complexes as expected, with reproducible molecular docking of the substrates given the extensiveness of the procedure. Only Lys-Leu-Gln*** (KLQ***) sequence complexes were studied for molecular dynamics. In this subset of complexes, the PCA analysis identified four classifications of protein motions across these sequences. KLQ*** complexes illustrated the effect of changes in substrate on the active site, with implications for understanding the substrate recognition of Mpro and informing the development of small molecule inhibitors.
- Full Text:
- Date Issued: 2023
- Authors: Zabo, Sophakama , Lobb, Kevin A
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/452711 , vital:75164 , xlink:href="https://doi.org/10.3390/v15071480"
- Description: The SARS-CoV-2 main protease (Mpro) is essential for the life cycle of the COVID-19 virus. It cleaves the two polyproteins at 11 positions to generate mature proteins for virion formation. The cleavage site on these polyproteins is known to be Leu-Gln↓(Ser/Ala/Gly). A range of hexapeptides that follow the known sequence for recognition and cleavage was constructed using RDKit libraries and complexed with the crystal structure of Mpro (PDB ID 6XHM) through extensive molecular docking calculations. A subset of 131 of these complexes underwent 20 ns molecular dynamics simulations. The analyses of the trajectories from molecular dynamics included principal component analysis (PCA), and a method to compare PCA plots from separate trajectories was developed in terms of encoding PCA progression during the simulations. The hexapeptides formed stable complexes as expected, with reproducible molecular docking of the substrates given the extensiveness of the procedure. Only Lys-Leu-Gln*** (KLQ***) sequence complexes were studied for molecular dynamics. In this subset of complexes, the PCA analysis identified four classifications of protein motions across these sequences. KLQ*** complexes illustrated the effect of changes in substrate on the active site, with implications for understanding the substrate recognition of Mpro and informing the development of small molecule inhibitors.
- Full Text:
- Date Issued: 2023
Inclusion complexation and liposomal encapsulation of an isoniazid hydrazone derivative in cyclodextrin for pH-dependent controlled release
- Safari, Justin B, Mona, Lamine B, Sekaleli, Bafokeng T, Avudi, Bénite K, Isamura, Bienfait K, Mukubwa, Grady K, Salami, Sodeeq A, Mbinze, Jérémie K, Lobb, Kevin A, Krause, Rui W M, Nkanga, Christian I
- Authors: Safari, Justin B , Mona, Lamine B , Sekaleli, Bafokeng T , Avudi, Bénite K , Isamura, Bienfait K , Mukubwa, Grady K , Salami, Sodeeq A , Mbinze, Jérémie K , Lobb, Kevin A , Krause, Rui W M , Nkanga, Christian I
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/452727 , vital:75166 , xlink:href="https://doi.org/10.1016/j.jddst.2023.104302"
- Description: Tuberculosis, a predominantly pulmonary pathology, is currently the deadliest infection worldwide. Its treatment is based on combination therapy involving selected antimicrobials including Isoniazid. However, physicochemical properties of isoniazid negatively affect the clinical performance of current tuberculosis regimens, causing drug resistance development and increasing mortality rates. Liposomal encapsulation improves antituberculosis drug delivery; however, nano-formulation of isoniazid remains challenging due to its small molecular size and high hydrophilicity. Therefore, this study aimed to derivatize isoniazid and formulate a controlled delivery system using the concept of drug-in-cyclodextrins-in-liposomes to enhance drug biopharmaceutical properties. A prodrug of isoniazid was synthesized and screened for its ability to form stable complexes with α, β, and γ cyclodextrins. A selected inclusion complex with β-cyclodextrin was encapsulated in liposomes and assessed for controlled release of isoniazid. Successful formation of a 1:1 complex was established and characterized, followed by molecular modeling studies to demonstrate strength of the interactions within the complex and predicted complex structure. The inclusion complex was successfully encapsulated in liposomes using the thin film hydration method and the ethanol injection ultrasonic dispersion, with the latter giving the best results. These findings demonstrate the potential.
- Full Text:
- Date Issued: 2023
- Authors: Safari, Justin B , Mona, Lamine B , Sekaleli, Bafokeng T , Avudi, Bénite K , Isamura, Bienfait K , Mukubwa, Grady K , Salami, Sodeeq A , Mbinze, Jérémie K , Lobb, Kevin A , Krause, Rui W M , Nkanga, Christian I
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/452727 , vital:75166 , xlink:href="https://doi.org/10.1016/j.jddst.2023.104302"
- Description: Tuberculosis, a predominantly pulmonary pathology, is currently the deadliest infection worldwide. Its treatment is based on combination therapy involving selected antimicrobials including Isoniazid. However, physicochemical properties of isoniazid negatively affect the clinical performance of current tuberculosis regimens, causing drug resistance development and increasing mortality rates. Liposomal encapsulation improves antituberculosis drug delivery; however, nano-formulation of isoniazid remains challenging due to its small molecular size and high hydrophilicity. Therefore, this study aimed to derivatize isoniazid and formulate a controlled delivery system using the concept of drug-in-cyclodextrins-in-liposomes to enhance drug biopharmaceutical properties. A prodrug of isoniazid was synthesized and screened for its ability to form stable complexes with α, β, and γ cyclodextrins. A selected inclusion complex with β-cyclodextrin was encapsulated in liposomes and assessed for controlled release of isoniazid. Successful formation of a 1:1 complex was established and characterized, followed by molecular modeling studies to demonstrate strength of the interactions within the complex and predicted complex structure. The inclusion complex was successfully encapsulated in liposomes using the thin film hydration method and the ethanol injection ultrasonic dispersion, with the latter giving the best results. These findings demonstrate the potential.
- Full Text:
- Date Issued: 2023
Information extraction model from Ge’ez texts
- Gebeyehu, Seffi, Wolde, Worke, Shibeshi, Zelalem S
- Authors: Gebeyehu, Seffi , Wolde, Worke , Shibeshi, Zelalem S
- Date: 2023
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429176 , vital:72565 , 10.11591/ijeecs.v30.i2.pp787-795
- Description: Nowadays, voluminous and unstructured textual data is found on the Internet that could provide varied valuable information for different institutions such as health care, business-related, training, religion, culture, and history, among others. A such alarming growth of unstructured data fosters the need for various methods and techniques to extract valuable information from unstructured data. However, exploring helpful information to satisfy the needs of the stakeholders becomes a problem due to information overload via the internet. This paper, therefore, presents an effective model for extracting named entities from Ge'ez text using deep learning algorithms. A data set with a total of 5,270 sentences were used for training and testing purposes. Two experimental setups, i.e., long short-term memory (LSTM) and bidirectional long short-term memory (Bi-LSTM) were used to make an empirical evaluation with training and a testing split ratio of 80% to 20%, respectively. Experimental results showed that the proposed model could be a practical solution for building information extraction (IE) systems using Bi-LSTM, reaching a training, validation, and testing accuracy as high as 98.59%, 97.96%, and 96.21%, respectively. The performance evaluation results reflect a promising performance of the model compared with resource-rich languages such as English.
- Full Text:
- Date Issued: 2023
- Authors: Gebeyehu, Seffi , Wolde, Worke , Shibeshi, Zelalem S
- Date: 2023
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429176 , vital:72565 , 10.11591/ijeecs.v30.i2.pp787-795
- Description: Nowadays, voluminous and unstructured textual data is found on the Internet that could provide varied valuable information for different institutions such as health care, business-related, training, religion, culture, and history, among others. A such alarming growth of unstructured data fosters the need for various methods and techniques to extract valuable information from unstructured data. However, exploring helpful information to satisfy the needs of the stakeholders becomes a problem due to information overload via the internet. This paper, therefore, presents an effective model for extracting named entities from Ge'ez text using deep learning algorithms. A data set with a total of 5,270 sentences were used for training and testing purposes. Two experimental setups, i.e., long short-term memory (LSTM) and bidirectional long short-term memory (Bi-LSTM) were used to make an empirical evaluation with training and a testing split ratio of 80% to 20%, respectively. Experimental results showed that the proposed model could be a practical solution for building information extraction (IE) systems using Bi-LSTM, reaching a training, validation, and testing accuracy as high as 98.59%, 97.96%, and 96.21%, respectively. The performance evaluation results reflect a promising performance of the model compared with resource-rich languages such as English.
- Full Text:
- Date Issued: 2023
Inhibiting human dipeptidyl peptidase IV using cannabinoids and Leonotis leonurus extracts as a potential therapy for the management of diabetes
- Mkabayi, Lithalethu, Viljoen, Zenobia, Lobb, Kevin A, Pletschke, Brett I, Frost, Carminita L
- Authors: Mkabayi, Lithalethu , Viljoen, Zenobia , Lobb, Kevin A , Pletschke, Brett I , Frost, Carminita L
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/452745 , vital:75167 , xlink:href="https://www.thieme-connect.com/products/ejournals/html/10.1055/s-0043-1773924"
- Description: Diabetes is a chronic metabolic disorder that has been shown to affect a growing number of people worldwide. Controlling blood glucose levels is one of the possible strategies to treat type 2 diabetes mellitus (T2DM). It has been established that the inhibition of dipeptidyl peptidase IV (DPP-IV) prolongs the activity of incretin hormones, which serve as key stimulators of insulin secretion and regulation of blood glucose levels. Although several synthetic DPP-IV inhibitors are available, there is still a need for naturally sourced inhibitors that have fewer to no undesirable side effects. In this study, cannabinoids and Leonotis leonurus aqueous extracts were evaluated for their inhibitory effects against recombinant human DPP-IV. Their potential inhibition mechanism was explored using in vitro and in silico approaches. All tested cannabinoids and L. leonurus aqueous extracts showed significant inhibitory activity against DPP-IV. Phytochemical analysis of L. leonurus extract indicated the presence of diterpenoids and alkaloids, which might contribute to the inhibitory activity. In molecular docking studies, among different constituents known in L. leonurus, luteolin and marrubiin showed binding energy of -7.2 kcal/mol and cannabinoids (cannabidiol, cannabigerol, cannabinol and Δ9-tetrahydrocannabinol) showed binding energies ranging from -6.5 to -8.2 kcal/mol. Molecular dynamics revealed that all tested compounds formed stable complexes with the enzyme during 100 ns simulation, indicating that they are good ligands. This study provided preliminary evidence for the potential application of the selected cannabinoids and L. leonurus in maintaining glucose homeostasis, suggesting that they could be suitable therapeutic candidates for managing T2DM.
- Full Text:
- Date Issued: 2023
- Authors: Mkabayi, Lithalethu , Viljoen, Zenobia , Lobb, Kevin A , Pletschke, Brett I , Frost, Carminita L
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/452745 , vital:75167 , xlink:href="https://www.thieme-connect.com/products/ejournals/html/10.1055/s-0043-1773924"
- Description: Diabetes is a chronic metabolic disorder that has been shown to affect a growing number of people worldwide. Controlling blood glucose levels is one of the possible strategies to treat type 2 diabetes mellitus (T2DM). It has been established that the inhibition of dipeptidyl peptidase IV (DPP-IV) prolongs the activity of incretin hormones, which serve as key stimulators of insulin secretion and regulation of blood glucose levels. Although several synthetic DPP-IV inhibitors are available, there is still a need for naturally sourced inhibitors that have fewer to no undesirable side effects. In this study, cannabinoids and Leonotis leonurus aqueous extracts were evaluated for their inhibitory effects against recombinant human DPP-IV. Their potential inhibition mechanism was explored using in vitro and in silico approaches. All tested cannabinoids and L. leonurus aqueous extracts showed significant inhibitory activity against DPP-IV. Phytochemical analysis of L. leonurus extract indicated the presence of diterpenoids and alkaloids, which might contribute to the inhibitory activity. In molecular docking studies, among different constituents known in L. leonurus, luteolin and marrubiin showed binding energy of -7.2 kcal/mol and cannabinoids (cannabidiol, cannabigerol, cannabinol and Δ9-tetrahydrocannabinol) showed binding energies ranging from -6.5 to -8.2 kcal/mol. Molecular dynamics revealed that all tested compounds formed stable complexes with the enzyme during 100 ns simulation, indicating that they are good ligands. This study provided preliminary evidence for the potential application of the selected cannabinoids and L. leonurus in maintaining glucose homeostasis, suggesting that they could be suitable therapeutic candidates for managing T2DM.
- Full Text:
- Date Issued: 2023
International agreement for the use and exchange of classical biological control genetic resources: a practical proposal
- Mason, Peter G, Mc Kay, Fernando, Silvestri, Luciano C, Hill, Martin P, Weyl, Philip S R, Hinz, Hariet L, Brodeur, Jacques, Vitorino, Marcello Diniz, Barratt, Barbara I P
- Authors: Mason, Peter G , Mc Kay, Fernando , Silvestri, Luciano C , Hill, Martin P , Weyl, Philip S R , Hinz, Hariet L , Brodeur, Jacques , Vitorino, Marcello Diniz , Barratt, Barbara I P
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/418025 , vital:71502 , xlink:href="https://doi.org/10.1007/s10526-023-10177-7"
- Description: The Nagoya Protocol on Access and Benefit Sharing (ABS) was implemented to further develop the third objective of the Convention on Biological Diversity, the fair and equitable sharing of benefits arising out of the utilization of genetic resources. Interpretation of this agreement is wide-ranging and there is concern that if ABS measures are poorly implemented biological control and the resultant public good will be greatly impeded. The ethos of multilateral use and exchange of genetic resources used in classical biological control will be particularly affected. In the spirit of the fair and equitable sharing of benefits arising out of the utilization of genetic resources, we propose a simple practical solution in the form of an international agreement on the use and exchange of classical biological control genetic resources.
- Full Text:
- Date Issued: 2023
- Authors: Mason, Peter G , Mc Kay, Fernando , Silvestri, Luciano C , Hill, Martin P , Weyl, Philip S R , Hinz, Hariet L , Brodeur, Jacques , Vitorino, Marcello Diniz , Barratt, Barbara I P
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/418025 , vital:71502 , xlink:href="https://doi.org/10.1007/s10526-023-10177-7"
- Description: The Nagoya Protocol on Access and Benefit Sharing (ABS) was implemented to further develop the third objective of the Convention on Biological Diversity, the fair and equitable sharing of benefits arising out of the utilization of genetic resources. Interpretation of this agreement is wide-ranging and there is concern that if ABS measures are poorly implemented biological control and the resultant public good will be greatly impeded. The ethos of multilateral use and exchange of genetic resources used in classical biological control will be particularly affected. In the spirit of the fair and equitable sharing of benefits arising out of the utilization of genetic resources, we propose a simple practical solution in the form of an international agreement on the use and exchange of classical biological control genetic resources.
- Full Text:
- Date Issued: 2023
Introducing VET Africa 4.0
- Lotz-Sisitka, Heila, McGrath, Simon
- Authors: Lotz-Sisitka, Heila , McGrath, Simon
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/434930 , vital:73117 , ISBN 978-1529224634 , https://bristoluniversitypress.co.uk/transitioning-vocational-education-and-training-in-africa
- Description: This book is about vocational education and training (VET). It is concerned with how the current policy and practice orthodoxy is not working despite the efforts of educators and learners. It is driven by a realization that the futures for which VET is intended to prepare people are ever more precarious at the individual, societal and planetary levels. And it is motivated by a sense that while better futures are possible, VET is poorly positioned to respond to the new skilling needs these will require.
- Full Text:
- Date Issued: 2023
- Authors: Lotz-Sisitka, Heila , McGrath, Simon
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/434930 , vital:73117 , ISBN 978-1529224634 , https://bristoluniversitypress.co.uk/transitioning-vocational-education-and-training-in-africa
- Description: This book is about vocational education and training (VET). It is concerned with how the current policy and practice orthodoxy is not working despite the efforts of educators and learners. It is driven by a realization that the futures for which VET is intended to prepare people are ever more precarious at the individual, societal and planetary levels. And it is motivated by a sense that while better futures are possible, VET is poorly positioned to respond to the new skilling needs these will require.
- Full Text:
- Date Issued: 2023
Investigation into response of wheat genotypes to drought and optimum conditions in the Eastern Cape Province, South Africa
- Authors: Mzileni L S
- Date: 2023
- Subjects: Bonanza farms , Wheat , Drought - tolerant plants
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/27732 , vital:69397
- Description: Wheat is generally one of the dominant crops globally, being mainly used for human food and livestock feed. Due to climate change, drought makes it challenging to produce enough wheat mostly under dryland production regions in South Africa. Drought stress has severely reduced wheat yield by up to 70 percent, and adversely compromised wheat grain quality. The adoption of drought-tolerant cultivars offers a sustainable and low-cost solution for increasing wheat yields and minimise importing the crop to meet national requirements. The main objective of this study was to investigate the response of different wheat genotypes to drought and optimum conditions in the Eastern Cape Province, South Africa. Forty diverse wheat genotypes were evaluated in this study. The specific objectives were: (i) to evaluate the response of wheat genotypes under optimum and drought-stressed field conditions; (ii) to determine the effect of terminal drought stress on wheat grain quality composition; and (iii) to identify appropriate drought tolerance indices that can be used as selection tools under field conditions. This study was conducted in the field using a 5x8 alpha lattice design, replicated twice under two water regimes (drought and optimum) over two consecutive winter seasons of 2020 and 2021 at two different sites namely University of Fort Hare Research Farm in Alice, and Zanyokwe irrigation scheme in Keiskamahoek. Drought stress was imposed from 50% flowering up to physiological maturity. Data on agro-physiological traits such as duration to heading (DTH); flowering (DTF); maturity (DTM); plant height (HT); spike length (SL); number of spikelets per spike (SPS); kernels per spike (KPS); and grain yield (GY (kg/ha)) was subjected to the analysis of variance using Genstat 18th edition. As the study took place over two sites, a combined ANOVA table revealed significant differences (p0.001) among genotypes, and all interactions such as genotype by water regime (GWR); genotype by seasons (GS) for all studied traits. Notably, the extent and severity of drought differed between geographical regions and between seasons. This necessitated the adoption of the additive main effect and multiplicative interaction analysis (AMMI) for the identification of stable genotypes under two different water regimes over two sites. Regarding grain yield, superior and/or stable genotypes included G5 (4334 kg/ha under optimum, and 2871kg/ha under drought), and G22 (4418 kg/ha under optimum, and 2624kg/ha under drought) at the UFH site. G21 (3194 kg/ha under optimum, and 2938 kg/ha under drought), G33 (2552kg/ha under optimum, and 3810 kg/ha under drought), and G35 (2688 kg/ha under optimum, and 3309 kg/ha under drought) at the ZAN site. Stable genotypes across sites included G21 and G33. There were generally weak correlations between agro-physiological traits and grain yield. From the experiment, grain quality traits such as fixed protein (PF); wet gluten (WG); hectolitre mass (HLM); and thousand kernel weight (TKW) were also examined. A combined ANOVA revealed significant differences (p0.001) among the interaction of genotypes by environments (GE) for all traits except PF. This implies that the performance of wheat genotypes across sites was also different, and therefore, necessitated separate analysis of variance for each site. Significant differences (p0.001) among genotypes (G), water regimes (WR), and the interaction of genotypes by water regime (GWR) were observed for all studied quality traits except PF in both sites. GWR showed no significant differences for TKW in the ZAN site. The stability in the performance of genotypes across water regimes was further determined. G38 was stable for wet gluten; G31 and G26 were stable for PF; G36 was stable for HLM; and G11, G15, and G29 were stable for TKW at the UFH site. G6 was stable for both WG and PF; G13 and G15 were stable for HLM; and G35, G21, and G40 were stable for TKW at the ZAN site. These results suggest that the quality of wheat grains was affected under drought stress conditions except PF. Average grain yield data under both stressed (Ys) and optimum (Yp) conditions was used to compute a number of different drought tolerance indices. These include mean productivity (MP); geometric mean productivity (GMP); harmonic mean (HM); Tolerance index (TOL), stress susceptible index (SSI), sensitive drought index (SDI), and stress tolerance index (STI). The aim was to identify appropriate drought tolerance indices that can be used as selection tools under drought stress. MP, GMP, and HM were the more appropriate indices as they had a strong and positive correlation with grain yield under both drought and optimum conditions. However, genotypes G5, G22, G8, and G21 were more tolerant and stable as they showed high mean values. Based on the results, G19, G16, G2, and G20 were more sensitive to drought as they showed low values of MP, GMP, and HM. Overall, genotype: G5, G21, G22, and G33 are recommended for production under drought and optimum conditions, as they showed stable performance across water regimes. Principal component analysis also revealed that MP, GMP, and HM were the only indices that had positive loadings into the first principal component. , Thesis (MSc) -- Faculty of Science and Agriculture, 2023
- Full Text:
- Date Issued: 2023
- Authors: Mzileni L S
- Date: 2023
- Subjects: Bonanza farms , Wheat , Drought - tolerant plants
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/27732 , vital:69397
- Description: Wheat is generally one of the dominant crops globally, being mainly used for human food and livestock feed. Due to climate change, drought makes it challenging to produce enough wheat mostly under dryland production regions in South Africa. Drought stress has severely reduced wheat yield by up to 70 percent, and adversely compromised wheat grain quality. The adoption of drought-tolerant cultivars offers a sustainable and low-cost solution for increasing wheat yields and minimise importing the crop to meet national requirements. The main objective of this study was to investigate the response of different wheat genotypes to drought and optimum conditions in the Eastern Cape Province, South Africa. Forty diverse wheat genotypes were evaluated in this study. The specific objectives were: (i) to evaluate the response of wheat genotypes under optimum and drought-stressed field conditions; (ii) to determine the effect of terminal drought stress on wheat grain quality composition; and (iii) to identify appropriate drought tolerance indices that can be used as selection tools under field conditions. This study was conducted in the field using a 5x8 alpha lattice design, replicated twice under two water regimes (drought and optimum) over two consecutive winter seasons of 2020 and 2021 at two different sites namely University of Fort Hare Research Farm in Alice, and Zanyokwe irrigation scheme in Keiskamahoek. Drought stress was imposed from 50% flowering up to physiological maturity. Data on agro-physiological traits such as duration to heading (DTH); flowering (DTF); maturity (DTM); plant height (HT); spike length (SL); number of spikelets per spike (SPS); kernels per spike (KPS); and grain yield (GY (kg/ha)) was subjected to the analysis of variance using Genstat 18th edition. As the study took place over two sites, a combined ANOVA table revealed significant differences (p0.001) among genotypes, and all interactions such as genotype by water regime (GWR); genotype by seasons (GS) for all studied traits. Notably, the extent and severity of drought differed between geographical regions and between seasons. This necessitated the adoption of the additive main effect and multiplicative interaction analysis (AMMI) for the identification of stable genotypes under two different water regimes over two sites. Regarding grain yield, superior and/or stable genotypes included G5 (4334 kg/ha under optimum, and 2871kg/ha under drought), and G22 (4418 kg/ha under optimum, and 2624kg/ha under drought) at the UFH site. G21 (3194 kg/ha under optimum, and 2938 kg/ha under drought), G33 (2552kg/ha under optimum, and 3810 kg/ha under drought), and G35 (2688 kg/ha under optimum, and 3309 kg/ha under drought) at the ZAN site. Stable genotypes across sites included G21 and G33. There were generally weak correlations between agro-physiological traits and grain yield. From the experiment, grain quality traits such as fixed protein (PF); wet gluten (WG); hectolitre mass (HLM); and thousand kernel weight (TKW) were also examined. A combined ANOVA revealed significant differences (p0.001) among the interaction of genotypes by environments (GE) for all traits except PF. This implies that the performance of wheat genotypes across sites was also different, and therefore, necessitated separate analysis of variance for each site. Significant differences (p0.001) among genotypes (G), water regimes (WR), and the interaction of genotypes by water regime (GWR) were observed for all studied quality traits except PF in both sites. GWR showed no significant differences for TKW in the ZAN site. The stability in the performance of genotypes across water regimes was further determined. G38 was stable for wet gluten; G31 and G26 were stable for PF; G36 was stable for HLM; and G11, G15, and G29 were stable for TKW at the UFH site. G6 was stable for both WG and PF; G13 and G15 were stable for HLM; and G35, G21, and G40 were stable for TKW at the ZAN site. These results suggest that the quality of wheat grains was affected under drought stress conditions except PF. Average grain yield data under both stressed (Ys) and optimum (Yp) conditions was used to compute a number of different drought tolerance indices. These include mean productivity (MP); geometric mean productivity (GMP); harmonic mean (HM); Tolerance index (TOL), stress susceptible index (SSI), sensitive drought index (SDI), and stress tolerance index (STI). The aim was to identify appropriate drought tolerance indices that can be used as selection tools under drought stress. MP, GMP, and HM were the more appropriate indices as they had a strong and positive correlation with grain yield under both drought and optimum conditions. However, genotypes G5, G22, G8, and G21 were more tolerant and stable as they showed high mean values. Based on the results, G19, G16, G2, and G20 were more sensitive to drought as they showed low values of MP, GMP, and HM. Overall, genotype: G5, G21, G22, and G33 are recommended for production under drought and optimum conditions, as they showed stable performance across water regimes. Principal component analysis also revealed that MP, GMP, and HM were the only indices that had positive loadings into the first principal component. , Thesis (MSc) -- Faculty of Science and Agriculture, 2023
- Full Text:
- Date Issued: 2023
Know thy enemy: Investigating genetic contributions from putative parents of invasive Nymphaea mexicana hybrids in South Africa as part of efforts to develop biological control
- Reid, Megan K, Paterson, Iain D, Coetzee, Julie A, Gettys, Lyn A, Hill, Martin P
- Authors: Reid, Megan K , Paterson, Iain D , Coetzee, Julie A , Gettys, Lyn A , Hill, Martin P
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423540 , vital:72070 , xlink:href="https://doi.org/10.1016/j.biocontrol.2023.105291"
- Description: Hybridisation of alien invasive plants complicates efforts to develop biological control, because variations in the genetic makeup of the target plant can impact the survival of host specific agents that have evolved adaptations specific to the original host. To maximise the likelihood of success in a biological control program, potential agents should therefore be collected from populations in the region of origin that are genetically similar to plants in the invaded range. Molecular markers are useful tools to understand genetic contributions in hybrid populations, especially where morphological differentiation is difficult. Nymphaea mexicana Zuccarini (Nymphaeaceae) is an invasive alien plant in South Africa that is being targeted for biological control, but hybrids with intermediate morphological traits are also present at several sites. In this study, ISSR (inter simple sequence repeats) and ITS (internal transcribed spacer) markers were used to determine which Nymphaea species are likely to be putative parents of these hybrids, and morphological characters were also investigated to determine if genetic and morphological traits matched. Two major hybrid groups were identified, with one group clustering with Nymphaea odorata Aiton and the other clustering with Nymphaea alba L. A third, smaller group clustered with Nymphaea tetragona Georgi, whereas the remaining samples clustered with pure N. mexicana from the native range. Morphological features agreed with deductions drawn from molecular data. These results allow us to focus efforts to find compatible biological control agents and better understand the complicated genetic structure of N. mexicana and Nymphaea hybrids in South Africa.
- Full Text:
- Date Issued: 2023
- Authors: Reid, Megan K , Paterson, Iain D , Coetzee, Julie A , Gettys, Lyn A , Hill, Martin P
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423540 , vital:72070 , xlink:href="https://doi.org/10.1016/j.biocontrol.2023.105291"
- Description: Hybridisation of alien invasive plants complicates efforts to develop biological control, because variations in the genetic makeup of the target plant can impact the survival of host specific agents that have evolved adaptations specific to the original host. To maximise the likelihood of success in a biological control program, potential agents should therefore be collected from populations in the region of origin that are genetically similar to plants in the invaded range. Molecular markers are useful tools to understand genetic contributions in hybrid populations, especially where morphological differentiation is difficult. Nymphaea mexicana Zuccarini (Nymphaeaceae) is an invasive alien plant in South Africa that is being targeted for biological control, but hybrids with intermediate morphological traits are also present at several sites. In this study, ISSR (inter simple sequence repeats) and ITS (internal transcribed spacer) markers were used to determine which Nymphaea species are likely to be putative parents of these hybrids, and morphological characters were also investigated to determine if genetic and morphological traits matched. Two major hybrid groups were identified, with one group clustering with Nymphaea odorata Aiton and the other clustering with Nymphaea alba L. A third, smaller group clustered with Nymphaea tetragona Georgi, whereas the remaining samples clustered with pure N. mexicana from the native range. Morphological features agreed with deductions drawn from molecular data. These results allow us to focus efforts to find compatible biological control agents and better understand the complicated genetic structure of N. mexicana and Nymphaea hybrids in South Africa.
- Full Text:
- Date Issued: 2023
Lessons learned from the translation of the Internalised Stigma of Mental Illness (ISMI) scale into isiXhosa for use with South African Xhosa people with schizophrenia
- Matshabane, Olivia P, Appelbaum, Paul S, Faure, Marlyn C, Marshall, Patricia A, Stein, Dan J, de Vries, Jantina, Campbell, Megan M
- Authors: Matshabane, Olivia P , Appelbaum, Paul S , Faure, Marlyn C , Marshall, Patricia A , Stein, Dan J , de Vries, Jantina , Campbell, Megan M
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/450689 , vital:74974 , xlink:href="https://doi.org/10.1177/13634615231168461"
- Description: Internalised stigma is highly prevalent among people with mental illness. This is concerning because internalised stigma is often associated with negative consequences affecting individuals’ personal, familial, social, and overall wellbeing, employment opportunities and recovery. Currently, there is no psychometrically validated instrument to measure internalised stigma among Xhosa people in their home language. Our study aimed to translate the Internalised Stigma of Mental Illness (ISMI) scale into isiXhosa. Following WHO guidelines, the ISMI scale was translated using a five-stage translation design which included (i) forward-translation, (ii) back-translation, (iii) committee approach, (iv) quantitative piloting, and (v) qualitative piloting using cognitive interviews. The ISMI isiXhosa version (ISMI-X) underwent psychometric testing to establish utility, within-scale validity, convergent, divergent, and content validity (assessed using frequency of endorsements and cognitive interviewing) with n = 65 Xhosa people with schizophrenia. The resultant ISMI-X scale demonstrated good psychometric utility, internal consistency for the overall scale (α = .90) and most subscales (α > .70, except the Stigma Resistance subscale where α = .57), convergent validity between the ISMI Discrimination Experiences subscale and the Discrimination and Stigma (DISC) scale's Treated Unfairly subscale (r = .34, p = .03) and divergent validity between the ISMI Stigma Resistance and DISC Treated Unfairly subscales (r = .13, p = .49). But more importantly the study provides valuable insights into strengths and limitations of the present translation design. Specifically, validation methods such as assessing frequency of endorsements of scale items and using cognitive interviewing to establish conceptual clarity and relevance of items may be useful in small piloting sample sizes.
- Full Text:
- Date Issued: 2023
- Authors: Matshabane, Olivia P , Appelbaum, Paul S , Faure, Marlyn C , Marshall, Patricia A , Stein, Dan J , de Vries, Jantina , Campbell, Megan M
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/450689 , vital:74974 , xlink:href="https://doi.org/10.1177/13634615231168461"
- Description: Internalised stigma is highly prevalent among people with mental illness. This is concerning because internalised stigma is often associated with negative consequences affecting individuals’ personal, familial, social, and overall wellbeing, employment opportunities and recovery. Currently, there is no psychometrically validated instrument to measure internalised stigma among Xhosa people in their home language. Our study aimed to translate the Internalised Stigma of Mental Illness (ISMI) scale into isiXhosa. Following WHO guidelines, the ISMI scale was translated using a five-stage translation design which included (i) forward-translation, (ii) back-translation, (iii) committee approach, (iv) quantitative piloting, and (v) qualitative piloting using cognitive interviews. The ISMI isiXhosa version (ISMI-X) underwent psychometric testing to establish utility, within-scale validity, convergent, divergent, and content validity (assessed using frequency of endorsements and cognitive interviewing) with n = 65 Xhosa people with schizophrenia. The resultant ISMI-X scale demonstrated good psychometric utility, internal consistency for the overall scale (α = .90) and most subscales (α > .70, except the Stigma Resistance subscale where α = .57), convergent validity between the ISMI Discrimination Experiences subscale and the Discrimination and Stigma (DISC) scale's Treated Unfairly subscale (r = .34, p = .03) and divergent validity between the ISMI Stigma Resistance and DISC Treated Unfairly subscales (r = .13, p = .49). But more importantly the study provides valuable insights into strengths and limitations of the present translation design. Specifically, validation methods such as assessing frequency of endorsements of scale items and using cognitive interviewing to establish conceptual clarity and relevance of items may be useful in small piloting sample sizes.
- Full Text:
- Date Issued: 2023
Local peoples’ knowledge and perceptions of Australian wattle (Acacia) species invasion, ecosystem services and disservices in grassland landscapes, South Africa
- Yapi, Thozamile S, Shackleton, Charlie M, Le Maitre, David C, Dziba, Luthando E
- Authors: Yapi, Thozamile S , Shackleton, Charlie M , Le Maitre, David C , Dziba, Luthando E
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/399791 , vital:69559 , xlink:href="https://doi.org/10.1080/26395916.2023.2177495"
- Description: Many alien tree species were introduced into grassland ecosystems in South Africa by the commercial forestry industry for paper and timber for furniture. Over decades some of these introduced species escaped into neighbouring farms and community land. Adult trees from these alien species now provide other ecosystem services, notably fuelwood. Depending on the spatio-temporal context, many of these species can also negatively affect ecosystem services. We collected interview data from commercial and communal farmers in the upper Umzimvubu catchment in South Africa to compare farmers’ knowledge and perceptions of invasive wattle species invasion and their associated ecosystem services and disservices. Fuelwood and fencing poles were the most common uses of wattle by commercial (83%; 67%) and communal (99%; 49%) farmers. On the other hand, the reduction of grass cover and loss of grazing land were the most commonly mentioned negative impacts of wattles by commercial (83%; 75%) and communal (92%; 80%) farmers. Although both groups recognise the importance of wattles in providing ecosystem services, most communal farmers perceived wattles to have more negative effects than benefits. The findings demonstrate that both farmer groups highly depend on ecosystem services and are affected by disservices of wattles. However, while large-scale commercial households favour the presence of wattles in the landscape, communal households prefer complete removal of the wattles from the landscape. This may be due to lack of locally available alternative options or inability to replace or purchase ecosystem services affected by wattles from other sources or markets like commercial farmers.
- Full Text:
- Date Issued: 2023
- Authors: Yapi, Thozamile S , Shackleton, Charlie M , Le Maitre, David C , Dziba, Luthando E
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/399791 , vital:69559 , xlink:href="https://doi.org/10.1080/26395916.2023.2177495"
- Description: Many alien tree species were introduced into grassland ecosystems in South Africa by the commercial forestry industry for paper and timber for furniture. Over decades some of these introduced species escaped into neighbouring farms and community land. Adult trees from these alien species now provide other ecosystem services, notably fuelwood. Depending on the spatio-temporal context, many of these species can also negatively affect ecosystem services. We collected interview data from commercial and communal farmers in the upper Umzimvubu catchment in South Africa to compare farmers’ knowledge and perceptions of invasive wattle species invasion and their associated ecosystem services and disservices. Fuelwood and fencing poles were the most common uses of wattle by commercial (83%; 67%) and communal (99%; 49%) farmers. On the other hand, the reduction of grass cover and loss of grazing land were the most commonly mentioned negative impacts of wattles by commercial (83%; 75%) and communal (92%; 80%) farmers. Although both groups recognise the importance of wattles in providing ecosystem services, most communal farmers perceived wattles to have more negative effects than benefits. The findings demonstrate that both farmer groups highly depend on ecosystem services and are affected by disservices of wattles. However, while large-scale commercial households favour the presence of wattles in the landscape, communal households prefer complete removal of the wattles from the landscape. This may be due to lack of locally available alternative options or inability to replace or purchase ecosystem services affected by wattles from other sources or markets like commercial farmers.
- Full Text:
- Date Issued: 2023
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:
- Date Issued: 2023
- 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:
- Date Issued: 2023
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:
- Date Issued: 2023
- 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:
- Date Issued: 2023
Microbial Community Responses to Alterations in Historical Fire Regimes in Montane Grasslands
- Gokul, Jarishma K, Matcher, Gwynneth, Dames, Joanna F, Nkangala, Kuhle, Gordijn, Paul J, Barker, Nigel P
- Authors: Gokul, Jarishma K , Matcher, Gwynneth , 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:
- Date Issued: 2023
- Authors: Gokul, Jarishma K , Matcher, Gwynneth , 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:
- Date Issued: 2023