Social-ecological change: insights from the Southern African Program on Ecosystem Change and Society
- Biggs, Reinette, Clements, Hayley S, Cumming, Graeme S, Cundill, Georgina, de Vos, Alta, Hamann, Maike, Luvuno, Linda, Roux, Dirk J, Selomane, Odirlwe, Blanchard, Ryan, Cockburn, Jessica J, Dziba, Luthando E, Esler, Karen J, Fabricius, Christo, Henriksson, Rebecka, Kotschy, Karen, Lindborg, Regina, Masterson, Vanessa A, Nel, Jeanne L, O'Farrell, Patrick, Palmer, Carolyn G, Pereira, Laura, Pollard, Sharon, Preiser, Rika, Scholes, Robert J, Shackleton, Charlie M, Shackleton, Sheona E, Sitas, Nadia, Slingsby, Jasper A, Spierenburg, Maria, Tengö, Maria, Reyers, Belinda
- Authors: Biggs, Reinette , Clements, Hayley S , Cumming, Graeme S , Cundill, Georgina , de Vos, Alta , Hamann, Maike , Luvuno, Linda , Roux, Dirk J , Selomane, Odirlwe , Blanchard, Ryan , Cockburn, Jessica J , Dziba, Luthando E , Esler, Karen J , Fabricius, Christo , Henriksson, Rebecka , Kotschy, Karen , Lindborg, Regina , Masterson, Vanessa A , Nel, Jeanne L , O'Farrell, Patrick , Palmer, Carolyn G , Pereira, Laura , Pollard, Sharon , Preiser, Rika , Scholes, Robert J , Shackleton, Charlie M , Shackleton, Sheona E , Sitas, Nadia , Slingsby, Jasper A , Spierenburg, Maria , Tengö, Maria , Reyers, Belinda
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/399817 , vital:69561 , xlink:href="https://doi.org/10.1080/26395916.2022.2097478"
- Description: Social-ecological systems (SES) research has emerged as an important area of sustainability science, informing and supporting pressing issues of transformation towards more sustainable, just and equitable futures. To date, much SES research has been done in or from the Global North, where the challenges and contexts for supporting sustainability transformations are substantially different from the Global South. This paper synthesises emerging insights on SES dynamics that can inform actions and advance research to support sustainability transformations specifically in the southern African context. The paper draws on work linked to members of the Southern African Program on Ecosystem Change and Society (SAPECS), a leading SES research network in the region, synthesizing key insights with respect to the five core themes of SAPECS: (i) transdisciplinary and engaged research, (ii) ecosystem services and human well-being, (iii) governance institutions and management practices, (iv) spatial relationships and cross-scale connections, and (v) regime shifts, traps and transformations. For each theme, we focus on insights that are particularly novel, interesting or important in the southern African context, and reflect on key research gaps and emerging frontiers for SES research in the region going forward. Such place-based insights are important for understanding the variation in SES dynamics around the world, and are crucial for informing a context-sensitive global agenda to foster sustainability transformations at local to global scales.
- Full Text:
- Date Issued: 2022
Social-ecological change: insights from the Southern African Program on Ecosystem Change and Society
- Authors: Biggs, Reinette , Clements, Hayley S , Cumming, Graeme S , Cundill, Georgina , de Vos, Alta , Hamann, Maike , Luvuno, Linda , Roux, Dirk J , Selomane, Odirlwe , Blanchard, Ryan , Cockburn, Jessica J , Dziba, Luthando E , Esler, Karen J , Fabricius, Christo , Henriksson, Rebecka , Kotschy, Karen , Lindborg, Regina , Masterson, Vanessa A , Nel, Jeanne L , O'Farrell, Patrick , Palmer, Carolyn G , Pereira, Laura , Pollard, Sharon , Preiser, Rika , Scholes, Robert J , Shackleton, Charlie M , Shackleton, Sheona E , Sitas, Nadia , Slingsby, Jasper A , Spierenburg, Maria , Tengö, Maria , Reyers, Belinda
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/399817 , vital:69561 , xlink:href="https://doi.org/10.1080/26395916.2022.2097478"
- Description: Social-ecological systems (SES) research has emerged as an important area of sustainability science, informing and supporting pressing issues of transformation towards more sustainable, just and equitable futures. To date, much SES research has been done in or from the Global North, where the challenges and contexts for supporting sustainability transformations are substantially different from the Global South. This paper synthesises emerging insights on SES dynamics that can inform actions and advance research to support sustainability transformations specifically in the southern African context. The paper draws on work linked to members of the Southern African Program on Ecosystem Change and Society (SAPECS), a leading SES research network in the region, synthesizing key insights with respect to the five core themes of SAPECS: (i) transdisciplinary and engaged research, (ii) ecosystem services and human well-being, (iii) governance institutions and management practices, (iv) spatial relationships and cross-scale connections, and (v) regime shifts, traps and transformations. For each theme, we focus on insights that are particularly novel, interesting or important in the southern African context, and reflect on key research gaps and emerging frontiers for SES research in the region going forward. Such place-based insights are important for understanding the variation in SES dynamics around the world, and are crucial for informing a context-sensitive global agenda to foster sustainability transformations at local to global scales.
- Full Text:
- Date Issued: 2022
The legacy of colonial and apartheid eras on the distribution, composition and representation of street trees in South Africa
- Shackleton, Charlie M, Gwedla, Nananmhla, Davoren, Elandrie
- Authors: Shackleton, Charlie M , Gwedla, Nananmhla , Davoren, Elandrie
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433984 , vital:73017 , ISBN 9781003054672 , https://doi.org/10.4324/9781003054672
- Description: South Africa is a country of social, economic and racial contrasts and inequities, the roots of which can be traced back to the colonial and the post-colonial, racist apartheid periods. During these periods, urban black South Africans were restricted to living in specifically designated neighbourhoods apart from white citizens. These areas became characterised by institutionalised underdevelopment, insufficient infrastructure, limited opportunities and deep poverty. Despite the democratic transition in the mid-1990s, the imprints of the previous institutionalised segregation remain visible in many facets of the spatial geography of South African towns and cities. The legacies of colonialism and apartheid remain strongly expressed in street trees in terms of where they are found in the urban areas (i.e. very few in the former black neighbourhoods) and the provenance of prevalent species (mostly non-native species in older areas). Similarities to and reproduction of colonial approaches are evident in even contemporary initiatives such as the national social housing programme, the national Champion Trees inventory and the naming of streets after non-native species. This has translated into apathy or antagonism towards street trees in some regions by officials and the public.
- Full Text:
- Date Issued: 2022
- Authors: Shackleton, Charlie M , Gwedla, Nananmhla , Davoren, Elandrie
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433984 , vital:73017 , ISBN 9781003054672 , https://doi.org/10.4324/9781003054672
- Description: South Africa is a country of social, economic and racial contrasts and inequities, the roots of which can be traced back to the colonial and the post-colonial, racist apartheid periods. During these periods, urban black South Africans were restricted to living in specifically designated neighbourhoods apart from white citizens. These areas became characterised by institutionalised underdevelopment, insufficient infrastructure, limited opportunities and deep poverty. Despite the democratic transition in the mid-1990s, the imprints of the previous institutionalised segregation remain visible in many facets of the spatial geography of South African towns and cities. The legacies of colonialism and apartheid remain strongly expressed in street trees in terms of where they are found in the urban areas (i.e. very few in the former black neighbourhoods) and the provenance of prevalent species (mostly non-native species in older areas). Similarities to and reproduction of colonial approaches are evident in even contemporary initiatives such as the national social housing programme, the national Champion Trees inventory and the naming of streets after non-native species. This has translated into apathy or antagonism towards street trees in some regions by officials and the public.
- Full Text:
- Date Issued: 2022
The use and value of wild harvested provisioning ecosystem services along a landscape heterogeneity gradient in rural South Africa
- Herd-Hoare, Shannon C, Shackleton, Charlie M
- Authors: Herd-Hoare, Shannon C , Shackleton, Charlie M
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/401341 , vital:69727 , xlink:href="https://doi.org/10.1080/26395916.2022.2140711"
- Description: Provisioning ecosystem services (PES) are typically crucial to rural livelihoods, especially in developing countries. However, the links between PES and local biodiversity or landscape heterogeneity are poorly explored. Here, we examined the extent of use and value of locally harvested wild, terrestrial and marine PES (such as wild foods, traditional medicines, firewood, building materials and others) in three villages (35–40 households per village) along a gradient of decreasing landscape heterogeneity. Households at the site with the highest landscape heterogeneity used a greater array of PES (9 ± 4) compared to the intermediate (5 ± 3) and least heterogenous (0.9 ± 0.8) sites. This resulted in a significantly greater annual value of PES to local livelihoods at the most diverse site (US$2 656 ± 2 587 per household), compared to US$1 120 ± 1 313 at the intermediate site and only US$105 ± 193 at the least heterogeneous site. This study shows the importance of access to a diversity of landscapes and PES to support rural livelihoods, which is frequently overlooked in PES valuation studies and in situations of land use change where landscape heterogeneity may decline.
- Full Text:
- Date Issued: 2022
- Authors: Herd-Hoare, Shannon C , Shackleton, Charlie M
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/401341 , vital:69727 , xlink:href="https://doi.org/10.1080/26395916.2022.2140711"
- Description: Provisioning ecosystem services (PES) are typically crucial to rural livelihoods, especially in developing countries. However, the links between PES and local biodiversity or landscape heterogeneity are poorly explored. Here, we examined the extent of use and value of locally harvested wild, terrestrial and marine PES (such as wild foods, traditional medicines, firewood, building materials and others) in three villages (35–40 households per village) along a gradient of decreasing landscape heterogeneity. Households at the site with the highest landscape heterogeneity used a greater array of PES (9 ± 4) compared to the intermediate (5 ± 3) and least heterogenous (0.9 ± 0.8) sites. This resulted in a significantly greater annual value of PES to local livelihoods at the most diverse site (US$2 656 ± 2 587 per household), compared to US$1 120 ± 1 313 at the intermediate site and only US$105 ± 193 at the least heterogeneous site. This study shows the importance of access to a diversity of landscapes and PES to support rural livelihoods, which is frequently overlooked in PES valuation studies and in situations of land use change where landscape heterogeneity may decline.
- Full Text:
- Date Issued: 2022
Working in poverty: Informal employment of household gardeners in Eastern Cape towns, South Africa
- King, Andrew, Shackleton, Charlie M
- Authors: King, Andrew , Shackleton, Charlie M
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/401398 , vital:69731 , xlink:href="https://doi.org/10.1080/0376835X.2021.1940867"
- Description: In South Africa there has been relatively little consideration of the informal employment offered to domestic household workers and gardeners. Here we report on the number and profile of gardeners employed by private households and the wage and satisfaction rates in 12 towns of the Eastern Cape. Over 98% of the informal gardeners were male, middle-aged and with limited formal schooling. Approximately 58% of middle and upper income households employed a gardener, at a mean daily rate of R112.20 in 2019. This equated to 13 170 gardeners earning a total wage bill of R139 million p.a. across the 12 towns, which scales up to 0.7–1 million informal gardeners nationally earning approximately R10–14 billion per year. However, daily remuneration was insufficient to cover basic needs, and slightly more than half of the gardeners would prefer a different job, indicating the survivalist nature of the sector.
- Full Text:
- Date Issued: 2022
- Authors: King, Andrew , Shackleton, Charlie M
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/401398 , vital:69731 , xlink:href="https://doi.org/10.1080/0376835X.2021.1940867"
- Description: In South Africa there has been relatively little consideration of the informal employment offered to domestic household workers and gardeners. Here we report on the number and profile of gardeners employed by private households and the wage and satisfaction rates in 12 towns of the Eastern Cape. Over 98% of the informal gardeners were male, middle-aged and with limited formal schooling. Approximately 58% of middle and upper income households employed a gardener, at a mean daily rate of R112.20 in 2019. This equated to 13 170 gardeners earning a total wage bill of R139 million p.a. across the 12 towns, which scales up to 0.7–1 million informal gardeners nationally earning approximately R10–14 billion per year. However, daily remuneration was insufficient to cover basic needs, and slightly more than half of the gardeners would prefer a different job, indicating the survivalist nature of the sector.
- Full Text:
- Date Issued: 2022
‘My friends would laugh at me’: embedding the dominant heterosexual script in the talk of primary school students
- Morison, Tracy, Macleod, Catriona I, Lynch, Ingrid
- Authors: Morison, Tracy , Macleod, Catriona I , Lynch, Ingrid
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441186 , vital:73864 , xlink:href="https://doi.org/10.1080/09540253.2021.1929856"
- Description: The dominant ‘heterosexual script’ positions men as sexually desiring subjects who initiate sex and use active displays of power to attract women, and women as passive sexual objects who use indirect means to attract men (e.g. physical appearance). While much research has highlighted how this script is deployed in high school settings, less work has attended to primary schools. We demonstrate how the script operates in the talk of primary school students in low resource South African schools. Data were generated in group discussions conducted for a mid-term review of a school-based sexual violence prevention programme. We show how the heterosexual script is embedded in students’ accounts through the regulatory mechanisms of interpersonal and social risks: threats of being ‘dumped’, sexual coercion, violence, and humiliation. These risks are learnt from an early age and may outweigh sexuality education messaging provided later on, which has implications for such interventions. To address this we advocate for early engagement with young people using a dialogical approach that creates a relational context for resistance to inequitable sexual scripts.
- Full Text:
- Date Issued: 2022
- Authors: Morison, Tracy , Macleod, Catriona I , Lynch, Ingrid
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441186 , vital:73864 , xlink:href="https://doi.org/10.1080/09540253.2021.1929856"
- Description: The dominant ‘heterosexual script’ positions men as sexually desiring subjects who initiate sex and use active displays of power to attract women, and women as passive sexual objects who use indirect means to attract men (e.g. physical appearance). While much research has highlighted how this script is deployed in high school settings, less work has attended to primary schools. We demonstrate how the script operates in the talk of primary school students in low resource South African schools. Data were generated in group discussions conducted for a mid-term review of a school-based sexual violence prevention programme. We show how the heterosexual script is embedded in students’ accounts through the regulatory mechanisms of interpersonal and social risks: threats of being ‘dumped’, sexual coercion, violence, and humiliation. These risks are learnt from an early age and may outweigh sexuality education messaging provided later on, which has implications for such interventions. To address this we advocate for early engagement with young people using a dialogical approach that creates a relational context for resistance to inequitable sexual scripts.
- Full Text:
- Date Issued: 2022
“It’s just like a waiting room”: The lived experiences of psychology students seeking professional training programme admission in South Africa
- Duiker, Adeline, Booysen, Duane D
- Authors: Duiker, Adeline , Booysen, Duane D
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/454068 , vital:75307 , xlink:href="https://doi.org/10.1080/14330237.2022.2075620"
- Description: We aimed to explore the lived experiences of South African psychology students of professional training opportunities and career prospects. Informants were eight psychology Honours students attending a South African public university. Interpretive phenomenological analysis of the data yielded four themes recurrent in most participant’s experiences: (i) personal capacity development; (ii) feeling stuck with nothing; (iii) sense of disillusionment and uncertainty; and (iv) low career prospects. The students considered psychology studies beneficial to their personal growth although they were uncertain about their futures, accessing professional training programs, and employment in the field. The uncertainty to access professional training contributes to a sense of unemployability in the South African mental health field.
- Full Text:
- Date Issued: 2022
- Authors: Duiker, Adeline , Booysen, Duane D
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/454068 , vital:75307 , xlink:href="https://doi.org/10.1080/14330237.2022.2075620"
- Description: We aimed to explore the lived experiences of South African psychology students of professional training opportunities and career prospects. Informants were eight psychology Honours students attending a South African public university. Interpretive phenomenological analysis of the data yielded four themes recurrent in most participant’s experiences: (i) personal capacity development; (ii) feeling stuck with nothing; (iii) sense of disillusionment and uncertainty; and (iv) low career prospects. The students considered psychology studies beneficial to their personal growth although they were uncertain about their futures, accessing professional training programs, and employment in the field. The uncertainty to access professional training contributes to a sense of unemployability in the South African mental health field.
- Full Text:
- Date Issued: 2022
Economic evaluation of chemical and biological control of four aquatic weeds in South Africa
- Maluleke, Mary, Fraser, Gavin C G, Hill, Martin P
- Authors: Maluleke, Mary , Fraser, Gavin C G , Hill, Martin P
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/453170 , vital:75228 , xlink:href="https://doi.org/10.1080/09583157.2021.1900783"
- Description: Invasive alien plants (IAPs) pose a threat to biodiversity and the economy of the countries they invade. In South Africa, the Department of Environment, Forestry and Fisheries, Natural Resources Management Programmes, previously The Working for Water Programme (WfW) is tasked with controlling IAPs in a way that protects the environment, as well as producing maximum return to society through poverty alleviation. Biological control is one of the management tools used to control IAPs in South Africa. Four aquatic weeds, Pista stratiotes, Salvinia molesta, Azolla filiculoides and Myriophyllum aquaticum, are under complete biological control in South Africa. However, in the absence of biological agents, the WfW programme would have used herbicides to control these weeds. This paper presents a retrospective analysis of the relative herbicide cost-saving associated with the use of biological control instead of chemical control. The study used cost benefit analysis (CBA) framework with an 8% discount rate. The estimated cost of the biological control on all four aquatic weeds was about R7.8 million, while the estimated cost of chemical control to achieve the same level of control varied between R150 million and R1 billion, depending on the method of application and number of follow up operations. Benefit to cost ratios varied between 90:1 and 631:1, again depending on method of application and number of follow up sprays. The results remained robust under a 5% and 10% sensitivity test and show that biological control is the most cost-effective management option for aquatic weeds in South Africa.
- Full Text:
- Date Issued: 2021
- Authors: Maluleke, Mary , Fraser, Gavin C G , Hill, Martin P
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/453170 , vital:75228 , xlink:href="https://doi.org/10.1080/09583157.2021.1900783"
- Description: Invasive alien plants (IAPs) pose a threat to biodiversity and the economy of the countries they invade. In South Africa, the Department of Environment, Forestry and Fisheries, Natural Resources Management Programmes, previously The Working for Water Programme (WfW) is tasked with controlling IAPs in a way that protects the environment, as well as producing maximum return to society through poverty alleviation. Biological control is one of the management tools used to control IAPs in South Africa. Four aquatic weeds, Pista stratiotes, Salvinia molesta, Azolla filiculoides and Myriophyllum aquaticum, are under complete biological control in South Africa. However, in the absence of biological agents, the WfW programme would have used herbicides to control these weeds. This paper presents a retrospective analysis of the relative herbicide cost-saving associated with the use of biological control instead of chemical control. The study used cost benefit analysis (CBA) framework with an 8% discount rate. The estimated cost of the biological control on all four aquatic weeds was about R7.8 million, while the estimated cost of chemical control to achieve the same level of control varied between R150 million and R1 billion, depending on the method of application and number of follow up operations. Benefit to cost ratios varied between 90:1 and 631:1, again depending on method of application and number of follow up sprays. The results remained robust under a 5% and 10% sensitivity test and show that biological control is the most cost-effective management option for aquatic weeds in South Africa.
- Full Text:
- Date Issued: 2021
Futures analysis
- Hichert, Tanya, Biggs, Reinette, de Vos, Alta
- Authors: Hichert, Tanya , Biggs, Reinette , de Vos, Alta
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433871 , vital:73006 , ISBN 9781000401516 , https://library.oapen.org/handle/20.500.12657/49560
- Description: Futures analysis methods can help people to think constructively and systematically about the future and advance our understanding of change and uncertainty in complex social-ecological systems (SES). This is important because there is not one single predictable future but multiple ones, depending on the complex, unpredictable interplays and interactions of actors, institutions, ecological processes and other elements of the system and its dynamics. Actively developing ideas, images and/or stories about different futures can enable us to make different choices and take different actions in the present in relation to, for example, risk mitigation, adaptation, resource allocation and strategy development, which can help build more sustainable and just futures.
- Full Text:
- Date Issued: 2021
- Authors: Hichert, Tanya , Biggs, Reinette , de Vos, Alta
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433871 , vital:73006 , ISBN 9781000401516 , https://library.oapen.org/handle/20.500.12657/49560
- Description: Futures analysis methods can help people to think constructively and systematically about the future and advance our understanding of change and uncertainty in complex social-ecological systems (SES). This is important because there is not one single predictable future but multiple ones, depending on the complex, unpredictable interplays and interactions of actors, institutions, ecological processes and other elements of the system and its dynamics. Actively developing ideas, images and/or stories about different futures can enable us to make different choices and take different actions in the present in relation to, for example, risk mitigation, adaptation, resource allocation and strategy development, which can help build more sustainable and just futures.
- Full Text:
- Date Issued: 2021
Interviews and surveys
- Shackleton, Sheona E, Bezerra, Joana C, Cockburn, Jessica J, Reed, Maureen G, Abu, Razak
- Authors: Shackleton, Sheona E , Bezerra, Joana C , Cockburn, Jessica J , Reed, Maureen G , Abu, Razak
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433914 , vital:73009 , ISBN 9781000401516 , https://library.oapen.org/handle/20.500.12657/49560
- Description: This chapter is closely related to the following approaches and methods in this handbook: systems scoping (Chapter 5), participatory data collection (Chapter 8), facilitated dialogues (Chapter 9), futures analysis (Chapter 10), qualitative content analysis (Chapter 19), comparative case study analysis (Chapter 20), institutional analysis (Chapter 22), network analysis (Chapter 23), spatial mapping and analysis (Chapter 24), historical assessment (Chapter 25), and livelihood and vulnerability analysis (Chapter 32).
- Full Text:
- Date Issued: 2021
- Authors: Shackleton, Sheona E , Bezerra, Joana C , Cockburn, Jessica J , Reed, Maureen G , Abu, Razak
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433914 , vital:73009 , ISBN 9781000401516 , https://library.oapen.org/handle/20.500.12657/49560
- Description: This chapter is closely related to the following approaches and methods in this handbook: systems scoping (Chapter 5), participatory data collection (Chapter 8), facilitated dialogues (Chapter 9), futures analysis (Chapter 10), qualitative content analysis (Chapter 19), comparative case study analysis (Chapter 20), institutional analysis (Chapter 22), network analysis (Chapter 23), spatial mapping and analysis (Chapter 24), historical assessment (Chapter 25), and livelihood and vulnerability analysis (Chapter 32).
- Full Text:
- Date Issued: 2021
Knowledge of formal and informal regulations affecting wild plant foraging practices in urban spaces in South Africa
- Garekae, Hesekia, Shackleton, Charlie M
- Authors: Garekae, Hesekia , Shackleton, Charlie M
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/403221 , vital:69935 , xlink:href="https://doi.org/10.1016/j.forpol.2021.102659"
- Description: Although foraging wild plants is commonly perceived to be synonymous with rural areas, it is now increasingly recognized in urban areas. Notwithstanding, the regulations conditioning access to and rights to foraging in urban green spaces have seldom been examined. This study explored the formal and informal regulations governing access to and defining rights to forageable plant resources in the towns of Potchefstroom and Thabazimbi, South Africa. A random sample of 374 households was considered for the survey, complemented by in-depth interviews with 26 participants. Foraging occurred in a variety of public and private spaces, with the frequency of access differing with the type of space. The majority of the respondents were unaware of formal and informal regulations governing access to and use of urban landscapes. Recognizing foraging activities in urban landscapes is a fundamental step toward fostering active community involvement in the management and production of urban green spaces.
- Full Text:
- Date Issued: 2021
- Authors: Garekae, Hesekia , Shackleton, Charlie M
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/403221 , vital:69935 , xlink:href="https://doi.org/10.1016/j.forpol.2021.102659"
- Description: Although foraging wild plants is commonly perceived to be synonymous with rural areas, it is now increasingly recognized in urban areas. Notwithstanding, the regulations conditioning access to and rights to foraging in urban green spaces have seldom been examined. This study explored the formal and informal regulations governing access to and defining rights to forageable plant resources in the towns of Potchefstroom and Thabazimbi, South Africa. A random sample of 374 households was considered for the survey, complemented by in-depth interviews with 26 participants. Foraging occurred in a variety of public and private spaces, with the frequency of access differing with the type of space. The majority of the respondents were unaware of formal and informal regulations governing access to and use of urban landscapes. Recognizing foraging activities in urban landscapes is a fundamental step toward fostering active community involvement in the management and production of urban green spaces.
- Full Text:
- Date Issued: 2021
Livelihood and vulnerability analysis
- Shackleton, Charlie M, Schreckenberg, Kate, Shackleton, Sheona E, Luckert, Marty
- Authors: Shackleton, Charlie M , Schreckenberg, Kate , Shackleton, Sheona E , Luckert, Marty
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433811 , vital:73002 , ISBN 9781000401516 , https://library.oapen.org/handle/20.500.12657/49560
- Description: Livelihood analysis and vulnerability analysis are integrative approaches and consequently draw on a variety of methods to collect and analyse primary and secondary data covered in other chapters. Core ones include systems scoping (Chapter 5), ecological field data collection (Chapter 6), interviews and surveys (Chapter 7), participatory data collection (Chapter 8), action research (Chapter 15), statistical analysis (Chapter 18), qualitative content analysis (Chapter 19), comparative case study analysis (Chapter 20), institutional analysis (Chapter 22) and spatial mapping and analysis (Chapter 24).
- Full Text:
- Date Issued: 2021
- Authors: Shackleton, Charlie M , Schreckenberg, Kate , Shackleton, Sheona E , Luckert, Marty
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433811 , vital:73002 , ISBN 9781000401516 , https://library.oapen.org/handle/20.500.12657/49560
- Description: Livelihood analysis and vulnerability analysis are integrative approaches and consequently draw on a variety of methods to collect and analyse primary and secondary data covered in other chapters. Core ones include systems scoping (Chapter 5), ecological field data collection (Chapter 6), interviews and surveys (Chapter 7), participatory data collection (Chapter 8), action research (Chapter 15), statistical analysis (Chapter 18), qualitative content analysis (Chapter 19), comparative case study analysis (Chapter 20), institutional analysis (Chapter 22) and spatial mapping and analysis (Chapter 24).
- Full Text:
- Date Issued: 2021
Participatory data collection
- de Vos, Alta, Preiser, Rika, Masterson, Vanessa A
- Authors: de Vos, Alta , Preiser, Rika , Masterson, Vanessa A
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433842 , vital:73004 , ISBN 9781000401516 , https://library.oapen.org/handle/20.500.12657/49560
- Description: Participatory mapping (direct-to-digital participatory mapping, 3D-participatory mapping, participatory GIS), photovoice, transect walks, ranking exercises, focus group discussions, Venn diagrams, matrix scoring, ecograms, timelines, Q-methodology, community mapping, participatory videography, photo elicitation, seasonal calendars, participatory action research, participatory rural appraisal, participant observation, arts-based methods.
- Full Text:
- Date Issued: 2021
- Authors: de Vos, Alta , Preiser, Rika , Masterson, Vanessa A
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433842 , vital:73004 , ISBN 9781000401516 , https://library.oapen.org/handle/20.500.12657/49560
- Description: Participatory mapping (direct-to-digital participatory mapping, 3D-participatory mapping, participatory GIS), photovoice, transect walks, ranking exercises, focus group discussions, Venn diagrams, matrix scoring, ecograms, timelines, Q-methodology, community mapping, participatory videography, photo elicitation, seasonal calendars, participatory action research, participatory rural appraisal, participant observation, arts-based methods.
- Full Text:
- Date Issued: 2021
Scenario development
- Hichert, Tanya, Biggs, Reinette, de Vos, Alta, Peterson, Garry
- Authors: Hichert, Tanya , Biggs, Reinette , de Vos, Alta , Peterson, Garry
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433857 , vital:73005 , ISBN 9781000401516 , https://library.oapen.org/handle/20.500.12657/49560
- Description: Scenario development connects to various other methods, but in particular to futures analysis (Chapter 10) as it is also regarded as a futures analysis method. It warrants a separate chapter in addition to the other futures analysis methods (described in Chapter 10) because of its importance and widespread use. Scenario development also connects to facilitated dialogues (Chapter 9), serious games (Chapter 12), participatory modelling and planning (Chapter 13), dynamical systems modelling (Chapter 26) and agent-based modelling (Chapter 28).
- Full Text:
- Date Issued: 2021
- Authors: Hichert, Tanya , Biggs, Reinette , de Vos, Alta , Peterson, Garry
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433857 , vital:73005 , ISBN 9781000401516 , https://library.oapen.org/handle/20.500.12657/49560
- Description: Scenario development connects to various other methods, but in particular to futures analysis (Chapter 10) as it is also regarded as a futures analysis method. It warrants a separate chapter in addition to the other futures analysis methods (described in Chapter 10) because of its importance and widespread use. Scenario development also connects to facilitated dialogues (Chapter 9), serious games (Chapter 12), participatory modelling and planning (Chapter 13), dynamical systems modelling (Chapter 26) and agent-based modelling (Chapter 28).
- Full Text:
- Date Issued: 2021
Segmentation of Tuta Absoluta’s Damage on Tomato Plants: A Computer Vision Approach
- Loyani, Loyani K, Bradshaw, Karen L, Machuze, Dina
- Authors: Loyani, Loyani K , Bradshaw, Karen L , Machuze, Dina
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440313 , vital:73765 , xlink:href="https://doi.org/10.1080/08839514.2021.1972254"
- Description: Tuta absoluta is a major threat to tomato production, causing losses ranging from 80% to 100% when not properly managed. Early detection of T. absoluta’s effects on tomato plants is important in controlling and preventing severe pest damage on tomatoes. In this study, we propose semantic and instance segmentation models based on U-Net and Mask RCNN, deep Convolutional Neural Networks (CNN) to segment the effects of T. absoluta on tomato leaf images at pixel level using field data. The results show that Mask RCNN achieved a mean Average Precision of 85.67%, while the U-Net model achieved an Intersection over Union of 78.60% and Dice coefficient of 82.86%. Both models can precisely generate segmentations indicating the exact spots/areas infested by T. absoluta in tomato leaves. The model will help farmers and extension officers make informed decisions to improve tomato productivity and rescue farmers from annual losses.
- Full Text:
- Date Issued: 2021
- Authors: Loyani, Loyani K , Bradshaw, Karen L , Machuze, Dina
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440313 , vital:73765 , xlink:href="https://doi.org/10.1080/08839514.2021.1972254"
- Description: Tuta absoluta is a major threat to tomato production, causing losses ranging from 80% to 100% when not properly managed. Early detection of T. absoluta’s effects on tomato plants is important in controlling and preventing severe pest damage on tomatoes. In this study, we propose semantic and instance segmentation models based on U-Net and Mask RCNN, deep Convolutional Neural Networks (CNN) to segment the effects of T. absoluta on tomato leaf images at pixel level using field data. The results show that Mask RCNN achieved a mean Average Precision of 85.67%, while the U-Net model achieved an Intersection over Union of 78.60% and Dice coefficient of 82.86%. Both models can precisely generate segmentations indicating the exact spots/areas infested by T. absoluta in tomato leaves. The model will help farmers and extension officers make informed decisions to improve tomato productivity and rescue farmers from annual losses.
- Full Text:
- Date Issued: 2021
Synthesis and emerging frontiers in social-ecological systems research methods
- Schluter, Maja, Biggs, Reinette, Clements, Hayley, de Vos, Alta, Maciejewski, Kristine, Preiser, Rika
- Authors: Schluter, Maja , Biggs, Reinette , Clements, Hayley , de Vos, Alta , Maciejewski, Kristine , Preiser, Rika
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433887 , vital:73007 , ISBN 9781000401516 , https://library.oapen.org/handle/20.500.12657/49560
- Description: Social-ecological systems (SES) research is a rapidly emerging new research domain within the broader emerging area of sustainability science. It is largely a problem-driven and action-oriented field, motivated by the immense sustainability and equity-related challenges facing society (see Chapter 1). Social-ecological systems research is based on an understanding that SES are complex adaptive systems (CAS), where social and ecological dynamics are deeply intertwined, and give rise to features and problems that cannot be understood or addressed by studying these dimensions in isolation (see Chapter 2). The field draws on and combines methods from both natural and social sciences, and combines quantitative and qualitative approaches. As such, SES research is characterised by epistemological and methodological pluralism, which is challenging for those entering the field and has complex implications for the research process, methods and ethical considerations to be taken into account in SES research (see Chapter 3). This book aims to clarify and synthesise this plurality by providing an introduction to SES research (Part 1), and the diversity of methods currently used in the field (Part 2). The aim of this final chapter (Part 3) is to provide a synthesis of the current landscape of SES methods, critically reflect on the methods with respect to their ability to address systemic features of SES and discuss some of the most common methodological challenges associated with the complex adaptive and intertwined nature of SES. Based on this synthesis, we identify methodological gaps and discuss novel methods and method combinations that may help to address these gaps and move the field forward.
- Full Text:
- Date Issued: 2021
- Authors: Schluter, Maja , Biggs, Reinette , Clements, Hayley , de Vos, Alta , Maciejewski, Kristine , Preiser, Rika
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433887 , vital:73007 , ISBN 9781000401516 , https://library.oapen.org/handle/20.500.12657/49560
- Description: Social-ecological systems (SES) research is a rapidly emerging new research domain within the broader emerging area of sustainability science. It is largely a problem-driven and action-oriented field, motivated by the immense sustainability and equity-related challenges facing society (see Chapter 1). Social-ecological systems research is based on an understanding that SES are complex adaptive systems (CAS), where social and ecological dynamics are deeply intertwined, and give rise to features and problems that cannot be understood or addressed by studying these dimensions in isolation (see Chapter 2). The field draws on and combines methods from both natural and social sciences, and combines quantitative and qualitative approaches. As such, SES research is characterised by epistemological and methodological pluralism, which is challenging for those entering the field and has complex implications for the research process, methods and ethical considerations to be taken into account in SES research (see Chapter 3). This book aims to clarify and synthesise this plurality by providing an introduction to SES research (Part 1), and the diversity of methods currently used in the field (Part 2). The aim of this final chapter (Part 3) is to provide a synthesis of the current landscape of SES methods, critically reflect on the methods with respect to their ability to address systemic features of SES and discuss some of the most common methodological challenges associated with the complex adaptive and intertwined nature of SES. Based on this synthesis, we identify methodological gaps and discuss novel methods and method combinations that may help to address these gaps and move the field forward.
- Full Text:
- Date Issued: 2021
The cultural significance of plant-fiber crafts in Southern Africa: a comparative study of Eswatini, Malawi, and Zimbabwe
- Pullanikkatil, Deepa, Thondhlana, Gladman, Shackleton, Charlie M
- Authors: Pullanikkatil, Deepa , Thondhlana, Gladman , Shackleton, Charlie M
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/399860 , vital:69564 , xlink:href="https://doi.org/10.1080/14728028.2021.1998797"
- Description: Traditional handicrafts made from various plant materials are produced by most cultures around the world. Many originated through symbolic and utilitarian needs that became ritualized through time, thereby gradually attaining greater value as cultural items or symbols rather than solely functional ones. Here we report on a survey of 343 crafters across Eswatini, Malawi, and Zimbabwe in southern Africa regarding the cultural uses and significance of the items they make from wild plant fibers and sell to local communities or tourists. The plant materials used were largely dictated by tradition and local availability and were crafted into a diverse range of products including baskets, mats, brooms, storage containers, hats, fish traps, ornaments, and furniture. Many products had uses and cultural significance at major ceremonies or rituals, such as weddings, funerals, initiation, and divination. The preparation and design of the different crafts were influenced by tradition as well as market demand as indicated by tourist fashions and advice provided by government or non-government agencies to boost income generation from crafts. Although the crafting of cultural objects is increasingly commercialized and subject to the tastes and fashions of tourist markets in the region, the traditional and cultural significance of such artifacts remains widely recognized and valued.
- Full Text:
- Date Issued: 2021
- Authors: Pullanikkatil, Deepa , Thondhlana, Gladman , Shackleton, Charlie M
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/399860 , vital:69564 , xlink:href="https://doi.org/10.1080/14728028.2021.1998797"
- Description: Traditional handicrafts made from various plant materials are produced by most cultures around the world. Many originated through symbolic and utilitarian needs that became ritualized through time, thereby gradually attaining greater value as cultural items or symbols rather than solely functional ones. Here we report on a survey of 343 crafters across Eswatini, Malawi, and Zimbabwe in southern Africa regarding the cultural uses and significance of the items they make from wild plant fibers and sell to local communities or tourists. The plant materials used were largely dictated by tradition and local availability and were crafted into a diverse range of products including baskets, mats, brooms, storage containers, hats, fish traps, ornaments, and furniture. Many products had uses and cultural significance at major ceremonies or rituals, such as weddings, funerals, initiation, and divination. The preparation and design of the different crafts were influenced by tradition as well as market demand as indicated by tourist fashions and advice provided by government or non-government agencies to boost income generation from crafts. Although the crafting of cultural objects is increasingly commercialized and subject to the tastes and fashions of tourist markets in the region, the traditional and cultural significance of such artifacts remains widely recognized and valued.
- Full Text:
- Date Issued: 2021
The practice and design of social-ecological systems research
- de Vos, Alta, Maciejewski, Kristine, Bodin, Orjan, Norstrom, Albert, Schluter, Maja, Tengo, Maria
- Authors: de Vos, Alta , Maciejewski, Kristine , Bodin, Orjan , Norstrom, Albert , Schluter, Maja , Tengo, Maria
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433826 , vital:73003 , ISBN 9781000401516 , https://library.oapen.org/handle/20.500.12657/49560
- Description: Studying social-ecological systems (SES) can be a challenging task, as explained in Chapter 2. Phenomena of interest and characteristics of SES research result from both social and ecological processes, and complicated feedback dynamics blur the distinction between cause and effect (Young et al. 2006). Furthermore, multiple causal processes may be operating simultaneously, outcomes are strongly influenced by the system’s context and it is difficult to determine system boundaries (Bodin and Prell 2011).
- Full Text:
- Date Issued: 2021
- Authors: de Vos, Alta , Maciejewski, Kristine , Bodin, Orjan , Norstrom, Albert , Schluter, Maja , Tengo, Maria
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433826 , vital:73003 , ISBN 9781000401516 , https://library.oapen.org/handle/20.500.12657/49560
- Description: Studying social-ecological systems (SES) can be a challenging task, as explained in Chapter 2. Phenomena of interest and characteristics of SES research result from both social and ecological processes, and complicated feedback dynamics blur the distinction between cause and effect (Young et al. 2006). Furthermore, multiple causal processes may be operating simultaneously, outcomes are strongly influenced by the system’s context and it is difficult to determine system boundaries (Bodin and Prell 2011).
- Full Text:
- Date Issued: 2021
What are social-ecological systems and social-ecological systems research
- Biggs, Reinette, Clements, Hayley, de Vos, Alta, Folke, Carl, Manyani, Amanda, Maciejewski, Kristine, Martin-Lopez, Berta, Preiser, Rika, Selomane, Odirilwe, Schluter, Maja
- Authors: Biggs, Reinette , Clements, Hayley , de Vos, Alta , Folke, Carl , Manyani, Amanda , Maciejewski, Kristine , Martin-Lopez, Berta , Preiser, Rika , Selomane, Odirilwe , Schluter, Maja
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433900 , vital:73008 , ISBN 9781000401516 , https://library.oapen.org/handle/20.500.12657/49560
- Description: The period since the Second World War has been marked by rapid and accelerating changes to many aspects of human society and the environment (Clark, Crutzen, and Schellnhuber 2004; Steffen et al. 2011; Steffen et al. 2015a). There is accumulating evidence and rising concern about the potential consequences these changes hold for key Earth system processes at a global scale, and human well-being and prosperity into the future (Krausmann et al. 2013; Steffen et al. 2015b). The Anthropocene, as this new era of extensive human impact on the Earth has come to be known (Crutzen 2006), manifests in a closely intertwined set of social and ecological changes. Technological advances, increasing human population, rising levels of wealth and consumption, and the institutional arrangements we have developed to govern our economies and societies interplay with one another, and drastically affect the Earth’s climate, biological diversity, fresh-water and biogeochemical flows, and levels of novel pollutants in the environment (Steffen et al. 2015a). These environmental changes, in turn, contribute to increasingly frequent and severe droughts (Dai 2013; Trenberth et al. 2014), floods (Milly et al. 2002; Nicholls 2004), heatwaves (Guo et al. 2018; Oliver et al. 2018) and the emergence of novel pathogens such as SARS-CoV-2 (Everard et al. 2020; O ’Callaghan-Gordo and Antò 2020; Schmeller, Courchamp, and Killeen 2020) that can lead to massive societal disruption and hardship, especially among the poor (Wheeler and Von Braun 2013; Barbier and Hochard 2018).
- Full Text:
- Date Issued: 2021
- Authors: Biggs, Reinette , Clements, Hayley , de Vos, Alta , Folke, Carl , Manyani, Amanda , Maciejewski, Kristine , Martin-Lopez, Berta , Preiser, Rika , Selomane, Odirilwe , Schluter, Maja
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433900 , vital:73008 , ISBN 9781000401516 , https://library.oapen.org/handle/20.500.12657/49560
- Description: The period since the Second World War has been marked by rapid and accelerating changes to many aspects of human society and the environment (Clark, Crutzen, and Schellnhuber 2004; Steffen et al. 2011; Steffen et al. 2015a). There is accumulating evidence and rising concern about the potential consequences these changes hold for key Earth system processes at a global scale, and human well-being and prosperity into the future (Krausmann et al. 2013; Steffen et al. 2015b). The Anthropocene, as this new era of extensive human impact on the Earth has come to be known (Crutzen 2006), manifests in a closely intertwined set of social and ecological changes. Technological advances, increasing human population, rising levels of wealth and consumption, and the institutional arrangements we have developed to govern our economies and societies interplay with one another, and drastically affect the Earth’s climate, biological diversity, fresh-water and biogeochemical flows, and levels of novel pollutants in the environment (Steffen et al. 2015a). These environmental changes, in turn, contribute to increasingly frequent and severe droughts (Dai 2013; Trenberth et al. 2014), floods (Milly et al. 2002; Nicholls 2004), heatwaves (Guo et al. 2018; Oliver et al. 2018) and the emergence of novel pathogens such as SARS-CoV-2 (Everard et al. 2020; O ’Callaghan-Gordo and Antò 2020; Schmeller, Courchamp, and Killeen 2020) that can lead to massive societal disruption and hardship, especially among the poor (Wheeler and Von Braun 2013; Barbier and Hochard 2018).
- Full Text:
- Date Issued: 2021
A new indole alkaloid and other constituents from Monodora minor and Uvaria tanzaniae: their antitrypanosomal and antiplasmodial evaluation
- Christopher, Robert, Mgani, Quintino A, Nyandoro, Stephen S, Rousseau, Amanda L, Isaacs, Michelle, Hoppe, Heinrich C
- Authors: Christopher, Robert , Mgani, Quintino A , Nyandoro, Stephen S , Rousseau, Amanda L , Isaacs, Michelle , Hoppe, Heinrich C
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429347 , vital:72603 , xlink:href="https://doi.org/10.1080/14786419.2019.1710705"
- Description: Phytochemical investigation of the methanolic extract of Monodora minor Engl. and Diels (Annonaceae) stem bark yielded a new indole (E)-4-(1H-indol-5-yl)-but-3-en-2-one (1), a known indole 5-formyl-1H-indole (2) and an ubiquitous steroid sitosterol (3). The investigations of the methanolic extract of Uvaria tanzaniae Verdc. (Annonaceae) root bark yielded two previously reported C-benzylated dihydrochalcones namely uvaretin (4) and diuvaretin (5). Structures of the isolated compounds were elucidated based on NMR spectroscopy and high resolution electron ionization mass spectrometry (HR-EI-MS) data. All compounds were tested against Trypanosoma brucei brucei and Plasmodium falciparum. At a single concentration (20 μM) in the antitrypanosomal and antiplasmodial assays, compound 4 exhibited remarkable activities against T. brucei brucei and P. falciparum with percentage inhibition of 97.3% and 83.0% respectively, whereas compounds 1, 2, 3 and 5 were inactive. In a dose response antiplasmodial assay compound 4 exhibited moderate activity against P. falciparum with an IC50 value of 7.20 μM.
- Full Text:
- Date Issued: 2020
- Authors: Christopher, Robert , Mgani, Quintino A , Nyandoro, Stephen S , Rousseau, Amanda L , Isaacs, Michelle , Hoppe, Heinrich C
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429347 , vital:72603 , xlink:href="https://doi.org/10.1080/14786419.2019.1710705"
- Description: Phytochemical investigation of the methanolic extract of Monodora minor Engl. and Diels (Annonaceae) stem bark yielded a new indole (E)-4-(1H-indol-5-yl)-but-3-en-2-one (1), a known indole 5-formyl-1H-indole (2) and an ubiquitous steroid sitosterol (3). The investigations of the methanolic extract of Uvaria tanzaniae Verdc. (Annonaceae) root bark yielded two previously reported C-benzylated dihydrochalcones namely uvaretin (4) and diuvaretin (5). Structures of the isolated compounds were elucidated based on NMR spectroscopy and high resolution electron ionization mass spectrometry (HR-EI-MS) data. All compounds were tested against Trypanosoma brucei brucei and Plasmodium falciparum. At a single concentration (20 μM) in the antitrypanosomal and antiplasmodial assays, compound 4 exhibited remarkable activities against T. brucei brucei and P. falciparum with percentage inhibition of 97.3% and 83.0% respectively, whereas compounds 1, 2, 3 and 5 were inactive. In a dose response antiplasmodial assay compound 4 exhibited moderate activity against P. falciparum with an IC50 value of 7.20 μM.
- Full Text:
- Date Issued: 2020
AMBER force field parameters for the Zn (II) ions of the tunneling-fold enzymes GTP cyclohydrolase I and 6-pyruvoyl tetrahydropterin synthase
- Khairallah, Afrah, Tastan Bishop, Ozlem, Moses, Vuyani
- Authors: Khairallah, Afrah , Tastan Bishop, Ozlem , Moses, Vuyani
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429360 , vital:72604 , xlink:href="https://doi.org/10.1080/07391102.2020.1796800"
- Description: The folate biosynthesis pathway is an essential pathway for cell growth and survival. Folate derivatives serve as a source of the one-carbon units in several intracellular metabolic reactions. Rapidly dividing cells rely heavily on the availability of folate derivatives for their proliferation. As a result, drugs targeting this pathway have shown to be effective against tumor cells and pathogens, but drug resistance against the available antifolate drugs emerged quickly. Therefore, there is a need to develop new treatment strategies and identify alternative metabolic targets. The two de novo folate biosynthesis pathway enzymes, GTP cyclohydrolase I (GCH1) and 6-pyruvoyl tetrahydropterin synthase (PTPS), can provide an alternative strategy to overcome the drug resistance that emerged in the two primary targeted enzymes dihydrofolate reductase and dihydropteroate synthase. Both GCH1 and PTPS enzymes contain Zn2+ ions in their active sites, and to accurately study their dynamic behaviors using all-atom molecular dynamics (MD) simulations, appropriate parameters that can describe their metal sites should be developed and validated. In this study, force field parameters of the GCH1 and PTPS metal centers were generated using quantum mechanics (QM) calculations and then validated through MD simulations to ensure their accuracy in describing and maintaining the Zn2+ ion coordination environment. The derived force field parameters will provide accurate and reliable MD simulations involving these two enzymes for future in-silico identification of drug candidates against the GCH1 and PTPS enzymes.
- Full Text:
- Date Issued: 2020
- Authors: Khairallah, Afrah , Tastan Bishop, Ozlem , Moses, Vuyani
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429360 , vital:72604 , xlink:href="https://doi.org/10.1080/07391102.2020.1796800"
- Description: The folate biosynthesis pathway is an essential pathway for cell growth and survival. Folate derivatives serve as a source of the one-carbon units in several intracellular metabolic reactions. Rapidly dividing cells rely heavily on the availability of folate derivatives for their proliferation. As a result, drugs targeting this pathway have shown to be effective against tumor cells and pathogens, but drug resistance against the available antifolate drugs emerged quickly. Therefore, there is a need to develop new treatment strategies and identify alternative metabolic targets. The two de novo folate biosynthesis pathway enzymes, GTP cyclohydrolase I (GCH1) and 6-pyruvoyl tetrahydropterin synthase (PTPS), can provide an alternative strategy to overcome the drug resistance that emerged in the two primary targeted enzymes dihydrofolate reductase and dihydropteroate synthase. Both GCH1 and PTPS enzymes contain Zn2+ ions in their active sites, and to accurately study their dynamic behaviors using all-atom molecular dynamics (MD) simulations, appropriate parameters that can describe their metal sites should be developed and validated. In this study, force field parameters of the GCH1 and PTPS metal centers were generated using quantum mechanics (QM) calculations and then validated through MD simulations to ensure their accuracy in describing and maintaining the Zn2+ ion coordination environment. The derived force field parameters will provide accurate and reliable MD simulations involving these two enzymes for future in-silico identification of drug candidates against the GCH1 and PTPS enzymes.
- Full Text:
- Date Issued: 2020