Knowledge and knowledge sources on the importance of fruits for nutritional security are unaffected by deforestation status in Cameroon
- Ijang, T N P, Shackleton, Charlie M, Degrande, A
- Authors: Ijang, T N P , Shackleton, Charlie M , Degrande, A
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/177454 , vital:42823 , DOI: 10.17660/th2019/74.6.2
- Description: The Congo basin forest is experiencing increasing rate of deforestation, and is prone to inconsistent food supply and sporadic food shortages with corresponding high levels of malnutrition. Maintenance or planting of fruit trees can help mitigate deforestation while supplying fruits for home consumption. However, data on rates of fruit consumption are lacking for many developing countries, including Cameroon.
- Full Text:
- Authors: Ijang, T N P , Shackleton, Charlie M , Degrande, A
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/177454 , vital:42823 , DOI: 10.17660/th2019/74.6.2
- Description: The Congo basin forest is experiencing increasing rate of deforestation, and is prone to inconsistent food supply and sporadic food shortages with corresponding high levels of malnutrition. Maintenance or planting of fruit trees can help mitigate deforestation while supplying fruits for home consumption. However, data on rates of fruit consumption are lacking for many developing countries, including Cameroon.
- Full Text:
Labour market perceptions of students at a Technical and Vocational Education and Training (TVET) college in Grahamstown, South Africa
- Authors: Khambule, Nelisa
- Date: 2019
- Subjects: Eastcape Midlands College (Makhanda, South Africa) -- Students -- Attitudes , College students -- South Africa -- Makhanda -- Attitudes , College graduates -- Employment -- South Africa , Labor market -- South Africa , Employability -- South Africa
- Language: English
- Type: text , Thesis , Masters , MSocSc
- Identifier: http://hdl.handle.net/10962/96515 , vital:31289
- Description: In the context of South Africa, the supply of intermediate to high-level skills is central to economic growth and development. The post-school education and training sector is a critical source of these skills. Technical and Vocational Education and Training (TVET) colleges are expected to provide the intermediate to high-level skills that are required in a fast-changing global and national economy. In addition to fulfilling the goal of meeting the skills needs of the country, TVET colleges are expected to expand access to education and training opportunities and create pathways that will ensure smooth transitions for learners from college to employment. Using the third-generation labour market segmentation approach to the study of labour markets, this study sought to investigate the various socio-political factors that influence TVET college students’ perceptions about employment opportunities in the labour market with a NCV qualification. Using a qualitative methodology, this research investigated whether TVET students at Eastcape Midlands College felt adequately prepared for the labour market with their prospective post-secondary school qualification. The findings varied, with some students being of the view that the theoretical component of their programme of study could be improved to better prepare them for the labour market, and others, being of the view that the practical component could be improved. At a general level, the findings showed that the students did not have perfect knowledge of the availability of employment opportunities for their prospective qualifications.
- Full Text:
- Authors: Khambule, Nelisa
- Date: 2019
- Subjects: Eastcape Midlands College (Makhanda, South Africa) -- Students -- Attitudes , College students -- South Africa -- Makhanda -- Attitudes , College graduates -- Employment -- South Africa , Labor market -- South Africa , Employability -- South Africa
- Language: English
- Type: text , Thesis , Masters , MSocSc
- Identifier: http://hdl.handle.net/10962/96515 , vital:31289
- Description: In the context of South Africa, the supply of intermediate to high-level skills is central to economic growth and development. The post-school education and training sector is a critical source of these skills. Technical and Vocational Education and Training (TVET) colleges are expected to provide the intermediate to high-level skills that are required in a fast-changing global and national economy. In addition to fulfilling the goal of meeting the skills needs of the country, TVET colleges are expected to expand access to education and training opportunities and create pathways that will ensure smooth transitions for learners from college to employment. Using the third-generation labour market segmentation approach to the study of labour markets, this study sought to investigate the various socio-political factors that influence TVET college students’ perceptions about employment opportunities in the labour market with a NCV qualification. Using a qualitative methodology, this research investigated whether TVET students at Eastcape Midlands College felt adequately prepared for the labour market with their prospective post-secondary school qualification. The findings varied, with some students being of the view that the theoretical component of their programme of study could be improved to better prepare them for the labour market, and others, being of the view that the practical component could be improved. At a general level, the findings showed that the students did not have perfect knowledge of the availability of employment opportunities for their prospective qualifications.
- Full Text:
Landscape, memory and learning to change in changing worlds: Contemplating intergenerational learning and traditional knowledge practices within social-ecological landscapes of change
- O'Donoghue, Rob B, Sandoval-Rivera, Juan Carlos, Payyappallimana, Unnikrishnan
- Authors: O'Donoghue, Rob B , Sandoval-Rivera, Juan Carlos , Payyappallimana, Unnikrishnan
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/388061 , vital:68304 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/187218"
- Description: The core paper and collection of short papers from Mexico, Africa, India and Sweden that make up this study on social-ecological landscapes developed as a South–South collaboration that was extended to include a case in the North. Our concern was to explore how situated, intergenerational knowledge commonly takes a back seat to the conceptual propositions that the environmental sciences have developed around matters of concern like biodiversity loss. In this way, scientific propositions have become the conceptual capital for informing future sustainability through Education for Sustainable Development (ESD). In response to this, a more situated turn has developed to engage both intergenerational practices and the institutional sciences, but the playing fields are seldom level and deliberations are often rife with misunderstandings.
- Full Text:
- Authors: O'Donoghue, Rob B , Sandoval-Rivera, Juan Carlos , Payyappallimana, Unnikrishnan
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/388061 , vital:68304 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/187218"
- Description: The core paper and collection of short papers from Mexico, Africa, India and Sweden that make up this study on social-ecological landscapes developed as a South–South collaboration that was extended to include a case in the North. Our concern was to explore how situated, intergenerational knowledge commonly takes a back seat to the conceptual propositions that the environmental sciences have developed around matters of concern like biodiversity loss. In this way, scientific propositions have become the conceptual capital for informing future sustainability through Education for Sustainable Development (ESD). In response to this, a more situated turn has developed to engage both intergenerational practices and the institutional sciences, but the playing fields are seldom level and deliberations are often rife with misunderstandings.
- Full Text:
Language policy and linguistic landscapes at schools in South Africa:
- Kaschula, Russell H, Kretzer, Michael M
- Authors: Kaschula, Russell H , Kretzer, Michael M
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/174635 , vital:42496 , https://doi.org/10.1080/14790718.2019.1666849
- Description: Language policy and Linguistic Landscapes (LL) are a highly contested area in South Africa. Due to Apartheid, the education system constitutes the core of such contestation. In Post-Apartheid South Africa the new Constitution of 1996, the South African Schools Act (SASA) and recent political initiatives such as the Use of Official Languages Act of 2012 form the foundation of language policy at schools. The Constitution declares 11 official languages on a macro-level. Nevertheless, English dominates the LL in South Africa. African Languages are significantly underrepresented in the public sphere. The vast majority of research emphasises the urban or semi-urban areas. This research tries to close the existing research gap with a broad comparative study in three research provinces.
- Full Text:
- Authors: Kaschula, Russell H , Kretzer, Michael M
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/174635 , vital:42496 , https://doi.org/10.1080/14790718.2019.1666849
- Description: Language policy and Linguistic Landscapes (LL) are a highly contested area in South Africa. Due to Apartheid, the education system constitutes the core of such contestation. In Post-Apartheid South Africa the new Constitution of 1996, the South African Schools Act (SASA) and recent political initiatives such as the Use of Official Languages Act of 2012 form the foundation of language policy at schools. The Constitution declares 11 official languages on a macro-level. Nevertheless, English dominates the LL in South Africa. African Languages are significantly underrepresented in the public sphere. The vast majority of research emphasises the urban or semi-urban areas. This research tries to close the existing research gap with a broad comparative study in three research provinces.
- Full Text:
Language-in-education policy and language practices in Botswana primary schools: a case study of 3 schools
- Authors: Tselayakhumo, Dumelang
- Date: 2019
- Subjects: Translanguaging (Linguistics) , Multilingual education -- Botswana , Home and school -- Botswana , Language in contact -- Botswana , Language and education -- Case studies -- Botswana , Language policy -- Botswana
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/68271 , vital:29226
- Description: This is a multiple case study of language practices in relation to the language-in-education policy of Botswana. The impetus for this study came after realising a decline in the academic achievement of learners as they move to higher levels of education. Taking into cognisance other factors like socio-economic background and marginalised communities, this study intended to investigate language practices at 3 primary schools at Standard 1, Standard 4 and Standard 7. Cases were selected from 3 various schools in different districts that present the language situation in Botswana. School A was in Kgalagadi district where the dominant spoken language is Shekgalagarhi, a minority language of Botswana. School B was in Southern district where the dominant spoken language is Setswana, the national language of Botswana and School C was in Gaborone city, the capital city of Botswana, where languages of Botswana come into contact and parents mainly use English to communicate with their children at home. Observation of language practices at these schools was the primary technique of data collection. The researcher also used questionnaires and focus group discussions for authentication. It was realised that whereas the language-in-education policy of Botswana is monoglossic, as it separates languages into separate functions, language practices in the three primary schools were transglossic, as they involved the use of different language varieties in the classroom. However, the researcher discovered that there was limited translanguaging that limited learner creativity and participation in class. The language practices revealed compliance and non-compliance of some schools to the national language-in-education policy. The researcher found language teaching to be one of the factors that limited content acquisition in content subject lessons. Realising the irrelevance of the policy to the linguistic needs of learners, this study proposes guidelines on the implementation of a multilingual micro policy that considers both the strong and the weak versions of translanguaging. This will open ways for translanguaging henceforth, active participation and enhanced performance for all Batswana. It also proposes the study of 3 languages: a minority language of Botswana, Setswana and English as compulsory subjects to embrace multilingualism and for the development of indigenous languages.
- Full Text:
- Authors: Tselayakhumo, Dumelang
- Date: 2019
- Subjects: Translanguaging (Linguistics) , Multilingual education -- Botswana , Home and school -- Botswana , Language in contact -- Botswana , Language and education -- Case studies -- Botswana , Language policy -- Botswana
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/68271 , vital:29226
- Description: This is a multiple case study of language practices in relation to the language-in-education policy of Botswana. The impetus for this study came after realising a decline in the academic achievement of learners as they move to higher levels of education. Taking into cognisance other factors like socio-economic background and marginalised communities, this study intended to investigate language practices at 3 primary schools at Standard 1, Standard 4 and Standard 7. Cases were selected from 3 various schools in different districts that present the language situation in Botswana. School A was in Kgalagadi district where the dominant spoken language is Shekgalagarhi, a minority language of Botswana. School B was in Southern district where the dominant spoken language is Setswana, the national language of Botswana and School C was in Gaborone city, the capital city of Botswana, where languages of Botswana come into contact and parents mainly use English to communicate with their children at home. Observation of language practices at these schools was the primary technique of data collection. The researcher also used questionnaires and focus group discussions for authentication. It was realised that whereas the language-in-education policy of Botswana is monoglossic, as it separates languages into separate functions, language practices in the three primary schools were transglossic, as they involved the use of different language varieties in the classroom. However, the researcher discovered that there was limited translanguaging that limited learner creativity and participation in class. The language practices revealed compliance and non-compliance of some schools to the national language-in-education policy. The researcher found language teaching to be one of the factors that limited content acquisition in content subject lessons. Realising the irrelevance of the policy to the linguistic needs of learners, this study proposes guidelines on the implementation of a multilingual micro policy that considers both the strong and the weak versions of translanguaging. This will open ways for translanguaging henceforth, active participation and enhanced performance for all Batswana. It also proposes the study of 3 languages: a minority language of Botswana, Setswana and English as compulsory subjects to embrace multilingualism and for the development of indigenous languages.
- Full Text:
Large scale spatio-temporal forcing of pelagic-coastal coupling: disentangling the effects of environmental change on intertidal invertebrate recruitment
- Authors: Muñiz, Carlota Fernández
- Date: 2019
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/75317 , vital:30400
- Description: Marine systems are driven by the relationships among organisms and environmental conditions. Anthropogenic-induced changes during the past decades have started to alter climatic drivers which have the potential to alter the physical, chemical and biological environment. In coastal systems, biogeography is influenced by the temporal variability in the conditions of the water mass. In addition, many marine benthic organisms develop in the water mass and rely on the conditions that link the pelagic and benthic systems for population maintenance. Such pelagic-coastal coupling indicates that changes in the trophic system during development can be transferred to the adult populations through changes in propagule supply. Thus, changes in environmental conditions can influence benthic populations directly (e.g. through larval advection) or indirectly, through their influence on the phytoplankton community (e.g. through the development of HABs). The South African coastline shows clear alongshore patterns of faunal biomass and species richness. On the south coast, strong longitudinal patterns of recruitment of intertidal organisms exist, with areas of particularly high recruitment. HABs of unprecedented spatio-temporal magnitude have recently developed along the south coast, including the areas where benthic recruitment is most intense. The present thesis used these blooms to study changes in intertidal recruitment directly or indirectly associated with their occurrence. Using a combination of remote sensing data to study the environmental conditions of the water mass in the innermost part of the Agulhas Bank, and estimates of mussel and barnacle recruitment rates to integrate the effects of conditions in the water mass during larval development, this thesis aimed to: (1) understand the conditions that triggered the development of an HAB of the dinoflagellate Lingulodinium polyedrum during summer of 2014, (2) determine the direct or indirect effects of that bloom on recruitment of intertidal organisms, and understand the factors that affect recruitment along the coast, (3) determine if the environmental factors during bloom development produced any carryover effects on recruit growth and mortality, and (4) determine the factors that drive changes in community biomass and composition along the south coast, the long-term trends in those factors, and possible changes experienced in recent years. Water column stability during spring, before the development of the red tide, followed by alternating periods of upwelling and relaxation during summer and autumn, seemed to promote the development and persistence of L. polyedrum. Recruitment of mussels and barnacles was estimated during the reproductive season of mussels in 2014, coinciding with the red tide, and during the following year. Alongshore patterns in recruitment were found, with higher mussel recruitment in the absence of the red tide and the opposite pattern in barnacles. Alongshore patterns in SST and chlorophyll matching those of recruitment were also found, with higher SSTs and lower chlorophyll during the red tide than the following year. Growth and mortality rates in barnacles did not differ between years during the first five months after settlement. This suggests that the factors which produced differences in recruitment between years did not produce carryover effects detectable at the temporal scales studied. Further analysis of 15 years of satellite-derived environmental data showed significant cooling trends potentially driven by a long-term seasonal acceleration of the Agulhas Current in autumn around two upwelling centres on the south coast, coinciding temporally with the reproductive period of mussels and barnacles, and spatially with the areas of highest recruitment. In addition, the comparison of SST and chl-a conditions during the first and the second half of the period of study showed that seasonality of both variables has changed in large areas over the shelf, with increasing importance of shorter-term variability, which would in turn decrease environmental predictability. Thus, the conditions observed during the present study, particularly during 2015, when upwelling seemed to be more intense, may presage the potential effects of identified long-term cooling trends at the upwelling centres. Although the general trend shows cooling around those areas, conditions can vary greatly among years, favouring different taxa. Changes in the Agulhas Current System are affected by changes in distant areas in the Indian Ocean basin. Such tele-connection is unlikely to be unique to this system and indicates the importance of understanding trends in major large scale climatic drivers and their regional effects in order to make predictions about coastal systems.
- Full Text:
- Authors: Muñiz, Carlota Fernández
- Date: 2019
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/75317 , vital:30400
- Description: Marine systems are driven by the relationships among organisms and environmental conditions. Anthropogenic-induced changes during the past decades have started to alter climatic drivers which have the potential to alter the physical, chemical and biological environment. In coastal systems, biogeography is influenced by the temporal variability in the conditions of the water mass. In addition, many marine benthic organisms develop in the water mass and rely on the conditions that link the pelagic and benthic systems for population maintenance. Such pelagic-coastal coupling indicates that changes in the trophic system during development can be transferred to the adult populations through changes in propagule supply. Thus, changes in environmental conditions can influence benthic populations directly (e.g. through larval advection) or indirectly, through their influence on the phytoplankton community (e.g. through the development of HABs). The South African coastline shows clear alongshore patterns of faunal biomass and species richness. On the south coast, strong longitudinal patterns of recruitment of intertidal organisms exist, with areas of particularly high recruitment. HABs of unprecedented spatio-temporal magnitude have recently developed along the south coast, including the areas where benthic recruitment is most intense. The present thesis used these blooms to study changes in intertidal recruitment directly or indirectly associated with their occurrence. Using a combination of remote sensing data to study the environmental conditions of the water mass in the innermost part of the Agulhas Bank, and estimates of mussel and barnacle recruitment rates to integrate the effects of conditions in the water mass during larval development, this thesis aimed to: (1) understand the conditions that triggered the development of an HAB of the dinoflagellate Lingulodinium polyedrum during summer of 2014, (2) determine the direct or indirect effects of that bloom on recruitment of intertidal organisms, and understand the factors that affect recruitment along the coast, (3) determine if the environmental factors during bloom development produced any carryover effects on recruit growth and mortality, and (4) determine the factors that drive changes in community biomass and composition along the south coast, the long-term trends in those factors, and possible changes experienced in recent years. Water column stability during spring, before the development of the red tide, followed by alternating periods of upwelling and relaxation during summer and autumn, seemed to promote the development and persistence of L. polyedrum. Recruitment of mussels and barnacles was estimated during the reproductive season of mussels in 2014, coinciding with the red tide, and during the following year. Alongshore patterns in recruitment were found, with higher mussel recruitment in the absence of the red tide and the opposite pattern in barnacles. Alongshore patterns in SST and chlorophyll matching those of recruitment were also found, with higher SSTs and lower chlorophyll during the red tide than the following year. Growth and mortality rates in barnacles did not differ between years during the first five months after settlement. This suggests that the factors which produced differences in recruitment between years did not produce carryover effects detectable at the temporal scales studied. Further analysis of 15 years of satellite-derived environmental data showed significant cooling trends potentially driven by a long-term seasonal acceleration of the Agulhas Current in autumn around two upwelling centres on the south coast, coinciding temporally with the reproductive period of mussels and barnacles, and spatially with the areas of highest recruitment. In addition, the comparison of SST and chl-a conditions during the first and the second half of the period of study showed that seasonality of both variables has changed in large areas over the shelf, with increasing importance of shorter-term variability, which would in turn decrease environmental predictability. Thus, the conditions observed during the present study, particularly during 2015, when upwelling seemed to be more intense, may presage the potential effects of identified long-term cooling trends at the upwelling centres. Although the general trend shows cooling around those areas, conditions can vary greatly among years, favouring different taxa. Changes in the Agulhas Current System are affected by changes in distant areas in the Indian Ocean basin. Such tele-connection is unlikely to be unique to this system and indicates the importance of understanding trends in major large scale climatic drivers and their regional effects in order to make predictions about coastal systems.
- Full Text:
Large scale spatio-temporal forcing of pelagic-coastal coupling: disentangling the effects of environmental change on intertidal invertebrate recruitment
- Authors: Muñiz, Carlota Fernández
- Date: 2019
- Subjects: Dinoflagellates -- South Africa , Coastal ecology -- South Africa , Climatic changes -- South Africa , Benthic ecology -- South Africa , Agulhas Current , Ocean temperature -- Agulhas Current , Ocean temperature -- Physiological effect
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/151541 , vital:39140
- Description: Marine systems are driven by the relationships among organisms and environmental conditions. Anthropogenic-induced changes during the past decades have started to alter climatic drivers which have the potential to alter the physical, chemical and biological environment. In coastal systems, biogeography is influenced by the temporal variability in the conditions of the water mass. In addition, many marine benthic organisms develop in the water mass and rely on the conditions that link the pelagic and benthic systems for population maintenance. Such pelagic-coastal coupling indicates that changes in the trophic system during development can be transferred to the adult populations through changes in propagule supply. Thus, changes in environmental conditions can influence benthic populations directly (e.g. through larval advection) or indirectly, through their influence on the phytoplankton community (e.g. through the development of HABs). The South African coastline shows clear alongshore patterns of faunal biomass and species richness. On the south coast, strong longitudinal patterns of recruitment of intertidal organisms exist, with areas of particularly high recruitment. HABs of unprecedented spatio-temporal magnitude have recently developed along the south coast, including the areas where benthic recruitment is most intense. The present thesis used these blooms to study changes in intertidal recruitment directly or indirectly associated with their occurrence. Using a combination of remote sensing data to study the environmental conditions of the water mass in the innermost part of the Agulhas Bank, and estimates of mussel and barnacle recruitment rates to integrate the effects of conditions in the water mass during larval development, this thesis aimed to: (1) understand the conditions that triggered the development of an HAB of the dinoflagellate Lingulodinium polyedrum during summer of 2014, (2) determine the direct or indirect effects of that bloom on recruitment of intertidal organisms, and understand the factors that affect recruitment along the coast, (3) determine if the environmental factors during bloom development produced any carryover effects on recruit growth and mortality, and (4) determine the factors that drive changes in community biomass and composition along the south coast, the long-term trends in those factors, and possible changes experienced in recent years. Water column stability during spring, before the development of the red tide, followed by alternating periods of upwelling and relaxation during summer and autumn, seemed to promote the development and persistence of L. polyedrum. Recruitment of mussels and barnacles was estimated during the reproductive season of mussels in 2014, coinciding with the red tide, and during the following year. Alongshore patterns in recruitment were found, with higher mussel recruitment in the absence of the red tide and the opposite pattern in barnacles. Alongshore patterns in SST and chlorophyll matching those of recruitment were also found, with higher SSTs and lower chlorophyll during the red tide than the following year. Growth and mortality rates in barnacles did not differ between years during the first five months after settlement. This suggests that the factors which produced differences in recruitment between years did not produce carryover effects detectable at the temporal scales studied. Further analysis of 15 years of satellite-derived environmental data showed significant cooling trends potentially driven by a long-term seasonal acceleration of the Agulhas Current in autumn around two upwelling centres on the south coast, coinciding temporally with the reproductive period of mussels and barnacles, and spatially with the areas of highest recruitment. In addition, the comparison of SST and chl-a conditions during the first and the second half of the period of study showed that seasonality of both variables has changed in large areas over the shelf, with increasing importance of shorter-term variability, which would in turn decrease environmental predictability. Thus, the conditions observed during the present study, particularly during 2015, when upwelling seemed to be more intense, may presage the potential effects of identified long-term cooling trends at the upwelling centres. Although the general trend shows cooling around those areas, conditions can vary greatly among years, favouring different taxa. Changes in the Agulhas Current System are affected by changes in distant areas in the Indian Ocean basin. Such tele-connection is unlikely to be unique to this system and indicates the importance of understanding trends in major large scale climatic drivers and their regional effects in order to make predictions about coastal systems.
- Full Text:
- Authors: Muñiz, Carlota Fernández
- Date: 2019
- Subjects: Dinoflagellates -- South Africa , Coastal ecology -- South Africa , Climatic changes -- South Africa , Benthic ecology -- South Africa , Agulhas Current , Ocean temperature -- Agulhas Current , Ocean temperature -- Physiological effect
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/151541 , vital:39140
- Description: Marine systems are driven by the relationships among organisms and environmental conditions. Anthropogenic-induced changes during the past decades have started to alter climatic drivers which have the potential to alter the physical, chemical and biological environment. In coastal systems, biogeography is influenced by the temporal variability in the conditions of the water mass. In addition, many marine benthic organisms develop in the water mass and rely on the conditions that link the pelagic and benthic systems for population maintenance. Such pelagic-coastal coupling indicates that changes in the trophic system during development can be transferred to the adult populations through changes in propagule supply. Thus, changes in environmental conditions can influence benthic populations directly (e.g. through larval advection) or indirectly, through their influence on the phytoplankton community (e.g. through the development of HABs). The South African coastline shows clear alongshore patterns of faunal biomass and species richness. On the south coast, strong longitudinal patterns of recruitment of intertidal organisms exist, with areas of particularly high recruitment. HABs of unprecedented spatio-temporal magnitude have recently developed along the south coast, including the areas where benthic recruitment is most intense. The present thesis used these blooms to study changes in intertidal recruitment directly or indirectly associated with their occurrence. Using a combination of remote sensing data to study the environmental conditions of the water mass in the innermost part of the Agulhas Bank, and estimates of mussel and barnacle recruitment rates to integrate the effects of conditions in the water mass during larval development, this thesis aimed to: (1) understand the conditions that triggered the development of an HAB of the dinoflagellate Lingulodinium polyedrum during summer of 2014, (2) determine the direct or indirect effects of that bloom on recruitment of intertidal organisms, and understand the factors that affect recruitment along the coast, (3) determine if the environmental factors during bloom development produced any carryover effects on recruit growth and mortality, and (4) determine the factors that drive changes in community biomass and composition along the south coast, the long-term trends in those factors, and possible changes experienced in recent years. Water column stability during spring, before the development of the red tide, followed by alternating periods of upwelling and relaxation during summer and autumn, seemed to promote the development and persistence of L. polyedrum. Recruitment of mussels and barnacles was estimated during the reproductive season of mussels in 2014, coinciding with the red tide, and during the following year. Alongshore patterns in recruitment were found, with higher mussel recruitment in the absence of the red tide and the opposite pattern in barnacles. Alongshore patterns in SST and chlorophyll matching those of recruitment were also found, with higher SSTs and lower chlorophyll during the red tide than the following year. Growth and mortality rates in barnacles did not differ between years during the first five months after settlement. This suggests that the factors which produced differences in recruitment between years did not produce carryover effects detectable at the temporal scales studied. Further analysis of 15 years of satellite-derived environmental data showed significant cooling trends potentially driven by a long-term seasonal acceleration of the Agulhas Current in autumn around two upwelling centres on the south coast, coinciding temporally with the reproductive period of mussels and barnacles, and spatially with the areas of highest recruitment. In addition, the comparison of SST and chl-a conditions during the first and the second half of the period of study showed that seasonality of both variables has changed in large areas over the shelf, with increasing importance of shorter-term variability, which would in turn decrease environmental predictability. Thus, the conditions observed during the present study, particularly during 2015, when upwelling seemed to be more intense, may presage the potential effects of identified long-term cooling trends at the upwelling centres. Although the general trend shows cooling around those areas, conditions can vary greatly among years, favouring different taxa. Changes in the Agulhas Current System are affected by changes in distant areas in the Indian Ocean basin. Such tele-connection is unlikely to be unique to this system and indicates the importance of understanding trends in major large scale climatic drivers and their regional effects in order to make predictions about coastal systems.
- Full Text:
Learning to learn: a critical realist exploration into the home established learning practices of a marginalised community in Port Elizabeth
- Authors: Armstrong, Meredith
- Date: 2019
- Subjects: Minorities -- Education (Higher) -- South Africa , Readiness for school -- Social aspects -- South Africa , Inclusive education -- Social aspects -- South Africa , Marginality, Social -- South Africa , Critical realism
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/93778 , vital:30939
- Description: This study was completed as part of a project exploring social inclusion and exclusion in South African higher education. In a globalised world, the achievement of a qualification from an institution of higher education is increasingly key to finding any sort of employment. This is particularly the case in South Africa where employment amongst black citizens is inordinately high. The aim of the research reported upon in this thesis was to better understand the construct of ‘epistemological access’ (Morrow, 1992), often used in relation to the needs of black working class students entering higher education, in relation to performance data (see for example, CHE, 2016) that repeatedly shows that black students fare less well than their white peers. Following what might be termed a ‘social’ approach to understanding access, this study begins long before most students have even heard of higher education and focuses on identifying the mechanisms that come into play at much earlier level of learning and literacy development. The study outlines the development of ‘ways of being’, or social practices, surrounding learning in a marginalised community in Port Elizabeth, in the Eastern Cape, South Africa. This was achieved by means of critical ethnography and it is therefore qualitatively based. The study shows how social structures enable or constrain a child’s school readiness and how they then go on to support or impede progress in school where the language and literacy needed for educational success are further developed. The study therefore aims to allow us to explain global data indicating that the single greatest indicator of a young person’s ability to access and succeed in higher education is the level of education of caregivers in their homes of origin. Examined from a critical perspective (i.e. with a concern for social justice), this study has made use of a framework using social, psychological and linguistic theory and more, particularly, the work of sociologist Margaret Archer (1995, 1996, 2003). The study makes particular use of Archer’s ‘morphogenetic framework’ which allows for an analysis of the way structure and culture impact on a child’s development over time. As I was concerned that my own social status might impact on the understandings I developed as a critical ethnographer, the study acknowledges my own experiences of learning and the way my own family sought to enhance them as enabling. In doing this, the study aims to better contribute to understandings of social justice in South Africa.
- Full Text:
- Authors: Armstrong, Meredith
- Date: 2019
- Subjects: Minorities -- Education (Higher) -- South Africa , Readiness for school -- Social aspects -- South Africa , Inclusive education -- Social aspects -- South Africa , Marginality, Social -- South Africa , Critical realism
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/93778 , vital:30939
- Description: This study was completed as part of a project exploring social inclusion and exclusion in South African higher education. In a globalised world, the achievement of a qualification from an institution of higher education is increasingly key to finding any sort of employment. This is particularly the case in South Africa where employment amongst black citizens is inordinately high. The aim of the research reported upon in this thesis was to better understand the construct of ‘epistemological access’ (Morrow, 1992), often used in relation to the needs of black working class students entering higher education, in relation to performance data (see for example, CHE, 2016) that repeatedly shows that black students fare less well than their white peers. Following what might be termed a ‘social’ approach to understanding access, this study begins long before most students have even heard of higher education and focuses on identifying the mechanisms that come into play at much earlier level of learning and literacy development. The study outlines the development of ‘ways of being’, or social practices, surrounding learning in a marginalised community in Port Elizabeth, in the Eastern Cape, South Africa. This was achieved by means of critical ethnography and it is therefore qualitatively based. The study shows how social structures enable or constrain a child’s school readiness and how they then go on to support or impede progress in school where the language and literacy needed for educational success are further developed. The study therefore aims to allow us to explain global data indicating that the single greatest indicator of a young person’s ability to access and succeed in higher education is the level of education of caregivers in their homes of origin. Examined from a critical perspective (i.e. with a concern for social justice), this study has made use of a framework using social, psychological and linguistic theory and more, particularly, the work of sociologist Margaret Archer (1995, 1996, 2003). The study makes particular use of Archer’s ‘morphogenetic framework’ which allows for an analysis of the way structure and culture impact on a child’s development over time. As I was concerned that my own social status might impact on the understandings I developed as a critical ethnographer, the study acknowledges my own experiences of learning and the way my own family sought to enhance them as enabling. In doing this, the study aims to better contribute to understandings of social justice in South Africa.
- Full Text:
Listening to the Stories
- Pullanikkatil, Deepa, Shackleton, Charlie M
- Authors: Pullanikkatil, Deepa , Shackleton, Charlie M
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433565 , vital:72984 , ISBN 978-3-319-75580-9 , https://link.springer.com/chapter/10.1007/978-3-319-75580-9_25
- Description: This book has sought to contribute to the policy and academic debates regarding the opportunities and usefulness of the NTFP sector in reducing poverty. We have argued in the opening chapters that it is unlikely that NTFP use and trade will provide a pathway out of poverty for the millions of poor in the Global South. However, it is unlikely that any other one sector or intervention will. Consequently, the value of the NTFP sector and its role in poverty reduction for some needs to be added to the suite of strategies that governments, development agencies and NGOs consider when seeking to address poverty in the areas in which they operate.
- Full Text:
- Authors: Pullanikkatil, Deepa , Shackleton, Charlie M
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433565 , vital:72984 , ISBN 978-3-319-75580-9 , https://link.springer.com/chapter/10.1007/978-3-319-75580-9_25
- Description: This book has sought to contribute to the policy and academic debates regarding the opportunities and usefulness of the NTFP sector in reducing poverty. We have argued in the opening chapters that it is unlikely that NTFP use and trade will provide a pathway out of poverty for the millions of poor in the Global South. However, it is unlikely that any other one sector or intervention will. Consequently, the value of the NTFP sector and its role in poverty reduction for some needs to be added to the suite of strategies that governments, development agencies and NGOs consider when seeking to address poverty in the areas in which they operate.
- Full Text:
Livelihood benefits and costs from an invasive alien tree (Acacia dealbata) to rural communities in the Eastern Cape, South Africa
- Ngorima, A, Shackleton, Charlie M
- Authors: Ngorima, A , Shackleton, Charlie M
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/179755 , vital:43168 , xlink:href="https://doi.org/10.1016/j.jenvman.2018.05.077"
- Description: The negative effects of invasive alien species (IAS) are increasingly invoked to justify widespread and usually top-down approaches for their management or eradication. However, very little of the research or discourse is based on investigating local perceptions, uses and struggles with IAS, and how their presence influences and changes local livelihoods. The objective of this study was to assess the perceptions and livelihood uses of Acacia dealbata by local communities at three localities in the montane grasslands of the Eastern Cape, South Africa, using a combination of random household interviews, focus group discussions and participatory tools. We calculated direct-use values for each product and household (based on quantity used and local prices) and disaggregated these by gender of the household head and wealth quartiles. The results revealed the dualistic role of A. dealbata in local livelihoods. On the one hand, A. dealbata was widely used for firewood (100% of households), tools (77%) and construction timber (73%), with limited use for traditional medicines and forage. The cumulative value of approximately ZAR 2870 (±US$224) per household per year (across all households) represents considerable cash saving to households, most of whom are quite poor by national and international measures. On the other hand, the increasing extent of A. dealbata (93% said it was increasing) exacerbates local household vulnerability though reported reductions in cultivated areas, crop yields and forage production, and allegedly higher risks of crime. This quandary is well encapsulated by the considerable majority of respondents (84%) not wanting higher extents and densities of A. dealbata, but an equally high majority not wanting its total removal from local landscapes. Most respondents disliked A. dealbata in fields, close to homesteads or along primary access routes, and were more tolerant of it away from such sites. Institutional and use dynamics have varied over several decades in response to the changing extent and densities of A. dealbata and the broader political and socio-economic contexts. These results indicate that greater efforts are required to understand perceptions and uses of IAS by the people who live with them, and to direct such understanding into more spatially and temporally contextualised response strategies where required.
- Full Text:
- Authors: Ngorima, A , Shackleton, Charlie M
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/179755 , vital:43168 , xlink:href="https://doi.org/10.1016/j.jenvman.2018.05.077"
- Description: The negative effects of invasive alien species (IAS) are increasingly invoked to justify widespread and usually top-down approaches for their management or eradication. However, very little of the research or discourse is based on investigating local perceptions, uses and struggles with IAS, and how their presence influences and changes local livelihoods. The objective of this study was to assess the perceptions and livelihood uses of Acacia dealbata by local communities at three localities in the montane grasslands of the Eastern Cape, South Africa, using a combination of random household interviews, focus group discussions and participatory tools. We calculated direct-use values for each product and household (based on quantity used and local prices) and disaggregated these by gender of the household head and wealth quartiles. The results revealed the dualistic role of A. dealbata in local livelihoods. On the one hand, A. dealbata was widely used for firewood (100% of households), tools (77%) and construction timber (73%), with limited use for traditional medicines and forage. The cumulative value of approximately ZAR 2870 (±US$224) per household per year (across all households) represents considerable cash saving to households, most of whom are quite poor by national and international measures. On the other hand, the increasing extent of A. dealbata (93% said it was increasing) exacerbates local household vulnerability though reported reductions in cultivated areas, crop yields and forage production, and allegedly higher risks of crime. This quandary is well encapsulated by the considerable majority of respondents (84%) not wanting higher extents and densities of A. dealbata, but an equally high majority not wanting its total removal from local landscapes. Most respondents disliked A. dealbata in fields, close to homesteads or along primary access routes, and were more tolerant of it away from such sites. Institutional and use dynamics have varied over several decades in response to the changing extent and densities of A. dealbata and the broader political and socio-economic contexts. These results indicate that greater efforts are required to understand perceptions and uses of IAS by the people who live with them, and to direct such understanding into more spatially and temporally contextualised response strategies where required.
- Full Text:
Livestock water productivity: towards improving rural livelihoods from livestock in semi-arid rangelands
- Authors: Gusha, Bukho
- Date: 2019
- Subjects: Livestock -- South Africa -- Eastern Cape , Livestock -- Effect of drought on -- South Africa -- Eastern Cape , Animals -- Food -- South Africa -- Eastern Cape , Livestock -- Effect of water quality on -- South Africa -- Eastern Cape , Livestock -- Water requirements -- South Africa -- Eastern Cape , Livestock productivity -- South Africa -- Eastern Cape , Stochastic analysis , Communal rangelands -- South Africa -- Eastern Cape , Land degradation -- South Africa -- Eastern Cape , Animal owners -- South Africa -- Eastern Cape , Livestock improvement -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115171 , vital:34084
- Description: Communal rangelands in South Africa mainly occur in the former homelands. The former homelands constitute 13% of the land surface area and support a quarter of the country's human population with a wide range of goods and services, among them, grazing for livestock, mostly reared on communal rangelands. These rangelands are degraded and cannot sustain maximum livestock production because of poor species composition and low standing biomass, however research has been conducted on livestock production at household level (where all livestock goods and services are valued). This provides an opportunity to conduct a study describing livestock water productivity in the north of the Eastern Cape, where livestock production is a primary source of livelihood for rural communities from which many households generate cash but where different practices and factors undermine high livestock production. Many studies have focused on understanding the water productivity of a natural rangeland system for commercially oriented crop-livestock systems, but the aim of this study is to contribute towards improving rural livelihoods from livestock in the sub-humid rangelands of the north Eastern Cape. Here, unimproved native grasslands are the major source of feed for livestock and people do not have herders to take livestock to the most productive parts of the rangelands. Households were surveyed using a questionnaire on livestock household contribution, socioeconomic characteristics of the household, livestock holdings and livestock production strategies. Rangeland productivity was measured in the field. Experimental animals for livestock grazing distribution were identified and fitted with Global Positioning Systems (GPS) collars to identify the seasonal grazing areas. These activities shed light on the biophysical attributes of the ecosystem and livestock production in a communal rangeland system. Because continuous grazing in the rangelands of the north Eastern Cape reduces the standing biomass, there is no obvious aboveground biomass to provide a visual perspective of production nor is it possible to determine production without excluding the livestock. Thus, four parallel lines of evidence were employed to measure rangeland productivity: line intercept, grazing exclosures, net photosynthesis from earth observation and disc pasture meter. Earth observation products were used to derive the amount of water used by the landscape to produce this forage (i.e. evapotranspiration or ET) and these measurements of net primary production and landscape water use were used in preparing a value of livestock water productivity (LWP) for this farming system. There has been the perception that residents of the study area lack knowledge of technical efficiencies in the large stock sector at household level. The study used stochastic frontier analysis to assess livestock production and followed with a household survey to collect information on socio-economic characteristics and information on livestock practices. The data from the household survey were used to estimate the technical efficiency of households using a stochastic frontier analysis. Productivity and inefficiency variables that increase livestock production or increase technical difficulties were identified. The focus on livestock has mostly been on the direct value of livestock to owners with a poor understanding of their value to non-livestock owners, where cultural activities, such as livestock slaughtering, were documented as the only source of protein for non-livestock owners. However, the value that is available to non-livestock owners has not been quantified. This study assessed livestockbased livelihoods of communal people to improve their livelihoods through a household survey looking at the contribution of livestock to both livestock and non-livestock owners. Earlier work on LWP has focused on systems where animals were on ‘fed, cut and carry’ and irrigated systems. However, there is a need to describe LWP in a natural grazing system and this study set out to achieve this for these communal rangelands through a household survey that determined the value of livestock goods and services given the amount of water used (ET). Lastly, livestock grazing distribution across the landscape was assessed, using GPS collars that recorded livestock behaviour every five minutes during the daylight. This approach was necessary because livestock grazing patterns in these communal rangelands is poorly controlled by people, and animals are largely free-ranging, grazing selectively, based on their own preferences, which leads to localised overgrazing. This part of the study was achieved through experimental livestock collaring and weighing (both sheep and goats) for the wet and dry seasons. The collared livestock were weighed on the day of putting on collars and the day of removing the collars. The results on livestock grazing distribution were analysed using the R package, T-LoCoH. The major finding of this study was that communal rangelands of the north Eastern Cape can improve rural livelihoods from livestock if proper interventions for both livestock and rangeland production and productivity can be implemented. One of these interventions is fencing as it was found that exclosures that were fenced during the study yielded high aboveground productivity comparable to that achieved in commercial rangelands, yielding 220 g DM m-2 yr-1. Surveys using the calibrated disc pasture meter showed the need for proper rotation and resting of the rangeland. Net photosynthesis of 880.7 g C m-2 yr-1 for unimproved grassland in good condition was comparable to commercial rangelands in the region. Using the line intercept, vegetation cover was found to be a good predictor of aboveground standing biomass; thus a positive relationship was revealed. Lastly, annual ET of 270 mm yr-1 was calculated using the Penman Monteith Palmer (PMP) equation, while 379 mm yr-1 was extracted from the MOD16 product, suggesting that PMP ET may not be accurate in these grassland systems due to the slow response of MODIS Leaf Area Index (LAI). The average household technical efficiency (TE) score was found to be 0.79 on the study sites, indicating the potential for households to improve outputs from livestock. A range of household categories were identified, based on gender and an index of wealth, and households with lower and higher TE were identified. This analysis revealed that productivity variables such as holding higher livestock numbers and providing additional feed achieved high livestock outputs, suggesting high livestock productivity. However, in terms of inefficiency variables, gender (female-headed households), dwelling type (an index of homestead wealth), kraaling livestock at night and herding livestock during the day were found to improve technical efficiency. It was revealed in this study that households keep livestock to derive different goods and services including offtake, manure, milk, wool and services such as traction. The non-livestock owning households were reported to also benefit from the abovementioned goods and services in the study site and that the value of their contribution could be quantified, thus contributing significantly to rural livelihoods. The study showed that LWP was comparable with other studies such as those conducted in Ethiopia. This study compared its results with the studies conducted outside South Africa as there were limited comparable South African studies available; however, this does not necessarily mean we can use the same model as the value of livestock outputs varies based on the preferred outputs. This study developed an LWP model for the natural rangeland system. The LWP values were measured in ZAR and later converted in USD and were divided into three different categories based on the wealth index, such as better-off, middle wealth and poor households. Lastly, this study showed that livestock (both cattle and sheep) spend a high proportion of their grazing day, during both the wet and dry seasons, in a small physical area, immediately around the homesteads. These are areas where the active green growth occurs throughout the year, suggesting the need for livestock herders to move livestock around the landscape for more effective landscape use. Herding has the potential to improve landscape use and conserve grazing resource and the ability of a household to attain best outputs from livestock. Positive daily weight gains were reported in collared livestock during the wet season. However, both sheep and cattle lost weight during the dry season. This study recommends interventions such as labour for herding, and other animal husbandry-related activities including milking, handling, and vaccinating animals. Market opportunities for communal rangeland livestock should be facilitated by informing livestock owners about livestock market specifications to improve their livelihoods. Lastly, proper grazing management planning, such as fencing, which enables rotational grazing, and herding which moves animals to the most productive parts of the rangeland, should be implemented so that rangelands can be rested for plant growth, vigour, and improved aboveground net primary productivity. Based on the recommendations made in this study, a research development approach is necessary which prioritises female empowerment in agriculture and poor farmers as female-headed households were reported by this study to be more technically efficient.
- Full Text:
- Authors: Gusha, Bukho
- Date: 2019
- Subjects: Livestock -- South Africa -- Eastern Cape , Livestock -- Effect of drought on -- South Africa -- Eastern Cape , Animals -- Food -- South Africa -- Eastern Cape , Livestock -- Effect of water quality on -- South Africa -- Eastern Cape , Livestock -- Water requirements -- South Africa -- Eastern Cape , Livestock productivity -- South Africa -- Eastern Cape , Stochastic analysis , Communal rangelands -- South Africa -- Eastern Cape , Land degradation -- South Africa -- Eastern Cape , Animal owners -- South Africa -- Eastern Cape , Livestock improvement -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115171 , vital:34084
- Description: Communal rangelands in South Africa mainly occur in the former homelands. The former homelands constitute 13% of the land surface area and support a quarter of the country's human population with a wide range of goods and services, among them, grazing for livestock, mostly reared on communal rangelands. These rangelands are degraded and cannot sustain maximum livestock production because of poor species composition and low standing biomass, however research has been conducted on livestock production at household level (where all livestock goods and services are valued). This provides an opportunity to conduct a study describing livestock water productivity in the north of the Eastern Cape, where livestock production is a primary source of livelihood for rural communities from which many households generate cash but where different practices and factors undermine high livestock production. Many studies have focused on understanding the water productivity of a natural rangeland system for commercially oriented crop-livestock systems, but the aim of this study is to contribute towards improving rural livelihoods from livestock in the sub-humid rangelands of the north Eastern Cape. Here, unimproved native grasslands are the major source of feed for livestock and people do not have herders to take livestock to the most productive parts of the rangelands. Households were surveyed using a questionnaire on livestock household contribution, socioeconomic characteristics of the household, livestock holdings and livestock production strategies. Rangeland productivity was measured in the field. Experimental animals for livestock grazing distribution were identified and fitted with Global Positioning Systems (GPS) collars to identify the seasonal grazing areas. These activities shed light on the biophysical attributes of the ecosystem and livestock production in a communal rangeland system. Because continuous grazing in the rangelands of the north Eastern Cape reduces the standing biomass, there is no obvious aboveground biomass to provide a visual perspective of production nor is it possible to determine production without excluding the livestock. Thus, four parallel lines of evidence were employed to measure rangeland productivity: line intercept, grazing exclosures, net photosynthesis from earth observation and disc pasture meter. Earth observation products were used to derive the amount of water used by the landscape to produce this forage (i.e. evapotranspiration or ET) and these measurements of net primary production and landscape water use were used in preparing a value of livestock water productivity (LWP) for this farming system. There has been the perception that residents of the study area lack knowledge of technical efficiencies in the large stock sector at household level. The study used stochastic frontier analysis to assess livestock production and followed with a household survey to collect information on socio-economic characteristics and information on livestock practices. The data from the household survey were used to estimate the technical efficiency of households using a stochastic frontier analysis. Productivity and inefficiency variables that increase livestock production or increase technical difficulties were identified. The focus on livestock has mostly been on the direct value of livestock to owners with a poor understanding of their value to non-livestock owners, where cultural activities, such as livestock slaughtering, were documented as the only source of protein for non-livestock owners. However, the value that is available to non-livestock owners has not been quantified. This study assessed livestockbased livelihoods of communal people to improve their livelihoods through a household survey looking at the contribution of livestock to both livestock and non-livestock owners. Earlier work on LWP has focused on systems where animals were on ‘fed, cut and carry’ and irrigated systems. However, there is a need to describe LWP in a natural grazing system and this study set out to achieve this for these communal rangelands through a household survey that determined the value of livestock goods and services given the amount of water used (ET). Lastly, livestock grazing distribution across the landscape was assessed, using GPS collars that recorded livestock behaviour every five minutes during the daylight. This approach was necessary because livestock grazing patterns in these communal rangelands is poorly controlled by people, and animals are largely free-ranging, grazing selectively, based on their own preferences, which leads to localised overgrazing. This part of the study was achieved through experimental livestock collaring and weighing (both sheep and goats) for the wet and dry seasons. The collared livestock were weighed on the day of putting on collars and the day of removing the collars. The results on livestock grazing distribution were analysed using the R package, T-LoCoH. The major finding of this study was that communal rangelands of the north Eastern Cape can improve rural livelihoods from livestock if proper interventions for both livestock and rangeland production and productivity can be implemented. One of these interventions is fencing as it was found that exclosures that were fenced during the study yielded high aboveground productivity comparable to that achieved in commercial rangelands, yielding 220 g DM m-2 yr-1. Surveys using the calibrated disc pasture meter showed the need for proper rotation and resting of the rangeland. Net photosynthesis of 880.7 g C m-2 yr-1 for unimproved grassland in good condition was comparable to commercial rangelands in the region. Using the line intercept, vegetation cover was found to be a good predictor of aboveground standing biomass; thus a positive relationship was revealed. Lastly, annual ET of 270 mm yr-1 was calculated using the Penman Monteith Palmer (PMP) equation, while 379 mm yr-1 was extracted from the MOD16 product, suggesting that PMP ET may not be accurate in these grassland systems due to the slow response of MODIS Leaf Area Index (LAI). The average household technical efficiency (TE) score was found to be 0.79 on the study sites, indicating the potential for households to improve outputs from livestock. A range of household categories were identified, based on gender and an index of wealth, and households with lower and higher TE were identified. This analysis revealed that productivity variables such as holding higher livestock numbers and providing additional feed achieved high livestock outputs, suggesting high livestock productivity. However, in terms of inefficiency variables, gender (female-headed households), dwelling type (an index of homestead wealth), kraaling livestock at night and herding livestock during the day were found to improve technical efficiency. It was revealed in this study that households keep livestock to derive different goods and services including offtake, manure, milk, wool and services such as traction. The non-livestock owning households were reported to also benefit from the abovementioned goods and services in the study site and that the value of their contribution could be quantified, thus contributing significantly to rural livelihoods. The study showed that LWP was comparable with other studies such as those conducted in Ethiopia. This study compared its results with the studies conducted outside South Africa as there were limited comparable South African studies available; however, this does not necessarily mean we can use the same model as the value of livestock outputs varies based on the preferred outputs. This study developed an LWP model for the natural rangeland system. The LWP values were measured in ZAR and later converted in USD and were divided into three different categories based on the wealth index, such as better-off, middle wealth and poor households. Lastly, this study showed that livestock (both cattle and sheep) spend a high proportion of their grazing day, during both the wet and dry seasons, in a small physical area, immediately around the homesteads. These are areas where the active green growth occurs throughout the year, suggesting the need for livestock herders to move livestock around the landscape for more effective landscape use. Herding has the potential to improve landscape use and conserve grazing resource and the ability of a household to attain best outputs from livestock. Positive daily weight gains were reported in collared livestock during the wet season. However, both sheep and cattle lost weight during the dry season. This study recommends interventions such as labour for herding, and other animal husbandry-related activities including milking, handling, and vaccinating animals. Market opportunities for communal rangeland livestock should be facilitated by informing livestock owners about livestock market specifications to improve their livelihoods. Lastly, proper grazing management planning, such as fencing, which enables rotational grazing, and herding which moves animals to the most productive parts of the rangeland, should be implemented so that rangelands can be rested for plant growth, vigour, and improved aboveground net primary productivity. Based on the recommendations made in this study, a research development approach is necessary which prioritises female empowerment in agriculture and poor farmers as female-headed households were reported by this study to be more technically efficient.
- Full Text:
Machine learning methods for calibrating radio interferometric data
- Authors: Zitha, Simphiwe Nhlanhla
- Date: 2019
- Subjects: Calibration , Radio astronomy -- Data processing , Radio astronomy -- South Africa , Karoo Array Telescope (South Africa) , Radio telescopes -- South Africa , Common Astronomy Software Application (Computer software)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/97096 , vital:31398
- Description: The applications of machine learning have created an opportunity to deal with complex problems currently encountered in radio astronomy data processing. Calibration is one of the most important data processing steps required to produce high dynamic range images. This process involves the determination of calibration parameters, both instrumental and astronomical, to correct the collected data. Typically, astronomers use a package such as Common Astronomy Software Applications (CASA) to compute the gain solutions based on regular observations of a known calibrator source. In this work we present applications of machine learning to first generation calibration (1GC), using the KAT-7 telescope environmental and pointing sensor data recorded during observations. Applying machine learning to 1GC, as opposed to calculating the gain solutions in CASA, has shown evidence of reducing computation, as well as accurately predict the 1GC gain solutions representing the behaviour of the antenna during an observation. These methods are computationally less expensive, however they have not fully learned to generalise in predicting accurate 1GC solutions by looking at environmental and pointing sensors. We call this multi-output regression model ZCal, which is based on random forest, decision trees, extremely randomized trees and K-nearest neighbor algorithms. The prediction error obtained during the testing of our model on testing data is ≈ 0.01 < rmse < 0.09 for gain amplitude per antenna, and 0.2 rad < rmse <0.5 rad for gain phase. This shows that the instrumental parameters used to train our model more strongly correlate with gain amplitude effects than phase.
- Full Text:
- Authors: Zitha, Simphiwe Nhlanhla
- Date: 2019
- Subjects: Calibration , Radio astronomy -- Data processing , Radio astronomy -- South Africa , Karoo Array Telescope (South Africa) , Radio telescopes -- South Africa , Common Astronomy Software Application (Computer software)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/97096 , vital:31398
- Description: The applications of machine learning have created an opportunity to deal with complex problems currently encountered in radio astronomy data processing. Calibration is one of the most important data processing steps required to produce high dynamic range images. This process involves the determination of calibration parameters, both instrumental and astronomical, to correct the collected data. Typically, astronomers use a package such as Common Astronomy Software Applications (CASA) to compute the gain solutions based on regular observations of a known calibrator source. In this work we present applications of machine learning to first generation calibration (1GC), using the KAT-7 telescope environmental and pointing sensor data recorded during observations. Applying machine learning to 1GC, as opposed to calculating the gain solutions in CASA, has shown evidence of reducing computation, as well as accurately predict the 1GC gain solutions representing the behaviour of the antenna during an observation. These methods are computationally less expensive, however they have not fully learned to generalise in predicting accurate 1GC solutions by looking at environmental and pointing sensors. We call this multi-output regression model ZCal, which is based on random forest, decision trees, extremely randomized trees and K-nearest neighbor algorithms. The prediction error obtained during the testing of our model on testing data is ≈ 0.01 < rmse < 0.09 for gain amplitude per antenna, and 0.2 rad < rmse <0.5 rad for gain phase. This shows that the instrumental parameters used to train our model more strongly correlate with gain amplitude effects than phase.
- Full Text:
Magnetic nanoparticle-indium phthalocyanine conjugate embedded in electrospun fiber for photodynamic antimicrobial chemotherapy and photodegradation of methyl red
- Sindelo, Azole, Nyokong, Tebello
- Authors: Sindelo, Azole , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186857 , vital:44540 , xlink:href="https://doi.org/10.1016/j.heliyon.2019.e02352"
- Description: ClIn(III) octacarboxy phthalocyanine (ClInOCPc) when alone or conjugated to magnetic nanoparticles (MNPClInOCPc) was employed for both photodynamic antimicrobial chemotherapy of an unknown water sample and Staphylococcus aureus, and for photo-degradation of methyl red (MR). The singlet oxygen quantum yields (ΦΔ) in water using ClInOCPc and MNP-ClInOCPc embedded in polyacrylonitrile (PAN) electrospun fibers were 0.36 and 0.22, respectively. When in solution, MNP-ClInOCPc gave 90.6% photoinactivation of microbes in a water sample from the stream and of ClInOCPc resulted in 84.8 % photoinactivation. When embedded to the polymer, there was 48.0% clearance for ClInOCPc and 63.7% clearance for MNP-ClInOCPc for the microbes in the water sample from the stream. For the photo-degradation of MR, the rate of degradation increased with decrease of the MR concentration with the MNP-ClInOCPc having the fastest rate.
- Full Text:
- Authors: Sindelo, Azole , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186857 , vital:44540 , xlink:href="https://doi.org/10.1016/j.heliyon.2019.e02352"
- Description: ClIn(III) octacarboxy phthalocyanine (ClInOCPc) when alone or conjugated to magnetic nanoparticles (MNPClInOCPc) was employed for both photodynamic antimicrobial chemotherapy of an unknown water sample and Staphylococcus aureus, and for photo-degradation of methyl red (MR). The singlet oxygen quantum yields (ΦΔ) in water using ClInOCPc and MNP-ClInOCPc embedded in polyacrylonitrile (PAN) electrospun fibers were 0.36 and 0.22, respectively. When in solution, MNP-ClInOCPc gave 90.6% photoinactivation of microbes in a water sample from the stream and of ClInOCPc resulted in 84.8 % photoinactivation. When embedded to the polymer, there was 48.0% clearance for ClInOCPc and 63.7% clearance for MNP-ClInOCPc for the microbes in the water sample from the stream. For the photo-degradation of MR, the rate of degradation increased with decrease of the MR concentration with the MNP-ClInOCPc having the fastest rate.
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Mainstreaming education for sustainable development: Elaborating the role of position-practice systems using seven laminations of scale
- Agbedahin, Adesuwa V, Lotz-Sisitka, Heila
- Authors: Agbedahin, Adesuwa V , Lotz-Sisitka, Heila
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182428 , vital:43829 , xlink:href="https://doi.org/10.1080/14767430.2019.1602975"
- Description: The United Nations Sustainable Development Goal 4.7 proposes that Education for Sustainable Development (ESD) should be included at all levels of education, known as ‘mainstreaming’. However, there is little guidance as to how to achieve this. ESD mainstreaming demands more than simply a technical policy transfer; it also requires attention to the position-practice systems of involved agents. This article critically assesses the mainstreaming of ESD in the case of university educators in Africa who have participated in the International Training Programme on ESD in higher education. It clarifies their position-practice systems in terms of Bhaskar’s seven laminations of scale. This article therefore provides a detailed description of the ways in which agents' position-practice systems enable and constrain ESD mainstreaming. It also demonstrates that a critical realist perspective can contribute towards the understanding and achievement of transformation towards sustainability and can help to ensure the flourishing of both current and future generations.
- Full Text:
- Authors: Agbedahin, Adesuwa V , Lotz-Sisitka, Heila
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182428 , vital:43829 , xlink:href="https://doi.org/10.1080/14767430.2019.1602975"
- Description: The United Nations Sustainable Development Goal 4.7 proposes that Education for Sustainable Development (ESD) should be included at all levels of education, known as ‘mainstreaming’. However, there is little guidance as to how to achieve this. ESD mainstreaming demands more than simply a technical policy transfer; it also requires attention to the position-practice systems of involved agents. This article critically assesses the mainstreaming of ESD in the case of university educators in Africa who have participated in the International Training Programme on ESD in higher education. It clarifies their position-practice systems in terms of Bhaskar’s seven laminations of scale. This article therefore provides a detailed description of the ways in which agents' position-practice systems enable and constrain ESD mainstreaming. It also demonstrates that a critical realist perspective can contribute towards the understanding and achievement of transformation towards sustainability and can help to ensure the flourishing of both current and future generations.
- Full Text:
Making (non) sense of urban water flows: Qualities and processes for transformative and transgressive learning moments
- Authors: James, Anna
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/390665 , vital:68572 , xlink:href="https://doi.org/10.3390/su11236817"
- Description: Urban sustainability and justice depend upon the flow of water across complex urban space. Yet, the characteristics of urban space produce a fragmented sense of our water resources. Cape Town, South Africa, the context of this research, is one such city whose water challenges have been exacerbated by climate change-induced drought, to the extent that the city nearly shut off the water running to residents’ taps. This context presents a particular challenge for the focus of this special issue, transformative and transgressive learning, an emerging arena of thought and practice concerned with learning processes that might foster more sustainable socio-ecological relations. The empirical material for this research draws from 12 arts-based inquiry workshops run with youth in an environmental organisation over four months, exploring a local water crisis. The data were generated through an engaged arts-based research process. The paper traces how transformative and transgressive learning in the context of urban water crisis might be characterised as making (non)sense by bringing the empirical material into dialogue with five entry points of transformative and transgressive learning literature rooted in Freirean educational praxis. This paper crafts and engages the concept of making (non)sense, a way of thinking about qualities and processes of learning praxis that responds to the wicked sustainability challenges we face today, particularly in terms of a Global South perspective. I argue such a praxis needs qualities and processes that disrupt and trouble the norm in the context of the socio-ecological challenge of urban water.
- Full Text:
- Authors: James, Anna
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/390665 , vital:68572 , xlink:href="https://doi.org/10.3390/su11236817"
- Description: Urban sustainability and justice depend upon the flow of water across complex urban space. Yet, the characteristics of urban space produce a fragmented sense of our water resources. Cape Town, South Africa, the context of this research, is one such city whose water challenges have been exacerbated by climate change-induced drought, to the extent that the city nearly shut off the water running to residents’ taps. This context presents a particular challenge for the focus of this special issue, transformative and transgressive learning, an emerging arena of thought and practice concerned with learning processes that might foster more sustainable socio-ecological relations. The empirical material for this research draws from 12 arts-based inquiry workshops run with youth in an environmental organisation over four months, exploring a local water crisis. The data were generated through an engaged arts-based research process. The paper traces how transformative and transgressive learning in the context of urban water crisis might be characterised as making (non)sense by bringing the empirical material into dialogue with five entry points of transformative and transgressive learning literature rooted in Freirean educational praxis. This paper crafts and engages the concept of making (non)sense, a way of thinking about qualities and processes of learning praxis that responds to the wicked sustainability challenges we face today, particularly in terms of a Global South perspective. I argue such a praxis needs qualities and processes that disrupt and trouble the norm in the context of the socio-ecological challenge of urban water.
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Making meaning of reality television celebrities: the reception of South African Idol by young adults in Joza, Grahamstown
- Authors: Magade, Mncedi Eddie
- Date: 2019
- Subjects: Talent shows (Television programs) -- South Africa , Television viewers -- South Africa , Television programs -- South Africa , Mass media -- South Africa , South African Idol (Television program) , Reality television shows
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/94217 , vital:31018
- Description: Reality television or “factual entertainment” is a hybrid of old television formats and factual programming in order to create a “new” entertaining show designed to draw the attention of audiences and increase viewership ratings. South African Idol is one popular local example. Adapted from the British programme Pop Idol, the show promises upward mobility for the young star who wins the competition. This show has become a subject of conversation amongst young people in South Africa who aspire to the “success” and “celebrity” status that is produced by participating on the show. This paper uses a Cultural Studies framework in order to examine the relationship between texts and audiences as an aspect of the “circuit of culture,” with its interrelated moments of production, texts, consumption and lived experience. My research focuses on the text and audience “moments” of this circuit. Audience studies research suggests that we should situate television viewing and the meanings made of TV programs in the natural setting of the home, and that this setting should be taken seriously as a unit of analysis. This study therefore, seeks to understand the ways in which audiences make meaning of this television programme within the domestic context.
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- Authors: Magade, Mncedi Eddie
- Date: 2019
- Subjects: Talent shows (Television programs) -- South Africa , Television viewers -- South Africa , Television programs -- South Africa , Mass media -- South Africa , South African Idol (Television program) , Reality television shows
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/94217 , vital:31018
- Description: Reality television or “factual entertainment” is a hybrid of old television formats and factual programming in order to create a “new” entertaining show designed to draw the attention of audiences and increase viewership ratings. South African Idol is one popular local example. Adapted from the British programme Pop Idol, the show promises upward mobility for the young star who wins the competition. This show has become a subject of conversation amongst young people in South Africa who aspire to the “success” and “celebrity” status that is produced by participating on the show. This paper uses a Cultural Studies framework in order to examine the relationship between texts and audiences as an aspect of the “circuit of culture,” with its interrelated moments of production, texts, consumption and lived experience. My research focuses on the text and audience “moments” of this circuit. Audience studies research suggests that we should situate television viewing and the meanings made of TV programs in the natural setting of the home, and that this setting should be taken seriously as a unit of analysis. This study therefore, seeks to understand the ways in which audiences make meaning of this television programme within the domestic context.
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Mapping and predicting potential distribution patterns of free-range livestock in the rural communal rangelands of Mgwalana, Eastern Cape, South Africa
- Authors: Mkabile, Qawekazi
- Date: 2019
- Subjects: Range management -- South Africa , Grazing -- South Africa , Livestock -- South Africa , Livestock -- Monitoring -- South Africa , Livestock -- Remote sensing -- South Africa , Communal rangelands -- South Africa
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/96000 , vital:31223
- Description: Communal rangelands provide habitat to many plants and animals. However, there is evidence that livestock cause range degradation. Range degradation occurs because livestock select grazing based on the availability of resources such as water and forage material, their use of the landscape is non-uniform, consequently causing resource deterioration. Range management is thus necessary because communities depend on range condition for livestock productivity. However, precise quantification of livestock distribution within communal rangelands is lacking. In developed countries, Global Positioning Systems (GPS) collars have been used to monitor wildlife and domestic livestock in pastures and seem to have worked efficiently. However, in a developing country like South Africa, GPS technology to monitor animal behaviour has been used only for wildlife on privately owned land. The high costs of monitoring livestock herds in large open areas such as communal rangelands have resulted in little or no monitoring of domestic livestock using GPS technology. This study links monitored livestock distribution to physical landscape variables in Mgwalana, and uses the modelled relationship to predict livestock distribution in quaternary catchments, T12A and T35A-E. The research addresses the questions (1) where do livestock spend time in the wet and dry seasons? And (2) how can areas of potential livestock distribution be identified in other catchments where actual distribution is unknown? Livestock were tracked during the wet and dry seasons using GPS collars. The resulting distribution data is combined with selected physical landscape variables to identify selectivity. The GPS location data and the physical landscape variables are used to predict potential livestock distribution where distribution is unknown in quaternary catchments (T12A and T35A-E). The ArcGIS Predictive Analysis Tool (PAT) was used to extract the selected landscape variable ranges based on the GPS location data and identify areas with the same conditions in the quaternary catchments were subsequently selected. The key findings are that livestock prefer accessible areas with gentle terrain near water sources, avoiding south-facing slopes which receive less solar radiation and tend to be cooler. Livestock are attracted to vegetation in riparian zones. Rural communal lands are dominated by poverty, and land-based livelihood strategies can potentially contribute to the well-being of the community. Therefore, understanding livestock distribution can contribute to a rangeland management strategy aimed at improving range condition which could increase livestock productivity and contribute to the livelihoods of local people.
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- Authors: Mkabile, Qawekazi
- Date: 2019
- Subjects: Range management -- South Africa , Grazing -- South Africa , Livestock -- South Africa , Livestock -- Monitoring -- South Africa , Livestock -- Remote sensing -- South Africa , Communal rangelands -- South Africa
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/96000 , vital:31223
- Description: Communal rangelands provide habitat to many plants and animals. However, there is evidence that livestock cause range degradation. Range degradation occurs because livestock select grazing based on the availability of resources such as water and forage material, their use of the landscape is non-uniform, consequently causing resource deterioration. Range management is thus necessary because communities depend on range condition for livestock productivity. However, precise quantification of livestock distribution within communal rangelands is lacking. In developed countries, Global Positioning Systems (GPS) collars have been used to monitor wildlife and domestic livestock in pastures and seem to have worked efficiently. However, in a developing country like South Africa, GPS technology to monitor animal behaviour has been used only for wildlife on privately owned land. The high costs of monitoring livestock herds in large open areas such as communal rangelands have resulted in little or no monitoring of domestic livestock using GPS technology. This study links monitored livestock distribution to physical landscape variables in Mgwalana, and uses the modelled relationship to predict livestock distribution in quaternary catchments, T12A and T35A-E. The research addresses the questions (1) where do livestock spend time in the wet and dry seasons? And (2) how can areas of potential livestock distribution be identified in other catchments where actual distribution is unknown? Livestock were tracked during the wet and dry seasons using GPS collars. The resulting distribution data is combined with selected physical landscape variables to identify selectivity. The GPS location data and the physical landscape variables are used to predict potential livestock distribution where distribution is unknown in quaternary catchments (T12A and T35A-E). The ArcGIS Predictive Analysis Tool (PAT) was used to extract the selected landscape variable ranges based on the GPS location data and identify areas with the same conditions in the quaternary catchments were subsequently selected. The key findings are that livestock prefer accessible areas with gentle terrain near water sources, avoiding south-facing slopes which receive less solar radiation and tend to be cooler. Livestock are attracted to vegetation in riparian zones. Rural communal lands are dominated by poverty, and land-based livelihood strategies can potentially contribute to the well-being of the community. Therefore, understanding livestock distribution can contribute to a rangeland management strategy aimed at improving range condition which could increase livestock productivity and contribute to the livelihoods of local people.
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Masked in metaphors: counter narratives in the works of Nigerian cartoonist Mike Asukwo
- Authors: Jimoh, Ganiyu A
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145974 , vital:38483 , https://0-doi.org.wam.seals.ac.za/10.1162/afar_a_00458
- Description: At the time of independence, most African countries were poised to take charge of their own affairs. However, postcolonial realities characterized by political upheavals, coups and counter-coups, civil wars, and economic downturn, among other setbacks, created a sense of ambivalence in terms of political and economic freedom. In Nigeria, satirical expressions became the tool used against oppressive regimes. In post-independence Nigeria, from the military dictatorial era to the present civilian dispensations,1 sociopolitical issues have been lampooned in different forms of expression such as music, performance, cartoons, and memes. Within this environment, political cartoons began to thrive, as they became a relatively safe way to comment on the political issues of the day (Akande 2002: 2). This was achieved largely by concealing the main subject matter behind the “masks” of metaphoric imagery, which enabled cartoonists to develop narratives that counter the dominant narratives, often opposing governmental policies and practices.
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- Authors: Jimoh, Ganiyu A
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145974 , vital:38483 , https://0-doi.org.wam.seals.ac.za/10.1162/afar_a_00458
- Description: At the time of independence, most African countries were poised to take charge of their own affairs. However, postcolonial realities characterized by political upheavals, coups and counter-coups, civil wars, and economic downturn, among other setbacks, created a sense of ambivalence in terms of political and economic freedom. In Nigeria, satirical expressions became the tool used against oppressive regimes. In post-independence Nigeria, from the military dictatorial era to the present civilian dispensations,1 sociopolitical issues have been lampooned in different forms of expression such as music, performance, cartoons, and memes. Within this environment, political cartoons began to thrive, as they became a relatively safe way to comment on the political issues of the day (Akande 2002: 2). This was achieved largely by concealing the main subject matter behind the “masks” of metaphoric imagery, which enabled cartoonists to develop narratives that counter the dominant narratives, often opposing governmental policies and practices.
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Mating preferences of two species of Eccritotarsus (Hemiptera: Miridae)
- Authors: Mnuguni, Sandiso
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417486 , vital:71457 , xlink:href="https://hdl.handle.net/10520/ejc-cristal-v10-n1-a7"
- Description: Eccritotarsus spp. are biological control agents that have been sourced from Brazil and Peru to control water hyacinth in South Africa. These agents have been released in over 30 sites and were thought to be the same species. The sequencing of mitochondrial DNA and interbreeding experiments have since confirmed the cryptic species to be separate species. The Brazilian population remains E. catarinensis while the Peruvian population is now E. eichhorniae. This paper assessed the mating behaviour of both species, to investigate behavioural traits that have resulted in reproductive isolation, which could have led to speciation. Mating choices in a form of no-choice, bi-choice and multi-choice tests were conducted within and between species in a 3:1, 2:1 and 1:1 sex ratio. The E. eichhorniae pair had more single and multiple copula incidences, higher average total copula duration and higher copula latency while the E.catarinensis♀×E.eichhorniae♂ pair had less single and multiple copula incidences, lower average total copula duration and lower copula latency. When the E.eichhorniae♀ and E.catarinensis♂ were given their respective choices, they only mated with conspecifics. However, when E.eichhorniae♀ are crossed with E.catarinensis♂ they do not produce offspring. These results suggest that interbreeding will be limited in South Africa.
- Full Text:
- Authors: Mnuguni, Sandiso
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417486 , vital:71457 , xlink:href="https://hdl.handle.net/10520/ejc-cristal-v10-n1-a7"
- Description: Eccritotarsus spp. are biological control agents that have been sourced from Brazil and Peru to control water hyacinth in South Africa. These agents have been released in over 30 sites and were thought to be the same species. The sequencing of mitochondrial DNA and interbreeding experiments have since confirmed the cryptic species to be separate species. The Brazilian population remains E. catarinensis while the Peruvian population is now E. eichhorniae. This paper assessed the mating behaviour of both species, to investigate behavioural traits that have resulted in reproductive isolation, which could have led to speciation. Mating choices in a form of no-choice, bi-choice and multi-choice tests were conducted within and between species in a 3:1, 2:1 and 1:1 sex ratio. The E. eichhorniae pair had more single and multiple copula incidences, higher average total copula duration and higher copula latency while the E.catarinensis♀×E.eichhorniae♂ pair had less single and multiple copula incidences, lower average total copula duration and lower copula latency. When the E.eichhorniae♀ and E.catarinensis♂ were given their respective choices, they only mated with conspecifics. However, when E.eichhorniae♀ are crossed with E.catarinensis♂ they do not produce offspring. These results suggest that interbreeding will be limited in South Africa.
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Measuring and modelling evapotranspiration in a South African grassland: Comparison of two improved Penman-Monteith formulations
- Gwate, Onalenna, Mantel, Sukhmani K, Palmer, Anthony R, Gibson, Lesley A, Munch, Zahn
- Authors: Gwate, Onalenna , Mantel, Sukhmani K , Palmer, Anthony R , Gibson, Lesley A , Munch, Zahn
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/438167 , vital:73440 , ISBN 1816-7950 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/44_03_16_3530.pdf
- Description: Accurately measuring evapotranspiration (ET) is important in the con-text of global atmospheric changes and for use with climate models. Direct ET measurement is costly to apply widely and local calibration and validation of ET models developed elsewhere improves confidence in ET derived from such models. is study sought to compare the per-formance of the Penman-Monteith-Leuning (PML) and Penman-Monteith-Palmer (PMP) ET models, over mesic grasslands in two study sites in South Africa. The study used routine meteorological data from a scientific-grade automatic weather station (AWS) to apply the PML and PMP models. The PML model was calibrated at one site and validated in both sites. On the other hand, the PMP model does not require cali-bration and hence it was validated in both sites.
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- Authors: Gwate, Onalenna , Mantel, Sukhmani K , Palmer, Anthony R , Gibson, Lesley A , Munch, Zahn
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/438167 , vital:73440 , ISBN 1816-7950 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/44_03_16_3530.pdf
- Description: Accurately measuring evapotranspiration (ET) is important in the con-text of global atmospheric changes and for use with climate models. Direct ET measurement is costly to apply widely and local calibration and validation of ET models developed elsewhere improves confidence in ET derived from such models. is study sought to compare the per-formance of the Penman-Monteith-Leuning (PML) and Penman-Monteith-Palmer (PMP) ET models, over mesic grasslands in two study sites in South Africa. The study used routine meteorological data from a scientific-grade automatic weather station (AWS) to apply the PML and PMP models. The PML model was calibrated at one site and validated in both sites. On the other hand, the PMP model does not require cali-bration and hence it was validated in both sites.
- Full Text: