Singing and Drum playing
- Unnamed
- Authors: Unnamed
- Date: 2015
- Subjects: UNCATALOGUED
- Type: Video
- Identifier: http://hdl.handle.net/10962/303179 , vital:58302 , KHV-260
- Description: Traditional healers singing and playing drums , Use of this resource is governed by the terms and conditions of the Creative Commons "Attribution-NonCommercial-ShareAlike" License (http://creativecommons.org/licenses/by-nc-sa/2.0/) (NEVER CAHNGE THIS FIELD)
- Full Text: false
- Date Issued: 2015
- Authors: Unnamed
- Date: 2015
- Subjects: UNCATALOGUED
- Type: Video
- Identifier: http://hdl.handle.net/10962/303179 , vital:58302 , KHV-260
- Description: Traditional healers singing and playing drums , Use of this resource is governed by the terms and conditions of the Creative Commons "Attribution-NonCommercial-ShareAlike" License (http://creativecommons.org/licenses/by-nc-sa/2.0/) (NEVER CAHNGE THIS FIELD)
- Full Text: false
- Date Issued: 2015
Single event upset testing of flash based field programmable gate arrays
- Authors: Potgieter, Juan-Pierre
- Date: 2015
- Subjects: Field programmable gate arrays
- Language: English
- Type: Thesis , Masters , MEngineering
- Identifier: http://hdl.handle.net/10948/12520 , vital:27083
- Description: In the last 50 years microelectronics have advanced at an exponential rate, causing microelectronic devices to shrink, have very low operating voltages and increased complexities; all this has made circuits more sensitive to various kinds of failures. These trends allowed soft errors, which up until recently was just a concern for space application, to become a major source of system failures of electronic products. The aim of this research paper was to investigate different mitigation techniques that prevent these soft errors in a Video Graphics Array (VGA) controller which is commonly used in projecting images captured by cameras. This controller was implemented on a Flash Based Field Programmable Gate array (FPGA). A test set-up was designed and implemented at NRF iThemba LABS, which was used to conduct the experiments necessary to evaluate the effectiveness of different mitigation techniques. The set-up was capable of handling multiple Device Under Tests (DUT) and had the ability to change the angle of incidence of each DUT. The DUTs were radiated with a 66MeV proton beam while the monitoring equipment observed any errors that had occurred. The results obtained indicated that all the implemented mitigation techniques tested on the VGA system improved the system’s capability of mitigating Single Event Upsets (SEU). The most effective mitigation technique was the OR-AND Multiplexer Single Event Transient (SET) filter technique. It was thus shown that mitigation techniques are viable options to prevent SEU in a VGA controller. The permanent SEU testing set-up which was designed and manufactured and was used to conduct the experiments, proved to be a practical option for further microelectronics testing at iThemba LABS.
- Full Text:
- Date Issued: 2015
- Authors: Potgieter, Juan-Pierre
- Date: 2015
- Subjects: Field programmable gate arrays
- Language: English
- Type: Thesis , Masters , MEngineering
- Identifier: http://hdl.handle.net/10948/12520 , vital:27083
- Description: In the last 50 years microelectronics have advanced at an exponential rate, causing microelectronic devices to shrink, have very low operating voltages and increased complexities; all this has made circuits more sensitive to various kinds of failures. These trends allowed soft errors, which up until recently was just a concern for space application, to become a major source of system failures of electronic products. The aim of this research paper was to investigate different mitigation techniques that prevent these soft errors in a Video Graphics Array (VGA) controller which is commonly used in projecting images captured by cameras. This controller was implemented on a Flash Based Field Programmable Gate array (FPGA). A test set-up was designed and implemented at NRF iThemba LABS, which was used to conduct the experiments necessary to evaluate the effectiveness of different mitigation techniques. The set-up was capable of handling multiple Device Under Tests (DUT) and had the ability to change the angle of incidence of each DUT. The DUTs were radiated with a 66MeV proton beam while the monitoring equipment observed any errors that had occurred. The results obtained indicated that all the implemented mitigation techniques tested on the VGA system improved the system’s capability of mitigating Single Event Upsets (SEU). The most effective mitigation technique was the OR-AND Multiplexer Single Event Transient (SET) filter technique. It was thus shown that mitigation techniques are viable options to prevent SEU in a VGA controller. The permanent SEU testing set-up which was designed and manufactured and was used to conduct the experiments, proved to be a practical option for further microelectronics testing at iThemba LABS.
- Full Text:
- Date Issued: 2015
Single tree water use and water-use efficiencies of selected indigenous and introduced forest species in the southern Cape region of South Africa
- Authors: Mapeto, Tatenda
- Date: 2015
- Subjects: Irrigation efficiency -- South Africa -- Western Cape Pinus radiata -- South Africa -- Western Cape
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/11493 , vital:26932
- Description: In South Africa, the limited extent of indigenous forests accelerated the development of fast-growing introduced species plantations, on which the country is now heavily reliant for its fibre and timber products. However, the plantation forestry industry is challenged with limited freshwater resources, the need for sustainable management of introduced tree species in commercial forest production systems, and a diversity of plant ecological production factors such as soils that have to be manipulated for the purposes of increasing production capacities. Additionally, plantations are established in the limited high rainfall regions of the country and the industry’s water use has been regulated since 1972. Conversely, natural forests also provide valuable goods, however, their slow growth rates have restricted their development as commercial tree production systems. In this regard the forestry industry is continuously seeking to provide for the country’s timber and fibre needs while ensuring the provision of other ecosystem services from tree production systems. Recent developments in the forestry industry have therefore been focused on water use efficiency in current and alternative tree production systems. There is also widespread unsubstantiated belief that indigenous tree species are efficient users of water. Against this background this study sought to explore the single tree water use and water use efficiencies of introduced commercial plantation species (Pinus radiata) and that of important indigenous species (Ilex mitis, Ocotea bullata and Podocarpus latifolius) for timber and fibre production in the southern Cape region of South Africa. Single tree water use measurements were carried out for a year using the heat pulse velocity method. Growth measurements for utilisable stem wood were done on a quarterly basis for the specimen trees and growth increments over the year were determined. Single tree water use efficiency was a calculated as a function of grams of stem wood gained per litre of water transpired. Measurements of daily weather conditions and soil water content were concurrently taken during the year. The relationships between the variables that express daily climatic conditions, soil water content and daily volumes of transpired water were explored. Empirical models for the prediction of daily transpiration as a function of climate and soil water content were then developed using multiple linear regression analysis. Pinus radiata trees exhibited higher totals of volumetric transpiration than the indigenous species. The water use patterns of Pinus radiata showed higher peaks of maximum and minimum daily and seasonal water use while the indigenous species showed temperate patterns of water use throughout the year. Podocarpus latifolius attained the lowest water use efficiency in the year (0.49g/L) while Pinus radiata, Ocotea bullata and Ilex mitis had comparable water use efficiency values ranging between 1g/L to 2.50g/L. Significant positive correlations existed between climatic variables and daily sapflow volumes of the tree specimens. Daily total solar radiation showed the highest positive correlation with daily transpiration and the average value of the correlation coefficient for solar radiation and water use for all tree species was 0.70 (p < 0.001). Empirical models for predicting daily water use integrated the variables expressing plant available moisture and energy. The study enhances our understanding of single tree water use, water use efficiency, the drivers of transpiration and the applicability of such studies in developing rapid estimation techniques for water use in current and alternative South African tree production systems.
- Full Text:
- Date Issued: 2015
- Authors: Mapeto, Tatenda
- Date: 2015
- Subjects: Irrigation efficiency -- South Africa -- Western Cape Pinus radiata -- South Africa -- Western Cape
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/11493 , vital:26932
- Description: In South Africa, the limited extent of indigenous forests accelerated the development of fast-growing introduced species plantations, on which the country is now heavily reliant for its fibre and timber products. However, the plantation forestry industry is challenged with limited freshwater resources, the need for sustainable management of introduced tree species in commercial forest production systems, and a diversity of plant ecological production factors such as soils that have to be manipulated for the purposes of increasing production capacities. Additionally, plantations are established in the limited high rainfall regions of the country and the industry’s water use has been regulated since 1972. Conversely, natural forests also provide valuable goods, however, their slow growth rates have restricted their development as commercial tree production systems. In this regard the forestry industry is continuously seeking to provide for the country’s timber and fibre needs while ensuring the provision of other ecosystem services from tree production systems. Recent developments in the forestry industry have therefore been focused on water use efficiency in current and alternative tree production systems. There is also widespread unsubstantiated belief that indigenous tree species are efficient users of water. Against this background this study sought to explore the single tree water use and water use efficiencies of introduced commercial plantation species (Pinus radiata) and that of important indigenous species (Ilex mitis, Ocotea bullata and Podocarpus latifolius) for timber and fibre production in the southern Cape region of South Africa. Single tree water use measurements were carried out for a year using the heat pulse velocity method. Growth measurements for utilisable stem wood were done on a quarterly basis for the specimen trees and growth increments over the year were determined. Single tree water use efficiency was a calculated as a function of grams of stem wood gained per litre of water transpired. Measurements of daily weather conditions and soil water content were concurrently taken during the year. The relationships between the variables that express daily climatic conditions, soil water content and daily volumes of transpired water were explored. Empirical models for the prediction of daily transpiration as a function of climate and soil water content were then developed using multiple linear regression analysis. Pinus radiata trees exhibited higher totals of volumetric transpiration than the indigenous species. The water use patterns of Pinus radiata showed higher peaks of maximum and minimum daily and seasonal water use while the indigenous species showed temperate patterns of water use throughout the year. Podocarpus latifolius attained the lowest water use efficiency in the year (0.49g/L) while Pinus radiata, Ocotea bullata and Ilex mitis had comparable water use efficiency values ranging between 1g/L to 2.50g/L. Significant positive correlations existed between climatic variables and daily sapflow volumes of the tree specimens. Daily total solar radiation showed the highest positive correlation with daily transpiration and the average value of the correlation coefficient for solar radiation and water use for all tree species was 0.70 (p < 0.001). Empirical models for predicting daily water use integrated the variables expressing plant available moisture and energy. The study enhances our understanding of single tree water use, water use efficiency, the drivers of transpiration and the applicability of such studies in developing rapid estimation techniques for water use in current and alternative South African tree production systems.
- Full Text:
- Date Issued: 2015
Sitting waiting
- Authors: Thomas, Cornelius
- Date: 2015
- Type: Image
- Identifier: vital:8059 , http://hdl.handle.net/10962/d1020556
- Description: On Wednesday, 21 October 2015, Rhodes University closed in solidarity with the higher education sector as students and staff embarked on nationwide protest action against the shortage of funding in the South African higher education sector. #FeesMustFall is a national student led protest movement that began in mid-October 2015 in response to proposed increases in fees at South African universities. These images depict the peaceful march and illustrate the extent of solidarity among staff, students and community members who joined in support of the protest.
- Full Text: false
- Date Issued: 2015
- Authors: Thomas, Cornelius
- Date: 2015
- Type: Image
- Identifier: vital:8059 , http://hdl.handle.net/10962/d1020556
- Description: On Wednesday, 21 October 2015, Rhodes University closed in solidarity with the higher education sector as students and staff embarked on nationwide protest action against the shortage of funding in the South African higher education sector. #FeesMustFall is a national student led protest movement that began in mid-October 2015 in response to proposed increases in fees at South African universities. These images depict the peaceful march and illustrate the extent of solidarity among staff, students and community members who joined in support of the protest.
- Full Text: false
- Date Issued: 2015
Siyahluma: a critical health education intervention
- Kelland, Lindsay, Paphitis, Sharli A
- Authors: Kelland, Lindsay , Paphitis, Sharli A
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143638 , vital:38269 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: Recent social science research points to various menstruation-related challenges facing women in the global South - most notably for our purposes here, young school-going girls in the global South report a lack of access to (1) reliable and hygienic menstrual products with which to manage their menstruation, as well as (2) the information they need to understand the process of menstruation, how to manage menstruation and how to perceive and treat their menstruating bodies given that menstruation is surrounded by a culture of taboo and silence - menstruation is seen as dirty, impure, contaminating and, importantly, as something to be concealed from others and not spoken about, particularly in relation to male others. This lack of access to information, or in many cases, provision of false, misleading or stigmatised information has a severe negative impact on the management of menstruation for both young girls and women in the global South.
- Full Text:
- Date Issued: 2015
- Authors: Kelland, Lindsay , Paphitis, Sharli A
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143638 , vital:38269 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: Recent social science research points to various menstruation-related challenges facing women in the global South - most notably for our purposes here, young school-going girls in the global South report a lack of access to (1) reliable and hygienic menstrual products with which to manage their menstruation, as well as (2) the information they need to understand the process of menstruation, how to manage menstruation and how to perceive and treat their menstruating bodies given that menstruation is surrounded by a culture of taboo and silence - menstruation is seen as dirty, impure, contaminating and, importantly, as something to be concealed from others and not spoken about, particularly in relation to male others. This lack of access to information, or in many cases, provision of false, misleading or stigmatised information has a severe negative impact on the management of menstruation for both young girls and women in the global South.
- Full Text:
- Date Issued: 2015
Social perspectives on hydroponics production in the Nelson Mandela Metro Municipality
- Authors: Qengwa, Viwe Keith
- Date: 2015
- Subjects: Hydroponics -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/5246 , vital:20824
- Description: Despite millions of Rands being disbursed to the three hydroponic projects in the Nelson Mandela Bay Municipality by Provincial Departments, Development Agencies and NGOs, relatively little is known about the impact of these projects. There is too little evaluative research on the effectiveness of such development projects. Questions arose as to what made these projects fail and what was required for sustainability over their intended life-spans. Evaluations assess a project’s ability to be sustained by examining different aspects of sustainability, including technical soundness, skills transfer, political effect, economic viability, and institutional, organizational and management effectiveness. This study has revealed that hydroponic production is a very challenging business that requires close monitoring, intense technical knowledge, and continuous learning. Moreover it is very costly, while profit generation is quick and the market central for the sustainability of this kind of project. The findings of this study also revealed that no proper feasibility study was conducted including selection of beneficiaries, no monitoring by funders and donors, no transfer of skills and no continuous empowerment of project members. Project members also indicated that they are aware of the causes of their project closures and that they are willing to participate in hydroponics production initiatives again because of the potential that these projects have.
- Full Text:
- Date Issued: 2015
- Authors: Qengwa, Viwe Keith
- Date: 2015
- Subjects: Hydroponics -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/5246 , vital:20824
- Description: Despite millions of Rands being disbursed to the three hydroponic projects in the Nelson Mandela Bay Municipality by Provincial Departments, Development Agencies and NGOs, relatively little is known about the impact of these projects. There is too little evaluative research on the effectiveness of such development projects. Questions arose as to what made these projects fail and what was required for sustainability over their intended life-spans. Evaluations assess a project’s ability to be sustained by examining different aspects of sustainability, including technical soundness, skills transfer, political effect, economic viability, and institutional, organizational and management effectiveness. This study has revealed that hydroponic production is a very challenging business that requires close monitoring, intense technical knowledge, and continuous learning. Moreover it is very costly, while profit generation is quick and the market central for the sustainability of this kind of project. The findings of this study also revealed that no proper feasibility study was conducted including selection of beneficiaries, no monitoring by funders and donors, no transfer of skills and no continuous empowerment of project members. Project members also indicated that they are aware of the causes of their project closures and that they are willing to participate in hydroponics production initiatives again because of the potential that these projects have.
- Full Text:
- Date Issued: 2015
Social workers' experiences of the utilisation of the child support grant by beneficiaries
- Authors: Nobadula, Luyanda David
- Date: 2015
- Subjects: Child support , Child welfare
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/6334 , vital:21074
- Description: The Child Support Grant was introduced to address poverty alleviation in the sense of supplementing the provision of basic needs of children. When the grant was initiated it catered for children under the age of seven, and is currently assisting children up until 18 years of age. Even though the children are supposed to be benefitting from the grants, reports from social workers and selected research findings question whether some children do indeed receive the benefits of the grant. Previous studies have predominantly focused on the experiences of caregivers/beneficiaries. The goal of this exploratory-descriptive study was to explore and describe selected social workers’ experiences regarding the utilization of the child support grant by beneficiaries. The population comprised of social workers who have two years of experience working with families receiving the Child Support Grant and who work for the Department of Social Development and Special Programmes, Afrikaanse Christelike Vroue VerenIging, and Child Welfare South Africa in Somerset East.
- Full Text:
- Date Issued: 2015
- Authors: Nobadula, Luyanda David
- Date: 2015
- Subjects: Child support , Child welfare
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/6334 , vital:21074
- Description: The Child Support Grant was introduced to address poverty alleviation in the sense of supplementing the provision of basic needs of children. When the grant was initiated it catered for children under the age of seven, and is currently assisting children up until 18 years of age. Even though the children are supposed to be benefitting from the grants, reports from social workers and selected research findings question whether some children do indeed receive the benefits of the grant. Previous studies have predominantly focused on the experiences of caregivers/beneficiaries. The goal of this exploratory-descriptive study was to explore and describe selected social workers’ experiences regarding the utilization of the child support grant by beneficiaries. The population comprised of social workers who have two years of experience working with families receiving the Child Support Grant and who work for the Department of Social Development and Special Programmes, Afrikaanse Christelike Vroue VerenIging, and Child Welfare South Africa in Somerset East.
- Full Text:
- Date Issued: 2015
Social-ecological resilience for well-being : a critical realist case study of Boksburg Lake, South Africa
- Authors: Fox, Helen Elizabeth
- Date: 2015
- Subjects: Boksburg Lake and Wetland project , Reservoirs -- South Africa -- Boksburg , Water -- Pollution -- South Africa -- Boksburg , Human ecology -- South Africa -- Boksburg , Social learning -- South Africa -- Boksburg , Critical realism
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:6048 , http://hdl.handle.net/10962/d1017872
- Description: This thesis is based on a case study of the degraded Boksburg Lake social-ecological system and an environmental education initiative that aimed to support its transformation. This initiative aimed to involve local people in reclaiming the lake’s social and ecological value, through a process of collectively reimagining possibilities, shaping identities, gaining knowledge and developing local human agency. The focus was on social learning processes in schools and churches to explore opportunities for co-engaged reflexivity that might produce transformation. Schools and Christian churches, two institutions that reflect modern, western socialecological worldviews also have the potential to bring about change. Critical Realism was chosen as my philosophical framework as it provided the tools to explore deeper mechanisms beyond empirical reality, both influencing the degrading trajectory as well as providing possibilities for transformation. It also legitimised case study research as a means to understand more generalised processes characterising modern social-ecological systems. The choice of Critical Realism informed the scope of my primary research question: What generative mechanisms constrain and enable the development of social-ecological resilience for well-being, in the modern social-ecological system of Boksburg Lake? The following three goals were formulated to address this primary question. Goal 1: Based on a multitheoretical perspective of social-ecological literature, develop conceptual tools that have explanatory power to probe generative mechanisms operating in the Boksburg Lake social-ecological system. Goal 2: Identify generative mechanisms driving the current degradation of the Boksburg Lake social-ecological system. Goal 3: Identify learning mechanisms that support transformation for greater social-ecological resilience of the Boksburg Lake social-ecological system. By addressing the primary question and research goals I aimed to gain insights into modern global socialecological systems, the mechanisms that drive high social-ecological risk and the requirements for and possibilities of global systemic change. Drawing on a broad reading of social-ecological literature from different vantage points, tools with explanatory power were developed to probe for generative mechanisms in the Boksburg Lake social-ecological system (goal 1). The human capacity for symbolic representation is identified as an emergent property of coevolving human-ecological systems. These symbolic representations become expressed in culture and worldviews, and influence patterns of identifying, types of knowledge and forms of agency. The nature of these will determine the degree that cultural systems are embedded within ecological reality and the extent of cultural-ecological coupling. A cultural system closely coupled with ecological realities is likely to value ecological systems and manage them for their health, while less coupled cultural-ecological systems are likely to lead to the opposite. Because of their integrated nature, the extent of ecological health and value will affect the decline or sustainability of cultural-ecological systems. There are numerous examples of the learning that can take place when cultural-ecological systems are facing decline. This learning can enhance or reduce biophyllic instincts that become encoded in patterns of identifying, types of knowledge and forms of agency. This in turn affects the strength of cultural-ecological coupling and the extent that human societies co-evolve with ecological systems. , Normalising ideologies is a concept coined in the thesis to refer to symbolic representations of reality that have become integral to a social fabric and determine meaning, while maintaining the domination of the powerful. These ideologies determine patterns of identifying, knowledge and agency and are recognised as having a fundamental influence on the resilience of social-ecological systems. Four normalising ideologies are identified that promote apparent human progress at the expense of ecological integrity and social equality and thus alienation with each other and the ecological world. These are human-ecological dualism, anthropocentrism, nature is mechanised and nature is to be controlled. There are also a number of ideologies promoting connectedness with the ecological world that, if they became normalised, would support greater social-ecological resilience for well-being. Generative mechanisms driving the current degradation of the Boksburg Lake socialecological system were identified (goal 2). Drawing on critical methodology, the main method adopted was document analysis of the Boksburg Advertiser archives, Boksburg’s local newspaper. Four generative mechanisms are recognised as most influential. Two of these have been named hegemonic symbolic systems. The primary symbolic system consists of the four normalising ideologies, mentioned above, that promote human progress at the expense of ecological health. The secondary, more explicit symbolic system, built on this, consists of the following normative ideologies: economic growth is imperative, unrestrained development is promoted, competition is the necessary means and consumerism is the good life. These two symbolic systems have had causal influence on the systematic erosion of ecological processes and biological diversity that has occurred in Boksburg, with the consequent undermining of social-ecological resilience for well-being. The third mechanism that constrains resilience is the power dynamics that have shaped Boksburg’s economic history and social-ecological system. This has resulted in a society built on inequality and injustice with all its associated social and environmental ills, expressed as externalities. The fourth mechanism resides in Boksburg’s political and municipal dynamics. These structures are not designed to tackle complex social-ecological problems and they hold considerable agential power, yet seem dysfunctional at present. Learning mechanisms that support transformation for greater social-ecological resilience of the Boksburg Lake social-ecological system were identified (goal 3). By adopting the role of a reflexive practitioner, supported by action research, case study and interpretivist methodologies, data on the empirical manifestations of the environmental educational initiative were collected. Methods included semistructured interviews, focus groups, document analysis and participant observation. Findings indicate that schools and churches are important institutions that can positively influence patterns of identifying, knowledge about and agency for Boksburg Lake and can thus play a role in transforming hegemonic normalising ideologies. Important learning mechanisms identified included: Learning reflexively together within communities of practice that provide opportunities for active rather than passive learning; involving the youth as they are a group of people with notable enthusiasm, vision, energy and motivation; learning through information acquisition, investigation, action and deliberation; learning about abstract concepts and theoretical knowledge but embedding this in local realities; and learning that provides reference markers for how things can be different.
- Full Text:
- Date Issued: 2015
- Authors: Fox, Helen Elizabeth
- Date: 2015
- Subjects: Boksburg Lake and Wetland project , Reservoirs -- South Africa -- Boksburg , Water -- Pollution -- South Africa -- Boksburg , Human ecology -- South Africa -- Boksburg , Social learning -- South Africa -- Boksburg , Critical realism
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:6048 , http://hdl.handle.net/10962/d1017872
- Description: This thesis is based on a case study of the degraded Boksburg Lake social-ecological system and an environmental education initiative that aimed to support its transformation. This initiative aimed to involve local people in reclaiming the lake’s social and ecological value, through a process of collectively reimagining possibilities, shaping identities, gaining knowledge and developing local human agency. The focus was on social learning processes in schools and churches to explore opportunities for co-engaged reflexivity that might produce transformation. Schools and Christian churches, two institutions that reflect modern, western socialecological worldviews also have the potential to bring about change. Critical Realism was chosen as my philosophical framework as it provided the tools to explore deeper mechanisms beyond empirical reality, both influencing the degrading trajectory as well as providing possibilities for transformation. It also legitimised case study research as a means to understand more generalised processes characterising modern social-ecological systems. The choice of Critical Realism informed the scope of my primary research question: What generative mechanisms constrain and enable the development of social-ecological resilience for well-being, in the modern social-ecological system of Boksburg Lake? The following three goals were formulated to address this primary question. Goal 1: Based on a multitheoretical perspective of social-ecological literature, develop conceptual tools that have explanatory power to probe generative mechanisms operating in the Boksburg Lake social-ecological system. Goal 2: Identify generative mechanisms driving the current degradation of the Boksburg Lake social-ecological system. Goal 3: Identify learning mechanisms that support transformation for greater social-ecological resilience of the Boksburg Lake social-ecological system. By addressing the primary question and research goals I aimed to gain insights into modern global socialecological systems, the mechanisms that drive high social-ecological risk and the requirements for and possibilities of global systemic change. Drawing on a broad reading of social-ecological literature from different vantage points, tools with explanatory power were developed to probe for generative mechanisms in the Boksburg Lake social-ecological system (goal 1). The human capacity for symbolic representation is identified as an emergent property of coevolving human-ecological systems. These symbolic representations become expressed in culture and worldviews, and influence patterns of identifying, types of knowledge and forms of agency. The nature of these will determine the degree that cultural systems are embedded within ecological reality and the extent of cultural-ecological coupling. A cultural system closely coupled with ecological realities is likely to value ecological systems and manage them for their health, while less coupled cultural-ecological systems are likely to lead to the opposite. Because of their integrated nature, the extent of ecological health and value will affect the decline or sustainability of cultural-ecological systems. There are numerous examples of the learning that can take place when cultural-ecological systems are facing decline. This learning can enhance or reduce biophyllic instincts that become encoded in patterns of identifying, types of knowledge and forms of agency. This in turn affects the strength of cultural-ecological coupling and the extent that human societies co-evolve with ecological systems. , Normalising ideologies is a concept coined in the thesis to refer to symbolic representations of reality that have become integral to a social fabric and determine meaning, while maintaining the domination of the powerful. These ideologies determine patterns of identifying, knowledge and agency and are recognised as having a fundamental influence on the resilience of social-ecological systems. Four normalising ideologies are identified that promote apparent human progress at the expense of ecological integrity and social equality and thus alienation with each other and the ecological world. These are human-ecological dualism, anthropocentrism, nature is mechanised and nature is to be controlled. There are also a number of ideologies promoting connectedness with the ecological world that, if they became normalised, would support greater social-ecological resilience for well-being. Generative mechanisms driving the current degradation of the Boksburg Lake socialecological system were identified (goal 2). Drawing on critical methodology, the main method adopted was document analysis of the Boksburg Advertiser archives, Boksburg’s local newspaper. Four generative mechanisms are recognised as most influential. Two of these have been named hegemonic symbolic systems. The primary symbolic system consists of the four normalising ideologies, mentioned above, that promote human progress at the expense of ecological health. The secondary, more explicit symbolic system, built on this, consists of the following normative ideologies: economic growth is imperative, unrestrained development is promoted, competition is the necessary means and consumerism is the good life. These two symbolic systems have had causal influence on the systematic erosion of ecological processes and biological diversity that has occurred in Boksburg, with the consequent undermining of social-ecological resilience for well-being. The third mechanism that constrains resilience is the power dynamics that have shaped Boksburg’s economic history and social-ecological system. This has resulted in a society built on inequality and injustice with all its associated social and environmental ills, expressed as externalities. The fourth mechanism resides in Boksburg’s political and municipal dynamics. These structures are not designed to tackle complex social-ecological problems and they hold considerable agential power, yet seem dysfunctional at present. Learning mechanisms that support transformation for greater social-ecological resilience of the Boksburg Lake social-ecological system were identified (goal 3). By adopting the role of a reflexive practitioner, supported by action research, case study and interpretivist methodologies, data on the empirical manifestations of the environmental educational initiative were collected. Methods included semistructured interviews, focus groups, document analysis and participant observation. Findings indicate that schools and churches are important institutions that can positively influence patterns of identifying, knowledge about and agency for Boksburg Lake and can thus play a role in transforming hegemonic normalising ideologies. Important learning mechanisms identified included: Learning reflexively together within communities of practice that provide opportunities for active rather than passive learning; involving the youth as they are a group of people with notable enthusiasm, vision, energy and motivation; learning through information acquisition, investigation, action and deliberation; learning about abstract concepts and theoretical knowledge but embedding this in local realities; and learning that provides reference markers for how things can be different.
- Full Text:
- Date Issued: 2015
Socio-economic factors influencing apiculture in the Eastern Cape province, South Africa
- Authors: Peter, Luntulwandile
- Date: 2015
- Subjects: Bee culture -- South Africa -- Eastern Cape Honey -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/15321 , vital:40362
- Description: The aim of this study was to assess socio-economic factors influencing apiculture in the Eastern Cape Province. In addition, production costs and profitability of beekeeping were determined, and opportunities and challenges to beekeeping were identified. The data was generated from 58 individual interviews using pre-tested structured questionnaires and checklists. This was supplemented by secondary data collected from different published and unpublished sources. Gross margin analysis was employed to examine the income contribution of honey production to household income, and a Linear Regression Model was used to identify the determinants of honey production. Of the twelve variables included in the regression model, only six were found to be statistically significant. These were gender of the beekeeper, access to credit, availability of labour, price of honey, distance to the market, and number of bee colonies owned. On average, each beekeeper owned and operated 35 bee colonies, with an average production of 9 kg of honey per colony per annum; the latter is well beyond a potential production of 35 kg per colony per annum. Beekeeping contributed an average of R12 231.80 per beekeeping household per annum. Except for the honey, no other bee products were produced and marketed. The beekeepers could access the market (retailers and consumers) readily and efficiently; the latter having been determined through calculation and analysing marketing margins. The major constraints to production identified and prioritised by beekeepers in the study area were drought, pests and insects, the shortage of bee forage, and the lack of adequate beekeeping skills. Based on the study results, interventions required to raise the marketable supply of honey produce are recommended.
- Full Text:
- Date Issued: 2015
- Authors: Peter, Luntulwandile
- Date: 2015
- Subjects: Bee culture -- South Africa -- Eastern Cape Honey -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/15321 , vital:40362
- Description: The aim of this study was to assess socio-economic factors influencing apiculture in the Eastern Cape Province. In addition, production costs and profitability of beekeeping were determined, and opportunities and challenges to beekeeping were identified. The data was generated from 58 individual interviews using pre-tested structured questionnaires and checklists. This was supplemented by secondary data collected from different published and unpublished sources. Gross margin analysis was employed to examine the income contribution of honey production to household income, and a Linear Regression Model was used to identify the determinants of honey production. Of the twelve variables included in the regression model, only six were found to be statistically significant. These were gender of the beekeeper, access to credit, availability of labour, price of honey, distance to the market, and number of bee colonies owned. On average, each beekeeper owned and operated 35 bee colonies, with an average production of 9 kg of honey per colony per annum; the latter is well beyond a potential production of 35 kg per colony per annum. Beekeeping contributed an average of R12 231.80 per beekeeping household per annum. Except for the honey, no other bee products were produced and marketed. The beekeepers could access the market (retailers and consumers) readily and efficiently; the latter having been determined through calculation and analysing marketing margins. The major constraints to production identified and prioritised by beekeepers in the study area were drought, pests and insects, the shortage of bee forage, and the lack of adequate beekeeping skills. Based on the study results, interventions required to raise the marketable supply of honey produce are recommended.
- Full Text:
- Date Issued: 2015
Socio-economic factors influencing the adoption of in-field rainwater harvesting technololgy for enhancing household food security by small holder farmers in the Nkonkobe Municipality, Eastern Cape Province
- Shange, Nomfundo Sinethemba Queen
- Authors: Shange, Nomfundo Sinethemba Queen
- Date: 2015
- Subjects: Farms, Small -- South Africa -- Eastern Cape , Water harvesting -- South Africa -- Eastern Cape , Sustainable agriculture -- South Africa -- Eastern Cape , Water resources development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Agricultural Economics)
- Identifier: http://hdl.handle.net/10353/734 , vital:26492 , Farms, Small -- South Africa -- Eastern Cape , Water harvesting -- South Africa -- Eastern Cape , Sustainable agriculture -- South Africa -- Eastern Cape , Water resources development -- South Africa -- Eastern Cape
- Description: Infield rainwater harvesting (IRWH) technology has been used in arid and semi-arid parts of the world and promising results have been achieved in terms of increasing yield. The main aim of this study was to identify socio-economic factors determining the adoption of IRWH technology for enhancing household food security by smallholder farmers. The specific objectives were to assess the level of adoption of IRWH technology using descriptive statistics (mean, frequency and percentages). To determine socio-economic factors influencing adoption of IRWH technology, the binary logistic regression mode l was used. To determine whether adopters of IRWH technology are more food secure than non-adopters, the Household Dietary Diversity Score (HDDS) was used as a measure for household food security. For the same objective, to determine socio-economic factors that influence household food security, the binary logistic regression model was also used and adoption of IRWH technology became an independent variable. The study was conducted in Khayalethu, Guquka and Krwakrwa villages in Nkonkobe Municipality in the Eastern Cape Province (EC). The unit of analysis was the individual smallholder farmers practicing agriculture. The availability (accidental) and snowball sampling techniques were used to select 34, 23, 63 respondents from Khayalethu, Guquka and Krwakrwa villages respectively. Since they are non-random, these sampling methods are problematic because of sampling errors. Overall, a sample size of 120 smallholder farmers was targeted for the interviews. Primary and secondary data collected was coded and analysed using statistical package for social sciences (SPSS) version 21. Results were presented using graphs, pie charts and tables (including cross-tables). The descriptive results showed that adoption status of IRWH technology was low in these areas, with 79% not adopting the technology. Food insecurity was high amongst the non-adopters with 86%. On the basis of descriptive analysis it can be concluded that any change in each one of the significant variables can significantly influence the probability of adopting IRWH technology and household food security. The results from the logistic regression model for the incidence of adoption revealed that 6 out of 16 variables were significant, three at 1% (access to extension services, access to information and farmers’ perception towards the IRWH technology); one at 5% (access to market) and two at 10% (access to hired labour and farm income). For the incidence of household food security, out of 17 variables, 6 were significant, three at 1% (adoption of the IRWH technology, access to extension services and farmers’ perception towards the IRWH technology); two at 5% (access to hired labour and household income) and one at 10% (household size). The empirical findings of this study indicate that there are socio-economic factors influencing adoption of IRWH technology and household food security amongst smallholder farmers. This study recommends that the government should provide extension officers and research stations with the capacity, support and physical means to expose smallholder farmers to the IRWH technology through demonstrations and trainings. The government can also introduce agricultural finance institutions in rural areas to assist the rural smallholder farmers to increase their access to credit. Further, it is recommended that smallholder farmers can expand to the communal croplands in order to gain more land size and work as a co-operative or as an association to ease labour constraints.
- Full Text:
- Date Issued: 2015
- Authors: Shange, Nomfundo Sinethemba Queen
- Date: 2015
- Subjects: Farms, Small -- South Africa -- Eastern Cape , Water harvesting -- South Africa -- Eastern Cape , Sustainable agriculture -- South Africa -- Eastern Cape , Water resources development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Agricultural Economics)
- Identifier: http://hdl.handle.net/10353/734 , vital:26492 , Farms, Small -- South Africa -- Eastern Cape , Water harvesting -- South Africa -- Eastern Cape , Sustainable agriculture -- South Africa -- Eastern Cape , Water resources development -- South Africa -- Eastern Cape
- Description: Infield rainwater harvesting (IRWH) technology has been used in arid and semi-arid parts of the world and promising results have been achieved in terms of increasing yield. The main aim of this study was to identify socio-economic factors determining the adoption of IRWH technology for enhancing household food security by smallholder farmers. The specific objectives were to assess the level of adoption of IRWH technology using descriptive statistics (mean, frequency and percentages). To determine socio-economic factors influencing adoption of IRWH technology, the binary logistic regression mode l was used. To determine whether adopters of IRWH technology are more food secure than non-adopters, the Household Dietary Diversity Score (HDDS) was used as a measure for household food security. For the same objective, to determine socio-economic factors that influence household food security, the binary logistic regression model was also used and adoption of IRWH technology became an independent variable. The study was conducted in Khayalethu, Guquka and Krwakrwa villages in Nkonkobe Municipality in the Eastern Cape Province (EC). The unit of analysis was the individual smallholder farmers practicing agriculture. The availability (accidental) and snowball sampling techniques were used to select 34, 23, 63 respondents from Khayalethu, Guquka and Krwakrwa villages respectively. Since they are non-random, these sampling methods are problematic because of sampling errors. Overall, a sample size of 120 smallholder farmers was targeted for the interviews. Primary and secondary data collected was coded and analysed using statistical package for social sciences (SPSS) version 21. Results were presented using graphs, pie charts and tables (including cross-tables). The descriptive results showed that adoption status of IRWH technology was low in these areas, with 79% not adopting the technology. Food insecurity was high amongst the non-adopters with 86%. On the basis of descriptive analysis it can be concluded that any change in each one of the significant variables can significantly influence the probability of adopting IRWH technology and household food security. The results from the logistic regression model for the incidence of adoption revealed that 6 out of 16 variables were significant, three at 1% (access to extension services, access to information and farmers’ perception towards the IRWH technology); one at 5% (access to market) and two at 10% (access to hired labour and farm income). For the incidence of household food security, out of 17 variables, 6 were significant, three at 1% (adoption of the IRWH technology, access to extension services and farmers’ perception towards the IRWH technology); two at 5% (access to hired labour and household income) and one at 10% (household size). The empirical findings of this study indicate that there are socio-economic factors influencing adoption of IRWH technology and household food security amongst smallholder farmers. This study recommends that the government should provide extension officers and research stations with the capacity, support and physical means to expose smallholder farmers to the IRWH technology through demonstrations and trainings. The government can also introduce agricultural finance institutions in rural areas to assist the rural smallholder farmers to increase their access to credit. Further, it is recommended that smallholder farmers can expand to the communal croplands in order to gain more land size and work as a co-operative or as an association to ease labour constraints.
- Full Text:
- Date Issued: 2015
Socio-spatial dynamics in the use of wild natural resources: Evidence from six rapidly growing medium-sized cities in Africa
- Schlesinger, Johannes, Drescher, Axel W, Shackleton, Charlie M
- Authors: Schlesinger, Johannes , Drescher, Axel W , Shackleton, Charlie M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180897 , vital:43668 , xlink:href="https://doi.org/10.1016/j.apgeog.2014.11.013"
- Description: Increasing urbanisation in sub-Saharan Africa transforms spatial configurations in and around towns and cities. At the same time wild natural resources play an important role in African livelihoods. Yet, little is known about the impact of urbanisation on the socio-spatial dynamics of the use of wild natural resources. Here we examined the importance of these resources for livelihoods, differences in their use between different locations along the urban-rural continuum, and the respective temporal dynamics. A total of 1158 households were interviewed in six medium-sized cities distributed across five African countries using a standardised questionnaire supplemented by expert interviews and spatial analyses employing Geographic Information Systems. Overall, even though periurban and rural households were more likely to use wild natural resources than those in the urban areas, the use of these resources was generally high along the entire urban-rural continuum. Despite the increasing urban pressure on these resources, they remain an integral part for most households, not only for those lacking access to productive resources, but also for those with a higher standard of living. This trend was found across all study towns, despite the marked differences in their respective socio-spatial as well as environmental settings.
- Full Text:
- Date Issued: 2015
- Authors: Schlesinger, Johannes , Drescher, Axel W , Shackleton, Charlie M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180897 , vital:43668 , xlink:href="https://doi.org/10.1016/j.apgeog.2014.11.013"
- Description: Increasing urbanisation in sub-Saharan Africa transforms spatial configurations in and around towns and cities. At the same time wild natural resources play an important role in African livelihoods. Yet, little is known about the impact of urbanisation on the socio-spatial dynamics of the use of wild natural resources. Here we examined the importance of these resources for livelihoods, differences in their use between different locations along the urban-rural continuum, and the respective temporal dynamics. A total of 1158 households were interviewed in six medium-sized cities distributed across five African countries using a standardised questionnaire supplemented by expert interviews and spatial analyses employing Geographic Information Systems. Overall, even though periurban and rural households were more likely to use wild natural resources than those in the urban areas, the use of these resources was generally high along the entire urban-rural continuum. Despite the increasing urban pressure on these resources, they remain an integral part for most households, not only for those lacking access to productive resources, but also for those with a higher standard of living. This trend was found across all study towns, despite the marked differences in their respective socio-spatial as well as environmental settings.
- Full Text:
- Date Issued: 2015
Sources of change in the money stock
- Smith, Robert Ayreton Bailey
- Authors: Smith, Robert Ayreton Bailey
- Date: 2015
- Subjects: Money supply -- South Africa , Money -- South Africa , Banks and banking, Central -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1118 , http://hdl.handle.net/10962/d1017543
- Description: This research provides an historical, theoretical and practical appraisal of exogenous and endogenous money and money creation, with South Africa as the focus of the practical investigation. Monetary theory of recent decades can be categorised as belonging to one of two distinct paradigms: mainstream (neoclassical) or post Keynesian. The mainstream (orthodox) view presents a Euclidian or Cartesian, ergodic, deductive, and axiomatic theoretical interpretation of the world. This is perpetuated through the continued, and inaccurate, depiction in academia of exogenous money creation, the money multiplier concept, asset transformation by banks, imposed alterations to the money stock by central banks and long-run closed system equilibrium models (and associated homogeneity, and long term behavioural assumptions). In the real world, economic agents, structures, institutions and their interrelations are perpetually evolving. The post Keynesian paradigm provides the theoretical framework within which to understand such a world. Unfortunately the necessity for a multiplicity of methods and methodology makes it a paradigm that is currently prohibitively complex, preventing simple exposition. Money creation should, both historically, and according to the analysis conducted, be defined according to the actual source of change in the money stock, that is, credit extension. In a nonergodic world, changes in the stock of money take on a causal role with regard the initiation of productive processes, and thus influence future economic conditions. The simple, although powerful, technique of balance sheet analysis conducted herein provides a detailed method of identification of causal changes in money stock. Within the context of the institutional and structural environment, it clearly demonstrates the residual nature of money m modern economies. This research serves to emphasise the importance of monetary matters for economic management, as well as the important difference between the money creation process and the residual deposit securities. It serves also to discourage the perpetuation of fallacies of money creation, and capabilities of monetary authorities. In South Africa, as in most countries, the central bank can influence the conditions under which borrowers and banks mutually create money, but do not themselves create or distribute money beyond the facilitation of credit extension by banks
- Full Text:
- Date Issued: 2015
- Authors: Smith, Robert Ayreton Bailey
- Date: 2015
- Subjects: Money supply -- South Africa , Money -- South Africa , Banks and banking, Central -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1118 , http://hdl.handle.net/10962/d1017543
- Description: This research provides an historical, theoretical and practical appraisal of exogenous and endogenous money and money creation, with South Africa as the focus of the practical investigation. Monetary theory of recent decades can be categorised as belonging to one of two distinct paradigms: mainstream (neoclassical) or post Keynesian. The mainstream (orthodox) view presents a Euclidian or Cartesian, ergodic, deductive, and axiomatic theoretical interpretation of the world. This is perpetuated through the continued, and inaccurate, depiction in academia of exogenous money creation, the money multiplier concept, asset transformation by banks, imposed alterations to the money stock by central banks and long-run closed system equilibrium models (and associated homogeneity, and long term behavioural assumptions). In the real world, economic agents, structures, institutions and their interrelations are perpetually evolving. The post Keynesian paradigm provides the theoretical framework within which to understand such a world. Unfortunately the necessity for a multiplicity of methods and methodology makes it a paradigm that is currently prohibitively complex, preventing simple exposition. Money creation should, both historically, and according to the analysis conducted, be defined according to the actual source of change in the money stock, that is, credit extension. In a nonergodic world, changes in the stock of money take on a causal role with regard the initiation of productive processes, and thus influence future economic conditions. The simple, although powerful, technique of balance sheet analysis conducted herein provides a detailed method of identification of causal changes in money stock. Within the context of the institutional and structural environment, it clearly demonstrates the residual nature of money m modern economies. This research serves to emphasise the importance of monetary matters for economic management, as well as the important difference between the money creation process and the residual deposit securities. It serves also to discourage the perpetuation of fallacies of money creation, and capabilities of monetary authorities. In South Africa, as in most countries, the central bank can influence the conditions under which borrowers and banks mutually create money, but do not themselves create or distribute money beyond the facilitation of credit extension by banks
- Full Text:
- Date Issued: 2015
South African crime fiction: sleuthing the State post-1994, African Identities
- Authors: Naidu, Samantha
- Date: 2015
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10962/53912 , vital:26357 , http://dx.doi.org/10.1080/14725843.2015.1009621 , https://orcid.org/0000-0001-9456-8657
- Description: In this essay we demonstrate how the burgeoning field of South African crime fiction has responded to the birth and development of a democratic, post-apartheid South African state. First, an overview of South African crime fiction in the last 20 years is presented. Then the essay presents an argument for South African crime fiction to be regarded as the ‘new political novel’, based on its capacity for socio-political analysis. We use Deon Meyer, arguably South Africa’s most popular and successful crime fiction author, as an exemplar for our argument. In the following section, the genresnob debate and the resurgence of such terms as ‘lowbrow’ and ‘highbrow’ are considered in relation to crime fiction and the role it plays in the socio-cultural arena of post-apartheid South Africa. We conclude with a comment on the significance of popular literary genres for democracy and critical discourses which underpin that democracy. The essay shows that crime fiction is a strong tool for socio-political analysis in a democratic South Africa, because it promotes critical discourse in society, despite being deemed lowbrow or ideologically ambiguous.
- Full Text: false
- Date Issued: 2015
- Authors: Naidu, Samantha
- Date: 2015
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10962/53912 , vital:26357 , http://dx.doi.org/10.1080/14725843.2015.1009621 , https://orcid.org/0000-0001-9456-8657
- Description: In this essay we demonstrate how the burgeoning field of South African crime fiction has responded to the birth and development of a democratic, post-apartheid South African state. First, an overview of South African crime fiction in the last 20 years is presented. Then the essay presents an argument for South African crime fiction to be regarded as the ‘new political novel’, based on its capacity for socio-political analysis. We use Deon Meyer, arguably South Africa’s most popular and successful crime fiction author, as an exemplar for our argument. In the following section, the genresnob debate and the resurgence of such terms as ‘lowbrow’ and ‘highbrow’ are considered in relation to crime fiction and the role it plays in the socio-cultural arena of post-apartheid South Africa. We conclude with a comment on the significance of popular literary genres for democracy and critical discourses which underpin that democracy. The essay shows that crime fiction is a strong tool for socio-political analysis in a democratic South Africa, because it promotes critical discourse in society, despite being deemed lowbrow or ideologically ambiguous.
- Full Text: false
- Date Issued: 2015
Spatial and temporal variability in water quality characteristics of the Swartkops Estuary
- Authors: Pretorius, Liaan Marié
- Date: 2015
- Subjects: Estuarine ecology -- South Africa -- Eastern Cape , Hydrology -- South Africa -- Eastern Cape , Water quality -- South Africa -- Swarkops River Estuary
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/4176 , vital:20563
- Description: Water quality characteristics of the heavily urbanised and industrialised Swartkops River catchment in the Eastern Cape has been the focus of several studies since the 1970s. Overloaded and poorly maintained wastewater treatment works (WWTW), polluted stormwater runoff and solid waste have had a negative impact on the water quality status of the Swartkops River and estuary. Past studies have revealed that a distinct relationship exists between land use activities and the water quality of the Swartkops Estuary, which in turn has raised concerns pertaining to the ecological, economic, recreational, and cultural value of the estuaryThe Swartkops Estuary has a Present Ecological State (PES) of Category D(1) and a Recommended Ecological Category (REC)(2) of a C (Van Niekerk et al., 2014). It is known that effective management of anthropogenic impacts on coastal systems requires a thorough understanding of the system’s biological responses to wastewater discharges and to hydrologic changes. For this reason, the objective of this study was to determine the current water quality status of the Swartkops Estuary, and to gain greater insight into factors controlling eutrophication. This was important as outdated water quality information was used in the Swartkops Integrated Environmental Management Plan (Enviro-Fish Africa, 2011) due to a lack of current data. To determine the current water quality status of the Swartkops Estuary the present study investigated spatial and temporal variability in physico-chemical parameters, nutrients, phytoplankton biomass and community composition, faecal bacteria, and “where possible” related this to historical water quality data. In general, points of entry into the estuary were investigated for their impact on nutrient enrichment and the bacteriological status of the estuary. Water quality surveys were completed in September 2012, November 2012, February 2013, May 2013 and August 2013The present study found evidence to suggest that water is not flushed as efficiently from the estuary as was previously the case, and that the natural hydrology of the estuary has been modified. These changes appear to be the effect of large volumes of wastewater discharges from the wastewater treatment works (WWTW), which has led to the additional stresses of increased vertical stratification and reduced vertical mixing. A build-up of dissolved inorganic nutrients has given rise to persistent eutrophic conditions and phytoplankton blooms occurring from the middle reaches to the tidal limit of the estuary. These findings were associated with a generally well oxygenated estuary; however, bottom water hypoxic conditions were recorded in the upper reaches of the estuary on two occasions and were generally associated with bloom.forming flagellates. Elevated concentrations of inorganic nutrients stimulated phytoplankton to attain high biomass ranging from 0 to 248 g l-1 (31.8 6.56 g l-1). All nutrients displayed positive linear gradients from the mouth to the tidal limit, showed significant (p < 0.05) temporal and spatial variability, and were significantly (p < 0.05) correlated with phytoplankton biomass. Phytoplankton blooms (> 10 000 cells ml-1) of several different groups were recorded from the middle reaches of the estuary to the tidal limit. Diatoms were the dominant group during increased freshwater inflow (at mean daily flow rate of 2.14 m3 s-1) and low DIP levels, whereas flagellates were generally the dominant group during reduced flow and under higher nutrient levels. Although the different tidal stages had no effect on phytoplankton biomass per se, it did support co-existance between phytoplankton groups. This was noted during the spring ebb tide in September 2012 (i.e. flagellates, diatoms and dinoflagellate) and in February 2013 (i.e. dinoflagellates, diatoms and chlorophytes). Phytoplankton blooms have become persistent in the middle to upper reaches of the estuary where chlorophyll-a was > 20 µg l-1 and cell density exceeded 10 000 cells ml-1; a situation not reported in previous studies. The Motherwell Canal was and still is the main source of nitrogen (generally in the form of ammonium) to the estuary, whereas the Swartkops River is still the primary source of phosphorus to the estuary. Since the stormwater canal services the large residential area of Motherwell where leaks in the sewer system, the dumping of night soil buckets, and faulty pumps are often reported, polluted discharges from the Motherwell Canal can enter the canal at any given point. In contrast to the canal, DIP loading from the Swartkops River to the estuary generally occurred under conditions of low flow, whereas nitrogen showed no apparent relationship. Faecal bacteria originating from the Motherwell Canal had the most profound effect on the bacteriological status in the middle reaches of the estuary, whereas the Swartkops River had an intermediate effect due to bacteria die-offs occurring between the point of release from the WWTW to the riverine reaches and the tidal limit of the estuary. Nevertheless, Escherichia coli and enterococci levels are still high, especially in the summer months rendering the estuary unsafe for recreation during this season. Historical data on trace metals in the water column were limited and thus observations from the present study could not be concluded with much confidence. However, preliminary data suggest that levels of copper, zinc, iron and cadmium have increased by at least 90% in the estuary, at the tidal limit of the estuary and in the Markman and Motherwell canals. High inputs of nutrients, trace metals and faecal bacteria to the estuary from land-use activities indicate the necessity for remedial actions with the main objective being to conserve and protect the estuary’s recreational, ecological and economic functions.
- Full Text:
- Date Issued: 2015
- Authors: Pretorius, Liaan Marié
- Date: 2015
- Subjects: Estuarine ecology -- South Africa -- Eastern Cape , Hydrology -- South Africa -- Eastern Cape , Water quality -- South Africa -- Swarkops River Estuary
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/4176 , vital:20563
- Description: Water quality characteristics of the heavily urbanised and industrialised Swartkops River catchment in the Eastern Cape has been the focus of several studies since the 1970s. Overloaded and poorly maintained wastewater treatment works (WWTW), polluted stormwater runoff and solid waste have had a negative impact on the water quality status of the Swartkops River and estuary. Past studies have revealed that a distinct relationship exists between land use activities and the water quality of the Swartkops Estuary, which in turn has raised concerns pertaining to the ecological, economic, recreational, and cultural value of the estuaryThe Swartkops Estuary has a Present Ecological State (PES) of Category D(1) and a Recommended Ecological Category (REC)(2) of a C (Van Niekerk et al., 2014). It is known that effective management of anthropogenic impacts on coastal systems requires a thorough understanding of the system’s biological responses to wastewater discharges and to hydrologic changes. For this reason, the objective of this study was to determine the current water quality status of the Swartkops Estuary, and to gain greater insight into factors controlling eutrophication. This was important as outdated water quality information was used in the Swartkops Integrated Environmental Management Plan (Enviro-Fish Africa, 2011) due to a lack of current data. To determine the current water quality status of the Swartkops Estuary the present study investigated spatial and temporal variability in physico-chemical parameters, nutrients, phytoplankton biomass and community composition, faecal bacteria, and “where possible” related this to historical water quality data. In general, points of entry into the estuary were investigated for their impact on nutrient enrichment and the bacteriological status of the estuary. Water quality surveys were completed in September 2012, November 2012, February 2013, May 2013 and August 2013The present study found evidence to suggest that water is not flushed as efficiently from the estuary as was previously the case, and that the natural hydrology of the estuary has been modified. These changes appear to be the effect of large volumes of wastewater discharges from the wastewater treatment works (WWTW), which has led to the additional stresses of increased vertical stratification and reduced vertical mixing. A build-up of dissolved inorganic nutrients has given rise to persistent eutrophic conditions and phytoplankton blooms occurring from the middle reaches to the tidal limit of the estuary. These findings were associated with a generally well oxygenated estuary; however, bottom water hypoxic conditions were recorded in the upper reaches of the estuary on two occasions and were generally associated with bloom.forming flagellates. Elevated concentrations of inorganic nutrients stimulated phytoplankton to attain high biomass ranging from 0 to 248 g l-1 (31.8 6.56 g l-1). All nutrients displayed positive linear gradients from the mouth to the tidal limit, showed significant (p < 0.05) temporal and spatial variability, and were significantly (p < 0.05) correlated with phytoplankton biomass. Phytoplankton blooms (> 10 000 cells ml-1) of several different groups were recorded from the middle reaches of the estuary to the tidal limit. Diatoms were the dominant group during increased freshwater inflow (at mean daily flow rate of 2.14 m3 s-1) and low DIP levels, whereas flagellates were generally the dominant group during reduced flow and under higher nutrient levels. Although the different tidal stages had no effect on phytoplankton biomass per se, it did support co-existance between phytoplankton groups. This was noted during the spring ebb tide in September 2012 (i.e. flagellates, diatoms and dinoflagellate) and in February 2013 (i.e. dinoflagellates, diatoms and chlorophytes). Phytoplankton blooms have become persistent in the middle to upper reaches of the estuary where chlorophyll-a was > 20 µg l-1 and cell density exceeded 10 000 cells ml-1; a situation not reported in previous studies. The Motherwell Canal was and still is the main source of nitrogen (generally in the form of ammonium) to the estuary, whereas the Swartkops River is still the primary source of phosphorus to the estuary. Since the stormwater canal services the large residential area of Motherwell where leaks in the sewer system, the dumping of night soil buckets, and faulty pumps are often reported, polluted discharges from the Motherwell Canal can enter the canal at any given point. In contrast to the canal, DIP loading from the Swartkops River to the estuary generally occurred under conditions of low flow, whereas nitrogen showed no apparent relationship. Faecal bacteria originating from the Motherwell Canal had the most profound effect on the bacteriological status in the middle reaches of the estuary, whereas the Swartkops River had an intermediate effect due to bacteria die-offs occurring between the point of release from the WWTW to the riverine reaches and the tidal limit of the estuary. Nevertheless, Escherichia coli and enterococci levels are still high, especially in the summer months rendering the estuary unsafe for recreation during this season. Historical data on trace metals in the water column were limited and thus observations from the present study could not be concluded with much confidence. However, preliminary data suggest that levels of copper, zinc, iron and cadmium have increased by at least 90% in the estuary, at the tidal limit of the estuary and in the Markman and Motherwell canals. High inputs of nutrients, trace metals and faecal bacteria to the estuary from land-use activities indicate the necessity for remedial actions with the main objective being to conserve and protect the estuary’s recreational, ecological and economic functions.
- Full Text:
- Date Issued: 2015
Spatial and temporal variations in trophic connectivity within an estuarine environment : benthic-pelagic and terrestrial-aquatic linkages via invertebrates and fishes
- Authors: Bergamino Roman, Leandro
- Date: 2015
- Subjects: Estuarine ecology -- South Africa , Marine invertebrates -- South Africa -- Ecology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5921 , http://hdl.handle.net/10962/d1017799
- Description: Estuarine ecosystems are among the most biologically productive areas and they provide important ecosystem services such as erosion control, habitat and refugia for several species. These environments are characterized by the presence of a variety of organic matter sources due to their transitional position between rivers and the sea. The biotic compositions can undergo spatial and seasonal changes along the estuary due to the spatial and temporal fluctuations of environmental factors such as salinity, temperature and seston loads. Therefore, the different combinations of biotic and abiotic factors make each estuary a unique ecosystem. Because of this spatial and temporal complexity, the understanding of estuarine food web structure and which factors affect the trophic relationships within the ecosystem through space and time represent challenging tasks. Furthermore, estuaries are under an increasing number of anthropogenic perturbations because of the growing concentration of human populations in coastal areas. Knowledge of ecosystem structure and functioning is essential for effective conservation and management planning of coastal areas.In this dissertation, I combine the utilization of biological tracers to examine spatial and temporal variability in the food web structure within a small temperate and microtidal estuary located in South Africa. To this end, fatty acid profiles and stable isotope signatures were measured in several primary organic matter sources and consumers (including zooplankton, fishes and benthic invertebrates) during four consecutive seasons and in three different estuarine regions: upper, middle, and lower reaches. The three reaches had distinct habitat features of vegetation type and morphology, and in particular the lower reaches were colonized by the marsh grass Spartina maritima. Isotopic mixing models were used to estimate the relative contribution of each food source to the diets of invertebrates and fishes within the estuarine food web. The isotopic and fatty acid data showed similar results. In general, the lower reaches of the estuary were characterized by a higher deposition and assimilation by brachyuran crabs of carbon derived from marsh grass detritus, whiletowards the upper reaches a mixture of microphytobenthos and particulate organic matter (phytoplankton and detritus) was deposited and sustained the pelagic and benthic fauna. The highest deposition and assimilation of marsh grass detritus in the lower reaches of the estuary occurred during periods of low freshwater discharge (autumn and winter). In the upper reaches, microphytobenthos and suspended particulate organic matter were dominant basal food resources for the food web during all seasons. These results indicated that benthic consumers incorporated mainly local carbon sources from their local habitat.To clarify isotopic and fatty acid patterns I examined the trophic behaviour of the sesarmid crab Sesarma catenata through laboratory feeding experiments. Results from these experiments validated that decomposed leaves of riparian trees and the salt marsh plant S. maritima were the preferred food of the sesarmid crabs, potentially due to high bacterial loads. The remaining leaf material not assimilated by crabs, together with faecal material, are likely important subsidies for adjacent environments, hence representing an important energy pathway involving the microbial food chain. Furthermore, this dissertation showed the importance of mobile top predators as vectors energetically connecting distinct food chains within the estuary (i.e. littoral, benthic and pelagic). I concluded that a combination of physical (i.e. patterns of freshwater discharge and estuary morphology) and biological factors (i.e. organism feeding behaviour, mobility, primary productivity, the local vegetation type) influence the pattern of dominant primary organic matter sources, and therefore the food web structure along the estuarine environment. In particular, marsh grass detritus contributed substantially to the diets of estuarine fauna during periods of low freshwater discharge. Given the importance of the salt marsh habitat in providing trophic resources, it is important to preserve this environment to sustain the natural biota and ecosystem functioning.
- Full Text:
- Date Issued: 2015
- Authors: Bergamino Roman, Leandro
- Date: 2015
- Subjects: Estuarine ecology -- South Africa , Marine invertebrates -- South Africa -- Ecology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5921 , http://hdl.handle.net/10962/d1017799
- Description: Estuarine ecosystems are among the most biologically productive areas and they provide important ecosystem services such as erosion control, habitat and refugia for several species. These environments are characterized by the presence of a variety of organic matter sources due to their transitional position between rivers and the sea. The biotic compositions can undergo spatial and seasonal changes along the estuary due to the spatial and temporal fluctuations of environmental factors such as salinity, temperature and seston loads. Therefore, the different combinations of biotic and abiotic factors make each estuary a unique ecosystem. Because of this spatial and temporal complexity, the understanding of estuarine food web structure and which factors affect the trophic relationships within the ecosystem through space and time represent challenging tasks. Furthermore, estuaries are under an increasing number of anthropogenic perturbations because of the growing concentration of human populations in coastal areas. Knowledge of ecosystem structure and functioning is essential for effective conservation and management planning of coastal areas.In this dissertation, I combine the utilization of biological tracers to examine spatial and temporal variability in the food web structure within a small temperate and microtidal estuary located in South Africa. To this end, fatty acid profiles and stable isotope signatures were measured in several primary organic matter sources and consumers (including zooplankton, fishes and benthic invertebrates) during four consecutive seasons and in three different estuarine regions: upper, middle, and lower reaches. The three reaches had distinct habitat features of vegetation type and morphology, and in particular the lower reaches were colonized by the marsh grass Spartina maritima. Isotopic mixing models were used to estimate the relative contribution of each food source to the diets of invertebrates and fishes within the estuarine food web. The isotopic and fatty acid data showed similar results. In general, the lower reaches of the estuary were characterized by a higher deposition and assimilation by brachyuran crabs of carbon derived from marsh grass detritus, whiletowards the upper reaches a mixture of microphytobenthos and particulate organic matter (phytoplankton and detritus) was deposited and sustained the pelagic and benthic fauna. The highest deposition and assimilation of marsh grass detritus in the lower reaches of the estuary occurred during periods of low freshwater discharge (autumn and winter). In the upper reaches, microphytobenthos and suspended particulate organic matter were dominant basal food resources for the food web during all seasons. These results indicated that benthic consumers incorporated mainly local carbon sources from their local habitat.To clarify isotopic and fatty acid patterns I examined the trophic behaviour of the sesarmid crab Sesarma catenata through laboratory feeding experiments. Results from these experiments validated that decomposed leaves of riparian trees and the salt marsh plant S. maritima were the preferred food of the sesarmid crabs, potentially due to high bacterial loads. The remaining leaf material not assimilated by crabs, together with faecal material, are likely important subsidies for adjacent environments, hence representing an important energy pathway involving the microbial food chain. Furthermore, this dissertation showed the importance of mobile top predators as vectors energetically connecting distinct food chains within the estuary (i.e. littoral, benthic and pelagic). I concluded that a combination of physical (i.e. patterns of freshwater discharge and estuary morphology) and biological factors (i.e. organism feeding behaviour, mobility, primary productivity, the local vegetation type) influence the pattern of dominant primary organic matter sources, and therefore the food web structure along the estuarine environment. In particular, marsh grass detritus contributed substantially to the diets of estuarine fauna during periods of low freshwater discharge. Given the importance of the salt marsh habitat in providing trophic resources, it is important to preserve this environment to sustain the natural biota and ecosystem functioning.
- Full Text:
- Date Issued: 2015
Spatio-temporal variation in the phytobenthos and phytoplankton community structure and composition of particulate matter along a river-estuary continuum assessed using microscopic and stable isotope analyses
- Authors: Dalu, Tatenda
- Date: 2015
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54416 , vital:26563
- Description: Phytoplankton and phytobenthos communities play an important role in lotic systems as primary producers providing essential biomolecules to higher trophic oganisms and are important indicators for environmental or ecological change. In this thesis, field studies (observational and experimental) along a river–estuary continuum were conducted to assess the spatio-temporal variation and development of phytobenthos and phytoplankton communities using a combination of stable isotope and community analyses in a temperate southern African system across four study periods: September (early spring) and November/December (late spring) 2012, and February (summer) and May/June (winter) 2013. Additionally, the sources and composition of the particulate organic matter were also analysed using stable isotope (δ15N and δ13C) analysis. The effects of substrate type and flood occurrence were assessed through experimental studies at an up- and downstream site of the river after a major flood event that occurred between October and November 2012. Common household tiles were used as artificial substrates to study the development/succession of phytobenthos communities after the flood disturbance. Distinct diatom communities were observed between upstream and downstream sites and at each site, community structure changed with time indicating succession. In addition to recording diatom characteristics on three natural substrates, namely; macrophytes, rocks and sediment, artificial substrates observations were also made on three different types of artificial substrates, namely; brick, brown clay and grey clay tiles. The natural (species richness 78) and artificial substrates (sp. richness 93) had different communities with the latter having greater species richness. Common phytobenthos taxa were not restricted to a single substrate but preference was generally high for the artificial substrates, especially brown tiles (mean sp. richness 47). Results of the redundancy analysis (RDA) analysis indicated that ammonium, conductivity, total dissolved solids, salinity, pH, oxygen reduction potential, phosphate and water depth were the major determinants of the phytobenthos composition at the two sites. The spatio–temporal variation of phytoplankton and phytobenthos communities and allochthonous organic matter along the river–estuary continuum was assessed at 8 sites using a combination of community and stable isotope analyses. A total of 178 species belonging to 78 genera were recorded with diatoms being predominant, accounting for 81.9 % of the total abundance. The total chl-a concentration along the river-estuary continuum increased from spring to a high in summer before decreasing to a low in winter. Periphyton communities were observed to be significantly different across sites (p < 0.05) in terms of species richness, abundances and isotopically The high periphytic δ15N values (range 7.9–15.2 ‰) recorded at the downstream sites compared to the pristine upstream sites (δ15N values range 4–7 ‰) suggest nutrient enrichment most likely derived from anthropogenic sources. Overall, our results reveal general patterns of periphyton communities and stable isotopes and provide improved information in the use of periphyton δ15N as an excellent indicator of anthropogenic nitrogen pollution. Ecologists are interested in the factors that control, and the variability in, the contributions of different sources to mixed organic materials traveling through lotic systems. We hypothesized that the source matter fuelling mixed organic pools in a river-estuary continuum varies over space and time, with the upper reaches of a system characterized by allochthonous-dominated material and autochthonous contributions becoming more important in the lower reaches. Samples of the mixed organic pools and allochthonous and autochthonous source materials were collected during the four study periods. The C:N ratios of suspended particulate matter (SPM) collected during summer and winter indicated that the lower reaches of the system had similar organic matter contributions from the freshwater and terrestrial sources. Stable isotope analysis in R revealed that the contributions of autochthonous organic matter were high in SPM along the entire continuum, and aquatic macrophytes were significant contributors to SPM specifically in the upper reaches. The terrestrial leaves made major contributions to the SPM in the middle regions of the system (i.e. downstream sites of the river, particularly in early and late spring). Bulk detritus had large allochthonous matter components in the lower reaches (estuary), and the contributions of aquatic macrophytes and benthic algae to bulk detritus were high (> 50 %) in the upper to middle reaches (river), but low (< 20 %) in the lower reaches (estuary). The current investigation represents the first attempt to assess the validity of the River Continuum Concept (RCC) in a southern African temperate river. The phytoplankton and phytobenthos communities, and chl-a concentration followed a trend similar to that proposed for the river continuum concept (RCC). The middle reaches based on the phytobenthos or phytoplankton communities and chl-a concentrations which were employed as proxies for primary production, were the most productive, while the upper reaches were the least primary productive. The evaluation of organic matter contributions to the SPM and detritus along the river–estuary continuum provided a baseline assessment of the nature and sources of potential food for consumers inhabiting different locations during different times of the year. Incorporating such spatio-temporal variations in SPM and detritus into food web studies will improve our understanding of the flow of carbon through aquatic systems.
- Full Text:
- Date Issued: 2015
- Authors: Dalu, Tatenda
- Date: 2015
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54416 , vital:26563
- Description: Phytoplankton and phytobenthos communities play an important role in lotic systems as primary producers providing essential biomolecules to higher trophic oganisms and are important indicators for environmental or ecological change. In this thesis, field studies (observational and experimental) along a river–estuary continuum were conducted to assess the spatio-temporal variation and development of phytobenthos and phytoplankton communities using a combination of stable isotope and community analyses in a temperate southern African system across four study periods: September (early spring) and November/December (late spring) 2012, and February (summer) and May/June (winter) 2013. Additionally, the sources and composition of the particulate organic matter were also analysed using stable isotope (δ15N and δ13C) analysis. The effects of substrate type and flood occurrence were assessed through experimental studies at an up- and downstream site of the river after a major flood event that occurred between October and November 2012. Common household tiles were used as artificial substrates to study the development/succession of phytobenthos communities after the flood disturbance. Distinct diatom communities were observed between upstream and downstream sites and at each site, community structure changed with time indicating succession. In addition to recording diatom characteristics on three natural substrates, namely; macrophytes, rocks and sediment, artificial substrates observations were also made on three different types of artificial substrates, namely; brick, brown clay and grey clay tiles. The natural (species richness 78) and artificial substrates (sp. richness 93) had different communities with the latter having greater species richness. Common phytobenthos taxa were not restricted to a single substrate but preference was generally high for the artificial substrates, especially brown tiles (mean sp. richness 47). Results of the redundancy analysis (RDA) analysis indicated that ammonium, conductivity, total dissolved solids, salinity, pH, oxygen reduction potential, phosphate and water depth were the major determinants of the phytobenthos composition at the two sites. The spatio–temporal variation of phytoplankton and phytobenthos communities and allochthonous organic matter along the river–estuary continuum was assessed at 8 sites using a combination of community and stable isotope analyses. A total of 178 species belonging to 78 genera were recorded with diatoms being predominant, accounting for 81.9 % of the total abundance. The total chl-a concentration along the river-estuary continuum increased from spring to a high in summer before decreasing to a low in winter. Periphyton communities were observed to be significantly different across sites (p < 0.05) in terms of species richness, abundances and isotopically The high periphytic δ15N values (range 7.9–15.2 ‰) recorded at the downstream sites compared to the pristine upstream sites (δ15N values range 4–7 ‰) suggest nutrient enrichment most likely derived from anthropogenic sources. Overall, our results reveal general patterns of periphyton communities and stable isotopes and provide improved information in the use of periphyton δ15N as an excellent indicator of anthropogenic nitrogen pollution. Ecologists are interested in the factors that control, and the variability in, the contributions of different sources to mixed organic materials traveling through lotic systems. We hypothesized that the source matter fuelling mixed organic pools in a river-estuary continuum varies over space and time, with the upper reaches of a system characterized by allochthonous-dominated material and autochthonous contributions becoming more important in the lower reaches. Samples of the mixed organic pools and allochthonous and autochthonous source materials were collected during the four study periods. The C:N ratios of suspended particulate matter (SPM) collected during summer and winter indicated that the lower reaches of the system had similar organic matter contributions from the freshwater and terrestrial sources. Stable isotope analysis in R revealed that the contributions of autochthonous organic matter were high in SPM along the entire continuum, and aquatic macrophytes were significant contributors to SPM specifically in the upper reaches. The terrestrial leaves made major contributions to the SPM in the middle regions of the system (i.e. downstream sites of the river, particularly in early and late spring). Bulk detritus had large allochthonous matter components in the lower reaches (estuary), and the contributions of aquatic macrophytes and benthic algae to bulk detritus were high (> 50 %) in the upper to middle reaches (river), but low (< 20 %) in the lower reaches (estuary). The current investigation represents the first attempt to assess the validity of the River Continuum Concept (RCC) in a southern African temperate river. The phytoplankton and phytobenthos communities, and chl-a concentration followed a trend similar to that proposed for the river continuum concept (RCC). The middle reaches based on the phytobenthos or phytoplankton communities and chl-a concentrations which were employed as proxies for primary production, were the most productive, while the upper reaches were the least primary productive. The evaluation of organic matter contributions to the SPM and detritus along the river–estuary continuum provided a baseline assessment of the nature and sources of potential food for consumers inhabiting different locations during different times of the year. Incorporating such spatio-temporal variations in SPM and detritus into food web studies will improve our understanding of the flow of carbon through aquatic systems.
- Full Text:
- Date Issued: 2015
Spawning and nest guarding of the river goby (Glossogobius callidus) from the Eastern Cape province of South Africa
- Wasserman, Ryan J, Vink, Tim J F, Woodford, Darragh J, Froneman, P William
- Authors: Wasserman, Ryan J , Vink, Tim J F , Woodford, Darragh J , Froneman, P William
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68144 , vital:29203 , https://doi.org/10.1111/aje.12228
- Description: Publisher version , Introduction: The River goby, Glossogobius callidus (Smith 1937), occurs naturally in rivers and the upper reaches of estuaries along the eastern seaboard of southern Africa (Whitfield, 1998; James et al., 2007; Wasserman, Strydom & Wooldridge, 2010). This fish species is among the most abundant of fishes in many river systems of the region and is considered an important predator in these habitats, feeding on invertebrates and small fish (Whitfield, 1998; Strydom & Neira, 2006; Wasserman, 2012; Wasserman et al., 2014). Despite this, ecological information on this goby is sparse and to date, no published records on the biology of the species exist. The urgent need for such information was recently highlighted in a study that identified G. callidus as a potentially invasive species, given its ability to rapidly establish in novel environments (Woodford et al., 2013). The present study therefore endeavoured to determine the reproductive guild to which G. callidus belong and describe aspects of their spawning. This was performed by closely observing wild caught, mature G. callidus in aquaria over a 25-day period.
- Full Text: false
- Date Issued: 2015
- Authors: Wasserman, Ryan J , Vink, Tim J F , Woodford, Darragh J , Froneman, P William
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68144 , vital:29203 , https://doi.org/10.1111/aje.12228
- Description: Publisher version , Introduction: The River goby, Glossogobius callidus (Smith 1937), occurs naturally in rivers and the upper reaches of estuaries along the eastern seaboard of southern Africa (Whitfield, 1998; James et al., 2007; Wasserman, Strydom & Wooldridge, 2010). This fish species is among the most abundant of fishes in many river systems of the region and is considered an important predator in these habitats, feeding on invertebrates and small fish (Whitfield, 1998; Strydom & Neira, 2006; Wasserman, 2012; Wasserman et al., 2014). Despite this, ecological information on this goby is sparse and to date, no published records on the biology of the species exist. The urgent need for such information was recently highlighted in a study that identified G. callidus as a potentially invasive species, given its ability to rapidly establish in novel environments (Woodford et al., 2013). The present study therefore endeavoured to determine the reproductive guild to which G. callidus belong and describe aspects of their spawning. This was performed by closely observing wild caught, mature G. callidus in aquaria over a 25-day period.
- Full Text: false
- Date Issued: 2015
Specialist workforce development through mentoring: comparing collaborative programme evaluation using action research and realist evaluation
- Akhurst, Jacqueline E, Lawson, Sally
- Authors: Akhurst, Jacqueline E , Lawson, Sally
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143771 , vital:38281 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: This Workforce Innovations Programme (WIP) was for healthcare practitioners working in north east England. The innovative mentoring-focused WIP aimed to increase capacity and capability, and to improve services and outcomes for people living with long term neurological conditions. Mentors were matched with practitioners outside of their specialisms and focused on community and partnership working as alternatives to dominant modes of practice. This paper will highlight key outcomes and contextual challenges. It will explore collaborative action research for practitioner development, evidencing the participants’ learning. A medium term realist evaluation then provides data about the value of the WIP; and illustrates ways the programme worked for practitioners and people who used services, to support the drive for improved outcomes. It will compare and contrast the contributions of both forms of programme evaluation, and critique some of the discourses of workforce improvement initiatives.
- Full Text:
- Date Issued: 2015
- Authors: Akhurst, Jacqueline E , Lawson, Sally
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143771 , vital:38281 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: This Workforce Innovations Programme (WIP) was for healthcare practitioners working in north east England. The innovative mentoring-focused WIP aimed to increase capacity and capability, and to improve services and outcomes for people living with long term neurological conditions. Mentors were matched with practitioners outside of their specialisms and focused on community and partnership working as alternatives to dominant modes of practice. This paper will highlight key outcomes and contextual challenges. It will explore collaborative action research for practitioner development, evidencing the participants’ learning. A medium term realist evaluation then provides data about the value of the WIP; and illustrates ways the programme worked for practitioners and people who used services, to support the drive for improved outcomes. It will compare and contrast the contributions of both forms of programme evaluation, and critique some of the discourses of workforce improvement initiatives.
- Full Text:
- Date Issued: 2015
Specific rewards for tax compliance: responses of small business owners in Ekurhuleni, South Africa
- Bornman, Marina, Stack, Elizabeth M
- Authors: Bornman, Marina , Stack, Elizabeth M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145325 , vital:38428 , https://heinonline.org/HOL/Page?handle=hein.journals/ejotaxrs13anddiv=35andg_sent=1andcasa_token=andcollection=journals
- Description: The literature reviewed documents the positive effects of rewards in encouraging desired behaviour, but rewards may have a crowding-in effect, strengthening intrinsic motivation, or a crowding-out effect, weakening it. External interventions may therefore be perceived as supportive, fostering self-esteem and self-determination, while those perceived as controlling may have the opposite effect. A number of countries have adopted a strategy of rewarding tax compliance. The rewards range from certificates awarded to compliant taxpayers, to privilege cards providing opportunities for discounts or special treatment, to lotteries in which compliant taxpayers can participate. The reward strategies are often accompanied by publicity programmes. Two such hypothetical strategies were presented to participants in a survey conducted amongst small business owners in Ekurhuleni, South Africa, to gauge their responses.
- Full Text:
- Date Issued: 2015
- Authors: Bornman, Marina , Stack, Elizabeth M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145325 , vital:38428 , https://heinonline.org/HOL/Page?handle=hein.journals/ejotaxrs13anddiv=35andg_sent=1andcasa_token=andcollection=journals
- Description: The literature reviewed documents the positive effects of rewards in encouraging desired behaviour, but rewards may have a crowding-in effect, strengthening intrinsic motivation, or a crowding-out effect, weakening it. External interventions may therefore be perceived as supportive, fostering self-esteem and self-determination, while those perceived as controlling may have the opposite effect. A number of countries have adopted a strategy of rewarding tax compliance. The rewards range from certificates awarded to compliant taxpayers, to privilege cards providing opportunities for discounts or special treatment, to lotteries in which compliant taxpayers can participate. The reward strategies are often accompanied by publicity programmes. Two such hypothetical strategies were presented to participants in a survey conducted amongst small business owners in Ekurhuleni, South Africa, to gauge their responses.
- Full Text:
- Date Issued: 2015
Spectroscopic and nonlinear optical properties of the four positional isomers of 4α-(4-tert-butylphenoxy) phthalocyanine
- Ngubeni, Grace N, Britton, Jonathan, Mack, John, New, Edward, Hancox, Ian, Walker, Marc, Nyokong, Tebello, Jones, Tim S, Khene,Samson M
- Authors: Ngubeni, Grace N , Britton, Jonathan , Mack, John , New, Edward , Hancox, Ian , Walker, Marc , Nyokong, Tebello , Jones, Tim S , Khene,Samson M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241448 , vital:50940 , xlink:href="https://doi.org/10.1039/C5TC01601K"
- Description: The spectroscopic and nonlinear optical properties of the positional isomers of metal free 4α-(4-tert-butylphenoxy) phthalocyanine are presented. Second order nonlinear polarizability (β), imaginary hyperpolarizability (Im(γ)) and imaginary susceptibility (Im[χ(3)]) values were determined for the four positional isomers. The measured β values of the four isomers displayed the following trend, C4h (34.0 × 10−5 m MW−1) > D2h (28.8 × 10−5 m MW−1) > C2v (22.8 × 10−5 m MW−1) > Cs (13.7 × 10−5 m MW−1).
- Full Text:
- Date Issued: 2015
- Authors: Ngubeni, Grace N , Britton, Jonathan , Mack, John , New, Edward , Hancox, Ian , Walker, Marc , Nyokong, Tebello , Jones, Tim S , Khene,Samson M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241448 , vital:50940 , xlink:href="https://doi.org/10.1039/C5TC01601K"
- Description: The spectroscopic and nonlinear optical properties of the positional isomers of metal free 4α-(4-tert-butylphenoxy) phthalocyanine are presented. Second order nonlinear polarizability (β), imaginary hyperpolarizability (Im(γ)) and imaginary susceptibility (Im[χ(3)]) values were determined for the four positional isomers. The measured β values of the four isomers displayed the following trend, C4h (34.0 × 10−5 m MW−1) > D2h (28.8 × 10−5 m MW−1) > C2v (22.8 × 10−5 m MW−1) > Cs (13.7 × 10−5 m MW−1).
- Full Text:
- Date Issued: 2015