A Framework for Broadband Adoption in Buffalo City Metropolitan Municipality to Enable Citizen Access to e-Government
- Twetwa-Dube, Sithandile Pornelia
- Authors: Twetwa-Dube, Sithandile Pornelia
- Date: 2020
- Subjects: Electronic government information
- Language: English
- Type: Thesis , Masters , MCom (Information Systems)
- Identifier: http://hdl.handle.net/10353/18963 , vital:43003
- Description: E-government has been adopted as one of the cornerstones of the government‘s strategy for making services accessible to its citizens. The aim of this broadband adoption is to provide high quality public sector services via digital channels to improve cost-efficiency and generate benefits to municipality employees and citizen. A major challenge that municipalities face is the lack of public participation which restricts levels of communication between governments and municipalities and the citizen where public misses out on information and services available online, which results in further inequality. This has a devastating impact on service delivery because participatory democracy would be non-existent. Limited IT infrastructure, resistance to change, cultural barriers and exposure of malpractice are main themes related to IT usage or facilitating IT access for the wider public. Furthermore, lack of meaningful participation and freedom of association emerged as themes related to governance effectiveness. A mixed approach within a case study was considered, and data was collected through an online questionnaire and review of current literature. The study collected primary data by conducting web based questionnaires comprising sixty respondent’s citizens and fifteen municipal employees, including Information and Communication Technology (ICT) employees and broadband task team members. Statistical Package for the Social Science (SPSS) to analyse data from questionnaires. The selected BCMM employees of the population were known to have the relevant knowledge, time and experience to participate. Responses to each question developed the framework further based on the findings. Respondents were selected based on their appropriate knowledge and experience of the problem domain. Six experts were selected for final evaluation of the research findings. Firstly, the findings provided on barriers impact on the adoption of e-government. Secondly, on the techniques available to ensure access to e-government within BCMM. Thirdly, on the availability of technologies currently in the Buffalo City Metropolitan Municipality. Finally, on the elements of a Buffalo City Metropolitan Municipality broadband adoption strategy. This study evaluates barriers of e-government adoption, assessing strategies and techniques for accessing e-government services, examines current technologies to support e-government service within municipalities and analyses elements of Buffalo City Metropolitan Municipality broadband adoption strategy. A broadband adoption model was proposed based on empirical findings. Key adoption factors include adoption benefits and drivers, concerns and barriers and adoption interventions. These factors provide an essential foundation for the development of the proposed broadband adoption framework. The contribution of this study is a framework based on the Unified Theory of Acceptance and Use of Technology (UTAUT) and Technology Organisation Environment (TOE) framework to determine factors that influence or restrict a citizen’s intention to use and adopt technology, specifically broadband, in e-government services as a tool for citizen engagement. The proposed framework aims to overcome barriers to broadband adoption 4 Final Submission of Thesis, Dissertation or Research Report/Project, Conference or Exam Paper in municipalities, specifically Buffalo City Metropolitan Municipality (BCMM) to enable citizens’ access to e-government services.
- Full Text:
- Date Issued: 2020
- Authors: Twetwa-Dube, Sithandile Pornelia
- Date: 2020
- Subjects: Electronic government information
- Language: English
- Type: Thesis , Masters , MCom (Information Systems)
- Identifier: http://hdl.handle.net/10353/18963 , vital:43003
- Description: E-government has been adopted as one of the cornerstones of the government‘s strategy for making services accessible to its citizens. The aim of this broadband adoption is to provide high quality public sector services via digital channels to improve cost-efficiency and generate benefits to municipality employees and citizen. A major challenge that municipalities face is the lack of public participation which restricts levels of communication between governments and municipalities and the citizen where public misses out on information and services available online, which results in further inequality. This has a devastating impact on service delivery because participatory democracy would be non-existent. Limited IT infrastructure, resistance to change, cultural barriers and exposure of malpractice are main themes related to IT usage or facilitating IT access for the wider public. Furthermore, lack of meaningful participation and freedom of association emerged as themes related to governance effectiveness. A mixed approach within a case study was considered, and data was collected through an online questionnaire and review of current literature. The study collected primary data by conducting web based questionnaires comprising sixty respondent’s citizens and fifteen municipal employees, including Information and Communication Technology (ICT) employees and broadband task team members. Statistical Package for the Social Science (SPSS) to analyse data from questionnaires. The selected BCMM employees of the population were known to have the relevant knowledge, time and experience to participate. Responses to each question developed the framework further based on the findings. Respondents were selected based on their appropriate knowledge and experience of the problem domain. Six experts were selected for final evaluation of the research findings. Firstly, the findings provided on barriers impact on the adoption of e-government. Secondly, on the techniques available to ensure access to e-government within BCMM. Thirdly, on the availability of technologies currently in the Buffalo City Metropolitan Municipality. Finally, on the elements of a Buffalo City Metropolitan Municipality broadband adoption strategy. This study evaluates barriers of e-government adoption, assessing strategies and techniques for accessing e-government services, examines current technologies to support e-government service within municipalities and analyses elements of Buffalo City Metropolitan Municipality broadband adoption strategy. A broadband adoption model was proposed based on empirical findings. Key adoption factors include adoption benefits and drivers, concerns and barriers and adoption interventions. These factors provide an essential foundation for the development of the proposed broadband adoption framework. The contribution of this study is a framework based on the Unified Theory of Acceptance and Use of Technology (UTAUT) and Technology Organisation Environment (TOE) framework to determine factors that influence or restrict a citizen’s intention to use and adopt technology, specifically broadband, in e-government services as a tool for citizen engagement. The proposed framework aims to overcome barriers to broadband adoption 4 Final Submission of Thesis, Dissertation or Research Report/Project, Conference or Exam Paper in municipalities, specifically Buffalo City Metropolitan Municipality (BCMM) to enable citizens’ access to e-government services.
- Full Text:
- Date Issued: 2020
Exploring the psychosocial effects of removing teenagers from their homes to places of safety
- Authors: Boxongo , Sisipho
- Date: 2020
- Subjects: Teenagers
- Language: English
- Type: Thesis , Masters , MSW
- Identifier: http://hdl.handle.net/10353/18073 , vital:42226
- Description: The child welfare system investigate over 2 Million children each year for parental abuse or neglect, yet little is known about the psychosocial effects of removing teenagers from their homes and placing them in the place of safety. Although an abusive family would undoubtedly be harmful to children, removing a child from his or her family can be just as traumatic. Long term outcome are rarely observed, and teenagers placed in the place of safety are likely differ from those not placed. Hence this study took a microscopic scrutiny at the effects of the teenager`s removal from their home environment to a place of safety. In carrying out this research qualitative method of data collection was used. The study outlined the factors that lead to removal of teenagers from their home environment to the place of safety. The study found that some of the teenagers who were removed from their home environment were due to poverty, maltreatment, negligence and child abuse at home. The study also revealed that the placement of the teenagers in the places of safety expose the teenagers to psychological, physical, emotional and behavioural negative experiences. The teenagers that participated in the study mentioned that they are stigmatised by the community and peers at school, some also cited that they have lost contact with their families. It was also found out that; the professionals who participated in the study also too experience some challenges in rendering services to the teenagers as sometimes they don`t get informed about the children`s situation on their arrival in the centre. On the other hand, another professional declared that they are trying by all means to cater for all the needs of the children, but they are failed by the case managers and other stakeholders, such as department of social development who delay the process of obtaining court orders which makes it difficult for the child to be funded and also the process of reunifying the child with the biological family.
- Full Text:
- Date Issued: 2020
- Authors: Boxongo , Sisipho
- Date: 2020
- Subjects: Teenagers
- Language: English
- Type: Thesis , Masters , MSW
- Identifier: http://hdl.handle.net/10353/18073 , vital:42226
- Description: The child welfare system investigate over 2 Million children each year for parental abuse or neglect, yet little is known about the psychosocial effects of removing teenagers from their homes and placing them in the place of safety. Although an abusive family would undoubtedly be harmful to children, removing a child from his or her family can be just as traumatic. Long term outcome are rarely observed, and teenagers placed in the place of safety are likely differ from those not placed. Hence this study took a microscopic scrutiny at the effects of the teenager`s removal from their home environment to a place of safety. In carrying out this research qualitative method of data collection was used. The study outlined the factors that lead to removal of teenagers from their home environment to the place of safety. The study found that some of the teenagers who were removed from their home environment were due to poverty, maltreatment, negligence and child abuse at home. The study also revealed that the placement of the teenagers in the places of safety expose the teenagers to psychological, physical, emotional and behavioural negative experiences. The teenagers that participated in the study mentioned that they are stigmatised by the community and peers at school, some also cited that they have lost contact with their families. It was also found out that; the professionals who participated in the study also too experience some challenges in rendering services to the teenagers as sometimes they don`t get informed about the children`s situation on their arrival in the centre. On the other hand, another professional declared that they are trying by all means to cater for all the needs of the children, but they are failed by the case managers and other stakeholders, such as department of social development who delay the process of obtaining court orders which makes it difficult for the child to be funded and also the process of reunifying the child with the biological family.
- Full Text:
- Date Issued: 2020
An examination of teaching strategies for mediating the construction of environmental content knowledge: a case of Grade 11 Life Sciences teaching in two Eastern Cape schools
- Authors: Chitsiga, Christina
- Date: 2016
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/361 , vital:19953
- Description: In South Africa the new Curriculum Assessment and Policy Statement (CAPS) introduced a more strongly content referenced curriculum which has commitments to active and critical approaches to learning, and to environment and sustainability content. Successful implementation of CAPS requires that teachers attain the requisite knowledge and pedagogical content knowledge for working with environmental and sustainability content. The study examined teachers’ knowledge of environmental content as well as how teachers are mediating learning, through exploring the classroom techniques used by teachers working with environmental content. This was to examine how teachers are through their teaching bridging the gap in the understanding, investigation and application of environmental content in the curriculum. The study used a number of approaches from the field of environmental education which offer different lenses (or pedagogical sensitizing constructs) for viewing mediation processes as a relational process of knowledge construction. These pedagogical constructs were: knowledge co-construction where perspectives and understandings are shared in the process of social relations (deliberation); relating environmental content knowledge to cultural historical context (situated learning); relating environmental content knowledge to everyday and intergenerational knowledge through hands on experience (proximity experience) and developing an iterative relationship between environmental content knowledge and sustainability practices (practical reasoning). Practice theory as suggested by Schatzki (2005) and a theory of practice architectures elaborating on Schatzki’s practice theory (Kemmis & Heikkinen, 2011) was used as the ontological lens to help in understanding the mediation of environmental content knowledge. Practice theory was used for exploring pedagogical practice in terms of sayings, doings and relatings by teachers, and practice architectures that represent enabling or constraining factors of teachers practice. This research was an interpretive case study drawing on findings from lesson observations, semi structured interviews, stimulated recall interviews and document analysis. The research found that teachers used different strategies to enhance their environmental content and pedagogical content knowledge to present the mediation. Teachers are supporting situated learning and deliberation in environmental learning. Another finding was that teachers could be enabled to enhance proximity experiences and practical reason in their mediating approaches in environmental learning. The research further showed that teachers could benefit from teacher professional development programmes that explicitly develop pedagogical content knowledge to support critical deliberation, proximity encounters, situated learning and practical reasoning in order to work with the diverse complex places-based, socio-cultural-historical nature of environmental curriculum content in the context of sustainability practices. Findings also showed that there were constraining factors to mediation of environmental learning. These constraining factors from the research were firstly in material economic arrangements of timetable compliance in CAPS, ability to find internet resources and availability of resources. Secondly, present were constraining factors of socio-political arrangements of CAPS curriculum document prescriptiveness, multiculturalism, learning institution management and governance. Thirdly, cultural discursive arrangements of teacher learner language, knowledge of the language of the field affected mediation. Teachers passion for environmental content topics, the ability of teachers’ to improvise resources in mediating environmental content lessons and the ability of teachers’ to navigate a stringent CAPS timetable were found in this research to be enabling mediation. Recommendations from the research are ongoing teacher refresher workshops on the environmental content in the CAPS curriculum, teachers’ need more input on strategies to mediate environmental content, teachers’ prior knowledge of new knowledge can be used to strengthen teacher professional development processes, teachers’ prior knowledge needs to be deepened and reinforced, there is need to develop quality educational resources encompassing a variety of pedagogical sensitizing constructs and support needs to be given for familiarising teachers with teaching materials and their appropriate use . These could help to strengthen mediation of environmental content knowledge in the Grade 11 CAPS Life Sciences and inform South African teacher professional development programmes seeking to understand classroom practices in relation to environmental content.
- Full Text:
- Date Issued: 2016
- Authors: Chitsiga, Christina
- Date: 2016
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/361 , vital:19953
- Description: In South Africa the new Curriculum Assessment and Policy Statement (CAPS) introduced a more strongly content referenced curriculum which has commitments to active and critical approaches to learning, and to environment and sustainability content. Successful implementation of CAPS requires that teachers attain the requisite knowledge and pedagogical content knowledge for working with environmental and sustainability content. The study examined teachers’ knowledge of environmental content as well as how teachers are mediating learning, through exploring the classroom techniques used by teachers working with environmental content. This was to examine how teachers are through their teaching bridging the gap in the understanding, investigation and application of environmental content in the curriculum. The study used a number of approaches from the field of environmental education which offer different lenses (or pedagogical sensitizing constructs) for viewing mediation processes as a relational process of knowledge construction. These pedagogical constructs were: knowledge co-construction where perspectives and understandings are shared in the process of social relations (deliberation); relating environmental content knowledge to cultural historical context (situated learning); relating environmental content knowledge to everyday and intergenerational knowledge through hands on experience (proximity experience) and developing an iterative relationship between environmental content knowledge and sustainability practices (practical reasoning). Practice theory as suggested by Schatzki (2005) and a theory of practice architectures elaborating on Schatzki’s practice theory (Kemmis & Heikkinen, 2011) was used as the ontological lens to help in understanding the mediation of environmental content knowledge. Practice theory was used for exploring pedagogical practice in terms of sayings, doings and relatings by teachers, and practice architectures that represent enabling or constraining factors of teachers practice. This research was an interpretive case study drawing on findings from lesson observations, semi structured interviews, stimulated recall interviews and document analysis. The research found that teachers used different strategies to enhance their environmental content and pedagogical content knowledge to present the mediation. Teachers are supporting situated learning and deliberation in environmental learning. Another finding was that teachers could be enabled to enhance proximity experiences and practical reason in their mediating approaches in environmental learning. The research further showed that teachers could benefit from teacher professional development programmes that explicitly develop pedagogical content knowledge to support critical deliberation, proximity encounters, situated learning and practical reasoning in order to work with the diverse complex places-based, socio-cultural-historical nature of environmental curriculum content in the context of sustainability practices. Findings also showed that there were constraining factors to mediation of environmental learning. These constraining factors from the research were firstly in material economic arrangements of timetable compliance in CAPS, ability to find internet resources and availability of resources. Secondly, present were constraining factors of socio-political arrangements of CAPS curriculum document prescriptiveness, multiculturalism, learning institution management and governance. Thirdly, cultural discursive arrangements of teacher learner language, knowledge of the language of the field affected mediation. Teachers passion for environmental content topics, the ability of teachers’ to improvise resources in mediating environmental content lessons and the ability of teachers’ to navigate a stringent CAPS timetable were found in this research to be enabling mediation. Recommendations from the research are ongoing teacher refresher workshops on the environmental content in the CAPS curriculum, teachers’ need more input on strategies to mediate environmental content, teachers’ prior knowledge of new knowledge can be used to strengthen teacher professional development processes, teachers’ prior knowledge needs to be deepened and reinforced, there is need to develop quality educational resources encompassing a variety of pedagogical sensitizing constructs and support needs to be given for familiarising teachers with teaching materials and their appropriate use . These could help to strengthen mediation of environmental content knowledge in the Grade 11 CAPS Life Sciences and inform South African teacher professional development programmes seeking to understand classroom practices in relation to environmental content.
- Full Text:
- Date Issued: 2016
Mapping Nitrogen Loading in Freshwater Systems: Using Aquatic Biota to Trace Nutrients
- Authors: Motitsoe, Samuel Nkopane
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5945 , http://hdl.handle.net/10962/d1020819
- Description: The majority of river systems in developing countries like South Africa, are found in catchments areas that are densely human populated, therefore are subjected to intense land-use and developmental pressures. Anthropogenic nutrient pollution or the excessive addition of nutrients is one important type of stressors that river systems often experience through intense land-use, which includes poor waste management and agricultural practices. Such events are referred to as the “urban syndrome”, were human populations and developmental demands outpace ecosystem services. Traditional measurements of water quality (e.g. physicochemical and micro-nutrient assessments) and biological monitoring (e.g. South African Scoring System 5, SASS5) techniques for assessing ecosystem health have being widely used to reflect the ecological health and status of river systems. However these techniques have a number of challenges associated with their application. SASS5 which is used most prevalently in southern Africa for example, can only be applied in lotic systems, it is habitat dependent and finally (but arguably most importantly) it cannot identify the source of pollution inputs. Recent laboratory studies using stable isotopic ratios (δ15N and δ13C) of aquatic macrophytes (duckweed: Spirodela sp.) have shown successful differentiation between different N-sources and the mapping of temporal and spatial nitrogen dynamics in freshwater systems. Furthermore δ15N isotopic values of Spirodela sp. showed the capability to act as an early warning indicator of eutrophication, before the onset of aquatic ecosystem degradation. Therefore, this study aimed to field test the potential of sewage plume mapping using the stable isotopic values of Spirodela sp. and aquatic macroinvertebrates at nine study sites on the Bloukrans-Kowie River and ten study sites on the Bushman-New Year’s River systems in the Eastern Cape, South Africa. And more...
- Full Text:
- Date Issued: 2016
- Authors: Motitsoe, Samuel Nkopane
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5945 , http://hdl.handle.net/10962/d1020819
- Description: The majority of river systems in developing countries like South Africa, are found in catchments areas that are densely human populated, therefore are subjected to intense land-use and developmental pressures. Anthropogenic nutrient pollution or the excessive addition of nutrients is one important type of stressors that river systems often experience through intense land-use, which includes poor waste management and agricultural practices. Such events are referred to as the “urban syndrome”, were human populations and developmental demands outpace ecosystem services. Traditional measurements of water quality (e.g. physicochemical and micro-nutrient assessments) and biological monitoring (e.g. South African Scoring System 5, SASS5) techniques for assessing ecosystem health have being widely used to reflect the ecological health and status of river systems. However these techniques have a number of challenges associated with their application. SASS5 which is used most prevalently in southern Africa for example, can only be applied in lotic systems, it is habitat dependent and finally (but arguably most importantly) it cannot identify the source of pollution inputs. Recent laboratory studies using stable isotopic ratios (δ15N and δ13C) of aquatic macrophytes (duckweed: Spirodela sp.) have shown successful differentiation between different N-sources and the mapping of temporal and spatial nitrogen dynamics in freshwater systems. Furthermore δ15N isotopic values of Spirodela sp. showed the capability to act as an early warning indicator of eutrophication, before the onset of aquatic ecosystem degradation. Therefore, this study aimed to field test the potential of sewage plume mapping using the stable isotopic values of Spirodela sp. and aquatic macroinvertebrates at nine study sites on the Bloukrans-Kowie River and ten study sites on the Bushman-New Year’s River systems in the Eastern Cape, South Africa. And more...
- Full Text:
- Date Issued: 2016
IsiXhosa storytelling (iintsomi) as an alternative medium for maternal health education in primary healthcare in the Eastern Cape
- Authors: Zakaza, Nompucuko
- Date: 2015
- Subjects: Communication in community health services -- South Africa -- Eastern Cape , Communication in reproductive health -- South Africa -- Eastern Cape , Storytelling in education , Applied folklore
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3648 , http://hdl.handle.net/10962/d1017188
- Description: The aim of this study is to explore the introduction of IsiXhosa (iintsomi) as an alternative method in the maternal health education in rural Primary Health Care in the Eastern Cape. An informal preliminary observation of a maternal health lesson by the researcher indicated a further need for maternal health educators to introduce storytelling into the health content themes. To re-inforce the maternal health educator lesson on the causes of teenage pregnancy, lifestyles for pregnant women, causes of miscarriage and termination of pregnancy, the Community Health Workers can undoubtedly use isiXhosa iintsomi in selected clinics and maternal waiting homes. As a readily available resource that cuts across all literacy barriers, iintsomi (isiXhosa) fosters a cross-cultural consultation which enables the healthcare worker to convey messages that make sense to the rural women. While the conventional methods of teaching have a tendency to create tension and lack of participation, use of folktale (iintsomi) have huge potential to bring lesson enjoyment; a meaningful interaction and story sharing by the maternal health educator, the pregnant women and greater community; access to important health messages; and strengthened utilisation of Primary Health Care. The study therefore suggests that there is a place for isiXhosa iintsomi: From the Fireplace into the Workplace.
- Full Text:
- Date Issued: 2015
- Authors: Zakaza, Nompucuko
- Date: 2015
- Subjects: Communication in community health services -- South Africa -- Eastern Cape , Communication in reproductive health -- South Africa -- Eastern Cape , Storytelling in education , Applied folklore
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3648 , http://hdl.handle.net/10962/d1017188
- Description: The aim of this study is to explore the introduction of IsiXhosa (iintsomi) as an alternative method in the maternal health education in rural Primary Health Care in the Eastern Cape. An informal preliminary observation of a maternal health lesson by the researcher indicated a further need for maternal health educators to introduce storytelling into the health content themes. To re-inforce the maternal health educator lesson on the causes of teenage pregnancy, lifestyles for pregnant women, causes of miscarriage and termination of pregnancy, the Community Health Workers can undoubtedly use isiXhosa iintsomi in selected clinics and maternal waiting homes. As a readily available resource that cuts across all literacy barriers, iintsomi (isiXhosa) fosters a cross-cultural consultation which enables the healthcare worker to convey messages that make sense to the rural women. While the conventional methods of teaching have a tendency to create tension and lack of participation, use of folktale (iintsomi) have huge potential to bring lesson enjoyment; a meaningful interaction and story sharing by the maternal health educator, the pregnant women and greater community; access to important health messages; and strengthened utilisation of Primary Health Care. The study therefore suggests that there is a place for isiXhosa iintsomi: From the Fireplace into the Workplace.
- Full Text:
- Date Issued: 2015
Kaffirmeid and other stories
- Authors: Madingwane, June
- Date: 2014
- Subjects: South African fiction (English) -- 21st century , Short stories, South African -- 21st century , Creative writing (Higher education) -- Research -- South Africa , Creative writing -- Fiction , South African fiction (English) -- Study and teaching (Higher)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:5983 , http://hdl.handle.net/10962/d1015659
- Description: These stories are about people’s experiences in relationships and how they overcome and resolve problems with their partners. Some explore myths and unexplained occurrences that raise many questions.
- Full Text:
- Date Issued: 2014
- Authors: Madingwane, June
- Date: 2014
- Subjects: South African fiction (English) -- 21st century , Short stories, South African -- 21st century , Creative writing (Higher education) -- Research -- South Africa , Creative writing -- Fiction , South African fiction (English) -- Study and teaching (Higher)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:5983 , http://hdl.handle.net/10962/d1015659
- Description: These stories are about people’s experiences in relationships and how they overcome and resolve problems with their partners. Some explore myths and unexplained occurrences that raise many questions.
- Full Text:
- Date Issued: 2014
Assessing the impacts of invasive non-native African sharptooth catfish Clarias Gariepinus
- Authors: Kadye, Wilbert Takawira
- Date: 2012
- Subjects: Catfishes -- South Africa -- Eastern Cape Biological invasions -- South Africa -- Great Fish River Biological invasions -- South Africa -- Sundays River Clarias gariepinus Freshwater ecology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5227 , http://hdl.handle.net/10962/d1005070
- Description: Invasive species are of particular concern as they have the potential to alter community structure and food web relationships within their invaded habitats. African sharptooth catfish Clarias gariepinus, a generalist predator, was introduced through an inter-basin water transfer scheme into the Great Fish and Sundays Rivers, Eastern Cape, South Africa, where it threatens the native riverine biota. This thesis assessed its impact from a trophic perspective. Patterns in catfish distribution and abundance revealed an upstream to downstream gradient that was associated with spatial distribution of most species within the mainstream, and a mainstream to tributary gradient that was associated with the spatial distribution of native minnows. The catfish was predicted to occur widely within the mainstem habitats and to decrease progressively along the mainstrem to tributary gradient with the physico-chemical environment being a good proxy for predicting both its occurrence and abundance. The results suggest the catfish proliferated within mainstem habitats where invasion resistance was possibly reduced due to alteration of flow. Population dynamics and size structuring of two native cyprinid minnows Pseudobarbus afer and Barbus anoplus, threatened by catfish, were examined within uninvaded headwater streams in relation to their proximate physical habitats. Their habitats were characterised by seasonal variation in physico-chemical conditions and a spatial variation in substrata compositions. No evidence of differences was found between seasons for density and capture probability for either species. The population size and density for P. afer was found to increase with increasing proportion of boulders. In comparison, B. anoplus population size and probability of capture increased with increasing proportion of bedrock and bank vegetation, respectively. Size structuring was explained predominantly by seasonality and habitat variables for P. afer and B. anoplus, respectively. Stable isotope ratios of carbon and nitrogen were used to compare the spatial variation in both the community-wide and catfish-specific niches and to estimate catfish prey sources from different habitats within the invaded systems. Aquatic community and catfish niches were statistically different among localities, suggesting that each locality had a distinct community-wide trophic structure. Dispersion metrics indicated no evidence of differences in the clustering among individuals, but provided evidence of differences in path trajectories for the comparisons of catfish populations that suggested dietary plasticity within different localities. Dietary studies revealed both ontogenetic shift and omnivory that suggested that catfish may exhibit less pronounced top-down effects within its invaded habitats. Manipulative experiments were used to test the response of benthic macroinvertebrates within two rivers that were differentially impacted by catfish as a presstype disturbance. Macroinvertebrates were non-responsive to catfish presence within a system where catfish had previously been established. In contrast, excluding catfish in this system indicated a response that suggested the importance of refuge within invaded habitats and the possible recovery pattern of certain macroinvertebrate taxa. By comparison, introduction of catfish within previously uninvaded localities provided evidence of direct catfish impact through elimination of conspicuous taxa. Acoustic telemetry was used to investigate catfish movement patterns within an invaded lentic habitat and provided evidence that habitat utilisation was non-random. The shallow and structured river mouth habitat, which was most utilised, was probably the most ideal for its breeding and feeding. This inferred potential overlap with native species and suggested the risk of predation and competitive interference. Catfish also exhibited both nocturnal and diurnal activity patterns that were probably related to feeding.
- Full Text:
- Date Issued: 2012
- Authors: Kadye, Wilbert Takawira
- Date: 2012
- Subjects: Catfishes -- South Africa -- Eastern Cape Biological invasions -- South Africa -- Great Fish River Biological invasions -- South Africa -- Sundays River Clarias gariepinus Freshwater ecology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5227 , http://hdl.handle.net/10962/d1005070
- Description: Invasive species are of particular concern as they have the potential to alter community structure and food web relationships within their invaded habitats. African sharptooth catfish Clarias gariepinus, a generalist predator, was introduced through an inter-basin water transfer scheme into the Great Fish and Sundays Rivers, Eastern Cape, South Africa, where it threatens the native riverine biota. This thesis assessed its impact from a trophic perspective. Patterns in catfish distribution and abundance revealed an upstream to downstream gradient that was associated with spatial distribution of most species within the mainstream, and a mainstream to tributary gradient that was associated with the spatial distribution of native minnows. The catfish was predicted to occur widely within the mainstem habitats and to decrease progressively along the mainstrem to tributary gradient with the physico-chemical environment being a good proxy for predicting both its occurrence and abundance. The results suggest the catfish proliferated within mainstem habitats where invasion resistance was possibly reduced due to alteration of flow. Population dynamics and size structuring of two native cyprinid minnows Pseudobarbus afer and Barbus anoplus, threatened by catfish, were examined within uninvaded headwater streams in relation to their proximate physical habitats. Their habitats were characterised by seasonal variation in physico-chemical conditions and a spatial variation in substrata compositions. No evidence of differences was found between seasons for density and capture probability for either species. The population size and density for P. afer was found to increase with increasing proportion of boulders. In comparison, B. anoplus population size and probability of capture increased with increasing proportion of bedrock and bank vegetation, respectively. Size structuring was explained predominantly by seasonality and habitat variables for P. afer and B. anoplus, respectively. Stable isotope ratios of carbon and nitrogen were used to compare the spatial variation in both the community-wide and catfish-specific niches and to estimate catfish prey sources from different habitats within the invaded systems. Aquatic community and catfish niches were statistically different among localities, suggesting that each locality had a distinct community-wide trophic structure. Dispersion metrics indicated no evidence of differences in the clustering among individuals, but provided evidence of differences in path trajectories for the comparisons of catfish populations that suggested dietary plasticity within different localities. Dietary studies revealed both ontogenetic shift and omnivory that suggested that catfish may exhibit less pronounced top-down effects within its invaded habitats. Manipulative experiments were used to test the response of benthic macroinvertebrates within two rivers that were differentially impacted by catfish as a presstype disturbance. Macroinvertebrates were non-responsive to catfish presence within a system where catfish had previously been established. In contrast, excluding catfish in this system indicated a response that suggested the importance of refuge within invaded habitats and the possible recovery pattern of certain macroinvertebrate taxa. By comparison, introduction of catfish within previously uninvaded localities provided evidence of direct catfish impact through elimination of conspicuous taxa. Acoustic telemetry was used to investigate catfish movement patterns within an invaded lentic habitat and provided evidence that habitat utilisation was non-random. The shallow and structured river mouth habitat, which was most utilised, was probably the most ideal for its breeding and feeding. This inferred potential overlap with native species and suggested the risk of predation and competitive interference. Catfish also exhibited both nocturnal and diurnal activity patterns that were probably related to feeding.
- Full Text:
- Date Issued: 2012
Electrospun nanofibers : an alternative sorbent material for solid phase extraction
- Chigome, Samuel, Samuel Chigome
- Authors: Chigome, Samuel , Samuel Chigome
- Date: 2012 , 2012-03-26
- Subjects: Nanofibers -- Research Electrospinning -- Research Sorbents -- Research Extraction (Chemistry) -- Research
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4314 , http://hdl.handle.net/10962/d1004972
- Description: The work described in the thesis seeks to lay a foundation for a better understanding of the use of electrospun nanofibers as a sorbent material. Three miniaturised electrospun nanofiber based solid phase extraction devices were fabricated. For the first two, 10 mg of electrospun polystyrene fibers were used as a sorbent bed for a micro column SPE device (8 mm bed height in a 200 μl pipette tip) and a disk (I) SPE device (5 mm 1 mm sorbent bed in a 1000 μl SPE barrel). While for the third, 4.6 mg of electrospun nylon nanofibers were used as a sorbent bed for a disk (II) SPE device, (sorbent bed consisting of 5 5 mm 350 μm stacked disks in a 500 μl SPE barrel). Corticosteroids were employed as model analytes for performance evaluation of the fabricated SPE devices. Quantitative recoveries (45.5-124.29 percent) were achieved for all SPE devices at a loading volume of 100 μl and analyte concentration of 500 ng ml-1. Three mathematical models; the Boltzmann, Weibull five parameter and the Sigmoid three parameter were employed to describe the break through profiles of each of the sorbent beds. The micro column SPE device exhibited a breakthrough volume of 1400 μl, and theoretical plates (7.98-9.1) while disk (I) SPE device exhibited 400-500 μl and 1.39-2.82 respectively. Disk (II) SPE device exhibited a breakthrough volume of 200 μl and theoretical plates 0.38-1.15. It was proposed that the formats of future electrospun nanofiber sorbent based SPE devices will be guided by mechanical strength of the polymer. The study classified electrospun polymer fibers into two as polystyrene type (relatively low mechanical strength) and nylon type (relatively high mechanical strength).
- Full Text:
- Date Issued: 2012
- Authors: Chigome, Samuel , Samuel Chigome
- Date: 2012 , 2012-03-26
- Subjects: Nanofibers -- Research Electrospinning -- Research Sorbents -- Research Extraction (Chemistry) -- Research
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4314 , http://hdl.handle.net/10962/d1004972
- Description: The work described in the thesis seeks to lay a foundation for a better understanding of the use of electrospun nanofibers as a sorbent material. Three miniaturised electrospun nanofiber based solid phase extraction devices were fabricated. For the first two, 10 mg of electrospun polystyrene fibers were used as a sorbent bed for a micro column SPE device (8 mm bed height in a 200 μl pipette tip) and a disk (I) SPE device (5 mm 1 mm sorbent bed in a 1000 μl SPE barrel). While for the third, 4.6 mg of electrospun nylon nanofibers were used as a sorbent bed for a disk (II) SPE device, (sorbent bed consisting of 5 5 mm 350 μm stacked disks in a 500 μl SPE barrel). Corticosteroids were employed as model analytes for performance evaluation of the fabricated SPE devices. Quantitative recoveries (45.5-124.29 percent) were achieved for all SPE devices at a loading volume of 100 μl and analyte concentration of 500 ng ml-1. Three mathematical models; the Boltzmann, Weibull five parameter and the Sigmoid three parameter were employed to describe the break through profiles of each of the sorbent beds. The micro column SPE device exhibited a breakthrough volume of 1400 μl, and theoretical plates (7.98-9.1) while disk (I) SPE device exhibited 400-500 μl and 1.39-2.82 respectively. Disk (II) SPE device exhibited a breakthrough volume of 200 μl and theoretical plates 0.38-1.15. It was proposed that the formats of future electrospun nanofiber sorbent based SPE devices will be guided by mechanical strength of the polymer. The study classified electrospun polymer fibers into two as polystyrene type (relatively low mechanical strength) and nylon type (relatively high mechanical strength).
- Full Text:
- Date Issued: 2012
The role of bank finance in small firm growth : a case study
- Authors: Musengi, Sandra
- Date: 2003
- Subjects: Banks and banking -- South Africa , Finance -- South Africa , Small business -- South Africa -- Finance , Small business -- South Africa -- Growth -- Case studies , Entrepreneurship -- South Africa , New business enterprises -- South Africa , Bank loans -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1176 , http://hdl.handle.net/10962/d1002793 , Banks and banking -- South Africa , Finance -- South Africa , Small business -- South Africa -- Finance , Small business -- South Africa -- Growth -- Case studies , Entrepreneurship -- South Africa , New business enterprises -- South Africa , Bank loans -- South Africa
- Description: The debate concerning small firm access to finance continues. The proliferation of research of the issue underlines the importance attached in promoting a strong entrepreneurial culture within a country. Small firms are significant to economic growth if they are growing. Central to this significance is ascertaining the role of finance and in particular bank finance in accelerating small growth potential. The case study, through its ontological, epistemological and methodological position, draws on a document review and interview material from small firm owners and key informants to explore the role of bank finance in small firm growth. Case study evidence reveals that small firm owners do not intend to finance firm growth with bank finance but prefer to finance growth with internally generated funds. The owners indicate that non-financial and behavioural factors, such as, maintaining decision-making control, experience accessing bank finance, the perception of the banking relationship and growth aspirations of owners may be more important in dertermining the finance structure for firm growth. From the bank's perspective, findings suggest that risk assessment, financial viability of the enterprise and provision of collateral are more important in the lending decisions; findings supported by an analysis of selected documents. The small sample of small firm owners, bank representatives, experts and documents makes it difficult to generalize the findings. However, the findings are significant because exploring the issue from different perspectives presents invaluable insights, which can be investigated further to assist small firm owners, to develop finance products geared for small firm operations, and in the development of the knowledge base on finance-related issues in the South African context.
- Full Text:
- Date Issued: 2003
- Authors: Musengi, Sandra
- Date: 2003
- Subjects: Banks and banking -- South Africa , Finance -- South Africa , Small business -- South Africa -- Finance , Small business -- South Africa -- Growth -- Case studies , Entrepreneurship -- South Africa , New business enterprises -- South Africa , Bank loans -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1176 , http://hdl.handle.net/10962/d1002793 , Banks and banking -- South Africa , Finance -- South Africa , Small business -- South Africa -- Finance , Small business -- South Africa -- Growth -- Case studies , Entrepreneurship -- South Africa , New business enterprises -- South Africa , Bank loans -- South Africa
- Description: The debate concerning small firm access to finance continues. The proliferation of research of the issue underlines the importance attached in promoting a strong entrepreneurial culture within a country. Small firms are significant to economic growth if they are growing. Central to this significance is ascertaining the role of finance and in particular bank finance in accelerating small growth potential. The case study, through its ontological, epistemological and methodological position, draws on a document review and interview material from small firm owners and key informants to explore the role of bank finance in small firm growth. Case study evidence reveals that small firm owners do not intend to finance firm growth with bank finance but prefer to finance growth with internally generated funds. The owners indicate that non-financial and behavioural factors, such as, maintaining decision-making control, experience accessing bank finance, the perception of the banking relationship and growth aspirations of owners may be more important in dertermining the finance structure for firm growth. From the bank's perspective, findings suggest that risk assessment, financial viability of the enterprise and provision of collateral are more important in the lending decisions; findings supported by an analysis of selected documents. The small sample of small firm owners, bank representatives, experts and documents makes it difficult to generalize the findings. However, the findings are significant because exploring the issue from different perspectives presents invaluable insights, which can be investigated further to assist small firm owners, to develop finance products geared for small firm operations, and in the development of the knowledge base on finance-related issues in the South African context.
- Full Text:
- Date Issued: 2003
Tolerance as an ethical issue with special reference to South Africa
- Authors: Mnyaka, Mluleki Michael
- Date: 1998
- Subjects: Religious tolerance , Toleration , South Africa -- Constitution
- Language: English
- Type: Thesis , Masters , MTh
- Identifier: vital:1312 , http://hdl.handle.net/10962/d1020852
- Description: From Introduction: It was a feature of South African political life to have senseless and continued political violence especially in areas such as KwaZulu Natal and Gauteng., There were certain places that were demarcated as "no-go areas" in other parts of the country for political rivals* This research has been directed by the cries of many South Africans pleading for political tolerance. Tolerance was a term used by both politicians and ordinary people alike and therefore open to misuse and various interpretations. As a term it was therefore without adequate clarification on its meaning. It is an attempt of this study to clarify and promote this value of tolerance. In Chapter One, the value of tolerance is examined. It is described as putting up with what is disliked or disapproved for the sake of others. But it is deliberate and is therefore a virtue. Positive attitudes, motives and power are central to tolerance. For tolerance to be sustained, solid foundations such as education, respect for others and their freedoms, democracy, justice, stability and reciprocity are to be laid. A light is also being shed on the limits of this virtue. Considerations and circumstances which need to be taken when deciding on each an action are the very motives and conditions for tolerance. This further makes the issue of tolerance to be complex. Church history shows that tolerance does not come naturally. It is a difficulty because of certain principles that are at stake. When viewed from the twentieth century perspective many of Church history's periods were of intolerance because the church had power. Tolerance was an exception, a plea of those without power. South Africa has to unlearn much of intolerance because of the past that militated against tolerance. Fortunately tolerance is now being firmly entrenched as law. Even though it is so, the tension of being tolerant and intolerant still exists especially in the whole area of abortion. Let us examine why tolerance is such a complex issue and a virtue to be promoted.
- Full Text:
- Date Issued: 1998
- Authors: Mnyaka, Mluleki Michael
- Date: 1998
- Subjects: Religious tolerance , Toleration , South Africa -- Constitution
- Language: English
- Type: Thesis , Masters , MTh
- Identifier: vital:1312 , http://hdl.handle.net/10962/d1020852
- Description: From Introduction: It was a feature of South African political life to have senseless and continued political violence especially in areas such as KwaZulu Natal and Gauteng., There were certain places that were demarcated as "no-go areas" in other parts of the country for political rivals* This research has been directed by the cries of many South Africans pleading for political tolerance. Tolerance was a term used by both politicians and ordinary people alike and therefore open to misuse and various interpretations. As a term it was therefore without adequate clarification on its meaning. It is an attempt of this study to clarify and promote this value of tolerance. In Chapter One, the value of tolerance is examined. It is described as putting up with what is disliked or disapproved for the sake of others. But it is deliberate and is therefore a virtue. Positive attitudes, motives and power are central to tolerance. For tolerance to be sustained, solid foundations such as education, respect for others and their freedoms, democracy, justice, stability and reciprocity are to be laid. A light is also being shed on the limits of this virtue. Considerations and circumstances which need to be taken when deciding on each an action are the very motives and conditions for tolerance. This further makes the issue of tolerance to be complex. Church history shows that tolerance does not come naturally. It is a difficulty because of certain principles that are at stake. When viewed from the twentieth century perspective many of Church history's periods were of intolerance because the church had power. Tolerance was an exception, a plea of those without power. South Africa has to unlearn much of intolerance because of the past that militated against tolerance. Fortunately tolerance is now being firmly entrenched as law. Even though it is so, the tension of being tolerant and intolerant still exists especially in the whole area of abortion. Let us examine why tolerance is such a complex issue and a virtue to be promoted.
- Full Text:
- Date Issued: 1998
A comparative study of the Grey-headed Sparrow (Passer griseus L) and the House Sparrow (Passer domesticus L) in Malawi
- Authors: Nhlane, Martin Edwin Darwin
- Date: 1997
- Subjects: English sparrow Sparrows
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5654 , http://hdl.handle.net/10962/d1005337
- Description: The House Sparrow Passer domesticus, an introduced species, and the Grey-headed Sparrow Passer griseus, an indigenous species, are sympatric in Malawi. Their distribution in the country and any possible interactions were studied, principally in southern Malawi. A morphological analysis of museum specimens confirmed that grey-headed sparrows in Malawi belong to the Northern Grey-headed Sparrow Passer griseus as distinct from the Southern Grey-headed Sparrow Passer diffusus. This species was widely distributed in the, country in association with human dwellings, both in rural areas as well as urban centres. In the northern region Greyheaded Sparrows were more abundant in the urban centres than rural areas, but in the central and southern regions numbers in the rural and urban areas were more or less the same. In Blantyre City, where they are in sympatry with the House Sparrow, they were found in the low density and industrial areas and were absent from the high density areas. The House Sparrow, arrived in Malawi in 1967 at Chileka in the southern region. Since then it has spread northwards, moving from the southern to the central and northern regions. House Sparrow numbers were found to be progressively larger in the southern region and lowest in the northern region. House Sparrows were found at sites where food was readily available, as in the immediate vicinity of houses. In the central and northern regions they were restricted mainly to urban areas. In the southern region, they occur both in rural and urban areas, probably as a reflection of the larger period of colonization in the south. In the northern region their movement has apparently been restricted by geographical barriers. In Blantyre City Grey-headed Sparrows preferred areas where tree density was high and house density was low, while House Sparrows preferred areas where house density was high and tree density was low. There was a positive correlation between Greyheaded Sparrow numbers and tree density and a negative correlation with house density. House Sparrow abundance was negatively correlated with tree density and positively correlated with house density. Grey-headed Sparrows bred in the rainy season, whereas House Sparrows bred throughout the year. There were differences in nest site selection: Grey-headed Sparrows used artificial structures such as fencing poles, and wooden telephone or electricity poles. The House Sparrow used mostly buildings and nested in crevices, holes in walls and between the walls and rafters. Nest height also differed- Grey-headed Sparrows nested at heights ranging from 1 - 8 m while House Sparrow nests were at heights of 1 - 5 m. Moult data suggests that although the House Sparrows breed throughout the year, they moult at a particular time of the year when breeding is less common. Grey-headed Sparrows were found to moult mainly from May to September in southern Africa and from June to September in central Africa. In both cases the breeding season extends over a similar period from about October to April/May of the following year. Peak moult periods differed between the House Sparrows and Grey-headed Sparrows. House Sparrows moulted mainly in the first half of the year, and Greyheaded Sparrows in the second six months. The clutch sizes of the two species were similar (mean 3.9 eggs for the House Sparrow and 3.4 for the Grey-headed Sparrow). The clutch size of the House Sparrow varied seasonally and was larger from November to May. The average incubation period for the House Sparrow was 11.5 days and the fledging period 15.4 days. The Grey-headed Sparrow fledging period was 14.7 days. Chick mortality of the House Sparrow at Chikunda farm was attributed to starvation resulting from brood reduction, abandonment, predation, low birth weight, accidental deaths and parasitism by fly larvae. Both Grey-headed and House Sparrows fed their young on insect food. Male House Sparrows fed actively initially, but their contribution declined from about day five onwards. In the Grey-headed Sparrow, both parents fed their young equally throughout the nestling period. House Sparrows fed on the ground near houses; Grey-headed Sparrows fed both on the ground away from houses and in tree canopies. The Grey-headed Sparrow walked as it fed on the ground as opposed to the House sparrow which hopped. Grey-headed Sparrows fed mainly as pairs and singletons while House Sparrows fed as family groups. Larger feeding groups of Grey-headed Sparrows were seen in the northern region at areas where food was plentiful. Where the two sparrows were seen feeding together, there was no direct competition for food. Where individual distance was violated; male House Sparrows displaced Grey-headed Sparrows which landed too close to them. Overall it appears that the distribution of the two species is determined more by their responses to habitat conditions than by interspecific interactions.
- Full Text:
- Date Issued: 1997
- Authors: Nhlane, Martin Edwin Darwin
- Date: 1997
- Subjects: English sparrow Sparrows
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5654 , http://hdl.handle.net/10962/d1005337
- Description: The House Sparrow Passer domesticus, an introduced species, and the Grey-headed Sparrow Passer griseus, an indigenous species, are sympatric in Malawi. Their distribution in the country and any possible interactions were studied, principally in southern Malawi. A morphological analysis of museum specimens confirmed that grey-headed sparrows in Malawi belong to the Northern Grey-headed Sparrow Passer griseus as distinct from the Southern Grey-headed Sparrow Passer diffusus. This species was widely distributed in the, country in association with human dwellings, both in rural areas as well as urban centres. In the northern region Greyheaded Sparrows were more abundant in the urban centres than rural areas, but in the central and southern regions numbers in the rural and urban areas were more or less the same. In Blantyre City, where they are in sympatry with the House Sparrow, they were found in the low density and industrial areas and were absent from the high density areas. The House Sparrow, arrived in Malawi in 1967 at Chileka in the southern region. Since then it has spread northwards, moving from the southern to the central and northern regions. House Sparrow numbers were found to be progressively larger in the southern region and lowest in the northern region. House Sparrows were found at sites where food was readily available, as in the immediate vicinity of houses. In the central and northern regions they were restricted mainly to urban areas. In the southern region, they occur both in rural and urban areas, probably as a reflection of the larger period of colonization in the south. In the northern region their movement has apparently been restricted by geographical barriers. In Blantyre City Grey-headed Sparrows preferred areas where tree density was high and house density was low, while House Sparrows preferred areas where house density was high and tree density was low. There was a positive correlation between Greyheaded Sparrow numbers and tree density and a negative correlation with house density. House Sparrow abundance was negatively correlated with tree density and positively correlated with house density. Grey-headed Sparrows bred in the rainy season, whereas House Sparrows bred throughout the year. There were differences in nest site selection: Grey-headed Sparrows used artificial structures such as fencing poles, and wooden telephone or electricity poles. The House Sparrow used mostly buildings and nested in crevices, holes in walls and between the walls and rafters. Nest height also differed- Grey-headed Sparrows nested at heights ranging from 1 - 8 m while House Sparrow nests were at heights of 1 - 5 m. Moult data suggests that although the House Sparrows breed throughout the year, they moult at a particular time of the year when breeding is less common. Grey-headed Sparrows were found to moult mainly from May to September in southern Africa and from June to September in central Africa. In both cases the breeding season extends over a similar period from about October to April/May of the following year. Peak moult periods differed between the House Sparrows and Grey-headed Sparrows. House Sparrows moulted mainly in the first half of the year, and Greyheaded Sparrows in the second six months. The clutch sizes of the two species were similar (mean 3.9 eggs for the House Sparrow and 3.4 for the Grey-headed Sparrow). The clutch size of the House Sparrow varied seasonally and was larger from November to May. The average incubation period for the House Sparrow was 11.5 days and the fledging period 15.4 days. The Grey-headed Sparrow fledging period was 14.7 days. Chick mortality of the House Sparrow at Chikunda farm was attributed to starvation resulting from brood reduction, abandonment, predation, low birth weight, accidental deaths and parasitism by fly larvae. Both Grey-headed and House Sparrows fed their young on insect food. Male House Sparrows fed actively initially, but their contribution declined from about day five onwards. In the Grey-headed Sparrow, both parents fed their young equally throughout the nestling period. House Sparrows fed on the ground near houses; Grey-headed Sparrows fed both on the ground away from houses and in tree canopies. The Grey-headed Sparrow walked as it fed on the ground as opposed to the House sparrow which hopped. Grey-headed Sparrows fed mainly as pairs and singletons while House Sparrows fed as family groups. Larger feeding groups of Grey-headed Sparrows were seen in the northern region at areas where food was plentiful. Where the two sparrows were seen feeding together, there was no direct competition for food. Where individual distance was violated; male House Sparrows displaced Grey-headed Sparrows which landed too close to them. Overall it appears that the distribution of the two species is determined more by their responses to habitat conditions than by interspecific interactions.
- Full Text:
- Date Issued: 1997
HPLC analysis and pharmacokinetics of cyclizine
- Authors: Walker, Roderick Bryan
- Date: 1995
- Subjects: High performance liquid chromatography Piperazine Pharmacokinetics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3801 , http://hdl.handle.net/10962/d1003279
- Description: The investigations detailed in this dissertation have been conducted to address the paucity of pharmacokinetic information, in published literature, pertaining to cyclizine. The areas of investigation have included the selective quantitation of both cyclizine and its demethylated metabolite, norcyclizine in serum and urine, assessment of stability of both compounds in stored biological samples, dosage form analysis, dissolution rate testing of tablets, and bioavailability and pharmacokinetics following administration of an intravenous solution, and tablets to humans. High-performance liquid chromatography (HPLC) was used as the main analytical technique throughout these studies. An original HPLC method employing ultraviolet detection with a limit of quantitation of 5μg/ℓ was developed for the determination of cyclizine in serum and both cyclizine and norcyclizine in urine, Solid-phase extraction using extraction columns packed with reversed-phase C18 material, and followed by a simple phase-separation step proved successful for the accurate and precise isolation of the compounds. The validated method was applied to the analysis of serum and urine samples from a pilot study in which a single volunteer was administered 50mg of cyclizine hydrochloride. Several samples collected during the pilot study revealed the presence of both drug and metabolite in concentrations below the limit of detection. In order to improve the selectivity and sensitivity of the analytical method an HPLC method with electrochemical detection operating in the "oxidative-screen" mode was developed. The solid-phase extraction procedure was modified slightly and the method found to be precise, accurate, selective and highly sensitive with a limit of quantitation of Iμg/g/l for both cyclizine and norcyclizine in both serum and urine. This method was applied to the determination of both compounds after intravenous and oral administration of cyclizine to humans. HPLC with electrochemical detection was used for the analysis of samples collected during dissolution studies on the batch of tablets used for pharmacokinetic studies. In addition, this method was used to assess content uniformity of the tablets and of samples from the batch of intravenous ampoules of cyclizine lactate. Dissolution studies showed that all tablets tested passed the compendial specifications for cyclizine. Content uniformity assessment revealed that within-batch uniformity existed for both the tablets and ampoules and, therefore, variations in pharmacokinetic parameters for the drug would more than likely be as a result of inter- and intra-individual variability within the subject population. Pharmacokinetic information for cyclizine was obtained following administration of an intravenous bolus dose of cyclizine lactate as a solution, oral administration of cyclizine hydrochloride as a single dose of 50mg and as fixed multiple doses of 50mg every 8 hours for five days. Further information was acquired following administration of single doses of 100mg and 150mg cyclizine hydrochloride. Data collected from these studies were evaluated using both compartmental and non-compartmental techniques. Cyclizine was rapidly absorbed following oral administration with mean kₐ = 1.54 hr⁻¹ and was found to have an absolute bioavailability (F) of 0.47. The presence of norcyclizine in serum following oral and not intravenous dosing suggests cyclizine is susceptible to "first-pass" metabolism in either the gut wall or the I iver. Mean ClTOT determined following the intravenous dose was 0.865 ℓ/hr/kg. The mean ClTOT of 0.823 ℓ/hr/kg calculated following oral dosing, using a unique value of F for each subject compared favourahly with that obtained following intravenous dosing. Renal clearance of cyclizine is negligihle indicating that non-renal routes of elimination account for the majority of removal of cyclizine form the body. Cyclizine is extensively distributed and the mean Vz following an intravenous dose was 16.70 ℓ/kg. This value is lower than that calculated from all oral studies from which the mean Vz was determined to be 25.74 ℓ/kg. Cyclizine is eliminated slowly with a mean elimination t½ = 20.11 hours. Cyclizine dose not appear to follow dosedependent kinetics and therefore, inability to predict steady state levels are more than likely due to accumulation as a result of frequent dosing rather than saturation of elimination mechanisms. Modelling of intravenous data to one-compartment (lBCM), two-compartment (2BCM) and threecompartment models indicated that the pharmacokinetics of cyclizine can be adequately described by a 3BCM. The drug is rapidly distributed into a "shallow" peripheral compartment (α = 9.44 hr⁻¹ , and k₂₁ = 2.09 hr⁻¹ ), and slowly distributed to the "deep" peripheral compartment (β = 0.451 hr⁻¹ and k₃₁ = 0.120 hr⁻¹ ). Modelling of all oral data indicated that a 2BCM best described the pharmacokinetics of the drug, however, distribution to the peripheral compartment is not as rapid as to the "shallow" peripheral compartment following the intravenous dose. Mean distribution parameters were α = 0.64 hr⁻¹1 and, k₂₁ = 0.39 hr⁻¹. Mean CITOT following intravenous dosing of 0.70 ℓ/hr/kg was similar to the mean CIToT of 0.73 ℓ/hr/kg determined after oral dosing. The mean distribution volume at steady state determined following intravenous dosing (17.78 ℓ/kg) was lower than that obtained from the oral studies (25.52 ℓ/kg). The mean terminal elimination half-lives calculated for cyclizine following fitting of intravenous and oral data was 25.09 hours. In general, mean pharmacokinetic parameters calculated following titting of data to a 2BCM after oral administration correlate closely with those calculated using non-compartmental techniques. However, the pharmacokinetics following intravenous dosing are better described by a 3BCM and a close correlation between parameters estimated using noncompartmental techniques and compartmental techniques is evident when a 3BCM model is used.
- Full Text:
- Date Issued: 1995
- Authors: Walker, Roderick Bryan
- Date: 1995
- Subjects: High performance liquid chromatography Piperazine Pharmacokinetics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3801 , http://hdl.handle.net/10962/d1003279
- Description: The investigations detailed in this dissertation have been conducted to address the paucity of pharmacokinetic information, in published literature, pertaining to cyclizine. The areas of investigation have included the selective quantitation of both cyclizine and its demethylated metabolite, norcyclizine in serum and urine, assessment of stability of both compounds in stored biological samples, dosage form analysis, dissolution rate testing of tablets, and bioavailability and pharmacokinetics following administration of an intravenous solution, and tablets to humans. High-performance liquid chromatography (HPLC) was used as the main analytical technique throughout these studies. An original HPLC method employing ultraviolet detection with a limit of quantitation of 5μg/ℓ was developed for the determination of cyclizine in serum and both cyclizine and norcyclizine in urine, Solid-phase extraction using extraction columns packed with reversed-phase C18 material, and followed by a simple phase-separation step proved successful for the accurate and precise isolation of the compounds. The validated method was applied to the analysis of serum and urine samples from a pilot study in which a single volunteer was administered 50mg of cyclizine hydrochloride. Several samples collected during the pilot study revealed the presence of both drug and metabolite in concentrations below the limit of detection. In order to improve the selectivity and sensitivity of the analytical method an HPLC method with electrochemical detection operating in the "oxidative-screen" mode was developed. The solid-phase extraction procedure was modified slightly and the method found to be precise, accurate, selective and highly sensitive with a limit of quantitation of Iμg/g/l for both cyclizine and norcyclizine in both serum and urine. This method was applied to the determination of both compounds after intravenous and oral administration of cyclizine to humans. HPLC with electrochemical detection was used for the analysis of samples collected during dissolution studies on the batch of tablets used for pharmacokinetic studies. In addition, this method was used to assess content uniformity of the tablets and of samples from the batch of intravenous ampoules of cyclizine lactate. Dissolution studies showed that all tablets tested passed the compendial specifications for cyclizine. Content uniformity assessment revealed that within-batch uniformity existed for both the tablets and ampoules and, therefore, variations in pharmacokinetic parameters for the drug would more than likely be as a result of inter- and intra-individual variability within the subject population. Pharmacokinetic information for cyclizine was obtained following administration of an intravenous bolus dose of cyclizine lactate as a solution, oral administration of cyclizine hydrochloride as a single dose of 50mg and as fixed multiple doses of 50mg every 8 hours for five days. Further information was acquired following administration of single doses of 100mg and 150mg cyclizine hydrochloride. Data collected from these studies were evaluated using both compartmental and non-compartmental techniques. Cyclizine was rapidly absorbed following oral administration with mean kₐ = 1.54 hr⁻¹ and was found to have an absolute bioavailability (F) of 0.47. The presence of norcyclizine in serum following oral and not intravenous dosing suggests cyclizine is susceptible to "first-pass" metabolism in either the gut wall or the I iver. Mean ClTOT determined following the intravenous dose was 0.865 ℓ/hr/kg. The mean ClTOT of 0.823 ℓ/hr/kg calculated following oral dosing, using a unique value of F for each subject compared favourahly with that obtained following intravenous dosing. Renal clearance of cyclizine is negligihle indicating that non-renal routes of elimination account for the majority of removal of cyclizine form the body. Cyclizine is extensively distributed and the mean Vz following an intravenous dose was 16.70 ℓ/kg. This value is lower than that calculated from all oral studies from which the mean Vz was determined to be 25.74 ℓ/kg. Cyclizine is eliminated slowly with a mean elimination t½ = 20.11 hours. Cyclizine dose not appear to follow dosedependent kinetics and therefore, inability to predict steady state levels are more than likely due to accumulation as a result of frequent dosing rather than saturation of elimination mechanisms. Modelling of intravenous data to one-compartment (lBCM), two-compartment (2BCM) and threecompartment models indicated that the pharmacokinetics of cyclizine can be adequately described by a 3BCM. The drug is rapidly distributed into a "shallow" peripheral compartment (α = 9.44 hr⁻¹ , and k₂₁ = 2.09 hr⁻¹ ), and slowly distributed to the "deep" peripheral compartment (β = 0.451 hr⁻¹ and k₃₁ = 0.120 hr⁻¹ ). Modelling of all oral data indicated that a 2BCM best described the pharmacokinetics of the drug, however, distribution to the peripheral compartment is not as rapid as to the "shallow" peripheral compartment following the intravenous dose. Mean distribution parameters were α = 0.64 hr⁻¹1 and, k₂₁ = 0.39 hr⁻¹. Mean CITOT following intravenous dosing of 0.70 ℓ/hr/kg was similar to the mean CIToT of 0.73 ℓ/hr/kg determined after oral dosing. The mean distribution volume at steady state determined following intravenous dosing (17.78 ℓ/kg) was lower than that obtained from the oral studies (25.52 ℓ/kg). The mean terminal elimination half-lives calculated for cyclizine following fitting of intravenous and oral data was 25.09 hours. In general, mean pharmacokinetic parameters calculated following titting of data to a 2BCM after oral administration correlate closely with those calculated using non-compartmental techniques. However, the pharmacokinetics following intravenous dosing are better described by a 3BCM and a close correlation between parameters estimated using noncompartmental techniques and compartmental techniques is evident when a 3BCM model is used.
- Full Text:
- Date Issued: 1995
An evaluation of case study teaching materials on hazards: based on the current aims of geographical education
- Authors: Pyle, Desmond Mark
- Date: 1994
- Subjects: Geography -- Study and teaching (Secondary) -- South Africa Disasters -- Study and teaching -- South Africa Hazardous geographic environments -- Study and teaching (Secondary) -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1524 , http://hdl.handle.net/10962/d1003406
- Description: Hazards are an integral part of people-environment relationships. The impact of hazards locally and globally has become increasinglymore severe. particularly in the previous two decades. This is largely as a result of unwise human intervention in natural systems. The study of hazards at secondary school level affords valuable opportunities for learning about people-environment issues. This in turn, can promote a greater awareness of environmental problems. One of the most important current aims of Geographical Education is the development of critical thinking skills in pupils. Such skills are vital for equipping pupils with the necessary tools to understand and participate in solving the world's increasing human and environmental problems. The development of a critical faculty in pupils is best achieved by the use of learner-based participatory teaching strategies where pupils are involved in problem solving activities. Research has shown that British and South African Geography curricula reflect current thinking in Geographical education and learning theory. The 1992 Junior Secondary Geography Syllabus in line with these trends. includes a section for study on hazards. Hazards are presented primarily as case studies in modern Geographical texts. which is seen as one of the most effective ways of teaching hazards. Research however suggests that South African textbooks have certain shortcomings. notwithstanding the importance placed on textbooks by teachers in this country. This study investigated the extent to which case study teaching materials on hazards are optimising opportunities available for effective learning within an Environmental Paradigm. An evaluation methodology, which is believed to have value for use by other researchers, was developed to suit the specific requirements of the study. The study findings reveal a poor realisation of the current aims of Geographical Education and learning theory, regarding the South African teaching materials. Recommendations are made improvements in the development and use of local case teaching materials. Guidelines for the development of for study local materials are provided from case studies in British texts and from methods developed by the researcher.
- Full Text:
- Date Issued: 1994
- Authors: Pyle, Desmond Mark
- Date: 1994
- Subjects: Geography -- Study and teaching (Secondary) -- South Africa Disasters -- Study and teaching -- South Africa Hazardous geographic environments -- Study and teaching (Secondary) -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1524 , http://hdl.handle.net/10962/d1003406
- Description: Hazards are an integral part of people-environment relationships. The impact of hazards locally and globally has become increasinglymore severe. particularly in the previous two decades. This is largely as a result of unwise human intervention in natural systems. The study of hazards at secondary school level affords valuable opportunities for learning about people-environment issues. This in turn, can promote a greater awareness of environmental problems. One of the most important current aims of Geographical Education is the development of critical thinking skills in pupils. Such skills are vital for equipping pupils with the necessary tools to understand and participate in solving the world's increasing human and environmental problems. The development of a critical faculty in pupils is best achieved by the use of learner-based participatory teaching strategies where pupils are involved in problem solving activities. Research has shown that British and South African Geography curricula reflect current thinking in Geographical education and learning theory. The 1992 Junior Secondary Geography Syllabus in line with these trends. includes a section for study on hazards. Hazards are presented primarily as case studies in modern Geographical texts. which is seen as one of the most effective ways of teaching hazards. Research however suggests that South African textbooks have certain shortcomings. notwithstanding the importance placed on textbooks by teachers in this country. This study investigated the extent to which case study teaching materials on hazards are optimising opportunities available for effective learning within an Environmental Paradigm. An evaluation methodology, which is believed to have value for use by other researchers, was developed to suit the specific requirements of the study. The study findings reveal a poor realisation of the current aims of Geographical Education and learning theory, regarding the South African teaching materials. Recommendations are made improvements in the development and use of local case teaching materials. Guidelines for the development of for study local materials are provided from case studies in British texts and from methods developed by the researcher.
- Full Text:
- Date Issued: 1994
School guidance and counselling in Natal : present realities and future possibilities
- Authors: Naicker, Dhanasagaran
- Date: 1993
- Subjects: Educational counseling -- South Africa Counseling -- Vocational guidance -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1758 , http://hdl.handle.net/10962/d1003643
- Description: School guidance and counselling is a programme that is complementary to the education process and is seen as a support service for the pupil. However, owing to the apartheid policies of the South African government, all pupils did not have equal access to guidance services. In a post-apartheid South Africa it is anticipated that a unitary education system would emerge to provide equal access to education for all South African pupils and this implies that previous imbalances that existed would have to be addressed. In this study the present state of guidance and counselling services in Natal was investigated and policy options to redress past inequities and to make school guidance and counselling services a reality for all South African pupils, within the context of limited resources were explored.
- Full Text:
- Date Issued: 1993
- Authors: Naicker, Dhanasagaran
- Date: 1993
- Subjects: Educational counseling -- South Africa Counseling -- Vocational guidance -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1758 , http://hdl.handle.net/10962/d1003643
- Description: School guidance and counselling is a programme that is complementary to the education process and is seen as a support service for the pupil. However, owing to the apartheid policies of the South African government, all pupils did not have equal access to guidance services. In a post-apartheid South Africa it is anticipated that a unitary education system would emerge to provide equal access to education for all South African pupils and this implies that previous imbalances that existed would have to be addressed. In this study the present state of guidance and counselling services in Natal was investigated and policy options to redress past inequities and to make school guidance and counselling services a reality for all South African pupils, within the context of limited resources were explored.
- Full Text:
- Date Issued: 1993
The responses of standard nine pupils to valuing strategies in geography
- Authors: Nyikana, Nqabomzi
- Date: 1989
- Subjects: Geography -- Study and teaching (Secondary) -- South Africa , Critical thinking
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1380 , http://hdl.handle.net/10962/d1001446
- Description: Values education in geography can be seen as a way of educating pupils to think critically and independently on matters to which they can readily relate. It also involves the relating of facts and concepts of a subject area to the pupils ' own lives. There is, therefore, a need to introduce values education in geography at our schools. The DET geography syllabuses offer many topics of social and environmental concern. Valuing processes, based on values analysis and values clarification, can be used to teach these topics. Through values education, geography pupils can become more purposeful, more enthusiastic and positive in their learning. This study investigates the effectiveness of valuing strategies in the teaching of geography. A broad overview of the literature on valuing in general and valuing in geographical education in particular, was analysed. Three teaching units were then devised and tried out in KwaZulu schools. The responses of pupils to these units were then investigated through questionnaires. Teachers were also interviewed to find the extent to which valuing approaches were being used. The principal findings of the study are, firstly, that the pupils responded well to the valuing units. Secondly, that teachers were not using valuing strategies in schools and, lastly, that the units in the research could be effective in teaching values geography. From the findings of this research, it is evident that values geography has an important place in the South African school curriculum
- Full Text:
- Date Issued: 1989
- Authors: Nyikana, Nqabomzi
- Date: 1989
- Subjects: Geography -- Study and teaching (Secondary) -- South Africa , Critical thinking
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1380 , http://hdl.handle.net/10962/d1001446
- Description: Values education in geography can be seen as a way of educating pupils to think critically and independently on matters to which they can readily relate. It also involves the relating of facts and concepts of a subject area to the pupils ' own lives. There is, therefore, a need to introduce values education in geography at our schools. The DET geography syllabuses offer many topics of social and environmental concern. Valuing processes, based on values analysis and values clarification, can be used to teach these topics. Through values education, geography pupils can become more purposeful, more enthusiastic and positive in their learning. This study investigates the effectiveness of valuing strategies in the teaching of geography. A broad overview of the literature on valuing in general and valuing in geographical education in particular, was analysed. Three teaching units were then devised and tried out in KwaZulu schools. The responses of pupils to these units were then investigated through questionnaires. Teachers were also interviewed to find the extent to which valuing approaches were being used. The principal findings of the study are, firstly, that the pupils responded well to the valuing units. Secondly, that teachers were not using valuing strategies in schools and, lastly, that the units in the research could be effective in teaching values geography. From the findings of this research, it is evident that values geography has an important place in the South African school curriculum
- Full Text:
- Date Issued: 1989
Les elements dramatiques dans les premiers romans (1939-1963) de Nathalie Sarraute
- Authors: O'Grady, Betty
- Date: 1983
- Subjects: Sarraute, Nathalie -- Criticism and interpretation , French fiction -- 20th century -- History and criticism
- Language: French
- Type: Thesis , Masters , MA
- Identifier: vital:3617 , http://hdl.handle.net/10962/d1006921 , Sarraute, Nathalie -- Criticism and interpretation , French fiction -- 20th century -- History and criticism
- Full Text:
- Date Issued: 1983
- Authors: O'Grady, Betty
- Date: 1983
- Subjects: Sarraute, Nathalie -- Criticism and interpretation , French fiction -- 20th century -- History and criticism
- Language: French
- Type: Thesis , Masters , MA
- Identifier: vital:3617 , http://hdl.handle.net/10962/d1006921 , Sarraute, Nathalie -- Criticism and interpretation , French fiction -- 20th century -- History and criticism
- Full Text:
- Date Issued: 1983
Theories of economic underdevelopment: a general equilibrium analysis
- Authors: Black, Philip Andrew
- Date: 1982
- Subjects: Equilibrium (Economics) -- Mathematical models Economic development -- Mathematical models Developing countries -- Economic conditions -- Mathematical models
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1049 , http://hdl.handle.net/10962/d1006235
- Description: This thesis is mainly concerned with the question whether 'conventional' economic theory - especially the neoclassical theory of general equilibrium - is sufficiently flexible to accommodate the particular conditions prevailing in the developing countries. It is argued that most existing theories of economic underdevelopment adopt an interpretative approach which essentially amounts to relaxing some of the chief assumptions of the neoclassical theory. When applied to the two-sector model of general equilibrium, these theories generally yield predictions which are vastly different from those associated with the neoclassical assumptions of perfect competition, unlimited factor substitutability and unrestricted resource mobility. Several theories seek to explain the development problem in terms of the specific production processes used in poor countries. Myrdal's (1957) theory of cumulative causation, for example, effectively introduces increasing returns to scale in at least one sector or region of the economy; in contrast to the neoclassical theory, he thus nvisages a cumulative process of regional divergence in the output level per worker. Similarly, Richard Eckaus's (1955) explanation of the "factor-proportions problem" is based on the assumption of limited factor substitutability. This enables him to establish the existence of a so-called "unemployment equiIibrium", thus implying that developing countries may be faced with a conflict between the objective of maximizing social -welfare on the one hand, and that of full employment on the other. More recently, Leibenstein (1960) has shown that this trade-off may be complicated by the introduction of capital-biased technological inventions and innovations. The solution to the factor-proportions problem consists in the adoption of more appropriate, usually labour-biased technologies, increased capital formation and a reduction in the rate of population growth. Much of the postwar literature on economic development has focused on the imperfectly competitive structure of the product and the factor markets in developing countries. Myint (1954) has highlighted the role played by monopolies and ligopolies during the "opening-up" process of economic development. Likewise, both Lewis's (1954) dualist theory and Todaro's (1969; 1971) model of rural-urban migration attempt to explain the unemployment problem in terms of various factor price distortions. In an international context, Prebisch (1950; 1959) and Singer (1950) have again shown how prevailing differences in the structure of markets between developed and developing countries may turn the terms of trade against the latter; using a two-sector model, Bhagwati (1958) has demonstrated that such a deterioration in the terms of trade could bring about a net decrease in the welfare level of the countries concerned. Generally, the policy measures relevant to the "market imperfections" problem include the creation of job opportunities in the rural (rather than urban) sector, the encouragement of informal-sector enterprises,and the imposition of factor taxes and subsidies as a means of counteracting the adverse effect of factor price distortions on employment. A more recent approach to the unemployment problem is the plea by the International Labor Office (1970; 1972) for a redistribution of income within the developing countries. In terms of the two-sector model, such a policy may well succeed in eliminating labour unemployment caused by fixed factor proportions and/or factor price distortions. It should be realized, though, that a redistribution of income may lower the aggregate savings level, and hence also the growth rates of capital and labour employment in the economy. On the whole, it would seem that these theories do indeed adopt a modified version of the neoclassical theory in providing a fairly comprehensive explanation of the economic problems of labour unemployment, low incomes and inequality.
- Full Text:
- Date Issued: 1982
- Authors: Black, Philip Andrew
- Date: 1982
- Subjects: Equilibrium (Economics) -- Mathematical models Economic development -- Mathematical models Developing countries -- Economic conditions -- Mathematical models
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1049 , http://hdl.handle.net/10962/d1006235
- Description: This thesis is mainly concerned with the question whether 'conventional' economic theory - especially the neoclassical theory of general equilibrium - is sufficiently flexible to accommodate the particular conditions prevailing in the developing countries. It is argued that most existing theories of economic underdevelopment adopt an interpretative approach which essentially amounts to relaxing some of the chief assumptions of the neoclassical theory. When applied to the two-sector model of general equilibrium, these theories generally yield predictions which are vastly different from those associated with the neoclassical assumptions of perfect competition, unlimited factor substitutability and unrestricted resource mobility. Several theories seek to explain the development problem in terms of the specific production processes used in poor countries. Myrdal's (1957) theory of cumulative causation, for example, effectively introduces increasing returns to scale in at least one sector or region of the economy; in contrast to the neoclassical theory, he thus nvisages a cumulative process of regional divergence in the output level per worker. Similarly, Richard Eckaus's (1955) explanation of the "factor-proportions problem" is based on the assumption of limited factor substitutability. This enables him to establish the existence of a so-called "unemployment equiIibrium", thus implying that developing countries may be faced with a conflict between the objective of maximizing social -welfare on the one hand, and that of full employment on the other. More recently, Leibenstein (1960) has shown that this trade-off may be complicated by the introduction of capital-biased technological inventions and innovations. The solution to the factor-proportions problem consists in the adoption of more appropriate, usually labour-biased technologies, increased capital formation and a reduction in the rate of population growth. Much of the postwar literature on economic development has focused on the imperfectly competitive structure of the product and the factor markets in developing countries. Myint (1954) has highlighted the role played by monopolies and ligopolies during the "opening-up" process of economic development. Likewise, both Lewis's (1954) dualist theory and Todaro's (1969; 1971) model of rural-urban migration attempt to explain the unemployment problem in terms of various factor price distortions. In an international context, Prebisch (1950; 1959) and Singer (1950) have again shown how prevailing differences in the structure of markets between developed and developing countries may turn the terms of trade against the latter; using a two-sector model, Bhagwati (1958) has demonstrated that such a deterioration in the terms of trade could bring about a net decrease in the welfare level of the countries concerned. Generally, the policy measures relevant to the "market imperfections" problem include the creation of job opportunities in the rural (rather than urban) sector, the encouragement of informal-sector enterprises,and the imposition of factor taxes and subsidies as a means of counteracting the adverse effect of factor price distortions on employment. A more recent approach to the unemployment problem is the plea by the International Labor Office (1970; 1972) for a redistribution of income within the developing countries. In terms of the two-sector model, such a policy may well succeed in eliminating labour unemployment caused by fixed factor proportions and/or factor price distortions. It should be realized, though, that a redistribution of income may lower the aggregate savings level, and hence also the growth rates of capital and labour employment in the economy. On the whole, it would seem that these theories do indeed adopt a modified version of the neoclassical theory in providing a fairly comprehensive explanation of the economic problems of labour unemployment, low incomes and inequality.
- Full Text:
- Date Issued: 1982
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