Desert
- Authors: Harper, Sean Julian
- Date: 2000
- Subjects: Rawls, John, 1921-2002 , Rawls, John, 1921-2002 Theory of justice , Ethics
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2710 , http://hdl.handle.net/10962/d1002840 , Rawls, John, 1921-2002 , Rawls, John, 1921-2002 Theory of justice , Ethics
- Description: This thesis examines the idea of desert as expounded in the work of John Rawls, and some of the implications of this conception of desert for moral and political philosophy. In this work, I analyse a series of arguments against retaining this particular conception of desert.I argue that none of these arguments sufficiently diminishes the force of Rawls’ argument for desert, while many of them do state, and I argue that they are correct in doing so, that this conception of desert is dangerous for political or moral philosophy to maintain. I argue that the moral, political and legal implications of accepting this account of desert severely undermine various institutions of differential treatment, and indeed, moral assessment. I regard it as obvious that societies must, on occasion, treat members of those societies differently, for moral, as well as practical reasons. The Rawlsian account of desert, and the account of responsibility on which it rests, however, will endanger the legitimacy of such procedures. I argue further that the Rawlsian account of desert requires that differences in wealth, and inheritance of wealth, influence and privilege be diminished, if not abolished, if we are to talk of any form of desert meaningfully. I argue that this is a strength of Rawls’ account, and further that any account of desert that is true to the philosophical tradition of the concept will require similar steps to be taken. The primary aim of this thesis is to show that Rawls’ arguments against desert are serious ones, both in terms of strength and scope, and that they must be addressed. I intend to show that these arguments are founded on strong moral intuitions, and that it is plausible that these intuitions may need revision. Finally,I intend to show that desert is an important moral and political concept, and that the disciplines of moral and political philosophy will be impoverished by the absence this concept. This absence, I will argue, is a natural consequence of the acceptance of the Rawlsian arguments.
- Full Text:
- Date Issued: 2000
- Authors: Harper, Sean Julian
- Date: 2000
- Subjects: Rawls, John, 1921-2002 , Rawls, John, 1921-2002 Theory of justice , Ethics
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2710 , http://hdl.handle.net/10962/d1002840 , Rawls, John, 1921-2002 , Rawls, John, 1921-2002 Theory of justice , Ethics
- Description: This thesis examines the idea of desert as expounded in the work of John Rawls, and some of the implications of this conception of desert for moral and political philosophy. In this work, I analyse a series of arguments against retaining this particular conception of desert.I argue that none of these arguments sufficiently diminishes the force of Rawls’ argument for desert, while many of them do state, and I argue that they are correct in doing so, that this conception of desert is dangerous for political or moral philosophy to maintain. I argue that the moral, political and legal implications of accepting this account of desert severely undermine various institutions of differential treatment, and indeed, moral assessment. I regard it as obvious that societies must, on occasion, treat members of those societies differently, for moral, as well as practical reasons. The Rawlsian account of desert, and the account of responsibility on which it rests, however, will endanger the legitimacy of such procedures. I argue further that the Rawlsian account of desert requires that differences in wealth, and inheritance of wealth, influence and privilege be diminished, if not abolished, if we are to talk of any form of desert meaningfully. I argue that this is a strength of Rawls’ account, and further that any account of desert that is true to the philosophical tradition of the concept will require similar steps to be taken. The primary aim of this thesis is to show that Rawls’ arguments against desert are serious ones, both in terms of strength and scope, and that they must be addressed. I intend to show that these arguments are founded on strong moral intuitions, and that it is plausible that these intuitions may need revision. Finally,I intend to show that desert is an important moral and political concept, and that the disciplines of moral and political philosophy will be impoverished by the absence this concept. This absence, I will argue, is a natural consequence of the acceptance of the Rawlsian arguments.
- Full Text:
- Date Issued: 2000
Replacement of seven 132/66 kv distance protection schemes by means of a generic relay implemented as a strategic spare
- Authors: Harris, Raymond Trevor
- Date: 2000
- Subjects: Protective relays , Electric power systems -- Protection
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10808 , http://hdl.handle.net/10948/34 , Protective relays , Electric power systems -- Protection
- Description: Eskom is experiencing problems in the field of protection maintenance and in-service breakdowns which negatively influence the quality of electrical supply to the consumer, an integral component of the utility business. These facts initiated the research into the further development of a generic relay to be implemented as a strategic spare for the replacement of several schemes operating within Eskom’s southern region. These include the electromechanical, solid state and numerical distance protection relay and scheme failures on the 132 / 66 kV feeder network. Hence, the primary objective of the research is to develop, test and configure the strategic spare in terms of software and peripheral hardware for the input and output terminal connections, generic equations and settings for the purpose of the scheme replacements. The various schemes are assessed for stepped distance and permissive intertripping for three or single pole operation. This is done in conjunction with the internal and external circuit diagrams in order to understand the detailed operation of the scheme and to ensure the effective implementation of the strategic spare. The generic relay is configured for the emergency replacement of the various schemes during in-service breakdowns. This constitutes a temporary installation and therefore the downtime in essence, of all the distance protection schemes that require replacement, is limited to a minimum. This dissertation therefore explores the implementation of the strategic spare.
- Full Text:
- Date Issued: 2000
- Authors: Harris, Raymond Trevor
- Date: 2000
- Subjects: Protective relays , Electric power systems -- Protection
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10808 , http://hdl.handle.net/10948/34 , Protective relays , Electric power systems -- Protection
- Description: Eskom is experiencing problems in the field of protection maintenance and in-service breakdowns which negatively influence the quality of electrical supply to the consumer, an integral component of the utility business. These facts initiated the research into the further development of a generic relay to be implemented as a strategic spare for the replacement of several schemes operating within Eskom’s southern region. These include the electromechanical, solid state and numerical distance protection relay and scheme failures on the 132 / 66 kV feeder network. Hence, the primary objective of the research is to develop, test and configure the strategic spare in terms of software and peripheral hardware for the input and output terminal connections, generic equations and settings for the purpose of the scheme replacements. The various schemes are assessed for stepped distance and permissive intertripping for three or single pole operation. This is done in conjunction with the internal and external circuit diagrams in order to understand the detailed operation of the scheme and to ensure the effective implementation of the strategic spare. The generic relay is configured for the emergency replacement of the various schemes during in-service breakdowns. This constitutes a temporary installation and therefore the downtime in essence, of all the distance protection schemes that require replacement, is limited to a minimum. This dissertation therefore explores the implementation of the strategic spare.
- Full Text:
- Date Issued: 2000
The implementation of a core architecture for geophysical data acquisition
- Authors: Heasman, Ray Edward
- Date: 2000
- Subjects: Geophysics -- Data processing , Computer software -- Development , Seismometers , Computer input-output equipment
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5471 , http://hdl.handle.net/10962/d1005256 , Geophysics -- Data processing , Computer software -- Development , Seismometers , Computer input-output equipment
- Description: This thesis describes the design, development and implementation of the core hardware and software of a modular data acquisition system for geophysical data collection. The primary application for this system is the acquisition and realtime processing of seismic data captured in mines. This system will be used by a commercial supplier of seismic instrumentation, ISS International, as a base architecture for the development of future products. The hardware and software has been designed to be extendable and support distributed processing. The IEEE-1394 High Performance Serial Bus is used to communicate with other CPU modules or peripherals. The software includes a pre-emptive multitasking microkernel, an asynchronous mailbox-based message passing communications system, and a functional IEEE-1394 protocol stack. The reasons for the end design and implementation decisions are given, and the problems encountered in the development of this system are described. A critical assessment of the match between the requirements for the project and the functionality of the implementation is made.
- Full Text:
- Date Issued: 2000
- Authors: Heasman, Ray Edward
- Date: 2000
- Subjects: Geophysics -- Data processing , Computer software -- Development , Seismometers , Computer input-output equipment
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5471 , http://hdl.handle.net/10962/d1005256 , Geophysics -- Data processing , Computer software -- Development , Seismometers , Computer input-output equipment
- Description: This thesis describes the design, development and implementation of the core hardware and software of a modular data acquisition system for geophysical data collection. The primary application for this system is the acquisition and realtime processing of seismic data captured in mines. This system will be used by a commercial supplier of seismic instrumentation, ISS International, as a base architecture for the development of future products. The hardware and software has been designed to be extendable and support distributed processing. The IEEE-1394 High Performance Serial Bus is used to communicate with other CPU modules or peripherals. The software includes a pre-emptive multitasking microkernel, an asynchronous mailbox-based message passing communications system, and a functional IEEE-1394 protocol stack. The reasons for the end design and implementation decisions are given, and the problems encountered in the development of this system are described. A critical assessment of the match between the requirements for the project and the functionality of the implementation is made.
- Full Text:
- Date Issued: 2000
A narrative study of teachers' life stories and their work identity
- Authors: Heaton, Pamela Jane
- Date: 2000
- Subjects: Identity (Psychology) -- Case studies , Teachers -- Case studies , Women teachers -- South Africa , Education -- South Africa -- History , Education -- South Africa -- Eastern Cape , Women teachers -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2989 , http://hdl.handle.net/10962/d1002498 , Identity (Psychology) -- Case studies , Teachers -- Case studies , Women teachers -- South Africa , Education -- South Africa -- History , Education -- South Africa -- Eastern Cape , Women teachers -- South Africa -- Eastern Cape
- Description: Media coverage of the poor state of this country's education system has described public images of the teaching profession which provide a context for the research described in this paper. The research is concerned with how and to what extent work identity is reflected in the life stories of five female teachers from a rural village in the Eastern Cape. A social constructionist approach is taken to the meaning and construction of identity, and the paper describes the process of a narrative method of analyzing and interpreting the stories. An initial analysis reveals that the participants had few career options and little choice of career. Further analysis is concerned with interpreting how the teachers create coherence in their stories around this lack of choice as well as within the larger social and historical context. Simultaneously there is an interpretation of the participants' work identity. The teachers create coherence in their narratives around their families and their socioeconomic or cultural circumstances, but make no explicit reference to the political context of their work choices, which were made in the context of the restraints of the Apartheid era. From each teacher's story an understanding of their unique work identity emerges. These alternative understandings provide a contrast to the images constructed by the media.
- Full Text:
- Date Issued: 2000
- Authors: Heaton, Pamela Jane
- Date: 2000
- Subjects: Identity (Psychology) -- Case studies , Teachers -- Case studies , Women teachers -- South Africa , Education -- South Africa -- History , Education -- South Africa -- Eastern Cape , Women teachers -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2989 , http://hdl.handle.net/10962/d1002498 , Identity (Psychology) -- Case studies , Teachers -- Case studies , Women teachers -- South Africa , Education -- South Africa -- History , Education -- South Africa -- Eastern Cape , Women teachers -- South Africa -- Eastern Cape
- Description: Media coverage of the poor state of this country's education system has described public images of the teaching profession which provide a context for the research described in this paper. The research is concerned with how and to what extent work identity is reflected in the life stories of five female teachers from a rural village in the Eastern Cape. A social constructionist approach is taken to the meaning and construction of identity, and the paper describes the process of a narrative method of analyzing and interpreting the stories. An initial analysis reveals that the participants had few career options and little choice of career. Further analysis is concerned with interpreting how the teachers create coherence in their stories around this lack of choice as well as within the larger social and historical context. Simultaneously there is an interpretation of the participants' work identity. The teachers create coherence in their narratives around their families and their socioeconomic or cultural circumstances, but make no explicit reference to the political context of their work choices, which were made in the context of the restraints of the Apartheid era. From each teacher's story an understanding of their unique work identity emerges. These alternative understandings provide a contrast to the images constructed by the media.
- Full Text:
- Date Issued: 2000
Assessing alternative assessment: students' experiences of the different forms of assessment in a Bachelor of Education course
- Authors: Hendricks, Monica
- Date: 2000
- Subjects: Education, Higher -- South Africa -- Evaluation Educational tests and measurements -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1424 , http://hdl.handle.net/10962/d1003305
- Description: In this study I examine the current alternative forms of assessment that were employed in the foundation year of the Bachelor of Education course at Rhodes University in 1998. Since assessment is concerned with ascertaining the amount, and kind, of learning that has taken place, it links learning and teaching. As my role in the course was academic development, I was interested in the nature ofthe development that the course promoted, for lecturers and students. My main intention was to gain insight into students' experiences of the assessment practices. To this end I selected six students, photocopied all their academic writing for the year and interviewed them. In addition, to provide a holistic picture of assessment and marking, I interviewed the six lecturers who team-taught the course. The data thus included the course assignments of the six students and an interview with each student as well as with the course lecturers. The findings show that though policy documents advocate alternative forms of assessment, implementing such assessment is a complex matter for both teachers and students.
- Full Text:
- Date Issued: 2000
- Authors: Hendricks, Monica
- Date: 2000
- Subjects: Education, Higher -- South Africa -- Evaluation Educational tests and measurements -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1424 , http://hdl.handle.net/10962/d1003305
- Description: In this study I examine the current alternative forms of assessment that were employed in the foundation year of the Bachelor of Education course at Rhodes University in 1998. Since assessment is concerned with ascertaining the amount, and kind, of learning that has taken place, it links learning and teaching. As my role in the course was academic development, I was interested in the nature ofthe development that the course promoted, for lecturers and students. My main intention was to gain insight into students' experiences of the assessment practices. To this end I selected six students, photocopied all their academic writing for the year and interviewed them. In addition, to provide a holistic picture of assessment and marking, I interviewed the six lecturers who team-taught the course. The data thus included the course assignments of the six students and an interview with each student as well as with the course lecturers. The findings show that though policy documents advocate alternative forms of assessment, implementing such assessment is a complex matter for both teachers and students.
- Full Text:
- Date Issued: 2000
Aspects of the ecology and reproductive biology of the limpet, Helcion pruinosus (Gastropoda : prosobranchia)
- Authors: Henninger, Tony Oskar
- Date: 2000
- Subjects: Prosobranchia , Limpets -- Reproduction , Limpets -- Ecology , Prosobranchia -- Ecology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5641 , http://hdl.handle.net/10962/d1005323 , Prosobranchia , Limpets -- Reproduction , Limpets -- Ecology , Prosobranchia -- Ecology
- Description: Helcion pruinosus, the rayed limpet, is found in the midshore region of the intertidal zone, (i.e. the Balanoid zone) of rocky shores, from Saldanha Bay to Sodwana Bay along the coast of South Africa. At Gonubie (32°57'S/25°01'E) this species of limpet was found under boulders, (when not feeding), and could reach average densities of 85/ m². The limpets prefer smooth boulders, avoiding those encrusted by coralline algae or boulders with a rough texture. There was no habitat segregation between adult and juvenile H. pruinosus, i.e. there was no sign of up-shore migration by larger individuals. Males out-numbered females by, on average 1.4 : 1, which was a similar sex ratio to that of the congeneric species, H. pectunculus (Gray, 996). Unlike H. pectunculus, there were no differences in shell lengths between males and females (p = 0.946 at Gonubie, south-east coast and p = 0.961 at Kommetjie, south-west coast; t-test). Shell height could also not be used as a criterion to differentiate between the sexes. The average maximum shell length of H. pruinosus at Gonubie and Kommetjie was 25 mm, but the maximum shell lengths found were 30 mm, (one individual in each case), on both the southeast coast and west coast. Growth occurred most rapidly in the first year of life, with individuals reaching 15 mm after 1 year. In the second year limpet growth slowed to only 7 mm. Sexual maturity was reached at a shell length of between 11 to 14 mm (at an age of 8 months to 1 year). The life-span of H. pruinosus was determined at 2.55 years on the south-east coast and 2.9 years on the south-west coast. Micro-growth bands were produced tidally. Growth occurred allometrically, i.e. shell length increased at a faster rate than shell height. The limpets foraged during low tide, at night, presumably feeding on epilithic algae on the boulders. A second smaller peak of limpet activity was often recorded during the day, when low tide coincided with dawn). More limpets (up to ten times more) were active at spring tides compared to neap tides. Limpet activity was greatest during the spring tides of autumn. During all seasons limpet activity peaked 30 minutes before low water, after which numbers decreased rapidly. All limpets had retreated beneath the boulders before being covered by the flooding tide. It was concluded that the limpets were responding to both endogenous and exogenous cues, but the actual stimulus for retreat could not be determined. The limpets did not return to a fixed scar nor did they return rigidly to a home site. H. pruinosus was found to be gonochoristic. Sexes could be separated, on dissection, according to the colour of their gonads (males had white gonads, whilst that of the females was olive-green). Gonads were present throughout the year in most individuals, i.e. totally spent animals were never observed. Reproductive seasonality was similar in west coast and south-east coast animals. The gonad indices of the west coast limpets were higher, (maximum of 35%), compared to that on the southeast coast, (25%). The animals were probably trickle spawners, with some individuals liberating gametes throughout the year. There was however synchrony in gametogenesis between male and female limpets on both the west coast and south-east coast lines. Gonad indices peaked in the summer months (October to December) with a second minor peak in April/May. These peaks occurred before the release of the gametes in spawning events. The gonad index was lowest in winter, (July). The ovaries were full of mature eggs (oocytes having a diameter of 200 to 250 ~) prior to spawning. The acinal wall thickness had been decreasing prior to spawning. After spawning there was an increase in previtellogenic eggs « 100 μm) in females, and an increase in the acinal wall thickness to indicate spermatogenesis. The two populations are subjected to different environmental conditions and the actual cue for stimulating the release of gametes could not be determined. Finally, a table of differences between H pruinosus and its sister species, H pectunculus was created to show the life-style of H pruinosus.
- Full Text:
- Date Issued: 2000
- Authors: Henninger, Tony Oskar
- Date: 2000
- Subjects: Prosobranchia , Limpets -- Reproduction , Limpets -- Ecology , Prosobranchia -- Ecology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5641 , http://hdl.handle.net/10962/d1005323 , Prosobranchia , Limpets -- Reproduction , Limpets -- Ecology , Prosobranchia -- Ecology
- Description: Helcion pruinosus, the rayed limpet, is found in the midshore region of the intertidal zone, (i.e. the Balanoid zone) of rocky shores, from Saldanha Bay to Sodwana Bay along the coast of South Africa. At Gonubie (32°57'S/25°01'E) this species of limpet was found under boulders, (when not feeding), and could reach average densities of 85/ m². The limpets prefer smooth boulders, avoiding those encrusted by coralline algae or boulders with a rough texture. There was no habitat segregation between adult and juvenile H. pruinosus, i.e. there was no sign of up-shore migration by larger individuals. Males out-numbered females by, on average 1.4 : 1, which was a similar sex ratio to that of the congeneric species, H. pectunculus (Gray, 996). Unlike H. pectunculus, there were no differences in shell lengths between males and females (p = 0.946 at Gonubie, south-east coast and p = 0.961 at Kommetjie, south-west coast; t-test). Shell height could also not be used as a criterion to differentiate between the sexes. The average maximum shell length of H. pruinosus at Gonubie and Kommetjie was 25 mm, but the maximum shell lengths found were 30 mm, (one individual in each case), on both the southeast coast and west coast. Growth occurred most rapidly in the first year of life, with individuals reaching 15 mm after 1 year. In the second year limpet growth slowed to only 7 mm. Sexual maturity was reached at a shell length of between 11 to 14 mm (at an age of 8 months to 1 year). The life-span of H. pruinosus was determined at 2.55 years on the south-east coast and 2.9 years on the south-west coast. Micro-growth bands were produced tidally. Growth occurred allometrically, i.e. shell length increased at a faster rate than shell height. The limpets foraged during low tide, at night, presumably feeding on epilithic algae on the boulders. A second smaller peak of limpet activity was often recorded during the day, when low tide coincided with dawn). More limpets (up to ten times more) were active at spring tides compared to neap tides. Limpet activity was greatest during the spring tides of autumn. During all seasons limpet activity peaked 30 minutes before low water, after which numbers decreased rapidly. All limpets had retreated beneath the boulders before being covered by the flooding tide. It was concluded that the limpets were responding to both endogenous and exogenous cues, but the actual stimulus for retreat could not be determined. The limpets did not return to a fixed scar nor did they return rigidly to a home site. H. pruinosus was found to be gonochoristic. Sexes could be separated, on dissection, according to the colour of their gonads (males had white gonads, whilst that of the females was olive-green). Gonads were present throughout the year in most individuals, i.e. totally spent animals were never observed. Reproductive seasonality was similar in west coast and south-east coast animals. The gonad indices of the west coast limpets were higher, (maximum of 35%), compared to that on the southeast coast, (25%). The animals were probably trickle spawners, with some individuals liberating gametes throughout the year. There was however synchrony in gametogenesis between male and female limpets on both the west coast and south-east coast lines. Gonad indices peaked in the summer months (October to December) with a second minor peak in April/May. These peaks occurred before the release of the gametes in spawning events. The gonad index was lowest in winter, (July). The ovaries were full of mature eggs (oocytes having a diameter of 200 to 250 ~) prior to spawning. The acinal wall thickness had been decreasing prior to spawning. After spawning there was an increase in previtellogenic eggs « 100 μm) in females, and an increase in the acinal wall thickness to indicate spermatogenesis. The two populations are subjected to different environmental conditions and the actual cue for stimulating the release of gametes could not be determined. Finally, a table of differences between H pruinosus and its sister species, H pectunculus was created to show the life-style of H pruinosus.
- Full Text:
- Date Issued: 2000
Professional development in environmental education in Zanzibar, Tanzania: distances encountered in a semi-distance learning course
- Authors: Heylings, Phillippa Frances
- Date: 2000
- Subjects: Environmental education -- Tanzania -- Zanzibar Distance education -- Tanzania -- Zanzibar Environmental education Distance education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1715 , http://hdl.handle.net/10962/d1003598
- Description: In Zanzibar, in 1995, opportunities for professional development in environmental education were minimal. Yet the demand for professional development was high, especially because of an emphasis on formal qualifications in the country. Credibility was afforded to forms of professional development, aimed at creating more ‘experts’. Ongoing environmental education practice was not achieving its objectives. Into this setting, which was culturally and socio-politically different from the South African context where it was developed, I introduced the Rhodes University Certificate and Gold Fields Participatory Course in Environmental Education (RU/GF); a non-formal, counter-hegemonic course which encouraged critical reflection on the dominant orientations to environmental education practice – including professional development. I used critical ethnographic and action research methods to explore my praxiological interest, the adaptation of the RU/GF curriculum to the Zanzibar context. During the research process, a decision was made to formally accredit the RU/GF course. This decision did not alter the course orientation or the learning process but opened up possibilities for future curriculum development processes. It allowed the students both a formal qualification necessary for status and promotion, and participation in a learning process that challenged the dominant paradigm on professional development and status from within the socio-political context. The research took on a reflexive orientation to research and environmental education. Through a dialectical development of theory, method and results, several important issues emerged. These deal with the ‘distances’ encountered in attempting to address some of the perceived dichotomies in professional development in environmental education through semi-distance learning: the distances between status and learning; the need for career upgrading and the type of learning considered appropriate for professional development in environmental education; the non-quantifiable aims associated with a reflexive orientation to professional development and formal assessment demands for measurable criteria; the democratisation of open-entry courses and the elitism of restricted access; the focus on individual growth and the attainment of a normative grade; theory and practice; and finally distances between learner, text and language. The research supports similar findings emerging from evaluation of the RU/GF course in South Africa and resonates with, and contributes to, issues concerning professional development in environmental education being considered internationally.
- Full Text:
- Date Issued: 2000
- Authors: Heylings, Phillippa Frances
- Date: 2000
- Subjects: Environmental education -- Tanzania -- Zanzibar Distance education -- Tanzania -- Zanzibar Environmental education Distance education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1715 , http://hdl.handle.net/10962/d1003598
- Description: In Zanzibar, in 1995, opportunities for professional development in environmental education were minimal. Yet the demand for professional development was high, especially because of an emphasis on formal qualifications in the country. Credibility was afforded to forms of professional development, aimed at creating more ‘experts’. Ongoing environmental education practice was not achieving its objectives. Into this setting, which was culturally and socio-politically different from the South African context where it was developed, I introduced the Rhodes University Certificate and Gold Fields Participatory Course in Environmental Education (RU/GF); a non-formal, counter-hegemonic course which encouraged critical reflection on the dominant orientations to environmental education practice – including professional development. I used critical ethnographic and action research methods to explore my praxiological interest, the adaptation of the RU/GF curriculum to the Zanzibar context. During the research process, a decision was made to formally accredit the RU/GF course. This decision did not alter the course orientation or the learning process but opened up possibilities for future curriculum development processes. It allowed the students both a formal qualification necessary for status and promotion, and participation in a learning process that challenged the dominant paradigm on professional development and status from within the socio-political context. The research took on a reflexive orientation to research and environmental education. Through a dialectical development of theory, method and results, several important issues emerged. These deal with the ‘distances’ encountered in attempting to address some of the perceived dichotomies in professional development in environmental education through semi-distance learning: the distances between status and learning; the need for career upgrading and the type of learning considered appropriate for professional development in environmental education; the non-quantifiable aims associated with a reflexive orientation to professional development and formal assessment demands for measurable criteria; the democratisation of open-entry courses and the elitism of restricted access; the focus on individual growth and the attainment of a normative grade; theory and practice; and finally distances between learner, text and language. The research supports similar findings emerging from evaluation of the RU/GF course in South Africa and resonates with, and contributes to, issues concerning professional development in environmental education being considered internationally.
- Full Text:
- Date Issued: 2000
Integrating customer requirements in the design of service processes in South African motor dealership
- Authors: Hodgkinson, Peter
- Date: 2000
- Subjects: Automobile industry and trade -- Customer services , Automobile industry and trade -- South Africa , Customer services -- Quality control
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10837 , http://hdl.handle.net/10948/30 , Automobile industry and trade -- Customer services , Automobile industry and trade -- South Africa , Customer services -- Quality control
- Description: The Motor Industry is set in a highly competitive and dynamic global arena constantly shaped by both external and internal forces. From an organisations point of view many of the external or macro forces are largely uncontrollable. Against this backdrop, players in the South African Motor Industry need to find new methods of differentiating themselves from competitors – One manner of performing this strategy is for Motor Dealerships to understand, meet or exceed customer requirements. In this research, the literature survey revealed the concepts of Total Quality Management (TQM) and fail-safing, the meaning of superior customer service and the importance of customer loyalty and retention. Customer service excellence levels of three Williams Hunt dealerships in the Port Elizabeth – Uitenhage metropole were measured by utilizing the SERVQUAL instrument for calibrating service quality. Customer expectations and perceptions were determined by means of the empirical study which yielded a service quality “gap.” From analysis of this gap and related findings, suggested improvements were suggested as a guideline for dealerships to utilise with the aim of improving customer service levels.
- Full Text:
- Date Issued: 2000
- Authors: Hodgkinson, Peter
- Date: 2000
- Subjects: Automobile industry and trade -- Customer services , Automobile industry and trade -- South Africa , Customer services -- Quality control
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10837 , http://hdl.handle.net/10948/30 , Automobile industry and trade -- Customer services , Automobile industry and trade -- South Africa , Customer services -- Quality control
- Description: The Motor Industry is set in a highly competitive and dynamic global arena constantly shaped by both external and internal forces. From an organisations point of view many of the external or macro forces are largely uncontrollable. Against this backdrop, players in the South African Motor Industry need to find new methods of differentiating themselves from competitors – One manner of performing this strategy is for Motor Dealerships to understand, meet or exceed customer requirements. In this research, the literature survey revealed the concepts of Total Quality Management (TQM) and fail-safing, the meaning of superior customer service and the importance of customer loyalty and retention. Customer service excellence levels of three Williams Hunt dealerships in the Port Elizabeth – Uitenhage metropole were measured by utilizing the SERVQUAL instrument for calibrating service quality. Customer expectations and perceptions were determined by means of the empirical study which yielded a service quality “gap.” From analysis of this gap and related findings, suggested improvements were suggested as a guideline for dealerships to utilise with the aim of improving customer service levels.
- Full Text:
- Date Issued: 2000
Mesozooplankton community structure in the vicinity of the Prince Edward Islands (Southern Ocean) 37⁰ 50'E, 46⁰ 45'S
- Authors: Hunt, Brian Peter Vere
- Date: 2000
- Subjects: Zooplankton , Zooplankton -- Prince Edward Islands , Phytoplankton , Chlorophyll
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5732 , http://hdl.handle.net/10962/d1005418 , Zooplankton , Zooplankton -- Prince Edward Islands , Phytoplankton , Chlorophyll
- Description: Mesozooplankton community structure in the vicinity of the Prince Edward Islands (PEIs) was investigated during six surveys conducted in late austral summer (April/May), 1996 to 1999. Each year zooplankton samples were collected with a bongo net (300 µm mesh) at stations upstream (west), between and downstream (east) of the islands. Chlorophyll a concentrations were determined fluorometrically, corresponding with each net tow. The positions of the Subantarctic Front (SAF) and the Antarctic Polar Front (APF), in relation to the islands in the upstream region, were determined by a line of CTD and/or XBT stations. Both the SAF and the APF were characterised by a high degree of meridional variation in position. Changes in position of the fronts were shown to occur very rapidly. In 1999 the APF moved southwards by ~40nm and the SAF northwards by ~60nm in a period of two weeks, while in 1996 the SAF appeared to move ~120nm northwards in a two week period. The positions of the SAF and APF appeared to have a significant impact on phytoplankton biomass in the vicinity of the PEIs, through the alteration of local flow dynamics. Water retention in 1996, associated with the location of the SAF and APF far to the north and south of the PEIs respectively, corresponded with high chlorophyll a concentrations in the inter-island region (reaching 1.54 mg.m^(-3)). When the fronts were close to the islands, in 1997 and 1999, and a flow through environment existed, chlorophyll a concentrations in the inter-island region were comparatively low. Although biomass enhancement was only observed at the SAF in 1996, phytoplankton size structure in 1999 indicated that, when close to the PEIs, frontal production may be transported to the island system. This is potentially an important source of allochthonous input into the island system. Zooplankton assemblages were a mix of sub-Antarctic and Antarctic communities, with a weak presence of sub-tropical species. Cluster analysis showed that during each survey the region in the vicinity of the PEIs was divided into different, spatially separated zooplankton communities, associated with water masses of different origins. These communities were identified by variations in the abundance and biomass of species rather than variation in species composition and, in general, there was a relatively high degree of similarity both within and between surveys. Inter-annual community analysis revealed that, in many cases, there was greater similarity between communities from different years than communities within years, indicating that short-term variability exceeded inter-annual variability. Multiple regression analysis showed that the major correlate with zooplankton community structure during all surveys was sea temperature, accounting for as much as 77% of the variation in community structure. Temperature was indicative of the relative contribution of sub-Antarctic and Antarctic communities, with low temperatures being characterised by an increased predominance of Antarctic communities and vice versa. The differentiation between sub-Antarctic and Antarctic waters, and their respective communities, was particularly pronounced when the SAF and APF were in close proximity to the islands. Surface salinity and sounding had limited effect on community structure. The affect of sounding was intrinsically related to zooplankton interaction with the island ecosystem. Predation by the islands' land based predators and benthic fish appears to decrease zooplankton biomass over the island shelf, particularly the macrozooplankton size fraction. However, this may only be an important factor under conditions of water retention when replenishment of zooplankton stocks is low. The low densities of many macrozooplankton species, and other deep migrators, on the island shelf may be due to their limited advection onto shallow topography. By contrast, there are indications that zooplankton species occurring at shallower depths may be concentrated in the inter-island region by mesoscale flow patterns. Analysis of the population structure of the copepod Calanus simillimus showed that this species occurred at different stages in its life cycle during different years, even though sampling took place in the same calendar months, indicating that there was inter-annual variation in the timing of the biological season. Differences in the population structure of species, and consequently their contribution to abundance and biomass, may therefore have been an important contributor to inter-annual variation in community structure. Evidence is provided for a long-term trend of southward movement of the SAF. This may have a significant affect on the PEI ecosystem, increasing the proportion of allochthonous input and altering the tropho-dynamics of the island ecosystem
- Full Text:
- Date Issued: 2000
- Authors: Hunt, Brian Peter Vere
- Date: 2000
- Subjects: Zooplankton , Zooplankton -- Prince Edward Islands , Phytoplankton , Chlorophyll
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5732 , http://hdl.handle.net/10962/d1005418 , Zooplankton , Zooplankton -- Prince Edward Islands , Phytoplankton , Chlorophyll
- Description: Mesozooplankton community structure in the vicinity of the Prince Edward Islands (PEIs) was investigated during six surveys conducted in late austral summer (April/May), 1996 to 1999. Each year zooplankton samples were collected with a bongo net (300 µm mesh) at stations upstream (west), between and downstream (east) of the islands. Chlorophyll a concentrations were determined fluorometrically, corresponding with each net tow. The positions of the Subantarctic Front (SAF) and the Antarctic Polar Front (APF), in relation to the islands in the upstream region, were determined by a line of CTD and/or XBT stations. Both the SAF and the APF were characterised by a high degree of meridional variation in position. Changes in position of the fronts were shown to occur very rapidly. In 1999 the APF moved southwards by ~40nm and the SAF northwards by ~60nm in a period of two weeks, while in 1996 the SAF appeared to move ~120nm northwards in a two week period. The positions of the SAF and APF appeared to have a significant impact on phytoplankton biomass in the vicinity of the PEIs, through the alteration of local flow dynamics. Water retention in 1996, associated with the location of the SAF and APF far to the north and south of the PEIs respectively, corresponded with high chlorophyll a concentrations in the inter-island region (reaching 1.54 mg.m^(-3)). When the fronts were close to the islands, in 1997 and 1999, and a flow through environment existed, chlorophyll a concentrations in the inter-island region were comparatively low. Although biomass enhancement was only observed at the SAF in 1996, phytoplankton size structure in 1999 indicated that, when close to the PEIs, frontal production may be transported to the island system. This is potentially an important source of allochthonous input into the island system. Zooplankton assemblages were a mix of sub-Antarctic and Antarctic communities, with a weak presence of sub-tropical species. Cluster analysis showed that during each survey the region in the vicinity of the PEIs was divided into different, spatially separated zooplankton communities, associated with water masses of different origins. These communities were identified by variations in the abundance and biomass of species rather than variation in species composition and, in general, there was a relatively high degree of similarity both within and between surveys. Inter-annual community analysis revealed that, in many cases, there was greater similarity between communities from different years than communities within years, indicating that short-term variability exceeded inter-annual variability. Multiple regression analysis showed that the major correlate with zooplankton community structure during all surveys was sea temperature, accounting for as much as 77% of the variation in community structure. Temperature was indicative of the relative contribution of sub-Antarctic and Antarctic communities, with low temperatures being characterised by an increased predominance of Antarctic communities and vice versa. The differentiation between sub-Antarctic and Antarctic waters, and their respective communities, was particularly pronounced when the SAF and APF were in close proximity to the islands. Surface salinity and sounding had limited effect on community structure. The affect of sounding was intrinsically related to zooplankton interaction with the island ecosystem. Predation by the islands' land based predators and benthic fish appears to decrease zooplankton biomass over the island shelf, particularly the macrozooplankton size fraction. However, this may only be an important factor under conditions of water retention when replenishment of zooplankton stocks is low. The low densities of many macrozooplankton species, and other deep migrators, on the island shelf may be due to their limited advection onto shallow topography. By contrast, there are indications that zooplankton species occurring at shallower depths may be concentrated in the inter-island region by mesoscale flow patterns. Analysis of the population structure of the copepod Calanus simillimus showed that this species occurred at different stages in its life cycle during different years, even though sampling took place in the same calendar months, indicating that there was inter-annual variation in the timing of the biological season. Differences in the population structure of species, and consequently their contribution to abundance and biomass, may therefore have been an important contributor to inter-annual variation in community structure. Evidence is provided for a long-term trend of southward movement of the SAF. This may have a significant affect on the PEI ecosystem, increasing the proportion of allochthonous input and altering the tropho-dynamics of the island ecosystem
- Full Text:
- Date Issued: 2000
Development of a model of factors promoting team effectiveness in the automotive component industry
- Authors: Hutton, Timothy Strathearn
- Date: 2000
- Subjects: Teams in the workplace , Automobile industry and trade -- Management , Automobile industry and trade -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10833 , http://hdl.handle.net/10948/24 , Teams in the workplace , Automobile industry and trade -- Management , Automobile industry and trade -- South Africa
- Description: The research problem addressed in this study was to determine what makes a work team successful. To achieve this objective a theoretical model of factors promoting team effectiveness was developed, using relevant literature in which models for team effectiveness are described. The theoretical model consisted of the following factors: Individual background factors; Facilitation; Team Factors; Synergy; Team effectiveness; Organisational factors. Each factor of the model was broken down into dimensions that were then analysed using literature identified during the literature study. The theoretical model was then used to develop a questionnaire to test the degree to which managers working for automotive component manufacturers in the Port Elizabeth /Uitenhage magisterial district and falling under Chapter III of the Bargaining Council for the Motor Industry concur. The empirical results obtained indicate a strong concurrence with the theoretical model of factors promoting team effectiveness that was developed in the study. This resulted in the theoretical model being confirmed and being accepted as a model of factors promoting team effectiveness.
- Full Text:
- Date Issued: 2000
- Authors: Hutton, Timothy Strathearn
- Date: 2000
- Subjects: Teams in the workplace , Automobile industry and trade -- Management , Automobile industry and trade -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10833 , http://hdl.handle.net/10948/24 , Teams in the workplace , Automobile industry and trade -- Management , Automobile industry and trade -- South Africa
- Description: The research problem addressed in this study was to determine what makes a work team successful. To achieve this objective a theoretical model of factors promoting team effectiveness was developed, using relevant literature in which models for team effectiveness are described. The theoretical model consisted of the following factors: Individual background factors; Facilitation; Team Factors; Synergy; Team effectiveness; Organisational factors. Each factor of the model was broken down into dimensions that were then analysed using literature identified during the literature study. The theoretical model was then used to develop a questionnaire to test the degree to which managers working for automotive component manufacturers in the Port Elizabeth /Uitenhage magisterial district and falling under Chapter III of the Bargaining Council for the Motor Industry concur. The empirical results obtained indicate a strong concurrence with the theoretical model of factors promoting team effectiveness that was developed in the study. This resulted in the theoretical model being confirmed and being accepted as a model of factors promoting team effectiveness.
- Full Text:
- Date Issued: 2000
A critical investigation of a planned organisation change initiative within an educational institution in the Eastern Cape Province
- Authors: Irvine, Margaret Hillian
- Date: 2000
- Subjects: School management and organization -- South Africa -- Evaluation Education and state Educational change -- South Africa -- Eastern Cape Education -- Economic aspects Organizational change -- South Africa -- Management Non-governmental organizations -- South Africa -- Eastern Cape School management and organization -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1479 , http://hdl.handle.net/10962/d1003360
- Description: South Africa is living is turbulent times at present. Non-government educational organisations are challenged by changes in education policy and by scarcity of donor funding for their work. This study focuses on the management of organisation change in a non-government organisation (NGO) working in rural areas of the Eastern Cape Province. I undertook the research to gain a clearer understanding of the management of organisational change. I used a third-wave change management approach, the future search conference, to conduct the process of change with the NGO. It focuses on the positive aspects of the organisation, its potential and its desired future. I conducted both the study and the future search conference as participatory action research, which involved the participants in the cycles of planning, action, observation and reflection and thus built ownership of the solutions they generated. I used the accounts of the activities arising from the future search conference, minutes of meetings, semistructured interviews and observation of behaviour to gather data. I analysed the data using triangulation, and in particular, space triangulation, to minimise the impact of the differences in culture and language use in the facilitator and participants. Analysis of the data collected revealed in the NGO that change and transformation are slow processes requiring ongoing support from the OD consultant. The staff defined organisational effectiveness, the goal of organisational change initiatives, in terms of fundraising ability. This ability embraces many of the qualities of a learning organisation and open systems thinking, two requirements for successful organisational change. In the NGO both organisation development and transformation were processes as well as products, and changes could not easily be measured until after the processes were completed. Organisational culture, and in particular the juxtaposition of the values of the organisation and staff and those of its partners and clients, played an important role in transformation. The differences lay in a ‘being’ and a ‘task’ orientation and the staff’s responsibility lay in building connections between the two. The staff received the approach of the future search conference well and there was an equally good fit between the future search conference and participatory action research. This needs to be investigated further with regard to change management in South African organisations.
- Full Text:
- Date Issued: 2000
- Authors: Irvine, Margaret Hillian
- Date: 2000
- Subjects: School management and organization -- South Africa -- Evaluation Education and state Educational change -- South Africa -- Eastern Cape Education -- Economic aspects Organizational change -- South Africa -- Management Non-governmental organizations -- South Africa -- Eastern Cape School management and organization -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1479 , http://hdl.handle.net/10962/d1003360
- Description: South Africa is living is turbulent times at present. Non-government educational organisations are challenged by changes in education policy and by scarcity of donor funding for their work. This study focuses on the management of organisation change in a non-government organisation (NGO) working in rural areas of the Eastern Cape Province. I undertook the research to gain a clearer understanding of the management of organisational change. I used a third-wave change management approach, the future search conference, to conduct the process of change with the NGO. It focuses on the positive aspects of the organisation, its potential and its desired future. I conducted both the study and the future search conference as participatory action research, which involved the participants in the cycles of planning, action, observation and reflection and thus built ownership of the solutions they generated. I used the accounts of the activities arising from the future search conference, minutes of meetings, semistructured interviews and observation of behaviour to gather data. I analysed the data using triangulation, and in particular, space triangulation, to minimise the impact of the differences in culture and language use in the facilitator and participants. Analysis of the data collected revealed in the NGO that change and transformation are slow processes requiring ongoing support from the OD consultant. The staff defined organisational effectiveness, the goal of organisational change initiatives, in terms of fundraising ability. This ability embraces many of the qualities of a learning organisation and open systems thinking, two requirements for successful organisational change. In the NGO both organisation development and transformation were processes as well as products, and changes could not easily be measured until after the processes were completed. Organisational culture, and in particular the juxtaposition of the values of the organisation and staff and those of its partners and clients, played an important role in transformation. The differences lay in a ‘being’ and a ‘task’ orientation and the staff’s responsibility lay in building connections between the two. The staff received the approach of the future search conference well and there was an equally good fit between the future search conference and participatory action research. This needs to be investigated further with regard to change management in South African organisations.
- Full Text:
- Date Issued: 2000
Aspects of reproduction in the four-striped field mouse, Rhabdomys pumilio
- Authors: Jackson, Claire
- Date: 2000
- Subjects: Microtus , Mice , Mice -- Reproduction
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5637 , http://hdl.handle.net/10962/d1005319 , Microtus , Mice , Mice -- Reproduction
- Description: Rhabdomys pumilio, in the Eastern Cape of South Africa, does not use short day length as an inhibitory cue for reproductive activity, and, despite previous records indicating that these mice are strictly seasonal in their reproduction, litters have been found during the winters of some years,both in the Eastern Cape and in the Western Cape. This led me to believe that the reproductive activity of Rhabdomys pumilio is more opportunistic and that the cue or cues used to control reproduction are less predictable and, or more variable than the photoperiod cue used by many seasonally reproducing rodents. Two experiments were conducted, investigating the influence of low ambient temperature (15⁰C)and reduced food availability on the reproductive activity of both male and female four striped field mice. Mice were maintained in one of four conditions (food restricted at 15⁰C, food restricted at 26⁰C, ad lib. food at 15⁰C, and ad lib. food at 26⁰C) for 4 (males) and 8 weeks (females)(photoperiod 12L:12D, humidity 40%). Results indicated that the males reduced their reproductive activity slightly when exposed to either low temperature or low food availability and that maximum inhibition of reproduction occurred when mice were exposed to both low temperature and low food availability. However, female reproductive activity was inhibited when exposed to low food availability, irrespective of the temperature. Both sexes of mice showed varying abilities to resist fat loss and, in the males, the size of the fat store had a significant effect on reproduction. This varying ability to resist fat loss could be related to levels of activity and in the females (where activity was quantified), high activity scores were significantly associated with reproductive inhibition. These results support the hypothesis that reproduction in Rhabdomys pumilio is opportunistic and controlled by the availability of energy. I propose that the females will be more sensitive to reproductive inhibition due to their far greater post-fertilization responsibilities, where the reproductive activity of the females is rapidly inhibited by a reduction in food availability, while the males are less readily inhibited by low food availability or low temperature, unless the change in the controlling factors is severe enough, or prolonged, at which stage their reproductive activity will cease. The significance of opportunistic reproduction in the seasonal but unpredictable climate of the study area is discussed.
- Full Text:
- Date Issued: 2000
- Authors: Jackson, Claire
- Date: 2000
- Subjects: Microtus , Mice , Mice -- Reproduction
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5637 , http://hdl.handle.net/10962/d1005319 , Microtus , Mice , Mice -- Reproduction
- Description: Rhabdomys pumilio, in the Eastern Cape of South Africa, does not use short day length as an inhibitory cue for reproductive activity, and, despite previous records indicating that these mice are strictly seasonal in their reproduction, litters have been found during the winters of some years,both in the Eastern Cape and in the Western Cape. This led me to believe that the reproductive activity of Rhabdomys pumilio is more opportunistic and that the cue or cues used to control reproduction are less predictable and, or more variable than the photoperiod cue used by many seasonally reproducing rodents. Two experiments were conducted, investigating the influence of low ambient temperature (15⁰C)and reduced food availability on the reproductive activity of both male and female four striped field mice. Mice were maintained in one of four conditions (food restricted at 15⁰C, food restricted at 26⁰C, ad lib. food at 15⁰C, and ad lib. food at 26⁰C) for 4 (males) and 8 weeks (females)(photoperiod 12L:12D, humidity 40%). Results indicated that the males reduced their reproductive activity slightly when exposed to either low temperature or low food availability and that maximum inhibition of reproduction occurred when mice were exposed to both low temperature and low food availability. However, female reproductive activity was inhibited when exposed to low food availability, irrespective of the temperature. Both sexes of mice showed varying abilities to resist fat loss and, in the males, the size of the fat store had a significant effect on reproduction. This varying ability to resist fat loss could be related to levels of activity and in the females (where activity was quantified), high activity scores were significantly associated with reproductive inhibition. These results support the hypothesis that reproduction in Rhabdomys pumilio is opportunistic and controlled by the availability of energy. I propose that the females will be more sensitive to reproductive inhibition due to their far greater post-fertilization responsibilities, where the reproductive activity of the females is rapidly inhibited by a reduction in food availability, while the males are less readily inhibited by low food availability or low temperature, unless the change in the controlling factors is severe enough, or prolonged, at which stage their reproductive activity will cease. The significance of opportunistic reproduction in the seasonal but unpredictable climate of the study area is discussed.
- Full Text:
- Date Issued: 2000
Possible crosstalk between signal transduction pathways in the induction of differentiation in HT-29 cells
- Authors: Jamie, Hajierah
- Date: 2000
- Subjects: Cellular signal transduction , Cell differentiation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11096 , http://hdl.handle.net/10948/d1019684
- Description: The investigation into the mechanisms by which compounds such as butyrate induce differentiation in HT-29 cells, is lacking. The colonic carcinoma cell line, HT-29, undergoes differentiation induction in the presence of butyrate and acetoacetate. The Caco-2 cell line spontaneously differentiates on contact inhibition. In this study, a signal transduction pathway involving ATP, cAMP, Ca2+ and the transcriptional factor CREB was investigated following suggestions that the energy state of the cell and diffferentiation are linked. The activity of the MAP kinase cascade, including possible crosstalk that may exist between these pathways was determined. The HT-29 cells were exposed to 5 mM acetoacetate, butyrate, DMSO and propionate. The results of this differentiation induction were compared to Caco-2 and HeLa cells, which are cervical carcinoma cells. It was found that ATP levels are decreased on differentiation induction in HT-29 cells, which, in turn affected the cAMP concentrations. Theoretically, the inducers do not have any effect on PDE 4 activity, and may facilitate the interaction between cAMP and PKA. Influx of Ca2+ into the cells was inhibited to a degree by the inducers, which was possibly overcome by crosstalk between the cAMP and Ca2+ pathways. CREB activation, lineage-specific gene expression, ERK activity and c-myc expression were all dependent on both the inducers used and the cell-type. PKA played a major role in CREB activation in acetoacetate- and butyrate -induced HT-29, Caco-2 and HeLa cells, while a2+/Calmodulin-dependent kinases I/IV may have a secondary role. Alkaline phosphatase expression in HeLa cells was independent of CREB. Evidence that crosstalk between the MAP kinase cascade and the REBactivation pathways exist, was illustrated by increased CREB activation on ERK inhibition in acetoacetate- and butyrate-induced HT-29 and HeLa cells. Also, the role that ERK played in the cells differed with inducer and cell-type. The dependence of cmyc expression on c-jun and c-fos, appeared to be differentiation induction- and celltype specific. Results from this study indicate the potential use of acetoacetate and butyrate as anti-cancer compounds.
- Full Text:
- Date Issued: 2000
- Authors: Jamie, Hajierah
- Date: 2000
- Subjects: Cellular signal transduction , Cell differentiation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11096 , http://hdl.handle.net/10948/d1019684
- Description: The investigation into the mechanisms by which compounds such as butyrate induce differentiation in HT-29 cells, is lacking. The colonic carcinoma cell line, HT-29, undergoes differentiation induction in the presence of butyrate and acetoacetate. The Caco-2 cell line spontaneously differentiates on contact inhibition. In this study, a signal transduction pathway involving ATP, cAMP, Ca2+ and the transcriptional factor CREB was investigated following suggestions that the energy state of the cell and diffferentiation are linked. The activity of the MAP kinase cascade, including possible crosstalk that may exist between these pathways was determined. The HT-29 cells were exposed to 5 mM acetoacetate, butyrate, DMSO and propionate. The results of this differentiation induction were compared to Caco-2 and HeLa cells, which are cervical carcinoma cells. It was found that ATP levels are decreased on differentiation induction in HT-29 cells, which, in turn affected the cAMP concentrations. Theoretically, the inducers do not have any effect on PDE 4 activity, and may facilitate the interaction between cAMP and PKA. Influx of Ca2+ into the cells was inhibited to a degree by the inducers, which was possibly overcome by crosstalk between the cAMP and Ca2+ pathways. CREB activation, lineage-specific gene expression, ERK activity and c-myc expression were all dependent on both the inducers used and the cell-type. PKA played a major role in CREB activation in acetoacetate- and butyrate -induced HT-29, Caco-2 and HeLa cells, while a2+/Calmodulin-dependent kinases I/IV may have a secondary role. Alkaline phosphatase expression in HeLa cells was independent of CREB. Evidence that crosstalk between the MAP kinase cascade and the REBactivation pathways exist, was illustrated by increased CREB activation on ERK inhibition in acetoacetate- and butyrate-induced HT-29 and HeLa cells. Also, the role that ERK played in the cells differed with inducer and cell-type. The dependence of cmyc expression on c-jun and c-fos, appeared to be differentiation induction- and celltype specific. Results from this study indicate the potential use of acetoacetate and butyrate as anti-cancer compounds.
- Full Text:
- Date Issued: 2000
Exploring the needs and experiences of the social worker as an intermediary
- Authors: Jarman, Renette
- Date: 2000
- Subjects: Social workers , Mediation
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:698 , http://hdl.handle.net/10962/d1006419 , Social workers , Mediation
- Description: During this research an attempt was made to gain an understanding of the experiences and needs of the social workers acting as intermediaries for the sexually abused children in the criminal court during the trials of perpetrators. To achieve this, ten social workers that have performed the role of intermediary were interviewed. Research as well as literature on this topic is limited and it is believed that this study will present a valuable basis to pursue in further research as well as assist social workers already rendering intermediary services. Literature that was available was found to be critical of the adversarial system and the negative elements associated with the system, especially for the child witness. The study found that there are many problems associated with the intermediary system. The most important issue is the delay between the decision to prosecute and the trial as this impacts negatively on the child witness. In addition social workers acting as intermediaries are inadequately trained and are not supervised in this role. As a result very few are willing to continue with the procedure. Nevertheless the intermediary system is adjudged better than the adversarial system, especially as the child witness no longer has to face the alleged perpetrator in an open court. The thesis ends with recommendations for addressing the concerns of intermediaries in order to strengthen the system.
- Full Text:
- Date Issued: 2000
- Authors: Jarman, Renette
- Date: 2000
- Subjects: Social workers , Mediation
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:698 , http://hdl.handle.net/10962/d1006419 , Social workers , Mediation
- Description: During this research an attempt was made to gain an understanding of the experiences and needs of the social workers acting as intermediaries for the sexually abused children in the criminal court during the trials of perpetrators. To achieve this, ten social workers that have performed the role of intermediary were interviewed. Research as well as literature on this topic is limited and it is believed that this study will present a valuable basis to pursue in further research as well as assist social workers already rendering intermediary services. Literature that was available was found to be critical of the adversarial system and the negative elements associated with the system, especially for the child witness. The study found that there are many problems associated with the intermediary system. The most important issue is the delay between the decision to prosecute and the trial as this impacts negatively on the child witness. In addition social workers acting as intermediaries are inadequately trained and are not supervised in this role. As a result very few are willing to continue with the procedure. Nevertheless the intermediary system is adjudged better than the adversarial system, especially as the child witness no longer has to face the alleged perpetrator in an open court. The thesis ends with recommendations for addressing the concerns of intermediaries in order to strengthen the system.
- Full Text:
- Date Issued: 2000
Exploring the making of meaning: environmental education and training for industry, business and local government
- Authors: Jenkin, Nicola Pat
- Date: 2000
- Subjects: Environmental education Corporations -- environmental aspects Local government -- environmental aspects Managerial economics -- environmental aspects
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1543 , http://hdl.handle.net/10962/d1003425
- Description: The aim of this research was to explore how participants made meaning in an environmental education and training course for people from industry, business and local government in South Africa, and to identify and comment on any constraints to this meaning-making. I used a Symbolic Interactionist theoretical framework to explore and comment on the meaning-making process. I started my research by conducting a questionnaire to select participants for interviews. During the course the selected participants were interviewed, as well as the two course co-ordinators. Data was also gathered during the course from participant observation field notes ('captured talk'), photographs, participants' assignments and course evaluations. The data was analysed using an adapted form of discourse analysis and matrices. The research highlights that the opportunities provided on the course were adequate for encouraging meaning-making amongst both the co-ordinators and participants. However, recorded instances of meaning-making were low, which indicated that there were certain constraints during the meaning-making process. This research highlights and comments on identified constraints such as time and workplace support. The research supports similar findings which emerged from research conducted on the Gold Fields environmental education course for teachers and also offers recommendations for further research and practice into meaning-;making within the field of environmental education and industry, business and local government in South Africa.
- Full Text:
- Date Issued: 2000
- Authors: Jenkin, Nicola Pat
- Date: 2000
- Subjects: Environmental education Corporations -- environmental aspects Local government -- environmental aspects Managerial economics -- environmental aspects
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1543 , http://hdl.handle.net/10962/d1003425
- Description: The aim of this research was to explore how participants made meaning in an environmental education and training course for people from industry, business and local government in South Africa, and to identify and comment on any constraints to this meaning-making. I used a Symbolic Interactionist theoretical framework to explore and comment on the meaning-making process. I started my research by conducting a questionnaire to select participants for interviews. During the course the selected participants were interviewed, as well as the two course co-ordinators. Data was also gathered during the course from participant observation field notes ('captured talk'), photographs, participants' assignments and course evaluations. The data was analysed using an adapted form of discourse analysis and matrices. The research highlights that the opportunities provided on the course were adequate for encouraging meaning-making amongst both the co-ordinators and participants. However, recorded instances of meaning-making were low, which indicated that there were certain constraints during the meaning-making process. This research highlights and comments on identified constraints such as time and workplace support. The research supports similar findings which emerged from research conducted on the Gold Fields environmental education course for teachers and also offers recommendations for further research and practice into meaning-;making within the field of environmental education and industry, business and local government in South Africa.
- Full Text:
- Date Issued: 2000
Social change and shifting paradigms: the choice of healer among black South Africans in psychological counselling
- Authors: Johnson, Alexandra Blythe
- Date: 2000
- Subjects: Healers -- South Africa , Psychotherapy Cross-cultural studies , Xhosa (African people) -- Psychology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2998 , http://hdl.handle.net/10962/d1002507 , Healers -- South Africa , Psychotherapy Cross-cultural studies , Xhosa (African people) -- Psychology
- Description: Social change in South Africa brings to light the multiplicity of world-views operating in our society, which individuals encountering a variety of social contexts are faced with. This raises questions about the choices black South Africans face in response to influences from Western and traditional African culture. This issue was approached through examining helpseeking choices made between different health care sectors that stem from different world-views. This would indicate whether individuals are drawing on a variety of belief systems. The sources of their beliefs are put into context by looking at the communities of practice that influence their local knowledge. Help-seeking is also influenced by the identities the individual may ascribe to, which are derived from the multiple positions held by them in different social contexts. In this research the use of health-care sectors by four black women attending psychotherapy is examined. Their use of these sectors reflects a potential multiplicity of world views. Semistructured interviews were conducted, focusing on participants' prior experience of different help options, and their current perceptions of traditional African healing and psychology. The texts were analysed using a qualitative hermeneutic method, the reading guide. Data was looked at through three main themes, the individual's relationship to the health care sectors, their knowledge of different world views, and the identities they adopted which may be influential in their choice of a healer. It was found that in two participants there was some movement away from traditional beliefs, with one rejecting the traditional healers who did not help her, once she has discovered therapy, and another identifying herself completely with Western medicine. In contrast, one participant illustrated a rediscovery of traditional healing, whilst still attending psychotherapy. This suggests that shifts in knowledge are not necessarily away from traditional beliefs. It was also found that the two participants who had experienced a broader variety of social contexts and identified with multiple belief systems, tended to use a variety of Western and traditional healing sources and selected the healing option they felt was most appropriate to a particular problem. It is argued therefore that having a variety of knowledge and beliefs places individuals in a more powerful position to determine their choice of action than those with a limited range of knowledge.
- Full Text:
- Date Issued: 2000
- Authors: Johnson, Alexandra Blythe
- Date: 2000
- Subjects: Healers -- South Africa , Psychotherapy Cross-cultural studies , Xhosa (African people) -- Psychology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2998 , http://hdl.handle.net/10962/d1002507 , Healers -- South Africa , Psychotherapy Cross-cultural studies , Xhosa (African people) -- Psychology
- Description: Social change in South Africa brings to light the multiplicity of world-views operating in our society, which individuals encountering a variety of social contexts are faced with. This raises questions about the choices black South Africans face in response to influences from Western and traditional African culture. This issue was approached through examining helpseeking choices made between different health care sectors that stem from different world-views. This would indicate whether individuals are drawing on a variety of belief systems. The sources of their beliefs are put into context by looking at the communities of practice that influence their local knowledge. Help-seeking is also influenced by the identities the individual may ascribe to, which are derived from the multiple positions held by them in different social contexts. In this research the use of health-care sectors by four black women attending psychotherapy is examined. Their use of these sectors reflects a potential multiplicity of world views. Semistructured interviews were conducted, focusing on participants' prior experience of different help options, and their current perceptions of traditional African healing and psychology. The texts were analysed using a qualitative hermeneutic method, the reading guide. Data was looked at through three main themes, the individual's relationship to the health care sectors, their knowledge of different world views, and the identities they adopted which may be influential in their choice of a healer. It was found that in two participants there was some movement away from traditional beliefs, with one rejecting the traditional healers who did not help her, once she has discovered therapy, and another identifying herself completely with Western medicine. In contrast, one participant illustrated a rediscovery of traditional healing, whilst still attending psychotherapy. This suggests that shifts in knowledge are not necessarily away from traditional beliefs. It was also found that the two participants who had experienced a broader variety of social contexts and identified with multiple belief systems, tended to use a variety of Western and traditional healing sources and selected the healing option they felt was most appropriate to a particular problem. It is argued therefore that having a variety of knowledge and beliefs places individuals in a more powerful position to determine their choice of action than those with a limited range of knowledge.
- Full Text:
- Date Issued: 2000
Investigation into the provision of service excellence in a selected bank in the Port Elizabeth metropole
- Authors: Keet, Marius
- Date: 2000
- Subjects: Banks and banking -- South Africa , Bank management , Consumer satisfaction , Quality assurance -- Management
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10838 , http://hdl.handle.net/10948/31 , Banks and banking -- South Africa , Bank management , Consumer satisfaction , Quality assurance -- Management
- Description: In this research customer service excellence in First National Bank in the Port Elizabeth metropole was investigated. From the industry and competitor analysis it can be concluded that banking is a highly competitive industry that is undergoing constant change because of fierce competition. The literature survey was aimed at placing the concept of service quality, excellence and customer loyalty which lead to customer retention into perspective. The concept of total quality management outlining the specific requirements of how the concept can be utilised and how a service quality programme can be implemented was discussed. The purpose of the empirical study was to test customers’ perceptions of service provided by First National Bank and to contribute with useful information to the bank studied. From these findings improvements and recommendations were suggested as a guideline for any bank to follow to improve customer service levels. The empirical study results were satisfactory and informative. The meaningful positive responses that were identified can be utilised as competitive marketing strategies by FNB. The meaningful negative concerns the bank should consider improving upon and attention should be given to the language and SBU differences outlined.
- Full Text:
- Date Issued: 2000
- Authors: Keet, Marius
- Date: 2000
- Subjects: Banks and banking -- South Africa , Bank management , Consumer satisfaction , Quality assurance -- Management
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10838 , http://hdl.handle.net/10948/31 , Banks and banking -- South Africa , Bank management , Consumer satisfaction , Quality assurance -- Management
- Description: In this research customer service excellence in First National Bank in the Port Elizabeth metropole was investigated. From the industry and competitor analysis it can be concluded that banking is a highly competitive industry that is undergoing constant change because of fierce competition. The literature survey was aimed at placing the concept of service quality, excellence and customer loyalty which lead to customer retention into perspective. The concept of total quality management outlining the specific requirements of how the concept can be utilised and how a service quality programme can be implemented was discussed. The purpose of the empirical study was to test customers’ perceptions of service provided by First National Bank and to contribute with useful information to the bank studied. From these findings improvements and recommendations were suggested as a guideline for any bank to follow to improve customer service levels. The empirical study results were satisfactory and informative. The meaningful positive responses that were identified can be utilised as competitive marketing strategies by FNB. The meaningful negative concerns the bank should consider improving upon and attention should be given to the language and SBU differences outlined.
- Full Text:
- Date Issued: 2000
An investigation into the effects of socio-economic and education factors on WAIS-III performance in a stratified South African sample
- Authors: Kemp, Ryan
- Date: 2000
- Subjects: Wechsler Adult Intelligence Scale -- South Africa , Intelligence tests -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3002 , http://hdl.handle.net/10962/d1002511 , Wechsler Adult Intelligence Scale -- South Africa , Intelligence tests -- South Africa
- Description: The present study examined the effects of socio-economic status, quality and level of education on performance on the Wechsler Adult Intelligence Scale 3rd Edition r.:w AIS-III). The study was conducted within the context of the present Human Sciences Research Council (HSRC) W AIS-III standardisation process, cross-cultural psychometric research and the notion of test-wiseness. A South African sample (N = 68) comprising African first language (n = 40) and English first language (n = 28) participants, stratified for age (19 - 30 years), gender and educational attainment (Matric and Graduate) were utilised. Effects due to quality of education were determined by dividing the African language participants into those with private/model C schooling (n = 20) and those with DET schooling (n = 20). Effects due to level of education were determined by dividing the entire sample into those with Matric level education (n = 34) and those with Graduate level education (n = 34). Detailed demographic and socio-economic information were recorded for all participants, who completed the entire American version of the W AIS-III. Results revealed a highly significant positive correlation between high socio-economic status and W AIS-III Full Scale IQ. In addition the respective impact of the relatively poor quality of education and lower level of educational attainment on W AIS-III performance was substantial. These results were discussed in terms of their implications for cross-cultural research, the HSRC standardisation of the W AIS-III and the practical use of the W AIS-III in neuropsychological assessment.
- Full Text:
- Date Issued: 2000
- Authors: Kemp, Ryan
- Date: 2000
- Subjects: Wechsler Adult Intelligence Scale -- South Africa , Intelligence tests -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3002 , http://hdl.handle.net/10962/d1002511 , Wechsler Adult Intelligence Scale -- South Africa , Intelligence tests -- South Africa
- Description: The present study examined the effects of socio-economic status, quality and level of education on performance on the Wechsler Adult Intelligence Scale 3rd Edition r.:w AIS-III). The study was conducted within the context of the present Human Sciences Research Council (HSRC) W AIS-III standardisation process, cross-cultural psychometric research and the notion of test-wiseness. A South African sample (N = 68) comprising African first language (n = 40) and English first language (n = 28) participants, stratified for age (19 - 30 years), gender and educational attainment (Matric and Graduate) were utilised. Effects due to quality of education were determined by dividing the African language participants into those with private/model C schooling (n = 20) and those with DET schooling (n = 20). Effects due to level of education were determined by dividing the entire sample into those with Matric level education (n = 34) and those with Graduate level education (n = 34). Detailed demographic and socio-economic information were recorded for all participants, who completed the entire American version of the W AIS-III. Results revealed a highly significant positive correlation between high socio-economic status and W AIS-III Full Scale IQ. In addition the respective impact of the relatively poor quality of education and lower level of educational attainment on W AIS-III performance was substantial. These results were discussed in terms of their implications for cross-cultural research, the HSRC standardisation of the W AIS-III and the practical use of the W AIS-III in neuropsychological assessment.
- Full Text:
- Date Issued: 2000
Effects of sustained elevated CO2 concentration and Nitrogen nutrition on wheat (Triticum aestivum L. cv Gamtoos)
- Authors: Kgope, Barney Stephen
- Date: 2000
- Subjects: Wheat -- Growth , Wheat -- Nutrition , Nitrogen fertilizers , Nitrogen in agriculture
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4205 , http://hdl.handle.net/10962/d1003774 , Wheat -- Growth , Wheat -- Nutrition , Nitrogen fertilizers , Nitrogen in agriculture
- Description: There is consensus that high CO2 results in enhanced growth and yield for most crop plants. However, most of these studies were carried out in the presence of adequate nutrients, which is also the case in agricultural systems (managed ecosystems). About 20% of the earth’s land mass have sufficiently low levels of nutrients to cause some kind of stress to plants. On the other hand, elevated [CO2] decreases foliar nutrient elements in plants and as a result partitioning of certain nutrient elements in plants is altered. Little data is available on the partitioning of most nutrient elements in plants, and this will definitely impact on growth and yield. To investigate this, wheat (Triticum aestivum L. c.v. Gamtoos) was grown in controlled environment cabinets at 360 and 700 µmol mol -1 CO2. The full Long-Ashton nutrient solution comprising of three-nitrogen concentrations ([N]) viz. (4,6 and 12 mM) was used to water plants everyday. The measurement of net assimilation rate (NAR), stomatal conductance (gs), transpiration rate (E), water use efficiency (WUE), foliar [N], nitrogen use efficiency (NUE) and growth parameters (total plant biomass (TPB), total plant height (TPH), leaf area (LA), shoot and root dry weight) were made 7 days after germination (7 DAG) till the onset of flowering. The increase in nitrogen supply in the order of 4, 6 and 12mM resulted in an increase in NAR, g_s_ , WUE and a decline in E under elevated [CO2]. Under elevated [CO2] NAR was observed to increase during the first two weeks reaching its maximum at 14 DAG, thereafter followed by a decline reaching its maximum at 28 DAG. This was later followed by an increase at 35 DAG onwards. Under elevated [CO2], NAR was increased significantly between the nitrogen regimes during the first (7-14 DAG) and the last two (35-42 DAG) weeks. The response of assimilation as a function of internal [CO2] (Ci), showed a decrease with age at ages 14, 28 and 35 DAG. This negatively affected the initial slope and the CO2 saturated photosynthetic rates under all treatments. This suggest that acclimation may have been as a result of both stomatal and biochemical limitations. All the photosynthetic pigment levels (chl_a_, chl_b_, chl_(a+b)_, and C_(x+c)_ ) increased with an increase in nitrogen supply from 4 to 6mM [N]. A 12mM [N] resulted in a significant decline in the photosynthetic pigment levels compared to a 6mM [N]. Chla remained higher than chlb under all treatments. Also, NAR was seen to increase and decrease concomitantly with the photosynthetic pigment levels. Foliar [N] was seen to decrease with an increase in nitrogen supply from 4 to 6 mM [N] under elevated [CO2] and the effects were adverse under the 4mM [N]. Under the 6mM N regime foliar [N] was positively correlated to NAR for elevated [CO2] grown plants. Similarly, E was positively correlated to foliar [N] under the same conditions. Elevated CO2 and increase in nitrogen supply had a pronounced effect on total plant height (TPH), total plant biomass (TPB), leaf area (LA), shoot and root dry weight and nitrogen use efficiency (NUE). The effects were more pronounced under a 6mM [N] as a result of high NUE. However, under 12mM [N] growth was not as expected as a result of lower NUE. Under all treatments shoot dry weight (SDW) was positively correlated to NUE. Anatomical studies revealed that total leaf and midrib thickness was significantly increased with an increase in nitrogen supply under elevated CO2 to support the larger leaf areas. There were no significant changes in the chloroplast ultrastructure as a result of the increase in nitrogen supply and CO2 enrichment. Starch grain surface area was seen to decline with an increase in nitrogen under both ambient and elevated CO2. Elevated CO2 and increase in nitrogen supply significantly increased total grain dry weight per plant by 47 and 46% respectively under 6 and 12mM [N]. In contrast, the increase was by about 21, 61 and 67% respectively under 4, 6 and 12mM [N] between the CO2 regimes.
- Full Text:
- Date Issued: 2000
- Authors: Kgope, Barney Stephen
- Date: 2000
- Subjects: Wheat -- Growth , Wheat -- Nutrition , Nitrogen fertilizers , Nitrogen in agriculture
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4205 , http://hdl.handle.net/10962/d1003774 , Wheat -- Growth , Wheat -- Nutrition , Nitrogen fertilizers , Nitrogen in agriculture
- Description: There is consensus that high CO2 results in enhanced growth and yield for most crop plants. However, most of these studies were carried out in the presence of adequate nutrients, which is also the case in agricultural systems (managed ecosystems). About 20% of the earth’s land mass have sufficiently low levels of nutrients to cause some kind of stress to plants. On the other hand, elevated [CO2] decreases foliar nutrient elements in plants and as a result partitioning of certain nutrient elements in plants is altered. Little data is available on the partitioning of most nutrient elements in plants, and this will definitely impact on growth and yield. To investigate this, wheat (Triticum aestivum L. c.v. Gamtoos) was grown in controlled environment cabinets at 360 and 700 µmol mol -1 CO2. The full Long-Ashton nutrient solution comprising of three-nitrogen concentrations ([N]) viz. (4,6 and 12 mM) was used to water plants everyday. The measurement of net assimilation rate (NAR), stomatal conductance (gs), transpiration rate (E), water use efficiency (WUE), foliar [N], nitrogen use efficiency (NUE) and growth parameters (total plant biomass (TPB), total plant height (TPH), leaf area (LA), shoot and root dry weight) were made 7 days after germination (7 DAG) till the onset of flowering. The increase in nitrogen supply in the order of 4, 6 and 12mM resulted in an increase in NAR, g_s_ , WUE and a decline in E under elevated [CO2]. Under elevated [CO2] NAR was observed to increase during the first two weeks reaching its maximum at 14 DAG, thereafter followed by a decline reaching its maximum at 28 DAG. This was later followed by an increase at 35 DAG onwards. Under elevated [CO2], NAR was increased significantly between the nitrogen regimes during the first (7-14 DAG) and the last two (35-42 DAG) weeks. The response of assimilation as a function of internal [CO2] (Ci), showed a decrease with age at ages 14, 28 and 35 DAG. This negatively affected the initial slope and the CO2 saturated photosynthetic rates under all treatments. This suggest that acclimation may have been as a result of both stomatal and biochemical limitations. All the photosynthetic pigment levels (chl_a_, chl_b_, chl_(a+b)_, and C_(x+c)_ ) increased with an increase in nitrogen supply from 4 to 6mM [N]. A 12mM [N] resulted in a significant decline in the photosynthetic pigment levels compared to a 6mM [N]. Chla remained higher than chlb under all treatments. Also, NAR was seen to increase and decrease concomitantly with the photosynthetic pigment levels. Foliar [N] was seen to decrease with an increase in nitrogen supply from 4 to 6 mM [N] under elevated [CO2] and the effects were adverse under the 4mM [N]. Under the 6mM N regime foliar [N] was positively correlated to NAR for elevated [CO2] grown plants. Similarly, E was positively correlated to foliar [N] under the same conditions. Elevated CO2 and increase in nitrogen supply had a pronounced effect on total plant height (TPH), total plant biomass (TPB), leaf area (LA), shoot and root dry weight and nitrogen use efficiency (NUE). The effects were more pronounced under a 6mM [N] as a result of high NUE. However, under 12mM [N] growth was not as expected as a result of lower NUE. Under all treatments shoot dry weight (SDW) was positively correlated to NUE. Anatomical studies revealed that total leaf and midrib thickness was significantly increased with an increase in nitrogen supply under elevated CO2 to support the larger leaf areas. There were no significant changes in the chloroplast ultrastructure as a result of the increase in nitrogen supply and CO2 enrichment. Starch grain surface area was seen to decline with an increase in nitrogen under both ambient and elevated CO2. Elevated CO2 and increase in nitrogen supply significantly increased total grain dry weight per plant by 47 and 46% respectively under 6 and 12mM [N]. In contrast, the increase was by about 21, 61 and 67% respectively under 4, 6 and 12mM [N] between the CO2 regimes.
- Full Text:
- Date Issued: 2000
The utilisation of Asolla filiculoides Lam. as a biofertiliser under dryland conditions
- Authors: Kiguli, Lillian Nakibuuka
- Date: 2000
- Subjects: Asolla as fertilizer
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4206 , http://hdl.handle.net/10962/d1003775 , Asolla as fertilizer
- Description: The response of wheat to soil fertilised with varying quantities of the water fern Azolla filiculoides was investigated. Experiments were conducted to differentiate between the effects of increased soil mineral status and water status. In the preliminary investigation, experiments were carried out in the greenhouse using potted wheat grown in sand with varying proportions of A. filiculoides that had been subjected tovarious pre-treatments. The pre-treatments were fresh, dry and heated A. filiculoides applied at 20%, 50% and 80% volume per 3000 ml. There were significant differences in the measured growth parameters between the plants grown in the various treatments. In addition, the grain yield of wheat plants varied with the different treatments. Results of the preliminary study showed that the addition of heated and dried A. filiculoides resulted in significantly better growth than the addition of fresh A. filiculoides in sand. For fresh biomass, grain weights, Leaf area ratio (LAR) and relative growth rate (RGR), the performance of dried A. filiculoides was as good as that of the heated A. filiculoides. Productivity of wheat in the heated treatments increased significantly with increasing proportion of A. filiculoides added to sand, while in dry treatments there were no significant increases in productivity in the preliminary study. This supported the hypothesis that A. filiculoides, a notorious water weed can be put to agricultural use under dryland conditions in poor nutrient soils. Further investigations using dried A. filiculoides in sand and topsoil showed that the use of the same amounts of the dried fern made no significant short term impact on topsoil grown winter wheat but significantly improved the productivity of wheat in sand. Results showed that the addition of dried 20% Azolla to sand improved the soil fertility to levels equalling the quality of the control topsoil, but the addition of 80% Azolla to sand led to significantly greater wheat productivity than all other treatments. The addition of dried 20% Azolla (8.14 × 10^3 kg ha^(-1)) in sand produced as much wheat biomass as the addition of the recommended NPK fertiliser (30 kg N ha^(-1)) to sand. A comparison between the topsoil and sand-grown plants showed differences in flowering time but these had no effect on the final grain and above ground biomass.
- Full Text:
- Date Issued: 2000
- Authors: Kiguli, Lillian Nakibuuka
- Date: 2000
- Subjects: Asolla as fertilizer
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4206 , http://hdl.handle.net/10962/d1003775 , Asolla as fertilizer
- Description: The response of wheat to soil fertilised with varying quantities of the water fern Azolla filiculoides was investigated. Experiments were conducted to differentiate between the effects of increased soil mineral status and water status. In the preliminary investigation, experiments were carried out in the greenhouse using potted wheat grown in sand with varying proportions of A. filiculoides that had been subjected tovarious pre-treatments. The pre-treatments were fresh, dry and heated A. filiculoides applied at 20%, 50% and 80% volume per 3000 ml. There were significant differences in the measured growth parameters between the plants grown in the various treatments. In addition, the grain yield of wheat plants varied with the different treatments. Results of the preliminary study showed that the addition of heated and dried A. filiculoides resulted in significantly better growth than the addition of fresh A. filiculoides in sand. For fresh biomass, grain weights, Leaf area ratio (LAR) and relative growth rate (RGR), the performance of dried A. filiculoides was as good as that of the heated A. filiculoides. Productivity of wheat in the heated treatments increased significantly with increasing proportion of A. filiculoides added to sand, while in dry treatments there were no significant increases in productivity in the preliminary study. This supported the hypothesis that A. filiculoides, a notorious water weed can be put to agricultural use under dryland conditions in poor nutrient soils. Further investigations using dried A. filiculoides in sand and topsoil showed that the use of the same amounts of the dried fern made no significant short term impact on topsoil grown winter wheat but significantly improved the productivity of wheat in sand. Results showed that the addition of dried 20% Azolla to sand improved the soil fertility to levels equalling the quality of the control topsoil, but the addition of 80% Azolla to sand led to significantly greater wheat productivity than all other treatments. The addition of dried 20% Azolla (8.14 × 10^3 kg ha^(-1)) in sand produced as much wheat biomass as the addition of the recommended NPK fertiliser (30 kg N ha^(-1)) to sand. A comparison between the topsoil and sand-grown plants showed differences in flowering time but these had no effect on the final grain and above ground biomass.
- Full Text:
- Date Issued: 2000