Sunday Times: Celebrating Women
- Authors: Sunday Times
- Date: 2010
- Subjects: Nyokong, Tebello
- Language: English
- Type: Article , text
- Identifier: vital:7187 , http://hdl.handle.net/10962/d1006279 , Nyokong, Tebello
- Description: A passion for light drove Professor Tebello Nyokong of Rhodes University into her photodynamic therapy research, harnessing light for cancer therapy and environmental clean-up using special dyes. And with this groundbreaking work she won the Africa-Arab State 2009 L'Oreal UNESCO Award for Women in Science.
- Full Text:
- Date Issued: 2010
- Authors: Sunday Times
- Date: 2010
- Subjects: Nyokong, Tebello
- Language: English
- Type: Article , text
- Identifier: vital:7187 , http://hdl.handle.net/10962/d1006279 , Nyokong, Tebello
- Description: A passion for light drove Professor Tebello Nyokong of Rhodes University into her photodynamic therapy research, harnessing light for cancer therapy and environmental clean-up using special dyes. And with this groundbreaking work she won the Africa-Arab State 2009 L'Oreal UNESCO Award for Women in Science.
- Full Text:
- Date Issued: 2010
Developing an ionospheric map for South Africa
- McKinnell, Lee-Anne, Okoh, D I, Cilliers, P J
- Authors: McKinnell, Lee-Anne , Okoh, D I , Cilliers, P J
- Date: 2010
- Language: English
- Type: Article
- Identifier: vital:6822 , http://hdl.handle.net/10962/d1004438 , http://dx.doi.org/10.5194/angeo-28-1431-2010
- Description: The development of a map of the ionosphere over South Africa is presented in this paper. The International Reference Ionosphere (IRI) model, South African Bottomside Ionospheric Model (SABIM), and measurements from ionosondes in the South African Ionosonde Network, were combined within their own limitations to develop an accurate representation of the South African ionosphere. The map is essentially in the form of a computer program that shows spatial and temporal representations of the South African ionosphere for a given set of geophysical parameters. A validation of the map is attempted using a comparison of Total Electron Content (TEC) values derived from the map, from the IRI model, and from Global Positioning System (GPS) measurements. It is foreseen that the final South African ionospheric map will be implemented as a Space Weather product of the African Space Weather Regional Warning Centre.
- Full Text:
- Date Issued: 2010
- Authors: McKinnell, Lee-Anne , Okoh, D I , Cilliers, P J
- Date: 2010
- Language: English
- Type: Article
- Identifier: vital:6822 , http://hdl.handle.net/10962/d1004438 , http://dx.doi.org/10.5194/angeo-28-1431-2010
- Description: The development of a map of the ionosphere over South Africa is presented in this paper. The International Reference Ionosphere (IRI) model, South African Bottomside Ionospheric Model (SABIM), and measurements from ionosondes in the South African Ionosonde Network, were combined within their own limitations to develop an accurate representation of the South African ionosphere. The map is essentially in the form of a computer program that shows spatial and temporal representations of the South African ionosphere for a given set of geophysical parameters. A validation of the map is attempted using a comparison of Total Electron Content (TEC) values derived from the map, from the IRI model, and from Global Positioning System (GPS) measurements. It is foreseen that the final South African ionospheric map will be implemented as a Space Weather product of the African Space Weather Regional Warning Centre.
- Full Text:
- Date Issued: 2010
Improving sanitization and fertiliser value of dairy manure and waste paper mixtures enriched with rock phosphate through combined thermophilic composting and vermicomposting
- Authors: Mupondi, Lushian Tapiwa
- Date: 2010
- Subjects: Compost , Vermicomposting , Manures , Biodegradation , Waste paper -- South Africa -- Eastern Cape , Thermophilic bacteria , Fertilizers
- Language: English
- Type: Thesis , Doctoral , PhD (Soil Science)
- Identifier: vital:11961 , http://hdl.handle.net/10353/411 , Compost , Vermicomposting , Manures , Biodegradation , Waste paper -- South Africa -- Eastern Cape , Thermophilic bacteria , Fertilizers
- Description: Thermophilic composting (TC) and vermicomposting (V) are the two most common methods used for biological stabilization of solid organic wastes. Both have their advantages and disadvantages but the proposed method of combining composting and vermicomposting (CV) borrows pertinent attributes from each of the two methods and combines them to enhance overall process and product qualities. Dairy manure and waste paper are two wastes produced in large quantities at the University of Fort Hare. The study was carried out to address the following specific objectives, to determine (i) the effectiveness of combined thermophilic composting and vermicomposting on the biodegradation and sanitization of mixtures of dairy manure and paper waste, (ii) an optimum precomposting period for dairy manure paper waste mixtures that results in vermicomposts of good nutritional quality and whose use will not jeopardize human health, (iii) the effectiveness of phosphate rock (PR) in increasing available P and degradation and nutrient content of dairy manure-paper vermicomposts, (iv) the physicochemical properties of vermicompost substituted pine bark compost and performance of resultant growing medium on plant growth and nutrient uptake. Results of this study revealed that wastes with a C: N ratio of 30 were more suitable for both V and CV as their composts were more stabilized and with higher nutrient contents than composts made from wastes with a C: N ratio of 45. Both V and CV were effective methods for the biodegradation of dairy manure and paper waste mixtures with C: N ratio of 30 but the latter was more effective in the biodegradation of waste mixtures with a C: N ratio of 45. The combinination of composting and vermicomposting eliminated the indicator pathogen E. coli 0157 from the final composts whereas V only managed to reduce the pathogen population. iv A follow up study was done to determine the effects of precomposting on pathogen numbers so as to come up with a suitable precomposting period to use when combine composting dairy manure-waste paper mixtures. Results of this study showed that over 95% of fecal coliforms, E. coli and of E. coli 0157 were eliminated from the wastes within one week of precomposting and total elimination of these and protozoan (oo)cysts achieved after 3 weeks of precomposting. The vermicomposts pathogen content was related to the waste’s precomposting period. Final vermicomposts pathogen content was reduced and varied according to precomposting period. Vermicomposts from wastes precomposted for over two weeks were less stabilized, less humified and had less nutrient contents compared to vermicomposts from wastes that were precomposted for one week or less. The findings suggest that a precomposting period of one week is ideal for the effective vermicomposting of dairy manure-waste paper mixtures. Results of the P enrichment study indicated an increase in the inorganic phosphate and a reduction in the organic phosphate fractions of dairy manure-waste paper vermicompost that were enriched with PR. This implied an increase in mineralization of organic matter and or solubilization of PR with vermicomposting time. Applying PR to dairy manure-waste paper mixtures also enhanced degradation and had increased N and P contents of dairy manure-waste paper vermicomposts. Earthworms accumulated heavy metals in their bodies and reduced heavy metal contents of vermicomposts. A study to determine the physicochemical properties of vermicompost substituted pine bark compost and performance of resultant growing medium on plant growth and nutrient uptake was done. Results obtained revealed that increasing proportions of dairy manure vermicomposts in pine bark compost improved tomato plant height, stem girth, shoot and root dry weights. v Tomatoes grew best in the 40 to 60% CV substituted pine bark and application of Horticote (7:2:1 (22)) fertilizer significantly increased plant growth in all media. Progressive substitution pine bark with dairy manure vermicomposts resulted in a decrease in the percentage total porosity, percentage air space whilst bulk density, water holding capacity, particle density, pH, electrical conductivity and N and P levels increased. Precomposting wastes not only reduced and or eliminated pathogens but also improved the stabilisation and nutrient content of dairy manure waste paper mixtures. The application of PR to dairy manure waste paper mixtures improved the chemical and physical properties of vermicomposts. Earthworms bio-accumulated the heavy metals Cd, Cr, Cu, Pb and Zn whilst the contents of these in the vermicomposts declined. It is, therefore, recommended that dairy manure waste paper mixtures be precomposted for one week for sanitization followed by PR application and vermicomposting for stabilization and improved nutrients contents of resultant vermicomposts. Substitution of pine bark compost with 40 to 60 % PR-enriched vermicompost produced a growing medium with superior physical and chemical properties which supported good seedling growth. However, for optimum seedling growth, supplementation with mineral fertilizer was found to be necessary.
- Full Text:
- Date Issued: 2010
- Authors: Mupondi, Lushian Tapiwa
- Date: 2010
- Subjects: Compost , Vermicomposting , Manures , Biodegradation , Waste paper -- South Africa -- Eastern Cape , Thermophilic bacteria , Fertilizers
- Language: English
- Type: Thesis , Doctoral , PhD (Soil Science)
- Identifier: vital:11961 , http://hdl.handle.net/10353/411 , Compost , Vermicomposting , Manures , Biodegradation , Waste paper -- South Africa -- Eastern Cape , Thermophilic bacteria , Fertilizers
- Description: Thermophilic composting (TC) and vermicomposting (V) are the two most common methods used for biological stabilization of solid organic wastes. Both have their advantages and disadvantages but the proposed method of combining composting and vermicomposting (CV) borrows pertinent attributes from each of the two methods and combines them to enhance overall process and product qualities. Dairy manure and waste paper are two wastes produced in large quantities at the University of Fort Hare. The study was carried out to address the following specific objectives, to determine (i) the effectiveness of combined thermophilic composting and vermicomposting on the biodegradation and sanitization of mixtures of dairy manure and paper waste, (ii) an optimum precomposting period for dairy manure paper waste mixtures that results in vermicomposts of good nutritional quality and whose use will not jeopardize human health, (iii) the effectiveness of phosphate rock (PR) in increasing available P and degradation and nutrient content of dairy manure-paper vermicomposts, (iv) the physicochemical properties of vermicompost substituted pine bark compost and performance of resultant growing medium on plant growth and nutrient uptake. Results of this study revealed that wastes with a C: N ratio of 30 were more suitable for both V and CV as their composts were more stabilized and with higher nutrient contents than composts made from wastes with a C: N ratio of 45. Both V and CV were effective methods for the biodegradation of dairy manure and paper waste mixtures with C: N ratio of 30 but the latter was more effective in the biodegradation of waste mixtures with a C: N ratio of 45. The combinination of composting and vermicomposting eliminated the indicator pathogen E. coli 0157 from the final composts whereas V only managed to reduce the pathogen population. iv A follow up study was done to determine the effects of precomposting on pathogen numbers so as to come up with a suitable precomposting period to use when combine composting dairy manure-waste paper mixtures. Results of this study showed that over 95% of fecal coliforms, E. coli and of E. coli 0157 were eliminated from the wastes within one week of precomposting and total elimination of these and protozoan (oo)cysts achieved after 3 weeks of precomposting. The vermicomposts pathogen content was related to the waste’s precomposting period. Final vermicomposts pathogen content was reduced and varied according to precomposting period. Vermicomposts from wastes precomposted for over two weeks were less stabilized, less humified and had less nutrient contents compared to vermicomposts from wastes that were precomposted for one week or less. The findings suggest that a precomposting period of one week is ideal for the effective vermicomposting of dairy manure-waste paper mixtures. Results of the P enrichment study indicated an increase in the inorganic phosphate and a reduction in the organic phosphate fractions of dairy manure-waste paper vermicompost that were enriched with PR. This implied an increase in mineralization of organic matter and or solubilization of PR with vermicomposting time. Applying PR to dairy manure-waste paper mixtures also enhanced degradation and had increased N and P contents of dairy manure-waste paper vermicomposts. Earthworms accumulated heavy metals in their bodies and reduced heavy metal contents of vermicomposts. A study to determine the physicochemical properties of vermicompost substituted pine bark compost and performance of resultant growing medium on plant growth and nutrient uptake was done. Results obtained revealed that increasing proportions of dairy manure vermicomposts in pine bark compost improved tomato plant height, stem girth, shoot and root dry weights. v Tomatoes grew best in the 40 to 60% CV substituted pine bark and application of Horticote (7:2:1 (22)) fertilizer significantly increased plant growth in all media. Progressive substitution pine bark with dairy manure vermicomposts resulted in a decrease in the percentage total porosity, percentage air space whilst bulk density, water holding capacity, particle density, pH, electrical conductivity and N and P levels increased. Precomposting wastes not only reduced and or eliminated pathogens but also improved the stabilisation and nutrient content of dairy manure waste paper mixtures. The application of PR to dairy manure waste paper mixtures improved the chemical and physical properties of vermicomposts. Earthworms bio-accumulated the heavy metals Cd, Cr, Cu, Pb and Zn whilst the contents of these in the vermicomposts declined. It is, therefore, recommended that dairy manure waste paper mixtures be precomposted for one week for sanitization followed by PR application and vermicomposting for stabilization and improved nutrients contents of resultant vermicomposts. Substitution of pine bark compost with 40 to 60 % PR-enriched vermicompost produced a growing medium with superior physical and chemical properties which supported good seedling growth. However, for optimum seedling growth, supplementation with mineral fertilizer was found to be necessary.
- Full Text:
- Date Issued: 2010
Advanced monitoring system for bolted connections in vehicle construction
- Authors: Buchmann, Macro
- Date: 2010
- Subjects: Automobiles -- Design and construction , Motor vehicles -- Design and construction , Bolted joints
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9617 , http://hdl.handle.net/10948/1417 , Automobiles -- Design and construction , Motor vehicles -- Design and construction , Bolted joints
- Description: Bolted connections where used from the beginning of vehicle construction for joining two or more parts. The reliability of bolted connections is still a major problem. The objective of this research thesis is focused on an advanced monitoring system for bolted connections in vehicle construction. A mechanical “vibrating test bench”, which was developed by the aeronautical engineer Mr. Junkers, is being adapted, to suite the requirements of the automotive industry. It is designed according to DIN 65151 standards. The bolted connection is tightened to a specific torque to achieve the required preload forces and then exposed to an oscillating elastic shear force. The preload force and their loss are measured in relation to the number of load cycles. The ideal locking mechanism would be, if no settling occurs. Realistic in practice is the remaining of a sufficient preload force which doesn’t decry with time. The aim of this thesis is, to gain knowledge that will assist in the future control of the bolt locking procedure. The test bench can be used to verify the clamping capability of a bolted connection. With the dynamic computer-aided test system it will also be possible to test critical bolted joints and their safety, which reduces the probability of costly product recalls, or even severe cases of failure.
- Full Text:
- Date Issued: 2010
- Authors: Buchmann, Macro
- Date: 2010
- Subjects: Automobiles -- Design and construction , Motor vehicles -- Design and construction , Bolted joints
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9617 , http://hdl.handle.net/10948/1417 , Automobiles -- Design and construction , Motor vehicles -- Design and construction , Bolted joints
- Description: Bolted connections where used from the beginning of vehicle construction for joining two or more parts. The reliability of bolted connections is still a major problem. The objective of this research thesis is focused on an advanced monitoring system for bolted connections in vehicle construction. A mechanical “vibrating test bench”, which was developed by the aeronautical engineer Mr. Junkers, is being adapted, to suite the requirements of the automotive industry. It is designed according to DIN 65151 standards. The bolted connection is tightened to a specific torque to achieve the required preload forces and then exposed to an oscillating elastic shear force. The preload force and their loss are measured in relation to the number of load cycles. The ideal locking mechanism would be, if no settling occurs. Realistic in practice is the remaining of a sufficient preload force which doesn’t decry with time. The aim of this thesis is, to gain knowledge that will assist in the future control of the bolt locking procedure. The test bench can be used to verify the clamping capability of a bolted connection. With the dynamic computer-aided test system it will also be possible to test critical bolted joints and their safety, which reduces the probability of costly product recalls, or even severe cases of failure.
- Full Text:
- Date Issued: 2010
Fabrication and characterization of single walled carbon nanotubes-iron phthalocyanine nano-composite
- Akinbulu, Isaac A, Nyokong, Tebello
- Authors: Akinbulu, Isaac A , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/262622 , vital:53537 , xlink:href="https://doi.org/10.1039/C0NJ00395F"
- Description: Nano-composite of single walled carbon nanotubes (SWCNTs) and iron phthalocyanine, peripherally tetra-substituted with diethylaminoethanethiol (complex 2), was fabricated and characterized by infra red (IR) spectroscopy, X-ray diffraction (XRD) and transmission electron microscopy (TEM). TEM technique gave a convincing image of the nano-composite. Self-assembled monolayer (SAM) film of the composite (SWCNT-2-SAM) was formed on gold electrode. Its surface properties were investigated, relative to that of 2-SAM film, by cyclic voltammetry and scanning electron microscopy (SEM). Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry, using [Fe(CN)6]3− as redox probe, were used to investigate the dynamics of electron transport in the SWCNT-2-SAM film. Lower charge transfer resistance, RCT, of the SWCNT-2-SAM modified Au electrode, relative to that of the 2-SAM modified Au electrode, was an indication of enhanced electron transport in the presence of SWCNT. The SAM film of the nano-composite showed better electrocatalytic behaviour, relative to that of 2-SAM film, towards the oxidation of the insecticide, carbofuran. The electrode (SWCNT-2-SAM) showed good selectivity for carbofuran, in the presence of diazinon (a non-electroactive interferent) and at lower concentration of the electroactive interferents (chlorpyrifos and dichlorfos).
- Full Text:
- Date Issued: 2010
- Authors: Akinbulu, Isaac A , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/262622 , vital:53537 , xlink:href="https://doi.org/10.1039/C0NJ00395F"
- Description: Nano-composite of single walled carbon nanotubes (SWCNTs) and iron phthalocyanine, peripherally tetra-substituted with diethylaminoethanethiol (complex 2), was fabricated and characterized by infra red (IR) spectroscopy, X-ray diffraction (XRD) and transmission electron microscopy (TEM). TEM technique gave a convincing image of the nano-composite. Self-assembled monolayer (SAM) film of the composite (SWCNT-2-SAM) was formed on gold electrode. Its surface properties were investigated, relative to that of 2-SAM film, by cyclic voltammetry and scanning electron microscopy (SEM). Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry, using [Fe(CN)6]3− as redox probe, were used to investigate the dynamics of electron transport in the SWCNT-2-SAM film. Lower charge transfer resistance, RCT, of the SWCNT-2-SAM modified Au electrode, relative to that of the 2-SAM modified Au electrode, was an indication of enhanced electron transport in the presence of SWCNT. The SAM film of the nano-composite showed better electrocatalytic behaviour, relative to that of 2-SAM film, towards the oxidation of the insecticide, carbofuran. The electrode (SWCNT-2-SAM) showed good selectivity for carbofuran, in the presence of diazinon (a non-electroactive interferent) and at lower concentration of the electroactive interferents (chlorpyrifos and dichlorfos).
- Full Text:
- Date Issued: 2010
The development and implementation of computer literacy terminology in isiXhosa
- Authors: Sam, Msindisi Scara
- Date: 2010
- Subjects: Xhosa language -- Data processing Computer literacy -- South Africa -- Dwesa-Cwebe Computer literacy -- South Africa -- Grahamstown Information technology -- South Africa -- Dwesa-Cwebe Information technology -- South Africa -- Grahamstown Computational linguistics -- South Africa -- Dwesa-Cwebe Computational linguistics -- South Africa -- Grahamstown Information technology -- South Africa -- Dwesa-Cwebe -- Social aspects Information technology -- South Africa -- Grahamstown -- Social aspects Digital divide -- South Africa -- Dwesa-Cwebe Communication in economic development -- South Africa -- Dwesa-Cwebe Communication in economic development -- South Africa -- Grahamstown South Africa-Norway Tertiary Education Development Programme Rhodes University. Dept. of African Languages
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3580 , http://hdl.handle.net/10962/d1002155
- Full Text:
- Date Issued: 2010
- Authors: Sam, Msindisi Scara
- Date: 2010
- Subjects: Xhosa language -- Data processing Computer literacy -- South Africa -- Dwesa-Cwebe Computer literacy -- South Africa -- Grahamstown Information technology -- South Africa -- Dwesa-Cwebe Information technology -- South Africa -- Grahamstown Computational linguistics -- South Africa -- Dwesa-Cwebe Computational linguistics -- South Africa -- Grahamstown Information technology -- South Africa -- Dwesa-Cwebe -- Social aspects Information technology -- South Africa -- Grahamstown -- Social aspects Digital divide -- South Africa -- Dwesa-Cwebe Communication in economic development -- South Africa -- Dwesa-Cwebe Communication in economic development -- South Africa -- Grahamstown South Africa-Norway Tertiary Education Development Programme Rhodes University. Dept. of African Languages
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3580 , http://hdl.handle.net/10962/d1002155
- Full Text:
- Date Issued: 2010
Intertidal patterns and processes : tracking the effects of coastline topography and settlement choice across life stages of the mussels perna perna and mytilus galloprovincialis
- Von Der Meden, Charles Eric Otto
- Authors: Von Der Meden, Charles Eric Otto
- Date: 2010
- Subjects: Mexilhao mussel -- Behavior -- South Africa Mytilus galloprovincialis -- Behavior -- South Africa Perna -- Behavior -- South Africa Mussels -- Ecology -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5721 , http://hdl.handle.net/10962/d1005407
- Description: Within landscapes, spatial heterogeneity is common and specific landscape features can influence propagule dispersal by wind or water, affecting population connectivity and dynamics. Coastline topographic features, such as bays and headlands, have a variety of biophysical effects on nearshore oceanography, larval transport, retention and supply, and the processes of larval settlement and recruitment. Although this has been demonstrated in several parts of the world, engendering a perception of a general ‘bay effect’, few studies have investigated this generality in a single experiment or region, by replicating at the level of ‘bay’. The Agulhas biogeographic region of the south coast of South Africa is a useful system within which to test for such generality. Using the intertidal mussels Mytilus galloprovincialis and Perna perna as model organisms, patterns of adult distribution were surveyed across four large ‘halfheart’ bays and intervening stretches of open coast, providing replication at the level of ‘bay’ and duplication of ecologically similar species. In support of a general, pervasive influence of bays on intertidal populations, mussel cover was found to be greater in bays than on the open coast for both species, although the effect was strongest for M. galloprovincialis. To explain this adult distribution, settlement, post-settlement mortality and recruitment were examined over 12mo at the same sites, with the prediction that rates of each would favour larger bay populations. Contrary to this, an interaction between month and bay-status was found, with greater settlement and recruitment on the open coast than in bays reflecting extreme settlement and recruitment events at 3 westerly open coast sites during summer. Re-analysis excluding these outliers, revealed the expected effect, of greater settlement and recruitment in bays. While this indicates the broad generality of the bay effect, it highlights exceptions and the need for replication in time and space when examining landscape effects. Measuring post-settlement mortality required testing small-scale settlement behaviour on established and newly deployed settler collectors. It was found that all settlers preferred collectors with biofilm, but that primary settlers avoided conspecific settlers, while secondary settlers were attracted to them. With discrepancies in settler attraction to new and established collectors accounted for, initial (over 2d) and longer-term (over 7d) post-settlement mortality rates were found to be substantial (ca 60 %) for both species. No topographic effect on p-s mortality was evident. Finally, recruit-settler, adult-recruit and interspecies correlations were examined at regional and local scales. Synergistic (or neutral) effects maintained the initial settlement pattern in recruit and adult populations regionally, but not at local scales; striking interspecies correlations suggested the influence of common regional transport processes. Ultimately, the results emphasize the importance of the direction of effects in different life stages and at different spatial scales, and the possibility that antagonistic effects may mask even strong patterns.
- Full Text:
- Date Issued: 2010
- Authors: Von Der Meden, Charles Eric Otto
- Date: 2010
- Subjects: Mexilhao mussel -- Behavior -- South Africa Mytilus galloprovincialis -- Behavior -- South Africa Perna -- Behavior -- South Africa Mussels -- Ecology -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5721 , http://hdl.handle.net/10962/d1005407
- Description: Within landscapes, spatial heterogeneity is common and specific landscape features can influence propagule dispersal by wind or water, affecting population connectivity and dynamics. Coastline topographic features, such as bays and headlands, have a variety of biophysical effects on nearshore oceanography, larval transport, retention and supply, and the processes of larval settlement and recruitment. Although this has been demonstrated in several parts of the world, engendering a perception of a general ‘bay effect’, few studies have investigated this generality in a single experiment or region, by replicating at the level of ‘bay’. The Agulhas biogeographic region of the south coast of South Africa is a useful system within which to test for such generality. Using the intertidal mussels Mytilus galloprovincialis and Perna perna as model organisms, patterns of adult distribution were surveyed across four large ‘halfheart’ bays and intervening stretches of open coast, providing replication at the level of ‘bay’ and duplication of ecologically similar species. In support of a general, pervasive influence of bays on intertidal populations, mussel cover was found to be greater in bays than on the open coast for both species, although the effect was strongest for M. galloprovincialis. To explain this adult distribution, settlement, post-settlement mortality and recruitment were examined over 12mo at the same sites, with the prediction that rates of each would favour larger bay populations. Contrary to this, an interaction between month and bay-status was found, with greater settlement and recruitment on the open coast than in bays reflecting extreme settlement and recruitment events at 3 westerly open coast sites during summer. Re-analysis excluding these outliers, revealed the expected effect, of greater settlement and recruitment in bays. While this indicates the broad generality of the bay effect, it highlights exceptions and the need for replication in time and space when examining landscape effects. Measuring post-settlement mortality required testing small-scale settlement behaviour on established and newly deployed settler collectors. It was found that all settlers preferred collectors with biofilm, but that primary settlers avoided conspecific settlers, while secondary settlers were attracted to them. With discrepancies in settler attraction to new and established collectors accounted for, initial (over 2d) and longer-term (over 7d) post-settlement mortality rates were found to be substantial (ca 60 %) for both species. No topographic effect on p-s mortality was evident. Finally, recruit-settler, adult-recruit and interspecies correlations were examined at regional and local scales. Synergistic (or neutral) effects maintained the initial settlement pattern in recruit and adult populations regionally, but not at local scales; striking interspecies correlations suggested the influence of common regional transport processes. Ultimately, the results emphasize the importance of the direction of effects in different life stages and at different spatial scales, and the possibility that antagonistic effects may mask even strong patterns.
- Full Text:
- Date Issued: 2010
Investigating factors that negatively influence lean implementation in the Eastern Cape automotive industry
- Authors: Camagu, Sibo
- Date: 2010
- Subjects: Lean manufacturing -- South Africa -- Eastern Cape , Production management -- South Africa -- Eastern Cape , Industrial efficiency , Automobile industry and trade
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8655 , http://hdl.handle.net/10948/1360 , Lean manufacturing -- South Africa -- Eastern Cape , Production management -- South Africa -- Eastern Cape , Industrial efficiency , Automobile industry and trade
- Description: In this intensely competitive environment of the global economy, the survival of even the most established manufacturers depends on their ability to continuously improve quality whilst reducing costs. The resulting productivity of producing more with less is the only key to market leadership and sustainable competitive advantage. Changing production methods from mass-production to Lean Manufacturing has become the essential practise for successful manufacturers (Rogers and Sim, 2009). The purpose of this study is to investigate what factors negate the adoption and implementation of Lean Manufacturing as a means to gain competitive advantage. The focus was on companies that have participated in the AIDC Tirisano cluster programme. The study investigated what effect Organisational Culture, Leadership Behaviours, Employee Involvement and Strategy Integration have on Lean Manufacturing adoption and implementation. This study applied the mixed methodologies of qualitative and quantitative approaches using methodological triangulation. A cross sectional analytical survey approach in a descriptive case study was undertaken. The findings from the questions and the interviews from the respondents who participated in the survey indicated that the practices in some companies enable the successful adoption and implementation of Lean Manufacturing whilst in some others the practices will negatively affect the adoption and implementation. The study concludes by stating that South African automotive component manufacturers are under immense pressure to improve quality and reduce costs. Initiatives like Lean Manufacturing should be undertaken in order to bring about these improvements. But this improvement comes about by changing the current way of doing things. Companies need to undertake a total approach when implementing Lean as part of the business strategy and this must be driven by management as leaders and a team culture that involves all employees needs to be present.
- Full Text:
- Date Issued: 2010
- Authors: Camagu, Sibo
- Date: 2010
- Subjects: Lean manufacturing -- South Africa -- Eastern Cape , Production management -- South Africa -- Eastern Cape , Industrial efficiency , Automobile industry and trade
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8655 , http://hdl.handle.net/10948/1360 , Lean manufacturing -- South Africa -- Eastern Cape , Production management -- South Africa -- Eastern Cape , Industrial efficiency , Automobile industry and trade
- Description: In this intensely competitive environment of the global economy, the survival of even the most established manufacturers depends on their ability to continuously improve quality whilst reducing costs. The resulting productivity of producing more with less is the only key to market leadership and sustainable competitive advantage. Changing production methods from mass-production to Lean Manufacturing has become the essential practise for successful manufacturers (Rogers and Sim, 2009). The purpose of this study is to investigate what factors negate the adoption and implementation of Lean Manufacturing as a means to gain competitive advantage. The focus was on companies that have participated in the AIDC Tirisano cluster programme. The study investigated what effect Organisational Culture, Leadership Behaviours, Employee Involvement and Strategy Integration have on Lean Manufacturing adoption and implementation. This study applied the mixed methodologies of qualitative and quantitative approaches using methodological triangulation. A cross sectional analytical survey approach in a descriptive case study was undertaken. The findings from the questions and the interviews from the respondents who participated in the survey indicated that the practices in some companies enable the successful adoption and implementation of Lean Manufacturing whilst in some others the practices will negatively affect the adoption and implementation. The study concludes by stating that South African automotive component manufacturers are under immense pressure to improve quality and reduce costs. Initiatives like Lean Manufacturing should be undertaken in order to bring about these improvements. But this improvement comes about by changing the current way of doing things. Companies need to undertake a total approach when implementing Lean as part of the business strategy and this must be driven by management as leaders and a team culture that involves all employees needs to be present.
- Full Text:
- Date Issued: 2010
Motivation and complexity : an exploration of a complexity approach in employee motivation with specific focus on a Lacanian model of desire
- Authors: Botha, Anton Ivan
- Date: 2010
- Subjects: Employee motivation , Employee morale , Incentive awards
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:9400 , http://hdl.handle.net/10948/1232 , Employee motivation , Employee morale , Incentive awards
- Description: Since employee motivation contributes to overall organisational success, reliable motivation theory should inform management and reward practices. Yet, motivation theory is currently in a state of paralysis, with no constructive theorising taking place. Analysis of its methodological presuppositions reveals that it relies on out-dated binary thinking, prioritising, e.g. either a ‘machine-like’ (body driven) or ‘god-like’ (rationally driven) understanding of humanity. In this study it is argued that the revival of motivation theory requires a paradigmatic shift towards a complexity methodology because human motivation was found to be a complex system and must be theorised accordingly. It was found that McAdams’ theory of personality which brought together personality traits, conditioning, and motives could form the basis of a complex theory of motivation. On this basis, a complex model was developed which incorporated elements of existing motivational theories. This model proposed that drives, which motivate behaviour, are a combination of instincts, needs, and desires, mediated by personality traits, rational processing, and conditioning. All of these interconnected elements, as well as biological and environmental conditions, have an impact on, and are influenced by one another. For the purposes of understanding employee motivation the element of desire was isolated as a potential means to value segment employees. A Lacanian theory was utilised to elaborate on the element of desire. This theory postulated that individuals tend to display a dominance is one of nine kinds and modes of desire. An instrument was developed to test the applicability of the Lacanian model. It was developed in five phases which included three pilot studies and two samplings. A total of 591 respondents participated in the empirical research study with 428 in the first sample and 70 in the second; the remaining 93 made up the pilot studies. Unlike the initial version of the instrument used in the first sample (n=428) the data obtained by the last version (n=70) revealed that the instrument held some form of reliability and validity. Once analysed through descriptive and inferential statistics the data supported the view that individuals tended to display dominance in a kind and mode of desire as per the Lacanian model, and sufficient variance existed to preliminarily conclude that this model could be used as a means to value segment employees. Recommendations were as follows: (1) that complexity methodology should inform future motivation theorising, (2) that the proposed complexity models be further empirically tested, (3) that an adequately complex, flexible rewards system be considered, (4) that both managers and employees make use of the developed instrument to aid them in the selection of rewards that will lead to increased satisfaction.
- Full Text:
- Date Issued: 2010
- Authors: Botha, Anton Ivan
- Date: 2010
- Subjects: Employee motivation , Employee morale , Incentive awards
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:9400 , http://hdl.handle.net/10948/1232 , Employee motivation , Employee morale , Incentive awards
- Description: Since employee motivation contributes to overall organisational success, reliable motivation theory should inform management and reward practices. Yet, motivation theory is currently in a state of paralysis, with no constructive theorising taking place. Analysis of its methodological presuppositions reveals that it relies on out-dated binary thinking, prioritising, e.g. either a ‘machine-like’ (body driven) or ‘god-like’ (rationally driven) understanding of humanity. In this study it is argued that the revival of motivation theory requires a paradigmatic shift towards a complexity methodology because human motivation was found to be a complex system and must be theorised accordingly. It was found that McAdams’ theory of personality which brought together personality traits, conditioning, and motives could form the basis of a complex theory of motivation. On this basis, a complex model was developed which incorporated elements of existing motivational theories. This model proposed that drives, which motivate behaviour, are a combination of instincts, needs, and desires, mediated by personality traits, rational processing, and conditioning. All of these interconnected elements, as well as biological and environmental conditions, have an impact on, and are influenced by one another. For the purposes of understanding employee motivation the element of desire was isolated as a potential means to value segment employees. A Lacanian theory was utilised to elaborate on the element of desire. This theory postulated that individuals tend to display a dominance is one of nine kinds and modes of desire. An instrument was developed to test the applicability of the Lacanian model. It was developed in five phases which included three pilot studies and two samplings. A total of 591 respondents participated in the empirical research study with 428 in the first sample and 70 in the second; the remaining 93 made up the pilot studies. Unlike the initial version of the instrument used in the first sample (n=428) the data obtained by the last version (n=70) revealed that the instrument held some form of reliability and validity. Once analysed through descriptive and inferential statistics the data supported the view that individuals tended to display dominance in a kind and mode of desire as per the Lacanian model, and sufficient variance existed to preliminarily conclude that this model could be used as a means to value segment employees. Recommendations were as follows: (1) that complexity methodology should inform future motivation theorising, (2) that the proposed complexity models be further empirically tested, (3) that an adequately complex, flexible rewards system be considered, (4) that both managers and employees make use of the developed instrument to aid them in the selection of rewards that will lead to increased satisfaction.
- Full Text:
- Date Issued: 2010
The influence of talent management on strategy
- Authors: Piti, Mfundo
- Date: 2010
- Subjects: Personnel management , Ability , Organizational effectiveness , Employees -- Recruiting
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8623 , http://hdl.handle.net/10948/1501 , Personnel management , Ability , Organizational effectiveness , Employees -- Recruiting
- Description: Research indicates that effective talent management is essential in achieving organisational excellence and is a driving force for business success. This study focused on investigating VWSA Group Service division’s employee talent management process as seen or perceived by employees. The employee attitude and understanding of the 2010 strategy was also evaluated. In achieving this objective a literature review on talent management was conducted and questions formulated which formed part of the survey. The questionnaire was self-administered and sent to the stratified random sample of individuals who were eligible for survey. The main findings of this research are that the 2010 strategy was well received by the employees and that seventy seven percent of the respondents who took part in the study do understand the 2010 strategy and what it is all about. The study also highlighted that employees believe Project 1 in the 2010 strategy will be achieved. Employees were uncertain that compensation and leadership style are variables that influence or promote talent management. From the literature review it is explained that in order for talent management to be effective it must be aligned to organisational strategy. Various recommendations were made, for example conducting of skills gap analysis with a view to identify skills employees need to possess in order to meet the objectives of the 2010 strategy. Another recommendation was the formation of talent pools from which to recruit high talented staff and whose skills will be required to meet the objectives of the organisational strategy. A final point emanating from the study, is that when it comes to talent management and achieving organisational strategy it is not business as usual. Companies need to be aware of brand profiles most desired by highly talented individuals; they also need to be aware of various recruiting strategies as well as acknowledge that different employees are at different levels of the motivational hierarchy.
- Full Text:
- Date Issued: 2010
- Authors: Piti, Mfundo
- Date: 2010
- Subjects: Personnel management , Ability , Organizational effectiveness , Employees -- Recruiting
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8623 , http://hdl.handle.net/10948/1501 , Personnel management , Ability , Organizational effectiveness , Employees -- Recruiting
- Description: Research indicates that effective talent management is essential in achieving organisational excellence and is a driving force for business success. This study focused on investigating VWSA Group Service division’s employee talent management process as seen or perceived by employees. The employee attitude and understanding of the 2010 strategy was also evaluated. In achieving this objective a literature review on talent management was conducted and questions formulated which formed part of the survey. The questionnaire was self-administered and sent to the stratified random sample of individuals who were eligible for survey. The main findings of this research are that the 2010 strategy was well received by the employees and that seventy seven percent of the respondents who took part in the study do understand the 2010 strategy and what it is all about. The study also highlighted that employees believe Project 1 in the 2010 strategy will be achieved. Employees were uncertain that compensation and leadership style are variables that influence or promote talent management. From the literature review it is explained that in order for talent management to be effective it must be aligned to organisational strategy. Various recommendations were made, for example conducting of skills gap analysis with a view to identify skills employees need to possess in order to meet the objectives of the 2010 strategy. Another recommendation was the formation of talent pools from which to recruit high talented staff and whose skills will be required to meet the objectives of the organisational strategy. A final point emanating from the study, is that when it comes to talent management and achieving organisational strategy it is not business as usual. Companies need to be aware of brand profiles most desired by highly talented individuals; they also need to be aware of various recruiting strategies as well as acknowledge that different employees are at different levels of the motivational hierarchy.
- Full Text:
- Date Issued: 2010
An exploration of Zimbabwean migrant women's perceptions of their identity : selected case studies in Gqebera, Port Elizabeth, South Africa
- Authors: Moorhouse, Lesley
- Date: 2010
- Subjects: Women immigrants -- South Africa -- Port Elizabeth , Women -- Identity , Emigration and immigration -- South Africa -- Port Elizabeth , Immigrants -- South Africa -- Port Elizabeth , Gender identity -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:16140 , http://hdl.handle.net/10948/1200 , Women immigrants -- South Africa -- Port Elizabeth , Women -- Identity , Emigration and immigration -- South Africa -- Port Elizabeth , Immigrants -- South Africa -- Port Elizabeth , Gender identity -- South Africa -- Port Elizabeth
- Description: This study explores the perceptions of women who had migrated to Gqebera, Port Elizabeth, South Africa, from Zimbabwe, in terms of their own identity. In-depth interviews were conducted, situated within a phenomenological paradigm with a feminist epistemological orientation, in order to describe the rich detail of a woman’s quotidian existence subsequent to the migratory experience. Findings suggest that women’s identities are constructed in relation to other people, both those who form their in-group and their out-group. The process of migration and difficulties associated with assimilation into the host community impacts on felt ethnicity, strengthening ties to the homeland and to fellow Zimbabweans. Identity is also impacted on by spatiality, or lived space, in terms of both memories of home and present space occupied. Migration incorporating even the post-migration period may well form an extended liminal experience for women.
- Full Text:
- Date Issued: 2010
- Authors: Moorhouse, Lesley
- Date: 2010
- Subjects: Women immigrants -- South Africa -- Port Elizabeth , Women -- Identity , Emigration and immigration -- South Africa -- Port Elizabeth , Immigrants -- South Africa -- Port Elizabeth , Gender identity -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:16140 , http://hdl.handle.net/10948/1200 , Women immigrants -- South Africa -- Port Elizabeth , Women -- Identity , Emigration and immigration -- South Africa -- Port Elizabeth , Immigrants -- South Africa -- Port Elizabeth , Gender identity -- South Africa -- Port Elizabeth
- Description: This study explores the perceptions of women who had migrated to Gqebera, Port Elizabeth, South Africa, from Zimbabwe, in terms of their own identity. In-depth interviews were conducted, situated within a phenomenological paradigm with a feminist epistemological orientation, in order to describe the rich detail of a woman’s quotidian existence subsequent to the migratory experience. Findings suggest that women’s identities are constructed in relation to other people, both those who form their in-group and their out-group. The process of migration and difficulties associated with assimilation into the host community impacts on felt ethnicity, strengthening ties to the homeland and to fellow Zimbabweans. Identity is also impacted on by spatiality, or lived space, in terms of both memories of home and present space occupied. Migration incorporating even the post-migration period may well form an extended liminal experience for women.
- Full Text:
- Date Issued: 2010
A chemo-enzymatic process for the production of beta-thymidine, a key intermediate in antiretrovirol manufacture
- Gordon, Gregory Ernest Robert
- Authors: Gordon, Gregory Ernest Robert
- Date: 2010
- Subjects: HIV infections -- Treatment -- South Africa , HIV infections -- South Africa -- Prevention , Antiretroviral agents
- Language: English
- Type: Thesis , Doctoral , DTech
- Identifier: vital:10423 , http://hdl.handle.net/10948/d1016217
- Description: The socio-economic impact of HIV/AIDS on South Africa has resulted in lower gross domestic product, loss of skills in key sectors such as education, and increased health-care costs in providing access to treatment. Currently active pharmaceutical ingredients (API’s) such as stavudine (d4T) and azidothymidine (AZT) are imported from India and China, while formulation is conducted locally. A strategy was initiated between CSIR Biosciences and LIFElab under the auspices of Arvir Technologies to investigate the feasibility of local antiretroviral manufacture (d4T and AZT) or the manufacture of a key intermediate such as β- thymidine (dT). Several advantages associated with successful implementation of this strategy include ensuring a local supply of API’s, thus reducing reliance on procurement from foreign sources and reducing the effect of foreign exchange rate fluctuations on providing cost effective access to treatment. A local supply source would also reduce the imports and thus aid the balance of payments deficit, and in addition to this, provide stimulus in the local pharmaceutical manufacturing industry (which has been in decline for several decades), resulting in increased skills and employment opportunities. This thesis describes the development of a superior chemo-enzymatic process for the production of β-thymidine (72 percent yield, prior to isolation), a key intermediate in the preparation of anti-retrovirals. Alternative processes based purely on chemical or bioprocess transformations to prepare either 5-methyluridine (5-MU) or dT suffer from several disadvantages: lengthy transformations due to protection/deprotection strategies, low selectivties and product yields (30 percent in the chemical process) and isolation of the product from dilute process streams requiring the use of large uneconomical reactors (bioprocesss). This contributes significantly to the cost of d4T and AZT manufacture. Our novel chemoenzymatic process comprises of a biocatalytic reaction for the production of 5-MU, with subsequent chemical transformation into dT (3 steps) negating and circumventing the limitations of the chemical or bioprocess routes. During the course of this project development, the β-thymidine selling price declined from 175 $/kg (2005) to 100 $/kg (2008). However, the process described in this work is still competitive based on the current β- thymidine selling price of 100 $/kg. The process economics show that with further optimization and increasing the isolated dT yield from 70 percent to 90 percent, the variable cost decreases from 136 $/kg to 110 $/kg. The increase in isolated yield is highly probable, based on solubility data of β-thymidine. The decrease in β-thymidine selling price and technological improvement in dT manufacture should translate into lower API manufacture costs and more cost effective access to treatment. Our novel biocatalytic process producing 5-MU uses a coupled enzyme system employing PNP, Purine Nucleoside Phosphorylase and PyNP, Pyrimidine Nucleoside Phosphorylase. The overall transglycosylation reaction may be decoupled into the phosphorolysis reaction (PNP) and synthesis reaction (PyNP). During the phosphorolysis reaction, guanosine is converted into guanine and ribose-1-phosphate (R-1-P) in the presence of PNP enzyme. The reaction intermediate R-1-P is then coupled to thymine in the presence of PyNP enzyme during the synthesis reaction, producing 5-MU. The process was scaled up from lab-scale to bench-scale (10 - 20 L) and demonstrated to be robust and reproducible. This is evident from the average guanosine conversion (94.7 percent ± 2.03) and 5-MU yield (88.2 percent ± 6.21) and mole balance (104 percent ± 7.61) which were obtained at bench-scale (3 replicates, 10 L). The reaction was carried out at reactor productivities of between 7 – 11 g.L-1.h-1. The integration of the biocatalytic process and chemical processes was successfully carried out, showing that 5-MU produced using our novel biocatalytic process behaved similarly to commercially available 5- MU (ex. Dayang Chemicals, China). A PCT patent application (Ref. No. P44422PC01) on this chemo-enzymatic process has been filed and currently public private partnerships are being explored through Arvir Technologies to evaluate and validate this technology at one ton scale.
- Full Text:
- Date Issued: 2010
- Authors: Gordon, Gregory Ernest Robert
- Date: 2010
- Subjects: HIV infections -- Treatment -- South Africa , HIV infections -- South Africa -- Prevention , Antiretroviral agents
- Language: English
- Type: Thesis , Doctoral , DTech
- Identifier: vital:10423 , http://hdl.handle.net/10948/d1016217
- Description: The socio-economic impact of HIV/AIDS on South Africa has resulted in lower gross domestic product, loss of skills in key sectors such as education, and increased health-care costs in providing access to treatment. Currently active pharmaceutical ingredients (API’s) such as stavudine (d4T) and azidothymidine (AZT) are imported from India and China, while formulation is conducted locally. A strategy was initiated between CSIR Biosciences and LIFElab under the auspices of Arvir Technologies to investigate the feasibility of local antiretroviral manufacture (d4T and AZT) or the manufacture of a key intermediate such as β- thymidine (dT). Several advantages associated with successful implementation of this strategy include ensuring a local supply of API’s, thus reducing reliance on procurement from foreign sources and reducing the effect of foreign exchange rate fluctuations on providing cost effective access to treatment. A local supply source would also reduce the imports and thus aid the balance of payments deficit, and in addition to this, provide stimulus in the local pharmaceutical manufacturing industry (which has been in decline for several decades), resulting in increased skills and employment opportunities. This thesis describes the development of a superior chemo-enzymatic process for the production of β-thymidine (72 percent yield, prior to isolation), a key intermediate in the preparation of anti-retrovirals. Alternative processes based purely on chemical or bioprocess transformations to prepare either 5-methyluridine (5-MU) or dT suffer from several disadvantages: lengthy transformations due to protection/deprotection strategies, low selectivties and product yields (30 percent in the chemical process) and isolation of the product from dilute process streams requiring the use of large uneconomical reactors (bioprocesss). This contributes significantly to the cost of d4T and AZT manufacture. Our novel chemoenzymatic process comprises of a biocatalytic reaction for the production of 5-MU, with subsequent chemical transformation into dT (3 steps) negating and circumventing the limitations of the chemical or bioprocess routes. During the course of this project development, the β-thymidine selling price declined from 175 $/kg (2005) to 100 $/kg (2008). However, the process described in this work is still competitive based on the current β- thymidine selling price of 100 $/kg. The process economics show that with further optimization and increasing the isolated dT yield from 70 percent to 90 percent, the variable cost decreases from 136 $/kg to 110 $/kg. The increase in isolated yield is highly probable, based on solubility data of β-thymidine. The decrease in β-thymidine selling price and technological improvement in dT manufacture should translate into lower API manufacture costs and more cost effective access to treatment. Our novel biocatalytic process producing 5-MU uses a coupled enzyme system employing PNP, Purine Nucleoside Phosphorylase and PyNP, Pyrimidine Nucleoside Phosphorylase. The overall transglycosylation reaction may be decoupled into the phosphorolysis reaction (PNP) and synthesis reaction (PyNP). During the phosphorolysis reaction, guanosine is converted into guanine and ribose-1-phosphate (R-1-P) in the presence of PNP enzyme. The reaction intermediate R-1-P is then coupled to thymine in the presence of PyNP enzyme during the synthesis reaction, producing 5-MU. The process was scaled up from lab-scale to bench-scale (10 - 20 L) and demonstrated to be robust and reproducible. This is evident from the average guanosine conversion (94.7 percent ± 2.03) and 5-MU yield (88.2 percent ± 6.21) and mole balance (104 percent ± 7.61) which were obtained at bench-scale (3 replicates, 10 L). The reaction was carried out at reactor productivities of between 7 – 11 g.L-1.h-1. The integration of the biocatalytic process and chemical processes was successfully carried out, showing that 5-MU produced using our novel biocatalytic process behaved similarly to commercially available 5- MU (ex. Dayang Chemicals, China). A PCT patent application (Ref. No. P44422PC01) on this chemo-enzymatic process has been filed and currently public private partnerships are being explored through Arvir Technologies to evaluate and validate this technology at one ton scale.
- Full Text:
- Date Issued: 2010
Mediating factors in the relationship between childhood sexual abuse and HIV Sexual risk behaviour among men who have sex with men
- Authors: Heusser, Shelly Lucien
- Date: 2010
- Subjects: Adult child sexual abuse victims -- Sexual behavior -- South Africa , Sexually transmitted diseases -- Psychological aspects , Risk-taking (Psychology)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9873 , http://hdl.handle.net/10948/1398 , Adult child sexual abuse victims -- Sexual behavior -- South Africa , Sexually transmitted diseases -- Psychological aspects , Risk-taking (Psychology)
- Description: Previous studies have indicated an association between childhood sexual abuse (CSA) and an increased risk of engaging in unsafe behaviours during adulthood, including risky sexual practices. This study examined the relationship between CSA and adult HIV sexual risk behaviour among a sample of South African men who have sex with men (MSM). Potential pathological long-term mental health outcomes of CSA, including dissociation, sex-related substance abuse, depression, sexual compulsivity, impaired interpersonal communication, and over-reliance on submissive sexual scripts, were treated as variables mediating the relationship between CSA and sexual risk behaviour. Men frequenting a gay internet dating site were randomly selected to complete an electronic version of the anonymous survey. Results indicate that one-fourth of participants reported a history of CSA. Men with a history of unwanted sexual activity during childhood were more likely to report recreational substance abuse, sex-related substance abuse, sexual compulsivity, and adult revictimisation experiences. Men who were abused were also more likely to engage in unprotected anal intercourse compared to those who were not abused. Mediation analyses revealed that MSM who are survivors of CSA are particularly susceptible to drug abuse, sex-related drug abuse, and sexual compulsivity, and these sequelae in turn predict higher reported numbers of male sexual partners. The current data suggest that CSA is widespread among men at high risk for HIV infection, and that it may have a devastating influence on the quality of life and health risk behaviour of these men. These results also highlight the importance of mental health services and new approaches in HIV prevention for MSM who have been sexually abused as children. Further research is needed into the contextual factors of the childhood abuse experience which account for the variability in longterm negative mental health outcomes of CSA survivors.
- Full Text:
- Date Issued: 2010
- Authors: Heusser, Shelly Lucien
- Date: 2010
- Subjects: Adult child sexual abuse victims -- Sexual behavior -- South Africa , Sexually transmitted diseases -- Psychological aspects , Risk-taking (Psychology)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9873 , http://hdl.handle.net/10948/1398 , Adult child sexual abuse victims -- Sexual behavior -- South Africa , Sexually transmitted diseases -- Psychological aspects , Risk-taking (Psychology)
- Description: Previous studies have indicated an association between childhood sexual abuse (CSA) and an increased risk of engaging in unsafe behaviours during adulthood, including risky sexual practices. This study examined the relationship between CSA and adult HIV sexual risk behaviour among a sample of South African men who have sex with men (MSM). Potential pathological long-term mental health outcomes of CSA, including dissociation, sex-related substance abuse, depression, sexual compulsivity, impaired interpersonal communication, and over-reliance on submissive sexual scripts, were treated as variables mediating the relationship between CSA and sexual risk behaviour. Men frequenting a gay internet dating site were randomly selected to complete an electronic version of the anonymous survey. Results indicate that one-fourth of participants reported a history of CSA. Men with a history of unwanted sexual activity during childhood were more likely to report recreational substance abuse, sex-related substance abuse, sexual compulsivity, and adult revictimisation experiences. Men who were abused were also more likely to engage in unprotected anal intercourse compared to those who were not abused. Mediation analyses revealed that MSM who are survivors of CSA are particularly susceptible to drug abuse, sex-related drug abuse, and sexual compulsivity, and these sequelae in turn predict higher reported numbers of male sexual partners. The current data suggest that CSA is widespread among men at high risk for HIV infection, and that it may have a devastating influence on the quality of life and health risk behaviour of these men. These results also highlight the importance of mental health services and new approaches in HIV prevention for MSM who have been sexually abused as children. Further research is needed into the contextual factors of the childhood abuse experience which account for the variability in longterm negative mental health outcomes of CSA survivors.
- Full Text:
- Date Issued: 2010
Social sustainability of biogas production in Sogwala village, lower Gweru district, Zimbabwe
- Authors: Dhliwayo, Nyaradzo
- Date: 2010
- Subjects: Biogas -- Zimbabwe , Biogas -- Developing countries , Sustainability -- Zimbabwe
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10648 , http://hdl.handle.net/10948/1459 , Biogas -- Zimbabwe , Biogas -- Developing countries , Sustainability -- Zimbabwe
- Description: The study has explored the social sustainability of biogas production in a local village of Sogwala which is located in the Lower Gweru District of Zimbabwe. The social sustainability assessment was based on the two concepts of social sustainability, namely human capital and social capital with particular emphasis on their respective elements and aspects. Qualitative and quantitative research methodology methods were used on a sample of 100 households using biogas and some key informants. Analysis of the variance was used to determine whether biogas production could account for any effects on the social and human capital elements of the Sogwala community. An overview and descriptive statistics analysis of the findings from the study have been provided where the biogas users’ experiences, perspectives are discussed and results were assessed. For instance, effects on the aspects of social capital elements which include increases in the social group membership of households after the introduction of biogas production the village; the performance of biogas energy as compared with other fuel sources in terms of accessibility, efficiency and the degree of labour needed for continual production of biogas. In view of the human capital element, assessment is done on the economic status per household before and after the production of biogas, where emphasis is placed on the aspects of employment, education and health indicators within the social sustainability context. The fundamental benefits from biogas production are considered and discussed with the technical issues surrounding biogas production also being presented. This is not just a technical unit for providing alternative energy supply, but it requires management, labour and knowledge, skills to operate on a daily basis for it to have an impact that can bring positive change to the daily social lives of both the young and old.
- Full Text:
- Date Issued: 2010
- Authors: Dhliwayo, Nyaradzo
- Date: 2010
- Subjects: Biogas -- Zimbabwe , Biogas -- Developing countries , Sustainability -- Zimbabwe
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10648 , http://hdl.handle.net/10948/1459 , Biogas -- Zimbabwe , Biogas -- Developing countries , Sustainability -- Zimbabwe
- Description: The study has explored the social sustainability of biogas production in a local village of Sogwala which is located in the Lower Gweru District of Zimbabwe. The social sustainability assessment was based on the two concepts of social sustainability, namely human capital and social capital with particular emphasis on their respective elements and aspects. Qualitative and quantitative research methodology methods were used on a sample of 100 households using biogas and some key informants. Analysis of the variance was used to determine whether biogas production could account for any effects on the social and human capital elements of the Sogwala community. An overview and descriptive statistics analysis of the findings from the study have been provided where the biogas users’ experiences, perspectives are discussed and results were assessed. For instance, effects on the aspects of social capital elements which include increases in the social group membership of households after the introduction of biogas production the village; the performance of biogas energy as compared with other fuel sources in terms of accessibility, efficiency and the degree of labour needed for continual production of biogas. In view of the human capital element, assessment is done on the economic status per household before and after the production of biogas, where emphasis is placed on the aspects of employment, education and health indicators within the social sustainability context. The fundamental benefits from biogas production are considered and discussed with the technical issues surrounding biogas production also being presented. This is not just a technical unit for providing alternative energy supply, but it requires management, labour and knowledge, skills to operate on a daily basis for it to have an impact that can bring positive change to the daily social lives of both the young and old.
- Full Text:
- Date Issued: 2010
Handspring Puppet Company, Jane Taylor (Ed.)
- Authors: Krueger, Anton
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229658 , vital:49697 , xlink:href="https://0hdl.handle.net.wam.seals.ac.za/10520/EJC31088"
- Description: Handspring Puppet Company recently won three prestigious London awards (including the Olivier) for their design of the production War Horse, which is still running to great acclaim in the West End. This beautiful book has been released at exactly the right time, at a highpoint of an extraordinary company which has been producing astonishing work for 28 years already. It is an appropriate celebration of their many marvellous designs for 11 plays and two operas.
- Full Text:
- Date Issued: 2010
- Authors: Krueger, Anton
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229658 , vital:49697 , xlink:href="https://0hdl.handle.net.wam.seals.ac.za/10520/EJC31088"
- Description: Handspring Puppet Company recently won three prestigious London awards (including the Olivier) for their design of the production War Horse, which is still running to great acclaim in the West End. This beautiful book has been released at exactly the right time, at a highpoint of an extraordinary company which has been producing astonishing work for 28 years already. It is an appropriate celebration of their many marvellous designs for 11 plays and two operas.
- Full Text:
- Date Issued: 2010
The role of strategic leadership in Coega Development Corporation: a case study
- Authors: Davids, Mogamad Sadiek
- Date: 2010
- Subjects: Coega Development Corporation Industrial development projects -- South Africa -- Eastern Cape -- Case studies Leadership -- South Africa -- Eastern Cape -- Case studies Strategic planning -- South Africa -- Eastern Cape -- Case studies Organizational behavior -- South Africa -- Eastern Cape -- Case studies
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:763 , http://hdl.handle.net/10962/d1003884
- Description: South Africa became a democracy after its election in April 1994. Thereafter, the country faced the daunting task of trying to fast-track economic growth and addressing social challenges. The Department of Trade and Industry was mandated by the newly elected government to spearhead economic development in order to address these challenges. Trade policy instruments such as industrial development zones formed part of government’s strategic economic instruments to achieve economic reform. The Coega Industrial Development Zone (CIDZ) near Port Elizabeth was one of many economic development zones created principally to promote export orientated manufacturing. The Coega Development Corporation (CDC) was registered as a company to develop, operate and manage the CIDZ. The literature suggests that strategic leadership is important for organizational success. Strategic leadership is described as the ability to influence others to make day-to-day voluntary decisions that enhance long-term viability while maintaining short term financial stability. Literature further suggests that strategic leaders deal with the evolution of organizations and their changing aims and transform them through their capabilities and strategic leadership roles such as being a figurehead, spokesperson, team builder, design school planner and so on. The aim of this research is to analyse the role of strategic leadership with the objectives to ascertain whether strategic leadership contributed to the success of the development of CDC, and identify possible challenges they are confronted with in the execution of their leadership duties. This research was conducted from an interpretivist perspective as the researcher attempted to develop insight into how the strategic leadership of CDC viewed and understood their role. The strategic leadership of CDC, who were the focus of this study, consisted of the executive management team of the organization, including the Chief Executive Officer (CEO). The research design was in the form of a case study of the CDC leadership, with data collected through semi-structured interviews and documents. The most prominent roles exercised by the leadership of CDC included creating a vision and strategy development and inculcating a teamwork corporate culture. Other roles identified include that of team builder, fostering innovation and developing human capital etc. A lack of stakeholder management as well as managing the culture of the organization as it expands and grows, remain critical challenges. Finally recommendations are made together with suggestions for future research.
- Full Text:
- Date Issued: 2010
- Authors: Davids, Mogamad Sadiek
- Date: 2010
- Subjects: Coega Development Corporation Industrial development projects -- South Africa -- Eastern Cape -- Case studies Leadership -- South Africa -- Eastern Cape -- Case studies Strategic planning -- South Africa -- Eastern Cape -- Case studies Organizational behavior -- South Africa -- Eastern Cape -- Case studies
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:763 , http://hdl.handle.net/10962/d1003884
- Description: South Africa became a democracy after its election in April 1994. Thereafter, the country faced the daunting task of trying to fast-track economic growth and addressing social challenges. The Department of Trade and Industry was mandated by the newly elected government to spearhead economic development in order to address these challenges. Trade policy instruments such as industrial development zones formed part of government’s strategic economic instruments to achieve economic reform. The Coega Industrial Development Zone (CIDZ) near Port Elizabeth was one of many economic development zones created principally to promote export orientated manufacturing. The Coega Development Corporation (CDC) was registered as a company to develop, operate and manage the CIDZ. The literature suggests that strategic leadership is important for organizational success. Strategic leadership is described as the ability to influence others to make day-to-day voluntary decisions that enhance long-term viability while maintaining short term financial stability. Literature further suggests that strategic leaders deal with the evolution of organizations and their changing aims and transform them through their capabilities and strategic leadership roles such as being a figurehead, spokesperson, team builder, design school planner and so on. The aim of this research is to analyse the role of strategic leadership with the objectives to ascertain whether strategic leadership contributed to the success of the development of CDC, and identify possible challenges they are confronted with in the execution of their leadership duties. This research was conducted from an interpretivist perspective as the researcher attempted to develop insight into how the strategic leadership of CDC viewed and understood their role. The strategic leadership of CDC, who were the focus of this study, consisted of the executive management team of the organization, including the Chief Executive Officer (CEO). The research design was in the form of a case study of the CDC leadership, with data collected through semi-structured interviews and documents. The most prominent roles exercised by the leadership of CDC included creating a vision and strategy development and inculcating a teamwork corporate culture. Other roles identified include that of team builder, fostering innovation and developing human capital etc. A lack of stakeholder management as well as managing the culture of the organization as it expands and grows, remain critical challenges. Finally recommendations are made together with suggestions for future research.
- Full Text:
- Date Issued: 2010
The ambivalence of African elitehood:
- Authors: Matthews, Sally
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142442 , vital:38080 , DOI: 10.1177/0021909609357416
- Description: Recent discussions in South Africa about the role of the so-called patriotic bourgeoisie highlight the much debated question of what role elite Africans can and ought to play in the upliftment of the poor. Those supporting the notion of a patriotic bourgeoisie believe that national or racial solidarity is sufficient to allow privileged Africans to act in the interests of their poorer fellow citizens. However, a reconsideration of an older discussion of African elitehood, that of Amilcar Cabral, suggests that something more may be needed before elites can act in the interests of the poor. Cabral argues that elites need to renounce their privilege and to live and struggle alongside the poor if pro-poor societal transformation is to be achieved. While Cabral may be right that shared racial or national identity is insufficient for elite solidarity with the poor, he does not consider all the complexities that arise when elites actually try to work with and for the poor. A consideration of the experiences of a long-standing Senegalese NGO reveal some of these complexities and suggest that any attempt by African elites to engage meaningfully in the upliftment of the poor, will inevitably involve continuous and difficult negotiation between paternalism and naïve egalitarianism.
- Full Text:
- Date Issued: 2010
- Authors: Matthews, Sally
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142442 , vital:38080 , DOI: 10.1177/0021909609357416
- Description: Recent discussions in South Africa about the role of the so-called patriotic bourgeoisie highlight the much debated question of what role elite Africans can and ought to play in the upliftment of the poor. Those supporting the notion of a patriotic bourgeoisie believe that national or racial solidarity is sufficient to allow privileged Africans to act in the interests of their poorer fellow citizens. However, a reconsideration of an older discussion of African elitehood, that of Amilcar Cabral, suggests that something more may be needed before elites can act in the interests of the poor. Cabral argues that elites need to renounce their privilege and to live and struggle alongside the poor if pro-poor societal transformation is to be achieved. While Cabral may be right that shared racial or national identity is insufficient for elite solidarity with the poor, he does not consider all the complexities that arise when elites actually try to work with and for the poor. A consideration of the experiences of a long-standing Senegalese NGO reveal some of these complexities and suggest that any attempt by African elites to engage meaningfully in the upliftment of the poor, will inevitably involve continuous and difficult negotiation between paternalism and naïve egalitarianism.
- Full Text:
- Date Issued: 2010
Application of the sustainable livelihoods framework to the analysis of the Provincial Growth and Development Plan of the Eastern Cape: a case study of the Massive Food Production Programme in Nkonkobe Municipality and Buffalo City Municipality
- Authors: Dirwayi, Tafadzwa P
- Date: 2010
- Subjects: Sustainable agriculture -- South Africa -- Eastern Cape , Sustainable development -- South Africa -- Eastern Cape , Poverty -- South Africa -- Eastern Cape , Rural poor -- South Africa -- Eastern Cape , Food supply -- South Africa -- Eastern Cape , Food security -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Agricultural Economics)
- Identifier: vital:11159 , http://hdl.handle.net/10353/353 , Sustainable agriculture -- South Africa -- Eastern Cape , Sustainable development -- South Africa -- Eastern Cape , Poverty -- South Africa -- Eastern Cape , Rural poor -- South Africa -- Eastern Cape , Food supply -- South Africa -- Eastern Cape , Food security -- South Africa -- Eastern Cape
- Description: The Government of the Eastern Cape Province introduced the Massive Food Production programme, which is a cornerstone within the agrarian reform initiative of the Provincial Growth and Development Plan (PGDP). The programme has been going on for more than seven years, however little has been documented on its impact. The main objective of the study was to investigate the impact of the Massive Food Production Programme on the livelihoods in Nkonkobe Municipality. This study did not only investigate its impact on the participants but also assessed its impact on the recipient communities. Accordingly, the specific objectives of the study were to investigate the impact of the Massive Food Programme on the asset base of participants, the general livelihood activities, and the livelihood outcomes. Among other livelihood activities, the study made an in-depth investigation on the impact of the Massive Food Production Programme on maize crop production. This is because the Massive Food Production was aimed at maize crop production. Previous studies investigated on the indicators of success that can be used to measure the impact of this programme. After the wide-ranging evaluation of views, arguments and research findings, a model to measure impact of the programme was designed. The asset base improvement was used as the proxy of impact. Nine factors were selected from the principal component analysis of the many factors that were taken to affect participation. Three other dummy variables to proximate location, participation and group turnover were added to the regression model that was developed to measure impact. The DFID Sustainable Livelihood Framework was used to investigate the impact of the Massive Food Production Programme. This approach was used in both conceptualizing the study and the selection of variables. The DFID Sustainable Livelihood Approach was selected because unlike the CARE or UNDP Sustainable Livelihood models, it was designed for such purposes. Data collection was accomplished through observation, interviewing, and focus group discussions. The researcher also made use of project annual reports on change of livelihoods, baseline survey reports, project log frame, internal reports, work plans, budgets and mid-term evaluation reports as sources of secondary data. v The research findings were analysed using several analytical procedures, including the conventional descriptive statistics, principal components analysis, and linear regression analysis. The use of the different types of analysis was driven by the research questions under investigation and the theories on which they are based, and by the available data. The study revealed that to some extent the Massive Food Production Programme has managed to improve the asset base of the farmers. However, its impact on ensuring food security is still debatable. Findings of the study revealed that most of the participants and the non-participants communities experienced food shortages in the last season 2007/8 for at most three months. The study revealed that the highest agricultural income is from livestock sales. The varying locations showed the potential of livestock production. It is recommended that development agencies consider livestock production as an agricultural strategy with immense potential for enhancing sustaining rural livelihoods
- Full Text:
- Date Issued: 2010
- Authors: Dirwayi, Tafadzwa P
- Date: 2010
- Subjects: Sustainable agriculture -- South Africa -- Eastern Cape , Sustainable development -- South Africa -- Eastern Cape , Poverty -- South Africa -- Eastern Cape , Rural poor -- South Africa -- Eastern Cape , Food supply -- South Africa -- Eastern Cape , Food security -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Agricultural Economics)
- Identifier: vital:11159 , http://hdl.handle.net/10353/353 , Sustainable agriculture -- South Africa -- Eastern Cape , Sustainable development -- South Africa -- Eastern Cape , Poverty -- South Africa -- Eastern Cape , Rural poor -- South Africa -- Eastern Cape , Food supply -- South Africa -- Eastern Cape , Food security -- South Africa -- Eastern Cape
- Description: The Government of the Eastern Cape Province introduced the Massive Food Production programme, which is a cornerstone within the agrarian reform initiative of the Provincial Growth and Development Plan (PGDP). The programme has been going on for more than seven years, however little has been documented on its impact. The main objective of the study was to investigate the impact of the Massive Food Production Programme on the livelihoods in Nkonkobe Municipality. This study did not only investigate its impact on the participants but also assessed its impact on the recipient communities. Accordingly, the specific objectives of the study were to investigate the impact of the Massive Food Programme on the asset base of participants, the general livelihood activities, and the livelihood outcomes. Among other livelihood activities, the study made an in-depth investigation on the impact of the Massive Food Production Programme on maize crop production. This is because the Massive Food Production was aimed at maize crop production. Previous studies investigated on the indicators of success that can be used to measure the impact of this programme. After the wide-ranging evaluation of views, arguments and research findings, a model to measure impact of the programme was designed. The asset base improvement was used as the proxy of impact. Nine factors were selected from the principal component analysis of the many factors that were taken to affect participation. Three other dummy variables to proximate location, participation and group turnover were added to the regression model that was developed to measure impact. The DFID Sustainable Livelihood Framework was used to investigate the impact of the Massive Food Production Programme. This approach was used in both conceptualizing the study and the selection of variables. The DFID Sustainable Livelihood Approach was selected because unlike the CARE or UNDP Sustainable Livelihood models, it was designed for such purposes. Data collection was accomplished through observation, interviewing, and focus group discussions. The researcher also made use of project annual reports on change of livelihoods, baseline survey reports, project log frame, internal reports, work plans, budgets and mid-term evaluation reports as sources of secondary data. v The research findings were analysed using several analytical procedures, including the conventional descriptive statistics, principal components analysis, and linear regression analysis. The use of the different types of analysis was driven by the research questions under investigation and the theories on which they are based, and by the available data. The study revealed that to some extent the Massive Food Production Programme has managed to improve the asset base of the farmers. However, its impact on ensuring food security is still debatable. Findings of the study revealed that most of the participants and the non-participants communities experienced food shortages in the last season 2007/8 for at most three months. The study revealed that the highest agricultural income is from livestock sales. The varying locations showed the potential of livestock production. It is recommended that development agencies consider livestock production as an agricultural strategy with immense potential for enhancing sustaining rural livelihoods
- Full Text:
- Date Issued: 2010
Ecology and degree of specialization of South African milkweeds with diverse pollination systems
- Authors: Coombs, Gareth
- Date: 2010
- Subjects: Milkweeds -- South Africa Milkweeds -- South Africa -- Ecology Milkweeds -- South Africa -- Pollination Allee effect Self-pollination Pollination by insects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4189 , http://hdl.handle.net/10962/d1003758
- Description: Like orchids, the complexity of flowers found in asclepiads (Asclepiadoideae, Apocynaceae) and the fact that pollen is presented as pollinaria, offers excellent opportunities to study various aspects of plant-pollinator interactions. In this thesis I investigated two broad themes: ecological aspects of the pollination biology of hymenopteran and fly-pollinated asclepiads as well as the degree of specialization to certain pollinators in these species. Colonizing plants often reproduce through self-pollination, or have highly generalized pollination systems, or both. These characteristics facilitate establishment in small founding populations and generates the prediction that reproductive success should be independent of population size in these species. Chapter one examines the pollination biology of Gomphocarpus physocarpus, an indigenous, weedy species and investigates the relationship between reproductive success and population size. In this species, there is no evidence of an Allee effect and reproductive success is not correlated with population size. In addition G. physocarpus is not capable of self-pollination, suggesting it is completely reliant on pollinators for seed set. The lack of a relationship between pollination success and population size is therefore likely explained by the generalized wasp pollination system of this species. Several milkweeds are invasive outside of their native ranges. Invasive species either need to co-opt native pollinators in order to reproduce or reduce their reliance on pollinators through having the ability to self-pollinate. Co-opting native pollinators is expected to be easier in species that have generalized pollination systems, alternatively species with specialized flower morphologies need to rely on similar functional groups of pollinators to be present within the invaded range. Chapter two investigates the pollination biology and pollination success of the invasive milkweed, Araujia sericifera, and finds that in South Africa, this species is visited mainly by native honeybees and nocturnal moths. Moths however contribute little to pollen removal, and deposition. Based on the apparent morphological mismatch between the flower of A. sericifera and native honeybees, I propose that the native pollinators of this species are likely to be larger Hymenoptera (e.g. Bumblebees). Data from a breeding system study, indicated that this species is not capable of automatic self-pollination, but could set fruit from geitonogamous self-pollinations pointing to the importance of native pollinators for successful reproduction. The pollinaria of milkweeds can accumulate on pollinators to form pollen masses large enough to physically interfere with the foraging behaviour of pollinating insects. In chapter three I describe the pollination biology of Cynanchum ellipticum and find that this species is mainly pollinated by honeybees although this species is visited by several other members of Hymenoptera, Lepidoptera and Diptera. Due to the structure of the pollinaria, these chain together relatively efficiently and frequently form large pollinarium loads on the mouthparts of honeybees. However there is little evidence that these pollinarium loads influence the foraging times of pollinators and only a few individual honeybees exhibited longer foraging times and most honeybees were unaffected by the presence of large pollinarium loads. Within the genus Cynanchum there is large variation in the gynostegium structure that may influence the pattern of pollinarium loading on pollinators as well as pollen reception as shown in chapter three. In Chapter four, the pollination biology of Cynanchum obtusifolium is examined, and like that of C. ellipticum, this species is visited by a wide diversity of pollinators but honeybees appear to be the primary pollinators. More importantly this species is shown to be andromonoecious and produces two morphologically different flower types, that may be distinguished based on differences in the gynostegium structure. These two types of flower could mainly be distinguished by the length of the anther wings. I found that flowers with short anther wings function as male flowers by only exporting- and rarely receiving pollinia. Flowers with longer anther wings function as hermaphrodite flowers and can both export and receive pollinia. The ratio of male to hermaphrodite flowers varied at different times during the flowering season, but preliminary data suggested that this was not related to levels of pollination success. The genera Stapelia and Ceropegia are well known for their intricate floral adaptations that mimic the brood and feeding substrates of pollinating flies. Despite several studies that have documented the various adaptations to fly pollination in different species, there is a lack of natural history studies documenting different flower visitors, pollen loads and long term levels of pollination success in these species. In Chapter six I document the pollination biology of Ceropegia ampliata by documenting different pollinators and quantifying average levels of pollination success and the nectar reward. I also experimentally manipulated the trapping hairs of this species to determine whether trapping hairs influence average levels of pollen export and receipt. I show that Ceropegia ampliata is pollinated by a generalist guild of flies (mainly Tachinidae, Sarcophagidae, Muscidae and Lauxaniidae) and produces minute quantities of relatively dilute nectar as a reward. Pollination success was generally low in this species and increases periodically suggesting that the abundance of pollinators is patchy. I found that flowers with trapping hairs that had already wilted had higher levels of pollinarium removal than flowers with erect hairs, however experimentally removing the hairs had no significant effect on pollen export and receipt. In Chapter seven, I document the pollinators, pollen loads and long term levels of pollination success in Stapelia hirsuta var. bayllissi, a rare sapromyiophilous stapeliad. I find that, in contrast to C. ampliata, this species was specialized to pollination by small flies of the family Anthomyiidae. Similar to the results from Chapter seven, I find that long term levels of pollination success were typically low but could increase periodically, although such increases were generally unpredictable. There are currently very few records documenting pollinator interactions in the Periplocoideae. Many species within this subfamily exhibit open-access flowers suggestive of pollination by short-tongued insects. I investigated the pollination biology of Chlorocyathus lobulata, a rare species with a highly localized distribution. I aimed to determine the pollinators, average levels of pollination success and demography of this species in order to determine whether this rare species is suffering from the collapse of a highly specialized pollinator mutualism. I also quantified the high incidence of flower herbivory caused by larvae of the moth, Bocchoris onychinalis. I find that C. lobulata has a highly generalized fly pollination system and average levels of pollination success suggested that a large proportion of flowers had pollen removed and deposited suggesting that this species is not experiencing pollination failure. The large numbers of juveniles present also indicated that recruitment is taking place.
- Full Text:
- Date Issued: 2010
- Authors: Coombs, Gareth
- Date: 2010
- Subjects: Milkweeds -- South Africa Milkweeds -- South Africa -- Ecology Milkweeds -- South Africa -- Pollination Allee effect Self-pollination Pollination by insects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4189 , http://hdl.handle.net/10962/d1003758
- Description: Like orchids, the complexity of flowers found in asclepiads (Asclepiadoideae, Apocynaceae) and the fact that pollen is presented as pollinaria, offers excellent opportunities to study various aspects of plant-pollinator interactions. In this thesis I investigated two broad themes: ecological aspects of the pollination biology of hymenopteran and fly-pollinated asclepiads as well as the degree of specialization to certain pollinators in these species. Colonizing plants often reproduce through self-pollination, or have highly generalized pollination systems, or both. These characteristics facilitate establishment in small founding populations and generates the prediction that reproductive success should be independent of population size in these species. Chapter one examines the pollination biology of Gomphocarpus physocarpus, an indigenous, weedy species and investigates the relationship between reproductive success and population size. In this species, there is no evidence of an Allee effect and reproductive success is not correlated with population size. In addition G. physocarpus is not capable of self-pollination, suggesting it is completely reliant on pollinators for seed set. The lack of a relationship between pollination success and population size is therefore likely explained by the generalized wasp pollination system of this species. Several milkweeds are invasive outside of their native ranges. Invasive species either need to co-opt native pollinators in order to reproduce or reduce their reliance on pollinators through having the ability to self-pollinate. Co-opting native pollinators is expected to be easier in species that have generalized pollination systems, alternatively species with specialized flower morphologies need to rely on similar functional groups of pollinators to be present within the invaded range. Chapter two investigates the pollination biology and pollination success of the invasive milkweed, Araujia sericifera, and finds that in South Africa, this species is visited mainly by native honeybees and nocturnal moths. Moths however contribute little to pollen removal, and deposition. Based on the apparent morphological mismatch between the flower of A. sericifera and native honeybees, I propose that the native pollinators of this species are likely to be larger Hymenoptera (e.g. Bumblebees). Data from a breeding system study, indicated that this species is not capable of automatic self-pollination, but could set fruit from geitonogamous self-pollinations pointing to the importance of native pollinators for successful reproduction. The pollinaria of milkweeds can accumulate on pollinators to form pollen masses large enough to physically interfere with the foraging behaviour of pollinating insects. In chapter three I describe the pollination biology of Cynanchum ellipticum and find that this species is mainly pollinated by honeybees although this species is visited by several other members of Hymenoptera, Lepidoptera and Diptera. Due to the structure of the pollinaria, these chain together relatively efficiently and frequently form large pollinarium loads on the mouthparts of honeybees. However there is little evidence that these pollinarium loads influence the foraging times of pollinators and only a few individual honeybees exhibited longer foraging times and most honeybees were unaffected by the presence of large pollinarium loads. Within the genus Cynanchum there is large variation in the gynostegium structure that may influence the pattern of pollinarium loading on pollinators as well as pollen reception as shown in chapter three. In Chapter four, the pollination biology of Cynanchum obtusifolium is examined, and like that of C. ellipticum, this species is visited by a wide diversity of pollinators but honeybees appear to be the primary pollinators. More importantly this species is shown to be andromonoecious and produces two morphologically different flower types, that may be distinguished based on differences in the gynostegium structure. These two types of flower could mainly be distinguished by the length of the anther wings. I found that flowers with short anther wings function as male flowers by only exporting- and rarely receiving pollinia. Flowers with longer anther wings function as hermaphrodite flowers and can both export and receive pollinia. The ratio of male to hermaphrodite flowers varied at different times during the flowering season, but preliminary data suggested that this was not related to levels of pollination success. The genera Stapelia and Ceropegia are well known for their intricate floral adaptations that mimic the brood and feeding substrates of pollinating flies. Despite several studies that have documented the various adaptations to fly pollination in different species, there is a lack of natural history studies documenting different flower visitors, pollen loads and long term levels of pollination success in these species. In Chapter six I document the pollination biology of Ceropegia ampliata by documenting different pollinators and quantifying average levels of pollination success and the nectar reward. I also experimentally manipulated the trapping hairs of this species to determine whether trapping hairs influence average levels of pollen export and receipt. I show that Ceropegia ampliata is pollinated by a generalist guild of flies (mainly Tachinidae, Sarcophagidae, Muscidae and Lauxaniidae) and produces minute quantities of relatively dilute nectar as a reward. Pollination success was generally low in this species and increases periodically suggesting that the abundance of pollinators is patchy. I found that flowers with trapping hairs that had already wilted had higher levels of pollinarium removal than flowers with erect hairs, however experimentally removing the hairs had no significant effect on pollen export and receipt. In Chapter seven, I document the pollinators, pollen loads and long term levels of pollination success in Stapelia hirsuta var. bayllissi, a rare sapromyiophilous stapeliad. I find that, in contrast to C. ampliata, this species was specialized to pollination by small flies of the family Anthomyiidae. Similar to the results from Chapter seven, I find that long term levels of pollination success were typically low but could increase periodically, although such increases were generally unpredictable. There are currently very few records documenting pollinator interactions in the Periplocoideae. Many species within this subfamily exhibit open-access flowers suggestive of pollination by short-tongued insects. I investigated the pollination biology of Chlorocyathus lobulata, a rare species with a highly localized distribution. I aimed to determine the pollinators, average levels of pollination success and demography of this species in order to determine whether this rare species is suffering from the collapse of a highly specialized pollinator mutualism. I also quantified the high incidence of flower herbivory caused by larvae of the moth, Bocchoris onychinalis. I find that C. lobulata has a highly generalized fly pollination system and average levels of pollination success suggested that a large proportion of flowers had pollen removed and deposited suggesting that this species is not experiencing pollination failure. The large numbers of juveniles present also indicated that recruitment is taking place.
- Full Text:
- Date Issued: 2010
Deliberating the Dialogues: a critical examination of the nature and purpose of a Daily Dispatch public journalism project
- Authors: Amner, Roderick John
- Date: 2010
- Subjects: Daily Dispatch (East London, South Africa) Journalism -- South Africa -- East London Citizen journalism -- South Africa -- East London
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3417 , http://hdl.handle.net/10962/d1002870
- Description: This thesis critically examines the nature and purpose of a series of four town-hall-like meetings, the Community Dialogues, held in the townships and suburbs of East London, South Africa, in 2009. They were undertaken by a mainstream, commercial newspaper, the Daily Dispatch, under the banner of the worldwide public journalism movement. Following Christians et al (2009), the thesis sets out a normative framework of media performance in a democracy, including a detailed and critical normative theory of the ‘facilitative role’ proposed and developed by Haas (2007), one of the public journalism movement’s key advocate-theorists. It also draws on a variety of theoretical frameworks and perspectives in the fields of Political Studies and Media Studies to provide an analytical overview of the complex matrix of political and media contexts – at the macro (global), meso (national) and micro (local) levels – that have helped give impetus to the Community Dialogues and also shaped their ongoing operation as a public journalism strategy in the South African context. Following a critical realist case study design, the thesis goes on to provide a narrative account of the Dialogues based on in-depth interviews exploring the motivations, self-understandings and perceptions of those journalists who originated, directed and participated in this project, as well as observation of a Community Dialogue, and an examination of some of the journalistic texts related to the Dialogues. This primary data is then critically evaluated against normative theories of press performance, especially Haas’s ‘public philosophy’ of public journalism. The thesis found that apart from their undoubted success in generating a more comprehensive and representative news agenda for the newspaper, the Dialogues often fell short of Habermas’s (1989) proceduralist-discursive notion of the ‘deliberating public’, which sees citizens share a commitment to engage in common deliberation and public problem solving. This can be attributed to a number of problems, including some important theoretical/conceptual weaknesses in the Community Dialogues’ project design, the relative immaturity of the project, the domination of civil society by political society in the South African political context, and a number of organisational constraints at the Daily Dispatch. On the other hand, the newspaper’s editorial leadership has shown clear commitment to the idea of expanding the project in the future, establishing a more a more structured programme of community engagement, and nurturing a more sustainable public sphere, including the building of a more dialectical relationship between the Dialogues and civil society.
- Full Text:
- Date Issued: 2010
- Authors: Amner, Roderick John
- Date: 2010
- Subjects: Daily Dispatch (East London, South Africa) Journalism -- South Africa -- East London Citizen journalism -- South Africa -- East London
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3417 , http://hdl.handle.net/10962/d1002870
- Description: This thesis critically examines the nature and purpose of a series of four town-hall-like meetings, the Community Dialogues, held in the townships and suburbs of East London, South Africa, in 2009. They were undertaken by a mainstream, commercial newspaper, the Daily Dispatch, under the banner of the worldwide public journalism movement. Following Christians et al (2009), the thesis sets out a normative framework of media performance in a democracy, including a detailed and critical normative theory of the ‘facilitative role’ proposed and developed by Haas (2007), one of the public journalism movement’s key advocate-theorists. It also draws on a variety of theoretical frameworks and perspectives in the fields of Political Studies and Media Studies to provide an analytical overview of the complex matrix of political and media contexts – at the macro (global), meso (national) and micro (local) levels – that have helped give impetus to the Community Dialogues and also shaped their ongoing operation as a public journalism strategy in the South African context. Following a critical realist case study design, the thesis goes on to provide a narrative account of the Dialogues based on in-depth interviews exploring the motivations, self-understandings and perceptions of those journalists who originated, directed and participated in this project, as well as observation of a Community Dialogue, and an examination of some of the journalistic texts related to the Dialogues. This primary data is then critically evaluated against normative theories of press performance, especially Haas’s ‘public philosophy’ of public journalism. The thesis found that apart from their undoubted success in generating a more comprehensive and representative news agenda for the newspaper, the Dialogues often fell short of Habermas’s (1989) proceduralist-discursive notion of the ‘deliberating public’, which sees citizens share a commitment to engage in common deliberation and public problem solving. This can be attributed to a number of problems, including some important theoretical/conceptual weaknesses in the Community Dialogues’ project design, the relative immaturity of the project, the domination of civil society by political society in the South African political context, and a number of organisational constraints at the Daily Dispatch. On the other hand, the newspaper’s editorial leadership has shown clear commitment to the idea of expanding the project in the future, establishing a more a more structured programme of community engagement, and nurturing a more sustainable public sphere, including the building of a more dialectical relationship between the Dialogues and civil society.
- Full Text:
- Date Issued: 2010