Developing principles for research about young women and abortion: a feminist analysis of difficulties in current South African studies
- Authors: Macleod, Catriona I
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6292 , http://hdl.handle.net/10962/d1014716
- Description: Soon after the first democratic elections in South Africa in 1994, the Choice on Termination of Pregnancy (CTOP) Act of 1996, which legalised abortion for the first time, was passed. Since the introduction of the CTOP, a number of studies have been conducted on abortion in South Africa. Many have taken a health-related focus, but some research on young women and abortion has also been conducted, and it is to this (published) research that this article speaks. Two facts highlight the importance of this kind of research in the context of the abortion debate. Firstly, data from the Department of Health indicate that from 1997 to mid-2006, 12% of women undergoing terminations in the provinces in which age-related data are available were under the age of 18 (Department of Health: 2006). Secondly, the subsection of the Act allowing minors to request abortions without parental consent has caused some controversy. For example, the Christian Lawyers Association filed a suit in the Pretoria High Court in 2003, arguing that the above-mentioned subsection was unconstitutional. Their application was not successful. The research conducted on young women and abortion is etched against a background of change and contradiction in young people’s lives in South Africa. In addition to enabling legislation on termination of pregnancy, which is premised on the rights-based approach of the first democratically elected government of South Africa, various opportunities and challenges define the lives of young women. Specifically in relation to sexual and reproductive health, the Department of Health’s National Adolescent Friendly Clinic Initiative aims to make family planning and other services more accessible and acceptable to young women (Dickson-Tetteh et al., 2001). However,HIV/AIDS and “safe sex” programmes define sex as dangerous and individual young women as responsible for close monitoring of heterosexual spaces. The Child Support Grant, shown to enable functional mothering (Case et al., 2005), has sparked controversy in terms of providing perverse incentives for poor young women to conceive (a claim refuted by the research – Makiwane & Udjo, 2005). Young, black and poor women who conceive are, in particular, stigmatised and teenage pregnancy is in many respects racialised (Macleod & Durrheim, 2002). In this paper I highlight some of the problems in the research conducted on young women and abortion in South Africa since the legalisation of abortion. The specific aim of the paper is, through this analysis, to draw out feminist principles that should be considered in this kind of research. My argument draws on postcolonial feminisms that theorise the multiplicity of oppression along gender and, inter alia, race, class, age and location lines (Macleod, 2006). The paper is premised on the assumption that, in a field as fraught with gendered, race and class politics as abortion, regardless of the method used, researchers need to inspect the ideological implications of their work, and to be vigilant about their scholastic practices, and any claims legitimately made.
- Full Text:
- Date Issued: 2008
- Authors: Macleod, Catriona I
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6292 , http://hdl.handle.net/10962/d1014716
- Description: Soon after the first democratic elections in South Africa in 1994, the Choice on Termination of Pregnancy (CTOP) Act of 1996, which legalised abortion for the first time, was passed. Since the introduction of the CTOP, a number of studies have been conducted on abortion in South Africa. Many have taken a health-related focus, but some research on young women and abortion has also been conducted, and it is to this (published) research that this article speaks. Two facts highlight the importance of this kind of research in the context of the abortion debate. Firstly, data from the Department of Health indicate that from 1997 to mid-2006, 12% of women undergoing terminations in the provinces in which age-related data are available were under the age of 18 (Department of Health: 2006). Secondly, the subsection of the Act allowing minors to request abortions without parental consent has caused some controversy. For example, the Christian Lawyers Association filed a suit in the Pretoria High Court in 2003, arguing that the above-mentioned subsection was unconstitutional. Their application was not successful. The research conducted on young women and abortion is etched against a background of change and contradiction in young people’s lives in South Africa. In addition to enabling legislation on termination of pregnancy, which is premised on the rights-based approach of the first democratically elected government of South Africa, various opportunities and challenges define the lives of young women. Specifically in relation to sexual and reproductive health, the Department of Health’s National Adolescent Friendly Clinic Initiative aims to make family planning and other services more accessible and acceptable to young women (Dickson-Tetteh et al., 2001). However,HIV/AIDS and “safe sex” programmes define sex as dangerous and individual young women as responsible for close monitoring of heterosexual spaces. The Child Support Grant, shown to enable functional mothering (Case et al., 2005), has sparked controversy in terms of providing perverse incentives for poor young women to conceive (a claim refuted by the research – Makiwane & Udjo, 2005). Young, black and poor women who conceive are, in particular, stigmatised and teenage pregnancy is in many respects racialised (Macleod & Durrheim, 2002). In this paper I highlight some of the problems in the research conducted on young women and abortion in South Africa since the legalisation of abortion. The specific aim of the paper is, through this analysis, to draw out feminist principles that should be considered in this kind of research. My argument draws on postcolonial feminisms that theorise the multiplicity of oppression along gender and, inter alia, race, class, age and location lines (Macleod, 2006). The paper is premised on the assumption that, in a field as fraught with gendered, race and class politics as abortion, regardless of the method used, researchers need to inspect the ideological implications of their work, and to be vigilant about their scholastic practices, and any claims legitimately made.
- Full Text:
- Date Issued: 2008
Development and validation of the Xhosa translations of the Beck Inventories: 1. Challenges of the translation process
- Steele, Gary I, Edwards, David J A
- Authors: Steele, Gary I , Edwards, David J A
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6248 , http://hdl.handle.net/10962/d1007866
- Description: This article describes the translation of the Beck Depression Inventory-II, the Beck Hopeless Scale, and the Beck Anxiety Inventory, into Xhosa the language spoken in the Eastern Cape of South Africa. The processes of translation, back-translation and committee discussion failed to yield trustworthy translations because of practical difficulties in working with translators. Critical words and phrases were identified which gave rise to lack of agreement. For each, a range of options was generated and the advantages and disadvantages evaluated in terms of criteria such as conceptual and idiomatic equivalence, and extensiveness of usage. Examples are given of the problems encountered and the way in which final decisions were made. A pilot clinical trial demonstrated the acceptability of the translated Instruments. Two further articles report the psychometric evaluation of the translated scales.
- Full Text:
- Date Issued: 2008
- Authors: Steele, Gary I , Edwards, David J A
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6248 , http://hdl.handle.net/10962/d1007866
- Description: This article describes the translation of the Beck Depression Inventory-II, the Beck Hopeless Scale, and the Beck Anxiety Inventory, into Xhosa the language spoken in the Eastern Cape of South Africa. The processes of translation, back-translation and committee discussion failed to yield trustworthy translations because of practical difficulties in working with translators. Critical words and phrases were identified which gave rise to lack of agreement. For each, a range of options was generated and the advantages and disadvantages evaluated in terms of criteria such as conceptual and idiomatic equivalence, and extensiveness of usage. Examples are given of the problems encountered and the way in which final decisions were made. A pilot clinical trial demonstrated the acceptability of the translated Instruments. Two further articles report the psychometric evaluation of the translated scales.
- Full Text:
- Date Issued: 2008
Development of a novel in situ CPRG-based biosensor and bioprobe for monitoring coliform β-D-Galactosidase in water polluted by faecal matter
- Authors: Wutor, Victor Collins
- Date: 2008
- Subjects: Biosensors Molecular probes Enterobacteriaceae Feces -- Microbiology Water -- Pollution -- Environmental aspects Environmental monitoring Chromogenic compounds
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3944 , http://hdl.handle.net/10962/d1004003
- Description: The ultimate objective of this work was to develop a real-time method for detecting and monitoring β-D-galactosidase as a suitable indicator of the potential presence of total coliform bacteria in water environments. Preliminary comparison of the chromogenic substrate, chlorophenol red β-D-galactopyranoside and the fluorogenic substrate, MuGAL, revealed unreliable results with the fluorogenic technique due to interference from compounds commonly found in environmental water samples. Thus, the chromogenic assay was further explored. Hydrolysis of the chromogenic substrate chlorophenol red β-D-galactopyranoside by β-D-galactosidase to yield chlorophenol red was the basis of this assay. Fundamental studies with chlorophenol red β-Dgalactopyranoside showed that β-D-galactosidase occurs extracellularly and in low concentrations in the polluted water environment. A direct correlation between enzyme activity and an increase in environmental water sample volume, as well as enzyme activity with total coliform colony forming unit counts were observed. Spectrophotometric detection was achieved within a maximum period of 24 h with a limit of detection level of 1 colony forming unit 100 ml[superscript -1]. This enzyme also exhibited physical and kinetic properties different from those of the pure commercially available β-D-galactosidase. Cell permeabilisation was not required for releasing enzymes into the extracellular environment. PEG 20 000 offered the best option for concentrating β-D-galactosidase. The source of β-D-galactosidase in the polluted environmental water samples was confirmed as Escherichia coli through SDS-PAGE, tryptic mapping and MALDI-TOF, thus justifying the further use of this method for detecting and/or monitoring total coliforms. Several compounds and metal ions commonly found in environmental water samples (as well as those used in water treatment processes) did have an effect on β-D-galactosidase. All the divalent cations except Mg [superscript 2+], at the concentrations studied, inhibited the relative activity of β-D-galactosidase in both commercial β-D-galactosidase and environmental samples. Immobilisation of chlorophenol red β-D-galactopyranoside onto a solid support material for the development of a strip bioprobe was unsuccessful, even though the nylon support material yielded some positive results. A monthly (seasonal) variation in β-Dgalactosidase activity from the environmental water samples was observed, with the highest activity coinciding with the highest monthly temperatures. Electro-oxidative detection and/or monitoring of chlorophenol red was possible. Chlorophenol red detection was linear over a wide range of concentrations (0.001-0.01 μg ml[superscript -1]). Interference by chlorophenol red β-D-galactopyranoside in the reduction window affected analysis. A range of phthalocyanine metal complexes were studied in an attempt to reduce fouling and/or increase the sensitivity of the biosensor. The selected phthalocyanine metal complexes were generally sensitive to changes in pH with a reduction in sensitivity from acidic pH to alkaline pH. The tetrasulphonated phthalocyanine metal complex of copper was, however, more stable with a minimum change of sensitivity. The phthalocyanine metal complexes were generally stable to changes in temperature. While only two consecutive scans were possible with the unmodified glassy carbon electrode, 77 consecutive scans were performed successfully with the CuPc-modified glassy carbon electrode. Among the phthalocyanine metal complexes studied, the CuPc-modified glassy carbon electrode therefore provided excellent results for the development of a biosensor. The CuPc modified-glassy carbon electrode detected 1 colony forming unit 100 ml[superscript -1] in 15 minutes, while the plain unmodified glassy carbon electrode required 6 hours to detect the equivalent number of colony forming units. CoPc, ZnPc and CuTSPc required 2, 2.25 and 1.75 h, respectively, to detect the same numbers of colony forming units. The CuPcmodified glassy carbon electrode detected 40 colony forming units 100 ml[superscript -1] instantly. In general, a direct correlation between colony forming units and current generated in the sensor was observed (R2=0.92). A higher correlation coefficient of 0.99 for 0-30 coliform colony forming units 100 ml[superscript -1] was determined. Current was detected in some water samples which did not show any colony forming units on the media, probably due to the phenomenon of viable but non-culturable bacteria, which is the major disadvantage encountered in the use of media for detecting indicator microorganisms. This novel biosensor therefore presents a very robust and sensitive technique for the detection and/or monitoring of coliform bacterial activity in water.
- Full Text:
- Date Issued: 2008
- Authors: Wutor, Victor Collins
- Date: 2008
- Subjects: Biosensors Molecular probes Enterobacteriaceae Feces -- Microbiology Water -- Pollution -- Environmental aspects Environmental monitoring Chromogenic compounds
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3944 , http://hdl.handle.net/10962/d1004003
- Description: The ultimate objective of this work was to develop a real-time method for detecting and monitoring β-D-galactosidase as a suitable indicator of the potential presence of total coliform bacteria in water environments. Preliminary comparison of the chromogenic substrate, chlorophenol red β-D-galactopyranoside and the fluorogenic substrate, MuGAL, revealed unreliable results with the fluorogenic technique due to interference from compounds commonly found in environmental water samples. Thus, the chromogenic assay was further explored. Hydrolysis of the chromogenic substrate chlorophenol red β-D-galactopyranoside by β-D-galactosidase to yield chlorophenol red was the basis of this assay. Fundamental studies with chlorophenol red β-Dgalactopyranoside showed that β-D-galactosidase occurs extracellularly and in low concentrations in the polluted water environment. A direct correlation between enzyme activity and an increase in environmental water sample volume, as well as enzyme activity with total coliform colony forming unit counts were observed. Spectrophotometric detection was achieved within a maximum period of 24 h with a limit of detection level of 1 colony forming unit 100 ml[superscript -1]. This enzyme also exhibited physical and kinetic properties different from those of the pure commercially available β-D-galactosidase. Cell permeabilisation was not required for releasing enzymes into the extracellular environment. PEG 20 000 offered the best option for concentrating β-D-galactosidase. The source of β-D-galactosidase in the polluted environmental water samples was confirmed as Escherichia coli through SDS-PAGE, tryptic mapping and MALDI-TOF, thus justifying the further use of this method for detecting and/or monitoring total coliforms. Several compounds and metal ions commonly found in environmental water samples (as well as those used in water treatment processes) did have an effect on β-D-galactosidase. All the divalent cations except Mg [superscript 2+], at the concentrations studied, inhibited the relative activity of β-D-galactosidase in both commercial β-D-galactosidase and environmental samples. Immobilisation of chlorophenol red β-D-galactopyranoside onto a solid support material for the development of a strip bioprobe was unsuccessful, even though the nylon support material yielded some positive results. A monthly (seasonal) variation in β-Dgalactosidase activity from the environmental water samples was observed, with the highest activity coinciding with the highest monthly temperatures. Electro-oxidative detection and/or monitoring of chlorophenol red was possible. Chlorophenol red detection was linear over a wide range of concentrations (0.001-0.01 μg ml[superscript -1]). Interference by chlorophenol red β-D-galactopyranoside in the reduction window affected analysis. A range of phthalocyanine metal complexes were studied in an attempt to reduce fouling and/or increase the sensitivity of the biosensor. The selected phthalocyanine metal complexes were generally sensitive to changes in pH with a reduction in sensitivity from acidic pH to alkaline pH. The tetrasulphonated phthalocyanine metal complex of copper was, however, more stable with a minimum change of sensitivity. The phthalocyanine metal complexes were generally stable to changes in temperature. While only two consecutive scans were possible with the unmodified glassy carbon electrode, 77 consecutive scans were performed successfully with the CuPc-modified glassy carbon electrode. Among the phthalocyanine metal complexes studied, the CuPc-modified glassy carbon electrode therefore provided excellent results for the development of a biosensor. The CuPc modified-glassy carbon electrode detected 1 colony forming unit 100 ml[superscript -1] in 15 minutes, while the plain unmodified glassy carbon electrode required 6 hours to detect the equivalent number of colony forming units. CoPc, ZnPc and CuTSPc required 2, 2.25 and 1.75 h, respectively, to detect the same numbers of colony forming units. The CuPcmodified glassy carbon electrode detected 40 colony forming units 100 ml[superscript -1] instantly. In general, a direct correlation between colony forming units and current generated in the sensor was observed (R2=0.92). A higher correlation coefficient of 0.99 for 0-30 coliform colony forming units 100 ml[superscript -1] was determined. Current was detected in some water samples which did not show any colony forming units on the media, probably due to the phenomenon of viable but non-culturable bacteria, which is the major disadvantage encountered in the use of media for detecting indicator microorganisms. This novel biosensor therefore presents a very robust and sensitive technique for the detection and/or monitoring of coliform bacterial activity in water.
- Full Text:
- Date Issued: 2008
Development of a reciprocating aerofoil wind energy harvester
- Authors: Phillips, Russell Leslie
- Date: 2008
- Subjects: Windmills , Wind power , Wind turbines
- Language: English
- Type: Thesis , Doctoral , DTech
- Identifier: vital:9622 , http://hdl.handle.net/10948/899 , Windmills , Wind power , Wind turbines
- Description: Cross flow wind turbines are not unique. The performance of Savonius and Darrieus turbines is well documented. Both share the advantage of being able to accept fluid flow from any direction. The Savonius is drag based and hence has poor power output while the Darrieus is lift based. Due to the fact that the Darrieus has fixed blades the fluid flow through the rotor does not result in optimal lift being generated at all points in the rotation circle. A drawback of the Darrieus system is that it has to operate at a high tip-to wind-speed ratio to obtain reasonable performance with the fixed blades. Deviation from a small optimal range of tip speed ratios results in poor performance. The Darrieus also has poor starting torque. The research conducted in this project focused on overcoming the shortcomings of other turbines and developing an effective cross flow turbine capable of good performance. A number of different concepts were experimented with, however all were based on a symmetrical aerofoil presented to the actual relative airflow at an angle that would produce the highest lift force at all times. The lift force was then utilized to generate movement and to do work on an electrical generator. All concepts contemplated were researched to ascertain their appropriateness for the intended application. During development of the final experimental platform and after lodging of a provisional patent (RSA 2007/00927) it was ascertained that the design shared some similarities with an American patent 5503525 dated 28/4/1994. This patent employed complex electronic sensing and control equipment for control of blade angle. This was thought to be overly complex and costly, particularly for small scale wind energy generation applications and a simpler mechanical solution was sought in the design of the final experimental platform used in this project. The design of the mechanical control system was refined in an attempt to make it simpler, more durable and employ the least number of moving parts. Literature studies and patent searches conducted, suggested that the mechanical control system as developed for the final experimental platform was unique. The enormous variation in the power available from the wind at the different wind speeds likely to be encountered by the device necessitated some means of control. In high wind conditions control of the amount of wind power into the device was deemed to be the preferable means of control. A number of different concepts to achieve this were devised and tested. The final concept employed limited the tail angle deflection and hence the lift produced by the aerofoils. This resulted in a seamless “throttle” control allowing the device to be used in any wind strength by adjusting the control to a position that resulted in the device receiving a suitable amount of power from the wind. The outcome of performance tests conducted indicated that the device has the potential to be developed into a viable wind turbine for both small and large scale applications. The ability to control the power input from the wind to the machine from zero to a maximum is considered to be one of the most beneficial outcomes of this project and together with the quiet operation and low speed, are considered the main advantages of the device over existing wind turbine designs. The possibilities of using the device to compress air for energy storage are exciting avenues that warrant further research.
- Full Text:
- Date Issued: 2008
- Authors: Phillips, Russell Leslie
- Date: 2008
- Subjects: Windmills , Wind power , Wind turbines
- Language: English
- Type: Thesis , Doctoral , DTech
- Identifier: vital:9622 , http://hdl.handle.net/10948/899 , Windmills , Wind power , Wind turbines
- Description: Cross flow wind turbines are not unique. The performance of Savonius and Darrieus turbines is well documented. Both share the advantage of being able to accept fluid flow from any direction. The Savonius is drag based and hence has poor power output while the Darrieus is lift based. Due to the fact that the Darrieus has fixed blades the fluid flow through the rotor does not result in optimal lift being generated at all points in the rotation circle. A drawback of the Darrieus system is that it has to operate at a high tip-to wind-speed ratio to obtain reasonable performance with the fixed blades. Deviation from a small optimal range of tip speed ratios results in poor performance. The Darrieus also has poor starting torque. The research conducted in this project focused on overcoming the shortcomings of other turbines and developing an effective cross flow turbine capable of good performance. A number of different concepts were experimented with, however all were based on a symmetrical aerofoil presented to the actual relative airflow at an angle that would produce the highest lift force at all times. The lift force was then utilized to generate movement and to do work on an electrical generator. All concepts contemplated were researched to ascertain their appropriateness for the intended application. During development of the final experimental platform and after lodging of a provisional patent (RSA 2007/00927) it was ascertained that the design shared some similarities with an American patent 5503525 dated 28/4/1994. This patent employed complex electronic sensing and control equipment for control of blade angle. This was thought to be overly complex and costly, particularly for small scale wind energy generation applications and a simpler mechanical solution was sought in the design of the final experimental platform used in this project. The design of the mechanical control system was refined in an attempt to make it simpler, more durable and employ the least number of moving parts. Literature studies and patent searches conducted, suggested that the mechanical control system as developed for the final experimental platform was unique. The enormous variation in the power available from the wind at the different wind speeds likely to be encountered by the device necessitated some means of control. In high wind conditions control of the amount of wind power into the device was deemed to be the preferable means of control. A number of different concepts to achieve this were devised and tested. The final concept employed limited the tail angle deflection and hence the lift produced by the aerofoils. This resulted in a seamless “throttle” control allowing the device to be used in any wind strength by adjusting the control to a position that resulted in the device receiving a suitable amount of power from the wind. The outcome of performance tests conducted indicated that the device has the potential to be developed into a viable wind turbine for both small and large scale applications. The ability to control the power input from the wind to the machine from zero to a maximum is considered to be one of the most beneficial outcomes of this project and together with the quiet operation and low speed, are considered the main advantages of the device over existing wind turbine designs. The possibilities of using the device to compress air for energy storage are exciting avenues that warrant further research.
- Full Text:
- Date Issued: 2008
Development of an integration model for the transport operators in the Nelson Mandela Bay area
- Authors: Pienaar, Jacques Ludolph
- Date: 2008
- Subjects: Urban transportation -- South Africa -- Port Elizabeth , Transportation -- South Africa -- Port Elizabeth -- Planning
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8722 , http://hdl.handle.net/10948/900 , Urban transportation -- South Africa -- Port Elizabeth , Transportation -- South Africa -- Port Elizabeth -- Planning
- Description: This research paper focuses on developing a model for the integration of the transport operators in the Nelson Mandela Bay area. The motivation for this integration is the Nelson Mandela Bay Municipality’s Public Transport Plan, which has set the goal of developing a new public transport system for the Metropolitan area. This system will integrate the different modes of transport into a single, seamless and scheduled service which will adhere to contractually enforced levels of quality, reliability and safety. In order to achieve this vision, the current bus and taxi operators will need to be unified into a viable and operational entity structure which will provide the required services to the public. The main research problem has therefore been identified as follows: How can the bus and taxi operators in Nelson Mandela Bay be integrated into a single entity, or small number of entities, in order to provide a viable, efficient and sustainable public transport service? This research paper sought to address this problem by conducting a case study of the Nelson Mandela Bay project, which took place over the course of a one year period. The author served as the project manager on the team that was responsible for developing the integration model. Additional research included a study visit to the cities of Bogota and Pereira in Colombia, which have implemented similar transport models, as well as a secondary study focusing on generic organisational integration strategies in existing literature. This paper is fundamentally a qualitative study. In this light, the research data was analysed according to the quasi-judicial method, which was deemed most suitable to the case study format adopted. The findings of the analysis were evaluated, and based on the resultant conclusions, a final integration model was recommended. The fact that this study is based on an actual project that has real world implications and consequences makes the result very relevant, and as such it will serve as a valuable addition to the body of knowledge which can be of assistance to other cities or project teams facing similar challenges in South Africa or even internationally.
- Full Text:
- Date Issued: 2008
- Authors: Pienaar, Jacques Ludolph
- Date: 2008
- Subjects: Urban transportation -- South Africa -- Port Elizabeth , Transportation -- South Africa -- Port Elizabeth -- Planning
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8722 , http://hdl.handle.net/10948/900 , Urban transportation -- South Africa -- Port Elizabeth , Transportation -- South Africa -- Port Elizabeth -- Planning
- Description: This research paper focuses on developing a model for the integration of the transport operators in the Nelson Mandela Bay area. The motivation for this integration is the Nelson Mandela Bay Municipality’s Public Transport Plan, which has set the goal of developing a new public transport system for the Metropolitan area. This system will integrate the different modes of transport into a single, seamless and scheduled service which will adhere to contractually enforced levels of quality, reliability and safety. In order to achieve this vision, the current bus and taxi operators will need to be unified into a viable and operational entity structure which will provide the required services to the public. The main research problem has therefore been identified as follows: How can the bus and taxi operators in Nelson Mandela Bay be integrated into a single entity, or small number of entities, in order to provide a viable, efficient and sustainable public transport service? This research paper sought to address this problem by conducting a case study of the Nelson Mandela Bay project, which took place over the course of a one year period. The author served as the project manager on the team that was responsible for developing the integration model. Additional research included a study visit to the cities of Bogota and Pereira in Colombia, which have implemented similar transport models, as well as a secondary study focusing on generic organisational integration strategies in existing literature. This paper is fundamentally a qualitative study. In this light, the research data was analysed according to the quasi-judicial method, which was deemed most suitable to the case study format adopted. The findings of the analysis were evaluated, and based on the resultant conclusions, a final integration model was recommended. The fact that this study is based on an actual project that has real world implications and consequences makes the result very relevant, and as such it will serve as a valuable addition to the body of knowledge which can be of assistance to other cities or project teams facing similar challenges in South Africa or even internationally.
- Full Text:
- Date Issued: 2008
Development of methodologies for deploying and implementing local & medium area broadband PLC networks in office and residential electric grids
- Authors: Tinarwo, Loyd
- Date: 2008
- Subjects: Broadband communication systems , Power transmission , Telecommunication lines
- Language: English
- Type: Thesis , Masters , MSc (Computer Science)
- Identifier: vital:11375 , http://hdl.handle.net/10353/83 , Broadband communication systems , Power transmission , Telecommunication lines
- Description: The use of electrical networks for telecommunications has a long history. It has been known since the beginning of the twentieth century [Ahola03]. The idea of using electrical networks for broadband communications arose in the 1990s [Hrasnica et al 04]. Recent and growing research interest has indicated that PowerLine Communications (PLC) is the threshold for achieving broadband delivery particularly in very dispersed and low teledensity areas. Currently, there are numerous PLC trials and commercial deployments underway inside and outside South Africa. Nevertheless, these PLC deployments are very isolated, done without clear methodology and performance remains bound to the physical layout of the electrical network. Because of that high bandwidth broadband PLC systems are prone to poor performance and this in turn limits the acceptance and deployment of this emerging alternative broadband technology. Though, PLC technical challenges are being addressed, there has been little analysis and research work that is focused on the “Development of Methodologies for Deploying and Implementing Local & Medium Area Broadband Power Line in Residential and Office Electric Grids” that would lead to broadband PLC being adopted and be of greater use to non-broadband communities of South Africa. PLC is a term describing several different systems using electrical grid distribution wires for simultaneous distribution of data by superimposing an analog signal [Hrasnica et al 04]. The research proposed and presented broadband PLC methodologies for typical medium voltage and local voltage PLC networks. These methodologieswere implemented and experimented with in configurations which closely mirrored residential and office settings through laboratory and multibuilding experiments using commercial 2nd Generation Mitsubishi Electric PLC technology. Research results presented not only serve to provide insight into broadband PLC but also how it handled broadband applications (communications), competed and compared with other technologies such as Ethernet LAN. In combination with networking communication theories, the research explored and analyzed the extent of PLC in providing broadband communication to residential and office electric grids at the University Fort Hare, Computer Science Department.
- Full Text:
- Date Issued: 2008
- Authors: Tinarwo, Loyd
- Date: 2008
- Subjects: Broadband communication systems , Power transmission , Telecommunication lines
- Language: English
- Type: Thesis , Masters , MSc (Computer Science)
- Identifier: vital:11375 , http://hdl.handle.net/10353/83 , Broadband communication systems , Power transmission , Telecommunication lines
- Description: The use of electrical networks for telecommunications has a long history. It has been known since the beginning of the twentieth century [Ahola03]. The idea of using electrical networks for broadband communications arose in the 1990s [Hrasnica et al 04]. Recent and growing research interest has indicated that PowerLine Communications (PLC) is the threshold for achieving broadband delivery particularly in very dispersed and low teledensity areas. Currently, there are numerous PLC trials and commercial deployments underway inside and outside South Africa. Nevertheless, these PLC deployments are very isolated, done without clear methodology and performance remains bound to the physical layout of the electrical network. Because of that high bandwidth broadband PLC systems are prone to poor performance and this in turn limits the acceptance and deployment of this emerging alternative broadband technology. Though, PLC technical challenges are being addressed, there has been little analysis and research work that is focused on the “Development of Methodologies for Deploying and Implementing Local & Medium Area Broadband Power Line in Residential and Office Electric Grids” that would lead to broadband PLC being adopted and be of greater use to non-broadband communities of South Africa. PLC is a term describing several different systems using electrical grid distribution wires for simultaneous distribution of data by superimposing an analog signal [Hrasnica et al 04]. The research proposed and presented broadband PLC methodologies for typical medium voltage and local voltage PLC networks. These methodologieswere implemented and experimented with in configurations which closely mirrored residential and office settings through laboratory and multibuilding experiments using commercial 2nd Generation Mitsubishi Electric PLC technology. Research results presented not only serve to provide insight into broadband PLC but also how it handled broadband applications (communications), competed and compared with other technologies such as Ethernet LAN. In combination with networking communication theories, the research explored and analyzed the extent of PLC in providing broadband communication to residential and office electric grids at the University Fort Hare, Computer Science Department.
- Full Text:
- Date Issued: 2008
Development of platinum metal specific separating agents
- Authors: Jonck, Heine
- Date: 2008
- Subjects: Platinum , Platinum -- Separation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10401 , http://hdl.handle.net/10948/712 , Platinum , Platinum -- Separation
- Description: In this dissertation, the aim was to develop a platinum specific resin to be utilized for the early removal of platinum from the industrial feed solution. Efforts were therefore directed towards the syntheses of silica based resins, with active centra, designed for platinum. The large chlorometallate ions present in the feed stream, were characterized in terms of physical parameters relevant to phase distribution, namely distortability (RD), charge density, softness (σ) etc. Matching cations for each of the types were investigated. In order to attempt the design of platinum specific resins, different structural amines were used to aminate the silicone precursor and to subsequently fix these onto the silica framework. Two different solvents namely alcohol and dmf were used in this process, resulting in two sets of resins, with different properties. The design was based on previous experience with these ions, with reference to their behaviour towards different types of cations. The platinum species, PtCl6 2- and PtCl4 2-, as well as the most important contaminants in the feed stream, were typified, bearing in mind size, charge, charge density and distortability. Different types of cationic centra, having differences in charge density, stereochemical crowding and extent of hydrophobicity, were synthesized and tested-both as solvent extractants (where possible) and silica based resins. The results indicated that, partly screened secondary ammonium cationic resin species, which could be regarded as “intermediate”, proved to be satisfactory both in their high percentage extraction for PtCl4 2- and rejection of contaminants like chlororhodates, chloroiridates(III) and FeCl4 -. It was however necessary, to work at a redox potential, where iridium(IV) in the form of IrCl6 2-, was absent. Various 2-aminoalkane resins were prepared, with variation in the length of alkane group and synthesised by the two different solvents. The latter resulted in two sets of resins with not only differing compactness, but also having significantly different properties with reference to platinum specificity, HCl effect and stripping potential. The 2-aminobutane and 2-aminoheptane resins in particular, proved to be very satisfactory platinum specific resins, both with respect to selectivity, platinum capacity and stripping potential. The various physical parameters could be applied to identify the chemical behaviour of anions and assist in the development of anion specificity for the relevant species.
- Full Text:
- Date Issued: 2008
- Authors: Jonck, Heine
- Date: 2008
- Subjects: Platinum , Platinum -- Separation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10401 , http://hdl.handle.net/10948/712 , Platinum , Platinum -- Separation
- Description: In this dissertation, the aim was to develop a platinum specific resin to be utilized for the early removal of platinum from the industrial feed solution. Efforts were therefore directed towards the syntheses of silica based resins, with active centra, designed for platinum. The large chlorometallate ions present in the feed stream, were characterized in terms of physical parameters relevant to phase distribution, namely distortability (RD), charge density, softness (σ) etc. Matching cations for each of the types were investigated. In order to attempt the design of platinum specific resins, different structural amines were used to aminate the silicone precursor and to subsequently fix these onto the silica framework. Two different solvents namely alcohol and dmf were used in this process, resulting in two sets of resins, with different properties. The design was based on previous experience with these ions, with reference to their behaviour towards different types of cations. The platinum species, PtCl6 2- and PtCl4 2-, as well as the most important contaminants in the feed stream, were typified, bearing in mind size, charge, charge density and distortability. Different types of cationic centra, having differences in charge density, stereochemical crowding and extent of hydrophobicity, were synthesized and tested-both as solvent extractants (where possible) and silica based resins. The results indicated that, partly screened secondary ammonium cationic resin species, which could be regarded as “intermediate”, proved to be satisfactory both in their high percentage extraction for PtCl4 2- and rejection of contaminants like chlororhodates, chloroiridates(III) and FeCl4 -. It was however necessary, to work at a redox potential, where iridium(IV) in the form of IrCl6 2-, was absent. Various 2-aminoalkane resins were prepared, with variation in the length of alkane group and synthesised by the two different solvents. The latter resulted in two sets of resins with not only differing compactness, but also having significantly different properties with reference to platinum specificity, HCl effect and stripping potential. The 2-aminobutane and 2-aminoheptane resins in particular, proved to be very satisfactory platinum specific resins, both with respect to selectivity, platinum capacity and stripping potential. The various physical parameters could be applied to identify the chemical behaviour of anions and assist in the development of anion specificity for the relevant species.
- Full Text:
- Date Issued: 2008
Die liturgiese gebruik van die orrel in 'n post-mordene era: persepsies van kerkmusici en leraars van die Nederduitse Gereformeerde gemeentes in Port Elizabeth
- Authors: Heunis, Sulani
- Date: 2008
- Subjects: Organ music -- South Africa -- Port Elizabeth , Chorale preludes
- Language: Afrikaans
- Type: Thesis , Masters , MMus
- Identifier: vital:8511 , http://hdl.handle.net/10948/787 , Organ music -- South Africa -- Port Elizabeth , Chorale preludes
- Description: In this study the liturgical usage of the organ is investigated within a post-modern society. It focuses specifically on the church services of the Dutch Reformed Congregations of Port Elizabeth with regards to the functionality of the organ during morning and evening services. The objectives of the study are to demonstrate the current situation of musical worship in the Dutch Reformed Congregations of Port Elizabeth. Furthermore it serves as a way to indicate any deficiency in the field, which would need to be addressed. In order to achieve these objectives, both a qualitative and quantitative study is undertaken. The qualitative study investigates existing literature regarding the church service and its music. The quantitative study comprises an analysis of self-administered questionnaires that was handed over for completion by the Dutch Reformed Congregations of Port Elizabeth. The results obtained were electronically processed to percentages and graphic illustrations. In this mini-treatise it is argued that the usage of other music instruments (in the form of music worship groups) during church services could possibly lead to a change in the liturgical function of the organ. It was found that the usage of the organ in the Dutch Reformed Congregations of Port Elizabeth was mainly retained during morning services. During evening services however, the usage of other music instruments was in the majority, which resulted in a decrease of organ usage. It was further discovered that a large group of organists are not involved with music worship groups. Training of organists in a contemporary style of music worship will therefore serve as a significant purpose to fulfil this deficiency.
- Full Text:
- Date Issued: 2008
- Authors: Heunis, Sulani
- Date: 2008
- Subjects: Organ music -- South Africa -- Port Elizabeth , Chorale preludes
- Language: Afrikaans
- Type: Thesis , Masters , MMus
- Identifier: vital:8511 , http://hdl.handle.net/10948/787 , Organ music -- South Africa -- Port Elizabeth , Chorale preludes
- Description: In this study the liturgical usage of the organ is investigated within a post-modern society. It focuses specifically on the church services of the Dutch Reformed Congregations of Port Elizabeth with regards to the functionality of the organ during morning and evening services. The objectives of the study are to demonstrate the current situation of musical worship in the Dutch Reformed Congregations of Port Elizabeth. Furthermore it serves as a way to indicate any deficiency in the field, which would need to be addressed. In order to achieve these objectives, both a qualitative and quantitative study is undertaken. The qualitative study investigates existing literature regarding the church service and its music. The quantitative study comprises an analysis of self-administered questionnaires that was handed over for completion by the Dutch Reformed Congregations of Port Elizabeth. The results obtained were electronically processed to percentages and graphic illustrations. In this mini-treatise it is argued that the usage of other music instruments (in the form of music worship groups) during church services could possibly lead to a change in the liturgical function of the organ. It was found that the usage of the organ in the Dutch Reformed Congregations of Port Elizabeth was mainly retained during morning services. During evening services however, the usage of other music instruments was in the majority, which resulted in a decrease of organ usage. It was further discovered that a large group of organists are not involved with music worship groups. Training of organists in a contemporary style of music worship will therefore serve as a significant purpose to fulfil this deficiency.
- Full Text:
- Date Issued: 2008
Diet and feeding effects of introduced giraffe in the Eastern Cape
- Authors: Jacobs, Evert Philippus
- Date: 2008
- Subjects: Giraffe -- Food -- South Africa -- Eastern Cape , Giraffe -- Ecology -- South Africa -- Eastern Cape , Animal-plant relationships -- South Africa -- Eastern Cape , Introduced mammals -- Ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10703 , http://hdl.handle.net/10948/964 , Giraffe -- Food -- South Africa -- Eastern Cape , Giraffe -- Ecology -- South Africa -- Eastern Cape , Animal-plant relationships -- South Africa -- Eastern Cape , Introduced mammals -- Ecology -- South Africa -- Eastern Cape
- Description: This study presents the results of a study on introduced giraffe diet and feeding effects within the Eastern Cape Province of South Africa. Five sites were selected over a moisture gradient from the mesic east to the arid west of the Eastern Cape to describe giraffe diet and provide baseline data for feeding effect experiments. At each site faecal samples were collected seasonally and diet composition determined by microhistological analysis. Plant species availability was measured using the point intersect method in order to compare plant availability to plant consumption to determine diet preferences. Giraffe diet across the sites showed a unimodal response to rainfall by utilising fewer species in drier areas where plant availability is low and increasing the number of species consumed as the rainfall increases. In higher rainfall areas, giraffe reduced the number of plant species fed upon because of the high availability of important species that reduces the need for a varied diet. Across all sites, plant availability was dominated by woody plant species (more than 90 percent at each site). A total of 57 plants species were recorded as being eaten across the five sites. Several PDI (Principle Diet Items) plant species (Acacia karroo, Schotia afra, Pappea capensis and Euclea undulata) were eaten across sites. Over all the sites, significantly preferred species were Asparagus striatus, Schotia latifolia, Asparagus suaveolens, Commelina benghalensis, Viscum rotundifolium, and Acacia cyclops. Acacia karroo, Schotia afra, Pappea capensis, Rhus crenata, A. tetracantha, and Grewia robusta were utilised in proportion to their availability. Euclea undulata, Rhus longispina and Putterlickia pyracantha were avoided. Feeding effects were tested by erecting exclosures around trees, covering one half of each tree. Ten trees were selected for these manipulative experiments which ran from September 2003 to February 2005. The number of branches, number of leaves, branch orders, branch diameter, branch length, leaf length and leaf width were measured for ten samples per side (enclosed vs. exposed) and analysed using a Wilcoxon matched pairs test and tested for effect size using Cohen’s d. Although no significant differences were detected between the sides measured, the effect size indicated differences in all measurements between sides ranging from low to moderate. Leaf length was greater on the outside of exclosures and showed a moderate difference between the sides in terms of the d-value with the p-value (0.059) tending towards significance. Although leaf width was higher on the inside of exclosures, it only showed a moderate difference for d with no statistical significance. Leaf area was higher on the inside of exclosures and tended to significance (p = 0.059) and similarly the d value indicated moderate differences between the sides in terms of effect size. Similarly branch length was higher on the inside of exclosures although not significantly, the p-value (0.07) approached significance. The effect size for branch length also showed a moderate difference between the sides. The number of branches and the number of leaves showed no statistical differences between the sides although the p-value (0.059) for the number of branches, as well as number of leaves (p = 0.07) approached significance. For both these variables, effect size showed a moderate difference. Giraffe showed diversity in their diet selection across sites but mainly fed upon available species. Some preferred species were however less available and this preference could possibly result in increased pressure on the selected plant species Exclosure experiments showed no significant differences in leaf and shoot characteristics although all measurements showed differences in terms of effect size meriting further investigation. It is concluded that giraffe impact on sites may be reduced if populations are properly managed however, high densities of giraffe could lead to similar vegetation impacts as observed in other areas where giraffe have been introduced and potentially change vegetation structure and plant community composition.
- Full Text:
- Date Issued: 2008
- Authors: Jacobs, Evert Philippus
- Date: 2008
- Subjects: Giraffe -- Food -- South Africa -- Eastern Cape , Giraffe -- Ecology -- South Africa -- Eastern Cape , Animal-plant relationships -- South Africa -- Eastern Cape , Introduced mammals -- Ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10703 , http://hdl.handle.net/10948/964 , Giraffe -- Food -- South Africa -- Eastern Cape , Giraffe -- Ecology -- South Africa -- Eastern Cape , Animal-plant relationships -- South Africa -- Eastern Cape , Introduced mammals -- Ecology -- South Africa -- Eastern Cape
- Description: This study presents the results of a study on introduced giraffe diet and feeding effects within the Eastern Cape Province of South Africa. Five sites were selected over a moisture gradient from the mesic east to the arid west of the Eastern Cape to describe giraffe diet and provide baseline data for feeding effect experiments. At each site faecal samples were collected seasonally and diet composition determined by microhistological analysis. Plant species availability was measured using the point intersect method in order to compare plant availability to plant consumption to determine diet preferences. Giraffe diet across the sites showed a unimodal response to rainfall by utilising fewer species in drier areas where plant availability is low and increasing the number of species consumed as the rainfall increases. In higher rainfall areas, giraffe reduced the number of plant species fed upon because of the high availability of important species that reduces the need for a varied diet. Across all sites, plant availability was dominated by woody plant species (more than 90 percent at each site). A total of 57 plants species were recorded as being eaten across the five sites. Several PDI (Principle Diet Items) plant species (Acacia karroo, Schotia afra, Pappea capensis and Euclea undulata) were eaten across sites. Over all the sites, significantly preferred species were Asparagus striatus, Schotia latifolia, Asparagus suaveolens, Commelina benghalensis, Viscum rotundifolium, and Acacia cyclops. Acacia karroo, Schotia afra, Pappea capensis, Rhus crenata, A. tetracantha, and Grewia robusta were utilised in proportion to their availability. Euclea undulata, Rhus longispina and Putterlickia pyracantha were avoided. Feeding effects were tested by erecting exclosures around trees, covering one half of each tree. Ten trees were selected for these manipulative experiments which ran from September 2003 to February 2005. The number of branches, number of leaves, branch orders, branch diameter, branch length, leaf length and leaf width were measured for ten samples per side (enclosed vs. exposed) and analysed using a Wilcoxon matched pairs test and tested for effect size using Cohen’s d. Although no significant differences were detected between the sides measured, the effect size indicated differences in all measurements between sides ranging from low to moderate. Leaf length was greater on the outside of exclosures and showed a moderate difference between the sides in terms of the d-value with the p-value (0.059) tending towards significance. Although leaf width was higher on the inside of exclosures, it only showed a moderate difference for d with no statistical significance. Leaf area was higher on the inside of exclosures and tended to significance (p = 0.059) and similarly the d value indicated moderate differences between the sides in terms of effect size. Similarly branch length was higher on the inside of exclosures although not significantly, the p-value (0.07) approached significance. The effect size for branch length also showed a moderate difference between the sides. The number of branches and the number of leaves showed no statistical differences between the sides although the p-value (0.059) for the number of branches, as well as number of leaves (p = 0.07) approached significance. For both these variables, effect size showed a moderate difference. Giraffe showed diversity in their diet selection across sites but mainly fed upon available species. Some preferred species were however less available and this preference could possibly result in increased pressure on the selected plant species Exclosure experiments showed no significant differences in leaf and shoot characteristics although all measurements showed differences in terms of effect size meriting further investigation. It is concluded that giraffe impact on sites may be reduced if populations are properly managed however, high densities of giraffe could lead to similar vegetation impacts as observed in other areas where giraffe have been introduced and potentially change vegetation structure and plant community composition.
- Full Text:
- Date Issued: 2008
Disgrace as J.M.Coetzee's Tempest
- Authors: Wright, Laurence
- Date: 2008
- Language: English
- Type: Book chapter
- Identifier: vital:7030 , http://hdl.handle.net/10962/d1007217
- Description: Amid the deluge of criticism and commentary evoked by Disgrace, quite remarkably nobody has noticed that the book re-engages exactly the energies Shakespeare deployed in The Tempest, a play which has become an icon, if not the icon, of colonial and post-colonial studies.
- Full Text:
- Date Issued: 2008
- Authors: Wright, Laurence
- Date: 2008
- Language: English
- Type: Book chapter
- Identifier: vital:7030 , http://hdl.handle.net/10962/d1007217
- Description: Amid the deluge of criticism and commentary evoked by Disgrace, quite remarkably nobody has noticed that the book re-engages exactly the energies Shakespeare deployed in The Tempest, a play which has become an icon, if not the icon, of colonial and post-colonial studies.
- Full Text:
- Date Issued: 2008
Do environmental factors influence the movement of estuarine fish? A case study using acoustic telemetry
- Childs, Amber-Robyn, Cowley, Paul D, Næsje, T F, Booth, Anthony J, Thorstad, Eva B, Økland, F
- Authors: Childs, Amber-Robyn , Cowley, Paul D , Næsje, T F , Booth, Anthony J , Thorstad, Eva B , Økland, F
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6772 , http://hdl.handle.net/10962/d1008070
- Description: Telemetry methods were used to investigate the influence of selected environmental variables on the position and movement of an estuarine-dependent haemulid, the spotted grunter Pomadasys commersonnii (Lacepède 1801), in the Great Fish Estuary, South Africa. Forty individuals (263–698 mm TL) were surgically implanted with acoustic coded transmitters and manually tracked during two periods (7 February to 24 March 2003; n = 20 and 29 September to 15 November 2003; n = 20). Real-time data revealed that spotted grunter are euryhaline (0–37) and are able to tolerate large variations in turbidity (4–356 FTU) and temperature (16–30 °C). However, the fish altered their position in response to large fluctuations in salinity, temperature and turbidity, which are characteristic of tidal estuarine environments. Furthermore, tidal phase had a strong influence on the position of spotted grunter in the estuary.
- Full Text:
- Date Issued: 2008
- Authors: Childs, Amber-Robyn , Cowley, Paul D , Næsje, T F , Booth, Anthony J , Thorstad, Eva B , Økland, F
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6772 , http://hdl.handle.net/10962/d1008070
- Description: Telemetry methods were used to investigate the influence of selected environmental variables on the position and movement of an estuarine-dependent haemulid, the spotted grunter Pomadasys commersonnii (Lacepède 1801), in the Great Fish Estuary, South Africa. Forty individuals (263–698 mm TL) were surgically implanted with acoustic coded transmitters and manually tracked during two periods (7 February to 24 March 2003; n = 20 and 29 September to 15 November 2003; n = 20). Real-time data revealed that spotted grunter are euryhaline (0–37) and are able to tolerate large variations in turbidity (4–356 FTU) and temperature (16–30 °C). However, the fish altered their position in response to large fluctuations in salinity, temperature and turbidity, which are characteristic of tidal estuarine environments. Furthermore, tidal phase had a strong influence on the position of spotted grunter in the estuary.
- Full Text:
- Date Issued: 2008
Drought responses of C3 and C4 (NADP-ME) Panicoid grasses
- Authors: Frole, Kristen Marie
- Date: 2008
- Subjects: Botany -- Research , Grasses -- Physiology -- South Africa , Grasses -- Effect of drought on , Grasses -- Drought tolerance , Plant-water relationships
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4193 , http://hdl.handle.net/10962/d1003762 , Botany -- Research , Grasses -- Physiology -- South Africa , Grasses -- Effect of drought on , Grasses -- Drought tolerance , Plant-water relationships
- Description: The success of C₄ plants lies in their ability to concentrate CO₂ at the site of Rubisco thereby conferring greater efficiencies of light, water and nitrogen. Such characteristics should advantage C₄ plants in arid, hot environments. However, not all C₄ subtypes are drought tolerant. The relative abundance of NADP-ME species declines with increasing aridity. Furthermore, selected species have been demonstrated as being susceptible to severe drought showing metabolic limitations of photosynthesis. However there is a lack of phylogenetic control with many of these studies. The aims of this study were to determine whether the NADP-ME subtype was inherently susceptible to drought by comparing six closely related C₃ and C₄ (NADP-ME) Panicoid grasses. Gas exchange measurements were made during a natural rainless period and a controlled drought / rewatering event. Prior to water stress, the C₄ species had higher assimilation rates (A), and water use efficiencies (WUE[subscript leaf]) than the C₃ species, while transpiration rates (E) and stomatal conductances (g[subscript s]) were similar. At low soil water content, the C₃ species reduced gs by a greater extent than the C₄ species, which maintained higher E during the driest periods. The C₄ species showed proportionally greater reductions in A than the C₃ species and hence lost their WUE[subscript leaf] and photosynthetic advantage. CO₂ response curves showed that metabolic limitation was responsible for a greater decrease in A in the C₄ type than the C₃ type during progressive drought. Upon re-watering, photosynthetic recovery was quicker in the C species than the C₄ species. Results from whole plant measurements showed that the C₄ type had a significant whole plant water use efficiency advantage over the C₃ type under well-watered conditions that was lost during severe drought due to a greater loss of leaf area through leaf mortality rather than reductions in plant level transpiration rates. The C₃ type had xylem characteristics that enhanced water-conducting efficiency, but made them vulnerable to drought. This is in contrast to the safer xylem qualities of the C₄ type, which permitted the endurance of more negative leaf water potentials than the C₃ type during low soil water content. Thus, the vulnerability of photosynthesis to severe drought in NADP-ME species potentially explains why NADP-ME species abundance around the world decreases with decreasing rainfall.
- Full Text:
- Date Issued: 2008
- Authors: Frole, Kristen Marie
- Date: 2008
- Subjects: Botany -- Research , Grasses -- Physiology -- South Africa , Grasses -- Effect of drought on , Grasses -- Drought tolerance , Plant-water relationships
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4193 , http://hdl.handle.net/10962/d1003762 , Botany -- Research , Grasses -- Physiology -- South Africa , Grasses -- Effect of drought on , Grasses -- Drought tolerance , Plant-water relationships
- Description: The success of C₄ plants lies in their ability to concentrate CO₂ at the site of Rubisco thereby conferring greater efficiencies of light, water and nitrogen. Such characteristics should advantage C₄ plants in arid, hot environments. However, not all C₄ subtypes are drought tolerant. The relative abundance of NADP-ME species declines with increasing aridity. Furthermore, selected species have been demonstrated as being susceptible to severe drought showing metabolic limitations of photosynthesis. However there is a lack of phylogenetic control with many of these studies. The aims of this study were to determine whether the NADP-ME subtype was inherently susceptible to drought by comparing six closely related C₃ and C₄ (NADP-ME) Panicoid grasses. Gas exchange measurements were made during a natural rainless period and a controlled drought / rewatering event. Prior to water stress, the C₄ species had higher assimilation rates (A), and water use efficiencies (WUE[subscript leaf]) than the C₃ species, while transpiration rates (E) and stomatal conductances (g[subscript s]) were similar. At low soil water content, the C₃ species reduced gs by a greater extent than the C₄ species, which maintained higher E during the driest periods. The C₄ species showed proportionally greater reductions in A than the C₃ species and hence lost their WUE[subscript leaf] and photosynthetic advantage. CO₂ response curves showed that metabolic limitation was responsible for a greater decrease in A in the C₄ type than the C₃ type during progressive drought. Upon re-watering, photosynthetic recovery was quicker in the C species than the C₄ species. Results from whole plant measurements showed that the C₄ type had a significant whole plant water use efficiency advantage over the C₃ type under well-watered conditions that was lost during severe drought due to a greater loss of leaf area through leaf mortality rather than reductions in plant level transpiration rates. The C₃ type had xylem characteristics that enhanced water-conducting efficiency, but made them vulnerable to drought. This is in contrast to the safer xylem qualities of the C₄ type, which permitted the endurance of more negative leaf water potentials than the C₃ type during low soil water content. Thus, the vulnerability of photosynthesis to severe drought in NADP-ME species potentially explains why NADP-ME species abundance around the world decreases with decreasing rainfall.
- Full Text:
- Date Issued: 2008
Dumping, antidumping and the future prospects for fair international trade
- Authors: Zvidza, Tinevimbo
- Date: 2008
- Subjects: Dumping -- International trade -- International trade -- Fair trad , Foreign trade regulation -- International cooperation
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:11114 , http://hdl.handle.net/10353/100 , Dumping -- International trade -- International trade -- Fair trad , Foreign trade regulation -- International cooperation
- Description: More than a century has passed since Canada adopted the first antidumping law in 1904. Similar legislation in most of the major trading nations followed the Canadian legislation prior to and after the World War II. Antidumping provisions were later integrated into the General Agreement on Tariffs and Trade (GATT) after the said war. Today, nearly all developed and developing countries have this type of legislation in place within their municipal legal framework. The subject of antidumping has received growing attention in international trade policy and has become a source of tension between trading nations. This is evident in the substantial increase of antidumping actions since the establishment of the WTO. Antidumping policy has emerged as a significant trade barrier because of its misuse by both developed and developing countries. The primary instruments governing antidumping actions are GATT Article VI and the Antidumping Agreement (ADA). The ADA contains both the substantive and procedural rules governing the interpretation and application of the instrument. Its purpose is to ensure that the instrument is used only as a contingency measure judged upon merit and not as a disguised protectionist device. Given the growing number of countries participating more actively in the world trading system and the notorious misuse of antidumping provisions, there is a vital need to critically analyse the key provisions of the said instruments. This study is an attempt at that academic enterprise. It concludes by giving proposals for future reform of both real and potential future reform of the current WTO antidumping regime. Dumping, antidumping, antidumping regulation, antidumping duties, like products, dumping margin, zeroing, facts available, protectionism, ADA.
- Full Text:
- Date Issued: 2008
- Authors: Zvidza, Tinevimbo
- Date: 2008
- Subjects: Dumping -- International trade -- International trade -- Fair trad , Foreign trade regulation -- International cooperation
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:11114 , http://hdl.handle.net/10353/100 , Dumping -- International trade -- International trade -- Fair trad , Foreign trade regulation -- International cooperation
- Description: More than a century has passed since Canada adopted the first antidumping law in 1904. Similar legislation in most of the major trading nations followed the Canadian legislation prior to and after the World War II. Antidumping provisions were later integrated into the General Agreement on Tariffs and Trade (GATT) after the said war. Today, nearly all developed and developing countries have this type of legislation in place within their municipal legal framework. The subject of antidumping has received growing attention in international trade policy and has become a source of tension between trading nations. This is evident in the substantial increase of antidumping actions since the establishment of the WTO. Antidumping policy has emerged as a significant trade barrier because of its misuse by both developed and developing countries. The primary instruments governing antidumping actions are GATT Article VI and the Antidumping Agreement (ADA). The ADA contains both the substantive and procedural rules governing the interpretation and application of the instrument. Its purpose is to ensure that the instrument is used only as a contingency measure judged upon merit and not as a disguised protectionist device. Given the growing number of countries participating more actively in the world trading system and the notorious misuse of antidumping provisions, there is a vital need to critically analyse the key provisions of the said instruments. This study is an attempt at that academic enterprise. It concludes by giving proposals for future reform of both real and potential future reform of the current WTO antidumping regime. Dumping, antidumping, antidumping regulation, antidumping duties, like products, dumping margin, zeroing, facts available, protectionism, ADA.
- Full Text:
- Date Issued: 2008
Dungamanzi/stirring waters: Tsonga and Shangaan art from southern Africa, Nessa Leibhammer (Ed.): book reviews
- Authors: Simbao, Ruth K
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147358 , vital:38629 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC31053
- Description: A woman known as Nkoma We Lwandle (Cow of the Ocean) and a man, Dunga Manzi (Stirring Waters), are remembered as the first Tsonga diviners. Trained by Nzunzu - a powerful water serpent - they were pulled into a lake for a few months and later emerged as influential healers. Such stories (like the one relayed by Dederen of a young girl, Nsatimuni, who also temporarily disappeared into a lake) represent 'death' and 'rebirth', reflecting Arnold van Gennep's (1909) well-known schema of rites de passage: séparation, marge, and agrégation. Separated from daily life, these characters sink into another world where people breathe in water like a foetus in the liquid depths of a womb, evoking impending new birth (p. 171).
- Full Text:
- Date Issued: 2008
- Authors: Simbao, Ruth K
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147358 , vital:38629 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC31053
- Description: A woman known as Nkoma We Lwandle (Cow of the Ocean) and a man, Dunga Manzi (Stirring Waters), are remembered as the first Tsonga diviners. Trained by Nzunzu - a powerful water serpent - they were pulled into a lake for a few months and later emerged as influential healers. Such stories (like the one relayed by Dederen of a young girl, Nsatimuni, who also temporarily disappeared into a lake) represent 'death' and 'rebirth', reflecting Arnold van Gennep's (1909) well-known schema of rites de passage: séparation, marge, and agrégation. Separated from daily life, these characters sink into another world where people breathe in water like a foetus in the liquid depths of a womb, evoking impending new birth (p. 171).
- Full Text:
- Date Issued: 2008
Eco-Schools and the quality of education in South Africa: Realising the potential
- Authors: Rosenberg, Eureta
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/370511 , vital:66349 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122759"
- Description: Eco-Schools South Africa is increasingly being used by external partners as a framework for supporting environmental education in schools. This paper shares the findings of a recent evaluation of the programme in relation to the quality of education in South African schools. Do Eco-Schools activities help to improve the conditions of teaching and learning? Or do they take teachers and students away from their core focus? Evaluation of learner and teacher work in Eco-Schools found signs of the quality problems that currently plague the schools system, and there is evidence that the programme can add to the complexity to which many teachers struggle to respond. The evaluation also found, however, that the programme has significant potential to improve conditions for teaching and learning. The paper is an opportunity to reflect on how environmental education support for schools, in general, and Eco-Schools South Africa, in particular, can detract from and strengthen teaching and learning.
- Full Text:
- Date Issued: 2008
- Authors: Rosenberg, Eureta
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/370511 , vital:66349 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122759"
- Description: Eco-Schools South Africa is increasingly being used by external partners as a framework for supporting environmental education in schools. This paper shares the findings of a recent evaluation of the programme in relation to the quality of education in South African schools. Do Eco-Schools activities help to improve the conditions of teaching and learning? Or do they take teachers and students away from their core focus? Evaluation of learner and teacher work in Eco-Schools found signs of the quality problems that currently plague the schools system, and there is evidence that the programme can add to the complexity to which many teachers struggle to respond. The evaluation also found, however, that the programme has significant potential to improve conditions for teaching and learning. The paper is an opportunity to reflect on how environmental education support for schools, in general, and Eco-Schools South Africa, in particular, can detract from and strengthen teaching and learning.
- Full Text:
- Date Issued: 2008
Ecological role of free-living bacteria in the microbial food web of the temporarily open/closed East Kleinemonde Estuary, South Africa
- Authors: Allan, Elizabeth Louise
- Date: 2008
- Subjects: Bacterial growth -- South Africa -- Eastern Cape , Estuarine ecology -- South Africa -- Eastern Cape , Estuaries -- South Africa -- Eastern Cape , Microbial ecology -- South Africa -- Eastern Cape , Nutrient cycles -- South Africa -- Eastern Cape , Food chains (Ecology)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5666 , http://hdl.handle.net/10962/d1005351 , Bacterial growth -- South Africa -- Eastern Cape , Estuarine ecology -- South Africa -- Eastern Cape , Estuaries -- South Africa -- Eastern Cape , Microbial ecology -- South Africa -- Eastern Cape , Nutrient cycles -- South Africa -- Eastern Cape , Food chains (Ecology)
- Description: The main aim of this study was to assess the “top-down” and “bottom-up” control of bacterial production in the small temporarily open/closed East Kleinemonde Estuary, situated on the south-eastern coastline of southern Africa. Spatial and temporal patterns in bacterial abundance, biomass and production and the importance of abiotic and biotic factors were investigated over the period May 2006 to April 2007. The trophic interactions between bacteria, phytoplankton, nanoflagellates (< 20 μm), microzooplankton (< 200 μm) and mesozooplankton (< 2 000 μm) were investigated during winter and summer. Bacterial abundance, biomass and production ranged between 1.00 × 10⁹ and 4.93 × 10⁹ cells 1⁻¹, 32.4 and 109 μg C 1⁻¹ and 0.01 and 1.99 μg C 1⁻¹ h⁻¹, respectively. With a few exceptions there were no spatial patterns in the values. Bacterial abundance, biomass and production, however, demonstrated a distinct temporal pattern with the lowest values consistently recorded during the winter months. Nanoflagellate and bacterial abundances were significantly correlated to one another (lower reaches: r = 0.818, p < 0.001; middle reaches: r = 0.628, p < 0.001; upper reaches: r = 0.484, p < 0.05) suggesting a strong predator-prey relationship. The frequency of visibly infected bacterial cells and the mean number of virus particles within each bacterial cell during this study demonstrated no temporal or spatial patterns and ranged from 0.5 to 6.1 % and 12.0 to 37.5 virus particles per bacterium, respectively. Viral infection and lysis was thus a constant source of bacterial mortality throughout the year. The estimated percentage of bacterial production removed by viral lysis ranged between 7.8 and 88.9% of the total which suggests that viral lysis represented a very important source of bacterial mortality during this study. The biological interactions between the selected components of the plankton community demonstrated that among the heterotrophic components of the plankton, the nanoflagellates were identified as the most important consumers of bacteria and small phytoplankton cells (< 20 μm). In the presence of microzooplankton the impact of the nanoflagellates on both the bacteria and phytoplankton was reduced, indicating that larger heterotrophs were preying upon the nanoflagellates. Mesozooplankton, however, appeared to exert the greatest impact on nanoflagellates. In the cascading experiments, the data suggest that mesozooplankton consume nanoflagellates, which resulted in a decrease in the predation impact of these organisms on the bacteria. This result is consistent with predator-prey cascades. The presence of the larger heterotrophs therefore, mediates the interactions between the primary bacterivores, the nanoflagellates, and the bacteria within the temporarily open/closed East Kleinemonde Estuary.
- Full Text:
- Date Issued: 2008
- Authors: Allan, Elizabeth Louise
- Date: 2008
- Subjects: Bacterial growth -- South Africa -- Eastern Cape , Estuarine ecology -- South Africa -- Eastern Cape , Estuaries -- South Africa -- Eastern Cape , Microbial ecology -- South Africa -- Eastern Cape , Nutrient cycles -- South Africa -- Eastern Cape , Food chains (Ecology)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5666 , http://hdl.handle.net/10962/d1005351 , Bacterial growth -- South Africa -- Eastern Cape , Estuarine ecology -- South Africa -- Eastern Cape , Estuaries -- South Africa -- Eastern Cape , Microbial ecology -- South Africa -- Eastern Cape , Nutrient cycles -- South Africa -- Eastern Cape , Food chains (Ecology)
- Description: The main aim of this study was to assess the “top-down” and “bottom-up” control of bacterial production in the small temporarily open/closed East Kleinemonde Estuary, situated on the south-eastern coastline of southern Africa. Spatial and temporal patterns in bacterial abundance, biomass and production and the importance of abiotic and biotic factors were investigated over the period May 2006 to April 2007. The trophic interactions between bacteria, phytoplankton, nanoflagellates (< 20 μm), microzooplankton (< 200 μm) and mesozooplankton (< 2 000 μm) were investigated during winter and summer. Bacterial abundance, biomass and production ranged between 1.00 × 10⁹ and 4.93 × 10⁹ cells 1⁻¹, 32.4 and 109 μg C 1⁻¹ and 0.01 and 1.99 μg C 1⁻¹ h⁻¹, respectively. With a few exceptions there were no spatial patterns in the values. Bacterial abundance, biomass and production, however, demonstrated a distinct temporal pattern with the lowest values consistently recorded during the winter months. Nanoflagellate and bacterial abundances were significantly correlated to one another (lower reaches: r = 0.818, p < 0.001; middle reaches: r = 0.628, p < 0.001; upper reaches: r = 0.484, p < 0.05) suggesting a strong predator-prey relationship. The frequency of visibly infected bacterial cells and the mean number of virus particles within each bacterial cell during this study demonstrated no temporal or spatial patterns and ranged from 0.5 to 6.1 % and 12.0 to 37.5 virus particles per bacterium, respectively. Viral infection and lysis was thus a constant source of bacterial mortality throughout the year. The estimated percentage of bacterial production removed by viral lysis ranged between 7.8 and 88.9% of the total which suggests that viral lysis represented a very important source of bacterial mortality during this study. The biological interactions between the selected components of the plankton community demonstrated that among the heterotrophic components of the plankton, the nanoflagellates were identified as the most important consumers of bacteria and small phytoplankton cells (< 20 μm). In the presence of microzooplankton the impact of the nanoflagellates on both the bacteria and phytoplankton was reduced, indicating that larger heterotrophs were preying upon the nanoflagellates. Mesozooplankton, however, appeared to exert the greatest impact on nanoflagellates. In the cascading experiments, the data suggest that mesozooplankton consume nanoflagellates, which resulted in a decrease in the predation impact of these organisms on the bacteria. This result is consistent with predator-prey cascades. The presence of the larger heterotrophs therefore, mediates the interactions between the primary bacterivores, the nanoflagellates, and the bacteria within the temporarily open/closed East Kleinemonde Estuary.
- Full Text:
- Date Issued: 2008
Ecological thinking: Schopenhauer, J M Coetzee and who we are in the world
- Authors: Wright, Laurence
- Date: 2008
- Language: English
- Type: text , article
- Identifier: vital:7031 , http://hdl.handle.net/10962/d1007362 , https://doi.org/10.5848/CSP.0926.00001
- Description: preprint , For the ecological agenda to make substantive progress, we will have to see powerful people and social agencies turning away from the ecological insanity that threatens us all, and for this to happen, people need to embrace voluntary renunciation, on the understanding that this is not self-sacrifice, but a different and more satisfying way of being in the world. The paper offers some thought, provoked by reading J.M. Coetzee and Arthur Schopenhauer, about what would make this change possible, what might enable it; and secondly why it is implausible that any such ideal might actually come to pass.
- Full Text:
- Date Issued: 2008
- Authors: Wright, Laurence
- Date: 2008
- Language: English
- Type: text , article
- Identifier: vital:7031 , http://hdl.handle.net/10962/d1007362 , https://doi.org/10.5848/CSP.0926.00001
- Description: preprint , For the ecological agenda to make substantive progress, we will have to see powerful people and social agencies turning away from the ecological insanity that threatens us all, and for this to happen, people need to embrace voluntary renunciation, on the understanding that this is not self-sacrifice, but a different and more satisfying way of being in the world. The paper offers some thought, provoked by reading J.M. Coetzee and Arthur Schopenhauer, about what would make this change possible, what might enable it; and secondly why it is implausible that any such ideal might actually come to pass.
- Full Text:
- Date Issued: 2008
Economic valuation of communal rangelands in the Eastern Cape Province of South Africa
- Authors: Gombakomba, Gift
- Date: 2008
- Subjects: Rangelands -- South Africa -- Eastern Cape -- Evaluation , Rural development -- South Africa -- Eastern Cape -- Evaluation , Commons -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Agricultural Economics)
- Identifier: vital:11166 , http://hdl.handle.net/10353/351 , Rangelands -- South Africa -- Eastern Cape -- Evaluation , Rural development -- South Africa -- Eastern Cape -- Evaluation , Commons -- South Africa -- Eastern Cape
- Description: The exploitation and conversion of rangeland ecosystems is often explained by economists as being the result of an undervaluation of the goods and services provided by the rangelands. Undervaluation of rangelands may contribute to their mismanagement or their transformation to monoculture, such as livestock or gathering. Similarly, this may lead to inappropriate policy recommendations and prescriptions. This study undertakes a valuation exercise in an effort to address causes of undervaluation. The objective of the study is to estimate the annual direct, indirect and non-use values per household of communal rangelands in the Eastern Cape Province, based on both primary and secondary data. The exercise incorporates the two major direct uses, both marketed and non-marketed, of rangelands - livestock and gathering. Contingent valuation method based on stated preferences by individual household was used to value the indirect and non-use values of the communal rangelands (e.g. erosion protection and burial sites). Data was collected using PRAs, structured questionnaires and interviews by trained enumerators. The study shows that half of the households owned livestock, which is the main economic use of the rangelands and gathering of natural resources also made an economic contribution. Every household was involved in collection of range resources such as fuel wood, wild fruits, thatch grass, building poles, hunting, fishing make a significant contribution to the direct use values: in the case of gathering it shows that there is “hidden harvest” of many of the natural resources from the rangelands. Indirect and non-use values are shown to be important in the communal areas but are difficult to quantify; the results of these are based on qualitative analysis. Keywords: communal rangelands, demand curve, direct use values, indirect use values, individuals’ preferences, non-use values, willingness-to-accept and willingness-to-pay.
- Full Text:
- Date Issued: 2008
- Authors: Gombakomba, Gift
- Date: 2008
- Subjects: Rangelands -- South Africa -- Eastern Cape -- Evaluation , Rural development -- South Africa -- Eastern Cape -- Evaluation , Commons -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Agricultural Economics)
- Identifier: vital:11166 , http://hdl.handle.net/10353/351 , Rangelands -- South Africa -- Eastern Cape -- Evaluation , Rural development -- South Africa -- Eastern Cape -- Evaluation , Commons -- South Africa -- Eastern Cape
- Description: The exploitation and conversion of rangeland ecosystems is often explained by economists as being the result of an undervaluation of the goods and services provided by the rangelands. Undervaluation of rangelands may contribute to their mismanagement or their transformation to monoculture, such as livestock or gathering. Similarly, this may lead to inappropriate policy recommendations and prescriptions. This study undertakes a valuation exercise in an effort to address causes of undervaluation. The objective of the study is to estimate the annual direct, indirect and non-use values per household of communal rangelands in the Eastern Cape Province, based on both primary and secondary data. The exercise incorporates the two major direct uses, both marketed and non-marketed, of rangelands - livestock and gathering. Contingent valuation method based on stated preferences by individual household was used to value the indirect and non-use values of the communal rangelands (e.g. erosion protection and burial sites). Data was collected using PRAs, structured questionnaires and interviews by trained enumerators. The study shows that half of the households owned livestock, which is the main economic use of the rangelands and gathering of natural resources also made an economic contribution. Every household was involved in collection of range resources such as fuel wood, wild fruits, thatch grass, building poles, hunting, fishing make a significant contribution to the direct use values: in the case of gathering it shows that there is “hidden harvest” of many of the natural resources from the rangelands. Indirect and non-use values are shown to be important in the communal areas but are difficult to quantify; the results of these are based on qualitative analysis. Keywords: communal rangelands, demand curve, direct use values, indirect use values, individuals’ preferences, non-use values, willingness-to-accept and willingness-to-pay.
- Full Text:
- Date Issued: 2008
Ectomycorrhizas in association with Pinus patula in Sabie, South Africa
- Hawley, Greer L, Taylor, A F S, Dames, Joanna F
- Authors: Hawley, Greer L , Taylor, A F S , Dames, Joanna F
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6475 , http://hdl.handle.net/10962/d1006163 , http://www.scielo.org.za/scielo.php?pid=S0038-23532008000400011&script=sci_arttext
- Description: Forestry is an economically important industry in South Africa,involving extensive exotic plantations of Eucalyptus, Pinus and Acacia species. These tree species have fungal associations, such as ectomycorrhizas, that have become locally naturalized. The forestry industry is increasingly faced with problems of long-term sustainability, increasing soil acidity and depletion of soil nutrients. It is, therefore, essential that the fundamental importance of the ectomycorrhizal (ECM) symbioses in the nutrient cycling, growth, health and survival of these tree species should not be ignored. Research on the species diversity of ECM fungi associated with forestry plant species has been hampered by the difficulty of identifying the fungi involved in the symbiosis. This investigation focused on the ECM fungi associated with Pinus patula (Schlecht. et Cham.) grown in managed plantations in the Sabie region, Mpumalanga province, South Africa. ECM roots were morphotyped and DNA was extracted. The internal transcribed spacer (ITS) region was amplified using the ITS 1F and ITS 4 primers. The sequences were BLASTed using the GenBank and UNITE databases. Twenty-seven extractions were successfully amplified representing 17 different morphotypes. Of the 27 sequences, 21 were identified as ECM fungi and, from the BLAST results, eleven different ECM species could be identified. Selected ECM root types were morphologically and anatomically described according to root morphology, mantle structure, specialized hyphae and rhizomorph arrangement. Seven dominant field types were described and identified as two Amanita species, Scleroderma citrinum, a suilloid species, Thelephora terrestris, a tometelloid species and one resembled an Albatrellus species.
- Full Text:
- Date Issued: 2008
- Authors: Hawley, Greer L , Taylor, A F S , Dames, Joanna F
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6475 , http://hdl.handle.net/10962/d1006163 , http://www.scielo.org.za/scielo.php?pid=S0038-23532008000400011&script=sci_arttext
- Description: Forestry is an economically important industry in South Africa,involving extensive exotic plantations of Eucalyptus, Pinus and Acacia species. These tree species have fungal associations, such as ectomycorrhizas, that have become locally naturalized. The forestry industry is increasingly faced with problems of long-term sustainability, increasing soil acidity and depletion of soil nutrients. It is, therefore, essential that the fundamental importance of the ectomycorrhizal (ECM) symbioses in the nutrient cycling, growth, health and survival of these tree species should not be ignored. Research on the species diversity of ECM fungi associated with forestry plant species has been hampered by the difficulty of identifying the fungi involved in the symbiosis. This investigation focused on the ECM fungi associated with Pinus patula (Schlecht. et Cham.) grown in managed plantations in the Sabie region, Mpumalanga province, South Africa. ECM roots were morphotyped and DNA was extracted. The internal transcribed spacer (ITS) region was amplified using the ITS 1F and ITS 4 primers. The sequences were BLASTed using the GenBank and UNITE databases. Twenty-seven extractions were successfully amplified representing 17 different morphotypes. Of the 27 sequences, 21 were identified as ECM fungi and, from the BLAST results, eleven different ECM species could be identified. Selected ECM root types were morphologically and anatomically described according to root morphology, mantle structure, specialized hyphae and rhizomorph arrangement. Seven dominant field types were described and identified as two Amanita species, Scleroderma citrinum, a suilloid species, Thelephora terrestris, a tometelloid species and one resembled an Albatrellus species.
- Full Text:
- Date Issued: 2008
Editorial: authorship and responsibility [African Entomology]
- Authors: Villet, Martin H
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6851 , http://hdl.handle.net/10962/d1011132
- Description: Editorial service is a privilege in many senses: editors have a much broader view of disciplinary practices than most of their colleagues; they see work from more institutions; and are privy to manuscripts in all states of fitness for publication. The spectrum of practice is eye-opening, and editors are placed in a position of stewardship, and often mentorship, that inevitably focuses attention on quality assurance and ethics (Lawrence 2003; Bulger 2004; Grieger 2005; Graf et al. 2007). Recently, the Committee on Scholarly Publishing in South Africa, a body within the Academy of Science of South Africa (ASSAf), has drafted Guidelines for best practice in editorial discretion and peer review for South African scholarly journals to assist editors.
- Full Text:
- Date Issued: 2008
- Authors: Villet, Martin H
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6851 , http://hdl.handle.net/10962/d1011132
- Description: Editorial service is a privilege in many senses: editors have a much broader view of disciplinary practices than most of their colleagues; they see work from more institutions; and are privy to manuscripts in all states of fitness for publication. The spectrum of practice is eye-opening, and editors are placed in a position of stewardship, and often mentorship, that inevitably focuses attention on quality assurance and ethics (Lawrence 2003; Bulger 2004; Grieger 2005; Graf et al. 2007). Recently, the Committee on Scholarly Publishing in South Africa, a body within the Academy of Science of South Africa (ASSAf), has drafted Guidelines for best practice in editorial discretion and peer review for South African scholarly journals to assist editors.
- Full Text:
- Date Issued: 2008