An investigation of enabling and constraining factors affecting the supply and demand of specific biodiversity scarce skills to the biodiversity sector
- Authors: Mckrill, Leanne Joy
- Date: 2015
- Subjects: Rhodes University , GreenMatter (South Africa) , CATHSSETA (South Africa) , Labor demand -- South Africa , Biodiversity conservation -- Employees -- Supply and demand -- South Africa , Wildlife veterinarians -- Supply and demand -- South Africa , Freshwater ecology -- Employees -- Supply and demand -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:2067 , http://hdl.handle.net/10962/d1020837
- Description: This study is situated within the context of the emerging South African Biodiversity Sector and focuses on the supply of and demand for scarce skilled biodiversity professionals. It does so through investigating the transition a young biodiversity professional makes from a higher education institution to the workplace by drawing attention to the factors encountered or perceived to be encountered during this development. The study forms part of a research programme established between Rhodes University, GreenMatter and the Culture Arts Tourism Hospitality Sport Education and Training Authority (CATHSSETA), which seeks to contribute to the body of knowledge pertaining to "green" skills development and retention within the South African biodiversity sector. It is a qualitative study, comprising nested case studies within two larger case studies of scarce skills – those of wildlife veterinarians and freshwater ecologists – as identified by the biodiversity priority scarce skills list (SANBI & Lewis Foundation, 2012). The study is supported by Bronfenbrenner's (1979) Ecological Systems theory and underpinned by the principles of basic critical realism and emergence (Archer, Bhaskar, Collier, Lawson, & Norrie, 1998). Data was generated through a range of data collection methods, including semi-structured interviews, participant observation and document analysis. The aim of these methods was to enable a greater understanding of the factors influencing transitioning and the unique transitions of selected individuals. Findings revealed that the transitions of the participants, although unique to each of them, included the following commonalities: exposure to biodiversity at an early stage in an individual's life paved the way for the development and nurturing of an interest or passion in biodiversity; experience gained prior to entry into the workplace is a powerful enabling factor; the presence or absence of a mentor can be pivotal in the transition of an individual; the gap in knowledge pertaining to demand side or workplace information is a large constraining factor; workplace dynamics affect the demand for, and eventual supply of, biodiversity professionals; the presence of human capital development strategies and structures is beneficial to the individual's transition, and the overall ecosystemic development of an individual has an effect on the supply of specific scarce-skilled individuals to the workforce. This study demonstrates that through the employment of nested case studies, similar research focussing on other scarce skills within the biodiversity sector, as per the GreenMatter Priority Skills List of 2012, can be produced, which would help to address the knowledge gaps pertaining to scarce skills, as indicated by the Biodiversity Human Capital Development Strategy (2010).
- Full Text:
- Authors: Mckrill, Leanne Joy
- Date: 2015
- Subjects: Rhodes University , GreenMatter (South Africa) , CATHSSETA (South Africa) , Labor demand -- South Africa , Biodiversity conservation -- Employees -- Supply and demand -- South Africa , Wildlife veterinarians -- Supply and demand -- South Africa , Freshwater ecology -- Employees -- Supply and demand -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:2067 , http://hdl.handle.net/10962/d1020837
- Description: This study is situated within the context of the emerging South African Biodiversity Sector and focuses on the supply of and demand for scarce skilled biodiversity professionals. It does so through investigating the transition a young biodiversity professional makes from a higher education institution to the workplace by drawing attention to the factors encountered or perceived to be encountered during this development. The study forms part of a research programme established between Rhodes University, GreenMatter and the Culture Arts Tourism Hospitality Sport Education and Training Authority (CATHSSETA), which seeks to contribute to the body of knowledge pertaining to "green" skills development and retention within the South African biodiversity sector. It is a qualitative study, comprising nested case studies within two larger case studies of scarce skills – those of wildlife veterinarians and freshwater ecologists – as identified by the biodiversity priority scarce skills list (SANBI & Lewis Foundation, 2012). The study is supported by Bronfenbrenner's (1979) Ecological Systems theory and underpinned by the principles of basic critical realism and emergence (Archer, Bhaskar, Collier, Lawson, & Norrie, 1998). Data was generated through a range of data collection methods, including semi-structured interviews, participant observation and document analysis. The aim of these methods was to enable a greater understanding of the factors influencing transitioning and the unique transitions of selected individuals. Findings revealed that the transitions of the participants, although unique to each of them, included the following commonalities: exposure to biodiversity at an early stage in an individual's life paved the way for the development and nurturing of an interest or passion in biodiversity; experience gained prior to entry into the workplace is a powerful enabling factor; the presence or absence of a mentor can be pivotal in the transition of an individual; the gap in knowledge pertaining to demand side or workplace information is a large constraining factor; workplace dynamics affect the demand for, and eventual supply of, biodiversity professionals; the presence of human capital development strategies and structures is beneficial to the individual's transition, and the overall ecosystemic development of an individual has an effect on the supply of specific scarce-skilled individuals to the workforce. This study demonstrates that through the employment of nested case studies, similar research focussing on other scarce skills within the biodiversity sector, as per the GreenMatter Priority Skills List of 2012, can be produced, which would help to address the knowledge gaps pertaining to scarce skills, as indicated by the Biodiversity Human Capital Development Strategy (2010).
- Full Text:
An investigation of ISO/IEC 27001 adoption in South Africa
- Authors: Coetzer, Christo
- Date: 2015
- Subjects: ISO 27001 Standard , Information technology -- Security measures , Computer security , Data protection
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4720 , http://hdl.handle.net/10962/d1018669
- Description: The research objective of this study is to investigate the low adoption of the ISO/IEC 27001 standard in South African organisations. This study does not differentiate between the ISO/IEC 27001:2005 and ISO/IEC 27001:2013 versions, as the focus is on adoption of the ISO/IEC 27001 standard. A survey-based research design was selected as the data collection method. The research instruments used in this study include a web-based questionnaire and in-person interviews with the participants. Based on the findings of this research, the organisations that participated in this study have an understanding of the ISO/IEC 27001 standard; however, fewer than a quarter of these have fully adopted the ISO/IEC 27001 standard. Furthermore, the main business objectives for organisations that have adopted the ISO/IEC 27001 standard were to ensure legal and regulatory compliance, and to fulfil client requirements. An Information Security Management System management guide based on the ISO/IEC 27001 Plan-Do-Check-Act model is developed to help organisations interested in the standard move towards ISO/IEC 27001 compliance.
- Full Text:
- Authors: Coetzer, Christo
- Date: 2015
- Subjects: ISO 27001 Standard , Information technology -- Security measures , Computer security , Data protection
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4720 , http://hdl.handle.net/10962/d1018669
- Description: The research objective of this study is to investigate the low adoption of the ISO/IEC 27001 standard in South African organisations. This study does not differentiate between the ISO/IEC 27001:2005 and ISO/IEC 27001:2013 versions, as the focus is on adoption of the ISO/IEC 27001 standard. A survey-based research design was selected as the data collection method. The research instruments used in this study include a web-based questionnaire and in-person interviews with the participants. Based on the findings of this research, the organisations that participated in this study have an understanding of the ISO/IEC 27001 standard; however, fewer than a quarter of these have fully adopted the ISO/IEC 27001 standard. Furthermore, the main business objectives for organisations that have adopted the ISO/IEC 27001 standard were to ensure legal and regulatory compliance, and to fulfil client requirements. An Information Security Management System management guide based on the ISO/IEC 27001 Plan-Do-Check-Act model is developed to help organisations interested in the standard move towards ISO/IEC 27001 compliance.
- Full Text:
An investigation of socio-ecological issues and risks and capabilities in the 'my future is my choice' HIV and AIDS programme : a case in northern Namibia
- Authors: Tjiveze, Wakaa
- Date: 2015
- Subjects: My Future is My Choice (Program : Namibia) , HIV infections -- Social aspects -- Namibia , AIDS (Disease) -- Social aspects -- Namibia , AIDS (Disease) -- Study and teaching -- Namibia , AIDS (Disease) -- Risk factors -- Namibia , AIDS (Disease) -- Moral and ethical aspects -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:2050 , http://hdl.handle.net/10962/d1017769
- Description: The HIV and AIDS crisis can be presented as a socio-ecological issue, with an ever-increasing impact on both human beings and the environment. Teaching about socio-ecological issues and the consideration of individual capabilities has become crucial within HIV and AIDS education programmes. Issues of deforestation, land degradation and other environmental problems have worsened since the advent of HIV and AIDS, especially in developing countries. The My Future is My Choice (MFMC) programme has been identified as an important HIV and AIDS education initiative that caters for young people in Namibian secondary schools (Grades 8-12). One of the themes within the programme (Facing HIV and AIDS) is highlighted in this study. This study was constituted as a case study of one school in rural Omuthiya, in the Oshikoto region. The study investigated the opportunities for the integration of a focus on socio-ecological issues and risks, within the MFMC education programme. The study also investigated the way in which the program develops learners‟ capabilities to respond to HIV and AIDS related socio-ecological issues and risks/vulnerabilities. The study also presents the constraints and enabling factors influencing the implementation of the programme. This study used a qualitative, interpretive case study methodology. The research methods included the analysis of eight documents and nineteen semi-structured interviews, with the Programme Coordinator, the Programme Facilitator, the School Principal and with the programme participants. The analysis also included two focus group discussions with a group of learners; and two classroom observations; and the learners' submissions (reflection sheets). Convenience sampling was used, and ethical issues were taken into consideration throughout the study. The study revealed the following as key findings: The aims and objectives of the HIV and AIDS education programme can enhance and constrain the development of capabilities, as well as opportunities and challenges for the integration of a focus on socio-environmental issues and risks as additional learning content. Teaching and learning methods that are participatory and rooted within the learner centered approach can make the integration of HIV and AIDS inherent socio-environmental issues and risks into the MFMC education programme possible. The values and beliefs inherent within the MFMC education programme stand as opportunities for the successful development of capabilities in the education programme. The study concluded by recommending that capabilities within the MFMC programme be developed through teaching learners about their rights, respect for human dignity, and the right to health and to living the life free from discriminatory practices, as a moral entitlement of each and every individual. While teaching learners about their right to health and the importance of healthy diets, this study found that the programme could include learning about food production and handling practices for the benefit of those living with HIV and AIDS, while caring for the environment. Another recommendation was that future research should consider actively involving young people in decision-making with regard to the programme, as this will allow them to choose and decide on what knowledge and skills they need and want to acquire. The study further explained that this will promote the programme participants‟ sense of agency, and their freedom to choose what they value being and doing as an important element in enhancing learner capabilities. Ultimately, this will also enable the learners to acquire the necessary skills and knowledge they need in order to respond to the socio-ecological problems they face in their communities.
- Full Text:
- Authors: Tjiveze, Wakaa
- Date: 2015
- Subjects: My Future is My Choice (Program : Namibia) , HIV infections -- Social aspects -- Namibia , AIDS (Disease) -- Social aspects -- Namibia , AIDS (Disease) -- Study and teaching -- Namibia , AIDS (Disease) -- Risk factors -- Namibia , AIDS (Disease) -- Moral and ethical aspects -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:2050 , http://hdl.handle.net/10962/d1017769
- Description: The HIV and AIDS crisis can be presented as a socio-ecological issue, with an ever-increasing impact on both human beings and the environment. Teaching about socio-ecological issues and the consideration of individual capabilities has become crucial within HIV and AIDS education programmes. Issues of deforestation, land degradation and other environmental problems have worsened since the advent of HIV and AIDS, especially in developing countries. The My Future is My Choice (MFMC) programme has been identified as an important HIV and AIDS education initiative that caters for young people in Namibian secondary schools (Grades 8-12). One of the themes within the programme (Facing HIV and AIDS) is highlighted in this study. This study was constituted as a case study of one school in rural Omuthiya, in the Oshikoto region. The study investigated the opportunities for the integration of a focus on socio-ecological issues and risks, within the MFMC education programme. The study also investigated the way in which the program develops learners‟ capabilities to respond to HIV and AIDS related socio-ecological issues and risks/vulnerabilities. The study also presents the constraints and enabling factors influencing the implementation of the programme. This study used a qualitative, interpretive case study methodology. The research methods included the analysis of eight documents and nineteen semi-structured interviews, with the Programme Coordinator, the Programme Facilitator, the School Principal and with the programme participants. The analysis also included two focus group discussions with a group of learners; and two classroom observations; and the learners' submissions (reflection sheets). Convenience sampling was used, and ethical issues were taken into consideration throughout the study. The study revealed the following as key findings: The aims and objectives of the HIV and AIDS education programme can enhance and constrain the development of capabilities, as well as opportunities and challenges for the integration of a focus on socio-environmental issues and risks as additional learning content. Teaching and learning methods that are participatory and rooted within the learner centered approach can make the integration of HIV and AIDS inherent socio-environmental issues and risks into the MFMC education programme possible. The values and beliefs inherent within the MFMC education programme stand as opportunities for the successful development of capabilities in the education programme. The study concluded by recommending that capabilities within the MFMC programme be developed through teaching learners about their rights, respect for human dignity, and the right to health and to living the life free from discriminatory practices, as a moral entitlement of each and every individual. While teaching learners about their right to health and the importance of healthy diets, this study found that the programme could include learning about food production and handling practices for the benefit of those living with HIV and AIDS, while caring for the environment. Another recommendation was that future research should consider actively involving young people in decision-making with regard to the programme, as this will allow them to choose and decide on what knowledge and skills they need and want to acquire. The study further explained that this will promote the programme participants‟ sense of agency, and their freedom to choose what they value being and doing as an important element in enhancing learner capabilities. Ultimately, this will also enable the learners to acquire the necessary skills and knowledge they need in order to respond to the socio-ecological problems they face in their communities.
- Full Text:
An overview of energy minerals in the Springbok Flatsbasin, South Africa : implications for geochemical and geophysical exploration
- Authors: Ledwaba, Lebogang John
- Date: 2015
- Subjects: Energy minerals -- South Africa -- Springbok Flats (Limpopo) , Geochemistry , Prospecting -- Geophysical methods , Coal -- South Africa -- Springbok Flats (Limpopo) , Uranium -- South Africa -- Springbok Flats (Limpopo) , Coalbed methane -- South Africa -- Springbok Flats (Limpopo)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5092 , http://hdl.handle.net/10962/d1019880
- Description: This study is informed by the rising demand for power needs in South Africa and aims at understanding the geophysical and geochemical characteristics of the energy minerals in the Springbok Flats Basin and relating them to the prevailing geological and structural setting for improved exploration targeting. The Springbok Flats Basin is part of the Karoo sediments and host to uranium, coal and coal bed methane (CBM) resources. The lithology sections in the basin indicate presence of basaltic lavas at the top, underlain by mudrocks, siltstones, sandstones, conglomerates and diamictite, with interbedded coal beds occasionally. The coals are uraniferous and shale bounded and of lower Beaufort age at 250 Ma. The regional radiometric data identifies the regional extent of the Springbok Flats Basin as a basin with low total count values. This information is useful in exploration as it gives an idea of the limits of the area where to focus application for prospecting licenses. The reduced to pole of the total magnetic field, residuals and first vertical derivative maps clearly show the high magnetic susceptibility nature of the surrounding Bushveld rocks as compared to the low Karoo sediment susceptibility within the basin. There are distinct ring shaped picks within the basin possibly due to known Karoo dolerite sills in particular to the central south western part of the grid. The regional geochemical mapping program is a cost-effective way of providing an overview of the relative abundance levels, regional trends and anomalous patterns in the underlying lithological units. Background values of elements in soils over different lithological units and the identification of anomalous values relative to these elements can easily be identified. The geochemical results show an excellent correlation between soil chemistry and underlying geological formations. A few distinct gravity highs are clearly shown within the basin. Assuming the effect of the Letaba basalt to the gravity readings is uniform across the basin; these distinct anomalies could be due to Karoo dolerite sills as they coincide with areas of distinct high magnetic signature. A conceptual model was generated assuming that the Karoo sediments’ layering is uniform across the gravity profile but changes in the residual are due to an increased thickness of the sill supported by the gentle changes on the surface topography. Satellite imagery has got its challenges especially in areas of vegetation but it does provide a very useful tool in exploration. A number of spectral analysis techniques and band rations can be used to differentiate the areas underlain by the Letaba basalts, the Karoo sandstones/shale and Bushveld granites for mapping purposes. The priority focus will be on the shallower Karoo sediments because of the potential for cheaper mining. Exploration targeting needs to be guided by observed geochemical and geophysical characteristics in order to prioritize areas taking into account the presence of Karoo intrusives such as the dolerite sills that tend to devolatize the coal hence affecting the quality/rank. Structures and gravity signatures are very important in delineating areas with thick sediments that have a potential for CBM. The same understanding in targeting goes a long way in planning drill holes, resource modelling and pre-feasibility stages for mine planning. A high resolution airborne geophysical survey is recommended over the basin to better resolve structures. Geophysical borehole logging is recommended to be part of the exploration drilling programs in the Springbok Flats Basin in order to define the in-situ geophysical characteristics. Geophysical logging is useful in particular for the uranium reserves that cannot be delineated from the surface due to deep intersection.
- Full Text:
- Authors: Ledwaba, Lebogang John
- Date: 2015
- Subjects: Energy minerals -- South Africa -- Springbok Flats (Limpopo) , Geochemistry , Prospecting -- Geophysical methods , Coal -- South Africa -- Springbok Flats (Limpopo) , Uranium -- South Africa -- Springbok Flats (Limpopo) , Coalbed methane -- South Africa -- Springbok Flats (Limpopo)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5092 , http://hdl.handle.net/10962/d1019880
- Description: This study is informed by the rising demand for power needs in South Africa and aims at understanding the geophysical and geochemical characteristics of the energy minerals in the Springbok Flats Basin and relating them to the prevailing geological and structural setting for improved exploration targeting. The Springbok Flats Basin is part of the Karoo sediments and host to uranium, coal and coal bed methane (CBM) resources. The lithology sections in the basin indicate presence of basaltic lavas at the top, underlain by mudrocks, siltstones, sandstones, conglomerates and diamictite, with interbedded coal beds occasionally. The coals are uraniferous and shale bounded and of lower Beaufort age at 250 Ma. The regional radiometric data identifies the regional extent of the Springbok Flats Basin as a basin with low total count values. This information is useful in exploration as it gives an idea of the limits of the area where to focus application for prospecting licenses. The reduced to pole of the total magnetic field, residuals and first vertical derivative maps clearly show the high magnetic susceptibility nature of the surrounding Bushveld rocks as compared to the low Karoo sediment susceptibility within the basin. There are distinct ring shaped picks within the basin possibly due to known Karoo dolerite sills in particular to the central south western part of the grid. The regional geochemical mapping program is a cost-effective way of providing an overview of the relative abundance levels, regional trends and anomalous patterns in the underlying lithological units. Background values of elements in soils over different lithological units and the identification of anomalous values relative to these elements can easily be identified. The geochemical results show an excellent correlation between soil chemistry and underlying geological formations. A few distinct gravity highs are clearly shown within the basin. Assuming the effect of the Letaba basalt to the gravity readings is uniform across the basin; these distinct anomalies could be due to Karoo dolerite sills as they coincide with areas of distinct high magnetic signature. A conceptual model was generated assuming that the Karoo sediments’ layering is uniform across the gravity profile but changes in the residual are due to an increased thickness of the sill supported by the gentle changes on the surface topography. Satellite imagery has got its challenges especially in areas of vegetation but it does provide a very useful tool in exploration. A number of spectral analysis techniques and band rations can be used to differentiate the areas underlain by the Letaba basalts, the Karoo sandstones/shale and Bushveld granites for mapping purposes. The priority focus will be on the shallower Karoo sediments because of the potential for cheaper mining. Exploration targeting needs to be guided by observed geochemical and geophysical characteristics in order to prioritize areas taking into account the presence of Karoo intrusives such as the dolerite sills that tend to devolatize the coal hence affecting the quality/rank. Structures and gravity signatures are very important in delineating areas with thick sediments that have a potential for CBM. The same understanding in targeting goes a long way in planning drill holes, resource modelling and pre-feasibility stages for mine planning. A high resolution airborne geophysical survey is recommended over the basin to better resolve structures. Geophysical borehole logging is recommended to be part of the exploration drilling programs in the Springbok Flats Basin in order to define the in-situ geophysical characteristics. Geophysical logging is useful in particular for the uranium reserves that cannot be delineated from the surface due to deep intersection.
- Full Text:
Analysing from experience : Gustav Mahler’s Quartetsatz for piano and strings
- Authors: Du Plessis, Jacques
- Date: 2015
- Subjects: Mahler, Gustav, 1860-1911. -- Quartet, piano, violin, viola, cello, A minor , Musical analysis , Music appreciation , Phenomenology and music
- Language: English
- Type: Thesis , Masters , MMus
- Identifier: vital:2696 , http://hdl.handle.net/10962/d1017818
- Description: Musical analysis has traditionally been located within the context of musicology. It is therefore an activity usually considered the purview of music scholars rather than practical musicians. The musical analyses produced by music scholars therefore provide us with intellectual understandings of musical works, rather than insights into the experience of listening to or playing music. In this thesis, I will propose that those agents involved in practical music-making can produce insights into musical works that are as valid as the work of traditional music scholarship. I will attempt to re-conceptualize the position of the ‘knower’ or ‘experiencer’ - the performer - of music as one with primary access to knowledge of a musical work, and therefore ideally suited to offer analyses of these works. The establishment of the performer as a bearer of central analytical knowledge functions in direct opposition to the traditional distinction between ‘theory’ and ‘practice’. My thesis will trace the Platonic origins of the philosophical separation of practice and research, and as an alternative to the traditional separation of practice and research, I shall explore the concept of Practice-Based Research (PBR). My exploration of PBR will be informed by phenomenological approaches to music scholarship. As a field of enquiry which concerns itself with experience, the phenomenology of music suggests that the mind and body of the practitioner are important sources of musical insight. To address this issue, Bourdieu’s notion of habitus will be explored. The habitus will be shown to contain a vast network of socio-cultural codes informing the practitioner’s relationship with the musical work. A central aim of this thesis is to explore the possibilities of using practice-based research as the foundation for the study and analysis of a composition, in order to allow for a deeper understanding of the work by means of the generation and harnessing of practical knowledge. Thus, the theoretical outline of PBR provided in this thesis will be applied to a piece of practical performance-based analysis. As such, an analysis of Mahler’s Quartetsatz will be used as the basis on which to draw knowledge in this project.
- Full Text:
- Authors: Du Plessis, Jacques
- Date: 2015
- Subjects: Mahler, Gustav, 1860-1911. -- Quartet, piano, violin, viola, cello, A minor , Musical analysis , Music appreciation , Phenomenology and music
- Language: English
- Type: Thesis , Masters , MMus
- Identifier: vital:2696 , http://hdl.handle.net/10962/d1017818
- Description: Musical analysis has traditionally been located within the context of musicology. It is therefore an activity usually considered the purview of music scholars rather than practical musicians. The musical analyses produced by music scholars therefore provide us with intellectual understandings of musical works, rather than insights into the experience of listening to or playing music. In this thesis, I will propose that those agents involved in practical music-making can produce insights into musical works that are as valid as the work of traditional music scholarship. I will attempt to re-conceptualize the position of the ‘knower’ or ‘experiencer’ - the performer - of music as one with primary access to knowledge of a musical work, and therefore ideally suited to offer analyses of these works. The establishment of the performer as a bearer of central analytical knowledge functions in direct opposition to the traditional distinction between ‘theory’ and ‘practice’. My thesis will trace the Platonic origins of the philosophical separation of practice and research, and as an alternative to the traditional separation of practice and research, I shall explore the concept of Practice-Based Research (PBR). My exploration of PBR will be informed by phenomenological approaches to music scholarship. As a field of enquiry which concerns itself with experience, the phenomenology of music suggests that the mind and body of the practitioner are important sources of musical insight. To address this issue, Bourdieu’s notion of habitus will be explored. The habitus will be shown to contain a vast network of socio-cultural codes informing the practitioner’s relationship with the musical work. A central aim of this thesis is to explore the possibilities of using practice-based research as the foundation for the study and analysis of a composition, in order to allow for a deeper understanding of the work by means of the generation and harnessing of practical knowledge. Thus, the theoretical outline of PBR provided in this thesis will be applied to a piece of practical performance-based analysis. As such, an analysis of Mahler’s Quartetsatz will be used as the basis on which to draw knowledge in this project.
- Full Text:
Analysis of predictive power of binding affinity of PBM-derived sequences
- Authors: Matereke, Lavious Tapiwa
- Date: 2015
- Subjects: Transcription factors , Protein binding , DNA-binding proteins , Chromatin , Protein microarrays
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4161 , http://hdl.handle.net/10962/d1018666
- Description: A transcription factor (TF) is a protein that binds to specific DNA sequences as part of the initiation stage of transcription. Various methods of finding these transcription factor binding sites (TFBS) have been developed. In vivo technologies analyze DNA binding regions known to have bound to a TF in a living cell. Most widely used in vivo methods at the moment are chromatin immunoprecipitation followed by deep sequencing (ChIP-seq) and DNase I hypersensitive sites sequencing. In vitro methods derive TFBS based on experiments with TFs and DNA usually in artificial settings or computationally. An example is the Protein Binding Microarray which uses artificially constructed DNA sequences to determine the short sequences that are most likely to bind to a TF. The major drawback of this approach is that binding of TFs in vivo is also dependent on other factors such as chromatin accessibility and the presence of cofactors. Therefore TFBS derived from the PBM technique might not resemble the true DNA binding sequences. In this work, we use PBM data from the UniPROBE motif database, ChIP-seq data and DNase I hypersensitive sites data. Using the Spearman’s rank correlation and area under receiver operating characteristic curve, we compare the enrichment scores which the PBM approach assigns to its identified sequences and the frequency of these sequences in likely binding regions and the human genome as a whole. We also use central motif enrichment analysis (CentriMo) to compare the enrichment of UniPROBE motifs with in vivo derived motifs (from the JASPAR CORE database) in their respective TF ChIP-seq peak region. CentriMo is applied to 14 TF ChIP-seq peak regions from different cell lines. We aim to establish if there is a relationship between the occurrences of UniPROBE 8-mer patterns in likely binding regions and their enrichment score and how well the in vitro derived motifs match in vivo binding specificity. We did not come out with a particular trend showing failure of the PBM approach to predict in vivo binding specificity. Our results show Ets1, Hnf4a and Tcf3 show prediction failure by the PBM technique in terms of our Spearman’s rank correlation for ChIP-seq data and central motif enrichment analysis. However, the PBM technique also matched the in vivo binding specificities of FoxA2, Pou2f2 and Mafk. Failure of the PBM approach was found to be a result of variability in the TF’s binding specificity, the presence of cofactors, narrow binding specificity and the presence ubiquitous binding patterns.
- Full Text:
- Authors: Matereke, Lavious Tapiwa
- Date: 2015
- Subjects: Transcription factors , Protein binding , DNA-binding proteins , Chromatin , Protein microarrays
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4161 , http://hdl.handle.net/10962/d1018666
- Description: A transcription factor (TF) is a protein that binds to specific DNA sequences as part of the initiation stage of transcription. Various methods of finding these transcription factor binding sites (TFBS) have been developed. In vivo technologies analyze DNA binding regions known to have bound to a TF in a living cell. Most widely used in vivo methods at the moment are chromatin immunoprecipitation followed by deep sequencing (ChIP-seq) and DNase I hypersensitive sites sequencing. In vitro methods derive TFBS based on experiments with TFs and DNA usually in artificial settings or computationally. An example is the Protein Binding Microarray which uses artificially constructed DNA sequences to determine the short sequences that are most likely to bind to a TF. The major drawback of this approach is that binding of TFs in vivo is also dependent on other factors such as chromatin accessibility and the presence of cofactors. Therefore TFBS derived from the PBM technique might not resemble the true DNA binding sequences. In this work, we use PBM data from the UniPROBE motif database, ChIP-seq data and DNase I hypersensitive sites data. Using the Spearman’s rank correlation and area under receiver operating characteristic curve, we compare the enrichment scores which the PBM approach assigns to its identified sequences and the frequency of these sequences in likely binding regions and the human genome as a whole. We also use central motif enrichment analysis (CentriMo) to compare the enrichment of UniPROBE motifs with in vivo derived motifs (from the JASPAR CORE database) in their respective TF ChIP-seq peak region. CentriMo is applied to 14 TF ChIP-seq peak regions from different cell lines. We aim to establish if there is a relationship between the occurrences of UniPROBE 8-mer patterns in likely binding regions and their enrichment score and how well the in vitro derived motifs match in vivo binding specificity. We did not come out with a particular trend showing failure of the PBM approach to predict in vivo binding specificity. Our results show Ets1, Hnf4a and Tcf3 show prediction failure by the PBM technique in terms of our Spearman’s rank correlation for ChIP-seq data and central motif enrichment analysis. However, the PBM technique also matched the in vivo binding specificities of FoxA2, Pou2f2 and Mafk. Failure of the PBM approach was found to be a result of variability in the TF’s binding specificity, the presence of cofactors, narrow binding specificity and the presence ubiquitous binding patterns.
- Full Text:
Antjie Krog and the post-apartheid public sphere: Speaking poetry to power
- Authors: Garman, Anthea
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/159913 , vital:40355 , ISBN 978-1869142933
- Description: Antjie Krog has been known in Afrikaans literary circles and the media for decades because of her poetry and her strong political convictions. Often known simply as 'Antjie,' she is also affectionately called 'our beloved poet' and our 'Joan of Arc' by Afrikaans commentators. It was through her work on the Truth and Reconciliation Commission as an SABC radio journalist and her subsequent book, Country of My Skull, that Antjie Krog then became known to English-speakers in South Africa and across the world. Her work catapulted her particular brand of poetics and politics, honed over many years of her opposition to apartheid, into the South African public sphere at a time when the country was not only looking for a humane and just resolution after the apartheid era, but was also establishing itself as a new democracy.
- Full Text:
- Authors: Garman, Anthea
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/159913 , vital:40355 , ISBN 978-1869142933
- Description: Antjie Krog has been known in Afrikaans literary circles and the media for decades because of her poetry and her strong political convictions. Often known simply as 'Antjie,' she is also affectionately called 'our beloved poet' and our 'Joan of Arc' by Afrikaans commentators. It was through her work on the Truth and Reconciliation Commission as an SABC radio journalist and her subsequent book, Country of My Skull, that Antjie Krog then became known to English-speakers in South Africa and across the world. Her work catapulted her particular brand of poetics and politics, honed over many years of her opposition to apartheid, into the South African public sphere at a time when the country was not only looking for a humane and just resolution after the apartheid era, but was also establishing itself as a new democracy.
- Full Text:
Application of Baylis-Hillman methodology in the synthesis of HIV-1 enzyme inhibitors
- Authors: Manyeruke, Meloddy Hlatini
- Date: 2015
- Subjects: HIV infections , Enzyme inhibitors , AZT (Drug) , Bioconjugates
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4540 , http://hdl.handle.net/10962/d1017920
- Description: The application of Baylis-Hillman methodology has afforded access to a range of β-hydroxypropionate ester-AZT conjugates as potential dual-action HIV-1 IN/RT inhibitors. Two families comprising a total of nine β-hydroxypropionate ester-AZT conjugates were synthesised. The first family was accessed using O-benzylated salicylaldehydes and methyl acrylate and the second from unprotected salicylaldehydes using tert-butyl acrylate as the activated alkene. Spectroscopic methods were employed to fully characterize the compounds. Propargylation of the respective Baylis-Hillman adducts was achieved via conjugate addition of propargylamine. The resulting products were then employed in Cu(I)-catalysed “click” reactions with azidothymidine (AZT) to yield the desired β-hydroxypropionate ester-AZT conjugates. Exploratory studies were also conducted to access 4-hydroxycoumarins from Baylis-Hillman derived adducts and to construct customized chiral Baylis-Hillman reaction sites. Many 4- hydroxycoumarins are known to exhibit a wide range of biological activities, and extending Baylis-Hillman methodology to access these systems is an important challenge. Two approaches were investigated. The first involved the formation of a 4-phthalimidocoumarin, aromatisation and hydrolysis of which was expected to lead to the 4-hydroxycoumarin target. The second, a variation of the first, involved the use of 4-(chrolomethyl)coumarin intermediates. Unfortunately, while various intermediates were prepared and characterised, neither approach led ultimately to the desired targets. N-substituted borneol-10-sulfonamides were constructed from camphor-10- sulfonyl chloride as chiral Baylis-Hillman reaction sites. In a preliminary study, however, none of the N-substituted borneol-10-sulfonamides exhibited Baylis-Hillman catalytic activity.
- Full Text:
- Authors: Manyeruke, Meloddy Hlatini
- Date: 2015
- Subjects: HIV infections , Enzyme inhibitors , AZT (Drug) , Bioconjugates
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4540 , http://hdl.handle.net/10962/d1017920
- Description: The application of Baylis-Hillman methodology has afforded access to a range of β-hydroxypropionate ester-AZT conjugates as potential dual-action HIV-1 IN/RT inhibitors. Two families comprising a total of nine β-hydroxypropionate ester-AZT conjugates were synthesised. The first family was accessed using O-benzylated salicylaldehydes and methyl acrylate and the second from unprotected salicylaldehydes using tert-butyl acrylate as the activated alkene. Spectroscopic methods were employed to fully characterize the compounds. Propargylation of the respective Baylis-Hillman adducts was achieved via conjugate addition of propargylamine. The resulting products were then employed in Cu(I)-catalysed “click” reactions with azidothymidine (AZT) to yield the desired β-hydroxypropionate ester-AZT conjugates. Exploratory studies were also conducted to access 4-hydroxycoumarins from Baylis-Hillman derived adducts and to construct customized chiral Baylis-Hillman reaction sites. Many 4- hydroxycoumarins are known to exhibit a wide range of biological activities, and extending Baylis-Hillman methodology to access these systems is an important challenge. Two approaches were investigated. The first involved the formation of a 4-phthalimidocoumarin, aromatisation and hydrolysis of which was expected to lead to the 4-hydroxycoumarin target. The second, a variation of the first, involved the use of 4-(chrolomethyl)coumarin intermediates. Unfortunately, while various intermediates were prepared and characterised, neither approach led ultimately to the desired targets. N-substituted borneol-10-sulfonamides were constructed from camphor-10- sulfonyl chloride as chiral Baylis-Hillman reaction sites. In a preliminary study, however, none of the N-substituted borneol-10-sulfonamides exhibited Baylis-Hillman catalytic activity.
- Full Text:
Applications of social media and web 2.0 for research support in selected African academic institutions
- Owusu-Ansah, Christopher M, Gontshi, Vuyokazi, Mutibwa, Lois, Ukwoma, Scholarstica
- Authors: Owusu-Ansah, Christopher M , Gontshi, Vuyokazi , Mutibwa, Lois , Ukwoma, Scholarstica
- Date: 2015
- Subjects: Social networks , Web 2.0. , Research -- Study and teaching
- Language: English
- Type: Article
- Identifier: vital:6996 , http://hdl.handle.net/10962/d1018520
- Description: This study examined the use of Social Media/Web 2.0 for research support and it is guided by three objectives namely: a) to ascertain the uses of social media in academic institutions; b) to identify the challenges associated with social media use for research purposes and c) to provide experiences of social media application in selected African academic institutions. The study makes use of literature analysis in combination with personal and professional work experiences on the use of social media from librarians in four different countries. Institutional experiences of the four librarians showed that it is only Rhodes University Library that uses social media in its library, which is as a result of a formal social media strategy. For the other three universities, University of Education, Winneba Library in Ghana, Makerere University Library in Uganda and the University of Nigeria Library, the use of social media is not encouraging. They use it mostly for communication and interaction with colleagues. It was also discovered that there is no social media strategy available in these university libraries. Based on these findings, the study recommended the implementation of a social media strategy, appointment of social media librarians in these libraries, and continuing professional development of librarians to keep abreast with current trends. Web 2.0/Social Media is a new technology offering new options for African academic librarians in their research support role
- Full Text:
- Authors: Owusu-Ansah, Christopher M , Gontshi, Vuyokazi , Mutibwa, Lois , Ukwoma, Scholarstica
- Date: 2015
- Subjects: Social networks , Web 2.0. , Research -- Study and teaching
- Language: English
- Type: Article
- Identifier: vital:6996 , http://hdl.handle.net/10962/d1018520
- Description: This study examined the use of Social Media/Web 2.0 for research support and it is guided by three objectives namely: a) to ascertain the uses of social media in academic institutions; b) to identify the challenges associated with social media use for research purposes and c) to provide experiences of social media application in selected African academic institutions. The study makes use of literature analysis in combination with personal and professional work experiences on the use of social media from librarians in four different countries. Institutional experiences of the four librarians showed that it is only Rhodes University Library that uses social media in its library, which is as a result of a formal social media strategy. For the other three universities, University of Education, Winneba Library in Ghana, Makerere University Library in Uganda and the University of Nigeria Library, the use of social media is not encouraging. They use it mostly for communication and interaction with colleagues. It was also discovered that there is no social media strategy available in these university libraries. Based on these findings, the study recommended the implementation of a social media strategy, appointment of social media librarians in these libraries, and continuing professional development of librarians to keep abreast with current trends. Web 2.0/Social Media is a new technology offering new options for African academic librarians in their research support role
- Full Text:
Applied theatre research. Radical departures
- Authors: Sutherland, Alexandra
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/468527 , vital:77087 , https://doi.org/10.1080/10137548.2015.1085255
- Description: This book is part of the Applied Theatre series, which presents scholarship on different foci around applied theatre practices. The seven case studies of how applied theatre practices can be framed as research methodologies are practically and theoretically useful for students, practitioners and scholars engaged in community-driven, socially engaged theatre work. The book argues a particular approach to arts based research which offers alternatives to traditional research tools such as ‘the interview’ (which often result in participants giving a researcher what they think they want to know or hear) and provides a range of aesthetic research methodologies that aim to harness the language of theatre and performance as an empowering and resistant research tool.
- Full Text:
- Authors: Sutherland, Alexandra
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/468527 , vital:77087 , https://doi.org/10.1080/10137548.2015.1085255
- Description: This book is part of the Applied Theatre series, which presents scholarship on different foci around applied theatre practices. The seven case studies of how applied theatre practices can be framed as research methodologies are practically and theoretically useful for students, practitioners and scholars engaged in community-driven, socially engaged theatre work. The book argues a particular approach to arts based research which offers alternatives to traditional research tools such as ‘the interview’ (which often result in participants giving a researcher what they think they want to know or hear) and provides a range of aesthetic research methodologies that aim to harness the language of theatre and performance as an empowering and resistant research tool.
- Full Text:
Appraising the appraisal framework: evidence from Grahamstown property advertisements
- Authors: Beangstrom, Tracy
- Date: 2015
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/54744 , vital:26608
- Description: This thesis considers how interpersonal meaning choices in property advertisements are best reflected in a context of constraint in Grahamstown, South Africa, using and appraising Martin & White’s (2005) APPRAISAL Framework. The study is comparative in two senses since the data is analysed using Martin & White’s (2005) APPRAISAL Framework and a revision to it, and property advertisements from two competing estate agencies are analysed: Remax Frontier Properties and Pam Golding Properties. An initial strict application of Martin & White’s (2005) framework is followed by a second, based on analyst difficulties and framework limitations experienced in the first analysis, as well as those experienced by other researchers. Revisions to the original framework include added ‘local’, context-driven features and sub-categories: Exclusivity and Convenience in Attitude, a Scale of Intensity in Graduation, and a category ‘Invite’ in Engagement. These enable a richer, more detailed account of the alignment strategies and interpersonal micro-politics at play in the property advertisements than is possible using the original framework. Findings from the analyses reveal four facts of note. Firstly, that while the original Martin & White (2005) APPRAISAL Framework captures a general level of interpersonal meaning in the data, it does so more fully when it includes contextual and contextually-driven categories that are informed by local knowledge. Secondly, two levels of meaning are expressed in the data. One is aimed at an ‘external’ audience; the other, truer, fuller and more contentious, is aimed at what appears to be the intended audience only. Thirdly, and relatedly, specific contextual and cultural knowledge is needed by the intended audience to access the intended meaning. Fourthly, both estate agencies promote values of high prestige, exclusivity, elitism and wealth as their intended meaning to align a like-minded audience, although Remax Frontier Properties attribute these values to location and features of the home to a greater extent than Pam Golding Properties, who place greater emphasis on the size of the home. The thesis suggests further avenues for research into the discourse of property advertising, as well as into overcoming certain context-specific limitations of the APPRAISAL Framework.
- Full Text:
- Authors: Beangstrom, Tracy
- Date: 2015
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/54744 , vital:26608
- Description: This thesis considers how interpersonal meaning choices in property advertisements are best reflected in a context of constraint in Grahamstown, South Africa, using and appraising Martin & White’s (2005) APPRAISAL Framework. The study is comparative in two senses since the data is analysed using Martin & White’s (2005) APPRAISAL Framework and a revision to it, and property advertisements from two competing estate agencies are analysed: Remax Frontier Properties and Pam Golding Properties. An initial strict application of Martin & White’s (2005) framework is followed by a second, based on analyst difficulties and framework limitations experienced in the first analysis, as well as those experienced by other researchers. Revisions to the original framework include added ‘local’, context-driven features and sub-categories: Exclusivity and Convenience in Attitude, a Scale of Intensity in Graduation, and a category ‘Invite’ in Engagement. These enable a richer, more detailed account of the alignment strategies and interpersonal micro-politics at play in the property advertisements than is possible using the original framework. Findings from the analyses reveal four facts of note. Firstly, that while the original Martin & White (2005) APPRAISAL Framework captures a general level of interpersonal meaning in the data, it does so more fully when it includes contextual and contextually-driven categories that are informed by local knowledge. Secondly, two levels of meaning are expressed in the data. One is aimed at an ‘external’ audience; the other, truer, fuller and more contentious, is aimed at what appears to be the intended audience only. Thirdly, and relatedly, specific contextual and cultural knowledge is needed by the intended audience to access the intended meaning. Fourthly, both estate agencies promote values of high prestige, exclusivity, elitism and wealth as their intended meaning to align a like-minded audience, although Remax Frontier Properties attribute these values to location and features of the home to a greater extent than Pam Golding Properties, who place greater emphasis on the size of the home. The thesis suggests further avenues for research into the discourse of property advertising, as well as into overcoming certain context-specific limitations of the APPRAISAL Framework.
- Full Text:
Aquatic invasions of the Nseleni River system: causes, consequences and control
- Authors: Jones, Roy William
- Date: 2015
- Subjects: Gastropoda -- South Africa , Introduced snails -- South Africa , Introduced mollusks -- South Africa , Loricariidae , Introduced fishes -- South Africa , Water hyacinth , Alien plants -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5928 , http://hdl.handle.net/10962/d1017806
- Description: Globalization has seen an unprecedented dispersal of exotic and alien species worldwide resulting in worldwide homogenization and sometimes extinction of indigenous or endemic taxa. When an exotic species becomes established in a new habitat the invasive organisms are capable of having an impact on indigenous community dynamics and the overall structure and function of ecosystems. Furthermore, the impact of invasion is determined by the geographical range, abundance and the per-capita or per-biomass effect of the invader. However, the success of the introduced organisms is reliant on their ability to acclimate to the physiochemical conditions of the newly invaded environment.Freshwater ecosystems are especially vulnerable to invasions because there are numerous potential routes of introduction including intentional pathways such as stocking, and unintentional pathways such as the release of ballast water and aquarium releases. Efforts to limit the introduction of invasive species or to manage established exotic populations are often hindered by insufficient understanding of the natural history of problematic species. Relatively little is known regarding the physiological tolerances of many taxa. Knowledge about specific species ecophysiological constraints allows for the prediction of future patterns of invasion more accurately, including where an introduced organism would probably survive, thrive and disperse. Furthermore, data on the physiological tolerances of an introduced exotic organism may provide data necessary for effective management and control. This studyinvestigated three invasive species in the Nseleni River system in a protected area in KwaZulu-Natal. The species studied were, Tarebia granifera (Quilted melania – Lamarck, 1822), Pterygoplichthys disjunctivus (Suckermouth armoured catfish - Weber, 1991) and Eichhornia crassipes (water hyacinth – (Martius) Solms-Laubach,). The Nseleni River flows into Lake Nsezi which is responsible for providing potable water to the surrounding towns and industry, as well as the surrounding rural communities. The Enseleni Nature reserve has become the centre for biodiversity dispersal in the immediate area, due to the change in landscape surrounding the protected area.An important step in developing alien invasive species management strategies in protected areas is determining their extent and invasive traits. Tarebia granifera is a prosobranch gastropod originally from South-East Asia that has become invasive in several countries around the world including South Africa. Snail populations were sampled at nine sites throughout the Nseleni/Mposa river system every six weeks over a twelve month period. The snail was abundant throughout the system, especially in shallow waters of less than 1m in depth.The first positive identification the loricariid catfish Pterygoplichthys disjunctivus for the Nseleni River was in 2006. The original introduction is believed to have been via the aquarium trade. The aim of the study was to assess the usefulness of the unified framework with regard to management of fish invasions by assessing the invasion stage of the loricariid population and identifying appropriate management actions using the Blackburn et al. (2011) framework. The fish were sampled at nine different sites and three different depths over a period of twelve months, as well as when two ichthyological surveys were carried out on the Nseleni River system. This invasive fish has been located throughout the system and both male and female fish were collected. The smallest fish sampled was a fingerling of a day or two old and the smallest pregnant female was a mere 270mm TL. This is a clear indication that this fish is breeding in the river system.Although T. granifera and P. disjunctivus were abundant in the Nseleni/Mposa river system, it was not clear what their role in the system was, and in particular if they were competing with any of the indigenous species. Therefore, isotope samples were collected from numerous taxa over a two week period, with the exception of Pterygoplichthys disjunctivus samples, which were collected over 12 months. The δ13C and δ15N signatures of all samples were determined. The niche overlap between the invasive and indigenous snails was effectively zero (1.02E-13%), indicating no shared food resources. The medium ranges of dNRb (7.14) and dCRb (9.07) for the invasive fish indicate that it utilizes a wider range of food resources and trophic levels than the majority of indigenous fish. A medium CDb value (2.34) for the invasive fish species, P. disjunctivus, describes medium trophic diversity, with three indigenous species possessing higher diversity and three possessing lower diversity. Furtherresults indicated that there was no direct dietary competition between P. disjunctivus and indigenous species. Eichhornia crassipes was first recorded on the Nseleni River in 1978, and has been shown to have a significant negative impact on the biodiversity of the Nseleni/Mposa River system and therefore required a control intervention. Although biological control using the two weevil species Neochetina eichhornia (Warner) and N. bruchi (Hustache) has been credited with affecting a good level of control, the lack of a manipulated post-release evaluation experiments has undermined this statement. Five experimental plots of water hyacinth of 20m2 were sprayed with an insecticide to control weevils. After ten months the plants in the sprayed plots were significantly bigger and heavier than those in the control plots that had natural populations of the biological control agents. This study has shown unequivocally that biological control has contributed significantly to the control of water hyacinth on the Nseleni/Mposa River system.The management plan for the Enseleni Nature Reserve identifies the need to control invasive and/or exotic organisms within the boundary of the protected area. In addition, set guidelines have been implemented on how to control these organisms, so that indigenous organisms are least affected. Lack of control of exotic organisms can have serious consequences for indigenous species. It is therefore of utmost importance that the population dynamics of the invading organism be understood, what the potential impact could be and how to control them. Furthermore, it has also acknowledged the threat of possible exotic species invasions from outside of the protected area that might result in threats to the protected area and that these must be investigated, researched and managed.This thesis has identified Tarebia granifera, Pterygoplichthys disjunctivus and Eichhornia crassipes as being a threat to indigenous biodiversity within the protected area, as well as in adjacent areas to the protected area. The thesis will therefore investigate the hypothesis that both Tarebia granifera and Pterygoplichthys disjunctivus are having a direct negative effect on available food resources for indigenous species of organisms. In addition, this thesis will investigate if theNeochetina species that have previously been introduced onto E. crassipes are having any negative effect on this invasive alien aquatic plant.
- Full Text:
- Authors: Jones, Roy William
- Date: 2015
- Subjects: Gastropoda -- South Africa , Introduced snails -- South Africa , Introduced mollusks -- South Africa , Loricariidae , Introduced fishes -- South Africa , Water hyacinth , Alien plants -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5928 , http://hdl.handle.net/10962/d1017806
- Description: Globalization has seen an unprecedented dispersal of exotic and alien species worldwide resulting in worldwide homogenization and sometimes extinction of indigenous or endemic taxa. When an exotic species becomes established in a new habitat the invasive organisms are capable of having an impact on indigenous community dynamics and the overall structure and function of ecosystems. Furthermore, the impact of invasion is determined by the geographical range, abundance and the per-capita or per-biomass effect of the invader. However, the success of the introduced organisms is reliant on their ability to acclimate to the physiochemical conditions of the newly invaded environment.Freshwater ecosystems are especially vulnerable to invasions because there are numerous potential routes of introduction including intentional pathways such as stocking, and unintentional pathways such as the release of ballast water and aquarium releases. Efforts to limit the introduction of invasive species or to manage established exotic populations are often hindered by insufficient understanding of the natural history of problematic species. Relatively little is known regarding the physiological tolerances of many taxa. Knowledge about specific species ecophysiological constraints allows for the prediction of future patterns of invasion more accurately, including where an introduced organism would probably survive, thrive and disperse. Furthermore, data on the physiological tolerances of an introduced exotic organism may provide data necessary for effective management and control. This studyinvestigated three invasive species in the Nseleni River system in a protected area in KwaZulu-Natal. The species studied were, Tarebia granifera (Quilted melania – Lamarck, 1822), Pterygoplichthys disjunctivus (Suckermouth armoured catfish - Weber, 1991) and Eichhornia crassipes (water hyacinth – (Martius) Solms-Laubach,). The Nseleni River flows into Lake Nsezi which is responsible for providing potable water to the surrounding towns and industry, as well as the surrounding rural communities. The Enseleni Nature reserve has become the centre for biodiversity dispersal in the immediate area, due to the change in landscape surrounding the protected area.An important step in developing alien invasive species management strategies in protected areas is determining their extent and invasive traits. Tarebia granifera is a prosobranch gastropod originally from South-East Asia that has become invasive in several countries around the world including South Africa. Snail populations were sampled at nine sites throughout the Nseleni/Mposa river system every six weeks over a twelve month period. The snail was abundant throughout the system, especially in shallow waters of less than 1m in depth.The first positive identification the loricariid catfish Pterygoplichthys disjunctivus for the Nseleni River was in 2006. The original introduction is believed to have been via the aquarium trade. The aim of the study was to assess the usefulness of the unified framework with regard to management of fish invasions by assessing the invasion stage of the loricariid population and identifying appropriate management actions using the Blackburn et al. (2011) framework. The fish were sampled at nine different sites and three different depths over a period of twelve months, as well as when two ichthyological surveys were carried out on the Nseleni River system. This invasive fish has been located throughout the system and both male and female fish were collected. The smallest fish sampled was a fingerling of a day or two old and the smallest pregnant female was a mere 270mm TL. This is a clear indication that this fish is breeding in the river system.Although T. granifera and P. disjunctivus were abundant in the Nseleni/Mposa river system, it was not clear what their role in the system was, and in particular if they were competing with any of the indigenous species. Therefore, isotope samples were collected from numerous taxa over a two week period, with the exception of Pterygoplichthys disjunctivus samples, which were collected over 12 months. The δ13C and δ15N signatures of all samples were determined. The niche overlap between the invasive and indigenous snails was effectively zero (1.02E-13%), indicating no shared food resources. The medium ranges of dNRb (7.14) and dCRb (9.07) for the invasive fish indicate that it utilizes a wider range of food resources and trophic levels than the majority of indigenous fish. A medium CDb value (2.34) for the invasive fish species, P. disjunctivus, describes medium trophic diversity, with three indigenous species possessing higher diversity and three possessing lower diversity. Furtherresults indicated that there was no direct dietary competition between P. disjunctivus and indigenous species. Eichhornia crassipes was first recorded on the Nseleni River in 1978, and has been shown to have a significant negative impact on the biodiversity of the Nseleni/Mposa River system and therefore required a control intervention. Although biological control using the two weevil species Neochetina eichhornia (Warner) and N. bruchi (Hustache) has been credited with affecting a good level of control, the lack of a manipulated post-release evaluation experiments has undermined this statement. Five experimental plots of water hyacinth of 20m2 were sprayed with an insecticide to control weevils. After ten months the plants in the sprayed plots were significantly bigger and heavier than those in the control plots that had natural populations of the biological control agents. This study has shown unequivocally that biological control has contributed significantly to the control of water hyacinth on the Nseleni/Mposa River system.The management plan for the Enseleni Nature Reserve identifies the need to control invasive and/or exotic organisms within the boundary of the protected area. In addition, set guidelines have been implemented on how to control these organisms, so that indigenous organisms are least affected. Lack of control of exotic organisms can have serious consequences for indigenous species. It is therefore of utmost importance that the population dynamics of the invading organism be understood, what the potential impact could be and how to control them. Furthermore, it has also acknowledged the threat of possible exotic species invasions from outside of the protected area that might result in threats to the protected area and that these must be investigated, researched and managed.This thesis has identified Tarebia granifera, Pterygoplichthys disjunctivus and Eichhornia crassipes as being a threat to indigenous biodiversity within the protected area, as well as in adjacent areas to the protected area. The thesis will therefore investigate the hypothesis that both Tarebia granifera and Pterygoplichthys disjunctivus are having a direct negative effect on available food resources for indigenous species of organisms. In addition, this thesis will investigate if theNeochetina species that have previously been introduced onto E. crassipes are having any negative effect on this invasive alien aquatic plant.
- Full Text:
Art investment as a portfolio diversification strategy in South Africa
- Botha, Ferdi, Scott, Brett, Snowball, Jeanette D
- Authors: Botha, Ferdi , Scott, Brett , Snowball, Jeanette D
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67422 , vital:29086
- Description: publisher version , Art has been suggested as a good way to diversify investment portfolios during times of financial uncertainty. The argument is that art exhibits different risk and return characteristics to conventional investments in other asset classes. The new Citadel Art Price index offered the opportunity to test this theory in the South African context. The Citadel index uses the hedonic regression method with observations drawn from the top 100, 50 and 20 artists by sales volume, giving approximately 29 503 total auction observations. The Index consists of quarterly data from the period 2000Q1 to 2013Q3. A VAR of the art price index, Johannesburg Stock Exchange all-share index, house price index, and South African government bond index were used. Flowing from the VAR results, additional analyses included variance decomposition, impulse response, and, to determine volatility, variance and standard deviation measures for each index. Results show that, when there are increased returns on the stock market in the previous period and wealth increases, there is a change in the Citadel Art Price Index in the same direction. This finding is consistent with Goetzmann et al. (2009), who reported that there is a strong relationship between art and equity markets and that art price changes are driven by capital gains and losses. No significant difference was found between the house price index and the art price index, and neither between the art and government bond price indices. Overall, the South African art market does not offer the opportunity to diversify portfolios dominated by either property, bonds, or shares.
- Full Text:
- Authors: Botha, Ferdi , Scott, Brett , Snowball, Jeanette D
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67422 , vital:29086
- Description: publisher version , Art has been suggested as a good way to diversify investment portfolios during times of financial uncertainty. The argument is that art exhibits different risk and return characteristics to conventional investments in other asset classes. The new Citadel Art Price index offered the opportunity to test this theory in the South African context. The Citadel index uses the hedonic regression method with observations drawn from the top 100, 50 and 20 artists by sales volume, giving approximately 29 503 total auction observations. The Index consists of quarterly data from the period 2000Q1 to 2013Q3. A VAR of the art price index, Johannesburg Stock Exchange all-share index, house price index, and South African government bond index were used. Flowing from the VAR results, additional analyses included variance decomposition, impulse response, and, to determine volatility, variance and standard deviation measures for each index. Results show that, when there are increased returns on the stock market in the previous period and wealth increases, there is a change in the Citadel Art Price Index in the same direction. This finding is consistent with Goetzmann et al. (2009), who reported that there is a strong relationship between art and equity markets and that art price changes are driven by capital gains and losses. No significant difference was found between the house price index and the art price index, and neither between the art and government bond price indices. Overall, the South African art market does not offer the opportunity to diversify portfolios dominated by either property, bonds, or shares.
- Full Text:
Aspects of the biology and life history of largespot pompano, Trachinotus botla, in South Africa
- Parker, Daniel M, Booth, Anthony J
- Authors: Parker, Daniel M , Booth, Anthony J
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123798 , vital:35499 , https://doi.10.1071/MF14029
- Description: Trachinotus botla is an important recreational surf zone-dependent fish species distributed in the Indo-west Pacific from South Africa to Australia. In South Africa it is restricted to the northern KwaZulu-Natal coast. Biological investigations revealed that it is a fast growing species that attains a maximum age of, 7 years. Males and females sexually matured in their third year. It has a protracted summer spawning season with evidence of serial spawning behaviour. T. botla is an opportunistic predator with a generalist diet, with fish feeding on a wide variety of prey items particularly those that are temporally ‘superabundant’. Small fish fed predominantly on copepods and terrestrial insects, whereas larger fish consumed bivalves and crabs. Teleosts, primarily engraulids, were important components to the diet of fish of all sizes. An ontogenetic dietary shift was observed just after sexual maturity (300-mm fork length) that is possibly linked to a change in habitat preference with larger fish foraging on deeper reefs.
- Full Text:
- Authors: Parker, Daniel M , Booth, Anthony J
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123798 , vital:35499 , https://doi.10.1071/MF14029
- Description: Trachinotus botla is an important recreational surf zone-dependent fish species distributed in the Indo-west Pacific from South Africa to Australia. In South Africa it is restricted to the northern KwaZulu-Natal coast. Biological investigations revealed that it is a fast growing species that attains a maximum age of, 7 years. Males and females sexually matured in their third year. It has a protracted summer spawning season with evidence of serial spawning behaviour. T. botla is an opportunistic predator with a generalist diet, with fish feeding on a wide variety of prey items particularly those that are temporally ‘superabundant’. Small fish fed predominantly on copepods and terrestrial insects, whereas larger fish consumed bivalves and crabs. Teleosts, primarily engraulids, were important components to the diet of fish of all sizes. An ontogenetic dietary shift was observed just after sexual maturity (300-mm fork length) that is possibly linked to a change in habitat preference with larger fish foraging on deeper reefs.
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Aspects of the biology, thermal physiology and nutritional ecology of Pareuchaetes insulata (Walker) (Lepidoptera: Erebidae: Arctiinae), a specialist herbivore introduced into South Africa for the biological control of Chromolaena odorata (L.) King and Robinson (Asteraceae)
- Authors: Uyi, Osariyekemwen
- Date: 2015
- Subjects: Chromolaena odorata , Chromolaena odorata -- Biological control -- South Africa , Arctiidae
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5936 , http://hdl.handle.net/10962/d1017916
- Description: Chromolaena odorata (L.) King and Robinson (Asteraceae) is an invasive weedy shrub native to the Americas that has proven to be a significant economic and ecological burden to many tropical and sub-tropical regions of the world where it impacts negatively on agriculture, biodiversity and livelihoods. A distinct biotype of C. odorata was first recognised as naturalized in KwaZulu-Natal (KZN) province, South Africa, in the 1940s and has since spread to other climatically suitable provinces. Pareuchaetes insulata (Walker) (Lepidoptera: Erebidae: Arctiinae) was released in KZN, South Africa, as a biological control agent against the weed between 2001 and 2009. Although the moth did establish at one out of some 30 release sites, its population level is generally low in the field. This thesis attempts to unravel the reasons for the poor performance of P. insulata in South Africa.Studies of life history traits of P. insulata in the laboratory indicated that the moth possess good biological attributes such as low mortality, high fecundity, egg hatchability and high female mating success. Overall, adult female moths eclosed before their male counterparts suggesting the presence of protogyny. Beyond the contribution of this study to our understanding of the life history traits of erebid moths, it hypothesized that the absence of protandry might have contributed to the low population levels of the moth in the field. To determine if a degree of agent-host plant incompatibility is culpable for the poor performance of P. insulata, insect performance metrics were compared on two distinct C. odorata plants (one from Florida and another from South Africa) in laboratory experiments. Pareuchaetes insulata performance metrics were similar on both plant forms; there were no significant differences in total leaf area consumed, egg and larval development, immature survival rates, feeding index (FI), host suitability index (HSI), growth index (GI), and fecundity between the Floridian and southern African C. odorata plants. In sum, there was no evidence to demonstrate that differences in plant forms in C. odorata are culpable for the poor performance of P. insulata in South Africa.The effects of temperature on the developmental and reproductive life history traits, locomotion performance and thermal tolerance range of P. insulata were studied in order to elucidate the possible role of temperature on the poor performance of the moth. The results showed that at temperatures below 25 °C, mortality increased and development time was prolonged. Fecundity and egg hatchability were negatively affected at a constant temperature of 15 °C. Results futher showed that third instar larvae were unable to initiate movement at 6 °C and locomotor abilities were significantly reduced at 11 °C. In sum, it is hypothesized that both direct and indirect negative impacts of low temperature may partly explain the poor performance of P. insulata in South Africa. Theeffects of seasonal and spatial variations in the leaf characteristics of C. odorata on the performance of P. insulata were investigated. Foliar nitrogen and magnesium concentrations were higher in shaded plants during winter due to low temperatures. Leaves of C. odorata plants growing in the shaded habitat (relative to full sun) and leaves of plants during autumn (relative to winter) were more nutritionally balanced and suitable for herbivore performance. Consequently, P. insulata developed faster, had heavier pupal mass and increased fecundity when reared on shaded leaves (relative to full sun) or when reared on autumn leaves compared to leaves growing in winter. This study demonstrates that low winter temperatures can indirectly affect insect herbivore performance by changing the phytochemistry of host plant and hypothesized that excess nitrogen and possibly magnesium may have detrimental effects on the insect herbivore performance.A cross-feeding experiment was conducted to determine P. insulata response to a change in the diet of offspring due to a shift in plant quality in shaded versus full sun habitats. The results showed that a ‘negative switch’ in herbivore diet (i.e. when progeny from parents reared on shaded leaves were fed on full sun leaves) resulted in high (40%) mortality, prolonged development time and reduced fecundity. Thus full sun foliage is an inferior diet for P. insulata offspring. In laboratory experiments, foliar nitrogen was positively correlated with the performance of P. insulata. From this study, it is demonstrably evident that the poor performance of P. insulata on C. odorata in South Africa is caused by multiple factors such as low temperatures as well as spatio-temporal variations in the leaf characteristic of C. odorata leaves. This study shows the complexity of determining the causes of low populations and apparent low impact of biological control agents and herbivorous insects generally, in the field. The implications of this research to the biological control programme against C. odorata and the direction of future research for the control of C. odorata are discussed.
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- Authors: Uyi, Osariyekemwen
- Date: 2015
- Subjects: Chromolaena odorata , Chromolaena odorata -- Biological control -- South Africa , Arctiidae
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5936 , http://hdl.handle.net/10962/d1017916
- Description: Chromolaena odorata (L.) King and Robinson (Asteraceae) is an invasive weedy shrub native to the Americas that has proven to be a significant economic and ecological burden to many tropical and sub-tropical regions of the world where it impacts negatively on agriculture, biodiversity and livelihoods. A distinct biotype of C. odorata was first recognised as naturalized in KwaZulu-Natal (KZN) province, South Africa, in the 1940s and has since spread to other climatically suitable provinces. Pareuchaetes insulata (Walker) (Lepidoptera: Erebidae: Arctiinae) was released in KZN, South Africa, as a biological control agent against the weed between 2001 and 2009. Although the moth did establish at one out of some 30 release sites, its population level is generally low in the field. This thesis attempts to unravel the reasons for the poor performance of P. insulata in South Africa.Studies of life history traits of P. insulata in the laboratory indicated that the moth possess good biological attributes such as low mortality, high fecundity, egg hatchability and high female mating success. Overall, adult female moths eclosed before their male counterparts suggesting the presence of protogyny. Beyond the contribution of this study to our understanding of the life history traits of erebid moths, it hypothesized that the absence of protandry might have contributed to the low population levels of the moth in the field. To determine if a degree of agent-host plant incompatibility is culpable for the poor performance of P. insulata, insect performance metrics were compared on two distinct C. odorata plants (one from Florida and another from South Africa) in laboratory experiments. Pareuchaetes insulata performance metrics were similar on both plant forms; there were no significant differences in total leaf area consumed, egg and larval development, immature survival rates, feeding index (FI), host suitability index (HSI), growth index (GI), and fecundity between the Floridian and southern African C. odorata plants. In sum, there was no evidence to demonstrate that differences in plant forms in C. odorata are culpable for the poor performance of P. insulata in South Africa.The effects of temperature on the developmental and reproductive life history traits, locomotion performance and thermal tolerance range of P. insulata were studied in order to elucidate the possible role of temperature on the poor performance of the moth. The results showed that at temperatures below 25 °C, mortality increased and development time was prolonged. Fecundity and egg hatchability were negatively affected at a constant temperature of 15 °C. Results futher showed that third instar larvae were unable to initiate movement at 6 °C and locomotor abilities were significantly reduced at 11 °C. In sum, it is hypothesized that both direct and indirect negative impacts of low temperature may partly explain the poor performance of P. insulata in South Africa. Theeffects of seasonal and spatial variations in the leaf characteristics of C. odorata on the performance of P. insulata were investigated. Foliar nitrogen and magnesium concentrations were higher in shaded plants during winter due to low temperatures. Leaves of C. odorata plants growing in the shaded habitat (relative to full sun) and leaves of plants during autumn (relative to winter) were more nutritionally balanced and suitable for herbivore performance. Consequently, P. insulata developed faster, had heavier pupal mass and increased fecundity when reared on shaded leaves (relative to full sun) or when reared on autumn leaves compared to leaves growing in winter. This study demonstrates that low winter temperatures can indirectly affect insect herbivore performance by changing the phytochemistry of host plant and hypothesized that excess nitrogen and possibly magnesium may have detrimental effects on the insect herbivore performance.A cross-feeding experiment was conducted to determine P. insulata response to a change in the diet of offspring due to a shift in plant quality in shaded versus full sun habitats. The results showed that a ‘negative switch’ in herbivore diet (i.e. when progeny from parents reared on shaded leaves were fed on full sun leaves) resulted in high (40%) mortality, prolonged development time and reduced fecundity. Thus full sun foliage is an inferior diet for P. insulata offspring. In laboratory experiments, foliar nitrogen was positively correlated with the performance of P. insulata. From this study, it is demonstrably evident that the poor performance of P. insulata on C. odorata in South Africa is caused by multiple factors such as low temperatures as well as spatio-temporal variations in the leaf characteristic of C. odorata leaves. This study shows the complexity of determining the causes of low populations and apparent low impact of biological control agents and herbivorous insects generally, in the field. The implications of this research to the biological control programme against C. odorata and the direction of future research for the control of C. odorata are discussed.
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Assessment in higher education: reframing traditional understandings and practices
- Clarence, Sherran, Quinn, Lynn, Vorster, Jo-Anne E
- Authors: Clarence, Sherran , Quinn, Lynn , Vorster, Jo-Anne E
- Date: 2015
- Language: English
- Type: Book , text
- Identifier: http://hdl.handle.net/10962/59534 , vital:27624
- Description: The case studies in this publication provide examples of lecturers who have considered the role of assessment in their courses carefully. All of them have engaged with matters related to assessment as part of the formal courses or qualifications offered by staff of the Centre for Higher Education Research, Teaching and Learning (CHERTL) at Rhodes University. In these courses lecturers are encouraged to reflect critically on their current assessment practices, engage with some of the literature and research on assessment in higher education, and then re-conceptualise their assessment methods and approaches. These case studies were drawn from the assignments and portfolios that they completed as part of the summative assessment for the courses they attended. The purpose of the case studies is pedagogic and to illustrate a range of assessment practices and principles. For the sake of clarity some of the details have been omitted or slightly changed.
- Full Text:
- Authors: Clarence, Sherran , Quinn, Lynn , Vorster, Jo-Anne E
- Date: 2015
- Language: English
- Type: Book , text
- Identifier: http://hdl.handle.net/10962/59534 , vital:27624
- Description: The case studies in this publication provide examples of lecturers who have considered the role of assessment in their courses carefully. All of them have engaged with matters related to assessment as part of the formal courses or qualifications offered by staff of the Centre for Higher Education Research, Teaching and Learning (CHERTL) at Rhodes University. In these courses lecturers are encouraged to reflect critically on their current assessment practices, engage with some of the literature and research on assessment in higher education, and then re-conceptualise their assessment methods and approaches. These case studies were drawn from the assignments and portfolios that they completed as part of the summative assessment for the courses they attended. The purpose of the case studies is pedagogic and to illustrate a range of assessment practices and principles. For the sake of clarity some of the details have been omitted or slightly changed.
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Assessment of the spatial and temporal variations in periphyton communities along a small temperate river system: A multimetric and stable isotope analysis approach
- Dalu, Tatenda, Bere, Taurai, Richoux, Nicole B, Froneman, P William
- Authors: Dalu, Tatenda , Bere, Taurai , Richoux, Nicole B , Froneman, P William
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124249 , vital:35580 , https://doi.org/10.1016/j.sajb.2015.05.028
- Description: Periphyton community structure and stable isotope values have been identified as potential indicators of anthropogenic nitrogen pollution, an increasingly important challenge in aquatic systems. The aim of the study was to assess the spatio-temporal changes in periphyton characteristics to identify potential anthropogenic nitrogen pollution sources such as agricultural and sewage discharge within the Kowie River catchment, South Africa. Periphyton was collected once a season from five sites between September 2012 and May 2013. Diversity indices, multimetric and stable isotope analyses were employed for describing the spatial and temporal dynamics of periphyton community assemblages. Water depth, salinity, resistivity, oxygen reduction potential, nitrates, water velocity and conductivity were the major factors affecting periphyton community structure. Eighty-seven periphyton taxa belonging to 43 genera were recorded throughout the study sites and periods. Periphyton species richness, abundance and stable isotope signatures differed significantly among sites but not among seasons. The lower sections of the Kowie River were polluted by anthropogenic sources as indicated by the high periphytic isotopic nitrogen values (7.9–15.2‰) compared to the pristine upstream sites (4–8‰). We recommend that researchers use a combination of community structure and stable isotope measurements to monitor the periphyton in lotic systems.
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- Authors: Dalu, Tatenda , Bere, Taurai , Richoux, Nicole B , Froneman, P William
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124249 , vital:35580 , https://doi.org/10.1016/j.sajb.2015.05.028
- Description: Periphyton community structure and stable isotope values have been identified as potential indicators of anthropogenic nitrogen pollution, an increasingly important challenge in aquatic systems. The aim of the study was to assess the spatio-temporal changes in periphyton characteristics to identify potential anthropogenic nitrogen pollution sources such as agricultural and sewage discharge within the Kowie River catchment, South Africa. Periphyton was collected once a season from five sites between September 2012 and May 2013. Diversity indices, multimetric and stable isotope analyses were employed for describing the spatial and temporal dynamics of periphyton community assemblages. Water depth, salinity, resistivity, oxygen reduction potential, nitrates, water velocity and conductivity were the major factors affecting periphyton community structure. Eighty-seven periphyton taxa belonging to 43 genera were recorded throughout the study sites and periods. Periphyton species richness, abundance and stable isotope signatures differed significantly among sites but not among seasons. The lower sections of the Kowie River were polluted by anthropogenic sources as indicated by the high periphytic isotopic nitrogen values (7.9–15.2‰) compared to the pristine upstream sites (4–8‰). We recommend that researchers use a combination of community structure and stable isotope measurements to monitor the periphyton in lotic systems.
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Assignment of spin and parity to states in the nucleus ¹⁹⁶T1
- Authors: Uwitonze, Pierre Celestin
- Date: 2015
- Subjects: Nuclear spin , Particles (Nuclear physics) -- Chirality
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5558 , http://hdl.handle.net/10962/d1017903
- Description: This work presents a study of high-spin states in the nucleus ¹⁹⁶Tl via γ-spectroscopy. ¹⁹⁶Tl was produced via the ¹⁹⁷Au(⁴He,5n) ¹⁹⁶Tl reaction at a beam energy of 63 MeV. The γ-γ coincidence measurements were performed using the AFRODITE γ-spectrometer array at iThemba LABS. The previous level scheme of ¹⁹⁶Tl has been extended up to an excitation of 4071 keV including 24 new γ-ray transitions. The spin and parity assignment to levels was made from the directional correlation of oriented nuclei (DCO) and linear polarization anisotropy ratios. An analysis of the B(M1)/B(E2) ratios was found to be consistent with the configuration of πh₉/₂♁vi₁₃/₂ for the ground state band. Although no chiral band was found in ¹⁹⁶TI and ¹⁹⁸TI.
- Full Text:
- Authors: Uwitonze, Pierre Celestin
- Date: 2015
- Subjects: Nuclear spin , Particles (Nuclear physics) -- Chirality
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5558 , http://hdl.handle.net/10962/d1017903
- Description: This work presents a study of high-spin states in the nucleus ¹⁹⁶Tl via γ-spectroscopy. ¹⁹⁶Tl was produced via the ¹⁹⁷Au(⁴He,5n) ¹⁹⁶Tl reaction at a beam energy of 63 MeV. The γ-γ coincidence measurements were performed using the AFRODITE γ-spectrometer array at iThemba LABS. The previous level scheme of ¹⁹⁶Tl has been extended up to an excitation of 4071 keV including 24 new γ-ray transitions. The spin and parity assignment to levels was made from the directional correlation of oriented nuclei (DCO) and linear polarization anisotropy ratios. An analysis of the B(M1)/B(E2) ratios was found to be consistent with the configuration of πh₉/₂♁vi₁₃/₂ for the ground state band. Although no chiral band was found in ¹⁹⁶TI and ¹⁹⁸TI.
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Azawan: precolonial musical culture and Saharawi nationalism in the refugee camps of the Hamada Desert in Algeria
- Authors: Amoros, Luis Gimenez
- Date: 2015
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59710 , vital:27641 , http://dx.doi.org/10.21504/amj.v10i1.1225
- Description: This article analyses Saharawi music as performed for the refugee community in the camps. I argue that the construction and evolution of Saharawi music in the camps is divided into two main areas: nationalism in relation to the decolonisation of Western Sahara, and maintenance of cultural values in Saharawi music found in the historical retention of the Haul modal system originating in precolonial Saharawi culture. Local audiences use the term Azawan to define the combination of nationalist sentiments and retention of their precolonial musical culture in Saharawi music.
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- Authors: Amoros, Luis Gimenez
- Date: 2015
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59710 , vital:27641 , http://dx.doi.org/10.21504/amj.v10i1.1225
- Description: This article analyses Saharawi music as performed for the refugee community in the camps. I argue that the construction and evolution of Saharawi music in the camps is divided into two main areas: nationalism in relation to the decolonisation of Western Sahara, and maintenance of cultural values in Saharawi music found in the historical retention of the Haul modal system originating in precolonial Saharawi culture. Local audiences use the term Azawan to define the combination of nationalist sentiments and retention of their precolonial musical culture in Saharawi music.
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Bacterial degradation of fossil fuel waste in aqueous and solid media
- Authors: Edeki, Oghenekume Gerald
- Date: 2015
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54565 , vital:26588
- Description: The generation of environmental pollutants worldwide is mainly due to over reliance on fossil fuels as a source of energy. As a result of the negative impacts of these pollutants on the health of humans, animals, plants and microorganisms, global attention has been directed towards ways of containing this problem. Biodegradation of fossil fuel is one of the most effective methods used to remediate contaminated systems. However with regard to coal waste, much of what is known is based on the ability of fungal species to biosolubilize this material under enrichment conditions in a laboratory setting. For effective biodegradation as a remediation technique, there is an immediate need to source, isolate, enrich and incorporate other microorganisms such as bacteria into bioremediation technologies. The goal of this dissertation was to isolate bacteria from fossil fuel contaminated environments and to demonstrate competence for petroleum hydrocarbon degradation which was achieved using a combination of analytical methods such as spectrophotometry, FT-IR, SEM and GC-MS. Screening for biodegradation of coal and petroleum hydrocarbon waste resulted in the isolation of 75 bacterial strains of which 15 showed good potential for use in developing remedial biotechnologies. Spectrophotometric analysis of bacteria both in coal and petroleum hydrocarbons (all in aqueous media) revealed a high proliferation of bacteria in these media suggesting that these microbes can effectively utilize the various substrates as a source of carbon. The isolated bacteria effectively degraded and converted waste coal to humic and fulvic acids; products required to enrich coal mine dumps to support re-vegetation. Scanning electron microscopy showed the attachment of bacteria to waste coal surfaces and the disintegration of coal structures while FT-IR analysis of extracted humic-like substances from biodegraded waste coal revealed these to have the same functional groups as commercial humic acid. Specific consortia which were established using the isolated bacterial strains, showed greater potential to biodegrade coal than did individual isolates. This was evident in experiments carried out on coal and hydrocarbons where the efficient colonization and utilization of these substrates by each bacterial consortium was observed due to the effect of added nutrients such as algae. The biodegradation of liquid petroleum hydrocarbons (diesel and BTEX) was also achieved using the 15 bacterial isolates. GC-MS analysis of extracted residual PHC from aqueous and solid media revealed rapid breakdown of these contaminants by bacteria. Different bacterial consortia established from the individual isolates were shown to be more efficient than single isolates indicating that formulated consortia are the biocatalysts of choice for fossil fuel biodegradation. This study represents one of the most detailed screenings for bacteria from fossil fuel contaminated sites and the isolation of strains with potential to biodegrade coal and petroleum hydrocarbon wastes. Several consortia have been developed and these show potential for further development as biocatalysts for use in bioremediation technology development. An evaluation of efficiency of each established bacterial consortium for biodegradation in a commercial and/or industrial setting at pilot scale is now needed.
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- Authors: Edeki, Oghenekume Gerald
- Date: 2015
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54565 , vital:26588
- Description: The generation of environmental pollutants worldwide is mainly due to over reliance on fossil fuels as a source of energy. As a result of the negative impacts of these pollutants on the health of humans, animals, plants and microorganisms, global attention has been directed towards ways of containing this problem. Biodegradation of fossil fuel is one of the most effective methods used to remediate contaminated systems. However with regard to coal waste, much of what is known is based on the ability of fungal species to biosolubilize this material under enrichment conditions in a laboratory setting. For effective biodegradation as a remediation technique, there is an immediate need to source, isolate, enrich and incorporate other microorganisms such as bacteria into bioremediation technologies. The goal of this dissertation was to isolate bacteria from fossil fuel contaminated environments and to demonstrate competence for petroleum hydrocarbon degradation which was achieved using a combination of analytical methods such as spectrophotometry, FT-IR, SEM and GC-MS. Screening for biodegradation of coal and petroleum hydrocarbon waste resulted in the isolation of 75 bacterial strains of which 15 showed good potential for use in developing remedial biotechnologies. Spectrophotometric analysis of bacteria both in coal and petroleum hydrocarbons (all in aqueous media) revealed a high proliferation of bacteria in these media suggesting that these microbes can effectively utilize the various substrates as a source of carbon. The isolated bacteria effectively degraded and converted waste coal to humic and fulvic acids; products required to enrich coal mine dumps to support re-vegetation. Scanning electron microscopy showed the attachment of bacteria to waste coal surfaces and the disintegration of coal structures while FT-IR analysis of extracted humic-like substances from biodegraded waste coal revealed these to have the same functional groups as commercial humic acid. Specific consortia which were established using the isolated bacterial strains, showed greater potential to biodegrade coal than did individual isolates. This was evident in experiments carried out on coal and hydrocarbons where the efficient colonization and utilization of these substrates by each bacterial consortium was observed due to the effect of added nutrients such as algae. The biodegradation of liquid petroleum hydrocarbons (diesel and BTEX) was also achieved using the 15 bacterial isolates. GC-MS analysis of extracted residual PHC from aqueous and solid media revealed rapid breakdown of these contaminants by bacteria. Different bacterial consortia established from the individual isolates were shown to be more efficient than single isolates indicating that formulated consortia are the biocatalysts of choice for fossil fuel biodegradation. This study represents one of the most detailed screenings for bacteria from fossil fuel contaminated sites and the isolation of strains with potential to biodegrade coal and petroleum hydrocarbon wastes. Several consortia have been developed and these show potential for further development as biocatalysts for use in bioremediation technology development. An evaluation of efficiency of each established bacterial consortium for biodegradation in a commercial and/or industrial setting at pilot scale is now needed.
- Full Text: