Enhanced triplet state yields in aqueous media of asymmetric zinc phthalocyanines when conjugated to silver nanoflowers
- D'Souza, Sarah, George, Reama, Göksel, Meltem, Atilla, Devrim, Durmus, Mahmut, Nyokong, Tebello
- Authors: D'Souza, Sarah , George, Reama , Göksel, Meltem , Atilla, Devrim , Durmus, Mahmut , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189099 , vital:44816 , xlink:href="https://doi.org/10.1016/j.poly.2015.08.017"
- Description: Novel low symmetry water-soluble zinc phthalocyanines (ZnPcs, complexes 1 and 2) were synthesized and then mixed with silver nanoflowers. Photophysical and photochemical studies were performed in order to determine the efficiency of complexes 1 and 2 as photosensitizers when alone and when combined with the silver nanoflowers. The Pcs show low fluorescence quantum yields and excellent triplet quantum yields of 0.78 (for 1) and 0.66 (for 2) in aqueous media. The triplet quantum yield values increased to 0.80 and 0.89, respectively, in the presence of silver nanoflowers. Long triplet lifetimes ranging from 180 to 200 μs in DMSO were obtained for complexes 1, 2 and their conjugates with silver nanoflowers.
- Full Text:
- Date Issued: 2015
- Authors: D'Souza, Sarah , George, Reama , Göksel, Meltem , Atilla, Devrim , Durmus, Mahmut , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189099 , vital:44816 , xlink:href="https://doi.org/10.1016/j.poly.2015.08.017"
- Description: Novel low symmetry water-soluble zinc phthalocyanines (ZnPcs, complexes 1 and 2) were synthesized and then mixed with silver nanoflowers. Photophysical and photochemical studies were performed in order to determine the efficiency of complexes 1 and 2 as photosensitizers when alone and when combined with the silver nanoflowers. The Pcs show low fluorescence quantum yields and excellent triplet quantum yields of 0.78 (for 1) and 0.66 (for 2) in aqueous media. The triplet quantum yield values increased to 0.80 and 0.89, respectively, in the presence of silver nanoflowers. Long triplet lifetimes ranging from 180 to 200 μs in DMSO were obtained for complexes 1, 2 and their conjugates with silver nanoflowers.
- Full Text:
- Date Issued: 2015
The effects of gold coated and uncoated zinc oxide nanohexagons on the photophysicochemical properties of the low symmetry zinc phthalocyanine
- D'Souza, Sarah, Ogbodu, Racheal O, Nyokong, Tebello
- Authors: D'Souza, Sarah , Ogbodu, Racheal O , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7280 , http://hdl.handle.net/10962/d1020317
- Description: A new low symmetry, Zn phthalocyanine monosubstituted with diethylaminoethanethiol (mDEAET ZnPc) was synthesized and characterized. This work reports on its photophysical and photochemical properties of mDEAET ZnPc alone and when conjugated to gold coated and uncoated zinc oxide nanohexagons (ZnO NHXs). The photophysicochemical properties generally improved in the presence of the ZnO NHXs. These complexes were also tested for their photodynamic antimicrobial activity against Staphylococcus aureus (S. aureus). The Pc alone showed remarkable growth inhibition even at concentrations as low as 0.05 mg/mL. The conjugates showed a high photoinactivation of S. aureus after 30 min at a fluence of 90 mW cm−2 at a concentration of 0.05 mg/mL. The ZnPc-ZnO NHX conjugates produced the best antimicrobial results. , Original publication is available at http://dx.doi.org/10.1016/j.molstruc.2015.06.088
- Full Text: false
- Authors: D'Souza, Sarah , Ogbodu, Racheal O , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7280 , http://hdl.handle.net/10962/d1020317
- Description: A new low symmetry, Zn phthalocyanine monosubstituted with diethylaminoethanethiol (mDEAET ZnPc) was synthesized and characterized. This work reports on its photophysical and photochemical properties of mDEAET ZnPc alone and when conjugated to gold coated and uncoated zinc oxide nanohexagons (ZnO NHXs). The photophysicochemical properties generally improved in the presence of the ZnO NHXs. These complexes were also tested for their photodynamic antimicrobial activity against Staphylococcus aureus (S. aureus). The Pc alone showed remarkable growth inhibition even at concentrations as low as 0.05 mg/mL. The conjugates showed a high photoinactivation of S. aureus after 30 min at a fluence of 90 mW cm−2 at a concentration of 0.05 mg/mL. The ZnPc-ZnO NHX conjugates produced the best antimicrobial results. , Original publication is available at http://dx.doi.org/10.1016/j.molstruc.2015.06.088
- Full Text: false
Effects of differently shaped silver nanoparticles on the photophysics of pyridylsulfanyl-substituted phthalocyanines
- D'Souza, Sarah, Mashazi, Philani N, Britton, Jonathan, Nyokong, Tebello
- Authors: D'Souza, Sarah , Mashazi, Philani N , Britton, Jonathan , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193564 , vital:45348 , xlink:href="https://doi.org/10.1016/j.poly.2015.06.038"
- Description: This paper reports on the photophysical behavior of (2-pyridylsulfanyl)phthalocyaninato zinc(II) and 2,9(10),16(17),23(24)-tetra-(2-pyridylsulfanyl)phthalocyaninato zinc(II) in the presence of differently shaped silver nanoparticles (nanospheres, nanotriangles and nanoflowers). The presence of shaped nanoparticles increased both triplet quantum yields and lifetimes of the tetra-substituted mercaptopyridine zinc phthalocyanine in DMSO. It is apparent from this work that the shape of the silver nanoparticle used is of little consequence in influencing photophysical behavior of the phthalocyanines.
- Full Text:
- Date Issued: 2015
- Authors: D'Souza, Sarah , Mashazi, Philani N , Britton, Jonathan , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193564 , vital:45348 , xlink:href="https://doi.org/10.1016/j.poly.2015.06.038"
- Description: This paper reports on the photophysical behavior of (2-pyridylsulfanyl)phthalocyaninato zinc(II) and 2,9(10),16(17),23(24)-tetra-(2-pyridylsulfanyl)phthalocyaninato zinc(II) in the presence of differently shaped silver nanoparticles (nanospheres, nanotriangles and nanoflowers). The presence of shaped nanoparticles increased both triplet quantum yields and lifetimes of the tetra-substituted mercaptopyridine zinc phthalocyanine in DMSO. It is apparent from this work that the shape of the silver nanoparticle used is of little consequence in influencing photophysical behavior of the phthalocyanines.
- Full Text:
- Date Issued: 2015
Effects of ZnO nanohexagons and nanorods on the fluorescence behavior of metallophthalocyanines
- D'Souza, Sarah, Moeno, Sharon, Nyokong, Tebello
- Authors: D'Souza, Sarah , Moeno, Sharon , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189741 , vital:44927 , xlink:href="https://doi.org/10.1016/j.poly.2014.09.012"
- Description: This paper looks at the fluorescence behavior of zinc phthalocyanines: 2,(3),9(10),16(17),23(24)-tetrakis- (mercaptoacetic acid phthalocyaninato) zinc(II) (ZnTMAAPc), 2,(3),9(10),16(17),23(24)-tetrakis-(mercaptopropanoic acid phthalocyaninato) zinc(II) (ZnTMPAPc) and (OH)AlPcSmix (the latter contains a mixture of the di-, tri- and tetra-sulfonated derivatives with an average of three sulfonated groups per molecule) in the presence of ZnO nanoparticles. Fluorescence lifetimes of Pc complexes generally decreased in the presence of ZnO nanoparticles, with generally longer lifetimes for ZnO nanohexagons compared to ZnO nanorods.
- Full Text:
- Date Issued: 2015
- Authors: D'Souza, Sarah , Moeno, Sharon , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189741 , vital:44927 , xlink:href="https://doi.org/10.1016/j.poly.2014.09.012"
- Description: This paper looks at the fluorescence behavior of zinc phthalocyanines: 2,(3),9(10),16(17),23(24)-tetrakis- (mercaptoacetic acid phthalocyaninato) zinc(II) (ZnTMAAPc), 2,(3),9(10),16(17),23(24)-tetrakis-(mercaptopropanoic acid phthalocyaninato) zinc(II) (ZnTMPAPc) and (OH)AlPcSmix (the latter contains a mixture of the di-, tri- and tetra-sulfonated derivatives with an average of three sulfonated groups per molecule) in the presence of ZnO nanoparticles. Fluorescence lifetimes of Pc complexes generally decreased in the presence of ZnO nanoparticles, with generally longer lifetimes for ZnO nanohexagons compared to ZnO nanorods.
- Full Text:
- Date Issued: 2015
Transformation adaptation: developing a framework for donor organisation support of climate change adaptation in resource poor communities
- Authors: Dada, Rehana
- Date: 2015
- Subjects: Climatic changes , Human beings -- Effect of climate on , Acclimatization
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/4158 , vital:20560
- Description: Poor communities already face severe challenges in meeting their basic needs, whether because of poor income opportunities, inadequate service delivery, or degraded ecosystems that can no longer support the needs of people. Non profit organisations who provide support for development are also challenged by financial restrictions and social and political structures that prevent or limit project development. Climate change is understood to have the most severe impact on the most vulnerable communities and sectors of communities by reducing the availability and accessibility of basic resources such as water, food and energy, impacting severely on human health and wellbeing, and further reducing the capacity of ecosystems to support livelihoods. This will add a layer of significant new complications to the ability of poor communities to maintain or improve standards of living, and further challenge non profit organisations that support such communitiesAnticipatory adaptation to climate change can reduce some of the impacts of climate change, and also address some key development stresses. This thesis aims to provide a framework that is relevant for supporting adaptation to climate change within the context of resource poor communities in a developing country. Non profit organisations and donor agencies could support success and autonomy in adaptation processes by making provision for locally defined understanding of adaptation, and locally determined processes and programmes. This can be taken further into implementation of programming that addresses local short term development priorities alongside, or as part of long term adaptation work. The research followed a number of steps involving a multitude of techniques including literature review, interviews, a survey, consultation with an expert group, further consultation with stakeholders, and a final electronic review. Its outcome is a strategy that can be used to support climate change adaptation in resource poor communities. A definition for adaptation is proposed as an interpretation of adaptation that is relevant in this context. The intended end goal of adaptation as defined in this research is a better form of development that : supports a harmonious and respectful relationship between humans and their natural resource base; averts further destructive global change or at the very least prevents it from becoming unmanageable; and manages the impacts of past and ongoing destructive change so that there is lowest possible loss of natural, human, or cultural resources. The term transformative adaptation emerged from the research processes to describe adaptation to climate change that concurrently addresses development challenges, is grounded in community development aspirations, integrates programming work across multiple thematic areas and approaches, and addresses the causes of climate change within adaptation interventions. The following broad guidelines are used to inform programming within the framework of transformative adaptation : Human communities are faced with an enormous challenge resulting from global change and sociopolitical injustices; Well planned anticipatory adaptation can limit exposure and vulnerability to at least some of the projected impacts of climate change; Adaptation to climate change incorporates a reduction of vulnerability to underlying development stresses, alongside a reduction of vulnerability to specific climate change stresses; Existing development work forms the foundation for adaptation interventions, acknowledging the interdependence of social, natural and economic systems and the need to maintain their health; Adaptation decision making is community based, and acknowledges that resource poor communities are best placed to establish their own development needs, drive implementation of interventions in own spaces, and identify own limits to adaptation; Adaptation work incorporates mitigation objectives so that the causes of climate change are addressed as part of the strategy for coping with climate change; Adaptation programming acknowledges the strong interlinkages between, and integrates work across, the thematic areas of water security, food sovereignty, energy security, land security, human wellbeing and livelihood diversity; Adaptation uses a broad set of approaches that spans research, knowledge sharing, advocacy, and investment in technology and infrastructure; There is flexibility in project design and implementation to allow room for experimentation with new concepts, and also to change design as knowledge, understanding, and geophysical, biophysical and sociopolitical conditions change.
- Full Text:
- Date Issued: 2015
- Authors: Dada, Rehana
- Date: 2015
- Subjects: Climatic changes , Human beings -- Effect of climate on , Acclimatization
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/4158 , vital:20560
- Description: Poor communities already face severe challenges in meeting their basic needs, whether because of poor income opportunities, inadequate service delivery, or degraded ecosystems that can no longer support the needs of people. Non profit organisations who provide support for development are also challenged by financial restrictions and social and political structures that prevent or limit project development. Climate change is understood to have the most severe impact on the most vulnerable communities and sectors of communities by reducing the availability and accessibility of basic resources such as water, food and energy, impacting severely on human health and wellbeing, and further reducing the capacity of ecosystems to support livelihoods. This will add a layer of significant new complications to the ability of poor communities to maintain or improve standards of living, and further challenge non profit organisations that support such communitiesAnticipatory adaptation to climate change can reduce some of the impacts of climate change, and also address some key development stresses. This thesis aims to provide a framework that is relevant for supporting adaptation to climate change within the context of resource poor communities in a developing country. Non profit organisations and donor agencies could support success and autonomy in adaptation processes by making provision for locally defined understanding of adaptation, and locally determined processes and programmes. This can be taken further into implementation of programming that addresses local short term development priorities alongside, or as part of long term adaptation work. The research followed a number of steps involving a multitude of techniques including literature review, interviews, a survey, consultation with an expert group, further consultation with stakeholders, and a final electronic review. Its outcome is a strategy that can be used to support climate change adaptation in resource poor communities. A definition for adaptation is proposed as an interpretation of adaptation that is relevant in this context. The intended end goal of adaptation as defined in this research is a better form of development that : supports a harmonious and respectful relationship between humans and their natural resource base; averts further destructive global change or at the very least prevents it from becoming unmanageable; and manages the impacts of past and ongoing destructive change so that there is lowest possible loss of natural, human, or cultural resources. The term transformative adaptation emerged from the research processes to describe adaptation to climate change that concurrently addresses development challenges, is grounded in community development aspirations, integrates programming work across multiple thematic areas and approaches, and addresses the causes of climate change within adaptation interventions. The following broad guidelines are used to inform programming within the framework of transformative adaptation : Human communities are faced with an enormous challenge resulting from global change and sociopolitical injustices; Well planned anticipatory adaptation can limit exposure and vulnerability to at least some of the projected impacts of climate change; Adaptation to climate change incorporates a reduction of vulnerability to underlying development stresses, alongside a reduction of vulnerability to specific climate change stresses; Existing development work forms the foundation for adaptation interventions, acknowledging the interdependence of social, natural and economic systems and the need to maintain their health; Adaptation decision making is community based, and acknowledges that resource poor communities are best placed to establish their own development needs, drive implementation of interventions in own spaces, and identify own limits to adaptation; Adaptation work incorporates mitigation objectives so that the causes of climate change are addressed as part of the strategy for coping with climate change; Adaptation programming acknowledges the strong interlinkages between, and integrates work across, the thematic areas of water security, food sovereignty, energy security, land security, human wellbeing and livelihood diversity; Adaptation uses a broad set of approaches that spans research, knowledge sharing, advocacy, and investment in technology and infrastructure; There is flexibility in project design and implementation to allow room for experimentation with new concepts, and also to change design as knowledge, understanding, and geophysical, biophysical and sociopolitical conditions change.
- Full Text:
- Date Issued: 2015
Teachers’ experiences in identifying learners with learning barriers in a Full Service School
- Authors: Dakada, Alinda
- Date: 2015
- Subjects: Inclusive education Learning disabilities -- South Africa -- Eastern Cape Teaching -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10353/6147 , vital:29495
- Description: This study investigates teachers‟ experiences in identifying learners with learning barriers in one primary school in the East London District. It focuses on diversity and inclusive education as well as practices and procedures within the school. This is a phenomenological study conceptualized in terms of social constructivism(Leatherman, 2007), Kurt Lewin‟s Field Theory(Neill, 2004) and ecological systems theory(Maddock, 2000).The literature review encompasses four focal points: conceptualisation of inclusive education, inclusive education in South Africa, policy implementation, and lessons learned from inclusive education implementation both internationally and in South Africa. A qualitative research method is employed in this study through the use of semistructured interviews and observations. The findings are analysed using content analysis. The key findings of this might help the teachers working in full service or mainstream schools to have a good understanding and a sense of what diversity and inclusive education entails. The findings might attempt to examine how educators manage inclusion in the classroom, their competencies and the strategies they need in order to be competent inclusive teachers. Recommendations are developed that point to how practices could be put in place to facilitate an effective implementation strategy for the development of an inclusive education system.
- Full Text:
- Date Issued: 2015
- Authors: Dakada, Alinda
- Date: 2015
- Subjects: Inclusive education Learning disabilities -- South Africa -- Eastern Cape Teaching -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10353/6147 , vital:29495
- Description: This study investigates teachers‟ experiences in identifying learners with learning barriers in one primary school in the East London District. It focuses on diversity and inclusive education as well as practices and procedures within the school. This is a phenomenological study conceptualized in terms of social constructivism(Leatherman, 2007), Kurt Lewin‟s Field Theory(Neill, 2004) and ecological systems theory(Maddock, 2000).The literature review encompasses four focal points: conceptualisation of inclusive education, inclusive education in South Africa, policy implementation, and lessons learned from inclusive education implementation both internationally and in South Africa. A qualitative research method is employed in this study through the use of semistructured interviews and observations. The findings are analysed using content analysis. The key findings of this might help the teachers working in full service or mainstream schools to have a good understanding and a sense of what diversity and inclusive education entails. The findings might attempt to examine how educators manage inclusion in the classroom, their competencies and the strategies they need in order to be competent inclusive teachers. Recommendations are developed that point to how practices could be put in place to facilitate an effective implementation strategy for the development of an inclusive education system.
- Full Text:
- Date Issued: 2015
A business model for medical subspecialty training in South Africa
- Dalmeyer, Johannes Paulus Franciscus
- Authors: Dalmeyer, Johannes Paulus Franciscus
- Date: 2015
- Subjects: Health care teams -- Training of -- South Africa , Medical care -- Needs assessment -- South Africa , Evidence-based medicine -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/3508 , vital:20437
- Description: The shortage of healthcare workers and doctors in the developing world compared to the developed world is a problem, and will continue to be so, due to the continual migration of qualified professionals and the inability of the state to remedy these shortfalls. A shortage of healthcare workers and specialist doctors will seriously hamper the Government’s National Health Insurance (NHI) plan, as well as the sustainability of the private health care sector. In addition, the duration of medical training in South Africa is exceptionally long. The three major hospital groups and other private corporates have over the last number of years taken limited initiative to fund education projects in conjunction with the academic institutions. However, these projects have been poorly focused and have been managed in an unstructured and detached manner. There is a desire from the private sector to get involved in these projects on a much larger scale through more formalised structures. Given this background, the primary objective of this research is to develop a business model for medical subspecialty training to complement the current academic subspecialty training in South Africa. A trial model for training subspecialists in reproductive medicine was developed as a first attempt to address the threatening shortages and training duration. This trial programme is the basis of this research. A two-phased process was used in collecting data. In Phase 1 data was collected from stakeholder groups. The results of this survey assisted in generating variables to include in the measuring instrument for the survey in Phase 2. In Phase 2 the perceptions and expectations of sub-specialists (reproductive subspecialists and cardiologists) regarding sub-specialty training was collected. The results of the demographic variables confirm the aging profile of subspecialist and the need to ensure succession. The results further showed that cardiologists and reproductive subspecialist expectations of the training of subspecialists are very similar except for their expectations on the training duration. Reproductive subspecialist respondents agreed more than cardiology subspecialist respondents that the training duration is too long. The biggest gap between perceptions and expectations is also with the factor training. The results showed that the expectations of subspecialists are not met for training. From these results a business model for the training of medical subspecialists is proposed. This proposed business model can play a complementary role to the existing state controlled system and form the bases of Public Private Partnerships (PPP) in medical training. This proposed business model will fit a developing country were the focus is on primary healthcare, with financial and capacity constraints. The proposed model would require role players to bring about change to accommodate a larger scale Public Private Partnership (PPP) to ensure the implementation of the model. The proposed decentralised business model for training subspecialists would allow the trainee subspecialist to practise as a specialist thus maintaining an acceptable income, and enable an expedited completion and lead to a wider dissemination of medical expertise that can be delivered in a wider national foot print. It further will provide for a structured Public Private Partnership.
- Full Text:
- Date Issued: 2015
- Authors: Dalmeyer, Johannes Paulus Franciscus
- Date: 2015
- Subjects: Health care teams -- Training of -- South Africa , Medical care -- Needs assessment -- South Africa , Evidence-based medicine -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/3508 , vital:20437
- Description: The shortage of healthcare workers and doctors in the developing world compared to the developed world is a problem, and will continue to be so, due to the continual migration of qualified professionals and the inability of the state to remedy these shortfalls. A shortage of healthcare workers and specialist doctors will seriously hamper the Government’s National Health Insurance (NHI) plan, as well as the sustainability of the private health care sector. In addition, the duration of medical training in South Africa is exceptionally long. The three major hospital groups and other private corporates have over the last number of years taken limited initiative to fund education projects in conjunction with the academic institutions. However, these projects have been poorly focused and have been managed in an unstructured and detached manner. There is a desire from the private sector to get involved in these projects on a much larger scale through more formalised structures. Given this background, the primary objective of this research is to develop a business model for medical subspecialty training to complement the current academic subspecialty training in South Africa. A trial model for training subspecialists in reproductive medicine was developed as a first attempt to address the threatening shortages and training duration. This trial programme is the basis of this research. A two-phased process was used in collecting data. In Phase 1 data was collected from stakeholder groups. The results of this survey assisted in generating variables to include in the measuring instrument for the survey in Phase 2. In Phase 2 the perceptions and expectations of sub-specialists (reproductive subspecialists and cardiologists) regarding sub-specialty training was collected. The results of the demographic variables confirm the aging profile of subspecialist and the need to ensure succession. The results further showed that cardiologists and reproductive subspecialist expectations of the training of subspecialists are very similar except for their expectations on the training duration. Reproductive subspecialist respondents agreed more than cardiology subspecialist respondents that the training duration is too long. The biggest gap between perceptions and expectations is also with the factor training. The results showed that the expectations of subspecialists are not met for training. From these results a business model for the training of medical subspecialists is proposed. This proposed business model can play a complementary role to the existing state controlled system and form the bases of Public Private Partnerships (PPP) in medical training. This proposed business model will fit a developing country were the focus is on primary healthcare, with financial and capacity constraints. The proposed model would require role players to bring about change to accommodate a larger scale Public Private Partnership (PPP) to ensure the implementation of the model. The proposed decentralised business model for training subspecialists would allow the trainee subspecialist to practise as a specialist thus maintaining an acceptable income, and enable an expedited completion and lead to a wider dissemination of medical expertise that can be delivered in a wider national foot print. It further will provide for a structured Public Private Partnership.
- Full Text:
- Date Issued: 2015
An Assessment of the Effect of Rotenone on Selected Non-Target Aquatic Fauna
- Dalu, Tatenda, Wasserman, Ryan J, Jordaan, Martine, Froneman, P William, Froneman, Pierre William, Weyl, Olaf L F
- Authors: Dalu, Tatenda , Wasserman, Ryan J , Jordaan, Martine , Froneman, P William , Froneman, Pierre William , Weyl, Olaf L F
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124240 , vital:35579 , https://doi.org/10.1371/journal.pone.0142140.g001
- Description: Rotenone, a naturally occurring ketone, is widely employed for the management of invasive fish species. The use of rotenone poses serious challenges to conservation practitioners due to its impacts on non-target organisms including amphibians and macroinvertebrates. Using laboratory studies, we investigated the effects of different rotenone concentrations (0, 12.5, 25, 37.5, 50, 100 μg L-1) on selected invertebrate groups; Aeshnidae, Belostomatids, Decapods, Ephemeroptera, Pulmonata and zooplankton over a period of 18 hours. Based on field observations and body size, we hypothesized that Ephemeropterans and zooplank- ton would be more susceptible to rote none than Decapods, Belostomatids and snails. Experimental results supported this hypothesis and mortality and behaviour effects varied considerably between taxa, ranging from no effect (crab Potamonuates sidneyi) to 100% mortality (Daphnia pulex and Paradiaptomus lamellatus). Planktonic invertebrates were par- ticularly sensitive to rotenone even at very low concentrations. Future research should investigate the recovery time of invertebrate communities after the application of rotenone and conduct field assessments assessing the longer term effects of rotenone exposure on the population dynamics of those less sensitive organisms.
- Full Text:
- Date Issued: 2015
- Authors: Dalu, Tatenda , Wasserman, Ryan J , Jordaan, Martine , Froneman, P William , Froneman, Pierre William , Weyl, Olaf L F
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124240 , vital:35579 , https://doi.org/10.1371/journal.pone.0142140.g001
- Description: Rotenone, a naturally occurring ketone, is widely employed for the management of invasive fish species. The use of rotenone poses serious challenges to conservation practitioners due to its impacts on non-target organisms including amphibians and macroinvertebrates. Using laboratory studies, we investigated the effects of different rotenone concentrations (0, 12.5, 25, 37.5, 50, 100 μg L-1) on selected invertebrate groups; Aeshnidae, Belostomatids, Decapods, Ephemeroptera, Pulmonata and zooplankton over a period of 18 hours. Based on field observations and body size, we hypothesized that Ephemeropterans and zooplank- ton would be more susceptible to rote none than Decapods, Belostomatids and snails. Experimental results supported this hypothesis and mortality and behaviour effects varied considerably between taxa, ranging from no effect (crab Potamonuates sidneyi) to 100% mortality (Daphnia pulex and Paradiaptomus lamellatus). Planktonic invertebrates were par- ticularly sensitive to rotenone even at very low concentrations. Future research should investigate the recovery time of invertebrate communities after the application of rotenone and conduct field assessments assessing the longer term effects of rotenone exposure on the population dynamics of those less sensitive organisms.
- Full Text:
- Date Issued: 2015
An assessment of chlorophyll-a concentration spatio-temporal variation using Landsat satellite data, in a small tropical reservoir
- Dalu, Tatenda, Dube, Timothy, Froneman, P William, Sachikonye, Mwazvita T B, Clegg, Bruce W, Nhiwatiwa, Tamuka
- Authors: Dalu, Tatenda , Dube, Timothy , Froneman, P William , Sachikonye, Mwazvita T B , Clegg, Bruce W , Nhiwatiwa, Tamuka
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68042 , vital:29189 , https://doi.org/10.1080/10106049.2015.1027292
- Description: Publisher version , Traditional approaches to monitoring aquatic systems are often limited by the need for data collection which often is time-consuming, expensive and non-continuous. The aim of the study was to map the spatio-temporal chlorophyll-a concentration changes in Malilangwe Reservoir, Zimbabwe as an indicator of phytoplankton biomass and trophic state when the reservoir was full (year 2000) and at its lowest capacity (year 2011), using readily available Landsat multispectral images. Medium-spatial resolution (30 m) Landsat multispectral Thematic Mapper TM 5 and ETM+ images for May to December 1999–2000 and 2010–2011 were used to derive chlorophyll-a concentrations. In situ measured chlorophyll-a and total suspended solids (TSS) concentrations for 2011 were employed to validate the Landsat chlorophyll-a and TSS estimates. The study results indicate that Landsat-derived chlorophyll-a and TSS estimates were comparable with field measurements. There was a considerable wet vs. dry season differences in total chlorophyll-a concentration, Secchi disc depth, TSS and turbidity within the reservoir. Using Permutational multivariate analyses of variance (PERMANOVA) analysis, there were significant differences (p < 0.0001) for chlorophyll-a concentration among sites, months and years whereas TSS was significant during the study months (p < 0.05). A strong positive significant correlation among both predicted TSS vs. chlorophyll-a and measured vs. predicted chlorophyll-a and TSS concentrations as well as an inverse relationship between reservoir chlorophyll-a concentrations and water level were found (p < 0.001 in all cases). In conclusion, total chlorophyll-a concentration in Malilangwe Reservoir was successfully derived from Landsat remote sensing data suggesting that the Landsat sensor is suitable for real-time monitoring over relatively short timescales and for small reservoirs. Satellite data can allow for surveying of chlorophyll-a concentration in aquatic ecosystems, thus, providing invaluable data in data scarce (limited on site ground measurements) environments.
- Full Text: false
- Date Issued: 2015
- Authors: Dalu, Tatenda , Dube, Timothy , Froneman, P William , Sachikonye, Mwazvita T B , Clegg, Bruce W , Nhiwatiwa, Tamuka
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68042 , vital:29189 , https://doi.org/10.1080/10106049.2015.1027292
- Description: Publisher version , Traditional approaches to monitoring aquatic systems are often limited by the need for data collection which often is time-consuming, expensive and non-continuous. The aim of the study was to map the spatio-temporal chlorophyll-a concentration changes in Malilangwe Reservoir, Zimbabwe as an indicator of phytoplankton biomass and trophic state when the reservoir was full (year 2000) and at its lowest capacity (year 2011), using readily available Landsat multispectral images. Medium-spatial resolution (30 m) Landsat multispectral Thematic Mapper TM 5 and ETM+ images for May to December 1999–2000 and 2010–2011 were used to derive chlorophyll-a concentrations. In situ measured chlorophyll-a and total suspended solids (TSS) concentrations for 2011 were employed to validate the Landsat chlorophyll-a and TSS estimates. The study results indicate that Landsat-derived chlorophyll-a and TSS estimates were comparable with field measurements. There was a considerable wet vs. dry season differences in total chlorophyll-a concentration, Secchi disc depth, TSS and turbidity within the reservoir. Using Permutational multivariate analyses of variance (PERMANOVA) analysis, there were significant differences (p < 0.0001) for chlorophyll-a concentration among sites, months and years whereas TSS was significant during the study months (p < 0.05). A strong positive significant correlation among both predicted TSS vs. chlorophyll-a and measured vs. predicted chlorophyll-a and TSS concentrations as well as an inverse relationship between reservoir chlorophyll-a concentrations and water level were found (p < 0.001 in all cases). In conclusion, total chlorophyll-a concentration in Malilangwe Reservoir was successfully derived from Landsat remote sensing data suggesting that the Landsat sensor is suitable for real-time monitoring over relatively short timescales and for small reservoirs. Satellite data can allow for surveying of chlorophyll-a concentration in aquatic ecosystems, thus, providing invaluable data in data scarce (limited on site ground measurements) environments.
- Full Text: false
- Date Issued: 2015
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.
- Full Text:
- Date Issued: 2015
- 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.
- Full Text:
- Date Issued: 2015
Spatio-temporal variation in the phytobenthos and phytoplankton community structure and composition of particulate matter along a river-estuary continuum assessed using microscopic and stable isotope analyses
- Authors: Dalu, Tatenda
- Date: 2015
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54416 , vital:26563
- Description: Phytoplankton and phytobenthos communities play an important role in lotic systems as primary producers providing essential biomolecules to higher trophic oganisms and are important indicators for environmental or ecological change. In this thesis, field studies (observational and experimental) along a river–estuary continuum were conducted to assess the spatio-temporal variation and development of phytobenthos and phytoplankton communities using a combination of stable isotope and community analyses in a temperate southern African system across four study periods: September (early spring) and November/December (late spring) 2012, and February (summer) and May/June (winter) 2013. Additionally, the sources and composition of the particulate organic matter were also analysed using stable isotope (δ15N and δ13C) analysis. The effects of substrate type and flood occurrence were assessed through experimental studies at an up- and downstream site of the river after a major flood event that occurred between October and November 2012. Common household tiles were used as artificial substrates to study the development/succession of phytobenthos communities after the flood disturbance. Distinct diatom communities were observed between upstream and downstream sites and at each site, community structure changed with time indicating succession. In addition to recording diatom characteristics on three natural substrates, namely; macrophytes, rocks and sediment, artificial substrates observations were also made on three different types of artificial substrates, namely; brick, brown clay and grey clay tiles. The natural (species richness 78) and artificial substrates (sp. richness 93) had different communities with the latter having greater species richness. Common phytobenthos taxa were not restricted to a single substrate but preference was generally high for the artificial substrates, especially brown tiles (mean sp. richness 47). Results of the redundancy analysis (RDA) analysis indicated that ammonium, conductivity, total dissolved solids, salinity, pH, oxygen reduction potential, phosphate and water depth were the major determinants of the phytobenthos composition at the two sites. The spatio–temporal variation of phytoplankton and phytobenthos communities and allochthonous organic matter along the river–estuary continuum was assessed at 8 sites using a combination of community and stable isotope analyses. A total of 178 species belonging to 78 genera were recorded with diatoms being predominant, accounting for 81.9 % of the total abundance. The total chl-a concentration along the river-estuary continuum increased from spring to a high in summer before decreasing to a low in winter. Periphyton communities were observed to be significantly different across sites (p < 0.05) in terms of species richness, abundances and isotopically The high periphytic δ15N values (range 7.9–15.2 ‰) recorded at the downstream sites compared to the pristine upstream sites (δ15N values range 4–7 ‰) suggest nutrient enrichment most likely derived from anthropogenic sources. Overall, our results reveal general patterns of periphyton communities and stable isotopes and provide improved information in the use of periphyton δ15N as an excellent indicator of anthropogenic nitrogen pollution. Ecologists are interested in the factors that control, and the variability in, the contributions of different sources to mixed organic materials traveling through lotic systems. We hypothesized that the source matter fuelling mixed organic pools in a river-estuary continuum varies over space and time, with the upper reaches of a system characterized by allochthonous-dominated material and autochthonous contributions becoming more important in the lower reaches. Samples of the mixed organic pools and allochthonous and autochthonous source materials were collected during the four study periods. The C:N ratios of suspended particulate matter (SPM) collected during summer and winter indicated that the lower reaches of the system had similar organic matter contributions from the freshwater and terrestrial sources. Stable isotope analysis in R revealed that the contributions of autochthonous organic matter were high in SPM along the entire continuum, and aquatic macrophytes were significant contributors to SPM specifically in the upper reaches. The terrestrial leaves made major contributions to the SPM in the middle regions of the system (i.e. downstream sites of the river, particularly in early and late spring). Bulk detritus had large allochthonous matter components in the lower reaches (estuary), and the contributions of aquatic macrophytes and benthic algae to bulk detritus were high (> 50 %) in the upper to middle reaches (river), but low (< 20 %) in the lower reaches (estuary). The current investigation represents the first attempt to assess the validity of the River Continuum Concept (RCC) in a southern African temperate river. The phytoplankton and phytobenthos communities, and chl-a concentration followed a trend similar to that proposed for the river continuum concept (RCC). The middle reaches based on the phytobenthos or phytoplankton communities and chl-a concentrations which were employed as proxies for primary production, were the most productive, while the upper reaches were the least primary productive. The evaluation of organic matter contributions to the SPM and detritus along the river–estuary continuum provided a baseline assessment of the nature and sources of potential food for consumers inhabiting different locations during different times of the year. Incorporating such spatio-temporal variations in SPM and detritus into food web studies will improve our understanding of the flow of carbon through aquatic systems.
- Full Text:
- Date Issued: 2015
- Authors: Dalu, Tatenda
- Date: 2015
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54416 , vital:26563
- Description: Phytoplankton and phytobenthos communities play an important role in lotic systems as primary producers providing essential biomolecules to higher trophic oganisms and are important indicators for environmental or ecological change. In this thesis, field studies (observational and experimental) along a river–estuary continuum were conducted to assess the spatio-temporal variation and development of phytobenthos and phytoplankton communities using a combination of stable isotope and community analyses in a temperate southern African system across four study periods: September (early spring) and November/December (late spring) 2012, and February (summer) and May/June (winter) 2013. Additionally, the sources and composition of the particulate organic matter were also analysed using stable isotope (δ15N and δ13C) analysis. The effects of substrate type and flood occurrence were assessed through experimental studies at an up- and downstream site of the river after a major flood event that occurred between October and November 2012. Common household tiles were used as artificial substrates to study the development/succession of phytobenthos communities after the flood disturbance. Distinct diatom communities were observed between upstream and downstream sites and at each site, community structure changed with time indicating succession. In addition to recording diatom characteristics on three natural substrates, namely; macrophytes, rocks and sediment, artificial substrates observations were also made on three different types of artificial substrates, namely; brick, brown clay and grey clay tiles. The natural (species richness 78) and artificial substrates (sp. richness 93) had different communities with the latter having greater species richness. Common phytobenthos taxa were not restricted to a single substrate but preference was generally high for the artificial substrates, especially brown tiles (mean sp. richness 47). Results of the redundancy analysis (RDA) analysis indicated that ammonium, conductivity, total dissolved solids, salinity, pH, oxygen reduction potential, phosphate and water depth were the major determinants of the phytobenthos composition at the two sites. The spatio–temporal variation of phytoplankton and phytobenthos communities and allochthonous organic matter along the river–estuary continuum was assessed at 8 sites using a combination of community and stable isotope analyses. A total of 178 species belonging to 78 genera were recorded with diatoms being predominant, accounting for 81.9 % of the total abundance. The total chl-a concentration along the river-estuary continuum increased from spring to a high in summer before decreasing to a low in winter. Periphyton communities were observed to be significantly different across sites (p < 0.05) in terms of species richness, abundances and isotopically The high periphytic δ15N values (range 7.9–15.2 ‰) recorded at the downstream sites compared to the pristine upstream sites (δ15N values range 4–7 ‰) suggest nutrient enrichment most likely derived from anthropogenic sources. Overall, our results reveal general patterns of periphyton communities and stable isotopes and provide improved information in the use of periphyton δ15N as an excellent indicator of anthropogenic nitrogen pollution. Ecologists are interested in the factors that control, and the variability in, the contributions of different sources to mixed organic materials traveling through lotic systems. We hypothesized that the source matter fuelling mixed organic pools in a river-estuary continuum varies over space and time, with the upper reaches of a system characterized by allochthonous-dominated material and autochthonous contributions becoming more important in the lower reaches. Samples of the mixed organic pools and allochthonous and autochthonous source materials were collected during the four study periods. The C:N ratios of suspended particulate matter (SPM) collected during summer and winter indicated that the lower reaches of the system had similar organic matter contributions from the freshwater and terrestrial sources. Stable isotope analysis in R revealed that the contributions of autochthonous organic matter were high in SPM along the entire continuum, and aquatic macrophytes were significant contributors to SPM specifically in the upper reaches. The terrestrial leaves made major contributions to the SPM in the middle regions of the system (i.e. downstream sites of the river, particularly in early and late spring). Bulk detritus had large allochthonous matter components in the lower reaches (estuary), and the contributions of aquatic macrophytes and benthic algae to bulk detritus were high (> 50 %) in the upper to middle reaches (river), but low (< 20 %) in the lower reaches (estuary). The current investigation represents the first attempt to assess the validity of the River Continuum Concept (RCC) in a southern African temperate river. The phytoplankton and phytobenthos communities, and chl-a concentration followed a trend similar to that proposed for the river continuum concept (RCC). The middle reaches based on the phytobenthos or phytoplankton communities and chl-a concentrations which were employed as proxies for primary production, were the most productive, while the upper reaches were the least primary productive. The evaluation of organic matter contributions to the SPM and detritus along the river–estuary continuum provided a baseline assessment of the nature and sources of potential food for consumers inhabiting different locations during different times of the year. Incorporating such spatio-temporal variations in SPM and detritus into food web studies will improve our understanding of the flow of carbon through aquatic systems.
- Full Text:
- Date Issued: 2015
An Assessment of the Effect of Rotenone on Selected Non-Target Aquatic Fauna: Reflections on Henri Lefebre, Urban Theory and the Politics of Scale
- Dalu, Tatenda, Wasserman, Ryan J, Jordaan, Martine, Froneman, Pierre William
- Authors: Dalu, Tatenda , Wasserman, Ryan J , Jordaan, Martine , Froneman, Pierre William
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70425 , vital:29654 , https://doi.org/10.1371/journal.pone.0142140
- Description: Rotenone, a naturally occurring ketone, is widely employed for the management of invasive fish species. The use of rotenone poses serious challenges to conservation practitioners due to its impacts on non-target organisms including amphibians and macroinvertebrates. Using laboratory studies, we investigated the effects of different rotenone concentrations (0,12.5, 25, 37.5, 50, 100 μg L-1) on selected invertebrate groups; Aeshnidae, Belostomatids, Decapods, Ephemeroptera, Pulmonata and zooplankton over a period of 18 hours. Based on field observations and body size, we hypothesized that Ephemeropterans and zooplankton would be more susceptible to rotenone than Decapods, Belostomatids and snails. Experimental results supported this hypothesis and mortality and behaviour effects varied considerably between taxa, ranging from no effect (crab Potamonuates sidneyi) to 100% mortality (Daphnia pulex and Paradiaptomus lamellatus). Planktonic invertebrates were particularly sensitive to rotenone even at very low concentrations. Future research should investigate the recovery time of invertebrate communities after the application of rotenone and conduct field assessments assessing the longer term effects of rotenone exposure on the population dynamics of those less sensitive organisms.
- Full Text:
- Date Issued: 2015
- Authors: Dalu, Tatenda , Wasserman, Ryan J , Jordaan, Martine , Froneman, Pierre William
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70425 , vital:29654 , https://doi.org/10.1371/journal.pone.0142140
- Description: Rotenone, a naturally occurring ketone, is widely employed for the management of invasive fish species. The use of rotenone poses serious challenges to conservation practitioners due to its impacts on non-target organisms including amphibians and macroinvertebrates. Using laboratory studies, we investigated the effects of different rotenone concentrations (0,12.5, 25, 37.5, 50, 100 μg L-1) on selected invertebrate groups; Aeshnidae, Belostomatids, Decapods, Ephemeroptera, Pulmonata and zooplankton over a period of 18 hours. Based on field observations and body size, we hypothesized that Ephemeropterans and zooplankton would be more susceptible to rotenone than Decapods, Belostomatids and snails. Experimental results supported this hypothesis and mortality and behaviour effects varied considerably between taxa, ranging from no effect (crab Potamonuates sidneyi) to 100% mortality (Daphnia pulex and Paradiaptomus lamellatus). Planktonic invertebrates were particularly sensitive to rotenone even at very low concentrations. Future research should investigate the recovery time of invertebrate communities after the application of rotenone and conduct field assessments assessing the longer term effects of rotenone exposure on the population dynamics of those less sensitive organisms.
- Full Text:
- Date Issued: 2015
Assessment of water quality based on diatom indices in a small temperate river system, Kowie River, South Africa
- Dalu, Tatenda, Bere, Taurai, Froneman, P William
- Authors: Dalu, Tatenda , Bere, Taurai , Froneman, P William
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123896 , vital:35514 , http://dx.doi.org/10.4314/wsa.v42i2.02
- Description: This study aimed to assess the impact of land use patterns on water quality and benthic diatom community structure and to test the applicability of diatom indices developed in other regions of the world to a small temperate southern African river system. Sampling was conducted at eight study sites along the length of the river on four separate occasions. Multivariate data analyses were performed on the diatom community dataset to specify the main gradients of floristic variation and to detect and visualize similarities in diatom samples in relation to land-use patterns within the catchment. One hundred and twelve (112) diatom species belonging to 36 genera were recorded during the study. Canonical correspondence analysis (CCA) demonstrated that variations in the benthic diatom community structure were best explained by ammonium, nitrate, conductivity, pH, temperature, resistivity and water flow. OMNIDIA was used for calculation of selected diatom water quality indices. A number of the indices, e.g., the trophic diatom index (TDI), eutrophication/pollution index and biological index of water quality (BIWQ), either under- or over-estimated the water quality of the system. With few exceptions, there were no significant correlations (p> 0.05) between the diatom indices’ values and the nutrient variables. The absence of any significant correlations between the diatom indices’ values and selected physico-chemical variables suggests that indices developed in other regions of the world may not be suitable for temperate southern African rivers.
- Full Text:
- Date Issued: 2016
- Authors: Dalu, Tatenda , Bere, Taurai , Froneman, P William
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123896 , vital:35514 , http://dx.doi.org/10.4314/wsa.v42i2.02
- Description: This study aimed to assess the impact of land use patterns on water quality and benthic diatom community structure and to test the applicability of diatom indices developed in other regions of the world to a small temperate southern African river system. Sampling was conducted at eight study sites along the length of the river on four separate occasions. Multivariate data analyses were performed on the diatom community dataset to specify the main gradients of floristic variation and to detect and visualize similarities in diatom samples in relation to land-use patterns within the catchment. One hundred and twelve (112) diatom species belonging to 36 genera were recorded during the study. Canonical correspondence analysis (CCA) demonstrated that variations in the benthic diatom community structure were best explained by ammonium, nitrate, conductivity, pH, temperature, resistivity and water flow. OMNIDIA was used for calculation of selected diatom water quality indices. A number of the indices, e.g., the trophic diatom index (TDI), eutrophication/pollution index and biological index of water quality (BIWQ), either under- or over-estimated the water quality of the system. With few exceptions, there were no significant correlations (p> 0.05) between the diatom indices’ values and the nutrient variables. The absence of any significant correlations between the diatom indices’ values and selected physico-chemical variables suggests that indices developed in other regions of the world may not be suitable for temperate southern African rivers.
- Full Text:
- Date Issued: 2016
An assessment of the effect of rotenone on selected non-target aquatic fauna:
- Dalu, Tatenda, Wasserman, Ryan J, Jordaan, Martine, Froneman, P William, Weyl, Olaf L F
- Authors: Dalu, Tatenda , Wasserman, Ryan J , Jordaan, Martine , Froneman, P William , Weyl, Olaf L F
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143247 , vital:38214 , https://doi.org/10.1371/journal.pone.0142140
- Description: Rotenone, a naturally occurring ketone, is widely employed for the management of invasive fish species. The use of rotenone poses serious challenges to conservation practitioners due to its impacts on non-target organisms including amphibians and macroinvertebrates. Using laboratory studies, we investigated the effects of different rotenone concentrations (0, 12.5, 25, 37.5, 50, 100 μg L-1) on selected invertebrate groups; Aeshnidae, Belostomatids, Decapods, Ephemeroptera, Pulmonata and zooplankton over a period of 18 hours. Based on field observations and body size, we hypothesized that Ephemeropterans and zooplankton would be more susceptible to rotenone than Decapods, Belostomatids and snails.
- Full Text:
- Date Issued: 2015
- Authors: Dalu, Tatenda , Wasserman, Ryan J , Jordaan, Martine , Froneman, P William , Weyl, Olaf L F
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143247 , vital:38214 , https://doi.org/10.1371/journal.pone.0142140
- Description: Rotenone, a naturally occurring ketone, is widely employed for the management of invasive fish species. The use of rotenone poses serious challenges to conservation practitioners due to its impacts on non-target organisms including amphibians and macroinvertebrates. Using laboratory studies, we investigated the effects of different rotenone concentrations (0, 12.5, 25, 37.5, 50, 100 μg L-1) on selected invertebrate groups; Aeshnidae, Belostomatids, Decapods, Ephemeroptera, Pulmonata and zooplankton over a period of 18 hours. Based on field observations and body size, we hypothesized that Ephemeropterans and zooplankton would be more susceptible to rotenone than Decapods, Belostomatids and snails.
- Full Text:
- Date Issued: 2015
Feeding ecology, residency patterns and migration dynamics of bull sharks (Carcharhinus leucas) in the southwest Indian Ocean
- Authors: Daly, Ryan
- Date: 2015
- Subjects: Bull shark -- Ecology , Bull shark -- Feeding and feeds
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5924 , http://hdl.handle.net/10962/d1017802
- Description: Bull sharks (Carcharhinus leucas) are globally distributed top predators that play an important ecological role within coastal marine communities. However, little is known about how the spatial and temporal scales of their habitat use are associated with their ecological role. In this study, a population of sub-adult and adult bull sharks were investigated within a remote subtropical marine community in the southwest Indian Ocean off the coast of southern Mozambique. The main objectives of the study were to test a minimally invasive remote biopsy sampling method; to investigate the feeding ecology of bull sharks; and to investigate the temporal and spatial scales of bull shark residency patterns and migration dynamics. Biopsy tests on free-swimming bull sharks showed that the devised sampling technique provided a minimally invasive and consistent method (biopsy retention rate = 87%) to obtain muscle tissue samples sufficiently large enough (310±78mg, mean ± SD) for stable isotope analysis. Results from the stable isotope analysis showed that adult bull sharks appeared to exhibit a shift towards consistentlyhigher trophic level prey from an expanded foraging range compared to sub-adults, possibly due to increased mobility linked with size. Additionally, bull sharks had significantly broader niche widths compared to top predatory teleost assemblages with a wide and enriched range of δ13C values relative to the local marine community, suggesting that they forage over broad spatial scales along the east coast of southern Africa. Results from the passive acoustic telemetry investigation, conducted over a period between 10 and 22 months, supported these findings showing that the majority of tagged adult sharksexhibited temporally and spatially variable residency patterns interspersed with migration events. Ten individuals undertook coastal migrations that ranged between 433 and 709km (mean = 533km) with eight of these sharks returning to the study site. During migration, individuals exhibited rates of movement between 2 and 59km.d-1 (mean = 17.58km.d-1) and were recorded travelling annual distances of between 450 and 3760km (mean = 1163km). These findings suggest that adult bull sharks are not the sedentary species once thought to be but rather, consistently move over broad spatial scales on the east coast of southern Africa and play an important predatory role shaping and linking ecological processes within the southwest Indian Ocean.
- Full Text:
- Date Issued: 2015
- Authors: Daly, Ryan
- Date: 2015
- Subjects: Bull shark -- Ecology , Bull shark -- Feeding and feeds
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5924 , http://hdl.handle.net/10962/d1017802
- Description: Bull sharks (Carcharhinus leucas) are globally distributed top predators that play an important ecological role within coastal marine communities. However, little is known about how the spatial and temporal scales of their habitat use are associated with their ecological role. In this study, a population of sub-adult and adult bull sharks were investigated within a remote subtropical marine community in the southwest Indian Ocean off the coast of southern Mozambique. The main objectives of the study were to test a minimally invasive remote biopsy sampling method; to investigate the feeding ecology of bull sharks; and to investigate the temporal and spatial scales of bull shark residency patterns and migration dynamics. Biopsy tests on free-swimming bull sharks showed that the devised sampling technique provided a minimally invasive and consistent method (biopsy retention rate = 87%) to obtain muscle tissue samples sufficiently large enough (310±78mg, mean ± SD) for stable isotope analysis. Results from the stable isotope analysis showed that adult bull sharks appeared to exhibit a shift towards consistentlyhigher trophic level prey from an expanded foraging range compared to sub-adults, possibly due to increased mobility linked with size. Additionally, bull sharks had significantly broader niche widths compared to top predatory teleost assemblages with a wide and enriched range of δ13C values relative to the local marine community, suggesting that they forage over broad spatial scales along the east coast of southern Africa. Results from the passive acoustic telemetry investigation, conducted over a period between 10 and 22 months, supported these findings showing that the majority of tagged adult sharksexhibited temporally and spatially variable residency patterns interspersed with migration events. Ten individuals undertook coastal migrations that ranged between 433 and 709km (mean = 533km) with eight of these sharks returning to the study site. During migration, individuals exhibited rates of movement between 2 and 59km.d-1 (mean = 17.58km.d-1) and were recorded travelling annual distances of between 450 and 3760km (mean = 1163km). These findings suggest that adult bull sharks are not the sedentary species once thought to be but rather, consistently move over broad spatial scales on the east coast of southern Africa and play an important predatory role shaping and linking ecological processes within the southwest Indian Ocean.
- Full Text:
- Date Issued: 2015
The challenges of the child support grant as a poverty alleviation strategy
- Authors: Damba, Ntombethemba
- Date: 2015
- Subjects: Economic assistance, Domestic -- South Africa -- Uitenhage , Income maintenance programs -- South Africa -- Uitenhage , Social security -- South Africa -- Uitenhage
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/6193 , vital:21048
- Description: South Africa is a democratic country since 1994 and transformation brought policies that aimed to address the inequalities and poverty situation countrywide. During apartheid era the existence of social assistance was more focused on minority group. Hence the eroded social inequality cannot be ignored as poverty takes its toll in our communities. It was the previously termed state maintenance grant that was phased out with the introduction of Child support grant (CSG). The purpose of CSG was to reduce child poverty; however a long list of challenges regarding the aims and objectives of the CSG surfaced. This study was about the challenges of child support grant as poverty alleviation strategy in waNobuhle community in Uitenhage. The purpose of the study was also to investigate the value CSG adds in the beneficiaries’ lives in terms of poverty alleviation and what is mostly hindering the CSG from alleviating poverty. The research design for the study could be classified as mixed designs which include qualitative and quantitative approach, taking a form of action research. A sample of 30 participants was drawn from SASSA beneficiaries. The sampling method for the study was purposive, which is a non-probability sampling. Semi structured questionnaires and semi structured interviews were utilized to collect data and the data collected was analysed thematically and descriptive statistics analysis was undertaken as well. Questionnaires to collect data from the thirty (30) CSG beneficiaries’ from KwaNobuhle community and semi structured interviews was undertaken. The most important findings that emerged from the study were that participants appeared to have a clear understanding of the fact that CSG represented a government strategy to support children, fight poverty and uplift the standard of living for the poor. However, majority of the participants were not satisfied with CSG as poverty alleviation strategy, participant’s wants government to increase the amount of CSG and to create employment opportunities. The CSG was pointed as inadequate due to the fact that all family members of the beneficiaries are dependent on the CSG. The conclusion drawn was that CSG paid to KwaNobuhle beneficiaries seemed to be achieving their aims even though the CSG is announced to be inadequate, employment is a necessity and the gap between departments serving the community. The findings of the study are discussed as suggestions to SASSA and the Department of Social development.
- Full Text:
- Date Issued: 2015
- Authors: Damba, Ntombethemba
- Date: 2015
- Subjects: Economic assistance, Domestic -- South Africa -- Uitenhage , Income maintenance programs -- South Africa -- Uitenhage , Social security -- South Africa -- Uitenhage
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/6193 , vital:21048
- Description: South Africa is a democratic country since 1994 and transformation brought policies that aimed to address the inequalities and poverty situation countrywide. During apartheid era the existence of social assistance was more focused on minority group. Hence the eroded social inequality cannot be ignored as poverty takes its toll in our communities. It was the previously termed state maintenance grant that was phased out with the introduction of Child support grant (CSG). The purpose of CSG was to reduce child poverty; however a long list of challenges regarding the aims and objectives of the CSG surfaced. This study was about the challenges of child support grant as poverty alleviation strategy in waNobuhle community in Uitenhage. The purpose of the study was also to investigate the value CSG adds in the beneficiaries’ lives in terms of poverty alleviation and what is mostly hindering the CSG from alleviating poverty. The research design for the study could be classified as mixed designs which include qualitative and quantitative approach, taking a form of action research. A sample of 30 participants was drawn from SASSA beneficiaries. The sampling method for the study was purposive, which is a non-probability sampling. Semi structured questionnaires and semi structured interviews were utilized to collect data and the data collected was analysed thematically and descriptive statistics analysis was undertaken as well. Questionnaires to collect data from the thirty (30) CSG beneficiaries’ from KwaNobuhle community and semi structured interviews was undertaken. The most important findings that emerged from the study were that participants appeared to have a clear understanding of the fact that CSG represented a government strategy to support children, fight poverty and uplift the standard of living for the poor. However, majority of the participants were not satisfied with CSG as poverty alleviation strategy, participant’s wants government to increase the amount of CSG and to create employment opportunities. The CSG was pointed as inadequate due to the fact that all family members of the beneficiaries are dependent on the CSG. The conclusion drawn was that CSG paid to KwaNobuhle beneficiaries seemed to be achieving their aims even though the CSG is announced to be inadequate, employment is a necessity and the gap between departments serving the community. The findings of the study are discussed as suggestions to SASSA and the Department of Social development.
- Full Text:
- Date Issued: 2015
The trophic ecology of the endangered endemic Barau's Petrel (Pterodroma baraui) from Reunion Island, south-western Indian Ocean
- Authors: Danckwerts, Daniel Keith
- Date: 2015
- Subjects: Petrels -- Réunion , Pterodroma baraui , Ecology -- Réunion
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5925 , http://hdl.handle.net/10962/d1017803
- Description: Réunion is the only tropical island that supports two endemic gadfly petrels. Population modelling has indicated that the current threats to the Barau’s Petrel (Pterodroma baraui) may drive it to extinction; this fate is almost definite for the Mascarene Petrel (Pseudobulweria aterrima). Management interventions have therefore been implemented, but conservation potential is handicapped since virtually nothing is known about the former species’ at-sea biology. Thus, following numerous recommendations, this study aimed to combine stomach content, stable isotope, and fatty acid analyses so to provide new information on the at-sea ecology of Barau’s Petrel. Breeding colonies were repeatedly visited over the same season and samples gathered from adults, fledglings, and downy chicks. Stomach contents consisted mostly of accumulated cephalopod beaks whereas structures from fishes, molluscs, arthropods, and crustaceans were less frequently encountered. Fatty acid profiles of blood varied greatly among individuals and the lowincidences of monounsaturated and n-3 fatty acids discounted fish as an important dietary component. δ¹⁵N of blood indicated a niche between the fourth and fifth trophic levels, which proposes that these birds scavenge to a greater degree than other sympatric seabirds and suggests that adults are also reliant on their endogenous reserves during breeding. δ¹³C values confirmed the migratory behaviour of adults since birds returning from the non-breeding grounds were enriched relative to individuals sampled through the breeding period. Significant intra-breeding season variations in δ13C were also observed, which matched this species’ patterns of habitat use as have recently described. These results collectively indicate an opportunistic behaviour, which implies some degree of resilience against shifts in prey availability/accessibility, and suggest that this species’ reproduction isdependent on distant foraging areas. This breeding strategy is synonymous with great vulnerability as over-investing into a single breeding episode may jeopardize future survival and fecundity. Thus, in light of environmental conditions that are becoming increasingly more susceptible to dramatic changes, the birds could rather be prioritising adult survival, over reproductive output. Further work is obviously necessary and should benefit from databases of fatty acid profiles and isotope signatures of potential prey species.
- Full Text:
- Date Issued: 2015
- Authors: Danckwerts, Daniel Keith
- Date: 2015
- Subjects: Petrels -- Réunion , Pterodroma baraui , Ecology -- Réunion
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5925 , http://hdl.handle.net/10962/d1017803
- Description: Réunion is the only tropical island that supports two endemic gadfly petrels. Population modelling has indicated that the current threats to the Barau’s Petrel (Pterodroma baraui) may drive it to extinction; this fate is almost definite for the Mascarene Petrel (Pseudobulweria aterrima). Management interventions have therefore been implemented, but conservation potential is handicapped since virtually nothing is known about the former species’ at-sea biology. Thus, following numerous recommendations, this study aimed to combine stomach content, stable isotope, and fatty acid analyses so to provide new information on the at-sea ecology of Barau’s Petrel. Breeding colonies were repeatedly visited over the same season and samples gathered from adults, fledglings, and downy chicks. Stomach contents consisted mostly of accumulated cephalopod beaks whereas structures from fishes, molluscs, arthropods, and crustaceans were less frequently encountered. Fatty acid profiles of blood varied greatly among individuals and the lowincidences of monounsaturated and n-3 fatty acids discounted fish as an important dietary component. δ¹⁵N of blood indicated a niche between the fourth and fifth trophic levels, which proposes that these birds scavenge to a greater degree than other sympatric seabirds and suggests that adults are also reliant on their endogenous reserves during breeding. δ¹³C values confirmed the migratory behaviour of adults since birds returning from the non-breeding grounds were enriched relative to individuals sampled through the breeding period. Significant intra-breeding season variations in δ13C were also observed, which matched this species’ patterns of habitat use as have recently described. These results collectively indicate an opportunistic behaviour, which implies some degree of resilience against shifts in prey availability/accessibility, and suggest that this species’ reproduction isdependent on distant foraging areas. This breeding strategy is synonymous with great vulnerability as over-investing into a single breeding episode may jeopardize future survival and fecundity. Thus, in light of environmental conditions that are becoming increasingly more susceptible to dramatic changes, the birds could rather be prioritising adult survival, over reproductive output. Further work is obviously necessary and should benefit from databases of fatty acid profiles and isotope signatures of potential prey species.
- Full Text:
- Date Issued: 2015
Views of HIV and AIDS amongst rural secondary school youth: an exploratory study
- Daniels, Brendon Mara Laurence
- Authors: Daniels, Brendon Mara Laurence
- Date: 2015
- Subjects: Sexually transmitted diseases -- Study and teaching Communicable diseases -- Prevention High school students
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10948/11460 , vital:26928
- Description: The HIV and AIDS epidemic continues to affect communities worldwide particularly so in South Africa. Youth, also the so-called Coloured youth, continue to remain at risk of infection, in spite of having been exposed to information about HIV and AIDS. This study explores the views of Coloured secondary school youth in a rural town in the Eastern Cape, on HIV and AIDS. Fifteen secondary school learners, both boys and girls, from Grades 10 to 12 were purposively selected. This qualitative study, framed within an interpretivist paradigm, draws on a phenomenological methodology. The data was generated from using drawing and focus group interviews and analysed using thematic analysis. The research adhered to ethical principles and trustworthiness was ensured. Constructivism and Bronfenbrenner’s bio-ecological systems theory were used to frame the study and to make meaning of the findings. In response to the primary research question, What views do Coloured youth attending a secondary school in a rural town have of HIV and AIDS?, five themes emerged, namely: individuals spread HIV, impoverished family life increases youth vulnerability to HIV, youth under pressure from peers knowingly engage in risky behaviour, misconceptions fuel the epidemic, and HIV and AIDS “captures the community in its net”. Drawing on the findings and in response to the secondary research question, What guidelines can be developed to assist educators to facilitate learners taking action against the spread of HIV and AIDS?, several guidelines were developed. They suggest that teachers should use participatory pedagogies to engage secondary school learners when teaching HIV and AIDS, build self-esteem in their learners, assist learners in dealing with peer pressure, engage learners in erasing misconceptions, and enable learners to break free from being “caught in the net” of HIV and AIDS. Collectively these guidelines could enable learners to take action in protecting themselves and their community against the spread of the HI virus. The study concludes that the views that Coloured secondary school learners from a rural town have about HIV and AIDS show their awareness of the realities of the epidemic affecting the individual, the family, the school and their community. They have constructed their views of HIV and AIDS in a way which shows their understanding of the complexities of the epidemic.
- Full Text:
- Date Issued: 2015
- Authors: Daniels, Brendon Mara Laurence
- Date: 2015
- Subjects: Sexually transmitted diseases -- Study and teaching Communicable diseases -- Prevention High school students
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10948/11460 , vital:26928
- Description: The HIV and AIDS epidemic continues to affect communities worldwide particularly so in South Africa. Youth, also the so-called Coloured youth, continue to remain at risk of infection, in spite of having been exposed to information about HIV and AIDS. This study explores the views of Coloured secondary school youth in a rural town in the Eastern Cape, on HIV and AIDS. Fifteen secondary school learners, both boys and girls, from Grades 10 to 12 were purposively selected. This qualitative study, framed within an interpretivist paradigm, draws on a phenomenological methodology. The data was generated from using drawing and focus group interviews and analysed using thematic analysis. The research adhered to ethical principles and trustworthiness was ensured. Constructivism and Bronfenbrenner’s bio-ecological systems theory were used to frame the study and to make meaning of the findings. In response to the primary research question, What views do Coloured youth attending a secondary school in a rural town have of HIV and AIDS?, five themes emerged, namely: individuals spread HIV, impoverished family life increases youth vulnerability to HIV, youth under pressure from peers knowingly engage in risky behaviour, misconceptions fuel the epidemic, and HIV and AIDS “captures the community in its net”. Drawing on the findings and in response to the secondary research question, What guidelines can be developed to assist educators to facilitate learners taking action against the spread of HIV and AIDS?, several guidelines were developed. They suggest that teachers should use participatory pedagogies to engage secondary school learners when teaching HIV and AIDS, build self-esteem in their learners, assist learners in dealing with peer pressure, engage learners in erasing misconceptions, and enable learners to break free from being “caught in the net” of HIV and AIDS. Collectively these guidelines could enable learners to take action in protecting themselves and their community against the spread of the HI virus. The study concludes that the views that Coloured secondary school learners from a rural town have about HIV and AIDS show their awareness of the realities of the epidemic affecting the individual, the family, the school and their community. They have constructed their views of HIV and AIDS in a way which shows their understanding of the complexities of the epidemic.
- Full Text:
- Date Issued: 2015
An evaluation of treasury oversight and budget under-spending in selected Eastern Cape Provincial Departments
- Authors: Daniels, Nokuthula
- Date: 2015
- Subjects: Expenditures, Public , Legislative auditing -- South Africa -- Eastern Cape , Fiscal year -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: http://hdl.handle.net/10948/3265 , vital:20418
- Description: The investigation of this study focused on the ability of provincial government departments in South Africa to spend allocated revenues on activities adequately, with a direct bearing on social and economic development. The research presents an analysis of two selected Eastern Cape Provincial Government departments’ expenditure for a three-year timeframe (the fiscal years from 2009–2012), with a focus on the oversight role played by the Provincial Planning and Treasury department in instilling fiscal discipline in the provinces, and the potentially detrimental effect of under-spending on provincial service delivery. Among other things mentioned and discussed are, firstly, the fiscal policy; secondly, the funding of provincial departments; thirdly, the role and responsibilities of the Provincial Planning and Treasury department. The study adopted a qualitative methodology which focussed on the perspective of the insider who has experienced first-hand the activities or procedures under scrutiny in the selected provincial departments. Further, the qualitative researcher believed that first-hand experience provides the most meaningful data. In support of this, the respondents were asked twenty-two questions, the first five of which were based on the need to understand their personal particulars. A semi-structured questionnaire was distributed to 43 officials and 22 of those questionnaires were returned.
- Full Text:
- Date Issued: 2015
- Authors: Daniels, Nokuthula
- Date: 2015
- Subjects: Expenditures, Public , Legislative auditing -- South Africa -- Eastern Cape , Fiscal year -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: http://hdl.handle.net/10948/3265 , vital:20418
- Description: The investigation of this study focused on the ability of provincial government departments in South Africa to spend allocated revenues on activities adequately, with a direct bearing on social and economic development. The research presents an analysis of two selected Eastern Cape Provincial Government departments’ expenditure for a three-year timeframe (the fiscal years from 2009–2012), with a focus on the oversight role played by the Provincial Planning and Treasury department in instilling fiscal discipline in the provinces, and the potentially detrimental effect of under-spending on provincial service delivery. Among other things mentioned and discussed are, firstly, the fiscal policy; secondly, the funding of provincial departments; thirdly, the role and responsibilities of the Provincial Planning and Treasury department. The study adopted a qualitative methodology which focussed on the perspective of the insider who has experienced first-hand the activities or procedures under scrutiny in the selected provincial departments. Further, the qualitative researcher believed that first-hand experience provides the most meaningful data. In support of this, the respondents were asked twenty-two questions, the first five of which were based on the need to understand their personal particulars. A semi-structured questionnaire was distributed to 43 officials and 22 of those questionnaires were returned.
- Full Text:
- Date Issued: 2015
Women's perceptions regarding financial planning with specific reference to investment
- Authors: Dao, Thi Anh Thu
- Date: 2015
- Subjects: Women -- South Africa -- Nelson Mandela Bay Municipality -- Finance, Personal , Investments -- South Africa -- Nelson Mandela Bay Municipality , Financial planning industry -- South Africa -- Nelson Mandela Bay Municipality
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:9332 , http://hdl.handle.net/10948/d1021185
- Description: Investment planning (as one of the key components of financial planning) is seen as an important solution to investment problems and challenges. Previous research however indicated that compare to men, women are not as confident and knowledgeable about financial and investment matters. As a result, women do not conduct investment planning until it is often too late and when they are confronted with a financial crisis or a life predicament such as a divorce or death. Given the lack of research attention focusing on women's perceptions of financial and investment planning in South Africa, and in particular the Eastern Cape, the objective of this research is to investigate the factors that influence women‟s Perceived successful investment planning in the Nelson Mandela Bay area. After conducting a comprehensive literature study, seven factors (independent variables) namely Values, Attitudes, Time horizon, Personal life cycle, Risks and Returns, Investment Knowledge, were identified as influencing the Perceived successful investment planning (dependent variable) of women. Various hypotheses were formulated to be tested in the empirical investigation. The validity and reliability of the measuring instrument were tested among 207 respondents. The Exploratory Factor Analysis, as well as the Cronbach‟s alpha coeffient analysis, revelead that Investment knowledge, Personal life cycle and Values are important factors that influence the women‟s Perceived successful investment planning. As a result of these analyses, the hypotheses had to be reformulated. In order to establish whether correlations existed between the various factors investigated in this study, Pearson Product Moment Correlation Coefficients were calculated. Positive correlations were found between all the variables, except between Values and Personal life cycle and between Values and Perceived successful investment planning. To analyse the association in which the effects of the independent variables (Investment knowledge, Personal life cycle and Values) have on the dependent variable (Perceived successful investment planning) of this study, multiple regression analysis was conducted. Only one independent variable emerged as having a significant influence on Perceived successful investment planning of women, namely Investment knowledge. In order to investigate the influence of the various demographic variables on the dependent variable, an Analysis of Variance was performed. No significant differences were found between the selected demographic variables, namely Age, Ethnic group, Marital status, Education and Investment experience and the independent variables or dependent variable of this study. By investigating the influence of women‟s Perceived successful investment planning, this study has added to the body of knowledge of both financial and investment planning. Based on the empirical results of this study, several recommendations have been made in an attempt to assist women to make better investment decisions and manage their investment planning more effectively.
- Full Text:
- Date Issued: 2015
- Authors: Dao, Thi Anh Thu
- Date: 2015
- Subjects: Women -- South Africa -- Nelson Mandela Bay Municipality -- Finance, Personal , Investments -- South Africa -- Nelson Mandela Bay Municipality , Financial planning industry -- South Africa -- Nelson Mandela Bay Municipality
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:9332 , http://hdl.handle.net/10948/d1021185
- Description: Investment planning (as one of the key components of financial planning) is seen as an important solution to investment problems and challenges. Previous research however indicated that compare to men, women are not as confident and knowledgeable about financial and investment matters. As a result, women do not conduct investment planning until it is often too late and when they are confronted with a financial crisis or a life predicament such as a divorce or death. Given the lack of research attention focusing on women's perceptions of financial and investment planning in South Africa, and in particular the Eastern Cape, the objective of this research is to investigate the factors that influence women‟s Perceived successful investment planning in the Nelson Mandela Bay area. After conducting a comprehensive literature study, seven factors (independent variables) namely Values, Attitudes, Time horizon, Personal life cycle, Risks and Returns, Investment Knowledge, were identified as influencing the Perceived successful investment planning (dependent variable) of women. Various hypotheses were formulated to be tested in the empirical investigation. The validity and reliability of the measuring instrument were tested among 207 respondents. The Exploratory Factor Analysis, as well as the Cronbach‟s alpha coeffient analysis, revelead that Investment knowledge, Personal life cycle and Values are important factors that influence the women‟s Perceived successful investment planning. As a result of these analyses, the hypotheses had to be reformulated. In order to establish whether correlations existed between the various factors investigated in this study, Pearson Product Moment Correlation Coefficients were calculated. Positive correlations were found between all the variables, except between Values and Personal life cycle and between Values and Perceived successful investment planning. To analyse the association in which the effects of the independent variables (Investment knowledge, Personal life cycle and Values) have on the dependent variable (Perceived successful investment planning) of this study, multiple regression analysis was conducted. Only one independent variable emerged as having a significant influence on Perceived successful investment planning of women, namely Investment knowledge. In order to investigate the influence of the various demographic variables on the dependent variable, an Analysis of Variance was performed. No significant differences were found between the selected demographic variables, namely Age, Ethnic group, Marital status, Education and Investment experience and the independent variables or dependent variable of this study. By investigating the influence of women‟s Perceived successful investment planning, this study has added to the body of knowledge of both financial and investment planning. Based on the empirical results of this study, several recommendations have been made in an attempt to assist women to make better investment decisions and manage their investment planning more effectively.
- Full Text:
- Date Issued: 2015