Managing an inclusive school: a case study of a pilot school in Swaziland
- Authors: Zimba, Zondani
- Date: 2012
- Subjects: Inclusive education -- Swaziland -- Mbabane Special education -- Swaziland -- Mbabane Learning disabled children -- Education -- Swaziland -- Mbabane Students with disabilities -- Swaziland -- Mbabane School management and organization -- Swaziland -- Mbabane
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1669 , http://hdl.handle.net/10962/d1003552
- Description: Inclusive Education (IE) reflects the values, ethos, and culture of an education system committed to excellence by promoting education opportunities for all learners. IE is about building a more just society and ensuring the right to education for all learners regardless of their individual characteristics or difficulties (UNESCO: 2007). The kingdom of Swaziland has committed itself to high quality basic education which provides equal opportunities for all children and youth. This is evident in the Swaziland National Constitution (2006). To promote Education for All (EFA) as stated in the constitution, an IE Policy has been developed and a draft policy is in place. The programme has been operational since 2006. There are nine pilot schools and four teachers from each school who have been trained on how to handle pupils with disabilities. The programme will be rolled out to 608 primary schools by 2015. In this research, the goal was to investigate how a School Management Board responds to the challenges of managing an Inclusive School. This research is a qualitative interpretive case study based in one of the pilot schools in Mbabane in Swaziland. The study used document analysis, semi‐structured interviews and focus groups to collect data. The study revealed that the school has done much in accommodating IE as there are changes in management structures and approaches, organizational culture and operating procedures. On the other hand, there are still significant challenges such as a lack of knowledge of inclusion and negativity on the part of learners and parents. Other challenges include inadequate training for educators and lack of suitable infrastructure. The study concludes by recommending improved staff development programmes, infrastructure upgrades, acquiring appropriate teaching and learning resources and employing multidisciplinary personnel.
- Full Text:
- Date Issued: 2012
- Authors: Zimba, Zondani
- Date: 2012
- Subjects: Inclusive education -- Swaziland -- Mbabane Special education -- Swaziland -- Mbabane Learning disabled children -- Education -- Swaziland -- Mbabane Students with disabilities -- Swaziland -- Mbabane School management and organization -- Swaziland -- Mbabane
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1669 , http://hdl.handle.net/10962/d1003552
- Description: Inclusive Education (IE) reflects the values, ethos, and culture of an education system committed to excellence by promoting education opportunities for all learners. IE is about building a more just society and ensuring the right to education for all learners regardless of their individual characteristics or difficulties (UNESCO: 2007). The kingdom of Swaziland has committed itself to high quality basic education which provides equal opportunities for all children and youth. This is evident in the Swaziland National Constitution (2006). To promote Education for All (EFA) as stated in the constitution, an IE Policy has been developed and a draft policy is in place. The programme has been operational since 2006. There are nine pilot schools and four teachers from each school who have been trained on how to handle pupils with disabilities. The programme will be rolled out to 608 primary schools by 2015. In this research, the goal was to investigate how a School Management Board responds to the challenges of managing an Inclusive School. This research is a qualitative interpretive case study based in one of the pilot schools in Mbabane in Swaziland. The study used document analysis, semi‐structured interviews and focus groups to collect data. The study revealed that the school has done much in accommodating IE as there are changes in management structures and approaches, organizational culture and operating procedures. On the other hand, there are still significant challenges such as a lack of knowledge of inclusion and negativity on the part of learners and parents. Other challenges include inadequate training for educators and lack of suitable infrastructure. The study concludes by recommending improved staff development programmes, infrastructure upgrades, acquiring appropriate teaching and learning resources and employing multidisciplinary personnel.
- Full Text:
- Date Issued: 2012
The praxis of responsible investment in South Africa: a holistic case study of Evolution One Fund
- Zaulochnaya Ya-Brouwer, Irina
- Authors: Zaulochnaya Ya-Brouwer, Irina
- Date: 2012
- Subjects: Social responsibility of business -- South Africa Investments -- Moral and ethical aspects -- South Africa Institutional investments -- Moral and ethical aspects -- South Africa Private equity funds -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:778 , http://hdl.handle.net/10962/d1003899
- Description: At the beginning of the 21st century the public interest in environmental and social sustainability, and corporate governance grew exponentially fuelled by recurring ecological and financial crises. The market demand for cleaner production and corporate transparency created opportunities for sustainability entrepreneurs in a variety of industries, including financial markets and investment management. An increasing number of financial institutions across the world now offer ethical or socially responsible products to meet the environmental, social and governance (ESG) aspirations of their clients. In the US, according to the Social Investment Forum (SIF), responsible investment (RI) assets reached US$ 2,29 trillion in 2007 (Mitchell, 2008). The European Sustainable Investment Forum (EuroSIF) estimated that total European SRI assets reached EUR 5 trillion in 2009 (Wheelan, 2010). In June 2011 the International Finance Corporation (IFC) reported that at the end of 2010 professional sustainable investment under management in South Africa approximately equalled US$ 122,6 billion (IFC, 2011:44). The statistics describing the rapid growth in the ESG-type investments are, however, complicated by the variety of names and definitions used to describe this emerging type of investment and a general market uncertainty about what constitutes the practice of RI. The purpose of this case study is to better understand responsible investment principles and practice as seen through the eyes of a South African private equity fund, which specializes in clean technology.
- Full Text:
- Date Issued: 2012
- Authors: Zaulochnaya Ya-Brouwer, Irina
- Date: 2012
- Subjects: Social responsibility of business -- South Africa Investments -- Moral and ethical aspects -- South Africa Institutional investments -- Moral and ethical aspects -- South Africa Private equity funds -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:778 , http://hdl.handle.net/10962/d1003899
- Description: At the beginning of the 21st century the public interest in environmental and social sustainability, and corporate governance grew exponentially fuelled by recurring ecological and financial crises. The market demand for cleaner production and corporate transparency created opportunities for sustainability entrepreneurs in a variety of industries, including financial markets and investment management. An increasing number of financial institutions across the world now offer ethical or socially responsible products to meet the environmental, social and governance (ESG) aspirations of their clients. In the US, according to the Social Investment Forum (SIF), responsible investment (RI) assets reached US$ 2,29 trillion in 2007 (Mitchell, 2008). The European Sustainable Investment Forum (EuroSIF) estimated that total European SRI assets reached EUR 5 trillion in 2009 (Wheelan, 2010). In June 2011 the International Finance Corporation (IFC) reported that at the end of 2010 professional sustainable investment under management in South Africa approximately equalled US$ 122,6 billion (IFC, 2011:44). The statistics describing the rapid growth in the ESG-type investments are, however, complicated by the variety of names and definitions used to describe this emerging type of investment and a general market uncertainty about what constitutes the practice of RI. The purpose of this case study is to better understand responsible investment principles and practice as seen through the eyes of a South African private equity fund, which specializes in clean technology.
- Full Text:
- Date Issued: 2012
Synthetic and bioactivity studies of antiplasmodial and antibacterial marine natural products
- Authors: Young, Ryan Mark
- Date: 2012
- Subjects: Antibacterial agents Marine natural products Marine pharmacology Plasmodium falciparum Staphylococcus aureus Isocyanides Imidazoles
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4378 , http://hdl.handle.net/10962/d1005043
- Description: This thesis is divided into two parts, assessing marine and synthetic compounds active firstly against Plasmodium falciparum (Chapter 3 and 4) and secondly active against methicillin resistant Staphylococcus aureus (MRSA, Chapter 5). In Chapter 3 the synthesis of nine new tricyclic podocarpanes (3.203-3.207 and 3.209-3.212) from the diterpene (+)-manool is described. Initial SAR study of synthetic podocarpanes concluded that the most active compound was a C-13 phenyl substituted podocarpane (3.204, IC₅₀ 6.6 μM). By preparing analogues with varying halogenated substituents on the phenyl ring (3.209-3.212) the antiplasmodial activity was improved (IC₅₀ 1.4 μM), while simultaneously decreasing the haemolysis previously reported for this class of compounds. Inspired by the antiplasmodial activity of Wright and Wattanapiromsakul’s tricycle marine isonitriles (2.16-2.21 and 2.24-2.27) an unsuccessfully attempt was made to convert tertiary alcohol moieties to isonitrile functionalities in compounds 3.188, 3.204-3.207 and 3.209-3.212. Over a decade ago Wright et al. proposed a putative antiplasmodial mechanism of action for marine isonitriles (2.4, 2.9, 2.15, 2.19 and 2.35) and isothiocyanate (2.34) which involved interference in haem detoxification by P. falciparum thus inhibiting the growth of the parasite. In Chapter 4 we describe how we successfully managed to scale down Egan’s β-haematin inhibition assay for the analyses of small quantities of marine natural products as potential β-haematin inhibitors. Our modified assay revealed that the most active antiplasmodial marine isonitrile 2.9 (IC₅₀ 13 nM) showed total β-haematin inhibition while 2.15 (IC₅₀ 81 nM) and 2.19 (IC₅₀ 31 nM) showed partial inhibition at three equivalents relative to haem. Using contempary molecular modelling techniques the charge on the isonitrile functionality was more accurately describe and the modified charge data sets was used to explore docking of marine isonitriles to haem using AutoDock. In Chapter 5 we describe how a lead South African marine bisindole MRSA pyruvate kinase inhibitor (5.8) was discovered in collaboration with colleagues at the University of British Columbia (UBC) and how this discovery inspired us to design a synthetic route to the dibrominated bisindole, isobromotopsentin (5.20) in an attempt to increase the bioactivity displayed by 5.8. We devised a fast and high yielding synthetic route using microwave assited organic synthesis. We first tested this synthesis using simple aryl glyoxals (5.27-5.32) as precursors to synthesize biphenylimidazoles (5.21-5.26), which later allowed us to synthesize the ascidian natural product 5.111. This method was sucessfully extended to the synthesis of deoxytopsentin (5.33) from an N-Boc protected indole methyl ketone (5.89). We subsequently were able to effectively remove the carbamate protection via thermal decomposition by heating the protected bisindole imidazole (5.90) in a microwave reactor for 5 min under argon. The synthesis of 5.20 resulted in an inseparable mixture of monoprotected and totally deprotected topsentin products, and due to time constraints we were not able to optimise this synthesis. Nonetheless our synthesis of the marine natural product 5.33 which was faster and higher yielding than previously reported routes could be extended to the synthesis of other topsentin bisindoles (5.138-5.140). Work towards this goal continues in our laboratory.
- Full Text:
- Date Issued: 2012
- Authors: Young, Ryan Mark
- Date: 2012
- Subjects: Antibacterial agents Marine natural products Marine pharmacology Plasmodium falciparum Staphylococcus aureus Isocyanides Imidazoles
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4378 , http://hdl.handle.net/10962/d1005043
- Description: This thesis is divided into two parts, assessing marine and synthetic compounds active firstly against Plasmodium falciparum (Chapter 3 and 4) and secondly active against methicillin resistant Staphylococcus aureus (MRSA, Chapter 5). In Chapter 3 the synthesis of nine new tricyclic podocarpanes (3.203-3.207 and 3.209-3.212) from the diterpene (+)-manool is described. Initial SAR study of synthetic podocarpanes concluded that the most active compound was a C-13 phenyl substituted podocarpane (3.204, IC₅₀ 6.6 μM). By preparing analogues with varying halogenated substituents on the phenyl ring (3.209-3.212) the antiplasmodial activity was improved (IC₅₀ 1.4 μM), while simultaneously decreasing the haemolysis previously reported for this class of compounds. Inspired by the antiplasmodial activity of Wright and Wattanapiromsakul’s tricycle marine isonitriles (2.16-2.21 and 2.24-2.27) an unsuccessfully attempt was made to convert tertiary alcohol moieties to isonitrile functionalities in compounds 3.188, 3.204-3.207 and 3.209-3.212. Over a decade ago Wright et al. proposed a putative antiplasmodial mechanism of action for marine isonitriles (2.4, 2.9, 2.15, 2.19 and 2.35) and isothiocyanate (2.34) which involved interference in haem detoxification by P. falciparum thus inhibiting the growth of the parasite. In Chapter 4 we describe how we successfully managed to scale down Egan’s β-haematin inhibition assay for the analyses of small quantities of marine natural products as potential β-haematin inhibitors. Our modified assay revealed that the most active antiplasmodial marine isonitrile 2.9 (IC₅₀ 13 nM) showed total β-haematin inhibition while 2.15 (IC₅₀ 81 nM) and 2.19 (IC₅₀ 31 nM) showed partial inhibition at three equivalents relative to haem. Using contempary molecular modelling techniques the charge on the isonitrile functionality was more accurately describe and the modified charge data sets was used to explore docking of marine isonitriles to haem using AutoDock. In Chapter 5 we describe how a lead South African marine bisindole MRSA pyruvate kinase inhibitor (5.8) was discovered in collaboration with colleagues at the University of British Columbia (UBC) and how this discovery inspired us to design a synthetic route to the dibrominated bisindole, isobromotopsentin (5.20) in an attempt to increase the bioactivity displayed by 5.8. We devised a fast and high yielding synthetic route using microwave assited organic synthesis. We first tested this synthesis using simple aryl glyoxals (5.27-5.32) as precursors to synthesize biphenylimidazoles (5.21-5.26), which later allowed us to synthesize the ascidian natural product 5.111. This method was sucessfully extended to the synthesis of deoxytopsentin (5.33) from an N-Boc protected indole methyl ketone (5.89). We subsequently were able to effectively remove the carbamate protection via thermal decomposition by heating the protected bisindole imidazole (5.90) in a microwave reactor for 5 min under argon. The synthesis of 5.20 resulted in an inseparable mixture of monoprotected and totally deprotected topsentin products, and due to time constraints we were not able to optimise this synthesis. Nonetheless our synthesis of the marine natural product 5.33 which was faster and higher yielding than previously reported routes could be extended to the synthesis of other topsentin bisindoles (5.138-5.140). Work towards this goal continues in our laboratory.
- Full Text:
- Date Issued: 2012
An investigation of how natural sciences teachers mediate learning of chemical reactions in Grade 9: a case study
- Authors: Xipu, Bukelwa
- Date: 2012
- Subjects: Science -- Study and teaching (Secondary) Science -- Study and teaching (Secondary) -- South Africa -- Eastern Cape Chemical reactions Science teachers -- South Africa -- Eastern Cape Science teachers -- Rating of -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1631 , http://hdl.handle.net/10962/d1003513
- Description: This research study involves two Grade 9 Natural Sciences teachers from two schools in the Lady Frere District of the Eastern Cape. The reason for selecting these two teachers is that in 2009 they, like me, obtained an Advanced Certificate in Education (Science and Maths) from Rhodes University. As a result, we have a good working relationship. Furthermore, both teachers are actively involved in the Natural Sciences curriculum in the District and their schools are not far from the District Office where I work. The principal objective of this study was to investigate how Natural Sciences teachers mediated learning in order to enhance conceptual development and understanding of chemical reactions in Grade 9. It was triggered by the transformation in curriculum in South Africa as well as by my experience of working with Natural Sciences teachers in our rural district. The study is informed by an interpretive paradigm using a qualitative case study approach. The data was gathered by administering analysis of documents, semi-structured interviews, observations, field notes and journals. During the data analysis process, patterns and themes were illuminated using the inductive analysis method. Rich data sets in relation to the main research question on how Natural Sciences teachers mediated learning in order to enhance conceptual development and understanding of chemical reactions in Grade 9 emerged from the analysed data. The conclusions that can be drawn from the study indicate that when teaching chemical reactions, teachers should have adequate content knowledge as well as pedagogical content knowledge. It is thus recommended that teachers consider the prior knowledge of learners, use a variety of teaching and learning approaches including practical activities, to make learning meaningful. The major limitation of this study is that the two selected teachers do not represent the whole population of Grade 9 teachers in the Lady Frere District. Therefore, the findings cannot be generalized to represent the larger population. It is recognised, however, that within the qualitative inquiry, reliability and generalizability play a minor role.
- Full Text:
- Date Issued: 2012
- Authors: Xipu, Bukelwa
- Date: 2012
- Subjects: Science -- Study and teaching (Secondary) Science -- Study and teaching (Secondary) -- South Africa -- Eastern Cape Chemical reactions Science teachers -- South Africa -- Eastern Cape Science teachers -- Rating of -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1631 , http://hdl.handle.net/10962/d1003513
- Description: This research study involves two Grade 9 Natural Sciences teachers from two schools in the Lady Frere District of the Eastern Cape. The reason for selecting these two teachers is that in 2009 they, like me, obtained an Advanced Certificate in Education (Science and Maths) from Rhodes University. As a result, we have a good working relationship. Furthermore, both teachers are actively involved in the Natural Sciences curriculum in the District and their schools are not far from the District Office where I work. The principal objective of this study was to investigate how Natural Sciences teachers mediated learning in order to enhance conceptual development and understanding of chemical reactions in Grade 9. It was triggered by the transformation in curriculum in South Africa as well as by my experience of working with Natural Sciences teachers in our rural district. The study is informed by an interpretive paradigm using a qualitative case study approach. The data was gathered by administering analysis of documents, semi-structured interviews, observations, field notes and journals. During the data analysis process, patterns and themes were illuminated using the inductive analysis method. Rich data sets in relation to the main research question on how Natural Sciences teachers mediated learning in order to enhance conceptual development and understanding of chemical reactions in Grade 9 emerged from the analysed data. The conclusions that can be drawn from the study indicate that when teaching chemical reactions, teachers should have adequate content knowledge as well as pedagogical content knowledge. It is thus recommended that teachers consider the prior knowledge of learners, use a variety of teaching and learning approaches including practical activities, to make learning meaningful. The major limitation of this study is that the two selected teachers do not represent the whole population of Grade 9 teachers in the Lady Frere District. Therefore, the findings cannot be generalized to represent the larger population. It is recognised, however, that within the qualitative inquiry, reliability and generalizability play a minor role.
- Full Text:
- Date Issued: 2012
Design and evaluation of illustrated information leaflets as an educational tool for low-literate asthma patients
- Authors: Wrench, Wendy Merle
- Date: 2012 , 2012-10-08
- Subjects: Asthma -- South Africa -- Study and teaching , Asthmatics -- South Africa -- Education
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3867 , http://hdl.handle.net/10962/d1016236
- Description: Asthma is a chronic non-communicable disease associated with an increase in morbidity, mortality and economic burden. Globally 300 million people have asthma and it is estimated that one in every 250 deaths worldwide are due to asthma. South Africa has the highest asthma prevalence (8.1%) in Africa and the disease is 18th in the top 20 causes of death. Inadequate home management, poor availability of health care, and poor transport and emergency services are recognised as important contributing factors. Patients with a low level of education and limited literacy skills may be unable to understand instructions on frequency and use of asthma medicines, which could result in unintentional non-adherence leading to serious complications and increased health care costs. The aim of this study was to investigate the impact of a tailored educational intervention on low-literate patients with asthma. Objectives to achieve this aim included designing patient information leaflets (PILs) containing information on asthma, management of asthma and asthma therapy, and using the PILs to educate low-literate asthma patients. A before-andafter intervention type design evaluated self-reported selected health-related quality of life measures, self-reported self-efficacy, knowledge of asthma and asthma management, knowledge of the use of metered dose inhalers (MDIs) and MDI technique. The acceptability and understanding of the tailored PILs was also investigated. Two simple, readable PILs containing pictograms were developed in English and then translated into isiXhosa, the home language of the majority of the target population. Various guidelines on the design of health-related information for people with low-literacy were consulted and input on the design was received from health care providers, patients and graphic artists. A pilot study was conducted at a local primary health care (PHC) clinic to evaluate the PILs and final modifications to the PILs were made based on feedback received. For the main study, patients were recruited from the KwaNonqubela PHC clinic in Alexandria in the Eastern Cape, South Africa. Patients were 18 years or older, dependent on public sector health care facilities, diagnosed with asthma, prescribed a MDI (beclomethasone and/or salbutamol) for at least one month and English or isiXhosa-speaking. The exclusion criterion for patients in this study was involvement in any other asthma educational intervention during the period of study. Interviewer-led structured questionnaires were administered to 55 patients at the baseline and follow-up. Data collected include demographics, brief medical history and current asthma medications. Self-efficacy and iii health-related quality of life were assessed. Knowledge of asthma and asthma management was evaluated, and the use of beclomethasone and/or salbutamol metered dose inhalers was assessed. The PIL ‘Understanding asthma and trigger factors of asthma’ formed part of the educational intervention to explain asthma and aspects related to its management. Inhaler technique was evaluated and corrected using the PIL ‘How to use your pump’ together with a demonstration of correct technique by the investigator. Follow-up interviews were conducted approximately four weeks after baseline. PIL acceptability, readability and understanding of each pictogram were investigated at follow-up only. The educational intervention resulted in a significant increase in mean knowledge of asthma from 52.7% at baseline to 75.5% at follow-up. Gender was not associated with knowledge, but there was a significant age effect at baseline only, with the younger patients achieving better knowledge results. In both phases, patients with higher education had improved scores. A significant increase (2.4% to 38.6%) in the number of patients taking the minimum recommended adult dose of beclomethasone was noted but it is a matter of concern that the majority of patients were taking less than this. Patient self-reports suggested a significant increase in adherence, with the number of patients taking beclomethasone daily increasing from 33.3% to 61.3%. Self-reported management and control of asthma improved and this was reflected by the enhanced HRQOL results. MDI technique also improved significantly with an increase in the mean number of correct steps from 4.6 ± 2.2 to 7.9 ± 2.7. Education had a significant effect on MDI technique with more errors associated with lower educational status. There were no significant age or gender effects on the total number of correct steps in either phase. The illustrated PILs were received favourably with the majority of literate patients reporting that they were easy to read. Patients commented positively on the inclusion of pictograms and stated that the pictograms had served as aids in the understanding of asthma, trigger factors of asthma and correct MDI technique. The results of this study show that specially designed illustrated PILs can be an effective tool in educating low-literate patients with asthma. , Adobe Acrobat Pro 11.0.0 Paper Capture Plug-in
- Full Text:
- Date Issued: 2012
- Authors: Wrench, Wendy Merle
- Date: 2012 , 2012-10-08
- Subjects: Asthma -- South Africa -- Study and teaching , Asthmatics -- South Africa -- Education
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3867 , http://hdl.handle.net/10962/d1016236
- Description: Asthma is a chronic non-communicable disease associated with an increase in morbidity, mortality and economic burden. Globally 300 million people have asthma and it is estimated that one in every 250 deaths worldwide are due to asthma. South Africa has the highest asthma prevalence (8.1%) in Africa and the disease is 18th in the top 20 causes of death. Inadequate home management, poor availability of health care, and poor transport and emergency services are recognised as important contributing factors. Patients with a low level of education and limited literacy skills may be unable to understand instructions on frequency and use of asthma medicines, which could result in unintentional non-adherence leading to serious complications and increased health care costs. The aim of this study was to investigate the impact of a tailored educational intervention on low-literate patients with asthma. Objectives to achieve this aim included designing patient information leaflets (PILs) containing information on asthma, management of asthma and asthma therapy, and using the PILs to educate low-literate asthma patients. A before-andafter intervention type design evaluated self-reported selected health-related quality of life measures, self-reported self-efficacy, knowledge of asthma and asthma management, knowledge of the use of metered dose inhalers (MDIs) and MDI technique. The acceptability and understanding of the tailored PILs was also investigated. Two simple, readable PILs containing pictograms were developed in English and then translated into isiXhosa, the home language of the majority of the target population. Various guidelines on the design of health-related information for people with low-literacy were consulted and input on the design was received from health care providers, patients and graphic artists. A pilot study was conducted at a local primary health care (PHC) clinic to evaluate the PILs and final modifications to the PILs were made based on feedback received. For the main study, patients were recruited from the KwaNonqubela PHC clinic in Alexandria in the Eastern Cape, South Africa. Patients were 18 years or older, dependent on public sector health care facilities, diagnosed with asthma, prescribed a MDI (beclomethasone and/or salbutamol) for at least one month and English or isiXhosa-speaking. The exclusion criterion for patients in this study was involvement in any other asthma educational intervention during the period of study. Interviewer-led structured questionnaires were administered to 55 patients at the baseline and follow-up. Data collected include demographics, brief medical history and current asthma medications. Self-efficacy and iii health-related quality of life were assessed. Knowledge of asthma and asthma management was evaluated, and the use of beclomethasone and/or salbutamol metered dose inhalers was assessed. The PIL ‘Understanding asthma and trigger factors of asthma’ formed part of the educational intervention to explain asthma and aspects related to its management. Inhaler technique was evaluated and corrected using the PIL ‘How to use your pump’ together with a demonstration of correct technique by the investigator. Follow-up interviews were conducted approximately four weeks after baseline. PIL acceptability, readability and understanding of each pictogram were investigated at follow-up only. The educational intervention resulted in a significant increase in mean knowledge of asthma from 52.7% at baseline to 75.5% at follow-up. Gender was not associated with knowledge, but there was a significant age effect at baseline only, with the younger patients achieving better knowledge results. In both phases, patients with higher education had improved scores. A significant increase (2.4% to 38.6%) in the number of patients taking the minimum recommended adult dose of beclomethasone was noted but it is a matter of concern that the majority of patients were taking less than this. Patient self-reports suggested a significant increase in adherence, with the number of patients taking beclomethasone daily increasing from 33.3% to 61.3%. Self-reported management and control of asthma improved and this was reflected by the enhanced HRQOL results. MDI technique also improved significantly with an increase in the mean number of correct steps from 4.6 ± 2.2 to 7.9 ± 2.7. Education had a significant effect on MDI technique with more errors associated with lower educational status. There were no significant age or gender effects on the total number of correct steps in either phase. The illustrated PILs were received favourably with the majority of literate patients reporting that they were easy to read. Patients commented positively on the inclusion of pictograms and stated that the pictograms had served as aids in the understanding of asthma, trigger factors of asthma and correct MDI technique. The results of this study show that specially designed illustrated PILs can be an effective tool in educating low-literate patients with asthma. , Adobe Acrobat Pro 11.0.0 Paper Capture Plug-in
- Full Text:
- Date Issued: 2012
Touching Brýnstone
- Authors: Woudstra, Ruth
- Date: 2012
- Subjects: South African fiction (English) -- 21st century , Short stories, South African (English) -- 21st century , South African poetry (English) -- 21st century , Creative writing (Higher education) , Diaries -- Authorship , English language -- Writing
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2504 , http://hdl.handle.net/10962/d1015032
- Description: Touching Brýnstone is the story of Beth, a young journalist who is troubled by misfortunes in her family and work circumstances. In a Pretoria library she is seduced by a book that consoles her and progressively becomes a fetish object. It sparks a journey to Japan, where she arrives to teach English. She is intent on meeting the author, whom she confounds with protagonist and book. This Bildungsroman is an exploration of the complex relationship between inner and outer self, and the struggle towards wholeness. Beth must find a way out of the obsession so that she can return to South Africa with an enriched insight into her shadow self.
- Full Text:
- Date Issued: 2012
- Authors: Woudstra, Ruth
- Date: 2012
- Subjects: South African fiction (English) -- 21st century , Short stories, South African (English) -- 21st century , South African poetry (English) -- 21st century , Creative writing (Higher education) , Diaries -- Authorship , English language -- Writing
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2504 , http://hdl.handle.net/10962/d1015032
- Description: Touching Brýnstone is the story of Beth, a young journalist who is troubled by misfortunes in her family and work circumstances. In a Pretoria library she is seduced by a book that consoles her and progressively becomes a fetish object. It sparks a journey to Japan, where she arrives to teach English. She is intent on meeting the author, whom she confounds with protagonist and book. This Bildungsroman is an exploration of the complex relationship between inner and outer self, and the struggle towards wholeness. Beth must find a way out of the obsession so that she can return to South Africa with an enriched insight into her shadow self.
- Full Text:
- Date Issued: 2012
The role of Hsp90/Hsp70 organising protein (Hop) in the Proliferation, Survival and Migration of Breast Cancer Cells.
- Authors: Willmer, Tarryn
- Date: 2012
- Subjects: Cancer -- Treatment , Heat shock proteins , Cancer cells , Breast -- Cancer
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4130 , http://hdl.handle.net/10962/d1015720
- Description: Hop (the Hsp90/Hsp70 organising protein) is a co-chaperone that acts as an adapter between the major molecular chaperones Hsp90 and Hsp70 during the cellular assembly of the Hsp90 complex. The Hsp90 complex regulates the stability and conformational maturation of a range of important cellular proteins, many of which are deregulated in cancer. In this study, we hypothesised that Hop knockdown inhibits proliferation and migration of cancer cells. We characterised the expression of Hop in cell models of different cancerous status, and provided evidence that Hop was upregulated in tumour cells compared to normal cell counterparts. Using an RNA interference approach, a 60-90% knockdown of Hop was achieved for up to 144 hours in the MDA-MB-231 and Hs578T breast cancer cell lines. Hop knockdown resulted in downregulation of the Hsp90 client proteins, Akt and Stat3, as well as a change in the expression of other Hsp90 co-chaperones, p23, Cdc37 and Aha1, while no change in the levels of Hsp90 or Hsp70 was observed. Silencing of Hop impaired cell proliferation in Hs578T cells but an increase in proliferation in MDA-MB-231, suggesting that the role of Hop in cancer cell proliferation was dependent on type of cancer cell. Hop knockdown in Hs578T and MDA-MB- 231 cells did not lead to any significant changes in the half maximal inhibitory concentrations (IC50) of selected small molecule inhibitors (paclitaxel, geldanamycin and novobiocin) in these cell lines after 72 hours. Hop knockdown cells were however, more sensitive than control cells to the Hsp90 inhibitors geldanamycin and novobiocin at earlier time points and in the presence of the drug transporter inhibitor, verapamil. Hop knockdown caused a decrease in cell migration as measured by the wound healing assay in both Hs578T and MDA-MB-231 cells. Hop was present in purified pseudopodia fractions of migrating cells, and immunofluorescence analysis showed that Hop colocalised with actin at the leading edges of pseudopodia, points of adhesion and at intercellular junctions of cells that have been stimulated to migrate with the chemokine stromal derived factor-1. Hop was able to bind to actin in vitro using actin cosedimentation assays, and silencing of Hop dramatically reduced the capacity of Hs578T cells to form pseudopodia. These results establish a correlation between Hop and actin dynamics, pseudopodia formation and migration in the context of Hop silencing, and collectively suggest that Hop plays a role in cancer cell migration. This study presents experimental evidence for a promising alternative to targeting Hsp90 and Hsp70 chaperones, a novel drug target in cancer therapy.
- Full Text:
- Date Issued: 2012
- Authors: Willmer, Tarryn
- Date: 2012
- Subjects: Cancer -- Treatment , Heat shock proteins , Cancer cells , Breast -- Cancer
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4130 , http://hdl.handle.net/10962/d1015720
- Description: Hop (the Hsp90/Hsp70 organising protein) is a co-chaperone that acts as an adapter between the major molecular chaperones Hsp90 and Hsp70 during the cellular assembly of the Hsp90 complex. The Hsp90 complex regulates the stability and conformational maturation of a range of important cellular proteins, many of which are deregulated in cancer. In this study, we hypothesised that Hop knockdown inhibits proliferation and migration of cancer cells. We characterised the expression of Hop in cell models of different cancerous status, and provided evidence that Hop was upregulated in tumour cells compared to normal cell counterparts. Using an RNA interference approach, a 60-90% knockdown of Hop was achieved for up to 144 hours in the MDA-MB-231 and Hs578T breast cancer cell lines. Hop knockdown resulted in downregulation of the Hsp90 client proteins, Akt and Stat3, as well as a change in the expression of other Hsp90 co-chaperones, p23, Cdc37 and Aha1, while no change in the levels of Hsp90 or Hsp70 was observed. Silencing of Hop impaired cell proliferation in Hs578T cells but an increase in proliferation in MDA-MB-231, suggesting that the role of Hop in cancer cell proliferation was dependent on type of cancer cell. Hop knockdown in Hs578T and MDA-MB- 231 cells did not lead to any significant changes in the half maximal inhibitory concentrations (IC50) of selected small molecule inhibitors (paclitaxel, geldanamycin and novobiocin) in these cell lines after 72 hours. Hop knockdown cells were however, more sensitive than control cells to the Hsp90 inhibitors geldanamycin and novobiocin at earlier time points and in the presence of the drug transporter inhibitor, verapamil. Hop knockdown caused a decrease in cell migration as measured by the wound healing assay in both Hs578T and MDA-MB-231 cells. Hop was present in purified pseudopodia fractions of migrating cells, and immunofluorescence analysis showed that Hop colocalised with actin at the leading edges of pseudopodia, points of adhesion and at intercellular junctions of cells that have been stimulated to migrate with the chemokine stromal derived factor-1. Hop was able to bind to actin in vitro using actin cosedimentation assays, and silencing of Hop dramatically reduced the capacity of Hs578T cells to form pseudopodia. These results establish a correlation between Hop and actin dynamics, pseudopodia formation and migration in the context of Hop silencing, and collectively suggest that Hop plays a role in cancer cell migration. This study presents experimental evidence for a promising alternative to targeting Hsp90 and Hsp70 chaperones, a novel drug target in cancer therapy.
- Full Text:
- Date Issued: 2012
The dispersal of African wild dogs (Lycaon Pictus) from protected areas in the Northern KwaZulu‐Natal Province, South Africa.
- Whittington‐Jones, Brendan Mark
- Authors: Whittington‐Jones, Brendan Mark
- Date: 2012
- Subjects: African wild dog , African wild dog -- Conservation -- South Africa -- KwazuluNatal , African wild dog -- Dispersal -- South Africa -- KwaZulu-Natal , African wild dog -- Effect of human beings on -- South Africa -- KwaZulu Natal
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5893 , http://hdl.handle.net/10962/d1013414
- Description: The number of African wild dogs Lycaon pictus in Northern KwaZulu‐Natal, South Africa has increased substantially over the last six years. This is largely due to a managed metapopulation approach of introductions onto protected areas and private game reserves since 1998. Because of the increasing wild dog population, the likelihood of rural communities surrounding protected areas encountering dispersing wild dogs in northern KwaZulu‐Natal has also increased. Resident wild dog populations currently occur in Hluhluwe‐iMfolozi Park (HiP), Mkhuze Game Reserve (MGR) of Isimangaliso Wetland Park and Thanda Private Game Reserve (TPGR) all of which are bordered by a matrix of natural habitats and human settlements. Thus, land outside these protected areas could be utilized to expand wild dog distribution and provide connectivity between existing resident populations of wild dogs within KwaZulu‐Natal. To investigate the viability of such an approach, Maximum Entropy Modelling (Maxent) was used to characterize habitat niche selection of dispersing wild dogs, and to identify potential dispersal linkages between current wild dog metapopulation reserves. The model was calibrated using 132 location points collected from 2006 until 2009. From 2008 to 2009 I also conducted a survey of 247 community members in tribal authorities bordering HiP and MGR, to understand factors influencing attitudes towards wild dogs. A habitat suitability model with seven predictor variables had an AUC of 0.96 (SD = 0.02) and indicated four variables which best predicted probability of presence for dispersing wild dogs: elevation, road density, land cover and human density. The results suggest that elevation and land cover may be of greater influence for dispersing wild dogs than human density or activity. Elevation was the single most effective variable indicating a higher probability of presence for dispersing wild dogs in lower lying locations; peaking at approximately 200 – 300m a.s.l. Wild dogs also showed a preference for Woodland and Bushland habitats which in KwaZulu‐Natal tend to be found on lower lying topography. A preference for areas of lower human density and a highest probability of presence at road densities of approximately 0.7km/km2 or less would suggest that while wild dogs may show a tendency to avoid areas of high human activity, they can coexist in close proximity to humans. Respondent’s attitudes, knowledge of wild dogs and livestock husbandry were interpreted by the development of a set of indices. Attitudes were positively related to formal education levels and wild dog‐specific education, but were not influenced by demographic factors such as gender, age and employment status. Eighty three percent of respondents believed efforts to protect wild dogs should continue. Respondents with higher numbers of livestock tended to have more positive attitudes towards wild dogs despite generally incurring higher losses to carnivore depredation than those with less livestock. This appears to be because the financial burden of livestock losses to those with fewer livestock is perceived to be a loss of a greater proportion of total financial wealth. The study highlighted the substantial scope for improvement in livestock management. Theft (34 percent), drought (30 percent) and disease (14 percent) were ranked as the greatest problems facing livestock owners while predators were ranked as the greatest problem by only 4 percent of respondents. My findings suggest that wild dogs are generally viewed positively or with ambivalence. Concerns over the potentially increasing threat to livestock, as natural prey numbers outside protected areas decline and wild dogs disperse from natal packs, are likely to be manageable. However, wild dog population expansion within KwaZulu‐Natal will continue to rely on managed core populations on perimeter‐fenced metapopulation reserves with tolerant communities and landowners contributing to the connectivity of isolated reserves. Generation of tolerance can be instilled through continued advocacy and education, supported by conflict mitigation initiatives and rapid response to conflict reports. The implementation of incentive schemes for adjoining private landowners to co‐manage wild dog populations will need to be addressed in conjunction with managed metapopulation practices and law enforcement, to promote range expansion, and reduce potentially lethal edge effects and wild dog‐human conflict.
- Full Text:
- Date Issued: 2012
- Authors: Whittington‐Jones, Brendan Mark
- Date: 2012
- Subjects: African wild dog , African wild dog -- Conservation -- South Africa -- KwazuluNatal , African wild dog -- Dispersal -- South Africa -- KwaZulu-Natal , African wild dog -- Effect of human beings on -- South Africa -- KwaZulu Natal
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5893 , http://hdl.handle.net/10962/d1013414
- Description: The number of African wild dogs Lycaon pictus in Northern KwaZulu‐Natal, South Africa has increased substantially over the last six years. This is largely due to a managed metapopulation approach of introductions onto protected areas and private game reserves since 1998. Because of the increasing wild dog population, the likelihood of rural communities surrounding protected areas encountering dispersing wild dogs in northern KwaZulu‐Natal has also increased. Resident wild dog populations currently occur in Hluhluwe‐iMfolozi Park (HiP), Mkhuze Game Reserve (MGR) of Isimangaliso Wetland Park and Thanda Private Game Reserve (TPGR) all of which are bordered by a matrix of natural habitats and human settlements. Thus, land outside these protected areas could be utilized to expand wild dog distribution and provide connectivity between existing resident populations of wild dogs within KwaZulu‐Natal. To investigate the viability of such an approach, Maximum Entropy Modelling (Maxent) was used to characterize habitat niche selection of dispersing wild dogs, and to identify potential dispersal linkages between current wild dog metapopulation reserves. The model was calibrated using 132 location points collected from 2006 until 2009. From 2008 to 2009 I also conducted a survey of 247 community members in tribal authorities bordering HiP and MGR, to understand factors influencing attitudes towards wild dogs. A habitat suitability model with seven predictor variables had an AUC of 0.96 (SD = 0.02) and indicated four variables which best predicted probability of presence for dispersing wild dogs: elevation, road density, land cover and human density. The results suggest that elevation and land cover may be of greater influence for dispersing wild dogs than human density or activity. Elevation was the single most effective variable indicating a higher probability of presence for dispersing wild dogs in lower lying locations; peaking at approximately 200 – 300m a.s.l. Wild dogs also showed a preference for Woodland and Bushland habitats which in KwaZulu‐Natal tend to be found on lower lying topography. A preference for areas of lower human density and a highest probability of presence at road densities of approximately 0.7km/km2 or less would suggest that while wild dogs may show a tendency to avoid areas of high human activity, they can coexist in close proximity to humans. Respondent’s attitudes, knowledge of wild dogs and livestock husbandry were interpreted by the development of a set of indices. Attitudes were positively related to formal education levels and wild dog‐specific education, but were not influenced by demographic factors such as gender, age and employment status. Eighty three percent of respondents believed efforts to protect wild dogs should continue. Respondents with higher numbers of livestock tended to have more positive attitudes towards wild dogs despite generally incurring higher losses to carnivore depredation than those with less livestock. This appears to be because the financial burden of livestock losses to those with fewer livestock is perceived to be a loss of a greater proportion of total financial wealth. The study highlighted the substantial scope for improvement in livestock management. Theft (34 percent), drought (30 percent) and disease (14 percent) were ranked as the greatest problems facing livestock owners while predators were ranked as the greatest problem by only 4 percent of respondents. My findings suggest that wild dogs are generally viewed positively or with ambivalence. Concerns over the potentially increasing threat to livestock, as natural prey numbers outside protected areas decline and wild dogs disperse from natal packs, are likely to be manageable. However, wild dog population expansion within KwaZulu‐Natal will continue to rely on managed core populations on perimeter‐fenced metapopulation reserves with tolerant communities and landowners contributing to the connectivity of isolated reserves. Generation of tolerance can be instilled through continued advocacy and education, supported by conflict mitigation initiatives and rapid response to conflict reports. The implementation of incentive schemes for adjoining private landowners to co‐manage wild dog populations will need to be addressed in conjunction with managed metapopulation practices and law enforcement, to promote range expansion, and reduce potentially lethal edge effects and wild dog‐human conflict.
- Full Text:
- Date Issued: 2012
"Is more, less?" : insect-insect interactions in a biological control context using water hyacinth as a model
- Weyl, Philip Sebastian Richard
- Authors: Weyl, Philip Sebastian Richard
- Date: 2012
- Subjects: Water hyacinth -- South Africa -- Eastern Cape , Water hyacinth -- Biological control -- South Africa -- Eastern Cape , Insects as biological pest control agents , Miridae -- South Africa -- Eastern Cape , Beetles -- South Africa -- Eastern Cape , Competition (Biology)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5724 , http://hdl.handle.net/10962/d1005410 , Water hyacinth -- South Africa -- Eastern Cape , Water hyacinth -- Biological control -- South Africa -- Eastern Cape , Insects as biological pest control agents , Miridae -- South Africa -- Eastern Cape , Beetles -- South Africa -- Eastern Cape , Competition (Biology)
- Description: Interactions between insects have been shown to be important regulators of population abundances and dynamics as well as drivers of spatial segregation and distribution. These are important aspects of the ecology of insects used in biological control and may have implications for the overall success of a particular programme. In the history of biological control there has been a tendency to release a suite of agents against a weed, which in some cases has increased the level of success, while in others little change has been observed. In most of these cases the implications of increasing the level of complexity of the system is not taken into account and there is little research on the effect of releasing another agent into the system. A brief meta-analysis was done on all the biological control programmes initiated in South Africa. Emphasis was placed on multi-species releases and the effects that overlapping niches were having on the number of agents responsible for the success of a programme. Where overlapping niches were present among agents released the number of agents responsible for success was lower than the number established. Water hyacinth, Eichhornia crassipes (Martius) Solms-Laubach in South Africa has more arthropod agents released against it than anywhere else in the world, yet control has been variable. If the biology and host utilisation of all the agents against water hyacinth is considered, a definite overlap of niches is apparent in at least one life stage of all the agents. Therefore the probability of these insects interacting is high, especially if they are established at the same site in the field. Three of the insects released in South Africa have been selected to investigate possible interactions. They are Neochetina eichhorniae Warner, Neochetina bruchi Hustache and Eccritotarsus catarinensis (Carvalho). Y-tube olfactometer bioassays were used to measure responses of these insects to water hyacinth with prior feeding damage by either conspecifics or heterospecifics. This was done to determine whether olfactory cues played a role in host acceptability and avoidance of conspecifics or heterospecifics. The insects were given a choice between damaged and undamaged plants in various combinations. There was a significant preference for the undamaged plants when given a choice between undamaged and damaged plants. However when the insects were given a choice between two damaged plants there was no discrimination between heterospecific or conspecific damaged plants. This may indicate that there is little or no ecological cost for the insect to share a plant with other insects utilising a similar resource. Insect – insect interactions were investigated in a common garden plot experiment to measure the impact that pairwise combinations of the insect may have on their performance. There was a significant interaction between the mirid E. catarinensis and the weevil N. eichhorniae, with the weevil not performing as well when in combination with the mirid than when alone. Interestingly there was a negative interaction between the two weevil species when in combination, however it was impossible to determine which species was being affected if not both. None of the insects performed significantly better when in combination with another insect. A field study on Wriggleswade Dam in the Eastern Cape, South Africa was initiated to determine whether the relationship between the mirid E. catarinensis and the weevil N. eichhorniae could be determined in the field. The performance of the insects at the different sites in the field suggests that there was an interaction between the agents. This interaction did not limit the establishment of either insect at a site, but it did result in one insect dominating at a site over another. Interactions between the three species of insect tested in this thesis suggest that there are both negative and neutral relationships between them. A basic comparison between the insect performances from 15 sites around the country was done to determine if the spatial segregation observed in the field could be extrapolated to the natural South African situation. The interaction observed between N. eichhorniae and E. catarinensis does seem to extrapolate to the general South African situation where there is definite spatial segregation on a landscape level. The co–occurrence of the two Neochetina weevils at these sites suggests that the negative relationship observed between them in the common garden experiment does not extrapolate to the field. The results from this thesis suggest that the interactions between the agents tested would not limit establishment or have significant ramifications on performance. However, there may be spatial and temporal segregation of these species in the introduced range.
- Full Text:
- Date Issued: 2012
- Authors: Weyl, Philip Sebastian Richard
- Date: 2012
- Subjects: Water hyacinth -- South Africa -- Eastern Cape , Water hyacinth -- Biological control -- South Africa -- Eastern Cape , Insects as biological pest control agents , Miridae -- South Africa -- Eastern Cape , Beetles -- South Africa -- Eastern Cape , Competition (Biology)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5724 , http://hdl.handle.net/10962/d1005410 , Water hyacinth -- South Africa -- Eastern Cape , Water hyacinth -- Biological control -- South Africa -- Eastern Cape , Insects as biological pest control agents , Miridae -- South Africa -- Eastern Cape , Beetles -- South Africa -- Eastern Cape , Competition (Biology)
- Description: Interactions between insects have been shown to be important regulators of population abundances and dynamics as well as drivers of spatial segregation and distribution. These are important aspects of the ecology of insects used in biological control and may have implications for the overall success of a particular programme. In the history of biological control there has been a tendency to release a suite of agents against a weed, which in some cases has increased the level of success, while in others little change has been observed. In most of these cases the implications of increasing the level of complexity of the system is not taken into account and there is little research on the effect of releasing another agent into the system. A brief meta-analysis was done on all the biological control programmes initiated in South Africa. Emphasis was placed on multi-species releases and the effects that overlapping niches were having on the number of agents responsible for the success of a programme. Where overlapping niches were present among agents released the number of agents responsible for success was lower than the number established. Water hyacinth, Eichhornia crassipes (Martius) Solms-Laubach in South Africa has more arthropod agents released against it than anywhere else in the world, yet control has been variable. If the biology and host utilisation of all the agents against water hyacinth is considered, a definite overlap of niches is apparent in at least one life stage of all the agents. Therefore the probability of these insects interacting is high, especially if they are established at the same site in the field. Three of the insects released in South Africa have been selected to investigate possible interactions. They are Neochetina eichhorniae Warner, Neochetina bruchi Hustache and Eccritotarsus catarinensis (Carvalho). Y-tube olfactometer bioassays were used to measure responses of these insects to water hyacinth with prior feeding damage by either conspecifics or heterospecifics. This was done to determine whether olfactory cues played a role in host acceptability and avoidance of conspecifics or heterospecifics. The insects were given a choice between damaged and undamaged plants in various combinations. There was a significant preference for the undamaged plants when given a choice between undamaged and damaged plants. However when the insects were given a choice between two damaged plants there was no discrimination between heterospecific or conspecific damaged plants. This may indicate that there is little or no ecological cost for the insect to share a plant with other insects utilising a similar resource. Insect – insect interactions were investigated in a common garden plot experiment to measure the impact that pairwise combinations of the insect may have on their performance. There was a significant interaction between the mirid E. catarinensis and the weevil N. eichhorniae, with the weevil not performing as well when in combination with the mirid than when alone. Interestingly there was a negative interaction between the two weevil species when in combination, however it was impossible to determine which species was being affected if not both. None of the insects performed significantly better when in combination with another insect. A field study on Wriggleswade Dam in the Eastern Cape, South Africa was initiated to determine whether the relationship between the mirid E. catarinensis and the weevil N. eichhorniae could be determined in the field. The performance of the insects at the different sites in the field suggests that there was an interaction between the agents. This interaction did not limit the establishment of either insect at a site, but it did result in one insect dominating at a site over another. Interactions between the three species of insect tested in this thesis suggest that there are both negative and neutral relationships between them. A basic comparison between the insect performances from 15 sites around the country was done to determine if the spatial segregation observed in the field could be extrapolated to the natural South African situation. The interaction observed between N. eichhorniae and E. catarinensis does seem to extrapolate to the general South African situation where there is definite spatial segregation on a landscape level. The co–occurrence of the two Neochetina weevils at these sites suggests that the negative relationship observed between them in the common garden experiment does not extrapolate to the field. The results from this thesis suggest that the interactions between the agents tested would not limit establishment or have significant ramifications on performance. However, there may be spatial and temporal segregation of these species in the introduced range.
- Full Text:
- Date Issued: 2012
Assessing linkages between local ecological knowledge, HIV/AIDS and the commercialisation of natural resources across Southern Africa
- Authors: Weyer, Dylan James
- Date: 2012
- Subjects: AIDS (Disease) -- Africa, Southern , HIV infections -- Africa, Southern , Natural resources -- Management -- Africa, Southern , Traditional ecological knowledge -- Africa, Southern , Households -- Economic aspects -- Africa, Southern , Poverty -- Environmental aspects -- Africa, Southern , Ecology -- Economic aspects -- Africa, Southern
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4769 , http://hdl.handle.net/10962/d1007180 , AIDS (Disease) -- Africa, Southern , HIV infections -- Africa, Southern , Natural resources -- Management -- Africa, Southern , Traditional ecological knowledge -- Africa, Southern , Households -- Economic aspects -- Africa, Southern , Poverty -- Environmental aspects -- Africa, Southern , Ecology -- Economic aspects -- Africa, Southern
- Description: That natural resources (NRs) are important to those experiencing adversity, and, especially, vulnerability associated with HIV/AIDS, is well documented, particularly with respect to food and energy security. What is unclear is where HIV/AIDS ranks in terms of its significance in comparison to other household shocks, the role local ecological knowledge may (LEK) play in households' response to shock, a propos the types of coping strategies that are employed. Consequently, this research aims to bridge the knowledge gap between HIV/AIDS and the degree to which it is contributing to the expansion of NR commercialisation and to explore the unknowns surrounding the influence of LEK on people's choice of coping strategy. A two phase study was designed to provide quantitative rigour with qualitative depth. Phase one was an extensive, rapid survey of NR traders within urban and rural settings in five southern Africa countries. The principle objective was to profile the trade, the livelihoods of those involved and their reasons for entering the trade, to ultimately establish to what degree HIV/AIDS may have been a catalyst for this. Almost one third of the sample entered the trade in response to illness and/or death in their households, with 80% of deaths being of breadwinners. The findings illustrated considerable dependence on the sale of NRs; for almost 60% of the sample it was their household's only source of income. There was evidently increased blurring of the lines between rural and urban NR use with a greater diversity of products being traded in urban areas. Phase two involved in-depth interviews and work with a smaller sample at two sites selected based on the findings from the first phase. It incorporated three groups of households; non-trading, inexperienced trading and experienced trading households. Key areas of focus were household shocks, coping strategies employed in response to these and the role LEK may be playing in the choice of coping strategies. Within a two year period, 95% of households registered at least one shock, of which 80% recorded AIDS-related proxy shocks. Non-trading households were significantly worse-off in this regard, while in the case of non-AIDS proxy shocks, there was no such difference between groups. The most frequently employed coping strategy was the consumption and sale of NRs and was of particular importance when households were faced with AIDS proxy shocks. Trading households emerged as having superior levels of LEK in comparison to non-trading households, even for non-traded NRs, suggesting that prior LEK of NRs opened up opportunities to trade in NR as a coping strategy. Further inspection of the latter group however revealed that the portion of non-trading households who traded on a very ad hoc basis actually had comparable levels of LEK to the trading households. Despite the ad hoc trading households' vulnerable state and their disproportionately high level of AIDS proxy measures, they had at their disposal, sufficient LEK to unlock certain key coping strategies, namely the NR trade. In this sense there are apparent linkages between LEK, HIV/AIDS and the expansion of the commercialisation of NRs.
- Full Text:
- Date Issued: 2012
- Authors: Weyer, Dylan James
- Date: 2012
- Subjects: AIDS (Disease) -- Africa, Southern , HIV infections -- Africa, Southern , Natural resources -- Management -- Africa, Southern , Traditional ecological knowledge -- Africa, Southern , Households -- Economic aspects -- Africa, Southern , Poverty -- Environmental aspects -- Africa, Southern , Ecology -- Economic aspects -- Africa, Southern
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4769 , http://hdl.handle.net/10962/d1007180 , AIDS (Disease) -- Africa, Southern , HIV infections -- Africa, Southern , Natural resources -- Management -- Africa, Southern , Traditional ecological knowledge -- Africa, Southern , Households -- Economic aspects -- Africa, Southern , Poverty -- Environmental aspects -- Africa, Southern , Ecology -- Economic aspects -- Africa, Southern
- Description: That natural resources (NRs) are important to those experiencing adversity, and, especially, vulnerability associated with HIV/AIDS, is well documented, particularly with respect to food and energy security. What is unclear is where HIV/AIDS ranks in terms of its significance in comparison to other household shocks, the role local ecological knowledge may (LEK) play in households' response to shock, a propos the types of coping strategies that are employed. Consequently, this research aims to bridge the knowledge gap between HIV/AIDS and the degree to which it is contributing to the expansion of NR commercialisation and to explore the unknowns surrounding the influence of LEK on people's choice of coping strategy. A two phase study was designed to provide quantitative rigour with qualitative depth. Phase one was an extensive, rapid survey of NR traders within urban and rural settings in five southern Africa countries. The principle objective was to profile the trade, the livelihoods of those involved and their reasons for entering the trade, to ultimately establish to what degree HIV/AIDS may have been a catalyst for this. Almost one third of the sample entered the trade in response to illness and/or death in their households, with 80% of deaths being of breadwinners. The findings illustrated considerable dependence on the sale of NRs; for almost 60% of the sample it was their household's only source of income. There was evidently increased blurring of the lines between rural and urban NR use with a greater diversity of products being traded in urban areas. Phase two involved in-depth interviews and work with a smaller sample at two sites selected based on the findings from the first phase. It incorporated three groups of households; non-trading, inexperienced trading and experienced trading households. Key areas of focus were household shocks, coping strategies employed in response to these and the role LEK may be playing in the choice of coping strategies. Within a two year period, 95% of households registered at least one shock, of which 80% recorded AIDS-related proxy shocks. Non-trading households were significantly worse-off in this regard, while in the case of non-AIDS proxy shocks, there was no such difference between groups. The most frequently employed coping strategy was the consumption and sale of NRs and was of particular importance when households were faced with AIDS proxy shocks. Trading households emerged as having superior levels of LEK in comparison to non-trading households, even for non-traded NRs, suggesting that prior LEK of NRs opened up opportunities to trade in NR as a coping strategy. Further inspection of the latter group however revealed that the portion of non-trading households who traded on a very ad hoc basis actually had comparable levels of LEK to the trading households. Despite the ad hoc trading households' vulnerable state and their disproportionately high level of AIDS proxy measures, they had at their disposal, sufficient LEK to unlock certain key coping strategies, namely the NR trade. In this sense there are apparent linkages between LEK, HIV/AIDS and the expansion of the commercialisation of NRs.
- Full Text:
- Date Issued: 2012
Anthropogenic threats to resident and dispersing African wild dogs west and south of the Kruger National Park, South Africa
- Watermeyer, Jessica Patricia
- Authors: Watermeyer, Jessica Patricia
- Date: 2012
- Subjects: African wild dog -- South Africa -- Kruger National Park , African wild dog -- Effect of human beings on -- South Africa -- Kruger National Park , African wild dog -- Behavior -- South Africa -- Kruger National Park , Endangered species -- South Africa -- Kruger National Park , African wild dog -- Dispersal -- South Africa -- Kruger National Park , African wild dog -- Conservation -- South Africa -- Kruger National Park , Animal populations -- Estimates -- South Africa -- Kruger National Park
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5636 , http://hdl.handle.net/10962/d1005318 , African wild dog -- South Africa -- Kruger National Park , African wild dog -- Effect of human beings on -- South Africa -- Kruger National Park , African wild dog -- Behavior -- South Africa -- Kruger National Park , Endangered species -- South Africa -- Kruger National Park , African wild dog -- Dispersal -- South Africa -- Kruger National Park , African wild dog -- Conservation -- South Africa -- Kruger National Park , Animal populations -- Estimates -- South Africa -- Kruger National Park
- Description: African wild dog Lycaon pictus populations are declining and the species is listed as Endangered by the IUCN. The Kruger National Park (KNP) is home to the only viable population of wild dogs in South Africa, but census results reveal consistently low numbers since the late 1990s. Wild dogs display wide-ranging behaviour and it is possible that the species might frequently use unprotected lands adjacent to the KNP. However, very little is known about wild dog movements beyond the boundaries of the KNP, and whether or not adjacent land owners are tolerant of the species. Significantly, threats along the boundaries may have negative consequences for the KNP population. This research investigated the dispersal habits of wild dogs beyond the western and southern boundaries of the KNP, and gathered information on human tolerance, and anthropogenic threats in an area of mixed land use. The land west of the KNP presented the best prospect for wild dog range expansion. The wild dog packs operating outside the KNP had smaller home ranges and less home range overlap than the packs operating within the KNP. In addition, my data suggested that the development of conservancies and the formation of ecotourism-based land use practices would be beneficial for wild dog conservation. Failed wild dog dispersals due to snaring and human persecution could threaten the genetic stability and persistence of the KNP population. Therefore, raising awareness and an understanding of the plight of wild dogs is important for improving land owner perception and tolerance outside of protected areas. The rapidly increasing human population continues to infringe on protected lands and fragment landscapes, thus cooperation from individual land owners is vital for the conservation of free-ranging large carnivores.
- Full Text:
- Date Issued: 2012
- Authors: Watermeyer, Jessica Patricia
- Date: 2012
- Subjects: African wild dog -- South Africa -- Kruger National Park , African wild dog -- Effect of human beings on -- South Africa -- Kruger National Park , African wild dog -- Behavior -- South Africa -- Kruger National Park , Endangered species -- South Africa -- Kruger National Park , African wild dog -- Dispersal -- South Africa -- Kruger National Park , African wild dog -- Conservation -- South Africa -- Kruger National Park , Animal populations -- Estimates -- South Africa -- Kruger National Park
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5636 , http://hdl.handle.net/10962/d1005318 , African wild dog -- South Africa -- Kruger National Park , African wild dog -- Effect of human beings on -- South Africa -- Kruger National Park , African wild dog -- Behavior -- South Africa -- Kruger National Park , Endangered species -- South Africa -- Kruger National Park , African wild dog -- Dispersal -- South Africa -- Kruger National Park , African wild dog -- Conservation -- South Africa -- Kruger National Park , Animal populations -- Estimates -- South Africa -- Kruger National Park
- Description: African wild dog Lycaon pictus populations are declining and the species is listed as Endangered by the IUCN. The Kruger National Park (KNP) is home to the only viable population of wild dogs in South Africa, but census results reveal consistently low numbers since the late 1990s. Wild dogs display wide-ranging behaviour and it is possible that the species might frequently use unprotected lands adjacent to the KNP. However, very little is known about wild dog movements beyond the boundaries of the KNP, and whether or not adjacent land owners are tolerant of the species. Significantly, threats along the boundaries may have negative consequences for the KNP population. This research investigated the dispersal habits of wild dogs beyond the western and southern boundaries of the KNP, and gathered information on human tolerance, and anthropogenic threats in an area of mixed land use. The land west of the KNP presented the best prospect for wild dog range expansion. The wild dog packs operating outside the KNP had smaller home ranges and less home range overlap than the packs operating within the KNP. In addition, my data suggested that the development of conservancies and the formation of ecotourism-based land use practices would be beneficial for wild dog conservation. Failed wild dog dispersals due to snaring and human persecution could threaten the genetic stability and persistence of the KNP population. Therefore, raising awareness and an understanding of the plight of wild dogs is important for improving land owner perception and tolerance outside of protected areas. The rapidly increasing human population continues to infringe on protected lands and fragment landscapes, thus cooperation from individual land owners is vital for the conservation of free-ranging large carnivores.
- Full Text:
- Date Issued: 2012
Submission to Press Freedom Commission (PFC) on Media Self-regulation, Co-regulation or Statutory regulation in South Africa:
- Wasserman, Herman, Steenveld, Lynette N, Strelitz, Larry N, Amner, Roderick J, Boshoff, Priscilla A, Mathurine, Jude, Garman, Anthea
- Authors: Wasserman, Herman , Steenveld, Lynette N , Strelitz, Larry N , Amner, Roderick J , Boshoff, Priscilla A , Mathurine, Jude , Garman, Anthea
- Date: 2012
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/143571 , vital:38263 , ISBN , https://www.ru.ac.za/media/rhodesuniversity/content/ruhome/documents/JMS Submission to Press Freedom Commission.pdf
- Description: Prof Duncan has outlined the relative merits and demerits of self-regulation, co-regulation and deregulation, with which we are in broad agreement. She has also ably dealt with the three functions of regulatory bodies, namely the setting of ground rules for the industry to ensure best practice; enforcement of these; and adjudication of claims and counter claims re journalistic practice (Duncan 2012, p17). Finally, she has also taken up the issue of the necessity of accepting Third Party Complaints as one of the fundamental mechanisms by which citizens can make complaints on the basis of principle, rather than being personally aggrieved. While we are in broad agreement with her on these issues, we would like to highlight some further points for consideration.
- Full Text:
- Date Issued: 2012
- Authors: Wasserman, Herman , Steenveld, Lynette N , Strelitz, Larry N , Amner, Roderick J , Boshoff, Priscilla A , Mathurine, Jude , Garman, Anthea
- Date: 2012
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/143571 , vital:38263 , ISBN , https://www.ru.ac.za/media/rhodesuniversity/content/ruhome/documents/JMS Submission to Press Freedom Commission.pdf
- Description: Prof Duncan has outlined the relative merits and demerits of self-regulation, co-regulation and deregulation, with which we are in broad agreement. She has also ably dealt with the three functions of regulatory bodies, namely the setting of ground rules for the industry to ensure best practice; enforcement of these; and adjudication of claims and counter claims re journalistic practice (Duncan 2012, p17). Finally, she has also taken up the issue of the necessity of accepting Third Party Complaints as one of the fundamental mechanisms by which citizens can make complaints on the basis of principle, rather than being personally aggrieved. While we are in broad agreement with her on these issues, we would like to highlight some further points for consideration.
- Full Text:
- Date Issued: 2012
On the underwater visual census of Western Indian Ocean coral reef fishes
- Authors: Wartenberg, Reece
- Date: 2012
- Subjects: Coral reef fishes -- Africa, Southern , Coral reef fishes -- Indian Ocean , Coral reef fishes -- Behavior , Fish communities -- Africa, Southern , Fish communities -- Indian Ocean , Groundfishes -- Africa, Southern , Groundfishes -- Indian Ocean , Groundfishes -- Behavior
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5308 , http://hdl.handle.net/10962/d1005153 , Coral reef fishes -- Africa, Southern , Coral reef fishes -- Indian Ocean , Coral reef fishes -- Behavior , Fish communities -- Africa, Southern , Fish communities -- Indian Ocean , Groundfishes -- Africa, Southern , Groundfishes -- Indian Ocean , Groundfishes -- Behavior
- Description: This study conducted the first high-resolution investigation of the ichthyofaunal assemblages on a high-latitude coral reef in the Western Indian Ocean (WIO). Two-Mile reef, in South Africa, is a large, accessible patch-reef, and was selected as a candidate study area. Although the effect of season in structuring coral reef fish communities is most-often overlooked, the relationship between these fish communities and their habitat structure has been investigated. In South Africa, however, neither of these potential community-level drivers has been explored. As coral reefs worldwide are faced with high levels of usage pressure, nondestructive underwater visual census (UVC) techniques were identified as the most appropriate survey methods. This study had two primary aims that were; (1) to identify the most suitable technique for the UVC of coral reef fishes, and to test variations of the selected technique for appropriateness to implementation in long-term monitoring programs, and (2) to determine if possible changes to ichthyofaunal community structure could be related to trends in season and/or habitat characteristics. A review of the literature indicated that the most appropriate UVC method for surveying epibenthic coral reef fishes is underwater transecting. To compare the traditional slate-based transects to variations that implement digital image technology, slate transects were compared to a first-attempt digital photographic transect technique, and digital videographic transects. Videographic transects produced the most favourable species richness, abundance, and standard deviations of the three techniques. Diversity was not significantly different between transect techniques. The minimum required sample size was lowest for videographic transects (17 replicates), intermediate for photographic transects (27 replicates) and highest for slate transects (37 replicates). Videographic and photographic transects required greater analysis time to generate counts, but required lower observer training time. While videographic transects produced the lowest proportion of species considered unidentifiable, all three transect techniques showed similar functionality to surveying epibenthic coral reef fishes. Videographic transects were therefore identified as the most appropriate UVC technique for this study. Videographic transects at shallow (6 – 14 m), intermediate (14 – 22 m) and deep (22 – 30 m) depths in mid-winter and mid-summer, sampled a total of 41 families consisting of 209 species and 18172 individuals, dominated by pomacentrids in abundance and labrids in richness. The fish assemblages on Two-Mile Reef were found to be similar in composition to lower-latitude WIO reefs. Overall ichthyofaunal abundance and richness was significantly higher in summer than in winter, and was higher at shallow sites than at intermediate and deep sites. A multivariate approach confirmed differences between seasons at shallow depths but not between seasons at intermediate and deep depths. The fish assemblages on Two-Mile Reef can therefore be described as being comprised of four relatively distinct communities: a shallow, winter community; a shallow, summer community; a year-round intermediate community; and a year-round deep community. The distributions of discriminating species indicated that high abundances of the algal-feeding pomacentrids are observed only at shallow and intermediate sites while high abundances of the zooplanktivorous serranid subfamily, the Anthiinae, are observed predominantly at deep sites. Assessment of all measured supplementary variables indicated that of all factor combinations, observed patterns could be ascribed most strongly to depth. Quantification of reef characteristics indicated that as depth increases, habitat complexity decreases, benthic communities shift from dense coral domination to sparse sponge domination, and algal biomass and cover decreases. The ability of the videographic transect technique to detect changes in community structure with season and depth indicates that season and depth should be accounted for in future high-latitude ichtyofaunal surveys, and that the videographic transect technique is suitable for implementation in long-term monitoring programs on coral reefs. The similarity in fish assemblages between Two-Mile Reef and lower latitude regions suggests that the protocol for surveying epibenthic coral reef fishes, resulting from this study, is relevant throughout the continental WIO.
- Full Text:
- Date Issued: 2012
- Authors: Wartenberg, Reece
- Date: 2012
- Subjects: Coral reef fishes -- Africa, Southern , Coral reef fishes -- Indian Ocean , Coral reef fishes -- Behavior , Fish communities -- Africa, Southern , Fish communities -- Indian Ocean , Groundfishes -- Africa, Southern , Groundfishes -- Indian Ocean , Groundfishes -- Behavior
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5308 , http://hdl.handle.net/10962/d1005153 , Coral reef fishes -- Africa, Southern , Coral reef fishes -- Indian Ocean , Coral reef fishes -- Behavior , Fish communities -- Africa, Southern , Fish communities -- Indian Ocean , Groundfishes -- Africa, Southern , Groundfishes -- Indian Ocean , Groundfishes -- Behavior
- Description: This study conducted the first high-resolution investigation of the ichthyofaunal assemblages on a high-latitude coral reef in the Western Indian Ocean (WIO). Two-Mile reef, in South Africa, is a large, accessible patch-reef, and was selected as a candidate study area. Although the effect of season in structuring coral reef fish communities is most-often overlooked, the relationship between these fish communities and their habitat structure has been investigated. In South Africa, however, neither of these potential community-level drivers has been explored. As coral reefs worldwide are faced with high levels of usage pressure, nondestructive underwater visual census (UVC) techniques were identified as the most appropriate survey methods. This study had two primary aims that were; (1) to identify the most suitable technique for the UVC of coral reef fishes, and to test variations of the selected technique for appropriateness to implementation in long-term monitoring programs, and (2) to determine if possible changes to ichthyofaunal community structure could be related to trends in season and/or habitat characteristics. A review of the literature indicated that the most appropriate UVC method for surveying epibenthic coral reef fishes is underwater transecting. To compare the traditional slate-based transects to variations that implement digital image technology, slate transects were compared to a first-attempt digital photographic transect technique, and digital videographic transects. Videographic transects produced the most favourable species richness, abundance, and standard deviations of the three techniques. Diversity was not significantly different between transect techniques. The minimum required sample size was lowest for videographic transects (17 replicates), intermediate for photographic transects (27 replicates) and highest for slate transects (37 replicates). Videographic and photographic transects required greater analysis time to generate counts, but required lower observer training time. While videographic transects produced the lowest proportion of species considered unidentifiable, all three transect techniques showed similar functionality to surveying epibenthic coral reef fishes. Videographic transects were therefore identified as the most appropriate UVC technique for this study. Videographic transects at shallow (6 – 14 m), intermediate (14 – 22 m) and deep (22 – 30 m) depths in mid-winter and mid-summer, sampled a total of 41 families consisting of 209 species and 18172 individuals, dominated by pomacentrids in abundance and labrids in richness. The fish assemblages on Two-Mile Reef were found to be similar in composition to lower-latitude WIO reefs. Overall ichthyofaunal abundance and richness was significantly higher in summer than in winter, and was higher at shallow sites than at intermediate and deep sites. A multivariate approach confirmed differences between seasons at shallow depths but not between seasons at intermediate and deep depths. The fish assemblages on Two-Mile Reef can therefore be described as being comprised of four relatively distinct communities: a shallow, winter community; a shallow, summer community; a year-round intermediate community; and a year-round deep community. The distributions of discriminating species indicated that high abundances of the algal-feeding pomacentrids are observed only at shallow and intermediate sites while high abundances of the zooplanktivorous serranid subfamily, the Anthiinae, are observed predominantly at deep sites. Assessment of all measured supplementary variables indicated that of all factor combinations, observed patterns could be ascribed most strongly to depth. Quantification of reef characteristics indicated that as depth increases, habitat complexity decreases, benthic communities shift from dense coral domination to sparse sponge domination, and algal biomass and cover decreases. The ability of the videographic transect technique to detect changes in community structure with season and depth indicates that season and depth should be accounted for in future high-latitude ichtyofaunal surveys, and that the videographic transect technique is suitable for implementation in long-term monitoring programs on coral reefs. The similarity in fish assemblages between Two-Mile Reef and lower latitude regions suggests that the protocol for surveying epibenthic coral reef fishes, resulting from this study, is relevant throughout the continental WIO.
- Full Text:
- Date Issued: 2012
An investigation into the antidiabetic and catalytic properties of oxovanadium(IV) complexes
- Authors: Walmsley, Ryan Steven
- Date: 2012
- Subjects: Hypoglycemic agents Ligands (Biochemistry) Complex compounds Potentiometry Proton transfer reactions Stability Imidazoles Vanadium catalysts
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4320 , http://hdl.handle.net/10962/d1004978
- Description: In part 1 of this thesis, the antidiabetic activity of a series of novel oxovanadium(IV) complexes was investigated. A range of bidentate N,O-donor ligands, which partially mimic naturally occurring bioligands, were prepared and reacted with the vanadyl ion to form the corresponding bis-coordinated complexes. Initially, 2-(2ˊ-hydroxyphenyl)-1R-imidazoline (where R = H, ethyl and ethanol) ligands were prepared. The aqueous pH-metric chemical speciation was investigated using glass electrode potentiometry which allowed for the determination of protonation and stability constants of the ligands and complexes, respectively. The species distribution diagrams generated from this information gave an indication of how the complexes might behave across the broad pH range experienced in the digestive and circulatory systems. This information was used to create an improved 2nd generation of ligands that were constructed by combining the imidazole and carboxylic acid functionalities. These corresponding bis[(imidazolyl)carboxylato]-oxovanadium(IV) complexes displayed a broader pH-metric stability. Both sets of complexes improved glucose uptake and reduced coagulation in vitro. In part 2 of this thesis, a range of homogeneous and heterogeneous oxovanadium(IV) catalysts were prepared. Firstly, Merrifield beads were functionalized with ligands from Part 1 and then reacted with vanadyl sulfate to afford the corresponding heterogeneous catalysts. These displayed promising catalytic activity for the peroxide facilitated oxidation of thioanisole, styrene and ethylbenzene as well as the oxidative bromination of phenol red. Smaller imidazole-containing beads with higher surface areas than the Merrifield beads were prepared by suspension polymerization. These beads similarly demonstrated excellent catalytic activity for the oxidation of thioanisole and were highly recyclable. In attempt to increase the exposed catalytic surface area, while retaining the ease of separation achieved in the before mentioned systems, micron to nano sized electrospun fibers containing coordinating ligands were fabricated. The corresponding oxovanadium(IV) functionalized fibers were applied to the oxidation of thioanisole using a continuous flow system. The flexible and porous nature of the fiber mats was well suited to this approach. After optimization of the reactant flow rate and catalyst amount, near quantitative (> 99%) oxidation was achieved for an extended period. In addition, leaching of vanadium was mitigated by modification of the attached ligand or polymer material.
- Full Text:
- Date Issued: 2012
- Authors: Walmsley, Ryan Steven
- Date: 2012
- Subjects: Hypoglycemic agents Ligands (Biochemistry) Complex compounds Potentiometry Proton transfer reactions Stability Imidazoles Vanadium catalysts
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4320 , http://hdl.handle.net/10962/d1004978
- Description: In part 1 of this thesis, the antidiabetic activity of a series of novel oxovanadium(IV) complexes was investigated. A range of bidentate N,O-donor ligands, which partially mimic naturally occurring bioligands, were prepared and reacted with the vanadyl ion to form the corresponding bis-coordinated complexes. Initially, 2-(2ˊ-hydroxyphenyl)-1R-imidazoline (where R = H, ethyl and ethanol) ligands were prepared. The aqueous pH-metric chemical speciation was investigated using glass electrode potentiometry which allowed for the determination of protonation and stability constants of the ligands and complexes, respectively. The species distribution diagrams generated from this information gave an indication of how the complexes might behave across the broad pH range experienced in the digestive and circulatory systems. This information was used to create an improved 2nd generation of ligands that were constructed by combining the imidazole and carboxylic acid functionalities. These corresponding bis[(imidazolyl)carboxylato]-oxovanadium(IV) complexes displayed a broader pH-metric stability. Both sets of complexes improved glucose uptake and reduced coagulation in vitro. In part 2 of this thesis, a range of homogeneous and heterogeneous oxovanadium(IV) catalysts were prepared. Firstly, Merrifield beads were functionalized with ligands from Part 1 and then reacted with vanadyl sulfate to afford the corresponding heterogeneous catalysts. These displayed promising catalytic activity for the peroxide facilitated oxidation of thioanisole, styrene and ethylbenzene as well as the oxidative bromination of phenol red. Smaller imidazole-containing beads with higher surface areas than the Merrifield beads were prepared by suspension polymerization. These beads similarly demonstrated excellent catalytic activity for the oxidation of thioanisole and were highly recyclable. In attempt to increase the exposed catalytic surface area, while retaining the ease of separation achieved in the before mentioned systems, micron to nano sized electrospun fibers containing coordinating ligands were fabricated. The corresponding oxovanadium(IV) functionalized fibers were applied to the oxidation of thioanisole using a continuous flow system. The flexible and porous nature of the fiber mats was well suited to this approach. After optimization of the reactant flow rate and catalyst amount, near quantitative (> 99%) oxidation was achieved for an extended period. In addition, leaching of vanadium was mitigated by modification of the attached ligand or polymer material.
- Full Text:
- Date Issued: 2012
Investigating the impact of brand reputation on brand architecture strategies : a study on a South African automotive company
- Authors: Waddington, Andrew John
- Date: 2012
- Subjects: Branding (Marketing) -- Case studies Automobile industry and trade -- South Africa -- Case studies Toyota Jidōsha Kōgyō Kabushiki Kaisha -- Case studies Automobiles -- Marketing -- Case studies Product management -- Case studies Branding (Marketing) -- Management -- Case studies Corporate image -- Management -- Case studies Brand name products -- South Africa -- Case studies
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1179 , http://hdl.handle.net/10962/d1002796
- Description: The brand architecture of an organisation has become increasingly important to global management and marketing professionals, as it deals with structures and designs of brands which are constantly influenced by a changing environment. The market realities and changes brands face continuously impact the reputation of the brand, which is critical to sustain competitive advantage. The primary purpose of the study was to investigate the impact brand reputation has on brand architecture strategies, and an automotive company was chosen as the focus of the research. This research aims to help managers, marketers and brand owners make informative decisions regarding the brand architecture of a company. A quantitative content analysis methodology was used along with a webpage keyword counting application (WebWords). The application was used based on the principles outlined by Corporate Brand and Reputation Analysis (COBRA), which uses a four step progressive filtering process in filtering traditional and consumer generated media. The results from WebWords were then aligned to the brand architecture strategies from the brand relationship spectrum (BRS) to gain insight as to which of the strategies from the BRS were most vulnerable to reputational damage. The study found that the branded house and sub-brand strategies were most vulnerable to reputational damage based on the number reputational hits received. The connection between the master brand and the sub-brands could cause both brands to be affected should any reputational issues arise.
- Full Text:
- Date Issued: 2012
- Authors: Waddington, Andrew John
- Date: 2012
- Subjects: Branding (Marketing) -- Case studies Automobile industry and trade -- South Africa -- Case studies Toyota Jidōsha Kōgyō Kabushiki Kaisha -- Case studies Automobiles -- Marketing -- Case studies Product management -- Case studies Branding (Marketing) -- Management -- Case studies Corporate image -- Management -- Case studies Brand name products -- South Africa -- Case studies
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1179 , http://hdl.handle.net/10962/d1002796
- Description: The brand architecture of an organisation has become increasingly important to global management and marketing professionals, as it deals with structures and designs of brands which are constantly influenced by a changing environment. The market realities and changes brands face continuously impact the reputation of the brand, which is critical to sustain competitive advantage. The primary purpose of the study was to investigate the impact brand reputation has on brand architecture strategies, and an automotive company was chosen as the focus of the research. This research aims to help managers, marketers and brand owners make informative decisions regarding the brand architecture of a company. A quantitative content analysis methodology was used along with a webpage keyword counting application (WebWords). The application was used based on the principles outlined by Corporate Brand and Reputation Analysis (COBRA), which uses a four step progressive filtering process in filtering traditional and consumer generated media. The results from WebWords were then aligned to the brand architecture strategies from the brand relationship spectrum (BRS) to gain insight as to which of the strategies from the BRS were most vulnerable to reputational damage. The study found that the branded house and sub-brand strategies were most vulnerable to reputational damage based on the number reputational hits received. The connection between the master brand and the sub-brands could cause both brands to be affected should any reputational issues arise.
- Full Text:
- Date Issued: 2012
An evaluation of a motor retail organisation's lead management system
- Authors: Waddell, Alda
- Date: 2012
- Subjects: Barloworld Motor Retail Automobile industry and trade -- South Africa Product management -- South Africa Automobiles -- Marketing -- South Africa Internet marketing -- South Africa Consumer behavior -- South Africa Customer services -- South Africa Automobile dealers -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:779 , http://hdl.handle.net/10962/d1003900
- Description: This research was motivated by the lack of systems and methodologies in the automotive retail business sector to adequately monitor and analyse prospective customers' behaviours as a basis for developing sales. The objective of this research was to determine if lead scoring would indeed represent a good investment of time and resources for Barloworld Motor Retail. The real value for Barloworld Motor Retail is in the proven methodology for properly managing leads and the sales process. Lead scoring should have sales teams more focused because of the qualified opportunities. The sales cycle can also be efficiently managed from introduction to closure. What is Lead Scoring? In short, lead scoring identifies or measures the value of a lead to determine to which extent a lead could result in a sale. The aim of the lead scoring process is to gather as much information as possible from the prospective customer. Once information has been acquired, it is important to hand over the hot leads to sales while the warm and cold leads remain with marketing to be nurtured. A lead is a potential customer who wants to learn more about what a company has to offer, and who has acknowledged having a requirement or need that a company could help satisfy. Where this position is coupled with elements of the ideal or desired customer profile, a meaningful lead definition emerges. When a salesperson receives a lead as depicted in Figure 1, the decision must be made as to whether to promote the lead into an opportunity or recycle it back to marketing. The crucial determination would be whether the prospect is ready to enter a buying cycle, or not. Figure 1 also illustrates the lead scoring "evaluation" process. The researcher used the Barloworld Automotive www.mywheels.co.za Webpage to obtain information for this research project. The results obtained from this measurement were compared with the results obtained from other marketing initiatives and practices in the automotive industry to describe the value of lead scoring. This research is undertaken under two main headings, namely marketing and evaluating a lead management system by introducing lead scoring. In reference to marketing, Albee (2010) says that lead scoring is based on marketing that can automate the ability to know exactly when the leads in the nurturing program are sales ready and then transition them to the sales force without delay. Chekitan and Schultz (2005), introduced the notion of SIVA which stands for Solution, Information, Value, and Access. This is basically the four p's of the marketing mix, namely product, promotion, price and placement Kotler (2000) renamed and reworded to provide a customer focus. Marketing managers use this model to generate the best possible response from the target market by blending four or more combinations in the best way. The elements of the marketing mix are all controllable variables. The marketing mix can be adjusted on a frequent basis to meet the changing needs of the target market and the other dynamics of the marketing environment. The study of internet consumer behaviour is a fundamental part of the gathering of information related to lead scoring. To an extent it is also relevant to the formulation of a leads nurturing model that will positively influence buyer perceptions and help to trigger the purchase decision. With regard to the purchasing of motor vehicles, consumers will seldom make a purchase decision without personal exposure by way of sensory explanation (look, feel and touch). Internet marketing connects the physically remote consumer with the product benefits through a process of abstract positioning, and focuses on obtaining "hits" from consumers who are competent and enabled to make a positive purchase decision. Internet marketing refers to the strategies that companies use to market their products or services online. The marketing concept remains the guiding concept for companies wishing to design and implement an effective leads scoring system. Lead scoring is the process that involves the following activities: • Lead identification; • Lead collection and consolidation; • Predictive analysis of lead scoring; • Lead nurturing; • Lead distribution.
- Full Text:
- Date Issued: 2012
- Authors: Waddell, Alda
- Date: 2012
- Subjects: Barloworld Motor Retail Automobile industry and trade -- South Africa Product management -- South Africa Automobiles -- Marketing -- South Africa Internet marketing -- South Africa Consumer behavior -- South Africa Customer services -- South Africa Automobile dealers -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:779 , http://hdl.handle.net/10962/d1003900
- Description: This research was motivated by the lack of systems and methodologies in the automotive retail business sector to adequately monitor and analyse prospective customers' behaviours as a basis for developing sales. The objective of this research was to determine if lead scoring would indeed represent a good investment of time and resources for Barloworld Motor Retail. The real value for Barloworld Motor Retail is in the proven methodology for properly managing leads and the sales process. Lead scoring should have sales teams more focused because of the qualified opportunities. The sales cycle can also be efficiently managed from introduction to closure. What is Lead Scoring? In short, lead scoring identifies or measures the value of a lead to determine to which extent a lead could result in a sale. The aim of the lead scoring process is to gather as much information as possible from the prospective customer. Once information has been acquired, it is important to hand over the hot leads to sales while the warm and cold leads remain with marketing to be nurtured. A lead is a potential customer who wants to learn more about what a company has to offer, and who has acknowledged having a requirement or need that a company could help satisfy. Where this position is coupled with elements of the ideal or desired customer profile, a meaningful lead definition emerges. When a salesperson receives a lead as depicted in Figure 1, the decision must be made as to whether to promote the lead into an opportunity or recycle it back to marketing. The crucial determination would be whether the prospect is ready to enter a buying cycle, or not. Figure 1 also illustrates the lead scoring "evaluation" process. The researcher used the Barloworld Automotive www.mywheels.co.za Webpage to obtain information for this research project. The results obtained from this measurement were compared with the results obtained from other marketing initiatives and practices in the automotive industry to describe the value of lead scoring. This research is undertaken under two main headings, namely marketing and evaluating a lead management system by introducing lead scoring. In reference to marketing, Albee (2010) says that lead scoring is based on marketing that can automate the ability to know exactly when the leads in the nurturing program are sales ready and then transition them to the sales force without delay. Chekitan and Schultz (2005), introduced the notion of SIVA which stands for Solution, Information, Value, and Access. This is basically the four p's of the marketing mix, namely product, promotion, price and placement Kotler (2000) renamed and reworded to provide a customer focus. Marketing managers use this model to generate the best possible response from the target market by blending four or more combinations in the best way. The elements of the marketing mix are all controllable variables. The marketing mix can be adjusted on a frequent basis to meet the changing needs of the target market and the other dynamics of the marketing environment. The study of internet consumer behaviour is a fundamental part of the gathering of information related to lead scoring. To an extent it is also relevant to the formulation of a leads nurturing model that will positively influence buyer perceptions and help to trigger the purchase decision. With regard to the purchasing of motor vehicles, consumers will seldom make a purchase decision without personal exposure by way of sensory explanation (look, feel and touch). Internet marketing connects the physically remote consumer with the product benefits through a process of abstract positioning, and focuses on obtaining "hits" from consumers who are competent and enabled to make a positive purchase decision. Internet marketing refers to the strategies that companies use to market their products or services online. The marketing concept remains the guiding concept for companies wishing to design and implement an effective leads scoring system. Lead scoring is the process that involves the following activities: • Lead identification; • Lead collection and consolidation; • Predictive analysis of lead scoring; • Lead nurturing; • Lead distribution.
- Full Text:
- Date Issued: 2012
The feeding and spatial ecology of cheetahs (Acinonyx jubatus) and lions (Panthera leo) in the Little Karoo, South Africa
- Authors: Vorster, Paul Hendrik
- Date: 2012
- Subjects: Sanbona Wildlife Reserve , Cheetah -- South Africa -- Little Karoo , Lion -- South Africa -- Little Karoo , Cheetah -- Behavior -- South Africa -- Little Karoo , Lion -- Behavior -- South Africa -- Little Karoo , Cheetah -- Food -- South Africa -- Little Karoo , Lion -- Food -- South Africa -- Little Karoo , Spatial behavior in animals , Predation (Biology) , Game reserves -- Management
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5693 , http://hdl.handle.net/10962/d1005379 , Sanbona Wildlife Reserve , Cheetah -- South Africa -- Little Karoo , Lion -- South Africa -- Little Karoo , Cheetah -- Behavior -- South Africa -- Little Karoo , Lion -- Behavior -- South Africa -- Little Karoo , Cheetah -- Food -- South Africa -- Little Karoo , Lion -- Food -- South Africa -- Little Karoo , Spatial behavior in animals , Predation (Biology) , Game reserves -- Management
- Description: The re-introduction of large carnivores into relatively small conservation areas that fall within the historic distribution range of the species is becoming an increasingly common occurrence. The success of such re-introductions depends very much on the quality of the information that is available to guide management decisions, but in many cases, little information is available. The re-introduction of lions and cheetahs to Sanbona created the opportunity to monitor the behaviour of re-introduced predators to a relatively large system that was characterised by a low ungulate stocking density and little standing water. The broad aims were to study the feeding and spatial ecologies of the lions and cheetahs, to collect standard base-line data, and to examine the effects of the low prey density and limited standing water on habitat selection, range size and diet. The diet (data collected from direct observation and faecal analysis) was similar to that reported in previous studies, and lions and cheetahs preferred greater kudu, black wildebeest and springbok. Lions preferred medium to large prey items, and cheetahs preferred medium to small prey items. The hilly and mountainous terrain of much of the reserve meant that only 50% of the total space was available to the predators. Home ranges of most of the predators were focused around the single large body of standing water. This is likely to have been a response to the water, the vegetation, and the prey that was attracted to these. Habitat selection was also influenced by inter and intra-specific interactions at least for a solitary male lion and female cheetahs. Range sizes were larger than on some other reserves and it is suggested that this was a result of the low prey density. These results form the basis for management recommendations including the importance of continuing to monitor the system and opening up additional parts of the reserve to the predators.
- Full Text:
- Date Issued: 2012
- Authors: Vorster, Paul Hendrik
- Date: 2012
- Subjects: Sanbona Wildlife Reserve , Cheetah -- South Africa -- Little Karoo , Lion -- South Africa -- Little Karoo , Cheetah -- Behavior -- South Africa -- Little Karoo , Lion -- Behavior -- South Africa -- Little Karoo , Cheetah -- Food -- South Africa -- Little Karoo , Lion -- Food -- South Africa -- Little Karoo , Spatial behavior in animals , Predation (Biology) , Game reserves -- Management
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5693 , http://hdl.handle.net/10962/d1005379 , Sanbona Wildlife Reserve , Cheetah -- South Africa -- Little Karoo , Lion -- South Africa -- Little Karoo , Cheetah -- Behavior -- South Africa -- Little Karoo , Lion -- Behavior -- South Africa -- Little Karoo , Cheetah -- Food -- South Africa -- Little Karoo , Lion -- Food -- South Africa -- Little Karoo , Spatial behavior in animals , Predation (Biology) , Game reserves -- Management
- Description: The re-introduction of large carnivores into relatively small conservation areas that fall within the historic distribution range of the species is becoming an increasingly common occurrence. The success of such re-introductions depends very much on the quality of the information that is available to guide management decisions, but in many cases, little information is available. The re-introduction of lions and cheetahs to Sanbona created the opportunity to monitor the behaviour of re-introduced predators to a relatively large system that was characterised by a low ungulate stocking density and little standing water. The broad aims were to study the feeding and spatial ecologies of the lions and cheetahs, to collect standard base-line data, and to examine the effects of the low prey density and limited standing water on habitat selection, range size and diet. The diet (data collected from direct observation and faecal analysis) was similar to that reported in previous studies, and lions and cheetahs preferred greater kudu, black wildebeest and springbok. Lions preferred medium to large prey items, and cheetahs preferred medium to small prey items. The hilly and mountainous terrain of much of the reserve meant that only 50% of the total space was available to the predators. Home ranges of most of the predators were focused around the single large body of standing water. This is likely to have been a response to the water, the vegetation, and the prey that was attracted to these. Habitat selection was also influenced by inter and intra-specific interactions at least for a solitary male lion and female cheetahs. Range sizes were larger than on some other reserves and it is suggested that this was a result of the low prey density. These results form the basis for management recommendations including the importance of continuing to monitor the system and opening up additional parts of the reserve to the predators.
- Full Text:
- Date Issued: 2012
Transgressive Christian iconography in post-apartheid South African art
- Authors: Von Veh, Karen Elaine
- Date: 2012
- Subjects: Art -- South Africa -- 20th century Art -- South Africa -- 21st century Christian art and symbolism Apartheid in art Art and society -- South Africa -- History -- 20th century Art and society -- South Africa -- History -- 21st century Parody in art
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2424 , http://hdl.handle.net/10962/d1002220
- Description: In this study I propose that transgressive interpretations of Christian iconography provide a valuable strategy for contemporary artists to engage with perceived social inequalities in postapartheid South Africa. Working in light of Michel Foucault’s idea of an “ontology of the present”, I investigate the ways in which religious iconography has been implicated in the regulation of society. Parodic reworking of Christian imagery in the selected examples is investigated as a strategy to expose these controls and offer a critique of mechanisms which produce normative ‘truths’. I also consider how such imagery has been received and the factors accounting for that reception. The study is contextualized by a brief, literary based, historical overview of Christian religious imagery to explain the strength of feeling evinced by religious images. This includes a review of the conflation of religion and state control of the masses, an analysis of the sovereign controls and disciplinary powers that they wield, and an explication of their illustration in religious iconography. I also identify reasons why such imagery may have seemed compelling to artists working in a post-apartheid context. By locating recent works in terms of those made elsewhere or South African examples prior to the period that is my focus, the works discussed are explored in terms of broader orientations in post-apartheid South African art. Artworks that respond to specific Christian iconography are discussed, including Adam and Eve, The Virgin Mary, Christ, and various saints and sinners. The selected artists whose works form the focus of this study are Diane Victor, Christine Dixie, Majak Bredell, Tracey Rose, Wim Botha, Conrad Botes, Johannes Phokela and Lawrence Lemaoana. Through transgressive depictions of Christian icons these artists address current inequalities in society. The content of their works analysed here includes (among others): the construction of both female and male identities; sexual roles, social roles, and racial identity; the social expectations of contemporary motherhood; repressive role models; Afrikaner heritage; political and social change and its effects; colonial power; sacrifice; murder, rape, and violence in South Africa; abuses of power by role models and politicians; rugby; heroism; and patricide. Christian iconography is a useful communicative tool because it has permeated many cultures over centuries, and the meanings it carries are thus accessible to large numbers of people. Religious imagery is often held sacred or is regarded with a degree of reverence, thus ensuring an emotive response when iconoclasm or transgression of any sort is identified. This study argues that by parodying sacred imagery these artists are able to disturb complacent viewing and encourage viewers to engage critically with some of its underlying implications.
- Full Text:
- Date Issued: 2012
- Authors: Von Veh, Karen Elaine
- Date: 2012
- Subjects: Art -- South Africa -- 20th century Art -- South Africa -- 21st century Christian art and symbolism Apartheid in art Art and society -- South Africa -- History -- 20th century Art and society -- South Africa -- History -- 21st century Parody in art
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2424 , http://hdl.handle.net/10962/d1002220
- Description: In this study I propose that transgressive interpretations of Christian iconography provide a valuable strategy for contemporary artists to engage with perceived social inequalities in postapartheid South Africa. Working in light of Michel Foucault’s idea of an “ontology of the present”, I investigate the ways in which religious iconography has been implicated in the regulation of society. Parodic reworking of Christian imagery in the selected examples is investigated as a strategy to expose these controls and offer a critique of mechanisms which produce normative ‘truths’. I also consider how such imagery has been received and the factors accounting for that reception. The study is contextualized by a brief, literary based, historical overview of Christian religious imagery to explain the strength of feeling evinced by religious images. This includes a review of the conflation of religion and state control of the masses, an analysis of the sovereign controls and disciplinary powers that they wield, and an explication of their illustration in religious iconography. I also identify reasons why such imagery may have seemed compelling to artists working in a post-apartheid context. By locating recent works in terms of those made elsewhere or South African examples prior to the period that is my focus, the works discussed are explored in terms of broader orientations in post-apartheid South African art. Artworks that respond to specific Christian iconography are discussed, including Adam and Eve, The Virgin Mary, Christ, and various saints and sinners. The selected artists whose works form the focus of this study are Diane Victor, Christine Dixie, Majak Bredell, Tracey Rose, Wim Botha, Conrad Botes, Johannes Phokela and Lawrence Lemaoana. Through transgressive depictions of Christian icons these artists address current inequalities in society. The content of their works analysed here includes (among others): the construction of both female and male identities; sexual roles, social roles, and racial identity; the social expectations of contemporary motherhood; repressive role models; Afrikaner heritage; political and social change and its effects; colonial power; sacrifice; murder, rape, and violence in South Africa; abuses of power by role models and politicians; rugby; heroism; and patricide. Christian iconography is a useful communicative tool because it has permeated many cultures over centuries, and the meanings it carries are thus accessible to large numbers of people. Religious imagery is often held sacred or is regarded with a degree of reverence, thus ensuring an emotive response when iconoclasm or transgression of any sort is identified. This study argues that by parodying sacred imagery these artists are able to disturb complacent viewing and encourage viewers to engage critically with some of its underlying implications.
- Full Text:
- Date Issued: 2012
Of ants and cicadas: thinking and doing
- Authors: Villet, Martin H
- Date: 2012
- Language: English
- Type: Text
- Identifier: vital:588 , http://hdl.handle.net/10962/d1018948
- Full Text:
- Date Issued: 2012
- Authors: Villet, Martin H
- Date: 2012
- Language: English
- Type: Text
- Identifier: vital:588 , http://hdl.handle.net/10962/d1018948
- Full Text:
- Date Issued: 2012
Feeding dynamics of suspension-feeders in the nearshore marine environment adjacent to two contrasting estuaries in the Eastern Cape, South Africa
- Authors: Vermeulen, Ilke
- Date: 2012
- Subjects: Suspension feeders -- South Africa -- Eastern Cape , Suspension feeders -- Food -- South Africa -- Eastern Cape , Coastal organisms -- South Africa -- Eastern Cape , Streamflow -- South Africa -- Eastern Cape , Tetraclitidae -- South Africa -- Eastern Cape , Mexilhao mussel -- South Africa -- Eastern Cape , Polychaeta -- South Africa -- Eastern Cape , Estuarine health -- South Africa -- Eastern Cape , Estuaries -- Freshwater inflow -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5916 , http://hdl.handle.net/10962/d1016242
- Description: Coastal transition zones form important interlinking regions where marine ecosystems, rivers and estuarine environments significantly influence each other. Coastal rocky shores are key habitats that sustain a variety of primary producers and invertebrates and due to the dynamic nature of coastal ecosystems, suspension-feeders on rocky shores can be influenced by an array of autochthonous and allochthonous food sources. Fatty acid and stable isotope trophic markers were employed to distinguish between regional and temporal changes in the potential food sources to rocky shore suspension-feeders in the Eastern Cape Province of South Africa. The primary aim was to assess the spatial and temporal influences of contrasting river flows on the available food sources to three indigenous coastal suspensionfeeders, namely the volcano barnacle Tetraclita serrata, brown mussel Perna perna and tubebuilding polychaete Gunnarea capensis. This was done by examining the intra- and interspecific changes in the fatty acid and stable isotope signatures of the barnacles, mussels and polychaetes in the adjacent marine environment of a freshwater-restricted (Kariega) and freshwater-dominated (Great Fish) estuary during austral summer and winter. Multivariate and Kruskal-Wallis analyses of variance on the fatty acid and isotopic signatures, respectively, identified significant regional changes in the barnacles and mussels, while only stable isotopes distinguished between the Kariega and Great Fish polychaetes (P < 0.05). In addition, significant temporal changes were observed in consumer fatty acids and isotope values in both regions (P < 0.05). Bacterial sources, detritus and phytoplankton assemblages, which are influenced by hydrology and vegetation, differed between regions and were mainly responsible for the regional and temporal separations. Principal component analyses on the consumer fatty acid signatures distinguished between animals situated upstream (i.e. north) and downstream (i.e. south) of the Kariega Estuary mouth in summer. The north/south separation was mainly due to greater contributions of diatoms to northernlocated animals and dinoflagellates and detritus to southern-located consumers. In addition, the south-flowing Agulhas Current on the eastern shores of southern Africa appeared to influence the north/south separation in the Kariega region, as water leaving the estuary was probably entrained into the south-easterly flowing currents, thereby depositing estuarinederived detritus to southern populations. In general, diatoms and detritus were essential food sources to the filter-feeders in summer, and flagellates, diatoms, zooplankton and detritus were important in winter. Coastal macroalgae was a key food source in the Kariega and Great Fish regions during both seasons. Consistently large levels of diatom markers (16:1n-7 and 20:5n-3) and dinoflagellate markers (22:6n-3) in consumer tissues in the Kariega and Great Fish regions identified that phytoplankton was their dominant food source. The barnacles, mussels and polychaetes had similar fatty acid markers and a fairly narrow δ¹³C range (-16.5 to -14.4 ‰), suggesting that they probably consumed similar food. Carbon isotope analyses, however, separated the suspension-feeders into slightly depleted (barnacles; -16.5 to -16.1 ‰), intermediate (mussels; -15.8 to -15.0 ‰) and enriched (polychaetes; -15.0 to -14.4 ‰) consumers, but did not provide conclusive evidence of their preferences for specific phytoplankton. Conversely, fatty acid analyses highlighted that barnacles and mussels had greater proportions of dinoflagellate markers (22:6n-3; 7.0-15.3 % TFA), while polychaetes had larger diatom levels (20:5n-3; 15.1-22.2 % TFA). In addition, all three species had consistently large contributions from bacterial fatty acids (15:0, i-16:0, 17:0 and i-18:0; 4.2-13.6 % TFA) in summer and winter, and large proportions of saturated fatty acids (33.3-53.1 % TFA) including those with 14 to 18 carbons, indicating that bacterial and detritus food sources played an important role in their diets. Barnacles had small levels of terrestrial markers (18:2n-6 and 18:3n-3; <2.5 % TFA) and demonstrated increased omnivorous feeding compared with the other suspension-feeders [increased levels of 20:1n-11 and 20:1n-9, higher 18:1n-9/18:1n-7 ratios at ~2.1, enriched δ¹⁵N values at ~10.6 ‰; zooplankton (potentially including microzooplankton, larvae and protists) contribution of up to 61 % of the diet]. Mussels contained significant proportions of the terrestrial markers (18:2n-6 and 18:3n-3; >2.5 % TFA) and exhibited intermediate omnivory (intermediate levels of 20:1n-11 and 20:1n-9, intermediate 18:1n-9/18:1n-7 ratios at ~1.3, less enriched δ¹⁵N values at ~7.9 ‰; zooplankton contribution of 10-15 % of the diet). The more depleted nitrogen signatures in the mussels relative to the barnacles and polychaetes possibly illustrated a stronger preference for autotrophic food. Polychaetes mainly consumed plant food sources (i.e. microalgae, macroalgae and detritus; high levels of i-18:0, 18:1n-9, 18:4n-3 and 20:5n-3) and displayed little omnivory (low levels of 20:1n-11 and 20:1n-9, low 18:1n-9/18:1n-7 ratios at ~0.4, intermediate δ¹⁵N values at ~9.1 ‰; zooplankton contribution of <10 % of the diet). The barnacles, mussels and polychaetes are all suspension-feeders, originally presumed to consume the same food sources. The variations observed among the species, therefore, may result from differences in the proportional contributions of the various food sources to their diets as well as distinctions in metabolism. The distinct changes in the fatty acid and stable isotope signatures in all three filter-feeders in the Kariega and Great Fish regions are likely influenced by the diversity in regional vegetation and hydrology in the different systems, combined with interspecific differences in resource partitioning among the species.
- Full Text:
- Date Issued: 2012
- Authors: Vermeulen, Ilke
- Date: 2012
- Subjects: Suspension feeders -- South Africa -- Eastern Cape , Suspension feeders -- Food -- South Africa -- Eastern Cape , Coastal organisms -- South Africa -- Eastern Cape , Streamflow -- South Africa -- Eastern Cape , Tetraclitidae -- South Africa -- Eastern Cape , Mexilhao mussel -- South Africa -- Eastern Cape , Polychaeta -- South Africa -- Eastern Cape , Estuarine health -- South Africa -- Eastern Cape , Estuaries -- Freshwater inflow -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5916 , http://hdl.handle.net/10962/d1016242
- Description: Coastal transition zones form important interlinking regions where marine ecosystems, rivers and estuarine environments significantly influence each other. Coastal rocky shores are key habitats that sustain a variety of primary producers and invertebrates and due to the dynamic nature of coastal ecosystems, suspension-feeders on rocky shores can be influenced by an array of autochthonous and allochthonous food sources. Fatty acid and stable isotope trophic markers were employed to distinguish between regional and temporal changes in the potential food sources to rocky shore suspension-feeders in the Eastern Cape Province of South Africa. The primary aim was to assess the spatial and temporal influences of contrasting river flows on the available food sources to three indigenous coastal suspensionfeeders, namely the volcano barnacle Tetraclita serrata, brown mussel Perna perna and tubebuilding polychaete Gunnarea capensis. This was done by examining the intra- and interspecific changes in the fatty acid and stable isotope signatures of the barnacles, mussels and polychaetes in the adjacent marine environment of a freshwater-restricted (Kariega) and freshwater-dominated (Great Fish) estuary during austral summer and winter. Multivariate and Kruskal-Wallis analyses of variance on the fatty acid and isotopic signatures, respectively, identified significant regional changes in the barnacles and mussels, while only stable isotopes distinguished between the Kariega and Great Fish polychaetes (P < 0.05). In addition, significant temporal changes were observed in consumer fatty acids and isotope values in both regions (P < 0.05). Bacterial sources, detritus and phytoplankton assemblages, which are influenced by hydrology and vegetation, differed between regions and were mainly responsible for the regional and temporal separations. Principal component analyses on the consumer fatty acid signatures distinguished between animals situated upstream (i.e. north) and downstream (i.e. south) of the Kariega Estuary mouth in summer. The north/south separation was mainly due to greater contributions of diatoms to northernlocated animals and dinoflagellates and detritus to southern-located consumers. In addition, the south-flowing Agulhas Current on the eastern shores of southern Africa appeared to influence the north/south separation in the Kariega region, as water leaving the estuary was probably entrained into the south-easterly flowing currents, thereby depositing estuarinederived detritus to southern populations. In general, diatoms and detritus were essential food sources to the filter-feeders in summer, and flagellates, diatoms, zooplankton and detritus were important in winter. Coastal macroalgae was a key food source in the Kariega and Great Fish regions during both seasons. Consistently large levels of diatom markers (16:1n-7 and 20:5n-3) and dinoflagellate markers (22:6n-3) in consumer tissues in the Kariega and Great Fish regions identified that phytoplankton was their dominant food source. The barnacles, mussels and polychaetes had similar fatty acid markers and a fairly narrow δ¹³C range (-16.5 to -14.4 ‰), suggesting that they probably consumed similar food. Carbon isotope analyses, however, separated the suspension-feeders into slightly depleted (barnacles; -16.5 to -16.1 ‰), intermediate (mussels; -15.8 to -15.0 ‰) and enriched (polychaetes; -15.0 to -14.4 ‰) consumers, but did not provide conclusive evidence of their preferences for specific phytoplankton. Conversely, fatty acid analyses highlighted that barnacles and mussels had greater proportions of dinoflagellate markers (22:6n-3; 7.0-15.3 % TFA), while polychaetes had larger diatom levels (20:5n-3; 15.1-22.2 % TFA). In addition, all three species had consistently large contributions from bacterial fatty acids (15:0, i-16:0, 17:0 and i-18:0; 4.2-13.6 % TFA) in summer and winter, and large proportions of saturated fatty acids (33.3-53.1 % TFA) including those with 14 to 18 carbons, indicating that bacterial and detritus food sources played an important role in their diets. Barnacles had small levels of terrestrial markers (18:2n-6 and 18:3n-3; <2.5 % TFA) and demonstrated increased omnivorous feeding compared with the other suspension-feeders [increased levels of 20:1n-11 and 20:1n-9, higher 18:1n-9/18:1n-7 ratios at ~2.1, enriched δ¹⁵N values at ~10.6 ‰; zooplankton (potentially including microzooplankton, larvae and protists) contribution of up to 61 % of the diet]. Mussels contained significant proportions of the terrestrial markers (18:2n-6 and 18:3n-3; >2.5 % TFA) and exhibited intermediate omnivory (intermediate levels of 20:1n-11 and 20:1n-9, intermediate 18:1n-9/18:1n-7 ratios at ~1.3, less enriched δ¹⁵N values at ~7.9 ‰; zooplankton contribution of 10-15 % of the diet). The more depleted nitrogen signatures in the mussels relative to the barnacles and polychaetes possibly illustrated a stronger preference for autotrophic food. Polychaetes mainly consumed plant food sources (i.e. microalgae, macroalgae and detritus; high levels of i-18:0, 18:1n-9, 18:4n-3 and 20:5n-3) and displayed little omnivory (low levels of 20:1n-11 and 20:1n-9, low 18:1n-9/18:1n-7 ratios at ~0.4, intermediate δ¹⁵N values at ~9.1 ‰; zooplankton contribution of <10 % of the diet). The barnacles, mussels and polychaetes are all suspension-feeders, originally presumed to consume the same food sources. The variations observed among the species, therefore, may result from differences in the proportional contributions of the various food sources to their diets as well as distinctions in metabolism. The distinct changes in the fatty acid and stable isotope signatures in all three filter-feeders in the Kariega and Great Fish regions are likely influenced by the diversity in regional vegetation and hydrology in the different systems, combined with interspecific differences in resource partitioning among the species.
- Full Text:
- Date Issued: 2012