A cytotoxic pentadecapeptide from a South African Didemnid tunicate
- Gallegos, D, Serrill, J, Parker-Nance, Shirley, Dorrington, Rosemary A, Ishmael, J, McPhail, Kerry L
- Authors: Gallegos, D , Serrill, J , Parker-Nance, Shirley , Dorrington, Rosemary A , Ishmael, J , McPhail, Kerry L
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/65935 , vital:28863 , https://doi.org/10.1055/s-0036-1596683
- Description: publisher version , The rate of discovery of new natural product chemical entities has plateaued, and unique populations of endemic, biologically diverse sessile marine organisms represent increasingly critical opportunities to discover new chemistry. Discovery of the mandelalides [1] as potent inhibitors of cancer cell growth from the new South African tunicate Lissoclinum mandelai is an example of the diverse suites of metabolites with potent biological activities that have been isolated from tunicates and other filter-feeding sessile marine organisms that house complex microbial consortia. Further investigation of archived and new tunicate collections from Algoa Bay, South Africa, has revealed a group of didemnid tunicates with an unusual gelatinous morphology similar to Lissoclinum mandelai. Using a bioassay-guided isolation approach, a new “gelatinous” species of the genus Didemnum has yielded a cytotoxic pentadecapeptide with a molecular mass of 1603.7688 Da, comprising fifteen residues including both proteinogenic and non-proteinogenic amino acids. The pure compound inhibited both HeLa cervical cancer and NCI-H460 non-small cell lung cancer cell lines when tested at 30 nM in preliminary assays against cells seeded at low densities. Inhibition of cancer cells at low starting density may be indicative of an anti-proliferative mechanism of action. The compound did not show antibacterial activity against Vibrio cholera. Didemnin B and its clinically approved analogue dehydrodidemnin B (plitidepsin, Aplidin®) [2, 3] are important macrocyclic depsipeptides from a didemnid tunicate. The pentadecapeptide reported here provides justification for our continued investigation of unique, endemic didemnid tunicates from South Africa as a source of new macrocyclic natural products with cytotoxic, anti-viral or antimicrobial activity. , We acknowledge the South African government for permission to collect the subject tunicate (Collection Permit No. 278 RES2013/43)
- Full Text: false
- Date Issued: 2016
- Authors: Gallegos, D , Serrill, J , Parker-Nance, Shirley , Dorrington, Rosemary A , Ishmael, J , McPhail, Kerry L
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/65935 , vital:28863 , https://doi.org/10.1055/s-0036-1596683
- Description: publisher version , The rate of discovery of new natural product chemical entities has plateaued, and unique populations of endemic, biologically diverse sessile marine organisms represent increasingly critical opportunities to discover new chemistry. Discovery of the mandelalides [1] as potent inhibitors of cancer cell growth from the new South African tunicate Lissoclinum mandelai is an example of the diverse suites of metabolites with potent biological activities that have been isolated from tunicates and other filter-feeding sessile marine organisms that house complex microbial consortia. Further investigation of archived and new tunicate collections from Algoa Bay, South Africa, has revealed a group of didemnid tunicates with an unusual gelatinous morphology similar to Lissoclinum mandelai. Using a bioassay-guided isolation approach, a new “gelatinous” species of the genus Didemnum has yielded a cytotoxic pentadecapeptide with a molecular mass of 1603.7688 Da, comprising fifteen residues including both proteinogenic and non-proteinogenic amino acids. The pure compound inhibited both HeLa cervical cancer and NCI-H460 non-small cell lung cancer cell lines when tested at 30 nM in preliminary assays against cells seeded at low densities. Inhibition of cancer cells at low starting density may be indicative of an anti-proliferative mechanism of action. The compound did not show antibacterial activity against Vibrio cholera. Didemnin B and its clinically approved analogue dehydrodidemnin B (plitidepsin, Aplidin®) [2, 3] are important macrocyclic depsipeptides from a didemnid tunicate. The pentadecapeptide reported here provides justification for our continued investigation of unique, endemic didemnid tunicates from South Africa as a source of new macrocyclic natural products with cytotoxic, anti-viral or antimicrobial activity. , We acknowledge the South African government for permission to collect the subject tunicate (Collection Permit No. 278 RES2013/43)
- Full Text: false
- Date Issued: 2016
Electrocatalytic activity of nanocomposites of sulphur doped graphene oxide and nanosized cobalt phthalocyanines
- Shumba, Munyaradzi, Nyokong, Tebello
- Authors: Shumba, Munyaradzi , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188530 , vital:44762 , xlink:href="https://doi.org/10.1002/elan.201600226"
- Description: In this work we explore the electrocatalytic activity of nanocomposites of reduced sulphur doped graphene oxide nanosheets (rSDGONS) and cobalt phthalocyanine (CoPc) or cobalt tetra amino phthalocyanine (CoTAPc) towards hydrogen peroxide. Transmission electron microscopy, scanning electron microscopy, X-ray photon spectroscopy, X-ray diffraction, chronoamperometry, linear scan voltammetry and cyclic voltammetry were used to characterize the nanocomposites. Nanosized CoPc showed superior (in terms of currents) electrocatalytic oxidation and reduction of hydrogen peroxide compared to CoTAPc nanoparticles (CoTAPcNP). The lowest detection limit was obtained for hydrogen peroxide oxidation on electrodes modified with CoPcNP-rSDGONS at 1.49 µM. The same electrode gave a high adsorption equilibrium constant of 1.27×103 mol−1 and a Gibbs free energy of −17.71 kJ/mol, indicative of a spontaneous reaction on the electrode surface.
- Full Text:
- Date Issued: 2016
- Authors: Shumba, Munyaradzi , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188530 , vital:44762 , xlink:href="https://doi.org/10.1002/elan.201600226"
- Description: In this work we explore the electrocatalytic activity of nanocomposites of reduced sulphur doped graphene oxide nanosheets (rSDGONS) and cobalt phthalocyanine (CoPc) or cobalt tetra amino phthalocyanine (CoTAPc) towards hydrogen peroxide. Transmission electron microscopy, scanning electron microscopy, X-ray photon spectroscopy, X-ray diffraction, chronoamperometry, linear scan voltammetry and cyclic voltammetry were used to characterize the nanocomposites. Nanosized CoPc showed superior (in terms of currents) electrocatalytic oxidation and reduction of hydrogen peroxide compared to CoTAPc nanoparticles (CoTAPcNP). The lowest detection limit was obtained for hydrogen peroxide oxidation on electrodes modified with CoPcNP-rSDGONS at 1.49 µM. The same electrode gave a high adsorption equilibrium constant of 1.27×103 mol−1 and a Gibbs free energy of −17.71 kJ/mol, indicative of a spontaneous reaction on the electrode surface.
- Full Text:
- Date Issued: 2016
A marketing framework to enhance healthcare professionals' prescription for specialised infant formula
- Authors: Jordaan, Josina Hermeine
- Date: 2016
- Subjects: Marketing , Infant formulas , Medicine -- Formulae, receipts, prescriptions
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/8340 , vital:26346
- Description: The marketing of infant feeding products is almost impossible as the infant nutrition industry is highly regulated. Despite operating under strict regulations, the infant formula manufacturing companies still generate high revenues on an annual basis. The infant formula manufacturing industry operates under a value chain which can be broken down into six sequential steps. These steps are: (1) Translational science; (2) Product development; (3) Clinical research; (4) Product notification; (5) Reimbursement granting and (6) Product marketing. Medical nutrition companies aspire to understand product requirements of healthcare professionals and medical representatives. This is to enable direct investment to acquire market share without wasting resources. The medical nutrition industry currently makes use of medical representatives to execute product marketing. Manufacturing companies invest a lot of money into developing their products, employing and training medical representatives and trust that this will be enough to persuade healthcare professionals to recommend their products to parents. This study analyses the main contributing factors that enhance prescription of specialised infant formula by healthcare professionals. This study was conducted in a positivistic paradigm by making use of a quantitative approach. Healthcare professionals from Port Elizabeth, working with paediatric patients were included in this study. The healthcare professionals were chosen by a convenience sampling method and were then interviewed. The empirical interview results were substantiated with the interpretive findings which were in the form of verbatim statements extracted directly from the research questionnaire. Linkage between the dependable variable (prescription) and independent variables (manufacturing company; product composition; cost of product; medical representative and peers) were established and analysed. The research revealed that prescription behaviour is an important construct which can be measured in medical practices. Prescription behaviour is correlated with positive business and medical outcomes and manufacturing companies are able to exert influence over it through the identified variables. Of these variables, efficacy of vii a product, trusted manufacturing company and the medical representatives were found to have direct and significant effects. Healthcare professionals tend to prescribe a specialised infant formula if they have seen results and trust the outcome of the product. It is advisable for manufacturing companies to exert great effort before appointing a medical representative, to make sure that the right candidate represents the face of the company.
- Full Text:
- Date Issued: 2016
- Authors: Jordaan, Josina Hermeine
- Date: 2016
- Subjects: Marketing , Infant formulas , Medicine -- Formulae, receipts, prescriptions
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/8340 , vital:26346
- Description: The marketing of infant feeding products is almost impossible as the infant nutrition industry is highly regulated. Despite operating under strict regulations, the infant formula manufacturing companies still generate high revenues on an annual basis. The infant formula manufacturing industry operates under a value chain which can be broken down into six sequential steps. These steps are: (1) Translational science; (2) Product development; (3) Clinical research; (4) Product notification; (5) Reimbursement granting and (6) Product marketing. Medical nutrition companies aspire to understand product requirements of healthcare professionals and medical representatives. This is to enable direct investment to acquire market share without wasting resources. The medical nutrition industry currently makes use of medical representatives to execute product marketing. Manufacturing companies invest a lot of money into developing their products, employing and training medical representatives and trust that this will be enough to persuade healthcare professionals to recommend their products to parents. This study analyses the main contributing factors that enhance prescription of specialised infant formula by healthcare professionals. This study was conducted in a positivistic paradigm by making use of a quantitative approach. Healthcare professionals from Port Elizabeth, working with paediatric patients were included in this study. The healthcare professionals were chosen by a convenience sampling method and were then interviewed. The empirical interview results were substantiated with the interpretive findings which were in the form of verbatim statements extracted directly from the research questionnaire. Linkage between the dependable variable (prescription) and independent variables (manufacturing company; product composition; cost of product; medical representative and peers) were established and analysed. The research revealed that prescription behaviour is an important construct which can be measured in medical practices. Prescription behaviour is correlated with positive business and medical outcomes and manufacturing companies are able to exert influence over it through the identified variables. Of these variables, efficacy of vii a product, trusted manufacturing company and the medical representatives were found to have direct and significant effects. Healthcare professionals tend to prescribe a specialised infant formula if they have seen results and trust the outcome of the product. It is advisable for manufacturing companies to exert great effort before appointing a medical representative, to make sure that the right candidate represents the face of the company.
- Full Text:
- Date Issued: 2016
Vocational curriculum report 191(NATED) as a curriculum: a case study of three Eastern Cape TVET Colleges
- Authors: Sixabayi, Siyabonga Prince
- Date: 2016
- Subjects: Vocational education -- Curricula -- South Africa -- Eastern Cape Curriculum planning -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , Degree
- Identifier: http://hdl.handle.net/10353/5126 , vital:29089
- Description: This study aimed to investigate if there are any possible gaps in the offering Vocational Curriculum Report 191, in terms of knowledge, skills and link to the world of work. This study was a case study of three Technical and Vocational Education and Training Colleges that offer Vocational Curriculum Report 191, and it was geographically limited to the province of the Eastern Cape. The five main findings from this study were that firstly, the curriculum offers theory without practice. Secondly, there is a mismatch between what is offered as curriculum at Technical and Vocational Education and Training Colleges and what the labour market wants. Thirdly, lecturers do not have the practical exposure that relates to their fields of study. Fourthly, Vocational Curriculum Report 191 does not promote self-employment of its students and lastly, the curriculum is outdated and does not comply with the criteria of current employment opportunities. The study recommends that the curriculum be reviewed and revised. Technical and Vocational Education and Training colleges need to have in site practice facilities to cater for the practical application of theoretical knowledge of students. Partnerships between Technical and Vocational Education and Training Colleges, the labour market and Sector Education and Training Authorities are strongly recommended in this study.
- Full Text:
- Date Issued: 2016
- Authors: Sixabayi, Siyabonga Prince
- Date: 2016
- Subjects: Vocational education -- Curricula -- South Africa -- Eastern Cape Curriculum planning -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , Degree
- Identifier: http://hdl.handle.net/10353/5126 , vital:29089
- Description: This study aimed to investigate if there are any possible gaps in the offering Vocational Curriculum Report 191, in terms of knowledge, skills and link to the world of work. This study was a case study of three Technical and Vocational Education and Training Colleges that offer Vocational Curriculum Report 191, and it was geographically limited to the province of the Eastern Cape. The five main findings from this study were that firstly, the curriculum offers theory without practice. Secondly, there is a mismatch between what is offered as curriculum at Technical and Vocational Education and Training Colleges and what the labour market wants. Thirdly, lecturers do not have the practical exposure that relates to their fields of study. Fourthly, Vocational Curriculum Report 191 does not promote self-employment of its students and lastly, the curriculum is outdated and does not comply with the criteria of current employment opportunities. The study recommends that the curriculum be reviewed and revised. Technical and Vocational Education and Training colleges need to have in site practice facilities to cater for the practical application of theoretical knowledge of students. Partnerships between Technical and Vocational Education and Training Colleges, the labour market and Sector Education and Training Authorities are strongly recommended in this study.
- Full Text:
- Date Issued: 2016
Perceived decision making factors in the use of traditional and alternative medicine for people living with HIV and AIDS
- Authors: Muromo, Tinashe
- Date: 2016
- Subjects: Decision making , HIV-positive persons -- Attitudes , Social influence
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/5687 , vital:20963
- Description: AIDS is one of the most destructive diseases humankind has ever faced and also brings with it profound social, economic and public health consequences, making it one of the most serious health and development challenges in the world today. Zimbabwe, situated in southeastern Africa, is not spared from the pandemic. It continues to be one of the Sub-SaharanAfrican countries mostly heavily impacted by the AIDS epidemic, with almost 1.2 million people infected and over 1.1 million orphans. It ranks, therefore, as fifth highest in the world in the impact HIV and AIDS has had on the country. The most effective response has been to introduce programmes to reduce the number of new infections. Recent research has demonstrated treatment as a preventative measure to be very effective. This approach involves targeting those who are infected so that they are not able to transmit the disease. The decision that has to be made by an infected person, however, is whether to look for traditional treatment, conventional treatment or a combination of the two. Herbal medicine use is becoming very common in many countries, especially in the developing world, where public health safety has become a concern. It has become common to use herbal medicine concomitantly with allopathic or conventional medicine. The present study focused on investigating perceptions leading to the choice of treatment with the traditional alternative medicines (TAM) as (a)/n alternative or compliment to the conventional or allopathic option. This is a qualitative study that explores and describes participant’s perceptions, beliefs, attitudes and feelings around the use of traditional medicine, within the context of the Integrative Behaviour Model (IBM). Data was collected from 20 people living with HIV and AIDS from urban and rural settings of different ethnicities (Shona and Shangani). The data analysis was informed by The Interpretive Phenomenological Analysis with the aid of NVivo (V.10), a computer-assisted Qualitative Data Analysis Software. As predicted by the IBM, both perceived individual and environmental factors were found to be key in influencing decision-making on the use of TAM by people living with HIV and AIDS. Although there were a number of incidents in which either individual or environmental factors were perceived as independently influencing the TAM-use decision-making process, there was a lot of mutual influence between the environment and the individual. Such mutual causation was abstracted as reciprocal determinism. The IMB model assumed a unidirectional causation in which the environment could affect the individual factors. While the present study identified and demonstrated these environmental effects on the individual, it also identified and presented a reverse causation in which the individual would also affect the environment with respect to motivation for TAM use. Individual factors were psychological properties that drove the individual to use TAM. Attitude, social influence and personal agency emerged as the three dimensions of individual factors. Attitudes helped in identification of orientations that located objects of thought on dimensions of judgment about the use of TAM. Social influence explained social pressure experienced and expected regarding the use of TAM. The study demonstrated the importance of both the descriptive and injunctive norm with participants indicating that they perceived important others to be using traditional medicine and that they felt perceived expectations from others to do the same and hence the motivation to comply. Personal agency pointed to the participants’ capacities to originate and direct actions for the purposes of TAM use. All these constructs were found to be very important as perceived determinants of the behavioral intentions of people living with HIV and AIDS to use traditional medicines. In experiential attitude, generally the respondents showed more perceived positive evaluations of pleasurable experiences in their use of traditional medicines. However, there were other outcome evaluations that seemed to be ambivalent and which appeared to cause a lot of tension. The comprehension of experiential attitude was found therefore found to be trichotomous rather than dichotomous as per the IBM. The effects of the instrumental attitude were revealed in the ratings of the extent to which the use of traditional medicine was perceived as useful or rewarding, with the study revealing high ratings of usefulness. It becomes clear, therefore, that for people living with HIV and AIDS social influence, perceived attitudes and personal agency are important decision-making factors in their use of traditional and alternative medicine. Efforts towards education, integration and behaviour change programmes should design messages targeting these behavioral determinants. Understanding of these perceived determinants is crucial to influencing policy as well as the adoption of health practices through education, marketing and other modes of health promotion.
- Full Text:
- Date Issued: 2016
- Authors: Muromo, Tinashe
- Date: 2016
- Subjects: Decision making , HIV-positive persons -- Attitudes , Social influence
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/5687 , vital:20963
- Description: AIDS is one of the most destructive diseases humankind has ever faced and also brings with it profound social, economic and public health consequences, making it one of the most serious health and development challenges in the world today. Zimbabwe, situated in southeastern Africa, is not spared from the pandemic. It continues to be one of the Sub-SaharanAfrican countries mostly heavily impacted by the AIDS epidemic, with almost 1.2 million people infected and over 1.1 million orphans. It ranks, therefore, as fifth highest in the world in the impact HIV and AIDS has had on the country. The most effective response has been to introduce programmes to reduce the number of new infections. Recent research has demonstrated treatment as a preventative measure to be very effective. This approach involves targeting those who are infected so that they are not able to transmit the disease. The decision that has to be made by an infected person, however, is whether to look for traditional treatment, conventional treatment or a combination of the two. Herbal medicine use is becoming very common in many countries, especially in the developing world, where public health safety has become a concern. It has become common to use herbal medicine concomitantly with allopathic or conventional medicine. The present study focused on investigating perceptions leading to the choice of treatment with the traditional alternative medicines (TAM) as (a)/n alternative or compliment to the conventional or allopathic option. This is a qualitative study that explores and describes participant’s perceptions, beliefs, attitudes and feelings around the use of traditional medicine, within the context of the Integrative Behaviour Model (IBM). Data was collected from 20 people living with HIV and AIDS from urban and rural settings of different ethnicities (Shona and Shangani). The data analysis was informed by The Interpretive Phenomenological Analysis with the aid of NVivo (V.10), a computer-assisted Qualitative Data Analysis Software. As predicted by the IBM, both perceived individual and environmental factors were found to be key in influencing decision-making on the use of TAM by people living with HIV and AIDS. Although there were a number of incidents in which either individual or environmental factors were perceived as independently influencing the TAM-use decision-making process, there was a lot of mutual influence between the environment and the individual. Such mutual causation was abstracted as reciprocal determinism. The IMB model assumed a unidirectional causation in which the environment could affect the individual factors. While the present study identified and demonstrated these environmental effects on the individual, it also identified and presented a reverse causation in which the individual would also affect the environment with respect to motivation for TAM use. Individual factors were psychological properties that drove the individual to use TAM. Attitude, social influence and personal agency emerged as the three dimensions of individual factors. Attitudes helped in identification of orientations that located objects of thought on dimensions of judgment about the use of TAM. Social influence explained social pressure experienced and expected regarding the use of TAM. The study demonstrated the importance of both the descriptive and injunctive norm with participants indicating that they perceived important others to be using traditional medicine and that they felt perceived expectations from others to do the same and hence the motivation to comply. Personal agency pointed to the participants’ capacities to originate and direct actions for the purposes of TAM use. All these constructs were found to be very important as perceived determinants of the behavioral intentions of people living with HIV and AIDS to use traditional medicines. In experiential attitude, generally the respondents showed more perceived positive evaluations of pleasurable experiences in their use of traditional medicines. However, there were other outcome evaluations that seemed to be ambivalent and which appeared to cause a lot of tension. The comprehension of experiential attitude was found therefore found to be trichotomous rather than dichotomous as per the IBM. The effects of the instrumental attitude were revealed in the ratings of the extent to which the use of traditional medicine was perceived as useful or rewarding, with the study revealing high ratings of usefulness. It becomes clear, therefore, that for people living with HIV and AIDS social influence, perceived attitudes and personal agency are important decision-making factors in their use of traditional and alternative medicine. Efforts towards education, integration and behaviour change programmes should design messages targeting these behavioral determinants. Understanding of these perceived determinants is crucial to influencing policy as well as the adoption of health practices through education, marketing and other modes of health promotion.
- Full Text:
- Date Issued: 2016
Protection of personal information in the South African cloud computing environment: a framework for cloud computing adoption
- Authors: Skolmen, Dayne Edward
- Date: 2016
- Subjects: Cloud computing -- Security measures Data protection -- Law and legislation -- South Africa , Privacy, Right of
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/12747 , vital:27117
- Description: Cloud Computing has advanced to the point where it may be considered an attractive proposition for an increasing number of South African organisations, yet the adoption of Cloud Computing in South Africa remains relatively low. Many organisations have been hesitant to adopt Cloud solutions owing to a variety of inhibiting factors and concerns that have created mistrust in Cloud Computing. One of the top concerns identified is security within the Cloud Computing environment. The approaching commencement of new data protection legislation in South Africa, known as the Protection of Personal Information Act (POPI), may provide an ideal opportunity to address the information security-related inhibiting factors and foster a trust relationship between potential Cloud users and Cloud providers. POPI applies to anyone who processes personal information and regulates how they must handle, store and secure that information. POPI is considered to be beneficial to Cloud providers as it gives them the opportunity to build trust with potential Cloud users through achieving compliance and providing assurance. The aim of this dissertation is, therefore, to develop a framework for Cloud Computing adoption that will assist in mitigating the information security-related factors inhibiting Cloud adoption by fostering a trust relationship through compliance with the POPI Act. It is believed that such a framework would be useful to South African Cloud providers and could ultimately assist in the promotion of Cloud adoption in South Africa.
- Full Text:
- Date Issued: 2016
- Authors: Skolmen, Dayne Edward
- Date: 2016
- Subjects: Cloud computing -- Security measures Data protection -- Law and legislation -- South Africa , Privacy, Right of
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/12747 , vital:27117
- Description: Cloud Computing has advanced to the point where it may be considered an attractive proposition for an increasing number of South African organisations, yet the adoption of Cloud Computing in South Africa remains relatively low. Many organisations have been hesitant to adopt Cloud solutions owing to a variety of inhibiting factors and concerns that have created mistrust in Cloud Computing. One of the top concerns identified is security within the Cloud Computing environment. The approaching commencement of new data protection legislation in South Africa, known as the Protection of Personal Information Act (POPI), may provide an ideal opportunity to address the information security-related inhibiting factors and foster a trust relationship between potential Cloud users and Cloud providers. POPI applies to anyone who processes personal information and regulates how they must handle, store and secure that information. POPI is considered to be beneficial to Cloud providers as it gives them the opportunity to build trust with potential Cloud users through achieving compliance and providing assurance. The aim of this dissertation is, therefore, to develop a framework for Cloud Computing adoption that will assist in mitigating the information security-related factors inhibiting Cloud adoption by fostering a trust relationship through compliance with the POPI Act. It is believed that such a framework would be useful to South African Cloud providers and could ultimately assist in the promotion of Cloud adoption in South Africa.
- Full Text:
- Date Issued: 2016
Spectroscopic investigations and theoretical calculations of DABCO induced xanthene bridged self-assembled zinc (II) porphyrin dimer
- Xu, Li, Huang, Tingting, Liang, Xu, Mack, John, Harris, Jessica, Nyokong, Tebello, Li, Minzhi, Zhu, Weihua
- Authors: Xu, Li , Huang, Tingting , Liang, Xu , Mack, John , Harris, Jessica , Nyokong, Tebello , Li, Minzhi , Zhu, Weihua
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240732 , vital:50866 , xlink:href="https://doi.org/10.1142/S1088424616500231"
- Description: An in-depth study of the electronic structure of a 1,4-diazabicyclo[2.2.2]octane (DABCO) induced molecular self-assembled xanthene-bridged and amide-bonded porphyrin dimer is reported. Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations are used to identify trends in the optical spectroscopic properties. B3LYP geometry optimization predicts the formation of an almost perfectly eclipsed structure with respect to the two porphyrin rings with the analogous pyrrole nitrogens separated by 7.7–8.1 Å. The observed distinctive derivative-shaped band morphology of the pseudo-Faraday-A11 terms in the MCD spectra has been used to identify the main electronic Q and B-bands and to validate the TD-DFT calculations. The absence of a discernible splitting of the redox steps or a quenching of the fluorescence demonstrates that there is no significant exciton coupling between the two porphyrin rings.
- Full Text:
- Date Issued: 2016
- Authors: Xu, Li , Huang, Tingting , Liang, Xu , Mack, John , Harris, Jessica , Nyokong, Tebello , Li, Minzhi , Zhu, Weihua
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240732 , vital:50866 , xlink:href="https://doi.org/10.1142/S1088424616500231"
- Description: An in-depth study of the electronic structure of a 1,4-diazabicyclo[2.2.2]octane (DABCO) induced molecular self-assembled xanthene-bridged and amide-bonded porphyrin dimer is reported. Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations are used to identify trends in the optical spectroscopic properties. B3LYP geometry optimization predicts the formation of an almost perfectly eclipsed structure with respect to the two porphyrin rings with the analogous pyrrole nitrogens separated by 7.7–8.1 Å. The observed distinctive derivative-shaped band morphology of the pseudo-Faraday-A11 terms in the MCD spectra has been used to identify the main electronic Q and B-bands and to validate the TD-DFT calculations. The absence of a discernible splitting of the redox steps or a quenching of the fluorescence demonstrates that there is no significant exciton coupling between the two porphyrin rings.
- Full Text:
- Date Issued: 2016
Introducing and intervention programme for grade 2 Afrikaans home language learners with reading, comprehension and phonics barriers
- De Jager, Marina, Geldenhuys, Johanna
- Authors: De Jager, Marina , Geldenhuys, Johanna
- Date: 2016
- Subjects: Holistic education -- South Africa , Inclusive education -- South Africa , Remedial teaching -- South Africa , Language and education -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10948/6801 , vital:21143
- Description: This research study was aimed at the Grade 2 Afrikaans Home Language learners who encounter reading, comprehension and phonics barriers in an inclusive classroom. The Grade 2 Curriculum and Assessment Policy Statement (CAPS) Home Language curriculum and pass requirements that the learners have to master in the mainstream, was a major concern. Consequently, seventy per cent of the Grade 2 Afrikaans learners have already failed Grade 1 or 2; and some seemed to be borderline cases; as their pace of development was so slow. The intervention programme was implemented intensively outside normal school hours, through qualitative and quantitative data collection, known as the multi-method. The research approaches were conducted through action research and case-study research. Bronfenbrenner’s model indicated that intrinsic and extrinsic factors cannot be disregarded in the learner’s holistic development; therefore, parent involvement was vital during the research study. As the Individual Learner Support Team (ILST) coordinator at the research school, I have experienced the despair and perplexity of the teachers, when dealing with teaching challenges; but also, that of the learners, who face barriers to learning. A sample of six learners was identified; and one parent in each household was active during the study. The parent’s responses varied from limited to worthy feedback throughout the intervention programme. The learners’ responses were observed during the intervention programme, the classroom situation; and their perceptions during the semi-structured interviews were recorded. The intervention programme links with the Screening, Identification, Assessment and Support of SIAS process; and it involved the assistance of a remedial expert by applying remedial education, without psychometric tests. The findings revealed that the learner must be intrinsically motivated to co-operate fully. And this relates to both intrinsic and extrinsic influences. Recommendations are offered to the various stakeholders, who are directly or indirectly engaged in the learner’s scholastic development, to ensure corrective and supportive measures, which are conducive to learning.
- Full Text:
- Date Issued: 2016
- Authors: De Jager, Marina , Geldenhuys, Johanna
- Date: 2016
- Subjects: Holistic education -- South Africa , Inclusive education -- South Africa , Remedial teaching -- South Africa , Language and education -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10948/6801 , vital:21143
- Description: This research study was aimed at the Grade 2 Afrikaans Home Language learners who encounter reading, comprehension and phonics barriers in an inclusive classroom. The Grade 2 Curriculum and Assessment Policy Statement (CAPS) Home Language curriculum and pass requirements that the learners have to master in the mainstream, was a major concern. Consequently, seventy per cent of the Grade 2 Afrikaans learners have already failed Grade 1 or 2; and some seemed to be borderline cases; as their pace of development was so slow. The intervention programme was implemented intensively outside normal school hours, through qualitative and quantitative data collection, known as the multi-method. The research approaches were conducted through action research and case-study research. Bronfenbrenner’s model indicated that intrinsic and extrinsic factors cannot be disregarded in the learner’s holistic development; therefore, parent involvement was vital during the research study. As the Individual Learner Support Team (ILST) coordinator at the research school, I have experienced the despair and perplexity of the teachers, when dealing with teaching challenges; but also, that of the learners, who face barriers to learning. A sample of six learners was identified; and one parent in each household was active during the study. The parent’s responses varied from limited to worthy feedback throughout the intervention programme. The learners’ responses were observed during the intervention programme, the classroom situation; and their perceptions during the semi-structured interviews were recorded. The intervention programme links with the Screening, Identification, Assessment and Support of SIAS process; and it involved the assistance of a remedial expert by applying remedial education, without psychometric tests. The findings revealed that the learner must be intrinsically motivated to co-operate fully. And this relates to both intrinsic and extrinsic influences. Recommendations are offered to the various stakeholders, who are directly or indirectly engaged in the learner’s scholastic development, to ensure corrective and supportive measures, which are conducive to learning.
- Full Text:
- Date Issued: 2016
Cytotoxic activity of marine sponge extracts from the sub-Antarctic Islands and the Southern Ocean
- Olsen, Elisabeth, De Cerf, Christopher, Dziwornu, Godwin, Puccinelli, Eleonora, Parker-Nance, Shirley, Ansorge, Isabelle J, Samaai, Toufiek, Dingle, Laura, Edkins, Adrienne L, Sunassee, Suthananda N
- Authors: Olsen, Elisabeth , De Cerf, Christopher , Dziwornu, Godwin , Puccinelli, Eleonora , Parker-Nance, Shirley , Ansorge, Isabelle J , Samaai, Toufiek , Dingle, Laura , Edkins, Adrienne L , Sunassee, Suthananda N
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66300 , vital:28931 , https://doi.org/10.17159/sajs.2016/20160202
- Description: publisher version , Over the past 50 years, marine invertebrates, especially sponges, have proven to be a valuable source of new and/or bioactive natural products that have the potential to be further developed as lead compounds for pharmaceutical applications. Although marine benthic invertebrate communities occurring off the coast of South Africa have been explored for their biomedicinal potential, the natural product investigation of marine sponges from the sub-Antarctic Islands in the Southern Ocean for the presence of bioactive secondary metabolites has been relatively unexplored thus far. We report here the results for the biological screening of both aqueous and organic extracts prepared from nine specimens of eight species of marine sponges, collected from around Marion Island and the Prince Edward Islands in the Southern Ocean, for their cytotoxic activity against three cancer cell lines. The results obtained through this multidisciplinary collaborative research effort by exclusively South African institutions has provided an exciting opportunity to discover cytotoxic compounds from sub-Antarctic sponges, whilst contributing to our understanding of the biodiversity and geographic distributions of these cold-water invertebrates. Therefore, we acknowledge here the various contributions of the diverse scientific disciplines that played a pivotal role in providing the necessary platform for the future natural products chemistry investigation of these marine sponges from the sub- Antarctic Islands and the Southern Ocean. Significance: This study will contribute to understanding the biodiversity and geographic distributions of sponges in the Southern Ocean. This multidisciplinary project has enabled the investigation of marine sponges for the presence of cytotoxic compounds. Further investigation will lead to the isolation and identification of cytotoxic compounds present in the active sponge extracts. , University of Cape Town; South African Medical Research Council; National Research Foundation (South Africa); CANSA; Rhodes University; Department of Science and Technology; Department of Environmental Affairs; SANAP
- Full Text:
- Date Issued: 2016
- Authors: Olsen, Elisabeth , De Cerf, Christopher , Dziwornu, Godwin , Puccinelli, Eleonora , Parker-Nance, Shirley , Ansorge, Isabelle J , Samaai, Toufiek , Dingle, Laura , Edkins, Adrienne L , Sunassee, Suthananda N
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66300 , vital:28931 , https://doi.org/10.17159/sajs.2016/20160202
- Description: publisher version , Over the past 50 years, marine invertebrates, especially sponges, have proven to be a valuable source of new and/or bioactive natural products that have the potential to be further developed as lead compounds for pharmaceutical applications. Although marine benthic invertebrate communities occurring off the coast of South Africa have been explored for their biomedicinal potential, the natural product investigation of marine sponges from the sub-Antarctic Islands in the Southern Ocean for the presence of bioactive secondary metabolites has been relatively unexplored thus far. We report here the results for the biological screening of both aqueous and organic extracts prepared from nine specimens of eight species of marine sponges, collected from around Marion Island and the Prince Edward Islands in the Southern Ocean, for their cytotoxic activity against three cancer cell lines. The results obtained through this multidisciplinary collaborative research effort by exclusively South African institutions has provided an exciting opportunity to discover cytotoxic compounds from sub-Antarctic sponges, whilst contributing to our understanding of the biodiversity and geographic distributions of these cold-water invertebrates. Therefore, we acknowledge here the various contributions of the diverse scientific disciplines that played a pivotal role in providing the necessary platform for the future natural products chemistry investigation of these marine sponges from the sub- Antarctic Islands and the Southern Ocean. Significance: This study will contribute to understanding the biodiversity and geographic distributions of sponges in the Southern Ocean. This multidisciplinary project has enabled the investigation of marine sponges for the presence of cytotoxic compounds. Further investigation will lead to the isolation and identification of cytotoxic compounds present in the active sponge extracts. , University of Cape Town; South African Medical Research Council; National Research Foundation (South Africa); CANSA; Rhodes University; Department of Science and Technology; Department of Environmental Affairs; SANAP
- Full Text:
- Date Issued: 2016
Experiences of newly qualified south african psychologists dealing with suicidal behaviour
- Authors: Cramer, Ryan
- Date: 2016
- Subjects: Suicidal behavior , Suicide Psychotherapy Suicide -- Prevention
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/5677 , vital:20962
- Description: Suicidal behaviour is a phenomenon encountered the world over. Recognising and adequately dealing with such behaviours, in a professional setting, is a role expected of a psychologist. Working with suicidal behaviour is influenced by a variety of factors on the part of the psychologist. These may include, inter alia, experiences they may have had with suicidal behaviour, the training they have received in order to deal with such behaviours and their subjective experience of self-efficacy in dealing with such behaviours. The current qualitative study sought to explore and describe the experiences of recently qualified South African psychologists in dealing with suicidal behaviour through semi-structured interviews. The focus was on newly qualified clinical psychologists who received their masters training at a university in the Eastern Cape Province of South Africa. The study aimed to understand how confident, equipped, and ready newly qualified psychologists perceived themselves in dealing with suicidal behaviour. Three major themes emerged from the data. The first describes the strategies psychologists used in order to recognise potential suicidal behaviour, the second was how newly qualified psychologists managed suicidal behaviour, and the final theme described how psychologists could be prepared for their role to deal effectively with these behaviours. Investigating their experiences enabled the participants to contribute towards creating knowledge in this crucial area of psychological practice and allowed for the discovery of invaluable insights which could benefit the future training of psychologists.
- Full Text:
- Date Issued: 2016
- Authors: Cramer, Ryan
- Date: 2016
- Subjects: Suicidal behavior , Suicide Psychotherapy Suicide -- Prevention
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/5677 , vital:20962
- Description: Suicidal behaviour is a phenomenon encountered the world over. Recognising and adequately dealing with such behaviours, in a professional setting, is a role expected of a psychologist. Working with suicidal behaviour is influenced by a variety of factors on the part of the psychologist. These may include, inter alia, experiences they may have had with suicidal behaviour, the training they have received in order to deal with such behaviours and their subjective experience of self-efficacy in dealing with such behaviours. The current qualitative study sought to explore and describe the experiences of recently qualified South African psychologists in dealing with suicidal behaviour through semi-structured interviews. The focus was on newly qualified clinical psychologists who received their masters training at a university in the Eastern Cape Province of South Africa. The study aimed to understand how confident, equipped, and ready newly qualified psychologists perceived themselves in dealing with suicidal behaviour. Three major themes emerged from the data. The first describes the strategies psychologists used in order to recognise potential suicidal behaviour, the second was how newly qualified psychologists managed suicidal behaviour, and the final theme described how psychologists could be prepared for their role to deal effectively with these behaviours. Investigating their experiences enabled the participants to contribute towards creating knowledge in this crucial area of psychological practice and allowed for the discovery of invaluable insights which could benefit the future training of psychologists.
- Full Text:
- Date Issued: 2016
Docking of HIV protease to silver nanoparticles
- Whiteley, Chris G, Shing, C-Y, Kuo, C-C, Lee, Duu-Jong
- Authors: Whiteley, Chris G , Shing, C-Y , Kuo, C-C , Lee, Duu-Jong
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67105 , vital:29032 , https://doi.org/10.1016/j.jtice.2015.10.029
- Description: publisher version , This interaction of silver nanoparticles (AgNP) with human immune-deficiency virus aspartic protease (HIVPR) is examined by molecular dynamics simulation using the Colores (Situs) package and biophysical techniques using UV–vis spectroscopy, dynamic light scattering, transmission electron microscopy and circular dichroism. The ‘docking’ of AgNP with HIVPR creates a complex [AgNP–HIVPR] to initiate a hypochromic time-dependent red-shift for the surface plasmon resonance maximum. MD simulations reflect large perturbations to enzyme conformations by fluctuations of both rmsd and B-factors. Increase in changes to electrostatic potentials within the enzyme, especially, with chain B, suggest hydrophobic interactions for the binding of the AgNP. This is supported by changes to mainchain and sidechain dihedrals for many hydrophobic amino acid including Cys95, Trp6 and Trp42. Circular dichroism spectra reveal disappearance of α-helices and β-sheets and increase in random coil first from chain B then chain A. During initial stages of the interactive simulation the enzyme is conformational flexible to accommodate the AgNP, that docks with the enzyme under a cooperative mechanism, until a more stable structure is formed at convergence. There is a decrease in size of the HIVPR–AgNP complex measured by changes to the gyration radius supporting evidence that the AgNP associates, initially, with chain B.
- Full Text: false
- Date Issued: 2016
- Authors: Whiteley, Chris G , Shing, C-Y , Kuo, C-C , Lee, Duu-Jong
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67105 , vital:29032 , https://doi.org/10.1016/j.jtice.2015.10.029
- Description: publisher version , This interaction of silver nanoparticles (AgNP) with human immune-deficiency virus aspartic protease (HIVPR) is examined by molecular dynamics simulation using the Colores (Situs) package and biophysical techniques using UV–vis spectroscopy, dynamic light scattering, transmission electron microscopy and circular dichroism. The ‘docking’ of AgNP with HIVPR creates a complex [AgNP–HIVPR] to initiate a hypochromic time-dependent red-shift for the surface plasmon resonance maximum. MD simulations reflect large perturbations to enzyme conformations by fluctuations of both rmsd and B-factors. Increase in changes to electrostatic potentials within the enzyme, especially, with chain B, suggest hydrophobic interactions for the binding of the AgNP. This is supported by changes to mainchain and sidechain dihedrals for many hydrophobic amino acid including Cys95, Trp6 and Trp42. Circular dichroism spectra reveal disappearance of α-helices and β-sheets and increase in random coil first from chain B then chain A. During initial stages of the interactive simulation the enzyme is conformational flexible to accommodate the AgNP, that docks with the enzyme under a cooperative mechanism, until a more stable structure is formed at convergence. There is a decrease in size of the HIVPR–AgNP complex measured by changes to the gyration radius supporting evidence that the AgNP associates, initially, with chain B.
- Full Text: false
- Date Issued: 2016
Synthesis and singlet oxygen production by a phthalocyanine when embedded in asymmetric polymer membranes
- Mafukidze, Donovan M, Mashazi, Philani N, Nyokong, Tebello
- Authors: Mafukidze, Donovan M , Mashazi, Philani N , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188563 , vital:44765 , xlink:href="https://doi.org/10.1016/j.polymer.2016.10.032"
- Description: 2(3), 9(10), 16(17), 23(24)-Tetrakis-(4-aminophenoxy) phthalocyaninato indium (III) chloride (ClInTAPPc, 3) was first conjugated to two different polymers: polystyrene (PS) and polyacrylonitrile (PAN) to form 3-PS and 3-PAN. The conjugates were cast into the corresponding polymers to form membranes represented as 3-PS-membrane and 3-PAN-membrane, respectively. The prepared membranes were characterized using various techniques including scanning electron microscopy and solid state UV/Vis spectroscopy. Singlet oxygen quantum yields were higher for the 3-PS-membrane at 0.51 compared to 3-PAN-membrane at 0.35. The larger singlet oxygen also applies to 3-PS (0.63) compared to 3-PAN (0.38) when in solution.
- Full Text:
- Date Issued: 2016
- Authors: Mafukidze, Donovan M , Mashazi, Philani N , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188563 , vital:44765 , xlink:href="https://doi.org/10.1016/j.polymer.2016.10.032"
- Description: 2(3), 9(10), 16(17), 23(24)-Tetrakis-(4-aminophenoxy) phthalocyaninato indium (III) chloride (ClInTAPPc, 3) was first conjugated to two different polymers: polystyrene (PS) and polyacrylonitrile (PAN) to form 3-PS and 3-PAN. The conjugates were cast into the corresponding polymers to form membranes represented as 3-PS-membrane and 3-PAN-membrane, respectively. The prepared membranes were characterized using various techniques including scanning electron microscopy and solid state UV/Vis spectroscopy. Singlet oxygen quantum yields were higher for the 3-PS-membrane at 0.51 compared to 3-PAN-membrane at 0.35. The larger singlet oxygen also applies to 3-PS (0.63) compared to 3-PAN (0.38) when in solution.
- Full Text:
- Date Issued: 2016
Nanocomposites of carbon nanomaterials and metallophthalocyanines : applications towards electrocatalysis
- Authors: Nyoni, Stephen
- Date: 2016
- Subjects: Nanocomposites (Materials) , Nanostructured materials , Electrocatalysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4561 , http://hdl.handle.net/10962/d1020846
- Description: Nanohybrid materials have been prepared and examined for their electrocatalytic activity. The nanocomposites have been prepared from carbon nanomaterials (multiwalled carbon nanotubes (MWCNTs) and graphene nanosheets), cadmium selenide quantum dots and metallophthalocyanines (MPcs). The MPcs used in this work are cobalt tetraamino-phthalocyanine (CoTAPc) and tetra (4-(4,6-diaminopyrimidin-2-ylthio) phthalocyaninatocobalt (II)) (CoPyPc). Their activity has also been explored in different forms; polymeric MPcs, iodine doped MPcs and covalently linked MPcs. The premixed drop-dry, sequential drop-dry and electropolymerisation electrode modification techniques were used to prepare nanocomposite catalysts on the glassy carbon electrode (GCE) surface. The sequential drop dry technique for MPc and MWCNTs gave better catalytic responses in terms of limit of detection, catalytic and electron transfer rate constants relative to the premixed. MWCNTs and CdSe-QDs have been used as intercalating agents to reduce restacking of graphene nanosheets during nanocomposite preparation. Voltammetry, chronoamperometry, scanning electrochemical microscopy and electrochemical impedance spectroscopy methods are used for electrochemical characterization modified GCE. X-ray photoelectron spectroscopy, X-ray diffractometry, transmission electron microscopy, scanning electron microscopy, infra-red spectroscopy, Raman spectroscopy were used to explore surface functionalities, morphology and topography of the nanocomposites. Electrocatalytic activity and possible applications of the modified electrodes were tested using oxygen reduction reaction, l-cysteine oxidation and paraquat reduction. Activity of nanocomposites was found superior over individual nanomaterials in these applications.
- Full Text:
- Date Issued: 2016
- Authors: Nyoni, Stephen
- Date: 2016
- Subjects: Nanocomposites (Materials) , Nanostructured materials , Electrocatalysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4561 , http://hdl.handle.net/10962/d1020846
- Description: Nanohybrid materials have been prepared and examined for their electrocatalytic activity. The nanocomposites have been prepared from carbon nanomaterials (multiwalled carbon nanotubes (MWCNTs) and graphene nanosheets), cadmium selenide quantum dots and metallophthalocyanines (MPcs). The MPcs used in this work are cobalt tetraamino-phthalocyanine (CoTAPc) and tetra (4-(4,6-diaminopyrimidin-2-ylthio) phthalocyaninatocobalt (II)) (CoPyPc). Their activity has also been explored in different forms; polymeric MPcs, iodine doped MPcs and covalently linked MPcs. The premixed drop-dry, sequential drop-dry and electropolymerisation electrode modification techniques were used to prepare nanocomposite catalysts on the glassy carbon electrode (GCE) surface. The sequential drop dry technique for MPc and MWCNTs gave better catalytic responses in terms of limit of detection, catalytic and electron transfer rate constants relative to the premixed. MWCNTs and CdSe-QDs have been used as intercalating agents to reduce restacking of graphene nanosheets during nanocomposite preparation. Voltammetry, chronoamperometry, scanning electrochemical microscopy and electrochemical impedance spectroscopy methods are used for electrochemical characterization modified GCE. X-ray photoelectron spectroscopy, X-ray diffractometry, transmission electron microscopy, scanning electron microscopy, infra-red spectroscopy, Raman spectroscopy were used to explore surface functionalities, morphology and topography of the nanocomposites. Electrocatalytic activity and possible applications of the modified electrodes were tested using oxygen reduction reaction, l-cysteine oxidation and paraquat reduction. Activity of nanocomposites was found superior over individual nanomaterials in these applications.
- Full Text:
- Date Issued: 2016
Miscellaneous provisions
- Arendse, Jacqueline A, Clegg, David, Williams, Robert C
- Authors: Arendse, Jacqueline A , Clegg, David , Williams, Robert C
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/131276 , vital:36548 , https://store.lexisnexis.co.za/products/silke-on-tax-administration-skuZASKUPG1440
- Description: Miscellaneous provisions pertaining to tax administration are explained in this chapter.
- Full Text: false
- Date Issued: 2016
- Authors: Arendse, Jacqueline A , Clegg, David , Williams, Robert C
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/131276 , vital:36548 , https://store.lexisnexis.co.za/products/silke-on-tax-administration-skuZASKUPG1440
- Description: Miscellaneous provisions pertaining to tax administration are explained in this chapter.
- Full Text: false
- Date Issued: 2016
An evaluation of sampling and statistical methods for long-term monitoring of subtidal reef fishes : a case study of Tsitsikamma National Park marine protected area
- Authors: Parker, Denham
- Date: 2016
- Subjects: Reef fishes -- South Africa -- Monitoring , Tsitsikamma National Park (South Africa)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5385 , http://hdl.handle.net/10962/d1019991
- Description: Tsitsikamma National Park (TNP) possesses the oldest (established 1954), and one of the largest (350 km2) ‘no-take’ marine protected areas (MPA) in South Africa. A long-term monitoring (LTM) programme to observe the subtidal reef fishes in the TNP MPA was established in 2007. To date, 243 angling replicates have been completed, and a total of 2,751 fish belonging to 41 different species have been caught and released. In an era of unprecedented global biodiversity loss, data that can be used to monitor ecosystems and gauge changes in biodiversity through time are essential. This thesis aims to improve the methodological and statistical processes currently available for LTM of subtidal reef fish by providing an evaluation of the TNP MPA LTM programme. Angling data revealed definitive spatial structuring, in the form of spatial autocorrelation, and a shift in viewing spatial dependency as a statistical obstacle to a source of ecological information created a new avenue of data inference. Species-specific distribution maps identified localized habitat as the main predictor variable for species abundance, emphasizing the need for accurate a priori bathymetric information for subtidal monitoring. ‘Random forest’ analyses confirmed spatial variables are more important than temporal variables in predicting species abundance. The effectiveness of Generalized Linear Mixed Models (GAMMs) to account for spatial autocorrelation was highlighted, and evidence that disregarding spatial dependencies in temporal analyses can produce erroneous results was illustrated in the case of dageraad (Chrysoblephus cristiceps). Correlograms indicated that the current sampling strategy produced spatially redundant data and the sampling unit size (150 m2) could be doubled to optimize sampling. Temporal analyses demonstrated that after 50 years of ‘no take’ protection the TNP MPA ichthyofauna exhibits a high level of stability. Species-specific size structure was also found to be highly stable. Dageraad was the only species to exhibit a definitive temporal trend in their size structure, which was attributed to recruitment variation and the possibility that large individuals may migrate out of the study area. The inadequacy of angling as a method for monitoring a broad spectrum of the fish species was highlighted, particularly due to its selectivity towards large predators. As a result, a new sampling technique known as Stereo Baited Remote Underwater Videos (stereo-BRUVs) was introduced to the LTM programme in 2013. Stereo-BRUVs enabled sampling of 2640 fish belonging to 52 different species, from 57 samples collected in less than two years. A comparison of the sampling methods concluded that, compared to angling, stereo-BRUVs provide a superior technique that can survey a significantly larger proportion of the ichthyofauna with minimal length-selectivity biases. In addition, stereo-BRUVs possess a higher statistical power to detect changes in population abundance. However, a potential bias in the form of ‘hyperstability’ in sites with unusually high fish densities was identified as a possible flaw when using stereo-BRUVs. In an attempt to provide a more rigorous method evaluation, simulation testing was employed to assess the ability of angling and stereo-BRUVs to accurately describe a decreasing population. The advantage of this approach is that the simulated population abundances are known, so that each sampling method can be tested in terms of how well it tracks known abundance trends. The study established that stereo- BRUVs provided more accurate data when describing a distinct population decline of roman (Chrysoblephus laticeps) over 10- and 20-year periods. In addition, spawner-biomass was found to be a more accurate population estimate than relative abundance estimates (CPUE and MaxN) due to the inclusion of population size structure information, highlighting the importance of length-frequency data. The study illustrated that an evaluation framework that utilizes simulation testing has the potential to optimize LTM sampling procedures by addressing a number of methodological questions. This includes developing a procedure that aligns data collected from different sampling methods by applying correction factors, thus ensuring LTM programmes are able to adapt sampling strategies without losing data continuity.
- Full Text:
- Date Issued: 2016
- Authors: Parker, Denham
- Date: 2016
- Subjects: Reef fishes -- South Africa -- Monitoring , Tsitsikamma National Park (South Africa)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5385 , http://hdl.handle.net/10962/d1019991
- Description: Tsitsikamma National Park (TNP) possesses the oldest (established 1954), and one of the largest (350 km2) ‘no-take’ marine protected areas (MPA) in South Africa. A long-term monitoring (LTM) programme to observe the subtidal reef fishes in the TNP MPA was established in 2007. To date, 243 angling replicates have been completed, and a total of 2,751 fish belonging to 41 different species have been caught and released. In an era of unprecedented global biodiversity loss, data that can be used to monitor ecosystems and gauge changes in biodiversity through time are essential. This thesis aims to improve the methodological and statistical processes currently available for LTM of subtidal reef fish by providing an evaluation of the TNP MPA LTM programme. Angling data revealed definitive spatial structuring, in the form of spatial autocorrelation, and a shift in viewing spatial dependency as a statistical obstacle to a source of ecological information created a new avenue of data inference. Species-specific distribution maps identified localized habitat as the main predictor variable for species abundance, emphasizing the need for accurate a priori bathymetric information for subtidal monitoring. ‘Random forest’ analyses confirmed spatial variables are more important than temporal variables in predicting species abundance. The effectiveness of Generalized Linear Mixed Models (GAMMs) to account for spatial autocorrelation was highlighted, and evidence that disregarding spatial dependencies in temporal analyses can produce erroneous results was illustrated in the case of dageraad (Chrysoblephus cristiceps). Correlograms indicated that the current sampling strategy produced spatially redundant data and the sampling unit size (150 m2) could be doubled to optimize sampling. Temporal analyses demonstrated that after 50 years of ‘no take’ protection the TNP MPA ichthyofauna exhibits a high level of stability. Species-specific size structure was also found to be highly stable. Dageraad was the only species to exhibit a definitive temporal trend in their size structure, which was attributed to recruitment variation and the possibility that large individuals may migrate out of the study area. The inadequacy of angling as a method for monitoring a broad spectrum of the fish species was highlighted, particularly due to its selectivity towards large predators. As a result, a new sampling technique known as Stereo Baited Remote Underwater Videos (stereo-BRUVs) was introduced to the LTM programme in 2013. Stereo-BRUVs enabled sampling of 2640 fish belonging to 52 different species, from 57 samples collected in less than two years. A comparison of the sampling methods concluded that, compared to angling, stereo-BRUVs provide a superior technique that can survey a significantly larger proportion of the ichthyofauna with minimal length-selectivity biases. In addition, stereo-BRUVs possess a higher statistical power to detect changes in population abundance. However, a potential bias in the form of ‘hyperstability’ in sites with unusually high fish densities was identified as a possible flaw when using stereo-BRUVs. In an attempt to provide a more rigorous method evaluation, simulation testing was employed to assess the ability of angling and stereo-BRUVs to accurately describe a decreasing population. The advantage of this approach is that the simulated population abundances are known, so that each sampling method can be tested in terms of how well it tracks known abundance trends. The study established that stereo- BRUVs provided more accurate data when describing a distinct population decline of roman (Chrysoblephus laticeps) over 10- and 20-year periods. In addition, spawner-biomass was found to be a more accurate population estimate than relative abundance estimates (CPUE and MaxN) due to the inclusion of population size structure information, highlighting the importance of length-frequency data. The study illustrated that an evaluation framework that utilizes simulation testing has the potential to optimize LTM sampling procedures by addressing a number of methodological questions. This includes developing a procedure that aligns data collected from different sampling methods by applying correction factors, thus ensuring LTM programmes are able to adapt sampling strategies without losing data continuity.
- Full Text:
- Date Issued: 2016
An investigation of the morphological and electrochemical properties of spinel cathode oxide materials used in li-ion batteries
- Authors: Snyders, Charmelle
- Date: 2016
- Subjects: Lithium ion batteries Cathodes
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/12929 , vital:27135
- Description: Li-ion batteries have become the more dominant battery type used in portable electronic devices such as cell phones, computers and more recently their application in full electric vehicles (EV). Li-ion batteries have many advantages over the traditional rechargeable systems (Pb-acid and Ni-MH) such as their higher energy density, low self-discharge, long capacity cycle life and relatively maintenance free. Due to their commercial advantages, a lot of research is done in developing new novel Li-ion electrode materials, improving existing ones and to reduce manufacturing costs in order to make them more cost effective in their applications. This study looked at the cathode material chemistry that has a typical spinel manganese oxide (LiMn2O4) type structure. For comparison the study also considered the influence of doping the phase with various metals such as Al, Mg, Co and Ni that were made as precursors using various carboxylic acids (Citric, Ascorbic, Succinic and Poly-acrylic acid) from a sol-gel process. Traditional batch methods of synthesizing the electrode material is costly and do not necessarily provide optimized electrochemical performance. Alternative continuous less energy intensive methods would help reduce the costs of the preparation of the electrode materials. This study investigated the influence of two synthesis techniques on the materials physical and electrochemical characteristics. These synthesis methods included the use of a typical batch sol-gel method and the continuous spray-drying technique. The spinel materials were prepared and characterized by Powder X-Ray Diffraction (PXRD) to confirm the formation of various phases during the synthesis process. In addition, in-situ PXRD techniques were used to track the phase changes that occurred in the typical batch synthesis process from a sol-gel mixture to the final crystalline spinel oxide. The materials were also characterized by thermal gravimetric analysis (TGA), whereby the materials decomposition mechanisms were observed as the precursor was gradually heated to the final oxide. These synthesized materials prepared under various conditions were then used to build suitable Li-ion coin type of cells, whereby their electrochemical properties were tested by simple capacity tests and electrochemical impedance spectroscopy (EIS). EIS measurements were done on the built cells with the various materials at various charge voltages. TG analysis showed that the materials underwent multiple decomposition steps upon heating for the doped lithium manganese oxides, whereas the undoped oxide showed only a single decomposition step. The results showed that all the materials achieved their weight loss below 400 °C, and that the final spinel oxide had already formed. The in-situ PXRD analysis showed the progression of the phase transitions where certain of the materials changed from a crystalline precursor to an amorphous intermediate phase and then finally to the spinel cathode oxide (Li1.03Mg0.2Mn1.77O4, and LiCo1.09Mn0.91O4). For other materials, the precursor would start as an amorphous phase, and then upon heating, convert into an impure intermediate phase (Mn2O3) before forming the final spinel oxide (Li1.03Mn1.97O4 and LiNi0.5Mn1.5O4). The in-situ study also showed the increases in the materials respective lattice parameters of the crystalline unit cells upon heating and the significant increases in their crystallite sizes when heated above 600 °C. Hence the results implied that a type of sintering of the particles would occur at temperatures above 600 °C, thereby increasing the respective crystallite size. The study showed that the cathode active materials made by the sol-gel spray-drying method would give a material that had a significantly larger surface area and a smaller crystallite size when compared to the materials made by the batch process. The electrochemical analysis showed that there was only a slight increase in the discharge capacities of the cells made with the spray-drying technique when compared to the cells made with the materials from the batch sol-gel technique. Whereas, the EIS study showed that there were distinct differences in the charging behavior of the cells made with the various materials using different synthesis techniques. The EIS results showed that there was a general decrease in the cells charge transfer resistance (Rct) as the charge potential increased regardless of the synthesis method used for the various materials. The results also showed that the lithium-ion diffusion coefficient (DLi) obtained from EIS measurements were in most of the samples higher for the cathode materials that had a larger surface area. This implied that the Li-ion could diffuse at a faster rate through the bulk material. The study concluded that by optimizing the synthesis process in terms of the careful control of the thermal parameters, the Li-ion batteries‟ cathode active material of the manganese spinel type could be optimized and be manufactured by using a continuous flow micro spray process.
- Full Text:
- Date Issued: 2016
- Authors: Snyders, Charmelle
- Date: 2016
- Subjects: Lithium ion batteries Cathodes
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/12929 , vital:27135
- Description: Li-ion batteries have become the more dominant battery type used in portable electronic devices such as cell phones, computers and more recently their application in full electric vehicles (EV). Li-ion batteries have many advantages over the traditional rechargeable systems (Pb-acid and Ni-MH) such as their higher energy density, low self-discharge, long capacity cycle life and relatively maintenance free. Due to their commercial advantages, a lot of research is done in developing new novel Li-ion electrode materials, improving existing ones and to reduce manufacturing costs in order to make them more cost effective in their applications. This study looked at the cathode material chemistry that has a typical spinel manganese oxide (LiMn2O4) type structure. For comparison the study also considered the influence of doping the phase with various metals such as Al, Mg, Co and Ni that were made as precursors using various carboxylic acids (Citric, Ascorbic, Succinic and Poly-acrylic acid) from a sol-gel process. Traditional batch methods of synthesizing the electrode material is costly and do not necessarily provide optimized electrochemical performance. Alternative continuous less energy intensive methods would help reduce the costs of the preparation of the electrode materials. This study investigated the influence of two synthesis techniques on the materials physical and electrochemical characteristics. These synthesis methods included the use of a typical batch sol-gel method and the continuous spray-drying technique. The spinel materials were prepared and characterized by Powder X-Ray Diffraction (PXRD) to confirm the formation of various phases during the synthesis process. In addition, in-situ PXRD techniques were used to track the phase changes that occurred in the typical batch synthesis process from a sol-gel mixture to the final crystalline spinel oxide. The materials were also characterized by thermal gravimetric analysis (TGA), whereby the materials decomposition mechanisms were observed as the precursor was gradually heated to the final oxide. These synthesized materials prepared under various conditions were then used to build suitable Li-ion coin type of cells, whereby their electrochemical properties were tested by simple capacity tests and electrochemical impedance spectroscopy (EIS). EIS measurements were done on the built cells with the various materials at various charge voltages. TG analysis showed that the materials underwent multiple decomposition steps upon heating for the doped lithium manganese oxides, whereas the undoped oxide showed only a single decomposition step. The results showed that all the materials achieved their weight loss below 400 °C, and that the final spinel oxide had already formed. The in-situ PXRD analysis showed the progression of the phase transitions where certain of the materials changed from a crystalline precursor to an amorphous intermediate phase and then finally to the spinel cathode oxide (Li1.03Mg0.2Mn1.77O4, and LiCo1.09Mn0.91O4). For other materials, the precursor would start as an amorphous phase, and then upon heating, convert into an impure intermediate phase (Mn2O3) before forming the final spinel oxide (Li1.03Mn1.97O4 and LiNi0.5Mn1.5O4). The in-situ study also showed the increases in the materials respective lattice parameters of the crystalline unit cells upon heating and the significant increases in their crystallite sizes when heated above 600 °C. Hence the results implied that a type of sintering of the particles would occur at temperatures above 600 °C, thereby increasing the respective crystallite size. The study showed that the cathode active materials made by the sol-gel spray-drying method would give a material that had a significantly larger surface area and a smaller crystallite size when compared to the materials made by the batch process. The electrochemical analysis showed that there was only a slight increase in the discharge capacities of the cells made with the spray-drying technique when compared to the cells made with the materials from the batch sol-gel technique. Whereas, the EIS study showed that there were distinct differences in the charging behavior of the cells made with the various materials using different synthesis techniques. The EIS results showed that there was a general decrease in the cells charge transfer resistance (Rct) as the charge potential increased regardless of the synthesis method used for the various materials. The results also showed that the lithium-ion diffusion coefficient (DLi) obtained from EIS measurements were in most of the samples higher for the cathode materials that had a larger surface area. This implied that the Li-ion could diffuse at a faster rate through the bulk material. The study concluded that by optimizing the synthesis process in terms of the careful control of the thermal parameters, the Li-ion batteries‟ cathode active material of the manganese spinel type could be optimized and be manufactured by using a continuous flow micro spray process.
- Full Text:
- Date Issued: 2016
Heat shock protein inhibitors: success stories
- McAlpine, Shelli R, Edkins, Adrienne L
- Authors: McAlpine, Shelli R , Edkins, Adrienne L
- Date: 2016
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/66359 , vital:28940 , https://doi.org/10.1007/978-3-319-32607-8
- Description: publisher version , Introduction: Medicinal chemistry is both science and art. The science of medicinal chemistry offers mankind one of its best hopes for improving the quality of life. The art of medicinal chemistry continues to challenge its practitioners with the need for both intuition and experience to discover new drugs. Hence sharing the experience of drug research is uniquely beneficial to the field of medicinal chemistry. Drug research requires interdisciplinary team-work at the interface between chemistry, biology and medicine. Therefore, the topic-related series Topics in Medicinal Chemistry covers all relevant aspects of drug research, e.g. pathobiochemistry of diseases, identification and validation of (emerging) drug targets, structural biology, drugability of targets, drug design approaches, chemogenomics, synthetic chemistry including combinatorial methods, bioorganic chemistry, natural compounds, high-throughput screening, pharmacological in vitro and in vivo investigations, drug-receptor interactions on the molecular level, structure-activity relationships, drug absorption, distribution, metabolism, elimination, toxicology and pharmacogenomics. In general, special volumes are edited by well known guest editors. , This work is based on the research supported by the South African Research Chairs Initiative of the Department of Science and Technology and National Research Foundation of South Africa (Grant No 98566), the Cancer Association of South Africa (CANSA), Medical Research Council South Africa (MRC-SA) and Rhodes University. The views expressed are those of the authors and should not be attributed to the DST, NRF, CANSA, MRC-SA or Rhodes University. We apologize if we have inadvertently missed any important contributions to the field.
- Full Text: false
- Date Issued: 2016
- Authors: McAlpine, Shelli R , Edkins, Adrienne L
- Date: 2016
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/66359 , vital:28940 , https://doi.org/10.1007/978-3-319-32607-8
- Description: publisher version , Introduction: Medicinal chemistry is both science and art. The science of medicinal chemistry offers mankind one of its best hopes for improving the quality of life. The art of medicinal chemistry continues to challenge its practitioners with the need for both intuition and experience to discover new drugs. Hence sharing the experience of drug research is uniquely beneficial to the field of medicinal chemistry. Drug research requires interdisciplinary team-work at the interface between chemistry, biology and medicine. Therefore, the topic-related series Topics in Medicinal Chemistry covers all relevant aspects of drug research, e.g. pathobiochemistry of diseases, identification and validation of (emerging) drug targets, structural biology, drugability of targets, drug design approaches, chemogenomics, synthetic chemistry including combinatorial methods, bioorganic chemistry, natural compounds, high-throughput screening, pharmacological in vitro and in vivo investigations, drug-receptor interactions on the molecular level, structure-activity relationships, drug absorption, distribution, metabolism, elimination, toxicology and pharmacogenomics. In general, special volumes are edited by well known guest editors. , This work is based on the research supported by the South African Research Chairs Initiative of the Department of Science and Technology and National Research Foundation of South Africa (Grant No 98566), the Cancer Association of South Africa (CANSA), Medical Research Council South Africa (MRC-SA) and Rhodes University. The views expressed are those of the authors and should not be attributed to the DST, NRF, CANSA, MRC-SA or Rhodes University. We apologize if we have inadvertently missed any important contributions to the field.
- Full Text: false
- Date Issued: 2016
The physical activity and health-related fitness of female students at a South African university
- Authors: Baatjes, Tashrique
- Date: 2016
- Subjects: Physical fitness for women Physical education and training Women college students -- Health and hygiene Health behavior
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/5575 , vital:20909
- Description: Physical inactivity and resultant chronic diseases of lifestyle (CDLs) are becoming a global epidemic as secular modernization and the sedentary lifestyles it brings with it become universal. The importance of physical activity (PA) in reducing morbidity and mortality from CDLs and related conditions has been well established. Since it is generally significant that the onset of many CDLs lies in childhood through to adolescence, preventative strategies should start as early in life as possible. Currently, university students are failing to engage in the levels of PA recommended for better health outcomes over the short and long term. To make matters worse, there is increasing evidence of a decrease in PA during the transitional phase from adolescence to adulthood. This study aimed to determine the physical activity (PA) levels, sedentary behaviour and health-related fitness (HRF) characteristics of female university students. In addition, the participants‘ perceived barriers to PA were investigated. The study was exploratory-descriptive and employed a quantitative research design. Five hundred and thirty-one full-time female students, between the ages of 18 and 46, studying at Nelson Mandela Metropolitan University‘s (NMMU) South, North, Second Avenue and Missionvale campuses participated in the study. The participants (n=531) completed an online survey which determined their PA levels, sedentary behaviours and perceived barriers to PA participation. A health-related fitness (HRF) assessment was also administered to 68 participants who completed the online survey. Their height, weight, and waist and hip circumferences were measured, as well as their cardiovascular fitness (CF). The majority (88 percent) of the participants reported low and minimal levels of PA, and 44 percent were either overweight or obese. The participants had a low-risk waist-to-hip ratio (WHR) (M=0.70). The majority of the population (94 percent) had poor cardiovascular fitness (CF). A high prevalence of sitting time was recorded among the participants: on average 855 minutes (14 hours) on a usual weekday and 720 minutes (12 hours) on a usual weekend day. Students reported the greatest length of sitting time at work/attending lectures/studying. Cross tabulations and Chi2 tests indicated no significant relationships among PA and HRF (BMI, WHR and CF) and sedentary behaviour and HRF. The ANOVA and t-test results for PA, sedentary behaviour and HRF related to various demographic variables, found small (0.19 < d < 0.50) and medium (0.49 < d < 0.80) significant differences by race (d=0.43; d=0.52), home language (d=0.41; d=0.44) and living arrangement (d=0.38; d=0.28). No significant relationship was found to exist between age, year of study and faculty of registration and sedentary behaviour or HRF. The participants listed: Not enough time; too expensive to exercise; and, no friends who can exercise with me as the most important barriers to participation in PA. Academic obligations (3.08 mean) was found to be the most important barrier to PA.
- Full Text:
- Date Issued: 2016
- Authors: Baatjes, Tashrique
- Date: 2016
- Subjects: Physical fitness for women Physical education and training Women college students -- Health and hygiene Health behavior
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/5575 , vital:20909
- Description: Physical inactivity and resultant chronic diseases of lifestyle (CDLs) are becoming a global epidemic as secular modernization and the sedentary lifestyles it brings with it become universal. The importance of physical activity (PA) in reducing morbidity and mortality from CDLs and related conditions has been well established. Since it is generally significant that the onset of many CDLs lies in childhood through to adolescence, preventative strategies should start as early in life as possible. Currently, university students are failing to engage in the levels of PA recommended for better health outcomes over the short and long term. To make matters worse, there is increasing evidence of a decrease in PA during the transitional phase from adolescence to adulthood. This study aimed to determine the physical activity (PA) levels, sedentary behaviour and health-related fitness (HRF) characteristics of female university students. In addition, the participants‘ perceived barriers to PA were investigated. The study was exploratory-descriptive and employed a quantitative research design. Five hundred and thirty-one full-time female students, between the ages of 18 and 46, studying at Nelson Mandela Metropolitan University‘s (NMMU) South, North, Second Avenue and Missionvale campuses participated in the study. The participants (n=531) completed an online survey which determined their PA levels, sedentary behaviours and perceived barriers to PA participation. A health-related fitness (HRF) assessment was also administered to 68 participants who completed the online survey. Their height, weight, and waist and hip circumferences were measured, as well as their cardiovascular fitness (CF). The majority (88 percent) of the participants reported low and minimal levels of PA, and 44 percent were either overweight or obese. The participants had a low-risk waist-to-hip ratio (WHR) (M=0.70). The majority of the population (94 percent) had poor cardiovascular fitness (CF). A high prevalence of sitting time was recorded among the participants: on average 855 minutes (14 hours) on a usual weekday and 720 minutes (12 hours) on a usual weekend day. Students reported the greatest length of sitting time at work/attending lectures/studying. Cross tabulations and Chi2 tests indicated no significant relationships among PA and HRF (BMI, WHR and CF) and sedentary behaviour and HRF. The ANOVA and t-test results for PA, sedentary behaviour and HRF related to various demographic variables, found small (0.19 < d < 0.50) and medium (0.49 < d < 0.80) significant differences by race (d=0.43; d=0.52), home language (d=0.41; d=0.44) and living arrangement (d=0.38; d=0.28). No significant relationship was found to exist between age, year of study and faculty of registration and sedentary behaviour or HRF. The participants listed: Not enough time; too expensive to exercise; and, no friends who can exercise with me as the most important barriers to participation in PA. Academic obligations (3.08 mean) was found to be the most important barrier to PA.
- Full Text:
- Date Issued: 2016
The legal protection of foreign direct investment in the new millennium :a critical assessment with a focus on South Africa and Zimbabwe
- Authors: Chidede, Talkmore
- Date: 2016
- Subjects: Investments, Foreign -- Law and legislation Economic policy
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: http://hdl.handle.net/10353/7919 , vital:30814
- Description: The increasing investment gap and reduction in foreign aid has made several developing countries to turn to foreign investment as a mechanism to circumvent their financial constraints among other things. There is substantial empirical evidence that foreign direct investment enhances economic development, employment creation, national competitiveness and diffusion of technology from foreign firms to local firms and workers of the host states. As a result, this study firstly argues that foreign investment is much needed in South Africa and Zimbabwe to improve economic growth and development, create employment and increase their competitiveness in the global market. However, these benefits do not accrue automatically but the host states need to create an enabling environment to exploit such benefits. The legal protection of foreign investment has become a fundamental issue in both international and national law. Efforts have been and are still being made in law as well as in practice to implement national investment legal regimes which are in line with international norms or standards. This study undertakes a contemporary assessment of the legal protection of foreign investment in South Africa and Zimbabwe with a view of examining their compliance with international minimum norms, standards and/or best practices. More recently, both South Africa and Zimbabwe have crafted and implemented investment laws and related policies which are perceived to be somewhat hostile towards foreign investment. To achieve this, selected investment laws and related policies in both jurisdictions are critically analysed. This study puts forward an argument and recommendations for policy makers in both South Africa and Zimbabwe for strategic refinements of investment laws and related policies such that they become flexible, friendly and certain to foreign investors while at the same time advancing their respective national policies aimed at the economic empowerment of local citizens.
- Full Text:
- Date Issued: 2016
- Authors: Chidede, Talkmore
- Date: 2016
- Subjects: Investments, Foreign -- Law and legislation Economic policy
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: http://hdl.handle.net/10353/7919 , vital:30814
- Description: The increasing investment gap and reduction in foreign aid has made several developing countries to turn to foreign investment as a mechanism to circumvent their financial constraints among other things. There is substantial empirical evidence that foreign direct investment enhances economic development, employment creation, national competitiveness and diffusion of technology from foreign firms to local firms and workers of the host states. As a result, this study firstly argues that foreign investment is much needed in South Africa and Zimbabwe to improve economic growth and development, create employment and increase their competitiveness in the global market. However, these benefits do not accrue automatically but the host states need to create an enabling environment to exploit such benefits. The legal protection of foreign investment has become a fundamental issue in both international and national law. Efforts have been and are still being made in law as well as in practice to implement national investment legal regimes which are in line with international norms or standards. This study undertakes a contemporary assessment of the legal protection of foreign investment in South Africa and Zimbabwe with a view of examining their compliance with international minimum norms, standards and/or best practices. More recently, both South Africa and Zimbabwe have crafted and implemented investment laws and related policies which are perceived to be somewhat hostile towards foreign investment. To achieve this, selected investment laws and related policies in both jurisdictions are critically analysed. This study puts forward an argument and recommendations for policy makers in both South Africa and Zimbabwe for strategic refinements of investment laws and related policies such that they become flexible, friendly and certain to foreign investors while at the same time advancing their respective national policies aimed at the economic empowerment of local citizens.
- Full Text:
- Date Issued: 2016
Accountability mechanisms of locally owned versus non -locally owned NGOs in South Africa
- Authors: Van Zyl, Winston Hyman
- Date: 2016
- Subjects: Non-governmental organizations -- South Africa Economic development -- Social aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/45602 , vital:38917
- Description: This paper reports the results of an exploratory semi-mixed methods study entailing triangulation of qualitative and quantitative data to explore differences in the implementation of accountability mechanisms between locally and non-locally owned non-governmental organisations (NGOs). The study involved NGOs in the Eastern Cape and Kwa-Zulu Natal provinces of South Africa. Comparisons were made between individual as well as grouped (upward, downward and horizontal) accountability mechanisms implemented. Other NGO characteristics such as age, size and donor type were also compared with NGO accountability mechanisms as well as with NGO ownership type (local/non-local). It was found that locally owned NGOs more often claimed to implement downward and horizontal accountability mechanisms and also to implement such mechanisms better than non-local NGOs. As established by means of chi-square tests, the above-mentioned differences were statistically significant. Thereupon, non-local NGOs more often claimed to implement upward accountability mechanisms and to implement such mechanisms better than local NGOs. Nonlocal NGOs were found to be significantly older, bigger and better resourced than local NGOs.Previous research found a correlation between local ownership, downward accountability and aid effectiveness and has also shown that the large majority of NGOs struggle to implement downward accountability mechanisms and focus mostly on upward accountability. Very little research was done on local NGOs. The findings of this paper show that the strategies employed by local NGOs to account downwards could inform the strategies of most non-local NGOs, and thereby improve aid effectiveness. This research suggests that an ideal balance between local and non-local ownership of an NGO exists and if such a balance could be achieved, an NGO would excel in both the facilitation of local ownership and acquisition of resources and thereby optimise aid effectiveness.
- Full Text:
- Date Issued: 2016
- Authors: Van Zyl, Winston Hyman
- Date: 2016
- Subjects: Non-governmental organizations -- South Africa Economic development -- Social aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/45602 , vital:38917
- Description: This paper reports the results of an exploratory semi-mixed methods study entailing triangulation of qualitative and quantitative data to explore differences in the implementation of accountability mechanisms between locally and non-locally owned non-governmental organisations (NGOs). The study involved NGOs in the Eastern Cape and Kwa-Zulu Natal provinces of South Africa. Comparisons were made between individual as well as grouped (upward, downward and horizontal) accountability mechanisms implemented. Other NGO characteristics such as age, size and donor type were also compared with NGO accountability mechanisms as well as with NGO ownership type (local/non-local). It was found that locally owned NGOs more often claimed to implement downward and horizontal accountability mechanisms and also to implement such mechanisms better than non-local NGOs. As established by means of chi-square tests, the above-mentioned differences were statistically significant. Thereupon, non-local NGOs more often claimed to implement upward accountability mechanisms and to implement such mechanisms better than local NGOs. Nonlocal NGOs were found to be significantly older, bigger and better resourced than local NGOs.Previous research found a correlation between local ownership, downward accountability and aid effectiveness and has also shown that the large majority of NGOs struggle to implement downward accountability mechanisms and focus mostly on upward accountability. Very little research was done on local NGOs. The findings of this paper show that the strategies employed by local NGOs to account downwards could inform the strategies of most non-local NGOs, and thereby improve aid effectiveness. This research suggests that an ideal balance between local and non-local ownership of an NGO exists and if such a balance could be achieved, an NGO would excel in both the facilitation of local ownership and acquisition of resources and thereby optimise aid effectiveness.
- Full Text:
- Date Issued: 2016