Biochemical characterisation of Pfj2, a Plasmodium falciparum heat shock protein 40 chaperone potentially involved in protein quality control in the endoplasmic reticulum
- Authors: Afolayan, Omolola Folasade
- Date: 2013
- Subjects: Plasmodium falciparum Endoplasmic reticulum Heat shock proteins Malaria , Mosquito-borne infectious disease
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3883 , http://hdl.handle.net/10962/d1001617
- Description: Plasmodium falciparum is a protozoan parasite that causes a severe form of malaria, a mosquito-borne infectious disease in humans. P. falciparum encodes a number of proteins to facilitate its life-cycle, including a type II heat shock protein 40 (Hsp40), Pfj2. Pfj2 shows a degree of homology to human ERdj5, a resident protein of the endoplasmic reticulum (ER) that promotes protein quality control by facilitating the degradation of misfolded proteins. The overall aim of this study was to further understand the function of Pfj2 in the P. falciparum cell by characterising it biochemically. A bioinformatic analysis of Pfj2 was carried out to enable the identification of a potential ER signal sequence and cleavage site. Furthermore, an analysis of Pfj2 protein sequence was performed to compare domain similarities and identities with typical type II Hsp40s namely, human ERdj5, S. cerevisiae Sis1, human Hsj1a and human DnaJB4. The method used included the insertion of the codon-optimised coding sequence for the processed ER form of Pfj2 into the prokaryotic expression vector, pQE30, to enable overproduction of a histidine-tagged protein. A 62 kDa His₆-Pfj2 was successfully expressed in Escherichia coli and purified using denaturing nickel affinity chromatography. ATPase assays were performed to determine the ability of His₆- Pfj2 to stimulate the chaperone activity of the ER Hsp70, also called immunoglobulin binding protein (BiP). Initial studies were conducted on readily available mammalian His₆-BiP as a control, which was shown to have an intrinsic activity of 12.07±3.92 nmolPi/min/mg. His₆- Pfj2 did not stimulate the ATPase activity of mammalian His₆-BiP, suggesting that it either could not act as a co-chaperone of mammalian His₆-BiP (specificity), or it required a misfolded substrate in the system. Therefore, ongoing studies are addressing the interaction of Pfj2 and misfolded substrates with P. falciparum BiP. The results of these studies will further our understanding of a poorly-studied parasite chaperone that represents a potential drug target for development of novel strategies for the control of a serious human disease
- Full Text:
- Date Issued: 2013
- Authors: Afolayan, Omolola Folasade
- Date: 2013
- Subjects: Plasmodium falciparum Endoplasmic reticulum Heat shock proteins Malaria , Mosquito-borne infectious disease
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3883 , http://hdl.handle.net/10962/d1001617
- Description: Plasmodium falciparum is a protozoan parasite that causes a severe form of malaria, a mosquito-borne infectious disease in humans. P. falciparum encodes a number of proteins to facilitate its life-cycle, including a type II heat shock protein 40 (Hsp40), Pfj2. Pfj2 shows a degree of homology to human ERdj5, a resident protein of the endoplasmic reticulum (ER) that promotes protein quality control by facilitating the degradation of misfolded proteins. The overall aim of this study was to further understand the function of Pfj2 in the P. falciparum cell by characterising it biochemically. A bioinformatic analysis of Pfj2 was carried out to enable the identification of a potential ER signal sequence and cleavage site. Furthermore, an analysis of Pfj2 protein sequence was performed to compare domain similarities and identities with typical type II Hsp40s namely, human ERdj5, S. cerevisiae Sis1, human Hsj1a and human DnaJB4. The method used included the insertion of the codon-optimised coding sequence for the processed ER form of Pfj2 into the prokaryotic expression vector, pQE30, to enable overproduction of a histidine-tagged protein. A 62 kDa His₆-Pfj2 was successfully expressed in Escherichia coli and purified using denaturing nickel affinity chromatography. ATPase assays were performed to determine the ability of His₆- Pfj2 to stimulate the chaperone activity of the ER Hsp70, also called immunoglobulin binding protein (BiP). Initial studies were conducted on readily available mammalian His₆-BiP as a control, which was shown to have an intrinsic activity of 12.07±3.92 nmolPi/min/mg. His₆- Pfj2 did not stimulate the ATPase activity of mammalian His₆-BiP, suggesting that it either could not act as a co-chaperone of mammalian His₆-BiP (specificity), or it required a misfolded substrate in the system. Therefore, ongoing studies are addressing the interaction of Pfj2 and misfolded substrates with P. falciparum BiP. The results of these studies will further our understanding of a poorly-studied parasite chaperone that represents a potential drug target for development of novel strategies for the control of a serious human disease
- Full Text:
- Date Issued: 2013
Polyunsaturated fatty acid metabolism and effects on colon cancer cell biology in vitro.
- Authors: Bulcao, Candice
- Date: 2013
- Subjects: Unsaturated fatty acids , Unsaturated fatty acids in human nutrition , Colon (Anatomy)-- Cancer , Cancer -- Nutritional aspects
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4137 , http://hdl.handle.net/10962/d1016128
- Description: Colon cancer is a leading cause of cancer related deaths worldwide. Lifestyle factors such as diet and exercise have been implicated as important agents in colon cancer development and progression. Epidemiological, in vivo and in vitro studies have found that n-3 polyunsaturated fatty acids (PUFAs) reduce colon carcinoma. The role of n-6 PUFAs remains a controversial topic, with studies indicating both promoting and preventing capabilities published. In order to better understand the effects of PUFAs on colon carcinoma, it is important to have an understanding of how they will be broken down in the body. During this study, in silico metabolism of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and arachidonic acid (AA) predicted the formation of hydroxy-, di-hydroxy- and epoxy-FAs. A gas chromatography-mass spectrometry method was developed and validated for the detection of these PUFAs and their cytochrome P450 (CYP) metabolites. A human liver microsomal system for the in vitro metabolism of EPA, DHA and AA was optimised in terms of microsomal and PUFA concentration. The system resulted in the metabolism of the positive control, lauric acid, to 12-hydroxy-lauric acid but was unable to metabolise the PUFAs of interest. EPA, DHA and AA reduced cell viability in the colon carcinoma cell lines SW480 and SW620 in the micromolar concentration range (25 – 200 μM). The CYP epoxidation metabolite of EPA, 17, 18-epoxyeicosatetraenoic acid (17, 18-EpETE) resulted in a significant reduction in SW480 cell viability relative to the parent compound at lower concentrations (25 and 50 μM). Annexin V apoptosis analysis revealed that EPA and 17, 18- EpETE did not result in apoptosis in SW480 cells at a concentration of 25 μM and over an incubation period of 24 hours. A significant reduction in reactive oxygen species production was seen in SW480 cells after incubation with 25 μM 17, 18-EpETE for 24 hours. EPA and 17, 18-EpETE were implicated in the reduction of colon cancer metastasis since they were able to reduce SW480 migration and anchorage independent cell growth. These results indicate that the dietary intake of EPA, DHA and AA may be beneficial to one’s health due to the negative effects that these PUFAs had on colon carcinoma. Future studies are needed to confirm these benefits and compare the effects of the PUFAs to their CYP-metabolites.
- Full Text:
- Date Issued: 2013
- Authors: Bulcao, Candice
- Date: 2013
- Subjects: Unsaturated fatty acids , Unsaturated fatty acids in human nutrition , Colon (Anatomy)-- Cancer , Cancer -- Nutritional aspects
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4137 , http://hdl.handle.net/10962/d1016128
- Description: Colon cancer is a leading cause of cancer related deaths worldwide. Lifestyle factors such as diet and exercise have been implicated as important agents in colon cancer development and progression. Epidemiological, in vivo and in vitro studies have found that n-3 polyunsaturated fatty acids (PUFAs) reduce colon carcinoma. The role of n-6 PUFAs remains a controversial topic, with studies indicating both promoting and preventing capabilities published. In order to better understand the effects of PUFAs on colon carcinoma, it is important to have an understanding of how they will be broken down in the body. During this study, in silico metabolism of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and arachidonic acid (AA) predicted the formation of hydroxy-, di-hydroxy- and epoxy-FAs. A gas chromatography-mass spectrometry method was developed and validated for the detection of these PUFAs and their cytochrome P450 (CYP) metabolites. A human liver microsomal system for the in vitro metabolism of EPA, DHA and AA was optimised in terms of microsomal and PUFA concentration. The system resulted in the metabolism of the positive control, lauric acid, to 12-hydroxy-lauric acid but was unable to metabolise the PUFAs of interest. EPA, DHA and AA reduced cell viability in the colon carcinoma cell lines SW480 and SW620 in the micromolar concentration range (25 – 200 μM). The CYP epoxidation metabolite of EPA, 17, 18-epoxyeicosatetraenoic acid (17, 18-EpETE) resulted in a significant reduction in SW480 cell viability relative to the parent compound at lower concentrations (25 and 50 μM). Annexin V apoptosis analysis revealed that EPA and 17, 18- EpETE did not result in apoptosis in SW480 cells at a concentration of 25 μM and over an incubation period of 24 hours. A significant reduction in reactive oxygen species production was seen in SW480 cells after incubation with 25 μM 17, 18-EpETE for 24 hours. EPA and 17, 18-EpETE were implicated in the reduction of colon cancer metastasis since they were able to reduce SW480 migration and anchorage independent cell growth. These results indicate that the dietary intake of EPA, DHA and AA may be beneficial to one’s health due to the negative effects that these PUFAs had on colon carcinoma. Future studies are needed to confirm these benefits and compare the effects of the PUFAs to their CYP-metabolites.
- Full Text:
- Date Issued: 2013
Modelling stock return volatility dynamics in selected African markets
- Authors: King, Daniel Jonathan
- Date: 2013
- Subjects: Rate of return -- Africa Stocks -- Prices -- Africa Finance -- Developing countries -- Econometric models
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1051 , http://hdl.handle.net/10962/d1006452
- Description: Stock return volatility has been shown to occasionally exhibit discrete structural shifts. These shifts are particularly evident in the transition from ‘normal’ to crisis periods, and tend to be more pronounced in developing markets. This study aims to establish whether accounting for structural changes in the conditional variance process, through the use of Markov-switching models, improves estimates and forecasts of stock return volatility over those of the more conventional single-state (G)ARCH models, within and across selected African markets for the period 2002-2012. In the univariate portion of the study, the performances of various Markov-switching models are tested against a single-state benchmark model through the use of in-sample goodness-of-fit and predictive ability measures. In the multivariate context, the single-state and Markov-switching models are comparatively assessed according to their usefulness in constructing optimal stock portfolios. It is found that, even after accounting for structural breaks in the conditional variance process, conventional GARCH effects remain important to capturing the heteroscedasticity evident in the data. However, those univariate models which include a GARCH term are shown to perform comparatively poorly when used for forecasting purposes. Additionally, in the multivariate study, the use of Markov-switching variance-covariance estimates improves risk-adjusted portfolio returns when compared to portfolios that are constructed using the more conventional single-state models. While there is evidence that the use of some Markov-switching models can result in better forecasts and higher risk-adjusted returns than those models which include GARCH effects, the inability of the simpler Markov-switching models to fully capture the heteroscedasticity in the data remains problematic.
- Full Text:
- Date Issued: 2013
- Authors: King, Daniel Jonathan
- Date: 2013
- Subjects: Rate of return -- Africa Stocks -- Prices -- Africa Finance -- Developing countries -- Econometric models
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1051 , http://hdl.handle.net/10962/d1006452
- Description: Stock return volatility has been shown to occasionally exhibit discrete structural shifts. These shifts are particularly evident in the transition from ‘normal’ to crisis periods, and tend to be more pronounced in developing markets. This study aims to establish whether accounting for structural changes in the conditional variance process, through the use of Markov-switching models, improves estimates and forecasts of stock return volatility over those of the more conventional single-state (G)ARCH models, within and across selected African markets for the period 2002-2012. In the univariate portion of the study, the performances of various Markov-switching models are tested against a single-state benchmark model through the use of in-sample goodness-of-fit and predictive ability measures. In the multivariate context, the single-state and Markov-switching models are comparatively assessed according to their usefulness in constructing optimal stock portfolios. It is found that, even after accounting for structural breaks in the conditional variance process, conventional GARCH effects remain important to capturing the heteroscedasticity evident in the data. However, those univariate models which include a GARCH term are shown to perform comparatively poorly when used for forecasting purposes. Additionally, in the multivariate study, the use of Markov-switching variance-covariance estimates improves risk-adjusted portfolio returns when compared to portfolios that are constructed using the more conventional single-state models. While there is evidence that the use of some Markov-switching models can result in better forecasts and higher risk-adjusted returns than those models which include GARCH effects, the inability of the simpler Markov-switching models to fully capture the heteroscedasticity in the data remains problematic.
- Full Text:
- Date Issued: 2013
The use of tax incentive measure in conjunction with carbon taxes to reduce greenhouse gas emissions and achieve economic growth: a comparative study with lessons for South Africa
- Authors: Poole, Richard
- Date: 2013
- Subjects: Elasticity (Economics) , Substitution (Economics) , Carbon taxes , Carbon taxes -- South Africa , Greenhouse gas mitigation , Greenhouse gas mitigation--South Africa , United Nations Framework Convention on Climate Change -- (1992). Protocols, etc. -- 1997 Dec. 11 , Kyoto Protocol , Substitution elasticity
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:875 , http://hdl.handle.net/10962/d1001607 , Elasticity (Economics) , Substitution (Economics) , Carbon taxes , Carbon taxes -- South Africa , Greenhouse gas mitigation , Greenhouse gas mitigation--South Africa , United Nations Framework Convention on Climate Change -- (1992). Protocols, etc. -- 1997 Dec. 11
- Description: In 1997 industrialized nations, the Third Conference of the Parties to the United Nations Framework Convention on Climate Change, met in Kyoto, Japan to sign a treaty (the “Kyoto Protocol”) in terms of which industrialized nations would be required to reduce their greenhouse gas emission by at least five percent below 1990 levels by the end of the “first commitment period” 2008-2012. South Africa is not regarded as an industrialized nation, but nonetheless acceded to the Kyoto Protocol in 2002. The literature reviewed in the present research reveals that, although idealistic, the Kyoto Protocol has been problematic. Fourteen meetings of the Conference of Parties to the Kyoto Protocol between 1997 and 2011 have achieved little more than to repeatedly defer and redefine Kyoto obligations. This research was undertaken to document the existing environmental taxation policies employed in selected international jurisdictions with a view to providing a framework for environmental tax policy formation in South Africa to assist this country in meeting its “greenhouse gas” emission targets, while at the same time promoting economic growth. A doctrinal research methodology was adopted in this study as it mainly analysed and interpreted legislation and policy documents and therefore the approach was qualitative in nature. An extensive literature survey was performed to document the various environmental policies that have been legislated in the selected jurisdictions. Comparisons were drawn with proposed tax policy measures for South Africa. The literature indicates that in the selected international jurisdictions carbon taxes achieved less-than-optimal results, largely due to political and industry-competitive agendas. With South Africa planning to introduce a carbon tax, it is submitted that the implementation of a carbon tax regime in isolation will be counter-productive, given South Africa’s economic profile. On the basis of the literature reviewed, it was concluded that South Africa should consider “recycling” carbon tax revenues within the economy to fund a broad-based tax incentive regime that will stimulate the change to non-carbon energy whilst promoting growth through sustainable development
- Full Text:
- Date Issued: 2013
- Authors: Poole, Richard
- Date: 2013
- Subjects: Elasticity (Economics) , Substitution (Economics) , Carbon taxes , Carbon taxes -- South Africa , Greenhouse gas mitigation , Greenhouse gas mitigation--South Africa , United Nations Framework Convention on Climate Change -- (1992). Protocols, etc. -- 1997 Dec. 11 , Kyoto Protocol , Substitution elasticity
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:875 , http://hdl.handle.net/10962/d1001607 , Elasticity (Economics) , Substitution (Economics) , Carbon taxes , Carbon taxes -- South Africa , Greenhouse gas mitigation , Greenhouse gas mitigation--South Africa , United Nations Framework Convention on Climate Change -- (1992). Protocols, etc. -- 1997 Dec. 11
- Description: In 1997 industrialized nations, the Third Conference of the Parties to the United Nations Framework Convention on Climate Change, met in Kyoto, Japan to sign a treaty (the “Kyoto Protocol”) in terms of which industrialized nations would be required to reduce their greenhouse gas emission by at least five percent below 1990 levels by the end of the “first commitment period” 2008-2012. South Africa is not regarded as an industrialized nation, but nonetheless acceded to the Kyoto Protocol in 2002. The literature reviewed in the present research reveals that, although idealistic, the Kyoto Protocol has been problematic. Fourteen meetings of the Conference of Parties to the Kyoto Protocol between 1997 and 2011 have achieved little more than to repeatedly defer and redefine Kyoto obligations. This research was undertaken to document the existing environmental taxation policies employed in selected international jurisdictions with a view to providing a framework for environmental tax policy formation in South Africa to assist this country in meeting its “greenhouse gas” emission targets, while at the same time promoting economic growth. A doctrinal research methodology was adopted in this study as it mainly analysed and interpreted legislation and policy documents and therefore the approach was qualitative in nature. An extensive literature survey was performed to document the various environmental policies that have been legislated in the selected jurisdictions. Comparisons were drawn with proposed tax policy measures for South Africa. The literature indicates that in the selected international jurisdictions carbon taxes achieved less-than-optimal results, largely due to political and industry-competitive agendas. With South Africa planning to introduce a carbon tax, it is submitted that the implementation of a carbon tax regime in isolation will be counter-productive, given South Africa’s economic profile. On the basis of the literature reviewed, it was concluded that South Africa should consider “recycling” carbon tax revenues within the economy to fund a broad-based tax incentive regime that will stimulate the change to non-carbon energy whilst promoting growth through sustainable development
- Full Text:
- Date Issued: 2013
The influence of individual employee performance metrics on a sub-culture in a professional services firm in Durban, South Africa
- Authors: Zvarevashe, Marshall
- Date: 2013
- Subjects: Performance -- Evaluation Corporate culture -- South Africa Organizational effectiveness Leadership Management -- South Africa Organizational behavior -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:714 , http://hdl.handle.net/10962/d1001868
- Description: In today’s fast paced and global economy, competitive advantage is increasingly focused more on organisational behaviours rather than on the traditional tenets of land, labour and capital. Going beyond the traditional, organisations that are best able to get the most and the best out of their people are the ones most likely to perform better. This study aims to build an understanding of how culture is influenced by individual employee performance metrics that are used in an organisation. Previous research has been done in the broad fields of organisational culture and employee performance metrics separately, but no studies were identified in literature that focused on the interaction of the two concepts specifically. Therefore, this study seeks to answer the following research question: How do individual employee performance metrics influence sub-culture in the context of a professional services firm in Durban? This study predominantly focused not on performance at the organisational level, but rather the more granular level of individual employee performance metrics and sub-culture in one of the divisions of a professional services firm. This qualitative study explores the multiple perspectives of reality of ten of the 32 managers in the Advisory division of a professional services organisation, regarding how individual employee performance metrics influence their world view of work, or the way they perceive, think, feel and interact in the world of work. The focus of the study was limited to one department, in one branch of a multinational organisation and focused only on the horizontal layer of the “manager group” within the staff levels. Semi-structured, in-depth and face-to-face interviews were conducted with these managers as a means of gathering and saturating data. Interviewees were identified using a stratified sampling from the group of managers in the Advisory division. Open coding and constant comparison was used to analyse data. Page ii of viii The results of the study show that managers had very varied and complex perceptions of how the individual performance metrics used to assess their performance influence the sub-culture of their world of work. The key findings manifested that misuse and abuse of performance metrics by leaders, leadership bias in respect to recognition, reward and remunerations, the predominant focus of the division on the bottom line and emphasis on success at all cost, and low employee morale were all aspects of performance that impacted on how employees behaved in the division. The effect of these factors on the managers operating in this division was that there were low levels of employee commitment which were experienced through low morale and reduced productivity; managers felt that there was a restriction in the development of their careers, all of which resulted in a disregard to values of the organisation. This study reflects how the reward and recognition system using the balanced scorecard has shifted the focus of the department away from the organisation’s espoused values. This has resulted in various leadership and management questions for the leadership of the division in this study. This research also adds to existing literature that links performance and culture within the organisational context that it goes beyond the prevalent themes in literature which focus on performance at the organisation level. This study focuses on performance at the employee level and in particular in a professional services firm in South Africa. The study has three interrelated sections which are however considered as standalone. The first section is an evaluation report based on the Advisory division of a professional services firm in Durban, South Africa, and consists of a literature review, the methodology followed in conducting the study, results and the discussion thereof. The report also highlights limitations of the study, recommendations and the perceived value of the study. The report ends with a summary in the form of a conclusion. Section 2 comprises a more comprehensive literature review while Section 3 documents the research methodology followed in the study.
- Full Text:
- Date Issued: 2013
- Authors: Zvarevashe, Marshall
- Date: 2013
- Subjects: Performance -- Evaluation Corporate culture -- South Africa Organizational effectiveness Leadership Management -- South Africa Organizational behavior -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:714 , http://hdl.handle.net/10962/d1001868
- Description: In today’s fast paced and global economy, competitive advantage is increasingly focused more on organisational behaviours rather than on the traditional tenets of land, labour and capital. Going beyond the traditional, organisations that are best able to get the most and the best out of their people are the ones most likely to perform better. This study aims to build an understanding of how culture is influenced by individual employee performance metrics that are used in an organisation. Previous research has been done in the broad fields of organisational culture and employee performance metrics separately, but no studies were identified in literature that focused on the interaction of the two concepts specifically. Therefore, this study seeks to answer the following research question: How do individual employee performance metrics influence sub-culture in the context of a professional services firm in Durban? This study predominantly focused not on performance at the organisational level, but rather the more granular level of individual employee performance metrics and sub-culture in one of the divisions of a professional services firm. This qualitative study explores the multiple perspectives of reality of ten of the 32 managers in the Advisory division of a professional services organisation, regarding how individual employee performance metrics influence their world view of work, or the way they perceive, think, feel and interact in the world of work. The focus of the study was limited to one department, in one branch of a multinational organisation and focused only on the horizontal layer of the “manager group” within the staff levels. Semi-structured, in-depth and face-to-face interviews were conducted with these managers as a means of gathering and saturating data. Interviewees were identified using a stratified sampling from the group of managers in the Advisory division. Open coding and constant comparison was used to analyse data. Page ii of viii The results of the study show that managers had very varied and complex perceptions of how the individual performance metrics used to assess their performance influence the sub-culture of their world of work. The key findings manifested that misuse and abuse of performance metrics by leaders, leadership bias in respect to recognition, reward and remunerations, the predominant focus of the division on the bottom line and emphasis on success at all cost, and low employee morale were all aspects of performance that impacted on how employees behaved in the division. The effect of these factors on the managers operating in this division was that there were low levels of employee commitment which were experienced through low morale and reduced productivity; managers felt that there was a restriction in the development of their careers, all of which resulted in a disregard to values of the organisation. This study reflects how the reward and recognition system using the balanced scorecard has shifted the focus of the department away from the organisation’s espoused values. This has resulted in various leadership and management questions for the leadership of the division in this study. This research also adds to existing literature that links performance and culture within the organisational context that it goes beyond the prevalent themes in literature which focus on performance at the organisation level. This study focuses on performance at the employee level and in particular in a professional services firm in South Africa. The study has three interrelated sections which are however considered as standalone. The first section is an evaluation report based on the Advisory division of a professional services firm in Durban, South Africa, and consists of a literature review, the methodology followed in conducting the study, results and the discussion thereof. The report also highlights limitations of the study, recommendations and the perceived value of the study. The report ends with a summary in the form of a conclusion. Section 2 comprises a more comprehensive literature review while Section 3 documents the research methodology followed in the study.
- Full Text:
- Date Issued: 2013
'Leaders like children playing with a grenade?' : an analysis of how the Arab Spring was received in South Africa
- Authors: Gevers, Tristan Ronald
- Date: 2013
- Subjects: Arab Spring, 2010- Revolutions -- Theory Arab countries -- Social conditions -- 21st century South Africa -- Social condtions -- 21st century
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2846 , http://hdl.handle.net/10962/d1006031
- Description: When the Arab Spring took place, it took the world by surprise and sparked renewed interest in the idea of revolution. With differing opinions on what caused such a revolutionary wave throughout the North African and Middle Eastern region, many began looking at their own countries, and South Africa was no different. A debate was sparked in South Africa, as to whether there would be a revolution or not. What I originally set out to accomplish is to find out which side of the debate would be correct through the philosophical context of revolutionary theory. Initially, we attempted to define and consider the history of revolutionary theory. We found that revolutionary theory has gone through four generation and that even finding a theoretically informed definition is difficult. Following this, we considered some social-psychological theories of revolution as well as theories of moral indignation. We found that these theories were incredibly informative and that they provide some insight into the reasoning for revolutionary fear in the South African debate. Through the use of opinion pieces, we then considered the South African debate, and – using socialpsychological theories and the theories of moral indignation - found that both sides of the argument had valuable points, however, they often lacked some foresight. With tentative agreement, we found that the side arguing that there would a revolution in South Africa had a more valuable argument, despite its limitations. However, far more research is required before one can – with more accuracy – predict a revolutionary occurrence in such a way as was done in South Africa.
- Full Text:
- Date Issued: 2013
- Authors: Gevers, Tristan Ronald
- Date: 2013
- Subjects: Arab Spring, 2010- Revolutions -- Theory Arab countries -- Social conditions -- 21st century South Africa -- Social condtions -- 21st century
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2846 , http://hdl.handle.net/10962/d1006031
- Description: When the Arab Spring took place, it took the world by surprise and sparked renewed interest in the idea of revolution. With differing opinions on what caused such a revolutionary wave throughout the North African and Middle Eastern region, many began looking at their own countries, and South Africa was no different. A debate was sparked in South Africa, as to whether there would be a revolution or not. What I originally set out to accomplish is to find out which side of the debate would be correct through the philosophical context of revolutionary theory. Initially, we attempted to define and consider the history of revolutionary theory. We found that revolutionary theory has gone through four generation and that even finding a theoretically informed definition is difficult. Following this, we considered some social-psychological theories of revolution as well as theories of moral indignation. We found that these theories were incredibly informative and that they provide some insight into the reasoning for revolutionary fear in the South African debate. Through the use of opinion pieces, we then considered the South African debate, and – using socialpsychological theories and the theories of moral indignation - found that both sides of the argument had valuable points, however, they often lacked some foresight. With tentative agreement, we found that the side arguing that there would a revolution in South Africa had a more valuable argument, despite its limitations. However, far more research is required before one can – with more accuracy – predict a revolutionary occurrence in such a way as was done in South Africa.
- Full Text:
- Date Issued: 2013
Exploring the correlation between language medium and academic achievement: a comparative study of the language of learning and teaching (LoLT) and mathematics results in the 2010 Grade 12 National Senior Certificate examinations in the Eastern Cape
- Mbude-Shale, Beryl Ntombizanele
- Authors: Mbude-Shale, Beryl Ntombizanele
- Date: 2013
- Subjects: Academic achievement -- Research -- South Africa -- Eastern Cape Language and education -- Research -- South Africa -- Eastern Cape Language policy -- South Africa -- Eastern Cape Mathematics -- Study and teaching (Elementary) -- South Africa -- Eastern Cape Education, Secondary -- South Africa -- Eastern Cape Matric Learners Language planning Mathematics Policies Academic performance Mother-tongue
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:3559 , http://hdl.handle.net/10962/d1001863
- Description: In 2009, of the 68,129 learners who wrote Matric, only 34,731 learners passed. In 2010, there was an increase in the provincial pass rate causing much excitement across the board. The reality was that of the 64,090 learners who wrote, only 37,345 learners passed. In 2010, a result below 50% was recorded for Mathematics and Physical Science nationally (DBE; 2011). Despite efforts by the Education Department to support MSTE; establishing Mathematics and Science schools, NGOs and HEIs giving extra Mathematics and Science support to students and teachers, the offering of Saturday classes and incubation camps, we still get minimal return on investment. This thesis analyses these results against the backdrop of language planning theory, particularly language-in-education policies, pre and post-apartheid. The correlation between language medium and academic performance in language (LoLT) and Mathematics of Grade 12 learners is explored. Worldwide the issue of low achievement in Mathematics by ESL students is of great concern (Cuevas, 1984). The 2004 Systemic Evaluation sample of learners was in Grade 6 then; in 2010 they wrote Grade 12. The purpose of the systemic evaluation was to provide an insight into the levels of learner performance in Maths, Natural Science and LoLT in Grade 6 (IPSER, 2006). A major finding of the IPSER was that language was an important factor related to learner achievement. A major disparity was observed in this research, that although the Eastern Cape performed below the national average in the three subjects evaluated, the learners for whom LoLT was the same as their home language obtained scores that were significantly higher than those whose home language was different from the LoLT. The provincial average for Mathematics was 23.40% compared to the national average of 27.80%. For LoLT the province scored 30.16 against the national score of 38.03%. Of interest in this study is a juxtaposition of the Matric results of this same group of learners in 2010 and see whether issues that came up then are still significant in mitigating achievement in Mathematics and Language (LoLT). Some research studies have been conducted in South Africa (Adler, 1998; Setati, 1996-2002; Moloi, 2006) identifying the vital role language plays in learning Mathematics, especially for English L2 learners. Building on research and findings of academics such as the late Alexander, Ramani, Joseph, Hendricks, Heugh, Dalvit, Webb and Murray, this thesis suggests that a mother-tongue-based-bilingual approach to education should be adopted as a matter of urgency
- Full Text:
- Date Issued: 2013
- Authors: Mbude-Shale, Beryl Ntombizanele
- Date: 2013
- Subjects: Academic achievement -- Research -- South Africa -- Eastern Cape Language and education -- Research -- South Africa -- Eastern Cape Language policy -- South Africa -- Eastern Cape Mathematics -- Study and teaching (Elementary) -- South Africa -- Eastern Cape Education, Secondary -- South Africa -- Eastern Cape Matric Learners Language planning Mathematics Policies Academic performance Mother-tongue
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:3559 , http://hdl.handle.net/10962/d1001863
- Description: In 2009, of the 68,129 learners who wrote Matric, only 34,731 learners passed. In 2010, there was an increase in the provincial pass rate causing much excitement across the board. The reality was that of the 64,090 learners who wrote, only 37,345 learners passed. In 2010, a result below 50% was recorded for Mathematics and Physical Science nationally (DBE; 2011). Despite efforts by the Education Department to support MSTE; establishing Mathematics and Science schools, NGOs and HEIs giving extra Mathematics and Science support to students and teachers, the offering of Saturday classes and incubation camps, we still get minimal return on investment. This thesis analyses these results against the backdrop of language planning theory, particularly language-in-education policies, pre and post-apartheid. The correlation between language medium and academic performance in language (LoLT) and Mathematics of Grade 12 learners is explored. Worldwide the issue of low achievement in Mathematics by ESL students is of great concern (Cuevas, 1984). The 2004 Systemic Evaluation sample of learners was in Grade 6 then; in 2010 they wrote Grade 12. The purpose of the systemic evaluation was to provide an insight into the levels of learner performance in Maths, Natural Science and LoLT in Grade 6 (IPSER, 2006). A major finding of the IPSER was that language was an important factor related to learner achievement. A major disparity was observed in this research, that although the Eastern Cape performed below the national average in the three subjects evaluated, the learners for whom LoLT was the same as their home language obtained scores that were significantly higher than those whose home language was different from the LoLT. The provincial average for Mathematics was 23.40% compared to the national average of 27.80%. For LoLT the province scored 30.16 against the national score of 38.03%. Of interest in this study is a juxtaposition of the Matric results of this same group of learners in 2010 and see whether issues that came up then are still significant in mitigating achievement in Mathematics and Language (LoLT). Some research studies have been conducted in South Africa (Adler, 1998; Setati, 1996-2002; Moloi, 2006) identifying the vital role language plays in learning Mathematics, especially for English L2 learners. Building on research and findings of academics such as the late Alexander, Ramani, Joseph, Hendricks, Heugh, Dalvit, Webb and Murray, this thesis suggests that a mother-tongue-based-bilingual approach to education should be adopted as a matter of urgency
- Full Text:
- Date Issued: 2013
A standardised protocol for roadkill detection and the determinants of roadkill in the greater Mapungubwe Transfrontier Conservation Area, Limpopo Province, South Africa
- Authors: Collinson, Wendy Jane
- Date: 2013
- Subjects: Roadkill -- South Africa -- Mapungubwe Site , Traffic safety and wildlife -- South Africa -- Mapungubwe Site
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5606 , http://hdl.handle.net/10962/d1002056 , Roadkill -- South Africa -- Mapungubwe Site , Traffic safety and wildlife -- South Africa -- Mapungubwe Site
- Description: Despite evidence suggesting that road traffic is a major threat to biodiversity loss, very little is known about its actual impact on wildlife populations in South Africa. Globally, road density and traffic volumes are increasing, and although huge budgets are devoted to the construction and upgrading of roads, there is little or no allocation to mitigation measures for protecting fauna in most countries, particularly Africa. Further, no global standardised protocol exists for the rapid assessment of roadkill or the most economical and efficient approach for assessing roadkill rates. Using vehicle field trials, the reliability of detecting artificially deployed roadkill was assessed. Roadkill detection rates decreased significantly at speeds >50 km/h and were also significantly influenced by light conditions (i.e. detection success was greater when the sun was high) and the position of the roadkill on the road (i.e. smaller roadkill on verges were often missed). These results suggest that roadkill sampling was most effective between 1.5 hours after dawn and 1.5 hours before dusk and that driving at slower speeds (<50 km.h⁻ₑ) was required to detect roadkill. This protocol was implemented across three ecological seasons on a 100 km paved road and a 20 km unpaved road in the Greater Mapungubwe Transfrontier Conservation Area, Limpopo Province, South Africa. Driven daily over a 120-day period (three periods consisting each of 40 days), a total of 1,027 roadkill were recorded. These comprised 162 species from all terrestrial vertebrate groups with birds being the most commonly encountered roadkill (50% of all incidents). The high numbers of vertebrates identified as roadkill suggests that road traffic could have potentially unsustainable impacts on wildlife populations and hence the biodiversity of the area. Seventeen variables were identified as possible determinants of roadkill occurrence with season, rainfall, minimum and maximum temperature, habitat type, grass height, grass density, fence type and vehicle type significantly influencing roadkill numbers. Significantly more roadkill were detected on the paved road (9.91/100km) than on the unpaved road (1.8/100km) probably because of greater traffic volumes and the increased speed that vehicles travelled on the paved road. Warmer temperatures and increased rainfall in the preceding 24 hours also increased road mortality numbers as animals tended to become more active during these times. Interestingly, more roadkill was detected in open roadside habitats compared to dense roadside habitats on both the paved and unpaved roads and when grass on the roadside verge was of intermediate height. Open habitat possibly may provide a natural corridor for wildlife which ultimately end up on the road. Roadkill numbers increased when certain other physical barriers, such as cattle fences, were present, probably because these barriers were more penetrable than electric fencing. A series of mitigation measures are proposed to reduce the impacts of roads on wildlife in South Africa. These mitigation measures highlight the need to address the balance between the development of a country’s transport infrastructure and the conservation of its fauna. It is important that research on the impacts of roads becomes standardised to enable robust statistical comparisons which will provide a greater understanding of the potential threats to vertebrate biodiversity
- Full Text:
- Date Issued: 2013
- Authors: Collinson, Wendy Jane
- Date: 2013
- Subjects: Roadkill -- South Africa -- Mapungubwe Site , Traffic safety and wildlife -- South Africa -- Mapungubwe Site
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5606 , http://hdl.handle.net/10962/d1002056 , Roadkill -- South Africa -- Mapungubwe Site , Traffic safety and wildlife -- South Africa -- Mapungubwe Site
- Description: Despite evidence suggesting that road traffic is a major threat to biodiversity loss, very little is known about its actual impact on wildlife populations in South Africa. Globally, road density and traffic volumes are increasing, and although huge budgets are devoted to the construction and upgrading of roads, there is little or no allocation to mitigation measures for protecting fauna in most countries, particularly Africa. Further, no global standardised protocol exists for the rapid assessment of roadkill or the most economical and efficient approach for assessing roadkill rates. Using vehicle field trials, the reliability of detecting artificially deployed roadkill was assessed. Roadkill detection rates decreased significantly at speeds >50 km/h and were also significantly influenced by light conditions (i.e. detection success was greater when the sun was high) and the position of the roadkill on the road (i.e. smaller roadkill on verges were often missed). These results suggest that roadkill sampling was most effective between 1.5 hours after dawn and 1.5 hours before dusk and that driving at slower speeds (<50 km.h⁻ₑ) was required to detect roadkill. This protocol was implemented across three ecological seasons on a 100 km paved road and a 20 km unpaved road in the Greater Mapungubwe Transfrontier Conservation Area, Limpopo Province, South Africa. Driven daily over a 120-day period (three periods consisting each of 40 days), a total of 1,027 roadkill were recorded. These comprised 162 species from all terrestrial vertebrate groups with birds being the most commonly encountered roadkill (50% of all incidents). The high numbers of vertebrates identified as roadkill suggests that road traffic could have potentially unsustainable impacts on wildlife populations and hence the biodiversity of the area. Seventeen variables were identified as possible determinants of roadkill occurrence with season, rainfall, minimum and maximum temperature, habitat type, grass height, grass density, fence type and vehicle type significantly influencing roadkill numbers. Significantly more roadkill were detected on the paved road (9.91/100km) than on the unpaved road (1.8/100km) probably because of greater traffic volumes and the increased speed that vehicles travelled on the paved road. Warmer temperatures and increased rainfall in the preceding 24 hours also increased road mortality numbers as animals tended to become more active during these times. Interestingly, more roadkill was detected in open roadside habitats compared to dense roadside habitats on both the paved and unpaved roads and when grass on the roadside verge was of intermediate height. Open habitat possibly may provide a natural corridor for wildlife which ultimately end up on the road. Roadkill numbers increased when certain other physical barriers, such as cattle fences, were present, probably because these barriers were more penetrable than electric fencing. A series of mitigation measures are proposed to reduce the impacts of roads on wildlife in South Africa. These mitigation measures highlight the need to address the balance between the development of a country’s transport infrastructure and the conservation of its fauna. It is important that research on the impacts of roads becomes standardised to enable robust statistical comparisons which will provide a greater understanding of the potential threats to vertebrate biodiversity
- Full Text:
- Date Issued: 2013
A systematic study of Berkheya and allies (Compositae)
- Authors: Phaliso, Ntombifikile
- Date: 2013
- Subjects: Compositae -- Africa, Southern , Daisies -- Africa, Southern , Compositae -- Phylogeny -- Africa, Southern , Compositae -- Geographical distribution -- Africa, Southern , Compositae -- Classification -- Africa, Southern , Cladistic analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4179 , http://hdl.handle.net/10962/d1003054
- Description: Berkheya Ehrh. is a genus of daisies in the tribe Arctotideae, subtribe Gorteriinae with over 80 species, most of which occur in southern Africa. This genus has centres of diversity associated with the montane regions of South Africa, including the Drakensberg Alpine Centre and Mpumalanga escarpment regions. Previous molecular and morphological studies indicate that Berkheya is paraphyletic. I present phylogenies based on nrDNA (ITS; Internal Transcribed Spacer) and cpDNA (psbA-trnH) sequence data analysed with Bayesian Inference and Parsimony. A phylogeny of combined cp- and nrDNA is also presented. These phylogenies are used to assess generic limits and to investigate the biogeographic patterns of Berkheya and its allies. The ITS phylogeny shows five well supported clades of Berkheya, two of which (Clades I and 2) are monophyletic summer rainfall region clades. Clades 3 to 5 are all paraphyletic winter rainfall clades with Cullumia occurring in the third clade, Cuspida occurring in the fourth and Didelta in Clade 5. Both psbA-trnH and combined phylogenies show concordance with the clade distribution shown in the ITS phylogeny. The ITS phylogeny was used to analyse correspondence with Roessler’s (1959) Series. It was found that the phylogeny showed considerable agreement with Roessler’s series, but B. bipinnatifida and B. spinosa of Series Speciosae may require some revision as well as taxa of monotypic series Cruciatae and Angustae. It is suggested that the latter series be merged with Cullumia species to form a single series. Some consideration should be taken to include Didelta species into Series Fruticosae as Didelta occurs in subclade 5b of Clade 5 with other Series Fruticosae taxa. Achene morphology was examined from species from each of the five clades to investigate the relationships of Berkheya and its allies, as well as to determine if there were any consistent achene features for each clade. The structure of surface cells on the fruit, the presence, absence and morphology of twin hairs as well as the structure of the pappus scales were found to be most useful in reflecting phylogenetic relationships within the clades. When compared with the clades of the ITS phylogeny, achene morphology showed consistent characters between taxa occurring in the same clades. As the most comprehensive study involving Berkheya, this phylogenenetic investigation was able to confirm that Berkheya is a paraphyletic genus with Didelta, Cullumia and Cuspida needing to be subsumed into Berkheya. An alternative classification is that taxa of Clade 5 could possibly be erected as an expanded Didelta, separate and sister to Berkheya.
- Full Text:
- Date Issued: 2013
- Authors: Phaliso, Ntombifikile
- Date: 2013
- Subjects: Compositae -- Africa, Southern , Daisies -- Africa, Southern , Compositae -- Phylogeny -- Africa, Southern , Compositae -- Geographical distribution -- Africa, Southern , Compositae -- Classification -- Africa, Southern , Cladistic analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4179 , http://hdl.handle.net/10962/d1003054
- Description: Berkheya Ehrh. is a genus of daisies in the tribe Arctotideae, subtribe Gorteriinae with over 80 species, most of which occur in southern Africa. This genus has centres of diversity associated with the montane regions of South Africa, including the Drakensberg Alpine Centre and Mpumalanga escarpment regions. Previous molecular and morphological studies indicate that Berkheya is paraphyletic. I present phylogenies based on nrDNA (ITS; Internal Transcribed Spacer) and cpDNA (psbA-trnH) sequence data analysed with Bayesian Inference and Parsimony. A phylogeny of combined cp- and nrDNA is also presented. These phylogenies are used to assess generic limits and to investigate the biogeographic patterns of Berkheya and its allies. The ITS phylogeny shows five well supported clades of Berkheya, two of which (Clades I and 2) are monophyletic summer rainfall region clades. Clades 3 to 5 are all paraphyletic winter rainfall clades with Cullumia occurring in the third clade, Cuspida occurring in the fourth and Didelta in Clade 5. Both psbA-trnH and combined phylogenies show concordance with the clade distribution shown in the ITS phylogeny. The ITS phylogeny was used to analyse correspondence with Roessler’s (1959) Series. It was found that the phylogeny showed considerable agreement with Roessler’s series, but B. bipinnatifida and B. spinosa of Series Speciosae may require some revision as well as taxa of monotypic series Cruciatae and Angustae. It is suggested that the latter series be merged with Cullumia species to form a single series. Some consideration should be taken to include Didelta species into Series Fruticosae as Didelta occurs in subclade 5b of Clade 5 with other Series Fruticosae taxa. Achene morphology was examined from species from each of the five clades to investigate the relationships of Berkheya and its allies, as well as to determine if there were any consistent achene features for each clade. The structure of surface cells on the fruit, the presence, absence and morphology of twin hairs as well as the structure of the pappus scales were found to be most useful in reflecting phylogenetic relationships within the clades. When compared with the clades of the ITS phylogeny, achene morphology showed consistent characters between taxa occurring in the same clades. As the most comprehensive study involving Berkheya, this phylogenenetic investigation was able to confirm that Berkheya is a paraphyletic genus with Didelta, Cullumia and Cuspida needing to be subsumed into Berkheya. An alternative classification is that taxa of Clade 5 could possibly be erected as an expanded Didelta, separate and sister to Berkheya.
- Full Text:
- Date Issued: 2013
An investigation into how grade 10 learners make meaning during the teaching and learning of the topic on nutrition in Life Science: a case study
- Mwiikeni, Helena Twiihaleni, Shimwafeni-Mwiikeni, Helena Twiihaleni
- Authors: Mwiikeni, Helena Twiihaleni , Shimwafeni-Mwiikeni, Helena Twiihaleni
- Date: 2013
- Subjects: Nutrition -- Study and teaching (Secondary) -- Namibia -- Oshana -- Case studies Environmental sciences -- Study and teaching (Secondary) -- Namibia -- Oshana -- Case studies Experiential learning -- Namibia -- Oshana -- Case studies Education, Secondary -- Namibia -- Oshana
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1403 , http://hdl.handle.net/10962/d1001876
- Description: The integration of learners’ prior everyday knowledge and experiences during teaching and learning is a pre-requisite in the Namibian curriculum. The curriculum states that if learners are taught in a way which builds on what they already know and they relate new knowledge to the reality around them, their learning in school can be made more meaningful. Thus, learners’ meaning making in the topic on nutrition was researched to find out whether elicitation and integration of learners’ prior everyday knowledge and experience in the nutrition topic enhanced or constrained their learning. This study was conducted with my grade10 learners at the school where I am currently teaching. The school is located in a rural area in Oshana region in Northern Namibia. This study is situated within an interpretive paradigm. Within the interpretive paradigm a qualitative case study approach was adopted. I considered this methodological orientation appropriate in this study as it allowed me to use the following methods: document analysis, brainstorming and discussion, semi-structured interviews and a focus group interview, practical activities with worksheets and observation and reflection. Multiple methods to gather data were used for triangulation and validation purposes. For data analysis purposes, the data sets were colour coded to derive themes and analytical statements. Ethical consideration was also taken seriously in this study. The findings from this study revealed that integration of learners’ prior everyday knowledge and experience enabled learners to understand science better particularly in the topic of nutrition. The study also revealed that learners possess a lot of prior everyday knowledge and experience about food they eat in their homes. However, data from the community members revealed that there are some contradictions between learners’ prior everyday knowledge and the science content of the topic. Nonetheless, engaging learners in practical activities in the testing of food (local and conventional western type foods) helped them to make meaning of the content learned. I therefore, recommend that learners’ prior everyday knowledge and experiences should be incorporated during teaching and learning of the topic on nutrition. The study also recommends that the Department of Education should ensure that teachers get the necessary support and training on how to integrate learners’ prior everyday knowledge and experiences.
- Full Text:
- Date Issued: 2013
- Authors: Mwiikeni, Helena Twiihaleni , Shimwafeni-Mwiikeni, Helena Twiihaleni
- Date: 2013
- Subjects: Nutrition -- Study and teaching (Secondary) -- Namibia -- Oshana -- Case studies Environmental sciences -- Study and teaching (Secondary) -- Namibia -- Oshana -- Case studies Experiential learning -- Namibia -- Oshana -- Case studies Education, Secondary -- Namibia -- Oshana
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1403 , http://hdl.handle.net/10962/d1001876
- Description: The integration of learners’ prior everyday knowledge and experiences during teaching and learning is a pre-requisite in the Namibian curriculum. The curriculum states that if learners are taught in a way which builds on what they already know and they relate new knowledge to the reality around them, their learning in school can be made more meaningful. Thus, learners’ meaning making in the topic on nutrition was researched to find out whether elicitation and integration of learners’ prior everyday knowledge and experience in the nutrition topic enhanced or constrained their learning. This study was conducted with my grade10 learners at the school where I am currently teaching. The school is located in a rural area in Oshana region in Northern Namibia. This study is situated within an interpretive paradigm. Within the interpretive paradigm a qualitative case study approach was adopted. I considered this methodological orientation appropriate in this study as it allowed me to use the following methods: document analysis, brainstorming and discussion, semi-structured interviews and a focus group interview, practical activities with worksheets and observation and reflection. Multiple methods to gather data were used for triangulation and validation purposes. For data analysis purposes, the data sets were colour coded to derive themes and analytical statements. Ethical consideration was also taken seriously in this study. The findings from this study revealed that integration of learners’ prior everyday knowledge and experience enabled learners to understand science better particularly in the topic of nutrition. The study also revealed that learners possess a lot of prior everyday knowledge and experience about food they eat in their homes. However, data from the community members revealed that there are some contradictions between learners’ prior everyday knowledge and the science content of the topic. Nonetheless, engaging learners in practical activities in the testing of food (local and conventional western type foods) helped them to make meaning of the content learned. I therefore, recommend that learners’ prior everyday knowledge and experiences should be incorporated during teaching and learning of the topic on nutrition. The study also recommends that the Department of Education should ensure that teachers get the necessary support and training on how to integrate learners’ prior everyday knowledge and experiences.
- Full Text:
- Date Issued: 2013
Waste management in the pharmaceutical industry : an evaluation report of Dr Reddy's Laboratories
- Authors: Letsitsi, Ezekiel Tebogo
- Date: 2013
- Subjects: Pharmaceutical industry -- Waste disposal -- Case studies Hazardous wastes -- Management -- South Africa Hazardous wastes -- Management -- Law and legislation -- South Africa , Dr Reddy's Laboratories
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:718 , http://hdl.handle.net/10962/d1001872
- Description: The pharmaceutical industry must worry about managing pharmaceutical waste as it poses a health risk to human beings and its presence in the environment can also contribute to loss of biodiversity. Ngwuluka, Ochekpe, and Odumosu (2011: 11259) state that “Pharmaceuticals, though used to treat and manage diseases, are poisons, which justify the growing concerns about their presence in the environment.” Various forms of pharmaceutical waste exist, Ngwuluka et al. (2011) identified the following forms of pharmaceutical waste: Expired dosage forms, non-reworkable formulations, spilled pharmaceuticals, rejected active pharmaceutical ingredients, expired active pharmaceutical ingredients, and wastewater resulting from the water used for process operations during manufacturing and could come from the water used to clean equipment, pipes and floors, and would contain amongst other materials, chemicals and active pharmaceutical ingredients (APIs). A review on the pharmaceutical industry and the progress they have made in environmental management by generating health, safety and environmental programs, preventing pollution, waste minimization, recycling and reusing materials, investing in projects and facilities to ensure environmental sustainability have been established (Berry & Rondinelli, 2000). Dr. Reddy’s Laboratories is an Indian based pharmaceutical company which imports, markets and sells medicines in South Africa. Dr. Reddy’s has plans to set up a manufacturing plant in South Africa. The purpose of this study is to research waste management practices at Dr. Reddy’s plant in India and to draw parallels between India’s and South Africa’s waste legislation. This is to enable Dr. Reddy’s to review all aspects of its waste management systems, in order to revise where necessary and to improve the overall achievement of its waste management objectives in order to become a more sustainable organisation and to meet South African Waste legislation before setting up a plant in South Africa. 3 ii. Objective of the Evaluation Report The purpose of this research is to evaluate and analyse the development and implementation of a waste management system in a pharmaceutical company, specifically Dr. Reddy’s Laboratories. This is primarily to enable the company to review and analyse all aspects of waste management pertaining to pharmaceutical manufacturing and to revise or improve where necessary to ensure adherence to waste regulations as outlined by government. The following research goals have been also been identified: To identify and describe waste management practices at Dr. Reddy’s Laboratories, on the inherent assumption by the researcher that the company has a successful waste management strategy that would need to be reviewed to identify areas of improvement before expanding manufacturing facilities into South Africa. To evaluate, assess and compare similarities and/or differences between the identified South African Legislation for Waste Management with those identified during research conducted at Dr. Reddy’s iii. Importance of the Research Conducted Waste Management is important in that it not only removes from the environment, substances that can be harmful to humans and animals but it also enables an organisation to be more sustainable. According to Seadon (2010: i) “Integrated waste management is considered from a systems’ approach, with a particular emphasis on advancing sustainability”. The study will provide guidance to senior management, shop floor managers and employees who work in Dr. Reddy’s manufacturing plants as well as overall employees at Dr. Reddy’s on how to successfully implement a Waste Management programme to enhance sustainability at the organisation and realise the benefits to the organisation of being more sustainable. Weybrecht (2010) identified the following benefits that companies could gain by adopting sustainable waste management practices: reduced costs, resource preservation, keeping up with legislation, enhanced reputation, business differentiation from competitors, and attraction and retention of quality employees, and customer need satisfaction amongst many other benefits. This research needs to address the gap in analysing waste management practices (with more emphasis on waste treatment, waste minimisation, re-use, recycling and disposal), and implementation and understanding of waste management in the pharmaceutical industry as prior research was done mostly in other chemical industries and not to a large scale in the pharmaceutical industry. South African Waste Legislation, Indian Waste Legislation (as Dr. Reddy’s is based in India), as well as International Pharmaceutical Waste Management Guidelines, and International Pharmaceutical Good Manufacturing Practices provide a framework and benchmark of leading pharmaceutical waste management practices that can guide Dr. Reddy’s Laboratories’ leadership into integrating their waste management practices into their plans of setting up a manufacturing plant in South Africa. 5. Research Methodology This is evaluation research in the form of a case study and the data collection method employed is the conduction of a survey through questionnaires. The evaluation research also involves a document analysis of the organisation’s 2011 and 2012 annual reports, Dr. Reddy’s 2010 Sustainability Report as well as literature compiled by the organisation’s Corporate Communications Division. The research would also include review of existing literature on waste management. v. Structure of Dissertation This dissertation consists of three sections. Section 1: The Evaluation Report The section introduces the research area, provides the objectives of the research, provides contextual background information and describes the rationale for conducting the research. This section further describes Dr. Reddy’s waste management practice as outlined in relevant company documentation; it is also intended to highlight the specific waste management processes that were followed in the formulation and implementation of the waste management strategy. This section further describes the sample and presents the results of the survey, where the results are collated and reviewed in the context of the criteria set in the South African Waste Legislation, Indian Waste Legislation, as well as in International Pharmaceutical Waste Management Guidelines, and International Pharmaceutical Good Manufacturing Practices. The overall findings of this case study suggest that although management at Dr. Reddy’s are satisfied with waste management practices and results achieved at it manufacturing plant, there is however dissatisfaction amongst employees who believe the organisation has not successfully disseminated information and sufficiently trained them on waste management policies, processes and practices. There is therefore a desire amongst employees to be trained and to see the company improve on its waste management processes, this desire is a very important attribute as it indicates that employees at Dr. Reddy understand and are committed to the importance of waste management. Future research should be conducted to measure the legal impact of non-compliance to legislation governing waste management in the pharmaceutical company. Section 2: Literature Review The objective of the literature review is to provide a critical assessment and evaluation of previous research in the field of waste management in general as prior research was done mostly in other industries and not to a large scale in the pharmaceutical industry. The literature review evaluates the key elements of an effective waste management strategy implementation and is followed by a review of literature pertaining to the description of Pharmaceutical waste. Section 3: Research Methodology This section presents a description of how the work in this research was conducted. It presents the research process followed in compiling this case study, represented by the aims and objectives, research methodology and design, data collection techniques and data analysis.
- Full Text:
- Date Issued: 2013
- Authors: Letsitsi, Ezekiel Tebogo
- Date: 2013
- Subjects: Pharmaceutical industry -- Waste disposal -- Case studies Hazardous wastes -- Management -- South Africa Hazardous wastes -- Management -- Law and legislation -- South Africa , Dr Reddy's Laboratories
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:718 , http://hdl.handle.net/10962/d1001872
- Description: The pharmaceutical industry must worry about managing pharmaceutical waste as it poses a health risk to human beings and its presence in the environment can also contribute to loss of biodiversity. Ngwuluka, Ochekpe, and Odumosu (2011: 11259) state that “Pharmaceuticals, though used to treat and manage diseases, are poisons, which justify the growing concerns about their presence in the environment.” Various forms of pharmaceutical waste exist, Ngwuluka et al. (2011) identified the following forms of pharmaceutical waste: Expired dosage forms, non-reworkable formulations, spilled pharmaceuticals, rejected active pharmaceutical ingredients, expired active pharmaceutical ingredients, and wastewater resulting from the water used for process operations during manufacturing and could come from the water used to clean equipment, pipes and floors, and would contain amongst other materials, chemicals and active pharmaceutical ingredients (APIs). A review on the pharmaceutical industry and the progress they have made in environmental management by generating health, safety and environmental programs, preventing pollution, waste minimization, recycling and reusing materials, investing in projects and facilities to ensure environmental sustainability have been established (Berry & Rondinelli, 2000). Dr. Reddy’s Laboratories is an Indian based pharmaceutical company which imports, markets and sells medicines in South Africa. Dr. Reddy’s has plans to set up a manufacturing plant in South Africa. The purpose of this study is to research waste management practices at Dr. Reddy’s plant in India and to draw parallels between India’s and South Africa’s waste legislation. This is to enable Dr. Reddy’s to review all aspects of its waste management systems, in order to revise where necessary and to improve the overall achievement of its waste management objectives in order to become a more sustainable organisation and to meet South African Waste legislation before setting up a plant in South Africa. 3 ii. Objective of the Evaluation Report The purpose of this research is to evaluate and analyse the development and implementation of a waste management system in a pharmaceutical company, specifically Dr. Reddy’s Laboratories. This is primarily to enable the company to review and analyse all aspects of waste management pertaining to pharmaceutical manufacturing and to revise or improve where necessary to ensure adherence to waste regulations as outlined by government. The following research goals have been also been identified: To identify and describe waste management practices at Dr. Reddy’s Laboratories, on the inherent assumption by the researcher that the company has a successful waste management strategy that would need to be reviewed to identify areas of improvement before expanding manufacturing facilities into South Africa. To evaluate, assess and compare similarities and/or differences between the identified South African Legislation for Waste Management with those identified during research conducted at Dr. Reddy’s iii. Importance of the Research Conducted Waste Management is important in that it not only removes from the environment, substances that can be harmful to humans and animals but it also enables an organisation to be more sustainable. According to Seadon (2010: i) “Integrated waste management is considered from a systems’ approach, with a particular emphasis on advancing sustainability”. The study will provide guidance to senior management, shop floor managers and employees who work in Dr. Reddy’s manufacturing plants as well as overall employees at Dr. Reddy’s on how to successfully implement a Waste Management programme to enhance sustainability at the organisation and realise the benefits to the organisation of being more sustainable. Weybrecht (2010) identified the following benefits that companies could gain by adopting sustainable waste management practices: reduced costs, resource preservation, keeping up with legislation, enhanced reputation, business differentiation from competitors, and attraction and retention of quality employees, and customer need satisfaction amongst many other benefits. This research needs to address the gap in analysing waste management practices (with more emphasis on waste treatment, waste minimisation, re-use, recycling and disposal), and implementation and understanding of waste management in the pharmaceutical industry as prior research was done mostly in other chemical industries and not to a large scale in the pharmaceutical industry. South African Waste Legislation, Indian Waste Legislation (as Dr. Reddy’s is based in India), as well as International Pharmaceutical Waste Management Guidelines, and International Pharmaceutical Good Manufacturing Practices provide a framework and benchmark of leading pharmaceutical waste management practices that can guide Dr. Reddy’s Laboratories’ leadership into integrating their waste management practices into their plans of setting up a manufacturing plant in South Africa. 5. Research Methodology This is evaluation research in the form of a case study and the data collection method employed is the conduction of a survey through questionnaires. The evaluation research also involves a document analysis of the organisation’s 2011 and 2012 annual reports, Dr. Reddy’s 2010 Sustainability Report as well as literature compiled by the organisation’s Corporate Communications Division. The research would also include review of existing literature on waste management. v. Structure of Dissertation This dissertation consists of three sections. Section 1: The Evaluation Report The section introduces the research area, provides the objectives of the research, provides contextual background information and describes the rationale for conducting the research. This section further describes Dr. Reddy’s waste management practice as outlined in relevant company documentation; it is also intended to highlight the specific waste management processes that were followed in the formulation and implementation of the waste management strategy. This section further describes the sample and presents the results of the survey, where the results are collated and reviewed in the context of the criteria set in the South African Waste Legislation, Indian Waste Legislation, as well as in International Pharmaceutical Waste Management Guidelines, and International Pharmaceutical Good Manufacturing Practices. The overall findings of this case study suggest that although management at Dr. Reddy’s are satisfied with waste management practices and results achieved at it manufacturing plant, there is however dissatisfaction amongst employees who believe the organisation has not successfully disseminated information and sufficiently trained them on waste management policies, processes and practices. There is therefore a desire amongst employees to be trained and to see the company improve on its waste management processes, this desire is a very important attribute as it indicates that employees at Dr. Reddy understand and are committed to the importance of waste management. Future research should be conducted to measure the legal impact of non-compliance to legislation governing waste management in the pharmaceutical company. Section 2: Literature Review The objective of the literature review is to provide a critical assessment and evaluation of previous research in the field of waste management in general as prior research was done mostly in other industries and not to a large scale in the pharmaceutical industry. The literature review evaluates the key elements of an effective waste management strategy implementation and is followed by a review of literature pertaining to the description of Pharmaceutical waste. Section 3: Research Methodology This section presents a description of how the work in this research was conducted. It presents the research process followed in compiling this case study, represented by the aims and objectives, research methodology and design, data collection techniques and data analysis.
- Full Text:
- Date Issued: 2013
Case study : using visual representations to enhance conceptual knowledge of division in mathematics
- Authors: Joel, Linea Beautty
- Date: 2013
- Subjects: Mathematics -- Study and teaching , Visual learning , Division -- Study and teaching
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1992 , http://hdl.handle.net/10962/d1013356
- Description: Literature emphasizes how important it is that procedural and conceptual knowledge of mathematics should be learned in integration. Yet, generally, the learning and teaching in mathematics classrooms relies heavily on isolated procedures. This study aims to improve teaching and learning of partitive and quotitive division, moving away from isolated procedural knowledge to that of procedures with their underlying concepts through the use of manipulatives, visual representation and questioning. Learning and teaching lessons were designed to teach partitive and quotitive division both procedurally and conceptually. The study explored the roles these manipulatives, visual representations and questioning played toward the conceptual learning of partitive and quotitive division. It was found that manipulatives and iconic visualization enhanced learning, and this could be achieved through scaffolding using a questioning approach. It was concluded that manipulatives and iconic visualization need to be properly planned and used, and integrated with questioning to achieve success in the learning of procedural and conceptual knowledge.
- Full Text:
- Date Issued: 2013
Case study : using visual representations to enhance conceptual knowledge of division in mathematics
- Authors: Joel, Linea Beautty
- Date: 2013
- Subjects: Mathematics -- Study and teaching , Visual learning , Division -- Study and teaching
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1992 , http://hdl.handle.net/10962/d1013356
- Description: Literature emphasizes how important it is that procedural and conceptual knowledge of mathematics should be learned in integration. Yet, generally, the learning and teaching in mathematics classrooms relies heavily on isolated procedures. This study aims to improve teaching and learning of partitive and quotitive division, moving away from isolated procedural knowledge to that of procedures with their underlying concepts through the use of manipulatives, visual representation and questioning. Learning and teaching lessons were designed to teach partitive and quotitive division both procedurally and conceptually. The study explored the roles these manipulatives, visual representations and questioning played toward the conceptual learning of partitive and quotitive division. It was found that manipulatives and iconic visualization enhanced learning, and this could be achieved through scaffolding using a questioning approach. It was concluded that manipulatives and iconic visualization need to be properly planned and used, and integrated with questioning to achieve success in the learning of procedural and conceptual knowledge.
- Full Text:
- Date Issued: 2013
Selected physiological and perceptual responses of batsmen during a simulated one day international century : impact on performance
- Authors: Pote, Lee
- Date: 2013 , 2013-04-02
- Subjects: Cricket -- Batting , Sports -- Physiological aspects , Sports -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5097 , http://hdl.handle.net/10962/d1001650
- Description: Background: Very few studies have examined the demands of prolonged batting on physical, psychophysical and performance responses. Objective: The purpose of this study was therefore to determine the physiological and perceptual responses of batsmen scoring a simulated One Day International century. Furthermore, the impact that these responses had on batting performance were also measured. Methods: Seventeen male cricketers currently playing for Rhodes University or the country districts side, performed a simulated bating innings (BATEX©), typical of scoring a One Day international century. The BATEX© protocol consisted of six, five over stages (21 minutes each), with each stage matched to a specific phase of play where batsmen were encouraged to bat with the mindset of that phase. During stages one, three and five players ran at a “self-selected cruise pace” whereas during stages two, four and six players were required to run at maximum speed. At set intervals, selected physiological, perceptual and performance measures were recorded. Results: Most physiological responses increased and decreased accordingly with the low and high intensity stages with the exception of respiratory exchange ratio and core temperature responses. Mean physiological responses however, showed a progressive rise over time. Central ratings of perceived exertion increased as a function of intensity and duration. Sprint times got slower as the protocol progressed, while accuracy (impact accuracy) improved significantly (p<0.05) after stage one and then stabilised for the remainder of the protocol. Conclusion: The simulated batting protocol significantly impacted the physiological and perceptual responses over time. This was due to both the intensity and the duration of the work-bout. Furthermore, the increased physiological load placed on the batsmen significantly impacted the physical performance of the batsmen. An increase in sprint times (players getting slower) towards the end of the protocol may indicate the presence of physical fatigue. This physical fatigue did not however seem to impact the batsmen cognitively as accuracy improved after the first stage and then remained constant over time.
- Full Text:
- Date Issued: 2013
- Authors: Pote, Lee
- Date: 2013 , 2013-04-02
- Subjects: Cricket -- Batting , Sports -- Physiological aspects , Sports -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5097 , http://hdl.handle.net/10962/d1001650
- Description: Background: Very few studies have examined the demands of prolonged batting on physical, psychophysical and performance responses. Objective: The purpose of this study was therefore to determine the physiological and perceptual responses of batsmen scoring a simulated One Day International century. Furthermore, the impact that these responses had on batting performance were also measured. Methods: Seventeen male cricketers currently playing for Rhodes University or the country districts side, performed a simulated bating innings (BATEX©), typical of scoring a One Day international century. The BATEX© protocol consisted of six, five over stages (21 minutes each), with each stage matched to a specific phase of play where batsmen were encouraged to bat with the mindset of that phase. During stages one, three and five players ran at a “self-selected cruise pace” whereas during stages two, four and six players were required to run at maximum speed. At set intervals, selected physiological, perceptual and performance measures were recorded. Results: Most physiological responses increased and decreased accordingly with the low and high intensity stages with the exception of respiratory exchange ratio and core temperature responses. Mean physiological responses however, showed a progressive rise over time. Central ratings of perceived exertion increased as a function of intensity and duration. Sprint times got slower as the protocol progressed, while accuracy (impact accuracy) improved significantly (p<0.05) after stage one and then stabilised for the remainder of the protocol. Conclusion: The simulated batting protocol significantly impacted the physiological and perceptual responses over time. This was due to both the intensity and the duration of the work-bout. Furthermore, the increased physiological load placed on the batsmen significantly impacted the physical performance of the batsmen. An increase in sprint times (players getting slower) towards the end of the protocol may indicate the presence of physical fatigue. This physical fatigue did not however seem to impact the batsmen cognitively as accuracy improved after the first stage and then remained constant over time.
- Full Text:
- Date Issued: 2013
An investigation into the school experiences of HIV-positive secondary school learners on ARV treatment in Katutura, Windhoek
- Authors: Haipinge, Emilie
- Date: 2013
- Subjects: HIV-positive youth -- Namibia -- Katutura (Windhoek) HIV-positive youth -- Social conditions -- Namibia -- Katutura (Windhoek) HIV infections -- Social aspects -- Namibia -- Katutura (Windhoek) HIV infections -- Psychological aspects -- Namibia -- Katutura (Windhoek) AIDS phobia -- Namibia -- Katutura (Windhoek) Antiretroviral agents
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1837 , http://hdl.handle.net/10962/d1004334
- Description: What are the school experiences of HIV-positive secondary school learners on ARV treatment? Although the provision of life-saving antiretroviral (ARV) treatment is central in the medical and policy response to the HIV pandemic, relatively little research (in the SADC region and in Namibia particularly) attends to people’s experiences and the social effects of taking ARV treatment. This study probed the experiences of high school learners on ARV treatment in Khomas Region, Namibia. As researcher I used a qualitative case study design based mainly on interviews with a purposive, select sample of eight learners at the school where I am a teacher-counsellor. Methods used also included: observations; focus group interviews with eight teachers at the site school; a questionnaire survey with Life Skills teachers from 25 schools in the Khomas Region; and document analysis. Using a theory of health-related stigma and discrimination as well as perspectives on resilience and agency as conceptual and analytical lenses, this study found that only a handful of these learners were living openly with HIV and AIDS. Being both HIV-positive and on ARV medication was a double bind for learners facing pervasive stigma and discrimination in and out of school. Discourses associated with HIV and AIDS, sex, and sexuality shaped people’s response to them and they feared being ‘caught out’. Here the study explores the complex reciprocal relationship between cause and effect in stigma, showing some consequences for these learners: isolation (both voluntary and imposed), mental anguish, depression and suicidal leanings; also (at school) absenteeism, grade repetition and dropout. Distinguishing stigma from discrimination in this study enabled insight into actual practices that constrain learner participation and inclusion in and out of school. Trust between learners on ARVs and teachers proved to be low. Teacher respondents not only felt unequipped to deal with the psychosocial needs of learners on ARVs but also indicated that confronting these needs animated their personal vulnerability (around HIV-related experiences in their own families). However, hopeful patterns also emerged. Some mediatory factors out of school shaped these learners’ experiences and identities positively, with implications for in-school experiences and participation. Some learner journeys reflected shifts from deep despair towards the emergence of voice, positive self-concepts and resilient dispositions. Here, also, this study enters a neglected area of research, showing how the complex interplay of learners’ own agency with social support brought these positive outcomes. Most learners had experienced rejection from immediate family, receiving support rather from community members who became ‘family’. The study thus also raises pressing questions on the nature of support structures (both in and out of school) in contexts shaped by HIV and AIDS, where stigma and discrimination are pervasive and where stable family structures, parental oversight and ‘normal’ progression through school cannot be assumed. It recommends that schools gain better insight into how learners’ circumstances shape their experiences, and develop internal policies, procedures and networks to reduce stigma and discrimination against HIV-positive learners on ARV treatment, as well as. ensuring material, medical, emotional, and psychological support for them.
- Full Text:
- Date Issued: 2013
- Authors: Haipinge, Emilie
- Date: 2013
- Subjects: HIV-positive youth -- Namibia -- Katutura (Windhoek) HIV-positive youth -- Social conditions -- Namibia -- Katutura (Windhoek) HIV infections -- Social aspects -- Namibia -- Katutura (Windhoek) HIV infections -- Psychological aspects -- Namibia -- Katutura (Windhoek) AIDS phobia -- Namibia -- Katutura (Windhoek) Antiretroviral agents
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1837 , http://hdl.handle.net/10962/d1004334
- Description: What are the school experiences of HIV-positive secondary school learners on ARV treatment? Although the provision of life-saving antiretroviral (ARV) treatment is central in the medical and policy response to the HIV pandemic, relatively little research (in the SADC region and in Namibia particularly) attends to people’s experiences and the social effects of taking ARV treatment. This study probed the experiences of high school learners on ARV treatment in Khomas Region, Namibia. As researcher I used a qualitative case study design based mainly on interviews with a purposive, select sample of eight learners at the school where I am a teacher-counsellor. Methods used also included: observations; focus group interviews with eight teachers at the site school; a questionnaire survey with Life Skills teachers from 25 schools in the Khomas Region; and document analysis. Using a theory of health-related stigma and discrimination as well as perspectives on resilience and agency as conceptual and analytical lenses, this study found that only a handful of these learners were living openly with HIV and AIDS. Being both HIV-positive and on ARV medication was a double bind for learners facing pervasive stigma and discrimination in and out of school. Discourses associated with HIV and AIDS, sex, and sexuality shaped people’s response to them and they feared being ‘caught out’. Here the study explores the complex reciprocal relationship between cause and effect in stigma, showing some consequences for these learners: isolation (both voluntary and imposed), mental anguish, depression and suicidal leanings; also (at school) absenteeism, grade repetition and dropout. Distinguishing stigma from discrimination in this study enabled insight into actual practices that constrain learner participation and inclusion in and out of school. Trust between learners on ARVs and teachers proved to be low. Teacher respondents not only felt unequipped to deal with the psychosocial needs of learners on ARVs but also indicated that confronting these needs animated their personal vulnerability (around HIV-related experiences in their own families). However, hopeful patterns also emerged. Some mediatory factors out of school shaped these learners’ experiences and identities positively, with implications for in-school experiences and participation. Some learner journeys reflected shifts from deep despair towards the emergence of voice, positive self-concepts and resilient dispositions. Here, also, this study enters a neglected area of research, showing how the complex interplay of learners’ own agency with social support brought these positive outcomes. Most learners had experienced rejection from immediate family, receiving support rather from community members who became ‘family’. The study thus also raises pressing questions on the nature of support structures (both in and out of school) in contexts shaped by HIV and AIDS, where stigma and discrimination are pervasive and where stable family structures, parental oversight and ‘normal’ progression through school cannot be assumed. It recommends that schools gain better insight into how learners’ circumstances shape their experiences, and develop internal policies, procedures and networks to reduce stigma and discrimination against HIV-positive learners on ARV treatment, as well as. ensuring material, medical, emotional, and psychological support for them.
- Full Text:
- Date Issued: 2013
Updating the ionospheric propagation factor, M(3000)F2, global model using the neural network technique and relevant geophysical input parameters
- Oronsaye, Samuel Iyen Jeffrey
- Authors: Oronsaye, Samuel Iyen Jeffrey
- Date: 2013
- Subjects: Neural networks (Computer science) , Ionospheric radio wave propagation , Ionosphere , Geophysics , Ionosondes
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5434 , http://hdl.handle.net/10962/d1001609 , Neural networks (Computer science) , Ionospheric radio wave propagation , Ionosphere , Geophysics , Ionosondes
- Description: This thesis presents an update to the ionospheric propagation factor, M(3000)F2, global empirical model developed by Oyeyemi et al. (2007) (NNO). An additional aim of this research was to produce the updated model in a form that could be used within the International Reference Ionosphere (IRI) global model without adding to the complexity of the IRI. M(3000)F2 is the highest frequency at which a radio signal can be received over a distance of 3000 km after reflection in the ionosphere. The study employed the artificial neural network (ANN) technique using relevant geophysical input parameters which are known to influence the M(3000)F2 parameter. Ionosonde data from 135 ionospheric stations globally, including a number of equatorial stations, were available for this work. M(3000)F2 hourly values from 1976 to 2008, spanning all periods of low and high solar activity were used for model development and verification. A preliminary investigation was first carried out using a relatively small dataset to determine the appropriate input parameters for global M(3000)F2 parameter modelling. Inputs representing diurnal variation, seasonal variation, solar variation, modified dip latitude, longitude and latitude were found to be the optimum parameters for modelling the diurnal and seasonal variations of the M(3000)F2 parameter both on a temporal and spatial basis. The outcome of the preliminary study was applied to the overall dataset to develop a comprehensive ANN M(3000)F2 model which displays a remarkable improvement over the NNO model as well as the IRI version. The model shows 7.11% and 3.85% improvement over the NNO model as well as 13.04% and 10.05% over the IRI M(3000)F2 model, around high and low solar activity periods respectively. A comparison of the diurnal structure of the ANN and the IRI predicted values reveal that the ANN model is more effective in representing the diurnal structure of the M(3000)F2 values than the IRI M(3000)F2 model. The capability of the ANN model in reproducing the seasonal variation pattern of the M(3000)F2 values at 00h00UT, 06h00UT, 12h00UT, and l8h00UT more appropriately than the IRI version is illustrated in this work. A significant result obtained in this study is the ability of the ANN model in improving the post-sunset predicted values of the M(3000)F2 parameter which is known to be problematic to the IRI M(3000)F2 model in the low-latitude and the equatorial regions. The final M(3000)F2 model provides for an improved equatorial prediction and a simplified input space that allows for easy incorporation into the IRI model.
- Full Text:
- Date Issued: 2013
- Authors: Oronsaye, Samuel Iyen Jeffrey
- Date: 2013
- Subjects: Neural networks (Computer science) , Ionospheric radio wave propagation , Ionosphere , Geophysics , Ionosondes
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5434 , http://hdl.handle.net/10962/d1001609 , Neural networks (Computer science) , Ionospheric radio wave propagation , Ionosphere , Geophysics , Ionosondes
- Description: This thesis presents an update to the ionospheric propagation factor, M(3000)F2, global empirical model developed by Oyeyemi et al. (2007) (NNO). An additional aim of this research was to produce the updated model in a form that could be used within the International Reference Ionosphere (IRI) global model without adding to the complexity of the IRI. M(3000)F2 is the highest frequency at which a radio signal can be received over a distance of 3000 km after reflection in the ionosphere. The study employed the artificial neural network (ANN) technique using relevant geophysical input parameters which are known to influence the M(3000)F2 parameter. Ionosonde data from 135 ionospheric stations globally, including a number of equatorial stations, were available for this work. M(3000)F2 hourly values from 1976 to 2008, spanning all periods of low and high solar activity were used for model development and verification. A preliminary investigation was first carried out using a relatively small dataset to determine the appropriate input parameters for global M(3000)F2 parameter modelling. Inputs representing diurnal variation, seasonal variation, solar variation, modified dip latitude, longitude and latitude were found to be the optimum parameters for modelling the diurnal and seasonal variations of the M(3000)F2 parameter both on a temporal and spatial basis. The outcome of the preliminary study was applied to the overall dataset to develop a comprehensive ANN M(3000)F2 model which displays a remarkable improvement over the NNO model as well as the IRI version. The model shows 7.11% and 3.85% improvement over the NNO model as well as 13.04% and 10.05% over the IRI M(3000)F2 model, around high and low solar activity periods respectively. A comparison of the diurnal structure of the ANN and the IRI predicted values reveal that the ANN model is more effective in representing the diurnal structure of the M(3000)F2 values than the IRI M(3000)F2 model. The capability of the ANN model in reproducing the seasonal variation pattern of the M(3000)F2 values at 00h00UT, 06h00UT, 12h00UT, and l8h00UT more appropriately than the IRI version is illustrated in this work. A significant result obtained in this study is the ability of the ANN model in improving the post-sunset predicted values of the M(3000)F2 parameter which is known to be problematic to the IRI M(3000)F2 model in the low-latitude and the equatorial regions. The final M(3000)F2 model provides for an improved equatorial prediction and a simplified input space that allows for easy incorporation into the IRI model.
- Full Text:
- Date Issued: 2013
A teaching case study of the strategic alignment of business strategy and information technology strategy at Nedbank
- Authors: Tsoaeli, Tebalo
- Date: 2013
- Subjects: Nedbank Banks and banking -- South Africa Business planning Information technology
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:720 , http://hdl.handle.net/10962/d1001883
- Description: In today’s business world, a lot of organizations are investing heavily in Information Technology (IT) in order to develop a competitive edge. According to Loukis, Sapounas and Milionis (2009:85) “firms all over the world make significant investments in IT aiming to increase their efficiency and effectiveness”. According to Cline and Guynes (2001:10), “during the last 30 years, IT has become an increasingly integral part of business operations”. Most of the times, organizations fail to get real value from the investments made in IT. This is mainly due to the fact that organizations fail to realize the value brought about by aligning IT strategy with Business strategy. Hu and Huang (2004:60) state that “each year organizations invest in IT to improve their competitive advantage and ultimately their business performance; however, more often than not, the anticipated benefits of IT investments fail to materialize due to misalignment of or lack of alignment, between the business and IT strategies”. Henderson and Venkatraman (1999:475) emphasize that “alignment is a desired state for organizations investing in IT that is not always achieved, as it often entails a radical change in the way managers consider IT”. It is through the alignment of IT strategy and Business strategy that organizations are able to realize the value brought about by investing in IT. Papp (2001:20)illustrates that “misalignment can cause problems with not only the development and integration of business and IT strategies, but can actually prevent IT from being fully leveraged to its maximum potential within an organization”. An organization that realizes the value of aligning IT strategy and Business strategy is able to develop a competitive advantage over its competitors. According to Daneshvar and Ramesh (2010:1) “each organization is aware of the special effects, benefits and implication of IT in business performance and also its capacity in building sustainable competitive advantages”.
- Full Text:
- Date Issued: 2013
- Authors: Tsoaeli, Tebalo
- Date: 2013
- Subjects: Nedbank Banks and banking -- South Africa Business planning Information technology
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:720 , http://hdl.handle.net/10962/d1001883
- Description: In today’s business world, a lot of organizations are investing heavily in Information Technology (IT) in order to develop a competitive edge. According to Loukis, Sapounas and Milionis (2009:85) “firms all over the world make significant investments in IT aiming to increase their efficiency and effectiveness”. According to Cline and Guynes (2001:10), “during the last 30 years, IT has become an increasingly integral part of business operations”. Most of the times, organizations fail to get real value from the investments made in IT. This is mainly due to the fact that organizations fail to realize the value brought about by aligning IT strategy with Business strategy. Hu and Huang (2004:60) state that “each year organizations invest in IT to improve their competitive advantage and ultimately their business performance; however, more often than not, the anticipated benefits of IT investments fail to materialize due to misalignment of or lack of alignment, between the business and IT strategies”. Henderson and Venkatraman (1999:475) emphasize that “alignment is a desired state for organizations investing in IT that is not always achieved, as it often entails a radical change in the way managers consider IT”. It is through the alignment of IT strategy and Business strategy that organizations are able to realize the value brought about by investing in IT. Papp (2001:20)illustrates that “misalignment can cause problems with not only the development and integration of business and IT strategies, but can actually prevent IT from being fully leveraged to its maximum potential within an organization”. An organization that realizes the value of aligning IT strategy and Business strategy is able to develop a competitive advantage over its competitors. According to Daneshvar and Ramesh (2010:1) “each organization is aware of the special effects, benefits and implication of IT in business performance and also its capacity in building sustainable competitive advantages”.
- Full Text:
- Date Issued: 2013
An investigation into control mechanisms of driving performance : resource depletion and effort-regulation
- Authors: Louw, Tyron Linton
- Date: 2013
- Subjects: Automobile driving simulators , Automobile driving -- Psychological aspects , Automobile driving -- Physiological aspects , Traffic accidents , Traffic safety , Fatigue
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5101 , http://hdl.handle.net/10962/d1001842 , Automobile driving simulators , Automobile driving -- Psychological aspects , Automobile driving -- Physiological aspects , Traffic accidents , Traffic safety , Fatigue
- Description: Driver fatigue is a complex phenomenon that has a range of causal factors including sleeprelated and task-related factors. These manifest as different safety and performance outcomes. Extensive research has been applied to linking these factors to performance impairment. However, little research focuses on the mechanisms by which this link exists. This research project therefore focuses on the processes underlying how driving performance is controlled and maintained during the development on non-sleep-related driver fatigue. The main aim was to establish whether progressive impairment of driving control over a prolonged drive could be attributed to a depletion of attentional resources, as proposed by Resource Theory, or to a withdrawal of effort, as proposed by Effort-Regulation Theory. As a multicomponent skill, driving requires perception, cognition and motor output. The secondary aim of this research was therefore to assess whether a prolonged drive impairs stage-specific information processing. Participants (n=24) in three experimental groups performed a 90-minute simulated drive wherein they were expected to keep the bonnet of a car on a lane (tracking task). The three groups differed in terms of lane width: small, medium and large, corresponding to low, medium, and high task-demand, respectively. To assess the impacts of this task on stagespecific information processing, participants performed a set of resource specific tests before and after the prolonged drive. Each task had two difficulty variations to ensure that performance decrement was due not only to the task-characteristic, but specifically to resource depletion. The tests probing information processing were: a modified Fitts' tapping task for motor programming, a digit recall task for perception, and an object recognition reading task for cognition. Performance was measured as lateral deviation of the car. Physiological measures included heart rate frequency (HR) and various time- and frequencydomain heart rate variability (HRV) parameters, eye blink frequency and duration. The Borg CR-10 scale was used to evaluate subjective effort and fatigue during the task. Driving control declined over time and was supplemented by HR, HRV, blink frequency and duration, indicating an increase in parasympathetic activity (or a reduction in arousal). An increase in blink frequency was considered as a sign of withdrawal of attentional resources over time. Driving control declined to a greater extent in the large road width group and reflected a lower parasympathetic activity, whereas the inverse was observed for the small road width group. Resource tests reveal a non-specific impairment of information processing following the prolonged drive. However, this was accompanied by an increase in parasympathetic activity. Overall, results indicate that Effort-Regulation Theory better accounts for the impairment of driving control in prolonged driving than does Resource Theory. This suggests that the impact of fatigue is guided more by task goals and intrinsic motivation than by the manner in which the fatigue state developed. Moreover, performance impairment by effort-regulation is dependant more on time on task than on task-demand
- Full Text:
- Date Issued: 2013
- Authors: Louw, Tyron Linton
- Date: 2013
- Subjects: Automobile driving simulators , Automobile driving -- Psychological aspects , Automobile driving -- Physiological aspects , Traffic accidents , Traffic safety , Fatigue
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5101 , http://hdl.handle.net/10962/d1001842 , Automobile driving simulators , Automobile driving -- Psychological aspects , Automobile driving -- Physiological aspects , Traffic accidents , Traffic safety , Fatigue
- Description: Driver fatigue is a complex phenomenon that has a range of causal factors including sleeprelated and task-related factors. These manifest as different safety and performance outcomes. Extensive research has been applied to linking these factors to performance impairment. However, little research focuses on the mechanisms by which this link exists. This research project therefore focuses on the processes underlying how driving performance is controlled and maintained during the development on non-sleep-related driver fatigue. The main aim was to establish whether progressive impairment of driving control over a prolonged drive could be attributed to a depletion of attentional resources, as proposed by Resource Theory, or to a withdrawal of effort, as proposed by Effort-Regulation Theory. As a multicomponent skill, driving requires perception, cognition and motor output. The secondary aim of this research was therefore to assess whether a prolonged drive impairs stage-specific information processing. Participants (n=24) in three experimental groups performed a 90-minute simulated drive wherein they were expected to keep the bonnet of a car on a lane (tracking task). The three groups differed in terms of lane width: small, medium and large, corresponding to low, medium, and high task-demand, respectively. To assess the impacts of this task on stagespecific information processing, participants performed a set of resource specific tests before and after the prolonged drive. Each task had two difficulty variations to ensure that performance decrement was due not only to the task-characteristic, but specifically to resource depletion. The tests probing information processing were: a modified Fitts' tapping task for motor programming, a digit recall task for perception, and an object recognition reading task for cognition. Performance was measured as lateral deviation of the car. Physiological measures included heart rate frequency (HR) and various time- and frequencydomain heart rate variability (HRV) parameters, eye blink frequency and duration. The Borg CR-10 scale was used to evaluate subjective effort and fatigue during the task. Driving control declined over time and was supplemented by HR, HRV, blink frequency and duration, indicating an increase in parasympathetic activity (or a reduction in arousal). An increase in blink frequency was considered as a sign of withdrawal of attentional resources over time. Driving control declined to a greater extent in the large road width group and reflected a lower parasympathetic activity, whereas the inverse was observed for the small road width group. Resource tests reveal a non-specific impairment of information processing following the prolonged drive. However, this was accompanied by an increase in parasympathetic activity. Overall, results indicate that Effort-Regulation Theory better accounts for the impairment of driving control in prolonged driving than does Resource Theory. This suggests that the impact of fatigue is guided more by task goals and intrinsic motivation than by the manner in which the fatigue state developed. Moreover, performance impairment by effort-regulation is dependant more on time on task than on task-demand
- Full Text:
- Date Issued: 2013
Creating a new declaration of rights : a critical reconstruction of earth jurisprudence's global legislative framework
- Authors: Lenferna, Georges Alexandre
- Date: 2013
- Subjects: Universal Declaration , Rights , Earth , Environment , Ethics , Environmental law, International -- Research , Environmental law, International -- Philosophy , Environmental ethics -- Research , Nature conservation -- Law and legislation -- Research , Jurisprudence -- Research , Law -- Philosophy
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:2704 , http://hdl.handle.net/10962/d1001979
- Description: This thesis aims to critique the Universal Declaration of the Rights of Mother Earth and its underlying moral justification in order to provide a stronger and improved version of both. In Chapter 1 I explore what sort of moral justification is necessary to establish the Universal Declaration on firm grounds and explore its relation to environmental ethics and rights discourse. I argue that a non-anthropocentric perspective is necessary to justify the Universal Declaration’s rights. In Chapter 2 I explore the underlying justification of the Universal Declaration as discovered in the works of Cormac Cullinan and Father Thomas Berry. I argue that their ethical framework is indeterminate, has many ambiguities and uncertainties, and, among other problems, it does not provide a clear action-guiding framework. In Chapter 3 I develop an alternative justification for the Universal Declaration. I argue against many predominant moral theories, that in light of our best scientific and moral understanding we should expand the realm of moral concern to include all living beings, a moral theory I call Life’s Imperative. In Chapter 4 I illustrate that Life’s Imperative is a much stronger, more coherent justification for the Universal Declaration, one that coheres with both our best understanding of the natural world and our relation to it, and to an environmental ethic reflective of that relationship. Unfortunately many of the weaknesses in the current implicit justification of the Universal Declaration have also led to it enshrining rights that are themselves problematic. In order to address these issues, I revise its rights to accord with the stronger justification that I established in Chapter 3. The end result of doing so is a revised version of the Universal Declaration
- Full Text:
- Date Issued: 2013
- Authors: Lenferna, Georges Alexandre
- Date: 2013
- Subjects: Universal Declaration , Rights , Earth , Environment , Ethics , Environmental law, International -- Research , Environmental law, International -- Philosophy , Environmental ethics -- Research , Nature conservation -- Law and legislation -- Research , Jurisprudence -- Research , Law -- Philosophy
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:2704 , http://hdl.handle.net/10962/d1001979
- Description: This thesis aims to critique the Universal Declaration of the Rights of Mother Earth and its underlying moral justification in order to provide a stronger and improved version of both. In Chapter 1 I explore what sort of moral justification is necessary to establish the Universal Declaration on firm grounds and explore its relation to environmental ethics and rights discourse. I argue that a non-anthropocentric perspective is necessary to justify the Universal Declaration’s rights. In Chapter 2 I explore the underlying justification of the Universal Declaration as discovered in the works of Cormac Cullinan and Father Thomas Berry. I argue that their ethical framework is indeterminate, has many ambiguities and uncertainties, and, among other problems, it does not provide a clear action-guiding framework. In Chapter 3 I develop an alternative justification for the Universal Declaration. I argue against many predominant moral theories, that in light of our best scientific and moral understanding we should expand the realm of moral concern to include all living beings, a moral theory I call Life’s Imperative. In Chapter 4 I illustrate that Life’s Imperative is a much stronger, more coherent justification for the Universal Declaration, one that coheres with both our best understanding of the natural world and our relation to it, and to an environmental ethic reflective of that relationship. Unfortunately many of the weaknesses in the current implicit justification of the Universal Declaration have also led to it enshrining rights that are themselves problematic. In order to address these issues, I revise its rights to accord with the stronger justification that I established in Chapter 3. The end result of doing so is a revised version of the Universal Declaration
- Full Text:
- Date Issued: 2013
An exploration of strategies to enhance grade 8 learners' reading comprehension skills
- Authors: Matakane, Euphimia Nobuzwe
- Date: 2013
- Subjects: Reading (Secondary) -- Research Reading comprehension
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1834 , http://hdl.handle.net/10962/d1004330
- Description: This thesis reports on an Action Research case study into the teaching of comprehension strategies to Grade 8 learners in a rural high school in the Eastern Cape, South Africa. The learners in this study, who were studying English as an additional language, experienced difficulties in comprehending English text. A series of six lessons were designed to teach comprehension strategies to improve the learners' performance in reading comprehension. The purpose of the intervention was to equip the learners with skills that would enable them to improve their reading comprehension and evaluate their effectiveness as readers. The intervention was also intended to assess my teaching, which was challenged by the need to deal with learners' poor levels of reading comprehension. The data was collected using the following research techniques: interviews, questionnaires, non-participant observation, learners' and researcher's journals, document analysis The data analysis revealed that a lack of resources to learn English; limited English language due to lack of exposure; and learners' lack of foundational knowledge from their primary schools were barriers to the successful teaching of comprehension strategies. Despite such barriers, however, this research provides evidence that teaching comprehension strategies can be effective if it is taught systematically, and applied continuously. Personally, I learnt that I had to modify my methods of teaching due to the response of learners to the lessons taught.
- Full Text:
- Date Issued: 2013
- Authors: Matakane, Euphimia Nobuzwe
- Date: 2013
- Subjects: Reading (Secondary) -- Research Reading comprehension
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1834 , http://hdl.handle.net/10962/d1004330
- Description: This thesis reports on an Action Research case study into the teaching of comprehension strategies to Grade 8 learners in a rural high school in the Eastern Cape, South Africa. The learners in this study, who were studying English as an additional language, experienced difficulties in comprehending English text. A series of six lessons were designed to teach comprehension strategies to improve the learners' performance in reading comprehension. The purpose of the intervention was to equip the learners with skills that would enable them to improve their reading comprehension and evaluate their effectiveness as readers. The intervention was also intended to assess my teaching, which was challenged by the need to deal with learners' poor levels of reading comprehension. The data was collected using the following research techniques: interviews, questionnaires, non-participant observation, learners' and researcher's journals, document analysis The data analysis revealed that a lack of resources to learn English; limited English language due to lack of exposure; and learners' lack of foundational knowledge from their primary schools were barriers to the successful teaching of comprehension strategies. Despite such barriers, however, this research provides evidence that teaching comprehension strategies can be effective if it is taught systematically, and applied continuously. Personally, I learnt that I had to modify my methods of teaching due to the response of learners to the lessons taught.
- Full Text:
- Date Issued: 2013
Spatial and temporal patterns in the population and the feeding of Palaemon peringueyi (MacPherson 1990) (Decapoda, Palaemonidae) in the Kariega estuary, South Africa
- Nyalungu, Nonhlanhla Precotia Dudu
- Authors: Nyalungu, Nonhlanhla Precotia Dudu
- Date: 2013
- Subjects: Palaemonidae -- Food -- South Africa , Palaemonidae -- Behavior -- South Africa , Palaemonidae -- Habitat -- South Africa , Estuarine biology -- South Africa , Shrimp populations -- South Africa , Shrimps -- South Africa , Decapoda (Crustacea) -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5584 , http://hdl.handle.net/10962/d1001576 , Palaemonidae -- Food -- South Africa , Palaemonidae -- Behavior -- South Africa , Palaemonidae -- Habitat -- South Africa , Estuarine biology -- South Africa , Shrimp populations -- South Africa , Shrimps -- South Africa , Decapoda (Crustacea) -- South Africa
- Description: The spatial and temporal patterns in the population demographs and feeding ecology of the caridean shrimp, Palaemon peringueyi, was investigated over a 12 month period in the permanently open Kariega Estuary situated on the south-east coastline of South Africa. Shrimps were sampled monthly from three stations corresponding to the lower, middle and upper reaches of the Kariega Estuary. The shrimps were collected at the different stations using a pull net. Temperature, salinity, dissolved oxygen and % cover of submerged vegetation were measured at each sampling station. Finally, the feeding ecology of the shrimp was investigated employing stable carbon (δ¹³C) and nitrogen (δ¹⁵N) isotopes analysis. Temperature, salinity, dissolved oxygen and vegetation cover showed distinct seasonal patterns. The shrimps attained total abundances and biomass of between 0 and 245.6 individuals per m² (ind.m⁻²) and between 0 and 13.6 grams wet weight per m² (g wwt.m⁻²), respectively. Mean abundance ranged between 2.3 (± 3.0) and 88 (± 27.3) ind.m⁻² in the lower reach, between 0.9 (± 0.4) to 21.5 (± 4.5) ind.m⁻² in the middle reach and 0 to 1.6 (± 0.5) ind.m⁻² in the upper reach. Mean biomass ranged between 0.4 (± 0.5) and 4.4 (± 1.4) g wwt.m⁻² in the lower reach, between 0.1 (± 0) to 4.3 (± 0.9) g wwt.m⁻² in the middle reach and between 0 to 1.6 (± 0.5) g wwt.m⁻² in the upper reach. Greatest abundances and biomasses were recorded in winter following heavy rainfall within the catchment area. Freshwater inflow which is due to rainfall is thought to provide a cue for the recruitment of marine breeding organisms. The spatial patterns in the distribution of the shrimps showed that juveniles occupied the lower and middle reaches and adults the entire length of the estuary. There were no significant relationships between the abundance and biomass of the shrimps and the selected physico-chemical variables (p > 0.05 in all cases). Results of the stable isotope study indicated that the mean δ¹³C of the shrimps in the lower, middle and upper reaches were -12.4 (± 1.3) ‰, -15.6 (± 0.5) ‰ and -17.5 (± 0.5) ‰, respectively. The δ¹⁵N isotopes of the shrimps in the lower reach was 11.6 (± 0.5) ‰ with middle and upper reaches having similar δ¹⁵N values, 13.5 (± 0.4) ‰ and 13.4 (± 0.4) ‰, respectively. There was no significant difference in the δ¹³C and δ¹⁵N isotope (p > 0.05) between the sexes of the shrimps. Two-way ANOVA indicated a significant difference in the δ¹³C isotope of the shrimps between the sites (p < 0.05). The difference in the δ¹³C and δ¹⁵N ratios of the shrimps suggests spatial variability in the diet of P. peringueyi within the Kariega Estuary. The diet of the shrimps in the lower reach is primarily composed of Nanozostera capensis epibionts. In the middle reach the diet of the shrimps is likely comprised of the detritus of benthic algae. In the upper reach of the estuary, P. peringueyi likely derives its carbon from a combination of epibionts, benthic algae and detritus derived from Codium.
- Full Text:
- Date Issued: 2013
- Authors: Nyalungu, Nonhlanhla Precotia Dudu
- Date: 2013
- Subjects: Palaemonidae -- Food -- South Africa , Palaemonidae -- Behavior -- South Africa , Palaemonidae -- Habitat -- South Africa , Estuarine biology -- South Africa , Shrimp populations -- South Africa , Shrimps -- South Africa , Decapoda (Crustacea) -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5584 , http://hdl.handle.net/10962/d1001576 , Palaemonidae -- Food -- South Africa , Palaemonidae -- Behavior -- South Africa , Palaemonidae -- Habitat -- South Africa , Estuarine biology -- South Africa , Shrimp populations -- South Africa , Shrimps -- South Africa , Decapoda (Crustacea) -- South Africa
- Description: The spatial and temporal patterns in the population demographs and feeding ecology of the caridean shrimp, Palaemon peringueyi, was investigated over a 12 month period in the permanently open Kariega Estuary situated on the south-east coastline of South Africa. Shrimps were sampled monthly from three stations corresponding to the lower, middle and upper reaches of the Kariega Estuary. The shrimps were collected at the different stations using a pull net. Temperature, salinity, dissolved oxygen and % cover of submerged vegetation were measured at each sampling station. Finally, the feeding ecology of the shrimp was investigated employing stable carbon (δ¹³C) and nitrogen (δ¹⁵N) isotopes analysis. Temperature, salinity, dissolved oxygen and vegetation cover showed distinct seasonal patterns. The shrimps attained total abundances and biomass of between 0 and 245.6 individuals per m² (ind.m⁻²) and between 0 and 13.6 grams wet weight per m² (g wwt.m⁻²), respectively. Mean abundance ranged between 2.3 (± 3.0) and 88 (± 27.3) ind.m⁻² in the lower reach, between 0.9 (± 0.4) to 21.5 (± 4.5) ind.m⁻² in the middle reach and 0 to 1.6 (± 0.5) ind.m⁻² in the upper reach. Mean biomass ranged between 0.4 (± 0.5) and 4.4 (± 1.4) g wwt.m⁻² in the lower reach, between 0.1 (± 0) to 4.3 (± 0.9) g wwt.m⁻² in the middle reach and between 0 to 1.6 (± 0.5) g wwt.m⁻² in the upper reach. Greatest abundances and biomasses were recorded in winter following heavy rainfall within the catchment area. Freshwater inflow which is due to rainfall is thought to provide a cue for the recruitment of marine breeding organisms. The spatial patterns in the distribution of the shrimps showed that juveniles occupied the lower and middle reaches and adults the entire length of the estuary. There were no significant relationships between the abundance and biomass of the shrimps and the selected physico-chemical variables (p > 0.05 in all cases). Results of the stable isotope study indicated that the mean δ¹³C of the shrimps in the lower, middle and upper reaches were -12.4 (± 1.3) ‰, -15.6 (± 0.5) ‰ and -17.5 (± 0.5) ‰, respectively. The δ¹⁵N isotopes of the shrimps in the lower reach was 11.6 (± 0.5) ‰ with middle and upper reaches having similar δ¹⁵N values, 13.5 (± 0.4) ‰ and 13.4 (± 0.4) ‰, respectively. There was no significant difference in the δ¹³C and δ¹⁵N isotope (p > 0.05) between the sexes of the shrimps. Two-way ANOVA indicated a significant difference in the δ¹³C isotope of the shrimps between the sites (p < 0.05). The difference in the δ¹³C and δ¹⁵N ratios of the shrimps suggests spatial variability in the diet of P. peringueyi within the Kariega Estuary. The diet of the shrimps in the lower reach is primarily composed of Nanozostera capensis epibionts. In the middle reach the diet of the shrimps is likely comprised of the detritus of benthic algae. In the upper reach of the estuary, P. peringueyi likely derives its carbon from a combination of epibionts, benthic algae and detritus derived from Codium.
- Full Text:
- Date Issued: 2013