A critical analysis of the practical man principle in Commissioner for Inland Revenue v Lever Brothers and Unilever Ltd
- Authors: Grenville, David Paul
- Date: 2014
- Subjects: Unilever (Firm) , South African Revenue Service , Taxation -- Law and legislation -- South Africa , Income tax -- Law and legislation -- South Africa -- Cases , Income tax -- South Africa -- Cases , Business enterprises -- Taxation -- South Africa , Law -- South Africa -- Philosophy
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:909 , http://hdl.handle.net/10962/d1013238
- Description: This research studies the practical person principle as it was introduced in the case of Commissioner for Inland Revenue v Lever Brothers and Unilever Ltd 1946 AD 441. In its time the Lever Brothers case was a seminal judgment in South Africa’s tax jurisprudence and the practical person principle was a decisive criterion for the determination of source of income. The primary goal of this research was a critical analysis the practical man principle. This involved an analysis of the extent to which this principle requires judges to adopt a criterion that is too flexible for legitimate judicial decision-making. The extent to which the practical person principle creates a clash between a philosophical approach to law and an approach that is based on common sense or practicality was also debated. Finally, it was considered whether adopting a philosophical approach to determining the source of income could overcome the problems associated with the practical approach. A doctrinal methodology was applied to the documentary data consisting of the South African and Australian Income Tax Acts, South African and other case law, historical records and the writings of scholars. From the critical analysis of the practical person principle it was concluded that the anthropomorphised form of the principle gives rise to several problems that may be overcome by looking to the underlying operation of the principle. Further analysis of this operation, however, revealed deeper problems in that the principle undermines the doctrine of judicial precedent, legal certainty and the rule of law. Accordingly a practical approach to determining the source of income is undesirable and unconstitutional. Further research was conducted into the relative merits of a philosophical approach to determining source of income and it was argued that such an approach could provide a more desirable solution to determining source of income as well as approaching legal problems more generally.
- Full Text:
- Authors: Grenville, David Paul
- Date: 2014
- Subjects: Unilever (Firm) , South African Revenue Service , Taxation -- Law and legislation -- South Africa , Income tax -- Law and legislation -- South Africa -- Cases , Income tax -- South Africa -- Cases , Business enterprises -- Taxation -- South Africa , Law -- South Africa -- Philosophy
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:909 , http://hdl.handle.net/10962/d1013238
- Description: This research studies the practical person principle as it was introduced in the case of Commissioner for Inland Revenue v Lever Brothers and Unilever Ltd 1946 AD 441. In its time the Lever Brothers case was a seminal judgment in South Africa’s tax jurisprudence and the practical person principle was a decisive criterion for the determination of source of income. The primary goal of this research was a critical analysis the practical man principle. This involved an analysis of the extent to which this principle requires judges to adopt a criterion that is too flexible for legitimate judicial decision-making. The extent to which the practical person principle creates a clash between a philosophical approach to law and an approach that is based on common sense or practicality was also debated. Finally, it was considered whether adopting a philosophical approach to determining the source of income could overcome the problems associated with the practical approach. A doctrinal methodology was applied to the documentary data consisting of the South African and Australian Income Tax Acts, South African and other case law, historical records and the writings of scholars. From the critical analysis of the practical person principle it was concluded that the anthropomorphised form of the principle gives rise to several problems that may be overcome by looking to the underlying operation of the principle. Further analysis of this operation, however, revealed deeper problems in that the principle undermines the doctrine of judicial precedent, legal certainty and the rule of law. Accordingly a practical approach to determining the source of income is undesirable and unconstitutional. Further research was conducted into the relative merits of a philosophical approach to determining source of income and it was argued that such an approach could provide a more desirable solution to determining source of income as well as approaching legal problems more generally.
- Full Text:
A critical analysis of the tax consequences of debt reductons, in the context of insolvency, death and the liquidaton of a deceased estate
- Authors: Simango, Samuel
- Date: 2014
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/54464 , vital:26567
- Description: The present research was conducted in an effort to address certain problems and a legal anomaly that is specifically related to the tax treatment of reduced debts stemming from the death or insolvency of natural persons in South Africa. At the beginning of 2013 the National Treasury enacted certain amendments to the debt reduction provisions of the Income Tax Act 58 of 1962 with the intention of streamlining the tax treatment of reduced debts and granting debt relief to financially distressed debtors. In spite of these recent amendments to the provisions of the Income Tax Act, there are certain problems and a legal anomaly which still currently relate to the tax consequences of reduced debts in South Africa. These problems and the legal anomaly are based on the failure of the recent amendments to successfully address debt reduction which arises in the context of the death and/or insolvency of natural persons. The objective of this research was therefore to analyse the tax consequences of reduced debts arising in the context of the death and the insolvency of natural persons and to explain how the problems and legal anomaly associated with these tax consequences can be rectified. The research design was qualitative within the framework of an interpretive paradigm. A mixed methodology approach was followed as identified in the Arthurs Report (1983), namely the interdisciplinary and the doctrinal methodologies. This approach encompassed two legal research methods namely the expository and legal reform research methods. The research explained the underlying nature of the tax consequences of reduced debts arising in the context of the death and the insolvency of natural persons and formulated specific reform measures aimed at remedying the problems and the legal anomaly that currently exist. Two amendments were proposed. It was proposed that the tax liability which arises when debts are reduced through the wills of deceased persons and the reduction of debts stemming from the insolvency of natural persons should be expressly excluded from falling within the ambit of the provisions which give rise to tax consequences whenever debt reduction takes place.
- Full Text:
- Authors: Simango, Samuel
- Date: 2014
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/54464 , vital:26567
- Description: The present research was conducted in an effort to address certain problems and a legal anomaly that is specifically related to the tax treatment of reduced debts stemming from the death or insolvency of natural persons in South Africa. At the beginning of 2013 the National Treasury enacted certain amendments to the debt reduction provisions of the Income Tax Act 58 of 1962 with the intention of streamlining the tax treatment of reduced debts and granting debt relief to financially distressed debtors. In spite of these recent amendments to the provisions of the Income Tax Act, there are certain problems and a legal anomaly which still currently relate to the tax consequences of reduced debts in South Africa. These problems and the legal anomaly are based on the failure of the recent amendments to successfully address debt reduction which arises in the context of the death and/or insolvency of natural persons. The objective of this research was therefore to analyse the tax consequences of reduced debts arising in the context of the death and the insolvency of natural persons and to explain how the problems and legal anomaly associated with these tax consequences can be rectified. The research design was qualitative within the framework of an interpretive paradigm. A mixed methodology approach was followed as identified in the Arthurs Report (1983), namely the interdisciplinary and the doctrinal methodologies. This approach encompassed two legal research methods namely the expository and legal reform research methods. The research explained the underlying nature of the tax consequences of reduced debts arising in the context of the death and the insolvency of natural persons and formulated specific reform measures aimed at remedying the problems and the legal anomaly that currently exist. Two amendments were proposed. It was proposed that the tax liability which arises when debts are reduced through the wills of deceased persons and the reduction of debts stemming from the insolvency of natural persons should be expressly excluded from falling within the ambit of the provisions which give rise to tax consequences whenever debt reduction takes place.
- Full Text:
A critical discourse analysis (CDA) of the contesting discourses articulated by the ANC and the news media in the City Press coverage of The Spear
- Authors: Egglestone, Tia Ashleigh
- Date: 2014
- Subjects: Murray, Brett , African National Congress , Mass media -- Political aspects -- South Africa , Press and politics -- South Africa , Freedom of the press -- South Africa , Mass media policy -- South Africa , Newspapers -- Objectivity , Critical discourse analysis , South Africa -- Politics and government -- 1994-
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3526 , http://hdl.handle.net/10962/d1012975
- Description: This research focuses on the controversy surrounding the exhibition and media publication of Brett Murray’s painting, The Spear of the Nation (May 2012). It takes the form of a qualitative Critical Discourse Analysis (CDA), underpinned by Fairclough’s (1995) three-dimensional approach, to investigate how the contesting discourses articulated by the ruling political party (the ANC) and the news media have been negotiated in the City Press coverage in response to the painting. While the contestation was fought ostensibly on constitutional grounds, it arguably serves as an illustrative moment of the deeply ideological debate occurring in South Africa between the government and the national media industry regarding media diversity, transformation and democracy. It points to the lines of fracture in the broader political and social space. Informed by Foucault’s conceptualisation of discourse and the role of power in the production of knowledge and ‘truth’, this study aims to expose the discourses articulated and contested in order to make inferences about the various ‘truths’ the ANC and the media make of the democratic role of the press in a contemporary South Africa. The sample consists of five reports intended to represent the media’s responses and four articles that prominently articulate the ANC’s responses. The analysis, which draws on strategies from within critical linguists and media studies, is confined to these nine purposively sampled from the City Press online newspaper texts published between 13 May 2012 and 13 June 2012. Findings suggest the ANC legitimise expectations for the media to engage in a collaborative role in order to serve the ‘national interest’. Conversely, the media advocate for a monitorial press to justify serving the ‘public interest’. This research is envisioned to be valuable for both sets of stakeholders in developing richer understandings relevant to issues of any regulation to be debated. It forms part of a larger project on Media Policy and Democracy which seeks to contribute to media diversity and transformation, and to develop the quality of democracy in South Africa.
- Full Text:
- Authors: Egglestone, Tia Ashleigh
- Date: 2014
- Subjects: Murray, Brett , African National Congress , Mass media -- Political aspects -- South Africa , Press and politics -- South Africa , Freedom of the press -- South Africa , Mass media policy -- South Africa , Newspapers -- Objectivity , Critical discourse analysis , South Africa -- Politics and government -- 1994-
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3526 , http://hdl.handle.net/10962/d1012975
- Description: This research focuses on the controversy surrounding the exhibition and media publication of Brett Murray’s painting, The Spear of the Nation (May 2012). It takes the form of a qualitative Critical Discourse Analysis (CDA), underpinned by Fairclough’s (1995) three-dimensional approach, to investigate how the contesting discourses articulated by the ruling political party (the ANC) and the news media have been negotiated in the City Press coverage in response to the painting. While the contestation was fought ostensibly on constitutional grounds, it arguably serves as an illustrative moment of the deeply ideological debate occurring in South Africa between the government and the national media industry regarding media diversity, transformation and democracy. It points to the lines of fracture in the broader political and social space. Informed by Foucault’s conceptualisation of discourse and the role of power in the production of knowledge and ‘truth’, this study aims to expose the discourses articulated and contested in order to make inferences about the various ‘truths’ the ANC and the media make of the democratic role of the press in a contemporary South Africa. The sample consists of five reports intended to represent the media’s responses and four articles that prominently articulate the ANC’s responses. The analysis, which draws on strategies from within critical linguists and media studies, is confined to these nine purposively sampled from the City Press online newspaper texts published between 13 May 2012 and 13 June 2012. Findings suggest the ANC legitimise expectations for the media to engage in a collaborative role in order to serve the ‘national interest’. Conversely, the media advocate for a monitorial press to justify serving the ‘public interest’. This research is envisioned to be valuable for both sets of stakeholders in developing richer understandings relevant to issues of any regulation to be debated. It forms part of a larger project on Media Policy and Democracy which seeks to contribute to media diversity and transformation, and to develop the quality of democracy in South Africa.
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A critical history of the rise and fall of the first ever independently owned Matabeleland publication in Zimbabwe : the case of The Southern Star
- Authors: Moyo, Chelesani
- Date: 2014
- Subjects: Southern Star (Zimbabwe) , Matabeleland (Zimbabwe) -- History -- Autonomy and independence movements , Mass media and nationalism -- Zimbabwe , Mass media -- Political aspects -- Zimbabwe , Press and politics -- Zimbabwe , Newspaper publishing -- Management , Newspapers -- Marketing
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3530 , http://hdl.handle.net/10962/d1013273
- Description: This research is premised on the understanding that alternative forms of media emerge to deal with specific ideological projects and, as such, must be seen as satisfying a specific need at a specific point in time. Using the case of a weekly newspaper, The Southern Star which was in circulation from January 2012 to June 2012, this study sought to understand the factors that led to the establishment of the newspaper, what it sought to achieve, how it went about putting that into practice, its message in relation to debates emanating from the ‘Matabeleland Question’ and also the factors that led to the its collapse. In order to address my research questions, I adopted a two stage research design qualitative content analysis and semi structured in depth interviews. In locating the study within the qualitative epistemic understanding of research, it was clear from the qualitative content analysis of 13 editions of the publication and in depth interviews held with 15 respondents that the newspaper was set up with the aim of serving a marginalised section of the population (in this instance the Ndebele) by providing them with a platform to articulate issues affecting them. It also sought to ‘speak’ the ‘unspoken’ within the mainstream media by focusing on Matabeleland identity politics. It achieved this by creating content around the Gukurahundi genocide, Matabeleland development, Matabeleland history and Matabeleland heroes. The newspaper also sought to emancipate the people from the South by advocated for social, cultural, economic and political justice as a resolution to the ‘Matabeleland Question’. However, the newspaper failed to sustain operations due to lack of advertising revenue. As a result of the constraining political environment in which the newspaper operated, potential advertisers were afraid of placing advertisements in the newspaper because of the nature of the content produced, which in view of Zimbabwe’s rival ethnic history, could easily be labelled ethnically divisive. Also, being a new player in the market worked to their disadvantage as prospective advertisers opted to place their adverts in “tried and tested” publications (Zimpapers and Alpha Media Holdings). Additionally, because of poor management, roles were not clearly defined and hence the newspaper failed to operate as a business enterprise. As noted during interviews with junior reporters, there was little or no experience at management level. The paper lacked a coordinated circulation strategy and from inception, was never officially launched, which resulted in the failure to reach significant audiences.
- Full Text:
- Authors: Moyo, Chelesani
- Date: 2014
- Subjects: Southern Star (Zimbabwe) , Matabeleland (Zimbabwe) -- History -- Autonomy and independence movements , Mass media and nationalism -- Zimbabwe , Mass media -- Political aspects -- Zimbabwe , Press and politics -- Zimbabwe , Newspaper publishing -- Management , Newspapers -- Marketing
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3530 , http://hdl.handle.net/10962/d1013273
- Description: This research is premised on the understanding that alternative forms of media emerge to deal with specific ideological projects and, as such, must be seen as satisfying a specific need at a specific point in time. Using the case of a weekly newspaper, The Southern Star which was in circulation from January 2012 to June 2012, this study sought to understand the factors that led to the establishment of the newspaper, what it sought to achieve, how it went about putting that into practice, its message in relation to debates emanating from the ‘Matabeleland Question’ and also the factors that led to the its collapse. In order to address my research questions, I adopted a two stage research design qualitative content analysis and semi structured in depth interviews. In locating the study within the qualitative epistemic understanding of research, it was clear from the qualitative content analysis of 13 editions of the publication and in depth interviews held with 15 respondents that the newspaper was set up with the aim of serving a marginalised section of the population (in this instance the Ndebele) by providing them with a platform to articulate issues affecting them. It also sought to ‘speak’ the ‘unspoken’ within the mainstream media by focusing on Matabeleland identity politics. It achieved this by creating content around the Gukurahundi genocide, Matabeleland development, Matabeleland history and Matabeleland heroes. The newspaper also sought to emancipate the people from the South by advocated for social, cultural, economic and political justice as a resolution to the ‘Matabeleland Question’. However, the newspaper failed to sustain operations due to lack of advertising revenue. As a result of the constraining political environment in which the newspaper operated, potential advertisers were afraid of placing advertisements in the newspaper because of the nature of the content produced, which in view of Zimbabwe’s rival ethnic history, could easily be labelled ethnically divisive. Also, being a new player in the market worked to their disadvantage as prospective advertisers opted to place their adverts in “tried and tested” publications (Zimpapers and Alpha Media Holdings). Additionally, because of poor management, roles were not clearly defined and hence the newspaper failed to operate as a business enterprise. As noted during interviews with junior reporters, there was little or no experience at management level. The paper lacked a coordinated circulation strategy and from inception, was never officially launched, which resulted in the failure to reach significant audiences.
- Full Text:
A discussion and comparison of company legislation and tax legislation in South Africa, in relation to amalgamations and mergers
- Authors: Sloane, Justin
- Date: 2014
- Subjects: Corporation law -- South Africa , Taxation -- Law and legislation -- South Africa , Consolidation and merger of corporations -- South Africa , Income tax -- South Africa , Capital gains tax -- South Africa , Value-added tax -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:908 , http://hdl.handle.net/10962/d1013028
- Description: In his 2012 Budget Review, the Minister of Finance, Pravin Gordhan acknowledged that the introduction of the "new" Companies Act had given rise to certain anomalies in relation to tax and subsequently announced that the South African government would undertake to review the nature of company mergers, acquisitions and other restructurings with the view of possibly amending the Income Tax Act and/or the "new" Companies Act, to bring the two legislations in line with one another. These anomalies give rise to the present research. The literature reviewed in the present research revealed and identified the inconsistencies that exist between the "new" Companies Act, 71 of 2008 and the Income Tax Act, 58 of 1962, specifically the inconsistencies that exist in respect of the newly introduced amalgamation or merger provisions as set out in the "new" Companies Act. Moreover, this research was undertaken to identify the potential tax implications insofar as they relate to amalgamation transactions and, in particular, the potential tax implications where such transactions, because of the anomalies, fall outside the ambit section 44 of the Income Tax Act, which would in normal circumstances provide for tax "rollover relief". In this regard, the present research identified the possible income tax, capital gains tax, value-added tax, transfer duty tax and securities transfer tax affected by an amalgamation transaction, on the assumption that the "rollover relief" in section 44 of the Income Tax Act does not apply.
- Full Text:
- Authors: Sloane, Justin
- Date: 2014
- Subjects: Corporation law -- South Africa , Taxation -- Law and legislation -- South Africa , Consolidation and merger of corporations -- South Africa , Income tax -- South Africa , Capital gains tax -- South Africa , Value-added tax -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:908 , http://hdl.handle.net/10962/d1013028
- Description: In his 2012 Budget Review, the Minister of Finance, Pravin Gordhan acknowledged that the introduction of the "new" Companies Act had given rise to certain anomalies in relation to tax and subsequently announced that the South African government would undertake to review the nature of company mergers, acquisitions and other restructurings with the view of possibly amending the Income Tax Act and/or the "new" Companies Act, to bring the two legislations in line with one another. These anomalies give rise to the present research. The literature reviewed in the present research revealed and identified the inconsistencies that exist between the "new" Companies Act, 71 of 2008 and the Income Tax Act, 58 of 1962, specifically the inconsistencies that exist in respect of the newly introduced amalgamation or merger provisions as set out in the "new" Companies Act. Moreover, this research was undertaken to identify the potential tax implications insofar as they relate to amalgamation transactions and, in particular, the potential tax implications where such transactions, because of the anomalies, fall outside the ambit section 44 of the Income Tax Act, which would in normal circumstances provide for tax "rollover relief". In this regard, the present research identified the possible income tax, capital gains tax, value-added tax, transfer duty tax and securities transfer tax affected by an amalgamation transaction, on the assumption that the "rollover relief" in section 44 of the Income Tax Act does not apply.
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A field investigation into the impact of task demands on worker responses in the South African forestry silviculture sector
- Authors: Parker, Rhiannon Jennifer
- Date: 2014
- Subjects: Forests and forestry -- South Africa -- KwaZulu-Natal , Blue collar workers -- South Africa -- KwaZulu-Natal , Manual work -- South Africa -- KwaZulu-Natal , Work -- Physiological aspects , Human mechanics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5157 , http://hdl.handle.net/10962/d1015645
- Description: Background: In South Africa, limited research has focused on the task demands and workers responses associated with forestry silviculture work, particularly pitting and planting. The methods currently in use are manual, but despite our lack of understanding of the existing demands, advances in forestry engineering have resulted in an introduction of semi-mechanised versions of these tasks. This project aimed to compare the task demands of silviculture tasks using the current manual techniques and the more modern, semi-mechanised techniques. Methods: A holistic investigation focused on the worker characteristics of a sample of black male pitters and black female planters from the Kwa-Zulu Natal forestry industry, as well as biomechanical (spinal kinematics and L5/S1 forces), physiological (heart rate, oxygen consumption and energy expenditure) and psychophysical (ratings of perceived exertion and body discomfort) responses associated with manual and semi-mechanised pitting and planting. Results: The pitting task saw significant improvements in the spinal kinematic measures as a result of the increased mechanisation, with eight of the 16 recorded variables decreasing to a lower level of risk classification. Physiologically, the manual task was associated with a mean heart rate of 157 bt.min⁻¹ and absolute energy expenditure of 11.27 kcal.min⁻¹, which were not found to be significantly different to the values of 143 bt.min⁻¹ and 9.8 kcal.min⁻¹ recorded during the semi-mechanised technique. Psychophysical responses indicated that the workers perceived manual pitting to be more physically demanding than the semi-mechanised method. The manual and semi-mechanised planting tasks were, in general, found to be acceptable from a spinal kinematics perspective, with the majority of variables classified as low risk. However, the maximum sagittal angle was reduced by more than 20 degrees as a result of the new equipment. The physiological and psychophysical demands associated with manual planting were found to be within acceptable limits. Conclusion: In terms of pitting, it can tentatively be concluded that the semi-mechanised technique is better than the manual one, based on the biomechanical and psychophysical findings, however physiological demands require further investigation. When considering the planting techniques, the semi-mechanised method showed a slight improvement from the biomechanical perspective, but further physiological and psychophysical investigations are needed.
- Full Text:
- Authors: Parker, Rhiannon Jennifer
- Date: 2014
- Subjects: Forests and forestry -- South Africa -- KwaZulu-Natal , Blue collar workers -- South Africa -- KwaZulu-Natal , Manual work -- South Africa -- KwaZulu-Natal , Work -- Physiological aspects , Human mechanics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5157 , http://hdl.handle.net/10962/d1015645
- Description: Background: In South Africa, limited research has focused on the task demands and workers responses associated with forestry silviculture work, particularly pitting and planting. The methods currently in use are manual, but despite our lack of understanding of the existing demands, advances in forestry engineering have resulted in an introduction of semi-mechanised versions of these tasks. This project aimed to compare the task demands of silviculture tasks using the current manual techniques and the more modern, semi-mechanised techniques. Methods: A holistic investigation focused on the worker characteristics of a sample of black male pitters and black female planters from the Kwa-Zulu Natal forestry industry, as well as biomechanical (spinal kinematics and L5/S1 forces), physiological (heart rate, oxygen consumption and energy expenditure) and psychophysical (ratings of perceived exertion and body discomfort) responses associated with manual and semi-mechanised pitting and planting. Results: The pitting task saw significant improvements in the spinal kinematic measures as a result of the increased mechanisation, with eight of the 16 recorded variables decreasing to a lower level of risk classification. Physiologically, the manual task was associated with a mean heart rate of 157 bt.min⁻¹ and absolute energy expenditure of 11.27 kcal.min⁻¹, which were not found to be significantly different to the values of 143 bt.min⁻¹ and 9.8 kcal.min⁻¹ recorded during the semi-mechanised technique. Psychophysical responses indicated that the workers perceived manual pitting to be more physically demanding than the semi-mechanised method. The manual and semi-mechanised planting tasks were, in general, found to be acceptable from a spinal kinematics perspective, with the majority of variables classified as low risk. However, the maximum sagittal angle was reduced by more than 20 degrees as a result of the new equipment. The physiological and psychophysical demands associated with manual planting were found to be within acceptable limits. Conclusion: In terms of pitting, it can tentatively be concluded that the semi-mechanised technique is better than the manual one, based on the biomechanical and psychophysical findings, however physiological demands require further investigation. When considering the planting techniques, the semi-mechanised method showed a slight improvement from the biomechanical perspective, but further physiological and psychophysical investigations are needed.
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A Flexible Approach for the Application of Immersive Audio to an Installation Performance:
- Gurdan, Robby, Foss, Richard
- Authors: Gurdan, Robby , Foss, Richard
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426732 , vital:72387 , https://patentimages.storage.googleapis.com/28/4a/94/1113bd7074ad90/US8862755.pdf /
- Description: An apparatus for modifying a command message (CMD) received from a source apparatus to control a target device parameter of a target apparatus within a digital multimedia network, wherein a hierarchical parameter address (HPA) or a parameter value contained in said command message (CMD) is changed according to at least one change script to provide a modified command message (CMD′).
- Full Text:
- Authors: Gurdan, Robby , Foss, Richard
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426732 , vital:72387 , https://patentimages.storage.googleapis.com/28/4a/94/1113bd7074ad90/US8862755.pdf /
- Description: An apparatus for modifying a command message (CMD) received from a source apparatus to control a target device parameter of a target apparatus within a digital multimedia network, wherein a hierarchical parameter address (HPA) or a parameter value contained in said command message (CMD) is changed according to at least one change script to provide a modified command message (CMD′).
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A formalised ontology for network attack classification
- Authors: Van Heerden, Renier Pelser
- Date: 2014
- Subjects: Computer networks -- Security measures Computer security Computer crimes -- Investigation Computer crimes -- Prevention
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4691 , http://hdl.handle.net/10962/d1011603
- Description: One of the most popular attack vectors against computers are their network connections. Attacks on computers through their networks are commonplace and have various levels of complexity. This research formally describes network-based computer attacks in the form of a story, formally and within an ontology. The ontology categorises network attacks where attack scenarios are the focal class. This class consists of: Denial-of- Service, Industrial Espionage, Web Defacement, Unauthorised Data Access, Financial Theft, Industrial Sabotage, Cyber-Warfare, Resource Theft, System Compromise, and Runaway Malware. This ontology was developed by building a taxonomy and a temporal network attack model. Network attack instances (also know as individuals) are classified according to their respective attack scenarios, with the use of an automated reasoner within the ontology. The automated reasoner deductions are verified formally; and via the automated reasoner, a relaxed set of scenarios is determined, which is relevant in a near real-time environment. A prototype system (called Aeneas) was developed to classify network-based attacks. Aeneas integrates the sensors into a detection system that can classify network attacks in a near real-time environment. To verify the ontology and the prototype Aeneas, a virtual test bed was developed in which network-based attacks were generated to verify the detection system. Aeneas was able to detect incoming attacks and classify them according to their scenario. The novel part of this research is the attack scenarios that are described in the form of a story, as well as formally and in an ontology. The ontology is used in a novel way to determine to which class attack instances belong and how the network attack ontology is affected in a near real-time environment.
- Full Text:
- Authors: Van Heerden, Renier Pelser
- Date: 2014
- Subjects: Computer networks -- Security measures Computer security Computer crimes -- Investigation Computer crimes -- Prevention
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4691 , http://hdl.handle.net/10962/d1011603
- Description: One of the most popular attack vectors against computers are their network connections. Attacks on computers through their networks are commonplace and have various levels of complexity. This research formally describes network-based computer attacks in the form of a story, formally and within an ontology. The ontology categorises network attacks where attack scenarios are the focal class. This class consists of: Denial-of- Service, Industrial Espionage, Web Defacement, Unauthorised Data Access, Financial Theft, Industrial Sabotage, Cyber-Warfare, Resource Theft, System Compromise, and Runaway Malware. This ontology was developed by building a taxonomy and a temporal network attack model. Network attack instances (also know as individuals) are classified according to their respective attack scenarios, with the use of an automated reasoner within the ontology. The automated reasoner deductions are verified formally; and via the automated reasoner, a relaxed set of scenarios is determined, which is relevant in a near real-time environment. A prototype system (called Aeneas) was developed to classify network-based attacks. Aeneas integrates the sensors into a detection system that can classify network attacks in a near real-time environment. To verify the ontology and the prototype Aeneas, a virtual test bed was developed in which network-based attacks were generated to verify the detection system. Aeneas was able to detect incoming attacks and classify them according to their scenario. The novel part of this research is the attack scenarios that are described in the form of a story, as well as formally and in an ontology. The ontology is used in a novel way to determine to which class attack instances belong and how the network attack ontology is affected in a near real-time environment.
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A framework for high speed lexical classification of malicious URLs
- Authors: Egan, Shaun Peter
- Date: 2014
- Subjects: Internet -- Security measures -- Research , Uniform Resource Identifiers -- Security measures -- Research , Neural networks (Computer science) -- Research , Computer security -- Research , Computer crimes -- Prevention , Phishing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4696 , http://hdl.handle.net/10962/d1011933 , Internet -- Security measures -- Research , Uniform Resource Identifiers -- Security measures -- Research , Neural networks (Computer science) -- Research , Computer security -- Research , Computer crimes -- Prevention , Phishing
- Description: Phishing attacks employ social engineering to target end-users, with the goal of stealing identifying or sensitive information. This information is used in activities such as identity theft or financial fraud. During a phishing campaign, attackers distribute URLs which; along with false information, point to fraudulent resources in an attempt to deceive users into requesting the resource. These URLs are made obscure through the use of several techniques which make automated detection difficult. Current methods used to detect malicious URLs face multiple problems which attackers use to their advantage. These problems include: the time required to react to new attacks; shifts in trends in URL obfuscation and usability problems caused by the latency incurred by the lookups required by these approaches. A new method of identifying malicious URLs using Artificial Neural Networks (ANNs) has been shown to be effective by several authors. The simple method of classification performed by ANNs result in very high classification speeds with little impact on usability. Samples used for the training, validation and testing of these ANNs are gathered from Phishtank and Open Directory. Words selected from the different sections of the samples are used to create a `Bag-of-Words (BOW)' which is used as a binary input vector indicating the presence of a word for a given sample. Twenty additional features which measure lexical attributes of the sample are used to increase classification accuracy. A framework that is capable of generating these classifiers in an automated fashion is implemented. These classifiers are automatically stored on a remote update distribution service which has been built to supply updates to classifier implementations. An example browser plugin is created and uses ANNs provided by this service. It is both capable of classifying URLs requested by a user in real time and is able to block these requests. The framework is tested in terms of training time and classification accuracy. Classification speed and the effectiveness of compression algorithms on the data required to distribute updates is tested. It is concluded that it is possible to generate these ANNs in a frequent fashion, and in a method that is small enough to distribute easily. It is also shown that classifications are made at high-speed with high-accuracy, resulting in little impact on usability.
- Full Text:
- Authors: Egan, Shaun Peter
- Date: 2014
- Subjects: Internet -- Security measures -- Research , Uniform Resource Identifiers -- Security measures -- Research , Neural networks (Computer science) -- Research , Computer security -- Research , Computer crimes -- Prevention , Phishing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4696 , http://hdl.handle.net/10962/d1011933 , Internet -- Security measures -- Research , Uniform Resource Identifiers -- Security measures -- Research , Neural networks (Computer science) -- Research , Computer security -- Research , Computer crimes -- Prevention , Phishing
- Description: Phishing attacks employ social engineering to target end-users, with the goal of stealing identifying or sensitive information. This information is used in activities such as identity theft or financial fraud. During a phishing campaign, attackers distribute URLs which; along with false information, point to fraudulent resources in an attempt to deceive users into requesting the resource. These URLs are made obscure through the use of several techniques which make automated detection difficult. Current methods used to detect malicious URLs face multiple problems which attackers use to their advantage. These problems include: the time required to react to new attacks; shifts in trends in URL obfuscation and usability problems caused by the latency incurred by the lookups required by these approaches. A new method of identifying malicious URLs using Artificial Neural Networks (ANNs) has been shown to be effective by several authors. The simple method of classification performed by ANNs result in very high classification speeds with little impact on usability. Samples used for the training, validation and testing of these ANNs are gathered from Phishtank and Open Directory. Words selected from the different sections of the samples are used to create a `Bag-of-Words (BOW)' which is used as a binary input vector indicating the presence of a word for a given sample. Twenty additional features which measure lexical attributes of the sample are used to increase classification accuracy. A framework that is capable of generating these classifiers in an automated fashion is implemented. These classifiers are automatically stored on a remote update distribution service which has been built to supply updates to classifier implementations. An example browser plugin is created and uses ANNs provided by this service. It is both capable of classifying URLs requested by a user in real time and is able to block these requests. The framework is tested in terms of training time and classification accuracy. Classification speed and the effectiveness of compression algorithms on the data required to distribute updates is tested. It is concluded that it is possible to generate these ANNs in a frequent fashion, and in a method that is small enough to distribute easily. It is also shown that classifications are made at high-speed with high-accuracy, resulting in little impact on usability.
- Full Text:
A geological, petrological and mineralogical study of the UG3 chromitite seam at Modikwa Platinum Mine : significance to exploration and PGE resources
- Authors: Machumele, Nkateko Jones
- Date: 2014
- Subjects: Modikwa Platinum Mine (South Africa) , Chromite -- South Africa -- Limpopo , Geology -- South Africa -- Limpopo , Petrology -- South Africa -- Limpopo , Mineralogy -- South Africa -- Limpopo , Platinum mines and mining -- South Africa -- Limpopo
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5074 , http://hdl.handle.net/10962/d1013553
- Description: The UG3 at Modikwa Platinum Mine occurs as a platiniferous, planar chromitite seam. It is stratigraphically located in the Upper Critical Zone of the Eastern Bushveld Complex. Field work study comprise of underground mapping, sampling, surface mapping, borehole core logging, microprobing and microscopic investigations carried out at the Rhodes University. The UG3 at the Modikwa Platinum Mine is about 22cm thick chromitite seam underlain by a white fine grained anorthosite and overlain by a brown medium grained feldspathic pyroxenite. It is an incomplete cyclic unit consisting of chromite and feldspathic pyroxenite. The UG3 reef at the Modikwa Platinum Mine lease area represents a Platinum Group Metal resource of 300 million tons of ore at an in situ grade of 2.5g/t. Under the current market conditions the UG3 reef remains unprofitable to mine in an underground operation due to the operational cost involved. However, it has been illustrated that the UG3 chromitite seam can increase profit margins in an open pit operation provided it is mined together with the economic UG2 chromitite seam. The extraction of the UG3 as ore in the four Modikwa UG2 open pits would result in a combined operating cash profit of R330 million. The UG3 chromitite seam is platiniferous. The platinum-group minerals (PGM) range in size from less than 10μm to about 70μm. The PGMs are associated with sulphides and are both located in the interstitial silicates and are concentrated in the chromitite seam. The PGMs show a strong preference to contact boundaries of the silicate grains, the chromite grains and the sulphide phases. In some instances, they are enclosed within the chromite grains in association with sulphides. The general sulphide assemblage comprises pentlandite and chalcopyrite whereas, the PGMs assemblage comprises cooperite, ferroplatinum, laurite, FeRhS and PtRhS.
- Full Text:
- Authors: Machumele, Nkateko Jones
- Date: 2014
- Subjects: Modikwa Platinum Mine (South Africa) , Chromite -- South Africa -- Limpopo , Geology -- South Africa -- Limpopo , Petrology -- South Africa -- Limpopo , Mineralogy -- South Africa -- Limpopo , Platinum mines and mining -- South Africa -- Limpopo
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5074 , http://hdl.handle.net/10962/d1013553
- Description: The UG3 at Modikwa Platinum Mine occurs as a platiniferous, planar chromitite seam. It is stratigraphically located in the Upper Critical Zone of the Eastern Bushveld Complex. Field work study comprise of underground mapping, sampling, surface mapping, borehole core logging, microprobing and microscopic investigations carried out at the Rhodes University. The UG3 at the Modikwa Platinum Mine is about 22cm thick chromitite seam underlain by a white fine grained anorthosite and overlain by a brown medium grained feldspathic pyroxenite. It is an incomplete cyclic unit consisting of chromite and feldspathic pyroxenite. The UG3 reef at the Modikwa Platinum Mine lease area represents a Platinum Group Metal resource of 300 million tons of ore at an in situ grade of 2.5g/t. Under the current market conditions the UG3 reef remains unprofitable to mine in an underground operation due to the operational cost involved. However, it has been illustrated that the UG3 chromitite seam can increase profit margins in an open pit operation provided it is mined together with the economic UG2 chromitite seam. The extraction of the UG3 as ore in the four Modikwa UG2 open pits would result in a combined operating cash profit of R330 million. The UG3 chromitite seam is platiniferous. The platinum-group minerals (PGM) range in size from less than 10μm to about 70μm. The PGMs are associated with sulphides and are both located in the interstitial silicates and are concentrated in the chromitite seam. The PGMs show a strong preference to contact boundaries of the silicate grains, the chromite grains and the sulphide phases. In some instances, they are enclosed within the chromite grains in association with sulphides. The general sulphide assemblage comprises pentlandite and chalcopyrite whereas, the PGMs assemblage comprises cooperite, ferroplatinum, laurite, FeRhS and PtRhS.
- Full Text:
A goal-setting intervention with motocross racers : a case study investigating the effects of an intervention on perceived motivation, confidence, and self-efficacy
- Authors: Fleming, Tracey Laura
- Date: 2014
- Subjects: Motocross -- Psychological aspects -- Research , Motorcyclists -- Psychological aspects -- Research , Goal (Psychology) -- Research , Competition (Psychology) -- Research , Motivation (Psychology) -- Case studies , Confidence -- Case studies , Self-efficacy -- Case studies , Sports -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3224 , http://hdl.handle.net/10962/d1012996
- Description: This study aimed to investigate the effects that a specifically tailored goal-setting program would have on two motocross racers in terms of their self-efficacy and motivation, as well as the process of designing this intervention. This case-study approach involved a mixed methods approach, consisting of pre-intervention and post-intervention assessments, interviews, and performance profiles. The tools used include Vealey’s (1986) Competitive Orientation Inventory (COI), Gill and Deeter’s (1988) Sport Orientation Questionnaire (SOQ), performance profiles, and semi-structured interviews. The goal-setting intervention lasted a total of five weeks. The results from the preintervention and post-intervention assessments were compared to determine whether any changes in motivation or self-efficacy occurred during the intervention. For the first participant, significant changes in both motivation and self-efficacy were present in addition to significant changes in competitive orientation. For the second participant, there were no significant changes in either motivation or self-efficacy. However, for the second participant there was also no change in competitive orientation. Findings suggest that the focus and competitive orientation of an athlete have a significant influence on the types of goals set, and consequently on positive changes in motivation, confidence, and self-efficacy. The influence of the competitive orientation in athletes also highlighted the importance of attaining a balance between performance and outcome goal-related activities. It was also discovered through qualitative assessment that this program is suitable for particular groups of athletes such as those who are injured, display an external locus of causality or are otherwise not performing at their prime.
- Full Text:
- Authors: Fleming, Tracey Laura
- Date: 2014
- Subjects: Motocross -- Psychological aspects -- Research , Motorcyclists -- Psychological aspects -- Research , Goal (Psychology) -- Research , Competition (Psychology) -- Research , Motivation (Psychology) -- Case studies , Confidence -- Case studies , Self-efficacy -- Case studies , Sports -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3224 , http://hdl.handle.net/10962/d1012996
- Description: This study aimed to investigate the effects that a specifically tailored goal-setting program would have on two motocross racers in terms of their self-efficacy and motivation, as well as the process of designing this intervention. This case-study approach involved a mixed methods approach, consisting of pre-intervention and post-intervention assessments, interviews, and performance profiles. The tools used include Vealey’s (1986) Competitive Orientation Inventory (COI), Gill and Deeter’s (1988) Sport Orientation Questionnaire (SOQ), performance profiles, and semi-structured interviews. The goal-setting intervention lasted a total of five weeks. The results from the preintervention and post-intervention assessments were compared to determine whether any changes in motivation or self-efficacy occurred during the intervention. For the first participant, significant changes in both motivation and self-efficacy were present in addition to significant changes in competitive orientation. For the second participant, there were no significant changes in either motivation or self-efficacy. However, for the second participant there was also no change in competitive orientation. Findings suggest that the focus and competitive orientation of an athlete have a significant influence on the types of goals set, and consequently on positive changes in motivation, confidence, and self-efficacy. The influence of the competitive orientation in athletes also highlighted the importance of attaining a balance between performance and outcome goal-related activities. It was also discovered through qualitative assessment that this program is suitable for particular groups of athletes such as those who are injured, display an external locus of causality or are otherwise not performing at their prime.
- Full Text:
A lignocellulolytic enzyme system for fruit waste degradation : commercial enzyme mixture synergy and bioreactor design
- Authors: Gama, Repson
- Date: 2014
- Subjects: Enzymes -- Biotechnology , Enzymes -- Industrial applications , Lignocellulose -- Biodegradation , Biomass energy , Biomass conversion , Biochemical engineering , Agricultural wastes as fuel
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4114 , http://hdl.handle.net/10962/d1013073
- Description: Studies into sources of alternative liquid transport fuel energy have identified agro-industrial wastes, which are lignocellulosic in nature, as a potential feedstock for biofuel production against the background of depleting nonrenewable fossil fuels. In South Africa, large quantities of apple and other fruit wastes, called pomace, are generated from fruit and juice industries. Apple pomace is a rich source of cellulose, pectin and hemicellulose, making it a potential target for utilisation as a lignocellulosic feedstock for biofuel and biorefinery chemical production. Lignocellulosic biomass is recalcitrant in nature and therefore its degradation requires the synergistic action of a number of enzymes such as cellulases, hemicellulases, pectinases and ligninases. Commercial enzyme cocktails, containing some of these enzymes, are available and can be used for apple pomace degradation. In this study, the degradation of apple pomace using commercial enzyme cocktails was investigated. The main focus was the optimisation of the release of sugar monomers that could potentially be used for biofuel and biorefinery chemical production. There is no or little information reported in literature on the enzymatic degradation of fruit waste using commercial enzyme mixtures. This study first focused on the characterisation of the substrate (apple pomace) and the commercial enzyme cocktails. Apple pomace was found to contain mainly glucose, galacturonic acid, arabinose, galactose, lignin and low amounts of xylose and fructose. Three commercial enzyme cocktails were initially selected: Biocip Membrane, Viscozyme L (from Aspergillus aculeatus) and Celluclast 1.5L (a Trichoderma reesei ATCC 26921 cellulase preparation). The selection of the enzymes was based on activities declared by the manufacturers, cost and local availability. The enzymes were screened based on their synergistic cooperation in the degradation of apple pomace and the main enzymes present in each cocktail. Viscozyme L and Celluclast 1.5L, in a 50:50 ratio, resulted in the best degree of synergy (1.6) compared to any other combination. The enzyme ratios were determined on Viscozyme L and Celluclast 1.5L based on the protein ratio. Enzyme activity was determined as glucose equivalents using the dinitrosalicylic acid (DNS) method. Sugar monomers were determined using Megazyme assay kits. There is limited information available on the enzymes present in the commercial enzyme cocktails. Therefore, the main enzymes present in Viscozyme L and Celluclast 1.5L were identified using different substrates, each targeted for a specific enzyme and activity. Characterisation of the enzyme mixtures revealed a large number of enzymes required for apple pomace degradation and these included cellulases, pectinases, xylanases, arabinases and mannanases in different proportions. Viscozyme L contained mainly pectinases and hemicellulases, while Celluclast 1.5L displayed largely cellulase and xylanase activity, hence the high degree of synergy reported. The temperature optimum was 50ºC for both enzyme mixtures and pH optima were observed at pH 5.0 and pH 3.0 for Viscozyme L and Celluclast 1.5L, respectively. At 37ºC and pH 5.0, the enzymes retained more that 90% activity after 15 days of incubation, allowing the enzymes to be used together with less energy input. The enzymes were further characterised by determining the effect of various compounds, such as alcohols, sugars, phenolic compounds and metal ions at various concentrations on the activity of the enzymes during apple pomace hydrolysis. Apart from lignin, which had almost no effect on enzyme activity, all the compounds caused inhibition of the enzymes to varying degrees. The most inhibitory compounds were some organic acids and metal ions, as well as cellobiose and xylobiose. Using the best ratio for Viscozyme L and Celluclast 1.5L (50:50) for the hydrolysis of apple pomace, it was observed that synergy was highest at the initial stages of hydrolysis and decreased over time, though the sugar concentration increased. The type of synergy for optimal apple pomace hydrolysis was found to be simultaneous. There was no synergy observed between Viscozyme L and Celluclast 1.5L with ligninases - laccase, lignin peroxidase and manganese peroxidase. Hydrolysing apple pomace with ligninases prior to addition of Viscozyme L and Celluclast 1.5L did not improve degradation of the substrate. Immobilisation of the enzyme mixtures on different supports was performed with the aim of increasing stability and enabling reuse of the enzymes. Immobilisation methods were selected based on the chemical properties of the supports, availability, cost and applicability on heterogeneous and insoluble substrate like apple pomace. These methods included crosslinked enzyme aggregates (CLEAs), immobilisation on various supports such as nylon mesh, nylon beads, sodium alginate beads, chitin and silica gel beads. The immobilisation strategies were unsuccessful, mainly due to the low percentage of immobilisation of the enzyme on the matrix and loss of activity of the immobilised enzyme. Free enzymes were therefore used for the remainder of the study. Hydrolysis conditions for apple pomace degradation were optimised using different temperatures and buffer systems in 1 L volumes mixed with compressed air. Hydrolysis at room temperature, using an unbuffered system, gave a better performance as compared to a buffered system. Reactors operated in batch mode performed better (4.2 g/L (75% yield) glucose and 16.8 g/L (75%) reducing sugar) than fed-batch reactors (3.2 g/L (66%) glucose and 14.6 g/L (72.7% yield) reducing sugar) over 100 h using Viscozyme L and Celluclast 1.5L. Supplementation of β- glucosidase activity in Viscozyme L and Celluclast 1.5L with Novozyme 188 resulted in a doubling of the amount of glucose released. The main products released from apple pomace hydrolysis were galacturonic acid, glucose and arabinose and low amounts of galactose and xylose. These products are potential raw materials for biofuel and biorefinery chemical production. An artificial neural network (ANN) model was successfully developed and used for predicting the optimum conditions for apple pomace hydrolysis using Celluclast 1.5L, Viscozyme L and Novozyme 188. Four main conditions that affect apple pomace hydrolysis were selected, namely temperature, initial pH, enzyme loading and substrate loading, which were taken as inputs. The glucose and reducing sugars released as a result of each treatment and their combinations were taken as outputs for 1–100 h. An ANN with 20, 20 and 6 neurons in the first, second and third hidden layers, respectively, was constructed. The performance and predictive ability of the ANN was good, with a R² of 0.99 and a small mean square error (MSE). New data was successfully predicted and simulated. Optimal hydrolysis conditions predicted by ANN for apple pomace hydrolysis were at 30% substrate (wet w/v) and an enzyme loading of 0.5 mg/g and 0.2 mg/mL of substrate for glucose and reducing sugar, respectively, giving sugar concentrations of 6.5 mg/mL and 28.9 mg/mL for glucose and reducing sugar, respectively. ANN showed that enzyme and substrate loadings were the most important factors for the hydrolysis of apple pomace.
- Full Text:
- Authors: Gama, Repson
- Date: 2014
- Subjects: Enzymes -- Biotechnology , Enzymes -- Industrial applications , Lignocellulose -- Biodegradation , Biomass energy , Biomass conversion , Biochemical engineering , Agricultural wastes as fuel
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4114 , http://hdl.handle.net/10962/d1013073
- Description: Studies into sources of alternative liquid transport fuel energy have identified agro-industrial wastes, which are lignocellulosic in nature, as a potential feedstock for biofuel production against the background of depleting nonrenewable fossil fuels. In South Africa, large quantities of apple and other fruit wastes, called pomace, are generated from fruit and juice industries. Apple pomace is a rich source of cellulose, pectin and hemicellulose, making it a potential target for utilisation as a lignocellulosic feedstock for biofuel and biorefinery chemical production. Lignocellulosic biomass is recalcitrant in nature and therefore its degradation requires the synergistic action of a number of enzymes such as cellulases, hemicellulases, pectinases and ligninases. Commercial enzyme cocktails, containing some of these enzymes, are available and can be used for apple pomace degradation. In this study, the degradation of apple pomace using commercial enzyme cocktails was investigated. The main focus was the optimisation of the release of sugar monomers that could potentially be used for biofuel and biorefinery chemical production. There is no or little information reported in literature on the enzymatic degradation of fruit waste using commercial enzyme mixtures. This study first focused on the characterisation of the substrate (apple pomace) and the commercial enzyme cocktails. Apple pomace was found to contain mainly glucose, galacturonic acid, arabinose, galactose, lignin and low amounts of xylose and fructose. Three commercial enzyme cocktails were initially selected: Biocip Membrane, Viscozyme L (from Aspergillus aculeatus) and Celluclast 1.5L (a Trichoderma reesei ATCC 26921 cellulase preparation). The selection of the enzymes was based on activities declared by the manufacturers, cost and local availability. The enzymes were screened based on their synergistic cooperation in the degradation of apple pomace and the main enzymes present in each cocktail. Viscozyme L and Celluclast 1.5L, in a 50:50 ratio, resulted in the best degree of synergy (1.6) compared to any other combination. The enzyme ratios were determined on Viscozyme L and Celluclast 1.5L based on the protein ratio. Enzyme activity was determined as glucose equivalents using the dinitrosalicylic acid (DNS) method. Sugar monomers were determined using Megazyme assay kits. There is limited information available on the enzymes present in the commercial enzyme cocktails. Therefore, the main enzymes present in Viscozyme L and Celluclast 1.5L were identified using different substrates, each targeted for a specific enzyme and activity. Characterisation of the enzyme mixtures revealed a large number of enzymes required for apple pomace degradation and these included cellulases, pectinases, xylanases, arabinases and mannanases in different proportions. Viscozyme L contained mainly pectinases and hemicellulases, while Celluclast 1.5L displayed largely cellulase and xylanase activity, hence the high degree of synergy reported. The temperature optimum was 50ºC for both enzyme mixtures and pH optima were observed at pH 5.0 and pH 3.0 for Viscozyme L and Celluclast 1.5L, respectively. At 37ºC and pH 5.0, the enzymes retained more that 90% activity after 15 days of incubation, allowing the enzymes to be used together with less energy input. The enzymes were further characterised by determining the effect of various compounds, such as alcohols, sugars, phenolic compounds and metal ions at various concentrations on the activity of the enzymes during apple pomace hydrolysis. Apart from lignin, which had almost no effect on enzyme activity, all the compounds caused inhibition of the enzymes to varying degrees. The most inhibitory compounds were some organic acids and metal ions, as well as cellobiose and xylobiose. Using the best ratio for Viscozyme L and Celluclast 1.5L (50:50) for the hydrolysis of apple pomace, it was observed that synergy was highest at the initial stages of hydrolysis and decreased over time, though the sugar concentration increased. The type of synergy for optimal apple pomace hydrolysis was found to be simultaneous. There was no synergy observed between Viscozyme L and Celluclast 1.5L with ligninases - laccase, lignin peroxidase and manganese peroxidase. Hydrolysing apple pomace with ligninases prior to addition of Viscozyme L and Celluclast 1.5L did not improve degradation of the substrate. Immobilisation of the enzyme mixtures on different supports was performed with the aim of increasing stability and enabling reuse of the enzymes. Immobilisation methods were selected based on the chemical properties of the supports, availability, cost and applicability on heterogeneous and insoluble substrate like apple pomace. These methods included crosslinked enzyme aggregates (CLEAs), immobilisation on various supports such as nylon mesh, nylon beads, sodium alginate beads, chitin and silica gel beads. The immobilisation strategies were unsuccessful, mainly due to the low percentage of immobilisation of the enzyme on the matrix and loss of activity of the immobilised enzyme. Free enzymes were therefore used for the remainder of the study. Hydrolysis conditions for apple pomace degradation were optimised using different temperatures and buffer systems in 1 L volumes mixed with compressed air. Hydrolysis at room temperature, using an unbuffered system, gave a better performance as compared to a buffered system. Reactors operated in batch mode performed better (4.2 g/L (75% yield) glucose and 16.8 g/L (75%) reducing sugar) than fed-batch reactors (3.2 g/L (66%) glucose and 14.6 g/L (72.7% yield) reducing sugar) over 100 h using Viscozyme L and Celluclast 1.5L. Supplementation of β- glucosidase activity in Viscozyme L and Celluclast 1.5L with Novozyme 188 resulted in a doubling of the amount of glucose released. The main products released from apple pomace hydrolysis were galacturonic acid, glucose and arabinose and low amounts of galactose and xylose. These products are potential raw materials for biofuel and biorefinery chemical production. An artificial neural network (ANN) model was successfully developed and used for predicting the optimum conditions for apple pomace hydrolysis using Celluclast 1.5L, Viscozyme L and Novozyme 188. Four main conditions that affect apple pomace hydrolysis were selected, namely temperature, initial pH, enzyme loading and substrate loading, which were taken as inputs. The glucose and reducing sugars released as a result of each treatment and their combinations were taken as outputs for 1–100 h. An ANN with 20, 20 and 6 neurons in the first, second and third hidden layers, respectively, was constructed. The performance and predictive ability of the ANN was good, with a R² of 0.99 and a small mean square error (MSE). New data was successfully predicted and simulated. Optimal hydrolysis conditions predicted by ANN for apple pomace hydrolysis were at 30% substrate (wet w/v) and an enzyme loading of 0.5 mg/g and 0.2 mg/mL of substrate for glucose and reducing sugar, respectively, giving sugar concentrations of 6.5 mg/mL and 28.9 mg/mL for glucose and reducing sugar, respectively. ANN showed that enzyme and substrate loadings were the most important factors for the hydrolysis of apple pomace.
- Full Text:
A mobile phone solution for ad-hoc hitch-hiking in South Africa
- Authors: Miteche, Sacha Patrick
- Date: 2014
- Subjects: Cell phones -- Information services , Cell phone users -- South Africa , Hitchhiking -- South Africa , Mobile communication systems -- Social aspects , Digital media -- South Africa , Information technology -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4702 , http://hdl.handle.net/10962/d1013340
- Description: The purpose of this study was to investigate the use of mobile phones in organizing ad-hoc vehicle ridesharing based on hitch-hiking trips involving private car drivers and commuters in South Africa. A study was conducted to learn how hitch-hiking trips are arranged in the urban and rural areas of the Eastern Cape. This involved carrying out interviews with hitch-hikers and participating in several trips. The study results provided the design specifications for a Dynamic Ridesharing System (DRS) tailor-made to the hitch-hiking culture of this context. The design of the DRS considered the delivery of the ad-hoc ridesharing service to the anticipated mobile phones owned by people who use hitch-hiking. The implementation of the system used the available open source solutions and guidelines under the Siyakhula Living Lab project, which promotes the use of Information and Communication Technology (ICT) in marginalized communities of South Africa. The developed prototype was tested in both the simulated and live environments, then followed by usability tests to establish the viability of the system. The results from the tests indicate an initial breakthrough in the process of modernizing the ad-hoc ridesharing of hitch-hiking which is used by a section of people in the urban and rural areas of South Africa.
- Full Text:
- Authors: Miteche, Sacha Patrick
- Date: 2014
- Subjects: Cell phones -- Information services , Cell phone users -- South Africa , Hitchhiking -- South Africa , Mobile communication systems -- Social aspects , Digital media -- South Africa , Information technology -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4702 , http://hdl.handle.net/10962/d1013340
- Description: The purpose of this study was to investigate the use of mobile phones in organizing ad-hoc vehicle ridesharing based on hitch-hiking trips involving private car drivers and commuters in South Africa. A study was conducted to learn how hitch-hiking trips are arranged in the urban and rural areas of the Eastern Cape. This involved carrying out interviews with hitch-hikers and participating in several trips. The study results provided the design specifications for a Dynamic Ridesharing System (DRS) tailor-made to the hitch-hiking culture of this context. The design of the DRS considered the delivery of the ad-hoc ridesharing service to the anticipated mobile phones owned by people who use hitch-hiking. The implementation of the system used the available open source solutions and guidelines under the Siyakhula Living Lab project, which promotes the use of Information and Communication Technology (ICT) in marginalized communities of South Africa. The developed prototype was tested in both the simulated and live environments, then followed by usability tests to establish the viability of the system. The results from the tests indicate an initial breakthrough in the process of modernizing the ad-hoc ridesharing of hitch-hiking which is used by a section of people in the urban and rural areas of South Africa.
- Full Text:
A needs-ICTD strategy alignment framework foundation for the measurement of ICTD impact
- Authors: Baduza, Gugulethu Qhawekazi
- Date: 2014
- Subjects: Siyakhula Living Lab SAP Research Needs assessment -- Information technology -- Social aspects -- South Africa -- Case studies Information technology -- South Africa -- Management -- Case studies Information technology -- Social aspects -- South Africa Rural development -- Economic aspects -- South Africa Rural development -- South Africa -- Sociological aspects Rural development projects -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1155 , http://hdl.handle.net/10962/d1011116
- Description: Many Information and Communication Technologies for Development (ICTD) projects are established with the overall aim of positively developing the communities they are implemented in. However, the solutions that are provided are often commonly developed without the needs of these communities being sufficiently investigated beforehand. As a result the ICTD strategy of the project ends up not well aligned with the aims and targets of the needs of the community. As a result of this, an appropriate programme theory for the project and relevant impact indicators fail to be adequately developed. Consequently, when an impact assessment is conducted it is often found that the intended effects are not directly linked to the needs of the community or what the community had hoped to gain from the ICTD initiative. The purpose of this research serves to develop a needs-ICTD strategy alignment foundation that supports the identification and formulation of impact assessment indicators. Through this research, a framework is developed to support the alignment of ICTD strategy, the development and the promotion of contextual needs of rural communities and other frequently marginalized areas. The Needs-ICTD strategy alignment framework is composed of eight main components that describe the process that can be used to align ICTD strategy with community needs. These components include: collaboration between the internal and external stakeholders, the development of the community, conducting baseline studies, the needs assessment, the ICTD strategy, linking of the needs-ICTD strategy, and lastly the identification of impact indicators. An interpretive research approach is used to explore and inform the framework through a multi-case study investigation of the Siyakhula Living Lab and two projects in the Systems Application Products (SAP) Living Lab. Two main case study questions drive the exploration of the framework, that being: 1) How are the needs of the community elicited and how is the ICTD strategy aligned to the needs of the community? 2) And, why were the selected approaches chosen for aligning the needs of the community and ICTD strategy? Data for this research was collected qualitatively through interviews, document analysis and participant observation. Key findings indicate that the involvement of internal (local) stakeholders in the development and alignment of ICTD strategy to the needs of the community is still lacking. As a consequence, many community members end up not fully understanding the project objectives and how these objectives aims are to be achieved. The research also finds that ‘solution specific’ projects also fail communities as they focus specifically on one target group and repeatedly fail to assist the community holistically in supporting their information and their community development needs.
- Full Text:
- Authors: Baduza, Gugulethu Qhawekazi
- Date: 2014
- Subjects: Siyakhula Living Lab SAP Research Needs assessment -- Information technology -- Social aspects -- South Africa -- Case studies Information technology -- South Africa -- Management -- Case studies Information technology -- Social aspects -- South Africa Rural development -- Economic aspects -- South Africa Rural development -- South Africa -- Sociological aspects Rural development projects -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1155 , http://hdl.handle.net/10962/d1011116
- Description: Many Information and Communication Technologies for Development (ICTD) projects are established with the overall aim of positively developing the communities they are implemented in. However, the solutions that are provided are often commonly developed without the needs of these communities being sufficiently investigated beforehand. As a result the ICTD strategy of the project ends up not well aligned with the aims and targets of the needs of the community. As a result of this, an appropriate programme theory for the project and relevant impact indicators fail to be adequately developed. Consequently, when an impact assessment is conducted it is often found that the intended effects are not directly linked to the needs of the community or what the community had hoped to gain from the ICTD initiative. The purpose of this research serves to develop a needs-ICTD strategy alignment foundation that supports the identification and formulation of impact assessment indicators. Through this research, a framework is developed to support the alignment of ICTD strategy, the development and the promotion of contextual needs of rural communities and other frequently marginalized areas. The Needs-ICTD strategy alignment framework is composed of eight main components that describe the process that can be used to align ICTD strategy with community needs. These components include: collaboration between the internal and external stakeholders, the development of the community, conducting baseline studies, the needs assessment, the ICTD strategy, linking of the needs-ICTD strategy, and lastly the identification of impact indicators. An interpretive research approach is used to explore and inform the framework through a multi-case study investigation of the Siyakhula Living Lab and two projects in the Systems Application Products (SAP) Living Lab. Two main case study questions drive the exploration of the framework, that being: 1) How are the needs of the community elicited and how is the ICTD strategy aligned to the needs of the community? 2) And, why were the selected approaches chosen for aligning the needs of the community and ICTD strategy? Data for this research was collected qualitatively through interviews, document analysis and participant observation. Key findings indicate that the involvement of internal (local) stakeholders in the development and alignment of ICTD strategy to the needs of the community is still lacking. As a consequence, many community members end up not fully understanding the project objectives and how these objectives aims are to be achieved. The research also finds that ‘solution specific’ projects also fail communities as they focus specifically on one target group and repeatedly fail to assist the community holistically in supporting their information and their community development needs.
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A new approach to obesity for health journalism: fit not fat
- Authors: Dugmore, Harry
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158620 , vital:40212 , https://hdl.handle.net/10520/EJC159484
- Description: Health journalism is a complicated beat. The science is easy to get wrong, and the tone and tenor of the reporting needs careful attention. Coverage of obesity is even more fraught. Early insights from an on-going research project by the Discovery Centre for Health Journalism suggests that not only is most journalism about obesity not helping - some reporting may inadvertently be making the situation worse. This needs to change. There is too much at stake for journalism about food, fat and fitness to be anything less than impactful and effective.
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- Authors: Dugmore, Harry
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158620 , vital:40212 , https://hdl.handle.net/10520/EJC159484
- Description: Health journalism is a complicated beat. The science is easy to get wrong, and the tone and tenor of the reporting needs careful attention. Coverage of obesity is even more fraught. Early insights from an on-going research project by the Discovery Centre for Health Journalism suggests that not only is most journalism about obesity not helping - some reporting may inadvertently be making the situation worse. This needs to change. There is too much at stake for journalism about food, fat and fitness to be anything less than impactful and effective.
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A new approach to representations of revolution
- Authors: Burke, Matthew Ainslie
- Date: 2014
- Subjects: Radicalism in literature , Radicalism in literature -- Moral and ethical aspects , Politics and literature -- Moral and ethical aspects , Revolutionary literature, English
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2310 , http://hdl.handle.net/10962/d1013068
- Description: This project asserts that revolution is characterised by the expression of unthinkable possibilities, and so addresses the paradox implicit in any attempt to "write revolution." That is, how does one represent revolution without reducing it to an ordered term of reference, and thereby subduing its radical character? Additionally, can transformative action be conceptualised as a creative project to which an ethical subject may, and in fact should, be drawn? To answer these questions, my investigation develops in three strands. I combine the radical theory of Alain Badiou with similar affirmations of revolutionary intervention from Slavoj Žižek and Paulo Freire, and so create an aesthetic that affirms revolutionaries as agents of supplementary creativity. My first purpose is thus to establish revolution as a productive enterprise that enables peace, rather than a destructive undertaking that introduces violence. This done, I apply the resultant conceptual tools to literary representations of radical transformation, and demonstrate that my aesthetic enables new readings of the literature of revolution to which it is applied. In the course of my analysis, I also evaluate the suitability of Badiou's ethic as a standpoint from which to engage with literature on revolution. Ultimately, then, the aesthetic I construct not only contests the notion that radical transformation is always destructive, but also renders one sensitive to revolutionary literature's excessive and supplementary dimensions.
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- Authors: Burke, Matthew Ainslie
- Date: 2014
- Subjects: Radicalism in literature , Radicalism in literature -- Moral and ethical aspects , Politics and literature -- Moral and ethical aspects , Revolutionary literature, English
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2310 , http://hdl.handle.net/10962/d1013068
- Description: This project asserts that revolution is characterised by the expression of unthinkable possibilities, and so addresses the paradox implicit in any attempt to "write revolution." That is, how does one represent revolution without reducing it to an ordered term of reference, and thereby subduing its radical character? Additionally, can transformative action be conceptualised as a creative project to which an ethical subject may, and in fact should, be drawn? To answer these questions, my investigation develops in three strands. I combine the radical theory of Alain Badiou with similar affirmations of revolutionary intervention from Slavoj Žižek and Paulo Freire, and so create an aesthetic that affirms revolutionaries as agents of supplementary creativity. My first purpose is thus to establish revolution as a productive enterprise that enables peace, rather than a destructive undertaking that introduces violence. This done, I apply the resultant conceptual tools to literary representations of radical transformation, and demonstrate that my aesthetic enables new readings of the literature of revolution to which it is applied. In the course of my analysis, I also evaluate the suitability of Badiou's ethic as a standpoint from which to engage with literature on revolution. Ultimately, then, the aesthetic I construct not only contests the notion that radical transformation is always destructive, but also renders one sensitive to revolutionary literature's excessive and supplementary dimensions.
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A Note on the (Continued) Ability of the Yield Curve to Forecast Economic Downturns in South Africa
- Authors: Botha, Ferdi , Keeton, Gavin
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/395994 , vital:69142 , xlink:href="https://doi.org/10.1111/saje.12053"
- Description: In 2002-2003, the South African yield spread falsely signalled a downswing that never materialised. This paper provides two reasons for this false signal. First, while the Reserve Bank never actually officially declared the start of a downswing, by alternative measures a downswing did actually occur. It is this severe weakness in economic activity at that time that the yield curve pointed to. Second, short-term interest rates in 2003 were higher than they should have been because of a mistake made in measuring consumer price inflation. Because South Africa had recently introduced an inflation-targeting regime, policy interest rates were, as a result of this error, kept too high for too long. This policy mistake was rectified as soon as the error in the Consumer Price Index was discovered. Thus, the yield curve in 2003 pointed to the reality that short-term interest rates were too high and risked pushing the economy into full blown recession. This is demonstrated by the fact that it was a fall in long bond interest rates that caused the yield spread to turn negative, indicating expectations that short-term interest rates would need to be cut – as indeed they were.
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- Authors: Botha, Ferdi , Keeton, Gavin
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/395994 , vital:69142 , xlink:href="https://doi.org/10.1111/saje.12053"
- Description: In 2002-2003, the South African yield spread falsely signalled a downswing that never materialised. This paper provides two reasons for this false signal. First, while the Reserve Bank never actually officially declared the start of a downswing, by alternative measures a downswing did actually occur. It is this severe weakness in economic activity at that time that the yield curve pointed to. Second, short-term interest rates in 2003 were higher than they should have been because of a mistake made in measuring consumer price inflation. Because South Africa had recently introduced an inflation-targeting regime, policy interest rates were, as a result of this error, kept too high for too long. This policy mistake was rectified as soon as the error in the Consumer Price Index was discovered. Thus, the yield curve in 2003 pointed to the reality that short-term interest rates were too high and risked pushing the economy into full blown recession. This is demonstrated by the fact that it was a fall in long bond interest rates that caused the yield spread to turn negative, indicating expectations that short-term interest rates would need to be cut – as indeed they were.
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A phenomenological study of the experiences of adolescents following maternal HIV-disclosure
- Sibanyoni, Sibongile Success
- Authors: Sibanyoni, Sibongile Success
- Date: 2014
- Subjects: HIV infections -- Transmission -- South Africa -- Grahamstown , HIV-positive youth -- South Africa -- Grahamstown , Teenagers -- Diseases -- South Africa -- Grahamstown , HIV infections -- Social aspects -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3231 , http://hdl.handle.net/10962/d1013125
- Description: Maternal HIV-disclosure to an adolescent is a controversial issue especially when considering the suitable time and context in which disclosure should take place. Furthermore there have been other considerations such as the adolescent’s emotional maturity as well as gender issues which have played a role in regards to determining whether the adolescent would be able to understand and cope effectively post-disclosure. These considerations formed the basis of this study’s aim and objectives which primarily focused on taking into account the developmental aspects apparent in the adolescent phase. These include adolescent’s relations with their mother, their peers and the meaning attached to having an education and career in their lives. For purposes of this study it was deemed important to actually explore with the adolescent’s the meaning they uphold pertaining to maternal HIVdisclosure. This differs from previous research which has focused predominantly on accessing adolescent’s experiences via their parents and in particular, their mothers. Data of only three participants was included following in-depth interviews being conducted. Data was analysed via Interpretive Phenomenological Analysis (IPA) which enabled an enhanced understanding and meaningful interpretation of the adolescent’s experiences following maternal HIV-disclosure. From the findings it became apparent that most concerns had already been addressed and were similar when compared to previous research that had been conducted. However one notable different finding was that instead of adolescent’s acting in ways that would lead to them self-sabotaging their lives they instead portrayed themselves to be living in a responsible manner. It became apparent rather that it was the adolescent’s mother rather that became more inclined to engage in self-sabotaging behaviours.
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- Authors: Sibanyoni, Sibongile Success
- Date: 2014
- Subjects: HIV infections -- Transmission -- South Africa -- Grahamstown , HIV-positive youth -- South Africa -- Grahamstown , Teenagers -- Diseases -- South Africa -- Grahamstown , HIV infections -- Social aspects -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3231 , http://hdl.handle.net/10962/d1013125
- Description: Maternal HIV-disclosure to an adolescent is a controversial issue especially when considering the suitable time and context in which disclosure should take place. Furthermore there have been other considerations such as the adolescent’s emotional maturity as well as gender issues which have played a role in regards to determining whether the adolescent would be able to understand and cope effectively post-disclosure. These considerations formed the basis of this study’s aim and objectives which primarily focused on taking into account the developmental aspects apparent in the adolescent phase. These include adolescent’s relations with their mother, their peers and the meaning attached to having an education and career in their lives. For purposes of this study it was deemed important to actually explore with the adolescent’s the meaning they uphold pertaining to maternal HIVdisclosure. This differs from previous research which has focused predominantly on accessing adolescent’s experiences via their parents and in particular, their mothers. Data of only three participants was included following in-depth interviews being conducted. Data was analysed via Interpretive Phenomenological Analysis (IPA) which enabled an enhanced understanding and meaningful interpretation of the adolescent’s experiences following maternal HIV-disclosure. From the findings it became apparent that most concerns had already been addressed and were similar when compared to previous research that had been conducted. However one notable different finding was that instead of adolescent’s acting in ways that would lead to them self-sabotaging their lives they instead portrayed themselves to be living in a responsible manner. It became apparent rather that it was the adolescent’s mother rather that became more inclined to engage in self-sabotaging behaviours.
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A preliminary assessment linking altered catchment land-cover to the health of four temporarily open/closed South African estuaries
- Authors: Masefield, Vincent Antony
- Date: 2014
- Subjects: Estuarine ecology -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4877 , http://hdl.handle.net/10962/d1013096
- Description: Estuaries worldwide are being subjected to various degrees of catchment degradation, which is having severe consequences on the integrity of these aquatic ecosystems and their ability to function properly. This thesis investigated the relationship between catchment land-cover and estuarine health in four temporarily open/closed estuarine systems (TOCEs) in South Africa, namely the Groot Brak, East Kleinemonde, Mdloti and Tongati. GIS techniques were employed to delineate catchments, lower sections of catchments, 1 km and 100 m buffer zones, and to quantify the extent of land-cover classes present within these delineations. Anthropogenic activities outlined by the Department of Water Affairs and Forestry (DWAF) Resource Directed Measures (RDM) studies and their associated land-cover classes were described. The possible links between catchment and buffer zone land-cover class composition and health of the estuaries were explored. Results indicated that there was a relationship between catchment and estuarine health within the Coastal Protection Zone (CPZ) (1 km and 100 m) buffers, but not at a broader catchment level. Out of natural, urban built-up and cultivation land-cover classes, natural land was determined to be the best predictor of estuarine health within the CPZs. A method of rapidly assessing South African TOCE condition was applied and could be used to prioritise these estuaries for rehabilitation and/or conservation.
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- Authors: Masefield, Vincent Antony
- Date: 2014
- Subjects: Estuarine ecology -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4877 , http://hdl.handle.net/10962/d1013096
- Description: Estuaries worldwide are being subjected to various degrees of catchment degradation, which is having severe consequences on the integrity of these aquatic ecosystems and their ability to function properly. This thesis investigated the relationship between catchment land-cover and estuarine health in four temporarily open/closed estuarine systems (TOCEs) in South Africa, namely the Groot Brak, East Kleinemonde, Mdloti and Tongati. GIS techniques were employed to delineate catchments, lower sections of catchments, 1 km and 100 m buffer zones, and to quantify the extent of land-cover classes present within these delineations. Anthropogenic activities outlined by the Department of Water Affairs and Forestry (DWAF) Resource Directed Measures (RDM) studies and their associated land-cover classes were described. The possible links between catchment and buffer zone land-cover class composition and health of the estuaries were explored. Results indicated that there was a relationship between catchment and estuarine health within the Coastal Protection Zone (CPZ) (1 km and 100 m) buffers, but not at a broader catchment level. Out of natural, urban built-up and cultivation land-cover classes, natural land was determined to be the best predictor of estuarine health within the CPZs. A method of rapidly assessing South African TOCE condition was applied and could be used to prioritise these estuaries for rehabilitation and/or conservation.
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A promising biological control agent for the invasive alien plant, Pereskia aculeata Miller (Cactaceae), in South Africa
- Paterson, Iain D, Mdodana, Lumka A, Mpekula, Ongezwa, Mabunda, Bheki D, Hill, Martin P
- Authors: Paterson, Iain D , Mdodana, Lumka A , Mpekula, Ongezwa , Mabunda, Bheki D , Hill, Martin P
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/416806 , vital:71387 , xlink:href="https://doi.org/10.1080/09583157.2014.919439"
- Description: Pereskia aculeata Miller (Cactaceae) is an invasive alien plant from Central and South America that has become a problematic environmental weed in South Africa. A potential biological control agent, the stem-wilter, Catorhintha schaffneri Brailovsky and Garcia (Coreidae), was collected in southern Brazil and imported into quarantine in South Africa. Field host range data suggested that C. schaffneri has a host range restricted to P. aculeata. No-choice nymph survival tests were then conducted on 27 test plant species in 9 families. Survival to the adult stage was only recorded on P. aculeata and the closely related Pereskia grandifolia Haw. (Cactaceae). Mortality was significantly higher on P. grandifolia with only 3% of the nymphs reaching the adult stage compared with 74% on P. aculeata indicating that P. aculeata is the primary host plant. P. grandifolia is native in South America and is of no agricultural importance in South Africa so any feeding on P. grandifolia in South Africa would have no negative environmental or economic consequences. In other tests, adult survival on P. aculeata [25.8 days (SE ± 3.74)] was significantly longer than on other test plant species [4.3 days (SE ± 0.36)] further confirming the host specificity of the species. Impact studies conducted in quarantine indicated that C. schaffneri is damaging to P. aculeata, significantly reducing the number of leaves and the shoot lengths of plants, even at relatively low insect densities. C. schaffneri is safe for release in South Africa and is likely to be a damaging and effective agent.
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- Authors: Paterson, Iain D , Mdodana, Lumka A , Mpekula, Ongezwa , Mabunda, Bheki D , Hill, Martin P
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/416806 , vital:71387 , xlink:href="https://doi.org/10.1080/09583157.2014.919439"
- Description: Pereskia aculeata Miller (Cactaceae) is an invasive alien plant from Central and South America that has become a problematic environmental weed in South Africa. A potential biological control agent, the stem-wilter, Catorhintha schaffneri Brailovsky and Garcia (Coreidae), was collected in southern Brazil and imported into quarantine in South Africa. Field host range data suggested that C. schaffneri has a host range restricted to P. aculeata. No-choice nymph survival tests were then conducted on 27 test plant species in 9 families. Survival to the adult stage was only recorded on P. aculeata and the closely related Pereskia grandifolia Haw. (Cactaceae). Mortality was significantly higher on P. grandifolia with only 3% of the nymphs reaching the adult stage compared with 74% on P. aculeata indicating that P. aculeata is the primary host plant. P. grandifolia is native in South America and is of no agricultural importance in South Africa so any feeding on P. grandifolia in South Africa would have no negative environmental or economic consequences. In other tests, adult survival on P. aculeata [25.8 days (SE ± 3.74)] was significantly longer than on other test plant species [4.3 days (SE ± 0.36)] further confirming the host specificity of the species. Impact studies conducted in quarantine indicated that C. schaffneri is damaging to P. aculeata, significantly reducing the number of leaves and the shoot lengths of plants, even at relatively low insect densities. C. schaffneri is safe for release in South Africa and is likely to be a damaging and effective agent.
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