Comparison of plant diversity in protected and communal lands in the Bushbuckridge lowveld savanna, South Africa
- Authors: Shackleton, Charlie M
- Date: 2000
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181885 , vital:43777 , xlink:href="https://doi.org/10.1016/S0006-3207(00)00001-X"
- Description: Patterns of higher plant species richness and beta diversity were assessed using standard Modified-Whittaker plots in relation to land use, slope position and mean annual rainfall across a rainfall gradient in the savanna areas of the Bushbuckridge lowveld, South Africa. In particular, comparison of communal areas with adjacent protected areas was important in showing the impacts of potential changes in land use within an overarching catchment management plan. Although most of the protected areas considered preservation of biodiversity as their primary goal, they were characterised by significantly fewer plant species than the adjacent, highly utilised, communal lands, at both the plot and point scale. Slope position also had a significant effect on plant species richness, with eutrophic bottomlands having c. 30% more species than the dystrophic toplands. This adds weight to the need for greater public awareness for the judicious use and management of the sensitive bottomlands, which fringe the primary drainage lines that are vital for sustained supplies of good quality surface water in this semi-arid environment. The total number of species increased with increasing mean annual rainfall across the rainfall gradient. This suggests that, if the catchment management plan aims to identify additional areas for conservation, the higher rainfall areas should be the first to be assessed. Species turnover was greater along the rainfall gradient than the catenal gradient between toplands and bottomlands.
- Full Text:
- Authors: Shackleton, Charlie M
- Date: 2000
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181885 , vital:43777 , xlink:href="https://doi.org/10.1016/S0006-3207(00)00001-X"
- Description: Patterns of higher plant species richness and beta diversity were assessed using standard Modified-Whittaker plots in relation to land use, slope position and mean annual rainfall across a rainfall gradient in the savanna areas of the Bushbuckridge lowveld, South Africa. In particular, comparison of communal areas with adjacent protected areas was important in showing the impacts of potential changes in land use within an overarching catchment management plan. Although most of the protected areas considered preservation of biodiversity as their primary goal, they were characterised by significantly fewer plant species than the adjacent, highly utilised, communal lands, at both the plot and point scale. Slope position also had a significant effect on plant species richness, with eutrophic bottomlands having c. 30% more species than the dystrophic toplands. This adds weight to the need for greater public awareness for the judicious use and management of the sensitive bottomlands, which fringe the primary drainage lines that are vital for sustained supplies of good quality surface water in this semi-arid environment. The total number of species increased with increasing mean annual rainfall across the rainfall gradient. This suggests that, if the catchment management plan aims to identify additional areas for conservation, the higher rainfall areas should be the first to be assessed. Species turnover was greater along the rainfall gradient than the catenal gradient between toplands and bottomlands.
- Full Text:
Computers in science teaching: a reality or dream; The role of computers in effective science education: a case of using a computer to teach colour mixing; Career oriented science education for the next millennium
- Authors: Nadarajah, Kumaravel
- Date: 2000
- Subjects: Science -- Study and teaching Computer-assisted instruction Education -- Data processing
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1460 , http://hdl.handle.net/10962/d1003341
- Description: Science education in South Africa is not improving much. Many science educators do not have appropriate science qualifications. Majority of the learners have limited facilities to learn science. In this dilemma the move to OBE may result in further substantial deterioration of science education. A possible way out is to use computers in science education to facilitate the learning process. This study was designed to investigate how computers contribute to learners’ skills development in a physics course. A series of interactive computer simulations of colour mixing and a number of closely related traditional practical activities are aimed to promote learners’ understanding of colour. It was concluded that while computer environments have greater potentialas learning tools, they also limit interactions in significant ways.
- Full Text:
- Authors: Nadarajah, Kumaravel
- Date: 2000
- Subjects: Science -- Study and teaching Computer-assisted instruction Education -- Data processing
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1460 , http://hdl.handle.net/10962/d1003341
- Description: Science education in South Africa is not improving much. Many science educators do not have appropriate science qualifications. Majority of the learners have limited facilities to learn science. In this dilemma the move to OBE may result in further substantial deterioration of science education. A possible way out is to use computers in science education to facilitate the learning process. This study was designed to investigate how computers contribute to learners’ skills development in a physics course. A series of interactive computer simulations of colour mixing and a number of closely related traditional practical activities are aimed to promote learners’ understanding of colour. It was concluded that while computer environments have greater potentialas learning tools, they also limit interactions in significant ways.
- Full Text:
Constitutional frameworks and democratization in Africa since independence
- Authors: Neirynck, Karim
- Date: 2000
- Subjects: Democracy -- Africa , Constitutions -- Africa , Africa -- Politics and government -- 1960-
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2816 , http://hdl.handle.net/10962/d1003026 , Democracy -- Africa , Constitutions -- Africa , Africa -- Politics and government -- 1960-
- Description: The subject of this thesis is international studies, specifically a study of constitutional frameworks in Africa in the second half of the 20th century, focussing on a statistical correlation between constitutional frameworks, party systems, electoral systems and the Index of Democracy. The struggle to consolidate new democracies - especially those in Eastern Europe, Latin America and Asia - has given rise to a wide-ranging debate about the hard choices concerning democratic political institutions and political markets. According to Stepan and Skach " this literature has produced provocative hypotheses about the effects of institutions on democracy" (Stepan and Skach, 1993 : 1). It forms part of the' new institutionalism I literature in comparative politics that'holds as a premise that political democracy depends not only on economic and social conditions but also on the design of political institutions (Koelble, 1995 : 231-243). " One fundamental political-institutional question that has only received serious scholarly attention concerns the impact of different constitutional frameworks on democratic consolidation. Although the topic has been increasingly debated and discussed, little systematic cross-regional evidence [especially for our field of research: Africa] has been brought to bear on it " (Stepan and Skach, 1993 : 1-2). So far, only the book"on regime transitions in Africa written by Bratton and Van De Walle seeks to fill this empirical gap (Bratton and Van De Walle, 1997, preface xiii). In this thesis, we paid particular attention to the dichotomy between (pure) parliamentarism and (pure) presidentialism. Each type has fundamental characteristics, and for the purposes of classification these characteristics are necessary and sufficient. It was not our purpose to weigh the benefits and drawbacks of parliamentarism and presidentialism. Our intention was to report and analyse different sources of data, and we based our case exclusively on statistic correlatiohs between regime type and the record of democratic success and failure. We collected a data set about constitutional frameworks (matrix1), democracy indices (matrix2), party systems (matrix3) and election systems (matrix4). The basis for matrix 1 was the constitutions of the African countries (over time) and relevant literature. The basis for matrix 2 was the annual Freedom House ratings made by Raymond D. Gastil and others. The basis for matrix 3 and 4 was relevant literature. Once these matrices had been composed, we compared them and calculated statistic correlations. This long-dyration model allowed us to estimate whether African constitutional frameworks, party systems and electoral systems exhibit positive or negative correlation with the index of democracy.
- Full Text:
- Authors: Neirynck, Karim
- Date: 2000
- Subjects: Democracy -- Africa , Constitutions -- Africa , Africa -- Politics and government -- 1960-
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2816 , http://hdl.handle.net/10962/d1003026 , Democracy -- Africa , Constitutions -- Africa , Africa -- Politics and government -- 1960-
- Description: The subject of this thesis is international studies, specifically a study of constitutional frameworks in Africa in the second half of the 20th century, focussing on a statistical correlation between constitutional frameworks, party systems, electoral systems and the Index of Democracy. The struggle to consolidate new democracies - especially those in Eastern Europe, Latin America and Asia - has given rise to a wide-ranging debate about the hard choices concerning democratic political institutions and political markets. According to Stepan and Skach " this literature has produced provocative hypotheses about the effects of institutions on democracy" (Stepan and Skach, 1993 : 1). It forms part of the' new institutionalism I literature in comparative politics that'holds as a premise that political democracy depends not only on economic and social conditions but also on the design of political institutions (Koelble, 1995 : 231-243). " One fundamental political-institutional question that has only received serious scholarly attention concerns the impact of different constitutional frameworks on democratic consolidation. Although the topic has been increasingly debated and discussed, little systematic cross-regional evidence [especially for our field of research: Africa] has been brought to bear on it " (Stepan and Skach, 1993 : 1-2). So far, only the book"on regime transitions in Africa written by Bratton and Van De Walle seeks to fill this empirical gap (Bratton and Van De Walle, 1997, preface xiii). In this thesis, we paid particular attention to the dichotomy between (pure) parliamentarism and (pure) presidentialism. Each type has fundamental characteristics, and for the purposes of classification these characteristics are necessary and sufficient. It was not our purpose to weigh the benefits and drawbacks of parliamentarism and presidentialism. Our intention was to report and analyse different sources of data, and we based our case exclusively on statistic correlatiohs between regime type and the record of democratic success and failure. We collected a data set about constitutional frameworks (matrix1), democracy indices (matrix2), party systems (matrix3) and election systems (matrix4). The basis for matrix 1 was the constitutions of the African countries (over time) and relevant literature. The basis for matrix 2 was the annual Freedom House ratings made by Raymond D. Gastil and others. The basis for matrix 3 and 4 was relevant literature. Once these matrices had been composed, we compared them and calculated statistic correlations. This long-dyration model allowed us to estimate whether African constitutional frameworks, party systems and electoral systems exhibit positive or negative correlation with the index of democracy.
- Full Text:
Criteria social workers employ in making child custody recommendations
- Authors: Froneman, Anna Petronella
- Date: 2000
- Subjects: Custody of children -- South Africa Social work with children -- South Africa
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:696 , http://hdl.handle.net/10962/d1006414
- Description: During this study, an attempt was made to investigate the process employed by social workers in conducting child custody evaluations and making decisions related to the process, as well as to provide insight into which criteria are currently being used. The goal was to explore the perceived usefulness of these criteria from the perspective of social work, and to assess the adequacy of the requirements of the custody report in reflecting the above process and decision-making. In order to meet this goal, literature and empirical studies were conducted. The literature study focuses on the history of child custody matters, custody decision-making and legislation, types of custody arrangements, criteria social workers employ in making child custody recommendations, evaluator bias and custody evaluation reports. During the empirical research phase, a non-probability purposive sampling procedure was adopted. Five family counsellors from the office of the family advocate serving the Eastern Cape were selected. After an interview schedule was compiled to cover certain topics and their sequence, semi-structured interviews were conducted with the family counsellors. In order to compare the criteria stated in the interviews with the criteria applied in the custody reports, three cases from each family counsellor were selected and the final custody report and recommendation were studied. This study has revealed the following: some of the family counsellors experience proqlems with the process of custody evaluations; certain aspects regarding the process are not in line with some ofthe literature; some of the criteria used by the family counsellors are not evident in the custody reports and are not discussed in detail; a lack of training exists for the family counsellors; and the family counsellors experience some form of bias. Finally, based on the research findings, recommendations were made regarding the process of custody evaluation, the criteria social workers employ when conducting child custody evaluations, training and bias of family counsellors, the role of the family advocate and possible future research.
- Full Text:
- Authors: Froneman, Anna Petronella
- Date: 2000
- Subjects: Custody of children -- South Africa Social work with children -- South Africa
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:696 , http://hdl.handle.net/10962/d1006414
- Description: During this study, an attempt was made to investigate the process employed by social workers in conducting child custody evaluations and making decisions related to the process, as well as to provide insight into which criteria are currently being used. The goal was to explore the perceived usefulness of these criteria from the perspective of social work, and to assess the adequacy of the requirements of the custody report in reflecting the above process and decision-making. In order to meet this goal, literature and empirical studies were conducted. The literature study focuses on the history of child custody matters, custody decision-making and legislation, types of custody arrangements, criteria social workers employ in making child custody recommendations, evaluator bias and custody evaluation reports. During the empirical research phase, a non-probability purposive sampling procedure was adopted. Five family counsellors from the office of the family advocate serving the Eastern Cape were selected. After an interview schedule was compiled to cover certain topics and their sequence, semi-structured interviews were conducted with the family counsellors. In order to compare the criteria stated in the interviews with the criteria applied in the custody reports, three cases from each family counsellor were selected and the final custody report and recommendation were studied. This study has revealed the following: some of the family counsellors experience proqlems with the process of custody evaluations; certain aspects regarding the process are not in line with some ofthe literature; some of the criteria used by the family counsellors are not evident in the custody reports and are not discussed in detail; a lack of training exists for the family counsellors; and the family counsellors experience some form of bias. Finally, based on the research findings, recommendations were made regarding the process of custody evaluation, the criteria social workers employ when conducting child custody evaluations, training and bias of family counsellors, the role of the family advocate and possible future research.
- Full Text:
Cuba's revolutionist and anti-imperialist foreign policy in Southern Africa: the case of Angola and Namibia
- Authors: Othieno, Timothy
- Date: 2000
- Subjects: Cuba -- Foreign Relations -- Africa, Southern , Cuba -- Dependency on foreign countries -- History , Cuba -- Foreign relations -- Angola , Cuba -- Foreign relations -- Namibia , Cuba -- Politics and government
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2819 , http://hdl.handle.net/10962/d1003029 , Cuba -- Foreign Relations -- Africa, Southern , Cuba -- Dependency on foreign countries -- History , Cuba -- Foreign relations -- Angola , Cuba -- Foreign relations -- Namibia , Cuba -- Politics and government
- Description: This study examines Cuba’s role in the two southern African countries of Angola and Namibia during the Cold War period. It argues that Cuba’s ideological motivations have been embodied in the mutually reinforcing concepts of proletarian internationalism and anti-imperialism. These conceptual perspectives constitute some of the central variables that influence Cuba’s foreign policy behaviour in international relations. It is within this context that one can understand Cuba’s involvement in Southern Africa. This study also attempts to explain that Cuban foreign policy towards Africa was based on two complementary and contextual objectives namely, promoting nationalism at home and nurturing revolutionary Marxist-Leninist governments, as well as supporting anti-colonial and anti-imperialist movements abroad. For the purpose of achieving these foreign policy objectives, Cuba not only engaged in state-to-state relations with Angola and Namibia; but had cordial relations with the rest of the continent and in particular Southern Africa, which also became a direct military testing ground for Cuba’s commitment to an anti-colonial and anti-imperialist revolutionary stance. Furthermore, the thesis shows that Cuba’s relentless hatred of imperialism is rooted in its historical relationship with the United States because from the turn of the century till 1958, the Americans interfered in Cuba’s internal affairs by supporting corrupt administrations and exploited the country. These practices by the United States laid the foundation for Cuba’s anti-colonialism and antiimperialism abroad. Ultimately, this thesis shows that Cuban involvement in Angola and Namibia can be conceptualised within these contexts (anti-imperialism, anti-colonialism, proletarian internationalism and revolutionary Marxism-Leninism). The role of Cuban nationalism in the realisation of these objectives and ideals, as well as its role in perpetuating and consolidating her foreign policy is assessed in this study. This nationalism and ideals of internationalism constitutes the central idea in the Cuban revolution. Finally, this thesis asserts that Cuban motives for getting involved in the politics of Southern Africa were not motivated by economic or imperialistic reasons. Rather, the historical similarity and colonial experiences between Africa and Cuba were some of the central causal factors.
- Full Text:
- Authors: Othieno, Timothy
- Date: 2000
- Subjects: Cuba -- Foreign Relations -- Africa, Southern , Cuba -- Dependency on foreign countries -- History , Cuba -- Foreign relations -- Angola , Cuba -- Foreign relations -- Namibia , Cuba -- Politics and government
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2819 , http://hdl.handle.net/10962/d1003029 , Cuba -- Foreign Relations -- Africa, Southern , Cuba -- Dependency on foreign countries -- History , Cuba -- Foreign relations -- Angola , Cuba -- Foreign relations -- Namibia , Cuba -- Politics and government
- Description: This study examines Cuba’s role in the two southern African countries of Angola and Namibia during the Cold War period. It argues that Cuba’s ideological motivations have been embodied in the mutually reinforcing concepts of proletarian internationalism and anti-imperialism. These conceptual perspectives constitute some of the central variables that influence Cuba’s foreign policy behaviour in international relations. It is within this context that one can understand Cuba’s involvement in Southern Africa. This study also attempts to explain that Cuban foreign policy towards Africa was based on two complementary and contextual objectives namely, promoting nationalism at home and nurturing revolutionary Marxist-Leninist governments, as well as supporting anti-colonial and anti-imperialist movements abroad. For the purpose of achieving these foreign policy objectives, Cuba not only engaged in state-to-state relations with Angola and Namibia; but had cordial relations with the rest of the continent and in particular Southern Africa, which also became a direct military testing ground for Cuba’s commitment to an anti-colonial and anti-imperialist revolutionary stance. Furthermore, the thesis shows that Cuba’s relentless hatred of imperialism is rooted in its historical relationship with the United States because from the turn of the century till 1958, the Americans interfered in Cuba’s internal affairs by supporting corrupt administrations and exploited the country. These practices by the United States laid the foundation for Cuba’s anti-colonialism and antiimperialism abroad. Ultimately, this thesis shows that Cuban involvement in Angola and Namibia can be conceptualised within these contexts (anti-imperialism, anti-colonialism, proletarian internationalism and revolutionary Marxism-Leninism). The role of Cuban nationalism in the realisation of these objectives and ideals, as well as its role in perpetuating and consolidating her foreign policy is assessed in this study. This nationalism and ideals of internationalism constitutes the central idea in the Cuban revolution. Finally, this thesis asserts that Cuban motives for getting involved in the politics of Southern Africa were not motivated by economic or imperialistic reasons. Rather, the historical similarity and colonial experiences between Africa and Cuba were some of the central causal factors.
- Full Text:
Cumulative mild head injury in contact sport: a comparison of the cognitive profiles of rugby players and non-contact sport controls with normative data
- Authors: Bold, Lisa Clare
- Date: 2000
- Subjects: Head -- Wounds and injuries -- Psychology , Neuropsychological tests , Head -- Wounds and injuries , Sports injuries -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2935 , http://hdl.handle.net/10962/d1002444 , Head -- Wounds and injuries -- Psychology , Neuropsychological tests , Head -- Wounds and injuries , Sports injuries -- Psychological aspects
- Description: This study investigates the effects of cumulative mild head injury on the cognitive functioning of elite rugby players. A comprehensive battery of neuropsychological tests was administered to top national (Springbok) rugby players (n=26), national Under 21 rugby players (n= 19), and a non-contact sport control group of national hockey players (n=21). The test results of the Total Rugby group (Springbok Rugby and Under 21 Rugby players), the Under 21 Rugby group, the hockey controls, and the Total Rugby and Under 21 Rugby forward and backline players respectively, were each compared with established normative data. Results showed significant differences in the direction of a poorer performance relative to the norms for the Total Rugby and Under 21 Rugby groups, and for the Total Rugby Forwards and Under 21 Rugby Forwards, on tests sensitive to the effects of diffuse brain damage. On the other hand, the Hockey Control group and the Total Rugby Backs and Under 21 Rugby Backs tended to perform within the normal range or better than the norm on some tests. These results confirm the hypothesis that rugby players, and the forward players in particular, are at risk of adverse cognitive effects consequent on cumulative mild head injury. The theoretical implications are that the aggregate effects of multiple exposures to mild head injuries in the rugby players served to reduce their brain reserve capacities and acted as a threshold-lowering influence associated with symptom onset.
- Full Text:
- Authors: Bold, Lisa Clare
- Date: 2000
- Subjects: Head -- Wounds and injuries -- Psychology , Neuropsychological tests , Head -- Wounds and injuries , Sports injuries -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2935 , http://hdl.handle.net/10962/d1002444 , Head -- Wounds and injuries -- Psychology , Neuropsychological tests , Head -- Wounds and injuries , Sports injuries -- Psychological aspects
- Description: This study investigates the effects of cumulative mild head injury on the cognitive functioning of elite rugby players. A comprehensive battery of neuropsychological tests was administered to top national (Springbok) rugby players (n=26), national Under 21 rugby players (n= 19), and a non-contact sport control group of national hockey players (n=21). The test results of the Total Rugby group (Springbok Rugby and Under 21 Rugby players), the Under 21 Rugby group, the hockey controls, and the Total Rugby and Under 21 Rugby forward and backline players respectively, were each compared with established normative data. Results showed significant differences in the direction of a poorer performance relative to the norms for the Total Rugby and Under 21 Rugby groups, and for the Total Rugby Forwards and Under 21 Rugby Forwards, on tests sensitive to the effects of diffuse brain damage. On the other hand, the Hockey Control group and the Total Rugby Backs and Under 21 Rugby Backs tended to perform within the normal range or better than the norm on some tests. These results confirm the hypothesis that rugby players, and the forward players in particular, are at risk of adverse cognitive effects consequent on cumulative mild head injury. The theoretical implications are that the aggregate effects of multiple exposures to mild head injuries in the rugby players served to reduce their brain reserve capacities and acted as a threshold-lowering influence associated with symptom onset.
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Cyanide-induced free radical production and lipid peroxidation in rat brain homogenate is reduced by aspirin
- Daya, Santylal, Walker, Roderick B, Anoopkumar-Dukie, Shailendra
- Authors: Daya, Santylal , Walker, Roderick B , Anoopkumar-Dukie, Shailendra
- Date: 2000
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184346 , vital:44210 , xlink:href="https://doi.org/10.1007/BF02674529"
- Description: The neuroprotective properties of aspirin were investigated using cyanide-induced neurotoxicity as model. Cyanide, a known neurotoxic agent significantly increased lipid peroxidation and superoxide anion levels in rat brain homogenate in a concentration-dependent manner (0.25–1.0 mM). When homogenate, containing 1.0 mM KCN was cotreated with aspirin (1.0 mM) there was a significant decrease in lipid peroxidation. Aspirin (0.5 mM and 1.0 mM) also significantly reduced KCN-induced superoxide anion generation. The results of the present report therefore indicate a neuroprotective role for aspirin.
- Full Text:
- Authors: Daya, Santylal , Walker, Roderick B , Anoopkumar-Dukie, Shailendra
- Date: 2000
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184346 , vital:44210 , xlink:href="https://doi.org/10.1007/BF02674529"
- Description: The neuroprotective properties of aspirin were investigated using cyanide-induced neurotoxicity as model. Cyanide, a known neurotoxic agent significantly increased lipid peroxidation and superoxide anion levels in rat brain homogenate in a concentration-dependent manner (0.25–1.0 mM). When homogenate, containing 1.0 mM KCN was cotreated with aspirin (1.0 mM) there was a significant decrease in lipid peroxidation. Aspirin (0.5 mM and 1.0 mM) also significantly reduced KCN-induced superoxide anion generation. The results of the present report therefore indicate a neuroprotective role for aspirin.
- Full Text:
Desert
- Authors: Harper, Sean Julian
- Date: 2000
- Subjects: Rawls, John, 1921-2002 , Rawls, John, 1921-2002 Theory of justice , Ethics
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2710 , http://hdl.handle.net/10962/d1002840 , Rawls, John, 1921-2002 , Rawls, John, 1921-2002 Theory of justice , Ethics
- Description: This thesis examines the idea of desert as expounded in the work of John Rawls, and some of the implications of this conception of desert for moral and political philosophy. In this work, I analyse a series of arguments against retaining this particular conception of desert.I argue that none of these arguments sufficiently diminishes the force of Rawls’ argument for desert, while many of them do state, and I argue that they are correct in doing so, that this conception of desert is dangerous for political or moral philosophy to maintain. I argue that the moral, political and legal implications of accepting this account of desert severely undermine various institutions of differential treatment, and indeed, moral assessment. I regard it as obvious that societies must, on occasion, treat members of those societies differently, for moral, as well as practical reasons. The Rawlsian account of desert, and the account of responsibility on which it rests, however, will endanger the legitimacy of such procedures. I argue further that the Rawlsian account of desert requires that differences in wealth, and inheritance of wealth, influence and privilege be diminished, if not abolished, if we are to talk of any form of desert meaningfully. I argue that this is a strength of Rawls’ account, and further that any account of desert that is true to the philosophical tradition of the concept will require similar steps to be taken. The primary aim of this thesis is to show that Rawls’ arguments against desert are serious ones, both in terms of strength and scope, and that they must be addressed. I intend to show that these arguments are founded on strong moral intuitions, and that it is plausible that these intuitions may need revision. Finally,I intend to show that desert is an important moral and political concept, and that the disciplines of moral and political philosophy will be impoverished by the absence this concept. This absence, I will argue, is a natural consequence of the acceptance of the Rawlsian arguments.
- Full Text:
- Authors: Harper, Sean Julian
- Date: 2000
- Subjects: Rawls, John, 1921-2002 , Rawls, John, 1921-2002 Theory of justice , Ethics
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2710 , http://hdl.handle.net/10962/d1002840 , Rawls, John, 1921-2002 , Rawls, John, 1921-2002 Theory of justice , Ethics
- Description: This thesis examines the idea of desert as expounded in the work of John Rawls, and some of the implications of this conception of desert for moral and political philosophy. In this work, I analyse a series of arguments against retaining this particular conception of desert.I argue that none of these arguments sufficiently diminishes the force of Rawls’ argument for desert, while many of them do state, and I argue that they are correct in doing so, that this conception of desert is dangerous for political or moral philosophy to maintain. I argue that the moral, political and legal implications of accepting this account of desert severely undermine various institutions of differential treatment, and indeed, moral assessment. I regard it as obvious that societies must, on occasion, treat members of those societies differently, for moral, as well as practical reasons. The Rawlsian account of desert, and the account of responsibility on which it rests, however, will endanger the legitimacy of such procedures. I argue further that the Rawlsian account of desert requires that differences in wealth, and inheritance of wealth, influence and privilege be diminished, if not abolished, if we are to talk of any form of desert meaningfully. I argue that this is a strength of Rawls’ account, and further that any account of desert that is true to the philosophical tradition of the concept will require similar steps to be taken. The primary aim of this thesis is to show that Rawls’ arguments against desert are serious ones, both in terms of strength and scope, and that they must be addressed. I intend to show that these arguments are founded on strong moral intuitions, and that it is plausible that these intuitions may need revision. Finally,I intend to show that desert is an important moral and political concept, and that the disciplines of moral and political philosophy will be impoverished by the absence this concept. This absence, I will argue, is a natural consequence of the acceptance of the Rawlsian arguments.
- Full Text:
Designing and implementing a virtual reality interaction framework
- Authors: Rorke, Michael
- Date: 2000
- Subjects: Virtual reality , Computer simulation , Human-computer interaction , Computer graphics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4623 , http://hdl.handle.net/10962/d1006491 , Virtual reality , Computer simulation , Human-computer interaction , Computer graphics
- Description: Virtual Reality offers the possibility for humans to interact in a more natural way with the computer and its applications. Currently, Virtual Reality is used mainly in the field of visualisation where 3D graphics allow users to more easily view complex sets of data or structures. The field of interaction in Virtual Reality has been largely neglected due mainly to problems with input devices and equipment costs. Recent research has aimed to overcome these interaction problems, thereby creating a usable interaction platform for Virtual Reality. This thesis presents a background into the field of interaction in Virtual Reality. It goes on to propose a generic framework for the implementation of common interaction techniques into a homogeneous application development environment. This framework adds a new layer to the standard Virtual Reality toolkit – the interaction abstraction layer, or interactor layer. This separation is in line with current HCI practices. The interactor layer is further divided into specific sections – input component, interaction component, system component, intermediaries, entities and widgets. Each of these performs a specific function, with clearly defined interfaces between the different components to promote easy objectoriented implementation of the framework. The validity of the framework is shown in comparison with accepted taxonomies in the area of Virtual Reality interaction. Thus demonstrating that the framework covers all the relevant factors involved in the field. Furthermore, the thesis describes an implementation of this framework. The implementation was completed using the Rhodes University CoRgi Virtual Reality toolkit. Several postgraduate students in the Rhodes University Computer Science Department utilised the framework implementation to develop a set of case studies. These case studies demonstrate the practical use of the framework to create useful Virtual Reality applications, as well as demonstrating the generic nature of the framework and its extensibility to be able to handle new interaction techniques. Finally, the generic nature of the framework is further demonstrated by moving it from the standard CoRgi Virtual Reality toolkit, to a distributed version of this toolkit. The distributed implementation of the framework utilises the Common Object Request Broker Architecture (CORBA) to implement the distribution of the objects in the system. Using this distributed implementation, we are able to ascertain that CORBA is useful in the field of distributed real-time Virtual Reality, even taking into account the extra overhead introduced by the additional abstraction layer. We conclude from this thesis that it is important to abstract the interaction layer from the other layers of a Virtual Reality toolkit in order to provide a consistent interface to developers. We have shown that our framework is implementable and useful in the field, making it easier for developers to include interaction in their Virtual Reality applications. Our framework is able to handle all the current aspects of interaction in Virtual Reality, as well as being general enough to implement future interaction techniques. The framework is also applicable to different Virtual Reality toolkits and development platforms, making it ideal for developing general, cross-platform interactive Virtual Reality applications.
- Full Text:
- Authors: Rorke, Michael
- Date: 2000
- Subjects: Virtual reality , Computer simulation , Human-computer interaction , Computer graphics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4623 , http://hdl.handle.net/10962/d1006491 , Virtual reality , Computer simulation , Human-computer interaction , Computer graphics
- Description: Virtual Reality offers the possibility for humans to interact in a more natural way with the computer and its applications. Currently, Virtual Reality is used mainly in the field of visualisation where 3D graphics allow users to more easily view complex sets of data or structures. The field of interaction in Virtual Reality has been largely neglected due mainly to problems with input devices and equipment costs. Recent research has aimed to overcome these interaction problems, thereby creating a usable interaction platform for Virtual Reality. This thesis presents a background into the field of interaction in Virtual Reality. It goes on to propose a generic framework for the implementation of common interaction techniques into a homogeneous application development environment. This framework adds a new layer to the standard Virtual Reality toolkit – the interaction abstraction layer, or interactor layer. This separation is in line with current HCI practices. The interactor layer is further divided into specific sections – input component, interaction component, system component, intermediaries, entities and widgets. Each of these performs a specific function, with clearly defined interfaces between the different components to promote easy objectoriented implementation of the framework. The validity of the framework is shown in comparison with accepted taxonomies in the area of Virtual Reality interaction. Thus demonstrating that the framework covers all the relevant factors involved in the field. Furthermore, the thesis describes an implementation of this framework. The implementation was completed using the Rhodes University CoRgi Virtual Reality toolkit. Several postgraduate students in the Rhodes University Computer Science Department utilised the framework implementation to develop a set of case studies. These case studies demonstrate the practical use of the framework to create useful Virtual Reality applications, as well as demonstrating the generic nature of the framework and its extensibility to be able to handle new interaction techniques. Finally, the generic nature of the framework is further demonstrated by moving it from the standard CoRgi Virtual Reality toolkit, to a distributed version of this toolkit. The distributed implementation of the framework utilises the Common Object Request Broker Architecture (CORBA) to implement the distribution of the objects in the system. Using this distributed implementation, we are able to ascertain that CORBA is useful in the field of distributed real-time Virtual Reality, even taking into account the extra overhead introduced by the additional abstraction layer. We conclude from this thesis that it is important to abstract the interaction layer from the other layers of a Virtual Reality toolkit in order to provide a consistent interface to developers. We have shown that our framework is implementable and useful in the field, making it easier for developers to include interaction in their Virtual Reality applications. Our framework is able to handle all the current aspects of interaction in Virtual Reality, as well as being general enough to implement future interaction techniques. The framework is also applicable to different Virtual Reality toolkits and development platforms, making it ideal for developing general, cross-platform interactive Virtual Reality applications.
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Designing and making a difference: an exploration of technology education for rural school teachers
- Authors: Schäfer, Marc
- Date: 2000
- Subjects: Technology -- Study and teaching -- South Africa -- Eastern Cape Technology -- Study and teaching -- South Africa Rural schools -- South Africa -- Eastern Cape Education, Rural -- South Africa Winterberg schools trust
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1491 , http://hdl.handle.net/10962/d1003372
- Description: This qualitative study focused on a Technology Education programme for farm school teachers in the Eastern Cape province of South Africa. These teachers were faced with the challenge of incorporating Technology Education into their curriculum. The study was conducted within the context of an investigation into the conceptual nature of technology and an exploration of the theoretical underpinnings of Technology Education within both the international and South African context. Technology Education is being introduced into the South African curriculum against a background of educational transformation and the building of capacity to solve real life problems. This calls for a curriculum that will empower learners to be innovative, creative and skilled problem solvers. The introduction and incorporation of Technoiogy Education into the school curriculum poses a formidable challenge to farm schools in particular. Their unique history of neglect and legacy of underqualified teachers has made the introduction of any curriculum innovation process very difficult and challenging. This study analyses how an introductory Technology Education programme for farm school teachers in the Winterberg area of the Eastern Cape impacted~ on the teachers' professional and personal lives. It shows the importance of developing teclpological skills in conjunction with life skills in cO.ntributing to the empowerment, both in the work place and in the wider context, of rural school teachers. It highlights the need for supportive in-service education programmes and strengthens the argument for an integrative and mulitidisciplinary approach to the introduction of Technology Education in farm schools. Data was collected by means of questionnaires, interviews and photographs.
- Full Text:
- Authors: Schäfer, Marc
- Date: 2000
- Subjects: Technology -- Study and teaching -- South Africa -- Eastern Cape Technology -- Study and teaching -- South Africa Rural schools -- South Africa -- Eastern Cape Education, Rural -- South Africa Winterberg schools trust
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1491 , http://hdl.handle.net/10962/d1003372
- Description: This qualitative study focused on a Technology Education programme for farm school teachers in the Eastern Cape province of South Africa. These teachers were faced with the challenge of incorporating Technology Education into their curriculum. The study was conducted within the context of an investigation into the conceptual nature of technology and an exploration of the theoretical underpinnings of Technology Education within both the international and South African context. Technology Education is being introduced into the South African curriculum against a background of educational transformation and the building of capacity to solve real life problems. This calls for a curriculum that will empower learners to be innovative, creative and skilled problem solvers. The introduction and incorporation of Technoiogy Education into the school curriculum poses a formidable challenge to farm schools in particular. Their unique history of neglect and legacy of underqualified teachers has made the introduction of any curriculum innovation process very difficult and challenging. This study analyses how an introductory Technology Education programme for farm school teachers in the Winterberg area of the Eastern Cape impacted~ on the teachers' professional and personal lives. It shows the importance of developing teclpological skills in conjunction with life skills in cO.ntributing to the empowerment, both in the work place and in the wider context, of rural school teachers. It highlights the need for supportive in-service education programmes and strengthens the argument for an integrative and mulitidisciplinary approach to the introduction of Technology Education in farm schools. Data was collected by means of questionnaires, interviews and photographs.
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Development of the components of a low cost, distributed facial virtual conferencing system
- Authors: Panagou, Soterios
- Date: 2000 , 2011-11-10
- Subjects: Virtual computer systems , Virtual reality , Computer conferencing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4622 , http://hdl.handle.net/10962/d1006490 , Virtual computer systems , Virtual reality , Computer conferencing
- Description: This thesis investigates the development of a low cost, component based facial virtual conferencing system. The design is decomposed into an encoding phase and a decoding phase, which communicate with each other via a network connection. The encoding phase is composed of three components: model acquisition (which handles avatar generation), pose estimation and expression analysis. Audio is not considered part of the encoding and decoding process, and as such is not evaluated. The model acquisition component is implemented using a visual hull reconstruction algorithm that is able to reconstruct real-world objects using only sets of images of the object as input. The object to be reconstructed is assumed to lie in a bounding volume of voxels. The reconstruction process involves the following stages: - Space carving for basic shape extraction; - Isosurface extraction to remove voxels not part of the surface of the reconstruction; - Mesh connection to generate a closed, connected polyhedral mesh; - Texture generation. Texturing is achieved by Gouraud shading the reconstruction with a vertex colour map; - Mesh decimation to simplify the object. The original algorithm has complexity O(n), but suffers from an inability to reconstruct concave surfaces that do not form part of the visual hull of the object. A novel extension to this algorithm based on Normalised Cross Correlation (NCC) is proposed to overcome this problem. An extension to speed up traditional NCC evaluations is proposed which reduces the NCC search space from a 2D search problem down to a single evaluation. Pose estimation and expression analysis are performed by tracking six fiducial points on the face of a subject. A tracking algorithm is developed that uses Normalised Cross Correlation to facilitate robust tracking that is invariant to changing lighting conditions, rotations and scaling. Pose estimation involves the recovery of the head position and orientation through the tracking of the triangle formed by the subject's eyebrows and nose tip. A rule-based evaluation of points that are tracked around the subject's mouth forms the basis of the expression analysis. A user assisted feedback loop and caching mechanism is used to overcome tracking errors due to fast motion or occlusions. The NCC tracker is shown to achieve a tracking performance of 10 fps when tracking the six fiducial points. The decoding phase is divided into 3 tasks, namely: avatar movement, expression generation and expression management. Avatar movement is implemented using the base VR system. Expression generation is facilitated using a Vertex Interpolation Deformation method. A weighting system is proposed for expression management. Its function is to gradually transform from one expression to the next. The use of the vertex interpolation method allows real-time deformations of the avatar representation, achieving 16 fps when applied to a model consisting of 7500 vertices. An Expression Parameter Lookup Table (EPLT) facilitates an independent mapping between the two phases. It defines a list of generic expressions that are known to the system and associates an Expression ID with each one. For each generic expression, it relates the expression analysis rules for any subject with the expression generation parameters for any avatar model. The result is that facial expression replication between any subject and avatar combination can be performed by transferring only the Expression ID from the encoder application to the decoder application. The ideas developed in the thesis are demonstrated in an implementation using the CoRgi Virtual Reality system. It is shown that the virtual-conferencing application based on this design requires only a bandwidth of 2 Kbps. , Adobe Acrobat Pro 9.4.6 , Adobe Acrobat 9.46 Paper Capture Plug-in
- Full Text:
- Authors: Panagou, Soterios
- Date: 2000 , 2011-11-10
- Subjects: Virtual computer systems , Virtual reality , Computer conferencing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4622 , http://hdl.handle.net/10962/d1006490 , Virtual computer systems , Virtual reality , Computer conferencing
- Description: This thesis investigates the development of a low cost, component based facial virtual conferencing system. The design is decomposed into an encoding phase and a decoding phase, which communicate with each other via a network connection. The encoding phase is composed of three components: model acquisition (which handles avatar generation), pose estimation and expression analysis. Audio is not considered part of the encoding and decoding process, and as such is not evaluated. The model acquisition component is implemented using a visual hull reconstruction algorithm that is able to reconstruct real-world objects using only sets of images of the object as input. The object to be reconstructed is assumed to lie in a bounding volume of voxels. The reconstruction process involves the following stages: - Space carving for basic shape extraction; - Isosurface extraction to remove voxels not part of the surface of the reconstruction; - Mesh connection to generate a closed, connected polyhedral mesh; - Texture generation. Texturing is achieved by Gouraud shading the reconstruction with a vertex colour map; - Mesh decimation to simplify the object. The original algorithm has complexity O(n), but suffers from an inability to reconstruct concave surfaces that do not form part of the visual hull of the object. A novel extension to this algorithm based on Normalised Cross Correlation (NCC) is proposed to overcome this problem. An extension to speed up traditional NCC evaluations is proposed which reduces the NCC search space from a 2D search problem down to a single evaluation. Pose estimation and expression analysis are performed by tracking six fiducial points on the face of a subject. A tracking algorithm is developed that uses Normalised Cross Correlation to facilitate robust tracking that is invariant to changing lighting conditions, rotations and scaling. Pose estimation involves the recovery of the head position and orientation through the tracking of the triangle formed by the subject's eyebrows and nose tip. A rule-based evaluation of points that are tracked around the subject's mouth forms the basis of the expression analysis. A user assisted feedback loop and caching mechanism is used to overcome tracking errors due to fast motion or occlusions. The NCC tracker is shown to achieve a tracking performance of 10 fps when tracking the six fiducial points. The decoding phase is divided into 3 tasks, namely: avatar movement, expression generation and expression management. Avatar movement is implemented using the base VR system. Expression generation is facilitated using a Vertex Interpolation Deformation method. A weighting system is proposed for expression management. Its function is to gradually transform from one expression to the next. The use of the vertex interpolation method allows real-time deformations of the avatar representation, achieving 16 fps when applied to a model consisting of 7500 vertices. An Expression Parameter Lookup Table (EPLT) facilitates an independent mapping between the two phases. It defines a list of generic expressions that are known to the system and associates an Expression ID with each one. For each generic expression, it relates the expression analysis rules for any subject with the expression generation parameters for any avatar model. The result is that facial expression replication between any subject and avatar combination can be performed by transferring only the Expression ID from the encoder application to the decoder application. The ideas developed in the thesis are demonstrated in an implementation using the CoRgi Virtual Reality system. It is shown that the virtual-conferencing application based on this design requires only a bandwidth of 2 Kbps. , Adobe Acrobat Pro 9.4.6 , Adobe Acrobat 9.46 Paper Capture Plug-in
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Direct use values of secondary resources harvested from communal savannas in the Bushbuckridge lowveld, South Africa
- Shackleton, Charlie M, Shackleton, Sheona E
- Authors: Shackleton, Charlie M , Shackleton, Sheona E
- Date: 2000
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182798 , vital:43875 , xlink:href="https://www.cabdirect.org/cabdirect/abstract/20000614194"
- Description: This study reports on the direct use value of secondary resources harvested by rural communities in a savanna region of South Africa. Data pertaining to the use, amount and direct use value of 11 secondary resources were presented individually, along with a final composite value. Only five resources (fuelwood, construction wood, edible fruits, edible herbs, and medicinal plants), individually accounted for more than 10% of the total value per hectare (US$ 141), and together they represented over 94% of the total value per hectare. On a per household basis, only 3 of the 11 resources contributed 10% or more to the total direct use value (US$ 386 used at home and US$ 767 traded), and together contributed greater than 71% of the total direct use value per household. Two-thirds of the value per household was traded locally with other households or regionally, rather than consumed at home. The total value per hectare compared favourably with other land uses within the region, except for capital intensive enterprises. The returns to collecting and selling secondary resources were higher than those paid for local agricultural wage labour. The extraction rates of several of the secondary resources are probably sustainable but not for the more important ones such as fuelwood, construction wood and medicinal plants.
- Full Text:
- Authors: Shackleton, Charlie M , Shackleton, Sheona E
- Date: 2000
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182798 , vital:43875 , xlink:href="https://www.cabdirect.org/cabdirect/abstract/20000614194"
- Description: This study reports on the direct use value of secondary resources harvested by rural communities in a savanna region of South Africa. Data pertaining to the use, amount and direct use value of 11 secondary resources were presented individually, along with a final composite value. Only five resources (fuelwood, construction wood, edible fruits, edible herbs, and medicinal plants), individually accounted for more than 10% of the total value per hectare (US$ 141), and together they represented over 94% of the total value per hectare. On a per household basis, only 3 of the 11 resources contributed 10% or more to the total direct use value (US$ 386 used at home and US$ 767 traded), and together contributed greater than 71% of the total direct use value per household. Two-thirds of the value per household was traded locally with other households or regionally, rather than consumed at home. The total value per hectare compared favourably with other land uses within the region, except for capital intensive enterprises. The returns to collecting and selling secondary resources were higher than those paid for local agricultural wage labour. The extraction rates of several of the secondary resources are probably sustainable but not for the more important ones such as fuelwood, construction wood and medicinal plants.
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Discussion document prepared for COSATU Gender Conference
- NALEDI
- Authors: NALEDI
- Date: 2000
- Subjects: NALEDI
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/151190 , vital:39037
- Description: Despite the massive contribution women make around the world, they still fall into the category of the poorest and the most oppressed. Women have borne the brunt of the social costs of the changes in the world economy such as globalisation, increased international competition, structural adjustment and the deregulation of labour legislation. Massive technological advances have done little to benefit women around the world. In fact, in many instances it has actually increased their hardships. Multinational companies search the globe for areas that offer cheap labour and poor working conditions. Globally, women make up the bulk of the army of so-called “flexible”, cheap workers sought after by employers anxious to increase their profits. It is women who are mostly to be found in sweatshops and who are least likely to be organised. In South Africa, there is already a significant trend of homeworking in the clothing sector and casualisation in the retail and other sectors. And when they are organised into unions, women struggle to be recognised as leaders in those movements.
- Full Text:
- Authors: NALEDI
- Date: 2000
- Subjects: NALEDI
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/151190 , vital:39037
- Description: Despite the massive contribution women make around the world, they still fall into the category of the poorest and the most oppressed. Women have borne the brunt of the social costs of the changes in the world economy such as globalisation, increased international competition, structural adjustment and the deregulation of labour legislation. Massive technological advances have done little to benefit women around the world. In fact, in many instances it has actually increased their hardships. Multinational companies search the globe for areas that offer cheap labour and poor working conditions. Globally, women make up the bulk of the army of so-called “flexible”, cheap workers sought after by employers anxious to increase their profits. It is women who are mostly to be found in sweatshops and who are least likely to be organised. In South Africa, there is already a significant trend of homeworking in the clothing sector and casualisation in the retail and other sectors. And when they are organised into unions, women struggle to be recognised as leaders in those movements.
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Distributed authentication for resource control
- Authors: Burdis, Keith Robert
- Date: 2000
- Subjects: Computers -- Access control , Data protection , Computer networks -- Security measures , Electronic data processing departments -- Security measures
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4630 , http://hdl.handle.net/10962/d1006512 , Computers -- Access control , Data protection , Computer networks -- Security measures , Electronic data processing departments -- Security measures
- Description: This thesis examines distributed authentication in the process of controlling computing resources. We investigate user sign-on and two of the main authentication technologies that can be used to control a resource through authentication and providing additional security services. The problems with the existing sign-on scenario are that users have too much credential information to manage and are prompted for this information too often. Single Sign-On (SSO) is a viable solution to this problem if physical procedures are introduced to minimise the risks associated with its use. The Generic Security Services API (GSS-API) provides security services in a manner in- dependent of the environment in which these security services are used, encapsulating security functionality and insulating users from changes in security technology. The un- derlying security functionality is provided by GSS-API mechanisms. We developed the Secure Remote Password GSS-API Mechanism (SRPGM) to provide a mechanism that has low infrastructure requirements, is password-based and does not require the use of long-term asymmetric keys. We provide implementations of the Java GSS-API bindings and the LIPKEY and SRPGM GSS-API mechanisms. The Secure Authentication and Security Layer (SASL) provides security to connection- based Internet protocols. After finding deficiencies in existing SASL mechanisms we de- veloped the Secure Remote Password SASL mechanism (SRP-SASL) that provides strong password-based authentication and countermeasures against known attacks, while still be- ing simple and easy to implement. We provide implementations of the Java SASL binding and several SASL mechanisms, including SRP-SASL.
- Full Text:
- Authors: Burdis, Keith Robert
- Date: 2000
- Subjects: Computers -- Access control , Data protection , Computer networks -- Security measures , Electronic data processing departments -- Security measures
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4630 , http://hdl.handle.net/10962/d1006512 , Computers -- Access control , Data protection , Computer networks -- Security measures , Electronic data processing departments -- Security measures
- Description: This thesis examines distributed authentication in the process of controlling computing resources. We investigate user sign-on and two of the main authentication technologies that can be used to control a resource through authentication and providing additional security services. The problems with the existing sign-on scenario are that users have too much credential information to manage and are prompted for this information too often. Single Sign-On (SSO) is a viable solution to this problem if physical procedures are introduced to minimise the risks associated with its use. The Generic Security Services API (GSS-API) provides security services in a manner in- dependent of the environment in which these security services are used, encapsulating security functionality and insulating users from changes in security technology. The un- derlying security functionality is provided by GSS-API mechanisms. We developed the Secure Remote Password GSS-API Mechanism (SRPGM) to provide a mechanism that has low infrastructure requirements, is password-based and does not require the use of long-term asymmetric keys. We provide implementations of the Java GSS-API bindings and the LIPKEY and SRPGM GSS-API mechanisms. The Secure Authentication and Security Layer (SASL) provides security to connection- based Internet protocols. After finding deficiencies in existing SASL mechanisms we de- veloped the Secure Remote Password SASL mechanism (SRP-SASL) that provides strong password-based authentication and countermeasures against known attacks, while still be- ing simple and easy to implement. We provide implementations of the Java SASL binding and several SASL mechanisms, including SRP-SASL.
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Donor conditionalities and democratisation in Kenya, 1991-1997
- Authors: Muriuki, Irene
- Date: 2000
- Subjects: Economic assistance -- Political aspects -- Kenya , Democracy -- Kenya , Elections -- Kenya , Kenya -- Politics and government -- 1978-2002
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2812 , http://hdl.handle.net/10962/d1003022 , Economic assistance -- Political aspects -- Kenya , Democracy -- Kenya , Elections -- Kenya , Kenya -- Politics and government -- 1978-2002
- Description: The end of the Cold War and the collapse of the Soviet Union has encouraged democratisation in most parts of Africa. At the same time, Western donors' attitudes towards r~cipients of foreign aid have changed. This has resulted in a new practice, which attempts to force Third World states to move toward liberal democracy by conditioning lending on the holding of mUlti-party elections. In Africa this has resulted to the holding of multi-party elections. This study attempts to examine donor conditionalities and democratisation in Kenya by examining the results of 1992 and 1997 multi-party elections. Kenya attained independence from the British and ushered in a multi-party democracy in 1963. Since then, the country has undergone a full circle of political development, starting with a multi-party democracy at independence, through a one party dictatorship between 1982 and 1992 and back to a multi-party democracy in 1993. The need to satisfy foreign donors forced the leadership to amend Section 2(A) of Kenya' s constitution that had legalised single-party rule in 1982 thus allowing plural politics. The externally pressured transition to multi-party democracy though has resulted in increased corruption, state-sponsored ethnic violence, continued political authoritarianism and disastrous economic mismanagement of what was once considered a model for the continent. This study urges that Western donors should focus less on elections and more on the fostering of democratic institutions through breaking patterns of neo-patrimonial rule that have inforn1ed and continue to inform politics in Kenya. Political reforms have been resisted by the incumbency in the fear tha! they may curtail the power of the political leadership whose main objective has been to cling to power.
- Full Text:
- Authors: Muriuki, Irene
- Date: 2000
- Subjects: Economic assistance -- Political aspects -- Kenya , Democracy -- Kenya , Elections -- Kenya , Kenya -- Politics and government -- 1978-2002
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2812 , http://hdl.handle.net/10962/d1003022 , Economic assistance -- Political aspects -- Kenya , Democracy -- Kenya , Elections -- Kenya , Kenya -- Politics and government -- 1978-2002
- Description: The end of the Cold War and the collapse of the Soviet Union has encouraged democratisation in most parts of Africa. At the same time, Western donors' attitudes towards r~cipients of foreign aid have changed. This has resulted in a new practice, which attempts to force Third World states to move toward liberal democracy by conditioning lending on the holding of mUlti-party elections. In Africa this has resulted to the holding of multi-party elections. This study attempts to examine donor conditionalities and democratisation in Kenya by examining the results of 1992 and 1997 multi-party elections. Kenya attained independence from the British and ushered in a multi-party democracy in 1963. Since then, the country has undergone a full circle of political development, starting with a multi-party democracy at independence, through a one party dictatorship between 1982 and 1992 and back to a multi-party democracy in 1993. The need to satisfy foreign donors forced the leadership to amend Section 2(A) of Kenya' s constitution that had legalised single-party rule in 1982 thus allowing plural politics. The externally pressured transition to multi-party democracy though has resulted in increased corruption, state-sponsored ethnic violence, continued political authoritarianism and disastrous economic mismanagement of what was once considered a model for the continent. This study urges that Western donors should focus less on elections and more on the fostering of democratic institutions through breaking patterns of neo-patrimonial rule that have inforn1ed and continue to inform politics in Kenya. Political reforms have been resisted by the incumbency in the fear tha! they may curtail the power of the political leadership whose main objective has been to cling to power.
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Education for environmental literacy : towards participatory action research in the secondary school science curriculum in Lesotho
- Authors: Mokuku, Tsepo
- Date: 2000
- Subjects: Environmental education -- Lesotho , Science -- Study and teaching (Secondary) -- Lesotho
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1503 , http://hdl.handle.net/10962/d1003385 , Environmental education -- Lesotho , Science -- Study and teaching (Secondary) -- Lesotho
- Description: The dependency of educators in Lesotho on externally developed curriculum theories and concepts is fundamental to issues of relevance of the school curricula. This study set out to develop the meaning of environmental literacy in the context of three secondary schools and to explore appropriate teaching methods for the development of this concept in the science curriculum. The participatory action research process involved a team of four science teachers, including the researcher, in partnership with an environmental centre. We progressively developed the meamng of environmental literacy by monitoring teaching innovations in the classroom, holding meetings and workshops and attending conferences where we shared classroom findings and reflected on our emerging understandings based on classroom experiences. Data collection involved: audio-recording of classroom lessons, interviews with teachers and students, audio-visual recording, classroom observations and students' questionnaires. The research process made apparent the complex nature of the process of clarifying and developing environmental literacy in this context. Classroom actiyities planned to inform the team's understanding of the meaning of environmental literacy and develop appropriate teaching methods encountered constraints associated with the education system and the legacy of colonialism. These contextual constraints crystallised the need for the education system to be transformed in order to make schools more conducive environments for the gevelopment of students' environmental literacy. While initially teachers were reluctant to engage in critical reflection, the research process did encourage the team to revise and expand their understandings of both environmental literacy in the science classroom, and the action research itself. The emerging meaning of environmental literacy in this context and how it may be developed among students does not involve a definition with prescriptive, effective teaching methods, but provides insights and understandings gained by the participants in their engagement with a reflective process of reconslructing meaning. I have come to understand environmental literacy during the study to be a process that should draw strongly on the local knowledge and understandings into the science curriculum, through participatory process-based curriculum development models.
- Full Text:
- Authors: Mokuku, Tsepo
- Date: 2000
- Subjects: Environmental education -- Lesotho , Science -- Study and teaching (Secondary) -- Lesotho
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1503 , http://hdl.handle.net/10962/d1003385 , Environmental education -- Lesotho , Science -- Study and teaching (Secondary) -- Lesotho
- Description: The dependency of educators in Lesotho on externally developed curriculum theories and concepts is fundamental to issues of relevance of the school curricula. This study set out to develop the meaning of environmental literacy in the context of three secondary schools and to explore appropriate teaching methods for the development of this concept in the science curriculum. The participatory action research process involved a team of four science teachers, including the researcher, in partnership with an environmental centre. We progressively developed the meamng of environmental literacy by monitoring teaching innovations in the classroom, holding meetings and workshops and attending conferences where we shared classroom findings and reflected on our emerging understandings based on classroom experiences. Data collection involved: audio-recording of classroom lessons, interviews with teachers and students, audio-visual recording, classroom observations and students' questionnaires. The research process made apparent the complex nature of the process of clarifying and developing environmental literacy in this context. Classroom actiyities planned to inform the team's understanding of the meaning of environmental literacy and develop appropriate teaching methods encountered constraints associated with the education system and the legacy of colonialism. These contextual constraints crystallised the need for the education system to be transformed in order to make schools more conducive environments for the gevelopment of students' environmental literacy. While initially teachers were reluctant to engage in critical reflection, the research process did encourage the team to revise and expand their understandings of both environmental literacy in the science classroom, and the action research itself. The emerging meaning of environmental literacy in this context and how it may be developed among students does not involve a definition with prescriptive, effective teaching methods, but provides insights and understandings gained by the participants in their engagement with a reflective process of reconslructing meaning. I have come to understand environmental literacy during the study to be a process that should draw strongly on the local knowledge and understandings into the science curriculum, through participatory process-based curriculum development models.
- Full Text:
Effect of water temperature on the biogeography of South African estuarine fishes associated with the subtropical/warm temperate subtraction zone
- Maree, R C, Booth, Anthony J, Whitfield, Alan K
- Authors: Maree, R C , Booth, Anthony J , Whitfield, Alan K
- Date: 2000
- Language: English
- Type: text , Article
- Identifier: vital:7133 , http://hdl.handle.net/10962/d1011776
- Description: Estuarine biogeographical regions along the southeastern coast of South Africa were investigated in terms of fish distribution and abundance patterns, with particular emphasis on the role of water temperature in influencing these patterns. Qualitative and quantitative analyses were conducted upon the ichthyofaunal assemblages to determine whether the location of the subtropical/warm temperate boundary corresponds to that proposed by Whitfield.(n1) Analyses included the distribution ranges of species associated with estuaries according to presence/absence data, cluster analysis of gill net catches in eight estuaries along the southeastern coast and the relative proportion of tropical to temperate marine species within these eight systems. Quantitative analysis indicated that the ichthyofaunal biogeographical regions are indeed a reflection of water temperature regimes and that the subtropical/warm temperate boundary is located between the Great Kei and Mbashe estuaries. A strong negative correlation was found between the number of temperate fish species and the mean of the minimum monthly temperatures recorded in the systems studied. Qualitative analysis revealed that a barrier appears to exist in the vicinity of the Swartkops estuary, which prevents the westward migration of tropical 'vagrants'. The influence of the Agulhas Current along the east coast and its divergence from the coastline in the Algoa Bay region, as well as upwelling phenomena on the southeast and south coasts are identified as major factors that influence marine and estuarine temperature regimes and therefore the ichythyofauna of this region.
- Full Text: false
- Authors: Maree, R C , Booth, Anthony J , Whitfield, Alan K
- Date: 2000
- Language: English
- Type: text , Article
- Identifier: vital:7133 , http://hdl.handle.net/10962/d1011776
- Description: Estuarine biogeographical regions along the southeastern coast of South Africa were investigated in terms of fish distribution and abundance patterns, with particular emphasis on the role of water temperature in influencing these patterns. Qualitative and quantitative analyses were conducted upon the ichthyofaunal assemblages to determine whether the location of the subtropical/warm temperate boundary corresponds to that proposed by Whitfield.(n1) Analyses included the distribution ranges of species associated with estuaries according to presence/absence data, cluster analysis of gill net catches in eight estuaries along the southeastern coast and the relative proportion of tropical to temperate marine species within these eight systems. Quantitative analysis indicated that the ichthyofaunal biogeographical regions are indeed a reflection of water temperature regimes and that the subtropical/warm temperate boundary is located between the Great Kei and Mbashe estuaries. A strong negative correlation was found between the number of temperate fish species and the mean of the minimum monthly temperatures recorded in the systems studied. Qualitative analysis revealed that a barrier appears to exist in the vicinity of the Swartkops estuary, which prevents the westward migration of tropical 'vagrants'. The influence of the Agulhas Current along the east coast and its divergence from the coastline in the Algoa Bay region, as well as upwelling phenomena on the southeast and south coasts are identified as major factors that influence marine and estuarine temperature regimes and therefore the ichythyofauna of this region.
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Effect of wave exposure on growth and mortality rates of the mussel Perna perna: bottom up regulation of intertidal populations
- McQuaid, Christopher D, Lindsay, Tracy L
- Authors: McQuaid, Christopher D , Lindsay, Tracy L
- Date: 2000
- Language: English
- Type: Article
- Identifier: vital:6955 , http://hdl.handle.net/10962/d1011994
- Description: The effect of wave exposure on the growth of low-shore populations of Perna perna (Linnaeus) was determined using 3 independent approaches at 6 sites on the south coast of South Africa: (1) Individual marking; notches were filed on the growing edges of mussels in situ. After 111 d, growth from the mark to the new growing edge was measured. (2) Internal shell-growth bands; mussels from the mark recapture experiment were used to establish that growth bands are laid down tidally. Unmarked individuals were then used to measure growth over the last 60 tides. (3) Shepherd¹s length-composition analysis (SLCA); growth rates were determined from length-frequency distributions in 11 samples collected at 6 wk intervals over 15 mo. All 3 approaches showed that growth rate was approximately twice as fast on exposed as on sheltered shores (ANCOVA, p < 0.05 in all cases). Mean length for the first year of growth (averaged for the 3 methods) was 47 and 22 mm, respectively. There were, however, considerable differences among methods. Marking provided the lowest estimates of growth rates, and SLCA the highest. The mean mortality index (Z yr-1) was significantly higher and annual survival rate lower for exposed shores, indicating faster turnover under exposed conditions. Mean longevity on exposed shores (2.6 yr) was only one-third of estimated longevity on sheltered shores (6.7 yr). These findings show that degree of exposure has important interactions with growth and mortality of mussels on the low shore, and that these effects are independent of the effects of exposure on density. The findings also indicate strong bottom up regulation of mussel populations.
- Full Text:
- Authors: McQuaid, Christopher D , Lindsay, Tracy L
- Date: 2000
- Language: English
- Type: Article
- Identifier: vital:6955 , http://hdl.handle.net/10962/d1011994
- Description: The effect of wave exposure on the growth of low-shore populations of Perna perna (Linnaeus) was determined using 3 independent approaches at 6 sites on the south coast of South Africa: (1) Individual marking; notches were filed on the growing edges of mussels in situ. After 111 d, growth from the mark to the new growing edge was measured. (2) Internal shell-growth bands; mussels from the mark recapture experiment were used to establish that growth bands are laid down tidally. Unmarked individuals were then used to measure growth over the last 60 tides. (3) Shepherd¹s length-composition analysis (SLCA); growth rates were determined from length-frequency distributions in 11 samples collected at 6 wk intervals over 15 mo. All 3 approaches showed that growth rate was approximately twice as fast on exposed as on sheltered shores (ANCOVA, p < 0.05 in all cases). Mean length for the first year of growth (averaged for the 3 methods) was 47 and 22 mm, respectively. There were, however, considerable differences among methods. Marking provided the lowest estimates of growth rates, and SLCA the highest. The mean mortality index (Z yr-1) was significantly higher and annual survival rate lower for exposed shores, indicating faster turnover under exposed conditions. Mean longevity on exposed shores (2.6 yr) was only one-third of estimated longevity on sheltered shores (6.7 yr). These findings show that degree of exposure has important interactions with growth and mortality of mussels on the low shore, and that these effects are independent of the effects of exposure on density. The findings also indicate strong bottom up regulation of mussel populations.
- Full Text: