The Baylis-Hillman entrée to heterocyclic systems — the Rhodes contribution
- Authors: Kaye, Perry T
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6575 , http://hdl.handle.net/10962/d1004138
- Description: This review focuses on applications of the Baylis-Hillman reaction in the synthesis of various heterocyclic products, which include indolizines, chromenes, thiochromenes, coumarins and quinolines. Attention is also given to the mechanistic implications and the elaboration of various products to afford compounds with medicinal potential.
- Full Text:
- Authors: Kaye, Perry T
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6575 , http://hdl.handle.net/10962/d1004138
- Description: This review focuses on applications of the Baylis-Hillman reaction in the synthesis of various heterocyclic products, which include indolizines, chromenes, thiochromenes, coumarins and quinolines. Attention is also given to the mechanistic implications and the elaboration of various products to afford compounds with medicinal potential.
- Full Text:
The bells of Jamestown, South Atlantic Ocean
- Authors: Lewis, Colin A
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6177 , http://hdl.handle.net/10962/d1012370 , http://www.ringingworld.co.uk
- Description: Colin Lewis was Professor of Geography at Rhodes University, Grahamstown, South Africa from 1989 until his retirement at the end of 2007. In 1990, with the strong support of the incumbent Vice-Chancellor, Dr Derek Henderson, he instigated the Certificate in Change Ringing (Church Bell Ringing) in the Rhodes University Department of Music and Musicology - the first such course to be offered in Africa. Since that date he has lectured in the basic theory, and taught the practice of change ringing. He is the Ringing Master of the Cathedral of St Michael and St George, Grahamstown, South Africa.
- Full Text:
- Authors: Lewis, Colin A
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6177 , http://hdl.handle.net/10962/d1012370 , http://www.ringingworld.co.uk
- Description: Colin Lewis was Professor of Geography at Rhodes University, Grahamstown, South Africa from 1989 until his retirement at the end of 2007. In 1990, with the strong support of the incumbent Vice-Chancellor, Dr Derek Henderson, he instigated the Certificate in Change Ringing (Church Bell Ringing) in the Rhodes University Department of Music and Musicology - the first such course to be offered in Africa. Since that date he has lectured in the basic theory, and taught the practice of change ringing. He is the Ringing Master of the Cathedral of St Michael and St George, Grahamstown, South Africa.
- Full Text:
The bells of north western Transkei, South Africa
- Authors: Lewis, Colin A
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6183 , http://hdl.handle.net/10962/d1012379 , http://www.ringingworld.co.uk
- Description: [From Introduction] Few of the many visitors to South Africa journey into the isolated country east of Queenstown and south of Elliot, in the rugged basin and range country of that part of the Transkei. That is largely a forgotten land, hidden south of the Mount Arthur range from the rolling grasslands of the Drakensburg foothills and their commercial farms. , Colin Lewis was Professor of Geography at Rhodes University, Grahamstown, South Africa from 1989 until his retirement at the end of 2007. In 1990, with the strong support of the incumbent Vice-Chancellor, Dr Derek Henderson, he instigated the Certificate in Change Ringing (Church Bell Ringing) in the Rhodes University Department of Music and Musicology - the first such course to be offered in Africa. Since that date he has lectured in the basic theory, and taught the practice of change ringing. He is the Ringing Master of the Cathedral of St Michael and St George, Grahamstown, South Africa.
- Full Text:
- Authors: Lewis, Colin A
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6183 , http://hdl.handle.net/10962/d1012379 , http://www.ringingworld.co.uk
- Description: [From Introduction] Few of the many visitors to South Africa journey into the isolated country east of Queenstown and south of Elliot, in the rugged basin and range country of that part of the Transkei. That is largely a forgotten land, hidden south of the Mount Arthur range from the rolling grasslands of the Drakensburg foothills and their commercial farms. , Colin Lewis was Professor of Geography at Rhodes University, Grahamstown, South Africa from 1989 until his retirement at the end of 2007. In 1990, with the strong support of the incumbent Vice-Chancellor, Dr Derek Henderson, he instigated the Certificate in Change Ringing (Church Bell Ringing) in the Rhodes University Department of Music and Musicology - the first such course to be offered in Africa. Since that date he has lectured in the basic theory, and taught the practice of change ringing. He is the Ringing Master of the Cathedral of St Michael and St George, Grahamstown, South Africa.
- Full Text:
The development of a geographic information system (GIS) as a mariculture sector planning tool in South Africa
- Authors: Shiran-Klotz, Imran
- Date: 2004
- Subjects: Geographic information systems -- South Africa , Fishery management -- Geographic information systems -- South Africa , Mariculture -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5337 , http://hdl.handle.net/10962/d1005870 , Geographic information systems -- South Africa , Fishery management -- Geographic information systems -- South Africa , Mariculture -- South Africa
- Description: The South African coastline has a high potential for mariculture development, particularly in land-based systems, due to excellent water quality, good infrastructure, and relatively cheap land in certain areas. Development of mariculture however, has been slow primarily due to the absence of a national sector development plan to coordinate contribution to development by government, industry and academia. Recent mariculture development plans however, supported by government commitment to stimulate coastal development, offers new opportunity for the sector's growth. These new sector development plans require a multi-disciplinary intensive information base with a strong regional and national spatial component. Geographic Information System (GIS) is a spatial analytical tool, which is capable of handling such large coastal databases and analysing them. Nevertheless, many mariculture GIS planning applications, often developed in isolation and with limited practical use for decision makers, highlighted the need to develop GIS in relation to the mariculture sector development plan. Hence, the aim of this study was to develop and evaluate a GIS for the national and regional mariculture sector planning process in South Africa, in order to identify potentially suitable areas along the South African coastline for mariculture operations. The GIS development in this study was based on the mariculture planning approach developed by PAP/RAe (1996), which recognizes the variations of scales in mariculture planning. Three case studies, representing the diversity of the South African sector plan, were selected to develop the GIS. They included: a national suitability analysis for all land-based culture systems, a specific national analysis on abalone ranching, and a detailed regional analysis of land-based culture and abalone ranching along the Namaqualand coastline. The GIS was developed separately for each case study based on a strategy consisting of six main phases, including: identification of project requirements, developing analytical framework, selection and location of data sources, organization and manipulation of data, analysing data and verifying and evaluation of the outputs. Biophysical, coastal use, and infrastructure criteria were collected, sorted and analysed to identify development constraints. Based on a set of conditions, and Boolean logic and arithmetic operations, unsuitable areas were identified and eliminated. Main constraints for national land-based development included competition over space along KwaZuluNatal Province coastline and restricted access to the coast along the south region of the Northern Cape Province, Wild Coast along the Eastern Cape Province, and Maputaland along KwaZulu-Natal Province. Ten areas along the country coastline were therefore identified as potentially suitable for land-based mariculture. Furthermore, South African abalone ranching potential was found to be limited mostly along the Western and Northern Cape Province's coastline due to the high risk of Paralytic Shellfish Poison (PSP) occurrences, alternative resource use and activities such as commercial fishery, poaching, and conservation. Hence, a total of nine areas along the Northern Cape, Western Cape, and Eastern Cape coastlines were identified as premier areas for abalone ranching. The regional study along the Namaqualand coastline revealed potential conflict between mining activity and mariculture development due to security issues and restricted access to the coast. Land-based mariculture development was confined to the four main coastal urban areas. The highest potential for land-based mariculture was along Port Nolloth and Kleinsee coastlines, whereas marine-based (i.e. abalone ranching) potential was poor along the north part of the coast due to intense marine mining activities, restricted access to the coast, and low kelp bed density. High potential abalone ranching areas were identified south to Kleinsee, and around Port Nolloth. Potential conflict with marine mining activity was minimal since it was localised and not related to kelp bed locations. It was concluded that GIS is a relevant and compatible tool for South African mariculture sector planning. However, future development of GIS as integrated planning tool in mariculture and coastal planning, requires updated spatial data (e.g. recreational activity), and continued interaction among project planners, mariculture specialists and GIS analysts.
- Full Text:
- Authors: Shiran-Klotz, Imran
- Date: 2004
- Subjects: Geographic information systems -- South Africa , Fishery management -- Geographic information systems -- South Africa , Mariculture -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5337 , http://hdl.handle.net/10962/d1005870 , Geographic information systems -- South Africa , Fishery management -- Geographic information systems -- South Africa , Mariculture -- South Africa
- Description: The South African coastline has a high potential for mariculture development, particularly in land-based systems, due to excellent water quality, good infrastructure, and relatively cheap land in certain areas. Development of mariculture however, has been slow primarily due to the absence of a national sector development plan to coordinate contribution to development by government, industry and academia. Recent mariculture development plans however, supported by government commitment to stimulate coastal development, offers new opportunity for the sector's growth. These new sector development plans require a multi-disciplinary intensive information base with a strong regional and national spatial component. Geographic Information System (GIS) is a spatial analytical tool, which is capable of handling such large coastal databases and analysing them. Nevertheless, many mariculture GIS planning applications, often developed in isolation and with limited practical use for decision makers, highlighted the need to develop GIS in relation to the mariculture sector development plan. Hence, the aim of this study was to develop and evaluate a GIS for the national and regional mariculture sector planning process in South Africa, in order to identify potentially suitable areas along the South African coastline for mariculture operations. The GIS development in this study was based on the mariculture planning approach developed by PAP/RAe (1996), which recognizes the variations of scales in mariculture planning. Three case studies, representing the diversity of the South African sector plan, were selected to develop the GIS. They included: a national suitability analysis for all land-based culture systems, a specific national analysis on abalone ranching, and a detailed regional analysis of land-based culture and abalone ranching along the Namaqualand coastline. The GIS was developed separately for each case study based on a strategy consisting of six main phases, including: identification of project requirements, developing analytical framework, selection and location of data sources, organization and manipulation of data, analysing data and verifying and evaluation of the outputs. Biophysical, coastal use, and infrastructure criteria were collected, sorted and analysed to identify development constraints. Based on a set of conditions, and Boolean logic and arithmetic operations, unsuitable areas were identified and eliminated. Main constraints for national land-based development included competition over space along KwaZuluNatal Province coastline and restricted access to the coast along the south region of the Northern Cape Province, Wild Coast along the Eastern Cape Province, and Maputaland along KwaZulu-Natal Province. Ten areas along the country coastline were therefore identified as potentially suitable for land-based mariculture. Furthermore, South African abalone ranching potential was found to be limited mostly along the Western and Northern Cape Province's coastline due to the high risk of Paralytic Shellfish Poison (PSP) occurrences, alternative resource use and activities such as commercial fishery, poaching, and conservation. Hence, a total of nine areas along the Northern Cape, Western Cape, and Eastern Cape coastlines were identified as premier areas for abalone ranching. The regional study along the Namaqualand coastline revealed potential conflict between mining activity and mariculture development due to security issues and restricted access to the coast. Land-based mariculture development was confined to the four main coastal urban areas. The highest potential for land-based mariculture was along Port Nolloth and Kleinsee coastlines, whereas marine-based (i.e. abalone ranching) potential was poor along the north part of the coast due to intense marine mining activities, restricted access to the coast, and low kelp bed density. High potential abalone ranching areas were identified south to Kleinsee, and around Port Nolloth. Potential conflict with marine mining activity was minimal since it was localised and not related to kelp bed locations. It was concluded that GIS is a relevant and compatible tool for South African mariculture sector planning. However, future development of GIS as integrated planning tool in mariculture and coastal planning, requires updated spatial data (e.g. recreational activity), and continued interaction among project planners, mariculture specialists and GIS analysts.
- Full Text:
The development of a toxicity database using freshwater macroinvertebrates, and its application to the protection of South African water resources
- Palmer, Carolyn G, Muller, Wilhelmine J, Gordon, Andrew K, Scherman, Patricia A, Davies-Coleman, Heather D, Pakhomova, L, de Kock, E
- Authors: Palmer, Carolyn G , Muller, Wilhelmine J , Gordon, Andrew K , Scherman, Patricia A , Davies-Coleman, Heather D , Pakhomova, L , de Kock, E
- Date: 2004
- Language: English
- Type: text , Article
- Identifier: vital:7073 , http://hdl.handle.net/10962/d1009528
- Description: There is a growing international trend towards the protection of freshwater resources from pollution by imposing instream guidelines and specified waste-discharge conditions. Current methods for devising freshwater quality guidelines are based on species sensitivity distributions (SSDs) that are used to identify pollutant concentrations, ensuring the protection of a modelled percentage of species (95% protection is a common goal). SSDs are derived from the toxicity test results of as many taxa as possible for each polluting substance. Waste-discharge licences can be for single substances, specified in terms of chemical concentrations, and derived in conjunction with instream guidelines; or for complex mixtures, specified in terms of toxic units. In both cases toxicity test results are the core data used. The emphasis on SSDs calls into question the species constituting the test populations. It is likely that SSDs based in part on the responses of local organisms will achieve superior site-specific ecological protection. Until the early 1990s, there were very few data on the tolerances of South African freshwater organisms. In the intervening decade, the Unilever Centre for Environmental Water Quality at Rhodes University has developed a toxicity database that, to date, records the responses of 21 South African freshwater taxa to 26 single-substance pollutants or mixtures. This is the most comprehensive database of South African toxicity responses available and has been used in the drawing up of methods and guidelines to protect water resources. This paper aims to make these data available and to describe applications of the data using selected case studies.
- Full Text:
- Authors: Palmer, Carolyn G , Muller, Wilhelmine J , Gordon, Andrew K , Scherman, Patricia A , Davies-Coleman, Heather D , Pakhomova, L , de Kock, E
- Date: 2004
- Language: English
- Type: text , Article
- Identifier: vital:7073 , http://hdl.handle.net/10962/d1009528
- Description: There is a growing international trend towards the protection of freshwater resources from pollution by imposing instream guidelines and specified waste-discharge conditions. Current methods for devising freshwater quality guidelines are based on species sensitivity distributions (SSDs) that are used to identify pollutant concentrations, ensuring the protection of a modelled percentage of species (95% protection is a common goal). SSDs are derived from the toxicity test results of as many taxa as possible for each polluting substance. Waste-discharge licences can be for single substances, specified in terms of chemical concentrations, and derived in conjunction with instream guidelines; or for complex mixtures, specified in terms of toxic units. In both cases toxicity test results are the core data used. The emphasis on SSDs calls into question the species constituting the test populations. It is likely that SSDs based in part on the responses of local organisms will achieve superior site-specific ecological protection. Until the early 1990s, there were very few data on the tolerances of South African freshwater organisms. In the intervening decade, the Unilever Centre for Environmental Water Quality at Rhodes University has developed a toxicity database that, to date, records the responses of 21 South African freshwater taxa to 26 single-substance pollutants or mixtures. This is the most comprehensive database of South African toxicity responses available and has been used in the drawing up of methods and guidelines to protect water resources. This paper aims to make these data available and to describe applications of the data using selected case studies.
- Full Text:
The doctrine of duress in the law of contract and unjustified enrichment in South Africa
- Authors: Glover, Graham Brian
- Date: 2004
- Subjects: Contracts -- South Africa , Duress (Law) -- South Africa , Remedies (Law) -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3672 , http://hdl.handle.net/10962/d1003187 , Contracts -- South Africa , Duress (Law) -- South Africa , Remedies (Law) -- South Africa
- Description: This thesis analyses the doctrine of duress and its application in the law of contract and unjustified enrichment in South Africa. Following an initial examination of the historical development of the doctrine from its roots in Roman and Roman-Dutch law, the study focuses on the current legal position in the two areas of law under review, identifies the substantive and formal deficiencies in the current approach, and suggests, using comparative authorities, how the law might be developed. As far as the law of contract is concerned, after exposing the difficulties inherent in the current approach, and placing the doctrine in its proper context in the South African law of contract generally, it is argued that the duress doctrine finds its juridical basis in the principle of good faith. A more modern and coherent test for duress is then proposed: one that concentrates on the question whether an illegitimate threat was made, which induced a contract in that it left the other person no reasonable choice but to succumb to the proposal. Additionally, the need for South African contract law to recognise and deal with cases of economic duress is emphasised. The study then shifts to an examination of the position in situations where non-contractual performances have occurred under duress: cases that are decided in terms of the principles of the law of unjustified enrichment. The current position is reviewed, and it is shown that the approach to duress cases is substantially different to the approach that applies in contract. An attempt is made to reconcile this problem. From a structural perspective, the nature and application of the relevant enrichment action where a non-contractual performance is made under duress (the condictio indebiti) is also investigated, in the light of approaches to enrichment adopted in both Germany and England, in an attempt to make better sense of this enrichment action in the South African context. The study closes with an analysis of the various contractual, delictual and enrichment remedies that are available once a case of duress has been proved.
- Full Text:
- Authors: Glover, Graham Brian
- Date: 2004
- Subjects: Contracts -- South Africa , Duress (Law) -- South Africa , Remedies (Law) -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3672 , http://hdl.handle.net/10962/d1003187 , Contracts -- South Africa , Duress (Law) -- South Africa , Remedies (Law) -- South Africa
- Description: This thesis analyses the doctrine of duress and its application in the law of contract and unjustified enrichment in South Africa. Following an initial examination of the historical development of the doctrine from its roots in Roman and Roman-Dutch law, the study focuses on the current legal position in the two areas of law under review, identifies the substantive and formal deficiencies in the current approach, and suggests, using comparative authorities, how the law might be developed. As far as the law of contract is concerned, after exposing the difficulties inherent in the current approach, and placing the doctrine in its proper context in the South African law of contract generally, it is argued that the duress doctrine finds its juridical basis in the principle of good faith. A more modern and coherent test for duress is then proposed: one that concentrates on the question whether an illegitimate threat was made, which induced a contract in that it left the other person no reasonable choice but to succumb to the proposal. Additionally, the need for South African contract law to recognise and deal with cases of economic duress is emphasised. The study then shifts to an examination of the position in situations where non-contractual performances have occurred under duress: cases that are decided in terms of the principles of the law of unjustified enrichment. The current position is reviewed, and it is shown that the approach to duress cases is substantially different to the approach that applies in contract. An attempt is made to reconcile this problem. From a structural perspective, the nature and application of the relevant enrichment action where a non-contractual performance is made under duress (the condictio indebiti) is also investigated, in the light of approaches to enrichment adopted in both Germany and England, in an attempt to make better sense of this enrichment action in the South African context. The study closes with an analysis of the various contractual, delictual and enrichment remedies that are available once a case of duress has been proved.
- Full Text:
The early reception of Hill of Fools
- Authors: Wright, Laurence
- Date: 2004
- Language: English
- Type: text , article
- Identifier: vital:7040 , http://hdl.handle.net/10962/d1007379 , http://hdl.handle.net/10520/EJC47864
- Description: preprint , The early reception of Peteni’s novel is interesting because it illustrates the mind-sets and critical assumptions of those who first mediated the novel to different readerships. The book initially caused little stir either in South Africa or abroad, and it has made its way quietly in later years in no small part due to support from set-work prescription committees, and its translation into other media, radio and television. A one-off novel by an unknown writer is unlikely to gather critical momentum in international discussion, and the book has been more often noticed in academic studies focused on the Xhosa novel, some of which barely register that the work was first written in English. However, today it is certainly among the novels most widely-read by ordinary South Africans, not only those from the Eastern Cape, but for among many throughout the country who encountered it at school.
- Full Text:
- Authors: Wright, Laurence
- Date: 2004
- Language: English
- Type: text , article
- Identifier: vital:7040 , http://hdl.handle.net/10962/d1007379 , http://hdl.handle.net/10520/EJC47864
- Description: preprint , The early reception of Peteni’s novel is interesting because it illustrates the mind-sets and critical assumptions of those who first mediated the novel to different readerships. The book initially caused little stir either in South Africa or abroad, and it has made its way quietly in later years in no small part due to support from set-work prescription committees, and its translation into other media, radio and television. A one-off novel by an unknown writer is unlikely to gather critical momentum in international discussion, and the book has been more often noticed in academic studies focused on the Xhosa novel, some of which barely register that the work was first written in English. However, today it is certainly among the novels most widely-read by ordinary South Africans, not only those from the Eastern Cape, but for among many throughout the country who encountered it at school.
- Full Text:
The ecology and control of small hive beetles (Aethina tumida Murray)
- Authors: Ellis, James Douglas
- Date: 2004
- Subjects: Bee culture , Bee culture -- United States , Nitidulidae , Beetles -- Ecology , Beetles -- Control
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5917 , http://hdl.handle.net/10962/d1016253
- Description: The small hive beetle (Aethina tumida Murray) is an endemic scavenger in colonies of honey bee (Apis mellifera L.) subspecies inhabiting sub-Saharan Africa. The beetle only occasionally damages host colonies in its native range and such damage is usually restricted to weakened/diseased colonies or is associated with after absconding events due to behavioral resistance mechanisms of its host. The beetle has recently been introduced into North America and Australia where populations of managed subspecies of European honey bees have proven highly susceptible to beetle depredation. Beetles are able to reproduce in large numbers in European colonies and their larvae weaken colonies by eating honey, pollen, and bee brood. Further, adult and larval defecation is thought to promote the fermentation of honey and large populations of beetles can cause European colonies to abscond, both resulting in additional colony damage. The economic losses attributed to the beetle since its introduction into the United States have been estimated in millions of US dollars. Although beetles feed on foodstuffs found within colonies, experiments in vitro show that they can also complete entire life cycles on fruit. Regardless, they reproduce best on diets of honey, pollen, and bee brood. After feeding, beetle larvae exit the colony and burrow into the ground where they pupate. Neither soil type nor density affects a beetle’s ability to successfully pupate. Instead, successful pupation appears to be closely tied to soil moisture. African subspecies of honey bees employ a complicated scheme of confinement (aggressive behavior toward and guarding of beetles) to limit beetle reproduction in a colony. Despite being confined away from food, adult beetles are able to solicit food and feed from the mouths of their honey bee guards. Remarkably, beetle-naïve European honey bees also confine beetles and this behavior is quantitatively similar to that in African bees. If confinement efforts fail, beetles access the combs where they feed and reproduce. Two modes of beetle oviposition in sealed bee brood have been identified. In the first mode, beetles bite holes in the cappings of cells and oviposit on the pupa contained within. In the second mode, beetles enter empty cells, bite a hole in the wall of the cell, and oviposit on the brood in the adjacent cell. Despite this, African bees detect and remove all of the infected brood (hygienic behavior). Similarly, European bees can detect and remove brood that has been oviposited on by beetles. Enhancing the removal rate of infected brood in European colonies through selective breeding may achieve genetic control of beetles. Additional avenues of control were tested for efficacy against beetles. Reducing colony entrances slowed beetle ingress but the efficacy of this method probably depends on other factors. Further, the mortality of beetle pupae was higher when contacting species of the fungus Aspergillus than when not, making biological control an option. Regardless, no control tested to date proved efficacious at the level needed by beekeepers so an integrated approach to controlling beetles remains preferred. The amalgamation of the data presented in this dissertation contributed to a discussion on the beetle’s ecological niche, ability to impact honey bee colonies in ways never considered, and the ability to predict the beetle’s spread and impact globally.
- Full Text:
- Authors: Ellis, James Douglas
- Date: 2004
- Subjects: Bee culture , Bee culture -- United States , Nitidulidae , Beetles -- Ecology , Beetles -- Control
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5917 , http://hdl.handle.net/10962/d1016253
- Description: The small hive beetle (Aethina tumida Murray) is an endemic scavenger in colonies of honey bee (Apis mellifera L.) subspecies inhabiting sub-Saharan Africa. The beetle only occasionally damages host colonies in its native range and such damage is usually restricted to weakened/diseased colonies or is associated with after absconding events due to behavioral resistance mechanisms of its host. The beetle has recently been introduced into North America and Australia where populations of managed subspecies of European honey bees have proven highly susceptible to beetle depredation. Beetles are able to reproduce in large numbers in European colonies and their larvae weaken colonies by eating honey, pollen, and bee brood. Further, adult and larval defecation is thought to promote the fermentation of honey and large populations of beetles can cause European colonies to abscond, both resulting in additional colony damage. The economic losses attributed to the beetle since its introduction into the United States have been estimated in millions of US dollars. Although beetles feed on foodstuffs found within colonies, experiments in vitro show that they can also complete entire life cycles on fruit. Regardless, they reproduce best on diets of honey, pollen, and bee brood. After feeding, beetle larvae exit the colony and burrow into the ground where they pupate. Neither soil type nor density affects a beetle’s ability to successfully pupate. Instead, successful pupation appears to be closely tied to soil moisture. African subspecies of honey bees employ a complicated scheme of confinement (aggressive behavior toward and guarding of beetles) to limit beetle reproduction in a colony. Despite being confined away from food, adult beetles are able to solicit food and feed from the mouths of their honey bee guards. Remarkably, beetle-naïve European honey bees also confine beetles and this behavior is quantitatively similar to that in African bees. If confinement efforts fail, beetles access the combs where they feed and reproduce. Two modes of beetle oviposition in sealed bee brood have been identified. In the first mode, beetles bite holes in the cappings of cells and oviposit on the pupa contained within. In the second mode, beetles enter empty cells, bite a hole in the wall of the cell, and oviposit on the brood in the adjacent cell. Despite this, African bees detect and remove all of the infected brood (hygienic behavior). Similarly, European bees can detect and remove brood that has been oviposited on by beetles. Enhancing the removal rate of infected brood in European colonies through selective breeding may achieve genetic control of beetles. Additional avenues of control were tested for efficacy against beetles. Reducing colony entrances slowed beetle ingress but the efficacy of this method probably depends on other factors. Further, the mortality of beetle pupae was higher when contacting species of the fungus Aspergillus than when not, making biological control an option. Regardless, no control tested to date proved efficacious at the level needed by beekeepers so an integrated approach to controlling beetles remains preferred. The amalgamation of the data presented in this dissertation contributed to a discussion on the beetle’s ecological niche, ability to impact honey bee colonies in ways never considered, and the ability to predict the beetle’s spread and impact globally.
- Full Text:
The effect of commercialisation, privatisation and liberalisation on universal access in South Africa
- Gardner, Sean Patrick Newell
- Authors: Gardner, Sean Patrick Newell
- Date: 2004
- Subjects: Telkom (Firm : South Africa) , Telecommunication , Telecommunication -- South Africa , Privatization -- South Africa , Trade regulation -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3431 , http://hdl.handle.net/10962/d1002885 , Telkom (Firm : South Africa) , Telecommunication , Telecommunication -- South Africa , Privatization -- South Africa , Trade regulation -- South Africa
- Description: From the 1990s onwards, significant developments have occurred in the international telecommunications sector that have affected the South African telecommunications industry and peoples’ access to the network. Rapid developments in Information and Communication Technologies and the reorganisation of telecommunications operators through commercialisation, privatisation and the effects of market liberalisation have resulted in monopoly operators moving away from their public service mandates. Globalisation and adherence to World Trade Organisation rules are causing operators to rebalance their tariffs closer to cost. Long-distance rates are decreasing while the cost of local calls is increasing. High-end users of telecommunications services are benefiting while low-end, largely residential users are being priced off the network. The end result is a negative effect on universal access to telecommunications services. This study examines the extent to which commercialisation, privatisation and liberalization are affecting the provision of telecommunications services and the government’s goal of achieving universal access in South Africa. Qualitative research methods were utilised to establish that the state owned operator, Telkom, has transformed itself from a public service operator to one that is fully commercialised and prepared for an Initial Public Offering and competition. Telkom no longer attempts to ensure that its tariffs are affordable for all people. However, positive developments presented themselves in the form of an increasingly competent regulator, a reorganised and dedicated Universal Service Agency, and the popularity of cellular telephony. The primary discovery of this study is that the liberalisation of the South African telecommunications sector cannot be assumed to have a negative effect on the provision of service. This study finds that liberalisation will most likely benefit the country through the role out of new infrastructure, the provision of new services and ultimately the reduction of those services themselves. In order for universal access to be achieved in this country the study recommends that the resources of the Independent Communications Authority of South Africa be enhanced to enable the regulator oversee the industry effectively. Secondly, the Universal Service Agency must provide clear definitions of universal access and universal service as well as manage the Universal Service Fund with greater efficiency. Lastly, the two bodies mentioned above must ensure that services are affordable for all people of this country.
- Full Text:
- Authors: Gardner, Sean Patrick Newell
- Date: 2004
- Subjects: Telkom (Firm : South Africa) , Telecommunication , Telecommunication -- South Africa , Privatization -- South Africa , Trade regulation -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3431 , http://hdl.handle.net/10962/d1002885 , Telkom (Firm : South Africa) , Telecommunication , Telecommunication -- South Africa , Privatization -- South Africa , Trade regulation -- South Africa
- Description: From the 1990s onwards, significant developments have occurred in the international telecommunications sector that have affected the South African telecommunications industry and peoples’ access to the network. Rapid developments in Information and Communication Technologies and the reorganisation of telecommunications operators through commercialisation, privatisation and the effects of market liberalisation have resulted in monopoly operators moving away from their public service mandates. Globalisation and adherence to World Trade Organisation rules are causing operators to rebalance their tariffs closer to cost. Long-distance rates are decreasing while the cost of local calls is increasing. High-end users of telecommunications services are benefiting while low-end, largely residential users are being priced off the network. The end result is a negative effect on universal access to telecommunications services. This study examines the extent to which commercialisation, privatisation and liberalization are affecting the provision of telecommunications services and the government’s goal of achieving universal access in South Africa. Qualitative research methods were utilised to establish that the state owned operator, Telkom, has transformed itself from a public service operator to one that is fully commercialised and prepared for an Initial Public Offering and competition. Telkom no longer attempts to ensure that its tariffs are affordable for all people. However, positive developments presented themselves in the form of an increasingly competent regulator, a reorganised and dedicated Universal Service Agency, and the popularity of cellular telephony. The primary discovery of this study is that the liberalisation of the South African telecommunications sector cannot be assumed to have a negative effect on the provision of service. This study finds that liberalisation will most likely benefit the country through the role out of new infrastructure, the provision of new services and ultimately the reduction of those services themselves. In order for universal access to be achieved in this country the study recommends that the resources of the Independent Communications Authority of South Africa be enhanced to enable the regulator oversee the industry effectively. Secondly, the Universal Service Agency must provide clear definitions of universal access and universal service as well as manage the Universal Service Fund with greater efficiency. Lastly, the two bodies mentioned above must ensure that services are affordable for all people of this country.
- Full Text:
The effect of diet type and feeding rate on growth, morphological development and behaviour of larval and juvenile goldfish Carassius auratus (L.)
- Authors: Paulet, Timothy Guy
- Date: 2004
- Subjects: Goldfish -- Growth , Goldfish -- Nutrition , Goldfish -- Development , Goldfish -- Larvae
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5271 , http://hdl.handle.net/10962/d1005115 , Goldfish -- Growth , Goldfish -- Nutrition , Goldfish -- Development , Goldfish -- Larvae
- Description: Intensive grow-out of goldfish, Carassius auratus (L.), larvae and juveniles in closed recirculating systems requires the control of environmental conditions and feeding. This study investigated the effect of different diets, environmental condition and feeding level on growth, development and survival of goldfish larvae and juveniles. Prey preference for Artemia nauplii or decapsulated Artemia cysts as well as agonistic behaviour was recorded. The micrometer device used to measure mouth-gape was shown to produce accurate measurements which could be used to estimate the maximal particle size that can be ingested by goldfish larvae of a particular age. Goldfish completed metamorphosis earlier with an increased feeding level of Artemia cysts and by making the cysts more accessible to the fish using up-welling water movement. Morphometric plasticity in goldfish larvae was exhibited within two weeks of growth and it may be possible to induce changes in morphology by manipulating diet and rearing environment. Fish that fed on moving prey items had a significantly larger mouth-gape than those that browsed cysts from the tank bottom or dry food items. The development of mouth-gape was not affected by the feeding level of cysts. Condition factor increased with an increase in the number of cysts fed per fish per day. Goldfish larvae and juveniles grew faster and had a higher survival when fed on decapsulated Artemia cysts than on instar I Artemia nauplii or a mixed live/dry diet of Artemia nauplii and dry food. Feeding at least 155 cysts per fish per day, in tanks with upwelling water movement, gave the best growth and survival and the smallest size variation. In addition, cysts remained available to the fish for longer periods, and were easier to prepare and feed. Goldfish larvae preferred decapsulated Artemia cysts to nauplii and rejected fewer prey items as they grew older. The frequency of agonistic behaviour increased as fish grew but no cannibalism was recorded for cyst-fed fish. This study showed that decapsulated Artemia cysts are a good alternative to Artemia nauplii as a diet for larval goldfish. Good growth and high survival was achieved for cyst-fed goldfish larvae and juveniles at 23 ± 1.5°C and at an initial stocking density of 12 fish per litre. This research also contributes to an understanding of feeding behaviour and attempts to minimise under- or over-feeding of Artemia cysts in order to reduce grow-out costs due to the high value of the feed type.
- Full Text:
- Authors: Paulet, Timothy Guy
- Date: 2004
- Subjects: Goldfish -- Growth , Goldfish -- Nutrition , Goldfish -- Development , Goldfish -- Larvae
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5271 , http://hdl.handle.net/10962/d1005115 , Goldfish -- Growth , Goldfish -- Nutrition , Goldfish -- Development , Goldfish -- Larvae
- Description: Intensive grow-out of goldfish, Carassius auratus (L.), larvae and juveniles in closed recirculating systems requires the control of environmental conditions and feeding. This study investigated the effect of different diets, environmental condition and feeding level on growth, development and survival of goldfish larvae and juveniles. Prey preference for Artemia nauplii or decapsulated Artemia cysts as well as agonistic behaviour was recorded. The micrometer device used to measure mouth-gape was shown to produce accurate measurements which could be used to estimate the maximal particle size that can be ingested by goldfish larvae of a particular age. Goldfish completed metamorphosis earlier with an increased feeding level of Artemia cysts and by making the cysts more accessible to the fish using up-welling water movement. Morphometric plasticity in goldfish larvae was exhibited within two weeks of growth and it may be possible to induce changes in morphology by manipulating diet and rearing environment. Fish that fed on moving prey items had a significantly larger mouth-gape than those that browsed cysts from the tank bottom or dry food items. The development of mouth-gape was not affected by the feeding level of cysts. Condition factor increased with an increase in the number of cysts fed per fish per day. Goldfish larvae and juveniles grew faster and had a higher survival when fed on decapsulated Artemia cysts than on instar I Artemia nauplii or a mixed live/dry diet of Artemia nauplii and dry food. Feeding at least 155 cysts per fish per day, in tanks with upwelling water movement, gave the best growth and survival and the smallest size variation. In addition, cysts remained available to the fish for longer periods, and were easier to prepare and feed. Goldfish larvae preferred decapsulated Artemia cysts to nauplii and rejected fewer prey items as they grew older. The frequency of agonistic behaviour increased as fish grew but no cannibalism was recorded for cyst-fed fish. This study showed that decapsulated Artemia cysts are a good alternative to Artemia nauplii as a diet for larval goldfish. Good growth and high survival was achieved for cyst-fed goldfish larvae and juveniles at 23 ± 1.5°C and at an initial stocking density of 12 fish per litre. This research also contributes to an understanding of feeding behaviour and attempts to minimise under- or over-feeding of Artemia cysts in order to reduce grow-out costs due to the high value of the feed type.
- Full Text:
The enzymology of enhanced hydrolysis within the biosulphidogenic recycling sludge bed reactor (RSBR)
- Authors: Enongene, Godlove Nkwelle
- Date: 2004
- Subjects: Hydrolysis , Sewage sludge , Sewage -- Purification -- Anaerobic treatment , Water -- Purification -- Biological treatment
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4132 , http://hdl.handle.net/10962/d1015744
- Description: The hydrolysis of complex organic heteropolymers contained in municipal wastewater to simpler monomers by extracellular hydrolytic enzymes is generally considered the rate-limiting step of the biodegradation process. Previous studies of the Recycling Sludge Bed Reactor (RSBR) revealed that the hydrolysis of complex particulate organics, such as those contained in primary sludge (PS), was enhanced under anaerobic biosulphidogenic conditions. Although the mechanism was not fully understood, it appeared to involve the interaction of sulfide and sludge flocs. The current study was conducted using a 3500 ml laboratory-scale RSBR fed sieved PS at a loading rate of 0.5 kg COD/m³.day and an initial chemical oxygen demand (COD) to sulfate ratio (COD:SO₄) of 1:1. There was no significant accumulation of undigested sludge in the reactor over the 60-day experimental period and the quantity of SO₄ reduced indicated that the yield of soluble products from PS was at least as high as those reported previously for this system (> 50%). In the current study, the specific activities of a range of extracellular hydrolytic enzymes (L-alanine aminopeptidase, L-leucine aminopeptidase, arylsulphatase, α-glucosidase, β- glucosidase, protease and lipase) were monitored in a sulfide gradient within a biosulphidogenic RSBR. Data obtained indicated that the specific enzymatic activities increased with the depth of the RSBR and also correlated with a number of the physicochemical parameters including sulfide, alkalinity and sulfate. The activities of α- glucosidase and β-glucosidase were higher than that of the other enzymes studied. Lipase activity was relatively low and studies conducted on the enzyme-enzyme interaction using specific enzyme inhibitors indicated that lipases were probably being digested by the proteases. Further studies to determine the impact of sulfide on the enzymes, showed an increase in the enzyme activity with increasing sulfide concentration. Possible direct affects were investigated by looking for changes in the Michaelis constant (Km) and the maximal velocity (Vmax) of the crude enzymes with varying sulfide concentrations (250, 400 and 500 mg/l) using natural and synthetic substrates. The results showed no significant difference in both the Km and the Vmax for any of the hydrolytic enzymes except for the protease. The latter showed a statistically significant increase in the Km with increasing sulfide concentration. Although this indicated a direct interaction, this difference was not large enough to be of biochemical significance and was consequently not solely responsible for the enhanced hydrolysis observed in the RSBR. Investigation into the floc characteristics indicated that the biosulphidogenic RSBR flocs were generally small in size and became more dendritic with the depth of the RSBR. Based on the above data, the previously proposed descriptive models of enhanced hydrolysis of particulate organic matter in a biosulphidogenic RSBR has been revised. It is thought that the effect of sulfide on the hydrolysis step is primarily indirect and that the reduction in floc size and alteration of the floc shape to a more dendritic form is central to the success of the process.
- Full Text:
- Authors: Enongene, Godlove Nkwelle
- Date: 2004
- Subjects: Hydrolysis , Sewage sludge , Sewage -- Purification -- Anaerobic treatment , Water -- Purification -- Biological treatment
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4132 , http://hdl.handle.net/10962/d1015744
- Description: The hydrolysis of complex organic heteropolymers contained in municipal wastewater to simpler monomers by extracellular hydrolytic enzymes is generally considered the rate-limiting step of the biodegradation process. Previous studies of the Recycling Sludge Bed Reactor (RSBR) revealed that the hydrolysis of complex particulate organics, such as those contained in primary sludge (PS), was enhanced under anaerobic biosulphidogenic conditions. Although the mechanism was not fully understood, it appeared to involve the interaction of sulfide and sludge flocs. The current study was conducted using a 3500 ml laboratory-scale RSBR fed sieved PS at a loading rate of 0.5 kg COD/m³.day and an initial chemical oxygen demand (COD) to sulfate ratio (COD:SO₄) of 1:1. There was no significant accumulation of undigested sludge in the reactor over the 60-day experimental period and the quantity of SO₄ reduced indicated that the yield of soluble products from PS was at least as high as those reported previously for this system (> 50%). In the current study, the specific activities of a range of extracellular hydrolytic enzymes (L-alanine aminopeptidase, L-leucine aminopeptidase, arylsulphatase, α-glucosidase, β- glucosidase, protease and lipase) were monitored in a sulfide gradient within a biosulphidogenic RSBR. Data obtained indicated that the specific enzymatic activities increased with the depth of the RSBR and also correlated with a number of the physicochemical parameters including sulfide, alkalinity and sulfate. The activities of α- glucosidase and β-glucosidase were higher than that of the other enzymes studied. Lipase activity was relatively low and studies conducted on the enzyme-enzyme interaction using specific enzyme inhibitors indicated that lipases were probably being digested by the proteases. Further studies to determine the impact of sulfide on the enzymes, showed an increase in the enzyme activity with increasing sulfide concentration. Possible direct affects were investigated by looking for changes in the Michaelis constant (Km) and the maximal velocity (Vmax) of the crude enzymes with varying sulfide concentrations (250, 400 and 500 mg/l) using natural and synthetic substrates. The results showed no significant difference in both the Km and the Vmax for any of the hydrolytic enzymes except for the protease. The latter showed a statistically significant increase in the Km with increasing sulfide concentration. Although this indicated a direct interaction, this difference was not large enough to be of biochemical significance and was consequently not solely responsible for the enhanced hydrolysis observed in the RSBR. Investigation into the floc characteristics indicated that the biosulphidogenic RSBR flocs were generally small in size and became more dendritic with the depth of the RSBR. Based on the above data, the previously proposed descriptive models of enhanced hydrolysis of particulate organic matter in a biosulphidogenic RSBR has been revised. It is thought that the effect of sulfide on the hydrolysis step is primarily indirect and that the reduction in floc size and alteration of the floc shape to a more dendritic form is central to the success of the process.
- Full Text:
The enzymology of sludge solubilisation under biosulphidogenic conditions : isolation, characterisation and partial purification of endoglucanases
- Authors: Oyekola, Oluwaseun Oyekanmi
- Date: 2004
- Subjects: Sewage -- Purification -- Anaerobic treatment , Anaerobic bacteria , Sewage sludge , Hydrolysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3921 , http://hdl.handle.net/10962/d1003980 , Sewage -- Purification -- Anaerobic treatment , Anaerobic bacteria , Sewage sludge , Hydrolysis
- Description: Endoglucanases play an important function in cellulose hydrolysis and catalyse the initial attack on the polymer by randomly hydrolysing the β-1,4 glucosidic bonds within the amorphous regions of cellulose chains. Cellulolytic bacteria have been isolated and characterised from the sewage sludge and the activation of several hydrolytic enzymes under biosulphidogenic conditions of sewage hydrolysis has been reported. The aims of this study were to: identify, induce production, locate and isolate, characterise (physicochemical and kinetic) and purify endoglucanases from anaerobic biosulphidogenic sludge. The endoglucanase activities were shown to be associated with the pellet particulate matter and exhibited a pH optimum of 6 and temperature optimum of 50 °C. The enzymes were thermally more stable when immobilised to the floc matrix of the sludge than when they were released into the aqueous solution via sonication. For both immobilised and released enzymes, sulphate was slightly inhibitory; activity was reduced to 84 % and 77.5 % of the initial activity at sulphate concentrations between 200 and 1000 mg/l, respectively. Sulphite was stimulatory to the immobilised enzymes between 200 and 1000 mg/l. Sulphide stimulated the activities of the immobilised endoglucanases, but inhibited activities of the soluble enzymes above 200 mg/l. The enzyme fraction did not hydrolyse avicel (a crystalline substrate), indicating the absence of any exocellulase activity. For CMC (carboxymethylcellulose) and HEC (hydroxylethylcellulose) the enzyme had K_m,app_ values of 4 and 5.1 mg/ml respectively and V_max,app_ values of 0.297 and 0.185 μmol/min/ml respectively. Divalent ions (Cu²⁺, Ni²⁺ and Zn²⁺) proved to be inhibitory while Fe²⁺, Mg²⁺ and Ca²⁺ stimulated the enzyme at concentrations between 200 and 1000 mg/l. All the volatile fatty acids studied (acetic acid, butyric acid, propionic acid and valeric acid) inhibited the enzymes, with acetic acid eliciting the highest degree of inhibition. Sonication released ~74.9 % of the total enzyme activities into solution and this was partially purified by PEG 20 000 concentration followed by DEAE-Cellulose ion exchange chromatography, which resulted in an appreciable purity as measured by the purification factor, 25.4 fold.
- Full Text:
- Authors: Oyekola, Oluwaseun Oyekanmi
- Date: 2004
- Subjects: Sewage -- Purification -- Anaerobic treatment , Anaerobic bacteria , Sewage sludge , Hydrolysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3921 , http://hdl.handle.net/10962/d1003980 , Sewage -- Purification -- Anaerobic treatment , Anaerobic bacteria , Sewage sludge , Hydrolysis
- Description: Endoglucanases play an important function in cellulose hydrolysis and catalyse the initial attack on the polymer by randomly hydrolysing the β-1,4 glucosidic bonds within the amorphous regions of cellulose chains. Cellulolytic bacteria have been isolated and characterised from the sewage sludge and the activation of several hydrolytic enzymes under biosulphidogenic conditions of sewage hydrolysis has been reported. The aims of this study were to: identify, induce production, locate and isolate, characterise (physicochemical and kinetic) and purify endoglucanases from anaerobic biosulphidogenic sludge. The endoglucanase activities were shown to be associated with the pellet particulate matter and exhibited a pH optimum of 6 and temperature optimum of 50 °C. The enzymes were thermally more stable when immobilised to the floc matrix of the sludge than when they were released into the aqueous solution via sonication. For both immobilised and released enzymes, sulphate was slightly inhibitory; activity was reduced to 84 % and 77.5 % of the initial activity at sulphate concentrations between 200 and 1000 mg/l, respectively. Sulphite was stimulatory to the immobilised enzymes between 200 and 1000 mg/l. Sulphide stimulated the activities of the immobilised endoglucanases, but inhibited activities of the soluble enzymes above 200 mg/l. The enzyme fraction did not hydrolyse avicel (a crystalline substrate), indicating the absence of any exocellulase activity. For CMC (carboxymethylcellulose) and HEC (hydroxylethylcellulose) the enzyme had K_m,app_ values of 4 and 5.1 mg/ml respectively and V_max,app_ values of 0.297 and 0.185 μmol/min/ml respectively. Divalent ions (Cu²⁺, Ni²⁺ and Zn²⁺) proved to be inhibitory while Fe²⁺, Mg²⁺ and Ca²⁺ stimulated the enzyme at concentrations between 200 and 1000 mg/l. All the volatile fatty acids studied (acetic acid, butyric acid, propionic acid and valeric acid) inhibited the enzymes, with acetic acid eliciting the highest degree of inhibition. Sonication released ~74.9 % of the total enzyme activities into solution and this was partially purified by PEG 20 000 concentration followed by DEAE-Cellulose ion exchange chromatography, which resulted in an appreciable purity as measured by the purification factor, 25.4 fold.
- Full Text:
The experiences and needs of HIV/AIDS counsellors at Settlers Hospital, Grahamstown
- Authors: Nulty, Maria
- Date: 2004
- Subjects: AIDS (Disease) -- Patients -- Counseling of -- South Africa -- Eastern Cape HIV-positive persons -- Counseling of -- South Africa -- Eastern Cape Counselors -- South Africa -- Eastern Cape Counselors -- Supervision of -- South Africa -- Eastern Cape Counselors -- Training of -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3032 , http://hdl.handle.net/10962/d1002541
- Description: Cognisant of the fact that counselling has become an essential aspect of dealing with HIV/AIDS in South Africa, the researcher aimed to explore the stressors experienced by HIV/AIDS counsellors. It was envisioned that the results obtained would both help to improve the counselling services provided at Settlers Hospital, and assist other organisations to do so. The research focused on how the participants dealt with the dual roles of non-directive listening and the more prescriptive advice-giving, the stressors they experienced and the support structures they had, or needed, to assist them in being more effective HIV/AIDS counsellors. The sample consisted of four HIV/AIDS counsellors working at Settlers Hospital, Grahamstown. The co-ordinator of HIV/AIDS at the hospital was interviewed for collateral information. A qualitative, multiple case study was undertaken. In-depth, semi-structured interviews were used to collect the data which were recorded and transcribed and then constructed into coherently organised personal narratives of each participant’s experiences. A composite description of all the results was arrived at through the use of a reading guide which reduced the data into a thematic content analysis. The analysed data served to present an understanding of the counsellors’ experiences and to enable recommendations to be made which could assist them in pursuing their work more effectively. The findings of this study indicate that HIV/AIDS counselling is an emotionally stressful occupation. Contributory factors include the twofold role of promoting prevention and serving as empathic listeners. Other stressors derive from issues of confidentiality and stigma concerning HIV/AIDS, counsellors’ identification with clients’ experiences and the demographics of HIV/AIDS in South Africa. Situational stressors which arise from working as both nurses and counsellors in a public health institution were also identified. Recommendations are made to alleviate the counsellors’ stress in the form of facilitated emotional support groups, professional supervision, managerial support to improve the working environment, and ongoing in-service training.
- Full Text:
- Authors: Nulty, Maria
- Date: 2004
- Subjects: AIDS (Disease) -- Patients -- Counseling of -- South Africa -- Eastern Cape HIV-positive persons -- Counseling of -- South Africa -- Eastern Cape Counselors -- South Africa -- Eastern Cape Counselors -- Supervision of -- South Africa -- Eastern Cape Counselors -- Training of -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3032 , http://hdl.handle.net/10962/d1002541
- Description: Cognisant of the fact that counselling has become an essential aspect of dealing with HIV/AIDS in South Africa, the researcher aimed to explore the stressors experienced by HIV/AIDS counsellors. It was envisioned that the results obtained would both help to improve the counselling services provided at Settlers Hospital, and assist other organisations to do so. The research focused on how the participants dealt with the dual roles of non-directive listening and the more prescriptive advice-giving, the stressors they experienced and the support structures they had, or needed, to assist them in being more effective HIV/AIDS counsellors. The sample consisted of four HIV/AIDS counsellors working at Settlers Hospital, Grahamstown. The co-ordinator of HIV/AIDS at the hospital was interviewed for collateral information. A qualitative, multiple case study was undertaken. In-depth, semi-structured interviews were used to collect the data which were recorded and transcribed and then constructed into coherently organised personal narratives of each participant’s experiences. A composite description of all the results was arrived at through the use of a reading guide which reduced the data into a thematic content analysis. The analysed data served to present an understanding of the counsellors’ experiences and to enable recommendations to be made which could assist them in pursuing their work more effectively. The findings of this study indicate that HIV/AIDS counselling is an emotionally stressful occupation. Contributory factors include the twofold role of promoting prevention and serving as empathic listeners. Other stressors derive from issues of confidentiality and stigma concerning HIV/AIDS, counsellors’ identification with clients’ experiences and the demographics of HIV/AIDS in South Africa. Situational stressors which arise from working as both nurses and counsellors in a public health institution were also identified. Recommendations are made to alleviate the counsellors’ stress in the form of facilitated emotional support groups, professional supervision, managerial support to improve the working environment, and ongoing in-service training.
- Full Text:
The feeding biology and potential impact of introduced giraffe (Giraffa camelopardalis) in the Eastern Cape Province, South Africa
- Authors: Parker, Daniel Matthew
- Date: 2004
- Subjects: Giraffe -- South Africa -- Eastern Cape , Animal-plant relationships -- South Africa -- Eastern Cape , Giraffe -- Food -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5694 , http://hdl.handle.net/10962/d1005380
- Description: Giraffe (Giraffa camelopardalis) are extralimital (non-native) to the Eastern Cape Province, South Africa yet they have and continue to be introduced to the region. Financial gain has arguably been the driving force behind these introductions as foreign tourists associate giraffe with Africa and the African wildlife experience. This raises a number of ethical, ecological and philosophical questions especially when it is considered that the impact of these browsers on the indigenous vegetation has remained largely unquantified. In this study I assessed the diet and potential impact of three populations of giraffe in the Eastern Cape Province between January 2002 and October 2003. The diet was assessed by both direct observations and faecal analysis. There was no significant difference (P > 0.05) between the results of the two methods of analysis, although direct observations appeared to be a superior method for assessing the diet of giraffe. The diet of giraffe in the Eastern Cape Province was similar to that within their native range with a deciduous species from the genus Acacia (Acacia karroo) being the most important component of the diet. However, giraffe in the Eastern Cape Province consumed more evergreen plant species than those within their native range. The relative lack of deciduous species in the Eastern Cape Province provides a likely explanation for such a result. Seasonal variation in the consumption of the most important species in the diet was evident and this was attributed to the deciduous nature of A. karroo and the seasonal growth of new shoots which were more palatable. The vegetation of the areas most commonly utilised by giraffe at each site was sampled using the point-centred-quarter method and the results related to the frequency of each species in the diet to calculate preference indices. Giraffe preference was strongest for A. karroo and this was attributed to the highly favourable chemical composition of the species. The browse utilisation of giraffe at each site was determined using the twig-length method and intake rates for the three most important species in the diet calculated using a pre-existing regression equation. Male giraffe fed at a higher rate than females. This was probably due to males adopting a “time-minimising” strategy to their feeding in order to allow more time for reproductive pursuits. Giraffe browse utilisation was highest where giraffe density was highest. However, several species were more heavily browsed than others even when giraffe density was low, suggesting that giraffe are capable of negatively affecting the indigenous flora of the province. I conclude that giraffe numbers should be reduced relative to property size in the Eastern Cape Province and that research into the impact of not only giraffe but the combined effects of giraffe and other extralimital herbivores on the indigenous flora and fauna be continued.
- Full Text:
- Authors: Parker, Daniel Matthew
- Date: 2004
- Subjects: Giraffe -- South Africa -- Eastern Cape , Animal-plant relationships -- South Africa -- Eastern Cape , Giraffe -- Food -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5694 , http://hdl.handle.net/10962/d1005380
- Description: Giraffe (Giraffa camelopardalis) are extralimital (non-native) to the Eastern Cape Province, South Africa yet they have and continue to be introduced to the region. Financial gain has arguably been the driving force behind these introductions as foreign tourists associate giraffe with Africa and the African wildlife experience. This raises a number of ethical, ecological and philosophical questions especially when it is considered that the impact of these browsers on the indigenous vegetation has remained largely unquantified. In this study I assessed the diet and potential impact of three populations of giraffe in the Eastern Cape Province between January 2002 and October 2003. The diet was assessed by both direct observations and faecal analysis. There was no significant difference (P > 0.05) between the results of the two methods of analysis, although direct observations appeared to be a superior method for assessing the diet of giraffe. The diet of giraffe in the Eastern Cape Province was similar to that within their native range with a deciduous species from the genus Acacia (Acacia karroo) being the most important component of the diet. However, giraffe in the Eastern Cape Province consumed more evergreen plant species than those within their native range. The relative lack of deciduous species in the Eastern Cape Province provides a likely explanation for such a result. Seasonal variation in the consumption of the most important species in the diet was evident and this was attributed to the deciduous nature of A. karroo and the seasonal growth of new shoots which were more palatable. The vegetation of the areas most commonly utilised by giraffe at each site was sampled using the point-centred-quarter method and the results related to the frequency of each species in the diet to calculate preference indices. Giraffe preference was strongest for A. karroo and this was attributed to the highly favourable chemical composition of the species. The browse utilisation of giraffe at each site was determined using the twig-length method and intake rates for the three most important species in the diet calculated using a pre-existing regression equation. Male giraffe fed at a higher rate than females. This was probably due to males adopting a “time-minimising” strategy to their feeding in order to allow more time for reproductive pursuits. Giraffe browse utilisation was highest where giraffe density was highest. However, several species were more heavily browsed than others even when giraffe density was low, suggesting that giraffe are capable of negatively affecting the indigenous flora of the province. I conclude that giraffe numbers should be reduced relative to property size in the Eastern Cape Province and that research into the impact of not only giraffe but the combined effects of giraffe and other extralimital herbivores on the indigenous flora and fauna be continued.
- Full Text:
The fuelwood crisis in southern Africa: Relating fuelwood use to livelihoods in a rural village
- Dovie, Delali B K, Witkowski, Ed T F, Shackleton, Charlie M
- Authors: Dovie, Delali B K , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181402 , vital:43730 , xlink:href="https://doi.org/10.1023/B:GEJO.0000033597.34013.9f"
- Description: The aim of the paper is to examine wood as a source of fuel energy in rural South Africa and factors influencing its usage. The analysis is based on household profiles and characteristics (e.g., gender, caste, population and income) in a livelihood framework. Fuelwood consumption was estimated to be 692 kg/capita, and 4343 kg/user household per annum, valued at $311 per household. Consumption was modelled in relation to informal and formal cash incomes, and population of children, female and male adults. However, only the population of female adults could significantly influence consumption of fuelwood. This implied that where there were more women in a household, consumption was likely to be high. This might be due to the majority of women doing the cooking and heating in the household. Any change in the value of cash income of households had no significant impacts on fuelwood consumed. Cash incomes might therefore not be strong determinants of the types of energy used by rural households. The average quantity of wood consumed for fuel energy in summer was not significantly different from consumption in winter. Some households perpetually used more wood than others. The study further showed that harvesting of wood for fuel energy is not opportunistic, but requires reallocation of time for other livelihood activities in times of shortage. The fuelwood crisis is not simple and not only about shortage of fuelwood and/or population growth but linked to household profiles and other livelihood strategies and subsequently vulnerability of households. These would require thorough investigation and understanding in relation to precise demand and supply data for fuelwood before the fuelwood problem can be sufficiently managed.
- Full Text:
- Authors: Dovie, Delali B K , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181402 , vital:43730 , xlink:href="https://doi.org/10.1023/B:GEJO.0000033597.34013.9f"
- Description: The aim of the paper is to examine wood as a source of fuel energy in rural South Africa and factors influencing its usage. The analysis is based on household profiles and characteristics (e.g., gender, caste, population and income) in a livelihood framework. Fuelwood consumption was estimated to be 692 kg/capita, and 4343 kg/user household per annum, valued at $311 per household. Consumption was modelled in relation to informal and formal cash incomes, and population of children, female and male adults. However, only the population of female adults could significantly influence consumption of fuelwood. This implied that where there were more women in a household, consumption was likely to be high. This might be due to the majority of women doing the cooking and heating in the household. Any change in the value of cash income of households had no significant impacts on fuelwood consumed. Cash incomes might therefore not be strong determinants of the types of energy used by rural households. The average quantity of wood consumed for fuel energy in summer was not significantly different from consumption in winter. Some households perpetually used more wood than others. The study further showed that harvesting of wood for fuel energy is not opportunistic, but requires reallocation of time for other livelihood activities in times of shortage. The fuelwood crisis is not simple and not only about shortage of fuelwood and/or population growth but linked to household profiles and other livelihood strategies and subsequently vulnerability of households. These would require thorough investigation and understanding in relation to precise demand and supply data for fuelwood before the fuelwood problem can be sufficiently managed.
- Full Text:
The general election in Lesotho, May 2002: adapting to MMP
- Fox, Roddy C, Southall, Roger J
- Authors: Fox, Roddy C , Southall, Roger J
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6680 , http://hdl.handle.net/10962/d1006673
- Description: Voters in the small southern African kingdom of Lesotho went to the polls on 25 May 2002, in the third general election since the country returned to democracy following a long period of civilian dictatorship (1970–1986) and military rule (1986–1993). Voting in all Lesotho’s general elections has usually gone smoothly, yet in every case prior to 2002 the results have been challenged, with varying severity, by the losing parties (Weisfelder, 1999). This occurred most notably in 1970, when the ruling Basotho National Party (BNP) lost the election but overrode the result, and subsequently in 1998, when the BNP—then in opposition—was at the core of an alliance of electoral losers; in the months that followed, and with the quiet support of the security forces, the capital was so paralysed that the government called for external assistance to restore order. The result was military intervention by South Africa and Botswana (who acted on behalf of the Southern African Development Community, SADC), the restoration of power to the Lesotho Congress for Democracy (LCD), and an extended period when, backed by South African muscle, long overdue reforms of the military and police were implemented. These reforms were matched by negotiations between the parties about adopting a new electoral system. The outcome moved Lesotho away from the first-past-the-post system inherited from Britain at independence (which in 1993 and 1998 had resulted in highly imbalanced results favouring the winning party) towards a Mixed Member Proportional (MMP) system. Lesotho became the first country in Africa to adopt MMP at a time when discussion of electoral system change was becoming widespread throughout the continent. The issue in Lesotho in 2002 was not merely whether MMP would provide greater electoral legitimacy and political stability; subsequent events have provided a resounding ‘Yes’ (Elklit, 2002 and Southall, 2003). But there were questions about the practicality of the new system and whether voters would understand it. Was it possible to explain a new voting system to an electorate in one of Africa’s poorest countries? The main focus of this Note is to demonstrate that voters can adapt to electoral system change. Thus, it throws doubt on arguments that electoral reforms in Africa should be avoided due to a lack of sophistication among poor and largely uneducated voters. Electors in Lesotho appeared to have no great difficulty in understanding the broad principles of the new electoral system, even if the detailed mechanics of ‘mixed’ voting systems may have been beyond them.
- Full Text:
- Authors: Fox, Roddy C , Southall, Roger J
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6680 , http://hdl.handle.net/10962/d1006673
- Description: Voters in the small southern African kingdom of Lesotho went to the polls on 25 May 2002, in the third general election since the country returned to democracy following a long period of civilian dictatorship (1970–1986) and military rule (1986–1993). Voting in all Lesotho’s general elections has usually gone smoothly, yet in every case prior to 2002 the results have been challenged, with varying severity, by the losing parties (Weisfelder, 1999). This occurred most notably in 1970, when the ruling Basotho National Party (BNP) lost the election but overrode the result, and subsequently in 1998, when the BNP—then in opposition—was at the core of an alliance of electoral losers; in the months that followed, and with the quiet support of the security forces, the capital was so paralysed that the government called for external assistance to restore order. The result was military intervention by South Africa and Botswana (who acted on behalf of the Southern African Development Community, SADC), the restoration of power to the Lesotho Congress for Democracy (LCD), and an extended period when, backed by South African muscle, long overdue reforms of the military and police were implemented. These reforms were matched by negotiations between the parties about adopting a new electoral system. The outcome moved Lesotho away from the first-past-the-post system inherited from Britain at independence (which in 1993 and 1998 had resulted in highly imbalanced results favouring the winning party) towards a Mixed Member Proportional (MMP) system. Lesotho became the first country in Africa to adopt MMP at a time when discussion of electoral system change was becoming widespread throughout the continent. The issue in Lesotho in 2002 was not merely whether MMP would provide greater electoral legitimacy and political stability; subsequent events have provided a resounding ‘Yes’ (Elklit, 2002 and Southall, 2003). But there were questions about the practicality of the new system and whether voters would understand it. Was it possible to explain a new voting system to an electorate in one of Africa’s poorest countries? The main focus of this Note is to demonstrate that voters can adapt to electoral system change. Thus, it throws doubt on arguments that electoral reforms in Africa should be avoided due to a lack of sophistication among poor and largely uneducated voters. Electors in Lesotho appeared to have no great difficulty in understanding the broad principles of the new electoral system, even if the detailed mechanics of ‘mixed’ voting systems may have been beyond them.
- Full Text:
The geology of the Proterozoic Haveri Au-Cu deposit, Southern Finland
- Strauss, Toby Anthony Lavery
- Authors: Strauss, Toby Anthony Lavery
- Date: 2004
- Subjects: Geology, Stratigraphic -- Precambrian , Geology, Stratigraphic -- Proterozoic , Ore deposits -- Finland , Geology -- Finland
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5081 , http://hdl.handle.net/10962/d1015978
- Description: The Haveri Au-Cu deposit is located in southern Finland about 175 km north of Helsinki. It occurs on the northern edge of the continental island arc-type, volcano-sedimentary Tampere Schist Belt (TSB) within the Palaeoproterozoic Svecofennian Domain (2.0 – 1.75 Ga) of the Fennoscandian Shield. The 1.99 Ga Haveri Formation forms the base of the supracrustal stratigraphy consisting of metavolcanic pillow lavas and breccias passing upwards into intercalated metatuffs and metatuffites. There is a continuous gradation upwards from the predominantly volcaniclastic Haveri Formation into the overlying epiclastic meta-greywackes of the Osara Formation. The Haveri deposit is hosted in this contact zone. This supracrustal sequence has been intruded concordantly by quartz-feldspar porphyries. Approximately 1.89 Ga ago, high crustal heat flow led to the generation and emplacement of voluminous synkinematic, I-type, magnetite-series granitoids of the Central Finland Granitoid Complex (CFGC), resulting in coeval high-T/low-P metamorphism (hornfelsic textures), and D₁ deformation. During the crystallisation and cooling of the granitoids, a magmatic-dominated hydrothermal system caused extensive hydrothermal alteration and Cu-Au mineralisation through the late-D₁ to early-D₂ deformation. Initially, a pre-ore Na-Ca alteration phase caused albitisation of the host rock. This was closely followed by strong Ca-Fe alteration, responsible for widespread amphibolitisation and quartz veining and associated with abundant pyrrhotite, magnetite, chalcopyrite and gold mineralisation. More localised calcic-skarn alteration is also present as zoned garnetpyroxene- epidote skarn assemblages with associated pyrrhotite and minor sphalerite, centred on quartzcalcite± scapolite veinlets. Post-ore alteration includes an evolution to more K-rich alteration (biotitisation). Late D₂-retrograde chlorite began to replace the earlier high-T assemblage. Late emanations (post-D₂ and pre-D₃) from the cooling granitoids, under lower temperatures and oxidising conditions, are represented by carbonate-barite veins and epidote veinlets. Later, narrow dolerite dykes were emplaced followed by a weak D₃ deformation, resulting in shearing and structural reactivation along the carbonate-barite bands. This phase was accompanied by pyrite deposition. Both sulphides and oxides are common at Haveri, with ore types varying from massive sulphide and/or magnetite, to networks of veinlets and disseminations of oxides and/or sulphides. Cataclastites, consisting of deformed, brecciated bands of sulphide, with rounded and angular clasts of quartz vein material and altered host-rock are an economically important ore type. Ore minerals are principally pyrrhotite, magnetite and chalcopyrite with lesser amounts of pyrite, molybdenite and sphalerite. There is a general progression from early magnetite, through pyrrhotite to pyrite indicating increasing sulphidation with time. Gold is typically found as free gold within quartz veins and within intense zones of amphibolitisation. Considerable gold is also found in the cataclastite ore type either as invisible gold within the sulphides and/or as free gold within the breccia fragments. The unaltered amphibolites of the Haveri Formation can be classified as medium-K basalts of the tholeiitic trend. Trace and REE support an interpretation of formation in a back-arc basin setting. The unaltered porphyritic rocks are calc-alkaline dacites, and are interpreted, along with the granitoids as having an arc-type origin. This is consistent with the evolution from an initial back-arc basin, through a period of passive margin and/or fore-arc deposition represented by the Osara Formation greywackes and the basal stratigraphy of the TSB, prior to the onset of arc-related volcanic activity characteristic of the TSB and the Svecofennian proper. Using a combination of petrogenetic grids, mineral compositions (garnet-biotite and hornblendeplagioclase thermometers) and oxygen isotope thermometry, peak metamorphism can be constrained to a maximum of approximately 600 °C and 1.5 kbars pressure. Furthermore, the petrogenetic grids indicate that the REDOX conditions can be constrained at 600°C to log f(O₂) values of approximately - 21.0 to -26.0 and -14.5 to -17.5 for the metasedimentary rocks and mafic metavolcanic rocks respectively, thus indicating the presence of a significant REDOX boundary. Amphibole compositions from the Ca-Fe alteration phase (amphibolitisation) indicate iron enrichment with increasing alteration corresponding to higher temperatures of formation. Oxygen isotope studies combined with limited fluid inclusion studies indicate that the Ca-Fe alteration and associated quartz veins formed at high temperatures (530 – 610°C) from low CO₂, low- to moderately saline (<10 eq. wt% NaCl), magmatic-dominated fluids. Fluid inclusion decrepitation textures in the quartz veins suggest isobaric decompression. This is compatible with formation in high-T/low-P environments such as contact aureoles and island arcs. The calcic-skarn assemblage, combined with phase equilibria and sphalerite geothermometry, are indicative of formation at high temperatures (500 – 600 °C) from fluids with higher CO₂ contents and more saline compositions than those responsible for the Fe-Ca alteration. Limited fluid inclusion studies have identified hypersaline inclusions in secondary inclusion trails within quartz. The presence of calcite and scapolite also support formation from CO₂-rich saline fluids. It is suggested that the calcic-skarn alteration and the amphibolitisation evolved from the same fluids, and that P-T changes led to fluid unmixing resulting in two fluid types responsible for the observed alteration variations. Chlorite geothermometry on retrograde chlorite indicates temperatures of 309 – 368 °C. As chlorite represents the latest hydrothermal event, this can be taken as a lower temperature limit for hydrothermal alteration and mineralisation at Haveri.The gold mineralisation at Haveri is related primarily to the Ca-Fe alteration. Under such P-T-X conditions gold was transported as chloride complexes. Ore was localised by a combination of structural controls (shears and folds) and REDOX reactions along the boundary between the oxidised metavolcanics and the reduced metasediments. In addition, fluid unmixing caused an increase in pH, and thus further augmented the precipitation of Cu and Au. During the late D₂-event, temperatures fell below 400 °C, and fluids may have remobilised Au and Cu as bisulphide complexes into the shearcontrolled cataclastites and massive sulphides. The Haveri deposit has many similarities with ore deposit models that include orogenic lode-gold deposits, certain Au-skarn deposits and Fe-oxide Cu-Au deposits. However, many characteristics of the Haveri deposit, including tectonic setting, host lithologies, alteration types, proximity to I-type granitoids and P-T-X conditions of formation, compare favourably with other Early Proterozoic deposits within the TSB and Fennoscandia, as well as many of the deposits in the Cloncurry district of Australia. Consequently, the Haveri deposit can be seen to represent a high-T, Ca-rich member of the recently recognised Fe-oxide Cu-Au group of deposits.
- Full Text:
- Authors: Strauss, Toby Anthony Lavery
- Date: 2004
- Subjects: Geology, Stratigraphic -- Precambrian , Geology, Stratigraphic -- Proterozoic , Ore deposits -- Finland , Geology -- Finland
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5081 , http://hdl.handle.net/10962/d1015978
- Description: The Haveri Au-Cu deposit is located in southern Finland about 175 km north of Helsinki. It occurs on the northern edge of the continental island arc-type, volcano-sedimentary Tampere Schist Belt (TSB) within the Palaeoproterozoic Svecofennian Domain (2.0 – 1.75 Ga) of the Fennoscandian Shield. The 1.99 Ga Haveri Formation forms the base of the supracrustal stratigraphy consisting of metavolcanic pillow lavas and breccias passing upwards into intercalated metatuffs and metatuffites. There is a continuous gradation upwards from the predominantly volcaniclastic Haveri Formation into the overlying epiclastic meta-greywackes of the Osara Formation. The Haveri deposit is hosted in this contact zone. This supracrustal sequence has been intruded concordantly by quartz-feldspar porphyries. Approximately 1.89 Ga ago, high crustal heat flow led to the generation and emplacement of voluminous synkinematic, I-type, magnetite-series granitoids of the Central Finland Granitoid Complex (CFGC), resulting in coeval high-T/low-P metamorphism (hornfelsic textures), and D₁ deformation. During the crystallisation and cooling of the granitoids, a magmatic-dominated hydrothermal system caused extensive hydrothermal alteration and Cu-Au mineralisation through the late-D₁ to early-D₂ deformation. Initially, a pre-ore Na-Ca alteration phase caused albitisation of the host rock. This was closely followed by strong Ca-Fe alteration, responsible for widespread amphibolitisation and quartz veining and associated with abundant pyrrhotite, magnetite, chalcopyrite and gold mineralisation. More localised calcic-skarn alteration is also present as zoned garnetpyroxene- epidote skarn assemblages with associated pyrrhotite and minor sphalerite, centred on quartzcalcite± scapolite veinlets. Post-ore alteration includes an evolution to more K-rich alteration (biotitisation). Late D₂-retrograde chlorite began to replace the earlier high-T assemblage. Late emanations (post-D₂ and pre-D₃) from the cooling granitoids, under lower temperatures and oxidising conditions, are represented by carbonate-barite veins and epidote veinlets. Later, narrow dolerite dykes were emplaced followed by a weak D₃ deformation, resulting in shearing and structural reactivation along the carbonate-barite bands. This phase was accompanied by pyrite deposition. Both sulphides and oxides are common at Haveri, with ore types varying from massive sulphide and/or magnetite, to networks of veinlets and disseminations of oxides and/or sulphides. Cataclastites, consisting of deformed, brecciated bands of sulphide, with rounded and angular clasts of quartz vein material and altered host-rock are an economically important ore type. Ore minerals are principally pyrrhotite, magnetite and chalcopyrite with lesser amounts of pyrite, molybdenite and sphalerite. There is a general progression from early magnetite, through pyrrhotite to pyrite indicating increasing sulphidation with time. Gold is typically found as free gold within quartz veins and within intense zones of amphibolitisation. Considerable gold is also found in the cataclastite ore type either as invisible gold within the sulphides and/or as free gold within the breccia fragments. The unaltered amphibolites of the Haveri Formation can be classified as medium-K basalts of the tholeiitic trend. Trace and REE support an interpretation of formation in a back-arc basin setting. The unaltered porphyritic rocks are calc-alkaline dacites, and are interpreted, along with the granitoids as having an arc-type origin. This is consistent with the evolution from an initial back-arc basin, through a period of passive margin and/or fore-arc deposition represented by the Osara Formation greywackes and the basal stratigraphy of the TSB, prior to the onset of arc-related volcanic activity characteristic of the TSB and the Svecofennian proper. Using a combination of petrogenetic grids, mineral compositions (garnet-biotite and hornblendeplagioclase thermometers) and oxygen isotope thermometry, peak metamorphism can be constrained to a maximum of approximately 600 °C and 1.5 kbars pressure. Furthermore, the petrogenetic grids indicate that the REDOX conditions can be constrained at 600°C to log f(O₂) values of approximately - 21.0 to -26.0 and -14.5 to -17.5 for the metasedimentary rocks and mafic metavolcanic rocks respectively, thus indicating the presence of a significant REDOX boundary. Amphibole compositions from the Ca-Fe alteration phase (amphibolitisation) indicate iron enrichment with increasing alteration corresponding to higher temperatures of formation. Oxygen isotope studies combined with limited fluid inclusion studies indicate that the Ca-Fe alteration and associated quartz veins formed at high temperatures (530 – 610°C) from low CO₂, low- to moderately saline (<10 eq. wt% NaCl), magmatic-dominated fluids. Fluid inclusion decrepitation textures in the quartz veins suggest isobaric decompression. This is compatible with formation in high-T/low-P environments such as contact aureoles and island arcs. The calcic-skarn assemblage, combined with phase equilibria and sphalerite geothermometry, are indicative of formation at high temperatures (500 – 600 °C) from fluids with higher CO₂ contents and more saline compositions than those responsible for the Fe-Ca alteration. Limited fluid inclusion studies have identified hypersaline inclusions in secondary inclusion trails within quartz. The presence of calcite and scapolite also support formation from CO₂-rich saline fluids. It is suggested that the calcic-skarn alteration and the amphibolitisation evolved from the same fluids, and that P-T changes led to fluid unmixing resulting in two fluid types responsible for the observed alteration variations. Chlorite geothermometry on retrograde chlorite indicates temperatures of 309 – 368 °C. As chlorite represents the latest hydrothermal event, this can be taken as a lower temperature limit for hydrothermal alteration and mineralisation at Haveri.The gold mineralisation at Haveri is related primarily to the Ca-Fe alteration. Under such P-T-X conditions gold was transported as chloride complexes. Ore was localised by a combination of structural controls (shears and folds) and REDOX reactions along the boundary between the oxidised metavolcanics and the reduced metasediments. In addition, fluid unmixing caused an increase in pH, and thus further augmented the precipitation of Cu and Au. During the late D₂-event, temperatures fell below 400 °C, and fluids may have remobilised Au and Cu as bisulphide complexes into the shearcontrolled cataclastites and massive sulphides. The Haveri deposit has many similarities with ore deposit models that include orogenic lode-gold deposits, certain Au-skarn deposits and Fe-oxide Cu-Au deposits. However, many characteristics of the Haveri deposit, including tectonic setting, host lithologies, alteration types, proximity to I-type granitoids and P-T-X conditions of formation, compare favourably with other Early Proterozoic deposits within the TSB and Fennoscandia, as well as many of the deposits in the Cloncurry district of Australia. Consequently, the Haveri deposit can be seen to represent a high-T, Ca-rich member of the recently recognised Fe-oxide Cu-Au group of deposits.
- Full Text:
The Harry Potter phenomenon literary production, generic traditions, and the question of values
- Authors: Glover, Jayne Ashleigh
- Date: 2004
- Subjects: Rowling, J. K. Criticism and interpretation , Potter, Harry (Fictitious character) , Children's literature -- History and criticism , Fantasy fiction, English -- History and criticism , Wizards in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2201 , http://hdl.handle.net/10962/d1002243 , Rowling, J. K. Criticism and interpretation , Potter, Harry (Fictitious character) , Children's literature -- History and criticism , Fantasy fiction, English -- History and criticism , Wizards in literature
- Description: This thesis is a study of the first four books of J. K. Rowling’s Harry Potter series. It accounts for the widespread success of the novels by examining their publication and marketing histories, and their literary achievement as narratives including a sophisticated mix of generic traditions. Chapter One looks at the popularity of the novels, comparing their material production and marketing by Rowling’s English language publishers: Bloomsbury in Britain and Scholastic in the United States of America. The publisher’s influence on the public perception of each book is demonstrated by comparative study of its mode of illustration and layout. Further, the design of the books is linked to their strategic marketing and branding within the literary world. The second chapter considers Rowling’s debt to the school story. It concentrates first on the history of this relatively short-lived genre, briefly discussing its stereotypical features and values. Traditional elements of setting and characterisation are then examined to show how the Harry Potter novels present a value system which, though apparently old-fashioned, still has an ethical standpoint designed to appeal to the modern reader. Chapter Three focuses on the characterisation of Harry as a hero-figure, especially on how the influence of classical and medieval texts infuses Rowling’s portrayal of Harry as a hero in the chivalric mode. The episodes of “quest” and “test” in each book illustrate specifically how he learns the values of selflessness, loyalty, mercy and fairness. Chapter Four surveys the contribution of modern fantasy writing to the series. It shows how Rowling creates a secondary world that allows us to perceive magic as a metaphorical representation of power. This focus on the relationship between magic and power in turn has a bearing on our assessment of the author’s moral stance. The thesis concludes by suggesting that Rowling’s unusual mix of genres is justified by the values they share, and which are inscribed in her work: the generic combination forms a workable, new and exciting mode of writing that helps to account for the phenomenal popularity of the series.
- Full Text:
- Authors: Glover, Jayne Ashleigh
- Date: 2004
- Subjects: Rowling, J. K. Criticism and interpretation , Potter, Harry (Fictitious character) , Children's literature -- History and criticism , Fantasy fiction, English -- History and criticism , Wizards in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2201 , http://hdl.handle.net/10962/d1002243 , Rowling, J. K. Criticism and interpretation , Potter, Harry (Fictitious character) , Children's literature -- History and criticism , Fantasy fiction, English -- History and criticism , Wizards in literature
- Description: This thesis is a study of the first four books of J. K. Rowling’s Harry Potter series. It accounts for the widespread success of the novels by examining their publication and marketing histories, and their literary achievement as narratives including a sophisticated mix of generic traditions. Chapter One looks at the popularity of the novels, comparing their material production and marketing by Rowling’s English language publishers: Bloomsbury in Britain and Scholastic in the United States of America. The publisher’s influence on the public perception of each book is demonstrated by comparative study of its mode of illustration and layout. Further, the design of the books is linked to their strategic marketing and branding within the literary world. The second chapter considers Rowling’s debt to the school story. It concentrates first on the history of this relatively short-lived genre, briefly discussing its stereotypical features and values. Traditional elements of setting and characterisation are then examined to show how the Harry Potter novels present a value system which, though apparently old-fashioned, still has an ethical standpoint designed to appeal to the modern reader. Chapter Three focuses on the characterisation of Harry as a hero-figure, especially on how the influence of classical and medieval texts infuses Rowling’s portrayal of Harry as a hero in the chivalric mode. The episodes of “quest” and “test” in each book illustrate specifically how he learns the values of selflessness, loyalty, mercy and fairness. Chapter Four surveys the contribution of modern fantasy writing to the series. It shows how Rowling creates a secondary world that allows us to perceive magic as a metaphorical representation of power. This focus on the relationship between magic and power in turn has a bearing on our assessment of the author’s moral stance. The thesis concludes by suggesting that Rowling’s unusual mix of genres is justified by the values they share, and which are inscribed in her work: the generic combination forms a workable, new and exciting mode of writing that helps to account for the phenomenal popularity of the series.
- Full Text:
The impact of commercial harvesting on Warburgia salutaris (‘pepper-bark tree’) in Mpumalanga, South Africa
- Botha, Jenny, Witkowski, Ed T F, Shackleton, Charlie M
- Authors: Botha, Jenny , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181391 , vital:43729 , xlink:href="https://doi.org/10.1023/B:BIOC.0000029333.72945.b0"
- Description: Commercialisation often increases the difficulty in managing harvested plant populations sustainably. The bark of the popular medicinal species, Warburgia salutaris (Bertol.f.) Chiov. (Canellaceae) (‘pepper-bark tree’), is widely traded throughout southern Africa. The impact of commercial harvesting on this Red Data species was assessed by comparing commercially harvested populations with populations growing on private land or in protected areas (termed ‘protected populations’) in Mpumalanga and Limpopo Province, South Africa. The basal diameters and heights of stems in commercially harvested populations were significantly lower than those of the protected populations. The density of young/small plants was low in all populations. W. salutaris is usually resilient to high levels of bark harvesting. In this study, 75% of heavily harvested stems (>10% of the stem below 2 m) coppiced (resprouted). However, individuals that had been affected by regular fires, or repeatedly harvested, appeared prone to a fungal disease and had high percentage mortality. The populations occurring on private land appeared the most vigorous. Habitat in one protected area had been reduced through the construction of a dam. In another, small W. salutaris populations exhibited a shrubby growth form, probably due to frequent fires. Our current knowledge for this species supports a global IUCN status of EN A4acd. Plant conservation needs to become a higher priority both within and outside protected areas. Commercially harvested populations should be better managed through improved harvesting techniques and monitoring. Cultivation levels urgently need to be increased. Further research should be conducted on factors limiting regeneration, including the most appropriate fire regime.
- Full Text:
- Authors: Botha, Jenny , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181391 , vital:43729 , xlink:href="https://doi.org/10.1023/B:BIOC.0000029333.72945.b0"
- Description: Commercialisation often increases the difficulty in managing harvested plant populations sustainably. The bark of the popular medicinal species, Warburgia salutaris (Bertol.f.) Chiov. (Canellaceae) (‘pepper-bark tree’), is widely traded throughout southern Africa. The impact of commercial harvesting on this Red Data species was assessed by comparing commercially harvested populations with populations growing on private land or in protected areas (termed ‘protected populations’) in Mpumalanga and Limpopo Province, South Africa. The basal diameters and heights of stems in commercially harvested populations were significantly lower than those of the protected populations. The density of young/small plants was low in all populations. W. salutaris is usually resilient to high levels of bark harvesting. In this study, 75% of heavily harvested stems (>10% of the stem below 2 m) coppiced (resprouted). However, individuals that had been affected by regular fires, or repeatedly harvested, appeared prone to a fungal disease and had high percentage mortality. The populations occurring on private land appeared the most vigorous. Habitat in one protected area had been reduced through the construction of a dam. In another, small W. salutaris populations exhibited a shrubby growth form, probably due to frequent fires. Our current knowledge for this species supports a global IUCN status of EN A4acd. Plant conservation needs to become a higher priority both within and outside protected areas. Commercially harvested populations should be better managed through improved harvesting techniques and monitoring. Cultivation levels urgently need to be increased. Further research should be conducted on factors limiting regeneration, including the most appropriate fire regime.
- Full Text:
The impact of smart cards on South African rural pensioners' lives
- Authors: Nyoka, Zanele
- Date: 2004
- Subjects: Old age pensioners -- South Africa -- Management Smart cards South African Post Office
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:818 , http://hdl.handle.net/10962/d1008052
- Description: E-commerce technologies have many possible applications both in commercial and non-commercial operations. The development and implementation of these applications is on the increase especially by government and its agencies, for the delivery of services. Specific to this study is the distribution of old age pension benefits to recipients that reside in the rural areas of South Africa. Of importance to this study are the factors that promote and impinge on the development, implementation and acceptance of these applications. A specific project, the Pension Biometric Project was implemented by the South African Post Office in line with the government's initiatives of improving service delivery, and in response to the encroaching digital economy. The research problem is to investigate the pensioners' perception and their experience of three areas of this project, its implementation, its acceptance and its uses and impact. The research was conducted in the constructivist paradigm, using the case study research method. Three data collection methods were used, i.e. a document study of SAPO project documentation, on-site observations and interviews with pensioners. It was found that despite problems in implementation, the pensioners were accepting of the new system, although they were ignorant of the functionalities of the smart card. Consequently, few pensioners were making use of the banking facilities of the card, or had changed their economic behaviour. The study has also found that two themes are overriding all findings of the study. These two themes are ignorance and dignity. Ignorance has had a causal effect on adoption of the smart cards and dignity has been found to be a result of the project. The overriding implication of this study is that pensioners' ignorance around issues of service delivery by government and its agencies needs to be eradicated, otherwise there is no reliable way of measuring efforts against actual delivery. Also, the fact that dignity has emerged as an overriding theme needs to be deliberately strengthened, and maybe even driven as a specified objective of the Pension Biometric Project. Recommendations in this regard are provided as well as ideas for further research.
- Full Text:
- Authors: Nyoka, Zanele
- Date: 2004
- Subjects: Old age pensioners -- South Africa -- Management Smart cards South African Post Office
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:818 , http://hdl.handle.net/10962/d1008052
- Description: E-commerce technologies have many possible applications both in commercial and non-commercial operations. The development and implementation of these applications is on the increase especially by government and its agencies, for the delivery of services. Specific to this study is the distribution of old age pension benefits to recipients that reside in the rural areas of South Africa. Of importance to this study are the factors that promote and impinge on the development, implementation and acceptance of these applications. A specific project, the Pension Biometric Project was implemented by the South African Post Office in line with the government's initiatives of improving service delivery, and in response to the encroaching digital economy. The research problem is to investigate the pensioners' perception and their experience of three areas of this project, its implementation, its acceptance and its uses and impact. The research was conducted in the constructivist paradigm, using the case study research method. Three data collection methods were used, i.e. a document study of SAPO project documentation, on-site observations and interviews with pensioners. It was found that despite problems in implementation, the pensioners were accepting of the new system, although they were ignorant of the functionalities of the smart card. Consequently, few pensioners were making use of the banking facilities of the card, or had changed their economic behaviour. The study has also found that two themes are overriding all findings of the study. These two themes are ignorance and dignity. Ignorance has had a causal effect on adoption of the smart cards and dignity has been found to be a result of the project. The overriding implication of this study is that pensioners' ignorance around issues of service delivery by government and its agencies needs to be eradicated, otherwise there is no reliable way of measuring efforts against actual delivery. Also, the fact that dignity has emerged as an overriding theme needs to be deliberately strengthened, and maybe even driven as a specified objective of the Pension Biometric Project. Recommendations in this regard are provided as well as ideas for further research.
- Full Text: