The determination of the solubility of mercurous chloride at 25°C
- Authors: Dry, Mark Eberhard
- Date: 1954
- Subjects: Mercuric chloride
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4463 , http://hdl.handle.net/10962/d1011576 , Mercuric chloride
- Description: After the publication of the paper by Gledhill and Malan in which precision conductance techniques were used for the first time in the determination of the solubility of silver chloride, Dr. N.H. Perton of Christchurch College, New Zealand, wrote to Gledhill and suggested that the same methods might be rewarding if applied to the determination of the solubility of mercurous chloride. A review of the Chemical literature showed that the values for the solubility of mercurous chloride were not at all consistent. Into., p. 1
- Full Text:
- Date Issued: 1954
- Authors: Dry, Mark Eberhard
- Date: 1954
- Subjects: Mercuric chloride
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4463 , http://hdl.handle.net/10962/d1011576 , Mercuric chloride
- Description: After the publication of the paper by Gledhill and Malan in which precision conductance techniques were used for the first time in the determination of the solubility of silver chloride, Dr. N.H. Perton of Christchurch College, New Zealand, wrote to Gledhill and suggested that the same methods might be rewarding if applied to the determination of the solubility of mercurous chloride. A review of the Chemical literature showed that the values for the solubility of mercurous chloride were not at all consistent. Into., p. 1
- Full Text:
- Date Issued: 1954
A holy people: a study in the ecclesiology of Andrew Murray
- Neethling, Johann Christiaan
- Authors: Neethling, Johann Christiaan
- Date: 1975
- Subjects: Murray, Andrew, 1828-1917 , Nederduitse Gereformeerde Kerk , Nederduitsch Hervormde Kerk van Afrika -- History , Nederduitse Gereformeerde Gemeente Worcester , Nederduitse Gereformeerde Gemeente Bloemfontein , Nederduitse Gereformeerde Gemeente Wellington , Theology, Doctrinal -- South Africa -- History , Church history
- Language: English
- Type: Thesis , Bachelor , BDiv
- Identifier: vital:1287 , http://hdl.handle.net/10962/d1013592
- Description: The thesis seeks to show Andrew Murray's growing understanding of what it meant to be the elect of God in contrast to other prevailing notions. In his confrontation with the Trekker communities, the majority of whom were rigid Calvinists, stressing a divine election based on the notions of biological and cultural identity, Murray found little of the holy behaviour which ought to characterize the people of God. The elect should be seen to be the elect by their fruits. Instead there was divisiveness, discrimination, party spirit and other forms of ungodliness. Faced with the immensity of the task in identifying the true Church and building God's people up in holiness, Murray began to sense the necessity of another 'dimension' within the Church's regular means of grace of preaching, the sacraments, and discipline. The revival of 1860, focussed Murray's attention in a new and vital way on the work of the Holy Spirit in breathing new life into the Church and in empowering believers to live lives pleasing to God. The 'indiscriminate' effects of the Holy Spirit's work convinced Murray that the Gospel and thus the Church was not the possession of the white colonist, Dutch or English, but that the black and brown man had an equal claim on the Gospel and as much right to become a member of Christ's Church. Murray's understanding of the Christian life as continual abiding in Christ by the power of the indwelling Holy Spirit meant that the believer came to have the mind of Christ and to partake of His holiness. This holiness evidenced itself in the believer having Christ's concern for the lost. Mission, therefore, became this supreme end of the Church. The struggle with the forces of liberalism raised the new issue that unbelievers could no longer be simply 'heathen blacks' or English but most of all Dutch. The support of the civil courts of those disciplined by the Church brought the whole problem of ecclesiology to the fore and led Murray to the conclusion of the necessary separation of the Church from the State. Murray's discovery that in various ages, nations and Church traditions there were those with the same passionate desire for God' s holiness, led him into an increasing awareness of the catholicity of the Church. True holiness demanded the love and unity of all God's children. Murray's ecclesiology was a biblically-based one at a time when communities were beginning to be formed by other than biblical notions and principles and by a people who were trying to pack more into the notion of a people of God than Scripture gave warrant for. The emphasis for which Murray stood made for an ecclesiology that simply could not be confined.
- Full Text:
- Date Issued: 1975
- Authors: Neethling, Johann Christiaan
- Date: 1975
- Subjects: Murray, Andrew, 1828-1917 , Nederduitse Gereformeerde Kerk , Nederduitsch Hervormde Kerk van Afrika -- History , Nederduitse Gereformeerde Gemeente Worcester , Nederduitse Gereformeerde Gemeente Bloemfontein , Nederduitse Gereformeerde Gemeente Wellington , Theology, Doctrinal -- South Africa -- History , Church history
- Language: English
- Type: Thesis , Bachelor , BDiv
- Identifier: vital:1287 , http://hdl.handle.net/10962/d1013592
- Description: The thesis seeks to show Andrew Murray's growing understanding of what it meant to be the elect of God in contrast to other prevailing notions. In his confrontation with the Trekker communities, the majority of whom were rigid Calvinists, stressing a divine election based on the notions of biological and cultural identity, Murray found little of the holy behaviour which ought to characterize the people of God. The elect should be seen to be the elect by their fruits. Instead there was divisiveness, discrimination, party spirit and other forms of ungodliness. Faced with the immensity of the task in identifying the true Church and building God's people up in holiness, Murray began to sense the necessity of another 'dimension' within the Church's regular means of grace of preaching, the sacraments, and discipline. The revival of 1860, focussed Murray's attention in a new and vital way on the work of the Holy Spirit in breathing new life into the Church and in empowering believers to live lives pleasing to God. The 'indiscriminate' effects of the Holy Spirit's work convinced Murray that the Gospel and thus the Church was not the possession of the white colonist, Dutch or English, but that the black and brown man had an equal claim on the Gospel and as much right to become a member of Christ's Church. Murray's understanding of the Christian life as continual abiding in Christ by the power of the indwelling Holy Spirit meant that the believer came to have the mind of Christ and to partake of His holiness. This holiness evidenced itself in the believer having Christ's concern for the lost. Mission, therefore, became this supreme end of the Church. The struggle with the forces of liberalism raised the new issue that unbelievers could no longer be simply 'heathen blacks' or English but most of all Dutch. The support of the civil courts of those disciplined by the Church brought the whole problem of ecclesiology to the fore and led Murray to the conclusion of the necessary separation of the Church from the State. Murray's discovery that in various ages, nations and Church traditions there were those with the same passionate desire for God' s holiness, led him into an increasing awareness of the catholicity of the Church. True holiness demanded the love and unity of all God's children. Murray's ecclesiology was a biblically-based one at a time when communities were beginning to be formed by other than biblical notions and principles and by a people who were trying to pack more into the notion of a people of God than Scripture gave warrant for. The emphasis for which Murray stood made for an ecclesiology that simply could not be confined.
- Full Text:
- Date Issued: 1975
A study of germination and flowering in Cichorium intybus. L
- Authors: Minnaar, Hugo Roelof
- Date: 1985
- Subjects: Chicory -- South Africa Germination Seeds -- Development Plants -- Flowering of
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4178 , http://hdl.handle.net/10962/d1002027
- Description: Chicory (Cichorium intybus L) is a deep rooted biennial (or weakly perennial) composite that is grown as an annual in South Africa for its parsnip-like root. In its wild state the plant is a perennial with thin fibrous roots, but, through selection and propagation, cultivars with large, fleshy roots have been developed. From a purely horticultural standpoint, chicory is of interest as a pot-herb, a salad plant and as a root (Bailey, 1942) . As a root, the chicory plant represents an important article of commerce. In South Africa, the plants are grown virtually exclusively for their roots which, after drying, roasting and grinding, are used as an additive to, or substitute for, coffee (Introduction p. 11)
- Full Text:
- Date Issued: 1985
- Authors: Minnaar, Hugo Roelof
- Date: 1985
- Subjects: Chicory -- South Africa Germination Seeds -- Development Plants -- Flowering of
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4178 , http://hdl.handle.net/10962/d1002027
- Description: Chicory (Cichorium intybus L) is a deep rooted biennial (or weakly perennial) composite that is grown as an annual in South Africa for its parsnip-like root. In its wild state the plant is a perennial with thin fibrous roots, but, through selection and propagation, cultivars with large, fleshy roots have been developed. From a purely horticultural standpoint, chicory is of interest as a pot-herb, a salad plant and as a root (Bailey, 1942) . As a root, the chicory plant represents an important article of commerce. In South Africa, the plants are grown virtually exclusively for their roots which, after drying, roasting and grinding, are used as an additive to, or substitute for, coffee (Introduction p. 11)
- Full Text:
- Date Issued: 1985
A study of universal algebras in fuzzy set theory
- Authors: Murali, V
- Date: 1988
- Subjects: Fuzzy sets Algebra, Universal
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5394 , http://hdl.handle.net/10962/d1001983
- Description: This thesis attempts a synthesis of two important and fast developing branches of mathematics, namely universal algebra and fuzzy set theory. Given an abstract algebra [X,F] where X is a non-empty set and F is a set of finitary operations on X, a fuzzy algebra [I×,F] is constructed by extending operations on X to that on I×, the set of fuzzy subsets of X (I denotes the unit interval), using Zadeh's extension principle. Homomorphisms between fuzzy algebras are defined and discussed. Fuzzy subalgebras of an algebra are defined to be elements of a fuzzy algebra which respect the extended algebra operations under inclusion of fuzzy subsets. The family of fuzzy subalgebras of an algebra is an algebraic closure system in I×. Thus the set of fuzzy subalgebras is a complete lattice. A fuzzy equivalence relation on a set is defined and a partition of such a relation into a class of fuzzy subsets is derived. Using these ideas, fuzzy functions between sets, fuzzy congruence relations, and fuzzy homomorphisms are defined. The kernels of fuzzy homomorphisms are proved to be fuzzy congruence relations, paving the way for the fuzzy isomorphism theorem. Finally, we sketch some ideas on free fuzzy subalgebras and polynomial algebras. In a nutshell, we can say that this thesis treats the central ideas of universal algebras, namely subalgebras, homomorphisms, equivalence and congruence relations, isomorphism theorems and free algebra in the fuzzy set theory setting
- Full Text:
- Date Issued: 1988
- Authors: Murali, V
- Date: 1988
- Subjects: Fuzzy sets Algebra, Universal
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5394 , http://hdl.handle.net/10962/d1001983
- Description: This thesis attempts a synthesis of two important and fast developing branches of mathematics, namely universal algebra and fuzzy set theory. Given an abstract algebra [X,F] where X is a non-empty set and F is a set of finitary operations on X, a fuzzy algebra [I×,F] is constructed by extending operations on X to that on I×, the set of fuzzy subsets of X (I denotes the unit interval), using Zadeh's extension principle. Homomorphisms between fuzzy algebras are defined and discussed. Fuzzy subalgebras of an algebra are defined to be elements of a fuzzy algebra which respect the extended algebra operations under inclusion of fuzzy subsets. The family of fuzzy subalgebras of an algebra is an algebraic closure system in I×. Thus the set of fuzzy subalgebras is a complete lattice. A fuzzy equivalence relation on a set is defined and a partition of such a relation into a class of fuzzy subsets is derived. Using these ideas, fuzzy functions between sets, fuzzy congruence relations, and fuzzy homomorphisms are defined. The kernels of fuzzy homomorphisms are proved to be fuzzy congruence relations, paving the way for the fuzzy isomorphism theorem. Finally, we sketch some ideas on free fuzzy subalgebras and polynomial algebras. In a nutshell, we can say that this thesis treats the central ideas of universal algebras, namely subalgebras, homomorphisms, equivalence and congruence relations, isomorphism theorems and free algebra in the fuzzy set theory setting
- Full Text:
- Date Issued: 1988
History reading comprehension in black secondary schools : a Ciskei study
- Authors: Poswa, Mandisa
- Date: 1993
- Subjects: History -- Study and teaching (Secondary) -- South Africa -- Ciskei
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1555 , http://hdl.handle.net/10962/d1003437
- Description: This thesis examines briefly the problems of learning and understanding history when the subject is taught through the medium of a second language. It assesses the difficulty levels (for first language speakers) of the history textbooks commonly used in Ciskei secondary schools and considers the implications of these levels for second language speakers. It assesses the ability of 400 pupils in standard 8 and standard 10 to comprehend an English text which is deliberately written at a lower level of difficulty than that of the current secondary school texts. Comparisons are made of the comprehension scores of those pupils whose answers are written in English with those who are allowed to answer in Xhosa on questions based on the simple text. Finally, it compares the quality of the pupils' answers in Xhosa and English. Tentative recommendations are made about the language implications of history teaching which emerge from the results of the research.
- Full Text:
- Date Issued: 1993
- Authors: Poswa, Mandisa
- Date: 1993
- Subjects: History -- Study and teaching (Secondary) -- South Africa -- Ciskei
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1555 , http://hdl.handle.net/10962/d1003437
- Description: This thesis examines briefly the problems of learning and understanding history when the subject is taught through the medium of a second language. It assesses the difficulty levels (for first language speakers) of the history textbooks commonly used in Ciskei secondary schools and considers the implications of these levels for second language speakers. It assesses the ability of 400 pupils in standard 8 and standard 10 to comprehend an English text which is deliberately written at a lower level of difficulty than that of the current secondary school texts. Comparisons are made of the comprehension scores of those pupils whose answers are written in English with those who are allowed to answer in Xhosa on questions based on the simple text. Finally, it compares the quality of the pupils' answers in Xhosa and English. Tentative recommendations are made about the language implications of history teaching which emerge from the results of the research.
- Full Text:
- Date Issued: 1993
Small-scale fisheries as a vehicle for rural development : a case study of two villages in the former Ciskei, Eastern Cape Province, South Africa
- Authors: Seti, Simpiwe
- Date: 2003
- Subjects: Small-scale fisheries -- South Africa -- Eastern Cape Fisheries -- South Africa -- Eastern Cape Fishes -- South Africa -- Eastern Cape Rural development -- South Africa -- Eastern Cape Fish trade -- Developing countries Fisheries, Cooperative -- Developing countries
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3346 , http://hdl.handle.net/10962/d1006016
- Description: This thesis examines small-scale rural fisheries which were initiated in two villages by the Department of Ichthyology and Fisheries in conjunction with the Institute of Social and Economic Research in 1997. The main objective for undertaking the study was to determine the potential of the fisheries to serve as viable and sustainable options that could contribute towards rural development in the area of study. To examine the contribution made by the small-scale fisheries towards rural development in the villages, it is imperative to have an understanding of the context in which they were established as well as the prospects for sustainable development. It is argued in this study that despite the significant contribution made by inland rural fisheries in improving rural livelihoods they are still accorded minimal support and attention in South Africa. As an illustration of the important role played by rural fisheries, case studies from Malawi and Zimbabwe have been drawn into the study with a view to providing lessons for rural areas of South Africa. The study took place at a time when natural resources in the villages were significantly declining and environmental degradation reaching uncontrollable proportions, so there is an urgent need to secure an alternative mode of subsistence for the population in the villages. Development interventions by the state and non-governmental organisations in the study area have not been sustainable and they collapsed within a short period of time. A case in point is the Tyefu irrigation scheme, which was initiated in the villages but, owing to various factors, it failed leaving the villagers with a diminished mode of subsistence, thus providing the impetus for the implementation of small-scale rural fisheries. In order for small-scale fisheries to be sustainable it is essential to adopt models that are aimed at sound natural resource use and management. This study has raised various issues pertinent to natural resource use and management in the study area. A model for management of natural resources that involves and aims to empower local communities in the management of the fisheries is presented in the study. It has also been demonstrated that rural fisheries in the study area comply with the model. Finally, the study draws the conclusion that small-scale fisheries in the villages contribute towards rural development, however, there are constraints that need to be eradicated.
- Full Text:
- Date Issued: 2003
- Authors: Seti, Simpiwe
- Date: 2003
- Subjects: Small-scale fisheries -- South Africa -- Eastern Cape Fisheries -- South Africa -- Eastern Cape Fishes -- South Africa -- Eastern Cape Rural development -- South Africa -- Eastern Cape Fish trade -- Developing countries Fisheries, Cooperative -- Developing countries
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3346 , http://hdl.handle.net/10962/d1006016
- Description: This thesis examines small-scale rural fisheries which were initiated in two villages by the Department of Ichthyology and Fisheries in conjunction with the Institute of Social and Economic Research in 1997. The main objective for undertaking the study was to determine the potential of the fisheries to serve as viable and sustainable options that could contribute towards rural development in the area of study. To examine the contribution made by the small-scale fisheries towards rural development in the villages, it is imperative to have an understanding of the context in which they were established as well as the prospects for sustainable development. It is argued in this study that despite the significant contribution made by inland rural fisheries in improving rural livelihoods they are still accorded minimal support and attention in South Africa. As an illustration of the important role played by rural fisheries, case studies from Malawi and Zimbabwe have been drawn into the study with a view to providing lessons for rural areas of South Africa. The study took place at a time when natural resources in the villages were significantly declining and environmental degradation reaching uncontrollable proportions, so there is an urgent need to secure an alternative mode of subsistence for the population in the villages. Development interventions by the state and non-governmental organisations in the study area have not been sustainable and they collapsed within a short period of time. A case in point is the Tyefu irrigation scheme, which was initiated in the villages but, owing to various factors, it failed leaving the villagers with a diminished mode of subsistence, thus providing the impetus for the implementation of small-scale rural fisheries. In order for small-scale fisheries to be sustainable it is essential to adopt models that are aimed at sound natural resource use and management. This study has raised various issues pertinent to natural resource use and management in the study area. A model for management of natural resources that involves and aims to empower local communities in the management of the fisheries is presented in the study. It has also been demonstrated that rural fisheries in the study area comply with the model. Finally, the study draws the conclusion that small-scale fisheries in the villages contribute towards rural development, however, there are constraints that need to be eradicated.
- Full Text:
- Date Issued: 2003
Consolidating democracy, building civil society : the South African Council of Churches in post-apartheid South Africa and its policy of critical solidarity with the state
- Authors: Joseph, Stacey-Leigh
- Date: 2005
- Subjects: South African Council of Churches Church and state -- South Africa Christianity and politics -- South Africa Apartheid -- Religious aspects -- South Africa AIDS (Disease) -- Government policy -- South Africa Debts, External -- South Africa South Africa -- Foreign relations -- Zimbabwe South Africa -- Politics and government -- 1994
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:2874 , http://hdl.handle.net/10962/d1007957
- Description: The South African Council of Churches (SACC) played an extremely crucial role during the struggle against apartheid. The role of the SACC was first and foremost to provide a voice for the voiceless. It managed, among other tasks, to actively fill the void left by movements banned by the illegitimate apartheid government. As a result of its fight against the inequalities that existed in South Africa, its work adopted a political character. In the aftermath of post-apartheid South Africa, the SACC was left with the task of redefining its role within South African society and civil society, specifically. The euphoric sentiment in the mid-1990s was in part reflected in the SACC. However, the conclusion reached by the Council in 1995 was that it would also play a role of 'critical solidarity' which essentially meant that it would not shy away from attacking the government when the need arose. Since 1994, the South African government has implemented a number of policies that do not appear to be in the immediate interest of the majority of South African citizens atld have brought church and state into conflict. This thesis attempts to tackle three issues which are pertinent to the South African situation and which shed light on state-civil society interactions. These issues are HIV I Aids, the question of odious debt and the Zimbabwe crisis. By using both primary and secondary sources, the SACC's responses to government's handling of these matters will be compared with the responses of the South African Catholic Bishops Conference in order to determine their relationships with government. The conclusion of this investigation is that the SACC has in fact managed to maintain a position of critical solidarity. It has been faced with numerous challenges with regard to maintaining the fragile boundary of alliance with government on the one hand, and becoming anti-government on the other. However, by forming alliances with other civil society actors as well as fostering a relationship with government in order to facilitate mediation this dissertation argues that the SACC has become an essential member of South Africa's vibrant civil society.
- Full Text:
- Date Issued: 2005
- Authors: Joseph, Stacey-Leigh
- Date: 2005
- Subjects: South African Council of Churches Church and state -- South Africa Christianity and politics -- South Africa Apartheid -- Religious aspects -- South Africa AIDS (Disease) -- Government policy -- South Africa Debts, External -- South Africa South Africa -- Foreign relations -- Zimbabwe South Africa -- Politics and government -- 1994
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:2874 , http://hdl.handle.net/10962/d1007957
- Description: The South African Council of Churches (SACC) played an extremely crucial role during the struggle against apartheid. The role of the SACC was first and foremost to provide a voice for the voiceless. It managed, among other tasks, to actively fill the void left by movements banned by the illegitimate apartheid government. As a result of its fight against the inequalities that existed in South Africa, its work adopted a political character. In the aftermath of post-apartheid South Africa, the SACC was left with the task of redefining its role within South African society and civil society, specifically. The euphoric sentiment in the mid-1990s was in part reflected in the SACC. However, the conclusion reached by the Council in 1995 was that it would also play a role of 'critical solidarity' which essentially meant that it would not shy away from attacking the government when the need arose. Since 1994, the South African government has implemented a number of policies that do not appear to be in the immediate interest of the majority of South African citizens atld have brought church and state into conflict. This thesis attempts to tackle three issues which are pertinent to the South African situation and which shed light on state-civil society interactions. These issues are HIV I Aids, the question of odious debt and the Zimbabwe crisis. By using both primary and secondary sources, the SACC's responses to government's handling of these matters will be compared with the responses of the South African Catholic Bishops Conference in order to determine their relationships with government. The conclusion of this investigation is that the SACC has in fact managed to maintain a position of critical solidarity. It has been faced with numerous challenges with regard to maintaining the fragile boundary of alliance with government on the one hand, and becoming anti-government on the other. However, by forming alliances with other civil society actors as well as fostering a relationship with government in order to facilitate mediation this dissertation argues that the SACC has become an essential member of South Africa's vibrant civil society.
- Full Text:
- Date Issued: 2005
The relationship between individual needs and the choice of incentive schemes in the South African Breweries
- Authors: Long, Allan
- Date: 2007
- Subjects: South African Breweries Ltd. Incentives in industry -- South Africa Workers' compensation -- South Africa Performance -- Management Employee motivation
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:800 , http://hdl.handle.net/10962/d1006119
- Description: After careful review of all the relevant literature pertaining to motivation, performance management and compensation in the form of incentives, this thesis focuses primarily on determining whether a statistically significant relationship exists between individual needs and the choice of an incentive scheme option. The secondary aims of the research are to determine whether: A relationship exists between the job grade of an individual and the choice of an incentive scheme. A particular incentive scheme option is preferred by the employees in The South African Breweries (SAB). A particular preference exists, and if so, to make recommendations to SAB for consideration as alternatives to their existing incentive scheme options. After collation of the survey data from the respondents in the sample, the analysis and discussion of the results determined that no significant relationship exists between individual needs and the choice of an incentive scheme option. It was, however, determined that a significant relationship exists between the grade of the employees in SAB and their choice of an incentive scheme. 81% of all respondents indicated a desire for shares as an option in their Short Term Incentives (STI) which indicates a desire for shares in some form or another and may well indicate a level of confidence and commitment by the employees to the organisation. Although the research hypothesis was not proven, significant insights into remuneration within SAB was obtained, which has resulted in recommendations being made for further research into the option of shares in some form or another in the organisation. A further recommendation for SAB is to consider some form of share options for all employees in the organisation. As many other organisations that are performing at remarkable levels attest this performance to share ownership and the behaviour that emanates from it, it would be in the interests of SAB to further investigate the issue as it may improve performance, ownership and retention within the company.
- Full Text:
- Date Issued: 2007
- Authors: Long, Allan
- Date: 2007
- Subjects: South African Breweries Ltd. Incentives in industry -- South Africa Workers' compensation -- South Africa Performance -- Management Employee motivation
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:800 , http://hdl.handle.net/10962/d1006119
- Description: After careful review of all the relevant literature pertaining to motivation, performance management and compensation in the form of incentives, this thesis focuses primarily on determining whether a statistically significant relationship exists between individual needs and the choice of an incentive scheme option. The secondary aims of the research are to determine whether: A relationship exists between the job grade of an individual and the choice of an incentive scheme. A particular incentive scheme option is preferred by the employees in The South African Breweries (SAB). A particular preference exists, and if so, to make recommendations to SAB for consideration as alternatives to their existing incentive scheme options. After collation of the survey data from the respondents in the sample, the analysis and discussion of the results determined that no significant relationship exists between individual needs and the choice of an incentive scheme option. It was, however, determined that a significant relationship exists between the grade of the employees in SAB and their choice of an incentive scheme. 81% of all respondents indicated a desire for shares as an option in their Short Term Incentives (STI) which indicates a desire for shares in some form or another and may well indicate a level of confidence and commitment by the employees to the organisation. Although the research hypothesis was not proven, significant insights into remuneration within SAB was obtained, which has resulted in recommendations being made for further research into the option of shares in some form or another in the organisation. A further recommendation for SAB is to consider some form of share options for all employees in the organisation. As many other organisations that are performing at remarkable levels attest this performance to share ownership and the behaviour that emanates from it, it would be in the interests of SAB to further investigate the issue as it may improve performance, ownership and retention within the company.
- Full Text:
- Date Issued: 2007
The tuba in solo and ensemble repertory : a critical perspective
- Authors: Bower, Danel
- Date: 2008
- Subjects: Tuba -- Performance , Tuba -- History and criticism
- Language: English
- Type: Thesis , Masters , MMus
- Identifier: vital:8515 , http://hdl.handle.net/10948/759 , http://hdl.handle.net/10948/d1012064 , Tuba -- Performance , Tuba -- History and criticism
- Description: The topic of this research is to explore various aspects pertaining to the tuba and its role in music. The role of the tuba in modern performance practice is greatly dependent on the history of the tuba and the different roles that were fulfilled in the various eras. The study begins with an investigation into the most important predecessors of the tuba – the most prominent thereof being the ophicleide. The next field of study includes the role of the tuba in orchestras in different countries as well as the role that the tuba fulfills in various ensembles. There is a wide variety of brass instruments that were manufactured in the past and are still being produced today. Various improvements and adaptations of the tuba are listed and studied. Next the tuba is considered in its capacity as a solo instrument and the fact that the tuba can exist as a solo instrument is motivated. Even though it might not be evident that there are a large number of composers for this instrument, some of the most respected and influential composers of tuba music of all time are sighted in this study. Several famous and celebrated tuba players are mentioned and their accomplishments listed. Finally the three practical music examination institutions in South Africa are studied. Lists are compiled to assess the quality of the different examination options between these institutions and provide a suggestion of a preferred option.
- Full Text:
- Date Issued: 2008
- Authors: Bower, Danel
- Date: 2008
- Subjects: Tuba -- Performance , Tuba -- History and criticism
- Language: English
- Type: Thesis , Masters , MMus
- Identifier: vital:8515 , http://hdl.handle.net/10948/759 , http://hdl.handle.net/10948/d1012064 , Tuba -- Performance , Tuba -- History and criticism
- Description: The topic of this research is to explore various aspects pertaining to the tuba and its role in music. The role of the tuba in modern performance practice is greatly dependent on the history of the tuba and the different roles that were fulfilled in the various eras. The study begins with an investigation into the most important predecessors of the tuba – the most prominent thereof being the ophicleide. The next field of study includes the role of the tuba in orchestras in different countries as well as the role that the tuba fulfills in various ensembles. There is a wide variety of brass instruments that were manufactured in the past and are still being produced today. Various improvements and adaptations of the tuba are listed and studied. Next the tuba is considered in its capacity as a solo instrument and the fact that the tuba can exist as a solo instrument is motivated. Even though it might not be evident that there are a large number of composers for this instrument, some of the most respected and influential composers of tuba music of all time are sighted in this study. Several famous and celebrated tuba players are mentioned and their accomplishments listed. Finally the three practical music examination institutions in South Africa are studied. Lists are compiled to assess the quality of the different examination options between these institutions and provide a suggestion of a preferred option.
- Full Text:
- Date Issued: 2008
Becoming a business journalist in Malawi: a case study of The Daily Times and The Nation newspapers
- Authors: Manjawira, Ellard Spencer
- Date: 2010 , 2013-07-17
- Subjects: Journalists -- Malawi Journalism -- Study and teaching -- Malawi Journalists -- Training of -- Malawi Journalists -- Education -- Malawi
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3506 , http://hdl.handle.net/10962/d1007440
- Description: In the past few decades, the proportion of business news compared to general news has increased tremendously across all media platforms in Africa. While the critical role played by business journalism is recognised, little is known about the people who write and report such news. Most studies on business reporting have tended to focus on analysing the content of business news, rather than the specific processes through which business journalists are socialized and trained. The findings of this study are drawn mainly from in-depth interviews with business reporters and editors at two leading newspapers in Malawi, The Daily Times and The Nation. Three major findings emerge trom the study data. First, business journalists vary in their educational and professional backgrounds, as well as the reasons for working on this beat. Second, the majority of them have no prerequisite formal education and training in business journalism and, therefore, have little knowledge and skills about what constitute good business journalism. Third, professionalism in the sub-field is constrained by a host of factors, influence of advertisers being the critical one. The study recommends that business reporting become an integral component of journalism education and training programmes to adequately prepare future generations of business journalists. In addition there is need for media houses to devise strategies to counter obstacles that business journalists face for them to effectively contribute to political economy debate. , KMBT_363
- Full Text:
- Date Issued: 2010
- Authors: Manjawira, Ellard Spencer
- Date: 2010 , 2013-07-17
- Subjects: Journalists -- Malawi Journalism -- Study and teaching -- Malawi Journalists -- Training of -- Malawi Journalists -- Education -- Malawi
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3506 , http://hdl.handle.net/10962/d1007440
- Description: In the past few decades, the proportion of business news compared to general news has increased tremendously across all media platforms in Africa. While the critical role played by business journalism is recognised, little is known about the people who write and report such news. Most studies on business reporting have tended to focus on analysing the content of business news, rather than the specific processes through which business journalists are socialized and trained. The findings of this study are drawn mainly from in-depth interviews with business reporters and editors at two leading newspapers in Malawi, The Daily Times and The Nation. Three major findings emerge trom the study data. First, business journalists vary in their educational and professional backgrounds, as well as the reasons for working on this beat. Second, the majority of them have no prerequisite formal education and training in business journalism and, therefore, have little knowledge and skills about what constitute good business journalism. Third, professionalism in the sub-field is constrained by a host of factors, influence of advertisers being the critical one. The study recommends that business reporting become an integral component of journalism education and training programmes to adequately prepare future generations of business journalists. In addition there is need for media houses to devise strategies to counter obstacles that business journalists face for them to effectively contribute to political economy debate. , KMBT_363
- Full Text:
- Date Issued: 2010
The presentation of the orphan child in eighteenth and early nineteenth century English literature in a selection of William Blake's 'Songs of innocence and experience', and in Charlotte Brontë's 'Jane Eyre', and Emily Brontë's 'Wuthering Heights'
- Authors: Singh, Jyoti
- Date: 2010 , 2013-07-18
- Subjects: Blake, William, 1757-1827 -- Songs of innocence and of experience -- Characters -- Orphans Blake, William, 1757-1827 -- Criticism and interpretation Brontë, Charlotte, 1816-1855 -- Jane Eyre -- Characters -- Orphans Brontë, Charlotte, 1816-1855 -- Criticism and interpretation Brontë, Emily, 1818-1848 -- Wuthering Heights -- Characters -- Orphans Brontë, Emily, 1818-1848 -- Criticism and interpretation Orphans in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2267 , http://hdl.handle.net/10962/d1005628
- Description: This thesis is a study of the presentation of the orphan child in eighteenth and early nineteenth century English literature, and focuses on William Blake's Songs of Innocence and Experience, Charlotte Bronte's Jane Eyre, and Emily Bronte's Wuthering Heights. It is concerned with assessing the extent to which the orphan children in each of the works are liberated from familial and social constraints and structures and to what end. Chapter One examines the major thematic concern of the extent to which the motif of the orphan child represents a wronged innocent, and whether this symbol can also, or alternatively, be presented as a revolutionary force that challenges society's status quo in Blake's Songs of Innocence and Experience. Chapter Two considers the significance of the child "lost" and "found", which forms the explicit subject of six of Blake's Songs of Innocence and Experience and explores the treatment of these conditions, and their differences and consequences for the children concerned. Chapter Three focuses on Charlotte Bronte's depiction of the orphan in Jane Eyre, which presents two models of the orphan child: the protagonist Jane, and Helen Burns. The chapter examines these two models and their responses to orphan-hood in a hostile world where orphans are mistreated by family and society alike. Chapter Four determines whether the orphan constitutes a subversive threat to the family in Emily Bronte's Wuthering Heights and also explores the notion that, although orphan-hood often entails liberation from adult guardians, it also comprises vulnerability and exposure. The thesis concludes by considering the extent to which orphan-hood can involve a form of liberation from the confines of social structures, and what this liberation constitutes for each of the three authors.
- Full Text:
- Date Issued: 2010
- Authors: Singh, Jyoti
- Date: 2010 , 2013-07-18
- Subjects: Blake, William, 1757-1827 -- Songs of innocence and of experience -- Characters -- Orphans Blake, William, 1757-1827 -- Criticism and interpretation Brontë, Charlotte, 1816-1855 -- Jane Eyre -- Characters -- Orphans Brontë, Charlotte, 1816-1855 -- Criticism and interpretation Brontë, Emily, 1818-1848 -- Wuthering Heights -- Characters -- Orphans Brontë, Emily, 1818-1848 -- Criticism and interpretation Orphans in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2267 , http://hdl.handle.net/10962/d1005628
- Description: This thesis is a study of the presentation of the orphan child in eighteenth and early nineteenth century English literature, and focuses on William Blake's Songs of Innocence and Experience, Charlotte Bronte's Jane Eyre, and Emily Bronte's Wuthering Heights. It is concerned with assessing the extent to which the orphan children in each of the works are liberated from familial and social constraints and structures and to what end. Chapter One examines the major thematic concern of the extent to which the motif of the orphan child represents a wronged innocent, and whether this symbol can also, or alternatively, be presented as a revolutionary force that challenges society's status quo in Blake's Songs of Innocence and Experience. Chapter Two considers the significance of the child "lost" and "found", which forms the explicit subject of six of Blake's Songs of Innocence and Experience and explores the treatment of these conditions, and their differences and consequences for the children concerned. Chapter Three focuses on Charlotte Bronte's depiction of the orphan in Jane Eyre, which presents two models of the orphan child: the protagonist Jane, and Helen Burns. The chapter examines these two models and their responses to orphan-hood in a hostile world where orphans are mistreated by family and society alike. Chapter Four determines whether the orphan constitutes a subversive threat to the family in Emily Bronte's Wuthering Heights and also explores the notion that, although orphan-hood often entails liberation from adult guardians, it also comprises vulnerability and exposure. The thesis concludes by considering the extent to which orphan-hood can involve a form of liberation from the confines of social structures, and what this liberation constitutes for each of the three authors.
- Full Text:
- Date Issued: 2010
The role of cluster centre principals in the Ohangwena education region in Namibia
- Authors: Nghatanga, Ponny Haggai
- Date: 2011
- Subjects: School management and organization -- Namibia -- Ohangwena School principals -- Namibia -- Ohangwena Educational leadership -- Namibia -- Ohangwena Educational change -- Namibia -- Ohangwena
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1748 , http://hdl.handle.net/10962/d1003632
- Description: The Namibian Ministry of Education introduced the School Clustering System (SCS) in 1996. The system entails the grouping of schools into clusters to facilitate the sharing of resources and expertise. One school in a group is selected to serve as the Cluster Centre and the principal of the centre is identified as the Cluster Centre Principal (CCP). This has created a new level of educational leadership which is still relatively under-researched and the primary purpose of this study is to investigate the perceptions of this new role since it is perceived to be pivotal to the effective functioning of the cluster. This study is an interpretive case study of Cluster Centres in the Komesho Circuit in the Ohangwena Educational Region. Three data collection instruments were used, namely document analysis, observation and interviews. The collected data provided insight into participants' views on the role of Cluster Centre Principals (CCPs), which shed light on the challenges faCing the roles of CCPs. The findings revealed that respondents welcomed the decentralisation of an education system that involves cluster members and parents in decision making. Furthermore, the perceived role of CCPs is perceived as delegation through participative leadership and management approaches. This involves groups in teamwork to enhance the quality of teaching and learning. The study has, however, also exposed tensions surrounding the role and function of CCPs. This is partly because the role has not been formalised and is perceived as existing in a legal vacuum. This study will benefit the Cluster Centre Principals, Inspectors of Education, Advisory Teachers, non-governmental Organisations, the community and the Ministry of Education by placing the role of Cluster Centre Principals in perspective.
- Full Text:
- Date Issued: 2011
- Authors: Nghatanga, Ponny Haggai
- Date: 2011
- Subjects: School management and organization -- Namibia -- Ohangwena School principals -- Namibia -- Ohangwena Educational leadership -- Namibia -- Ohangwena Educational change -- Namibia -- Ohangwena
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1748 , http://hdl.handle.net/10962/d1003632
- Description: The Namibian Ministry of Education introduced the School Clustering System (SCS) in 1996. The system entails the grouping of schools into clusters to facilitate the sharing of resources and expertise. One school in a group is selected to serve as the Cluster Centre and the principal of the centre is identified as the Cluster Centre Principal (CCP). This has created a new level of educational leadership which is still relatively under-researched and the primary purpose of this study is to investigate the perceptions of this new role since it is perceived to be pivotal to the effective functioning of the cluster. This study is an interpretive case study of Cluster Centres in the Komesho Circuit in the Ohangwena Educational Region. Three data collection instruments were used, namely document analysis, observation and interviews. The collected data provided insight into participants' views on the role of Cluster Centre Principals (CCPs), which shed light on the challenges faCing the roles of CCPs. The findings revealed that respondents welcomed the decentralisation of an education system that involves cluster members and parents in decision making. Furthermore, the perceived role of CCPs is perceived as delegation through participative leadership and management approaches. This involves groups in teamwork to enhance the quality of teaching and learning. The study has, however, also exposed tensions surrounding the role and function of CCPs. This is partly because the role has not been formalised and is perceived as existing in a legal vacuum. This study will benefit the Cluster Centre Principals, Inspectors of Education, Advisory Teachers, non-governmental Organisations, the community and the Ministry of Education by placing the role of Cluster Centre Principals in perspective.
- Full Text:
- Date Issued: 2011
Movements of sub-adult sicklefin lemon sharks Negaprion acutidens in a remote Indian Ocean atoll
- Authors: Filmalter, John David
- Date: 2012
- Subjects: Silky shark , Silky shark -- Habitat , Sharks -- Amirante Islands (Seychelles)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5383 , http://hdl.handle.net/10962/d1018229
- Description: The sicklefin lemon shark Negaprion acutidens is a large-bodied (> 3m) coastal shark species, widely distributed in tropical and sub-tropical Indo-Pacific waters. Despite its large size and wide distribution, very little is known about its movement behaviour throughout ontogeny. The primary aim of this thesis was to gain an understanding of the movements of sub-adult N. acutidens, in and around the St. Joseph Atoll, Republic of Seychelles, to facilitate the effective conservation of this vulnerable species. A total of 22 sharks (139 – 202 cm TL) were equipped with coded acoustic transmitters and passively monitored using moored acoustic receivers for a period of 20 month from March 2009 to October 2010. The use of passive acoustic telemetry arrays to study behavioural ecology has increased in popularity in recent years and been successfully applied to study a host of teleost and elasmobranch species in a diversity of habitats, ranging from sheltered estuaries to the offshore pelagic environment. However, the practicalities of designing an effective network of receivers to optimally monitor animal movements can be challenging. In this study the receiver array was optimised through a series of incremental steps to achieve an efficient design that allowed for the specific objectives to be addressed. The specific objectives of this study were to i) gain an understanding of the long term space use patterns and site fidelity of sub-adult N. acutidens within degree of use of the St. Joseph Atoll lagoon and surrounding habitats, and ii) investigate their short term behavioural patterns in response to natural rhythmic cycles. The important role the atoll plays in the sub-adult stage of this species was demonstrated by the very low numbers of detections outside the atoll compared to the very large numbers of detections inside the atoll. Over the course of a year the tagged sharks showed a high degree of site fidelity to the atoll, with 79 – 100% of the individuals detected during each month and 50% being detected on a near daily basis. This result provides testimony of the nursery role of the atoll and importance of these habitats in the early life history for this species. Individual area use was generally found to be restricted to the eastern part of the atoll incorporating a portion of the central deep lagoon and a nearby adjacent area of the sand flats. The movements of sub-adult N. acutidens on and off of the shallow flats surrounding the central lagoon (likely for foraging) were found to be strongly influenced by the tidal height and the diel cycle. Tagged sharks were found to utilise the flats more regularly when the tidal height was greater than 90 cm and particularly more so during the night and early morning than during daylight times. The combined results of this study expose the vulnerability of this species to rapid local depletion. Similarly, the effectiveness of spatial management measures, such as no-take marine protected areas is highlighted as an efficient tool for the future conservation of this species. In the St. Joseph Atoll in particular, the use of a multi-levelled protection approach, where the eastern portion on the atoll is completely restricted while the remaining area is utilized for non-consumptive tourism activities, could be highly effective. Future research should investigate changes in area use throughout the ontogeny of this species as well improve the understanding of the breeding site fidelity and population size of reproductive females using the St. Joseph Atoll.
- Full Text:
- Date Issued: 2012
- Authors: Filmalter, John David
- Date: 2012
- Subjects: Silky shark , Silky shark -- Habitat , Sharks -- Amirante Islands (Seychelles)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5383 , http://hdl.handle.net/10962/d1018229
- Description: The sicklefin lemon shark Negaprion acutidens is a large-bodied (> 3m) coastal shark species, widely distributed in tropical and sub-tropical Indo-Pacific waters. Despite its large size and wide distribution, very little is known about its movement behaviour throughout ontogeny. The primary aim of this thesis was to gain an understanding of the movements of sub-adult N. acutidens, in and around the St. Joseph Atoll, Republic of Seychelles, to facilitate the effective conservation of this vulnerable species. A total of 22 sharks (139 – 202 cm TL) were equipped with coded acoustic transmitters and passively monitored using moored acoustic receivers for a period of 20 month from March 2009 to October 2010. The use of passive acoustic telemetry arrays to study behavioural ecology has increased in popularity in recent years and been successfully applied to study a host of teleost and elasmobranch species in a diversity of habitats, ranging from sheltered estuaries to the offshore pelagic environment. However, the practicalities of designing an effective network of receivers to optimally monitor animal movements can be challenging. In this study the receiver array was optimised through a series of incremental steps to achieve an efficient design that allowed for the specific objectives to be addressed. The specific objectives of this study were to i) gain an understanding of the long term space use patterns and site fidelity of sub-adult N. acutidens within degree of use of the St. Joseph Atoll lagoon and surrounding habitats, and ii) investigate their short term behavioural patterns in response to natural rhythmic cycles. The important role the atoll plays in the sub-adult stage of this species was demonstrated by the very low numbers of detections outside the atoll compared to the very large numbers of detections inside the atoll. Over the course of a year the tagged sharks showed a high degree of site fidelity to the atoll, with 79 – 100% of the individuals detected during each month and 50% being detected on a near daily basis. This result provides testimony of the nursery role of the atoll and importance of these habitats in the early life history for this species. Individual area use was generally found to be restricted to the eastern part of the atoll incorporating a portion of the central deep lagoon and a nearby adjacent area of the sand flats. The movements of sub-adult N. acutidens on and off of the shallow flats surrounding the central lagoon (likely for foraging) were found to be strongly influenced by the tidal height and the diel cycle. Tagged sharks were found to utilise the flats more regularly when the tidal height was greater than 90 cm and particularly more so during the night and early morning than during daylight times. The combined results of this study expose the vulnerability of this species to rapid local depletion. Similarly, the effectiveness of spatial management measures, such as no-take marine protected areas is highlighted as an efficient tool for the future conservation of this species. In the St. Joseph Atoll in particular, the use of a multi-levelled protection approach, where the eastern portion on the atoll is completely restricted while the remaining area is utilized for non-consumptive tourism activities, could be highly effective. Future research should investigate changes in area use throughout the ontogeny of this species as well improve the understanding of the breeding site fidelity and population size of reproductive females using the St. Joseph Atoll.
- Full Text:
- Date Issued: 2012
The effectiveness of internal newsletters: case study of Transnet Freight Rail's platform
- Matshoba, Thembekile Phillinah
- Authors: Matshoba, Thembekile Phillinah
- Date: 2012
- Subjects: Newsletters , Business communication
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8420 , http://hdl.handle.net/10948/d1015672
- Description: The research is based on a case study of an internal newsletter, Platform. The objective was to obtain more information about Transnet Freight Rail employees‘ thoughts on its effectiveness and the effectiveness of internal newsletters by using Platform as an example. The treatise explored the perceptions of employees and Transnet in terms of the effectiveness of the internal newsletter as a communication tool as well as their attitudes towards the newsletter as an information disseminating medium. A mixed methods approach was used for analysis in this study. The first methodological paradigm took an interpretivist approach, focusing primarily on analysing the content of the newsletter. The second methodological design was based on the positivistic theory approach and utilised a survey by questionnaire. One hundred and twenty (120) questionnaires were issued to Transnet Freight Rail employees representing the three regions: Central Region, Eastern Region & Western Region and the Head Office of which 120 (100 percent) were received back by the deadline. Of these respondents 56 (46,66 percent) said that they find Platform very relevant as an internal newsletter. A further finding was that 68,33 percent of the respondents said Platform should stay as it is. About 58,33 percent of the respondents took 30 minutes to an hour to read the newsletter with ratings of 72,5 percent interested in communication from management, 65 percent in financial performance, 60 percent in news about people and 59,16 percent in departmental information. The main types of information required are about updates on business performance and safety news. The content of six editions of the newsletter was analysed. The newsletter editions used were from the latest one published counting backwards. The content of the newsletter varies in each edition and depends on the theme. There are similar themes that come up with every edition such as safety. The style of writing used is simple to ensure maximum understanding.
- Full Text:
- Date Issued: 2012
- Authors: Matshoba, Thembekile Phillinah
- Date: 2012
- Subjects: Newsletters , Business communication
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8420 , http://hdl.handle.net/10948/d1015672
- Description: The research is based on a case study of an internal newsletter, Platform. The objective was to obtain more information about Transnet Freight Rail employees‘ thoughts on its effectiveness and the effectiveness of internal newsletters by using Platform as an example. The treatise explored the perceptions of employees and Transnet in terms of the effectiveness of the internal newsletter as a communication tool as well as their attitudes towards the newsletter as an information disseminating medium. A mixed methods approach was used for analysis in this study. The first methodological paradigm took an interpretivist approach, focusing primarily on analysing the content of the newsletter. The second methodological design was based on the positivistic theory approach and utilised a survey by questionnaire. One hundred and twenty (120) questionnaires were issued to Transnet Freight Rail employees representing the three regions: Central Region, Eastern Region & Western Region and the Head Office of which 120 (100 percent) were received back by the deadline. Of these respondents 56 (46,66 percent) said that they find Platform very relevant as an internal newsletter. A further finding was that 68,33 percent of the respondents said Platform should stay as it is. About 58,33 percent of the respondents took 30 minutes to an hour to read the newsletter with ratings of 72,5 percent interested in communication from management, 65 percent in financial performance, 60 percent in news about people and 59,16 percent in departmental information. The main types of information required are about updates on business performance and safety news. The content of six editions of the newsletter was analysed. The newsletter editions used were from the latest one published counting backwards. The content of the newsletter varies in each edition and depends on the theme. There are similar themes that come up with every edition such as safety. The style of writing used is simple to ensure maximum understanding.
- Full Text:
- Date Issued: 2012
Foraging ecology of Cape Gannets (Morus Capensis) at Bird Island, Algoa Bay
- Authors: Green, David Bruce
- Date: 2013
- Subjects: Birds of prey -- Behavior -- South Africa -- Algoa Bay , Gannets -- South Africa -- Algoa Bay , Birds -- Breeding -- South Africa -- Algoa Bay
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10725 , http://hdl.handle.net/10948/d1020790
- Description: The Cape gannet has undergone considerable population change and redistribution over the past 50 years. This has been linked to shifts in the abundance and distribution of their dominant prey, sardine and anchovy. Five breeding colonies, along the west coast of Southern Africa, have shown rapid population declines as a result of reduced prey availability. In contrast, a single colony (Bird Island, Algoa Bay) on the south coast of South Africa has, over the same period, grown fivefold and now supports approximately two thirds of the total population. Due to its conservation importance, and isolation from other breeding localities, it is important to assess the health of the Bird Island colony, and determine how foraging distribution relates to the environment to evaluate current measures of protection. This was achieved through two related studies; a long-term dietary analysis spanning 34 years, and a spatial foraging study, which related three years of tracking data to estimates of prey availability, oceanographic features and marine protected areas (MPAs). The results of the dietary study showed that the dietary constituents of Cape gannets breeding at Bird Island have remained similar over the last three decades, but the importance of sardine and anchovy has increased significantly. For sardine, in particular, this reflects an increased availability of this species (as deduced from hydroacoustic surveys) within the foraging range of the Bird Island colony. The dietary abundance of anchovy was found to be negatively correlated with that of sardine. Surprisingly,.the dietary abundance of anchovy was also negatively correlated with estimates of its availability based on acoustic surveys. The latter is likely to be due to sardine being a preferred prey item. Recent decreases in the dietary contribution of sardine (since 2005) suggest that this species is becoming less available to gannets, with profound implications in terms of nutrient gain associated with foraging. However, this has been mediated by an increase in the dietary contribution of anchovy, which now accounts for the vast majority of prey taken. Spatially, the foraging range of the Bird Island colony expanded during the three years of study, indicating an increase in effort. This increase was likely in an effort to track a distributional change of sardine and anchovy, which showed an apparent westward shift during the study period. There was, however, no evidence of birds tracking features associated with high productivity. This may have been partly due to anomalously warm conditions during the summer of 2012/2013, in which an absence of coastal upwelling prevented surface cooling. Nonetheless, low sea surface temperatures and high chlorophyll a concentrations do not seem to be reliable indicators of important Cape gannet foragingareas. Foraging effort was largely concentrated outside of MPAs, indicating that the current MPA network provides little protection for foraging gannets. This could change with the additional protection of the proposed Greater Addo Elephant National Park MPA expansion, as prey species are allowed to recover following the removal of fishing pressure. Overall, the colony appears to be in good condition as the diet is still dominated by live prey items, and the foraging range remains smaller than many of the colonies along the west coast. However, it is important that monitoring be continued, in particular with respect to changes in the availability of sardine and anchovy. Long-term shifts of these species out of the colony‘s foraging range could negatively influence the population in the future. This might be worsened by interspecific competition for prey resources. Considering the conservation importance of this population, maintenance of healthy prey stocks within the home range of breeding Cape gannets should be prioritised in order to prevent declines similar to those observed at west coast colonies.
- Full Text:
- Date Issued: 2013
- Authors: Green, David Bruce
- Date: 2013
- Subjects: Birds of prey -- Behavior -- South Africa -- Algoa Bay , Gannets -- South Africa -- Algoa Bay , Birds -- Breeding -- South Africa -- Algoa Bay
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10725 , http://hdl.handle.net/10948/d1020790
- Description: The Cape gannet has undergone considerable population change and redistribution over the past 50 years. This has been linked to shifts in the abundance and distribution of their dominant prey, sardine and anchovy. Five breeding colonies, along the west coast of Southern Africa, have shown rapid population declines as a result of reduced prey availability. In contrast, a single colony (Bird Island, Algoa Bay) on the south coast of South Africa has, over the same period, grown fivefold and now supports approximately two thirds of the total population. Due to its conservation importance, and isolation from other breeding localities, it is important to assess the health of the Bird Island colony, and determine how foraging distribution relates to the environment to evaluate current measures of protection. This was achieved through two related studies; a long-term dietary analysis spanning 34 years, and a spatial foraging study, which related three years of tracking data to estimates of prey availability, oceanographic features and marine protected areas (MPAs). The results of the dietary study showed that the dietary constituents of Cape gannets breeding at Bird Island have remained similar over the last three decades, but the importance of sardine and anchovy has increased significantly. For sardine, in particular, this reflects an increased availability of this species (as deduced from hydroacoustic surveys) within the foraging range of the Bird Island colony. The dietary abundance of anchovy was found to be negatively correlated with that of sardine. Surprisingly,.the dietary abundance of anchovy was also negatively correlated with estimates of its availability based on acoustic surveys. The latter is likely to be due to sardine being a preferred prey item. Recent decreases in the dietary contribution of sardine (since 2005) suggest that this species is becoming less available to gannets, with profound implications in terms of nutrient gain associated with foraging. However, this has been mediated by an increase in the dietary contribution of anchovy, which now accounts for the vast majority of prey taken. Spatially, the foraging range of the Bird Island colony expanded during the three years of study, indicating an increase in effort. This increase was likely in an effort to track a distributional change of sardine and anchovy, which showed an apparent westward shift during the study period. There was, however, no evidence of birds tracking features associated with high productivity. This may have been partly due to anomalously warm conditions during the summer of 2012/2013, in which an absence of coastal upwelling prevented surface cooling. Nonetheless, low sea surface temperatures and high chlorophyll a concentrations do not seem to be reliable indicators of important Cape gannet foragingareas. Foraging effort was largely concentrated outside of MPAs, indicating that the current MPA network provides little protection for foraging gannets. This could change with the additional protection of the proposed Greater Addo Elephant National Park MPA expansion, as prey species are allowed to recover following the removal of fishing pressure. Overall, the colony appears to be in good condition as the diet is still dominated by live prey items, and the foraging range remains smaller than many of the colonies along the west coast. However, it is important that monitoring be continued, in particular with respect to changes in the availability of sardine and anchovy. Long-term shifts of these species out of the colony‘s foraging range could negatively influence the population in the future. This might be worsened by interspecific competition for prey resources. Considering the conservation importance of this population, maintenance of healthy prey stocks within the home range of breeding Cape gannets should be prioritised in order to prevent declines similar to those observed at west coast colonies.
- Full Text:
- Date Issued: 2013
Hungry but silent: a content analysis of media reporting on the 2011-2012 famine in Somalia
- Authors: Stupart, Richard
- Date: 2013
- Subjects: Famines -- Political aspects -- Somalia Somalia -- In mass media Famines in mass media
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3500 , http://hdl.handle.net/10962/d1006054
- Description: This dissertation examines media coverage of the 2011- 2012 famine in Somalia by the websites of BBC News, CNN and Al Jazeera. Using both quantitative and qualitative content analyses, it asks why coverage of the famine began as late as it did, despite ample evidence of the coming famine. It further surveys the famine-related news reports for evidence of four paradigms through which the causes of famine can be understood; as a Malthusian competition between population and land, as a failure of food entitlements as conceived of by Sen (1981), as critical political event (Edkins, 2004), or as an issue of criminality (Alex de Waal, 2008). Findings include a dramatic silencing of victim’s accounts of famine, despite a reliance on their photographic images, as well as an overwhelming preference for Malthusian accounts of the famine. Late media coverage is explored via a new-values paradigm which links the sudden outburst of media coverage for the famine to a formal UN declaration, and suggests that this may have created a new elite-relevance to the event which did not exist before, and therefore making it of relevance to domestic publics.
- Full Text:
- Date Issued: 2013
- Authors: Stupart, Richard
- Date: 2013
- Subjects: Famines -- Political aspects -- Somalia Somalia -- In mass media Famines in mass media
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3500 , http://hdl.handle.net/10962/d1006054
- Description: This dissertation examines media coverage of the 2011- 2012 famine in Somalia by the websites of BBC News, CNN and Al Jazeera. Using both quantitative and qualitative content analyses, it asks why coverage of the famine began as late as it did, despite ample evidence of the coming famine. It further surveys the famine-related news reports for evidence of four paradigms through which the causes of famine can be understood; as a Malthusian competition between population and land, as a failure of food entitlements as conceived of by Sen (1981), as critical political event (Edkins, 2004), or as an issue of criminality (Alex de Waal, 2008). Findings include a dramatic silencing of victim’s accounts of famine, despite a reliance on their photographic images, as well as an overwhelming preference for Malthusian accounts of the famine. Late media coverage is explored via a new-values paradigm which links the sudden outburst of media coverage for the famine to a formal UN declaration, and suggests that this may have created a new elite-relevance to the event which did not exist before, and therefore making it of relevance to domestic publics.
- Full Text:
- Date Issued: 2013
Characterization of animal fibres
- Authors: Notayi, Mzwamadoda
- Date: 2014
- Subjects: Animal fibres , Textile fabrics , Animal science
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10552 , http://hdl.handle.net/10948/d1020426
- Description: Identification of fibres, particularly in blends, requires knowledge of their characteristics. Individual Identifying features between wool and mohair fibres were investigated in this study using a Scanning Electron Microscope (SEM), Fourier Transform Infrared-Attenuated Total Reflection (FTIR-ATR), Fourier Transform Raman and Atomic Force Microscope (AFM). This study confirmed that wool and mohair can be differentiated and identified in blends using the cuticle scale height (CSH) criterion, wool having an average CSH of 0.6 ± 0.1 μm and mohair having an average CSH of 0.4 ± 0.1 μm. The AFM provided highly reproducible CSH results, which also confirmed the SEM results that indeed wool and mohair could be differentiated using the CSH as criterion. The AFM gave a CSH value of 0.9 ± 0.2 μm for wool and 0.6 ± 0.2 μm for mohair, the difference between the two results being statistically significant according to the student t-test. It has been demonstrated that wool and mohair identification in blends is possible, by using the AFM to measure CSH, although the method is very time consuming and might be expensive. The FTIR-ATR showed similar spectra for wool and mohair fibres, confirming that the two fibre types consist of the same polymer material. Nevertheless, a difference was observed in the ratios of the relative intensities of the amide I (around 1630 cm-1) to the amide II (around 1515cm-1) absorption bands. The FT Raman provided similar spectra for the wool and mohair fibres, although a possible distinguishing feature between the two fibres could be the intensities of the alkyl side chains chemical band near 2940 cm-1 in the spectra of the two fibre types. According to the results obtained in this study, the FTIR-ATR and the FT Raman techniques may have potential for differentiating between wool and mohair but this requires further investigation.
- Full Text:
- Date Issued: 2014
- Authors: Notayi, Mzwamadoda
- Date: 2014
- Subjects: Animal fibres , Textile fabrics , Animal science
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10552 , http://hdl.handle.net/10948/d1020426
- Description: Identification of fibres, particularly in blends, requires knowledge of their characteristics. Individual Identifying features between wool and mohair fibres were investigated in this study using a Scanning Electron Microscope (SEM), Fourier Transform Infrared-Attenuated Total Reflection (FTIR-ATR), Fourier Transform Raman and Atomic Force Microscope (AFM). This study confirmed that wool and mohair can be differentiated and identified in blends using the cuticle scale height (CSH) criterion, wool having an average CSH of 0.6 ± 0.1 μm and mohair having an average CSH of 0.4 ± 0.1 μm. The AFM provided highly reproducible CSH results, which also confirmed the SEM results that indeed wool and mohair could be differentiated using the CSH as criterion. The AFM gave a CSH value of 0.9 ± 0.2 μm for wool and 0.6 ± 0.2 μm for mohair, the difference between the two results being statistically significant according to the student t-test. It has been demonstrated that wool and mohair identification in blends is possible, by using the AFM to measure CSH, although the method is very time consuming and might be expensive. The FTIR-ATR showed similar spectra for wool and mohair fibres, confirming that the two fibre types consist of the same polymer material. Nevertheless, a difference was observed in the ratios of the relative intensities of the amide I (around 1630 cm-1) to the amide II (around 1515cm-1) absorption bands. The FT Raman provided similar spectra for the wool and mohair fibres, although a possible distinguishing feature between the two fibres could be the intensities of the alkyl side chains chemical band near 2940 cm-1 in the spectra of the two fibre types. According to the results obtained in this study, the FTIR-ATR and the FT Raman techniques may have potential for differentiating between wool and mohair but this requires further investigation.
- Full Text:
- Date Issued: 2014
Electrical conductivity experiments on carbon-rich Karoo shales and forward modelling of aeromagnetic data across the Beattie Anomaly
- Authors: Branch, Thomas Cameron
- Date: 2014
- Subjects: Earth sciences -- South Africa -- Karoo , Geology -- South Africa -- Karoo
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10662 , http://hdl.handle.net/10948/d1014544
- Description: The Beattie Magnetic Anomaly is the world’s longest terrestrial magnetic anomaly with a strike length of over 1000 km and a wavelength in excess of 100 km. Collinear with this is a large belt of elevated crustal conductivities called the Southern Cape Conductive Belt. Historical crustal interpretations proposed a common source of serpentinized ophiolite as an explanation for both the anomalous crustal magnetic susceptibility and electrical conductivities. Spreading between the Western and Eastern Cape of South Africa the mid- to lower crust that hosts these anomalies is obscured by the overlying Cape and Karoo Supergroups. Between 2003 and 2006, three high resolution geophysical experiments were completed across the surface maximum of the Beattie Magnetic Anomaly (BMA) and the Southern Cape Conductive Belt (SCCB). These included a magnetotelluric (MT) survey and near vertical reflection and wide angle refraction seismic profiles. Within the MT inversion model the SCCB appeared as a composite anomaly, which included a mid-crustal conductor which is spatially associated with the BMA and a laterally continuous upper crustal conductor which is located at depths equivalent to the lower Karoo Supergroup. Subsequently; the upper crustal conductor was identified in northern and eastern extensions of the magnetotelluric profile; a distance in excess of 400 km. Historical magnetometer and Schlumberger Sounding experiments have previously identified elevated conductivities in the Karoo sequences which were attributed to the Whitehill and Prince Albert formations. These carboniferous, transgressive sediments are known to be conductive from borehole conductivity surveys and direct measurements at surface. In order to constrain the conductive properties of these sediments, impedance spectroscopy (IS) experiments were completed on core samples collected from a historical borehole drilled near to the MT profile. Part One of this thesis presents the results of these experiments, which support the proposition that the Whitehill and Prince Albert Formations are responsible for the laterally continuous, sub-horizontal, upper crustal conductor visible in the MT inversion model. Vitrinite reflectance studies were performed on the same samples by the Montanuniversität, in Leoben, these results corroborate the proposition that elevated organic carbon, of meta-anthracite rank, is the primary conductive phase for the Whitehill and Prince Albert formations. Part two of this thesis completed forward modelling exercises using historical aeromagnetic data previously collected across the Beattie Magnetic Anomaly. Preliminary models were unable to fit the geometry of any single magnetic model with conductors present in the MT inversion model discounting the proposition that the SCCB and BMA arise from a single crustal unit. Two constrained models were arrived at through an iterative process that sought a best fit between the measured data and the NVR crustal interpretations. The first model, proposes a largely resistive unit which incorporates portions of elevated crustal conductivity; these conductors are spatially correlated to crustal portions also characterised by high seismic reflectivity. The size of this modelled body suggest the likely host of the BMA is an intermediate plutonic terrane, analogous with the Natal sector of the Namaqua Natal Mobile Belt as well as the Heimefrontfjella in Dronning Maud Land, Antarctica, with magnetite hosted within shear zones. This is in agreement with previous studies. The second model proposes a lower crustal sliver imaged in the NVR data at depths proximal to the Curie Isotherm for magnetite and hematite as the source of the BMA. At these depths geomagnetic properties such as burial magnetisation or thermo-viscous remanent magnetism (TVRM) can potentially be linked to regional scale tectonic processes and can theoretically elevate a body’s net magnetic susceptibility. TVRM has been proposed for long wavelength crustal anomalies elsewhere.
- Full Text:
- Date Issued: 2014
- Authors: Branch, Thomas Cameron
- Date: 2014
- Subjects: Earth sciences -- South Africa -- Karoo , Geology -- South Africa -- Karoo
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10662 , http://hdl.handle.net/10948/d1014544
- Description: The Beattie Magnetic Anomaly is the world’s longest terrestrial magnetic anomaly with a strike length of over 1000 km and a wavelength in excess of 100 km. Collinear with this is a large belt of elevated crustal conductivities called the Southern Cape Conductive Belt. Historical crustal interpretations proposed a common source of serpentinized ophiolite as an explanation for both the anomalous crustal magnetic susceptibility and electrical conductivities. Spreading between the Western and Eastern Cape of South Africa the mid- to lower crust that hosts these anomalies is obscured by the overlying Cape and Karoo Supergroups. Between 2003 and 2006, three high resolution geophysical experiments were completed across the surface maximum of the Beattie Magnetic Anomaly (BMA) and the Southern Cape Conductive Belt (SCCB). These included a magnetotelluric (MT) survey and near vertical reflection and wide angle refraction seismic profiles. Within the MT inversion model the SCCB appeared as a composite anomaly, which included a mid-crustal conductor which is spatially associated with the BMA and a laterally continuous upper crustal conductor which is located at depths equivalent to the lower Karoo Supergroup. Subsequently; the upper crustal conductor was identified in northern and eastern extensions of the magnetotelluric profile; a distance in excess of 400 km. Historical magnetometer and Schlumberger Sounding experiments have previously identified elevated conductivities in the Karoo sequences which were attributed to the Whitehill and Prince Albert formations. These carboniferous, transgressive sediments are known to be conductive from borehole conductivity surveys and direct measurements at surface. In order to constrain the conductive properties of these sediments, impedance spectroscopy (IS) experiments were completed on core samples collected from a historical borehole drilled near to the MT profile. Part One of this thesis presents the results of these experiments, which support the proposition that the Whitehill and Prince Albert Formations are responsible for the laterally continuous, sub-horizontal, upper crustal conductor visible in the MT inversion model. Vitrinite reflectance studies were performed on the same samples by the Montanuniversität, in Leoben, these results corroborate the proposition that elevated organic carbon, of meta-anthracite rank, is the primary conductive phase for the Whitehill and Prince Albert formations. Part two of this thesis completed forward modelling exercises using historical aeromagnetic data previously collected across the Beattie Magnetic Anomaly. Preliminary models were unable to fit the geometry of any single magnetic model with conductors present in the MT inversion model discounting the proposition that the SCCB and BMA arise from a single crustal unit. Two constrained models were arrived at through an iterative process that sought a best fit between the measured data and the NVR crustal interpretations. The first model, proposes a largely resistive unit which incorporates portions of elevated crustal conductivity; these conductors are spatially correlated to crustal portions also characterised by high seismic reflectivity. The size of this modelled body suggest the likely host of the BMA is an intermediate plutonic terrane, analogous with the Natal sector of the Namaqua Natal Mobile Belt as well as the Heimefrontfjella in Dronning Maud Land, Antarctica, with magnetite hosted within shear zones. This is in agreement with previous studies. The second model proposes a lower crustal sliver imaged in the NVR data at depths proximal to the Curie Isotherm for magnetite and hematite as the source of the BMA. At these depths geomagnetic properties such as burial magnetisation or thermo-viscous remanent magnetism (TVRM) can potentially be linked to regional scale tectonic processes and can theoretically elevate a body’s net magnetic susceptibility. TVRM has been proposed for long wavelength crustal anomalies elsewhere.
- Full Text:
- Date Issued: 2014
Modelling the spatial and genetic response of the endemic sparid: Polysteganus praeorbitalis (Pisces: Sparidae) to climate change in the Agulhas Current system
- Authors: Isemonger, Devin Neil
- Date: 2014
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/54509 , vital:26576
- Description: The Scotsman Seabream, Polysteganus praeorbitalis, is one of several large, slow-growing members of the Sparidae family of fishes endemic to the Agulhas Current system in the Western Indian Ocean (WIO). Relatively little research has been conducted on this species despite its importance to both recreational and commercial line fisheries in South Africa and the drastic decline in catch per unit effort (CPUE) that has been recorded since the 1940s. Changing sea temperatures as a result of global climate change are further expected to affect the distribution and abundance of many fish species based on their thermal tolerances, life histories and population structures. The ability of these species to shift their distribution and adapt to new environments and thermal conditions will depend to some degree on the levels of genetic variation and gene flow, within and between populations. A combined approach using species distribution modelling and genetic analyses may prove to be a useful tool in investigating the potential effects of climate change on the distribution and genetic diversity of species. An ensemble species distribution model (SDM) based on 205 occurrence records and 30 years of Reynolds Optimum Interpolated (OI) sea surface temperature data was constructed to predict the distributional response of P. praeorbitalis to climate change in the Agulhas Current system. The ensemble SDM displayed a true skill statistic (TSS) of 0.975 and an area under the receiver operating curve (ROC) of 0.999, indicating good model fit. Autumn and winter minimum temperatures, as well as bathymetry, were the most important predictor variables in the majority of models, indicating that these variables may directly constrain the distribution of P. praeorbitalis. In particular, the southern range edge of this species appeared to be constrained by autumn and winter minima, with high model agreement on this range edge. Conversely, the northern range limit showed poor model agreement leading to a gradual reduction in occurrence. This indicates that this range edge may be constrained by other factors not included in the models such as species interactions. The ensemble SDM projected the current range of P. praeorbitalis to be 1500 km², smaller than the published range for this species. The model underestimated the northern range edge of this species by approximately 5° latitude when binary transformed. This is probably due to the rarity of this species in the landings of the Mozambican linefishery, which was assumed to be an indication of low abundance of P. praeorbitalis in these waters. The absence of a specimen to verify the published northern range edge of this species indicates that the northern range edge produced by this model is likely to be closer to the actual range limit of the species. A range contraction of 30% occurring at both the northern and southern edge of P. praeorbitalis’ range and range fragmentation occurring, towards its northern range edge by 2030, was predicted. These changes are modelled to be the results of cooling related to the intensification of the Port Alfred upwelling cell and of warming predicted north of the Natal Bight and in southern Mozambique. Genetic analyses of the nuclear DNA (nDNA) S7 intron 1 and mitochondrial DNA (mtDNA) control region genes were carried out using 118 tissue samples of P. praeorbitalis collected at four main localities: the Eastern Cape, Transkei, southern KwaZulu-Natal and northern KwaZulu-Natal. Analyses of genetic diversity levels revealed relatively low diversity in the mtDNA dataset (Hd = 0.488; π = 0.004) and moderate levels of diversity in the nDNA dataset (Ad = 0.922; π = 0.005). The low levels of diversity observed in the mtDNA dataset might be explained by a number of factors, including high variation in spawning success, the negative effects of over-harvesting, or a recent population bottleneck. The last explanation is supported by characteristic star-shaped haplotype networks and unimodal mismatch distributions displayed by both datasets. These results, in conjunction with a significant (p = 0.005) negative Tajimas D value (-2.029) in the mtDNA dataset and significant (p = 0.0005) negative Fu’s F statistic in both the nDNA (F = -26.5) and mtDNA (F = -11.9) datasets, provide strong evidence for a recent population expansion after a bottleneck event in this species. Spatially, mtDNA diversity was highest in the Eastern Cape and lowest in the middle localities, while nDNA diversity showed the opposite pattern. These results may be indicative of differences in the sex ratio between localities, possibly as a result of the protogynous hermaphroditism that has been postulated for this species. Although pairwise comparisons and exact tests of population differentiation revealed no significant geneticdifferentiation between populations in the mtDNA dataset, there was some evidence of low levels of differentiation in the nDNA dataset. This occurred for comparisons between the Eastern Cape and Transkei (Fst = 0.039; p <0.05), and the northern KwaZulu-Natal (Fst = 0.045; p < 0.05).. This might be the result of one or a combination of factors including the effects of the Port Alfred upwelling cell on dispersal and gene flow, or the possibility of more than one spawning ground for this species promoting sub-structuring. A SAMOVA analyses run on the nDNA dataset maximised variance by grouping the Eastern Cape and southern KwaZulu-Natal together and Transkei and northern KwaZulu-Natal together in two groups. This revealed no evidence of spatial structure (p = 0.36), with only 3.30% of variation explained by this grouping. The removal of individuals below the estimated length at 50% maturity in the nDNA dataset, in order to test for temporal structure, resulted in stronger evidence of differentiation between the Eastern Cape and all other localities: Transkei (Fst = 0.081; p< 0.05), southern KwaZulu-Natal (Fst = 0.031; p<0.05), and northern KwaZulu-Natal (Fst = 0.078; p< 0.05). This indicates that some temporal genetic structure may exist between age classes within this species. The differentiation observed between the Eastern Cape and other localities, coupled with the high percentage of private haplotypes in the mtDNA dataset in this locality, indicates that this area is where P. praeorbitalis is most vulnerable to the potential negative effects of climate change on its genetic diversity. However, the vast majority of this species genetic diversity appears to reside towards the centre of its range where it is most abundant and the lack of strong genetic structure indicates high levels of gene flow. In conclusion, while P. praeorbitalis is vulnerable to range loss as a result of climate change, its genetic diversity is unlikely to be greatly affected.
- Full Text:
- Date Issued: 2014
- Authors: Isemonger, Devin Neil
- Date: 2014
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/54509 , vital:26576
- Description: The Scotsman Seabream, Polysteganus praeorbitalis, is one of several large, slow-growing members of the Sparidae family of fishes endemic to the Agulhas Current system in the Western Indian Ocean (WIO). Relatively little research has been conducted on this species despite its importance to both recreational and commercial line fisheries in South Africa and the drastic decline in catch per unit effort (CPUE) that has been recorded since the 1940s. Changing sea temperatures as a result of global climate change are further expected to affect the distribution and abundance of many fish species based on their thermal tolerances, life histories and population structures. The ability of these species to shift their distribution and adapt to new environments and thermal conditions will depend to some degree on the levels of genetic variation and gene flow, within and between populations. A combined approach using species distribution modelling and genetic analyses may prove to be a useful tool in investigating the potential effects of climate change on the distribution and genetic diversity of species. An ensemble species distribution model (SDM) based on 205 occurrence records and 30 years of Reynolds Optimum Interpolated (OI) sea surface temperature data was constructed to predict the distributional response of P. praeorbitalis to climate change in the Agulhas Current system. The ensemble SDM displayed a true skill statistic (TSS) of 0.975 and an area under the receiver operating curve (ROC) of 0.999, indicating good model fit. Autumn and winter minimum temperatures, as well as bathymetry, were the most important predictor variables in the majority of models, indicating that these variables may directly constrain the distribution of P. praeorbitalis. In particular, the southern range edge of this species appeared to be constrained by autumn and winter minima, with high model agreement on this range edge. Conversely, the northern range limit showed poor model agreement leading to a gradual reduction in occurrence. This indicates that this range edge may be constrained by other factors not included in the models such as species interactions. The ensemble SDM projected the current range of P. praeorbitalis to be 1500 km², smaller than the published range for this species. The model underestimated the northern range edge of this species by approximately 5° latitude when binary transformed. This is probably due to the rarity of this species in the landings of the Mozambican linefishery, which was assumed to be an indication of low abundance of P. praeorbitalis in these waters. The absence of a specimen to verify the published northern range edge of this species indicates that the northern range edge produced by this model is likely to be closer to the actual range limit of the species. A range contraction of 30% occurring at both the northern and southern edge of P. praeorbitalis’ range and range fragmentation occurring, towards its northern range edge by 2030, was predicted. These changes are modelled to be the results of cooling related to the intensification of the Port Alfred upwelling cell and of warming predicted north of the Natal Bight and in southern Mozambique. Genetic analyses of the nuclear DNA (nDNA) S7 intron 1 and mitochondrial DNA (mtDNA) control region genes were carried out using 118 tissue samples of P. praeorbitalis collected at four main localities: the Eastern Cape, Transkei, southern KwaZulu-Natal and northern KwaZulu-Natal. Analyses of genetic diversity levels revealed relatively low diversity in the mtDNA dataset (Hd = 0.488; π = 0.004) and moderate levels of diversity in the nDNA dataset (Ad = 0.922; π = 0.005). The low levels of diversity observed in the mtDNA dataset might be explained by a number of factors, including high variation in spawning success, the negative effects of over-harvesting, or a recent population bottleneck. The last explanation is supported by characteristic star-shaped haplotype networks and unimodal mismatch distributions displayed by both datasets. These results, in conjunction with a significant (p = 0.005) negative Tajimas D value (-2.029) in the mtDNA dataset and significant (p = 0.0005) negative Fu’s F statistic in both the nDNA (F = -26.5) and mtDNA (F = -11.9) datasets, provide strong evidence for a recent population expansion after a bottleneck event in this species. Spatially, mtDNA diversity was highest in the Eastern Cape and lowest in the middle localities, while nDNA diversity showed the opposite pattern. These results may be indicative of differences in the sex ratio between localities, possibly as a result of the protogynous hermaphroditism that has been postulated for this species. Although pairwise comparisons and exact tests of population differentiation revealed no significant geneticdifferentiation between populations in the mtDNA dataset, there was some evidence of low levels of differentiation in the nDNA dataset. This occurred for comparisons between the Eastern Cape and Transkei (Fst = 0.039; p <0.05), and the northern KwaZulu-Natal (Fst = 0.045; p < 0.05).. This might be the result of one or a combination of factors including the effects of the Port Alfred upwelling cell on dispersal and gene flow, or the possibility of more than one spawning ground for this species promoting sub-structuring. A SAMOVA analyses run on the nDNA dataset maximised variance by grouping the Eastern Cape and southern KwaZulu-Natal together and Transkei and northern KwaZulu-Natal together in two groups. This revealed no evidence of spatial structure (p = 0.36), with only 3.30% of variation explained by this grouping. The removal of individuals below the estimated length at 50% maturity in the nDNA dataset, in order to test for temporal structure, resulted in stronger evidence of differentiation between the Eastern Cape and all other localities: Transkei (Fst = 0.081; p< 0.05), southern KwaZulu-Natal (Fst = 0.031; p<0.05), and northern KwaZulu-Natal (Fst = 0.078; p< 0.05). This indicates that some temporal genetic structure may exist between age classes within this species. The differentiation observed between the Eastern Cape and other localities, coupled with the high percentage of private haplotypes in the mtDNA dataset in this locality, indicates that this area is where P. praeorbitalis is most vulnerable to the potential negative effects of climate change on its genetic diversity. However, the vast majority of this species genetic diversity appears to reside towards the centre of its range where it is most abundant and the lack of strong genetic structure indicates high levels of gene flow. In conclusion, while P. praeorbitalis is vulnerable to range loss as a result of climate change, its genetic diversity is unlikely to be greatly affected.
- Full Text:
- Date Issued: 2014
Rehab is for quitters
- Authors: Maharaj, Keshav
- Date: 2014
- Subjects: Creative writing (Higher education) Short stories, South African (English) -- 21st century South African fiction (English) -- 21st century English language -- Writing
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:5972 , http://hdl.handle.net/10962/d1011901
- Description: My collection has the common theme of addiction: addictive personalities strung across the pages. Not only the usual addictions such as the daily-ritualized beer or joint, but also the pain of addiction to anti-social habits, pathologies, forbidden love, etc. I try to capture the behavior and life that surrounds addictions too: relationships, rehab, criminal behavior, all sorts of abuse, etc. Some of the stories are heavy-handed, slapping the reader in the face, some are subtler. Some are told with lightness and humor, some with gravity.
- Full Text:
- Date Issued: 2014
- Authors: Maharaj, Keshav
- Date: 2014
- Subjects: Creative writing (Higher education) Short stories, South African (English) -- 21st century South African fiction (English) -- 21st century English language -- Writing
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:5972 , http://hdl.handle.net/10962/d1011901
- Description: My collection has the common theme of addiction: addictive personalities strung across the pages. Not only the usual addictions such as the daily-ritualized beer or joint, but also the pain of addiction to anti-social habits, pathologies, forbidden love, etc. I try to capture the behavior and life that surrounds addictions too: relationships, rehab, criminal behavior, all sorts of abuse, etc. Some of the stories are heavy-handed, slapping the reader in the face, some are subtler. Some are told with lightness and humor, some with gravity.
- Full Text:
- Date Issued: 2014