An investigation of reactions directed towards the synthesis of 2-methyl-2-(methylthio)propanal oxime
- Authors: Whittaker, Ruth Eleanor
- Date: 1995
- Subjects: Pesticides -- Synthesis , Insecticides , Aldicarb -- Synthesis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4322 , http://hdl.handle.net/10962/d1004980 , Pesticides -- Synthesis , Insecticides , Aldicarb -- Synthesis
- Description: The processes leading to the formation of 2-methyl-2-(methylthio)propanal oxime, known industrially as aldicarb oxime, have been studied. The three stages of the synthesis, viz., chlorination, thiomethylation and oximation have been thoroughly investigated, with the aim of optimising the yield and purity of aldicarb oxime. Attention has been focused on the chlorination step, and the effects of altering various conditions have been determined; the reaction has been carried out in the absence and presence of heat, solvent and buffer, and the extent of chlorine addition has also been varied. These studies have led to some improvement in the yield for this step. Several simple and inexpensive methods for purifying contaminated batches of aldicarb oxime have also been examined. Possible aldicarb oxime contaminants, identified by GLC and GC-MS analysis, have been synthesised for use as chromatographic and spectroscopic standards, and confirmation of the presence of a number of these contaminants has been achieved. Aldehyde trimers have been found to be the primary contaminants present in aldicarb oxime and the thermal stability of these trimers, their corresponding monomers and aldicarb oxime itself has been studied using variable temperature ¹H NMR spectroscopy. Novel pyridine derivatives, with potential as aldicarb analogues, have been synthesised and characterised using spectroscopic methods.
- Full Text:
- Authors: Whittaker, Ruth Eleanor
- Date: 1995
- Subjects: Pesticides -- Synthesis , Insecticides , Aldicarb -- Synthesis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4322 , http://hdl.handle.net/10962/d1004980 , Pesticides -- Synthesis , Insecticides , Aldicarb -- Synthesis
- Description: The processes leading to the formation of 2-methyl-2-(methylthio)propanal oxime, known industrially as aldicarb oxime, have been studied. The three stages of the synthesis, viz., chlorination, thiomethylation and oximation have been thoroughly investigated, with the aim of optimising the yield and purity of aldicarb oxime. Attention has been focused on the chlorination step, and the effects of altering various conditions have been determined; the reaction has been carried out in the absence and presence of heat, solvent and buffer, and the extent of chlorine addition has also been varied. These studies have led to some improvement in the yield for this step. Several simple and inexpensive methods for purifying contaminated batches of aldicarb oxime have also been examined. Possible aldicarb oxime contaminants, identified by GLC and GC-MS analysis, have been synthesised for use as chromatographic and spectroscopic standards, and confirmation of the presence of a number of these contaminants has been achieved. Aldehyde trimers have been found to be the primary contaminants present in aldicarb oxime and the thermal stability of these trimers, their corresponding monomers and aldicarb oxime itself has been studied using variable temperature ¹H NMR spectroscopy. Novel pyridine derivatives, with potential as aldicarb analogues, have been synthesised and characterised using spectroscopic methods.
- Full Text:
Critical success factors in implementing projects on restituted land parcels in South Africa
- Authors: Whiting, Christoper Whiting
- Date: 2020
- Subjects: Community development -- Management -- South Africa , Community development -- Management -- South Africa -- Case studies , Economic development projects -- Management -- South Africa , Economic development projects -- Management -- South Africa -- Case studies , Land reform -- South Africa -- Economic aspects , Land reform beneficiaries -- South Africa -- Case studies , Restitution -- South Africa -- Case studies
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/167697 , vital:41504
- Description: Currently there is a perception in South Africa that projects undertaken on parcels of restituted land are experiencing a much higher failure than success rate. There are, however, a few projects that are reaping the rewards and uplifting their communities, as intended by the land redistribution program. One community in particular, located in Mpumalanga, called community A, is presently undertaking a development project. This development project is one of the most successful restituted land parcel projects ever in South Africa. The purpose of the study is to determine the critical success factors in this community development project that have allowed it to enjoy such high levels of success. Are these critical success factors different from the generic industry critical success factors and, if so, what are they? As informed through literature, the critical success factors focused on in this study are as follows: the influence of management, project communication, knowledge management, the role of senior management, business strategy, project success measurements, and training and development. For the empirical study, a physical questionnaire was handed to 35 management members currently employed in the community development project. The questionnaire requested the demographics of all participants and asked them to rate, using a five-point Likert scale, their perceptions of the present project activities and of the importance of the project activities mentioned in making the project successful. Participants had to indicate the extent to which they agreed with each statement in the questionnaire. The responses obtained from the survey were presented and analysed. The study found that the critical success factor “role of senior management” was the largest problem area in the restituted land development project. “Training and development opportunities” came in second, with both factor areas showing large variances. Recommendations have been given on how to address both these problematic areas in the development project and how future restituted land parcel projects can better utilize these factors to ensure successful project implementation and long-term project success.
- Full Text:
- Authors: Whiting, Christoper Whiting
- Date: 2020
- Subjects: Community development -- Management -- South Africa , Community development -- Management -- South Africa -- Case studies , Economic development projects -- Management -- South Africa , Economic development projects -- Management -- South Africa -- Case studies , Land reform -- South Africa -- Economic aspects , Land reform beneficiaries -- South Africa -- Case studies , Restitution -- South Africa -- Case studies
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/167697 , vital:41504
- Description: Currently there is a perception in South Africa that projects undertaken on parcels of restituted land are experiencing a much higher failure than success rate. There are, however, a few projects that are reaping the rewards and uplifting their communities, as intended by the land redistribution program. One community in particular, located in Mpumalanga, called community A, is presently undertaking a development project. This development project is one of the most successful restituted land parcel projects ever in South Africa. The purpose of the study is to determine the critical success factors in this community development project that have allowed it to enjoy such high levels of success. Are these critical success factors different from the generic industry critical success factors and, if so, what are they? As informed through literature, the critical success factors focused on in this study are as follows: the influence of management, project communication, knowledge management, the role of senior management, business strategy, project success measurements, and training and development. For the empirical study, a physical questionnaire was handed to 35 management members currently employed in the community development project. The questionnaire requested the demographics of all participants and asked them to rate, using a five-point Likert scale, their perceptions of the present project activities and of the importance of the project activities mentioned in making the project successful. Participants had to indicate the extent to which they agreed with each statement in the questionnaire. The responses obtained from the survey were presented and analysed. The study found that the critical success factor “role of senior management” was the largest problem area in the restituted land development project. “Training and development opportunities” came in second, with both factor areas showing large variances. Recommendations have been given on how to address both these problematic areas in the development project and how future restituted land parcel projects can better utilize these factors to ensure successful project implementation and long-term project success.
- Full Text:
The genesis and controls of gold mineralization south of Rehoboth, Namibia
- Authors: Whitfield, Derek
- Date: 1991
- Subjects: Gold ores -- Geology -- Namibia , Gold ores -- Geology -- Africa, Southern
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4948 , http://hdl.handle.net/10962/d1005560 , Gold ores -- Geology -- Namibia , Gold ores -- Geology -- Africa, Southern
- Description: Gold mineralization is hosted within gossanous quartz-haematite veins in volcano-sedimentary lithologies of the Klein Aub - Rehoboth basin of the Irumide Belt, Namibia. Mineralization and hydrothermal alteration are restricted to deformed lithologies particularly the metasediments. Lithological relationships, geochemistry and metallogenic characteristics of the Irumide Belt suggest an intra-continental rift setting. Copper mineralization is well known along the length of the belt, from Klein Aub in the southwest to Ghanzi in the northeast, whereas gold mineralization appears restricted to the Klein Aub Rehoboth basin. The gold is envisaged as having being leached initially from graben fill sequences during rift closure and basin dewatering. Location of the mineralization is strongly controlled by structure and lithological contact zones. Such zones are percieved as having acted as conduit zones for escaping mineralized fluids during basin closure and deformation. Apart from the lack of an effective mineralizing trap, all features consistent with the development of an ore deposit are present. The largest mineralization traps within the area studied are shear zones followed by lithological contact zones. The Mebi and Blanks gold mines are developed over large shear zones while the Swartmodder and Neuras gold mines are situated over mineralized lithological contacts. The Swartmodder copper mine yielded ore from a mineralized schist enclave within granite. Copper and gold occurrences are attributed to two contrasting styles of mineralization. Copper mineralization is suggested to have developed during initial rifting of the belt (ie. stratabound sedimentary exhalative type), while the gold and minor copper resulted from rift closure and basin dewatering. Although no economical orebody was realized during the course of this study a model is proposed for the development of mineralization within the Irumide basement lithologies as a working hypothesis for future exploration.
- Full Text:
- Authors: Whitfield, Derek
- Date: 1991
- Subjects: Gold ores -- Geology -- Namibia , Gold ores -- Geology -- Africa, Southern
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4948 , http://hdl.handle.net/10962/d1005560 , Gold ores -- Geology -- Namibia , Gold ores -- Geology -- Africa, Southern
- Description: Gold mineralization is hosted within gossanous quartz-haematite veins in volcano-sedimentary lithologies of the Klein Aub - Rehoboth basin of the Irumide Belt, Namibia. Mineralization and hydrothermal alteration are restricted to deformed lithologies particularly the metasediments. Lithological relationships, geochemistry and metallogenic characteristics of the Irumide Belt suggest an intra-continental rift setting. Copper mineralization is well known along the length of the belt, from Klein Aub in the southwest to Ghanzi in the northeast, whereas gold mineralization appears restricted to the Klein Aub Rehoboth basin. The gold is envisaged as having being leached initially from graben fill sequences during rift closure and basin dewatering. Location of the mineralization is strongly controlled by structure and lithological contact zones. Such zones are percieved as having acted as conduit zones for escaping mineralized fluids during basin closure and deformation. Apart from the lack of an effective mineralizing trap, all features consistent with the development of an ore deposit are present. The largest mineralization traps within the area studied are shear zones followed by lithological contact zones. The Mebi and Blanks gold mines are developed over large shear zones while the Swartmodder and Neuras gold mines are situated over mineralized lithological contacts. The Swartmodder copper mine yielded ore from a mineralized schist enclave within granite. Copper and gold occurrences are attributed to two contrasting styles of mineralization. Copper mineralization is suggested to have developed during initial rifting of the belt (ie. stratabound sedimentary exhalative type), while the gold and minor copper resulted from rift closure and basin dewatering. Although no economical orebody was realized during the course of this study a model is proposed for the development of mineralization within the Irumide basement lithologies as a working hypothesis for future exploration.
- Full Text:
Trends in mobilisation and unionisation in South Africa and Germany: a comparative analysis
- Authors: Whiteley, Julianne Beverley
- Date: 2001
- Subjects: Industrial mobilization -- South Africa , Labor unions -- South Africa , Industrial mobilization -- Germany , Labor unions -- Germany , South Africa -- Economic conditions , Germany -- Economic conditions
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3332 , http://hdl.handle.net/10962/d1003125 , Industrial mobilization -- South Africa , Labor unions -- South Africa , Industrial mobilization -- Germany , Labor unions -- Germany , South Africa -- Economic conditions , Germany -- Economic conditions
- Description: The purpose of this study is to investigate long-term trends in the union membership of South Africa and Germany, and to highlight trends in unionisation in both of these countries over a period of time. The long-term aspect of this study differentiates it from more detailed specific studies concerned with the individual fortunes of confederations or unions. The changing fortunes of trade unions have been associated with changes in work organisation, the influence of institutional pressures, or long term changes in the economic cycle. All these factors may, of course, shape and be shaped by each other. From a comparative perspective this dissertation determines whether the fortunes of unions are ultimately a product of the long waves of an economic cycle, or if other factors, such as variations in union/state relations, changes in the forms of work organisation and shifts in the employment market, impact upon union membership and mobilisation. It is hoped that the comparison of a transitional and an advanced economy may shed new light on the causes of union growth and decline, and the impact of specific social, legal and cultural variables thereon. The theoretical frame of reference for this study emerged from literature pertaining to union growth and decline. This literature discusses the historical, economic and sectoral challenges that confront the identity of unions and their ability to mobilise membership within contemporary labour markets. The entire study relies heavily on primary data collected from a wide range of sources in both countries. This method facilitates the comparison and cross-checking of information, which ensures a full and balanced study. A synthesis of the facts obtained led to certain suggestions relating to the areas in which both South African and German labour organisations could adapt their agenda and interests to the changing nature of the employment market in order to avert membership decline. The methodology of this research draws from Skopol’s work which argues that social studies ought to be grounded in historical experience in order to make sense out of specific social events that occur today. The research design utilises an initial comparative historical-political analysis of the emergence of unionism in South Africa and Germany, so as to establish those factors which have, in the past, affected union growth and decline in both countries. Thereafter, the impact of contemporary economic and sectoral trends that reoccur in the South African and German labour markets are examined and compared, in order to establish their influence on the growth or decline of union membership in both countries in the future. This study consists of four sections. The first section comprises a historical dimension that uses Valenzuela’s work relating to the political nature of labour movements to establish those factors which, in the past, have affected union growth and decline. This is done to determine whether the type of insertion of labour movements into historical national political processes, and the links formed between trade unions and political parties influences membership growth or decline. The following three sections deal with the present challenges that may affect the unions in the future. Section Two deals with factors of economic recession (namely, poverty and unemployment) which confront trade unions in the 1990s. Hyman’s Theory of Disaggregation is applied to determine if recessive socio-economic factors can account for the strength of decline of unions, as opposed to union mobilisation being purely linked to transitions between long waves of the economy as Kelly suggests. The relevance of these theories to the rise and decline of unionism in South Africa and Germany is compared and contrasted. The third section determines whether changes to more flexible forms of work organisation and shifts in the employment market can account for the contrasting strength of the South African labour movement and the decline of the German labour movement today. The way in which these issues impact negatively upon union strength in South Africa and Germany in the 1990s is compared and contrasted, again using Hyman’s Theory of Disaggregation. The final section establishes whether or not the roles adopted by the South African and German labour movements during their confrontation with labour repressive regimes impacts upon their ability to attract union membership today, despite the constraints imposed upon unions by prevailing economic and structural uncertainties. Therefore the historicity of the South African and German labour movements, (based upon the findings of the first part of this study), is referred back to. At the same time, the reactions of the South African and German labour movements to prevailing economic and structural realities, (as examined in the second part of this research) are re-examined. Three conclusions are reached. Firstly, regardless of their strengths or weaknesses, all labour organisations are capable of adjusting to the adverse changes taking place in contemporary employment markets if they prove willing to advance and defend the interests of all who work, including those in the informal sector. If unions continue to neglect the informal labour market, they run the risk of being transposed by social movements that are antagonistic to trade unions or new expressions of the workforce’s latent collectivism. Secondly, in successfully playing a social movement role that led to the downfall of Apartheid in 1994, the South African labour movement has evolved as an energetic body with a dimension of recumbent militancy that attempts to adapt its identity to the changing nature of the employment market. This enables the South African labour movement to continue to attract membership despite the prevailing economic uncertainties. In contrast, forced co-operation and consensus within the German industrial relations arena since World War Two has resulted in a less dynamic union movement that lacks initiative in adapting to the changing nature of the employment market. The result is a decline in unionism. Finally, the fortunes of unions are not, as Kelly suggests, purely a product of economic cycles. Political climates can also influence mobilisation, as has occurred in both South Africa and Germany. This implies that mobilisation is not only activated by the economic dissatisfaction of a union movement.
- Full Text:
- Authors: Whiteley, Julianne Beverley
- Date: 2001
- Subjects: Industrial mobilization -- South Africa , Labor unions -- South Africa , Industrial mobilization -- Germany , Labor unions -- Germany , South Africa -- Economic conditions , Germany -- Economic conditions
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3332 , http://hdl.handle.net/10962/d1003125 , Industrial mobilization -- South Africa , Labor unions -- South Africa , Industrial mobilization -- Germany , Labor unions -- Germany , South Africa -- Economic conditions , Germany -- Economic conditions
- Description: The purpose of this study is to investigate long-term trends in the union membership of South Africa and Germany, and to highlight trends in unionisation in both of these countries over a period of time. The long-term aspect of this study differentiates it from more detailed specific studies concerned with the individual fortunes of confederations or unions. The changing fortunes of trade unions have been associated with changes in work organisation, the influence of institutional pressures, or long term changes in the economic cycle. All these factors may, of course, shape and be shaped by each other. From a comparative perspective this dissertation determines whether the fortunes of unions are ultimately a product of the long waves of an economic cycle, or if other factors, such as variations in union/state relations, changes in the forms of work organisation and shifts in the employment market, impact upon union membership and mobilisation. It is hoped that the comparison of a transitional and an advanced economy may shed new light on the causes of union growth and decline, and the impact of specific social, legal and cultural variables thereon. The theoretical frame of reference for this study emerged from literature pertaining to union growth and decline. This literature discusses the historical, economic and sectoral challenges that confront the identity of unions and their ability to mobilise membership within contemporary labour markets. The entire study relies heavily on primary data collected from a wide range of sources in both countries. This method facilitates the comparison and cross-checking of information, which ensures a full and balanced study. A synthesis of the facts obtained led to certain suggestions relating to the areas in which both South African and German labour organisations could adapt their agenda and interests to the changing nature of the employment market in order to avert membership decline. The methodology of this research draws from Skopol’s work which argues that social studies ought to be grounded in historical experience in order to make sense out of specific social events that occur today. The research design utilises an initial comparative historical-political analysis of the emergence of unionism in South Africa and Germany, so as to establish those factors which have, in the past, affected union growth and decline in both countries. Thereafter, the impact of contemporary economic and sectoral trends that reoccur in the South African and German labour markets are examined and compared, in order to establish their influence on the growth or decline of union membership in both countries in the future. This study consists of four sections. The first section comprises a historical dimension that uses Valenzuela’s work relating to the political nature of labour movements to establish those factors which, in the past, have affected union growth and decline. This is done to determine whether the type of insertion of labour movements into historical national political processes, and the links formed between trade unions and political parties influences membership growth or decline. The following three sections deal with the present challenges that may affect the unions in the future. Section Two deals with factors of economic recession (namely, poverty and unemployment) which confront trade unions in the 1990s. Hyman’s Theory of Disaggregation is applied to determine if recessive socio-economic factors can account for the strength of decline of unions, as opposed to union mobilisation being purely linked to transitions between long waves of the economy as Kelly suggests. The relevance of these theories to the rise and decline of unionism in South Africa and Germany is compared and contrasted. The third section determines whether changes to more flexible forms of work organisation and shifts in the employment market can account for the contrasting strength of the South African labour movement and the decline of the German labour movement today. The way in which these issues impact negatively upon union strength in South Africa and Germany in the 1990s is compared and contrasted, again using Hyman’s Theory of Disaggregation. The final section establishes whether or not the roles adopted by the South African and German labour movements during their confrontation with labour repressive regimes impacts upon their ability to attract union membership today, despite the constraints imposed upon unions by prevailing economic and structural uncertainties. Therefore the historicity of the South African and German labour movements, (based upon the findings of the first part of this study), is referred back to. At the same time, the reactions of the South African and German labour movements to prevailing economic and structural realities, (as examined in the second part of this research) are re-examined. Three conclusions are reached. Firstly, regardless of their strengths or weaknesses, all labour organisations are capable of adjusting to the adverse changes taking place in contemporary employment markets if they prove willing to advance and defend the interests of all who work, including those in the informal sector. If unions continue to neglect the informal labour market, they run the risk of being transposed by social movements that are antagonistic to trade unions or new expressions of the workforce’s latent collectivism. Secondly, in successfully playing a social movement role that led to the downfall of Apartheid in 1994, the South African labour movement has evolved as an energetic body with a dimension of recumbent militancy that attempts to adapt its identity to the changing nature of the employment market. This enables the South African labour movement to continue to attract membership despite the prevailing economic uncertainties. In contrast, forced co-operation and consensus within the German industrial relations arena since World War Two has resulted in a less dynamic union movement that lacks initiative in adapting to the changing nature of the employment market. The result is a decline in unionism. Finally, the fortunes of unions are not, as Kelly suggests, purely a product of economic cycles. Political climates can also influence mobilisation, as has occurred in both South Africa and Germany. This implies that mobilisation is not only activated by the economic dissatisfaction of a union movement.
- Full Text:
Stripe & dusk: a weekend odyssey
- Authors: Whitehorn, Daniel J
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:6018 , http://hdl.handle.net/10962/d1021242
- Description: I love to take in and create playful fantasy, tales set in wild and fantastic worlds peopled by wild and fantastic characters - dragons and dinosaurs, knights and robots, stars and penguins. My novella is the story of a quest set in a colourful and wondrous fantasy universe. Along the journey's tumultuous trajectory fantasy tropes and protocols are encountered, subverted, teased at, appropriated, and renovated, in order to create something both original and familiar all at once. I am happy to acknowledge and salute the influences of Terry Pratchett, Douglas Adams, Walter Moers and Manuela Draeger.
- Full Text:
- Authors: Whitehorn, Daniel J
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:6018 , http://hdl.handle.net/10962/d1021242
- Description: I love to take in and create playful fantasy, tales set in wild and fantastic worlds peopled by wild and fantastic characters - dragons and dinosaurs, knights and robots, stars and penguins. My novella is the story of a quest set in a colourful and wondrous fantasy universe. Along the journey's tumultuous trajectory fantasy tropes and protocols are encountered, subverted, teased at, appropriated, and renovated, in order to create something both original and familiar all at once. I am happy to acknowledge and salute the influences of Terry Pratchett, Douglas Adams, Walter Moers and Manuela Draeger.
- Full Text:
A study of the predators and parasites of Planococcus citri (Risso) (Homoptera) on vines in the Western Cape Province, South Africa
- Authors: Whitehead, Vincent Booth
- Date: 1959
- Subjects: Hemiptera , Parasites , Insect pests -- Biological control , Grapes -- Diseases and pests
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5896 , http://hdl.handle.net/10962/d1013425
- Description: [Introduction] In the Western Cape Province the mealybug, Planococcus citri (Risso), was first reported on vines in 1930 by Joubert (1943a). By 1935 this mealybug had spread to the Hex River Valley, and subsequently to all the main table grape producing areas of the Western Cape Province. At present Pl. citri is the most important insect pest of the table grape industry and can, if not effectively controlled, result in a loss of at least five per cent of the export table grape crop (Kriegler, 1954). Some preliminary work on the natural enemies of Pl. citri on vines was carried out by Stubbings in 1948, but no further work of this nature has been undertaken in this area since then. The fact that the natural enemies can be an effective check to this mealybug on vines in the Western Cape Province has been known for a number of years (Potgieter, 1937; Hattingh, 1943; Joubert, 1943a; Myburgh, 1951). The present work is an attempt to obtain some basic knowlege of the population fluctuations of the insects concerned in this biological control. Surveys undertaken have shown that there is a complex of primary, secondary and possibly tertiary Hynenopterous parasites associated with Pl. citri. The presence of hyperparasites reduces the efficiency of the primary parasitic Hymenoptera. The usefulness of these primary parasites is further reduced as they only occur in effective numbers for a short period of the year. On the other hand, although attacked by some parasites, the numerous coccinellids found preying on Pl. citri are of more importance in reducing the mealybug populations, as they are present on the vines in effective numbers for the greater part of the year.
- Full Text:
- Authors: Whitehead, Vincent Booth
- Date: 1959
- Subjects: Hemiptera , Parasites , Insect pests -- Biological control , Grapes -- Diseases and pests
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5896 , http://hdl.handle.net/10962/d1013425
- Description: [Introduction] In the Western Cape Province the mealybug, Planococcus citri (Risso), was first reported on vines in 1930 by Joubert (1943a). By 1935 this mealybug had spread to the Hex River Valley, and subsequently to all the main table grape producing areas of the Western Cape Province. At present Pl. citri is the most important insect pest of the table grape industry and can, if not effectively controlled, result in a loss of at least five per cent of the export table grape crop (Kriegler, 1954). Some preliminary work on the natural enemies of Pl. citri on vines was carried out by Stubbings in 1948, but no further work of this nature has been undertaken in this area since then. The fact that the natural enemies can be an effective check to this mealybug on vines in the Western Cape Province has been known for a number of years (Potgieter, 1937; Hattingh, 1943; Joubert, 1943a; Myburgh, 1951). The present work is an attempt to obtain some basic knowlege of the population fluctuations of the insects concerned in this biological control. Surveys undertaken have shown that there is a complex of primary, secondary and possibly tertiary Hynenopterous parasites associated with Pl. citri. The presence of hyperparasites reduces the efficiency of the primary parasitic Hymenoptera. The usefulness of these primary parasites is further reduced as they only occur in effective numbers for a short period of the year. On the other hand, although attacked by some parasites, the numerous coccinellids found preying on Pl. citri are of more importance in reducing the mealybug populations, as they are present on the vines in effective numbers for the greater part of the year.
- Full Text:
Relevant knowledge: content analysis of research conducted by South African psychology masters students (2008-2012
- Authors: Whitehead, Tracey
- Date: 2020
- Subjects: Psychology -- Research -- South Africa , Psychology -- Study and teaching (Higher) -- South Africa , Psychology students -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/167683 , vital:41503
- Description: In South Africa, Psychology has had a chequered past mainly due to its role in the justification of apartheid policies. Due to apartheid's socio-economic injustices, confidence in the applicability of psychological knowledge to South Africa's social problems was insufficient. Psychologists attempted to raise consciousness of the social relevance of psychology by contributing relevant knowledge and being reactive to social inequalities and related psychosocial issues affecting South Africa. This study aimed to conduct a content analysis of trends in research produced by Psychology Masters' students in the fields of Clinical, Counselling and Research psychology over a period of 5 years (2008-2012). The corpus of data was then compared with the key issues raised in the United Nations Development Programme's South Africa human development report (2003), along with a focus on articles published by Macleod (2004) and Macleod and Howell (2013). It emerged that Empirical Qualitative studies, based on post-modern frameworks, as well as HIV/AIDS, Knowledge Production, Assessment and Measurement and Programme development and evaluation, dominated psychological research. Participants were mainly urban, middle class adults living in the 3 wealthiest provinces. University students were the most popular participant group. While it is encouraging that students were attempting to engage with psychosocial issues, the limited number of key social issues addressed, the under-representation of certain sectors of the South African population, as well as the impact of socioeconomic status on well-being requires greater attention at Masters' level to ensure Psychology's psychosocial relevance.
- Full Text: false
- Authors: Whitehead, Tracey
- Date: 2020
- Subjects: Psychology -- Research -- South Africa , Psychology -- Study and teaching (Higher) -- South Africa , Psychology students -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/167683 , vital:41503
- Description: In South Africa, Psychology has had a chequered past mainly due to its role in the justification of apartheid policies. Due to apartheid's socio-economic injustices, confidence in the applicability of psychological knowledge to South Africa's social problems was insufficient. Psychologists attempted to raise consciousness of the social relevance of psychology by contributing relevant knowledge and being reactive to social inequalities and related psychosocial issues affecting South Africa. This study aimed to conduct a content analysis of trends in research produced by Psychology Masters' students in the fields of Clinical, Counselling and Research psychology over a period of 5 years (2008-2012). The corpus of data was then compared with the key issues raised in the United Nations Development Programme's South Africa human development report (2003), along with a focus on articles published by Macleod (2004) and Macleod and Howell (2013). It emerged that Empirical Qualitative studies, based on post-modern frameworks, as well as HIV/AIDS, Knowledge Production, Assessment and Measurement and Programme development and evaluation, dominated psychological research. Participants were mainly urban, middle class adults living in the 3 wealthiest provinces. University students were the most popular participant group. While it is encouraging that students were attempting to engage with psychosocial issues, the limited number of key social issues addressed, the under-representation of certain sectors of the South African population, as well as the impact of socioeconomic status on well-being requires greater attention at Masters' level to ensure Psychology's psychosocial relevance.
- Full Text: false
Lovedale 1930-1955 : the study of a missionary institution in its social, educational and political context
- White, Timothy Raymond Howard
- Authors: White, Timothy Raymond Howard
- Date: 1988
- Subjects: Lovedale Institution , History , South Africa , Education , African people
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:2527 , http://hdl.handle.net/10962/d1001856
- Description: Lovedale was founded by the Glasgow Missionary Society as an eduational centre for Africans. Education was to be adapted to the lives of the Africans which would be a departure from the English classical tradition. This meant that emphasis was placed on vocational training and that academic education focussed on the study of English rather than the Classics. But the importance of mother-tongue education was also stressed. The missionaries placed emphasis on village education, whereby the African would be taught skills and crafts that would be useful to him in life. Education, they argued, should also aim at character-training and at spreading the Christian message. They also wanted to see co-operation between the Church and the State in the education of the African. Vocational education was designed to create African artisans who would be able to compete with Whites; but it also aimed at emphasizing the importance of industry in building up character. The Lovedale Press illustrates vocational training in progress, dealing with the difficulties that arose when African printers came into competition with Whites. But the missionaries also used the Press to propagate the Christian message and to promote African literature. An ideological rift began to open up between the missions and the new Black political beliefs of the Second World War. This led to the Lovedale Riot which is considered in the broader framework of sociopolitical unrest within the country. After the 1948 Election an ideological rift also developed between the missions and the State. This study concludes by examining the introduction of the Bantu Education Act and the Lovedale response to this. It was felt that although Bantu Education threatened to undermine their educational endeavour, they should nevertheless cooperate with the system in order to save what they had built up.
- Full Text:
- Authors: White, Timothy Raymond Howard
- Date: 1988
- Subjects: Lovedale Institution , History , South Africa , Education , African people
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:2527 , http://hdl.handle.net/10962/d1001856
- Description: Lovedale was founded by the Glasgow Missionary Society as an eduational centre for Africans. Education was to be adapted to the lives of the Africans which would be a departure from the English classical tradition. This meant that emphasis was placed on vocational training and that academic education focussed on the study of English rather than the Classics. But the importance of mother-tongue education was also stressed. The missionaries placed emphasis on village education, whereby the African would be taught skills and crafts that would be useful to him in life. Education, they argued, should also aim at character-training and at spreading the Christian message. They also wanted to see co-operation between the Church and the State in the education of the African. Vocational education was designed to create African artisans who would be able to compete with Whites; but it also aimed at emphasizing the importance of industry in building up character. The Lovedale Press illustrates vocational training in progress, dealing with the difficulties that arose when African printers came into competition with Whites. But the missionaries also used the Press to propagate the Christian message and to promote African literature. An ideological rift began to open up between the missions and the new Black political beliefs of the Second World War. This led to the Lovedale Riot which is considered in the broader framework of sociopolitical unrest within the country. After the 1948 Election an ideological rift also developed between the missions and the State. This study concludes by examining the introduction of the Bantu Education Act and the Lovedale response to this. It was felt that although Bantu Education threatened to undermine their educational endeavour, they should nevertheless cooperate with the system in order to save what they had built up.
- Full Text:
Small town South Africa: the historical geography of selected Eastern Cape towns and current development initiatives within them
- White, Richard Charles Crookes
- Authors: White, Richard Charles Crookes
- Date: 2004 , 2013-06-03
- Subjects: Cities and towns -- South Africa -- Eastern Cape -- Growth , Cities and towns -- South Africa -- Population -- Statistics , Economic development -- South Africa -- Eastern Cape , Community development -- South Africa -- Eastern Cape , Eastern Cape (South Africa) -- History , Eastern Cape (South Africa) -- Economic conditions , Eastern Cape (South Africa) -- Social conditions
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:4805 , http://hdl.handle.net/10962/d1003288 , Cities and towns -- South Africa -- Eastern Cape -- Growth , Cities and towns -- South Africa -- Population -- Statistics , Economic development -- South Africa -- Eastern Cape , Community development -- South Africa -- Eastern Cape , Eastern Cape (South Africa) -- History , Eastern Cape (South Africa) -- Economic conditions , Eastern Cape (South Africa) -- Social conditions
- Description: Small towns can be seen as the fundamental building blocks of tbe urban system. Through time, some of these towns have lost the primary reason for their existence. Some towns that have been declining or stagnating include old mining and industrial towns, such as Indwe in the Eastern Cape or Welkom in the Free State. Some towns have also changed the main focus of tbeir economy, for example, from that of mining to that of tourism, as in the case of Utrecht in Kwa-Zulu Natal (Nel, 2002). In light of the above, this thesis seeks to critically evaluate what has happened in selected small towns in the Eastern Cape. The research investigated a number of towns in the Eastern Cape, looking at the history and influence of colonisation, population dynamics, education levels, employment opportunities, migration and the influence of capitalism on the economic and social structure of the town, as well as tbe evolution of its economy. The research sample consisted of interviews witb local historians, community leaders, development agencies and individuals who were benefiting from tbe various development initiatives/project in the towns. These interviews, in conjunction with the literature identified, were conducted in the selected small towns, assessing whether development was succeeding and, in conclusion, identifying witb reference to the study sites, what was learnt. The research process generated a number of lessons that need to be taken into consideration when attempting social and economic upliftment in small towns. These include: the need for leadership, support from the local population and the need for financial assistance to support and uplift the community. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Authors: White, Richard Charles Crookes
- Date: 2004 , 2013-06-03
- Subjects: Cities and towns -- South Africa -- Eastern Cape -- Growth , Cities and towns -- South Africa -- Population -- Statistics , Economic development -- South Africa -- Eastern Cape , Community development -- South Africa -- Eastern Cape , Eastern Cape (South Africa) -- History , Eastern Cape (South Africa) -- Economic conditions , Eastern Cape (South Africa) -- Social conditions
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:4805 , http://hdl.handle.net/10962/d1003288 , Cities and towns -- South Africa -- Eastern Cape -- Growth , Cities and towns -- South Africa -- Population -- Statistics , Economic development -- South Africa -- Eastern Cape , Community development -- South Africa -- Eastern Cape , Eastern Cape (South Africa) -- History , Eastern Cape (South Africa) -- Economic conditions , Eastern Cape (South Africa) -- Social conditions
- Description: Small towns can be seen as the fundamental building blocks of tbe urban system. Through time, some of these towns have lost the primary reason for their existence. Some towns that have been declining or stagnating include old mining and industrial towns, such as Indwe in the Eastern Cape or Welkom in the Free State. Some towns have also changed the main focus of tbeir economy, for example, from that of mining to that of tourism, as in the case of Utrecht in Kwa-Zulu Natal (Nel, 2002). In light of the above, this thesis seeks to critically evaluate what has happened in selected small towns in the Eastern Cape. The research investigated a number of towns in the Eastern Cape, looking at the history and influence of colonisation, population dynamics, education levels, employment opportunities, migration and the influence of capitalism on the economic and social structure of the town, as well as tbe evolution of its economy. The research sample consisted of interviews witb local historians, community leaders, development agencies and individuals who were benefiting from tbe various development initiatives/project in the towns. These interviews, in conjunction with the literature identified, were conducted in the selected small towns, assessing whether development was succeeding and, in conclusion, identifying witb reference to the study sites, what was learnt. The research process generated a number of lessons that need to be taken into consideration when attempting social and economic upliftment in small towns. These include: the need for leadership, support from the local population and the need for financial assistance to support and uplift the community. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
A taxonomic revision of the genus Synodontis (Pisces, Mochokidae) in Southern Africa
- Authors: White, Peter Nevins
- Date: 1987
- Subjects: Mochokidae -- Africa, Southern -- Classification , Synodontis -- Africa, Southern -- Classification
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5193 , http://hdl.handle.net/10962/d1001969 , Mochokidae -- Africa, Southern -- Classification , Synodontis -- Africa, Southern -- Classification
- Description: The alpha taxonomy of the southern African Synodontis is reviewed, based on the analysis of 48 characters. The previously descriptive characters of barbel branching and humeral process shape are compared by various quantitative methods. The variation in colour pattern is recorded with the aid of detailed line drawings. The definitions of head length, head width and humeral process length are altered slightly from their traditional descriptions to ensure greater consistency and precision in measurement. New characters include the size of the caudal fork, the number, shape and arrangement of the premaxillary teeth, and two measurements between the cranium and pectoral girdle. Both uni- and bivariate methods are used to record and compare the intraspecific variation of each character. Principal components analysis of 19 morphometric characters is used to assess the degree of similarity of nine allopatric populations of S. zambezensis. Ten species are recognized from the study area, two of which are described as new: S. nebulosus Peters 1852, S. zambezensis Peters 1852, S. nigromaculatus Boulenger 1905, S. njassae Keilhack 1908, S. woosnami Boulenger 1911, S. macrostigma Boulenger 1911, S. leopardinus Pellegrin 1914, S. thamalakanensis Fowler 1935, S. macrostoma sp.n. and S.vanderwaali sp.n. A key to their identification is provided. Characters are discussed in terms of their contribution to the identification of the southern African species and, where possible, suggestions made concerning the value of these characters to the taxonomy of the genus as a whole. The rejection of certain characters previously used in Synodontis keys is discussed and alternatives proposed. The state of southern African Synodontis taxonomy is assessed and recommendations for future research are given
- Full Text:
- Authors: White, Peter Nevins
- Date: 1987
- Subjects: Mochokidae -- Africa, Southern -- Classification , Synodontis -- Africa, Southern -- Classification
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5193 , http://hdl.handle.net/10962/d1001969 , Mochokidae -- Africa, Southern -- Classification , Synodontis -- Africa, Southern -- Classification
- Description: The alpha taxonomy of the southern African Synodontis is reviewed, based on the analysis of 48 characters. The previously descriptive characters of barbel branching and humeral process shape are compared by various quantitative methods. The variation in colour pattern is recorded with the aid of detailed line drawings. The definitions of head length, head width and humeral process length are altered slightly from their traditional descriptions to ensure greater consistency and precision in measurement. New characters include the size of the caudal fork, the number, shape and arrangement of the premaxillary teeth, and two measurements between the cranium and pectoral girdle. Both uni- and bivariate methods are used to record and compare the intraspecific variation of each character. Principal components analysis of 19 morphometric characters is used to assess the degree of similarity of nine allopatric populations of S. zambezensis. Ten species are recognized from the study area, two of which are described as new: S. nebulosus Peters 1852, S. zambezensis Peters 1852, S. nigromaculatus Boulenger 1905, S. njassae Keilhack 1908, S. woosnami Boulenger 1911, S. macrostigma Boulenger 1911, S. leopardinus Pellegrin 1914, S. thamalakanensis Fowler 1935, S. macrostoma sp.n. and S.vanderwaali sp.n. A key to their identification is provided. Characters are discussed in terms of their contribution to the identification of the southern African species and, where possible, suggestions made concerning the value of these characters to the taxonomy of the genus as a whole. The rejection of certain characters previously used in Synodontis keys is discussed and alternatives proposed. The state of southern African Synodontis taxonomy is assessed and recommendations for future research are given
- Full Text:
Fusing fact and fiction: biography and autobiography in the novels of Virginia Woolf
- Authors: White, Joshua Craig
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/4005 , vital:20580
- Description: Virginia Woolf was noted for a preoccupation with the genre of life-writing throughout her career. Her aims when it came to reshaping the nature of biographical and autobiographical literature were numerous. She veered away from the aggrandising and patriarchal methods with which Victorian biographers tended to depict their subjects. She increased the focus on women in life-writing, examining and subverting traditionally prescribed gender roles prevalent in both her society and the literature that reflected it, and advocating a balance between male and female patterns of thinking. She also devised a method of incorporating both basic biographical fact and aspects of fiction into life-writing in order to approach a more truthful depiction of a subject’s personality or character. This method is linked to the aforementioned balance of gendered thought patterns, since Woolf often aligns factuality with male thinking and the contrasting qualities of fiction, such as intuition, ambivalence and perspicacity, with female thinking. This thesis examines three novels which demonstrate Woolf’s constant preoccupation with combining fact and fiction in order to capture the essence of personality. In her debut novel, The Voyage Out, she presents Rachel Vinrace, who must achieve a balance of male-oriented fact with female-oriented insight in order to fashion a sufficient identity for herself and to identify others in a selective and judicious manner, thus being simultaneously autobiographical and biographical. In Orlando, Woolf explicitly subverts the traditional Victorian biography by depicting Vita Sackville-West as a man who transforms into a woman and remains living for over 400 years. In presenting such a character, Woolf posits that personality consists of and is influenced by myriad aspects of a person’s life that cannot be documented in the restrictive manner employed by Victorian biographers. Orlando’s essence being obfuscated by manifold “selves” attests to Woolf problematizing attempts to attain such an essence. The same challenge is particularly important in her autobiographical novel, To the Lighthouse, in which she transposes the traumas of her own life into a fictitious narrative in order to achieve catharsis for her and her readers, and to present the difficulty in capturing the essence of character. The conclusion that Woolf eventually posits is that personality cannot be reduced to an essence, but rather that it consists of idiosyncrasies that are various, intertwining, and capricious.
- Full Text:
- Authors: White, Joshua Craig
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/4005 , vital:20580
- Description: Virginia Woolf was noted for a preoccupation with the genre of life-writing throughout her career. Her aims when it came to reshaping the nature of biographical and autobiographical literature were numerous. She veered away from the aggrandising and patriarchal methods with which Victorian biographers tended to depict their subjects. She increased the focus on women in life-writing, examining and subverting traditionally prescribed gender roles prevalent in both her society and the literature that reflected it, and advocating a balance between male and female patterns of thinking. She also devised a method of incorporating both basic biographical fact and aspects of fiction into life-writing in order to approach a more truthful depiction of a subject’s personality or character. This method is linked to the aforementioned balance of gendered thought patterns, since Woolf often aligns factuality with male thinking and the contrasting qualities of fiction, such as intuition, ambivalence and perspicacity, with female thinking. This thesis examines three novels which demonstrate Woolf’s constant preoccupation with combining fact and fiction in order to capture the essence of personality. In her debut novel, The Voyage Out, she presents Rachel Vinrace, who must achieve a balance of male-oriented fact with female-oriented insight in order to fashion a sufficient identity for herself and to identify others in a selective and judicious manner, thus being simultaneously autobiographical and biographical. In Orlando, Woolf explicitly subverts the traditional Victorian biography by depicting Vita Sackville-West as a man who transforms into a woman and remains living for over 400 years. In presenting such a character, Woolf posits that personality consists of and is influenced by myriad aspects of a person’s life that cannot be documented in the restrictive manner employed by Victorian biographers. Orlando’s essence being obfuscated by manifold “selves” attests to Woolf problematizing attempts to attain such an essence. The same challenge is particularly important in her autobiographical novel, To the Lighthouse, in which she transposes the traumas of her own life into a fictitious narrative in order to achieve catharsis for her and her readers, and to present the difficulty in capturing the essence of character. The conclusion that Woolf eventually posits is that personality cannot be reduced to an essence, but rather that it consists of idiosyncrasies that are various, intertwining, and capricious.
- Full Text:
Anaesthesia in abalone, Haliotis midae
- Authors: White, Hermien Ilse
- Date: 1996
- Subjects: Abalones , Animal anesthesia
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5216 , http://hdl.handle.net/10962/d1005059 , Abalones , Animal anesthesia
- Description: The principle aim of this study was to isolate a chemical for the "safe anaesthesia" of abalone under commercial farming conditions. "Safe anaesthesia" implied that the anaesthetic had no immediate detrimental or long term sublethal effect on the abalone, that it was safe for the farmer, the consumer and the environment. Four chemicals, magnesium sulphate (MgS0₄), ethylenediamine tetra-acetic acid (EDTA), 2-phenoxyethanol and procaine hydrochloride were shown to effectively inhibit the in vitro contraction of isolated tarsal muscle of Haliotis midae. This identified them as potential anaesthetics for abalone. Since abalone, like any other aquaculture species, would be subject to frequent size-sorting during the grow-out period, size related dosage tables were developed for the four chemicals at a temperature of 18⁰C. Dosage tables were also developed for benzocaine and carbon dioxide (C0₂), Three size classes (5-15, 20-50 and 60-90 mm shell length (SL)) of abalone were considered. Only three of the six chemicals, viz. MgS0₄, 2-phenoxyethanol and CO₂, met the criteria of an effective abalone anaesthetic in that they effected rapid and mortality-free anaesthesia. The other three chemicals caused mortalities and were considered to be unsuitable for commercial scale anaesthesia. Temperature related dosage tables were then developed for MgS0₄ and CO₂, MgS0₄ concentrations and CO₂ flow rates for effective anaesthesia in abalone were found to be inversely related to temperature. The three size classes of H. midae were intermittently exposed to MgS0₄ and 2-phenoxyethanol anaesthesia for an eight month period to determine the effect of the anaesthetics on growth rate. Because of an increased resistance to the efficacy of 2-phenoxyethanol and high monthly mortalities it was concluded that this chemical was unsafe and unsuitable for commercial use. MgS0₄, on the other hand, had no effect on growth of abalone and no significant effect on the rate of mortality. MgS0₄ also had no measurable effect on H. midae muscle ultrastructure and, by implication had no effect on flesh texture. The use of MgS0₄ as an anaesthetic would, therefore, not affect marketability. Moreover, no magnesium residues were found in H. midae muscle tissue after short term or intermittent long term exposure to MgS0₄ anaesthesia. It was found that the three size classes of H. midae used in this study could be safely exposed to the recommended MgS0₄ concentrations for up to 40 minutes without any mortalities. This is more than adequate for routine farming procedures. Medium size abalone (20-50 mm SL) were also safely exposed to 14 g.100 ml⁻¹ MgS0₄ for up to 6 hours without any mortalities. The results have shown that MgS0₄ was undoubtedly the best chemical that was evaluated for anaesthesia of H. midae in this study. It fulfils the requirements set forth by the U.S.A. Food and Drug Administration (FDA) in that it is safe for the abalone, the farmer, the consumer and the environment.
- Full Text:
- Authors: White, Hermien Ilse
- Date: 1996
- Subjects: Abalones , Animal anesthesia
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5216 , http://hdl.handle.net/10962/d1005059 , Abalones , Animal anesthesia
- Description: The principle aim of this study was to isolate a chemical for the "safe anaesthesia" of abalone under commercial farming conditions. "Safe anaesthesia" implied that the anaesthetic had no immediate detrimental or long term sublethal effect on the abalone, that it was safe for the farmer, the consumer and the environment. Four chemicals, magnesium sulphate (MgS0₄), ethylenediamine tetra-acetic acid (EDTA), 2-phenoxyethanol and procaine hydrochloride were shown to effectively inhibit the in vitro contraction of isolated tarsal muscle of Haliotis midae. This identified them as potential anaesthetics for abalone. Since abalone, like any other aquaculture species, would be subject to frequent size-sorting during the grow-out period, size related dosage tables were developed for the four chemicals at a temperature of 18⁰C. Dosage tables were also developed for benzocaine and carbon dioxide (C0₂), Three size classes (5-15, 20-50 and 60-90 mm shell length (SL)) of abalone were considered. Only three of the six chemicals, viz. MgS0₄, 2-phenoxyethanol and CO₂, met the criteria of an effective abalone anaesthetic in that they effected rapid and mortality-free anaesthesia. The other three chemicals caused mortalities and were considered to be unsuitable for commercial scale anaesthesia. Temperature related dosage tables were then developed for MgS0₄ and CO₂, MgS0₄ concentrations and CO₂ flow rates for effective anaesthesia in abalone were found to be inversely related to temperature. The three size classes of H. midae were intermittently exposed to MgS0₄ and 2-phenoxyethanol anaesthesia for an eight month period to determine the effect of the anaesthetics on growth rate. Because of an increased resistance to the efficacy of 2-phenoxyethanol and high monthly mortalities it was concluded that this chemical was unsafe and unsuitable for commercial use. MgS0₄, on the other hand, had no effect on growth of abalone and no significant effect on the rate of mortality. MgS0₄ also had no measurable effect on H. midae muscle ultrastructure and, by implication had no effect on flesh texture. The use of MgS0₄ as an anaesthetic would, therefore, not affect marketability. Moreover, no magnesium residues were found in H. midae muscle tissue after short term or intermittent long term exposure to MgS0₄ anaesthesia. It was found that the three size classes of H. midae used in this study could be safely exposed to the recommended MgS0₄ concentrations for up to 40 minutes without any mortalities. This is more than adequate for routine farming procedures. Medium size abalone (20-50 mm SL) were also safely exposed to 14 g.100 ml⁻¹ MgS0₄ for up to 6 hours without any mortalities. The results have shown that MgS0₄ was undoubtedly the best chemical that was evaluated for anaesthesia of H. midae in this study. It fulfils the requirements set forth by the U.S.A. Food and Drug Administration (FDA) in that it is safe for the abalone, the farmer, the consumer and the environment.
- Full Text:
Limiting vulnerability exposure through effective patch management: threat mitigation through vulnerability remediation
- Authors: White, Dominic Stjohn Dolin
- Date: 2007 , 2007-02-08
- Subjects: Computer networks -- Security measures , Computer viruses , Computer security
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4629 , http://hdl.handle.net/10962/d1006510 , Computer networks -- Security measures , Computer viruses , Computer security
- Description: This document aims to provide a complete discussion on vulnerability and patch management. The first chapters look at the trends relating to vulnerabilities, exploits, attacks and patches. These trends describe the drivers of patch and vulnerability management and situate the discussion in the current security climate. The following chapters then aim to present both policy and technical solutions to the problem. The policies described lay out a comprehensive set of steps that can be followed by any organisation to implement their own patch management policy, including practical advice on integration with other policies, managing risk, identifying vulnerability, strategies for reducing downtime and generating metrics to measure progress. Having covered the steps that can be taken by users, a strategy describing how best a vendor should implement a related patch release policy is provided. An argument is made that current monthly patch release schedules are inadequate to allow users to most effectively and timeously mitigate vulnerabilities. The final chapters discuss the technical aspect of automating parts of the policies described. In particular the concept of 'defense in depth' is used to discuss additional strategies for 'buying time' during the patch process. The document then goes on to conclude that in the face of increasing malicious activity and more complex patching, solid frameworks such as those provided in this document are required to ensure an organisation can fully manage the patching process. However, more research is required to fully understand vulnerabilities and exploits. In particular more attention must be paid to threats, as little work as been done to fully understand threat-agent capabilities and activities from a day to day basis. , TeX output 2007.02.08:2212 , Adobe Acrobat 9.51 Paper Capture Plug-in
- Full Text:
- Authors: White, Dominic Stjohn Dolin
- Date: 2007 , 2007-02-08
- Subjects: Computer networks -- Security measures , Computer viruses , Computer security
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4629 , http://hdl.handle.net/10962/d1006510 , Computer networks -- Security measures , Computer viruses , Computer security
- Description: This document aims to provide a complete discussion on vulnerability and patch management. The first chapters look at the trends relating to vulnerabilities, exploits, attacks and patches. These trends describe the drivers of patch and vulnerability management and situate the discussion in the current security climate. The following chapters then aim to present both policy and technical solutions to the problem. The policies described lay out a comprehensive set of steps that can be followed by any organisation to implement their own patch management policy, including practical advice on integration with other policies, managing risk, identifying vulnerability, strategies for reducing downtime and generating metrics to measure progress. Having covered the steps that can be taken by users, a strategy describing how best a vendor should implement a related patch release policy is provided. An argument is made that current monthly patch release schedules are inadequate to allow users to most effectively and timeously mitigate vulnerabilities. The final chapters discuss the technical aspect of automating parts of the policies described. In particular the concept of 'defense in depth' is used to discuss additional strategies for 'buying time' during the patch process. The document then goes on to conclude that in the face of increasing malicious activity and more complex patching, solid frameworks such as those provided in this document are required to ensure an organisation can fully manage the patching process. However, more research is required to fully understand vulnerabilities and exploits. In particular more attention must be paid to threats, as little work as been done to fully understand threat-agent capabilities and activities from a day to day basis. , TeX output 2007.02.08:2212 , Adobe Acrobat 9.51 Paper Capture Plug-in
- Full Text:
The rule of Brigadier Oupa Gqozo in Ciskei: 4 March 1990 to 22 March 1994
- Authors: White, Colin Stewart
- Date: 2009
- Subjects: Gqozo, Oupa , Sebe, L L W (Lennox L W) , Massacres -- Bisho (South Africa) , Ciskei (South Africa) -- History -- 20th century , Ciskei (South Africa) -- Politics and government -- 20th century
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2616 , http://hdl.handle.net/10962/d1013360
- Description: Although the history of the Eastern Cape has been recorded from the eighteenth century, virtually nothing has been written about the political entity known as the independent Republic of Ciskei (1981 – 1994). This hiatus in our history, coupled with the fact that many of the official records of that period have been destroyed, make it imperative that the role-players of the period be contacted and their evidence be recorded before it is lost to prosperity. This need has motivated the writing of the thesis. The thesis commences with a brief description of the early history and constitutional development of Ciskei. It then has a substantial chapter on Lennox Sebe, the ruler of Ciskei from 1973 to 1990, who is described as the catalyst of Gqozo’s coup d’état. This is followed by a short personal biography of Oupa Gqozo, and his rise to the position of Brigadier in the Ciskei army. On 4 March 1990 Gqozo led the coup by the Ciskei Defence Force that dethroned Sebe. At the outset he ruled in an exemplary manner, but after being misled by South African agents he turned against the African National Congress and his own people. When he established his own party, the African Democratic Movement, and re-instated the hated headman system, civil war followed in Ciskei. Separate chapters in the thesis relate the various traumatic events that occurred during Gqozo’s reign: the killing of Anton Guzana and Charles Sebe; the dismissal of the senior officers of the CDF; the strife during 1991/2; the Bhisho Massacre; its aftermath; the mutiny by the security forces and Gqozo’s resignation on 22 March 1994. The thesis concludes that although Brigadier Gqozo respected the rule of law, and was free of corruption, he was devoid of the necessary academic qualifications, experience and ability, including the necessary insight and foresight, to rule a country. He became paranoid about his own safety and the possible overthrow of his government, and he was too easily swayed by others. In short, Gqozo was inept, rather than evil.
- Full Text:
- Authors: White, Colin Stewart
- Date: 2009
- Subjects: Gqozo, Oupa , Sebe, L L W (Lennox L W) , Massacres -- Bisho (South Africa) , Ciskei (South Africa) -- History -- 20th century , Ciskei (South Africa) -- Politics and government -- 20th century
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2616 , http://hdl.handle.net/10962/d1013360
- Description: Although the history of the Eastern Cape has been recorded from the eighteenth century, virtually nothing has been written about the political entity known as the independent Republic of Ciskei (1981 – 1994). This hiatus in our history, coupled with the fact that many of the official records of that period have been destroyed, make it imperative that the role-players of the period be contacted and their evidence be recorded before it is lost to prosperity. This need has motivated the writing of the thesis. The thesis commences with a brief description of the early history and constitutional development of Ciskei. It then has a substantial chapter on Lennox Sebe, the ruler of Ciskei from 1973 to 1990, who is described as the catalyst of Gqozo’s coup d’état. This is followed by a short personal biography of Oupa Gqozo, and his rise to the position of Brigadier in the Ciskei army. On 4 March 1990 Gqozo led the coup by the Ciskei Defence Force that dethroned Sebe. At the outset he ruled in an exemplary manner, but after being misled by South African agents he turned against the African National Congress and his own people. When he established his own party, the African Democratic Movement, and re-instated the hated headman system, civil war followed in Ciskei. Separate chapters in the thesis relate the various traumatic events that occurred during Gqozo’s reign: the killing of Anton Guzana and Charles Sebe; the dismissal of the senior officers of the CDF; the strife during 1991/2; the Bhisho Massacre; its aftermath; the mutiny by the security forces and Gqozo’s resignation on 22 March 1994. The thesis concludes that although Brigadier Gqozo respected the rule of law, and was free of corruption, he was devoid of the necessary academic qualifications, experience and ability, including the necessary insight and foresight, to rule a country. He became paranoid about his own safety and the possible overthrow of his government, and he was too easily swayed by others. In short, Gqozo was inept, rather than evil.
- Full Text:
The Stockenström judgment, the Warren report and the Griqualand West rebellion, 1876-8
- Authors: White, Anthony Nevins
- Date: 1978
- Subjects: Warren, Charles, Sir, 1840-1927 , Griqualand West -- History , Land tenure -- Griqualand West , Griqua Rising, 1878 , Griqua (African people) -- History , Tlharo (African people) -- History , Tlhaping (African people) -- History , Baga-maidi (African people) -- History , Stockenström, Andries, 1844-1880 , Genealogy , Korana (African people) -- History
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2591 , http://hdl.handle.net/10962/d1007239 , Warren, Charles, Sir, 1840-1927 , Griqualand West -- History , Land tenure -- Griqualand West , Griqua Rising, 1878 , Griqua (African people) -- History , Tlharo (African people) -- History , Tlhaping (African people) -- History , Baga-maidi (African people) -- History , Stockenström, Andries, 1844-1880 , Genealogy , Korana (African people) -- History
- Description: From Preface: South African frontiers periodically provided the backdrop for conflict between Blacks and Whites over land, and, in this respect, Griqualand West proved no exception. The arrival of the trekboers in the 1830s heralded the beginning of the land problem in Griqualand West, and the situation worsened with the discovery of diamonds and the subsequent influx of land-hungry Whites. By the 1870s the stage was then set for a major clash between Blacks and Whites with land as the central focus. The Griqualand West Administration tried to rectify this situation in 1875 by setting up a Land Court under Judge Andries Stockenström. Stockenström's judgment was highly controversial, as many Griqua and Blacks lost land, although no land which had been claimed by a Griqua or Black was granted to a White. As Stockenström had not resolved the land problem, the Griqualand West authorities brought in Captain Charles Warren to settle the matter of land ownership in the Province. The Warren Report was considered by all concerned to be fair, but it did not prevent the outbreak of hostilities in 1878. The two main foci of this study are, then, land ownership and the Rebellion and the link, if any, between them. The main sources for the work have been the Griqualand West archive in the Cape Archives, for the period 1872-1880, and various newspapers. The Cape and Imperial Blue Books were useful sources, especially on the military history of the rebellion. Interviews conducted in Bophuthatswana and Griqualand West clarified many obscure points and raised others, most of which have been answered in this work. A considerable number of contemporary published works were also consulted, but, although most mentioned the land problem and the Rebellion, few contained anything worthy of mention, especially with regard to the military history of the Rebellion. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Authors: White, Anthony Nevins
- Date: 1978
- Subjects: Warren, Charles, Sir, 1840-1927 , Griqualand West -- History , Land tenure -- Griqualand West , Griqua Rising, 1878 , Griqua (African people) -- History , Tlharo (African people) -- History , Tlhaping (African people) -- History , Baga-maidi (African people) -- History , Stockenström, Andries, 1844-1880 , Genealogy , Korana (African people) -- History
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2591 , http://hdl.handle.net/10962/d1007239 , Warren, Charles, Sir, 1840-1927 , Griqualand West -- History , Land tenure -- Griqualand West , Griqua Rising, 1878 , Griqua (African people) -- History , Tlharo (African people) -- History , Tlhaping (African people) -- History , Baga-maidi (African people) -- History , Stockenström, Andries, 1844-1880 , Genealogy , Korana (African people) -- History
- Description: From Preface: South African frontiers periodically provided the backdrop for conflict between Blacks and Whites over land, and, in this respect, Griqualand West proved no exception. The arrival of the trekboers in the 1830s heralded the beginning of the land problem in Griqualand West, and the situation worsened with the discovery of diamonds and the subsequent influx of land-hungry Whites. By the 1870s the stage was then set for a major clash between Blacks and Whites with land as the central focus. The Griqualand West Administration tried to rectify this situation in 1875 by setting up a Land Court under Judge Andries Stockenström. Stockenström's judgment was highly controversial, as many Griqua and Blacks lost land, although no land which had been claimed by a Griqua or Black was granted to a White. As Stockenström had not resolved the land problem, the Griqualand West authorities brought in Captain Charles Warren to settle the matter of land ownership in the Province. The Warren Report was considered by all concerned to be fair, but it did not prevent the outbreak of hostilities in 1878. The two main foci of this study are, then, land ownership and the Rebellion and the link, if any, between them. The main sources for the work have been the Griqualand West archive in the Cape Archives, for the period 1872-1880, and various newspapers. The Cape and Imperial Blue Books were useful sources, especially on the military history of the rebellion. Interviews conducted in Bophuthatswana and Griqualand West clarified many obscure points and raised others, most of which have been answered in this work. A considerable number of contemporary published works were also consulted, but, although most mentioned the land problem and the Rebellion, few contained anything worthy of mention, especially with regard to the military history of the Rebellion. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
The effect of geography, cultivation and harvest technique on the umckalin concentration and growth of pelargonium sidoides (Geraniaceae)
- Authors: White, Andrew Graeme
- Date: 2007
- Subjects: Pelargoniums , Geraniaceae , Botany -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Eastern Cape , Medicinal plants -- South Africa -- Eastern Cape , Coumarins
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4234 , http://hdl.handle.net/10962/d1003803 , Pelargoniums , Geraniaceae , Botany -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Eastern Cape , Medicinal plants -- South Africa -- Eastern Cape , Coumarins
- Description: Pelargonium sidoides DC. (Geraniaceae) root extracts are used in the Eastern Cape Province of South Africa as a traditional medicine for the treatment of respiratory tract and gastro-intestinal infections. Ethanolic extracts are used globally as herbal treatments for bronchitis, asthma and as an immune system booster. Despite documented exploitation of wild populations by illegal harvesters, this species has not been awarded a protected status. The high level of harvest in the years preceding this study prompted this investigation of the prospects for sustainable root harvest through wild harvest and greenhouse cultivation. A novel method was developed for the purification of umckalin, a bioactive constituent in root extracts, such that the root umckalin concentrations of wild and cultivated plants could be quantified by HPLC. As part of the cultivation experiments, the concentration of umckalin in roots was measured for plants across part of the species’ distribution range in the Eastern Cape Province. This survey revealed that root umckalin concentrations were inversely related to the average annual rainfall of the collection site (r² = 0.94, p = 0.007) and directly related to soil pH (r² = 0.97, p = 0.002). Thus, the possibility of inducing high umckalin concentrations in greenhouse-cultivated plants was investigated by subjecting plants to rapid and prolonged water stress treatments. Two leaf applied hormone treatments (cytokinin and gibberellin) and a root competition treatment with a fast growing annual (Conyza albida) were also investigated based on the potential function of umckalin in P. sidoides plants. These five treatments did not significantly affect root umckalin concentrations compared to well-watered controls. The results of further experiments suggested that umckalin production may have been influenced by the geographical origin and genetics of plants rather than environmental variation. Following wild harvest experiments, the regrowth of replanted shoots from which a standard proportion of the root was harvested showed that water availability affected shoot survival but not root regrowth rate. Regrowth rates were low, questioning the viability of wild harvest. In contrast, greenhouse cultivated plants showed ca. six times greater growth rates, supporting the cultivation of roots to supply future market demand.
- Full Text:
- Authors: White, Andrew Graeme
- Date: 2007
- Subjects: Pelargoniums , Geraniaceae , Botany -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Eastern Cape , Medicinal plants -- South Africa -- Eastern Cape , Coumarins
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4234 , http://hdl.handle.net/10962/d1003803 , Pelargoniums , Geraniaceae , Botany -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Eastern Cape , Medicinal plants -- South Africa -- Eastern Cape , Coumarins
- Description: Pelargonium sidoides DC. (Geraniaceae) root extracts are used in the Eastern Cape Province of South Africa as a traditional medicine for the treatment of respiratory tract and gastro-intestinal infections. Ethanolic extracts are used globally as herbal treatments for bronchitis, asthma and as an immune system booster. Despite documented exploitation of wild populations by illegal harvesters, this species has not been awarded a protected status. The high level of harvest in the years preceding this study prompted this investigation of the prospects for sustainable root harvest through wild harvest and greenhouse cultivation. A novel method was developed for the purification of umckalin, a bioactive constituent in root extracts, such that the root umckalin concentrations of wild and cultivated plants could be quantified by HPLC. As part of the cultivation experiments, the concentration of umckalin in roots was measured for plants across part of the species’ distribution range in the Eastern Cape Province. This survey revealed that root umckalin concentrations were inversely related to the average annual rainfall of the collection site (r² = 0.94, p = 0.007) and directly related to soil pH (r² = 0.97, p = 0.002). Thus, the possibility of inducing high umckalin concentrations in greenhouse-cultivated plants was investigated by subjecting plants to rapid and prolonged water stress treatments. Two leaf applied hormone treatments (cytokinin and gibberellin) and a root competition treatment with a fast growing annual (Conyza albida) were also investigated based on the potential function of umckalin in P. sidoides plants. These five treatments did not significantly affect root umckalin concentrations compared to well-watered controls. The results of further experiments suggested that umckalin production may have been influenced by the geographical origin and genetics of plants rather than environmental variation. Following wild harvest experiments, the regrowth of replanted shoots from which a standard proportion of the root was harvested showed that water availability affected shoot survival but not root regrowth rate. Regrowth rates were low, questioning the viability of wild harvest. In contrast, greenhouse cultivated plants showed ca. six times greater growth rates, supporting the cultivation of roots to supply future market demand.
- Full Text:
A study of the molecular variation between orbivirus proteins
- Authors: Whistler, Toni
- Date: 1985 , 2013-03-13
- Subjects: Proteins -- Analysis , Polypeptides , Bluetongue virus , Orbivirus infections
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3892 , http://hdl.handle.net/10962/d1003290 , Proteins -- Analysis , Polypeptides , Bluetongue virus , Orbivirus infections
- Description: The aim of this study was to initiate a structural analysis of the capsid polypeptides from several serotypes of bluetongue virus in order to provide insight into the relatedness and possible origins of the different serotypes. Tryptic peptide mapping of ¹²⁵I-labelled group antigen by ion exchange chromatography was used to assess the structural relatedness of seven BTV serotypes from Southern Africa, North America and Australia. Each serotype had several tyrosine containing tryptic peptides which were unique, but approximately 35% of the peptides analyzed were found to be highly conserved between all 7 serotypes. BTV-20 appeared to be closely related to BTV-B and these two serotypes with BTV-4 and BTV-17 appeared to form a closely knit central cluster. , KMBT_363 , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
- Authors: Whistler, Toni
- Date: 1985 , 2013-03-13
- Subjects: Proteins -- Analysis , Polypeptides , Bluetongue virus , Orbivirus infections
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3892 , http://hdl.handle.net/10962/d1003290 , Proteins -- Analysis , Polypeptides , Bluetongue virus , Orbivirus infections
- Description: The aim of this study was to initiate a structural analysis of the capsid polypeptides from several serotypes of bluetongue virus in order to provide insight into the relatedness and possible origins of the different serotypes. Tryptic peptide mapping of ¹²⁵I-labelled group antigen by ion exchange chromatography was used to assess the structural relatedness of seven BTV serotypes from Southern Africa, North America and Australia. Each serotype had several tyrosine containing tryptic peptides which were unique, but approximately 35% of the peptides analyzed were found to be highly conserved between all 7 serotypes. BTV-20 appeared to be closely related to BTV-B and these two serotypes with BTV-4 and BTV-17 appeared to form a closely knit central cluster. , KMBT_363 , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
An examination of the application of a geographical information system to rural development planning in Shixini Location, Transkei
- Authors: Whisken, Jarrell Braden
- Date: 1996
- Subjects: Rural development projects -- South Africa -- Transkei -- Shixini -- Planning , Shixini rural development project , Geographic information systems
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:4830 , http://hdl.handle.net/10962/d1005505 , Rural development projects -- South Africa -- Transkei -- Shixini -- Planning , Shixini rural development project , Geographic information systems
- Description: Digital geographical information systems (GIS) are tools for handling spatial data. Initially developed in First World countries, the technology is fast being taken up as a tool for handling spatial information by many Third World countries. GIS has been used for any number of applications involving spatial data, one of its primary uses has been in various planning fields where the advantages offered to planners by the technology have been highlighted by a number of publications and studies. GIS has been actively used as an urban planning tool in South Africa since the mid-1980s, (Vosloo 1987) however its use as a tool for rural planning has not developed to the same extent. As early as 1986 reference was made to the possible advantages offered by GIS to rural planning in South Africa (Fincham 1986). Despite this early recognition, the use of GIS in the rural planning sphere remains negligible. This study examines the. possible reasons for this by attempting to answer the question, "is GIS appropriate to rural planning in South Africa?" A number of approaches to rural planning are practised in South Africa. This study examines the appropriateness of applying GIS to one of these approaches, rural community development planning. Components of the study included i) an examination of the issues affecting the use of GIS in the rural development field, achieved through the use of a literature and questionnaire survey and ii) a case study examining the feasibility of incorporating GIS as a tool to the Shixini Development Project, Transkei. The study does not examine the intricacies of rural development theory, but it does acknowledge the fact that the approach employed by an organisation to rural development will have important implications concerning the use of a GIS in a project. The approach adopted to a project affects amongst others the administrative structure, the planning process, the flow of spatial data and its use, and consequently the possible role of GIS. The Shixini Rural Development Project was classified as a community development project, and as a result the study concentrates on this approach to rural development. This may limit the study to a particular planning process, however most rural case studies will have certain aims and factors which are unique to its situation. In order to place the results of the Shixini case study in a wider context the results of the study are linked to the questionnaire and literature survey. From this basis the usefulness of GIS in the rural development sphere was examined. Available literature on GIS indicates that the majority of problems associated with GIS rarely reside with the technology itself but rather with its supporting mechanisms. The study identified and concentrated on these support mechanisms, both at the project level and what is referred to in the study as the operating environment in South Africa. The results of the study revealed that a number of problems exist with regard to the attitude with which GIS is regarded in development organisations. It was found that these attitudes are legitimately based on a number of problems associated with incorporating the technology into project based organisations. It was concluded that GIS was appropriate to rural community planning, but is presently limited to certain aspects of the planning process and possibly to certain applications.
- Full Text:
- Authors: Whisken, Jarrell Braden
- Date: 1996
- Subjects: Rural development projects -- South Africa -- Transkei -- Shixini -- Planning , Shixini rural development project , Geographic information systems
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:4830 , http://hdl.handle.net/10962/d1005505 , Rural development projects -- South Africa -- Transkei -- Shixini -- Planning , Shixini rural development project , Geographic information systems
- Description: Digital geographical information systems (GIS) are tools for handling spatial data. Initially developed in First World countries, the technology is fast being taken up as a tool for handling spatial information by many Third World countries. GIS has been used for any number of applications involving spatial data, one of its primary uses has been in various planning fields where the advantages offered to planners by the technology have been highlighted by a number of publications and studies. GIS has been actively used as an urban planning tool in South Africa since the mid-1980s, (Vosloo 1987) however its use as a tool for rural planning has not developed to the same extent. As early as 1986 reference was made to the possible advantages offered by GIS to rural planning in South Africa (Fincham 1986). Despite this early recognition, the use of GIS in the rural planning sphere remains negligible. This study examines the. possible reasons for this by attempting to answer the question, "is GIS appropriate to rural planning in South Africa?" A number of approaches to rural planning are practised in South Africa. This study examines the appropriateness of applying GIS to one of these approaches, rural community development planning. Components of the study included i) an examination of the issues affecting the use of GIS in the rural development field, achieved through the use of a literature and questionnaire survey and ii) a case study examining the feasibility of incorporating GIS as a tool to the Shixini Development Project, Transkei. The study does not examine the intricacies of rural development theory, but it does acknowledge the fact that the approach employed by an organisation to rural development will have important implications concerning the use of a GIS in a project. The approach adopted to a project affects amongst others the administrative structure, the planning process, the flow of spatial data and its use, and consequently the possible role of GIS. The Shixini Rural Development Project was classified as a community development project, and as a result the study concentrates on this approach to rural development. This may limit the study to a particular planning process, however most rural case studies will have certain aims and factors which are unique to its situation. In order to place the results of the Shixini case study in a wider context the results of the study are linked to the questionnaire and literature survey. From this basis the usefulness of GIS in the rural development sphere was examined. Available literature on GIS indicates that the majority of problems associated with GIS rarely reside with the technology itself but rather with its supporting mechanisms. The study identified and concentrated on these support mechanisms, both at the project level and what is referred to in the study as the operating environment in South Africa. The results of the study revealed that a number of problems exist with regard to the attitude with which GIS is regarded in development organisations. It was found that these attitudes are legitimately based on a number of problems associated with incorporating the technology into project based organisations. It was concluded that GIS was appropriate to rural community planning, but is presently limited to certain aspects of the planning process and possibly to certain applications.
- Full Text:
Factors influencing ecological sustainability in the ostrich industry in the Little Karoo, South Africa
- Authors: Wheeler, Anita
- Date: 2014
- Subjects: Ostrich farms -- South Africa -- Little Karoo , Land degradation -- South Africa -- Little Karoo , Land use -- South Africa -- Little Karoo , Land degradation -- Environmental aspects -- South Africa -- Little Karoo , Conservation of natural resources -- South Africa -- Little Karoo , Sustainable development -- South Africa -- Little Karoo , Sustainable agriculture -- South Africa -- Little Karoo
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4259 , http://hdl.handle.net/10962/d1011741 , Ostrich farms -- South Africa -- Little Karoo , Land degradation -- South Africa -- Little Karoo , Land use -- South Africa -- Little Karoo , Land degradation -- Environmental aspects -- South Africa -- Little Karoo , Conservation of natural resources -- South Africa -- Little Karoo , Sustainable development -- South Africa -- Little Karoo , Sustainable agriculture -- South Africa -- Little Karoo
- Description: The Little Karoo, situated in the Succulent Karoo biome of South Africa, has been heavily transformed by land use, and only 8.6% of the remaining natural vegetation is considered to be intact. There is ample evidence that the main cause of degradation is the overstocking of ostriches, an industry that has been the major economic driver of the area for more than 150 years. The ostrich stocking rate currently recommended is 22 ha.ostrich⁻¹. A literature review was used to examine the evidence, assumptions and rationale on which recommended and actually implemented stocking rates for ostriches are based. No experimental evidence using ostriches was found that supported the recommended stocking rate as either ecologically or economically sustainable. From the literature, there appears to be a wide gap between what are considered to be economically and ecologically sustainable stocking rates, with the implication that these two aims may be impossible to reconcile when practicing ostrich farming on natural veld. A comparison of recommended with actual stocking rates among land managers in the Little Karoo showed that all land managers far exceeded the recommended agricultural stocking rate of 22.8 ha.ostrich⁻¹. However, the stocking rates reported by land managers to the South African Ostrich Business Chamber were found to accurately reflect actual numbers determined when whole flocks had to be slaughtered after an outbreak of avian influenza. The recommended stocking rate appeared to be irrelevant to ostrich flock breeders and there appeared to be a trade-off between profitable ostrich farming and sustainable land-use practices. This study also investigated the attitudes and behaviour of ostrich farmers. It was found that environmental attitude is most likely the most important characteristic of a land manager to ensure positive conservation behaviour. This characteristic was most prominent in younger land managers with larger farms. The last component of the study integrated the context and complexity of the long term social, economic and ecological sustainability of this industry through the development of a logic model. The results showed a general lack of linkages between industry elements which impact on achieving sustainability targets. Greater collaboration between industry role-players, organized agriculture and conservation organizations is required to find a balance between utilization and conservation in the ostrich industry.
- Full Text:
- Authors: Wheeler, Anita
- Date: 2014
- Subjects: Ostrich farms -- South Africa -- Little Karoo , Land degradation -- South Africa -- Little Karoo , Land use -- South Africa -- Little Karoo , Land degradation -- Environmental aspects -- South Africa -- Little Karoo , Conservation of natural resources -- South Africa -- Little Karoo , Sustainable development -- South Africa -- Little Karoo , Sustainable agriculture -- South Africa -- Little Karoo
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4259 , http://hdl.handle.net/10962/d1011741 , Ostrich farms -- South Africa -- Little Karoo , Land degradation -- South Africa -- Little Karoo , Land use -- South Africa -- Little Karoo , Land degradation -- Environmental aspects -- South Africa -- Little Karoo , Conservation of natural resources -- South Africa -- Little Karoo , Sustainable development -- South Africa -- Little Karoo , Sustainable agriculture -- South Africa -- Little Karoo
- Description: The Little Karoo, situated in the Succulent Karoo biome of South Africa, has been heavily transformed by land use, and only 8.6% of the remaining natural vegetation is considered to be intact. There is ample evidence that the main cause of degradation is the overstocking of ostriches, an industry that has been the major economic driver of the area for more than 150 years. The ostrich stocking rate currently recommended is 22 ha.ostrich⁻¹. A literature review was used to examine the evidence, assumptions and rationale on which recommended and actually implemented stocking rates for ostriches are based. No experimental evidence using ostriches was found that supported the recommended stocking rate as either ecologically or economically sustainable. From the literature, there appears to be a wide gap between what are considered to be economically and ecologically sustainable stocking rates, with the implication that these two aims may be impossible to reconcile when practicing ostrich farming on natural veld. A comparison of recommended with actual stocking rates among land managers in the Little Karoo showed that all land managers far exceeded the recommended agricultural stocking rate of 22.8 ha.ostrich⁻¹. However, the stocking rates reported by land managers to the South African Ostrich Business Chamber were found to accurately reflect actual numbers determined when whole flocks had to be slaughtered after an outbreak of avian influenza. The recommended stocking rate appeared to be irrelevant to ostrich flock breeders and there appeared to be a trade-off between profitable ostrich farming and sustainable land-use practices. This study also investigated the attitudes and behaviour of ostrich farmers. It was found that environmental attitude is most likely the most important characteristic of a land manager to ensure positive conservation behaviour. This characteristic was most prominent in younger land managers with larger farms. The last component of the study integrated the context and complexity of the long term social, economic and ecological sustainability of this industry through the development of a logic model. The results showed a general lack of linkages between industry elements which impact on achieving sustainability targets. Greater collaboration between industry role-players, organized agriculture and conservation organizations is required to find a balance between utilization and conservation in the ostrich industry.
- Full Text:
"Is more, less?" : insect-insect interactions in a biological control context using water hyacinth as a model
- Weyl, Philip Sebastian Richard
- Authors: Weyl, Philip Sebastian Richard
- Date: 2012
- Subjects: Water hyacinth -- South Africa -- Eastern Cape , Water hyacinth -- Biological control -- South Africa -- Eastern Cape , Insects as biological pest control agents , Miridae -- South Africa -- Eastern Cape , Beetles -- South Africa -- Eastern Cape , Competition (Biology)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5724 , http://hdl.handle.net/10962/d1005410 , Water hyacinth -- South Africa -- Eastern Cape , Water hyacinth -- Biological control -- South Africa -- Eastern Cape , Insects as biological pest control agents , Miridae -- South Africa -- Eastern Cape , Beetles -- South Africa -- Eastern Cape , Competition (Biology)
- Description: Interactions between insects have been shown to be important regulators of population abundances and dynamics as well as drivers of spatial segregation and distribution. These are important aspects of the ecology of insects used in biological control and may have implications for the overall success of a particular programme. In the history of biological control there has been a tendency to release a suite of agents against a weed, which in some cases has increased the level of success, while in others little change has been observed. In most of these cases the implications of increasing the level of complexity of the system is not taken into account and there is little research on the effect of releasing another agent into the system. A brief meta-analysis was done on all the biological control programmes initiated in South Africa. Emphasis was placed on multi-species releases and the effects that overlapping niches were having on the number of agents responsible for the success of a programme. Where overlapping niches were present among agents released the number of agents responsible for success was lower than the number established. Water hyacinth, Eichhornia crassipes (Martius) Solms-Laubach in South Africa has more arthropod agents released against it than anywhere else in the world, yet control has been variable. If the biology and host utilisation of all the agents against water hyacinth is considered, a definite overlap of niches is apparent in at least one life stage of all the agents. Therefore the probability of these insects interacting is high, especially if they are established at the same site in the field. Three of the insects released in South Africa have been selected to investigate possible interactions. They are Neochetina eichhorniae Warner, Neochetina bruchi Hustache and Eccritotarsus catarinensis (Carvalho). Y-tube olfactometer bioassays were used to measure responses of these insects to water hyacinth with prior feeding damage by either conspecifics or heterospecifics. This was done to determine whether olfactory cues played a role in host acceptability and avoidance of conspecifics or heterospecifics. The insects were given a choice between damaged and undamaged plants in various combinations. There was a significant preference for the undamaged plants when given a choice between undamaged and damaged plants. However when the insects were given a choice between two damaged plants there was no discrimination between heterospecific or conspecific damaged plants. This may indicate that there is little or no ecological cost for the insect to share a plant with other insects utilising a similar resource. Insect – insect interactions were investigated in a common garden plot experiment to measure the impact that pairwise combinations of the insect may have on their performance. There was a significant interaction between the mirid E. catarinensis and the weevil N. eichhorniae, with the weevil not performing as well when in combination with the mirid than when alone. Interestingly there was a negative interaction between the two weevil species when in combination, however it was impossible to determine which species was being affected if not both. None of the insects performed significantly better when in combination with another insect. A field study on Wriggleswade Dam in the Eastern Cape, South Africa was initiated to determine whether the relationship between the mirid E. catarinensis and the weevil N. eichhorniae could be determined in the field. The performance of the insects at the different sites in the field suggests that there was an interaction between the agents. This interaction did not limit the establishment of either insect at a site, but it did result in one insect dominating at a site over another. Interactions between the three species of insect tested in this thesis suggest that there are both negative and neutral relationships between them. A basic comparison between the insect performances from 15 sites around the country was done to determine if the spatial segregation observed in the field could be extrapolated to the natural South African situation. The interaction observed between N. eichhorniae and E. catarinensis does seem to extrapolate to the general South African situation where there is definite spatial segregation on a landscape level. The co–occurrence of the two Neochetina weevils at these sites suggests that the negative relationship observed between them in the common garden experiment does not extrapolate to the field. The results from this thesis suggest that the interactions between the agents tested would not limit establishment or have significant ramifications on performance. However, there may be spatial and temporal segregation of these species in the introduced range.
- Full Text:
- Authors: Weyl, Philip Sebastian Richard
- Date: 2012
- Subjects: Water hyacinth -- South Africa -- Eastern Cape , Water hyacinth -- Biological control -- South Africa -- Eastern Cape , Insects as biological pest control agents , Miridae -- South Africa -- Eastern Cape , Beetles -- South Africa -- Eastern Cape , Competition (Biology)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5724 , http://hdl.handle.net/10962/d1005410 , Water hyacinth -- South Africa -- Eastern Cape , Water hyacinth -- Biological control -- South Africa -- Eastern Cape , Insects as biological pest control agents , Miridae -- South Africa -- Eastern Cape , Beetles -- South Africa -- Eastern Cape , Competition (Biology)
- Description: Interactions between insects have been shown to be important regulators of population abundances and dynamics as well as drivers of spatial segregation and distribution. These are important aspects of the ecology of insects used in biological control and may have implications for the overall success of a particular programme. In the history of biological control there has been a tendency to release a suite of agents against a weed, which in some cases has increased the level of success, while in others little change has been observed. In most of these cases the implications of increasing the level of complexity of the system is not taken into account and there is little research on the effect of releasing another agent into the system. A brief meta-analysis was done on all the biological control programmes initiated in South Africa. Emphasis was placed on multi-species releases and the effects that overlapping niches were having on the number of agents responsible for the success of a programme. Where overlapping niches were present among agents released the number of agents responsible for success was lower than the number established. Water hyacinth, Eichhornia crassipes (Martius) Solms-Laubach in South Africa has more arthropod agents released against it than anywhere else in the world, yet control has been variable. If the biology and host utilisation of all the agents against water hyacinth is considered, a definite overlap of niches is apparent in at least one life stage of all the agents. Therefore the probability of these insects interacting is high, especially if they are established at the same site in the field. Three of the insects released in South Africa have been selected to investigate possible interactions. They are Neochetina eichhorniae Warner, Neochetina bruchi Hustache and Eccritotarsus catarinensis (Carvalho). Y-tube olfactometer bioassays were used to measure responses of these insects to water hyacinth with prior feeding damage by either conspecifics or heterospecifics. This was done to determine whether olfactory cues played a role in host acceptability and avoidance of conspecifics or heterospecifics. The insects were given a choice between damaged and undamaged plants in various combinations. There was a significant preference for the undamaged plants when given a choice between undamaged and damaged plants. However when the insects were given a choice between two damaged plants there was no discrimination between heterospecific or conspecific damaged plants. This may indicate that there is little or no ecological cost for the insect to share a plant with other insects utilising a similar resource. Insect – insect interactions were investigated in a common garden plot experiment to measure the impact that pairwise combinations of the insect may have on their performance. There was a significant interaction between the mirid E. catarinensis and the weevil N. eichhorniae, with the weevil not performing as well when in combination with the mirid than when alone. Interestingly there was a negative interaction between the two weevil species when in combination, however it was impossible to determine which species was being affected if not both. None of the insects performed significantly better when in combination with another insect. A field study on Wriggleswade Dam in the Eastern Cape, South Africa was initiated to determine whether the relationship between the mirid E. catarinensis and the weevil N. eichhorniae could be determined in the field. The performance of the insects at the different sites in the field suggests that there was an interaction between the agents. This interaction did not limit the establishment of either insect at a site, but it did result in one insect dominating at a site over another. Interactions between the three species of insect tested in this thesis suggest that there are both negative and neutral relationships between them. A basic comparison between the insect performances from 15 sites around the country was done to determine if the spatial segregation observed in the field could be extrapolated to the natural South African situation. The interaction observed between N. eichhorniae and E. catarinensis does seem to extrapolate to the general South African situation where there is definite spatial segregation on a landscape level. The co–occurrence of the two Neochetina weevils at these sites suggests that the negative relationship observed between them in the common garden experiment does not extrapolate to the field. The results from this thesis suggest that the interactions between the agents tested would not limit establishment or have significant ramifications on performance. However, there may be spatial and temporal segregation of these species in the introduced range.
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