An investigation of female leaders' perceptions of themselves and their roles as leaders in a Catholic School
- Authors: Kauaria, Vejanda
- Date: 2003
- Subjects: Catholic schools -- Namibia -- Administration Women school administrators -- Namibia School management and organization -- Namibia Educational leadership -- Namibia Women in public life -- Namibia Sex discrimination against women -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1626 , http://hdl.handle.net/10962/d1003508
- Description: The question of gender in leadership continues to be a contentious and poorly understood phenomenon. There seems general agreement that women do lead differently from men, and this study begins from that premise, focusing on a case in which leadership has traditionally been the domain of females. The case was chosen for its uniqueness, the assumption being that in these circumstances leadership may have developed particular characteristics. Following a qualitative approach (drawing on phenomenology), the study seeks to investigate how women leaders experience their roles as leaders. In-depth interviews made it possible for me to capture the perceptions and experiences of the three women leaders I interviewed. The study reveals that women are more inclined to use interactive styles of leadership. Women use leadership that is more participative, negotiative, cooperative, shared and collaborative. These characteristics are in line with the features of transformational leadership which differs from the more traditional transactional leadership that is more controlled and directive. The study has also shown that leadership develops from within the person of the leader as the leader is the one who spearheads the organization through vision, ideas, beliefs andassumptions. The findings of this study suggest thus that unless women are given chances to prove how they can lead, this new approach of leadership within them and that is required by modern organizations would be lost and leadership would remain relatively unchanged and undesirable. In the context of Namibia, this study should be of potential significance because of the rapid change that is taking place in the inclusion of women in leadership and management positions in education.
- Full Text:
- Date Issued: 2003
- Authors: Kauaria, Vejanda
- Date: 2003
- Subjects: Catholic schools -- Namibia -- Administration Women school administrators -- Namibia School management and organization -- Namibia Educational leadership -- Namibia Women in public life -- Namibia Sex discrimination against women -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1626 , http://hdl.handle.net/10962/d1003508
- Description: The question of gender in leadership continues to be a contentious and poorly understood phenomenon. There seems general agreement that women do lead differently from men, and this study begins from that premise, focusing on a case in which leadership has traditionally been the domain of females. The case was chosen for its uniqueness, the assumption being that in these circumstances leadership may have developed particular characteristics. Following a qualitative approach (drawing on phenomenology), the study seeks to investigate how women leaders experience their roles as leaders. In-depth interviews made it possible for me to capture the perceptions and experiences of the three women leaders I interviewed. The study reveals that women are more inclined to use interactive styles of leadership. Women use leadership that is more participative, negotiative, cooperative, shared and collaborative. These characteristics are in line with the features of transformational leadership which differs from the more traditional transactional leadership that is more controlled and directive. The study has also shown that leadership develops from within the person of the leader as the leader is the one who spearheads the organization through vision, ideas, beliefs andassumptions. The findings of this study suggest thus that unless women are given chances to prove how they can lead, this new approach of leadership within them and that is required by modern organizations would be lost and leadership would remain relatively unchanged and undesirable. In the context of Namibia, this study should be of potential significance because of the rapid change that is taking place in the inclusion of women in leadership and management positions in education.
- Full Text:
- Date Issued: 2003
An investigation of knowledge management implementation strategies
- Authors: Sunassee, Nakkiran N
- Date: 2003
- Subjects: Knowledge management , Strategic planning , Automobile industry and trade -- South Africa -- Management
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:1141 , http://hdl.handle.net/10962/d1002770 , Knowledge management , Strategic planning , Automobile industry and trade -- South Africa -- Management
- Description: The world is experiencing an era which has been termed the “knowledge age” or the “knowledge economy”. In this new context, knowledge is the primary commodity, and knowledge flows are regarded as the most important factors in the economy. The management of knowledge flows within organisations has become a crucial activity because many of the activities of organisations and the broader economic and social life today are knowledge-driven. In recent years, this managerial activity has become known as Knowledge Management. Equally important are the associated Knowledge Management implementation strategies. Driven by a need expressed by the South African Motor Vehicle Industry for a knowledge management implementation strategy tailored to their needs, this research aimed to develop a knowledge management implementation strategy suited to the needs of this industry. Following an extensive literature survey and a study of the target industry using Duffy’s Knowledge Benchmarking Questionnaire, a model of knowledge management implementation is proposed that is suited to the needs of the South African Motor Vehicle Industry. The model consists of three main interlinked components: Knowledge Management of the Organisation, People, and Infrastructure and Processes. Furthermore, the model recommends a holistic approach to managing knowledge. The critical success factors of the model were tested by means of a survey of industry opinions that validated certain aspects of the model and motivated for changes in others. Additionally, despite the focus of the model on the target industry, it is considered sufficiently appropriate for use by other organisations.
- Full Text:
- Date Issued: 2003
- Authors: Sunassee, Nakkiran N
- Date: 2003
- Subjects: Knowledge management , Strategic planning , Automobile industry and trade -- South Africa -- Management
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:1141 , http://hdl.handle.net/10962/d1002770 , Knowledge management , Strategic planning , Automobile industry and trade -- South Africa -- Management
- Description: The world is experiencing an era which has been termed the “knowledge age” or the “knowledge economy”. In this new context, knowledge is the primary commodity, and knowledge flows are regarded as the most important factors in the economy. The management of knowledge flows within organisations has become a crucial activity because many of the activities of organisations and the broader economic and social life today are knowledge-driven. In recent years, this managerial activity has become known as Knowledge Management. Equally important are the associated Knowledge Management implementation strategies. Driven by a need expressed by the South African Motor Vehicle Industry for a knowledge management implementation strategy tailored to their needs, this research aimed to develop a knowledge management implementation strategy suited to the needs of this industry. Following an extensive literature survey and a study of the target industry using Duffy’s Knowledge Benchmarking Questionnaire, a model of knowledge management implementation is proposed that is suited to the needs of the South African Motor Vehicle Industry. The model consists of three main interlinked components: Knowledge Management of the Organisation, People, and Infrastructure and Processes. Furthermore, the model recommends a holistic approach to managing knowledge. The critical success factors of the model were tested by means of a survey of industry opinions that validated certain aspects of the model and motivated for changes in others. Additionally, despite the focus of the model on the target industry, it is considered sufficiently appropriate for use by other organisations.
- Full Text:
- Date Issued: 2003
An investigation of the relative importance of the media in influencing the voting behaviour of Evelyn Hone College students in Lusaka during the December, 2001 presidential elections in Zambia
- Authors: Jere, Caesar
- Date: 2003
- Subjects: Voting -- Zambia Mass media -- Political aspects -- Zambia Presidents -- Zambia -- Election -- 2001
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3516 , http://hdl.handle.net/10962/d1007803
- Description: This study explores the relative importance of the media in influencing the electoral choices of a small group of Zambians, namely Evelyn Hone College students in Lusaka who participated in the December 2001 elections in Zambia. The study investigates the interplay of mediation between the lived cultural experiences of the sample of students and the impact of media messages. Students at Evelyn Hone College come from different ethnic groupings, social classes, religions and regions. They are exposed to both the state and the privately owned media, which represent a range of political viewpoints. The outcome of the December 2001 elections in Zambia gave the impression that people in urban areas in Zambia were less likely to vote on ethnic lines because they had easy access to different media, ranging from print to electronic, which provided them with diverse information about the political scene, and probably shaped their electoral choices. Conversely, their counterparts in the rural areas appeared to vote along ethnic lines, seemingly because of lack of exposure to the media. It was also assumed that most people in rural areas were not as modernized as their urban counterparts who were more exposed to enlightened sources of information such as professional groups and other elite social institutions which helped them to shape their political opinions than most rural people. The study attempts to establish to what extent the media impacted on the selected sample of urban students in the choice of their presidential candidates in the December 2001 elections in Zambia. The study further investigates to what extent other factors such as ethnic inclinations and other social predispositions influenced them in their choice of the candidates. The interviewees for this study were randomly drawn from a population of Evelyn Hone College students that voted in the December 2001 presidential elections in Zambia. The sample consisted of 30 randomly selected students who were purposely stratified in three focus groups of ten each. Each stratum represented the approximate ethnic equivalence of one of the presidential candidates who contested the December 2001 elections.
- Full Text:
- Date Issued: 2003
- Authors: Jere, Caesar
- Date: 2003
- Subjects: Voting -- Zambia Mass media -- Political aspects -- Zambia Presidents -- Zambia -- Election -- 2001
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3516 , http://hdl.handle.net/10962/d1007803
- Description: This study explores the relative importance of the media in influencing the electoral choices of a small group of Zambians, namely Evelyn Hone College students in Lusaka who participated in the December 2001 elections in Zambia. The study investigates the interplay of mediation between the lived cultural experiences of the sample of students and the impact of media messages. Students at Evelyn Hone College come from different ethnic groupings, social classes, religions and regions. They are exposed to both the state and the privately owned media, which represent a range of political viewpoints. The outcome of the December 2001 elections in Zambia gave the impression that people in urban areas in Zambia were less likely to vote on ethnic lines because they had easy access to different media, ranging from print to electronic, which provided them with diverse information about the political scene, and probably shaped their electoral choices. Conversely, their counterparts in the rural areas appeared to vote along ethnic lines, seemingly because of lack of exposure to the media. It was also assumed that most people in rural areas were not as modernized as their urban counterparts who were more exposed to enlightened sources of information such as professional groups and other elite social institutions which helped them to shape their political opinions than most rural people. The study attempts to establish to what extent the media impacted on the selected sample of urban students in the choice of their presidential candidates in the December 2001 elections in Zambia. The study further investigates to what extent other factors such as ethnic inclinations and other social predispositions influenced them in their choice of the candidates. The interviewees for this study were randomly drawn from a population of Evelyn Hone College students that voted in the December 2001 presidential elections in Zambia. The sample consisted of 30 randomly selected students who were purposely stratified in three focus groups of ten each. Each stratum represented the approximate ethnic equivalence of one of the presidential candidates who contested the December 2001 elections.
- Full Text:
- Date Issued: 2003
An object relational psychoanalysis of selected Tennessee Williams play texts
- Authors: Tosio, Paul
- Date: 2003
- Subjects: Williams, Tennessee, 1911-1983 Williams, Tennessee, 1911-1983 -- Knowledge -- Psychology Object relations (Psychoanalysis) Psychoanalysis Drama -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2150 , http://hdl.handle.net/10962/d1002382
- Description: Tennessee Williams is a playwright of great psychological depth. This thesis probes some of the complexities of his work through the use of Object Relational Psychoanalysis, specifically employing the theories of Melanie Klein, W.R.D. Fairbairn and Donald Winnicott. The Glass Menagerie, A Streetcar Named Desire, Cat On A Hot Tin Roof and The Night of The Iguana are analysed from this theoretical stance. All of these plays display great perceptiveness into the human condition, accurately portraying many psychological relational themes. Certain Object Relational themes become very apparent in these analyses. These themes include, Dependency (especially in The Glass Menagerie), Reparation (particularly in A Streetcar Named Desire), Falsehood (notably in Cat on a Hot Tin Roof), Idealisation (evident in The Night of The Iguana), Honest Empathetic Relations (apparent in Cat on a Hot Tin Roof and The Night of The Iguana) as well as Guilt, Object Loss, Sexual Guilt, and Obligation (recurring throughout these plays). It is advanced that Williams’ plays posses an honest and insightful understanding of human relations and, as such, are of contemporary value. This Thesis is not only an academic study, but also has practical applications for dramatists. With an increased understanding of the intrinsic tensions and motivations within such plays, offered by such psychoanalytic strategy, performance and staging of such work may be enhanced valuably.
- Full Text:
- Date Issued: 2003
- Authors: Tosio, Paul
- Date: 2003
- Subjects: Williams, Tennessee, 1911-1983 Williams, Tennessee, 1911-1983 -- Knowledge -- Psychology Object relations (Psychoanalysis) Psychoanalysis Drama -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2150 , http://hdl.handle.net/10962/d1002382
- Description: Tennessee Williams is a playwright of great psychological depth. This thesis probes some of the complexities of his work through the use of Object Relational Psychoanalysis, specifically employing the theories of Melanie Klein, W.R.D. Fairbairn and Donald Winnicott. The Glass Menagerie, A Streetcar Named Desire, Cat On A Hot Tin Roof and The Night of The Iguana are analysed from this theoretical stance. All of these plays display great perceptiveness into the human condition, accurately portraying many psychological relational themes. Certain Object Relational themes become very apparent in these analyses. These themes include, Dependency (especially in The Glass Menagerie), Reparation (particularly in A Streetcar Named Desire), Falsehood (notably in Cat on a Hot Tin Roof), Idealisation (evident in The Night of The Iguana), Honest Empathetic Relations (apparent in Cat on a Hot Tin Roof and The Night of The Iguana) as well as Guilt, Object Loss, Sexual Guilt, and Obligation (recurring throughout these plays). It is advanced that Williams’ plays posses an honest and insightful understanding of human relations and, as such, are of contemporary value. This Thesis is not only an academic study, but also has practical applications for dramatists. With an increased understanding of the intrinsic tensions and motivations within such plays, offered by such psychoanalytic strategy, performance and staging of such work may be enhanced valuably.
- Full Text:
- Date Issued: 2003
Applied studies of some Southern African blowflies (Diptera: Calliphoridae) of forensic importance
- Authors: Lunt, Nicola
- Date: 2003
- Subjects: Diptera -- South Africa , Blowflies -- South Africa , Forensic entomology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5803 , http://hdl.handle.net/10962/d1006202 , Diptera -- South Africa , Blowflies -- South Africa , Forensic entomology
- Description: Three major aspects of blowfly (Diptera: Calliphoridae) research were the focus of this study. Firstly, the phylogenetic relationships of 40 oestroid species from a variety of geographical localities were investigated using Cytochrome Oxidase b subunit I (COl) gene sequences. Maximum parsimony (MP) and Jukes-Cantor neighbor-joining (NJ) analyses both extracted a paraphyletic Calliphoridae, with the Calliphorinae-Luciliinae clade being sister to the Sarcophagidae. Short branch lengths within Chrysomya indicate a recent rapid radiation of this genus. Phormia and Protophormia either formed a sister clade to Chrysomya, or were embedded in this genus. Tree topologies were comparable between MP and NJ trees, but the positions of some genera were ambiguous. Secondly, developmental parameters and behaviour were investigated for four southern African species of forensically important blowflies viz. Chrysomya chloropyga, C. putoria, C. megacephala and Lucilia sericata, and ad hoc observations were made for Calliphora croceipalpis, Chrysomya marginalis and the predatory C. albiceps. Choice of oviposition substrate differed between species, mirroring substrate preferences in the field. Sexual dimorphism and dwarfism within a cohort complicated ageing maggots using size, but the use of developmental events (e.g. ecdysis) allowed ages to be determined unambiguously. Separate species status was supported for the previously synonymised C. chloropyga and C. putoria, by differences in maggot behaviour, larval growth rates and temperature optima. The proportion of total development time assigned to each larval instar and pupariation was variable among temperatures, but similar between congeneric species. Thirdly, since a negative linear relationship was found to occur between the developmental constant (K) and developmental zero (D₀) for both Calliphoridae and Sarcophagidae, the potential for predicting physiological parameters of unstudied taxa was investigated. Species and genera of Palaearctic origin generally had high K's and low D₀'s, and the reverse was true for the tropical taxa. It was found that both K and D₀ can be estimated for "unknown" taxa using the Felsenstein's Independent Contrasts (FIC) method of PDTree (Garland et al. 200 I), provided that branch lengths are relatively short and the phylogenetic position of the estimated taxon is unambiguous.
- Full Text:
- Date Issued: 2003
- Authors: Lunt, Nicola
- Date: 2003
- Subjects: Diptera -- South Africa , Blowflies -- South Africa , Forensic entomology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5803 , http://hdl.handle.net/10962/d1006202 , Diptera -- South Africa , Blowflies -- South Africa , Forensic entomology
- Description: Three major aspects of blowfly (Diptera: Calliphoridae) research were the focus of this study. Firstly, the phylogenetic relationships of 40 oestroid species from a variety of geographical localities were investigated using Cytochrome Oxidase b subunit I (COl) gene sequences. Maximum parsimony (MP) and Jukes-Cantor neighbor-joining (NJ) analyses both extracted a paraphyletic Calliphoridae, with the Calliphorinae-Luciliinae clade being sister to the Sarcophagidae. Short branch lengths within Chrysomya indicate a recent rapid radiation of this genus. Phormia and Protophormia either formed a sister clade to Chrysomya, or were embedded in this genus. Tree topologies were comparable between MP and NJ trees, but the positions of some genera were ambiguous. Secondly, developmental parameters and behaviour were investigated for four southern African species of forensically important blowflies viz. Chrysomya chloropyga, C. putoria, C. megacephala and Lucilia sericata, and ad hoc observations were made for Calliphora croceipalpis, Chrysomya marginalis and the predatory C. albiceps. Choice of oviposition substrate differed between species, mirroring substrate preferences in the field. Sexual dimorphism and dwarfism within a cohort complicated ageing maggots using size, but the use of developmental events (e.g. ecdysis) allowed ages to be determined unambiguously. Separate species status was supported for the previously synonymised C. chloropyga and C. putoria, by differences in maggot behaviour, larval growth rates and temperature optima. The proportion of total development time assigned to each larval instar and pupariation was variable among temperatures, but similar between congeneric species. Thirdly, since a negative linear relationship was found to occur between the developmental constant (K) and developmental zero (D₀) for both Calliphoridae and Sarcophagidae, the potential for predicting physiological parameters of unstudied taxa was investigated. Species and genera of Palaearctic origin generally had high K's and low D₀'s, and the reverse was true for the tropical taxa. It was found that both K and D₀ can be estimated for "unknown" taxa using the Felsenstein's Independent Contrasts (FIC) method of PDTree (Garland et al. 200 I), provided that branch lengths are relatively short and the phylogenetic position of the estimated taxon is unambiguous.
- Full Text:
- Date Issued: 2003
Bioaccumulation and histopathology of copper in Oreochromis mossambicus
- Authors: Naigaga, Irene
- Date: 2003
- Subjects: Mozambique tilapia , Copper , Marine toxins , Fishes -- Effect of water pollution on , Water -- Pollution -- Environmental aspects
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5234 , http://hdl.handle.net/10962/d1005077 , Mozambique tilapia , Copper , Marine toxins , Fishes -- Effect of water pollution on , Water -- Pollution -- Environmental aspects
- Description: Cu is one of the most toxic elements that affect fish populations when the fish are exposed to concentrations exceeding their tolerance. To investigate the effects of elementary Cu on aspects of bioconcentration, histology and behaviour, O. mossambicus were exposed to 0 and 0.75 ± 0.20 mg/l of Cu for 96 hours (short-term study), and 0, 0.11 ± 0.02, 0.29 ± 0.02, and 0.47 ± 0.04 mg/l of Cu for 64 days (longterm study) under controlled conditions in the laboratory. For the long-term study fish were sampled for gills, liver, and kidney Cu accumulation analysis after 1, 32 and 64 days of exposure and after 1, 2, 4, 16, 32, and 64 days for gills, liver and spleen histology analysis. Cu accumulation was concentration-duration dependent with the highest accumulation capacity in the liver. A multifactor linear model was developed for the relationship between exposure dose, exposure duration and Cu accumulation in the organs with the liver model: Log L = 3.35 + 0.85W + 0.31T (r² = 0.892) giving a better fit than the gills: G = −35.09 + 10.58W + 17.58T (r² = 0.632). Where L = Cu accumulation values in the liver, G = Cu accumulation values in the gills (both in μg/g dry mass); W = exposure dose in water (mg/l); and T = exposure time (days). Using this model Cu accumulation in organs can be estimated when exposure concentration and duration is known. This model should be tested under different conditions to determine the potential of the model in monitoring Cu toxicity in the environment. Lesions were observed in the liver, gills and spleen in all Cu treatments at all exposure concentration and exposure durations. However, the incidence and the degree of alteration was related to the concentration of Cu and duration of exposure. The sequential appearance of lesions in the order of, hepatic vacuolar degeneration, fatty degeneration and necrosis indicated a gradual increase in liver damage with larger duration of exposure time and increasing Cu concentration. The initial lesions in the gills were manifested as hypertrophy and hyperplasia of the gill epithelium causing increase in the thickness of the secondary lamellae, mucous cell hypertrophy and proliferation, mucous hypersecretion, proliferation of eosinophilic granule cells and hyperplasia of interlamellar cells. With increase in exposure time, necrosis of the eosinophilic granule cells, lamellar oedema, epithelial desquamation and increase in severity of lamellar hyperplasia were observed. These lesions indicated an initial defence mechanism of the fish against Cu toxicity followed by advanced histological changes that were related to Cu concentration and duration of exposure. Changes in the spleen were haemosiderosis, increase in the white pulp and macrophage centres, reduction in the red pulp, and necrosis suggesting that fish exposed to environmentally relevant levels of Cu may be histopathologically altered leading to anaemia and immunosuppression. Regression analysis was used to quantify the relationship between the total activity of the fish, and duration of exposure. There was a gradual decline in fish activity related to Cu concentration and duration of exposure before introducing food into the tanks. There was a constant activity after introducing food in the tanks at the control and 0.11 ± 0.02 mg/l Cu exposure levels irrespective of exposure time. Analysis of covariance (ANCOVA) was used to test for the difference in slopes between treatments. There was no significant difference (p > 0.05) between slopes of the control and 0.11 ± 0.02 mg/l Cu, and between 0.29 ± 0.02 and 47 ± 0.04 mg/l Cu before and after introducing food in the tanks. The slopes of both the control and 0.11 ± 0.02 mg/l Cu were significantly different from those of 0.29 ± 0.02 and 0.47 ± 0.04 mg/l Cu (p < 0.05). There were significant differences in the mean opercular movements per minute between treatments (p < 0.05). There was hyperventilation at 0.11 ± 0.02 mg/l Cu i.e. 87 ± 18 opercular movements per minute (mean ± standard deviation) and hypoventilation at 0.29 ± 0.02 and 0.47 ± 0.04 mg/l Cu i.e. 37 ± 34 and 13 ± 6 opercular movements per minute compared to the control. Hypo- and hyperventilation were related to the lesser and greater gill damage, respectively. In conclusion Cu accumulation and effects on histology of the liver, gills and were related to the concentration of Cu in the water and duration of exposure showing a gradual increase in incidence and intensity with larger duration of exposure time and increasing Cu concentration. The fish were initially able to homeostatically regulate and detoxify Cu. However, as the exposure continued, the homeostatic mechanism appears to have failed to cope with the increasing metal burden causing advanced histological changes.
- Full Text:
- Date Issued: 2003
- Authors: Naigaga, Irene
- Date: 2003
- Subjects: Mozambique tilapia , Copper , Marine toxins , Fishes -- Effect of water pollution on , Water -- Pollution -- Environmental aspects
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5234 , http://hdl.handle.net/10962/d1005077 , Mozambique tilapia , Copper , Marine toxins , Fishes -- Effect of water pollution on , Water -- Pollution -- Environmental aspects
- Description: Cu is one of the most toxic elements that affect fish populations when the fish are exposed to concentrations exceeding their tolerance. To investigate the effects of elementary Cu on aspects of bioconcentration, histology and behaviour, O. mossambicus were exposed to 0 and 0.75 ± 0.20 mg/l of Cu for 96 hours (short-term study), and 0, 0.11 ± 0.02, 0.29 ± 0.02, and 0.47 ± 0.04 mg/l of Cu for 64 days (longterm study) under controlled conditions in the laboratory. For the long-term study fish were sampled for gills, liver, and kidney Cu accumulation analysis after 1, 32 and 64 days of exposure and after 1, 2, 4, 16, 32, and 64 days for gills, liver and spleen histology analysis. Cu accumulation was concentration-duration dependent with the highest accumulation capacity in the liver. A multifactor linear model was developed for the relationship between exposure dose, exposure duration and Cu accumulation in the organs with the liver model: Log L = 3.35 + 0.85W + 0.31T (r² = 0.892) giving a better fit than the gills: G = −35.09 + 10.58W + 17.58T (r² = 0.632). Where L = Cu accumulation values in the liver, G = Cu accumulation values in the gills (both in μg/g dry mass); W = exposure dose in water (mg/l); and T = exposure time (days). Using this model Cu accumulation in organs can be estimated when exposure concentration and duration is known. This model should be tested under different conditions to determine the potential of the model in monitoring Cu toxicity in the environment. Lesions were observed in the liver, gills and spleen in all Cu treatments at all exposure concentration and exposure durations. However, the incidence and the degree of alteration was related to the concentration of Cu and duration of exposure. The sequential appearance of lesions in the order of, hepatic vacuolar degeneration, fatty degeneration and necrosis indicated a gradual increase in liver damage with larger duration of exposure time and increasing Cu concentration. The initial lesions in the gills were manifested as hypertrophy and hyperplasia of the gill epithelium causing increase in the thickness of the secondary lamellae, mucous cell hypertrophy and proliferation, mucous hypersecretion, proliferation of eosinophilic granule cells and hyperplasia of interlamellar cells. With increase in exposure time, necrosis of the eosinophilic granule cells, lamellar oedema, epithelial desquamation and increase in severity of lamellar hyperplasia were observed. These lesions indicated an initial defence mechanism of the fish against Cu toxicity followed by advanced histological changes that were related to Cu concentration and duration of exposure. Changes in the spleen were haemosiderosis, increase in the white pulp and macrophage centres, reduction in the red pulp, and necrosis suggesting that fish exposed to environmentally relevant levels of Cu may be histopathologically altered leading to anaemia and immunosuppression. Regression analysis was used to quantify the relationship between the total activity of the fish, and duration of exposure. There was a gradual decline in fish activity related to Cu concentration and duration of exposure before introducing food into the tanks. There was a constant activity after introducing food in the tanks at the control and 0.11 ± 0.02 mg/l Cu exposure levels irrespective of exposure time. Analysis of covariance (ANCOVA) was used to test for the difference in slopes between treatments. There was no significant difference (p > 0.05) between slopes of the control and 0.11 ± 0.02 mg/l Cu, and between 0.29 ± 0.02 and 47 ± 0.04 mg/l Cu before and after introducing food in the tanks. The slopes of both the control and 0.11 ± 0.02 mg/l Cu were significantly different from those of 0.29 ± 0.02 and 0.47 ± 0.04 mg/l Cu (p < 0.05). There were significant differences in the mean opercular movements per minute between treatments (p < 0.05). There was hyperventilation at 0.11 ± 0.02 mg/l Cu i.e. 87 ± 18 opercular movements per minute (mean ± standard deviation) and hypoventilation at 0.29 ± 0.02 and 0.47 ± 0.04 mg/l Cu i.e. 37 ± 34 and 13 ± 6 opercular movements per minute compared to the control. Hypo- and hyperventilation were related to the lesser and greater gill damage, respectively. In conclusion Cu accumulation and effects on histology of the liver, gills and were related to the concentration of Cu in the water and duration of exposure showing a gradual increase in incidence and intensity with larger duration of exposure time and increasing Cu concentration. The fish were initially able to homeostatically regulate and detoxify Cu. However, as the exposure continued, the homeostatic mechanism appears to have failed to cope with the increasing metal burden causing advanced histological changes.
- Full Text:
- Date Issued: 2003
Biology and demography of the spotted grunter Pomadasys commersonnii (Haemulidae) in South African waters
- Authors: Webb, Garth Anthony
- Date: 2003
- Subjects: Grunts (Fishes) -- South Africa , Grunts (Fishes) -- South Africa -- Ecology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5201 , http://hdl.handle.net/10962/d1003727 , Grunts (Fishes) -- South Africa , Grunts (Fishes) -- South Africa -- Ecology
- Description: The spotted grunter, Pomadasys commersonnii (Haemulidae), is an Indian Ocean coastal species, extending from India to False Bay but is absent from the central Indian Ocean islands. Its taste and texture has made it one of the most important line fish species and is caught by recreational and subsistence fisherman along the entire east coast of South Africa. Because of its inshore distribution, reduced catch rates and estuarine dependence the species was de-commercialised in 1992. Since then it has been investigated as a candidate species for mariculture. All previous work on the biology of the species was undertaken on fish collected in KwaZulu-Natal in the mid 1970's. All other information has been incidental and formed part of other ecological studies. All management plans for this species have been based on these data. To develop a more comprehensive management plan that incorporates the entire population of spotted grunter, it was deemed necessary to reassess the biology (including feeding biology, age and growth and reproductive biology) as well as the demography of the population throughout its distributional range in South African waters. Analysis of the diet of spotted grunter, collected in estuaries, indicates that crustaceans form the bulk of the prey selected. Amphipods, mysids and estuarine brachyura predominate the diet of fish < 300 mm TL. At 200 mm TL fish start to prey on anomurans, which are extracted from their burrows using the 'blowing' feeding mechanism. Anomurans, in particular Upogebia africana and Callianassa krausii, become the preferred prey of fish larger than 300 mm TL. The high degree of diet flexibility that spotted grunter exhibit means that the composition and abundance of the macrobenthos of a particular environment will dictate the diet of the species. Otolith growth zones were found to be deposited annually with the opaque zones being deposited during the austral summer (November - February). The optical definition of annual otolith growth rings differed significantly between geographic regions (namely: Western Cape, South Eastern Cape and KwaZulu-Natal). Growth (sex combined) offish in the Western Cape were best described by the specialised 3 parameter Von Bertalanffy with a relative error structure in the form : Lt = 753(1- e⁻°·¹⁵⁴ ⁽t +¹·⁶¹⁵⁾) while growth in the South Eastern Cape was best described by using the Schnute model with an absolute error structure in the form: Lt=177°·⁴¹⁶ + (676.2⁻¹·²⁶⁶ - 169.2⁻¹²⁶⁶)[1-e°·⁴¹⁶⁽t-t₁⁾ / 1-e°·⁴¹⁶⁽t₂-t₁⁾]¹/¹·²⁶⁶ whereas growth was best described in KwaZulu-Natal using the specialised 3 parameter Von Bertalanffy with a relative error structure in the form: Lt = 839(1-e°·¹⁷⁽t⁺°·⁴⁹⁾) In the South Eastern Cape, length at 50% maturity was found to be 305 mm TL for males. Since females with ripe & running or spent gonads were not found in the South Eastern Cape and since histological evidence suggests that females in the South Eastern Cape have spawned, it appears that spawning does not occur in the South Eastern Cape. These results suggest that adults are resident in the estuaries of the Western and South Eastern Cape and undertake the spring/summer, northward spawning migration to KwaZulu-Natal. After joining the resident spawner stock in KwaZulu-Natal and spawning in the offshore environment of KwaZulu-Natal, adults soon return to the southern regions of their distributional range. Juveniles recruit into KwaZulu-Natal estuaries at a length of 25 - 35 mm TL. A proportion of the eggs and larvae are transported southwards along the periphery of the western boundary Agulhas Current where juveniles (25 - 30 mm TL) recruit into the estuaries as far south as the Swartvlei estuary in the Western Cape. There is evidence to suggest that the fish, which occur in the Western Cape estuaries, have migrated there once they have attained sexual maturity further east.
- Full Text:
- Date Issued: 2003
- Authors: Webb, Garth Anthony
- Date: 2003
- Subjects: Grunts (Fishes) -- South Africa , Grunts (Fishes) -- South Africa -- Ecology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5201 , http://hdl.handle.net/10962/d1003727 , Grunts (Fishes) -- South Africa , Grunts (Fishes) -- South Africa -- Ecology
- Description: The spotted grunter, Pomadasys commersonnii (Haemulidae), is an Indian Ocean coastal species, extending from India to False Bay but is absent from the central Indian Ocean islands. Its taste and texture has made it one of the most important line fish species and is caught by recreational and subsistence fisherman along the entire east coast of South Africa. Because of its inshore distribution, reduced catch rates and estuarine dependence the species was de-commercialised in 1992. Since then it has been investigated as a candidate species for mariculture. All previous work on the biology of the species was undertaken on fish collected in KwaZulu-Natal in the mid 1970's. All other information has been incidental and formed part of other ecological studies. All management plans for this species have been based on these data. To develop a more comprehensive management plan that incorporates the entire population of spotted grunter, it was deemed necessary to reassess the biology (including feeding biology, age and growth and reproductive biology) as well as the demography of the population throughout its distributional range in South African waters. Analysis of the diet of spotted grunter, collected in estuaries, indicates that crustaceans form the bulk of the prey selected. Amphipods, mysids and estuarine brachyura predominate the diet of fish < 300 mm TL. At 200 mm TL fish start to prey on anomurans, which are extracted from their burrows using the 'blowing' feeding mechanism. Anomurans, in particular Upogebia africana and Callianassa krausii, become the preferred prey of fish larger than 300 mm TL. The high degree of diet flexibility that spotted grunter exhibit means that the composition and abundance of the macrobenthos of a particular environment will dictate the diet of the species. Otolith growth zones were found to be deposited annually with the opaque zones being deposited during the austral summer (November - February). The optical definition of annual otolith growth rings differed significantly between geographic regions (namely: Western Cape, South Eastern Cape and KwaZulu-Natal). Growth (sex combined) offish in the Western Cape were best described by the specialised 3 parameter Von Bertalanffy with a relative error structure in the form : Lt = 753(1- e⁻°·¹⁵⁴ ⁽t +¹·⁶¹⁵⁾) while growth in the South Eastern Cape was best described by using the Schnute model with an absolute error structure in the form: Lt=177°·⁴¹⁶ + (676.2⁻¹·²⁶⁶ - 169.2⁻¹²⁶⁶)[1-e°·⁴¹⁶⁽t-t₁⁾ / 1-e°·⁴¹⁶⁽t₂-t₁⁾]¹/¹·²⁶⁶ whereas growth was best described in KwaZulu-Natal using the specialised 3 parameter Von Bertalanffy with a relative error structure in the form: Lt = 839(1-e°·¹⁷⁽t⁺°·⁴⁹⁾) In the South Eastern Cape, length at 50% maturity was found to be 305 mm TL for males. Since females with ripe & running or spent gonads were not found in the South Eastern Cape and since histological evidence suggests that females in the South Eastern Cape have spawned, it appears that spawning does not occur in the South Eastern Cape. These results suggest that adults are resident in the estuaries of the Western and South Eastern Cape and undertake the spring/summer, northward spawning migration to KwaZulu-Natal. After joining the resident spawner stock in KwaZulu-Natal and spawning in the offshore environment of KwaZulu-Natal, adults soon return to the southern regions of their distributional range. Juveniles recruit into KwaZulu-Natal estuaries at a length of 25 - 35 mm TL. A proportion of the eggs and larvae are transported southwards along the periphery of the western boundary Agulhas Current where juveniles (25 - 30 mm TL) recruit into the estuaries as far south as the Swartvlei estuary in the Western Cape. There is evidence to suggest that the fish, which occur in the Western Cape estuaries, have migrated there once they have attained sexual maturity further east.
- Full Text:
- Date Issued: 2003
Botanical inventory and phenology in relation to foraging behaviour of the Cape honeybees (Apis Mellifera Capensis) at a site in the Eastern Cape, South Africa
- Authors: Merti, Admassu Addi
- Date: 2003
- Subjects: Fynbos -- South Africa -- Eastern Cape , Honeybee -- South Africa -- Eastern Cape , Honey plants -- South Africa -- Eastern Cape , Honeybee -- South Africa -- Eastern Cape -- Food , Plant ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4214 , http://hdl.handle.net/10962/d1003783 , Fynbos -- South Africa -- Eastern Cape , Honeybee -- South Africa -- Eastern Cape , Honey plants -- South Africa -- Eastern Cape , Honeybee -- South Africa -- Eastern Cape -- Food , Plant ecology -- South Africa -- Eastern Cape
- Description: From an apicultural point of view the Cape fynbos is under-utilised and our knowledge of its utilization by the Cape honeybees is incomplete. The key aim of this study was to test the hypothesis that the Cape honeybees utilize the fynbos species as the preferred source of nectar and pollen. Subsidiary aims included distinguishing vegetation communities in the area, identifying pollen and nectar sources, the relationship between brood population and seasonal pollen collection patterns, examining the effect of meteorological factors on pollen collection. The study site was on Rivendell Farm within the Eastern Cape Albany district: an area of high species richness. A checklist of vascular plant species was produced revealing 97 families, 271 genera and 448 species. A classification by two-way indicator species (TWINSPAN) recognized seven vegetation communities: Forest, Bush clumps, Acacia savanna, Grassland, Grassy fynbos, Fynbos and Shrubland. Direct field observations of the foraging of Cape honeybees identified 54 nectar and pollen source plant species. Honeybee pollen loads trapped from four colonies of hives identified 37 pollen source plants of which Metalasia muricata, Eucalyptus grandis, Eucalyptus camaldulensis, Erica chamissonis, Helichrysum odoratissimum, Helichrysum anomalum, Crassula cultrata and Acacia longifolia were the predominant pollen source plants. It was also found that 60% of pollen yield derived from fynbos vegetation. The pollen source plants came from both Cape endemic and from nonendemic species. Thus we reject the hypothesis that Cape honeybees selectively forage fynbos species as a preferred source of pollen and nectar. The examination of the effect of temperature, wind-speed and temperature on pollen collection activity of honeybees revealed that: a temperature range of between 14°C to 26°C was optimal for pollen collection; wind speeds of up to 4m/s were conducive for pollen collection; relative humidity was found to have no significant influence on pollen collection. Pollen collection and brood rearing patterns are positively correlated with flowering intensities, but we found in our Eastern Cape study site that brood rearing was not limited to the spring flowering season but did extend to the end of summer. In order to determine the available nectar yield of common plant species hourly secretion of nectar volumes was measured for 24 hours to determine the variation of available nectar during different times of the day. In all nectar producing species the nectar volume was high in the early morning and declined as the day progressed. We found that the volume of available nectar was affected by prevailing temperature and humidity around the flowers.
- Full Text:
- Date Issued: 2003
- Authors: Merti, Admassu Addi
- Date: 2003
- Subjects: Fynbos -- South Africa -- Eastern Cape , Honeybee -- South Africa -- Eastern Cape , Honey plants -- South Africa -- Eastern Cape , Honeybee -- South Africa -- Eastern Cape -- Food , Plant ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4214 , http://hdl.handle.net/10962/d1003783 , Fynbos -- South Africa -- Eastern Cape , Honeybee -- South Africa -- Eastern Cape , Honey plants -- South Africa -- Eastern Cape , Honeybee -- South Africa -- Eastern Cape -- Food , Plant ecology -- South Africa -- Eastern Cape
- Description: From an apicultural point of view the Cape fynbos is under-utilised and our knowledge of its utilization by the Cape honeybees is incomplete. The key aim of this study was to test the hypothesis that the Cape honeybees utilize the fynbos species as the preferred source of nectar and pollen. Subsidiary aims included distinguishing vegetation communities in the area, identifying pollen and nectar sources, the relationship between brood population and seasonal pollen collection patterns, examining the effect of meteorological factors on pollen collection. The study site was on Rivendell Farm within the Eastern Cape Albany district: an area of high species richness. A checklist of vascular plant species was produced revealing 97 families, 271 genera and 448 species. A classification by two-way indicator species (TWINSPAN) recognized seven vegetation communities: Forest, Bush clumps, Acacia savanna, Grassland, Grassy fynbos, Fynbos and Shrubland. Direct field observations of the foraging of Cape honeybees identified 54 nectar and pollen source plant species. Honeybee pollen loads trapped from four colonies of hives identified 37 pollen source plants of which Metalasia muricata, Eucalyptus grandis, Eucalyptus camaldulensis, Erica chamissonis, Helichrysum odoratissimum, Helichrysum anomalum, Crassula cultrata and Acacia longifolia were the predominant pollen source plants. It was also found that 60% of pollen yield derived from fynbos vegetation. The pollen source plants came from both Cape endemic and from nonendemic species. Thus we reject the hypothesis that Cape honeybees selectively forage fynbos species as a preferred source of pollen and nectar. The examination of the effect of temperature, wind-speed and temperature on pollen collection activity of honeybees revealed that: a temperature range of between 14°C to 26°C was optimal for pollen collection; wind speeds of up to 4m/s were conducive for pollen collection; relative humidity was found to have no significant influence on pollen collection. Pollen collection and brood rearing patterns are positively correlated with flowering intensities, but we found in our Eastern Cape study site that brood rearing was not limited to the spring flowering season but did extend to the end of summer. In order to determine the available nectar yield of common plant species hourly secretion of nectar volumes was measured for 24 hours to determine the variation of available nectar during different times of the day. In all nectar producing species the nectar volume was high in the early morning and declined as the day progressed. We found that the volume of available nectar was affected by prevailing temperature and humidity around the flowers.
- Full Text:
- Date Issued: 2003
Cimetidine as a free radical scavenger
- Authors: Lambat, Zaynab Yusuf
- Date: 2003
- Subjects: Cimetidine , Cimetidine -- Physiological effect , Cimetidine -- Therapeutic use , Alzheimer's disease -- Treatment , Cancer -- Treatment , Free radicals (Chemistry) -- Physiological effect
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3766 , http://hdl.handle.net/10962/d1003244 , Cimetidine , Cimetidine -- Physiological effect , Cimetidine -- Therapeutic use , Alzheimer's disease -- Treatment , Cancer -- Treatment , Free radicals (Chemistry) -- Physiological effect
- Description: The present study was undertaken to determine the effects and possible mechanism of action of cimetidine in cancer and Alzheimer’s disease (AD). Throughout this study emphasis is placed on free radical levels since the magnitude of the relationship between diseases and the levels of free radicals vary from one disease to another. Studies were carried out to examine the effect of cimetidine on free radical levels using superoxide formation and lipid peroxidation as indicators of free radical levels. The experiments revealed that addition of cimetidine, especially in high concentrations (0.5 and 1.0 x10-6 M) significantly inhibited WHCO6 cancer cell growth rather than cancer cell growth, as no normal control was available. Free radical formation as well as hydroxyl radical formation were reduced in the deoxyribose assay. In addition, cimetidine exhibits properties of binding to metals such as copper and iron. To maintain consistency in the experiments, a WHCO6 (Wits Human Carcinoma of the Oesophagus) cell line was used to investigate the effect of cimetidine in cancer. Neurodegeneration was induced in the rat brain using neurotoxins such as cyanide to investigate the relationship between cimetidine in AD. A decrease in cancer cell growth was accompanied by a concomitant decrease in the levels of free radicals and lipid peroxidation, suggesting that the growth-inhibitory effects of cimetidine on WHCO6 cancer cells in vitro may be due to free radical scavenging properties. This proposal was further strengthened by determination of free radical levels in the rat brain. After treatment with neurotoxins to induce neurodegeneration, the levels of free radicals in the rat brain suggest that addition of cimetidine reduces free radical levels in the rat brain in a dosedependent manner. Further experiments were done in an attempt to uncover the underlying mechanism by which cimetidine exhibits free radical scavenging properties. Metal binding studies were done using electrochemical, HPLC and UV/Vis studies. The results show that cimetidine binds iron and copper. These metals have been implicated in free radical production via the Fenton reaction. By binding with cimetidine the metals become unavailable to produce free radicals and hence cimetidine indirectly reduces the formation of free radicals. The final experiment was the determination of cimetidine as a hydroxyl radical scavenger in the deoxyribose assay. Cimetidine was shown to act as a potent hydroxyl radical scavenger, thereby confirming its activity as a free radical scavenger. In addition, cimetidine protects against damage to the deoxyribose sugar, a component of DNA. Whilst there are many theories that explain the therapeutic role of cimetidine in degenerative disease, the actual mechanism of the role of cimetidine is emphasized as a free radical scavenger. Regardless of the mechanism of action, cimetidine does inhibit tumour growth according to this study and also reduce free radical levels in neurodegeneration, which suggests a role for cimetidine as a possible additive in treatment of patients with such disease states. These findings have important clinical implications, and needs to be investigated further.
- Full Text:
- Date Issued: 2003
- Authors: Lambat, Zaynab Yusuf
- Date: 2003
- Subjects: Cimetidine , Cimetidine -- Physiological effect , Cimetidine -- Therapeutic use , Alzheimer's disease -- Treatment , Cancer -- Treatment , Free radicals (Chemistry) -- Physiological effect
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3766 , http://hdl.handle.net/10962/d1003244 , Cimetidine , Cimetidine -- Physiological effect , Cimetidine -- Therapeutic use , Alzheimer's disease -- Treatment , Cancer -- Treatment , Free radicals (Chemistry) -- Physiological effect
- Description: The present study was undertaken to determine the effects and possible mechanism of action of cimetidine in cancer and Alzheimer’s disease (AD). Throughout this study emphasis is placed on free radical levels since the magnitude of the relationship between diseases and the levels of free radicals vary from one disease to another. Studies were carried out to examine the effect of cimetidine on free radical levels using superoxide formation and lipid peroxidation as indicators of free radical levels. The experiments revealed that addition of cimetidine, especially in high concentrations (0.5 and 1.0 x10-6 M) significantly inhibited WHCO6 cancer cell growth rather than cancer cell growth, as no normal control was available. Free radical formation as well as hydroxyl radical formation were reduced in the deoxyribose assay. In addition, cimetidine exhibits properties of binding to metals such as copper and iron. To maintain consistency in the experiments, a WHCO6 (Wits Human Carcinoma of the Oesophagus) cell line was used to investigate the effect of cimetidine in cancer. Neurodegeneration was induced in the rat brain using neurotoxins such as cyanide to investigate the relationship between cimetidine in AD. A decrease in cancer cell growth was accompanied by a concomitant decrease in the levels of free radicals and lipid peroxidation, suggesting that the growth-inhibitory effects of cimetidine on WHCO6 cancer cells in vitro may be due to free radical scavenging properties. This proposal was further strengthened by determination of free radical levels in the rat brain. After treatment with neurotoxins to induce neurodegeneration, the levels of free radicals in the rat brain suggest that addition of cimetidine reduces free radical levels in the rat brain in a dosedependent manner. Further experiments were done in an attempt to uncover the underlying mechanism by which cimetidine exhibits free radical scavenging properties. Metal binding studies were done using electrochemical, HPLC and UV/Vis studies. The results show that cimetidine binds iron and copper. These metals have been implicated in free radical production via the Fenton reaction. By binding with cimetidine the metals become unavailable to produce free radicals and hence cimetidine indirectly reduces the formation of free radicals. The final experiment was the determination of cimetidine as a hydroxyl radical scavenger in the deoxyribose assay. Cimetidine was shown to act as a potent hydroxyl radical scavenger, thereby confirming its activity as a free radical scavenger. In addition, cimetidine protects against damage to the deoxyribose sugar, a component of DNA. Whilst there are many theories that explain the therapeutic role of cimetidine in degenerative disease, the actual mechanism of the role of cimetidine is emphasized as a free radical scavenger. Regardless of the mechanism of action, cimetidine does inhibit tumour growth according to this study and also reduce free radical levels in neurodegeneration, which suggests a role for cimetidine as a possible additive in treatment of patients with such disease states. These findings have important clinical implications, and needs to be investigated further.
- Full Text:
- Date Issued: 2003
Confirmation of a slow symplasmic loading and unloading pathway in barley (Hordeum Vulgare L.) source and sink leaves
- Authors: Buwa, Lisa Valencia
- Date: 2003
- Subjects: Phloem , Plant translocation , Barley -- Metabolism
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4253 , http://hdl.handle.net/10962/d1007804
- Description: Visualization of the transport pathway in barley (Hordeum vulgare) leaves was carried out using a combination of aniline blue and a symplasmically transported fluorochrome, 5,6 carboxyfluorescein (5,6-CF). When applied to a source leaf, basipetal movement of 5,6-CF was observed after 3 h and the fluorochrome front was observed about 3-4cm away from the point of application. The fluorochrome was taken up into the symplasm of the mesophyll and was loaded into the bundle sheath cells and then subsequently the vascular parenchyma and finally into the sieve tubes. In sink leaves, acropetal movement was observed after 3 h and the fluorochrome had moved approximately 3 cm away from the point of application. Unloading of 5,6-CF occurred from all classes of longitudinal veins. Studies on solute retrieval showed that 5,6 CF-diacetate was transferred to xylem parenchyma where it was metabolized. 5,6-CF was then transferred from the xylem parenchyma to the vascular parenchyma cells, and it would appear that thick-walled sieve tubes were the first to show 5,6-CF labeling. Counterstaining with aniline blue demonstrates the presence of plasmodesmata and this suggests a potential symplasmic pathway from the mesophyll to the sieve tubes. Application of 5,6 CF-diacetate revealed a slow symplasmic pathway, which involved transfer of 5,6-CF, which was effected via plasmodesma.
- Full Text:
- Date Issued: 2003
- Authors: Buwa, Lisa Valencia
- Date: 2003
- Subjects: Phloem , Plant translocation , Barley -- Metabolism
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4253 , http://hdl.handle.net/10962/d1007804
- Description: Visualization of the transport pathway in barley (Hordeum vulgare) leaves was carried out using a combination of aniline blue and a symplasmically transported fluorochrome, 5,6 carboxyfluorescein (5,6-CF). When applied to a source leaf, basipetal movement of 5,6-CF was observed after 3 h and the fluorochrome front was observed about 3-4cm away from the point of application. The fluorochrome was taken up into the symplasm of the mesophyll and was loaded into the bundle sheath cells and then subsequently the vascular parenchyma and finally into the sieve tubes. In sink leaves, acropetal movement was observed after 3 h and the fluorochrome had moved approximately 3 cm away from the point of application. Unloading of 5,6-CF occurred from all classes of longitudinal veins. Studies on solute retrieval showed that 5,6 CF-diacetate was transferred to xylem parenchyma where it was metabolized. 5,6-CF was then transferred from the xylem parenchyma to the vascular parenchyma cells, and it would appear that thick-walled sieve tubes were the first to show 5,6-CF labeling. Counterstaining with aniline blue demonstrates the presence of plasmodesmata and this suggests a potential symplasmic pathway from the mesophyll to the sieve tubes. Application of 5,6 CF-diacetate revealed a slow symplasmic pathway, which involved transfer of 5,6-CF, which was effected via plasmodesma.
- Full Text:
- Date Issued: 2003
Cyclodepsipeptides from a Kenyan marine cyanobacterium
- Authors: Dzeha, Thomas Mwambire
- Date: 2003
- Subjects: Cyanobacteria , Stereochemistry , Natural products -- Kenya
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4303 , http://hdl.handle.net/10962/d1004961 , Cyanobacteria , Stereochemistry , Natural products -- Kenya
- Description: An examination of an organic extract of the cyanobacterium Lyngbya majuscula collected from Wasini Island off the southern Kenyan coast led to the isolation of the known cyclodepsipeptide antanapeptin A (7), recently isolated from a Madagascan collection of L. majuscula, and a new bioactive cyclodepsipeptide, homodolastatin 16 (42). Although L. majuscula is a common, pantropical cyanobacterium this study represents the first investigation of the natural product chemistry of a Kenyan population of L. majuscula. The structures of the two cyclodepsipeptides were determined from 2D NMR and mass spectrometry data. The L- stereochemistry of the proline, valine, and N-methylphenylalanine amino acids in 7 and the L – proline configuration in 42, was confirmed by Marfey’s HPLC method. Chiral GC was used to determine the absolute stereochemistry of the hydroxyisovaleric acid moiety in 7 and 42, the lactate residue in 42 and tentatively propose an L-stereochemistry for the Nmethylisoleucine amino acid in 42. Homodolastatin 16, a higher homologue of the potential anti-cancer agent, dolastatin 16, exhibited moderate activity against two oesophageal cancer cell lines.
- Full Text:
- Date Issued: 2003
- Authors: Dzeha, Thomas Mwambire
- Date: 2003
- Subjects: Cyanobacteria , Stereochemistry , Natural products -- Kenya
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4303 , http://hdl.handle.net/10962/d1004961 , Cyanobacteria , Stereochemistry , Natural products -- Kenya
- Description: An examination of an organic extract of the cyanobacterium Lyngbya majuscula collected from Wasini Island off the southern Kenyan coast led to the isolation of the known cyclodepsipeptide antanapeptin A (7), recently isolated from a Madagascan collection of L. majuscula, and a new bioactive cyclodepsipeptide, homodolastatin 16 (42). Although L. majuscula is a common, pantropical cyanobacterium this study represents the first investigation of the natural product chemistry of a Kenyan population of L. majuscula. The structures of the two cyclodepsipeptides were determined from 2D NMR and mass spectrometry data. The L- stereochemistry of the proline, valine, and N-methylphenylalanine amino acids in 7 and the L – proline configuration in 42, was confirmed by Marfey’s HPLC method. Chiral GC was used to determine the absolute stereochemistry of the hydroxyisovaleric acid moiety in 7 and 42, the lactate residue in 42 and tentatively propose an L-stereochemistry for the Nmethylisoleucine amino acid in 42. Homodolastatin 16, a higher homologue of the potential anti-cancer agent, dolastatin 16, exhibited moderate activity against two oesophageal cancer cell lines.
- Full Text:
- Date Issued: 2003
Development of a language policy in a rural school
- Authors: Fumba, Zamumzi Norman
- Date: 2003
- Subjects: Language policy -- South Africa Language and education -- South Africa Education, Rural -- South Africa -- Peddie Black people -- Education -- South Africa Native language and education -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1940 , http://hdl.handle.net/10962/d1007798
- Description: The study was undertaken to observe and participate in the process and development of a language policy for a rural secondary school in Peddie in the Eastern Cape. This was done in collaboration with parents, learners, and teachers. The researcher acted as a researcher, facilitator and learner in the process that Iead to the final product. Twenty four learners were selected from Grade 8 to Grade 10. These learners formed three focus groups. A questionnaire and lesson observation were used to establish what was taking place in the school with regard to language practices and preferences by learners, teachers and parents. Lesson observations were recorded by a tape recorder. Outcomes are that Xhosa is the dominant language to which the learners are exposed. They only have the exposure to 'chunks' of English in class and when they read magazines, newspapers and listening to radio and TV. Teachers code switch. This is supported by both learners and their parents. Parents want their children to improve performance by being taught in the medium of a language they understand well enough. The study shows different perceptions about the language that should be used as LOLT. Parents in the study favour English as LOLT, while parents in general favour Xhosa. This view is also held by both teachers and learners. At a conscious level when teachers and learners talk about the language to be used as LOLT, they favour English, but when they are faced with the reality of the class they are ambivalent, hence they code switch. The study finally reports on the divergent views of the parents, on one hand, and those of the teachers and the learners on the other hand. The divergence will be resolved in a workshop, part of the broader process of school language policy research, which is beyond the scope of the research reported in the thesis. The final product, in the form of the school language policy, will then be drafted for presentation to the School Governing Body (SGB) for ratification and writing up process.
- Full Text:
- Date Issued: 2003
- Authors: Fumba, Zamumzi Norman
- Date: 2003
- Subjects: Language policy -- South Africa Language and education -- South Africa Education, Rural -- South Africa -- Peddie Black people -- Education -- South Africa Native language and education -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1940 , http://hdl.handle.net/10962/d1007798
- Description: The study was undertaken to observe and participate in the process and development of a language policy for a rural secondary school in Peddie in the Eastern Cape. This was done in collaboration with parents, learners, and teachers. The researcher acted as a researcher, facilitator and learner in the process that Iead to the final product. Twenty four learners were selected from Grade 8 to Grade 10. These learners formed three focus groups. A questionnaire and lesson observation were used to establish what was taking place in the school with regard to language practices and preferences by learners, teachers and parents. Lesson observations were recorded by a tape recorder. Outcomes are that Xhosa is the dominant language to which the learners are exposed. They only have the exposure to 'chunks' of English in class and when they read magazines, newspapers and listening to radio and TV. Teachers code switch. This is supported by both learners and their parents. Parents want their children to improve performance by being taught in the medium of a language they understand well enough. The study shows different perceptions about the language that should be used as LOLT. Parents in the study favour English as LOLT, while parents in general favour Xhosa. This view is also held by both teachers and learners. At a conscious level when teachers and learners talk about the language to be used as LOLT, they favour English, but when they are faced with the reality of the class they are ambivalent, hence they code switch. The study finally reports on the divergent views of the parents, on one hand, and those of the teachers and the learners on the other hand. The divergence will be resolved in a workshop, part of the broader process of school language policy research, which is beyond the scope of the research reported in the thesis. The final product, in the form of the school language policy, will then be drafted for presentation to the School Governing Body (SGB) for ratification and writing up process.
- Full Text:
- Date Issued: 2003
Effects of small-scale water movement on the settlement and growth rates of the brown mussel Perna perna, on the south-east coast of South Africa
- Authors: Mathagu, Tendamudzimu Titus
- Date: 2003
- Subjects: Mussels -- South Africa , Perna -- South Africa , Perna -- Growth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5682 , http://hdl.handle.net/10962/d1005368 , Mussels -- South Africa , Perna -- South Africa , Perna -- Growth
- Description: The effects of small scale (cm) water movement on the settlement and growth rates of the brown mussel Perna perna were investigated on the south-east coast of South Africa (33°28′S, 27°10′E). L-shaped metal baffles attached to the substratum decreased the erosion rates of cement balls and it was concluded that the baffles decreased the water flow rate around cement balls. These L-shaped baffles were then used to decrease water flow rates around mussel patches and pot-scouring pads used as artificial substrata for the settlement of P.perna larvae. Anova indicated that settlement rate varied by date and site while decreased water flow rate significantly increased larval settlement (p<0.05), only on the site and day that had the overall highest number of settlers. Mussels in the low zone had significantly higher growth rates than those in the high zone. Decreased water flow rate significantly increased mussel growth rate in the lower zone (Anova, p<0.05), while it did not have a significant effect on the mussel in the high zone. Thus water flow manipulation increased growth rates in the zone, which already had high growth rate. It was concluded that small-scale (cm) water flow patterns have an effect on both Perna perna settlement and growth rates, but only under specific conditions. Larval settlement rate was significantly increased by water flow manipulation on the site and day that had the highest number of settlers. Growth rates were significantly increased by decreased water flow rate only in the low zone, where growth rates are the highest. Although water flow was manipulated in both zones its effect in the high zone was insignificant (Anova) compared to other factors affecting growth rates at this tidal level.
- Full Text:
- Date Issued: 2003
- Authors: Mathagu, Tendamudzimu Titus
- Date: 2003
- Subjects: Mussels -- South Africa , Perna -- South Africa , Perna -- Growth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5682 , http://hdl.handle.net/10962/d1005368 , Mussels -- South Africa , Perna -- South Africa , Perna -- Growth
- Description: The effects of small scale (cm) water movement on the settlement and growth rates of the brown mussel Perna perna were investigated on the south-east coast of South Africa (33°28′S, 27°10′E). L-shaped metal baffles attached to the substratum decreased the erosion rates of cement balls and it was concluded that the baffles decreased the water flow rate around cement balls. These L-shaped baffles were then used to decrease water flow rates around mussel patches and pot-scouring pads used as artificial substrata for the settlement of P.perna larvae. Anova indicated that settlement rate varied by date and site while decreased water flow rate significantly increased larval settlement (p<0.05), only on the site and day that had the overall highest number of settlers. Mussels in the low zone had significantly higher growth rates than those in the high zone. Decreased water flow rate significantly increased mussel growth rate in the lower zone (Anova, p<0.05), while it did not have a significant effect on the mussel in the high zone. Thus water flow manipulation increased growth rates in the zone, which already had high growth rate. It was concluded that small-scale (cm) water flow patterns have an effect on both Perna perna settlement and growth rates, but only under specific conditions. Larval settlement rate was significantly increased by water flow manipulation on the site and day that had the highest number of settlers. Growth rates were significantly increased by decreased water flow rate only in the low zone, where growth rates are the highest. Although water flow was manipulated in both zones its effect in the high zone was insignificant (Anova) compared to other factors affecting growth rates at this tidal level.
- Full Text:
- Date Issued: 2003
Exploring differences between organisational cultures in a company undergoing change
- Authors: Bowa, Mabvuto
- Date: 2003
- Subjects: Organizational change -- Africa , Corporate culture -- Africa , Management -- Africa , Organizational behavior -- Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3126 , http://hdl.handle.net/10962/d1006287 , Organizational change -- Africa , Corporate culture -- Africa , Management -- Africa , Organizational behavior -- Africa
- Description: Change is a common phenomena in business organisations today. The turbulent environment is exerting a significant influence on organisations to make continuous changes in their internal environment in an attempt to improve performance and achieve competitiveness in the marketplace. The human factors which confront organisations undergoing change have not been thoroughly investigated in Sub-Saharan Africa. The present study aimed at investigating human issues affecting the performance ofan organisation located in an Afiican country. Data was collected using semi-structured interviews and focus groups. Twenty interviews were conducted with employees randomly selected from all the levels of the company, namely attendant, operator, supervisory, middle and top management. Five focus groups were carried out with employees from different employee categories. Both sets of data were analysed using grounded theory. The findings showed that there were several problems in the company including insecurity, lack of opportunities for employee development, autocratic management style, lack of participation in decision making, substandard performance, ineffective human resources systems and lack of adaptation to technology. It was suggested that the problems resulted from the clash between organisational cultures in the company. At one level, there was a clash between the local workers' socialist organisational culture and the expatriates' capitalistic organisational culture. At a more deeper level, the clash appeared to be between the local employees' collectivistic sociocultural values and the expatriates' individualistic value system. These findings have significant implications for managing change in organisations with diverse cultures.
- Full Text:
- Date Issued: 2003
- Authors: Bowa, Mabvuto
- Date: 2003
- Subjects: Organizational change -- Africa , Corporate culture -- Africa , Management -- Africa , Organizational behavior -- Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3126 , http://hdl.handle.net/10962/d1006287 , Organizational change -- Africa , Corporate culture -- Africa , Management -- Africa , Organizational behavior -- Africa
- Description: Change is a common phenomena in business organisations today. The turbulent environment is exerting a significant influence on organisations to make continuous changes in their internal environment in an attempt to improve performance and achieve competitiveness in the marketplace. The human factors which confront organisations undergoing change have not been thoroughly investigated in Sub-Saharan Africa. The present study aimed at investigating human issues affecting the performance ofan organisation located in an Afiican country. Data was collected using semi-structured interviews and focus groups. Twenty interviews were conducted with employees randomly selected from all the levels of the company, namely attendant, operator, supervisory, middle and top management. Five focus groups were carried out with employees from different employee categories. Both sets of data were analysed using grounded theory. The findings showed that there were several problems in the company including insecurity, lack of opportunities for employee development, autocratic management style, lack of participation in decision making, substandard performance, ineffective human resources systems and lack of adaptation to technology. It was suggested that the problems resulted from the clash between organisational cultures in the company. At one level, there was a clash between the local workers' socialist organisational culture and the expatriates' capitalistic organisational culture. At a more deeper level, the clash appeared to be between the local employees' collectivistic sociocultural values and the expatriates' individualistic value system. These findings have significant implications for managing change in organisations with diverse cultures.
- Full Text:
- Date Issued: 2003
Finite element modelling of a magma chamber surrounded by country-rock, with particular reference to the groundwater flow in sections of different permeability
- Authors: Remsing, Carmen
- Date: 2003 , 2013-05-23
- Subjects: Magmas , Groundwater flow
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5508 , http://hdl.handle.net/10962/d1007537 , Magmas , Groundwater flow
- Description: This thesis presents results of two-dimensional finite element modelling of a magma chamber surrounded by country-rock containing a section of high permeability. The high permeability section in the country-rock simulates structure that is predominant in controlling the groundwater convection pattern and resulting mineral deposits. The models have analogies in nature: for instance the gold mines in the Massif Central of France, the Pogo mine in Alaska and the Pilgrim's Rest gold field in South Africa. This is a complicated coupled system involving fluid flow and heat transfer under extreme conditions. The magma in the chamber convects and as it cools the heat liberated causes convection in the groundwater contained in the surrounding country-rock. This convection in turn affects the rate of liberation of heat from the magma. The software used for the modelling, FLOTRAN, is the computational fluid dynamics component of the commercial ANSYS package. The results obtained describe in detail the flow pattern in the magma chamber, the country-rock and high permeability section thereof. During the cooling of the magma chamber the groundwater convects more vigorously in the high permeability section than elsewhere, and a convection cell is seen forming within this region. This provides a mechanism for hydrothermal formation of valuable mineral deposits in the structure near a magma chamber. It is found that the relationship between the velocity of the flow in the cell and the temperature of the magma chamber is well represented by a first order linear differential equation, providing a simple understanding of this process, , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2003
- Authors: Remsing, Carmen
- Date: 2003 , 2013-05-23
- Subjects: Magmas , Groundwater flow
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5508 , http://hdl.handle.net/10962/d1007537 , Magmas , Groundwater flow
- Description: This thesis presents results of two-dimensional finite element modelling of a magma chamber surrounded by country-rock containing a section of high permeability. The high permeability section in the country-rock simulates structure that is predominant in controlling the groundwater convection pattern and resulting mineral deposits. The models have analogies in nature: for instance the gold mines in the Massif Central of France, the Pogo mine in Alaska and the Pilgrim's Rest gold field in South Africa. This is a complicated coupled system involving fluid flow and heat transfer under extreme conditions. The magma in the chamber convects and as it cools the heat liberated causes convection in the groundwater contained in the surrounding country-rock. This convection in turn affects the rate of liberation of heat from the magma. The software used for the modelling, FLOTRAN, is the computational fluid dynamics component of the commercial ANSYS package. The results obtained describe in detail the flow pattern in the magma chamber, the country-rock and high permeability section thereof. During the cooling of the magma chamber the groundwater convects more vigorously in the high permeability section than elsewhere, and a convection cell is seen forming within this region. This provides a mechanism for hydrothermal formation of valuable mineral deposits in the structure near a magma chamber. It is found that the relationship between the velocity of the flow in the cell and the temperature of the magma chamber is well represented by a first order linear differential equation, providing a simple understanding of this process, , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2003
From labour reserve to investment opportunity: economic development planning in the Mbashe Local Municipal area in the Eastern Cape
- Authors: Reynolds, John Hunter
- Date: 2003
- Subjects: Economic development -- South Africa -- Eastern Cape , Community development -- South Africa -- Eastern Cape , South Africa -- Economic policy , Planning -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3353 , http://hdl.handle.net/10962/d1007490 , Economic development -- South Africa -- Eastern Cape , Community development -- South Africa -- Eastern Cape , South Africa -- Economic policy , Planning -- South Africa -- Eastern Cape
- Description: Planning for economic development at the local level has become increasingly important in many countries of the world. South Africa is no exception and has had the local focus entrenched through constitutional provisions for developmental local government. This developmental approach has been intimately linked to, and influenced by, the broader legislative, policy and planning context within which the development challenges of post-Apartheid South Africa have been addressed. It has also been implemented in a context of far-reaching transformation of public institutions aimed, in the final analysis, at the effective functioning of three spheres of government. In this thesis, the Mbashe Local Municipal area is used as a case study for an examination of the linkages between economic development planning at the local, provincial and national levels. It is not a case study in the sense that an in-depth analysis of practice is undertaken; it is used rather as a lens through which the economic development planning activities of the three spheres of government are viewed. Its value as a lens lies in its location in the former Transkei, which is characterised by high levels of unemployment and poverty and low levels of service infrastructure, and in its status as one of the newly demarcated local municipalities in South Africa. Mbashe is a pilot site of the Promotion of Rural Livelihoods Programme, which has been linked to the Eastern Cape Province's Integrated Sustainable Rural Development Programme. It also includes one of the nodes of the Wild Coast Spatial Development Initiative, which has, since 1998, been promoted as a vehicle for economic development in the former Transkei. Research comprised extensive documentary research, individual interviews with key role players in the Mbashe Local Municipality, the Promotion of Rural Livelihoods Programme and the Wild Coast Spatial Development Initiative, and a group interview with members of the Local Economic Development Sub-Committee of the Mbashe Local Municipal Council. An attempt was made to understand the complex layers of policy and planning frameworks that guide planning at the national and provincial levels and within which local level economic development is situated, and to explore the responses that have been forged by agents within the Mbashe area. Key in this endeavour has been the initiatives developed under the guidance of the Mbashe Local Economic Development Sub-Committee. It is argued that the severe resource constraints faced within Mbashe, combined with limited knowledge of and participation in larger planning and resource mobilisation frameworks, lock Local Economic Development within the top-down and investmentled approaches, rather than the more integrated approach that is promoted in terms of legislation and that is required if poverty is to be addressed successfully. The limitations on state fiscal expenditure and the market-led approach to service provision and economic development, implemented in terms of South Africa's macroeconomic framework, combined with limited synchronisation of planning cycles in which integrated development planning at the local level is privileged, leave little scope for endogenous economic development at local level. There is scope for creative engagement with the interlocking local, provincial, national and continental economies by actively shifting resources in support of integrated, endogenous approaches. Such approaches could serve as counter-narratives to the dominance of neoliberalism and allow for the establishment of local economic development practice that addresses the needs of the poor and that builds integrated local economies under the control of democratic institutions. It is only with such a shifting of approach that economic development within Mbashe will shift the structural conditions that lock it into economic dependence and poverty.
- Full Text:
- Date Issued: 2003
- Authors: Reynolds, John Hunter
- Date: 2003
- Subjects: Economic development -- South Africa -- Eastern Cape , Community development -- South Africa -- Eastern Cape , South Africa -- Economic policy , Planning -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3353 , http://hdl.handle.net/10962/d1007490 , Economic development -- South Africa -- Eastern Cape , Community development -- South Africa -- Eastern Cape , South Africa -- Economic policy , Planning -- South Africa -- Eastern Cape
- Description: Planning for economic development at the local level has become increasingly important in many countries of the world. South Africa is no exception and has had the local focus entrenched through constitutional provisions for developmental local government. This developmental approach has been intimately linked to, and influenced by, the broader legislative, policy and planning context within which the development challenges of post-Apartheid South Africa have been addressed. It has also been implemented in a context of far-reaching transformation of public institutions aimed, in the final analysis, at the effective functioning of three spheres of government. In this thesis, the Mbashe Local Municipal area is used as a case study for an examination of the linkages between economic development planning at the local, provincial and national levels. It is not a case study in the sense that an in-depth analysis of practice is undertaken; it is used rather as a lens through which the economic development planning activities of the three spheres of government are viewed. Its value as a lens lies in its location in the former Transkei, which is characterised by high levels of unemployment and poverty and low levels of service infrastructure, and in its status as one of the newly demarcated local municipalities in South Africa. Mbashe is a pilot site of the Promotion of Rural Livelihoods Programme, which has been linked to the Eastern Cape Province's Integrated Sustainable Rural Development Programme. It also includes one of the nodes of the Wild Coast Spatial Development Initiative, which has, since 1998, been promoted as a vehicle for economic development in the former Transkei. Research comprised extensive documentary research, individual interviews with key role players in the Mbashe Local Municipality, the Promotion of Rural Livelihoods Programme and the Wild Coast Spatial Development Initiative, and a group interview with members of the Local Economic Development Sub-Committee of the Mbashe Local Municipal Council. An attempt was made to understand the complex layers of policy and planning frameworks that guide planning at the national and provincial levels and within which local level economic development is situated, and to explore the responses that have been forged by agents within the Mbashe area. Key in this endeavour has been the initiatives developed under the guidance of the Mbashe Local Economic Development Sub-Committee. It is argued that the severe resource constraints faced within Mbashe, combined with limited knowledge of and participation in larger planning and resource mobilisation frameworks, lock Local Economic Development within the top-down and investmentled approaches, rather than the more integrated approach that is promoted in terms of legislation and that is required if poverty is to be addressed successfully. The limitations on state fiscal expenditure and the market-led approach to service provision and economic development, implemented in terms of South Africa's macroeconomic framework, combined with limited synchronisation of planning cycles in which integrated development planning at the local level is privileged, leave little scope for endogenous economic development at local level. There is scope for creative engagement with the interlocking local, provincial, national and continental economies by actively shifting resources in support of integrated, endogenous approaches. Such approaches could serve as counter-narratives to the dominance of neoliberalism and allow for the establishment of local economic development practice that addresses the needs of the poor and that builds integrated local economies under the control of democratic institutions. It is only with such a shifting of approach that economic development within Mbashe will shift the structural conditions that lock it into economic dependence and poverty.
- Full Text:
- Date Issued: 2003
Holding on or letting go?: the resolution of grief in relation to two Xhosa rituals in South Africa
- Authors: Van Heerden, Gary Paul
- Date: 2003
- Subjects: South Africa -- Social life and customs , Death -- Social aspects -- South Africa , Mourning customs -- South Africa , Bereavement -- Psychological aspects , Bereavement -- South Africa -- Cross-cultural studies , Death -- South Africa -- Cross-cultural studies , Xhosa (African people) -- Rites and ceremonies , Xhosa (African people) -- Social life and customs , Animal sacrifice -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3253 , http://hdl.handle.net/10962/d1016055
- Description: The dominant emphasis in Western models of bereavement is on the breaking of bonds with the deceased in order for healing to occur. Failure to let go often leads to a diagnosis of 'pathological grief'. This paper challenges the assumption that death invariably means that the bonds with the deceased have to be severed. Situating Western models of bereavement in a modernist context not only challenges the 'truth' claims of these models, but also facilitates a deconstruction of the elements that contribute to the emphasis on letting go. In contrast to these theories, two Xhosa rituals (umkhapho and umbuyiso) that seek to sustain the bond with the deceased person will be examined. Such rituals demonstrate that it is possible to both maintain the bond and for the bereaved person to move on with their lives. Despite different contexts, it will be argued that these Xhosa bereavement rituals have a contribution to make to Western models of bereavement and some implications for therapy will be explored.
- Full Text:
- Date Issued: 2003
- Authors: Van Heerden, Gary Paul
- Date: 2003
- Subjects: South Africa -- Social life and customs , Death -- Social aspects -- South Africa , Mourning customs -- South Africa , Bereavement -- Psychological aspects , Bereavement -- South Africa -- Cross-cultural studies , Death -- South Africa -- Cross-cultural studies , Xhosa (African people) -- Rites and ceremonies , Xhosa (African people) -- Social life and customs , Animal sacrifice -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3253 , http://hdl.handle.net/10962/d1016055
- Description: The dominant emphasis in Western models of bereavement is on the breaking of bonds with the deceased in order for healing to occur. Failure to let go often leads to a diagnosis of 'pathological grief'. This paper challenges the assumption that death invariably means that the bonds with the deceased have to be severed. Situating Western models of bereavement in a modernist context not only challenges the 'truth' claims of these models, but also facilitates a deconstruction of the elements that contribute to the emphasis on letting go. In contrast to these theories, two Xhosa rituals (umkhapho and umbuyiso) that seek to sustain the bond with the deceased person will be examined. Such rituals demonstrate that it is possible to both maintain the bond and for the bereaved person to move on with their lives. Despite different contexts, it will be argued that these Xhosa bereavement rituals have a contribution to make to Western models of bereavement and some implications for therapy will be explored.
- Full Text:
- Date Issued: 2003
In defence of moral objectivity
- Authors: McKaiser, Eusebius
- Date: 2003 , 2013-05-23
- Subjects: Ethics , Objectivity
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2740 , http://hdl.handle.net/10962/d1007599 , Ethics , Objectivity
- Description: This thesis examines the problem of moral objectivity, which is constituted by the ontological, epistemological and motivational challenges. It gradually develops an account of moral objectivity that has the dual function of dealing with the enemies of moral objectivity as well as giving a positive account of what moral objectivity is. It establishes these aims by arguing for the following theses. The first set of arguments show that relativist theories of ethics provide us with no forceful grounds for being sceptical about moral objectivity. The second set of arguments deepens the response to those who are sceptical about moral objectivity. It does so by showing in greater detail how rationality plays a substantive role in our practical deliberation, our notion of agency as well as our reactive attitudes. These arguments provide further reasons why we should have faith in the possibility of developing an adequate account of moral objectivity. The last set of arguments provides the positive account of moral objectivity. This positive account ends with the discussion of a paradigmatic moral fact that gives full expression (to the features of moral objectivity that have been articulated and defended.
- Full Text:
- Date Issued: 2003
- Authors: McKaiser, Eusebius
- Date: 2003 , 2013-05-23
- Subjects: Ethics , Objectivity
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2740 , http://hdl.handle.net/10962/d1007599 , Ethics , Objectivity
- Description: This thesis examines the problem of moral objectivity, which is constituted by the ontological, epistemological and motivational challenges. It gradually develops an account of moral objectivity that has the dual function of dealing with the enemies of moral objectivity as well as giving a positive account of what moral objectivity is. It establishes these aims by arguing for the following theses. The first set of arguments show that relativist theories of ethics provide us with no forceful grounds for being sceptical about moral objectivity. The second set of arguments deepens the response to those who are sceptical about moral objectivity. It does so by showing in greater detail how rationality plays a substantive role in our practical deliberation, our notion of agency as well as our reactive attitudes. These arguments provide further reasons why we should have faith in the possibility of developing an adequate account of moral objectivity. The last set of arguments provides the positive account of moral objectivity. This positive account ends with the discussion of a paradigmatic moral fact that gives full expression (to the features of moral objectivity that have been articulated and defended.
- Full Text:
- Date Issued: 2003
Intelligent design and biology
- Authors: Ramsden, Sean
- Date: 2003
- Subjects: Hume, David, 1711-1776 , Darwin, Charles, 1809-1882 , Paley, William, 1743-1805 , Dembski, William A., 1960- , Behe, Michael J., 1952- , Evolution (Biology) , Probabilities , Naturalism , Intelligent design (Teleology)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2739 , http://hdl.handle.net/10962/d1007561 , Hume, David, 1711-1776 , Darwin, Charles, 1809-1882 , Paley, William, 1743-1805 , Dembski, William A., 1960- , Behe, Michael J., 1952- , Evolution (Biology) , Probabilities , Naturalism , Intelligent design (Teleology)
- Description: The thesis is that contrary to the received popular wisdom, the combination of David Hume's sceptical enquiry and Charles Darwin's provision of an alternative theoretical framework to the then current paradigm of natural theology did not succeed in defeating the design argument. I argue that William Paley's work best represented the status quo in the philosophy of biology circa 1800 and that with the logical mechanisms provided us by William Dembski in his seminal work on probability, there is a strong argument for thr work of Michael Behe to stand in a similar position today to that of Paley two centuries ago. The argument runs as follows: In Sections 1 and 2 of Chapter 1 I introduce the issues. In Section 3 I argue that William Paley's exposition of the design argument was archetypical of the natural theology school and that given Hume's already published criticism of the argument, Paley for one did not feel the design argument to be done for. I further argue in Section 4 that Hume in fact did no such thing and that neither did he see himself as having done so, but that the design argument was weak rather than fallacious. In Section 5 I outline the demise of natural theology as the dominant school of thought in the philosophy of biology, ascribing this to the rise of Darwinism and subsequently neo-Darwinism. I argue that design arguments were again not defeated but went into abeyance with the rise of a new paradigm associated with Darwinism, namely methodological naturalism. In Chapter 2 I advance the project by a discussion of William Dembski's formulation of design inferences, demonstrating their value in both everyday and technical usage. This is stated in Section 1. In Sections 2 and 3 I discuss Dembski's treatment of probability, whilst in Section 4 I examine Dembski's tying of different levels of probability to different mechanisms of explanation used in explicating the world. Section 5 is my analysis of the logic of the formal statement of the design argument according to Dembski. In Section 6 I encapsulate objections to Dembski. I conclude the chapter (with Section 7) by claiming that Dembski forwards a coherent model of design inferences that can be used in demonstrating that there is little difference between the way that Paley came to his conclusions two centuries ago and how modem philosophers of biology (such as I take Michael Behe to be, albeit that by profession he is a scientist) come to theirs when offering design explanations. Inference to the best explanation is demonstrated as lying at the crux of design arguments. In Chapter 3 I draw together the work of Michael Behe and Paley, showing through the mechanism of Dembski's work that they are closely related in many respects and that neither position is to be lightly dismissed. Section 1 introduces this. In Section 2 I introduce Behe's concept of irreducible complexity in the light of (functional) explanation. Section 3 is a detailed analysis of irreducible complexity. Section 4 raises and covers objections to Behe with the general theme being that (neo-) Darwinians beg the question against him. In Section 4 I apply the Dembskian mechanic directly to Behe's work. I argue that Behe does not quite meet the Dembskian criteria he needs to in order for his argument to stand as anything other than defeasible. However, in Section 5 I conclude by arguing that this is exactly what we are to expect from Behe's and similar theories, even within competing paradigms, in the philosophy of biology, given that inference to the best explanation is the logical lever therein at work. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2003
- Authors: Ramsden, Sean
- Date: 2003
- Subjects: Hume, David, 1711-1776 , Darwin, Charles, 1809-1882 , Paley, William, 1743-1805 , Dembski, William A., 1960- , Behe, Michael J., 1952- , Evolution (Biology) , Probabilities , Naturalism , Intelligent design (Teleology)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2739 , http://hdl.handle.net/10962/d1007561 , Hume, David, 1711-1776 , Darwin, Charles, 1809-1882 , Paley, William, 1743-1805 , Dembski, William A., 1960- , Behe, Michael J., 1952- , Evolution (Biology) , Probabilities , Naturalism , Intelligent design (Teleology)
- Description: The thesis is that contrary to the received popular wisdom, the combination of David Hume's sceptical enquiry and Charles Darwin's provision of an alternative theoretical framework to the then current paradigm of natural theology did not succeed in defeating the design argument. I argue that William Paley's work best represented the status quo in the philosophy of biology circa 1800 and that with the logical mechanisms provided us by William Dembski in his seminal work on probability, there is a strong argument for thr work of Michael Behe to stand in a similar position today to that of Paley two centuries ago. The argument runs as follows: In Sections 1 and 2 of Chapter 1 I introduce the issues. In Section 3 I argue that William Paley's exposition of the design argument was archetypical of the natural theology school and that given Hume's already published criticism of the argument, Paley for one did not feel the design argument to be done for. I further argue in Section 4 that Hume in fact did no such thing and that neither did he see himself as having done so, but that the design argument was weak rather than fallacious. In Section 5 I outline the demise of natural theology as the dominant school of thought in the philosophy of biology, ascribing this to the rise of Darwinism and subsequently neo-Darwinism. I argue that design arguments were again not defeated but went into abeyance with the rise of a new paradigm associated with Darwinism, namely methodological naturalism. In Chapter 2 I advance the project by a discussion of William Dembski's formulation of design inferences, demonstrating their value in both everyday and technical usage. This is stated in Section 1. In Sections 2 and 3 I discuss Dembski's treatment of probability, whilst in Section 4 I examine Dembski's tying of different levels of probability to different mechanisms of explanation used in explicating the world. Section 5 is my analysis of the logic of the formal statement of the design argument according to Dembski. In Section 6 I encapsulate objections to Dembski. I conclude the chapter (with Section 7) by claiming that Dembski forwards a coherent model of design inferences that can be used in demonstrating that there is little difference between the way that Paley came to his conclusions two centuries ago and how modem philosophers of biology (such as I take Michael Behe to be, albeit that by profession he is a scientist) come to theirs when offering design explanations. Inference to the best explanation is demonstrated as lying at the crux of design arguments. In Chapter 3 I draw together the work of Michael Behe and Paley, showing through the mechanism of Dembski's work that they are closely related in many respects and that neither position is to be lightly dismissed. Section 1 introduces this. In Section 2 I introduce Behe's concept of irreducible complexity in the light of (functional) explanation. Section 3 is a detailed analysis of irreducible complexity. Section 4 raises and covers objections to Behe with the general theme being that (neo-) Darwinians beg the question against him. In Section 4 I apply the Dembskian mechanic directly to Behe's work. I argue that Behe does not quite meet the Dembskian criteria he needs to in order for his argument to stand as anything other than defeasible. However, in Section 5 I conclude by arguing that this is exactly what we are to expect from Behe's and similar theories, even within competing paradigms, in the philosophy of biology, given that inference to the best explanation is the logical lever therein at work. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2003
Investigation of the comparative cost-effectiveness of different strategies for the management of multidrug-resistant tuberculosis
- Authors: Rockcliffe, Nicole
- Date: 2003
- Subjects: Tuberculosis , Multidrug resistance , Tuberculosis -- Treatment
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3788 , http://hdl.handle.net/10962/d1003266 , Tuberculosis , Multidrug resistance , Tuberculosis -- Treatment
- Description: The tuberculosis epidemic is escalating in South Africa as well as globally. This escalation is exacerbated by the increasing prevalence of multidrug-resistant tuberculosis (MDRTB), which is defined by the World Health Organisation (WHO) as resistance of Mycobacteria to at least isoniazid and rifampicin. Multi-drug resistant tuberculosis is estimated to occur in 1-2% of newly diagnosed tuberculosis (TB) patients and in 4-8% of previously treated patients. MDRTB is both difficult and expensive to treat, costing up to 126 times that of drug-sensitive TB. Resource constrained countries such as South Africa often lack both the money and the infrastructure to treat this disease. The aim of this project was to determine whether the performance of a systematic review with subsequent economic modelling could influence the decision making process for policy makers. Data was gathered and an economic evaluation of MDRTB treatment was performed from the perspective of the South African Department of Health. Three treatment alternatives were identified: a protocol regimen of second line anti-tuberculosis agents, as recommended in the South African guidelines for MDRTB, an appropriate regimen designed for each patient according to the results of culture and drug susceptibility tests, and non-drug management. A decision-analysis model using DATA 3.0 by Treeage® was developed to estimate the costs of each alternative. Outcomes were measured in terms of cost alone as well as the ‘number of cases cured’ and the number of ‘years of life saved’ for patients dying, being cured or failing treatment. Drug, hospital and laboratory costs incurred using each alternative were included in the analysis. A sensitivity analysis was performed on all variables in order to identify threshold values that would change the outcome of the evaluation. Results of the decision analysis indicate that the individualised regimen was both the cheaper and more cost-effective regimen of the two active treatment options, and was estimated to cost R50 661 per case cured and R2 070 per year of life saved. The protocol regimen was estimated to cost R73 609 per case cured and R2 741 per year of life saved. The outcome of the decision analysis was sensitive to changes in some of the variables used to model the disease, particularly the daily cost of drugs, the length of time spent in hospital and the length of treatment received by those patients dying or failing treatment. This modelling exercise highlighted significant deficiencies in the quality of evidence on MDRTB management available to policy makers. Pragmatic choices based on operational and other logistic concerns may need to be reviewed when further information becomes available. A case can be made for the establishment of a national database of costing and efficacy information to guide future policy revisions of the South African MDRTB treatment programme, which is resource intensive and of only moderate efficacy. However, due to the widely disparate range of studies on which this evaluation was based, the outcome of the study may not be credible. In this case, the use of a systematic review with subsequent economic modelling could not validly influence policy-makers to change the decision that they made on the basis of drug availability.
- Full Text:
- Date Issued: 2003
- Authors: Rockcliffe, Nicole
- Date: 2003
- Subjects: Tuberculosis , Multidrug resistance , Tuberculosis -- Treatment
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3788 , http://hdl.handle.net/10962/d1003266 , Tuberculosis , Multidrug resistance , Tuberculosis -- Treatment
- Description: The tuberculosis epidemic is escalating in South Africa as well as globally. This escalation is exacerbated by the increasing prevalence of multidrug-resistant tuberculosis (MDRTB), which is defined by the World Health Organisation (WHO) as resistance of Mycobacteria to at least isoniazid and rifampicin. Multi-drug resistant tuberculosis is estimated to occur in 1-2% of newly diagnosed tuberculosis (TB) patients and in 4-8% of previously treated patients. MDRTB is both difficult and expensive to treat, costing up to 126 times that of drug-sensitive TB. Resource constrained countries such as South Africa often lack both the money and the infrastructure to treat this disease. The aim of this project was to determine whether the performance of a systematic review with subsequent economic modelling could influence the decision making process for policy makers. Data was gathered and an economic evaluation of MDRTB treatment was performed from the perspective of the South African Department of Health. Three treatment alternatives were identified: a protocol regimen of second line anti-tuberculosis agents, as recommended in the South African guidelines for MDRTB, an appropriate regimen designed for each patient according to the results of culture and drug susceptibility tests, and non-drug management. A decision-analysis model using DATA 3.0 by Treeage® was developed to estimate the costs of each alternative. Outcomes were measured in terms of cost alone as well as the ‘number of cases cured’ and the number of ‘years of life saved’ for patients dying, being cured or failing treatment. Drug, hospital and laboratory costs incurred using each alternative were included in the analysis. A sensitivity analysis was performed on all variables in order to identify threshold values that would change the outcome of the evaluation. Results of the decision analysis indicate that the individualised regimen was both the cheaper and more cost-effective regimen of the two active treatment options, and was estimated to cost R50 661 per case cured and R2 070 per year of life saved. The protocol regimen was estimated to cost R73 609 per case cured and R2 741 per year of life saved. The outcome of the decision analysis was sensitive to changes in some of the variables used to model the disease, particularly the daily cost of drugs, the length of time spent in hospital and the length of treatment received by those patients dying or failing treatment. This modelling exercise highlighted significant deficiencies in the quality of evidence on MDRTB management available to policy makers. Pragmatic choices based on operational and other logistic concerns may need to be reviewed when further information becomes available. A case can be made for the establishment of a national database of costing and efficacy information to guide future policy revisions of the South African MDRTB treatment programme, which is resource intensive and of only moderate efficacy. However, due to the widely disparate range of studies on which this evaluation was based, the outcome of the study may not be credible. In this case, the use of a systematic review with subsequent economic modelling could not validly influence policy-makers to change the decision that they made on the basis of drug availability.
- Full Text:
- Date Issued: 2003