Manure production and nutrient management in pasture-based dairy production systems
- Authors: Svinurai, Walter
- Date: 2010
- Subjects: Manures , Nitrogen -- Metabolism , Aloe -- South Africa , Pine bark , Pastures , Dairy cattle -- Nutrition , Dairy cattle -- Management , Dairy cattle -- Feeding and feeds
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11812 , http://hdl.handle.net/10353/475 , Manures , Nitrogen -- Metabolism , Aloe -- South Africa , Pine bark , Pastures , Dairy cattle -- Nutrition , Dairy cattle -- Management , Dairy cattle -- Feeding and feeds
- Description: Manure production and nutrient management in pasture-based dairy production systems by Walter Svinurai The effect of dietary treatments on nutrient excretion was determined and an attempt to improving the retention of excreted nitrogen in stored manure using Aloe ferox leaf gel (AFLG) and pine bark was conducted at a pasture-based dairy farm. The animal mass-balance method was used to determine nutrient excretion by cows fed on three dietary treatments, Lolium perrene-based treatment (LP), Lolium multiforium-based treatment (LM) and Lolium perenne- Trifolium repens -based treatment (LTF). In separate experiments, slurry from dairy cows fed LM was amended with AFLG and pine bark at concentrations of 25, 50, 75 and 100 g/l and stored under anaerobic conditions for 16 days. The highest and lowest excretions of N, P and K were observed in LM and LP treatments, respectively. Increasing dietary N improved K and N retention in milk and, consequently increased milk urea nitrogen (MUN) and N excretion (P < 0.05). The concentrations of AFLG affected N and P retention in manure (P < 0.05). The highest retention in total Kjeldahl nitrogen (TKN) of the initial was 42% AFLG at 25g/l inclusion rate. Ammonium nitrogen (AMN) concentration increased significantly due to the interactive effect of AFLG inclusion rate and time. Pine bark powder significantly improved N and P retention in manure at all concentrations. The retention in TKN was higher (P < 0.05) at 25g/l pine bark powder than other concentrations. The interaction effect of inclusion rate and time increased iii AMN (P < 0.05). Dietary treatments significantly affected nutrient excretion, and AFLG and pine bark considerably improved N retention in stored slurry. Findings from the filed trial suggest the need for more attention on managing dietary nutrients in the post-rainy and cool-dry season when growth of pasture influenced choice of dietary treatments that led to high nutrient excretion. Field simulation of the additives to determine their efficacy and environmental hazards was recommended.
- Full Text:
- Date Issued: 2010
- Authors: Svinurai, Walter
- Date: 2010
- Subjects: Manures , Nitrogen -- Metabolism , Aloe -- South Africa , Pine bark , Pastures , Dairy cattle -- Nutrition , Dairy cattle -- Management , Dairy cattle -- Feeding and feeds
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11812 , http://hdl.handle.net/10353/475 , Manures , Nitrogen -- Metabolism , Aloe -- South Africa , Pine bark , Pastures , Dairy cattle -- Nutrition , Dairy cattle -- Management , Dairy cattle -- Feeding and feeds
- Description: Manure production and nutrient management in pasture-based dairy production systems by Walter Svinurai The effect of dietary treatments on nutrient excretion was determined and an attempt to improving the retention of excreted nitrogen in stored manure using Aloe ferox leaf gel (AFLG) and pine bark was conducted at a pasture-based dairy farm. The animal mass-balance method was used to determine nutrient excretion by cows fed on three dietary treatments, Lolium perrene-based treatment (LP), Lolium multiforium-based treatment (LM) and Lolium perenne- Trifolium repens -based treatment (LTF). In separate experiments, slurry from dairy cows fed LM was amended with AFLG and pine bark at concentrations of 25, 50, 75 and 100 g/l and stored under anaerobic conditions for 16 days. The highest and lowest excretions of N, P and K were observed in LM and LP treatments, respectively. Increasing dietary N improved K and N retention in milk and, consequently increased milk urea nitrogen (MUN) and N excretion (P < 0.05). The concentrations of AFLG affected N and P retention in manure (P < 0.05). The highest retention in total Kjeldahl nitrogen (TKN) of the initial was 42% AFLG at 25g/l inclusion rate. Ammonium nitrogen (AMN) concentration increased significantly due to the interactive effect of AFLG inclusion rate and time. Pine bark powder significantly improved N and P retention in manure at all concentrations. The retention in TKN was higher (P < 0.05) at 25g/l pine bark powder than other concentrations. The interaction effect of inclusion rate and time increased iii AMN (P < 0.05). Dietary treatments significantly affected nutrient excretion, and AFLG and pine bark considerably improved N retention in stored slurry. Findings from the filed trial suggest the need for more attention on managing dietary nutrients in the post-rainy and cool-dry season when growth of pasture influenced choice of dietary treatments that led to high nutrient excretion. Field simulation of the additives to determine their efficacy and environmental hazards was recommended.
- Full Text:
- Date Issued: 2010
Maximization of power in randomized clinical trials using the minimization treatment allocation technique
- Authors: Marange, Chioneso Show
- Date: 2010
- Subjects: Clinical trials -- Statistical methods , Statistical hypothesis testing , Regression analysis , Logistic distribution , Estimation theory
- Language: English
- Type: Thesis , Masters , MSc (Biostatistics and Epidemiology)
- Identifier: vital:11777 , http://hdl.handle.net/10353/399 , Clinical trials -- Statistical methods , Statistical hypothesis testing , Regression analysis , Logistic distribution , Estimation theory
- Description: Generally the primary goal of randomized clinical trials (RCT) is to make comparisons among two or more treatments hence clinical investigators require the most appropriate treatment allocation procedure to yield reliable results regardless of whether the ultimate data suggest a clinically important difference between the treatments being studied. Although recommended by many researchers, the utilization of minimization has been seldom reported in randomized trials mainly because of the controversy surrounding the statistical efficiency in detecting treatment effect and its complexity in implementation. Methods: A SAS simulation code was designed for allocating patients into two different treatment groups. Categorical prognostic factors were used together with multi-level response variables and demonstration of how simulation of data can help to determine the power of the minimization technique was carried out using ordinal logistic regression models. Results: Several scenarios were simulated in this study. Within the selected scenarios, increasing the sample size significantly increased the power of detecting the treatment effect. This was contrary to the case when the probability of allocation was decreased. Power did not change when the probability of allocation given that the treatment groups are balanced was increased. The probability of allocation { } k P was seen to be the only one with a significant effect on treatment balance. Conclusion: Maximum power can be achieved with a sample of size 300 although a small sample of size 200 can be adequate to attain at least 80% power. In order to have maximum power, the probability of allocation should be fixed at 0.75 and set to 0.5 if the treatment groups are equally balanced.
- Full Text:
- Date Issued: 2010
- Authors: Marange, Chioneso Show
- Date: 2010
- Subjects: Clinical trials -- Statistical methods , Statistical hypothesis testing , Regression analysis , Logistic distribution , Estimation theory
- Language: English
- Type: Thesis , Masters , MSc (Biostatistics and Epidemiology)
- Identifier: vital:11777 , http://hdl.handle.net/10353/399 , Clinical trials -- Statistical methods , Statistical hypothesis testing , Regression analysis , Logistic distribution , Estimation theory
- Description: Generally the primary goal of randomized clinical trials (RCT) is to make comparisons among two or more treatments hence clinical investigators require the most appropriate treatment allocation procedure to yield reliable results regardless of whether the ultimate data suggest a clinically important difference between the treatments being studied. Although recommended by many researchers, the utilization of minimization has been seldom reported in randomized trials mainly because of the controversy surrounding the statistical efficiency in detecting treatment effect and its complexity in implementation. Methods: A SAS simulation code was designed for allocating patients into two different treatment groups. Categorical prognostic factors were used together with multi-level response variables and demonstration of how simulation of data can help to determine the power of the minimization technique was carried out using ordinal logistic regression models. Results: Several scenarios were simulated in this study. Within the selected scenarios, increasing the sample size significantly increased the power of detecting the treatment effect. This was contrary to the case when the probability of allocation was decreased. Power did not change when the probability of allocation given that the treatment groups are balanced was increased. The probability of allocation { } k P was seen to be the only one with a significant effect on treatment balance. Conclusion: Maximum power can be achieved with a sample of size 300 although a small sample of size 200 can be adequate to attain at least 80% power. In order to have maximum power, the probability of allocation should be fixed at 0.75 and set to 0.5 if the treatment groups are equally balanced.
- Full Text:
- Date Issued: 2010
Meaning in life and sense of coherence in HIV-positive adults
- Authors: Nolte, Coenraad B
- Date: 2010
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9857 , http://hdl.handle.net/10948/1562
- Description: Human Immunodeficiency Virus (HIV) infection is highly prevalent in South Africa and inevitably leads to an acute stage of the disease referred to as Acquired Immunodeficiency Syndrome (AIDS). Individual variations in the rate of HIV-disease progression are, amongst others, a function of the psychological reactions to an HIV-positive diagnosis and the prevalence of psychosocial stressors. This study was conducted in the context of the salutogenic paradigm and the existential psychological theory of Viktor Frankl. Sense of coherence is a key salutogenic concept and previous studies have suggested a positive correlation between the sense of coherence and the wellbeing of HIV-positive individuals. The objectives of this research were to explore and describe the search for meaning in life, the presence of meaning in life, the sense of coherence and the potential relationships among these concepts in HIV-positive adults. The research sample consisted of 62 participants recruited from an HIV wellness clinic in the Nelson Mandela Metropolitan area. Key findings included the following: Levels of search for meaning in life and presence of meaning in life were not found to be elevated or suppressed in the research sample. No significant relationship was found between the levels of search for meaning in life and presence of meaning in life. The level of sense of coherence of the sample was found to be lower than the level of sense of coherence obtained in previous studies from healthy, mixed populations in South Africa. A statistically significant relationship was found between the levels of presence of meaning in life and the sense of coherence. In conclusion it was proposed that presence of meaning in life is a fortifier of the sense of coherence.
- Full Text:
- Date Issued: 2010
- Authors: Nolte, Coenraad B
- Date: 2010
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9857 , http://hdl.handle.net/10948/1562
- Description: Human Immunodeficiency Virus (HIV) infection is highly prevalent in South Africa and inevitably leads to an acute stage of the disease referred to as Acquired Immunodeficiency Syndrome (AIDS). Individual variations in the rate of HIV-disease progression are, amongst others, a function of the psychological reactions to an HIV-positive diagnosis and the prevalence of psychosocial stressors. This study was conducted in the context of the salutogenic paradigm and the existential psychological theory of Viktor Frankl. Sense of coherence is a key salutogenic concept and previous studies have suggested a positive correlation between the sense of coherence and the wellbeing of HIV-positive individuals. The objectives of this research were to explore and describe the search for meaning in life, the presence of meaning in life, the sense of coherence and the potential relationships among these concepts in HIV-positive adults. The research sample consisted of 62 participants recruited from an HIV wellness clinic in the Nelson Mandela Metropolitan area. Key findings included the following: Levels of search for meaning in life and presence of meaning in life were not found to be elevated or suppressed in the research sample. No significant relationship was found between the levels of search for meaning in life and presence of meaning in life. The level of sense of coherence of the sample was found to be lower than the level of sense of coherence obtained in previous studies from healthy, mixed populations in South Africa. A statistically significant relationship was found between the levels of presence of meaning in life and the sense of coherence. In conclusion it was proposed that presence of meaning in life is a fortifier of the sense of coherence.
- Full Text:
- Date Issued: 2010
Media convergence : an analysis of consumer engagement
- Authors: Muwanga-Zake, Semeyi
- Date: 2010
- Subjects: Mass media , Journalism
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8612 , http://hdl.handle.net/10948/1557 , Mass media , Journalism
- Description: Media convergence has meant that the traditional separations between the various media industries, such as the internet, broadcasting and telephone networks are slowly collapsing due to the growing use and influence of digital electronics - in effect, morphing or transforming the media landscape. A fundamental change in today's media landscape has been the shift in control over media content, consumer consumption patterns as well as the manner and level at which consumers interact. Thus, the extent to which success is achieved now depends on a customer centric engagement strategy that can be implemented across converged platforms. This study considers the challenges posed by media convergence. It also investigates how organisations adjusted strategies to mitigate these challenges.
- Full Text:
- Date Issued: 2010
- Authors: Muwanga-Zake, Semeyi
- Date: 2010
- Subjects: Mass media , Journalism
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8612 , http://hdl.handle.net/10948/1557 , Mass media , Journalism
- Description: Media convergence has meant that the traditional separations between the various media industries, such as the internet, broadcasting and telephone networks are slowly collapsing due to the growing use and influence of digital electronics - in effect, morphing or transforming the media landscape. A fundamental change in today's media landscape has been the shift in control over media content, consumer consumption patterns as well as the manner and level at which consumers interact. Thus, the extent to which success is achieved now depends on a customer centric engagement strategy that can be implemented across converged platforms. This study considers the challenges posed by media convergence. It also investigates how organisations adjusted strategies to mitigate these challenges.
- Full Text:
- Date Issued: 2010
Mediating factors in the relationship between childhood sexual abuse and HIV Sexual risk behaviour among men who have sex with men
- Authors: Heusser, Shelly Lucien
- Date: 2010
- Subjects: Adult child sexual abuse victims -- Sexual behavior -- South Africa , Sexually transmitted diseases -- Psychological aspects , Risk-taking (Psychology)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9873 , http://hdl.handle.net/10948/1398 , Adult child sexual abuse victims -- Sexual behavior -- South Africa , Sexually transmitted diseases -- Psychological aspects , Risk-taking (Psychology)
- Description: Previous studies have indicated an association between childhood sexual abuse (CSA) and an increased risk of engaging in unsafe behaviours during adulthood, including risky sexual practices. This study examined the relationship between CSA and adult HIV sexual risk behaviour among a sample of South African men who have sex with men (MSM). Potential pathological long-term mental health outcomes of CSA, including dissociation, sex-related substance abuse, depression, sexual compulsivity, impaired interpersonal communication, and over-reliance on submissive sexual scripts, were treated as variables mediating the relationship between CSA and sexual risk behaviour. Men frequenting a gay internet dating site were randomly selected to complete an electronic version of the anonymous survey. Results indicate that one-fourth of participants reported a history of CSA. Men with a history of unwanted sexual activity during childhood were more likely to report recreational substance abuse, sex-related substance abuse, sexual compulsivity, and adult revictimisation experiences. Men who were abused were also more likely to engage in unprotected anal intercourse compared to those who were not abused. Mediation analyses revealed that MSM who are survivors of CSA are particularly susceptible to drug abuse, sex-related drug abuse, and sexual compulsivity, and these sequelae in turn predict higher reported numbers of male sexual partners. The current data suggest that CSA is widespread among men at high risk for HIV infection, and that it may have a devastating influence on the quality of life and health risk behaviour of these men. These results also highlight the importance of mental health services and new approaches in HIV prevention for MSM who have been sexually abused as children. Further research is needed into the contextual factors of the childhood abuse experience which account for the variability in longterm negative mental health outcomes of CSA survivors.
- Full Text:
- Date Issued: 2010
- Authors: Heusser, Shelly Lucien
- Date: 2010
- Subjects: Adult child sexual abuse victims -- Sexual behavior -- South Africa , Sexually transmitted diseases -- Psychological aspects , Risk-taking (Psychology)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9873 , http://hdl.handle.net/10948/1398 , Adult child sexual abuse victims -- Sexual behavior -- South Africa , Sexually transmitted diseases -- Psychological aspects , Risk-taking (Psychology)
- Description: Previous studies have indicated an association between childhood sexual abuse (CSA) and an increased risk of engaging in unsafe behaviours during adulthood, including risky sexual practices. This study examined the relationship between CSA and adult HIV sexual risk behaviour among a sample of South African men who have sex with men (MSM). Potential pathological long-term mental health outcomes of CSA, including dissociation, sex-related substance abuse, depression, sexual compulsivity, impaired interpersonal communication, and over-reliance on submissive sexual scripts, were treated as variables mediating the relationship between CSA and sexual risk behaviour. Men frequenting a gay internet dating site were randomly selected to complete an electronic version of the anonymous survey. Results indicate that one-fourth of participants reported a history of CSA. Men with a history of unwanted sexual activity during childhood were more likely to report recreational substance abuse, sex-related substance abuse, sexual compulsivity, and adult revictimisation experiences. Men who were abused were also more likely to engage in unprotected anal intercourse compared to those who were not abused. Mediation analyses revealed that MSM who are survivors of CSA are particularly susceptible to drug abuse, sex-related drug abuse, and sexual compulsivity, and these sequelae in turn predict higher reported numbers of male sexual partners. The current data suggest that CSA is widespread among men at high risk for HIV infection, and that it may have a devastating influence on the quality of life and health risk behaviour of these men. These results also highlight the importance of mental health services and new approaches in HIV prevention for MSM who have been sexually abused as children. Further research is needed into the contextual factors of the childhood abuse experience which account for the variability in longterm negative mental health outcomes of CSA survivors.
- Full Text:
- Date Issued: 2010
Mental health care practitioners' perceptions of mental illness within the isiXhosa cultural context
- Authors: Lombo, Nocawa Philomina
- Date: 2010
- Subjects: Mental illness -- South Africa , Mental health personnel , Psychiatric nursing , Xhosa (African people) -- Psychology , Xhosa (African people) -- Social life and customs
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9997 , http://hdl.handle.net/10948/1179 , Mental illness -- South Africa , Mental health personnel , Psychiatric nursing , Xhosa (African people) -- Psychology , Xhosa (African people) -- Social life and customs
- Description: This study sought to explore the perceptions of mental health care practitioners’ perceptions on mental illness within the isiXhosa cultural context. A qualitative exploratory descriptive and contextual design was used for the study. A non-probability purposive sampling method was used to select eight participants from Komani Hospital in Queenstown. Data was collected through semi-structured interviews. The services of an Independent Interviewer were used to avoid any bias as interviews took place where the researcher is employed. All interviews were transcribed verbatim and the data collected was analyzed according to Tesch’s eight steps of data analysis as described in Cresswell (1994:155). The researcher utilized services of an Independent Coder who verified the identified major themes. Four major themes emerged from the analysis of the interview: Mental health care practitioner’s perceptions of mental illness, perception of the causes of mental illness within the isiXhosa cultural context, mental health care practitioners’ views in the management and treatment of mental illness and suggestions put forward to improve the services to mental health care users. The major findings of this study were the lack of knowledge of culture of mental health care users. It is recommended that it would be proper if there could be co-operation between mental health care practitioners and traditional healers by working together as a team.
- Full Text:
- Date Issued: 2010
Mental health care practitioners' perceptions of mental illness within the isiXhosa cultural context
- Authors: Lombo, Nocawa Philomina
- Date: 2010
- Subjects: Mental illness -- South Africa , Mental health personnel , Psychiatric nursing , Xhosa (African people) -- Psychology , Xhosa (African people) -- Social life and customs
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9997 , http://hdl.handle.net/10948/1179 , Mental illness -- South Africa , Mental health personnel , Psychiatric nursing , Xhosa (African people) -- Psychology , Xhosa (African people) -- Social life and customs
- Description: This study sought to explore the perceptions of mental health care practitioners’ perceptions on mental illness within the isiXhosa cultural context. A qualitative exploratory descriptive and contextual design was used for the study. A non-probability purposive sampling method was used to select eight participants from Komani Hospital in Queenstown. Data was collected through semi-structured interviews. The services of an Independent Interviewer were used to avoid any bias as interviews took place where the researcher is employed. All interviews were transcribed verbatim and the data collected was analyzed according to Tesch’s eight steps of data analysis as described in Cresswell (1994:155). The researcher utilized services of an Independent Coder who verified the identified major themes. Four major themes emerged from the analysis of the interview: Mental health care practitioner’s perceptions of mental illness, perception of the causes of mental illness within the isiXhosa cultural context, mental health care practitioners’ views in the management and treatment of mental illness and suggestions put forward to improve the services to mental health care users. The major findings of this study were the lack of knowledge of culture of mental health care users. It is recommended that it would be proper if there could be co-operation between mental health care practitioners and traditional healers by working together as a team.
- Full Text:
- Date Issued: 2010
Microalgal biomass and distribution in the Mngazi and Mngazana Estuaries
- Ngesi, Hlekani Ntombizakithi
- Authors: Ngesi, Hlekani Ntombizakithi
- Date: 2010
- Subjects: Microalgae -- South Africa -- Mngazi Estuary , Algae -- South Africa -- Mngazi Estuary , Algae -- South Africa -- Mngazana Estuary , Estuarine ecology -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10610 , http://hdl.handle.net/10948/1591 , Microalgae -- South Africa -- Mngazi Estuary , Algae -- South Africa -- Mngazi Estuary , Algae -- South Africa -- Mngazana Estuary , Estuarine ecology -- South Africa
- Description: The present study was undertaken in the temporarily open/closed Mngazi and permanently open Mngazana estuaries, located on the subtropical east coast of South Africa. The results from this research will assist decision makers in the freshwater management of these systems. Intertidal and subtidal benthic chlorophyll a concentrations, water column chlorophyll a, nutrients and several physico-chemical parameters were measured between June 2002 and November 2003. The objective of this study was to determine if the presence of freshwater in the estuaries had an effect on the microalgae of both estuaries. Five sites were sampled in the Mngazi Estuary and 14 sites were sampled in the Mngazana Estuary. The average water column chlorophyll a was significantly higher (p<0.05) in the Mngazana Estuary (surface 7.8 ± 0.7 μg.l-1, bottom 6.4 ± 0.7 μg.l-1) compared to the Mngazi Estuary (surface 4.9 ± 1.2 μg.l-1, bottom 7.3 ± 1.5 μg.l-1). There was no evidence of an REI (river-estuary interface) zone in areas where the water column chlorophyll a concentrations were high even during open mouth conditions in the Mngazi Estuary. The REI is that area where salinity is less than 10 ppt and is characterized by high water column productivity. Even though both systems received some freshwater during the summer periods, this was not enough to stimulate phytoplankton growth and nutrient availability seems to be the major factor limiting phytoplankton in these systems. Flagellates and diatoms were the dominant phytoplankton groups in both estuaries during the entire sampling session. The relative abundance of the different phytoplankton groups did not show differences between sites. The relative abundance of flagellates was in most cases greater than 60% and diatoms made up the remainder. The average benthic chlorophyll a was higher in the Mngazana Estuary (intertidal 24 ± 6 μg.g-1 subtidal 15.2 ± 3 μg.g-1) compared to the Mngazi Estuary (intertidal 15.3 ± 4.3 μg.g-1 subtidal 5.4 ± 1.6 μg.g-1). Regions with high benthic chlorophyll a concentrations had high sediment organic content. Sediment organic content was higher in the Mngazana Estuary (1 percent - 8 percent) compared to the Mngazi Estuary (4 percent – 6.8 percent). The sites situated on the Main Channel had on average significantly higher (p<0.05) benthic chlorophyll a biomass compared to Creek 1 and Creek 2 in the Mngazana Estuary. Peaks in benthic chlorophyll a concentrations occurred in the intertidal sediments in Creek 1 (50.4 ± 13.4 μg.g-1) and Creek 2 (57.4 ± 1.4 μg.g-1) in the Mngazana Estuary, the peaks occurred in winter during a period of low freshwater inflow into the estuary. Microphytobenthic biomass measured in the Mngazi Estuary is among the lowest values reported in the literature for temporarily open/closed estuaries. Statistical 4 analysis showed no significant difference between benthic chlorophyll a during the different mouth conditions and sampling sessions in the Mngazi Estuary. Microalgal responses in the Mngazana Estuary were similar to those observed in other permanently open marine dominated estuaries. In the temporarily open/closed Mngazi Estuary microalgal characteristics were different to that of other temporarily open/closed estuaries probably because the estuary was only sampled in the open and semi-closed state.
- Full Text:
- Date Issued: 2010
- Authors: Ngesi, Hlekani Ntombizakithi
- Date: 2010
- Subjects: Microalgae -- South Africa -- Mngazi Estuary , Algae -- South Africa -- Mngazi Estuary , Algae -- South Africa -- Mngazana Estuary , Estuarine ecology -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10610 , http://hdl.handle.net/10948/1591 , Microalgae -- South Africa -- Mngazi Estuary , Algae -- South Africa -- Mngazi Estuary , Algae -- South Africa -- Mngazana Estuary , Estuarine ecology -- South Africa
- Description: The present study was undertaken in the temporarily open/closed Mngazi and permanently open Mngazana estuaries, located on the subtropical east coast of South Africa. The results from this research will assist decision makers in the freshwater management of these systems. Intertidal and subtidal benthic chlorophyll a concentrations, water column chlorophyll a, nutrients and several physico-chemical parameters were measured between June 2002 and November 2003. The objective of this study was to determine if the presence of freshwater in the estuaries had an effect on the microalgae of both estuaries. Five sites were sampled in the Mngazi Estuary and 14 sites were sampled in the Mngazana Estuary. The average water column chlorophyll a was significantly higher (p<0.05) in the Mngazana Estuary (surface 7.8 ± 0.7 μg.l-1, bottom 6.4 ± 0.7 μg.l-1) compared to the Mngazi Estuary (surface 4.9 ± 1.2 μg.l-1, bottom 7.3 ± 1.5 μg.l-1). There was no evidence of an REI (river-estuary interface) zone in areas where the water column chlorophyll a concentrations were high even during open mouth conditions in the Mngazi Estuary. The REI is that area where salinity is less than 10 ppt and is characterized by high water column productivity. Even though both systems received some freshwater during the summer periods, this was not enough to stimulate phytoplankton growth and nutrient availability seems to be the major factor limiting phytoplankton in these systems. Flagellates and diatoms were the dominant phytoplankton groups in both estuaries during the entire sampling session. The relative abundance of the different phytoplankton groups did not show differences between sites. The relative abundance of flagellates was in most cases greater than 60% and diatoms made up the remainder. The average benthic chlorophyll a was higher in the Mngazana Estuary (intertidal 24 ± 6 μg.g-1 subtidal 15.2 ± 3 μg.g-1) compared to the Mngazi Estuary (intertidal 15.3 ± 4.3 μg.g-1 subtidal 5.4 ± 1.6 μg.g-1). Regions with high benthic chlorophyll a concentrations had high sediment organic content. Sediment organic content was higher in the Mngazana Estuary (1 percent - 8 percent) compared to the Mngazi Estuary (4 percent – 6.8 percent). The sites situated on the Main Channel had on average significantly higher (p<0.05) benthic chlorophyll a biomass compared to Creek 1 and Creek 2 in the Mngazana Estuary. Peaks in benthic chlorophyll a concentrations occurred in the intertidal sediments in Creek 1 (50.4 ± 13.4 μg.g-1) and Creek 2 (57.4 ± 1.4 μg.g-1) in the Mngazana Estuary, the peaks occurred in winter during a period of low freshwater inflow into the estuary. Microphytobenthic biomass measured in the Mngazi Estuary is among the lowest values reported in the literature for temporarily open/closed estuaries. Statistical 4 analysis showed no significant difference between benthic chlorophyll a during the different mouth conditions and sampling sessions in the Mngazi Estuary. Microalgal responses in the Mngazana Estuary were similar to those observed in other permanently open marine dominated estuaries. In the temporarily open/closed Mngazi Estuary microalgal characteristics were different to that of other temporarily open/closed estuaries probably because the estuary was only sampled in the open and semi-closed state.
- Full Text:
- Date Issued: 2010
Microbial ecology of the Buffalo River in response to water quality changes
- Authors: Zuma, Bongumusa Msizi
- Date: 2010
- Subjects: Water quality -- South Africa -- Buffalo River (Eastern Cape) , Microbial ecology -- South Africa -- Buffalo River (Eastern Cape) , River Health Programme (South Africa)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:6038 , http://hdl.handle.net/10962/d1006182 , Water quality -- South Africa -- Buffalo River (Eastern Cape) , Microbial ecology -- South Africa -- Buffalo River (Eastern Cape) , River Health Programme (South Africa)
- Description: South Africa’s freshwater quality and quantity is declining and consequently impacting on the ecological health of these ecosystems, due to increased agricultural, urban and industrial developments. The River Health Programme (RHP) was designed for monitoring and assessing the ecological health of freshwater ecosystems in South Africa, in order to effectively manage these aquatic resources. The RHP utilises biological indicators such as in-stream biota as a structured and sensitive tool for assessing ecosystem health. Although the RHP has been widely implemented across South Africa, no attempts have been made to explore microbial ecology as a tool that could be included as one of the RHP indices. This study used selected microbial responses and water physico-chemical parameters to assess the current water quality status of the Buffalo River. This study showed that water quality impairments compounded in the urban regions of King William’s Town and Zwelitsha and also downstream of the Bridle Drift Dam. The results also showed that the lower and the upper catchments of the Buffalo River were not significantly different in terms of water physico-chemistry and microbiology, as indicated by low stress levels of an NMDS plot. Though similarities were recorded between impacted and reference sites, the results strongly showed that known impacted sites recorded the poorest water physico-chemistry, including the Yellowwoods River. However, the Laing Dam provided a buffer effect on contributions of the Yellowwoods River into the Buffalo River. Multivariate analysis showed that microbial cell counts were not influenced by water physico-chemical changes, whilst microbial activity from the water and biofilm habitats showed significant correlation levels to water physico-chemical changes. This study demonstrated that further investigations towards exploitation of microbial activity responses to water physico-chemical quality changes should be channelled towards the development of microbiological assessment index for inclusion in the RHP.
- Full Text:
- Date Issued: 2010
- Authors: Zuma, Bongumusa Msizi
- Date: 2010
- Subjects: Water quality -- South Africa -- Buffalo River (Eastern Cape) , Microbial ecology -- South Africa -- Buffalo River (Eastern Cape) , River Health Programme (South Africa)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:6038 , http://hdl.handle.net/10962/d1006182 , Water quality -- South Africa -- Buffalo River (Eastern Cape) , Microbial ecology -- South Africa -- Buffalo River (Eastern Cape) , River Health Programme (South Africa)
- Description: South Africa’s freshwater quality and quantity is declining and consequently impacting on the ecological health of these ecosystems, due to increased agricultural, urban and industrial developments. The River Health Programme (RHP) was designed for monitoring and assessing the ecological health of freshwater ecosystems in South Africa, in order to effectively manage these aquatic resources. The RHP utilises biological indicators such as in-stream biota as a structured and sensitive tool for assessing ecosystem health. Although the RHP has been widely implemented across South Africa, no attempts have been made to explore microbial ecology as a tool that could be included as one of the RHP indices. This study used selected microbial responses and water physico-chemical parameters to assess the current water quality status of the Buffalo River. This study showed that water quality impairments compounded in the urban regions of King William’s Town and Zwelitsha and also downstream of the Bridle Drift Dam. The results also showed that the lower and the upper catchments of the Buffalo River were not significantly different in terms of water physico-chemistry and microbiology, as indicated by low stress levels of an NMDS plot. Though similarities were recorded between impacted and reference sites, the results strongly showed that known impacted sites recorded the poorest water physico-chemistry, including the Yellowwoods River. However, the Laing Dam provided a buffer effect on contributions of the Yellowwoods River into the Buffalo River. Multivariate analysis showed that microbial cell counts were not influenced by water physico-chemical changes, whilst microbial activity from the water and biofilm habitats showed significant correlation levels to water physico-chemical changes. This study demonstrated that further investigations towards exploitation of microbial activity responses to water physico-chemical quality changes should be channelled towards the development of microbiological assessment index for inclusion in the RHP.
- Full Text:
- Date Issued: 2010
Modeling of arsenic removal from aqueous media using selected coagulants
- Authors: Majavu, Avela
- Date: 2010
- Subjects: Arsenic wastes , Water -- Purification -- Arsenic removal , Coagulation
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10426 , http://hdl.handle.net/10948/d1017100
- Description: The waste water from the industrial production of the herbicide monosodium methyl arsenate was treated using coagulation. The coagulation process as developed in this research proved to be suitable for arsenic removal in aqueous media using chromium (III), calcium (II), and combination of calcium (II) and chromium (III), and magnesium (II). The results obtained suggest that the coagulation process can be used for the treatment of the waste water from the monosodium methyl arsenate production. Response surface methodology was used to study the effects of the various parameters, namely pH, mole ratios (Cr:As, Ca:As, and Mg:As), concentration of flocculent and initial arsenic concentration. To optimize the process conditions for the maximum removal of arsenic. Central composite and factorial designs were used to study the effects of these variables and to predict the effect of each. ANOVA was used to identify those factors which had significant effects on model quality and performance. The initial arsenic concentration appeared to be the only significant factor. These models were statistically tested and verified by confirmation experiments.
- Full Text:
- Date Issued: 2010
- Authors: Majavu, Avela
- Date: 2010
- Subjects: Arsenic wastes , Water -- Purification -- Arsenic removal , Coagulation
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10426 , http://hdl.handle.net/10948/d1017100
- Description: The waste water from the industrial production of the herbicide monosodium methyl arsenate was treated using coagulation. The coagulation process as developed in this research proved to be suitable for arsenic removal in aqueous media using chromium (III), calcium (II), and combination of calcium (II) and chromium (III), and magnesium (II). The results obtained suggest that the coagulation process can be used for the treatment of the waste water from the monosodium methyl arsenate production. Response surface methodology was used to study the effects of the various parameters, namely pH, mole ratios (Cr:As, Ca:As, and Mg:As), concentration of flocculent and initial arsenic concentration. To optimize the process conditions for the maximum removal of arsenic. Central composite and factorial designs were used to study the effects of these variables and to predict the effect of each. ANOVA was used to identify those factors which had significant effects on model quality and performance. The initial arsenic concentration appeared to be the only significant factor. These models were statistically tested and verified by confirmation experiments.
- Full Text:
- Date Issued: 2010
Modelling and control of combustion in a high velocity air flame (HVAF) thermal spraying process
- Authors: Barth, Dominic
- Date: 2010
- Subjects: Metal spraying , Combustion
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9644 , http://hdl.handle.net/10948/1266 , Metal spraying , Combustion
- Description: Thermal spraying is a technology, which is used for coating of components and structures in order to achieve certain tribological characteristics, or for protection against corrosion, excessive temperature and wear. Within thermal spray, there are processes, which utilise combustion of liquid fuel to obtain high velocities flows providing, therefore, good adhesion of coating materials to substrates. These include High Velocity Oxygen Flame (HVOF) and High Velocity Air Flame (HVAF) process, of which the former one is widely used as it has been developed for at least two decades, while HVAF is less common. However, some studies indicate that HVAF has a number of advantages over HVOF, including the economic benefits. The thermal spray gun, based on the HVAF process, has been developed before, but the system was controlled manually. Therefore, there is a need to develop a fully automated controller of an HVAF thermal spray system. Process control of thermal spraying is highly complex as it involves simultaneous control of a number of processes, including; ignition process, combustion process, spraying material melting, as well as control and monitoring of auxiliary equipment. This paper presents the development of a control system for an HVAF thermal spray system, based on a Microchip PIC microcontroller. The designed control system was applied for controlling of thermal spraying of carbides powders, and provided a reliable ignition and stable combustion process, powder feeding and all other functions of control.
- Full Text:
- Date Issued: 2010
- Authors: Barth, Dominic
- Date: 2010
- Subjects: Metal spraying , Combustion
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9644 , http://hdl.handle.net/10948/1266 , Metal spraying , Combustion
- Description: Thermal spraying is a technology, which is used for coating of components and structures in order to achieve certain tribological characteristics, or for protection against corrosion, excessive temperature and wear. Within thermal spray, there are processes, which utilise combustion of liquid fuel to obtain high velocities flows providing, therefore, good adhesion of coating materials to substrates. These include High Velocity Oxygen Flame (HVOF) and High Velocity Air Flame (HVAF) process, of which the former one is widely used as it has been developed for at least two decades, while HVAF is less common. However, some studies indicate that HVAF has a number of advantages over HVOF, including the economic benefits. The thermal spray gun, based on the HVAF process, has been developed before, but the system was controlled manually. Therefore, there is a need to develop a fully automated controller of an HVAF thermal spray system. Process control of thermal spraying is highly complex as it involves simultaneous control of a number of processes, including; ignition process, combustion process, spraying material melting, as well as control and monitoring of auxiliary equipment. This paper presents the development of a control system for an HVAF thermal spray system, based on a Microchip PIC microcontroller. The designed control system was applied for controlling of thermal spraying of carbides powders, and provided a reliable ignition and stable combustion process, powder feeding and all other functions of control.
- Full Text:
- Date Issued: 2010
Motivation and complexity : an exploration of a complexity approach in employee motivation with specific focus on a Lacanian model of desire
- Authors: Botha, Anton Ivan
- Date: 2010
- Subjects: Employee motivation , Employee morale , Incentive awards
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:9400 , http://hdl.handle.net/10948/1232 , Employee motivation , Employee morale , Incentive awards
- Description: Since employee motivation contributes to overall organisational success, reliable motivation theory should inform management and reward practices. Yet, motivation theory is currently in a state of paralysis, with no constructive theorising taking place. Analysis of its methodological presuppositions reveals that it relies on out-dated binary thinking, prioritising, e.g. either a ‘machine-like’ (body driven) or ‘god-like’ (rationally driven) understanding of humanity. In this study it is argued that the revival of motivation theory requires a paradigmatic shift towards a complexity methodology because human motivation was found to be a complex system and must be theorised accordingly. It was found that McAdams’ theory of personality which brought together personality traits, conditioning, and motives could form the basis of a complex theory of motivation. On this basis, a complex model was developed which incorporated elements of existing motivational theories. This model proposed that drives, which motivate behaviour, are a combination of instincts, needs, and desires, mediated by personality traits, rational processing, and conditioning. All of these interconnected elements, as well as biological and environmental conditions, have an impact on, and are influenced by one another. For the purposes of understanding employee motivation the element of desire was isolated as a potential means to value segment employees. A Lacanian theory was utilised to elaborate on the element of desire. This theory postulated that individuals tend to display a dominance is one of nine kinds and modes of desire. An instrument was developed to test the applicability of the Lacanian model. It was developed in five phases which included three pilot studies and two samplings. A total of 591 respondents participated in the empirical research study with 428 in the first sample and 70 in the second; the remaining 93 made up the pilot studies. Unlike the initial version of the instrument used in the first sample (n=428) the data obtained by the last version (n=70) revealed that the instrument held some form of reliability and validity. Once analysed through descriptive and inferential statistics the data supported the view that individuals tended to display dominance in a kind and mode of desire as per the Lacanian model, and sufficient variance existed to preliminarily conclude that this model could be used as a means to value segment employees. Recommendations were as follows: (1) that complexity methodology should inform future motivation theorising, (2) that the proposed complexity models be further empirically tested, (3) that an adequately complex, flexible rewards system be considered, (4) that both managers and employees make use of the developed instrument to aid them in the selection of rewards that will lead to increased satisfaction.
- Full Text:
- Date Issued: 2010
- Authors: Botha, Anton Ivan
- Date: 2010
- Subjects: Employee motivation , Employee morale , Incentive awards
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:9400 , http://hdl.handle.net/10948/1232 , Employee motivation , Employee morale , Incentive awards
- Description: Since employee motivation contributes to overall organisational success, reliable motivation theory should inform management and reward practices. Yet, motivation theory is currently in a state of paralysis, with no constructive theorising taking place. Analysis of its methodological presuppositions reveals that it relies on out-dated binary thinking, prioritising, e.g. either a ‘machine-like’ (body driven) or ‘god-like’ (rationally driven) understanding of humanity. In this study it is argued that the revival of motivation theory requires a paradigmatic shift towards a complexity methodology because human motivation was found to be a complex system and must be theorised accordingly. It was found that McAdams’ theory of personality which brought together personality traits, conditioning, and motives could form the basis of a complex theory of motivation. On this basis, a complex model was developed which incorporated elements of existing motivational theories. This model proposed that drives, which motivate behaviour, are a combination of instincts, needs, and desires, mediated by personality traits, rational processing, and conditioning. All of these interconnected elements, as well as biological and environmental conditions, have an impact on, and are influenced by one another. For the purposes of understanding employee motivation the element of desire was isolated as a potential means to value segment employees. A Lacanian theory was utilised to elaborate on the element of desire. This theory postulated that individuals tend to display a dominance is one of nine kinds and modes of desire. An instrument was developed to test the applicability of the Lacanian model. It was developed in five phases which included three pilot studies and two samplings. A total of 591 respondents participated in the empirical research study with 428 in the first sample and 70 in the second; the remaining 93 made up the pilot studies. Unlike the initial version of the instrument used in the first sample (n=428) the data obtained by the last version (n=70) revealed that the instrument held some form of reliability and validity. Once analysed through descriptive and inferential statistics the data supported the view that individuals tended to display dominance in a kind and mode of desire as per the Lacanian model, and sufficient variance existed to preliminarily conclude that this model could be used as a means to value segment employees. Recommendations were as follows: (1) that complexity methodology should inform future motivation theorising, (2) that the proposed complexity models be further empirically tested, (3) that an adequately complex, flexible rewards system be considered, (4) that both managers and employees make use of the developed instrument to aid them in the selection of rewards that will lead to increased satisfaction.
- Full Text:
- Date Issued: 2010
Movement patterns and population dynamics of four catsharks endemic to South Africa
- Authors: Escobar-Porras, Jessica
- Date: 2010
- Subjects: Chondrichthyes -- South Africa , Fish populations -- South Africa , Fishes -- Behavior -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5303 , http://hdl.handle.net/10962/d1005148 , Chondrichthyes -- South Africa , Fish populations -- South Africa , Fishes -- Behavior -- South Africa
- Description: Sharks are particularly vulnerable to over-exploitation. Although catsharks are an important component of the near-shore marine biodiversity in South Africa and most of the species are endemic, little is known about their movement patterns, home range and population size. With an increasing number of recreational fishers this information is crucial for their conservation. The aims of this study were threefold. Firstly, to identify and analyze existing data sources on movement patterns and population dynamics for four catshark species: pyjama (Poroderma africanum), leopard (P. pantherinum), puffadder (Haploblepharus edwarsii) and brown (H. fuscus). This highlighted a number of shortcomings with existing data sets, largely because these studies had diverse objectives and were not aimed solely at catsharks. Secondly, a dedicated study was carried out for a limited area, testing a number of methods for data collection, and where appropriate the data was analyzed to determine movement patterns and population numbers. Thirdly, the most appropriate methodology for future studies (with similar objectives) was identified, and the results of the study were used to propose a number of conservation measures. All species of catsharks exhibited strong site fidelity and limited dispersal for extended periods. A few individuals did, however, travel distances in excess of 150 km. Significant trends in temporal abundance were not observed, nevertheless, there was some evidence for higher catches from September to December. Population estimates for the study area were low, with P. africanum having the smallest population size while H. fuscus had the highest population size within the restricted study area. Limited movements, high site fidelity and small population sizes emphasize their vulnerability and suggest that catsharks would benefit from no-take marine protected areas.
- Full Text:
- Date Issued: 2010
- Authors: Escobar-Porras, Jessica
- Date: 2010
- Subjects: Chondrichthyes -- South Africa , Fish populations -- South Africa , Fishes -- Behavior -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5303 , http://hdl.handle.net/10962/d1005148 , Chondrichthyes -- South Africa , Fish populations -- South Africa , Fishes -- Behavior -- South Africa
- Description: Sharks are particularly vulnerable to over-exploitation. Although catsharks are an important component of the near-shore marine biodiversity in South Africa and most of the species are endemic, little is known about their movement patterns, home range and population size. With an increasing number of recreational fishers this information is crucial for their conservation. The aims of this study were threefold. Firstly, to identify and analyze existing data sources on movement patterns and population dynamics for four catshark species: pyjama (Poroderma africanum), leopard (P. pantherinum), puffadder (Haploblepharus edwarsii) and brown (H. fuscus). This highlighted a number of shortcomings with existing data sets, largely because these studies had diverse objectives and were not aimed solely at catsharks. Secondly, a dedicated study was carried out for a limited area, testing a number of methods for data collection, and where appropriate the data was analyzed to determine movement patterns and population numbers. Thirdly, the most appropriate methodology for future studies (with similar objectives) was identified, and the results of the study were used to propose a number of conservation measures. All species of catsharks exhibited strong site fidelity and limited dispersal for extended periods. A few individuals did, however, travel distances in excess of 150 km. Significant trends in temporal abundance were not observed, nevertheless, there was some evidence for higher catches from September to December. Population estimates for the study area were low, with P. africanum having the smallest population size while H. fuscus had the highest population size within the restricted study area. Limited movements, high site fidelity and small population sizes emphasize their vulnerability and suggest that catsharks would benefit from no-take marine protected areas.
- Full Text:
- Date Issued: 2010
Narrative play therapy and the journey of a boy diagnosed with a learning disability: a case study
- Authors: Topper, Kegan
- Date: 2010
- Subjects: Play therapy -- Case studies , Narrative therapy -- Case studies , Children with disabilities , Learning disabilities , Cognitive therapy for children , Play -- Psychological aspects
- Language: English
- Type: Thesis , Masters , M Soc Sc (C Psy)
- Identifier: vital:11854 , http://hdl.handle.net/10353/313 , Play therapy -- Case studies , Narrative therapy -- Case studies , Children with disabilities , Learning disabilities , Cognitive therapy for children , Play -- Psychological aspects
- Description: This study offers a detailed exploration of the personal narrative of a nine year old boy diagnosed with a learning disability, and explains how the nature of the therapeutic relationship facilitated shifts in his personal understandings of himself, others and the world. Children diagnosed with learning disabilities experience a range of challenges in their different life contexts, and particularly within the school context. This is often because of constant evaluation and surveillance from teachers, family members and peers, who define the child within rigid and limiting frameworks. Soon enough children diagnosed with learning disabilities develop problem-saturated narratives that can significantly influence their relationship with themselves and others. This is because the individualising effects of having a disability cause them to feel different or isolated from their peers. This study illustrates an eight session case study, facilitated by a narrative play therapy approach, between a counsellor, a child and his parents. The therapeutic encounters were intended to assist the child in moving away from problem-saturated narratives of incompetence and inferiority towards more preferred narratives that would positively influence his self esteem. Key words: learning disability, dyslexia, narrative, narrative therapy, identity, self esteem. Children Diagnosed with a Learning Disability Children who have been diagnosed with a learning disability often experience themselves and their world very differently from other children (Rodis, Garrod, & Boscardin, 2001). Within the educational system a considerable amount of pressure is placed on children to succeed. The educational discourse of achievement that professes itself to be the only direction from which a successful future can be attained, marginalizes and rejects those children whose knowledge and skills exist outside this rigid and oftentimes insensitive system of evaluation. As a result, children soon create problem saturated narratives, believing themselves to be the problem. However, in the last two decades there has been a move from reductionism to constructivism and as a result research in the field of learning disabilities has started to focus on children’s non-traditional strengths and talents, which are often misunderstood and ignored by schools. Armstrong (1987) sums it up as follows: The schools allow millions of imaginative kids to go unrecognised
- Full Text:
- Date Issued: 2010
- Authors: Topper, Kegan
- Date: 2010
- Subjects: Play therapy -- Case studies , Narrative therapy -- Case studies , Children with disabilities , Learning disabilities , Cognitive therapy for children , Play -- Psychological aspects
- Language: English
- Type: Thesis , Masters , M Soc Sc (C Psy)
- Identifier: vital:11854 , http://hdl.handle.net/10353/313 , Play therapy -- Case studies , Narrative therapy -- Case studies , Children with disabilities , Learning disabilities , Cognitive therapy for children , Play -- Psychological aspects
- Description: This study offers a detailed exploration of the personal narrative of a nine year old boy diagnosed with a learning disability, and explains how the nature of the therapeutic relationship facilitated shifts in his personal understandings of himself, others and the world. Children diagnosed with learning disabilities experience a range of challenges in their different life contexts, and particularly within the school context. This is often because of constant evaluation and surveillance from teachers, family members and peers, who define the child within rigid and limiting frameworks. Soon enough children diagnosed with learning disabilities develop problem-saturated narratives that can significantly influence their relationship with themselves and others. This is because the individualising effects of having a disability cause them to feel different or isolated from their peers. This study illustrates an eight session case study, facilitated by a narrative play therapy approach, between a counsellor, a child and his parents. The therapeutic encounters were intended to assist the child in moving away from problem-saturated narratives of incompetence and inferiority towards more preferred narratives that would positively influence his self esteem. Key words: learning disability, dyslexia, narrative, narrative therapy, identity, self esteem. Children Diagnosed with a Learning Disability Children who have been diagnosed with a learning disability often experience themselves and their world very differently from other children (Rodis, Garrod, & Boscardin, 2001). Within the educational system a considerable amount of pressure is placed on children to succeed. The educational discourse of achievement that professes itself to be the only direction from which a successful future can be attained, marginalizes and rejects those children whose knowledge and skills exist outside this rigid and oftentimes insensitive system of evaluation. As a result, children soon create problem saturated narratives, believing themselves to be the problem. However, in the last two decades there has been a move from reductionism to constructivism and as a result research in the field of learning disabilities has started to focus on children’s non-traditional strengths and talents, which are often misunderstood and ignored by schools. Armstrong (1987) sums it up as follows: The schools allow millions of imaginative kids to go unrecognised
- Full Text:
- Date Issued: 2010
Nature, narrative and language in Marlene van Niekerk's Agaat
- Authors: Moore-Barnes, Shannon-Lee
- Date: 2010
- Subjects: Van Niekerk, Marlene. Agaat , Narration (Rhetoric) , Storytelling , Women and literature -- South Africa , Afrikaans fiction -- 21st century
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8453 , http://hdl.handle.net/10948/1235 , Van Niekerk, Marlene. Agaat , Narration (Rhetoric) , Storytelling , Women and literature -- South Africa , Afrikaans fiction -- 21st century
- Description: Conrad Aiken’s observation that the “landscape and the language are the same, and we ourselves are language and are land,” depicts the material terrain we inhabit as necessarily informing the language we speak. An important corollary to Aiken’s observation is language itself writes the land. I argue that the binary division between culture and nature, as well as the attempts to universalise languages, abstracts discourse from necessary situated knowledges, alienating the land from the language it embodies. The severing of culture and nature as implied by Aiken’s observation is indicative of humanity’s progressive isolation from the land through language, as well as from their embodied natures. Remoteness results in what Marlene van Niekerk’s novel Agaat (2006) terms a “poverty disease” (2006: 251). Michiel Heyns confirms that the character Agaat relates this barrenness of spirit to her “diagnosis of spiritual ills through human dealings with the soil” (2009: 132). I illustrate the novel’s revitalisation of language as an act of ecological recuperation that alleviates dis-eased consciousnesses by potentially recognising, valuing and responding to situated knowledges revealed in land narratives.1 My argument therefore uncovers the challenges that the novel directs at an unreformed and universal Western2 To this end I use critiques of colonialism that reveal culture’s assimilation of the Other, rationalist discourse that continues to appropriate nature as resource for a hierarchical culture. 3 By combining this literary analysis with a wider eco-theoretical enquiry I position my study in an interdisciplinary field of investigation. This is in response to the damaging consequences of the inherited and fragmentary nature of specialisation. In addition, by detailing literary and feminist especially the work of Val Plumwood, Donna Haraway and Nicole Brossard. I use these critiques to analyse self/Other oppositions that Western culture constructs and patrols to maintain a defensive culture of domination. I show how nature and all those feminised and marginalised by Western discourses that hierarchise culture have been consistently overlooked and under-represented by those who purport to ‘control’ the environment and privilege the symbolic language as the carrier of culture. Agaat provides fruitful terrain for the reflection of marginalised voices; voices that confirm the environment and language as necessarily both feminist and social justice issues. 1 My preference for the hyphenated usage of the word ‘dis-ease’ signals the equation between discomfort or unease and disease or sickness. 2 While I am concerned over emphasising words such as Western and Apartheid by capitalising them, I have decided to retain this form so as not to diminish the magnitude of the effect these discourses have had on global and regional communities. 3 When referring to Others I, like Karen J. Warren, capitalise the term. Warren defines Others as all earth Others subjected to “unjustified domination-subordination relationships” (2005: 252). responses to Western patriarchal discourse and its impact on nature, I show the ways in which literature negotiates the possible re-conceptualisation of our collective cultural imagination. Van Niekerk’s novel offers a sustained critique of the oppressive Western conceptual frameworks that have dominated Others through hegemonic constructions. Furthermore, I investigate what this writer might offer as an alternative to systems of social, political and ecological control and the violence it inflicts.
- Full Text:
- Date Issued: 2010
- Authors: Moore-Barnes, Shannon-Lee
- Date: 2010
- Subjects: Van Niekerk, Marlene. Agaat , Narration (Rhetoric) , Storytelling , Women and literature -- South Africa , Afrikaans fiction -- 21st century
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8453 , http://hdl.handle.net/10948/1235 , Van Niekerk, Marlene. Agaat , Narration (Rhetoric) , Storytelling , Women and literature -- South Africa , Afrikaans fiction -- 21st century
- Description: Conrad Aiken’s observation that the “landscape and the language are the same, and we ourselves are language and are land,” depicts the material terrain we inhabit as necessarily informing the language we speak. An important corollary to Aiken’s observation is language itself writes the land. I argue that the binary division between culture and nature, as well as the attempts to universalise languages, abstracts discourse from necessary situated knowledges, alienating the land from the language it embodies. The severing of culture and nature as implied by Aiken’s observation is indicative of humanity’s progressive isolation from the land through language, as well as from their embodied natures. Remoteness results in what Marlene van Niekerk’s novel Agaat (2006) terms a “poverty disease” (2006: 251). Michiel Heyns confirms that the character Agaat relates this barrenness of spirit to her “diagnosis of spiritual ills through human dealings with the soil” (2009: 132). I illustrate the novel’s revitalisation of language as an act of ecological recuperation that alleviates dis-eased consciousnesses by potentially recognising, valuing and responding to situated knowledges revealed in land narratives.1 My argument therefore uncovers the challenges that the novel directs at an unreformed and universal Western2 To this end I use critiques of colonialism that reveal culture’s assimilation of the Other, rationalist discourse that continues to appropriate nature as resource for a hierarchical culture. 3 By combining this literary analysis with a wider eco-theoretical enquiry I position my study in an interdisciplinary field of investigation. This is in response to the damaging consequences of the inherited and fragmentary nature of specialisation. In addition, by detailing literary and feminist especially the work of Val Plumwood, Donna Haraway and Nicole Brossard. I use these critiques to analyse self/Other oppositions that Western culture constructs and patrols to maintain a defensive culture of domination. I show how nature and all those feminised and marginalised by Western discourses that hierarchise culture have been consistently overlooked and under-represented by those who purport to ‘control’ the environment and privilege the symbolic language as the carrier of culture. Agaat provides fruitful terrain for the reflection of marginalised voices; voices that confirm the environment and language as necessarily both feminist and social justice issues. 1 My preference for the hyphenated usage of the word ‘dis-ease’ signals the equation between discomfort or unease and disease or sickness. 2 While I am concerned over emphasising words such as Western and Apartheid by capitalising them, I have decided to retain this form so as not to diminish the magnitude of the effect these discourses have had on global and regional communities. 3 When referring to Others I, like Karen J. Warren, capitalise the term. Warren defines Others as all earth Others subjected to “unjustified domination-subordination relationships” (2005: 252). responses to Western patriarchal discourse and its impact on nature, I show the ways in which literature negotiates the possible re-conceptualisation of our collective cultural imagination. Van Niekerk’s novel offers a sustained critique of the oppressive Western conceptual frameworks that have dominated Others through hegemonic constructions. Furthermore, I investigate what this writer might offer as an alternative to systems of social, political and ecological control and the violence it inflicts.
- Full Text:
- Date Issued: 2010
Navigating between information security management documents : a modeling methodology
- Authors: Domingues, Steve
- Date: 2010
- Subjects: Computer security -- Management , Business -- Data processing -- Security measures , Information resources management -- Security measures , Business -- Standards
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9761 , http://hdl.handle.net/10948/1212 , Computer security -- Management , Business -- Data processing -- Security measures , Information resources management -- Security measures , Business -- Standards
- Description: Organizations no longer draft their own standards. Instead, organizations take advantage of the available international standards. One standard may not cover all the organization's needs, requiring organizations to implement more than one standard. The same aspect in an organization may be covered by two or more standards, creating an overlap. An awareness of such overlaps led to various institutions creating mapping documents illustrating how a control from one standard relates to a control from a different standard. The mapping documents are consulted by the end user, to identify how a control in one standard may relate to other standards. This allows the end user to navigate between the standards documents. These mapping documents are valuable to a person who wishes to grasp how different standards deal with a specific control. However, the navigation between standards is a cumbersome task. In order to navigate between the standards the end user is required to consult three or more documents, depending on the number of standards that are mapped to the control being investigated. The need for a tool that will provide fast and efficient navigation between standards was identified. The data tier of the tool is the focus of this dissertation. As a result, this research proposes a modeling methodology that will allow for the modeling of the standards and the information about the mapping between standards, thereby contributing to the creation of tools to aid in the navigation between standards. A comparison between the major data modeling paradigms identifies multi-dimensional modeling as the most appropriate technique to model standards. Adapting an existing modeling methodology to cater for the modeling standards, yield a five step standard modeling methodology. Once modeled, the standards can be physically implemented as a database. The database schema that results from the standard modeling methodology adheres to a specific pattern and can thus be expressed according to well-defined meta-model. This allows for the generation of SQL statements by a tool with limited knowledge of the standards in a way that allows the quick navigation between standards. To determine the usefulness of the standards modeling methodology the research presents iv a prototype that utilizes the well-defined meta-model to navigate between standards. It is shown that, as far as navigation is concerned, no code changes are necessary when adding a new standard or new mappings between standards. This research contributes to the creation of a tool that can easily navigate between standards by providing the ability to model the data tier in such a way that it is extensible, yet remains independent of the application and presentation tiers.
- Full Text:
- Date Issued: 2010
- Authors: Domingues, Steve
- Date: 2010
- Subjects: Computer security -- Management , Business -- Data processing -- Security measures , Information resources management -- Security measures , Business -- Standards
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9761 , http://hdl.handle.net/10948/1212 , Computer security -- Management , Business -- Data processing -- Security measures , Information resources management -- Security measures , Business -- Standards
- Description: Organizations no longer draft their own standards. Instead, organizations take advantage of the available international standards. One standard may not cover all the organization's needs, requiring organizations to implement more than one standard. The same aspect in an organization may be covered by two or more standards, creating an overlap. An awareness of such overlaps led to various institutions creating mapping documents illustrating how a control from one standard relates to a control from a different standard. The mapping documents are consulted by the end user, to identify how a control in one standard may relate to other standards. This allows the end user to navigate between the standards documents. These mapping documents are valuable to a person who wishes to grasp how different standards deal with a specific control. However, the navigation between standards is a cumbersome task. In order to navigate between the standards the end user is required to consult three or more documents, depending on the number of standards that are mapped to the control being investigated. The need for a tool that will provide fast and efficient navigation between standards was identified. The data tier of the tool is the focus of this dissertation. As a result, this research proposes a modeling methodology that will allow for the modeling of the standards and the information about the mapping between standards, thereby contributing to the creation of tools to aid in the navigation between standards. A comparison between the major data modeling paradigms identifies multi-dimensional modeling as the most appropriate technique to model standards. Adapting an existing modeling methodology to cater for the modeling standards, yield a five step standard modeling methodology. Once modeled, the standards can be physically implemented as a database. The database schema that results from the standard modeling methodology adheres to a specific pattern and can thus be expressed according to well-defined meta-model. This allows for the generation of SQL statements by a tool with limited knowledge of the standards in a way that allows the quick navigation between standards. To determine the usefulness of the standards modeling methodology the research presents iv a prototype that utilizes the well-defined meta-model to navigate between standards. It is shown that, as far as navigation is concerned, no code changes are necessary when adding a new standard or new mappings between standards. This research contributes to the creation of a tool that can easily navigate between standards by providing the ability to model the data tier in such a way that it is extensible, yet remains independent of the application and presentation tiers.
- Full Text:
- Date Issued: 2010
Negotiating sexuality in Grahamstown East: young black women's experiences of relationships in the context of HIV risk
- Authors: Clüver, Frances Rose Mannix
- Date: 2010
- Subjects: HIV infections -- South Africa -- Grahamstown Man-woman relationships -- South Africa -- Grahamstown Intimacy -- South Africa -- Grahamstown Sex -- South Africa -- Grahamstown Youth, Black -- South Africa -- Grahamstown -- Sexual behavior HIV infections -- Social aspects -- South Africa -- Grahamstown Youth, Black -- South Africa -- Grahamstown -- Attitudes Reproductive health -- South Africa -- Grahamstown Health education -- South Africa -- Grahamstown Youth, Black -- South Africa -- Grahamstown -- Health and hygiene Phenomenological psychology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2951 , http://hdl.handle.net/10962/d1002460
- Description: Adolescent sexual health has been identified as a significant health and development problem facing South Africa. Limited amounts of research on sexual interactions have been undertaken, with information on adolescents’ romantic relationships being particularly scarce. Qualitative research needs to foster an understanding of the dynamics of sexual interactions in specific settings, and with emphasis in the past on cognitive health psychology models, very little is thus known about how adolescents negotiate and make sense of their sexual experiences. This highlights the need to investigate the complexities of human sexuality in a contextual manner. In response, this study explores the lived experiences of four young black women as they negotiate their agency and sexuality in a local context. By way of in-depth qualitative interviews, which were analysed for recurrent themes using interpretative phenomenological analysis, this project examines the participants’ experiences regarding sex, relationships, communication, sexual health care, as well as HIV and pregnancy prevention. The results reveal that communication about sexuality in the participants’ homes was limited if not absent altogether. When seeking sexual health care, they found clinic nurses to be judgemental and rude. Regarding sexuality and HIV education, the participants stressed the need for outside educators to teach in more practical ways to increase efficacy. In their dating relationships, most participants revealed their boyfriends had a great deal of influence over their sexual initiation. Unwanted pregnancy surfaced as a greater fear than HIV in their accounts due to pressure to finish their education and attain well-paying jobs in the future. The participants felt unable to stop their boyfriends’ infidelity and had limited agency when facing sexual demands. Their accounts revealed that they negotiate their agency in an atmosphere of coercion and the threat of rape. However, areas of agency included their consistent condom use even when facing pressure to have unprotected sex, and their active accessing of sexual health services for hormonal contraception. These insights serve to better inform sexual and reproductive health education and intervention programmes for young women. Moreover, educators, researchers and programme developers alike may gain useful insights from the personalised accounts derived from this study.
- Full Text:
- Date Issued: 2010
- Authors: Clüver, Frances Rose Mannix
- Date: 2010
- Subjects: HIV infections -- South Africa -- Grahamstown Man-woman relationships -- South Africa -- Grahamstown Intimacy -- South Africa -- Grahamstown Sex -- South Africa -- Grahamstown Youth, Black -- South Africa -- Grahamstown -- Sexual behavior HIV infections -- Social aspects -- South Africa -- Grahamstown Youth, Black -- South Africa -- Grahamstown -- Attitudes Reproductive health -- South Africa -- Grahamstown Health education -- South Africa -- Grahamstown Youth, Black -- South Africa -- Grahamstown -- Health and hygiene Phenomenological psychology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2951 , http://hdl.handle.net/10962/d1002460
- Description: Adolescent sexual health has been identified as a significant health and development problem facing South Africa. Limited amounts of research on sexual interactions have been undertaken, with information on adolescents’ romantic relationships being particularly scarce. Qualitative research needs to foster an understanding of the dynamics of sexual interactions in specific settings, and with emphasis in the past on cognitive health psychology models, very little is thus known about how adolescents negotiate and make sense of their sexual experiences. This highlights the need to investigate the complexities of human sexuality in a contextual manner. In response, this study explores the lived experiences of four young black women as they negotiate their agency and sexuality in a local context. By way of in-depth qualitative interviews, which were analysed for recurrent themes using interpretative phenomenological analysis, this project examines the participants’ experiences regarding sex, relationships, communication, sexual health care, as well as HIV and pregnancy prevention. The results reveal that communication about sexuality in the participants’ homes was limited if not absent altogether. When seeking sexual health care, they found clinic nurses to be judgemental and rude. Regarding sexuality and HIV education, the participants stressed the need for outside educators to teach in more practical ways to increase efficacy. In their dating relationships, most participants revealed their boyfriends had a great deal of influence over their sexual initiation. Unwanted pregnancy surfaced as a greater fear than HIV in their accounts due to pressure to finish their education and attain well-paying jobs in the future. The participants felt unable to stop their boyfriends’ infidelity and had limited agency when facing sexual demands. Their accounts revealed that they negotiate their agency in an atmosphere of coercion and the threat of rape. However, areas of agency included their consistent condom use even when facing pressure to have unprotected sex, and their active accessing of sexual health services for hormonal contraception. These insights serve to better inform sexual and reproductive health education and intervention programmes for young women. Moreover, educators, researchers and programme developers alike may gain useful insights from the personalised accounts derived from this study.
- Full Text:
- Date Issued: 2010
Neotectonics and its applications for the exploration of groundwater in the fractured Karoo aquifers in the Eastern Cape,South Africa
- Authors: Madi, Kakaba
- Date: 2010
- Subjects: Water well drilling -- South Africa -- Eastern Cape , Aquifers -- South Africa -- Eastern Cape , Water -- supply engineering -- South Africa -- Eastern Cape , Prospecting -- Geophysical methods , Groundwater -- Research -- Methodology
- Language: English
- Type: Thesis , Masters , MSc (Geology)
- Identifier: vital:11523 , http://hdl.handle.net/10353/362 , Water well drilling -- South Africa -- Eastern Cape , Aquifers -- South Africa -- Eastern Cape , Water -- supply engineering -- South Africa -- Eastern Cape , Prospecting -- Geophysical methods , Groundwater -- Research -- Methodology
- Description: This study is part of an NRF sponsored research project entitled “Neotectonics and its applications for the exploration of groundwater in the fractured Karoo aquifers in the Eastern Cape” under the NRF Niche area of Water Resources Management and Sustainable Development in the Eastern Cape Province. The identification of relatively highly productive wells in the Karoo fractured aquifers is extremely difficult. This study aims to identify neotectonic zones and lower stress fields, and apply the results to groundwater exploration in the Eastern Cape Province. The methodologies adopted in this study include: a comprehensive literature review, extensive field mapping and investigation such as road cuts, sampling for laboratory studies, examination of seismic data, study of hot and ordinary springs, and interpretation of aerial photography and satellite images. Three main neotectonic belts were identified in the Eastern Cape (southern neotectonic belt, northern neotectonic belt and eastern neotectonic belt) based on literature review and field interpretations. The southern neotectonic belt (from the Cape Fold Belt to the lower Beaufort Group boundary) is characterized by the reactivation of the Coega-Bavianskloof and Sauer faults, the presence of a hot spring near Fort Beaufort, the slickenlines and discrete slickenlines and specifically the seismic events that were recorded in the Eastern Cape from 1850 to 2007. In this southern neotectonic belt the remote sensing has also revealed the presence of the Fort Beaufort fracture, the quartz veins seen in some dolerites and the different vegetation types along it may indicate that this fracture is possibly a fault; moreover the Quaternary sediments and weathered dolerites indicate that the Fort iii Beaufort fracture is characterized by groundwater circulation and accordingly is a good target for groundwater exploration, this fracture is a post-Karoo structure and possibly a neotectonic feature. In addition, the kaolin deposit, chiefly developed in the Dwyka tillite near Grahamstown is clearly controlled by neotectonic fracture zones. The northern neotectonic belt near the country of Lesotho is marked by the presence of the Senqu seismotectonic regime and hot springs. The Quaternary Amatole-Swaziland (formerly Ciskei-Swaziland) axis of uplift makes the eastern part of the province the third neotectonic zone, the asymmetric meanders of the Mbashe river in the vicinity of Qunu near Mthatha derived possibly from this Quaternary uplift; this asymmetric feature of meanders implies that the river has tried to maintain stability of its valley where tilting occurred. Within these neotectonic belts the central part of the Eastern Cape may be considered a static and inactive belt. A northwesterly trend for the maximum principal compresssional stress predominates in the Eastern Cape and is correlated with the present major structural control of the province. The current stress regime determination was derived from faults, joints and quartz veins only on kaolin deposits. Systematic joints reflect regional tectonic stress trajectories at the time of fracturing. Discharge rates of groundwater from boreholes as provided by the Department of Water and Forestry were used to confirm and predict water exploration targets. The region of Tabankulu (near Kwazulu Natal) in the northern neotectonic belt has remarkable discharge rates of groundwater (11.1 l/s, 4.65 l/s, 6.49 l/s, 42 l/s). The region of Mthatha, nearly surrounding the Amatole-Swaziland axis (former Ciskei-Swaziland iv axis) of uplift which might have generated some new faults, has a number of springs. These two regions should serve as case studies for future research. Apart from these two regions, two others regions can be considered as case studies for future groundwater exploration targets: the Bath Farm hot spring near the Fort Beaufort neotectonic fault and the vicinity of what is known as the Fort Beaufort fracture near Teba and Cimezile villages 20km north west of Fort Beaufort. It is concluded that the study of neotectonics and stress fields may be a useful tool for groundwater exploration in the Karoo fractured aquifers in the Eastern Cape, and in similar regions elsewhere in South Africa and in Africa.
- Full Text:
- Date Issued: 2010
- Authors: Madi, Kakaba
- Date: 2010
- Subjects: Water well drilling -- South Africa -- Eastern Cape , Aquifers -- South Africa -- Eastern Cape , Water -- supply engineering -- South Africa -- Eastern Cape , Prospecting -- Geophysical methods , Groundwater -- Research -- Methodology
- Language: English
- Type: Thesis , Masters , MSc (Geology)
- Identifier: vital:11523 , http://hdl.handle.net/10353/362 , Water well drilling -- South Africa -- Eastern Cape , Aquifers -- South Africa -- Eastern Cape , Water -- supply engineering -- South Africa -- Eastern Cape , Prospecting -- Geophysical methods , Groundwater -- Research -- Methodology
- Description: This study is part of an NRF sponsored research project entitled “Neotectonics and its applications for the exploration of groundwater in the fractured Karoo aquifers in the Eastern Cape” under the NRF Niche area of Water Resources Management and Sustainable Development in the Eastern Cape Province. The identification of relatively highly productive wells in the Karoo fractured aquifers is extremely difficult. This study aims to identify neotectonic zones and lower stress fields, and apply the results to groundwater exploration in the Eastern Cape Province. The methodologies adopted in this study include: a comprehensive literature review, extensive field mapping and investigation such as road cuts, sampling for laboratory studies, examination of seismic data, study of hot and ordinary springs, and interpretation of aerial photography and satellite images. Three main neotectonic belts were identified in the Eastern Cape (southern neotectonic belt, northern neotectonic belt and eastern neotectonic belt) based on literature review and field interpretations. The southern neotectonic belt (from the Cape Fold Belt to the lower Beaufort Group boundary) is characterized by the reactivation of the Coega-Bavianskloof and Sauer faults, the presence of a hot spring near Fort Beaufort, the slickenlines and discrete slickenlines and specifically the seismic events that were recorded in the Eastern Cape from 1850 to 2007. In this southern neotectonic belt the remote sensing has also revealed the presence of the Fort Beaufort fracture, the quartz veins seen in some dolerites and the different vegetation types along it may indicate that this fracture is possibly a fault; moreover the Quaternary sediments and weathered dolerites indicate that the Fort iii Beaufort fracture is characterized by groundwater circulation and accordingly is a good target for groundwater exploration, this fracture is a post-Karoo structure and possibly a neotectonic feature. In addition, the kaolin deposit, chiefly developed in the Dwyka tillite near Grahamstown is clearly controlled by neotectonic fracture zones. The northern neotectonic belt near the country of Lesotho is marked by the presence of the Senqu seismotectonic regime and hot springs. The Quaternary Amatole-Swaziland (formerly Ciskei-Swaziland) axis of uplift makes the eastern part of the province the third neotectonic zone, the asymmetric meanders of the Mbashe river in the vicinity of Qunu near Mthatha derived possibly from this Quaternary uplift; this asymmetric feature of meanders implies that the river has tried to maintain stability of its valley where tilting occurred. Within these neotectonic belts the central part of the Eastern Cape may be considered a static and inactive belt. A northwesterly trend for the maximum principal compresssional stress predominates in the Eastern Cape and is correlated with the present major structural control of the province. The current stress regime determination was derived from faults, joints and quartz veins only on kaolin deposits. Systematic joints reflect regional tectonic stress trajectories at the time of fracturing. Discharge rates of groundwater from boreholes as provided by the Department of Water and Forestry were used to confirm and predict water exploration targets. The region of Tabankulu (near Kwazulu Natal) in the northern neotectonic belt has remarkable discharge rates of groundwater (11.1 l/s, 4.65 l/s, 6.49 l/s, 42 l/s). The region of Mthatha, nearly surrounding the Amatole-Swaziland axis (former Ciskei-Swaziland iv axis) of uplift which might have generated some new faults, has a number of springs. These two regions should serve as case studies for future research. Apart from these two regions, two others regions can be considered as case studies for future groundwater exploration targets: the Bath Farm hot spring near the Fort Beaufort neotectonic fault and the vicinity of what is known as the Fort Beaufort fracture near Teba and Cimezile villages 20km north west of Fort Beaufort. It is concluded that the study of neotectonics and stress fields may be a useful tool for groundwater exploration in the Karoo fractured aquifers in the Eastern Cape, and in similar regions elsewhere in South Africa and in Africa.
- Full Text:
- Date Issued: 2010
Nest site fidelity and nest site selection of loggerhead, Caretta Caretta, and leatherback, dermochelys coriacea, turtles in KwaZulu-Natal, South Africa
- Authors: Botha, Marié
- Date: 2010
- Subjects: Sea turtles -- South Africa -- KwaZulu-Natal , Loggerhead turtle -- South Africa -- KwaZulu-Natal , Leatherback turtle -- South Africa -- KwaZulu-Natal , Nest building , Turtles -- Habitat
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10696 , http://hdl.handle.net/10948/1233 , Sea turtles -- South Africa -- KwaZulu-Natal , Loggerhead turtle -- South Africa -- KwaZulu-Natal , Leatherback turtle -- South Africa -- KwaZulu-Natal , Nest building , Turtles -- Habitat
- Description: Loggerhead and leatherback sea turtles nest on the beaches of the north-eastern portion of Kwazulu-Natal within the iSimangaliso Wetland Park. Loggerheads place ~60 percent of all nests within an 8 km stretch of beach, whereas leatherbacks tend to space their nests more evenly along the entire length of the monitoring area. The study aimed to determine nest site fidelity of loggerheads and leatherbacks (using four decades of nesting data housed by Ezemvelo KZN Wildlife) and the factors that influence nest site selection of both species within the 56 km of turtle monitoring area (32N to 100S) and the 5 km area of high-density loggerhead nesting (0N to 12N). The effectiveness of nest site selection was then determined through the hatching success of loggerheads over the 5km area (0N to 12N). Results showed that loggerheads show a high degree of nest site fidelity (~3 km) with nest site fidelity of individuals increasing over subsequent seasons of nesting, as well as these individuals using the same stretches of beach for nesting (the most popular area being 1N to 4N for repeat nesters). Leatherbacks displayed nest site fidelity of ~9 km and this did not increase over successive seasons of nesting. In terms of nest site selection, loggerheads and leatherbacks both avoided areas where low shore rock was present, whereas both species preferred nesting on beaches of intermediate morphodynamic state. Leatherback nesting was significantly higher in areas with wider surf zones. Both species were able to surpass the high water mark when nesting as nests below this point would be almost certainly doomed. Hatching success of loggerheads was comparative to high (83 %) relative to other studies, however, nest success varied across the beach from beacon 1N to 12N. Areas where highest nest success was observed were not areas of highest nest density presumably due to artificial lighting. Results from this study increase our understanding of the evolutionary biology of loggerhead and leatherback turtles in South Africa and the effectiveness of loggerhead nest site selection through hatching success.
- Full Text:
- Date Issued: 2010
- Authors: Botha, Marié
- Date: 2010
- Subjects: Sea turtles -- South Africa -- KwaZulu-Natal , Loggerhead turtle -- South Africa -- KwaZulu-Natal , Leatherback turtle -- South Africa -- KwaZulu-Natal , Nest building , Turtles -- Habitat
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10696 , http://hdl.handle.net/10948/1233 , Sea turtles -- South Africa -- KwaZulu-Natal , Loggerhead turtle -- South Africa -- KwaZulu-Natal , Leatherback turtle -- South Africa -- KwaZulu-Natal , Nest building , Turtles -- Habitat
- Description: Loggerhead and leatherback sea turtles nest on the beaches of the north-eastern portion of Kwazulu-Natal within the iSimangaliso Wetland Park. Loggerheads place ~60 percent of all nests within an 8 km stretch of beach, whereas leatherbacks tend to space their nests more evenly along the entire length of the monitoring area. The study aimed to determine nest site fidelity of loggerheads and leatherbacks (using four decades of nesting data housed by Ezemvelo KZN Wildlife) and the factors that influence nest site selection of both species within the 56 km of turtle monitoring area (32N to 100S) and the 5 km area of high-density loggerhead nesting (0N to 12N). The effectiveness of nest site selection was then determined through the hatching success of loggerheads over the 5km area (0N to 12N). Results showed that loggerheads show a high degree of nest site fidelity (~3 km) with nest site fidelity of individuals increasing over subsequent seasons of nesting, as well as these individuals using the same stretches of beach for nesting (the most popular area being 1N to 4N for repeat nesters). Leatherbacks displayed nest site fidelity of ~9 km and this did not increase over successive seasons of nesting. In terms of nest site selection, loggerheads and leatherbacks both avoided areas where low shore rock was present, whereas both species preferred nesting on beaches of intermediate morphodynamic state. Leatherback nesting was significantly higher in areas with wider surf zones. Both species were able to surpass the high water mark when nesting as nests below this point would be almost certainly doomed. Hatching success of loggerheads was comparative to high (83 %) relative to other studies, however, nest success varied across the beach from beacon 1N to 12N. Areas where highest nest success was observed were not areas of highest nest density presumably due to artificial lighting. Results from this study increase our understanding of the evolutionary biology of loggerhead and leatherback turtles in South Africa and the effectiveness of loggerhead nest site selection through hatching success.
- Full Text:
- Date Issued: 2010
Network management for community networks
- Authors: Wells, Daniel David
- Date: 2010 , 2010-03-26
- Subjects: Computer networks -- Management , Internet -- South Africa , Internet -- Management , Broadband communication systems
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4643 , http://hdl.handle.net/10962/d1006587
- Description: Community networks (in South Africa and Africa) are often serviced by limited bandwidth network backhauls. Relative to the basic needs of the community, this is an expensive ongoing concern. In many cases the Internet connection is shared among multiple sites. Community networks may also have a lack of technical personnel to maintain a network of this nature. Hence, there is a demand for a system which will monitor and manage bandwidth use, as well as network use. The proposed solution for community networks and the focus within this dissertation, is a system of two parts. A Community Access Point (CAP) is located at each site within the community network. This provides the hosts and servers at that site with access to services on the community network and the Internet, it is the site's router. The CAP provides a web based interface (CAPgui) which allows configuration of the device and viewing of simple monitoring statistics. The Access Concentrator (AC) is the default router for the CAPs and the gateway to the Internet. It provides authenticated and encrypted communication between the network sites. The AC performs several monitoring functions, both for the individual sites and for the upstream Internet connection. The AC provides a means for centrally managing and effectively allocating Internet bandwidth by using the web based interface (ACgui). Bandwidth use can be allocated per user, per host and per site. The system is maintainable, extendable and customisable for different network architectures. The system was deployed successfully to two community networks. The Centre of Excellence (CoE) testbed network is a peri-urban network deployment whereas the Siyakhula Living Lab (SLL) network is a rural deployment. The results gathered conclude that the project was successful as the deployed system is more robust and more manageable than the previous systems.
- Full Text:
- Date Issued: 2010
- Authors: Wells, Daniel David
- Date: 2010 , 2010-03-26
- Subjects: Computer networks -- Management , Internet -- South Africa , Internet -- Management , Broadband communication systems
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4643 , http://hdl.handle.net/10962/d1006587
- Description: Community networks (in South Africa and Africa) are often serviced by limited bandwidth network backhauls. Relative to the basic needs of the community, this is an expensive ongoing concern. In many cases the Internet connection is shared among multiple sites. Community networks may also have a lack of technical personnel to maintain a network of this nature. Hence, there is a demand for a system which will monitor and manage bandwidth use, as well as network use. The proposed solution for community networks and the focus within this dissertation, is a system of two parts. A Community Access Point (CAP) is located at each site within the community network. This provides the hosts and servers at that site with access to services on the community network and the Internet, it is the site's router. The CAP provides a web based interface (CAPgui) which allows configuration of the device and viewing of simple monitoring statistics. The Access Concentrator (AC) is the default router for the CAPs and the gateway to the Internet. It provides authenticated and encrypted communication between the network sites. The AC performs several monitoring functions, both for the individual sites and for the upstream Internet connection. The AC provides a means for centrally managing and effectively allocating Internet bandwidth by using the web based interface (ACgui). Bandwidth use can be allocated per user, per host and per site. The system is maintainable, extendable and customisable for different network architectures. The system was deployed successfully to two community networks. The Centre of Excellence (CoE) testbed network is a peri-urban network deployment whereas the Siyakhula Living Lab (SLL) network is a rural deployment. The results gathered conclude that the project was successful as the deployed system is more robust and more manageable than the previous systems.
- Full Text:
- Date Issued: 2010
New platinum and palladium complexes: their anticancer application
- Authors: Louw, Marissa
- Date: 2010
- Subjects: Complex compounds -- Synthesis , Ligands (Biochemistry) , Antineoplastic antibiotics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10424 , http://hdl.handle.net/10948/d1016218
- Description: Novel non-leaving groups were employed in this dissertation to synthesize platinum complexes which can assist in the understanding or improvement of anticancer action. Emphasis was placed on (NS)-chelate and (NN)-chelate platinum complexes. Bidentate (NS)-donor ligands were used as non-leaving ligands in the synthesis of platinum(II) complexes with iodo, chloro, bromo and oxalato groups as leaving groups. These complexes were synthesized and studied since many questions regarding the interaction of sulfur-donors and platinum still exist. These relate to thermodynamic and kinetic factors and their influence on anticancer action. In this dissertation the properties of novel platinum(II) complexes of a bidentate ligand having an aromatic nitrogen-donor atom in combination with a thioethereal sulfur atom capable of forming a five-membered ring with platinum(II) were studied. The general structure of the (NS)-ligands used was 2-((alkylthio)methyl)pyridine. Alkyl groups used were methyl, ethyl, propyl, benzyl and phenyl. Amine complexes of platinum have been studied extensively in the past. However, attention was given to novel aspects of substituted pyridine and imidazole ligands and their corresponding complexes. Amongst these are 2-(2-methylaminoethyl)pyridine, 1-methyl-2-methylaminoethylimidazole and 1-methyl-2-methylaminobenzylimidazole. The leaving groups included chloro, bromo and oxalato. Mononitroplatinum(IV) complexes were prepared using novel synthetic methods. Selected platinum(II) amine complexes were used as starting materials for this synthesis. Some of these compounds exhibit promising anticancer behaviour. (Trans-(R,R)-1,2-diaminocyclohexane)(oxalato)(mononitrochloro)platinum(IV) is a particularly good anticancer agent and has been patented internationally. All these complexes were characterized using mass spectrometry, chromatography, thermogravimetric analysis, kinetic aspects such as ligand exchange rates and finally their anticancer action against three different cancer cell lines was evaluated via cytotoxicity assays. Some of the compounds exhibited particularly good anticancer potential.
- Full Text:
- Date Issued: 2010
- Authors: Louw, Marissa
- Date: 2010
- Subjects: Complex compounds -- Synthesis , Ligands (Biochemistry) , Antineoplastic antibiotics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10424 , http://hdl.handle.net/10948/d1016218
- Description: Novel non-leaving groups were employed in this dissertation to synthesize platinum complexes which can assist in the understanding or improvement of anticancer action. Emphasis was placed on (NS)-chelate and (NN)-chelate platinum complexes. Bidentate (NS)-donor ligands were used as non-leaving ligands in the synthesis of platinum(II) complexes with iodo, chloro, bromo and oxalato groups as leaving groups. These complexes were synthesized and studied since many questions regarding the interaction of sulfur-donors and platinum still exist. These relate to thermodynamic and kinetic factors and their influence on anticancer action. In this dissertation the properties of novel platinum(II) complexes of a bidentate ligand having an aromatic nitrogen-donor atom in combination with a thioethereal sulfur atom capable of forming a five-membered ring with platinum(II) were studied. The general structure of the (NS)-ligands used was 2-((alkylthio)methyl)pyridine. Alkyl groups used were methyl, ethyl, propyl, benzyl and phenyl. Amine complexes of platinum have been studied extensively in the past. However, attention was given to novel aspects of substituted pyridine and imidazole ligands and their corresponding complexes. Amongst these are 2-(2-methylaminoethyl)pyridine, 1-methyl-2-methylaminoethylimidazole and 1-methyl-2-methylaminobenzylimidazole. The leaving groups included chloro, bromo and oxalato. Mononitroplatinum(IV) complexes were prepared using novel synthetic methods. Selected platinum(II) amine complexes were used as starting materials for this synthesis. Some of these compounds exhibit promising anticancer behaviour. (Trans-(R,R)-1,2-diaminocyclohexane)(oxalato)(mononitrochloro)platinum(IV) is a particularly good anticancer agent and has been patented internationally. All these complexes were characterized using mass spectrometry, chromatography, thermogravimetric analysis, kinetic aspects such as ligand exchange rates and finally their anticancer action against three different cancer cell lines was evaluated via cytotoxicity assays. Some of the compounds exhibited particularly good anticancer potential.
- Full Text:
- Date Issued: 2010