A study on the effects of mental illness on relationships amongst families with the mentally ill members
- Authors: Magadla, Mfanisi Welcome
- Date: 2009
- Subjects: Families -- Health and hygiene , Mentally ill -- Home care , Mentally ill -- Family relationships , Mental illness
- Language: English
- Type: Thesis , Masters , MSc (Nursing Science)
- Identifier: vital:11901 , http://hdl.handle.net/10353/d1001101 , Families -- Health and hygiene , Mentally ill -- Home care , Mentally ill -- Family relationships , Mental illness
- Description: The increased abscondment of Mental Health Care Users from institutions of care, treatment and rehabilitation has prompted the researcher to conduct the study because patients who are not visited do not stand a chance of getting a Leave Of Absence (LOA). Problem: The concern is the danger of assault, murder, rape and other high risk situations the mentally ill individuals and the community are exposed to, which is caused by frequent abscondment of mentally unstable individuals who roam around the community without proper treatment and care. This is caused by failure of the relatives in coming to request patients for leave of absence (LOA). Purpose: The study investigated the effects of mental illness on relationships amongst families with the mentally ill members. The number or frequency of visitations by relatives to the mental health institutions is used by the researcher, to measure the nature of relationships between families and the psychiatric patients related to them. Method: The population comprised families of the mentally ill persons admitted at Cecilia Makiwane mental health units. The sample was collected conveniently as relatives came to visit the mentally ill until the desired number was reached. The designed tool was a questionnaire which was self administered. Data were analysed manually. Tables and graphs are shown in the results. Conclusion and Recommendations: The study revealed that approximately 100% of respondents had a lack of knowledge about mental illness and the mentally ill, in terms of care, treatment and rehabilitation hence they all need assistance in dealing with the mentally ill in the community. Findings also revealed that mental illness causes breakdown in family relationships. Recommendations regarding the enhancement of relationships between families and their mentally ill members are formulated as coping skills in the dissertation. The burden of having to deal with mentally ill person whose illness is not understood can lead the family to a state of confusion and iv not knowing what to anticipate. Lack of resources compounds the problem as the family members are not able to visit the ill member due to lack of funds (Baumann, 2007:637). The families with a mentally ill member usually shoulder the greatest part of the burden of mental illness (Uys and Middleton, 2004:77); unfortunately, lack of resources pose a problem.
- Full Text:
- Date Issued: 2009
- Authors: Magadla, Mfanisi Welcome
- Date: 2009
- Subjects: Families -- Health and hygiene , Mentally ill -- Home care , Mentally ill -- Family relationships , Mental illness
- Language: English
- Type: Thesis , Masters , MSc (Nursing Science)
- Identifier: vital:11901 , http://hdl.handle.net/10353/d1001101 , Families -- Health and hygiene , Mentally ill -- Home care , Mentally ill -- Family relationships , Mental illness
- Description: The increased abscondment of Mental Health Care Users from institutions of care, treatment and rehabilitation has prompted the researcher to conduct the study because patients who are not visited do not stand a chance of getting a Leave Of Absence (LOA). Problem: The concern is the danger of assault, murder, rape and other high risk situations the mentally ill individuals and the community are exposed to, which is caused by frequent abscondment of mentally unstable individuals who roam around the community without proper treatment and care. This is caused by failure of the relatives in coming to request patients for leave of absence (LOA). Purpose: The study investigated the effects of mental illness on relationships amongst families with the mentally ill members. The number or frequency of visitations by relatives to the mental health institutions is used by the researcher, to measure the nature of relationships between families and the psychiatric patients related to them. Method: The population comprised families of the mentally ill persons admitted at Cecilia Makiwane mental health units. The sample was collected conveniently as relatives came to visit the mentally ill until the desired number was reached. The designed tool was a questionnaire which was self administered. Data were analysed manually. Tables and graphs are shown in the results. Conclusion and Recommendations: The study revealed that approximately 100% of respondents had a lack of knowledge about mental illness and the mentally ill, in terms of care, treatment and rehabilitation hence they all need assistance in dealing with the mentally ill in the community. Findings also revealed that mental illness causes breakdown in family relationships. Recommendations regarding the enhancement of relationships between families and their mentally ill members are formulated as coping skills in the dissertation. The burden of having to deal with mentally ill person whose illness is not understood can lead the family to a state of confusion and iv not knowing what to anticipate. Lack of resources compounds the problem as the family members are not able to visit the ill member due to lack of funds (Baumann, 2007:637). The families with a mentally ill member usually shoulder the greatest part of the burden of mental illness (Uys and Middleton, 2004:77); unfortunately, lack of resources pose a problem.
- Full Text:
- Date Issued: 2009
A study on the knowledge and skills of police officers in handling mentally ill persons in Mdantsane in the Eastern Cape Province of South Africa
- Authors: Kolwapi, Xola Xolani
- Date: 2009
- Subjects: Mentally ill -- South Africa -- Eastern Cape , Police -- South Africa -- Eastern Cape , People with disabilities -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Nursing Science)
- Identifier: vital:11902 , http://hdl.handle.net/10353/406 , Mentally ill -- South Africa -- Eastern Cape , Police -- South Africa -- Eastern Cape , People with disabilities -- South Africa -- Eastern Cape
- Description: The dissertation argues that police officers are not trained in handling mentally ill persons. Purpose The study explored police officers‟ knowledge of mental illness and skills necessary for handling mentally ill people. Research methods The descriptive quantitative investigation has been used as a research strategy to identify the knowledge and skills of police officers in handling mentally ill persons. Forty five police officers were randomly selected from a population of 136 police officers. A self administered questionnaire was used for collecting data. Data analysis was done manually and frequency distributions, cross-tabulations and correlations were carried out. Results The findings revealed that police officers do not have knowledge and skills to handle mentally ill people. Recommendations It is recommended that mental health care practitioners should engage the police in discussions on training in handling mentally ill people. iv Limitations Due to time and budgetary limitations, the study had to settle for a more modest investigation
- Full Text:
- Date Issued: 2009
- Authors: Kolwapi, Xola Xolani
- Date: 2009
- Subjects: Mentally ill -- South Africa -- Eastern Cape , Police -- South Africa -- Eastern Cape , People with disabilities -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Nursing Science)
- Identifier: vital:11902 , http://hdl.handle.net/10353/406 , Mentally ill -- South Africa -- Eastern Cape , Police -- South Africa -- Eastern Cape , People with disabilities -- South Africa -- Eastern Cape
- Description: The dissertation argues that police officers are not trained in handling mentally ill persons. Purpose The study explored police officers‟ knowledge of mental illness and skills necessary for handling mentally ill people. Research methods The descriptive quantitative investigation has been used as a research strategy to identify the knowledge and skills of police officers in handling mentally ill persons. Forty five police officers were randomly selected from a population of 136 police officers. A self administered questionnaire was used for collecting data. Data analysis was done manually and frequency distributions, cross-tabulations and correlations were carried out. Results The findings revealed that police officers do not have knowledge and skills to handle mentally ill people. Recommendations It is recommended that mental health care practitioners should engage the police in discussions on training in handling mentally ill people. iv Limitations Due to time and budgetary limitations, the study had to settle for a more modest investigation
- Full Text:
- Date Issued: 2009
A feasibility study into the possibility of ionospheric propagation of low VHF (30-35 MHZ) signals between South Africa and Central Africa
- Authors: Coetzee, Petrus Johannes
- Date: 2009
- Subjects: Communications, Military -- South Africa , Communications, Military -- Africa, Central , Digital communications -- South Africa , Digital communications -- Africa, Central , Signals and signaling -- South Africa , Signals and signaling -- Africa, Central , Artificial satellites in telecommunication -- South Africa , Artificial satellites in telecommunication -- Africa, Central , Shortwave radio
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5465 , http://hdl.handle.net/10962/d1005250 , Communications, Military -- South Africa , Communications, Military -- Africa, Central , Digital communications -- South Africa , Digital communications -- Africa, Central , Signals and signaling -- South Africa , Signals and signaling -- Africa, Central , Artificial satellites in telecommunication -- South Africa , Artificial satellites in telecommunication -- Africa, Central , Shortwave radio
- Description: The role of the South African National Defence Force (SANDF) has changed considerably in the last decade. The emphasis has moved from protecting the country's borders to peacekeeping duties in Central Africa and even further North. Communications between the peacekeeping missions and the military bases back in South Africa is vital to ensure the success of these missions. Currently use is made of satellite as well as High Frequency (HF) communications. There are drawbacks associated with these technologies (high cost and low data rates/interference respectively). Successful long distance ionospheric propagation in the low Very High Frequency (VHF) range will complement the existing infrastructure and enhance the success rate of these missions. This thesis presents a feasibility study to determine under what ionospheric conditions such low VHF communications will be possible. The International Reference Ionosphere (IRI) was used to generate ionospheric data for the reflection point(s) of the signal. The peak height of the ionospheric F2 layer (hmF2) was used to calculate the required antenna elevation angle. Once the elevation angle is known it is possible to calculate the required F2 layer critical frequency (foF2). The required foF2 value was calculated by assuming a Maximum Useable Frequency (MUF) of 20% higher than the planned operational frequency. It was determined that single hop propagation is possible during the daytime if the smoothed sunspot number (SSN) exceeds 15. The most challenging requirement for successful single hop propagation is the need of an antenna height of 23 m. For rapid deployment and semi-mobile operations within a jungle environment it may prove to be a formidable obstacle.
- Full Text:
- Date Issued: 2009
- Authors: Coetzee, Petrus Johannes
- Date: 2009
- Subjects: Communications, Military -- South Africa , Communications, Military -- Africa, Central , Digital communications -- South Africa , Digital communications -- Africa, Central , Signals and signaling -- South Africa , Signals and signaling -- Africa, Central , Artificial satellites in telecommunication -- South Africa , Artificial satellites in telecommunication -- Africa, Central , Shortwave radio
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5465 , http://hdl.handle.net/10962/d1005250 , Communications, Military -- South Africa , Communications, Military -- Africa, Central , Digital communications -- South Africa , Digital communications -- Africa, Central , Signals and signaling -- South Africa , Signals and signaling -- Africa, Central , Artificial satellites in telecommunication -- South Africa , Artificial satellites in telecommunication -- Africa, Central , Shortwave radio
- Description: The role of the South African National Defence Force (SANDF) has changed considerably in the last decade. The emphasis has moved from protecting the country's borders to peacekeeping duties in Central Africa and even further North. Communications between the peacekeeping missions and the military bases back in South Africa is vital to ensure the success of these missions. Currently use is made of satellite as well as High Frequency (HF) communications. There are drawbacks associated with these technologies (high cost and low data rates/interference respectively). Successful long distance ionospheric propagation in the low Very High Frequency (VHF) range will complement the existing infrastructure and enhance the success rate of these missions. This thesis presents a feasibility study to determine under what ionospheric conditions such low VHF communications will be possible. The International Reference Ionosphere (IRI) was used to generate ionospheric data for the reflection point(s) of the signal. The peak height of the ionospheric F2 layer (hmF2) was used to calculate the required antenna elevation angle. Once the elevation angle is known it is possible to calculate the required F2 layer critical frequency (foF2). The required foF2 value was calculated by assuming a Maximum Useable Frequency (MUF) of 20% higher than the planned operational frequency. It was determined that single hop propagation is possible during the daytime if the smoothed sunspot number (SSN) exceeds 15. The most challenging requirement for successful single hop propagation is the need of an antenna height of 23 m. For rapid deployment and semi-mobile operations within a jungle environment it may prove to be a formidable obstacle.
- Full Text:
- Date Issued: 2009
Study South Africa
- International Education Association of South Africa (IEASA), Jooste, Nico
- Authors: International Education Association of South Africa (IEASA) , Jooste, Nico
- Date: 2009
- Subjects: Education, Higher -- South Africa , Universities and colleges -- South Africa , Technical Institutes -- South Africa , Vocational guidance -- South Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/64983 , vital:28642 , ISBN 9780620448161
- Description: [Extract from message from Minister of Higher Education and Training, Hon. Dr BE Nzimande]: It gives me pleasure to provide support to the International Education Association of South Africa’s (IEASA) 9th edition of the Study South Africa publication. The focus of this edition, which is Higher Education and Development in South Africa, is most appropriate today as South Africa continuously strives to ensure that higher education remains relevant and responsive to the developmental needs of the country. To this end, we always have to bear in mind that South Africa is a developing country, and as such still confronts challenges such as poverty and under-development. These challenges are characteristic of most developing countries, particularly in sub-Saharan Africa. Thus, our higher education sector, through its core functions of teaching, research, and community engagement, should seek to address these issues especially as they affect the poor and other vulnerable members of our society. Since we became a democratic state in 1994, South Africa has gone a long way to transform and restructure our higher education system to ensure amongst others equity with regard to the demographics of our staff and student population. The gender and racial profile of our students has improved significantly over the years to the extent that we now have black and female students constituting the majority at our institutions, especially at undergraduate level. It is also pleasing to note that our institutions enjoy good international standing. South African researchers and institutions continue to engage in research collaborations with their peers and counterparts around the world, and thus, are integral parts of research programmes and networks. With respect to student mobility, our higher education institutions continue to attract large numbers of international students, particularly from other parts of Africa. In 2007 the number of international students enrolled at our institutions was counted at 59 209, a significant increase from 44 439 in 2000. About 85% of these students originate from the African continent, more specifically the Southern African Development Community (SADC) region. Several factors account for the increase in the number of international students coming to South Africa. These include the country’s natural and ecological resources, rich and diverse cultural heritage, and the stable socio-political conditions. The consistent growth in the number of international students seeking to study in South Africa is a positive affirmation on the quality of the country’s institutions and the international reputation of their academics and qualifications. As a country, we see this growth as a positive development as it provides us with the opportunity not only to impart or relate our experiences, but also, to learn from others, and by so doing further enhance the international standing of our higher education system. , 9th Edition
- Full Text:
- Date Issued: 2009
- Authors: International Education Association of South Africa (IEASA) , Jooste, Nico
- Date: 2009
- Subjects: Education, Higher -- South Africa , Universities and colleges -- South Africa , Technical Institutes -- South Africa , Vocational guidance -- South Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/64983 , vital:28642 , ISBN 9780620448161
- Description: [Extract from message from Minister of Higher Education and Training, Hon. Dr BE Nzimande]: It gives me pleasure to provide support to the International Education Association of South Africa’s (IEASA) 9th edition of the Study South Africa publication. The focus of this edition, which is Higher Education and Development in South Africa, is most appropriate today as South Africa continuously strives to ensure that higher education remains relevant and responsive to the developmental needs of the country. To this end, we always have to bear in mind that South Africa is a developing country, and as such still confronts challenges such as poverty and under-development. These challenges are characteristic of most developing countries, particularly in sub-Saharan Africa. Thus, our higher education sector, through its core functions of teaching, research, and community engagement, should seek to address these issues especially as they affect the poor and other vulnerable members of our society. Since we became a democratic state in 1994, South Africa has gone a long way to transform and restructure our higher education system to ensure amongst others equity with regard to the demographics of our staff and student population. The gender and racial profile of our students has improved significantly over the years to the extent that we now have black and female students constituting the majority at our institutions, especially at undergraduate level. It is also pleasing to note that our institutions enjoy good international standing. South African researchers and institutions continue to engage in research collaborations with their peers and counterparts around the world, and thus, are integral parts of research programmes and networks. With respect to student mobility, our higher education institutions continue to attract large numbers of international students, particularly from other parts of Africa. In 2007 the number of international students enrolled at our institutions was counted at 59 209, a significant increase from 44 439 in 2000. About 85% of these students originate from the African continent, more specifically the Southern African Development Community (SADC) region. Several factors account for the increase in the number of international students coming to South Africa. These include the country’s natural and ecological resources, rich and diverse cultural heritage, and the stable socio-political conditions. The consistent growth in the number of international students seeking to study in South Africa is a positive affirmation on the quality of the country’s institutions and the international reputation of their academics and qualifications. As a country, we see this growth as a positive development as it provides us with the opportunity not only to impart or relate our experiences, but also, to learn from others, and by so doing further enhance the international standing of our higher education system. , 9th Edition
- Full Text:
- Date Issued: 2009
Rhodes University Graduation Ceremony 2009
- Authors: Rhodes University
- Date: 2009
- Language: English
- Type: text
- Identifier: vital:8138 , http://hdl.handle.net/10962/d1007250
- Description: Rhodes University Graduation Ceremonies [at] 1820 Settlers National Monument Thursday, 16 April at 18:00 [and] Friday, 17 April at 10:30; 14:30 & 18:00 [and] Saturday, 18 April at 10:30
- Full Text:
- Date Issued: 2009
- Authors: Rhodes University
- Date: 2009
- Language: English
- Type: text
- Identifier: vital:8138 , http://hdl.handle.net/10962/d1007250
- Description: Rhodes University Graduation Ceremonies [at] 1820 Settlers National Monument Thursday, 16 April at 18:00 [and] Friday, 17 April at 10:30; 14:30 & 18:00 [and] Saturday, 18 April at 10:30
- Full Text:
- Date Issued: 2009
Drawing Lines in the Sand: AM v RM 2010 2 SA 223 (ECP)
- Authors: Kruuse, Helen
- Date: 2009
- Language: English
- Type: Article , text
- Identifier: http://hdl.handle.net/10962/54107 , vital:26391 , http://www.ufh.ac.za/speculumjuris/files/pdf/SpeculumJuris_2009_Part_2.pdf
- Description: Judge Elna Revelas’s decision in the case of Mohamed v Mohamed 1 may be described as one of those run-of-the-mill applications in terms of rule 43 which are routinely heard on motion court days in any one of our high courts across the country. This case note suggests that her decision belies such a description. Instead, this note suggests that her decision marks a move away from existing jurisprudence on Muslim marriages in a way which may undermine, rather than promote, the recognition and respect for the marriage institutions of different religious systems and beliefs. I tentatively suggest that by granting the rule 43 application the court may have effectively imposed civil marriage obligations on a religious marriage even though the parties had not concluded a marriage in terms of the Marriage Act.2 As such, the decision has potentially radical consequences for parties in Muslim marriages and highlights the complex issues that courts have had to face in the last two decades without any guiding legislation. In order to understand the judgment properly, its context has to be considered. This context includes (1) the numerous judgments extending protection to women in Muslim marriages in the last two decades against the backdrop of the coming into effect of the Constitution of the Republic of South Africa, 1996; and (2) the application by the Women’s Legal Centre Trust (hereafter “WLCT”) to the Constitutional Court to force the President and Parliament to enact legislation to recognise and protect Muslim marriages.
- Full Text:
- Date Issued: 2009
- Authors: Kruuse, Helen
- Date: 2009
- Language: English
- Type: Article , text
- Identifier: http://hdl.handle.net/10962/54107 , vital:26391 , http://www.ufh.ac.za/speculumjuris/files/pdf/SpeculumJuris_2009_Part_2.pdf
- Description: Judge Elna Revelas’s decision in the case of Mohamed v Mohamed 1 may be described as one of those run-of-the-mill applications in terms of rule 43 which are routinely heard on motion court days in any one of our high courts across the country. This case note suggests that her decision belies such a description. Instead, this note suggests that her decision marks a move away from existing jurisprudence on Muslim marriages in a way which may undermine, rather than promote, the recognition and respect for the marriage institutions of different religious systems and beliefs. I tentatively suggest that by granting the rule 43 application the court may have effectively imposed civil marriage obligations on a religious marriage even though the parties had not concluded a marriage in terms of the Marriage Act.2 As such, the decision has potentially radical consequences for parties in Muslim marriages and highlights the complex issues that courts have had to face in the last two decades without any guiding legislation. In order to understand the judgment properly, its context has to be considered. This context includes (1) the numerous judgments extending protection to women in Muslim marriages in the last two decades against the backdrop of the coming into effect of the Constitution of the Republic of South Africa, 1996; and (2) the application by the Women’s Legal Centre Trust (hereafter “WLCT”) to the Constitutional Court to force the President and Parliament to enact legislation to recognise and protect Muslim marriages.
- Full Text:
- Date Issued: 2009
Application of Baylis-Hillman methodology in the construction of complex heterocyclic targets
- Ganto, Mlungiseleli MacDonald
- Authors: Ganto, Mlungiseleli MacDonald
- Date: 2009
- Subjects: Heterocyclic compounds -- Derivatives Heterocyclic chemistry
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4401 , http://hdl.handle.net/10962/d1006703
- Description: Baylis-Hillman reactions using various aromatic aldehydes, activated alkenes and catalysts have been used to: - access an extensive range of poly-heterocyclic products;explore chemoselectivity; and optimise reaction efficiency. Chromone-3-carbaldehydes and chromone-2-carbaldehydes, prepared via Vielsmeier-Haack and Kostanecki-Robinson methodology, respectively, have been used as Baylis-Hillman substrates with four different catalysts, viz., 1,4-diazabicyclo[2.2.2]octane (DABCO), 3-hydroxyquinuclidine (3-HQ), imidazole and N’,N’,N’,N’- tetramethylpropanediamine (TMPDA), and with methyl vinyl ketone (MVK), methyl acrylate, cyclic enones (2-cyclohexen-1-one, 2-cyclopenten-1-one and chromones) as activated alkenes. Reactions of the chromone- -carbaldehydes with MVK afforded dimeric Baylis-Hillman adducts when catalyzed by DABCO but when the same reactions were repeated using 3-HQ as catalyst, the dimeric products were accompanied by tricyclic Baylis-Hillman adducts. Use of excess MVK, however, led to mixtures of the normal Baylis-Hillman adducts and the tricyclic adducts – interestingly, with the apparent absence of the dimeric products. While reactions of chromone-3-carbaldehydes with methyl acrylate afforded the normal Baylis-Hillman adducts, the chromone-2- carbaldehydes produced, instead, rearrangement products, consistent with an earlier, single observation. Reactions of 2-nitrobenzaldehydes with cyclic enones using imidazole as catalyst afforded the normal Baylis-Hillman adducts, reductive cyclisation of the 2-cyclohexen-1- one and 2-cyclopenten-1-one adducts, using acetic acid and iron powder, afforded the corresponding quinoline erivatives. Treatment of cyclic enones with pyridine-2-carbaldehydes and quinoline-2-carbaldehydes using TMPDA as catalyst generally gave the expected Baylis-Hillman adducts. However, indolizine derivatives were isolated directly from Baylis-Hillman reactions involving pyridine-2-carbaldehydes and 2-cyclohexen-1-one. The remaining Baylis-Hillman adducts were cyclized to the corresponding indolizines by treatment with acetic anhydride both under reflux and under microwave-assisted conditions, the latter approach providing remarkably rapid and efficient access to the polycyclic products. Computer modelling studies have been conducted on selected polycyclic products at the Molecular Mechanics (MM), Quantum Mechanical (QM) and Density Functional (DFT) levels. The theoretical results have been used to calculate UV, IR and NMR absorption data, which have been compared, in turn, with the experimental spectroscopic data. Use has also been made of the estreNova NMR prediction programme and, generally, good agreement has been observed between the predicted and experimental spectroscopic data.
- Full Text:
- Date Issued: 2009
- Authors: Ganto, Mlungiseleli MacDonald
- Date: 2009
- Subjects: Heterocyclic compounds -- Derivatives Heterocyclic chemistry
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4401 , http://hdl.handle.net/10962/d1006703
- Description: Baylis-Hillman reactions using various aromatic aldehydes, activated alkenes and catalysts have been used to: - access an extensive range of poly-heterocyclic products;explore chemoselectivity; and optimise reaction efficiency. Chromone-3-carbaldehydes and chromone-2-carbaldehydes, prepared via Vielsmeier-Haack and Kostanecki-Robinson methodology, respectively, have been used as Baylis-Hillman substrates with four different catalysts, viz., 1,4-diazabicyclo[2.2.2]octane (DABCO), 3-hydroxyquinuclidine (3-HQ), imidazole and N’,N’,N’,N’- tetramethylpropanediamine (TMPDA), and with methyl vinyl ketone (MVK), methyl acrylate, cyclic enones (2-cyclohexen-1-one, 2-cyclopenten-1-one and chromones) as activated alkenes. Reactions of the chromone- -carbaldehydes with MVK afforded dimeric Baylis-Hillman adducts when catalyzed by DABCO but when the same reactions were repeated using 3-HQ as catalyst, the dimeric products were accompanied by tricyclic Baylis-Hillman adducts. Use of excess MVK, however, led to mixtures of the normal Baylis-Hillman adducts and the tricyclic adducts – interestingly, with the apparent absence of the dimeric products. While reactions of chromone-3-carbaldehydes with methyl acrylate afforded the normal Baylis-Hillman adducts, the chromone-2- carbaldehydes produced, instead, rearrangement products, consistent with an earlier, single observation. Reactions of 2-nitrobenzaldehydes with cyclic enones using imidazole as catalyst afforded the normal Baylis-Hillman adducts, reductive cyclisation of the 2-cyclohexen-1- one and 2-cyclopenten-1-one adducts, using acetic acid and iron powder, afforded the corresponding quinoline erivatives. Treatment of cyclic enones with pyridine-2-carbaldehydes and quinoline-2-carbaldehydes using TMPDA as catalyst generally gave the expected Baylis-Hillman adducts. However, indolizine derivatives were isolated directly from Baylis-Hillman reactions involving pyridine-2-carbaldehydes and 2-cyclohexen-1-one. The remaining Baylis-Hillman adducts were cyclized to the corresponding indolizines by treatment with acetic anhydride both under reflux and under microwave-assisted conditions, the latter approach providing remarkably rapid and efficient access to the polycyclic products. Computer modelling studies have been conducted on selected polycyclic products at the Molecular Mechanics (MM), Quantum Mechanical (QM) and Density Functional (DFT) levels. The theoretical results have been used to calculate UV, IR and NMR absorption data, which have been compared, in turn, with the experimental spectroscopic data. Use has also been made of the estreNova NMR prediction programme and, generally, good agreement has been observed between the predicted and experimental spectroscopic data.
- Full Text:
- Date Issued: 2009
Attitudes and perceptions towards TB in Grahamstown East in a time of HIV/AIDS
- Authors: Ndoro, Tinashe T. R
- Date: 2009
- Subjects: Tuberculosis -- South Africa -- Grahamstown , AIDS (Disease) -- Social aspects -- South Africa -- Grahamstown , HIV (Viruses) -- Social aspects -- South Africa -- Grahamstown , Tuberculosis -- Social aspects -- South Africa -- Grahamstown , Tuberculosis -- Prevention -- South Africa -- Grahamstown , AIDS (Disease) -- South Africa -- Grahamstown -- Public opinion , Tuberculosis -- South Africa -- Grahamstown -- Public opinion , Health surveys -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:3030 , http://hdl.handle.net/10962/d1002539 , Tuberculosis -- South Africa -- Grahamstown , AIDS (Disease) -- Social aspects -- South Africa -- Grahamstown , HIV (Viruses) -- Social aspects -- South Africa -- Grahamstown , Tuberculosis -- Social aspects -- South Africa -- Grahamstown , Tuberculosis -- Prevention -- South Africa -- Grahamstown , AIDS (Disease) -- South Africa -- Grahamstown -- Public opinion , Tuberculosis -- South Africa -- Grahamstown -- Public opinion , Health surveys -- South Africa -- Grahamstown
- Description: Tuberculosis (TB) has become a serious South African health problem because it is the most common opportunistic disease that leads to death in people with HIV/AIDS. Due to the airborne nature of the disease it can easily be spread to anyone including healthy people. A lack of compliance to treatment by TB patients explains why prevalence rates of the disease are high and why there is an emergence of drug resistant strains such as XDR-TB and MDR-TB. Information on existing knowledge, attitudes and perceptions regarding TB can provide a crucial foundation for the development of educational programmes and interventions aimed at reducing the further spread of the disease. This study aimed at understanding the knowledge, attitudes and perceptions towards TB and relating these to the current prevalence of HIV/AIDS. A face-to-face interview survey was conducted among adult Grahamstown East residents (n=1020). The Health Belief Model (Rosenstock et al., 1994) and Bandura’s (1986) Social Cognitive Theory formed the theoretical framework of the data collection and analysis. The data generated from the field work was first descriptively analysed providing frequency tables. Thereafter cross tabulations were calculated for relevant items using independent variables, namely gender, level of education, and experience of dealing with TB. The results of the study show that, in general, knowledge concerning TB was sufficient to provide a foundation for the adoption of healthier behaviours in the female respondents. Few of the respondents reported feeling personally susceptible although the majority of the respondents acknowledged the severity of the disease. The cues to action lacked the influence to persuade people to adopt positive health related behaviours. The perceived benefits of adopting preventative behaviour were not very influential in the adoption of healthier behavioural changes in the respondents. Disease stigma regarding the dual association of TB and HIV/AIDS was the main barrier for the adoption of healthier behavioural attitudes. Perceived self-efficacy in preventative behaviours was generally low in the less educated respondents. Recommendations regarding areas for future research and change interventions are provided.
- Full Text:
- Date Issued: 2009
- Authors: Ndoro, Tinashe T. R
- Date: 2009
- Subjects: Tuberculosis -- South Africa -- Grahamstown , AIDS (Disease) -- Social aspects -- South Africa -- Grahamstown , HIV (Viruses) -- Social aspects -- South Africa -- Grahamstown , Tuberculosis -- Social aspects -- South Africa -- Grahamstown , Tuberculosis -- Prevention -- South Africa -- Grahamstown , AIDS (Disease) -- South Africa -- Grahamstown -- Public opinion , Tuberculosis -- South Africa -- Grahamstown -- Public opinion , Health surveys -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:3030 , http://hdl.handle.net/10962/d1002539 , Tuberculosis -- South Africa -- Grahamstown , AIDS (Disease) -- Social aspects -- South Africa -- Grahamstown , HIV (Viruses) -- Social aspects -- South Africa -- Grahamstown , Tuberculosis -- Social aspects -- South Africa -- Grahamstown , Tuberculosis -- Prevention -- South Africa -- Grahamstown , AIDS (Disease) -- South Africa -- Grahamstown -- Public opinion , Tuberculosis -- South Africa -- Grahamstown -- Public opinion , Health surveys -- South Africa -- Grahamstown
- Description: Tuberculosis (TB) has become a serious South African health problem because it is the most common opportunistic disease that leads to death in people with HIV/AIDS. Due to the airborne nature of the disease it can easily be spread to anyone including healthy people. A lack of compliance to treatment by TB patients explains why prevalence rates of the disease are high and why there is an emergence of drug resistant strains such as XDR-TB and MDR-TB. Information on existing knowledge, attitudes and perceptions regarding TB can provide a crucial foundation for the development of educational programmes and interventions aimed at reducing the further spread of the disease. This study aimed at understanding the knowledge, attitudes and perceptions towards TB and relating these to the current prevalence of HIV/AIDS. A face-to-face interview survey was conducted among adult Grahamstown East residents (n=1020). The Health Belief Model (Rosenstock et al., 1994) and Bandura’s (1986) Social Cognitive Theory formed the theoretical framework of the data collection and analysis. The data generated from the field work was first descriptively analysed providing frequency tables. Thereafter cross tabulations were calculated for relevant items using independent variables, namely gender, level of education, and experience of dealing with TB. The results of the study show that, in general, knowledge concerning TB was sufficient to provide a foundation for the adoption of healthier behaviours in the female respondents. Few of the respondents reported feeling personally susceptible although the majority of the respondents acknowledged the severity of the disease. The cues to action lacked the influence to persuade people to adopt positive health related behaviours. The perceived benefits of adopting preventative behaviour were not very influential in the adoption of healthier behavioural changes in the respondents. Disease stigma regarding the dual association of TB and HIV/AIDS was the main barrier for the adoption of healthier behavioural attitudes. Perceived self-efficacy in preventative behaviours was generally low in the less educated respondents. Recommendations regarding areas for future research and change interventions are provided.
- Full Text:
- Date Issued: 2009
Workers' perceptions of occupational safety and health administration measures at Sasol Infrachem in Sasolburg
- Authors: Kwayiba, Thamsanqa Felix
- Date: 2009
- Subjects: Petroleum chemicals industry -- Sasolburg , Industrial hygiene -- South Africa -- Sasolburg , Industrial safety -- South Africa -- Sasolburg
- Language: English
- Type: Thesis , Masters , MPhil (Environmental Studies)
- Identifier: vital:11878 , http://hdl.handle.net/10353/d1001090 , Petroleum chemicals industry -- Sasolburg , Industrial hygiene -- South Africa -- Sasolburg , Industrial safety -- South Africa -- Sasolburg
- Description: This is a qualitative study that seeks to explore the workers’ perceptions towards the occupational safety and health administration (OSHA) system at the petrochemical industrial plant Sasol Infrachem in Sasolburg. It provides a platform for shop floor workers to express their subjective perceptions of the company’s OSHA measures by answering open ended questions. The study advances the notion that notwithstanding the safety managers’ efforts towards ensuring a safety regime in the workplace, however lucrative these might be, to really ensure a safe working environment in the workplace will always depend on the individual workers’ motivation to participate safely at work at any given time to ensure his/her safety and that of others. The study explores this subject by considering how they perceive these safety strategies, their vigilance, attitudes, their ownership of these and their inclination to comply with the occupational safety and health administration measures of Sasol. This study follows a Postmodernist theoretical framework emphasizing differences. Difference is a first and foremost identity feature of human beings. This goes for both their external and internal qualities. How workers perceive and relate to safety concepts will always be shaped by the differences among them. The study also makes use of the Environmental Justice Theory as a central theme, that holds that one life lost is one too many. At the forefront of industries are shop floor workers who are most vulnerable to workplace incident.The study assumes this premise with regard to their safety and health in the workplace
- Full Text:
- Date Issued: 2009
- Authors: Kwayiba, Thamsanqa Felix
- Date: 2009
- Subjects: Petroleum chemicals industry -- Sasolburg , Industrial hygiene -- South Africa -- Sasolburg , Industrial safety -- South Africa -- Sasolburg
- Language: English
- Type: Thesis , Masters , MPhil (Environmental Studies)
- Identifier: vital:11878 , http://hdl.handle.net/10353/d1001090 , Petroleum chemicals industry -- Sasolburg , Industrial hygiene -- South Africa -- Sasolburg , Industrial safety -- South Africa -- Sasolburg
- Description: This is a qualitative study that seeks to explore the workers’ perceptions towards the occupational safety and health administration (OSHA) system at the petrochemical industrial plant Sasol Infrachem in Sasolburg. It provides a platform for shop floor workers to express their subjective perceptions of the company’s OSHA measures by answering open ended questions. The study advances the notion that notwithstanding the safety managers’ efforts towards ensuring a safety regime in the workplace, however lucrative these might be, to really ensure a safe working environment in the workplace will always depend on the individual workers’ motivation to participate safely at work at any given time to ensure his/her safety and that of others. The study explores this subject by considering how they perceive these safety strategies, their vigilance, attitudes, their ownership of these and their inclination to comply with the occupational safety and health administration measures of Sasol. This study follows a Postmodernist theoretical framework emphasizing differences. Difference is a first and foremost identity feature of human beings. This goes for both their external and internal qualities. How workers perceive and relate to safety concepts will always be shaped by the differences among them. The study also makes use of the Environmental Justice Theory as a central theme, that holds that one life lost is one too many. At the forefront of industries are shop floor workers who are most vulnerable to workplace incident.The study assumes this premise with regard to their safety and health in the workplace
- Full Text:
- Date Issued: 2009
An investigation into the antimicrobial and anticancer activities of Geranium incanum, Artemisia afra and Artemisia absinthium
- Authors: Freidberg, Ryno
- Date: 2009
- Subjects: Medicinal plants -- South Africa , Cancer -- Alternative treatment -- South Africa , Anti-infective agents
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10122 , http://hdl.handle.net/10948/1045 , Medicinal plants -- South Africa , Cancer -- Alternative treatment -- South Africa , Anti-infective agents
- Description: It has been estimated that between 3000 and 4000 plant species are used for their medicinal properties throughout South Africa, with approximately 27 million South Africans making use of traditional medicines. Of this 27 million, 3 million South Africans rely on traditional medicine as their primary source of health care. Of the 250 000 to 500 000 known plant species, very few have been investigated for their pharmacological qualities, and compounds of significant medicinal value may still remain undiscovered in many plant species. The aims of this study included investigating the antimicrobial properties of Geranium incanum and Artemisia afra, both plants traditionally used for their medicinal properties, and comparing the antimicrobial activity of the latter to that of Artemisia absinthium, as well as investigating the anticancer properties of G. incanum and A. afra, and comparing the anticancer activity of the latter to that of A. absinthium. Infusions, aqueous-, methanol- and acetone extracts of the three plants were prepared and used for anticancer and antimicrobial screening. Plant specimens used to prepare extracts for antimicrobial activity were collected and extracted over three seasons, while extracts used for anticancer screening were prepared from plants collected during the summer only. Considerable variation existed in the percentage crude extract yields obtained when different extractants were used, while the season in which the plants were harvested and extracted also appeared to play a significant role in the amount of extract obtained. The plant extracts were screened for antimicrobial activity against various strains of Candida albicans, Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus and Bacillus cereus, using an agar dilution method. G. incanum and A. afra possessed activity for C. albicans, while all three plants showed activity for S. aureus and B. cereus. Activity was largely dependent on the extraction method used. iii The 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay was used to screen for anticancer activity of the respective extracts, at varying concentrations, against MCF-7 (human breast adenocarcinoma) cells, HT-29 (human colonic adenocarcinoma) cells and HeLa (human cervical cancer) cells. All of the extracts showed cytotoxic activity in all three cell lines to varying extents, depending on the extract used and cell line screened. The acetone extract of A. afra proved to be the most effective inhibitor with the lowest IC50 (2.65 ± 1.05 μg/ml) having been shown in MCF-7 cells. A. afra and A. absinthium showed similar inhibitory patterns, with the methanol- and acetone extracts having been the most potent inhibitors of each of the respective cell lines in general. Fluorescence microscopy employing 4',6-diamidino-2-phenylindole dihydrochloride (DAPI) and propidium iodide (PI) staining indicated that the acetone extract of A. afra induces apoptosis in MCF-7 cells as apposed to necrosis, and the results were comparable to those obtained for cells exposed to cisplatin. Screening of the A. afra acetone extract for toxicity in normal human cells using the CellTiter-Blue® assay indicated the extract to be toxic to peripheral blood mononuclear cells (PBMC’s) at concentrations comparable to that for MCF-7 cells, while cell cycle analysis of MCF-7 cells exposed to the A. afra acetone extract indicated the extract’s ability to induce apoptosis comparable to that of cisplatin, with the extract exerting its activity at a point during or just prior to the S phase of the cell cycle.
- Full Text:
- Date Issued: 2009
- Authors: Freidberg, Ryno
- Date: 2009
- Subjects: Medicinal plants -- South Africa , Cancer -- Alternative treatment -- South Africa , Anti-infective agents
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10122 , http://hdl.handle.net/10948/1045 , Medicinal plants -- South Africa , Cancer -- Alternative treatment -- South Africa , Anti-infective agents
- Description: It has been estimated that between 3000 and 4000 plant species are used for their medicinal properties throughout South Africa, with approximately 27 million South Africans making use of traditional medicines. Of this 27 million, 3 million South Africans rely on traditional medicine as their primary source of health care. Of the 250 000 to 500 000 known plant species, very few have been investigated for their pharmacological qualities, and compounds of significant medicinal value may still remain undiscovered in many plant species. The aims of this study included investigating the antimicrobial properties of Geranium incanum and Artemisia afra, both plants traditionally used for their medicinal properties, and comparing the antimicrobial activity of the latter to that of Artemisia absinthium, as well as investigating the anticancer properties of G. incanum and A. afra, and comparing the anticancer activity of the latter to that of A. absinthium. Infusions, aqueous-, methanol- and acetone extracts of the three plants were prepared and used for anticancer and antimicrobial screening. Plant specimens used to prepare extracts for antimicrobial activity were collected and extracted over three seasons, while extracts used for anticancer screening were prepared from plants collected during the summer only. Considerable variation existed in the percentage crude extract yields obtained when different extractants were used, while the season in which the plants were harvested and extracted also appeared to play a significant role in the amount of extract obtained. The plant extracts were screened for antimicrobial activity against various strains of Candida albicans, Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus and Bacillus cereus, using an agar dilution method. G. incanum and A. afra possessed activity for C. albicans, while all three plants showed activity for S. aureus and B. cereus. Activity was largely dependent on the extraction method used. iii The 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay was used to screen for anticancer activity of the respective extracts, at varying concentrations, against MCF-7 (human breast adenocarcinoma) cells, HT-29 (human colonic adenocarcinoma) cells and HeLa (human cervical cancer) cells. All of the extracts showed cytotoxic activity in all three cell lines to varying extents, depending on the extract used and cell line screened. The acetone extract of A. afra proved to be the most effective inhibitor with the lowest IC50 (2.65 ± 1.05 μg/ml) having been shown in MCF-7 cells. A. afra and A. absinthium showed similar inhibitory patterns, with the methanol- and acetone extracts having been the most potent inhibitors of each of the respective cell lines in general. Fluorescence microscopy employing 4',6-diamidino-2-phenylindole dihydrochloride (DAPI) and propidium iodide (PI) staining indicated that the acetone extract of A. afra induces apoptosis in MCF-7 cells as apposed to necrosis, and the results were comparable to those obtained for cells exposed to cisplatin. Screening of the A. afra acetone extract for toxicity in normal human cells using the CellTiter-Blue® assay indicated the extract to be toxic to peripheral blood mononuclear cells (PBMC’s) at concentrations comparable to that for MCF-7 cells, while cell cycle analysis of MCF-7 cells exposed to the A. afra acetone extract indicated the extract’s ability to induce apoptosis comparable to that of cisplatin, with the extract exerting its activity at a point during or just prior to the S phase of the cell cycle.
- Full Text:
- Date Issued: 2009
Evaluation of a plant-herbivore system in determining potential efficacy of a candidate biological control agent, cornops aquaticum for water hyacinth, eichhornia crassipes
- Authors: Bownes, Angela
- Date: 2009
- Subjects: Water hyacinth -- Control -- South Africa , Eichhornia crassipedes , Pontederiaceae , Grasshoppers , Biological pest control agents -- South Africa , Weeds -- Biological control -- South Africa , Invasive plants -- Biological control -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5687 , http://hdl.handle.net/10962/d1005373
- Description: Water hyacinth, Eichhornia crassipes Mart. Solms-Laubach (Pontederiaceae), a freefloating aquatic macrophyte of Neotropical origin, was introduced into South Africa as an ornamental aquarium plant in the early 1900’s. By the 1970’s it had reached pest proportions in dams and rivers around the country. Due to the sustainability, cost efficiency and low environmental risk associated with biological control, this has been a widely used method in an attempt to reduce infestations to below the threshold where they cause economic and ecological damage. To date, five arthropod and one pathogen biocontrol agents have been introduced for the control of water hyacinth but their impact has been variable. It is believed that their efficacy is hampered by the presence of highly eutrophic systems in South Africa in which plant growth is prolific and the negative effects of herbivory are therefore mitigated. It is for these reasons that new, potentially more damaging biocontrol agents are being considered for release. The water hyacinth grasshopper, Cornops aquaticum Brüner (Orthoptera: Acrididae), which is native to South America and Mexico, was brought into quarantine in Pretoria, South Africa in 1995. Although the grasshopper was identified as one of the most damaging insects associated with water hyacinth in its native range, it has not been considered as a biocontrol agent for water hyacinth anywhere else in the world. After extensive host-range testing which revealed it to be safe for release, a release permit for this candidate agent was issued in 2007. However, host specificity testing is no longer considered to be the only important component of pre-release screening of candidate biocontrol agents. Investigating biological and ecological aspects of the plant-herbivore system that will assist in determination of potential establishment, efficacy and the ability to build up good populations in the recipient environment are some of the important factors. This thesis is a pre-release evaluation of C. aquaticum to determine whether it is sufficiently damaging to water hyacinth to warrant its release. It investigated interactions between the grasshopper and water hyacinth under a range of nutrient conditions found in South African water bodies as well as the impact of the grasshopper on the competitive performance of water hyacinth. Both plant growth rates and the response of water hyacinth to herbivory by the grasshopper were influenced by nutrient availability to the plants. The ability of water hyacinth to compensate for loss of tissue through herbivory was greater under eutrophic nutrient conditions. However, a negative linear relationship was found between grasshopper biomass and water hyacinth performance parameters such as biomass accumulation and leaf production, even under eutrophic conditions. Water hyacinth’s compensatory ability in terms of its potential to mitigate to detrimental effects of insect feeding was dependent on the amount of damage caused by herbivory by the grasshopper. Plant biomass and the competitive ability of water hyacinth in relation to another freefloating aquatic weed species were reduced by C. aquaticum under eutrophic nutrient conditions, in a short space of time. It was also found that grasshopper feeding and characteristics related to their population dynamics such as fecundity and survival were significantly influenced by water nutrient availability and that environmental nutrient availability will influence the control potential of this species should it be released in South Africa. Cornops aquaticum shows promise as a biocontrol agent for water hyacinth but additional factors that were not investigated in this study such as compatibility with the South African climate and the current water hyacinth biocontrol agents need to be combined with these data to make a decision on its release. Possible management options for this species if it is to be introduced into South Africa are discussed.
- Full Text:
- Date Issued: 2009
- Authors: Bownes, Angela
- Date: 2009
- Subjects: Water hyacinth -- Control -- South Africa , Eichhornia crassipedes , Pontederiaceae , Grasshoppers , Biological pest control agents -- South Africa , Weeds -- Biological control -- South Africa , Invasive plants -- Biological control -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5687 , http://hdl.handle.net/10962/d1005373
- Description: Water hyacinth, Eichhornia crassipes Mart. Solms-Laubach (Pontederiaceae), a freefloating aquatic macrophyte of Neotropical origin, was introduced into South Africa as an ornamental aquarium plant in the early 1900’s. By the 1970’s it had reached pest proportions in dams and rivers around the country. Due to the sustainability, cost efficiency and low environmental risk associated with biological control, this has been a widely used method in an attempt to reduce infestations to below the threshold where they cause economic and ecological damage. To date, five arthropod and one pathogen biocontrol agents have been introduced for the control of water hyacinth but their impact has been variable. It is believed that their efficacy is hampered by the presence of highly eutrophic systems in South Africa in which plant growth is prolific and the negative effects of herbivory are therefore mitigated. It is for these reasons that new, potentially more damaging biocontrol agents are being considered for release. The water hyacinth grasshopper, Cornops aquaticum Brüner (Orthoptera: Acrididae), which is native to South America and Mexico, was brought into quarantine in Pretoria, South Africa in 1995. Although the grasshopper was identified as one of the most damaging insects associated with water hyacinth in its native range, it has not been considered as a biocontrol agent for water hyacinth anywhere else in the world. After extensive host-range testing which revealed it to be safe for release, a release permit for this candidate agent was issued in 2007. However, host specificity testing is no longer considered to be the only important component of pre-release screening of candidate biocontrol agents. Investigating biological and ecological aspects of the plant-herbivore system that will assist in determination of potential establishment, efficacy and the ability to build up good populations in the recipient environment are some of the important factors. This thesis is a pre-release evaluation of C. aquaticum to determine whether it is sufficiently damaging to water hyacinth to warrant its release. It investigated interactions between the grasshopper and water hyacinth under a range of nutrient conditions found in South African water bodies as well as the impact of the grasshopper on the competitive performance of water hyacinth. Both plant growth rates and the response of water hyacinth to herbivory by the grasshopper were influenced by nutrient availability to the plants. The ability of water hyacinth to compensate for loss of tissue through herbivory was greater under eutrophic nutrient conditions. However, a negative linear relationship was found between grasshopper biomass and water hyacinth performance parameters such as biomass accumulation and leaf production, even under eutrophic conditions. Water hyacinth’s compensatory ability in terms of its potential to mitigate to detrimental effects of insect feeding was dependent on the amount of damage caused by herbivory by the grasshopper. Plant biomass and the competitive ability of water hyacinth in relation to another freefloating aquatic weed species were reduced by C. aquaticum under eutrophic nutrient conditions, in a short space of time. It was also found that grasshopper feeding and characteristics related to their population dynamics such as fecundity and survival were significantly influenced by water nutrient availability and that environmental nutrient availability will influence the control potential of this species should it be released in South Africa. Cornops aquaticum shows promise as a biocontrol agent for water hyacinth but additional factors that were not investigated in this study such as compatibility with the South African climate and the current water hyacinth biocontrol agents need to be combined with these data to make a decision on its release. Possible management options for this species if it is to be introduced into South Africa are discussed.
- Full Text:
- Date Issued: 2009
Cultural historical activity theory, expansive learning and agency in permaculture workplaces
- Authors: Mukute, Mutizwa
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/386474 , vital:68145 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122818"
- Description: This paper reports on how Cultural Historical Activity Theory was used to identify and analyse contradictions; model and implement solutions in the learning and practice of permaculture at one school and its community in Zimbabwe. This is one of three sustainable agriculture workplace learning sites being examined in a wider study on change-oriented learning and sustainability practices (Mukute, 2009). It gives a brief background to permaculture and the School and Colleges Permaculture Programme (SCOPE) in Zimbabwe. The paper focuses on how contradictions were used as sources of learning and development leading to ‘real life expansions’. This demonstrates and reflects on the value of an interventionist research theory and methodology employed in the study to enhance participants’ agency in sustainable agriculture workplaces.
- Full Text:
- Date Issued: 2009
- Authors: Mukute, Mutizwa
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/386474 , vital:68145 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122818"
- Description: This paper reports on how Cultural Historical Activity Theory was used to identify and analyse contradictions; model and implement solutions in the learning and practice of permaculture at one school and its community in Zimbabwe. This is one of three sustainable agriculture workplace learning sites being examined in a wider study on change-oriented learning and sustainability practices (Mukute, 2009). It gives a brief background to permaculture and the School and Colleges Permaculture Programme (SCOPE) in Zimbabwe. The paper focuses on how contradictions were used as sources of learning and development leading to ‘real life expansions’. This demonstrates and reflects on the value of an interventionist research theory and methodology employed in the study to enhance participants’ agency in sustainable agriculture workplaces.
- Full Text:
- Date Issued: 2009
The ambivalent engagement with Christianity in the writing of nineteenth- and early twentieth-century Africans in the Eastern Cape
- Authors: Nxasana, Thulani Litha
- Date: 2009
- Subjects: Authors, African -- South Africa -- Eastern Cape Authors, South African -- 19th century -- Criticism and interpretation Authors, South African -- 20th century -- Criticism and interpretation Soga, Tiyo, 1829-1871 -- Criticism and interpretation Mqhayi, S. E. K. -- Criticism and interpretation Mgqwetho, Nontsizi -- Criticism and interpretation South African literature -- 19th century -- History and criticism South African literature -- 20th century -- History and criticism Christianity and literature Ambivalence in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2195 , http://hdl.handle.net/10962/d1002237
- Description: Until recently much of the literature recording the nineteenth and early twentieth centuries in the Eastern Cape focused purely on frontier conflict and missionary activity, ignoring the evolving culture of the colonized people. But as Somande Fikeni declares, “[i]t is important when celebrating the country’s heritage to look beyond battle sites, monuments and wars and to pay attention to South Africa’s intellectuals and knowledge producers” (quoted in Hollands 4). This is indeed the central purpose of my research. This thesis seeks to examine the influence of Christianity on early South African writing by Africans and the ambivalence with which Christianity is often treated in their work. In South Africa, as elsewhere in Africa, Christianity played a central role in the development of African literature through the influence of mission schools and printing presses. Thus from the outset the development of written literature was inseparable from the spread of Christianity. Nineteenth- and early twentieth-century writing by Africans reflects this: Christian idioms, biblical stories and images colour their work and yet are not employed unthinkingly. Each of the writers whom I will explore has a complex and at times ambivalent relationship with Christianity, and they use religious discourse for a variety of ends, some of them clearly at odds with their origins in the “civilizing mission” of Europe. According to Yunus Momoniat, “Their works . . . are the beginnings of an engagement not only with the world of words on a page, but also with the politics of literacy itself” (1). The subject of this research is three Xhosa writers from the Eastern Cape: the Reverend Tiyo Soga (1829-1871), the renowned novelist and “National Poet” S. E. K. Mqhayi (1875-1945), and the little-known poet Nontsizi Mgqwetho (Dates uknown, writings 1920-1929), who is described by Mbeki as “the most prolific woman Xhosa poet of the twentieth century” (6). The reason for focusing on the Eastern Cape is because the Xhosa “were the first Bantu people to be exposed to Christian proselytising and to receive a literate education” (Gerard 24). As a result much of the early literature in isiXhosa consisted of translations of the Bible and other Christian tracts, and such “improving” texts as Pilgrim’s Progress. In other words, it is in this work that the first roots of the influence of Christianity in southern Africa can be traced.
- Full Text:
- Date Issued: 2009
- Authors: Nxasana, Thulani Litha
- Date: 2009
- Subjects: Authors, African -- South Africa -- Eastern Cape Authors, South African -- 19th century -- Criticism and interpretation Authors, South African -- 20th century -- Criticism and interpretation Soga, Tiyo, 1829-1871 -- Criticism and interpretation Mqhayi, S. E. K. -- Criticism and interpretation Mgqwetho, Nontsizi -- Criticism and interpretation South African literature -- 19th century -- History and criticism South African literature -- 20th century -- History and criticism Christianity and literature Ambivalence in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2195 , http://hdl.handle.net/10962/d1002237
- Description: Until recently much of the literature recording the nineteenth and early twentieth centuries in the Eastern Cape focused purely on frontier conflict and missionary activity, ignoring the evolving culture of the colonized people. But as Somande Fikeni declares, “[i]t is important when celebrating the country’s heritage to look beyond battle sites, monuments and wars and to pay attention to South Africa’s intellectuals and knowledge producers” (quoted in Hollands 4). This is indeed the central purpose of my research. This thesis seeks to examine the influence of Christianity on early South African writing by Africans and the ambivalence with which Christianity is often treated in their work. In South Africa, as elsewhere in Africa, Christianity played a central role in the development of African literature through the influence of mission schools and printing presses. Thus from the outset the development of written literature was inseparable from the spread of Christianity. Nineteenth- and early twentieth-century writing by Africans reflects this: Christian idioms, biblical stories and images colour their work and yet are not employed unthinkingly. Each of the writers whom I will explore has a complex and at times ambivalent relationship with Christianity, and they use religious discourse for a variety of ends, some of them clearly at odds with their origins in the “civilizing mission” of Europe. According to Yunus Momoniat, “Their works . . . are the beginnings of an engagement not only with the world of words on a page, but also with the politics of literacy itself” (1). The subject of this research is three Xhosa writers from the Eastern Cape: the Reverend Tiyo Soga (1829-1871), the renowned novelist and “National Poet” S. E. K. Mqhayi (1875-1945), and the little-known poet Nontsizi Mgqwetho (Dates uknown, writings 1920-1929), who is described by Mbeki as “the most prolific woman Xhosa poet of the twentieth century” (6). The reason for focusing on the Eastern Cape is because the Xhosa “were the first Bantu people to be exposed to Christian proselytising and to receive a literate education” (Gerard 24). As a result much of the early literature in isiXhosa consisted of translations of the Bible and other Christian tracts, and such “improving” texts as Pilgrim’s Progress. In other words, it is in this work that the first roots of the influence of Christianity in southern Africa can be traced.
- Full Text:
- Date Issued: 2009
Movement bahaviour of three South African inshore sparid species in rocky intertidal and shallow subtidal habitats
- Authors: Watt-Pringle, Peter Andrew
- Date: 2009
- Subjects: Sparidae -- South Africa , Diplodus , Sparodon Durbanensis , Fisheries -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5302 , http://hdl.handle.net/10962/d1005147 , Sparidae -- South Africa , Diplodus , Sparodon Durbanensis , Fisheries -- South Africa
- Description: This study investigated the movement behaviour of three inshore South African sparids – blacktail (Diplodus sargus capensis), zebra (Diplodus cervinus hottentotus) and white musselcracker (Sparodon durbanensis), popular inshore fishery species caught in appreciable numbers along much of the South African coast. The first study component examined movements of juveniles in a rocky intertidal nursery area at Schoenmakerskop near Port Elizabeth. Juveniles in a single gully were tagged with Visible Implant Elastomer (VIE) and resighted at the study site on snorkelling gear over a seven-month period. Tagged zebra and musselcracker displayed limited movement between potential low tide refuges, being observed repeatedly in the same gully over the full duration of the study. However, blacktail displayed greater movements and were seen infrequently in the later period of the study, probably having undergone an ontogenetic habitat shift to subtidal areas. There was evidence that blacktail maintain use of their intertidal nursery over high tide, during which the other two species moved into shallower areas adjacent to their low tide refuge. The results of three national tagging programs were analysed to determine the movement patterns of adolescent and adult fishes. The coast-wide ORI-WWF National Voluntary Tagging Program and two dedicated research programs in marine protected areas (MPAs) at De Hoop MPA and Tsitsikamma National Park (TNP) recorded few large-scale movements of tagged adult blacktail, zebra and juvenile musselcracker. High spatial-resolution data from the TNP suggested movements were usually on scales far smaller than one km. Together with long periods at liberty for many recaptured individuals, this suggests these fishes are longterm residents of small home range areas. However, tagged musselcracker over 600 mm forklength (adults) were observed to make large-scale movements, including some in excess of 800 km from Eastern Cape to KwaZulu-Natal waters. Predominantly eastward movements of adults recaptured during the spawning season indicate seasonal spawning migrations that occur in different regions of the coast. These enable the use of prevailing oceanographic currents to disperse eggs and larvae to suitable rocky nursery habitat. The third component of this study made use of high-resolution data on the temporal and spatial distribution of catches by scientific angling in the TNP to examine the daily activity patterns of the study species in relation to diel and tidal cycles, and habitat use. Blacktail capture probability was correlated with the diurnal light cycle, with peaks close to twilight suggesting elevated crepuscular foraging activity. Catches of blacktail, zebra and small musselcracker were correlated with the tidal cycle, foraging peaking over high tide periods. All three species used shallow inshore habitats extensively for foraging, blacktail showing a preference for sandy areas, while zebra and small musselcracker preferred shallow reef. Capture probability of larger musselcracker, however, was unrelated to habitat, possibly evidence of increasing area and habitat use with an ontogenetic change in diet. The lifetime movement patterns of these three species are discussed in relation to conservation measures and their management in South African fisheries. Restricted movement throughout post-settlement life for blacktail and zebra, and during the juvenile phase for musselcracker, makes local populations vulnerable to overexploitation. At present, MPAs probably play an important role in protecting local blacktail and zebra populations from overexploitation, and limited post-settlement movements mean the degree of larval dispersal between protected and adjacent areas will likely determine the effectiveness of MPAs in enhancing fisheries for these species. By contrast, MPAs likely provide recruits to fisheries for musselcracker during ontogenetic movements and dispersal from MPAs during spawning migrations. MPAs only offer partial protection to adult musselcracker populations in the spawning season, but this could nevertheless be significant under high levels of exploitation.
- Full Text:
- Date Issued: 2009
- Authors: Watt-Pringle, Peter Andrew
- Date: 2009
- Subjects: Sparidae -- South Africa , Diplodus , Sparodon Durbanensis , Fisheries -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5302 , http://hdl.handle.net/10962/d1005147 , Sparidae -- South Africa , Diplodus , Sparodon Durbanensis , Fisheries -- South Africa
- Description: This study investigated the movement behaviour of three inshore South African sparids – blacktail (Diplodus sargus capensis), zebra (Diplodus cervinus hottentotus) and white musselcracker (Sparodon durbanensis), popular inshore fishery species caught in appreciable numbers along much of the South African coast. The first study component examined movements of juveniles in a rocky intertidal nursery area at Schoenmakerskop near Port Elizabeth. Juveniles in a single gully were tagged with Visible Implant Elastomer (VIE) and resighted at the study site on snorkelling gear over a seven-month period. Tagged zebra and musselcracker displayed limited movement between potential low tide refuges, being observed repeatedly in the same gully over the full duration of the study. However, blacktail displayed greater movements and were seen infrequently in the later period of the study, probably having undergone an ontogenetic habitat shift to subtidal areas. There was evidence that blacktail maintain use of their intertidal nursery over high tide, during which the other two species moved into shallower areas adjacent to their low tide refuge. The results of three national tagging programs were analysed to determine the movement patterns of adolescent and adult fishes. The coast-wide ORI-WWF National Voluntary Tagging Program and two dedicated research programs in marine protected areas (MPAs) at De Hoop MPA and Tsitsikamma National Park (TNP) recorded few large-scale movements of tagged adult blacktail, zebra and juvenile musselcracker. High spatial-resolution data from the TNP suggested movements were usually on scales far smaller than one km. Together with long periods at liberty for many recaptured individuals, this suggests these fishes are longterm residents of small home range areas. However, tagged musselcracker over 600 mm forklength (adults) were observed to make large-scale movements, including some in excess of 800 km from Eastern Cape to KwaZulu-Natal waters. Predominantly eastward movements of adults recaptured during the spawning season indicate seasonal spawning migrations that occur in different regions of the coast. These enable the use of prevailing oceanographic currents to disperse eggs and larvae to suitable rocky nursery habitat. The third component of this study made use of high-resolution data on the temporal and spatial distribution of catches by scientific angling in the TNP to examine the daily activity patterns of the study species in relation to diel and tidal cycles, and habitat use. Blacktail capture probability was correlated with the diurnal light cycle, with peaks close to twilight suggesting elevated crepuscular foraging activity. Catches of blacktail, zebra and small musselcracker were correlated with the tidal cycle, foraging peaking over high tide periods. All three species used shallow inshore habitats extensively for foraging, blacktail showing a preference for sandy areas, while zebra and small musselcracker preferred shallow reef. Capture probability of larger musselcracker, however, was unrelated to habitat, possibly evidence of increasing area and habitat use with an ontogenetic change in diet. The lifetime movement patterns of these three species are discussed in relation to conservation measures and their management in South African fisheries. Restricted movement throughout post-settlement life for blacktail and zebra, and during the juvenile phase for musselcracker, makes local populations vulnerable to overexploitation. At present, MPAs probably play an important role in protecting local blacktail and zebra populations from overexploitation, and limited post-settlement movements mean the degree of larval dispersal between protected and adjacent areas will likely determine the effectiveness of MPAs in enhancing fisheries for these species. By contrast, MPAs likely provide recruits to fisheries for musselcracker during ontogenetic movements and dispersal from MPAs during spawning migrations. MPAs only offer partial protection to adult musselcracker populations in the spawning season, but this could nevertheless be significant under high levels of exploitation.
- Full Text:
- Date Issued: 2009
A study of employee satisfaction in two manufacturing facilities of General Motors South Africa
- Authors: Matutoane, Leanetse Paul
- Date: 2009
- Subjects: General Motors Corporation -- South Africa -- Port Elizabeth Job satisfaction -- South Africa -- Port Elizabeth Employee motivation -- South Africa -- Port Elizabeth Employee attitude surveys -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:766 , http://hdl.handle.net/10962/d1003887
- Description: Employed individuals spend a majority of their waking time at work. Therefore, within an individual’s working lifetime, most hours will be spent at work. Subsequently, theories abound purporting that humans are hedonistic beings. Considering that on average people spend most of their working lives in a working environment, it then stands to reason that people should endeavor to be satisfied at work if humans are always in pursuit of happiness. The questions arise as thus: what makes people satisfied at work, does being satisfied with the job result in less turnover, and is that the only reason that they would endeavor to prolong their employment, are older employees more satisfied with their jobs than younger employees, is a plant with an older workforce more satisfied than a similar plant with a younger workforce? This study attempts to find an answer to these and other related questions. It was conducted on employees of two plants of an automotive manufacturer based in Port Elizabeth, a town in the Eastern Cape province of South Africa. The Job Descriptive Index (JDI) was used to collect the feelings of 92 employees in different shops and analyzed to check for differences in satisfaction levels. No significant differences were found between the plants, shops and age categories surveyed.
- Full Text:
- Date Issued: 2009
- Authors: Matutoane, Leanetse Paul
- Date: 2009
- Subjects: General Motors Corporation -- South Africa -- Port Elizabeth Job satisfaction -- South Africa -- Port Elizabeth Employee motivation -- South Africa -- Port Elizabeth Employee attitude surveys -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:766 , http://hdl.handle.net/10962/d1003887
- Description: Employed individuals spend a majority of their waking time at work. Therefore, within an individual’s working lifetime, most hours will be spent at work. Subsequently, theories abound purporting that humans are hedonistic beings. Considering that on average people spend most of their working lives in a working environment, it then stands to reason that people should endeavor to be satisfied at work if humans are always in pursuit of happiness. The questions arise as thus: what makes people satisfied at work, does being satisfied with the job result in less turnover, and is that the only reason that they would endeavor to prolong their employment, are older employees more satisfied with their jobs than younger employees, is a plant with an older workforce more satisfied than a similar plant with a younger workforce? This study attempts to find an answer to these and other related questions. It was conducted on employees of two plants of an automotive manufacturer based in Port Elizabeth, a town in the Eastern Cape province of South Africa. The Job Descriptive Index (JDI) was used to collect the feelings of 92 employees in different shops and analyzed to check for differences in satisfaction levels. No significant differences were found between the plants, shops and age categories surveyed.
- Full Text:
- Date Issued: 2009
Determinism and reactive attitudes: reflections on our alleged unrenounceable commitments
- Authors: Kelland, Lindsay-Ann
- Date: 2009
- Subjects: Free will and determinism Responsibility
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2713 , http://hdl.handle.net/10962/d1002843
- Description: There seems to exist a tension between our metaphysical and phenomenological commitments in the free will debate. On the one hand, I argue that at the metaphysical level we cannot coherently defend the belief that we are morally responsible in the sense that we deserve to be rewarded and punished for our actions, where desert-entailing moral responsibility is the primary understanding of moral responsibility presupposed in the free will debate. I argue that we are responsible for our actions but only in the weaker sense, termed ‘attributability’ by Gary Watson. On the other hand, we are allegedly unrenounceably committed at the phenomenological level to conceiving of, and treating, ourselves and one another as morally responsible beings in the desert-entailing sense. P. F. Strawson famously defends this claim in his seminal work, ‘Freedom and Resentment’. In my thesis I will set out this tension by exploring both commitments in turn. I then aim to show that the tension can be dissolved by arguing, contra P. F. Strawson, that our phenomenological commitment is not in fact unrenounceable. The dissolution of this tension entails, I argue, that we must examine our conception of self and other. We must explore the implications of adopting a position which denies that we are morally responsible beings for our life-hopes, personal feelings, inter-personal relationships and projects. Most importantly, I argue that we must renounce our current retributive condemnatory practices which are based on the unjustified belief that we are morally responsible beings.
- Full Text:
- Date Issued: 2009
- Authors: Kelland, Lindsay-Ann
- Date: 2009
- Subjects: Free will and determinism Responsibility
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2713 , http://hdl.handle.net/10962/d1002843
- Description: There seems to exist a tension between our metaphysical and phenomenological commitments in the free will debate. On the one hand, I argue that at the metaphysical level we cannot coherently defend the belief that we are morally responsible in the sense that we deserve to be rewarded and punished for our actions, where desert-entailing moral responsibility is the primary understanding of moral responsibility presupposed in the free will debate. I argue that we are responsible for our actions but only in the weaker sense, termed ‘attributability’ by Gary Watson. On the other hand, we are allegedly unrenounceably committed at the phenomenological level to conceiving of, and treating, ourselves and one another as morally responsible beings in the desert-entailing sense. P. F. Strawson famously defends this claim in his seminal work, ‘Freedom and Resentment’. In my thesis I will set out this tension by exploring both commitments in turn. I then aim to show that the tension can be dissolved by arguing, contra P. F. Strawson, that our phenomenological commitment is not in fact unrenounceable. The dissolution of this tension entails, I argue, that we must examine our conception of self and other. We must explore the implications of adopting a position which denies that we are morally responsible beings for our life-hopes, personal feelings, inter-personal relationships and projects. Most importantly, I argue that we must renounce our current retributive condemnatory practices which are based on the unjustified belief that we are morally responsible beings.
- Full Text:
- Date Issued: 2009
A grid based approach for the control and recall of the properties of IEEE 1394 audio devices
- Authors: Foulkes, Philip James
- Date: 2009
- Subjects: IEEE 1394 (Standard) , Computer sound processing , Digital communications , Local area networks (Computer networks) , Sound -- Recording and reproducing -- Digital techniques , Computational grids (Computer systems)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4594 , http://hdl.handle.net/10962/d1004836 , IEEE 1394 (Standard) , Computer sound processing , Digital communications , Local area networks (Computer networks) , Sound -- Recording and reproducing -- Digital techniques , Computational grids (Computer systems)
- Description: The control of modern audio studios is complex. Audio mixing desks have grown to the point where they contain thousands of parameters. The control surfaces of these devices do not reflect the routing and signal processing capabilities that the devices are capable of. Software audio mixing desk editors have been developed that allow for the remote control of these devices, but their graphical user interfaces retain the complexities of the audio mixing desk that they represent. In this thesis, we propose a grid approach to audio mixing. The developed grid audio mixing desk editor represents an audio mixing desk as a series of graphical routing matrices. These routing matrices expose the various signal processing points and signal flows that exist within an audio mixing desk. The routing matrices allow for audio signals to be routed within the device, and allow for the device’s parameters to be adjusted by selecting the appropriate signal processing points. With the use of the programming interfaces that are defined as part of the Studio Connections – Total Recall SDK, the audio mixing desk editor was integrated with compatible DAW applications to provide persistence of audio mixing desk parameter states. Many audio studios currently use digital networks to connect audio devices together. Audio and control signals are patched between devices through the use of software patchbays that run on computers. We propose a double grid-based FireWire patchbay aimed to simplify the patching of signals between audio devices on a FireWire network. The FireWire patchbay was implemented in such a way such that it can host software device editors that are Studio Connections compatible. This has allowed software device editors to be associated with the devices that are represented on the FireWire patchbay, thus allowing for studio wide control from a single application. The double grid-based patchbay was implemented such that it can be hosted by compatible DAW applications. Through this, the double grid-based patchbay application is able to provide the DAW application with the state of the parameters of the devices in a studio, as well as the connections between them. The DAW application may save this state data to its native song files. This state data may be passed back to the double grid-based patchbay when the song file is reloaded at a later stage. This state data may then be used by the patchbay to restore the parameters of the patchbay and its device editors to a previous state. This restored state may then be transferred to the hardware devices being represented by the patchbay.
- Full Text:
- Date Issued: 2009
- Authors: Foulkes, Philip James
- Date: 2009
- Subjects: IEEE 1394 (Standard) , Computer sound processing , Digital communications , Local area networks (Computer networks) , Sound -- Recording and reproducing -- Digital techniques , Computational grids (Computer systems)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4594 , http://hdl.handle.net/10962/d1004836 , IEEE 1394 (Standard) , Computer sound processing , Digital communications , Local area networks (Computer networks) , Sound -- Recording and reproducing -- Digital techniques , Computational grids (Computer systems)
- Description: The control of modern audio studios is complex. Audio mixing desks have grown to the point where they contain thousands of parameters. The control surfaces of these devices do not reflect the routing and signal processing capabilities that the devices are capable of. Software audio mixing desk editors have been developed that allow for the remote control of these devices, but their graphical user interfaces retain the complexities of the audio mixing desk that they represent. In this thesis, we propose a grid approach to audio mixing. The developed grid audio mixing desk editor represents an audio mixing desk as a series of graphical routing matrices. These routing matrices expose the various signal processing points and signal flows that exist within an audio mixing desk. The routing matrices allow for audio signals to be routed within the device, and allow for the device’s parameters to be adjusted by selecting the appropriate signal processing points. With the use of the programming interfaces that are defined as part of the Studio Connections – Total Recall SDK, the audio mixing desk editor was integrated with compatible DAW applications to provide persistence of audio mixing desk parameter states. Many audio studios currently use digital networks to connect audio devices together. Audio and control signals are patched between devices through the use of software patchbays that run on computers. We propose a double grid-based FireWire patchbay aimed to simplify the patching of signals between audio devices on a FireWire network. The FireWire patchbay was implemented in such a way such that it can host software device editors that are Studio Connections compatible. This has allowed software device editors to be associated with the devices that are represented on the FireWire patchbay, thus allowing for studio wide control from a single application. The double grid-based patchbay was implemented such that it can be hosted by compatible DAW applications. Through this, the double grid-based patchbay application is able to provide the DAW application with the state of the parameters of the devices in a studio, as well as the connections between them. The DAW application may save this state data to its native song files. This state data may be passed back to the double grid-based patchbay when the song file is reloaded at a later stage. This state data may then be used by the patchbay to restore the parameters of the patchbay and its device editors to a previous state. This restored state may then be transferred to the hardware devices being represented by the patchbay.
- Full Text:
- Date Issued: 2009
Immobilization of catalyst in a wall-coated micro-structured reactor for gas/liquid oxidation of p-cymene
- Authors: Makgwane, Peter Ramashadi
- Date: 2009
- Subjects: Oxidation , Cymene
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:10389 , http://hdl.handle.net/10948/1182 , Oxidation , Cymene
- Description: The selective, liquid phase oxidation of p-cymene is an important synthetic route for the production of p-cresol via the tertiary cymene hydroperoxide (TCHP). The industrial-scale oxidation process is characterised by slow oxidation rates due to limitations in the mass transfer of oxidant (gaseous oxygen) into the liquid phase. However, like all other autoxidation reactions, the oxidation reaction is exothermic, following the typical free radical autoxidation reaction mechanism, which implies that careful temperature control is critical in order to prevent the further reaction of the initially formed hydroperoxide species. In the presence of metal catalysts, the limiting oxidation rate is the transfer of oxygen from the gas to liquid boundary interface. As a result, low product yields and poor productivity space-time yield are typically experienced. At high substrate conversions, by-products resulting from the decomposition of the formed hydroperoxides predominate. For this reason, the conversion of substrate is restricted to preserve the TCHP selectivity. The slow rates in industrial-scale p-cymene oxidations results in long oxidation times, typically 8-12 h. Substrate conversions are typically between 15-20 percent, and the TCHP selectivity ranges between 65-70 percent. The work described in this thesis concerns the oxidation of p-cymene in a microstructured falling film reactor (FFMSR). These reactor systems facilitate chemical reactors to have high mass and heat transfer rates because of high surface area-to-volume ratios. Due to their small internal volumes, these reactors are inherently safe to operate. These properties were exploited to improve the p-cymene oxidation rate and, consequently, the space-time yield. In order to evaluate the suitability of vanadium phosphate oxide (VPO) catalysts for use as supported catalyst in the FFMSR, different catalysts prepared from VOHPO4∙0.5H2O and VO(H2PO4)2 precursors was first evaluated for the oxidation of p-cymene in a well-stirred batch reactor. The results of the two activated catalysts, (VO)2P2O7 and VO(PO3)2 when used as powders in their pure form, showed a significant improvement in p-cymene oxidation rates with conversions up to 40 percent in 3-4 h reaction time with a TCHP selectivity of 75-80 percent. The (VO)2P2O7 catalyst showed better oxidation rates and selectivity when compared to the VO(PO3)2 catalyst obtained from the VO(H2PO4)2 precursor. The (VO)2P2O7 catalyst was supported on a stainless steel plate and the coated plate used to study the long-term stability and catalytic perfornance of the catalyst during p-cymene oxidations in a batch reactor. Comparable oxidation rates and TCHP selectivity were obtained with the stainless steel coated VPO catalyst when compared to the “free powder” (VO)2P2O7 catalyst. The results also showed that the stainless steel coated catalyst displays a slow, yet significant deactivation over extended reaction periods (250 h onstream). Characterization of the exposed (VO)2P2O7 catalyst to p-cymene oxidation conditions by powder XRD, SEM and TGA-MS showed that (VO)2P2O7 phase undergoes structural transformation back to VOHPO4∙0.5H2O phase over time. The (VO)2P2O7/-Al2O3 catalyst was used to coat the micro-channel reaction plates of the FFMSR. Both uncoated and coated micro-channel reaction plates were evaluated in the FFMSR for the oxidation of p-cymene. The FFMSR showed effective improvement of oxidation rates in terms of productivity space-time-yield at comparable batch p-cymene conversions. A Typical 10 percent conversion in catalysed batch oxidations at 1-2 h reaction time was achieved in few seconds (19 s) reaction time in FFMSR. The comparison of uncoated (i.e. uncatalysed) and coated (i.e. catalysed) FFMSR oxidations showed slight differences in oxidation rates. No clear explanation could be established with the present results for the observed same behaviour. However, the insufficient contact time between the gas and liquid reactants with the wall-coated solid catalyst is one of the possible causes for the observed behaviour of the coated and uncoated micro-channel plates. A simple developed kinetic model was used to confirm the obtained batch oxidation results using cumene as probe compound due to its similarity to p-cumene oxidation and extensive studied kinetics. With the estimated K values and available rate constants from literature, it was possible to predict the conversions in a batch reactor at the same typical micro-structured reactor residence time (i.e. of 19 s). The predicted conversions in the batch reactor were less than 0.1 percent even at harsh conditions such as 170 oC when compared to about 10 percent achieved in the micro-structured reactor at the same reaction temperature, reactants concentration and reaction time of 19 s. This difference in the reactor systems performance indicates the unique advantages offered by micro-structured reactors (e.g. improved mass transfer, temperature management and high surface-to-volume ratios) to perform typical gas/liquid mass transfer limited reactions such as cumene and p-cymene autoxidations.
- Full Text:
- Date Issued: 2009
- Authors: Makgwane, Peter Ramashadi
- Date: 2009
- Subjects: Oxidation , Cymene
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:10389 , http://hdl.handle.net/10948/1182 , Oxidation , Cymene
- Description: The selective, liquid phase oxidation of p-cymene is an important synthetic route for the production of p-cresol via the tertiary cymene hydroperoxide (TCHP). The industrial-scale oxidation process is characterised by slow oxidation rates due to limitations in the mass transfer of oxidant (gaseous oxygen) into the liquid phase. However, like all other autoxidation reactions, the oxidation reaction is exothermic, following the typical free radical autoxidation reaction mechanism, which implies that careful temperature control is critical in order to prevent the further reaction of the initially formed hydroperoxide species. In the presence of metal catalysts, the limiting oxidation rate is the transfer of oxygen from the gas to liquid boundary interface. As a result, low product yields and poor productivity space-time yield are typically experienced. At high substrate conversions, by-products resulting from the decomposition of the formed hydroperoxides predominate. For this reason, the conversion of substrate is restricted to preserve the TCHP selectivity. The slow rates in industrial-scale p-cymene oxidations results in long oxidation times, typically 8-12 h. Substrate conversions are typically between 15-20 percent, and the TCHP selectivity ranges between 65-70 percent. The work described in this thesis concerns the oxidation of p-cymene in a microstructured falling film reactor (FFMSR). These reactor systems facilitate chemical reactors to have high mass and heat transfer rates because of high surface area-to-volume ratios. Due to their small internal volumes, these reactors are inherently safe to operate. These properties were exploited to improve the p-cymene oxidation rate and, consequently, the space-time yield. In order to evaluate the suitability of vanadium phosphate oxide (VPO) catalysts for use as supported catalyst in the FFMSR, different catalysts prepared from VOHPO4∙0.5H2O and VO(H2PO4)2 precursors was first evaluated for the oxidation of p-cymene in a well-stirred batch reactor. The results of the two activated catalysts, (VO)2P2O7 and VO(PO3)2 when used as powders in their pure form, showed a significant improvement in p-cymene oxidation rates with conversions up to 40 percent in 3-4 h reaction time with a TCHP selectivity of 75-80 percent. The (VO)2P2O7 catalyst showed better oxidation rates and selectivity when compared to the VO(PO3)2 catalyst obtained from the VO(H2PO4)2 precursor. The (VO)2P2O7 catalyst was supported on a stainless steel plate and the coated plate used to study the long-term stability and catalytic perfornance of the catalyst during p-cymene oxidations in a batch reactor. Comparable oxidation rates and TCHP selectivity were obtained with the stainless steel coated VPO catalyst when compared to the “free powder” (VO)2P2O7 catalyst. The results also showed that the stainless steel coated catalyst displays a slow, yet significant deactivation over extended reaction periods (250 h onstream). Characterization of the exposed (VO)2P2O7 catalyst to p-cymene oxidation conditions by powder XRD, SEM and TGA-MS showed that (VO)2P2O7 phase undergoes structural transformation back to VOHPO4∙0.5H2O phase over time. The (VO)2P2O7/-Al2O3 catalyst was used to coat the micro-channel reaction plates of the FFMSR. Both uncoated and coated micro-channel reaction plates were evaluated in the FFMSR for the oxidation of p-cymene. The FFMSR showed effective improvement of oxidation rates in terms of productivity space-time-yield at comparable batch p-cymene conversions. A Typical 10 percent conversion in catalysed batch oxidations at 1-2 h reaction time was achieved in few seconds (19 s) reaction time in FFMSR. The comparison of uncoated (i.e. uncatalysed) and coated (i.e. catalysed) FFMSR oxidations showed slight differences in oxidation rates. No clear explanation could be established with the present results for the observed same behaviour. However, the insufficient contact time between the gas and liquid reactants with the wall-coated solid catalyst is one of the possible causes for the observed behaviour of the coated and uncoated micro-channel plates. A simple developed kinetic model was used to confirm the obtained batch oxidation results using cumene as probe compound due to its similarity to p-cumene oxidation and extensive studied kinetics. With the estimated K values and available rate constants from literature, it was possible to predict the conversions in a batch reactor at the same typical micro-structured reactor residence time (i.e. of 19 s). The predicted conversions in the batch reactor were less than 0.1 percent even at harsh conditions such as 170 oC when compared to about 10 percent achieved in the micro-structured reactor at the same reaction temperature, reactants concentration and reaction time of 19 s. This difference in the reactor systems performance indicates the unique advantages offered by micro-structured reactors (e.g. improved mass transfer, temperature management and high surface-to-volume ratios) to perform typical gas/liquid mass transfer limited reactions such as cumene and p-cymene autoxidations.
- Full Text:
- Date Issued: 2009
Stronger induction of callose deposition in barley by Russian wheat aphid than bird cherry-oat aphid is not associated with differences in callose synthase or ≤-1,3-glucanase expression
- Saheed, Sefiu A, Cierlik, Izabela, Larsson, Kristina A E, Delp, Gabriele, Bradley, Graeme, Jonsson, Lisbeth M V, Botha, Christiaan E J
- Authors: Saheed, Sefiu A , Cierlik, Izabela , Larsson, Kristina A E , Delp, Gabriele , Bradley, Graeme , Jonsson, Lisbeth M V , Botha, Christiaan E J
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6542 , http://hdl.handle.net/10962/d1005984
- Description: The effects of infestation by the bird cherry-oat aphid (BCA), (Rhopalosiphum padi L) and the Russian wheat aphid (RWA) (Diuraphis noxia Mordvilko) on callose deposition and gene expression related to callose accumulation were investigated in barley (Hordeum vulgare L. cv. Clipper). The BCA, which gives no visible symptoms, induced very limited callose deposition, even after 14 days of infestation. In contrast, RWA, which causes chlorosis, white and yellow streaking and leaf rolling, induced callose accumulation already after 24h in longitudinal leaf veins. The deposition was pronounced after 72 h, progressing during 7 and 14 days of infestation. In RWA-infested source leaves, callose was also induced in longitudinal veins basipetal to the aphid-infested tissue, whereas in sink leaves, more callose deposition was found above the feeding sites. Nine putative callose synthase genes were identified in a data base search, of which eight were expressed in the leaves, but with similar level of expression in control and aphid-infested tissue. Four out of 12 examined β-1,3-glucanases were expressed in the leaves, and three of them were up-regulated in aphid-infested tissue. They were all more strongly induced by RWA than BCA. The results suggest that callose accumulation may be partly responsible for the symptoms resulting from RWA feeding and that a callose-inducing signal may be transported in the phloem. Furthermore it is concluded that the absence of callose deposition in BCA-infested leaves is not due to a stronger induction of callose-degrading β-1,3-glucanases in this tissue, as compared to RWA-infested leaves.
- Full Text:
- Date Issued: 2009
- Authors: Saheed, Sefiu A , Cierlik, Izabela , Larsson, Kristina A E , Delp, Gabriele , Bradley, Graeme , Jonsson, Lisbeth M V , Botha, Christiaan E J
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6542 , http://hdl.handle.net/10962/d1005984
- Description: The effects of infestation by the bird cherry-oat aphid (BCA), (Rhopalosiphum padi L) and the Russian wheat aphid (RWA) (Diuraphis noxia Mordvilko) on callose deposition and gene expression related to callose accumulation were investigated in barley (Hordeum vulgare L. cv. Clipper). The BCA, which gives no visible symptoms, induced very limited callose deposition, even after 14 days of infestation. In contrast, RWA, which causes chlorosis, white and yellow streaking and leaf rolling, induced callose accumulation already after 24h in longitudinal leaf veins. The deposition was pronounced after 72 h, progressing during 7 and 14 days of infestation. In RWA-infested source leaves, callose was also induced in longitudinal veins basipetal to the aphid-infested tissue, whereas in sink leaves, more callose deposition was found above the feeding sites. Nine putative callose synthase genes were identified in a data base search, of which eight were expressed in the leaves, but with similar level of expression in control and aphid-infested tissue. Four out of 12 examined β-1,3-glucanases were expressed in the leaves, and three of them were up-regulated in aphid-infested tissue. They were all more strongly induced by RWA than BCA. The results suggest that callose accumulation may be partly responsible for the symptoms resulting from RWA feeding and that a callose-inducing signal may be transported in the phloem. Furthermore it is concluded that the absence of callose deposition in BCA-infested leaves is not due to a stronger induction of callose-degrading β-1,3-glucanases in this tissue, as compared to RWA-infested leaves.
- Full Text:
- Date Issued: 2009
Obstacles faced by news journalists in investigative reporting: analysis of four Botswana newspapers, June 2008 - October 2008
- Authors: Pule, Kediretswe
- Date: 2009
- Subjects: Investigative reporting , Journalism -- Political aspects , Journalists -- Legal status, laws, etc
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8398 , http://hdl.handle.net/10948/869 , Investigative reporting , Journalism -- Political aspects , Journalists -- Legal status, laws, etc
- Description: In this research study, the researcher investigates obstacles faced by news journalists in investigative journalism in a democracy as experienced in Botswana. Investigative journalism and democracy have a symbiotic relationship. This relationship serves to make the public sensitive about, and aware of, injustices and undemocratic practices and it could, ultimately, contribute significantly to the process of democratization (Faure 2005: 155). Unfortunately, in their endeavor to keep up with the ethos of investigative journalism, journalists meet obstacles that range from legal to financial issues. The author investigates those factors that reporters in Botswana rate as having the greatest impact on their investigative efforts. The study also assesses the attitudes of journalists in the country towards the roles and responsibilities of the fourth estate, which supports investigative reporting. Investigative journalism is centered on disclosure, described by six elements: public interest, theme, accuracy, follow-up reports, consequences and questioning the status quo (Faure 2005:160; Marron 1995:1). The researcher interrogated the current practice of investigative journalism in newsrooms in the Botswana context, by means of a self-administered questionnaire. A cumulative sum of scores of each rank order for each obstacle was used to observe the one rated the most impeding by Botswana journalists. Elementary descriptive statistics in the form of percentages were used to assess attitudes of Botswana journalists towards investigative journalism. The same method was used to assess the proportion of investigative stories in four sampled Botswana newspapers. The contents of the respective newspapers were assessed against the five elements of investigative reporting that include: theme, public interest, questioning the status quo, accuracy, follow-up reports and consequences.
- Full Text:
- Date Issued: 2009
- Authors: Pule, Kediretswe
- Date: 2009
- Subjects: Investigative reporting , Journalism -- Political aspects , Journalists -- Legal status, laws, etc
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8398 , http://hdl.handle.net/10948/869 , Investigative reporting , Journalism -- Political aspects , Journalists -- Legal status, laws, etc
- Description: In this research study, the researcher investigates obstacles faced by news journalists in investigative journalism in a democracy as experienced in Botswana. Investigative journalism and democracy have a symbiotic relationship. This relationship serves to make the public sensitive about, and aware of, injustices and undemocratic practices and it could, ultimately, contribute significantly to the process of democratization (Faure 2005: 155). Unfortunately, in their endeavor to keep up with the ethos of investigative journalism, journalists meet obstacles that range from legal to financial issues. The author investigates those factors that reporters in Botswana rate as having the greatest impact on their investigative efforts. The study also assesses the attitudes of journalists in the country towards the roles and responsibilities of the fourth estate, which supports investigative reporting. Investigative journalism is centered on disclosure, described by six elements: public interest, theme, accuracy, follow-up reports, consequences and questioning the status quo (Faure 2005:160; Marron 1995:1). The researcher interrogated the current practice of investigative journalism in newsrooms in the Botswana context, by means of a self-administered questionnaire. A cumulative sum of scores of each rank order for each obstacle was used to observe the one rated the most impeding by Botswana journalists. Elementary descriptive statistics in the form of percentages were used to assess attitudes of Botswana journalists towards investigative journalism. The same method was used to assess the proportion of investigative stories in four sampled Botswana newspapers. The contents of the respective newspapers were assessed against the five elements of investigative reporting that include: theme, public interest, questioning the status quo, accuracy, follow-up reports and consequences.
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- Date Issued: 2009