Psychological resilience: the role of unconscious and conscious coping strategies in the mediation of stress in high risk occupational contexts
- Authors: Alexander, Debra Geraldine
- Date: 2002
- Subjects: Hazardous occupations , Teachers -- South Africa -- Job stress , Police -- South Africa -- Job stress , Emergency medical personnel -- South Africa -- Job stress , Stress (Psychology)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3092 , http://hdl.handle.net/10962/d1003059 , Hazardous occupations , Teachers -- South Africa -- Job stress , Police -- South Africa -- Job stress , Emergency medical personnel -- South Africa -- Job stress , Stress (Psychology)
- Description: This study investigates the role of unconscious and conscious coping strategies in the mediation of stress in high risk occupational contexts. The Social Readjustment Rating Scale, the Multidimensional Coping Inventory and the Defense Style Questionnaires were completed by 194 police, ambulance and teaching personnel. A sample of 37 teachers served as a non high risk occupation control group. Descriptive statistics, regression analysis, analysis of variance, analysis of difference and principal component analysis were performed on the data. Results indicated minimal significant between group differences. Within group variances were yielded. A minor relationship between levels of stress and usage of positive and negative mechanisms was observed. The significance of these findings is discussed and recommendations made for further study.
- Full Text:
- Date Issued: 2002
- Authors: Alexander, Debra Geraldine
- Date: 2002
- Subjects: Hazardous occupations , Teachers -- South Africa -- Job stress , Police -- South Africa -- Job stress , Emergency medical personnel -- South Africa -- Job stress , Stress (Psychology)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3092 , http://hdl.handle.net/10962/d1003059 , Hazardous occupations , Teachers -- South Africa -- Job stress , Police -- South Africa -- Job stress , Emergency medical personnel -- South Africa -- Job stress , Stress (Psychology)
- Description: This study investigates the role of unconscious and conscious coping strategies in the mediation of stress in high risk occupational contexts. The Social Readjustment Rating Scale, the Multidimensional Coping Inventory and the Defense Style Questionnaires were completed by 194 police, ambulance and teaching personnel. A sample of 37 teachers served as a non high risk occupation control group. Descriptive statistics, regression analysis, analysis of variance, analysis of difference and principal component analysis were performed on the data. Results indicated minimal significant between group differences. Within group variances were yielded. A minor relationship between levels of stress and usage of positive and negative mechanisms was observed. The significance of these findings is discussed and recommendations made for further study.
- Full Text:
- Date Issued: 2002
Removal and recovery of gold and platinum from aqueous solutions utilising the non-viable biomass Asolla filiculoides
- Authors: Antunes, Ana Paula Martins
- Date: 2002
- Subjects: Azolla filiculoides Metal wastes -- Recycling Gold -- Recycling Platinum -- Recycling
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3894 , http://hdl.handle.net/10962/d1003726
- Description: Waste water from the mining industry is generally extremely complex and contains numerous species which influence the adsorption of the metals to any biomass. A variety of factors need to be addressed before treatment is considered viable. It is also beneficial to establish the binding characteristics of the metal of interest to maximise its interaction with the biomass to be utilised. Azalia filiculaides was investigated in the adsorption of gold(III), lead(II), iron(ID), copper(II) and platinum (IV). In batch studies, the optimum biomass and initial gold(III) concentrations were found to be 5 gIL and 8 mgIL respectively. The adsorption of gold(ID) is principally pH-dependent with optimal removal at pH 2. Lead(II), iron(III) and copper(II) did not compete with gold(III) adsorption under equimolar and simulated effluent conditions. Halides, with increasing affinity for gold (chloride < bromide < iodide), can affect gold uptake with the soft base, iodide, exhibiting the most inhibition (25%) and the hard base, chloride, O%. Mercaptoethanol (soft base) showed no interference in gold(III) adsorption while the presence of sulphate (hard base) and sulphite (borderline base) showed that concentrations in excess of 1 0 mM may adversely affect gold(ill) uptake, most likely due to competition for cationic sites on the biomass. Column studies, better suited to high volume treatment, indicated that a flow-rate of 5 mL/min and an initial gold(ill) concentration of 5 mgIL was optimal. Competitive effects between lead, iron, copper and gold again showed little or no interference. The halides, chloride, bromide and iodide, affect gold(ill) uptake similarly to the batch studies, while the bases mercaptoethanol and sulphate minimally affect gold(III) binding with sulphite severely hampering adsorption (70% inhibition). To optimise gold desorption, preliminary batch studies indicated that a ratio of 1:1 of adsorbentdesorbent was optimal, whilst gas purging of thiourea with oxygen, air and nitrogen decreased gold elution in proportion to decreased amounts of oxygen. A series of desorbents were utilised, in column studies, to optimise and determine the speciation of bound gold. The presence of an oxidant with thiourea enhanced desorption greater than 3 fold when compared with thiourea alone. Thiourea desorption studies, aided by the oxidant, suggest that gold is present in the + I and 0 oxidation states. Ultimately thiourea, perchloric acid and hydrochloric acid was found to be the most optimal elutant for gold (J 00% recovery). For selective metal recovery oflead and copper, pre-washing the plant material with water, utilising an acid (0.3 M nitric acid), pumping in an up-flow mode, and recycling the desorbent six times was found to be optimal elutant for gold (J 00% recovery). Cost analysis of utilising elutant versus incinerating the biomass for gold recovery indicated the latter as the most economical. Over a 5 cycle adsorption and desorption series, acid desorption before each adsorption cycle was found to result in greater than 92% desorption for lead and 96% for copper. Gold recovery was 97% with incineration. A preliminary study with gold effluent (Mine C) indicated that nickel and sulphate was removed in batch and column studies. Gold removal was found to be 100% and 4% in batch and column studies respectively. Adsorption of gold in the effluent study was accompanied by the release ofHt. Modifying the plant material with various reagents failed to identify the primary binding sites and the role of polysaccharides, proteins and lipids in gold(ill) uptake. The mode of gold binding is suggested as being initially ionic, this is very rapid, with the interaction of the anionic complex, [AuCI₄]". with the cationic biomass (PH 2). This eventually leads to the displacement of the chloride ligand(s) initiating covalent binding. Spectral studies of the chemical interaction between gold and the representative tannins indicated the protonated hydroxy groups to be responsible. All evidence suggests that the binding mechanisms of gold are not simple. Preliminary adsorption studies of platinum by Azalia filiculaides were conducted. Batch studies indicated that J gIL biomass concentration, initial platinum concentration of 20 mgIL and pH 2 are optimal, while the column studies indicated a flow-rate of! 0 rnL/min and initial platinum concentration of 20 mgIL as optimal. In the platinum effluent study, platinum showed a removal of 23 % and 2 J % for the batch and column studies respectively. Again adsorption was accompanied by //' release. Azalia filiculaides demonstrated its feasibility in the removal of gold and platinum from simulated as well as waste water solutions. Its potential viability as a biosorbent was demonstrated by the high recovery from synthetic solutions of greater than 99% for gold (2-10 mgIL), and greater than 89% for platinum (20 mgIL).
- Full Text:
- Date Issued: 2002
- Authors: Antunes, Ana Paula Martins
- Date: 2002
- Subjects: Azolla filiculoides Metal wastes -- Recycling Gold -- Recycling Platinum -- Recycling
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3894 , http://hdl.handle.net/10962/d1003726
- Description: Waste water from the mining industry is generally extremely complex and contains numerous species which influence the adsorption of the metals to any biomass. A variety of factors need to be addressed before treatment is considered viable. It is also beneficial to establish the binding characteristics of the metal of interest to maximise its interaction with the biomass to be utilised. Azalia filiculaides was investigated in the adsorption of gold(III), lead(II), iron(ID), copper(II) and platinum (IV). In batch studies, the optimum biomass and initial gold(III) concentrations were found to be 5 gIL and 8 mgIL respectively. The adsorption of gold(ID) is principally pH-dependent with optimal removal at pH 2. Lead(II), iron(III) and copper(II) did not compete with gold(III) adsorption under equimolar and simulated effluent conditions. Halides, with increasing affinity for gold (chloride < bromide < iodide), can affect gold uptake with the soft base, iodide, exhibiting the most inhibition (25%) and the hard base, chloride, O%. Mercaptoethanol (soft base) showed no interference in gold(III) adsorption while the presence of sulphate (hard base) and sulphite (borderline base) showed that concentrations in excess of 1 0 mM may adversely affect gold(ill) uptake, most likely due to competition for cationic sites on the biomass. Column studies, better suited to high volume treatment, indicated that a flow-rate of 5 mL/min and an initial gold(ill) concentration of 5 mgIL was optimal. Competitive effects between lead, iron, copper and gold again showed little or no interference. The halides, chloride, bromide and iodide, affect gold(ill) uptake similarly to the batch studies, while the bases mercaptoethanol and sulphate minimally affect gold(III) binding with sulphite severely hampering adsorption (70% inhibition). To optimise gold desorption, preliminary batch studies indicated that a ratio of 1:1 of adsorbentdesorbent was optimal, whilst gas purging of thiourea with oxygen, air and nitrogen decreased gold elution in proportion to decreased amounts of oxygen. A series of desorbents were utilised, in column studies, to optimise and determine the speciation of bound gold. The presence of an oxidant with thiourea enhanced desorption greater than 3 fold when compared with thiourea alone. Thiourea desorption studies, aided by the oxidant, suggest that gold is present in the + I and 0 oxidation states. Ultimately thiourea, perchloric acid and hydrochloric acid was found to be the most optimal elutant for gold (J 00% recovery). For selective metal recovery oflead and copper, pre-washing the plant material with water, utilising an acid (0.3 M nitric acid), pumping in an up-flow mode, and recycling the desorbent six times was found to be optimal elutant for gold (J 00% recovery). Cost analysis of utilising elutant versus incinerating the biomass for gold recovery indicated the latter as the most economical. Over a 5 cycle adsorption and desorption series, acid desorption before each adsorption cycle was found to result in greater than 92% desorption for lead and 96% for copper. Gold recovery was 97% with incineration. A preliminary study with gold effluent (Mine C) indicated that nickel and sulphate was removed in batch and column studies. Gold removal was found to be 100% and 4% in batch and column studies respectively. Adsorption of gold in the effluent study was accompanied by the release ofHt. Modifying the plant material with various reagents failed to identify the primary binding sites and the role of polysaccharides, proteins and lipids in gold(ill) uptake. The mode of gold binding is suggested as being initially ionic, this is very rapid, with the interaction of the anionic complex, [AuCI₄]". with the cationic biomass (PH 2). This eventually leads to the displacement of the chloride ligand(s) initiating covalent binding. Spectral studies of the chemical interaction between gold and the representative tannins indicated the protonated hydroxy groups to be responsible. All evidence suggests that the binding mechanisms of gold are not simple. Preliminary adsorption studies of platinum by Azalia filiculaides were conducted. Batch studies indicated that J gIL biomass concentration, initial platinum concentration of 20 mgIL and pH 2 are optimal, while the column studies indicated a flow-rate of! 0 rnL/min and initial platinum concentration of 20 mgIL as optimal. In the platinum effluent study, platinum showed a removal of 23 % and 2 J % for the batch and column studies respectively. Again adsorption was accompanied by //' release. Azalia filiculaides demonstrated its feasibility in the removal of gold and platinum from simulated as well as waste water solutions. Its potential viability as a biosorbent was demonstrated by the high recovery from synthetic solutions of greater than 99% for gold (2-10 mgIL), and greater than 89% for platinum (20 mgIL).
- Full Text:
- Date Issued: 2002
Broken vessels : the im-possibility of the art of remembrance and re-collection in the work of Anselm Kiefer, Christian Boltanski, William Kentridge and Santu Mofokeng
- Authors: Belluigi, Dina Zoe
- Date: 2002
- Subjects: History in art Kiefer, Anselm, 1945- Boltanski, Christian, 1944- Kentridge, William, 1955- Mofokeng, Santu, 1956-
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2395 , http://hdl.handle.net/10962/d1002191
- Description: This thesis is structured around investigating the philosophical and aesthetic problematics, politics, and possibilities of representing the past for the purposes of demythifying the present as well as commemorating the losses of history, as explored in the artworks of Anselm Kiefer, Christian Boltanski, William Kentridge and Santu Mofokeng. The first chapter begins with Theodor Adorno’s philosophical understanding of myth and history: how he is influenced by and then develops Karl Marx’s critique of society, Sigmund Freud’s critique of reason and its subject, and particularly Walter Benjamin’s ideas of history as catastrophe, the role of the historian and his messianic materialism. The second section looks at Theodor Adorno’s dialectic of art and society: immanent criticism in aesthetic practice, mimesis, and the shift in conceptions of allegory from Walter Benjamin’s understanding to that of Jacques Derrida. The last section of the chapter looks at Jacques Derrida’s poststructuralist theories against boundary-fixing, within that the ethical relation to the ‘other’ and the theorist/artist as psychic exile. The second chapter deals with the politics of remembrance and representation — beginning with Theodor Adorno’s historic interpretation of the Mosaic law against the making of images and Jean-Francois Lyotard on the im-possibility of representing the unrepresentable. The chapter is divided in two parts between the post-Holocaust European artists Anselm Kiefer and Christian Boltanski, and the post-apartheid South African artists William Kentridge and Santu Mofokeng. It explores, within these artists’ specific contexts, their formal and philosophical approaches to myth and history, and the problematics of image-making, representing the unrepresentable, and commemorating the immemorial. The thesis concludes by considering different conceptions of melancholia as they relate to these artists: the Freudian psychoanalytic approach, Benjamin’s notions of the artist-genius, and Julia Kristeva’s Lacanian reading of the humanist melancholic, concluding with the mythic-historical Kaballist notion of melancholia as the historical burden or responsibility to commemorate loss.
- Full Text:
- Date Issued: 2002
- Authors: Belluigi, Dina Zoe
- Date: 2002
- Subjects: History in art Kiefer, Anselm, 1945- Boltanski, Christian, 1944- Kentridge, William, 1955- Mofokeng, Santu, 1956-
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2395 , http://hdl.handle.net/10962/d1002191
- Description: This thesis is structured around investigating the philosophical and aesthetic problematics, politics, and possibilities of representing the past for the purposes of demythifying the present as well as commemorating the losses of history, as explored in the artworks of Anselm Kiefer, Christian Boltanski, William Kentridge and Santu Mofokeng. The first chapter begins with Theodor Adorno’s philosophical understanding of myth and history: how he is influenced by and then develops Karl Marx’s critique of society, Sigmund Freud’s critique of reason and its subject, and particularly Walter Benjamin’s ideas of history as catastrophe, the role of the historian and his messianic materialism. The second section looks at Theodor Adorno’s dialectic of art and society: immanent criticism in aesthetic practice, mimesis, and the shift in conceptions of allegory from Walter Benjamin’s understanding to that of Jacques Derrida. The last section of the chapter looks at Jacques Derrida’s poststructuralist theories against boundary-fixing, within that the ethical relation to the ‘other’ and the theorist/artist as psychic exile. The second chapter deals with the politics of remembrance and representation — beginning with Theodor Adorno’s historic interpretation of the Mosaic law against the making of images and Jean-Francois Lyotard on the im-possibility of representing the unrepresentable. The chapter is divided in two parts between the post-Holocaust European artists Anselm Kiefer and Christian Boltanski, and the post-apartheid South African artists William Kentridge and Santu Mofokeng. It explores, within these artists’ specific contexts, their formal and philosophical approaches to myth and history, and the problematics of image-making, representing the unrepresentable, and commemorating the immemorial. The thesis concludes by considering different conceptions of melancholia as they relate to these artists: the Freudian psychoanalytic approach, Benjamin’s notions of the artist-genius, and Julia Kristeva’s Lacanian reading of the humanist melancholic, concluding with the mythic-historical Kaballist notion of melancholia as the historical burden or responsibility to commemorate loss.
- Full Text:
- Date Issued: 2002
The biotransformation of phenolic pollutants using polyphenol oxidase
- Authors: Boshoff, Aileen
- Date: 2002
- Subjects: Polyphenol oxidase Sewage -- Purification
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3976 , http://hdl.handle.net/10962/d1004035
- Description: The potential of using mushroom polyphenol oxidase (EC 1.14.18.1) as a biocatalyst for the biotransformation of phenols to produce catechols in an aqueous medium was investigated. Polyphenol oxidase is characterised by two distinct reactions i.e., the ortho-hydroxylation of phenols to catechols (cresolase activity) and the subsequent oxidation of catechols to orthoquinones (catecholase activity). In order to facilitate the development of a process to produce catechols, the accumulation of catechol as a true intermediate product released in the reaction system needed to be investigated, as its release had been disputed due to the oxidation of catechols to o-quinones. Using LC-MS, catechol products were successfully identified as true intermediate products formed during biocatalytic reactions in water.
- Full Text:
- Date Issued: 2002
- Authors: Boshoff, Aileen
- Date: 2002
- Subjects: Polyphenol oxidase Sewage -- Purification
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3976 , http://hdl.handle.net/10962/d1004035
- Description: The potential of using mushroom polyphenol oxidase (EC 1.14.18.1) as a biocatalyst for the biotransformation of phenols to produce catechols in an aqueous medium was investigated. Polyphenol oxidase is characterised by two distinct reactions i.e., the ortho-hydroxylation of phenols to catechols (cresolase activity) and the subsequent oxidation of catechols to orthoquinones (catecholase activity). In order to facilitate the development of a process to produce catechols, the accumulation of catechol as a true intermediate product released in the reaction system needed to be investigated, as its release had been disputed due to the oxidation of catechols to o-quinones. Using LC-MS, catechol products were successfully identified as true intermediate products formed during biocatalytic reactions in water.
- Full Text:
- Date Issued: 2002
The relationship between the leadership, internal quality, and customer satisfaction levels of dealerships in a South African motor vehicle organisation
- Authors: Botha, Jennifer
- Date: 2002
- Subjects: Consumer satisfaction , Automobile dealers -- South Africa , Industrial productivity , Customer services
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1185 , http://hdl.handle.net/10962/d1002802 , Consumer satisfaction , Automobile dealers -- South Africa , Industrial productivity , Customer services
- Description: This research investigates the relationship between the leadership, internal quality, and customer satisfaction levels in the dealerships of a South African motor vehicle organisation. The Service Profit Chain provides the background theory to this relationship, by suggesting that various factors within the service delivery system of an organisation affect the level of customer satisfaction. From the Service Profit Chain, it is established that two of the prevalent factors affecting customer satisfaction, are leadership and internal quality. The Full Range Leadership Development Theory provides the backdrop for analysing the leadership style of each dealership by using the Multifactor Leadership Questionnaire. The Competence Process forms the theoretical construct against which the internal quality of these dealerships is assessed using the Organisation Competence Analysis Questionnaire. Information was gathered, using these two instruments, from a sample of 85 motor vehicle dealerships within South Africa. The customer satisfaction levels at each of these dealerships, is measured by the motor vehicle organisation’s own instrument, known as the Customer Satisfaction Index. Data obtained from each instrument, for the respective dealerships, was then statistically analysed. However, due to the low reliability of the instruments used in this research, the results of this study indicate that there is no relationship between the leadership, internal quality, and customer satisfaction levels within a South African motor vehicle organisation. Therefore we can conclude that the null hypotheses can not be rejected.
- Full Text:
- Date Issued: 2002
- Authors: Botha, Jennifer
- Date: 2002
- Subjects: Consumer satisfaction , Automobile dealers -- South Africa , Industrial productivity , Customer services
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1185 , http://hdl.handle.net/10962/d1002802 , Consumer satisfaction , Automobile dealers -- South Africa , Industrial productivity , Customer services
- Description: This research investigates the relationship between the leadership, internal quality, and customer satisfaction levels in the dealerships of a South African motor vehicle organisation. The Service Profit Chain provides the background theory to this relationship, by suggesting that various factors within the service delivery system of an organisation affect the level of customer satisfaction. From the Service Profit Chain, it is established that two of the prevalent factors affecting customer satisfaction, are leadership and internal quality. The Full Range Leadership Development Theory provides the backdrop for analysing the leadership style of each dealership by using the Multifactor Leadership Questionnaire. The Competence Process forms the theoretical construct against which the internal quality of these dealerships is assessed using the Organisation Competence Analysis Questionnaire. Information was gathered, using these two instruments, from a sample of 85 motor vehicle dealerships within South Africa. The customer satisfaction levels at each of these dealerships, is measured by the motor vehicle organisation’s own instrument, known as the Customer Satisfaction Index. Data obtained from each instrument, for the respective dealerships, was then statistically analysed. However, due to the low reliability of the instruments used in this research, the results of this study indicate that there is no relationship between the leadership, internal quality, and customer satisfaction levels within a South African motor vehicle organisation. Therefore we can conclude that the null hypotheses can not be rejected.
- Full Text:
- Date Issued: 2002
The biology and molecular ecology of floating sulphur biofilms
- Authors: Bowker, Michelle Louise
- Date: 2002
- Subjects: Biofilms , Microbial ecology , Sulfur
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4056 , http://hdl.handle.net/10962/d1004117 , Biofilms , Microbial ecology , Sulfur
- Description: Floating sulphur biofilms have been observed to occur on sulphate-containing natural systems and waste stabilization ponds. It has been postulated that these biofilms form on the surface of the water because sulphate reducing bacteria present in the bottom layers of the water body reduce sulphate to sulphide which then diffuses upwards and is oxidized under the correct redox conditions to sulphur by sulphide oxidizing bacteria. Very little information exists on these complex floating systems and in order to study them further, model systems were designed. The Baffle Reactor was successfully used to cultivate floating sulphur biofilms. Conditions within the reactor could be closely scrutinized in the laboratory and it was found that sulphate levels decreased, sulphide levels increased and that sulphur was produced over a period of 2 weeks. The success of this system led to it being scaled-up and currently a method to harvest sulphur from the biofilm is under development. It is thought that biofilms are highly complex, heterogeneous structures with different bacteria distributed in different layers. Preliminary work suggested that bacteria were differentially distributed along nutrient and oxygen gradients within the biofilm. Biofilms are very thin structures and therefore difficult to study and Gradient systems were developed in an attempt to spatially separate the biofilm species into functional layers. Gradient Tubes were designed; these provided a gradient of high-sulphide, low oxygen conditions to high-oxygen, low-sulphide conditions. Bacteria were observed to grow in different layers of these systems. The Gradient Tubes could be sectioned and the chemical characteristics of each section as well as the species present could be determined. Silicon Tubular Bioreactors were also developed and these were very efficient at producing large amounts of sulphur under strictly controlled redox conditions. Microscopy and molecular methods including the amplification of a section of Ribosomal Ribonucleic acid by Polymerase Chain Reaction were used in an attempt to characterize the populations present in these biofilm systems. Denaturing Gradient Gel Electrophoresis was used to create band profiles of the populations; individual bands were excised from the gels and sequenced. Identified species included Ectothiorhodospira sp., Dethiosulfovibrio russensis, Pseudomonas geniculata, Thiobacillus baregensis and Halothiobacillus kellyi.
- Full Text:
- Date Issued: 2002
- Authors: Bowker, Michelle Louise
- Date: 2002
- Subjects: Biofilms , Microbial ecology , Sulfur
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4056 , http://hdl.handle.net/10962/d1004117 , Biofilms , Microbial ecology , Sulfur
- Description: Floating sulphur biofilms have been observed to occur on sulphate-containing natural systems and waste stabilization ponds. It has been postulated that these biofilms form on the surface of the water because sulphate reducing bacteria present in the bottom layers of the water body reduce sulphate to sulphide which then diffuses upwards and is oxidized under the correct redox conditions to sulphur by sulphide oxidizing bacteria. Very little information exists on these complex floating systems and in order to study them further, model systems were designed. The Baffle Reactor was successfully used to cultivate floating sulphur biofilms. Conditions within the reactor could be closely scrutinized in the laboratory and it was found that sulphate levels decreased, sulphide levels increased and that sulphur was produced over a period of 2 weeks. The success of this system led to it being scaled-up and currently a method to harvest sulphur from the biofilm is under development. It is thought that biofilms are highly complex, heterogeneous structures with different bacteria distributed in different layers. Preliminary work suggested that bacteria were differentially distributed along nutrient and oxygen gradients within the biofilm. Biofilms are very thin structures and therefore difficult to study and Gradient systems were developed in an attempt to spatially separate the biofilm species into functional layers. Gradient Tubes were designed; these provided a gradient of high-sulphide, low oxygen conditions to high-oxygen, low-sulphide conditions. Bacteria were observed to grow in different layers of these systems. The Gradient Tubes could be sectioned and the chemical characteristics of each section as well as the species present could be determined. Silicon Tubular Bioreactors were also developed and these were very efficient at producing large amounts of sulphur under strictly controlled redox conditions. Microscopy and molecular methods including the amplification of a section of Ribosomal Ribonucleic acid by Polymerase Chain Reaction were used in an attempt to characterize the populations present in these biofilm systems. Denaturing Gradient Gel Electrophoresis was used to create band profiles of the populations; individual bands were excised from the gels and sequenced. Identified species included Ectothiorhodospira sp., Dethiosulfovibrio russensis, Pseudomonas geniculata, Thiobacillus baregensis and Halothiobacillus kellyi.
- Full Text:
- Date Issued: 2002
A phenomenological investigation of Windhoek Senior Secondary school principals' perceptions and experiences of their leadership roles
- Authors: Boys, Ben
- Date: 2002
- Subjects: School principals -- Namibia Educational leadership -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1700 , http://hdl.handle.net/10962/d1003583
- Description: Namibia, having been a former colony of South Africa, was equally subjected to apartheid laws and practices. Independence, achieved in March 1990, signaled the dawn of a new era of access, equity, quality and democracy in the Namibian education sector. A unified system of educational administration, management, and control was established. The whole educational corps, especially the principals of all our schools, is expected to implement this new system as agents of change. In terms of the vision for a new Namibia, therefore, school principals are seen as occupying positions of central importance. This notion resonates strongly with recent and contemporary leadership thinking. However, a number of concerns prevalent in schools - particularly, increasing student underperformance, worsening disciplinary problems, increasing teenage pregnancy and HIV/AIDS pandemic, teacher qualification, decreasing teacher motivation, lack of training including induction for principals, inadequate support from the top (lack of a support system) and insufficient parental involvement in school matters – make the task of running schools extremely challenging and increasingly complex. How do principals experience these challenges and deal with the complex situations? How do they perceive their role, particularly in light of national aspirations and leadership theory? These are questions I think need to be explored. My research goal was to gain an understanding of Windhoek senior secondary school principals’ perceptions and experiences of their leadership role. My focus was on three purposively selected Windhoek senior secondary school principals representative of both the Namibian ethno-cultural diversity and gender. Data was collected through interviews. I found that the situations in which the principals found themselves during the pre- and post independent periods mainly determined their leadership style and behaviour, however, that did not deter their vision for the transformation of the society, as the ultimate objective and essence of their leadership. The appropriate practicing of their leadership role was being hampered by lack of induction and training, lack of a support system and insufficient parental involvement.
- Full Text:
- Date Issued: 2002
- Authors: Boys, Ben
- Date: 2002
- Subjects: School principals -- Namibia Educational leadership -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1700 , http://hdl.handle.net/10962/d1003583
- Description: Namibia, having been a former colony of South Africa, was equally subjected to apartheid laws and practices. Independence, achieved in March 1990, signaled the dawn of a new era of access, equity, quality and democracy in the Namibian education sector. A unified system of educational administration, management, and control was established. The whole educational corps, especially the principals of all our schools, is expected to implement this new system as agents of change. In terms of the vision for a new Namibia, therefore, school principals are seen as occupying positions of central importance. This notion resonates strongly with recent and contemporary leadership thinking. However, a number of concerns prevalent in schools - particularly, increasing student underperformance, worsening disciplinary problems, increasing teenage pregnancy and HIV/AIDS pandemic, teacher qualification, decreasing teacher motivation, lack of training including induction for principals, inadequate support from the top (lack of a support system) and insufficient parental involvement in school matters – make the task of running schools extremely challenging and increasingly complex. How do principals experience these challenges and deal with the complex situations? How do they perceive their role, particularly in light of national aspirations and leadership theory? These are questions I think need to be explored. My research goal was to gain an understanding of Windhoek senior secondary school principals’ perceptions and experiences of their leadership role. My focus was on three purposively selected Windhoek senior secondary school principals representative of both the Namibian ethno-cultural diversity and gender. Data was collected through interviews. I found that the situations in which the principals found themselves during the pre- and post independent periods mainly determined their leadership style and behaviour, however, that did not deter their vision for the transformation of the society, as the ultimate objective and essence of their leadership. The appropriate practicing of their leadership role was being hampered by lack of induction and training, lack of a support system and insufficient parental involvement.
- Full Text:
- Date Issued: 2002
The effect of energy and protein nutritional levels on production of breeding ostriches
- Authors: Brand, Zanell
- Date: 2002
- Subjects: Ostriches -- Nutrition , Ostriches -- Breeding--South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5805 , http://hdl.handle.net/10962/d1006312 , Ostriches -- Nutrition , Ostriches -- Breeding--South Africa
- Description: Adequate and appropriate nutrition is essential for the production of high quality commercially farmed animal species. Although South Africa has had a well-established ostrich industry for over a century, little information on ostrich nutrition, in particular the specific nutritional requirements at different stages of production, is available. The industry has consequently relied heavily on data derived from poultry and pigs, but this has often proved to be unsatisfactory for ostriches and has resulted in serious nutritional-related problems. Recent studies on the metabolisable energy of specific components of diet formulations and balanced diets have indicated that ostriches have enhanced digestibility compared with poultry and pigs. At the same time, in the present economic climate, it is necessary to find cost-effective diets for breeding birds without compromising egg and chick production. This study primarily assessed the effect of different dietary protein and energy levels on production parameters and body condition of breeding female and male ostriches. The energy content of the diet appears to be the main constraint to egg production and breeders on low energy diets laid fewer eggs and lost more body condition compared with breeders fed higher energy diets. A diet with 8.5 MJ/kg DM and 10% protein with well balanced amino acids appears to be sufficient for female breeders without compromising production and a diet with 7.5 MJ/kg DM and 10% protein appears suitable for breeding male ostriches. Different dietary energy and protein levels similarly had little or no effect on egg quality and composition. This study also assessed the carry-over effect of the nutritional regime in one year on the production in the following breeding season. Females fed diets as low as 7.5 MJ/kg ME in the previous breeding season produced significantly fewer eggs in the next breeding season, which resulted in lower chick production. Energy had no effect on the percentage infertile eggs or on the initial egg weight. Different levels of dietary protein had no effect on egg production, egg weight, fertility, hatchability and initial chick weight.
- Full Text:
- Date Issued: 2002
- Authors: Brand, Zanell
- Date: 2002
- Subjects: Ostriches -- Nutrition , Ostriches -- Breeding--South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5805 , http://hdl.handle.net/10962/d1006312 , Ostriches -- Nutrition , Ostriches -- Breeding--South Africa
- Description: Adequate and appropriate nutrition is essential for the production of high quality commercially farmed animal species. Although South Africa has had a well-established ostrich industry for over a century, little information on ostrich nutrition, in particular the specific nutritional requirements at different stages of production, is available. The industry has consequently relied heavily on data derived from poultry and pigs, but this has often proved to be unsatisfactory for ostriches and has resulted in serious nutritional-related problems. Recent studies on the metabolisable energy of specific components of diet formulations and balanced diets have indicated that ostriches have enhanced digestibility compared with poultry and pigs. At the same time, in the present economic climate, it is necessary to find cost-effective diets for breeding birds without compromising egg and chick production. This study primarily assessed the effect of different dietary protein and energy levels on production parameters and body condition of breeding female and male ostriches. The energy content of the diet appears to be the main constraint to egg production and breeders on low energy diets laid fewer eggs and lost more body condition compared with breeders fed higher energy diets. A diet with 8.5 MJ/kg DM and 10% protein with well balanced amino acids appears to be sufficient for female breeders without compromising production and a diet with 7.5 MJ/kg DM and 10% protein appears suitable for breeding male ostriches. Different dietary energy and protein levels similarly had little or no effect on egg quality and composition. This study also assessed the carry-over effect of the nutritional regime in one year on the production in the following breeding season. Females fed diets as low as 7.5 MJ/kg ME in the previous breeding season produced significantly fewer eggs in the next breeding season, which resulted in lower chick production. Energy had no effect on the percentage infertile eggs or on the initial egg weight. Different levels of dietary protein had no effect on egg production, egg weight, fertility, hatchability and initial chick weight.
- Full Text:
- Date Issued: 2002
The relationship between three anxiety related clusters in projective drawings and anxiety and ego-strength scales of the Minnesota multiphasic personality inventory-2
- Authors: Brink, André
- Date: 2002
- Subjects: Projective techniques , Personality assessment , Personality tests , Anxiety , Minnesota Multiphasic Personality Inventory
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2942 , http://hdl.handle.net/10962/d1002451 , Projective techniques , Personality assessment , Personality tests , Anxiety , Minnesota Multiphasic Personality Inventory
- Description: Based on the shortcomings of past research, the need for understanding and investigation of the general relationship between self-report measures and human figure drawings required understanding and investigation (Riethmiller & Handler, 1997b; Waehler, 1997) while utilising a quantitative, configural scoring approach. Riethmiller and Handler (1997a; 1997b) hypothesised that subjects have one of two typical approach styles to anxiety/stress that influences their execution of the Human Figure Drawing (HFD) Test: “Avoidance” or “Coping” as measured by composite scoring index clusters. They argue that these two approach styles had to be taken into account when investigating anxiety on the HFD Test. According to Handler and Reyher (1965) those who experience more intense anxiety typically rely on an “Avoidant” approach, while those with lower anxiety typically rely on a “Coping” approach. The “Coping” response is hypothesised to suggest good ego-strength, and the “Avoidant” response poor ego-strength. Handler and Reyher (1964; 1965; 1966) also argued that there are two sources of anxiety on projective drawings: internal and external sources of anxiety. They hypothesised that the “External” anxiety cluster (measured by utilising the car drawing) and self-report measures both assess ‘external’ anxiety. Using Handler’s (1967) HFD index scoring manual, this research therefore inve stigated the level of correlation of the two MMPI-2 anxiety scale scores with (a) the hypothesised Stress Approach HFD cluster scores, as well as with (b) the “External” anxiety cluster score, while the hypothesised Stress Approach HFD cluster scores were compared with the (c) MMPI-2 ego strength scale score. The results of the investigated relationships yielded non-significant correlations overall. The differences in nature of the two measurement instruments, and the potential weaknesses of this study, as two likely explanations for these correlations, are discussed. In the consideration of the differences of the two measurement instruments, the weaknesses of SR measures and criterion-related validity are discussed while self- attributed and implicit motives are contrasted with each other. Potential extraneous variables and possible truncated range are discussed as potential weaknesses of this study.
- Full Text:
- Date Issued: 2002
- Authors: Brink, André
- Date: 2002
- Subjects: Projective techniques , Personality assessment , Personality tests , Anxiety , Minnesota Multiphasic Personality Inventory
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2942 , http://hdl.handle.net/10962/d1002451 , Projective techniques , Personality assessment , Personality tests , Anxiety , Minnesota Multiphasic Personality Inventory
- Description: Based on the shortcomings of past research, the need for understanding and investigation of the general relationship between self-report measures and human figure drawings required understanding and investigation (Riethmiller & Handler, 1997b; Waehler, 1997) while utilising a quantitative, configural scoring approach. Riethmiller and Handler (1997a; 1997b) hypothesised that subjects have one of two typical approach styles to anxiety/stress that influences their execution of the Human Figure Drawing (HFD) Test: “Avoidance” or “Coping” as measured by composite scoring index clusters. They argue that these two approach styles had to be taken into account when investigating anxiety on the HFD Test. According to Handler and Reyher (1965) those who experience more intense anxiety typically rely on an “Avoidant” approach, while those with lower anxiety typically rely on a “Coping” approach. The “Coping” response is hypothesised to suggest good ego-strength, and the “Avoidant” response poor ego-strength. Handler and Reyher (1964; 1965; 1966) also argued that there are two sources of anxiety on projective drawings: internal and external sources of anxiety. They hypothesised that the “External” anxiety cluster (measured by utilising the car drawing) and self-report measures both assess ‘external’ anxiety. Using Handler’s (1967) HFD index scoring manual, this research therefore inve stigated the level of correlation of the two MMPI-2 anxiety scale scores with (a) the hypothesised Stress Approach HFD cluster scores, as well as with (b) the “External” anxiety cluster score, while the hypothesised Stress Approach HFD cluster scores were compared with the (c) MMPI-2 ego strength scale score. The results of the investigated relationships yielded non-significant correlations overall. The differences in nature of the two measurement instruments, and the potential weaknesses of this study, as two likely explanations for these correlations, are discussed. In the consideration of the differences of the two measurement instruments, the weaknesses of SR measures and criterion-related validity are discussed while self- attributed and implicit motives are contrasted with each other. Potential extraneous variables and possible truncated range are discussed as potential weaknesses of this study.
- Full Text:
- Date Issued: 2002
A case study of the language policy in practice in the foundation phase of schooling
- Authors: Brookes, Margaret Ann
- Date: 2002
- Subjects: Language policy -- South Africa English language -- Study and teaching (Elementary) -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1442 , http://hdl.handle.net/10962/d1003323
- Description: This interpretative case study takes place in the foundation phase of a previously parallel medium school in the Eastern Cape. Learners from all three major language groups of the province (English, Xhosa and Afrikaans) are enrolled at the school. The study examines the language attitudes of teachers, parents and young learners and records their language practices in the classroom, the wider school environment and at home. Research carried out through this case study found that all stakeholders perceive English as the language of access to improved education and lifestyle. All young learners displayed a positive attitude to multilingualism and were keen to be able to speak all three provincial languages. The attitudes of their parents and teachers however differed from the learners and each other. The teachers and the English speaking parents were primarily concerned with the maintenance of the standards of English. The Afrikaans and Xhosa speaking parents were committed to their children developing proficient English language skills even if this meant supporting the development of their primary language and culture at home. Furthermore it was discovered that little attention had been paid to developing a school language policy in accordance with the new Language in Education Policy of July 1997. This policy promotes an additive approach to bilingualism and seeks to ensure that meaningful access to learning is provided for all children. By suggesting steps that could be taken by this school to develop their own language policy, the study highlights the necessity of recognising and remedying the gaps between policy and practice in the issue of language rights, identity and education in general.
- Full Text:
- Date Issued: 2002
- Authors: Brookes, Margaret Ann
- Date: 2002
- Subjects: Language policy -- South Africa English language -- Study and teaching (Elementary) -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1442 , http://hdl.handle.net/10962/d1003323
- Description: This interpretative case study takes place in the foundation phase of a previously parallel medium school in the Eastern Cape. Learners from all three major language groups of the province (English, Xhosa and Afrikaans) are enrolled at the school. The study examines the language attitudes of teachers, parents and young learners and records their language practices in the classroom, the wider school environment and at home. Research carried out through this case study found that all stakeholders perceive English as the language of access to improved education and lifestyle. All young learners displayed a positive attitude to multilingualism and were keen to be able to speak all three provincial languages. The attitudes of their parents and teachers however differed from the learners and each other. The teachers and the English speaking parents were primarily concerned with the maintenance of the standards of English. The Afrikaans and Xhosa speaking parents were committed to their children developing proficient English language skills even if this meant supporting the development of their primary language and culture at home. Furthermore it was discovered that little attention had been paid to developing a school language policy in accordance with the new Language in Education Policy of July 1997. This policy promotes an additive approach to bilingualism and seeks to ensure that meaningful access to learning is provided for all children. By suggesting steps that could be taken by this school to develop their own language policy, the study highlights the necessity of recognising and remedying the gaps between policy and practice in the issue of language rights, identity and education in general.
- Full Text:
- Date Issued: 2002
A historical study of John Graham Lake and South African/United States pentecostalism
- Authors: Burpeau, Kemp Pendleton
- Date: 2002
- Subjects: Lake, John G , Pentecostalism -- South Africa , Pentecostalism -- United States , Pentecostals , Christianity and politics -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2587 , http://hdl.handle.net/10962/d1006484 , Lake, John G , Pentecostalism -- South Africa , Pentecostalism -- United States , Pentecostals , Christianity and politics -- South Africa
- Description: American minister John Graham Lake (1870-1935) was a pivotal participant in an era of profound religious and political transition. Surprisingly, Lake's often provocative life had previously been largely neglected as a field of academic inquiry. In the U.S. Lake associated with key Holiness, Wesleyan and Apostolic Faith charismatics like John Alexander Dowie of the Zion City, Illinois Utopia, Charles Parham of the Topeka Revival and William Seymour of the Azusa Street Revival. Lake served as an important intermediary between Parham's often reactionary, white orientation that was unreceptive to an enthusiastic black liturgy and Seymour's expansive African-American egalitarianism expressed through exuberant spirit manifestations. Lake's South African ministry was shaped by his middle class white business background, Azusa Street message and American perspectives. He brought together the faith healing movement inspired by Dutch Reformed minister Andrew Murray, P. Ie Roux's black and white Zion charismatic adherents affiliated with Dowie and the new U.S. Pentecostalism of Parham and Seymour. Lake's African-American influenced Pentecostalism was compatible with indigenous African worship. His emphasis on the spiritual needs of the disempowered found a receptive audience in talented black evangelists Elias Letwaba and Edward Lion. Even though acquainted with Mohandas Gandhi, Lake did not undertake a South African social gospel-type civil protest against societal injustice. In fact, Lake's participation with Afrikaner politicians like Louis Botha in fashioning a segregationist land use law was most troubling. Lake was ambivalent about racial integration. His belief in an egalitarian status for all Christians, his Populist/Progressive ethics and his enthusiastic promotion of women's rights were complicated by his advocacy, or at least tolerance, of some disparate racial treatment in his Apostolic Faith Mission and South African society at large. Lake's paternalism and notion of Westem cultural superiority conflicted with his love of all persons. Lake's otherworldly prioritization of individual spiritualism over a socioeconomic agenda usually stymied activism. His uncharacteristic use of nonviolent protest to protect faith healing formed a remarkable contrast with his reluctance to actively campaign against unequal racial treatment in Africa and America. Historiographical perspectives on Lake range from the saintly pioneer charismatic missionary to the Elmer Gantry type charlatan acting only for personal benefit. Lake was a unique personality with his flamboyant rhetoric, strong convictions and feelings of personal worth. His distinctive Jesus as healing and suffering God theology evidenced both consistency with precedent as well as creative anticipation. Shortcomings resulting from his preference to address social concerns on an individual spiritual rather than societal level, his liberties with truth and his bad business judgments resulting in litigation. Nevertheless, Lake's life demonstrated that a gifted but imperfect instrument could accomplish a meaningful ministry. , Adobe Acrobat Pro 9.5.4 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2002
- Authors: Burpeau, Kemp Pendleton
- Date: 2002
- Subjects: Lake, John G , Pentecostalism -- South Africa , Pentecostalism -- United States , Pentecostals , Christianity and politics -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2587 , http://hdl.handle.net/10962/d1006484 , Lake, John G , Pentecostalism -- South Africa , Pentecostalism -- United States , Pentecostals , Christianity and politics -- South Africa
- Description: American minister John Graham Lake (1870-1935) was a pivotal participant in an era of profound religious and political transition. Surprisingly, Lake's often provocative life had previously been largely neglected as a field of academic inquiry. In the U.S. Lake associated with key Holiness, Wesleyan and Apostolic Faith charismatics like John Alexander Dowie of the Zion City, Illinois Utopia, Charles Parham of the Topeka Revival and William Seymour of the Azusa Street Revival. Lake served as an important intermediary between Parham's often reactionary, white orientation that was unreceptive to an enthusiastic black liturgy and Seymour's expansive African-American egalitarianism expressed through exuberant spirit manifestations. Lake's South African ministry was shaped by his middle class white business background, Azusa Street message and American perspectives. He brought together the faith healing movement inspired by Dutch Reformed minister Andrew Murray, P. Ie Roux's black and white Zion charismatic adherents affiliated with Dowie and the new U.S. Pentecostalism of Parham and Seymour. Lake's African-American influenced Pentecostalism was compatible with indigenous African worship. His emphasis on the spiritual needs of the disempowered found a receptive audience in talented black evangelists Elias Letwaba and Edward Lion. Even though acquainted with Mohandas Gandhi, Lake did not undertake a South African social gospel-type civil protest against societal injustice. In fact, Lake's participation with Afrikaner politicians like Louis Botha in fashioning a segregationist land use law was most troubling. Lake was ambivalent about racial integration. His belief in an egalitarian status for all Christians, his Populist/Progressive ethics and his enthusiastic promotion of women's rights were complicated by his advocacy, or at least tolerance, of some disparate racial treatment in his Apostolic Faith Mission and South African society at large. Lake's paternalism and notion of Westem cultural superiority conflicted with his love of all persons. Lake's otherworldly prioritization of individual spiritualism over a socioeconomic agenda usually stymied activism. His uncharacteristic use of nonviolent protest to protect faith healing formed a remarkable contrast with his reluctance to actively campaign against unequal racial treatment in Africa and America. Historiographical perspectives on Lake range from the saintly pioneer charismatic missionary to the Elmer Gantry type charlatan acting only for personal benefit. Lake was a unique personality with his flamboyant rhetoric, strong convictions and feelings of personal worth. His distinctive Jesus as healing and suffering God theology evidenced both consistency with precedent as well as creative anticipation. Shortcomings resulting from his preference to address social concerns on an individual spiritual rather than societal level, his liberties with truth and his bad business judgments resulting in litigation. Nevertheless, Lake's life demonstrated that a gifted but imperfect instrument could accomplish a meaningful ministry. , Adobe Acrobat Pro 9.5.4 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2002
The molecular microbial ecology of sulfate reduction in the Rhodes BioSURE process
- Authors: Chauke, Chesa Gift
- Date: 2002
- Subjects: Water -- Purification -- Biological treatment , Acid mine drainage , Water -- Microbiology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4082 , http://hdl.handle.net/10962/d1007475 , Water -- Purification -- Biological treatment , Acid mine drainage , Water -- Microbiology
- Description: The research reported here investigated the use of a Baffle Reactor in order to study aspects of the biological sulfur cycle, where a floating sulfur biofilm formation occurs and where complex organic compounds provide electron donor sources. The development of a laboratory-scale Baffle Reactor model system satisfied the requirements for sulfate reducing bacterial biomass growth and sulfur biofilm formation. Since relatively little is known about the microbial ecology of floating sulfur biofilm systems, this study was undertaken to describe the sulfate reducing sludge population of the system together with its performance. A combination of culture- and molecular-based techniques were applied in this study in order to investigate the microbial ecology of the sulfate-reducing bacteria component of the system. These techniques enabled the identification and the analysis of the distribution of different sulfate reducing bacterial strains found within the sludge bioreactors. Strains isolated from the sludge were characterised based on culture appearance, gram staining and scanning electron microscopy morphology. Molecular methods based on the PCR-amplified 16S rRNA including denaturing gradient gel electrophoresis were employed in order to characterise sulfate-reducing bacteria within the reactors. Three novel Gram negative sulfate-reducing bacteria strains were isolated from the sludge population. Strains isolated were tentatively named Desulfomonas rhodensis, Desulfomonas makanaiensis, and Clostridium sulforhodensis. Results obtained from the Baffle Reactor showed that three dominant species were isolated from the DNA extracted from the whole bacterial population by peR. Three of these were similar to those mentioned above. The presence of these three novel unidentified species suggest that there are a range of other novel organisms involved in sulfate reduction processes.
- Full Text:
- Date Issued: 2002
- Authors: Chauke, Chesa Gift
- Date: 2002
- Subjects: Water -- Purification -- Biological treatment , Acid mine drainage , Water -- Microbiology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4082 , http://hdl.handle.net/10962/d1007475 , Water -- Purification -- Biological treatment , Acid mine drainage , Water -- Microbiology
- Description: The research reported here investigated the use of a Baffle Reactor in order to study aspects of the biological sulfur cycle, where a floating sulfur biofilm formation occurs and where complex organic compounds provide electron donor sources. The development of a laboratory-scale Baffle Reactor model system satisfied the requirements for sulfate reducing bacterial biomass growth and sulfur biofilm formation. Since relatively little is known about the microbial ecology of floating sulfur biofilm systems, this study was undertaken to describe the sulfate reducing sludge population of the system together with its performance. A combination of culture- and molecular-based techniques were applied in this study in order to investigate the microbial ecology of the sulfate-reducing bacteria component of the system. These techniques enabled the identification and the analysis of the distribution of different sulfate reducing bacterial strains found within the sludge bioreactors. Strains isolated from the sludge were characterised based on culture appearance, gram staining and scanning electron microscopy morphology. Molecular methods based on the PCR-amplified 16S rRNA including denaturing gradient gel electrophoresis were employed in order to characterise sulfate-reducing bacteria within the reactors. Three novel Gram negative sulfate-reducing bacteria strains were isolated from the sludge population. Strains isolated were tentatively named Desulfomonas rhodensis, Desulfomonas makanaiensis, and Clostridium sulforhodensis. Results obtained from the Baffle Reactor showed that three dominant species were isolated from the DNA extracted from the whole bacterial population by peR. Three of these were similar to those mentioned above. The presence of these three novel unidentified species suggest that there are a range of other novel organisms involved in sulfate reduction processes.
- Full Text:
- Date Issued: 2002
Physiological and perceptual responses of SANDF personnel to varying combinations of marching speed and backpack load
- Authors: Christie, Candice Jo-Anne
- Date: 2002
- Subjects: Marching -- Physiological aspects , Walking -- Physiological aspects
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5128 , http://hdl.handle.net/10962/d1005207 , Marching -- Physiological aspects , Walking -- Physiological aspects
- Description: The objective of the present study was to establish effective combinations of marching speed and backpack load in order to meet specific military requirements. Thirty infantrymen from the South African National Defence Force (SANDF) comprised the sample and experimental procedures were conducted in a laboratory setting using a Cybex Trotter treadmill. Sixteen conditions were set up which included combinations of four speeds (3.5, 4.5, 5.5, and 6.5 km.h⁻¹) and four backpack loads (20, 35, 50, and 65kg). Each subject was required to complete 8 of the sixteen conditions, each consisting of a six-minute treadmill march. Physiological data (heart rate, ventilation and metabolic responses), kinematic gait responses (step-rate and stride length) and perceptions of exertion (“Central” and “Local” RPE) were collected during the third and sixth minutes of the treadmill march and areas of body discomfort were identified post-march. Responses revealed five distinct categories of exertional strain. Three marches constituted “nominal” (below 40% VO₂max) and three “excessive” strain (above 75% VO₂ max). These represent combinations of extreme military demands and are highly unlikely to be utilised by the military. Three “tolerable” levels of required effort were recommended and these 10 combinations were further divided into three sub-categories. The “moderate” stress marches were identified as “ideal” for prolonged marches and had statistically similar responses of working heart rates (range of 118 bt.min⁻¹ to 127 bt.min⁻¹), energy expenditure (26 kJ.min⁻¹ and 27 kJ.min⁻¹) and ratings of perceived exertion (“Central” ratings of 10 and 11). Thus, marching at 5.5 km.h⁻¹with 20kg, 4.5 km.h⁻¹ with 35kg or 3.5 km.h⁻¹ with 50kg all require a similar energy cost. Four “heavy” category marches were identified for possible use when the duration of the march is reduced. During these marches responses were statistically similar with heart rates ranging from 127 bt.min⁻¹ to 137 bt.min⁻¹, energy expenditure from 32 kJ.min⁻¹ to 37 kJ.min⁻¹ and “Central” ratings of perceived exertion were 12 and 13. When short, high intensity marches are necessary, then combinations from the “very heavy” category may be utilised but with caution. During these marches, soldiers were taxed between 65% and 75% of VO2 max. The results of this study clearly demonstrate that the interplay between speed and load needs to be adjusted when determining “ideal” combinations for specific military demands. Essentially, if speed is of the essence then load must be reduced, and if heavy loads need to be transported then speed must be reduced.
- Full Text:
- Date Issued: 2002
- Authors: Christie, Candice Jo-Anne
- Date: 2002
- Subjects: Marching -- Physiological aspects , Walking -- Physiological aspects
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5128 , http://hdl.handle.net/10962/d1005207 , Marching -- Physiological aspects , Walking -- Physiological aspects
- Description: The objective of the present study was to establish effective combinations of marching speed and backpack load in order to meet specific military requirements. Thirty infantrymen from the South African National Defence Force (SANDF) comprised the sample and experimental procedures were conducted in a laboratory setting using a Cybex Trotter treadmill. Sixteen conditions were set up which included combinations of four speeds (3.5, 4.5, 5.5, and 6.5 km.h⁻¹) and four backpack loads (20, 35, 50, and 65kg). Each subject was required to complete 8 of the sixteen conditions, each consisting of a six-minute treadmill march. Physiological data (heart rate, ventilation and metabolic responses), kinematic gait responses (step-rate and stride length) and perceptions of exertion (“Central” and “Local” RPE) were collected during the third and sixth minutes of the treadmill march and areas of body discomfort were identified post-march. Responses revealed five distinct categories of exertional strain. Three marches constituted “nominal” (below 40% VO₂max) and three “excessive” strain (above 75% VO₂ max). These represent combinations of extreme military demands and are highly unlikely to be utilised by the military. Three “tolerable” levels of required effort were recommended and these 10 combinations were further divided into three sub-categories. The “moderate” stress marches were identified as “ideal” for prolonged marches and had statistically similar responses of working heart rates (range of 118 bt.min⁻¹ to 127 bt.min⁻¹), energy expenditure (26 kJ.min⁻¹ and 27 kJ.min⁻¹) and ratings of perceived exertion (“Central” ratings of 10 and 11). Thus, marching at 5.5 km.h⁻¹with 20kg, 4.5 km.h⁻¹ with 35kg or 3.5 km.h⁻¹ with 50kg all require a similar energy cost. Four “heavy” category marches were identified for possible use when the duration of the march is reduced. During these marches responses were statistically similar with heart rates ranging from 127 bt.min⁻¹ to 137 bt.min⁻¹, energy expenditure from 32 kJ.min⁻¹ to 37 kJ.min⁻¹ and “Central” ratings of perceived exertion were 12 and 13. When short, high intensity marches are necessary, then combinations from the “very heavy” category may be utilised but with caution. During these marches, soldiers were taxed between 65% and 75% of VO2 max. The results of this study clearly demonstrate that the interplay between speed and load needs to be adjusted when determining “ideal” combinations for specific military demands. Essentially, if speed is of the essence then load must be reduced, and if heavy loads need to be transported then speed must be reduced.
- Full Text:
- Date Issued: 2002
Towards a broader socio-ecological education : a case study of school based curricular reform
- Authors: Cimma, Gary Martin
- Date: 2002
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:20973 , http://hdl.handle.net/10962/5763
- Description: This work documents and analyses an action research project that the researcher undertook in conjunction with colleagues at an independent Catholic high school in Johannesburg. The main objective was to try to expand the existing curriculum in operation at the time of starting the research to one, which was more socio-ecologically sensitive. One of the key references during the action research was the recently drafted ‘Vision Statement’ document, which detailed the educational ideals of the school. Some of the key findings that emerged as the research proceeded, were that the levels of socio-ecological sensitivity displayed by the learners were influenced by the backgrounds from which they came, and that these background environments were often not comfortable with the changes taking place in the educational and greater South African environments. The Participatory Action Research mode of research which was used proved to be problematic in that only a handful of the educators actually got involved in participating in the project. The failure of many of educators to get involved was, in the opinion of the researcher, due to their lack of understanding how important the development of social and ecological sensitivity are to the necessary change capacity required in present day South African society. The need to be involved in the ongoing development of curriculum as required by Curriculum 2005 as a form of Outcomes Based Education was also problematic as some educators were not familiar with their role in this regard. The limited time-span of the research was also a limiting factor as the development of a socio-ecologically sensitive curriculum required changes in some fundamental attitudes and approaches to education and the environment.
- Full Text:
- Date Issued: 2002
- Authors: Cimma, Gary Martin
- Date: 2002
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:20973 , http://hdl.handle.net/10962/5763
- Description: This work documents and analyses an action research project that the researcher undertook in conjunction with colleagues at an independent Catholic high school in Johannesburg. The main objective was to try to expand the existing curriculum in operation at the time of starting the research to one, which was more socio-ecologically sensitive. One of the key references during the action research was the recently drafted ‘Vision Statement’ document, which detailed the educational ideals of the school. Some of the key findings that emerged as the research proceeded, were that the levels of socio-ecological sensitivity displayed by the learners were influenced by the backgrounds from which they came, and that these background environments were often not comfortable with the changes taking place in the educational and greater South African environments. The Participatory Action Research mode of research which was used proved to be problematic in that only a handful of the educators actually got involved in participating in the project. The failure of many of educators to get involved was, in the opinion of the researcher, due to their lack of understanding how important the development of social and ecological sensitivity are to the necessary change capacity required in present day South African society. The need to be involved in the ongoing development of curriculum as required by Curriculum 2005 as a form of Outcomes Based Education was also problematic as some educators were not familiar with their role in this regard. The limited time-span of the research was also a limiting factor as the development of a socio-ecologically sensitive curriculum required changes in some fundamental attitudes and approaches to education and the environment.
- Full Text:
- Date Issued: 2002
The independent high rate algal pond as a unit operation in tertiary wastewater treatment
- Authors: Clark, Stewart James
- Date: 2002
- Subjects: Algae -- Biotechnology , Sewage -- Purification -- Biological treatment
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4092 , http://hdl.handle.net/10962/d1007805
- Description: The development of the High Rate Algal Pond (HRAP) as an independent tertiary treatment unit operation for phosphate and nitrate removal is reported. A novel Integrated Algal Ponding System (lAPS) design is proposed for nutrient removal from the effluents of both a conventional domestic sewage treatment plant and from an Advanced Integrated Wastewater Ponding System (AIWPS). The viability of an independently operated HRAP has been identified and termed the Independent High Rate Algal Pond (l-HRAP). A 500 m² pilot 1- HRAP was operated in such a way as to facilitate the precipitation of calcium phosphate, known to be controlled by pH (greater than 9.4) and resulting in final phosphate levels of less than 1 mg.L⁻¹ as P0₄-P. The incorporation of the I-HRAP into a denitrification process was also investigated. Continuously fed column reactors, utilising algal biomass as a carbon source, showed that the heterotrophic bacterial community dominant in the anaerobic algal sludge were denitrifying the nitrate in the feed. It was demonstrated that as the cultures were stressed (using increased nitrate concentrations, anaerobiosis and light starvation) total polysaccharide (TPS) concentrations increased, with a notable increase 111 the exopolysaccharide (EPS) fraction. These experiments corroborated the hypothesis that harvested microalgal biomass can be manipulated to produce, and release, exopolymeric substances under stress conditions, and which may serve as carbon source for denitrification. In both batch flask studies and in laboratory-scale reactor systems, harvested microalgal biomass from an HRAP was shown to produce exopolymeric substances under stress conditions. Initial high loading-rates of greater than 20 mg.L⁻¹ NO₃-N resulted in double the amount of exopolysaccharide production than in flasks with initial low loading-rates (less than 5 mg.L⁻¹ NO₃-N). Making use of an upflow anaerobic sludge blanket-type degrading-bed reactor, and an anaerobic, flooded trickle filter (ANTRIC) receiving HRAP effluent, the relationship between denitrification and the changes in polysaccharide content was investigated. This phenomenon has considerable beneficial implications in biological wastewater treatment systems where high nitrate concentration in the final effluent is a potential mitigating factor. Identification of the heterotrophic bacteria active in the denitrification process was attempted. This study presents a first report on the development and operation of the I-HRAP and has been followed by a technical-scale pilot plant evaluation of the process in the tertiary treatment of domestic wastewaters.
- Full Text:
- Date Issued: 2002
- Authors: Clark, Stewart James
- Date: 2002
- Subjects: Algae -- Biotechnology , Sewage -- Purification -- Biological treatment
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4092 , http://hdl.handle.net/10962/d1007805
- Description: The development of the High Rate Algal Pond (HRAP) as an independent tertiary treatment unit operation for phosphate and nitrate removal is reported. A novel Integrated Algal Ponding System (lAPS) design is proposed for nutrient removal from the effluents of both a conventional domestic sewage treatment plant and from an Advanced Integrated Wastewater Ponding System (AIWPS). The viability of an independently operated HRAP has been identified and termed the Independent High Rate Algal Pond (l-HRAP). A 500 m² pilot 1- HRAP was operated in such a way as to facilitate the precipitation of calcium phosphate, known to be controlled by pH (greater than 9.4) and resulting in final phosphate levels of less than 1 mg.L⁻¹ as P0₄-P. The incorporation of the I-HRAP into a denitrification process was also investigated. Continuously fed column reactors, utilising algal biomass as a carbon source, showed that the heterotrophic bacterial community dominant in the anaerobic algal sludge were denitrifying the nitrate in the feed. It was demonstrated that as the cultures were stressed (using increased nitrate concentrations, anaerobiosis and light starvation) total polysaccharide (TPS) concentrations increased, with a notable increase 111 the exopolysaccharide (EPS) fraction. These experiments corroborated the hypothesis that harvested microalgal biomass can be manipulated to produce, and release, exopolymeric substances under stress conditions, and which may serve as carbon source for denitrification. In both batch flask studies and in laboratory-scale reactor systems, harvested microalgal biomass from an HRAP was shown to produce exopolymeric substances under stress conditions. Initial high loading-rates of greater than 20 mg.L⁻¹ NO₃-N resulted in double the amount of exopolysaccharide production than in flasks with initial low loading-rates (less than 5 mg.L⁻¹ NO₃-N). Making use of an upflow anaerobic sludge blanket-type degrading-bed reactor, and an anaerobic, flooded trickle filter (ANTRIC) receiving HRAP effluent, the relationship between denitrification and the changes in polysaccharide content was investigated. This phenomenon has considerable beneficial implications in biological wastewater treatment systems where high nitrate concentration in the final effluent is a potential mitigating factor. Identification of the heterotrophic bacteria active in the denitrification process was attempted. This study presents a first report on the development and operation of the I-HRAP and has been followed by a technical-scale pilot plant evaluation of the process in the tertiary treatment of domestic wastewaters.
- Full Text:
- Date Issued: 2002
A critical investigation into the managerial implications of inclusive education
- Authors: Cloete, Sanet
- Date: 2002
- Subjects: School management and organization -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1477 , http://hdl.handle.net/10962/d1003358
- Description: Special needs education has always provided special challenges to school administrators, policy makers and teachers. The world-wide move towards inclusive education as an alternative to exclusive education or casual mainstreaming has resulted in significant developments in Namibia in the past decade. Global educational reforms have focused on education for all as well as inclusive education and Namibia is signatory to several conventions and declarations in this regard. Research in this field has largely focused on the role of the inclusive teacher, and of course the special needs of the learners. Little or no attention has been paid to possible managerial and organisational challenges which accompany the move to inclusive education. This thesis seeks to critically investigate the managerial implications of inclusive education. The focal point of this research is to gain a clear understanding of the managerial implications in an inclusive school for learners with visual impairment, chiefly through an exploration of the experiences of management members of the inclusive process. The research is located within a qualitative research paradigm, which is subsumed by a phenomenological model. The data gathered through in-depth interviews include many anecdotal accounts that provide insight into the ways respondents reacted to experiences at the inclusive school. The main findings of the research are highlighted and discussed. Recommendations arising from a critical analysis of these main findings are presented.
- Full Text:
- Date Issued: 2002
- Authors: Cloete, Sanet
- Date: 2002
- Subjects: School management and organization -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1477 , http://hdl.handle.net/10962/d1003358
- Description: Special needs education has always provided special challenges to school administrators, policy makers and teachers. The world-wide move towards inclusive education as an alternative to exclusive education or casual mainstreaming has resulted in significant developments in Namibia in the past decade. Global educational reforms have focused on education for all as well as inclusive education and Namibia is signatory to several conventions and declarations in this regard. Research in this field has largely focused on the role of the inclusive teacher, and of course the special needs of the learners. Little or no attention has been paid to possible managerial and organisational challenges which accompany the move to inclusive education. This thesis seeks to critically investigate the managerial implications of inclusive education. The focal point of this research is to gain a clear understanding of the managerial implications in an inclusive school for learners with visual impairment, chiefly through an exploration of the experiences of management members of the inclusive process. The research is located within a qualitative research paradigm, which is subsumed by a phenomenological model. The data gathered through in-depth interviews include many anecdotal accounts that provide insight into the ways respondents reacted to experiences at the inclusive school. The main findings of the research are highlighted and discussed. Recommendations arising from a critical analysis of these main findings are presented.
- Full Text:
- Date Issued: 2002
Rumours of war : de-constructing media discourses of HIV/AIDS in South Africa
- Authors: Connelly, Mark
- Date: 2002
- Subjects: AIDS (Disease) -- South Africa AIDS (Disease) in mass media
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3177 , http://hdl.handle.net/10962/d1007844
- Description: This paper explores discourses of HIV/AIDS evident in a South African daily newspaper from 1985 to 2000, and discusses the implications of these in terms of the way in which HIV/AIDS is constructed in society. In this paper I utilize a Foucauldian analysis of the relationship between power and knowledge. The discursive framework of the war against HIV/AIDS is used to show how different groups of subjects are positioned in relations of power. Within this the power of western science and medicine is influential and supports and informs other discourses of HIV/AIDS. I argue that the discursive framework constructing HIV/AIDS as a war does far more than provide a useful vehicle within which HIV/AIDS can be understood as it supports certain institutions and groups of people above others. The paper concludes by identifying the silenced voices of women and dissidents, and calling for greater reflection concerning the critical analysis of current issues surrounding HIV/AIDS.
- Full Text:
- Date Issued: 2002
- Authors: Connelly, Mark
- Date: 2002
- Subjects: AIDS (Disease) -- South Africa AIDS (Disease) in mass media
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3177 , http://hdl.handle.net/10962/d1007844
- Description: This paper explores discourses of HIV/AIDS evident in a South African daily newspaper from 1985 to 2000, and discusses the implications of these in terms of the way in which HIV/AIDS is constructed in society. In this paper I utilize a Foucauldian analysis of the relationship between power and knowledge. The discursive framework of the war against HIV/AIDS is used to show how different groups of subjects are positioned in relations of power. Within this the power of western science and medicine is influential and supports and informs other discourses of HIV/AIDS. I argue that the discursive framework constructing HIV/AIDS as a war does far more than provide a useful vehicle within which HIV/AIDS can be understood as it supports certain institutions and groups of people above others. The paper concludes by identifying the silenced voices of women and dissidents, and calling for greater reflection concerning the critical analysis of current issues surrounding HIV/AIDS.
- Full Text:
- Date Issued: 2002
Workshop theatre in post-apartheid South Africa : a case study
- Authors: Copteros, Athina
- Date: 2002
- Subjects: Theater -- South Africa , Theater -- Political aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2156 , http://hdl.handle.net/10962/d1007477
- Description: This is a qualitative study exploring the use of workshop theatre in post-apartheid South Africa, with the objective of making a contribution to the knowledge-base regarding its use in current times. Workshop theatre is changing in response to a new socio-political reality and emerging trends in theatre practice. The case study, of developing a play on Oystercatchers with a Grahamstown group of artists, revealed the difficulties and challenges of using workshop theatre in this dynamic context. Data collection included a focus group, observation, reflective discussion and in-depth interviews that were analysed in relation to available literature on workshop theatre in apartheid and post-apartheid South Africa. It is proposed that workshop theatre has continued relevance in post -apartheid South Africa. The process of creating workshop theatre with diverse artists has great potential to transform relationships, address issues of personal identity and to provide an underlying purpose to a workshop theatre -making context.
- Full Text:
- Date Issued: 2002
- Authors: Copteros, Athina
- Date: 2002
- Subjects: Theater -- South Africa , Theater -- Political aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2156 , http://hdl.handle.net/10962/d1007477
- Description: This is a qualitative study exploring the use of workshop theatre in post-apartheid South Africa, with the objective of making a contribution to the knowledge-base regarding its use in current times. Workshop theatre is changing in response to a new socio-political reality and emerging trends in theatre practice. The case study, of developing a play on Oystercatchers with a Grahamstown group of artists, revealed the difficulties and challenges of using workshop theatre in this dynamic context. Data collection included a focus group, observation, reflective discussion and in-depth interviews that were analysed in relation to available literature on workshop theatre in apartheid and post-apartheid South Africa. It is proposed that workshop theatre has continued relevance in post -apartheid South Africa. The process of creating workshop theatre with diverse artists has great potential to transform relationships, address issues of personal identity and to provide an underlying purpose to a workshop theatre -making context.
- Full Text:
- Date Issued: 2002
Exploring the perceived value of work as part of psychosocial rehabilitation of the state patient : Komani Hospital, Queenstown
- Authors: Crocker, Ann Petro
- Date: 2002
- Subjects: Work -- Psychological aspects Mentally ill -- Attitudes
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:5953 , http://hdl.handle.net/10962/d1007464
- Description: During the research an attempt was made to gain an understanding of the perceived value of work in psychosocial rehabilitation with the Sate patient at Komani Hospital. The respondents' motivation to work and what they gain from working, was investigated, as well as the experience of the nonworking respondents and their motivation not to work. To achieve this, ten respondents who were working and ten respondents who were not working, were interviewed. This study involves only a limited number of State patients at Komani Hospital and therefore findings cannot be generalised and also because the study was done at one Hospital only. A literature study was undertaken during which it was evident that work as part of vocational rehabilitation contributed to the well being of the mentally disabled person. It was also stated in the literature that the disabled person must be actively involved in his/her own rehabilitation planning and that the person must make conscious decisions to move away from the "sick" role and participate in his/her rehabilitation process. Interview schedules were developed. Response received from the twenty participants was analysed. The overall findings of the study showed that the majority of respondents who were working, were motivated by money. The fact that the respondents work from Hospital and therefore disrupt the Hospital routine, work with abled co-workers and feeling needed by the factory where they are employed. also emphasised the respondents' motivation to keep on working. The findings of the study with the non-working group showed that some respondents want to work, but there are not enough work opportunities available in and from Hospital. The non-working respondents are not interested in working at the occupational therapy department because the pay patients get for work done at the department is too little, and therefore they reject the work there. Some respondents do not want to work. whether work is available or not. The non-working group is largely dependent on staff and co-patients for an income, or tobacco. The predominant activity of the non-working group of respondents during the day, as well as that of the majority of the working group respondents during weekends was sleeping, talking to friends, and smoking. The research findings, conclusions and recommendations could contribute to a better understanding of patients and the value of work for the patient in a Psychiatric Hospital.
- Full Text:
- Date Issued: 2002
- Authors: Crocker, Ann Petro
- Date: 2002
- Subjects: Work -- Psychological aspects Mentally ill -- Attitudes
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:5953 , http://hdl.handle.net/10962/d1007464
- Description: During the research an attempt was made to gain an understanding of the perceived value of work in psychosocial rehabilitation with the Sate patient at Komani Hospital. The respondents' motivation to work and what they gain from working, was investigated, as well as the experience of the nonworking respondents and their motivation not to work. To achieve this, ten respondents who were working and ten respondents who were not working, were interviewed. This study involves only a limited number of State patients at Komani Hospital and therefore findings cannot be generalised and also because the study was done at one Hospital only. A literature study was undertaken during which it was evident that work as part of vocational rehabilitation contributed to the well being of the mentally disabled person. It was also stated in the literature that the disabled person must be actively involved in his/her own rehabilitation planning and that the person must make conscious decisions to move away from the "sick" role and participate in his/her rehabilitation process. Interview schedules were developed. Response received from the twenty participants was analysed. The overall findings of the study showed that the majority of respondents who were working, were motivated by money. The fact that the respondents work from Hospital and therefore disrupt the Hospital routine, work with abled co-workers and feeling needed by the factory where they are employed. also emphasised the respondents' motivation to keep on working. The findings of the study with the non-working group showed that some respondents want to work, but there are not enough work opportunities available in and from Hospital. The non-working respondents are not interested in working at the occupational therapy department because the pay patients get for work done at the department is too little, and therefore they reject the work there. Some respondents do not want to work. whether work is available or not. The non-working group is largely dependent on staff and co-patients for an income, or tobacco. The predominant activity of the non-working group of respondents during the day, as well as that of the majority of the working group respondents during weekends was sleeping, talking to friends, and smoking. The research findings, conclusions and recommendations could contribute to a better understanding of patients and the value of work for the patient in a Psychiatric Hospital.
- Full Text:
- Date Issued: 2002
The growth and reproduction of the freshwater limpet Burnupia stenochorias (Pulmonata, Ancylidae), and an evaluation of its use as an ecotoxicology indicator in whole effluent testing
- Davies-Coleman, H D (Heather D)
- Authors: Davies-Coleman, H D (Heather D)
- Date: 2002
- Subjects: Ancylidae Effluent quality Toxicity testing
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5703 , http://hdl.handle.net/10962/d1005389
- Description: For the protection of the ecological Reserve in South Africa, the proposed introduction of compulsory toxicity testing in the licensing of effluent discharges necessitates the development of whole effluent toxicity testing. The elucidation of the effects of effluent on the local indigenous populations of organisms is essential before hazard and risk assessment can be undertaken. The limpet Burnupia stenochorias, prevalent in the Eastern Cape of South Africa, was chosen to represent the freshwater molluscs as a potential toxicity indicator. Using potassium dichromate (as a reference toxicant) and a textile whole effluent, the suitability of B. stenochorias was assessed under both acute and chronic toxicity conditions in the laboratory. In support of the toxicity studies, aspects of the biology of B. stenochorias were investigated under both natural and laboratory conditions. Using Principal Component and Discriminant Function Analyses, the relative shell morphometrics of three feral populations of B. stenochorias were found to vary. Length was shown to adequately represent growth of the shell, although the inclusion of width measurements is more statistically preferable. Two of the feral populations, one in impacted water, were studied weekly for 52 weeks to assess natural population dynamics. Based on the Von Bertalanffy Growth Equation, estimates of growth and longevity were made for this species, with growth highly seasonal. Age is not easily discerned from shell size. Egg laying occurred all year round, with early summer (peak egg lay), mid summer (a second, smaller peak in egg lay), and winter (limited presence of eggs) phases. In toxicity testing, consideration is given to the choice of the test organism based on age and sexual development. Consequently, the sexual development of B. stenochorias relative to shell length was determined with the aid of histological examinations of transverse sections of limpets, of all sizes, collected over one year. Limpets less than 3mm shell length were found to be immature in the development of the oocytes and spermatozoa, and were later chosen for acute toxicity tests. A laboratory diet was developed, for both culturing and maintaining of the limpets during toxicity tests; however, the diet requires optimisation. Under laboratory conditions, growth was linear, and individual fecundity highly variable. Successful methods for the collection of limpets from naturally occurring populations, and their acclimation to the laboratory were developed. Three B. stenochorias populations, representing different hydrological and water quality conditions, were compared to a laboratory population (maintained for three years) in their responses to the textile whole effluent and potassium dichromate. Under acute conditions, variability of mortality between limpet populations and between seasons was consistent with acceptable international standards. However, seasonal differences between feral limpets were apparent, with early summer limpets significantly more susceptible to both potassium dichromate and textile effluent than winter limpets. Although mortality occurred within the effluent at all concentrations, no 96 hour LC₅₀ values were obtained. The chronic toxicity effects of the textile whole effluent were assessed over the entire life cycle of B. stenochorias, based on survival, growth and reproductive effects. Lower concentrations of effluent (# 10%) gave greater variability of responses and toxicity than higher concentrations, with a 43 day LC₅₀ of 3.9% effluent. The No Observed Effect Concentrations for survival (over 43 days) were calculated in consecutive years as 0.1% and 1% effluent. Survival is considered a useful tool for determining toxicity endpoints using B. stenochorias. Limpet growth remained linear in effluent, with an apparent stimulation of growth at the 3-10% effluent concentration, confusing the toxicity and variability assessments. The possible addition of nutrients from the effluent points to either a potential inadequacy of the food quality provided in the chronic assessment, or the presence in the effluent of growth stimulants. Growth was also found to be too variable to allow adequate statistical conclusions about the toxicity of the effluent, although it is suggested that growth may be useful in the assessment of single compounds. Despite large individual variability in fecundity, statistical differences were discernible between effluent concentrations. The application of fecundity of B. stenochorias in hazard assessment therefore warrants further investigation. It was concluded that an assessment of textile whole effluent toxicity to B. stenochorias over an entire life cycle, and an F1 generation, is unnecessary. The development of the bucket/plastic bag method for both acute and chronic toxicity assessment of B. stenochorias was useful. In the final assessment of the usefulness of B. stenochorias as a toxicity indicator, toxicity endpoints were compared with those of the standard laboratory organism Daphnia pulex. Both in acute and chronic toxicity, B. stenochorias was found to be more sensitive. B. stenochorias is therefore considered valuable as a South African freshwater molluscan ecotoxicological indicator, with a place in hazard assessment, although further development and research is necessary before the limpet can be effectively used.
- Full Text:
- Date Issued: 2002
- Authors: Davies-Coleman, H D (Heather D)
- Date: 2002
- Subjects: Ancylidae Effluent quality Toxicity testing
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5703 , http://hdl.handle.net/10962/d1005389
- Description: For the protection of the ecological Reserve in South Africa, the proposed introduction of compulsory toxicity testing in the licensing of effluent discharges necessitates the development of whole effluent toxicity testing. The elucidation of the effects of effluent on the local indigenous populations of organisms is essential before hazard and risk assessment can be undertaken. The limpet Burnupia stenochorias, prevalent in the Eastern Cape of South Africa, was chosen to represent the freshwater molluscs as a potential toxicity indicator. Using potassium dichromate (as a reference toxicant) and a textile whole effluent, the suitability of B. stenochorias was assessed under both acute and chronic toxicity conditions in the laboratory. In support of the toxicity studies, aspects of the biology of B. stenochorias were investigated under both natural and laboratory conditions. Using Principal Component and Discriminant Function Analyses, the relative shell morphometrics of three feral populations of B. stenochorias were found to vary. Length was shown to adequately represent growth of the shell, although the inclusion of width measurements is more statistically preferable. Two of the feral populations, one in impacted water, were studied weekly for 52 weeks to assess natural population dynamics. Based on the Von Bertalanffy Growth Equation, estimates of growth and longevity were made for this species, with growth highly seasonal. Age is not easily discerned from shell size. Egg laying occurred all year round, with early summer (peak egg lay), mid summer (a second, smaller peak in egg lay), and winter (limited presence of eggs) phases. In toxicity testing, consideration is given to the choice of the test organism based on age and sexual development. Consequently, the sexual development of B. stenochorias relative to shell length was determined with the aid of histological examinations of transverse sections of limpets, of all sizes, collected over one year. Limpets less than 3mm shell length were found to be immature in the development of the oocytes and spermatozoa, and were later chosen for acute toxicity tests. A laboratory diet was developed, for both culturing and maintaining of the limpets during toxicity tests; however, the diet requires optimisation. Under laboratory conditions, growth was linear, and individual fecundity highly variable. Successful methods for the collection of limpets from naturally occurring populations, and their acclimation to the laboratory were developed. Three B. stenochorias populations, representing different hydrological and water quality conditions, were compared to a laboratory population (maintained for three years) in their responses to the textile whole effluent and potassium dichromate. Under acute conditions, variability of mortality between limpet populations and between seasons was consistent with acceptable international standards. However, seasonal differences between feral limpets were apparent, with early summer limpets significantly more susceptible to both potassium dichromate and textile effluent than winter limpets. Although mortality occurred within the effluent at all concentrations, no 96 hour LC₅₀ values were obtained. The chronic toxicity effects of the textile whole effluent were assessed over the entire life cycle of B. stenochorias, based on survival, growth and reproductive effects. Lower concentrations of effluent (# 10%) gave greater variability of responses and toxicity than higher concentrations, with a 43 day LC₅₀ of 3.9% effluent. The No Observed Effect Concentrations for survival (over 43 days) were calculated in consecutive years as 0.1% and 1% effluent. Survival is considered a useful tool for determining toxicity endpoints using B. stenochorias. Limpet growth remained linear in effluent, with an apparent stimulation of growth at the 3-10% effluent concentration, confusing the toxicity and variability assessments. The possible addition of nutrients from the effluent points to either a potential inadequacy of the food quality provided in the chronic assessment, or the presence in the effluent of growth stimulants. Growth was also found to be too variable to allow adequate statistical conclusions about the toxicity of the effluent, although it is suggested that growth may be useful in the assessment of single compounds. Despite large individual variability in fecundity, statistical differences were discernible between effluent concentrations. The application of fecundity of B. stenochorias in hazard assessment therefore warrants further investigation. It was concluded that an assessment of textile whole effluent toxicity to B. stenochorias over an entire life cycle, and an F1 generation, is unnecessary. The development of the bucket/plastic bag method for both acute and chronic toxicity assessment of B. stenochorias was useful. In the final assessment of the usefulness of B. stenochorias as a toxicity indicator, toxicity endpoints were compared with those of the standard laboratory organism Daphnia pulex. Both in acute and chronic toxicity, B. stenochorias was found to be more sensitive. B. stenochorias is therefore considered valuable as a South African freshwater molluscan ecotoxicological indicator, with a place in hazard assessment, although further development and research is necessary before the limpet can be effectively used.
- Full Text:
- Date Issued: 2002