Evaluation of the pharmaceutical availability of erythromycin from topical formulations
- Authors: Mandimika, Nyaradzo
- Date: 2008
- Subjects: Pharmacy -- Research Chromatographic analysis Gel permeation chromatography Gels (Pharmacy) Chemistry, analytic Acne -- Treatment Sebaceous glands -- Diseases -- Treatment Drugs -- Testing Erythromycin -- Bioavailability
- Language: English
- Type: Thesis , Masters , MPharm
- Identifier: vital:3771 , http://hdl.handle.net/10962/d1003249
- Description: Erythromycin (ERY) is a macrolide antibiotic which is used in the treatment of acne vulgaris.Acne is a common skin condition that occurs when the sebaceous glands and hair shafts become infected by the bacteria Propionibacterium acnes. Acne is a chronic condition that may last for years and the severity of the effects of the disease on patients is often undermined especially in third world countries where more emphasis is placed on other more life-threatening diseases. It may cause considerable physical and emotional distress to sufferers along with the possibility of permanent scarring. Although use of topical ERY formulations is not the first line of treatment it has proven to be effective in treating inflammation of skin and skin structures cause by the responsible bacteria. To-date there are a variety of vehicles which are used in preparing topical ERY formulations namely ointment and gel bases, alcoholic solutions and pledgets. All the gel formulations on the market contain hydroxypropyl cellulose, alcohol and water along with the active ingredient(s). However, some gel formulations contain propylene glycol in addition to these excipients an example being Emgel®. Propylene glycol has been shown to affect the penetration of topically applied drugs through the skin suggesting that it would be highly likely that those formulations which contain propylene glycol may release more ERY into the skin following application. With this in mind, two ERY gel formulations were produced which contained different percentages of propylene glycol. According to the FDA guidelines, pharmacokinetic measurements in blood, plasma and/or urine of topical dermatological drug products are not feasible to document bioequivalence since the active ingredient(s) in topical formulations is/are not intended to be absorbed into the systemic circulation and in addition, concentrations in extracutaneous biological tissues would generally not be measurable. This limits determination of bioavailability and assessment of bioequivalence of such products to pharmacodynamic measurements, clinical trials and dermatopharmacokinetic (DPK) measurements such as tape stripping (TS) and microdialysis (MD).TS is a sampling technique which involves sequential removal of layers of the stratum corneum using strips of adhesive tape. This technique has found increasing use in DPK studies for investigation of drug kinetics in the skin following the application of a topical formulation. The technique has also been used as a diagnostic tool in assessing the quality of the stratum corneum in diseased skin. In the current research study, the tape stripping technique was used to investigate the pharmaceutical/biological availability of topical gel formulations containing ERY. MD is another DPK sampling technique which has been used to determine the amount of a topically applied drug that penetrates through the stratum corneum to reach deeper tissues of the skin. The in vivo sampling technique involves the insertion of microdialysis probes beneath the skin surface in the dermal tissue and allows for real-time sampling of the analyte at its target site. Recently in vitro MD has also been successfully used to assess the pharmaceutical availability of a topical corticosteroid, mometesone furoate, from topical formulations. Based on this work, microdialysis was used to determine the pharmaceutical availability of ERY from gel formulations which were developed for use in this research. The results of the pharmaceutical availability of ERY from in vivo tape stripping studies and the in vitro microdialysis studies were compared to establish correlation between the data. Pharmaceutical equivalence and bioequivalence data obtained from the respective studies on the gel formulations were investigated by statistical analysis of the data generated from both the in vitro and in vivo experiments. In summary the objectives of this research were: 1. To develop and validate a high performance liquid chromatography method suitable to analyse ERY concentrations obtained from in vitro microdialysis studies and in vivo tape stripping studies. 2. To prepare two different ERY gel formulations with different percentage content of propylene glycol. 3. To determine the pharmaceutical availability of ERY from two different gel formulations using in vitro microdialysis. 4. To develop and validate a tape stripping technique which could be used to determine percutaneous penetration and bioequivalence of the gel formulations. 5. To compare in vitro microdialysis and in vivo tape stripping data and attempt to establish a correlation between the two different approaches.
- Full Text:
- Date Issued: 2008
- Authors: Mandimika, Nyaradzo
- Date: 2008
- Subjects: Pharmacy -- Research Chromatographic analysis Gel permeation chromatography Gels (Pharmacy) Chemistry, analytic Acne -- Treatment Sebaceous glands -- Diseases -- Treatment Drugs -- Testing Erythromycin -- Bioavailability
- Language: English
- Type: Thesis , Masters , MPharm
- Identifier: vital:3771 , http://hdl.handle.net/10962/d1003249
- Description: Erythromycin (ERY) is a macrolide antibiotic which is used in the treatment of acne vulgaris.Acne is a common skin condition that occurs when the sebaceous glands and hair shafts become infected by the bacteria Propionibacterium acnes. Acne is a chronic condition that may last for years and the severity of the effects of the disease on patients is often undermined especially in third world countries where more emphasis is placed on other more life-threatening diseases. It may cause considerable physical and emotional distress to sufferers along with the possibility of permanent scarring. Although use of topical ERY formulations is not the first line of treatment it has proven to be effective in treating inflammation of skin and skin structures cause by the responsible bacteria. To-date there are a variety of vehicles which are used in preparing topical ERY formulations namely ointment and gel bases, alcoholic solutions and pledgets. All the gel formulations on the market contain hydroxypropyl cellulose, alcohol and water along with the active ingredient(s). However, some gel formulations contain propylene glycol in addition to these excipients an example being Emgel®. Propylene glycol has been shown to affect the penetration of topically applied drugs through the skin suggesting that it would be highly likely that those formulations which contain propylene glycol may release more ERY into the skin following application. With this in mind, two ERY gel formulations were produced which contained different percentages of propylene glycol. According to the FDA guidelines, pharmacokinetic measurements in blood, plasma and/or urine of topical dermatological drug products are not feasible to document bioequivalence since the active ingredient(s) in topical formulations is/are not intended to be absorbed into the systemic circulation and in addition, concentrations in extracutaneous biological tissues would generally not be measurable. This limits determination of bioavailability and assessment of bioequivalence of such products to pharmacodynamic measurements, clinical trials and dermatopharmacokinetic (DPK) measurements such as tape stripping (TS) and microdialysis (MD).TS is a sampling technique which involves sequential removal of layers of the stratum corneum using strips of adhesive tape. This technique has found increasing use in DPK studies for investigation of drug kinetics in the skin following the application of a topical formulation. The technique has also been used as a diagnostic tool in assessing the quality of the stratum corneum in diseased skin. In the current research study, the tape stripping technique was used to investigate the pharmaceutical/biological availability of topical gel formulations containing ERY. MD is another DPK sampling technique which has been used to determine the amount of a topically applied drug that penetrates through the stratum corneum to reach deeper tissues of the skin. The in vivo sampling technique involves the insertion of microdialysis probes beneath the skin surface in the dermal tissue and allows for real-time sampling of the analyte at its target site. Recently in vitro MD has also been successfully used to assess the pharmaceutical availability of a topical corticosteroid, mometesone furoate, from topical formulations. Based on this work, microdialysis was used to determine the pharmaceutical availability of ERY from gel formulations which were developed for use in this research. The results of the pharmaceutical availability of ERY from in vivo tape stripping studies and the in vitro microdialysis studies were compared to establish correlation between the data. Pharmaceutical equivalence and bioequivalence data obtained from the respective studies on the gel formulations were investigated by statistical analysis of the data generated from both the in vitro and in vivo experiments. In summary the objectives of this research were: 1. To develop and validate a high performance liquid chromatography method suitable to analyse ERY concentrations obtained from in vitro microdialysis studies and in vivo tape stripping studies. 2. To prepare two different ERY gel formulations with different percentage content of propylene glycol. 3. To determine the pharmaceutical availability of ERY from two different gel formulations using in vitro microdialysis. 4. To develop and validate a tape stripping technique which could be used to determine percutaneous penetration and bioequivalence of the gel formulations. 5. To compare in vitro microdialysis and in vivo tape stripping data and attempt to establish a correlation between the two different approaches.
- Full Text:
- Date Issued: 2008
Excavating the 'critique' : an investigation into disjunctions between the espoused and the practiced within a Fine Art studio practice curriculum
- Authors: Belluigi, Dina Zoe
- Date: 2008
- Subjects: Art -- Study and teaching (Higher) Postmodernism and education Universities and colleges -- Philosophy Universities and colleges -- Curricula Education, Higher -- Political aspects Creative thinking -- Study and teaching Discourse analysis -- Methodology Critical pedagogy
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1531 , http://hdl.handle.net/10962/d1003413
- Description: This report presents the findings of a case study excavating the event of the ‘Critique’ (crit), the formative assessment method within a Fine Art Studio Practice curriculum. Arguments informed by critical postmodernism, education theories and contemporary art criticism are utilised to construct a dialectic of higher education, contemporary art and fine art studio practice. An emphasis is placed on the importance of agency, expressed through intentionality and critical thinking, with a recognition of the relationship between ‘the self’ and ‘the other’. Using critical discourse analysis, the disjunctions between the espoused and practiced curriculum are explored. The researcher analyses how the assessment practices of the case studied are influenced by unexamined agentic factors, such as inter-departmental relations, lecturers’ assumptions and prior learning, and structural determinants, such as the medium-specific Bachelor of Fine Art degree structure and prevailing artistic traditions. The research findings indicate that these are underpinned by tensions between two orientations, the espoused curriculum’s discourse-interest informed by critical theory, and the theory-in-use. The latter is shown to have unexamined modernist leanings towards formalism and a master-apprentice relationship between lecturer and students, which encourages reproduction rather than critical, creative thinking. The dominant discourses in the case studied construct a negative dialectic of the artist-student that can be seen to deny student agency and authorial responsibility. Findings suggest that students experience this as alienating, to the extent that to preserve their sense of self, they adopted surface and strategic approaches to learning. An argument is made for lecturers’ critically reflexive engagement with their teaching practice, and thereby to model ethical relationships between ‘self’ and ‘other’ during ‘crits’. In addition, emphasis is placed on how assessment practices should be more aligned with the espoused curriculum, so that the importance of a reflexive relationship between form and content, process and product, intentionality and interpretation is acknowledged.
- Full Text:
- Date Issued: 2008
- Authors: Belluigi, Dina Zoe
- Date: 2008
- Subjects: Art -- Study and teaching (Higher) Postmodernism and education Universities and colleges -- Philosophy Universities and colleges -- Curricula Education, Higher -- Political aspects Creative thinking -- Study and teaching Discourse analysis -- Methodology Critical pedagogy
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1531 , http://hdl.handle.net/10962/d1003413
- Description: This report presents the findings of a case study excavating the event of the ‘Critique’ (crit), the formative assessment method within a Fine Art Studio Practice curriculum. Arguments informed by critical postmodernism, education theories and contemporary art criticism are utilised to construct a dialectic of higher education, contemporary art and fine art studio practice. An emphasis is placed on the importance of agency, expressed through intentionality and critical thinking, with a recognition of the relationship between ‘the self’ and ‘the other’. Using critical discourse analysis, the disjunctions between the espoused and practiced curriculum are explored. The researcher analyses how the assessment practices of the case studied are influenced by unexamined agentic factors, such as inter-departmental relations, lecturers’ assumptions and prior learning, and structural determinants, such as the medium-specific Bachelor of Fine Art degree structure and prevailing artistic traditions. The research findings indicate that these are underpinned by tensions between two orientations, the espoused curriculum’s discourse-interest informed by critical theory, and the theory-in-use. The latter is shown to have unexamined modernist leanings towards formalism and a master-apprentice relationship between lecturer and students, which encourages reproduction rather than critical, creative thinking. The dominant discourses in the case studied construct a negative dialectic of the artist-student that can be seen to deny student agency and authorial responsibility. Findings suggest that students experience this as alienating, to the extent that to preserve their sense of self, they adopted surface and strategic approaches to learning. An argument is made for lecturers’ critically reflexive engagement with their teaching practice, and thereby to model ethical relationships between ‘self’ and ‘other’ during ‘crits’. In addition, emphasis is placed on how assessment practices should be more aligned with the espoused curriculum, so that the importance of a reflexive relationship between form and content, process and product, intentionality and interpretation is acknowledged.
- Full Text:
- Date Issued: 2008
Experiences and coping resources of the suicide negotiation staff at the Van Staden's Bridge
- Authors: Botha, Miranda
- Date: 2008
- Subjects: Adjustment (Psychology) , Negotiation , Suicide -- Prevention
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9926 , http://hdl.handle.net/10948/656 , Adjustment (Psychology) , Negotiation , Suicide -- Prevention
- Description: The Van Staden’s Bridge has claimed 67 lives since its construction on 11 November 1971. A team of police officials, trained as negotiators who deal with suicide and hostage negotiation, are involved with the task of convincing suicidal persons who turn to the bridge to take their own lives, not to resort to suicide. They are responsible for persuading at least three people per week to reconisider suicide at this notorious bridge. The goal of this study was to explore and describe the experiences and coping resources of the SAPS suicide negotiation staff at the Van Staden’s Bridge, Thornhill, Port Elizabeth. A mixed methods study combining both the quantitative and qualitative approaches was implemented. An exploratory-descriptive design was used, because the topic is still a relatively under-researched area in South Africa. Two data collection measures, that is, the Coping Resources Inventory (CRI) and semi-structured interviewing were employed. The researcher conducted a pilot study to enhance the trustworthiness of the study. Non-probability, purposive sampling was employed to obtain research participants from the research population (suicide negotiation team), consisting of 12 members. Eight members participated voluntary in the quantitative data collection and of these a total of five participated in the qualitative research interviews. Six themes emerged from the results of the in-depth, semi-structured interviews: (1) experiences of SAPS suicide negotiators, (2) aspects that hinder the negotiation process, (3) characteristics of a negotiator, (4) important aspects of the negotiation process, (5) coping mechanisms of SAPS negotiators and (6) recommendations for rendering support to SAPS negotiators. The results from the CRI suggested that the participants have average coping resources with the cognitive domain being the lowest and both the social and physical domains being the highest. The limitations and the value of the study were outlined and finally, recommendations for future research were made.
- Full Text:
- Date Issued: 2008
- Authors: Botha, Miranda
- Date: 2008
- Subjects: Adjustment (Psychology) , Negotiation , Suicide -- Prevention
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9926 , http://hdl.handle.net/10948/656 , Adjustment (Psychology) , Negotiation , Suicide -- Prevention
- Description: The Van Staden’s Bridge has claimed 67 lives since its construction on 11 November 1971. A team of police officials, trained as negotiators who deal with suicide and hostage negotiation, are involved with the task of convincing suicidal persons who turn to the bridge to take their own lives, not to resort to suicide. They are responsible for persuading at least three people per week to reconisider suicide at this notorious bridge. The goal of this study was to explore and describe the experiences and coping resources of the SAPS suicide negotiation staff at the Van Staden’s Bridge, Thornhill, Port Elizabeth. A mixed methods study combining both the quantitative and qualitative approaches was implemented. An exploratory-descriptive design was used, because the topic is still a relatively under-researched area in South Africa. Two data collection measures, that is, the Coping Resources Inventory (CRI) and semi-structured interviewing were employed. The researcher conducted a pilot study to enhance the trustworthiness of the study. Non-probability, purposive sampling was employed to obtain research participants from the research population (suicide negotiation team), consisting of 12 members. Eight members participated voluntary in the quantitative data collection and of these a total of five participated in the qualitative research interviews. Six themes emerged from the results of the in-depth, semi-structured interviews: (1) experiences of SAPS suicide negotiators, (2) aspects that hinder the negotiation process, (3) characteristics of a negotiator, (4) important aspects of the negotiation process, (5) coping mechanisms of SAPS negotiators and (6) recommendations for rendering support to SAPS negotiators. The results from the CRI suggested that the participants have average coping resources with the cognitive domain being the lowest and both the social and physical domains being the highest. The limitations and the value of the study were outlined and finally, recommendations for future research were made.
- Full Text:
- Date Issued: 2008
Exploring approaches to teaching reading skills in English at senior phase in secondary schools in Mbizana district in the Eastern Cape: a case study
- Masilo, Appolonia Nteboheleng
- Authors: Masilo, Appolonia Nteboheleng
- Date: 2008
- Subjects: Reading (Secondary) -- South Africa -- Eastern Cape Province
- Language: English
- Type: Thesis , Masters , M Ed
- Identifier: vital:16161 , http://hdl.handle.net/10353/204 , Reading (Secondary) -- South Africa -- Eastern Cape Province
- Description: During the process of this research, the main objective was to explore the approaches that the teachers use to teach reading in English First Additional Language (FAL) in senior phase at General Education and Training (GET). This was due to the observed weak performance of learners in reading, especially in GET phases. To achieve this, 20 participants tha t consisted of 4 English FAL teachers and 16 learners of grades 8 and 9 were selected. The research focused on teacher perceptions and implementation of language teaching approaches. Learners were involved in the research in order to see whether the used approaches give learners a balanced experience of intensive and extensive programmes. The study found that there were a number of factors that contributed to the learners’ weak performance in reading. These included, among others, lack of balance between intensive and extensive reading programmes, with intensive reading getting more attention than extensive reading; lack of reading material in schools, especially for further exposure, pleasure and amusement; little or no exposure of learners to wider reading; inadequate teacher pre-service and inservice reading programmes; teachers’ misconception of extensive reading; learners’ home environment that does not encourage reading; lack of parental support and community involvement. These all affected negatively the learners’ v development of reading skills. The study made some recommendations for the improvement of teacher education programmes and reading resources in schools and communities. schools.
- Full Text:
- Date Issued: 2008
- Authors: Masilo, Appolonia Nteboheleng
- Date: 2008
- Subjects: Reading (Secondary) -- South Africa -- Eastern Cape Province
- Language: English
- Type: Thesis , Masters , M Ed
- Identifier: vital:16161 , http://hdl.handle.net/10353/204 , Reading (Secondary) -- South Africa -- Eastern Cape Province
- Description: During the process of this research, the main objective was to explore the approaches that the teachers use to teach reading in English First Additional Language (FAL) in senior phase at General Education and Training (GET). This was due to the observed weak performance of learners in reading, especially in GET phases. To achieve this, 20 participants tha t consisted of 4 English FAL teachers and 16 learners of grades 8 and 9 were selected. The research focused on teacher perceptions and implementation of language teaching approaches. Learners were involved in the research in order to see whether the used approaches give learners a balanced experience of intensive and extensive programmes. The study found that there were a number of factors that contributed to the learners’ weak performance in reading. These included, among others, lack of balance between intensive and extensive reading programmes, with intensive reading getting more attention than extensive reading; lack of reading material in schools, especially for further exposure, pleasure and amusement; little or no exposure of learners to wider reading; inadequate teacher pre-service and inservice reading programmes; teachers’ misconception of extensive reading; learners’ home environment that does not encourage reading; lack of parental support and community involvement. These all affected negatively the learners’ v development of reading skills. The study made some recommendations for the improvement of teacher education programmes and reading resources in schools and communities. schools.
- Full Text:
- Date Issued: 2008
Exploring attitudes towards banner advertising on the world wide web
- Authors: Krige, Philip
- Date: 2008
- Subjects: Internet advertising -- Banner , Internet users -- Banner , Internet marketing
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8705 , http://hdl.handle.net/10948/997 , Internet advertising -- Banner , Internet users -- Banner , Internet marketing
- Description: The purpose of the study was to assess the effectiveness of banner advertising on the World Wide Web, as well as to explore and analyse the attitudes and behaviours of internet users towards banner advertising. The research objective was to determine, why people do not click on banners and to find ways in which advertisers can make banner advertisements appeal to consumers more effectively. Outcomes of the research suggested which features advertisers should avoid when developing clickable banners. An extensive literature review was carried out in order to highlight important aspects of historic research. The analysis conducted on this topic indicated that a gap exists in the area of public attitudes towards clickable banner advertising and the reasons why people avoid clicking on banners. To address the above questions, peoples’ attitudes towards banner and other Internet advertising were investigated through focus group interviews and surveys. The findings suggest that the main reason for the ignorance surrounding clickable banners was the low involvement between the product or service being advertised and the viewer’s interests. Other reasons included the high annoyance level of banner advertising and the threat of viruses that some banners may pose. Conclusions of the research recommend narrow targeting and personalisation of banner advertisements, constant rotations and replacements of banners to avoid burnouts as well as trustful and original appeal and content. Other important findings included: • The majority of people are indifferent towards banners, • People with less than three years of Internet experience tend to click more than people with more than three years of Internet experience, • Females showed more “clickable behaviour” than males, • People are more likely to click on banners which present interesting information, are bright and animated or promote catchy phrases for the surfer, • People prefer to see banners located on the top of the page or on the right side of the page, • Pop-ups are the most noticeable and are possibly the route cause of what triggers people to become annoyed or dislike banner ads, Findings of this research have high social value. If advertisers would take into account the results of the current study, they would be able to create more effective banners, which could effectively be redirected to the appropriate target market. This will enable them to cut their costs. Furthermore, online users would enjoy a more polite and friendly online environment, where their interests will be taken into account, which would diminish the current gap between customers and advertisers.
- Full Text:
- Date Issued: 2008
- Authors: Krige, Philip
- Date: 2008
- Subjects: Internet advertising -- Banner , Internet users -- Banner , Internet marketing
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8705 , http://hdl.handle.net/10948/997 , Internet advertising -- Banner , Internet users -- Banner , Internet marketing
- Description: The purpose of the study was to assess the effectiveness of banner advertising on the World Wide Web, as well as to explore and analyse the attitudes and behaviours of internet users towards banner advertising. The research objective was to determine, why people do not click on banners and to find ways in which advertisers can make banner advertisements appeal to consumers more effectively. Outcomes of the research suggested which features advertisers should avoid when developing clickable banners. An extensive literature review was carried out in order to highlight important aspects of historic research. The analysis conducted on this topic indicated that a gap exists in the area of public attitudes towards clickable banner advertising and the reasons why people avoid clicking on banners. To address the above questions, peoples’ attitudes towards banner and other Internet advertising were investigated through focus group interviews and surveys. The findings suggest that the main reason for the ignorance surrounding clickable banners was the low involvement between the product or service being advertised and the viewer’s interests. Other reasons included the high annoyance level of banner advertising and the threat of viruses that some banners may pose. Conclusions of the research recommend narrow targeting and personalisation of banner advertisements, constant rotations and replacements of banners to avoid burnouts as well as trustful and original appeal and content. Other important findings included: • The majority of people are indifferent towards banners, • People with less than three years of Internet experience tend to click more than people with more than three years of Internet experience, • Females showed more “clickable behaviour” than males, • People are more likely to click on banners which present interesting information, are bright and animated or promote catchy phrases for the surfer, • People prefer to see banners located on the top of the page or on the right side of the page, • Pop-ups are the most noticeable and are possibly the route cause of what triggers people to become annoyed or dislike banner ads, Findings of this research have high social value. If advertisers would take into account the results of the current study, they would be able to create more effective banners, which could effectively be redirected to the appropriate target market. This will enable them to cut their costs. Furthermore, online users would enjoy a more polite and friendly online environment, where their interests will be taken into account, which would diminish the current gap between customers and advertisers.
- Full Text:
- Date Issued: 2008
Exploring the construct-related validity of the eye and hand coordination subscale of the Griffiths Mental Development Scales-Extended revised (GMDS-ER)
- Authors: Povey, Jenny-Louise
- Date: 2008
- Subjects: Griffiths Scales of Mental Development , Mental development -- Testing , Psychological tests for children , Children -- Intelligence testing -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9923 , http://hdl.handle.net/10948/661 , Griffiths Scales of Mental Development , Mental development -- Testing , Psychological tests for children , Children -- Intelligence testing -- South Africa
- Description: To constantly add to our understanding of child development, a valid, comprehensive, well-researched measure is needed. The recent revision and standardisation of the Griffiths Mental Development Scales - Extended Revised (GMDS-ER) has necessitated investigations into its psychometric properties. This measure is used to identify developmental delays in children and critical decisions may be made, hence it is imperative that this measure be deemed both reliable and valid. This study aimed to contribute to the broader restandardisation project and focussed on gathering qualitative and quantitative construct-related validity evidence for one of the six Subscales of the GMDS-ER, namely the Eye and Hand Coordination Subscale (Subscale D). An exploratory descriptive method using a triangulation approach was used to explore the construct-related validity evidence of the Eye and Hand Coordination Subscale. A non-random purposively selected sample of 6 experts, who had worked at least 10 years with children assessing and evaluating the domain of eye-hand coordination, participated in a facet analysis to identify the underlying dimensions tapped by the Eye and Hand Coordination Subscale. The sample for the quantitative aspects of this study, the empirical validation of the construct model, was collected as part of the broader restandardisation and represented a stratified sample of 1026 children between the ages 24 months and 96 months from across the United Kingdom and Eire. Three measures, namely a biographical questionnaire, the GMDS-ER and a construct evaluation form were used to gather the qualitative and quantitative data. The qualitative data was analysed by means of a facet analysis and literature control which included examining other tests or subtests that tapped eye-hand coordination skills. The quantitative data was analysed by means of exploratory common factor analysis using oblique (DQUART) rotation in order to verify the qualitatively identified construct model by specifying a one-factor solution for each underlying construct. While literature suggests that eye-hand coordination is multidimensional in nature the facet analysis revealed that the tasks tapped by Subscale D were not tapping complex skills aside from eye-hand coordination. The facet analysis thus revealed that all the items tap the eye-hand coordination of fine motor tasks and that these items could be grouped into two categories, using writing utensils and object manipulation. The results from the factor analysis confirmed that the items on Subscale D have one underlying construct and further exploration confirmed that these items could in fact be grouped into two categories. The coefficients of congruence for SES and gender were satisfactory and thus the construct model was validated across these groups as well. The study has provided extensive qualitative and quantitative evidence for the construct-related validity of the Eye and Hand Coordination Subscale of the GMDS-ER, thus validating its use as a sound measure of eye-hand coordination development in children aged 2 to 8 years. The content coverage however, seemed to indicate that the tasks required do not adequately cover all the facets of eye-hand coordination and some of these item types are tapped by the other Subscales in the measure. Hence, should the Subscale be used as an independent assessment of eye-hand coordination, the eye-hand coordination development of the child would have a narrow focus. In addition, in reviewing the variety of tasks in the two sections for the older and younger child, the researcher noted that while section III tapped a variety of skills, section IV only focused on skills associated with drawing, copying and writing. A review of the age appropriateness of the items and the item analysis results from the revision seemed to indicate that some of the items assessing the older child may need to be revised. Further, the researcher suggested that the revision should consider adding additional dimensions to the tasks assessed. Overall, it is the researcher‟s opinion that this Subscale was not given adequate attention during the revision process and should future revisions occur, the recommendations from this study should be considered.
- Full Text:
- Date Issued: 2008
- Authors: Povey, Jenny-Louise
- Date: 2008
- Subjects: Griffiths Scales of Mental Development , Mental development -- Testing , Psychological tests for children , Children -- Intelligence testing -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9923 , http://hdl.handle.net/10948/661 , Griffiths Scales of Mental Development , Mental development -- Testing , Psychological tests for children , Children -- Intelligence testing -- South Africa
- Description: To constantly add to our understanding of child development, a valid, comprehensive, well-researched measure is needed. The recent revision and standardisation of the Griffiths Mental Development Scales - Extended Revised (GMDS-ER) has necessitated investigations into its psychometric properties. This measure is used to identify developmental delays in children and critical decisions may be made, hence it is imperative that this measure be deemed both reliable and valid. This study aimed to contribute to the broader restandardisation project and focussed on gathering qualitative and quantitative construct-related validity evidence for one of the six Subscales of the GMDS-ER, namely the Eye and Hand Coordination Subscale (Subscale D). An exploratory descriptive method using a triangulation approach was used to explore the construct-related validity evidence of the Eye and Hand Coordination Subscale. A non-random purposively selected sample of 6 experts, who had worked at least 10 years with children assessing and evaluating the domain of eye-hand coordination, participated in a facet analysis to identify the underlying dimensions tapped by the Eye and Hand Coordination Subscale. The sample for the quantitative aspects of this study, the empirical validation of the construct model, was collected as part of the broader restandardisation and represented a stratified sample of 1026 children between the ages 24 months and 96 months from across the United Kingdom and Eire. Three measures, namely a biographical questionnaire, the GMDS-ER and a construct evaluation form were used to gather the qualitative and quantitative data. The qualitative data was analysed by means of a facet analysis and literature control which included examining other tests or subtests that tapped eye-hand coordination skills. The quantitative data was analysed by means of exploratory common factor analysis using oblique (DQUART) rotation in order to verify the qualitatively identified construct model by specifying a one-factor solution for each underlying construct. While literature suggests that eye-hand coordination is multidimensional in nature the facet analysis revealed that the tasks tapped by Subscale D were not tapping complex skills aside from eye-hand coordination. The facet analysis thus revealed that all the items tap the eye-hand coordination of fine motor tasks and that these items could be grouped into two categories, using writing utensils and object manipulation. The results from the factor analysis confirmed that the items on Subscale D have one underlying construct and further exploration confirmed that these items could in fact be grouped into two categories. The coefficients of congruence for SES and gender were satisfactory and thus the construct model was validated across these groups as well. The study has provided extensive qualitative and quantitative evidence for the construct-related validity of the Eye and Hand Coordination Subscale of the GMDS-ER, thus validating its use as a sound measure of eye-hand coordination development in children aged 2 to 8 years. The content coverage however, seemed to indicate that the tasks required do not adequately cover all the facets of eye-hand coordination and some of these item types are tapped by the other Subscales in the measure. Hence, should the Subscale be used as an independent assessment of eye-hand coordination, the eye-hand coordination development of the child would have a narrow focus. In addition, in reviewing the variety of tasks in the two sections for the older and younger child, the researcher noted that while section III tapped a variety of skills, section IV only focused on skills associated with drawing, copying and writing. A review of the age appropriateness of the items and the item analysis results from the revision seemed to indicate that some of the items assessing the older child may need to be revised. Further, the researcher suggested that the revision should consider adding additional dimensions to the tasks assessed. Overall, it is the researcher‟s opinion that this Subscale was not given adequate attention during the revision process and should future revisions occur, the recommendations from this study should be considered.
- Full Text:
- Date Issued: 2008
Facilitating reflection in post-graduate writing practice
- Authors: Naidoo, Nadasen Arungasen
- Date: 2008
- Subjects: Academic writing , Report writing , Academic writing -- Study and teaching (Higher) -- South Africa , Written communication -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: vital:9473 , http://hdl.handle.net/10948/688 , Academic writing , Report writing , Academic writing -- Study and teaching (Higher) -- South Africa , Written communication -- Study and teaching -- South Africa
- Description: University teaching staff are employed because of their knowledge in their particular disciplines. Many do not have a qualification to teach at a higher education institution upon commencement of their academic career. In that group there are few who have the research experience required to assist at postgraduate level. This should be developed as one of the three core activities of higher education, in which they have to be involved. This study is the result of a problem that I encountered as a higher education practitioner. In keeping with my being a practitioner researcher within an action research paradigm, this report is written mainly in the first person. The study reports on how my personal theories grew over a period resulting in the need to constantly improve my own practice. These personal theories culminated in the development of an instrument (ADaM), to assess writing. ADaM was used primarily to facilitate reflection in post-graduate writing practice. In this study, there were three sets of workshops comprising 13 practical sessions each, where lecturers engaged with the process of reading, writing, computer-mediation and, to a limited extent, with the concept of mentorship. The purpose was to answer the research question: Can a writing assessment instrument be used to sensitise staff teaching post-graduates to reflect on the complex nature of producing and assessing academic writing? At two points during the 13 practical sessions, data was gathered through semistructured interviews. The data has been analysed using a form of grounded theory referred to as remodeled grounded theory. Since the analysis traversed both the quantitative and qualitative paradigms of research, it was necessary also to place the study within the third paradigm, referred to as mixed methods research. The analysis has been presented via a series of relationships generated first by open coding, then axial coding and concludes with selective coding. In addition, the comments of an independent coder were used to validate the analysis. In accordance with classic grounded theory, it was only after the analysis of the data and the emergence of a substantive theory that I referred to existing theory in the penultimate chapter as validation of my findings. The findings from the study, together with existing literature, allowed me to conclude that “Creating an awareness of writing assessment sensitises academics to their roles as HE practitioners particularly in the areas of writing and mentorship in post-graduate supervision”.
- Full Text:
- Date Issued: 2008
- Authors: Naidoo, Nadasen Arungasen
- Date: 2008
- Subjects: Academic writing , Report writing , Academic writing -- Study and teaching (Higher) -- South Africa , Written communication -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: vital:9473 , http://hdl.handle.net/10948/688 , Academic writing , Report writing , Academic writing -- Study and teaching (Higher) -- South Africa , Written communication -- Study and teaching -- South Africa
- Description: University teaching staff are employed because of their knowledge in their particular disciplines. Many do not have a qualification to teach at a higher education institution upon commencement of their academic career. In that group there are few who have the research experience required to assist at postgraduate level. This should be developed as one of the three core activities of higher education, in which they have to be involved. This study is the result of a problem that I encountered as a higher education practitioner. In keeping with my being a practitioner researcher within an action research paradigm, this report is written mainly in the first person. The study reports on how my personal theories grew over a period resulting in the need to constantly improve my own practice. These personal theories culminated in the development of an instrument (ADaM), to assess writing. ADaM was used primarily to facilitate reflection in post-graduate writing practice. In this study, there were three sets of workshops comprising 13 practical sessions each, where lecturers engaged with the process of reading, writing, computer-mediation and, to a limited extent, with the concept of mentorship. The purpose was to answer the research question: Can a writing assessment instrument be used to sensitise staff teaching post-graduates to reflect on the complex nature of producing and assessing academic writing? At two points during the 13 practical sessions, data was gathered through semistructured interviews. The data has been analysed using a form of grounded theory referred to as remodeled grounded theory. Since the analysis traversed both the quantitative and qualitative paradigms of research, it was necessary also to place the study within the third paradigm, referred to as mixed methods research. The analysis has been presented via a series of relationships generated first by open coding, then axial coding and concludes with selective coding. In addition, the comments of an independent coder were used to validate the analysis. In accordance with classic grounded theory, it was only after the analysis of the data and the emergence of a substantive theory that I referred to existing theory in the penultimate chapter as validation of my findings. The findings from the study, together with existing literature, allowed me to conclude that “Creating an awareness of writing assessment sensitises academics to their roles as HE practitioners particularly in the areas of writing and mentorship in post-graduate supervision”.
- Full Text:
- Date Issued: 2008
Factors influencing interracial mixing amongst university students
- Authors: Flusk, Lynette Michelle
- Date: 2008
- Subjects: Spatial behavior , Social distance , Students -- South Africa -- Attitudes , Prejudice (Psychology) , College integration -- South Africa , Colleges and universities -- South Africa -- Social conditions
- Language: English
- Type: Thesis , Masters , M Soc Sc (C Psy)
- Identifier: vital:11849 , http://hdl.handle.net/10353/150 , Spatial behavior , Social distance , Students -- South Africa -- Attitudes , Prejudice (Psychology) , College integration -- South Africa , Colleges and universities -- South Africa -- Social conditions
- Description: This study examines the reasons given for the lack of interracial contact among 188 (142 Black, 25 White and 19 Coloured) university students. The most pervasive factor influencing such contact for the whole group (79.1 percent) was language differences. The statements endorsed by most black participants were; differences in behaviour (62.9 percent), socio-economic status (56.0 percent) and culture (52.5 percent). The coloured participants endorsed statements concerning socio-economic status (61.1 percent), culture (42.1 percent) and dissociation (42.1 percent). The white participants endorsed statements regarding race issues (64.0 percent), differences in behaviour (60.0 percent) and cultural differences (44.0 percent). This study found that metastereotypes social distance and contact correlate with prejudice. Metastereotypes and social distance positively influence prejudice in that an increase in these factors is associated with heightened levels of prejudice. The amount of contact between groups has a negative relationship with prejudice, indicating that increased levels of contact are associated with a decrease in prejudice.
- Full Text:
- Date Issued: 2008
- Authors: Flusk, Lynette Michelle
- Date: 2008
- Subjects: Spatial behavior , Social distance , Students -- South Africa -- Attitudes , Prejudice (Psychology) , College integration -- South Africa , Colleges and universities -- South Africa -- Social conditions
- Language: English
- Type: Thesis , Masters , M Soc Sc (C Psy)
- Identifier: vital:11849 , http://hdl.handle.net/10353/150 , Spatial behavior , Social distance , Students -- South Africa -- Attitudes , Prejudice (Psychology) , College integration -- South Africa , Colleges and universities -- South Africa -- Social conditions
- Description: This study examines the reasons given for the lack of interracial contact among 188 (142 Black, 25 White and 19 Coloured) university students. The most pervasive factor influencing such contact for the whole group (79.1 percent) was language differences. The statements endorsed by most black participants were; differences in behaviour (62.9 percent), socio-economic status (56.0 percent) and culture (52.5 percent). The coloured participants endorsed statements concerning socio-economic status (61.1 percent), culture (42.1 percent) and dissociation (42.1 percent). The white participants endorsed statements regarding race issues (64.0 percent), differences in behaviour (60.0 percent) and cultural differences (44.0 percent). This study found that metastereotypes social distance and contact correlate with prejudice. Metastereotypes and social distance positively influence prejudice in that an increase in these factors is associated with heightened levels of prejudice. The amount of contact between groups has a negative relationship with prejudice, indicating that increased levels of contact are associated with a decrease in prejudice.
- Full Text:
- Date Issued: 2008
Faktore wat die oorlewing van volstruiskuikens (Struthio Camelus) verhoog
- Authors: Janse Van Vuuren, Maryke
- Date: 2008
- Subjects: Ostrich farming -- South Africa , Ostriches -- Breeding -- South Africa
- Language: Afrikaans
- Type: Thesis , Masters , MTech
- Identifier: vital:10588 , http://hdl.handle.net/10948/848 , Ostrich farming -- South Africa , Ostriches -- Breeding -- South Africa
- Description: Hierdie verhandeling is ‘n samestelling van verskeie studies, elk opgeskryf in die formaat en styl soos vereis deur die Suid-Afrikaanse Vereeniging vir Diereproduksie (South African Society of Animal Science). Hoofstuk 1 is ‘n literatuurstudie bestaande uit ‘n algemene inleiding wat agtergrond oor die studie verskaf en sluit die probleemstelling in, naamlik die swak oorlewing van volstruiskuikens wat onder kunsmatige toestande grootgemaak word. Hoofstukke 2, 3, 4 en 5 bestaan uit die eerste vier studies, waartydens sekere bestuurs-aspekte, wat moontlik oorlewing van volstruiskuikens kan verbeter (nl: populasiedigtheid, tipe vloer-oppervlak, die aanwending van broeipare en die aanwending van peetouers), ondersoek is. Hoofstukke 6, 7, 8 & 9 handel oor studies wat gerig is om voeding meer aanloklik te maak vir volstruiskuikens teneinde voedselinname te stimuleer en sodoende produksie en oorlewing te verbeter (nl: verskaffing van groenvoer, geur van voer, kleur van voer en beligting van voer). Die laaste hoofstuk bestaan uit ‘n algemene gevolgtrekking en aanbevelings. Alhoewel daar gepoog is om herhaling in hoofstukke te beperk, was dit onmoontlik om herhaling van sekere gedeeltes van hoofstukke te voorkom.
- Full Text:
- Date Issued: 2008
- Authors: Janse Van Vuuren, Maryke
- Date: 2008
- Subjects: Ostrich farming -- South Africa , Ostriches -- Breeding -- South Africa
- Language: Afrikaans
- Type: Thesis , Masters , MTech
- Identifier: vital:10588 , http://hdl.handle.net/10948/848 , Ostrich farming -- South Africa , Ostriches -- Breeding -- South Africa
- Description: Hierdie verhandeling is ‘n samestelling van verskeie studies, elk opgeskryf in die formaat en styl soos vereis deur die Suid-Afrikaanse Vereeniging vir Diereproduksie (South African Society of Animal Science). Hoofstuk 1 is ‘n literatuurstudie bestaande uit ‘n algemene inleiding wat agtergrond oor die studie verskaf en sluit die probleemstelling in, naamlik die swak oorlewing van volstruiskuikens wat onder kunsmatige toestande grootgemaak word. Hoofstukke 2, 3, 4 en 5 bestaan uit die eerste vier studies, waartydens sekere bestuurs-aspekte, wat moontlik oorlewing van volstruiskuikens kan verbeter (nl: populasiedigtheid, tipe vloer-oppervlak, die aanwending van broeipare en die aanwending van peetouers), ondersoek is. Hoofstukke 6, 7, 8 & 9 handel oor studies wat gerig is om voeding meer aanloklik te maak vir volstruiskuikens teneinde voedselinname te stimuleer en sodoende produksie en oorlewing te verbeter (nl: verskaffing van groenvoer, geur van voer, kleur van voer en beligting van voer). Die laaste hoofstuk bestaan uit ‘n algemene gevolgtrekking en aanbevelings. Alhoewel daar gepoog is om herhaling in hoofstukke te beperk, was dit onmoontlik om herhaling van sekere gedeeltes van hoofstukke te voorkom.
- Full Text:
- Date Issued: 2008
First and second born twins: a comparative study utilizing the Graffiths mental development scales - extended revised
- Authors: Davidson, Gabrielle
- Date: 2008
- Subjects: Griffiths Scales of Mental Development , Twins -- Intelligence testing -- South Africa , Preschool children -- Intelligence testing -- South Africa , Mental development -- Testing , Psychological tests for children
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9921 , http://hdl.handle.net/10948/669 , Griffiths Scales of Mental Development , Twins -- Intelligence testing -- South Africa , Preschool children -- Intelligence testing -- South Africa , Mental development -- Testing , Psychological tests for children
- Description: Despite the concept of twins and twinning being a highly explored area of research for many years, limited research has been conducted on the comparison of first and second born twin development. The nature of twins leads people to believe that twins will present with similar characteristics, however, this study explores the possibility that due to their ordinal position they could in fact present with differing characteristics and could differ developmentally. The early holistic development of a child influences the rest of their lives. Concerning twins, the development of individuality and self-knowledge is especially important. Theorists, such as Piaget (1950), propose that child development takes place in stages and that although the order in which children proceed through these stages is the same, the pace at which this takes place can vary. The necessity of monitoring the child’s journey through these stages highlights the value of child developmental assessment. This form of assessment needs to be holistic, needs to involve a multidisciplinary team of professionals and needs to utilize assessment measures that are valid, reliable, culture-fair and standardized. The Griffiths Mental Development Scales-Extended Revised (GMDS-ER) is one such measure. This study, focusing on twin development, aimed to contribute and provide valuable information to a larger research project that is currently under way aiming to increase the applicability of the Griffiths Mental Development Scales-Extended Revised (GMDS-ER) in the South African context. The primary aim of the study, however, was to explore and compare the performance of normal first born and second born twins, aged between 2 and 8 years 4 months old, on the GMDS-ER. The purpose of the study was to generate information on the relationship between first born twins’ general development and second born twins’ general development. An exploratory, descriptive quantitative design was used. Participants were selected through a combination of non-probability purposive, convenience and snowball sampling. Data was analysed using descriptive statistics and dependent sample t-tests were employed to compare the General Quotients (GQ’s) of the first and second born twins in the sample. Results showed that no significant differences were found between the first and second born twins’ general development. Information generated from this study contributed to 1) child development research; 2) twin developmental research within a South African context; and 3) a greater group of studies on the GMDS-ER, currently underway in the United Kingdom and South Africa, aiming to contribute to the international credibility of this measure
- Full Text:
- Date Issued: 2008
- Authors: Davidson, Gabrielle
- Date: 2008
- Subjects: Griffiths Scales of Mental Development , Twins -- Intelligence testing -- South Africa , Preschool children -- Intelligence testing -- South Africa , Mental development -- Testing , Psychological tests for children
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9921 , http://hdl.handle.net/10948/669 , Griffiths Scales of Mental Development , Twins -- Intelligence testing -- South Africa , Preschool children -- Intelligence testing -- South Africa , Mental development -- Testing , Psychological tests for children
- Description: Despite the concept of twins and twinning being a highly explored area of research for many years, limited research has been conducted on the comparison of first and second born twin development. The nature of twins leads people to believe that twins will present with similar characteristics, however, this study explores the possibility that due to their ordinal position they could in fact present with differing characteristics and could differ developmentally. The early holistic development of a child influences the rest of their lives. Concerning twins, the development of individuality and self-knowledge is especially important. Theorists, such as Piaget (1950), propose that child development takes place in stages and that although the order in which children proceed through these stages is the same, the pace at which this takes place can vary. The necessity of monitoring the child’s journey through these stages highlights the value of child developmental assessment. This form of assessment needs to be holistic, needs to involve a multidisciplinary team of professionals and needs to utilize assessment measures that are valid, reliable, culture-fair and standardized. The Griffiths Mental Development Scales-Extended Revised (GMDS-ER) is one such measure. This study, focusing on twin development, aimed to contribute and provide valuable information to a larger research project that is currently under way aiming to increase the applicability of the Griffiths Mental Development Scales-Extended Revised (GMDS-ER) in the South African context. The primary aim of the study, however, was to explore and compare the performance of normal first born and second born twins, aged between 2 and 8 years 4 months old, on the GMDS-ER. The purpose of the study was to generate information on the relationship between first born twins’ general development and second born twins’ general development. An exploratory, descriptive quantitative design was used. Participants were selected through a combination of non-probability purposive, convenience and snowball sampling. Data was analysed using descriptive statistics and dependent sample t-tests were employed to compare the General Quotients (GQ’s) of the first and second born twins in the sample. Results showed that no significant differences were found between the first and second born twins’ general development. Information generated from this study contributed to 1) child development research; 2) twin developmental research within a South African context; and 3) a greater group of studies on the GMDS-ER, currently underway in the United Kingdom and South Africa, aiming to contribute to the international credibility of this measure
- Full Text:
- Date Issued: 2008
Floating sulphur biofilms structure, function and biotechnology
- Molwantwa, Jennifer Balatedi
- Authors: Molwantwa, Jennifer Balatedi
- Date: 2008
- Subjects: Biofilms Sulfur Acid mine drainage -- South Africa Mine water -- Purification -- Biological treatment Microbial ecology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3958 , http://hdl.handle.net/10962/d1004017
- Description: Mine wastewaters generated during active production operations, and decanting streams following mine closure have major environmental impacts, and volumes requiring treatment are expected to increase substantially as the South African mining industry matures. Biological treatment of mine waters has been the subject of increasing interest, where sulphate reducing bacteria are employed for the reduction of sulphate to sulphide, precipitation of metals and the production of alkalinity. However, the sulphide if not removed from the system can be oxidised back to sulphate. As a result there have been limitations especially in the provision of technological options that are sustainable over the long-term, where the total sulphur (in its different forms) can be removed from the system. These, however, are the subject of a number of constraints including, importantly, the process capability to remove reduced sulphur from the treated stream, in one of its oxidation states, and thus linearise the biological sulphur cycle. This remains a major bottleneck in the development of biological wastewater treatment technology. Floating sulphur biofilms are observed as surface layers in numerous aquatic sulphide-rich environments, and it has been suggested that they play a role in the biological cycling of sulphur. The use of sulphur biofilms for the removal of elemental sulphur was identified in this study as a possible means for addressing the technological bottleneck, especially in passive wastewater treatment systems. There is, however, little documented information in the literature on the structure of floating sulphur biofilms, the microbial species responsible for their occurrence or bio-process applications of the system. A linear flow channel reactor was developed to simulate natural conditions and enabled the study of floating sulphur biofilm under controlled laboratory conditions. It was observed that these biofilms developed through three distinct stages termed Thin, Sticky and Brittle films. A microprobe study showed the presence of a steep Redox gradient established across (260 to 380 μm) depth of the floating sulphur biofilm of ~ 0 to -200 mV (top to bottom), which correlated with pH and sulphide gradients across the system. Structural investigations embedded in an exopolymeric matrix containing clearly defined channels and pores. Sulphur crystals were found to develop within the biofilm and above a certain size these disengaged and then settled in the liquid phase below the biofilm. These features, together with the ability of the biofilm to remain suspended at the air/water interface thus provide the surface requirement, and indicate that these structures may be understood as “true” biofilms. In order to study an apparent functional differentiation within the floating sulphur biofilm system, a method was developed to expand its various components over a 13 cm length of agarose tube and across which an oxygen/sulphide gradient was established. This was done by inserting a sulphide plug in the bottom of the tube, overlaying this with the biofilm mixed and suspended in agarose and leaving the tube to open air. After allowing for growth, the different components of the microbial population occurring at various levels across the oxygen/sulphide gradient were sampled. The microbial population was found to resort in distinct functional layers. Aerobes including Acidithiobacillus and Azoarcus, Acidithiobacillus, Thiothrix, Thiovirga and Sulfurimonas were found in the upper oxidised layer. Aerobe and facultative anaerobes such as Chryseobacterium, Bacteroides and Planococcus were found in the middle and heterotrophic anaerobes such as Brevundimonas and uncultured anaerobes were found in the bottom anoxic layer. This enabled the development of a first descriptive structural/functional model accounting for the performance of floating sulphur biofilms. The potential of the floating sulphur biofilm for use as a bioprocess unit operation for sulphide removal in lignocellulose-based low-flow passive systems for acid mine drainage wastewater treatment was investigated. The linear flow channel reactor was scaled up and it was shown that the optimum sulphide removal of 74 % and sulphur recovery of 60 % could be achieved at 20 °C. In a further scale up of the linear channel reactor, the floating sulphur biofilm reactor was developed and operated. Sulphide removal and sulphur recovery of 65 and 56 % respectively was measured in the process. An understanding of the nature and function of floating sulphur biofilms and the further development of their potential application in sulphide removal in aquatic systems may provide a useful contribution to the treatment of acid mine drainage and other sulphidic wastewaters.
- Full Text:
- Date Issued: 2008
- Authors: Molwantwa, Jennifer Balatedi
- Date: 2008
- Subjects: Biofilms Sulfur Acid mine drainage -- South Africa Mine water -- Purification -- Biological treatment Microbial ecology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3958 , http://hdl.handle.net/10962/d1004017
- Description: Mine wastewaters generated during active production operations, and decanting streams following mine closure have major environmental impacts, and volumes requiring treatment are expected to increase substantially as the South African mining industry matures. Biological treatment of mine waters has been the subject of increasing interest, where sulphate reducing bacteria are employed for the reduction of sulphate to sulphide, precipitation of metals and the production of alkalinity. However, the sulphide if not removed from the system can be oxidised back to sulphate. As a result there have been limitations especially in the provision of technological options that are sustainable over the long-term, where the total sulphur (in its different forms) can be removed from the system. These, however, are the subject of a number of constraints including, importantly, the process capability to remove reduced sulphur from the treated stream, in one of its oxidation states, and thus linearise the biological sulphur cycle. This remains a major bottleneck in the development of biological wastewater treatment technology. Floating sulphur biofilms are observed as surface layers in numerous aquatic sulphide-rich environments, and it has been suggested that they play a role in the biological cycling of sulphur. The use of sulphur biofilms for the removal of elemental sulphur was identified in this study as a possible means for addressing the technological bottleneck, especially in passive wastewater treatment systems. There is, however, little documented information in the literature on the structure of floating sulphur biofilms, the microbial species responsible for their occurrence or bio-process applications of the system. A linear flow channel reactor was developed to simulate natural conditions and enabled the study of floating sulphur biofilm under controlled laboratory conditions. It was observed that these biofilms developed through three distinct stages termed Thin, Sticky and Brittle films. A microprobe study showed the presence of a steep Redox gradient established across (260 to 380 μm) depth of the floating sulphur biofilm of ~ 0 to -200 mV (top to bottom), which correlated with pH and sulphide gradients across the system. Structural investigations embedded in an exopolymeric matrix containing clearly defined channels and pores. Sulphur crystals were found to develop within the biofilm and above a certain size these disengaged and then settled in the liquid phase below the biofilm. These features, together with the ability of the biofilm to remain suspended at the air/water interface thus provide the surface requirement, and indicate that these structures may be understood as “true” biofilms. In order to study an apparent functional differentiation within the floating sulphur biofilm system, a method was developed to expand its various components over a 13 cm length of agarose tube and across which an oxygen/sulphide gradient was established. This was done by inserting a sulphide plug in the bottom of the tube, overlaying this with the biofilm mixed and suspended in agarose and leaving the tube to open air. After allowing for growth, the different components of the microbial population occurring at various levels across the oxygen/sulphide gradient were sampled. The microbial population was found to resort in distinct functional layers. Aerobes including Acidithiobacillus and Azoarcus, Acidithiobacillus, Thiothrix, Thiovirga and Sulfurimonas were found in the upper oxidised layer. Aerobe and facultative anaerobes such as Chryseobacterium, Bacteroides and Planococcus were found in the middle and heterotrophic anaerobes such as Brevundimonas and uncultured anaerobes were found in the bottom anoxic layer. This enabled the development of a first descriptive structural/functional model accounting for the performance of floating sulphur biofilms. The potential of the floating sulphur biofilm for use as a bioprocess unit operation for sulphide removal in lignocellulose-based low-flow passive systems for acid mine drainage wastewater treatment was investigated. The linear flow channel reactor was scaled up and it was shown that the optimum sulphide removal of 74 % and sulphur recovery of 60 % could be achieved at 20 °C. In a further scale up of the linear channel reactor, the floating sulphur biofilm reactor was developed and operated. Sulphide removal and sulphur recovery of 65 and 56 % respectively was measured in the process. An understanding of the nature and function of floating sulphur biofilms and the further development of their potential application in sulphide removal in aquatic systems may provide a useful contribution to the treatment of acid mine drainage and other sulphidic wastewaters.
- Full Text:
- Date Issued: 2008
Franchising a full service restaurant concept : a case study
- Authors: Thomson, Guy
- Date: 2008
- Subjects: Franchises (Retail trade) -- South Africa -- Eastern Cape , Franchises (Retail trade) -- Management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8728 , http://hdl.handle.net/10948/874 , Franchises (Retail trade) -- South Africa -- Eastern Cape , Franchises (Retail trade) -- Management
- Description: This treatise investigates the restaurant industry, entrepreneurship, franchising and restaurant franchising in order to develop a model that will enable a full service restaurant concept to be converted into a successful franchise system. Restaurants play a significant role in our lifestyle, and dining out is a favoured social activity. The industry plays an important role in the transfer of skills as many people start working in the restaurant industry before moving onto more formal careers. The restaurant industry offers many opportunities for entrepreneurial activity as a result of the relatively low barriers to entry. Entrepreneurship is the pursuit of opportunity regardless of the resources at hand and it requires a willingness to take calculated risks in order to build something of value from virtually nothing. The success of emerging economies such as China and India has proven that the only growth sectors in these economies are small and medium enterprises, which are driven by entrepreneurs. Franchising is considered to be a viable growth strategy for small business as it provides a means of raising capital and a method of expanding the business in a relatively low risk manner. There are many well established restaurant franchise brands that originated in South Africa, starting out as successful single outlets and then by means of the business format franchise model, developed into multi unit franchise systems. There are certain basic generic steps that must be followed when developing a franchise system. This was verified by the empirical study of this treatise which was conducted as a single unit case study on the Dulce Franchise Group. Finally, as a result of the analysis of the literature study and the findings of the case study, a restaurant franchise conversion model was developed.
- Full Text:
- Date Issued: 2008
- Authors: Thomson, Guy
- Date: 2008
- Subjects: Franchises (Retail trade) -- South Africa -- Eastern Cape , Franchises (Retail trade) -- Management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8728 , http://hdl.handle.net/10948/874 , Franchises (Retail trade) -- South Africa -- Eastern Cape , Franchises (Retail trade) -- Management
- Description: This treatise investigates the restaurant industry, entrepreneurship, franchising and restaurant franchising in order to develop a model that will enable a full service restaurant concept to be converted into a successful franchise system. Restaurants play a significant role in our lifestyle, and dining out is a favoured social activity. The industry plays an important role in the transfer of skills as many people start working in the restaurant industry before moving onto more formal careers. The restaurant industry offers many opportunities for entrepreneurial activity as a result of the relatively low barriers to entry. Entrepreneurship is the pursuit of opportunity regardless of the resources at hand and it requires a willingness to take calculated risks in order to build something of value from virtually nothing. The success of emerging economies such as China and India has proven that the only growth sectors in these economies are small and medium enterprises, which are driven by entrepreneurs. Franchising is considered to be a viable growth strategy for small business as it provides a means of raising capital and a method of expanding the business in a relatively low risk manner. There are many well established restaurant franchise brands that originated in South Africa, starting out as successful single outlets and then by means of the business format franchise model, developed into multi unit franchise systems. There are certain basic generic steps that must be followed when developing a franchise system. This was verified by the empirical study of this treatise which was conducted as a single unit case study on the Dulce Franchise Group. Finally, as a result of the analysis of the literature study and the findings of the case study, a restaurant franchise conversion model was developed.
- Full Text:
- Date Issued: 2008
Fungal remediation of winery and distillery wastewaters using Trametes pubescens MB 89 and the enhanced production of a high-value enzyme therein
- Authors: Strong, Peter James
- Date: 2008
- Subjects: Fungal remediation Distilleries -- Waste disposal Wine and wine making -- Waste disposal Bioremediation Laccase Enzymes -- Biotechnology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3932 , http://hdl.handle.net/10962/d1003991
- Description: In this study white-rot fungi were investigated for their efficiency at distillery wastewater remediation and the production of laccase as a valuable by-product. Distillery wastewaters are high in organic load and low in pH. The presence of phenolic compounds can lead to extremely colour-rich wastewaters and can be toxic to microorganisms. The presence of the inorganic ions may also affect biological treatment. White-rot fungi are unique among eukaryotic or prokaryotic microbes in possessing powerful oxidative enzyme systems that can degrade lignin to carbon dioxide. These ligninolytic enzymes, such as lignin peroxidase, manganese peroxidase and laccase, are capable of degrading a vast range of toxic, recalcitrant environmental pollutants and this makes the white-rot fungi strong candidates for the bioremediation of polluted soils and waters. The laccase enzyme alone has shown remediation potential in wastewaters such as beer production effluent, olive mill wastewater, alcohol distillery wastes, dye-containing wastewaters from the textile industry as well as wastewaters from the paper and pulp industry. It has been shown to be capable of remediating soils and waters polluted with chlorinated phenolic compounds, polyaromatic hydrocarbons, nitrosubstituted compounds and fungicides, herbicides and insecticides.
- Full Text:
- Date Issued: 2008
- Authors: Strong, Peter James
- Date: 2008
- Subjects: Fungal remediation Distilleries -- Waste disposal Wine and wine making -- Waste disposal Bioremediation Laccase Enzymes -- Biotechnology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3932 , http://hdl.handle.net/10962/d1003991
- Description: In this study white-rot fungi were investigated for their efficiency at distillery wastewater remediation and the production of laccase as a valuable by-product. Distillery wastewaters are high in organic load and low in pH. The presence of phenolic compounds can lead to extremely colour-rich wastewaters and can be toxic to microorganisms. The presence of the inorganic ions may also affect biological treatment. White-rot fungi are unique among eukaryotic or prokaryotic microbes in possessing powerful oxidative enzyme systems that can degrade lignin to carbon dioxide. These ligninolytic enzymes, such as lignin peroxidase, manganese peroxidase and laccase, are capable of degrading a vast range of toxic, recalcitrant environmental pollutants and this makes the white-rot fungi strong candidates for the bioremediation of polluted soils and waters. The laccase enzyme alone has shown remediation potential in wastewaters such as beer production effluent, olive mill wastewater, alcohol distillery wastes, dye-containing wastewaters from the textile industry as well as wastewaters from the paper and pulp industry. It has been shown to be capable of remediating soils and waters polluted with chlorinated phenolic compounds, polyaromatic hydrocarbons, nitrosubstituted compounds and fungicides, herbicides and insecticides.
- Full Text:
- Date Issued: 2008
Gender and development: a study of the impact of selected cooperatives in the Eastern Cape Province
- Sithole, Noluthando Victoria
- Authors: Sithole, Noluthando Victoria
- Date: 2008
- Subjects: Cooperative societies -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape , Women in development -- South Africa -- Eastern Cape , Women in cooperative societies -- South Africa -- Eastern Cape , Poverty -- South Africa -- Easttern Cape , Gender identity -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , M SW
- Identifier: vital:11752 , http://hdl.handle.net/10353/194 , Cooperative societies -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape , Women in development -- South Africa -- Eastern Cape , Women in cooperative societies -- South Africa -- Eastern Cape , Poverty -- South Africa -- Easttern Cape , Gender identity -- South Africa -- Eastern Cape
- Description: In 1994 South Africa took a new direction towards democratic governance. This led to a change of government principles and approaches in leading the country. The people became the centre of the country’s development, resulting in the adoption of people-centred development and people-driven strategies. A special focus highlighted women as in the category which had endured poverty the most in South Africa. The South African government, through its various departments, has a responsibility to improve the lives of South Africans, and the Eastern Cape Provincial Department of Social Development is one of the departments which has committed itself towards changing the lives of women in the community. As a strategy to implement community development, the Provincial Department of Social Development is funding women cooperative programmes. Women cooperatives are a relatively new endeavour to address poverty within the democratic South Africa. The study supports the notion and attempts to show the impact that women have on community development. The researcher began studying the trends and realized that the funds allocated and the funding process of community development programmes by Provincial Department of Social Development is not working towards empowering communities. A purposive sampling method was used to select two women cooperative programmes in the Chris Hani District Municipality to explore the role of women in community development in the current context of democracy and social welfare transformation in South Africa; to explore the impact of gender through women cooperatives on community development and to explore strategies for the empowerment of women through community development intervention. The design of the study is qualitative, exploratory and descriptive in nature. The study also adapted evaluation and gender analysis methods to verify the effectiveness of women programmes. The study recommends that women be empowered with skills, knowledge, resources and opportunities to enable them to be more effective in community development.
- Full Text:
- Date Issued: 2008
- Authors: Sithole, Noluthando Victoria
- Date: 2008
- Subjects: Cooperative societies -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape , Women in development -- South Africa -- Eastern Cape , Women in cooperative societies -- South Africa -- Eastern Cape , Poverty -- South Africa -- Easttern Cape , Gender identity -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , M SW
- Identifier: vital:11752 , http://hdl.handle.net/10353/194 , Cooperative societies -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape , Women in development -- South Africa -- Eastern Cape , Women in cooperative societies -- South Africa -- Eastern Cape , Poverty -- South Africa -- Easttern Cape , Gender identity -- South Africa -- Eastern Cape
- Description: In 1994 South Africa took a new direction towards democratic governance. This led to a change of government principles and approaches in leading the country. The people became the centre of the country’s development, resulting in the adoption of people-centred development and people-driven strategies. A special focus highlighted women as in the category which had endured poverty the most in South Africa. The South African government, through its various departments, has a responsibility to improve the lives of South Africans, and the Eastern Cape Provincial Department of Social Development is one of the departments which has committed itself towards changing the lives of women in the community. As a strategy to implement community development, the Provincial Department of Social Development is funding women cooperative programmes. Women cooperatives are a relatively new endeavour to address poverty within the democratic South Africa. The study supports the notion and attempts to show the impact that women have on community development. The researcher began studying the trends and realized that the funds allocated and the funding process of community development programmes by Provincial Department of Social Development is not working towards empowering communities. A purposive sampling method was used to select two women cooperative programmes in the Chris Hani District Municipality to explore the role of women in community development in the current context of democracy and social welfare transformation in South Africa; to explore the impact of gender through women cooperatives on community development and to explore strategies for the empowerment of women through community development intervention. The design of the study is qualitative, exploratory and descriptive in nature. The study also adapted evaluation and gender analysis methods to verify the effectiveness of women programmes. The study recommends that women be empowered with skills, knowledge, resources and opportunities to enable them to be more effective in community development.
- Full Text:
- Date Issued: 2008
Geographic variation in the susceptibility of false colding Moth, Thaumatotibia Leucotreta, populations to a granulovirus (CrleGV-SA)
- Authors: Opoku-Debrah, John Kwadwo
- Date: 2008
- Subjects: Cryptophlebia leucotreta , Cryptophlebia leucotreta -- Control , Pests -- Biological control , Citrus -- Diseases and pests
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10586 , http://hdl.handle.net/10948/984 , Cryptophlebia leucotreta , Cryptophlebia leucotreta -- Control , Pests -- Biological control , Citrus -- Diseases and pests
- Description: The false codling moth (FCM), Thaumatotibia (=Cryptophlebia) leucotreta (Meyrick) (Lepidoptera: Tortricidae) is a serious pest of citrus and other crops in Sub-Saharan Africa. The introduction of the Cryptophlebia leucotreta granulovirus (CrleGV-SA) Cryptogran and Cryptex (biopesticides) has proven to be very effective in the control of FCM. However, markedly lower susceptibility of some codling moth (CM), Cydia pomonella (L.) populations to Cydia pomonella granulovirus (CpGV-M), another granulovirus product used in the control of CM’s in Europe have been reported. Genetic differences between FCM populations in South Africa have also been established. It is therefore possible that differences in the susceptibility of these geographically distinct FCM populations to CrleGV-SA might also exist. To investigate this phenomenon, a benchmark for pathogenecity was established. In continuation of previous work with Cryptogran against the 1st and 5th instar FCM larvae, dose-response relationships were established for all five larval instars of FCM. In surface dose-response bioassays, the LC50 values for the 2nd, 3rd and 4th instars were calculated to be 4.516 x 104, 1.662 x 105 and 2.205 x 106 occlusion bodies (OBs)/ml, respectively. The LC90 values for the 2nd, 3rd and 4th instars were calculated to be 4.287 x 106, 9.992 x 106 and 1.661 x 108 OBs/ml, respectively. Susceptibility to CrleGV-SA was found to decline with larval stage and increase with time of exposure. The protocol was used in guiding bioassays with field collected FCM larvae. Laboratory assays conducted with Cryptogran (at 1.661 x 108 OBs/ml) against field collected FCM larvae from Addo, Kirkwood, Citrusdal and Clanwilliam as well as a standard laboratory colony, showed a significant difference in pathogenecity in only one case. This significant difference was observed between 5th instars from the Addo colony and 5th instars from the other populations. Four geographically distinct FCM colonies from Addo, Citrusdal, Marble Hall and Nelspruit were also established. Since Cryptogran and Cryptex are always targeted against 1st instar FCM larvae in the field, further comparative laboratory assays were conducted with the Addo colony and an old laboratory colony. Cryptogran was significantly more pathogenic than Cryptex against both the Addo and the old colony. However, a high level of heterogeneity was observed in responses within each population.
- Full Text:
- Date Issued: 2008
- Authors: Opoku-Debrah, John Kwadwo
- Date: 2008
- Subjects: Cryptophlebia leucotreta , Cryptophlebia leucotreta -- Control , Pests -- Biological control , Citrus -- Diseases and pests
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10586 , http://hdl.handle.net/10948/984 , Cryptophlebia leucotreta , Cryptophlebia leucotreta -- Control , Pests -- Biological control , Citrus -- Diseases and pests
- Description: The false codling moth (FCM), Thaumatotibia (=Cryptophlebia) leucotreta (Meyrick) (Lepidoptera: Tortricidae) is a serious pest of citrus and other crops in Sub-Saharan Africa. The introduction of the Cryptophlebia leucotreta granulovirus (CrleGV-SA) Cryptogran and Cryptex (biopesticides) has proven to be very effective in the control of FCM. However, markedly lower susceptibility of some codling moth (CM), Cydia pomonella (L.) populations to Cydia pomonella granulovirus (CpGV-M), another granulovirus product used in the control of CM’s in Europe have been reported. Genetic differences between FCM populations in South Africa have also been established. It is therefore possible that differences in the susceptibility of these geographically distinct FCM populations to CrleGV-SA might also exist. To investigate this phenomenon, a benchmark for pathogenecity was established. In continuation of previous work with Cryptogran against the 1st and 5th instar FCM larvae, dose-response relationships were established for all five larval instars of FCM. In surface dose-response bioassays, the LC50 values for the 2nd, 3rd and 4th instars were calculated to be 4.516 x 104, 1.662 x 105 and 2.205 x 106 occlusion bodies (OBs)/ml, respectively. The LC90 values for the 2nd, 3rd and 4th instars were calculated to be 4.287 x 106, 9.992 x 106 and 1.661 x 108 OBs/ml, respectively. Susceptibility to CrleGV-SA was found to decline with larval stage and increase with time of exposure. The protocol was used in guiding bioassays with field collected FCM larvae. Laboratory assays conducted with Cryptogran (at 1.661 x 108 OBs/ml) against field collected FCM larvae from Addo, Kirkwood, Citrusdal and Clanwilliam as well as a standard laboratory colony, showed a significant difference in pathogenecity in only one case. This significant difference was observed between 5th instars from the Addo colony and 5th instars from the other populations. Four geographically distinct FCM colonies from Addo, Citrusdal, Marble Hall and Nelspruit were also established. Since Cryptogran and Cryptex are always targeted against 1st instar FCM larvae in the field, further comparative laboratory assays were conducted with the Addo colony and an old laboratory colony. Cryptogran was significantly more pathogenic than Cryptex against both the Addo and the old colony. However, a high level of heterogeneity was observed in responses within each population.
- Full Text:
- Date Issued: 2008
Growth of the South African abalone (Haliotis Midae) on three diets, under commercial conditions
- Authors: Makhande, Emmanuel Denis
- Date: 2008
- Subjects: Haliotis midae -- South Africa , Abalone culture -- South Africa , Abalones -- Nutrition -- South Africa , Abalones -- Physiology -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10706 , http://hdl.handle.net/10948/755 , Haliotis midae -- South Africa , Abalone culture -- South Africa , Abalones -- Nutrition -- South Africa , Abalones -- Physiology -- South Africa
- Description: Haliotis midae is the cornerstone of the South African abalone fishery. For more than a decade, the wild abalone stock of South Africa has suffered decline due to over-exploitation and illegal activities such as poaching. Prior to 1970, no regulations were in place concerning the annual landings. As a result the fishery was exploited as if it were an infinite resource. It is this initial uncontrolled harvesting (regardless of age) and poaching that has driven the abalone resource decline. Due to the slow growth rate exhibited by abalone as a species, natural replenishment of wild stock following exploitation and poaching was far below the rate of exploitation of this resource. Studies on the growth of abalone have mainly been conducted under laboratory conditions. The purpose of this study was to measure the growth of abalone, fed different diets, under commercial culture conditions. Three food types were used namely; commercial pellets, seaweed (Ulva spp.) and dried kelp bars (Ecklonia maxima). Four diets were obtained from the three food types namely; combination of commercial pellets and seaweed (Diet A), commercial pellets only (Diet B), seaweed only (Diet C) and dried kelp bars only (Diet D). The food types used in this study represent both artificial (Commercial pellets) and natural feeds (seaweed and kelp) used in commercial abalone culture. The growth of two cohorts (40-50 mm and 50-60 mm) was followed over a 426 day period, with data for the first 183 days being used for statistical analysis to determine performance of a given diet. The best growth rates were found in abalone fed Diet A (40-50 mm: 2.64 mm.month-1; 50-60 mm 2.78: mm.month-1) and B (40-50 mm: 2.20 mm.month-1; 50-60 mm: 2.35: mm.month-1). These (Diets A and B) gave higher growth rates when compared to Diets C and D (natural diets), whose growth rates ranged between 0.50 mm.month-1 and 1.71 mm.month-1 for both cohorts. Also observed in this study was that, the mixture of formulated diet and seaweed gave better growth than formulated diet given exclusively.
- Full Text:
- Date Issued: 2008
- Authors: Makhande, Emmanuel Denis
- Date: 2008
- Subjects: Haliotis midae -- South Africa , Abalone culture -- South Africa , Abalones -- Nutrition -- South Africa , Abalones -- Physiology -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10706 , http://hdl.handle.net/10948/755 , Haliotis midae -- South Africa , Abalone culture -- South Africa , Abalones -- Nutrition -- South Africa , Abalones -- Physiology -- South Africa
- Description: Haliotis midae is the cornerstone of the South African abalone fishery. For more than a decade, the wild abalone stock of South Africa has suffered decline due to over-exploitation and illegal activities such as poaching. Prior to 1970, no regulations were in place concerning the annual landings. As a result the fishery was exploited as if it were an infinite resource. It is this initial uncontrolled harvesting (regardless of age) and poaching that has driven the abalone resource decline. Due to the slow growth rate exhibited by abalone as a species, natural replenishment of wild stock following exploitation and poaching was far below the rate of exploitation of this resource. Studies on the growth of abalone have mainly been conducted under laboratory conditions. The purpose of this study was to measure the growth of abalone, fed different diets, under commercial culture conditions. Three food types were used namely; commercial pellets, seaweed (Ulva spp.) and dried kelp bars (Ecklonia maxima). Four diets were obtained from the three food types namely; combination of commercial pellets and seaweed (Diet A), commercial pellets only (Diet B), seaweed only (Diet C) and dried kelp bars only (Diet D). The food types used in this study represent both artificial (Commercial pellets) and natural feeds (seaweed and kelp) used in commercial abalone culture. The growth of two cohorts (40-50 mm and 50-60 mm) was followed over a 426 day period, with data for the first 183 days being used for statistical analysis to determine performance of a given diet. The best growth rates were found in abalone fed Diet A (40-50 mm: 2.64 mm.month-1; 50-60 mm 2.78: mm.month-1) and B (40-50 mm: 2.20 mm.month-1; 50-60 mm: 2.35: mm.month-1). These (Diets A and B) gave higher growth rates when compared to Diets C and D (natural diets), whose growth rates ranged between 0.50 mm.month-1 and 1.71 mm.month-1 for both cohorts. Also observed in this study was that, the mixture of formulated diet and seaweed gave better growth than formulated diet given exclusively.
- Full Text:
- Date Issued: 2008
Harvesting strategies of fuelwood and kraalwood users at Machibi : identifying the driving factors and feedbacks
- Authors: Scheepers, Kelly
- Date: 2008
- Subjects: Fuelwood -- South Africa -- Eastern Cape Forest ecology -- South Africa -- Eastern Cape Natural resources -- South Africa -- Eastern Cape Natural resources -- Management -- South Africa -- Eastern Cape Conservation of natural resources -- South Africa -- Eastern Cape Landscape protection -- Economic aspects -- South Africa -- Eastern Cape Fuelwood consumption -- South Africa -- Eastern Cape Fuelwood consumption -- Economic aspects -- South Africa -- Eastern Cape Forests and forestry -- South Africa -- Eastern Cape Fuelwood conservation -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4765 , http://hdl.handle.net/10962/d1007167
- Description: Forest and woodland ecosystems provide a variety of natural resources such as fuelwood, brushwood and kraal posts to local communities, as well as possess important cultural and spiritual value. However, many forests and woodlands worldwide have been unsustainably used and managed. Thus, under pressure from the international conservation community to recognise the importance of people's relationships with their surrounding natural environment, particularly for the natural resources it can provide, and given a move away from the management of forests and woodlands for sustained yields, and according to simple cause and effect models, in favour of systems approaches, South Africa has developed some of the most progressive natural resource management policies in the world. Nevertheless, for these policies to be sensitive to local contexts, there remains a need for a better understanding of how local people in different contexts, determine forest and woodland ecosystems to be of use to them, and what 'usefulness' means to different groups of resources users. This is a case study, which examines the role of fuelwood, brushwood and kraal posts in the rural livelihoods of the people of Machibi village, located in the Eastern Cape province of South Africa, through people's preferences for particular landscapes and species, accessed for these purposes, and the trade-offs people make between resource availability and resource accessibility. Key objectives of the study are to 1) determine the preferred landscapes and species for fuelwood, brushwood and kraal posts at Machibi, 2) determine the landscapes and species actually used for fuelwood, brushwood and kraal posts, and 3) with the help of a conceptual model, and using iterative modelling as a tool, determine the factors that influence people's harvesting strategies in terms of the costs and benefits associated with the different landscape and species options. On the basis of this knowledge, the study provides some guiding principles for the better use and management of these landscapes and species for fuelwood, brushwood and kraal posts. An innovative research approach and methodology that integrates social and ecological systems, works across disciplines, and draws on different types of knowledge is used to develop and test a conceptual model of the harvesting strategies of fuelwood and kraalwood users at Machibi. Participatory methods such as workshops, participatory resource mapping, ranking exercises and trend-lines were used to tap into local knowledge while plotless vegetation sampling and GIS maps were used to capture the scientific information. Results showed that people did not always use the landscapes and species they preferred. However, the local people did behave in a rational manner by weighing up the returns from harvesting and accessibility costs associated with the respective options available to them, before selecting the option(s) associated with the greatest net benefits. At the landscape level, people made trade-offs between the returns from harvesting and the accessibility costs of using particular landscapes in addition to costs associated with the physical work of harvesting fuelwood, brushwood or kraal posts from these landscapes. At the species level, people made trade-offs between the returns from harvesting and the accessibility costs of harvesting particular species for fuelwood, brushwood and kraal posts, or the costs of commercial alternatives. Costbenefit factors that influenced people's resource use patterns also differed across landscapes and species for fuelwood, brushwood and kraal posts, respectively. Consequently, a range of diverse and flexible management options and strategies is recommended for the wise use and management of these landscapes and species, focused on short, medium and long term goals. These strategies examine the use of cost - benefit incentives to influence people’s landscape and species use patterns.
- Full Text:
- Date Issued: 2008
- Authors: Scheepers, Kelly
- Date: 2008
- Subjects: Fuelwood -- South Africa -- Eastern Cape Forest ecology -- South Africa -- Eastern Cape Natural resources -- South Africa -- Eastern Cape Natural resources -- Management -- South Africa -- Eastern Cape Conservation of natural resources -- South Africa -- Eastern Cape Landscape protection -- Economic aspects -- South Africa -- Eastern Cape Fuelwood consumption -- South Africa -- Eastern Cape Fuelwood consumption -- Economic aspects -- South Africa -- Eastern Cape Forests and forestry -- South Africa -- Eastern Cape Fuelwood conservation -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4765 , http://hdl.handle.net/10962/d1007167
- Description: Forest and woodland ecosystems provide a variety of natural resources such as fuelwood, brushwood and kraal posts to local communities, as well as possess important cultural and spiritual value. However, many forests and woodlands worldwide have been unsustainably used and managed. Thus, under pressure from the international conservation community to recognise the importance of people's relationships with their surrounding natural environment, particularly for the natural resources it can provide, and given a move away from the management of forests and woodlands for sustained yields, and according to simple cause and effect models, in favour of systems approaches, South Africa has developed some of the most progressive natural resource management policies in the world. Nevertheless, for these policies to be sensitive to local contexts, there remains a need for a better understanding of how local people in different contexts, determine forest and woodland ecosystems to be of use to them, and what 'usefulness' means to different groups of resources users. This is a case study, which examines the role of fuelwood, brushwood and kraal posts in the rural livelihoods of the people of Machibi village, located in the Eastern Cape province of South Africa, through people's preferences for particular landscapes and species, accessed for these purposes, and the trade-offs people make between resource availability and resource accessibility. Key objectives of the study are to 1) determine the preferred landscapes and species for fuelwood, brushwood and kraal posts at Machibi, 2) determine the landscapes and species actually used for fuelwood, brushwood and kraal posts, and 3) with the help of a conceptual model, and using iterative modelling as a tool, determine the factors that influence people's harvesting strategies in terms of the costs and benefits associated with the different landscape and species options. On the basis of this knowledge, the study provides some guiding principles for the better use and management of these landscapes and species for fuelwood, brushwood and kraal posts. An innovative research approach and methodology that integrates social and ecological systems, works across disciplines, and draws on different types of knowledge is used to develop and test a conceptual model of the harvesting strategies of fuelwood and kraalwood users at Machibi. Participatory methods such as workshops, participatory resource mapping, ranking exercises and trend-lines were used to tap into local knowledge while plotless vegetation sampling and GIS maps were used to capture the scientific information. Results showed that people did not always use the landscapes and species they preferred. However, the local people did behave in a rational manner by weighing up the returns from harvesting and accessibility costs associated with the respective options available to them, before selecting the option(s) associated with the greatest net benefits. At the landscape level, people made trade-offs between the returns from harvesting and the accessibility costs of using particular landscapes in addition to costs associated with the physical work of harvesting fuelwood, brushwood or kraal posts from these landscapes. At the species level, people made trade-offs between the returns from harvesting and the accessibility costs of harvesting particular species for fuelwood, brushwood and kraal posts, or the costs of commercial alternatives. Costbenefit factors that influenced people's resource use patterns also differed across landscapes and species for fuelwood, brushwood and kraal posts, respectively. Consequently, a range of diverse and flexible management options and strategies is recommended for the wise use and management of these landscapes and species, focused on short, medium and long term goals. These strategies examine the use of cost - benefit incentives to influence people’s landscape and species use patterns.
- Full Text:
- Date Issued: 2008
Have the continuous improvement (CI) efforts at Absa Bank's Horizon Medium Business Banking Unit, in the Gauteng West Region successfully addressed the key concepts of continuous improvement as set out by Trollip, 2008?
- Authors: Ndlovu, Sinqobile Khobotho
- Date: 2008
- Subjects: Banks and banking -- Customer services -- South Africa , Organizational effectiveness
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8721 , http://hdl.handle.net/10948/904 , Banks and banking -- Customer services -- South Africa , Organizational effectiveness
- Description: Success in today’s highly competitive financial sector requires an organization to have a sustainable competitive advantage that would distinguish it from the rest. Products offered by financial organizations are naturally the same and the quality of service plays a critical role in terms of creating the much needed competitive advantage. This calls for the implementation of quality initiatives like Continuous improvement (CI). This paper investigates the extent to which CI efforts at the Horizon business unit of Absa corporate and business banking have successfully addressed the key concepts of CI set out by Trollip (2008). A literature survey was undertaken into the elements and benefits of CI. Questionnaires were sent to all employees of the business unit for their views on CI and the impact, they believe it has on the unit’s endeavors to deliver faster, defect free, innovative products/services, whilst achieving tougher goals. In conclusion the research paper led to recommendations to improve the CI efforts at the Horizon business unit. The research also confirmed the importance of the commitment of all employees is essential for the success of CI efforts in improving the quality of service offered by an organization.
- Full Text:
- Date Issued: 2008
- Authors: Ndlovu, Sinqobile Khobotho
- Date: 2008
- Subjects: Banks and banking -- Customer services -- South Africa , Organizational effectiveness
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8721 , http://hdl.handle.net/10948/904 , Banks and banking -- Customer services -- South Africa , Organizational effectiveness
- Description: Success in today’s highly competitive financial sector requires an organization to have a sustainable competitive advantage that would distinguish it from the rest. Products offered by financial organizations are naturally the same and the quality of service plays a critical role in terms of creating the much needed competitive advantage. This calls for the implementation of quality initiatives like Continuous improvement (CI). This paper investigates the extent to which CI efforts at the Horizon business unit of Absa corporate and business banking have successfully addressed the key concepts of CI set out by Trollip (2008). A literature survey was undertaken into the elements and benefits of CI. Questionnaires were sent to all employees of the business unit for their views on CI and the impact, they believe it has on the unit’s endeavors to deliver faster, defect free, innovative products/services, whilst achieving tougher goals. In conclusion the research paper led to recommendations to improve the CI efforts at the Horizon business unit. The research also confirmed the importance of the commitment of all employees is essential for the success of CI efforts in improving the quality of service offered by an organization.
- Full Text:
- Date Issued: 2008
Her master's: the experiences of mature women in postgraduate study
- Authors: Hood, Mary Ann
- Date: 2008
- Subjects: Women graduate students -- South Africa , Women scholars -- South Africa , Women -- Education (Graduate)
- Language: English
- Type: Thesis , Masters , M Ed
- Identifier: vital:16159 , http://hdl.handle.net/10353/211 , Women graduate students -- South Africa , Women scholars -- South Africa , Women -- Education (Graduate)
- Description: This study explored the experiences of mature women undertaking Master’s degrees at a Historically Disadvantaged Institution of Higher Learning in South Africa. Attaining a Master’s degree is a significant milestone in education and the process may take from one to three, or more, years. The study aims to describe aspects of the women’s experiences of their research journeys and the goal of the study is to present descriptions of these experiences. The methodology is qualitative and uses a critical feminist approach, appropriate to exploring the research questions. A critical feminist stance holds that women experience the world differently to men given the patriarchal structure of society. Emphasis is placed on the primacy of the co-researcher’s perceptions of their experiences. A single method research design was followed using semi-structured interviews. The analysis resulted in the emergence of a number of central themes. Together these reflect the experiences of the co-researchers, although they did not automatically share all the experiences. The findings show that postgraduate study, in the form of a Master’s degree, was found to be transformative, meaningful and worthwhile, although not without difficulties; mainly the demands required of multiple roles within home, community, work, and the university. This study contributes towards the larger body of research within education, in particular in the understanding the experiences of mature women within the field of postgraduate study.
- Full Text:
- Date Issued: 2008
- Authors: Hood, Mary Ann
- Date: 2008
- Subjects: Women graduate students -- South Africa , Women scholars -- South Africa , Women -- Education (Graduate)
- Language: English
- Type: Thesis , Masters , M Ed
- Identifier: vital:16159 , http://hdl.handle.net/10353/211 , Women graduate students -- South Africa , Women scholars -- South Africa , Women -- Education (Graduate)
- Description: This study explored the experiences of mature women undertaking Master’s degrees at a Historically Disadvantaged Institution of Higher Learning in South Africa. Attaining a Master’s degree is a significant milestone in education and the process may take from one to three, or more, years. The study aims to describe aspects of the women’s experiences of their research journeys and the goal of the study is to present descriptions of these experiences. The methodology is qualitative and uses a critical feminist approach, appropriate to exploring the research questions. A critical feminist stance holds that women experience the world differently to men given the patriarchal structure of society. Emphasis is placed on the primacy of the co-researcher’s perceptions of their experiences. A single method research design was followed using semi-structured interviews. The analysis resulted in the emergence of a number of central themes. Together these reflect the experiences of the co-researchers, although they did not automatically share all the experiences. The findings show that postgraduate study, in the form of a Master’s degree, was found to be transformative, meaningful and worthwhile, although not without difficulties; mainly the demands required of multiple roles within home, community, work, and the university. This study contributes towards the larger body of research within education, in particular in the understanding the experiences of mature women within the field of postgraduate study.
- Full Text:
- Date Issued: 2008
Home range dynamics of spotted grunter, pomadasys commersonnii, in a South African intermittently open estuary
- Authors: O'Connell, Bronwyn Anne
- Date: 2008
- Subjects: Grunts (Fishes) -- South Africa -- Eastern Cape , Pomadasys -- South Africa -- Eastern Cape , Estuaries -- South Africa -- Eastern Cape , Estuarine fishes -- South Africa -- Eastern Cape , Estuarine fishes -- Habitat -- South Africa -- Eastern Cape , Fishery management -- South Africa -- Eastern Cape , Fishes -- Home range , Fishes -- Home range -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5286 , http://hdl.handle.net/10962/d1005130 , Grunts (Fishes) -- South Africa -- Eastern Cape , Pomadasys -- South Africa -- Eastern Cape , Estuaries -- South Africa -- Eastern Cape , Estuarine fishes -- South Africa -- Eastern Cape , Estuarine fishes -- Habitat -- South Africa -- Eastern Cape , Fishery management -- South Africa -- Eastern Cape , Fishes -- Home range , Fishes -- Home range -- South Africa -- Eastern Cape
- Description: The spotted grunter (Pomadasys commersonnii) is an important, estuarine-dependent, fishery species in southern Africa. Since estuaries are essential habitats in the life history of this species, the quantification of area use patterns and movements is important for fisheries management. In this study, acoustic telemetry was used to investigate movements, use of habitat and home range dynamics of spotted grunter in the small intermittently open East Kleinemonde Estuary on the Eastern Cape coast of South Africa. Nine spotted grunter (range: 326-489mm TL) were surgically equipped with uniquely coded acoustic transmitters. Positional fixes were obtained by manual tracking tagged individuals on six days and six nights during five tracking sessions from March to November 2004. In addition, five stationary data-logging receivers, moored at specific locations from the mouth to the top of the estuary provided additional long-term monitoring. Kernel home ranges (95% UD) varied in size (26 296-165 321m²) but were all located in a common high use area situated between 300-1 300m from the estuary mouth, which coincided with the highest abundance of prey items. There was no significant variation in home range size [C² (N = 9, df = 4) = 4.18; p = 0.38] between the temporally segregated tracking sessions (over nine months). The persistence of these home range estimates were confirmed by the long-term data-logging receivers. There was no significant diel variation in home range size [F(4, 64) = 0.05, p = 0.99] or core area size [F(4, 64) = 1.40, p = 0.25]. Fish length showed negative, although not significant, relationships between home range size (p = 0.225); number of home range areas (p = 0.065); core area size (p = 0.512) and home range length (p = 0.320). Use of habitat and home range dynamics of spotted grunter in the East Kleinemonde Estuary were consistent over the nine month study period, and they appeared to be influenced more by biotic than abiotic factors. However, when the mouth opened at the end of the study, most tagged fish vacated their home ranges and emigrated to sea.
- Full Text:
- Date Issued: 2008
- Authors: O'Connell, Bronwyn Anne
- Date: 2008
- Subjects: Grunts (Fishes) -- South Africa -- Eastern Cape , Pomadasys -- South Africa -- Eastern Cape , Estuaries -- South Africa -- Eastern Cape , Estuarine fishes -- South Africa -- Eastern Cape , Estuarine fishes -- Habitat -- South Africa -- Eastern Cape , Fishery management -- South Africa -- Eastern Cape , Fishes -- Home range , Fishes -- Home range -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5286 , http://hdl.handle.net/10962/d1005130 , Grunts (Fishes) -- South Africa -- Eastern Cape , Pomadasys -- South Africa -- Eastern Cape , Estuaries -- South Africa -- Eastern Cape , Estuarine fishes -- South Africa -- Eastern Cape , Estuarine fishes -- Habitat -- South Africa -- Eastern Cape , Fishery management -- South Africa -- Eastern Cape , Fishes -- Home range , Fishes -- Home range -- South Africa -- Eastern Cape
- Description: The spotted grunter (Pomadasys commersonnii) is an important, estuarine-dependent, fishery species in southern Africa. Since estuaries are essential habitats in the life history of this species, the quantification of area use patterns and movements is important for fisheries management. In this study, acoustic telemetry was used to investigate movements, use of habitat and home range dynamics of spotted grunter in the small intermittently open East Kleinemonde Estuary on the Eastern Cape coast of South Africa. Nine spotted grunter (range: 326-489mm TL) were surgically equipped with uniquely coded acoustic transmitters. Positional fixes were obtained by manual tracking tagged individuals on six days and six nights during five tracking sessions from March to November 2004. In addition, five stationary data-logging receivers, moored at specific locations from the mouth to the top of the estuary provided additional long-term monitoring. Kernel home ranges (95% UD) varied in size (26 296-165 321m²) but were all located in a common high use area situated between 300-1 300m from the estuary mouth, which coincided with the highest abundance of prey items. There was no significant variation in home range size [C² (N = 9, df = 4) = 4.18; p = 0.38] between the temporally segregated tracking sessions (over nine months). The persistence of these home range estimates were confirmed by the long-term data-logging receivers. There was no significant diel variation in home range size [F(4, 64) = 0.05, p = 0.99] or core area size [F(4, 64) = 1.40, p = 0.25]. Fish length showed negative, although not significant, relationships between home range size (p = 0.225); number of home range areas (p = 0.065); core area size (p = 0.512) and home range length (p = 0.320). Use of habitat and home range dynamics of spotted grunter in the East Kleinemonde Estuary were consistent over the nine month study period, and they appeared to be influenced more by biotic than abiotic factors. However, when the mouth opened at the end of the study, most tagged fish vacated their home ranges and emigrated to sea.
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- Date Issued: 2008