Environmental Education and Educational Quality and Relevance-Opening the debate
- Authors: Lotz-Sisitka, Heila
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182668 , vital:43852 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122756"
- Description: This edition of the Southern African Journal of Environmental Education (SAJEE) tackles a critical issue being debated across the world today, namely the question of educational quality and relevance. In 2005 the UNESCO Education for All Global Monitoring Report entitled Education for All: The Quality Imperative (UNESCO, 2004) was published. This global monitoring report drew attention to issues of educational quality, and raised the problem that physical access to education does not necessarily lead to epistemological access to knowledge or to relevant education being offered to learners. In the foreword to the 430-page assessment of educational quality issues, Koïchiro Matsuura, Director General of UNESCO, stated that ‘although much debate surrounds attempts to define educational quality, solid common ground exists … Quality must be seen in light of how societies define the purpose of education’ (UNESCO, 2004: Foreword). He went on to explain that there seem to be two mutually agreed upon purposes for education in the world today: cognitive development of learners, and creative and emotional growth of learners to help them acquire values and attitudes for responsible citizenship. He also pointed out that ‘quality must pass the test of equity’ (UNESCO, 2004: Foreword), emphasising the importance of equity of opportunity to access and participate in education and learning. Relevant to the field of environmental education, is the inclusion of educational quality as a major thrust of the United Nations Decade of Education for Sustainable Development (UNDESD) (UNESCO, 2004).
- Full Text:
- Date Issued: 2008
- Authors: Lotz-Sisitka, Heila
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182668 , vital:43852 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122756"
- Description: This edition of the Southern African Journal of Environmental Education (SAJEE) tackles a critical issue being debated across the world today, namely the question of educational quality and relevance. In 2005 the UNESCO Education for All Global Monitoring Report entitled Education for All: The Quality Imperative (UNESCO, 2004) was published. This global monitoring report drew attention to issues of educational quality, and raised the problem that physical access to education does not necessarily lead to epistemological access to knowledge or to relevant education being offered to learners. In the foreword to the 430-page assessment of educational quality issues, Koïchiro Matsuura, Director General of UNESCO, stated that ‘although much debate surrounds attempts to define educational quality, solid common ground exists … Quality must be seen in light of how societies define the purpose of education’ (UNESCO, 2004: Foreword). He went on to explain that there seem to be two mutually agreed upon purposes for education in the world today: cognitive development of learners, and creative and emotional growth of learners to help them acquire values and attitudes for responsible citizenship. He also pointed out that ‘quality must pass the test of equity’ (UNESCO, 2004: Foreword), emphasising the importance of equity of opportunity to access and participate in education and learning. Relevant to the field of environmental education, is the inclusion of educational quality as a major thrust of the United Nations Decade of Education for Sustainable Development (UNDESD) (UNESCO, 2004).
- Full Text:
- Date Issued: 2008
Environmental health work methods and procedures for the surveillance and control of avian influenza in the Eastern Cape Province, South Africa
- Authors: Elie, Sammy Abraham
- Date: 2008
- Subjects: Avian influenza -- Eastern Cape -- South Africa -- Prevention , Environmental health -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9834 , http://hdl.handle.net/10948/947 , http://hdl.handle.net/10948/d1009648 , Avian influenza -- Eastern Cape -- South Africa -- Prevention , Environmental health -- South Africa -- Eastern Cape
- Description: Avian influenza is an infectious disease of birds caused by the Type A strain of the influenza virus. The disease, which was first identified in Italy more than 100 years ago, occurs worldwide (World Health Organization, 2006a). The current outbreak of the highly pathogenic avian influenza A (H5N1), which began in Southeast Asia in mid-2003, is the largest and most severe on record. Never before in the recorded history of this disease have so many countries been simultaneously affected. Since the last pandemic in 1968-1969, the risk of an influenza pandemic has not been considered greater than at the present time. The importance of intervention strategies had become increasingly evident throughout the world. The World Health Organization provides a generic outline for preparedness plans to assist countries in their preparations to respond to a possible avian influenza pandemic. These guidelines may be modified as the epidemiology of avian influenza evolves. The South African National Department of Health has developed national guidelines in the form of an avian influenza preparedness plan. These draft guidelines do not provide detailed Environmental Health work methods and - procedures for the effective surveillance and control of the disease. The general purpose of this study is to develop a standardised set of Environmental Health work methods and - procedures, which will contribute to the effective surveillance and control of avian influenza in the Eastern Cape province – South Africa. Within the context of the purpose of this study, a qualitative, explorative, descriptive, inductive and deductive research design will be used. The methods of data collection will be documentary research, telephonic as well as in-depth personal interviews. In this study, documentary research will be the primary method of data collection. With a qualitative approach, the researcher will be the human instrument for data analysis. The process of qualitative data analysis will be based on data reduction and interpretation; and will be conducted as an activity simultaneously with data collection, data interpretation and narrative reporting writing.
- Full Text:
- Date Issued: 2008
- Authors: Elie, Sammy Abraham
- Date: 2008
- Subjects: Avian influenza -- Eastern Cape -- South Africa -- Prevention , Environmental health -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9834 , http://hdl.handle.net/10948/947 , http://hdl.handle.net/10948/d1009648 , Avian influenza -- Eastern Cape -- South Africa -- Prevention , Environmental health -- South Africa -- Eastern Cape
- Description: Avian influenza is an infectious disease of birds caused by the Type A strain of the influenza virus. The disease, which was first identified in Italy more than 100 years ago, occurs worldwide (World Health Organization, 2006a). The current outbreak of the highly pathogenic avian influenza A (H5N1), which began in Southeast Asia in mid-2003, is the largest and most severe on record. Never before in the recorded history of this disease have so many countries been simultaneously affected. Since the last pandemic in 1968-1969, the risk of an influenza pandemic has not been considered greater than at the present time. The importance of intervention strategies had become increasingly evident throughout the world. The World Health Organization provides a generic outline for preparedness plans to assist countries in their preparations to respond to a possible avian influenza pandemic. These guidelines may be modified as the epidemiology of avian influenza evolves. The South African National Department of Health has developed national guidelines in the form of an avian influenza preparedness plan. These draft guidelines do not provide detailed Environmental Health work methods and - procedures for the effective surveillance and control of the disease. The general purpose of this study is to develop a standardised set of Environmental Health work methods and - procedures, which will contribute to the effective surveillance and control of avian influenza in the Eastern Cape province – South Africa. Within the context of the purpose of this study, a qualitative, explorative, descriptive, inductive and deductive research design will be used. The methods of data collection will be documentary research, telephonic as well as in-depth personal interviews. In this study, documentary research will be the primary method of data collection. With a qualitative approach, the researcher will be the human instrument for data analysis. The process of qualitative data analysis will be based on data reduction and interpretation; and will be conducted as an activity simultaneously with data collection, data interpretation and narrative reporting writing.
- Full Text:
- Date Issued: 2008
Equiprime near-rings
- Authors: Mogae, Kabelo
- Date: 2008
- Subjects: Near-rings
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10505 , http://hdl.handle.net/10948/1028 , Near-rings
- Description: Prior to 1990, the only well known ideal-hereditary Kurosh-Amitsur radicals in the variety of zero-symmetric near-rings were the Jacobson type radicals Iv(N) , where ∨∈{2,3} and the Brown-McCoy radical. In 1990, Booth, Groenewald and Veldsman introduced the concept of an equiprime near-ring which leads to an ideal-hereditary Kurosh-Amitsur radical in N∘. The concept of an equiprime near-ring generalizes the concept of a prime ring to near-rings. Although the search for more ideal-hereditary radicals of near-rings was apparently the original motivation for the introduction of equiprime near-rings, it became clear that these near-rings are interesting in their own right. It is our aim in this treatise to give an exposition of the many interesting properties of equiprime near-rings. We begin with a brief reminder of near-ring rudiments; giving basic definitions and elementary results which are necessary for understanding and development of subsequent chapters. With the basics out of the way, our main task begins with a consideration of equiprime, strongly and completely equiprime left ideals. It is noted that any zero-symmetric near-ring can be embedded in an equiprime near-ring. Moreover, the class of equiprime near-rings is shown to be hereditary. Open questions arising out of the study of equiprime near-rings are highlighted along the way. In Chapter 3 we consider well known examples of near-rings and determine when such near-rings are equiprime. This provides more insight into the nature of equiprime near-rings and is a fertile ground for the birth of examples and counterexamples which may be used to close or solve some open question within the literature. We also prove some results which generalize some results of Booth and Hall [10] and Veldsman [29]. These results have not been previously presented elsewhere to the best of our knowledge. vii In Chapter 4, the equiprime near-rings are shown to yield an ideal-hereditary radical in N∘. It is shown that a special radical theory can be built on the equiprime nearrings in much the same way prime rings are used in ring theory to define special radical classes of rings.
- Full Text:
- Date Issued: 2008
- Authors: Mogae, Kabelo
- Date: 2008
- Subjects: Near-rings
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10505 , http://hdl.handle.net/10948/1028 , Near-rings
- Description: Prior to 1990, the only well known ideal-hereditary Kurosh-Amitsur radicals in the variety of zero-symmetric near-rings were the Jacobson type radicals Iv(N) , where ∨∈{2,3} and the Brown-McCoy radical. In 1990, Booth, Groenewald and Veldsman introduced the concept of an equiprime near-ring which leads to an ideal-hereditary Kurosh-Amitsur radical in N∘. The concept of an equiprime near-ring generalizes the concept of a prime ring to near-rings. Although the search for more ideal-hereditary radicals of near-rings was apparently the original motivation for the introduction of equiprime near-rings, it became clear that these near-rings are interesting in their own right. It is our aim in this treatise to give an exposition of the many interesting properties of equiprime near-rings. We begin with a brief reminder of near-ring rudiments; giving basic definitions and elementary results which are necessary for understanding and development of subsequent chapters. With the basics out of the way, our main task begins with a consideration of equiprime, strongly and completely equiprime left ideals. It is noted that any zero-symmetric near-ring can be embedded in an equiprime near-ring. Moreover, the class of equiprime near-rings is shown to be hereditary. Open questions arising out of the study of equiprime near-rings are highlighted along the way. In Chapter 3 we consider well known examples of near-rings and determine when such near-rings are equiprime. This provides more insight into the nature of equiprime near-rings and is a fertile ground for the birth of examples and counterexamples which may be used to close or solve some open question within the literature. We also prove some results which generalize some results of Booth and Hall [10] and Veldsman [29]. These results have not been previously presented elsewhere to the best of our knowledge. vii In Chapter 4, the equiprime near-rings are shown to yield an ideal-hereditary radical in N∘. It is shown that a special radical theory can be built on the equiprime nearrings in much the same way prime rings are used in ring theory to define special radical classes of rings.
- Full Text:
- Date Issued: 2008
Establishing a basis for ecosystem management in the western Indian Ocean
- Vousden, David, Scott, Lucy E P, Sauer, Warwick H H, Bornman, T G, Ngoile, M, Stapley, J, Lutjeharms, Johan R E
- Authors: Vousden, David , Scott, Lucy E P , Sauer, Warwick H H , Bornman, T G , Ngoile, M , Stapley, J , Lutjeharms, Johan R E
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6774 , http://hdl.handle.net/10962/d1008081
- Description: An ambitious multinational programme, with generous funding for an initial five years, aims to provide understanding of marine resources for the benefit of impoverished island and coastal populations in a much-neglected ocean region.
- Full Text:
- Date Issued: 2008
- Authors: Vousden, David , Scott, Lucy E P , Sauer, Warwick H H , Bornman, T G , Ngoile, M , Stapley, J , Lutjeharms, Johan R E
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6774 , http://hdl.handle.net/10962/d1008081
- Description: An ambitious multinational programme, with generous funding for an initial five years, aims to provide understanding of marine resources for the benefit of impoverished island and coastal populations in a much-neglected ocean region.
- Full Text:
- Date Issued: 2008
Estimating the age of immature Chrysomya albiceps (Diptera: Calliphoridae), correcting for temperature and geographical latitude
- Richards, Cameron S, Paterson, Iain D, Villet, Martin H
- Authors: Richards, Cameron S , Paterson, Iain D , Villet, Martin H
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442129 , vital:73961 , https://doi.org/10.1007/s00414-007-0201-7
- Description: Developmental curves for Chrysomya albiceps (Wiedemann) (Diptera: Calliphoridae) were established at 13 different constant temperatures using developmental landmarks and length as measures of age. The thermal summation constants (K) and developmental zeros (D 0) were calculated for five developmental landmarks using the method described by Ikemoto and Takai (Environ Entomol 29:671–682, 2000). Comparison with the K and D 0 values of our findings to those of three previously published studies of C. albiceps suggests that K is directly proportional to geographic latitude, and D 0 is inversely proportional to both K and geographic latitude. Body size and developmental landmarks have a complex relationship because of trade-offs between mortality risk and female fecundity (as measured by body size) at non-optimal temperatures. This relationship can be summarized using superimposed isomorphen and isomegalen diagrams, which can then be used to make forensic estimates of postmortem intervals from larval body lengths. Finally, we recommend that future studies providing data for precise forensic estimates of postmortem intervals should use a relative temporal precision of about 10% of the total duration being measured. For many blowflies, this translates into a sampling interval of approximately every 2 h before hatching, 3 h before first ecdysis and 6 h before second ecdysis.
- Full Text:
- Date Issued: 2008
- Authors: Richards, Cameron S , Paterson, Iain D , Villet, Martin H
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442129 , vital:73961 , https://doi.org/10.1007/s00414-007-0201-7
- Description: Developmental curves for Chrysomya albiceps (Wiedemann) (Diptera: Calliphoridae) were established at 13 different constant temperatures using developmental landmarks and length as measures of age. The thermal summation constants (K) and developmental zeros (D 0) were calculated for five developmental landmarks using the method described by Ikemoto and Takai (Environ Entomol 29:671–682, 2000). Comparison with the K and D 0 values of our findings to those of three previously published studies of C. albiceps suggests that K is directly proportional to geographic latitude, and D 0 is inversely proportional to both K and geographic latitude. Body size and developmental landmarks have a complex relationship because of trade-offs between mortality risk and female fecundity (as measured by body size) at non-optimal temperatures. This relationship can be summarized using superimposed isomorphen and isomegalen diagrams, which can then be used to make forensic estimates of postmortem intervals from larval body lengths. Finally, we recommend that future studies providing data for precise forensic estimates of postmortem intervals should use a relative temporal precision of about 10% of the total duration being measured. For many blowflies, this translates into a sampling interval of approximately every 2 h before hatching, 3 h before first ecdysis and 6 h before second ecdysis.
- Full Text:
- Date Issued: 2008
Evaluating and improving morpho-syntactic classification over multiple corpora using pre-trained, off-the-shelf, parts-of-speech tagging tools reviewed article
- Glass, Kevin R, Bangay, Shaun D
- Authors: Glass, Kevin R , Bangay, Shaun D
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433427 , vital:72969 , https://hdl.handle.net/10520/EJC28053
- Description: This paper evaluates six commonly available parts-of-speech tagging tools over corpora other than those upon which they were originally trained. In particular this investigation measures the performance of the selected tools over varying styles and genres of text without retraining, under the assumption that domain specific training data is not always available. An investigation is performed to determine whether improved results can be achieved by combining the set of tagging tools into ensembles that use voting schemes to determine the best tag for each word. It is found that while accuracy drops due to non-domain specific training, and tag-mapping between corpora, accuracy remains very high, with the support vector machine-based tagger, and the decision tree-based tagger performing best over different corpora. It is also found that an ensemble containing a support vector machine-based tagger, a probabilistic tagger, a decision-tree based tagger and a rule-based tagger produces the largest increase in accuracy and the largest reduction in error across different corpora, using the Precision-Recall voting scheme.
- Full Text:
- Date Issued: 2008
- Authors: Glass, Kevin R , Bangay, Shaun D
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433427 , vital:72969 , https://hdl.handle.net/10520/EJC28053
- Description: This paper evaluates six commonly available parts-of-speech tagging tools over corpora other than those upon which they were originally trained. In particular this investigation measures the performance of the selected tools over varying styles and genres of text without retraining, under the assumption that domain specific training data is not always available. An investigation is performed to determine whether improved results can be achieved by combining the set of tagging tools into ensembles that use voting schemes to determine the best tag for each word. It is found that while accuracy drops due to non-domain specific training, and tag-mapping between corpora, accuracy remains very high, with the support vector machine-based tagger, and the decision tree-based tagger performing best over different corpora. It is also found that an ensemble containing a support vector machine-based tagger, a probabilistic tagger, a decision-tree based tagger and a rule-based tagger produces the largest increase in accuracy and the largest reduction in error across different corpora, using the Precision-Recall voting scheme.
- Full Text:
- Date Issued: 2008
Evaluating service quality at George Municipality : a complaints management systems approach
- Authors: Alcock, Sandra
- Date: 2008
- Subjects: Consumer complaints -- South Africa -- George , Consumer satisfaction -- South Africa -- George , Customer services -- Management , Local government -- South Africa -- George
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8717 , http://hdl.handle.net/10948/917 , Consumer complaints -- South Africa -- George , Consumer satisfaction -- South Africa -- George , Customer services -- Management , Local government -- South Africa -- George
- Description: The search for service and product quality has come to the forefront of business studies as the most important consumer trend of the past two decades. Studies conducted indicate that the 1990s saw a dramatic change in customer expectations concerning service quality and standards with a corresponding increase in the number of complaints from disgruntled customers. In response to this, many organisations have established customer care and complaints management services to respond to the need of customers. A substantial amount of literature exists on the subject of complaints management and its role in service quality, however, the focus has been on organisations in the private sector. The research undertaken in this paper aimed to investigate the role of complaints management systems (CMS) to evaluate service quality. The focus of this research was on local government with special attention on George Municipality. A literature review was done to establish the importance of service quality for local government as well as to investigate the link between an effective complaints management system and improvement in service quality. Furthermore, it was necessary to investigate the characteristics, design and implementation of an effective complaints management system. A questionnaire was developed in order to obtain primary data from a selected sample group. The data obtained from the questionnaire was statistically analysed and interpreted. The core findings from the analysed questionnaire indicated the following: service quality is relevant in local government; there is no clear method to measure service quality; no formal and structured complaints management system exist, and the implementation of an effective complaints management system will both improve service delivery and provide benefits to all involved. iv This study recommends that: service quality standards and measurement be of strategic importance to local government; customers should be consulted and involved when determining the service quality standards and measurement, and an organised and structured complaints management system that seeks to address all complaints in order to improve the level of service quality to customers be developed. Finally, the success of the CMS will depend on management’s commitment to change on a continuous basis as well as the degree to which management proactively resolves customer complaint through the involvement of the customer.
- Full Text:
- Date Issued: 2008
- Authors: Alcock, Sandra
- Date: 2008
- Subjects: Consumer complaints -- South Africa -- George , Consumer satisfaction -- South Africa -- George , Customer services -- Management , Local government -- South Africa -- George
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8717 , http://hdl.handle.net/10948/917 , Consumer complaints -- South Africa -- George , Consumer satisfaction -- South Africa -- George , Customer services -- Management , Local government -- South Africa -- George
- Description: The search for service and product quality has come to the forefront of business studies as the most important consumer trend of the past two decades. Studies conducted indicate that the 1990s saw a dramatic change in customer expectations concerning service quality and standards with a corresponding increase in the number of complaints from disgruntled customers. In response to this, many organisations have established customer care and complaints management services to respond to the need of customers. A substantial amount of literature exists on the subject of complaints management and its role in service quality, however, the focus has been on organisations in the private sector. The research undertaken in this paper aimed to investigate the role of complaints management systems (CMS) to evaluate service quality. The focus of this research was on local government with special attention on George Municipality. A literature review was done to establish the importance of service quality for local government as well as to investigate the link between an effective complaints management system and improvement in service quality. Furthermore, it was necessary to investigate the characteristics, design and implementation of an effective complaints management system. A questionnaire was developed in order to obtain primary data from a selected sample group. The data obtained from the questionnaire was statistically analysed and interpreted. The core findings from the analysed questionnaire indicated the following: service quality is relevant in local government; there is no clear method to measure service quality; no formal and structured complaints management system exist, and the implementation of an effective complaints management system will both improve service delivery and provide benefits to all involved. iv This study recommends that: service quality standards and measurement be of strategic importance to local government; customers should be consulted and involved when determining the service quality standards and measurement, and an organised and structured complaints management system that seeks to address all complaints in order to improve the level of service quality to customers be developed. Finally, the success of the CMS will depend on management’s commitment to change on a continuous basis as well as the degree to which management proactively resolves customer complaint through the involvement of the customer.
- Full Text:
- Date Issued: 2008
Evaluation of the effective micro-organisms (EM) on soil chemical properties and yield of selected vegetables in the Eastern Cape, South Africa
- Authors: Ncube, Lindani
- Date: 2008
- Subjects: Greenhouse management -- South Africa -- Eastern Cape , Butternut -- South Africa -- Eastern Cape , Microorganisms -- South Africa -- Eastern Cape , Sustainable agriculture -- South Africa -- Eastern Cape , Organic farming -- South Africa -- Eastern Cape , Tomatoes -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Horticultural Science)
- Identifier: vital:11886 , http://hdl.handle.net/10353/86
- Description: Effective microorganisms (EM), a commercial concoction of microbes that includes yeasts, fungi, bacteria and actinomycetes, have been found to be effective in enhancing crop growth by a number of scholars. It is registered in South Africa, but it had not been thoroughly investigated. The present study investigated the effects of EM on growth, yield and quality of tomato (Lycopersicon esculentum Mill), butternut (Curcurbita moschata) and Swiss chard (Beta vulgaris), along with selected soil properties. In field-grown tomato it was observed that the application of EM caused a significant increase in the number of fruits at seven weeks after transplanting. However, plants treated with EM alone, or EM in combination with other amendments, subsequently produced lower yields owing to an outbreak of early and late blights which affected them the most severely. Combined applications of EM with organic amendments improved plant N content and increased soil N content above initial levels. The application of compost resulted in soil N and P concentrations higher than those of the control presumably due to nutrients being slowly released from the compost material. In a follow up greenhouse trial EM application had a negative effect on tomato leaf dry matter yield, number of leaves, number of trusses, fruit yield and number of fruits. The negative effects of EM were ascribed to N immobilization by the EM that could have resulted in reduced N availability to plants. The lower number of fruits associated with EM application resulted in improved average fruit weight of tomatoes grown in the greenhouse, possibly as a result of more assimilates being partitioned to the few fruits EM application also had a negative effect on field grown butternut as reflected by lower total yield, lower marketable yield and lower first grade yield. The results were attributed to immobilization of N induced by application of EM, and to the inability of EM to control pumpkin fly that attacked very young fruit, resulting in their failure to develop or resulting in the down grading of mature fruits. The application of EM alone had a positive but non significant effect on the yields of both the first and second harvests of Swiss chard. However, when applied with compost or goat manure, a non significant negative effect on yield was observed. When applied with inorganic fertilizer, EM had no effect on yield but tended to increase the uptake of nitrogen by Swiss chard. Though goat manure had a narrower C: N ratio than compost, it did not result in greater EM effectiveness as had been hoped. However, goat manure had a more positive effect on soil properties than compost. It increased the N, P, and K contents of the soil and resulted in a narrower C: N ratio of the soil compared to compost. Generally, the results of the four trials conducted with three different crops indicated that EM had inconsistent effects on crop performance.
- Full Text:
- Date Issued: 2008
- Authors: Ncube, Lindani
- Date: 2008
- Subjects: Greenhouse management -- South Africa -- Eastern Cape , Butternut -- South Africa -- Eastern Cape , Microorganisms -- South Africa -- Eastern Cape , Sustainable agriculture -- South Africa -- Eastern Cape , Organic farming -- South Africa -- Eastern Cape , Tomatoes -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Horticultural Science)
- Identifier: vital:11886 , http://hdl.handle.net/10353/86
- Description: Effective microorganisms (EM), a commercial concoction of microbes that includes yeasts, fungi, bacteria and actinomycetes, have been found to be effective in enhancing crop growth by a number of scholars. It is registered in South Africa, but it had not been thoroughly investigated. The present study investigated the effects of EM on growth, yield and quality of tomato (Lycopersicon esculentum Mill), butternut (Curcurbita moschata) and Swiss chard (Beta vulgaris), along with selected soil properties. In field-grown tomato it was observed that the application of EM caused a significant increase in the number of fruits at seven weeks after transplanting. However, plants treated with EM alone, or EM in combination with other amendments, subsequently produced lower yields owing to an outbreak of early and late blights which affected them the most severely. Combined applications of EM with organic amendments improved plant N content and increased soil N content above initial levels. The application of compost resulted in soil N and P concentrations higher than those of the control presumably due to nutrients being slowly released from the compost material. In a follow up greenhouse trial EM application had a negative effect on tomato leaf dry matter yield, number of leaves, number of trusses, fruit yield and number of fruits. The negative effects of EM were ascribed to N immobilization by the EM that could have resulted in reduced N availability to plants. The lower number of fruits associated with EM application resulted in improved average fruit weight of tomatoes grown in the greenhouse, possibly as a result of more assimilates being partitioned to the few fruits EM application also had a negative effect on field grown butternut as reflected by lower total yield, lower marketable yield and lower first grade yield. The results were attributed to immobilization of N induced by application of EM, and to the inability of EM to control pumpkin fly that attacked very young fruit, resulting in their failure to develop or resulting in the down grading of mature fruits. The application of EM alone had a positive but non significant effect on the yields of both the first and second harvests of Swiss chard. However, when applied with compost or goat manure, a non significant negative effect on yield was observed. When applied with inorganic fertilizer, EM had no effect on yield but tended to increase the uptake of nitrogen by Swiss chard. Though goat manure had a narrower C: N ratio than compost, it did not result in greater EM effectiveness as had been hoped. However, goat manure had a more positive effect on soil properties than compost. It increased the N, P, and K contents of the soil and resulted in a narrower C: N ratio of the soil compared to compost. Generally, the results of the four trials conducted with three different crops indicated that EM had inconsistent effects on crop performance.
- Full Text:
- Date Issued: 2008
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 affecting accuracy and precision of thermal summation models of insect development used to estimate post-mortem intervals
- Richards, Cameron S, Villet, Martin H
- Authors: Richards, Cameron S , Villet, Martin H
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442142 , vital:73962 , https://doi.org/10.1007/s00414-008-0243-5
- Description: This paper investigates the effects that different summary statistics (minimum, median, mean, or maximum), temporal sampling resolutions (duration between sampling events), and sample sizes (number of individuals sampled per sampling event) had on the accuracy and precision of the regression coefficients of a typical thermal summation model used to calculate minimum post-mortem interval (PMI). No significant differences were found in the values of the developmental constants calculated from different summary statistics of the duration of development. Sample size was found to affect the precision of measurement of the duration of development but had little overall influence on thermal summation constant (K) and developmental threshold (D 0) calculations (and therefore, subsequent PMI estimates), but temporal sampling resolution had a direct influence on the accuracy of K and D 0 calculations. These data suggest that when numbers of experimental maggots are limited, it is more important to sample more frequently using smaller sample sizes than to sample less frequently with large sample sizes. Furthermore, we suggest that the median is the most representative summary measure of the duration of development and should be used preferentially.
- Full Text:
- Date Issued: 2008
- Authors: Richards, Cameron S , Villet, Martin H
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442142 , vital:73962 , https://doi.org/10.1007/s00414-008-0243-5
- Description: This paper investigates the effects that different summary statistics (minimum, median, mean, or maximum), temporal sampling resolutions (duration between sampling events), and sample sizes (number of individuals sampled per sampling event) had on the accuracy and precision of the regression coefficients of a typical thermal summation model used to calculate minimum post-mortem interval (PMI). No significant differences were found in the values of the developmental constants calculated from different summary statistics of the duration of development. Sample size was found to affect the precision of measurement of the duration of development but had little overall influence on thermal summation constant (K) and developmental threshold (D 0) calculations (and therefore, subsequent PMI estimates), but temporal sampling resolution had a direct influence on the accuracy of K and D 0 calculations. These data suggest that when numbers of experimental maggots are limited, it is more important to sample more frequently using smaller sample sizes than to sample less frequently with large sample sizes. Furthermore, we suggest that the median is the most representative summary measure of the duration of development and should be used preferentially.
- 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