"I felt that I deserved it" : an Investigation into HIV-related PTSD, traumatic life events, and the personal experiences of living with HIV : a mixed-method study
- Authors: Boulind, Melissa Jane
- Date: 2014
- Subjects: Post-traumatic stress disorder -- Psychological aspects -- Research -- South Africa -- Kwazulu HIV infections -- Psychological aspects -- Research -- South Africa -- Kwazulu HIV-positive persons -- South Africa -- Kwazulu -- Interviews Psychic trauma -- Research Stress (Psychology) -- Research
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3211 , http://hdl.handle.net/10962/d1012172
- Description: There appears to be a growing body of literature focusing on PTSD and HIV-related PTSD (the diagnosis of HIV being the significant traumatic event) amongst HIV-positive samples, but only a few African studies that attempt to estimate the prevalence of PTSD amongst HIV-positive people, and even fewer that attempt to estimate the prevalence of HIV-related PTSD. The systemic review presented in this study is currently fully inclusive and is the most up-to-date available. Estimates of the prevalence of PTSD and HIV-related PTSD in South Africa range from 0.7 to 54.1% and, 4.2 to 40% respectively. The current cross-sectional study made use of a mixed-method approach to investigate traumatic life events, PTSD and HIV-related PTSD within a primary health-care centre in KwaZulu-Natal. The quantitative sample consisted of 159 adults (18-50 years) who were compliant on ARV medication. Using the CIDI-PTSD module, the adapted CIDI-PTSD module for HIV, and IES-R, findings indicated that 62% had reported some kind of traumatic event in their lifetime, with 29.6% of participants meeting the criteria for lifetime PTSD, and 40.9% meeting the criteria for lifetime HIV-related PTSD. Altogether, 57.9% of individuals met the criteria for some form of PTSD (either regular PTSD or HIV-related PTSD), and 12.6% met the criteria for both PTSD and HIV-related PTSD. Of the different categories of traumatic events, interpersonal violence has the highest rate of PTSD, followed by a diagnosis of and living with HIV, and then disaster. Furthermore, the IES-R was compared for its usefulness as a screening measure for PTSD against both the CIDI, but results suggest that it is an inferior screening measure to the PDS. The qualitative study consisted of six participants who were examined using IPA methodology informed by the Ehlers and Clark (2000) Model of trauma. Their experiences revealed experiences of stigma, a number of negative appraisals, negative emotions and coping behaviours. Some of the latter might serve as compensatory mechanisms to avoid negative judgements. Hypervigilance seems to be a feature of ARV-compliance that might confer added vulnerability to PTSD and other anxiety disorders.
- Full Text:
- Date Issued: 2014
- Authors: Boulind, Melissa Jane
- Date: 2014
- Subjects: Post-traumatic stress disorder -- Psychological aspects -- Research -- South Africa -- Kwazulu HIV infections -- Psychological aspects -- Research -- South Africa -- Kwazulu HIV-positive persons -- South Africa -- Kwazulu -- Interviews Psychic trauma -- Research Stress (Psychology) -- Research
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3211 , http://hdl.handle.net/10962/d1012172
- Description: There appears to be a growing body of literature focusing on PTSD and HIV-related PTSD (the diagnosis of HIV being the significant traumatic event) amongst HIV-positive samples, but only a few African studies that attempt to estimate the prevalence of PTSD amongst HIV-positive people, and even fewer that attempt to estimate the prevalence of HIV-related PTSD. The systemic review presented in this study is currently fully inclusive and is the most up-to-date available. Estimates of the prevalence of PTSD and HIV-related PTSD in South Africa range from 0.7 to 54.1% and, 4.2 to 40% respectively. The current cross-sectional study made use of a mixed-method approach to investigate traumatic life events, PTSD and HIV-related PTSD within a primary health-care centre in KwaZulu-Natal. The quantitative sample consisted of 159 adults (18-50 years) who were compliant on ARV medication. Using the CIDI-PTSD module, the adapted CIDI-PTSD module for HIV, and IES-R, findings indicated that 62% had reported some kind of traumatic event in their lifetime, with 29.6% of participants meeting the criteria for lifetime PTSD, and 40.9% meeting the criteria for lifetime HIV-related PTSD. Altogether, 57.9% of individuals met the criteria for some form of PTSD (either regular PTSD or HIV-related PTSD), and 12.6% met the criteria for both PTSD and HIV-related PTSD. Of the different categories of traumatic events, interpersonal violence has the highest rate of PTSD, followed by a diagnosis of and living with HIV, and then disaster. Furthermore, the IES-R was compared for its usefulness as a screening measure for PTSD against both the CIDI, but results suggest that it is an inferior screening measure to the PDS. The qualitative study consisted of six participants who were examined using IPA methodology informed by the Ehlers and Clark (2000) Model of trauma. Their experiences revealed experiences of stigma, a number of negative appraisals, negative emotions and coping behaviours. Some of the latter might serve as compensatory mechanisms to avoid negative judgements. Hypervigilance seems to be a feature of ARV-compliance that might confer added vulnerability to PTSD and other anxiety disorders.
- Full Text:
- Date Issued: 2014
(Re-)inventing our selves/ourselves : identity and community in contemporary South African short fiction cycles.
- Authors: Marais, Susan Jacqueline
- Date: 2014
- Subjects: South African fiction (English) -- History and criticism , Matlou, Joël -- Criticism and interpretation , Magona, Sindiwe -- Criticism and interpretation , Vladislavić, Ivan, 1957- -- Criticism and interpretation , Wicomb, Zoë -- Criticism and interpretation
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2326 , http://hdl.handle.net/10962/d1016357
- Description: In this study I focus on a number of collections of short fiction by the South African writers Joël Matlou, Sindiwe Magona, Zoë Wicomb and Ivan Vladislavić, all of which evince certain of the characteristics of short story cycles or sequences. In other words, they display what Forrest L. Ingram describes as “a double tendency of asserting the individuality of [their] components on the one hand and of highlighting, on the other, the bonds of unity which make the many into a single whole”. The cycle form, thus defined, is characterised by a paradoxical yet productive and frequently unresolved tension between “the individuality of each of the stories and the necessities of the larger unit”, between “the one and the many”, and between cohesion and fragmentation. It is this “dynamic structure of connection and disconnection” which singularly equips the genre to represent the interrelationship of singular and collective identities, or the “coherent multiplicity of community”. Ingram, for example, asserts that “Numerous and varied connective strands draw the co-protagonists of any story cycle into a single community. … However this community may be achieved, it usually can be said to constitute the central character of a cycle”. Not unsurprisingly, then, in its dominant manifestations over much of the twentieth century the short story cycle demonstrated a marked inclination towards regionalism and the depiction of localised enclaves, and this tendency towards “place-based short story cycles” in which topographical unity is a conspicuous feature was as pronounced in South Africa as elsewhere. However, the specific collections which are my concern here increasingly employ innovative and self-reflexive narrative strategies that unsettle generic expectations and interrogate the notions of regionalism and community conventionally associated with the short story cycle. My investigation seeks to explain this shift in emphasis, and its particular significance within the South African context.
- Full Text:
- Date Issued: 2014
- Authors: Marais, Susan Jacqueline
- Date: 2014
- Subjects: South African fiction (English) -- History and criticism , Matlou, Joël -- Criticism and interpretation , Magona, Sindiwe -- Criticism and interpretation , Vladislavić, Ivan, 1957- -- Criticism and interpretation , Wicomb, Zoë -- Criticism and interpretation
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2326 , http://hdl.handle.net/10962/d1016357
- Description: In this study I focus on a number of collections of short fiction by the South African writers Joël Matlou, Sindiwe Magona, Zoë Wicomb and Ivan Vladislavić, all of which evince certain of the characteristics of short story cycles or sequences. In other words, they display what Forrest L. Ingram describes as “a double tendency of asserting the individuality of [their] components on the one hand and of highlighting, on the other, the bonds of unity which make the many into a single whole”. The cycle form, thus defined, is characterised by a paradoxical yet productive and frequently unresolved tension between “the individuality of each of the stories and the necessities of the larger unit”, between “the one and the many”, and between cohesion and fragmentation. It is this “dynamic structure of connection and disconnection” which singularly equips the genre to represent the interrelationship of singular and collective identities, or the “coherent multiplicity of community”. Ingram, for example, asserts that “Numerous and varied connective strands draw the co-protagonists of any story cycle into a single community. … However this community may be achieved, it usually can be said to constitute the central character of a cycle”. Not unsurprisingly, then, in its dominant manifestations over much of the twentieth century the short story cycle demonstrated a marked inclination towards regionalism and the depiction of localised enclaves, and this tendency towards “place-based short story cycles” in which topographical unity is a conspicuous feature was as pronounced in South Africa as elsewhere. However, the specific collections which are my concern here increasingly employ innovative and self-reflexive narrative strategies that unsettle generic expectations and interrogate the notions of regionalism and community conventionally associated with the short story cycle. My investigation seeks to explain this shift in emphasis, and its particular significance within the South African context.
- Full Text:
- Date Issued: 2014
A best practice guideline for patient-centred care in public hospitals in Nelson Mandela Bay
- Authors: Jardien-Baboo, Sihaam
- Date: 2014
- Subjects: Patient-centered health care -- South Africa -- Nelson Mandela Bay Municipality , Evidence-based medicine -- South Africa -- Nelson Mandela Bay Municipality , Public health nurses -- South Africa -- Nelson Mandela Bay Municipality , Public hospitals -- South Africa -- Nelson Mandela Bay Municipality
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:10063 , http://hdl.handle.net/10948/d1020370
- Description: In South Africa, the quality of health care is directly related to the concept of patient-centred care and the enactment of the Batho Pele Principles and the Patients’ Rights Charter. The quality of health care delivery has dropped drastically, and reports in the media indicate that public hospitals in the Eastern Cape Province are on the brink of collapse, with thousands of patients being treated in condemned hospitals. Receiving and rendering health care in the face of such challenges, the question arose: “Are patients receiving patient-centred care in public hospitals?” The answer to this rhetorical inquiry appeared to be obvious, but this research study explored and described professional nurses’ perceptions of patient-centred care in public hospitals and their understanding of evidence-based practice and best practice guidelines. The proposed study followed a qualitative, exploratory, descriptive and contextual design. The research population included professional nurses who are employed in public hospitals in Nelson Mandela Bay, and consisted of nurse managers and nurses who work in the wards. The research study consisted of three phases. In Phase 1, semi-structured interviews and focus groups were conducted with nurse managers and professional nurses working in the wards in order to collect data about their perceptions of patient-centred care and their understanding of evidence-based practice and best practice guidelines. The interviews were transcribed and Tesch’s eight steps of data analysis were followed to create meaning from the data collected. Themes were identified and grouped together to form new categories. The researcher ensured the validity of the study by conforming to Lincoln and Guba’s model of trustworthiness, which consists of the following four constructs: credibility, transferability, dependability and confirmability. An independent coder assisted with the coding process. In Phase 2, an integrative literature review was conducted in order to identify previous guidelines regarding best practice for patient-centred care. Relevant guidelines were selected, critically appraised, data was extracted and synthesised for the development of a best practice guideline for patient-centred care. An independent appraiser critically appraised the guidelines, thereby ensuring trustworthiness. In Phase 3, the data in Phase 1 and Phase 2 were integrated to formulate a draft best practice guideline for patient-centred care. The guideline was submitted to an expert panel for review and was modified according to the recommendations of the panel, whereby the best practice guideline for patient-centred care in public hospitals in Nelson Mandela Bay was finalized.
- Full Text:
- Date Issued: 2014
- Authors: Jardien-Baboo, Sihaam
- Date: 2014
- Subjects: Patient-centered health care -- South Africa -- Nelson Mandela Bay Municipality , Evidence-based medicine -- South Africa -- Nelson Mandela Bay Municipality , Public health nurses -- South Africa -- Nelson Mandela Bay Municipality , Public hospitals -- South Africa -- Nelson Mandela Bay Municipality
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:10063 , http://hdl.handle.net/10948/d1020370
- Description: In South Africa, the quality of health care is directly related to the concept of patient-centred care and the enactment of the Batho Pele Principles and the Patients’ Rights Charter. The quality of health care delivery has dropped drastically, and reports in the media indicate that public hospitals in the Eastern Cape Province are on the brink of collapse, with thousands of patients being treated in condemned hospitals. Receiving and rendering health care in the face of such challenges, the question arose: “Are patients receiving patient-centred care in public hospitals?” The answer to this rhetorical inquiry appeared to be obvious, but this research study explored and described professional nurses’ perceptions of patient-centred care in public hospitals and their understanding of evidence-based practice and best practice guidelines. The proposed study followed a qualitative, exploratory, descriptive and contextual design. The research population included professional nurses who are employed in public hospitals in Nelson Mandela Bay, and consisted of nurse managers and nurses who work in the wards. The research study consisted of three phases. In Phase 1, semi-structured interviews and focus groups were conducted with nurse managers and professional nurses working in the wards in order to collect data about their perceptions of patient-centred care and their understanding of evidence-based practice and best practice guidelines. The interviews were transcribed and Tesch’s eight steps of data analysis were followed to create meaning from the data collected. Themes were identified and grouped together to form new categories. The researcher ensured the validity of the study by conforming to Lincoln and Guba’s model of trustworthiness, which consists of the following four constructs: credibility, transferability, dependability and confirmability. An independent coder assisted with the coding process. In Phase 2, an integrative literature review was conducted in order to identify previous guidelines regarding best practice for patient-centred care. Relevant guidelines were selected, critically appraised, data was extracted and synthesised for the development of a best practice guideline for patient-centred care. An independent appraiser critically appraised the guidelines, thereby ensuring trustworthiness. In Phase 3, the data in Phase 1 and Phase 2 were integrated to formulate a draft best practice guideline for patient-centred care. The guideline was submitted to an expert panel for review and was modified according to the recommendations of the panel, whereby the best practice guideline for patient-centred care in public hospitals in Nelson Mandela Bay was finalized.
- Full Text:
- Date Issued: 2014
A case study of a pre-service mathematics education course to grow and develop proficient teaching in mathematics in the intermediate phase
- Authors: Lee, Amanda Jane
- Date: 2014
- Subjects: Mathematics -- Study and teaching -- South Africa , Mathematics teachers -- Training of -- South Africa , Mathematics -- Study and teaching (Elementary) -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2004 , http://hdl.handle.net/10962/d1015664
- Description: This research study investigated the ways in which a mathematics module, informed by an enactivist philosophy, enabled pre-service teachers to unpack the reality of their teaching practice in terms of proficient teaching. Given the generally poor mathematics results in South Africa it is not enough for teachers to be merely proficient in Mathematics. They also need to be in a position to explain important mathematical concepts to children in a manner that will encourage and develop an understanding of the basic mathematical concepts. It was my intention with this study to determine whether a mathematics education module, that embraced the underlying themes of enactivism as part of its teaching pedagogy, could have the potential to develop and increase the skills of pre-service teachers’ teaching for proficiency in Mathematics. The mathematics module was underpinned by five themes of enactivism namely: autonomy, embodiment, emergence, sense-making and experience and was designed to supplement the pre-service teachers’ basic skills in Mathematics in the Intermediate Phase. This mathematics module was offered to fourth year pre-service teachers completing a B.Ed. in the Foundation Phase at a private institute specialising in the training of teachers. The theoretical framework was informed by enactivism and how the themes of enactivism could be used as a vehicle to develop teaching proficiency. The study was qualitative in nature and situated within an interpretivist paradigm. The specific perspectives of interpretivism that were used were hermeneutics, phenomenology and reflexivity. The research design was a case study that contained elements of action research and encompassed three phases of data collection. The first phase focused on the pre-service teachers’ approach to teaching Mathematics and what this brought forth in terms of the reality of their teaching practice and the problems they encountered. The second phase undertook to determine what growth and development of teaching proficiency in Mathematics had emerged over the research period. The final phase was undertaken after the pre-service teachers had graduated and were employed as full time teachers in the Intermediate Phase. The analytical framework and lens through which the data was analysed was that of Kilpatrick, Swafford and Findell’s (2001) strands of mathematical proficiency. The argument that I present is that the themes of enactivism did contribute to the growth of the pre-service teachers’ teaching for mathematical proficiency. The themes of embodiment and experience were major contributions in revealing that this was a reality for the pre-service teachers from a practical perspective and was what they would be able to take away with them. However the theme of emergence stood out as the principle that generated the most awareness and growth and which, in turn, affected the participants’ autonomy.
- Full Text:
- Date Issued: 2014
- Authors: Lee, Amanda Jane
- Date: 2014
- Subjects: Mathematics -- Study and teaching -- South Africa , Mathematics teachers -- Training of -- South Africa , Mathematics -- Study and teaching (Elementary) -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2004 , http://hdl.handle.net/10962/d1015664
- Description: This research study investigated the ways in which a mathematics module, informed by an enactivist philosophy, enabled pre-service teachers to unpack the reality of their teaching practice in terms of proficient teaching. Given the generally poor mathematics results in South Africa it is not enough for teachers to be merely proficient in Mathematics. They also need to be in a position to explain important mathematical concepts to children in a manner that will encourage and develop an understanding of the basic mathematical concepts. It was my intention with this study to determine whether a mathematics education module, that embraced the underlying themes of enactivism as part of its teaching pedagogy, could have the potential to develop and increase the skills of pre-service teachers’ teaching for proficiency in Mathematics. The mathematics module was underpinned by five themes of enactivism namely: autonomy, embodiment, emergence, sense-making and experience and was designed to supplement the pre-service teachers’ basic skills in Mathematics in the Intermediate Phase. This mathematics module was offered to fourth year pre-service teachers completing a B.Ed. in the Foundation Phase at a private institute specialising in the training of teachers. The theoretical framework was informed by enactivism and how the themes of enactivism could be used as a vehicle to develop teaching proficiency. The study was qualitative in nature and situated within an interpretivist paradigm. The specific perspectives of interpretivism that were used were hermeneutics, phenomenology and reflexivity. The research design was a case study that contained elements of action research and encompassed three phases of data collection. The first phase focused on the pre-service teachers’ approach to teaching Mathematics and what this brought forth in terms of the reality of their teaching practice and the problems they encountered. The second phase undertook to determine what growth and development of teaching proficiency in Mathematics had emerged over the research period. The final phase was undertaken after the pre-service teachers had graduated and were employed as full time teachers in the Intermediate Phase. The analytical framework and lens through which the data was analysed was that of Kilpatrick, Swafford and Findell’s (2001) strands of mathematical proficiency. The argument that I present is that the themes of enactivism did contribute to the growth of the pre-service teachers’ teaching for mathematical proficiency. The themes of embodiment and experience were major contributions in revealing that this was a reality for the pre-service teachers from a practical perspective and was what they would be able to take away with them. However the theme of emergence stood out as the principle that generated the most awareness and growth and which, in turn, affected the participants’ autonomy.
- Full Text:
- Date Issued: 2014
A context-aware model to improve usability of information presented on mobile devices
- Authors: Ntawanga, Felix Fred
- Date: 2014
- Subjects: Context-aware computing , Online information services
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10495 , http://hdl.handle.net/10948/d1020768
- Description: Online information access on mobile devices is increasing as a result of the growth in the use of Internet-enabled handheld (or pocket-size) devices. The combined influence of recent enabling technologies such as Web 2.0, mobile app stores and improved wireless networks have driven the increase in online applications that allow users to access various types of information on mobile devices regardless of time and location. Examples of such applications (usually shortened to app) include: social media, such as FacebookTM App and TwitterTM App, banking applications such as (Standard Bank South Africa)TM Mobile Banking App and First National Bank (FNB) BankingTM App, and news application such as news 24TM App and BBCTM News App. Online businesses involved in buying, selling and business transaction processing activities via the Internet have exploited the opportunity to extend electronic commerce (e-commerce) initiatives into mobile commerce (m-commerce). Online businesses that interact with end user customers implement business to consumer (B2C) m-commerce applications that enable customers to access and browse product catalogue information on mobile devices, anytime, anywhere. Customers accessing electronic product catalogue information on a mobile device face a number of challenges such as a long list of products presented on a small screen and a longer information download time. These challenges mainly originate from the limiting and dynamic nature of the mobile apps operating environment, for example, dynamic location, bandwidth fluctuations and, diverse and limited device features, collectively referred to as context. The goal of this research was to design and implement a context-aware model that can be incorporated into an m-commerce application in order to improve the presentation of product catalogue information on m-commerce storefronts. The motivation for selecting product catalogue is prompted by literature which indicates that improved presentation of information in m-commerce (and e-commerce) applications has a positive impact on usability of the websites. Usable m-commerce (and e-commerce) websites improve efficiency in consumer behaviour that impacts sales, profits and business growth. The context-aware model aimed at collecting context information within the user environment and utilising it to determine optimal retrieval and presentation of product catalogue in m-commerce. An integrated logical context sensor and Mathematical algorithms were implemented in the context-aware model. The integrated logical context sensor was responsible for the collection of different types of predetermined context information such as device specification or capabilities, connection bandwidth, location and time of the day as well as the user profile. The algorithms transformed the collected context information into usable formats and enabled optimal retrieval and presentation of product catalogue data on a specific mobile device. Open-source implementation tools were utilised to implement components of the model including: HTML5, PhP, JavaScript and MySQL database. The context-aware model was incorporated into an existing m-commerce application. Two user evaluation studies were conducted during the course of the research. The first evaluation was to evaluate the accuracy of information collected by the context sensor component of the model. This survey was conducted with a sample of 30 users from different countries across the world. In-between the context sensor and main evaluation surveys, a pilot study was conducted with a sample of 19 users with great experience in mobile application development and use from SAP Next Business and Technology, Africa. Finally an overall user evaluation study was conducted with a sample of 30 users from a remote area called Kgautswane in Limpopo Province, South Africa. The results obtained indicate that the context-aware model was able to determine accurate context information in real-time and effectively determine how much product information should be retrieved and how the information should be presented on a mobile device interface. Two main contributions emerged from the research, first the research contributed to the field of mobile Human Computer Interaction. During the research, techniques of evaluating and improving usability of mobile applications were demonstrated. Secondly, the research made a significant contribution to the upcoming field of context-aware computing. The research brought clarity with regard to context-aware computing which is lacking in existing, current research despite the field’s proven impact of improving usability of applications. Researchers can utilise contributions made in this research to develop further techniques and usable context-aware solutions.
- Full Text:
- Date Issued: 2014
- Authors: Ntawanga, Felix Fred
- Date: 2014
- Subjects: Context-aware computing , Online information services
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10495 , http://hdl.handle.net/10948/d1020768
- Description: Online information access on mobile devices is increasing as a result of the growth in the use of Internet-enabled handheld (or pocket-size) devices. The combined influence of recent enabling technologies such as Web 2.0, mobile app stores and improved wireless networks have driven the increase in online applications that allow users to access various types of information on mobile devices regardless of time and location. Examples of such applications (usually shortened to app) include: social media, such as FacebookTM App and TwitterTM App, banking applications such as (Standard Bank South Africa)TM Mobile Banking App and First National Bank (FNB) BankingTM App, and news application such as news 24TM App and BBCTM News App. Online businesses involved in buying, selling and business transaction processing activities via the Internet have exploited the opportunity to extend electronic commerce (e-commerce) initiatives into mobile commerce (m-commerce). Online businesses that interact with end user customers implement business to consumer (B2C) m-commerce applications that enable customers to access and browse product catalogue information on mobile devices, anytime, anywhere. Customers accessing electronic product catalogue information on a mobile device face a number of challenges such as a long list of products presented on a small screen and a longer information download time. These challenges mainly originate from the limiting and dynamic nature of the mobile apps operating environment, for example, dynamic location, bandwidth fluctuations and, diverse and limited device features, collectively referred to as context. The goal of this research was to design and implement a context-aware model that can be incorporated into an m-commerce application in order to improve the presentation of product catalogue information on m-commerce storefronts. The motivation for selecting product catalogue is prompted by literature which indicates that improved presentation of information in m-commerce (and e-commerce) applications has a positive impact on usability of the websites. Usable m-commerce (and e-commerce) websites improve efficiency in consumer behaviour that impacts sales, profits and business growth. The context-aware model aimed at collecting context information within the user environment and utilising it to determine optimal retrieval and presentation of product catalogue in m-commerce. An integrated logical context sensor and Mathematical algorithms were implemented in the context-aware model. The integrated logical context sensor was responsible for the collection of different types of predetermined context information such as device specification or capabilities, connection bandwidth, location and time of the day as well as the user profile. The algorithms transformed the collected context information into usable formats and enabled optimal retrieval and presentation of product catalogue data on a specific mobile device. Open-source implementation tools were utilised to implement components of the model including: HTML5, PhP, JavaScript and MySQL database. The context-aware model was incorporated into an existing m-commerce application. Two user evaluation studies were conducted during the course of the research. The first evaluation was to evaluate the accuracy of information collected by the context sensor component of the model. This survey was conducted with a sample of 30 users from different countries across the world. In-between the context sensor and main evaluation surveys, a pilot study was conducted with a sample of 19 users with great experience in mobile application development and use from SAP Next Business and Technology, Africa. Finally an overall user evaluation study was conducted with a sample of 30 users from a remote area called Kgautswane in Limpopo Province, South Africa. The results obtained indicate that the context-aware model was able to determine accurate context information in real-time and effectively determine how much product information should be retrieved and how the information should be presented on a mobile device interface. Two main contributions emerged from the research, first the research contributed to the field of mobile Human Computer Interaction. During the research, techniques of evaluating and improving usability of mobile applications were demonstrated. Secondly, the research made a significant contribution to the upcoming field of context-aware computing. The research brought clarity with regard to context-aware computing which is lacking in existing, current research despite the field’s proven impact of improving usability of applications. Researchers can utilise contributions made in this research to develop further techniques and usable context-aware solutions.
- Full Text:
- Date Issued: 2014
A formalised ontology for network attack classification
- Authors: Van Heerden, Renier Pelser
- Date: 2014
- Subjects: Computer networks -- Security measures Computer security Computer crimes -- Investigation Computer crimes -- Prevention
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4691 , http://hdl.handle.net/10962/d1011603
- Description: One of the most popular attack vectors against computers are their network connections. Attacks on computers through their networks are commonplace and have various levels of complexity. This research formally describes network-based computer attacks in the form of a story, formally and within an ontology. The ontology categorises network attacks where attack scenarios are the focal class. This class consists of: Denial-of- Service, Industrial Espionage, Web Defacement, Unauthorised Data Access, Financial Theft, Industrial Sabotage, Cyber-Warfare, Resource Theft, System Compromise, and Runaway Malware. This ontology was developed by building a taxonomy and a temporal network attack model. Network attack instances (also know as individuals) are classified according to their respective attack scenarios, with the use of an automated reasoner within the ontology. The automated reasoner deductions are verified formally; and via the automated reasoner, a relaxed set of scenarios is determined, which is relevant in a near real-time environment. A prototype system (called Aeneas) was developed to classify network-based attacks. Aeneas integrates the sensors into a detection system that can classify network attacks in a near real-time environment. To verify the ontology and the prototype Aeneas, a virtual test bed was developed in which network-based attacks were generated to verify the detection system. Aeneas was able to detect incoming attacks and classify them according to their scenario. The novel part of this research is the attack scenarios that are described in the form of a story, as well as formally and in an ontology. The ontology is used in a novel way to determine to which class attack instances belong and how the network attack ontology is affected in a near real-time environment.
- Full Text:
- Date Issued: 2014
- Authors: Van Heerden, Renier Pelser
- Date: 2014
- Subjects: Computer networks -- Security measures Computer security Computer crimes -- Investigation Computer crimes -- Prevention
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4691 , http://hdl.handle.net/10962/d1011603
- Description: One of the most popular attack vectors against computers are their network connections. Attacks on computers through their networks are commonplace and have various levels of complexity. This research formally describes network-based computer attacks in the form of a story, formally and within an ontology. The ontology categorises network attacks where attack scenarios are the focal class. This class consists of: Denial-of- Service, Industrial Espionage, Web Defacement, Unauthorised Data Access, Financial Theft, Industrial Sabotage, Cyber-Warfare, Resource Theft, System Compromise, and Runaway Malware. This ontology was developed by building a taxonomy and a temporal network attack model. Network attack instances (also know as individuals) are classified according to their respective attack scenarios, with the use of an automated reasoner within the ontology. The automated reasoner deductions are verified formally; and via the automated reasoner, a relaxed set of scenarios is determined, which is relevant in a near real-time environment. A prototype system (called Aeneas) was developed to classify network-based attacks. Aeneas integrates the sensors into a detection system that can classify network attacks in a near real-time environment. To verify the ontology and the prototype Aeneas, a virtual test bed was developed in which network-based attacks were generated to verify the detection system. Aeneas was able to detect incoming attacks and classify them according to their scenario. The novel part of this research is the attack scenarios that are described in the form of a story, as well as formally and in an ontology. The ontology is used in a novel way to determine to which class attack instances belong and how the network attack ontology is affected in a near real-time environment.
- Full Text:
- Date Issued: 2014
A framework for business leadership in Africa
- Authors: Whitley, Elwyn
- Date: 2014
- Subjects: Leadership -- Africa Success in business , Management -- Africa Business Industrial management -- Africa
- Language: English
- Type: Thesis , Doctoral , DBA
- Identifier: http://hdl.handle.net/10948/45814 , vital:39219
- Description: In a fast moving, rapidly changing and highly competitive world the importance of strong leadership in both government and business cannot be over emphasised. The realisation that leadership is necessary for the organisation’s success and is key for the organisation’s survival (Alimo-Metcalfe and Alban- Metcalfe, 2008) is evident in the increasing focus on the concept over the last three to four decades. As the world becomes more of a ‘global village’ adapting to doing business in this new environment will require a leader who not only has the traditional skills set but also has the additional knowledge, skills and “mindset to navigate through the complexities brought on by moving beyond one's traditional borders” (Cohen, 2010. p. 3). This is of particular importance to Africa with the influx of foreign investors attracted by the growth opportunities that Africa offers, looking to expand their markets and in doing so imposing western norms and standards on local operations, in complex environments. Unfortunately Western leadership theories have not always been successful as Africans have found that in order to embrace Western ideals they need to relinquish some of their own beliefs. This highlights an opportunity to explore a possible hybrid leadership approach that harmonises the Western approach that is based on facts, logic and the nature of reality with the African humanistic orientation. The main aim of this study is to research the concept, principles, and characteristics of a small sample of business leaders in Africa in order to identify the factors that contribute to the leader’s success in a global business operating in Africa. By applying qualitative research methodology which includes an individual narrative written by each Managing Director, semistructured interviews and focus groups, a framework for business leadership in Africa was developed.
- Full Text:
- Date Issued: 2014
- Authors: Whitley, Elwyn
- Date: 2014
- Subjects: Leadership -- Africa Success in business , Management -- Africa Business Industrial management -- Africa
- Language: English
- Type: Thesis , Doctoral , DBA
- Identifier: http://hdl.handle.net/10948/45814 , vital:39219
- Description: In a fast moving, rapidly changing and highly competitive world the importance of strong leadership in both government and business cannot be over emphasised. The realisation that leadership is necessary for the organisation’s success and is key for the organisation’s survival (Alimo-Metcalfe and Alban- Metcalfe, 2008) is evident in the increasing focus on the concept over the last three to four decades. As the world becomes more of a ‘global village’ adapting to doing business in this new environment will require a leader who not only has the traditional skills set but also has the additional knowledge, skills and “mindset to navigate through the complexities brought on by moving beyond one's traditional borders” (Cohen, 2010. p. 3). This is of particular importance to Africa with the influx of foreign investors attracted by the growth opportunities that Africa offers, looking to expand their markets and in doing so imposing western norms and standards on local operations, in complex environments. Unfortunately Western leadership theories have not always been successful as Africans have found that in order to embrace Western ideals they need to relinquish some of their own beliefs. This highlights an opportunity to explore a possible hybrid leadership approach that harmonises the Western approach that is based on facts, logic and the nature of reality with the African humanistic orientation. The main aim of this study is to research the concept, principles, and characteristics of a small sample of business leaders in Africa in order to identify the factors that contribute to the leader’s success in a global business operating in Africa. By applying qualitative research methodology which includes an individual narrative written by each Managing Director, semistructured interviews and focus groups, a framework for business leadership in Africa was developed.
- Full Text:
- Date Issued: 2014
A framework to elicit user requirements for information systems: a localised participatory approach from Southern Africa
- Authors: Tyukala, Mkhululi
- Date: 2014
- Subjects: Information technology -- Africa, Southern , User-centered system design -- Africa, Southern , Management information systems -- Africa, Southern
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/4546 , vital:20615
- Description: The “What” and “Why” in information system development in resource restricted environments is already well covered in literature. However, the “How” to do it still has not been explored. This thesis reports on the development of a locally flavoured participatory user requirements elicitation framework for the development of information systems in resource restricted environments. It uses existing participatory design practices, user requirements elicitation literature and local participatory norms and traditions to achieve this. In doing so, it takes a step towards the way information systems could be developed in resource restricted environments. The topic of this thesis is mainly motivated by the recent calls in existing literature for developing countries to start developing their own information systems in order to address their own requirements. Accordingly, and to lay a foundation towards the realisation of this goal, this research is positioned within the user requirements elicitation region of information systems development. Current user requirements elicitation methods use traditional methods where experts/designers ask system users questions through interviews or learn about their environment through observations. This research proposes a shift from this approach to one that not only views users as equal partners in the elicitation process but in the whole information systems development process. This is in the spirit of participatory design, which was developed in Scandinavia more than four decades ago. Further, recent research in participatory design emphasises the importance of its contextual nature and concedes that there is no single best practice for participatory design in information systems that applies to all contexts. This research explores the information systems development discourse in resource restricted environments in Africa. Its purpose is to enhance understanding of the local contexts, thus providing new insights on how to develop a framework that speaks to local challenges using norms and traditions in order to develop information systems that address local requirements. Thus, the main contribution of this research lies in laying a foundation for a locally flavoured participatory approach for information systems development in resource restricted environments. It contributes to the existing information systems development, participatory design and user requirements elicitation body of knowledge by developing a framework for participatory user requirements elicitation. In addition, it contributes to the participatory design body of knowledge by introducing an age-old African participatory decisionmaking approach to the academic participatory design community. In doing so, it adopts the meaning of participation from an African value system point of view, which is something that has only been previously explored in the Nordic countries and North America. Finally, recommendations for the application, limitations and avenues for further research are incorporated into the findings of this research.
- Full Text:
- Date Issued: 2014
- Authors: Tyukala, Mkhululi
- Date: 2014
- Subjects: Information technology -- Africa, Southern , User-centered system design -- Africa, Southern , Management information systems -- Africa, Southern
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/4546 , vital:20615
- Description: The “What” and “Why” in information system development in resource restricted environments is already well covered in literature. However, the “How” to do it still has not been explored. This thesis reports on the development of a locally flavoured participatory user requirements elicitation framework for the development of information systems in resource restricted environments. It uses existing participatory design practices, user requirements elicitation literature and local participatory norms and traditions to achieve this. In doing so, it takes a step towards the way information systems could be developed in resource restricted environments. The topic of this thesis is mainly motivated by the recent calls in existing literature for developing countries to start developing their own information systems in order to address their own requirements. Accordingly, and to lay a foundation towards the realisation of this goal, this research is positioned within the user requirements elicitation region of information systems development. Current user requirements elicitation methods use traditional methods where experts/designers ask system users questions through interviews or learn about their environment through observations. This research proposes a shift from this approach to one that not only views users as equal partners in the elicitation process but in the whole information systems development process. This is in the spirit of participatory design, which was developed in Scandinavia more than four decades ago. Further, recent research in participatory design emphasises the importance of its contextual nature and concedes that there is no single best practice for participatory design in information systems that applies to all contexts. This research explores the information systems development discourse in resource restricted environments in Africa. Its purpose is to enhance understanding of the local contexts, thus providing new insights on how to develop a framework that speaks to local challenges using norms and traditions in order to develop information systems that address local requirements. Thus, the main contribution of this research lies in laying a foundation for a locally flavoured participatory approach for information systems development in resource restricted environments. It contributes to the existing information systems development, participatory design and user requirements elicitation body of knowledge by developing a framework for participatory user requirements elicitation. In addition, it contributes to the participatory design body of knowledge by introducing an age-old African participatory decisionmaking approach to the academic participatory design community. In doing so, it adopts the meaning of participation from an African value system point of view, which is something that has only been previously explored in the Nordic countries and North America. Finally, recommendations for the application, limitations and avenues for further research are incorporated into the findings of this research.
- Full Text:
- Date Issued: 2014
A lignocellulolytic enzyme system for fruit waste degradation : commercial enzyme mixture synergy and bioreactor design
- Authors: Gama, Repson
- Date: 2014
- Subjects: Enzymes -- Biotechnology , Enzymes -- Industrial applications , Lignocellulose -- Biodegradation , Biomass energy , Biomass conversion , Biochemical engineering , Agricultural wastes as fuel
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4114 , http://hdl.handle.net/10962/d1013073
- Description: Studies into sources of alternative liquid transport fuel energy have identified agro-industrial wastes, which are lignocellulosic in nature, as a potential feedstock for biofuel production against the background of depleting nonrenewable fossil fuels. In South Africa, large quantities of apple and other fruit wastes, called pomace, are generated from fruit and juice industries. Apple pomace is a rich source of cellulose, pectin and hemicellulose, making it a potential target for utilisation as a lignocellulosic feedstock for biofuel and biorefinery chemical production. Lignocellulosic biomass is recalcitrant in nature and therefore its degradation requires the synergistic action of a number of enzymes such as cellulases, hemicellulases, pectinases and ligninases. Commercial enzyme cocktails, containing some of these enzymes, are available and can be used for apple pomace degradation. In this study, the degradation of apple pomace using commercial enzyme cocktails was investigated. The main focus was the optimisation of the release of sugar monomers that could potentially be used for biofuel and biorefinery chemical production. There is no or little information reported in literature on the enzymatic degradation of fruit waste using commercial enzyme mixtures. This study first focused on the characterisation of the substrate (apple pomace) and the commercial enzyme cocktails. Apple pomace was found to contain mainly glucose, galacturonic acid, arabinose, galactose, lignin and low amounts of xylose and fructose. Three commercial enzyme cocktails were initially selected: Biocip Membrane, Viscozyme L (from Aspergillus aculeatus) and Celluclast 1.5L (a Trichoderma reesei ATCC 26921 cellulase preparation). The selection of the enzymes was based on activities declared by the manufacturers, cost and local availability. The enzymes were screened based on their synergistic cooperation in the degradation of apple pomace and the main enzymes present in each cocktail. Viscozyme L and Celluclast 1.5L, in a 50:50 ratio, resulted in the best degree of synergy (1.6) compared to any other combination. The enzyme ratios were determined on Viscozyme L and Celluclast 1.5L based on the protein ratio. Enzyme activity was determined as glucose equivalents using the dinitrosalicylic acid (DNS) method. Sugar monomers were determined using Megazyme assay kits. There is limited information available on the enzymes present in the commercial enzyme cocktails. Therefore, the main enzymes present in Viscozyme L and Celluclast 1.5L were identified using different substrates, each targeted for a specific enzyme and activity. Characterisation of the enzyme mixtures revealed a large number of enzymes required for apple pomace degradation and these included cellulases, pectinases, xylanases, arabinases and mannanases in different proportions. Viscozyme L contained mainly pectinases and hemicellulases, while Celluclast 1.5L displayed largely cellulase and xylanase activity, hence the high degree of synergy reported. The temperature optimum was 50ºC for both enzyme mixtures and pH optima were observed at pH 5.0 and pH 3.0 for Viscozyme L and Celluclast 1.5L, respectively. At 37ºC and pH 5.0, the enzymes retained more that 90% activity after 15 days of incubation, allowing the enzymes to be used together with less energy input. The enzymes were further characterised by determining the effect of various compounds, such as alcohols, sugars, phenolic compounds and metal ions at various concentrations on the activity of the enzymes during apple pomace hydrolysis. Apart from lignin, which had almost no effect on enzyme activity, all the compounds caused inhibition of the enzymes to varying degrees. The most inhibitory compounds were some organic acids and metal ions, as well as cellobiose and xylobiose. Using the best ratio for Viscozyme L and Celluclast 1.5L (50:50) for the hydrolysis of apple pomace, it was observed that synergy was highest at the initial stages of hydrolysis and decreased over time, though the sugar concentration increased. The type of synergy for optimal apple pomace hydrolysis was found to be simultaneous. There was no synergy observed between Viscozyme L and Celluclast 1.5L with ligninases - laccase, lignin peroxidase and manganese peroxidase. Hydrolysing apple pomace with ligninases prior to addition of Viscozyme L and Celluclast 1.5L did not improve degradation of the substrate. Immobilisation of the enzyme mixtures on different supports was performed with the aim of increasing stability and enabling reuse of the enzymes. Immobilisation methods were selected based on the chemical properties of the supports, availability, cost and applicability on heterogeneous and insoluble substrate like apple pomace. These methods included crosslinked enzyme aggregates (CLEAs), immobilisation on various supports such as nylon mesh, nylon beads, sodium alginate beads, chitin and silica gel beads. The immobilisation strategies were unsuccessful, mainly due to the low percentage of immobilisation of the enzyme on the matrix and loss of activity of the immobilised enzyme. Free enzymes were therefore used for the remainder of the study. Hydrolysis conditions for apple pomace degradation were optimised using different temperatures and buffer systems in 1 L volumes mixed with compressed air. Hydrolysis at room temperature, using an unbuffered system, gave a better performance as compared to a buffered system. Reactors operated in batch mode performed better (4.2 g/L (75% yield) glucose and 16.8 g/L (75%) reducing sugar) than fed-batch reactors (3.2 g/L (66%) glucose and 14.6 g/L (72.7% yield) reducing sugar) over 100 h using Viscozyme L and Celluclast 1.5L. Supplementation of β- glucosidase activity in Viscozyme L and Celluclast 1.5L with Novozyme 188 resulted in a doubling of the amount of glucose released. The main products released from apple pomace hydrolysis were galacturonic acid, glucose and arabinose and low amounts of galactose and xylose. These products are potential raw materials for biofuel and biorefinery chemical production. An artificial neural network (ANN) model was successfully developed and used for predicting the optimum conditions for apple pomace hydrolysis using Celluclast 1.5L, Viscozyme L and Novozyme 188. Four main conditions that affect apple pomace hydrolysis were selected, namely temperature, initial pH, enzyme loading and substrate loading, which were taken as inputs. The glucose and reducing sugars released as a result of each treatment and their combinations were taken as outputs for 1–100 h. An ANN with 20, 20 and 6 neurons in the first, second and third hidden layers, respectively, was constructed. The performance and predictive ability of the ANN was good, with a R² of 0.99 and a small mean square error (MSE). New data was successfully predicted and simulated. Optimal hydrolysis conditions predicted by ANN for apple pomace hydrolysis were at 30% substrate (wet w/v) and an enzyme loading of 0.5 mg/g and 0.2 mg/mL of substrate for glucose and reducing sugar, respectively, giving sugar concentrations of 6.5 mg/mL and 28.9 mg/mL for glucose and reducing sugar, respectively. ANN showed that enzyme and substrate loadings were the most important factors for the hydrolysis of apple pomace.
- Full Text:
- Date Issued: 2014
- Authors: Gama, Repson
- Date: 2014
- Subjects: Enzymes -- Biotechnology , Enzymes -- Industrial applications , Lignocellulose -- Biodegradation , Biomass energy , Biomass conversion , Biochemical engineering , Agricultural wastes as fuel
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4114 , http://hdl.handle.net/10962/d1013073
- Description: Studies into sources of alternative liquid transport fuel energy have identified agro-industrial wastes, which are lignocellulosic in nature, as a potential feedstock for biofuel production against the background of depleting nonrenewable fossil fuels. In South Africa, large quantities of apple and other fruit wastes, called pomace, are generated from fruit and juice industries. Apple pomace is a rich source of cellulose, pectin and hemicellulose, making it a potential target for utilisation as a lignocellulosic feedstock for biofuel and biorefinery chemical production. Lignocellulosic biomass is recalcitrant in nature and therefore its degradation requires the synergistic action of a number of enzymes such as cellulases, hemicellulases, pectinases and ligninases. Commercial enzyme cocktails, containing some of these enzymes, are available and can be used for apple pomace degradation. In this study, the degradation of apple pomace using commercial enzyme cocktails was investigated. The main focus was the optimisation of the release of sugar monomers that could potentially be used for biofuel and biorefinery chemical production. There is no or little information reported in literature on the enzymatic degradation of fruit waste using commercial enzyme mixtures. This study first focused on the characterisation of the substrate (apple pomace) and the commercial enzyme cocktails. Apple pomace was found to contain mainly glucose, galacturonic acid, arabinose, galactose, lignin and low amounts of xylose and fructose. Three commercial enzyme cocktails were initially selected: Biocip Membrane, Viscozyme L (from Aspergillus aculeatus) and Celluclast 1.5L (a Trichoderma reesei ATCC 26921 cellulase preparation). The selection of the enzymes was based on activities declared by the manufacturers, cost and local availability. The enzymes were screened based on their synergistic cooperation in the degradation of apple pomace and the main enzymes present in each cocktail. Viscozyme L and Celluclast 1.5L, in a 50:50 ratio, resulted in the best degree of synergy (1.6) compared to any other combination. The enzyme ratios were determined on Viscozyme L and Celluclast 1.5L based on the protein ratio. Enzyme activity was determined as glucose equivalents using the dinitrosalicylic acid (DNS) method. Sugar monomers were determined using Megazyme assay kits. There is limited information available on the enzymes present in the commercial enzyme cocktails. Therefore, the main enzymes present in Viscozyme L and Celluclast 1.5L were identified using different substrates, each targeted for a specific enzyme and activity. Characterisation of the enzyme mixtures revealed a large number of enzymes required for apple pomace degradation and these included cellulases, pectinases, xylanases, arabinases and mannanases in different proportions. Viscozyme L contained mainly pectinases and hemicellulases, while Celluclast 1.5L displayed largely cellulase and xylanase activity, hence the high degree of synergy reported. The temperature optimum was 50ºC for both enzyme mixtures and pH optima were observed at pH 5.0 and pH 3.0 for Viscozyme L and Celluclast 1.5L, respectively. At 37ºC and pH 5.0, the enzymes retained more that 90% activity after 15 days of incubation, allowing the enzymes to be used together with less energy input. The enzymes were further characterised by determining the effect of various compounds, such as alcohols, sugars, phenolic compounds and metal ions at various concentrations on the activity of the enzymes during apple pomace hydrolysis. Apart from lignin, which had almost no effect on enzyme activity, all the compounds caused inhibition of the enzymes to varying degrees. The most inhibitory compounds were some organic acids and metal ions, as well as cellobiose and xylobiose. Using the best ratio for Viscozyme L and Celluclast 1.5L (50:50) for the hydrolysis of apple pomace, it was observed that synergy was highest at the initial stages of hydrolysis and decreased over time, though the sugar concentration increased. The type of synergy for optimal apple pomace hydrolysis was found to be simultaneous. There was no synergy observed between Viscozyme L and Celluclast 1.5L with ligninases - laccase, lignin peroxidase and manganese peroxidase. Hydrolysing apple pomace with ligninases prior to addition of Viscozyme L and Celluclast 1.5L did not improve degradation of the substrate. Immobilisation of the enzyme mixtures on different supports was performed with the aim of increasing stability and enabling reuse of the enzymes. Immobilisation methods were selected based on the chemical properties of the supports, availability, cost and applicability on heterogeneous and insoluble substrate like apple pomace. These methods included crosslinked enzyme aggregates (CLEAs), immobilisation on various supports such as nylon mesh, nylon beads, sodium alginate beads, chitin and silica gel beads. The immobilisation strategies were unsuccessful, mainly due to the low percentage of immobilisation of the enzyme on the matrix and loss of activity of the immobilised enzyme. Free enzymes were therefore used for the remainder of the study. Hydrolysis conditions for apple pomace degradation were optimised using different temperatures and buffer systems in 1 L volumes mixed with compressed air. Hydrolysis at room temperature, using an unbuffered system, gave a better performance as compared to a buffered system. Reactors operated in batch mode performed better (4.2 g/L (75% yield) glucose and 16.8 g/L (75%) reducing sugar) than fed-batch reactors (3.2 g/L (66%) glucose and 14.6 g/L (72.7% yield) reducing sugar) over 100 h using Viscozyme L and Celluclast 1.5L. Supplementation of β- glucosidase activity in Viscozyme L and Celluclast 1.5L with Novozyme 188 resulted in a doubling of the amount of glucose released. The main products released from apple pomace hydrolysis were galacturonic acid, glucose and arabinose and low amounts of galactose and xylose. These products are potential raw materials for biofuel and biorefinery chemical production. An artificial neural network (ANN) model was successfully developed and used for predicting the optimum conditions for apple pomace hydrolysis using Celluclast 1.5L, Viscozyme L and Novozyme 188. Four main conditions that affect apple pomace hydrolysis were selected, namely temperature, initial pH, enzyme loading and substrate loading, which were taken as inputs. The glucose and reducing sugars released as a result of each treatment and their combinations were taken as outputs for 1–100 h. An ANN with 20, 20 and 6 neurons in the first, second and third hidden layers, respectively, was constructed. The performance and predictive ability of the ANN was good, with a R² of 0.99 and a small mean square error (MSE). New data was successfully predicted and simulated. Optimal hydrolysis conditions predicted by ANN for apple pomace hydrolysis were at 30% substrate (wet w/v) and an enzyme loading of 0.5 mg/g and 0.2 mg/mL of substrate for glucose and reducing sugar, respectively, giving sugar concentrations of 6.5 mg/mL and 28.9 mg/mL for glucose and reducing sugar, respectively. ANN showed that enzyme and substrate loadings were the most important factors for the hydrolysis of apple pomace.
- Full Text:
- Date Issued: 2014
A mathematics rendering model to support chat-based tutoring
- Authors: Haskins, Bertram Peter
- Date: 2014
- Subjects: Intelligent tutoring systems , Educational innovations , Tutors and tutoring
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9822 , http://hdl.handle.net/10948/d1020567
- Description: Dr Math is a math tutoring service implemented on the chat application Mxit. The service allows school learners to use their mobile phones to discuss mathematicsrelated topics with human tutors. Using the broad user-base provided by Mxit, the Dr Math service has grown to consist of tens of thousands of registered school learners. The tutors on the service are all volunteers and the learners far outnumber the available tutors at any given time. School learners on the service use a shorthand language-form called microtext, to phrase their queries. Microtext is an informal form of language which consists of a variety of misspellings and symbolic representations, which emerge spontaneously as a result of the idiosyncrasies of a learner. The specific form of microtext found on the Dr Math service contains mathematical questions and example equations, pertaining to the tutoring process. Deciphering the queries, to discover their embedded mathematical content, slows down the tutoring process. This wastes time that could have been spent addressing more learner queries. The microtext language thus creates an unnecessary burden on the tutors. This study describes the development of an automated process for the translation of Dr Math microtext queries into mathematical equations. Using the design science research paradigm as a guide, three artefacts are developed. These artefacts take the form of a construct, a model and an instantiation. The construct represents the creation of new knowledge as it provides greater insight into the contents and structure of the language found on a mobile mathematics tutoring service. The construct serves as the basis for the creation of a model for the translation of microtext queries into mathematical equations, formatted for display in an electronic medium. No such technique currently exists and therefore, the model contributes new knowledge. To validate the model, an instantiation was created to serve as a proof-of-concept. The instantiation applies various concepts and techniques, such as those related to natural language processing, to the learner queries on the Dr Math service. These techniques are employed in order to translate an input microtext statement into a mathematical equation, structured by using mark-up language. The creation of the instantiation thus constitutes a knowledge contribution, as most of these techniques have never been applied to the problem of translating microtext into mathematical equations. For the automated process to have utility, it should perform on a level comparable to that of a human performing a similar translation task. To determine how closely related the results from the automated process are to those of a human, three human participants were asked to perform coding and translation tasks. The results of the human participants were compared to the results of the automated process, across a variety of metrics, including agreement, correlation, precision, recall and others. The results from the human participants served as the baseline values for comparison. The baseline results from the human participants were compared with those of the automated process. Krippendorff’s α was used to determine the level of agreement and Pearson’s correlation coefficient to determine the level of correlation between the results. The agreement between the human participants and the automated process was calculated at a level deemed satisfactory for exploratory research and the level of correlation was calculated as moderate. These values correspond with the calculations made as the human baseline. Furthermore, the automated process was able to meet or improve on all of the human baseline metrics. These results serve to validate that the automated process is able to perform the translation at a level comparable to that of a human. The automated process is available for integration into any requesting application, by means of a publicly accessible web service.
- Full Text:
- Date Issued: 2014
- Authors: Haskins, Bertram Peter
- Date: 2014
- Subjects: Intelligent tutoring systems , Educational innovations , Tutors and tutoring
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9822 , http://hdl.handle.net/10948/d1020567
- Description: Dr Math is a math tutoring service implemented on the chat application Mxit. The service allows school learners to use their mobile phones to discuss mathematicsrelated topics with human tutors. Using the broad user-base provided by Mxit, the Dr Math service has grown to consist of tens of thousands of registered school learners. The tutors on the service are all volunteers and the learners far outnumber the available tutors at any given time. School learners on the service use a shorthand language-form called microtext, to phrase their queries. Microtext is an informal form of language which consists of a variety of misspellings and symbolic representations, which emerge spontaneously as a result of the idiosyncrasies of a learner. The specific form of microtext found on the Dr Math service contains mathematical questions and example equations, pertaining to the tutoring process. Deciphering the queries, to discover their embedded mathematical content, slows down the tutoring process. This wastes time that could have been spent addressing more learner queries. The microtext language thus creates an unnecessary burden on the tutors. This study describes the development of an automated process for the translation of Dr Math microtext queries into mathematical equations. Using the design science research paradigm as a guide, three artefacts are developed. These artefacts take the form of a construct, a model and an instantiation. The construct represents the creation of new knowledge as it provides greater insight into the contents and structure of the language found on a mobile mathematics tutoring service. The construct serves as the basis for the creation of a model for the translation of microtext queries into mathematical equations, formatted for display in an electronic medium. No such technique currently exists and therefore, the model contributes new knowledge. To validate the model, an instantiation was created to serve as a proof-of-concept. The instantiation applies various concepts and techniques, such as those related to natural language processing, to the learner queries on the Dr Math service. These techniques are employed in order to translate an input microtext statement into a mathematical equation, structured by using mark-up language. The creation of the instantiation thus constitutes a knowledge contribution, as most of these techniques have never been applied to the problem of translating microtext into mathematical equations. For the automated process to have utility, it should perform on a level comparable to that of a human performing a similar translation task. To determine how closely related the results from the automated process are to those of a human, three human participants were asked to perform coding and translation tasks. The results of the human participants were compared to the results of the automated process, across a variety of metrics, including agreement, correlation, precision, recall and others. The results from the human participants served as the baseline values for comparison. The baseline results from the human participants were compared with those of the automated process. Krippendorff’s α was used to determine the level of agreement and Pearson’s correlation coefficient to determine the level of correlation between the results. The agreement between the human participants and the automated process was calculated at a level deemed satisfactory for exploratory research and the level of correlation was calculated as moderate. These values correspond with the calculations made as the human baseline. Furthermore, the automated process was able to meet or improve on all of the human baseline metrics. These results serve to validate that the automated process is able to perform the translation at a level comparable to that of a human. The automated process is available for integration into any requesting application, by means of a publicly accessible web service.
- Full Text:
- Date Issued: 2014
A method for the evaluation of similarity measures on graphs and network-structured data
- Authors: Naude, Kevin Alexander
- Date: 2014
- Subjects: Graph theory , Network analysis (Planning)
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:10494
- Description: Measures of similarity play a subtle but important role in a large number of disciplines. For example, a researcher in bioinformatics may devise a new computed measure of similarity between biological structures, and use its scores to infer bio-logical association. Other academics may use related approaches in structured text search, or for object recognition in computer vision. These are diverse and practical applications of similarity. A critical question is this: to what extent can a given similarity measure be trusted? This is a difficult problem, at the heart of which lies the broader issue: what exactly constitutes good similarity judgement? This research presents the view that similarity measures have properties of judgement that are intrinsic to their formulation, and that such properties are measurable. The problem of comparing similarity measures is one of identifying ground-truths for similarity. The approach taken in this work is to examine the relative ordering of graph pairs, when compared with respect to a common reference graph. Ground- truth outcomes are obtained from a novel theory: the theory of irreducible change in graphs. This theory supports stronger claims than those made for edit distances. Whereas edit distances are sensitive to a configuration of costs, irreducible change under the new theory is independent of such parameters. Ground-truth data is obtained by isolating test cases for which a common outcome is assured for all possible least measures of change that can be formulated within a chosen change descriptor space. By isolating these specific cases, and excluding others, the research introduces a framework for evaluating similarity measures on mathematically defensible grounds. The evaluation method is demonstrated in a series of case studies which evaluate the similarity performance of known graph similarity measures. The findings of these experiments provide the first general characterisation of common similarity measures over a wide range of graph properties. The similarity computed from the maximum common induced subgraph (Dice-MCIS) is shown to provide good general similarity judgement. However, it is shown that Blondel's similarity measure can exceed the judgement sensitivity of Dice-MCIS, provided the graphs have both sufficient attribute label diversity, and edge density. The final contribution is the introduction of a new similarity measure for graphs, which is shown to have statistically greater judgement sensitivity than all other measures examined. All of these findings are made possible through the theory of irreducible change in graphs. The research provides the first mathematical basis for reasoning about the quality of similarity judgments. This enables researchers to analyse similarity measures directly, making similarity measures first class objects of scientific inquiry.
- Full Text:
- Date Issued: 2014
- Authors: Naude, Kevin Alexander
- Date: 2014
- Subjects: Graph theory , Network analysis (Planning)
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:10494
- Description: Measures of similarity play a subtle but important role in a large number of disciplines. For example, a researcher in bioinformatics may devise a new computed measure of similarity between biological structures, and use its scores to infer bio-logical association. Other academics may use related approaches in structured text search, or for object recognition in computer vision. These are diverse and practical applications of similarity. A critical question is this: to what extent can a given similarity measure be trusted? This is a difficult problem, at the heart of which lies the broader issue: what exactly constitutes good similarity judgement? This research presents the view that similarity measures have properties of judgement that are intrinsic to their formulation, and that such properties are measurable. The problem of comparing similarity measures is one of identifying ground-truths for similarity. The approach taken in this work is to examine the relative ordering of graph pairs, when compared with respect to a common reference graph. Ground- truth outcomes are obtained from a novel theory: the theory of irreducible change in graphs. This theory supports stronger claims than those made for edit distances. Whereas edit distances are sensitive to a configuration of costs, irreducible change under the new theory is independent of such parameters. Ground-truth data is obtained by isolating test cases for which a common outcome is assured for all possible least measures of change that can be formulated within a chosen change descriptor space. By isolating these specific cases, and excluding others, the research introduces a framework for evaluating similarity measures on mathematically defensible grounds. The evaluation method is demonstrated in a series of case studies which evaluate the similarity performance of known graph similarity measures. The findings of these experiments provide the first general characterisation of common similarity measures over a wide range of graph properties. The similarity computed from the maximum common induced subgraph (Dice-MCIS) is shown to provide good general similarity judgement. However, it is shown that Blondel's similarity measure can exceed the judgement sensitivity of Dice-MCIS, provided the graphs have both sufficient attribute label diversity, and edge density. The final contribution is the introduction of a new similarity measure for graphs, which is shown to have statistically greater judgement sensitivity than all other measures examined. All of these findings are made possible through the theory of irreducible change in graphs. The research provides the first mathematical basis for reasoning about the quality of similarity judgments. This enables researchers to analyse similarity measures directly, making similarity measures first class objects of scientific inquiry.
- Full Text:
- Date Issued: 2014
A sociological analysis of the provision of extended studies as a means of addressing transformation at a historically white university
- Authors: Tanyanyiwa, Precious
- Date: 2014
- Subjects: Rhodes University , Articulation (Education) , Articulation (Education) -- South Africa -- Grahamstown , Educational equalization -- South Africa -- Grahamstown , Discrimination in education -- South Africa -- Grahamstown , Education, Higher -- South Africa -- Grahamstown , Bourdieu, Pierre, 1930-2002 , Sen, Amartya, 1933-
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3370 , http://hdl.handle.net/10962/d1012655
- Description: Foundation provisioning has a long history in South Africa, and is central to the transformation agenda, particularly the broadening of successful participation in higher education (HE). As access initiatives underpinned by various conceptualisations, foundation programmes evolved from peripheral, to semi-integrated and finally fully integrated curricular models in the form of current Extended Studies Programmes (ESPs). Underpinning the provision of Extended Studies is the acknowledgment that students who enter institutions are essentially ill equipped to cope with the demands of higher education studies, “leaving institutions themselves free of the responsibility of student failure” (Akoojee & Nkomo, 2007:391). This under-preparedness has been attributed to the ‘articulation gap’ between secondary and higher education, which in turn contributes to low retention and graduation rates (CHE, 2013:17). Situated within an overarching commitment to access and success, the Extended Studies Programme attempts to systematically address the ‘articulation gap’. This study evaluated the extent to which the Rhodes University Humanities Extended Studies Programme is achieving its objectives from a transformation perspective, specifically the broadening of successful participation in higher education. The majority of previous works on the evaluation of foundation programmes focused on measurable dimensions of student access and success – that is retention and graduation rates. This thesis considered both the measurable outcomes of the programme as well as the actual teaching and learning process. Given the shifts that have taken place in foundation provisioning, the evaluation of the current model of foundation provisioning necessitated their location in history. Therefore, the evaluation of the Rhodes University Humanities Extended Studies Programme was undertaken in view of the shifts, achievements, challenges and critics of its predecessor programmes. Specifically, the following dimensions were considered in the evaluation of the programme: i) assumptions underpinning the design and purpose of the programme, ii) teaching and learning practices in the programme, iii) student and staff perceptions of the programme, iv) students’ experiences of the programme, v) the validity of the programme in the broader institution, and vi) the measurable outcomes of the programme − that is retention and graduation rates of students enrolled in the programme. The triangulation of qualitative data collection techniques provided access into the different layers of institutional relations, processes and structures, which not only affect teaching and learning in the programme, but also determine students’ engagement with different academic and social aspects of the broader university. The theoretical insights of Pierre Bourdieu and Amartya Sen were integrated in order to provide analytical tools for both understanding the causes of inequalities in higher education, and evaluating institutional processes and structures that perpetuate or transform inequalities. Whilst Bourdieu’s social reproduction thesis exposed the ways in which social structures shape educational processes and outcomes, Sen’s capability approach provided tools for evaluating both institutional arrangements and individual capabilities – that is, the freedom to achieve desired educational outcomes (Sen, 1992:48).
- Full Text:
- Date Issued: 2014
- Authors: Tanyanyiwa, Precious
- Date: 2014
- Subjects: Rhodes University , Articulation (Education) , Articulation (Education) -- South Africa -- Grahamstown , Educational equalization -- South Africa -- Grahamstown , Discrimination in education -- South Africa -- Grahamstown , Education, Higher -- South Africa -- Grahamstown , Bourdieu, Pierre, 1930-2002 , Sen, Amartya, 1933-
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3370 , http://hdl.handle.net/10962/d1012655
- Description: Foundation provisioning has a long history in South Africa, and is central to the transformation agenda, particularly the broadening of successful participation in higher education (HE). As access initiatives underpinned by various conceptualisations, foundation programmes evolved from peripheral, to semi-integrated and finally fully integrated curricular models in the form of current Extended Studies Programmes (ESPs). Underpinning the provision of Extended Studies is the acknowledgment that students who enter institutions are essentially ill equipped to cope with the demands of higher education studies, “leaving institutions themselves free of the responsibility of student failure” (Akoojee & Nkomo, 2007:391). This under-preparedness has been attributed to the ‘articulation gap’ between secondary and higher education, which in turn contributes to low retention and graduation rates (CHE, 2013:17). Situated within an overarching commitment to access and success, the Extended Studies Programme attempts to systematically address the ‘articulation gap’. This study evaluated the extent to which the Rhodes University Humanities Extended Studies Programme is achieving its objectives from a transformation perspective, specifically the broadening of successful participation in higher education. The majority of previous works on the evaluation of foundation programmes focused on measurable dimensions of student access and success – that is retention and graduation rates. This thesis considered both the measurable outcomes of the programme as well as the actual teaching and learning process. Given the shifts that have taken place in foundation provisioning, the evaluation of the current model of foundation provisioning necessitated their location in history. Therefore, the evaluation of the Rhodes University Humanities Extended Studies Programme was undertaken in view of the shifts, achievements, challenges and critics of its predecessor programmes. Specifically, the following dimensions were considered in the evaluation of the programme: i) assumptions underpinning the design and purpose of the programme, ii) teaching and learning practices in the programme, iii) student and staff perceptions of the programme, iv) students’ experiences of the programme, v) the validity of the programme in the broader institution, and vi) the measurable outcomes of the programme − that is retention and graduation rates of students enrolled in the programme. The triangulation of qualitative data collection techniques provided access into the different layers of institutional relations, processes and structures, which not only affect teaching and learning in the programme, but also determine students’ engagement with different academic and social aspects of the broader university. The theoretical insights of Pierre Bourdieu and Amartya Sen were integrated in order to provide analytical tools for both understanding the causes of inequalities in higher education, and evaluating institutional processes and structures that perpetuate or transform inequalities. Whilst Bourdieu’s social reproduction thesis exposed the ways in which social structures shape educational processes and outcomes, Sen’s capability approach provided tools for evaluating both institutional arrangements and individual capabilities – that is, the freedom to achieve desired educational outcomes (Sen, 1992:48).
- Full Text:
- Date Issued: 2014
A sociological study of employees' perceptions of electronic surveillance in public FET institutions in the Eastern Cape Province, South Africa
- Authors: Jonas, Randolph Patrick
- Date: 2014
- Subjects: Electronic monitoring in the workplace -- South Africa -- Eastern Cape , Privacy, Right of -- South Africa -- Eastern Cape , Personnel management -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:16154 , http://hdl.handle.net/10948/d1020623
- Description: The perceptions of employees regarding electronic surveillance in the workplace were studied using a mixed method approach. The change that permeates society and organisations have not escaped public FET institutions in South Africa. These changes such as computerisation of work and the employment of electronic surveillance, have implications for management, control, privacy, productivity and trust in the workplace. Yet, public FET institutions are not performing to the expected standards. Surveillance of work and employees at these institutions are interventions of management to ensure organisational goals are achieved. Despite the prevalence of electronic surveillance in the workplace, employee perceptions and their lived experiences thereof are seldom reported. Published research barely focuses on employees’ perceptions of electronic surveillance in the workplace, and instead offers a perfunctory look at the perceptual dimensions. Employees’ perceptions reflects their lived experiences in the workplace and yield a foundational understanding of workplace dynamics and organisational behaviour. The perceptions of employees regarding electronic surveillance were viewed through the lens of quantitative and qualitative analysis to give statistical and thick descriptions respectively to augment better understanding. The study therefore provides a descriptive account of employees’ perceptions of electronic surveillance and its effects. Specifically the study examined employee perceptions of electronic surveillance as a control measure of management, as an intrusion of employee privacy and impacting on the trust relationship and productivity. An extensive review of the literature provided the basis for the research questions and eight hypotheses were proposed. A survey, by means of an electronic questionnaire, was conducted to test the hypotheses using a random sample of employees at three public FET institutions in the Eastern Cape Province, South Africa. The results are presented followed by a discussion, conclusions and limitations. Suggestions and recommendations for future research are also indicated. The central thesis of the study is presented, namely that electronic surveillance is experienced as a measure of management to control workers and that privacy as well trust, as an element of the employment relationship, are influenced by it. Further findings indicated that there are no statistically significant differences in the responses of the three job categories namely lecturers, managers and administration and support staff. Interviews were also conducted and the data from the interviews reported the depth and breadth of the perceptions of a small sample of employees who related their experiences and situations in terms of the key themes of electronic surveillance as control and an intrusion of their right to privacy, trust and productivity. The findings indicate that acceptance of electronic surveillance is contingent upon contextual factors and the meaning people assign to their situations. Privacy concerns were limited to personal information, fairness and dignity. The link between electronic surveillance and control and discipline is reported in the responses. The findings indicate that perceptions of electronic surveillance as managerial control is related to the lived experiences of employees. Employees voiced positive perceptions of electronic surveillance in cases where management clearly communicates the purpose to the employees. The study of the subjective experiences of employees in workplaces under electronic surveillance thus helped to illuminate the intricacies of employment relationships in the changing world of work. The study findings widen the knowledge base on organisational behaviour and is essential for human resources management and organisational development interventions. Human rights and ethics are part of the sense making process when employees construct social reality. Management and control is redefined in various terms and has implications for change management strategies and organisational development practises in globalising and network society. The study raises the critical question whether electronic surveillance as an adjunct for bureaucratic control is still relevant in a changing world of work where good faith, trust and confidence are still highly valued. The insights into the role of trust in the employment relationship is important for managing public institutions in complex settings. Management must be aware of the differences in the lived experiences of employees when dealing with workplace issues.
- Full Text:
- Date Issued: 2014
- Authors: Jonas, Randolph Patrick
- Date: 2014
- Subjects: Electronic monitoring in the workplace -- South Africa -- Eastern Cape , Privacy, Right of -- South Africa -- Eastern Cape , Personnel management -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:16154 , http://hdl.handle.net/10948/d1020623
- Description: The perceptions of employees regarding electronic surveillance in the workplace were studied using a mixed method approach. The change that permeates society and organisations have not escaped public FET institutions in South Africa. These changes such as computerisation of work and the employment of electronic surveillance, have implications for management, control, privacy, productivity and trust in the workplace. Yet, public FET institutions are not performing to the expected standards. Surveillance of work and employees at these institutions are interventions of management to ensure organisational goals are achieved. Despite the prevalence of electronic surveillance in the workplace, employee perceptions and their lived experiences thereof are seldom reported. Published research barely focuses on employees’ perceptions of electronic surveillance in the workplace, and instead offers a perfunctory look at the perceptual dimensions. Employees’ perceptions reflects their lived experiences in the workplace and yield a foundational understanding of workplace dynamics and organisational behaviour. The perceptions of employees regarding electronic surveillance were viewed through the lens of quantitative and qualitative analysis to give statistical and thick descriptions respectively to augment better understanding. The study therefore provides a descriptive account of employees’ perceptions of electronic surveillance and its effects. Specifically the study examined employee perceptions of electronic surveillance as a control measure of management, as an intrusion of employee privacy and impacting on the trust relationship and productivity. An extensive review of the literature provided the basis for the research questions and eight hypotheses were proposed. A survey, by means of an electronic questionnaire, was conducted to test the hypotheses using a random sample of employees at three public FET institutions in the Eastern Cape Province, South Africa. The results are presented followed by a discussion, conclusions and limitations. Suggestions and recommendations for future research are also indicated. The central thesis of the study is presented, namely that electronic surveillance is experienced as a measure of management to control workers and that privacy as well trust, as an element of the employment relationship, are influenced by it. Further findings indicated that there are no statistically significant differences in the responses of the three job categories namely lecturers, managers and administration and support staff. Interviews were also conducted and the data from the interviews reported the depth and breadth of the perceptions of a small sample of employees who related their experiences and situations in terms of the key themes of electronic surveillance as control and an intrusion of their right to privacy, trust and productivity. The findings indicate that acceptance of electronic surveillance is contingent upon contextual factors and the meaning people assign to their situations. Privacy concerns were limited to personal information, fairness and dignity. The link between electronic surveillance and control and discipline is reported in the responses. The findings indicate that perceptions of electronic surveillance as managerial control is related to the lived experiences of employees. Employees voiced positive perceptions of electronic surveillance in cases where management clearly communicates the purpose to the employees. The study of the subjective experiences of employees in workplaces under electronic surveillance thus helped to illuminate the intricacies of employment relationships in the changing world of work. The study findings widen the knowledge base on organisational behaviour and is essential for human resources management and organisational development interventions. Human rights and ethics are part of the sense making process when employees construct social reality. Management and control is redefined in various terms and has implications for change management strategies and organisational development practises in globalising and network society. The study raises the critical question whether electronic surveillance as an adjunct for bureaucratic control is still relevant in a changing world of work where good faith, trust and confidence are still highly valued. The insights into the role of trust in the employment relationship is important for managing public institutions in complex settings. Management must be aware of the differences in the lived experiences of employees when dealing with workplace issues.
- Full Text:
- Date Issued: 2014
A sustainability reporting framework for South African Higher Education Institutions
- Authors: Bosire, Samuel Mobisa
- Date: 2014
- Subjects: Sustainable development reporting -- South Africa , Business intelligence -- South Africa , Universities and colleges -- South Africa , Corporate governance -- South Africa
- Language: English
- Type: Thesis , Doctoral , DBA
- Identifier: vital:8798 , http://hdl.handle.net/10948/d1016126
- Description: Sustainability has gained prominence globally among nations, regions and organisations as a result of factors such as the effects of climate change on the environment, diminishing natural resources and rising population growth with their concomitant impact on economies and social systems. South Africa is a signatory to the United Nations Global Compact (UNGC) that promotes international principles and best practices on sustainable development. Sustainability Reporting is one such best practice. Sustainability Reporting is imperative for good governance and organisations are now expected to support sustainability issues, risks and performance in a balanced and reasonable way. The United Nations and other global bodies have been in the vanguard in promoting guidelines for sustainability reporting with the Global Reporting Initiative (GRI) being the most Prominent Sustainability reporting guideline. The South African Higher Education Institutions generate a number of reports in the course of any given academic year. As has been the case in the global corporate world, failures in governance in some South African universities point to weaknesses in their governance, especially when it comes to oversight of the operations of institutions. Considering this, it is important to critically examine strategic planning processes to understand the aspects that are important for the survival of Higher Education Institutions (HEIs) and therefore they should be regularly and closely monitored. The study begins by exploring literature relating to strategic planning, governance, sustainability reporting practices and Business Intelligence (BI) technologies in Higher Education. The primary objective of the investigation is to propose a sustainability reporting framework for Higher Education Institutions in South Africa. It is argued that with the aid of appropriate BI tools, the proposed Sustainability Reporting framework would be useful in tracking progress in the implementation of strategic plans and at the same time strengthen governance in institutions. The study identified elements of Sustainability Reporting that are important for strategic planning. To develop the proposed framework, an empirical investigation was undertaken. Four online questionnaires were completed and returned by 108 participants comprising of Registrars and Information Managers at 23 South African Higher Education Institutions as well as to Information Managers in selected International Higher Education Institutions and Managers at the Nelson Mandela Metropolitan University (NMMU). The online questionnaires were developed to elicit information to include in the proposed framework. To analyse results, both descriptive and inferential statistics such as Analysis of Variance (ANOVA) were used. Results from the surveys revealed that Higher Education Institutions globally and in South Africa are grappling with the same issues. When it comes to Sustainability Reporting, factors such as information culture and Business Intelligence maturity levels were not found to be very different among the various institutions. In the case study at NMMU, correlational analysis confirmed that variables such as Management buying and the availability of BI reports were positively related to effective strategic planning and vice versa. Similarly, a strong correlation was observed between reporting guidelines and strategic planning. Moreover, the study highlighted the critical role of management and leadership in a university in creating an environment that supports Sustainability Reporting. In conclusion, it was recommended that efforts should be directed at creating awareness and at training staff on aspects that promote sustainability. It is incumbent upon the institution to take advantage of and promote technological tools and techniques to enable the easy flow of data and information in understandable and usable formats to all its stakeholders. Finally, a Framework for Sustainability Reporting for Higher Education Institutions (FSRHEI) and guidelines for implementing Sustainability Reports are proposed.
- Full Text:
- Date Issued: 2014
- Authors: Bosire, Samuel Mobisa
- Date: 2014
- Subjects: Sustainable development reporting -- South Africa , Business intelligence -- South Africa , Universities and colleges -- South Africa , Corporate governance -- South Africa
- Language: English
- Type: Thesis , Doctoral , DBA
- Identifier: vital:8798 , http://hdl.handle.net/10948/d1016126
- Description: Sustainability has gained prominence globally among nations, regions and organisations as a result of factors such as the effects of climate change on the environment, diminishing natural resources and rising population growth with their concomitant impact on economies and social systems. South Africa is a signatory to the United Nations Global Compact (UNGC) that promotes international principles and best practices on sustainable development. Sustainability Reporting is one such best practice. Sustainability Reporting is imperative for good governance and organisations are now expected to support sustainability issues, risks and performance in a balanced and reasonable way. The United Nations and other global bodies have been in the vanguard in promoting guidelines for sustainability reporting with the Global Reporting Initiative (GRI) being the most Prominent Sustainability reporting guideline. The South African Higher Education Institutions generate a number of reports in the course of any given academic year. As has been the case in the global corporate world, failures in governance in some South African universities point to weaknesses in their governance, especially when it comes to oversight of the operations of institutions. Considering this, it is important to critically examine strategic planning processes to understand the aspects that are important for the survival of Higher Education Institutions (HEIs) and therefore they should be regularly and closely monitored. The study begins by exploring literature relating to strategic planning, governance, sustainability reporting practices and Business Intelligence (BI) technologies in Higher Education. The primary objective of the investigation is to propose a sustainability reporting framework for Higher Education Institutions in South Africa. It is argued that with the aid of appropriate BI tools, the proposed Sustainability Reporting framework would be useful in tracking progress in the implementation of strategic plans and at the same time strengthen governance in institutions. The study identified elements of Sustainability Reporting that are important for strategic planning. To develop the proposed framework, an empirical investigation was undertaken. Four online questionnaires were completed and returned by 108 participants comprising of Registrars and Information Managers at 23 South African Higher Education Institutions as well as to Information Managers in selected International Higher Education Institutions and Managers at the Nelson Mandela Metropolitan University (NMMU). The online questionnaires were developed to elicit information to include in the proposed framework. To analyse results, both descriptive and inferential statistics such as Analysis of Variance (ANOVA) were used. Results from the surveys revealed that Higher Education Institutions globally and in South Africa are grappling with the same issues. When it comes to Sustainability Reporting, factors such as information culture and Business Intelligence maturity levels were not found to be very different among the various institutions. In the case study at NMMU, correlational analysis confirmed that variables such as Management buying and the availability of BI reports were positively related to effective strategic planning and vice versa. Similarly, a strong correlation was observed between reporting guidelines and strategic planning. Moreover, the study highlighted the critical role of management and leadership in a university in creating an environment that supports Sustainability Reporting. In conclusion, it was recommended that efforts should be directed at creating awareness and at training staff on aspects that promote sustainability. It is incumbent upon the institution to take advantage of and promote technological tools and techniques to enable the easy flow of data and information in understandable and usable formats to all its stakeholders. Finally, a Framework for Sustainability Reporting for Higher Education Institutions (FSRHEI) and guidelines for implementing Sustainability Reports are proposed.
- Full Text:
- Date Issued: 2014
A virtual-community-centric model for coordination in the South African public sector
- Thomas, Godwin Dogara Ayenajeh
- Authors: Thomas, Godwin Dogara Ayenajeh
- Date: 2014
- Subjects: Electronic data processing -- Distributed processing , Interprofessional relations , Virtual work teams
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9831 , http://hdl.handle.net/10948/d1021073
- Description: Organizations face challenges constantly owing to limited resources. As such, to take advantage of new opportunities and to mitigate possible risks they look for new ways to collaborate, by sharing knowledge and competencies. Coordination among partners is critical in order to achieve success. The segmented South African public sector is no different. Driven by the desire to ensure proper service delivery in this sector, various government bodies and service providers play different roles towards the attainment of common goals. This is easier said than done, given the complexity of the distributed nature of the environment. Heterogeneity, autonomy, and the increasing need to collaborate provoke the need to develop an integrative and dynamic coordination support service system in the SA public sector. Thus, the research looks to theories/concepts and existing coordination practices to ground the process of development. To inform the design of the proposed artefact the research employs an interdisciplinary approach championed by coordination theory to review coordination-related theories and concepts. The effort accounts for coordination constructs that characterize and transform the problem and solution spaces. Thus, requirements are explicit towards identifying coordination breakdowns and their resolution. Furthermore, how coordination in a distributed environment is supported in practice is considered from a socio-technical perspective in an effort to account holistically for coordination support. Examining existing solutions identified shortcomings that, if addressed, can help to improve the solutions for coordination, which are often rigidly and narrowly defined. The research argues that introducing a mediating technological artefact conceived from a virtual community and service lenses can serve as a solution to the problem. By adopting a design-science research paradigm, the research develops a model as a primary artefact to support coordination from a collaboration standpoint. The suggestions from theory and practice and the unique case requirement identified through a novel case analysis framework form the basis of the model design. The proposed model support operation calls for an architecture which employs a design pattern that divides a complex whole into smaller, simpler parts, with the aim of reducing the system complexity. Four fundamental functions of the supporting architecture are introduced and discussed as they would support the operation and activities of the proposed collaboration lifecycle model geared towards streamlining coordination in a distributed environment. As part of the model development knowledge contributions are made in several ways. Firstly, an analytical instrument is presented that can be used by an enterprise architect or business analyst to study the coordination status quo of a collaborative activity in a distributed environment. Secondly, a lifecycle model is presented as meta-process model with activities that are geared towards streamlining the coordination of dynamic collaborative activities or projects. Thirdly, an architecture that will enable the technical virtual community-centric, context-aware environment that hosts the process-based operations is offered. Finally, the validation tool that represents the applied contribution to the research that promises possible adaptation for similar circumstances is presented. The artefacts contribute towards a design theory in IS research for the development and improvement of coordination support services in a distributed environment such as the South African public sector.
- Full Text:
- Date Issued: 2014
- Authors: Thomas, Godwin Dogara Ayenajeh
- Date: 2014
- Subjects: Electronic data processing -- Distributed processing , Interprofessional relations , Virtual work teams
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9831 , http://hdl.handle.net/10948/d1021073
- Description: Organizations face challenges constantly owing to limited resources. As such, to take advantage of new opportunities and to mitigate possible risks they look for new ways to collaborate, by sharing knowledge and competencies. Coordination among partners is critical in order to achieve success. The segmented South African public sector is no different. Driven by the desire to ensure proper service delivery in this sector, various government bodies and service providers play different roles towards the attainment of common goals. This is easier said than done, given the complexity of the distributed nature of the environment. Heterogeneity, autonomy, and the increasing need to collaborate provoke the need to develop an integrative and dynamic coordination support service system in the SA public sector. Thus, the research looks to theories/concepts and existing coordination practices to ground the process of development. To inform the design of the proposed artefact the research employs an interdisciplinary approach championed by coordination theory to review coordination-related theories and concepts. The effort accounts for coordination constructs that characterize and transform the problem and solution spaces. Thus, requirements are explicit towards identifying coordination breakdowns and their resolution. Furthermore, how coordination in a distributed environment is supported in practice is considered from a socio-technical perspective in an effort to account holistically for coordination support. Examining existing solutions identified shortcomings that, if addressed, can help to improve the solutions for coordination, which are often rigidly and narrowly defined. The research argues that introducing a mediating technological artefact conceived from a virtual community and service lenses can serve as a solution to the problem. By adopting a design-science research paradigm, the research develops a model as a primary artefact to support coordination from a collaboration standpoint. The suggestions from theory and practice and the unique case requirement identified through a novel case analysis framework form the basis of the model design. The proposed model support operation calls for an architecture which employs a design pattern that divides a complex whole into smaller, simpler parts, with the aim of reducing the system complexity. Four fundamental functions of the supporting architecture are introduced and discussed as they would support the operation and activities of the proposed collaboration lifecycle model geared towards streamlining coordination in a distributed environment. As part of the model development knowledge contributions are made in several ways. Firstly, an analytical instrument is presented that can be used by an enterprise architect or business analyst to study the coordination status quo of a collaborative activity in a distributed environment. Secondly, a lifecycle model is presented as meta-process model with activities that are geared towards streamlining the coordination of dynamic collaborative activities or projects. Thirdly, an architecture that will enable the technical virtual community-centric, context-aware environment that hosts the process-based operations is offered. Finally, the validation tool that represents the applied contribution to the research that promises possible adaptation for similar circumstances is presented. The artefacts contribute towards a design theory in IS research for the development and improvement of coordination support services in a distributed environment such as the South African public sector.
- Full Text:
- Date Issued: 2014
Adherence to antiretroviral therapy in children in Zimbabwe: a randomized control trial to validate a new self-reported adherence monitoring tool
- Authors: Mugore, Linnetie
- Date: 2014
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54734 , vital:26607
- Description: Background: Among children taking antiretroviral therapy (ART), self-reports have been widely reported to over-estimate adherence levels. Pill count adherence levels are often lower than self-reported levels, with unannounced home pill count adherence being lower than facility based pill count adherence. There is often poor agreement between pill count adherence levels and those measured using other objective adherence measuring methods such as Medication Event Monitoring Systems (MEMS®), which is widely viewed as the gold standard for adherence measurement. Objectives: The aim of this study was to design and evaluate a new self-reported paediatric adherence monitoring tool, assess the feasibility of using pill count methods in monitoring adherence and identify challenges to reporting adherence among children on ART in rural and urban Zimbabwe. Methods A dual centre, superiority, parallel design RCT was conducted to evaluate the newly-developed visually- and verbally-cued „past 10 days‟ tool for the assessment of adherence in children on ART at two sites in Zimbabwe; Harare Central Children‟s Hospital in an urban setting, and Murambinda Mission Hospital, a rural site. Child-caregiver pairs presenting to one of these facilities for the child‟s review of ART and refill of the medication were recruited, signed informed consent obtained, and were randomised for self-reported adherence monitoring into either the experimental group („new 10-day tool‟) or the control group („PACTG-style‟ self-report tool). Data (demographic, socioeconomic, and reported adherence) were collected in individual interviews with child-caregiver pairs. Additional adherence monitoring methods used for both groups included the Morisky-8-Item Medication Adherence Scale (MMAS-8) and a facility based pill count. FGDs were held with groups of caregivers and groups of children ≥13 years of age to understand reasons for non-adherence as well as issues around reporting non-adherence. Superiority testing was conducted by comparing adherent proportions and their confidence intervals (95% CI). Further concurrent validity test was done using the Mann-Whitney U test to evaluate the relationship between the new tool and the MMAS-8 scores. Agreement between the child and caregiver reports of adherence was used as a test of reliability of the new tool using the kappa statistic. Socio-demographic, clinical and care-related factors associated with adherence were identified using reported adherence in both child and caregiver groups in a logistic regression model. Two pill count methods were assessed for feasibility using the proportions of children with complete data for calculating adherence levels, and their CI and a comparison of the two methods, a routinely-used method and one that incorporated the reported residual quantity (RRQ) of medication at last refill. Results : Analysis included 245 child-caregiver pairs, 123 in the experimental group and 122 in the control group. The median age for children was 9 years. In the experimental group, adherence by caregiver and child reports ranged from 94.3% - 98.4% and 78.4% - 96.1%, and those in the control group ranged from 89.2% - 97.5% and 71.2% - 98.1%, respectively. There was no significant difference between adherence levels in the two groups. Adherence levels measured by both the experimental and control tools were found to be associated with MMAS-8 adherence levels (p <0.05). Agreement between child- and caregiver-reported adherence was moderate though significant (kappa; 0.407, p <0.05). Only about half of the children had adequate data to compute pill counts. Proportions adherent at 95% cut-off were 39% by the „routine pill count‟ and 58% by the „Pill count RRQ‟. Being an orphan was associated with child reported-adherence whereas use of non-human reminders, having a maternal relative as a primary caregiver and knowledge of dose frequency, were all associated with caregiver-reported adherence. Major causes of non-adherence mentioned during the FGDs included interference of medication administration times with scheduling of routine socio-economic activities and lack of support from some non-biological caregivers. Reporting of non-adherence appeared to be hampered by perceptions of negative reactions by healthcare workers to these reports and by caregivers being unaware that the child missed some doses. Conclusions: The „new 10-day tool‟ was not shown to be superior to the „PACTG-style tool‟ in detecting non-adherence, however this new tool was found to be a valid and reliable adherence monitoring tool that included a moderately long recall period of 10 days, can be applied without the need for the respondent to remember names of individual medicines in the
- Full Text:
- Date Issued: 2014
- Authors: Mugore, Linnetie
- Date: 2014
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54734 , vital:26607
- Description: Background: Among children taking antiretroviral therapy (ART), self-reports have been widely reported to over-estimate adherence levels. Pill count adherence levels are often lower than self-reported levels, with unannounced home pill count adherence being lower than facility based pill count adherence. There is often poor agreement between pill count adherence levels and those measured using other objective adherence measuring methods such as Medication Event Monitoring Systems (MEMS®), which is widely viewed as the gold standard for adherence measurement. Objectives: The aim of this study was to design and evaluate a new self-reported paediatric adherence monitoring tool, assess the feasibility of using pill count methods in monitoring adherence and identify challenges to reporting adherence among children on ART in rural and urban Zimbabwe. Methods A dual centre, superiority, parallel design RCT was conducted to evaluate the newly-developed visually- and verbally-cued „past 10 days‟ tool for the assessment of adherence in children on ART at two sites in Zimbabwe; Harare Central Children‟s Hospital in an urban setting, and Murambinda Mission Hospital, a rural site. Child-caregiver pairs presenting to one of these facilities for the child‟s review of ART and refill of the medication were recruited, signed informed consent obtained, and were randomised for self-reported adherence monitoring into either the experimental group („new 10-day tool‟) or the control group („PACTG-style‟ self-report tool). Data (demographic, socioeconomic, and reported adherence) were collected in individual interviews with child-caregiver pairs. Additional adherence monitoring methods used for both groups included the Morisky-8-Item Medication Adherence Scale (MMAS-8) and a facility based pill count. FGDs were held with groups of caregivers and groups of children ≥13 years of age to understand reasons for non-adherence as well as issues around reporting non-adherence. Superiority testing was conducted by comparing adherent proportions and their confidence intervals (95% CI). Further concurrent validity test was done using the Mann-Whitney U test to evaluate the relationship between the new tool and the MMAS-8 scores. Agreement between the child and caregiver reports of adherence was used as a test of reliability of the new tool using the kappa statistic. Socio-demographic, clinical and care-related factors associated with adherence were identified using reported adherence in both child and caregiver groups in a logistic regression model. Two pill count methods were assessed for feasibility using the proportions of children with complete data for calculating adherence levels, and their CI and a comparison of the two methods, a routinely-used method and one that incorporated the reported residual quantity (RRQ) of medication at last refill. Results : Analysis included 245 child-caregiver pairs, 123 in the experimental group and 122 in the control group. The median age for children was 9 years. In the experimental group, adherence by caregiver and child reports ranged from 94.3% - 98.4% and 78.4% - 96.1%, and those in the control group ranged from 89.2% - 97.5% and 71.2% - 98.1%, respectively. There was no significant difference between adherence levels in the two groups. Adherence levels measured by both the experimental and control tools were found to be associated with MMAS-8 adherence levels (p <0.05). Agreement between child- and caregiver-reported adherence was moderate though significant (kappa; 0.407, p <0.05). Only about half of the children had adequate data to compute pill counts. Proportions adherent at 95% cut-off were 39% by the „routine pill count‟ and 58% by the „Pill count RRQ‟. Being an orphan was associated with child reported-adherence whereas use of non-human reminders, having a maternal relative as a primary caregiver and knowledge of dose frequency, were all associated with caregiver-reported adherence. Major causes of non-adherence mentioned during the FGDs included interference of medication administration times with scheduling of routine socio-economic activities and lack of support from some non-biological caregivers. Reporting of non-adherence appeared to be hampered by perceptions of negative reactions by healthcare workers to these reports and by caregivers being unaware that the child missed some doses. Conclusions: The „new 10-day tool‟ was not shown to be superior to the „PACTG-style tool‟ in detecting non-adherence, however this new tool was found to be a valid and reliable adherence monitoring tool that included a moderately long recall period of 10 days, can be applied without the need for the respondent to remember names of individual medicines in the
- Full Text:
- Date Issued: 2014
Aggregate stability, crust formation, steady state infiltration and mode of seedling emergence in soils with various texture and mineralogy
- Authors: Nciizah, Adornis Dakarai
- Date: 2014
- Language: English
- Type: Thesis , Doctoral , PhD (Crop Science)
- Identifier: vital:11871 , http://hdl.handle.net/10353/d1015539
- Description: The general objective of this study was to quantify the interactive effects of soil texture and mineralogy on soil crusting, infiltration and erosion and the subsequent effects on maize seedling emergence and early development using soils collected from 14 ecotopes in the Eastern Cape Province. The specific objectives were to determine; i) particulate organic matter, soil texture and mineralogy relations, ii) aggregate stability and breakdown mechanisms as affected by soil texture and organic matter, iii) crust formation and steady state infiltration, iv) rainfall pattern effects on crusting, infiltration and erodibility and v) rainfall intensity effects on crusting and mode of seedling emergence. Particulate organic matter (POM) was fractionated into litter POM, coarse POM and fine POM. Both total soil organic matter (SOM) and the POM in each fraction were determined using the weight loss on ignition procedure. Most ecotopes were either sandy loam or sandy clay loam and primary minerals especially quartz dominated the soil mineralogy. The clay content was significantly related to the total SOM (r = 0.78), hematite (r = 0.83) and quartz (r = -0.74). Aggregate stability was determined following methods described by Le Bissonnais (1996) i.e. fast wetting (FW), slow wetting (SW) and wet stirring (WSt). Aggregate breakdown followed the order; slaking < mechanical breakdown < micro-cracking for most ecotopes except Lujiko Leeufontein and Amatola Jozini where SW and WSt resulted in the least MWD respectively. Aggregate stability was significantly correlated to POM only for FW and SW and only positive but not significant for WSt. To study crust formation, aggregate sizes <2, 2 to 3, 3 to 5 mm were exposed to 60 mm hr-1 simulated rainfall. Sieving structural crusts, ~0.2 to ~0.8 mm thick with a surface layer of loose grains overlying a thin plasmic layer, formed in all ecotopes. Crusts with strengths between 0.25 and 3.42 10-4 kg m-2 developed on the <2 mm compared to <2.23 10-4 kg m-2 in the >2 mm aggregates. The reverse occurred in Alice Jozini, which had relatively low clay content of 120 g kg-1. Two significantly different groups of the SSIR were observed. The SSIR was between 1.24 and 3.60 mm hr-1 in the group of ecotopes dominated by primary minerals and relatively lower clay content. In the second group, consisting one ecotope dominated by kaolinite and relatively higher clay content, the SSIR was 15.23 mm hr-1. Rainfall pattern i.e. rainfall applied either as an eight minute single rainstorm (SR) or four-two minute intermittent rainstorms (IR) separated by a 48 h drying period significantly (p < 0.05) affected crust strength, SSIR and erosion. The IR resulted in higher crust strength and SSIR than SR. The effect of rainfall pattern on SSIR was mostly influenced by the primary minerals namely, quartz. Three maize seeds of equal size were planted in plastic pots, pre-wetted by capillary action and then subjected to simulated rainfall at three intensities for 5 min. Rainfall intensity (30, 45 and 60 mm h-1) significantly (P < 0.05) affected crust strength and mean emergence day (MED) but not emergence percentage (EMP) and shoot length (P > 0.05). The 60 mm h-1 rainfall intensity resulted in the highest crust strength and MED.
- Full Text:
- Date Issued: 2014
- Authors: Nciizah, Adornis Dakarai
- Date: 2014
- Language: English
- Type: Thesis , Doctoral , PhD (Crop Science)
- Identifier: vital:11871 , http://hdl.handle.net/10353/d1015539
- Description: The general objective of this study was to quantify the interactive effects of soil texture and mineralogy on soil crusting, infiltration and erosion and the subsequent effects on maize seedling emergence and early development using soils collected from 14 ecotopes in the Eastern Cape Province. The specific objectives were to determine; i) particulate organic matter, soil texture and mineralogy relations, ii) aggregate stability and breakdown mechanisms as affected by soil texture and organic matter, iii) crust formation and steady state infiltration, iv) rainfall pattern effects on crusting, infiltration and erodibility and v) rainfall intensity effects on crusting and mode of seedling emergence. Particulate organic matter (POM) was fractionated into litter POM, coarse POM and fine POM. Both total soil organic matter (SOM) and the POM in each fraction were determined using the weight loss on ignition procedure. Most ecotopes were either sandy loam or sandy clay loam and primary minerals especially quartz dominated the soil mineralogy. The clay content was significantly related to the total SOM (r = 0.78), hematite (r = 0.83) and quartz (r = -0.74). Aggregate stability was determined following methods described by Le Bissonnais (1996) i.e. fast wetting (FW), slow wetting (SW) and wet stirring (WSt). Aggregate breakdown followed the order; slaking < mechanical breakdown < micro-cracking for most ecotopes except Lujiko Leeufontein and Amatola Jozini where SW and WSt resulted in the least MWD respectively. Aggregate stability was significantly correlated to POM only for FW and SW and only positive but not significant for WSt. To study crust formation, aggregate sizes <2, 2 to 3, 3 to 5 mm were exposed to 60 mm hr-1 simulated rainfall. Sieving structural crusts, ~0.2 to ~0.8 mm thick with a surface layer of loose grains overlying a thin plasmic layer, formed in all ecotopes. Crusts with strengths between 0.25 and 3.42 10-4 kg m-2 developed on the <2 mm compared to <2.23 10-4 kg m-2 in the >2 mm aggregates. The reverse occurred in Alice Jozini, which had relatively low clay content of 120 g kg-1. Two significantly different groups of the SSIR were observed. The SSIR was between 1.24 and 3.60 mm hr-1 in the group of ecotopes dominated by primary minerals and relatively lower clay content. In the second group, consisting one ecotope dominated by kaolinite and relatively higher clay content, the SSIR was 15.23 mm hr-1. Rainfall pattern i.e. rainfall applied either as an eight minute single rainstorm (SR) or four-two minute intermittent rainstorms (IR) separated by a 48 h drying period significantly (p < 0.05) affected crust strength, SSIR and erosion. The IR resulted in higher crust strength and SSIR than SR. The effect of rainfall pattern on SSIR was mostly influenced by the primary minerals namely, quartz. Three maize seeds of equal size were planted in plastic pots, pre-wetted by capillary action and then subjected to simulated rainfall at three intensities for 5 min. Rainfall intensity (30, 45 and 60 mm h-1) significantly (P < 0.05) affected crust strength and mean emergence day (MED) but not emergence percentage (EMP) and shoot length (P > 0.05). The 60 mm h-1 rainfall intensity resulted in the highest crust strength and MED.
- Full Text:
- Date Issued: 2014
Alternative methods used by small-holder farmers to control ticks and bovine dermatophilosis and the impact of a changing interface of Amblyomma ticks on dermatophilosis in Zimbabwe
- Authors: Ndhkovu, Daud Nyosi
- Date: 2014
- Subjects: Ticks -- Control -- Africa, Southern , Dermatophilosis
- Language: English
- Type: Thesis , Doctoral , PhD (Animal Science)
- Identifier: vital:11830 , http://hdl.handle.net/10353/d1019764 , Ticks -- Control -- Africa, Southern , Dermatophilosis
- Description: This study was carried out to document the ethno-veterinary plants and non-plant remedies that farmers used to control dermatophilosis and ticks, and validate these in vitro and in vivo, as well as determine how the interface of Amblyomma variegatum and A. hebraeum affected the epidemiology of bovine dermatophilosis at selected small-holder areas in North-West Zimbabwe. A structured questionnaire survey was used to collect information on the control methods used by farmers for the control of bovine dermatophilosis and ticks. A total of 39 plants were used by farmers for various diseases, eleven of these plants were used for the control of dermatophilosis while three were for tick control. Across the study sites, dermatophilosis was controlled using eleven plants. Among these plants; six plants; Cissus quadrangularis, Catunaregan spinosa, Pterocarpus angolensis Carica papaya, Manihot esculenta and Blumea decurrens which were frequently used were selected for further studies. In vitro and in vivo studies were conducted to validate the efficacy of these plants. The minimum inhibitory concentration and bactericidal concentration assays were used for the in vitro validation of C. quadrangularis, C. spinosa and P. angolensis. Dermatophilus congolensis was more sensitive to P. angolensis average MIC = 0.63 mg/ml than to C. quadrangularis average MIC = iii 1.25 mg/ml and C. spinosa average MIC = 2.08 mg/ml. Cissus quadrangularis was selected for in vivo studies as this plant was the one most frequently used by farmers. Its therapeutic efficacy was compared to conventional antibiotics that farmers used to treat dermatophilosis infection. In the in vivo trials C. quadrangularis did not lead to appreciable reduction in clinical disease compared to the conventional drugs. The larval packet assay was the in vitro assay used to validate the efficacy of Carica papaya, Manihot esculenta and Blumea decurrens against larvae of A. hebraeum and Rhipicephalus appendiculatus. Manihot esculenta at 20 % w/v exhibited the highest larvicidal activity against R. appendiculatus. In the in vivo study, efficacy of the plants were investigated on naturally tick-infested cattle. Mannihot esculenta exhibited the largest tick load reduction compared to the other two plants but its performance was lower than that of conventional acaricides. The effect of A. variegatum and A. hebraeum on bovine dermatophilosis was investigated by evaluating how the presence or absence of these ticks and other herd level risk factors predicted clinical dermatophilosis and its prevalence at herd level. A structured questionnaire survey was carried out to collect data on potential risk factors. At the same time, cattle were physically examined for the presence of bovine dermatophilosis, according to a pre-defined case definition, and presence or absence of Amblyomma ticks was also recorded. The multivariable binary logistic model was developed with disease status as outcome, tick presence and infestion and herd level risk factors as predictors. Of the herds examined clinical bovine dermatophilosis was detected in 45% (84/185; 95% CI: 38.2, 52.6%) of them. Herds infested with Amblyomma variegatum were associated with higher odds (OR= 6.8; iv 95% CI: 1.71, 27.10) of clinical dermatophilosis while the association was not significant (P > 0.05) in A. hebraeum infested herds. It was concluded that management practices aimed at movement and tick control would help reduce the prevalence of clinical dermatophilosis in herds.
- Full Text:
- Date Issued: 2014
- Authors: Ndhkovu, Daud Nyosi
- Date: 2014
- Subjects: Ticks -- Control -- Africa, Southern , Dermatophilosis
- Language: English
- Type: Thesis , Doctoral , PhD (Animal Science)
- Identifier: vital:11830 , http://hdl.handle.net/10353/d1019764 , Ticks -- Control -- Africa, Southern , Dermatophilosis
- Description: This study was carried out to document the ethno-veterinary plants and non-plant remedies that farmers used to control dermatophilosis and ticks, and validate these in vitro and in vivo, as well as determine how the interface of Amblyomma variegatum and A. hebraeum affected the epidemiology of bovine dermatophilosis at selected small-holder areas in North-West Zimbabwe. A structured questionnaire survey was used to collect information on the control methods used by farmers for the control of bovine dermatophilosis and ticks. A total of 39 plants were used by farmers for various diseases, eleven of these plants were used for the control of dermatophilosis while three were for tick control. Across the study sites, dermatophilosis was controlled using eleven plants. Among these plants; six plants; Cissus quadrangularis, Catunaregan spinosa, Pterocarpus angolensis Carica papaya, Manihot esculenta and Blumea decurrens which were frequently used were selected for further studies. In vitro and in vivo studies were conducted to validate the efficacy of these plants. The minimum inhibitory concentration and bactericidal concentration assays were used for the in vitro validation of C. quadrangularis, C. spinosa and P. angolensis. Dermatophilus congolensis was more sensitive to P. angolensis average MIC = 0.63 mg/ml than to C. quadrangularis average MIC = iii 1.25 mg/ml and C. spinosa average MIC = 2.08 mg/ml. Cissus quadrangularis was selected for in vivo studies as this plant was the one most frequently used by farmers. Its therapeutic efficacy was compared to conventional antibiotics that farmers used to treat dermatophilosis infection. In the in vivo trials C. quadrangularis did not lead to appreciable reduction in clinical disease compared to the conventional drugs. The larval packet assay was the in vitro assay used to validate the efficacy of Carica papaya, Manihot esculenta and Blumea decurrens against larvae of A. hebraeum and Rhipicephalus appendiculatus. Manihot esculenta at 20 % w/v exhibited the highest larvicidal activity against R. appendiculatus. In the in vivo study, efficacy of the plants were investigated on naturally tick-infested cattle. Mannihot esculenta exhibited the largest tick load reduction compared to the other two plants but its performance was lower than that of conventional acaricides. The effect of A. variegatum and A. hebraeum on bovine dermatophilosis was investigated by evaluating how the presence or absence of these ticks and other herd level risk factors predicted clinical dermatophilosis and its prevalence at herd level. A structured questionnaire survey was carried out to collect data on potential risk factors. At the same time, cattle were physically examined for the presence of bovine dermatophilosis, according to a pre-defined case definition, and presence or absence of Amblyomma ticks was also recorded. The multivariable binary logistic model was developed with disease status as outcome, tick presence and infestion and herd level risk factors as predictors. Of the herds examined clinical bovine dermatophilosis was detected in 45% (84/185; 95% CI: 38.2, 52.6%) of them. Herds infested with Amblyomma variegatum were associated with higher odds (OR= 6.8; iv 95% CI: 1.71, 27.10) of clinical dermatophilosis while the association was not significant (P > 0.05) in A. hebraeum infested herds. It was concluded that management practices aimed at movement and tick control would help reduce the prevalence of clinical dermatophilosis in herds.
- Full Text:
- Date Issued: 2014
An analysis of the relationship between bank efficiency and access to banking services in South Africa
- Authors: Maredza, Andrew
- Date: 2014
- Language: English
- Type: Thesis , Doctoral , Doctor of Administration (in Public Administration)
- Identifier: http://hdl.handle.net/10353/910 , vital:26508
- Description: The primary objective of this study is to investigate the nature of the relationship between bank efficiency gains and access to banking services in South Africa. The importance of making such an enquiry arises from the fact that various studies have identified access to financial services as an important vehicle for lifting the poor out of poverty. In particular, there is concern that banks` appetite for better scores on efficiency has the potential of reducing access to services for consumers particularly the low-income clients. The study attempted to answer two central research questions: Firstly, does the quest for banks to improve efficiency preclude access to banking services for some group of consumers? Secondly, do bank efficiency gains necessarily translate to improved accessibility to banking services? The researcher applied a two-stage methodology approach. In the first stage, the Hicks-Moorsteen aggregator functions were used to generate and decompose total factor productivity (TFP) into several efficiency measures for a panel of eight South African banks. First stage results revealed that the average banking sector total factor productivity efficiency (TFPE) was 59 percent implying that the observed TFP was 41 percent short of the maximum TFP possible using the available technology. A further comparison of performance revealed that large banks were better performing than small banks in terms of TFPE. Apart from estimating and decomposing TFP indices we needed to determine if there was a statistically significant change in the TFPE of South African banking system as a result of the global financial crisis. A general analysis of the generated scores showed that TFPE clearly decreased during 2008-2009, the period that coincided with the global financial crisis. We then used the Fixed Effects Model (FEM) in the second-stage analysis to examine the link between banking sector TFPE and access. The FEM was utilised to take account of bankspecific heterogeneity. The obtained results indicated existence of a positive and significant relationship between banking efficiency and access to banking services. This study suggests that banking sector efficiency plays a crucial role in promoting access to bank services in South Africa. We therefore underscore the need for all banks to attain and maintain high efficiency in order to augment government efforts towards improving accessibility for the unbanked South African people. We also found evidence similar to that reached by Kablan (2010) that an increase in the rural population is associated with a reduction in access to bank services. From this result, we speculated that banks are somewhat biased against providing their services to the general rural populace. Since the rural-population variable exerted the greatest marginal impact on access we suggested that perhaps investment in rural infrastructure would help broaden access and so improve financial inclusion on a larger scale. Finally we also investigated the link between banking sector efficiency and unemployment in South Africa. Of paramount importance in the second stage analysis was that we found a negative and significant association between banking sector efficiency and unemployment indicating that employment is influenced, inter alia, by the efficiency with which banks operate.
- Full Text:
- Date Issued: 2014
- Authors: Maredza, Andrew
- Date: 2014
- Language: English
- Type: Thesis , Doctoral , Doctor of Administration (in Public Administration)
- Identifier: http://hdl.handle.net/10353/910 , vital:26508
- Description: The primary objective of this study is to investigate the nature of the relationship between bank efficiency gains and access to banking services in South Africa. The importance of making such an enquiry arises from the fact that various studies have identified access to financial services as an important vehicle for lifting the poor out of poverty. In particular, there is concern that banks` appetite for better scores on efficiency has the potential of reducing access to services for consumers particularly the low-income clients. The study attempted to answer two central research questions: Firstly, does the quest for banks to improve efficiency preclude access to banking services for some group of consumers? Secondly, do bank efficiency gains necessarily translate to improved accessibility to banking services? The researcher applied a two-stage methodology approach. In the first stage, the Hicks-Moorsteen aggregator functions were used to generate and decompose total factor productivity (TFP) into several efficiency measures for a panel of eight South African banks. First stage results revealed that the average banking sector total factor productivity efficiency (TFPE) was 59 percent implying that the observed TFP was 41 percent short of the maximum TFP possible using the available technology. A further comparison of performance revealed that large banks were better performing than small banks in terms of TFPE. Apart from estimating and decomposing TFP indices we needed to determine if there was a statistically significant change in the TFPE of South African banking system as a result of the global financial crisis. A general analysis of the generated scores showed that TFPE clearly decreased during 2008-2009, the period that coincided with the global financial crisis. We then used the Fixed Effects Model (FEM) in the second-stage analysis to examine the link between banking sector TFPE and access. The FEM was utilised to take account of bankspecific heterogeneity. The obtained results indicated existence of a positive and significant relationship between banking efficiency and access to banking services. This study suggests that banking sector efficiency plays a crucial role in promoting access to bank services in South Africa. We therefore underscore the need for all banks to attain and maintain high efficiency in order to augment government efforts towards improving accessibility for the unbanked South African people. We also found evidence similar to that reached by Kablan (2010) that an increase in the rural population is associated with a reduction in access to bank services. From this result, we speculated that banks are somewhat biased against providing their services to the general rural populace. Since the rural-population variable exerted the greatest marginal impact on access we suggested that perhaps investment in rural infrastructure would help broaden access and so improve financial inclusion on a larger scale. Finally we also investigated the link between banking sector efficiency and unemployment in South Africa. Of paramount importance in the second stage analysis was that we found a negative and significant association between banking sector efficiency and unemployment indicating that employment is influenced, inter alia, by the efficiency with which banks operate.
- Full Text:
- Date Issued: 2014
An evaluation of macroinvertebrate-based biomonitoring and ecotoxicological assessments of deteriorating environmental water quality in the Swartkops River, South Africa
- Authors: Odume, Oghenekaro Nelson
- Date: 2014
- Subjects: Water -- Pollution -- South Africa -- Swartkops River , Water quality biological assessment -- South Africa -- Swartkops River , Environmental toxicology -- South Africa -- Swartkops River , Environmental monitoring -- South Africa -- Swartkops River , Aquatic invertebrates -- Effect of water pollution on -- South Africa -- Swartkops River , Chironomidae -- Effect of water pollution on -- South Africa -- Swartkops River , Freshwater ecology -- South Africa -- Swartkops River
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:6046 , http://hdl.handle.net/10962/d1013156
- Description: Freshwater resources are increasingly subject to pollution because of escalating human population growth, accompanied by urbanisation, industrialisation, and the increased demand for food. Consequently, freshwater quality, and aquatic ecosystem structure and function have been severely impaired. The Swartkops River, which drains an urbanised and industrialised catchment in the Eastern Cape of South Africa, is no exception. An integrated environmental water quality (EWQ) approach is needed to measure the impacts of deteriorating water quality on its aquatic ecosystem structure and function to sustain these vital ecosystem-attributes. In this study, an integrated EWQ approach, which included i) analysis of water physico-chemical variables; ii) macroinvertebrate-based family-level taxonomic- and traits-based community analysis; iii) Chironomidae species-level taxonomic- and traits-based community analysis; iv) Chironomidae deformity-based sub-lethal analysis; and v) experimental investigation of long-term wastewater effluent effects, using model stream ecosystems, were applied to investigate environmental water quality in the Swartkops River. One upstream reference site and three downstream sites in the Swartkops River were monitored over a period of three years (August 2009 – September 2012). The family-level taxonomic community responses based on the South African Scoring System version 5 (SASS5) and a newly developed Swartkops multimetric index indicated very poor river health conditions for the three downstream sites, compared with the good condition of the upstream site. The Chironomidae species-level responses in the three downstream sites provided evidence of differences in biotic impairments, which were not evident with the family-level taxonomic data at these sites, thus highlighting the importance of species identification in freshwater biomonitoring. The family-level traits-based approach (TBA) showed that macroinvertebrates with gills and lungs were more abundant at the upstream site, decreasing markedly at the downstream sites. The relative abundance of macroinvertebrates relying on aerial and tegument respiration increased at the downstream sites compared with the upstream sites. The results of the family-level TBA highlighted the inextricable link between the traits-based approach (TBA) and taxonomic identification, clearly showing that the TBA is additional to, and not an alternative to, taxonomic recognition because important traits, e.g. reproductive cannot be used at a coarse taxonomic identification. A novel chironomid species traits-based functional strategies approach developed in this study, based on species combining similar sets of traits, proved sensitive in diagnosing the main abiotic water physico-chemical stressors. The functional traits responded predictably to deteriorating water quality and provided an adaptive and mechanistic basis for interpreting chironomid species occurrences at the four sampling sites, providing insight into why certain chironomid species occurred at one site but not at the other. Chironomid deformities provided evidence of sub-lethal in-stream biological response to deteriorating water quality. A newly developed deformity-based extended toxic score index proved sensitive, enabling the discrimination of the sampling sites, indicating that a biomonitoring tool based on sub-lethal effects could be used to assess the effects of deteriorating water quality before it reached lethal levels. Empirical evidence based on the taxonomic, traits and sub-lethal responses suggested that the changes in macroinvertebrate community structure were caused chiefly by the discharge of wastewater effluents into the river. This was supported by the model-stream ecosystem results indicating significant effects of effluents on the macroinvertebrate community structure, similar to the observed in-stream responses. The model stream results indicated that improved physico-chemical effluent quality compliance after 50% effluent dilution did not significantly reduce the effects of the effluent on the macroinvertebrate communities, showing that ecologically-based methods rather than physico-chemical measures alone are necessary to assess effluent quality. Finally, the results of the multi-criteria approach were integrated to propose tools to manage environmental water quality in the Swartkops River, and the benefits of the study were highlighted in the context of biomonitoring in South Africa.
- Full Text:
- Date Issued: 2014
- Authors: Odume, Oghenekaro Nelson
- Date: 2014
- Subjects: Water -- Pollution -- South Africa -- Swartkops River , Water quality biological assessment -- South Africa -- Swartkops River , Environmental toxicology -- South Africa -- Swartkops River , Environmental monitoring -- South Africa -- Swartkops River , Aquatic invertebrates -- Effect of water pollution on -- South Africa -- Swartkops River , Chironomidae -- Effect of water pollution on -- South Africa -- Swartkops River , Freshwater ecology -- South Africa -- Swartkops River
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:6046 , http://hdl.handle.net/10962/d1013156
- Description: Freshwater resources are increasingly subject to pollution because of escalating human population growth, accompanied by urbanisation, industrialisation, and the increased demand for food. Consequently, freshwater quality, and aquatic ecosystem structure and function have been severely impaired. The Swartkops River, which drains an urbanised and industrialised catchment in the Eastern Cape of South Africa, is no exception. An integrated environmental water quality (EWQ) approach is needed to measure the impacts of deteriorating water quality on its aquatic ecosystem structure and function to sustain these vital ecosystem-attributes. In this study, an integrated EWQ approach, which included i) analysis of water physico-chemical variables; ii) macroinvertebrate-based family-level taxonomic- and traits-based community analysis; iii) Chironomidae species-level taxonomic- and traits-based community analysis; iv) Chironomidae deformity-based sub-lethal analysis; and v) experimental investigation of long-term wastewater effluent effects, using model stream ecosystems, were applied to investigate environmental water quality in the Swartkops River. One upstream reference site and three downstream sites in the Swartkops River were monitored over a period of three years (August 2009 – September 2012). The family-level taxonomic community responses based on the South African Scoring System version 5 (SASS5) and a newly developed Swartkops multimetric index indicated very poor river health conditions for the three downstream sites, compared with the good condition of the upstream site. The Chironomidae species-level responses in the three downstream sites provided evidence of differences in biotic impairments, which were not evident with the family-level taxonomic data at these sites, thus highlighting the importance of species identification in freshwater biomonitoring. The family-level traits-based approach (TBA) showed that macroinvertebrates with gills and lungs were more abundant at the upstream site, decreasing markedly at the downstream sites. The relative abundance of macroinvertebrates relying on aerial and tegument respiration increased at the downstream sites compared with the upstream sites. The results of the family-level TBA highlighted the inextricable link between the traits-based approach (TBA) and taxonomic identification, clearly showing that the TBA is additional to, and not an alternative to, taxonomic recognition because important traits, e.g. reproductive cannot be used at a coarse taxonomic identification. A novel chironomid species traits-based functional strategies approach developed in this study, based on species combining similar sets of traits, proved sensitive in diagnosing the main abiotic water physico-chemical stressors. The functional traits responded predictably to deteriorating water quality and provided an adaptive and mechanistic basis for interpreting chironomid species occurrences at the four sampling sites, providing insight into why certain chironomid species occurred at one site but not at the other. Chironomid deformities provided evidence of sub-lethal in-stream biological response to deteriorating water quality. A newly developed deformity-based extended toxic score index proved sensitive, enabling the discrimination of the sampling sites, indicating that a biomonitoring tool based on sub-lethal effects could be used to assess the effects of deteriorating water quality before it reached lethal levels. Empirical evidence based on the taxonomic, traits and sub-lethal responses suggested that the changes in macroinvertebrate community structure were caused chiefly by the discharge of wastewater effluents into the river. This was supported by the model-stream ecosystem results indicating significant effects of effluents on the macroinvertebrate community structure, similar to the observed in-stream responses. The model stream results indicated that improved physico-chemical effluent quality compliance after 50% effluent dilution did not significantly reduce the effects of the effluent on the macroinvertebrate communities, showing that ecologically-based methods rather than physico-chemical measures alone are necessary to assess effluent quality. Finally, the results of the multi-criteria approach were integrated to propose tools to manage environmental water quality in the Swartkops River, and the benefits of the study were highlighted in the context of biomonitoring in South Africa.
- Full Text:
- Date Issued: 2014