Control and vulnerability : reflections on the nature of human agency and personhood
- Authors: Paphitis, Sharli Anne
- Date: 2015
- Subjects: Self-control , Vulnerability (Personality trait) , Self (Philosophy) , Social psychology , Cognitive science , Frankfurt, Harry G., 1929- -- Criticism and interpretation , Watson, Gary, 1943- -- Criticism and interpretation , Mele, Alfred R., 1951- -- Criticism and interpretation , Nietzsche, Friedrich Wilhelm, 1844-1900 -- Criticism and interpretation
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2750 , http://hdl.handle.net/10962/d1018671
- Description: Following the writings of philosophers such as Harry Frankfurt, Gary Watson, and Alfred Mele, in this thesis I defend some central claims of the self-control view of human agency. However, I not only defend, but also supplement this view in the following two ways. First, drawing on work by Mary Midgley and Sigmund Freud I advance the claim that self-control requires the experience of internal conflict between an agent’s motivations and intentions. Second, drawing on insights from Simone de Beauvoir and Friedrich Nietzsche, as well as recent research in social psychology and cognitive science, I will argue in this thesis that self-control and vulnerability are inextricably intertwined with one another, and that as a result both are to be seen as constitutive of human agency. While it is the capacity for self-control that marks us out as human agents, I argue that it is also our uniquely human vulnerability which distinguishes our agency from the kind of agency which we might attribute to other potential or actual forms of sentience. Further, while the concepts of human agency and personhood are typically conflated in the analytic tradition of philosophy, in this thesis I will show that there are good reasons for understanding these two concepts as subtly distinct from one another. The term personhood, I will argue, can fruitfully be understood in substantive rather than purely formal terms. A person, in the superlative sense, is to be understood as someone who exercises their agency well; and, as such, persons are answerable to a number of normative prescriptions. Following Midgley, Nietzsche and Martha Nussbaum, I argue against Frankfurt’s normative prescription for personhood in the form of what he calls ‘wholeheartedness’, and offer four normative prescriptions for personhood of my own.
- Full Text:
- Authors: Paphitis, Sharli Anne
- Date: 2015
- Subjects: Self-control , Vulnerability (Personality trait) , Self (Philosophy) , Social psychology , Cognitive science , Frankfurt, Harry G., 1929- -- Criticism and interpretation , Watson, Gary, 1943- -- Criticism and interpretation , Mele, Alfred R., 1951- -- Criticism and interpretation , Nietzsche, Friedrich Wilhelm, 1844-1900 -- Criticism and interpretation
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2750 , http://hdl.handle.net/10962/d1018671
- Description: Following the writings of philosophers such as Harry Frankfurt, Gary Watson, and Alfred Mele, in this thesis I defend some central claims of the self-control view of human agency. However, I not only defend, but also supplement this view in the following two ways. First, drawing on work by Mary Midgley and Sigmund Freud I advance the claim that self-control requires the experience of internal conflict between an agent’s motivations and intentions. Second, drawing on insights from Simone de Beauvoir and Friedrich Nietzsche, as well as recent research in social psychology and cognitive science, I will argue in this thesis that self-control and vulnerability are inextricably intertwined with one another, and that as a result both are to be seen as constitutive of human agency. While it is the capacity for self-control that marks us out as human agents, I argue that it is also our uniquely human vulnerability which distinguishes our agency from the kind of agency which we might attribute to other potential or actual forms of sentience. Further, while the concepts of human agency and personhood are typically conflated in the analytic tradition of philosophy, in this thesis I will show that there are good reasons for understanding these two concepts as subtly distinct from one another. The term personhood, I will argue, can fruitfully be understood in substantive rather than purely formal terms. A person, in the superlative sense, is to be understood as someone who exercises their agency well; and, as such, persons are answerable to a number of normative prescriptions. Following Midgley, Nietzsche and Martha Nussbaum, I argue against Frankfurt’s normative prescription for personhood in the form of what he calls ‘wholeheartedness’, and offer four normative prescriptions for personhood of my own.
- Full Text:
Counsellors’ talk about their understanding of, and practices in response to, intimate partner violence during pregnancy: a narrative-discursive analytic study.
- Authors: Fleischack, Anne
- Date: 2015
- Subjects: Intimate partner violence -- South Africa , Intimate partner violence -- Psychological aspects , Abused women -- Counseling of , Pregnant women -- South Africa -- Abuse of , Pregnant women -- Counseling of
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3255 , http://hdl.handle.net/10962/d1016391
- Description: South Africa is a very violent society, where violence is often used as a social resource to maintain control and establish authority. Global and local research suggests that there is a high prevalence of intimate partner violence (IPV), a facet of this violence, although little research has been conducted into the effects of IPV during pregnancy in the South African non-governmental organisation (NGO) context. NGOs globally and in South Africa have attempted to address IPV and IPV during pregnancy by providing services that aim to assist (largely female) clients emotionally and logistically. In light of this phenomenon, this qualitative study presents data generated through the use of a lightly-structured narrative interview schedule. The interviews were conducted over three sessions with eight counsellors, all based at two NGOs in South Africa and experienced in counselling women who have suffered IPV and IPV during pregnancy. This study used Taylor and Littleton’s (2006) narrative-discursive analytical lens, infused with theoretical insights from Foucault about power, discourse and narrative in order to identify the discursive resources that shape the narratives that the counsellors shared in the interviews and how these translate into subject positions and (gendered) power relations of the men and women about whom they speak. Six discursive resources emerged from the narratives, namely a discourse of ‘traditional “African” culture’, ‘patriarchal masculinity’, ‘nurturing femininity’, ‘female victimhood’, ‘female survivorhood’ and ‘human rights’. These informed the three main narratives that emerged: narratives about IPV in general, IPV during pregnancy, and the counsellors’ narratives about their intervention strategies. Within these narratives (and the micro-narratives which comprised them), men were largely positioned as subscribing to violent patriarchal behaviour whilst women were mostly positioned as nurturing and victims of this violence. The counsellors also constructed women as largely ignorant of their options about IPV and IPV during pregnancy; they constructed these phenomena as problems that require intervention and identified a number of factors that indicate what successful IPV interventions should entail. In reflecting upon this analysis, this study also aimed to address the questions of what is achieved or gained by using these narratives and discursive resources, what the significance or consequences are of constructing and using these particular narratives and discourses and whether different narratives or discourses would have been possible. Recommendations for further research includes incorporating more sites as well as interviewing perpetrators and IPV survivors themselves, perhaps in their home language where relevant rather than English, to gain a broader and more faceted understanding of the dynamics surrounding IPV during pregnancy. A recommendation for practice in intervention against IPV during pregnancy is to introduce more holistic/systemic intervention strategies and working with communities to address this issue.
- Full Text:
- Authors: Fleischack, Anne
- Date: 2015
- Subjects: Intimate partner violence -- South Africa , Intimate partner violence -- Psychological aspects , Abused women -- Counseling of , Pregnant women -- South Africa -- Abuse of , Pregnant women -- Counseling of
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3255 , http://hdl.handle.net/10962/d1016391
- Description: South Africa is a very violent society, where violence is often used as a social resource to maintain control and establish authority. Global and local research suggests that there is a high prevalence of intimate partner violence (IPV), a facet of this violence, although little research has been conducted into the effects of IPV during pregnancy in the South African non-governmental organisation (NGO) context. NGOs globally and in South Africa have attempted to address IPV and IPV during pregnancy by providing services that aim to assist (largely female) clients emotionally and logistically. In light of this phenomenon, this qualitative study presents data generated through the use of a lightly-structured narrative interview schedule. The interviews were conducted over three sessions with eight counsellors, all based at two NGOs in South Africa and experienced in counselling women who have suffered IPV and IPV during pregnancy. This study used Taylor and Littleton’s (2006) narrative-discursive analytical lens, infused with theoretical insights from Foucault about power, discourse and narrative in order to identify the discursive resources that shape the narratives that the counsellors shared in the interviews and how these translate into subject positions and (gendered) power relations of the men and women about whom they speak. Six discursive resources emerged from the narratives, namely a discourse of ‘traditional “African” culture’, ‘patriarchal masculinity’, ‘nurturing femininity’, ‘female victimhood’, ‘female survivorhood’ and ‘human rights’. These informed the three main narratives that emerged: narratives about IPV in general, IPV during pregnancy, and the counsellors’ narratives about their intervention strategies. Within these narratives (and the micro-narratives which comprised them), men were largely positioned as subscribing to violent patriarchal behaviour whilst women were mostly positioned as nurturing and victims of this violence. The counsellors also constructed women as largely ignorant of their options about IPV and IPV during pregnancy; they constructed these phenomena as problems that require intervention and identified a number of factors that indicate what successful IPV interventions should entail. In reflecting upon this analysis, this study also aimed to address the questions of what is achieved or gained by using these narratives and discursive resources, what the significance or consequences are of constructing and using these particular narratives and discourses and whether different narratives or discourses would have been possible. Recommendations for further research includes incorporating more sites as well as interviewing perpetrators and IPV survivors themselves, perhaps in their home language where relevant rather than English, to gain a broader and more faceted understanding of the dynamics surrounding IPV during pregnancy. A recommendation for practice in intervention against IPV during pregnancy is to introduce more holistic/systemic intervention strategies and working with communities to address this issue.
- Full Text:
Counting of finite fuzzy subsets with applications to fuzzy recognition and selection strategies
- Authors: Talwanga, Matiki
- Date: 2015
- Subjects: Möbius transformations , Fuzzy sets , Functions, Zeta , Partitions (Mathematics)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5431 , http://hdl.handle.net/10962/d1018186
- Description: The counting of fuzzy subsets of a finite set is of great interest in both practical and theoretical contexts in Mathematics. We have used some counting techniques such as the principle of Inclusion-Exclusion and the Mõbius Inversion to enumerate the fuzzy subsets of a finite set satisfying different conditions. These two techniques are interdependent with the M¨obius inversion generalizing the principle of Inclusion-Exclusion. The enumeration is carried out each time we redefine new conditions on the set. In this study one of our aims is the recognition and identification of fuzzy subsets with same features, characteristics or conditions. To facilitate such a study, we use some ideas such as the Hamming distance, mid-point between two fuzzy subsets and cardinality of fuzzy subsets. Finally we introduce the fuzzy scanner of elements of a finite set. This is used to identify elements and fuzzy subsets of a set. The scanning process of identification and recognition facilitates the choice of entities with specified properties. We develop a procedure of selection under the fuzzy environment. This allows us a framework to resolve conflicting issues in the market place.
- Full Text:
- Authors: Talwanga, Matiki
- Date: 2015
- Subjects: Möbius transformations , Fuzzy sets , Functions, Zeta , Partitions (Mathematics)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5431 , http://hdl.handle.net/10962/d1018186
- Description: The counting of fuzzy subsets of a finite set is of great interest in both practical and theoretical contexts in Mathematics. We have used some counting techniques such as the principle of Inclusion-Exclusion and the Mõbius Inversion to enumerate the fuzzy subsets of a finite set satisfying different conditions. These two techniques are interdependent with the M¨obius inversion generalizing the principle of Inclusion-Exclusion. The enumeration is carried out each time we redefine new conditions on the set. In this study one of our aims is the recognition and identification of fuzzy subsets with same features, characteristics or conditions. To facilitate such a study, we use some ideas such as the Hamming distance, mid-point between two fuzzy subsets and cardinality of fuzzy subsets. Finally we introduce the fuzzy scanner of elements of a finite set. This is used to identify elements and fuzzy subsets of a set. The scanning process of identification and recognition facilitates the choice of entities with specified properties. We develop a procedure of selection under the fuzzy environment. This allows us a framework to resolve conflicting issues in the market place.
- Full Text:
Dear space dad and other stories
- Authors: Kuit, Henali
- Date: 2015
- Subjects: South African fiction (English) -- 21st century , Short stories, South African -- 21st century , Creative writing (Higher education) , South African fiction -- Study and teaching (Higher)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:5990 , http://hdl.handle.net/10962/d1017774
- Description: My stories are set around the themes of family, animals and outer space -- which leads to other themes like religion, loneliness, romance, eating animals, growing up and longing for the past. Most of the stories have non-linear structures. Some use gradual shiftings of narrator voice; in others the narrative is flat, lacking plot. I favour repetition over plot-based climaxes to create coherency and narrative flow. I also favour free indirect discourse over dialogue or description as a means to characterize.
- Full Text:
- Authors: Kuit, Henali
- Date: 2015
- Subjects: South African fiction (English) -- 21st century , Short stories, South African -- 21st century , Creative writing (Higher education) , South African fiction -- Study and teaching (Higher)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:5990 , http://hdl.handle.net/10962/d1017774
- Description: My stories are set around the themes of family, animals and outer space -- which leads to other themes like religion, loneliness, romance, eating animals, growing up and longing for the past. Most of the stories have non-linear structures. Some use gradual shiftings of narrator voice; in others the narrative is flat, lacking plot. I favour repetition over plot-based climaxes to create coherency and narrative flow. I also favour free indirect discourse over dialogue or description as a means to characterize.
- Full Text:
Design, development and evaluation of novel lead compounds as HIV-1 enzyme inhibitors
- Authors: Sekgota, Khethobole Cassius
- Date: 2015
- Subjects: Enzyme inhibitors , Viruses -- Reproduction , HIV (Viruses)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4546 , http://hdl.handle.net/10962/d1017926
- Description: This project has been concerned with the application of the Baylis-Hillman methodology to the synthesis of medicinally important diketo acid analogues (cinnamate ester-AZT conjugates and 3-hydroxy ester-AZT conjugates) as dual-action HIV-1 IN/RT inhibitors; and on exploratory studies in the preparation of 3-(amidomethyl)-(1H)-2-quinolones as PR inhibitors; and (1H)-2- quinolone-AZT conjugates as dual action IN/RT inhibitors. A series of Baylis-Hillman adducts has been prepared, typically in moderate to excellent yield, by reacting 2-nitrobenzaldehyde with methyl acrylate, ethyl acrylate and methyl vinyl ketone in the presence of 1,4- diazabicyclo[2.2.2]octane (DABCO). Subsequently, various transformations that include conjugate addition of primary and secondary amines to the α,ß-unsaturated moiety to obtain 2- (aminomethyl)-3-hydroxy-3-(2-nitrophenyl)propanoate derivatives, effective SN2´ substitution of the BH ß-hydroxy by a Vilsmeier-Haack in situ-generated chloride to afford Baylis-Hillman allyl chlorides, iron in acetic acid-catalyzed cyclisation to 3-acetoxymethyl-(1H)-2-quinolone derivatives were achieved. Thus, using the Baylis-Hillman methodology, two nuanced classes of diketo acid analogues were constructed. These involved conjugating appropriate propargylamine derivatives with AZT using the „click‟ reaction. In an exploratory study, the quinolone derivative, precisely 3-acetoxymethyl- (1H)-quinol-2-one, was transformed into 3-hydroxymethyl-(1H)-quinol-2-one using potassium carbonate in a mixture of methanol and water (1:1). Following successful hydrolysis, the resulting alcohol was transformed to the corresponding chloride, 3-chloromethyl-(1H)-quinol-2- one, using thionyl chloride. Subsequent nucleophilic substitution afforded 3-(aminomethyl)- (1H)-2-quinolone derivatives which were subsequently transformed to 3-(amidomethyl)-(1H)-2- quinolones; and 3-[(propargylamino)-methyl]-(1H)-quinol-2-one as precursors to quinolone- AZT derivatives. All compounds were characterized by NMR, IR, and where appropriate, high resolution MS
- Full Text:
- Authors: Sekgota, Khethobole Cassius
- Date: 2015
- Subjects: Enzyme inhibitors , Viruses -- Reproduction , HIV (Viruses)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4546 , http://hdl.handle.net/10962/d1017926
- Description: This project has been concerned with the application of the Baylis-Hillman methodology to the synthesis of medicinally important diketo acid analogues (cinnamate ester-AZT conjugates and 3-hydroxy ester-AZT conjugates) as dual-action HIV-1 IN/RT inhibitors; and on exploratory studies in the preparation of 3-(amidomethyl)-(1H)-2-quinolones as PR inhibitors; and (1H)-2- quinolone-AZT conjugates as dual action IN/RT inhibitors. A series of Baylis-Hillman adducts has been prepared, typically in moderate to excellent yield, by reacting 2-nitrobenzaldehyde with methyl acrylate, ethyl acrylate and methyl vinyl ketone in the presence of 1,4- diazabicyclo[2.2.2]octane (DABCO). Subsequently, various transformations that include conjugate addition of primary and secondary amines to the α,ß-unsaturated moiety to obtain 2- (aminomethyl)-3-hydroxy-3-(2-nitrophenyl)propanoate derivatives, effective SN2´ substitution of the BH ß-hydroxy by a Vilsmeier-Haack in situ-generated chloride to afford Baylis-Hillman allyl chlorides, iron in acetic acid-catalyzed cyclisation to 3-acetoxymethyl-(1H)-2-quinolone derivatives were achieved. Thus, using the Baylis-Hillman methodology, two nuanced classes of diketo acid analogues were constructed. These involved conjugating appropriate propargylamine derivatives with AZT using the „click‟ reaction. In an exploratory study, the quinolone derivative, precisely 3-acetoxymethyl- (1H)-quinol-2-one, was transformed into 3-hydroxymethyl-(1H)-quinol-2-one using potassium carbonate in a mixture of methanol and water (1:1). Following successful hydrolysis, the resulting alcohol was transformed to the corresponding chloride, 3-chloromethyl-(1H)-quinol-2- one, using thionyl chloride. Subsequent nucleophilic substitution afforded 3-(aminomethyl)- (1H)-2-quinolone derivatives which were subsequently transformed to 3-(amidomethyl)-(1H)-2- quinolones; and 3-[(propargylamino)-methyl]-(1H)-quinol-2-one as precursors to quinolone- AZT derivatives. All compounds were characterized by NMR, IR, and where appropriate, high resolution MS
- Full Text:
Determining the competency of children with developmental delays to testify in criminal trials
- Authors: Van Niekerk, Hester Aletta
- Date: 2015
- Subjects: Child witnesses -- South Africa , Developmentally disabled children -- South Africa , Children -- Legal status, laws, etc. -- South Africa , Evidence (Law) -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3722 , http://hdl.handle.net/10962/d1017878
- Description: In South Africa children are required to testify under oath or admonition. The shortcomings of the competency test are of particular relevance to children with developmental disabilities, since courts are not equipped to adequately assess the competency of these children to give evidence. One component of testimonial competency, namely the understanding of the concepts truth and lies, is overemphasised and is examined with questions that are developmentally inappropriate for child witnesses in general. For children with cognitive disabilities, such questions create barriers for participation in the truth-seeking process. Consequently, convictions have been set aside on appeal owing to procedural irregularities found in the implementation of this test. In the literature review on testimonial competency, attention was given to restrictions that specific developmental disabilities impose on the perceptual, cognitive, communication and moral development of children. Two of four components – narrative ability and moral capacity – were studied in a sample of 184 children in middle childhood. Participants’ ability to give coherent and detailed accounts of events, their understanding of the concepts truth, lies, promises and the oath, and the Lyon and Saywitz oath-taking competency test, were investigated. Quantitative and qualitative methods were used for data analysis. Three groups were identified: those children with very limited, average or full testimonial competency. Their capacities were found to be related to maturation of cognitive functions and level of intellectual functioning. Participants were better able to demonstrate their understanding of truth and falsity by responding to the oathtaking test than giving verbal descriptions of these concepts. Whereas 1 percent of participants had a conceptual understanding of an oath, 15 percent understood the concept of a promise. Syncretism and confabulation compromised the narrative accounts of a substantial number of participants. Syncretism relates to immature narrative ability: correct details are combined in an illogical fashion. Confabulation refers to filling memory gaps with fabricated information. Guidelines on the competency determination of children with developmental disabilities were compiled. It is suggested that the competency examination be replaced by a formal, pre-trial competency assessment. The court should also receive expert evidence on how to facilitate meaningful participation when a child with sufficient testimonial competence is the witness.
- Full Text:
- Authors: Van Niekerk, Hester Aletta
- Date: 2015
- Subjects: Child witnesses -- South Africa , Developmentally disabled children -- South Africa , Children -- Legal status, laws, etc. -- South Africa , Evidence (Law) -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3722 , http://hdl.handle.net/10962/d1017878
- Description: In South Africa children are required to testify under oath or admonition. The shortcomings of the competency test are of particular relevance to children with developmental disabilities, since courts are not equipped to adequately assess the competency of these children to give evidence. One component of testimonial competency, namely the understanding of the concepts truth and lies, is overemphasised and is examined with questions that are developmentally inappropriate for child witnesses in general. For children with cognitive disabilities, such questions create barriers for participation in the truth-seeking process. Consequently, convictions have been set aside on appeal owing to procedural irregularities found in the implementation of this test. In the literature review on testimonial competency, attention was given to restrictions that specific developmental disabilities impose on the perceptual, cognitive, communication and moral development of children. Two of four components – narrative ability and moral capacity – were studied in a sample of 184 children in middle childhood. Participants’ ability to give coherent and detailed accounts of events, their understanding of the concepts truth, lies, promises and the oath, and the Lyon and Saywitz oath-taking competency test, were investigated. Quantitative and qualitative methods were used for data analysis. Three groups were identified: those children with very limited, average or full testimonial competency. Their capacities were found to be related to maturation of cognitive functions and level of intellectual functioning. Participants were better able to demonstrate their understanding of truth and falsity by responding to the oathtaking test than giving verbal descriptions of these concepts. Whereas 1 percent of participants had a conceptual understanding of an oath, 15 percent understood the concept of a promise. Syncretism and confabulation compromised the narrative accounts of a substantial number of participants. Syncretism relates to immature narrative ability: correct details are combined in an illogical fashion. Confabulation refers to filling memory gaps with fabricated information. Guidelines on the competency determination of children with developmental disabilities were compiled. It is suggested that the competency examination be replaced by a formal, pre-trial competency assessment. The court should also receive expert evidence on how to facilitate meaningful participation when a child with sufficient testimonial competence is the witness.
- Full Text:
Developed teacher leadership in a township high school : an interpretive case study
- Authors: John, Daisy Mary
- Date: 2015
- Subjects: Educational leadership -- South Africa -- Eastern Cape , School management and organization -- South Africa -- Eastern Cape , Teacher participation in administration -- South Africa -- Eastern Cape , Teacher effectiveness -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:2052 , http://hdl.handle.net/10962/d1018548
- Description: South Africa’s future success depends on a number of national priorities, amongst them the transformation of its education system. Education is the best route to follow to alleviate poverty and many other social ills. One way to overcome some of the complex challenges and crises that we face in South African schools is to pay attention to issues of leading and leadership, including the leadership of teachers. This study is done with the hope that research into teacher leadership will be one of the answers to the crisis in education. It should become a beacon of hope for all educationists who passionately want progress in the youth of South Africa. What better way than to ‘Awaken the Sleeping Giant’ of teacher leadership, borrowing the term from Katzenmeyer and Moller (2009). This study was designed as a case study, the purpose of which was to find out about the enactment of teacher leadership in an Eastern Cape township high school as well as the enhancing and hindering factors to this enactment. This study was done as a replication study of a similar study done by a group of 11Master’s students at the University of KwaZulu-Natal in 2010. Similar to the original study, this case study was located within the interpretive paradigm and drew on school profiling, survey questionnaires, a focus group interview, selfreflective journals and individual interviews for its methods of data collection. The study was framed by distributed leadership while Grant’s (2008; 2012) Model of teacher leadership was adopted as the analytical tool. It emerged from the data that the three teacher leaders, my primary participants, exhibited teacher leadership across all four zones of Grant’s (2008) Model. The first zone was leadership in the classroom where all three teacher leaders showed leadership to varying degrees. Zones Two to Four are about leadership beyond the classroom into the school and beyond. In Zone Two, the zone where teachers work with each other and the learners outside the classroom, substantial levels of leadership were enacted by the three teacher leaders. Zone Three, where leadership is exhibited in whole-school development, the three primary participants showed distinct leadership qualities as well. The fourth zone, which is about interaction with neighbouring schools, also revealed that all three teacher leaders demonstrated active leadership on a regular basis. Findings further revealed that there were only a few inhibiting factors to the leadership of teachers at the case study school, including limited resources and infrastructure as well as insufficient support and acknowledgement from the relevant stakeholders when leadership initiatives were made, either successfully or otherwise. However, the enhancing factors superseded the inhibiting factors. A functional committee culture guided by a shared vision existed in the case study school together with an ethos of trust which enabled the staff to work collaboratively. Though there was certainly room for improvement in leadership practices at this case study school, the enactment of teacher leadership in this school illustrated a strong case of ‘developed’ teacher leadership (Muijs& Harris, 2007) within a dispersed leadership framing (Gunter, 2005)
- Full Text:
- Authors: John, Daisy Mary
- Date: 2015
- Subjects: Educational leadership -- South Africa -- Eastern Cape , School management and organization -- South Africa -- Eastern Cape , Teacher participation in administration -- South Africa -- Eastern Cape , Teacher effectiveness -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:2052 , http://hdl.handle.net/10962/d1018548
- Description: South Africa’s future success depends on a number of national priorities, amongst them the transformation of its education system. Education is the best route to follow to alleviate poverty and many other social ills. One way to overcome some of the complex challenges and crises that we face in South African schools is to pay attention to issues of leading and leadership, including the leadership of teachers. This study is done with the hope that research into teacher leadership will be one of the answers to the crisis in education. It should become a beacon of hope for all educationists who passionately want progress in the youth of South Africa. What better way than to ‘Awaken the Sleeping Giant’ of teacher leadership, borrowing the term from Katzenmeyer and Moller (2009). This study was designed as a case study, the purpose of which was to find out about the enactment of teacher leadership in an Eastern Cape township high school as well as the enhancing and hindering factors to this enactment. This study was done as a replication study of a similar study done by a group of 11Master’s students at the University of KwaZulu-Natal in 2010. Similar to the original study, this case study was located within the interpretive paradigm and drew on school profiling, survey questionnaires, a focus group interview, selfreflective journals and individual interviews for its methods of data collection. The study was framed by distributed leadership while Grant’s (2008; 2012) Model of teacher leadership was adopted as the analytical tool. It emerged from the data that the three teacher leaders, my primary participants, exhibited teacher leadership across all four zones of Grant’s (2008) Model. The first zone was leadership in the classroom where all three teacher leaders showed leadership to varying degrees. Zones Two to Four are about leadership beyond the classroom into the school and beyond. In Zone Two, the zone where teachers work with each other and the learners outside the classroom, substantial levels of leadership were enacted by the three teacher leaders. Zone Three, where leadership is exhibited in whole-school development, the three primary participants showed distinct leadership qualities as well. The fourth zone, which is about interaction with neighbouring schools, also revealed that all three teacher leaders demonstrated active leadership on a regular basis. Findings further revealed that there were only a few inhibiting factors to the leadership of teachers at the case study school, including limited resources and infrastructure as well as insufficient support and acknowledgement from the relevant stakeholders when leadership initiatives were made, either successfully or otherwise. However, the enhancing factors superseded the inhibiting factors. A functional committee culture guided by a shared vision existed in the case study school together with an ethos of trust which enabled the staff to work collaboratively. Though there was certainly room for improvement in leadership practices at this case study school, the enactment of teacher leadership in this school illustrated a strong case of ‘developed’ teacher leadership (Muijs& Harris, 2007) within a dispersed leadership framing (Gunter, 2005)
- Full Text:
Developing a cross platform IMS client using the JAIN SIP applet phone
- Authors: Muswera, Walter Tawanda
- Date: 2015
- Subjects: Internet Protocol multimedia subsystem , Java (Computer program language)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4712 , http://hdl.handle.net/10962/d1017934
- Description: Since the introduction of the IP Multimedia Subsystem (IMS) by the Third Generation Partnership Project (3GPP) in 2002, a lot of research has been conducted aimed at designing and implementing IMS capable clients and network elements. Though considerable work has been done in the development of IMS clients, there is no single, free and open source IMS client that provides researchers with all the required functionality needed to test the applications they are developing. For example, several open and closed source SIP/IMS clients are used within the Rhodes University Conver- gence Research Group (RUCRG) to test applications under development, as a result of the fact that the various SIP/IMS clients support different subsets of SIP/IMS features. The lack of a single client and the subsequent use of various clients comes with several problems. Researchers have to know how to deploy, configure, use and at times adapt the various clients to suit their needs. This can be very time consuming and, in fact, contradicts the IMS philosophy (the IMS was proposed to support rapid service creation). This thesis outlines the development of a Java-based, IMS compliant client called RUCRG IMS client, that uses the JAIN SIP Applet Phone (JSAP) as its foundation. JSAP, which originally offered only basic voice calling and instant messaging (IM) capabilities, was modified to be IMS compliant and support video calls, IM and presence using XML Configuration Access Protocol (XCAP).
- Full Text:
- Authors: Muswera, Walter Tawanda
- Date: 2015
- Subjects: Internet Protocol multimedia subsystem , Java (Computer program language)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4712 , http://hdl.handle.net/10962/d1017934
- Description: Since the introduction of the IP Multimedia Subsystem (IMS) by the Third Generation Partnership Project (3GPP) in 2002, a lot of research has been conducted aimed at designing and implementing IMS capable clients and network elements. Though considerable work has been done in the development of IMS clients, there is no single, free and open source IMS client that provides researchers with all the required functionality needed to test the applications they are developing. For example, several open and closed source SIP/IMS clients are used within the Rhodes University Conver- gence Research Group (RUCRG) to test applications under development, as a result of the fact that the various SIP/IMS clients support different subsets of SIP/IMS features. The lack of a single client and the subsequent use of various clients comes with several problems. Researchers have to know how to deploy, configure, use and at times adapt the various clients to suit their needs. This can be very time consuming and, in fact, contradicts the IMS philosophy (the IMS was proposed to support rapid service creation). This thesis outlines the development of a Java-based, IMS compliant client called RUCRG IMS client, that uses the JAIN SIP Applet Phone (JSAP) as its foundation. JSAP, which originally offered only basic voice calling and instant messaging (IM) capabilities, was modified to be IMS compliant and support video calls, IM and presence using XML Configuration Access Protocol (XCAP).
- Full Text:
Developing a GIS based method for school site identification in the rural Eastern Cape
- Authors: Swart, Conrad Dirk
- Date: 2015
- Subjects: Geographic information systems -- South Africa -- Eastern Cape , School sites -- South Africa -- Eastern Cape , School sites -- South Africa -- Eastern Cape -- Planning , Rural schools -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4891 , http://hdl.handle.net/10962/d1018939
- Description: Historically, South Africa has not had equal education in terms of funding, curriculum or physical resources and structures. These issues are still present in contemporary South Africa and none more so than the issues surrounding “mud schools”. Recently the Department of Basic Education (DBE) implemented a plan to eradicate inappropriate school structures using the Accelerated Schools Infrastructure Delivery Initiative program (ASIDI). Questions around effective placement of schools are now being asked. Using interviews and analysis of literature, this research developed criteria needed to determine how rural school sites are selected. Geographical Information Systems (GIS) was used to determine if current sites are in the most appropriate areas. The results of the research included a unique set of Eastern Cape criteria as well as an analysis of the current site selection methods used by the DBE. It also revealed that most of the schools are being constructed in acceptable areas. The main result that emerged from the research was that schools will be placed in areas where they are needed. Developing site selection criteria is still needed as South Africa seeks to reduce the education gap between rich and poor schools.
- Full Text:
- Authors: Swart, Conrad Dirk
- Date: 2015
- Subjects: Geographic information systems -- South Africa -- Eastern Cape , School sites -- South Africa -- Eastern Cape , School sites -- South Africa -- Eastern Cape -- Planning , Rural schools -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4891 , http://hdl.handle.net/10962/d1018939
- Description: Historically, South Africa has not had equal education in terms of funding, curriculum or physical resources and structures. These issues are still present in contemporary South Africa and none more so than the issues surrounding “mud schools”. Recently the Department of Basic Education (DBE) implemented a plan to eradicate inappropriate school structures using the Accelerated Schools Infrastructure Delivery Initiative program (ASIDI). Questions around effective placement of schools are now being asked. Using interviews and analysis of literature, this research developed criteria needed to determine how rural school sites are selected. Geographical Information Systems (GIS) was used to determine if current sites are in the most appropriate areas. The results of the research included a unique set of Eastern Cape criteria as well as an analysis of the current site selection methods used by the DBE. It also revealed that most of the schools are being constructed in acceptable areas. The main result that emerged from the research was that schools will be placed in areas where they are needed. Developing site selection criteria is still needed as South Africa seeks to reduce the education gap between rich and poor schools.
- Full Text:
Developing a performance measurement tool to monitor the performance of a public sector agency : a balanced scorecard approach
- Authors: Lisani, Ncedo
- Date: 2015
- Subjects: South Africa. Economic Development Department , South Africa. Department of Environmental Affairs and Tourism , Performance -- Measurement , Performance -- Management , Public administration -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:848 , http://hdl.handle.net/10962/d1017515
- Description: The world has seen unparalleled pressure put on the public sector to improve the speed and quality of service delivery, whilst simultaneously employing measures to cut the costs. South Africa and the Eastern Cape have not been immune to this as there have been complaints and demonstrations from various national and provincial stakeholders demanding more and improved services. The Department of Economic Development, Environmental Affairs and Tourism (DEDEAT) in particular has employed the services of public entities in its quest to realise government’s socio-economic developmental objectives and ease some of the service delivery pressures. These agencies are unfortunately struggling to deliver and the Department is unable to play the oversight role it is legislatively mandated to carry out. The main reason for this seem to be the lack of the capacity to objectively track and measure the performance of these agencies. As they say “you cannot manage what you cannot measure”. This is despite the fact that there is a shareholders’ compact and many other measures in place to enable performance monitoring. Also, the public sector is known to have inherent and unique performance management challenges like broad and vague objectives which lead to too many measurements, a propensity to focus on the “easy to measure” but often irrelevant indicators at the expense of critical outcomes and a short-term orientation that is usually fuelled by political expediency. Against this background, this study sought to make use of a comprehensive and dynamic performance monitoring framework, namely the Balanced Scorecard (BSC), to explore its potential use in assisting government to monitor the performance of public agencies, in particular the Development Finance Institutions (DFI) in South Africa. The proposed framework helps government to focus on the performance drivers of future value, and what decisions and actions are necessary to achieve critical outcomes. The aim of the study therefore is to develop an adjusted BSC framework to monitor the activities of a public sector agency and thus demonstrate how a BSC framework could be used to monitor a public agency by the government department. The study is evaluative in nature and is divided into three sections. Section one is presented as an Evaluation Report. It sets the scene, discusses briefly the key theoretical concepts, outlines the research methods used and presents the findings followed by a discussion and recommendations. Section two delves into the literature in more detail, providing a more extensive review of the literature that informed the investigation, whilst section three provides a more extensive description of the research methodology employed in the study. To achieve the aims of the study, the research drew from the work of various authors in the field including that of Bigliardi, Dormio and Galati, 2011; Bititci, Garengo, Dörfler, and Nudurupati, 2012; Julyan, 2011; Kaplan and Norton, 1992, 1993, 1996, 2001, 2004 and 2006; Niven, 2003 and 2008 and Northcott and Taulapapa, 2012. Also, five BSC perspectives - including the programme specific “equity” perspective - were used to develop an interview schedule. These were used to formulate the key performance objectives and indicators, based on the stakeholder’s responses. These respondents have experience within the programme as administrators, beneficiaries and funders. The research employed purposive sampling with semi-structured in-depth interviews and document analysis as primary and secondary instruments for data collection. In essence, five officials from the agency, one from DEDEAT and two co-operatives participated in the research. The results indicate a general appreciation of and gravitation towards outcome based measures, even though the government culture of focusing on outputs is still prevalent. The results of the study indicated that, generally, a government - public agency BSC based performance monitoring framework would have the following features: Customer objectives and programme mission as the main goal and this will provides clarity at all levels on who the customers are and what are their primary requirements. Clear, visible and stringent financial controls as the agency is administering public resources. Few carefully selected processes and systems that have a direct and positive impact on the customer objectives. Deliberate and consistent efforts to promote the participation of designated groups in the economy of the country. Comprehensive indicators on capacity building as “mission based-organisations rely heavily on skills, dedication and alignment of staff”. Overall, the study concludes that the make-up of the BSC is beneficial to the public sector and in monitoring the public sector agencies for the following reasons: It helps the agency to focus on customers and their needs. It forces the agency to engage and communicate strategic intention with both internal and external stakeholders and thus synchronize competing stakeholder needs. It forces the agency to limit the number of indicators and therefore select the few value adding measures that are aligned to customer outcomes. Through its cause and effect relationship, the agency is compelled to align all the resources, activities and processes to the main goal of the entity. All these help to minimize the principal agent problem, as the use of the BSC can bring clarity on strategy and expectations, provided it is supported with regular communication.
- Full Text:
- Authors: Lisani, Ncedo
- Date: 2015
- Subjects: South Africa. Economic Development Department , South Africa. Department of Environmental Affairs and Tourism , Performance -- Measurement , Performance -- Management , Public administration -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:848 , http://hdl.handle.net/10962/d1017515
- Description: The world has seen unparalleled pressure put on the public sector to improve the speed and quality of service delivery, whilst simultaneously employing measures to cut the costs. South Africa and the Eastern Cape have not been immune to this as there have been complaints and demonstrations from various national and provincial stakeholders demanding more and improved services. The Department of Economic Development, Environmental Affairs and Tourism (DEDEAT) in particular has employed the services of public entities in its quest to realise government’s socio-economic developmental objectives and ease some of the service delivery pressures. These agencies are unfortunately struggling to deliver and the Department is unable to play the oversight role it is legislatively mandated to carry out. The main reason for this seem to be the lack of the capacity to objectively track and measure the performance of these agencies. As they say “you cannot manage what you cannot measure”. This is despite the fact that there is a shareholders’ compact and many other measures in place to enable performance monitoring. Also, the public sector is known to have inherent and unique performance management challenges like broad and vague objectives which lead to too many measurements, a propensity to focus on the “easy to measure” but often irrelevant indicators at the expense of critical outcomes and a short-term orientation that is usually fuelled by political expediency. Against this background, this study sought to make use of a comprehensive and dynamic performance monitoring framework, namely the Balanced Scorecard (BSC), to explore its potential use in assisting government to monitor the performance of public agencies, in particular the Development Finance Institutions (DFI) in South Africa. The proposed framework helps government to focus on the performance drivers of future value, and what decisions and actions are necessary to achieve critical outcomes. The aim of the study therefore is to develop an adjusted BSC framework to monitor the activities of a public sector agency and thus demonstrate how a BSC framework could be used to monitor a public agency by the government department. The study is evaluative in nature and is divided into three sections. Section one is presented as an Evaluation Report. It sets the scene, discusses briefly the key theoretical concepts, outlines the research methods used and presents the findings followed by a discussion and recommendations. Section two delves into the literature in more detail, providing a more extensive review of the literature that informed the investigation, whilst section three provides a more extensive description of the research methodology employed in the study. To achieve the aims of the study, the research drew from the work of various authors in the field including that of Bigliardi, Dormio and Galati, 2011; Bititci, Garengo, Dörfler, and Nudurupati, 2012; Julyan, 2011; Kaplan and Norton, 1992, 1993, 1996, 2001, 2004 and 2006; Niven, 2003 and 2008 and Northcott and Taulapapa, 2012. Also, five BSC perspectives - including the programme specific “equity” perspective - were used to develop an interview schedule. These were used to formulate the key performance objectives and indicators, based on the stakeholder’s responses. These respondents have experience within the programme as administrators, beneficiaries and funders. The research employed purposive sampling with semi-structured in-depth interviews and document analysis as primary and secondary instruments for data collection. In essence, five officials from the agency, one from DEDEAT and two co-operatives participated in the research. The results indicate a general appreciation of and gravitation towards outcome based measures, even though the government culture of focusing on outputs is still prevalent. The results of the study indicated that, generally, a government - public agency BSC based performance monitoring framework would have the following features: Customer objectives and programme mission as the main goal and this will provides clarity at all levels on who the customers are and what are their primary requirements. Clear, visible and stringent financial controls as the agency is administering public resources. Few carefully selected processes and systems that have a direct and positive impact on the customer objectives. Deliberate and consistent efforts to promote the participation of designated groups in the economy of the country. Comprehensive indicators on capacity building as “mission based-organisations rely heavily on skills, dedication and alignment of staff”. Overall, the study concludes that the make-up of the BSC is beneficial to the public sector and in monitoring the public sector agencies for the following reasons: It helps the agency to focus on customers and their needs. It forces the agency to engage and communicate strategic intention with both internal and external stakeholders and thus synchronize competing stakeholder needs. It forces the agency to limit the number of indicators and therefore select the few value adding measures that are aligned to customer outcomes. Through its cause and effect relationship, the agency is compelled to align all the resources, activities and processes to the main goal of the entity. All these help to minimize the principal agent problem, as the use of the BSC can bring clarity on strategy and expectations, provided it is supported with regular communication.
- Full Text:
Developing and using an assessment instrument for spatial skills in Grade 10 geometry learners
- Authors: Cowley, Jane
- Date: 2015
- Subjects: Geometry -- Study and teaching (Secondary) -- South Africa -- Eastern Cape , Geometry -- Evaluation. , Mathematics -- Study and teaching (Secondary)
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:2025 , http://hdl.handle.net/10962/d1017336
- Description: This qualitative investigation took the form of a case study and fell within the interpretive research paradigm. The Mathematics Chair at the Education Department of Rhodes University launched the Mathematics Teacher Enrichment Programme (MTEP) in 2010 in order to combat poor Mathematics performance of learners in the lower Albany district of the Eastern Cape. The challenge that the participating MTEP teachers faced was a lack of time available to implement new teaching ideas. This was because most of their time was spent catching up “lost” or untaught concepts in the classroom. To address this problem, the Catch-Up Project was launched, whereby selected Mathematics teachers in the area taught lost concepts to Grade Ten learners during afternoon classes in an attempt to improve their fundamental Mathematics knowledge. In order to establish which sections of Mathematics were more difficult for the learners in this programme, bench mark tests were administered biannually. Whilst these tests certainly identified deficient areas within their Mathematics knowledge, the poorest performance areas were the sections of the syllabus which were spatial in nature, such as Space and Shape and Geometry. However, a more in depth assessment tool was required to establish which specific spatial skills the learners were not able to employ when doing these Geometry tasks. To this end, the Spatial Skills Assessment Tasks (SSAT) was developed. It consisted of traditional text book type Geometry tasks and real-world context tasks, both of which were used to assess six spatial skills deemed crucial to successfully facilitate learning Geometry. The case study took place in two of the schools which participated in the Grade Ten Catch-Up project. The case was focused on Grade Ten learners and the unit of analysis was their responses to the SSAT instrument. The learners that participated all did so on a strictly voluntary basis and great care was taken to protect their wellbeing and anonymity at all times. The results of the SSAT instrument revealed that the real world context tasks were in general far more successfully answered than the traditional text book type questions. Important trends in learner responses were noted and highlighted. For example, geometric terminology remains a huge challenge for learners, especially as they study Mathematics in their second language. The ability of the learners to differentiate between such concepts as congruency and similarity is severely compromised, partly due to a lack of terminological understanding but also due to a perceived lack of exposure to the material. Concepts such as verticality and horizontality also remain a huge challenge, possibly for the same reasons. They are poorly understood and yet vital to achievement in Geometry. Recommendations for the development and strengthening of spatial skills support the constructivist approach to learning. Hands on activities and intensive sustained practice over a period of a few months, in which both teachers and learners are actively involved in the learning process, would be considered most beneficial to the long term enhancement of these vital spatial skills and to the learning of Geometry in general.
- Full Text:
- Authors: Cowley, Jane
- Date: 2015
- Subjects: Geometry -- Study and teaching (Secondary) -- South Africa -- Eastern Cape , Geometry -- Evaluation. , Mathematics -- Study and teaching (Secondary)
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:2025 , http://hdl.handle.net/10962/d1017336
- Description: This qualitative investigation took the form of a case study and fell within the interpretive research paradigm. The Mathematics Chair at the Education Department of Rhodes University launched the Mathematics Teacher Enrichment Programme (MTEP) in 2010 in order to combat poor Mathematics performance of learners in the lower Albany district of the Eastern Cape. The challenge that the participating MTEP teachers faced was a lack of time available to implement new teaching ideas. This was because most of their time was spent catching up “lost” or untaught concepts in the classroom. To address this problem, the Catch-Up Project was launched, whereby selected Mathematics teachers in the area taught lost concepts to Grade Ten learners during afternoon classes in an attempt to improve their fundamental Mathematics knowledge. In order to establish which sections of Mathematics were more difficult for the learners in this programme, bench mark tests were administered biannually. Whilst these tests certainly identified deficient areas within their Mathematics knowledge, the poorest performance areas were the sections of the syllabus which were spatial in nature, such as Space and Shape and Geometry. However, a more in depth assessment tool was required to establish which specific spatial skills the learners were not able to employ when doing these Geometry tasks. To this end, the Spatial Skills Assessment Tasks (SSAT) was developed. It consisted of traditional text book type Geometry tasks and real-world context tasks, both of which were used to assess six spatial skills deemed crucial to successfully facilitate learning Geometry. The case study took place in two of the schools which participated in the Grade Ten Catch-Up project. The case was focused on Grade Ten learners and the unit of analysis was their responses to the SSAT instrument. The learners that participated all did so on a strictly voluntary basis and great care was taken to protect their wellbeing and anonymity at all times. The results of the SSAT instrument revealed that the real world context tasks were in general far more successfully answered than the traditional text book type questions. Important trends in learner responses were noted and highlighted. For example, geometric terminology remains a huge challenge for learners, especially as they study Mathematics in their second language. The ability of the learners to differentiate between such concepts as congruency and similarity is severely compromised, partly due to a lack of terminological understanding but also due to a perceived lack of exposure to the material. Concepts such as verticality and horizontality also remain a huge challenge, possibly for the same reasons. They are poorly understood and yet vital to achievement in Geometry. Recommendations for the development and strengthening of spatial skills support the constructivist approach to learning. Hands on activities and intensive sustained practice over a period of a few months, in which both teachers and learners are actively involved in the learning process, would be considered most beneficial to the long term enhancement of these vital spatial skills and to the learning of Geometry in general.
- Full Text:
Developing high-fidelity mental models of programming concepts using manipulatives and interactive metaphors
- Authors: Funcke, Matthew
- Date: 2015
- Subjects: Computer programming -- Study and teaching (Higher) , Computer programmers
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4707 , http://hdl.handle.net/10962/d1017929
- Description: It is well established that both learning and teaching programming are difficult tasks. Difficulties often occur due to weak mental models and common misconceptions. This study proposes a method of teaching programming that both encourages high-fidelity mental models and attempts to minimise misconceptions in novice programmers, through the use of metaphors and manipulatives. The elements in ActionWorld with which the students interact are realizations of metaphors. By simple example, a variable has a metaphorical representation as a labelled box that can hold a value. The dissertation develops a set of metaphors which have several core requirements: metaphors should avoid causing misconceptions, they need to be high-fidelity so as to avoid failing when used with a new concept, students must be able to relate to them, and finally, they should be usable across multiple educational media. The learning style that ActionWorld supports is one which requires active participation from the student - the system acts as a foundation upon which students are encouraged to build their mental models. This teaching style is achieved by placing the student in the role of code interpreter, the code they need to interpret will not advance until they have demonstrated its meaning via use of the aforementioned metaphors. ActionWorld was developed using an iterative developmental process that consistently improved upon various aspects of the project through a continual evaluation-enhancement cycle. The primary outputs of this project include a unified set of high-fidelity metaphors, a virtual-machine API for use in similar future projects, and two metaphor-testing games. All of the aforementioned deliverables were tested using multiple quality-evaluation criteria, the results of which were consistently positive. ActionWorld and its constituent components contribute to the wide assortment of methods one might use to teach novice programmers.
- Full Text:
- Authors: Funcke, Matthew
- Date: 2015
- Subjects: Computer programming -- Study and teaching (Higher) , Computer programmers
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4707 , http://hdl.handle.net/10962/d1017929
- Description: It is well established that both learning and teaching programming are difficult tasks. Difficulties often occur due to weak mental models and common misconceptions. This study proposes a method of teaching programming that both encourages high-fidelity mental models and attempts to minimise misconceptions in novice programmers, through the use of metaphors and manipulatives. The elements in ActionWorld with which the students interact are realizations of metaphors. By simple example, a variable has a metaphorical representation as a labelled box that can hold a value. The dissertation develops a set of metaphors which have several core requirements: metaphors should avoid causing misconceptions, they need to be high-fidelity so as to avoid failing when used with a new concept, students must be able to relate to them, and finally, they should be usable across multiple educational media. The learning style that ActionWorld supports is one which requires active participation from the student - the system acts as a foundation upon which students are encouraged to build their mental models. This teaching style is achieved by placing the student in the role of code interpreter, the code they need to interpret will not advance until they have demonstrated its meaning via use of the aforementioned metaphors. ActionWorld was developed using an iterative developmental process that consistently improved upon various aspects of the project through a continual evaluation-enhancement cycle. The primary outputs of this project include a unified set of high-fidelity metaphors, a virtual-machine API for use in similar future projects, and two metaphor-testing games. All of the aforementioned deliverables were tested using multiple quality-evaluation criteria, the results of which were consistently positive. ActionWorld and its constituent components contribute to the wide assortment of methods one might use to teach novice programmers.
- Full Text:
Development and manufacture of sustained release captopril beads
- Authors: Mhaka, Farai Arthur
- Date: 2015
- Language: English
- Type: text , Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/54712 , vital:26602
- Description: Hypertension has a high mortality rate in developing countries such as South Africa. Although the prevention and control of hypertension is a health priority, efforts to decrease the global burden of hypertension and improve control over the condition are inadequate. The use of angiotensin converting enzyme (ACE) inhibitors such as captopril (CPT) have been effective for the management of hypertension when used as first line therapy alone or in combination. Commercially available immediate release dosage forms containing 12.5, 25 and 50 mg of CPT are administered two or three times a day to treat hypertension. CPT degrades in aqueous media with the sulfhydryl functional moiety responsible for adverse effects such as hypersensitivity, taste disturbances and/or presenting with a dry hacking cough. CPT has a short elimination half-life of between 1.6 and 1.9 hours, which means that the compound is a suitable candidate for inclusion in sustained release (SR) dosage forms. Manufacturing a SR dosage form of coated beads for twice daily dosing may reduce the incidence and intensity of undesirable adverse effects, improve the stability of CPT and improve patient adherence. A stability indicating reversed-phase high performance liquid chromatographic (RP-HPLC) method was developed and optimised using a central composite design approach. As part of this approach the interactive effects of input factors, viz. pH, methanol (MeOH) content and column temperature on retention time, were investigated to achieve a separation with well-resolved and symmetrical peaks for CPT and salicylic acid. The method was validated using ICH guidelines and was found to be simple, linear, precise, accurate, selective and rapid for the in vitro quantitation of CPT. The method was successfully applied for the analysis of both commercially available and test formulations. Preformulation studies were undertaken to establish the physical and chemical properties of CPT, excipients and dosage forms to ensure the production of stabile and bioavailable products. Powder blends were assessed for flow properties using angle of repose (AOR), and bulk and tapped density, which were subsequently used to calculate Carr’s Index (CI) and the Hausner ratio (HR). The addition of talc resulted in the most powder blends with AOR, CI and HR that were within a range indicative of satisfactory to good flow properties. The use of talc was necessary to ensure that blending prior to wet granulation and extrusion-spheronisation would produce homogenous powders. Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and Fourier Transform Infrared Spectroscopy (FT-IR) were used for the identification and purity of CPT alone and 1:1 binary mixtures with excipients in an effort to establish if CPT was likely to undergo physical and/or chemical modification during production. The DSC thermograms for all CPT-excipient mixtures revealed the presence of a melting endotherm that was wider, occurring at 110.93 °C (Tpeak for pure CPT). The characteristic peaks for specific functional groups were present in the FT-IR spectra for powder mixtures, indicating the absence of incompatibilities. Dialysis studies were used to investigate if the ammonium oleate present in Surelease® E-7-19010 interacted with CPT. The results suggests that an interaction between CPT and Surelease® E-7-19010 during processing of CPT beads was unlikely to occur. Preliminary investigations reveal that Methocel® K100M, Methocel® E4M, Avicel® PH102, Eudragit® RS PO, Surelease® E-7-19010 and talc are compatible with CPT and could be used for the manufacture of SR CPT beads. CPT beads were manufactured using extrusion-spheronisation and coated using a fluidised bed drier fitted with a Wurster insert. The amount of granulating fluid, coating levels, curing time and formulation composition were varied to achieve CPT release with specific criteria to develop a preliminary formulation. The coated beads met all desired quality attributes in respect of micromeritic and flow properties, content uniformity and friability. Response Surface Methodology was used to further optimise the SR CPT formulation. The Plackett-Burman design was used for this process to produce an SR dosage form with desirable quality attributes achieved by altering formulation composition, extrusion-spheronisation variables and coating parameters. ANOVA data revealed significant responses for yield, aspect ratio, sphericity, coating efficiency and cumulative percent CPT released at 2 and 12 hours. Formulations in which the high molecular weight HPMC were used in increased concentrations resulted in the formation of a sticky wet mass and extrudate, resulting in a decrease in yield. The application of a permeable, but insoluble Surelease® coat onto the surface of the beads formed a barrier that complements the activity of the hydrophilic matrix in preventing rapid dissolution and retarding the release of CPT from the beads. The amount of CPT released over 12 hours revealed that increasing the Methocel® K100M content entrapped CPT and retained it more efficiently in the hydrated matrix, resulting in a slow rate of CPT release. In vitro release data were fitted to a number of models in an attempt to elucidate mechanistic aspects of transport processes specific to CPT from the coated bead formulations. The results of fitting data from optimised batches revealed that the goodness of fit based on the adjusted correlation coefficient ranged between 0.953 and 0.976 for the Higuchi model, indicating that diffusion is a predominant factor that controls CPT release from the coated beads. The results of fitting data to the Korsmeyer-Peppas model suggest that the mechanism of CPT release includes transport of the dissolution medium from the vessel reservoir into the core of the bead due to osmotic potential, dissolution of CPT, mass transfer of the dissolved CPT within the core, partitioning between the solution and polymeric film, mass transfer of dissolved CPT through the film to ultimately reach the bulk dissolution fluid. A SR CPT bead formulation that has potential for further development and optimisation for scaled-up production using RSM approaches and Design of Experiments such as CCD or Box-Behnken has been successfully developed and manufactured using extrusion, spheronisation and coating processes. Assessment of all batches of beads manufactured exhibited satisfactory to good flow properties and demonstrated SR profiles over 12 hours that met USP criteria for SR dosage forms.
- Full Text:
- Authors: Mhaka, Farai Arthur
- Date: 2015
- Language: English
- Type: text , Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/54712 , vital:26602
- Description: Hypertension has a high mortality rate in developing countries such as South Africa. Although the prevention and control of hypertension is a health priority, efforts to decrease the global burden of hypertension and improve control over the condition are inadequate. The use of angiotensin converting enzyme (ACE) inhibitors such as captopril (CPT) have been effective for the management of hypertension when used as first line therapy alone or in combination. Commercially available immediate release dosage forms containing 12.5, 25 and 50 mg of CPT are administered two or three times a day to treat hypertension. CPT degrades in aqueous media with the sulfhydryl functional moiety responsible for adverse effects such as hypersensitivity, taste disturbances and/or presenting with a dry hacking cough. CPT has a short elimination half-life of between 1.6 and 1.9 hours, which means that the compound is a suitable candidate for inclusion in sustained release (SR) dosage forms. Manufacturing a SR dosage form of coated beads for twice daily dosing may reduce the incidence and intensity of undesirable adverse effects, improve the stability of CPT and improve patient adherence. A stability indicating reversed-phase high performance liquid chromatographic (RP-HPLC) method was developed and optimised using a central composite design approach. As part of this approach the interactive effects of input factors, viz. pH, methanol (MeOH) content and column temperature on retention time, were investigated to achieve a separation with well-resolved and symmetrical peaks for CPT and salicylic acid. The method was validated using ICH guidelines and was found to be simple, linear, precise, accurate, selective and rapid for the in vitro quantitation of CPT. The method was successfully applied for the analysis of both commercially available and test formulations. Preformulation studies were undertaken to establish the physical and chemical properties of CPT, excipients and dosage forms to ensure the production of stabile and bioavailable products. Powder blends were assessed for flow properties using angle of repose (AOR), and bulk and tapped density, which were subsequently used to calculate Carr’s Index (CI) and the Hausner ratio (HR). The addition of talc resulted in the most powder blends with AOR, CI and HR that were within a range indicative of satisfactory to good flow properties. The use of talc was necessary to ensure that blending prior to wet granulation and extrusion-spheronisation would produce homogenous powders. Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and Fourier Transform Infrared Spectroscopy (FT-IR) were used for the identification and purity of CPT alone and 1:1 binary mixtures with excipients in an effort to establish if CPT was likely to undergo physical and/or chemical modification during production. The DSC thermograms for all CPT-excipient mixtures revealed the presence of a melting endotherm that was wider, occurring at 110.93 °C (Tpeak for pure CPT). The characteristic peaks for specific functional groups were present in the FT-IR spectra for powder mixtures, indicating the absence of incompatibilities. Dialysis studies were used to investigate if the ammonium oleate present in Surelease® E-7-19010 interacted with CPT. The results suggests that an interaction between CPT and Surelease® E-7-19010 during processing of CPT beads was unlikely to occur. Preliminary investigations reveal that Methocel® K100M, Methocel® E4M, Avicel® PH102, Eudragit® RS PO, Surelease® E-7-19010 and talc are compatible with CPT and could be used for the manufacture of SR CPT beads. CPT beads were manufactured using extrusion-spheronisation and coated using a fluidised bed drier fitted with a Wurster insert. The amount of granulating fluid, coating levels, curing time and formulation composition were varied to achieve CPT release with specific criteria to develop a preliminary formulation. The coated beads met all desired quality attributes in respect of micromeritic and flow properties, content uniformity and friability. Response Surface Methodology was used to further optimise the SR CPT formulation. The Plackett-Burman design was used for this process to produce an SR dosage form with desirable quality attributes achieved by altering formulation composition, extrusion-spheronisation variables and coating parameters. ANOVA data revealed significant responses for yield, aspect ratio, sphericity, coating efficiency and cumulative percent CPT released at 2 and 12 hours. Formulations in which the high molecular weight HPMC were used in increased concentrations resulted in the formation of a sticky wet mass and extrudate, resulting in a decrease in yield. The application of a permeable, but insoluble Surelease® coat onto the surface of the beads formed a barrier that complements the activity of the hydrophilic matrix in preventing rapid dissolution and retarding the release of CPT from the beads. The amount of CPT released over 12 hours revealed that increasing the Methocel® K100M content entrapped CPT and retained it more efficiently in the hydrated matrix, resulting in a slow rate of CPT release. In vitro release data were fitted to a number of models in an attempt to elucidate mechanistic aspects of transport processes specific to CPT from the coated bead formulations. The results of fitting data from optimised batches revealed that the goodness of fit based on the adjusted correlation coefficient ranged between 0.953 and 0.976 for the Higuchi model, indicating that diffusion is a predominant factor that controls CPT release from the coated beads. The results of fitting data to the Korsmeyer-Peppas model suggest that the mechanism of CPT release includes transport of the dissolution medium from the vessel reservoir into the core of the bead due to osmotic potential, dissolution of CPT, mass transfer of the dissolved CPT within the core, partitioning between the solution and polymeric film, mass transfer of dissolved CPT through the film to ultimately reach the bulk dissolution fluid. A SR CPT bead formulation that has potential for further development and optimisation for scaled-up production using RSM approaches and Design of Experiments such as CCD or Box-Behnken has been successfully developed and manufactured using extrusion, spheronisation and coating processes. Assessment of all batches of beads manufactured exhibited satisfactory to good flow properties and demonstrated SR profiles over 12 hours that met USP criteria for SR dosage forms.
- Full Text:
Diet of coastal filter feeders : impact of factors operating at different scales
- Authors: Puccinelli, Eleonora
- Date: 2015
- Subjects: Benthic animals -- Ecology -- South Africa , Benthic animals -- Nutrition
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5929 , http://hdl.handle.net/10962/d1017807
- Description: Benthic filter feeders have a key functional role in the dynamics of coastal food web as an intermediate trophic level and bioengineers. A wide variety of factors, operating across multiple spatial scales (e.g. hydrographic regime, human activities), can affect the composition of the water column and thus the availability of food for benthic populations. Food availability in turn affects the growth, reproductive rates and survival of benthic organisms, and consequently, can influence the functioning of the entire ecosystem. This study aims to evaluate how various environmental factors may modify the diet of intertidal filter feeders living along the South African coast. Specifically, the effects of biogeography, upwelling, urbanization and freshwater input on the dietary regimes of five species of filter feeders (two mussel and three barnacle species) were investigated using fatty acid (FA) and stable isotope (SI) analyses.Strong interspecific differences were found among the five species considered. However, all species responded to factors operating at large (100s km) and meso (10s- 100s km) scales (i.e. biogeography and upwelling respectively). The barnacles exhibit habitat segregation and showed different FA and SI signatures from each other, while the two mussel species, an invasive and native species that co-occur in the same mussel beds, had partially overlapping diets. Differences in their diets were found only using FA analysis, while their SI signatures differed on only one occasion. This highlights the importance of using the appropriate tool, and ideally combined techniques, to investigate diets.FA and SI signatures of all species considered changed among the three biographical provinces (west, south and east coasts of South Africa) exhibiting similar patterns that reflect the two oceanographic regimes that characterize the coastline: the eutrophic Benguela Current on the west coast and the oligotrophic Agulhas Current on the other two coasts. Upwelling had a significant effect on FA and SI signatures, with stronger effects on the west coast than the south coast. The results indicate that benthic filter feeders at upwelling areas consumed a mix of coastal macroalgal detritus and phytoplankton, which was probably brought onshore during downwelling events. At smaller spatialscales and using repeated sampling, the influence of upwelling on the west coast was found to be pervasive, rather than discrete, so that it may be more appropriate to categorize upwelling by referring to upwelling centres and downstream areas. SI underlined a significant effect of urbanization on the diet of filter feeders with an enrichment in the δ¹⁵N being characteristic of anthropogenic effect. Although a large number of rivers characterize the South African coast, no distinct effect of freshwater input was found for either the SI or FA signatures of the filter feeders. This contrasts with earlier work on demersal species and suggests that freshwater input does not significantly affect food availability for intertidal filter feeders, and that other factors (e.g. hydrogeography) are more important in determining the diet of these populations. These results highlight that environmental and anthropogenic factors operating at different spatial and temporal scales have a profound effect on benthic ecosystems, and that they control the relationship between primary production and primary consumers in coastal areas. Above all, this work highlights the importance of understanding the spatial and temporal scales at which different factors affect feeding regimes, and their critical role in coastal food webs.
- Full Text:
- Authors: Puccinelli, Eleonora
- Date: 2015
- Subjects: Benthic animals -- Ecology -- South Africa , Benthic animals -- Nutrition
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5929 , http://hdl.handle.net/10962/d1017807
- Description: Benthic filter feeders have a key functional role in the dynamics of coastal food web as an intermediate trophic level and bioengineers. A wide variety of factors, operating across multiple spatial scales (e.g. hydrographic regime, human activities), can affect the composition of the water column and thus the availability of food for benthic populations. Food availability in turn affects the growth, reproductive rates and survival of benthic organisms, and consequently, can influence the functioning of the entire ecosystem. This study aims to evaluate how various environmental factors may modify the diet of intertidal filter feeders living along the South African coast. Specifically, the effects of biogeography, upwelling, urbanization and freshwater input on the dietary regimes of five species of filter feeders (two mussel and three barnacle species) were investigated using fatty acid (FA) and stable isotope (SI) analyses.Strong interspecific differences were found among the five species considered. However, all species responded to factors operating at large (100s km) and meso (10s- 100s km) scales (i.e. biogeography and upwelling respectively). The barnacles exhibit habitat segregation and showed different FA and SI signatures from each other, while the two mussel species, an invasive and native species that co-occur in the same mussel beds, had partially overlapping diets. Differences in their diets were found only using FA analysis, while their SI signatures differed on only one occasion. This highlights the importance of using the appropriate tool, and ideally combined techniques, to investigate diets.FA and SI signatures of all species considered changed among the three biographical provinces (west, south and east coasts of South Africa) exhibiting similar patterns that reflect the two oceanographic regimes that characterize the coastline: the eutrophic Benguela Current on the west coast and the oligotrophic Agulhas Current on the other two coasts. Upwelling had a significant effect on FA and SI signatures, with stronger effects on the west coast than the south coast. The results indicate that benthic filter feeders at upwelling areas consumed a mix of coastal macroalgal detritus and phytoplankton, which was probably brought onshore during downwelling events. At smaller spatialscales and using repeated sampling, the influence of upwelling on the west coast was found to be pervasive, rather than discrete, so that it may be more appropriate to categorize upwelling by referring to upwelling centres and downstream areas. SI underlined a significant effect of urbanization on the diet of filter feeders with an enrichment in the δ¹⁵N being characteristic of anthropogenic effect. Although a large number of rivers characterize the South African coast, no distinct effect of freshwater input was found for either the SI or FA signatures of the filter feeders. This contrasts with earlier work on demersal species and suggests that freshwater input does not significantly affect food availability for intertidal filter feeders, and that other factors (e.g. hydrogeography) are more important in determining the diet of these populations. These results highlight that environmental and anthropogenic factors operating at different spatial and temporal scales have a profound effect on benthic ecosystems, and that they control the relationship between primary production and primary consumers in coastal areas. Above all, this work highlights the importance of understanding the spatial and temporal scales at which different factors affect feeding regimes, and their critical role in coastal food webs.
- Full Text:
DNA-based identification of forensically significant beetles from Southern Africa
- Authors: Collett, Isabel Judith
- Date: 2015
- Subjects: Carrion insects , Forensic entomology , Cleridae , Dermestidae , Silphidae , Staphylinidae , Scarabaeidae , Histeridae
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5923 , http://hdl.handle.net/10962/d1017801
- Description: Necrophilous insects, if correctly identified, can provide useful forensic information. Research in this area has focussed on flies and beetles remain comparatively under-studied, partly because some adult carrion beetles are difficult to identify morphologically, as are their juvenile stages, often requiring specialist expertise in both cases. Molecular taxonomy has been proposed as a solution to these problems. DNA “barcodes" are short fragments of mitochondrial cytochrome oxidase I (COI) DNA that are anticipated to delineate species. This approach is becoming increasingly popular, but has been met with varying enthusiasm from taxonomists. This thesis examines their use in identifying forensically significant beetles.The DNA barcodes of 234 specimens of 25 forensically significant southern African beetle species from seven families (Cleridae, Dermestidae, Silphidae, Staphylinidae, Scarabaeidae, Trogidae and Histeridae) were obtained. Thirty-three initial barcode amplification failures were overcome by using primers other than the standard Folmer pair, undermining the barcode concept’s hope of universal primers that would allow even non-specialists to produce barcodes. Another 150 specimens (64%) entirely failed to yield barcodes, including 18 fresh specimens of three species of Trogidae, implying another lack of universality of the barcoding protocol. The majority of the beetles clustered with confamilials on neighbour-joining and maximum likelihood trees, but 1.3% of the barcodes failed to cluster with their respective families, raising questions concerning the associating power of barcodes. The identification tools of the GenBank and BOLD on-line DNA sequence databases identified 21% of the specimens to the species level, 6% of them correctly. There was evidence of a paralogous sequence in the Cleridae that, while supporting identification now that it has been associated with a morphological identification, would hamper attempts at identification by clustering or phylogenetic analysis.Distance and haplotype network analyses of the barcodes of six widespread species showed that they are not geographically structured. Barcodes are thus unlikely to be indicators of the region of origin of a species and will not determine whether a corpse has been relocated after death. To assess whether a different mitochondrial DNA fragment might address (some of) these problems, a 2.2 kb fragment extending from the 5’ end of the COI gene to the 3’ end of the Cytochrome Oxidase II (COII) gene was analysed for nine species. It was found that, for Dermestidae, Scarabaeidae and Histeridae, higher degrees of diversity occurred downstreamof the barcode region, but the region of highest diversity in the Cleridae was in the barcode region. Thus, finding a more reliable fragment along the COI-COII region for each family may make robust and guaranteed DNA-based identification of these beetles more likely. The possibility of a forensic specimen being incorrectly or not identified based on its barcode alone exists in about 40% of cases, even with the new barcodes reported here. Forensic science sets a very high bar in assessing the performance of its techniques, and it is concluded that barcodes currently have unsettling failure rates as court-worthy evidence.
- Full Text:
- Authors: Collett, Isabel Judith
- Date: 2015
- Subjects: Carrion insects , Forensic entomology , Cleridae , Dermestidae , Silphidae , Staphylinidae , Scarabaeidae , Histeridae
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5923 , http://hdl.handle.net/10962/d1017801
- Description: Necrophilous insects, if correctly identified, can provide useful forensic information. Research in this area has focussed on flies and beetles remain comparatively under-studied, partly because some adult carrion beetles are difficult to identify morphologically, as are their juvenile stages, often requiring specialist expertise in both cases. Molecular taxonomy has been proposed as a solution to these problems. DNA “barcodes" are short fragments of mitochondrial cytochrome oxidase I (COI) DNA that are anticipated to delineate species. This approach is becoming increasingly popular, but has been met with varying enthusiasm from taxonomists. This thesis examines their use in identifying forensically significant beetles.The DNA barcodes of 234 specimens of 25 forensically significant southern African beetle species from seven families (Cleridae, Dermestidae, Silphidae, Staphylinidae, Scarabaeidae, Trogidae and Histeridae) were obtained. Thirty-three initial barcode amplification failures were overcome by using primers other than the standard Folmer pair, undermining the barcode concept’s hope of universal primers that would allow even non-specialists to produce barcodes. Another 150 specimens (64%) entirely failed to yield barcodes, including 18 fresh specimens of three species of Trogidae, implying another lack of universality of the barcoding protocol. The majority of the beetles clustered with confamilials on neighbour-joining and maximum likelihood trees, but 1.3% of the barcodes failed to cluster with their respective families, raising questions concerning the associating power of barcodes. The identification tools of the GenBank and BOLD on-line DNA sequence databases identified 21% of the specimens to the species level, 6% of them correctly. There was evidence of a paralogous sequence in the Cleridae that, while supporting identification now that it has been associated with a morphological identification, would hamper attempts at identification by clustering or phylogenetic analysis.Distance and haplotype network analyses of the barcodes of six widespread species showed that they are not geographically structured. Barcodes are thus unlikely to be indicators of the region of origin of a species and will not determine whether a corpse has been relocated after death. To assess whether a different mitochondrial DNA fragment might address (some of) these problems, a 2.2 kb fragment extending from the 5’ end of the COI gene to the 3’ end of the Cytochrome Oxidase II (COII) gene was analysed for nine species. It was found that, for Dermestidae, Scarabaeidae and Histeridae, higher degrees of diversity occurred downstreamof the barcode region, but the region of highest diversity in the Cleridae was in the barcode region. Thus, finding a more reliable fragment along the COI-COII region for each family may make robust and guaranteed DNA-based identification of these beetles more likely. The possibility of a forensic specimen being incorrectly or not identified based on its barcode alone exists in about 40% of cases, even with the new barcodes reported here. Forensic science sets a very high bar in assessing the performance of its techniques, and it is concluded that barcodes currently have unsettling failure rates as court-worthy evidence.
- Full Text:
Drought responses of selected C₄ photosynthetic NADP-Me and NAD-Me Panicoideae and Aristidoideae grasses
- Authors: Venter, Nicolaas
- Date: 2015
- Subjects: Aristida , Panicum , Switchgrass , Grasses -- Effect of drought on , Grasses -- Phylogeny , Photosynthesis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4272 , http://hdl.handle.net/10962/d1018549
- Description: Grass species within South Africa show a photosynthetic subtype and phylogenetic response to rainfall gradients, with Panicoideae species (NADP-Me and NAD-Me) inhabiting mesic environments, while Aristidoideae species (NADP-Me) inhabit more arid environments. It is predicted that climate change will alter rainfall patterns within southern Africa, which could have implications for grassland distributions and functional composition. Globally, and in South Africa, species distributions indicates that NAD-Me species have a preference for more arid environments, but this may be complicated by phylogeny as most NAD-Me species belong to the Chloridoideae subfamily. Additionally, differences in the metabolism and energetic requirements of different carboxylation types are expected to confer different ecological advantages, such as drought tolerance, but the role of these different pathways is not well understood. Based on natural distribution and photosynthetic subtype differences, it was hypothesised that Panicoideae NADP-Me species would be less drought tolerant than Panicoideae NAD-Me and Aristidoideae NADP-Me species and that subtypes and lineages would show different drought recovery rates. Furthermore, drought sensitivity would be of a metabolic and not a stomatal origin and plants that maintained favourable leaf water status would be more drought tolerant and recover faster. This was tested experimentally by comparing Panicoideae species (NADP-Me and NAD-Me) and NADP-Me species (Panicoideae and Aristidoideae). Plants were subjected to a progressive 58 day drought period and a recovery phase where gas exchange, chlorophyll fluorescence and leaf water relations were measured at select intervals. In conjunction with this, a rapid drought experiment was performed on Zea mays (NADP-Me: Panicoideae) plants where similar parameters were measured. Photosynthetic drought and recovery responses showed both a subtype and phylogenetic response. Panicoideae species were less drought tolerant than Aristidoideae species, although Panicoideae NAD-Me showed better recovery rates than Panicoideae NADP-Me species, while Aristidoideae species recovered the quickest. Panicoideae NAD-Me and Aristidoideae species maintained higher leaf water status during drought which contributed to the maintenance of PSII integrity and thus facilitated rapid photosynthetic recovery. During drought Panicoideae species showed greater metabolic limitations over Aristidoideae species and for the first time, lower metabolic limitations were associated with osmotic adjustment. This is a novel finding whereby osmotic adjustment and the subsequent maintenance of leaf water are key to preventing metabolic limitations of photosynthesis in C₄ grasses. Results from the Z. mays rapid drought study showed the limitations to photosynthesis were exclusively metabolic and unlikely to be a direct consequence of turgor loss. It was apparent that the response to drought was stronger amongst lineages, as NADP-Me species from different subfamilies showed a significant difference in drought tolerances. Aristidoideae species’ exceptional drought tolerance and predicted increased aridification could favour these species over Panicoideae species under future climates.
- Full Text:
- Authors: Venter, Nicolaas
- Date: 2015
- Subjects: Aristida , Panicum , Switchgrass , Grasses -- Effect of drought on , Grasses -- Phylogeny , Photosynthesis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4272 , http://hdl.handle.net/10962/d1018549
- Description: Grass species within South Africa show a photosynthetic subtype and phylogenetic response to rainfall gradients, with Panicoideae species (NADP-Me and NAD-Me) inhabiting mesic environments, while Aristidoideae species (NADP-Me) inhabit more arid environments. It is predicted that climate change will alter rainfall patterns within southern Africa, which could have implications for grassland distributions and functional composition. Globally, and in South Africa, species distributions indicates that NAD-Me species have a preference for more arid environments, but this may be complicated by phylogeny as most NAD-Me species belong to the Chloridoideae subfamily. Additionally, differences in the metabolism and energetic requirements of different carboxylation types are expected to confer different ecological advantages, such as drought tolerance, but the role of these different pathways is not well understood. Based on natural distribution and photosynthetic subtype differences, it was hypothesised that Panicoideae NADP-Me species would be less drought tolerant than Panicoideae NAD-Me and Aristidoideae NADP-Me species and that subtypes and lineages would show different drought recovery rates. Furthermore, drought sensitivity would be of a metabolic and not a stomatal origin and plants that maintained favourable leaf water status would be more drought tolerant and recover faster. This was tested experimentally by comparing Panicoideae species (NADP-Me and NAD-Me) and NADP-Me species (Panicoideae and Aristidoideae). Plants were subjected to a progressive 58 day drought period and a recovery phase where gas exchange, chlorophyll fluorescence and leaf water relations were measured at select intervals. In conjunction with this, a rapid drought experiment was performed on Zea mays (NADP-Me: Panicoideae) plants where similar parameters were measured. Photosynthetic drought and recovery responses showed both a subtype and phylogenetic response. Panicoideae species were less drought tolerant than Aristidoideae species, although Panicoideae NAD-Me showed better recovery rates than Panicoideae NADP-Me species, while Aristidoideae species recovered the quickest. Panicoideae NAD-Me and Aristidoideae species maintained higher leaf water status during drought which contributed to the maintenance of PSII integrity and thus facilitated rapid photosynthetic recovery. During drought Panicoideae species showed greater metabolic limitations over Aristidoideae species and for the first time, lower metabolic limitations were associated with osmotic adjustment. This is a novel finding whereby osmotic adjustment and the subsequent maintenance of leaf water are key to preventing metabolic limitations of photosynthesis in C₄ grasses. Results from the Z. mays rapid drought study showed the limitations to photosynthesis were exclusively metabolic and unlikely to be a direct consequence of turgor loss. It was apparent that the response to drought was stronger amongst lineages, as NADP-Me species from different subfamilies showed a significant difference in drought tolerances. Aristidoideae species’ exceptional drought tolerance and predicted increased aridification could favour these species over Panicoideae species under future climates.
- Full Text:
E-commerce: the challenge of virtual permanent establishments
- Adlkofer, Michelle Leigh, Venter, Michelle
- Authors: Adlkofer, Michelle Leigh , Venter, Michelle
- Date: 2015
- Subjects: Organisation for Economic Co-operation and Development , Electronic commerce , Electronic commerce -- Taxation , Double taxation -- Treaties , Globalization
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:921 , http://hdl.handle.net/10962/d1020057
- Description: The continued growth of world commerce has led to the advance of the permanent establishment principles. These principles are, however, constantly challenged by the developments of e-commerce. This thesis considers the taxing of a permanent establishment and the influence of e-commerce on the concept of a permanent establishment. In 2000, the Organisation for Economic Co-operation and Development (“OECD”) developed and introduced guidelines on how to deal with e-commerce in the context of a permanent establishment. Since the OECD guidelines on e-commerce were issued, the permanent establishment principles have come under further scrutiny. The latest development came about in 2013 with the release of the Base Erosion and Profit Shifting (“BEPS”) Action Plan. This Action Plan addresses the intention of the OECD to deal with the taxing of the digital economy. With the development of e-commerce and the result of e-commerce creating intangible boundaries between countries, the concept of a virtual permanent establishment has emerged. This has resulted in the need to tax a presence of an enterprise in a jurisdiction where no actual physical connection can be established. Various authors have made suggestions on how to ensure that an economy in which business is being carried on is correctly compensated for in the form of taxes. The source of income is the driving force for the imposition of taxation today. The main goal of this thesis was to explore the alignment of the concepts of a permanent establishment and e-commerce in the digital economy. This study therefore examined the concepts of both permanent establishments and e-commerce, and explored authors’ views and suggestions on how to deal with the inter-related effects of these two concepts. The relevant Action Points in the OECD Action Plan were also considered. , Maiden name: Venter, Michelle
- Full Text:
- Authors: Adlkofer, Michelle Leigh , Venter, Michelle
- Date: 2015
- Subjects: Organisation for Economic Co-operation and Development , Electronic commerce , Electronic commerce -- Taxation , Double taxation -- Treaties , Globalization
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:921 , http://hdl.handle.net/10962/d1020057
- Description: The continued growth of world commerce has led to the advance of the permanent establishment principles. These principles are, however, constantly challenged by the developments of e-commerce. This thesis considers the taxing of a permanent establishment and the influence of e-commerce on the concept of a permanent establishment. In 2000, the Organisation for Economic Co-operation and Development (“OECD”) developed and introduced guidelines on how to deal with e-commerce in the context of a permanent establishment. Since the OECD guidelines on e-commerce were issued, the permanent establishment principles have come under further scrutiny. The latest development came about in 2013 with the release of the Base Erosion and Profit Shifting (“BEPS”) Action Plan. This Action Plan addresses the intention of the OECD to deal with the taxing of the digital economy. With the development of e-commerce and the result of e-commerce creating intangible boundaries between countries, the concept of a virtual permanent establishment has emerged. This has resulted in the need to tax a presence of an enterprise in a jurisdiction where no actual physical connection can be established. Various authors have made suggestions on how to ensure that an economy in which business is being carried on is correctly compensated for in the form of taxes. The source of income is the driving force for the imposition of taxation today. The main goal of this thesis was to explore the alignment of the concepts of a permanent establishment and e-commerce in the digital economy. This study therefore examined the concepts of both permanent establishments and e-commerce, and explored authors’ views and suggestions on how to deal with the inter-related effects of these two concepts. The relevant Action Points in the OECD Action Plan were also considered. , Maiden name: Venter, Michelle
- Full Text:
Earnings quality and equity returns : evidence of the accrual anomaly from the South African equity market
- Authors: Lutchmun, Thashveen
- Date: 2015
- Subjects: Earnings management -- South Africa , Accounting -- Standards
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:915 , http://hdl.handle.net/10962/d1017537
- Description: A key incentive for accounting research is to provide evidence on the usefulness of earnings in making economic decisions. Of particular interest over the last two decades is the issue of the quality of financial reporting, specifically the quality of earnings, given the number of global financial scandals reported during that period. The quality of earnings is driven by the choices, estimates and judgments that the accounting standards make available to managers in order to portray the firm’s economic position and performance in a timely and credible manner. However, this leeway in financial reporting also creates opportunities for earnings management. The objective of this thesis is firstly to establish whether earnings manipulation has had the ability to predict cross-sectional returns in South Africa during the 2007-2014 period. In other words, the purpose of this thesis is to find evidence whether the market reacts to earnings management practices, as measured by accruals, and rewards high earnings quality companies with higher equity returns (a process known as the accrual anomaly). The timeframe selected for the research encompasses the global financial crisis, a period in which accounting manipulation incentives are likely to be strong. Secondly, this study attempts to establish the presence of the accrual anomaly amongst growth and value firms. The motivations for earnings management of the former are expected to be strong. Securities are allocated to portfolios according to accruals and the subsequent equity returns are analysed cross-sectionally to establish the existence of the accrual anomaly and hence assessing the usefulness of earnings manipulation in predicting equity returns. To provide evidence for the presence of the accrual anomaly amongst growth and value shares, securities are independently allocated to portfolios according to their book-to-market ratio and accruals and a cross-sectional analysis is performed on their subsequent equity returns. In order to increase the robustness of the tests, two measures of accruals are used: a balance sheet approach and a cash flow measure. Evidence is provided for the presence of the accrual anomaly among South African listed companies for the balance sheet measure of accruals but not the cash flow approach. Whilst the accrual anomaly is significantly present in a growth-neutral-value construct, statistical significance is not established when growth and value shares are considered individually.
- Full Text:
- Authors: Lutchmun, Thashveen
- Date: 2015
- Subjects: Earnings management -- South Africa , Accounting -- Standards
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:915 , http://hdl.handle.net/10962/d1017537
- Description: A key incentive for accounting research is to provide evidence on the usefulness of earnings in making economic decisions. Of particular interest over the last two decades is the issue of the quality of financial reporting, specifically the quality of earnings, given the number of global financial scandals reported during that period. The quality of earnings is driven by the choices, estimates and judgments that the accounting standards make available to managers in order to portray the firm’s economic position and performance in a timely and credible manner. However, this leeway in financial reporting also creates opportunities for earnings management. The objective of this thesis is firstly to establish whether earnings manipulation has had the ability to predict cross-sectional returns in South Africa during the 2007-2014 period. In other words, the purpose of this thesis is to find evidence whether the market reacts to earnings management practices, as measured by accruals, and rewards high earnings quality companies with higher equity returns (a process known as the accrual anomaly). The timeframe selected for the research encompasses the global financial crisis, a period in which accounting manipulation incentives are likely to be strong. Secondly, this study attempts to establish the presence of the accrual anomaly amongst growth and value firms. The motivations for earnings management of the former are expected to be strong. Securities are allocated to portfolios according to accruals and the subsequent equity returns are analysed cross-sectionally to establish the existence of the accrual anomaly and hence assessing the usefulness of earnings manipulation in predicting equity returns. To provide evidence for the presence of the accrual anomaly amongst growth and value shares, securities are independently allocated to portfolios according to their book-to-market ratio and accruals and a cross-sectional analysis is performed on their subsequent equity returns. In order to increase the robustness of the tests, two measures of accruals are used: a balance sheet approach and a cash flow measure. Evidence is provided for the presence of the accrual anomaly among South African listed companies for the balance sheet measure of accruals but not the cash flow approach. Whilst the accrual anomaly is significantly present in a growth-neutral-value construct, statistical significance is not established when growth and value shares are considered individually.
- Full Text:
Electrode surface modification using metallophthalocyanines and metal nanoparticles : electrocatalytic activity
- Authors: Maringa, Audacity
- Date: 2015
- Subjects: Phthalocyanines , Nanoparticles , Electrocatalysis , Scanning electron microscopy , X-ray photoelectron spectroscopy , Electrochemistry , Scanning electrochemical microscopy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4541 , http://hdl.handle.net/10962/d1017921
- Description: Metallophthalocyanines and metal nanoparticles were successfully synthesized and applied for the electrooxidation of amitrole, nitrite and hydrazine individually or when employed together. The synthesized materials were characterized using the following techniques: predominantly scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), electrochemistry and scanning electrochemical microscopy (SECM). Different electrode modification methods were used to modify the glassy carbon substrates. The methods include adsorption, electrodeposition, electropolymerization and click chemistry. Modifying the glassy carbon substrate with MPc (electropolymerization) followed by metal nanoparticles (electrodeposition) or vice versa, made a hybrid modified surface that had efficient electron transfer. This was confirmed by electrochemical impedance studies with voltammetry measurements having lower detection potentials for the analytes. This work also describes for the first time the micropatterning of the glassy carbon substrate using the SECM tip. The substrate was electrografted with 4-azidobenzenediazonium salt and then the click reaction was performed using ethynylferrocene facilitated by Cu⁺ produced at the SECM tip. The SECM imaging was then used to show the clicked spot.
- Full Text:
- Authors: Maringa, Audacity
- Date: 2015
- Subjects: Phthalocyanines , Nanoparticles , Electrocatalysis , Scanning electron microscopy , X-ray photoelectron spectroscopy , Electrochemistry , Scanning electrochemical microscopy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4541 , http://hdl.handle.net/10962/d1017921
- Description: Metallophthalocyanines and metal nanoparticles were successfully synthesized and applied for the electrooxidation of amitrole, nitrite and hydrazine individually or when employed together. The synthesized materials were characterized using the following techniques: predominantly scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), electrochemistry and scanning electrochemical microscopy (SECM). Different electrode modification methods were used to modify the glassy carbon substrates. The methods include adsorption, electrodeposition, electropolymerization and click chemistry. Modifying the glassy carbon substrate with MPc (electropolymerization) followed by metal nanoparticles (electrodeposition) or vice versa, made a hybrid modified surface that had efficient electron transfer. This was confirmed by electrochemical impedance studies with voltammetry measurements having lower detection potentials for the analytes. This work also describes for the first time the micropatterning of the glassy carbon substrate using the SECM tip. The substrate was electrografted with 4-azidobenzenediazonium salt and then the click reaction was performed using ethynylferrocene facilitated by Cu⁺ produced at the SECM tip. The SECM imaging was then used to show the clicked spot.
- Full Text:
Eliciting and combining expert opinion : an overview and comparison of methods
- Authors: Chinyamakobvu, Mutsa Carole
- Date: 2015
- Subjects: Decision making -- Statistical methods , Expertise , Bayesian statistical decision theory , Statistical decision , Delphi method , Paired comparisons (Statistics)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5579 , http://hdl.handle.net/10962/d1017827
- Description: Decision makers have long relied on experts to inform their decision making. Expert judgment analysis is a way to elicit and combine the opinions of a group of experts to facilitate decision making. The use of expert judgment is most appropriate when there is a lack of data for obtaining reasonable statistical results. The experts are asked for advice by one or more decision makers who face a specific real decision problem. The decision makers are outside the group of experts and are jointly responsible and accountable for the decision and committed to finding solutions that everyone can live with. The emphasis is on the decision makers learning from the experts. The focus of this thesis is an overview and comparison of the various elicitation and combination methods available. These include the traditional committee method, the Delphi method, the paired comparisons method, the negative exponential model, Cooke’s classical model, the histogram technique, using the Dirichlet distribution in the case of a set of uncertain proportions which must sum to one, and the employment of overfitting. The supra Bayes approach, the determination of weights for the experts, and combining the opinions of experts where each opinion is associated with a confidence level that represents the expert’s conviction of his own judgment are also considered.
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- Authors: Chinyamakobvu, Mutsa Carole
- Date: 2015
- Subjects: Decision making -- Statistical methods , Expertise , Bayesian statistical decision theory , Statistical decision , Delphi method , Paired comparisons (Statistics)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5579 , http://hdl.handle.net/10962/d1017827
- Description: Decision makers have long relied on experts to inform their decision making. Expert judgment analysis is a way to elicit and combine the opinions of a group of experts to facilitate decision making. The use of expert judgment is most appropriate when there is a lack of data for obtaining reasonable statistical results. The experts are asked for advice by one or more decision makers who face a specific real decision problem. The decision makers are outside the group of experts and are jointly responsible and accountable for the decision and committed to finding solutions that everyone can live with. The emphasis is on the decision makers learning from the experts. The focus of this thesis is an overview and comparison of the various elicitation and combination methods available. These include the traditional committee method, the Delphi method, the paired comparisons method, the negative exponential model, Cooke’s classical model, the histogram technique, using the Dirichlet distribution in the case of a set of uncertain proportions which must sum to one, and the employment of overfitting. The supra Bayes approach, the determination of weights for the experts, and combining the opinions of experts where each opinion is associated with a confidence level that represents the expert’s conviction of his own judgment are also considered.
- Full Text: