An investigation of how grade 10 learners make sense of concepts on refraction of light through exploring their cultural beliefs/everyday experiences about the rainbow : a case study
- Homateni, Rauha Kau Ndahalomwenyo
- Authors: Homateni, Rauha Kau Ndahalomwenyo
- Date: 2013
- Subjects: Science -- Study and teaching (Secondary) -- Namibia Light -- Study and teaching Light -- Study and teaching
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1827 , http://hdl.handle.net/10962/d1003713
- Description: This study took place at a private high school in the Kavango region with my 32 grade 10B learners as the research participants. Its objective was to investigate how the grade 10 learners make sense of concepts on refraction of light through exploring their cultural beliefs/everyday experiences about the rainbow. This research study was essentially triggered by my own classroom experience of teaching the topic on refraction of light. In order to achieve the goal of this research, a qualitative case study located within an interpretive paradigm was adopted. To gather data I used multiple data gathering techniques such as brainstorming session, learners conducting interviews in the community, practical activities and focus group interviews. This resulted in descriptive data that qualified to be analyzed in a qualitative way. The themes that emerged from the generated data were coded using upper letter cases and various colours. A methodological triangulation was employed by using multiple data generation techniques. Member checking during focus group interviews also ensured validity in this case study. The findings of this study revealed that the use of learners’ cultural beliefs/everyday experiences can be used to enhance learner engagement, meaning making and conceptual development during the science lessons. In addition, the ways in which practical activities are designed and presented to learners in the science classroom determine learners’ participation and conceptual attainment. Therefore, based on my research findings, I recommend that teachers need to be trained to be able to elicit and integrate learners’ cultural beliefs/everyday experiences in conjunction with hands-on practical activities which focus on conceptual development during their science lessons. However, although this study had many benefits, it also showed that it is not easy to close the gap between learners’ prior everyday knowledge and school science. This warrants further research.
- Full Text:
- Authors: Homateni, Rauha Kau Ndahalomwenyo
- Date: 2013
- Subjects: Science -- Study and teaching (Secondary) -- Namibia Light -- Study and teaching Light -- Study and teaching
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1827 , http://hdl.handle.net/10962/d1003713
- Description: This study took place at a private high school in the Kavango region with my 32 grade 10B learners as the research participants. Its objective was to investigate how the grade 10 learners make sense of concepts on refraction of light through exploring their cultural beliefs/everyday experiences about the rainbow. This research study was essentially triggered by my own classroom experience of teaching the topic on refraction of light. In order to achieve the goal of this research, a qualitative case study located within an interpretive paradigm was adopted. To gather data I used multiple data gathering techniques such as brainstorming session, learners conducting interviews in the community, practical activities and focus group interviews. This resulted in descriptive data that qualified to be analyzed in a qualitative way. The themes that emerged from the generated data were coded using upper letter cases and various colours. A methodological triangulation was employed by using multiple data generation techniques. Member checking during focus group interviews also ensured validity in this case study. The findings of this study revealed that the use of learners’ cultural beliefs/everyday experiences can be used to enhance learner engagement, meaning making and conceptual development during the science lessons. In addition, the ways in which practical activities are designed and presented to learners in the science classroom determine learners’ participation and conceptual attainment. Therefore, based on my research findings, I recommend that teachers need to be trained to be able to elicit and integrate learners’ cultural beliefs/everyday experiences in conjunction with hands-on practical activities which focus on conceptual development during their science lessons. However, although this study had many benefits, it also showed that it is not easy to close the gap between learners’ prior everyday knowledge and school science. This warrants further research.
- Full Text:
An investigation of online threat awareness and behaviour patterns amongst secondary school learners
- Authors: Irwin, Michael Padric
- Date: 2013 , 2013-04-29
- Subjects: Computer security -- South Africa -- Grahamstown , Risk perception -- South Africa -- Grahamstown , High school students -- South Africa -- Grahamstown , Communication -- Sex differences -- South Africa -- Grahamstown , Internet and teenagers -- South Africa -- Grahamstown , Internet and teenagers -- Risk assessment -- South Africa -- Grahamstown , Internet -- Safety measures -- South Africa -- Grahamstown , Online social networks -- Social aspects -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4576 , http://hdl.handle.net/10962/d1002965 , Computer security -- South Africa -- Grahamstown , Risk perception -- South Africa -- Grahamstown , High school students -- South Africa -- Grahamstown , Communication -- Sex differences -- South Africa -- Grahamstown , Internet and teenagers -- South Africa -- Grahamstown , Internet and teenagers -- Risk assessment -- South Africa -- Grahamstown , Internet -- Safety measures -- South Africa -- Grahamstown , Online social networks -- Social aspects -- South Africa -- Grahamstown
- Description: The research area of this work is online threat awareness within an information security context. The research was carried out on secondary school learners at boarding schools in Grahamstown. The participating learners were in Grades 8 to 12. The goals of the research included determining the actual levels of awareness, the difference between these and self-perceived levels of the participants, the assessment of risk in terms of online behaviour, and the determination of any gender differences in the answers provided by the respondents. A review of relevant literature and similar studies was carried out, and data was collected from the participating schools via an online questionnaire. This data was analysed and discussed within the frameworks of awareness of threats, online privacy social media, sexting, cyberbullying and password habits. The concepts of information security and online privacy are present throughout these discussion chapters, providing the themes for linking the discussion points together. The results of this research show that the respondents have a high level of risk. This is due to the gaps identified in actual awareness and perception, as well as the exhibition of online behaviour patterns that are considered high risk. A strong need for the construction and adoption of threat awareness programmes by these and other schools is identified, as are areas of particular need for inclusion in such programmes. Some gender differences are present, but not to the extent that, there is as significant difference between male and female respondents in terms of overall awareness, knowledge and behaviour.
- Full Text:
An investigation of online threat awareness and behaviour patterns amongst secondary school learners
- Authors: Irwin, Michael Padric
- Date: 2013 , 2013-04-29
- Subjects: Computer security -- South Africa -- Grahamstown , Risk perception -- South Africa -- Grahamstown , High school students -- South Africa -- Grahamstown , Communication -- Sex differences -- South Africa -- Grahamstown , Internet and teenagers -- South Africa -- Grahamstown , Internet and teenagers -- Risk assessment -- South Africa -- Grahamstown , Internet -- Safety measures -- South Africa -- Grahamstown , Online social networks -- Social aspects -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4576 , http://hdl.handle.net/10962/d1002965 , Computer security -- South Africa -- Grahamstown , Risk perception -- South Africa -- Grahamstown , High school students -- South Africa -- Grahamstown , Communication -- Sex differences -- South Africa -- Grahamstown , Internet and teenagers -- South Africa -- Grahamstown , Internet and teenagers -- Risk assessment -- South Africa -- Grahamstown , Internet -- Safety measures -- South Africa -- Grahamstown , Online social networks -- Social aspects -- South Africa -- Grahamstown
- Description: The research area of this work is online threat awareness within an information security context. The research was carried out on secondary school learners at boarding schools in Grahamstown. The participating learners were in Grades 8 to 12. The goals of the research included determining the actual levels of awareness, the difference between these and self-perceived levels of the participants, the assessment of risk in terms of online behaviour, and the determination of any gender differences in the answers provided by the respondents. A review of relevant literature and similar studies was carried out, and data was collected from the participating schools via an online questionnaire. This data was analysed and discussed within the frameworks of awareness of threats, online privacy social media, sexting, cyberbullying and password habits. The concepts of information security and online privacy are present throughout these discussion chapters, providing the themes for linking the discussion points together. The results of this research show that the respondents have a high level of risk. This is due to the gaps identified in actual awareness and perception, as well as the exhibition of online behaviour patterns that are considered high risk. A strong need for the construction and adoption of threat awareness programmes by these and other schools is identified, as are areas of particular need for inclusion in such programmes. Some gender differences are present, but not to the extent that, there is as significant difference between male and female respondents in terms of overall awareness, knowledge and behaviour.
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An investigation of teachers' mathematical task selection in the Zambia context
- Authors: Kangwa, Evaristo
- Date: 2013
- Subjects: Mathematics -- Study and teaching
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1384 , http://hdl.handle.net/10962/d1001512
- Description: This research sought to investigate the sources and type of tasks used in the teaching of trigonometry in Zambia’s secondary schools, and to investigate the criteria used and decisions made by teachers in their selection and implementation of tasks. The study was conducted in three different school types located in high cost, medium cost and low cost respectively. One participant was chosen from each of the different categories of schools. The research was located within an interpretive paradigm. Data were collected through semi-structured interviews, lesson observations and document analysis which include: lesson plans for five consecutive days, pupils’ activity books and three textbooks predominantly used by the teachers. Document analysis was informed by the task analysis guide and essential themes which were used to tease out teachers’ task practice with regard to criteria used and decisions made in the selection and implementation of tasks. Essential themes that were qualitatively established were validated and explicated by the qualitative analysis. The findings of the study indicate that teachers picked tasks from prescribed textbooks. The study further suggests that teachers selected a mix of low and high level tasks, procedures without connections and procedures with connections tasks to be specific. There were no memorisations and doing mathematics tasks. Their choice of tasks was based on the purpose for which the task was intended. Some tasks were selected for the purpose of practicing the procedures and skills, other tasks for the promotion conceptual development. Most of high level tasks decline to low level tasks during implementation. The findings also indicate that teachers selected and implemented a variety of tasks and concepts. Furthermore, teachers presented tasks in various forms of representations and in a variety of ways. However, the results of this study could not be generalized because of the small sample involved. The results presented reflect the views and task practices of the target group. A possibility for future study would be to consider a large population, drawn across the country.
- Full Text:
- Authors: Kangwa, Evaristo
- Date: 2013
- Subjects: Mathematics -- Study and teaching
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1384 , http://hdl.handle.net/10962/d1001512
- Description: This research sought to investigate the sources and type of tasks used in the teaching of trigonometry in Zambia’s secondary schools, and to investigate the criteria used and decisions made by teachers in their selection and implementation of tasks. The study was conducted in three different school types located in high cost, medium cost and low cost respectively. One participant was chosen from each of the different categories of schools. The research was located within an interpretive paradigm. Data were collected through semi-structured interviews, lesson observations and document analysis which include: lesson plans for five consecutive days, pupils’ activity books and three textbooks predominantly used by the teachers. Document analysis was informed by the task analysis guide and essential themes which were used to tease out teachers’ task practice with regard to criteria used and decisions made in the selection and implementation of tasks. Essential themes that were qualitatively established were validated and explicated by the qualitative analysis. The findings of the study indicate that teachers picked tasks from prescribed textbooks. The study further suggests that teachers selected a mix of low and high level tasks, procedures without connections and procedures with connections tasks to be specific. There were no memorisations and doing mathematics tasks. Their choice of tasks was based on the purpose for which the task was intended. Some tasks were selected for the purpose of practicing the procedures and skills, other tasks for the promotion conceptual development. Most of high level tasks decline to low level tasks during implementation. The findings also indicate that teachers selected and implemented a variety of tasks and concepts. Furthermore, teachers presented tasks in various forms of representations and in a variety of ways. However, the results of this study could not be generalized because of the small sample involved. The results presented reflect the views and task practices of the target group. A possibility for future study would be to consider a large population, drawn across the country.
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An investigation of the discursive construction of the Tanganyika-Zanzibar Union as nation in the Union Day coverage in The Citizen and Daily News newspapers from 2005 to 2011
- Authors: Dotto, Paul Casmir Kuhenga
- Date: 2013
- Subjects: Newspapers -- Research -- Tanzania , Press and politics -- Tanzania , Tanzania -- Politics and government -- 1964- , Zanzibar -- Politics and government -- 1964- , Press , Daily News , The Citizen , Union Day , Nation building
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:3412 , http://hdl.handle.net/10962/d1001843
- Description: This study is concerned with the constructions of the Tanzanian nation in the press. It has confined its focus, first, to the coverage from 2005 to 2011 on Union Day that marks the Union between Tanganyika and Zanzibar and the formation of the United Republic of Tanzania and, second, to two prominent Tanzanian newspapers, namely the state-owned Daily News, and the privately-owned The Citizen on Union Day. As the Union remains a contentious issue, the relevance of this research relates to the press’s considerable power to shape understandings and influence attitudes. The study works within a broad cultural and media studies framework and is informed by a constructionist approach to representation and to culture, and to nation in particular. It also draws of journalistic theories of agenda-setting and the normative roles of the press to probe the agendas set by the press on Union Day and to interrogate how the two newspapers construct and frame the Union of Tanganyika and Zanzibar as nation. The research responds to the question: ‘How has the Tanganyika-Zanzibar Union been represented in The Citizen and Daily News newspapers from 2005 to 2011?’ It employs quantitative and qualitative (thematic) content analysis to investigate the coverage in the editorials and feature articles of The Citizen and Daily News newspapers on Union Day (26 April) of 2005 to 2011. This study finds that the government-owned newspaper, Daily News, publishes more articles related to Union on Union Day than the privately-owned, The Citizen and collaborates more determinedly with the state in the process of constructing the nation. However, both newspapers adopt a collaborative role consistent with the development journalism tradition that endorses an informal partnership between media and the state in the process of development (Christians et al, 2009:201). Both publications tend to emphasise the hegemonic ideology pertaining to Union while giving limited attention to challenges to such constructions. While both newspapers do identify certain problems of the Union and thus exercise a monitorial role to varying extents, it is apparent that the press in Tanzania tends to be largely acritical, perhaps attributable to a long period under single party rule
- Full Text:
- Authors: Dotto, Paul Casmir Kuhenga
- Date: 2013
- Subjects: Newspapers -- Research -- Tanzania , Press and politics -- Tanzania , Tanzania -- Politics and government -- 1964- , Zanzibar -- Politics and government -- 1964- , Press , Daily News , The Citizen , Union Day , Nation building
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:3412 , http://hdl.handle.net/10962/d1001843
- Description: This study is concerned with the constructions of the Tanzanian nation in the press. It has confined its focus, first, to the coverage from 2005 to 2011 on Union Day that marks the Union between Tanganyika and Zanzibar and the formation of the United Republic of Tanzania and, second, to two prominent Tanzanian newspapers, namely the state-owned Daily News, and the privately-owned The Citizen on Union Day. As the Union remains a contentious issue, the relevance of this research relates to the press’s considerable power to shape understandings and influence attitudes. The study works within a broad cultural and media studies framework and is informed by a constructionist approach to representation and to culture, and to nation in particular. It also draws of journalistic theories of agenda-setting and the normative roles of the press to probe the agendas set by the press on Union Day and to interrogate how the two newspapers construct and frame the Union of Tanganyika and Zanzibar as nation. The research responds to the question: ‘How has the Tanganyika-Zanzibar Union been represented in The Citizen and Daily News newspapers from 2005 to 2011?’ It employs quantitative and qualitative (thematic) content analysis to investigate the coverage in the editorials and feature articles of The Citizen and Daily News newspapers on Union Day (26 April) of 2005 to 2011. This study finds that the government-owned newspaper, Daily News, publishes more articles related to Union on Union Day than the privately-owned, The Citizen and collaborates more determinedly with the state in the process of constructing the nation. However, both newspapers adopt a collaborative role consistent with the development journalism tradition that endorses an informal partnership between media and the state in the process of development (Christians et al, 2009:201). Both publications tend to emphasise the hegemonic ideology pertaining to Union while giving limited attention to challenges to such constructions. While both newspapers do identify certain problems of the Union and thus exercise a monitorial role to varying extents, it is apparent that the press in Tanzania tends to be largely acritical, perhaps attributable to a long period under single party rule
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An investigation on how grade 8 learners make sens of static electricity through exploring their cultural beliefs and experiences about lightning: a case study
- Nanghonga, Ottilie Mwanyenenange
- Authors: Nanghonga, Ottilie Mwanyenenange
- Date: 2013
- Subjects: Science -- Study and teaching (Secondary) -- Namibia Electrostatics -- Study and teaching (Secondary) -- Namibia Lightning -- Study and teaching (Secondary) -- Namibia , Static electricity , Cultural beliefs , Science -- Study and teaching (Secondary) -- Namibia , Electrostatics -- Study and teaching (Secondary) -- Namibia , Lightning -- Study and teaching (Secondary) -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1387 , http://hdl.handle.net/10962/d1001537
- Description: Lightning as a natural phenomenon is shallowly presented in the Namibian curriculum documents such as the syllabus and textbooks. This gap in curriculum triggered my interest to investigate whether learners’ meaning-making in static electricity was enabled or constrained by elicitation and integration of their cultural beliefs and experiences about lightning and by their practical activities. This study was conducted with my grade 8 learners at the school where I am currently teaching. The school is located in a rural area in Ohangwena region in Northern Namibia. The study is situated within an interpretive paradigm. Within the interpretive paradigm, a qualitative case study approach was adopted. I considered this methodological orientation appropriate in this study as it allowed me to use the following data gathering methods: document analysis, brainstorming, discussions and presentations, semi-structured interview, focus group interview, observation and an assessment test. Multiple methods to gather data were used for triangulation and validation purposes. For data analysis purposes, the data sets were colour-coded to derive themes and analytical statements. Ethical considerations were also taken seriously in this study and all participants gave consent. An analysis of data revealed that there is no learning objective or basic competence in the Namibian Physical Science syllabus for grade 8-10 that requires learners to bring in their cultural beliefs and experiences, in particular, about lightning. Yet the study revealed that learners possess a lot of prior everyday scientific and non-scientific knowledge and experiences about lightning that they had acquired from their communities. Also, mobilization of learners' everyday knowledge and experiences about lightning enabled learner engagement during the science lessons. Likewise, engaging learners in practical activities in static electricity helped them to make meaning of scientific concepts. Based on my research findings, I therefore, recommend that learners' prior everyday knowledge and experiences about lightning should be incorporated during teaching and learning of the topic on static electricity.
- Full Text:
- Authors: Nanghonga, Ottilie Mwanyenenange
- Date: 2013
- Subjects: Science -- Study and teaching (Secondary) -- Namibia Electrostatics -- Study and teaching (Secondary) -- Namibia Lightning -- Study and teaching (Secondary) -- Namibia , Static electricity , Cultural beliefs , Science -- Study and teaching (Secondary) -- Namibia , Electrostatics -- Study and teaching (Secondary) -- Namibia , Lightning -- Study and teaching (Secondary) -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1387 , http://hdl.handle.net/10962/d1001537
- Description: Lightning as a natural phenomenon is shallowly presented in the Namibian curriculum documents such as the syllabus and textbooks. This gap in curriculum triggered my interest to investigate whether learners’ meaning-making in static electricity was enabled or constrained by elicitation and integration of their cultural beliefs and experiences about lightning and by their practical activities. This study was conducted with my grade 8 learners at the school where I am currently teaching. The school is located in a rural area in Ohangwena region in Northern Namibia. The study is situated within an interpretive paradigm. Within the interpretive paradigm, a qualitative case study approach was adopted. I considered this methodological orientation appropriate in this study as it allowed me to use the following data gathering methods: document analysis, brainstorming, discussions and presentations, semi-structured interview, focus group interview, observation and an assessment test. Multiple methods to gather data were used for triangulation and validation purposes. For data analysis purposes, the data sets were colour-coded to derive themes and analytical statements. Ethical considerations were also taken seriously in this study and all participants gave consent. An analysis of data revealed that there is no learning objective or basic competence in the Namibian Physical Science syllabus for grade 8-10 that requires learners to bring in their cultural beliefs and experiences, in particular, about lightning. Yet the study revealed that learners possess a lot of prior everyday scientific and non-scientific knowledge and experiences about lightning that they had acquired from their communities. Also, mobilization of learners' everyday knowledge and experiences about lightning enabled learner engagement during the science lessons. Likewise, engaging learners in practical activities in static electricity helped them to make meaning of scientific concepts. Based on my research findings, I therefore, recommend that learners' prior everyday knowledge and experiences about lightning should be incorporated during teaching and learning of the topic on static electricity.
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An investigation on how learners may use multiple representations in a social interaction to promote learning of percentages and fractions: a case study
- Authors: Ngola-Kazumba, Maria
- Date: 2013
- Subjects: Fractions -- Study and teaching (Secondary) -- Namibia -- Case studies Percentage -- Study and teaching (Secondary) -- Namibia -- Case studies Mathematical notation -- Study and teaching (Secondary) -- Namibia Mathematics -- Study and teaching (Secondary) -- Namibia Experiential learning -- Namibia Education, Secondary -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1890 , http://hdl.handle.net/10962/d1006057
- Description: The study examined the use of multiple representations such as the real world, written symbols, spoken symbols, diagrams and manipulatives by learners to promote the learning of percentages and fractions through social interaction. This investigation was carried out through a teaching and learning programme which was developed and implemented by me, the researcher. The effect of the implemented programme was the main focus of the research. The qualitative study was oriented in the interpretive paradigm – a paradigm that seeks to understand the meaning attached to human actions. Twenty learners participated in the implementation of the programme and 9 learners were selected for focus group interviews. The purpose of the interviews was to explore learners' understanding and feelings about the use of multiple representations in the learning of percentages and fractions through social interactions. The other tools employed in this study were pre-and-post diagnostic tests, observations, learners' work and a journal. The pre-test was used to determine learners' prior knowledge for the program design and implementation, while the post-test and learners' work were used to analyze the effect of the programme. Observations were used to investigate how multiple representations promoted or did not promote the learning of percentages and fractions. The teacher's journal was to record and reflect on any relevant information gathered on each lesson observed. The data shows that the effective use of multiple representations helped learners learn the concept of percentages and fractions better. Learners were able to look at representations in useful ways; multiple representations made some aspects of the concept clear; and multiple representations enabled learners to correct errors. Through the interaction between the teacher and learners, the following was found: all the learners changed words to change focus; learners made links between multiple representations; the learners deepened their concepts of percentages and fractions; learners could convert between fractions using multiple representations; learners could work out percentages of a quantity; and learners could express one quantity as a percentage of another. Furthermore, through the interaction between learners and learners all learners could identify more equivalent fractions of an initial fraction which was given to them; and they could increase and decrease a quantity by a given percentage. On the basis of this research, it can be concluded that the programme promoted the learning of percentages and fractions through three effective methodologies. The first methodology consisted of the effective use of multiple representations; the second methodology concerned the interaction between the teacher and learner during the learning process and the last methodology related to the interaction between the learners - interactions that were not strongly mediated by the teacher. I would recommend that teachers use these three effective approaches when teaching percentages and fractions to promote the learning of the concepts.
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- Authors: Ngola-Kazumba, Maria
- Date: 2013
- Subjects: Fractions -- Study and teaching (Secondary) -- Namibia -- Case studies Percentage -- Study and teaching (Secondary) -- Namibia -- Case studies Mathematical notation -- Study and teaching (Secondary) -- Namibia Mathematics -- Study and teaching (Secondary) -- Namibia Experiential learning -- Namibia Education, Secondary -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1890 , http://hdl.handle.net/10962/d1006057
- Description: The study examined the use of multiple representations such as the real world, written symbols, spoken symbols, diagrams and manipulatives by learners to promote the learning of percentages and fractions through social interaction. This investigation was carried out through a teaching and learning programme which was developed and implemented by me, the researcher. The effect of the implemented programme was the main focus of the research. The qualitative study was oriented in the interpretive paradigm – a paradigm that seeks to understand the meaning attached to human actions. Twenty learners participated in the implementation of the programme and 9 learners were selected for focus group interviews. The purpose of the interviews was to explore learners' understanding and feelings about the use of multiple representations in the learning of percentages and fractions through social interactions. The other tools employed in this study were pre-and-post diagnostic tests, observations, learners' work and a journal. The pre-test was used to determine learners' prior knowledge for the program design and implementation, while the post-test and learners' work were used to analyze the effect of the programme. Observations were used to investigate how multiple representations promoted or did not promote the learning of percentages and fractions. The teacher's journal was to record and reflect on any relevant information gathered on each lesson observed. The data shows that the effective use of multiple representations helped learners learn the concept of percentages and fractions better. Learners were able to look at representations in useful ways; multiple representations made some aspects of the concept clear; and multiple representations enabled learners to correct errors. Through the interaction between the teacher and learners, the following was found: all the learners changed words to change focus; learners made links between multiple representations; the learners deepened their concepts of percentages and fractions; learners could convert between fractions using multiple representations; learners could work out percentages of a quantity; and learners could express one quantity as a percentage of another. Furthermore, through the interaction between learners and learners all learners could identify more equivalent fractions of an initial fraction which was given to them; and they could increase and decrease a quantity by a given percentage. On the basis of this research, it can be concluded that the programme promoted the learning of percentages and fractions through three effective methodologies. The first methodology consisted of the effective use of multiple representations; the second methodology concerned the interaction between the teacher and learner during the learning process and the last methodology related to the interaction between the learners - interactions that were not strongly mediated by the teacher. I would recommend that teachers use these three effective approaches when teaching percentages and fractions to promote the learning of the concepts.
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An overview of normative frameworks for the protection of development-induced IDPs in Kenya.
- Authors: Juma, Laurence
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/127112 , vital:35957 , https://doi.org/10.1163/17087384-12342016
- Description: Based on the assumption that development induced displacement brings new challenges that the existing protection frameworks may not be aptly suited to deal with, this article analyses how the existing laws have met this challenge and the prospects for further improvement. While its focus is on Kenya, it evaluates the normative quality of protection and standards offered by regional instruments against the existing, as well emerging, parameters for implementation at the domestic level. In this regard, the article examines the propriety of Kenya’s newly promulgated law on internal displacement in providing for protection for the development induced IDPs, the implementation programme that it establishes and its prospects for furthering the vision of the UN Guiding Principles on Internally Displaced and other regional instruments.
- Full Text:
- Authors: Juma, Laurence
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/127112 , vital:35957 , https://doi.org/10.1163/17087384-12342016
- Description: Based on the assumption that development induced displacement brings new challenges that the existing protection frameworks may not be aptly suited to deal with, this article analyses how the existing laws have met this challenge and the prospects for further improvement. While its focus is on Kenya, it evaluates the normative quality of protection and standards offered by regional instruments against the existing, as well emerging, parameters for implementation at the domestic level. In this regard, the article examines the propriety of Kenya’s newly promulgated law on internal displacement in providing for protection for the development induced IDPs, the implementation programme that it establishes and its prospects for furthering the vision of the UN Guiding Principles on Internally Displaced and other regional instruments.
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An Unprecedented 'Precedent'?: Phodiclinics (Pty) Ltd v Pinehaven Private Hospital (Pty) Ltd (594/2010)[2011] ZASCA163 (28 September 2011); 2011 4 All SA 331 (SCA)
- Authors: Glover, Graham B
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69950 , vital:29598 , https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2364288
- Description: There are some fundamental underlying requirements that need to be in place for a system of precedent to operate. Of these I wish to isolate two that are germane to this note. The first is that court decisions (especially those in which a written judgment is handed down) need to be clearly reasoned and logically articulated to be understandable, effective and to have value in a system of precedent that finds its ultimate lodestar in the rule of law. There is no constitutional or statutory requirement that a court in all cases must furnish reasons, or even written reasons, for its decision But the practice of doing so, the Constitutional Court has said, supports the rule of law, ensuring that judicial decision-making does not occur in a manner that is arbitrary, and ensures that judges may be held accountable for their decisions. The second requirement is a technical rule – the rule of majority: if the case is heard by a full bench, and where differing opinions are handed down by the judges hearing the case, the ratio decidendi can only be identified from those judges whose reasoning is in the majority.
- Full Text: false
- Authors: Glover, Graham B
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69950 , vital:29598 , https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2364288
- Description: There are some fundamental underlying requirements that need to be in place for a system of precedent to operate. Of these I wish to isolate two that are germane to this note. The first is that court decisions (especially those in which a written judgment is handed down) need to be clearly reasoned and logically articulated to be understandable, effective and to have value in a system of precedent that finds its ultimate lodestar in the rule of law. There is no constitutional or statutory requirement that a court in all cases must furnish reasons, or even written reasons, for its decision But the practice of doing so, the Constitutional Court has said, supports the rule of law, ensuring that judicial decision-making does not occur in a manner that is arbitrary, and ensures that judges may be held accountable for their decisions. The second requirement is a technical rule – the rule of majority: if the case is heard by a full bench, and where differing opinions are handed down by the judges hearing the case, the ratio decidendi can only be identified from those judges whose reasoning is in the majority.
- Full Text: false
Analysing learning at the interface of scientific and traditional ecological knowledge in a mangrove ecosystem restoration scenario in the eastern coast of Tanzania
- Sabai, Daniel, Sisitka, Heila
- Authors: Sabai, Daniel , Sisitka, Heila
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/127179 , vital:35974 , https://doi.org/10.2478/trser-2013-0027
- Description: Records from community-based coastal management initiatives indicate that local communities who are key actors in activities that aim at safeguarding the health status of terrestrial and marine ecosystems face a lot of challenges associated with adapting andapplying indicators that are scientifically abstracted and methodologically too reified, given varying social, contextual and technical conditions prevailing amongst them. This paper brings into view possible challenges of adapting and applying scientific indicators in community-based monitoring of mangrove ecosystem and suggests a new approach that may lead to development of indicators which are less reified, more congruent to users (coastal communities) and likely to attract a wider social learning in the mangroverestoration context. It also sets a bridge for scientific institutions (including universities), tounderstand various social, cultural and contextual needs that determine epistemological access between them and local communities, which need to be addressed prior to engaging targetcommunities in participatory monitoring programmes.The paper attempts to analyse learning at the interface of knowledge that scientific institutions produce and the potential knowledge that exists in local context (traditional ecological knowledge) for purposes of widening and improving knowledge sharing and safeguarding the health status of mangrove species and fisheries that use them as key habitats. The paper stems from a study which employs processes of abstraction and experiential learning techniques such as Experiential Learning Intervention Workshop carried out in 2012,to unlock knowledge that local communities have, as an input for underlabouring existing scientific indicators in the eastern coast of Tanzania.It brings into view the need to consider contextual realities on ground, the level of education that the participating group has, the minimum level of participation that is required, structures that govern coastal monitoring practices at local level and the need for scientific institutions to consider the knowledge that local people have as an input for enhancing or improving coastal monitoring, especially monitoring of mangrove and fishery resources. The paper finally comes up with a framework of indicators which is regarded by coastal communities as being less reified, more contextually and culturally congruent and which can easily be used in detecting environmental trends, threats, changes and conditions of mangrove and fisheries resources, and attract wider social learning processes.
- Full Text:
- Authors: Sabai, Daniel , Sisitka, Heila
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/127179 , vital:35974 , https://doi.org/10.2478/trser-2013-0027
- Description: Records from community-based coastal management initiatives indicate that local communities who are key actors in activities that aim at safeguarding the health status of terrestrial and marine ecosystems face a lot of challenges associated with adapting andapplying indicators that are scientifically abstracted and methodologically too reified, given varying social, contextual and technical conditions prevailing amongst them. This paper brings into view possible challenges of adapting and applying scientific indicators in community-based monitoring of mangrove ecosystem and suggests a new approach that may lead to development of indicators which are less reified, more congruent to users (coastal communities) and likely to attract a wider social learning in the mangroverestoration context. It also sets a bridge for scientific institutions (including universities), tounderstand various social, cultural and contextual needs that determine epistemological access between them and local communities, which need to be addressed prior to engaging targetcommunities in participatory monitoring programmes.The paper attempts to analyse learning at the interface of knowledge that scientific institutions produce and the potential knowledge that exists in local context (traditional ecological knowledge) for purposes of widening and improving knowledge sharing and safeguarding the health status of mangrove species and fisheries that use them as key habitats. The paper stems from a study which employs processes of abstraction and experiential learning techniques such as Experiential Learning Intervention Workshop carried out in 2012,to unlock knowledge that local communities have, as an input for underlabouring existing scientific indicators in the eastern coast of Tanzania.It brings into view the need to consider contextual realities on ground, the level of education that the participating group has, the minimum level of participation that is required, structures that govern coastal monitoring practices at local level and the need for scientific institutions to consider the knowledge that local people have as an input for enhancing or improving coastal monitoring, especially monitoring of mangrove and fishery resources. The paper finally comes up with a framework of indicators which is regarded by coastal communities as being less reified, more contextually and culturally congruent and which can easily be used in detecting environmental trends, threats, changes and conditions of mangrove and fisheries resources, and attract wider social learning processes.
- Full Text:
Analysis of protein thermostability enhancing factors in industrially important thermus bacteria species
- Kumwenda, Benjamin, Litthauer, Derek, Tastan Bishop, Özlem, Reva, Oleg
- Authors: Kumwenda, Benjamin , Litthauer, Derek , Tastan Bishop, Özlem , Reva, Oleg
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123085 , vital:35404 , https://doi.10.4137/EBO.S12539
- Description: Elucidation of evolutionary factors that enhance protein thermostability is a critical problem and was the focus of this work on Thermus species. Pairs of orthologous sequences of T. scotoductus SA-01 and T. thermophilus HB27, with the largest negative minimum folding energy (MFE) as predicted by the UNAFold algorithm, were statistically analyzed. Favored substitutions of amino acids residues and their properties were determined. Substitutions were analyzed in modeled protein structures to determine their locations and contribution to energy differences using PyMOL and FoldX programs respectively. Dominant trends in amino acid substitutions consistent with differences in thermostability between orthologous sequences were observed. T. thermophilus thermophilic proteins showed an increase in non-polar, tiny, and charged amino acids. An abundance of alanine substituted by serine and threonine, as well as arginine substituted by glutamine and lysine was observed in T. thermophilus HB27. Structural comparison showed that stabilizing mutations occurred on surfaces and loops in protein structures.
- Full Text:
- Authors: Kumwenda, Benjamin , Litthauer, Derek , Tastan Bishop, Özlem , Reva, Oleg
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123085 , vital:35404 , https://doi.10.4137/EBO.S12539
- Description: Elucidation of evolutionary factors that enhance protein thermostability is a critical problem and was the focus of this work on Thermus species. Pairs of orthologous sequences of T. scotoductus SA-01 and T. thermophilus HB27, with the largest negative minimum folding energy (MFE) as predicted by the UNAFold algorithm, were statistically analyzed. Favored substitutions of amino acids residues and their properties were determined. Substitutions were analyzed in modeled protein structures to determine their locations and contribution to energy differences using PyMOL and FoldX programs respectively. Dominant trends in amino acid substitutions consistent with differences in thermostability between orthologous sequences were observed. T. thermophilus thermophilic proteins showed an increase in non-polar, tiny, and charged amino acids. An abundance of alanine substituted by serine and threonine, as well as arginine substituted by glutamine and lysine was observed in T. thermophilus HB27. Structural comparison showed that stabilizing mutations occurred on surfaces and loops in protein structures.
- Full Text:
Analysis of the implementation of corporate level strategy in a South Afircan furniture retailer
- Authors: Nkatsha, Thembinkosi Sydney
- Date: 2013
- Subjects: Reengineering (Management) , Consolidation and merger of corporations -- South Africa -- Case studies , Organizational change -- Management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:856 , http://hdl.handle.net/10962/d1018272
- Description: [Integrative Summary] This study is situated in the complex field of change management, and strategy execution. The study focuses on the corporate level restructuring of Ellerine Holdings Limited (EHL), subsequent to its acquisition by the micro lending financial institution African Bank Investments Limited (ABIL). The interest of the researcher was aroused by the uniqueness of the relationship. This was the first of its kind in a South African context, where a banker owned a furniture retailer. The restructuring was undertaken shortly after the acquisition. This research paper adopted a case study approach, in describing the restructuring initiative that took place in EHL, focusing on the period between January 2008 and the end of 2010/ 11 financial year on the 30th of September 2011. The case captures the significant phases of the restructuring including a background of (1) the protagonist, Toni Fourie (Chief Executive Officer), (2) EHL as the researched company, (3) the industry it operates in, and (4) the case content. Brief teaching notes have been provided to explain the teaching value of the case and to assist with its delivery in the classroom. Attention is drawn to a presentation by the protagonist in November 2011, named 'A CEO Insight' where he gave an overview and insights of the road travelled in restructuring Ellerine Holdings Limited, and more importantly highlights the following about the purpose and nature of the restructuring of the organisation. • A plan to change the way the industry works. • The creation of a profitable, stand-alone retail business through: o The sale of two companies, the closure of two companies and consolidating from thirteen to six brands. o Separating financial services from retail. o Moving the financial services component to African Bank, also a subsidiary of ABIL. o Redesigning the credit model. o Completion of twelve system changes. • Over R600million reduction in cost • A place where people want to work. The restructuring outlined above represents a major shake-up in many aspects of the corporation. The main challenge for Toni Fourie and his team was: how best could they restructure EHL to extract synergies between their two subsidiaries Ellerine Holdings Limited & African Bank to increase shareholders ' value at Group level. The case seeks to describe this in detail. The overarching strategy underpinning the restructuring of the researched corporation is premised on the price volume elasticity equation, by reducing the cost of credit, thereby driving pricing down within the brands, and facilitating more people having access to affordable credit. The case study of the restructuring is presented in Section 1. A review of relevant literature on strategy implementation is presented in Section 2, focusing on restructuring. Successful implementation of strategies only takes place with structures that are developed by organisations to support the achievement of their strategic objectives. Organisational architecture and design have a critical role to play in the execution of organisational strategies. Nadler and Tushman (1978) emphasise the importance of congruence in the organisational design, for the organization to not only deliver superior results but to sustain them over a period of time. Research by Okumus (2005) seems to tell us that the lack of credible framework to implement strategy, has contributed the high failure rate of strategy initiatives. Although this is a strategy implementation case, it also touches on aspects of leadership - mainly the architectural role - and the role, or influence of strategic leadership, in restructuring the corporation. The results of this research paper were achieved by following a specific research methodology. The aim of the research was to analyse the restructuring of the researched company at corporate level, having the following objectives in mind; • Understanding the strategy. • Analysing the design decisions in the light of the strategy chosen by the top management of Ellerine Holdings Limited. • Analysing what monitoring and control measures had been designed to facilitate the corporate restructuring. Data was collected through documentation of the corporation that was made available to the researcher on request, as well as those that are in the public domain, and an interview with the CEO of the researched company. The interview was conducted after analysing the documentation (Hakim, 2000). The Methodology is detailed in Section 3. The researcher hopes that the case study will contribute to learning about business leadership and strategic management. The case should develop an understanding of the complexities related to strategy execution at corporate level, particularly the restructuring aspect of it.
- Full Text:
- Authors: Nkatsha, Thembinkosi Sydney
- Date: 2013
- Subjects: Reengineering (Management) , Consolidation and merger of corporations -- South Africa -- Case studies , Organizational change -- Management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:856 , http://hdl.handle.net/10962/d1018272
- Description: [Integrative Summary] This study is situated in the complex field of change management, and strategy execution. The study focuses on the corporate level restructuring of Ellerine Holdings Limited (EHL), subsequent to its acquisition by the micro lending financial institution African Bank Investments Limited (ABIL). The interest of the researcher was aroused by the uniqueness of the relationship. This was the first of its kind in a South African context, where a banker owned a furniture retailer. The restructuring was undertaken shortly after the acquisition. This research paper adopted a case study approach, in describing the restructuring initiative that took place in EHL, focusing on the period between January 2008 and the end of 2010/ 11 financial year on the 30th of September 2011. The case captures the significant phases of the restructuring including a background of (1) the protagonist, Toni Fourie (Chief Executive Officer), (2) EHL as the researched company, (3) the industry it operates in, and (4) the case content. Brief teaching notes have been provided to explain the teaching value of the case and to assist with its delivery in the classroom. Attention is drawn to a presentation by the protagonist in November 2011, named 'A CEO Insight' where he gave an overview and insights of the road travelled in restructuring Ellerine Holdings Limited, and more importantly highlights the following about the purpose and nature of the restructuring of the organisation. • A plan to change the way the industry works. • The creation of a profitable, stand-alone retail business through: o The sale of two companies, the closure of two companies and consolidating from thirteen to six brands. o Separating financial services from retail. o Moving the financial services component to African Bank, also a subsidiary of ABIL. o Redesigning the credit model. o Completion of twelve system changes. • Over R600million reduction in cost • A place where people want to work. The restructuring outlined above represents a major shake-up in many aspects of the corporation. The main challenge for Toni Fourie and his team was: how best could they restructure EHL to extract synergies between their two subsidiaries Ellerine Holdings Limited & African Bank to increase shareholders ' value at Group level. The case seeks to describe this in detail. The overarching strategy underpinning the restructuring of the researched corporation is premised on the price volume elasticity equation, by reducing the cost of credit, thereby driving pricing down within the brands, and facilitating more people having access to affordable credit. The case study of the restructuring is presented in Section 1. A review of relevant literature on strategy implementation is presented in Section 2, focusing on restructuring. Successful implementation of strategies only takes place with structures that are developed by organisations to support the achievement of their strategic objectives. Organisational architecture and design have a critical role to play in the execution of organisational strategies. Nadler and Tushman (1978) emphasise the importance of congruence in the organisational design, for the organization to not only deliver superior results but to sustain them over a period of time. Research by Okumus (2005) seems to tell us that the lack of credible framework to implement strategy, has contributed the high failure rate of strategy initiatives. Although this is a strategy implementation case, it also touches on aspects of leadership - mainly the architectural role - and the role, or influence of strategic leadership, in restructuring the corporation. The results of this research paper were achieved by following a specific research methodology. The aim of the research was to analyse the restructuring of the researched company at corporate level, having the following objectives in mind; • Understanding the strategy. • Analysing the design decisions in the light of the strategy chosen by the top management of Ellerine Holdings Limited. • Analysing what monitoring and control measures had been designed to facilitate the corporate restructuring. Data was collected through documentation of the corporation that was made available to the researcher on request, as well as those that are in the public domain, and an interview with the CEO of the researched company. The interview was conducted after analysing the documentation (Hakim, 2000). The Methodology is detailed in Section 3. The researcher hopes that the case study will contribute to learning about business leadership and strategic management. The case should develop an understanding of the complexities related to strategy execution at corporate level, particularly the restructuring aspect of it.
- Full Text:
Ancient and modern hybridization between Lucilia sericata and L. cuprina (Diptera: Calliphoridae)
- Williams, Kirstin A, Villet, Martin H
- Authors: Williams, Kirstin A , Villet, Martin H
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442633 , vital:74017 , 10.14411/eje.2013.029
- Description: There are important but inconsistent differences in breeding site preference between the blow flies Lucilia sericata (Meigen, 1826) and L. cuprina (Wiedemann, 1830)(Diptera: Calliphoridae) that have significance for medical and veterinary science. These inconsistencies might arise from hybridisation. The species are difficult to distinguish using external morphology, although the male genitalia are distinctive and there are reliable molecular markers. Molecular evidence of modern hybridisation, derived from a newly developed nuclear marker, the period (per) gene, is presented here. This has implications for identifications of these species based on mtDNA, and may lead to an explanation of the medical and veterinary anomalies noted in these species.
- Full Text:
- Authors: Williams, Kirstin A , Villet, Martin H
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442633 , vital:74017 , 10.14411/eje.2013.029
- Description: There are important but inconsistent differences in breeding site preference between the blow flies Lucilia sericata (Meigen, 1826) and L. cuprina (Wiedemann, 1830)(Diptera: Calliphoridae) that have significance for medical and veterinary science. These inconsistencies might arise from hybridisation. The species are difficult to distinguish using external morphology, although the male genitalia are distinctive and there are reliable molecular markers. Molecular evidence of modern hybridisation, derived from a newly developed nuclear marker, the period (per) gene, is presented here. This has implications for identifications of these species based on mtDNA, and may lead to an explanation of the medical and veterinary anomalies noted in these species.
- Full Text:
Application of bidentate N,N'-donor extractants in the hydrometallurgical separation of base metals from an acidic sulfate medium
- Authors: Okewole, Adeleye Ishola
- Date: 2013
- Subjects: Hydrometallurgy Sulfates Nanofibers Electrospinning Sorbents Extraction (Chemistry) Solvent extraction Stereochemistry
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4281 , http://hdl.handle.net/10962/d1002610
- Description: Bidentate imidazole-based extractants, 1-octylimidazole-2-aldoxime (OIMOX) and 1-octyl-2-(2′-pyridyl)imidazole (OPIM), along with dinonylnaphthalene sulfonic acid (DNNSA) as a synergist, were investigated as potential selective extractants for Cu²⁺and Ni²⁺ respectively from base metals in a solvent extraction system. The study was extended to evaluate the sorption and separation of Ni²⁺ from other base metals in a solid-solution system using microspherical Merrifield resins and nanofibers functionalized with 2,2′-pyridylimidazole. Copper was effectively separated with OIMOX and DNNSA as extractants from nickel with ΔpH½ ≈1.05 and the extraction order of Cu²⁺ > Ni²⁺ > Zn²⁺ > Cd²⁺> Co²⁺ was achieved as a function of pH. At pH 1.65 the extracted copper, from a synthetic mixture of the base metals reached 90.13(±0.90)%, and through a two-step extraction process 98.22(±0.29)% copper was recovered with negligible nickel and cobalt impurities. Stripping of the copper from the loaded organic phase using TraceSelect sulphuric acid at pH 0.35 yielded 96.60(±0.44)% of the loaded quantity after the second stage of stripping. The separation of Ni²⁺ from the borderline and hard acids; Co²⁺, Cu²⁺, Zn²⁺, Fe2²⁺, Fe²⁺, Mn²⁺, Mg2²⁺ and Ca²⁺ at a pH range of 0.5-3.5 with OPIM and DNNSA was acvieved to the tune of a ΔpH½≈ 1.6 with respect to cobalt from a sulfate and sulfate/chloride media. A three-stage counter-current extraction of Ni²⁺, at the optimized pH of 1.89, from a synthetic mixture of Ni²⁺, Co²⁺ and Cu²⁺, yielded 99.01(±1.79)%. The total co-extracted Cu²⁺ was 48.72(±0.24)% of the original quantity in the mixture, and it was 19.85(±0.28%) for Co²⁺. The co-extracted Cu²⁺ was scrubbed off from the loaded organic phase at pH≈8.5 by using an ammonium buffer, while co-extracted Co²⁺ was selectively and quantitatively stripped with H₂SO₄ at pH 1.64. The total recovery of Ni²⁺ by stripping at pH 0.32 was 94.05(±1.70)%. In the solid-liquid system, Ni²⁺ was separated from Co²⁺, Cu²⁺, and Fe²⁺ with the microspherical resins funtionalised with 2,2′-pyridylimidazole by a separation factor (β) in the range 22-45. Electrospun nanofibers as sorbents yielded high sorption capacity in the range of 0.97 - 1.45 mmol.g⁻¹ for the same metals ions. Thus, 1-octylimidazole-2-aldoxime (OIMOX), and1-octyl-2-(2′-pyridyl)imidazole (OPIM) can be effectively utilized alongside DNNSA as a co-extractant in the separation of Cu²⁺ and Ni²⁺ respectively from base metals in acidic sulfate medium in a solvent extraction process, and the latter as a selective ligand in the solid-liquid separation of Ni²⁺ from Co²⁺, Cu²⁺, and Fe²⁺.
- Full Text:
- Authors: Okewole, Adeleye Ishola
- Date: 2013
- Subjects: Hydrometallurgy Sulfates Nanofibers Electrospinning Sorbents Extraction (Chemistry) Solvent extraction Stereochemistry
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4281 , http://hdl.handle.net/10962/d1002610
- Description: Bidentate imidazole-based extractants, 1-octylimidazole-2-aldoxime (OIMOX) and 1-octyl-2-(2′-pyridyl)imidazole (OPIM), along with dinonylnaphthalene sulfonic acid (DNNSA) as a synergist, were investigated as potential selective extractants for Cu²⁺and Ni²⁺ respectively from base metals in a solvent extraction system. The study was extended to evaluate the sorption and separation of Ni²⁺ from other base metals in a solid-solution system using microspherical Merrifield resins and nanofibers functionalized with 2,2′-pyridylimidazole. Copper was effectively separated with OIMOX and DNNSA as extractants from nickel with ΔpH½ ≈1.05 and the extraction order of Cu²⁺ > Ni²⁺ > Zn²⁺ > Cd²⁺> Co²⁺ was achieved as a function of pH. At pH 1.65 the extracted copper, from a synthetic mixture of the base metals reached 90.13(±0.90)%, and through a two-step extraction process 98.22(±0.29)% copper was recovered with negligible nickel and cobalt impurities. Stripping of the copper from the loaded organic phase using TraceSelect sulphuric acid at pH 0.35 yielded 96.60(±0.44)% of the loaded quantity after the second stage of stripping. The separation of Ni²⁺ from the borderline and hard acids; Co²⁺, Cu²⁺, Zn²⁺, Fe2²⁺, Fe²⁺, Mn²⁺, Mg2²⁺ and Ca²⁺ at a pH range of 0.5-3.5 with OPIM and DNNSA was acvieved to the tune of a ΔpH½≈ 1.6 with respect to cobalt from a sulfate and sulfate/chloride media. A three-stage counter-current extraction of Ni²⁺, at the optimized pH of 1.89, from a synthetic mixture of Ni²⁺, Co²⁺ and Cu²⁺, yielded 99.01(±1.79)%. The total co-extracted Cu²⁺ was 48.72(±0.24)% of the original quantity in the mixture, and it was 19.85(±0.28%) for Co²⁺. The co-extracted Cu²⁺ was scrubbed off from the loaded organic phase at pH≈8.5 by using an ammonium buffer, while co-extracted Co²⁺ was selectively and quantitatively stripped with H₂SO₄ at pH 1.64. The total recovery of Ni²⁺ by stripping at pH 0.32 was 94.05(±1.70)%. In the solid-liquid system, Ni²⁺ was separated from Co²⁺, Cu²⁺, and Fe²⁺ with the microspherical resins funtionalised with 2,2′-pyridylimidazole by a separation factor (β) in the range 22-45. Electrospun nanofibers as sorbents yielded high sorption capacity in the range of 0.97 - 1.45 mmol.g⁻¹ for the same metals ions. Thus, 1-octylimidazole-2-aldoxime (OIMOX), and1-octyl-2-(2′-pyridyl)imidazole (OPIM) can be effectively utilized alongside DNNSA as a co-extractant in the separation of Cu²⁺ and Ni²⁺ respectively from base metals in acidic sulfate medium in a solvent extraction process, and the latter as a selective ligand in the solid-liquid separation of Ni²⁺ from Co²⁺, Cu²⁺, and Fe²⁺.
- Full Text:
Applying a student curriculum discourse in higher education teaching and learning
- Mndzebele, Samuel, McKenna, Sioux
- Authors: Mndzebele, Samuel , McKenna, Sioux
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187417 , vital:44633 , xlink:href="https://doi.org/10.1080/18146627.2013.786210"
- Description: Indications of poor quality in students’ written work necessitated the need for deeper investigations aimed at designing and applying appropriate teaching/learning and assessment innovations in the course curriculum. The project-exercise engaged a conceptual-explorative approach through: reviews/investigations; educational diagnosis; design/application of innovations and evaluation processes. In addition to other challenges, diagnosed problems included: students’ ignorance on key curriculum components; imbalance in teaching/learning and assessment tasks engaging all 3-learning domains; less intensiveness of the e-learning mode; and superficial formative feedback. Included a “Student-Curriculum-Discourse” self-tutorial guide, and tasks alignment of the teaching/learning and assessment. Learners’ performance can be improved through a curriculum-discourse self-tutorial exercise, complemented with: intellectual, social, experiential, and emotional structures. Both educators and learners share specific responsibilities in the teaching/learning environment. There is need to expand/probe the theoretical dimension within which the on-line distance education occurs.
- Full Text:
- Authors: Mndzebele, Samuel , McKenna, Sioux
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187417 , vital:44633 , xlink:href="https://doi.org/10.1080/18146627.2013.786210"
- Description: Indications of poor quality in students’ written work necessitated the need for deeper investigations aimed at designing and applying appropriate teaching/learning and assessment innovations in the course curriculum. The project-exercise engaged a conceptual-explorative approach through: reviews/investigations; educational diagnosis; design/application of innovations and evaluation processes. In addition to other challenges, diagnosed problems included: students’ ignorance on key curriculum components; imbalance in teaching/learning and assessment tasks engaging all 3-learning domains; less intensiveness of the e-learning mode; and superficial formative feedback. Included a “Student-Curriculum-Discourse” self-tutorial guide, and tasks alignment of the teaching/learning and assessment. Learners’ performance can be improved through a curriculum-discourse self-tutorial exercise, complemented with: intellectual, social, experiential, and emotional structures. Both educators and learners share specific responsibilities in the teaching/learning environment. There is need to expand/probe the theoretical dimension within which the on-line distance education occurs.
- Full Text:
Aspects of isiXhosa poetry with special reference to poems produced about women
- Jadezweni, Mhlobo Wabantwana
- Authors: Jadezweni, Mhlobo Wabantwana
- Date: 2013
- Subjects: Laudatory poetry, Xhosa African poetry (English) -- History and criticism Women in literature Women and literature -- South Africa African poetry -- Women authors
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3616 , http://hdl.handle.net/10962/d1006364
- Description: This study investigates the use of modern and izibongo (praise poetry) techniques in representing women in selected isiXhosa poems. The main interest of the study is to determine whether the same techniques to depict men are used when writing about women. It is also the interest of the study to ascertain how gender issues are dealt with in the selected poems. Seminal studies on izibongo by eminent scholars in this field show a serious lack of critique and little recognition of women in African languages’ poetry in general and in isiXhosa in particular. Pioneering studies in Nguni poetry about women have thus recommended that serious studies on poetry about women be undertaken. The analyses of selected poems by established isiXhosa poets show that modern poetry conventions are significantly used together with izibongo techniques. These techniques are used without any gender differentiation, which is another point of interest of this study. There are however instances where images specific to women are used. Such use has however not been found to be demeaning of women in any way. Poems where modern poetry forms and conventions are used tend to deal with subjects who have international or an urban area background. Even though the modern poetry conventions are used with izibongo techniques the presence of the modern literary conventions is prominent. This is the case particularly with poems about women in politics. That some female poet seems to accept some cultural practices that are viewed to be undermining the status of women does not take away the voice of protest against this oppression by some of the selected poets. These two voices, one of acceptance and the other one of protest are used as a basis for a debate around a need for a literary theory that addresses the question of African culture with special reference to isiXhosa poetry about women. The success of the selected poets with both modern and izibongo techniques is a good sign for the development of isiXhosa poetry in general and isiXhosa poetry about women. It is strongly recommended that continued research of a serious nature concerning poetry about, and produced by women, be undertaken.
- Full Text:
- Authors: Jadezweni, Mhlobo Wabantwana
- Date: 2013
- Subjects: Laudatory poetry, Xhosa African poetry (English) -- History and criticism Women in literature Women and literature -- South Africa African poetry -- Women authors
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3616 , http://hdl.handle.net/10962/d1006364
- Description: This study investigates the use of modern and izibongo (praise poetry) techniques in representing women in selected isiXhosa poems. The main interest of the study is to determine whether the same techniques to depict men are used when writing about women. It is also the interest of the study to ascertain how gender issues are dealt with in the selected poems. Seminal studies on izibongo by eminent scholars in this field show a serious lack of critique and little recognition of women in African languages’ poetry in general and in isiXhosa in particular. Pioneering studies in Nguni poetry about women have thus recommended that serious studies on poetry about women be undertaken. The analyses of selected poems by established isiXhosa poets show that modern poetry conventions are significantly used together with izibongo techniques. These techniques are used without any gender differentiation, which is another point of interest of this study. There are however instances where images specific to women are used. Such use has however not been found to be demeaning of women in any way. Poems where modern poetry forms and conventions are used tend to deal with subjects who have international or an urban area background. Even though the modern poetry conventions are used with izibongo techniques the presence of the modern literary conventions is prominent. This is the case particularly with poems about women in politics. That some female poet seems to accept some cultural practices that are viewed to be undermining the status of women does not take away the voice of protest against this oppression by some of the selected poets. These two voices, one of acceptance and the other one of protest are used as a basis for a debate around a need for a literary theory that addresses the question of African culture with special reference to isiXhosa poetry about women. The success of the selected poets with both modern and izibongo techniques is a good sign for the development of isiXhosa poetry in general and isiXhosa poetry about women. It is strongly recommended that continued research of a serious nature concerning poetry about, and produced by women, be undertaken.
- Full Text:
Assessing household assets to understand vulnerability to HIV/Aids and climate change in the Eastern Cape, South Africa
- Authors: Stadler, Leigh Tessa
- Date: 2013
- Subjects: Climatic changes -- South Africa -- Eastern Cape Climatic changes -- Health aspects -- South Africa -- Eastern Cape Climatic changes -- Economic aspects -- South Africa -- Eastern Cape HIV infections -- Economic aspects -- South Africa -- Eastern Cape AIDS (Disease) -- Economic aspects -- South Africa -- Eastern Cape HIV infections -- Social aspects -- South Africa -- Eastern Cape AIDS (Disease) -- Social aspects -- South Africa -- Eastern Cape Poverty -- Social aspects -- South Africa -- Eastern Cape Income -- South Africa -- Eastern Cape Human capital -- South Africa -- Eastern Cape Sex role -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4726 , http://hdl.handle.net/10962/d1001655
- Description: Livelihood stressors in southern Africa, such as HIV/Aids and climate change, do not act in isolation but rather interact concurrently in complex socio-ecological systems with diverse, interrelated and compounded affects. Households experience differential vulnerability to such stressors based on contextual factors such as geographical location, income level and the gender and age of its members. Households’ differential experiences of vulnerability are further defined by the households’ use of their capital stocks: the human, social, natural, financial and physical capital available to the household to form livelihoods and resist the detrimental effects of a stressor. The capital stocks of 340 households were measured in two sites in the Eastern Cape, South Africa, using a household survey. These data were analysed to determine differences between the sites, households with heads of different gender and households of different income levels. Further data relating to the drivers and interactions of stressors over temporal and spatial scales, as well as the perceived value of various forms of capital by different social groups in the two sites, were collected via Participatory Learning and Action (PLA) methods including timelines, mental modelling and pair-wise ranking. Although the two sites have similar levels of income and fall within the same province, many significant differences emerged. The two sites showed different distributions of household head genders and different stressors and perceptions of vulnerability, perhaps owing to differences in their capital stocks, acting alongside the influence of culture and access on a shifting rural-urban continuum. These discrepancies further transpired to reflect crucial differential experiences along gender lines and income levels in each site. Vulnerability was often context specific, not only because of unique drivers of stress in different areas, but also because socio-economic groups and localities often had characteristics that could potentially exacerbate vulnerability, as well as characteristics that can potentially facilitate adaptive capacity. Stressors were found to have depleted multiple forms of capital over time, while new stressors were emerging, raising concerns over the most appropriate means of social protection within these contexts.
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- Authors: Stadler, Leigh Tessa
- Date: 2013
- Subjects: Climatic changes -- South Africa -- Eastern Cape Climatic changes -- Health aspects -- South Africa -- Eastern Cape Climatic changes -- Economic aspects -- South Africa -- Eastern Cape HIV infections -- Economic aspects -- South Africa -- Eastern Cape AIDS (Disease) -- Economic aspects -- South Africa -- Eastern Cape HIV infections -- Social aspects -- South Africa -- Eastern Cape AIDS (Disease) -- Social aspects -- South Africa -- Eastern Cape Poverty -- Social aspects -- South Africa -- Eastern Cape Income -- South Africa -- Eastern Cape Human capital -- South Africa -- Eastern Cape Sex role -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4726 , http://hdl.handle.net/10962/d1001655
- Description: Livelihood stressors in southern Africa, such as HIV/Aids and climate change, do not act in isolation but rather interact concurrently in complex socio-ecological systems with diverse, interrelated and compounded affects. Households experience differential vulnerability to such stressors based on contextual factors such as geographical location, income level and the gender and age of its members. Households’ differential experiences of vulnerability are further defined by the households’ use of their capital stocks: the human, social, natural, financial and physical capital available to the household to form livelihoods and resist the detrimental effects of a stressor. The capital stocks of 340 households were measured in two sites in the Eastern Cape, South Africa, using a household survey. These data were analysed to determine differences between the sites, households with heads of different gender and households of different income levels. Further data relating to the drivers and interactions of stressors over temporal and spatial scales, as well as the perceived value of various forms of capital by different social groups in the two sites, were collected via Participatory Learning and Action (PLA) methods including timelines, mental modelling and pair-wise ranking. Although the two sites have similar levels of income and fall within the same province, many significant differences emerged. The two sites showed different distributions of household head genders and different stressors and perceptions of vulnerability, perhaps owing to differences in their capital stocks, acting alongside the influence of culture and access on a shifting rural-urban continuum. These discrepancies further transpired to reflect crucial differential experiences along gender lines and income levels in each site. Vulnerability was often context specific, not only because of unique drivers of stress in different areas, but also because socio-economic groups and localities often had characteristics that could potentially exacerbate vulnerability, as well as characteristics that can potentially facilitate adaptive capacity. Stressors were found to have depleted multiple forms of capital over time, while new stressors were emerging, raising concerns over the most appropriate means of social protection within these contexts.
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Assessment of potential anti-cancer stem cell activity of marine algal compounds using an in vitro mammosphere assay:
- de la Mare, Jo-Anne, Sterrenberg, Jason N, Sukhthankar, Mugdha G, Chiwakata, Maynard T, Beukes, Denzil R, Blatch, Gregory L, Edkins, Adrienne L
- Authors: de la Mare, Jo-Anne , Sterrenberg, Jason N , Sukhthankar, Mugdha G , Chiwakata, Maynard T , Beukes, Denzil R , Blatch, Gregory L , Edkins, Adrienne L
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165184 , vital:41216 , DOI: 10.1186/1475-2867-13-39
- Description: The cancer stem cell (CSC) theory proposes that tumours arise from and are sustained by a subpopulation of cells with both cancer and stem cell properties. One of the key hallmarks of CSCs is the ability to grow anchorage-independently under serum-free culture conditions resulting in the formation of tumourspheres. It has further been reported that these cells are resistant to traditional chemotherapeutic agents.
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- Authors: de la Mare, Jo-Anne , Sterrenberg, Jason N , Sukhthankar, Mugdha G , Chiwakata, Maynard T , Beukes, Denzil R , Blatch, Gregory L , Edkins, Adrienne L
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165184 , vital:41216 , DOI: 10.1186/1475-2867-13-39
- Description: The cancer stem cell (CSC) theory proposes that tumours arise from and are sustained by a subpopulation of cells with both cancer and stem cell properties. One of the key hallmarks of CSCs is the ability to grow anchorage-independently under serum-free culture conditions resulting in the formation of tumourspheres. It has further been reported that these cells are resistant to traditional chemotherapeutic agents.
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Audio Device Representation, Control, and Monitoring Using SNMP
- Eales, Andrew, Foss, Richard
- Authors: Eales, Andrew , Foss, Richard
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426855 , vital:72396 , https://www.aes.org/e-lib/browse.cfm?elib=17012
- Description: The Simple Network Management Protocol (SNMP) is widely used to configure and monitor networked devices. The architecture of complex audio devices can be elegantly represented using SNMP tables. Carefully considered table indexing schemes support a logical device model that can be accessed using standard SNMP commands. This paper examines the use of SNMP tables to represent the architecture of audio devices. A representational scheme that uses table indexes to provide direct-access to context-sensitive SNMP data objects is presented. The monitoring of parameter values and the implementation of connection management using SNMP are also discussed.
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- Authors: Eales, Andrew , Foss, Richard
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426855 , vital:72396 , https://www.aes.org/e-lib/browse.cfm?elib=17012
- Description: The Simple Network Management Protocol (SNMP) is widely used to configure and monitor networked devices. The architecture of complex audio devices can be elegantly represented using SNMP tables. Carefully considered table indexing schemes support a logical device model that can be accessed using standard SNMP commands. This paper examines the use of SNMP tables to represent the architecture of audio devices. A representational scheme that uses table indexes to provide direct-access to context-sensitive SNMP data objects is presented. The monitoring of parameter values and the implementation of connection management using SNMP are also discussed.
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Automated classification of computer network attacks
- van Heerden, Renier, Leenen, Louise, Irwin, Barry V W
- Authors: van Heerden, Renier , Leenen, Louise , Irwin, Barry V W
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429622 , vital:72627 , 10.1109/ICASTech.2013.6707510
- Description: In this paper we demonstrate how an automated reasoner, HermiT, is used to classify instances of computer network based attacks in conjunction with a network attack ontology. The ontology describes different types of network attacks through classes and inter-class relationships and has previously been implemented in the Protege ontology editor. Two significant recent instances of network based attacks are presented as individuals in the ontology and correctly classified by the automated reasoner according to the relevant types of attack scenarios depicted in the ontology. The two network attack instances are the Distributed Denial of Service attack on SpamHaus in 2013 and the theft of 42 million Rand ($6.7 million) from South African Postbank in 2012.
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- Authors: van Heerden, Renier , Leenen, Louise , Irwin, Barry V W
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429622 , vital:72627 , 10.1109/ICASTech.2013.6707510
- Description: In this paper we demonstrate how an automated reasoner, HermiT, is used to classify instances of computer network based attacks in conjunction with a network attack ontology. The ontology describes different types of network attacks through classes and inter-class relationships and has previously been implemented in the Protege ontology editor. Two significant recent instances of network based attacks are presented as individuals in the ontology and correctly classified by the automated reasoner according to the relevant types of attack scenarios depicted in the ontology. The two network attack instances are the Distributed Denial of Service attack on SpamHaus in 2013 and the theft of 42 million Rand ($6.7 million) from South African Postbank in 2012.
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Axial coordination of zinc and silicon phthalocyanines to silver and gold nanoparticles: an investigation of their photophysicochemical and antimicrobial behavior
- Masilela, Nkosiphile, Antunes, Edith M, Nyokong, Tebello
- Authors: Masilela, Nkosiphile , Antunes, Edith M , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241818 , vital:50972 , xlink:href="https://doi.org/10.1142/S1088424613500016"
- Description: This work reports on the axial coordination of zinc phthalocyanine and bis-(1,6-hexanedithiol) silicon phthalocyanine to silver and gold nanoparticles. Red shifting of absorption spectra of the phthalocyanine complexes was observed after conjugation with the nanoparticles. An improvement in the photophysicochemical behavior and antimicrobial activity was achieved in the presence of metal nanoparticles for both complexes. A decrease in triplet lifetimes was observed for all the phthalocyanine metal nanoparticle conjugates. The Zn phthalocyanine complex gave the highest triplet and singlet oxygen quantum yield in the presence of gold nanoparticles. On the other hand, the bacterial inhibition was found to be best for the Si phthalocyanine derivative in the presence of nanoparticles compared to the Zn phthalocyanine counterpart. The highest antimicrobial activity was achieved for both conjugates against B. subtilis compared to S. aureaus both in the dark and under illumination with light.
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- Authors: Masilela, Nkosiphile , Antunes, Edith M , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241818 , vital:50972 , xlink:href="https://doi.org/10.1142/S1088424613500016"
- Description: This work reports on the axial coordination of zinc phthalocyanine and bis-(1,6-hexanedithiol) silicon phthalocyanine to silver and gold nanoparticles. Red shifting of absorption spectra of the phthalocyanine complexes was observed after conjugation with the nanoparticles. An improvement in the photophysicochemical behavior and antimicrobial activity was achieved in the presence of metal nanoparticles for both complexes. A decrease in triplet lifetimes was observed for all the phthalocyanine metal nanoparticle conjugates. The Zn phthalocyanine complex gave the highest triplet and singlet oxygen quantum yield in the presence of gold nanoparticles. On the other hand, the bacterial inhibition was found to be best for the Si phthalocyanine derivative in the presence of nanoparticles compared to the Zn phthalocyanine counterpart. The highest antimicrobial activity was achieved for both conjugates against B. subtilis compared to S. aureaus both in the dark and under illumination with light.
- Full Text: