Over-expression, purification and biochemical characterization of DOXP reductoisomerase and the rational design of novel anti-malarial drugs
- Authors: Tanner, Delia Caroline
- Date: 2004
- Subjects: Malaria -- Prevention , Malaria -- Drug therapy , Antimalarials -- Therapeutic use , Proteins -- Purification , Amino acids -- Analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3931 , http://hdl.handle.net/10962/d1003990 , Malaria -- Prevention , Malaria -- Drug therapy , Antimalarials -- Therapeutic use , Proteins -- Purification , Amino acids -- Analysis
- Description: Malaria poses the greatest threat of all parasites to human life. Current vaccines and efficacious drugs are available however their use is limited due to toxicity, emergence of drug resistance, and cost. The discovery of an alternative pathway of isoprenoid biosynthesis, the non-mevalonate pathway, within the malarial parasite has resulted in development of novel anti-malarial drugs. 1-Deoxy-D-xylulose-5-phosphate (DOXP) reductoisomerase, the second enzyme in this pathway, is responsible for the synthesis of 2-C-methyl-D-erythritol 4-phosphate (MEP) in an intramolecular rearrangement step followed by a reduction process involving NADPH as a hydrogen donor and divalent cations as co-factors. Fosmidomycin and FR900098 have been identified as inhibitors of DOXP reductoisomerase. However, they lack clinical efficacy. In this investigation recombinant DOXP reductoisomerase from Escherichia coli (EcDXR) and Plasmodium falciparum (pfDXR) were biochemically characterized as potential targets for inhibition. (His)6-EcDXR was successfully purified using nickel-chelate affinity chromatography with a specific activity of 1.77 μmoles/min/mg and Km value 282 μM. Utilizing multiple sequence alignment, previous structural data predictions and homology modeling approaches, critical active site amino acid residues were identified and their role in the catalytic activity investigated utilizing site-directed mutagenesis techniques. We have shown evidence that suggests that Trp212 and Met214 interact to maintain the active site architecture and hydrophobic interactions necessary for substrate binding, cofactor binding and enzyme activity. Replacement of Trp212 with Tyr, Phe, and Leu reduced specific activity relative to EcDXR. EcDXR(W212F) and EcDXR(W212Y) had an increased Km relative to EcDXR indicative of loss in affinity toward DOXP, whereas EcDXR(W212L) had a lower Km of ~8 μM indicative of increased affinity for DOXP. The W212L substitution possibly removed contacts necessary for full catalytic activity, but could be considered a non-disruptive substitution in that it maintained active site architecture sufficient for DOXP reductoisomerase activity. EcDXR(M214I) had 36-fold reduced enzyme activity relative to EcDXR, while its Km (~8 μM) was found to be lower than that of EcDXR. This suggested that the M214I substitution had maintained (perhaps improved) substrate and active site architecture, but may have perturbed interactions with NADPH. Rational drug design strategies and docking methods have been utilized in the development of furan derivatives as DOXP reductoisomerase inhibitors, and the synthesis of phosphorylated derivatives (5) and (6) has been achieved. Future inhibitor studies using these novel potential DOXP reductoisomerase inhibitors may lead to the development of effective anti-malarial drug candidates.
- Full Text:
- Date Issued: 2004
- Authors: Tanner, Delia Caroline
- Date: 2004
- Subjects: Malaria -- Prevention , Malaria -- Drug therapy , Antimalarials -- Therapeutic use , Proteins -- Purification , Amino acids -- Analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3931 , http://hdl.handle.net/10962/d1003990 , Malaria -- Prevention , Malaria -- Drug therapy , Antimalarials -- Therapeutic use , Proteins -- Purification , Amino acids -- Analysis
- Description: Malaria poses the greatest threat of all parasites to human life. Current vaccines and efficacious drugs are available however their use is limited due to toxicity, emergence of drug resistance, and cost. The discovery of an alternative pathway of isoprenoid biosynthesis, the non-mevalonate pathway, within the malarial parasite has resulted in development of novel anti-malarial drugs. 1-Deoxy-D-xylulose-5-phosphate (DOXP) reductoisomerase, the second enzyme in this pathway, is responsible for the synthesis of 2-C-methyl-D-erythritol 4-phosphate (MEP) in an intramolecular rearrangement step followed by a reduction process involving NADPH as a hydrogen donor and divalent cations as co-factors. Fosmidomycin and FR900098 have been identified as inhibitors of DOXP reductoisomerase. However, they lack clinical efficacy. In this investigation recombinant DOXP reductoisomerase from Escherichia coli (EcDXR) and Plasmodium falciparum (pfDXR) were biochemically characterized as potential targets for inhibition. (His)6-EcDXR was successfully purified using nickel-chelate affinity chromatography with a specific activity of 1.77 μmoles/min/mg and Km value 282 μM. Utilizing multiple sequence alignment, previous structural data predictions and homology modeling approaches, critical active site amino acid residues were identified and their role in the catalytic activity investigated utilizing site-directed mutagenesis techniques. We have shown evidence that suggests that Trp212 and Met214 interact to maintain the active site architecture and hydrophobic interactions necessary for substrate binding, cofactor binding and enzyme activity. Replacement of Trp212 with Tyr, Phe, and Leu reduced specific activity relative to EcDXR. EcDXR(W212F) and EcDXR(W212Y) had an increased Km relative to EcDXR indicative of loss in affinity toward DOXP, whereas EcDXR(W212L) had a lower Km of ~8 μM indicative of increased affinity for DOXP. The W212L substitution possibly removed contacts necessary for full catalytic activity, but could be considered a non-disruptive substitution in that it maintained active site architecture sufficient for DOXP reductoisomerase activity. EcDXR(M214I) had 36-fold reduced enzyme activity relative to EcDXR, while its Km (~8 μM) was found to be lower than that of EcDXR. This suggested that the M214I substitution had maintained (perhaps improved) substrate and active site architecture, but may have perturbed interactions with NADPH. Rational drug design strategies and docking methods have been utilized in the development of furan derivatives as DOXP reductoisomerase inhibitors, and the synthesis of phosphorylated derivatives (5) and (6) has been achieved. Future inhibitor studies using these novel potential DOXP reductoisomerase inhibitors may lead to the development of effective anti-malarial drug candidates.
- Full Text:
- Date Issued: 2004
Praxis-based assignments for professional development in the Rhodes University/Swaziland Participatory Course in Environmental Education : the case of assignment four
- Authors: Motsa, Elizabeth Matfobhi
- Date: 2004
- Subjects: Rhodes University / Swaziland Participatory Course in Environmental Education Environmental education -- Swaziland Environmental education -- Study and teaching -- Swaziland
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1710 , http://hdl.handle.net/10962/d1003593
- Description: The aim of this study was to find out how praxis is fostered in professional development processes, through the assignment four of the Rhodes University / Swaziland Participatory course in Environmental Education (referred to as the Swaziland course), in the Swaziland context. The research aimed at exploring instances of praxis in assignment four development processes and in implementing the assignment ‘product’ in the field of participants’ practice at their schools. The research is intended to improve practice in professional development in the Swaziland course, and in the SADC region more broadly, although the case study does not assume generalisability. The study employed a naturalistic research methodology, involving the development of an interpretive case study to aid understanding of social phenomena in the natural setting. It is influenced by the belief that knowledge is socially constructed and the assumption that meanings are generated and shared through language. The research methods involved observing interactions in the course processes during tutorials sessions and I compiled a course processes profile. I also analyzed copies of assignment four products of two course participants, and observed them using their assignment ‘products’ in their workplaces. Using this data, I generated two ‘constructions’ of the two course participants’ experiences of praxis-based assignment work in the Swaziland course. I also interviewed two course tutors. Data was analysed with an intention to understand actions and interactions relating to praxis-based assignment work. Two ‘layers’ of data analysis were undertaken, to deepen understanding of the phenomenon studied. Through this research I have learnt that though assignment processes enable praxis basedlearning, there are problems encountered in participants’ field of practice due to power relations and participants articulation of the relationship between theory and practice. These, and other structural factors impinge on reflexive agency in the context of both educational and environmental praxis. The structures in the school system frustrate reflexive agency in environmental teaching and learning, and socio-political and socio-economic structures also constrain environmental praxis, hence false consciousness prevails. Given the above situation I recommend further research into the relationship between environmental and educational praxis in environmental education and further research into reflexive agency in environmental education contexts.
- Full Text:
- Date Issued: 2004
- Authors: Motsa, Elizabeth Matfobhi
- Date: 2004
- Subjects: Rhodes University / Swaziland Participatory Course in Environmental Education Environmental education -- Swaziland Environmental education -- Study and teaching -- Swaziland
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1710 , http://hdl.handle.net/10962/d1003593
- Description: The aim of this study was to find out how praxis is fostered in professional development processes, through the assignment four of the Rhodes University / Swaziland Participatory course in Environmental Education (referred to as the Swaziland course), in the Swaziland context. The research aimed at exploring instances of praxis in assignment four development processes and in implementing the assignment ‘product’ in the field of participants’ practice at their schools. The research is intended to improve practice in professional development in the Swaziland course, and in the SADC region more broadly, although the case study does not assume generalisability. The study employed a naturalistic research methodology, involving the development of an interpretive case study to aid understanding of social phenomena in the natural setting. It is influenced by the belief that knowledge is socially constructed and the assumption that meanings are generated and shared through language. The research methods involved observing interactions in the course processes during tutorials sessions and I compiled a course processes profile. I also analyzed copies of assignment four products of two course participants, and observed them using their assignment ‘products’ in their workplaces. Using this data, I generated two ‘constructions’ of the two course participants’ experiences of praxis-based assignment work in the Swaziland course. I also interviewed two course tutors. Data was analysed with an intention to understand actions and interactions relating to praxis-based assignment work. Two ‘layers’ of data analysis were undertaken, to deepen understanding of the phenomenon studied. Through this research I have learnt that though assignment processes enable praxis basedlearning, there are problems encountered in participants’ field of practice due to power relations and participants articulation of the relationship between theory and practice. These, and other structural factors impinge on reflexive agency in the context of both educational and environmental praxis. The structures in the school system frustrate reflexive agency in environmental teaching and learning, and socio-political and socio-economic structures also constrain environmental praxis, hence false consciousness prevails. Given the above situation I recommend further research into the relationship between environmental and educational praxis in environmental education and further research into reflexive agency in environmental education contexts.
- Full Text:
- Date Issued: 2004
Price discovery, price behaviour, and efficiency of selected grain commodities traded on the agricultural products division of the JSE securities exchange
- Authors: Viljoen, Christo
- Date: 2004
- Subjects: Johannesburg Stock Exchange Stock exchanges -- South Africa International economic relations Primary commodities -- South Africa Grain trade -- South Africa Financial futures -- South Africa Price regulation -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:952 , http://hdl.handle.net/10962/d1002686
- Description: Agricultural commodity derivatives were first introduced in South Africa in 1996 after the deregulation of the former marketing system. In the context of its proposed functions, namely price discovery and risk management, the question arose as to whether the futures market developed over time to performed its role efficiently. According to the Efficient Markets Hypothesis (EMH) an efficient market is one that accurately incorporates all information available at any point in time. The purpose of the research was to address the issue of price discovery efficiency, firstly, focusing on the weak-form methodology. Secondly, considering the behaviour of futures prices over time, the study addressed the concern of anomalies in daily returns – phenomena contradictory to the EMH by implication. Thirdly, as a means of defining the sources of inefficiency, the role of scheduled public information and its impact on futures prices was examined. Therefore, the primary objective of the research was to investigate and identify the main components of agricultural futures market inefficiency within the unique price formation structure of South African grain markets. The assessment of this problem is important in terms of evaluating the growth and development of the futures market for different grain commodities to date. The Exchange needs to review rules and regulations on a frequent basis in order to ensure proper functioning at all times especially in the case of a relatively new and fast growing market. The study contributed to the knowledge of understanding the price adjustment process and its implications for market efficiency in the context of the three grain markets considered. The weak-form efficiency was tested using a co-integration based model. Analysing daily spot and futures prices of white maize, yellow maize, and wheat, results indicated that all three markets were efficient and unbiased. Non-parametric tests revealed the significant presence of day-of-the-week and turn-of-the-month effects in the futures returns of the three commodities. Further non-parametric analyses suggested a high degree of uncertainty in futures returns around scheduled agricultural and macroeconomic information release dates also contributing significantly to the identified anomalies. It was concluded that (1) the markets’ ability to anticipate the contents of future information to be released, (2) the current skewed size distribution of broking members, (3) the significant role of the R/$ exchange rate in the price formation process of South African grains and, therefore, (4) the relationship to and influence of the broader economy enhanced the return effects (anomalies) creating opportunity for profitable arbitrage. This conclusion was mainly attributed to South Africa’s status as a price-taker in the world grain complex as well as the relatively short existence of the local agricultural futures markets.
- Full Text:
- Date Issued: 2004
- Authors: Viljoen, Christo
- Date: 2004
- Subjects: Johannesburg Stock Exchange Stock exchanges -- South Africa International economic relations Primary commodities -- South Africa Grain trade -- South Africa Financial futures -- South Africa Price regulation -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:952 , http://hdl.handle.net/10962/d1002686
- Description: Agricultural commodity derivatives were first introduced in South Africa in 1996 after the deregulation of the former marketing system. In the context of its proposed functions, namely price discovery and risk management, the question arose as to whether the futures market developed over time to performed its role efficiently. According to the Efficient Markets Hypothesis (EMH) an efficient market is one that accurately incorporates all information available at any point in time. The purpose of the research was to address the issue of price discovery efficiency, firstly, focusing on the weak-form methodology. Secondly, considering the behaviour of futures prices over time, the study addressed the concern of anomalies in daily returns – phenomena contradictory to the EMH by implication. Thirdly, as a means of defining the sources of inefficiency, the role of scheduled public information and its impact on futures prices was examined. Therefore, the primary objective of the research was to investigate and identify the main components of agricultural futures market inefficiency within the unique price formation structure of South African grain markets. The assessment of this problem is important in terms of evaluating the growth and development of the futures market for different grain commodities to date. The Exchange needs to review rules and regulations on a frequent basis in order to ensure proper functioning at all times especially in the case of a relatively new and fast growing market. The study contributed to the knowledge of understanding the price adjustment process and its implications for market efficiency in the context of the three grain markets considered. The weak-form efficiency was tested using a co-integration based model. Analysing daily spot and futures prices of white maize, yellow maize, and wheat, results indicated that all three markets were efficient and unbiased. Non-parametric tests revealed the significant presence of day-of-the-week and turn-of-the-month effects in the futures returns of the three commodities. Further non-parametric analyses suggested a high degree of uncertainty in futures returns around scheduled agricultural and macroeconomic information release dates also contributing significantly to the identified anomalies. It was concluded that (1) the markets’ ability to anticipate the contents of future information to be released, (2) the current skewed size distribution of broking members, (3) the significant role of the R/$ exchange rate in the price formation process of South African grains and, therefore, (4) the relationship to and influence of the broader economy enhanced the return effects (anomalies) creating opportunity for profitable arbitrage. This conclusion was mainly attributed to South Africa’s status as a price-taker in the world grain complex as well as the relatively short existence of the local agricultural futures markets.
- Full Text:
- Date Issued: 2004
Probing learners' conceptual understanding of oxidation and reduction (redox) reactions : a case study
- Authors: Addam, Billey Bright
- Date: 2004
- Subjects: Competency based education -- South Africa Oxidation-reduction reaction -- Study and teaching Science -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1409 , http://hdl.handle.net/10962/d1002950
- Description: The new political dispensation in South Africa has seen a lot of changes taking place. The democratic wind, which has been blowing in all spheres of the political arena, could not leave out Education. This has led to the transformation in education and the revision of the curriculum guided by the Outcomes-Based Education philosophy (OBE). Thus, require education authorities as well as educators to look at education more comprehensively. The challenge posed to educators now is to develop tools and strategies that will make learning accessible to as many learners as possible and to teach for understanding and construction of knowledge. The principal objective of this study was to investigate the important role the learner's prior knowledge plays and the use of different tools and strategies in stimulating conceptual understanding and construction of knowledge of redox reactions. This was done using learners' own investigations, practical activities, teaching settings and a workshop. The findings show that the learners lacked organized and structured prior knowledge. Learners could not integrate prior experience with new experience. The main issue seems to be the failure of learners to relate classroom experience to everyday redox phenomena. Possible reasons are discussed with some implications for teaching redox. The study further postulates that to assist learners to develop conceptual understanding of redox reactions, different tools and strategies should be employed and teaching made relevant to real-life situations. In so doing, redox concepts would not be abstract to learners.
- Full Text:
- Date Issued: 2004
- Authors: Addam, Billey Bright
- Date: 2004
- Subjects: Competency based education -- South Africa Oxidation-reduction reaction -- Study and teaching Science -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1409 , http://hdl.handle.net/10962/d1002950
- Description: The new political dispensation in South Africa has seen a lot of changes taking place. The democratic wind, which has been blowing in all spheres of the political arena, could not leave out Education. This has led to the transformation in education and the revision of the curriculum guided by the Outcomes-Based Education philosophy (OBE). Thus, require education authorities as well as educators to look at education more comprehensively. The challenge posed to educators now is to develop tools and strategies that will make learning accessible to as many learners as possible and to teach for understanding and construction of knowledge. The principal objective of this study was to investigate the important role the learner's prior knowledge plays and the use of different tools and strategies in stimulating conceptual understanding and construction of knowledge of redox reactions. This was done using learners' own investigations, practical activities, teaching settings and a workshop. The findings show that the learners lacked organized and structured prior knowledge. Learners could not integrate prior experience with new experience. The main issue seems to be the failure of learners to relate classroom experience to everyday redox phenomena. Possible reasons are discussed with some implications for teaching redox. The study further postulates that to assist learners to develop conceptual understanding of redox reactions, different tools and strategies should be employed and teaching made relevant to real-life situations. In so doing, redox concepts would not be abstract to learners.
- Full Text:
- Date Issued: 2004
Processes that influence the experiences of children living with mothers that have HIV: two case studies
- Authors: Castelletto, Simona
- Date: 2004
- Subjects: AIDS (Disease) in women , AIDS (Disease) -- Social aspects -- South Africa , HIV infections -- Social aspects -- South Africa , Mothers and daughters -- Social aspects , Mothers and sons -- Social aspects , AIDS (Disease) in children -- Social aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3166 , http://hdl.handle.net/10962/d1007728 , AIDS (Disease) in women , AIDS (Disease) -- Social aspects -- South Africa , HIV infections -- Social aspects -- South Africa , Mothers and daughters -- Social aspects , Mothers and sons -- Social aspects , AIDS (Disease) in children -- Social aspects -- South Africa
- Description: Maternal HIV-infection is considered to be a threat to the psychosocial development of AIDS-affected children. In South Africa, AIDS-affected children may be particularly vulnerable due to the unprecedented effects of the HIV/AIDS epidemic on the breakdown of family and community resources in already disadvantaged communities. The aim of this study was to explore the contextualised experiences of two children living with mothers who have HIV by conducting two case studies. Mother-child dyads were recruited from local HIV/AIDS centres and informed consent was obtained. The mothers were in the minor symptomatic phase of HIV-infection and the children were uninfected and aged between 10 and 12 years. Through semi-structured interviewing, the mothers provided background and contextual information about the children. Play techniques were used in the child interviews to encourage the introduction and exploration of issues salient to the children. Play facilitated engagement around sensitive and potentially anxiety-provoking material. A key issue for the children was their concerns about the anticipated deaths of their mothers. The children held misconceptions about the transmission of HIV/ AIDS. They feared HIV/AIDS and expected that others would have negative perceptions of them. Family processes such as secrecy and avoidance around HIV/AIDS-related issues were understood to perpetuate the children's fears and false beliefs in a broader community context that stigmatised HIV/AIDS. It was argued that the mothers' shame over HIV-infection and their need to protect their relationship with their children compromised their ability to communicate openly with their children and to offer them meaningful emotional support. Limited parental involvement was identified as the key contextual process that engendered vulnerability in the children, as they were isolated within and beyond the family. Recommendations to address the processes that engendered vulnerability in the children are discussed.
- Full Text:
- Date Issued: 2004
- Authors: Castelletto, Simona
- Date: 2004
- Subjects: AIDS (Disease) in women , AIDS (Disease) -- Social aspects -- South Africa , HIV infections -- Social aspects -- South Africa , Mothers and daughters -- Social aspects , Mothers and sons -- Social aspects , AIDS (Disease) in children -- Social aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3166 , http://hdl.handle.net/10962/d1007728 , AIDS (Disease) in women , AIDS (Disease) -- Social aspects -- South Africa , HIV infections -- Social aspects -- South Africa , Mothers and daughters -- Social aspects , Mothers and sons -- Social aspects , AIDS (Disease) in children -- Social aspects -- South Africa
- Description: Maternal HIV-infection is considered to be a threat to the psychosocial development of AIDS-affected children. In South Africa, AIDS-affected children may be particularly vulnerable due to the unprecedented effects of the HIV/AIDS epidemic on the breakdown of family and community resources in already disadvantaged communities. The aim of this study was to explore the contextualised experiences of two children living with mothers who have HIV by conducting two case studies. Mother-child dyads were recruited from local HIV/AIDS centres and informed consent was obtained. The mothers were in the minor symptomatic phase of HIV-infection and the children were uninfected and aged between 10 and 12 years. Through semi-structured interviewing, the mothers provided background and contextual information about the children. Play techniques were used in the child interviews to encourage the introduction and exploration of issues salient to the children. Play facilitated engagement around sensitive and potentially anxiety-provoking material. A key issue for the children was their concerns about the anticipated deaths of their mothers. The children held misconceptions about the transmission of HIV/ AIDS. They feared HIV/AIDS and expected that others would have negative perceptions of them. Family processes such as secrecy and avoidance around HIV/AIDS-related issues were understood to perpetuate the children's fears and false beliefs in a broader community context that stigmatised HIV/AIDS. It was argued that the mothers' shame over HIV-infection and their need to protect their relationship with their children compromised their ability to communicate openly with their children and to offer them meaningful emotional support. Limited parental involvement was identified as the key contextual process that engendered vulnerability in the children, as they were isolated within and beyond the family. Recommendations to address the processes that engendered vulnerability in the children are discussed.
- Full Text:
- Date Issued: 2004
Promoting learners' conceptual understanding of electrostatics through use of practical activities in conjunction with prior knowledge of lightning : a case study
- Authors: Maselwa, Matole Reuben
- Date: 2004
- Subjects: Electrostatics -- Study and teaching -- Case studies Science -- Study and teaching -- Case studies Lightning -- Study and teaching -- Case studies
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1717 , http://hdl.handle.net/10962/d1003600
- Description: The research presented in this thesis is situated within an interpretivist paradigm. Within this paradigm, a qualitative case-study research approach was adopted. This seemed most appropriate in my research project since the main focus is on elicitation of prior knowledge and incorporation of such knowledge into 'hands-on' and 'minds-on' practical activities with a view to improving conceptual development. For the purposes of this research project, I designed an interactive teaching and learning unit in electrostatics as an attempt to put into practice a learner-centred approach. This approach, in my view, is in line with the new curriculum in South Africa. The emerging central theme of this thesis is the notion of active participation by learners during teaching and learning. This study was carried out over a period of two years and involved my grade 9 learners, who participated voluntarily. The research process documented in this thesis has been conceptualised into two phases. Phase one was concerned with the elicitation of learners' prior knowledge around lightning. In phase two, learners were engaged in 'hands-on' and 'minds-on' practical activities, and key concepts were identified to ensure conceptual development. The data was collected using a variety of data collection tools, namely: focus group interviews, follow-up whole-class semi-structured interviews, worksheets, videotaped lessons and photographs. The analysis of data revealed that learners come to class with prior knowledge concerning lightning. Within this prior knowledge it was found that there were both ‘scientific’ and ‘non-scientific’ concepts. The identification of key concepts during practical activities was found to be very useful in promoting learning. However, the incorporation of prior knowledge into practical activities posed a challenge and needs further research. iv This research study also highlights some insights into some of the complexities of elicitation and incorporation of learners' prior knowledge, and conceptual development in science classrooms. It also demonstrates the challenges and possibilities during teaching and learning as well as the realities of the demands of the new curriculum and OBE in South Africa, in particular, in historically disadvantaged schools
- Full Text:
- Date Issued: 2004
- Authors: Maselwa, Matole Reuben
- Date: 2004
- Subjects: Electrostatics -- Study and teaching -- Case studies Science -- Study and teaching -- Case studies Lightning -- Study and teaching -- Case studies
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1717 , http://hdl.handle.net/10962/d1003600
- Description: The research presented in this thesis is situated within an interpretivist paradigm. Within this paradigm, a qualitative case-study research approach was adopted. This seemed most appropriate in my research project since the main focus is on elicitation of prior knowledge and incorporation of such knowledge into 'hands-on' and 'minds-on' practical activities with a view to improving conceptual development. For the purposes of this research project, I designed an interactive teaching and learning unit in electrostatics as an attempt to put into practice a learner-centred approach. This approach, in my view, is in line with the new curriculum in South Africa. The emerging central theme of this thesis is the notion of active participation by learners during teaching and learning. This study was carried out over a period of two years and involved my grade 9 learners, who participated voluntarily. The research process documented in this thesis has been conceptualised into two phases. Phase one was concerned with the elicitation of learners' prior knowledge around lightning. In phase two, learners were engaged in 'hands-on' and 'minds-on' practical activities, and key concepts were identified to ensure conceptual development. The data was collected using a variety of data collection tools, namely: focus group interviews, follow-up whole-class semi-structured interviews, worksheets, videotaped lessons and photographs. The analysis of data revealed that learners come to class with prior knowledge concerning lightning. Within this prior knowledge it was found that there were both ‘scientific’ and ‘non-scientific’ concepts. The identification of key concepts during practical activities was found to be very useful in promoting learning. However, the incorporation of prior knowledge into practical activities posed a challenge and needs further research. iv This research study also highlights some insights into some of the complexities of elicitation and incorporation of learners' prior knowledge, and conceptual development in science classrooms. It also demonstrates the challenges and possibilities during teaching and learning as well as the realities of the demands of the new curriculum and OBE in South Africa, in particular, in historically disadvantaged schools
- Full Text:
- Date Issued: 2004
Protecting depositors and promoting financial stability in South Africa : is there a case for the introduction of deposit insurance?
- Authors: Ngaujake, Uahatjiri
- Date: 2004
- Subjects: Banks and banking -- South Africa , Bank deposits -- South Africa , Bank failures , Banks and banking -- State supervision , Deposit insurance , Consumer protection -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1025 , http://hdl.handle.net/10962/d1002760 , Banks and banking -- South Africa , Bank deposits -- South Africa , Bank failures , Banks and banking -- State supervision , Deposit insurance , Consumer protection -- South Africa
- Description: Banks play a pivotal role in economic growth and development of all countries and therefore the stability of the banking system is a vital goal of bank supervisors. Banks act as delegated monitors of depositors’ funds and this relationship, like all principal-agent relationships, presents agency problems. In the case of banks agency problems arise because depositors cannot accurately assess the financial health of banks due to the asymmetry of information existing between banks and depositors. Because banks possess private information on their borrowers, which depositors cannot access, it exposes depositors to risk of loss of deposits in cases of bank failures originating from nonrepayment of such loans. This asymmetry of information also exposes banks to runs by depositors and these runs can lead to bank failures with devastating effects for the financial system and the economy at large. It is for this reason that banks are regulated and supervised more than other institutions. Bank failures are a worldwide phenomenon and South Africa is no exception as evidenced by historical and recent bank failures in South Africa. This thesis investigates the desirability of introducing an explicit deposit insurance scheme in South Africa as a means of protecting small, unsophisticated depositors who are almost always the losers when banks fail, and promoting financial stability. The study finds that bank failures in South Africa are mainly attributable to mismanagement of banks, liquidity problems and fraud. Bank failures as a result of the aforementioned reasons have led to depositors losing their deposits in South Africa. The absence of a clearly defined depositor protection scheme in South Africa, the inadequacy of the hitherto implicit guarantee system to protect depositors, and the poor record of the South African Reserve Bank in bank failure resolution, form the basis of the conclusion of the study, i.e., there is a case for the introduction of deposit insurance in South Africa. In order to assist South African policymakers in designing an effective deposit insurance scheme for the country, the thesis further provides a guide on how the most important design features of deposit insurance should be handled. This is in an attempt to ensure that the moral hazard problem inherent in deposit insurance is overcome.
- Full Text:
- Date Issued: 2004
- Authors: Ngaujake, Uahatjiri
- Date: 2004
- Subjects: Banks and banking -- South Africa , Bank deposits -- South Africa , Bank failures , Banks and banking -- State supervision , Deposit insurance , Consumer protection -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1025 , http://hdl.handle.net/10962/d1002760 , Banks and banking -- South Africa , Bank deposits -- South Africa , Bank failures , Banks and banking -- State supervision , Deposit insurance , Consumer protection -- South Africa
- Description: Banks play a pivotal role in economic growth and development of all countries and therefore the stability of the banking system is a vital goal of bank supervisors. Banks act as delegated monitors of depositors’ funds and this relationship, like all principal-agent relationships, presents agency problems. In the case of banks agency problems arise because depositors cannot accurately assess the financial health of banks due to the asymmetry of information existing between banks and depositors. Because banks possess private information on their borrowers, which depositors cannot access, it exposes depositors to risk of loss of deposits in cases of bank failures originating from nonrepayment of such loans. This asymmetry of information also exposes banks to runs by depositors and these runs can lead to bank failures with devastating effects for the financial system and the economy at large. It is for this reason that banks are regulated and supervised more than other institutions. Bank failures are a worldwide phenomenon and South Africa is no exception as evidenced by historical and recent bank failures in South Africa. This thesis investigates the desirability of introducing an explicit deposit insurance scheme in South Africa as a means of protecting small, unsophisticated depositors who are almost always the losers when banks fail, and promoting financial stability. The study finds that bank failures in South Africa are mainly attributable to mismanagement of banks, liquidity problems and fraud. Bank failures as a result of the aforementioned reasons have led to depositors losing their deposits in South Africa. The absence of a clearly defined depositor protection scheme in South Africa, the inadequacy of the hitherto implicit guarantee system to protect depositors, and the poor record of the South African Reserve Bank in bank failure resolution, form the basis of the conclusion of the study, i.e., there is a case for the introduction of deposit insurance in South Africa. In order to assist South African policymakers in designing an effective deposit insurance scheme for the country, the thesis further provides a guide on how the most important design features of deposit insurance should be handled. This is in an attempt to ensure that the moral hazard problem inherent in deposit insurance is overcome.
- Full Text:
- Date Issued: 2004
Purification and characterisation of 20S proteasome from ostrich skeletal muscle and its role in meat tenderisation
- Authors: Thomas, Adele René
- Date: 2004
- Subjects: Proteolytic enzymes , Ostrich products industry
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:11081 , http://hdl.handle.net/10948/320 , Proteolytic enzymes , Ostrich products industry
- Description: The proteasome is renowned for its high molecular weight, multisubunit and mulicatalytic nature. One of its many suggested roles is the degradation of myofibrillar proteins, and therefore it has been proposed to play a role in the meat tenderisation process. The aim of this study was therefore to isolate, purify and characterise the 20S proteasome from ostrich skeletal muscle, with a view to ultimately investigating its role in the tenderisation process of ostrich meat. The 20S proteasome was successfully isolated and purified from ostrich skeletal muscle using Toyopearl Super Q-650S, Sephacryl S-300, hydroxylapatite and Mono Q chromatographies. The intact molecule showed a molecular weight of 725 K and a pI of 6.67. The subunits showed a molecular weight range of 22.2-33.5 K and a pI range of 3-9. 2D-PAGE revealed at least 14 polypeptides. The amino acid composition of the intact enzyme and of each of the eight subunits separating on SDSPAGE, as well as the N-terminal sequences of five of the eight subunits, were determined. The trypsinlike (Tr-L), chymotrypsin-like (ChT-L), peptidylglutamyl peptide hydrolase (PGPH) and caseinolytic activities showed pH optima of 11, 9, 7-8 and 10.3, and temperature optima of 40, 60, 70 and 60oC, respectively. The pH stability range for all four activities was 5-12. The ChT-L and PGPH activities showed thermostabilities up to 60oC, whereas the Tr-L and caseinolytic activities were stable up to 40o C. The enzyme showed complex kinetics. It was inhibited by the peptide aldehyde Z-LLL-CHO and cysteine protease inhibitors. Cations had negligible effects on the enzyme, excepting for Ca2+ and Mg2+. Of the detergents tested, SDS had the most potent stimulatory effect, particularly on the PGPH and caseinolytic activities. The fatty acid studies showed that unsaturation enhanced the ChT-L and the caseinolytic activities, while it completely suppressed the Tr-L activity. Heating at 60oC for 1-2 min stimulated the caseinolytic and PGPH activities. The studies on the role of ostrich skeletal muscle 20S proteasome in ostrich meat tenderisation suggested a definite but minor role of this enzyme, based on the fact that it remained active throughout the 12 days of storage of ostrich M. iliofibularis meat at 4oC and that it participated in myofibril degradation of post-mortem muscle, but to a small degree. These results support the proposal that the proteasome comes into play after the calpains have initiated degradation. However, there was a lack of improvement in tenderness values and minimal myofibrillar degradation over the 12-day storage period of the ostrich M. iliofibularis meat, leading to the conclusion that the tenderisation of this meat was incomplete after 12 days.
- Full Text:
- Date Issued: 2004
- Authors: Thomas, Adele René
- Date: 2004
- Subjects: Proteolytic enzymes , Ostrich products industry
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:11081 , http://hdl.handle.net/10948/320 , Proteolytic enzymes , Ostrich products industry
- Description: The proteasome is renowned for its high molecular weight, multisubunit and mulicatalytic nature. One of its many suggested roles is the degradation of myofibrillar proteins, and therefore it has been proposed to play a role in the meat tenderisation process. The aim of this study was therefore to isolate, purify and characterise the 20S proteasome from ostrich skeletal muscle, with a view to ultimately investigating its role in the tenderisation process of ostrich meat. The 20S proteasome was successfully isolated and purified from ostrich skeletal muscle using Toyopearl Super Q-650S, Sephacryl S-300, hydroxylapatite and Mono Q chromatographies. The intact molecule showed a molecular weight of 725 K and a pI of 6.67. The subunits showed a molecular weight range of 22.2-33.5 K and a pI range of 3-9. 2D-PAGE revealed at least 14 polypeptides. The amino acid composition of the intact enzyme and of each of the eight subunits separating on SDSPAGE, as well as the N-terminal sequences of five of the eight subunits, were determined. The trypsinlike (Tr-L), chymotrypsin-like (ChT-L), peptidylglutamyl peptide hydrolase (PGPH) and caseinolytic activities showed pH optima of 11, 9, 7-8 and 10.3, and temperature optima of 40, 60, 70 and 60oC, respectively. The pH stability range for all four activities was 5-12. The ChT-L and PGPH activities showed thermostabilities up to 60oC, whereas the Tr-L and caseinolytic activities were stable up to 40o C. The enzyme showed complex kinetics. It was inhibited by the peptide aldehyde Z-LLL-CHO and cysteine protease inhibitors. Cations had negligible effects on the enzyme, excepting for Ca2+ and Mg2+. Of the detergents tested, SDS had the most potent stimulatory effect, particularly on the PGPH and caseinolytic activities. The fatty acid studies showed that unsaturation enhanced the ChT-L and the caseinolytic activities, while it completely suppressed the Tr-L activity. Heating at 60oC for 1-2 min stimulated the caseinolytic and PGPH activities. The studies on the role of ostrich skeletal muscle 20S proteasome in ostrich meat tenderisation suggested a definite but minor role of this enzyme, based on the fact that it remained active throughout the 12 days of storage of ostrich M. iliofibularis meat at 4oC and that it participated in myofibril degradation of post-mortem muscle, but to a small degree. These results support the proposal that the proteasome comes into play after the calpains have initiated degradation. However, there was a lack of improvement in tenderness values and minimal myofibrillar degradation over the 12-day storage period of the ostrich M. iliofibularis meat, leading to the conclusion that the tenderisation of this meat was incomplete after 12 days.
- Full Text:
- Date Issued: 2004
Religious nationalism and negotiation : Islamic identity and the resolution of the Israel/Palestine conflic
- Authors: De Villiers, Shirley
- Date: 2004
- Subjects: Arab-Israeli conflict Palestinian Arabs -- Civil rights -- Israel Nationalism -- Middle East Religion and politics -- Middle East Jewish-Arab relations Nationalism -- Religious aspects -- Islam -- History -- 20th century
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2873 , http://hdl.handle.net/10962/d1007815
- Description: The use of violence in the Israel/Palestine conflict has been justified and legitimised by an appeal to religion. Militant Islamist organisations like Ramas have become central players in the Palestinian political landscape as a result of the popular support that they enjoy. This thesis aims to investigate the reasons for this support by analysing the Israel/Palestine conflict in terms of Ruman Needs Theory. According to this Theory, humans have essential needs that need to be fulfilled in order to ensure survival and development. Among these needs, the need for identity and recognition of identity is of vital importance. This thesis thus explores the concept of identity as a need, and investigates this need as it relates to inter-group conflict. In situating this theory in the Israel/Palestine conflict, the study exammes how organisations like Ramas have Islamised Palestinian national identity in order to garner political support. The central contention, then, is that the primary identity group of the Palestinian population is no longer nationalist, but Islamic/nationalist. In Islamising the conflict with Israel as well as Palestinian identity, Ramas has been able to justify its often indiscriminate use of violence by appealing to religion. The conflict is thus perceived to be one between two absolutes - that of Islam versus Judaism. In considering the conflict as one of identities struggling for survival in a climate of perceived threat, any attempt at resolution of the conflict needs to include a focus on needs-based issues. The problem-solving approach to negotiation allows for parties to consider issues of identity, recognition and security needs, and thus ensures that the root causes of conflicts are addressed, The contention is that this approach is vital to any conflict resolution strategy where identity needs are at stake, and it provides the grounding for the success of more traditional zero-sum bargaining methods. A recognition of Islamic identity in negotiation processes in Israel/Palestine may thus make for a more comprehensive conflict resolution strategy, and make the outcomes of negotiations more acceptable to the people of Palestine, thus undermining the acceptance of violence that exists at present.
- Full Text:
- Date Issued: 2004
- Authors: De Villiers, Shirley
- Date: 2004
- Subjects: Arab-Israeli conflict Palestinian Arabs -- Civil rights -- Israel Nationalism -- Middle East Religion and politics -- Middle East Jewish-Arab relations Nationalism -- Religious aspects -- Islam -- History -- 20th century
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2873 , http://hdl.handle.net/10962/d1007815
- Description: The use of violence in the Israel/Palestine conflict has been justified and legitimised by an appeal to religion. Militant Islamist organisations like Ramas have become central players in the Palestinian political landscape as a result of the popular support that they enjoy. This thesis aims to investigate the reasons for this support by analysing the Israel/Palestine conflict in terms of Ruman Needs Theory. According to this Theory, humans have essential needs that need to be fulfilled in order to ensure survival and development. Among these needs, the need for identity and recognition of identity is of vital importance. This thesis thus explores the concept of identity as a need, and investigates this need as it relates to inter-group conflict. In situating this theory in the Israel/Palestine conflict, the study exammes how organisations like Ramas have Islamised Palestinian national identity in order to garner political support. The central contention, then, is that the primary identity group of the Palestinian population is no longer nationalist, but Islamic/nationalist. In Islamising the conflict with Israel as well as Palestinian identity, Ramas has been able to justify its often indiscriminate use of violence by appealing to religion. The conflict is thus perceived to be one between two absolutes - that of Islam versus Judaism. In considering the conflict as one of identities struggling for survival in a climate of perceived threat, any attempt at resolution of the conflict needs to include a focus on needs-based issues. The problem-solving approach to negotiation allows for parties to consider issues of identity, recognition and security needs, and thus ensures that the root causes of conflicts are addressed, The contention is that this approach is vital to any conflict resolution strategy where identity needs are at stake, and it provides the grounding for the success of more traditional zero-sum bargaining methods. A recognition of Islamic identity in negotiation processes in Israel/Palestine may thus make for a more comprehensive conflict resolution strategy, and make the outcomes of negotiations more acceptable to the people of Palestine, thus undermining the acceptance of violence that exists at present.
- Full Text:
- Date Issued: 2004
Replacing maize with barley in concetrates fed to jersey cows grazing on kikuyu/ryegrass pasture
- Authors: Lehmann, Maryna
- Date: 2004
- Subjects: Jersey cattle -- Feeding and feeds , Dairy cattle -- Feeding and feeds
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10732 , http://hdl.handle.net/10948/181 , Jersey cattle -- Feeding and feeds , Dairy cattle -- Feeding and feeds
- Description: The aim of the first study was to determine if barley could replace maize as an energy source in concentrates fed to dairy cows grazing on kikuyu/ryegrass pasture without affecting the milk production, milk composition, or cause metabolic disorders. Sixty Jersey cows, in early to mid lactation were randomly allocated to one of five treatments (n = 12) based on feeding concentrates with different ratios of maize to barley, ranging from 100:0, 75:25, 50:50, 25:75 and 0:100, respectively. Concentrates contained 12 MJ ME kg -1 and 130g CP kg-1 DM and cows were fed 3 kg (as-is) concentrate after each milking for a period of 42 days (14-day adaptation and 28-day measurement). Cows strip-grazed the irrigated kikuyu/ryegrass pastures (15.7 ± 1.8 percent DM; 20.2 ± 4.3 percent CP; 44.7 ± 3.5 percent NDF). Milk weights were recorded daily and milk samples collected weekly and analyzed for milk fat and protein content. Body condition score and live weight were recorded at the start and end of the experimental period. Data of all the studies were subjected to a one-way ANOVA. Daily milk yield, FCM, MUN, milk fat yield, milk fat percent, protein yield, protein percent, live weight change, or body condition score change were not affected by treatment and values were 15.8 kg, 17.2 kg, 14.9 mg dl-1, 0.72 kg, 4.56 percent, 0.59 kg, 3.77 percent, 6.67 kg, and 0.15 BCS; 15.6 kg, 17.4 kg, 15.2 mg dl-1, 0.73 kg, 4.3 percent, 0.57 kg, 3.71 percent, 1.33 kg and 0.04 BCS; 17.2 kg, 17.9 kg, 15.2 mg dl-1, 0.74 kg, 4.36 percent, 0.63 kg, 3.71 percent, 0.33 kg and 0.08 BCS; 15.6 kg, 16.4 kg, 15.5 mg dl-1, 0.67 kg, 4.33 percent, 0.60 kg, 3.83 percent, -1.46 kg and 0.11 BCS; and 15.0 kg, 16.0 kg, 15.5 mg dl-1, 0.67 kg, 4.57 percent, 0.57 kg, 3.85 percent, 8.86 kg, and 0.05 BCS, respectively for the cows fed 100:0, 75:25, 50:50, 25:75 and 0:100 maize to barley ratio concentrate. According to these results, barley can replace maize without significantly affecting the milk production or milk composition. None of the cows presented any visible symptoms of acidosis. As it was clear from the results in the first study that maize could replace barley the aim of study 2A was therefore focused on determining the effect of feeding different levels of such a barley-based (2.4, 4.8 or 7.2 kg cow-1day-1) concentrate, on milk production, milk composition and live weight change of Jersey cows on kikuyu/ryegrass pasture (23.1 ± 2.95 percent DM, 11.1 ± 0.11 percent CP, 60.8 ± 0.58 percent NDF). Forty-five Jersey cows (early- to mid lactation), were randomly allocated to one of three treatments (n = 15) involving different levels of concentrate (12 MJ ME and 130g CP kg-1 DM) feeding for a period of 42 days (14-day adaptation and 28-day measurement). Milk weights were also recorded daily, and milk samples collected weekly, and analyzed for milk fat and protein. Body condition score and live weight were recorded at the start and end of the experimental period. The results of this study indicated that increasing the concentrate level from 2.4 to 4.8 and 7.2kg cow-1day-1 did not increase the milk yield (14.0 kg, 15.2 kg, 14.4 kg; P = 0.19). The FCM production increased from 15.8 to 17.5kg (P = 0.04) as the concentrate level increased from 2.4 to 4.8kg cow-1day-1. Increasing the concentrate from 4.8 to 7.2kg cow-1day-1 did not result in a significant increase in FCM. The milk protein percent increased significantly from 3.4 - 3.6 percent when the concentrate feeding level was increased from 2.4 to 7.2kg cow-1day-1. The MUN levels were 17.09 mg dl-1, 16.03 5 mg dl-1, and 16.36 mg dl-1 for the 2.4, 4.8 and 7.2kg cow-1day-1 concentrate levels, respectively. This is well within the recommended MUN levels (12 – 18 mg dl-1) indicating that sufficient protein was fed to cows. Increasing the concentrate level from 4.8 to 7.2 kg cow-1day-1 did not increase production, probably due to a higher pasture substitution rate. Supplementing large quantities of rapidly fermentable grains, such as barley, can suppress rumen pH and may have a negative effect on the rate and extent of fibre digestion in the rumen. Therefore the aim of study 2B was not only to determine the effect of feeding different levels of a barley-based concentrate, on milk production, milk composition and live weight change, but was also to determine the effect of a low (4.8 kg cow-1day-1) versus a high (7.2 kg cow-1day-1) level of barley-based concentrate supplementation on ruminal DM and NDF degradability of Westerworld ryegrass sampled from the pastures that these cows were grazing on. Sixty Jersey cows (early- to mid lactation), were randomly allocated to one of three treatments (n = 20) involving different levels of concentrate feeding. Concentrate (12 MJ ME, 130g CP kg-1 DM) was fed at 2.4, 4.8 or 7.2 kg cow-1day-1 for a period of 74 days (14-day adaptation and 60-day measurement). These cows stripgrazed irrigated kikuyu/ryegrass pastures (14.7 ± 4.37 percent DM, 25.1 ± 1.53 percent CP, and 44.4 ± 2.58 percent NDF) at a daily pasture allocation of 10 kg DM cow-1. Milk weights were recorded daily and milk samples collected weekly and analyzed for milk fat and protein. Body condition score and live weight were recorded at the start and end of the experimental period. Twelve Jersey cows, fitted with ruminal cannulae, were randomly allocated to two of the three treatments in the production study and received either 2.4 or 7.2 kg cow-1 day-1, of the same barley-based concentrate, in a two-period crossover design. These cows strip-grazed the same irrigated kikuyu/ryegrass pastures as the sixty cows in the production study. Each period consisted of 21 days for adaptation and seven days for data collection. Rumen liquor samples were collected every 4 hours within a 24-hour cycle and repeated once. Rumen pH was measured immediately, recorded, and the supernatant fluid preserved and frozen, pending VFA analysis. The in situ nylon bag technique was used to determine DM and NDF degradation and dried samples of Westerworld ryegrass pasture were incubated for 0, 4, 8, 12, 20, 30, 48, 72 and 96 hours. The data were fitted in the non-linear model p = a + b (1-exp-ct) (Ørskov & McDonald, 1979). Daily milk production, fat corrected milk, milk fat yield and milk fat percent were not affected by treatment and values were 17.3 kg, 18.4 kg, 0.76 kg and 4.42 percent; 19.0 kg, 20.0 kg, 0.82 kg and 4.35 percent; and 18.1 kg, 19.1 kg, 0.79 kg and 4.37 percent for the 2.4, 4.8 and 7.2 kg cow-1 day-1 concentrate treatments, respectively. Milk protein percentage of cows on the 7.2 kg concentrate cow-1 day-1 was significantly higher than that of cows on 4.2 kg concentrate cow-1 day-1 feeding level. Live weight increased significantly as the level of concentrate feeding increased and values were 17.9 kg; and 28.9 kg on the 2.4 and 7.2kg concentrate treatment, respectively. There was a significant increase in the live weight of cows that were fed 7.2 kg cow-1 day-1 (as-is) in comparison to those cows that were fed 2.4 kg concentrate cow-1 day-1 (as-is). This may have resulted from more nutrients being partitioned to live weight gain rather than milk production. No further response in milk production was observed when concentrate daily feeding was increased from 4.8 to 7.2 kg cow-1 day-1. It is postulated that the higher concentrate allowance resulted in a higher substitution rate and lower DMI intake from pasture. 6 There was no significant decline in the rumen pH (6.2 ± 0.4 and 6.2 ± 0.5) when the concentrate level was increased from 2.4 to 7.2 kg cow-1 day-1 (as-is). The total VFA (118.1 ± 45.9 and 139.4 ± 45.6 mmol L-1) and isovalerate (0.009 ± 0.07 and 0.248 ± 0.52 mmol L-1) increased significantly when the concentrate was increased from 2.4 to 7.2 kg cow-1day-1. No other rumen parameters were affected by treatment. Ruminal DM and NDF degradability of the Kikuyu/ryegrass pature were not affected by the level of concentrate supplementation. An increase in the concentrate level from 2.4 to 7.2 kg cow-1day-1 did not reduce degradability of either DM (94.67 ± 5.97, 94.49 ± 5.09; P = 0.919) or NDF (92.15 ± 8.69, 94.4 ± 11.73; P = 0.451), respectively. Results of rumen parameters and PD values were within the range reported by Bargo et al., (2003), viz. pH 5.76 – 6.29, NH3-N concentration 8.7 – 32.2 mg dl-1, total VFA concentration 90.3 - 151.4 mmol L-1 and PD values 89.5 – 93.5 % reported by Bargo et al. (2003). According to these authors, there is no simple relationship between any amount of the concentrate supplemented, and the ruminal pH and concentrate feeding only affects the in situ ruminal digestion of pasture when it is fed, at quantities higher than 8 kg DM cow-1day-1 (Bargo et al., 2003).
- Full Text:
- Date Issued: 2004
- Authors: Lehmann, Maryna
- Date: 2004
- Subjects: Jersey cattle -- Feeding and feeds , Dairy cattle -- Feeding and feeds
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10732 , http://hdl.handle.net/10948/181 , Jersey cattle -- Feeding and feeds , Dairy cattle -- Feeding and feeds
- Description: The aim of the first study was to determine if barley could replace maize as an energy source in concentrates fed to dairy cows grazing on kikuyu/ryegrass pasture without affecting the milk production, milk composition, or cause metabolic disorders. Sixty Jersey cows, in early to mid lactation were randomly allocated to one of five treatments (n = 12) based on feeding concentrates with different ratios of maize to barley, ranging from 100:0, 75:25, 50:50, 25:75 and 0:100, respectively. Concentrates contained 12 MJ ME kg -1 and 130g CP kg-1 DM and cows were fed 3 kg (as-is) concentrate after each milking for a period of 42 days (14-day adaptation and 28-day measurement). Cows strip-grazed the irrigated kikuyu/ryegrass pastures (15.7 ± 1.8 percent DM; 20.2 ± 4.3 percent CP; 44.7 ± 3.5 percent NDF). Milk weights were recorded daily and milk samples collected weekly and analyzed for milk fat and protein content. Body condition score and live weight were recorded at the start and end of the experimental period. Data of all the studies were subjected to a one-way ANOVA. Daily milk yield, FCM, MUN, milk fat yield, milk fat percent, protein yield, protein percent, live weight change, or body condition score change were not affected by treatment and values were 15.8 kg, 17.2 kg, 14.9 mg dl-1, 0.72 kg, 4.56 percent, 0.59 kg, 3.77 percent, 6.67 kg, and 0.15 BCS; 15.6 kg, 17.4 kg, 15.2 mg dl-1, 0.73 kg, 4.3 percent, 0.57 kg, 3.71 percent, 1.33 kg and 0.04 BCS; 17.2 kg, 17.9 kg, 15.2 mg dl-1, 0.74 kg, 4.36 percent, 0.63 kg, 3.71 percent, 0.33 kg and 0.08 BCS; 15.6 kg, 16.4 kg, 15.5 mg dl-1, 0.67 kg, 4.33 percent, 0.60 kg, 3.83 percent, -1.46 kg and 0.11 BCS; and 15.0 kg, 16.0 kg, 15.5 mg dl-1, 0.67 kg, 4.57 percent, 0.57 kg, 3.85 percent, 8.86 kg, and 0.05 BCS, respectively for the cows fed 100:0, 75:25, 50:50, 25:75 and 0:100 maize to barley ratio concentrate. According to these results, barley can replace maize without significantly affecting the milk production or milk composition. None of the cows presented any visible symptoms of acidosis. As it was clear from the results in the first study that maize could replace barley the aim of study 2A was therefore focused on determining the effect of feeding different levels of such a barley-based (2.4, 4.8 or 7.2 kg cow-1day-1) concentrate, on milk production, milk composition and live weight change of Jersey cows on kikuyu/ryegrass pasture (23.1 ± 2.95 percent DM, 11.1 ± 0.11 percent CP, 60.8 ± 0.58 percent NDF). Forty-five Jersey cows (early- to mid lactation), were randomly allocated to one of three treatments (n = 15) involving different levels of concentrate (12 MJ ME and 130g CP kg-1 DM) feeding for a period of 42 days (14-day adaptation and 28-day measurement). Milk weights were also recorded daily, and milk samples collected weekly, and analyzed for milk fat and protein. Body condition score and live weight were recorded at the start and end of the experimental period. The results of this study indicated that increasing the concentrate level from 2.4 to 4.8 and 7.2kg cow-1day-1 did not increase the milk yield (14.0 kg, 15.2 kg, 14.4 kg; P = 0.19). The FCM production increased from 15.8 to 17.5kg (P = 0.04) as the concentrate level increased from 2.4 to 4.8kg cow-1day-1. Increasing the concentrate from 4.8 to 7.2kg cow-1day-1 did not result in a significant increase in FCM. The milk protein percent increased significantly from 3.4 - 3.6 percent when the concentrate feeding level was increased from 2.4 to 7.2kg cow-1day-1. The MUN levels were 17.09 mg dl-1, 16.03 5 mg dl-1, and 16.36 mg dl-1 for the 2.4, 4.8 and 7.2kg cow-1day-1 concentrate levels, respectively. This is well within the recommended MUN levels (12 – 18 mg dl-1) indicating that sufficient protein was fed to cows. Increasing the concentrate level from 4.8 to 7.2 kg cow-1day-1 did not increase production, probably due to a higher pasture substitution rate. Supplementing large quantities of rapidly fermentable grains, such as barley, can suppress rumen pH and may have a negative effect on the rate and extent of fibre digestion in the rumen. Therefore the aim of study 2B was not only to determine the effect of feeding different levels of a barley-based concentrate, on milk production, milk composition and live weight change, but was also to determine the effect of a low (4.8 kg cow-1day-1) versus a high (7.2 kg cow-1day-1) level of barley-based concentrate supplementation on ruminal DM and NDF degradability of Westerworld ryegrass sampled from the pastures that these cows were grazing on. Sixty Jersey cows (early- to mid lactation), were randomly allocated to one of three treatments (n = 20) involving different levels of concentrate feeding. Concentrate (12 MJ ME, 130g CP kg-1 DM) was fed at 2.4, 4.8 or 7.2 kg cow-1day-1 for a period of 74 days (14-day adaptation and 60-day measurement). These cows stripgrazed irrigated kikuyu/ryegrass pastures (14.7 ± 4.37 percent DM, 25.1 ± 1.53 percent CP, and 44.4 ± 2.58 percent NDF) at a daily pasture allocation of 10 kg DM cow-1. Milk weights were recorded daily and milk samples collected weekly and analyzed for milk fat and protein. Body condition score and live weight were recorded at the start and end of the experimental period. Twelve Jersey cows, fitted with ruminal cannulae, were randomly allocated to two of the three treatments in the production study and received either 2.4 or 7.2 kg cow-1 day-1, of the same barley-based concentrate, in a two-period crossover design. These cows strip-grazed the same irrigated kikuyu/ryegrass pastures as the sixty cows in the production study. Each period consisted of 21 days for adaptation and seven days for data collection. Rumen liquor samples were collected every 4 hours within a 24-hour cycle and repeated once. Rumen pH was measured immediately, recorded, and the supernatant fluid preserved and frozen, pending VFA analysis. The in situ nylon bag technique was used to determine DM and NDF degradation and dried samples of Westerworld ryegrass pasture were incubated for 0, 4, 8, 12, 20, 30, 48, 72 and 96 hours. The data were fitted in the non-linear model p = a + b (1-exp-ct) (Ørskov & McDonald, 1979). Daily milk production, fat corrected milk, milk fat yield and milk fat percent were not affected by treatment and values were 17.3 kg, 18.4 kg, 0.76 kg and 4.42 percent; 19.0 kg, 20.0 kg, 0.82 kg and 4.35 percent; and 18.1 kg, 19.1 kg, 0.79 kg and 4.37 percent for the 2.4, 4.8 and 7.2 kg cow-1 day-1 concentrate treatments, respectively. Milk protein percentage of cows on the 7.2 kg concentrate cow-1 day-1 was significantly higher than that of cows on 4.2 kg concentrate cow-1 day-1 feeding level. Live weight increased significantly as the level of concentrate feeding increased and values were 17.9 kg; and 28.9 kg on the 2.4 and 7.2kg concentrate treatment, respectively. There was a significant increase in the live weight of cows that were fed 7.2 kg cow-1 day-1 (as-is) in comparison to those cows that were fed 2.4 kg concentrate cow-1 day-1 (as-is). This may have resulted from more nutrients being partitioned to live weight gain rather than milk production. No further response in milk production was observed when concentrate daily feeding was increased from 4.8 to 7.2 kg cow-1 day-1. It is postulated that the higher concentrate allowance resulted in a higher substitution rate and lower DMI intake from pasture. 6 There was no significant decline in the rumen pH (6.2 ± 0.4 and 6.2 ± 0.5) when the concentrate level was increased from 2.4 to 7.2 kg cow-1 day-1 (as-is). The total VFA (118.1 ± 45.9 and 139.4 ± 45.6 mmol L-1) and isovalerate (0.009 ± 0.07 and 0.248 ± 0.52 mmol L-1) increased significantly when the concentrate was increased from 2.4 to 7.2 kg cow-1day-1. No other rumen parameters were affected by treatment. Ruminal DM and NDF degradability of the Kikuyu/ryegrass pature were not affected by the level of concentrate supplementation. An increase in the concentrate level from 2.4 to 7.2 kg cow-1day-1 did not reduce degradability of either DM (94.67 ± 5.97, 94.49 ± 5.09; P = 0.919) or NDF (92.15 ± 8.69, 94.4 ± 11.73; P = 0.451), respectively. Results of rumen parameters and PD values were within the range reported by Bargo et al., (2003), viz. pH 5.76 – 6.29, NH3-N concentration 8.7 – 32.2 mg dl-1, total VFA concentration 90.3 - 151.4 mmol L-1 and PD values 89.5 – 93.5 % reported by Bargo et al. (2003). According to these authors, there is no simple relationship between any amount of the concentrate supplemented, and the ruminal pH and concentrate feeding only affects the in situ ruminal digestion of pasture when it is fed, at quantities higher than 8 kg DM cow-1day-1 (Bargo et al., 2003).
- Full Text:
- Date Issued: 2004
Research portfolio
- Authors: Muituti, J M
- Date: 2004
- Subjects: Education -- Namibia Educational change -- Namibia Curriculum planning -- Namibia Home economics -- Study and teaching -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1736 , http://hdl.handle.net/10962/d1003619
- Description: In Namibia, as in many other countries, curriculum changes have resulted from a “highly complex mix of ideological, political, social, philosophical, economic and other influences” (McGee, 1995, cited by Swarts). Over time some influences become stronger while others lose ground. Different conceptions exist as to what school curricula should be. These conceptions are sometimes referred to as “theories of curricular” or ideologies (ibid). Ideologies in general are “belief systems that provide value premises from which decisions about practical educational matters are made” (Eisner, 1994:47). They derive from broad, international perspectives and views. Some views are unproblematic in that they are generally agreed, such as all children should learn to read and write. Others are more controversial and problematic, e.g. whether sex education should be taught in school. As a result of exposure to other views and perspectives, there is overlap between ideologies and no ideology represents a clear-cut concise school of thought. Nevertheless they provide a theoretical basis for the Home Ecology syllabus. This paper will attempt to provide a critical analysis of the Home Ecology syllabus, the socio-historic and economic analysis of the learners for whom the curriculum has been designed and the analysis of the learning environment in which this curriculum is presented. The synthesis, which will link the sections together, and conclusion will draw the threads together. In providing this analysis it is imperative to provide a definition of what a curriculum is. In the broader sense, a curriculum is the offering of socially valued knowledge, skills and attitudes made available to learners through a variety of programmes. Forquin (1995) cited in Swarts (1996:23) has the following to say about curriculum: ‘The concept of curriculum, indeed, implies taking into consideration the whole of the course of studies and not just one aspect or one stage considered separately’. In examining official educational documents, especially curricular documents written after independence, there are signs of continuing traditional emphasis however, this is expected, as Fullan (1991) contends that change does not take place just because it has been decreed and written down in the book of reforms. Change takes time to work its way in.
- Full Text:
- Date Issued: 2004
- Authors: Muituti, J M
- Date: 2004
- Subjects: Education -- Namibia Educational change -- Namibia Curriculum planning -- Namibia Home economics -- Study and teaching -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1736 , http://hdl.handle.net/10962/d1003619
- Description: In Namibia, as in many other countries, curriculum changes have resulted from a “highly complex mix of ideological, political, social, philosophical, economic and other influences” (McGee, 1995, cited by Swarts). Over time some influences become stronger while others lose ground. Different conceptions exist as to what school curricula should be. These conceptions are sometimes referred to as “theories of curricular” or ideologies (ibid). Ideologies in general are “belief systems that provide value premises from which decisions about practical educational matters are made” (Eisner, 1994:47). They derive from broad, international perspectives and views. Some views are unproblematic in that they are generally agreed, such as all children should learn to read and write. Others are more controversial and problematic, e.g. whether sex education should be taught in school. As a result of exposure to other views and perspectives, there is overlap between ideologies and no ideology represents a clear-cut concise school of thought. Nevertheless they provide a theoretical basis for the Home Ecology syllabus. This paper will attempt to provide a critical analysis of the Home Ecology syllabus, the socio-historic and economic analysis of the learners for whom the curriculum has been designed and the analysis of the learning environment in which this curriculum is presented. The synthesis, which will link the sections together, and conclusion will draw the threads together. In providing this analysis it is imperative to provide a definition of what a curriculum is. In the broader sense, a curriculum is the offering of socially valued knowledge, skills and attitudes made available to learners through a variety of programmes. Forquin (1995) cited in Swarts (1996:23) has the following to say about curriculum: ‘The concept of curriculum, indeed, implies taking into consideration the whole of the course of studies and not just one aspect or one stage considered separately’. In examining official educational documents, especially curricular documents written after independence, there are signs of continuing traditional emphasis however, this is expected, as Fullan (1991) contends that change does not take place just because it has been decreed and written down in the book of reforms. Change takes time to work its way in.
- Full Text:
- Date Issued: 2004
Research portfolio
- Authors: Haingura, Paulinus
- Date: 2004
- Subjects: Education -- Namibia Education and state -- Namibia Educational change -- Namibia Education, Secondary -- Namibia Curriculum planning -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1732 , http://hdl.handle.net/10962/d1003615
- Description: The purpose of this research is to evaluate the implementation of the Namibian education policy with particular reference to Senior Secondary education (Grades 11-12) in order to develop analysing skills that will facilitate better understanding of my professional context and enhance my ability to operate within a research environment. The main purpose is to look at the theory that underpins the curriculum and to find out whether that theory is carried through into practice. This contextual analysis is also designed to provide baseline data as I subsequently explore my area of research. The specific objectives of the research are to: • conduct interviews with teachers and learners which may reveal ideological differences on how these various actors perceive the curriculum; • analyse specific areas within the curriculum that might reveal the type of theory underpinning the curriculum; • assess the curriculum in order to identify objectives and goals that may affect the implementation of the intended curriculum.
- Full Text:
- Date Issued: 2004
- Authors: Haingura, Paulinus
- Date: 2004
- Subjects: Education -- Namibia Education and state -- Namibia Educational change -- Namibia Education, Secondary -- Namibia Curriculum planning -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1732 , http://hdl.handle.net/10962/d1003615
- Description: The purpose of this research is to evaluate the implementation of the Namibian education policy with particular reference to Senior Secondary education (Grades 11-12) in order to develop analysing skills that will facilitate better understanding of my professional context and enhance my ability to operate within a research environment. The main purpose is to look at the theory that underpins the curriculum and to find out whether that theory is carried through into practice. This contextual analysis is also designed to provide baseline data as I subsequently explore my area of research. The specific objectives of the research are to: • conduct interviews with teachers and learners which may reveal ideological differences on how these various actors perceive the curriculum; • analyse specific areas within the curriculum that might reveal the type of theory underpinning the curriculum; • assess the curriculum in order to identify objectives and goals that may affect the implementation of the intended curriculum.
- Full Text:
- Date Issued: 2004
Research portfolio
- Authors: Hoveka, E P
- Date: 2004
- Subjects: Education -- Namibia Teaching -- Namibia Curriculum planning -- Namibia Educational change -- Namibia English language -- Study and teaching (Secondary) -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1733 , http://hdl.handle.net/10962/d1003616
- Description: The purpose of this study is to look at English Second Language IGCSE Core Curriculum for Grades 11 and 12. The criteria that has been identified and selected for analysis as stipulated by the Ministry of Basic Education and Culture Language policy Document of 1996 reads as follows: The aim of teaching English as a language should be to enable the learners to increase their participation in the learning processes. This aim was selected as the criteria for investigation because the notion of active participation by the learners in the teaching and learning process places the learners in a different perspective. In other words, the learners are to be seen as possessors of knowledge rather than ‘empty vessels’ as depicted by the behaviourist approach (Van Harmelen 1999). This idea of a learner-centred approach as embedded in Social Constructivism approach is the foundation on which the Namibian Education Reform Process is based. The justification for selecting these particular criteria for close inspection in the English Second Language Curriculum was sparked by the professional attachment of the researcher into teaching English Second Language to Grades 11 and 12 at the Herman Gmeiner Technical School in Swakopmund. The researcher is also serving as a subject head for this particular discipline. Furthermore, evaluating and analyzing the English Second Language curriculum on this particular objective, the researcher hopes to uncover or come to an understanding of how our educational practices have moved from what was practiced under the behavioural approach and to discover the needs of teachers in terms of implementing the new curriculum in their daily practices as educators. Having the criteria stated, the study will focus on how the data was collected and the type of methodology used to gather this information.
- Full Text:
- Date Issued: 2004
- Authors: Hoveka, E P
- Date: 2004
- Subjects: Education -- Namibia Teaching -- Namibia Curriculum planning -- Namibia Educational change -- Namibia English language -- Study and teaching (Secondary) -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1733 , http://hdl.handle.net/10962/d1003616
- Description: The purpose of this study is to look at English Second Language IGCSE Core Curriculum for Grades 11 and 12. The criteria that has been identified and selected for analysis as stipulated by the Ministry of Basic Education and Culture Language policy Document of 1996 reads as follows: The aim of teaching English as a language should be to enable the learners to increase their participation in the learning processes. This aim was selected as the criteria for investigation because the notion of active participation by the learners in the teaching and learning process places the learners in a different perspective. In other words, the learners are to be seen as possessors of knowledge rather than ‘empty vessels’ as depicted by the behaviourist approach (Van Harmelen 1999). This idea of a learner-centred approach as embedded in Social Constructivism approach is the foundation on which the Namibian Education Reform Process is based. The justification for selecting these particular criteria for close inspection in the English Second Language Curriculum was sparked by the professional attachment of the researcher into teaching English Second Language to Grades 11 and 12 at the Herman Gmeiner Technical School in Swakopmund. The researcher is also serving as a subject head for this particular discipline. Furthermore, evaluating and analyzing the English Second Language curriculum on this particular objective, the researcher hopes to uncover or come to an understanding of how our educational practices have moved from what was practiced under the behavioural approach and to discover the needs of teachers in terms of implementing the new curriculum in their daily practices as educators. Having the criteria stated, the study will focus on how the data was collected and the type of methodology used to gather this information.
- Full Text:
- Date Issued: 2004
Research portfolio
- Authors: Kruger, H J M
- Date: 2004
- Subjects: Mathematics -- Study and teaching (Elementary) -- Namibia Problem solving -- Study and teaching (Elementary) -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1874 , http://hdl.handle.net/10962/d1005629
- Description: Paper 1. The purpose of this analysis is to critically evaluate the Lower Primary Mathematics programme within the context of the Namibian educational reform, against the backdrop of learner-centred education from within the Constructivist epistemology. Through the analysis of a small-scale survey, I will try to determine the extent to which learners, teachers and other educationalists, involved in the Lower Primary school phase, understand the new approach to Mathematics and their pedagogical and theoretical insight into the new programme. I will also analyse the syllabus documents in view of the educational policies and further discuss the social, historical and economic background to the reform. I will then analyse the progress or development of the reform process through discussing the learning environment as well as the learners who are the central participants in education. Paper 2.This critical discussion aims to explore the prospects and underlying principles of the epistemologies of two opposing paradigms of education: Behaviourism and Constructivism. I have critically examined and compared the theoretical aspects that shape and inform the model of instruction and the systemic implications of the learning process. The purpose was to compare both learning theories and to draw a conclusion of which the better epistemology is for the teaching and learning process. Paper 3. This is an investigation into the theories that underpin and inform mathematics teaching in the Lower Primary phase of the primary school in Namibia. The Namibian society requires the development of knowledge and understanding, skills and competencies, attitudes and values, which everyone must have to be able to function adequately in society on a social, economic and political level (MBESC 1996). We need to seek ways of enhancing mathematics teaching in Namibia if we want to live up to the expectations of our society. Paper 4. Mathematicians and researchers across the globe have theorised and speculated about education reform movements, which aim for more than just structural knowledge where it concerns Mathematics. This action research study is based on the findings of a pilot study about 'Problem-based Learning', using this as a basis to investigate the relationship between the intentions of the Lower Primary Mathematics curriculum and its implementation at classroom level. This paper reports on a case study of two grade one teachers' perceptions of problem solving as a key component of Mathematics learning and how the implementation of the problem-based approach could be supported through intervention. Data was gathered from a series of cycles of planning, acting, observing and reflecting. Analysis of the data indicates that teachers' professional development lies within a willingness to change and in reflexive practice. Given focused support to teachers could result in the application of contemporary approaches to Mathematics teaching, with an overall improvement of constructivist-oriented learner-centred education.
- Full Text:
- Date Issued: 2004
- Authors: Kruger, H J M
- Date: 2004
- Subjects: Mathematics -- Study and teaching (Elementary) -- Namibia Problem solving -- Study and teaching (Elementary) -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1874 , http://hdl.handle.net/10962/d1005629
- Description: Paper 1. The purpose of this analysis is to critically evaluate the Lower Primary Mathematics programme within the context of the Namibian educational reform, against the backdrop of learner-centred education from within the Constructivist epistemology. Through the analysis of a small-scale survey, I will try to determine the extent to which learners, teachers and other educationalists, involved in the Lower Primary school phase, understand the new approach to Mathematics and their pedagogical and theoretical insight into the new programme. I will also analyse the syllabus documents in view of the educational policies and further discuss the social, historical and economic background to the reform. I will then analyse the progress or development of the reform process through discussing the learning environment as well as the learners who are the central participants in education. Paper 2.This critical discussion aims to explore the prospects and underlying principles of the epistemologies of two opposing paradigms of education: Behaviourism and Constructivism. I have critically examined and compared the theoretical aspects that shape and inform the model of instruction and the systemic implications of the learning process. The purpose was to compare both learning theories and to draw a conclusion of which the better epistemology is for the teaching and learning process. Paper 3. This is an investigation into the theories that underpin and inform mathematics teaching in the Lower Primary phase of the primary school in Namibia. The Namibian society requires the development of knowledge and understanding, skills and competencies, attitudes and values, which everyone must have to be able to function adequately in society on a social, economic and political level (MBESC 1996). We need to seek ways of enhancing mathematics teaching in Namibia if we want to live up to the expectations of our society. Paper 4. Mathematicians and researchers across the globe have theorised and speculated about education reform movements, which aim for more than just structural knowledge where it concerns Mathematics. This action research study is based on the findings of a pilot study about 'Problem-based Learning', using this as a basis to investigate the relationship between the intentions of the Lower Primary Mathematics curriculum and its implementation at classroom level. This paper reports on a case study of two grade one teachers' perceptions of problem solving as a key component of Mathematics learning and how the implementation of the problem-based approach could be supported through intervention. Data was gathered from a series of cycles of planning, acting, observing and reflecting. Analysis of the data indicates that teachers' professional development lies within a willingness to change and in reflexive practice. Given focused support to teachers could result in the application of contemporary approaches to Mathematics teaching, with an overall improvement of constructivist-oriented learner-centred education.
- Full Text:
- Date Issued: 2004
Research portfolio
- Authors: Mungongi, Fillemon
- Date: 2004
- Subjects: Education, Elementary -- Namibia Teaching -- Namibia Educational change -- Namibia English language -- Study and teaching (Elementary) -- Namibia Curriculum planning -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1937 , http://hdl.handle.net/10962/d1007716
- Description: 1. The contextual analysis and curriculum evaluation. This paper ... aims to investigate the Upper Primary Education Curriculum with specific emphasis on the subject syllabus for English Grades 5- 7. The paper shall attempt to look at the rationale, goals and aims as well as the learning content located in this subject curriculum. It will further investigate the sociohistoric and economic context in which this curriculum has been designed; the learners for whom the curriculum is designed and the learning environment in which the curriculum is presented. 2. The epistemological foundation of the reform process. This paper attempts to explore the theory of knowledge that underpins the practices of behaviourism and constructivism. 3. The literature review. The purpose of this literature review is to examine the effect of methodology in teaching English as a second language in primary schools. It is to find out the ways of teaching English that can produce good results. It is also to find the styles of teaching English as a second language that make some teachers less effective so that such teaching styles can be discouraged. When English was introduced as the medium of instruction in Namibian schools, primary school teachers were retrained and upgraded. 4. The research proposal. The aim of the proposed study is to explore a selection of learners' perceptions of ESL classroom teaching and learning activities. Through this it is hoped to cause greater illumination on the nature of learning and teaching English. 5. The empirical study (research paper). This interpretative case study hoped to find out from learners themselves about their perceptions of ESL classroom teaching and learning activities. A variety of research tools were used, including questionnaires, interviews, observations, interactive workshops and focus group discussions, all of which provided a rich source of data for interpretation. The research findings of this study clearly indicated that there is a mismatch between the teachers and learners' perceptions about the language skills and tasks encountered in the classrooms. From what was gained from the participants in this research, tentative suggestions are made.
- Full Text:
- Date Issued: 2004
- Authors: Mungongi, Fillemon
- Date: 2004
- Subjects: Education, Elementary -- Namibia Teaching -- Namibia Educational change -- Namibia English language -- Study and teaching (Elementary) -- Namibia Curriculum planning -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1937 , http://hdl.handle.net/10962/d1007716
- Description: 1. The contextual analysis and curriculum evaluation. This paper ... aims to investigate the Upper Primary Education Curriculum with specific emphasis on the subject syllabus for English Grades 5- 7. The paper shall attempt to look at the rationale, goals and aims as well as the learning content located in this subject curriculum. It will further investigate the sociohistoric and economic context in which this curriculum has been designed; the learners for whom the curriculum is designed and the learning environment in which the curriculum is presented. 2. The epistemological foundation of the reform process. This paper attempts to explore the theory of knowledge that underpins the practices of behaviourism and constructivism. 3. The literature review. The purpose of this literature review is to examine the effect of methodology in teaching English as a second language in primary schools. It is to find out the ways of teaching English that can produce good results. It is also to find the styles of teaching English as a second language that make some teachers less effective so that such teaching styles can be discouraged. When English was introduced as the medium of instruction in Namibian schools, primary school teachers were retrained and upgraded. 4. The research proposal. The aim of the proposed study is to explore a selection of learners' perceptions of ESL classroom teaching and learning activities. Through this it is hoped to cause greater illumination on the nature of learning and teaching English. 5. The empirical study (research paper). This interpretative case study hoped to find out from learners themselves about their perceptions of ESL classroom teaching and learning activities. A variety of research tools were used, including questionnaires, interviews, observations, interactive workshops and focus group discussions, all of which provided a rich source of data for interpretation. The research findings of this study clearly indicated that there is a mismatch between the teachers and learners' perceptions about the language skills and tasks encountered in the classrooms. From what was gained from the participants in this research, tentative suggestions are made.
- Full Text:
- Date Issued: 2004
Research portfolio
- Authors: Gontes, Karolina
- Date: 2004
- Subjects: Curriculum planning -- Namibia African languages -- Study and teaching -- Namibia Language and languages -- Study and teaching -- Curricula--Namibia Language and education -- Namibia Language policy -- Namibia Nama language -- Study and teaching -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1731 , http://hdl.handle.net/10962/d1003614
- Description: The purpose of the study is to investigate how mother tongue instruction influences the learner performance in the acquisition of reading and comprehension skills of Khoekhoegowab speaking learners in Grade 2 in comparison with foreign medium of instruction. (p. 1)
- Full Text:
- Date Issued: 2004
- Authors: Gontes, Karolina
- Date: 2004
- Subjects: Curriculum planning -- Namibia African languages -- Study and teaching -- Namibia Language and languages -- Study and teaching -- Curricula--Namibia Language and education -- Namibia Language policy -- Namibia Nama language -- Study and teaching -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1731 , http://hdl.handle.net/10962/d1003614
- Description: The purpose of the study is to investigate how mother tongue instruction influences the learner performance in the acquisition of reading and comprehension skills of Khoekhoegowab speaking learners in Grade 2 in comparison with foreign medium of instruction. (p. 1)
- Full Text:
- Date Issued: 2004
Research portfolio
- Authors: Katewa, E N M
- Date: 2004
- Subjects: Rundu College of Education (Namibia) Education -- Namibia Educational change -- Namibia College teachers -- Training of -- Namibia Curriculum planning -- Namibia Curriculum change -- Namibia Teaching -- Namibia Universities and colleges -- Namibia -- Curricula
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1734 , http://hdl.handle.net/10962/d1003617
- Description: The purpose of this study is to investigate the contradiction between the teaching of integration in ETP and the actual practice of compartmentalisation within ETP at the Rundu College of Education. The second part of this study is to explore and examine the way teacher educators could integrate subjects into their specialisation areas at college level. It is hoped that this study will contribute to the following: • The reason (s) why there is a contradiction between the teaching in ETP and the actual practice of compartmentalisation within the ETP. • Examining and investigating factors that have contributed to the teaching in a compartmentalised way.
- Full Text:
- Date Issued: 2004
- Authors: Katewa, E N M
- Date: 2004
- Subjects: Rundu College of Education (Namibia) Education -- Namibia Educational change -- Namibia College teachers -- Training of -- Namibia Curriculum planning -- Namibia Curriculum change -- Namibia Teaching -- Namibia Universities and colleges -- Namibia -- Curricula
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1734 , http://hdl.handle.net/10962/d1003617
- Description: The purpose of this study is to investigate the contradiction between the teaching of integration in ETP and the actual practice of compartmentalisation within ETP at the Rundu College of Education. The second part of this study is to explore and examine the way teacher educators could integrate subjects into their specialisation areas at college level. It is hoped that this study will contribute to the following: • The reason (s) why there is a contradiction between the teaching in ETP and the actual practice of compartmentalisation within the ETP. • Examining and investigating factors that have contributed to the teaching in a compartmentalised way.
- Full Text:
- Date Issued: 2004
Research portfolio
- Authors: Bock, L J
- Date: 2004
- Subjects: Education -- Namibia Educational change -- Namibia Curriculum change -- Namibia College teachers -- Training of -- Namibia Geography -- Study and teaching (Secondary) -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1895 , http://hdl.handle.net/10962/d1006128
- Full Text:
- Date Issued: 2004
- Authors: Bock, L J
- Date: 2004
- Subjects: Education -- Namibia Educational change -- Namibia Curriculum change -- Namibia College teachers -- Training of -- Namibia Geography -- Study and teaching (Secondary) -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1895 , http://hdl.handle.net/10962/d1006128
- Full Text:
- Date Issued: 2004
Research portfolio
- Authors: Amweenye, Fares Frans
- Date: 2004
- Subjects: Education -- Namibia Educational change -- Namibia College teachers -- Training of -- Namibia Curriculum planning -- Namibia Teaching -- Namibia Universities and colleges -- Curricula
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1730 , http://hdl.handle.net/10962/d1003613
- Description: What is the portfolio and what are its purposes? I must define the portfolio as a summative document bearing the valuable experiences learned in a particular course of study. In this context, portfolio can be viewed as a selective entity that represents the level of learning, in terms of academic/professional growth and development, attained in one's participation in a particular course of study such as this Master one I have been attending. Portfolio can be educationally utilized to reflect and evaluate one's learning. As one goes throughout paging, one locates the level of learning achieved in terms of anticipated knowledge, understanding, and experiences, skills and attitudes or overly learning competencies. The level of development one has gone through in attempts to respond to the expected learning outcomes surface out more easily. And if further learning be conducted, the portfolio must as well shows the ways ahead. With these few words, I have attempted to present the portfolio as a useful tool that represents the level of advancement attained in learning. This portfolio comprises of my educational partaking in Rhodes University's master program (theory and practice, in particular what and how I have gained from that program participation. It may also present what I cold not learn. The arrangement of the portfolio contents assumes a progressive procession, being structured in terms of the assignments taken. There are five pieces of assignments in this research portfolio. The first assignment is a contextual analysis of the Education Theory and Practice (ETP) curriculum of our current teacher education program, namely Basic Education Teachers' Diploma. It looks at the theoretical framework that informs and shapes everyday teaching and learning practices, particularly the degree to which we have been able to implement the theoretical perspectives into operational practices. To this is how our college is equipped with the technologies necessary for possible practices of the curriculum. The other emphasis focuses at the historical backgrounds that necessitated the undertaking of the BETD as an instrument of reforming and transforming the basic education rightly at the independence. The other area is on the question of how the curriculum or program intakers, the entering students, have been prepared to consume the curriculum program. Since the program has been as well designed to address and meet the four major national goals of education for all, another part has been focused on these goals so far as to locate the degree of attainment. The second assignment is about contrasting and comparing the two main held dominant worldwide views of knowledge- namely behaviorism and constructivism. Each branch of knowledge is looked at firstly with particular attentions paid to its own individual versions of knowledge and its development and acquisition. The other focuses examine which base seems to offer better explanations of what knowledge is and how it can best be constructed and acquired in any educational setting. The third assignment is that of literature review. I have chosen action as an area that I would be interested in exploring much further. Action research is what eventually became a part of my research proposal in which I would research on how our college students carry out their action research projects to examine their own classroom makings. It has been therefore important to read what others have written about this field and locate the lessons that can be illuminated on our own curriculum context. The literature review paves the way to the research proposal. The research proposal or a research plan as I would often call it, sets the context, purpose, theoretical position and information gathering methods under which the research process will take place. The research proposal has thus been the navigating compass despite the that realities as the practical journey itself took off some deviation unavoidably came in as necessitated by the underlying research process itself. The research proposal finally accumulates into the sought, the final assignment. A critical view illustrates that this piece is actually another contextual inquiry like the first work only that this is viewing our supposed curriculum outcomes: our students, our products and how they have been equipped to carry out the research. Their research, with its successes and shortcomings, I have concluded, firmly serves to reflect the kind of education delivered from our teacher colleges. The portfolio contents also demonstrate the course orientation: focusing on one's professional field. At end, I see this research portfolio as myself, a mirror that reflects my academic and professional participation in Rhodes University's world and its vision and mission expresses in the theme of where leaders learn. It thus represents the personal, academic and development accomplished throughout this Masters' course. In the other way around, I see it as reflecting what Rhodes can offer as from when the prestigious Augustana College, my American institution, has prepared after its boundaries.
- Full Text:
- Date Issued: 2004
- Authors: Amweenye, Fares Frans
- Date: 2004
- Subjects: Education -- Namibia Educational change -- Namibia College teachers -- Training of -- Namibia Curriculum planning -- Namibia Teaching -- Namibia Universities and colleges -- Curricula
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1730 , http://hdl.handle.net/10962/d1003613
- Description: What is the portfolio and what are its purposes? I must define the portfolio as a summative document bearing the valuable experiences learned in a particular course of study. In this context, portfolio can be viewed as a selective entity that represents the level of learning, in terms of academic/professional growth and development, attained in one's participation in a particular course of study such as this Master one I have been attending. Portfolio can be educationally utilized to reflect and evaluate one's learning. As one goes throughout paging, one locates the level of learning achieved in terms of anticipated knowledge, understanding, and experiences, skills and attitudes or overly learning competencies. The level of development one has gone through in attempts to respond to the expected learning outcomes surface out more easily. And if further learning be conducted, the portfolio must as well shows the ways ahead. With these few words, I have attempted to present the portfolio as a useful tool that represents the level of advancement attained in learning. This portfolio comprises of my educational partaking in Rhodes University's master program (theory and practice, in particular what and how I have gained from that program participation. It may also present what I cold not learn. The arrangement of the portfolio contents assumes a progressive procession, being structured in terms of the assignments taken. There are five pieces of assignments in this research portfolio. The first assignment is a contextual analysis of the Education Theory and Practice (ETP) curriculum of our current teacher education program, namely Basic Education Teachers' Diploma. It looks at the theoretical framework that informs and shapes everyday teaching and learning practices, particularly the degree to which we have been able to implement the theoretical perspectives into operational practices. To this is how our college is equipped with the technologies necessary for possible practices of the curriculum. The other emphasis focuses at the historical backgrounds that necessitated the undertaking of the BETD as an instrument of reforming and transforming the basic education rightly at the independence. The other area is on the question of how the curriculum or program intakers, the entering students, have been prepared to consume the curriculum program. Since the program has been as well designed to address and meet the four major national goals of education for all, another part has been focused on these goals so far as to locate the degree of attainment. The second assignment is about contrasting and comparing the two main held dominant worldwide views of knowledge- namely behaviorism and constructivism. Each branch of knowledge is looked at firstly with particular attentions paid to its own individual versions of knowledge and its development and acquisition. The other focuses examine which base seems to offer better explanations of what knowledge is and how it can best be constructed and acquired in any educational setting. The third assignment is that of literature review. I have chosen action as an area that I would be interested in exploring much further. Action research is what eventually became a part of my research proposal in which I would research on how our college students carry out their action research projects to examine their own classroom makings. It has been therefore important to read what others have written about this field and locate the lessons that can be illuminated on our own curriculum context. The literature review paves the way to the research proposal. The research proposal or a research plan as I would often call it, sets the context, purpose, theoretical position and information gathering methods under which the research process will take place. The research proposal has thus been the navigating compass despite the that realities as the practical journey itself took off some deviation unavoidably came in as necessitated by the underlying research process itself. The research proposal finally accumulates into the sought, the final assignment. A critical view illustrates that this piece is actually another contextual inquiry like the first work only that this is viewing our supposed curriculum outcomes: our students, our products and how they have been equipped to carry out the research. Their research, with its successes and shortcomings, I have concluded, firmly serves to reflect the kind of education delivered from our teacher colleges. The portfolio contents also demonstrate the course orientation: focusing on one's professional field. At end, I see this research portfolio as myself, a mirror that reflects my academic and professional participation in Rhodes University's world and its vision and mission expresses in the theme of where leaders learn. It thus represents the personal, academic and development accomplished throughout this Masters' course. In the other way around, I see it as reflecting what Rhodes can offer as from when the prestigious Augustana College, my American institution, has prepared after its boundaries.
- Full Text:
- Date Issued: 2004
Research portfolio
- Authors: Boois, Yvonne
- Date: 2004
- Subjects: Education -- Namibia Educational change -- Namibia School libraries -- Namibia Information services -- Namibia Education -- Political aspects -- Namibia Libraries and state -- Namibia Information science -- Study and teaching -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1896 , http://hdl.handle.net/10962/d1006152
- Full Text:
- Date Issued: 2004
- Authors: Boois, Yvonne
- Date: 2004
- Subjects: Education -- Namibia Educational change -- Namibia School libraries -- Namibia Information services -- Namibia Education -- Political aspects -- Namibia Libraries and state -- Namibia Information science -- Study and teaching -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1896 , http://hdl.handle.net/10962/d1006152
- Full Text:
- Date Issued: 2004