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A multiple case study of parent involvement with grade 8 learners of mathematics

  • Authors: Govender, Vasuthavan Gopaul
  • Date: 2007
  • Subjects: Education, Secondary -- Parent participation , Parent-teacher relationships , Mathematics -- Study and teaching (Secondary)
  • Language: English
  • Type: Thesis , Doctoral , DEd
  • Identifier: vital:9556 , http://hdl.handle.net/10948/511 , http://hdl.handle.net/10948/d1011913 , Education, Secondary -- Parent participation , Parent-teacher relationships , Mathematics -- Study and teaching (Secondary)
  • Description: The learning of mathematics is a worldwide concern. International studies over the last decade place South African learners amongst the lowest achievers. Although various initiatives have been tried there does not seem to be any improvement. In the USA and UK initiatives include the involvement of parents and these have been implemented with great success. One of the parent involvement programmes from the USA, the Family Maths Programme has been in South Africa since 1996. This programme has been successful in South Africa but is confined to parents of grades 4-7 children. However, there is no programme for parents of high school learners. As grade 8 is usually the first high school year in South Africa, this study focuses on parents of grade 8 children and their involvement in their children’s mathematics learning. It consists of an initial survey of grade 8 parents’ (from an urban school) mathematical backgrounds and experiences and their involvement in their children’s education. Using key points from the survey and elements from the literature review and other sources, the researcher designed a parent assistance programme for mathematics which was conducted with three groups of parents of grade 8 children from the same high school. Each group of parents was exclusive and the same set of procedures was applied to each group, making this study a qualitative multiple case study, within the interpretive research paradigm. The parent-assistance programme consists of a parents’ workshop and completion of journals over a 7-week period. Parents documented their interactions with their children in structured journals, a process known as participant journaling. After this journaling period, parents and children were surveyed on this interaction by means of follow-up questionnaires. This was followed later in interviews with the parents and mathematics teachers, separately. After the completion of all three case studies parents and children participated in focus group discussions to discuss and share experiences of the programme. The interrogation of the data, on two levels, suggests parents’ and children’s perceptions of mathematics were likely to be positively influenced. The data also suggest that children were likely to become more confident and to improve in mathematics.
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  • Date Issued: 2007

The origins, developments, and current performance practices of African neo-traditional choral music of Southern Africa

  • Authors: De Beer, Rudolf
  • Date: 2007
  • Subjects: Choral music -- Africa, Southern , Music -- Performance -- Africa, Southern
  • Language: English
  • Type: Thesis , Doctoral , DMus
  • Identifier: vital:8514 , http://hdl.handle.net/10948/d1011781 , Choral music -- Africa, Southern , Music -- Performance -- Africa, Southern
  • Description: This study deals with African neo-traditional choral music of sub-Saharan- and Southern Africa, with specific reference to extemporisation. The research focussed on the evolution of this music through an amalgamation of western choral music and African indigenous and traditional musical practices of sub- Saharan and Southern Africa. Specific reference to the syncretism of western music, which came to Africa through colonisation, and the way African indigenous musical traditions influenced it, is preceded by descriptions on African indigenous musical practices and western choral music traditions. The incorporation of traditional folk songs into African makwaya, or “choir music”, was inevitable. This development saw the birth of African neotraditional choral music as a formal part of many choirs’ programmes. A description of five sample choirs engaging with this music was followed by a case study on the Drakensberg Boys’ Choir. The way these choirs deal with different aspects regarding the preparation and performance of this music highlighted many parallels with African indigenous traditions. It also emphasises the important role of this music in choral performance, as well as choral education. As a genre in evolution, one aspect of this music, namely extemporisation, was studied in more detail in order to suggest another way of engaging with this music. Not only is choral extemporisation a possibility in African neo-traditional choral music of Southern Africa, but it is also a flourishing art form in Scandinavia. In Norway and Sweden it also utilises characteristics and techniques of folk music, which raised the status of this music to be a major art form. This notion prompted the suggested application of choral extemporisation to African neo-traditional choral music of Southern Africa. Even if any method of extemporisation may be utilised, it is proposed that characteristics of African sub- Saharan- and Southern African indigenous music be applied. This may result in the incorporation of more of these African indigenous elements in the neo-traditional choral music discussed than the current western harmonic emphasis. However, the suggestion is seen as a next step in the evolution of this music, which corresponds with international practices, and not to return to indigenous practices as such.
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  • Date Issued: 2007

Pricing exotic options using C++

  • Authors: Nhongo, Tawuya D R
  • Date: 2007
  • Subjects: C++ (Computer program language) , Monte Carlo method , Simulation methods , Options (Finance) -- Mathematical models , Pricing -- Mathematical models
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5577 , http://hdl.handle.net/10962/d1008373 , C++ (Computer program language) , Monte Carlo method , Simulation methods , Options (Finance) -- Mathematical models , Pricing -- Mathematical models
  • Description: This document demonstrates the use of the C++ programming language as a simulation tool in the efficient pricing of exotic European options. Extensions to the basic problem of simulation pricing are undertaken including variance reduction by conditional expectation, control and antithetic variates. Ultimately we were able to produce a modularized, easily extend-able program which effectively makes use of Monte Carlo simulation techniques to price lookback, Asian and barrier exotic options. Theories of variance reduction were validated except in cases where we used control variates in combination with the other variance reduction techniques in which case we observed increased variance. Again, the main aim of this half thesis was to produce a C++ program which would produce stable pricings of exotic options.
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  • Date Issued: 2007

Surface chemistry and electrocatalytic behaviour of tetra-carboxy substituted iron, cobalt and manganese phthalocyanine monolayers on gold electrode

  • Authors: Mashazi, Philani N , Westbroek, Philippe , Ozoemena, Kenneth I , Nyokong, Tebello
  • Date: 2007
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/268806 , vital:54233 , xlink:href="https://doi.org/10.1016/j.electacta.2007.08.044"
  • Description: Surface chemistry and electrocatalytic properties of self-assembled monolayers of metal tetra-carboxylic acid phthalocyanine complexes with cobalt (Co), iron (Fe) and manganese (Mn) as central metal ions have been studied. These phthalocyanine molecules are immobilized on gold electrode via the coupling reaction between the ring substituents and pre-formed mercaptoethanol self-assembled monolayer (Au-ME SAM). X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy confirmed chemisorption of mercaptoethanol via sulfur group on gold electrode and also coupling reaction between phthalocyanines and Au-ME SAM. Electrochemical parameters of the immobilized molecules show that these molecules are densely packed with a perpendicular orientation. The potential applications of the gold modified electrodes were investigated towards L-cysteine detection and the analysis at phthalocyanine SAMs. Cobalt and iron tetra-carboxylic acid phthalocyanine monolayers showed good oxidation peak for L-cysteine at potentials where metal oxidation (MIII/MII) takes place and this metal oxidation mediates the catalytic oxidation of L-cysteine. Manganese tetra-carboxylic acid phthalocyanine monolayer also exhibited a good catalytic oxidation peak towards L-cysteine at potentials where MnIV/MnIII redox peak occurs and this redox peak mediates L-cysteine oxidation. The analysis of cysteine at phthalocyanine monolayers displayed good analytical parameters with good detection limits of the orders of 10−7 mol L−1 and good linearity for a studied concentration range up to 60 μmol L−1.
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  • Date Issued: 2007

Two issues, two groups:

  • Authors: du Toit, Jeanne
  • Date: 2007
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/159299 , vital:40285 , https://hdl.handle.net/10520/EJC144677
  • Description: One of the conference strategies that I found particularly valuable was that of the "syndicate teams" who met regularly to speak on focused topics. Delegates signed up for the topic they were interested in and stayed with that group for the duration of the conference. The list included topics such as the status of journalism education in the academy; the role of journalism in changing the media; adapting journalism education to a digital age, etc.
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  • Date Issued: 2007

Exploring normal South African and British children: a comparative study utilizing the Griffiths Mental Development Scales- extended revised

  • Authors: Van Heerden, Rivca
  • Date: 2007
  • Subjects: Psychological tests for children -- Cross-cultural studies , Children -- Intelligence testing -- Cross-cultural studies , Griffiths Scales of Mental Development
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:9929 , http://hdl.handle.net/10948/629 , Psychological tests for children -- Cross-cultural studies , Children -- Intelligence testing -- Cross-cultural studies , Griffiths Scales of Mental Development
  • Description: The health status of a substantial number of South African children can be classified as “children at risk” (Luiz, 1999) as the majority of children are influenced by factors such as poverty, poor living conditions and the HIV/AIDS epidemic. These are only some of the influences that contribute significantly to the health status of South African children and consequently their development. It can thus be argued that developmental assessment is imperative in the South African context. One of the most important reasons are that children with special needs in South Africa can be identified and given the opportunity to catch up developmentally and cope successfully as opposed to those who are identified much later (Foxcroft & Roodt, 2006). Furthermore, children in South Africa must begin Grade one in the year in which they turn seven. They may only enter grade one if the school has an opening and if the necessary evidence is provided to the Department of Education that the child will be able to cope with the demands of formal schooling (Department of Education, 2002). Developmental assessment measures therefore needs to be appropriate, accurate and informative in the modern South African context. The need for a measuring instrument to assess children’s overall development and thus their developmental readiness to cope with the demands of formal schooling could be satisfied by the Griffiths Mental Development Scales – Extended Revised (GMDS-ER). This recently revised measure has not been normed on a representative, contemporary South African sample. The purpose of the study was therefore to generate information on the applicability of British norms for the contemporary South African population. This study compared and explored the performance of South African and British children aged 5-years and 6-years on the Griffiths Mental Development Scales - Extended Revised (GMDS-ER). A contemporary South African sample was obtained by testing children between the ages of 5-years and 6-years on the GMDS-ER, whilst the British sample was drawn from the United Kingdom and Eire standardization sample. The British sample was screened for normality and a similar process was followed to establish normality for the South African sample. A matched simple frequency distribution technique (taking into account age, socioeconomic status and gender as variables) was employed to approximate the equivalence between the samples. The profiles were compared by conducting an independent sample t-test with subsequent post hoc analyses to explore potential differences in the performance of the two samples. The major findings of the present study were as follows: 1. There is a significant difference between the South African and British children’s overall developmental profiles (as measured by the GMDS-ER). 2. Generally, South African children performed better on the Locomotor subscale and the Personal Social Subscale (although not statistically significant), whilst British children performed statistically better on the Language, Eye and Hand Co-ordination, and Practical Reasoning Subscales. 3. No significant differences were found for the Performance Subscale which could indicate that South African and British children’s performances on this scale are similar. Further investigations into the applicability of the GMDS-ER for the contemporary South African context are recommended and the establishment of South African norms for clinical utilization is essential. Caution with regard to the utilization of the British–based norms in the South African context is final recommendations.
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  • Date Issued: 2007

Ethnicity and nationalism in urban colonial Zimbabwe : Bulawayo, 1950 to 1963

  • Authors: Msindo, Enocent
  • Date: 2007
  • Language: English
  • Type: Article
  • Identifier: vital:6149 , http://hdl.handle.net/10962/d1006813 , http://dx.doi.org/10.1017/S0021853707002538
  • Description: Zimbabwean historians have not yet fully assessed the interaction of two problematic identities, ethnicity and nationalism, to determine whether the two can work as partners and successfully co-exist. This essay argues that, in Bulawayo during the period studied, ethnicity co-existed with and complemented nationalism rather than the two working as polar opposite identities. Ethnic groups provided both the required leaders who became prominent nationalist figures and the precolonial history, personalities and monuments that sparked the nationalist imagination. From the 1950s, ethnic groups expanded their horizons and provided platforms from which emerging African nationalists launched their agenda. Understanding these interrelationships will reshape our understanding of the workings of these two identities in a cosmopolitan town.
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  • Date Issued: 2007

Electrochemical characterisation of tetra- and octa-substituted oxo(phthalocyaninato)titanium(IV) complexes

  • Authors: Tau, Prudence Lerato , Nyokong, Tebello
  • Date: 2007
  • Language: English
  • Type: Article
  • Identifier: vital:6598 , http://hdl.handle.net/10962/d1004347
  • Description: The synthesis and electrochemical characterisation of the following oxotitanium tetra-substituted phthalocyanines are reported: 1,(4)-(tetrabenzyloxyphthalocyaninato)titanium(IV) oxide (5a); 1,(4)- {tetrakis[4-(benzyloxy)phenoxy]phthalocyaninato}titanium(IV) oxide (5b); 2,(3)- (tetrabenzyloxyphthalocyaninato)titanium(IV) oxide (6a) and 2,(3)-{tetrakis[4- (benzyloxy)phenoxy]phthalocyaninato}titanium(IV) oxide (6b). The electrochemical characterisation of complexes octa-substituted with 4-(benzyloxy)phenoxy (9b), phenoxy (9c) and tert -butylphenoxy (9d) groups is also reported. The cyclic voltammograms of the complexes exhibit reversible couples I–III and couple IV is quasi-reversible for complexes 5a, 5b, 6a and 6b. The first two reductions are metal-based processes, confirmed by spectroelectrochemistry to be due to Ti IV Pc 2 − /Ti III Pc 2 − and Ti III Pc 2 − /Ti II Pc 2 − redox processes and the last two reductions are ring-based processes due to Ti II Pc 2 − /Ti II Pc 3 − and Ti II Pc 3 − /Ti II Pc 4 − . Chronocoulometry confirmed a one-electron transfer at each reduction step. The electrochemistry of the above complexes is also compared to the previously reported 5c, 5d, 6c and 6d.
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  • Date Issued: 2007

The impact of the bill of rights on extradition

  • Authors: Tyler, Robyn Zoe
  • Date: 2007
  • Subjects: Extradition -- South Africa , Criminal procedure -- South Africa
  • Language: English
  • Type: Thesis , Masters , LLM
  • Identifier: vital:10282 , http://hdl.handle.net/10948/830 , Extradition -- South Africa , Criminal procedure -- South Africa
  • Description: The process of extradition is a vital component of International Criminal Law as a means of ensuring the suppression and prevention of international crimes. It is the internationally accepted method used by states to surrender an offender back to the state where the alleged offence was committed so that such offender can be tried and punished. Without such process, and with the ease of modern global travel, offenders would, in all likelihood be able to escape prosecution and punishment. Most organized democratic societies recognize that the suppression of crime is necessary for peace and order in society and that extradition is an effective tool to be used to bring to justice a fugitive attempting to evade the law by fleeing to another country. What follows is a discussion, firstly on the theory of extradition and secondly on the effect that human rights has had on the law of extradition. The theory of extradition involves an analysis of extradition from its ancient roots to its position in society today. With regard to extradition in South Africa, reference is made to the various periods of the country’s history. The colonial era before South Africa acquired Republican status in 1961 is referred to in order to establish a basis for the present law of extradition in South Africa. The period during the apartheid era after achieving Republican status in 1961 is discussed in order to show how and why South Africa moved away from its common law roots based on English Law. This era is also of importance as it led to the introduction of the present Extradition Act 67 of 1962. Finally the current position spanning from 1994 to the law as it stands in South Africa today, as influenced by the introduction of Constitutional law, is examined. The rule on non-inquiry is also examined in order to compare the traditional approach by states, where state sovereignty was of paramount importance, with the modern trend of emphasis being placed on fundamental human rights. The methods in terms of which extradition is accomplished, both in South Africa and internationally is also discussed. Such reference to the theory and nature of extradition is done to provide general background on the complex issue to be discussed. The crux of the treatise relates to the impact that the rise in status of fundamental human rights has had on the extradition process. Reference will be made to aspects relating to the protection of the offender’s procedural rights as well as to the protection of the individuals right to life, dignity and bodily integrity. Such examination will refer to the position in South African law as well as the position on the international front. Attention is given to developments in case law as well as to how the courts approach the tension between extradition and human rights both locally and internationally. Finally, in conclusion it is submitted that the extradition process is the most effective procedure available to return an offender to the state seeking his prosecution. The process has however, in modern times adapted to uphold the rights of the offender whose return is requested. This can be seen from the provisions included in recent treaties and conventions, most notably the European Convention on Extradition to which South Africa became a party in 2003. Extradition is clearly concerned with the balancing of the offender’s human rights and the need for effective enforcement of criminal law.
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  • Date Issued: 2007

Pharmaceutical analysis and quality of complementary medicines : sceletium and associated products

  • Authors: Patnala, Satya Siva Rama Ranganath Srinivas
  • Date: 2007
  • Subjects: Alternative medicine , Herbs -- Therapeutic use
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:3872 , http://hdl.handle.net/10962/d1018263
  • Description: There has been an upsurge in the use of Complementary and Alternate Medicines (CAMs) in both developed and developing countries. Although herbal medicines have been in use for many centuries, their quality, safety and efficacy are still of major concern. Many countries are in the process of integrating CAMs into conventional health care systems based on the knowledge and use of traditional medicines. The quality control (QC) of herbal products usually presents a formidable analytical challenge in view of the complexity of the constituents in plant material and the commercial non-availability of appropriate qualified reference standards. Sceletium, a genus belonging to the family Aizoaceae, has been reported to contain psychoactive alkaloids, specifically mesembrine, mesembrenone, mesembrenol and some other related alkaloids. Sceletium is marketed as dried plant powder and as phyto-pharmaceutical dosage forms. Sceletium products and plant material marketed through health shops and on the internet are associated with unjustified claims of specific therapeutic efficacy and may be of dubious quality. Validated analytical methods to estimate Sceletium alkaloids have not previously been reported in the scientific literature and the available methods have focused only on qualitative estimation. Furthermore, since appropriate markers were not commercially available for use as reference standards, a primary objective of this study was to isolate relevant compounds, qualify them as reference standards which could be applied to develop appropriate validated qualitative and quantitative analytical methods for fingerprinting and assay of Sceletium plant material and dosage forms. The alkaloidal markers mesembrine, mesembrenone and ∆⁷ mesembrenone were isolated by solvent extraction and chromatography from dried plant material. Mesembranol and epimesembranol were synthesised by hydrogenation of the isolated mesembrine using the catalyst platinum (IV) oxide and then further purified by semi-preparative column chromatography. All compounds were subjected to analysis by ¹H, ¹³C, 2-D nuclear magnetic resonance and liquid chromatography-tandem mass spectroscopy. Mesembrine was converted to hydrochloride crystals and mesembranol was isolated as crystals from the hydrogenation reaction mass. These compounds were analysed and characterised by X-ray crystallography. A relatively simple HPLC method for the separation and quantitative analysis of five relevant alkaloidal components in Sceletium was developed and validated. The method was applied to determine the alkaloids in plant material and dosage forms containing Sceletium. An LCMS method developed during the study provided accurate identification of the five relevant Sceletium alkaloids. The method was applied for the quantitative analysis and QC of Sceletium plant material and its dosage forms. This LCMS method was found to efficiently ionize the relevant alkaloidal markers in order to facilitate their detection, identification and quantification in Sceletium plant material as well as for the assay and QC of dosage forms containing Sceletium. The chemotaxonomy of some Sceletium species and commercially available Sceletium dosage forms were successfully studied by the LCMS method. The HPLC and LCMS methods were also used to monitor the bio-conversion of some of the alkaloids while processing the plant material as per traditional method of fermentation. Additionally a high resolution CZE method was developed for the separation of several Sceletium alkaloids in relatively short analysis times. This analytical method was used successfully to fingerprint the alkaloids and quantify mesembrine in Sceletium and its products. Sceletium species grown under varying conditions at different locations, when analyzed, showed major differences in their composition of alkaloids and an enormous difference was found to exist between the various species with respect to the presence and content of alkaloids. Sceletium and its products marketed through health shops and the internet may thus have problems with respect to the quality and related therapeutic efficacy. The QC of Sceletium presents a formidable challenge as Sceletium plants and products contain a complex mixture of compounds. The work presented herein contributes to a growing body of scientific knowledge to improve the QC standards of herbal medicines and also to provide vital information regarding the selection of plant species and information on the specific alkaloidal constituents to the cultivators of Sceletium and the manufacturers of its products.
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  • Date Issued: 2007

Establishing the benefits of implementing an I.T. project management office in the Nelson Mandela Metropolitan area

  • Authors: Martin, Michael Ronald Charles
  • Date: 2007
  • Subjects: Project management -- South Africa -- Port Elizabeth -- Computer network resources , Information technology -- South Africa -- Port Elizabeth -- Management
  • Language: English
  • Type: Thesis , Masters , MTech
  • Identifier: vital:9266 , http://hdl.handle.net/10948/558 , Project management -- South Africa -- Port Elizabeth -- Computer network resources , Information technology -- South Africa -- Port Elizabeth -- Management
  • Description: The well-known concept of a Project Manager managing an I.T. project in relative isolation is no longer a viable option for organisations that are running numerous projects simultaneously. Due to the enormous costs and risks involved in many of these projects, there needs to be a means to ensure success. This has led to the establishment of the concept of a Project Management Office (PMO). An autonomous business unit that is responsible for managing all projects within an organisation. The need for a Project Management Office (PMO) to effectively manage multiple projects is becoming more and more accepted worldwide. The benefits of a PMO are well documented, but whether these benefits will apply to organisations within the NMM area needed to be investigated. A detailed analysis of the benefits of Project Management and in particular a PMO, have been investigated by means of a literature study. An investigation into the effectiveness of PMO’s in South Africa in general, was conducted by means of a survey targeted at a group of I.T. Project Managers located in all the major centres. A further survey was conducted among local I.T. managers to determine their current level of success and their expectations for the future. When reviewing the expectations of local I.T. management against the performance of Project Managers that are currently operating within PMOs, it is clear that organisations within the NMM area are in need of PMO’s and would certainly benefit from their establishment.
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  • Date Issued: 2007

The effect of sulfide on -glucosidases: implications for starch degradation in anaerobic bioreactors

  • Authors: Wutor, V C , Togo, C A
  • Date: 2007
  • Language: English
  • Type: Article
  • Identifier: vital:6463 , http://hdl.handle.net/10962/d1005792 , dx.doi.org/10.1016/j.chemosphere.2006.03.011
  • Description: Membrane associated α-glucosidase activity was investigated in a methanogenic bioreactor (MR) and a biosulfidogenic bioreactor (SR). Temperature and pH optima studies showed temperature optima of 50 °C and pH optima of 8.0 for the α-glucosidases from both the MR and SR. Sulfide (at a concentration of 150 mg l[superscript (−1)]) resulted in the complete loss of all α-glucosidase activity in both the MR and SR. β-Glucosidase activities in our bioreactors were previously shown to be stimulated in the presence of sulfide. α-Glucosidases, in contrast, are inhibited by sulfide. This differential effect of sulfide on α-glucosidase and β-glucosidase activities is highlighted and is of crucial consequence to the respective degradation and utilization of starch and cellulose substrates in natural anaerobic environments and anaerobic bioreactors specifically designed for the accelerated digestion of wastewater sludge under biosulfidogenic conditions.
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  • Date Issued: 2007

Strategies for managing work related stress

  • Authors: Müller, Elsie Franscina
  • Date: 2007
  • Subjects: Stress management , Job stress , Work -- Psychological aspects
  • Language: English
  • Type: Thesis , Masters , MBA
  • Identifier: vital:8577 , http://hdl.handle.net/10948/742 , Stress management , Job stress , Work -- Psychological aspects
  • Description: The objective of this study was to identify the strategies (primary, secondary and tertiary) that can be employed to manage work related stress. A questionnaire, was designed based on the strategies found in a literature study on the topic and used to gather inputs from academic head of department and lecturers. The questionnaire was delivered by hand to 18 potential respondents. All 16 questionnaires returned could be used. These were processed and analysed using Microsoft Excel spreadsheets. In general support was found for primary stress management strategies pertaining to work schedule, work load and work pace, job content, career development, the home-work relationship and work environment. Lifestyle management in terms of physical activities and a healthy diet were regarded as the preferred secondary stress management strategies. The strategies related to lifestyle management which were identified from the literature study were physical activities, healthy diet, relaxation techniques such as meditation and yoga. Support was found for tertiary stress management strategies but most of the respondents were not sure if their organisation offered any wellness, employee assistance or stress management programmes. Wellness programmes were indicated as a strategy that will have the most impact on reducing work related stress and employee assistance programmes (EAPs) ranked there after. Overall respondents indicated that they did not perceive their work as very stressful.
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  • Date Issued: 2007

An investigation of statistical methodologies for evaluating natural herbicides for the control of yellow nutsedge (Cyperus esculentus)

  • Authors: Asquith, Ilse Bernadette
  • Date: 2007
  • Subjects: Chemometrics , Weeds
  • Language: English
  • Type: Thesis , Doctoral , DTech (Chemistry)
  • Identifier: vital:10376 , Chemometrics , Weeds
  • Description: The present study was undertaken with the view to evaluate methodologies based on traditional Scheffé experimental designs that study mixtures as a tool for discovery research particularly when seeking new and or improved uses of existing mixtures. For the purpose of this study, the topic of controlling the problematic weed known as Yellow Nutsedge (Cyperus esculentus L. var. esculentus) or “Geel Uintjie”, was selected on a rather ad hoc basis. Yellow Nutsedge is a troublesome perennial weed found in most agricultural countries in the world. Herbicidal control is often difficult because of the weeds’ ability to propagate via tubers, which can remain dormant for a number of years and are also resistant to most synthetic herbicide controls. As a first step the study involved the selection of a group of chemical compounds that would be used in suppressing the germination of Yellow Nutsedge tubers. Treatment with various combinations of these chemical compounds as determined by statistical experimental designs was carried out. A review of the literature, particularly literature concerned with the study of the phenomenon of allelopathy, suggested that various phenolic-D-glucopyranosides could show promise in the suppressing the germination of Yellow Nutsedge tubers. This led to the selection of this group of compounds as the target group of “active” substances for the study. Since the group of phenolic-D-glucopyranosides is quite large, and in order to keep the study to a reasonable size, only four phenolic-D-glucopyranosides were selected namely: 4-nitrophenyl-D-glucopyranoside, 4-chlorophenyl--Dglucopyranoside, arbutin and salicin. This selection was based firstly based on a particular phenolic-D-glucopyranoside being a suspected allelochemical, and secondly the ease of technical synthesis using a catalytic process. In addition to the four selected phenolic-D-glucopyranosides, their aglycones (4,nitrophenol, 4,chlorophenol, hydroquinone and salicyl alcohol) were also included as potential “active” substances in order to discern any potential activity between the phenolic-D-glucopyranosides and the aglycones. iii The selected “active substances” were combined in various combinations according to various mixture designs in such a manner that the sum of the proportions of the various actives in any one mixture was always equal to 1. The mixtures of actives were then used in various germination experiments and three experimental responses were measured namely the germination, average dry mass and length of longest shoot. From the results of these germination studies the canonical form of the polynomial equation describing the variation in each of the three germination responses was calculated and evaluated statistically. These equations were then used to estimate the presence of, and the magnitude of synergism between the various active substances. The results from these screening experiments and their detailed statistical analysis indicated that the response surface model for the germination response contains three synergistic blends (4-nitrophenyl--D-glucopyranoside + arbutin; 4-nitrophenyl--Dglucopyranoside + hydroquinone; and 4-chlorophenyl--D-glucopyranoside + salicin) and one antagonistic blend (4-nitrophenyl--D-glucopyranoside + 4- chlorophenol--D-glucopyranoside). The response surface model for the average dry mass response contains two synergistic blends (4-nitrophenyl--Dglucopyranoside + hydroquinone; and 4-chlorophenol--D-glucopyranoside + salicin) and the same antagonistic blend as for germination response. For both germination and average dry mass responses, the most synergistic blend was found to be the combination of 4-chlorophenyl--D-glucopyranoside and salicin. Two additional tests were conducted and both confirmed the results obtained from the screening designs. These tests involved the identification of the two components responsible for the synergistic activity that resulted in the suppression of the germination of the tubers and growth of the seedlings. The experimental response measuring the longest shoot proved to be erroneous and was excluded from the statistical analysis. In summary, this study has clearly shown that statistically designed experiments based on mixture designs can be used as a powerful tool in identifying and quantifying synergistic (or antagonistic) effects of chemicals on the germination ability of plant seeds.
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  • Date Issued: 2007

An investigation into the popularity of the Zimbabwean tabloid newspaper, uMthunywa: a reception study of Bulawayo readers

  • Authors: Mabweazara, Hayes Mawindi
  • Date: 2007
  • Subjects: uMthunywa (Zimbabwe) Tabloid newspapers -- Zimbabwe Journalism -- Zimbabwe Newspapers -- Marketing -- Zimbabwe Mass media -- Social aspects -- Zimbabwe
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:3454 , http://hdl.handle.net/10962/d1002908
  • Description: The development of the tabloid press has stirred heated debate among media scholars. Critics have argued against the relevance of tabloids in society, often framing them as the ‘journalistic other’ deserving no place in ‘serious’ journalism. Much of this criticism, however, has not been based on a close interrogation of the phenomenon, or an examination of the reasons for their popularity amongst readers. It is against this background that this study investigates the reasons behind the popularity of the Zimbabwean state-controlled tabloid newspaper uMthunywa, among its Bulawayo readers. In particular, it explores the meanings obtained from the content of the paper and the relevance of this content to the readers’ everyday lives. In undertaking this investigation, the study draws primarily on qualitative research methods, particularly qualitative content analysis and in-depth interviews (both group and individual). As the study demonstrates, these methods uncover the complex manner in which Bulawayo readers are attracted to uMthunywa and how they appropriate its textual meanings to their lived realities. The study establishes that despite uMthunywa being state-controlled, it offers space through which the conventional ways of presenting reality are challenged, and the importance of the newspaper being written in isiNdebele. As the study indicates, the popularity of the newspaper is largely dependent on its excessive formulaic and sensational stories, which cover issues experienced by its readers in their lived circumstances. The study thus argues that the newspaper constitutes an alternative mediated public sphere that finds space in the deeper social conditions that have alienated the people of Bulawayo from the macropolitical life of the nation and the ‘power bloc’.
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  • Date Issued: 2007

A critical analysis of performance management within the manufacturing division at Continental Tyre South Africa

  • Authors: Dowling, Jurgen
  • Date: 2007
  • Subjects: Performance -- Management , Continental Tyre South Africa (Firm)
  • Language: English
  • Type: Thesis , Masters , MBA
  • Identifier: vital:8556 , http://hdl.handle.net/10948/497 , Performance -- Management , Continental Tyre South Africa (Firm)
  • Description: Many companies have performance management systems that incorporate financial and non-financial measurements. All organisations have financial and non-financial measures. However, many use their non-financial measures for local improvements at their front-line and customer-facing operations. Performance management is a shared process between managers and the individuals and teams they manage. It is based on the agreement of objectives, knowledge, skill and competence requirements and work and development plans. The Balanced Scorecard includes financial measures that reflect the results of actions already taken, complementing the financial measures with operational measures on customer satisfaction, internal processes, and the organisation’s innovative and improvement activities. The Balanced Scorecard combines both quantitative and qualitative measures, acknowledge the expectations of different stakeholders and relate an assessment of performance to choice of strategy. The objective of this study was to assess current performance management that is applied within the manufacturing division at Continental Tyre South Africa. To achieve this objective, a comprehensive literature study was performed on performance management and The Balanced Scorecard. A questionnaire was designed based on the guidelines in the literature study in order to establish the extent to which Continental Tyre South Africa manages performance. The researcher used the random sampling method of selection and distributed the questionnaire to 120 potential respondents via electronic mail and physically. Seventy seven completed questionnaires were returned and these were processed and analysed using Microsoft Office Excel 2003, iii running on the Windows XP suite of computer packages. The opinions of the various respondents were compared with the guidelines provided in the literature survey in order to identify shortcomings of performance management and the achievement of individual and departmental objectives within the manufacturing division at Continental Tyre South Africa. The following main recommendations were made: Continental Tyre South Africa should continue with the sharing of its strategic objectives with management and staff, and must ensure that these objectives are also shared all the way down to the shop floor; It is imperative that management and staff mutually agree on performance objectives for the individuals; Senior management must measure management and staff on how well they performance manage their direct reports and develop people where performance short-comings exist; It is imperative that management and staff undergo performance management training; Management must ensure that there current performance management system incorporates a method to distinguish between top and poor performers; and, It is advisable that senior management consider a mechanism that rewards top performers.
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  • Date Issued: 2007

Investigating the implementation of continuous assessment at the lower primary phase in a Namibian school

  • Authors: Hamukonda, Paulina
  • Date: 2007
  • Subjects: Education, Elementary -- Namibia Educational tests and measurements -- Namibia
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:1592 , http://hdl.handle.net/10962/d1003474
  • Description: Many Namibian teachers experience difficulties in actualising the principles of learner-centred education, one of which being continuous assessment. Continuous assessment serves important formative purposes. That is, it can inform education stakeholders and help improve learners’ progress in the teaching and learning environment. Although a great deal is known about continuous assessment in general, not much is yet known about how Namibian lower primary teachers actually understand and implement continuous assessment in the classroom. This study investigates the assessment practices of three Grade Three teachers in a school in Oshana Region of Namibia. The study found that although the teachers who participated in the investigation have a reasonably sound knowledge of continuous assessment in theory, they lack implementation skills. They were unable to effectively transfer what they know to what they actually do. This study found that as much as training of teachers is important, the ongoing professional development of teachers is more appropriate for enhancing a complex understanding of issues related to learner-centred education that will help them to manage continuous assessment more effectively.
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  • Date Issued: 2007

The coping resources and subjective well-being of dual-career Hindu mothers

  • Authors: Prag, Hanita T
  • Date: 2007
  • Subjects: Women -- India , Women -- Employment -- India , Hindu women -- Social life and customs
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:9932 , http://hdl.handle.net/10948/593 , Women -- India , Women -- Employment -- India , Hindu women -- Social life and customs
  • Description: With the increasing number of women entering the labour force internationally, the role of women is changing. Consequently, researchers are pressed to investigate how females of all cultures balance their work and family responsibilities. Amongst Hindu couples, this issue can either be a source of tension or positive support. An overview of literature indicates that the psychological aspects of dual-career Hindu women have received little attention in South Africa. The current study aimed to explore and describe coping resources and the subjective well-being of full-time employed Hindu mothers. The study took the form of a non-experimental exploratory-descriptive design. Participants were selected through nonprobability convenience sampling. The sample of the study consisted of sixty full-time employed Hindu mothers between the ages of 25 and 45 years of age who had at least one dependent primary school child aged between 7 to 12 years. Various questionnaires were used to collect data for this study. These included a Biographical Questionnaire, The Coping Resources Inventory (CRI), The Satisfaction with Life Scale (SWLS), and The Affectometer 2 (AFM2). Data was analysed by means of descriptive statistics. Cronbach’s coefficient alphas were utilised to calculate the reliability of the scores of each questionnaire. A multivariate technique was used to determine the amount of clusters formed. A non-hierarchical partitioning technique known as K-means cluster analysis was utilised in this study. An analysis of variance (ANOVA) was utilised in order to compare the mean scores of the various clusters. A post-hoc analysis using the Scheffé test was computed to test for significant differences. Cohen’s d statistics was subsequently used to determine the practical significance of the differences found between the cluster means on each of the measures. The cluster analysis indicated three clusters that differed significantly from one another on all three measures. The results of the CRI indicated that the participants used cognitive and spiritual resources to assist them to cope with the transition from traditional to modern contemporary roles. It was also found that the participants with low coping resources had inferior subjective well-being compared to those who had average and high CRI scores. The findings indicated that the participants were generally satisfied with their lives and experienced high levels of positive affect and low levels of negative affect. However, as a group there was a trend for the participants to have experienced slightly lower levels of global happiness or slightly negative affect. The results of this study broadens the knowledge base of positive psychology with respect to the diverse cultures and gender roles within South Africa. Overall, this study highlighted the value and the need for South African research on the coping resources and subjective well-being of dual-career Hindu mothers.
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  • Date Issued: 2007

Health, human rights, and the conduct of clinical research within oppressed populations

  • Authors: Mills, E J , Singh, S
  • Date: 2007
  • Language: English
  • Type: Article
  • Identifier: vital:6411 , http://hdl.handle.net/10962/d1006504 , http://dx.doi.org/10.1186/1744-8603-3-10
  • Description: Background Clinical trials evaluating interventions for infectious diseases require enrolling participants that are vulnerable to infection. As clinical trials are conducted in increasingly vulnerable populations, issues of protection of these populations become challenging. In settings where populations are forseeably oppressed, the conduct of research requires considerations that go beyond common ethical concerns and into issues of international human rights law. Discussion Using examples of HIV prevention trials in Thailand, hepatitis-E prevention trials in Nepal and malaria therapeutic trials in Burma (Myanmar), we address the inadequacies of current ethical guidelines when conducting research within oppressed populations. We review existing legislature in the United States and United Kingdom that may be used against foreign investigators if trial hardships exist. We conclude by making considerations for research conducted within oppressed populations.
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  • Date Issued: 2007

Localisation of Theiler's Murine Encephalomyelitis virus non-structural proteins 2B, 2C, 2BC and 3A in BHK-21 cells, and the effect of amino acid substitutions in 2C on localisation and virus replication

  • Authors: Murray, Lindsay
  • Date: 2007
  • Subjects: Encephalomyelitis -- Genetic aspects , Amino acid sequence , Picornaviruses , Viruses -- Reproduction
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4090 , http://hdl.handle.net/10962/d1007722 , Encephalomyelitis -- Genetic aspects , Amino acid sequence , Picornaviruses , Viruses -- Reproduction
  • Description: The picornavirus family includes significant human and animal viruses such as poliovirus (PV), human rhinovirus (HRV) and foot-and-mouth-disease virus (FMDV). Current disease treatment and control strategies are limited by an incomplete understanding of the interactions between the non-structural, replicative picornavirus proteins and host cell components. To investigate these interactions, Theiler's murine encephalomyelitis virus (TMEV) 2B, 2C, 2BC and 3A proteins were transiently expressed in BHK-21 cells and detected by indirect immunostaining and laser-scanning or epifluorescence microscopy. The signal of the 2B protein overlapped with that of the ER marker protein, ERp60, as well as that of the peripheral Golgi marker protein, β-COP. The 2C protein overlapped with ERp60 in a faint reticular stain, and localised to large punctate structures that partially overlapped with β-COP at higher levels of expression. The 2BC protein located to large perinuclear structures that overlapped exclusively with β-COP. The TMEV 3A protein signal overlapped with both ERp60 and β-COP stains, in addition in cells expressing the 3A protein the ER appeared swollen and bulbous while the Golgi was dispersed in some cells. 2C and 2BC proteins with C-terminal deletions localised in the same manner as the wild type proteins indicating that the localisation signals that determine subcellular localisation of the proteins are within the N-terminal 60 amino acids of the 2C protein. The significance of the high degree of conservation of the N-terminal domain of the 2C protein throughout the Picornaviridae was investigated through the introduction of amino acid substitution mutations at highly conserved residues in the N-terminal domain of 2C into the viral cDNA. Upon transfection of the viral RNA into BHK-21 cells, it was observed that substitution of amino acid residues 8, 18 and 29 abolished the ability of TMEV to induce cytopathic effect (CPE), while substitution of residues 4, 14 and 23 only attenuated the ability of TMEV to induce CPE. To determine whether amino acid substitution mutations would affect the localisation of the 2C protein, 2C proteins with substitution mutations at amino acids 4, 8, 14, 18, 23 and 29 were transiently expressed in BHK-21 cells and detected by indirect imrnunostaining and examination by laser-scanning confocal and epifluorescence microscopy. The 2C mutant 4, 8 and 29 proteins showed slightly altered localisation patterns compared to the wild type protein with a significant portion of the proteins localising in a perinuclear stain suggesting possible localisation to the nuclear envelop. The 2C mutant 14 and 18 proteins localised to a diffuse pattern in BHK-21 cells while the 2C mutant 23 protein located to small punctate structures that partially overlapped with the ERp60 stain but were completely separate from the β-COP stain. Finally, a hydrophilic, antigenic region of the 2C protein was expressed in frame with an N-terminal GST tag and was successfully purified on a pilot-scale and detected by Western analysis. This 2C178 peptide will be used to generate antibodies against the 2C and 2BC proteins for use in future studies. This study has furthered our knowledge of the localisation of the picornavirus 2B, 2C, 2BC and 3A proteins in host cells and identified a possible link between this localisation and an ability of TMEV to replicate in BHK-21 cells.
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  • Date Issued: 2007
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