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Isolation, propagation and rapid molecular detection of the Kalahari truffle, a mycorrhizal fungus occurring in South Africa

  • Authors: Adeleke, Rasheed Adegbola
  • Date: 2007 , 2013-04-03
  • Subjects: Truffles -- Kalahari Desert , Fungi -- Identification , Mycorrhizal fungi -- South Africa , Edible fungi -- South Africa , Mushroom culture -- South Africa , Fungi -- Cultures and culture media -- South Africa , Truffles -- South Africa , Truffles -- Lifecycles , Mycorrhizal fungi -- Lifecycles
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:3889 , http://hdl.handle.net/10962/d1002951 , Truffles -- Kalahari Desert , Fungi -- Identification , Mycorrhizal fungi -- South Africa , Edible fungi -- South Africa , Mushroom culture -- South Africa , Fungi -- Cultures and culture media -- South Africa , Truffles -- South Africa , Truffles -- Lifecycles , Mycorrhizal fungi -- Lifecycles
  • Description: Terfezia pfeilii is an edible mycorrhizal fungus that thrives in the Kalahari Desert of southern Africa. It is best known by desert dwellers for its flavour and as a source of nutrition. Although the genus Terfezia is generally regarded as being an ectomycorrhizal mycobiont, the exact mycorrhizal type formed by T. pfeilli and its' associated host plants remains uncertain. Discovery of the host plants for T. pfeilii would first be required in order to further investigate the life cycle and cultivation of this truffle. This study focussed on the isolation of mycelia from the ascocarp, optimising the growth conditions of the mycelial cultures, rapid molecular identification of T. pfeilii, investigation of potential helper bacteria and mycorrhizal synthesis experiments. T. pfeilii ascocarps were harvested from the Spitskop Nature Reserve in Upington, South Africa. Ascocarps were successfully identified using both morphological and molecular methods. Despite the delayed growth mostly caused by contaminating microorganisms, the isolation of T. pfeilii mycelia culture was successful. Molecular techniques were used to confirm the identity of the pure culture. Further studies were conducted on ways to improve the growth conditions of the mycelial culture on Fontana medium. An optimum temperature of 32°C, the addition of Bovine Serum Albumin as a nitrogen source and a pH of 7.5 significantly improved the growth of T. pfeilii in vitro. A rapid PeR-based molecular method was developed to speed up the identification of T. pfeilii. Specific primers that can exclusively amplify the ITS region of T. pfeilii were designed and used to identify both the ascocarps and the mycelial culture. The specificity of these primers was confirmed by their inability to amplify DNA from the isolates of contamining fungi obtained during the isolation process. Molecular comparison was made to confirm the reclassification of South African samples of T. pfeilii as Kalaharituber pfeilii as proposed by Ferdman et al.,(2005). However, in this study, the name T. pfeilii has been retained. A total of 17 bacterial isolates were obtained from the fruiting bodies of T. pfeaii and these were tested for stimulation of mycelial growth in vitro, indole production and phosphate solubilising capabilities. Bacterial isolates that showed potential to be Mycorrhization Helper Bacteria (MHB) were identified as Paenibacillus sp., Bacillus sp. and Rhizobium tropici. Selected plant seedlings were inoculated with T. pfeilii cultures or ascocarp slurry in order to re-establish the mycorrhizal association. After 8 months, light microscopy observations revealed an endomycorrhizal type association between Cynodon dactylon and T. pfeilii. This was confirmed with molecular analysis using specific T. pfeilii ITS primers. After 15 months, molecular methods confirmed Acacia erioloba as another host plant. These results have provided essential information paving the way for further investigation into the life cycle and biology of the Kalahari truffle. , KMBT_363 , Adobe Acrobat 9.53 Paper Capture Plug-in
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  • Date Issued: 2007

Voltammetric characterisation of the self-assembled monolayers (SAMs) of benzyl-and dodecyl-mercapto tetra substituted metallophthalocyanines complexes

  • Authors: Agboola, Bolade , Westbroek, Philippe , Ozoemena, Kenneth I , Nyokong, Tebello
  • Date: 2007
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/281414 , vital:55723 , xlink:href="https://doi.org/10.1016/j.elecom.2006.08.047"
  • Description: Voltammetric characterisations of cobalt, iron, manganese, nickel and zinc phthalocyanine complexes tetra substituted with benzyl- and dodecyl-mercapto ring substituents and immobilisation on gold electrodes via the self-assembling technique are presented. The self-assembled films are stable and showed blocking characteristics towards the following Faradaic processes; gold surface oxidation, under potential deposition of copper and solution redox chemistry of [Fe(H2O)6 3+ ]/[Fe(H2O)6 2+ ]. The solution chemistry of [Fe(CN)6]−3/[Fe(CN)6]−4 redox process was used to study the orientation of the CoPcs-SAMs and this revealed a possible deviation from flat orientation of the complexes on the gold electrodes when the SAM formation times were greater than 24 h. For SAM formation time at 24 and 48 h, CoTDMPc-SAM showed more inhibition of the [Fe(CN)6]−3/[Fe(CN)6]−4 redox process than the CoTBMPc-SAM counterpart, indicating more blocking characteristics of the dodecylmercapto ring substituents compared to the benzylmercapto counterpart. To avoid SAM desorption, the potential application should be limited to −0.2 to +0.8 V vs. Ag∣AgCl (NaCl, sat’d) in acidic and neutral pH.
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  • Date Issued: 2007

Electrocatalytic oxidation of chlorophenols by electropolymerised nickel (II) tetrakis benzylmercapto and dodecylmercapto metallophthalocyanines complexes on gold electrodes

  • Authors: Agboola, Bolade , Nyokong, Tebello
  • Date: 2007
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/281247 , vital:55705 , xlink:href="https://doi.org/10.1016/j.electacta.2007.02.017"
  • Description: This work reports on the use of nickel(II) tetrakis benzylmercapto (NiTBMPc) and dodecylmercapto (NiTDMPc) metallophthalocyanine complexes films on gold electrodes for the electrochemical oxidation of 4-chlorophenol (4-CP) and 2,4,5-trichlorophenol (TCP). Both NiTBMPc and NiTDMPc complexes were successfully deposited on gold electrodes by electropolymerisation. The films were electro-transformed in aqueous 0.1 M NaOH solution to the ‘O–Ni–O oxo’ bridged form. For both complexes, films with different thickness were prepared and characterised by electrochemical impedance and UV–vis (on indium tin oxide) spectroscopies and the results showed typical behaviour for modified electrodes with increasing charge transfer resistance values (Rp) with polymer thickness. The poly-Ni(OH)NiPcs showed better catalytic activity than their poly-NiPcs counterparts.
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  • Date Issued: 2007

Comparative electrooxidation of nitrite by electrodeposited Co (II), Fe (II) and Mn (III) tetrakis (benzylmercapto) and tetrakis (dodecylmercapto) phthalocyanines on gold electrodes

  • Authors: Agboola, Bolade , Nyokong, Tebello
  • Date: 2007
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/281212 , vital:55702 , xlink:href="https://doi.org/10.1016/j.aca.2007.01.031"
  • Description: This work reports on the electrooxidation of nitrite using Co(II), Fe(II) and Mn(III) tetrakis (benzylmercapto) and tetrakis (dodecylmercapto) phthalocyanines electrodeposited onto a gold electrode. Good catalytic activity (in terms of lowering overpotential) was obtained for these molecules when compared to previously reported MPc catalysts. The catalytic current was found to vary linearly with nitrite concentration in the range employed in this work (0.1–1 mM) and high sensitivities ranging from 6.9 to 9.9 μA mM−1 were observed for all the modified electrodes.
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  • Date Issued: 2007

Comparative electrooxidation of sulphite by self-assembled monolayers (SAMs) of Co (II), Fe (II), Ni (II) and Mn (III) tetrakis benzylmercapto and dodecylmercapto metallophthalocyanines complexes on gold electrodes

  • Authors: Agboola, Bolade , Nyokong, Tebello
  • Date: 2007
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/281223 , vital:55703 , xlink:href="https://doi.org/10.1016/j.talanta.2006.11.042"
  • Description: This work reports on the use of Co(II), Fe(II), Mn(III) and Ni(II) tetrakis benzylmercapto and dodecylmercapto phthalocyanine complexes for gold electrode modification for electrooxidation of sulphite ions. The complexes were successfully used to modify gold electrodes by self-assembled monolayer (SAM) technique. The self-assembled films are stable and showed blocking characteristics towards the following Faradaic processes; gold surface oxidation, underpotential deposition (UPD) of copper and solution redox chemistry of [Fe(H2O)63+]/[Fe(H2O)62+]. All the modified electrodes showed improved catalytic activities than the unmodified gold electrode towards sulphite ion electrooxidation with all the modified electrodes exhibiting high resistance to electrode surface passivation. Better catalytic performance were obtained for the CoPcs, FePcs and MnPcs which have metal based redox processes within the range of the sulphite electrooxidation peak, while the NiPcs which did not show metal based redox reaction performed less. The catalytic current was found to be linear with sulphite ion concentration in the concentration range employed in this work (0.1–1 mM) and sensitivities ranging from 1.68 to 2.96 μA/mM were observed for all the modified electrodes. Mechanisms of the catalytic oxidation of sulphite ions are proposed.
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  • Date Issued: 2007

Synthesis and electrochemical properties of benzyl-mercapto and dodecyl-mercapto tetrasubstituted manganese phthalocyanine complexes

  • Authors: Agboola, Bolade , Ozoemena, Kenneth I , Westbroek, Philippe , Nyokong, Tebello
  • Date: 2007
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/281321 , vital:55713 , xlink:href="https://doi.org/10.1016/j.electacta.2006.09.002"
  • Description: Manganese tetrakis (benzyl-mercapto) phthalocyanine (MnTBMPc) and manganese tetrakis (dodecyl-mercapto) phthalocyanine (MnTDMPc) complexes were synthesized and their spectral and electrochemical properties are reported. Cyclic voltammetric data showed three reversible to quasi-reversible and two irreversible redox processes for both complexes. Ring substituents influenced the positions of both oxidation and reduction redox couples. Spectroelectrochemistry confirmed the first two reductions to be due to MnIIIPc2−/MnIIPc2− and MnIIPc3−/MnIIPc2− processes. The first example of a formation of self-assembled monolayers (SAMs) using thiol substituted MnPc complexes is presented, the SAMs were found to show blocking characteristics towards some faradaic reactions.
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  • Date Issued: 2007

Catalytic activities of metallophthalocyanines towards detection and transformation of pollutants

  • Authors: Agboola, Bolade Oyeyinka
  • Date: 2007
  • Subjects: Phthalocyanines Electrochemistry Pollutants -- Biodegradation Pollutants -- Measurement
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:4427 , http://hdl.handle.net/10962/d1006922
  • Description: Syntheses, spectral, electrochemical and spectroelectrochemical studies of new thiol-derivatised MPc complexes were satisfactorily carried out. For the first time, spectroelectrochemistry gave evidence for the formation of Ni²⁺/Ni⁺ process in a NiPc complex. Significant insights as to the nature of Fe⁺Pc and Ni⁺Pc spectra were obtained. Transformations of chlorophenols using chemical and photochemical methods are presented. For cobalt tetrasulphophthalocyanine catalysed oxidation of chlorophenols using hydrogen peroxide as the oxidant, types of oxidation products formed depended on the solvent conditions. Photolysis of aqueous solutions of chlorophenols in the presence of immobilised non-transition metal phthalocyanine photosensitisers onto Amerlite® was carried out. For the first time, MPcS[subscript mix] complexes were immobilised on Amberlite® for use in heterogeneous photocatalysis. Photolysis of the chlorophenols resulted mainly in the formation of chlorobenzoquinone derivatives. The generation of singlet oxygen (¹O₂) by these immobilised MPc photosensitisers was found to play a major role in their photoactivities. Modifications of gold electrodes with the newly synthesised thiol-derivatised MPc complexes via electropolymerisation and SAM techniques are presented. Cyclic voltammetry, impedance spectroscopy (NiPcs only) and spectroelectrochemical techniques (NiPcs only) confirmed that the complexes formed films on gold electrodes. Stable and well packed SAM films as evidenced by the voltammetric characterisation were obtained. For the first time, optimisation of the time for SAM formation based on CV technique was studied. First example of a formation of MnPc-SAM was achieved. Catalytic activities of the NiPc towards chlorophenol depended on the nature of the NiPc in the polymer films and also anti-fouling ability of the films depended on polymer film thickness. The FeTBMPc polymer modified gold electrode showed the best catalytic activity in terms of peak potential, E[subscript p] when compared to reported work in literature for nitrate electrooxidation. Cyclic voltammetry and spectroscopy studies showed that the CoPcs, FePcs and NiPcs catalysed nitrite oxidation involve 2 electrons in total while that of McPcs involve 1 electron. Better catalytic performance towards sulphite electrooxidation were obtained for the CoPcs, FePcs and MnPcs which have metal based redox processes within the range of the sulphite electrooxidation peak while the NiPcs which did not show metal based oxidation reaction performed less.
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  • Date Issued: 2007

The perceived economic impact of the city of Johannesburg's storm water attenuation policy on private property developers

  • Authors: Aldous, Michael Geoffrey
  • Date: 2007
  • Subjects: Runoff -- South Africa -- Johannesburg , Real estate development -- South Africa -- Johannesburg
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:9668 , http://hdl.handle.net/10948/765 , Runoff -- South Africa -- Johannesburg , Real estate development -- South Africa -- Johannesburg
  • Description: Stormwater attenuation policy has, over recent years, become a highly contentious issue for the property development community. Increased urbanisation, locally and internationally, has forced municipal authorities to reconsider the role of stormwater management in this evolving urban landscape. It is within this context that the legislative support and municipal policy for stormwater management in the City of Johannesburg has been explored, particularly in terms of the economic impact on property developers. The research aimed to explore the relationship between stormwater attenuation policy and the economic impact thereof on private property developers. Consideration was given to the cost, risk and time factors of legislative and policy requirements within the development process. Further consideration was given to the physical environment that has brought about current pressures. Based upon research of international issues highlighted in countries with well developed attenuation policy, a questionnaire was constructed to evaluate the response of local private property developers to selected issues as key sub-problems. The responses were tested against the developed set of hypotheses. The research indicated that developers had a generally poor level of knowledge with regard to the stormwater management policy of the City of Johannesburg, as well as the supporting legislative requirements of provincial and national policy documents. The results of the survey also indicated that developers were strongly opposed to the loss of developable area, but indicated a limited financial impact of the current stormwater attenuation policy. The risk inherent in incorporating an attenuation facility within a development was identified as being low with little perceived impact. Developers further indicated that the inclusion of attenuation facilities was seen as a significant contributing factor in the delay, approval and acceptance of new developments in which attenuation facilities were required, while maintenance costs were indicated to be of a low level of importance. Recommendations in response to the research findings included the establishment of detailed policy documentation and support for effective distribution channels in conjunction with industry and public focused information campaigns, improved municipal capacity and a greater level of technical support. A need for additional stormwater research and an increase in the capture of relevant data for GIS purposes was identified.
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  • Date Issued: 2007

Improving construction planning through 4D planning

  • Authors: Allen, Christopher James
  • Date: 2007
  • Subjects: Construction industry -- Management , Construction industry -- Computer-aided design
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:9698 , http://hdl.handle.net/10948/467 , http://hdl.handle.net/10948/d1011923 , Construction industry -- Management , Construction industry -- Computer-aided design
  • Description: Construction Planning will increasingly play a more critical role within the realm of the Built Environment. Existing practices used to plan and communicate the construction process to be undertaken are failing to deliver the desired results for construction companies and clients alike. At a time of unprecedented growth in the industry around the world, which is leading to a general skills shortage, especially in management positions, construction planners are increasingly being asked to deal with more responsibility. As with other industries, technological improvement in the tools at their disposal is one way to address the inadequacies of the present situation. Increasingly, three dimensional design packages are being used to generate construction information which can then be used for quantities calculations, automated manufacturing processes and construction simulation. The latter forms the basis for their use in the process of planning, through new technologies being developed as virtual construction tools or 4D planning, the addition of time to the 3D model environment, but using the elements within the model as the basis for the construction programme. The benefit of using the design information to form the basis of the programme is that the interface tasks and logistical activities, as well as location related constraints, can be identified and then communicated to all levels within the construction team through a time based visual image. The purpose of this study is therefore to establish a scientifically analysed alternative method for the creation, review and delivery of construction programmes. In order to achieve the research objectives, three methodologies have been employed. Firstly, the literature review in the fields of planning including existing methodologies and previous research of 4D related techniques has been analysed. An overview of the perceived weaknesses to current practises and proposed solution will be explored and best case scenarios outlined and further investigated. Secondly, the 51 Lime Street project provides an environment in which the proposed 4D planning techniques have been implemented and the benefits of the process can, through observation / participation methodology, be validated. Thirdly, through interview questionnaires, with Lime St contractors and management, and e-mail questionnaires to a broader sample stratum, data on the ability of the tools, the techniques employed on 51 Lime Street and similar projects have been collated and statistically analysed to validate the reliability and relevance for future implementation. The result of the research will provide management teams with a practical alternative to existing planning methodologies. Construction planners will have alternative technique that can further enhance their role within the project team whilst increasing their ability to communicate the team’s vision to a wider audience, making them and the project more efficient and effective in the process. It has been proposed that clients insist on the use of 3D from the commencement of the design process so that this information can be passed downstream through the construction process and onto facilities management. Planners need to be able to communicate their requirements better and the 4D planning models provide both a more inclusive way of planning alongside a better communications medium in the form of moving images. A picture tells a thousand words.
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  • Date Issued: 2007

Creating value through customer relationships in the services sector

  • Authors: Allie, Hisham
  • Date: 2007
  • Subjects: Customer services , Value added
  • Language: English
  • Type: Thesis , Masters , MBA
  • Identifier: vital:8740 , http://hdl.handle.net/10948/790 , Customer services , Value added
  • Description: Many academic studies in the past have focussed on how to create value for businesses in terms of adding profit to the bottom line through performance, and many argue that adding value for the client is also viewed as a profitable business strategy. This strategy translates as a win-win business relationship since long-term relationships ensure customer loyalty, customer retention and repeat business. In the services sector, it is difficult to quantify the worth or value that a particular service has since services are intangible products. The perception of value of such a service is known as “perceived value” since value recognition rests with the consumer who attempts to quantify the worth of that service. It is generally accepted in the services sector that establishing long-term, mutually beneficial, meaningful business relationships add value for the client and helps them to attach a value to the services that company provides. A company cannot establish such relationships without the help of its employees who represents the face of the organisation and implements the value adding strategy on the organisation’s behalf. Recent studies have begun to address this, examining value creation in business relationships in the context of the sale of tangible goods. The process of value creation for customers in services relationships remains underresearched. Perceived value explains why customers choose one particular service over another, why service companies gain competitive advantage by maintaining genuine longterm customer relationships, and why “the personal touch”, created through emotional attributes such as trust, caring and empathy, adds value from customers’ perspective. This dissertation presents a study of perceived value from the perspective of the customer within the context of the delivery of a credence product in a services relationship model. Using grounded theory methodology; following in-depth interviews with consumers of general insurance, a number of customer-value creation dimensions for businesses have been identified. Parallel interviews with members of staff from the supplier company add a further perspective. This research demonstrates how organisations or suppliers in the services industry can add value when delivering a credence product in a services relationship context. It is believed that an understanding of the value-adding dimensions can be implemented to create opportunities to build value for customers, with commensurate benefits for suppliers. Following analysis of the interviews held with each buyer, a total of six value dimensions are identified in the findings chapter. Each dimension is individually described, discussed, and illustrated with quotations from customers and supplier’s staff. Other issues relating to value arising from the interviews are examined in the discussion chapter. Three areas for further research are proposed in the conclusion.
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  • Date Issued: 2007

Implementation of learner-centred education by Grade 4 BETD in-service teachers in selected Namibia schools

  • Authors: Amakali, Amram
  • Date: 2007
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:1849 , http://hdl.handle.net/10962/d1004457
  • Description: Before independence Namibia's education system was predominantly teacher-centred. Soon after its independence Namibia embarked on education restructuring and transformation. A new education system, leamer-centred education, was introduced to cater for the needs of all Namibian learners. It was seen as an effective antidote to the stifling teacher-centred practices of the previous education system. A new programme, the Basic Education Teacher Diploma (BETD) was introduced to prepare teachers to teach in a leamer-centred approach. Research has, however, indicated that many Namibian teachers have a somewhat shallow or naIve understanding oflearner-centred education. This small-scale case study, conducted in Oshikoto region, focuses on two Grade 4 teachers. The study examined the two teachers ' perceptions and experiences oflearnercentred education and the teaching strategies they use to develop learners' understanding. The study uses a qualitative approach in its exploration of teachers ' lived experiences of becoming learner-centred. The data emerging from this case study identify a number of misconceptions and understandings of leamer-centred education and its implementation. The findings suggest that teachers ' misconceptions are caused by a lack of deep understanding about the epistemology and theory of learning which underpins Namibia's reform policies and principles.
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  • Date Issued: 2007

An investigation of interpersonal relationships between management and lecturers in a College of Education in Namibia

  • Authors: Amushigamo, Angelina Popyeni
  • Date: 2007
  • Subjects: Communication in education -- Namibia Teacher morale -- Namibia Employee motivation -- Namibia Teacher-administrator relationships -- Namibia College teachers -- Job satisfaction -- Namibia
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:1850 , http://hdl.handle.net/10962/d1004458
  • Description: Relationships are regarded as an important aspect of any organization's life. The purpose of this study was to investigate staff perceptions and experiences of interpersonal relationships between management and lecturers in a Namibian College of Education. I conducted a case study at the College where I teach. Two methods were used to collect data. Firstly, semi-structured interviews with two management members, two senior lecturers and two lecturers. Secondly, observation where practical aspects of interpersonal relationships in the College were observed. I used the interpretational data analysis technique to analyse my data. Themes and patterns were identified in the data, coded and sorted into categories. The study revealed staff unhappiness about the current situation in the College as far as communication is concerned. The College's hierarchical structure was described as top-down. As such, it does not allow for face to face communication. There is an absence of any social cohesion or sense of community. Relationships at a College level are characterized by personal conflict and difference. However, the study revealed a satisfaction with communication and relationships at a dl'partmentallevel. Five key features of interpersonal communication that are lacking in the College and that contribute to the unhealthy relationships in the College were identified. These are trust, respect, openness, feedback and the sharing of ideas and knowledge. Due to their absence, the College is divided into cliques. A strong desire for the establishment of interpersonal norms of openness, respect, honesty and trust was expressed. Participants expressed the need to establish an organization structure that allows for interaction with others in the College, flatter structures, teamwork and a collaborative cultu re. The study also emphasized participative democracy in building relationships. Participation in decision making is seen as satisfying the personal need to experience a sense of influence and achievement. There is evidence of a desire for distributed leadership where the College staff as a group of professionals lead the College collectively and collaboratively. There is a strong desire for a College where people are liked , valued, accepted by others and recognized for their efforts. Finally, Organization Development is recommended as an approach to enhance College staff relationships.
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  • Date Issued: 2007

Investigating grade 10 geography teachers' implementation of a learner-centred approach in selected Namibian schools

  • Authors: Angula, Adelheid
  • Date: 2007
  • Subjects: Geography -- Study and teaching (Secondary) -- Namibia Student-centered learning -- Namibia
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:1851 , http://hdl.handle.net/10962/d1004459
  • Description: Geography, more than other subjects in the curriculum, plays a central role in general education in equipping learners with skills and competencies needed for modern living and global citizenship. A learner-centred education in Namibia was adopted to provide more opportunities for learners to develop the required skills and competencies irrespective of their different cultural background. This small-scale case study investigated three Grade 10 geography teachers' understanding and implementation ofa learner-centred approach to gain insights into how leamer-centred education is being implemented in the context of Geography. The research design adopted a qualitative approach within an interpretative orientation. Data were collected through interviews, classroom observations and documentary analysis. The research was conducted at three selected schools in Oshikoto Region with three Grade 10 geography teachers The findings revealed, firstly, that teachers have a limited understanding of the key ideas ofLCE, such as, prior knowledge, role of questioning, and social interaction in learning; use of resources and the types of assessment activities which comply with the aims of LCE. Seconclly, the findings revealed that the policy documents, such as syllabuses, that are being used by the participants are not in line with the tenets ofLCE. Thirdly, teachers appeared to have limited subject knowledge, as revealed by their lack of understanding of how to translate the aims and assessment objectives into their daily lessons. The study therefore raises some possibilities for improving the implementation of LCE in the selected schools if the gaps as identified by this study are reduced.
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  • Date Issued: 2007

The trouble with culture : Plato's critique of poetry

  • Authors: Ansell, James D'Olier
  • Date: 2007 , 2013-07-25
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:2733 , http://hdl.handle.net/10962/d1004460
  • Description: In this thesis I argue that Plato's critique of poetry, taken in its proper context, is a serious and relevant critique of popular culture. In the first chapter I argue that the poetic reforms proposed in Books 2 and 3 and Book 10 of Republic stand at the front of a total reform of Greek culture. I argue for the consistency of Plato's whole argument and then I claim that if we get Plato's targets right, not fine art or literature, and focus on appropriate modern analogues then we can see why his critique is still important. If we share his claim that we are influenced by popular culture in important and often insidious ways and agree that culture can promote corrupt values, then we have accepted the core of Plato's challenge. If we find his solution distasteful, then the task is to come up with a democratic alternative. In the remaining two chapters I focus specifically on the challenge to the poets, putting the other reforms to the side. In the second chapter I consider a possible reply to the challenge focusing on the worth of the poetry that was expelled. I first look elsewhere in the Platonic oeuvre at the account of beauty in Symposium and Phaedrus but I argue that neither of them gives anything like aesthetic value that could be usefully applied to poetry. Next I look to some modern accounts of aesthetic value. I argue that while they might go some of the distance against Plato's challenge, they face a difficult task because it is not sufficient positing the value, an account is needed of their positive benefit. In the third chapter I turn to a more direct response to the challenge. Arguably Aristotle offers such a response in the Poetics, in terms of the notion of katharsis. I consider two interpretative candidates for katharsis. The first takes the benefit of poetry to be psychological - katharsis is a purgation of otherwise pathological emotions. I argue that this fails because it misunderstands precisely what Plato's concerns about poetry are, and, furthermore, this account could even be compatible with Plato's worries. The second interpretation takes the benefit of poetry to be ethical- katharsis is a type of ethical clarification which is beneficial in training our emotional responses. I claim that the clarification, and education, is worryingly conventionalist, and doesn't take seriously that Plato's target was popular culture and not great, educative literature. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
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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

Synthesis, Photophysical and Photochemical Properties of Poly (oxyethylene)‐Substituted Phthalocyaninato Oxotitanium (IV) Complexes

  • Authors: Atilla, Devrim , Durmus, Mahmut , Yılmaz, Özgür , Gürek, Ayşe Gül , Ahsen, Vefa , Nyokong, Tebello
  • Date: 2007
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/271263 , vital:54526 , xlink:href="https://doi.org/10.1002/ejic.200700057"
  • Description: The synthesis, photophysical and photochemical properties of tetra- and chlorotetrapoly(oxyethylene)-substituted oxotitanium(IV) phthalocyanines are reported for the first time. The new compounds were characterized by elemental analysis, IR, 1H and 13C NMR spectroscopy, electronic spectroscopy and mass spectra. These complexes showed monomeric behaviour in solution. General trends are described for photodegredation, singlet oxygen, triplet state and fluorescence quantum yields, and triplet and fluorescence lifetimes of these compounds in dimethyl sulfoxide (DMSO). Photophysical and photochemical properties of phthalocyanine complexes are very useful for PDT applications. The complexes showed high triplet quantum yields and triplet lifetimes in DMSO. The singlet oxygen quantum yields (ΦΔ), which give an indication of the potential of the complexes as photosensitizers in applications where singlet oxygen is required (Type II mechanism), were 0.72 and 0.78 for 3a and 5a, respectively. Thus, these complexes show potential as Type II photosensitizers. These complexes were also quenched by benzoquinone for fluorescence quenching studies.
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  • Date Issued: 2007

Synthesis and photodynamic potential of tetra-and octa-triethyleneoxysulfonyl substituted zinc phthalocyanines

  • Authors: Atilla, Devrim , Savdan, Nil , Durmus, Mahmut , Gürek, Ayşe Gül , Khan, Tania , Rück, Angelika , Walt, Heinrich , Nyokong, Tebello , Ahsen, Vefa
  • Date: 2007
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/281342 , vital:55715 , xlink:href="https://doi.org/10.1016/j.jphotochem.2006.08.022"
  • Description: Synthesis of the water soluble zinc phthalocyanines (3, 4) obtained from the phthalonitriles substituted with oligo(ethyleneoxy)thia groups are described. The new compounds have been characterized by elemental analysis, IR, 1H and 13C NMR spectroscopy, including HSQC, HMBC and COSY bidimensional correlation techniques, electronic spectroscopy and mass spectra. The aggregation behaviour of the phthalocyanine compounds (3, 4) was investigated using UV–vis spectroscopy in dimethylsulphoxide. Photochemical and photophysical measurements were conducted on oligo(ethyleneoxy)thia appended zinc phthalocyanines. General trends are described for quantum yields of photodegredation, fluorescence yields, triplet lifetimes and triplet quantum yields as well as singlet oxygen quantum yields of these compounds. The phototoxicity against cancer cells of the new compounds was investigated during several in vitro experiments. The dye-sensitized photooxidation of 1,3-diphenylisobenzofurane via 1O2 was studied in dimethylsulphoxide.
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  • Date Issued: 2007

The family maths programme: facilitators' ability to implement inquiry-based teaching and learning with learners and parents

  • Authors: Austin, Pamela Winifred
  • Date: 2007
  • Subjects: Mathematics -- Study and teaching -- South Africa , Inquiry-based learning -- South Africa
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:9483 , http://hdl.handle.net/10948/471 , Mathematics -- Study and teaching -- South Africa , Inquiry-based learning -- South Africa
  • Description: Despite the fact that the facilitation of inquiry learning is a core methodology in the General Education and Training (GET) band of the South African National Curriculum Statement, rote learning and memorization of algorithms remains common practice in many mathematics classrooms. The inquiry-based Family Maths professional development programme, offered by the Nelson Mandela Metropolitan University, attempts not only to support the transformative education practices targeted by the South African National Department of Education, but also to extend them beyond the school walls to the community at large. This study investigates the extent to which the Family Maths professional development programme develops facilitators’ ability to implement inquiry-based learning. It also seeks to explore which aspects of the programme are effective in developing an inquiry-based approach. The research undertaken is an empirical study of 39 facilitators and uses both qualitative and quantitative methods. The facilitators’ inquiry beliefs and ability to implement inquiry learning was measured by means of questionnaires, observation schedules and interviews. As the ‘teacher as facilitator of inquiry-based teaching and learning’ is a requirement of all South African teachers, the findings of this research should make a meaningful contribution to the field of mathematics teacher education in the South African context.
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  • Date Issued: 2007

Message to the New Zealand Old Rhodian Reunion

  • Authors: Badat, Saleem
  • Date: 2007
  • Subjects: Rhodes University
  • Language: English
  • Type: text
  • Identifier: vital:7647 , http://hdl.handle.net/10962/d1015775
  • Full Text:
  • Date Issued: 2007

Rhodes University Orientation Week : Welcome address of the vice-chancellor of Rhodes University, Dr Saleem Badat, 5 February 2007

  • Authors: Badat, Saleem
  • Date: 2007
  • Subjects: Rhodes University
  • Language: English
  • Type: text
  • Identifier: vital:7651 , http://hdl.handle.net/10962/d1015779
  • Full Text:
  • Date Issued: 2007
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