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An evaluation of small scale open cast mining of UG2 in the Bushveld complex

  • Authors: Mooney, David G
  • Date: 1997
  • Subjects: Platinum mines and mining -- South Africa , Strip mining -- South Africa
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4943 , http://hdl.handle.net/10962/d1005555 , Platinum mines and mining -- South Africa , Strip mining -- South Africa
  • Description: The current weak state of the platinum market, as well as the large inventory of platinum group metals held by Russia, necessitates that the South African platinum mining industry must carefully evaluate the benefits and disadvantage of small-scale mining of shallow, open castable ore resources. Until the late 1980's, these resources were ignored due to the metallurgical complexities of treating oxidized ore, as well as the mind set that existed within the South African mining industry which militated against open cast mining in the Bushveld. During the latter part of the 1980's and early 1990's, advances in the metallurgical treatment of oxidized ore, specifically the UG2, as well as operational problems, created the impetus to begin the exploitation of these resources. Small-scale open cast mining has become viable due to the development of suitable mining methods that facilitate mining practices acceptable to the Department of Mineral and Energy Affairs, in terms of environmental legislation. Metallurgical advances and growing experience, especially with respect to the UG2, enables reasonable platinum group metals recovery from oxidized ore. The problems experienced in doing this can, and are being overcome. With growing public awareness of environmental issues, particularly related to the mining industry, the requirement to ensure that the small-scale open cast mine site is well managed is paramount. A methodology for the evaluation is presented along with a case study of a small-scale UG2 open cast pit. Evidence is presented that shows that these small-scale open cast mining operations are extremely profitable and require minimal capital expenditure. However, caution is advised when evaluating Merensky Reef open cast operations because of the problems that they present.
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  • Date Issued: 1997

An examination of the factors underlying decision-making about selection and presentation of photographs of political conflict in South African newspapers

  • Authors: O'Dowd, Catherine Frances
  • Date: 1997
  • Subjects: Photojournalism , Photojournalism -- South Africa , Photojournalists -- South Africa , South Africa -- Politics and government -- 1989-1994
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:3478 , http://hdl.handle.net/10962/d1002933 , Photojournalism , Photojournalism -- South Africa , Photojournalists -- South Africa , South Africa -- Politics and government -- 1989-1994
  • Description: What newspaper readers see of an event is detennined by what photographs are seley ted and how they are presented. This thesis attempts to deconstruct the decision-making process around selection and presentation of photographs, with the aim of detennining what factors are taken into account in that process. It is based on the hypothesis that there must be a number of factors involved in decisions about news photographs, although these factors may not necessarily be consciously acknowledged in the decision-making process. The study involves a comparison of how five case studies of incidents of political violence, which occurred between 1990 and 1994 in South Africa, were used'in lrinewspapers. The focus on images of political violence is based on the assumption that politically and visually controversial images will give rise to situations in which gatekeepers will be caned upon to question their decisions. The research is based on qualitative research interviews with the decision-makers involved in the case studies. The analysis of the decision-making procedures is based on the theory of gatekeeping. The interviews are analysed in terms of Lewin's theory offqrces, which suggests that, depending on the context, some factors will manifest themselves as positive forces working in favour of the photograph being selected or well presented, while others will take the form of negative forces. The analysis sets out to determine what factors were taken into account in the decision::making process, what detennined their relative degrees of importance and how those relative degrees of importance determined the final outcome. Following an introduction to the practical case study research, dealing with general issues such as picture policy in newspapers and decision-making procedures, each case study is dealt with in turn. After an outline of the context in which the event occurred, the kinds of pictures that were available to the newspapers are described. Then the decisions taken about which to choose and how to use them are analysed in terms of dominant themes. These are themes such as newsworthiness, gruesomeness of content and concern abo!Jt what other media were using. The analysis examines the way the news context and the decision-making context determine the relative importance of the various factors present. Finally the study looks at the conclusions that can be drawn from the five case studies. The conclusion supports the initial hypothesis in finding that these decisions can be shown to have their basis in a fairly limited set of factors. The different results, from study to study and from newspaper to newspaper within a study, are determined by the changing news context and the decisi~n-making context.
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  • Date Issued: 1997

An investigation into patterns of interaction in small teaching groups at Rhodes University, with particular emphasis on the effect of gender, mother-tongue and educational background

  • Authors: Hunt, Sally Ann
  • Date: 1997
  • Subjects: Tutors and tutoring , Multicultural education--South Africa , Group work in education , Small groups--Study and teaching (Higher)
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:2350 , http://hdl.handle.net/10962/d1002632 , Tutors and tutoring , Multicultural education--South Africa , Group work in education , Small groups--Study and teaching (Higher)
  • Description: The assumption underlying this study is that knowledge is constructed through interaction. Small teaching groups, or tutorials, are often regarded as a particularly effective context for learning in the setting of tertiary education in that they provide an environment for free interaction between students, and thus facilitate active learning. Factors which systematically affect the degree of participation of the individual in tutorIals -directly affect the learning experience of that individual and raise questions about the equality achieved in tutorials, in terms of opportunities for learning. This study focuses on one such type of factor: culturally acquired norms of interaction. The individual is seen as a composite of cultural identities, utilising norms acquired through socialisation and experience in appropriate contexts. Previous research has demonstrated that gendered norms of interaction and those associated with the individual's mother-tongue are particularly salient. In the educational context, norms acquired through previous experience of education are likely to be carried over to the new setting of the university. Thus these factors form the focus of this study. One flrst-year tutorial from each of five departments in the Faculties of Arts and Social Science at Rhodes University, Grahamstown, was video-recorded and the data thus obtained was analyzed for patterns of interaction in terms of gender, mother-tongue and educational background. A model of utterance types was developed to provide a structured description of the patterns found in the tutorials. Interviews and video-sessions with a sample of the tutorial members were conducted, which add a qualitative dimension to the investigation and allow for triangulation. The recorded tutorials and interviews reveal a marked awareness amongst students of the composition of tutorial groups in terms of gender and ethnicity and this composition appears to affect the relative participation of students, in that members of numerically dominant groups are more willing to participate. This is particularly clear in the case of female students. With regard to second-language (L2) speakers of English, a number of factors are highlighted which tend to decrease participation. Apart from problems with English as the medium of instruction, these students tend to be reluctant to participate due to cultural norms, according to which students, as subordinates, should not take the initiative in interaction, in order to show appropriate respect. Patterns of interaction by L2 students from racially integrated schools, however, do not conform to this set of norms as strongly. It is argued that sensitivity is required to address this situation and a number of options are presented.
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  • Date Issued: 1997

An investigation into the effects of inorganic toxins and tryptophan metabolites on the forebrain cholinergic system and the pineal gland of the rat

  • Authors: Mahabeer, Rajeshree
  • Date: 1997
  • Subjects: Toxins -- Physiological effect , Metabolites -- Physiological effect , Pineal gland , Brain -- Physiological aspects
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4018 , http://hdl.handle.net/10962/d1004078 , Toxins -- Physiological effect , Metabolites -- Physiological effect , Pineal gland , Brain -- Physiological aspects
  • Description: As soon as the building of the body is completed, the ageing process begins. In the natural course of events, the functioning of some organ systems finally ebbs below the threshold necessary to maintain the body, resulting in death. This occurrence is relatively rare, because diseases superimpose themselves upon the ageing process, bringing premature death resulting from pathological causes. This study focused on the cholinergic system of the rat forebrain. The cholinergic neurons in the brain are said to be involved in memory and learning, and a decrease in the activity of its enzymes has been reported in certain diseases, such as Alzheimer's disease. In the present study, the in vitro effects on the cholinergic system, of aluminium and mercury and tryptophan metabolites, kynurenic acid and quinolinic acid, are determined. Aluminium has been considered as a possible factor in Alzheimer's disease. Mercury in high concentrations is toxic, and its use in amalgam for dental treatment is under consideration with regard to its possible role in promoting neurological disease. The tryptophan metabolites increase in the brain with age and may have a role in pathological diseases. Quinolinic acid, when administered in toxic concentrations produces a possible model for Huntington's disease. This study investigated the effects of the above mentioned toxins on: (1) The synthesis of acetylcholine by choline acetyltransferase; (2) The specific binding of acetylcholine muscarinic receptors; (3) The degradation of acetylcholine by acetyl cholinesterase, Choline acetyltransferase activity did not change in the presence of aluminium chloride, kynurenic acid and quinolinic acid from 1 nM to 1 mM. Mercuric chloride had no significant effect on the enzymes activity from a concentration of 1 nM- 1 pM. At 10 pM there was a significant decrease in cholineacetyltransferase activity (P < 0.001). Enzyme activity continued to decrease at 100 pM (P < 0.0002). At 1 mM, enzyme activity was virtually non existent (P < 0.0001). Acetyl cholinesterase activity was not affected by aluminium chloride, kynurenic acid and quinolinic acid. Mercuric chloride from 1 pM - 1 mM significantly reduced the enzyme activity (P < 0.05). The binding of the antagonist, [³H] quinuclidinyl benzilate (QNB), to acetylcholine muscarinic receptors, revealed that aluminium chloride did not affect the binding of the antagonist, in the concentration range of 1 nM - 100 pM, to the receptors. At 1 mM, aluminium chloride appears to increase the sensitivity of the receptors for the ligand (P < 0.01). Mercuric chloride also does not appear to have any significant effect on receptor binding in this range. However, at 1 mM there appears to be a very significant decrease in receptor binding (P < 0.01). This decrease may be attributed to the interaction of mercury with the sulfhydryl groups in muscarinic receptors. Kynurenic acid had no effect on the receptor binding. Quinolinic acid, in the concentration range from 10 nM - 1 mM increased the binding ofthe receptor to [3Hi QNB significantly (P < 0.001). The study also investigated the effect of the tryptophan metabolites of the kynurenine pathway on pineal indole metabolism. The kynurenine pathway is a major route of tryptophan metabolism in the pineal gland, along with indole metabolism. Investigations showed that kynurenic acid produced a decrease in N-acetylserotonin concentrations ( P < 0.001) and melatonin concentrations (P < 0.003). Further experiments using quinolinic acid produced a similar decrease in N-acetylserotonin (P < 0.001) and melatonin (P < 0.015). A decrease was also noted in the level of 5-methoxytryptophol (P < 0.0005). These findings suggest that aluminium chloride, kynurenic acid and quinolinic acid have no possible role in the decrease of activity of cholinergic enzymes which is observered in diseases such as Alzheimer's disease. The results regarding the effect of mercury chloride on the cholinergic system suggest that low exposure to the toxin will not adversely effect the enzymes. The decrease in N-acetylserotonin and melatonin concentrations reported here, may be a result of kynurenic acid and quinolinic acid having an inhibitory effect on the enzyme, serotonin Nacetyltransferase, which is responsible for the conversion of serotonin to N-acety/serotonin.
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  • Date Issued: 1997

An investigation into the enlightenment and aspects of Spanish life which may have influenced Los Caprichos (1797-1799) of Francisco de Goya (1746-1828)

  • Authors: Ralls, Warren John
  • Date: 1997
  • Subjects: Goya, Francisco, 1746-1828 -- Criticism and interpretation Goya, Francisco, 1746-1828. Caprichos
  • Language: English
  • Type: Thesis , Masters , MFA
  • Identifier: vital:2421 , http://hdl.handle.net/10962/d1002217
  • Description: The aim of this mini-thesis was to investigate if the Spanish artist Francisco Jose de Goya y Lucientes (1746-1828) was aware of the progress that enlightened thought brought to Spain during the late eighteenth-century, and to see whether this had any effect on his series Los Caprichos (1797-1799). According to some contemporary historians, such as Dowling (1985, p. 347), the " ... specific subject-matter of the Caprichos came directly from the ideology of the Spanish Enlightenment. " The contemporary historian Jeremy Black (1990, p. 208) described the Enlightenment as a " ... tendency towards critical enquiry and the application of reason." Enlightened thinkers were primarily critics who used reason as a goal and a method to create a better society. Reason was believed to be a characteristic trait of the human species, human development and social organisation. The Enlightenment is not a purely seventeenth and eighteenth century phenomenon, but originated in the ideas of the classical civilizations and also the humanism of the Middle Ages and Renaissance in Europe. Many intellectuals were responsible for this new direction of thinking. The ideas of these scientists and philosophers are discussed in some detail, especially those beliefs which are clearly seen in the subject-matter of Los Caprichos. In addition, consideration is given to the possible effects of some of the historical events on the life and work of Goya, for example, the French Revolution (1789) and the Reign of Terror (1793-1794) which followed the Revolution. In order to understand the background of the environment into which Goya was born and in which he developed, research was done on Spanish life and the monarchs of the eighteenth century. Specific attention is given to two Spanish kings from the House of Bourbon: Charles 3, who began numerous enlightened reforms in Spain and reigned around the time of Goya's early artistic and social development, and Charles 4 who did not continue the reforming policies of his father and ruled Spain when the Caprichos were produced. The extent to which the Enlightenment spread to Spain is investigated, especially during the period in which Goya lived. Notable progressive thinkers of this European country are discussed, and special attention is given to those open-minded people whom Goya met. There appears to be proof that Goya may have been inspired by numerous of these learned Spaniards, and where this has motivated the Caprichos, special mention is made. The general census of the twentieth century, however, seems to be that Goya was not a towering intellectual thinker, but he was most certainly not an illiterate, unintelligent person either. The themes of Los Caprichos strongly suggest that he was influenced by enlightened individuals many of whom were his friends, such as the wealthy businessman and art-collector Sebastian Martinez (17 ?-1800) (with whom Goya stayed during a serious illness in 1792-1793). The letters written by Goya to his childhood friend Martin Zapater (1746-18 ?) and selected prints from the Caprichos provide sufficient proof to indicate that enlightened thought inspired the work of Goya. It must be recognised, however, that there were other events that could have been influential such as: his appointment as Painter to the King in 1786, which provided Goya with a regular salary and released him from the demands of patrons, giving his imagination free reign; the illness that he suffered from 1792 until 1793, which could have caused Goya to view his life in perspective and could have given him the courage to criticise society. On a smaller scale, the possible love affair that Goya had with the Duchess of Alba, which turned sour, was possibly a blow to his self esteem. This is a subject which is seen in a few of the prints from Los Caprichos. The research gathered for this mini-thesis is from the ex post facto source-material available through Rhodes University library, and any other attainable published data connected to Goya. This information consists of secondary sources which include copies of manuscripts dating from the time of Goya as well as first-hand observations of Goya's art.
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  • Date Issued: 1997

An investigation into the visual literacy skills of Black primary-school children from an informal settlement in Cape Town, with particular reference to visual imagery in educational textbooks

  • Authors: Griffiths, Corona Gracelyn
  • Date: 1997
  • Subjects: Textbooks Illustrations , Visual literacy , Literacy -- South Africa , Visual literacy -- South Africa , Visual communication , Black people -- Education (Primary) -- South Africa , School children -- South Africa
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:2403 , http://hdl.handle.net/10962/d1002199 , Textbooks Illustrations , Visual literacy , Literacy -- South Africa , Visual literacy -- South Africa , Visual communication , Black people -- Education (Primary) -- South Africa , School children -- South Africa
  • Description: This thesis provides evidence that learning difficulties some. black primary-schoolchildren may experience with certain textbooks, can be attributed, in part, to the visual text (imagery). These difficulties were established by eliciting responses from educationally dlscfdvantaged urban black primary learners to selected examples of visual texts using the Research Interview method. To further establish if these difficulties were attributable either to poorly executed/unrecognizable visual text, or to low levels of learned educational visual literacy skills - white primary-school children were also interviewed - as it was anticipated that they would be familiar with Western pictorial material due to their consistent exposure to books from an early age. The difficulties experienced by the black interviewees were attributed mainly to their level of learned pictorial perceptual skills and to a lesser extent to poorly/inadequately illustrated visual texts. It was found from interviews with the developers of visual texts - publishing personnel and illustrators - that the former were not entirely certain e.xactly which aspects of visual text were difficult for black primary learners to comprehend, while the latter were generaUy very uncertain. The procedure for visual text development by the developers (including textbook authors), was found to be problematic due to the lack of synthesis and consultative decision making in the process- between these persons. The limited time allocated to illustrators for producing visual text, as well as their professional isolation, were found to be factors which can give rise to ineffective and inadequate visual texts. Most publishers and authors, if they trial (field-test) materials, generally do not trial the visual text. The visual text is usually decided upon ultimately by the poblishers and produced after trialling and/or consultants have examined the written text. Consequently incongruent meanings and inconsistencies can result between written and visual text, which can affect the learning effectiveness of the composite text. Trialling (field-testing) of visual and written text together, was recommended to identify and address any difficulties experienced by learners prior to final publication of the textbook. Recommendations were provided for textbook selection committees, authors, teachers, publishers and illustrators.
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  • Date Issued: 1997

An investigation of nondeterminism in functional programming languages

  • Authors: Graham, Gwyneth Clare
  • Date: 1997
  • Subjects: Functional programming languages
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4658 , http://hdl.handle.net/10962/d1006658 , Functional programming languages
  • Description: This thesis investigates nondeterminism in functional programming languages. To establish a precise understanding of nondeterministic language properties, Sondergaard and Sestoft's analysis and definitions of functional language properties are adopted as are the characterizations of weak and strong nondeterminism. This groundwork is followed by a denotational semantic description of a nondeterministic language (suggested by Sondergaard and Sestoft). In this manner, a precise characterization of the effects of strong nondeterminism is developed. Methods used to hide nondeterminism to in order to overcome or sidestep the problem of strong nondeterminism in pure functional languages are defined. These different techniques ensure that functional languages remain pure but also include some of the advantages of nondeterminism. Lastly, this discussion of nondeterminism is applied to the area of functional parallel language implementation to indicate that the related problem and the possible solutions are not purely academic. This application gives rise to an interesting discussion on optimization of list parallelism. This technique relies on the ability to decide when a bag may be used instead of a list.
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  • Date Issued: 1997

An overview of the early-proterozoic, auriferous Black Reef placer in the Transvaal Basin

Application of capillary electrophoresis for the assay of erythromycin and its related substance

  • Authors: Lalloo, Anita Kantilal
  • Date: 1997
  • Subjects: Antibiotics -- Analysis , Capillary electrophoresis , Erythromycin -- Analysis
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:3765 , http://hdl.handle.net/10962/d1003243 , Antibiotics -- Analysis , Capillary electrophoresis , Erythromycin -- Analysis
  • Description: Capillary Electrophoresis (CE) is a high resolution analytical technique that may be employed in the separation and quantification of a wide range of analytes. The enormous efficiency obtained in CE are well suited for complex mixtures in which resolution of a large number of peaks in a short time is desirable. Therefore, CE has a promising future in pharmaC-eutical analysis. The separation mechanism of CE is based on the differential electrophoretic mobility of the solutes inside a buffer filled capillary upon the application of a voltage. Capillary electrophoresis is especially suitable for ionic species. The full potential of this technique can only be realised through the manipulation of numerous experimental parameters. In the present study, a CE method has been developed for the analysis of the macrolide antibiotics: erythromycin, oleandomycin, troleandomycin and josamycin. The selection of initial analysis conditions and optimisation of selectivity are reviewed. A systematic approach to method development was used to maximise analyte differential electrophoretic mobilities, by adjusting the pH. Thereafter, the influences of electrolyte molarity and electrolyte additives were investigated. In addition, some instrumental parameters, such as capillary length emf diameter, applied voltage and injection conditions were varied. The effect of the sample solvent and oncapillary concentration techniques such as FASI, were investigated. Also, the influence of injecting a water plug on the quantity of sample injected was demonstrated. Full resolution was achieved with the addition of methanol to the electrolyte. The applicability of CE for the assay of erythromycin and its related substances was investigated. Two methods were developed and successfully validated using CE: one for the quantitative determination of erythromycin alone and another for erythromycin related substances in the presence of large quantities of erythromycin A. Several related substances and impurities that result from the fermentation process used to produce erythromycin as well as degradation products are known to be present in commercial sa~ples. These impurities include erythromycin B, C, D, E, F, erythromycin enol ether, anhydroerythromycin and N-demethylerythromycin. Currently both the USP and BP official assays for the analysis of erythromycin involve the use of microbiological assays. These methods are limited as they are unable to differentiate between erythromycin and its related substances and degradation products. Furthermore, the microbiological assays are time-consuming and tedious to perform. 11 The CE methods developed for the analysis of erythromycin and for its related substances were fully validated in terms of precision, linearity, accuracy, sensitivity and stability. In addition, erythromycin was subjected to six stress modes and the stressed samples were analysed. An intemal standard was employed to provide acceptable precision for the migration time « 1.80 % RSD) and peak area « 4.44 % RSD). Optimum sensitivity was obtained using low UV wavelengths, with LOO values of less than 10 % for the related substances. The developed method was accurate for erythromycin C, anhydroerythromycin and N-demethylerythromycin, even in the presence of large concentrations of the parent. The method for~ erythromycin related substances was applied to the determination of impurities in three commercial erythromycin bases. The CE methods developed were rapid, precise, specific and stability-indicating and may be used to provide additional information to augment that attained by HPLC for purity assessment and in stability studies of erythromycin. Capillary electrophoresis is a simple, cost-effective technique that is capable of generating high quality data. This technique will become firmly established within pharmaceutical analysis for main peak and related impurity determination assays as familiarity becomes more widespread across the pharmaceutical industry and improvements in instrumentation are performed.
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  • Date Issued: 1997

Assessment of amoxycillin suppositories

  • Authors: Webster, Jessica Angela
  • Date: 1997
  • Subjects: Solid dosage forms , Suppositories , Amoxicillin
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:3802 , http://hdl.handle.net/10962/d1003280 , Solid dosage forms , Suppositories , Amoxicillin
  • Description: The investigations in this dissertation have been 'conducted to investigate the formulation and analysis of a paediatric amoxycillin suppository. The oral administration of antibiotics to young children can at times be roblematic. Compliance is sometimes poor because of a sore throat, nausea, vomiting, a high fever or a dislike for the taste or smell of the medicine:- In-such cases the rectal administration of an antibiotic could provide an alternative route of administration that avoids some of the problems that affect oral administration. Difficulties associated with rectal administration are bioavailability, local irritation, acceptability to patients and rejection of the dosage form. Few data, however, are available on the usefulness in children of suppositories in general, and antibiotic suppositories in particular. The areas of investigation have included the formulation of an amoxycillin suppository in various fatty bases, the quantitation of amoxycillin in both aqueous solution and human serum, assessment of stability of amoxycillin in stored aqueous and biological samples, in vitro drug release testing of suppositories, and bioavailability and pharmacokinetics following administration to human subjects of capsule, suppository, oral suspension and rectal suspension dosage forms. Suppositories containing 250 mg amoxycillin were prepared in theobroma oil and in the semisynthetic bases Witepso[ W35, Suppocire A32, Novata BD and Novata 299. The in vitro release characteristics of amoxycillin from these lipophilic suppository formulations were investigated using the USP rotating basket method. The dissolution of a drug from a solid dosage unit is an important parameter affecting drug bioavialability. High Performance Liquid Chromatography (HPLC) was used as the main analytical technique. An original HPLC method for analysis of amoxycillin in aqueous solution, using ultraviolet detection at 230 nm was develcfped. The validated method was a~plied to the determination of the stability of aqueous amoxycillin solutions, and was utilized to determine the amount of drug released during dissolution testing. Differential scanning calorimetry (DSC) is a technique commonly used in preformulation studies. Dissolution testing was used in conjunction with DSC to select a suppository base suitable for formulation with amoxycillin trihydrate. An HPLC method for analysis of amoxycillin in human serum using UV detection at 230 nm is presented. The method involves a solid phase extraction procedure followed by chromatography on a reversed phase column. The limit of sensitivity of 0.3 ILg/mL in serum is sufficiently sensitive to monitor serum concentrations of amoxycillin in humans after the administration of a single 250 mg oral dose. Pharmacokinetic parameters were calculated from data obtained following the administration of a capsule and oral suspension. These parameters were consistent with previously published results. Following administration of a lipophilic suppository and a rectal suspension, to human volunteers, it was concluded that amoxycillin trihydrate is not readily absorbed from the rectum. Further investigations into the modification of the suppository dosage form with absorption enhancers to improve rectal absorption of amoxycillin, as well as elucidation of the mechanism of absorption of the drug, could assist in improving this formulation so that it is suitable for paediatric use.
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  • Date Issued: 1997

Bayeza kusasa

Belethe

Belethe

Belethe

Bells and bellfounders of the Eastern Cape, South Africa

  • Authors: Lewis, Colin A
  • Date: 1997
  • Language: English
  • Type: Article
  • Identifier: vital:6179 , http://hdl.handle.net/10962/d1012372 , http://www.ringingworld.co.uk
  • Description: [From Introduction] Although there is only one ring of bells in the whole of the Eastern Cape almost every church, and many chapels, have one or more bells. No systematic study of these bells had yet been made, but cursory examination suggests that many British founders exported bells to that area in the late 19th century and in the 20th century. American founders of steel bells also peddled their wares with considerable success. The Irish bell founder: Matthew O'Byrne sold at least five bells to clients in the Eastern Cape, the largest of which weighed 16 cwts. In the 1950s the Swiss founder, Ruetschi, of Aarau, cast at least four beautiful bells that are now in the Transkei. , Colin Lewis was Professor of Geography at Rhodes University, Grahamstown, South Africa from 1989 until his retirement at the end of 2007. In 1990, with the strong support of the incumbent Vice-Chancellor, Dr Derek Henderson, he instigated the Certificate in Change Ringing (Church Bell Ringing) in the Rhodes University Department of Music and Musicology - the first such course to be offered in Africa. Since that date he has lectured in the basic theory, and taught the practice of change ringing. He is the Ringing Master of the Cathedral of St Michael and St George, Grahamstown, South Africa.
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  • Date Issued: 1997

BI-Annual National Conference - Fisheries Policy and Response to White Paper

  • Authors: Food and Allied Workers Union (FAWU)
  • Date: 1997
  • Subjects: COSATU
  • Language: English
  • Type: text
  • Identifier: http://hdl.handle.net/10962/110077 , vital:33221
  • Description: This paper is intended to serve as an aid to discussion in the Commission dealing with Sea Fisheries. Accordingly, its various sections provide an overview of the key issues which can inform discussion. Historically, access to marine resources was unrestricted. In order to facilitate the monopolisation of the fishing resource by a few white companies, a system of quotas was introduced. In this way many black fisher folk lost the access rights they had had for generations. At the present time, the fishing industry is completely biased in favour of a few large and medium sized white companies. This is illustrated by the fact that just three (3) companies hold;72% of the hake quota ;75% of the abalone quota , and 71 % of the sole quota. Overall , across all species, approximately nine tenths (9/10) of the resource is controlled by a hand-full of companies. Since 1994, some of these companies have attempted to blacken their faces. They have also sold minority shares to some, black business consortia. Further, a few members of the black elite have been given quotas. None of the above amounts to any kind of restructuring. None of the historic imbalances have been addressed. The above have merely been attempts to confuse the issue and to frustrate any process that attempts to restructure the industry. Prior to, and after the 1994 election, there were various initiatives by Alliance members to outline an equitable and just policy of reconstruction and development for the fishing industry.
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  • Date Issued: 1997

Bioaccumulation of heavy metals by the yeast S. cerevisiae and the bioremediation of industrial waste water

  • Authors: Stoll, Anita
  • Date: 1997
  • Subjects: Saccharomyces cerevisiae Yeast fungi -- Biotechnology Metal ions Bioremediation Water -- Purification -- Biological treatment
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:4015 , http://hdl.handle.net/10962/d1004075
  • Description: Water is an essential element in all aspects of life and is vital for both domestic and industrial purposes regarding both the quality and quantity thereof. Similar to many other drought stricken countries, South Africa requires water for the socio-economic growth of the country, yet is faced with the problem of maintaining the quality of its drinking water as well as protecting the dwindling supplies. In an attempt to prevent the deterioration of South African water supplies the treatment, purification and recycling of industrial and mining waste water has recently become of prime importance. Many industrial and mining waste waters contain heavy metals in toxic quantities. The conventional processes that have been used till recently to address this problem, are often expensive or contain chemical agents which compound the environmental problem. As an alternative biological methods of metal accumulation appear to offer an economic and efficient alternative to these methods. An advantage to the South African scenario is the commercial production of the yeast, S. cerevisiae as a readily inexpensive by-product from some fermentation industries, Yeast cells, and in particular S. cerevisiae have proven to be capable of accumulating heavy metals, and therefore exhibit potential application in the bioremediation of waste water. The aim of this project was twofold. The initial part of this work attempted to define the mechanisms of metal accumulation by the yeast cells and cellular components. The information obtained from these initial studies provided a data base required for the development of a bioremediation system. Initial contact with the metal ions occurs at the wall interface of the yeast cell. Metal accumulation appears to be a function of all the cell wall components. The isolated cell wall components are better metal chelators then the intact cell walls. An apparent affinity series of mannan > chitin> glucan > intact cell walls exists. However, these components differ in their affinities for metal ions. Storage of metal ions within the cell occurs predominantly in the vacuole. The present study concluded that metal accumulation by the vacuole could be related to size. Metal accumulation occurred in the order of Cu2+ > Co2+ > Cd2+ with a corresponding decrease in atomic radii of Cd2+ > C02+ > Cu2+. Vacuolar ion deposition occurs at an early stage during the internalization of metal ions within the yeast cells. At the onset of vacuolar saturation, depositions of metal ions as granules within the cytosol occurs. In the presence of heavy metal cations viable yeast cells can be shown to exhibit two types of cellular responses. Uptake of Cu2+ and Cd2+ causes the loss of intracellular physiological cations from within the yeast cell. In comparison, uptake of Co2+ into the cell does not have this effect. All three heavy metal cations initiate plasma cell membrane permeability, thus the Cu2+ and Cd2+ induced loss of the intracellular cations, occurs. ~ a result of ion-exchange mechanisms and not due to cation leakage brought about by membrane permeabilization. Uptake of heavy metals by viable yeasts appears to be generally non-selective though the amount of metals accumulated are largely affected by the ratio of ambient metal concentration to biomass quantity. In addition, the energy dependent nature of internalization necessitates the availability of an external energy source for metal uptake by viable yeast cells. For these reasons metal removal from industrial waste water was investigated using non-viable biomass. By immobilizing the yeast cells additional mechanical integrity and stability was conferred apon the biomass. The three types of biomass preparations developed in this study, viz. polyvinyl alcohol (PV A) Na-alginate, PV A Na-orthophosphate and alkali treated polyethylenimine (PEI):glutaraldehyde (GA) biomass pellets, all fulfilled the necessary physical requirements. However, the superior metal accumulating properties of the PEI:GA biomass determined its selection as a biosorbent for bioremediation purposes. Biosorption of heavy metals by PEI:GA biomass is of a competitive nature, with the amount of metal accumulated influenced by the availability of the metal ions. This availability is largely determined by the solution pH. At low pH values the affinity of the biomass for metals decreases, whilst enhanced metal biosorption occurs at higher pHs, ego pH 4.5 - 6.0. PEI:GA biomass pellets can be implemented -as a biosorbent for the bi9remediaiton of high concentration, low-volume metal containing industrial waste. Several options regarding the bioremediation system are available. Depending on the concentration of the metals in the effluent, the bioremediation process can either be used independently or as part of a biphasic remediation system for the treatment of waste water. Initial phase chemical modification may be required, whilst two types of biological systems can be implemented as 'part of the second phase. The PEI:GA biomass can either be contained within continuous-flow fixed bed tanks or continuous-flow stirred bioreactor tanks. Due to the simplicity of the process and the ease with which scale-up is facilitated, the second type of system shows greater application potential for the treatment of this type of industrial waste water than the fixed-bed systems.
  • Full Text:
  • Date Issued: 1997

Biologically active natural products from South African marine invertebrates

  • Authors: Hooper, Gregory John
  • Date: 1997
  • Subjects: Natural products -- South Africa Marine metabolites -- South Africa Marine invertebrates -- South Africa
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:3761 , http://hdl.handle.net/10962/d1003239
  • Description: This thesis describes the chemical and biological investigation of the extracts of six different marine invertebrate organisms collected along the South African coastline. The work on these extracts has resulted in the isolation and structural elucidation of twenty-one previously undescribed secondary metabolites; The history of marine natural product chemistry in South Africa has not previously been reviewed and so a comprehensive review covering the literature from the 1940's up until the end of 1995 is presented here. The marine ascidian Pseudodistoma species collected in the Tsitsikamma Marine Reserve was shown to contain four new unsaturated amino alcohols [47], [48], [49] and [50] which were isolated as their acetyl derivatives. These compounds exhibited strong antimicrobial activity. Four new pyrroloiminoquinone alkaloids, the tsitsikammamines A [90] to D [93],were isolated from a new genus of Latrunculid sponge collected in the Tsitsikamma Marine Reserve. These highly pigmented compounds also possessed strong antimicrobial activity. An investigation of two phenotypic colour variants of the soft coral Capnella thyrsoidea resulted in the isolation of the known steroid 5α-pregna-1, 20-dien-3-one [97] and an additional six new metabolites, 16β-hydroxy-5α-pregna-1 ,20-dien-3-one 16-acetate [98], 3α,16β-dihydroxy-5α-pregna-1, 20-diene 3,16-diacetate [99] and four xenicane diterpenes, the tsitsixenicins A [100] to D [103]. This is the first reported isolation of xenicane diterpenes from the soft coral family Nephtheiidae. Tsitsixenicin A and B showed good anti-inflammatory activity by inhibiting superoxide production in both rabbit and human cell neutrophils. A further four new metabolites were isolated from two soft corals which could only be identified to the genus level and were designated Alcyonium species A and species B. Alcyonium species A was collected in the Tsitsikamma Marine Reserve and yielded two new polyhydroxysterols, cholest-5-ene-3β, 7β, 19-triol 19-acetate [121] and cholest-5,24-diene-3β, 7β, 19-triol 19-acetate [122]. The soft coral Alcyonium species B was collected off Aliwal Shoal and was found to contain two known xenicane diterpenes, 9-deacetoxy-14, 15-deepoxyxeniculin [110] and zahavin A [16], and two new xenicane diterpenes, 7 -epoxyzahavin A [123] and xeniolide C [124]. Compounds [110], [16] and [123] exhibited strong anti-inflammatory activity and compounds [110] and [16] showed good antithrombotic activity. The endemic soft coral A/cyanium fauri collected at Riet Point near Port Alfred yielded the new sesquiterpene hydroquinone rietone [141] in high yierd, fogether with the minor compounds 8'-acetoxyrietone [142] and 8'-desoxyrietone [143]. Rietone exhibited moderate activity in the NCl's in-vitro anti-HIV bioassays.
  • Full Text:
  • Date Issued: 1997

Breaking the karmic complex: the role of transpersonal phenomena in psychotherapy with an adult survivor of child abuse : a clinical case study

  • Authors: Oberholzer, Sofia Adriana
  • Date: 1997
  • Subjects: Transpersonal psychology Reincarnation Adult child abuse victims -- Treatment
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:3034 , http://hdl.handle.net/10962/d1002543
  • Description: This longitudinal study addresses the interface between the emerging paradigm of Transpersonal Psychology, which recognizes the transbiographical domain of consciousness, and the clinical area of child abuse. By using the transpersonal concept of the karmic complex, which was developed in the discourse of Roger Woolger, it explores the clinical value of past-life regressions and other transpersonal phenomena in the therapeutic process. The study provides an in-depth phenomenological description and a theoreticalheuristic explication of the experience of a single subject who was an adult survivor of physical and sexual abuse as well as early emotional deprivation in childhood, and who, over a four-year period of intensive psychotherapy, experienced a wide spectrum of transpersonal phenomena which included 123 past-life regressions. The therapeutic process could be clearly delineated into a biographical phase, which was dominated by biographical traumas, and a subsequ~nt transpersonal phase, during which the focus was almost exclusively on transpersonal material. This provided the opportunity to explore the therapeutic impact of trans personal mechanisms" of healing on an interlocking constellation of complexes in terms of achieving an integration of archetypal opposites in the psyche. The study provides strong support for transpersonal concepts about the nature of consciousness, as developed by Grof and Woolger. It affirms spirituality as an intrinsic property of the psyche, and verifies that the healing of psychological trauma is on a continuum with the process of spiritual purification and growth. The ,study establishes support for the clinical value of the karmic complex as a conceptual tool and provides a systematic, extended analysis of the multi levelled processes involved in the breaking of the complex.
  • Full Text:
  • Date Issued: 1997

Catalytic behavior of osmium (II), rhodium (III) and ruthenium (II) Phthalocyanines towards the electrooxidation of cysteine on glassy carbon electrodes

  • Authors: Sekota, Mantoa , Nyokong, Tebello
  • Date: 1997
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/293290 , vital:57072 , xlink:href=" https://doi.org/10.1002/elan.1140091608"
  • Description: Glassy carbon electrodes (GCE's) modified with phthalocyanine complexes of Rh, Ru and Os are employed for the catalytic oxidation of cysteine. When cyanide and dimethylsulfoxide (DMSO) are used as axial ligands giving (DMSO)(Cl)RhIIIPc, [(CN)2RhIIIPc]−, (DMSO)2OsPcII, and [(DMSO)2Ru(II)Pc]·2DMSO complexes, the peak currents for the oxidation of cysteine increase after each scan, indicating an increase in the catalytic activity of the electrode with repetitive scanning. This improvement in the catalytic activity of the GCE after the first scan is attributed to the formation of dimeric π cation radical species at the electrode surface.
  • Full Text:
  • Date Issued: 1997
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