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Requiem for SA Jazzman

The spiral curriculum, integrated teaching and structured learning of mathematics at the secondary level

  • Authors: Alummoottil, Joseph Michael
  • Date: 1990
  • Subjects: Mathematics -- Study and teaching (Secondary) -- South Africa Learning -- Mathematical models -- Research
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:1769 , http://hdl.handle.net/10962/d1003654
  • Description: The investigator's experience of teaching mathematics at a college of education since 1983 has reinforced his conviction that trainee students come to college with significant gaps, weaknesses and faults in their (mathematical) conceptual structures, probably as a result of shortcomings in the mathematics teaching to which they have been exposed. The theme of this investigation is thus a natural choice that appeared to be of immediate relevance to secondary school mathematics teaching. The analysis of the issue leads to a unified perspective: the problem is placed in a theoretical framework where Bruner [spiral curriculum], Ausubel [structured learning] and Skemp [relational understanding] are brought together. How the curriculum, textbooks and examination influence school mathematics teaching is examined in some depth and the consequences investigated. Two specific topics, viz. the generalised Pythagorean relation and absolute value are investigated in relation to published work, curriculum and textbooks, and each (topic) is presented as a unifying theme in secondary mathematics to standard 9 pupils. The classroom exercise is assessed to test the hypothesis that structured, integrated presentation around a spiral curriculum promotes "relational understanding". Analysis of results supports the hypothesis.
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  • Date Issued: 1990

The applicability of two simple single event rainfall-runoff models to catchments with different climate and physiography

  • Authors: Beater, Anne Brenda
  • Date: 1990
  • Subjects: Hydrogeology Runoff -- South Africa Runoff -- United States Rain and rainfall -- South Africa Rain and rainfall -- United States
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4796 , http://hdl.handle.net/10962/d1001896
  • Description: The study presents the results of applying two isolated event, constant runoff proportion, conceptual models to a range of catchments drawn from various climatic and physiographic regions of South Africa and the USA. The models can be operated in either lumped or semi-distributed modes. The research progressed through the following stages. The initial stage involved the calibration of both models on two sets of catchments so that an initial evaluation of the performance of the models could be carried out and any deficiencies in the model structure identified, and where practical, corrected. The models were then calibrated on a further 8 catchments. An important result of the calibration is that for both models to produce reasonably acceptable simulations, at least one parameter has to vary between storms on the same catchment to account for variations in storm or antecedent moisture characteristics. The next stage consisted of compiling quantitative descriptions of the physical characteristics of the catchments and rainfall events and an attempt to relate the calibrated parameter values to relevant physical characteristics for the purpose of estimating parameter values when calibration is not possible. Despite the difficulties encountered in quantifying some of the hydrological characteristics the general trends exhibited by many of the relationships are encouraging and the format of the combinations of physical variables used, do make sense with respect to the original parameter conceptualisations. The relationships between storm characteristics and parameters of both models are less satisfactory. There is a high degree of scatter and the between-catchment variation in the form of the relationships, indicates that the derived relationships are likely to be of little use for parameter estimation purposes. The final stage involved a validation exercise in which new parameters were estimated from the physical variable-parameter relationships for all the catchments previously used, as well as a further four. The new parameters were used to re-simulate all the storms and comparison of these results were made with the original calibration results. Both models produced poor results and are unlikely to give reliable results where calibration is not possible. The parameter relationships for the parameters related to storm characteristics are so catchment specific that transfer to other areas will produce unpredictable results. Foot note:- For compatability with computer printouts decimal full stops are used in the format of real numbers in tables etc
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  • Date Issued: 1990

Immunolocalisation of, and ultrastructural changes in the LH gonadotropes of Miniopterus schreibersii and Rhinolophus capensis (Mammalia: Chiroptera) in relation to their reproductive cycles

  • Authors: Bojarski, Christina
  • Date: 1990
  • Subjects: Bats -- Reproduction
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5589 , http://hdl.handle.net/10962/d1002039
  • Description: LH gonadotropes are successfully identified in the anterior pituitary of Minioptems schreibersii and Rhinolophus capensis, using immunogold labelling at the light and electron microscopy level. The gonadotropes are oval to polygonal in shape and possess numerous small secretory granules, which contain LH throughout the year. Their distribution is similar in both species, although the abundance varies slightly between species and sexes. Seasonal changes are detected in gonadotrope ultrastructure, pituitary LH levels, and plasma hormone levels, and activity pattern of LH gonadotropes generally coincide with reproductive activity in both bat species. In female M. schreibersii gonadotrope activity, pituitary LH, and plasma LH levels coincide with development, implantation and gestation. During the delayed implantation gonadotropes are inactive and and high follicular period of plasma LH levels are low, coinciding with corpus luteum inactivity and low plasma progesterone levels. Implantation coincides with increased activity of the gonadotrope activity, increased plasma LH levels, reactivation of the corpus luteum and elevated plasma progesterone levels. Activation of LH gonadotropes towards the end of hibernation may be initiated by the winter solstice, which marks the change to increasing daylength. In female R capensis gonadotrope activity and high pituitary and plasma LH levels occur towards the end of follicular development. During hibernation gonadotrope activity and plasma LH levels decrease. Ovulation coincides with increasing gonadotrope activity (which follows the winter solstice), although a preovulatory peak in plasma LH is not detected. In male M. schreibersii and R. capensis, gonadotrope activity and high plasma LH and testosterone levels coincide with spermatogenesis, except during a period of reproductive inactivity in spring in male M. schreibersii, where gonadotropes appear active and plasma LH and testosterone levels are high. The reason for this apparent activity is not known. Male sperm storage during hibernation in male R. capensis coincides with low gonadotrope activity and low plasma LH and testosterone levels. Factors initiating gonadotrope activity and hence spermatogenesis are probably decreasing daylength (summer solstice) in M. schreibersii and increasing ambient temperatures and food abundance (following the hibernation period) in R.capensis.
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  • Date Issued: 1990

Religious experience and schizophrenia in modern man : an experiential theoretical study

  • Authors: Borchardt, Frederick Francois
  • Date: 1990
  • Subjects: Schizophrenia -- Religious aspects , Experience (Religion) -- Psychological aspects
  • Language: English
  • Type: text , Thesis , Masters , MA
  • Identifier: vital:2897 , http://hdl.handle.net/10962/d1002061
  • Description: In this study the psychological structures of two categories of religious and schizophrenic experience were examined from a phenomenological- existential perspective. Existing theories describe schizophrenia as an unfree, rigid experience with limited possibilities for selfhood. Some theorists believe, however, that some forms of schizophrenia can be seen as potential growth experiences which could facilitate existential renewal. These forms of schizophrenia are mystical, mythical or spiritual in nature. Religious experiences are, according to the literature, essentially renewal experiences facilitating existential growth and transformation through a particular system of thought and devotional relationship shared by a group of people. The Duquesne phenomenological- psychological method was used to analyse seven case studies, four of which involved schizophrenic experiences and three which involved religious conversion experiences. The general psychological structure which emerged through this analysis showed both schizophrenia and religious experience to have specific implications for the personal, social, material and mystical dimensions of being. The description of a specific psychological structure of experience which could optimally facilitate existential growth and transformation was attained by examining psychological structures where the subject's experience culminated in existential growth and transformation (such as religious experience and certain schizophrenIc experiences). As both these categories of experience displayed a strong mystical component, a psychological structure of experience which facilitates a transformative mystical experience was described. It can be concluded that an experience involving a mystical dimension could be transformative if the general psychological structure of the person displays (a) an openness towards reality as it presents itself (b) an experience of oneself as having a measure of existential freedom (c) a certain sense of security in one's own selfhood and (d) a social world which could understand, support and reflect inner experiences.
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  • Date Issued: 1990

Alternative mythical structures in the fiction of Patrick White

  • Authors: Bosman, Brenda Evadne
  • Date: 1990
  • Subjects: White, Patrick, 1912-1990 , White, Patrick, 1912-1990 -- Criticism and interpretation , Myth in literature
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:2170 , http://hdl.handle.net/10962/d1001821
  • Description: The texts in this study interrogate the dominant myths which have affected the constructs of identity and history in the white Australian socio-historical context. These myths are exposed by White as ideologically determined and as operating by processes of exclusion, repression and marginalisation. White challenges the autonomy of both European and Australian cultures, reveals the ideological complicity between them and adopts a critical approach to all Western cultural assumptions. As a post-colonial writer, White shares the need of both post-colonising and post-colonised groups for an identity established not in terms of the colonial power but in terms of themselves. As a dissident white male, he is a privileged member of the post- colonising group but one who rejects the dominant discourses as illegitimate and unlegitimating. He offers a re-writing of the myths underpinning colonial and post-colonising discourses which privileges their suppressed and repressed elements. His re-writings affect aboriginal men and women, white women and the 'privileged' white male whose subjection to social control is masked as unproblematic freedom. White's re-writing of myth enbraces the post-modern as well as the post- colonial. He not only deconstructs and demystifies the phallogocentric/ethnocentric order of things; he also attempts to avoid totalization by privileging indeterminacy, fragmentation, hybridization and those liminary states which defy articulation: the ecstatic, the abject, the unspeakable. He himself is denied authority in that his re-writings are presented as mere acts in the always provisional process of making interpretations. White acknowledges the problematics of both presentation and re-presentation - an unresolved tension between the post-colonial desire for self-definition and the post-modern decentring of all meaning and interpretation permeates his discourse. The close readings of the texts attempt, accordingly, to reflect varying oppositional strategies: those which seek to overturn hierarchies and expose power-relations and those which seek an idiom in which contemporary Australia may find its least distorted reflexion. Within this ideological context, the Lacanian thematics of the subject, and their re-writing by Kristeva, are linked with dialectical criticism in an attempt to reflect a strictly provisional process of (re) construction
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  • Date Issued: 1990

The idea of gaiety in Yeats's lyric poetry

  • Authors: Brady, Bronwyn
  • Date: 1990
  • Subjects: Yeats, W. B. (William Butler), 1865-1939 -- Criticism and interpretation , Lyric poetry -- History and criticism
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:2324 , http://hdl.handle.net/10962/d1015642
  • Description: In June 1917 W.B. Yeats wrote to his father : Much of your thought resembles mine . . but mine is part of a religious system more or less logically worked out, a system which will I hope interest you as a form of poetry. I find the setting it all in order has helped my verse, has given me a new framework and new patterns. (Wade 1954, 627) The new framework and new patterns that he claimed to have found in his system generated a new, and for Yeats, radically different sort of poetry. Before 1919 (The Wild Swans at Coole), the poetry had as its subject various traditional themes: the pity of love; the romance and heroism of Irish mythology; the threat of age, change and death. The poetry up to this point is, formally speaking, highly skillful, but locked into its own admissions of failure to touch or incorporate reality in any but a romantically defeatist way. However, the order which Yeats refers to in his letter, and the system he generated as a propaedeutic to this new order, once assimilated into the habit and texture of the poetry, generated new topics of its own which made those of the earlier work seem subjective, self- indulgent and intellectually uninformed. Yeats's poetry now changed drastically in focus and form, from subjective to objective poetry. Whereas the earlier poetry had opposed reality with romantic heroism or selfdestructive despondency, the poetry subsequent to his change of practice, incorporates a new vision of reality as the intrinsic architechtonics of poetry itself. Now the measure of human and aesthetic completion is no longer an inexplicable and inscrutable sadness, but an intelligent and informed detachment, an energy of mind that Yeats called "gaiety". My thesis explores this energy of mind and what it meant for Yeats and his poetry. My contention is that the idea of gaiety provides a way for Yeats to grant meaning to his life, a way for him to create himself. As the poetry is completed thanks to the new system, so is the poet. In order to see this, it is necessary to read the poems as a series of collections, or stories, that resonate back and forth with meaning and qualification and understanding. Yeats's system is his myth, and he writes his poetry in terms of and informed by that myth, shaping and re-shaping the experience of the created and fictional self until it has meaning in a way that the real self does not. The thesis explores this process of creation firstly in theoretical terms, using Lotman's ideas of Story and Myth, and looking at Yeats's intellectual and poetic inheritance. It goes on to examine some of the great poems in an attempt to define gaiety, and how Yeats achieves it in the poetry, and then to look at the early, pre-system poems to see how they differ. Finally, it takes the last of Yeats's lyric collections, Last Poems, and shows how gaiety works in the most mature poetry when the poems are read as narrative events within a story.
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  • Date Issued: 1990

A chemical investigation of Tulbaghia Violacea

  • Authors: Burton, Stephanie Gail
  • Date: 1990
  • Subjects: Liliaceae , Plants -- Analysis
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4528 , http://hdl.handle.net/10962/d1015725
  • Description: Tulbaghia violacea, a member of the family Alliaceae is indigenous to the Eastern Cape and is widely used as a herbal remedy for various febrile and gastro-enteric ailments, particularly in young children. Adverse effects, and even fatalities, have been reported following treatment with the plant extract. The project has involved synthesis of model compounds, chromatographic analysis of flavonoid and other constituents of the plant, and examination of the volatile components. Some fifteen flavones were synthesised as chromatographic models and in the course of this work, the development of a new method for synthesis of carboxylic anhydrides was completed. Use of the flavone standards permitted identification of the flavonols kaempferol and quercetin in hydrolysed glycosidic plant extracts. In addition, several sugars were identified, viz., D-glucose, D-fructose, L-arabinose and D-galactose as free sugars, and D-glucose, D-galactose , 1-rhamnose, D- fucose, D-xylose, 1-arabinose and D-fructose as glycosidic sugars, by g.l.c. and g. c. - m. s. analysis of derivatives of isolated sugar mixtures. The presence in the plant extracts of steroidal saponins was also demonstrated. The sulphur compounds, 2,4,5,7-tetrathiaoctane-2,2-dioxide and 2,4,5,7-tetrathiaoctane were isolated from the plant and characterised spectroscopically. This result, together with analysis of volatiles from the plant, has led to a proposal concerning the nature and origin of sulphur compounds in Tulbaghia violacea, showing close correlation with the sulphur compounds in Allium species. Investigation of the biological activity of Tulbaghia violacea extracts showed bacteriostatic activity, particularly of extracts which had not been heated, and which had been prepared from mature plants. Treatment of isolated smooth muscle preparations with Tulbaghia violacea extracts indicated the presence of a β-adrenergic agonist having an inhibitory effect on normal muscle contraction. The results of the investigations indicate that while there may be some basis for use of the plant as an antibacterial, or to treat colic, the adverse effects, caused possibly by the sulphur compounds and/or steroidal saponins present, may override the beneficial effects.
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  • Date Issued: 1990

A study of the effects of the pineal hormone, melatonin, on dopaminergic transmission in the central nervous system of rats

  • Authors: Burton, Susan Frances
  • Date: 1990
  • Subjects: Dopaminergic mechanisms Melatonin Pineal gland -- Secretions Neural transmission Pineal gland Nervous system
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:3726 , http://hdl.handle.net/10962/d1001463
  • Description: Dopamine mechanisms in the central nervous system are important in the control of both normal and abnormal motor function. The recent observations in both animal and human studies, that melatonin, the principal hormone of the pineal gland, may have a role in the control of movement and the pathophysiology of movement disorders, have given rise to the concept that melatonin may have a modulatory influence on central dopaminergic neurotransmission. This study makes use of three animal behavioural models as well as a biochemical model of central dopaminergic function to further investigate the concept. Results from studies using the biochemical model, which investigated the effect of melatonin on dopamine and apomorphine stimulation of dopamine-sensitive adenylate cylase, suggest that melatonin is neither a competitive antagonist nor agonist at the D₁ receptor level, although the possibility of physiological stimulation or antagonism is not excluded. In behavioural studies, prior melatonin mg/kg administration (1 and 10 (8M) ip) inhibited apomorphine induced stereotypy and locomotor activity in normal rats, and apomorphine-induced rotational behaviour in 6-hydroxydopamine and quinolinic acid lesioned rats. The possibility that these results may have physiological significance is borne out by the observation that, under enviromental lighting conditions that are associated with raised endogeous melatonin levels, apomorphine- induced stereotypy and locomotor activity is attenuated. The general conclusion is that melatonin has an inhibitory influence on central nervous system dopaminergic function, suggesting therefore, that the pineal gland and melatonin may have a role in the pathophysiology and treatment of movement and behavioural disorders associated with dopaminergic dysfunction
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  • Date Issued: 1990

Interrupt-generating active data objects

  • Authors: Clayton, Peter Graham
  • Date: 1990
  • Subjects: Parallel programming (Computer science) Electronic data processing -- Distributed processing
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:4677 , http://hdl.handle.net/10962/d1006700
  • Description: An investigation is presented into an interrupt-generating object model which is designed to reduce the effort of programming distributed memory multicomputer networks. The object model is aimed at the natural modelling of problem domains in which a number of concurrent entities interrupt one another as they lay claim to shared resources. The proposed computational model provides for the safe encapsulation of shared data, and incorporates inherent arbitration for simultaneous access to the data. It supplies a predicate triggering mechanism for use in conditional synchronization and as an alternative mechanism to polling. Linguistic support for the proposal requires a novel form of control structure which is able to interface sensibly with interrupt-generating active data objects. The thesis presents the proposal as an elemental language structure, with axiomatic guarantees which enforce safety properties and aid in program proving. The established theory of CSP is used to reason about the object model and its interface. An overview is presented of a programming language called HUL, whose semantics reflect the proposed computational model. Using the syntax of HUL, the application of the interrupt-generating active data object is illustrated. A range of standard concurrent problems is presented to demonstrate the properties of the interrupt-generating computational model. Furthermore, the thesis discusses implementation considerations which enable the model to be mapped precisely onto multicomputer networks, and which sustain the abstract programming level provided by the interrupt-generating active data object in the wider programming structures of HUL.
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  • Date Issued: 1990

"In ten years, maybe less", Chris McGregor about the establishment of democracy in South Africa

  • Authors: Combres, Joël
  • Date: 1990
  • Subjects: McGregor, Chris--1936-1990 , De Klerk, Frederik , Jazz , Jazz musicians , Blue Notes (Musical group : South Africa)
  • Language: French
  • Type: Article
  • Identifier: vital:13517 , http://hdl.handle.net/10962/d1006094 , McGregor, Chris--1936-1990 , De Klerk, Frederik , Jazz , Jazz musicians , Blue Notes (Musical group : South Africa)
  • Description: Photocopied article from the French newspaper Sud-Ouest about Chris McGregor's political opinions and hopes for South Africa. There are 2 pictures with the article. On top, Chris McGregor in his garden in France. The early Blue Notes Jazz Band is on the bottom picture.
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  • Date Issued: 1990

Initial findings of an investigation into the feasibility of a low level image processing workstation using transputers

  • Authors: Cooke, Nicholas Duncan
  • Date: 1990 , 2013-02-07
  • Subjects: Image processing , Computer graphics , Fourier transformations -- Data processing , Transputers
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4679 , http://hdl.handle.net/10962/d1006702 , Image processing , Computer graphics , Fourier transformations -- Data processing , Transputers
  • Description: From Introduction: The research concentrates primarily on a feasibility study involving the setting up of an image processing workstation. As broad as this statement concerning the workstation may seem, there are several factors limiting the extent of the research. This project is not concerned with the design and implementation of a fully-fledged image processing workstation. Rather, it concerns an initial feasibility study of such a workstation, centered on the theme image processing aided by the parallel processing paradigm. In looking at the hardware available for the project, in the context of an image processing environment, a large amount of initial investigation was required prior to that concerned with the transputer and parallel processing. Work was done on the capturing and displaying of images. This formed a vital part of the project. Furthermore, considering that a new architecture was being used as the work horse within a conventional host architecture, the INTEL 80286, several aspects of the host architecture had also to be investigated. These included the actual processing capabilities of the host, the capturing and storing of the images on the host, and most importantly, the interface between the host and the transputer [C0089]. Benchmarking was important in order for good conclusions to be drawn about the viability of the two types of hardware used, both individually and together. On the subject of the transputer as the workhorse, there were several areas whlch required investigation. Initial work had to cover the choice of network topology on whlch the benchmarking of some of the image processing applications were performed. Research into this was based on the previous work of several authors, whlch introduced features relevant to this investigation. The network used for this investigation was chosen to be generally applicable to a broad spectrum of applications in image processing. It was not chosen for its applicability for a single dedicated application, as has been the case for much of the past research performed in image processing [SAN88] [SCH89]. The concept of image processing techniques being implemented on the transputer required careful consideration in respect of what should be implemented. Image processing is not a new subject, and it encompasses a large spectrum of applications. The transputer, with image processing being hlghly suited to it, has attracted a good deal of research. It would not be rash to say that the easy research was covered first. The more trivial operations in image processing, requiring matrix type operations on the pixels attracted, the most coverage. Several researchers in the field of image processing on the transputer have broken the back of this set of problems. Conclusions regarding these operations on the transputer returned a fairly standard answer. An area of image processing which has not produced the same volume of return as that concerning the more trivial operations, is the subject of Fourier Analysis, that is, the Fourier Transform. Thus a major part of this project concerns an investigation into the Fourier Transform in image processing, in particular the Fast Fourier Transform. The network chosen for thls research has placed some constraint upon the degree of parallelism that can be achleved. It should be emphasized that this project is not concerned with the most efficient implementation of a specific image processing algorithm on a dedicated topology. Rather, it looks at the feasibility of a general system in the domain of image processing, concerned with a hlghly computationally intensive operation. This has had the effect of testing the processing power of the hardware used, and contributing a widely applicable parallel algorithm for use in Fourier Analysis. 3 These are discussed more fully in Chapter 2, which covers the work related to tbis project. The results of the investigation are presented along with a discussion of the methods throughout the thesis. The final chapter summarizes the findings of the research, assesses the value of the investigation, and points out areas for future investigation.
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  • Date Issued: 1990

The National minimum wage reader

  • Authors: COSATU
  • Date: 1990
  • Subjects: COSATU
  • Language: English
  • Type: text
  • Identifier: http://hdl.handle.net/10962/173584 , vital:42386
  • Description: Low wages are a cause of poverty. They are unjust and they lead to economic inefficiency. Low pay is not the result of "market forces" or of individual productivity. It is the result of the vulnerability of certain sectors of the workforce and the cost structure of low-wage industries. A National Minimum Wage is a practical solution that has been adopted in many countries. It is one of the demands of the Freedom Charter. The National Minimum Wage can be developed by COSATU as a powerful campaign tool in the fight for a living wage . The National Campaigns Conference, held in May 1990, asked the Living Wage Working Croup "to establish what National Minimum Wage should be suggested to develop a program of action to achieve a National Minimum Wage". The conference agreed that the level of the National Minimum Wage will be decided at the second National Campaigns Conference in August 1990. This reader pulls together all the documents and resolutions that have guided the Living Wage Working Group in its work on the National Minimum Wage.
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  • Date Issued: 1990

COSATU Regional education programme

  • Authors: COSATU
  • Date: 1990
  • Subjects: COSATU
  • Language: English
  • Type: text
  • Identifier: http://hdl.handle.net/10962/154403 , vital:39695
  • Description: This document should be used by ail of us involved in Education as a basis for discussion on organising education in the Federation. We have pulled together all the relevant information and reccommen- dations which we hope will assist Led- comm, Educators and our constitutional structures in understanding what our tasks are in the locals and in affiliates. The Redcomm agreed that an Education Programme must go beyond being just a number of workshops and seminars. It must be a dynamic process which must contribute to the strengthening of our structures, improving the quality of our debates and promoting leadership of the working class in our struggle for democracy.
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  • Date Issued: 1990

The taxonomy and life history of the blue stingray, Dasyatis marmorata capensis (Batoidea : Dasyatidae) from Southern Africa

  • Authors: Cowley, Paul D (Paul Denfer), 1964-
  • Date: 1990
  • Subjects: Stingrays -- Africa, Southern Dasyatidae
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5183 , http://hdl.handle.net/10962/d1001959
  • Description: The blue stingray, Dasyatis marmorata capensis is an important recreational shore angling species, especially amongst tournament anglers, in South Africa. The taxonomy and aspects of the biology of this species were investigated from specimens collected between March 1987 and May 1989, from various localities along the southern African coastline. Morphological comparisons were made between Dasyatis pastinaca, Dasyatis marmorata and the local variety. The results indicated that the local variety is different to D. pastinaca in colouration, disc length size, and vertebral and radial counts. The proposed new sub-species Dasyatis marmorata capensis is closest to Dasyatis marmorata of the north-eastern Atlantic coast, but differs in snout angle, disc length and snout to vent length. Analysis of catch per unit of effort data revealed that the blue stingray exhibits distinct seasonality. Adult and sub-adult fish undertake an annual onshore/offshore migration and invade the inshore region between spring and summer, while juveniles remain offshore and utilize this zone as a nursery area. Length-at-age and growth rates for both sexes were estimated from bands formed seasonally in the vertebral centra. The derived von Bertalanffy growth parameters indicated that females reach a greater asymptotic size (913.8 mm DW) and have a slower growth rate (K = -0.07) than males (531.8 mm DW, K = -0.17). Growth rates of juvenile captive specimens compared favourably with back calculated values, at approximately 65 mm/year, for the first year of growth. Dasyatis marmorata capensis is an aplacental viviparous elasmobranch with a well defined annual breeding cycle. Young are released , at a size of 170-200 mm DW, from October to December after a gestation period of approximately nine months. An average fecundity of 3.07 was calculated . Examination of gonadal development indicated that sexual maturity is first attained at a size of 408 and 500 mm DW in males and females, respectively, corresponding to ages 4.5 and 7 years. Size-related food habits were determined independently from three depth zones. The major prey items for each size class were directly related to the abundance of the infauna of the different depth zones. Polychaeta, amphipoda and stomatopoda were the major prey items in the offshore zone. In the nearshore zone, the dominant prey species were Balanoglossus capensis and Callianassa spp .. The high incidence of empty stomachs and the presence of prey items which occur in greatest abundance beyond the surf zone indicated that this zone is not utilized for the purposes of feeding.
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  • Date Issued: 1990

Enrichment strategies for gifted English first language (HG) pupils at the senior secondary level : a critical evaluation of a programme implemented at Grey Boys' High School, Port Elizabeth, 1986-1988

  • Authors: Cunningham, Gregory Mark
  • Date: 1990
  • Subjects: English language -- Study and teaching (Secondary) -- South Africa -- Eastern Cape Gifted children -- Education (Secondary) -- South Africa -- Eastern Cape Gifted children -- Education -- Research
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:1510 , http://hdl.handle.net/10962/d1003392
  • Description: Programmes developed specifically for the gifted and talented pupil are not a novel idea. Yet, by comparison, the history of gifted education is a brief one. Highly gifted and talented pupils often have difficulty being challenged in a conventional classroom situation. Since classroom instruction is usually designed for the benefit of pupils who function at the level of the majority of their peer age-group, this teaching, no matter how well done, may not be appropriate for the extremely gifted pupil whose abilities differ greatly from this group. Even special programmes for gifted and talented students may be designed for a broad group of gifted students and may not meet the specific needs of the gifted child, especially ones with a special intellectual talent. While it is important to bear aspects such as the characteristics of giftedness and the attributes of the talented individual in mind, the basis of this dissertation examines what enrichment and acceleration strategies may be utilised by the English First Language (HG) teacher when presented with a preselected group of pupils who are gifted in English, utilising a composite gifted educational model as a mechanism for the development of this specific programme.
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  • Date Issued: 1990

ICEF Energy conference

  • Authors: CWIU
  • Date: 1990
  • Subjects: CWIU
  • Language: English
  • Type: text
  • Identifier: http://hdl.handle.net/10962/152450 , vital:39279
  • Description: The decline in world energy consumption caused by the twin oil price hikes of 1973 and 1979 checked development in the major market economies and triggered the process of industrial restructuring that has so profoundly affected all sectors and all regions. ore efficient use of more expensive energy and strategic policy changes have made major contributions to easing the historical reliance upon energy inputs - especially in the case of oil. As a result the ratio between energy consumption and growth of gross world production has diminished by nearly 25 % over the past fifteen years. It has been estimated that full use of available energy-efficient technologies could cut per capita energy use by as much as 50% without impeding economic growth. The extent to which these gains are realized will depend upon a wide variety of economic and developmental factors, among which the price management of fuels is a very important one. here has also been a change in the industrial mix of the major OECD economies with the decline of old industries using high energy imputs and the rise of high technology sectors with different and lower energy requirements. The shift of much basic manufacturing to new locations in the developing world and to the hitherto centrally planned economies is likely to precipitate a further important change in energy requirements. emand for energy is forecast to continue to grow at only about half the rate of general economic growth over the short to medium term. Consumption is very uneven on a world scale, however. In 1988 the world consumed energy equivalent to some 8 billion tonnes of oil (Tonnes Oil Equivalent, or TOE) - an average of 1.3 tonnes for every man, woman and child on Earth. While citizens of the USA will consume an average of 8 TOE per capita, however, the average for both Japan and Western Europe is around 3 TOE, while people in the Third World still rely on fuelwood and dried animal dung as important energy resources, consuming only a small fraction of a TOE each in many cases.
  • Full Text:
  • Date Issued: 1990

Fest-Quest '89: a survey of visitors to the 1989 Standard Bank Arts Festival

  • Authors: Davies, William J
  • Date: 1990
  • Subjects: Standard Bank National Arts Festival Art festivals -- South Africa Performing arts -- South Africa Art and society -- South Africa
  • Language: English
  • Type: Book , Text
  • Identifier: http://hdl.handle.net/10962/1730 , vital:20220 , ISBN 0868101990
  • Description: The Standard Bank National Arts Festival is an annual event which invades the City of Grahamstown in early July. Over the years, it has become an important national cultural showcase of theatre, dance, music, and fine art. It also attracts a wide variety of handicraft and hone industry vendors, which together with other peripheral activities, transforms the City into a bustling place imbued with a festive atmosphere. Apart from its cultural significance, the Festival means a great deal to the local economy because it attracts visitors from all over the country who spend several million rand whilst they are in Grahamstown. The Development Studies Unit at Rhodes University and the 1820 Foundation have monitored the nature and extent of the festival's impact on Grahamstown since 1987. Information is collected by means of a voluntary questionnaire (the Fest-Quest) which provides a useful resource for the Festival organisers as well as insights into the relative economic importance of the occasion. , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
  • Full Text:
  • Date Issued: 1990

Community-based co-operative ventures in Port Elizabeth

1820 Foundation publications: an evaluation for the 1820 Foundation

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