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Cumulative mild head injury in rugby: a comparison of cognitive deficit and postconcussive symptomatology between schoolboy rugby players and non-contact sport controls

  • Authors: Beilinsohn, Taryn
  • Date: 2001
  • Subjects: Rugby football injuries , Head -- Wounds and injuries -- Psychology , Head -- Wounds and injuries -- Complications , Brain damage
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:2931 , http://hdl.handle.net/10962/d1002440 , Rugby football injuries , Head -- Wounds and injuries -- Psychology , Head -- Wounds and injuries -- Complications , Brain damage
  • Description: This study investigates the cumulative effects of concussive and subconcussive mild head injury on the cognitive functioning of schoolboy rugby players. A comprehensive battery of neuropsychological tests and a self-report postconcussive questionnaire were administered to top level schoolboy rugby players (n=47), and a non-contact sport control group of top level schoolboy hockey players (n=34). Group comparisons of the percentage of individuals with cognitive deficit were carried out between i) the schoolboy rugby and the schoolboy hockey players, ii) the rugby forward and the rugby backline players; iii) the rugby forward and the schoolboy hockey players and, iv) the rugby backline and the schoolboy hockey players. Results on the neuropsychological test battery did not provide any substantial evidence of a higher level of neuropsychological impairment in the rugby players relative to the control group, or in the rugby forward players relative to the rugby backline players. Results obtained on the postconcussive symptom questionnaire provided tentative indications that the rugby players do report a greater frequency of postconcussive symptomatology. The symptoms most frequently reported were being easily angered, memory problems, clumsy speech and sleep difficulties. It was hypothesized that the absence of cognitive impairment in the schoolboy rugby players compared with that noted for professional players was due to their younger age, relatively high IQ and education level and a less intensive level of physical participation in the sport, and hence less accumulated exposure to the game, thereby decreasing their exposure to mild head injuries. From a theoretical perspective, these pre-existing conditions were considered to act as protective factors against reductions in brain reserve capacity and concomitant susceptibility to the onset of neuropsychological dysfunction.
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Deconstructing the Transvaal Supergroup, South Africa: implications for Palaeoproterozoic palaeoclimate models

  • Authors: Moore, John M , Tsikos, Harilaos , Polteau, S
  • Date: 2001
  • Language: English
  • Type: Article
  • Identifier: vital:6078 , http://hdl.handle.net/10962/d1006122
  • Description: Current correlations between the Pretoria and Postmasburg Groups of the Transvaal Supergroup are shown to be invalid. The Postmasburg Group is also demonstrated to be broadly conformable with the underlying Ghaap Group and therefore considerably older (~2.4 Ga) than previously supposed. The new stratigraphy documents an extensive (100 Ma) and continuous cold-climate episode with a glacial maximum at the Makganyene Formation diamictite. Iron formations of the underlying Asbesheuwels and Koegas Subgroups and overlying Hotazel Formation have similar origins, related, respectively, to the onset and cessation of the glacial event. This interpretation of the Transvaal Supergroup stratigraphy has significant implications for various Palaeoproterozoic environmental models and for the timing of the development of an oxygenated atmosphere.
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Design and positioning of controls : the old and the new industrial approaches

  • Authors: Dirkse van Schalkwyk, C J
  • Date: 2001
  • Language: English
  • Type: Article
  • Identifier: vital:6750 , http://hdl.handle.net/10962/d1009330
  • Description: While copious amounts of research exist with regard to positioning of controls, very little research covers the design shape of the controls. This paper demonstrates the importance of control positioning and design within industrial settings. Furthermore it aims to highlight the changes in industries with regard to control design and positioning. This paper is a review paper and thus much is based on findings by other authors. However, the changes in the industrial practices referred to by the author are from knowledge gained while visiting numerous industries in South Africa.
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Design, synthesis and characterization of novel rhenium(V) and technetium(V) complexes as potential radiopharmaceuticals

  • Authors: Hlabela, Patrick Simon
  • Date: 2001
  • Subjects: Radiopharmaceuticals , Rhenium , Technetium
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4306 , http://hdl.handle.net/10962/d1004964 , Radiopharmaceuticals , Rhenium , Technetium
  • Description: A number of bidentate N, N-diethyl-N' -(R ')benzoylthiourea ligands (where R' = H,CH₃,CI,OCH₃ and N0₂) have been synthesized, as well as the three Re(V) precursor complexes, ReOCl₃(PPh₃)₂,[ReO₂(py)₄]CI and [n-Bu₄N] [ReOCI₄J. The reaction of N,N-diethyl-N'-benzoylthiourea (LH) with these three metal precursor complexes in methanol in the presence of a base gave a novel mixed-ligand complex bis(N,N-diethyl-N'-benzoylthioureato)methoxyoxorhenium(V), [ReO(L)₂(OMe)] (1). In the absence of a base and under an inert atmosphere, the reaction between [n-Bu₄N][ReOCI₄] and LH yielded bis(N,N-diethyl-N'-benzoylthioureato)chlorooxorhenium(V), [ReO(L)₂CI] (lb). The reaction of LH with [ReO₂(py)₄]CI in ethanol and iso-propanol in the presence of sodium acetate gave the novel mixed ligand complexes bis(N,N-diethyl-N'benzoylthioureato) ethoxyoxorhenium(V), [ReO(L)₂(OEt)] (6) and bis(N,N-diethyl-N'benzoylthioureato)(iso-propoxy)oxorhenium(V), [ReO(L)₂(OiPr)] (7), respectively. An oxygen bridged dirhenium complex, [(L)₂0Re-O-ReO(L)₂] (15) was obtained when the reaction was carried out in acetonitrile. A series of mixed ligand Re(V)-oxo complexes using N, N-diethyl-Nʾ-(R' )benzoylthiourea (LR'),N,N-morpholino-N' -(R')benzoylthiourea (morph-LR') and 8-(N-(R')benzoylthiocarbamoyl)-1,4-dioxa-8-azaspiro[4.5]decane ligands (spiro-LR') (where R' = H,CH₃,CI, OCH₃ and N0₂) ((1)(14) have been prepared by the reaction of [ReO₂(py)₄]CI and the ligand in the presence of sodium acetate in methanol. The solution state chemistry of these complexes has shown that complexes(1)-(14) (with the exception of (1b)) undergo dimerization in solution to give complex (15) in the presence of water. Preliminary ¹H NMR kinetics studies of the dimerization of (1), (6) and (7) to (15) have shown that the rate of dimerization decreases in the order (7) > (6) > (1). The rate of dimerization has also been compared for complexes (1), [ReO(morph-L)₂(OMe)] (8) and [ReO(spiro-L)₂(OMe)] (13) and the rate of dimerization was found to be fastest for (13). The crystal structures of (1), [ReO(LN0₂)₂(OMe)] (4), (6) and (15) have been determined. The Re(V)-oxo complexes (1), (4) and (6) have a slightly distorted octahedral geometry with the two acylthiourea ligands binding in a cis arrangement in the equatorial plane of the octahedron. The alkoxy and oxo ligands occupy the axial positions and are situated trans to each other. The crystal and molecular structure of complex (15), consist of two slightly distorted octahedral [ReO(L)₂] moieties bridged by an oxygen atom with a Re-O-Re bond angle of 175.2(2)°. The preliminary studies done in the present study have indicated that the complexation chemistry of technetium(V) with the N,N-diethyl-benzoylthiourea is different to that of rhenium (V). The reaction between [n-BuN₄][TcOCl₄] and N,N-diethyl-N'-benzoylthiourea yielded the square pyramidal cationic complex [TcO(L)₂]Cl. By contrast the octahedral methoxy complex [ReO(L )₂( OMe)] was obtained when the analogous Re(V)-oxo precursor, [n-Bu₄N] [ReOCI₄], was reacted with N,N-diethyl-N'-benzoylthiourea under the same reaction conditions.
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Design, synthesis and evaluation of silver-specific ligands

  • Authors: Daubinet, André
  • Date: 2001
  • Subjects: Ligands Ligands -- Design Ligands -- Analysis Ligands -- Evaluation Silver -- Metallurgy
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:4308 , http://hdl.handle.net/10962/d1004966
  • Description: Several series of ligands, designed to chelate silver(I) specifically in the presence of base metals, have been synthesised. The ligands include: - dithiodiamide compounds, prepared by the condensation of acetanilide derivatives with 1,2-dibromoethane; propanenitrile and propanoic ester derivatives prepared from pyridine-2-carbaldehyde via the Morita-Baylis-Hillman reaction; and novel malonamide ligands from the reaction of diethyl malonate with a range of primary amines. The malonamide derivatives were prepared under both conventional thermal and microwave-assisted conditions, the latter proving to be highly efficient. The ligands were all characterised using a combination of spectroscopic and, where appropriate, elemental analysis; in one case, the structural assignment was confirmed by single-crystal X-ray analysis. The fragmentation patterns in the electron-impact mass spectra of the malonamide derivatives have been explored using high-resolution and meta-stable peak scanning techniques. Complexes of the malonamide ligands with copper(II) and silver(I) have been synthesised, and examination of these complexes has revealed distinct differences in their co-ordination preferences towards silver(I) and copper(II). Tentative, computer-modelled structures for the complexes have been proposed using the available spectroscopic and elemental analysis data. Computer modelling, at the Molecular Mechanics level, has also been used to assess the capacity of the ligand systems to adopt conformations suitable for the chelation of tetrahedral silver(I). Solvent extraction studies have been undertaken using aqueous metal ion solutions and various organic solvents. The dithiodiamide derivatives typically presented solubility problems, but one of the ligands, N,N´-bis(3-chlorophenyl)-3,6-dithiaoctanediamide, exhibited significant but slow extraction of silver(I) into toluene. The malonamide derivatives, however, proved to be readily soluble in ethyl acetate and, in some cases, exhibited good to excellent selectivity for silver(I) in the presence of the base metals copper and lead. Atomic absorption analysis revealed rapid equilibration times (<15 min) and high extraction efficiencies over a wide pH range (2.78 - 9.0). Metal selectivity has been determined by ICP-MS analysis of the residual silver, copper and lead present in the aqueous phase after 15 min, and one of the ligands, N,N´-bis(2-benzylsulfanylethyl)malonamide, exhibits excellent (≥ 96 %) silver(I) specificity.
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Ecology and breeding biology of Lanner Falcons in the Eastern Cape Province, South Africa

  • Authors: Stephenson, Alan
  • Date: 2001
  • Subjects: Birds -- Breeding , Birds -- South Africa -- Eastern Cape , Birds -- Ecology , Falcons -- South Africa -- Eastern Cape
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5667 , http://hdl.handle.net/10962/d1005352 , Birds -- Breeding , Birds -- South Africa -- Eastern Cape , Birds -- Ecology , Falcons -- South Africa -- Eastern Cape
  • Description: Lanner Falcons Falco biarmicus are the commonest large falcons in Africa and this study in the coastal area of the Eastern Cape Province, South Africa investigated their ecology from 1984 to 2000. Lanners have recently been categorised as near-threatened and this study was initiated to ascertain if the population was stable. Breeding success of a small population, in different habitat types, was monitored intensively from 1997 to 2000, and the factors that inhibited breeding were investigated. The earliest onset of incubation was 17 July and the latest 16 August, with 2.2 young fledged per breeding pair over the four-year period. Incubation lasted 32 days and young fledged after 42-45 days. All nest sites were on cliffs with a mean height of 114 m, a mean vertical face of 53 m; 45% of the nests were in ravens’ nests. The aspect of cliff sites also influenced breeding success. Radio tracking was used to determine home range, habitat use and hunting methods, with prey species identified. Home ranges were between 66 km² and 249 km². Preferred prey was domestic chickens, pigeons and small birds during the breeding season. Foraging ranges were smaller in intensively cultivated areas with seed crops. Data obtained from ringing returns showed that no long distance movements occurred in this region, but two juveniles dispersed 152 km and 127 km. Conservation aspects with possible threats to Lanner Falcons such as poisons, electrocutions and direct persecution are discussed with some recommendations made for future research. Evidence from this study indicates that Lanner breeding success is not limited by nest site availability, but by rainfall timing and prey availability. Lanners foraged more in open areas than areas with tall vegetation, and benefited from intensive agriculture. This population appeared to be healthy and in no danger of declining in the near future.
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Economic review 2001

  • Authors: DITSELA
  • Date: 2001
  • Subjects: Development Institute for Training,Support and Education for Labour (DITSELA)
  • Language: English
  • Type: text
  • Identifier: http://hdl.handle.net/10962/178602 , vital:42958
  • Description: This volume of Bargaining Indicators for 2002 comes in the context of the September 11 attacks on the World Trade Center in New York, the United States’ war on Afghanistan, the collapse of the economy of Argentina and with it the biggest sovereign bankruptcy in history. All these historic events are unfolding within the first synchronised global recession since the 1970s, and have in turn deepened this recession. Within South Africa, this edition of Bargaining Indicators comes in the context of the first anti-government national strike by organised labour since the 1994 elections, and a deepening of the economic slowdown that we noted in the last edition of Bargaining Indicators. In this review of economic developments during 2001 we shine the spotlight on the global recession and its dynamics, and we look in particular at the slide of the world’s largest economy - that of the United States - into its first serious economic crisis since the end of the cold war, and we take a look at the significance of the attacks of September 11 and their aftermath on the dynamics of the global recession. We conclude our discussion of the global recession by discussing the responses of the Bush government and its allies, and at the meaning of these responses for neoliberal economic orthodoxy. We continue our analysis by looking at developments within the South African economy. In particular, we look at the implications of the global recession on the South African economy, and at how the currency crisis that has unfolded since the last quarter of 2001 forms an important moment in the dynamics of the unfolding global recession. Within this context we look at the main economic indicators (GDP; GDE; fixed capital formation, operating surpluses, wages, employment, savings and so on). Lastly, we look at the year ahead, and in particular at the implications of the global and domestic economic developments for the 2002 bargaining season.
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Effect of feeding regimen, temperature and stocking density on growth and survival of juvenile clownfish (Amphiprion percula)

  • Authors: Johnston, Gavin
  • Date: 2001
  • Subjects: Anemonefishes , Fishes -- Feeding and feeds , Fishes -- Growth
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5274 , http://hdl.handle.net/10962/d1005118 , Anemonefishes , Fishes -- Feeding and feeds , Fishes -- Growth
  • Description: In aquaculture, a thorough knowledge of the specific environmental requirements of a species is needed in order to maximize growth rate and survival. There is a paucity of data regarding the fundamental environmental requirements for the ongrowing phase of clownfish juveniles. This prompted the design of three experiments to determine the best feeding regimen, temperature and stocking density that maximize growth and survival of Amphiprion percula. Ration size and feeding frequency are important factors for optimizing fish growth during the juvenile grow-out phase. A factorial growth trial was conducted to determine the effect of feeding frequency and ration size on the growth of juvenile clownfish (Amphiprion percula).Three feeding frequencies (1, 2 and 3 times daily) and six rations (2,4,6,8, 10 and 12 % body weight per day (BW.day⁻¹)) were used to test the growth response over a twelve week period. Non-linear regression analysis on the effect of ration, independent of feeding frequency, on growth resulted in a significant (n = 36; r² = 68.7) parabolic model: In y = -0.0302x² + 0.5159x + -4.4377. Maximum growth corresponded to a ration of 8.5% BW.day⁻¹. Survival as a function of ration was significantly lower at 2% BW.day⁻¹. Data were further examined with Analysis of CoVariance (ANCOVA) to determine the effect of ration on growth at each feeding frequency. The combination revealed a maximum growth rate when the fish were fed a ration of 10% BW.day⁻¹ divided into two equal meals. The required ration per meal to maintain maximum growth was also found to decrease as feeding frequency increased. The determination of the best temperature for growth is of great importance due to the direct relationship between fish metabolism and temperature. The thermal preferendum of A. percula has already been estimated at 26 ± 0.7°C but it is not known whether this closely approximates the temperature for maximum growth. Sixteen tanks were set to different temperatures ranging between 21.5 and 30.2 °C. Ten juvenile A. percula were placed in each tank and growth was measured fortnightly over the course of the 10 week experiment. Non-linear regression analysis resulted in significant models for fish length (y = -0.0005x² + 0.00267x - 0.0338; r² = 56.7, n = 11) and weight (y= -0.00016x² + 0.0084x - 0.1073; r² = 61.6, n = 11). These models predict that maximum growth would be at 27.7 and 27.1 °C for length and weight, respectively. Temperature, over the range tested, had no apparent effect on survival. There was no significant difference between the temperatures for maximum growth and the preferred temperature. The effect of stocking densities ranging from 0.2 fish.L¹ to 4.0 fish.L⁻¹ on growth were used in the third experiment. The fish were fed to satiation twice daily and growth was measured fortnightly throughout the 8 week experiment. No effects on growth, survival or coefficient of variation were found within the range of stocking densities tested.
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Effect of oligomerization on the photochemical properties of silicon octaphenoxyphthalocyanine

  • Authors: Maree, M David , Nyokong, Tebello
  • Date: 2001
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/291542 , vital:56885 , xlink:href="https://doi.org/10.1016/S1010-6030(01)00485-3"
  • Description: The photochemical properties of silicon octaphenoxyphthalocyanines (SiOPPc) oligomerized were studied in dimethylsulfoxide (DMSO) solutions. Oligomers containing 2–5 and 9 SiOPPc rings linked with terephthalate linkages were synthesized. Singlet oxygen quantum yields were found to be in the range 0.11–0.34, and increased with the number of rings up to five rings, a decrease in the quantum yield was observed for nine rings. This is explained in terms of the high aggregation of the oligomer containing nine rings.
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Electrooxidation of cresols on carbon electrodes modified with phthalocyaninato and octabutoxyphthalocyaninato cobalt (II) complexes

  • Authors: Grootboom, Natasha , Nyokong, Tebello
  • Date: 2001
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/293207 , vital:57065 , xlink:href="https://doi.org/10.1016/S0003-2670(00)01351-9"
  • Description: Glassy carbon electrodes (GCE) modified with cobalt(II) phthalocyanine (CoPc-GCE) and cobalt(II) octabutoxyphthalocyanine (CoOBuPc-GCE) were employed for the electrochemical analysis of ortho-, meta-, and para-cresols. The oxidation potential of p-cresol was shifted towards less positive values to a larger extent, when compared to m- and o-cresols, on CoOBuPc-GCE. However, the GCE was less stable when modified with CoOBuPc than with CoPc. This is explained using the possible differences in the orientation of the adsorbed phthalocyanine molecules on the electrode. Bulk electrolysis of p-cresol at anodic potentials (1.0 V versus Ag|AgCl) on carbon electrodes modified with CoPc resulted in the formation of radicals which coupled to form trimeric products. On unmodified carbon electrodes, coupling of the radicals resulted in dimeric products following bulk electrolysis. The products formed following bulk electrolysis were characterized by liquid chromatography coupled with mass spectrometry.
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Elements of dream interpretation: laying the foundation of a basic model for clinical practice

  • Authors: Schön, Joan
  • Date: 2001
  • Subjects: Dream interpretation Dreams
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:3050 , http://hdl.handle.net/10962/d1002559
  • Description: The study addresses certain paradoxes evident in the theory and practice of dream interpretation. These relate to the considerable value afforded to dreams in psychoanalytic thinking, compared with (1) the surprising dearth of literature, research, and training on dream interpretation in clinical practice, (2) the difficulties voiced by clinicians regarding dream interpretation, and (3) the diversity of keys employed by different schools to unlock the ‘truth’ of dreams. The intention of the study is to examine these paradoxes in order to develop a model fordream interpretation which falls within the ambit of psychodynamic psychotherapy. It is argued that there have been few insights over the century to match the seminal work of Freud (1900/1976), except perhaps the work of Carl Jung. As a result of the 1914 rift between these two, Jung’s insights have been largely ignored in mainstream psychoanalytic thinking and the focus on dreams has given way to other areas of development, such as, unconscious thinking, symbol formation, and interpretation in a general sense. These, it is argued, have contributed to a more comprehensive understanding of dreams and their interpretation. Thus a model would need to consider both Freud and Jung’s work, and later salient developments. It would also need to be informed by local, contemporary practice. The method used in this thesis is one of breaking down the process of dream interpretation into component parts, in order to examine useful contributions from different sources and to compare work with dreams to work with other material. The literature review examines the major theoretical contributions in relation to four elements of dreams interpretation: the nature and function of dreams, methods of dream interpretation, the meaning of dreams, and the goals of dream interpretation. A model which accommodates diverse theories without resorting to eclecticism is then proposed. Dream interpretation is further examined in the light of a multiphase clinical study, designed to provide different perspectives on the topic. The study yielded findingscompatible with the literature reviewed, as well as certain problems in relation to the proposed model. These included shortcomings of the elements used in the literature review, particularly the sequence of these elements, and caveats about affording dreams a special focus in the consulting room. Thus a second configuration was posited, namely the idea of viewing dream-work as a triangular situation, comprising the dream, the dreamer, and the dream interpreter. The final model which is the outcome of the study provides two interrelated methods of addressing dream interpretation which accommodate the theory/practice dichotomy. In the first, the elements of dreams and their interpretation are considered sequentially. This method provides a framework for considering theoretical contributions on dreams, as well as issues of technique, without recourse to the introduction of theory in the consulting room. In the second, dream interpretation is regarded as a triangular situation, comprising the interchange between therapist and patient in relation to the patient’s dream-life. This structure accommodates the alliance which is discernible in practice and draws on Segal’s (1957/1986) notion that the process of symbol formation is a triangular situation. The value of regarding ‘dream-work’ in the consulting room as a triangular situation is threefold: (1) it is akin to symbol formation in terms of the meaning reached; (2) dreams cannot be accurately interpreted in isolation from the contributions of both therapist and patient; and (3) it provides ‘dream-work’ in practice with its own structure, highlighting a perspective that dreams are an element of clinical practice, rather than a focus, a subtext within the broader framework of psychodynamic psychotherapy.
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Enhancing military efficiency : a South African perspective

  • Authors: Christie, Candice J , Todd, Andrew I
  • Date: 2001
  • Language: English
  • Type: Article
  • Identifier: vital:6749 , http://hdl.handle.net/10962/d1009329
  • Description: While extensive military research has been conducted in developed countries, very little work has been done on soldiers in industrially developing countries (IDCs). Although many aspects of marching are similar around the globe, the challenges facing soldiers in IDCs, and in particular South Africa, are unique. Since the 1990’s South Africa has seen a considerable shift in the morphological and cultural make-up of the South African National Defence Force (SANDF). The result is a mix of soldiers from a variety of ethnic backgrounds. Ethnic differences may ultimately impact performance particularly as research has postulated that Blacks and Whites may differ in body composition and body proportions. It is highly probable then that the universal recommendations of optimal marching speeds, load masses and gradients need to be modified to accommodate the diversity of soldiers which currently comprise the SANDF.
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Environment as integrating organiser: a case study of curriculum 2005 in KwaMhlanga, South Africa

  • Authors: Khumalo, Four-Ten Enock
  • Date: 2001
  • Subjects: Competency-based education -- Research -- South Africa Curriculum planning -- South Africa Environmental education -- Curricula -- South Africa -- Mpumalanga Environmental education -- Curricula
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:1511 , http://hdl.handle.net/10962/d1003393
  • Description: Curriculum 2005 is an attempt by the South African government to create and implement a strategic plan to change the formal school curriculum. The new curriculum has 'integration' as one of its focal features. This study is an investigation of the use of' environment' as an integrating' organiser' in the senior phase of Curriculum 2005 in a selection of schools in the Mpumalanga province. While the Curriculum 2005 framework encourages curriculum integration, this is an area which might be neglected during implementation, because there is so little experience among teachers of working in an 'integrated' way. Environmental education is an approach to education which requires and facilitates curriculum integration. This study has the potential to contribute to our understanding of the integration of environmental learning across the new curriculum. Questionnaires and vignettes based on document analysis, follow-up interviews and classroom observations, involving a small group of teachers, were used in conducting the study. The investigation has revealed that participating teachers show a limited understanding of the constructs 'environment' and 'phase organiser'. Teachers do not take or introduce a critical perspective on the nature and causes of environmental issues. They treat the construct 'environment' and associated issues quite superficially when working with learners. Participating teachers generally misunderstood the concept 'phase organisers' and tended to interpret it in concepts associated with the curriculum framework they were used to. Curriculum 2005 also requires teachers to take on a more active curriculum development role. This study looked at four teachers' attempts to develop learning programme units, and at the way in which two teachers implement their curriculum plans focussing on 'environment', in the classroom. It was found that participating teachers do not always follow the same sequence or steps when developing a learning programme. Learning programme units were not considered in developmental sequence, they lacked some form of continuity and links between intended learning outcomes and teaching activities were also lacking. There was inadequate integration between learning areas. Furthermore, integration between knowledge, skills, values and attitudes was also not quite clear among the teachers, and they tended to deal with environmental knowledge in a rather limited way, focussing instead on the awareness and attitudes. These findings are of concern, and they are in keeping with the Curriculum 2005 Review Report, which highlighted the danger of inadequate focus on curriculum content. On overall teachers seem to be struggling with the whole notion of 'integration', even though environment as a phase organiser is meant to assist with curriculum integration. The thesis ends with recommendations on how teachers might be assisted to achieve meaningful curriculum integration, through using learning outcomes as well as content knowledge relevant to environmental learning.
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Enzymology of activated sewage sludge during anaerobic treatment of wastewaters : identification, characterisation, isolation and partial purification of proteases

  • Authors: Tshivhunge, Azwiedziswi Sylvia
  • Date: 2001
  • Subjects: Sewage sludge , Sewage sludge -- Environmental aspects , Sewage sludge digestion , Anaerobic bacteria
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4012 , http://hdl.handle.net/10962/d1004072 , Sewage sludge , Sewage sludge -- Environmental aspects , Sewage sludge digestion , Anaerobic bacteria
  • Description: During anaerobic digestion bacteria inside the digester require a carbon source for their growth and metabolism, sewage sludge was used as a carbon source in this study. The COD content was used to measure the disappearance of the substrate. COD content was reduced by 48.3% and 49% in the methanogenic and sulphidogenic bioreactors, respectively, while sulphate concentration was reduced by 40%, producing 70mg/L of hydrogen sulphide as the end product over the first 5-7 days. Sulphate (which is used as a terminal electron acceptor of sulphur reducing bacteria) has little or no effect on the sulphidogenic and methanogenic proteases. Sulphite and sulphide (the intermediate and end product of sulphate reduction) increased protease activity by 20% and 40%-80%, respectively. Maximum protease activity occurred on day 21 in the methanogenic reactor and on day 9 in the sulphidogenic reactor. The absorbance, which indicates the level of amino acid increased to 2 and 9 for methanogenic and sulphidogenic bioreactors, respectively. Proteases that were active during anaerobic digestion were associated with the pellet (organic particulate matter) of the sewage. These enzymes have an optimum activity at pH 10 and at temperature of 50°C. The proteases that were active at pH 5 and 7, had optimum temperatures at 30°C and 60°C, respectively. Due to their association with organic particulate matter, these enzymes were stable at their optimum temperatures for at least five hours at their respective pH. Inhibition by PMSF, TPCK and 1.10-phenanthroline suggested that proteases inside the anaerobic digester are a mixture of cysteine, serine and metalloproteases. At pH 5, however, EDTA appeared to enhance protease activity by 368% (three-fold). Acetic acid decreased protease activity by 21%, while both propionic and butyric acid at 200 mg/L cause total inhibition of protease activity while these acids at higher pH (where they exist as their corresponding salts) exerted little effect. Copper, iron and zinc inhibited protease activity by 85% at pH 5 with concentrations ranging between 200 and 600 mg/L. On the other hand, nickel, showed an increase in protease activity of nearly 250%. At pH 7 and 10, copper had no effect on protease activity while iron, nickel and zinc inhibited these enzymes by 20-40%. Proteases at pH 7 were extracted from the pellet by sonication, releasing 50% of the total enzymes into the solution. The enzymes were precipitated by ammonium sulphate precipitation, and further purified by ion exchange chromatography and gel filtration. Ion exchange chromatography revealed that most of the enzymes that hydrolyse proteins are negatively charged while gel filtration showed that their molecular weight is approximately 500 kDa.
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Expanding the capabilities of the DPS lonosonde system

  • Authors: Magnus, Lindsay Gerald
  • Date: 2001
  • Subjects: Ionosondes
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5560 , http://hdl.handle.net/10962/d1018243
  • Description: The Digisonde Portable Sounder (DPS) is a low power pulse ionosonde capable of recording a wealth of scientific information about the ionosphere. The routine vertical incidence mode, that produces the scaled ionospheric parameters, only records limited Doppler and no precise angle of arrival (AoA) information. The drift mode produces precise scientific information but only limited range information. This thesis explains the operation of the DPS and then examines the drift data by first showing the Doppler velocities (V*) calculated for a fixed frequency ionogram as well as the velocities calculated from an interesting ionospheric disturbance measured with a stepped frequency ionogram and second by illustrating the presence of a variation in the AoA of ionospheric echoes at sunrise. The conclusion of the thesis is that a drift vertical incidence mode be developed to allow the simultaneous measurement of the scaled ionospheric parameters and the precise AoA and full Doppler spectrum information.
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Experiences in porting a virtual reality system to Java

  • Authors: Bangay, Shaun D
  • Date: 2001
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/433157 , vital:72947 , https://doi.org/10.1145/513867.513875
  • Description: Practical experience in porting a large virtual reality system from C/C++ to Java indicates that porting this type of real-time application is both feasible, and has several merits. The ability to transfer objects in space and time allows useful facilities such as distributed agent support and persistence to be added. Reflection and type comparisons allow flexible manipulations of objects of different types at run-time. Native calls and native code compilation reduce or remove the overhead of interpreting code.Problems encountered include difficulty in achieving cross-platform code portability, limitations of the networking libraries in Java, and clumsy coding practices forced by the language.
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Exploring job satisfaction amongst government social workers in East London

  • Authors: Sela, Michelle
  • Date: 2001
  • Subjects: Social workers -- Supervision of , Social workers -- Professional ethics , Social workers -- South Africa -- Eastern Cape -- Attitudes , Social service -- Vocational guidance
  • Language: English
  • Type: Thesis , Masters , MSocSc
  • Identifier: vital:705 , http://hdl.handle.net/10962/d1006499 , Social workers -- Supervision of , Social workers -- Professional ethics , Social workers -- South Africa -- Eastern Cape -- Attitudes , Social service -- Vocational guidance
  • Description: During this research an attempt was made to gain an understanding of job satisfaction amongst government social workers. To achieve this, twenty social workers employed at the Department of Welfare in East London and Mdantsane were interviewed. South African literature on this topic is limited and it is believed that this study will present a valuable basis to pursue in further research. Literature that was consulted was found to be supportive of the theoretical notion that social work has long been recognised as being a stressful profession and that the nature of social work practice itself can be potentially stressful. The study found that there are many stressors and dissatisfactions which government social workers are currently experiencing. Some of the social workers have indicated a desire to leave the profession as a result of the dissatisfactions. The study findings suggest a need for combining oganisational with individual oriented initiatives to decrease the many stressors the social workers are experiencing. The thesis ends with recommendations of various strategies for addressing the concerns of the social workers in order to increase their job satisfaction
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Extractives from six species of South African Marine Opisthobranch Molluscs

  • Authors: McPhail, Kerry Lee
  • Date: 2001
  • Subjects: Mollusks -- Nutrition Mollusks -- Anatomy Marine fishes -- South Africa
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:4433 , http://hdl.handle.net/10962/d1007412
  • Description: The natural product chemistry of six species of South African opisthobranch molluscs and some of their dietary marine invertebrates was investigated. Nineteen previously undescribed secondary metabolites and twelve known compounds were isolated and their structures determined by a combination of spectroscopic and chemical methods. The circumtropical sea hares Aplysia parvula and A. dactylomela were found to contain halogenated red algal metabolites. 3Z-bromofucin (120), the Z analogue of a known Laurencia CIS acetogenin, was isolated from A. parvula. A. dactylomela yielded a series of novel non-aromatic cuparanes, the algoanes (121-123), the novel tricyclic Iaurane ether ibhayinol (124) and three known chamigrane sesquiterpenes, prepacifenol epoxide (101), pacif-7-enediol (104) and nidificene (125). A variety of new octocoral sesquiterpenes were isolated from the endemic South African arminacean nudibranch Leminda millecra including algoafuran (150), cubebenone (151), 8-hydroxycalamenene (152) and a series of seven triprenylated toluquinones and toluquinols (153-159). L. millecra also yielded the known sesquiterpenes millecrones A (142) and B (143) and isofuranodiene (149). Twenty eight voucher specimens and eighteen crude extracts of South African octocorals collected by the Coral Reef Research Foundation were screened by GC and GC-MS and 142 was found in Alcyonium fauri, while 143, 151 and possibly 149 were present in Leptogorgia palma. An investigation of southern African chromodorids yielded the known macrocyc1e latrunculin B (220) and two new spongiane diterpenes (221) and (222) from Chromodoris hamiltoni, while the known spongiane diterpene (210) was isolated from the endemic nudibranch Glossodoris sp. 4. The endemic nudibranch Hypselodoris capensis contained the known furanosesquiterpenes nakafuran-8 (223) and -9 (224) and the known furanosesterterpenes variabilin (195), 22-deoxyvariabilin (225) and furospinosulin (227) together with the new variant 22-deoxy-23-hydroxymethylvariabilin (226). Compounds 223 and 224 were also found in a Dysidea sponge, while the furanosesterterpenes 195, and 225-227 were present in a Fasciospongia sponge upon which H capensis specimens were found. The Dysidea dietary sponge of H capensis also yielded a new aromatic sesquiterpene, tsitsikarnmafuran (266), whose structure was confirmed by the synthesis of two possible regioisomers.
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Factors Influencing the Entrepreneurial Orientation of Students

  • Authors: Amos, Trevor L , Louw, L , Baxter, Jeremy
  • Date: 2001
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/270879 , vital:54488 , xlink:href="https://scialert.net/abstract/?doi=jas.2001.329.334"
  • Description: With entrepreneurship being an important catalyst in wealth creation, it is imperative that entrepreneurs be developed. The aim of this exploratory research is to contribute to our understanding of the development of entrepreneurs and to encourage further research in the area. This paper proposes a model of entrepreneurship and tests the influencing factors on this model. Based on the findings of this research, it appears that entrepreneurial activity of family members influences the development of entrepreneurship more than gender, race, age or education. With education being a logical site for the development of entrepreneurship within society, this finding raises more questions than it provides answers, highlighting the need for educators to critically review the educational process if entrepreneurship is to be a realistic outcome.
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Failure rather than success : conflict management and resolution in the Democratic Republic of Congo, 1996-1999

  • Authors: Munyae, Isaac Muinde
  • Date: 2001
  • Subjects: Conflict management -- Congo (Democratic Republic) , Dispute resolution (Law) -- Congo (Democratic Republic). , Congo (Democratic Republic) -- History -- 1997-
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:2856 , http://hdl.handle.net/10962/d1007427 , Conflict management -- Congo (Democratic Republic) , Dispute resolution (Law) -- Congo (Democratic Republic). , Congo (Democratic Republic) -- History -- 1997-
  • Description: History has proven time and time again that conflict is an inevitable aspect of any given society. The seemingly long-standing nature of conflicts in Africa has been changing over time and these conflicts have been either inter-state or intra-state. However, sometimes intrastate wars have escalated into regional conflicts. These scenarios can be seen in the Great Lakes region of Africa where you have the civil war of 1996-7 and the rebellion, which began in 1998 in the Democratic Republic of Congo (DRC). In the DRC there have been at least four stages of conflict. The first is against the Belgians and secondly, the civil strife of the early 1960s. Third, is the civil strife against Mobutu and fourthly, currently against Kabila. The expanding nature of conflict is characterised by power struggles, politicisation of ethnicity, and the impact of external forces. It is noted that the expanding nature of conflict calls for a change in the methods of conflict management and resolution. Initially conflicts were resolved through military intervention. but with the complexity of African wars it has become apparent that peaceful methods are more prudent. With reference to Africa it can be assumed that conflicts need to be increasingly resolved through political means, such as the use of the diplomatic process. The conflict in Chad between 1968 and 1984 is a good example in which military intervention was used but failed, giving way to mediation and negotiation through the use of diplomacy. Both the DRC and Chadian conflicts are similar because they witnessed the influence of external forces (neighbouring countries and non-African states such as France and the US) and African states attempting to find solutions to their own problems. The conflict in the DRC provides a unique example of the changing nature of intra-state conflict in Africa. Thus, the study aims to trace the characteristics of conflict in the DRC and attempts made at conflict management and resolution. The study uses the period bet ween 1996 and 1999 because it highlights this change in the nature and character of conflict.
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