Showing items 221 - 240 of 394

Your selections:

Mycorrhizal status of indigenous tree species in a forest biome of the Eastern Cape, South Africa

- Hawley, Greer L, Dames, Joanna F

  • Authors: Hawley, Greer L , Dames, Joanna F
  • Date: 2004
  • Language: English
  • Type: Article
  • Identifier: vital:6458 , http://hdl.handle.net/10962/d1005774
  • Description: Mycorrhizal fungi are intimately associated with plant roots, affecting plant growth, health and increasing the plants' tolerance to environmental stress. Several mycorrhizal types are recognized based primarily on morphological characteristics within plant roots. When considering propagation and management of an indigenous plant species, it is essential to know its mycorrhizal status. Root samples from 17 tree species common to the pockets of forest in the Eastern Cape province, and representing the families Rubiaceae, Scrophulariaceae, Oleaceae, Podocarpaceae, Myrsinaceae, Anacardiaceae, Caesalpinoideae, Papilionoideae, Rutaceae, Meliaceae, Celastraceae, Flacouticeae and Ebenaceae, were sampled and examined for mycorrhizal colonization. Microscopic examination of all the species produced evidence of morphological structures indicative of endomycorrhizal associations as indicated by the presence of intercellular hyphae combined with vesicles, arbuscules or hyphal coils. Hyphal coils (also known as Paris-type associations) appeared to be abundant, especially within the Cassine genus. Arbuscules (also known as Arum-type associations) were scarce but sometimes present, and vesicles were prolific in Olea capensis. Most of the tree species examined have been assigned arbuscular mycorrhizal status. No ectomycorrhizal associations were recorded
  • Full Text:
  • Date Issued: 2004

Neural network-based ionospheric modelling over the South African region

- McKinnell, Lee-Anne, Poole, Allon W V

  • Authors: McKinnell, Lee-Anne , Poole, Allon W V
  • Date: 2004
  • Language: English
  • Type: Article
  • Identifier: vital:6795 , http://hdl.handle.net/10962/d1003839
  • Description: During the past decade, South African scientists have pioneered research in the field of ionospheric modelling using the technique of neural networks (NNs). Global ionospheric models have always been insufficient for the South African region owing to an historical paucity of available data. Within the past 10 years, however, three new ionospheric sounders have been installed locally and are operating continuously. These sounders are located at Grahamstown (33.3°S, 26.5°E), Louisvale (28.5°S, 21.2°E) and Madimbo (22.4°S, 30.9°E). The addition of a modern sounder at Grahamstown enlarged the ionospheric database for this station to 30 years, making this archive a considerable asset for ionospheric research. Quality control and online availability of the data has also added to its attraction. An important requirement for empirical modelling, but especially for employing NNs, is a large database describing the history of the relationship between the ionosphere and the geophysical parameters that define its behaviour. This review describes the path of South African ionospheric modelling over the past 10 years, the role of NNs in this development, the international collaborations that have arisen from this, and the future of ionospheric modelling in South Africa.
  • Full Text:
  • Date Issued: 2004

Nuclear translocation of the Hsp70/Hsp90 organizing protein mSTI1 is regulated by cell cycle kinases

- Longshaw, Victoria M, Chapple, J Paul, Cheetham, Michael E, Blatch, Gregory L

  • Authors: Longshaw, Victoria M , Chapple, J Paul , Cheetham, Michael E , Blatch, Gregory L
  • Date: 2004
  • Language: English
  • Type: Article
  • Identifier: vital:6488 , http://hdl.handle.net/10962/d1006271 , https://dx.doi.org/10.1242/jcs.00905
  • Description: The co-chaperone murine stress-inducible protein 1 (mSTI1), an Hsp70/Hsp90 organizing protein (Hop) homologue, mediates the assembly of the Hsp70/Hsp90 chaperone heterocomplex. The mSTI1 protein can be phosphorylated in vitro by cell cycle kinases proximal to a putative nuclear localization signal (NLS), which substantiated a predicted casein kinase II (CKII)-cdc2 kinase-NLS (CcN) motif at position 180-239 and suggested that mSTI1 might move between the cytoplasm and the nucleus under certain cell cycle conditions. The mechanism responsible for the cellular localization of mSTI1 was probed using NIH3T3 fibroblasts to investigate the localization of endogenous mSTI1 and enhanced green fluorescent protein (EGFP)-tagged mSTI1 mutants. Localization studies on cell lines stably expressing NLS(mSTI1)-EGFP and EGFP demonstrated that the NLS(mSTI1) was able to promote a nuclear localization of EGFP. The mSTI1 protein was exclusively cytoplasmic in most cells under normal conditions but was present in the nucleus of a subpopulation of cells and accumulated in the nucleus following inhibition of nuclear export (leptomycin B treatment). G1/S-phase arrest (using hydroxyurea) and inhibition of cdc2 kinase (using olomoucine) but not inhibition of casein kinase II (using 5,6-dichlorobenzimidazole riboside), increased the proportion of cells with endogenous mSTI1 nuclear staining. mSTI1-EGFP behaved identically to endogenous mSTI1. The functional importance of key residues was tested using modified mSTI1-EGFP proteins. Inactivation and phosphorylation mimicking of potential phosphorylation sites in mSTI1 altered the nuclear translocation. Mimicking of phosphorylation at the mSTI1 CKII phosphorylation site (S189E) promoted nuclear localization of mSTI1-EGFP. Mimicking phosphorylation at the cdc2 kinase phosphorylation site (T198E) promoted cytoplasmic localization of mSTI1-EGFP at the G1/S-phase transition,whereas removal of this site (T198A) promoted the nuclear localization of mSTI1-EGFP under the same conditions. These data provide the first evidence of nuclear import and export of a major Hsp70/Hsp90 co-chaperone and the regulation of this nuclear-cytoplasmic shuttling by cell cycle status and cell cycle kinases.
  • Full Text:
  • Date Issued: 2004

Occupational aspirations and gender stereotyping of Xhosa-speaking senior primary learners

- Els, Catherine

  • Authors: Els, Catherine
  • Date: 2004
  • Subjects: Vocational interests -- South Africa -- Research , Gender identity , School children -- South Africa -- Attitudes , Xhosa (African people) -- Attitudes
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:11020 , http://hdl.handle.net/10948/325 , Vocational interests -- South Africa -- Research , Gender identity , School children -- South Africa -- Attitudes , Xhosa (African people) -- Attitudes
  • Description: International research highlights conflicting results regarding factors that could play a role in the development of occupational aspirations and occupational gender stereotyping of primary school children. Some of the variables that have been identified are age, gender, ethnicity, socioeconomic status and societal influences. There has been some research emphasis on the career development of South Africans. However, studies that have been conducted have focused mainly on adolescents and adults. Furthermore, the majority of this research has focused on programme intervention and not on acquiring baseline information. There has been no research to date on the career development of South African Xhosa-speaking senior primary school children. The lack of career research on South African Xhosa-speaking children indicates the need for the present research. This study aims to describe and compare the occupational aspirations and occupational gender stereotyping (in terms of Holland’s occupational and status level typology) of male and female Xhosa-speaking senior primary school learners. The study also describes the possible gender stereotypical perceptions preadolescent children hold regarding certain occupations. A non-probability sample of 274 Xhosa-speaking children between the ages of 10 and 14 years was drawn from two primary schools in townships in the Nelson Mandela Metropole. An exploratory and descriptive research framework was utilised, with descriptive statistical procedures employed to summarise and report the data in a meaningful manner. The major findings of the present study indicate that Xhosa-speaking senior primary school children’s favourite occupational aspirations fit into Holland’s Investigative typology and high status level. Some gender differences were evident, with slightly more boys aspiring to Investigative occupations than girls. Both boys and girls demonstrated gender stereotypical perceptions regarding xiii which occupations were suitable for both genders, with boys more willing to accept girls into traditional male occupations than girls willing to accept boys into traditional female occupations. The results of the present study emphasise the need for further exploration of the occupational aspirations and occupational ge nder stereotyping of Xhosa-speaking senior primary school children. Future research needs to include other cultural and age groups in order to explore how personal and situational variables may differentially influence children’s occupational aspirations and occupational gender stereotyping.
  • Full Text:
  • Date Issued: 2004

Oh! yini yinikangaka

- Rodolo, L. S., Dubeni, N., Mgidi, A., Tshona, S. S., Composer not specified, Dargie, Dave

Oliver Tambo

- Nduna, S., Mgidi, A., Dubeni, N., Rodolo, L. S., Mngesi, N. M., Mgeni, N., Dubeni, T., Letsika, S. T., Hangana, S., Mgidi, A. T. V., Composer not specified, Dargie, Dave

On becoming an African-Asian English academic at Rhodes University

- Naidu, Samantha

  • Authors: Naidu, Samantha
  • Date: 2004
  • Language: English
  • Type: text , article
  • Identifier: vital:21926 , http://hdl.handle.net/10962/14392 , https://0-www.jstor.org.wam.seals.ac.za/stable/24487641
  • Description: preprint , I arrived at Rhodes University English Department with not much more than a passion for literature. During the last fourteen years I have been able to observe the discipline in operation. My perspective has broadened and deepened, taking in the trajectory from Stanley Kidd and the colonial Cambridge practices, and from what might be termed the 'humanist enterprise of English studies', 1 to the white liberalism of Guy Butler in the middle of the twentieth century, then to the present post-apartheid era of humanities cutbacks and increasing commodification of knowledge.
  • Full Text:
  • Date Issued: 2004

On the mocvd growth of ZnO

- Pagni, Olivier Demeno

  • Authors: Pagni, Olivier Demeno
  • Date: 2004
  • Subjects: Zinc oxide thin films , Metal organic chemical vapor deposition
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:11075 , http://hdl.handle.net/10948/382 , Zinc oxide thin films , Metal organic chemical vapor deposition
  • Description: Zinc oxide (ZnO) is a II-VI semiconductor material that offers tremendous potential as a light emitter in the blue-to-UV range. It has a wurtzite structure, and a direct band gap that can be tuned from 3.0 to 4.0 eV by alloying with Cd or Mg, respectively. In this work, ZnO thin films were grown by metalorganic chemical vapor deposition (MOCVD) on n-Si 2 ° off (100), amorphous glass, n-GaAs (100), and c-plane sapphire substrates. Diethyl zinc (DEZn) and tert-butanol (TBOH) were chosen as precursors. For the first time, Second Harmonic Generation Imaging was applied to the mapping of ZnO epilayers. The images obtained highlighted the polycrystalline character of the thin films, and provided insight as to the growth mode of ZnO on Si. The influence of substrate temperature on the structural properties of the epilayers was investigated by X-ray diffraction and optical microscopy. Grain sizes as high as 54 nm were measured. The optimum temperature range for this system proved to be 450 – 500 °C. The influence of the VI:II ratio during growth on the optical properties of the epilayers was studied by UV-vis-near IR spectroscopy. The lowest Urbach tail E0 parameter was measured for material grown at a VI:II ratio of 18:1. The films’ free electron concentration was shown to decrease by over two orders of magnitude, from 1019 to 1017 cm-3, as the VI:II ratio increased from 10 to 60:1. This decrease in carrier concentration with rising VI:II ratio was paralleled to the surge at 12 K of a photoluminescence (PL) emission band characteristic of p-type ZnO. The band gap energies extracted from room temperature transmission spectra ranged between 3.35 and 3.38 eV, in agreement with the value of 3.35 eV measured by room temperature PL. Moreover, variable temperature PL spectra were recorded between 12 and 298 K on ZnO grown on Si. The 12 K spectrum was dominated by a donor-bound exciton (D°X) at 3.36 eV, while the 298 K scan displayed strong free exciton emission (FX) at 3.29 eV. The width of the D°X band proved to be as narrow as 7 meV. The intensity ratio between the room temperature near-band edge emission and the defect-related green band was as high as 28:1, highlighting the optical quality of the layers deposited in this work. The electrical properties of the thin films were studied by Hall measurements (van der Pauw configuration), and a maximum room temperature mobility of 11 cm2/Vs was recorded. Furthermore, a palladium (Pd) Schottky barrier diode on ZnO was fabricated. The barrier height and ideality factor were calculated from current–voltage measurements to be 0.83 eV and 1.6, respectively. The capacitance–voltage curve of the diode yielded a carrier concentration in the depletion region of 8·1017 cm-3. This study has shown that the optical and electrical properties of ZnO depend strongly on the growth conditions employed. A suitable choice of growth parameters can yield high quality ZnO that may be used for various devices. Keywords: Hall, MOCVD, optical spectroscopy, photoluminescence, Schottky barrier diode, SH Imaging, X-ray diffraction, ZnO.
  • Full Text:
  • Date Issued: 2004

One hundred years of botany at Rhodes University

- Lubke, Roy, Brink, Estelle

  • Authors: Lubke, Roy , Brink, Estelle
  • Date: 2004
  • Language: English
  • Type: Article
  • Identifier: vital:6523 , http://hdl.handle.net/10962/d1005954
  • Description: The Botany Department of Rhodes University is located in the historic Schonland Building. An indigenous garden was created in its courtyard, mainly of species of the Eastern Cape province, and its growth in diversity and stature mirrors the changes in the department over the years. Professor Selmar Schonland, the founding father of botany at Rhodes, was also the curator/director of the Albany Museum. Under his leadership, systematics was firmly established as a discipline at Rhodes and research on the flora of the Eastern Cape begun, to be continued to this day. Under professors William Isaac (1949–1951) and Edgar Twyman (1951–1973), plant physiology became an important area of study, and future leaders in physiology at other universities obtained degrees under them. Phycology and aquatic ecology became notable disciplines with Mary Pocock’s world-class work in the 1940s on freshwater and marine algae, which inspired others such as head of department Professor Stanley Seagrief (1958–1986) to develop these studies further. Mycology and microbiology were established as major subdisciplines under Noel Smith (1926–1948) and Twyman through to the 1960s, when the Department of Microbiology was established. Early studies in ecology owe their success to Tony Martin (1947–1956) and the link with the Grahamstown Botanical Research Station, when a sound base for plant ecology in the Eastern Cape was established. Coastal ecology became a major focus in the 1970s, when Roy Lubke and Ted Avis concentrated on dunes and the management of coastal regions. This led to the establishment of the Department of Environmental Science in the 1990s. The expertise of the botany staff in teaching and research in a variety of fields is reflected in the careers of its many students around the world.
  • Full Text:
  • Date Issued: 2004

Oomashayela phezulu:

- Mazibuko, Nokuthula, Kaschula, Russell H

  • Authors: Mazibuko, Nokuthula , Kaschula, Russell H
  • Date: 2004
  • Language: Zulu
  • Type: text , book
  • Identifier: http://hdl.handle.net/10962/175323 , vital:42565 , ISBN 9781869284251
  • Description: ‘Sam, khawuphole maan, thob'umoya. KungoLwesihlanu namhlanje, sakuba nalo ithuba elininzi ngomso lokuzithethelela ebazalini bethu! Ha, ha, ha!'wagigitheka uBrunette'Thatha nantsi icider, usele!'UBrunette wayonwabile, wayekuthanda futhi ekonwabela ngoku ukusela, kwaye ezi iicider zazingavakali ngathi butywala! Wayeziva efanelekile kwibhulukhwe yakhe ebomvu, ethe nca kuye emzimbeni kakuhle, nehempe awayeyinxibe ngentla ehambelana nayo, nezihlangu ezichophileyo awayezinxibile. Wagqiba kwangexesha ukuphotha iinwele zakhe ngoboya bomsila wehashe, elungele ipati eyayiza kuba ngobo busuku. Yayintle into yokuba abe woluka iinwele zabantu. Ngokwenza njalo wayezenzela.
  • Full Text:
  • Date Issued: 2004

Optimization of a manufacturing process for atrazine with a focus on waste minimization

- Mtyopo, Mteteleli Bethwell

  • Authors: Mtyopo, Mteteleli Bethwell
  • Date: 2004
  • Subjects: Waste minimization , Atrazine -- Environmental aspects
  • Language: English
  • Type: Thesis , Masters , MTech
  • Identifier: vital:10976 , http://hdl.handle.net/10948/259 , Waste minimization , Atrazine -- Environmental aspects
  • Description: Chemical synthesis is not complete without waste treatment. There is no chemical process that does not produce waste. The untreated effluent discharged by chemical industries poses a major environmental concern. This dissertation describes the results of an investigation carried out on the formation of by-products (impurities) during the synthesis of atrazine by neutralization of the reaction mixture during the actual synthesis procedure, and prior to disposal using carbon dioxide or hydrochloric acid. The main objectives for the said investigation were: {u100083} To optimise the reaction parameters to obtain a higher yield and purity of atrazine. {u100083} To evaluate the use of carbon dioxide and hydrochloric acid to neutralise the reaction mixture. {u100083} To study the solids present in the effluent. Synthetic reactions were carried out in the presence of an organic solvent, methyl isobutyl ketone (MIBK). The synthesis of atrazine was optimised in terms of addition sequence and rates of amine reagents and base (proton acceptor) additions by means of bench scale reactions. It was found that addition of a neutralising step (hydrochloric acid or carbon dioxide) to neutralise the basic reaction mixture prior to and after addition of the secondary amine and the base minimizes the formation of by-products. Of particular importance in ensuring high yields and selectivity to the atrazine product was temperature control, pH control, reagent ratios, addition rates and mixing. The latter was important in view of the rapid reaction of amine/NaOH with cyanuric chloride, as well as the possible reaction of mono-i, the reaction intermediate, with IPA in cases of excesses of reagent. Under optimum conditions, an atrazine composition of >97% was achieved where the resultant product was well within stipulated product specifications.
  • Full Text:
  • Date Issued: 2004

Over-expression, purification and biochemical characterization of DOXP reductoisomerase and the rational design of novel anti-malarial drugs

- Tanner, Delia Caroline

  • Authors: Tanner, Delia Caroline
  • Date: 2004
  • Subjects: Malaria -- Prevention , Malaria -- Drug therapy , Antimalarials -- Therapeutic use , Proteins -- Purification , Amino acids -- Analysis
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:3931 , http://hdl.handle.net/10962/d1003990 , Malaria -- Prevention , Malaria -- Drug therapy , Antimalarials -- Therapeutic use , Proteins -- Purification , Amino acids -- Analysis
  • Description: Malaria poses the greatest threat of all parasites to human life. Current vaccines and efficacious drugs are available however their use is limited due to toxicity, emergence of drug resistance, and cost. The discovery of an alternative pathway of isoprenoid biosynthesis, the non-mevalonate pathway, within the malarial parasite has resulted in development of novel anti-malarial drugs. 1-Deoxy-D-xylulose-5-phosphate (DOXP) reductoisomerase, the second enzyme in this pathway, is responsible for the synthesis of 2-C-methyl-D-erythritol 4-phosphate (MEP) in an intramolecular rearrangement step followed by a reduction process involving NADPH as a hydrogen donor and divalent cations as co-factors. Fosmidomycin and FR900098 have been identified as inhibitors of DOXP reductoisomerase. However, they lack clinical efficacy. In this investigation recombinant DOXP reductoisomerase from Escherichia coli (EcDXR) and Plasmodium falciparum (pfDXR) were biochemically characterized as potential targets for inhibition. (His)6-EcDXR was successfully purified using nickel-chelate affinity chromatography with a specific activity of 1.77 μmoles/min/mg and Km value 282 μM. Utilizing multiple sequence alignment, previous structural data predictions and homology modeling approaches, critical active site amino acid residues were identified and their role in the catalytic activity investigated utilizing site-directed mutagenesis techniques. We have shown evidence that suggests that Trp212 and Met214 interact to maintain the active site architecture and hydrophobic interactions necessary for substrate binding, cofactor binding and enzyme activity. Replacement of Trp212 with Tyr, Phe, and Leu reduced specific activity relative to EcDXR. EcDXR(W212F) and EcDXR(W212Y) had an increased Km relative to EcDXR indicative of loss in affinity toward DOXP, whereas EcDXR(W212L) had a lower Km of ~8 μM indicative of increased affinity for DOXP. The W212L substitution possibly removed contacts necessary for full catalytic activity, but could be considered a non-disruptive substitution in that it maintained active site architecture sufficient for DOXP reductoisomerase activity. EcDXR(M214I) had 36-fold reduced enzyme activity relative to EcDXR, while its Km (~8 μM) was found to be lower than that of EcDXR. This suggested that the M214I substitution had maintained (perhaps improved) substrate and active site architecture, but may have perturbed interactions with NADPH. Rational drug design strategies and docking methods have been utilized in the development of furan derivatives as DOXP reductoisomerase inhibitors, and the synthesis of phosphorylated derivatives (5) and (6) has been achieved. Future inhibitor studies using these novel potential DOXP reductoisomerase inhibitors may lead to the development of effective anti-malarial drug candidates.
  • Full Text:
  • Date Issued: 2004

Particle precipitation effects in the daytime E-region in the South Atlantic Anomaly region

- Haggard, Raymond

  • Authors: Haggard, Raymond
  • Date: 2004
  • Language: English
  • Type: Article
  • Identifier: vital:6794 , http://hdl.handle.net/10962/d1003836
  • Description: The behaviour of the normal daytime E-layer over the South Atlantic Anomaly region during 23 days of project ISAAC (29 June to 21 July 1983) has been examined. Enhanced production rates due to precipitated electrons were calculated from the observed data and compared well with the production rates from the mean electron fluxes in the range 0.2–26 keV observed from the satellite Atmosphere Explorer-C during 1973–77, discussed by Gledhill and Hoffman.1 The present study shows that there is evidence of a significant source of extra ionization, in addition to solar ultraviolet and X-radiation, in the South Atlantic Anomaly region.
  • Full Text:
  • Date Issued: 2004

Petrology and geochemistry of Early Cretaceous bimodal continental flood volcanism of the NW Etendeka, Namibia Part 1: introduction, mafic lavas and re-evaluation of mantle source components

- Ewart, A, Marsh, Julian S, Milner, Simon C, Duncan, Andrew R, Kamber, B S, Armstrong, R A

  • Authors: Ewart, A , Marsh, Julian S , Milner, Simon C , Duncan, Andrew R , Kamber, B S , Armstrong, R A
  • Date: 2004
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/150583 , vital:38986 , https://doi.org/10.1093/petrology/egg083
  • Description: The bimodal NW Etendeka province is located at the continental end of the Tristan plume trace in coastal Namibia. It comprises a high-Ti (Khumib type) and three low-Ti basalt (Tafelberg, Kuidas and Esmeralda types) suites, with, at stratigraphically higher level, interstratified high-Ti latites (three units) and quartz latites (five units), and one low-Ti quartz latite. Khumib basalts are enriched in high field strength elements and light rare earth elements relative to low-Ti types and exhibit trace element affinities with Tristan da Cunha lavas.
  • Full Text: false
  • Date Issued: 2004

Petrology and geochemistry of early cretaceous bimodal continental flood volcanism of the NW Etendeka, Namibia Part 2: characteristics and petrogenesis of the high-Ti latite and high-Ti and low-Ti voluminous quartz latite eruptives

- Ewart, A, Marsh, Julian S, Milner, Simon C, Duncan, Andrew R, Kamber, B S, Armstrong, R A

  • Authors: Ewart, A , Marsh, Julian S , Milner, Simon C , Duncan, Andrew R , Kamber, B S , Armstrong, R A
  • Date: 2004
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/150593 , vital:38987 , https://doi.org/10.1093/petrology/egg082
  • Description: As a result of their relative concentration towards the respective Atlantic margins, the silicic eruptives of the Paraná (Brazil)–Etendeka large igneous province are disproportionately abundant in the Etendeka of Namibia. The NW Etendeka silicic units, dated at ∼132 Ma, occupy the upper stratigraphic levels of the volcanic sequences, restricted to the coastal zone, and comprise three latites and five quartz latites (QL).
  • Full Text: false
  • Date Issued: 2004

Phenomenology in education : a case study in educational leadership

- Van der Mescht, Hennie

  • Authors: Van der Mescht, Hennie
  • Date: 2004
  • Language: English
  • Type: Article
  • Identifier: vital:6101 , http://hdl.handle.net/10962/d1008665
  • Description: [From the introduction]: Overheard during tea at an Education Faculty research design course: “Phenomenology produces interesting and surprising results, but it’s just too much work …” The speaker was a prospective Masters student who had decided against “phenomenological” research, presumably because “it’s just too much work”. Having been deeply involved in phenomenological research myself for some years, I could identify with his reservation. But his first statement is of course equally true: phenomenological research does indeed produce “interesting and surprising results”, as many of my students have found. I should at the outset describe what I mean by phenomenological research more carefully, since, as Schweitzer (2002) has recently pointed out, there is certainly more than one meaning out there. The kind of research I am referring to is not the kind frequently featured in this journal, which Schweitzer (2002) describes as “Husserlian”, but another kind, which he describes as “‘what’s it like for them’ type of studies”. In this paper I present a case for the latter, and consider its appropriateness to the field of education. I argue that this approach to phenomenological research (which Schweitzer refers to as empirical) is a potentially powerful way of making sense of education practitioners’ (and learners’) sense-making, and can lead to startling new insights into the uniquely complex processes of learning, teaching and educational managing and leading.
  • Full Text:
  • Date Issued: 2004

Phylogeny, biogeography, and the evolution of life-history traits in Leucadendron (Proteaceae)

- Barker, Nigel P, Vanderpoorten, Alain, Morton, Cynthia M, Rourke, John P

  • Authors: Barker, Nigel P , Vanderpoorten, Alain , Morton, Cynthia M , Rourke, John P
  • Date: 2004
  • Language: English
  • Type: Article
  • Identifier: vital:6496 , http://hdl.handle.net/10962/d1004491
  • Description: Leucadendron is a moderately large genus of Proteaceae almost entirely restricted to the Cape Floristic Region of southern Africa. The genus is unusual in being dioecious and sexually dimorphic. ITS sequence data were obtained from 62 of the 96 currently recognized taxa (85 species and 11 subspecies). Phylogenetic analyses were conducted under Maximum Likelihood and parsimony and resolved nine groups of species with varying degrees of bootstrap support, but relationships between these groups are largely unsupported. The phylogeny conflicts with the current taxonomic arrangement, which is based mainly on fruit morphology. The two sections of the genus, Alatosperma and Leucadendron, and several subsections within these sections, are resolved as non-monophyletic. This means that taxonomically important characters (such as fruit shape) have evolved multiple times, as the species with nutlike fruit (resolved into two of the nine groups) appear to have evolved independently from ancestors with winged fruit. Based on the topology obtained, the life history traits of anemophily, myrmechochory, and re-sprouting have also originated multiple times. Dispersal–Vicariance (DIVA) analysis suggests that the genus had an ancestral area in the Karoo Mountain and Southeastern phytogeographic centres of endemism in the southwestern Cape. , Elsevier
  • Full Text:
  • Date Issued: 2004

Pictograms for conveying medicine instructions: comprehension in various South African language groups

- Dowse, Roslind, Ehlers, Martina S

  • Authors: Dowse, Roslind , Ehlers, Martina S
  • Date: 2004
  • Language: English
  • Type: Article
  • Identifier: vital:6354 , http://hdl.handle.net/10962/d1006038
  • Description: The comprehension of medicine instructions is essential for the safe and effective use of medicines. In cases where low literacy constitutes a possible barrier to understanding written medicine information fully, the inclusion of pictograms may facilitate comprehension. Twenty-three internationally available pictograms and 23 corresponding locally developed images were evaluated in 304 low-literate respondents from eight different South African language groups. Demographic data were collected and an English literacy test was administered to those respondents who had stated that they could read English. Interviewees were shown the 46 pictograms in random order and were asked for their interpretation. Preference for either the international or local version was assessed. Correct interpretation of individual pictograms ranged from 14% to 97%. Images which had been developed locally were more successful in eliciting correct interpretations than those obtained from an international source (USP pictograms). Only 2 of the 23 USP pictograms achieved the 85% criterion of the American National Standards Institute compared with 12 of 23 locally developed counterparts. Local pictograms were preferred over the American ones in all cases. Standard of education had a significant influence on interpretation, whereas no significant differences in interpretation could be attributed to cultural diversity between the African language groups. Almost all respondents (98%) reacted positively to the idea of having pictograms on their medicine labels. The success of the local pictograms highlighted the value of a rigorous and consultative design and test process. Results from one African language group can reliably be extrapolated to other groups in South Africa.
  • Full Text:
  • Date Issued: 2004

Politics, latent and overt, in Hill of Fools

- Wright, Laurence

  • Authors: Wright, Laurence
  • Date: 2004
  • Language: English
  • Type: Article
  • Identifier: vital:7064 , http://hdl.handle.net/10962/d1007430
  • Description: [From the text]: R. L. Peteni’s novel Hill of Fools (1976) is a work that benefits greatly when Collingwood’s maxim is observed. The author’s family history and the circumstances surrounding the book’s publication add a dimension of political and social meaning which its surface deliberately occludes. Perhaps more importantly, while the story can readily be enjoyed, the quality of sensibility behind the work is not readily accessed without understanding some of the socio-political background.
  • Full Text:
  • Date Issued: 2004

Pollination biology of Bergeranthus multiceps (Aizoaceae) with preliminary observations of repeated flower opening and closure

- Peter, Craig I, Dold, Anthony P, Barker, Nigel P, Ripley, Bradley S

  • Authors: Peter, Craig I , Dold, Anthony P , Barker, Nigel P , Ripley, Bradley S
  • Date: 2004
  • Language: English
  • Type: Article
  • Identifier: vital:6529 , http://hdl.handle.net/10962/d1005970
  • Description: Little is known about pollination of the Aizoaceae (Mesembryanthemaceae). There are sparse reports of generalist pollination in the family by a variety of insects (predominantly bees). Furthermore, most species are self-incompatible in cultivation. In this study, observations were made on two populations of Bergeranthus multiceps (Salm-Dyck) Schwantes growing in the Eastern Cape province of South Africa. Insects visiting the flowers were collected and examined for pollen. While 79 individual insects (in 24 genera representing 14 families and four orders) were collected visiting the flowers, the majority (43 individuals) were female Allodapula variegata bees (Apidae, subfamily Xylocopinae, tribe Allodapini)collecting pollen. All other bee visitors were also female, suggesting pollen collection as the primary activity at the flowers. The protandrous flowers were found to be self-incompatible, pointing to the importance of bee-mediated xenogamy in this species. The flowers of B. multiceps are bright yellow in the human visual spectrum. In addition, the petals of this species reflect ultraviolet light. In contrast, the yellow anthers absorb UV. Flower opening and closing is common in the Aizoaceae. Interestingly, in B. multiceps flowers open at about 15:30 and remain open for approximately three hours before closing again in the late afternoon. These afternoon flower opening events were found to be closely correlated to ambient temperatures above 23°C, relative humidity lower than 50% and vapour pressure deficit below 1.05 kPa measured from as early as 09:00 on the days when flowers opened.
  • Full Text:
  • Date Issued: 2004
  • Disclaimer
  • Privacy
  • Copyright
  • Contact