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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Paranoid metaphors: an examination of the discursive, theoretical, and sometimes personal, interaction between the psychoanalyst, Jacques Lacan, the surrealist, Salvador Dali, and the English poet, David Gascoyne

De Klerk, Eugene January 2003 (has links) (PDF)
This thesis examines the historical interaction of the psychoanalyst, Jacques Lacan, the surrealist, Salvador Dali, and the English poet, David Gascoyne. It traces the discursive, and sometimes personal, relationship between these figures which led to a psychoanalytic-based conception of paranoia that impacted on both surrealism and the surrealist-inspired poetry and theory of David Gascoyne. Furthermore it seeks to identify the potential ramifications of this conception of paranoia, and the artistic practice it engendered, for literary, Marxist and psychoanalytic theory.
62

Towards reconciliation of structure with function in plasmodesmata—who is the gatekeeper?

Botha, C.E.J., Cross, R.H.M. January 2000 (has links) (PDF)
Whilst the structure of higher plant plasmodesmata was first described by Robards (1963. Desmotubule—a plasmodesmatal substructure. Nature 218, 784), and despite many subsequent intensive investigations, there is still much that remains unclear relating to their ultrastructure and functioning in higher plants. We have examined chemically fixed plant material, and suggest that the conformational changes seen in plasmodesmatal substructure, particularly the deposition of electron-dense extra-plasmodesmal material, is linked to either manipulation of the hormonal balance (as in Avocado fruit), or of osmotic potential in leaf blade material. These changes result in the deposition of β 1,3-glucan (callose) at the neck region of these plasmodesmata. This electron-dense material is deposited at the neck region of plasmodesmata, and forms a collar-like structure. The formation of a collar is shown to be coupled with loss of lucence within the cytoplasmic sleeve. The formation of a collar at the plasmodesmatal orifice thus results in encapsulation and closure of the plasmodesmatal orifice. Closure of the orifice coincides with a loss of electron-lucence and a lack of resolution of the desmotubule. These ultrastructural changes are potentially significant and could contribute to, result in, or assist in the down-regulation of cell to cell trafficking via plasmodesmata.
63

Reduction in transport in wheat (Triticum aestivum) is caused by sustained phloem feeding by the Russian wheat aphid (Diuraphis noxia)

Botha, C.E.J., Matsiliza, B. January 2004 (has links) (PDF)
The Russian wheat aphid (Diuraphis noxia) feeds preferentially from the phloem of longitudinal veins of nonresistant wheat leaves. The xenobiotic, 5,6-CFDA was applied to exposed leaf blade mesophyll cells in control and aphid-infested plants. In control plants, the fluorophore moved approximately 5–6cm from the point of application of 5,6-CFDA within 3h of application. The fluorochrome was transported in the sieve tube companion cell complex, including those in the numerous interconnecting transverse veins. Leaf blades on which the Russian wheat aphid had been feeding demonstrated a marked decrease in 5,6-CF transport. Aphids feeding on the leaves formed local sinks and redirected the fluorophore (and presumably associated assimilate) to the aphids’ gut, with little longitudinal translocation of 5,6-CF below inserted stylets or aphid feeding areas. Aniline blue staining revealed massive deposits of wound and reaction callose caused by the aphids, with callose associated with the sieve plates, pore-plasmodesma between the companion cells and their associated sieve tubes, as well as with plasmodesmal aggregates in parenchymatous elements within the vascular bundles. Leaves that had been colonised by aphids but from which the aphids were removed, showed extensive wound callose deposits, which persisted for up to 48h after removal of aphid colonies, suggesting that the damage caused by aphid feeding is a long-term, non-transient event in non-resistant plants.
64

Teachers' beliefs regarding the role of extensive reading in English language learning: a case study

Kajinga, Gilford January 2006 (has links) (PDF)
Research suggests numerous views to account for the influence on practice of teachers’ beliefs. One view states that teachers’ lived experiences shape their beliefs about practice. Another view attributes the influence to school experiences. This research sets out to gain insight into teachers’ beliefs on the role of extensive reading in second language learning. A case study of 9 teachers from 3 schools in Grahamstown, South Africa selected purposefully and conveniently was utilised. The teachers were viewed to be knowledgeable on this matter by virtue of their profession while the 3 schools were selected to represent a private school, a former Model C and former Department of Education and Training (DET) school. Data was mainly collected by means of semi-structured interviews, which utilised in-depth open-ended questions to yield teachers’ past experiences. The findings revealed the following: all the teachers appeared to believe that extensive reading was invaluable and enhanced language skills. However, white and black teachers differed in terms of their early experiences of reading. Whereas for white teachers early experiences with literacy were encountered in the home, for black teachers the school was where they had their first exposure to literacy. In addition formal training in the form of an ACE (Advanced Certificate in Education) seemed to have influenced black teachers’ beliefs about the subject at hand, whereas the role of teacher education/ training was not as significant for white teachers.
65

Aspects of the sentencing process in child sexual abuse cases

Van der Merwe, Ivy Annette January 2006 (has links) (PDF)
This thesis investigates current sentencing practices relating to the diverse, complex and emotionally laden phenomenon of child sexual abuse. It focuses on relevant legislative provisions, on case law and on an empirical study conducted amongst regional court magistrates. Trends, developments and problems are analysed and possible solutions to the main problems identified are investigated. The thesis concludes with proposed guidelines regarding the sentencing process in child sexual abuse cases. Such guidelines address general and specific principles, the use of victim impact statements, the increased recognition and use of behavioural science in the sentencing phase with regard to both the victim and the offender, and relevant aggravating and mitigating factors. The guidelines are an attempt to give some structure to the current haphazard approach adopted by the courts with regard to harm experienced by the victim. They are also aimed at assisting experts to provide more effective and reliable pre-sentence reports. Further, the thesis attempts to provide clarity concerning the factors that are considered to be aggravating or mitigating in the offence category, child sexual abuse, as well as with regard to the weight that should be attached to them. In addition, recommendations are made for the purpose of possible law reform and further research in relation to the regulation of judicial discretion through the introduction of formal sentencing guidelines, victim impact statements and the accommodation of behavioural science in the sentencing process pertaining to sexual offenders. This proposal is based on current South African sentencing practices as reflected in the consolidation of local judgments scattered over many years in different law reports and, to some extent, on English, Canadian, Australian and American sentencing practices as researched in this study.
66

Feeding ecology, space use and habitat selection of elephants in two enclosed game reserves in the Eastern Cape Province, South Africa

Roux, Candice January 2006 (has links) (PDF)
The development of small (<300 km²), private game reserves has become a trend, not only in the Eastern Cape Province, but also elsewhere in South Africa as a result of a shift in land use practise from agriculture to ecotourism. The resultant re-introduction of elephants to many of these reserves has lead to management concerns because of the limited research on small reserves regarding their impact on the vegetation. In this study I assessed the space use, habitat selection, diet and impact of two elephant populations on the vegetation in the Eastern Cape Province between February 2004 and March 2005. Home range sizes were calculated using the kernel utilization distribution method. Home range sizes for elephants on Kwandwe were significantly larger during summer than winter (p<0.05). There was no significant difference between the home range sizes of the herds and males within a season and during summer the elephants utilized about 75 % of the reserve and only 54 % during winter. On Shamwari, the herd utilized about 92 % of the reserve during summer and 83 % during winter; while the males utilized 76 % of the reserve. Core areas for both elephant populations shrank from summer to winter and were concentrated around the permanent water sources on each reserve. Habitat selection was assessed using χ² tests and Bonferroni confidence intervals. On Kwandwe, there was a significant difference between observed and expected use of vegetation types (p<0.05) and karroid shrubland was strongly avoided by both herds during summer and winter. The preferred vegetation types of the males ranged from relatively open (short euphorbia thicket, bushclump karroid thicket and karroid shrubland) to completely open (old lands). On Shamwari, subtropical thicket, bontveld and montane grassland were avoided; while primary and secondary acacia thicket, riverine thicket and cultivated lands were preferred. The predominant vegetation type in the home ranges of herds on Kwandwe and Shamwari was subtropical thicket. The diet was assessed by direct observations over two seasons and dietary preferences were calculated. There was a significant difference in the frequency of occurrence of plants in the diet on the two reserves (p<0.05) and no significant effect of time of day or season (p>0.05). Seventeen woody plant species were utilized on Kwandwe and 23 species were utilized on Shamwari. Grass constituted a significantly greater percentage of the diet in summer than winter (p<0.05). Elephants on Kwandwe showed a selective preference for Ozoroa mucronata, Pappea capensis and Acacia karroo; while on Shamwari, A. karroo was selected. Transects were conducted in two different vegetation types on each reserve so as to assess the impact of elephant on the vegetation and damage scores were then calculated from these data. There was no significant effect of vegetation type or elephant density on mean damage scores in Kwandwe (p>0.05). Five hundred and seventy-eight plants were assessed in the subtropical thicket vegetation type and 225 plants were assessed in the savanna-type vegetation, with more than half the trees showing low levels of damage that could not only be attributed to elephants. Mean damage was highest for Portulacaria afra and Pappea capensis in subtropical thicket and for Rhus spp. in the savanna-type vegetation. On shamwari, 408 plants were assessed in subtropical thicket and 215 in the savanna-type vegetation, with more than 70 % of trees showing low levels of damage. There was a significant effect of plant species and elephant density on the mean damage scores in subtropical thicket, with Aloe ferox showing more damage than the other plant species (p<0.01). In the savanna-type vegetation, A. karroo was the most severely damaged. Overall, damage was greater in the thicket vegetation type compared to the more open vegetation type on both reserves.
67

Late glacial and holocene palaeoclimatology of the Drakensberg of the Eastern Cape, South Africa

Lewis, C.A. January 2005 (has links) (PDF)
Eight climatic events during the Holocene are evidenced in the East Cape Drakensberg by fluvial, archaeological and palynological deposits. Flood plain deposition under relatively moist conditions occurred in the Early Holocene, before ca. 7000 BP. Semi-arid conditions with limited fluvial activity dominated the Mid Holocene until ca. 3200 BP. Alternating flood plain erosion and deposition occurred in the Late Holocene. Four climatic events, for which there is palynological and limited archaeological evidence, have been identified in the Late Glacial.
68

Radiocarbon dates and the Late Quaternary palaeogeography of the Province of the Eastern Cape, South Africa

Lewis, C.A. 03 1900 (has links) (PDF)
A total of 193 dates are listed from the Eastern Cape. Middle Stone Age hunter-gatherers existed in the Drakensberg prior to the rigours of cold climatic conditions after ca. 22,000 BP. These uplands were reoccupied under more favourable climatic conditions after ca. 12,600 BP but were apparently abandoned between ca. 6000 BP and 3000 BP. Hunter-gatherer occupation throughout the Holocene is indicated at lower altitudes, with in-migration of pastoralists ca. 1800 BP in the Fish River area, and with Iron Age farmers entering coastal districts and adjacent river valleys from ca. 1400 BP. Sand dunes accumulated in the Holocene adjacent to the Indian Ocean. Flood plain development in the early Holocene was succeeded by incision of rivers in the later Holocene. Flood plain deposition began again in the Southern Drakensberg ca. 1000 BP. Palynological studies evidence marked climatic oscillations around the Late Glacial/Holocene boundary, with apparent stability at high altitude subsequent to 2700 BP.
69

Protalus ramparts and the altitude of the local equilibrium line during the last glacial stage in Bokspruit, East Cape Drakensberg, South Africa

Lewis, C.A. January 1994 (has links) (PDF)
A ridge of unconsolidated debris at an altitude of 2000 m, located beneath cliffs in the East Cape Drakensberg of South Africa, is interpreted on morphological and sedimentological evidence as a protalus rampart. The rampart is believed to have formed in the Bottelnek Stadial, after 27 000 BP and before 13 000 BP, and provides evidence of perennial snowbeds and at least discontinuous permafrost in the East Cape Drakensberg during that Stadial.
70

The South African sugar industry

Lewis, C.A. 03 1900 (has links) (PDF)
The sugar industry was established in Natal in the mid-nineteenth century. By the 1980s, South Africa produced c. 2 million metric tons of sugar per annum and, directly or indirectly, the industry supported almost one million people. Exports, which amounted for almost half the sugar produced in the 1970s, declined during the 1980s and low prices together with American and Canadian sanctions have forced the industry to consider alternative uses for sugar cane.

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