Keratan sulfate (KS) is an elongated glycosaminoglycan (GAG) chain found throughout the cornea, the clear tissue at the front of the eye. It is thought that KS plays a specialized role in maintaining the ordered spatial arrangement of collagen fibrils that comprise the thickest layer of the cornea, the stroma. Repeating N-­‐acetylglucosamine (GlcNAc) and galactose monosaccharides make up the fine structure of KS, and sulfate groups frequently modify their C-­‐6 positions. Recent studies have linked improper sulfation of GlcNAc residues to macular corneal dystrophy, a vision condition characterized by a progressive loss of corneal transparency. Since then, in vitro experiments have implicated four enzymes in highly sulfated KS biosynthesis. It is currently believed that β-­‐1,3-­‐N-­‐ acetylglucosaminyltransferase 7 (β3GnT7), corneal GlcNAc 6-­‐O sulfotransferase (CGn6ST), and β-­‐1,4-­‐ lactosyltransferase 4 (β4GalT4) sequentially catalyze the addition of GlcNAc, transfer sulfate to its C-­‐6 position, and link galactose to the growing KS backbone, respectively. The fourth enzyme, KS galactose 6-­‐O sulfotransferase (KSGal6ST) is thought to act last, sulfating galactose residues. Mutant mice deficient in CGn6ST, KSGal6ST, or β3GnT7 were recently developed to investigate the consequences of dysfunctional sulfo-­‐ or glycosyltransferases on corneal morphology. Electron microscopy and immunohistochemistry data in this thesis showed that the systemic absence of CGn6ST or β3GnT7 resulted in a corneal stroma devoid of KS, but mutation of only KSGal6ST led to a KS phenotype similar to that of wild type controls. Western blot analysis conducted on β3GnT7-­‐null corneas indicated that KS assumed an unusually truncated form, as compared to wild type controls. A secondary result evident in electron micrographs was that in cases where KS levels dropped below the detectable threshold (i.e. in CGn6ST and β3GnT7 mutant corneas), a concurrent appearance of atypically elongated GAGs was visible, suggesting a compensatory mechanism to preserve corneal organization. Since the unusual GAGs were susceptible to chondroitinase ABC digestion, it is thought they are comprised of chondroitin/dermatan sulfate (CS/DS). Studies using high performance liquid chromatography were also undertaken to establish protocols in which future work could quantify the change in CS/DS expression observed in CGn6ST and β3GnT7 mutant corneas.

It has been demonstrated repeatedly, over a period of many years that some animals can perceive magnetic field parameters and use this sensory information to their advantage. The sensory mechanisms involved are, however, still poorly understood. Due to a general lack of understanding of magnetoreception and its properties, experiments to date have been somewhat disjointed with many, often very different, investigative approaches being employed. As a result, direct corroboration of results is uncommon and progress is often slow. Advancement of this field is important for numerous reasons, such as improving knowledge of factors affecting animal migration in a time of concern over climate change and the possible imminent change in earth’s magnetic field parameters. Perhaps most significantly, such studies might provide a potential keystone in the study of the function of quantum mechanical processes in biological systems. The current study utilises a novel approach, designed to ensure improved reproducibility. Reported here for the first time, prepulse inhibition of a startle response is used to investigate magnetoreception in the homing pigeon (Columba livia). This powerful, well-characterised paradigm relies on reflexive behaviours and therefore ensures an objective method for demonstrating the perception of a stimulus. Visual psychophysics and polarised light vision are also explored. Proof of concept is provided for the use of prepulse inhibition to investigate magnetoreception. The value of using liquid crystal displays in an investigation of pigeon head movements, in magnetoreception and more generally, is demonstrated. A new, low invasiveness technique for tracking head movements is described. The need to eliminate anthropogenic electromagnetic signals in order to carry out reliable magnetoreception experiments is highlighted. Suggestions are also made regarding possible future directions of research in this area.

Glaucoma is an optic neuropathy characterised by the loss of retinal ganglion cells (RGC). Dendritic atrophy occurs early in the disease, prior to soma and axonal degeneration. RGCs exhibit reduced branching density and dendritic field size. This thesis seeks to further characterise dendritic atrophy in glaucoma in the context of two external factors that may contribute to the disease pathology – immune system effects mediated via complement and the influence of the perineuronal net (PNN), a specialised extracellular matrix that surrounds RGCs. RGC morphology was investigated in a rat bead model of experimental glaucoma using ballistic labelling techniques; morphological changes were related to synaptic loss and PNN composition using immunohistochemistry. A model was derived for the classification of diseased RGCs in order to prevent labelling bias in subsequent investigations. The immune system was modulated using a complement inhibitor (using a transgenic mouse and pharmacological agent in rats) and PNNs disrupted using the bacterial enzyme Chondroitinase ABC. Experimental glaucoma caused significant dendritic loss, with partial protection conferred by both complement inhibition and PNN digestion. Analysis of retinal sections also revealed partial protection of synapses. PNNs did not show any changes in their composition in the rat in experimental glaucoma but human glaucoma eyes showed increased glycosaminoglycan sulphation in the RGC layer which was correlated with visual deficit. Manipulation of the RGC external environment therefore proved successful in protecting from dendritic atrophy.

The purpose of this thesis was to assess long-term outcomes of the visual dysfunction arising from the ocular toxicity associated with the anti-epileptic drug vigabatrin (VGB). The risk of vigabatrin-associated visual field loss (VAVFL) with increasing exposure to VGB was modelled from retrospectively collected data from a cohort of 147 individuals (median exposure 7.9 years; IQR 3.6, 11.0). The modelled frequency of VAVFL increased with increasing exposure and plateaued at 75-80% after approximately 6 years duration and 5kg cumulative dose. The relationship between the numbers of retinal ganglion cell soma and axons, derived by standard automated perimetry and time-domain optical coherence tomography (TDOCT), respectively, was evaluated in 24 individuals with VAVFL and in 16 exposed to vigabatrin but with normal fields (VGBN). A strong linear association was present between the two outcomes, which was suggestive of an optic neuropathy, and was similar to the association for a control group of 18 individuals with open angle glaucoma. A follow-up visual field, after a median interval of 7.0 years (IQR 6.5, 7.6) was determined in 19 individuals with VAVFL and in 8 with VGBN, after a median withdrawal from VGB of 7.1 years (IQR 5.4, 8.4). No consistent trend was noted for either a deterioration or improvement in the field. A follow-up scan of the peripapillary retinal nerve fibre layer (RNFL) thickness, by TDOCT, after a median interval of 6.5 years (IQR 5.8, 6.9) was obtained in 13 individuals with VAVFL and in 4 with VGBN, after a median withdrawal from VGB of 8.0 years (IQR 5.3, 10.2). No consistent trend was noted for either a deterioration or improvement of the RNFL thickness. The macular thickness was evaluated by TDOCT in 32 individuals with VAVFL and in 14 with VGBN. No difference in thickness was noted between the two groups.

: Infantile nystagmus (IN) is a pathological condition of continuous, horizontal eye oscillations. Despite ongoing eye movements, those with IN do not experience oscillopsia, i.e. the illusory perception that the environment is moving to-and fro. The correct use of neural compensation for their eye movements, just as in typical individuals, is hypothesised to account for this lack of oscillopsia. This neural mechanism requires that an estimate of eye velocity (‘extra-retinal signal’) be compared to an estimate of the motion of the retinal image (‘retinal signal’), and any difference due to object motion. Despite this hypothesis, there have been no previous investigations on how accurately those with IN can estimate object motion. Even in typical adults, eye movement compensation is not perfect, which underlies a number of pursuit-based illusions. One such illusion, the Filehne illusion can be used to investigate the relative mismatch between the extra-retinal and retinal signals as individuals judge their perception of stationarity while attempting to follow a moving target. This illusion was used to investigate, through comparison with typical individuals, whether those with IN correctly recover object motion. Experiments were conducted to characterise the ability of those with IN to fixate as well as follow targets, using a novel two-dimensional eye movement measure. Under repeated testing, the fixation gaze angle at which the IN oscillation is minimum (a null zone) was not consistent. Moreover, those with IN were unable to accurately or precisely follow targets using their slow phase. Results from a comparison of fixation and pursuit performance in those with IN suggested no difference in either the accuracy or precision. Importantly, the psychophysical judgements of those with IN pursuit eye movements are prone to similar compensation errors as typical controls. However, the mechanisms by which this is achieved will require further exploration.

This numerical study explored the mechanisms responsible for the re-initiation of a detonation, which quenched while diffracting over a half-cylinder obstacle. Its purpose was to accurately predict when detonation re-initiations occur, determine roles of re-initiation mechanisms, and compare effects of chemical models. The model used reactive Euler equations with the one-step Arrhenius or two-step chain-branching chemical models, calibrated to post-shock conditions to reproduce the ignition delay. Simulations were validated using the stoichiometric methane-oxygen experiments of Bhattacharjee et al.. The model accurately predicted detonation re-initiation conditions found in experiments with good qualitative and quantitative agreement. While the one-step model was sufficient in predicting re-initiation, the two-step model reproduced finer details. Kelvin-Helmholtz and Richtmyer-Meshkov instabilities did not appear to influence detonation re-initiation of the Mach stem. Detonation re-initiation occurred due to adiabatic compression of the Mach stem, or transport of a flame along the wall jet. Transverse detonations were poorly reproduced.

No description available.

This thesis aims to address the issues of corporate re-branding in the context of marketing strategy and general strategic management. The research for the thesis was conducted in Pietermaritzburg and the surrounding areas where the Amalgamated Beverage Industries (ABI) depot distributes the Coca-Cola brands and other alternative beverages. ABI distributes non-alcoholic beverages that are produced under the trademark of Coca-Cola to the wholesalers and retailers in the Pietermaritzburg Central Business District (CBD) and the surrounding townships and settlements. ABI embarked on a re-branding campaign that resulted in the redesigning of the company logo. From a strategic management point of view, new business strategies that are formulated aim at finding ways that will keep a company trading profitably for a long time. The re-branding process of ABI has resulted in a change of attitudes of both employees and management towards its customers. The overall aim of the thesis was to investigate the impact of re-branding on the profitability of the company ABI. The results of the thesis reveal that other variables play a role in promoting the profitability of a company. The investigation, through a comprehensive field and secondary survey, used both qualitative and qantitative methods in its data collection. Finally, the thesis has examined the implications of re-branding on the purchasing trends of ABI' s customers after having been exposed to the new ABI image and new culture of conducting business. It has been established after analysing both the primary and secondary data that it is not demonstrably obvious that when a company re-brands its logo or image, that customers will purchase more products, hence increasing the financial value of the company. It is the final conclusion and recommendation of this thesis that before engaging in a costly re-branding exercise, senior management should conduct proper market research as to whether the exercise will add financial value to the company. / Thesis (DBA)-University of KwaZulu-Natal, Westville, 2006.

86f. / Submitted by Suelen Reis (suziy.ellen@gmail.com) on 2013-05-17T12:49:50Z No. of bitstreams: 1 Dissertacao Ana Bicalho.pdf: 371392 bytes, checksum: e0826192558e6c312e59b2bd26e5452a (MD5) / Approved for entry into archive by Alda Lima da Silva(sivalda@ufba.br) on 2013-05-27T21:33:31Z (GMT) No. of bitstreams: 1 Dissertacao Ana Bicalho.pdf: 371392 bytes, checksum: e0826192558e6c312e59b2bd26e5452a (MD5) / Made available in DSpace on 2013-05-27T21:33:31Z (GMT). No. of bitstreams: 1 Dissertacao Ana Bicalho.pdf: 371392 bytes, checksum: e0826192558e6c312e59b2bd26e5452a (MD5) Previous issue date: 2007 / Este trabalho se insere nos Estudos de Tradução e propõe-se a investigar o processo de (re)criação dos tradutores do romance La Peste de Albert Camus, a saber, Graciliano Ramos e Valérie Rumjanek, a partir de uma perspectiva sistêmica e funcional. A base teórica e metodológica adotada é a Teoria do Polissistemas desenvolvida por Itamar Even-Zohar e os fundamentos dos Estudos Descritivos de Tradução que têm como principais representantes Gideon Toury, André Lefevere, José Lambert e Hendrik van Gorp. Foram discutidas, durante a análise, questões referentes ao cânone literário, à fidelidade e originalidade e à relação entre autor e tradutor destacando que um dos tradutores envolvidos é um autor já consagrado na língua de chegada. Em seguida, foi feita uma análise macro e micro-estrutural das traduções envolvidas e, por fim, o levantamento e análise dos aspectos semânticos e sintáticos das traduções encontradas, estabelecendo uma relação crítica com o texto de partida. A análise demonstrou as diferenças entre as traduções e como o contexto e a cultura influenciam no processo de (re)criação, além de apontar as principais opções tradutórias de Graciliano Ramos e Valerie Rumjanek que caracterizam seu estilo como tradutores. / Salvador

This thesis' main goal is to analyze the impact of forced exodus of German people from Uničov and its surroundings. The author does not want do describe the problem of Benes' Decrees, but the example of Moravian small town should illustrate theirs results. It briefly shows history of Czech and German colonization from medieval ages to the foundation of Czechoslovakia, then, as the basis for comparison, describes the economy, local politic trends and ethnic interaction between the World Wars and during German occupation. The main chapter focuses on Unicov in 5 years after World War II, the political situation, questions of the exodus and re-colonization of the region by Czech people from nearby, more distant areas of Czechoslovakia and even from 1 region of the USSR. It describes changes in agriculture, industry and entrepreneurship. All these sectors were somehow touched by the political change after year 1948. The study is based on older works of local historians, author's own research in archives, documents found in legacy and memories of the living elders.