Refractive laser eye surgery is a specialised field in ophthalmology which aims to correct the refractive disorder of an eye. The most established technique is LASIK, which has shown good results for the treatment of simple myopia. Complex refractive disorders, such as compound myopic astigmatism, have shown less predictable refractive outcomes, and in some cases the severe over- or under-correction can even worsen the preoperative situation and damage the eye. In its first stage, this research aimed to develop a software system able to present and analyse refractive outcomes. Over 2 prototype stages, this research has led to an operational system named IBRA (Internet Based Refractive Analysis), offering web-based data collection and refractive and vector analysis. In a second stage, Nomogram calculation formulas were developed and integrated into IBRA. These formulas were created from linear regression and best-fit analyses of spherical and cylindrical outcome data stored in IBRA. The purpose of the nomogram calculations was to provide surgeons with adjustment factors that could be used to improve the refractive outcome of patients with complex refractive disorders. Two extensive clinical audits and a randomized controlled trial were performed at Moorfields Eye Hospital to evaluate the IBRA nomogram adjustments. This research showed that IBRA was able to achieve a positive health change. In addition, results from the audits and trial contributed to the knowledge of nomogram adjustments and provided a framework in which future investigations on nomogram and treatment modifications could be performed. In addition to the above clinical studies, two evaluations were performed with the use of IBRA and data logging techniques to investigate users‟ behaviour relating to the management of data entry processes and the use of analysis functions. This research revealed the best method for entering refractive data, and was able to identify the most important analysis methods. Finally, the use of IBRA and its user-interface were investigated with a user satisfaction survey. The results from this questionnaire based study showed a high acceptance of the web-based platform of IBRA and indicated points for improvement (Documentation).

Glaucoma is a leading cause of irreversible blindness and visual impairment. In the clinic, glaucomatous damage can be characterized by structural changes in the optic nerve head (ONH) and retinal nerve fibre layer (RNFL) that can be evaluated by various retinal-imaging techniques such as scanning laser polarimetry and optical coherence tomography (OCT). The structural damage can lead to functional damage in the visual field (VF), normally assessed with standard automated perimetry, which assesses the differential light sensitivity in the field of view. The clinical measurements of retinal structure and visual function play an important role in the detection and management of glaucoma, but the data generated is often complex and highly variable, thus making it hard to clinically interpret. The purpose of this thesis was to investigate knowledge mining procedures for extracting clinically useful information from these measurements. Knowledge mining describes iterative divide-and-conquer type analyses of large-scale questions: solutions to individual smaller problems are used to generate better quality knowledge, which in the case of work reported in this thesis can be translated into clinically useful analysis tools. This thesis describes five knowledge mining procedures specifically developed and applied to structural and functional measurements in glaucoma: (1) probabilistic inference to aid image acquisition of OCT images; (2) a robust and efficient segmentation algorithm to extract features of retina tissue layer structures in large-scale 3-dimensional image volumes acquired by OCT; (3) a predictive structure-function relationship model to bridge the retinal structure and visual function measurements in glaucoma; (4) quantification and visualization of structure-function discordance using the model about structure-function relationship; (5) integration of structural and functional measurements to improve the reproducibility of the measurements. In conclusion the knowledge mining approaches improved the acquisition and/or accuracy of the measurements and provide new clinical analysis tools to detect and manage glaucoma.

Human skin colour has significant aesthetic and cultural implications. Cutaneous injuries can result in dys-pigmented scars which are more noticeable, aesthetically unpleasant, and can lead to patient distress and social isolation. Management of dys-pigmented scars has been challenging with variable success. There is a limited understanding of the timing, progression and mechanisms of skin re-pigmentation following wounding. This thesis is a detailed sequential study, which describes and quantifies scar colour changes in pigs of different pigmented strains.The first result chapter describes the observational pigmentary changes in scars of four different pigmented pig strains (Hampshire, Yucatan, Tamworth and Duroc) over time. Two scar re-pigmentation progression patterns, specific to the darkly and the lightly pigmented pigs, are identified and all scar photographs of all pigs at all time-points are scored during non-invasive wound/ scar monitoring using a semi-quantitative scale. In the second result chapter, histo-chemical (DOPA-oxidase) staining was combined with immuno-histochemistry (HMB45) to establish the spatial and temporal distribution and activities of melanocytes in the regenerated epithelium of darkly pigmented pig strains. Results suggest a rise in both inactive and active melanocyte numbers in re-pigmenting scars at early time-points and by late time-points, scars achieved ‘complete re-pigmentation’ and melanocyte numbers were lowest. Late melanocyte proliferation was observed in two scars from two different pigs; one of which manifested this as hyper-pigmentation, macroscopically. In addition, histological analysis of the epidermal melanin staining (Warkel-Luna-Helwig) pattern showed good correlation with the macroscopic appearance of the scars. The effect of changes in scar basement membrane undulation on melanocyte packing density was investigated: changes were small and unlikely to impact melanocyte packing density; hence macroscopic scar colour. Macroscopic and microscopic observations of the pattern of re-pigmentation following creation of partial thickness wounds across the white and black belts of three Hampshire pigs were investigated.The final result chapter describes how colour changes were quantified for scars and normal skin of each pig, at all time-points during non-invasive scar monitoring; using a reflectance spectrophotometer. In addition, the sensitivity of objective colour measurements was investigated. Results using two statistical clustering techniques suggest that colour measurements differentiate scars from the surrounding normal skin and the tristimulus L*a*b* values of scars correlate well with their macroscopic colour appearances. Time-dependent colour changes in scars and normal skin were quantified independently, using polynomial analysis. The results suggest systematic colour changes in most scars of all pig groups, except Yucatans’, which on the other hand, showed systematic colour changes to their normal skin. These findings highlight the importance of independent analysis of scar and normal skin colour measurements with time post wounding. In conclusion, this thesis has investigated timing and progression patterns of scar re-pigmentation in pigs of different pigmented strains.

Age-related macular degeneration and diabetic retinopathy, in which the cells at the back of the eye degrade due to age and diabetes respectively, are prevalent causes of vision loss in adults. We formulate mathematical models of retinal metabolic regulation to investigate defects that may be responsible for pathology. Continuum PDE models are developed to test whether rod photoreceptors, light detecting cells in the eye, may regulate their energy demand by adapting their length under light and dark conditions. These models assume photoreceptor length depends on the availability of nutrients, such as oxygen, which diffuse and are consumed within the photoreceptor. Our results suggest that the length is limited by oxygen and phosphocreatine shuttle-derived ATP under dark and light conditions respectively. Parameter sensitivity analysis indicates that lowered mitochondrial efficiency due to ageing may be responsible for the damage to and death of photoreceptors that are characteristic of age-related macular degeneration. In the latter part of this thesis we shift our focus to the inner retina and examine how metabolite levels in the tissue surrounding the neurons (highly sensitive, excitable cells that transmit electrical signals) are regulated by glial cells. For instance, stimulated neurons activate their neighbours via the release of the neurotransmitter glutamate, while glial cells regulate neuronal activity via glutamate uptake. Diabetes produces large fluctuations in blood glucose levels, and eventually results in neuronal cell death, causing vision loss. We generate an ODE model for the exchange of key metabolites between neurons and surrounding cells. Using numerical and analytical techniques, we use the model to show that the fluctuations in blood glucose and metabolic changes associated with diabetes may result in abnormally high glutamate levels in the inner retina, which could lead to neuronal damage via excitotoxicity (unregulated neuronal stimulation).

Uveal melanoma (UM) is the most common intraocular malignancy in adults. Despite successful ocular treatment, about 50% of patients succumb to metastatic dissemination, which occurs haematogenously and mainly affects the liver. On the basis of clinical, histopathological and genetic features of the primary tumour it is possible to predict if the individual patient is at high risk (HR) or low risk (LR) of developing metastases. However, the mechanisms responsible for the development of metastatic disease in UM are still largely unknown; therefore no adjuvant treatment is currently offered to HR patients to prevent development of fatal disease. As the time to discovery of clinically detectable metastases can range from months to decades, a secreted biomarker(s) that could be routinely tested in blood is much needed. The scope of the work presented in this thesis was to use proteomics as a tool to identify potential novel, UM-specific biomarkers. Moreover, the proteomic data acquired would complement genomic and transcriptomic information already generated by the Liverpool Ocular Oncology Research Group, with the ultimate aim of increasing our understanding of UM development and dissemination. The aim of Chapter 2’s project was to compare the proteome of UM tissue samples at HR versus LR of developing metastatic disease using isobaric tags for relative and absolute quantitation (iTRAQ) labelling and mass spectrometry (MS). The quantification of proteins in our samples, proteomic analysis and further validation by immunohistochemistry has led to the identification of two novel prognostic and potentially therapeutic target, S100A6 and the tumour suppressor PDCD4. In Chapter 3 we focused on proteins released in the conditioned medium (secretome) of short-term cultures of HR and LR UM cells, as well as normal melanocytes. Using a label-free quantitative proteomic approach, almost 2000 proteins were identified and quantified, with more than 30% of these identified as secreted and/or previously described in exosomes. Using these data, an 18-protein signature able to discriminate between HR and LR UM was identified. Further validation will be necessary in secretome samples and in the peripheral blood of UM patients, but this has the potential of being translated into a clinically useful assay to detect early development of metastatic disease. As reported in Chapter 4, we also conducted a pilot clinical study on circulating tumour cells (CTC) in UM, using the CellSearch® platform with the novel melanoma kit to enumerate CTC in the peripheral blood of UM patients at LR, HR or with overt metastatic disease. CTC were detected in metastatic and HR tumours and were not present in LR UM, however, the number of CTC detected varied widely, calling into question the clinical value of using this platform in UM patients. The research detailed in Chapter 5 had a direct clinical value, as it addressed the procedures undertaken during the acquisition and processing of prognostic biopsies from UM tumours treated conservatively. The modifications introduced led to a significant improvement of the success rate of such prognostic biopsies for risk stratification, which is essential for clinical management, follow-up and research purposes. In conclusion, the work conducted throughout this PhD has provided further insight into the molecular characteristics that can differentiate between HR and LR UM, identifying novel potential biomarkers that will need validation in the clinical setting.

This dissertation addresses the loss of definition of public spaces within the urban enviroments due, in large part, to increased privatisation. Using the Baixa of the city of Maputo, Mozambique as its laboratory, the alienated amd abandoned spaces within the urban fabric which result in these voids will be explored. Critical theory relating to the manner in which we appropriate and define sapces within our urban enviroment will be explored as this dissertation seeks to establish a connection between the architectural realm and its surrounding public landscape. An architecture which explores the reconnection of place to space will be saught through the investigation f the series of thresholds that occur between the two. Specifically, this exploration will be through the lens of the adaptive re-use of a historically significant landmark within the urban core and its ability to be re-integrated into a contemporary urban landscape. / Dissertation (MArch(Prof))--University of Pretoria, 2011. / Architecture / unrestricted

Re(hfac)₃ has been found to crystallize in a hexagonal unit cell but the detailed structure has not been completed because of disordering problems along the c axis. The two-dimensional structure of Re(hfac)₃ reveals C₃ symmetry and no distortion of the octahedron composed of the six Re-O bonds. Re(acac)₃ has been found to belong to the α-type isomorphous set designated by Astbury. From x-ray powder photographs, the structure of Re(acac)₃ has been demonstrated to have the same gross structural features as Mn(acac)₃ but is not necessarily isostructural. Arguments are presented to show that β-V(acac)₃ is representative of the β-modification and that the β-type isomorphous set crystallizes in a monoclinic unit cell with a β-angle of 90º. Rotational transitions between the three isomorphous sets have been examined and found to be energetically unfavourable. / Thesis / Master of Science (MSc)

Submitted by Suelen Reis (suziy.ellen@gmail.com) on 2013-04-08T17:20:36Z No. of bitstreams: 1 feridasurbanasseg.pdf: 14259703 bytes, checksum: 769bebec8f632c51ffc3b494a4467a05 (MD5) / Approved for entry into archive by Lêda Costa(lmrcosta@ufba.br) on 2013-04-18T12:27:15Z (GMT) No. of bitstreams: 1 feridasurbanasseg.pdf: 14259703 bytes, checksum: 769bebec8f632c51ffc3b494a4467a05 (MD5) / Made available in DSpace on 2013-04-18T12:27:15Z (GMT). No. of bitstreams: 1 feridasurbanasseg.pdf: 14259703 bytes, checksum: 769bebec8f632c51ffc3b494a4467a05 (MD5) Previous issue date: 2008 / A presente dissertação aborda aspectos relacionados com apropriações de formas encontradas em ruínas urbanas, nos muros, passeios e fachadas da Cidade de Salvador, bem como os procedimentos técnicos e operacionais para a sua remoção e desconstrução. A interface de interação urbana resultou em formas selecionadas e posteriormente trabalhadas através da gravura, utilizando-se de matriz xilográfica e serigráfica, desenvolvidas a partir do concreto e do isopor, formando objetos e imagens por camadas de impressão. O amplo emprego das feridas urbanas deslocando-as para o espaço interno da galeria e (re)significando-as através dos objetos visuais, fez uma analogia entre o corpo humano e a cidade, como signos presentes no concreto deste revestimento que é o corpo social. As investigações destas formas encontradas no território urbano geram uma poética, baseada em elementos e materiais, com significados diversos e aspectos plásticos conceituais a partir de princípios formativos para a construção da obra de arte; sustentados principalmente, por conceitos de filósofos e pensadores como Gaston Bachelar, Giulo Carlo Argan, De Fusco, Nelson Brissac Peixoto, Fayga Ostrower e Luigi Pareyson. / Salvador

Denna studie syftar till att skapa förståelse för hur avgående yrkesofficerares möjligheter till en reengagering i Försvarsmakten kan öka. Arbetsmarknaden präglas i dag av en personell rörlighet mellan företag och organisationer samt de individuella kraven på utvecklingsmöjligheter och meningsfullhet är höga. Om en organisation kan anpassa sig till dessa förhållanden kan en återbetalning i form av ny kompetens och engagemang komma att ske genom reengagering. Med reengagering menar vi en avgående yrkesofficer som åter tjänstgör i Försvarsmakten som tidvis tjänstgörande reservofficer, tjänstgöring i internationell tjänst, eller åter som kontinuerligt tjänstgörande yrkesofficer.Studiens resultat visar att validering av civil kompetens, tillgängliggörande av lediga yrkesofficersbefattningar och ett positivt avslut på en anställning ökar möjligheterna till en reengagering. Att erbjuda reservofficersavtal, tillgång till ett personligt nätverk eller medlemskap i alumninätverk vid avgången ökar möjligheterna ytterligare. Andra faktorer som ökar möjligheterna är personlig och dynamisk arbetsgivarkontakt samt att på ett personligt plan erbjuda anställning. Slutligen, och inte minst, ser vi att individens starka identitetskänsla som yrkesofficer i Försvarsmakten är en central och attraherande faktor: En gång officer - alltid officer!Denna kvalitativa, intervjubaserade och induktiva studie bidrar till ökad förståelse för faktorer som påverkar en återanställning i en försvarsmaktskontext. Studien bidrar vidare till ökad förståelse för de kulturella band som en organisation och dess deltagare kan ha till en individ och hur banden kan få individen att återvända till sin tidigare arbetsgivare. / This study aims to create an understanding of how, military officer´s departing, possibilities for re-engagement could be strengthened. Today’s labor market is incused by high movement of personnel between organizations and by high individual demands on potentiality and meaningfulness with employment. If an organization manages to adapt to these circumstances it could enjoy a refund in new knowledge and dedication that comes with a re-engagement. With a re-engagement we refer to a former military officer who, now working outside the Armed Forces returns to continuous service, international service or occasional service.The results of the study show that validating civil competence, making available jobs visible and searchable, and striving for a positive departure when quitting, increases the possibilities for a re-engagement. When offered an opportunity to serve as an officer in the reserve and given access to an alumni network when quitting, possibilities for a re-engagement increases further. Additional factors that strengthen possibilities are personal and dynamic working relations and personally addressed job offers. Finally, but not least, the strong sense of identity that is inherent with military officers is a fundamental and attractive factor: Once an officer – always an officer!This qualitative, interview based and inductive study contributes to increased knowledge on factors that have an impact on re-engagement in a military context. The study further increases understanding of cultural ties between an organization and individuals and how these ties may affect a person's choice to return to a former employer.

Wireless Sensor Network consists of tens or thousands of sensor nodes scattered in a physical space and one or more Base stations or Sinks. Even thought developed for military applications now they find a wide variety of civilian applications also. Some of the applications are Target tracking, Animal monitoring, Vehicle monitoring. The need (or lack thereof) for reliability in a sensor network is firmly dependent upon the specific application the sensor network is used for. Some applications like re-tasking or reprogramming sensor nodes [upgrading software or algorithms, adding codes, scripts etc] over -the-air requires assured delivery of high-priority events to sinks. We believe that as the number of sensor network applications grows, there will be a need to build more powerful general-purpose hardware and software environments capable of reprogramming or retasking sensors to. / Wireless sensor network is a special form of wireless networks dedicated to surveillance and monitoring applications Reliability in wireless sensor network is application specific. The specific form of reliability might change from application to application. Our idea is to generate reliability based transport protocol that is customizable to meet the needs of emerging reliable data applications in sensor networks and is also adaptive when the nodes are mobile. In our approach, clusters are formed for minimizing energy dissipation. The nodes maintain a neighbor list to forward data and any changes in the local topology can trigger updates to a node’s neighbor list. If a node notices that its neighbor list has changed, it can spontaneously re-advertise all of its data thus providing reliable transport in mobility conditions also. Our approach has five phases-setup, relaying, relay initiated error recovery, selective status reporting and node supervising. Our simulation results prove that the proposed approach can outperform existing related techniques and is highly responsive to the various error and mobility conditions experienced in sensor networks.