No description available.

Cross-cultural exchange between individuals, both through face-to-face encounter and, more recently, electronic media, has been widely promoted as a means of educating against prejudice. Through the integration of structured field study, practical experience, educational and social theory, and contemporary philosophy, this thesis challenges the very foundations upon which such initiatives are built, and develops an alternative basis from which to approach cross-cultural exchange. An exploration of social categorisation posits the foundations of prejudice in essentialist conceptualisations, whether under the umbrella of universalism or relativism. The historical propensity for antiracist and multicultural education to reify group difference and reinforce such essentialist conceptualisations of identity thus presents an interesting conundrum. The fact that similar tendencies are noted in contemporary practice, educational resources, and official guidance, gives this more than an academic interest. Despite the apparent advantages of abandoning essentialist categorisations, studies of communication and identity formation reveal contradictory evidence - the need to locate others socially and to predict their behaviour accordingly, both in face-to-face and electronic communication. Thus, the challenge for educators is to develop innovative pedagogical approaches that translate contemporary, non-essentialist, understandings of group categorisation into workable practices to overcome inequality. While, within such a programme, cross-cultural exchange might be seen to have a valuable role to play alongside structural reform, it is clear that alone it cannot provide a panacea for prejudice. In the light of the above, the thesis addresses guidance for good practice in crosscultural exchange, and the related complexity of programme evaluation, alongside the training of future facilitators of such projects. A particular emphasis is placed upon the use of participatory arts and the unique tools this medium can bring to inclusive, cross-cultural collaboration. The thesis demonstrates, that cross-cultural exchange has the potential to provide valuable and significant learning experiences, some of which have previously been given little recognition.

Purpose: To examine the variables that influence lipid deposition on conventional and silicone hydrogel contact lens materials and to build a physiologically relevant in vitro model of lipid deposition on contact lenses. Methods: Lipid deposition on contact lens materials can lead to discomfort and vision difficulty for lens wearers. Using a variety of radiochemical experiments and two model lipids (cholesterol and phosphatidylcholine), a number of clinically significant parameters that may influence lipid deposition were examined. • The optimization and characterization of a novel artificial tear solution (ATS) was examined (Chapter 3) • Optimization of an extraction system to remove deposited cholesterol and phosphatidylcholine from various contact lens materials (Chapter 4) • The influence of different tear film components on lipid deposition was researched (Chapter 5) • The efficiency of hydrogen peroxide disinfecting solutions to remove deposited lipid from contact lenses was investigated (Chapter 6) • The effect of intermittent air exposure on lipid deposition was examined through the use of a custom built “model blink cell” (Chapter 7) Results: A novel complex ATS designed for in-vial incubations of contact lens materials was developed. This solution was stable and did not adversely affect the physical parameters of the contact lenses incubated within it. An efficient extraction protocol for deposited cholesterol and phosphatidylcholine was optimized based on chloroform and methanol with the addition of water and acetic acid for phosphatidylcholine extraction. Overall, cholesterol and phosphatidylcholine deposition is cumulative over time and found to deposit in greater masses on silicone-containing hydrogels. Cholesterol and phosphatidylcholine deposition is influenced by the composition of the incubation medium and air exposure which occurs during the inter-blink period. Hydrogen peroxide disinfecting solutions were able to remove only marginal amounts of lipid from the contact lenses, with the surfactant containing solution removing more. Conclusion: This thesis has provided hitherto unavailable information on the way in which lipid interacts with conventional and silicone hydrogel contact lens materials and the in vitro model built here can be utilized in various ways in the future to assess other aspects and variables of lipid and protein deposition on a variety of biomaterials.

The aim of this study is to evaluate a methodology for modeling the influence of crystallographic grain orientation on key parameters in normal and sliding contacts. The simulations of interfering cylindrical asperities, using finite element analysis, were conducted using two different plasticity models for copper: a conventional isotropic, homogeneous J2 plasticity model and a continuum crystal plasticity model. A normal contact study was conducted in which crystallographic orientation effects on different parameters were investigated. The model was then adapted for sliding contacts, which allowed other parameters such as energy dissipation to be investigated. Using crystal plasticity, the dependence of crystallographic orientation on plastic deformation and energy dissipation can be determined. The relative trends predicted using crystal plasticity are consistent with experiments that show friction depends on crystallographic orientation when plastic deformation is one of the primary energy dissipation mechanisms.

Microbial keratitis is the most serious, and only potentially blinding complication of contact lens wear. To further understand and reduce the risk of this disease, incidence rates and risk factors have been estimated in numerous studies. Since these studies were conducted, new lens types have been introduced designed to reduce the risk of infection. It was hypothesised that the issues of contact lens related hypoxia and poor lens hygiene could be addressed by the introduction of silicone hydrogel and daily disposable lenses respectively. This thesis describes the incidence of and risk factors for contact lens related microbial keratitis in Australia and New Zealand. The incidence of infection was determined by capturing all cases of contact lens related presumed microbial keratitis in a 12-month surveillance study, and by estimating the number of lens wearers using a population-based phone survey. Characteristics of the cases and controls were compared to estimate risk factors. In Australia, rates of infection with daily and overnight wear of hydrogel lenses were similar to previously published reports (1.9 [95%CI]:1.8-2.0] and 19.5 [95%CI:14.6-29.5] per 10,000 wearers respectively). Compared to the incidence of infection with hydrogel lenses, silicone hydrogel lenses had a higher rate in daily wear (11.9 [95%CI: 10.0-14.6]), and a similar rate in extended wear (19.5 [95%CI:14.6-29.5]). Daily disposable lenses had a similar rate of infection to daily wear of hydrogel lenses (2.0 [95%CI:1.7-2.4]), but appeared to reduce the incidence of severe or vision loss keratitis (0.5 [95%CI: 0.5-0.6] and 0.0 [95%CI: 0.0-0.0] respectively). Conducting the study in New Zealand confirmed the increase in incidence for overnight use of lenses, irrespective of lens type. Comparison of the incidence rates in New Zealand and Australia show that the rates in the two countries are comparable, bar an unexplained lower rate of infection for extended wear of soft hydrogel lenses in New Zealand. Risk factors for infection were overnight use of lenses, from occasional overnight to extended wear use, poor lens case hygiene, smoking, high socio-economic status and less than 6 months experience in current lens type. Amongst daily wearers, Internet or mail order purchasing of lenses was also associated with a higher risk of infection. This study is unique in terms of the study design and sample size, and the wide scope of risk factors considered. The determination of these incidence rates of infection and identification of risk factors is of extreme value to lens wearers and lens care practitioners around the world, particularly as the strongest and most prevalent risk factors are modifiable.

AIMS 1. To establish the patient demographics, risk factors, causative organisms, levels of antibiotic resistance, clinical presentations and treatment patterns of keratitis at a tertiary referral hospital in Australia. 2. To establish any change in these factors over 5 years. 3. Establish the factors associated with poor outcomes. METHODS: A retrospective audit of all patients who had a corneal culture in 5 years was conducted. Patients' clinical information was gathered from medical records and smear, culture and antibiotic resistance results were gathered from the local microbiology database. Associations between risk factors for keratitis and patient variables were analysed statistically. Outcome of a patient's episode of keratitis was classified as poor using final criteria. Trends over time in variables were analysed using linear regression. RESULTS: Two hundred and fifty-three (253) corneal cultures of 231 patients were included. Sixty percent (60%) of patients were male and there was a bimodal distribution in the age of presentation. Common risk factors for keratitis were contact lens wear (22%), ocular surface disease (18%), ocular trauma (16%) and prior ocular surgery (11 %). Corneal cultures were positive in 65% of cases and Pseudomonas aeruginosa (27%), coagulase-negative staphylococci (13%), Staphylococcus aureus (12%) and fungi (7%) were recovered. There was significant variation in the monthly recovery of P. aeruginosa (p=0.04) and fungi (p=0.02) which were more frequent in summer months, while Streptococcus pneumonia (p=0.04) was more common in winter months. Antibiotic resistance of cultured bacteria to cephalothin increased significantly (2% to 12%; p=0.02). Final vision of 6/12 or better was found in 48% (100) of cases while a poor outcome was seen in 28% (58) of cases. Multivariate analysis showed that the relative risk of a patient having a poor outcome was 4.3x (confidence interval [Cl] 2.0 to 9.5) if they had severe keratitis, 4.1 x (Cl 1.8 to 9.5) if they had keratitis related to ocular surface disease and 3.8x (Cl 1.8 to 8.3) if they were over 50 years old. CONCLUSIONS 1. In this series the most common risk factor for keratitis was contact lens wear and the most commonly isolated organism was P. aeruginosa which had seasonal variation in rate of recovery. 2. Keratitis related to contact lens wear became more frequent while keratitis related to prior ocular surgery became less frequent. 3. A poor outcome is more likely in patients with severe keratitis, keratitis related to prior ocular surface disease or older age.

Microbial keratitis is the most serious, and only potentially blinding complication of contact lens wear. To further understand and reduce the risk of this disease, incidence rates and risk factors have been estimated in numerous studies. Since these studies were conducted, new lens types have been introduced designed to reduce the risk of infection. It was hypothesised that the issues of contact lens related hypoxia and poor lens hygiene could be addressed by the introduction of silicone hydrogel and daily disposable lenses respectively. This thesis describes the incidence of and risk factors for contact lens related microbial keratitis in Australia and New Zealand. The incidence of infection was determined by capturing all cases of contact lens related presumed microbial keratitis in a 12-month surveillance study, and by estimating the number of lens wearers using a population-based phone survey. Characteristics of the cases and controls were compared to estimate risk factors. In Australia, rates of infection with daily and overnight wear of hydrogel lenses were similar to previously published reports (1.9 [95%CI]:1.8-2.0] and 19.5 [95%CI:14.6-29.5] per 10,000 wearers respectively). Compared to the incidence of infection with hydrogel lenses, silicone hydrogel lenses had a higher rate in daily wear (11.9 [95%CI: 10.0-14.6]), and a similar rate in extended wear (19.5 [95%CI:14.6-29.5]). Daily disposable lenses had a similar rate of infection to daily wear of hydrogel lenses (2.0 [95%CI:1.7-2.4]), but appeared to reduce the incidence of severe or vision loss keratitis (0.5 [95%CI: 0.5-0.6] and 0.0 [95%CI: 0.0-0.0] respectively). Conducting the study in New Zealand confirmed the increase in incidence for overnight use of lenses, irrespective of lens type. Comparison of the incidence rates in New Zealand and Australia show that the rates in the two countries are comparable, bar an unexplained lower rate of infection for extended wear of soft hydrogel lenses in New Zealand. Risk factors for infection were overnight use of lenses, from occasional overnight to extended wear use, poor lens case hygiene, smoking, high socio-economic status and less than 6 months experience in current lens type. Amongst daily wearers, Internet or mail order purchasing of lenses was also associated with a higher risk of infection. This study is unique in terms of the study design and sample size, and the wide scope of risk factors considered. The determination of these incidence rates of infection and identification of risk factors is of extreme value to lens wearers and lens care practitioners around the world, particularly as the strongest and most prevalent risk factors are modifiable.

Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, June 2008. / Thesis Advisor(s): Kwon, Young W. "June 2008." Description based on title screen as viewed on August 26, 2008. Includes bibliographical references (p. 51). Also available in print.

Thesis (M.S.)--Rochester Institute of Technology, 1990. / Includes bibliographical references.

Thesis (Ph. D.)--Rutgers University, 2009. / "Graduate Program in Computer Science." Includes bibliographical references (p. 132-139).