Models for Saturation Damage State and Interfacial Shear Strengths in Multilayer Coatings

The present work investigates the saturation damage state of a two-layer coating on a substrate (layer 1/layer 2/substrate) under uniaxial tensile loading in order to derive expressions for the interfacial strength between layer 1 and layer 2, and between layer 2 and substrate. It is based on experimental data on specimens where layer 1 is an inorganic film, layer 2 is an organic coating and the substrate is a polymer. The analysis is relevant to the cases where layer 1 cracks first, followed by layer 2, in which cracks appear due to stress concentrations caused by the cracks in layer 1. It considers the cases where at least one interface is completely yielded with shear stress equal to the interfacial shear stress, and where the crack density in layer 1 is equal to or higher than the crack density in layer 2. The possible situations depend on the relative shear strengths between layers 1 and 2 and between layer 2 and the substrate. The interfacial shear strength between layer 1 and layer 2, and between layer 2 and substrate are derived for elastic and yielded stress transfer cases and found to frame experimental values obtained with single-layer coatings

Characterisation of markers associated with systemic inflammation in children with Chronic Kidney Disease.

Chronic Kidney Disease (CKD) is a progressive condition that in the majority of cases leads to End Stage Renal Failure (ESRD) and the need for dialysis, with the only cure being renal transplant. CKD affects both adults and children; however the underlying causes of the disease are different. CKD in adults is most commonly secondary to diabetes and/or hypertension while CKD in children is usually caused by congenital structural abnormalities that result directly in renal dysfunction. There have been numerous reports of inflammatory and immunological disturbances in adult CKD that involve both the cellular and humoral immune systems. Consequences of these include an increased rate of cardiovascular disease (CVD), decreased response to vaccinations, as well as increased rates of infection, anaemia and malnutrition. Children with CKD display many of the clinical complications seen in adult kidney disease that are associated with inflammatory and immunological changes. In adults however, many of the primary conditions associated with CKD are inherently pro-inflammatory; therefore it is not clear whether the inflammatory changes observed in adults with CKD are due to pre-existing inflammatory conditions, renal disease per se or a combination of both. The majority of CKD in children is caused by conditions that are not inflammatory in nature. This presents a unique opportunity to study the inflammatory consequences of CKD alone, without the added complication of underlying inflammatory disorders. Despite this, there has been little investigation of the inflammatory and immunological status of children with CKD. Some very recent studies have shown that children with CKD have an increased systemic inflammatory state[1-3], however the nature of these immunological and inflammatory changes remains poorly defined. Identification of the specific inflammatory processes that occur in CKD may provide new treatment targets and the opportunity to develop urgently needed new therapies. The purpose of this thesis is to investigate the presence of immunological changes associated with inflammation in children with CKD. This is the first study to include children with very mild disease, and the significant changes that are present in the early stages of the disease are of particular note. I have shown that CKD in children is an intrinsically inflammatory condition, with increased accumulation of markers of oxidative stress and production of pro-inflammatory cytokines. The inflammatory markers identified in this study may be applied as a foundation for more sensitive diagnostic markers of disease progression as well as provide a basis for novel treatment strategies in this group of patients. Early identification of increased inflammation is a prerequisite for the application of preventive strategies. In addition, a better understanding of the level and mechanisms of systemic inflammation in children with CKD may enable a more accurate assessment of their risk of other inflammatory conditions such as CVD, anaemia, muscle wasting, and malnutrition. Future research that specifically focuses on the reasons and mechanisms for different rates of disease progression may emerge as a result of this study. Importantly, the findings of this study may have implications in the long term treatment of disease and may allow identification of new treatment strategies to achieve better patient outcomes. The outcomes of the study are: • Better definition of inflammatory profiles in paediatric CKD and correlation with disease severity and progression, which should contribute to improved management strategies. • Identification of new treatment targets to reduce the damage caused by chronic systemic inflammation. • Mechanistic understanding of the relationship of the inflammatory profile in regard to source leucocytes or other contributing cell types.Thesis (Ph.D.) -- University of Adelaide, School of Paediatrics and Reproductive Health, 200

An international study of consumption and contribution to social media by medical students

Understanding how students and educators use social media, and their perceptions of its benefits, may lead to opportunities for successful integration of social media to benefit all those involved in medical education. We aimed to explore and describe how medical students use social media in countries across the world, including the extent to which they consume and contribute. 741 students from 8 institutions in 5 countries answered a 16-item questionnaire. The majority of students were using some form of social media, with the most popular application being Facebook. Social communication and entertainment were the most cited reasons for using social media. Students reported valuing social media for educational reasons and, in particular, information and resource sharing between peers. Institution-student interactions were not common amongst medical students and whilst some students reported wanting more of this, others reported that they did not. The paucity of student-institution interactions on social media did not vary across institutions. Although some students could see benefits to increasing use of social media by medical schools, others had concerns about this. Of particular concern were confidentiality and professionalism online and the perception that the medical schools might not do it well. Medical schools should have a clear rationale for engaging further in social media, mindful of what students want and of the need for the engagement to be conducted professionally

Perceptions of Britishness

The aim of this paper is to contribute to scholarly debate about the nature of national identity by exploring a set of empirical data relating to the complex case of Britishness. The paper considers, with reference to the findings of field‐work conducted within a Pakistani community in London, what can be learnt about Britishness from the attitudes of young British Pakistanis. It is apparent that for such young people British national identity does not have a fixed content: their remarks draw attention to several different ‘boundaries of Britishness’ which operate in the popular imagination of people in Britain. These include the civic boundary, according to which citizenship is the primary criterion of nationality; the ‘racial’ boundary which defines as British those individuals believed to have British ancestry or ‘blood’; and the cultural boundary, according to which Britishness is a matter of the culture, values or lifestyle to which one adheres