A comparison of subjective and objective measures of physical activity and fitness in identifying associations with cardiometabolic risk factors

Purpose
To compare the ability of alternative measures of physical activity and fitness to quantify associations with health outcomes.

Methods
Associations between a range of subjective and objective physical activity and fitness measures and cardiometabolic risk factors were examined using data from 1,631 Australians aged 26–36 years. Anthropometry, fitness, blood pressure, and fasting blood glucose, insulin, and lipids were measured at study clinics. Participants completed the International Physical Activity Questionnaire (IPAQ) and 7-day pedometer diaries; they also reported sedentary behavior (sitting, television viewing).

Results
In men and women, associations were strongest for fitness, with those in the highest (vs. lowest) fitness quarter having a 75% to 80% lower prevalence of two or more primary risk factors (waist circumference, high-density lipoprotein cholesterol, and insulin resistance). In men, a 60% to 70% reduced prevalence of two or more risk factors was observed across extreme quarters of IPAQ leisure, IPAQ vigorous, sitting duration, and pedometer measures. Similar reductions in prevalence were observed only across extreme quarters of pedometer activity and television viewing in women.

Conclusions
Associations between alternative measures and cardiometabolic risk were relatively independent, suggesting that a range of physical activity and fitness measures may be needed to most accurately quantify associations between physical activity and health.

Numerical investigation of high and low pressure tube hydroforming

Hydroforming is one option to reduce vehicle weight while increasing component stiffness and rigidity. This typically involves using a fluid to form a component with high internal pressure. Tube hydroforming has gained increasing interest in the automotive and aerospace industries because of its many advantages such as part consolidation, good quality of the formed part etc. The main advantage is that the uniform pressure can be transferred to whole part at the same time. In low pressure hydroforming, the internal pressure is significantly and the hydroformed section length of line stays almost the same as the circumference of the blank tube. This paper details the comparison between high and low pressure hydroforming. It is shown that the internal pressure and holding force required for low pressure hydroforming process is much less than that of high pressure. Also stress and thickness distribution are more uniform and the process is highly suitable for the forming of advanced high strength steels.

Testimony and memory : re-writeable video memoirs

In Chris Marker’s Sunless (1985), the narrator states: “We do not remember, we re-write memory much as history is rewritten.” This presentation considers the ways in which my parents’ stories have been (and can be) re-written. In 1996, my father and mother engaged in a process of remembering, narrating and re-considering their histories when their video testimonies were recorded for the Survivors of the Shoah Visual History Foundation. They experienced much of World War II in different locations – only re-united after many months. For these video testimonies, they were recorded separately – once again, with a distance of many months between. Whenever there is an attempt to protect a story from interruption and contradiction, narrative multiplicity arises. By comparing and analysing their separate stories in terms of what was said, what was not said, what was unspeakable, and what was unknowable, I am interested in the uncertainties, the gaps, and the different ways in which they attempted to re-make their own histories whilst in the midst of storytelling. I am also interested in re-editing these memoirs into a multi-perspectival family video album, in which the stories and storytellers re-inhabit a shared and re-writeable space of storytelling.

What is a presentational media regime? The contemporary breakdown in systems of representation

Foundational to both the operation and legitimation of our traditional media is the idea of representation: in some sense the images of television, the sounds of radio, the narratives of film, and the various public personalities stand in or in place of ourselves. Likewise our contemporary political system function as an elaborate representational system, where regions, "seats", electorates, the nation, and the nationstate are represented by individuals, parties and symbols. Although, there are differences between and among modern nation-states as clearly different political and cultural agendas are at play, the interplay of contemporary media, culture and politics has produced what can be called a 'representational regime' that more or less operates globally, albeit fragmented into national and regional groupings.

This paper explores the initial stages in the breakdown of this system of representation that has allowed a certain organization of culture and politics to expand and develop over the last two centuries. It acknowledges that central to this regime is something Nick Couldry has identified as "the myth of the mediated centre" (Couldry, 2003). What the paper argues, and therefore differs from Couldry's conclusion, is that there are cracks in the glue that holds the system together and they are emerging in the uses of new media. Through an exploration of presentational media - that is, media that is more involved with the presentation of the self for public/private and networked consumption than traditional media's effort to embody their audience in its narratives - the paper reaches for conclusions that identify a more elaborate legitimation crisis looming in our political and cultural worlds.

Communicating climate change: public responsiveness and matters of concern

Since climate change captured global attention in the 1990s, the private individual, addressed as a member of a concerned public, has occupied a focal position in the discourse of environmental amelioration. Recently, a range of prominent books, films and television programs — for example, Tim Flannery’s The Weather Makers (2005), Al Gore’s An Inconvenient Truth (2006) and ABC TV’s Carbon Cops (2007) — have promoted the role of the individual as the ‘starting point’ for effective environmental action. These texts assume that the provision and comprehension of sufficient information to the public about climate change will change individual habits and practices. This accords with the ‘information-deficit model’ in environmental communication research, a concept that asserts a direct connection between individual awareness and response, and collective action. This paper discusses the limitations of this model, pervasive in both popular and official approaches to climate change. It will interrogate the philosophical assumptions that underlie it, in which nature and culture are polarised and the human is positioned in a certain, and separate, relationship to the non-human world — an inheritance of the very logic that enables the continued exploitation of nature. Applying Bruno Latour’s notion of a ‘matter of concern’ to climate change, where the gathering of a range of irreducible forces and im/materialities continually produce these phenomena, this paper proposes that, in thinking about climate change as essentially unrepresentable, a different mode of public engagement with the issue is asserted.

Socioeconomic position and children's physical activity and sedentary behaviors : longitudinal findings from the CLAN study

Background: This study aimed to examine cross-sectional and longitudinal associations between socioeconomic position (SEP) and physical activity and sedentary behaviors amongst children and adolescents.

Methods: Maternal education was reported by parents of 184 5-6 year-old and 358 10-12 year-old children in 2001. In 2001 and 2004, physical activity was assessed by accelerometry. Older children self-reported and parents of younger children proxy-reported physical activity and television (TV) viewing behaviors. Linear regression was used to predict physical activity and sedentary behaviors, and changes in these behaviors, from maternal education.

Results: Among all children, accelerometer-determined and self/parent-reported moderate and vigorous physical activity declined over three years. Girls of higher SEP demonstrated greater decreases in TV viewing behaviours than those of low SEP. In general, no prospective associations were evident between SEP and objectively-assessed physical activity. A small number of prospective associations were noted between SEP and self-reported physical activity, but these were generally weak and inconsistent in direction.

Conclusions: This study did not find strong evidence that maternal education was cross-sectionally or longitudinally predictive of children’s physical activity or sedentary behaviors. Given the well-documented inverse relationship of SEP with physical activity levels in adult samples, findings suggest that such disparities may emerge after adolescence.

Tribology of lubricated nitrocarburised and titanium carbonitride surfaces

In the current work, two different coatings, nitrocarburised (CN) and titanium carbonitride (TiCN) on M2 grade high speed tool steel, were prepared by commercial diffusion and physical vapour deposition (PVD) techniques, respectively. Properties of the coating were characterised using a variety of techniques such as Glow-Discharge Optical Emission Spectrometry (GD-OES) and Scanning Electron Microscopy (SEM). Three non-commercial, oil-based lubricants with simplified formulations were used for this study. A tribological test was developed in which two nominally geometrically-identical crossed cylinders slide over each other under selected test conditions. This test was used to evaluate the effectiveness of a pre-applied lubricant film and a surface coating for various conditions of sliding wear. Engineered surface coatings can significantly improve wear resistance of the tool surface but their sliding wear performances strongly depend on the type of coating and lubricant combination used. These coating-lubricant interactions can also have a very strong effect on the useful life of the lubricant in a tribological system. Better performance of lubricants during the sliding wear testing was achieved hen used with the nitrocarburised (CN) coating. To understand the nature of the interactions and their possible effects on the coating-lubricant system, several surface analysis techniques were used. The molecular level investigation of Fourier Transform Infrared Spectroscopy (FTIR) revealed that oxidative degradation occurred in all used oil-based lubricants during the sliding wear test but the degradation behaviour of oil-based lubricants varied with the coating-lubricant system and the wear conditions. The main differences in the carbonyl oxidation region of the FTIR spectra (1900-1600 cm-1) between different coating-lubricant systems may relate to the effective lifetime of the lubricant during the sliding wear test. Secondary Ion Mass Spectrometry (SIMS) depth profiling shows that the CN coating has the highest lubricant absorbability among the tested tool surfaces. Diffusion of chlorine (C1), hydrogen (H) and oxygen (O) into the surface of subsurface of the tool suggested that strong interactions occurred between lubricant and tool surface during the sliding wear test. The possible effects of the interactions on the performance of whole tribological system are also discussed. The study of Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) indicated that the envelope of hydrocarbons (CmHn) of oil lubricant in the positive TOF-SIMS spectra shifted to lower mass fragment after the sliding wear testing due to the breakage of long-chain hydrocarbons to short-chain ones during the degradation of lubricant. The shift of the mass fragment range of the hydrocarbon (CmHn) envelope caries with the type of both tool surface and lubricant, again confirming that variation in the performance of the tool-lubricant system relates to the changes in surface chemistry due to tribochemical interactions at the tool-lubricant interface under sliding wear conditions. The sliding wear conditions resulted in changes not only in topography of the tool surface due to mechanical interactions, as outlined in Chapter 5, but also in surface chemistry due to tribochemical interactions, as discussed in Chapters 6 and 7.

Envisioning Indochina : the spatial and social ordering and imagining of a French colony

The emergence of Indochina in the French imagination was articulated in both representational and institutional modes. Representation involves the transmission of colonial ideals through more obtuse means; that is, through literary texts, travelogues, exhibitions, film and advertising. However, these textual sites feed from and invest in a material situation, which was the institutional arm of colonialism. Indochina was institutionally articulated in cartographic maps and surveys, in the new social spaces of cities and towns, in architectural and technological forms, through social technologies of discipline and welfare and in cultural and religious organisations. The aim of this thesis is to analyse, across a number of textual sites, the representation and institutionalisation of Otherness through the politics of space in the French colony of Indochina, Indochine in this sense becomes a spatial discourse. The French constructed a mental and physical space for Indochina by blanketing and suffocating the original cultural landscape, which in fact had to be ignored for this process to occur. What actually became manifest as a result of this projection stemmed from the French imagination. Just as the French manipulated space, language also underwent the same process of reduction. The Vietnamese script was latinised to make it more 'useable' and ‘accessible’. Through christening the union of Indochina; initiating a comprehensive writing reform; and renaming the streets in the colonial cities, the French used language us another tool for 'making transparent'. Furthermore, the colonial powers established a communication and transport network throughout the colony in an attempt to materialise their fictive (artificial) vision of a unified French Indochinese space. The accessibility and design of these different modes of transport reflected the gendered, racial and class divisions inherent in the colonial establishment. At the heart of representing and institutionalising Indochina was the desire to control and contain. This characterised French imperial ordering of space in the city and the rural areas. In rural areas land was divided into small parcels and alienated to individuals or worked into precise grids for the rubber plantation. In urban centres the native quarter was clearly demarcated from the European quarter which functioned as its modern, progressive Other. The rationale behind this segregation was premised on European, nineteenth century discourses of race, class, gender and hygiene. Influenced by Darwinian and neo-Lamarkian theories of race, this biological discourse identified the 'working class', 'women' and 'the native' as not only biologically but also culturally inferior. They were perceived as a potential, degenerative threat to the biological, cultural and industrial development of the nation. In the colonial context, space was thus ordered and domesticated to control the native population. Coextensively, the literature which springs from such a structure will be tainted by the same ideas, and thus the spaces it formulates within the readers mind feed on and reinforce this foundation. Examples of gender and indigenous narratives which contest this imaginative, transparent topography are analysed throughout this thesis. They provide instances of struggle and resistance which undermine the ideal/stereotypical level of architectural and planned space and delineate an alternative insight into colonial spatial and social relations. The fictional accounts of European women and indigenous writers both challenge and reaffirm the fixity of some of these idealised colonial boundaries. In various literary, historical, political, architectural and cinematic discourses Indochina has been und continues to be depicted as a modern city and exotic Utopia. Informed by the mood of nostalgia, exotic images of Indochina have resurfaced in contemporary French culture. France's continued desire to create, control and maintain an Indochinese space in the French public imagination reinforces the multi-layered, interconnected and persistent nature of colonial discourse.

Tariff protection and politics : Castlemaine 1870-1901

This study, set within the contextual background of Victorian politics, ‘seeks to identify the economic, political and social implications of tariff protection for the Castlemaine region from 1870-1901. The introduction of the Victorian tariff in 1865 precipitated a reversal of earlier attitudes towards protection by politicians and their constituents. Reasons are sought for changes in the perceptions of the Castlemaine electorate and its political representatives towards the tariff between 1870 and Federation. An examination has been made of the role of the tariff in the creation of employment in the region’s primary and secondary industries together with its influence on politicians, primary and secondary industry leaders and workers. Also explored is the relative impact of the tariff on the economic performance of Castlemaine industries, whether producing for export or domestic markets.