871 resultados para Generalized impulse response functions


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Chlamydia trachomatis sexually transmitted infection can cause serious reproductive morbidities. This study determined the prevalence of serum IgG response to C. trachomatis putative stress response proteins in females to test for an association with genital tract pathology. There was no significant association of serum IgG to HtrA, Tsp, or RseP with infection or pathology. cHSP60 serum IgG prevalence was significantly associated with infection compared to negative (infertile) controls (p = 0.002), but not with upper genital tract pathology. Serum IgG1-4 antibody subclasses reactive with the antigens was not significantly different between cohorts, although different responses to each antigen were detected.

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Analytical and computational models of the intervertebral disc (IVD) are commonly employed to enhance understanding of the biomechanics of the human spine and spinal motion segments. The accuracy of these models in predicting physiological behaviour of the spine is intrinsically reliant on the accuracy of the material constitutive representations employed to represent the spinal tissues. There is a paucity of detailed mechanical data describing the material response of the reinforced­ground matrix in the anulus fibrosus of the IVD. In the present study, the ‘reinforced­ground matrix’ was defined as the matrix with the collagen fibres embedded but not actively bearing axial load, thus incorporating the contribution of the fibre-fibre and fibre-matrix interactions. To determine mechanical parameters for the anulus ground matrix, mechanical tests were carried out on specimens of ovine anulus, under unconfined uniaxial compression, simple shear and biaxial compression. Test specimens of ovine anulus fibrosus were obtained with an adjacent layer of vertebral bone/cartilage on the superior and inferior specimen surface. Specimen geometry was such that there were no continuous collagen fibres coupling the two endplates. Samples were subdivided according to disc region - anterior, lateral and posterior - to determine the regional inhomogeneity in the anulus mechanical response. Specimens were loaded at a strain rate sufficient to avoid fluid outflow from the tissue and typical stress-strain responses under the initial load application and under repeated loading were determined for each of the three loading types. The response of the anulus tissue to the initial and repeated load cycles was significantly different for all load types, except biaxial compression in the anterior anulus. Since the maximum applied strain exceeded the damage strain for the tissue, experimental results for repeated loading reflected the mechanical ability of the tissue to carry load, subsequent to the initiation of damage. To our knowledge, this is the first study to provide experimental data describing the response of the ‘reinforced­ground matrix’ to biaxial compression. Additionally, it is novel in defining a study objective to determine the regionally inhomogeneous response of the ‘reinforced­ground matrix’ under an extensive range of loading conditions suitable for mechanical characterisation of the tissue. The results presented facilitate the development of more detailed and comprehensive constitutive descriptions for the large strain nonlinear elastic or hyperelastic response of the anulus ground matrix.

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On 16 July 2003 the Australian Government’s Treasurer, the Honourable Peter Costello, addressed the Sydney Institute on his vision for a tolerant Australian society. Drawing from Putnam’s research Costello argued that tolerance will flow from an active voluntary sector. However, Costello’s proposed model for a “tolerant” society fails to acknowledge that all behaviour is strategic and that voluntary association based on disinterested action is not possible. Ultimately, Treasurer Costello’s notion of tolerant society fuelled by an active voluntary sector may not lead to his desired end. Indeed, the promotion of voluntary association may contribute to the ongoing exclusion of citizens with low social capital. Amid the dynamism of the modern era some citizens such as ageing workers, slow or ineffective learners and women may be especially at risk. Accordingly, rather than advocating a policy approach that seeks to build inclusiveness through an active voluntary sector this paper recommends a policy approach that explores ways in which to strengthen learning and the wider involvement of individuals through both formal and informal means.

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This thesis investigates Theatre for Young People (TYP) as a site of performance innovation. The inquiry is focused on contemporary dramaturgy and its fieldwork aims to identify new dramaturgical principles operating in the creation and presentation of TYP. The research then seeks to assess how these new principles contribute to Postdramatic Theatre theory. This research inquiry springs from an imperative based in practice: Young people under 25 years have a literacy based on online hypertextual experiences which take the reader outside the frames of a dramatic narrative and beyond principles such as linearity, dramatic unity, teleology and resolution. As a dramaturg and educator I wanted to understand the new ways that young people engage in cultural products, to identify and utilize the new principles of dramaturgy that are now in evidence. My research examines how two playwright/directors approach their work and the new principles that can be identified in their dramaturgy. The fieldwork is scoped into two case studies: the first on TJ Eckleberg working in Australian Theatre for Young People and the second on Kristo Šagor working in German Children’s and Young People’s Theatre (KJT). These case studies address both types of production dramaturgy - the dramaturgy emergent through process in devised performance making, and that emergent in a performance based on a written playscript. On Case Study One the researcher, as participant observer, worked as production dramaturg on a large scale, site specific performance, observing the dramaturgy in process of its director and chief devisor. On Case Study Two the researcher, as observer and analyst, undertook a performance analysis of three playscripts and productions by a contemporary German playwright and director. Utilizing participant observation, reflective practice and grounded analysis the case studies have identified two new principles animating the dramaturgy of these TYP practitioners, namely ‘displacement’ and ‘installation.’ Taking practice into theory, the thesis concludes by demonstrating how displacement and installation contribute to Postdramatic Theatre’s “arsenal of expressive gestures which serve as theatre’s response to changed social communication under the conditions of generalized communication technologies” (Lehmann, H.-T., 2006, p.23). This research makes an original contribution to knowledge by evidencing that the principles of Postdramatic Theory lie within the practice of contemporary Theatre for Young People. It also contributes valuable research to a specialized, often overlooked terrain, namely Dramaturgy in Theatre for Young People, presented here with a contemporary, international and intercultural perspective.

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The traditional model for information dissemination in disaster response is unidirectional from official channels to the public. However recent crises in the US, such as Hurricane Katrina and the Californian Bushfires show that civilians are now turning to Web 2.0 technologies as a means of sharing disaster related information. These technologies present enormous potential benefits to disaster response authorities that cannot be overlooked. In Australia, the Victorian Bushfires Royal Commission has recently recommended that Australian disaster response authorities utilize information technologies to improve the dissemination of disaster related, bushfire information. However, whilst the use of these technologies has many positive attributes, potential legal liabilities for disaster response authorities arise. This paper identifies some potential legal liabilities arising from the use of Web 2.0 technologies in disaster response situations thereby enhancing crisis related information sharing by highlighting legal concerns that need to be addressed.

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Background: Due to increases in HIV notifications in Queensland, a health promotion outreach project was developed with sex on premises venues (SOPV) in Brisbane. Methods: A health promotion officer (HPO) promoted safer sex behaviours among SOPV patrons over 14 months, including providing information, counselling and skills to enhance safer sexual behaviours and providing referrals. Surveys were introduced to facilitate discussions regarding HIV/sexually transmissible infections, testing and safer sex practices. Results: The project demonstrated feasibility within this highly sexualised environment, and was enhanced by careful monitoring and revising the procedure to improve patron/staff responses to the project. The introduction of a survey instrument was a significant contributor to the project’s effectiveness, providing opportunities for patrons to discuss a variety of key sexual health issues. Conclusions: This initiative reflected effective partnering between the Health Department, a community HIV/lesbian, gay, bisexual and transgender organisation and private industry. Despite initial difficulties, the presence of a health worker within an SOPV was acceptable to patrons and allowed for brief interventions to be conducted. This project was deemed effective for a limited time period and within certain constraints.

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Recently it has been shown that the consumption of a diet high in saturated fat is associated with impaired insulin sensitivity and increased incidence of type 2 diabetes. In contrast, diets that are high in monounsaturated fatty acids (MUFAs) or polyunsaturated fatty acids (PUFAs), especially very long chain n-3 fatty acids (FAs), are protective against disease. However, the molecular mechanisms by which saturated FAs induce the insulin resistance and hyperglycaemia associated with metabolic syndrome and type 2 diabetes are not clearly defined. It is possible that saturated FAs may act through alternative mechanisms compared to MUFA and PUFA to regulate of hepatic gene expression and metabolism. It is proposed that, like MUFA and PUFA, saturated FAs regulate the transcription of target genes. To test this hypothesis, hepatic gene expression analysis was undertaken in a human hepatoma cell line, Huh-7, after exposure to the saturated FA, palmitate. These experiments showed that palmitate is an effective regulator of gene expression for a wide variety of genes. A total of 162 genes were differentially expressed in response to palmitate. These changes not only affected the expression of genes related to nutrient transport and metabolism, they also extend to other cellular functions including, cytoskeletal architecture, cell growth, protein synthesis and oxidative stress response. In addition, this thesis has shown that palmitate exposure altered the expression patterns of several genes that have previously been identified in the literature as markers of risk of disease development, including CVD, hypertension, obesity and type 2 diabetes. The altered gene expression patterns associated with an increased risk of disease include apolipoprotein-B100 (apo-B100), apo-CIII, plasminogen activator inhibitor 1, insulin-like growth factor-I and insulin-like growth factor binding protein 3. This thesis reports the first observation that palmitate directly signals in cultured human hepatocytes to regulate expression of genes involved in energy metabolism as well as other important genes. Prolonged exposure to long-chain saturated FAs reduces glucose phosphorylation and glycogen synthesis in the liver. Decreased glucose metabolism leads to elevated rates of lipolysis, resulting in increased release of free FAs. Free FAs have a negative effect on insulin action on the liver, which in turn results in increased gluconeogenesis and systemic dyslipidaemia. It has been postulated that disruption of glucose transport and insulin secretion by prolonged excessive FA availability might be a non-genetic factor that has contributed to the staggering rise in prevalence of type 2 diabetes. As glucokinase (GK) is a key regulatory enzyme of hepatic glucose metabolism, changes in its activity may alter flux through the glycolytic and de novo lipogenic pathways and result in hyperglycaemia and ultimately insulin resistance. This thesis investigated the effects of saturated FA on the promoter activity of the glycolytic enzyme, GK, and various transcription factors that may influence the regulation of GK gene expression. These experiments have shown that the saturated FA, palmitate, is capable of decreasing GK promoter activity. In addition, quantitative real-time PCR has shown that palmitate incubation may also regulate GK gene expression through a known FA sensitive transcription factor, sterol regulatory element binding protein-1c (SREBP-1c), which upregulates GK transcription. To parallel the investigations into the mechanisms of FA molecular signalling, further studies of the effect of FAs on metabolic pathway flux were performed. Although certain FAs reduce SREBP-1c transcription in vitro, it is unclear whether this will result in decreased GK activity in vivo where positive effectors of SREBP-1c such as insulin are also present. Under these conditions, it is uncertain if the inhibitory effects of FAs would be overcome by insulin. The effects of a combination of FAs, insulin and glucose on glucose phosphorylation and metabolism in cultured primary rat hepatocytes at concentrations that mimic those in the portal circulation after a meal was examined. It was found that total GK activity was unaffected by an increased concentration of insulin, but palmitate and eicosapentaenoic acid significantly lowered total GK activity in the presence of insulin. Despite the fact that total GK enzyme activity was reduced in response to FA incubation, GK enzyme translocation from the inactive, nuclear bound, to active, cytoplasmic state was unaffected. Interestingly, none of the FAs tested inhibited glucose phosphorylation or the rate of glycolysis when insulin is present. These results suggest that in the presence of insulin the levels of the active, unbound cytoplasmic GK are sufficient to buffer a slight decrease in GK enzyme activity and decreased promoter activity caused by FA exposure. Although a high fat diet has been associated with impaired hepatic glucose metabolism, there is no evidence from this thesis that FAs themselves directly modulate flux through the glycolytic pathway in isolated primary hepatocytes when insulin is also present. Therefore, although FA affected expression of a wide range of genes, including GK, this did not affect glycolytic flux in the presence of insulin. However, it may be possible that a saturated FA-induced decrease in GK enzyme activity when combined with the onset of insulin resistance may promote the dys-regulation of glucose homeostasis and the subsequent development of hyperglycaemia, metabolic syndrome and type 2 diabetes.

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To date, studies have focused on the acquisition of alphabetic second languages (L2s) in alphabetic first language (L1) users, demonstrating significant transfer effects. The present study examined the process from a reverse perspective, comparing logographic (Mandarin-Chinese) and alphabetic (English) L1 users in the acquisition of an artificial logographic script, in order to determine whether similar language-specific advantageous transfer effects occurred. English monolinguals, English-French bilinguals and Chinese-English bilinguals learned a small set of symbols in an artificial logographic script and were subsequently tested on their ability to process this script in regard to three main perspectives: L2 reading, L2 working memory (WM), and inner processing strategies. In terms of L2 reading, a lexical decision task on the artificial symbols revealed markedly faster response times in the Chinese-English bilinguals, indicating a logographic transfer effect suggestive of a visual processing advantage. A syntactic decision task evaluated the degree to which the new language was mastered beyond the single word level. No L1-specific transfer effects were found for artificial language strings. In order to investigate visual processing of the artificial logographs further, a series of WM experiments were conducted. Artificial logographs were recalled under concurrent auditory and visuo-spatial suppression conditions to disrupt phonological and visual processing, respectively. No L1-specific transfer effects were found, indicating no visual processing advantage of the Chinese-English bilinguals. However, a bilingual processing advantage was found indicative of a superior ability to control executive functions. In terms of L1 WM, the Chinese-English bilinguals outperformed the alphabetic L1 users when processing L1 words, indicating a language experience-specific advantage. Questionnaire data on the cognitive strategies that were deployed during the acquisition and processing of the artificial logographic script revealed that the Chinese-English bilinguals rated their inner speech as lower than the alphabetic L1 users, suggesting that they were transferring their phonological processing skill set to the acquisition and use of an artificial script. Overall, evidence was found to indicate that language learners transfer specific L1 orthographic processing skills to L2 logographic processing. Additionally, evidence was also found indicating that a bilingual history enhances cognitive performance in L2.

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Objective: To examine exercise-induced changes in the reward value of food during medium-term supervised exercise in obese individuals. ---------- Subjects/Methods: The study was a 12-week supervised exercise intervention prescribed to expend 500 kcal/day, 5 d/week. 34 sedentary obese males and females were identified as responders (R) or non-responders (NR) to the intervention according to changes in body composition relative to measured energy expended during exercise. Food reward (ratings of liking and wanting, and relative preference by forced choice pairs) for an array of food images was assessed before and after an acute exercise bout. ---------- Results. 20 responders and 14 non-responders were identified. R lost 5.2 kg±2.4 of total fat mass and NR lost 1.7 kg±1.4. After acute exercise, liking for all foods increased in NR compared to no change in R. Furthermore, NR showed an increase in wanting and relative preference for high-fat sweet foods. These differences were independent of 12-weeks regular exercise and weight loss. ---------- Conclusion. Individuals who showed an immediate post-exercise increase in liking and increased wanting and preference for high-fat sweet foods displayed a smaller reduction in fat mass with exercise. For some individuals, exercise increases the reward value of food and diminishes the impact of exercise on fat loss.