Showing papers by "Queensland University of Technology published in 2007"

A survey of trust and reputation systems for online service provision

Abstract: Trust and reputation systems represent a significant trend in decision support for Internet mediated service provision. The basic idea is to let parties rate each other, for example after the completion of a transaction, and use the aggregated ratings about a given party to derive a trust or reputation score, which can assist other parties in deciding whether or not to transact with that party in the future. A natural side effect is that it also provides an incentive for good behaviour, and therefore tends to have a positive effect on market quality. Reputation systems can be called collaborative sanctioning systems to reflect their collaborative nature, and are related to collaborative filtering systems. Reputation systems are already being used in successful commercial online applications. There is also a rapidly growing literature around trust and reputation systems, but unfortunately this activity is not very coherent. The purpose of this article is to give an overview of existing and proposed systems that can be used to derive measures of trust and reputation for Internet transactions, to analyse the current trends and developments in this area, and to propose a research agenda for trust and reputation systems.

Epithelial--mesenchymal and mesenchymal--epithelial transitions in carcinoma progression.

Abstract: Like a set of bookends, cellular, molecular, and genetic changes of the beginnings of life mirror those of one of the most common cause of death--metastatic cancer. Epithelial to mesenchymal transition (EMT) is an important change in cell phenotype which allows the escape of epithelial cells from the structural constraints imposed by tissue architecture, and was first recognized by Elizabeth Hay in the early to mid 1980's to be a central process in early embryonic morphogenesis. Reversals of these changes, termed mesenchymal to epithelial transitions (METs), also occur and are important in tissue construction in normal development. Over the last decade, evidence has mounted for EMT as the means through which solid tissue epithelial cancers invade and metastasize. However, demonstrating this potentially rapid and transient process in vivo has proven difficult and data connecting the relevance of this process to tumor progression is still somewhat limited and controversial. Evidence for an important role of MET in the development of clinically overt metastases is starting to accumulate, and model systems have been developed. This review details recent advances in the knowledge of EMT as it occurs in breast development and carcinoma and prostate cancer progression, and highlights the role that MET plays in cancer metastasis. Finally, perspectives from a clinical and translational viewpoint are discussed.

Epithelial—mesenchymal and mesenchymal—epithelial transitions in carcinoma progression

Abstract: Like a set of bookends, cellular, molecular, and genetic changes of the beginnings of life mirror those of one of the most common cause of death—metastatic cancer. Epithelial to mesenchymal transition (EMT) is an important change in cell phenotype which allows the escape of epithelial cells from the structural constraints imposed by tissue architecture, and was first recognized by Elizabeth Hay in the early to mid 1980's to be a central process in early embryonic morphogenesis. Reversals of these changes, termed mesenchymal to epithelial transitions (METs), also occur and are important in tissue construction in normal development. Over the last decade, evidence has mounted for EMT as the means through which solid tissue epithelial cancers invade and metastasize. However, demonstrating this potentially rapid and transient process in vivo has proven difficult and data connecting the relevance of this process to tumor progression is still somewhat limited and controversial. Evidence for an important role of MET in the development of clinically overt metastases is starting to accumulate, and model systems have been developed. This review details recent advances in the knowledge of EMT as it occurs in breast development and carcinoma and prostate cancer progression, and highlights the role that MET plays in cancer metastasis. Finally, perspectives from a clinical and translational viewpoint are discussed

Can Directors Impact Performance? A case‐based test of three theories of corporate governance

Abstract: We examine hypothesised links between the board of directors and firm performance as predicted by the three predominant theories in corporate governance research, namely agency theory, stewardship theory and resource dependence theory. By employing a pattern matching analysis of seven cases, we are able to examine the hypothesised link between board demography and firm performance expected under each theory. We find that while each theory can explain a particular case, no single theory explains the general pattern of results. We conclude by endorsing recent calls for a more process-orientated approach to both theory and empirical analysis, if we are to understand how boards add value.

A Meta-Analysis of Six Prospective Studies of Falling in Parkinson's Disease

Abstract: Recurrent falls are a disabling feature of Parkinson's disease (PD). We have estimated the incidence of falling over a prospective 3 month follow-up from a large sample size, identified predictors for falling for PD patients repeated this analysis for patients without prior falls, and examined the risk of falling with increasing disease severity. We pooled six prospective studies of falling in PD (n = 473), and examined the predictive power of variables that were common to most studies. The 3-month fall rate was 46% (95% confidence interval: 38-54%). Interestingly, even among subjects without prior falls, this fall rate was 21% (12-35%). The best predictor of falling was two or more falls in the previous year (sensitivity 68%; specificity 81%). The risk of falling rose as UPDRS increased, to about a 60% chance of falling for UPDRS values 25 to 35, but remained at this level thereafter with a tendency to taper off towards later disease stages. These results confirm the high frequency of falling in PD, as almost 50% of patients fell during a short period of only 3 months. The strongest predictor of falling was prior falls in the preceding year, but even subjects without any prior falls had a considerable risk of sustaining future falls. Disease severity was not a good predictor of falls, possibly due to the complex U-shaped relation with falls. Early identification of the very first fall therefore remains difficult, and new prediction methods must be developed.

Surrogate Markers of Small Fiber Damage in Human Diabetic Neuropathy

Abstract: Surrogate markers of diabetic neuropathy are being actively sought to facilitate the diagnosis, measure the progression, and assess the benefits of therapeutic intervention in patients with diabetic neuropathy. We have quantified small nerve fiber pathological changes using the technique of intraepidermal nerve fiber (IENF) assessment and the novel in vivo technique of corneal confocal microscopy (CCM). Fifty-four diabetic patients stratified for neuropathy, using neurological evaluation, neurophysiology, and quantitative sensory testing, and 15 control subjects were studied. They underwent a punch skin biopsy to quantify IENFs and CCM to quantify corneal nerve fibers. IENF density (IENFD), branch density, and branch length showed a progressive reduction with increasing severity of neuropathy, which was significant in patients with mild, moderate, and severe neuropathy. CCM also showed a progressive reduction in corneal nerve fiber density (CNFD) and branch density, but the latter was significantly reduced even in diabetic patients without neuropathy. Both IENFD and CNFD correlated significantly with cold detection and heat as pain thresholds. Intraepidermal and corneal nerve fiber lengths were reduced in patients with painful compared with painless diabetic neuropathy. Both IENF and CCM assessment accurately quantify small nerve fiber damage in diabetic patients. However, CCM quantifies small fiber damage rapidly and noninvasively and detects earlier stages of nerve damage compared with IENF pathology. This may make it an ideal technique to accurately diagnose and assess progression of human diabetic neuropathy.

The Contribution of Physical Activity and Sedentary Behaviours to the Growth and Development of Children and Adolescents Implications for Overweight and Obesity

Abstract: The obesity epidemic is a global trend and is of particular concern in children. Recent reports have highlighted the severity of obesity in children by suggesting: "today's generation of children will be the first for over a century for whom life expectancy falls." This review assesses the evidence that identifies the important role of physical activity in the growth, development and physical health of young people, owing to its numerous physical and psychological health benefits. Key issues, such as "does a sedentary lifestyle automatically lead to obesity" and "are levels of physical activity in today's children less than physical activity levels in children from previous generations?", are also discussed.Today's environment enforces an inactive lifestyle that is likely to contribute to a positive energy balance and childhood obesity. Whether a child or adolescent, the evidence is conclusive that physical activity is conducive to a healthy lifestyle and prevention of disease. Habitual physical activity established during the early years may provide the greatest likelihood of impact on mortality and longevity. It is evident that environmental factors need to change if physical activity strategies are to have a significant impact on increasing habitual physical activity levels in children and adolescents. There is also a need for more evidence-based physical activity guidelines for children of all ages. Efforts should be concentrated on facilitating an active lifestyle for children in an attempt to put a stop to the increasing prevalence of obese children.

Member checking with older women: a framework for negotiating meaning.

Abstract: Encouraging participation by older people in the process of conducting research in the aged care field is paramount for developing an understanding of their experience. While some authors have recognized member checking as a way of ensuring participation in the research process, little information is available on how to conduct it. In this article a pilot study is described in which two older women discuss their experiences around receiving support services in their own home. In-depth and member checking interviews were undertaken, which were informed by Heidegger's interpretive hermeneutic phenomenology. In this study a methodology for conducting member checks is developed that is consistent with participatory approaches and the active negotiation of meaning inherent in this paradigm.

What Shapes Attitudes Toward Paying Taxes? Evidence from Multicultural European Countries*

Abstract: Objectives. Considerable evidence suggests that enforcement efforts cannot fully explain the high degree of tax compliance. To resolve this puzzle of tax compliance, several researchers have argued that citizens' attitudes toward paying taxes, defined as tax morale, helps to explain the high degree of tax compliance. However, most studies have treated tax morale as a black box, without discussing which factors shape it. Additionally, the tax compliance literature provides little empirical research that investigates attitudes toward paying taxes in Europe. Methods. Thus, this article is unique in its examination of citizen tax morale within three multicultural European countries, Switzerland, Belgium, and Spain, a choice that allows far more detailed examination of the impact of culture and institutions using data sets from the World Values Survey and the European Values Survey. Results. The results indicate the tendency that cultural and regional differences affect tax morale. Conclusion. The findings suggest that higher legitimacy for political institutions leads to higher tax morale.

Relative Income, Happiness and Utility: An Explanation for the Easterlin Paradox and Other Puzzles

Abstract: The well-known Easterlin paradox points out that average happiness has remained constant over time despite sharp rises in GNP per head. At the same time, a micro literature has typically found positive correlations between individual income and individual measures of subjective well being. This paper suggests that these two findings are consistent with the presence of relative income terms in the utility function. Income may be evaluated relative to others (social comparison) or to oneself in the past (habituation). We review the evidence on relative income from the subjective well-being literature. We also discuss the relation (or not) between happiness and utility and discuss some non-happiness research (behavioural, experimental, neurological) dealing with income comparisons. We last consider how relative income in the utility function affects economic models of behaviour in a number of different domains.

Metabolic and behavioral compensatory responses to exercise interventions: barriers to weight loss.

Abstract: An activity-induced increase in energy expenditure theoretically disturbs energy balance (EB) by creating an acute energy deficit. Compensatory responses could influence the weight loss associated with the energy deficit. Individual variability in compensation for perturbations in EB could partly explain why some individuals fail to lose weight with exercise. It is accepted that the regulatory system will readily defend impositions that promote a negative EB. Therefore, a criticism of exercise interventions is that they will be ineffective and futile methods of weight control because the acute energy deficit is counteracted. Compensation for exercise-induced energy deficits can be categorized into behavioral or metabolic responses and automatic or volitional. An automatic compensatory response is a biological inevitability and considered to be obligatory. An automatic compensatory response is typically a metabolic consequence (e.g., reduced resting metabolic rate) of a negative EB. In contrast, a volitional compensatory response tends to be deliberate and behavioral, which the individual intentionally performs (e.g., increased snack intake). The purpose of this review is to highlight the various metabolic and behavioral compensatory responses that could reduce the effectiveness of exercise and explain why some individuals experience a lower than expected weight loss. We propose that the extent and degree of compensation will vary between individuals. That is, some individuals will be predisposed to compensatory responses that render them resistant to the weight loss benefits theoretically associated with an exercise-induced increase in energy expenditure. Therefore, given the inter-individual variability in behavioral and metabolic compensatory responses, exercise prescriptions might be more effective if tailored to suit individuals.

Lymphedema After Gynecological Cancer Treatment- Prevalence, Correlates, and Supportive Care Needs

Abstract: BACKGROUND: Few studies have evaluated lymphedema following gynecological cancer. The aim of this research was to establish the prevalence, correlates and supportive care needs of gynecological cancer survivors who develop lymphedema.----- METHODS: In 2004, a population-based cross-sectional mail survey (56% response rate) was completed by 802 gynecological cancer survivors. The questionnaire included demographic questions, a validated, generic supportive care needs measure, and a supplementary, newly-developed, lymphedema needs module.----- RESULTS: Ten percent (95% CI: 8-12%) of participants reported being diagnosed with lymphedema and a further 15% (95% CI: 13-17%) reported undiagnosed ‘symptomatic’ lower limb swelling. Diagnosed lymphedema was more prevalent (36%) amongst vulvar cancer survivors. For cervical cancer survivors, those who had radiotherapy or who had lymph nodes removed had higher odds of developing swelling. For uterine and ovarian cancer survivors, those who had lymph nodes removed or who were overweight or obese had higher odds of developing swelling. Gynecological cancer survivors with lymphedema had higher supportive care needs in the information and symptom management domains compared to those with no swelling.----- CONCLUSIONS: This population-based study provides evidence that lymphedema is a morbidity experienced by a significant proportion of gynecological cancer survivors and that there are considerable levels of associated unmet need. Women at risk of lymphedema would benefit from instructions about early signs and symptoms and provision of referral information.

Disinhibition: its effects on appetite and weight regulation.

Abstract: Over the past 30 years, the understanding of eating behaviour has been dominated by the concept of dietary restraint. However, the development of the Three Factor Eating Questionnaire introduced two other factors, Disinhibition and Hunger, which have not received as much recognition in the literature. The objective of this review was to explore the relationship of the Disinhibition factor with weight regulation, food choice and eating disorders, and to consider its aetiology. The review indicates that Disinhibition is an important eating behaviour trait. It is associated not only with a higher body mass index and obesity, but also with mediating variables, such as less healthful food choices, which contribute to overweight/obesity and poorer health. Disinhibition is also implicated in eating disorders and contributes to eating disorder severity. It has been demonstrated that Disinhibition is predictive of poorer success at weight loss, and of weight regain after weight loss regimes and is associated with lower self-esteem, low physical activity and poor psychological health. Disinhibition therefore emerges as an important and dynamic trait, with influences that go beyond eating behaviour and incorporate other behaviours which contribute to weight regulation and obesity. The characteristics of Disinhibition itself therefore reflect many components representative of a thrifty type of physiology. We propose that the trait of Disinhibition be more appropriately renamed as 'opportunistic eating' or 'thrifty behaviour'.

Dynamics of Skill Acquisition: A Constraints-Led Approach

Abstract: This is an upper-level undergraduate or graduate textbook for courses in human movement and skill acquisition. A professional reference for movement practitioners and scientists, including teachers, coaches, physical educators, physical therapists, rehabilitation specialists, sport scientists, psychologists, biomechanists, and physiologists. The book provides a comprehensive analysis of the evolution of the constraints-led perspective, a recognized theory in motor learning and control. It outlines the development of a conceptual model of coordination and control within a multidisciplinary framework, capturing the various interlocking scales of analysis (e.g., neural, behavioral, psychological) and the many subsystems (e.g., perceptual and movement) involved in producing behavior. A conceptual model of coordination and control is important not just for designing learning environments, but it is also important for ensuring that learners gain positive experiences when acquiring motor skills. Practitioners and students will appreciate the applied focus which outlines a model of human movement with specific constraints-led approach strategies that address skill acquisition across a variety of professions, including teaching, coaching, and rehabilitation. By learning both the theoretical origins and applications for implementing a constraints-led approach to movement skill acquisition, readers will gain insight into how the informed organization of learning and rehabilitation environments produces more effective and efficient use of practice and therapy time. Contents: Traditional theories of skill acquisition -- Physical constraints on coordination : dynamical systems theory -- Informational constraints on coordination : an ecological perspective -- Redefining learning : a constraints-led approach -- Understanding the dynamics of skill acquisition -- Dealing with individual differences : implications for a nonlinear pedagogy -- Organizing practice to optimize learning -- Using verbal guidance as an informational constraint on learners -- Observational learning as directed search -- Implementing the constraints-led approach: case studies.

Uncertainty during Organizational Change: Managing Perceptions through Communication

Abstract: Although uncertainty has been identified as a major consequence of organizational change for employees, there still remains a lack of understanding regarding the processes through which employees address such perceptions This research examines the role that different sources of communication play in addressing change-related uncertainty for employees Firstly, a qualitative study was conducted in which 25 interviews with employees from a range of organizations were undertaken The goal of the first study was to examine how employees manage change-related uncertainties From employee responses, it was revealed that specific change-related uncertainties may be best addressed by different sources of communication Findings suggest that direct supervisors are the preferred sources of implementation-related and job-relevant information during change, while senior management typically provide more strategic information Furthermore, results indicated that trust influences which sources employees seek

Modification of the surfaces of Wyoming montmorillonite by the cationic surfactants alkyl trimethyl, dialkyl dimethyl, and trialkyl methyl ammonium bromides.

Abstract: Surfaces of a Wyoming SWy-2 sodium montmorillonite were modified using microwave radiation through intercalation with the cationic surfactants octadecyltrimethylammonium bromide, dimethyldioctadecylammonium bromide, and methyltrioctadecylammonium bromide by an ion exchange mechanism. Changes in the surfaces and structure were characterized using X-ray diffraction (XRD), thermal analysis (TG) and infrared (IR) spectroscopy. Different configurations of surfactants within montmorillonite interlayer are proposed based on d(001) basal spacings. A range of surfactant molecular environments within the surface-modified montmorillonite are proposed based upon their thermal decomposition. IR spectroscopy using a smart endurance single bounce diamond attenuated total reflection (ATR) cell has been used to study the changes in the spectra of CH asymmetric and symmetric stretching modes of the surfactants to provide more information of the surfactant molecular configurations.

Produsage : Towards a Broader Framework for User-Led Content Creation

Abstract: This paper outlines the concept of produsage as a model of describing today’s emerging user-led content creation environments. Produsage overcomes some of the systemic problems associated with translating industrial-age ideas of content production into an informational-age, social software, Web 2.0 environment. Instead, it offers new ways of understanding the collaborative content creation and development practices found in contemporary informational environments.

Coping and resilience in refugees from the Sudan: a narrative account.

Abstract: Objective: The purpose of this paper was to identify and explicate coping and resilience themes employed by 13 resettled Sudanese refugees.Method: A sample of 13 Sudanese refugees was asked to describe their experience of coping in the three periods of their migration, namely: pre migration from Sudan, transit, and post migration in their host country. Members of the sample participated in qualitative interviews conducted with the assistance a bilingual community worker.Results: Three themes that characterized the experience of resettled refugees across all periods were: religious beliefs, social support and personal qualities. A fourth less salient, theme, comparison with others, also emerged in the post-migration context.Conclusions: A number of themes associated with coping and resilience in response to trauma were identified. These themes may be translated into strategies to assist in responding constructively to trauma. Such approaches may be used to improve the well-being of resettled refugees in Au...

Rethinking scaffolding in the information age

Abstract: This paper addresses the use of scaffolding in learning contexts that incorporate technologically based novel problems. We suggest that in computer contexts extended conceptualisations of scaffolding are needed in order to gain greater insights into teaching and learning processes. Our work has revealed that traditional forms of scaffolding, based on the ''expert's'' view of how the problem should be solved, need to be modified in order to accommodate the child's perspective and that three different types of scaffolding which we refer to as cognitive, technical and affective can be conceptualized. This paper discusses the ways in which the performance of pairs of children is enhanced in such scaffolding contexts, to include more examples of metastrategic processes and strategies for problem-solving, than when the pairs are left to spontaneously solve the problems. This study provides additional support that cognitive, affective and technical scaffolding are beneficial for learning and that children are able to support each others learning via sharing strategies and articulating the reasons behind them to each other.

The Roles of Hypoxia in the In Vitro Engineering of Tissues

Abstract: Oxygen is a potent modulator of cell function and wound repair in vivo. The lack of oxygen (hypoxia) can create a potentially lethal environment and limit cellular respiration and growth or, alternatively, enhance the production of the specific extracellular matrix components and increase angiogenesis through the hypoxia-inducible factor-1 pathway. For the in vitro generation of clinically relevant tissue-engineered grafts, these divergent actions of hypoxia should be addressed. Diffusion through culture medium and tissue typically limits oxygen transport in vitro, leading to hypoxic regions and limiting the viable tissue thickness. Approaches to overcoming the transport limitations include culture with bioreactors, scaffolds with artificial microvasculature, oxygen carriers, and hyperbaric oxygen chambers. As an alternate approach, angiogenesis after implantation may be enhanced by incorporating endothelial cells, genetically modified cells, or specific factors (including vascular endothelial growth factor) into the scaffold or exposing the graft to a hypoxic environment just before implantation. Better understanding of the roles of hypoxia will help prevent common problems and exploit potential benefits of hypoxia in engineered tissues.

The roles of hypoxia in the in vitro engineering of tissues

Abstract: Oxygen is a potent modulator of cell function and wound repair in vivo. The lack of oxygen (hypoxia) can create a potentially lethal environment and limit cellular respiration and growth or, alternatively, enhance the production of the specific extracellular matrix components and increase angiogenesis through the hypoxia-inducible factor-1 pathway. For the in vitro generation of clinically relevant tissue-engineered grafts, these divergent actions of hypoxia should be addressed. Diffusion through culture medium and tissue typically limits oxygen transport in vitro, leading to hypoxic regions and limiting the viable tissue thickness. Approaches to overcoming the transport limitations include culture with bioreactors, scaffolds with artificial microvasculature, oxygen carriers, and hyperbaric oxygen chambers. As an alternate approach, angiogenesis after implantation may be enhanced by incorporating endothelial cells, genetically modified cells, or specific factors (including vascular endothelial growth factor) into the scaffold or exposing the graft to a hypoxic environment just before implantation. Better understanding of the roles of hypoxia will help prevent common problems and exploit potential benefits of hypoxia in engineered tissues.