16 resultados para Alberoni, Giulio, 1664-1752.

em Queensland University of Technology - ePrints Archive


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In an investigation of the problems and coping strategies of Australian high school students, comparisons were made between the responses of 1664 students enrolled in years 8 to 12 in 1988, 1620 students enrolled in the same year levels in 1993, and 178 high school teachers in 1993. The subjects completed the High School Stressors Scale and the Adolescent Coping Strategies Scale. Data analyses using MANOVAs, ANOVAs, and t- tests revealed close similarities between the responses of the 1993 students and those of the 1988 students, but a considerable amount of incongruence between the responses of the students and those of the teachers. In particular, the teachers generally seemed to regard their students' problems as being more serious than was acknowledged by the students, and the teachers generally seemed to project a less positive view of adolescents' coping strategies than did the students. These discrepancies are discussed in terms of the different orientations that students and teachers bring to the student- teacher relationship. It is suggested that teachers and counsellors need to take cognisance of the differences between adolescents' perspectives and their own if they are going to be effective in assisting students to develop positive coping strategies and in creating more positive learning environments.

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Objective: To define characteristics of all-terrain vehicle (ATV) crashes occurring in north Queensland from March 2004 till June 2007 with the exploration of associated risk factors. Design: Descriptive analysis of ATV crash data collected by the Rural and Remote Road Safety Study. Setting: Rural and remote north Queensland. Participants: Forty-two ATV drivers and passengers aged 16 years or over hospitalised at Atherton, Cairns, Mount Isa or Townsville for at least 24 hours as a result of a vehicle crash. Main outcome measures: Demographics of participants, reason for travel, nature of crash, injuries sustained and risk factors associated with ATV crash. Results: The majority of casualties were men aged 16–64. Forty-one per cent of accidents occurred while performing agricultural tasks. Furthermore, 39% of casualties had less than one year’s experience riding ATVs. Over half the casualties were not wearing a helmet at the time of the crash. Common injuries were head and neck and upper limb injuries. Rollovers tended to occur while performing agricultural tasks and most commonly resulted in multiple injuries. Conclusions: Considerable trauma results from ATV crashes in rural and remote north Queensland. These crashes are not included in most general vehicle crash data sets, as they are usually limited to events occurring on public roads. Minimal legislation and regulation currently applies to ATV use in agricultural, recreational and commercial settings. Legislation on safer design of ATVs and mandatory courses for riders is an essential part of addressing the burden of ATV crashes on rural and remote communities.

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Background In order to provide insights into the complex biochemical processes inside a cell, modelling approaches must find a balance between achieving an adequate representation of the physical phenomena and keeping the associated computational cost within reasonable limits. This issue is particularly stressed when spatial inhomogeneities have a significant effect on system's behaviour. In such cases, a spatially-resolved stochastic method can better portray the biological reality, but the corresponding computer simulations can in turn be prohibitively expensive. Results We present a method that incorporates spatial information by means of tailored, probability distributed time-delays. These distributions can be directly obtained by single in silico or a suitable set of in vitro experiments and are subsequently fed into a delay stochastic simulation algorithm (DSSA), achieving a good compromise between computational costs and a much more accurate representation of spatial processes such as molecular diffusion and translocation between cell compartments. Additionally, we present a novel alternative approach based on delay differential equations (DDE) that can be used in scenarios of high molecular concentrations and low noise propagation. Conclusions Our proposed methodologies accurately capture and incorporate certain spatial processes into temporal stochastic and deterministic simulations, increasing their accuracy at low computational costs. This is of particular importance given that time spans of cellular processes are generally larger (possibly by several orders of magnitude) than those achievable by current spatially-resolved stochastic simulators. Hence, our methodology allows users to explore cellular scenarios under the effects of diffusion and stochasticity in time spans that were, until now, simply unfeasible. Our methodologies are supported by theoretical considerations on the different modelling regimes, i.e. spatial vs. delay-temporal, as indicated by the corresponding Master Equations and presented elsewhere.

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Issues of equity and inequity have always been part of employment relations and are a fundamental part of the industrial landscape. For example, in most countries in the nineteenth century and a large part of the twentieth century women and members of ethnic groups (often a minority in the workforce) were barred from certain occupations, industries or work locations, and received less pay than the dominant male ethnic group for the same work. In recent decades attention has been focused on issues of equity between groups, predominantly women and different ethnic groups in the workforce. This has been embodied in industrial legislation, for example in equal pay for women and men, and frequently in specific equity legislation. In this way a whole new area of law and associated workplace practice has developed in many countries. Historically, employment relations and industrial relations research has not examined employment issues disaggregated by gender or ethnic group. Born out of concern with conflict and regulation at the workplace, studies tended to concentrate on white, male, unionized workers in manufacturing and heavy industry (Ackers, 2002, p. 4). The influential systems model crafted by Dunlop (1958) gave rise to The discipline’s preoccupation with the ‘problem of order’ [which] ensures the invisibility of women, not only because women have generally been less successful in mobilizing around their own needs and discontents, but more profoundly because this approach identifies the employment relationship as the ultimate source of power and conflict at work (Forrest, 1993, p. 410). While ‘the system approach does not deliberately exclude gender . . . by reproducing a very narrow research approach and understanding of issues of relevance for the research, gender is in general excluded or looked on as something of peripheral interest’ (Hansen, 2002, p. 198). However, long-lived patterns of gender segregation in occupations and industries, together with discriminatory access to work and social views about women and ethnic groups in the paid workforce, mean that the employment experience of women and ethnic groups is frequently quite different to that of men in the dominant ethnic group. Since the 1980s, research into women and employment has figured in the employment relations literature, but it is often relegated to a separate category in specific articles or book chapters, with women implicitly or explicitly seen as the atypical or exceptional worker (Hansen, 2002; Wajcman, 2000). The same conclusion can be reached for other groups with different labour force patterns and employment outcomes. This chapter proposes that awareness of equity issues is central to employment relations. Like industrial relations legislation and approaches, each country will have a unique set of equity policies and legislation, reflecting their history and culture. Yet while most books on employment and industrial relations deal with issues of equity in a separate chapter (most commonly on equity for women or more recently on ‘diversity’), the reality in the workplace is that all types of legislation and policies which impact on the wages and working conditions interact, and their impact cannot be disentangled one from another. When discussing equity in workplaces in the twenty-first century we are now faced with a plethora of different terms in English. Terms used include discrimination, equity, equal opportunity, affirmative action and diversity with all its variants (workplace diversity, managing diversity, and so on). There is a lack of agreed definitions, particularly when the terms are used outside of a legislative context. This ‘shifting linguistic terrain’ (Kennedy-Dubourdieu, 2006b, p. 3) varies from country to country and changes over time even within the one country. There is frequently a division made between equity and its related concepts and the range of expressions using the term ‘diversity’ (Wilson and Iles, 1999; Thomas and Ely, 1996). These present dilemmas for practitioners and researchers due to the amount and range of ideas prevalent – and the breadth of issues that are covered when we say ‘equity and diversity in employment’. To add to these dilemmas, the literature on equity and diversity has become bifurcated: the literature on workplace diversity/management diversity appears largely in the business literature while that on equity in employment appears frequently in legal and industrial relations journals. Workplaces of the twenty-first century differ from those of the nineteenth and twentieth century not only in the way they deal with individual and group differences but also in the way they interpret what are fair and equitable outcomes for different individuals and groups. These variations are the result of a range of social conditions, legislation and workplace constraints that have influenced the development of employment equity and the management of diversity. Attempts to achieve employment equity have primarily been dealt with through legislative means, and in the last fifty years this legislation has included elements of anti-discrimination, affirmative action, and equal employment opportunity in virtually all OECD countries (Mor Barak, 2005, pp. 17–52). Established on human rights and social justice principles, this legislation is based on the premise that systemic discrimination has and/or continues to exist in the labour force and particular groups of citizens have less advantageous employment outcomes. It is based on group identity, and employment equity programmes in general apply across all workplaces and are mandatory. The more recent notions of diversity in the workplace are based on ideas coming principally from the USA in the 1980s which have spread widely in the Western world since the 1990s. Broadly speaking, diversity ideas focus on individual differences either on their own or in concert with the idea of group differences. The diversity literature is based on a business case: that is diversity is profitable in a variety of ways for business, and generally lacks a social justice or human rights justification (Burgess et al., 2009, pp. 81–2). Managing diversity is represented at the organizational level as a voluntary and local programme. This chapter discusses some major models and theories for equity and diversity. It begins by charting the history of ideas about equity in employment and then briefly discusses what is meant by equality and equity. The chapter then analyses the major debates about the ways in which equity can be achieved. The more recent ideas about diversity are then discussed, including the history of these ideas and the principles which guide this concept. The following section discusses both major frameworks of equity and diversity. The chapter then raises some ways in which insights from the equity and diversity literature can inform employment relations. Finally, the future of equity and diversity ideas is discussed.

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Although mobile phones are often used in public urban places to interact with one’s geographically dispersed social circle, they can also facilitate interactions with people in the same public urban space. The PlaceTagz study investigates how physical artefacts in public urban places can be utilised and combined with mobile phone technologies to facilitate interactions. Printed on stickers, PlaceTagz are QR codes linking to a digital message board enabling collocated users to interact with each other over time resulting in a place-based digital memory. This exploratory project set out to investigate if and how PlaceTagz are used by urban dwellers in a real world deployment. We present findings from analysing content received through PlaceTagz and interview data from application users. QR codes, which do not contain any contextual information, piqued the curiosity of users wondering about the embedded link’s destination and provoked comments in regards to people, place and technology.

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“The Cube” is a unique facility that combines 48 large multi-touch screens and very large-scale projection surfaces to form one of the world’s largest interactive learning and engagement spaces. The Cube facility is part of the Queensland University of Technology’s (QUT) newly established Science and Engineering Centre, designed to showcase QUT’s teaching and research capabilities in the STEM (Science, Technology, Engineering, and Mathematics) disciplines. In this application paper we describe, the Cube, its technical capabilities, design rationale and practical day-to-day operations, supporting up to 70,000 visitors per week. Essential to the Cube’s operation are five interactive applications designed and developed in tandem with the Cube’s technical infrastructure. Each of the Cube’s launch applications was designed and delivered by an independent team, while the overall vision of the Cube was shepherded by a small executive team. The diversity of design, implementation and integration approaches pursued by these five teams provides some insight into the challenges, and opportunities, presented when working with large distributed interaction technologies. We describe each of these applications in order to discuss the different challenges and user needs they address, which types of interactions they support and how they utilise the capabilities of the Cube facility.

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Background The expansion of cell colonies is driven by a delicate balance of several mechanisms including cell motility, cell-to-cell adhesion and cell proliferation. New approaches that can be used to independently identify and quantify the role of each mechanism will help us understand how each mechanism contributes to the expansion process. Standard mathematical modelling approaches to describe such cell colony expansion typically neglect cell-to-cell adhesion, despite the fact that cell-to-cell adhesion is thought to play an important role. Results We use a combined experimental and mathematical modelling approach to determine the cell diffusivity, D, cell-to-cell adhesion strength, q, and cell proliferation rate, ?, in an expanding colony of MM127 melanoma cells. Using a circular barrier assay, we extract several types of experimental data and use a mathematical model to independently estimate D, q and ?. In our first set of experiments, we suppress cell proliferation and analyse three different types of data to estimate D and q. We find that standard types of data, such as the area enclosed by the leading edge of the expanding colony and more detailed cell density profiles throughout the expanding colony, does not provide sufficient information to uniquely identify D and q. We find that additional data relating to the degree of cell-to-cell clustering is required to provide independent estimates of q, and in turn D. In our second set of experiments, where proliferation is not suppressed, we use data describing temporal changes in cell density to determine the cell proliferation rate. In summary, we find that our experiments are best described using the range D = 161 - 243 ?m2 hour-1, q = 0.3 - 0.5 (low to moderate strength) and ? = 0.0305 - 0.0398 hour-1, and with these parameters we can accurately predict the temporal variations in the spatial extent and cell density profile throughout the expanding melanoma cell colony. Conclusions Our systematic approach to identify the cell diffusivity, cell-to-cell adhesion strength and cell proliferation rate highlights the importance of integrating multiple types of data to accurately quantify the factors influencing the spatial expansion of melanoma cell colonies.

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Background Sexually-transmitted pathogens often have severe reproductive health implications if treatment is delayed or absent, especially in females. The complex processes of disease progression, namely replication and ascension of the infection through the genital tract, span both extracellular and intracellular physiological scales, and in females can vary over the distinct phases of the menstrual cycle. The complexity of these processes, coupled with the common impossibility of obtaining comprehensive and sequential clinical data from individual human patients, makes mathematical and computational modelling valuable tools in developing our understanding of the infection, with a view to identifying new interventions. While many within-host models of sexually-transmitted infections (STIs) are available in existing literature, these models are difficult to deploy in clinical/experimental settings since simulations often require complex computational approaches. Results We present STI-GMaS (Sexually-Transmitted Infections – Graphical Modelling and Simulation), an environment for simulation of STI models, with a view to stimulating the uptake of these models within the laboratory or clinic. The software currently focuses upon the representative case-study of Chlamydia trachomatis, the most common sexually-transmitted bacterial pathogen of humans. Here, we demonstrate the use of a hybrid PDE–cellular automata model for simulation of a hypothetical Chlamydia vaccination, demonstrating the effect of a vaccine-induced antibody in preventing the infection from ascending to above the cervix. This example illustrates the ease with which existing models can be adapted to describe new studies, and its careful parameterisation within STI-GMaS facilitates future tuning to experimental data as they arise. Conclusions STI-GMaS represents the first software designed explicitly for in-silico simulation of STI models by non-theoreticians, thus presenting a novel route to bridging the gap between computational and clinical/experimental disciplines. With the propensity for model reuse and extension, there is much scope within STI-GMaS to allow clinical and experimental studies to inform model inputs and drive future model development. Many of the modelling paradigms and software design principles deployed to date transfer readily to other STIs, both bacterial and viral; forthcoming releases of STI-GMaS will extend the software to incorporate a more diverse range of infections.

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Aspergillus terreus is successfully used for industrial production of itaconic acid. The acid is formed from cis-aconitate, an intermediate of the tricarboxylic (TCA) cycle, by catalytic action of cis-aconitate decarboxylase. It could be assumed that strong anaplerotic reactions that replenish the pool of the TCA cycle intermediates would enhance the synthesis and excretion rate of itaconic acid. In the phylogenetic close relative Aspergillus niger, upregulated metabolic flux through glycolysis has been described that acted as a strong anaplerotic reaction. Deregulated glycolytic flux was caused by posttranslational modification of 6-phosphofructo-1-kinase (PFK1) that resulted in formation of a highly active, citrate inhibition-resistant shorter form of the enzyme. In order to avoid complex posttranslational modification, the native A. niger pfkA gene has been modified to encode for an active shorter PFK1 fragment. By the insertion of the modified A. niger pfkA genes into the A. terreus strain, increased specific productivities of itaconic acid and final yields were documented by transformants in respect to the parental strain. On the other hand, growth rate of all transformants remained suppressed which is due to the low initial pH value of the medium, one of the prerequisites for the accumulation of itaconic acid by A. terreus mycelium. © 2010 Springer-Verlag.

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Through larger-scale molecular dynamics simulations, we investigated the impacts from vacancy-initiated linkages on the thermal conductivity of bilayer graphene sheets (of size L × W = 24.5 nm × 3.7 nm). Three different interlayer linkages, including divacancy bridging, “spiro” interstitial bridging and Frenkel pair defects, are considered. It is found that the presence of interlayer linkages induces a significant degradation in the thermal conductivity of the bilayer graphene sheet. The degradation is strongly dependent on the interlayer linkage type, concentration and location. More importantly, the linkages that contain vacancies lead to more severe suppression of the thermal conductivity, in agreement with theoretical predictions that vacancies induce strong phonon scattering. Our finding provides useful guidelines for the application of multilayer graphene sheets in practical thermal management.

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Driver cognitions about aggressive driving of others are potentially important to the development of evidence-based interventions. Previous research has suggested that perceptions that other drivers are intentionally aggressive may influence recipient driver anger and subsequent aggressive responses. Accordingly, recent research on aggressive driving has attempted to distinguish between intentional and unintentional motives in relation to problem driving behaviours. This study assessed driver cognitive responses to common potentially provocative hypothetical driving scenarios to explore the role of attributions in driver aggression. A convenience sample of 315 general drivers 16–64 yrs (M = 34) completed a survey measuring trait aggression (Aggression Questionnaire AQ), driving anger (Driving Anger Scale, DAS), and a proxy measure of aggressive driving behaviour (Australian Propensity for Angry Driving AusPADS). Purpose designed items asked for drivers’ ‘most likely’ thought in response to AusPADS scenarios. Response options were equivalent to causal attributions about the other driver. Patterns in endorsements of attribution responses to the scenarios suggested that drivers tended to adopt a particular perception of the driving of others regardless of the depicted circumstances: a driving attributional style. No gender or age differences were found for attributional style. Significant differences were detected between attributional styles for driving anger and endorsement of aggressive responses to driving situations. Drivers who attributed the on-road event to the other being an incompetent or dangerous driver had significantly higher driving anger scores and endorsed significantly more aggressive driving responses than those drivers who attributed other driver’s behaviour to mistakes. In contrast, drivers who gave others the ‘benefit of the doubt’ endorsed significantly less aggressive driving responses than either of these other two groups, suggesting that this style is protective.

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Objective Ankylosing spondylitis (AS) is a highly heritable common inflammatory arthritis that targets the spine and sacroiliac joints of the pelvis, causing pain and stiffness and leading eventually to joint fusion. Although previous studies have shown a strong association of IL23R with AS in white Europeans, similar studies in East Asian populations have shown no association with common variants of IL23R, suggesting either that IL23R variants have no role or that rare genetic variants contribute. The present study was undertaken to screen IL23R to identify rare variants associated with AS in Han Chinese. Methods A 170-kb region containing IL23R and its flanking regions was sequenced in 50 patients with AS and 50 ethnically matched healthy control subjects from a Han Chinese population. In addition, the 30-kb region of peak association in white Europeans was sequenced in 650 patients with AS and 1,300 healthy controls. Validation genotyping was undertaken in 846 patients with AS and 1,308 healthy controls. Results We identified 1,047 variants, of which 729 were not found in the dbSNP genomic build 130. Several potentially functional rare variants in IL23R were identified, including one nonsynonomous single-nucleotide polymorphism (nsSNP), Gly149Arg (position 67421184 GA on chromosome 1). Validation genotyping showed that the Gly149Arg variant was associated with AS (odds ratio 0.61, P = 0.0054). Conclusion This is the first study to implicate rare IL23R variants in the pathogenesis of AS. The results identified a low-frequency nsSNP with predicted loss-of-function effects that was protectively associated with AS in Han Chinese, suggesting that decreased function of the interleukin-23 (IL-23) receptor protects against AS. These findings further support the notion that IL-23 signaling has an important role in the pathogenesis of AS.

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Background Biochemical systems with relatively low numbers of components must be simulated stochastically in order to capture their inherent noise. Although there has recently been considerable work on discrete stochastic solvers, there is still a need for numerical methods that are both fast and accurate. The Bulirsch-Stoer method is an established method for solving ordinary differential equations that possesses both of these qualities. Results In this paper, we present the Stochastic Bulirsch-Stoer method, a new numerical method for simulating discrete chemical reaction systems, inspired by its deterministic counterpart. It is able to achieve an excellent efficiency due to the fact that it is based on an approach with high deterministic order, allowing for larger stepsizes and leading to fast simulations. We compare it to the Euler τ-leap, as well as two more recent τ-leap methods, on a number of example problems, and find that as well as being very accurate, our method is the most robust, in terms of efficiency, of all the methods considered in this paper. The problems it is most suited for are those with increased populations that would be too slow to simulate using Gillespie’s stochastic simulation algorithm. For such problems, it is likely to achieve higher weak order in the moments. Conclusions The Stochastic Bulirsch-Stoer method is a novel stochastic solver that can be used for fast and accurate simulations. Crucially, compared to other similar methods, it better retains its high accuracy when the timesteps are increased. Thus the Stochastic Bulirsch-Stoer method is both computationally efficient and robust. These are key properties for any stochastic numerical method, as they must typically run many thousands of simulations.