28 resultados para order-disorder phenomena

em Deakin Research Online - Australia


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We study an Fe-18Al (at.%) alloy after various thermal treatments at different times (24-336 h) and temperatures (250-1100 °C) to determine the nature of the so-called 'komplex' phase state (or "K-state"), which is common to other alloy systems having compositions at the boundaries of known order-disorder transitions and is characterised by heterogeneous short-range-ordering (SRO). This has been done by direct observation using atom probe tomography (APT), which reveals that nano-sized, ordered regions/particles do not exist. Also, by employing shell-based analysis of the three-dimensional atomic positions, we have determined chemically sensitive, generalised multicomponent short-range order (GM-SRO) parameters, which are compared with published pairwise SRO parameters derived from bulk, volume-averaged measurement techniques (e.g. X-ray and neutron scattering, Mössbauer spectroscopy) and combined ab-initio and Monte Carlo simulations. This analysis procedure has general relevance for other alloy systems where quantitative chemical-structure evaluation of local atomic environments is required to understand ordering and partial ordering phenomena that affect physical and mechanical properties.

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Disulfides are conventionally viewed as structurally stabilizing elements in proteins but emerging evidence suggests two disulfide subproteomes exist. One group mediates the well known role of structural stabilization. A second redox-active group are best known for their catalytic functions but are increasingly being recognized for their roles in regulation of protein function. Redox-active disulfides are, by their very nature, more susceptible to reduction than structural disulfides; and conversely, the Cys pairs that form them are more susceptible to oxidation. In this study, we searched for potentially redox-active Cys Pairs by scanning the Protein Data Bank for structures of proteins in alternate redox states. The PDB contains over 1134 unique redox pairs of proteins, many of which exhibit conformational differences between alternate redox states. Several classes of structural changes were observed, proteins that exhibit: disulfide oxidation following expulsion of metals such as zinc; major reorganisation of the polypeptide backbone in association with disulfide redox-activity; order/disorder transitions; and changes in quaternary structure. Based on evidence gathered supporting disulfide redox activity, we propose disulfides present in alternate redox states are likely to have physiologically relevant redox activity.

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This article provides a brief commentary on Pfaff et al's timely review of the relations between mechanisms of CNS arousal and mechanisms of stress. Pfaff and colleagues use the review as a platform to propose the existence of a coherent stress-arousal state. We suggest that this proposal is, on a number of grounds, flawed. In turn, we counter that the while the states of stress and arousal are related they are as entities fundamentally separate. Moreover, we propose that any productive attempt to unite the two states must acknowledge the importance of and therefore centrally include higher order integrative phenomena, such as, appraisal.

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The establishment of an elite national Australian soccer league has been accompanied by an unprecedented growth in popularity for the world game in several Australian cities. Such growth presents numerous challenges for public order maintenance, particularly in light of the widespread concern over the relationship between soccer, disasters in major closed venues and violence. After outlining the emerging issues, and the extant Australian research into the phenomena of policing and sports crowd disorder, this study offers a knowledge based approach to foster informed, reflective and collaborative policing in elite and sub-elite soccer venues. Rather than advocating a fundamental shift in the current public order policing paradigm, we suggest drawing on elements of best practice that are currently adopted in other Australian sporting and public order settings and appropriate overseas experience to facilitate a better understanding of the dynamics of Australian soccer fandom. The result should be the promotion of safer yet exciting events at which interactive crowd management based on harm minimization principles are key features.

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A survey of parents/caregivers of a child with an autism spectrum disorder (ASD) was conducted to examine the relationship between ASD characteristics, family functioning and coping strategies. Having a child with ASD places considerable stress on the family. Primary caregivers of a child with ASD from a regional and rural area in Victoria, Australia (N = 53) were surveyed concerning their child with ASD, family functioning (adaptability and cohesion), marital satisfaction, self-esteem and coping strategies. Results suggest that these caregivers had healthy self-esteem, although they reported somewhat lower marital happiness, family cohesion and family adaptability than did norm groups. Coping strategies were not significant predictors of these outcome variables. Results highlight the need for support programmes to target family and relationship variables as well as ASD children and their behaviours, in order to sustain the family unit and improve quality of life for parents and caregivers as well as those children.

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Pessimistic attitudes and reactive behavioural management strategies act as a major barrier to effective service provision for patients with borderline personality disorder. This paper reviews research on countertransference reactions (negative professional attitudes) towards these patients and the professional response to the common presentation of self harm in this particular client group. The psychotherapeutic treatment of patients with borderline personality disorder is complex and both professionally and personally demanding. A clinical framework is proposed that enables clinicians to develop a more nuanced and empathic understanding of self harm within the context of personality disorder in order to facilitate enhanced therapeutic engagement with these challenging patients. A clinical case study illustrates the use of this framework and the potential for enhanced therapeutic management in conjunction with the recognition and reduction of clinician indifference and rejection, thus improving patient outcomes. (editor abstract)Pessimistic attitudes and reactive behavioural management strategies act as a major barrier to effective service provision for patients with borderline personality disorder. This paper reviews research on countertransference reactions (negative professional attitudes) towards these patients and the professional response to the common presentation of self harm in this particular client group. The psychotherapeutic treatment of patients with borderline personality disorder is complex and both professionally and personally demanding. A clinical framework is proposed that enables clinicians to develop a more nuanced and empathic understanding of self harm within the context of personality disorder in order to facilitate enhanced therapeutic engagement with these challenging patients. A clinical case study illustrates the use of this framework and the potential for enhanced therapeutic management in conjunction with the recognition and reduction of clinician indifference and rejection, thus improving patient outcomes.

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This thesis describes the exploration and the development of computational means to investigate the behaviour of design objects before they are available for investigation in the physical world. The motivation is to inform the design process about the design object's performance in order to achieve better--more performance-oriented--design outcomes in the sense of energy efficiency and comfort performance than can be achieved by conventional design techniques.

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The pivotal role of inflated responsibility beliefs in the maintenance and treatment of obsessive-compulsive disorder (OCD) has been clearly demonstrated (Rachman, 1993; Salkovskis, 1998; Shafran, 1997; van Oppen & Arntz, 1994). Yet little is known about the origins of these beliefs, their contribution to a sense of inflated responsibility or the symptoms of OCD, or the contribution of personality to inflated responsibility and to OCD, The aims of this thesis were to investigate a model of the inter-relationships among the personality dimensions of neuroticism and psychoticism, inflated responsibility and OCD, and the origins of inflated responsibility to inflated responsibility and to OCD. In order to achieve these aims, a scale was developed to assess the origins of inflated responsibility based upon the five pathways proposed by Salkovskis, Shafran, Rachman, and Freeston (1999) and the additional domains of guilt, vigilance and thought-action fusion (Shafran, Thordarson, & Rachman, 1996; Shafran, Watkins & Charman, 1996; Tallis, 1994). Eighty-four participants with OCD (age M = 43.36) and 74 control participants (age M =37.14) volunteered to participate in the two studies of this thesis. The aim of Study 1 was to develop and validate a measure of the Origins of Inflated Responsibility (OIR). The results of the first study yielded a 25-ttem scale, the Origins of Inflated Responsibility Questionnaire (OIRQ) with five independent factors: responsibility, strictness, protection from responsibility, critical incidents, and peer blame which demonstrated both internal reliability and temporal stability over a 2-week period. In Study 2, participants also completed the Responsibility Attitudes Scale (Salkovskis, Wroe, Gledhill, Morrison, Forrester, Richards, ct al. (2000) (a measure of inflated responsibility), the Padua Inventory (Sanavio, 1988) (to measure of the symptoms of OCD)y and the Eysenck Personality Inventory-Revised (Eysenck & Eysenck, 1991). Multivariatc Analysis of Variance revealed that the OCD group scored higher on all variables than the control group except for strictness where the groups were not different, and psychoticism where the OCD group scored lower. A series of Multiple Regression analyses revealed that both group and the OIR contributed to inflated responsibility (R2 = .56). When all variables, OIR, inflated responsibility and neuroticism were entered as predictors of OCD, 60% of the variance in OCD was explained however, 49% of the variance was shared by the independent variables suggesting the presence of some underlying construct. Structural Equation Modelling, where all the constructs in the model were examined simultaneously, revealed that neuroticism contributed to the OIR, inflated responsibility and OCD. The OIR were also significant predictors of inflated responsibility and indirectly through inflated responsibility predictive of OCD. The OIR also directly predicted OCD and when the total effects are considered, their contribution was greater than the total effect for inflated responsibility alone. The results of these studies provide good support for the origins of inflated responsibility proposed by Salkovskis et al. (1999), as measured by the OIRQ developed for use in the current thesis. The results also support the contribution of inflated responsibility and neuroticism, as well as the OIR, to OCD, The large amount of variance shared by the OIR, inflated responsibility and neuroticism suggest that there might be some underlying construct, perhaps of a biopsychosocial nature, that requires further investigation for its role in the onset and maintenance of OCD. The clinical relevance of these findings is discussed in terms of early prevention strategies and interventions.

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The term ‘switching’ is often used in bipolar disorder when describing polarity changes in bipolar disorder, but this term is ambiguous and imprecise, and is sometimes used interchangeably with the term ‘cycling’. Furthermore, polarity changes in bipolar disorder can be understood in different ways, because their clinical manifestations range from the emergence of subthreshold symptoms to a full episode of the opposite pole. Besides the need to tighten the meaning of the term ‘switching’, this paper also argues that switching does not adequately describe the complex phenomena that occur with course aggravation of bipolar disorder, such as alteration in episode frequency or amplitude. A more-fine grained approach to course aggravation in bipolar disorder is proposed, which incorporates trans-polar switching, index polarity aggravation, as well as alterations in episodic amplitude, episodic duration, and interepisode length. This approach has the potential to capture a broader, more fine-grained and clinically relevant picture of the process of aggravation of the bipolar cycle.

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Aim: This paper will describe the rationale for, and importance of, psychological interventions for young people early in the course of bipolar disorder.
Methods: Emerging literature in this field will be discussed in addition to describing specific clinical challenges and opportunities with this population.
Results: In order to be more developmentally appropriate for young people with bipolar disorder, eight aspects of clinical work which may require modification were identified.
Conclusions: The evidence base for the effectiveness of psychological interventions for people diagnosed with bipolar disorder is growing. However, some aspects relating to working with adults with bipolar disorder require modification to be effective in working with young people early in the course of the disorder.

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Purpose
Eating disorders are chronic conditions that require ongoing, high level care. Despite the chronic nature of eating disorders, to date, previous research examining eating disorder carer burden and psychological distress has been cross-sectional only. Therefore, the current study aimed to conduct a preliminary longitudinal examination of the predictors of carer burden and psychological distress for carers of those with an eating disorder.
Methods
A self-report, quantitative questionnaire approach was utilised. Forty-two carers completed three self-report questionnaires over a period of 9 months (initial, 4½ and 9 months) assessing carer burden, psychological distress, carer needs, expressed emotion, coping strategies and social support.
Results
Maladaptive coping, expressed emotion and carer needs were significant longitudinal predictors of carer burden. Carer psychological distress could not be predicted longitudinally.
Conclusions
In order to reduce carer burden, interventions should test whether reducing maladaptive coping strategies, expressed emotion and addressing carer needs lead to lower carer burden and distress.

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This study mainly focuses on the terminal sliding mode control (TSMC) strategy design, including an adaptive terminal sliding mode control (ATSMC) and an exact-estimator-based terminal sliding mode control (ETSMC) for second-order nonlinear dynamical systems. In the ATSMC system, an adaptive bound estimation for the lump uncertainty is proposed to ensure the system stability. On the other hand, an exact estimator is designed for exact estimating system uncertainties to solve the trouble of chattering phenomena caused by a sign function in ATSMC law in despite of the utilization of a fixed value or an adaptive tuning algorithm for the lumped uncertainty bound. The effectiveness of the proposed control schemes can be verified in numerical simulations.

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This study assessed the degree of equivalence between paper and Internet administration of three measures of panic and agoraphobia-related cognition and behavior: Body Sensations Questionnaire (BSQ), Agoraphobic Cognitions Questionnaire (ACQ), and Mobility Inventory (MI). Participants were 110 people with panic disorder who had registered for an Internet-based treatment program in Sweden (n = 54) or Australia (n = 56). Participants were randomly assigned to complete the questionnaires via the differing administration formats in a counterbalanced order. Results showed broadly equivalent psychometric properties across administrations, with strong significant intraclass correlations between them, and comparable Cronbach's alpha coefficients. A significant mean difference between administration formats was found for the BSQ only. In contrast to previous research, Internet administration did not generate higher scores than paper administration. No effect was found for order of administration. The findings suggest that each questionnaire can be validly administered via the Internet and used with confidence.