A new model to analyze metaphyseal bone healing in mice

Background: Despite the increasing clinical problems with metaphyseal fractures, most experimental studies investigate the healing of diaphyseal fractures. Although the mouse would be the preferable species to study the molecular and genetic aspects of metaphyseal fracture healing, a murine model does not exist yet. Using a special locking plate system, we herein introduce a new model, which allows the analysis of metaphyseal bone healing in mice. Methods: In 24 CD-1 mice the distal metaphysis of the femur was osteotomized. After stabilization with the locking plate, bone repair was analyzed radiologically, biomechanically, and histologically after 2 (n = 12) and 5 wk (n = 12). Additionally, the stiffness of the bone-implant construct was tested biomechanically ex vivo. Results: The torsional stiffness of the bone-implant construct was low compared with nonfractured control femora (0.23 ± 0.1 Nmm/°versus 1.78 ± 0.15 Nmm/°, P < 0.05). The cause of failure was a pullout of the distal screw. At 2 wk after stabilization, radiological analysis showed that most bones were partly bridged. At 5 wk, all bones showed radiological union. Accordingly, biomechanical analyses revealed a significantly higher torsional stiffness after 5 wk compared with that after 2 wk. Successful healing was indicated by a torsional stiffness of 90% of the contralateral control femora. Histological analyses showed new woven bone bridging the osteotomy without external callus formation and in absence of any cartilaginous tissue, indicating intramembranous healing. Conclusion: With the model introduced herein we report, for the first time, successful metaphyseal bone repair in mice. The model may be used to obtain deeper insights into the molecular mechanisms of metaphyseal fracture healing. © 2012 Elsevier Inc. All rights reserved.

The relationship between chronic disease self-efficacy and nutritional status, functional ability and quality of life in older adults at risk of hospital readmission

Background and significance: Older adults with chronic diseases are at increasing risk of hospital admission and readmission. Approximately 75% of adults have at least one chronic condition, and the odds of developing a chronic condition increases with age. Chronic diseases consume about 70% of the total Australian health expenditure, and about 59% of hospital events for chronic conditions are potentially preventable. These figures have brought to light the importance of the management of chronic disease among the growing older population. Many studies have endeavoured to develop effective chronic disease management programs by applying social cognitive theory. However, limited studies have focused on chronic disease self-management in older adults at high risk of hospital readmission. Moreover, although the majority of studies have covered wide and valuable outcome measures, there is scant evidence on examining the fundamental health outcomes such as nutritional status, functional status and health-related quality of life. Aim: The aim of this research was to test social cognitive theory in relation to self-efficacy in managing chronic disease and three health outcomes, namely nutritional status, functional status, and health-related quality of life, in older adults at high risk of hospital readmission. Methods: A cross-sectional study design was employed for this research. Three studies were undertaken. Study One examined the nutritional status and validation of a nutritional screening tool; Study Two explored the relationships between participants. characteristics, self-efficacy beliefs, and health outcomes based on the study.s hypothesized model; Study Three tested a theoretical model based on social cognitive theory, which examines potential mechanisms of the mediation effects of social support and self-efficacy beliefs. One hundred and fifty-seven patients aged 65 years and older with a medical admission and at least one risk factor for readmission were recruited. Data were collected from medical records on demographics, medical history, and from self-report questionnaires. The nutrition data were collected by two registered nurses. For Study One, a contingency table and the kappa statistic was used to determine the validity of the Malnutrition Screening Tool. In Study Two, standard multiple regression, hierarchical multiple regression and logistic regression were undertaken to determine the significant influential predictors for the three health outcome measures. For Study Three, a structural equation modelling approach was taken to test the hypothesized self-efficacy model. Results: The findings of Study One suggested that a high prevalence of malnutrition continues to be a concern in older adults as the prevalence of malnutrition was 20.6% according to the Subjective Global Assessment. Additionally, the findings confirmed that the Malnutrition Screening Tool is a valid nutritional screening tool for hospitalized older adults at risk of readmission when compared to the Subjective Global Assessment with high sensitivity (94%), and specificity (89%) and substantial agreement between these two methods (k = .74, p < .001; 95% CI .62-.86). Analysis data for Study Two found that depressive symptoms and perceived social support were the two strongest influential factors for self-efficacy in managing chronic disease in a hierarchical multiple regression. Results of multivariable regression models suggested advancing age, depressive symptoms and less tangible support were three important predictors for malnutrition. In terms of functional status, a standard regression model found that social support was the strongest predictor for the Instrumental Activities of Daily Living, followed by self-efficacy in managing chronic disease. The results of standard multiple regression revealed that the number of hospital readmission risk factors adversely affected the physical component score, while depressive symptoms and self-efficacy beliefs were two significant predictors for the mental component score. In Study Three, the results of the structural equation modelling found that self-efficacy partially mediated the effect of health characteristics and depression on health-related quality of life. The health characteristics had strong direct effects on functional status and body mass index. The results also indicated that social support partially mediated the relationship between health characteristics and functional status. With regard to the joint effects of social support and self-efficacy, social support fully mediated the effect of health characteristics on self-efficacy, and self-efficacy partially mediated the effect of social support on functional status and health-related quality of life. The results also demonstrated that the models fitted the data well with relative high variance explained by the models, implying the hypothesized constructs under discussion were highly relevant, and hence the application for social cognitive theory in this context was supported. Conclusion: This thesis highlights the applicability of social cognitive theory on chronic disease self-management in older adults at risk of hospital readmission. Further studies are recommended to validate and continue to extend the development of social cognitive theory on chronic disease self-management in older adults to improve their nutritional and functional status, and health-related quality of life.

Transforming habitus: Changing self, changing school

Since 2004, Australian Indigenous (Aboriginal and Torres Strait Islander) students at a low socioeconomic area Australian urban secondary school have used participatory action research to investigate issues of disengagement and absenteeism among their peers. Their research revealed that Indigenous students, who made up about 8% to 10% of the school’s population lacked a sense of belonging to the school. The researchers also revealed an apparent official disregard of the academic or sporting achievements of Indigenous students and, more disturbingly, their presence within the school. The young researchers followed up their findings with action to address the issues. These actions have resulted in a positive change of culture across the whole school, with Indigenous students now able to express pride in their heritage and feel some degree of ownership of the school.

The pomegranate cycle : reconfiguring opera through performance, technology & composition

The Pomegranate Cycle is a practice-led enquiry consisting of a creative work and an exegesis. This project investigates the potential of self-directed, technologically mediated composition as a means of reconfiguring gender stereotypes within the operatic tradition. This practice confronts two primary stereotypes: the positioning of female performing bodies within narratives of violence and the absence of women from authorial roles that construct and regulate the operatic tradition. The Pomegranate Cycle redresses these stereotypes by presenting a new narrative trajectory of healing for its central character, and by placing the singer inside the role of composer and producer. During the twentieth and early twenty-first century, operatic and classical music institutions have resisted incorporating works of living composers into their repertory. Consequently, the canon’s historic representations of gender remain unchallenged. Historically and contemporarily, men have almost exclusively occupied the roles of composer, conductor, director and critic, and therefore men have regulated the pedagogy, performance practices, repertoire and organisations that sustain classical music. In this landscape, women are singers, and few have the means to challenge the constructions of gender they are asked to reproduce. The Pomegranate Cycle uses recording technologies as the means of driving change because these technologies have already challenged the regulation of the classical tradition by changing people’s modes of accessing, creating and interacting with music. Building on the work of artists including Phillips and van Veen, Robert Ashley and Diamanda Galas, The Pomegranate Cycle seeks to broaden the definition of what opera can be. This work examines the ways in which the operatic tradition can be hybridised with contemporary musical forms such as ambient electronica, glitch, spoken word and concrete sounds as a way of bringing the form into dialogue with contemporary music cultures. The ultilisation of other sound cultures within the context of opera enables women’s voices and stories to be presented in new ways, while also providing a point of friction with opera’s traditional storytelling devices. The Pomegranate Cycle simulates aesthetics associated with Western art music genres by drawing on contemporary recording techniques, virtual instruments and sound-processing plug-ins. Through such simulations, the work disrupts the way virtuosic human craft has been used to generate authenticity and regulate access to the institutions that protect and produce Western art music. The DIY approach to production, recording, composition and performance of The Pomegranate Cycle demonstrates that an opera can be realised by a single person. Access to the broader institutions which regulate the tradition are not necessary. In short, The Pomegranate Cycle establishes that a singer can be more than a voice and a performing body. She can be her own multimedia storyteller. Her audience can be anywhere.

The quantum inspired modelling of changing attitudes and self-organising societies

We utilise the well-developed quantum decision models known to the QI community to create a higher order social decision making model. A simple Agent Based Model (ABM) of a society of agents with changing attitudes towards a social issue is presented, where the private attitudes of individuals in the system are represented using a geometric structure inspired by quantum theory. We track the changing attitudes of the members of that society, and their resulting propensities to act, or not, in a given social context. A number of new issues surrounding this "scaling up" of quantum decision theories are discussed, as well as new directions and opportunities.

Influence of plate bending stiffness on mechanical properties of healing fracture, mouse femora

Mechanically well-defined stabilization systems have only recently become available, providing standardized conditions for studying the role of the mechanical environment on mouse bone fracture healing. The aim of this study was to characterize the time course of strength recovery and callus development of mouse femoral osteotomies stabilized with either low or high flexibility (in bending and torsion) internal fixation plates. Animals were euthanized and femora excised at 14, 21, and 28 days post-osteotomy for microCT analysis and torsional strength testing. While a larger mineralized callus was observed in osteotomies under more flexible conditions at all time points, the earlier bridging of the mineralized callus under less flexible conditions by 1 week resulted in an earlier recovery of torsional strength in mice stabilized with low flexibility fixation. Ultimate torque values for these bones were significantly higher at 14 and 21 days post-osteotomy compared to bones with the more flexible stabilization. Our study confirms the high reproducibility of the results that are achieved with this new implant system, therefore making it ideal for studying the influence of the mechanical environment on murine fracture healing under highly standardized conditions.

Numerical simulation of a fractional mathematical model for epidermal wound healing

A number of mathematical models investigating certain aspects of the complicated process of wound healing are reported in the literature in recent years. However, effective numerical methods and supporting error analysis for the fractional equations which describe the process of wound healing are still limited. In this paper, we consider numerical simulation of fractional model based on the coupled advection-diffusion equations for cell and chemical concentration in a polar coordinate system. The space fractional derivatives are defined in the Left and Right Riemann-Liouville sense. Fractional orders in advection and diffusion terms belong to the intervals (0; 1) or (1; 2], respectively. Some numerical techniques will be used. Firstly, the coupled advection-diffusion equations are decoupled to a single space fractional advection-diffusion equation in a polar coordinate system. Secondly, we propose a new implicit difference method for simulating this equation by using the equivalent of the Riemann-Liouville and Gr¨unwald-Letnikov fractional derivative definitions. Thirdly, its stability and convergence are discussed, respectively. Finally, some numerical results are given to demonstrate the theoretical analysis.

The relationship between cognitive ability, insight and self-regulatory behaviors: Findings from the older driver population

Self-regulation is often promoted as a coping strategy that may allow older drivers to drive safely for longer. Self-regulation depends upon drivers making an accurate assessment of their own ability and having a willingness to practice self-regulatory behaviors to compensate for changes in ability. The current study explored the relationship between older drivers’ cognitive ability, their driving confidence and their use of self-regulation. An additional study aim was to explore the relationship between these factors and older drivers’ interest in driving programs. Seventy Australian drivers aged 65 years and over completed a questionnaire about their driving and a brief screening measure of cognitive ability (an untimed Clock Drawing Test). While all participants reported high levels of confidence regarding their driving ability, and agreed that they would continue driving in the foreseeable future, a notable proportion performed poorly on the Clock Drawing Test. Compared to older drivers who successfully completed the Clock Drawing Test, those who failed the cognitive test were significantly less likely to report driving self-regulation, and showed significantly less interest in being involved in driving programs. Older drivers with declining cognitive abilities may not be self-regulating their driving. This group also appears to be unlikely to self-refer to driving programs.

They Say You are a Danger But You Are Not: Representations and Construction of the Moral Self in Narratives of 'Dangerous Individuals'

This article is based on an analysis of narratives of 26 offenders with mental health problems living in the United Kingdom. It explores the impact of an ascribed dangerous status and the construction of the self as moral and responsible in response to this label with reference to the literature on denial, deviance disavowal and other “techniques of neutralization” and Goffman's presentation of self. Two dominant strands are identified in relation to the construction of moral self-hood: “Not my fault” and “Good at heart” narratives. “Techniques of neutralization” are widely drawn on, particularly denial of responsibility in the “Not my fault” narratives that seek to explain anti-social behavior with reference to external forces such as a hostile environment inhibiting their ability to control their lives. In contrast, “Good at heart” narratives draw on the essentially good and moral nature of the inner-self. Both are used as evidence of sharing and adhering to moral norms in order to present an acceptable and credible self.

Validation of scales measuring self-efficacy and outcome expectancy in evidence-based practice

Background: Evidence-based practice (EBP) is embraced internationally as an ideal approach to improve patient outcomes and provide cost-effective care. However, despite the support for and apparent benefits of evidence-based practice, it has been shown to be complex and difficult to incorporate into the clinical setting. Research exploring implementation of evidence-based practice has highlighted many internal and external barriers including clinicians’ lack of knowledge and confidence to integrate EBP into their day-to-day work. Nurses in particular often feel ill-equipped with little confidence to find, appraise and implement evidence. Aims: The following study aimed to undertake preliminary testing of the psychometric properties of tools that measure nurses’ self-efficacy and outcome expectancy in regard to evidence-based practice. Methods: A survey design was utilised in which nurses who had either completed an EBP unit or were randomly selected from a major tertiary referral hospital in Brisbane, Australia were sent two newly developed tools: 1) Self-efficacy in Evidence-Based Practice (SE-EBP) scale and 2) Outcome Expectancy for Evidence-Based Practice (OE-EBP) scale. Results: Principal Axis Factoring found three factors with eigenvalues above one for the SE-EBP explaining 73% of the variance and one factor for the OE-EBP scale explaining 82% of the variance. Cronbach’s alpha for SE-EBP, three SE-EBP factors and OE-EBP were all >.91 suggesting some item redundancy. The SE-EBP was able to distinguish between those with no prior exposure to EBP and those who completed an introductory EBP unit. Conclusions: While further investigation of the validity of these tools is needed, preliminary testing indicates that the SE-EBP and OE-EBP scales are valid and reliable instruments for measuring health professionals’ confidence in the process and the outcomes of basing their practice on evidence.