Effects of strain artefacts arising from a pre-defined callus domain in models of bone healing mechanobiology

Iterative computational models have been used to investigate the regulation of bone fracture healing by local mechanical conditions. Although their predictions replicate some mechanical responses and histological features, they do not typically reproduce the predominantly radial hard callus growth pattern observed in larger mammals. We hypothesised that this discrepancy results from an artefact of the models’ initial geometry. Using axisymmetric finite element models, we demonstrated that pre-defining a field of soft tissue in which callus may develop introduces high deviatoric strains in the periosteal region adjacent to the fracture. These bone-inhibiting strains are not present when the initial soft tissue is confined to a thin periosteal layer. As observed in previous healing models, tissue differentiation algorithms regulated by deviatoric strain predicted hard callus forming remotely and growing towards the fracture. While dilatational strain regulation allowed early bone formation closer to the fracture, hard callus still formed initially over a broad area, rather than expanding over time. Modelling callus growth from a thin periosteal layer successfully predicted the initiation of hard callus growth close to the fracture site. However, these models were still susceptible to elevated deviatoric strains in the soft tissues at the edge of the hard callus. Our study highlights the importance of the initial soft tissue geometry used for finite element models of fracture healing. If this cannot be defined accurately, alternative mechanisms for the prediction of early callus development should be investigated.

Factors influencing the provision of end-of-life care in critical care settings : development and testing of a survey instrument

Aim. To develop and psychometrically test a survey instrument to identify the factors influencing the provision of end-of-life care by critical care nurses. Background. Following a decision to withdraw life-sustaining treatment, critical care nurses remain with the patient and their family providing end-of-life care. Identification of factors influencing the provision of this care can give evidence to inform practice development and support nurses. Design. A cross-sectional survey of critical care nurses. Method. An online survey was developed, reviewed by an expert panel and pilot tested to obtain preliminary evidence of its reliability and validity. In May 2011, a convenience sample of critical care nurses (n = 392, response rate 25%) completed the survey. The analytical approach to data obtained from the 58 items measured on a Likert scale included exploratory factor analysis and descriptive statistics. Results. Exploratory factor analysis identified eight factors influencing the provision of end-of-life care: emotional support for nurses, palliative values, patient and family preferences, resources, organizational support, care planning, knowledge and preparedness. Internal consistency of each latent construct was deemed satisfactory. The results of descriptive statistics revealed a strong commitment to the inclusion of families in end-of-life care and the value of this care in the critical care setting. Conclusion. This paper reports preliminary evidence of the psychometric properties of a new survey instrument. The findings may inform practice development opportunities to support critical care nurses in the provision of endof- life care and improve the care that patients and their families receive.

Development and integration of a solar powered unmanned aerial vehicle and a wireless sensor network to monitor greenhouse gases

Measuring gases for environmental monitoring is a demanding task that requires long periods of observation and large numbers of sensors. Wireless Sensor Networks (WSNs) and Unmanned Aerial Vehicles (UAVs) currently represent the best alternative to monitor large, remote, and difficult access areas, as these technologies have the possibility of carrying specialized gas sensing systems. This paper presents the development and integration of a WSN and an UAV powered by solar energy in order to enhance their functionality and broader their applications. A gas sensing system implementing nanostructured metal oxide (MOX) and non-dispersive infrared sensors was developed to measure concentrations of CH4 and CO2. Laboratory, bench and field testing results demonstrate the capability of UAV to capture, analyze and geo-locate a gas sample during flight operations. The field testing integrated ground sensor nodes and the UAV to measure CO2 concentration at ground and low aerial altitudes, simultaneously. Data collected during the mission was transmitted in real time to a central node for analysis and 3D mapping of the target gas. The results highlights the accomplishment of the first flight mission of a solar powered UAV equipped with a CO2 sensing system integrated with a WSN. The system provides an effective 3D monitoring and can be used in a wide range of environmental applications such as agriculture, bushfires, mining studies, zoology and botanical studies using a ubiquitous low cost technology.

Development and validation of the Self-Gifting Consumer Behaviour scale

Self-gifting consumer behaviour (SGCB) is on the rise as consumers seek reward and therapeutic benefits from their shopping experiences. SGCB is defined as personally symbolic, self-communication through special indulgences, which tend to be premeditated and highly context bound. Prior research into the measurement of this growing behavioural phenomenon has been fragmented because of differences in conceptualisation. This research builds upon the prior literature and through a series of qualitative and quantitative studies, develops a valid, multidimensional measure of SGCB that will be useful for future quantitative inquiry into self-gifting consumption.

Building cross-scale models of epigenetic mechanisms

Epigenetic changes correspond to heritable modifications of the chromosome structure, which do not involve alteration of the DNA sequence but do affect gene expression. These mechanisms play an important role in normal cell differentiation, but aberration is associated also with several diseases, including cancer and neural disorders. In consequence, despite intensive studies in recent years, the contribution of modifications remains largely unquantified due to overall system complexity and insufficient data. Computational models can provide powerful auxiliary tools to experimentation, not least as scales from the sub-cellular through cell populations (or to networks of genes) can be spanned. In this paper, the challenges to development, of realistic cross-scale models, are discussed and illustrated with respect to current work.

Multi-parametric hydrogels support 3D in vitro bioengineered microenvironment models of tumour angiogenesis

Tumour microenvironment greatly influences the development and metastasis of cancer progression. The development of three dimensional (3D) culture models which mimic that displayed in vivo can improve cancer biology studies and accelerate novel anticancer drug screening. Inspired by a systems biology approach, we have formed 3D in vitro bioengineered tumour angiogenesis microenvironments within a glycosaminoglycan-based hydrogel culture system. This microenvironment model can routinely recreate breast and prostate tumour vascularisation. The multiple cell types cultured within this model were less sensitive to chemotherapy when compared with two dimensional (2D) cultures, and displayed comparative tumour regression to that displayed in vivo. These features highlight the use of our in vitro culture model as a complementary testing platform in conjunction with animal models, addressing key reduction and replacement goals of the future. We anticipate that this biomimetic model will provide a platform for the in-depth analysis of cancer development and the discovery of novel therapeutic targets.

Environmental conditions are important for establishing and evaluating pre-clinical models of GVHD

GVHD remains the major complication of allo-HSCT. Murine models are the primary system used to understand GVHD, and to develop potential therapies. Several factors are critical for GVHD in these models; including histo- compatibility, conditioning regimen, and T-cell number. We serendipitously found that environmental factors such as the caging system and bedding also significantly impact the kinetics of GVHD in these models. This is important because such factors may influence the experimental conditions required to cause GVHD and how mice respond to various treatments. Consequently, this is likely to alter interpretation of results between research groups, and the perceived effectiveness of experimental therapies.

Learning to lead: The development and testing of a model of leadership learning

Drawing upon an action learning perspective, we hypothesized that a leader’s learning of project leadership skills would be related to facilitative leadership, team reflexivity, and team performance. Secondly, we proposed that new and experienced leaders would differ in the amount they learn from their current and recent experience as project managers, and in the strength of the relationship between their self-reported learning, facilitative leadership, and team reflexivity. We conducted a 1-year longitudinal study of 50 R&D teams, led by 25 new and 25 experienced leaders, with 313 team members and 22 project customers, collecting both quantitative and qualitative data. We found evidence of a significant impact of the leader’s learning on subsequent facilitative leadership and team performance 8 and 12 months later, suggesting a lag between learning leadership skills and translating these skills into leadership behavior. The findings contribute to an understanding of how leaders consolidate their learned experience into facilitative leadership behavior.

Emergency department models of care in the context of care quality and cost: A systematic review

To identify current ED models of care and their impact on care quality, care effectiveness, and cost. A systematic search of key health databases (Medline, CINAHL, Cochrane, EMbase) was conducted to identify literature on ED models of care. Additionally, a focused review of the contents of 11 international and national emergency medicine, nursing and health economic journals (published between 2010 and 2013) was undertaken with snowball identification of references of the most recent and relevant papers. Articles published between 1998 and 2013 in the English language were included for initial review by three of the authors. Studies in underdeveloped countries and not addressing the objectives of the present study were excluded. Relevant details were extracted from the retrieved literature, and analysed for relevance and impact. The literature was synthesised around the study's main themes. Models described within the literature mainly focused on addressing issues at the input, throughput or output stages of ED care delivery. Models often varied to account for site specific characteristics (e.g. onsite inpatient units) or to suit staffing profiles (e.g. extended scope physiotherapist), ED geographical location (e.g. metropolitan or rural site), and patient demographic profile (e.g. paediatrics, older persons, ethnicity). Only a few studies conducted cost-effectiveness analysis of service models. Although various models of delivering emergency healthcare exist, further research is required in order to make accurate and reliable assessments of their safety, clinical effectiveness and cost-effectiveness.

Applying metaethical and normative claims of moral relativism to (shareholder and stakeholder) models of corporate governance

There has, in recent decades, been considerable scholarship regarding the moral aspects of corporate governance,and differences in corporate governance practices around the world have been widely documented and investigated. In such a context, the claims associated with moral relativism are relevant. The purpose of this paper is to provide a detailed consideration of how the metaethical and normative claims of moral relativism in particular can be applied to corporate governance. This objective is achieved, firstly, by reviewing what is meant by metaethical moral relativism and identifying two ways in which the metaethical claim can be assessed. The possibility of a single, morally superior model of corporate governance is subsequently considered through an analysis of prominent works justifying the shareholder and stakeholder approaches, together with a consideration of academic agreement in this area. The paper then draws on the work of Wong (Moral relativity, University of California Press, Berkeley, CA, 1984, A companion to ethics, Blackwell, Malden, 1993, Natural moralities: A defense of pluralistic relativism,Oxford University Press, Oxford, 2006), firstly in providing an argument supporting metaethical moral relativism and secondly regarding values of tolerance and/or accommodation that can contribute to the normative claim. The paper concludes by proposing an argument that it is morally wrong to impose a model of corporate governance where there are differences in moral judgements relevant to corporate governance, or to interfere with a model in similar circumstances, and closes with consideration of the argument’s implications.

Neurodevelopmental animal models of schizophrenia: Effects on prepulse inhibition

Epidemiological studies have shown increased incidence of schizophrenia in patients subjected to different forms of pre- or perinatal stress. However, as the onset of schizophrenic illness does not usually occur until adolescence or early adulthood, it is not yet fully understood how disruption of early brain development may ultimately lead to malfunction years later. In order to elucidate a possible role for neurodevelopmental factors in the pathogenesis of schizophrenia and to highlight potential new treatments, animal models are needed. Prepulse inhibition (PPI) is a model of sensorimotor gating mechanisms in the brain. It is disrupted in schizophrenia patients and the disruption can be reversed with atypical antipsychotics. It has been widely used in animal studies to explore central mechanisms possibly involved in schizophrenia. There has been a recent surge of behavioural and neurochemical animal studies on neurodevelopmental models, particularly on the effects of postweaning isolation, maternal separation and neonatal lesions of the hippocampus. In these models, long lasting alterations in behaviour and/or molecular changes in specific brain regions are observed, comparable to those seen in schizophrenia. The aim of this article is to critically review the available literature on such neurodevelopmental animal models with special focus on the effects on PPI and brain regions that are putatively involved in regulation of PPI.

The Step approach to Message Design and Testing (SatMDT): A conceptual framework to guide the development and evaluation of persuasive health messages

This paper provides an important and timely overview of a conceptual framework designed to assist with the development of message content, as well as the evaluation, of persuasive health messages. While an earlier version of this framework was presented in a prior publication by the authors in 2009, important refinements to the framework have seen it evolve in recent years, warranting the need for an updated review. This paper outlines the Step approach to Message Design and Testing (or SatMDT) in accordance with the theoretical evidence which underpins, as well as empirical evidence which demonstrates the relevance and feasibility, of each of the framework’s steps. The development and testing of the framework have thus far been based exclusively within the road safety advertising context; however, the view expressed herein is that the framework may have broader appeal and application to the health persuasion context.

The development and refinement of the practice domain framework as a conceptual tool for understanding and guiding social care practice

This study identified the common factors that influence social care practice across disciplines (such as social work and psychology), practice fields, and geographical contexts and further developed the Practice Domain Framework as an empirically-based conceptual framework to assist practitioners in understanding practice complexities. The framework has application in critical reflection, professional supervision, interdisciplinary understanding, teamwork, management, teaching and research. A mixed-methods design was used to identify the components and structure of the refined framework. Eighteen influential factors were identified and organised into eight domains: the Societal, Structural, Organisational, Practice Field, Professional Practice, Accountable Practice, Community of Place, and Personal.