Modelling the interaction of keratinocytes and fibroblasts during normal and abnormal wound healing processes

The crosstalk between fibroblasts and keratinocytes is a vital component of the wound healing process, and involves the activity of a number of growth factors and cytokines. In this work, we develop a mathematical model of this crosstalk in order to elucidate the effects of these interactions on the regeneration of collagen in a wound that heals by second intention. We consider the role of four components that strongly affect this process: transforming growth factor-beta, platelet-derived growth factor, interleukin-1 and keratinocyte growth factor. The impact of this network of interactions on the degradation of an initial fibrin clot, as well as its subsequent replacement by a matrix that is mainly comprised of collagen, is described through an eight-component system of nonlinear partial differential equations. Numerical results, obtained in a two-dimensional domain, highlight key aspects of this multifarious process such as reepithelialisation. The model is shown to reproduce many of the important features of normal wound healing. In addition, we use the model to simulate the treatment of two pathological cases: chronic hypoxia, which can lead to chronic wounds; and prolonged inflammation, which has been shown to lead to hypertrophic scarring. We find that our model predictions are qualitatively in agreement with previously reported observations, and provide an alternative pathway for gaining insight into this complex biological process.

Teaching undergraduate students community nursing : using action research to increase engagement and learning

Nurses play a pivotal role in responding to the changing needs of community health care. Therefore, nursing education must be relevant, responsive, and evidence based. We report a case study of curriculum development in a community nursing unit embedded within an undergraduate nursing degree. We used action research to develop, deliver, evaluate, and redesign the curriculum. Feedback was obtained through self-reflection, expert opinion from community stakeholders, formal student evaluation, and critical review. Changes made, especially in curriculum delivery, led to improved learner focus and more clearly linked theory and practice. The redesigned unit improved performance, measured with the university's student evaluation of feedback instrument (increased from 0.3 to 0.5 points below to 0.1 to 0.5 points above faculty mean in all domains), and was well received by teaching staff. The process confirmed that improved pedagogy can increase student engagement with content and perception of a unit as relevant to future practice.

Identifying effective re-engagement practice : Brisbane North and West Youth Connections Consortium Action Research Project

This report summarises the participatory action research (PAR) undertaken by the Brisbane North and West (BNW) Youth Connections Consortium service during 2010 and 2011. The objective of the service, which is funded by the Australian Government Department of Education, Employment and Workplace Relations (DEEWR), is to re-engage young people who have disengaged from education and are at risk of not achieving Year 12 attainment.The PAR element is facilitated by Queensland University of Technology, School of Public Health and Social Work (QUT). The PAR identifies key elements of the model of service as well as provides summary narratives of the PAR inquiries undertaken by Youth Connections staff and their co-participants during this period.

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.

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.

An action research approach for the professional development of Vietnamese nurse educators

Nurse education in Viet Nam is undergoing substantial reform. In order to facilitate the change, in 2007 the Viet Nam Nurses Association formed a collaborative partnership with the School of Nursing and Midwifery at an Australia university. This collaboration gave rise to the Viet Nam Nursing Capacity Building Project under the leadership of Professor Genevieve Gray, funded by the Atlantic Philanthropies. The new four year competency based nursing curriculum frame is expected to be implemented in September 2011 following approval by the Viet Nam Ministry of Education. The focus of this paper is the Teaching Fellowships Program, an initiative of the Viet Nam Nursing Capacity Building Project, developed to help meet the challenges associated with leading and dealing with the curriculum change. The paper explores the development of the program and justifies an action research approach, illuminates key issues, and briefly refers to changes to the next fellowship program.

Leg Clubs - Beyond the ulcers : case studies based on participatory action research

Based on Participatory Action Research (PAR), the case studies in this paper examine the psychosocial benefits and outcomes for clients of community based Leg Clubs. The Leg Club model was developed in the United Kingdom (UK) to address the issue of social isolation and non-compliance to leg ulcer treatment. Principles underpinning the Leg Club are based on the Participatory Action Framework (PAR) where the input and involvement of participants is central. This study identifies the strengths of the Leg Club in enabling and empowering people to improve the social context in which they function. In addition it highlights the potential of expanding operations that are normally clinically based (particularly in relation to chronic conditions) but transferable to community settings in order that that they become “agents of change” for addressing such issues as social isolation and the accompanying challenges that these present, including no-compliance to treatment.

Improving Indigenous women’s wellness through action research

Today in Australia, 75% of all Indigenous Australians reside in urban and peri-urban areas. In Brisbane, Indigenous Australians now number just over 45,000, and this number is rapidly increasing. Undertaking research with urban based Indigenous Australians is a relatively new phenomenon. Most past research with Indigenous people has been carried out in remote and regional areas. This paper focuses on a Participation Action Research project undertaken with Indigenous women in the highly urbanised area of North Brisbane. The project takes on the challenge of undertaking urban based Indigenous research. It opts not to centre on poor Indigenous women’s health statistics but instead centres on Indigenous women’s wellness and ways to talk about and work towards wellness. Through the cycles of dialogue with Indigenous women these concepts were teased out and manifested in two highly successful Women’s Wellness Summits. This paper will outline aspects of this project.

The effectiveness of a four layer compression bandage system in comparison to Class 3 compression hosiery on healing and quality of life for patients with venous leg ulcers : a randomised controlled trial

There are an increasing number of compression systems available for treatment of venous leg ulcers and limited evidence on the relative effectiveness of these systems. The purpose of this study was to conduct a randomised controlled trial to compare the effectiveness of a 4-layer compression bandage system with Class 3 compression hosiery on healing and quality of life in patients with venous leg ulcers. Data were collected from 103 participants on demographics, health, ulcer status, treatments, pain, depression and quality of life for 24 weeks. After 24 weeks, 86% of the 4-layer bandage group and 77% of the hosiery group were healed (p=0.24). Median time to healing for the bandage group was 10 weeks, in comparison to 14 weeks for the hosiery group (p=0.018). Cox proportional hazards regression found participants in the 4-layer system were 2.1 times (95% CI 1.2–3.5) more likely to heal than those in hosiery, while longer ulcer duration, larger ulcer area and higher depression scores significantly delayed healing. No differences between groups were found in quality of life or pain measures. Findings indicate these systems were equally effective in healing patients by 24 weeks, however a 4-layer system may produce a more rapid response.

Humour and charm in a story of race, headwear and healing

“There are always stories in the wearing” of the iconic beanie just as there are head and heart-warming stories in the making of Alana Valentine’s beautifully crafted Head Full of Love. Nessa and Tilly’s lives entangle at the annual Alice Springs Beanie Festival. The tourist gazes, the craftswoman crochets. Both women have broken pieces of their past that relationship can heal. Collete Mann and Roxanne McDonald capture the rhythm and nuance of difficult relationships perfectly. The humour, pathos and unsentimental depiction of black/white relations in Wesley Enoch’s production promise more than a story, they are a community conversation.

The iatrogenic reflex and belief that repression can coercively suppress asymmetric coercive violence : does very robust action by the government decrease functional support for insurgents?

Non-state insurgent actors are too weak to compel powerful adversaries to their will, so they use violence to coerce. A principal objective is to grow and sustain violent resistance to the point that it either militarily challenges the state, or more commonly, generates unacceptable political costs. To survive, insurgents must shift popular support away from the state and to grow they must secure it. State actor policies and actions perceived as illegitimate and oppressive by the insurgent constituency can generate these shifts. A promising insurgent strategy is to attack states in ways that lead angry publics and leaders to discount the historically established risks and take flawed but popular decisions to use repressive measures. Such decisions may be enabled by a visceral belief in the power of coercion and selective use of examples of where robust measures have indeed suppressed resistance. To avoid such counterproductive behaviours the cases of apparent 'successful repression' must be understood. This thesis tests whether robust state action is correlated with reduced support for insurgents, analyses the causal mechanisms of such shifts and examines whether such reduction is because of compulsion or coercion? The approach is founded on prior research by the RAND Corporation which analysed the 30 insurgencies most recently resolved worldwide to determine factors of counterinsurgent success. This new study first re-analyses their data at a finer resolution with new queries that investigate the relationship between repression and insurgent active support. Having determined that, in general, repression does not correlate with decreased insurgent support, this study then analyses two cases in which the data suggests repression seems likely to be reducing insurgent support: the PKK in Turkey and the insurgency against the Vietnamese-sponsored regime after their ousting of the Khmer Rouge. It applies 'structured-focused' case analysis with questions partly built from the insurgency model of Leites and Wolf, who are associated with the advocacy of US robust means in Vietnam. This is thus a test of 'most difficult' cases using a 'least likely' test model. Nevertheless, the findings refute the deterrence argument of 'iron fist' advocates. Robust approaches may physically prevent effective support of insurgents but they do not coercively deter people from being willing to actively support the insurgency.

Moments of action provide insight into critical times for advection–diffusion–reaction processes

In 2010 Berezhkovskii and coworkers introduced the concept of local accumulation time (LAT) as a finite measure of the time required for the transient solution of a reaction diffusion equation to effectively reach steady state(Biophys J. 99, L59 (2010); Phys Rev E. 83, 051906 (2011)). Berezhkovskii’s approach is a particular application of the concept of mean action time (MAT) that was introduced previously by McNabb (IMA J Appl Math. 47, 193 (1991)). Here, we generalize these previous results by presenting a framework to calculate the MAT, as well as the higher moments, which we call the moments of action. The second moment is the variance of action time; the third moment is related to the skew of action time, and so on. We consider a general transition from some initial condition to an associated steady state for a one–dimensional linear advection–diffusion–reaction partial differential equation(PDE). Our results indicate that it is possible to solve for the moments of action exactly without requiring the transient solution of the PDE. We present specific examples that highlight potential weaknesses of previous studies that have considered the MAT alone without considering higher moments. Finally, we also provide a meaningful interpretation of the moments of action by presenting simulation results from a discrete random walk model together with some analysis of the particle lifetime distribution. This work shows that the moments of action are identical to the moments of the particle lifetime distribution for certain transitions.