52 research outputs found
Prestressed fibre reinforced polymer (FRP) laminates for the strengthening of reinforced concrete structures
Recent development in the field of strengthening has seen the application of prestressing of FRP laminate prior to bonding in order to exploit its high tensile strength. The method of prestressing the laminate induces an initial tensile strain in the concrete beams upmost fibre, thus reducing the deflection of the beam throughout the design loads. This alteration of the beams structural characteristics provides advantages in beam serviceability requirements. Structurally the beam can withstand greater ultimate loads, while yielding of internal reinforcement and cracking moments are delayed substantially, compared to unlaminated beams. Extensive experimental investigations have been undertaken by many researchers with variables ranging from anchorage type, number of laminates applied to beam, tensile reinforcement ratio and the initial prestress level of laminates before bonding. Despite the large amount of experimental data in the field, current analytical models generally employ elementary procedures in predicting beam behaviour and as a result the analytical results exhibit poor correlation with the experimental results. This implies the necessity for the development of a generic model that can accurately predict beam behaviour that will be the basis of the present study. The focus of this paper is the development of a new analytical model that can accurately predict the behaviour of an RC beam strengthened with an externally bonded (EB) prestressed fibre reinforced polymer (FRP) laminate. The model will be critically compared to an experimental database for calibration purposes then applied in a parametric study
Differentially loaded radiostereometric analysis (DLRSA) in torsion adds essential information in diaphyseal bone healing: the example of a tibial osteotomy
BACKGROUND: Clinical assessment and conventional imaging, which are currently used to monitor fracture healing, do not provide information on the mechanical properties of the healing construct. This limits their use in patient management decisions. Differentially loaded radiostereometric analysis (DLRSA) is a technique developed to assess the mechanical properties of healing fractures in vivo. DLRSA measures the relative micromotion of tantalum beads inserted into bone fracture fragments in response to load across the fracture site. To date, these loads have been applied axially, although in fractures fixed with devices which are highly resistant to axial loads, such as locked intramedullary nails, torsional testing may be more sensitive to healing. The aim of this study was to establish a method to investigate DLRSA using torsional loading for clinical application. METHODS: A device was designed and built to apply torsional loads to the tibia. The test case was an oblique plain corrective osteotomy of a tibial diaphysis stabilized with an intramedullary nail and with tantalum beads inserted into the two adjacent bone segments. Post surgical examinations were made at 2 weeks, 2, 4, and 6 months as well as 1 and 2 years. Healing was monitored with the use of plain film radiographs, computed tomography (CT) and DLRSA. Axial loads of 30kg and an external torsion of 5Nm were applied during DLRSA examinations and the resultant displacement and stiffness were calculated. RESULTS: Torsional DLRSA demonstrated progressive changes in angular displacements and torsional stiffness consistent with the fracture healing observed by CT. By contrast, axial DLRSA was not informative and was more reflective of the stability of the fixation than healing bone. CONCLUSION: The addition of torsional assessments to DLRSA provides an important investigative option in assessing the biomechanical properties of bone healing in vivo.M.J. Chehade, I.A. Vakaci, S.A. Callary, D.M. Findlay and L.B. Solomo
A Reflection on the State of Sport Coaching Research, Its Community, and Representation: The 2020 International Council for Coaching Excellence Research Committee
This article provides an overview of the context, details, and outcomes of a consultation and review of the International Council for Coaching Excellence’s interactions and engagements with, and service provision to, the international sport coaching research community. The consultation and review were undertaken by the International Council for Coaching Excellence Research Committee (RC). The paper starts with a description of the sport coaching research landscape. It then provides details of the role of the International Council for Coaching Excellence, its Research Fair, and RC. The paper then offers an overview of the formal initiation of the consultation and review at the Global Coach Conference, Japan 2019, as well as a brief overview of the approach used. It then details the consultation findings providing direction for the RC moving forward. The resultant revised RC terms of reference are included as an appendix
A new approach to surgical management of tibial plateau fractures
Tibial plateau fractures (TPFs) are challenging, requiring complex open reduction and internal fixation (ORIF) and are often associated with complications including surgical site infections (SSIs). In 2007, we introduced a novel management protocol to treat TPFs which consisted of an angiosome- or perforator-sparing (APS) anterolateral approach followed by unrestricted weight bearing and range of motion. The primary aim of this retrospective study was to investigate complication rates and patient outcomes associated with our new management protocol. In total, 79 TPFs treated between 2004 and 2007 through a classic anterolateral surgical approach formed the "Classic Group"; while 66 TPFS treated between 2007 and 2013 formed the "APS Group". Fracture reduction, maintenance of reduction and patient-reported outcomes were assessed. There was a clinically important improvement in the infection incidence with the APS (1.5%) versus the Classic technique (7.6%) (1/66 versus 2/79 for superficial infections; 0/66 versus 4/79 for deep infections). Despite a more aggressive rehabilitation, there was no difference in the fracture reduction over time or the functional outcomes between both groups (p > 0.05). The APS anterolateral approach improved the rate of SSIs after TPFs without compromising fracture reduction and stabilisation. We continue to use this new management approach and early unrestricted weight bearing when treating amenable TPFs.Stuart A. Callary, Claire F. Jones, Karim Kantar ... Markus P. Baker, Dominic Thewlis, Gerald J. Atkins ... et al
Practicum for international students in teacher education programs: an investigation of three university sites through multisocialisation, interculturalisation and reflection
This chapter explores the practicum experience of international students undertaking education programs at three different universities in Australia. International students were interviewed about their practicum experiences with a particular focus on what worked well and what needed improvement. Through a thematic analysis as well as identifying aspects of the interview data related to multisocialisation, interculturalisation and reflection models the authors share findings even though international students may experience difficulties during their practicum they also note that these experiences allow them to learn. When mentor teachers were able to recognise the international students’ strengths then placements were successful. Further, unpacking areas that need improvement through a supportive manner enabled students to learn and reconstruct their practice. The rich and informative data on the challenges and successful approaches across the three sites in this study add to the body of literature regarding effective ways to improve work placements for international students
Global Public Health exploring the impact of COVID-19 pandemic lockdown on informal settlements in Tshwane Gauteng Province, South Africa
Informal settlements remain a public health problem as they lack basic infrastructure. Furthermore, it is challenging to enforce public health regulations and protocols to prevent the spread of infection during a pandemic. This paper was set out to explore the impact of lockdown during COVID-19 among people living in informal settlements. An exploratory qualitative design was utilised. Purposive sampling was used to select research participants. In-depth one-to-one interviews were held involving 30 research participants through a WhatsApp online telephone platform. A thematic approach underpinned by the four stages of data analysis in interpretive phenomenological analysis was utilised to analyse the data. The study found that during the the research participants were affected by lack of space to practice social distancing, over-burdened infrastructure, lack of savings, loss of income and shortage of food, hunger and diseases, anxiety and depression and poor access to education. There is a need to prioritise the needs of informal settlers and endeavour to establish permanent homes. Health promotion and communication initiatives and pandemic awareness programmes are needed to mitigate the impact of lockdown during a pandemic in informal settlements
Care of older people and people requiring palliative care with COVID-19: guidance from the Australian National COVID-19 Clinical Evidence Taskforce.
INTRODUCTION: Older people living with frailty and/or cognitive impairment who have coronavirus disease 2019 (COVID-19) experience higher rates of critical illness. There are also people who become critically ill with COVID-19 for whom a decision is made to take a palliative approach to their care. The need for clinical guidance in these two populations resulted in the formation of the Care of Older People and Palliative Care Panel of the National COVID-19 Clinical Evidence Taskforce in June 2020. This specialist panel consists of nursing, medical, pharmacy and allied health experts in geriatrics and palliative care from across Australia. MAIN RECOMMENDATIONS: The panel was tasked with developing two clinical flow charts for the management of people with COVID-19 who are i) older and living with frailty and/or cognitive impairment, and ii) receiving palliative care for COVID-19 or other underlying illnesses. The flow charts focus on goals of care, communication, medication management, escalation of care, active disease-directed care, and managing symptoms such as delirium, anxiety, agitation, breathlessness or cough. The Taskforce also developed living guideline recommendations for the care of adults with COVID-19, including a commentary to discuss special considerations when caring for older people and those requiring palliative care. CHANGES IN MANAGEMENT AS RESULT OF THE GUIDELINE: The practice points in the flow charts emphasise quality clinical care, with a focus on addressing the most important challenges when caring for older individuals and people with COVID-19 requiring palliative care. The adult recommendations contain additional considerations for the care of older people and those requiring palliative care
Wear of highly crosslinked polyethylene acetabular components: a review of RSA studies
Background and purpose - Wear rates of highly crosslinked polyethylene (XLPE) acetabular components have varied considerably between different published studies. This variation is in part due to the different techniques used to measure wear and to the errors inherent in measuring the relatively low amounts of wear in XLPE bearings. We undertook a scoping review of studies that have examined the in vivo wear of XLPE acetabular components using the most sensitive method available, radiostereometric analysis (RSA). Methods - A systematic search of the PubMed, Scopus, and Cochrane databases was performed to identify published studies in which RSA was used to measure wear of XLPE components in primary total hip arthroplasty (THA). Results - 18 publications examined 12 primary THA cohorts, comprising only 260 THAs at 2-10 years of follow-up. The mean or median proximal wear rate reported ranged from 0.00 to 0.06 mm/year. However, differences in the manner in which wear was determined made it difficult to compare some studies. Furthermore, differences in RSA methodology between studies, such as the use of supine or standing radiographs and the use of beaded or unbeaded reference segments, may limit future meta-analyses examining the effect of patient and implant variables on wear rates. Interpretation - This scoping review confirmed the low wear rates of XLPE in THA, as measured by RSA. We make recommendations to enhance the standardization of reporting of RSA wear results, which will facilitate early identification of poorly performing implants and enable a better understanding of the effects of surgical and patient factors on wear.Stuart A Callary, Lucian B Solomon, Oksana T Holubowycz, David G Campbell, Zachary Munn, and Donald W Howi
Parallel-Serial Memoing: A Novel Approach to Analyzing Qualitative Data
The mechanisms by which talking therapies exert their beneficial effects are largely unknown. In exploring the process of a talking therapy, motivational interviewing (MI), when used to treat and prevent low mood in stroke survivors, we developed, what we believe to be, a novel approach to analyzing transcripts. We illustrate the method using qualitative data from MI sessions with 10 stroke survivors. The approach, drawing on grounded theory, incorporated processes of parallel and serial memoing among a team of researchers to allow a process of validation. This enabled us to describe session content and to develop theoretical interpretations of what was occurring in and across MI sessions. We found that this process can be used to integrate different perspectives in theory building, allowing for a richer description and more robust theoretical interpretation. Others can use and adapt this approach to develop insights into their own inquiry
Periprosthetic osteolysis after total hip replacement: molecular pathology and clinical management
Periprosthetic osteolysis is a serious complication of total hip replacement (THR) in the medium to long term. Although often asymptomatic, osteolysis can lead to prosthesis loosening and periprosthetic fracture. These complications cause significant morbidity and require complex revision surgery. Here, we review advances in our understanding of the cell and tissue response to particles produced by wear of the articular and non-articular surfaces of prostheses. We discuss the molecular and cellular regulators of osteoclast formation and bone resorptive activity, a better understanding of which may lead to pharmacological treatments for periprosthetic osteolysis. We describe the development of imaging techniques for the detection and measurement of osteolysis around THR prostheses, which enable improved clinical management of patients, provide a means of evaluating outcomes of non-surgical treatments for periprosthetic osteolysis, and assist in pre-operative planning for revision surgery. Finally, there have been advances in the materials used for bearing surfaces to minimise wear, and we review the literature regarding the performance of these new materials to date.Donald W. Howie, Susan D. Neale, David R. Haynes, Oksana T. Holubowycz, Margaret A. McGee, Lucian B. Solomon, Stuart A. Callary, Gerald J. Atkins, David M. Findla
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