Determination of stress-strain characteristics of railhead steel using image analysis

True stress-strain curve of railhead steel is required to investigate the behaviour of railhead under wheel loading through elasto-plastic Finite Element (FE) analysis. To reduce the rate of wear, the railhead material is hardened through annealing and quenching. The Australian standard rail sections are not fully hardened and hence suffer from non-uniform distribution of the material property; usage of average properties in the FE modelling can potentially induce error in the predicted plastic strains. Coupons obtained at varying depths of the railhead were, therefore, tested under axial tension and the strains were measured using strain gauges as well as an image analysis technique, known as the Particle Image Velocimetry (PIV). The head hardened steel exhibit existence of three distinct zones of yield strength; the yield strength as the ratio of the average yield strength provided in the standard (σyr=780MPa) and the corresponding depth as the ratio of the head hardened zone along the axis of symmetry are as follows: (1.17 σyr, 20%), (1.06 σyr, 20%- 80%) and (0.71 σyr, > 80%). The stress-strain curves exhibit limited plastic zone with fracture occurring at strain less than 0.1.

Educational stress scale for adolescents : development, validity, and reliability with Chinese students

This article describes the development and initial validation of a new instrument to measure academic stress—the Educational Stress Scale for Adolescents (ESSA). A series of cross-sectional questionnaire surveys were conducted with more than 2,000 Chinese adolescents to examine the psychometric properties. The final 16-item ESSA contains five latent variables: Pressure from study, Workload, Worry about grades, Self-expectation, and Despondency, which together explain 64% of the total item variance. Scale scores showed adequate internal consistency, 2-week test–retest reliability, and satisfactory concurrent validity. A confirmatory factor analysis suggested the proposed factor model fits well in a different sample. For researchers who have a particular interest in academic stress among adolescents, the ESSA promises to be a useful tool.

A longitudinal assessment of chronic wound fluid to detect biochemical indicators of healing

Chronic venous leg ulcers are a detrimental health issue plaguing our society, resulting in long term pain, immobility and decreased quality of life for a large proportion of sufferers. The frequency of these chronic wounds has led current research to focus on the wound environment to provide important information regarding the prolonged, fluctuated or static healing patterns of these wounds. Disruption to the normal wound healing process results in release of multiple factors in the wound environment that could correlate to wound chronicity. These biochemical factors can often be detected through non-invasively sampling chronic wound fluid (CWF) from the site of injury. Of note, whilst there are numerous studies comparing acute and chronic wound fluids, there have not been any reports in the literature employing a longitudinal study in order to track biochemical changes in wound fluid as patients transition from a non-healing to healed state. Initially the objective of this study was to identify biochemical changes in CWF associated with wound healing using a proteomic approach. The proteomic approach incorporated a multi-dimensional liquid chromatography fractionation technique coupled with mass spectrometry (MS) to enable identification of proteins present in lower concentrations in CWF. Not surprisingly, many of the proteins identified in wound fluid were acute phase proteins normally expressed during the inflammatory phase of healing. However, the number of proteins positively identified by MS was quite low. This was attributed to the diverse range in concentration of protein species in CWF making it challenging to detect the diagnostically relevant low molecular weight proteins. In view of this, SELDI-TOF MS was also explored as a means to target low molecular weight proteins in sequential patient CWF samples during the course of healing. Unfortunately, the results generated did not yield any peaks of interest that were altered as wounds transitioned to a healed state. During the course of proteomic assessment of CWF, it became evident that a fraction of non-proteinaceous compounds strongly absorbed at 280 nm. Subsequent analyses confirmed that most of these compounds were in fact part of the purine catabolic pathway, possessing distinctive aromatic rings and which results in high absorbance at 254 nm. The accumulation of these purinogenic compounds in CWF suggests that the wound bed is poorly oxygenated resulting in a switch to anaerobic metabolism and consequently ATP breakdown. In addition, the presence of the terminal purine catabolite, uric acid (UA), indicates that the enzyme xanthine oxidoreductase (XOR) catalyses the reaction of hypoxanthine to xanthine and finally to UA. More importantly, the studies provide evidence for the first time of the exogenous presence of XOR in CWF. XOR is the only enzyme in humans capable of catalysing the production of UA in conjunction with a burst of the highly reactive superoxide radical and other oxidants like H2O2. Excessive release of these free radicals in the wound environment can cause cellular damage disrupting the normal wound healing process. In view of this, a sensitive and specific assay was established for monitoring low concentrations of these catabolites in CWF. This procedure involved combining high performance liquid chromatography (HPLC) with tandem mass spectrometry and multiple reaction monitoring (MRM). This application was selective, using specific MRM transitions and HPLC separations for each analyte, making it ideal for the detection and quantitation of purine catabolites in CWF. The results demonstrated that elevated levels of UA were detected in wound fluid obtained from patients with clinically worse ulcers. This suggests that XOR is active in the wound site generating significant amounts of reactive oxygen species (ROS). In addition, analysis of the amount of purine precursors in wound fluid revealed elevated levels of purine precursors in wound fluid from patients with less severe ulcers. Taken together, the results generated in this thesis suggest that monitoring changes of purine catabolites in CWF is likely to provide valuable information regarding the healing patterns of chronic venous leg ulcers. XOR catalysis of purine precursors not only provides a method for monitoring the onset, prognosis and progress of chronic venous leg ulcers, but also provides a potential therapeutic target by inhibiting XOR, thus blocking UA and ROS production. Targeting a combination of these purinogenic compounds and XOR could lead to the development of novel point of care diagnostic tests. Therefore, further investigation of these processes during wound healing will be worthwhile and may assist in elucidating the pathogenesis of this disease state, which in turn may lead to the development of new diagnostics and therapies that target these processes.

Application of Geographic Modeling Techniques to Quantify Spatial Access to Health Services Before and After an Acute Cardiac Event: The Cardiac ARIA Project

Background: Access to cardiac services is essential for appropriate implementation of evidence-based therapies to improve outcomes. The Cardiac Accessibility and Remoteness Index for Australia (Cardiac ARIA) aimed to derive an objective, geographic measure reflecting access to cardiac services. Methods: An expert panel defined an evidence-based clinical pathway. Using Geographic Information Systems (GIS), a numeric/alpha index was developed at two points along the continuum of care. The acute category (numeric) measured the time from the emergency call to arrival at an appropriate medical facility via road ambulance. The aftercare category (alpha) measured access to four basic services (family doctor, pharmacy, cardiac rehabilitation, and pathology services) when a patient returned to their community. Results: The numeric index ranged from 1 (access to principle referral center with cardiac catheterization service ≤ 1 hour) to 8 (no ambulance service, > 3 hours to medical facility, air transport required). The alphabetic index ranged from A (all 4 services available within 1 hour drive-time) to E (no services available within 1 hour). 13.9 million (71%) Australians resided within Cardiac ARIA 1A locations (hospital with cardiac catheterization laboratory and all aftercare within 1 hour). Those outside Cardiac 1A were over-represented by people aged over 65 years (32%) and Indigenous people (60%). Conclusion: The Cardiac ARIA index demonstrated substantial inequity in access to cardiac services in Australia. This methodology can be used to inform cardiology health service planning and the methodology could be applied to other common disease states within other regions of the world.

'Online' geriatric assessment procedure for older adults referred for geriatric assessment during an acute care episode for consideration of reliability of triage decisions

Background Comprehensive geriatric assessment has been shown to improve patient outcomes, but the geriatricians who deliver it are in short-supply. A web-based method of comprehensive geriatric assessment has been developed with the potential to improve access to specialist geriatric expertise. The current study aims to test the reliability and safety of comprehensive geriatric assessment performed “online” in making geriatric triage decisions. It will also explore the accuracy of the procedure in identifying common geriatric syndromes, and its cost relative to conventional “live” consultations. Methods/Design The study population will consist of 270 acutely hospitalized patients referred for geriatric consultation at three sites. Paired assessments (live and online) will be conducted by independent, blinded geriatricians and the level of agreement examined. This will be compared with the level of agreement between two independent, blinded geriatricians each consulting with the patient in person (i.e. “live”). Agreement between the triage decision from live-live assessments and between the triage decision from live-online assessments will be calculated using kappa statistics. Agreement between the online and live detection of common geriatric syndromes will also be assessed using kappa statistics. Resource use data will be collected for online and live-live assessments to allow comparison between the two procedures. Discussion If the online approach is found to be less precise than live assessment, further analysis will seek to identify patient subgroups where disagreement is more likely. This may enable a protocol to be developed that avoids unsafe clinical decisions at a distance. Trial registration Trial registration number: ACTRN12611000936921

Communities Under Stress: Understanding and Managing Growth in Resource–Based Regions–The case of the Western Downs, Queensland

The Western Downs region, located in Southern Queensland, about 200 kilometres west of Brisbane, has been experiencing rapid and significant changes over the past years, due to a massive boom in the energy sector. The rapid growth triggered by the development of mining and energy sectors has generated environmental, socio-economic and land use issues, and has revealed strong weaknesses within the region’s current governance arrangements. The present paper develops a four-stage approach to managing current and expected changes in a resource-based region under tremendous stress and uncertainty.

Two-Photon Fluorescence Microscopy Imaging of Cellular Oxidative Stress Using Profluorescent Nitroxides

A range of varying chromophore nitroxide free radicals and their nonradical methoxyamine analogues were synthesized and their linear photophysical properties examined. The presence of the proximate free radical masks the chromophore’s usual fluorescence emission, and these species are described as profluorescent. Two nitroxides incorporating anthracene and fluorescein chromophores (compounds 7 and 19, respectively) exhibited two-photon absorption (2PA) cross sections of approximately 400 G.M. when excited at wavelengths greater than 800 nm. Both of these profluorescent nitroxides demonstrated low cytotoxicity toward Chinese hamster ovary (CHO) cells. Imaging colocalization experiments with the commercially available CellROX Deep Red oxidative stress monitor demonstrated good cellular uptake of the nitroxide probes. Sensitivity of the nitroxide probes to H2O2-induced damage was also demonstrated by both one- and two-photon fluorescence microscopy. These profluorescent nitroxide probes are potentially powerful tools for imaging oxidative stress in biological systems, and they essentially “light up” in the presence of certain species generated from oxidative stress. The high ratio of the fluorescence quantum yield between the profluorescent nitroxide species and their nonradical adducts provides the sensitivity required for measuring a range of cellular redox environments. Furthermore, their reasonable 2PA cross sections provide for the option of using two-photon fluorescence microscopy, which circumvents commonly encountered disadvantages associated with one-photon imaging such as photobleaching and poor tissue penetration.

Acculturation stress in South Sudanese refugees : impact on marital relationships

A qualitative approach was used to explore the impact of acculturation stress on the marital relationships of South Sudanese refugees settled in Brisbane, Australia. Thirteen refugees, who were currently or previously married, participated in three gender specific focus groups. The perceived causes and possible solutions of conflict were thoroughly explored. Hypothetical scenarios were used to facilitate group discussion. Major issues causing conflict between couples were identified as: the management of finances and lack of family and social support. Several other areas of acculturation stress also emerged as factors associated with marital stress. There was a dissonance regarding the adherence to cultural gender roles. Freedom provided to women in Australia caused tension between the couples. Law enforcement officers were perceived as lacking cultural understanding and misinterpreting the couple distress. Finally, limited information provided to refugees pre and post migration was considered to hinder adjustment. The participants suggested a number of practical solutions to these issues which are potentially useful in guiding future refugee settlement programs.

A research framework for assessing the effects of heat stress on construction workers

Hong Kong in summer (June - October) is hot and humid. Construction workers have to undertake physically demanding activities and often in confined spaces. They are vulnerable to heat stress in summer hence health and safety measures associated to heat stress measured by scientific and clinical parameters are urgently needed. This paper provides an initial report of a research project funded by the Research Grants Council (RGC) of the HKSAR. The aim of this study is to develop a set of indices measured by clinical and scientific methods to detect impending attacks of heat stress. These indices would be of tremendous value in better safeguarding workers’ health and safety by reducing the occurrences of heat stress on site. This paper firstly reports on the statistics of construction incidents arising from heat stress. Qualitative and quantitative research methods applied in conducting the research are discussed. It is believed that the construction industry and the government would benefit a lot as a result of this study.

The lived experience of post-traumatic stress disorder as described by motor vehicle accident victims in Jordan

Aim: To explore the lived experience of post-traumatic stress disorder (PTSD) as described by individuals who have been involved in a motor vehicle accident (MVA) in Jordan. Background: Motor vehicle accident (MVA) survivors who develop post-traumatic stress disorder (PTSD) have become an important health issue. The World Health Organisation (WHO) states that trauma resulting from MVAs is a phenomenon of increasing concern, with death from injuries projected to rise from 5.1 million in 1990 to 8.4 million in 2020 particularly in developing countries such as Jordan (WHO, 2002). The impact of trauma from MVAs inevitably compromises the victim’s quality of life (WHO, 2002; Blanchard & Hickling, 2007) resulting in psychological and emotional distress, occupational disability, family disintegration, and socio-economic difficulty (Jordan Ministry of Health, 2005). The development of PTSD as a result of an MVA is not limited to the individual, but also extends to the family, friends, and the health care team involved in the person's care and rehabilitation. Design: A descriptive phenomenological approach was used for this study. Method: This study was conducted in an orthopaedic unit in Amera Basma Hospital in Irbid Jordan. Fifteen (15) participants were voluntary recruited through the process of purposeful sampling. Data was collected by face-to-face in depth-interviews. Interviews were digitally recorded and transcribed verbatim. The process of analysis was undertaken using Colaizzi’s (1978) eight step approach with the addition of two extra steps. Findings: The process of analysis identified seven themes explicated from the participants’ transcripts of interview. The seven themes were: 1. Feeling frustrated at a diminishing health status 2. Struggling to maintain a sense of independence 3. Harbouring feelings of not being able to recover 4. Feeling discriminated against and marginalised by society 5. Feeling ignored and neglected by health care professionals 6. Feeling abandoned by family, and 7. Moving toward acceptance through having faith in Allah. Conclusion: The findings of this study have the potential to make a significant contribution to extant knowledge on the topic which can inform future nursing practice, education, policy development, and research initiatives in Jordan and internationally.

Patients’ satisfaction with acute care hospital foodservice: does age matter?

In an aging population, healthcare providers should understand the foodservice preferences of the elderly to reduce the risk of malnutrition through adequate nutrition. Conflicting reports exist for elderly patient satisfaction regarding foodservice.1 This study aimed to investigate the relationship between age and foodservice satisfaction within the acute care hospital setting. Patient satisfaction was assessed using the Acute Care Hospital Foodservice Patient Satisfaction Questionnaire with data collected over three years (2008–2010, n = 785) at The Wesley Hospital, Brisbane. Age was grouped into three categories; <50, 51–70 and >70 years. ANOVA was used to measure age related differences in patients’ overall foodservice satisfaction, four foodservice dimensions and two independent statements (meal size and hot food temperature). Results showed that older patients were more satisfied than younger patients and indicated increasing satisfaction with increasing age regarding food quality (F2,767 = 15.787, p < 0.001), staff/service issues (F2,768 = 12.243, p < 0.001), physical environment (F2,765 = 5.454, p = 0.004), meal size (F2,730 = 10.646, p < 0.001) and hot food temperature (F2,730 = 10.646, p < 0.001). While patients aged >70 years also reported greater satisfaction with meal service quality, those aged 51–70 years indicated the lowest (F2,762 = 9.988, p < 0.001). Overall patient satisfaction across all age groups was high (4.26–4.43/5) and a trend of increasing satisfaction with increasing age was evident (F2,752 = 2.900, p = 0.056). These findings suggest patients’ satisfaction with hospital foodservice increases with age and can assist foodservices to meet the varying generational expectations of their clients.

Advanced glycation endproducts in horses with insulin-induced laminitis

Advanced glycation endproducts (AGEs) have been implicated in the pathogenesis of cancer, inflammatory conditions and diabetic complications. An interaction of AGEs with their receptor (RAGE) results in increased release of pro-inflammatory cytokines and reactive oxygen species (ROS), causing damage to susceptible tissues. Laminitis, a debilitating foot condition of horses, occurs in association with endocrine dysfunction and the potential involvement of AGE and RAGE in the pathogenesis of the disease has not been previously investigated. Glucose transport in lamellar tissue is thought to be largely insulin-independent (GLUT-1), which may make the lamellae susceptible to protein glycosylation and oxidative stress during periods of increased glucose metabolism. Archived lamellar tissue from horses with insulin-induced laminitis (n=4), normal control horses (n=4) and horses in the developmental stages (6 h, 12 h and 24 h) of the disease (n=12) was assessed for AGE accumulation and the presence of oxidative protein damage and cellular lipid peroxidation. The equine-specific RAGE gene was identified in lamellar tissue, sequenced and is now available on GenBank. Lamellar glucose transporter (GLUT-1 and GLUT-4) gene expression was assessed quantitatively with qRT-PCR in laminitic and control horses and horses in the mid-developmental time-point (24 h) of the disease. Significant AGE accumulation had occurred by the onset of insulin-induced laminitis (48 h) but not at earlier time-points, or in control horses. Evidence of oxidative stress was not found in any group. The equine-specific RAGE gene was not expressed differently in treated and control animals, nor was the insulin-dependent glucose transporter GLUT-4. However, the glucose transporter GLUT-1 was increased in lamellar tissue in the developmental stages of insulin-induced laminitis compared to control horses and the insulin-independent nature of the lamellae may facilitate AGE formation. However, due to the lack of AGE accumulation during disease development and a failure to detect an increase in ROS or upregulation of RAGE, it appears unlikely that oxidative stress and protein glycosylation play a central role in the pathogenesis of acute, insulin-induced laminitis.

Design and rationale of a Prospective, Observational European Multicenter study on the efficacy of acute surgical decompression after traumatic Spinal Cord Injury: the SCI-POEM study

Objectives:Despite many years of research, there is currently no treatment available that results in major neurological or functional recovery after traumatic spinal cord injury (tSCI). In particular, no conclusive data related to the role of the timing of decompressive surgery, and the impact of injury severity on its benefit, have been published to date. This paper presents a protocol that was designed to examine the hypothesized association between the timing of surgical decompression and the extent of neurological recovery in tSCI patients.Study design: The SCI-POEM study is a Prospective, Observational European Multicenter comparative cohort study. This study compares acute (<12 h) versus non-acute (>12 h, <2 weeks) decompressive surgery in patients with a traumatic spinal column injury and concomitant spinal cord injury. The sample size calculation was based on a representative European patient cohort of 492 tSCI patients. During a 4-year period, 300 patients will need to be enrolled from 10 trauma centers across Europe. The primary endpoint is lower-extremity motor score as assessed according to the 'International standards for neurological classification of SCI' at 12 months after injury. Secondary endpoints include motor, sensory, imaging and functional outcomes at 3, 6 and 12 months after injury.Conclusion:In order to minimize bias and reduce the impact of confounders, special attention is paid to key methodological principles in this study protocol. A significant difference in safety and/or efficacy endpoints will provide meaningful information to clinicians, as this would confirm the hypothesis that rapid referral to and treatment in specialized centers result in important improvements in tSCI patients.Spinal Cord advance online publication, 17 April 2012; doi:10.1038/sc.2012.34.