144 research outputs found

    Modeling Slope Instability as Shear Rupture Propagation in a Saturated Porous Medium

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    When a region of intense shear in a slope is much thinner than other relevant geometric lengths, this shear failure may be approximated as localized slip, as in faulting, with strength determined by frictional properties of the sediment and effective stress normal to the failure surface. Peak and residual frictional strengths of submarine sediments indicate critical slope angles well above those of most submarine slopes—in contradiction to abundant failures. Because deformation of sediments is governed by effective stress, processes affecting pore pressures are a means of strength reduction. However, common methods of exami ning slope stability neglect dynamically variable pore pressure during failure. We examine elastic-plastic models of the capped Drucker-Prager type and derive approximate equations governing pore pressure about a slip surface when the adjacent material may deform plastically. In the process we identify an elastic-plastic hydraulic diffusivity with an evolving permeability and plastic storage term analogous to the elastic term of traditional poroelasticity. We also examine their application to a dynamically propagating subsurface rupture and find indications of downslope directivity.Earth and Planetary SciencesEngineering and Applied Science

    The impact of clinical placements on the emotional intelligence of occupational therapy, physiotherapy, speech pathology, and business students: a longitudinal study

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    Background: Emotional intelligence (EI) is a critical skill for healthcare practitioners. Minimal longitudinal research has tracked the changes in EI of therapy students over their final full-time clinical placements. Methods: The Emotional Quotient Inventory (EQ-i2.0) measured the EI of 283 therapy students and 93 business students (control group who do no clinical placements) at three time points over a 16-month period, the same period that the therapy students participated in clinical placements. Results: Analysis of the therapy students showed significant increases over the 16 months of the study in Total EI score, as well as nine other EI skills. However, large percentages of students reported declining scores in emotional expression, assertiveness, self-expression, and stress tolerance, with some students reporting low EI scores before commencing full-time extended clinical placements. Conclusions: The study contributes to new knowledge about the changing EI skills of therapy students as they complete their full-time, extended placements. Emotional intelligence in student therapists should be actively fostered during coursework, clinical placements and when first entering the workforce. University educators are encouraged to include EI content through the therapy curricula. Employers are encouraged to provide peer coaching, mentoring and workshops focused on EI skills to recent graduates

    Health-related Quality of Life among hospitalized older people awaiting residential aged care

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    BACKGROUND: Health related quality of life (HRQoL) in very late life is not well understood. The aim of the present study was to assess HRQoL and health outcomes at four months follow-up in a group of older people awaiting transfer to residential aged care. METHODS: Secondary analysis of data from a randomized controlled trial conducted in three public hospitals in Adelaide. A total of 320 patients in hospital beds awaiting a residential aged care bed participated. Outcome measurements included HRQoL (Assessment of Quality of Life; AQoL), functional level (Modified Barthel Index), hospital readmission rates, survival, and place of residence at four months follow-up. RESULTS: In this frail group the median AQoL was poor at baseline (median 0.02; 95%CI -0.01 - 0.04) and at follow-up (0.05; 95%CI 0.03 - 0.06). On leaving hospital, more than one third of participants who were moving for the first time into nursing home care rated themselves in a state worse than death (AQoL < or = 0.0). Poor HRQoL at discharge from hospital (AQoL < or = 0.0) was a significant predictor of mortality (HR 1.7; 95%CI 1.2 - 2.7), but not hospital readmission nor place of residence at four months follow-up. Improved function was a predictor of improved HRQoL among the surviving cohort. CONCLUSION: People making the transition to residential aged care from hospital have very poor HRQoL, but small gains in function seem to be related to improvement. While functional gains are unlikely to change discharge destination in this frail group, they can contribute to improvements in HRQoL. These gains may be of great significance for individuals nearing the end of life and should be taken into account in resource allocation.Lynne C. Giles, Graeme Hawthorne and Maria Crott

    Multi-Informant Predictors of Social Inclusion for Students with Autism Spectrum Disorders Attending Mainstream School

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    This study examined differential profiles of behavioural characteristics predictive of successful inclusion in mainstream education for children with autism spectrum disorders (ASD) and comparison students. Multiple regression analyses using behavioural ratings from parents, teachers and peers found some evidence for differential profiles predicting peer acceptance and rejection. High levels of peer-rated shyness significantly predicted social rejection in comparison students only. Parent-rated prosocial behaviour also differentially predicted social acceptance; high-levels of prosocial behaviour predicted acceptance in comparison students, but low-levels were predictive for students with ASD. These findings suggest that schools may seek to augment traditional social skills programmes with awareness raising about ASD among mainstream pupils to utilise peers’ apparent willingness to discount characteristics such as ‘shyness’

    Predictors of Occurrence and Severity of First Time Low Back Pain Episodes: Findings from a Military Inception Cohort

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    Primary prevention studies suggest that additional research on identifying risk factors predictive of low back pain (LBP) is necessary before additional interventions can be developed. In the current study we assembled a large military cohort that was initially free of LBP and followed over 2 years. The purposes of this study were to identify baseline variables from demographic, socioeconomic, general health, and psychological domains that were predictive of a) occurrence; b) time; and c) severity for first episode of self-reported LBP. Baseline and outcome measures were collected via web-based surveillance system or phone to capture monthly information over 2 years. The assembled cohort consisted of 1230 Soldiers who provided self-report data with 518 (42.1%) reporting at least one episode of LBP over 2 years. Multivariate logistic regression analysis indicated that gender, active duty status, mental and physical health scores were significant predictors of LBP. Cox regression revealed that the time to first episode of LBP was significantly shorter for Soldiers that were female, active duty, reported previous injury, and had increased BMI. Multivariate linear regression analysis investigated severity of the first episode by identifying baseline predictors of pain intensity, disability, and psychological distress. Education level and physical fitness were consistent predictors of pain intensity, while gender, smoking status, and previous injury status were predictors of disability. Gender, smoking status, physical health scores, and beliefs of back pain were consistent predictors of psychological distress. These results provide additional data to confirm the multi-factorial nature of LBP and suggest future preventative interventions focus on multi-modal approaches that target modifiable risk factors specific to the population of interest

    Brief psychosocial education, not core stabilization, reduced incidence of low back pain: results from the Prevention of Low Back Pain in the Military (POLM) cluster randomized trial

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    <p>Abstract</p> <p>Background</p> <p>Effective strategies for the primary prevention of low back pain (LBP) remain elusive with few large-scale clinical trials investigating exercise and education approaches. The purpose of this trial was to determine whether core stabilization alone or in combination with psychosocial education prevented incidence of low back pain in comparison to traditional lumbar exercise.</p> <p>Methods</p> <p>The Prevention of Low Back Pain in the Military study was a cluster randomized clinical study with four intervention arms and a two-year follow-up. Participants were recruited from a military training setting from 2007 to 2008. Soldiers in 20 consecutive companies were considered for eligibility (n = 7,616). Of those, 1,741 were ineligible and 1,550 were eligible but refused participation. For the 4,325 Soldiers enrolled with no previous history of LBP average age was 22.0 years (SD = 4.2) and there were 3,082 males (71.3%). Companies were randomly assigned to receive traditional lumbar exercise, traditional lumbar exercise with psychosocial education, core stabilization exercise, or core stabilization with psychosocial education, The psychosocial education session occurred during one session and the exercise programs were done daily for 5 minutes over 12 weeks. The primary outcome for this trial was incidence of low back pain resulting in the seeking of health care.</p> <p>Results</p> <p>There were no adverse events reported. Evaluable patient analysis (4,147/4,325 provided data) indicated no differences in low back incidence resulting in the seeking of health care between those receiving the traditional exercise and core stabilization exercise programs. However, brief psychosocial education prevented low back pain episodes regardless of the assigned exercise approach, resulting in a 3.3% (95% CI: 1.1 to 5.5%) decrease over two years (numbers needed to treat (NNT) = 30.3, 95% CI = 18.2 to 90.9).</p> <p>Conclusions</p> <p>Core stabilization has been advocated as preventative, but offered no such benefit when compared to traditional lumbar exercise in this trial. Instead, a brief psychosocial education program that reduced fear and threat of low back pain decreased incidence of low back pain resulting in the seeking of health care. Since this trial was conducted in a military setting, future studies are necessary to determine if these findings can be translated into civilian populations.</p> <p>Trial Registration</p> <p><a href="http://www.clinicaltrials.gov/ct2/show/NCT00373009">NCT00373009</a> at ClinicalTrials.gov - <url>http://clinicaltrials.gov/</url></p

    Anthropogenic Disturbance Can Determine the Magnitude of Opportunistic Species Responses on Marine Urban Infrastructures

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    Background: Coastal landscapes are being transformed as a consequence of the increasing demand for infrastructures to sustain residential, commercial and tourist activities. Thus, intertidal and shallow marine habitats are largely being replaced by a variety of artificial substrata (e.g. breakwaters, seawalls, jetties). Understanding the ecological functioning of these artificial habitats is key to planning their design and management, in order to minimise their impacts and to improve their potential to contribute to marine biodiversity and ecosystem functioning. Nonetheless, little effort has been made to assess the role of human disturbances in shaping the structure of assemblages on marine artificial infrastructures. We tested the hypothesis that some negative impacts associated with the expansion of opportunistic and invasive species on urban infrastructures can be related to the severe human disturbances that are typical of these environments, such as those from maintenance and renovation works. Methodology/Principal Findings: Maintenance caused a marked decrease in the cover of dominant space occupiers, such as mussels and oysters, and a significant enhancement of opportunistic and invasive forms, such as biofilm and macroalgae. These effects were particularly pronounced on sheltered substrata compared to exposed substrata. Experimental application of the disturbance in winter reduced the magnitude of the impacts compared to application in spring or summer. We use these results to identify possible management strategies to inform the improvement of the ecological value of artificial marine infrastructures. Conclusions/Significance: We demonstrate that some of the impacts of globally expanding marine urban infrastructures, such as those related to the spread of opportunistic, and invasive species could be mitigated through ecologically-driven planning and management of long-term maintenance of these structures. Impact mitigation is a possible outcome of policies that consider the ecological features of built infrastructures and the fundamental value of controlling biodiversity in marine urban systems

    IL-6 Mediated Degeneration of Forebrain GABAergic Interneurons and Cognitive Impairment in Aged Mice through Activation of Neuronal NADPH Oxidase

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    BACKGROUND:Multiple studies have shown that plasma levels of the pro-inflammatory cytokine interleukin-6 (IL-6) are elevated in patients with important and prevalent adverse health conditions, including atherosclerosis, diabetes, obesity, obstructive sleep apnea, hypertension, and frailty. Higher plasma levels of IL-6, in turn, increase the risk of many conditions associated with aging including age-related cognitive decline. However, the mechanisms underlying this association between IL-6 and cognitive vulnerability remain unclear. METHODS AND FINDINGS:We investigated the role of IL-6 in brain aging in young (4 mo) and aged (24 mo) wild-type C57BL6 and genetically-matched IL-6(-/-) mice, and determined that IL-6 was necessary and sufficient for increased neuronal expression of the superoxide-producing immune enzyme, NADPH-oxidase, and this was mediated by non-canonical NFkappaB signaling. Furthermore, superoxide production by NADPH-oxidase was directly responsible for age-related loss of parvalbumin (PV)-expressing GABAergic interneurons, neurons essential for normal information processing, encoding, and retrieval in hippocampus and cortex. Targeted deletion of IL-6 or elimination of superoxide by chronic treatment with a superoxide-dismutase mimetic prevented age-related loss of PV-interneurons and reversed age-related cognitive deficits on three standard tests of spatial learning and recall. CONCLUSIONS:Present results indicate that IL-6 mediates age-related loss of critical PV-expressing GABAergic interneurons through increased neuronal NADPH-oxidase-derived superoxide production, and that rescue of these interneurons preserves cognitive performance in aging mice, suggesting that elevated peripheral IL-6 levels may be directly and mechanistically linked to long-lasting cognitive deficits in even normal older individuals. Further, because PV-interneurons are also selectively affected by commonly used anesthetic agents and drugs, our findings imply that IL-6 levels may predict adverse CNS effects in older patients exposed to these compounds through specific derangements in inhibitory interneurons, and that therapies directed at lowering IL-6 may have cognitive benefits clinically
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