103 research outputs found

    Notched mini round determinate panel test to calculate tensile strength and fracture energy of fibre reinforced cement-stabilised rammed earth

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    The use of natural fibres (like hemp or bamboo) to improve the mechanical performances of rammed earth structures is not new in construction practice in many parts of the world. However, little scientific investigation has been carried out so far to better understand the real improvement obtained by the addition of fibres. In a recent publication [1], the feasibility of notched mini Round Determinate Panels (mRDP) has been investigated with the aim of deriving a procedure to estimate the intrinsic material properties of Fibre Reinforced Shotcrete (FRS). It was found that it was possible to recover the tensile strength and the fracture energy of the material using an inverse analysis of the experimental data and the well-known Olesen constitutive model [2]. In this paper, the use of the notched mini round determinate panel test to characterise the post-cracking performances of Cement Stabilised Rammed Earth (CSRE) was investigated. For quality control issues, in this study the soil mix consisted of crushed limestone stabilised with 8% cement by soil mass and compacted at its optimum water content (11%). Three specimens were made of CSRE alone and three samples were made of fibre-reinforced CSRE. The fibres used in this experimental campaign were unbundled synthetic copolymer fibres, 54 mm long and 0.3 mm thick. This paper discusses the applicability of a laboratory test conceived for concrete samples to rammed earth specimens. It also presents the comparison between the performances of CSRE materials with and without fibres

    Seeking support after hospitalisation for injury: a nested qualitative study of the role of primary care

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    Background In the UK, studies suggest that the transition from hospital to home after an injury can be a difficult time and many patients report feeling inadequately prepared. Patients often use primary care services after hospital discharge. These consultations provide opportunities to consider problems that patients experience and to facilitate recovery. Little is known, however, about how patients and service providers view care after hospital discharge and the role played by primary care services, specifically GPs. Aim To identify good practice and unmet needs in respect of post-discharge support for injured patients. Design and setting Qualitative study using semi-structured interviews at four sites (Bristol, Leicester/ Loughborough, Nottingham, and Surrey). Method Qualitative interviews with 40 service providers and 45 hospitalised injured patients. Results Although there were examples of wellmanaged hospital discharges, many patients felt they were not provided with the information they needed about their injury, what to expect in terms of recovery, pain control, return to work, psychological problems, and services to help meet their needs. They also described difficulty accessing services such as physiotherapy or counselling. Service providers identified problems with communication between secondary and primary care, lack of access to physiotherapy, poor communication about other services that may help patients, GP service and resource constraints, and difficulties in providing information to patients concerning likely prognosis. Conclusion Discharge from hospital after an injury can be problematic for patients. Changes in both secondary and primary care are required to resolve this problem

    Psychological morbidity and health related quality of life after injury: multicentre cohort study

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    Purpose To demonstrate the impact of psychological morbidity 1 month post-injury on subsequent post-injury quality of life (HRQoL) in a general injury population in the UK to inform development of trauma care and rehabilitation services. Methods Multicentre cohort study of 16–70-year-olds admitted to 4 UK hospitals following injury. Psychological morbidity and HRQoL (EQ-5D-3L) were measured at recruitment and 1, 2, 4 and 12 months post-injury. A reduction in EQ-5D compared to retrospectively assessed pre-injury levels of at least 0.074 was taken as the minimal important difference (MID). Multilevel logistic regression explored relationships between psychological morbidity 1 month post-injury and MID in HRQoL over the 12 months after injury. Results A total of 668 adults participated. Follow-up rates were 77% (1 month) and 63% (12 months). Substantial reductions in HRQoL were seen; 93% reported a MID at 1 month and 58% at 12 months. Problems with pain, mobility and usual activities were commonly reported at each time point. Depression and anxiety scores 1 month post-injury were independently associated with subsequent MID in HRQoL. The relationship between depression and HRQoL was partly explained by anxiety and to a lesser extent by pain and social functioning. The relationship between anxiety and HRQoL was not explained by factors measured in our study. Conclusions Hospitalised injuries result in substantial reductions in HRQoL up to 12 months later. Depression and anxiety early in the recovery period are independently associated with lower HRQoL. Identifying and managing these problems, ensuring adequate pain control and facilitating social functioning are key elements in improving HRQoL post-injury

    Seeking support after hospitalisation for injury: a nested qualitative study of the role of primary care

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    Background: In the UK, studies suggest that the transition from hospital to home after an injury can be a difficult time and many patients report feeling inadequately prepared. Patients often use primary care services after hospital discharge. These consultations provide opportunities to consider problems that patients experience and to facilitate recovery. Little is known, however, about how patients and service providers view care after hospital discharge and the role played by primary care services, specifically GPs.Aim: To identify good practice and unmet needs in respect of post-discharge support for injured patients.Design and setting: Qualitative study using semi-structured interviews at four sites (Bristol, Leicester/Loughborough, Nottingham, and Surrey).Method: Qualitative interviews with 40 service providers and 45 hospitalised injured patients.Results: Although there were examples of well-managed hospital discharges, many patients felt they were not provided with the information they needed about their injury, what to expect in terms of recovery, pain control, return to work, psychological problems, and services to help meet their needs. They also described difficulty accessing services such as physiotherapy or counselling. Service providers identified problems with communication between secondary and primary care, lack of access to physiotherapy, poor communication about other services that may help patients, GP service and resource constraints, and difficulties in providing information to patients concerning likely prognosis.Conclusion: Discharge from hospital after an injury can be problematic for patients. Changes in both secondary and primary care are required to resolve this problem

    Psychological morbidity and return to work after injury: multicentre cohort study

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    Background: The benefits of work for physical, psychological and financial wellbeing are well documented. Return to work (RTW) after unintentional injury is often delayed, and psychological morbidity may contribute to this delay. The impact of psychological morbidity on RTW after a wide range of unintentional injuries in the UK has not been adequately quantified. Aims: To quantify the role of psychological factors including anxiety, depression and post-traumatic distress on RTW following unintentional injuries. Design and Setting: Longitudinal multi-centre prospective study in Nottingham, Bristol, Leicester and Guildford, UK Method: Participants (n=273) were 16-69 year olds admitted to hospital following unintentional injury and, in paid employment prior to injury. They were surveyed at baseline, 1, 2, 4 and 12 months following injury on demographic and injury characteristics, psychological morbidity and RTW status. Associations between demographic, injury and psychological factors and RTW status were quantified using random effects logistic regression. Results: The odds of RTW reduced as depression scores one month post-injury increased (OR 0.87, 95%CI 0.79, 0.95) and as length of hospital stay increased (OR 0.91, 95%CI 0.86, 0.96). Those experiencing threatening life events following injury (OR 0.27, 95%CI 0.10, 0.72) and with higher scores on the crisis social support scale (OR 0.93, 95%CI 0.88, 0.99) had a lower odds of RTW. Multiple imputation analysis found similar results except crisis social support did not remain significant. Conclusion: Primary care professionals can identify patients at risk of delayed RTW who may benefit from management of psychological morbidity and support to RTW

    DNA looping provides stability and robustness to the bacteriophage lambda switch

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    The bistable gene regulatory switch controlling the transition from lysogeny to lysis in bacteriophage lambda presents a unique challenge to quantitative modeling. Despite extensive characterization of this regulatory network, the origin of the extreme stability of the lysogenic state remains unclear. We have constructed a stochastic model for this switch. Using Forward Flux Sampling simulations, we show that this model predicts an extremely low rate of spontaneous prophage induction in a recA mutant, in agreement with experimental observations. In our model, the DNA loop formed by octamerization of CI bound to the O_L and O_R operator regions is crucial for stability, allowing the lysogenic state to remain stable even when a large fraction of the total CI is depleted by nonspecific binding to genomic DNA. DNA looping also ensures that the switch is robust to mutations in the order of the O_R binding sites. Our results suggest that DNA looping can provide a mechanism to maintain a stable lysogenic state in the face of a range of challenges including noisy gene expression, nonspecific DNA binding and operator site mutations.Comment: In press on PNAS. Single file contains supplementary inf

    Psychological morbidity and return to work after injury: multicentre cohort study

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    Background: The benefits of work for physical, psychological and financial wellbeing are well documented. Return to work (RTW) after unintentional injury is often delayed, and psychological morbidity may contribute to this delay. The impact of psychological morbidity on RTW after a wide range of unintentional injuries in the UK has not been adequately quantified.Aims: To quantify the role of psychological factors including anxiety, depression and post-traumatic distress on RTW following unintentional injuries.Design and Setting: Longitudinal multi-centre prospective study in Nottingham, Bristol, Leicester and Guildford, UKMethod: Participants (n=273) were 16-69 year olds admitted to hospital following unintentional injury and, in paid employment prior to injury. They were surveyed at baseline, 1, 2, 4 and 12 months following injury on demographic and injury characteristics, psychological morbidity and RTW status. Associations between demographic, injury and psychological factors and RTW status were quantified using random effects logistic regression.Results: The odds of RTW reduced as depression scores one month post-injury increased (OR 0.87, 95%CI 0.79, 0.95) and as length of hospital stay increased (OR 0.91, 95%CI 0.86, 0.96). Those experiencing threatening life events following injury (OR 0.27, 95%CI 0.10, 0.72) and with higher scores on the crisis social support scale (OR 0.93, 95%CI 0.88, 0.99) had a lower odds of RTW. Multiple imputation analysis found similar results except crisis social support did not remain significant.Conclusion: Primary care professionals can identify patients at risk of delayed RTW who may benefit from management of psychological morbidity and support to RTW

    Visual cues given by humans are not sufficient for Asian elephants (Elephas maximus) to find hidden food.

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    Recent research suggests that domesticated species--due to artificial selection by humans for specific, preferred behavioral traits--are better than wild animals at responding to visual cues given by humans about the location of hidden food. \Although this seems to be supported by studies on a range of domesticated (including dogs, goats and horses) and wild (including wolves and chimpanzees) animals, there is also evidence that exposure to humans positively influences the ability of both wild and domesticated animals to follow these same cues. Here, we test the performance of Asian elephants (Elephas maximus) on an object choice task that provides them with visual-only cues given by humans about the location of hidden food. Captive elephants are interesting candidates for investigating how both domestication and human exposure may impact cue-following as they represent a non-domesticated species with almost constant human interaction. As a group, the elephants (n = 7) in our study were unable to follow pointing, body orientation or a combination of both as honest signals of food location. They were, however, able to follow vocal commands with which they were already familiar in a novel context, suggesting the elephants are able to follow cues if they are sufficiently salient. Although the elephants' inability to follow the visual cues provides partial support for the domestication hypothesis, an alternative explanation is that elephants may rely more heavily on other sensory modalities, specifically olfaction and audition. Further research will be needed to rule out this alternative explanation

    Evaluating implementation of a fire-prevention injury prevention briefing in children's centres: cluster randomised controlled trial

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    Background: Many developed countries have high mortality rates for fire-related deaths in children aged 0–14 years with steep social gradients. Evidence-based interventions to promote fire safety practices exist, but the impact of implementing a range of these interventions in children’s services has not been assessed. We developed an Injury Prevention Briefing (IPB), which brought together evidence about effective fire safety interventions and good practice in delivering interventions; plus training and facilitation to support its use and evaluated its implementation. Methods: We conducted a cluster randomised controlled trial, with integrated qualitative and cost-effectiveness nested studies, across four study sites in England involving children’s centres in disadvantaged areas; participants were staff and families attending those centres. Centres were stratified by study site and randomised within strata to one of three arms: IPB plus facilitation (IPB+), IPB only, usual care. IPB+ centres received initial training and facilitation at months 1, 3, and 8. Baseline data from children’s centres were collected between August 2011 and January 2012 and follow-up data were collected between June 2012 and June 2013. Parent baseline data were collected between January 2012 and May 2012 and follow-up data between May 2013 and September 2013. Data comprised baseline and 12 month parent- and staff-completed questionnaires, facilitation contact data, activity logs and staff interviews. The primary outcome was whether families had a plan for escaping from a house fire. Treatment arms were compared using multilevel models to account for clustering by children’s centre. Results: 1112 parents at 36 children’s centres participated. There was no significant effect of the intervention on families’ possession of plans for escaping from a house fire (adjusted odds ratio (AOR) IPB only vs. usual care: 0.93, 95%CI 0.58, 1.49; AOR IPB+ vs. usual care 1.41, 95%CI 0.91, 2.20). However, significantly more families in the intervention arms reported more behaviours for escaping from house fires (AOR IPB only vs. usual care: 2.56, 95%CI 01.38, 4.76; AOR IPB+ vs. usual care 1.78, 95%CI 1.01, 3.15). Conclusion: Our study demonstrated that children’s centres can deliver an injury prevention intervention to families in disadvantaged communities and achieve changes in home safety behaviours
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