44 research outputs found

    Pointcatcher software:analysis of glacial time-lapse photography and integration with multi-temporal digital elevation models

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    Terrestrial time-lapse photography offers insight into glacial processes through high spatial and temporal resolution imagery. However, oblique camera views complicate measurement in geographic coordinates, and lead to reliance on specific imaging geometries or simplifying assumptions for calculating parameters such as ice velocity. We develop a novel approach that integrates time-lapse imagery with multi-temporal digital elevation models to derive full 3D coordinates for natural features tracked throughout a monoscopic image sequence. This enables daily independent measurement of horizontal (ice flow) and vertical (ice melt) velocities. By combining two terrestrial laser scanner surveys with a 73-day sequence from SĂłlheimajökull, Iceland, variations in horizontal ice velocity of ~10% were identified over timescales of ~25 days. An overall surface elevation decrease of ~3.0 m showed rate changes asynchronous with the horizontal velocity variations, demonstrating a temporal disconnect between the processes of ice surface lowering and mechanisms of glacier movement. Our software, ‘Pointcatcher’, is freely available for user-friendly interactive processing of general time-lapse sequences and includes Monte Carlo error analysis and uncertainty projection onto DEM surfaces. It is particularly suited for analysis of challenging oblique glacial imagery, and we discuss good features to track, both for correction of camera motion and for deriving ice velocities

    Steady-State Modeling of Condensing Units with an Economizer Loop

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    This paper presents an engineering model that simulates the steady-state operation of air-cooled condensing units. Packaged, air-cooled, condensing units includes a compressor, condensing coil, tubing, and fans, fastened to a base or installed within an enclosure. To increase capacity, modern condensing units are being equipped with a brazed-plate heat exchanger for an economizer loop, configured in either upstream or downstream extraction schemes

    National survey of the injury prevention activities of children's centres

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    Children's centres were established across England to provide a range of services including early education, social care and health to pre-school children and their families. We surveyed children's centres to ascertain the activities they were undertaking to prevent unintentional injuries in the under fives. A postal questionnaire was sent to a sample of children's centre managers (n = 694). It included questions on current activities, knowledge and attitudes to injury prevention, health priorities and partnership working. Responses were received from 384 (56%) children's centres. Overall, 58% considered unintentional injury prevention to be one of the three main child health priorities for their centre. Over half the respondents (59%) did not know if there was an injury prevention group in their area, and 21% did not know if there was a home safety equipment scheme. Knowledge of how child injury deaths occur in the home was poor. Only 11% knew the major cause of injury deaths in children under five. Lack of both staff time and funding were seen as important barriers by children's centre staff to undertake injury prevention activities. Nearly all stated that training (97%) and assistance with planning injury prevention (94%) would be helpful to their centres. Children's centres need further support if they are to effectively tackle this important public health area

    Towards energy resolution at the statistical limit from a negative ion time projection chamber

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    We make a proof-of-principle demonstration that improved energy resolution can be obtained in a negative-ion time projection chamber, by individually counting each electron produced by ionizing radiation.Comment: Submitted to Nucl. Instr. Meth.

    Poison prevention practices and medically attended poisoning in young children: multicentre case-control study

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    Introduction Childhood poisonings are common, placing a substantial burden on health services. Case-control studies have found inconsistent evidence about modifiable risk factors for poisonings amongst 0-4 year olds. This study quantifies associations between poison prevention practices and medically attended poisonings in 0-4 year olds. Methods Multicentre case-control study conducted at hospitals, minor injury units and family practices from four study centres in England between 2010 and 2013. Participants comprised 567 children presenting with unintentional poisoning occurring at home, and 2320 community control participants matched on age, sex, date of event and study centre. Parents/caregivers provided data on safety practices, safety equipment use, home hazards and potential confounders, by means of self-completion questionnaires. Data were analysed using conditional logistic regression. Results Compared with community controls, parents of poisoned children were significantly more likely not to store medicines out of reach (adjusted odds ratio (AOR) 1.59; 95%CI, 1.21, 2.09; population attributable fraction (PAF) 15%), not to store medicines safely (locked or out of reach (AOR 1.83; 95%CI 1.38, 2.42; PAF 16%) and not to have put all medicines (AOR 2.11; 95%CI 1.54, 2.90; PAF 20%) or household products (AOR 1.79, 95%CI 1.29, 2.48; PAF 11%) away immediately after use. Conclusions Not storing medicines out of reach or locked away and not putting medicines and household products away immediately after use increased the odds of secondary care attended poisonings in 0-4 year olds. If associations are causal, implementing these poison prevention practices could each prevent between 11% and 20% of poisonings

    Keeping children safe: a multicentre programme of research to increase the evidence base for preventing unintentional injuries in the home in the under-fives

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    Background: Unintentional injuries among 0- to 4-year-olds are a major public health problem incurring substantial NHS, individual and societal costs. However, evidence on the effectiveness and cost-effectiveness of preventative interventions is lacking. Aim: To increase the evidence base for thermal injury, falls and poisoning prevention for the under-fives. Methods: Six work streams comprising five multicentre case–control studies assessing risk and protective factors, a study measuring quality of life and injury costs, national surveys of children’s centres, interviews with children’s centre staff and parents, a systematic review of barriers to, and facilitators of, prevention and systematic overviews, meta-analyses and decision analyses of home safety interventions. Evidence from these studies informed the design of an injury prevention briefing (IPB) for children’s centres for preventing fire-related injuries and implementation support (training and facilitation). This was evaluated by a three-arm cluster randomised controlled trial comparing IPB and support (IPB+), IPB only (no support) and usual care. The primary outcome was parent-reported possession of a fire escape plan. Evidence from all work streams subsequently informed the design of an IPB for preventing thermal injuries, falls and poisoning. Results: Modifiable risk factors for falls, poisoning and scalds were found. Most injured children and their families incurred small to moderate health-care and non-health-care costs, with a few incurring more substantial costs. Meta-analyses and decision analyses found that home safety interventions increased the use of smoke alarms and stair gates, promoted safe hot tap water temperatures, fire escape planning and storage of medicines and household products, and reduced baby walker use. Generally, more intensive interventions were the most effective, but these were not always the most cost-effective interventions. Children’s centre and parental barriers to, and facilitators of, injury prevention were identified. Children’s centres were interested in preventing injuries, and believed that they could prevent them, but few had an evidence-based strategic approach and they needed support to develop this. The IPB was implemented by children’s centres in both intervention arms, with greater implementation in the IPB+ arm. Compared with usual care, more IPB+ arm families received advice on key safety messages, and more families in each intervention arm attended fire safety sessions. The intervention did not increase the prevalence of fire escape plans [adjusted odds ratio (AOR) IPB only vs. usual care 0.93, 95% confidence interval (CI) 0.58 to 1.49; AOR IPB+ vs. usual care 1.41, 95% CI 0.91 to 2.20] but did increase the proportion of families reporting more fire escape behaviours (AOR IPB only vs. usual care 2.56, 95% CI 1.38 to 4.76; AOR IPB+ vs. usual care 1.78, 95% CI 1.01 to 3.15). IPB-only families were less likely to report match play by children (AOR 0.27, 95% CI 0.08 to 0.94) and reported more bedtime fire safety routines (AOR for a 1-unit increase in the number of routines 1.59, 95% CI 1.09 to 2.31) than usual-care families. The IPB-only intervention was less costly and marginally more effective than usual care. The IPB+ intervention was more costly and marginally more effective than usual care. Limitations: Our case–control studies demonstrate associations between modifiable risk factors and injuries but not causality. Some injury cost estimates are imprecise because of small numbers. Systematic reviews and meta-analyses were limited by the quality of the included studies, the small numbers of studies reporting outcomes and significant heterogeneity, partly explained by differences in interventions. Network meta-analysis (NMA) categorised interventions more finely, but some variation remained. Decision analyses are likely to underestimate cost-effectiveness for a number of reasons. IPB implementation varied between children’s centres. Greater implementation may have resulted in changes in more fire safety behaviours. Conclusions: Our studies provide new evidence about the effectiveness of, as well as economic evaluation of, home safety interventions. Evidence-based resources for preventing thermal injuries, falls and scalds were developed. Providing such resources to children’s centres increases their injury prevention activity and some parental safety behaviours. Future work: Further randomised controlled trials, meta-analyses and NMAs are needed to evaluate the effectiveness and cost-effectiveness of home safety interventions. Further work is required to measure NHS, family and societal costs and utility decrements for childhood home injuries and to evaluate complex multicomponent interventions such as home safety schemes using a single analytical model. Trial registration: Current Controlled Trials ISRCTN65067450 and ClinicalTrials.gov NCT01452191. Funding: The National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 5, No. 14. See the NIHR Journals Library website for further project information

    Preventing childhood scalds within the home: overview of systematic reviews and a systematic review of primary studies

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    Objective: To synthesise and evaluate the evidence of the effectiveness of interventions to prevent scalds in children. Methods: An overview of systematic reviews (SR) and a SR of primary studies were performed evaluating interventions to prevent scalds in children. A comprehensive literature search was conducted covering various resources up to October 2012. Experimental and controlled observational studies reporting scald injuries, safety practices and safety equipment use were included. Results: Fourteen systematic reviews and 39 primary studies were included. There is little evidence that interventions are effective in reducing the incidence of scalds in children. More evidence was found that inventions are effective in promoting safe hot tap water temperature, especially when home safety education, home safety checks and discounted or free safety equipment including thermometers and thermostatic mixing valves were provided. No consistent evidence was found for the effectiveness of interventions on the safe handling of hot food or drinks nor improving kitchen safety practices. Conclusion: Education, home safety checks along with thermometers or thermostatic mixing valves should be promoted to reduce tap water scalds. Further research is needed to evaluate the effectiveness of interventions on scald injuries and to disentangle the effects of multifaceted interventions on scald injuries and safety practices
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