1,799 research outputs found

    Accidental child driveway runovers: Exploring Waikato data and the efficacy of existing responses

    Get PDF
    While the numbers of accidents are not high, there is little doubt that driveway runovers are an ongoing, often fatal and inevitably avoidable tragedy for children and their families. In many cases the driver is an immediate family member, or a neighbour or friend, which serves to compound the tragedy. This type of accident is, like other unintentional child injuries, preventable. The over-riding objective of this study is to find ways to minimise the incidence and severity of driveway runovers. We also aim to add Waikato data to the existing knowledge base. This report begins with a description of the research process utilised in this project, which combines a literature review with the collection of Waikato data and a review of available resources. Chapter Two presents the literature review, dividing the material into its different sources, then summarising the literature in terms of the three main factors contributing to driveway runovers. The following chapter provides data on Waikato driveway accidents for the period since May 2006. The type and availability of educational resources is then presented. Chapter Four evaluates existing resources and their availability, suggesting how they might be made more accessible to families. It also assesses existing recommendations and provides further suggestions for enhancing driveway safety. These again reflect the three main categories outlined in the literature – human, vehicle and environmental

    Non-contact measurement of the thickness of a surface film using a superimposed ultrasonic standing wave

    Get PDF
    Most methods used to measure the thickness of thin liquid or solid surface films and coatings need access to the coated surface. In this work reflected ultrasonic pulses were used to measure a coating thickness from a solid back face. Piezoelectric transducers on the solid back face emitted ultrasound waves and received the waves that bounced off the front face. The magnitude of the reflected wave was dependent on the film thickness at the front face. Most pulse-echo ultrasonic approaches use the time-of-flight through the surface layer to determine its thickness. However, as the film becomes thinner, the reflected echoes overlap and there is often an acoustic mismatch between the solid and the surface film that reduces the signal strength. In this work, we propose the use of an ultrasonic continuously repeated chirp longitudinal wave to amplify the effect of the surface film. Multiple reflections interfere within the solid to form a superimposed standing wave whose amplitude spectrum is highly dependent on the surface film thickness thus overcoming the acoustic mismatch problem. Two bare 10 MHz piezoelectric elements were bonded to a 10 mm thick aluminium solid in a pitch-catch arrangement such that one continuously sends repeating chirp ultrasound waves and the other acts as the receiver. The transmitter was set to send a repeating chirp wave of 4 ms duration corresponding to the bandwidth of the transducer in order to maximise signal amplitude. The incident and reflected waves constructively and destructively interfere to form a superimposed standing wave within the solid. The solid/surface film to solid/air boundary condition frequency spectra ratio showed the film resonant frequency modes as minima. Using this technique epoxy coatings ranging from 70 μm to 350 μm were measured and showed a good correlation with independent measurements using a surface profilometer

    A concept analysis of ‘trial recruitment’ using the hybrid model

    Get PDF
    Funding Information: Health Research Board [TMRN-2017-2].Peer reviewedPublisher PD

    High-sensitivity troponin I concentrations are a marker of an advanced hypertrophic response and adverse outcomes in patients with aortic stenosis

    Get PDF
    Aims: High-sensitivity cardiac troponin I (cTnI) assays hold promise in detecting the transition from hypertrophy to heart failure in aortic stenosis. We sought to investigate the mechanism for troponin release in patients with aortic stenosis and whether plasma cTnI concentrations are associated with long-term outcome. Methods and results: Plasma cTnI concentrations were measured in two patient cohorts using a high-sensitivity assay. First, in the Mechanism Cohort, 122 patients with aortic stenosis (median age 71, 67% male, aortic valve area 1.0 ± 0.4 cm2) underwent cardiovascular magnetic resonance and echocardiography to assess left ventricular (LV) myocardial mass, function, and fibrosis. The indexed LV mass and measures of replacement fibrosis (late gadolinium enhancement) were associated with cTnI concentrations independent of age, sex, coronary artery disease, aortic stenosis severity, and diastolic function. In the separate Outcome Cohort, 131 patients originally recruited into the Scottish Aortic Stenosis and Lipid Lowering Trial, Impact of REgression (SALTIRE) study, had long-term follow-up for the occurrence of aortic valve replacement (AVR) and cardiovascular deaths. Over a median follow-up of 10.6 years (1178 patient-years), 24 patients died from a cardiovascular cause and 60 patients had an AVR. Plasma cTnI concentrations were associated with AVR or cardiovascular death HR 1.77 (95% CI, 1.22 to 2.55) independent of age, sex, systolic ejection fraction, and aortic stenosis severity. Conclusions: In patients with aortic stenosis, plasma cTnI concentration is associated with advanced hypertrophy and replacement myocardial fibrosis as well as AVR or cardiovascular death

    PREDATION STRUCTURES COMMUNITIES AT DEEP-SEA HYDROTHERMAL VENTS

    Get PDF
    The structure and dynamics of natural communities result from the interplay of abiotic and biotic factors. We used manipulative field experiments to determine the relative roles of abiotic conditions and biotic interactions in structuring deep-sea (2500 m depth) communities along environmental gradients around hydrothermal vents of the eastern tropical Pacific Ocean (East Pacific Rise, at 9°50' N). We tested (1) whether predation by crabs and fishes affects the recruitment of benthic species and subsequent community structure and (2) whether the effects of predation vary along the steep gradients of temperature, oxygen, sulfide, and metal concentrations near vents. Recruitment substrates (basalt cubic blocks, roughly 10 cm on a side), both uncaged and caged to exclude predators (crabs, fishes, whelks, and octopi), were deployed along a decreasing vent fluid-flux gradient. The exclusion of predators for 8 mo increased the abundance of small mobile gastropods and amphipod crustaceans but decreased the abundance of sessile invertebrates, including juvenile vestimentiferan worms, tubiculous polychaetes, and mussels. Effects of predation were strongest nearest to hydrothermal vents, where abiotic environmental conditions were most extreme but productivity and the overall abundances of benthic invertebrates and mobile predators were the greatest. Additional 5-mo experiments conducted at three different locations showed similar trends at all sites, indicating that these effects of predation on benthic community structure are repeatable. Stomach-content analyses of the most abundant predators found at vents indicated that the zoarcid fish (Thermarces cerberus) primarily feeds on the vent snail Cyathermia naticoides, the limpet Lepetodrilus elevatus, and the amphipod crustacean Ventiella sulfuris, the very species that showed the greatest increase following predator exclusion. In contrast, brachyuran (Bythograea thermydron) and galatheid (Munidopsis subsquamosa) crab stomachs did not contain small mobile grazers, and crabs presented with arrays of the most common vent invertebrate species preferred mussels and vestimentiferans over limpets. Our results indicate that predation by large mobile predators influences the structure of hydrothermal vent communities, directly by reducing the abundance of gastropod prey species, and indirectly by reducing gastropod grazing and by bulldozing of recruits of sessile invertebrates

    The relative contributions of carotid duplex scanning, magnetic resonance angiography, and cerebral arteriography to clinical decisionmaking: A prospective study in patients with carotid occlusive disease

    Get PDF
    AbstractPurpose: Recent reports suggest that 80% to 90% of patients can safely undergo carotid endarterectomy on the basis of duplex scanning alone without cerebral angiography. Other investigators have recommended that a complementary imaging study such as magnetic resonance angiography (MRA) also be obtained.Methods: We prospectively evaluated 103 consecutive patients with carotid occlusive disease. Eighty percent of patients were symptomatic. All 103 patients underwent duplex scanning and arteriography. Additional noninvasive tests included computed tomography, magnetic resonance imaging, and MRA in 50%, 56%, and 48% of patients, respectively. At a multispecialty conference all studies except angiograms were reviewed, and a treatment decision was made by a panel of attending vascular surgeons, neurosurgeons, and neurologists. The cerebral angiograms then were reviewed and changes made to final treatment plans were noted.Results: After review of noninvasive studies, 30 of 103 of patients (29%) were believed to require arteriography because of diagnostic uncertainty of carotid occlusion in three patients, suggestion of nonatherosclerotic disease in four, suggestion of proximal disease in two, suboptimal noninvasive studies in one, and uncertainty of therapy despite good-quality noninvasive studies in 20 patients primarily with borderline stenoses and unclear symptoms. In 10 of these 30 patients (33%) management decisions were changed on the basis of angiogram results. Of the remaining 73 patients (71%) in whom the panel felt comfortable proceeding with operative or medical therapy without angiography, only one patient (1.4%) would have had management altered by results of angiography. MRA results concurred with duplex findings in 92% of studies, but did not alter management in any patient.Conclusions: In patients with good-quality duplex images, focal atherosclerotic bifurcation disease, and clear clinical presentation, treatment decisions can be made without arteriography. In 30% of patients angiography is useful in clarifying decisionmaking. MRA is unlikely to influence management decisions and is thus rarely indicated. (J Vasc Surg 1996;23:950-6.

    Global association of air pollution and heart failure:a systematic review and meta-analysis

    Get PDF
    BACKGROUND: Acute exposure to air pollution has been linked to myocardial infarction, but its effect on heart failure is uncertain. We did a systematic review and meta-analysis to assess the association between air pollution and acute decompensated heart failure including hospitalisation and heart failure mortality. METHODS: Five databases were searched for studies investigating the association between daily increases in gaseous (carbon monoxide, sulphur dioxide, nitrogen dioxide, ozone) and particulate (diameter <2·5 μm [PM(2·5)] or <10 μm [PM(10)]) air pollutants, and heart failure hospitalisations or heart failure mortality. We used a random-effects model to derive overall risk estimates per pollutant. FINDINGS: Of 1146 identified articles, 195 were reviewed in-depth with 35 satisfying inclusion criteria. Heart failure hospitalisation or death was associated with increases in carbon monoxide (3·52% per 1 part per million; 95% CI 2·52–4·54), sulphur dioxide (2·36% per 10 parts per billion; 1·35–3·38), and nitrogen dioxide (1·70% per 10 parts per billion; 1·25–2·16), but not ozone (0·46% per 10 parts per billion; −0·10 to 1·02) concentrations. Increases in particulate matter concentration were associated with heart failure hospitalisation or death (PM(2·5) 2·12% per 10 μg/m(3), 95% CI 1·42–2·82; PM(10) 1·63% per 10 μg/m(3), 95% CI 1·20–2·07). Strongest associations were seen on the day of exposure, with more persistent effects for PM(2·5). In the USA, we estimate that a mean reduction in PM(2·5) of 3·9 μg/m(3) would prevent 7978 heart failure hospitalisations and save a third of a billion US dollars a year. INTERPRETATION: Air pollution has a close temporal association with heart failure hospitalisation and heart failure mortality. Although more studies from developing nations are required, air pollution is a pervasive public health issue with major cardiovascular and health economic consequences, and it should remain a key target for global health policy. FUNDING: British Heart Foundation

    Interventions to improve water supply and quality, sanitation and handwashing facilities in healthcare facilities, and their effect on health care associated infections in low-income and middle-income countries: a systematic review and supplementary scoping review

    Get PDF
    Introduction Healthcare-associated infections (HCAIs) are the most frequent adverse event compromising patient safety globally. Patients in healthcare facilities (HCFs) in low-income and middle-income countries (LMICs) are most at risk. Although water, sanitation and hygiene (WASH) interventions are likely important for the prevention of HCAIs, there have been no systematic reviews to date. Methods As per our prepublished protocol, we systematically searched academic databases, trial registers, WHO databases, grey literature resources and conference abstracts to identify studies assessing the impact of HCF WASH services and practices on HCAIs in LMICs. In parallel, we undertook a supplementary scoping review including less rigorous study designs to develop a conceptual framework for how WASH can impact HCAIs and to identify key literature gaps. Results Only three studies were included in the systematic review. All assessed hygiene interventions and included: a cluster-randomised controlled trial, a cohort study, and a matched case-control study. All reported a reduction in HCAIs, but all were considered at medium high risk of bias. The additional 27 before-after studies included in our scoping review all focused on hygiene interventions, none assessed improvements to water quantity, quality or sanitation facilities. 26 of the studies reported a reduction in at least one HCAI. Our scoping review identified multiple mechanisms by which WASH can influence HCAI and highlighted a number of important research gaps. Conclusions Although there is a dearth of evidence for the effect of WASH in HCFs, the studies of hygiene interventions were consistently protective against HCAIs in LMICs. Additional and higher quality research is urgently needed to fill this gap to understand how WASH service

    Use of Coronary Computed Tomographic Angiography to guide management of patients with coronary disease

    Get PDF
    Background In a prospective, multicenter, randomized controlled trial, 4,146 patients were randomized to receive standard care or standard care plus coronary computed tomography angiography (CCTA). Objectives The purpose of this study was to explore the consequences of CCTA-assisted diagnosis on invasive coronary angiography, preventive treatments, and clinical outcomes. Methods In post hoc analyses, we assessed changes in invasive coronary angiography, preventive treatments, and clinical outcomes using national electronic health records. Results Despite similar overall rates (409 vs. 401; p = 0.451), invasive angiography was less likely to demonstrate normal coronary arteries (20 vs. 56; hazard ratios [HRs]: 0.39 [95% confidence interval (CI): 0.23 to 0.68]; p < 0.001) but more likely to show obstructive coronary artery disease (283 vs. 230; HR: 1.29 [95% CI: 1.08 to 1.55]; p = 0.005) in those allocated to CCTA. More preventive therapies (283 vs. 74; HR: 4.03 [95% CI: 3.12 to 5.20]; p < 0.001) were initiated after CCTA, with each drug commencing at a median of 48 to 52 days after clinic attendance. From the median time for preventive therapy initiation (50 days), fatal and nonfatal myocardial infarction was halved in patients allocated to CCTA compared with those assigned to standard care (17 vs. 34; HR: 0.50 [95% CI: 0.28 to 0.88]; p = 0.020). Cumulative 6-month costs were slightly higher with CCTA: difference 462(95462 (95% CI: 303 to $621). Conclusions In patients with suspected angina due to coronary heart disease, CCTA leads to more appropriate use of invasive angiography and alterations in preventive therapies that were associated with a halving of fatal and non-fatal myocardial infarction. (Scottish COmputed Tomography of the HEART Trial [SCOT-HEART]; NCT01149590
    corecore