2,905 research outputs found

    Mortality from head injury over four decades in Scotland

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    Although the causes of head injury, the population at risk and approaches to prevention and treatment are continually evolving, there is little information about how these are reflected in patterns of mortality over time. We used population based comprehensive data uniquely available in Scotland to investigate changes in the total numbers of deaths from 1974 to 2012, as well as the rates of head injury death, from different causes, overall and in relation to age and gender. Total mortality fell from an annual average of 503 to 339 with a corresponding annual decrease in rate from 9.6 to 6.4 per 100,000 population, the decline substantially occurring between 1974 and 1990. Deaths in children fell strikingly but rose in older people. Deaths in males fell to a greater extent than females but remained at a higher rate overall. Initially, a transport accident accounted for most deaths but these fell by 80%, from 325 per year to 65 per year over the 39 year period. Deaths from falling and all other causes did not decline, coming to outnumber transport accident deaths by 1998, which accounts for the overall absence of change in total mortality in recent years. In order to reduce mortality in the future, more effective measures to prevent falls are needed and these strategies will vary in younger adults (where alcohol is often a factor), and in older adults where infirmity can be a cause. In addition, measures to sustain reductions in transport accidents need to be maintained and further developed

    Early recurrent ischemic stroke complicating intravenous thrombolysis for stroke: incidence and association with atrial fibrillation

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    <p><b>Background and Purpose:</b> Mechanisms of early neurologic deterioration after treatment with intravenous, recombinant, tissue-type plasminogen activator (IV rt-PA) include symptomatic intracerebral hemorrhage (SICH) and early recurrent ischemic stroke. We observed a number of cases of acute deterioration due to recurrent ischemic events.</p> <p><b>Methods:</b> We undertook a single-center, retrospective analysis of consecutive acute stroke patients treated with IV rt-PA between January 2006 and December 2008 to define the incidence of early neurologic deterioration (>= 4-point drop on the National Institutes of Health Stroke Scale within 72 hours) and its mechanism. Deterioration was attributed to SICH when associated with a PH1 or PH2 hemorrhage on postdeterioration computed tomography scans, to recurrent ischemic stroke when there was clinical and radiologic evidence of a new territorial infarction or new vessel occlusion, and otherwise to evolution of the incident stroke.</p> <p><b>Results:</b> Of 228 consecutive IV rt-PA-treated patients, 34 (15%) developed early neurologic deterioration, 18 (8%) secondary to incident strokes 10 (4.4%) due to SICH, and 6 (2.6%) due to early recurrent ischemic events, which were significantly associated with atrial fibrillation (present in 5 of 6 patients; 4 paroxysmal, 1 permanent). In 4 patients, sudden clinical deterioration developed during or shortly after IV rt-PA infusion, and in 2, deterioration developed 3 days later. All died 2 days to 2 weeks later. The single case without atrial fibrillation had a recurrent, contralateral, middle cerebral artery stroke during IV rt-PA infusion and multiple high-signal emboli detected by transcranial Doppler. Early recurrent ischemic stroke accounted for 5 of 12 (42%) cases of early neurologic deterioration in patients with atrial fibrillation.</p> <p><b>Conclusion:</b> In this single-center series, the incidence of early recurrent ischemic stroke after IV rt-PA was 2.6% and was associated with previous atrial fibrillation.</p&gt

    Blur resolved OCT: full-range interferometric synthetic aperture microscopy through dispersion encoding

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    We present a computational method for full-range interferometric synthetic aperture microscopy (ISAM) under dispersion encoding. With this, one can effectively double the depth range of optical coherence tomography (OCT), whilst dramatically enhancing the spatial resolution away from the focal plane. To this end, we propose a model-based iterative reconstruction (MBIR) method, where ISAM is directly considered in an optimization approach, and we make the discovery that sparsity promoting regularization effectively recovers the full-range signal. Within this work, we adopt an optimal nonuniform discrete fast Fourier transform (NUFFT) implementation of ISAM, which is both fast and numerically stable throughout iterations. We validate our method with several complex samples, scanned with a commercial SD-OCT system with no hardware modification. With this, we both demonstrate full-range ISAM imaging, and significantly outperform combinations of existing methods.Comment: 17 pages, 7 figures. The images have been compressed for arxiv - please follow DOI for full resolutio

    The timing of benthic copepod emergence

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    We investigated emergence of marine benthic harpacticoid and cyclopoid copepods from subtidal sediment into the bottom water. Previous studies that used traps in the field found that copepods emerged from the sediment within 2 h of dusk. We examined emergence in 20-min sampling periods over 13 h from 1200 to 0100 h in a laboratory flume under conditions of constant flow speed. The light intensity was adjusted to field conditions every 20 min. We observed a peak in emergence during the 20-min sampling period after the onset of darkness, greatly increasing the accuracy with which the timing of emergence is known. This result will help to set the stage for studies of emergence cues

    How do you define ‘success?’ Selecting criteria in evaluations of informal science, technology, engineering, and mathematics education

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    Evaluation assesses program merit and worth to deepen understanding and inform decision-making. The assessment is accomplished through the valuing process: the activities of defining success, specifying evaluative criteria, and applying those criteria to reach conclusions. This dissertation examines the substance, source, and application of evaluative criteria—conceptually and empirically—to strengthen the valuing process. The work is grounded in the domain of informal science, technology, engineering, and mathematics (STEM) education evaluation yet is broadly applicable. The first paper advances an empirically-supported model that describes and integrates two aspects of evaluative criteria: substance and source. The second article presents a typology that distinguishes among criteria based on source and application and identifies methods for selecting and applying criteria to represent the values of program participants. The third paper reports a values-inquiry case study that empirically investigates criteria for a public library makerspace and reveals the need for individualized, participant-defined criteria. Collectively, these papers lay the groundwork for building an empirical, descriptive theory of valuing; advancing novel methods for criteria selection; and deepening understanding about criteria selection in evaluation of informal STEM education

    Implementing an analog speedometer in STISIM Drive using Parallax BSTAMP microcontroller

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    In a non-instrumental cab, STISIM Drive software normally projects the speed of the vehicle through a dashboard presented on the simulation screen. The simulated dashboard can be displayed with several graphical options. In all cases, there is a loss of information arising from the road. A solution is to integrate the speedometer into a dashboard and to disable the simulated projection. This solution increases the virtual immersion of the driver and presents speed in a more realistic way. We are proposing a simple solution based on Parallax Inc. Basic Stramp microcontroller. In addition to its low cost and simplicity, this solution allows integration of other technical elements of the driving experience (e.g., activation of turn signals, horn, etc.)

    Deglaciation and neotectonics in South East Raasay, Scottish Inner Hebrides

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    The authors greatly appreciate the help and advice which they have received from: Dr Nicol Morton, who read an early version of the manuscript and provided advice and permission to reproduce the geological map in Figure 3; Dr Iain Stewart for earlier discussions on the geology of Raasay; Dr Alison Macleod for her advice on the magnetic susceptibility of sediments; Dr Adrian Hall, for his advice on the Quaternary geology of the area; Mrs Rebecca Mackay for her advice on the correct Gaelic spelling for place names and Dr Stephan Harrison and Professor Michael Tooley for their help in the field. We are grateful for the comments of the two referees, whose evidently complementary knowledge of the area was most illuminating.Peer reviewedPostprin

    Composition of a chemical signalling trait varies with phylogeny and precipitation across an Australian lizard radiation

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    The environment presents challenges to the transmission and detection of animal signalling systems, resulting in selective pressures that can drive signal divergence amongst populations in disparate environments. For chemical signals, climate is a potentially important selective force because factors such as temperature and moisture influence the persistence and detection of chemicals. We investigated an Australian lizard radiation (Heteronotia) to explore relationships between a sexually dimorphic chemical signalling trait (epidermal pore secretions) and two key climate variables: temperature and precipitation. We reconstructed the phylogeny of Heteronotia with exon capture phylogenomics, estimated phylogenetic signal in amongst-lineage chemical variation and assessed how chemical composition relates to temperature and precipitation using multivariate phylogenetic regressions. High estimates of phylogenetic signal indicate that the composition of epidermal pore secretions varies amongst lineages in a manner consistent with Brownian motion, although there are deviations to this, with stark divergences coinciding with two phylogenetic splits. Accounting for phylogenetic non-independence, we found that amongst-lineage chemical variation is associated with geographic variation in precipitation but not temperature. This contrasts somewhat with previous lizard studies, which have generally found an association between temperature and chemical composition. Our results suggest that geographic variation in precipitation can affect the evolution of chemical signalling traits, possibly influencing patterns of divergence amongst lineages and species

    Lipid Biomarker and Isotopic Study of Community Distribution and Biomarker Preservation in a Laminated Microbial Mat from Shark Bay, Western Australia

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    Modern microbial mats from Shark Bay present some structural similarities with ancient stromatolites; thus, the functionality of microbial communities and processes of diagenetic preservation of modern mats may provide an insight into ancient microbial assemblages and preservation. In this study, the vertical distribution of microbial communities was investigated in a well-laminated smooth mat from Shark Bay. Biolipid and compound-specific isotopic analyses were performed to investigate the distribution of microbial communities in four distinct layers of the mat. Biomarkers indicative of cyanobacteria were more abundant in the uppermost oxic layer. Diatom markers (e.g. C25 HBI alkene, C20:4ω6 and C20:5ω3 polar lipid fatty acids (PLFAs)) were also detected in high abundance in the uppermost layer, but also in the deepest layer under conditions of permanent darkness and anoxia, where they probably used NO3 − for respiration. CycC19:0, an abundant PLFA of purple sulfur bacteria (PSB), was detected in all layers and presented the most 13C-depleted values of all PLFAs, consistent with photoautotrophic PSB. Sulfur-bound aliphatic and aromatic biomarkers were detected in all layers, highlighting the occurrence of early sulfurisation which may be an important mechanism in the sedimentary preservation of functional biolipids in living and, thus, also ancient mats

    Audit of head injury management in Accident and Emergency at two hospitals: implications for NICE CT guidelines

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    BACKGROUND: The National Institute for Clinical Excellence (NICE) has produced guidelines on the early management of head injury. This study audits the process of the management of patients with head injury presenting at Accident and Emergency (A&E) departments and examines the impact upon resources of introducing NICE guidelines for eligibility of a CT scan. METHODS: A retrospective audit of consecutive patients of any age, presenting at A&E with a complaint of head injury during one month in two northern District General Hospitals forming part of a single NHS Trust. RESULTS: 419 patients presented with a median age of 15.5 years, and 61% were male. 58% had a Glasgow Coma Score (GCS) recorded and 33 (8%) were admitted. Only four of the ten indicators for a CT scan were routinely assessed, but data were complete for only one (age), and largely absent for another (vomiting). Using just three (incomplete) indicators showed a likely 4 fold increase in the need for a CT scan. CONCLUSIONS: The majority of patients who present with a head injury to Accident and Emergency departments are discharged home. Current assessment processes and associated data collection routines do not provide the information necessary to implement NICE guidelines for CT brain scans. The development of such clinical audit systems in a busy A&E department is likely to require considerable investment in technology and/or staff. The resource implications for radiology are likely to be substantial
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