2,212 research outputs found

    Disability in young people and adults one year after head injury: prospective cohort study

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    OBJECTIVE: To determine the frequency of disability in young people and adults admitted to hospital with a head injury and to estimate the annual incidence in the community. DESIGN: Prospective, hospital based cohort study, with one year follow up of sample stratified by coma score. SETTING: Five acute hospitals in Glasgow. SUBJECTS: 2962 patients (aged 14 years or more) with head injury; 549 (71%) of the 769 patients selected for follow up participated. MAIN OUTCOME MEASURES: Glasgow outcome scale and problem orientated questionnaire. RESULTS: Survival with moderate or severe disability was common after mild head injury (47%, 95% confidence interval 42% to 52%) and similar to that after moderate (45%, 35% to 56%) or severe injury (48%, 36% to 60%). By extrapolation from the population identified (90% of whom had mild injuries), it was estimated that annually in Glasgow (population 909 498) 1400 young people and adults are still disabled one year after head injury. CONCLUSION: The incidence of disability in young people and adults admitted with a head injury is higher than expected. This reflects the high rate of sequelae previously unrecognised in the large number of patients admitted to hospital with an apparently mild head injury

    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

    The Avalon Historic Petroglyphs Project: Investigating Historic Graffiti and Petroglyphs on Newfoundland’s Eastern Avalon Peninsula

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    Newfoundland’s Avalon Peninsula contains many examples of petroglyphs, historic graffiti and inscriptions/engravings dating from the 17th to 20th centuries. This paper highlights the sites of Kingman’s Cove (CfAf-25) and Brigus South (CgAf-21), the computational photography and conservation techniques used in their recording, and current interpretations on who made them, why, when, and what they represent. The results show the broad potential of historic inscriptions for understanding the movements of people who are often poorly represented in the documentary record, the importance of peripheral landscapes and features as foci for self-expression, place-making and remembrance, and the need for innovative methodologies to record these ephemeral and endangered features. Furthermore, these sites are often of continued relevance to local communities (whose intimate landscape knowledge is typically required for their study) while also bearing a contemporary legacy as seen in nearby similar spatially-focused areas of modern graffiti

    Calcium channel blockers for acute traumatic brain injury.

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    BACKGROUND: Acute traumatic brain injury is a major cause of death and disability. Calcium channel blockers (calcium antagonists) have been used in an attempt to prevent cerebral vasospasm after injury, maintain blood flow to the brain, and so prevent further damage. OBJECTIVES: To estimate the effects of calcium channel blockers in patients with acute traumatic brain injury, and in a subgroup of brain injury patients with traumatic subarachnoid haemorrhage. SEARCH STRATEGY: Handsearching and electronic searching for randomised controlled trials. SELECTION CRITERIA: Randomised controlled trials in patients with all levels of severity of clinically diagnosed acute traumatic brain injury. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed the identified studies for eligibility and extracted data from each study. Summary odds ratios were calculated using the Mantel-Haenszel method. MAIN RESULTS: Six RCTs were identified as eligible for inclusion in the systematic review. The effect of calcium channel blockers on the risk of death was reported in five of the RCTs. The pooled odds ratio (OR) for the five studies was 0.91 (95% confidence interval [95%CI] 0.70-1.17). For the four RCTs that reported death and severe disability (unfavourable outcome), the pooled odds ratio was 0.85 (95%CI 0.68-1.07). In the two RCTs which reported the risk of death in a subgroup of traumatic subarachnoid haemorrhage patients, the pooled odds ratio was 0.59 (95%CI 0.37-0.94). Three RCTs reported death and severe disability as an outcome in this subgroup, and the pooled odds ratio was 0.67 (95%CI 0.46-0.98). REVIEWER'S CONCLUSIONS: This systematic review of randomised controlled trials of calcium channel blockers in acute traumatic head injury patients shows that considerable uncertainty remains over their effects. The effect of nimodipine in a subgroup of brain injury patients with subarachnoid haemorrhage shows a beneficial effect, though the increase in adverse reactions suffered by the intervention group may mean that the drug is harmful for some patients

    The effect of diameter variability and medullation of wool on Fibre Fineness Distribution Analyser (FFDA) measurements.

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    No presente trabalho foram investigados os efeitos da medulação e da variabilidade de diâmetro da lã sobre as medidas de diâmetro no FFDA. Foram desenvolvidas equações para corrigir os resultados oriundos do FFDA, de acordo com o grau de medulação das amostras. Os resultados do trabalho indicaram que na calibração do FFDA deveria ser incluído um "top" de lã com maior diâmetro médio do que os usados correntemente. Isto melhoraria os resultados para as lãs mais grossas.The effect of medullation and variability of fibre diameter on FFDA measurements were investigated. For a FFDA fitted with the expanding (new) cell, medullated wools and more variable wools gave finer results than those obtained with the projection microscope. Equations correcting FFDA results for the degree of medullation are presented. It is suggested that calibration using a coarser top than those currently in use would improve measurements on coarse wool

    Secondary Metabolites Produced by the Marine Bacterium Halobacillus salinus That Inhibit Quorum Sensing-Controlled Phenotypes in Gram-Negative Bacteria

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    Certain bacteria use cell-to-cell chemical communication to coordinate community-wide phenotypic expression, including swarming motility, antibiotic biosynthesis, and biofilm production. Here we present a marine gram-positive bacterium that secretes secondary metabolites capable of quenching quorum sensing-controlled behaviors in several gram-negative reporter strains. Isolate C42, a Halobacillus salinus strain obtained from a sea grass sample, inhibits bioluminescence production by Vibrio harveyi in cocultivation experiments. With the use of bioassay-guided fractionation, two phenethylamide metabolites were identified as the active agents. The compounds additionally inhibit quorum sensing-regulated violacein biosynthesis by Chromobacterium violaceum CV026 and green fluorescent protein production by Escherichia coli JB525. Bacterial growth was unaffected at concentrations below 200 μg/ml. Evidence is presented that these nontoxic metabolites may act as antagonists of bacterial quorum sensing by competing with N-acyl homoserine lactones for receptor binding

    SopB-Mediated Recruitment of SNX18 Facilitates Salmonella Typhimurium Internalization by the Host Cell

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    To invade epithelial cells, Salmonella enterica serovar Typhimurium (S. Typhimurium) induces macropinocytosis through the action of virulence proteins delivered across the host cell membrane via a type III secretion system. We show that after docking at the plasma membrane S. Typhimurium triggers rapid recruitment of cytosolic SNX18, a SH3-PX-BAR domain sorting nexin protein, to the bacteria-induced membrane ruffles and to the nascent Salmonella-containing vacuole. SNX18 recruitment required the inositol-phosphatase activity of the Salmonella effector SopB and an intact phosphoinositide-binding site within the PX domain of SNX18, but occurred independently of Rho-GTPases Rac1 and Cdc42 activation. SNX18 promotes formation of the SCV from the plasma membrane by acting as a scaffold to recruit Dynamin-2 and N-WASP in a process dependent on the SH3 domain of SNX18. Quantification of bacteria uptake revealed that overexpression of SNX18 increased bacteria internalization, whereas a decrease was detected in cells overexpressing the phosphoinositide-binding mutant R303Q, the ΔSH3 mutant, and in cells where endogenous levels of SNX18 were knocked-down. This study identifies SNX18 as a novel target of SopB and suggests a mechanism where S. Typhimurium engages host factors via local manipulation of phosphoinositide composition at the site of invasion to orchestrate the internalization process

    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

    A New Solid Deuterium Source of Ultra-Cold Neutrons

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    In polarized neutron decay, the angular correlation between the neutron spin and the direction of emission of the electron is characterized by the coefficient A. Measuring A involves determining the forward-backward asymmetry of the decay beta with respect to the direction of the neutron polarization. The value of A, when combined with measurements of the neutron lifetime, determines the values of the vector and axial vector weak coupling constants, Gv and GA. The value of Gv can also be determined by measurements of superallowed nuclear beta decay and by requiring that the Cabibo-Kobayashi-Maskawi (CKM) mixing matrix be unitary along with the measured value of other elements of the CKM matrix
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