499 research outputs found
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Predicting pilot error on the flight deck: Validation of a new methodology and a multiple methods and analysts approach to enhancing error prediction sensitivity
The Human Error Template (HET) is a recently developed methodology for predicting designed induced pilot error. This article describes a validation study undertaken to compare the performance of HET against three contemporary Human Error Identification (HEI) approaches when used to predict pilot errors for an approach and landing task and also to compare individual analyst error predictions to an approach to enhancing error prediction sensitivity: the multiple analysts and methods approach, whereby multiple analyst predictions using a range of HEI technique are pooled. The findings indicate that, of the four methodologies used in isolation, analysts using the HET methodology offered the most accurate error predictions, and also that the multiple analysts and methods approach was more successful overall in terms of error prediction sensitivity than the three other methods but not the HET approach. The results suggest that when predicting design induced error, it is appropriate to use domain specific approaches and also a toolkit of different HEI approaches and multiple analysts in order to heighten error prediction sensitivity
Left hepatic trisegmentectomy
Left hepatic trisegmentectomy was successfully performed upon four patients in whom the true left lobe of the liver and all, or part, of the anterior segment of the right lobe of the liver were removed in continuity. Three of the patients had carcinoma of the liver, and the fourth patient had a hemangioma and arteriovenous malformation. This procedure, which has not been described before, should allow subtotal hepatic resection to be performed upon some patients who have lesions that have been classified as inoperable, in the past
Spatial and temporal variations in plant water-use efficiency inferred from tree-ring, eddy covariance and atmospheric observations
This is the final version of the article. Available from the European Geosciences Union (EGU) via the DOI in this record.Plant water-use efficiency (WUE), which is the ratio of the uptake of carbon dioxide through photosynthesis to the loss of water through transpiration, is a very useful metric of the functioning of the land biosphere. WUE is expected to increase with atmospheric CO2, but to decline with increasing atmospheric evaporative demand – which can arise from increases in near-surface temperature or decreases in relative humidity. We have used Δ13C measurements from tree rings, along with eddy covariance measurements from Fluxnet sites, to estimate the sensitivities of WUE to changes in CO2 and atmospheric humidity deficit. This enables us to reconstruct fractional changes in WUE, based on changes in atmospheric climate and CO2, for the entire period of the instrumental global climate record. We estimate that overall WUE increased from 1900 to 2010 by 48±22%, which is more than double that simulated by the latest Earth System Models. This long-term trend is largely driven by increases in CO2, but significant inter-annual variability and regional differences are evident due to variations in temperature and relative humidity. There are several highly populated regions, such as western Europe and East Asia, where the rate of increase of WUE has declined sharply in the last 2 decades. Our data-based analysis indicates increases in WUE that typically exceed those simulated by Earth System Models-implying that these models are either underestimating increases in photosynthesis or underestimating reductions in transpiration.The contributions of M. Groenendijk, C. Huntingford, and P. M. Cox were funded by the UK Natural Environment Research Council (NERC) HYDRA project. We thank Margaret Barbour for providing tree-ring data compiled from many different sources. This work used eddy covariance data acquired by the FLUXNET community and in particular by the following networks: AmeriFlux (US Department of Energy, Biological and Environmental Research, Terrestrial Carbon Program (DE-FG02-04ER63917 and DE-FG02-04ER63911)), AfriFlux, AsiaFlux, CarboAfrica, CarboEuropeIP, CarboItaly, CarboMont, ChinaFlux, Fluxnet-Canada (supported by CFCAS, NSERC, BIOCAP, Environment Canada, and NRCan), GreenGrass, KoFlux, LBA, NECC, OzFlux, TCOS-Siberia, USCCC. We acknowledge the financial support to the eddy covariance data harmonization provided by CarboEuropeIP, FAO-GTOS-TCO, iLEAPS, Max Planck Institute for Biogeochemistry, National Science Foundation, University of Tuscia, Université Laval and Environment Canada and US Department of Energy and the database development and technical support from Berkeley Water Center, Lawrence Berkeley National Laboratory, Microsoft Research eScience, Oak Ridge National Laboratory, University of California – Berkeley, University of Virginia
Psychometric properties of questionnaires evaluating health-related quality of life and functional status in polytrauma patients with lower extremity injury
BACKGROUND: Long term disability is common among polytrauma patients. However, as yet little information exists on how to adequately measure functional status and health-related quality of life following polytrauma. AIMS: To establish the unidimensionality, internal consistency and validity of two health-related quality of life measures and one functional status questionnaire among polytrauma patients. METHODS: 186 Patients with severe polytrauma including lower extremity injury completed the Sickness Impact Profile-136 (SIP-136), the Medical Outcomes Study 36-Item Short Health Survey (SF-36) and the Groningen Activity Restriction Scale (GARS) 15 months after injury. Unidimensionality and internal consistency was assessed by principal components analysis and Cronbach's alpha (alpha). To test the construct validity of the questionnaires, predetermined hypotheses were tested. RESULTS: The unidimensionality and internal consistency of the GARS and the SF-36, but not the SIP-136 were supported. The construct validity of the SF-36, GARS and to a lesser extent the SIP-136 was confirmed. CONCLUSION: The SF-36 and the GARS appear to be preferable for use in polytrauma patients over the SIP-136
Forefoot disease activity in rheumatoid arthritis patients in remission: results of a cohort study
Women's Experiences Being Diagnosed With Peripartum Cardiomyopathy
Introduction: Cardiovascular disease has been identified as the leading cause of maternal mortality in the United States, with cardiomyopathy, including peripartum cardiomyopathy (PPCM), accounting for 12% to 16% of all pregnancy-related deaths. The purpose of this study was to describe women's experiences being diagnosed with PPCM. Methods: This investigation was conducted using a qualitative design. We collected publicly available narratives posted by 92 women with PPCM (mean [SD] age 29 [6] years, mean [SD] ejection fraction 25.5 [10.8]%) in 3 online support groups. Data were coded and thematically organized so as to produce a richly detailed account of this experience. Results: The experience of diagnosis was marked by the women's distinct memories of their initial symptoms and whether they were dismissed or taken seriously. The most commonly reported symptoms were extreme shortness of breath, orthopnea, tachycardia, palpitations, chest pain, cough, and edema. Nearly 40% of women experienced symptom dismissal by health care providers. One-fourth of women were initially given inaccurate diagnoses ranging from “new mom anxiety” to asthma. Women described their initial reaction to diagnosis as feeling terrified, devastated, and feeling a sense of doom. Women had difficulty caring for their newborns during the postpartum period, and they struggled with the medical advice they received to not get pregnant again. Discussion: Despite experiencing severe subjective and objective symptoms, nearly 40% of women with PPCM experienced symptom dismissal by health care providers, in part due to the overlap between normal symptoms of pregnancy or the postpartum period and symptoms of heart failure
Prevalence and predictors of alcohol use during pregnancy: findings from international multicentre cohort studies
Objectives To compare the prevalence and predictors of alcohol use in multiple cohorts. Design Cross-cohort comparison of retrospective and prospective studies. Setting Population-based studies in Ireland, the UK, Australia and New Zealand. Participants 17 244 women of predominantly Caucasian origin from two Irish retrospective studies (Growing up in Ireland (GUI) and Pregnancy Risk Assessment Monitoring System Ireland (PRAMS Ireland)), and one multicentre prospective international cohort, Screening for Pregnancy Endpoints (SCOPE) study. Primary and secondary outcome measures Prevalence of alcohol use pre-pregnancy and during pregnancy across cohorts. Sociodemographic factors associated with alcohol consumption in each cohort. Results Alcohol consumption during pregnancy in Ireland ranged from 20% in GUI to 80% in SCOPE, and from 40% to 80% in Australia, New Zealand and the UK. Levels of exposure also varied substantially among drinkers in each cohort ranging from 70% consuming more than 1–2 units/week in the first trimester in SCOPE Ireland, to 46% and 15% in the retrospective studies. Smoking during pregnancy was the most consistent predictor of gestational alcohol use in all three cohorts, and smokers were 17% more likely to drink during pregnancy in SCOPE, relative risk (RR)=1.17 (95% CI 1.12 to 1.22), 50% more likely to drink during pregnancy in GUI, RR=1.50 (95% CI 1.36 to 1.65), and 42% more likely to drink in PRAMS, RR=1.42 (95% CI 1.18 to 1.70). Conclusions Our data suggest that alcohol use during pregnancy is prevalent and socially pervasive in the UK, Ireland, New Zealand and Australia. New policy and interventions are required to reduce alcohol prevalence both prior to and during pregnancy. Further research on biological markers and conventions for measuring alcohol use in pregnancy is required to improve the validity and reliability of prevalence estimates
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Interpretation of ambiguous situations: evidence for a dissociation between social and physical threat in Williams syndrome
There is increasing evidence that Williams syndrome (WS) is associated with elevated anxiety that is non-social in nature, including generalised anxiety and fears. To date very little research has examined the cognitive processes associated with this anxiety. In the present research, attentional bias for non-social threatening images in WS was examined using a dot-probe paradigm. Participants were 16 individuals with WS aged between 13 and 34 years and two groups of typically developing controls matched to the WS group on chronological age and attentional control ability respectively. The WS group exhibited a significant attention bias towards threatening images. In contrast, no bias was found for group matched on attentional control and a slight bias away from threat was found in the chronological age matched group. The results are contrasted with recent findings suggesting that individuals with WS do not show an attention bias for threatening faces and discussed in relation to neuroimaging research showing elevated amygdala activation in response to threatening non-social scenes in WS
Multiple Independent Genetic Factors at NOS1AP Modulate the QT Interval in a Multi-Ethnic Population
Extremes of electrocardiographic QT interval are associated with increased risk for sudden cardiac death (SCD); thus, identification and characterization of genetic variants that modulate QT interval may elucidate the underlying etiology of SCD. Previous studies have revealed an association between a common genetic variant in NOS1AP and QT interval in populations of European ancestry, but this finding has not been extended to other ethnic populations. We sought to characterize the effects of NOS1AP genetic variants on QT interval in the multi-ethnic population-based Dallas Heart Study (DHS, n = 3,072). The SNP most strongly associated with QT interval in previous samples of European ancestry, rs16847548, was the most strongly associated in White (P = 0.005) and Black (P = 3.6×10−5) participants, with the same direction of effect in Hispanics (P = 0.17), and further showed a significant SNP × sex-interaction (P = 0.03). A second SNP, rs16856785, uncorrelated with rs16847548, was also associated with QT interval in Blacks (P = 0.01), with qualitatively similar results in Whites and Hispanics. In a previously genotyped cohort of 14,107 White individuals drawn from the combined Atherosclerotic Risk in Communities (ARIC) and Cardiovascular Health Study (CHS) cohorts, we validated both the second locus at rs16856785 (P = 7.63×10−8), as well as the sex-interaction with rs16847548 (P = 8.68×10−6). These data extend the association of genetic variants in NOS1AP with QT interval to a Black population, with similar trends, though not statistically significant at P<0.05, in Hispanics. In addition, we identify a strong sex-interaction and the presence of a second independent site within NOS1AP associated with the QT interval. These results highlight the consistent and complex role of NOS1AP genetic variants in modulating QT interval
Molecular Valves for Controlling Gas Phase Transport Made from Discrete Angstrom-Sized Pores in Graphene
An ability to precisely regulate the quantity and location of molecular flux
is of value in applications such as nanoscale 3D printing, catalysis, and
sensor design. Barrier materials containing pores with molecular dimensions
have previously been used to manipulate molecular compositions in the gas
phase, but have so far been unable to offer controlled gas transport through
individual pores. Here, we show that gas flux through discrete angstrom-sized
pores in monolayer graphene can be detected and then controlled using
nanometer-sized gold clusters, which are formed on the surface of the graphene
and can migrate and partially block a pore. In samples without gold clusters,
we observe stochastic switching of the magnitude of the gas permeance, which we
attribute to molecular rearrangements of the pore. Our molecular valves could
be used, for example, to develop unique approaches to molecular synthesis that
are based on the controllable switching of a molecular gas flux, reminiscent of
ion channels in biological cell membranes and solid state nanopores.Comment: to appear in Nature Nanotechnolog
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