226 research outputs found
Impact of Advanced Synoptics and Simplified Checklists During Aircraft Systems Failures
AbstractNatural human capacities are becoming increasingly mismatched to the enormous data volumes, processing capabilities, and decision speeds demanded in todays aviation environment. Increasingly Autonomous Systems (IAS) are uniquely suited to solve this problem. NASA is conducting research and development of IAS - hardware and software systems, utilizing machine learning algorithms, seamlessly integrated with humans whereby task performance of the combined system is significantly greater than the individual components. IAS offer the potential for significantly improved levels of performance and safety that are superior to either human or automation alone. A human-in-the-loop test was conducted in NASA Langleys Integration Flight Deck B-737-800 simulator to evaluate advanced synoptic pages with simplified interactive electronic checklists as an IAS for routine air carrier flight operations and in response to aircraft system failures. Twelve U.S. airline crews flew various normal and non-normal procedures and their actions and performance were recorded in response to failures. These data are fundamental to and critical for the design and development of future increasingly autonomous systems that can better support the human in the cockpit. Synoptic pages and electronic checklists significantly improved pilot responses to non-normal scenarios, but implementation of these aids and other intelligent assistants have barriers to implementation (e.g., certification cost) that must overcome
High-pressure characterization of multifunctional CrVO4
[EN] The structural stability and physical properties of CrVO(4)under compression were studied by x-ray diffraction, Raman spectroscopy, optical absorption, resistivity measurements, andab initiocalculations up to 10 GPa. High-pressure x-ray diffraction and Raman measurements show that CrVO(4)undergoes a phase transition from the ambient pressure orthorhombic CrVO4-type structure (Cmcm space group, phase III) to the high-pressure monoclinic CrVO4-V phase, which is proposed to be isomorphic to the wolframite structure. Such a phase transition (CrVO4-type -> wolframite), driven by pressure, also was previously observed in indium vanadate. The crystal structure of both phases and the pressure dependence in unit-cell parameters, Raman-active modes, resistivity, and electronic band gap, are reported. Vanadium atoms are sixth-fold coordinated in the wolframite phase, which is related to the collapse in the volume at the phase transition. Besides, we also observed drastic changes in the phonon spectrum, a drop of the band-gap, and a sharp decrease of resistivity. All the observed phenomena are explained with the help of first-principles calculations.This work was supported by the Spanish Ministry of Science, Innovation and Universities under Grants MAT2016-75586-C4-1/2-P, FIS2017-83295-P and RED2018-102612-T (MALTA Consolider-Team network) and by Generalitat Valenciana under Grant Prometeo/2018/123 (EFIMAT). PB and AV acknowledge the Kempe Foundation and the Knut och Alice Wallenberg Foundation for their financial support. JAS also acknowledges Ramon y Cajal program for funding support through RYC-2015-17482. The x-ray diffraction measurements were carried out with the support of the Diamond Light Source at the I15 beamline under proposal no. 683. The authors thank A Kleppe for technical support during the experiments. SL-M thanks CONACYT of Mexico for financial support through the program 'Catedras para jovenes Investigadores'. Also, SL-M gratefully acknowledges the computing time granted by LANCAD and CONACYT on the supercomputer Miztli at LSVP DGTIC UNAM. Besides, some of the computing for this project was performed with the resources of the IPICYT Supercomputing National Center for Education & Research, Grant TKII-R2020-SLM1.Botella, P.; López-Moreno, S.; Errandonea, D.; Manjón, F.; Sans-Tresserras, JÁ.; Vie, D.; Vomiero, A. (2020). High-pressure characterization of multifunctional CrVO4. Journal of Physics Condensed Matter. 32(38):1-14. https://doi.org/10.1088/1361-648X/ab9408S114323
Is Optimism Associated With Healthier Cardiovascular-Related Behavior? Meta-Analyses of 3 Health Behaviors
Optimistic people have reduced risk for cardiovascular disease and cardiovascular-related mortality compared with their less optimistic peers. One explanation for this is that optimistic people may be more likely to engage in healthy behavior like exercising frequently, eating fruits and vegetables, and avoiding cigarette smoking. However, researchers have not formally determined the extent or direction of optimism’s association with health behaviors. Moreover, it is unclear whether optimism temporally precedes health behaviors or whether the relationship is because of shared common causes. We conducted random effects meta-analyses examining optimism’s association with 3 health behaviors relevant for the prevention of cardiovascular disease. PubMed and PsycINFO databases were searched for studies published through November 2017 reporting on optimism’s relationship with physical activity, diet, and cigarette smoking. We identified 34 effect sizes for physical activity (n=90 845), 15 effect sizes for diet (n=47 931), and 15 effect sizes for cigarette smoking (n=15 052). Findings suggested that more optimistic individuals tended to engage in healthier behaviors compared with less optimistic individuals, but effect sizes were modest (ractivity=0.07, P\u3c0.0001; rdiet=0.12, P\u3c0.0001; and rsmoking=0.07, P=0.001). Most evidence was cross-sectional (≥53% of effect sizes) and did not consider sociodemographic characteristics (\u3c53% of effect sizes) or psychological distress (\u3c27% of effect sizes) as potential confounders. Optimism is associated with healthier behaviors that protect against cardiovascular disease, although most evidence was relatively low quality. Additional longitudinal and experimental research is required to determine whether optimism causally contributes to healthy behaviors and whether optimism could be an effective target for preventing cardiovascular disease
Large scale synthesis of nanostructured zirconia-based compounds from freeze-dried precursors
Nanocrystalline zirconia powders have been obtained at the multigram scale by thermal decomposition of precursors resulting from the freeze-drying of aqueous acetic solutions. This technique has equally made possible to synthesize a variety of nanostructured yttria or scandia doped zirconia compositions. SEM images, as well as the analysis of the XRD patterns, show the nanoparticulated character of those solids obtained at low temperature, with typical particle size in the 10–15 nm range when prepared at 673 K. The presence of the monoclinic, the tetragonal or both phases depends on the temperature of the thermal treatment, the doping concentration and the nature of the dopant. In addition, Rietveld refinement of the XRD profiles of selected samples allows detecting the coexistence of the tetragonal and the cubic phases for high doping concentration and high thermal treatment temperatures. Raman experiments suggest the presence of both phases also at relatively low treatment temperatures.This study has been supported by the Spanish Ministry of Science and Technology and EU FEDER Program (MAT2009-14144-C03-01, MAT2009-14144-C03-03, MAT2012-38364-C03-01, MAT2012-38364-C03-02). The SCSIE of the Universitat de València is gratefully thanked for the use of the X-ray diffraction, electron microscopy, and analytical facilities. R. Moreno and T. Molina, from Instituto de Cerámica y Vidrio, CSIC, Madrid, are acknowledged by the realization of the agglomerate size measurements
Optimism and Risk of Incident Hypertension: A Target for Primordial Prevention
Aims
Optimism is associated with reduced cardiovascular disease risk; however, few prospective studies have considered optimism in relation to hypertension risk specifically. We investigated whether optimism was associated with a lower risk of developing hypertension in U.S. service members, who are more likely to develop high blood pressure early in life. We also evaluated race/ethnicity, sex and age as potential effect modifiers of these associations.
Methods
Participants were 103 486 hypertension-free U.S. Army active-duty soldiers (mean age 28.96 years, 61.76% White, 20.04% Black, 11.01% Hispanic, 4.09% Asian, and 3.10% others). We assessed optimism, sociodemographic characteristics, health conditions, health behaviours and depression status at baseline (2009–2010) via self-report and administrative records, and ascertained incident hypertension over follow-up (2010–2014) from electronic health records and health assessments. We used Cox proportional hazards regression models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs), and adjusted models for a broad range of relevant covariates.
Results
Over a mean follow-up of 3.51 years, 15 052 incident hypertension cases occurred. The highest v. lowest optimism levels were associated with a 22% reduced risk of developing hypertension, after adjusting for all covariates including baseline blood pressure (HR = 0.78; 95% CI = 0.74–0.83). The difference in hypertension risk between the highest v. lowest optimism was also maintained when we excluded soldiers with hypertension in the first two years of follow-up and, separately, when we excluded soldiers with prehypertension at baseline. A dose–response relationship was evident with higher optimism associated with a lower relative risk (p \u3c 0.001). Higher optimism was consistently associated with a lower risk of developing hypertension across sex, age and most race/ethnicity categories.
Conclusions
In a diverse cohort of initially healthy male and female service members particularly vulnerable to developing hypertension, higher optimism levels were associated with reduced hypertension risk independently of sociodemographic and health factors, a particularly notable finding given the young and healthy population. Results suggest optimism is a health asset and a potential target for public health interventions
Congenital dislocation of the hip: Optimal screening strategies in 2014
AbstractA prospective multi-centre nationwide study of patients with congenital dislocation of the hip (CDH) diagnosed after 3 months of age was conducted with support from the French Society for Paediatric Orthopaedics (Société Française d’Orthopédie Pédiatrique [SoFOP]), French Organisation for Outpatient Paediatrics (Association Française de Pédiatrie Ambulatoire [AFPA]), and French-Speaking Society for Paediatric and Pre-Natal Imaging (Société Francophone d’Imagerie Pédiatrique et Prénatale [SFIPP]). The results showed inadequacies in clinical screening for CDH that were patent when assessed quantitatively and probably also present qualitatively. These findings indicate a need for a communication and educational campaign aimed at highlighting good clinical practice guidelines in the field of CDH screening. The usefulness of routine ultrasound screening has not been established. The findings from this study have been used by the authors and French National Health Authority (Haute Autorité de Santé [HAS]) to develop recommendations about CDH screening. There is an urgent need for a prospective randomised multi-centre nationwide study, which should involve primary-care physicians
Evidence of a causal relationship between body mass index and psoriasis:A mendelian randomization study
Background:
Psoriasis is a common inflammatory skin disease that has been reported to be associated with obesity. We aimed to investigate a possible causal relationship between body mass index (BMI) and psoriasis.
Methods and Findings:
Following a review of published epidemiological evidence of the association between obesity and psoriasis, mendelian randomization (MR) was used to test for a causal relationship with BMI. We used a genetic instrument comprising 97 single-nucleotide polymorphisms (SNPs) associated with BMI as a proxy for BMI (expected to be much less confounded than measured BMI). One-sample MR was conducted using individual-level data (396,495 individuals) from the UK Biobank and the Nord-Trøndelag Health Study (HUNT), Norway. Two-sample MR was performed with summary-level data (356,926 individuals) from published BMI and psoriasis genome-wide association studies (GWASs). The one-sample and two-sample MR estimates were meta-analysed using a fixed-effect model. To test for a potential reverse causal effect, MR analysis with genetic instruments comprising variants from recent genome-wide analyses for psoriasis were used to test whether genetic risk for this skin disease has a causal effect on BMI. Published observational data showed an association of higher BMI with psoriasis. A mean difference in BMI of 1.26 kg/m2 (95% CI 1.02-1.51) between psoriasis cases and controls was observed in adults, while a 1.55 kg/m2 mean difference (95% CI 1.13-1.98) was observed in children. The observational association was confirmed in UK Biobank and HUNT data sets. Overall, a 1 kg/m2 increase in BMI was associated with 4% higher odds of psoriasis (meta-analysis odds ratio [OR] = 1.04; 95% CI 1.03-1.04; P = 1.73 × 10-60). MR analyses provided evidence that higher BMI causally increases the odds of psoriasis (by 9% per 1 unit increase in BMI; OR = 1.09 (1.06-1.12) per 1 kg/m2; P = 4.67 × 10-9). In contrast, MR estimates gave little support to a possible causal effect of psoriasis genetic risk on BMI (0.004 kg/m2 change in BMI per doubling odds of psoriasis (-0.003 to 0.011). Limitations of our study include possible misreporting of psoriasis by patients, as well as potential misdiagnosis by clinicians. In addition, there is also limited ethnic variation in the cohorts studied.
Conclusions:
Our study, using genetic variants as instrumental variables for BMI, provides evidence that higher BMI leads to a higher risk of psoriasis. This supports the prioritization of therapies and lifestyle interventions aimed at controlling weight for the prevention or treatment of this common skin disease. Mechanistic studies are required to improve understanding of this relationship
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