The advancement of technology on the modern commercial flight deck has allowed flight crew members to utilise multiple sources of information to maintain the safety of their flight. Having multiple sources of flight deck information, capable of displaying the same type of information, can lead to a situation in which a pilot encounters conflicting information. Understanding how a pilot makes a decision when faced with an information conflict on the flight deck is important to ensure appropriate design of flight-deck information systems and effective pilot training. This effort utilised data collected from 25 airline pilots who experienced information conflicts on a simulated B-737 flight deck, in conjunction with a theoretical review of how information conflicts impact decision making, to develop a theoretical model of pilot decision-making in the presence of an information conflict. This manuscript describes the model, along with the theory-driven and data-driven approaches utilised to develop the model.

Nebular Heii emission implies the presence of energetic photons (E≽54 eV). Despite the great deal of effort dedicated to understanding Heii ionization, its origin has remained mysterious, particularly in metal-deficient star-forming galaxies. Unfolding Heii-emitting, metal-poor starbursts at z∼0 can yield insight into the powerful ionization processes occurring in the primordial universe. Here we present a study on the origin of the extended nebular Heii emission in SBS 0335-052E, one of the most metal-poor (Z ∼ 3% Z⊙ Heii-emitter starbursts known locally. Based on optical VLT/MUSE spectroscopic and Chandra X-ray observations, and current stellar models we found that the Heii-ionization budget of SBS 0335-052E can only be produced by peculiar, nearly metal-free ionizing stars (called here “PopIII-like” stars) with a top-heavy initial mass function. This result is in line with recent simulations for PopIII star formation down to z=0.

OBJECTIVES/GOALS: Using the covariate-rich Veteran Health Administration data, estimate the association between Proton Pump Inhibitor (PPI) use and severe COVID-19, rigorously adjusting for confounding using propensity score (PS)-weighting. METHODS/STUDY POPULATION: We assembled a national retrospective cohort of United States veterans who tested positive for SARS-CoV-2, with information on 33 covariates including comorbidity diagnoses, lab values, and medications. Current outpatient PPI use was compared to non-use (two or more fills and pills on hand at admission vs no PPI prescription fill in prior year). The primary composite outcome was mechanical ventilation use or death within 60 days; the secondary composite outcome included ICU admission. PS-weighting mimicked a 1:1 matching cohort, allowing inclusion of all patients while achieving good covariate balance. The weighted cohort was analyzed using logistic regression. RESULTS/ANTICIPATED RESULTS: Our analytic cohort included 97,674 veterans with SARS-CoV-2 testing, of whom 14,958 (15.3%) tested positive (6,262 [41.9%] current PPI-users, 8,696 [58.1%] non-users). After weighting, all covariates were well-balanced with standardized mean differences less than a threshold of 0.1. Prior to PS-weighting (no covariate adjustment), we observed higher odds of the primary (9.3% vs 7.5%; OR 1.27, 95% CI 1.13-1.43) and secondary (25.8% vs 21.4%; OR 1.27, 95% CI 1.18-1.37) outcomes among PPI users vs non-users. After PS-weighting, PPI use vs non-use was not associated with the primary (8.2% vs 8.0%; OR 1.03, 95% CI 0.91-1.16) or secondary (23.4% vs 22.9%;OR 1.03, 95% CI 0.95-1.12) outcomes. DISCUSSION/SIGNIFICANCE: The associations between PPI use and severe COVID-19 outcomes that have been previously reported may be due to limitations in the covariates available for adjustment. With respect to COVID-19, our robust PS-weighted analysis provides patients and providers with further evidence for PPI safety.

The first demonstration of laser action in ruby was made in 1960 by T. H. Maiman of Hughes Research Laboratories, USA. Many laboratories worldwide began the search for lasers using different materials, operating at different wavelengths. In the UK, academia, industry and the central laboratories took up the challenge from the earliest days to develop these systems for a broad range of applications. This historical review looks at the contribution the UK has made to the advancement of the technology, the development of systems and components and their exploitation over the last 60 years.

Exposure to childhood maltreatment (CM) may disrupt typical development of neural systems underlying impulse control and emotion regulation. Yet resilient outcomes are observed in some individuals exposed to CM. Individual differences in adult functioning may result from variation in inhibitory control in the context of emotional distractions, underpinned by cognitive–affective brain circuits. Thirty-eight healthy adults with a history of substantiated CM and 34 nonmaltreated adults from the same longitudinal sample performed a Go/No-Go task in which task-relevant stimuli (letters) were presented at the center of task-irrelevant, negative, or neutral images, while undergoing functional magnetic resonance imaging. The comparison group, but not the maltreated group, made increased inhibitory control errors in the context of negative, but not neutral, distractor images. In addition, the comparison group had greater right inferior frontal gyrus and bilateral frontal pole activation during inhibitory control blocks with negative compared to neutral background images relative to the CM group. Across the full sample, greater adaptive functioning in everyday contexts was associated with superior inhibitory control and greater right frontal pole activation. Results suggest that resilience following early adversity is associated with enhanced attention and behavioral regulation in the context of task-irrelevant negative emotional stimuli in a laboratory setting.

The release of buoyant harmful gases within enclosed spaces, such as tunnels and corridors, may engender specific health, industrial and transportation risks. For safety, a simple ventilation strategy for these spaces is to impose a flow along the tunnel, whose velocity is defined as ‘critical’, that confines the front of harmful buoyant gases immediately downstream of the source of emission. Determining the critical velocity as a function of the geometrical and dynamical conditions at the source is a fundamental fluid mechanics problem which has yet to be elucidated; this problem concerns the dynamics of non-Boussinesq releases relating to large differences between the densities of the buoyant and the ambient fluids. We have investigated this problem theoretically, by means of a simplified model of a top-hat plume in a cross-flow, and in complementary experiments by means of tests in a reduced-scale ventilated tunnel, examining releases from circular sources. Experimental results reveal: (i) the existence of two flow regimes depending on the plume Richardson number at the source $\unicode[STIX]{x1D6E4}_{i}$, one for momentum-dominated releases, $\unicode[STIX]{x1D6E4}_{i}\ll 1$, and a second for buoyancy-dominated releases, $\unicode[STIX]{x1D6E4}_{i}\gg 1$, with a smooth transition between the two; and (ii) the presence of relevant non-Boussinesq effects only for momentum-dominated releases. All these features can be conveniently predicted by the plume-based model, whose validity is, strictly speaking, limited to releases issuing from ‘small’ sources in ‘weak’ ventilation flows. Analytical solutions of the model are generally in good agreement with the experimental data, even for values of the governing parameters that are beyond the range of validity for the model. The solutions aid to clarify the effect of the source radius, and reveal interesting behaviours in the limits $\unicode[STIX]{x1D6E4}_{i}\rightarrow 0$ and $\unicode[STIX]{x1D6E4}_{i}\rightarrow \infty$. These findings support the adoption of simplified models to simulate light gas releases in confined ventilated spaces.

Stable perovskite and metastable post-perovskite NaCoF3 were deformed in pure-shear geometry in a deformation-DIA press with radiographic monitoring of the sample strain. In isothermal experiments where there was no transformation, post-perovskite was found to be 5 timesweaker than perovskite. In temperature-ramping experiments where post-perovskite transformed to perovskite during the deformation experiment the initial post-perovskite sample was 5–10 times weaker than perovskite under comparable conditions and their strengths converged during the transformation,being equal on completion of the transformation. These results confirm recent findings which show that postperovskite is weaker than perovskite, regardless of the prior history of the sample.

The thermal diffusivity of diopside, jadeite and enstatite were measured at simultaneous pressures and temperatures of up to 7 GPa and 1200 K using the X-radiographic Ångström method. The measurements herein show that the pressure dependency of thermal diffusivity in pyroxenes is significantly greater than in olivine or garnet and that in the MORB-layer of a subducting slab the thermal diffusivity of pyroxenes are a factor of 1.5 greater than that of olivine. The temperature dependence of all the data sets is well described by a low-order polynomial fit to 1/K and the pressure dependence is exponential in 1/K, formulations which are consistent with the damped harmonic oscillator model for thermal properties.

Aerospace designers are increasingly interested in predicting unsteady flowfields such as those associated with store release, rotating propellers etc. However, the cost of performing fully unsteady calculations is usually prohibitively expensive. In order to address this problem for unsteady flows driven by a moving surface, a novel method is presented which calculates the time derivates as an analytic function of the instantaneous flowfield. This allows an accurate solution of the unsteady flow equations to be calculated using a quasi-unsteady approach. The validity of this approach is demonstrated for a store release and a propeller test case. Possible extensions to this method for more complex unsteady flows are presented.

During 1990 we surveyed the southern sky using a multi-beam receiver at frequencies of 4850 and 843 MHz. The half-power beamwidths were 4 and 25 arcmin respectively. The finished surveys cover the declination range between +10 and −90 degrees declination, essentially complete in right ascension, an area of 7.30 steradians. Preliminary analysis of the 4850 MHz data indicates that we will achieve a five sigma flux density limit of about 30 mJy. We estimate that we will find between 80 000 and 90 000 new sources above this limit. This is a revised version of the paper presented at the Regional Meeting by the first four authors; the surveys now have been completed.

Childhood maltreatment is a serious individual, familial, and societal threat that compromises healthy development and is associated with lasting alterations to emotion perception, processing, and regulation (Cicchetti & Curtis, 2005; Pollak, Cicchetti, Hornung, & Reed, 2000; Pollak & Tolley-Schell, 2003). Individuals with a history of maltreatment show altered structural and functional brain development in both frontal and limbic structures (Hart & Rubia, 2012). In particular, previous research has identified hyperactive amygdala responsivity associated with childhood maltreatment (e.g., Dannlowski et al., 2012). However, less is known about the impact of maltreatment on the relationship between the amygdala and other brain regions. The present study employed an emotion processing functional magnetic resonance imaging task to examine task-based activation and functional connectivity in adults who experienced maltreatment as children. The sample included adults with a history of substantiated childhood maltreatment (n = 33) and comparison adults (n = 38) who were well matched on demographic variables, all of whom have been studied prospectively since childhood. The maltreated group exhibited greater activation than comparison participants in the prefrontal cortex and basal ganglia. In addition, maltreated adults showed increased amygdala connectivity with the hippocampus and prefrontal cortex. The results suggest that the intense early stress of childhood maltreatment is associated with lasting alterations to frontolimbic circuitry.

Gamma-ray burst host galaxies are deficient in molecular gas, and show anomalous metal-poor regions close to GRB positions. Using recent Australia Telescope Compact Array (ATCA) Hi observations we show that they have substantial atomic gas reservoirs. This suggests that star formation in these galaxies may be fuelled by recent inflow of metal-poor atomic gas. While this process is debated, it can happen in low-metallicity gas near the onset of star formation because gas cooling (necessary for star formation) is faster than the Hi-to-H2 conversion.