108 research outputs found

    Simulation‐based otorhinolaryngology emergencies boot camp: Part 1: Curriculum design and airway skills

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/107579/1/lary24572.pd

    Simulation‐based otorhinolaryngology emergencies boot camp: Part 2: Special skills using task trainers

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/107500/1/lary24571.pd

    Spinodal Decomposition in a Binary Polymer Mixture: Dynamic Self Consistent Field Theory and Monte Carlo Simulations

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    We investigate how the dynamics of a single chain influences the kinetics of early stage phase separation in a symmetric binary polymer mixture. We consider quenches from the disordered phase into the region of spinodal instability. On a mean field level we approach this problem with two methods: a dynamical extension of the self consistent field theory for Gaussian chains, with the density variables evolving in time, and the method of the external potential dynamics where the effective external fields are propagated in time. Different wave vector dependencies of the kinetic coefficient are taken into account. These early stages of spinodal decomposition are also studied through Monte Carlo simulations employing the bond fluctuation model that maps the chains -- in our case with 64 effective segments -- on a coarse grained lattice. The results obtained through self consistent field calculations and Monte Carlo simulations can be compared because the time, length, and temperature scales are mapped onto each other through the diffusion constant, the chain extension, and the energy of mixing. The quantitative comparison of the relaxation rate of the global structure factor shows that a kinetic coefficient according to the Rouse model gives a much better agreement than a local, i.e. wave vector independent, kinetic factor. Including fluctuations in the self consistent field calculations leads to a shorter time span of spinodal behaviour and a reduction of the relaxation rate for smaller wave vectors and prevents the relaxation rate from becoming negative for larger values of the wave vector. This is also in agreement with the simulation results.Comment: Phys.Rev.E in prin

    Bridge to the stars: A mission concept to an interstellar object

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    Exoplanet discoveries since the mid-1990’s have revealed an astounding diversity of planetary systems. Studying these systems is essential to understanding planetary formation processes, as well as the development of life in the universe. Unfortunately, humanity can only observe limited aspects of exoplanetary systems by telescope, and the significant distances between stars presents a barrier to in situ exploration. In this study, we propose an alternative path to gain insight into exoplanetary systems: Bridge, a mission concept design to fly by an interstellar object as it passes through our solar system. Designed as a New Frontiers-class mission during the National Aeronautics and Space Administration (NASA) Planetary Science Summer School, Bridge would provide a unique opportunity to gain insight into potential physical, chemical, and biological differences between solar systems as well as the possible exchange of planetary materials between them. Bridge employs ultraviolet/visible, near-infrared, and mid-infrared point spectrometers, a visible camera, and a guided impactor. We also provide a quantitative Monte Carlo analysis that estimates wait times for a suitable target, and examines key trades between ground storage and a parking orbit, power sources, inner versus outer solar system encounters, and launch criteria. Due to the fleeting nature of interstellar objects, reaching an interstellar object may require an extended ground storage phase for the spacecraft until a suitable ISO is discovered, followed by a rapid response launch strategy. To enable rapid response missions designed to intercept such unique targets, language would need to be added to future NASA announcements of opportunity such that ground storage and rapid response would be allowable components of a proposed mission

    Elections and Ethnic Civil War

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    Existing research on how democratization may influence the risk of civil war tends to consider only changes in the overall level of democracy and rarely examines explicitly the postulated mechanisms relating democratization to incentives for violence. The authors argue that typically highlighted key mechanisms imply that elections should be especially likely to affect ethnic groups’ inclination to resort to violence. Distinguishing between types of conflict and the order of competitive elections, the authors find that ethnic civil wars are more likely to erupt after competitive elections, especially after first and second elections following periods of no polling. When disaggregating to the level of individual ethnic groups and conflicts over territory or government, the authors find some support for the notion that ethno-nationalist mobilization and sore-loser effects provoke postelectoral violence. More specifically, although large groups in general are more likely to engage in governmental conflicts, they are especially likely to do so after noncompetitive elections. Competitive elections, however, strongly reduce the risk of conflict. </jats:p

    Prevalence of Errors in Anaphylaxis in Kids (PEAK): A Multicenter Simulation-Based Study

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    Background Multi-institutional, international practice variation of pediatric anaphylaxis management by health care providers has not been reported. Objective To characterize variability in epinephrine administration for pediatric anaphylaxis across institutions, including frequency and types of medication errors. Methods A prospective, observational, study using a standardized in situ simulated anaphylaxis scenario was performed across 28 health care institutions in 6 countries. The on-duty health care team was called for a child (patient simulator) in anaphylaxis. Real medications and supplies were obtained from their actual locations. Demographic data about team members, institutional protocols for anaphylaxis, timing of epinephrine delivery, medication errors, and systems safety issues discovered during the simulation were collected. Results Thirty-seven in situ simulations were performed. Anaphylaxis guidelines existed in 41% (15 of 37) of institutions. Teams used a cognitive aid for medication dosing 41% (15 of 37) of the time and 32% (12 of 37) for preparation. Epinephrine autoinjectors were not available in 54% (20 of 37) of institutions and were used in only 14% (5 of 37) of simulations. Median time to epinephrine administration was 95 seconds (interquartile range, 77-252) for epinephrine autoinjector and 263 seconds (interquartile range, 146-407.5) for manually prepared epinephrine (P = .12). At least 1 medication error occurred in 68% (25 of 37) of simulations. Nursing experience with epinephrine administration for anaphylaxis was associated with fewer preparation (P = .04) and administration (P = .01) errors. Latent safety threats were reported by 30% (11 of 37) of institutions, and more than half of these (6 of 11) involved a cognitive aid. Conclusions A multicenter, international study of simulated pediatric anaphylaxis reveals (1) variation in management between institutions in the use of protocols, cognitive aids, and medication formularies, (2) frequent errors involving epinephrine, and (3) latent safety threats related to cognitive aids among multiple sites
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