3,742 research outputs found
Thiopentone sedation for sedation of acutely agitated, violent, intoxicated patients: Evaluation of 2 cases
Two cases of violent, drug-intoxicated patients who presented considerable problems in management, and were resistant to standard sedative agents, are described. Effective and safe sedation, without the need for full anaesthesia and endotracheal intubation, was achieved using titrated doses of thiopentone. The merits of selecting this agent in these circumstances are discussed
Validation of frequency and mode extraction calculations from time-domain simulations of accelerator cavities
The recently developed frequency extraction algorithm [G.R. Werner and J.R.
Cary, J. Comp. Phys. 227, 5200 (2008)] that enables a simple FDTD algorithm to
be transformed into an efficient eigenmode solver is applied to a realistic
accelerator cavity modeled with embedded boundaries and Richardson
extrapolation. Previously, the frequency extraction method was shown to be
capable of distinguishing M degenerate modes by running M different simulations
and to permit mode extraction with minimal post-processing effort that only
requires solving a small eigenvalue problem. Realistic calculations for an
accelerator cavity are presented in this work to establish the validity of the
method for realistic modeling scenarios and to illustrate the complexities of
the computational validation process. The method is found to be able to extract
the frequencies with error that is less than a part in 10^5. The corrected
experimental and computed values differ by about one parts in 10^$, which is
accounted for (in largest part) by machining errors. The extraction of
frequencies and modes from accelerator cavities provides engineers and
physicists an understanding of potential cavity performance as it depends on
shape without incurring manufacture and measurement costs
Use of Social Media Across US Hospitals: Descriptive Analysis of Adoption and Utilization
Background: Use of social media has become widespread across the United States. Although businesses have invested in social media to engage consumers and promote products, less is known about the extent to which hospitals are using social media to interact with patients and promote health.
Objective: The aim was to investigate the relationship between hospital social media extent of adoption and utilization relative to hospital characteristics.
Methods: We conducted a cross-sectional review of hospital-related activity on 4 social media platforms: Facebook, Twitter, Yelp, and Foursquare. All US hospitals were included that reported complete data for the Centers for Medicare and Medicaid Services Hospital Consumer Assessment of Healthcare Providers and Systems survey and the American Hospital Association Annual Survey. We reviewed hospital social media webpages to determine the extent of adoption relative to hospital characteristics, including geographic region, urban designation, bed size, ownership type, and teaching status. Social media utilization was estimated from user activity specific to each social media platform, including number of Facebook likes, Twitter followers, Foursquare check-ins, and Yelp reviews.
Results: Adoption of social media varied across hospitals with 94.41% (3351/3371) having a Facebook page and 50.82% (1713/3371) having a Twitter account. A majority of hospitals had a Yelp page (99.14%, 3342/3371) and almost all hospitals had check-ins on Foursquare (99.41%, 3351/3371). Large, urban, private nonprofit, and teaching hospitals were more likely to have higher utilization of these accounts.
Conclusions: Although most hospitals adopted at least one social media platform, utilization of social media varied according to several hospital characteristics. This preliminary investigation of social media adoption and utilization among US hospitals provides the framework for future studies investigating the effect of social media on patient outcomes, including links between social media use and the quality of hospital care and services
V605 Aquilae: a born again star, a nova or both?
V605 Aquilae is today widely assumed to have been the result of a final
helium shell flash occurring on a single post-asymptotic giant branch star. The
fact that the outbursting star is in the middle of an old planetary nebula and
that the ejecta associated with the outburst is hydrogen deficient supports
this diagnosis. However, the material ejected during that outburst is also
extremely neon rich, suggesting that it derives from an oxygen-neon-magnesium
star, as is the case in the so-called neon novae. We have therefore attempted
to construct a scenario that explains all the observations of the nebula and
its central star, including the ejecta abundances. We find two scenarios that
have the potential to explain the observations, although neither is a perfect
match. The first scenario invokes the merger of a main sequence star and a
massive oxygen-neon-magnesium white dwarf. The second invokes an
oxygen-neon-magnesium classical nova that takes place shortly after a final
helium shell flash. The main drawback of the first scenario is the inability to
determine whether the ejecta would have the observed composition and whether a
merger could result in the observed hydrogen-deficient stellar abundances
observed in the star today. The second scenario is based on better understood
physics, but, through a population synthesis technique, we determine that its
frequency of occurrence should be very low and possibly lower than what is
implied by the number of observed systems. While we could not envisage a
scenario that naturally explains this object, this is the second final flash
star which, upon closer scrutiny, is found to have hydrogen-deficient ejecta
with abnormally high neon abundances. These findings are in stark contrast with
the predictions of the final helium shell flash and beg for an alternative
explanation.Comment: 8 pages, 1 figures, 2 tables, accepted for MNRAS. Better title and
minor corrections compared to previous versio
Storm-induced inner-continental shelf circulation and sediment transport : Long Bay, South Carolina
This paper is not subject to U.S. copyright. The definitive version was published in Continental Shelf Research 42 (2012): 51–63, doi:10.1016/j.csr.2012.05.001.Long Bay is a sediment-starved, arcuate embayment located along the US East Coast connecting both South and North Carolina. In this region the rates and pathways of sediment transport are important because they determine the availability of sediments for beach nourishment, seafloor habitat, and navigation. The impact of storms on sediment transport magnitude and direction were investigated during the period October 2003–April 2004 using bottom mounted flow meters, acoustic backscatter sensors and rotary sonars deployed at eight sites offshore of Myrtle Beach, SC, to measure currents, water levels, surface waves, salinity, temperature, suspended sediment concentrations, and bedform morphology. Measurements identify that sediment mobility is caused by waves and wind driven currents from three predominant types of storm patterns that pass through this region: (1) cold fronts, (2) warm fronts and (3) low-pressure storms. The passage of a cold front is accompanied by a rapid change in wind direction from primarily northeastward to southwestward. The passage of a warm front is accompanied by an opposite change in wind direction from mainly southwestward to northeastward. Low-pressure systems passing offshore are accompanied by a change in wind direction from southwestward to southeastward as the offshore storm moves from south to north.
During the passage of cold fronts more sediment is transported when winds are northeastward and directed onshore than when the winds are directed offshore, creating a net sediment flux to the north–east. Likewise, even though the warm front has an opposite wind pattern, net sediment flux is typically to the north–east due to the larger fetch when the winds are northeastward and directed onshore. During the passage of low-pressure systems strong winds, waves, and currents to the south are sustained creating a net sediment flux southwestward. During the 3-month deployment a total of 8 cold fronts, 10 warm fronts, and 10 low-pressure systems drove a net sediment flux southwestward. Analysis of a 12-year data record from a local buoy shows an average of 41 cold fronts, 32 warm fronts, and 26 low-pressure systems per year. The culmination of these events would yield a cumulative net inner-continental shelf transport to the south–west, a trend that is further verified by sediment textural analysis and bedform morphology on the inner-continental shelf.This research was funded by the South Carolina Coastal
Erosion Project(http://pubs.usgs.gov/fs/2005/3041/), a cooperative study supported by the US Geological Survey and the South
Carolina Sea Grant Consortium(Sea Grant Project no:R/CP-11)
Acceleration of a stratified current over a sloping bottom, driven by an alongshelf pressure gradient
Author Posting. © American Meteorological Society, 2005. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 35 (2005): 1305-1317, doi:10.1175/JPO2744.1.An idealized theoretical model is developed for the acceleration of a two-dimensional, stratified current over a uniformly sloping bottom, driven by an imposed alongshelf pressure gradient and taking into account the effects of buoyancy advection in the bottom boundary layer. Both downwelling and upwelling pressure gradients are considered. For a specified pressure gradient, the model response depends primarily on the Burger number S = Nα/f, where N is the initial buoyancy frequency, α is the bottom slope, and f is the Coriolis parameter. Without stratification (S = 0), buoyancy advection is absent, and the alongshelf flow accelerates until bottom stress balances the imposed pressure gradient. The e-folding time scale to reach this steady state is the friction time, h/r, where h is the water depth and r is a linear bottom friction coefficient. With stratification (S ≠0), buoyancy advection in the bottom boundary layer produces vertical shear, which prevents the bottom stress from becoming large enough to balance the imposed pressure gradient for many friction time scales. Thus, the alongshelf flow continues to accelerate, potentially producing large velocities. The acceleration increases rapidly with increasing S, such that even relatively weak stratification (S > 0.2) has a major impact. These results are supported by numerical model calculations.Funding was provided by the Division
of Ocean Sciences of the National Science Foundation
under Grant OCE-0241292. DCC also received
some support from the Office of Naval Research under
Grants N00014-00-1-0210 and N00014-02-1-0767
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