394 research outputs found

    Some Principles of Maritime Strategy

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    Near-universal hospitalization of US emergency department patients with cancer and febrile neutropenia

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    IMPORTANCE: Febrile neutropenia (FN) is the most common oncologic emergency and is among the most deadly. Guidelines recommend risk stratification and outpatient management of both pediatric and adult FN patients deemed to be at low risk of complications or mortality, but our prior single-center research demonstrated that the vast majority (95%) are hospitalized. OBJECTIVE: From a nationwide perspective, to determine the proportion of cancer patients of all ages hospitalized after an emergency department (ED) visit for FN, and to analyze variability in hospitalization rates. Our a priori hypothesis was that >90% of US cancer-associated ED FN visits would end in hospitalization. DESIGN: Analysis of data from the Nationwide Emergency Department Sample, 2006-2014. SETTING: Stratified probability sample of all US ED visits. PARTICIPANTS: Inclusion criteria were: (1) Clinical Classification Software code indicating cancer, (2) diagnostic code indicating fever, and (3) diagnostic code indicating neutropenia. We excluded visits ending in transfer. EXPOSURE: The hospital at which the visit took place. MAIN OUTCOMES AND MEASURES: Our main outcome is the proportion of ED FN visits ending in hospitalization, with an a priori hypothesis of >90%. Our secondary outcomes are: (a) hospitalization rates among subsets, and (b) proportion of variability in the hospitalization rate attributable to which hospital the patient visited, as measured by the intra-class correlation coefficient (ICC). RESULTS: Of 348,868 visits selected to be representative of all US ED visits, 94% ended in hospitalization (95% Confidence Interval [CI] 93-94%). Each additional decade of age conferred 1.23x increased odds of hospitalization. Those with private (92%), self-pay (92%), and other (93%) insurance were less likely to be hospitalized than those with public insurance (95%, odds ratios [OR] 0.74-0.76). Hospitalization was least likely at non-metropolitan hospitals (84%, OR 0.15 relative to metropolitan teaching hospitals), and was also less likely at metropolitan non-teaching hospitals (94%, OR 0.64 relative to metropolitan teaching hospitals). The ICC adjusted for hospital random effects and patient and hospital characteristics was 26% (95%CI 23-29%), indicating that 26% of the variability in hospitalization rate was attributable to which hospital the patient visited. CONCLUSIONS AND RELEVANCE: Nearly all cancer-associated ED FN visits in the US end in hospitalization. Inter-hospital variation in hospitalization practices explains 26% of the limited variability in hospitalization decisions. Simple, objective tools are needed to improve risk stratification for ED FN patients

    Development of a 2009 Stable Lights Product using DMSP-OLS data

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    Since 1994, NGDC has had an active program focused on global mapping of nighttime lights using the data collected by the Defense Meteorological Satellite Program’s Operational Linescan System (DMSP-OLS) sensors.  The basic product is a global annual cloud-free composite, which averages the OLS visible band data for one satellite from the cloud-free segments of individual orbits.  Over the years, NGDC has developed automatic algorithms for screening the quality of the nighttime visible band observations to remove areas contaminated by sunlight, moonlight, and the presence of clouds.  In the Stable Lights product generation, fires and other ephemeral lights are removed based on their high brightness and short duration.  Background noise is removed by setting thresholds based on visible band values found in areas known to be free of detectable lights.  In 2010, NGDC released the version 4 time series of Stable Lights, spanning the years 1992-2009.  These are available online at <http://www.ngdc.noaa.gov/dmsp/downloadV4composites.html>

    Mapping the Constructed Surface Area Density for China

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    Efforts to map the constructed surface area density of the world using nighttime satellite imagery have typically been validated using aerial photography or high resolution satellite imagery in the United States and extrapolating regression parameters to countries outside of the United States. In a previous study, we found China to have ‘paved’ more of the planet than any other country (~87,00 km2). Here we use a google earth based web application to validate our estimates of anthropogenic impervious surface (constructed area density) in China using actual imagery of China.  ‘Paving the Planet’ is a universal phenomenon – akin to clothing – and represents one of the primary anthropogenic modifications of the environment.  Expansion in population numbers and economies combined with the increased use of automobiles has led to the sprawl of development and a wide proliferation of constructed impervious surfaces. Constructed impervious surfaces are both hydrological and ecological disturbances.  However, constructed surfaces are different from most other types of disturbances in that recovery is arrested through the use of materials that are resistant to decay and are actively maintained. The same characteristics that make impervious surfaces ideal for use in construction produce a series of effects on the environment.  We present a new map of the density of constructed surface in China derived from DMSP nighttime lights and LandScan population count data

    A High Merger Fraction in the Rich Cluster MS1054-03 at z=0.83: Direct Evidence for Hierarchical Formation of Massive Galaxies

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    We present a morphological study of the galaxy population of the luminous X-ray cluster MS1054-03 at z=0.83. The sample consists of 81 spectroscopically confirmed cluster members in a 3 x 2 Mpc area imaged in F606W and F814W with WFPC2. We find thirteen ongoing mergers in MS1054-03, comprising 17% of the L > L* cluster population. Most of these mergers will likely evolve into luminous (\sim 2 L*) elliptical galaxies, and some may evolve into S0 galaxies. Assuming the galaxy population in MS1054-03 is typical for its redshift it is estimated that \sim 50% of present-day cluster ellipticals experienced a major merger at z < 1. The mergers are preferentially found in the outskirts of the cluster, and probably occur in small infalling clumps. Morphologies, spectra, and colors of the mergers show that their progenitors were typically E/S0s or early-type spirals with mean stellar formation redshifts z* \gtrsim 1.7. The red colors of the merger remnants are consistent with the low scatter in the color-magnitude relation in rich clusters at lower redshift. The discovery of a high fraction of mergers in this young cluster is direct evidence against formation of ellipticals in a single ``monolithic'' collapse at high redshift, and in qualitative agreement with predictions of hierarchical models for structure formation.Comment: Added GIF version of Figure 1. At http://www.astro.rug.nl/~dokkum/preprints/merger_fig1.eps.gz the PS file is available. Accepted for publication in ApJ Letter
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