303 research outputs found

    Wildfire Smoke Particle Properties and Evolution, from Space-Based Multi-Angle Imaging

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    Emitted smoke composition is determined by properties of the biomass burning source and ambient ecosystem. However, conditions that mediate the partitioning of black carbon (BC) and brown carbon (BrC) formation, as well as the spatial and temporal factors that drive particle evolution, are not understood adequately for many climate and air-quality related modeling applications. In situ observations provide considerable detail about aerosol microphysical and chemical properties, although sampling is extremely limited. Satellites offer the frequent global coverage that would allow for statistical characterization of emitted and evolved smoke, but generally lack microphysical detail. However, once properly validated, data from the National Aeronautics and Space Administration (NASA) Earth Observing Systems Multi-Angle Imaging Spectroradiometer (MISR) instrument can create at least a partial picture of smoke particle properties and plume evolution. We use in situ data from the Department of Energys Biomass Burning Observation Project (BBOP) field campaign to assess the strengths and limitations of smoke particle retrieval results from the MISR Research Aerosol (RA) retrieval algorithm. We then use MISR to characterize wildfire smoke particle properties and to identify the relevant aging factors in several cases, to the extent possible. The RA successfully maps qualitative changes in effective particle size, light absorption, and its spectral dependence, when compared to in situ observations. By observing the entire plume uniformly, the satellite data can be interpreted in terms of smoke plume evolution, including size-selective deposition, new-particle formation, and locations within the plume where BC or BrC dominates

    Barriers to adherence to COPD guidelines among primary care providers

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    Background: Despite efforts to disseminate guidelines for managing chronic obstructive pulmonary disease (COPD), adherence to COPD guidelines remains suboptimal. Barriers to adhering to guidelines remain poorly understood. Methods: Clinicians from two general medicine practices in New York City were surveyed to identify barriers to implementing seven recommendations from the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines. Barriers assessed included unfamiliarity, disagreement, low perceived benefit, low self-efficacy, and time constraints. Exact conditional regression was used to identify barriers independently associated with non-adherence. Results: The survey was completed by 154 clinicians. Adherence was lowest to referring patients with a forced expiratory volume in 1 s (FEV_1) <80% predicted to pulmonary rehabilitation (5%); using FEV_1 to guide management (12%); and ordering pulmonary function tests (PFTs) in smokers (17%). Adherence was intermediate to prescribing inhaled corticosteroids when FEV1 <50% predicted (41%) and long-acting bronchodilators when FEV1 <80% predicted (54%). Adherence was highest for influenza vaccination (90%) and smoking cessation counseling (91%). In unadjusted analyses, low familiarity with the guidelines, low self-efficacy, and time constraints were significantly associated with non-adherence to ≥2 recommendations. In adjusted analyses, low self-efficacy was associated with less adherence to prescribing inhaled corticosteroids (OR: 0.28; 95% CI: 0.10, 0.74) and time constraints were associated with less adherence to ordering PFTs in smokers (OR: 0.31; 95% CI: 0.08, 0.99). Conclusions: Poor familiarity with recommendations, low self-efficacy, and time constraints are important barriers to adherence to COPD guidelines. This information can be used to develop tailored interventions to improve guideline adherence

    Predicting Risk for Death from MRSA Bacteremia1

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    Methicillin-resistant Staphylococcus aureus (MRSA) in the bloodstream is often fatal. Vancomycin is the most frequently prescribed drug for treatment of MRSA infections with demonstrated efficacy. Recently, however, some MRSA infections have not been responding to vancomycin, even those caused by strains considered susceptible. To provide optimal treatment and avoid vancomycin resistance, therapy should be tailored, especially for patients at highest risk for death. But who are these patients? A study that looked back at medical records and 699 frozen isolates found that risk for death from MRSA infection was highest among certain populations, including the elderly, nursing home residents, patients with severe sepsis, and patients with liver or kidney disease. Risk for death was not affected by the type of MRSA strain (vancomycin susceptible, heteroresistant, or intermediate resistant). Risk was lower among those who had consulted an infectious disease specialist. Thus, when choosing treatment for patients with MRSA infection, it is crucial to look at patient risk factors, not just MRSA strain type. For those at high risk, consultation with an infectious disease specialist is recommended

    Rapid evolution of aerosol particles and their optical properties downwind of wildfires in the western US

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    During the first phase of the Biomass Burn Operational Project (BBOP) field campaign, conducted in the Pacific Northwest, the DOE G-1 aircraft was used to follow the time evolution of wildfire smoke from near the point of emission to locations 2-3.5 h downwind. In nine flights we made repeated transects of wildfire plumes at varying downwind distances and could thereby follow the plume\u27s time evolution. On average there was little change in dilution-normalized aerosol mass concentration as a function of downwind distance. This consistency hides a dynamic system in which primary aerosol particles are evaporating and secondary ones condensing. Organic aerosol is oxidized as a result. On all transects more than 90 % of aerosol is organic. In freshly emitted smoke aerosol, NH+4 is approximately equivalent to NO3. After 2 h of daytime aging, NH+4 increased and is approximately equivalent to the sum of Cl, SO24, and NO3. Particle size increased with downwind distance, causing particles to be more efficient scatters. Averaged over nine flights, mass scattering efficiency (MSE) increased in ∼ 2 h by 56 % and doubled in one flight. Mechanisms for redistributing mass from small to large particles are discussed. Coagulation is effective at moving aerosol from the Aitken to accumulation modes but yields only a minor increase in MSE. As absorption remained nearly constant with age, the time evolution of single scatter albedo was controlled by age-dependent scattering. Near-fire aerosol had a single scatter albedo (SSA) of 0.8-0.9. After 1 to 2 h of aging SSAs were typically 0.9 and greater. Assuming global-average surface and atmospheric conditions, the observed age dependence in SSA would change the direct radiative effect of a wildfire plume from near zero near the fire to a cooling effect downwind

    A draft framework for measuring progress towards the development of a national health information infrastructure

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    BACKGROUND: American public policy makers recently established the goal of providing the majority of Americans with electronic health records by 2014. This will require a National Health Information Infrastructure (NHII) that is far more complete than the one that is currently in its formative stage of development. We describe a conceptual framework to help measure progress toward that goal. DISCUSSION: The NHII comprises a set of clusters, such as Regional Health Information Organizations (RHIOs), which, in turn, are composed of smaller clusters and nodes such as private physician practices, individual hospitals, and large academic medical centers. We assess progress in terms of the availability and use of information and communications technology and the resulting effectiveness of these implementations. These three attributes can be studied in a phased approach because the system must be available before it can be used, and it must be used to have an effect. As the NHII expands, it can become a tool for evaluating itself. SUMMARY: The NHII has the potential to transform health care in America – improving health care quality, reducing health care costs, preventing medical errors, improving administrative efficiencies, reducing paperwork, and increasing access to affordable health care. While the President has set an ambitious goal of assuring that most Americans have electronic health records within the next 10 years, a significant question remains "How will we know if we are making progress toward that goal?" Using the definitions for "nodes" and "clusters" developed in this article along with the resulting measurement framework, we believe that we can begin a discussion that will enable us to define and then begin making the kinds of measurements necessary to answer this important question

    Fine Ash-Bearing Particles as a Major Aerosol Component in Biomass Burning Smoke

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    Biomass burning (BB) events are occurring globally with increasing frequency, and their emissions are having more impacts on human health and climate. Large ash particles are recognized as a BB product with major influences on soil and water environments. However, fine-ash particles, which have diameters smaller than several microns and characteristic morphologies and compositions (mainly Ca and Mg carbonates), have not yet been explicitly considered as a major BB aerosol component either in field observations or climate models. This study measured BB aerosol samples using transmission electron microscopy (TEM) and ion chromatography during the Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) campaign. We show that significant amounts of fine ash-bearing particles are transported \u3e100 km from their fire sources. Our environmental chamber experiments suggest that they can act as cloud condensation and ice nuclei. We also found considerable amounts of fine ash-bearing particles in the TEM samples collected during previous campaigns (Biomass Burning Observation Project and Megacity Initiative: Local and Global Research Observations). These ash particles are commonly mixed with organic matter and make up ∼8% and 5% of BB smoke by number and mass, respectively, in samples collected during the FIREX-AQ campaign. The measured ash-mass concentrations are approximately five times and six times greater than those of BB black carbon and potassium, respectively, scaling to an estimated global emission of 11.6 Tg yr−1 with a range of 8.8–16.3 Tg yr−1. Better characterization and constraints on these fine ash-bearing particles will improve BB aerosol measurements and strengthen assessments of BB impacts on human health and climate
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