105 research outputs found
Multi-scale modeling study of the source contributions to near-surface ozone and sulfur oxides levels over California during the ARCTAS-CARB period
Chronic high surface ozone (O_3) levels and the increasing sulfur oxides (SO_x = SO_2 + SO_4) ambient concentrations over South Coast (SC) and other areas of California (CA) are affected by both local emissions and long-range transport. In this paper, multi-scale tracer, full-chemistry and adjoint simulations using the STEM atmospheric chemistry model are conducted to assess the contribution of local emission sourcesto SC O_3 and to evaluate the impacts of transported sulfur and local emissions on the SC sulfur budgetduring the ARCTAS-CARB experiment period in 2008. Sensitivity simulations quantify contributions of biogenic and fire emissions to SC O_3 levels. California biogenic and fire emissions contribute 3–4 ppb to near-surface O_3 over SC, with larger contributions to other regions in CA. During a long-range transport event from Asia starting from 22 June, high SO_x levels (up to ~0.7 ppb of SO_2 and ~1.3 ppb of SO_4) is observed above ~6 km, but they did not affect CA surface air quality. The elevated SO_x observed at 1–4 km is estimated to enhance surface SO_x over SC by ~0.25 ppb (upper limit) on ~24 June. The near-surface SO_x levels over SC during the flight week are attributed mostly to local emissions. Two anthropogenic SO_x emission inventories (EIs) from the California Air Resources Board (CARB) and the US Environmental Protection Agency (EPA) are compared and applied in 60 km and 12 km chemical transport simulations, and the results are compared withobservations. The CARB EI shows improvements over the National Emission Inventory (NEI) by EPA, but generally underestimates surface SC SO_x by about a factor of two. Adjoint sensitivity analysis indicated that SO_2 levels at 00:00 UTC (17:00 local time) at six SC surface sites were influenced by previous day maritime emissions over the ocean, the terrestrial emissions over nearby urban areas, and by transported SO_2 from the north through both terrestrial and maritime areas. Overall maritime emissions contribute 10–70% of SO2 and 20–60% fine SO_4 on-shore and over the most terrestrial areas, with contributions decreasing with in-land distance from the coast. Maritime emissions also modify the photochemical environment, shifting O_3 production over coastal SC to more VOC-limited conditions. These suggest an important role for shipping emission controls in reducing fine particle and O_3 concentrations in SC
Multi-scale modeling study of the source contributions to near-surface ozone and sulfur oxides levels over California during the ARCTAS-CARB period
Chronic high surface ozone (O3) levels and the increasing sulfur oxides (SOx = SO2+SO4) ambient concentrations over South Coast (SC) and other areas of California (CA) are affected by both local emissions and long-range transport. In this paper, multi-scale tracer, full-chemistry and adjoint simulations using the STEM atmospheric chemistry model are conducted to assess the contribution of local emission sourcesto SC O3 and to evaluate the impacts of transported sulfur and local emissions on the SC sulfur budgetduring the ARCTAS-CARB experiment period in 2008. Sensitivity simulations quantify contributions of biogenic and fire emissions to SC O3 levels. California biogenic and fire emissions contribute 3–4 ppb to near-surface O3 over SC, with larger contributions to other regions in CA. During a long-range transport event from Asia starting from 22 June, high SOx levels (up to ~0.7 ppb of SO2 and ~1.3 ppb of SO4) is observed above ~6 km, but they did not affect CA surface air quality. The elevated SOx observed at 1–4 km is estimated to enhance surface SOx over SC by ~0.25 ppb (upper limit) on ~24 June. The near-surface SOx levels over SC during the flight week are attributed mostly to local emissions. Two anthropogenic SOx emission inventories (EIs) from the California Air Resources Board (CARB) and the US Environmental Protection Agency (EPA) are compared and applied in 60 km and 12 km chemical transport simulations, and the results are compared withobservations. The CARB EI shows improvements over the National Emission Inventory (NEI) by EPA, but generally underestimates surface SC SOx by about a factor of two. Adjoint sensitivity analysis indicated that SO2 levels at 00:00 UTC (17:00 local time) at six SC surface sites were influenced by previous day maritime emissions over the ocean, the terrestrial emissions over nearby urban areas, and by transported SO2 from the north through both terrestrial and maritime areas. Overall maritime emissions contribute 10–70% of SO2 and 20–60% fine SO4 on-shore and over the most terrestrial areas, with contributions decreasing with in-land distance from the coast. Maritime emissions also modify the photochemical environment, shifting O3 production over coastal SC to more VOC-limited conditions. These suggest an important role for shipping emission controls in reducing fine particle and O3concentrations in SC
Assessing regional scale predictions of aerosols, marine stratocumulus, and their interactions during VOCALS-REx using WRF-Chem
This study assesses the ability of the recent chemistry version (v3.3) of the Weather Research and Forecasting (WRF-Chem) model to simulate boundary layer structure, aerosols, stratocumulus clouds, and energy fluxes over the Southeast Pacific Ocean. Measurements from the VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx) and satellite retrievals (i.e., products from the MODerate resolution Imaging Spectroradiometer (MODIS), Clouds and Earth's Radiant Energy System (CERES), and GOES-10) are used for this assessment. The Morrison double-moment microphysics scheme is newly coupled with interactive aerosols in the model. The 31-day (15 October–16 November 2008) WRF-Chem simulation with aerosol-cloud interactions (AERO hereafter) is also compared to a simulation (MET hereafter) with fixed cloud droplet number concentrations in the microphysics scheme and simplified cloud and aerosol treatments in the radiation scheme. The well-simulated aerosol quantities (aerosol number, mass composition and optical properties), and the inclusion of full aerosol-cloud couplings lead to significant improvements in many features of the simulated stratocumulus clouds: cloud optical properties and microphysical properties such as cloud top effective radius, cloud water path, and cloud optical thickness. In addition to accounting for the aerosol direct and semi-direct effects, these improvements feed back to the simulation of boundary-layer characteristics and energy budgets. Particularly, inclusion of interactive aerosols in AERO strengthens the temperature and humidity gradients within the capping inversion layer and lowers the marine boundary layer (MBL) depth by 130 m from that of the MET simulation. These differences are associated with weaker entrainment and stronger mean subsidence at the top of the MBL in AERO. Mean top-of-atmosphere outgoing shortwave fluxes, surface latent heat, and surface downwelling longwave fluxes are in better agreement with observations in AERO, compared to the MET simulation. Nevertheless, biases in some of the simulated meteorological quantities (e.g., MBL temperature and humidity) and aerosol quantities (e.g., underestimations of accumulation mode aerosol number) might affect simulated stratocumulus and energy fluxes over the Southeastern Pacific, and require further investigation. The well-simulated timing and outflow patterns of polluted and clean episodes demonstrate the model's ability to capture daily/synoptic scale variations of aerosol and cloud properties, and suggest that the model is suitable for studying atmospheric processes associated with pollution outflow over the ocean. The overall performance of the regional model in simulating mesoscale clouds and boundary layer properties is encouraging and suggests that reproducing gradients of aerosol and cloud droplet concentrations and coupling cloud-aerosol-radiation processes are important when simulating marine stratocumulus over the Southeast Pacific
Real-world experience with a Paclitaxel-Coated Balloon for the treatment of atherosclerotic infrainguinal arteries: 12-month interim results of the BIOLUX P-III registry first year of enrolment = Experiência real com balão revestido com paclitaxel para o tratamento de artérias infrainguinais ateroscleróticas: resultados após 12 meses do primeiro ano de seleção de pacientes para o registro BIOLUX P-III
Background: Endovascular management of atherosclerotic infrainguinal arteries recently shifted towards drug eluting devices, designed to locally prevent the restenosis process. Numerous clinical studies report an advantage of drug coated balloons over uncoated balloon angioplasty in treating lower extremity peripheral artery disease. However, as coating and balloon platforms are different, each device requires dedicated clinical evaluations. Objective: The aim of the study is to further investigate the safety and effectiveness of a Paclitaxel-Coated Balloon for the treatment of atherosclerotic infrainguinal arteries in a real-world setting. Methods: 203 patients out of a final sample of 882 were enrolled in this prospective multicenter, observational, all-comers registry during the first 12 months. The primary endpoints were major adverse events (defined as procedure or device related death within 30 days post index procedure, clinically-driven target lesion revascularization or major target limb amputation) at 6 months and freedom from clinically-driven target lesion revascularization at 12 months. Both endpoints were adjudicated by a Clinical Events Committee. Results: Mean patient age was 70.2\ub110.4 years (60.1% male). 47.3% of the patients were diabetic and 67.5% had a history of smoking. Severe claudication was reported in 37.4% and 40% had critical limb ischemia. 257 lesions, including 13.2% in the infrapopliteal territory, were treated with Passeo-18 Lux (mean lesion length 75.1 mm\ub169.4, 20% occlusions, 76.3% calcified). At 6 months, the rate of major adverse events was 5.5% (95%CI 3.1-9.7). Freedom from clinically-driven target lesion revascularization at 12 months was 93.2% (95%CI 89.1-95.8). All causes mortality was 6.5% (95%CI 3.8-11.0) and overall amputation rate was 4.2% (95%CI 2.1-8.3) at 12 months. Conclusion: In a real-world environment, the BIOLUX P-III registry preliminary results confirm the safety and efficacy of the Paclitaxel-Coated Passeo-18 Lux balloon as a stand-alone treatment option for atherosclerotic infrainguinal arteries.Contexto: O manejo endovascular de art\ue9rias infrainguinais ateroscler\uf3ticas recentemente tem mudado para dispositivos farmacol\uf3gicos, desenhados para impedir localmente o processo de reestenose. Numerosos estudos cl\uednicos descrevem uma vantagem da angioplastia com uso de bal\uf5es farmacol\uf3gicos sobre os bal\uf5es convencionais no tratamento de doen\ue7a arterial perif\ue9rica dos membros inferiores. No entanto, considerando que as plataformas do revestimento farmacol\uf3gico e dos bal\uf5es s\ue3o diferentes, cada dispositivo requer avalia\ue7\uf5es cl\uednicas espec\uedficas. Objetivo: Fazer investiga\ue7\ue3o adicional sobre a seguran\ue7a e efic\ue1cia de um bal\ue3o revestido com paclitaxel para o tratamento de art\ue9rias infrainguinais ateroscler\uf3ticas em um cen\ue1rio de mundo real. M\ue9todos: 203 pacientes de uma amostra final de 882 pacientes foram inclu\ueddos neste registro prospectivo observacional multic\ueantrico de inclus\ue3o sequencial, durante os primeiros 12 meses. Os desfechos prim\ue1rios foram eventos adversos maiores (definidos como morte relacionada ao procedimento ou ao dispositivo em at\ue9 30 dias ap\uf3s o procedimento-\uedndice, necessidade de revasculariza\ue7\ue3o da les\ue3o-alvo ou amputa\ue7\ue3o significativa do membro-alvo) em 6 meses e aus\ueancia de de revasculariza\ue7\ue3o da les\ue3o-alvo em 12 meses. Ambos os desfechos foram adjudicados por um comit\uea de eventos cl\uednicos. Resultados: A idade m\ue9dia foi 70,2\ub110,4 anos (60,1% sexo masculino). 47,3% dos pacientes eram diab\ue9ticos, e 67,5% tinham hist\uf3ria de tabagismo. Claudica\ue7\ue3o severa foi relatada em 37,4%, e 40% apresentava isquemia cr\uedtica de membro. 257 les\uf5es, incluindo 13,2% em territ\uf3rio infrapopl\uedteo, foram tratadas com o bal\ue3o Passeo-18 Lux (comprimento m\ue9dio das les\uf5es 75,1 mm\ub169,4, 20% oclus\uf5es, 76,3% calcificadas). Aos 6 meses, a taxa de eventos adversos maiores foi de 5,5% (95%CI 3,1-9,7). A aus\ueancia de revasculariza\ue7\ue3o da les\ue3o-alvo aos 12 meses foi de 93,2% (95%CI 89,1-95,8). Mortalidade por todas as causas foi de 6,5% (95%CI 3,8-11,0) e a taxa geral de amputa\ue7\ue3o foi de 4,2% (95%CI 2,1-8,3) aos 12 meses. Conclus\ue3o: Em um cen\ue1rio de mundo real, os resultados preliminares do registro BIOLUX P-III confirmam a seguran\ue7a e efic\ue1cia do bal\ue3o revestido com paclitaxel Passeo-18 Lux como op\ue7\ue3o de tratamento \ufanico para art\ue9rias infrainguinais ateroscler\uf3ticas
Use of SMS texts for facilitating access to online alcohol interventions: a feasibility study
A41 Use of SMS texts for facilitating access to online alcohol interventions: a feasibility study
In: Addiction Science & Clinical Practice 2017, 12(Suppl 1): A4
Isolated patellofemoral osteoarthritis: A systematic review of treatment options using the GRADE approach
Background and purpose The optimal treatment for isolated patellofemoral osteoarthritis is unclear at present. We systematically reviewed the highest level of available evidence on the nonoperative and operative treatment of isolated patellofemoral osteoarthritis to develop an evidenced-based discussion of treatment options
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Evaluating WRF-Chem aerosol indirect effects in Southeast Pacific marine stratocumulus during VOCALS-REx
We evaluate a regional-scale simulation with the WRF-Chem model for the VAMOS (Variability of the American Monsoon Systems) Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx), which sampled the Southeast Pacific's persistent stratocumulus deck. Evaluation of VOCALS-REx ship-based and three aircraft observations focuses on analyzing how aerosol loading affects marine boundary layer (MBL) dynamics and cloud microphysics. We compare local time series and campaign-averaged longitudinal gradients, and highlight differences in model simulations with (W) and without (NW) wet deposition processes. The higher aerosol loadings in the NW case produce considerable changes in MBL dynamics and cloud microphysics, in accordance with the established conceptual model of aerosol indirect effects. These include increase in cloud albedo, increase in MBL and cloud heights, drizzle suppression, increase in liquid water content, and increase in cloud lifetime. Moreover, better statistical representation of aerosol mass and number concentration improves model fidelity in reproducing observed spatial and temporal variability in cloud properties, including top and base height, droplet concentration, water content, rain rate, optical depth (COD) and liquid water path (LWP). Together, these help to quantify confidence in WRF-Chem's modeled aerosol-cloud interactions, especially in the activation parameterization, while identifying structural and parametric uncertainties including: irreversibility in rain wet removal; overestimation of marine DMS and sea salt emissions, and accelerated aqueous sulfate conversion. Our findings suggest that WRF-Chem simulates marine cloud-aerosol interactions at a level sufficient for applications in forecasting weather and air quality and studying aerosol climate forcing, and may do so with the reliability required for policy analysis.Keywords: Cellular structures,
Low level jet,
Hydrogen peroxide,
Regional experiment,
Model development,
Large eddy simulation,
Cloud micropysics,
General circulation,
Atmospheric sulfur,
Boundary layerThis is the publisher’s final pdf. The published article is copyrighted by European Geosciences Union and can be found at: http://www.egu.eu/
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