464 results on '"Brett, B"'
Search Results
2. Atmospheric OH reactivity in the western United States determined from comprehensive gas-phase measurements during WE-CAN
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Wade Permar, Lixu Jin, Qiaoyun Peng, Katelyn O'Dell, Emily Lill, Vanessa Selimovic, Robert J. Yokelson, Rebecca S. Hornbrook, Alan J. Hills, Eric C. Apel, I-Ting Ku, Yong Zhou, Barkley C. Sive, Amy P. Sullivan, Jeffrey L. Collett, Brett B. Palm, Joel A. Thornton, Frank Flocke, Emily V. Fischer, and Lu Hu
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Chemistry (miscellaneous) ,Environmental Chemistry ,Pollution ,Analytical Chemistry - Abstract
Using OH reactivity we assess the major daytime OH radical sinks in western U.S. wildfire plumes and other smoke impacted environments, testing their current model representation while providing a roadmap for future model development.
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- 2023
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3. Formation and Evolution of Catechol-Derived SOA Mass, Composition, Volatility, and Light Absorption
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Carley D. Fredrickson, Brett B. Palm, Ben H. Lee, Xuan Zhang, John J. Orlando, Geoffrey S. Tyndall, Lauren A. Garofalo, Matson A. Pothier, Delphine K. Farmer, Zachary C. J. Decker, Michael A. Robinson, Steven S. Brown, Shane M. Murphy, Yingjie Shen, Amy P. Sullivan, Siegfried Schobesberger, and Joel A. Thornton
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Atmospheric Science ,Space and Planetary Science ,Geochemistry and Petrology - Published
- 2022
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4. Severe Thrombocytopenia in Patients With Advanced Neuroendocrine Tumor Treated With Peptide Receptor Radioligand Therapy
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Junid A. Naveed Ahmad, Brett B. Schroeder, Steven M. Ruhoy, Hagen F. Kennecke, and Bruce S. Lin
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Neuroendocrine Tumors ,Receptors, Peptide ,Positron-Emission Tomography ,Organometallic Compounds ,Humans ,Radiology, Nuclear Medicine and imaging ,General Medicine ,Octreotide ,Radionuclide Imaging ,Thrombocytopenia ,Retrospective Studies - Abstract
Peptide receptor radioligand therapy (PRRT) was Food and Drug Administration approved in 2018 for the treatment of unresectable somatostatin receptor-positive gastroenteropancreatic neuroendocrine tumors (NETs) and provides an important option for patients with advanced disease. A known adverse effect of this treatment is hematologic toxicity, although usually transient. We present 3 patients with metastatic gastroenteropancreatic NETs treated with PRRT who were evaluated for severe persistent thrombocytopenia.Three patients who commenced therapy with PRRT were known to proceed to a bone marrow (BM) biopsy for persistent severe thrombocytopenia and were included in this study. These patients were identified retrospectively and evaluated for their tumor properties, including immunohistochemical markers, treatment modalities, and clinical outcomes.All 3 patients had metastatic NETs that progressed on prior lines of therapy and were treated with 1 to 4 doses of 177Lu-DOTATATE 7.4 GBq (200 mCi) before developing grade 3 (25,000 to 50,000/μL) refractory thrombocytopenia. All patients had concurrent bone metastases, and 2 of the 3 had baseline grade 1 thrombocytopenia. In all 3 cases, BM biopsy documented widespread tumor infiltration.Severe refractory thrombocytopenia after PRRT is rare and may result from numerous known causes, including radiation-induced myelotoxicity, myelodysplastic syndrome, and tumor BM infiltration. We present 3 cases of thrombocytopenia related to persistent or progressive BM metastasis. Although known bone metastasis is not a contraindication to PRRT, thrombocytopenia may be a manifestation of tumor progression and should be considered when making decisions about continuation of therapy.
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- 2022
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5. Effects of non-native Salmo trutta and multiscale habitat factors on native fishes in the Driftless Area
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Brett B. Kelly, Michael J. Siepker, and Michael J. Weber
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Aquatic Science ,Ecology, Evolution, Behavior and Systematics - Abstract
We collected fishes and habitat data at 138 streams to evaluate the effects of introduced brown trout ( Salmo trutta) and habitat conditions on occurrence, detection, abundance, and size structure of sculpin ( Cottus spp.), longnose dace ( Rhinichthys cataractae), and southern redbelly dace ( Chrosomus erythrogaster) in the Driftless Area, USA. Sculpin detection decreased with increasing stream velocity, whereas southern redbelly dace detection increased with stream depth. Sculpin occupancy declined with increasing stream temperature and velocity and increased with increasing forested land, boulder substrate, and brown trout length and abundance. Longnose and southern redbelly dace occupancy and abundance declined with increasing brown trout abundance and occupancy increased with stream temperature. Longnose dace occupancy also increased with increasing stream temperature and cobble substrate and declined with increasing elevation. Native fish size structure was unrelated to brown trout presence. Our results suggest that effects of brown trout are not ubiquitous across native fishes and depend on abiotic conditions and species-specific habitat requirements, highlighting the need to consider both biotic and abiotic conditions when balancing native species conservation with introduced sportfish management.
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- 2023
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6. The CU Airborne Solar Occultation Flux Instrument: Performance Evaluation during BB-FLUX
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Natalie Kille, Kyle J. Zarzana, Johana Romero Alvarez, Christopher F. Lee, Jake P. Rowe, Benjamin Howard, Teresa Campos, Alan Hills, Rebecca S. Hornbrook, Ivan Ortega, Wade Permar, I Ting Ku, Jakob Lindaas, Ilana B. Pollack, Amy P. Sullivan, Yong Zhou, Carley D. Fredrickson, Brett B. Palm, Qiaoyun Peng, Eric C. Apel, Lu Hu, Jeffrey L. Collett, Emily V. Fischer, Frank Flocke, James W. Hannigan, Joel Thornton, and Rainer Volkamer
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Atmospheric Science ,Space and Planetary Science ,Geochemistry and Petrology - Published
- 2022
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7. Effects of Beaver Dams on Stream and Riparian Conditions on Public Lands in the United States' Inland Northwest
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Brett B. Roper
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Ecology ,Ecology, Evolution, Behavior and Systematics - Published
- 2022
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8. Observations and Modeling of NOx Photochemistry and Fate in Fresh Wildfire Plumes
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Teresa Campos, Amy P. Sullivan, Carley D. Fredrickson, Frank Flocke, Delphine K. Farmer, Lu Hu, Qiaoyun Peng, Wade Permar, Ben H. Lee, Joel A. Thornton, Samuel R. Hall, Emily V. Fischer, Matson A. Pothier, Eric C. Apel, Andrew J. Weinheimer, I-Ting Ku, Kirk Ullmann, Brett B. Palm, Jeffrey L. Collett, and Lauren A. Garofalo
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Atmospheric Science ,Space and Planetary Science ,Geochemistry and Petrology ,Environmental chemistry ,Environmental science ,NOx - Published
- 2021
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9. Direct Constraints on Secondary HONO Production in Aged Wildfire Smoke From Airborne Measurements Over the Western US
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Qiaoyun Peng, Brett B. Palm, Carley D. Fredrickson, Ben H. Lee, Samuel R. Hall, Kirk Ullmann, Andrew J. Weinheimer, Ezra Levin, Paul DeMott, Lauren A. Garofalo, Matson A. Pothier, Delphine K. Farmer, Emily V. Fischer, and Joel A. Thornton
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Geophysics ,General Earth and Planetary Sciences - Published
- 2022
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10. A Case of Post-Fever Retinitis in a Patient with Positive Lyme Borreliosis Serology
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Brett B. Zerbinopoulos, Joseph V. Mega, Paul B. Greenberg, Robert H. Janigian, and Rebecca Doyle
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Background: Lyme Borreliosis accounts for less than 1% of all uveitis cases. The challenge in diagnosing Lyme-associated uveitis in a seropositive patient is determining whether the serology status is causative or incidental. We describe a case that illustrates this challenge: a post-fever retinitis in a patient with persistent positive Lyme serology. Case Presentation: A patient presented to the eye clinic with complaints of blur and foreign body sensation in his right eye after getting sawdust in his eye. Further lab workup was only remarkable for Lyme IgG and IgM and the patient was subsequently diagnosed with a post-fever retinitis. Management and Outcomes: The patient was treated with oral prednisone, and a subsequent IOP spike was managed with topical ocular hypotensive drops until the course of steroid therapy was completed. The uveitis resolved over seven weeks. Conclusions: Post-fever retinitis is a diagnosis of exclusion, and diagnosis can be challenging in the presence of positive serology for other known causes of uveitis. This case highlights the importance of detailed case history and clinical findings in determining alternative causes of uveitis in patients with positive LB serology. CE Notification: This article is available as a COPE accredited CE course. You may take this course for 1-hour credit. Read the article and take the qualifying test to earn your credit. Click here to Enroll (https://www.crojournal.com/a-case-of-post-fever-retinitis-in-a-patient-with-positive-lyme-borreliosis-serology) Please check COPE course expiry date prior to enrollment. The COPE course test must be taken before the course expiry date.
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- 2022
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11. An unusual case of Cardiobacterium valvarum causing aortic endograft infection and osteomyelitis
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Brett B. Yarusi, Eric G. Hauser, Karen M. Krueger, and Imran Nizamuddin
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Microbiology (medical) ,Male ,medicine.medical_specialty ,HACEK organisms ,lcsh:QR1-502 ,Eikenella corrodens ,Cardiobacterium ,Transplants ,Aorta, Thoracic ,Case Report ,lcsh:Microbiology ,lcsh:Infectious and parasitic diseases ,03 medical and health sciences ,0302 clinical medicine ,Phlegmon ,Aortic endograft infection ,medicine ,Vertebral osteomyelitis ,Humans ,lcsh:RC109-216 ,030212 general & internal medicine ,education ,Aorta ,0303 health sciences ,education.field_of_study ,biology ,Endocarditis ,030306 microbiology ,business.industry ,Osteomyelitis ,lcsh:RM1-950 ,Cardiobacterium valvarum ,General Medicine ,Endocarditis, Bacterial ,Middle Aged ,medicine.disease ,biology.organism_classification ,Surgery ,Anti-Bacterial Agents ,Infectious Diseases ,lcsh:Therapeutics. Pharmacology ,Infective endocarditis ,Discitis ,business - Abstract
Background HACEK (Haemophilus spp., Aggregatibacter spp., Cardiobacterium spp., Eikenella corrodens, and Kingella spp.) group organisms are responsible for 0.8% to 6% of all infective endocarditis cases, with Cardiobacterium spp. being the third most commonly implicated HACEK microorganism. Within this genus is Cardiobacterium valvarum (C. valvarum), a novel organism described in 2004. To date, only 15 cases of C. valvarum infection have been reported in the English-language literature, and have primarily been cases of infective endocarditis in patients with valvular disease. C. valvarum has not been reported to cause infections spreading to the surrounding bone. Case presentation We present a case of a 57-year-old man with a history of aortic dissection followed by aortic endograft replacement who presented with back pain. He was found to have radiographic evidence of an infected aortic endograft, along with vertebral osteomyelitis, discitis, and epidural phlegmon. Blood cultures identified C. valvarum as the causative organism. The patient was treated with ceftriaxone and surgical intervention was deferred due to the patient’s complex anatomy. His course was complicated by septic cerebral emboli resulting in cerebrovascular accident. Conclusions This case report highlights C. valvarum, a rare and emerging HACEK group microorganism that warrants consideration in high-risk patients with evidence of subacute infection and disseminated disease. While C. valvarum classically presents as infective endocarditis, extra-cardiac manifestations have also been described. As demonstrated in this case, endograft involvement and osteomyelitis may occur in rare circumstances.
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- 2021
12. How Cattle and Wild Ungulate Use of Riparian Areas Effects Measures of Streambank Disturbance
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Brett B. Roper and W. Carl Saunders
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0106 biological sciences ,Ungulate ,Disturbance (geology) ,STREAMS ,Management, Monitoring, Policy and Law ,01 natural sciences ,Grazing ,Ecosystem ,Nature and Landscape Conservation ,Riparian zone ,geography ,geography.geographical_feature_category ,Ecology ,biology ,business.industry ,04 agricultural and veterinary sciences ,biology.organism_classification ,010601 ecology ,Habitat ,040103 agronomy & agriculture ,0401 agriculture, forestry, and fisheries ,Environmental science ,Animal Science and Zoology ,Livestock ,business - Abstract
Improper management of cattle near streams can negatively affect the processes that support stream and riparian ecosystems. To judge the success of riparian management strategies, public land management agencies often evaluate two metrics of livestock disturbance, stubble height and streambank alteration. There are concerns associated with how well these disturbance metrics reflect livestock use and incorporate additional effects due to wild ungulates. We sought to address these questions in 39 riparian areas by using time-lapse cameras to estimate ungulate use and then measuring near stream ungulate disturbance in these same reaches. We found daytime measures of livestock use were related to stubble height and streambank alteration. Explaining the variation in the relationship between stubble height and livestock use was improved by incorporating covariates, whereas covariates did little to improve our understanding of streambank alteration. This suggests greater flexibility in how different stream reaches are managed when stubble height is the guideline. As streambank alteration was explained solely by ungulate use, the simplest way to reduce disturbance was to reduce use. In most stream reaches, the additive presence of wild ungulates was minimal but sufficient to be included in the best models describing the effects of ungulate disturbance. On most days, no cattle were seen in the evaluated riparian reaches. Although large groups of cattle (> 20 individuals) were occasionally observed within riparian areas, they generally occurred in small groups of one to four individuals. Across the riparian reaches we evaluated, cattle presence and density were generally low enough that metrics of livestock disturbance suggested little risk to stream conditions important to aquatic biota. However, there were some riparian areas where cattle stayed too long or occurred in large enough numbers that their use along the streambanks could negatively affect stream habitat conditions.
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- 2021
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13. Quantification of organic aerosol and brown carbon evolution in fresh wildfire plumes
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Lu Hu, Yingjie Shen, Qiaoyun Peng, Frank Flocke, Matson A. Pothier, Emily V. Fischer, Samuel R. Hall, Sonia M. Kreidenweis, R. P. Pokhrel, Joel A. Thornton, Ben H. Lee, Teresa Campos, Wade Permar, Xuan Zhang, Delphine K. Farmer, Shane M. Murphy, Carley D. Fredrickson, Lauren A. Garofalo, Kirk Ullmann, and Brett B. Palm
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Aerosols ,Smoke ,Air Pollutants ,Daytime ,Multidisciplinary ,Particle composition ,010504 meteorology & atmospheric sciences ,010501 environmental sciences ,Particulates ,01 natural sciences ,Carbon ,United States ,Wildfires ,Plume ,Trace gas ,Aerosol ,13. Climate action ,Environmental chemistry ,Physical Sciences ,Environmental science ,Particulate Matter ,Brown carbon ,Environmental Monitoring ,0105 earth and related environmental sciences - Abstract
The evolution of organic aerosol (OA) and brown carbon (BrC) in wildfire plumes, including the relative contributions of primary versus secondary sources, has been uncertain in part because of limited knowledge of the precursor emissions and the chemical environment of smoke plumes. We made airborne measurements of a suite of reactive trace gases, particle composition, and optical properties in fresh western US wildfire smoke in July through August 2018. We use these observations to quantify primary versus secondary sources of biomass-burning OA (BBPOA versus BBSOA) and BrC in wildfire plumes. When a daytime wildfire plume dilutes by a factor of 5 to 10, we estimate that up to one-third of the primary OA has evaporated and subsequently reacted to form BBSOA with near unit yield. The reactions of measured BBSOA precursors contribute only 13 ± 3% of the total BBSOA source, with evaporated BBPOA comprising the rest. We find that oxidation of phenolic compounds contributes the majority of BBSOA from emitted vapors. The corresponding particulate nitrophenolic compounds are estimated to explain 29 ± 15% of average BrC light absorption at 405 nm (BrC Abs(405)) measured in the first few hours of plume evolution, despite accounting for just 4 ± 2% of average OA mass. These measurements provide quantitative constraints on the role of dilution-driven evaporation of OA and subsequent radical-driven oxidation on the fate of biomass-burning OA and BrC in daytime wildfire plumes and point to the need to understand how processing of nighttime emissions differs.
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- 2020
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14. Estimating the Discard Mortality of Atlantic Cod in the Southern Gulf of Maine Commercial Lobster Fishery
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W. Y. Koh, James A. Sulikowski, Brooke N. Anderson, John W. Mandelman, Hugues P. Benoît, Micah J. Dean, E. W. Hutchins, Joseph A. Langan, Brett B. Sweezey, and Connor W. Capizzano
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Fishery ,Ecology ,biology ,Environmental science ,Management, Monitoring, Policy and Law ,Aquatic Science ,Atlantic cod ,biology.organism_classification ,Ecology, Evolution, Behavior and Systematics - Published
- 2020
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15. Effects of fatigue on attention and vigilance as measured with a modified attention network test
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Austin Hurst, Raymond M. Klein, and Brett B. T. Feltmate
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medicine.medical_specialty ,General Neuroscience ,media_common.quotation_subject ,05 social sciences ,Psychomotor vigilance task ,Audiology ,Time on task ,050105 experimental psychology ,Executive Function ,03 medical and health sciences ,0302 clinical medicine ,Attention network ,Reaction Time ,medicine ,Humans ,0501 psychology and cognitive sciences ,Attentional network ,Wakefulness ,Psychology ,Fatigue ,Psychomotor Performance ,030217 neurology & neurosurgery ,Vigilance (psychology) ,media_common - Abstract
As part of a larger study on the effects of fatigue on various attentional and behavioural measures, we had participants complete a modified version of Luna et al.'s (J Neurosci Methods 306:77-87, Luna et al., J Neurosci Methods 306:77-87, 2018) ANTI-Vea task (mANTI-Vea) at the beginning and end (pre/post) of each of two 8-h testing sessions. Between these administrations of the mANTI-Vea our participants spent ~ 6 h performing an intervening task. Our intent in this project was two-fold: first, to replicate the pattern of effects reported in Luna et al.'s original presentation of the ANTI-Vea; second, to assay the impact of fatigue on vigilance and attention by observing shifts in mANTI-Vea performance as a function of time on task and before versus after the intervening task. With time-on-task (the mANTI-Vea is divided into six sub-blocks) we observed that participants became increasingly conservative in their biases to respond towards infrequent targets, showed a decline in sensitivity, and lapsed in responding in the psychomotor vigilance task with greater frequency. In the pre/post comparison, we observed an increase in the proportion of lapses, but not in participants' response biases. Attentional network scores were found to be somewhat insensitive to our fatigue manipulations; the effect of time-on-task was only significant for orienting scores on RT, and our pre/post comparison was only significant for RT derived executive functioning scores.
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- 2020
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16. Mentoring Relates to Job Satisfaction for Fish Biologists: A Longitudinal Study of the USDA Forest Service
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Brooke E. Penaluna, Brett B. Roper, John D. Rothlisberger, Lee K. Cerveny, Dan Shively, and Shelly Witt
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Service (business) ,Longitudinal study ,business.industry ,%22">Fish ,Job satisfaction ,Sociology ,Aquatic Science ,Marketing ,business ,Coaching ,Nature and Landscape Conservation ,Career development - Published
- 2020
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17. Not for the Faint of Heart
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Brett B. Yarusi, Vikrant S. Jagadeesan, and Daniel Schimmel
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Adult ,Cardiac Catheterization ,medicine.medical_specialty ,Pregnancy Complications, Cardiovascular ,MEDLINE ,Embolectomy ,Syncope ,Electrocardiography ,Extracorporeal Membrane Oxygenation ,Pregnancy ,Physiology (medical) ,Internal medicine ,medicine ,Humans ,Anemia, Iron-Deficiency ,biology ,business.industry ,Troponin I ,Syncope (genus) ,Heparin, Low-Molecular-Weight ,biology.organism_classification ,medicine.disease ,Heart Arrest ,Tachycardia, Sinus ,Dyspnea ,Embolism ,Echocardiography ,Cardiology ,Female ,Emergencies ,Pulmonary Embolism ,Tomography, X-Ray Computed ,Cardiology and Cardiovascular Medicine ,business ,Biomarkers - Published
- 2020
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18. Influence of topographic, geomorphic, and hydrologic variables on beaver dam height and persistence in the intermountain western United States
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Brett B. Roper, Joseph M. Wheaton, Philip Bailey, Nicolaas Bouwes, and Konrad Hafen
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Hydrology ,Beaver ,biology ,biology.animal ,Geography, Planning and Development ,Earth and Planetary Sciences (miscellaneous) ,Environmental science ,Beaver dam ,Persistence (discontinuity) ,Stream restoration ,Earth-Surface Processes - Published
- 2020
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19. HONO Emissions from Western U.S. Wildfires Provide Dominant Radical Source in Fresh Wildfire Smoke
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Kirk Ullmann, Brett B. Palm, Lu Hu, Ben H. Lee, Catherine Wielgasz, Ilana B. Pollack, Teresa Campos, Rebecca S. Hornbrook, Frank Flocke, Qiaoyun Peng, Kira E. Melander, Emily V. Fischer, Samuel R. Hall, Jakob Lindaas, Eric C. Apel, Andrew J. Weinheimer, Denise D. Montzka, Timothy H. Bertram, Alan J. Hills, Wade Permar, and Joel A. Thornton
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Aerosols ,Smoke ,Air Pollutants ,Nitrous acid ,Nitrous Acid ,General Chemistry ,010501 environmental sciences ,01 natural sciences ,Wildfires ,chemistry.chemical_compound ,chemistry ,Environmental chemistry ,Environmental Chemistry ,Environmental science ,0105 earth and related environmental sciences - Abstract
Wildfires are an important source of nitrous acid (HONO), a photolabile radical precursor, yet in situ measurements and quantification of primary HONO emissions from open wildfires have been scarce. We present airborne observations of HONO within wildfire plumes sampled during the Western Wildfire Experiment for Cloud chemistry, Aerosol absorption and Nitrogen (WE-CAN) campaign. ΔHONO/ΔCO close to the fire locations ranged from 0.7 to 17 pptv ppbv
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- 2020
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20. Bycatch in a Commercial Lobster Fishery: Effects on Two Benthic Predators, Sea Raven and Longhorn Sculpin
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Brett B. Sweezey, John W. Mandelman, James A. Sulikowski, David B. Rudders, Amelia M. Weissman, and Brooke N. Anderson
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Bycatch ,Fishery ,biology ,Benthic zone ,Sculpin ,Aquatic Science ,biology.organism_classification ,Sea raven ,Ecology, Evolution, Behavior and Systematics ,Predation - Published
- 2020
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21. The Stability and Collapse of Lava Domes: Insight From Photogrammetry and Slope Stability Models Applied to Sinabung Volcano (Indonesia)
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Brett B. Carr, Einat Lev, Loÿc Vanderkluysen, Danielle Moyer, Gayatri Indah Marliyani, and Amanda B. Clarke
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General Earth and Planetary Sciences - Abstract
Lava domes form by the effusive eruption of high-viscosity lava and are inherently unstable and prone to collapse, representing a significant volcanic hazard. Many processes contribute to instability in lava domes and can generally be grouped into two categories: active and passive. Active collapses are driven directly by lava effusion. In contrast, passive collapses are not correlated with effusion rate, and thus represent a hazard that is more difficult to assess and forecast. We demonstrate a new workflow for assessing and forecasting passive dome collapse by examining a case study at Sinabung Volcano (North Sumatra, Indonesia). We captured visual images from the ground in 2014 and from unoccupied aerial systems (UAS) in 2018 and used structure-from-motion photogrammetry to generate digital elevation models (DEMs) of Sinabung’s evolving lava dome. By comparing our DEMs to a pre-eruption DEM, we estimate volume changes associated with the eruption. As of June 2018, the total erupted volume since the eruption began is 162 × 106 m3. Between 2014 and 2018, 10 × 106 m3 of material collapsed from the lava flow due to passive processes. We evaluate lava dome stability using the Scoops3D numerical model and the DEMs. We assess the passive collapse hazard and analyze the effect of lava material properties on dome stability. Scoops3D is able to hindcast the location and volume of passive collapses at Sinabung that occurred during 2014 and 2015, and we use the same material properties to demonstrate that significant portions of the erupted lava potentially remain unstable and prone to collapse as of late 2018, despite a pause in effusive activity earlier that year. This workflow offers a means of quantitatively assessing passive collapse hazards at active or recently active volcanoes.
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- 2022
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22. Fragmentation inside proton-transfer-reaction-based mass spectrometers limits the detection of ROOR and ROOH peroxides
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Haiyan Li, Thomas Golin Almeida, Yuanyuan Luo, Jian Zhao, Brett B. Palm, Christopher D. Daub, Wei Huang, Claudia Mohr, Jordan E. Krechmer, Theo Kurtén, Mikael Ehn, Institute for Atmospheric and Earth System Research (INAR), and Department of Chemistry
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Atmospheric Science ,MONOTERPENE ,SULFURIC-ACID ,CHEMISTRY ,CHEMICAL-IONIZATION ,TOF ,116 Chemical sciences ,RO2 RADICALS ,CYCLOHEXENE OZONOLYSIS ,VOC EMISSIONS ,ENERGY-TRANSFER ,PRODUCTS - Abstract
Proton transfer reaction (PTR) is a commonly applied ionization technique for mass spectrometers, in which hydronium ions (H3O+) transfer a proton to analytes with higher proton affinities than the water molecule. This method has most commonly been used to quantify volatile hydrocarbons, but later-generation PTR instruments have been designed for better throughput of less volatile species, allowing detection of more functionalized molecules as well. For example, the recently developed Vocus PTR time-of-flight mass spectrometer (PTR-TOF) has been shown to agree well with an iodide-adduct-based chemical ionization mass spectrometer (CIMS) for products with 3–5 O atoms from oxidation of monoterpenes (C10H16). However, while several different types of CIMS instruments (including those using iodide) detect abundant signals also at “dimeric” species, believed to be primarily ROOR peroxides, no such signals have been observed in the Vocus PTR even though these compounds fulfil the condition of having higher proton affinity than water. More traditional PTR instruments have been limited to volatile molecules as the inlets have not been designed for transmission of easily condensable species. Some newer instruments, like the Vocus PTR, have overcome this limitation but are still not able to detect the full range of functionalized products, suggesting that other limitations need to be considered. One such limitation, well-documented in PTR literature, is the tendency of protonation to lead to fragmentation of some analytes. In this work, we evaluate the potential for PTR to detect dimers and the most oxygenated compounds as these have been shown to be crucial for forming atmospheric aerosol particles. We studied the detection of dimers using a Vocus PTR-TOF in laboratory experiments, as well as through quantum chemical calculations. Only noisy signals of potential dimers were observed during experiments on the ozonolysis of the monoterpene α-pinene, while a few small signals of dimeric compounds were detected during the ozonolysis of cyclohexene. During the latter experiments, we also tested varying the pressures and electric fields in the ionization region of the Vocus PTR-TOF, finding that only small improvements were possible in the relative dimer contributions. Calculations for model ROOR and ROOH systems showed that most of these peroxides should fragment partially following protonation. With the inclusion of additional energy from the ion–molecule collisions driven by the electric fields in the ionization source, computational results suggest substantial or nearly complete fragmentation of dimers. Our study thus suggests that while the improved versions of PTR-based mass spectrometers are very powerful tools for measuring hydrocarbons and their moderately oxidized products, other types of CIMS are likely more suitable for the detection of ROOR and ROOH species.
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- 2022
23. Combined Coronary Orbital Atherectomy and Intravascular Lithotripsy for the Treatment of Severely Calcified Coronary Stenoses: The First Case Series
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Brett B, Yarusi, Vikrant S, Jagadeesan, Saad, Hussain, Arif, Jivan, Ashley, Tesch, James D, Flaherty, Daniel R, Schimmel, and Keith H, Benzuly
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Atherectomy, Coronary ,Atherectomy ,Percutaneous Coronary Intervention ,Treatment Outcome ,Lithotripsy ,Coronary Stenosis ,Myocardial Infarction ,Humans ,Drug-Eluting Stents ,Constriction, Pathologic ,Coronary Artery Disease ,Coronary Angiography ,Vascular Calcification - Abstract
Severely calcified coronary stenoses remain a significant challenge during contemporary percutaneous coronary intervention (PCI), often requiring advanced therapies to circumvent suboptimal lesion preparation and major adverse cardiac events (MACEs). Recent reports suggest combined coronary atherectomy and intravascular lithotripsy (IVL) may achieve superior preparation of severely calcified coronary stenoses during PCI. We sought to evaluate the safety and utility of combined orbital atherectomy (OA) and IVL for the modification of coronary artery calcification (CAC) prior to drug-eluting stent (DES) implantation in PCI.We performed a retrospective review of all patients who underwent coronary OA and IVL within a single PCI procedure at our institution. The primary outcome was procedural success, defined as successful DES implantation with a residual percent diameter stenosis of30% and Thrombolysis in Myocardial Infarction (TIMI) 3 flow following PCI without occurrence of in-hospital MACE (cardiac death, myocardial infarction, or target-vessel revascularization). MACE was additionally assessed at 30 days post intervention.Eight patients underwent combined coronary OA and IVL within a single PCI procedure. The mean percent diameter stenosis prior to intervention was 80.5 ± 8.3%, with a mean calcific arc of 338 ± 42°. Procedural success was achieved in 7 of 8 cases (87.5%). Both in-hospital and 30-day MACE rates were 0%.We report the safe and effective use of combined coronary OA and IVL for the preparation of severely calcified coronary stenoses during PCI. Through their distinct yet complementary mechanisms of action, the combined use of these therapies may achieve superior preparation of severely calcified coronary stenoses during PCI.
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- 2022
24. Cortisol and testosterone concentrations during the prenatal and postpartum period forecast later caregiving quality in mothers and fathers
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Beijers, R., Breugelmans, S., Brett, B., Willemsen, Y., Bos, P.A., and De Weerth, C.
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Male ,endocrine system ,Hydrocortisone ,Endocrine and Autonomic Systems ,Postpartum Period ,Stress-related disorders Donders Center for Medical Neuroscience [Radboudumc 13] ,Infant ,Mothers ,Social Development ,Fathers ,Behavioral Neuroscience ,All institutes and research themes of the Radboud University Medical Center ,Endocrinology ,Pregnancy ,Child, Preschool ,Humans ,Female ,Testosterone ,Child ,hormones, hormone substitutes, and hormone antagonists - Abstract
Contains fulltext : 250236.pdf (Publisher’s version ) (Open Access) Given that parental caregiving quality affects child development from birth onwards, it is important to detect parents who are at risk for low-quality caregiving as early as possible, preferably before or soon after birth. This study investigated whether cortisol (CORT) and testosterone (T) measured during the last trimester of pregnancy and six weeks postpartum were associated with observed caregiving quality at child age 3 in mothers (N = 63) and fathers (N = 45). CORT and T were measured during an interaction with a simulator infant (pregnancy) and their own infant (postpartum). In mothers, no associations were found with CORT and T during pregnancy, but higher postpartum CORT during a mother-infant interaction was related to higher caregiving quality during toddlerhood. In fathers, the association between T during pregnancy and caregiving quality in toddlerhood was more negative for fathers with low CORT. In contrast to mothers, higher postpartum CORT in fathers was associated with lower caregiving quality in toddlerhood. These findings proved robust after applying the Benjamini–Hochberg procedure to control for false discovery rate. Our findings indicate that CORT and T during the perinatal period can forecast caregiving quality in both mothers and fathers. Moreover, our results provided evidence for the dual-hormone hypothesis, but only in fathers. These findings contribute to our growing understanding on how endocrine measures explain individual differences in caregiving quality in mothers and fathers. 12 p.
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- 2022
25. Assessment of the impact of the COVID-19 pandemic on health services use
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Kimberly J. Johnson, Charles W. Goss, Jeannette Jackson Thompson, Anne M. Trolard, Brett B. Maricque, Victoria Anwuri, Rachel Cohen, Kate Donaldson, and Elvin Geng
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Health Policy ,Public Health, Environmental and Occupational Health - Abstract
The coronavirus disease of 2019 (COVID-19) pandemic declared by the World Health Organization on March 11, 2020 impacted healthcare services with provider and patient cancellations, delays, and patient avoidance or delay of emergency department or urgent care. Limited data exist on the population proportion affected by delayed healthcare, which is important for future healthcare planning efforts. Our objective was to evaluate the impact of the COVID-19 pandemic on healthcare service cancellations or delays and delays/avoidance of emergency/urgent care overall and by population characteristics.This was a cross-sectional study.Our sample (n = 2314) was assembled through a phone survey from 8/12/2020-10/27/2020 among non-institutionalized St. Louis County, Missouri, USA residents ≥18 years. We asked about provider and patient-initiated cancellations or delays of appointments and pandemic-associated delays/avoidance of emergency/urgent care overall and by participant characteristics. We calculated weighted prevalence estimates by select resident characteristics.Healthcare services cancellations or delays affected ∼54% (95% CI 50.6%-57.1%) of residents with dental (31.1%, 95% CI 28.1%-34.0%) and primary care (22.1%, 95% CI 19.5%-24.6%) being most common. The highest prevalences were among those who were White, ≥65 years old, female, in fair/poor health, who had health insurance, and who had ≥1 medical condition. Delayed or avoided emergency/urgent care impacted ∼23% (95% CI 19.9%-25.4%) of residents with a higher prevalence in females than males.Healthcare use disruptions impacted a substantial proportion of residents. Future healthcare planning efforts should consider these data to minimize potential morbidity and mortality from delayed care.
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- 2021
26. Novel Analysis to Quantify Plume Crosswind Heterogeneity Applied to Biomass Burning Smoke
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Katherine Hayden, Siyuan Wang, Ann M. Middlebrook, Z. Decker, Kanako Sekimoto, Andrew J. Weinheimer, Jakob Lindaas, Pamela S. Rickly, Kirk Ullmann, Brett B. Palm, Alessandro Franchin, J. Andrew Neuman, Steven S. Brown, Pedro Campuzano Jost, Joshua P. DiGangi, Michael A. Robinson, Demetrios Pagonis, Christopher D. Holmes, Georgios I. Gkatzelis, Thomas B. Ryerson, Matthew M. Coggon, Rebecca A. Washenfelder, Frank Flocke, Glenn S. Diskin, Ilann Bourgeois, G. S. Tyndall, Carley D. Fredrickson, Felix Piel, Jose L. Jimenez, Patrick R. Veres, Jeff Peischl, John B. Nowak, L. Gregory Huey, Carsten Warneke, Samuel R. Hall, Denise D. Montzka, Caroline C. Womack, Andrew W. Rollins, Hannah Halliday, Armin Wisthaler, Young Ro Lee, and Joel A. Thornton
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Smoke ,Aerosols ,Nitrous acid ,Air Pollutants ,010504 meteorology & atmospheric sciences ,General Chemistry ,010501 environmental sciences ,Atmospheric sciences ,01 natural sciences ,humanities ,Aerosol ,Plume ,chemistry.chemical_compound ,chemistry ,13. Climate action ,TRACER ,Air Pollution ,Environmental Chemistry ,Environmental science ,Biomass ,Biomass burning ,Air quality index ,0105 earth and related environmental sciences ,Crosswind - Abstract
We present a novel method, the Gaussian observational model for edge to center heterogeneity (GOMECH), to quantify the horizontal chemical structure of plumes. GOMECH fits observations of short-lived emissions or products against a long-lived tracer (e.g., CO) to provide relative metrics for the plume width (wi/wCO) and center (bi/wCO). To validate GOMECH, we investigate OH and NO3 oxidation processes in smoke plumes sampled during FIREX-AQ (Fire Influence on Regional to Global Environments and Air Quality, a 2019 wildfire smoke study). An analysis of 430 crosswind transects demonstrates that nitrous acid (HONO), a primary source of OH, is narrower than CO (wHONO/wCO = 0.73-0.84 ± 0.01) and maleic anhydride (an OH oxidation product) is enhanced on plume edges (wmaleicanhydride/wCO = 1.06-1.12 ± 0.01). By contrast, NO3 production [P(NO3)] occurs mainly at the plume center (wP(NO3)/wCO = 0.91-1.00 ± 0.01). Phenolic emissions, highly reactive to OH and NO3, are narrower than CO (wphenol/wCO = 0.96 ± 0.03, wcatechol/wCO = 0.91 ± 0.01, and wmethylcatechol/wCO = 0.84 ± 0.01), suggesting that plume edge phenolic losses are the greatest. Yet, nitrophenolic aerosol, their oxidation product, is the greatest at the plume center (wnitrophenolicaerosol/wCO = 0.95 ± 0.02). In a large plume case study, GOMECH suggests that nitrocatechol aerosol is most associated with P(NO3). Last, we corroborate GOMECH with a large eddy simulation model which suggests most (55%) of nitrocatechol is produced through NO3 in our case study.
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- 2021
27. Fragmentation inside PTR-based mass spectrometers limits the detection of ROOR and ROOH peroxides
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Haiyan Li, Theo Kurtén, Wei Huang, Thomas Golin Almeida, Jordan E. Krechmer, Mikael Ehn, Brett B. Palm, Christopher D. Daub, Jian Zhao, Claudia Mohr, and Yuanyuan Luo
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chemistry.chemical_compound ,Chemical ionization ,Hydronium ,chemistry ,Fragmentation (mass spectrometry) ,Ionization ,Proton affinity ,Protonation ,Photochemistry ,Mass spectrometry ,Ion - Abstract
Proton-transfer-reaction (PTR) is a commonly applied ionization technique for mass spectrometers, where hydronium ions (H3O+) transfer a proton to analytes with higher proton affinities than the water molecule. This method has most commonly been used to quantify volatile hydrocarbons, but later generation PTR-instruments have been designed for better throughput of less volatile species, allowing detection of more functionalized molecules as well. For example, the recently developed Vocus PTR time-of-flight mass spectrometer (PTR-TOF) has been shown to agree well with an iodide adduct based chemical ionization mass spectrometer (CIMS) for products with 3-5 O-atoms from oxidation of monoterpenes (C10H16). However, while several different types of CIMS instruments (including those using iodide) detect abundant signals also at “dimeric” species, believed to be primarily ROOR peroxides, no such signals have been observed in the Vocus PTR, even though these compounds fulfil the condition of having higher proton affinity than water. More traditional PTR instruments have been limited to volatile molecules as the inlets have not been designed for transmission of easily condensable species. Some newer instruments, like the Vocus PTR, have overcome this limitation, but are still not able to detect the full range of functionalized products, suggesting that other limitations need to be considered. One such limitation, well-documented in PTR literature, is the tendency of protonation to lead to fragmentation of some analytes. In this work, we evaluate the potential for PTR to detect dimers and the most oxygenated compounds, as these have been shown to be crucial for forming atmospheric aerosol particles. We studied the detection of dimers using a Vocus PTR-TOF in laboratory experiments as well as through quantum chemical calculations. Only noisy signals of potential dimers were observed during experiments on the ozonolysis of the monoterpene α-pinene, while a few small signals of dimeric compounds were detected during the ozonolysis of cyclohexene. During the latter experiments, we also tested varying the pressures and electric fields in the ionization region of the Vocus PTR-TOF, finding that only small improvements were possible in the relative dimer contributions. Calculations for model ROOR and ROOH systems showed that most of these peroxides should fragment partially following protonation. With inclusion of additional energy from the ion-molecule collisions driven by the electric fields in the ionization source, computational results suggest substantial or nearly complete fragmentation of dimers. Our study thus suggests that while the improved versions of PTR-based mass spectrometers are very powerful tools for measuring hydrocarbons and their moderately oxidized products, other types of CIMS are likely more suitable for the detection of ROOR and ROOH species.
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- 2021
28. Supplementary material to 'Fragmentation inside PTR-based mass spectrometers limits the detection of ROOR and ROOH peroxides'
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Haiyan Li, Thomas Golin Almeida, Yuanyuan Luo, Jian Zhao, Brett B. Palm, Christopher D. Daub, Wei Huang, Claudia Mohr, Jordan E. Krechmer, Theo Kurtén, and Mikael Ehn
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- 2021
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29. SARS-CoV-2 active infection prevalence and seroprevalence in the adult population of St. Louis County
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Charles W. Goss, Brett B. Maricque, Victoria V. Anwuri, Rachel E. Cohen, Kate Donaldson, Kimberly J. Johnson, William G. Powderly, Kenneth B. Schechtman, Spring Schmidt, Jeannette Jackson Thompson, Anne M. Trolard, Jinli Wang, and Elvin H. Geng
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Adult ,Epidemiology ,SARS-CoV-2 ,Seroepidemiologic Studies ,Immunoglobulin G ,Prevalence ,COVID-19 ,Humans ,Antibodies, Viral - Abstract
The true prevalence of COVID-19 is difficult to estimate due to the absence of random population-based testing. To estimate current and past COVID-19 infection prevalence in a large urban area, we conducted a population-based survey in St. Louis County, Missouri.The population-based survey of active infection (PCR) and seroprevalence (IgG antibodies) of adults (≥18 years) was conducted through random-digit dialing and targeted sampling of St. Louis County residents with oversampling of Black residents. Infection prevalence of residents was estimated using design-based and raking weighting.Between August 17 and October 24, 2020, 1245 residents completed a survey and underwent PCR testing; 1073 residents completed a survey and underwent PCR and IgG testing or self-reported results. Weighted prevalence estimates of residents with active infection were 1.9% (95% CI, 0.4%-3.3%) and 5.6% were ever infected (95% CI, 3.3%-8.0%). Overall infection hospitalization and fatality ratios were 4.9% and 1.4%, respectively.Through October 2020, the percentage of residents that had ever been infected was relatively low. A markedly higher percentage of Black and other minorities compared to White residents were infected with COVID-19. The St. Louis region remained highly vulnerable to widespread infection in late 2020.
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- 2021
30. Supplementary material to 'A Systematic Re-evaluation of Methods for Quantification of Bulk Particle-phase Organic Nitrates Using Real-time Aerosol Mass Spectrometry'
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Douglas A. Day, Pedro Campuzano-Jost, Benjamin A. Nault, Brett B. Palm, Weiwei Hu, Hongyu Guo, Paul J. Wooldridge, Ronald C. Cohen, Kenneth S. Docherty, J. Alex Huffman, Suzane S. de Sá, Scot T. Martin, and Jose L. Jimenez
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- 2021
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31. Is Excisional Biopsy Needed for Pure FEA Diagnosed on a Core Biopsy?
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Marissa Howard-McNatt, Brett B Fowler, Akiko Chiba, Jennifer L Miller-Ocuin, Daniel L Coldren, and Edward A. Levine
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Core needle ,medicine.medical_specialty ,Biopsy ,Breast Neoplasms ,030218 nuclear medicine & medical imaging ,Diagnosis, Differential ,03 medical and health sciences ,0302 clinical medicine ,Flat Epithelial Atypia ,Humans ,Medicine ,Breast ,Neoplasm Staging ,Retrospective Studies ,medicine.diagnostic_test ,business.industry ,Reproducibility of Results ,General Medicine ,Middle Aged ,030220 oncology & carcinogenesis ,Female ,Surgical excision ,Biopsy, Large-Core Needle ,Radiology ,business ,Core biopsy ,Precancerous Conditions - Abstract
Background The management of flat epithelial atypia (FEA) on core needle biopsy remains controversial. The upstaging rates after surgical excision are variable. In this study, we seek to determine the upstaging rate of FEA at our institution. Methods Patients with a diagnosis of FEA were identified from the institution’s pathology database from 2009 to 2018. Patients were included in the study if FEA alone, without atypia or cancer, was identified on core needle biopsy. Patient demographics, imaging, management, and pathology characteristics were obtained. Statistical analysis performed using IBM SPSS 26.0 (Armonk, NY, USA). Results FEA was diagnosed on core needle biopsy in 235 patients from 2009 to December 2018. Forty-eight patients met the inclusion criteria. The majority of patients presented with calcifications on mammogram (n = 21, 64%) with the remainder as masses (n = 6, 18%) or architectural distortion (n = 6, 18%). Of those, 15 (31%) patients declined surgical excision, of which none developed cancer over a mean follow-up of 4.4 years. Of the 33 (69%) patients undergoing excisional biopsy, 17 (52%) confirmed FEA, 11 (33%) had benign findings, and 3 (9%) demonstrated atypical ductal hyperplasia on final pathology. One (3%) case revealed ductal carcinoma in situ (DCIS) and 1 (3%) was upgraded to invasive cancer for an overall upstaging rate of 4% (2/48). After a mean follow-up of 3.4 years, none of the excisional biopsy patients developed invasive breast cancer. Adjuvant therapy was used in the cases of DCIS and invasive cancer; however, chemoprevention with raloxifene or tamoxifen was not chosen by any of the remaining patients. Conclusion In our cohort, expectant management of FEA alone appears to be a safe option as our upstaging rate to DCIS or invasive cancer for FEA diagnosed on core biopsy was only 4%. Our study suggests that close follow-up is a safe and feasible option for pure FEA without a radiographic discordance found on core biopsy.
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- 2020
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32. Beavers alter stream macroinvertebrate communities in north‐eastern Utah
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Brett B. Roper, Susan E. Washko, Trisha B. Atwood, and John Wiley & Sons Ltd.
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0106 biological sciences ,Biomass (ecology) ,Beaver ,River ecosystem ,Castor canadensis ,biology ,Ecology ,010604 marine biology & hydrobiology ,Baetis ,Aquatic Science ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Ecosystem engineer ,ecosystem engineer ,Water Resource Management ,Geography ,Habitat ,biology.animal ,functional feeding group ,Ecosystem ,Species richness ,benthic community ,biodiversity ,Fresh Water Studies - Abstract
Understanding changes in macroinvertebrate communities is important because they play a large role in stream ecosystem functioning, and they are an important food resource for fish. Beaver‐induced changes to stream morphology could alter macroinvertebrate communities, which in turn could affect food webs and ecosystem function. However, studies investigating the effects of North American beaver activities on macroinvertebrates are rare in the inter‐mountain west, an area with high potential for beaver‐assisted restoration. The aim of this study was to quantify differences in the macroinvertebrate community between unaltered segments of streams and within beaver ponds in north‐eastern Utah, U.S.A. We assessed macroinvertebrate species richness, biomass, density, functional feeding group composition, mobility group composition, and macroinvertebrate habitat characteristics to test the hypothesis that macroinvertebrate communities will differ among habitat types (undammed stream segments and beaver ponds) in beaver‐occupied streams. Beaver pond communities significantly differed from lotic reach communities in many ways. Beaver ponds were less diverse with 25% fewer species. Although there was variability among streams, in general, beaver ponds had 75% fewer individuals and 90% lower total macroinvertebrate biomass compared to lotic reaches. Regarding functional feeding groups, beaver ponds contained more engulfers, while lotic reaches contained more scrapers, filterers, and gatherers. For mobility groups, beaver ponds had more sprawlers, while lotic reaches had more clingers. Swimmers were also more prevalent in lotic reaches, although this is probably due to the abundance of Baetis within lotic reaches. More beaver pond taxa were classified as lentic‐dwelling insects, while more lotic reach taxa were categorised as preferring lotic habitats. The creation of ponds by beavers fundamentally altered the macroinvertebrate community in north‐eastern Utah streams. Such changes to stream macroinvertebrate communities suggest that recolonisation of beavers across North America may be altering stream functioning and food webs. Our study highlights the need to further investigate the effects of beaver recolonisation on stream communities.
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- 2019
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33. Performance of a new coaxial ion–molecule reaction region for low-pressure chemical ionization mass spectrometry with reduced instrument wall interactions
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Jose L. Jimenez, Brett B. Palm, Xiaoxi Liu, and Joel A. Thornton
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Atmospheric Science ,Analyte ,Chemical ionization ,Materials science ,010504 meteorology & atmospheric sciences ,lcsh:TA715-787 ,lcsh:Earthwork. Foundations ,010501 environmental sciences ,01 natural sciences ,Molecular physics ,Trace gas ,Ion ,lcsh:Environmental engineering ,Ionization ,Molecule ,Coaxial ,lcsh:TA170-171 ,Volatility (chemistry) ,0105 earth and related environmental sciences - Abstract
Chemical ionization mass spectrometry (CIMS) techniques have become prominent methods for sampling trace gases of relatively low volatility. Such gases are often referred to as being “sticky”, i.e., having measurement artifacts due to interactions between analyte molecules and instrument walls, given their tendency to interact with wall surfaces via absorption or adsorption processes. These surface interactions can impact the precision, accuracy, and detection limits of the measurements. We introduce a low-pressure ion–molecule reaction (IMR) region primarily built for performing iodide-adduct ionization, though other adduct ionization schemes could be employed. The design goals were to improve upon previous low-pressure IMR versions by reducing impacts of wall interactions at low pressure while maintaining sufficient ion–molecule reaction times. Chamber measurements demonstrate that the IMR delay times (i.e., magnitude of wall interactions) for a range of organic molecules spanning 5 orders of magnitude in volatility are 3 to 10 times lower in the new IMR compared to previous versions. Despite these improvements, wall interactions are still present and need to be understood. To that end, we also introduce a conceptual framework for considering instrument wall interactions and a measurement protocol to accurately capture the time dependence of analyte concentrations. This protocol uses short-duration, high-frequency measurements of the total background (i.e., fast zeros) during ambient measurements as well as during calibration factor determinations. This framework and associated terminology applies to any instrument and ionization technique that samples compounds susceptible to wall interactions.
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- 2019
34. Intraoperative aberrometry versus preoperative biometry for intraocular lens power selection in short eyes
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Shruti Sudhakar, Darren C. Hill, Tonya S. King, Ingrid U. Scott, Gautam Mishra, Brett B. Ernst, and Seth M. Pantanelli
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Lenses, Intraocular ,Male ,Optics and Photonics ,Biometry ,Phacoemulsification ,Aberrometry ,Visual Acuity ,Reproducibility of Results ,Middle Aged ,Refraction, Ocular ,Sensory Systems ,Axial Length, Eye ,Intraoperative Period ,Ophthalmology ,Lens Implantation, Intraocular ,Humans ,Female ,Surgery ,Postoperative Period ,Retrospective Studies - Abstract
To compare the accuracy of preoperative biometry-based formulas to intraoperative aberrometry (IA) with respect to predicting refractive outcomes after cataract surgery in short eyes.Private practice and community-based ambulatory surgery center.Retrospective consecutive case series.Eyes with an axial length (AL) shorter than 22.1 mm underwent cataract extraction and intraocular lens (IOL) implantation. The predicted residual refractive error was calculated preoperatively using Hoffer Q, Holladay 2, Haigis, Barrett Universal II, and Hill-RBF formulas and intraoperatively using IA. The postoperative spherical equivalent (SE) was compared with the predicted SE to evaluate the accuracy of each aforementioned method.Fifty-one eyes from 38 patients met criteria to be included in the analysis. Without optimizing the formulas specifically for short eyes, the mean numerical errors (MNEs) associated with Hoffer Q, Holladay 2, Haigis, Barrett Universal II, Hill-RBF, and IA were -0.08 (95% confidence interval [CI], -0.30 to 0.13), -0.14 (95% CI, -0.35 to 0.07), +0.26 (95% CI, 0.05 to 0.47), +0.11 (95% CI, -0.10 to 0.32), +0.07 (95% CI, -0.14 to 0.28), and +0.00 (95% CI, -0.21 to 0.21), respectively (P .001). The proportion of eyes within ±0.5 diopter (D) of the predicted SE were 49.0%, 43.1%, 52.9%, 52.9%, 60.8%, and 58.8%, respectively (P = .06). The prediction outcomes from IA were statistically better than Haigis, but not other formulas. When formula and IA predictions differed by 0.5 D or more, IA's ability to recommend a more emmetropic outcome was no better than chance (50%).Intraoperative aberrometry is not significantly different from the best preoperative biometry-based methods available for IOL power selection in short eyes.
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- 2019
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35. Hyperbaric oxygen for mTBI-associated PCS and PTSD: Pooled analysis of results from Department of Defense and other published studies
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Lindell K. Weaver, Amarnath Vijayarangan, Ashutosh Gupta, Kayla Deru, Brett B. Hart, Donald Hebert, and Steffanie H Wilson
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medicine.medical_specialty ,Traumatic brain injury ,business.industry ,Sham Intervention ,Neuropsychology ,General Medicine ,Rivermead post-concussion symptoms questionnaire ,medicine.disease ,behavioral disciplines and activities ,Clinical trial ,Free recall ,Pooled analysis ,Internal medicine ,medicine ,Verbal memory ,business - Abstract
Background: Some clinical trials report improvement in persistent post-concussive symptoms (PCS) with hyperbaric oxygen (HBO2) following mild traumatic brain injury (mTBI), but questions remain regarding the utility of HBO2 for PCS, the effects of HBO2 on post-traumatic stress disorder (PTSD), and the influences of sham control exposures. Methods: A systematic review and pooled analysis was conducted to summarize available evidence for HBO2 in mTBI-associated PCS ± PTSD. Data aggregated from four Department of Defense (DoD) studies with participant-level data (n=254) were grouped into pooled HBO2 and sham intervention groups. Changes from baseline to post-intervention on PCS, PTSD, and neuropsychological measures were assessed using linear mixed models to evaluate main intervention and intervention-by-baseline PTSD effects. Potential dose-response relationships to oxygen partial pressures were investigated. Intervention effects from three other published studies with summary-level participant data (n=135) were also summarized. Results: Pooled DoD data analyses indicated trends toward improvement favoring HBO2 for PCS (Rivermead Total Score: -2.3, 95% CI [-5.6, 1.0], p=0.18); PTSD (PTSD Checklist Total Score: -2.7, 95% CI [-5.8, 0.4], p=0.09); and significant improvement in verbal memory (CVLT-II Trial 1-5 Free Recall: 3.8; 95% CI [1.0, 6.7], p=0.01). A dose-response trend to increasing oxygen partial pressure was also found, with a greater HBO2 effect in mTBI-associated PTSD suggested. The direction of results was consistent with other published studies. Conclusions: A definitive clinical trial, with an appropriate control group, should be considered to identify the optimal HBO2 dosing regimen for individuals with mTBI-associated PTSD ± PCS.
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- 2019
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36. NanoFab SIMS: High Spatial Resolution Imaging and Analysis Using Inert-Gas Ion Beams
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Fouzia Khanom, Sybren Sijbrandij, Brett B. Lewis, Doug Runt, Alexander Lombardi, Alain Sireuil, John A. Notte, and Christelle Guillermier
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010302 applied physics ,Chemical imaging ,Materials science ,General Computer Science ,Ion beam ,business.industry ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Mass spectrometry ,01 natural sciences ,Secondary electrons ,Ion ,Secondary ion mass spectrometry ,Optics ,0103 physical sciences ,0210 nano-technology ,business ,Image resolution ,Beam (structure) - Abstract
By combining a focused inert-gas ion beam instrument and a custom magnetic-sector mass spectrometer, high spatial resolution imaging and chemical analysis are provided within a single instrument. Sub-nanometer image resolution is achieved by secondary electron (SE) imaging, limited only by the probe-size of the primary beam, while the spatial resolution for chemical mapping obtained via secondary ion mass spectrometry (SIMS) is limited mainly by beam-sample interactions to about 10 nm. This article introduces the background behind this development, describes the instrument and its various operating modes, and presents examples of its applications.
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- 2019
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37. Extended follow-up in a randomized trial of hyperbaric oxygen for persistent post-concussive symptoms
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Lindell K. Weaver, Anne S. Lindblad, Mahesh Minnakanti, Steffanie H Wilson, Susan Churchill, Kayla Deru, and Brett B. Hart
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Selection bias ,medicine.medical_specialty ,Response to intervention ,business.industry ,Traumatic brain injury ,media_common.quotation_subject ,General Medicine ,medicine.disease ,law.invention ,Randomized controlled trial ,Quality of life ,law ,Intervention (counseling) ,Physical therapy ,Medicine ,Anxiety ,medicine.symptom ,business ,Depression (differential diagnoses) ,media_common - Abstract
To date, several Department of Defense (DoD) and civilian studies have evaluated hyperbaric oxygen for mild forms of traumatic brain injury. Prior to the DoD-sponsored "Brain Injury and Mechanisms of Action of Hyperbaric Oxygen for Persistent Post-Concussive Symptoms after Mild Traumatic Brain Injury (mTBI) (BIMA)" trial, none included post-intervention follow-up beyond three to six months. Post-hoc attempts at long-term follow-up were complicated by low participation and potential self-selection bias. BIMA planned for follow-up through 12 months but was amended to add post-concussive and post-traumatic stress disorder, quality of life, pain, depression, anxiety, and alcohol use assessments at 24 and 36 months. A total of 42 of 71 BIMA participants consented to extendedfollow-up, and 40 and 14 completed a 24- or 36-month visit, respectively, representing an overall response rate of 59% and 20%. Participants who completed extended follow-up were similar to the study group that did not in terms of demographics, perceived intervention allocation, and initial response to intervention. There were no significant differences at 24 or 36 months between intervention groups, and group mean scores were near pre-intervention values. This return to baseline could be due to waning treatment effect, selection bias, or participant or perception effects. Though BIMA implemented several participant retention strategies, more frequent participant contact and increased compensation might improve long-term retention in future studies. clinicaltrials.gov Identifier NCT01611194.
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- 2019
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38. Executive summary: Secondary analyses of DoD-sponsored studies examining hyperbaric oxygen for persistent post-concussive symptoms after mild traumatic brain injury
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Susan Churchill, Lindell K. Weaver, Steffanie H Wilson, Anne S. Lindblad, Kayla Deru, and Brett B. Hart
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medicine.medical_specialty ,Executive summary ,Post-Concussive Symptoms ,Traumatic brain injury ,Accident prevention ,business.industry ,Poison control ,General Medicine ,medicine.disease ,nervous system diseases ,Hyperbaric oxygen ,Injury prevention ,Emergency medicine ,medicine ,Stress disorders ,business - Abstract
Traumatic brain injury (TBI) is a major cause of death and disability in the United States (U.S.), with the Centers for Disease Control and Prevention reporting approximately 2.8 million TBI-related emergency department visits, hospitalizations, and deaths in 2012 [1]. For those under 45 years of age, TBI is the number one cause of disability and mortality worldwide [2]. Within military populations TBI remains especially problematic. While the incidence of TBI in the U.S. military peaked in 2011, Department of Defense personnel continue to experience approximately 18,000 new cases each year, with 383,473 total cases between 2000 and the first quarter of 2018 [3]. Eighty-two percent of these injuries were classified as mild TBI (mTBI) [3].
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- 2019
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39. Comparison of treatment recompression tables for neurologic decompression illness in swine model
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W. Rainey Johnson, Nicholas G. Roney, Hanbing Zhou, Geoffrey E. Ciarlone, Brian T. Williams, William T. Green, Richard T. Mahon, Hugh M. Dainer, Brett B. Hart, and Aaron A. Hall
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Decompression ,Oxygen ,Hyperbaric Oxygenation ,Multidisciplinary ,Nitrogen ,Swine ,Diving ,Animals ,Decompression Sickness ,Helium ,Spinal Cord Diseases - Abstract
Background Significant reductions in ambient pressure subject an individual to risk of decompression illness (DCI); with incidence up to 35 per 10,000 dives. In severe cases, the central nervous system is often compromised (>80%), making DCI among the most morbid of diving related injuries. While hyperbaric specialists suggest initiating recompression therapy with either a Treatment Table 6 (TT6) or 6A (TT6A), the optimal initial recompression treatment for severe DCI is unknown. Methods Swine were exposed to an insult dive breathing air at 7.06 ATA (715.35 kPa) for 24 min followed by rapid decompression at a rate of 1.82 ATA/min (184.41 kPa/min). Swine that developed neurologic DCI within 1 hour of surfacing were block randomized to one of four United States Navy Treatment Tables (USN TT): TT6, TT6A-air (21% oxygen, 79% nitrogen), TT6A-nitrox (50% oxygen, 50% nitrogen), and TT6A-heliox (50% oxygen, 50% helium). The primary outcome was the mean number of spinal cord lesions, which was analyzed following cord harvest 24 hours after successful recompression treatment. Secondary outcomes included spinal cord lesion incidence and gross neurologic outcomes based on a pre- and post- modified Tarlov assessment. We compared outcomes among these four groups and between the two treatment profiles (i.e. TT6 and TT6A). Results One-hundred and forty-one swine underwent the insult dive, with 61 swine meeting inclusion criteria (43%). We found no differences in baseline characteristics among the groups. We found no significant differences in functional neurologic outcomes (p = 0.77 and 0.33), spinal cord lesion incidence (p = 0.09 and 0.07), or spinal cord lesion area (p = 0.51 and 0.17) among the four treatment groups or between the two treatment profiles, respectively. While the trends were not statistically significant, animals treated with TT6 had the lowest rates of functional deficits and the fewest spinal cord lesions. Moreover, across all animals, functional neurologic deficit had strong correlation with lesion area pathology (Logistic Regression, p < 0.01, Somers’ D = 0.74). Conclusions TT6 performed as well as the other treatment tables and is the least resource intensive. TT6 is the most appropriate initial treatment for neurologic DCI in swine, among the tables that we compared.
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- 2022
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40. Hyperbaric oxygen for refractory osteomyelitis
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Brett B, Hart
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Adult ,Hyperbaric Oxygenation ,Time Factors ,Patient Selection ,Osteomyelitis ,Combined Modality Therapy ,Anti-Bacterial Agents ,Cohort Studies ,Debridement ,Recurrence ,Chronic Disease ,Animals ,Humans ,Child - Abstract
Refractory osteomyelitis is defined as a chronic osteomyelitis that persists or recurs after appropriate interventions have been performed or where acute osteomyelitis has not responded to accepted management techniques [1]. To date, no randomized clinical trials examining the effects of hyperbaric oxygen (HBO2) therapy on refractory osteomyelitis exist, and the number of new osteomyelitis clinical trials conducted over the past decade has been limited. However, based on a comprehensive review of the scientific literature, the addition of HBO2 therapy to routine surgical and antibiotic treatment of previously refractory osteomyelitis appears to be both safe and ultimately improves infection resolution rates. In most cases, the best clinical results are obtained when HBO2 treatment is administered in conjunction with culture-directed antibiotics and initiated soon after clinically indicated surgical debridement. Where extensive surgical debridement or removal of fixation hardware is relatively contraindicated (e.g., cranial, spinal, sternal, or pediatric osteomyelitis), a trial of culture-directed antibiotics and HBO2 therapy prior to undertaking more than limited surgical interventions provides a reasonable prospect for osteomyelitis cure. HBO2 therapy is ordinarily delivered on a once daily basis, five-seven days per week, for 90-120 minutes using 2.0-3.0 atmospheres absolute (ATA) pressure. Where prompt clinical improvement is seen, the existing regimen of antibiotics and HBO2 therapy should be continued for approximately four to six weeks. Typically, 20-40 HBO2 sessions are required to achieve sustained therapeutic benefit. In contrast, if prompt clinical response is not noted or osteomyelitis recurs after this initial treatment period, then continuation of the current antibiotic and HBO2 treatment regimen is unlikely to be effective. Instead, clinical management strategies should be reassessed and additional surgical debridement and/or modification of antibiotic therapy considered. Subsequent reinstitution of HBO2 therapy will again help maximize the overall chances for treatment success in these persistently refractory patients.
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- 2021
41. Spatially resolved photochemistry impacts emissions estimates in fresh wildfire plumes
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Denise D. Montzka, Qiaoyun Peng, Wade Permar, Frank Flocke, Andrew J. Weinheimer, Emily V. Fischer, Kirk Ullmann, Brett B. Palm, Samuel R. Hall, Lu Hu, Teresa Campos, Geoffrey S. Tyndall, and Joel A. Thornton
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Smoke ,Chemical evolution ,Human health ,Geophysics ,Spatially resolved ,General Earth and Planetary Sciences ,Environmental science ,Biomass burning ,Atmospheric sciences ,Air quality index ,humanities - Abstract
Wildfire emissions affect downwind air quality and human health. Predictions of these impacts using models are limited by uncertainties in emissions and chemical evolution of smoke plumes. Using hi...
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- 2021
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42. Variability and Time of Day Dependence of Ozone Photochemistry in Western Wildfire Plumes
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Michael A. Robinson, Georgios I. Gkatzelis, Carley D. Fredrickson, Brett B. Palm, A. Lamplugh, Andrew J. Weinheimer, Christopher D. Holmes, Carsten Warneke, Rebecca H. Schwantes, Jessica B. Gilman, Geoffrey S. Tyndall, Kanako Sekimoto, Denise M Montzka, Jeff Peischl, Frank Flocke, Paul Van Rooy, Avi Lavi, Ann M. Middlebrook, Z. Decker, Vanessa Selimovic, Matthew M. Coggon, Kelley C. Barsanti, Alessandro Franchin, Steven S. Brown, Brad S. Pierce, and Joel A. Thornton
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Nitrous acid ,Air Pollutants ,Evening ,Photochemistry ,Photodissociation ,Formaldehyde ,General Chemistry ,Atmospheric sciences ,Wildfires ,chemistry.chemical_compound ,Ozone ,chemistry ,Atmospheric chemistry ,Air Pollution ,Mixing ratio ,Environmental Chemistry ,Environmental science ,Air quality index ,NOx ,Environmental Monitoring - Abstract
Understanding the efficiency and variability of photochemical ozone (O3) production from western wildfire plumes is important to accurately estimate their influence on North American air quality. A set of photochemical measurements were made from the NOAA Twin Otter research aircraft as a part of the Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) experiment. We use a zero-dimensional (0-D) box model to investigate the chemistry driving O3 production in modeled plumes. Modeled afternoon plumes reached a maximum O3 mixing ratio of 140 ± 50 ppbv (average ± standard deviation) within 20 ± 10 min of emission compared to 76 ± 12 ppbv in 60 ± 30 min in evening plumes. Afternoon and evening maximum O3 isopleths indicate that plumes were near their peak in NOx efficiency. A radical budget describes the NOx volatile - organic compound (VOC) sensitivities of these plumes. Afternoon plumes displayed a rapid transition from VOC-sensitive to NOx-sensitive chemistry, driven by HOx (=OH + HO2) production from photolysis of nitrous acid (HONO) (48 ± 20% of primary HOx) and formaldehyde (HCHO) (26 ± 9%) emitted directly from the fire. Evening plumes exhibit a slower transition from peak NOx efficiency to VOC-sensitive O3 production caused by a reduction in photolysis rates and fire emissions. HOx production in evening plumes is controlled by HONO photolysis (53 ± 7%), HCHO photolysis (18 ± 9%), and alkene ozonolysis (17 ± 9%).
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- 2021
43. Comparison of Mental Health Symptom Changes from pre-COVID-19 to COVID-19 by Sex or Gender: A Systematic Review and Meta-analysis
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Sanjeev Sockalingam, Brooke Levis, Kexin Li, Jill Boruff, Tiffany Dal Santo, Xiaowen Jiang, Yutong Wang, Sarah Markham, Christine Fahim, Amina Tasleem, Andrea Benedetti, Yin Wu, Ying Sun, Marleine Azar, Ian Thombs-Vite, Gustavo Turecki, Dipika Neupane, Anneke Yao, Branka Agic, Olivia Bonardi, Danielle B. Rice, Ankur Krishnan, Michael S. Martin, Chen He, and Brett B Thombs
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business.industry ,Strictly standardized mean difference ,Meta-analysis ,MEDLINE ,Medicine ,Anxiety ,CINAHL ,medicine.symptom ,business ,Mental health ,Socioeconomic status ,Depression (differential diagnoses) ,Demography - Abstract
ImportanceWomen and gender-diverse individuals have faced disproportionate socioeconomic burden during COVID-19. There have been reports that this has translated into greater negative changes in mental health, but this has been based on cross-sectional research that has not accounted for pre-COVID-19 differences.ObjectiveTo compare mental health symptom changes since pre-COVID-19 by sex or gender.Data SourcesMEDLINE, PsycINFO, CINAHL, EMBASE, Web of Science, China National Knowledge Infrastructure, Wanfang, medRxiv, and Open Science Framework (December 31, 2019 to August 30, 2021).Study SelectionEligible studies compared mental health symptom changes from pre-COVID-19 to COVID-19 by sex or gender.Data Extraction and SynthesisData was extracted by a single reviewer with validation by a second reviewer. Adequacy of study methods and reporting was assessed using an adapted version of the Joanna Briggs Institute Checklist for Prevalence Studies. A restricted maximum-likelihood random-effects meta-analyses was conducted.Main Outcomes and MeasuresAnxiety symptoms, depression symptoms, general mental health, and stress measured continuously or dichotomously.Results12 studies (10 unique cohorts) were included. All compared females or women to males or men; none included gender-diverse individuals. Continuous symptom change differences were not statistically significant for depression (standardized mean difference [SMD]= 0.12, 95% CI -0.09 to 0.33; 4 studies, 4,475 participants; I2=69.0%) and stress (SMD= - 0.10, 95% CI -0.21 to 0.01; 4 studies, 1,533 participants; I2=0.0%), but anxiety (SMD= 0.15, 95% CI 0.07 to 0.22; 4 studies, 4,344 participants; I2=3.0%) and general mental health (SMD= 0.15, 95% CI 0.12 to 0.18; 3 studies, 15,692 participants; I2=0.0%) worsened more among females or women than males or men during COVID-19. There were no significant differences in changes in proportion above a cut-off: anxiety (difference= -0.05, 95% CI -0.20 to 0.11; 1 study, 217 participants), depression (difference= 0.12, 95% CI -0.03 to 0.28; 1 study, 217 participants), general mental health (difference= -0.03, 95% CI -0.09 to 0.04; 3 studies, 18,985 participants; I2=94.0%), stress (difference= 0.04, 95% CI -0.10 to 0.17; 1 study, 217 participants).Conclusion and RelevanceMental health outcomes did not differ or were worse by amounts below thresholds for clinical significance for women compared to men.RegistrationPROSPERO (CRD42020179703).KEY MESSAGESQuestionDid mental health symptoms worsen more for females or women than males or men in COVID-19?FindingsWe reviewed almost 65,000 citations and identified 12 studies that provided data to directly compare mental health symptom changes from pre-COVID-19 to during COVID-19 for females or women versus males or men. Statistically significant, but small, sex- or gender-based differences were found in 2 of 8 mental health outcomes.MeaningMental health changes among females or women were not significantly different from males or men for most outcomes, and differences that were identified were small and less than minimally important difference thresholds.
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- 2021
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44. Emissions of Trace Organic Gases From Western U.S. Wildfires Based on WE‐CAN Aircraft Measurements
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Catherine Wielgasz, Ezra J. T. Levin, Qiaoyun Peng, Alan J. Hills, Brett B. Palm, Amy P. Sullivan, Wade Permar, Lu Hu, Vanessa Selimovic, Rebecca S. Hornbrook, Jeffrey L. Collett, Frank Flocke, Lauren A. Garofalo, Sonia M. Kreidenweis, Delphine K. Farmer, Emily V. Fischer, Barkley C. Sive, Joel A. Thornton, Yong Zhou, Robert J. Yokelson, Qian Wang, I-Ting Ku, Teresa Campos, Paul J. DeMott, and Eric C. Apel
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Trace (semiology) ,Atmospheric Science ,Ptr tof ms ,Geophysics ,Space and Planetary Science ,Organic gases ,Environmental chemistry ,Earth and Planetary Sciences (miscellaneous) ,Environmental science - Published
- 2021
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45. Empirical Insights Into the Fate of Ammonia in Western U.S. Wildfire Smoke Plumes
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Qiaoyun Peng, Lu Hu, Joel A. Thornton, Catherine Wielgasz, Rebecca S. Hornbrook, Emily V. Fischer, Frank Flocke, Julieta F. Juncosa Calahorrano, Brett B. Palm, Ilana B. Pollack, Amy P. Sullivan, Alan J. Hills, Wade Permar, Jeffrey L. Collett, Jakob Lindaas, Lauren A. Garofalo, Delphine K. Farmer, Jeffrey R. Pierce, Andrew J. Weinheimer, Katelyn O'Dell, Geoffrey S. Tyndall, Sonia M. Kreidenweis, Denise D. Montzka, Teresa Campos, Matson A. Pothier, and Eric C. Apel
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Smoke ,Atmospheric Science ,Ammonia ,chemistry.chemical_compound ,Geophysics ,chemistry ,Reactive nitrogen ,Space and Planetary Science ,Environmental chemistry ,Earth and Planetary Sciences (miscellaneous) ,Environmental science - Published
- 2021
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46. Chemical transport models often underestimate inorganic aerosol acidity in remote regions of the atmosphere
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Paul O. Wennberg, Huisheng Bian, Donald R. Blake, Glenn S. Diskin, Douglas A. Day, Duseong S. Jo, Jeffrey R. Pierce, Roya Bahreini, Joseph M. Katich, John D. Crounse, Jason C. Schroder, Hannah M. Allen, Joel A. Thornton, Alma Hodzic, Pedro Campuzano-Jost, Jose L. Jimenez, A. Kupc, John B. Nowak, Mian Chin, Felipe D. Lopez-Hilfiker, Kostas Tsigaridis, Michael J. Cubison, John K. Kodros, Simon L. Clegg, Weiwei Hu, Michelle J. Kim, Benjamin A. Nault, Christina Williamson, Peter F. DeCarlo, Gregory P. Schill, Peter R. Colarco, Eric Scheuer, Brett B. Palm, Eloise A. Marais, J. Andrew Neuman, Ann M. Middlebrook, Fabien Paulot, and Jack E. Dibb
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Physicochemical Processes ,Atmospheric chemistry ,010504 meteorology & atmospheric sciences ,Radiative cooling ,Lead (sea ice) ,010501 environmental sciences ,Atmospheric sciences ,01 natural sciences ,Aerosol ,Atmosphere ,chemistry.chemical_compound ,Nitrate ,chemistry ,Environmental chemistry ,General Earth and Planetary Sciences ,Environmental science ,Ammonium ,Sulfate ,Climate and Earth system modelling ,0105 earth and related environmental sciences ,General Environmental Science - Abstract
The inorganic fraction of fine particles affects numerous physicochemical processes in the atmosphere. However, there is large uncertainty in its burden and composition due to limited global measurements. Here, we present observations from eleven different aircraft campaigns from around the globe and investigate how aerosol pH and ammonium balance change from polluted to remote regions, such as over the oceans. Both parameters show increasing acidity with remoteness, at all altitudes, with pH decreasing from about 3 to about −1 and ammonium balance decreasing from almost 1 to nearly 0. We compare these observations against nine widely used chemical transport models and find that the simulations show more scatter (generally R2
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- 2021
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47. Nighttime and Daytime Dark Oxidation Chemistry in Wildfire Plumes: An Observation and Model Analysis of FIREX-AQ Aircraft Data
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Zachary C. J. Decker, Michael A. Robinson, Kelley C. Barsanti, Ilann Bourgeois, Matthew M. Coggon, Joshua P. DiGangi, Glenn S. Diskin, Frank M. Flocke, Alessandro Franchin, Carley D. Fredrickson, Samuel R. Hall, Hannah Halliday, Christopher D. Holmes, L. Gregory Huey, Young Ro Lee, Jakob Lindaas, Ann M. Middlebrook, Denise D. Montzka, Richard H. Moore, J. Andrew Neuman, John B. Nowak, Brett B. Palm, Jeff Peischl, Pamela S. Rickly, Andrew W. Rollins, Thomas B. Ryerson, Rebecca H. Schwantes, Lee Thornhill, Joel A. Thornton, Geoff S. Tyndall, Kirk Ullmann, Paul Van Rooy, Patrick R. Veres, Andrew J. Weinheimer, Elizabeth Wiggins, Edward Winstead, Caroline Womack, and Steven S. Brown
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Wildfires are increasing in size across the western U.S., leading to increases in human smoke exposure and associated negative health impacts. The impact of biomass burning (BB) smoke, including wildfires, on regional air quality depends on emissions, transport, and chemistry, including oxidation of emitted BB volatile organic compounds (BBVOCs) by the hydroxyl radical (OH), nitrate radical (NO3), and ozone (O3). During the daytime, when light penetrates the plumes, BBVOCs are oxidized mainly by O3 and OH. In contrast, at night, or in optically dense plumes, BBVOCs are oxidized mainly by O3 and NO3. This work focuses on the transition between daytime and nighttime oxidation, which has significant implications for the formation of secondary pollutants and loss of nitrogen oxides (NOx = NO + NO2), and has been understudied. We present wildfire plume observations made during FIREX-AQ (Fire Influence on Regional to Global Environments and Air Quality), a field campaign involving multiple aircraft, ground, satellite, and mobile platforms that took place in the United States in the summer of 2019 to study both wildfire and agricultural burning emissions and atmospheric chemistry. We use observations from two research aircraft, the NASA DC-8 and the NOAA Twin Otter, with a detailed chemical box model, including updated phenolic mechanisms, to analyze smoke sampled during mid-day, sunset, and nighttime. Aircraft observations suggest a range of NO3 production rates (0.1–1.5 ppbv h−1) in plumes transported both mid-day and after dark. Modeled initial instantaneous reactivity toward BBVOCs for NO3, OH, and O3 is 80.1 %, 87.7 %, 99.6 %, respectively. Initial NO3 reactivity is 10–104 times greater than typical values in forested or urban environments and reactions with BBVOCs account for ≥ 98 % of NO3 loss in sunlit plumes (jNO2 up to 4 x 10–3 s–1), while conventional photochemical NO3 loss through reaction with NO and photolysis are minor pathways. Alkenes and furans are mostly oxidized by OH and O3 (11–43 %, 54–88 % for alkenes; 18–55 %, 39–76 %, for furans, respectively), but phenolic oxidation is split between NO3, O3, and OH (26–52 %, 22–43 %, 16–33 %, respectively). Nitrate radical oxidation accounts for 26–52 % of phenolic chemical loss in sunset plumes and in an optically thick plume. Nitrocatechol yields varied between 33 % and 45 %, and NO3 chemistry in BB plumes emitted late in the day is responsible for 72–92 % (84 % in an optically thick mid-day plume) of nitrocatechol formation and controls nitrophenolic formation overall. As a result, overnight nitrophenolic formation pathways account for 56 ± 2 % of NOx loss by sunrise the following day. In all but one overnight plume we model, there is remaining NOx (13 %–57 %) and BBVOCs (8 %–72 %) at sunrise.
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- 2021
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48. The Utility of Peripheral Intravascular Lithotripsy in Calcific Coronary Artery Disease: A Case Series
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Brett B, Yarusi, Vikrant S, Jagadeesan, Arif, Jivan, Erin D, Unger, Lowie M R, Van Assche, Tim S, Provias, James D, Flaherty, Keith H, Benzuly, and Daniel R, Schimmel
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Treatment Outcome ,Lithotripsy ,Humans ,Stents ,Coronary Artery Disease ,Vascular Calcification ,Retrospective Studies - Abstract
Coronary intravascular lithotripsy (IVL) is an emerging therapy for the modification of coronary artery calcification (CAC). Data on its use in several clinical and lesion subsets are limited due to their exclusion from preapproval trials.We performed a retrospective review of patients who were excluded from preapproval trials of coronary IVL and underwent CAC modification with the off-label use of a peripheral IVL system. The primary outcome was a composite of procedural success, defined as residual stenosis10%, and no major adverse cardiac event (MACE), ie, cardiac death, myocardial infarction, or target- vessel revascularization, in hospital and at 30 days.Between June 2019 and April 2020, a total of 9 patients who underwent off-label coronary IVL were identified. Exclusion criteria from preapproval trials included a target lesion within an unprotected left main coronary artery (ULMCA; n = 3) and/or ostial location (n = 5), a target lesion involving in-stent restenosis (n = 3), a second target-vessel lesion with50% stenosis (n = 1), and/or New York Heart Association class III/IV heart failure (n = 5). The primary outcome was achieved in 8 patients. MACE rate was 0% in hospital and at 30 days. For ULMCA lesions (n = 3), residual stenosis was 0% in 2 patients and 10% in 1 patient. For right coronary artery lesions (n = 3), residual stenosis was 0% in 2 patients and 40% in 1 patient. For left anterior descending coronary artery lesions (n = 3), residual stenosis was 0% in all patients.Coronary IVL with a peripheral IVL system may be an effective therapy for CAC modification within ULMCA disease, ostial disease, in-stent restenosis, and New York Heart Association class III/IV heart failure.
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- 2021
49. Daytime Oxidized Reactive Nitrogen Partitioning in Western U.S. Wildfire Smoke Plumes
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Deedee Montzka, Kirk Ullmann, Brett B. Palm, Jeffrey R. Pierce, Delphine K. Farmer, Jeffrey L. Collett, Frank Flocke, Emily V. Fischer, Lauren A. Garofalo, Andrew J. Weinheimer, Teresa Campos, Rebecca S. Hornbrook, Julieta F. Juncosa Calahorrano, Lu Hu, Ilana B. Pollack, Jakob Lindaas, Qiaoyun Peng, Katelyn O'Dell, Joel A. Thornton, Samuel R. Hall, Alan J. Hills, Wade Permar, Matson A. Pothier, Eric C. Apel, and G. S. Tyndall
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Smoke ,Atmospheric Science ,Daytime ,Geophysics ,Reactive nitrogen ,Space and Planetary Science ,Environmental chemistry ,Earth and Planetary Sciences (miscellaneous) ,Environmental science ,Biomass burning - Published
- 2021
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50. Emissions of Reactive Nitrogen From Western U.S. Wildfires During Summer 2018
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Jeffrey L. Collett, Andrew T. Hudak, Lauren A. Garofalo, Qiaoyun Peng, Lu Hu, Denise D. Montzka, Barkley C. Sive, Emily V. Fischer, Catherine Wielgasz, Andrew J. Weinheimer, Wade Permar, Sonia M. Kreidenweis, Delphine K. Farmer, Brett B. Palm, Jakob Lindaas, Joel A. Thornton, Frank Flocke, I-Ting Ku, Geoffrey S. Tyndall, Ilana B. Pollack, Yong Zhou, Matson A. Pothier, Teresa Campos, Amy P. Sullivan, Roger D. Ottmar, and Joseph C. Restaino
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Smoke ,Atmospheric Science ,Ozone ,Volatilisation ,010504 meteorology & atmospheric sciences ,Reactive nitrogen ,chemistry.chemical_element ,Combustion ,Atmospheric sciences ,01 natural sciences ,Nitrogen ,chemistry.chemical_compound ,Geophysics ,Deposition (aerosol physics) ,chemistry ,Space and Planetary Science ,Earth and Planetary Sciences (miscellaneous) ,Environmental science ,NOx ,0105 earth and related environmental sciences - Abstract
Reactive nitrogen (Nr) within smoke plumes plays important roles in the production of ozone, the formation of secondary aerosols, and deposition of fixed N to ecosystems. The Western Wildfire Experiment for Cloud Chemistry, Aerosol Absorption, and Nitrogen (WE-CAN) field campaign sampled smoke from 23 wildfires throughout the western U.S. during summer 2018 using the NSF/NCAR C-130 research aircraft. We empirically estimate Nr normalized excess mixing ratios and emission factors from fires sampled within 80 min of estimated emission and explore variability in the dominant forms of Nr between these fires. We find that reduced N compounds comprise a majority (39%-80%; median = 66%) of total measured reactive nitrogen (ΣNr) emissions. The smoke plumes sampled during WE-CAN feature rapid chemical transformations after emission. As a result, within minutes after emission total measured oxidized nitrogen (ΣNOy) and measured total ΣNHx (NH3 + pNH4) are more robustly correlated with modified combustion efficiency (MCE) than NOx and NH3 by themselves. The ratio of ΣNHx/ΣNOy displays a negative relationship with MCE, consistent with previous studies. A positive relationship with total measured ΣNr suggests that both burn conditions and fuel N content/volatilization differences contribute to the observed variability in the distribution of reduced and oxidized Nr. Additionally, we compare our in situ field estimates of Nr EFs to previous lab and field studies. For similar fuel types, we find ΣNHx EFs are of the same magnitude or larger than lab-based NH3 EF estimates, and ΣNOy EFs are smaller than lab NOx EFs.
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- 2021
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