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Clements N, Arvelo I, Arnold P, Heredia NJ, Hodges UW, Deresinski S, Cook PW, Hamilton KA. Informing Building Strategies to Reduce Infectious Aerosol Transmission Risk by Integrating DNA Aerosol Tracers with Quantitative Microbial Risk Assessment. Environ Sci Technol 2023; 57:5771-5781. [PMID: 37000413 DOI: 10.1021/acs.est.2c08131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Using aerosol-based tracers to estimate risk of infectious aerosol transmission aids in the design of buildings with adequate protection against aerosol transmissible pathogens, such as SARS-CoV-2 and influenza. We propose a method for scaling a SARS-CoV-2 bulk aerosol quantitative microbial risk assessment (QMRA) model for impulse emissions, coughing or sneezing, with aerosolized synthetic DNA tracer concentration measurements. With point-of-emission ratios describing relationships between tracer and respiratory aerosol emission characteristics (i.e., volume and RNA or DNA concentrations) and accounting for aerosolized pathogen loss of infectivity over time, we scale the inhaled pathogen dose and risk of infection with time-integrated tracer concentrations measured with a filter sampler. This tracer-scaled QMRA model is evaluated through scenario testing, comparing the impact of ventilation, occupancy, masking, and layering interventions on infection risk. We apply the tracer-scaled QMRA model to measurement data from an ambulatory care room to estimate the risk reduction resulting from HEPA air cleaner operation. Using DNA tracer measurements to scale a bulk aerosol QMRA model is a relatively simple method of estimating risk in buildings and can be applied to understand the impact of risk mitigation efforts.
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Affiliation(s)
- Nicholas Clements
- Paul M. Rady Department of Mechanical Engineering, University of Colorado at Boulder, Boulder, Colorado 80309, United States
| | - Ilan Arvelo
- SafeTraces, Inc., Pleasanton, California 94588, United States
| | - Phil Arnold
- SafeTraces, Inc., Pleasanton, California 94588, United States
| | | | - Ulrike W Hodges
- SafeTraces, Inc., Pleasanton, California 94588, United States
| | - Stan Deresinski
- Stanford University School of Medicine, Stanford, California 94305, United States
| | - Peter W Cook
- Independent researcher, Atlanta, Georgia 30333, United States
| | - Kerry A Hamilton
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85281, United States
- The Biodesign Institute Center for Environmental Health Engineering, Arizona State University, Tempe, Arizona 85281, United States
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Miller SL, Mukherjee D, Wilson J, Clements N, Steiner C. Implementing a negative pressure isolation space within a skilled nursing facility to control SARS-CoV-2 transmission. Am J Infect Control 2021; 49:438-446. [PMID: 33022331 PMCID: PMC7532347 DOI: 10.1016/j.ajic.2020.09.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 09/22/2020] [Accepted: 09/24/2020] [Indexed: 10/27/2022]
Abstract
BACKGROUND Isolation space must be expanded during pandemics involving airborne transmission. Little to no work has been done to establish optimal design strategies and implementation plans to ease surge capacity and expand isolation capacity over long periods in congregate living facilities. The COVID-19 pandemic has an airborne transmission component and requires isolation, which is difficult to accomplish in skilled nursing facilities. METHODS In this study we designed, implemented, and validated an isolation space at a skilled nursing facility in Lancaster, PA. The overall goal was to minimize disease transmission between residents and staff within the facility. We created an isolation space by modifying an existing HVAC system of the SNF. We measured pressure on-site and performed computational fluid dynamics and Lagrangian particle-based modeling to test containment and possible transmission extent given the isolation space is considered negative rather than individual rooms. RESULTS Pressure data shows the isolation space maintained an average (standard deviation) hourly value of -2.3 Pa (0.12 Pa) pressure differential between it and the external hallway connected to the rest of the facility. No transmission of SARS-CoV-2 between residents isolated to the space occurred, nor did any transmission to the staff or other residents occur. The isolation space was successfully implemented and, as of writing, continues to be operational through the pandemic. CONCLUSION Skilled nursing facilities can be retrofitted to provide negative pressure isolation space in a reasonable time frame and a cost effective manner to minimize airborne disease transmission within that space.
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Affiliation(s)
- Nicholas Clements
- Well Living Lab, Rochester, Minnesota; Mayo Clinic, College of Medicine, Rochester, Minnesota
| | - Matthew J Binnicker
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Véronique L Roger
- Well Living Lab, Rochester, Minnesota; Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota; Department of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
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Torpy F, Clements N, Pollinger M, Dengel A, Mulvihill I, He C, Irga P. Testing the single-pass VOC removal efficiency of an active green wall using methyl ethyl ketone (MEK). Air Qual Atmos Health 2018; 11:163-170. [PMID: 29568336 PMCID: PMC5847137 DOI: 10.1007/s11869-017-0518-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 09/18/2017] [Indexed: 05/22/2023]
Abstract
In recent years, research into the efficacy of indoor air biofiltration mechanisms, notably living green walls, has become more prevalent. Whilst green walls are often utilised within the built environment for their biophilic effects, there is little evidence demonstrating the efficacy of active green wall biofiltration for the removal of volatile organic compounds (VOCs) at concentrations found within an interior environment. The current work describes a novel approach to quantifying the VOC removal effectiveness by an active living green wall, which uses a mechanical system to force air through the substrate and plant foliage. After developing a single-pass efficiency protocol to understand the immediate effects of the system, the active green wall was installed into a 30-m3 chamber representative of a single room and presented with the contaminant 2-butanone (methyl ethyl ketone; MEK), a VOC commonly found in interior environments through its use in textile and plastic manufacture. Chamber inlet levels of MEK remained steady at 33.91 ± 0.541 ppbv. Utilising a forced-air system to draw the contaminated air through a green wall based on a soil-less growing medium containing activated carbon, the combined effects of substrate media and botanical component within the biofiltration system showed statistically significant VOC reduction, averaging 57% single-pass removal efficiency over multiple test procedures. These results indicate a high level of VOC removal efficiency for the active green wall biofilter tested and provide evidence that active biofiltration may aid in reducing exposure to VOCs in the indoor environment.
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Affiliation(s)
- Fraser Torpy
- Plants and Environmental Quality Research Group, School of Life Sciences, Faculty of Science, University of Technology Sydney, Sydney, Australia
| | - Nicholas Clements
- Well Living Lab, Rochester, MN USA
- Delos Labs, Delos, New York, NY USA
- General Internal Medicine, Mayo Clinic, Rochester, MN USA
| | | | - Andy Dengel
- Building Research Establishment, Watford, UK
| | | | - Chuan He
- Well Living Lab, Rochester, MN USA
- Delos Labs, Delos, New York, NY USA
- General Internal Medicine, Mayo Clinic, Rochester, MN USA
| | - Peter Irga
- Plants and Environmental Quality Research Group, School of Life Sciences, Faculty of Science, University of Technology Sydney, Sydney, Australia
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Emerson JB, Keady PB, Clements N, Morgan EE, Awerbuch J, Miller SL, Fierer N. High temporal variability in airborne bacterial diversity and abundance inside single-family residences. Indoor Air 2017; 27:576-586. [PMID: 27743387 DOI: 10.1111/ina.12347] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 10/10/2016] [Indexed: 05/14/2023]
Abstract
Our homes are microbial habitats, and although the amounts and types of bacteria in indoor air have been shown to vary substantially across residences, temporal variability within homes has rarely been characterized. Here, we sought to quantify the temporal variability in the amounts and types of airborne bacteria in homes, and what factors drive this variability. We collected filter samples of indoor and outdoor air in 15 homes over 1 year (approximately eight time points per home, two per season), and we used culture-independent DNA sequencing approaches to characterize bacterial community composition. Significant differences in indoor air community composition were observed both between homes and within each home over time. Indoor and outdoor air community compositions were not significantly correlated, suggesting that indoor and outdoor air communities are decoupled. Indoor air communities from the same home were often just as different at adjacent time points as they were across larger temporal distances, and temporal variation correlated with changes in environmental conditions, including temperature and relative humidity. Although all homes had highly variable indoor air communities, homes with the most temporally variable communities had more stable, lower average microbial loads than homes with less variable communities.
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Affiliation(s)
- J B Emerson
- Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, CO, USA
| | - P B Keady
- Department of Mechanical Engineering, University of Colorado at Boulder, Boulder, CO, USA
| | - N Clements
- Department of Mechanical Engineering, University of Colorado at Boulder, Boulder, CO, USA
| | - E E Morgan
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado at Boulder, Boulder, CO, USA
| | - J Awerbuch
- Department of Mechanical Engineering, University of Colorado at Boulder, Boulder, CO, USA
| | - S L Miller
- Department of Mechanical Engineering, University of Colorado at Boulder, Boulder, CO, USA
| | - N Fierer
- Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, CO, USA
- Department of Ecology and Evolutionary Biology, University of Colorado at Boulder, Boulder, CO, USA
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Kron T, Ungureanu E, Antony R, Hardcastle N, Clements N, Ukath J, Fox C, Lonski P, Wanigaratne D, Haworth A. Patient specific quality control for Stereotactic Ablative Body Radiotherapy (SABR): it takes more than one phantom. ACTA ACUST UNITED AC 2017. [DOI: 10.1088/1742-6596/777/1/012017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Emerson JB, Keady PB, Brewer TE, Clements N, Morgan EE, Awerbuch J, Miller SL, Fierer N. Impacts of flood damage on airborne bacteria and fungi in homes after the 2013 Colorado Front Range flood. Environ Sci Technol 2015; 49:2675-84. [PMID: 25643125 DOI: 10.1021/es503845j] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Flood-damaged homes typically have elevated microbial loads, and their occupants have an increased incidence of allergies, asthma, and other respiratory ailments, yet the microbial communities in these homes remain under-studied. Using culture-independent approaches, we characterized bacterial and fungal communities in homes in Boulder, CO, USA 2-3 months after the historic September, 2013 flooding event. We collected passive air samples from basements in 50 homes (36 flood-damaged, 14 non-flooded), and we sequenced the bacterial 16S rRNA gene (V4-V5 region) and the fungal ITS1 region from these samples for community analyses. Quantitative PCR was used to estimate the abundances of bacteria and fungi in the passive air samples. Results indicate significant differences in bacterial and fungal community composition between flooded and non-flooded homes. Fungal abundances were estimated to be three times higher in flooded, relative to non-flooded homes, but there were no significant differences in bacterial abundances. Penicillium (fungi) and Pseudomonadaceae and Enterobacteriaceae (bacteria) were among the most abundant taxa in flooded homes. Our results suggest that bacterial and fungal communities continue to be affected by flooding, even after relative humidity has returned to baseline levels and remediation has removed any visible evidence of flood damage.
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Affiliation(s)
- Joanne B Emerson
- Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder , 216 UCB, Boulder, Colorado 80309-0216, United States
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Abstract
Airborne particles have been linked to increased mortality and morbidity. As most research has focused on fine particles (PM2.5), the health implications of coarse particles (PM10-2.5) are not well understood. We conducted a systematic review and meta-analysis of associations for short- and long-term PM10-2.5 concentrations with mortality and hospital admissions. Using 23 mortality and 10 hospital admissions studies, we documented suggestive evidence of increased morbidity and mortality in relation to higher short-term PM10-2.5 concentrations, with stronger relationships for respiratory than cardiovascular endpoints. Reported associations were highly heterogeneous, however, especially by geographic region and average PM10-2.5 concentrations. Adjustment for PM2.5 and publication bias resulted in weaker and less precise effect estimates, although positive associations remained for short-term PM10-2.5 concentrations. Inconsistent relationships between effect estimates for PM10-2.5 and correlations between PM10-2.5 and PM2.5 concentrations, however, indicate that PM10-2.5 associations cannot be solely explained by co-exposure to PM2.5. While suggestive evidence was found of increased mortality with long-term PM10-2.5 concentrations, these associations were not robust to control for PM2.5. Additional research is required to better understand sources of heterogeneity of associations between PM10-2.5 and adverse health outcomes.
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Affiliation(s)
- Sara D. Adar
- Department of Epidemiology, University of Michigan, School of Public Health, 1420 Washington Heights – SPHII-5539, Ann Arbor, MI 48109-2029 USA
| | - Paola A. Filigrana
- Department of Epidemiology, University of Michigan, School of Public Health, 1420 Washington Heights – SPHII-5539, Ann Arbor, MI 48109-2029 USA
| | - Nicholas Clements
- Department of Mechanical Engineering, University of Colorado, 135 30th St., Boulder, CO 80305 USA
| | - Jennifer L. Peel
- Department of Environmental and Radiological Health Sciences, Colorado State University, Campus Delivery 1681, Fort Collins, CO 80523-1681 USA
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Clements N, Milford JB, Miller SL, Navidi W, Peel JL, Hannigan MP. Errors in coarse particulate matter mass concentrations and spatiotemporal characteristics when using subtraction estimation methods. J Air Waste Manag Assoc 2013; 63:1386-1398. [PMID: 24558702 DOI: 10.1080/10962247.2013.816643] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In studies of coarse particulate matter (PM10-2.5), mass concentrations are often estimated through the subtraction of PM2.5 from collocated PM10 tapered element oscillating microbalance (TEOM) measurements. Though all field instruments have yet to be updated, the Filter Dynamic Measurement System (FDMS) was introduced to account for the loss of semivolatile material from heated TEOM filters. To assess errors in PM10-2.5 estimation when using the possible combinations of PM10 and PM2.5 TEOM units with and without FDMS, data from three monitoring sites of the Colorado Coarse Rural-Urban Sources and Health (CCRUSH) study were used to simulate four possible subtraction methods for estimating PM10-2.5 mass concentrations. Assuming all mass is accounted for using collocated TEOMs with FDMS, the three other subtraction methods were assessed for biases in absolute mass concentration, temporal variability, spatial correlation, and homogeneity. Results show collocated units without FDMS closely estimate actual PM10-2.5 mass and spatial characteristics due to the very low semivolatile PM10-2.5 concentrations in Colorado. Estimation using either a PM2.5 or PM10 monitor without FDMS introduced absolute biases of 2.4 microg/m3 (25%) to -2.3 microg/m3 (-24%), respectively. Such errors are directly related to the unmeasured semivolatile mass and alter measures of spatiotemporal variability and homogeneity, all of which have implications for the regulatory and epidemiology communities concerned about PM10-2.5. Two monitoring sites operated by the state of Colorado were considered for inclusion in the CCRUSH acute health effects study, but concentrations were biased due to sampling with an FDMS-equipped PM2.5 TEOM and PM10 TEOM not corrected for semivolatile mass loss. A regression-based model was developed for removing the error in these measurements by estimating the semivolatile concentration of PM2.5 from total PM2.5 concentrations. By estimating nonvolatile PM2.5 concentrations from this relationship, PM10-2.5 was calculated as the difference between nonvolatile PM10 and PM2.5 concentrations.
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Affiliation(s)
- Nicholas Clements
- Department of Mechanical Engineering, College of Engineering and Applied Science, University of Colorado at Boulder Boulder, Colorado 80309, USA.
| | - Jana B Milford
- Department of Mechanical Engineering, College of Engineering and Applied Science, University of Colorado at Boulder Boulder, Colorado 80309, USA
| | - Shelly L Miller
- Department of Mechanical Engineering, College of Engineering and Applied Science, University of Colorado at Boulder Boulder, Colorado 80309, USA
| | - William Navidi
- Department of Applied Mathematics and Statistics, Colorado School of Mines, Golden, Colorado, USA
| | - Jennifer L Peel
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - Michael P Hannigan
- Department of Mechanical Engineering, College of Engineering and Applied Science, University of Colorado at Boulder Boulder, Colorado 80309, USA
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Clements N, Kron T, Franich R, Dunn L, Roxby P, Aarons Y, Chesson B, Siva S, Duplan D, Ball D. The effect of irregular breathing patterns on internal target volumes in four-dimensional CT and cone-beam CT images in the context of stereotactic lung radiotherapy. Med Phys 2013; 40:021904. [PMID: 23387752 DOI: 10.1118/1.4773310] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
PURPOSE Stereotactic lung radiotherapy is complicated by tumor motion from patient respiration. Four-dimensional CT (4DCT) imaging is a motion compensation method used in treatment planning to generate a maximum intensity projection (MIP) internal target volume (ITV). Image guided radiotherapy during treatment may involve acquiring a volumetric cone-beam CT (CBCT) image and visually aligning the tumor to the planning 4DCT MIP ITV contour. Moving targets imaged with CBCT can appear blurred and currently there are no studies reporting on the effect that irregular breathing patterns have on CBCT volumes and their alignment to 4DCT MIP ITV contours. The objective of this work was therefore to image a phantom moving with irregular breathing patterns to determine whether any configurations resulted in errors in volume contouring or alignment. METHODS A Perspex thorax phantom was used to simulate a patient. Three wooden "lung" inserts with embedded Perspex "lesions" were moved up to 4 cm with computer-generated motion patterns, and up to 1 cm with patient-specific breathing patterns. The phantom was imaged on 4DCT and CBCT with the same acquisition settings used for stereotactic lung patients in the clinic and the volumes on all phantom images were contoured. This project assessed the volumes for qualitative and quantitative changes including volume, length of the volume, and errors in alignment between CBCT volumes and 4DCT MIP ITV contours. RESULTS When motion was introduced 4DCT and CBCT volumes were reduced by up to 20% and 30% and shortened by up to 7 and 11 mm, respectively, indicating that volume was being under-represented at the extremes of motion. Banding artifacts were present in 4DCT MIP images, while CBCT volumes were largely reduced in contrast. When variable amplitudes from patient traces were used and CBCT ITVs were compared to 4DCT MIP ITVs there was a distinct trend in reduced ITV with increasing amplitude that was not seen when compared to true ITVs. Breathing patterns with a rest period following expiration resulted in well-defined superior edges and were better aligned using an edge-to-edge alignment technique. In most cases, sinusoidal motion patterns resulted in the closest agreements to true values and the smallest misalignments. CONCLUSIONS Strategies are needed to compensate for volume losses at the extremes of motion for both 4DCT MIP and CBCT images for larger and varied amplitudes, and for patterns with rest periods following expiration. Lesions moving greater than 2 cm would warrant larger treatment margins added to the 4DCT MIP ITV to account for the volume being under-represented at the extremes of motion. Lesions moving with a rest period following expiration would be better aligned using an edge-to-edge alignment technique. Sinusoidal patterns represented the ideal clinical scenario, reinforcing the importance of investigating clinically relevant motions and their effects on 4DCT MIP and CBCT volumes. Since most patients do not breathe sinusoidally this may lead to misinterpretation of previous studies using only sinusoidal motion.
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Affiliation(s)
- N Clements
- Department of Physical Sciences, Peter MacCallum Cancer Centre, East Melbourne, Australia.
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Bowers RM, Clements N, Emerson JB, Wiedinmyer C, Hannigan MP, Fierer N. Seasonal variability in bacterial and fungal diversity of the near-surface atmosphere. Environ Sci Technol 2013; 47:12097-106. [PMID: 24083487 DOI: 10.1021/es402970s] [Citation(s) in RCA: 209] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Bacteria and fungi are ubiquitous throughout the Earth's lower atmosphere where they often represent an important component of atmospheric aerosols with the potential to impact human health and atmospheric dynamics. However, the diversity, composition, and spatiotemporal dynamics of these airborne microbes remain poorly understood. We performed a comprehensive analysis of airborne microbes across two aerosol size fractions at urban and rural sites in the Colorado Front Range over a 14-month period. Coarse (PM10-2.5) and fine (PM2.5) particulate matter samples were collected at weekly intervals with both bacterial and fungal diversity assessed via high-throughput sequencing. The diversity and composition of the airborne communities varied across the sites, between the two size fractions, and over time. Bacteria were the dominant type of bioaerosol in the collected air samples, while fungi and plants (pollen) made up the remainder, with the relative abundances of fungi peaking during the spring and summer months. As bacteria made up the majority of bioaerosol particles, we analyzed the bacterial communities in greater detail using a bacterial-specific 16S rRNA gene sequencing approach. Overall, bacterial taxonomic richness and the relative abundances of specific bacterial taxa exhibited significant patterns of seasonality. Likewise, airborne bacterial communities varied significantly between sites and across aerosol size fractions. Source-tracking analyses indicate that soils and leaves represented important sources of bacteria to the near-surface atmosphere across all locations with cow fecal bacteria also representing an important source of bioaerosols at the more rural sites during early fall and early spring. Together, these data suggest that a complex set of environmental factors, including changes in atmospheric conditions and shifts in the relative importance of available microbial sources, act to control the composition of microbial bioaerosols in rural and urban environments.
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Affiliation(s)
- Robert M Bowers
- Department of Ecology and Evolutionary Biology, University of Colorado , UCB 334, Boulder, Colorado 80309, United States
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Kron T, Clements N, Aarons Y, Dunn L, Chesson B, Miller J, Roozen K, Ball D. Radiochromic film for individual patient QA in extracranial stereotactic lung radiotherapy. RADIAT MEAS 2011. [DOI: 10.1016/j.radmeas.2011.05.063] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Clements N, Kron T, Dunn L, Aarons Y, Chesson B, Miller J, Ball D. WE-C-BRA-02: Patient-Specific QA Tool for Motion Management in Hypofractionated Lung Radiotherapy. Med Phys 2010. [DOI: 10.1118/1.3469364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Abstract
PURPOSE Disability management (DM) is a term developed in North America and refers to the prevention and management of injury and illness in the workplace. The purpose of this paper is to report findings of an Australian study that examined whether self-insured employers in that country have implemented integrated DM programmes. Key principles underpinning such programmes are explored to identify the extent to which Australian employers have adopted them. METHOD Data was collected from 29 self-insured Australian companies in three Australian States using a structured interview format with additional open-ended questions. RESULTS It was found that companies have in place, to varying degrees, some of the key elements of disability management programmes. However, these elements were often not well integrated in a comprehensive disability management approach. The focus on workplace-based, early intervention in the area of return to work for injured employees was particularly strong, but there was little evidence of formal labour-management committee structures responsible for implementing DM programmes. CONCLUSIONS If the concept of DM is relevant to the Australian environment then this study would suggest that self-insured companies need to undertake further work to develop integrated approaches to preventing and managing disability in the workplace. Several limitations of this study are highlighted and it is concluded that further work in this area is needed.
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Affiliation(s)
- M Westmorland
- School of Rehabilitation Science, McMaster University, Hamilton, Ontario, Canada
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Abstract
Oncogene and tumor suppressor gene mutations are candidate biomarkers for cancer risk assessment and lesion detection. The K-ras oncogene has previously been associated with non-small cell lung cancer (NSCLC), particularly adenocarcinomas in which reported rates of mutation have approached 30-40%. We have analyzed non-malignant lung tissue from patients with lung cancer and primary lung cancers for K-ras gene mutations. Mutations were detected in 32% cancers and 29% non-malignant lung tissue from patients with cancer. The majority of tumors testing positive were adenocarcinoma of the lung. Normal DNA controls, including peripheral blood lymphocytes and normal lung from non-smokers, were negative. The ability to detect genetic alterations in non-malignant lung tissues is consistent with the concept that genetic alterations are involved in field cancerization of the aerodigestive tract.
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MESH Headings
- Adenocarcinoma/genetics
- Adenocarcinoma/metabolism
- Adenocarcinoma/pathology
- Aged
- Aged, 80 and over
- Carcinoma, Non-Small-Cell Lung/genetics
- Carcinoma, Non-Small-Cell Lung/metabolism
- Carcinoma, Non-Small-Cell Lung/pathology
- Carcinoma, Squamous Cell/genetics
- Carcinoma, Squamous Cell/metabolism
- Carcinoma, Squamous Cell/pathology
- Cell Line
- Female
- Genes, ras
- Humans
- Lung/metabolism
- Lung/pathology
- Lung Neoplasms/genetics
- Lung Neoplasms/metabolism
- Lung Neoplasms/pathology
- Male
- Middle Aged
- Mutation
- Neoplasm Staging
- Point Mutation
- Polymerase Chain Reaction
- Polymorphism, Single-Stranded Conformational
- Risk Assessment
- Smoking
- Tumor Cells, Cultured
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Affiliation(s)
- M A Nelson
- Arizona Cancer Center, College of Medicine, University of Arizona, Tucson 85724 USA
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Mooradian AD, Reed RL, Osterweil D, Clements N, Scuderi P. Lack of an association between the presence of tumor necrosis factor or interleukin-1 alpha in the blood and weight loss among elderly patients. J Am Geriatr Soc 1990; 38:397-401. [PMID: 2329248 DOI: 10.1111/j.1532-5415.1990.tb03536.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
To determine the association between blood cytokine levels and body weight loss in elderly patients, serum levels of cachectin/tumor necrosis factor alpha (TNF) and interleukin-1 alpha (IL-1) were measured with specific and sensitive ELISA systems. Of the 19 healthy young subjects, two (10.5%) had detectable levels of serum TNF and one (5.3%) was positive for IL-1. In the healthy elderly group, two of the 12 subjects (16.7%) had measurable TNF levels and four (33.3%) had elevated IL-1 levels. Of the 61 ambulatory elderly patients, 31.1% had serum that contained TNF and 22.9% had IL-1. Similar proportions were found in 127 nursing home patients. None of the common diseases examined in this study nor any commonly used medications were associated with increased serum cytokine levels. Patients with weight loss of more than 5 lbs were less likely to have elevated serum TNF and IL-1 levels compared to the rest of the group. It is concluded that although elevated levels of TNF or IL-1 may occur more frequently in older groups, there is no evidence for a causal relationship between these circulating cytokines and clinically significant weight loss in the elderly.
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Douglas G, Rang M, Clements N. The prevention of depressed scars after the use of skeletal traction. J Bone Joint Surg Am 1980; 62:307. [PMID: 7358764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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