Commercial Aircraft-Cabin Egress: The Current State of Simulation Model Development and the Need for Future Research

There has been increasing interest in developing simulation models capable of analyzing commer cial aircraft-cabin egress under both non-life- threatening and life-threatening scenarios. At issue is the ability to accurately simulate human behavior within non-toxic environments, as well as the debilitating effects that toxic environments (e.g., fire and smoke) have on human-decision making. A set of criteria has been identified by the Federal Aviation Administration for developing simulation models capable of analyzing commer cial aircraft-cabin egress. These criteria are used to (a) compare the capabilities and limitations of four aircraft-evacuation models in existence to day, (b) identify the issues that need to be ad dressed when developing these types of models, and (c) propose a new paradigm for developing aircraft-cabin egress models.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

Self-Reported Sexually Transmitted Infections after Incarceration in Women with or at Risk for HIV in the United States, 2007-2017

Background: U.S. women who have been incarcerated report high rates of sexual risk behavior and sexually transmitted infections (STIs). Materials and Methods: We estimated the effect of incarceration on the time to first incident STI in a multicenter cohort of U.S. women with or at risk for HIV. We used marginal structural models to compare time to first self-reported gonorrhea, chlamydia, or trichomonas infection for nonincarcerated women and incarcerated women. Covariates included demographic factors, HIV status, sex exchange, drug/alcohol use, and prior incarceration. Results: Three thousand hundred twenty-four women contributed a median of 4 at-risk years and experienced 213 first incident STI events. The crude incidence of STIs was 3.7 per 100 person-years for incarcerated women and 1.9 per 100 person-years for nonincarcerated women. The weighted hazard ratio for incident STIs was 4.05 (95% confidence interval: 1.61-10.19). Conclusion: Women with or at risk for HIV in the United States who have recently experienced incarceration may be at increased STI risk

Incidence and Prevalence of Incarceration in a Longitudinal Cohort of Women at Risk for Human Immunodeficiency Virus in the United States, 2007-2017

Background: To estimate the incidence, prevalence, frequency, and duration of incarceration and to identify risk factors for incarceration among women at risk for human immunodeficiency virus (HIV) in the United States. Methods: During semiannual study visits in a multicenter cohort study, 970 HIV sero-negative participants at risk for HIV were asked about their own incarceration (10/2007-09/2017) and incarceration of sexual partners (10/2013-09/2017). We used descriptive statistics and multivariable log-binomial regression to identify baseline predictors of incident incarceration. Results: Median follow-up time across the 970 participants was 5.5 years (IQR 3.5-9.5). Nearly half (n = 453, 46.7%) of participants were incarcerated during or before the study, and the incarceration rate was 5.5 per 100 person-years. In multivariable models, incident incarceration was associated with prior incarceration (RR 5.20, 95% CI: 3.23-8.41) and noninjection drug use (RR 1.57, 95% CI: 1.10-2.25). Conclusions: Incarceration is common for women at risk for HIV. Prevention interventions that address the complex interplay of drug use, sex exchange, and housing instability for women who have experienced incarceration have the potential to reach an important group of U.S. women at risk of HIV infection

Dilution of Boundary Layer Cloud Condensation Nucleus Concentrations by Free Tropospheric Entrainment During Marine Cold Air Outbreaks

Recent aircraft measurements over the northwest Atlantic enable an investigation of how entrainment from the free troposphere (FT) impacts cloud condensation nucleus (CCN) concentrations in the marine boundary layer (MBL) during cold-air outbreaks (CAOs), motivated by the role of CCN in mediating transitions from closed to open-cell regimes. Observations compiled over eight flights indicate predominantly far lesser CCN concentrations in the FT than in the MBL. For one flight, a fetch-dependent MBL-mean CCN budget is compiled from estimates of sea-surface fluxes, entrainment of FT air, and hydrometeor collision-coalescence, based on in-situ and remote-sensing measurements. Results indicate a dominant role of FT entrainment in reducing MBL CCN concentrations, consistent with satellite-observed trends in droplet number concentration upwind of CAO cloud-regime transitions over the northwest Atlantic. Relatively scant CCN may widely be associated with FT dry intrusions, and should accelerate cloud-regime transitions where underlying MBL air is CCN-rich, thereby reducing regional albedo. © 2022. American Geophysical Union. All Rights Reserved.6 month embargo; first published: 31 May 2022This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Assessment of NAAPS-RA performance in Maritime Southeast Asia during CAMP2Ex

Monitoring and modeling aerosol particle life cycle in Southeast Asia (SEA) is challenged by high cloud cover, complex meteorology, and the wide range of aerosol species, sources, and transformations found throughout the region. Satellite observations are limited, and there are few in situ observations of aerosol extinction profiles, aerosol properties, and environmental conditions. Therefore, accurate aerosol model outputs are crucial for the region. This work evaluates the Navy Aerosol Analysis and Prediction System Reanalysis (NAAPS-RA) aerosol optical thickness (AOT) and light extinction products using airborne aerosol and meteorological measurements from the Cloud, Aerosol, and Monsoon Processes Philippines Experiment (CAMP2Ex) conducted in 2019 during the SEA southwest monsoon biomass burning season. Modeled AOTs and extinction coefficients are compared to those retrieved with a high spectral resolution lidar (HSRL-2). Agreement between simulated and retrieved AOT (R2Combining double low line 0.78, relative bias Combining double low line-5 %, normalized root mean square error (NRMSE) Combining double low line 48 %) and aerosol extinction coefficients (R2Combining double low line 0.80, 0.81, and 0.42; relative bias Combining double low line 3 %, -6 %, and -7 %; NRMSE Combining double low line 47 %, 53 %, and 118 % for altitudes between 40-500, 500-1500, and >1500 m, respectively) is quite good considering the challenging environment and few opportunities for assimilations of AOT from satellites during the campaign. Modeled relative humidities (RHs) are negatively biased at all altitudes (absolute bias Combining double low line-5 %, -8 %, and -3 % for altitudes 1500 m, respectively), motivating interest in the role of RH errors in AOT and extinction simulations. Interestingly, NAAPS-RA AOT and extinction agreement with the HSRL-2 does not change significantly (i.e., NRMSE values do not all decrease) when RHs from dropsondes are substituted into the model, yet biases all move in a positive direction. Further exploration suggests changes in modeled extinction are more sensitive to the actual magnitude of both the extinction coefficients and the dropsonde RHs being substituted into the model as opposed to the absolute differences between simulated and measured RHs. Finally, four case studies examine how model errors in RH and the hygroscopic growth parameter, γ, affect simulations of extinction in the mixed layer (ML). We find NAAPS-RA overestimates the hygroscopicity of (i) smoke particles from biomass burning in the Maritime Continent (MC) and (ii) anthropogenic emissions transported from East Asia. This work mainly provides insight into the relationship between errors in modeled RH and simulations of AOT and extinction in a humid and tropical environment influenced by a myriad of meteorological conditions and particle types. These results can be interpreted and addressed by the modeling community as part of the effort to better understand, quantify, and forecast atmospheric conditions in SEA. Copyright © 2022 Eva-Lou Edwards et al.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Total organic carbon and the contribution from speciated organics in cloud water: Airborne data analysis from the CAMP2Ex field campaign

This work focuses on total organic carbon (TOC) and contributing species in cloud water over Southeast Asia using a rare airborne dataset collected during NASA's Cloud, Aerosol and Monsoon Processes Philippines Experiment (CAMP2Ex), in which a wide variety of maritime clouds were studied, including cumulus congestus, altocumulus, altostratus, and cumulus. Knowledge of TOC masses and their contributing species is needed for improved modeling of cloud processing of organics and to understand how aerosols and gases impact and are impacted by clouds. This work relies on 159 samples collected with an axial cyclone cloud-water collector at altitudes of 0.2-6.8ĝ€¯km that had sufficient volume for both TOC and speciated organic composition analysis. Species included monocarboxylic acids (glycolate, acetate, formate, and pyruvate), dicarboxylic acids (glutarate, adipate, succinate, maleate, and oxalate), methanesulfonic acid (MSA), and dimethylamine (DMA). TOC values range between 0.018 and 13.66ĝ€¯ppmĝ€¯C with a mean of 0.902ĝ€¯ppm C. The highest TOC values are observed below 2ĝ€¯km with a general reduction aloft. An exception is samples impacted by biomass burning for which TOC remains enhanced at altitudes as high as 6.5ĝ€¯km (7.048ĝ€¯ppmĝ€¯C). Estimated total organic matter derived from TOC contributes a mean of 30.7ĝ€¯% to total measured mass (inorganics + organics). Speciated organics contribute (on a carbon mass basis) an average of 30.0ĝ€¯% to TOC in the study region and account for an average of 10.3ĝ€¯% to total measured mass. The order of the average contribution of species to TOC, in decreasing contribution of carbon mass, is as follows (±1 standard deviation): acetate (14.7ĝ€¯±ĝ€¯20.5ĝ€¯%), formate (5.4ĝ€¯±ĝ€¯9.3ĝ€¯%), oxalate (2.8ĝ€¯±ĝ€¯4.3ĝ€¯%), DMA (1.7ĝ€¯±ĝ€¯6.3ĝ€¯%), succinate (1.6ĝ€¯±ĝ€¯2.4ĝ€¯%), pyruvate (1.3ĝ€¯±ĝ€¯4.5ĝ€¯%), glycolate (1.3ĝ€¯±ĝ€¯3.7ĝ€¯%), adipate (1.0ĝ€¯±ĝ€¯3.6ĝ€¯%), MSA (0.1ĝ€¯±ĝ€¯0.1ĝ€¯%), glutarate (0.1ĝ€¯±ĝ€¯0.2ĝ€¯%), and maleate (<ĝ€¯0.1ĝ€¯±ĝ€¯0.1ĝ€¯%). Approximately 70ĝ€¯% of TOC remains unaccounted for, highlighting the complex nature of organics in the study region; in samples collected in biomass burning plumes, up to 95.6ĝ€¯% of TOC mass is unaccounted for based on the species detected. Consistent with other regions, monocarboxylic acids dominate the speciated organic mass (g1/4ĝ€¯75ĝ€¯%) and are about 4 times more abundant than dicarboxylic acids. Samples are categorized into four cases based on back-trajectory history, revealing source-independent similarity between the bulk contributions of monocarboxylic and dicarboxylic acids to TOC (16.03ĝ€¯%-23.66ĝ€¯% and 3.70ĝ€¯%-8.75ĝ€¯%, respectively). Furthermore, acetate, formate, succinate, glutarate, pyruvate, oxalate, and MSA are especially enhanced during biomass burning periods, which is attributed to peat emissions transported from Sumatra and Borneo. Lastly, dust (Ca2+) and sea salt (Na+/Cl-) tracers exhibit strong correlations with speciated organics, supporting how coarse aerosol surfaces interact with these water-soluble organics. © Copyright:Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]