CGEM: A Cerebral Blood Flow Based Computer Model of Gz-Induced Effects

[Narrated Slideshow Presentation]. 91st AsMA Annual Scientific Meeting, Denver, CO, United States.Narrated Slideshow Presentation: A Cerebral Blood Flow Based Computer Model of Gz-Induced Effects, presented at 91st AsMA Annual Scientific Meeting, Denver, CO, United States. Describes software model (the Civil Aerospace Medical Institute G-Effects Model [CGEM]) based on physical and physiological variables related to inflight tissue resupply, using oxygen flow as a proxy for supply availability, developed to evaluate risk of G-LOC and related phenomena in aeronauts

Effect of Pelvic Loading during Anthropomorphic Test Device Storage

As part of a larger project aimed at gaining a better understanding of factors that affect the quality of test results using Anthropomorphic Test Devices (ATDs), the FAA tested the effects of long-term static ATD pelvis loading during storage. Testing simulated two types of ATD pelvis storage methods of the 50th percentile Hybrid III ATD for one year. The objective was to measure any changes to the rubber and foam that cover the metallic pelvis of the ATD. In one storage method, the ATD pelvis had no contact between the foam and rubber shell and an external surface. The second storage method had the pelvis loaded with 125 lbs on the bottom side of the pelvis

Seat and Occupant Response in Energy Absorbing Seats

The Federal Aviation Administration (FAA) has undertaken research programs to support streamlining various facets of the seat certification process. Previous research evaluated potential methods to qualify replacement of worn seat cushions used in low G applications (Part 25 and Part 23 passenger) and better quantify variability in vertical testing. The current research focused on higher energy rotorcraft environment where seating systems have energy absorption built in to reduce an occupant\u2019s risk of spinal injury

Effects of Cannabinoids and Postmortem Interval on Gene Expression: Considerations for the Forensic Genetic Analysis of Civil Aviation Accident Victims

Project Name: Gene Expression and Biomarker Utility in Postmortem SamplesCannabis is the third most commonly used drug of abuse following alcohol and tobacco in the United States. Cannabis is federally classified as a Schedule I substance under the Controlled Substances Act of 1970 but is legal for medicinal and/or recreational purposes in 39 US states. However, cannabis use by safety-sensitive personnel, including certificated pilots, remains prohibited in the US. Despite the prohibition on cannabis use among pilots, a number of fatal accidents in which the deceased pilot tests positive for delta-9-tetrahydrocannabinol (THC) and/or metabolites in post-accident toxicological analyses still occur. No correlation is known to exist between blood or tissue THC concentration and degree of functional impairment, frustrating efforts to ascribe causality for this subset of aviation accidents. One possible solution for this lack of correlation is forensic transcriptome analysis, specifically postmortem analysis of the expression of cannabis-responsive genes whose expression can be correlated with measures of cognitive impairment. Cannabis consumption results in quantifiable changes in gene expression, from which biomarkers correlating with the timeline of use and impairment may be identified. Complicating matters is that the transcriptome is not static postmortem, with hundreds, if not thousands, of genes exhibiting differential expression throughout the postmortem interval

Gene Expression Biomarkers of the Response To Sleep Loss With and Without Modafinil

Sleep disruption presents a substantial risk to health and safety, particularly due to the risks of performance degradation in safety-critical operations that can result in catastrophic injuries or mortality. Federal regulations exist to minimize the risks of fatigue with limitations on hours worked and requirements for fatigue risk management plans. Yet, even with workload controls and scheduled opportunities for rest, fatigue may be caused by factors such as personal and lifestyle choices, illness, and circadian disruption from travel across multiple time zones. Complicating risk mitigation is the challenge of identifying and measuring fatigue. Here, we report on gene expression biomarkers (biological indicators) for cognitive impairment during sleep loss. We observe hundreds of genes whose expression is associated with attention changes during one night of sleep loss. Several genes are identified that we previously associated with attention impairment in a separate study of sleep loss. The reproducibility of findings may indicate the robustness of these candidate fatigue impairment biomarkers. However, some biomarker genes only associate with certain tests of impairment (e.g., attention lapses but not self-reported fatigue), suggesting that different biomarker panels may be developed to assess the particular cognitive domains that need monitoring for a given safety critical operation. We also find that using a drug countermeasure (modafinil) not only helps mitigate impairment on tests of attention lapses, but also disrupts gene expression associations with attention lapses. Further research is needed to confirm whether this represents a unique effect of modafinil administration, or emphasizes the need to ensure biomarker validation occurs both in the presence and absence of countermeasures

Effects of Airplane Cabin Interiors on Egress I: Assessment of Anthropometrics, Seat Pitch, and Seat Width on Egress

6973GH-19-C-00102Within the Federal Aviation Administration (FAA) Reauthorization Act of 2018, Pub. L. No. 115-254 \ua7 577, Congress required that \u201c\u2026the Administrator of the Federal Aviation Administration shall issue regulations that establish minimum dimensions for passenger seats on aircraft operated by air carriers in interstate air transportation or intrastate air transportation, including minimums for seat pitch, width, and length, and that are necessary for the safety of passengers.\u201d This research project was developed to provide information to rule-makers within the FAA to meet this requirement

Effects of Airplane Cabin Interiors on Egress I: Assessment of Anthropometrics, Seat Pitch, and Seat Width on Egress, DOT-FAA-AM_21/01 [supporting datasets: videos]

6973GH-19-C-00102Because of the very large file sized of these videos, patrons will need to download the video files directly, using the "Direct Download" links provided in the README.These 60 video recordings represent the visual recordings of the measurement of the two research objectives of the study \u201cEffects of Airplane Cabin Interiors on Egress I: Assessment of Anthropometrics, Seat Pitch, and Seat Width on Egress," DOT/FAA/AM-21/01. The first objective was to determine what percentage of the American population, based on anthropometric measurements, would not be able to sit in transport airplane passenger seats at the currently narrowest and even narrower seat pitch. Second, this study sought to determine the effect of seat pitch and seat width on individual egress time during an aircraft evacuation.The 12 videos with file names which contain with the phrase "ExpSeatingMockupDay..." record participants sitting in or attempting to sit in a seat mock-up that matched the narrowest seat pitch they would experience in the evacuation trials, and to attempt to sit in or to sit in a seat mock-up of a narrower seat pitch than what would be presented in the evacuation trials. (See pages 9 and 10 of the related report for more information.) Each video is about 2 hours long, and shows a single camera view from the perspective of the left wall of an aircraft. The video records participant actions as each participant attempts to sit in the center seat of the third of three rows, and then the center seat of the second of three rows. The recordings are color video, without a soundtrack. Participant faces are blurred to protect individual privacy.The 48 videos with file names that start with "R01.mp4" and increment to "R48.mp4" are the recordings of the evacuations from CAMI FlexSim. (See pages 11 through 13 of the related report for more information.) Each video is about 45 seconds long, with the frame divided into 4 quarters, showing three views of the evacuation, and a single title slide with the date of the evacuation trial, and the trial number, which matches the file number on the recording. The view in the upper left of the frame is a view overhead and behind the flight attendant supervising the evacuation. The view in the upper right of the frame shows the exterior of the simulator to record how participants exit. The view in the lower right of frame shows the view from the rear of the simulator, as participants evacuate away from the camera to the front of the simulator. The lower left of the frame is the title slide. In the center of the frame is a timer, counting up the total time of the evacuation. The recordings are color video, without a soundtrack. Participant faces are blurred to protect individual privacy.The videos can be viewed on any modern video player

Effects of Airplane Cabin Interiors on Egress I: Assessment of Anthropometrics, Seat Pitch, and Seat Width on Egress, DOT-FAA-AM_21/01 [supporting datasets]

6973GH-19-C-00102Within the Federal Aviation Administration (FAA) Reauthorization Act of 2018, Pub. L. No. 115-254 \ua7 577, Congress required that \u201c\u2026the Administrator of the Federal Aviation Administration shall issue regulations that establish minimum dimensions for passenger seats on aircraft operated by air carriers in interstate air transportation or intrastate air transportation, including minimums for seat pitch, width, and length, and that are necessary for the safety of passengers.\u201d A total of 775 participants were recruited to assist with meeting two research objectives: first, to determine what percentage of the American population, based on anthropometric measurements, would be unable to sit in transport airplane passenger seats at the currently narrowest width and even narrower seat pitch. The second objective was to determine the effect of seat pitch and seat width on individual egress time. The study included 718 participants assigned to 12 groups who participated in up to four evacuations from the FAA\u2019s Flexible Aircraft Cabin Simulator (FlexSim), with various seat pitch and width combinations. Based on this study's results, currently flying seat pitches using seats of similar size or smaller than those used in this project can accommodate and not impede egress for 99% of the American population. This project also concluded that, similar to previous evacuation research, as long as ergonomic minimums are maintained, the transport airplane's interior configuration, including seat pitch and width, has not been shown to influence evacuations. This research project was developed to provide information to rule-makers within the FAA to meet this requirement

Comparison of the Human Transcriptional Response to Three Hypoxic Environments

DTFAWA-10-C-00080Hypoxia awareness training is a standard facet of military aviator training that is performed to familiarize aviators with the symptoms of hypoxia. The three most common training devices are the hypobaric altitude chamber (AC), the normobaric reduced oxygen breathing device (ROBD), and the normobaric reduced oxygen breathing environment (ROBE). The AC creates hypoxic conditions using reduced atmospheric pressure. The ROBD and ROBE create normobaric hypoxic conditions by supplying a controlled reduced-oxygen gas mixture to trainees who don an aviation-style breathing mask or occupy a sealed chamber, respectively. To determine if differences in the transcriptional response to each of these training devices exist, blood ribonucleic acid (RNA) samples from ten volunteer participants were analyzed by microarray. The resulting gene expression measures were screened for significant changes across time points within and across device runs. Few genes were significant in these comparisons; the most significant differences between timepoints were observed in small nucleolar RNAs and noncoding RNAs, as well as one microRNA and one transfer RNA. The transcriptional response to each training device differs slightly as determined by differences in transcription between time points. However, the role of these transcriptional changes is unclear, as little information exists as to their function or role in the hypoxic response. As all the examined methods induced hypoxic symptoms, and very little difference was observed in gene expression between methods, this limited study did not detect the presence of substantial differences between hypoxia awareness training devices. Future studies using more sensitive sequencing-based gene expression analysis techniques and larger sample sizes may improve the detection of transcriptional differences induced by each training device

Development, Verification, and Validation of G-LOC Model [Data Management Plan]

BLI AM11J-OC25.1When citing this Data Management Plan use:Kyle Copeland. (2023). "Development, Verification, and Validation of G-LOC Model" [Data Management Plan]. DMPHub. https://doi.org/10.48321/D1CH0JThe published models of G-LOC and recovery in the public domain are based on empirical fits to data from centrifuge experiments and on blood pressure. A resource-flow based model of G-LOC and recovery built using more detailed physics and physiology will be developed. This new model is implemented via software and results will be compared with existing models for predicting symptoms known to occur in aeronauts during positive and negative Gz accelerations encountered in aerobatic flight and observed in centrifuge experiments