A Comparison of Intranasal and Oral Scopolamine for Motion Sickness Prevention in Military Personnel

http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA488231&Location=U2&doc=GetTRDoc.pdf



Results from preliminary studies indicate intranasal scopolamine (IN SCOP) has faster absorption, higher bioavailability, and a more reliable therapeutic index than equivalent oral (PO SCOP). The purpose of this study was to determine and compare the efficacy, side effect profile, and pharmacotherapeutics of IN SCOP and PO SCOP. It was hypothesized that IN SCOP would rapidly achieve therapeutic concentrations at lower doses compared to PO SCOP while minimizing medication-induced performance impairment. Fifty-four aviation candidates were randomized to one of three treatment groups (0.4 mg IN SCOP gel, 0.8 mg PO SCOP or placebo) and then exposed to passive Coriolis cross-coupling. Medication efficacy, pharmacotherapeutics and side-effect profiles were tracked for all groups. Analysis revealed there were no significant differences in efficacy among groups. Pharmacotherapeutic data show increased scopolamine absorption and decreased time to reach maximum salivary concentration with intranasal administration, with no significant treatment side effects detected over time. There was a significant decrease in heart rate over time for IN SCOP and PO SCOP versus placebo, while no clinically significant differences were found for either systolic or diastolic blood pressures. In summary, IN SCOP absorption was significantly greater than PO SCOP with no detrimental impact on performance or side effects.

Magnitude and Time Course of Sleep Inertia

http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA487680&Location=U2&doc=GetTRDoc.pdf

The contractor conducted research to: establish the magnitude and duration of sleep inertia after waking from short episodes of sleep; determine how the level and time course of sleep inertia varies according to circadian phase; and determine how the level and time course of sleep inertia varies according to the duration of prior waking. The specific objectives were 1. To determine the magnitude of any decrements in performance and subjective and/or neurophysiological alertness upon waking from naps ending at 0200 hrs (after about 20 hrs awake), compared to the 'no nap' condition, 2. To determine the time course for any decrements to return to baseline levels (compared to the no-nap condition). 3. To determine whether the nap (duration, proportion of SWS or sleep stage on awakening) influences the magnitude or time course of sleep inertia effects under these conditions.

Operating an Unmanned Aerial System from a Moving Platform

http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA487201&Location=U2&doc=GetTRDoc.pdf

While the Spatial Disorientation (SD) has long been recognized as an important causal factor in aviation incidents and accidents, it is only beginning to be recognized as a factor in Uninhabited Aerial Systems (UASs). As a first step towards better understanding the effects of control platform motion on manual UAV control Olson, DeLauer and Fale (2006) had 10 rated Air Force pilots fly a simulated UAV task (MS Flight Simulator) from a motion capable control platform (aircraft simulator). Participants performed two basic flight tasks - a vertical task (climb/descent) and a horizontal (turning task). The control platform motion was varied to provide either congruent, neutral, or conflicting motion cues. The current study replicates the simulator study using an Cessna-172 aircraft as the control platform. This will allow for a more complete examination of platform motion cues since simulators cannot adequately simulate sustained motion. This study also adds a landing task to examine glide path and azimuth error. The results of this study mirror those of the previous simulator study and show a general increase in error. These results have implications for planned UAV operations from both fighter and transport aircraft.

Neck Muscle Fatigue Resulting from Prolonged Wear of Weighted Helmets under High G Acceleration

http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA487277&Location=U2&doc=GetTRDoc.pdf



In search of guidelines for designing helmet-mounted systems without adding risk for additional pilot neck pain or injury, RHPG collaborated with the panoramic night vision goggle (PNVG) program office to begin this research. Neck muscles become fatigued as they work to stabilize the additional weight of helmet systems. The center of gravity (CG) of each individual helmet configuration varies according to the accessories attached. Neck strength measurements before and after high G simulations provided indications of muscle fatigue related to different helmets. Results show that volunteer test subjects tolerated the additional loads stabilized by their neck muscles when changes in CG are controlled. Questions remain unanswered concerning heavier helmets when CG cannot be controlled and how they might influence operational performance.

The Efficacy of Dextroamphetamine as a Motion Sickness Countermeasure for the Use in Military Operational Environments

http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA487648&Location=U2&doc=GetTRDoc.pdf

Previous research examining pharmacological solutions for motion sickness have reported that dextroamphetamine (d-amphetamine) imparts significant protection against provocative motion without conferring drowsiness or significant side effects. If the purported anti-motion sicknesses properties of d-amphetamine are accurate, the military could utilize a single medication for motion sickness and fatigue prevention. The purpose of this study was to determine the efficacy and side effect profile of this potential motion sickness countermeasure for use in military environments. It was hypothesized that subjects in the oral d-amphetamine condition would tolerate more head movements than subjects in the placebo condition, without performance decrements or significant side effects. Thirty-six aviation candidates were randomized to one of two treatment groups and then exposed to passive Coriolis cross-coupling. Medication efficacy was determined by number of head movements tolerated between groups. Cognitive and medication side-effect profiles for both groups were derived from performance on a computer based cognitive battery, measurements of near-focus visual accommodation (VA), scores on the Karolinska Sleepiness Scale (KSS), and motion sickness questionnaires. Analyses demonstrated that there were no significant differences in the number of head movements tolerated between groups and no treatment effects over time on the cognitive battery, VA, or KSS, p > 0.05.

Climate Change and Extreme Heat Events

http://download.journals.elsevierhealth.com/pdfs/journals/0749-3797/PIIS0749379708006867.pdf


The association between climate change and the frequency and intensity of extreme heat events is now well established. General circulation models of climate change predict that heatwaves will become more frequent and intense, especially in the higher latitudes, affecting large metropolitan areas that are not well adapted to them. Exposure to extreme heat is already a significant public health problem and the primary cause of weather-related mortality in the U.S. This article reviews major epidemiologic risk factors associated with mortality from extreme heat exposure and discusses future drivers of heat-related mortality, including a warming climate, the urban heat island effect, and an aging population. In addition, it considers critical areas of an effective public health response including heat response plans, the use of remote sensing and GIS methodologies, and the importance of effective communications strategies.