The aim of this study was to investigate the perception of chemosensory irritation in the oropharyngeal region during the ingestion of irritants. In two experiments subjects sipped and swallowed small samples of an ascending concentration series of capsaicin or piperine and rated the intensity of sensations or irritation perceived at four locations: the anterior tongue, the posterior tongue, the roof of the mouth and the throat. Both experiments revealed that the responsiveness to irritation from capsaicin was significantly higher in the throat than at either the front or back of the tongue. There was no difference between irritation ratings for the throat and the roof of the mouth. Compared with capsaicin, the responsiveness to piperine was more uniform along the rostro-caudal axis; for example, irritation ratings for the throat were similar to those for the anterior tongue. These results support previous findings which indicated that the oral mucosae were not uniformly sensitive to chemical irritants, and suggest further that the throat, which is innervated by both the glossopharyngeal and vagus nerves, plays an important role in the perception of chemesthetic stimuli during ingestion.

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The Departments of Transportation and Treasury and Independent Agencies Appropriations Bill (House Rpt. 108-671) included a directive to the Federal Aviation Administration to conduct a study of flight attendant fatigue. The NASA Ames Research Center Fatigue Countermeasures Group (FCG) was contracted by CAMI to conduct the study. To meet the goals of the study, this report contains a literature review on fatigue as potentially experienced by flight attendants, an evaluation of currently used (actual vs. scheduled) flight attendant duty schedules, and a comparison of these schedules to the current CFRs. The report additionally reviews fatiguerelated incident/accident information from the Aviation Safety Reporting System (ASRS) and the NTSB database. One report section describes the application of three different performance and fatigue models to assess how flight attendant duty schedules contribute to increased levels of fatigue and predicted changes in performance. The report concludes with 6 recommendations concerning issues that require further evaluation, including: (1) Survey of Field Operations. To assess the frequency with which fatigue is experienced, the situations in which it appears, and the consequences that follow; (2) Focused Study of Incident Reports. Flight attendant fatigue study: The Committee is concerned about evidence that FAA minimum crew rest regulations may not allow adequate rest time for flight attendants. Especially since the terrorist attacks of September 11, 2001, the nation's flight attendants have been asked to assume a greater role in protecting the safety of air travelers during flight. Current flight attendant duty and rest rules state that flight attendants should have a minimum of nine hours off duty that may be reduced to eight hours, if the following rest period is ten hours. Although these rules have been in place for several years, they do not reflect the increased security responsibilities since 2001, and only recently have carriers begun scheduling attendants for less than nine hours off. There is evidence that what was once occasional use of the 'reduced rest' flexibility is now becoming common practice at some carriers. Because FAA regulations allow the rest period to commence shortly after the aircraft parks at the gate, the eight hour 'rest' period also includes the time it takes a flight attendant to get out of the terminal, go through customs if necessary, obtain transportation to a hotel and check in. Due to this situation, it is likely that many flight attendants are performing their duties with no more than four to six hours of sleep. To better understand the impact of the minimum rest requirements of CFR §121.467 and CFR §135.273, the Committee recommended a study of flight attendant fatigue. This study is to consider professional input from FAA's Civil Aeromedical Institute. The study should be finalized and submitted to the House and Senate Committees on Appropriations no later than June 1, 2005, including the agency's recommendations on potential regu...

This study examined the role of oxidative stress and the effect of a single dose treatment with N-Acetylcysteine (NAC) on the temporal development of acute laser-induced retinal injury. We used the snake eye/Scanning Laser Ophthalmoscope (SLO) model, an in vivo, non-invasive ocular imaging technique, which has the ability to image cellular retinal detail and allows for studying morphological changes of retinal injury over time. For this study 12 cornsnakes (Elaphe g. guttata) received 5 laser exposures per eye, followed by either a single dose of the antioxidant NAC (150mg/kg, IP in sterile saline) or placebo. Laser exposures were made with a Nd: VO 4 DPSS, 532nm laser, coaxially aligned to the SLO. Shuttered pulses were 20msec x 50 mW; 1mJ each. Retinal images were taken using a Rodenstock cSLO and were digitally recorded at 1, 6, 24-hrs, and at 3-wks post-exposure. Lesions were assessed by two raters blind to the conditions of the study yielding measures of damaged area and counts of missing or damaged photoreceptors. Treated eyes showed a significant beneficial effect overall, and these results suggest that oxidative stress plays a role in laser-induced retinal injury. The use of NAC or a similar antioxidant shows promise as a therapeutic tool.