The present study investigated whether exposure to aromas during recess periods affects work performance. Subjects comprised 36 healthy male students (mean age, 24.2 +/- 2.2 years) who were randomly divided into three groups: (1) control group, not exposed to aroma during recesses; (2) jasmine group, exposed to jasmine aroma during recesses; and (3) lavender group, exposed to lavender aroma during recesses. All participants completed five work sessions performing a task requiring concentration on a computer monitor, with each session lasting 60 min. Recess periods of 30 min were provided between each session. To clarify the time at which work concentration was lowest, work performance for the control group was analyzed. Concentration was lowest in the afternoon period, where afternoon drowsiness is strongest. Comparison of the three groups for this time period indicated significantly higher concentration levels for the lavender group than for the control group. No such effect was noted for the jasmine group. Although lavender is a sedative-type aroma, use during recess periods after accumulation of fatigue seems to prevent deterioration of performance in subsequent work sessions.

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The relationship of hydrogen peroxide (H 2 O 2 ) levels in bile with liver SOD and GSH Px activity in selenium (Se)-deˆcient rats is discussed. Normal rats and 7 groups of rats fed a Se-deˆcient diet with diŠerent feeding periods were examined. H 2 O 2 levels in bile were measured using the spin-trapping method with electron spin resonance (ESR). Bile H 2 O 2 levels in the initial stage (20 60 min from start of the cannulation) of measurement were increased depending on the length of the feeding period with the Se-deˆcient diet and absence of Se. Bile H 2 O 2 levels in the later stage (60 120 min) of measurementˆrst increased with the length of feeding with the Se-deˆcient diet and then decreased with longer feeding periods. Bile H 2 O 2 levels immediately after the operation were relatively low in almost all cases. The operation may result in oxidative stress to generate H 2 O 2 . Liver GSH Px activity decreased depending on the length of the feeding period with the Se-deˆcient diet and existence of Se. Liver SOD activity increased in Se-deˆcient groups. It is suggested that the H 2 O 2 levels in bile are related to decreased GSH Px activity, SOD activity, and also the oxidative stress caused by surgery. Therefore the H 2 O 2 levels in bile can be used as an index of sensitivity to oxidative stress. Although severe oxidative stress may decrease SOD activity, Se deˆciency can induce liver SOD activity.Key words-oxidative stress; X band ESR; Fenton's reaction; spin trapping; hydroxyl radical; glutathione peroxidase

The patient was a 21‐year‐old male who complained of daytime sleepiness. His multiple sleep latency test (MSLT) showed multiple sleep onset REM periods (SOREMPs). The nadir of his core body temperature appeared after waking. However, we did not obtain a sleep log prior to conducting the MSLT. In addition, an actigraphy showed that he dozed before and between MSLT naps. His dozes were thought to influence mean sleep latency and facilitate SOREMP. Actigraphy should be performed not only prior to testing, but also on the day of testing to monitor patient status and aid in the interpretation of results.