Richard J. Brook

A Double-Blind Trial of Melatonin as a Treatment for Jet Lag in International Cabin Crew

This study investigated the efficacy of oral melatonin in alleviating jet lag in flight crew after a series of international flights. The optimal time for taking melatonin in this group was also investigated. In a double-blind placebo-controlled trial, 52 international cabin crew were randomly assigned to three groups; early melatonin (5 mg started 3 days prior to arrival until 5 days after return home); late melatonin (placebo for 3 days then 5 mg melatonin for 5 days); and placebo. Daily ratings showed a trend in jet lag, mood, and sleepiness measures toward an improved recovery in the late melatonin group and a worse recovery in the early melatonin group as compared to placebo. Retrospective ratings made 6 days after arrival showed the late melatonin group reported significantly less jet lag and sleep disturbance following the flight compared to placebo. The late melatonin group also showed a significantly faster recovery of energy and alertness than the early melatonin group, which reported a worse overall recovery than placebo. These findings show melatonin may have potential benefits for international aircrew.

On the Use of a Regret Function to Set Significance Points in Prior Tests of Estimation

Abstract In linear models, an F-test may be used to decide on restricted or unrestricted estimators. To avoid the arbitrariness of the significance level and undesirable quadratic risk properties, a regret criterion is proposed, extending the results of Sawa and Hiromatsu [4]. Optimal critical points of the prior F-test and their corresponding significance levels are tabulated for different sample sizes and number of restrictions. The critical value is generally close to two, but much smaller if the columns of the design matrix are nonorthogonal. This suggests that if the F-statistic is more than two, the unrestricted estimator should be used.

Conditioning allergic skin responses in humans: a controlled trial.

Classical conditioning of immune responsiveness has been extensively investigated in animals, but few successful studies have been reported with humans.We report the results of a study in which an attempt was made to demonstrate conditioned alteration to an allergic skin test response in humans. For 8 of 10 trials, allergic skin tests were administered to one forearm of volunteer subjects, and saline was administered to the other forearm. For the other two trials, the test substances were covertly switched between arms, but no changes in response resulted from this maneuver that could be ascribed to conditioning.

On the expected length of the least squares coefficient vector

Abstract As a motivation for biased estimation procedures, it is often stated that the vector of the least squares estimator is too long on average. Some authors have given an invalid proof of this statement. In this note a proof is given and comments added to indicate how large is this average length.

COMMENT ON: MEASUREMENT AND APPRAISAL (DEWE, 1995)

Response to two issues raised by Dewe is provided. The tree diagram permits a different view of data and may be utilized with various models.