Figure 1From: The relationship between the rate of melatonin excretion and sleep consolidation for locomotive engineers in natural sleep settings Sleep quality, sleep duration, and aMT6s excretion rate. Mean (±s.e.m.) subjective sleep quality (top panel), sleep duration (middle panel), and aMT6s excretion rate (bottom panel) as a function of time of sleep onset. Data are double-plotted on the x-axis.Back to article page