The aim of this study was to characterize the sleep-wake cycle, daytime sleepiness and sleep quality of high school teachers. Ninety-eight high school teachers participated in this study. They were asked to complete the Health and Sleep, Horne & Ostberg, Epworth Sleepiness Scale and Pittsburgh Sleep Quality Index questionnaires and to keep a 14-day sleep diary. This study showed that high-school teachers wake up on average 1 h 12 min earlier (ANOVA; p < 0.05) and go to bed on average 34 min earlier (ANOVA; p < 0.05) during the week than on the weekend. This results in an average of 42 min less time in bed (ANOVA; p < 0.05) on weekdays and characterizes partial sleep deprivation. Moreover, 46% and 51% of teachers were diagnosed with excessive daytime sleepiness and poor sleep quality (χ2; p > 0.05), respectively. Therefore, high-school teachers show characteristics of partial sleep deprivation that may contribute to excessive daytime sleepiness and poor sleep quality. This situation may compromise health and quality of life, in addition to teaching performance that can affect the education of their students.

The effect of puberty on circadian rhythmicity in nonhuman primates has been little studied, even though it has been demonstrated that puberty-related changes in circadian activity rhythm occur in a number of species, including humans. To characterize the motor activity rhythm during puberty in common marmosets (Callithrix jacchus), six animals was continuously monitored by actimeters between their 5th and 12th months of age. The animals were housed with their families in outdoor cages under seminatural conditions. Onset of puberty was determined from fecal estrogen and progesterone levels in females and androgen levels in males. The spectral power of the circadian component stabilized later in the last two animals to enter puberty. The bimodal characteristic of the active phase in this species became progressively more apparent over the course of the months in which the mean temperature was highest, irrespective of the animal's age. Although the onset of activity advanced after entry into puberty, this parameter showed a strong correlation with sunrise, indicating that seasonality influences this variable. Neither age nor climatic factors included in the regression model influenced the differences in phase angles between sunrise and onset of activity, and between sunset and offset of activity. Total activity was the only parameter influenced by age in the regression model, showing an increase after entry into puberty. Despite the evidence of pubertal influence on both the circadian component and total activity, under seminatural conditions seasonal factors may have a more important effect on motor activity rhythm in common marmosets.

ABSTRACT-Children tend to sleep and wake up early and to exhibit daytime sleep episodes. To evaluate the impact of school start times on sleepiness and attention in preschool children, this study compared the temporal patterns of sleep, daytime sleepiness, and the components of attention between children aged 4-6 years that study in the morning (n = 66) and the afternoon (n = 144) shifts. The former get up 1 hr and 30 min earlier on weekdays and show lower efficiency on the sustained attention task than those who study in the afternoon. Thus, the morning shift was associated with a reduction in nighttime sleep, which might have a negative effect on children's performance in the morning, causing higher levels of daytime sleepiness and a decline in sustained attention. Because only one parameter of one component of attention was negatively affected, further studies are needed to confirm this effect on cognition.

The effect of nest box availability on the circadian activity rhythm (CAR) was compared in a diurnal primate kept in two conditions: with and without nest box, in a light-dark (LD) cycle (12:12) and constant light (LL). Marmosets kept in LD without nest box showed a longer duration of the activity phase (α), smaller day-to-day variability in activity onset and offset and higher levels of activity, particularly towards the end of the activity time. In LL, all animals maintained with nest box expressed free-running CAR, but without nest box, 3 of the 4 individuals showed relative coordination with the outdoor LD cycle, possibly due to social synchronization with captive marmosets maintained outdoors. All animals showed longer α and higher levels of activity without nest box. Thus, the availability of a nest box is an important aspect in maintaining marmosets, influencing CAR expression in this diurnal primate in LD and LL conditions, possibly due to differences in light exposure that induces masking. Further studies are needed to evaluate the effects of the unavailability of a nest box on CAR in LL conditions.

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