Tryptophan can be metabolized via 5-hydroxytryptamineϭserotonin to melatonin by a series of 4 enzymes in pineal body. Lack of serotonin in body fluid in the brain during daytime can lead to several psychiatric disorders, while shortage of plasma-melatonin at night can be related to sleep disorders. The Morningness-Eveningness (M-E) questionnaire and the original questionnaire including questions on sleep habits, mental symptoms, and contents of meals were administered to 1055 infants aged 0-6 yrs, 751 students attending an elementary school, and 473 students attending junior high school in Kochi City (33°N). The index of tryptophan taken at breakfast (Trp-Index) was calculated as tryptophan amount per one meal based on the tryptophan included in each 100 g of the foods and a standard amount of food per one meal. A significant positive-correlation between M-E scores and Trp-Index was not shown by relatively older students, aged 9-15 yrs (Pearson's test, rϭ0. 044-0.123, pϭ0.071-0.505), whereas a significant positive correlation was shown by infants and young elementary school students aged 0-8 yrs (rϭ0.180, 0.258, pϽ0.001). The more frequently the infants had difficulty falling asleep at bedtime and waking up in the morning, the less the Trp-Indices taken at breakfast were (Kruskall-Wallis-test, pϭ0.027 for difficulty falling asleep; pϭ0.008 for difficulty waking up). The more frequently infants became angry even by a little trigger, or depressed, the lower (more evening-typed) the M-E scores were (Kruskal-Wallis test: pՅ0.001). Tryptophan ingested at breakfast is very important for children to keep a morning-type diurnal rhythm, high quality of sleep, and indirectly good mental health, presumably, through the metabolism of tryptophan to serotonin in daytime and further to melatonin at night.

No abstract

Uncovering grain-scale mechanisms that underlie the disorder–order transition in assemblies of dissipative, athermal particles is a fundamental problem with technological relevance. To date, the study of granular crystallization has mainly focussed on the symmetry of crystalline patterns while their emergence and growth from irregular clusters of grains remains largely unexplored. Here crystallization of three-dimensional packings of frictional spheres is studied at the grain-scale using X-ray tomography and persistent homology. The latter produces a map of the topological configurations of grains within static partially crystallized packings. Using numerical simulations, we show that similar maps are measured dynamically during the melting of a perfect crystal. This map encodes new information on the formation process of tetrahedral and octahedral pores, the building blocks of perfect crystals. Four key formation mechanisms of these pores reproduce the main changes of the map during crystallization and provide continuous deformation pathways representative of the crystallization dynamics.

The relationship of meal habits and alcohol/ cigarette consumption to circadian typology and sleep health in Japanese female students was studied from an epidemiological point of view. Questionnaires on Morningness-Eveningness by Torsvall and Åkerstedt (1980), sleep habits, regularity of meal intake and meal amount, and style of alcohol and cigarette consumption were administered to 800 students aged 18-29 years, attending university or training schools for nutrition specialists (Aichi Prefecture, 35°N). Points from ten questions were totaled to provide estimates of sleep habits given as the Unhealthy Sleep Index (UHSI). The average and standard deviation of Morningness-Eveningness scores were 16.07Ϯ3.53. Students who had breakfast at regular times showed significantly higher Morningness-Eveningness scores than those who ate at irregular times. Based on an integrated analysis (ANOVA) on the effect of regularity of breakfast intake on sleep health, regular breakfast intake may link to sleep health positively via the shifting to morning-type (i.e., the phase-advance of the circadian clock). However, a similar analysis promoted the hypothesis that alcohol consumption and cigarette smoking relate to sleep health negatively and directly, rather than via the shifting to evening-type (i.e., the phase-delaying of the circadian clock). In the case of young women, getting a good quality and quantity of sleep in normal life seems to be important for promoting their mental health, which may fluctuate throughout the menstruation cycle accompanied by mental symptoms as a part of premenstrual syndrome.

We examined the effect of home bedtime discipline during childhood on morningness and eveningness (M-E) preference by Japanese junior high school students. M-E was assessed by the M-E Questionnaire (MEQ) of Torsvall and Akerstedt (the higher the score, the greater the preference for morningness), and parental determination of bedtime during childhood was ascertained using an original questionnaire. The average M-E score of adolescents living in urban Kochi City (mean +/- SD; 15.10 +/- 3.42) was significantly lower (P < .01) than the score of those in suburban districts (16.14 +/- 3.44). Overall, 43.1% of the junior high school students in Kochi City compared to 53.0% of the students living in suburban districts had their bedtime decided during childhood by parents (P < .01). In Kochi City, the M-E score for boys (14.62 +/- 3.51) was lower (P < .01) than girls (15.53 +/- 3.28). During childhood, parents decided the bedtime for 49% of the girls compared to 36.6% of the boys (P < .01). Boys whose bedtime was not decided by parents during childhood had a somewhat stronger preference for eveningness (14.20 +/- 3.53) (P < .05) compared to those whose bedtime was decided by parents (15.12 +/- 3.36). The results suggest bedtime discipline at home during childhood has an effect on adolescent chronotype, modulating the extent of shift to evening ness in Japanese junior high school boys in particular.