Relationship between parents' health literacy and children's sleep problems in Japan.

BACKGROUND: Sleep problems in preschool children can stunt their health and growth. However, the factors that cause sleep problems in children are not well understood. The aim of this study was to determine the relationship between parents' health literacy (HL) and children's sleep problems. The study was conducted at two kindergartens, two nursery schools, and a center for early childhood education in Chitose-city, Hokkaido, Japan. METHOD: This study used a multicenter cross-sectional design. The sample comprised 354 preschoolers (aged 3-6 years) and their parents. In families with two or more children attending the same facility, only the oldest child was asked to participate in the study. Exclusion criteria included participants whose completed questionnaires had missing values. Children's sleep problems were assessed using the Japanese version of the Children's Sleep Habits Questionnaire (CSHQ-J). Parents' HL was assessed using the 14-item Health Literacy Scale (HLS-14). The parents were classified into two groups (high HL group and low HL group). Multiple regression modelling was used to determine the association between HLS-14 and CSHQ-J scores. RESULTS: Of the 354 parents, 255 (72%) were in the high HL group and 99 (28%) in the low HL group. The mean CSHQ-J score was significantly lower in the high HL group than in the low HL group (45.3 ± 6.0 points vs. 46.8 ± 5.9 points, p = 0.043). In multiple regression analyses, parents' HL was independently associated with their CSHQ-J score after adjusting for all confounding factors (adjusted R2 = 0.22, ß = - 0.11; p = 0.043). CONCLUSIONS: Parents' HL appears to affect their children's sleep problems. This finding suggests that parents' HL may be a target for intervention to improve children's sleep problems.

Nitrogen Isotope Fractionation from Ammonia Gas to Ammonium in Particulate Ammonium Chloride.

The nitrogen stable isotope ratios of NH3 gas (δ15N-NH3(g)) and particulate NH4+ (δ15N-NH4+(p)) have been used to determine the sources and elucidate the environmental dynamics of NH3(g) and NH4+(p). Some studies have determined the sources from δ15N-NH4+(p) in the ambient environment by using the nitrogen isotope fractionation value (Δδ15N). Studies of Δδ15N are limited and estimated the Δδ15N by theoretical calculation or laboratory experiments in closed systems. Here, we produced actual submicron-sized particles and exposed them to NH3(g) in a dynamic chamber under various experimental conditions of temperature and NH3(g) turnover rate. Δδ15N was lower when temperature was higher. For low turnover rates (about 0.9 per day), the Δδ15N was 31.6 ± 2.0‰ (mean ± 1SD), almost equal to the Δδ15N from theoretical calculations and laboratory tests in closed systems. Also, the relationship between Δδ15N, the temperature, and the turnover rate can be described in the equation form. This relationship can help to explain the discrepancies between Δδ15N values in closed and open systems. Our results could help to clarify the sources and mechanisms of particle formation.