Dance, as a performance activity, is associated with various problems. Among these challenges, sleep disturbances are notably prevalent. This study aimed to explore the potential relationship between sleep characteristics—specifically chronotype and subjective sleep quality—and psychological inflexibility in dance students. This research adopted a cross-sectional design using non-probabilistic sampling. One hundred and fourteen dance students, with a mean age of 23.87 years, participated in the study. Assessment tools included the Acceptance and Action Questionnaire-II, Pittsburgh Sleep Quality Index, and the Composite Scale of Morningness. The results revealed no gender differences in psychological inflexibility or chronotype, although women report poorer sleep quality. Differences emerged in both subjective sleep quality and chronotype when students were grouped according to low, medium, or high levels of psychological inflexibility. Those with low inflexibility, as opposed to those with high inflexibility, report better sleep quality, with no differences observed between medium and high inflexibility groups. Students with high-medium levels of psychological inflexibility showed a higher risk (OR = 6.373 times higher) of experiencing poor sleep quality compared to those with low psychological inflexibility. In terms of chronotype, the low inflexibility group is inclined to be more of a morning type than the medium and high inflexibility groups, with no differences between the latter two groups. Students categorized as having low inflexibility tend to have a longer history of dancing under the guidance of a teacher and dedicate more hours and days per week to rehearsal. The findings are discussed in terms of their educational implications for dance students.

Abstract: Background: chronotype is generally defined as the variability of the phase angle of en-trainment, while the latter reflects the relationship between the timing of a certain rhythm (e.g., sleep-wake cycle) and the timing of an external temporal cue. Individuals can be placed on a spectrum from "morning types" (M types), to "evening types" (E types). E-chronotype has been proposed as a transdiagnostic risk factor for psychiatric conditions and associated with psycho-pathological dimensions. Eveningness seems correlated with both suicidal ideation (SI) and suicidal behavioral (SB), through several possible mediating factors. Immunological alterations also have been linked to later chronotypes and SI/SB. Objective: This narrative review aims to summarize the evidence supporting the possible association between chronotypes and suicide, with the eventual mediating role of neuroinflammation and several psychopathological dimensions. Material and methods: A search of literature (2003-2023) was conducted, using various databases: PUBMED, EMBASE, Scopus, UpToDate, PsycINFO, Cochrane Library. English-language articles were col-lected and screened for eligibility. Results: Despite the apparent absence of a direct correlation between E-chronotype and suicidality, E-chronotype promotes a chain of effects that could be in-volved in an increased risk of SB, in which with neuroinflammation possibly play an intriguing role and some psychopathological dimensions may stand out.

This paper examines the effect of chronotype on the delinquent credit card payments and stock market participation through preference channels. Using an online survey of 455 individuals who have been working for 3 to 8 years in companies in mainland China, the results reveal that morningness is negatively associated with delinquent credit card payments. Morningness also indirectly predicts delinquent credit card payments through time preference, but this relationship only exists when individuals’ monthly income is at low and average level. On the other hand, financial risk preference accounts for the effect of morningness on stock market participation. Consequently, an additional finding is that morningness is positively associated with financial risk preference, which contradicts previous finding in the literature. Finally, based on the empirical evidence, we discuss the plausible mechanisms that may drive these relationships and the implications for theory and practice. The current study contributes to the literature by examining the links between circadian typology and particular financial behaviours of experienced workers.

Running at odds with the timing imposed by the circadian clock plays an important role in the process that leads to communicable and non communicable diseases. The primary objective of this study was to analyse whether early dinner eater children were at lower risks of acute respiratory infections than late dinner eater children, during the COVID-19 pandemic. Methods: This cross sectional study was conducted from July to December 2020 on children attending Majorcan emergency services. Clinical data collected included timing, symptoms, laboratory tests and imaging studies of current illness. Each diagnosis was validated by general paediatricians. Our survey on dinner time habits was carried out by using self-administered questionnaires. Results: A total of 669 children under age 18 were included in the study. The median of dinner time was 8:30 pm. Late dinner eaters accounted for a higher proportion of acute otitis media than early dinner eaters (7% vs 3%; P=0.028). Other infectious diseases were not associated with dinner time habits. Conclusions: We make a preliminary estimate of the link between late dinner habits and acute otitis media in children. However, no conclusions about causality can be established due to the observational design of the study.

The study examined eating timing, diet, and the ratio of sleep phases in people with social jetlag (SJL). The study involved 83 participants who filled out a questionnaire, and 21 of them took part in the study of sleep phases by electroencephalography during the week. SJL was associated with a higher incidence rate of eating jetlag, eating phase delays, an increase in calorie intake after 9 p.m., a decrease in dietary fiber intake for breakfast, and melatonin-containing product consumption for dinner. Young people with SJL had a reduction in total sleep and light sleep phase duration by 60 and 36 min on work/school days and an increase in total sleep and REM sleep phase duration by 66 and 60 min on weekends, respectively. Young people consuming foods with more than 4234.5 ng of melatonin for dinner, compared with their peers consuming less than 313.2 ng of melatonin, showed a decrease in SJL and sleep debt by 54 and 90 min and an increase in the total sleep and the deep sleep phase duration by 66 and 30 min, respectively. Thus, the consumption of melatonin-containing foods for dinner is associated with a decrease in circadian misalignment and a sleep quality improvement.