Doshisha University

Mental health problems among children and adolescents have been increasing worldwide, highlighting the need for preventive interventions in schools. This study examined the effectiveness of a school-based universal prevention program on self-efficacy and mental health problems in Japanese children using a quasi-experimental design with intervention and control groups. A total of 1,281 third- and fourth-grade students participated, with 264 assigned to the intervention group and 1,017 to the control group. The intervention group received the Universal Unified Prevention Program for Diverse Disorders (Up2-D2), a 12-session program based on cognitive-behavioral and positive psychological interventions. A significant universal-level effect was found for positive attitude (a self-efficacy subscale), which improved over time in the intervention group but not in the control group. At the indicated level, a Time × Group interaction was observed for depressive symptoms among children with elevated baseline depression; however, the group effect at Time 4 did not reach statistical significance after covariate adjustment. Effect sizes at Time 4 were small for positive attitude at the universal level (g = 0.19) and small-to-moderate for depressive symptoms at the indicated level (g = 0.36). These findings suggest that Up2-D2 may promote positive attitude at the universal level, while potential indicated-level benefits for depressive symptoms may warrant further confirmation. Evaluating outcomes in both general and at-risk subgroups may help clarify for whom and on which outcomes universal school-based prevention programs are most beneficial.

Abstract In representative democracies, members of a legislative body formulate public policies. To secure an extension of their tenure, they must convince voters that they deserve another term. In this study, we investigate whether the adage “speech is silver, silence is golden” applies to elected officials by examining the relationship between legislators’ speaking records in the assembly and their performance in re-election campaigns. The speech data are drawn from local assembly transcripts spanning 2000–2023 in a Japanese city with typical Japanese demographic characteristics. Our analysis reveals a positive correlation between incumbents’ statements in the legislature and vote share during re-election (relative to their previous electoral performance). We also find that the impact of speech strengthens in the second half of their tenure, particularly as the next election approaches. These results suggest that while speech may indeed be silver, silence is not golden among politicians in representative democracies.

IntroductionThis study examined whether fatigue mediates the association between sleep debt and depressive symptoms among municipal employees in Japan.MethodsThis cross-sectional study was conducted as part of the Night in Japan Home Sleep Monitoring Study (NinJaSleep Study) between November 2023 and March 2024 among 1,435 municipal employees in Koka City, Japan. Sleep debt was quantified using the Sleep Debt Index, calculated from self-reported ideal and actual sleep duration. Depressive symptoms were assessed using the Patient Health Questionnaire-9 (PHQ-9), and fatigue was assessed using the Chalder Fatigue Scale. Mediation analysis was performed using the PROCESS macro (Model 4), adjusting for age, sex, body mass index, and occupation. Indirect effects were estimated using bootstrapping with 5,000 resamples.ResultsSleep debt was significantly associated with higher fatigue scores (B = 2.37, p < 0.001), and fatigue was positively associated with depressive symptoms (B = 0.32, p < 0.001). The direct association between sleep debt and depressive symptoms was not statistically significant (B = 0.07, p = 0.36). Mediation analysis indicated that the association between sleep debt and depressive symptoms was significantly mediated by fatigue (indirect effect: B = 0.76, 95% CI: 0.61–0.91).DiscussionSleep debt is associated with depressive symptoms primarily through increased fatigue. These findings highlight fatigue as a key pathway in linking insufficient sleep to mental health outcomes and underscore the importance of addressing fatigue in workplace mental health strategies.

Max-plus algebra is a semiring with two operations: addition ⊕:=max and multiplication ⊗:=+ . The definition of the max-plus algebraic determinant is equivalent to the assignment problem on a bipartite graph. %This study presents a new expression of the max-plus algebraic determinant. Since the assignment problem has a formulation as linear programming, the duality theorem induces the minimization problem that attains the same optimal value as the assignment problem. We translate this dual problem in terms of max-plus algebraic operation and obtain another expression for the max-plus algebraic determinant. For the determinant of the product of max-plus square matrices, we have only the inequality det(P⊗Q)≥detP⊗detQ , and a known sufficient condition for the equality is given by the condition for det(P⊗Q) . Exploiting the duality theorem for the determinant, we derive a necessary and sufficient condition for the equality. Our criterion only needs the optimal assignments corresponding to detP and detQ but does not require to compute det(P⊗Q) beforehand.

This study investigates how dynamic psychological mechanisms—particularly self-efficacy—can enhance user engagement in community-based digital systems. We combine a multi-agent simulation and a 121-day field experiment to compare system designs with and without psychological adaptation. In the simulation, agents with adaptive self-efficacy formed larger social networks and exhibited more gift-giving behavior. In the real-world setting, three staged interventions—a gift reimbursement scheme, social rankings, and a step prediction contest—were introduced to stimulate motivation. Results show that while the effect of extrinsic incentives declined over time, user participation remained stable, suggesting partial internalization of motivation. The study provides empirical evidence for integrating psychological constructs into digital community design and offers a framework for measuring motivational impact beyond short-term reward effects.

Abstract This study examines the effects of compact city policies on land prices.Using Toyama City, Japan, as a case study, we apply a difference-indifferencesapproach to district-level panel data of official land prices from2001 to 2025. The results reveal that residence-encouraged zones experiencedsignificant land price appreciation after the implementation ofcompact city policies. Rising land prices expanded the property and cityplanning tax bases, contributing to the city’s fiscal stabilization. Thefindings suggest that compact city policies can reorganize urban spatialstructures as well as enhance fiscal sustainability—an outcome conceptualizedas “urban management.” This study provides new empirical evidencethat compact city strategies in shrinking cities can generate bothspatial and fiscal benefits, thereby offering practical implications for sustainableurban planning and local governance. However, there are someresearch limitations: the study does not consider the balance of expenditureand revenue, the time range of the policy, or the micro-level behaviorof households or developers. JEL code: R14, R38, R51, C23, H71

BackgroundThis study aimed to elucidate the relationships of psychological flexibility (PF) patterns in patients with type 2 diabetes mellitus with physiological and lifestyle indexes.MethodsThe study recruited 223 inpatients and outpatients for the survey. It focused on levels of experiential avoidance (EA) and subgroups of comprehensive PF patterns. The differences in self-care behavior and medical condition between high- and low-EA groups were examined using t-test or Wilcoxon’s rank sum test. Furthermore, ANOVA or Kruskal–Wallis test was conducted to depict group features after applying cluster analysis to extract PF patterns.ResultsAnalyses revealed that low-EA patients exhibited better conditions. A subsequent cluster analysis extracted three subgroups: flexible, inaction, and entangled. The distinguishing characteristics were manifested in the patterns of fusion, values, and commitment. In general, the flexible subgroup exhibited optimal conditions that align with those reported in previous studies and theoretical assumptions of acceptance and commitment therapy.ConclusionConsidering these findings and their commonality with previous research, the study recommended that assessments focusing on processes—specifically cognitive fusion, and values and commitment, in addition to EA—may yield valuable insights for healthcare providers and emphasize the potential utility of a tiered intervention guide that first targets fusion, followed by values and commitment.Trial registrationNot applicable.