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Previous work has shown that exposure to a high fat diet dysregulates the protein degradation process in the hypothalamus of male rodents. However, whether this occurs in a sex-independent manner is unknown. The objective of this study was to determine the effects of a short-term obesogenic diet on the ubiquitin-proteasome mediated protein degradation process in the hypothalamus of female rats. We fed young adult female rats a high fat diet or standard rat chow for 7 weeks. At the end of the 7th week, animals were euthanized and hypothalamus nuclear and cytoplasmic fractions were collected. Proteasome activity and degradation-specific (K48) ubiquitin signaling were assessed. Additionally, we transfected female rats with CRISPR-dCas9-VP64 plasmids in the hypothalamus prior to exposure to the high fat diet in order to increase proteasome activity and determine the role of reduced proteasome function on weight gain from the obesogenic diet. We found that across the diet period, females gained weight significantly faster on the high fat diet than controls and showed dynamic downregulation of proteasome activity, decreases in proteasome subunit expression and an accumulation of degradation-specific K48 polyubiquitinated proteins in the hypothalamus. Notably, while our CRISPR-dCas9 manipulation was able to selectively increase some forms of proteasome activity, it was unable to prevent diet-induced proteasome downregulation or abnormal weight gain. Collectively, these results reveal that acute exposure to an obesogenic diet causes reductions in the protein degradation process in the hypothalamus of females. [ABSTRACT FROM AUTHOR]

Rates of mental illness among Canadian medical students are higher than age-, gender-, and education-matched peers. One predictor of mental health is physical activity; though the relationship between different intensities of physical activity and mental health has not been investigated in medical students. The purpose of this study was to examine relationships between physical activity and mental health profiles in a sample of Canadian medical students. A total of N = 125 students completed an online survey. Latent profile analysis was performed to identify distinct profiles using four continuous latent profile indicators (emotional well-being, social well-being, psychological well-being,resilience). Three mental health profiles emerged, showing low (n = 18), moderate (n = 72) and high (n = 36) self-reported ratings of mental health. The classification quality was good (entropy = 0.81). Individuals in the high mental health profile engaged in more mild physical activity (M = 144.28 mins/week; SD = 22.12) and less moderate-to-vigorous physical activity (M = 195.86 mins/week; SD = 25.67) compared to students in the moderate and low profiles, though not significantly. This suggests that mild physical activity might be the most effective intensity in supporting mental health among medical students, though further research is recommended. [ABSTRACT FROM AUTHOR]

Youth sport programme structures and processes can directly influence participation outcomes, including mental health and well-being. Researchers have found that programme quality and basic needs satisfaction foster psychosocial outcomes; however, limited research has examined the mechanisms that facilitate mental health. The purpose of this study was to examine relationships between programme quality, basic needs satisfaction, and mental well-being in competitive youth sport. Youth (N = 160, 89 males, 71 females; Mage = 15.36, SD = 2.50) completed questionnaires at mid-season, with questions related to quality of their sport programming, and at programme end, with questions pertaining to basic needs satisfaction and mental well-being. Structural equation modelling was used to test the direct relationships between programme quality and mental well-being (r =.46, p <.001; model 1) and between basic needs satisfaction and mental well-being (r =.63, p <.001; model 2). Using several fit indices, results showed an adequate fit of both models to the data, suggesting that programme quality significantly predicted basic needs satisfaction and basic needs satisfaction significantly predicted mental well-being. Bootstrapping analysis was used to test if basic needs satisfaction mediated the relationship between programme quality and mental well-being. Results supported mediation, with a large effect (k2 = 0.28). The study findings help to emphasise the value of structuring youth sport programmes to satisfy basic needs, which may have positive implications on youth mental health. This is important because supporting mental well-being at an earlier age may facilitate mental health and well-being in adulthood. [ABSTRACT FROM AUTHOR]

Background: This article presents secondary outcome variables from a randomized controlled trial evaluating the efficacy of two guided self-help interventions for the treatment of depression: behavioral activation (BA) and physical activity (PA). Both interventions resulted in significant reductions in depressive symptoms compared to the wait-list control group, however the mechanisms by which these interventions influenced depression were not presented. Purpose: The purpose of this paper was to compare changes in secondary outcome variables to gain insight into the mechanisms by which reactivation interventions reduce depressive symptoms. Results: Mixed-model analysis of variances (ANOVAs) revealed significant increases in life satisfaction (Main effect: F(3, 91.71) = 4.63, p < 0.01) and self-efficacy (Main effect: F(3, 91.32) = 4.05, p < 0.01) as well as significant decreases in negative affect (Main effect: F(2, 75.88) = 5.24, p < 0.01) and loneliness (Main effect: F(2, 71.78) = 7.49, p < 0.01) in both interventions at pre-, mid-, post-intervention and follow-up. The group x time interactions were not significant, suggesting that the PA and BA interventions had comparable effects over time. Conclusion: These findings provide insight into the potential mechanisms underlying the effectiveness of guided self-help PA and BA interventions on depressive symptoms. [ABSTRACT FROM AUTHOR]

Behavioural activation and physical activity have received empirical support that highlight their efficacy in reducing depression. Even though both behavioural activation and physical activity share the common goal of reactivating the individual, limited research has directly compared these interventions, and more research is required to evaluate their efficacy when offered in low-intensity formats. The present study involves a randomized controlled clinical trial comparing the efficacy of two guided self-help interventions for the treatment of depression: behavioural activation and physical activity. Fifty-nine participants presenting mild-to-moderate symptoms of depression were randomized either to a behavioural activation intervention (n = 20), a physical activity intervention (n = 19) or a wait-list control group (n = 20). All participants completed symptom measure pre-, mid- and post-intervention, as well as at a two-month follow-up. Mixed-model analyses of variance revealed that both interventions were significantly more efficacious in reducing depressive symptoms in comparison with the control group. Physical activity involved significantly less time-investment compared to the behavioural activation condition (less than half the amount of time). These results indicate that physical activity and behavioural activation both effectively reduce depressive symptoms and are favourably applicable in low-intensity formats. Implications of these results and avenues for future research are discussed. [ABSTRACT FROM PUBLISHER]

The Developmental Model of Sport Participation describes three pathways that youth can follow: recreational participation, late specialization and early specialization. Many competitive sport programmes are promoting early specialization in hopes that their athletes will gain an advantage over others; however, research indicates that youth who wait until adolescence to specialize in a given sport may achieve physical and psychological benefits. The purpose of this study was to investigate the psychological effects of sport specialization by examining relationships between youth hockey players’ level of specialization, psychological needs satisfaction (PNS), psychological needs dissatisfaction (PND), mental health and mental illness. Sixty-one youth male hockey players (Mage = 14.90) responded to an online survey. Results indicated that PND according to specialization was significant with early specializers reporting the highest PND and recreational athletes reporting the lowest PND (p = .029), indicating a large effect size (η2 = .157). No other significant differences were found. Bivariate correlations revealed significant relationships between all variables. Moreover, regression analyses showed that PNS positively predicted mental health (β = .47) and negatively predicted mental illness (β = −.51), while PND positively predicted mental illness (β = .71) and negatively predicted mental health (β = −.44). Results suggest that PNS is important to promote mental health and avoid mental illness. Future research is needed to fully understand the psychological consequences of early sport specialization. [ABSTRACT FROM PUBLISHER]