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5,392 result(s) for "Gu, Song"
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A serial mediation model of physical exercise and loneliness: the role of frailty and depression
Background Frailty, depression, and loneliness are significant risk factors that hinder successful aging. Physical exercise has been widely recognized as an effective intervention to improve both the physical and mental health of older adults. Guided by the integral conceptual model of frailty, this study aimed to explore the relationships among physical exercise, frailty, depression, and loneliness, providing theoretical support for designing targeted exercise interventions to alleviate loneliness in older adults. Methods This study employed a structural equation model (SEM) and bootstrap method to examine a serial mediation model, investigating the roles of frailty and depression in the relationship between physical exercise and loneliness. A descriptive and cross-sectional design was adopted, and data were collected from 505 older adults aged 60 and above in China between February and July 2023. The data were collected using the Physical Activity Rating Scale (PARS-3), the UCLA Loneliness Scale (ULS-8), the Tilburg Frailty Indicator (TFI) and the Patient Health Questionnaire-9 (PHQ-9). Results The findings revealed a significant direct negative relationship between physical exercise and loneliness (Effect = -0.063, 95% CI: -0.085 to -0.040). Furthermore, frailty and depression were found to mediate this relationship both independently and serially. The independent mediation effect of frailty was − 0.072 (95% CI: -0.090 to -0.055), while the independent mediation effect of depression was − 0.010 (95% CI: -0.019 to -0.003). The serial mediation effect of frailty and depression was − 0.007 (95% CI: -0.011 to -0.002). Collectively, the total indirect effect of the three mediation pathways accounted for 58.55% of the observed relationship. Conclusions This study demonstrated a negative correlation between physical exercise and loneliness among older adults, with frailty and depression serving as significant mediators in this relationship. The findings suggest that physical exercise may alleviate loneliness in older adults by enhancing physiological function and fostering psychosocial empowermen.
A machine learning model the prediction of athlete engagement based on cohesion, passion and mental toughness
Athlete engagement is influenced by several factors, including cohesion, passion and mental toughness. Machine learning methods are frequently employed to construct predictive models as a result of their high efficiency. In order to comprehend the effects of cohesion, passion and mental toughness on athlete engagement, this study utilizes the relevant methods of machine learning to construct a prediction model, so as to find the intrinsic connection between them. The construction and comparison methods of predictive models by machine learning algorithms are investigated to evaluate the level of predictive models in order to determine the optimal predictive model. The results show that the PSO-SVR model performs best in predicting athlete engagement, with a prediction accuracy of 0.9262, along with low RMSE (0.1227), MSE (0.0146) and MAE (0.0656). The prediction accuracy of the PSO-SVR model exhibits an obvious advantage. This advantage is mainly attributed to its strong generalization ability, nonlinear processing ability, and the ability to optimize and adapt to the feature space. Particularly noteworthy is that the PSO-SVR model reduces the RMSE (7.54%), MSE (17.05%), and MAE (3.53%) significantly, while improves the R 2 (1.69%), when compared to advanced algorithms such as SWO. These results indicate that the PSO-SVR model not only improves the accuracy of prediction, but also enhances the reliability of the model, making it a powerful tool for predicting athlete engagement. In summary, this study not only provides a new perspective for understanding athlete engagement, but also provides important practical guidance for improving athlete engagement and overall performance. By adopting the PSO-SVR model, we can more accurately identify and optimise the key factors affecting athlete engagement, thus bringing far-reaching implications for research and practice in sport science and related fields.
Association between coach-athlete relationship and athlete engagement in Chinese team sports: The mediating effect of thriving
Coach-athlete relationship (CAR), thriving and athlete engagement are important psychological variables that affect sports performance. On the basis of self-determination theory, this study constructs a mediation model to examine the influence of CAR on athlete engagement and the mediating effect of thriving between them. This cross-sectional study involves a questionnaire survey with 287 Chinese active athletes (M = 19.63, SD = 2.53) aged 14-26 years (64.5% male, 35.5% female) from eight sports. CAR, thriving and athlete engagement were assessed using the CAR Questionnaire, the Thriving Scale, and the Athlete Engagement Questionnaire, respectively. CAR and its dimensions can significantly and positively predict athlete engagement, complementarity, commitment, and closeness, accounting for 35.1%, 34.6%, and 30.4% of the cumulative variance in dominance analysis, respectively. The direct and indirect paths show that CAR affects athlete engagement through the mediating effect of thriving. The mediating effect model has a good fit and indirect effects account for 56.9% of the total effects. The effect of CAR on athlete engagement reflects a practical application of interpersonal dynamics in competitive sports to a certain extent. The following suggestions can be used to improve athlete engagement. First, setting common goals, emphasizing mutual cooperation, and building trust and support, promote coaches and athletes to have a higher sense of commitment and complementarity to each other, thereby helping improve athlete engagement. Second, meeting the vitality and progress needs of athletes effectively mobilizes CAR resources to promote athlete engagement, which can be manipulated by cultivating closeness, commitment, and complementarity. Third, to ensure the athletes' sports state and mental health, the sports team should focus on the cultivation of athletes' capacities to thrive and internally form a dynamic and positive sports atmosphere in their team. In the future, we can track and compare the influence of the improvement of CAR on thriving and athlete engagement can be tracked and compared from the dual perspectives of coaches and athletes.
Intragroup and Intergroup Pairwise Key Predistribution for Wireless Sensor Networks
The major task of a wireless sensor network (WSN) is data collection. Key predistribution (KP) is to establish pairwise keys for secure communication in a WSN, such that all collected data could be securely sent to a backend database. Most research on KP-like schemes is dedicated to enhancing resiliency against node capture attack (NA) and retaining the link connectivity in the meantime. For large-scale wireless sensor networks, a more common approach is to use a multiple-sink WSN (MWSN) to support a large number of sensor nodes. In MWSNs, there are different clusters (referred to as groups). We took the lead in studying KP in the MWSN environment. Based on the new MWSN environment, we present intragroup and intergroup KP (I2KP) to fulfill both requirements of security and energy efficiency when gathering data via various sink nodes in a large-scale WSN. Three types of I2KP with respective pros and cons are proposed. Theoretical analysis and numerical simulation demonstrate their effectiveness.
A serial mediation model of physical exercise and loneliness: the role of perceived social support and resilience
Background Loneliness is a risk factor for numerous negative life outcomes and diseases among older adults. Physical exercise can reduce social isolation among older adults and improve their health status. This study focused on the relationships among physical exercise, perceived social support, resilience and loneliness to provide theoretical support for physical exercise interventions to address loneliness in older adults. Methods This study used a structural equation model and bootstrap method to test a serial mediation model of physical exercise and loneliness and the role of perceived social support and resilience. In this descriptive and cross-sectional study, a questionnaire survey was conducted on 516 older adults from 5 January 2024 to 20 January 2024. The data were collected using the physical activity rating scale (PARS-3), UCLA loneliness Scale-8 (ULS-8), perceived social support scale (PSSS) and Connor-Davidson Resilience Scale (CD-RISC). Results The results showed that physical exercise among older adults had a direct negative relationship with loneliness (Effect = -0.049, 95% CI: -0.072 to -0.027). In addition, perceived social support and resilience mediated the relationship between physical exercise and loneliness both independent and serially, with the independent mediation effect of perceived social support being − 0.041 (95% CI: -0.056 to -0.028), the independent mediation effect of resilience being − 0.018 (95% CI: -0.026 to -0.011), and the serial mediation effect of perceived social support and resilience being − 0.009 (95% CI: -0.015 to -0.005). The total indirect effect of the three mediation paths was 58.47%. Conclusions (1) In this study, physical exercise and loneliness in older adults were negatively correlated. Perceived social support and resilience play mediating roles in the relationship between physical exercise and loneliness. (2) This study suggests that participation in group events or team sports is valuable for alleviating loneliness caused by a lack of social interaction.
Frictional resistance calculation and jacking force prediction of rectangular pipe jacking
In practical engineering, whilst estimating the jacking force of rectangular pipe jacking using an empirical formula, the results obtained from said formula deviate from reality and manifest inadequate engineering guidance. The equations governing the applied force during the installation of rectangular pipe jacking have been derived for various contact states involving the interaction between the pipe, slurry, and soil. The distinct stress conditions in the pipe jacking process as well as the shear-friction mechanism between the pipe and the surrounding soil have been taken into account. The displacement control method is introduced to simulate the pipe–slurry–soil contact friction during the pipe jacking process in FLAC 3D . Additionally, the pipe jacking behavior, pipe–slurry–soil contact frictional force, and variation law of the jacking force are also simulated. Mutual verification was carried out using the results obtained from field monitoring, numerical and theoretical. The findings are as follows: the established equations for calculating pipe jacking force are highly applicable across various conditions of pipe–slurry–soil contact, and the outcomes derived from theoretical formulas align remarkably well with those obtained through field monitoring and numerical simulation. During the jacking process, the sidewalls exhibit initial partial sliding followed by a complete movement as the jacking force intensifies and subsequently diminishes, eventually attaining stability during the behavior adjustment phase. Moreover, the bottom pipe–soil contact is the most common situation in actual construction.
m6A mRNA methylation regulates CTNNB1 to promote the proliferation of hepatoblastoma
Background N 6 -Methyladenosine (m 6 A) modification has been implicated in many biological processes. It is important for the regulation of messenger RNA (mRNA) stability, splicing, and translation. However, its role in cancer has not been studied in detail. Here we investigated the biological role and underlying mechanism of m 6 A modification in hepatoblastoma (HB). Methods We used Reverse transcription quantitative real-time PCR (RT-qPCR) and Western blotting to determine the expression of m 6 A related factors. And we clarified the effects of these factors on HB cells using cell proliferation assay, colony formation, apoptotic assay. Then we investigated of methyltransferase-like 13 (METTL3) and its correlation with clinicopathological features and used xenograft experiment to check METTL3 effect in vivo. m 6 A-Seq was used to profiled m 6 A transcriptome-wide in hepatoblastoma tumor tissue and normal tissue. Finally, methylated RNA immunoprecipitation (MeRIP) assay, RNA remaining assay to perform the regulator mechanism of MEETL3 on the target CTNNB1 in HB. Results In this research, we discovered that m 6 A modifications are increased in hepatoblastoma, and METTL3 is the main factor involved with aberrant m 6 A modification. We also profiled m 6 A across the whole transcriptome in hepatoblastoma tumor tissues and normal tissues. Our findings suggest that m 6 A is highly expressed in hepatoblastoma tumors. Also, m 6 A is enriched not only around the stop codon, but also around the coding sequence (CDS) region. Gene ontology analysis indicates that m 6 A mRNA methylation contributes significantly to regulate the Wnt/β-catenin pathway. Reduced m 6 A methylation can lead to a decrease in expression and stability of the CTNNB1. Conclusion Overall our findings suggest enhanced m 6 A mRNA methylation as an oncogenic mechanism in hepatoblastoma, METTL3 is significantly up-regulated in HB and promotes HB development. And identify CTNNB1 as a regulator of METTL3 guided m 6 A modification in HB.
Regulated ATP release from astrocytes through lysosome exocytosis
Release of ATP from astrocytes is required for Ca 2+ wave propagation among astrocytes 1 , 2 , 3 and for feedback modulation of synaptic functions 2 , 4 , 5 . However, the mechanism of ATP release and the source of ATP in astrocytes are still not known. Here we show that incubation of astrocytes with FM dyes leads to selective labelling of lysosomes. Time-lapse confocal imaging of FM dye-labelled fluorescent puncta, together with extracellular quenching and total-internal-reflection fluorescence microscopy (TIRFM), demonstrated directly that extracellular ATP or glutamate induced partial exocytosis of lysosomes, whereas an ischaemic insult with potassium cyanide induced both partial and full exocytosis of these organelles. We found that lysosomes contain abundant ATP, which could be released in a stimulus-dependent manner. Selective lysis of lysosomes abolished both ATP release and Ca 2+ wave propagation among astrocytes, implicating physiological and pathological functions of regulated lysosome exocytosis in these cells.
Effects of five types of exercise on vascular function in postmenopausal women: a network meta-analysis and systematic review of 32 randomized controlled trials
As women age, especially after menopause, cardiovascular disease (CVD) prevalence rises, posing a significant global health concern. Regular exercise can mitigate CVD risks by improving blood pressure and lipid levels in postmenopausal women. Yet, the optimal exercise modality for enhancing vascular structure and function in this demographic remains uncertain. This study aims to compare five exercise forms to discern the most effective interventions for reducing cardiovascular risk in postmenopausal women. The study searched PubMed, Web of Science, Cochrane, EBSCO, and Embase databases. It conducted a network meta-analysis (NMA) of randomized controlled trials (RCTs) on five exercise interventions: continuous endurance training (CET), interval training (INT), resistance training (RT), aerobic combined with resistance training (CT), and hybrid-type training (HYB). Outcome measures included carotid artery intima-media thickness (IMT), nitric oxide (NO), augmentation index (AIx), pulse wave velocity (PWV), and flow-mediated dilatation (FMD) of the brachial artery. Eligible studies were assessed for bias using the Cochrane tool. A frequentist random-effects NMA was employed to rank exercise effects, calculating standardized mean differences (SMDs) with 95% confidence intervals (CIs). The analysis of 32 studies ( = 1,427) indicates significant increases in FMD with CET, INT, RT, and HYB in postmenopausal women. Reductions in PWV were significant with CET, INT, RT, CT, and HYB. AIx decreased significantly with INT and HYB. CET, INT, and CT significantly increased NO levels. However, no significant reduction in IMT was observed. SUCRA probabilities show INT as most effective for increasing FMD, CT for reducing PWV, INT for decreasing AIx, CT for lowering IMT, and INT for increasing NO in postmenopausal women. The study demonstrates that CET, INT, RT, and HYB have a significant positive impact on FMD in postmenopausal women. Furthermore, all five forms of exercise significantly enhance PWV in this population. INT and HYB were found to have a significant positive effect on AIx in postmenopausal women, while CET, INT, and CT were found to significantly improve NO levels. For improving vascular function in postmenopausal women, it is recommended to prioritize INT and CT exercise modalities. On the other hand, as CET and RT were not ranked at the top of the Sucra value ranking in this study and were less effective than INT and CT as exercise interventions to improve vascular function in postmenopausal women, it is not recommended that CET and RT be considered the preferred exercise modality.
Relationships among Sports Group Cohesion, Passion, and Mental Toughness in Chinese Team Sports Athletes
Background: Passion is an important motivational variable that profoundly affects athletes’ cognition, emotion, and behavior. This study constructed a mediating model to explore the mechanism of cohesion toward passion and mental toughness of Chinese team sports athletes and to investigate the mediating effect of harmonious passion and obsessive passion on cohesion and mental toughness. Methods: A questionnaire survey was conducted on 326 Chinese active athletes (M = 19.63, SD = 6.51) aged 14–26 years (54% male, 46% female) from eight sports. Results: Cohesion and its dimensions can positively predict athletes’ mental toughness, and ATG-T is more important in advantage analysis. The direct and indirect paths show that cohesion affects mental toughness through the mediating effect of harmonious passion and obsessive passion. Mediating effect model has a good fit and explained 22.1% of the variance in mental toughness. Conclusion: The relationship between cohesion, passion, and mental toughness reflects the psychological dynamic process from environment to motivation to sports performance. The development of team sports athletes’ mental toughness can be carried out from the following points. First, the team should define a sports goal and take the needs of members into account in goal-setting. Second, the sports team should build a team culture that is enterprising, inclusive, and cooperative and emphasizes members’ recognition of them. Third, the team should attach importance to the passion of the members and make good use of the team atmosphere. To protect the psychological health and long-term development of athletes, team culture should pay more attention to the cultivation of athletes’ harmonious passion. Improving cohesion is beneficial to athletes’ mental toughness in team sports. To protect the psychological health and long-term development of athletes, team culture should pay more attention to the cultivation of athletes’ harmonious passion.