Search Results (8,226)

Objective: This study examined the associations between body composition and physical performance in U13 and U15 volleyball players. Methods: A total of 67 female athletes participated, distributed into U13 (n = 35) and U15 (n = 32) categories. Body weight, body fat percentage, skeletal muscle mass (SMM), and body mass index (BMI) were assessed, along with maximal handgrip strength (HGS), Abalakov jump (ABK), and standing long jump (SLJ). Spearman’s rho correlations were calculated by category, with 95% bootstrap confidence intervals based on 5000 resamples and Benjamini–Hochberg adjustment for 24 comparisons. Results: In U13, SMM was associated with HGS (rs = 0.750; q < 0.001), body fat percentage with ABK jump (rs = −0.496; q = 0.020), body weight with handgrip strength (rs = 0.430; q = 0.043), and body mass index with ABK jump (rs = −0.425; q = 0.043). In U15, SMM was associated with HGS (rs = 0.705; q < 0.001), while body fat percentage was associated with ABK jump (rs = −0.437; q = 0.043) and standing long jump (rs = −0.446; q = 0.043). Conclusions: These associations were specific to the variable, test, and age category analyzed and should be considered exploratory. Given the cross-sectional design and sample characteristics, the findings do not support causal inference, individualized training prescriptions, or conclusions that specific body composition profiles optimize physical performance. Longitudinal studies are needed to confirm these findings. Full article

Background/Objectives: Many adolescent athletes fast during Ramadan, similar to adults. However, research on Ramadan fasting during adolescence, a critical period for growth and development, is insufficient. This study aimed to examine changes in nutritional status and sport-specific performance during Ramadan in adolescent volleyball players and to explore whether these changes differed by Ramadan fasting adherence. Methods: This prospective cohort study included 35 male adolescent volleyball players (age: 16.43 ± 1.29 years, height: 1.75 ± 0.07 m, training experience: 6.20 ± 2.13 years) who fasted during Ramadan. Energy and macronutrient intake, anthropometric measurements, and sport-specific performance tests were conducted before, during, and at the end of Ramadan, and biochemical parameters were measured before and at the end of Ramadan. Results: Fat intake decreased during and at the end of Ramadan (1.60 ± 0.16 and 1.52 ± 0.15 g/kg BW, respectively; p = 0.021). Energy and macronutrient intakes were generally consistent with recommended levels, whereas fluid intake remained relatively low (1.60 ± 0.11 L, 1.35 ± 0.09 L, 1.44 ± 0.10 L, respectively). Anthropometric measurements remained unchanged. Left-hand grip strength (p = 0.006), 20 m sprint performance (p < 0.001), and agility performance (p = 0.002) decreased over the study period. Significant group effects were observed for 5 m, 10 m, and 20 m sprint, SJ, and standing long jump performances according to fasting adherence. Chloride, urea, and the BUN/creatinine ratio increased at the end of Ramadan, whereas albumin and potassium remained unchanged. Conclusions: In adolescent male volleyball players, Ramadan fasting may be associated with changes in dietary intake, certain sport-specific performance measures, and biochemical parameters potentially related to hydration status. Full article

Unemployment is known to deteriorate physical health through income loss and psychological stress; yet it remains unclear whether racial health disparities stem from differential vulnerability to joblessness or unequal exposure to it. Using a case-crossover design on National Longitudinal Survey of Youth (NLSY79) data from 1983 to 2018, this case-crossover study accounts for unobserved, time-invariant heterogeneity to examine how unemployment duration influences hypertension risk across Black and non-Black respondents. Descriptive analyses reveal striking structural inequities: Black respondents experience significantly longer unemployment duration. Conditional logit models show that longer unemployment duration markedly increases the odds of a hypertension diagnosis for all individuals, with interaction models confirming that the health penalty per duration unit does not differ significantly by race. Nevertheless, because vulnerability to joblessness is equal across racial groups, the disproportionate exposure of Black individuals to prolonged unemployment translates directly into a higher cumulative incidence of hypertension. These findings demonstrate that racial health disparities in joblessness are driven by unequal exposure to prolonged unemployment, rooted in labor market discrimination, rather than a differential biological or psychological response. Consequently, structural interventions to reduce unemployment exposure can improve overall population health while simultaneously narrowing racial gaps in cardiovascular disease. Full article

This study investigates the influence of thermoelastic deformation on the lubrication performance of a superconducting magnetically assisted turbopump mechanical seal, with particular emphasis on film thickness and leakage. A spiral-groove hydrodynamic lubrication model based on the Reynolds equation and film energy equation is used to calculate the liquid-film load capacity and leakage, while a superconducting magnetic-force model based on the Bean model and electromagnetic finite-element analysis is employed to determine the magnetic-force contribution. The calculated mechanical loads and thermal boundary conditions are subsequently introduced into a thermoelastic finite-element model to obtain the deformation of the rotating and stationary seal rings. The results show that increasing the sealing clearance causes both the superconducting magnetic force and hydrodynamic liquid-film force to decrease nonlinearly. At a fixed clearance, the magnetic force is nearly independent of rotational speed, whereas the liquid-film force increases with increasing speed. The rotating ring exhibits greater deformation than the stationary ring, resulting in a non-parallel, approximately conical seal face. The deformation-induced change in the seal-face geometry is incorporated into the film-thickness model using the minimum and maximum film thicknesses, hmin and hmax. The results show that considering seal-face deformation leads to a smaller predicted minimum film thickness and a larger leakage rate than those obtained from the undeformed model. These findings indicate that thermoelastic deformation should be considered in the lubrication-performance evaluation of superconducting magnetically assisted mechanical seals, particularly under low-speed operating conditions. Full article

Contemporary global tourism is undergoing a structural transformation toward immersive, experiential “diving” modalities, establishing the countryside as a critical axis for constructive and regenerative travel. Despite this shift, academic literature remains bottlenecked by informational fragmentation, routinely prioritizing consumer demand over supply-side operator agency. To resolve this empirical deficit, this study utilizes a qualiquantitative, multi-sited, sequential mixed-methods research design across Europe and Oceania, focusing on agritourism as a significant sub-sector. The empirical findings reveal that while global agritourism is unified by a profound biographical territorial embedding, its operational architecture splits into two polarized configurations. The European Institutionalized Mature Model is highly market-driven, demand-responsive, and insulated by top-down public policy frameworks, yet it is severely constrained by generational succession grids and an aging demographic. In contrast, the Oceanian Decentralized Identity Frontier Model represents a youth-centric, female-dominated structure born of necessity within Small Island Developing States, driven by intrinsic cultural pride but exposed to a complete policy vacuum and severe climate variability. The research diagnoses an advanced sub-specialization training shortfall in Europe regarding environmental and social agriculture, and a foundational corporate capacity deficit in Oceania concerning financial risk hedging, compliance, and direct-to-consumer digital infrastructure. Full article

This essay draws on a delimited corpus of publicly circulating materials associated with Abelardo de la Espriella’s digital campaign in the 2026 Colombian presidential election to examine a form of algorithmic–affective campaigning. Through a qualitative, discursive, and multimodal approach, it examines a core analytical corpus comprising the complete stream with Westcol and six digital posts, supplemented by materials from a broader documentary mapping and journalistic coverage used to contextualize provenance, circulation, and controversies. The central argument holds that the campaign used streaming and generative AI as technological mediations to organize and intensify patriotic and religious language of threat, protection, certainty, belonging, and authenticity. Through the streamed interview with Westcol, a Colombian creator known for gaming content and a large online presence, the campaign staged performative authenticity and proximity through digital codes associated with youth cultures; its use of generative AI contributed to the construction of visual narratives of threat, order, and national salvation. The article develops the notion of the algorithmic homeland and defines it as an imaginary of the nation represented as a threatened, morally ordered community in need of protection, configured through platform infrastructures, media formats, and affective languages. This concept makes it possible to interpret a form of electoral legitimacy construction in which technological mediation and affective languages jointly participate in the production of visibility, proximity, and authority within platform democracy. Full article

Background: Cannabis is the most widely used illicit substance, particularly among youth. Earlier onset is associated with poorer clinical trajectories in cannabis use disorder (CUD), but its relationship with hedonic–motivational components remains unclear. Methods: Outpatients with severe CUD (n = 121) were stratified by age at onset (<18 vs. ≥18 years) and compared on hedonic–motivational functioning using the Snaith–Hamilton Pleasure Scale (SHAPS) and the Temporal Experience of Pleasure Scale (TEPS). Healthy subjects (n = 112) served as a reference group. Results: CUD groups were comparable in clinical characteristics and cannabis use patterns. TEPS-Anticipatory scores were lower in patients with onset before age 18 (p < 0.001) and remained associated with onset group after adjustment for gender, education, and CUD duration (p < 0.001). When healthy subjects were included, significant group effects were observed (p < 0.001). Post hoc comparisons confirmed reduced TEPS-Anticipatory scores in early-onset vs. both later-onset and control groups, and higher SHAPS scores in both CUD groups vs. controls. Conclusions: CUD onset before age 18 is associated with reduced anticipatory pleasure, suggesting a greater involvement of anticipatory than other dimensions of hedonic functioning. Age at onset may therefore help identify patients with greater motivational vulnerability and inform early, targeted prevention and intervention strategies. Full article

This study examined chosen pronoun affirmation across multiple social contexts (i.e., home, online school, in-person school, work, friends, and extended family) as a predictor of mental health among 319 trans and nonbinary (TNB) youth (ages: 13–22; M_age = 18.6, SD = 2.18). Pronoun affirmation is increasingly restricted, particularly in schools, as part of widespread anti-trans legislation in the U.S. Guided by an integration of resilience, minority stress, and intersectionality frameworks, this study used a person-centered approach (i.e., latent class analysis), identifying three distinct affirmation classes: predominantly friends affirmation (27.3%), non-familial affirmation (55.8%), and comprehensive affirmation (16.9%). Transmasculine youth were more likely to be represented in comprehensive affirmation, while nonbinary youth were less likely to be represented in the comprehensive affirmation class. Compared to youth in the predominantly friends affirmation class, youth in non-familial affirmation and comprehensive affirmation classes reported significantly lower depressive and anxiety symptoms, better future outlook, and lower odds of suicide thoughts. In variable-centered analyses, home affirmation was associated with fewer depressive and anxiety symptoms, online and in-person school affirmation was associated with all outcomes except suicide attempts, friend affirmation was similarly associated with all outcomes except suicide thoughts and attempts, and extended family affirmation was associated with lower depressive and anxiety symptoms and lower odds of suicide thoughts. Findings underscore the importance of pronoun affirmation across institutional, peer, and family contexts and carry direct implications for school policy, family-based interventions, and advocacy amid increasing legislative restrictions on gender-affirming practices. Full article

Background/Objectives: Family circumstances are related to children’s physical activity and fitness, yet the two are rarely examined together in the same children. We examined how socioeconomic position and family structure (only-child status) relate to domain-specific reported activity and measured fitness. Socioeconomic position was the mean of maternal and paternal educational attainment, with higher values indicating higher attainment. Methods: We designed and conducted a cross-sectional survey of 8228 children in grades 1 to 9 from 27 schools. The questionnaire covered the preceding six months in three domains: physical education class, in-school extracurricular activity and out-of-school exercise. Weekly frequency, duration and intensity were reported for each and summed to weekly moderate-to-vigorous activity (MVPA). Fitness comprised 10 device-measured indicators and, in primary grades, a 5-item motor battery. Linear and logistic models used school fixed effects and school-clustered standard errors, with Benjamini–Hochberg correction. Results: Median reported weekly MVPA was 300 min; 26.3% of the 7533 children with computable MVPA met the 60 min-per-day guideline. Socioeconomic position was associated with reported MVPA (0.077 SD, 95% CI 0.032 to 0.122) and with meeting the guideline (odds ratio 1.21, 95% CI 1.07 to 1.37). The association appeared in out-of-school exercise but not in physical education class, a contrast of 0.064 SD (95% CI 0.024 to 0.104). Socioeconomic position was also associated with lower handgrip strength (−0.044 SD, 95% CI −0.064 to −0.024) and with more sit-ups in primary grades. Only children showed no clear difference in reported activity in any domain, yet they had lower composite fitness (−0.102 SD, 95% CI −0.142 to −0.061), which remained after adjustment for reported MVPA. Conclusions: The socioeconomic gradient in reported activity was concentrated outside the physical education class; family structure was associated with measured fitness without a matching difference in reported activity. Full article

Family functioning is central to youth adaptation, yet brief measures require validation across informants and clinical contexts. This study evaluated the Hungarian 12-item Family Assessment Device–General Functioning Scale (FAD-GF) and the three-item Brief Assessment of Family Functioning Scale (BAFFS) in 562 respondents from 213 families of adolescents with autism spectrum disorder (ASD), anorexia nervosa (AN), or diabetes mellitus (DM). Analyses included cluster-adjusted ordinal confirmatory and multigroup CFA, exploratory factor and general-factor analyses, internal-consistency estimation, and cluster-robust external-association tests. Prespecified FAD-GF models showed inadequate fit, but exploratory analyses indicated a dominant general factor accompanied by recurring local dependencies. An exploratory one-factor model with seven simultaneously estimated residual covariances showed broadly acceptable fit (CFI = 0.962, TLI = 0.946, RMSEA = 0.078, SRMR = 0.034). Internal consistency was high for the FAD-GF (α = 0.893, ωT = 0.896) and acceptable for the BAFFS (α = 0.747, ωT = 0.756). The FAD-GF supported partial scalar invariance across parents and adolescents, strict invariance across fathers and mothers, and scalar but not strict invariance across ASD and AN parents. The BAFFS supported scalar but not strict invariance across fathers and mothers and metric but not scalar invariance across ASD and AN parents; adolescent-group solutions were inadmissible, and its just-identified CFA could not test unidimensionality. Both scales showed expected associations with stress, well-being, relationship satisfaction, and coping. The findings support use of the FAD-GF total score, whereas the BAFFS is better retained as a brief observed index, particularly in parental reports, pending further cross-group validation. Full article

Background: Six-strand flexor tendon repairs offer superior biomechanical strength, yet commonly used techniques often require looped sutures or proprietary materials that limit global accessibility. The Elsaftawy repair technique was developed as a six-strand construct using universally available braided polyester, aiming to provide high strength without reliance on specialty sutures. Methods: Sixty porcine digital flexor tendons were randomized into four groups: Elsaftawy 6-strand, Jin Bo Tang 6-strand, FiberLoop^®, and modified Kessler 4-strand. Core repairs only were performed by a single experienced surgeon. Tendons were biomechanically tested for 2 mm gap formation force, ultimate tensile strength, suturing time, and failure mechanism. Results: All 60 tendons completed biomechanical testing without specimen loss. The Elsaftawy and Jin Bo Tang repairs demonstrated comparable biomechanical performance and significantly greater resistance to 2 mm gap formation and ultimate tensile strength than the Kessler repair (p < 0.05). FiberLoop^® showed significantly lower gap resistance and ultimate load compared with both six-strand techniques but did not differ significantly from the Kessler repair. FiberLoop^® was the fastest technique to perform (p < 0.05), whereas Elsaftawy and Jin Bo Tang repairs failed predominantly by suture rupture, in contrast to the pullout-dominant failure pattern observed with FiberLoop^®. Conclusions: The Elsaftawy repair uses an accessible suture and showed no statistically significant differences in the measured biomechanical outcomes compared with the Jin Bo Tang technique. Its initial mechanical performance and use of standard non-looped sutures support further investigation, including assessment of reproducibility across surgeons and clinical outcomes. Full article

This study explored how rural youth cluster into physical activity (PA) profiles and whether psychological characteristics differ across these clusters. The primary objective was to identify PA-based profiles, and the secondary objective was to examine the differences in basic psychological needs across profiles. A 1-year exploratory prospective cohort study was conducted with 83 6th–8th grade students from an under-resourced rural middle school, with 48 participants having complete PA data for analyses. The sport-based PA intervention was implemented by college students in an undergraduate service-learning course. PA was assessed using Axivity AX3 accelerometers, and included light, moderate, vigorous, and total PA minutes/week. Psychological measures included the Basic Psychological Needs Satisfaction and Frustration. K-means cluster analysis identified PA profiles based on light, moderate, and vigorous PA levels (minutes/week). Analysis of variance (ANOVA) and Linear Mixed Models assessed profile differences based on (a) needs satisfaction, (b) needs frustration, (c) autonomy, (d) competence, (e) relatedness. Three PA profiles emerged: a low activity (n = 21), medium activity (n = 22), and high activity cluster (n = 5). These clusters differed significantly in PA levels (p < 0.001). Need satisfaction and frustration did not significantly differ across PA profiles; however, relatedness frustration differed significantly across timepoints (p = 0.036) and needs satisfaction showed descriptive trends across PA profiles. These findings demonstrate heterogeneity in PA engagement among rural youth and provide preliminary descriptive evidence of psychological patterns across these emerging PA profiles. Such differences may generate hypotheses for future research examining whether PA and psychological characteristics can meaningfully inform intervention tailoring. Full article

Waste polyethylene terephthalate (PET) from single-use bottles is generated in rapidly increasing quantities, yet only about 15–35% of PET bottles are recycled. A systematic search of four databases (Scopus, Web of Science Core Collection, Google Scholar and PubMed Central) returned 798 records; after duplicate removal and two-stage screening, 69 studies met the eligibility criteria, of which 28 reported the quantitative performance data that underpin the ranges extracted here. Three recycling routes were compared, namely mechanical recycling, chemical recycling (glycolysis, methanolysis, hydrolysis, pyrolysis and gasification) and enzymatic hydrolysis. PET has been added to concrete, asphalt, bricks, insulation and panels and tested for mechanical strength, physical behaviour and durability under laboratory conditions, and the associated microplastic release, leaching of antimony and phthalate plasticisers, and fire behaviour were also assessed. Costs and market barriers were examined. The evidence indicates that PET is suitable for non-structural and semi-structural applications, and that the reported dosage windows are application-specific rather than reducible to a single range: roughly 5–15% by volume as an aggregate replacement in concrete, 2–10% in asphalt on bases that differ between studies, 25–40% by mass in PET–sand bricks and 0.5–2% fibre volume fraction in fibre-reinforced mortar. Each window is an envelope across studies that differ in PET form, dosage basis, mix design and test standard, and none is a specification. Long-term field testing, standardised leaching and microplastic-release methods, and full life-cycle assessments remain the principal research and application gaps. By linking technical performance to environmental safety, evidence quality and market readiness, this review supports evidence-based decisions for sustainable, circular construction. Full article

Background: Physical activity, screen time, and cardiorespiratory fitness have been associated with cognitive functioning in children; however, their mutually adjusted associations with specific dimensions of selective attention remain insufficiently understood. This study examined the associations of habitual physical activity, screen time, and cardiorespiratory fitness with selective attention in primary school children. Methods: This cross-sectional study included 386 children aged 9–12 years (54.4% girls). Habitual physical activity was assessed using the Physical Activity Questionnaire for Children (PAQ-C), screen time using the Youth Leisure-Time Sedentary Behavior Questionnaire (YLSBQ), cardiorespiratory fitness using the 20 m shuttle run test, and selective attention using the d2-R Test of Attention. Selective attention was characterized by processing speed (TR), percentage of errors (E%), and concentration performance (CON). Associations were examined using correlation and multiple linear regression analyses adjusted for age and sex, followed by hierarchical regression models examining the mutually adjusted associations of physical activity, screen time, and cardiorespiratory fitness with selective-attention outcomes. Results: Higher physical activity was significantly associated with a greater number of total items processed (TR; B = 69.87, β = 0.660, p < 0.001), a lower percentage of errors (E%; B = −1.75, β = −0.356, p < 0.001), and better concentration performance (CON; B = 26.44, β = 0.659, p < 0.001). Greater screen time was primarily associated with a higher error percentage (β = 0.597, p < 0.001), while associations with processing speed and concentration performance were weaker. Higher cardiorespiratory fitness was associated with greater processing speed (β = 0.468), fewer errors (β = −0.455), and better concentration performance (β = 0.667; all p < 0.001). In the final hierarchical models, after mutual adjustment for physical activity, screen time, cardiorespiratory fitness, age, and sex, physical activity was associated with processing speed (β = 0.600, p < 0.001), whereas screen time and cardiorespiratory fitness were not associated with this outcome. For attentional errors, higher screen time (β = 0.523, p < 0.001), lower physical activity (β = −0.117, p = 0.014), and lower cardiorespiratory fitness (β = −0.270, p < 0.001) were associated with a higher error percentage. For concentration performance, both physical activity (β = 0.395, p < 0.001) and cardiorespiratory fitness (β = 0.412, p < 0.001) were positively associated, whereas screen time was not associated with this outcome. Conclusions: Physical activity, screen time, and cardiorespiratory fitness showed distinct associations with specific components of selective attention. Higher physical activity was particularly associated with faster processing speed, higher screen time with greater attentional errors, and both physical activity and cardiorespiratory fitness with better concentration. Given the cross-sectional design, these findings should be interpreted as associations rather than causal relationships. Full article

Art therapy is a nonverbal form of therapy that can provide individuals with a safe and supportive environment for expression and processing, particularly of trauma-related emotions and memories. For individuals who have experienced trauma, this nonverbal, creative, and tactile modality may serve as a beneficial complement, integrative aspect, or alternative to current gold-standard forms of care, including exposure-based cognitive behavioral therapy, cognitive processing therapy, and pharmacotherapy. In this narrative review, findings across the hierarchy of evidence, from theory and case studies to controlled trials and meta-analyses, in both adults and youth, are summarized to explore the benefits and limitations of art therapy to address trauma and related psychopathology. Findings are contextualized within the Expressive Therapies Continuum (ETC). The majority of available evidence comes from case and cohort studies conducted with small samples of one to 30 individuals per study. Systematic reviews and meta-analyses were largely limited by inconsistencies in providers, protocols, and assessments, as well as a lack of long-term follow-up data to understand the persistent effects of art therapy. While a singular narrative review cannot fully reflect the diversity and richness of art therapy or types of traumatic stress in different societies and situations, this article aims to guide future research, with specific design recommendations, prioritization of randomized-controlled trials, and a call for manualized treatment protocols. Full article