Tag: pubmed

Am J Hum Biol. 2026 Jul;38(7):e70306. doi: 10.1002/ajhb.70306.

ABSTRACT

OBJECTIVES: Geographic variation in child body size in Japan has previously been associated with effective day length, a light-related measure. We tested whether this prefecture-level geographic structure remained stable across the COVID-19-related disruption.

METHODS: We conducted a prefecture-level ecological analysis using repeated cross-sectional summaries from Japan’s School Health Statistics. For each sex and single-year age from 5 to 17 years, we compared a pre-pandemic baseline (2017-2019 mean) with a post-disruption period (2024-2025 mean). Effective day length above 5000 lx (ED5000) was treated as a prefecture-fixed exposure. Mean height was modeled as a function of mean weight and ED5000, and slope stability was tested using pooled models with an ED5000-by-period interaction term.

RESULTS: Across ages 5-17 years in both sexes, mean height was generally higher in the post-period than in the pre-period, and mean weight also showed an upward shift across most ages, with the largest increases around peri-pubertal ages. ED5000 remained negatively associated with height conditional on weight in both periods, and there was no evidence that the ED5000-associated slope changed between periods at any age in either sex. In contrast, post-period differences in height appeared mainly as age-dependent upward shifts concentrated around peri-pubertal ages, peaking at ages 10-11 years in girls and 12-13 years in boys.

CONCLUSIONS: These findings suggest that COVID-era disruptions were followed by age-specific increases in body size around puberty, consistent with changes in maturation tempo. In contrast, the ED5000-height association remained stable. Thus, period-related growth shifts occurred within a persistent geographic structure.

PMID:42400118 | DOI:10.1002/ajhb.70306

BMC Psychol. 2026 Jul 3. doi: 10.1186/s40359-026-05097-x. Online ahead of print.

ABSTRACT

BACKGROUND: The study examines the relationship between human capital, including education and work experience, and the intention of Vietnamese workers to work extra hours. Working extra hours is common but poses risks to health and productivity, especially in developing economies with large informal sectors.

METHODS: We used data from the Vietnam Labor Force Survey with 200,242 observations. Because the dependent variable is a rare event, we applied Firth bias‑corrected logistic regression combined with the Karlson-Holm-Breen decomposition method to test the mediating role of income.

RESULTS: Employees with higher education or longer work experience have significantly lower intention to work extra hours. Income statistically accounts for a small portion of this association for education, but a negligible portion for experience. People with short‑term or no contracts, those working in individual businesses, or heads of households tend to be more willing to work extra hours. In contrast, lower intention is associated with working in the public sector, medium- and large-sized enterprises, or having an indefinite-term contract.

CONCLUSIONS: High human capital is associated with reduced need for working extra hours intentionally, mainly through non-financial channels rather than through income. Investing in education, vocational training, expanding formal contracts, and improving incomes may be associated with reduced pressure to work involuntary extra hours.

PMID:42400101 | DOI:10.1186/s40359-026-05097-x

BMC Psychol. 2026 Jul 4;14(1):975. doi: 10.1186/s40359-026-05101-4.

ABSTRACT

The Locus of Control short scale (IE-4) is a screening instrument for locus of control (LOC). Assessment of LOC is highly relevant within psychological research and social sciences. The aim of the current study was to evaluate the screening tool in a large representative sample, with special focus on its dimensionality and the presence of acquiescence bias. The current sample (N = 2522; Age: M = 48.50 years (SD = 17.75); 50.1% female) was representative for the German adult population with respect to gender, age, and education. After conducting a CFA including an uncorrelated method factor, model fit indices generally indicated a good fit. Additionally, we found evidence of good reliability. Results from this study suggest that the IE-4 is best considered as a unifactorial measure when accounting for acquiescence bias.

PMID:42400100 | DOI:10.1186/s40359-026-05101-4

BMC Psychol. 2026 Jul 3. doi: 10.1186/s40359-026-04885-9. Online ahead of print.

ABSTRACT

BACKGROUND: Bullying and cyberbullying are well recognized mental health risk factors and are of major public health concern during adolescence, yet inconsistencies in assessment methods and longitudinal design hinder accurate prevalence estimation and understanding of developmental trajectories. This longitudinal study aimed to: (a) compare prevalence estimates of bullying and cyberbullying using single-item versus multi-item assessments; (b) assess developmental changes in victimization and perpetration from 6th to 8th grade (ages 10-13).

METHODS: A cohort of 788 Italian middle school students (50.5% male) completed assessments in sixth (2015-2016) and eighth grade (2017-2018). Bullying and cyberbullying were measured with single-item and multi-item self-report instruments. Analyses included descriptive statistics, Pearson’s correlation alongside point-biserial correlations, McNemar’s tests, paired t-tests, generalized estimating equation models, mixed repeated-measures ANOVAs, Stuart-Maxwell tests, and intraclass correlation coefficients.

RESULTS: Single- and multi-item measures showed moderate convergence (r = .36-0.51). Single-item measures primarily capture global self-identification with victim or perpetrator roles, whereas multi-item measures provide greater specificity regarding the frequency, context, and modality of bullying. Measurement method influenced developmental trends: bullying victimization decreased as children got older using single-item tools (χ² = 24.59, p < .001) but remained stable with multi-item, while perpetration increased only via multi-item (d = -0.28). Cyberbullying findings were more tentative: single-item victimization decreased, multi-item victimization remained stable, and multi-item perpetration showed only a small increase. Supplementary analyses showed no significant Time × Sex interactions, and school-level clustering was negligible.

CONCLUSIONS: Findings highlight that bullying assessment methodological choices strongly influence prevalence and developmental estimates. Multi-method longitudinal designs are crucial for valid assessment and effective prevention.

PMID:42400099 | DOI:10.1186/s40359-026-04885-9

BMC Sports Sci Med Rehabil. 2026 Jul 3. doi: 10.1186/s13102-026-01859-7. Online ahead of print.

ABSTRACT

OBJECTIVE: The aim of this study was to determine the levels of self-talk among male football players aged 18 and over who are actively playing football, and to examine whether these levels differed according to variables such as age, education, team type, position, duration of football playing, weekly sports day, willingness to work with a sports psychologist, perception of the benefit of a sports psychologist, and preference for sharing problems.

METHOD: The study included 167 male football players (age range = 18-33, mean age = 23.8, SD = 4.2) who were actively playing football during the 2022-2023 season. Data were collected using the Self-Talk Scale (SPS). Mann-Whitney U tests were used for two-group comparisons, Kruskal-Wallis H tests for three-or-more-group comparisons, and Spearman correlation for continuous variables, as normality was violated.

FINDINGS: The Cronbach’s Alpha reliability coefficient of the scale was found to be 0.96. The mean self-talk score of the participants was 5.12/7, indicating a moderate-to-high level of self-talk. The analysis revealed that although the Kruskal-Wallis test indicated an overall age difference (p = .043, ε² = .059), post-hoc pairwise comparisons with Bonferroni correction were not significant (all p > .005). For team type, a significant overall difference was observed (p = .031, ε² = .042), but post-hoc comparisons did not remain significant after Bonferroni adjustment (p = .024, adjusted α = .017) ; this finding should be considered exploratory due to the small professional group size (n=8). For problem sharing preference, the overall Kruskal-Wallis test was significant (p = .029, ε² = .054), but post-hoc comparisons with Bonferroni correction did not reach statistical significance (all p > .003). No significant differences were found in the variables of position, education level, duration of playing football, and weekly sports days (p > .05). In the correlation analysis, a negative correlation was found between years of playing football and self-talk (ρ = -.19, p = .014), and a positive correlation was found between weekly sports days and self-talk (ρ = .22, p = .005).

CONCLUSION: The level of self-talk among male individuals who actively play football is moderate-to-high. Age, team level, awareness of sports psychology, and family support were determining factors in the level of self-talk; while position, education, and duration of sports experience were not determining factors. The findings provide evidence-based recommendations for coaches and sports psychologists to develop psychological skills training programs, particularly for young and amateur players.

PMID:42400075 | DOI:10.1186/s13102-026-01859-7

BMC Sports Sci Med Rehabil. 2026 Jul 3. doi: 10.1186/s13102-026-01849-9. Online ahead of print.

ABSTRACT

BACKGROUND: Postural control relies on the integration of somatosensory, visual, and vestibular information, with age-related declines in these systems contributing, as well as motor performance, to diminished balance performance. Regular sport participation may mitigate these effects, yet limited data exist on postural stability in Masters Olympic-style weightlifters-a population performing highly demanding, balance-dependent movements. This study examined age- and sex-related differences in quiet-stance postural stability in competitive Masters weightlifters and explored whether postural stability contributes to weightlifting performance beyond countermovement jump (CMJ) peak power.

METHODS: During the 2022 World Masters Weightlifting Championship, 104 competitors (67 females, 37 males; ages 35-75 years) from 11 countries completed balance testing under four conditions: firm and foam surfaces, each with eyes open and eyes closed. Medial-lateral sway velocity index (SVI) was computed from force-plate data and averaged across two 30-s trials per condition. Participants also completed CMJ testing to determine peak concentric power normalized to body mass. Postural stability was analyzed using linear quantile mixed‑effects models. Weightlifting performance was defined by standardizing the total weight lifted (z‑score), calculated by adjusting the total weight lifted across body mass and sex. Median regression models examined associations of SVI and CMJ peak power with performance.

RESULTS: Postural stability decreased on the foam surface compared with the fixed surface (median difference 0.47, p < 0.001), and closed eyes further exacerbated sway (interaction 0.23, p < 0.001). SVI increased modestly with age (per 5 years: 0.03, p < 0.001), while no sex differences were observed. Countermovement jump peak power was strongly associated with better weightlifting performance (coefficient 0.24, p < 0.001). Better postural stability (lower SVI) may enhance the effect of peak power on performance (coefficient – 0.07, p = 0.055), although it did not reach statistical significance.

CONCLUSIONS: Masters weightlifters demonstrated modest age-related decline in postural stability on stable surfaces and no sex differences across conditions. Under challenging sensory conditions, postural stability decreased with older age, yet it remained well maintained on stable surfaces. While peak power was a strong determinant of weightlifting performance, postural stability may provide an additional, though modest contribution. Further longitudinal studies are warranted to evaluate balance and performance with advancing age.

PMID:42400071 | DOI:10.1186/s13102-026-01849-9

BMC Health Serv Res. 2026 Jul 3. doi: 10.1186/s12913-026-14901-8. Online ahead of print.

ABSTRACT

BACKGROUND: This cross-sectional study investigates healthcare practitioners’ perceptions of the implementation of artificial intelligence (AI) to enhance patient safety culture in Riyadh, Saudi Arabia, conducted from March to June 2025. The focus is on understanding how AI is perceived in the context of improving patient safety culture and aligning with Saudi Vision 2030 goals.

METHODS: The study employed a cross-sectional design and administered self-administered online surveys via convenience sampling among healthcare practitioners across multiple healthcare settings in Riyadh. The study targeted a population including doctors, nurses, and allied health professionals. A structured questionnaire was developed to assess perceptions of AI, including key variables such as perceived AI benefits, concerns about data privacy, and the necessity of training. Descriptive statistics were computed to characterize the sample, including age, gender, and profession.

RESULTS: Findings revealed that most participants perceived AI as supportive of patient safety through improved diagnostic accuracy, reduced medical errors, and streamlined workflows, which participants believed may contribute to a stronger patient safety culture. Descriptive analyses suggested variation in perceptions across professional groups.

DISCUSSION: The study found that healthcare practitioners in Riyadh generally perceived AI as a potentially valuable tool for supporting patient safety culture, particularly through improving diagnostic accuracy and reducing errors; however, concerns about data privacy and insufficient training remain significant barriers that must be addressed to ensure effective and safe AI integration.

CONCLUSIONS: This study highlighted healthcare practitioners’ positive perception of AI’s role in enhancing patient safety culture in Riyadh. While AI is seen as beneficial in improving accuracy and reducing errors, challenges such as data privacy concerns and a lack of training were identified as barriers to its implementation.

CLINICAL TRIAL NUMBER: Not applicable.

PMID:42399990 | DOI:10.1186/s12913-026-14901-8

BMC Sports Sci Med Rehabil. 2026 Jul 3. doi: 10.1186/s13102-026-01838-y. Online ahead of print.

ABSTRACT

BACKGROUND: Exercise-induced hypoalgesia (EIH) is vital for rehabilitation, but its efficacy in patients with knee pain remains controversial. Blood flow restriction (BFR) might augment analgesia through metabolic accumulation. This study aimed to investigate the acute analgesic impact of a low-intensity warm-up with or without BFR and to compare EIH responses between healthy individuals and patients with persistent knee pain.

METHODS: Forty-six participants (healthy controls: n = 26; participants with persistent knee pain: n = 20) were enrolled in a single-session, within-subject split-body protocol. BFR at 70% arterial occlusion pressure was applied to one limb during a 5-min low-intensity warm-up. The BFR-treated limb was randomized in healthy controls, whereas in participants with persistent knee pain, BFR was consistently applied to the symptomatic limb, with the contralateral asymptomatic limb serving as the within-subject comparison. Pressure pain thresholds (PPT) were measured at three peri-patellar sites pre- and post-condition using a Latin Square design. Data were analyzed via Linear Mixed Models.

RESULTS: Healthy controls showed a robust increase in PPT after warm-up (+ 5.55 N, 95% CI, 4.20 to 6.90), whereas participants with persistent knee pain showed no clear increase (+ 0.15 N, 95% CI, -1.39 to 1.69). The between-group difference in EIH was significant (+ 5.40 N, 95% CI, 3.36 to 7.45, p < 0.001). The EIH response was markedly attenuated in participants with persistent knee pain, a finding consistent with altered endogenous pain modulation. However, the present data do not directly identify the central or peripheral mechanisms underlying this attenuation. The additional BFR effect was small and not statistically significant (-0.14 N; 95% CI, -2.18 to 1.91; p = 0.894), suggesting the tested BFR protocol did not demonstrate statistically superior additional hypoalgesic effects compared with the non-BFR condition.

CONCLUSION: A brief low-intensity warm-up induced a clear EIH response in healthy controls, whereas participants with persistent knee pain showed a markedly attenuated response. The tested BFR protocol did not demonstrate statistically superior additional hypoalgesic effects compared with the non-BFR condition. These exploratory findings warrant further investigation using adequately powered, prespecified, and mechanistically informed studies.

TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2300069386 (https://www.chictr.org.cn/, registered on 15 March 2023).

PMID:42399981 | DOI:10.1186/s13102-026-01838-y

J Ethnobiol Ethnomed. 2026 Jul 3. doi: 10.1186/s13002-026-00924-2. Online ahead of print.

ABSTRACT

BACKGROUND: Domestication is an evolutionary process guided by humans. It operates continuously in multiple directions, with species undergoing adaption to diverse human-influenced environments and cultural and technological contexts. Mesoamerica is among the world’s main regions of domestication and the Agave genus is widely used and managed in this region, with at least eleven domesticated and semi-domesticated species. One species, Agave americana, comprises two subspecies and four varieties, the diversification of which is hypothetically related to human management. This study explores this hypothesis by analysing morphological variation and its relation to environmental and management settings.

METHODS: Ethnobotanical studies were conducted to document uses, management practices, and targets of human selection, together with patterns of morphological variation across different ecological and cultural contexts. Semi-structured interviews were carried out with agave managers throughout the species’ distribution range in Mexico. Morphometric analyses were performed on populations occurring under contrasting environmental and management conditions. Multivariate and univariate statistical analyses were used to evaluate morphological variation in relation to geographic distribution, environmental conditions, and management regimes.

RESULTS: A. americana is used to extract sap for preparing the fermented beverage called pulque. Its stems have been used as food since prehistoric times, when they were cooked in underground ovens. This cooked matter forms the basis of current fermentation and the production of distilled mescal. The fibre of some varieties has been used to make cords and textiles. Both subspecies are managed, but the subspecies protamericana clearly has wild populations. Morphometric studies confirm the presence of traits indicative of domestication in most varieties of the subspecies americana.

CONCLUSIONS: Phenotypic variation within the Agave americana complex is associated with taxonomic identity, geographic distribution, and management intensity. The observed patterns are consistent with the effects of human selection, particularly in traits related to plant size and the reduction of defensive structures. However, further studies integrating common-garden experiments, population genetics, and phylogeographic analyses are required to clarify the evolutionary history and genetic basis of the observed variation.

PMID:42399974 | DOI:10.1186/s13002-026-00924-2

BMC Med Educ. 2026 Jul 3. doi: 10.1186/s12909-026-09845-w. Online ahead of print.

ABSTRACT

BACKGROUND: Clinical belongingness is one of the most important needs of nursing students for optimal performance in learning environments and, therefore, is of particular importance in clinical education. The present study investigated the relationship between clinical instructors’ leadership styles and clinical belongingness among undergraduate nursing students.

METHODS: This cross-sectional study was conducted between January and February 2025 among undergraduate nursing students from the fourth to eighth semesters at two nursing schools affiliated with Zanjan University of Medical Sciences, Iran. A total of 274 eligible students were invited to participate. After excluding 21 incomplete questionnaires, data from 253 students were analyzed. Data were collected using a demographic questionnaire, the Multifactor Leadership Questionnaire (MLQ-6 S), and the Belongingness Scale-Clinical Placement Experience (BES-CPE). Data were analyzed using descriptive and inferential statistics, including independent t-test, ANOVA, Pearson correlation, and multiple regression analyses, with a significance level of 0.05.

RESULTS: The mean total score of clinical belongingness in students was 100.04 ± 20.47, which is moderate. From their perspective, the highest and lowest mean scores of clinical instructors’ leadership styles were for transactional (3.86/average per item) and transformational (1.91/average per item), respectively. Also, there was a statistically significant relationship between transformational and transactional leadership styles and clinical belongingness, and these two styles were associated with 18% of the variance in students’ clinical belongingness.

CONCLUSION: The results of this study showed a positive relationship between clinical instructors’ leadership styles and clinical belongingness among nursing students. Therefore, it is recommended to provide training opportunities that familiarize clinical instructors with different leadership styles and encourage the use of leadership approaches that are associated with higher levels of clinical belongingness among nursing students.

PMID:42399972 | DOI:10.1186/s12909-026-09845-w