Category: Statistics

Front Public Health. 2026 Aug 3;14:1921819. doi: 10.3389/fpubh.2026.1921819. eCollection 2026.

ABSTRACT

BACKGROUND: Publicly accessible large language model (LLM) chatbots are increasingly used to seek nutrition advice. Although vegetarian and vegan nutrition advice is often perceived as low risk, it may involve supplementation, vulnerable life stages, chronic disease, and symptoms that require clinical assessment.

OBJECTIVE: To compare the safety, accuracy, empathy, reliability, information quality, and readability of five publicly accessible LLM chatbot products in responding to public-facing vegetarian and vegan nutrition advice questions.

METHODS: In this cross-sectional comparative study, 58 predefined public-facing vegetarian and vegan nutrition advice questions were submitted once in English to ChatGPT, Gemini, Microsoft Copilot, DeepSeek, and Doubao through their official web interfaces. The final dataset included 290 chatbot responses. Five blinded raters with clinical nutrition training evaluated safety, accuracy, and empathy using predefined reference-answer anchors, and assessed reliability and information quality using four established instruments: the DISCERN instrument, Ensuring Quality Information for Patients (EQIP), Journal of the American Medical Association (JAMA) benchmark criteria, and Global Quality Score (GQS). Readability was assessed using six formula-based indices: the Automated Readability Index (ARI), Coleman-Liau Index (CL), Flesch-Kincaid Grade Level (FKGL), Gunning Fog Index (GFI), Simple Measure of Gobbledygook (SMOG), and Flesch Reading Ease Score (FRES). Model comparisons were paired by question.

RESULTS: Inter-rater agreement was high for all human-rated outcomes. Potentially harmful responses occurred in all models, although adjusted pairwise safety comparisons were not statistically significant. Recurring harm patterns involved vitamin B12 source reliability, uncontrolled iodine or selenium intake, vulnerable life stages, chronic disease, symptom triage, and poorly traceable or overconfident statements. Accuracy, empathy, reliability, information quality, and readability differed significantly across models. ChatGPT, Copilot, and DeepSeek showed higher accuracy; ChatGPT showed higher empathy; Copilot performed best on DISCERN and EQIP; and Gemini produced the most readable responses.

CONCLUSION: Publicly accessible LLM chatbots can provide useful general information on vegetarian and vegan nutrition, but their performance is uneven and safety limitations remain. Chatbot-generated advice should be interpreted cautiously, especially for supplementation, vulnerable groups, chronic disease, and symptoms requiring clinical assessment. Future systems should improve safety guidance, referral cues, source traceability, and plain-language communication.

PMID:42609511 | PMC:PMC13478225 | DOI:10.3389/fpubh.2026.1921819

Health Sci Rep. 2026 Aug 17;9(8):e73059. doi: 10.1002/hsr2.73059. eCollection 2026 Aug.

ABSTRACT

BACKGROUND AND AIMS: Hepatitis B virus (HBV) poses a major occupational risk to healthcare workers (HCWs), particularly in moderate-to-high‑prevalence settings such as Zambia. Despite the availability of a safe and effective vaccine, coverage among HCWs remains suboptimal. Among HCWs, volunteer HCWs face unique challenges, including financial barriers, that increase their risk. However, they are often overlooked in research. The present study aimed to determine HBV vaccination uptake and its predictors among volunteer HCWs in Zambia.

METHODS: This national cross-sectional study utilized a self-administered semi-structured online questionnaire to collect data from volunteer HCWs from October 3 to November 26 2024. Using R version 4.6.0 and Stata version 17, descriptive and inferential statistical analyses were performed. A two-sided p value < 0.05 was considered statistically significant.

RESULTS: Among the 173 participants, 51 (29.5%) reported being vaccinated. Of the 51, 23 (45.1%) had received one dose, 4 (7.8%) two doses, and 24 (47.1%) at least three doses (fully vaccinated). In the multivariable Firth penalized logistic regression model, participants who had access to HBV vaccination programs during training were significantly more likely to be vaccinated than those without such programs (p < 0.001). Availability of HBV testing services at the health facility was also independently associated with vaccination uptake (p = 0.006). Increasing age was associated with slightly higher odds of vaccination (p = 0.025). Gender and place of education were not independently associated with vaccination uptake after adjustment.

CONCLUSION: HBV vaccination coverage among volunteer HCWs in Zambia was low. Vaccination programs during training, age and the availability of HBV testing services were important factors associated with vaccine uptake. Strengthening institutional HBV prevention programs may improve vaccination coverage and reduce occupational risk among HCWs.

PMID:42609506 | PMC:PMC13478847 | DOI:10.1002/hsr2.73059

Front Public Health. 2026 Aug 3;14:1888753. doi: 10.3389/fpubh.2026.1888753. eCollection 2026.

ABSTRACT

BACKGROUND: Dengue fever poses a pervasive, yet escalating public health burden in Mexico and abroad.

METHODS: We conducted a 41-year spatiotemporal analysis of dengue fever across Mexico (1985-2025), integrating monthly case surveillance with climate, land cover, vegetation, and novel disaster severity covariates derived from the Emergency Events Database. Four supervised regression models were trained on 1990-2021 data, with models evaluated on a 2022-2023 temporal holdout and against observed 2024-2025 surveillance totals. Five supplementary hazard analyses examined temporal correlation, disaster type breakdown, spatial co-occurrence, pre/post event trajectories, and sensitivity to scoring weight assumptions.

RESULTS: Mann-Kendall trend analysis identified statistically significant increasing dengue incidence in 15 of 32 states (9 inland), evidencing geographic expansion over four decades. Z-score analysis confirmed 2024 as a profound anomaly across both endemic and emerging states. Hazard features were significantly associated with national monthly dengue counts at lags 0-2 months across the full 1985-2025 series. A + 613% case increase following the June 2024 tropical storm. Sensitivity analyses confirmed the project’s developed ‘Severity Score’ performed comparably to four theoretically motivated differential weighting schemes.

CONCLUSION: This study provides the first structured integration of disaster severity covariates in a dengue forecasting framework for Mexico. Geographic expansion into inland states, the 41-year trend analysis, and the hazard adjustment results collectively support a differentiated public health response that targets both endemic coastal states and newly affected inland regions. The analytical framework is directly transferable to emerging dengue risk contexts in the United States and Central America, geographic neighbors also experiencing increased dengue virus transmission.

PMID:42609501 | PMC:PMC13478283 | DOI:10.3389/fpubh.2026.1888753

Front Psychiatry. 2026 Aug 3;17:1921655. doi: 10.3389/fpsyt.2026.1921655. eCollection 2026.

ABSTRACT

Seasonal affective disorder (SAD) and bipolar disorder (BD) with a seasonal pattern are conventionally framed as disorders of photoperiod and circadian timing, yet affected individuals also show a striking, reproducible metabolic rhythm-carbohydrate craving and weight gain in winter, appetite reduction and weight loss in summer-that has rarely been integrated into mechanistic models of seasonal mood cycling. Building on an evolutionary “metabolic plasticity” view, in which seasonal shifts in energy storage are conserved adaptations that can become maladaptive in predisposed individuals, we propose the Seasonal Metabolic Oscillation (SMO) hypothesis: that the seasonal expansion and contraction of adipose tissue is not merely a passive symptom but a candidate mediator and amplifier of seasonal mood cycling. We advance two claims of deliberately unequal evidentiary strength. The better-supported core claim is that winter adiposity amplifies and helps maintain the depressive phase, by promoting low-grade neuroinflammation and indoleamine 2,3-dioxygenase (IDO1) activation, which diverts tryptophan into the kynurenine pathway, and by adding leptin resistance and stress-axis dysregulation that together bias the brain toward depression. The more tentative, exploratory claim is that the spontaneous loss of adiposity in summer relieves this inflammatory burden and, through photoperiod-driven changes in dopaminergic and circadian signaling, may lower the threshold for mood elevation in predisposed individuals. Pleiotropic circadian and metabolic variants, including ZBTB20 and NPAS2, are proposed to confer joint vulnerability to SAD, obesity, and bipolar spectrum illness. The model yields a central, falsifiable prediction-that within the same individuals seasonal swings in adiposity statistically precede and account for a defined share of seasonal mood change-and is directly testable through weight-stabilization experimental-medicine trials, within-subject longitudinal biomarker tracking, and Mendelian randomization. We stress that the model’s two central assumptions-that seasonal adiposity change temporally precedes mood change, and that a swing of the modest magnitude typical of SAD is quantitatively sufficient to move central neurochemistry-remain experimentally undemonstrated, and that photoperiod is a plausible common cause of both adiposity and mood that only designs decoupling the two can exclude. If supported, SMO would reframe seasonal mood disorders as recurrent metabolic-neuroimmune-mood conditions and motivate metabolically informed screening, pharmacotherapy, and chronotherapy.

PMID:42609474 | PMC:PMC13478500 | DOI:10.3389/fpsyt.2026.1921655

Front Nutr. 2026 Aug 3;13:1853929. doi: 10.3389/fnut.2026.1853929. eCollection 2026.

ABSTRACT

INTRODUCTION: Olive, walnut, flaxseed, and camellia oils are premium edible oils rich in unsaturated fatty acids, yet they exhibit distinct fatty acid profiles: olive and camellia oils are high in monounsaturated fatty acids, while walnut and flaxseed oils are abundant in polyunsaturated fatty acids. Despite their market value and nutritional importance, a systematic comparative metabolomic analysis covering both volatile and non‑volatile compounds under unified conditions has been lacking.

METHODS: We performed a comprehensive metabolomic comparison of the four oils using headspace solid‑phase microextraction/gas chromatography‑mass spectrometry (HS‑SPME/GC‑MS) for volatile compounds and ultra‑high‑performance liquid chromatography‑high‑resolution mass spectrometry (UHPLC‑HRMS) for non‑volatile metabolites. Multivariate statistical methods, including principal component analysis (PCA), partial least‑squares discriminant analysis (PLS‑DA), and relative odor activity value (ROAV) calculation, were applied to identify differential metabolites and characteristic biomarkers.

RESULTS: A total of 100 volatile and 1,186 non‑volatile metabolites were identified, covering alcohols, aldehydes, fatty acids, terpenes, phenolics, and others. PCA and heatmap analyses showed clear separation among the four oils. Common flavor markers included hexanal, ethanol, and ethyl hexanoate, while specific biomarkers such as hydroxytyrosol (olive oil), juglone (walnut oil), lignans (flaxseed oil), and camelliasaponin (camellia oil) were distinguished. ROAV analysis highlighted key flavor‑active volatiles, and differential metabolites were significantly correlated with flavor attributes, oxidative stability, and nutritional characteristics.

DISCUSSION: Our integrated volatile‑non‑volatile metabolomic approach provides a systematic foundation for comparing the compositional, flavor, and quality differences among high‑unsaturated fatty acid vegetable oils. The identified biomarkers and their correlations offer valuable tools for oil authentication, quality control, and functional product development, demonstrating the superiority of combined metabolomic profiling over single‑platform analyses.

PMID:42609451 | PMC:PMC13478218 | DOI:10.3389/fnut.2026.1853929

Front Hum Neurosci. 2026 Aug 3;20:1902938. doi: 10.3389/fnhum.2026.1902938. eCollection 2026.

ABSTRACT

INTRODUCTION: Transcranial direct current stimulation (tDCS) has been proposed as a potential tool for enhancing the benefits of cognitive training, but its added value for working memory in healthy adults remains unclear. This systematic review and robust variance estimation meta-analysis examined whether active tDCS combined with cognitive training improves post-training working memory performance compared with sham tDCS combined with the same training, and whether the effect varies by outcome type, assessment time point, and training characteristics.

METHODS: PubMed, Scopus, and Web of Science were searched from database inception to January 2026. Eligible studies were randomized controlled trials involving healthy adults, comparing active tDCS plus structured cognitive training with sham tDCS plus otherwise identical training, and reporting at least one post-training working memory outcome. Multiple correlated effect sizes within studies were synthesized using robust variance estimation. Outcomes were classified as trained-task outcomes or untrained working-memory outcomes, and both immediate post-test and follow-up assessments were included.

RESULTS: A total of 23 studies contributing 135 effect sizes were included. Active tDCS combined with cognitive training produced a small but statistically significant improvement in post-training working memory performance, Hedges’ g = 0.191, 95% CI [0.062, 0.320], p = 0.006. Effects were significant for trained-task outcomes, whereas effects on untrained working-memory outcomes were smaller and not statistically significant; however, the direct difference between the two outcome categories was not significant. Immediate post-test effects were significant, whereas follow-up effects remained positive and similar in magnitude but lay at the conventional alpha threshold, with no significant difference between time points. Stimulation timing, age group, and training type did not significantly moderate the effect. Sensitivity analyses confirmed the stability of the overall estimate, and no clear evidence of small-study effects was detected.

DISCUSSION: These findings suggest that tDCS may provide a small adjunctive benefit when combined with cognitive training in healthy adults, with the most consistent benefits observed for trained-task performance and more limited evidence for transfer to untrained working-memory outcomes.

PMID:42609444 | PMC:PMC13478250 | DOI:10.3389/fnhum.2026.1902938

Front Public Health. 2026 Aug 3;14:1905069. doi: 10.3389/fpubh.2026.1905069. eCollection 2026.

ABSTRACT

BACKGROUND: Children’s sedentary, lack of activities and low attention in class are common problems in global public health and education. Long-term sedentary will reduce children’s moderate-to-vigorous physical activity (MVPA), damage attention and executive function, and be detrimental to physical and mental health and academic performance. This paper explores the intervention function of structured active break.

METHODS: In this study, 1,248 students from grades 1-6 were enrolled in a stratified cluster randomized controlled trial, with individual classes defined as randomization and clustering correction units and grouped according to grade, gender and BMI. The intervention group had a 5-min structured in-class active break, while the control group maintained routine work and rest. The intervention period was 12 weeks. Activity data were collected by ActiGraph triaxial accelerometer, and concentration was evaluated by momentary time sampling and cancellation test. Generalized Estimating Equations (GEE) was used to correct the clustering effect, and 95%CI, Cohen’s d and partial η² were reported. The test level was α = 0.05, and Bonferroni multiple comparison correction was used for subgroup analysis.

RESULTS: After the intervention, the MVPA and light physical activity (LPA) in the intervention group increased by 18.6 min and 27.4 min, respectively, and the sedentary behavior duration decreased by 36.8 min, and the differences in various indexes and concentration related indexes were extremely significant compared with those in the control group (P < 0.001). Stratified analysis showed that children with lower grades, overweight and weak baseline concentration benefited more from intervention, and there was a significant three-way interaction effect (corrected P < 0.01), but there was no statistical difference between gender subgroups.

CONCLUSION: Short-term structured active break in class can improve children’s activity, reduce sedentary, and improve their concentration, which has a significant effect on junior, obese and attention-deficit students. This study is limited by a single-site sample, short-term follow-up, and a lack of physiological biomarker measurements, which restricts the generalizability of its conclusions. The related neural mechanism is still theoretical speculation and needs long-term multi-center research to prove it. This low-cost intervention can improve school-based health outcomes and classroom learning efficiency, and provide empirical evidence.

PMID:42609440 | PMC:PMC13478256 | DOI:10.3389/fpubh.2026.1905069

Front Behav Neurosci. 2026 Aug 3;20:1797790. doi: 10.3389/fnbeh.2026.1797790. eCollection 2026.

ABSTRACT

Romantic love lacks a mechanistic, testable evolutionary account. Prior work notes parallels with mother-infant bonding but leaves the genetic architecture and falsifiable predictions unspecified. We argue that romantic love evolved not through the evolution of new “love genes,” but by altering the regulation of existing genes: changing when, where, and under what physiological conditions these genes are active. This regulatory co-option framework generates several falsifiable predictions: (1) a shared genetic basis between maternal bonding and romantic love, (2) the involvement of non-coding, regulatory DNA regions in the brain, (3) a largely shared genetic architecture between the sexes, with differences in gene expression, and (4) genetic signals localized to specific brain circuits. We outline specific genomic and statistical methods to test these predictions, establishing clear criteria that would support or refute our hypothesis. This work shifts the study of romantic love’s evolution from analogy to a program of empirical inquiry and hopes to shed light on how social monogamy entered the Homo sapiens lineage. Key challenges include the lack of high quality meta-analytic fMRI evidence of romantic love and the scarcity of detailed data from relevant human brain circuits.

PMID:42609431 | PMC:PMC13478075 | DOI:10.3389/fnbeh.2026.1797790

Front Public Health. 2026 Aug 3;14:1896815. doi: 10.3389/fpubh.2026.1896815. eCollection 2026.

ABSTRACT

OBJECTIVE: To systematically evaluate the application effect of flipped classroom (FC) teaching mode in preventive medicine courses in Chinese medical colleges and universities.

METHODS: A systematic search was conducted in PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), etc. to search for reports on the FC teaching model in preventive medicine courses. A quantitative system evaluation was conducted to assess the teaching effectiveness of FC with multiple indicators such as exam score, learning interest, and self-learning and thinking abilities.

RESULTS: A total of 28 articles were included, including 2,135 students in the flipped classroom group and 2,259 students in the LBL group. It showed that compared with the lecture-based learning (LBL) group, the FC can significantly improve students’ exam scores for both theoretical and practical components, their quantitatively synthesized SMDs were 0.99 (95% CI: 0.65-1.33) and 0.50 (95% CI: 0.30-0.70), respectively. Meanwhile, learning interest (RR = 1.42, 95%CI:1.33-1.53), independent learning and thinking ability (RR = 1.51, 95%CI: 1.31-1.73), cooperation and communication skills (RR = 1.60, 95%CI: 1.28-2.01), problem analysis and solving ability (RR = 1.47, 95%CI: 1.13-1.91), and teacher-student interaction (RR = 1.35, 95%CI: 1.10-1.66), the differences are statistically significant (p < 0.05).

CONCLUSION: The FC teaching model has shown significant advantages in the teaching of preventive medicine courses in Chinese higher medical colleges. In view of this, schools can reasonably apply it in relevant course teaching according to resources such as faculty and facilities.

PMID:42609425 | PMC:PMC13478085 | DOI:10.3389/fpubh.2026.1896815

Front Psychol. 2026 Aug 3;17:1878259. doi: 10.3389/fpsyg.2026.1878259. eCollection 2026.

ABSTRACT

INRODUCTION: Loneliness is a common and universal human experience associated with adverse psychological outcomes. Therefore, identifying psychological factors that reduce loneliness and strengthen individuals’ coping capacity may contribute to the development of more effective psychological interventions.

METHODS: The primary aim of this study was to examine the associations among self-efficacy, psychological flexibility, and loneliness, with particular emphasis on the indirect association between self-efficacy and perceived loneliness through psychological flexibility in a cross-sectional model. Data were collected using a Personal Information Form, the SELSA-S Social and Emotional Loneliness Scale, the Psychological Flexibility Scale, and the Self-Efficacy Scale. Pearson product-moment correlation analysis was conducted to examine the associations among the variables, and regression analysis was performed to examine the associations between self-efficacy, perceived loneliness, and psychological flexibility. The bootstrapping mediation analysis using the PROCESS macro (Model 4, 5000 bootstrap resamples) was conducted to examine the indirect association between self-efficacy and perceived loneliness through psychological flexibility. The sample consisted of 412 young adults recruited through convenience sampling.

RESULTS: The findings indicated that self-efficacy was positively associated with psychological flexibility and negatively associated with perceived loneliness, whereas psychological flexibility was negatively associated with perceived loneliness. Furthermore, a statistically significant indirect association between self-efficacy and perceived loneliness through psychological flexibility was observed in the cross-sectional model, whereas the direct association was not statistically significant.

DISCUSSION: These findings suggest that psychological flexibility may be relevant to the association between self-efficacy and perceived loneliness. However, given the cross-sectional design and convenience sampling, the findings should not be interpreted as evidence of causal mediation.

PMID:42609416 | PMC:PMC13478243 | DOI:10.3389/fpsyg.2026.1878259