Search Results (202)

This study validated a controlled in vivo test protocol using a patented particulate exposure chamber (Korean Patent No. 10-2020-0068941) to evaluate the anti-particulate adhesion efficacy of a cosmetic sunscreen formulation (SPF 50+, PA++++). The primary aim was methodological—to demonstrate that the chamber system can reliably detect differences in carbon black adhesion under standardised conditions. A split-site paired design was applied to 22 healthy adult females (mean age 60.3 ± 5.2 years; range 46–68 years). Carbon black particles (≤10 μm) were dispersed via a precision dual-stage pneumatic nozzle within a sealed chamber (22 ± 2 °C; 50 ± 5% RH). Between-group comparison was assessed by the Wilcoxon signed-rank test (primary) and the generalised estimating equation (GEE) model (complementary between-group comparison per institutional SOP). The treated site showed a 55.0% reduction in carbon black adhesion (treated: 4243 ± 2225 pixels; control: 9430 ± 4769 pixels, SE = 4.82, 95% CI: −64.4 to −45.6, Wald Z = −11.41, p < 0.001; Cohen’s d = 2.43). The Wilcoxon test confirmed the result independently (Z = −4.11, p < 0.001). All 22 subjects (100%) showed consistent reduction directionality (individual rates: 22.6–74.2%; mean 51.8%; median 52.3%). Bootstrap resampling (n = 10,000), outlier-exclusion, and exact sign test sensitivity analyses all confirmed robustness. These findings represent proof-of-concept methodological validation applied to a single product under accelerated exposure conditions. Full article

This paper examines how international crude-oil price movements are transmitted to natural-rubber prices through the petrochemical–synthetic-rubber chain, with implications for Thailand as the world’s leading natural-rubber exporter and China as the dominant consumer. Using monthly data from April 2003 to March 2026 on the OPEC reference basket, butadiene, styrene–butadiene rubber (SBR), and the Shanghai natural-rubber benchmark, the analysis combines a nonlinear ARDL specification with a Pesaran–Shin–Smith bounds test, a long-run association decomposition into direct and synthetic-rubber-mediated components with bootstrap inference, and a threshold-NARDL extension that conditions the decomposition on the inventory state. Three findings stand out. First, the synthetic-rubber-mediated component accounts for approximately three-quarters of the estimated oil–natural rubber long-run association (73.5 percent, 95 percent bootstrap CI [60.6, 87.2]), with the residual direct component accounting for the remainder. Second, long-run pass-through is directionally consistent with concentration in the synthetic-rubber component, although Wald tests do not reject symmetry at conventional levels for either the synthetic-rubber component (Wald $p=0.135$) or the direct oil component ($p=0.166$). Third, the synthetic-rubber-mediated share is consistently larger in low-inventory regimes by 26 to 66 percentage points across three alternative regime variables, although the magnitude amplification of asymmetric pass-through itself is not robust. Asymmetric local projections and a Diebold–Yilmaz spillover analysis are reported as complementary horizon-indexed and network checks. The results imply that the synthetic–natural rubber spread, conditioned on the inventory state, may be more informative for natural-rubber price-risk monitoring than crude-oil prices alone. These findings have implications for commodity price-risk monitoring, export-income exposure, and stabilisation design in rubber-exporting economies. Because crude-oil shocks are not externally identified, all estimates are interpreted as decompositions of long-run association rather than causal mediation effects. Full article

Essential tremor (ET) is a common movement disorder increasingly recognized as a complex syndrome with neurodegenerative features. While mitochondrial dysfunction and cellular aging are implicated in several neurodegenerative diseases, their role in ET remains unexplored. To investigate mitochondrial DNA copy number (mtDNA-CN) and telomere length (TL) in patients with ET and evaluate their potential as biomarkers of mitochondrial dysfunction and biological aging. In this cross-sectional case–control study, 68 ET patients (median age 66 years; 64.7% male) and 62 healthy controls (median age 70 years; 54.8% male) were enrolled. Relative mtDNA-CN and TL were quantified by quantitative PCR, measuring mitochondrial ND1 gene levels and telomere-to-single-copy gene (T/S) ratio, respectively, both normalized to β-actin. Associations with disease status were assessed using age- and sex-adjusted multivariable linear regression on log₂-transformed data, with statistical significance defined as p < 0.05 after false discovery rate (FDR)-corrected Wald tests. Receiver operating characteristic (ROC) and effect size (Cohen’s d) analyses were performed. ET patients showed significantly reduced mtDNA-CN (β = −2.785, 95% CI −3.700 to −1.869; p_FDR = 2.53 × 10⁻⁹) and TL (β = −2.073, 95% CI −2.758 to −1.388; p_FDR = 3.00 × 10⁻⁹), corresponding to ~6.9-fold and ~4.2-fold reductions, respectively. Age- and sex-stratified analyses confirmed consistent reductions, more pronounced in older individuals. Both biomarkers showed good discriminatory performance (mtDNA-CN: AUC = 0.83, 95% CI: 0.75–0.90; TL: AUC = 0.76, 95% CI: 0.68–0.85) and large effect sizes (Cohen’s d = |1.192| and |1.058|), respectively. Reduced mtDNA-CN and TL support the involvement of mitochondrial impairment and accelerated cellular aging in ET and may represent accessible peripheral biomarkers and provide a basis for future longitudinal and mechanistic investigations. Full article

This study investigates the relationship between renewable energy (RE) expansion and economic diversification in Egypt over 1990–2023 using a nonlinear autoregressive distributed lag (NARDL) framework. Egypt’s fossil fuel share stands at approximately 93% of primary energy supply, yet the country has committed to a 42% renewable electricity target by 2035. Despite quadrupling utility-scale RE capacity from 2.8 GW to 11.2 GW between 2015 and 2023, the Economic Diversification Index (EDI) has remained broadly stagnant. The bounds test confirms long-run cointegration (F = 6.760), exceeding small-sample critical values at the 1% level. Long-run estimates reveal that positive RE shocks are associated with lower diversification (θ⁺ = −0.571, p = 0.035) and negative shocks exhibit a statistically similar adverse effect (θ⁻ = −0.271, p = 0.024). Oil rents exhibit a positive long-run association (β = 0.145, p = 0.003). The error-correction term (−0.569) indicates approximately 57% annual adjustment. The Wald test provides marginal evidence against long-run symmetry (F = 2.999, p = 0.097). To complement the Granger causality analysis and address small-sample concerns, we additionally implement the Toda and Yamamoto augmented VAR procedure, which confirms robust unidirectional temporal precedence from LRE to LEDI (χ² = 23.48, p < 0.001) without reverse feedback (χ² = 2.25, p = 0.133). These patterns are interpreted through the lens of the Green Dependency Paradox—a conceptually distinct framework characterized by three mechanisms absent from classical resource curse theory: technology-mediated capital flight, procurement-induced deindustrialization, and policy-reversible lock-in operating under conditions of high import content, absent local content mandates, and fragmented industrial policy coordination. A tri-phase, evidence-grounded policy framework is proposed. All findings are explicitly conditional on Egypt’s current institutional context. Full article

Oil is a major source of income and emissions in the Saudi economy. Thus, this study examines the symmetrical and asymmetrical impacts of oil rents (ORs) on CO₂ emissions using data from 1970 to 2024. For this purpose, the Nonlinear Autoregressive Distributed Lag (NARDL) model is applied, while the conventional ARDL model is used as a baseline model. In addition, the moderating effect of geopolitical risk (GPR) is also tested in the association between OR and emissions. The Environmental Kuznets Curve is validated in both the long run and the short run. Moreover, OR is found to be a major driver of emissions, and positive shocks amplify emissions more than negative shocks reduce them. GPR has a negative relationship with emissions, and the impact of positive shocks in GPR is found to be greater than the impact of negative shocks in GPR. However, the interaction between OR and GPR shows that simultaneous increases in both factors exacerbate emissions, whereas the effect of negative shocks in this interaction is insignificant. Thus, asymmetry is corroborated in all investigated relationships. Moreover, the Wald tests also confirm significant asymmetric relationships. The findings suggest reducing oil dependence and adopting GPR-sensitive planning to mitigate the environmental impacts of the oil sector in line with Vision 2030 and the Sustainable Development Goals (SDGs). Full article

Online reviews are increasingly pivotal in consumer decision-making, with platforms employing mechanisms such as badges to denote reviewer credibility. Although prior research has examined the influence of expert reviewers, it has typically treated badge holders as a homogeneous group, overlooking how variation in tenure within expert tiers shapes the way readers process review content. This article examines how Yelp Elite badge tenure, operationalized as Red (1–4 years), Gold (5–9 years), and Black (10+ years) tiers and treated as a proxy for accumulated platform-recognized expertise, moderates the effects of peripheral cues (Extremity, Length) and central cues (Readability, Subjectivity, and Plutchik’s eight emotions) on perceived helpfulness within an Elaboration Likelihood Model (ELM) framework. The analysis draws on the full population of 324,426 restaurant reviews authored by Yelp Elite badge holders between 2019 and 2021, using a pooled count-model specification with badge tier as a categorical moderator. The primary specification is estimated using Poisson quasi-maximum likelihood with HC1-robust standard errors, and full negative binomial estimation is reported as a robustness check. Wald tests indicate that badge tenure significantly moderates eight of twelve cue–helpfulness relationships (${\chi }^2\left(24\right)=4938$, $p<0.001$). The effect of readability is monotonically positive and increases sharply with tenure, while the effect of joy varies across tenure groups. These findings suggest that reviewer expertise signals are not monolithic, refining theoretical insights on how tenure-based credibility cues moderate cue processing and offering practical implications for review platform management. The findings also indicate that platforms applying uniform ranking or surfacing rules across all Elite reviewers risk misallocating visibility, and that tenure-conditional weighting of textual cues warrants consideration. Full article

This study examines the long- and short-run determinants of green employment in Saudi Arabia over the period 1990–2024 using an Autoregressive Distributed Lag (ARDL) bounds testing framework within an error-correction model. Six macroeconomic and structural variables are analyzed: renewable energy capacity, GDP growth, domestic credit, urbanization, foreign direct investment, and the Vision 2030 policy regime shift. Supplementary analyses test the Environmental Kuznets Curve (EKC) hypothesis and map causal relationships using pairwise Granger causality tests. The bounds test indicates long-run cointegration among the variables (F = 8.45, exceeding the 5% I(1) critical bound of 3.61). The model explains 89% of the variation in log green employment (R² = 0.89) and passes standard diagnostic tests for serial correlation, heteroskedasticity, normality, and parameter stability. Three correlates of long-run green employment are identified. The post-2016 dummy used to capture the Vision 2030 regime shift is associated with the largest coefficient in the long-run equation (θ = 1.75, p = 0.008), although this estimate should be interpreted with caution because the dummy absorbs all post-2016 changes, including policy effects, the rapid expansion of renewable capacity, broader institutional reforms, and possibly changes in measurement practices. Renewable energy capacity is the primary continuously measurable driver (θ = 0.145, p = 0.018), with Toda–Yamamoto modified Wald tests indicating a bidirectional predictive relationship between investment and employment. Urbanization exerts a significant positive long-run effect (θ = 0.098, p = 0.001). The error correction term (δ = −0.520, p < 0.001) implies equilibrium reversion with a half-life of approximately one year. The EKC hypothesis is not supported in the Saudi context, suggesting that active decarbonization policy—rather than income-driven structural change alone—is needed for environmental improvement. The findings carry implications for Vision 2030 implementation and for other resource-dependent economies undertaking structural green transitions. Full article

Achieving sustainable development requires decoupling economic growth from environmental degradation. In this context, this study examines the effects of tourism arrivals on CO₂ intensity and energy intensity, two key indicators of environmental sustainability aligned with SDGs 7 and 13. Panel autoregressive distributed lag (ARDL) and nonlinear ARDL models are employed using a balanced panel of 54 countries over the period 1996–2023. In addition, Wald tests for long-run asymmetry, dynamic multiplier analysis, and Dumitrescu–Hurlin causality tests are applied. The results confirm the existence of stable long-run relationships between tourism arrivals and both CO₂ intensity and energy intensity. In the symmetric framework, tourism growth is associated with significant long-run reductions in CO₂ and energy intensity, while short-run effects are negative and significant only for CO₂ intensity. In the asymmetric framework, positive tourism shocks generate stronger and more persistent reductions in both intensity measures, whereas negative shocks lead to weaker environmental efficiency gains. Moreover, the Wald test shows the existence of long-run asymmetry between positive and negative tourism shocks. In addition, the dynamic multiplier analysis confirms that environmental intensity adjusts gradually over time following tourism shocks. Finally, Dumitrescu–Hurlin causality tests indicate bidirectional Granger causality relationships between tourism arrivals and environmental intensity indicators. The findings are robust to dynamic endogeneity, the COVID-19 shock, and country heterogeneity. Overall, the findings indicate that tourism arrivals contribute to lowering long-term environmental intensity, consistent with relative decoupling and the goals of sustainable tourism development. Full article

This paper examines how remittances-to-GDP are conditionally associated with GDP growth upswings and downturns in four lower-middle-income countries (LMICs) in mainland Southeast Asia—Cambodia, Laos, Myanmar, and Vietnam (CLMV)—over 2000–2021, conditional on other external inflows including foreign direct investment (FDI), official development assistance (ODA), and trade openness. Employing a nonlinear Autoregressive Distributed Lag (N-ARDL) model with a Dynamic Fixed Effects (DFE) estimator, this study estimates short- and long-run regime-differentiated associations between GDP growth regimes and remittances to GDP, controlling for foreign direct investment (FDI), official development assistance (ODA), and trade openness. GDP growth is decomposed into above- and below-median regimes, allowing the model to examine whether remittance dynamics differ across growth upswings and downturns. Panel estimates are complemented with dynamic multipliers that trace conditional adjustment paths over different horizons. The results reveal a high-growth-driven regime pattern rather than formal statistical evidence of unequal high- and low-growth coefficients. In the long run, above-median growth significantly reduces remittances to GDP (${\widehat{\theta }}_1=-0.130$, very strong evidence), consistent with the household insurance motive; below-median growth has no significant long-run association (${\widehat{\theta }}_2=-0.127$, no evidence). In the short run, above-median growth is positively associated with remittances (${\widehat{\tilde{\beta }}}_1^{+}=0.033$, very strong evidence), while below-median growth again shows no significant short-run response (${\widehat{\tilde{\beta }}}_1^{-}=0.051$, no evidence). Formal Wald tests do not reject equality between the high- and low-growth coefficients in either horizon; therefore, the findings should be interpreted as a regime-differentiated significance pattern within a nonlinear specification, not as formal proof of coefficient asymmetry. Taken together, these responses are consistent with a one-sided counter-cyclical interpretation of remittances: remittances to GDP decline when domestic growth is above the median, while no significant adjustment is observed during below-median growth episodes. The pattern documented here is therefore driven by the high-growth regime and should not be read as evidence of an active counter-cyclical surge during downturns. Trade openness and ODA exhibit significant positive short-run co-movement with remittances, whereas FDI shows a strong positive long-run association with remittances to GDP. The novelty of this study lies in providing new panel evidence on regime-differentiated remittance–growth associations for CLMV within a nonlinear N-ARDL and dynamic multiplier framework, while transparently reporting that formal Wald tests do not reject equality between high- and low-growth coefficients. Policy implications center on facilitating reliable remittance channels—reducing transfer costs and expanding financial inclusion—without assuming that remittance inflows automatically rise during downturns. Full article

Background: Velocity loss (VL) is widely used in velocity-based training (VBT) to index mechanical fatigue, yet attentional focus cues may alter velocity profiles and their relationship with internal load. This study tested whether internal focus, external focus, or control modifies repetition-level velocity, lactate kinetics, and lactate–VL% coupling during bench press (BP) at 60% one-repetition maximum (1RM). Methods: Thirty-six trained men were randomized into three groups. Thirty-four participants completed the study and were included in the final analyses according to outcome-specific data availability. Participants completed two counterbalanced sessions on a Smith machine BP: (i) a single set to technical failure, and (ii) a conventional 3 sets × 10 repetitions at 60% 1RM. Concentric velocity was recorded via a linear position transducer and analyzed at the repetition level using linear mixed-effects models. Lactate was analyzed via Gaussian generalized estimating equations (GEEs). Results: Repetitions to failure and terminal velocity at failure did not differ between groups (Welch p = 0.328; ω² = 0.045). During 3 sets × 10 repetitions, velocity decreased across sets and repetitions (both p < 0.001); adding group terms improved fit (LR χ²(12) = 42.26, p < 0.001), with additional improvement for group-dependent fatigue patterns (LR χ²(6) = 14.90, p = 0.021). Lactate increased over time (Wald χ²(4) = 244.56, p < 0.001) with convergence by post-lactate set 3 and post-lactate 30 s. Lactate–VL% coupling was strongly moderated by group (post-lactate × group: χ²(2) = 80.42, p < 0.001), with slopes (ΔVL% per 1 mmol·L⁻¹) of 5.27 (internal focus), 13.60 (external focus), and 0.04 (control). After Holm correction across prespecified primary outcomes, only the post-session rating of perceived exertion differed (pHolm = 0.004; ω² = 0.045), with higher values in the external focus group. Pairwise effects were calculated as comparator minus external focus; therefore, negative g values indicate a higher rate of perceived exertion (RPE) in the external focus group (gHedges ≈ −1.50 vs. control; −1.37 vs. internal focus). Conclusions: Attentional cueing did not consistently alter averaged VL% outcomes after multiplicity correction, but it was associated with differences in early lactate kinetics and modified the observed association between post-set lactate and VL% in the interaction-based coupling model. Cueing scripts should therefore be reported verbatim and standardized in VBT studies, particularly when VL-derived indices are interpreted alongside internal load markers. Full article

The relationship between blood glucose levels and blood pressure is well established in clinical literature, yet its precise quantitative characterization, including nonlinear effects, threshold phenomena, and demographic modifiers, remains incompletely understood. In this study, we conducted a comprehensive cross-sectional analysis of the National Health and Nutrition Examination Survey (NHANES) spanning 11 survey cycles (1999–2023), comprising 54,881 adult participants with at least one glycemic marker and standardized blood pressure measurements. Of these, 26,981 had valid fasting plasma glucose (FPG) measurements, and 49,327 had valid glycated hemoglobin (HbA1c) measurements. We employed restricted cubic splines (RCS), generalized additive models (GAMs), and segmented regression to characterize the dose–response relationship between glycemic markers and both systolic (SBP) and diastolic blood pressure (DBP). A 10 mg/dL increase in FPG was associated with a 0.32 mmHg increase in SBP (95% CI: 0.26–0.38, p < 0.001) after adjusting for age, sex, and body mass index (BMI). Nonlinearity was statistically significant for all exposure–outcome combinations (p < 10⁻⁷ for Wald tests). Segmented regression identified a FPG breakpoint at 122.1 mg/dL (95% CI: 119.5–125.6), below which SBP increased at 0.39 mmHg per mg/dL and above which the association was essentially flat. Stratified analyses revealed that the glucose–BP association was strongest in females (β = 0.048 per mg/dL) compared with males (β = 0.021), and in prediabetic individuals (β = 0.065) compared with those with established diabetes (β = 0.014). In the statistical mediation decomposition, body mass index accounted for 23.5% of the total FPG–SBP association. A significant FPG × BMI interaction (p < 0.001) indicated that the glucose–BP relationship is modulated by adiposity. These findings provide a large-scale population-level analysis of the glucose–blood pressure dose–response relationship and identify potential thresholds warranting further investigation for integrated cardiometabolic risk management (95% bootstrap CI: 19.3–28.9%; 1000 resamples); given the cross-sectional design and BMI’s plausible role as a shared upstream determinant of glucose and blood pressure, this proportion is reported as a confounding decomposition rather than as evidence of causal mediation. Insulin resistance (HOMA-IR) and C-reactive protein did not contribute significantly as additional decomposition pathways. Full article

This paper introduces a rank-based panel kink threshold regression model with a covariate-dependent threshold, where the threshold is specified as a function of informative covariates. To estimate the model parameters, we propose a profile estimation procedure for both the threshold parameters and regression coefficients. Additionally, we develop a Wald test statistic to examine the constancy of the threshold and a sup-score test to detect the presence of the kink effect. Through simulation studies and an empirical analysis, we demonstrate that the proposed methods exhibit robustness against outliers and heavy-tailed errors in both parameter estimation and hypothesis testing. Full article

Background: Parkinson’s disease (PD) is clinically heterogeneous, yet the genetic architecture underlying this heterogeneity remains incompletely understood. We examined the genetic correlates of four complementary PD subtyping frameworks: the clinical motor subtype (tremor-dominant [TD] vs. postural instability/gait difficulty [PIGD]), alpha-synuclein seed amplification assay status (SAA+ vs. SAA−), the pathological subtype (brain-first vs. body-first, based on the presence of REM sleep behavior disorder), and the data-driven subtype (diffuse malignant [DM] vs. mild-motor predominant [MMP] vs. intermediate [IM]). Methods: We analyzed 1390 PD patients from the Parkinson’s Progression Markers Initiative (PPMI) with genotypes available for seven PD-associated genes (LRRK2, GBA1, SNCA, PRKN, PINK1, PARK7, VPS35), including specific variant resolutions (LRRK2 G2019S, R1441G/C/H; GBA1 N409S, severe variants; SNCAA53T), and APOE (ε2/ε3/ε4 alleles). Genetic variant frequencies were compared across subtypes using chi-square or Fisher’s exact tests with the Benjamini–Hochberg false discovery rate (FDR) correction. Effect sizes were quantified using Cramér’s V. multivariable logistic regression estimated adjusted odds ratios with Wald-based 95% confidence intervals. Results: Among genotyped PD patients, LRRK2 carriers constituted 13.7% (190/1390; 170 G2019S, 18 R1441G/C/H), GBA1 8.6% (119/1390; 96 N409S, 23 severe), and SNCA 2.0% (28/1390; all A53T). APOE ε4 carriers comprised 23.4% (323/1380). SAA-negative patients were markedly enriched for LRRK2 variants (37.1% vs. 10.2%, p = 3.7 × 10⁻¹⁹, q < 0.001, V = 0.25), specifically G2019S (28.5% vs. 9.6%, p = 4.9 × 10⁻¹¹, q < 0.001) and R1441G/C/H (7.9% vs. 0.5%, p = 2.7 × 10⁻¹², q < 0.001). Body-first PD was enriched for GBA1 carriers (12.3% vs. 6.7%, p = 0.004, q = 0.021) and had less LRRK2 carriers (7.9% vs. 15.0%, p = 0.002, q = 0.013). The DM subtype had the highest GBA1 frequency (14.0% vs. MMP 5.9%, p < 0.001, q = 0.003). After FDR correction, 10 out of 48 univariate tests remained significant. Clinical subtypes (TD vs. PIGD) showed only nominal LRRK2 differences that did not survive FDR correction. The APOE genotype did not differ across any framework. Conclusions: PD subtypes defined by alpha-synuclein pathology (SAA), pathological onset pattern (brain-first/body-first), and data-driven classification (DM/MMP/IM) show distinct genetic profiles that survive multiple comparison correction. LRRK2 variants strongly associate with SAA negativity (V = 0.25); GBA1 variants associate with the severe body-first onset and the diffuse malignant subtype. Full article

This article provides a selective review of offline change-point detection methods, with a particular emphasis on weak change-points. The study of such weak changes plays a central role in establishing the asymptotic properties of test statistics designed for detecting fixed (non-vanishing) changes. In addition, it is crucial for analyzing the asymptotic behavior of change-point location estimators. We review the current state of the literature, identify key limitations, and outline promising directions for future research in this challenging setting. Full article

Vocational high school students represent a substantial yet understudied population in school-based mental health research. Drawing on positive psychology and bioecological theory, this study examined whether personal growth initiative (PGI) shows a statistical indirect effect with respect to the relationships between multidimensional school climate and mental health outcomes among Chinese vocational students. Participants were 14,006 students from 112 vocational high schools. Two-level path models simultaneously entered different climate dimensions to estimate their unique associations with PGI, depressive symptoms, and Subjective well-being (SWB) at the within- and between-school levels, controlling for gender and socioeconomic status. Within schools, Safety, Interpersonal Relationships, Rules and Norms/Career Development Support, and Teaching and Learning/Diversity were positively associated with PGI, which in turn was associated with lower depressive symptoms and higher SWB. Wald tests indicated that Safety showed the strongest overall association with depressive symptoms, whereas Interpersonal Relationships showed the strongest overall association with SWB. At the between-school level, school-average climate and school-average PGI were associated with both outcomes, although these findings should be interpreted cautiously given the limited between-school power and substantial overlap among aggregated climate indicators. Overall, the findings are consistent with PGI being an important student-level pathway linking school climate to mental health in vocational education. Full article