Search Results (805)

We present a quantitative theory of contraction and expansion cycles within the Quantum Memory Matrix (QMM) cosmology. In this framework, spacetime consists of finite-capacity Hilbert cells that store quantum information. Each non-singular bounce adds a fixed increment of imprint entropy, defined as the cumulative quantum information written irreversibly into the matrix and distinct from coarse-grained thermodynamic entropy, thereby providing an intrinsic, monotonic cycle counter. By calibrating the geometry–information duality, inferring today’s cumulative imprint from CMB, BAO, chronometer, and large-scale-structure constraints, and integrating the modified Friedmann equations with imprint back-reaction, we find that the Universe has already completed $N_{\mathrm{past}}=3.6\pm 0.4$ cycles. The finite Hilbert capacity enforces an absolute ceiling: propagating the holographic write rate and accounting for instability channels implies only $N_{\mathrm{future}}=7.8\pm 1.6$ additional cycles before saturation halts further bounces. Integrating Kodama-vector proper time across all completed cycles yields a total cumulative age $t_{\mathrm{QMM}}=62.0\pm 2.5\mathrm{Gyr}$, compared to the $13.8\pm 0.2\mathrm{Gyr}$ of the current expansion usually described by $\mathrm{\Lambda }$CDM. The framework makes concrete, testable predictions: an enhanced faint-end UV luminosity function at $z\gtrsim 12$ observable with JWST, a stochastic gravitational-wave background with $f^{2/3}$ scaling in the LISA band from primordial black-hole mergers, and a nanohertz background with slope $\alpha \simeq 2/3$ accessible to pulsar-timing arrays. These signatures provide near-term opportunities to confirm, refine, or falsify the cyclical QMM chronology. Full article

Introduction: Nowadays, there is evidence regarding a beneficial effect of heat on neuromuscular strength and muscle hypertrophy development. The aim of this study is to evaluate the effects of a 4-week passive sauna bathing program to extreme heat (100 ± 2 °C) as a support for a resistance strength training program on maximal strength and body composition. Methods: 30 young male subjects participated in the study. They were randomly assigned to a Hyperthermia group (HG, n = 14; age: 20.48 (19.12–22–30) years; weight: 76.30 (71.00–79.00) Kg; BMI: 23.92 (22.93–24.87) Kg/m²), or to a Normothermia group (NG, n = 15; age: 19.95 (19.10–21–94) years; weight: 61.70 (59.45–72.90) Kg; BMI: 21.56 (20.42–23.26) Kg/m²). All participants followed the same lower limb strength training program (2 exercises; 4 sets of 10 repetitions at 75% 1RM with progressive loading). Additionally, HG underwent two weekly sessions of exposure to extreme heat in a sauna (100 ± 2 °C and 24 ± 1% relative humidity, four sets of 10 min, 2 days per week). The intervention lasted for 4 weeks, followed by a 4-week deconditioning period. Maximum isometric knee flexion-extension strength, maximum counter-resistance strength, as well as body composition and anthropometric variables were assessed. Results: The HG group significantly increased body weight (p < 0.05) and muscle mass (p < 0.05), while their sum of six skinfolds (Σ6 skinfolds) significantly decreased (p < 0.05). Both groups improved their 1RM squat performance following the intervention program (p < 0.05; HG: r = 0.86; NG: r = 0.89). However, only the HG group continued to improve their squat 1RM after the deconditioning period (p < 0.001; r = 0.93), as well as their leg press 1RM (p < 0.01; r = 0.94). Maximal isometric strength increased only in the NG group at the end of the training program, with a significant increase in knee flexion torque (p < 0.05; r = 0.76). In contrast, the HG group showed significant increases in isometric strength after the deconditioning period in both knee extension (p < 0.05; r = 0.76) and knee flexion (p < 0.05; r = 0.75). Conclusions: A four-week period of passive sauna bathing at extreme heat appears to alter the chronology of strength responses. It also seems to induce favorable responses in terms of strength development and body composition. Full article

Background: In elite football, understanding how age impacts players’ physical performance is essential for optimizing training, career longevity, and team management. Objectives: This study aimed to compare variations in physical capabilities of professional football players by chronological age and identify peak performance ages. Methods: Data from 5203 match performances across 351 official games were analyzed, involving 98 male players aged 18–39 years. Physical capacities (speed, explosive actions, and endurance) were assessed using the Catapult VECTOR7 system. Results: showed that players over 32 years experienced declines in high-intensity and explosive actions, while endurance remained relatively stable with age. Peak performance occurred around 25.7 years for speed, 24.8 years for endurance, and 26 years for explosiveness. Conclusions: Overall, players aged 17–26 years demonstrated the highest physical performance, with notable declines observed in older age groups. Full article

Objective: The objective was to evaluate the ability of Comprehensive Geriatric Assessment (CGA) parameters to predict all-cause mortality in older adults using both traditional statistical methods and machine learning (ML) approaches. Methods: A total of 1.974 older adults from a university hospital outpatient clinic were included in this study. Ninety-six CGA-related variables encompassing functional and nutritional status, frailty, mobility, cognition, mood, chronic conditions, and laboratory findings were assessed. Cox proportional hazards regression and six ML algorithms (logistic regression, support vector machine, decision tree, random forest, extreme gradient boosting, and artificial neural networks) were employed to identify mortality predictors. Model performance was evaluated using area under the curve (AUC), sensitivity, and F1-score. Results: During a median follow-up of 617 days (interquartile range [IQR]: 297–1015), 430 participants (21.7%) died. Lower Lawton instrumental activities of daily living scores, unintentional weight loss, slower gait speed, and elevated C-reactive protein levels were consistent mortality predictors across all models. The artificial neural network demonstrated the highest predictive performance (AUC = 0.970), followed by logistic regression (AUC = 0.851). SHapley Additive explanations (SHAP) analysis confirmed the relevance of these key features. Conclusions: CGA parameters provide robust prognostic information regarding mortality risk in older adults. Functional decline and inflammation markers offer greater predictive power than chronological age alone in assessing overall health and survival probability. Full article

Background: Adults with developmental disabilities often experience accelerated aging, but the magnitude of this phenomenon is not well quantified. This study aimed to measure the disparity in functional ability and chronic illness prevalence between adults with developmental and other disabilities. Methods: A “functional age” was calculated for adults with developmental disabilities. This metric, designed as a statistical index of disparity, was derived from normative regression models of ADL and IADL based on a reference group of adults with other disabilities. Results: A profound gap was found between chronological and functional age. On average, a 44-year-old individual with a developmental disability exhibited a level of functional limitation equivalent to a person over 100 years older in the reference population for both ADL and IADL (p < 0.001). Conclusions: Accelerated aging in this population manifests as a severe, early onset functional disadvantage rather than an elevated burden of general chronic disease. Policies should shift toward function-based, not age-based, models of care to address these lifelong support needs. Full article

Background: Dental age (DA) estimation, which is widely used in orthodontics, pediatric dentistry, and forensic dentistry, predicts chronological age (CA) by assessing tooth development and maturation. Most methods rely on radiographic evaluation of tooth mineralization and eruption stages to assess DA. With the increasing adoption of large language models (LLMs) in medical sciences, use of ChatGPT has extended to processing visual data. The aim of this study, therefore, was to evaluate the performance of ChatGPT-4 in estimating DA from panoramic radiographs using three conventional methods (Nolla, Haavikko, and London Atlas) and to compare its accuracy against both orthodontist assessments and CA. Methods: In this retrospective study, panoramic radiographs of 511 Turkish children aged 6–17 years were assessed. DA was estimated using the Nolla, Haavikko, and London Atlas methods by both orthodontists and ChatGPT-4. The DA–CA difference and mean absolute error (MAE) were calculated, and statistical comparisons were performed to assess accuracy and sex differences and reach an agreement between the evaluators, with significance set at p < 0.05. Results: The mean CA of the study population was 12.37 ± 2.95 years (boys: 12.39 ± 2.94; girls: 12.35 ± 2.96). Using the London Atlas method, the orthodontists overestimated CA with a DA–CA difference of 0.78 ± 1.26 years (p < 0.001), whereas ChatGPT-4 showed no significant DA–CA difference (0.03 ± 0.93; p = 0.399). Using the Nolla method, the orthodontist showed no significant DA–CA difference (0.03 ± 1.14; p = 0.606), but ChatGPT-4 underestimated CA with a DA–CA difference of −0.40 ± 1.96 years (p < 0.001). Using the Haavikko method, the evaluators underestimated CA (orthodontist: −0.88; ChatGPT-4: −1.18; p < 0.001). The lowest MAE for ChatGPT-4 was obtained when using the London Atlas method (0.59 ± 0.72), followed by Nolla (1.33 ± 1.28) and Haavikko (1.51 ± 1.41). For the orthodontists, the lowest MAE was achieved when using the Nolla method (0.86 ± 0.75). Agreement between the orthodontists and ChatGPT-4 was highest when using the London Atlas method (ICC = 0.944, r = 0.905). Conclusions: ChatGPT-4 showed the highest accuracy with the London Atlas method, with no significant difference from CA for either sex or the lowest prediction error. When using the Nolla and Haavikko methods, both ChatGPT-4 and the orthodontist tended to underestimate age, with higher errors. Overall, ChatGPT-4 performed best when using visually guided methods and was less accurate when using multi-stage scoring methods. Full article

Sucking is essential for feeding and impacts the development of the cranio-facial-respiratory complex (CFRC). Non-nutritive sucking on a pacifier causes palatal narrowing and modifies the natural balanced relationship between intraoral pressure, peristaltic action of the tongue and the palate. Advanced engineering models have shown that malocclusions caused by pacifier use, are often a result of improper sizing. The sizing of pacifiers has historically been based on chronological age. Chronological age is not a size metric. Undersized pacifiers in a baby’s mouth can cause growth complications, palatal collapse airway incompetence and other orthodontic problems that can last a lifetime. Technical advances in facial anthropometrics and predictability of the rapid growth of the infant palate, can guide recommendations for pacifier size and design. This encourages change to a model of biometric sizing. Smartphone applications are being developed that use Ai and machine learning can predict conformity between palatal width and pacifier width. Full article

In this work, we provide an overview of the age determination methods of amphibians and reptiles, critically evaluating their methodological principles, utility (including range of applicability), as well as experimental and biological limitations. Potentially, the most reliable age estimation method is the capture–mark–recapture (CMR) technique, allowing a precise chronological age estimation of wild individuals. However, this is a time-consuming method and is not always applicable. Among the indirect methods of age estimation, skeletochronology is one of the most reliable techniques and has been successfully applied in numerous species of amphibians and reptiles. Skeletochronology is based on the interpretation of the growth marks (especially lines of arrested growth or LAGs) that form in hard-mineralized tissues. Other indirect methods such as the counting of growth marks on epidermal scutes, dermal scales, and claw sections have shown to be less reliable and/or have a more limited range of applicability. Recently, the estimation of chronological age using molecular methods has acquired new perspectives from different approaches. Among them, measurements of telomere length and DNA methylation represent promising and minimally invasive methods, but their effective use requires further refinement and testing on a larger number of species. Full article

Global climate change is driving profound transformations in forest ecosystems, particularly in monsoon-influenced regions of the Pacific coast of Asia, such as the Sikhote-Alin Mountains. Long-lived conifer species, notably Korean pine (Pinus koraiensis Siebold & Zucc.), play a central ecological role in mixed broadleaf–coniferous forests of the region. We examined how the radial growth response of Korean pine to climatic variability changes with tree age and ontogenetic stage, using 191 increment cores from trees ranging from early virginile to old generative stages. We employed two approaches: (i) a stage-based analysis, constructing tree-ring chronologies for each ontogenetic stage; (ii) an individual-tree analysis, applying correlation and regression directly to individual ring-width series. Climate–growth relationships were assessed using monthly temperature, precipitation, and drought indices (PDSI, SPEI). For the stage-based approach, radial growth was positively correlated with the mean August temperature of the previous year (up to r = 0.61), minimum November temperature (up to r = 0.50), and summer drought indices (up to r = 0.57). Age-related trends in climate sensitivity, assessed from regression models under both approaches, were significant for 9 of the 18 monthly climate variables examined. For stage-specific chronologies, simple regressions across six ontogenetic stages described up to 98% of the variance, whereas cambial-age-based relationships were much weaker (R² = 0.03–0.14). These findings highlight the importance of accounting for ontogenetic structure in dendroclimatic analyses and climate reconstructions. Such insights are critical for understanding long-term forest dynamics and informing climate adaptation strategies in Korean pine-dominated ecosystems. Full article

Recently, senescent T cells in the peripheral blood have been detected using senescence-associated β-galactosidase (SA-βGal) activity and have been used as an endpoint in clinical trials. However, the epidemiological association between the abundance of SA-βGal-stained senescent CD8+ T cells and chronological age has not been fully elucidated. To examine the correlation between the proportion of SA-βGal^high CD8+ T cells and age, we analyzed previously collected clinical trial data. We conducted a cross-sectional analysis of 632 Japanese adults aged 40–59 years who participated in the screening phase of a clinical trial. To characterize senescent CD8+ T cells, we measured the proportion of SA-βGal^high in total CD8+ T cells and each subset—naïve, central memory (TCM), effector memory (TEM), and terminally differentiated effector memory (TEMRA). We then calculated the correlation coefficients between the proportion of SA-βGal^high CD8+ T cells and age. The proportion of SA-βGal^high cells in total CD8+ T cells, naïve, TCM, TEM, and TEMRA CD8+ T cells increased significantly with age. In Japanese adults, the proportion of SA-βGal^high in CD8+ T cells may serve as a useful biomarker of immune senescence. Full article

Background/Objectives: Vision plays a key role in acquiring and automating fundamental movement skills. Evidence from Italy is scarce. This study compared Test of Gross Motor Development–2 (TGMD-2) performance between Italian children with visual impairment (VI) and sighted peers and explored differences by degree of VI (severe VI vs. blindness). Methods: This was a cross-sectional study including 38 children (VI: n = 19, 5–12 y; sighted: n = 19, 5–11 y). VI was classified per the WHO criteria. TGMD-2 was administered with adaptations suitable for VI (e.g., high-contrast cones, auditory balls, verbal cueing). Group differences (VI vs. sighted; blindness vs. severe VI; severe VI vs. sighted) were analyzed with Mann–Whitney U (α = 0.05). For participants > 10 y, raw scores were analyzed and age-equivalent scores were summarized to calculate developmental gaps. Results: Children with VI scored lower than sighted peers on locomotor, object control, and total TGMD-2 scores (all p < 0.001). Within VI, blindness was associated with lower locomotor, object control, and total scores than severe VI (p = 0.013; p = 0.043; p = 0.013). Children with severe VI also scored lower than sighted peers across outcomes (all p < 0.001). Based on age-equivalent estimates, average gross motor performance in VI was ~4–5 years below chronological age; values < 3 years were set to 3 years for calculation (the floor effect). Conclusions: Italian children with VI show reduced gross motor competence compared with sighted peers, with a substantial developmental lag. Findings support early adapted physical education and structured movement opportunities to promote participation and inclusion. Future studies should examine long-term outcomes and contextual factors shaping motor competence in youth with VI. Full article

In recent years, China has invested substantial funds in ecological restoration, achieving significant accomplishments. The forest coverage rate in the Chengde Bashang area, located in the transitional zone between the monsoon and non-monsoon regions, has now reached 82%. However, the area has also encountered a series of environmental issues, including lake shrinkage, soil salinization, and large-scale die-offs of planted forests. Whether the forests in this region can achieve sustainable development in the future, and whether ecological restoration should prioritize tree planting or grass cultivation, are critical questions that require attention. By studying the historical vegetation dynamics in afforested areas, we can better understand the relationship between climatic environmental changes and vegetation, providing baseline data for future ecological restoration. This study utilized AMS ¹⁴C dates to establish a chronological framework for the core and employed pollen to investigate vegetation dynamics over the past 5000 years in the artificial Larix Mill. forest area. The vegetation and environmental history of this core can be divided into three zones: Zone 1 (5100–4100 a B.P.): vegetation was dominated by pine and spores, with low herbaceous pollen content. Zone 2 (4100–1400 a B.P.): vegetation was primarily herbaceous. Zone 3 (1400 a B.P.–present): arboreal pollen content increased slightly, but herbaceous plants remained dominant. This period included the warm–dry Medieval Warm Period (1400–900 a B.P.), the cold–humid Little Ice Age (900–300 a B.P.), and the recent 300 years of anthropogenic disturbance. Notably, the large-scale afforestation efforts in recent decades are clearly reflected in the profile. A comparative analysis of records from the monsoon–non-monsoon transition zone reveals that, except for Angulinao Lake, other records were dominated by herbaceous vegetation over the past 2000 years. Additionally, the Mu Us Sandy Land, Hunshandake Sandy Land, Hulunbuir Sandy Land, and Horqin Sandy Land in China have experienced aeolian sand accumulation over the same period. Given the anticipated warming–desiccation trend, phytoremediation strategies should favor xerophytic shrubs and herbaceous over monospecific forest plantations. Full article

Geological data of the region indicate that the Canary Islands have not been connected to the mainland before. However, fossil evidence suggests some kind of faunal exchange with Africa during the late Neogene. After extensive field work during past years, a re-evaluation of the fossil remains of the first terrestrial vertebrates that settled and thrived on the Canary Islands is presented, with special attention to the long-debated identity of birds that laid large-sized eggs, reported some decades ago on Lanzarote Island. The age of the eggshell-bearing deposits has been recently updated as Early Pliocene (ca. 4 Ma). The dispersal mode of these terrestrial birds to reach the island was an unsolvable challenge in previous studies because the regional geography of the sea bottom was neglected, as well as the chronological succession of events in the formation of the Canary Eastern Ridge, which increased attention to a unique case of arrival of ratites on an island never before united with the mainland. The few animals found in northern Lanzarote (ratites, snakes, turtles, terrestrial snails and bite marks on eggshells pointing to a jagged and unknown large predator) probably made the sea crossing from the mainland in different ways. Two scenarios are contemplated. In both, the circumstances facilitating the faunal transit from Africa to the Canaries ceased after the early Pliocene, around 4 Ma, since these animals have never managed to cross the Canary Channel again. Full article

Background/Objectives: Anxiety is a hallmark feature of Williams syndrome (WS), with very high prevalence rates of generalised anxiety disorder (GAD) and specific phobias in both school-aged children and adults, yet a relatively lower prevalence of social phobia. There is very limited research on anxiety in very young children with WS, and no study to date has examined the early prevalence and development of different anxiety disorders in WS. The present research provides a comprehensive assessment of the prevalence and longitudinal profile of anxiety symptomology in very young children with WS. Potential environmental and demographic correlates of anxiety symptomology were also explored. Methods: Participants included 19 young children with WS, aged between 2 and 5 years (at initial testing), who completed a comprehensive developmental assessment. Parents/guardians also completed the Spence Children’s Anxiety Scale (SCAS; Spence, 1997 & Spence et al., 2001), a standardised, psychometrically robust anxiety questionnaire (commonly utilised in research and clinical settings) that measures anxiety symptomology for various anxiety disorders present in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5; American Psychiatric Association, 2013). Results: The present research found anxiety symptomology to be highly prevalent in very young children with WS, particularly GAD and specific phobia. Moreover, the prevalence of anxiety symptomology increased with age and over time, with many children developing comorbid anxiety disorder symptoms approximately 3.5 years later, at Time 2. Chronological age, sex, and developmental/intellectual capabilities were also found to impact on the developmental trajectory of anxiety in young children with WS. Conclusions: The longitudinal findings provide evidence for the contribution of environmental factors on the nature, developmental course, and maintenance of anxiety. Considerable individual variability was apparent, confirming the importance of individual assessments and developing individualised treatment programmes for those with WS. Full article

Aging, a state of progressive decline in physiological function, is an important risk factor for chronic diseases, ranging from cancer and musculoskeletal frailty to cardiovascular and neurodegenerative diseases. Understanding its cellular basis is critical for developing interventions to extend human health span. This review highlights the crucial role of in vitro models, discussing foundational discoveries like the Hayflick limit and the senescence-associated secretory phenotype (SASP), the utility of immortalized cell lines, and transformative human induced pluripotent stem cells (iPSCs) for aging and disease modeling and rejuvenation studies. We also examine methods to induce senescence and discuss the distinction between chronological time and biological clock, with examples of applying cells from progeroid syndromes and mitochondrial diseases to recapitulate some signaling mechanisms in aging. Although no in vitro model can perfectly recapitulate organismal aging, well-chosen models are invaluable for addressing specific mechanistic questions. We focus on experimental strategies to manipulate cellular aging: from “steering” cells toward resilience to “reversing” age-related phenotypes via senolytics, partial epigenetic reprogramming, and targeted modulation of proteostasis and mitochondrial health. This review ultimately underscores the value of in vitro systems for discovery and therapeutic testing while acknowledging the challenge of translating insights from cell studies into effective, organism-wide strategies to promote healthy aging. Full article