Paulina Correa-Burrows

In an increasingly urbanized world, understanding pedestrian dynamics during evacuations is critical for ensuring safety and efficiency, for cases like evacuations or venue exiting. This study explores the stochasticity and fractality of pedestrian flows by implementing a simulation strategy that combines both agent-based modeling and cellular automata. We study five distinct movement strategies were the agent will try to follow towards the exit, and each model incorporates three stress levels based on the Yerkes-Dodson Law, which states that optimal performance occurs at a moderate level of arousal. that optimal performance occurs at a moderate level of arousal. Our simulations reveal that stress significantly influences agent behavior, with optimal stress levels enhancing evacuation efficiency while excessive stress leads to erratic movement. Notably, models employing geodesic paths demonstrate more structured movement and fewer collisions. The fractal analysis of trajectories highlights sub-diffusive behavior in constrained environments, while agents with greater spatial flexibility exhibit broader, more variable paths. These findings accentuate the importance of psychological factors and the differences produced by the diversity of movement strategies, in designing safer evacuation protocols. We hope that this type of studies would eventually permit to determine the effective pedestrian strategies, for example through the observed path of individuals.

Sarcopenia, the age-related decline in muscle mass and strength, affects the functional capacity of older adults. Strength training (ST) combined with adequate protein intake is a key element in reversing and improving functional capacity. Protein, especially Whey Protein isolates (WPI), is widely used to improve muscle mass. In contrast, high-protein products, such as protein yogurt (PY), may offer similar benefits for muscle health and drive additional effects on gut health, which is altered in older adults. For this, we aim to compare WP and PY supplementation during ST on body composition, strength, and gut microbiome in untrained older adults. Seventeen untrained adults (60-70 years) were randomized to either consume WP (25 g) or PY (24.5 g) along with an 8-week supervised ST program (3 sessions/week). Initial and final assessments included body composition (BIA), strength (10RM, isokinetic torque, handgrip), gait speed, resting metabolic rate, and gut microbiome (16 S rRNA sequencing). Data were analyzed using repeated-measures ANOVA and diversity metrics. Both groups increased skeletal muscle mass (WP: +0.47 kg; PY: +0.50 kg) and improved strength and gait speed (p < 0.01), with no between-group differences. Fat mass decreased only in WP (p = 0.02), while resting metabolic rate increased in PY (p = 0.03). Microbiome analysis revealed distinct shifts: WP increased the Firmicutes/Bacteroidota ratio and enriched Subdoligranulum, whereas PY enhanced alpha diversity and increased the abundance of Coprococcus. Functional pathway predictions indicated differential enrichment in metabolic and signaling processes. High-protein yogurt and whey protein similarly improve muscle mass, strength, and functional capacity during ST, while exerting distinct effects on gut microbiome composition. Yogurt represents a cost-effective alternative to whey protein and may confer additional gut health benefits.Trial registration: Clinicaltrials.gov identifier NCT06412302. Date of registration 06/05/2024.

Epigenetic clocks estimate biological age, yet evidence linking decelerated epigenetic aging to healthy cognitive performance in community-dwelling older adults is limited. Cross-sectional study within the population-based ALEXANDROS cohort (Santiago, Chile). Healthy Cognitive Agers (HCA) were participants aged ≥80 years who consistently maintained a MMSE score =30 across all cohort assessments. Controls were cognitively normal peers from the same cohort (MMSE 28.5 ± 2.9). Epigenetic age was estimated using the Horvath, GrimAge, and PhenoAge clocks. Epigenetic age acceleration (EAA) was calculated as residuals from regressing control-calibrated epigenetic age on chronological age. DNA methylation-derived telomere length (DNAmTL, kb) was also assessed. Eighty community-dwelling older adults were included (40 HCA and 40 controls). HCA exhibited substantially lower control-calibrated EAA than controls across all clocks, including Horvath (-13.55 ± 5.28 vs 0.00 ± 4.34 years; p < 0.001; Cohen’s d = -2.80), PhenoAge (-9.72 ± 8.37 vs 0.00 ± 4.56 years; p < 0.001; Cohen’s d = -1.44), and GrimAge (-3.16 ± 3.08 vs 0.00 ± 4.14 years; p < 0.001; Cohen’s d = -0.87). HCA also exhibited substantially longer DNAm-derived telomere length (6.39 ± 0.27 vs 5.39 ± 0.21 kb; p < 0.001; Cohen’s d = 4.15). Preserved cognitive performance in late life, based primarily on persistent MMSE performance, is associated with a decelerated biological aging profile in community-dwelling older adults. Although longitudinal studies are required to clarify temporality, these findings are consistent with the hypothesis that DNA methylation-derived epigenetic markers may help characterize healthy cognitive aging trajectories.

Sarcopenia is a muscle disorder characterized by the progressive loss of muscle mass and strength, leading to diminished physical performance. Although primarily associated with aging and chronic diseases, it is increasingly recognized in younger populations, particularly among those with chronic illnesses. Recent evidence suggests that muscle mass and strength deficits can manifest as early as childhood and adolescence, affecting three out of ten adolescents. Pediatric sarcopenia, while challenging to define due to the lack of standardized diagnostic criteria, presents significant health risks, including increased susceptibility to metabolic syndrome and chronic non-communicable diseases. Recent studies have attempted to establish normative values for muscle health in pediatric populations, yet many rely only on assessment of either muscle mass or strength, thus limiting the understanding of overall muscle health. In this context, the interaction between muscle mass, strength, and functionality, herein referred to as the muscle mass-strength-functionality triad (MSFt), is crucial for understanding the onset and progression of pediatric sarcopenia. The present review provides a perspective on concepts and operators defining pediatric sarcopenia and advocates for incorporating novel diagnostic criteria encompassing the MSFt. Furthermore, the importance of physical literacy and the acquisition of fundamental movement skills during childhood is highlighted, as these factors significantly influence long-term muscle health and physical activity levels. Impact This perspective review provides an insightful view of muscle health in children and adolescents centered around the definition of pediatric sarcopenia. We discussed how to understand and describe sarcopenic-like deficits in pediatric populations. We propose the muscle mass-strength-functionality triad as an attribute that describes physical competence and is key to defining pediatric sarcopenia. We suggest the addition of physical literacy and movement competence assessment to the current diagnostic criteria of pediatric sarcopenia.

Importance: It remains unclear whether obesity accelerates biological aging, potentially leading to early-onset chronic diseases.Objective: To investigate the association between long-term obesity and the expression of biochemical aging markers in younger adults.Design, Setting, and Participants: This multiple-events case-control study, conducted from April 5, 2022, to June 29, 2023, was embedded in the Santiago Longitudinal Study, a prospective Chilean birth cohort of adults aged 28 to 31 years among whom health and nutrition data were collected from September 1992 onward.Exposure: Body mass index (BMI) trajectory across the life course, recorded multiple times since birth. Group 1 had healthy BMI across the life course, group 2 had persistent obesity since adolescence, and group 3 had persistent obesity since childhood.Main Outcomes and Measures: Smoothed BMI trajectories (cubic polynomials) were used to estimate obesity duration. Primary outcomes were DNA methylation–based age and telomere length (TL). Secondary outcomes included levels of aging-related cytokines, growth factors, and adipomyokines.Results: In the sample of 205 adults (mean [SD] age, 28.9 [0.6] years; 100 females [49%]), 89 (43%) were in group 1, 43 (21%) in group 2, and 73 (36%) in group 3. Mean (SD) obesity duration was 12.9 (4.8) years in group 2 and 26.6 (2.3) years in group 3. Long-term obesity was associated with adulthood expression of biomarkers denoting antagonistic and integrative aging hallmarks, including mean (SD) hs-CRP (1.69 [2.1] vs 3.67 vs 4.24 [2.4] mg/L; P < .001; f = 0.57 [95% CI, 0.44-0.70]) and IL-6 (log, 0.69 [0.5] vs 1.03 [0.4] vs 0.99 [0.4]; P < .001; f = 0.53 [95% CI, 0.41-0.62]), as well as FGF-21, IGF-1, IGF-2, apelin, and irisin. Cohen f coefficient indicated a large effect size for the association of long-term obesity with adulthood expression of these markers.Conclusions and Relevance: In this multiple-events case-control study, long-term obesity was associated with the expression of biochemical aging markers in adults aged 28 to 31 years, consistent with epigenetic alterations, telomere attrition, chronic inflammation, impaired nutrient sensing, mitochondrial stress, and compromised intercellular communication. In young adults, chronic health issues may emerge from accelerated biological aging associated with long-term obesity.

Here, we present a multi-omics study of type 2 diabetes and quantitative blood lipid and lipoprotein traits conducted to date in Hispanic/Latino populations (n_max = 63,184). We conduct a meta-analysis of 16 type 2 diabetes and 19 lipid trait GWAS, identifying 20 genome-wide significant loci for type 2 diabetes, including one novel locus and novel signals at two known loci, based on fine-mapping. We also identify sixty-one genome-wide significant loci across the lipid/lipoprotein traits, including nine novel loci, and novel signals at 19 known loci through fine-mapping. Next, we analyze genetically regulated expression, perform Mendelian randomization, and analyze association with transcriptomic and proteomic measure using multi-omics data from a Hispanic/Latino population. Using this approach, we identify genes linked to type 2 diabetes and lipid/lipoprotein traits, including TMEM205 and NEDD9 for HDL cholesterol, TREH for triglycerides, and ANXA4 for type 2 diabetes.

Evidence for the association between breastfeeding (BF) duration and later body mass index (BMI) is inconsistent. We explored how BF duration and BF type (exclusive or partial) related to BMI from childhood to young adulthood in a Chilean cohort. Infants were recruited at 6 months between 1994 and 1996 in Santiago, Chile (n = 821). Mothers reported date of first bottle and last BF; anthropometry was measured at 1, 5, 10, 16, and 23 years. We tested whether: (1) type of BF at 6 months (none, partial, exclusive) and (2) duration of exclusive BF (p < 0.05). Our results are in partial accordance with others who have not found a protective effect of longer BF for lower BMI.