Institute for Exercise and Environmental Medicine

Burn injuries impair sweating and evaporative heat loss. This project (i) investigated the extent to which the size of a burn injury alters the critical relative humidity (RHcrit) for heat balance during exercise-heat stress among burn survivors with injuries spanning ~20% (n=9), ~40% (n=6), and ~60% (n=9) total body surface area (TBSA), and (ii) compared RHcrit values between burn survivors and 10 non-injured individuals with simulated burns of 20%, 40%, and 60% TBSA. Participants cycled (heat production: 192 ± 17 W·m-2) in 40°C and 24% relative humidity for 30 min, after which relative humidity increased 3% every 5 min until an upward inflection in esophageal temperature. RHcrit averaged 41.3 ± 6.6% and 30.2 ± 3.8% in burn survivors with 20% and 40% injuries, respectively, and averaged 40.7 ± 5.3%, 38.2 ± 4.8%, and 31.73 ± 4.3% in non-injured individuals with 0%, 20%, and 40% TBSA simulated burn injuries, respectively. There was a significantly higher probability of achieving RHcrit sooner (i.e., at a lower relative humidity) with larger actual and simulated injuries up to 40% TBSA (P < 0.001). Notably, esophageal temperature never reached a stable plateau, and thus RHcrit could not be determined, in half of participants with 40% TBSA actual and simulated injuries, likely reflecting the influence of burn size plus other factors that influence thermolytic capacity. No participants exhibited an RHcrit with a 60% TBSA injury (actual or simulated), indicating that 60% TBSA injuries are too large to permit heat balance at even the lower relative humidity tested. Higher %TBSA injuries lead to lower RHcrit values, with no difference between simulated and actual burn injuries.

Endurance training elicits profound cardiovascular adaptations, including lower heart rate (HR), greater stroke volume (SV), and enhanced aortic Windkessel function. This study aimed to investigate cerebral blood and cerebrospinal fluid (CSF) flow dynamics in endurance athletes and their relations with cardiovascular parameters. Fifteen young male endurance athletes were compared with 19 age-matched sedentary male controls. In the resting supine condition, CINE phase-contrast MRI acquired the extra- and intracranial cerebral blood and CSF flow waveforms, as well as HR, SV, and ascending aortic cross-sectional area waveform. Cerebral blood and CSF flow volume (mL/beat) and rate (mL/min) were quantified for the full cardiac cycle and separately for systolic and diastolic phases. Aortic cross-sectional area change was temporally integrated to quantify aortic expansion and recoil. Athletes exhibited higher aortic recoil (5.7 cm2·s [4.1, 7.3] vs. 4.1 cm2·s [2.6, 5.6]) and SV (97 ± 18 mL vs. 82 ± 11 mL) and lower HR (53 ± 6 bpm vs. 67 ± 12 bpm) than controls. Total cerebral arterial blood and CSF flow volumes and rates across the full cardiac cycle were similar between groups; however, athletes showed significantly greater diastolic arterial flow volume and lower systolic arterial flow rate. The association between lower HR and greater diastolic arterial flow volume was mediated by higher aortic recoil across all participants. These results suggest that enhanced aortic recoil in endurance athletes sustains diastolic cerebral arterial flow volume across a prolonged cardiac cycle, enabling more efficient brain perfusion with fewer cardiac cycles than sedentary controls.

There is considerable heterogeneity in the thermal and cardiovascular responses to heat stress, even among older adults within a similar age range; hence, age alone may not predict heat-related risks. This variability may be in part explained by differences in cardiorespiratory fitness. We aimed to identify whether left ventricular end-diastolic volume (LVEDV), a characteristic of cardiorespiratory fitness, was associated with core temperatures and heart rate responses in older adults exposed to 3 h of very hot and dry heat stress. We hypothesized that individuals with smaller LVEDV would exhibit higher ending core temperature and heart rates following heat stress. Twenty-two older adults (73 ± 5 yr; 10 females) were exposed to 3 h of very hot and dry ambient heat stress (47°C, 15% relative humidity) with accompanying activities of daily living. We assessed thermal and cardiovascular responses at baseline and end-heating. End core temperature ranged from 37.4°C to 38.9°C, whereas end heart rate ranged from 53 to 113 beats/min. Baseline LVEDV was associated with end-heating core temperature (β = -0.018, SE = 0.004; P = 0.003) after controlling for body surface area and baseline core temperature. Likewise, LVEDV was associated with end-heating heart rate (β = -0.595, SE = 0.126; P < 0.001), after controlling for body surface area. However, LVEDV was not associated with whole body sweat rate (P = 0.100) or the change in forearm blood flow (P = 0.331) indexed to changes in core temperature. These findings suggest that individuals with small LVEDV may be susceptible to hyperthermia and tachycardia associated with environmental heat stress.NEW & NOTEWORTHY There is considerable heterogeneity in the thermal and cardiovascular responses to heat stress, even among older adults within a similar age range; hence, age alone may not predict heat-related risks. This variability may be in part explained by differences in physical fitness. Our findings show that individuals with low left ventricular end-diastolic volumes have greater core temperature and heart rate responses to environmental heat stress.

Non-communicable diseases are the leading causes of premature mortality worldwide. Both genetic predispositions and environmental exposures affect disease risk. While biobanks have increased understanding of genetic predictors of these diseases, environmental influences are expected to have a greater impact on disease development. Individuals also create their own environments and lifestyles based on genetically regulated preferences, leading to gene-environment interactions that require large datasets to study. Finnish biobanks typically lack sufficient lifestyle and environmental data, which limits their use. We present a protocol for a biobank-recall study (BioRecall) to collect data on lifestyle and environmental exposures and combine these findings with genotypes, biological samples and clinical outcomes. All previously genotyped donors from the Central Finland Biobank who have been diagnosed with type 2 diabetes and have consented to recall will be invited to participate in the pilot study. The preliminary feasibility assessment reveals that there are 1580 suitable candidates. Participants will complete an electronic questionnaire on a secure online platform. The questionnaire includes validated questions on lifestyles, anthropometrics, weight loss history, health, symptoms, work characteristics, emotional states and residential environments. Postcode information will facilitate the addition of spatial environmental data. Genotype and related clinical data will be provided in the study in accordance with the Finnish Biobank Act and combined with questionnaire data. The Human Sciences Ethics Committee of the University of Jyväskylä delivered a favourable statement regarding the study protocol (1671/13.00.04.00/2023). Central Finland Biobank approved the research plan (no: BB24-0333-A01). The data collected will be returned to the Central Finland Biobank for research purposes with the participants' consent. Permission for data usage can then be applied through standard protocols of the Fingenious service (https://site.fingenious.fi/en/). If successful, the study will be expanded to other donors and Finnish biobanks.

Modern DevOps practices have accelerated software delivery through automation, CI/CD pipelines, and observability tooling, but these approaches struggle to keep pace with the scale and dynamism of cloud-native systems.As telemetry volume grows and configuration drift increases, traditional, rule-driven automation often results in reactive operations, delayed remediation, and dependency on manual expertise.This paper introduces Cognitive Platform Engineering, a next-generation paradigm that integrates sensing, reasoning, and autonomous action directly into the platform lifecycle.This paper propose a four-plane reference architecture that unifies data collection, intelligent inference, policy-driven orchestration, and human experience layers within a continuous feedback loop.A prototype implementation built with Kubernetes, Terraform, Open Policy Agent, and ML-based anomaly detection demonstrates improvements in mean time to resolution, resource efficiency, and compliance.The results show that embedding intelligence into platform operations enables resilient, self-adjusting, and intent-aligned cloud environments.The paper concludes with research opportunities in reinforcement learning, explainable governance, and sustainable self-managing cloud ecosystems.

Heart failure with preserved ejection fraction (HFpEF) is characterized by elevated left-ventricular (LV) filling pressures largely owing to diastolic dysfunction and stiffness. The measurement of filling pressure presents unique challenges as cardiac structures live within the context of the thorax. The heart and pulmonary vasculature are therefore subjected to the same changes in external volume as the lung. Here, we review the mechanisms by which LV filling pressure interacts with the thoracic space, with a particular focus on patients with HFpEF during rest and exercise. Specifically, we discuss the means by which intrathoracic volume impacts ventricular filling and function. We outline the interacting compliances within the thoracic cavity which can alter intrathoracic and therefore cardiac filling pressures. We also detail means by which intrathoracic pressure can be modulated by different conditions and body positions, such as supine posture, gravity, and obesity. Throughout, we highlight gaps in the literature as well as perspective towards possible future directions.

Marathon running is known to increase the risk for acute kidney injury (AKI), due to high levels of muscle damage, dehydration, reduced renal filtration and heat stress. The Boston Marathon provides a unique combination of stress for the kidneys due to the net downhill course, variable environmental conditions, and faster finish times compared to other marathon events. PURPOSE: Observe hydration, electrolyte and renal stress biomarkers pre- and post-race. METHODS: Thirty-seven males (52 ± 11 y, 1.72 ± 0.1 m, 3.69 ± .63 hr), and thirty-eight females (38 ± 12 y, 1.67 ± 0.08 m, 3.78 ± .58 hr) provided blood at marathon expo (1-2 days prior to race), urine and body mass pre-race (within 1 hr) and immediately post-race (within 30 min of finishing). Blood samples were analyzed via i-stat CHEM8+ cartridges. Urine was analyzed for specific gravity (USG) via refractometry. Pre- versus post-race differences were evaluated using paired samples t-tests and correlations were run between variables. Significance was set a priori as p < .05. RESULTS: There were significant differences between pre- versus post-race for serum sodium [Na+] (pre: 140 ± 2; post: 142 ± 2 mEq/L), [Cl-] (pre: 101 ± 2; post: 103 ± 3 mEq/L), BUN (pre: 17 ± 4; post: 20 ± 5 mmol/L), creatinine (pre: 0.9 ± 0.2; post: 1.5 ± 0.4 mg/dL), USG (pre: 1.009 ± 0.007; post: 1.016 ± 0.015), and body mass (pre: 64.5 ± 9.8; post: 62.5 ± 9.1 kg) (all p < .001). Serum [K+] was similar at pre- (4.2 ± 0.4 mEq/L) and post-race (4.6 ± 4.0 mEq/L; p = .403). Serum creatinine increased by at least 0.3 mg/dL 69% of our participants. We did not detect sex differences in markers of hydration, electrolytes, or renal stress (all p > 0.08). CONCLUSION: Our data demonstrate increases in markers of renal stress and hypohydration with minor alterations in serum electrolyte balance during the Boston Marathon. Future work is needed to explore AKI risk using more specific, urine-based biomarkers and methods to facilitate recovery following the race. Supported by: This study was funded by the Boston Athletic Association Medical Research Grant Program.