Maine Community College System

Chronic hyperoxia during early postnatal development depresses breathing when neonatal rats are returned to room air and causes long-lasting attenuation of the hypoxic ventilatory response (HVR). In contrast, little is known about the control of breathing of juvenile or adult mammals after chronic exposure to moderate hyperoxia later in life. Therefore, Sprague-Dawley rats were exposed to 60 % O2 for 7 days (juveniles) or for 4 and 14 days (adults) and ventilation was measured by whole-body plethysmography immediately after the exposure or following a longer period of recovery in room air. Hyperoxia-treated juvenile rats appeared to hypoventilate when returned to room air (11-13 % lower ventilation and CO2 convection requirement relative to age-matched controls), but chronic hyperoxia did not alter normoxic ventilation in adult rats. In contrast, pretreatment with chronic hyperoxia augmented the HVR in both juvenile rats (+41 %) and adult rats (+28-50 %). The hypercapnic ventilatory response (7 % CO2) also tended to be augmented in adult rats after 14 days of hyperoxia, but this effect was not significant after accounting for variation in metabolic rate (i.e, CO2 convection requirement). These findings confirm that chronic hyperoxia elicits age-specific respiratory plasticity in rats. These age-dependent differences are not caused by a lack of plasticity in adult-exposed rats; rather, there are qualitative differences in the plasticity that is expressed after chronic hyperoxia in neonates, juveniles, and adults as well as differences in its persistence.

Bacteriophage PensacolaC28 is a lytic phage isolated on Microbacterium sp. Casco Bay (NCMA B81), a marine bacterium originally cultured in South Portland, Maine, USA. PensacolaC28 was isolated from an environmental sample collected in Pensacola, Florida, USA. It is a singleton siphovirus with a 16,749 bp genome and contains 24 protein coding genes.

This paper presents a novel deterministic method derived from the RHEA-UCM (Recursive Homeostatic Evolutionary Algorithm – Universal Cellular Model) framework to address the potential blow-up problem in the Navier-Stokes equations. The method integrates recursive entropy modulation and symbolic feedback, modeled through a biologically inspired glyphic architecture. By embedding stabilizing feedback into the functional evolution of fluid states, we demonstrate a tractable bound on energy norms and curvature-induced entropy divergence. The framework is validated through simulation and symbolic benchmarking, with results indicating sustainable regularity and no evidence of finite-time blow-up. 🛡️ RHEA-Core Public Grant v1.0 Creators Roe, Paul (Rights holder) Description “By accessing, using, or distributing any version of this work, you agree that the most current license published by the original author(s) applies retroactively and supersedes all prior licenses or public domain assumptions associated with earlier versions of this work, including but not limited to CC-BY-NC-ND 4.0, open-source metadata tags, or public repository assumptions. Unauthorized use under any former license constitutes a material infringement of the current legal rights of the author.”Full License Text🛡️ RHEA-Core Public Grant v1.0 License Type:Non-Commercial · Attribution · No Derivatives · Symbolic Derivative Clause (Retained)Applies To: All public-facing RHEA-UCM, ZADEIAN-RHEA, and RHEA-CM intellectual property unless explicitly exempted. 1. Grant of UseYou are hereby granted a revocable, non-commercial, non-transferable, and non-sublicensable right to view, reference, and discuss this material for academic, journalistic, technical, or personal enrichment purposes only, provided all terms below are followed. 2. Attribution RequirementsYou must clearly credit all excerpts, summaries, diagrams, or citations with:“© EnigmaticGlitch · RHEA-UCM / ZADEIAN-RHEA Framework · Patent Pending #63/796,404” 3. No Commercial UseYou may not:- Sell, rent, or monetize this work or its derivatives- Use this work in any product or service that derives revenue or brand positioning- Use this work for AI/ML training unless explicitly authorized 4. No DerivativesYou may not:- Translate, alter, remix, or build upon this material- Create alternate frameworks, white papers, or theories that derive substantially similar logic or structure 5. Symbolic Derivative ClauseYou may not re-encode or embed the core principles of this system (e.g. entropy modulation, symbolic trust resealing, recursive glyph modulation, or UCM cosmological recursion) under different glyphs, symbols, or representations. 6. Enforcement & JurisdictionEnforced under:- U.S. Copyright Law (Title 17)- DMCA- U.S. Patent Law (Provisional #63/796,404) Violations may trigger takedowns, cease & desist, and legal damages. 7. Additional Notes- Academic/private reproduction is allowed with attribution.- Breaches terminate all rights. “Trust is not given. It is oscillated into being…”© 2025 · EnigmaticGlitch · All Rights Reserved.

Nest defense in birds is vital for the protection of their young, but can prove energetically costly. Birds often show plasticity in nest defense depending on factors such as threat level, mate presence, nest stage, and body condition. Such factors can vary over temporal extents ranging from a diel cycle to a breeding season or an individual’s lifetime. Understanding diurnal variation in nest defense intensity can be particularly useful when studying a breeding population to help investigators minimize nest disturbance, yet few studies have explored diurnal variation in nest defense intensity. Here we investigated how nest defense by Herring Gulls ( Larus smithsonianus ) varies with time of day. We simulated predatory threat at 26 Herring Gull nests during four different times of day: “Early Morning” (0530-0600), “Late Morning” (1000-1030), “Afternoon” (1400-1430), and “Evening” (1900-1930). Based on previous findings of diurnal activity patterns in a Herring Gull, we predicted that nest defense intensity—measured as aggressiveness of response and latency to calm—would be greater during the early morning and late evening than at other times. Contrary to our prediction, we found that the time of day did not affect nest defense intensity in Herring Gulls. However, independent of time of day, we found that when both mates were present at the nest, aggression scores were elevated. Our results suggest that joint nest defense in Herring Gulls permits greater aggressiveness towards predators, perhaps due to division of labor or lowered risk of complete nest failure if one parent is injured or killed. Further, our results indicate that researchers can minimize nest disturbance and accompanying stress by limiting research activities at Herring Gull nests when both parents are present. ### Competing Interest Statement The authors have declared no competing interest.

Rats exposed to 4 – 14 days of 60% O2 as adults exhibit a modest enhancement of their hypoxic ventilatory response (HVR) (Danielson & Bavis, Physiology 38(S1): 5730119, 2023). To determine whether this plasticity is unique to the HVR or a general increase in excitability of the respiratory control system, we tested the hypothesis that chronic hyperoxia would also enhance the hypercapnic ventilatory response (HCVR). The ventilatory response to 7% CO2 was measured by whole-body plethysmography in adult, Sprague-Dawley rats immediately after 4 and 14 days of exposure to 60% O2 or an equivalent time period in room air. Baseline ventilation and the HCVR were unchanged after 4 days of hyperoxia. The HCVR was increased after 14 days (Treatment × FICO2, P=0.004), with hypercapnic ventilation being approximately 15% greater than in control rats. However, this effect was no longer significant after accounting for variation in metabolic rate, and the HCVR was fully recovered when rats were restudied four weeks after they were returned to room air. In a follow-up experiment, pulse oximetry was performed in isoflurane-anesthetized rats breathing room air or 12% O2. Exposure to 4 – 14 days of 60% O2 did not impair gas exchange, so augmented ventilatory responses likely reflect changes in the neural control of breathing and/or metabolism rather than differences in the levels of hypoxemia and hypercapnia experienced by rats during the tests. In conclusion, chronic hyperoxia elicits plasticity in both the HVR and HCVR of adult rats, but these responses recover in less than one month after rats are returned to room air. Supported by NIH grant P20 GM-103423 (Maine INBRE). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.