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Abstract Honeybees are master thermoregulators, capable of maintaining nest homeostasis across fluctuating ambient temperatures. When workers must cool their nest, they use multiple thermoregulatory behaviors (e.g., fanning, collecting water), but bearding, where hundreds to thousands of workers evacuate their nest and form a bivouac outside, is relatively unexplored. Here, we (1) describe natural bearding patterns, (2) experimentally manipulate colonies to determine what impacts beard size and timing, and (3) explore how workers dissipate back into their nest. We show that bearding occurs daily in hot weather, but the largest beards consistently happen in the evening/night, between the hours of 1800 and 2400. Beards are located around the nest entrance, but workers bias their position toward the shaded side of the nest box. As colony size increases, beard size and duration also increase, but the proportion of the colony bearding does not increase with colony size. Colonies with and without brood still cast beards; brood presence/absence did not impact beard size or duration. After noticing that beards tend to dissipate at sunrise, we experimentally showed that beards induced in the afternoon dissipate within 1–2 h, whereas beards induced in the evening remain overnight (10+ h). Bearding overnight, however, does carry risks for developing brood inside, as nest temperatures dropped below the optimal range, until the beard dissipated at sunrise. What cues workers use to depart the beard remain unknown, but experimentally illuminating colonies at night did not induce beards to dissipate. Our results suggest that bearding is an individual decision, not one that is coordinated across the colony. Still, these individual actions result in a dramatic collective response that colonies employ to reduce the temperature of their nest. Here, we show how and when colonies use bearding, despite its risks. 

Abstract Distributed acoustic sensing (DAS) is an emerging oceanographic technique in which an interrogator continuously records nanoscale strain of a fiber-optic cable, such as a telecommunication cable, with meter-scale measurement spacing over tens of kilometers. Empirical methods have recently been established for calculating pressure spectra to measure ocean surface gravity wave statistics from DAS strain. Here, we compile data from six submarine DAS experiments to provide a comparison between studies and establish recommendations for using DAS to measure ocean waves. Data were collected from Alaska, Hawaii, Massachusetts, North Carolina, and Oregon, United States, with different interrogators on different cable types in 0–60 m of water with 0–4 m of burial. Ground-truth measurements of ocean waves were provided by standard near-bed or sea surface instruments. The raw strain recorded in each experiment varied over four orders of magnitude, which could not be explained by water depth, wave conditions, or interrogator settings and suggests that cable characteristics and burial depth are important factors controlling strain magnitude and measurement quality. Strain spectra were converted to near-bed pressure spectra using a frequency-dependent, location-specific empirical correction factor, and DAS-derived pressure spectra were used to calculate wave statistics. The correction factors varied over 10 orders of magnitude between sites yet provided accurate calculations of wave height and period (root-mean-square error of 0.2–0.6 m forH_sand 0.2–1.6 s forT_eandT_p). The volume of data necessary for calibration is discussed. This meta-analysis highlights future oceanographic applications of DAS. Significance StatementDistributed acoustic sensing (DAS) is an emerging technology for measuring ocean waves on seafloor fiber-optic cables, such as telecom cables. The advantage of DAS is that it can record thousands of measurements per second at meter-scale spacing over tens of kilometers. We compare six datasets to characterize DAS-derived strain for measuring ocean waves. The differences in strain magnitude observed between datasets were not explained by water depth, wave height or period, or instrument settings. It is likely that cable composition and depth of burial control the magnitude of the recorded strain. Despite these differences, each dataset was empirically calibrated to produce accurate measurements of wave statistics. DAS is a promising new oceanographic technology, and new applications should be explored. 

The synthesis of heavy elements in supernovae is affected by low-energy $(n,p)$and $(p,n)$reactions on unstable nuclei, yet experimental data on such reaction rates are scarce. The SECAR (SEparator for CApture Reactions) recoil separator at FRIB (Facility for Rare Isotope Beams) was originally designed to measure astrophysical reactions that change the mass of a nucleus significantly. We used a novel approach that integrates machine learning with ion-optical simulations to find an ion-optical solution for the separator that enables the measurement of $(p,n)$reactions, despite the reaction leaving the mass of the nucleus nearly unchanged. A new measurement of the ${}^{58}\mathrm{Fe}(p,n){}^{58}\mathrm{Co}$reaction in inverse kinematics with a $3.66\pm 0.12$MeV/nucleon ${}^{58}\mathrm{Fe}$beam (corresponding to $3.69\pm 0.12$MeV proton energy in normal kinematics) yielded a cross-section of $20.3\pm 6.3$ mb and served as a proof of principle experiment for the new technique demonstrating its effectiveness in achieving the required performance criteria. This novel approach paves the way for studying astrophysically important $(p,n)$reactions on unstable nuclei produced at FRIB. Published by the American Physical Society2025 

Bristol Bay in Alaska is home to the world’s largest commercial salmon fishery. During an average fishing season, the population of the Bristol Bay region more than doubles as thousands of workers from out of state converge on the fishery. In the months leading up to the 2020 commercial fishery opening, as the COVID-19 pandemic exploded worldwide, great uncertainty existed about the health risks of opening the fishery. Bristol Bay residents had not yet experienced any cases of COVID-19, yet the livelihoods of most were closely tied to the commercial fishery opening. To better understand how COVID-19 risk perceptions affected decisions to participate in the fishery, we administered an online survey to community members and fishery participants. We collected standard socioeconomic data and posed questions to gauge risk perceptions related to COVID-19. We find that COVID-19 risk perceptions vary across race/ethnic groups by residency and income. People with below median income who are members of minority groups—notably, non-resident Hispanic workers and resident Alaska Native respondents—reported the highest risk perceptions related to COVID-19. This study highlights the important linkages among risk perceptions, socioeconomic characteristics, and employment decisions during an infectious disease outbreak. 

ABSTRACT The progenitor of SN 2023ixf was an ∼104.8 to $$10^{5.0}\, \text{L}_\odot$$ star (∼9 to $$14\, \text{M}_\odot$$ at birth) obscured by a dusty $$\dot{M} \simeq 10^{-5}\, \text{M}_\odot \rm \, yr^{-1}$$ wind with a visual optical depth of τV ≃ 13. This is required by the progenitor spectral energy distribution, the post-SN X-ray and H α luminosities, and the X-ray column density estimates. In Large Binocular Telescope (LBT) data spanning 5600 to 400 d before the supernova (SN), there is no evidence for optical variability at the level of $$\sim 10^3\, \text{L}_\odot$$ in R band, roughly three times the predicted luminosity of the obscured progenitor. This constrains direct observation of any pre-SN optical outbursts where there are LBT observations. However, models of the effects of any pre-SN outburst on the dusty wind show that an outburst of essentially any duration exceeding ∼5 times the luminosity of the progenitor would have detectable effects on the dust optical depth for decades. While the dust obscuration here is high, all red supergiants have dusty winds, and the destruction (or formation) of dust by even short-lived transients will always have long-term effects on the observed brightness of the star because changes in the dust optical depths after a luminous transient occur very slowly.