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Theory predicts that organisms should diversify their offspring when faced with a stressful environment. This prediction has received empirical support across diverse groups of organisms and stressors. For example, when encountered by Caenorhabditis elegans during early development, food limitation (a common environmental stressor) induces the nematodes to arrest in a developmental stage called dauer and to increase their propensity to outcross when they are subsequently provided with food and enabled to develop to maturity. Here we tested whether food limitation first encountered during late development/early adulthood can also induce increased outcrossing propensity in C. elegans. Previously well‐fed C. elegans increased their propensity to outcross when challenged with food limitation during the final larval stage of development and into early adulthood, relative to continuously well‐fed (control) nematodes. Our results thus support previous research demonstrating that the stress of food limitation can induce increased outcrossing propensity in C. elegans. Furthermore, our results expand on previous work by showing that food limitation can still increase outcrossing propensity even when it is not encountered until late development, and this can occur independently of the developmental and gene expression changes associated with dauer. Caenorhabditis elegans increase their propensity to outcross in response to food limitation encountered during late development.

Our objectives were to describe time intervals of EMS encounters for suspected stroke patients in North Carolina (NC) and evaluate differences in EMS time intervals by community socioeconomic status (SES) and rurality. This cross-sectional study used statewide data on EMS encounters of suspected stroke in NC in 2019. Eligible patients were adults requiring EMS transport to a hospital following a 9–1-1 call for stroke-like symptoms. Incident street addresses were geocoded to census tracts and linked to American Community Survey SES data and to rural-urban commuting area (RUCA) codes. Community SES was defined as high, medium, or low based on tertiles of an SES index. Urban, suburban, and rural tracts were defined by RUCA codes 1, 2–6, and 7–10, respectively. Multivariable quantile regression was used to estimate how the median and 90th percentile of EMS time intervals varied by community SES and rurality, adjusting for each other; patient age, gender, and race/ethnicity; and incident characteristics. We identified 17,117 eligible EMS encounters of suspected stroke from 2028 census tracts. The population was 65% 65+ years old; 55% female; and 69% Non-Hispanic White. Median response, scene, and transport times were 8 (interquartile range, IQR 6–11) min, 16 (IQR 12–20) min, and 14 (IQR 9–22) minutes, respectively. In quantile regression adjusted for patient demographics, minimal differences were observed for median response and scene times by community SES and rurality. The largest median differences were observed for transport times in rural (6.7 min, 95% CI 5.8, 7.6) and suburban (4.7 min, 95% CI 4.2, 5.1) tracts compared to urban tracts. Adjusted rural-urban differences in 90th percentile transport times were substantially greater (16.0 min, 95% CI 14.5, 17.5). Low SES was modesty associated with shorter median (−3.3 min, 95% CI −3.8, −2.9) and 90th percentile (−3.0 min, 95% CI −4.0, −2.0) transport times compared to high SES tracts. While community-level factors were not strongly associated with EMS response and scene times for stroke, transport times were significantly longer rural tracts and modestly shorter in low SES tracts, accounting for patient demographics. Further research is needed on the role of community socioeconomic deprivation and rurality in contributing to delays in prehospital stroke care.

Background/Objectives: Voice artificial intelligence (AI) technology is becoming increasingly common. Recent work indicates that middle-aged to older adults are less able to identify modern AI speech compared to younger adults, but the underlying causes are unclear. Methods: The current study with younger and middle-aged to older adults investigated factors that could explain the age-related reduction in AI speech identification. Experiment 1 investigated whether high-frequency information in speech—to which middle-aged to older adults often have less access due sensitivity loss at high frequencies—contributes to age-group differences. Experiment 2 investigated whether an age-related reduction in the ability to process prosodic information in speech predicts the reduction in AI speech identification. Results: Results for Experiment 1 show that middle-aged to older adults are less able to identify AI speech for both full-bandwidth speech and speech for which information above 4 kHz is removed, making the contribution of high-frequency hearing loss unlikely. Experiment 2 shows that the ability to identify AI speech is greater in individuals who also show a greater ability to identify emotions from prosodic speech information, after accounting for hearing function and self-rated experience with voice-AI systems. Conclusions: The current results suggest that the ability to identify AI speech is related to the accurate processing of prosodic information.

Given the cost of sex, outcrossing populations should be susceptible to invasion and replacement by self-fertilization or parthenogenesis. However, biparental sex is common in nature, suggesting that cross-fertilization has substantial short-term benefits. The Red Queen hypothesis (RQH) suggests that coevolution with parasites can generate persistent selection favoring both recombination and outcrossing in host populations. We tested the prediction that coevolving parasites can constrain the spread of self-fertilization relative to outcrossing. We introduced wild-type Caenorhabditis elegans hermaphrodites, capable of both self-fertilization, and outcrossing, into C. elegans populations that were fixed for a mutant allele conferring obligate outcrossing. Replicate C. elegans populations were exposed to the parasite Serratia marcescens for 33 generations under three treatments: control (avirulent) parasite treatment, a fixed (nonevolving) parasite treatment, and a copassaged (potentially coevolving) parasite treatment. Self-fertilization rapidly invaded C. elegans host populations in the control and the fixed-parasite treatments, but remained rare throughout the entire experiment in the copassaged treatment. Further, the frequency of the wild-type allele (which permits selfing) was strongly positively correlated with the frequency of self-fertilization across host populations at the end of the experiment. Hence, consistent with the RQH, coevolving parasites can limit the spread of self-fertilization in outcrossing populations.

Prevention of nosocomial infection, especially with MRSA, is a high priority. In this trial involving 74 ICUs at 43 hospitals, universal decolonization with the use of chlorhexidine and mupirocin was associated with a decrease in all-cause bloodstream infections. Health care–associated infection is a leading cause of preventable illness and death and often results from colonizing bacteria that overcome body defenses. 1 – 5 Among the pathogens causing health care–associated infection, methicillin-resistant Staphylococcus aureus (MRSA) has been given priority as a target of reduction efforts because of its virulence and disease spectrum, multidrug-resistant profile, and increasing prevalence in health care settings, particularly among patients in the intensive care unit (ICU). Hospitals commonly screen patients in the ICU for nasal carriage of MRSA and use contact precautions with carriers. 2 – 6 Nine states mandate such screening. 7 Decolonization has been used to reduce transmission . . .

Pupillometry is the most used objective tool to assess listening effort but has several disadvantages. The current study explores a new, objective way to assess listening effort through eye movements. Building on cognitive and neurophysiological work, we examine the hypothesis that eye movements decrease when speech listening becomes challenging. In three experiments with human participants from both sexes, we demonstrate, consistent with this hypothesis, that fixation duration increases and spatial gaze dispersion decreases with increasing speech masking. Eye movements decreased during effortful speech listening for different visual scenes (free viewing; object tracking) and speech materials (simple sentences; naturalistic stories). In contrast, pupillometry was insensitive to speech masking during story listening, highlighting the challenges with pupillometric measures for the assessments of listening effort in naturalistic speech-listening paradigms. Our results reveal a critical link between eye movements and cognitive load, and provide the foundation for a novel measure of listening effort applicable in a wide range of contexts.Competing Interest StatementThe authors have declared no competing interest.

Within-situation disengagement – the mental withdrawal during conversations in acoustically challenging environments – is a common experience of older people with hearing difficulties. Yet, most research on the neural mechanisms of attentional disengagement from speech listening has focused on the distraction by one competing speaker, whereas within-situation disengagement is often characterized by distraction towards external visual stimuli or internal thoughts and occurs in situations with ambient, multi-talker background masking. Across three electroencephalography (EEG) experiments, the current study examined how disengagement due to external and internal distractions affect the neural tracking of speech masked by different levels of multi-talker babble (speech in quiet, +6 dB, and −3 dB SNR). We observed early (<200 ms), enhanced neural responses to the speech envelope for speech masked by background babble compared to speech in quiet (Experiments 1-3), suggesting stochastic facilitation. Importantly, neural tracking of the speech envelope was reduced when individuals were distracted by a visual-stimulus stream (Experiment 2) and by internal thought and imagination (Experiment 3). There were some indices suggesting the greatest disengagement-related decline in neural speech tracking occurs for the most difficult speech-masking condition, but this was not consistent across all measures. The current data show that disengagement due to external and internal distractions yield decreases in neural speech tracking, potentially suggesting a common neural pathway through which gain is downregulated in auditory cortex. These results indicate that disengagement from listening can be identified through non-invasive neural measures. Many older adults with hearing difficulties mentally “tune out” during conversations in noisy environments, yet the neural mechanisms underlying this within-situation disengagement remain poorly understood. Across three electroencephalography experiments, we examined how external (visual) and internal (thought-based) distractions influence neural tracking of speech masked by multi-talker babble. We observed that attentional disengagement – whether induced by external stimuli or internal thoughts – reduced the brain’s tracking of the speech envelope. These findings demonstrate that listening disengagement can be objectively identified through neural measures and suggest a shared neural pathway through which both external and internal distractions down-regulate auditory gain, providing new insight into attentional control in challenging listening conditions.

To extend the assessment of listening effort beyond a sound booth, we validated mobile eye-tracking glasses (Pupil Labs Neon) by comparing them to a stationary system (Eyelink DUO) in a controlled environment. We recorded eye movements, pupil size, and head movements from 26 young adults during a speech-in-noise task. When listening conditions became challenging, we observed reduced gaze dispersion and increased pupil sizes of similar magnitude from both devices, in addition to reduced head movements recorded solely by the mobile device. These findings suggest that mobile eye-trackers reliably capture listening effort, paving the path towards assessments in daily settings.