bluuebunny/crossref_metadata_2025 huggingface dataset:
Improved hepatoblast differentiation of human pluripotent stem cells by coffee bean derived graphene quantum dots
Authors: Kang Hyun Kyoung , Kim Dong Jin , Kim Min Soo , Kim Da-Hyun , Lee Jin Young , Sung Eun-Ah , Sarsenova Madina , Chae Park Seong , Hong Byung Hee , Kang Kyung-Sun
Published: May 2022

Graphene quantum dots (GQDs) have been found to promote the efficient differentiation of stem cells into a variety of cell types. However, their bioactivity and signaling mechanisms in the hepatic lineage have not been fully investigated. Here, we report that the hepatoblast (HB) differentiation rate can be promoted by using Ca2+-rich coffee bean (CB)-derived GQDs, where the incorporated calcium ions activate the signaling of insulin-like growth factor 1 receptor (IGF1R)-protein kinase B (AKT). We also found that the human pluripotent stem cell (hPSC)-derived HBs from the CB-GQD treatment tend to upregulate the maturation into hepatocyte-like cells and downregulate the differentiation towards cholangiocytes, thereby successfully obtaining a large number of functional hepatocyte-like cells. Moreover, the activation of IGF1R from the CB-GQD treatment enhances the HB differentiation efficiency regardless of growth factors, implying that chelated calcium may play a key role in activating IGF1R. Our findings suggest that CB-GQDs with independent bioactivity can be widely used in place of IGF1 and represent a cost-effective growth factor as well as a potential differentiation factor.
A frequency selective surface loaded two-layer composite for tunable microwave absorption
Authors: Zhao Yiming , Wang Qichao , Sun Yungang , Xuan Shanyong , Li Minghang
Published: May 2022

To obtain tunable microwave absorption, a strategy of constructing a frequency selective surface (FSS) on a two-layer composite is proposed. The designed FSS loaded two-layer composite is composed of a FSS constructed by evenly spaced circular copper sheet, an impedance matching layer (SiO2 fiber reinforced epoxy resin (EP) composite, SiO2f/EP) and a lossy layer. Both simulation and experiments indicate that the SiO2f/EP layer serves as a good impedance matching layer with increased microwave absorption efficiency. By analyzing the distributions of electric field, magnetic field as well as the power loss, the strong resonance should be attributed to the enhanced incident microwave caused by FSS.
Hydrogen storage in complex hydrides: past activities and new trends
Authors: Dematteis Erika Michela , Amdisen Mads B , Autrey Tom , Barale Jussara , Bowden Mark E , Buckley Craig E , Cho Young Whan , Deledda Stefano , Dornheim Martin , de Jongh Petra , Grinderslev Jakob B , Gizer Gökhan , Gulino Valerio , Hauback Bjørn C , Heere Michael , Heo Tae Wook , Humphries Terry D , Jensen Torben R , Kang Shin Young , Lee Young-Su , Li Hai-Wen , Li Sichi , Møller Kasper T , Ngene Peter , Orimo Shin-ichi , Paskevicius Mark , Polanski Marek , Takagi Shigeyuki , Wan Liwen , Wood Brandon C , Hirscher Michael , Baricco Marcello
Published: May 2022

Intense literature and research efforts have focussed on the exploration of complex hydrides for energy storage applications over the past decades. A focus was dedicated to the determination of their thermodynamic and hydrogen storage properties, due to their high gravimetric and volumetric hydrogen storage capacities, but their application has been limited because of harsh working conditions for reversible hydrogen release and uptake. The present review aims at appraising the recent advances on different complex hydride systems, coming from the proficient collaborative activities in the past years from the research groups led by the experts of the Task 40 ‘Energy Storage and Conversion Based on Hydrogen’ of the Hydrogen Technology Collaboration Programme of the International Energy Agency. An overview of materials design, synthesis, tailoring and modelling approaches, hydrogen release and uptake mechanisms and thermodynamic aspects are reviewed to define new trends and suggest new possible applications for these highly tuneable materials.
Uniform inference in high-dimensional Gaussian graphical models
Authors: Klaassen S , Kueck J , Spindler M , Chernozhukov V
Published: May 2022

Graphical models have become a popular tool for representing dependencies within large sets of variables and are crucial for representing causal structures. We provide results for uniform inference on high-dimensional graphical models, in which the number of target parameters $d$ is potentially much larger than the sample size, under approximate sparsity. Our results highlight how graphical models can be estimated and recovered using modern machine learning methods in high-dimensional complex settings. To construct simultaneous confidence regions on many target parameters, it is crucial to have sufficiently fast estimation rates of the nuisance functions. In this context, we establish uniform estimation rates and sparsity guarantees for the square-root lasso estimator in a random design under approximate sparsity conditions. These might be of independent interest for related problems in high dimensions. We also demonstrate in a comprehensive simulation study that our procedure has good small sample properties in comparison to existing methods, and we present two empirical applications.
0013 Psychomotor Vigilance Test Performance Declines Related to Illness Severity, not Sleep
Authors: Doty Tracy , Mantua Janna , Gutierrez Ramiro , Alcala Ashley , Testa Kayla , Talaat Kawsar , Chaudhury Sidhartha , Isidean Sandra , Porter Chad
Published: May 2022

Introduction

While the Psychomotor Vigilance Test (PVT) has been used extensively to track vigilance degradation following sleep loss, there is evidence that it may also track vigilance degradation related to illness. However, it is unclear how much performance decline is driven by sleep loss related to an illness or the illness itself independent of sleep loss. Here we assessed how sleep and acute infectious diarrhea impact vigilance performance in a controlled human infection model (CHIM) with enterotoxigenic Escherichia coli (ETEC).

Methods

During a CHIM assessing the efficacy of an immunoprophylactic targeting ETEC, we measured sleep via actigraphy over an 8-day inpatient period. A 10-minute PVT was also administered up to three times each day in the morning, afternoon, and evening. Participants ingested an oral immunoprophylaxis 3 times/day on days -2 and -1, and ingested ETEC on day 0. Participants were categorized as to whether or not they experienced the primary endpoint of moderate-severe diarrhea (MSD).

Results

Among 56 participants (aged 34.7±8.5 years, 64% male), 54% reached the primary endpoint of moderate-severe diarrhea following ETEC infection. Total sleep times across the study did not differ between those with and without MSD. While PVT minor lapses (i.e., not responding within 500 milliseconds) did increase following ETEC infection for all subjects as revealed by a mixed linear model [effect of day: f(7,657)=3.35, p=0.002], there was also a significant main effect of group [f(1,657)=5.85, p=0.016], where those participants who experienced MSD following ETEC infection had more minor lapses across the study than those who did not experience MSD (6.28±0.43 vs 4.88±0.38).

Conclusion

While the negative impact of sleep loss on performance has been well demonstrated, these are the first data to suggest that illness severity[KT1] , independent of sleep loss, also negatively impacts performance. In operational populations such as the military, special care should be taken to prevent illness and remove ill operators from the field, just as this care should be taken to prevent sleep loss and remove sleepy operators. By preventing and monitoring sleep loss and illness, these operations can avoid potentially costly performance errors.

Support (If Any)

The clinical trial from which these data were obtained was funded by the Congressionally Directed Medical Research Program through the Joint Warfighter Medical Research Program under Award No. W81XWH-15-C-0083 to the Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. The U.S. Army Medical Research Acquisition Activity was the awarding and administering acquisition office. The study was also funded by a Collaborative Research and Development Agreement with PATH Enteric Vaccine Solutions (NCRADA-NMRC-15-9589), as well as by the Military Operational Medicine Research Program (MOMRP).
0022 Improving predicted effectiveness of shiftworkers in watchfloors
Authors: Matsangas Panagiotis , Shattuck Nita , Sheehan Sarah , Dotson Elizabeth
Published: May 2022

Introduction

In support of 24/7 hour operations around the globe, Navy and Marine Corps shore-based watchfloors provide information, intelligence, and technical support to the warfighter. Personnel working on these watchfloors are challenged to obtain consistent sleep due to shift working. The study objectives were to model the predicted effectiveness (PE) of the current watch schedule and recommend a new schedule to improve sleep, safety, and performance.

Methods

In a 3-week longitudinal, naturalistic study, we assessed the work/rest patterns and well-being of watchstanders while on their typical watch schedule. Participants (N=11, age:19-33yrs) completed an online sleep/activity log for the study period. Standardized tools (Pittsburgh Sleep Quality Index--PSQI, Epworth Sleepiness Scale--ESS, Insomnia Severity Index--ISI, Profile of Mood States--POMS) were completed pre/post-study. Based on study findings combined with information gathered from the command leadership, we designed an improved watch schedule. The Fatigue Avoidance Scheduling Tool (version 3.3.01T) employing the Sleep, Activity, Fatigue, and Task Effectiveness model (SAFTE/FAST) was used to model PE in the legacy and newly improved watch schedules.

Results

The median daily reported sleep duration was 6hrs (range: 5-8.5hrs). Nine participants (82%) were classified as poor sleepers and six (55%) had elevated daytime sleepiness. Four (36%) participants had moderately severe/severe insomnia symptoms. In terms of mood, 10 (91%) participants had a lower vigor-activity score than the adult norms, whereas eight (73%) scored higher than the adult norms for fatigue. The mid-shift watches had low PE that dropped steeply throughout the shift. The timing of low PE coincided with the period in which personnel was briefing leadership and/or commuting from work.

Conclusion

Based on our findings, we recommended a schedule that enables more regular sleep patterns. Compared to the legacy schedule, the new schedule increased both the number of week days and weekend days off, with 2-3 full weekends off per month. Also, PE was improved and the trough in PE did not occur during the commute. Lastly, we recommended that the new watch schedule should rotate less frequently with longer times on an assigned shift.

Support (If Any)

This work was supported in part by the Naval Medical Research Center's Naval Advanced Medical Development Program.
0041 Chronotype predicts health outcomes but not sleep duration in early pandemic sleep schedules
Authors: Zendels Philip , Gaultney Jane
Published: May 2022

Introduction

Lockdowns associated with the COVID-19 pandemic allowed for individuals to change their schedules. Chronicity is a trait-like preference for individuals’ times of the day for activity and feeling best. As a result of the lockdowns, some individuals were able to adjust their schedule to reflect personal chronotype needs. This study examined whether chronotype predicted sleep duration and health outcomes.

Methods

A sample of 304 participants were recruited through Amazon’s Mechanical Turk service to fill out surveys relating to personality and health. Individuals responded with their normal bedtime and waketime for weeknights and weekends and filled out the Morningness-Eveningness Questionnaire (MEQ; Horne & Östberg, 1976). Self-reported health outcomes were measured via 9 items on the Patient Reported Outcomes Measurement Information System (PROMIS; Cella et al., 2010). Data were cleaned and analyzed via linear regressions in SPSS with age, sex, race, ethnicity and education as covariates.

Results

Participants reported an average of 8.52 hours of sleep (SD = 1.97 hours). 35.3% of the sample scored strong- or moderately morning-type, 54.7% were neither morning-nor evening-type and 10% scored as evening- or strong-evening types (M = 54.95; SD = 9.42). Results from the PROMIS ranged from 18 to 45 (M = 32.24, SD = 5.49). The model predicting sleep duration (R2 = .06, p = .03) produced a significant effect of ethnicity but not chronicity. Hispanic or Latino ethnicity reported shorter sleep durations relative to those who self-identified as non-Hispanic or Latino. The model predicting PROMIS (general health) scores (R2 = .14, p < .001) produced effects of education (b = .46, p = .04) and Morningness (b = .21, p < .001). People with higher educational levels and those with morning preferences reported better health.

Conclusion

Morningness is often associated with better self-regulation, lower risky behaviors, better physical and mental health and better sleep. During the early stages of the COVID-19 pandemic, lockdowns allowed many individuals more scheduling flexibility. As a result, sleep duration differences across chronotypes were absent, though health differences remained. Future research should continue to explore differences in sleep schedules in predicting health outcomes.

Support (If Any)

Charlie Reeve and the Misfits lab at UNCC.
0060 Sleep disparities by race/ethnicity during pregnancy: an Environmental influences on Child Health Outcomes (ECHO) study
Authors: Lucchini Maristella , O'Brien Louise , Kahn Linda , Brennan Patricia , Baron Kelly , Knapp Emily , Lugo Claudia , Shuffrey Lauren , Dunietz Galit , Zhu Yeyi , Alcantara Carmela , Fifer William , Elliott Amy
Published: May 2022

Introduction

Poor sleep during pregnancy is common and associated with increased risk of adverse perinatal outcomes. Racial/ethnic minoritized groups in the United States experience worse sleep than non-Hispanic Whites (nHW), likely due to downstream effects of systemic and structural discrimination. Nonetheless, the extent of sleep disparities in the perinatal period remains understudied. In this analysis we estimated the prevalence of subjective measures of sleep in a multi-racial/ethnic pregnant population from the Environmental influences on Child Health Outcomes (ECHO) program.

Methods

Participants self-reported their race and ethnicity and were grouped into four categories: 1)nHW, 2)non-Hispanic Black/African American (nHB/AA), 3)Hispanic, 4)non-Hispanic Asian (nHA). Our analysis examined trimester-specific nocturnal sleep duration, sleep quality, and sleep disturbances (derived from the Pittsburgh Sleep Quality Index and the ECHO maternal sleep health questionnaire) by race/ethnicity. A total of 1119,2409 and 1284 participants in the first (T1), second (T2) and third trimesters (T3) reported on sleep duration. 1107,1742 and 783 participants in T1,T2 and T3 reported on sleep quality. 1112,1758, and 787 participants in T1,T2 and T3 reported on sleep disturbances Linear or multinomial regression were used to estimate associations between race/ethnicity and each sleep domain by trimester, controlling for body mass index (BMI) and age. We repeated analyses within education strata (high school degree, GED/equivalent; some college and above)

Results

nHB/AA participants reported shorter sleep duration (T2: β=-0.55 [-0.80,-0.31]: T3: β=-0.65 [-0.99,-0.31]), and more sleep disturbances (T2:β=1.92 [1.09,2.75]; T3:β=1.41 [0.09,2.74]) compared to nHW. Hispanic participants reported longer duration compared to nHW (T1: β=0.22 [0.00004, 0.44];T2: β=0.61 [0.47,0.76];T3: β=0.46 [0.22,0.70]), better sleep quality (Compare to Very good quality OR for Fairly good T1: OR=0.48 [0.32,0.73], T2: OR=0.36 [0.26,0.48], T3: OR=0.31 [0.18,0.52]; Fairly bad T1:OR=0.27 [0.16,0.44], T2:OR=0.46 [0.31,0.67], T3: OR=0.31[0.17,0.55]), and fewer sleep disturbances (T2 β=-0.5 [-1.0,-0.12]; T3 β=-1.21 [-2.07,-0.35]). Differences persisted within the subsample of high SES women.

Conclusion

These findings highlight racial/ethnic disparities across multiple domains of sleep health during pregnancy. Given the stark racial/ethnic disparities in perinatal outcomes and their associations with sleep health, further research is warranted to investigate the determinants of these disparities, such as downstream effects of systemic and structural discrimination

Support (If Any)
0067 Sleep Disparities and the Academic Achievement Gap in 1.9 Million College Students
Authors: Nickel Allison , Scullin Michael
Published: May 2022

Introduction

Adults from under-represented minority groups (URM) disproportionately experience sleep disturbances. Sleep disparities can be prevalent in academic settings, however, it is still unknown whether sleep disparities directly contribute to other disadvantages in URM students, such as the academic achievement gap. Using a national database of college students collected over 20 years, we investigated whether poor sleep quality mediated the relationship between race/ethnicity and grade point average (GPA).

Methods

We conducted secondary analyses on American College Health Association – National College Health Assessment survey data (ACHA-NCHA). The ACHA-NCHA I, II, IIb, IIc, and III surveys were conducted between 2000 and 2020, and included approximately 1,900,000 participants. We analyzed responses to questions regarding race/ethnicity, socioeconomic status, academic achievement (GPA), daytime sleepiness, and sleep health. Non-URM students were those identifying as non-Hispanic White or Asian whereas URM students included all other racial/ethnic identifications. We calculated a sleep-problems composite score by transforming each sleep item response into a z-score and averaging across all items.

Results

Sleep disparities were evident amongst the college students; relative to non-URM students, URM students reported fewer days per week that they felt rested (95% CIs: 3.884–3.895 vs. 4.155–4.161) and worse sleep-problem composite scores (95% CIs: .0453–.0496 vs. -.0226 – -.0199). In addition, there was significant evidence for an academic achievement gap, such that URM students reported significantly lower GPAs than non-URM students (95% CIs: 3.162–3.166 vs. 3.344–3.346). Feeling rested and sleep problem composite scores partially mediated the relationship between race/ethnicity and academic achievement (ps < .001), explaining 4.1% and 5.1% of the variance, respectively. These results were lower in magnitude than the contribution of socioeconomic status (25.3% of the mediation variance); however, sleep problems and feeling rested continued to explain significant variance even when controlling for socioeconomic status.

Conclusion

Sleep disparities contribute to academic achievement gaps experienced by URM students. The current findings indicate that university-wide sleep health programs may help to remove an unnecessary barrier to academic achievement, particularly if such programs incorporate behavioral change theory and address system-level financial, sociocultural, and environmental barriers to sleep quality.

Support (If Any)

National Science Foundation (1920730 and 1943323)
0072 A Mexican Spanish Version of the Insomnia Severity Index
Authors: Granados Karla , Begay Tommy , Valencia Dora , Delgadillo Marcos , Ghani Sadia , Molina Patricia , Alfonso-Miller Pamela , Fernandez-Mendoza Julio , Wills Chloe , Grandner Michael
Published: May 2022

Introduction

Data were collected for the Insomnia Severity Index (ISI). To ensure the validity of study subject responses, the ISI was translated into Mexican Spanish by a bilingual research study team, based on a previous Spanish translation. It was then administered to study subjects in their preferred language.

Methods

Data were collected from a sample of N=100 individuals of Mexican Descent in Nogales, Arizona, at the US-Mexico border. The Insomnia Severity Index (ISI) is a 7-item scale that quantifies the degree to which an individual experiences insomnia symptoms. A Spanish translation already exists, but this had not been previously localized to Mexican Spanish. To localize the measure, the following procedure was followed: (1) a bilingual community member edited the translation; (2) a certified medical translator edited the revised items; (3) a focus group of N=5 bilingual community members made contextual edits to the new measure; (4) a back-translation was performed; (5) an additional bilingual focus group examined the final version for compatibility; and (6) the medical translator certified the accuracy of the final version. As a result of this process, text edits to items 4 and 6 were made to accomplish the localization (the other items remained unchanged). T-tests examined differences between those who completed the measure in Mexican Spanish vs English.

Results

Of the N=100 survey respondents, N=42 completed the ISI in Spanish. Those who completed the ISI in Spanish reported significantly lower overall scores (8.2 vs 9.8, p=0.048). No significant differences were seen for individual items regarding early morning awakenings (p=0.13), satisfaction (p=0.71), interference with daily functioning (p=0.29), whether sleep problems are noticeable (p=0.06), and worry/distress about sleep (p=0.14). However, those completing the measure in Spanish reported lower scores on items regarding difficulty falling asleep (p=0.03) and staying asleep (p=0.001).

Conclusion

When adapting the ISI to a Spanish-speaking population at the US-Mexico border, modifications were made to the existing Spanish translation to improve linguistic and cultural appropriateness.

Support (If Any)
0094 Oscillatory Theta-Band Activity as a Sleep Stage Independent Measure of REM-like Activity throughout Sleep
Authors: Vattikuti Shashaank , Balkin Thomas , Braun Allen , Riedy Samantha , Doty Tracy , Hughes John
Published: May 2022

Introduction

The importance of human cortical theta-band power during REM is suggested by its association with aspects of emotional processing. Currently, this is measured first by visual-inspection of polysomnography to define REM-sleep (scored-REM) and then summing the total theta power within. However, activity attributed to scored-REM has been hypothesized to occur during some scored-NREM (“covert REM”) and total theta conflates different theta-band sources. Oscillatory theta-band activity (OTA) in the hippocampus and associated regions is the hallmark of REM-like sleep in invasive animal studies. We posit that an EEG assessment specifically targeting all-night OTA is a more accurate biomarker of theta-dependent REM functions than current methods. As a first step towards testing this hypothesis, we developed a sleep stage independent approach to isolate REM-like OTA from scalp-EEG. For validation, we compared this measure to conventional-staging and high-frequency activity.

Methods

Our method uses Irregular-Resampling Auto-Spectral Analysis to remove the aperiodic spectrum (a major source of theta-band power), followed by low-band power normalization to derive the relative oscillatory-theta activity (OTA). Covert REM-containing epochs were calculated based on OTA exceeding a threshold. We combined data from two in-laboratory studies resulting in a sample size of 42 healthy young adult subjects. Analyses used non-sleep restricted overnight EEG recordings from a frontal channel.

Results

A clear oscillatory-theta peak was observed after processing. Using all sleep stages, we found separation of OTA from total theta-band power evidenced by conventional staging (OTA: scored-REM>scored-NREM, p=0.003 vs total theta: scored-REM<scored-NREM, p<0.001) and correlation with beta-band activity (OTA: r=0.2, p<0.001 vs total theta: p=0.4). Supporting “covert REM”, OTA was present during scored-NREM (p<0.001). On average during a single sleep episode, covert REM was found in 28% of scored- NREM epochs (range=2-85%).

Conclusion

We developed a novel automated method for measuring REM-like oscillatory-theta activity, independent of conventional sleep staging methods. This method was used to measure REM-like activity across all sleep stages and, as reported in a companion abstract, test the hypothesis that this constitutes a better predictor of REM-dependent behavioral effects than current conventions.

Support (If Any)

This effort was fully supported by the Department of Defense Military Operational Medicine Research Program (MOMRP).
0109 Working Memory across Sleep and the Menstrual Cycle in Young and Midlife Women
Authors: Shuster Alessandra , Zhang Jing , Sattari Negin , Simon Katharine , Alzueta Elisabet , Dulai Teji , de Zambotti Massimiliano , Baker Fiona , Mednick Sara
Published: May 2022

Introduction

The menses phase of a woman’s menstrual cycle, compared to other phases, is more likely to be associated with poorer sleep quality and alterations in cognitive performance, specifically impaired working memory. However, the relationship among these factors has been poorly investigated, and how age impacts these relationships is currently unknown. The present study examines the effect of menstrual cycle phase and sleep on working memory performance in young and midlife women.

Methods

Fifty-five young and midlife women (n = 29, 18 – 35 years; n = 26, 45 – 56 years) completed four remote assessments at different phases of their menstrual cycle: menses, late-follicular, mid-luteal, and late-luteal, defined based on days of menses and ovulation. On each visit, participants completed the operation span (OSPAN) working memory task in the evening and were re-tested for sleep-related performance change in the morning. In addition, participants wore an Oura ring, a multi-sensor wearable sleep tracker, throughout the night. Mixed linear regression, correlation models, and paired t-tests were used to determine the relationship between menstrual phase, sleep, and OSPAN outcomes in both groups.

Results

In midlife women only, OSPAN performance improvement significantly changed across menstrual cycle phases (p < .05). The greatest post-sleep improvement in OSPAN performance was detected during the mid-luteal and late-follicular phases of the cycle, while lower performance gains were detected during menses and late-luteal phases. Post-hoc paired t-tests confirmed that post-sleep performance was significantly worst during menses compared to each of the other phases (p < .05). Additionally, during the mid-luteal phase, time spent in deep sleep positively correlated with post-sleep performance in midlife women (r = .55, p < .05). No significant effects were detected in young women.

Conclusion

These findings suggest a complex interaction between sleep, menstrual cycle phase, and cognitive performance in midlife women. Our data suggest that deep sleep may mediate post-sleep performance during specific cycle phases. Reasons why these results are not evident in younger women are yet to be determined.

Support (If Any)

Supported by: RF1AG061355 (Baker/Mednick)
0119 Effects of Total Sleep Deprivation on Performance on a Continuous Performance Matching Task
Authors: Hudson Amanda , Hinson John , Whitney Paul , Lawrence-Sidebottom Darian , Van Dongen Hans , Honn Kimberly
Published: May 2022

Introduction

Tasks requiring individuals to identify specific stimuli may create response/non-response conflict, which may impair performance depending on stimulus feature overlap. Whether sleep deprivation interacts with such impairment is unknown. We investigated the effects of total sleep deprivation (TSD) on stimulus identification in a continuous performance matching task (CPMT).

Methods

N=85 adults (ages 21–40; 50f) completed a 4-day laboratory study with 10h baseline sleep (22:00–08:00), a 38h acute TSD or 10h sleep opportunity (control condition), and 10h recovery sleep. The ~6min CPMT was administered every 2–4h during wakefulness. Participants completed 300 trials where a 3-digit number was flashed on the screen for 100ms. They were instructed to respond (mouse-click) within 900ms, but only if the number was the same as the preceding number (i.e., a repeat); for all other trials a response was to be withheld. The 5 daytime testing sessions (09:00–21:00) at baseline (day 2) and after TSD/control (day 3) were used for analysis. Trials were classified based on number of digits matching the preceding trial (stimulus feature overlap): none (180 trials), one (30 trials), two (near-repeat; 30 trials), or all (repeat; 60 trials). Hit and false alarm (FA) rates were analyzed with mixed-effects ANOVA for day, condition, trial type, and their interactions. Mean response time (MRT) was analyzed equivalently for repeat trials only.

Results

Hit rate declined from day 2 to day 3 in the TSD group (F[1,83]=0.15, p<0.001), but not the control group (F[1,83]=0.018, p=0.335). Though FA rate was low overall (<0.06), FA frequency was higher on trials with greater stimulus feature overlap. FA rate increased on day 3 for the TSD group (all p<0.004), especially for near-repeats (F[1,415]=-0.014, p<0.001). Changes in MRT were statistically significant, but negligible (<20ms).

Conclusion

Our results suggest that greater stimulus feature overlap on the CPMT was associated with greater costs required to resolve conflict. Sleep deprivation exacerbated these costs. Interpretation is limited however, because a response was not required for non-repeat trials. Implementing a two-alternative forced choice version of the task in future TSD studies would address this limitation.

Support (If Any)

PRMRP W81XWH-16-1-0319 and W81XWH-20-1-0442
0142 From Shore to Shipboard: Severity of Sleep Disturbance and Sleep-Related Impairment of Sailors Aboard US Navy Warships
Authors: Kubala Andrew , Jameson Jason , Roma Peter , Russell Dale , Markwald Rachel
Published: May 2022

Introduction

Sleep quality is known to be negatively impacted during military operations at sea. Yet, there are limited naval studies that explore measures of sleep disturbances and sleep-related impairment, especially in relation to different warship classes. This analysis compares sleep disturbances and sleep-related impairment across two warship classes during similar at-sea periods.

Methods

432 sailors (77.6% male; 27.4±7.1 years) participated in a training evolution aboard either a destroyer (DDG; n=194) or an amphibious class ship (LHD; n=238). Participants completed a 7-day recall questionnaire assessing their sleep and health behavior prior to getting underway (baseline) and 1–2 days prior to completing a 2-week underway (underway). Primary outcomes included the PROMIS Sleep-Related Impairment scale (P-SRI) and the PROMIS Sleep Disturbance scale (P-SD). While underway, participants self-reported their diet quality, daily caffeine and nicotine intake, overall health, and daily time spent exercising; these factors were included as covariates in all analyses. Linear mixed effects models were used to explore the within-subject effect of baseline vs. underway sleep and a between-subjects effect by ship class (i.e., DDG or LHD). Independent t tests and chi-square tests were used to compare ship groups at baseline.

Results

Participants within ship class had a similar age, time in military service, and sex (p≥.06). Across both ship classes, there were increases in severity of sleep-related daytime impairment and sleep disturbances between baseline and underway (P-SRI: B=5.2±0.6; P-SD: B=3.4±0.5; p<.001). Additionally, DDG participants had a significantly greater increase in sleep-related impairment between baseline and underway compared with their LHD-class counterparts (Group*Time interaction effect: B=4.3±0.9, p<.001; LHD: 54.5±0.6 [baseline] vs. 54.5±0.5 [underway], DDG: 54.9±0.6 [baseline] vs. 60.2±0.6 [underway]).

Conclusion

These results suggest sleep-related impairment and sleep disturbances are greater while underway compared with an in-port environment. Although preliminary, these results suggest that differential impacts on sleep-related impairment may occur across ship classes, even when undergoing similar underway events. Further research is needed to understand how insufficient sleep and its consequences change in shipboard environments and how these effects may vary between ship classes so as to better inform targeted naval-focused sleep health improvement strategies.

Support (If Any)

Military Operational Medicine Research Program under work unit no. N2010.
0154 Differences in Monocyte Activation between People with Treated HIV Infection With or Without OSA
Authors: Borker Priya , Macatangay Bernard , Patel Sanjay
Published: May 2022

Introduction

Obstructive sleep apnea (OSA) has been associated with low grade systemic inflammation and greater cardiovascular risk, but the specific pathways mediating these effects are unclear. Monocyte activation is implicated in the development of cardiovascular disease in people with treated HIV infection. We sought to evaluate the impact of OSA on monocyte activation in people living with human immunodeficiency virus (HIV) infection.

Methods

Ten HIV seropositive participants with undetectable (<50 copies/mL) HIV viremia and at least one year of antiretroviral therapy underwent home sleep apnea testing to evaluate for the presence (apnea-hypopnea index -AHI4% ≥15 events/hour) or absence (AHI4% <5 events/hour) of OSA. Mononuclear cells were extracted and analyzed by flow cytometry. The composition of monocyte subsets (classical, intermediate, patrolling) was assessed using surface markers. Intracellular tumor necrosis factor alpha (TNFα), interleukin 1β (IL-1β), and interleukin 6 (IL-6) levels were measured by median fluorescence intensity (MFI, unit: au) and log-transformed. Differences in monocyte subset composition and intracellular cytokine levels between those with and without OSA were analyzed by t-test.

Results

Participants had a mean ± SD age of 61 ± 4.7 years, were 50% female, 80% Black race and had well-constituted CD4+ counts (mean ± SD: 934 ± 283 cells/ml). The mean AHI4% among participants with OSA (n=4) was 21.8 ± 4.4 events/hour whereas controls (n=6) had an AHI4% of 2.4 ± 2.0 events/hour (p-value = 0.001). There was no difference in the proportion of classical monocytes between groups (mean ± SD 83.8% ± 11.5% in participants with OSA vs. 84.9% ± 7.5% in controls, p=0.86). Intracellular TNFα was greater in monocytes from participants with OSA vs. controls (log-transformed MFI 3.49±0.20 au vs. 3.00±0.35 au, p=0.03). Additionally, there was a trend toward greater intracellular concentrations of IL-1β (mean log-transformed MFI 3.24±0.15 au vs. 2.95±0.48 au, p=0.22) and IL-6 (log-transformed MFI 3.28±0.16 au vs. 2.91±0.64 au, p=0.23), in participants with OSA vs. controls.

Conclusion

Pro-inflammatory cytokine levels are greater in monocytes obtained from people with treated HIV infection with OSA compared to those without OSA. Our findings suggest OSA may exacerbate chronic inflammation and cardiovascular risk in chronic HIV infection.

Support (If Any)

HL082610 and American Thoracic Society ASPIRE Fellowship
0168 Subjective and Objective Markers of Sleepiness in Drivers
Authors: Thieux Marine , Guyon Aurore , Herbillon Vania , Merle Lydie , Lachaux Jean-Philippe , Plancoulaine Sabine , Seugnet Laurent , Franco Patricia
Published: May 2022

Introduction

Sleepiness is associated with a decrease in cognitive abilities with effects comparable to those of alcohol. It remains one of the main causes of fatal road accidents. Various tools are available to assess sleepiness subjectively and objectively, such as questionnaires and multiple sleep latency test. However, the former are subject to intra- and inter-individual variability, and the latter is only feasible in a sleep laboratory. The main objective of this study was to explore new potential markers (biological, neurocognitive) to assess sleepiness in drivers. In this perspective, the easy-to-use BLAST attention test allows the evaluation of micro-fluctuations in vigilance. In addition, salivary markers are good physiological markers, easily accessible and non-invasive to collect. Recent studies have suggested that salivary a-amylase and oxalate may be biomarkers of sleep pressure.

Methods

185 drivers (median age 44 years, 72% male, 15% obese) were included during a break at a highway service area, in the morning, while on the road for vacation. Questionnaires on sleepiness, sleep the day before departure, an attention test and two salivary samples (alpha-amylase and oxalate) were taken. Associations between subjective and objective measures of sleepiness, sleep characteristics and salivary concentrations were tested using regression models adjusted for confounding factors.

Results

The night before departure, 57% of drivers reduced their sleep time and more than ¼ slept 5 hours or less. The higher the number of miles to drive, the shorter the sleep time. 16% of the drivers complained of poor sleep quality and difficulty falling asleep. At the time of the test, 46% of the drivers felt drowsy. Poor sleep quality or difficulty falling asleep the night before departure was associated with increased sleepiness as assessed by the Stanford Sleepiness Scale and decreased attentional ability as assessed by the BLAST. No association between salivary samples and sleepiness was observed.

Conclusion

Sleep characteristics on the day before departure were associated with sleepiness and attentional performance. The Stanford Sleepiness Scale and the BLAST could be used by individual drivers in a self-evaluation context.

Support (If Any)

This study was funded by the Vinci Foundation.
0189 High Levels of Sleep Disturbance across Early Childhood Increases Cardiometabolic Disease Risk Index in Early Adolescence: Longitudinal Sleep Analysis Using the HOME Study
Authors: Duraccio Kara , Xu Yingying , Beebe Dean , Lanphear Bruce , Chen Aimin , Braun Joseph , Cecil Kim , Yolton Kimberly
Published: May 2022

Introduction

Sleep is a predictor of cardiometabolic disease (CMD) risk, and new evidence links early childhood sleep to later CMD risk. This study examines the impact of early childhood sleep duration, bedtime timing, and sleep disturbance on a CMD risk score in early adolescence.

Methods

Within the Health Outcomes and Measures of Environment (HOME) Study, a prospective pregnancy and birth cohort study, we assessed sleep patterns among 346 children using the Children’s Sleep Habits Questionnaire from ages 2 to 8 years. We calculated cardiometabolic risk scores ate age 12 for 183 of these children from visceral adiposity area, blood pressure, fasting serum triglyceride, high density lipoprotein, leptin, and adiponectin concentrations. We used a group-based semi-parametric mixture model to identify distinct trajectories in sleep duration, bedtime timing, and sleep disturbance for the entire sample. We then examined the associations between sleep trajectories and CMD risk score using general linear models for children with a CMD risk score, using both an unadjusted model (no covariates) and an adjusted model (adjusting for child pubertal stage, child sex, duration of breastfeeding, household income, and maternal education).

Results

Three sleep trajectories emerged for bedtime timing (late timing, medium timing, and early timing) and for sleep disturbance (high, medium, and low), and two for sleep duration (high and low). In the unadjusted model, we found significant differences in CMD risk scores by trajectories of sleep disturbance. Children in the ‘high’ trajectory had higher CMD risk scores (Least Square Mean=1.51; 95% CI: 0.39, 2.64) than those in the ‘low’ trajectory (Least Square Mean =-0.51; 95% CI: -1.16, 0.15; p=.002) and ‘medium’ trajectory (Least Square Mean=-0.15; 95% CI: -1.14, 0.85; p=.03). These findings only approached significance after adjusting for covariates. No significant differences in CMD risk were observed for bedtime timing or total sleep time trajectories in the unadjusted or adjusted models.

Conclusion

In this cohort, parent-reported sleep disturbance in early childhood was associated with more adverse cardiometabolic profiles in early adolescence. Our findings suggest that trials to reduce CMD risk via sleep interventions – which have been conducted in adolescents and adults – may be implemented too late.

Support (If Any)

National Institute of Environmental Health Sciences grants PO1 ES11261, R01 ES014575, R01 ES020349, R01 ES027224, R01 ES025214.
0203 Rise and shine! The efficacy of a multimodal environmental alarm system on mitigating the effects of sleep inertia
Authors: Campanella Carolina , Byun Kunjoon , Senerat Araliya , Li Linhao , Zhang Rongpeng , Aristizabal Sara , Porter Paige , Bauer Brent
Published: May 2022

Introduction

Sleep inertia is a temporary period of reduced alertness and impaired physical and cognitive performance that immediately follows waking. Sleep inertia can have devastating consequences necessitating an intervention to successfully mitigate symptoms. Previous work has demonstrated modest benefits for individual environmental interventions which manipulate either lighting, sound, or temperature. The current study sought to expand on previous work and measure the impact of a multimodal intervention that collectively manipulated light, sound, and ambient temperature on vigilance, mood, and sleepiness.

Methods

37 adults (M=27.13 years, 19 F) who self-reported taking longer than 30 minutes to wake up for 60% of their work week slept in the lab for four nights. They were woken up each morning with either a traditional alarm sound or the multimodal intervention (two control nights and two intervention nights, counterbalanced across participants). Feelings of sleep inertia were measured each morning through completion of the Psychomotor Vigilance Test and ratings of sleepiness and mood at five different time-points (5, 15, 30, 60, and 90 min after wake).

Results

While there was little impact of the intervention on all outcome measures, there were differential impacts depending on a person’s chronotype and the length of the lighting exposure during the intervention condition. Moderate evening-types who received a shorter lighting exposure (£15 min) demonstrated more vigilance lapses (p = 0.04) relative to the control condition whereas intermediate-types demonstrated better response speed (p < 0.005) and fewer lapses (p = 0.002). Conversely, moderate evening-types who experienced a longer light exposure (>15 min) during the intervention exhibited fewer false alarms over time (p = 0.03). Participants who received a longer light exposure also reported marginally lower negative affect the longer they were awake (p = 0.06).

Conclusion

Collectively, the results suggest that the length of the environmental intervention may play a role in mitigating feelings of sleep inertia, particularly for groups who may exhibit stronger feelings of sleep inertia including evening-types. Results may help inform the efficacy of “smart alarms” that activate based on entering light sleep. Future studies should measure this impact using additional measures of cognitive performance.

Support (If Any)
0206 Rest-Activity Rhythms are Associated with Sleep Characteristics and Cognitive Functions in People with Heart Failure Over 6 Months
Authors: Jeon Sangchoon , Conley Samantha , O'Connell Meghan , Yang Raymond , Redeker Nancy
Published: May 2022

Introduction

People with Heart failure (HF) often suffer from sleep deprivation and poor cognitive function. The purpose of this study was to examine the extent to which repeatedly measured rest-activity rhythms (RARs) measured with wrist actigraphy predict sleep characteristics and cognitive function in people with HF.

Methods

We measured insomnia severity (ISI), sleep quality (Pittsburgh sleep quality index: PSQI), sleepiness (Epworth sleepiness scale: ESS), psychomotor vigilance (Psychomotor vigilance test: PVT), and quality of life (Euroqol 5D) among people with HF patients who participated in a randomized controlled trial of cognitive behavioral therapy for insomnia vs. HF self-management education at baseline, 3-, and 6-months post-intervention. We performed cosinor analysis with 24-hour rest-activity counts obtained with 7 days of wrist actigraphy at each time point and calculated the circadian quotient, which represents the strength of RARs. We used the Generalized Linear Mixed Model with random intercepts to examine the association between the circadian quotient, sleep characteristics, cognitive function, and quality of life after adjusting for time-group interactions over 6 months. Statistical significance for standardized coefficients was accepted at 5% type I error.

Results

The analysis included 162 participants with HF and insomnia (Insomnia severity index >7) who completed actigraph monitoring for at least 7 days at baseline There was no significant change in the mean circadian quotient (Mean=0.78, SD=0.16) over 6 months. After adjusting for significant intervention effects, a greater circadian quotient was statistically associated with lower insomnia severity (-0.11±0.05), sleepiness (-0.12±0.05), sleep quality (-0.15±0.05), longer sleep duration (0.33±0.04) and better sleep efficiency (0.13±0.05). The circadian quotient was positively associated with cognitive function measured by fewer PVT lapses (-0.11±0.05) and quality of life (0.12±0.05).

Conclusion

In addition to the significant intervention effects for insomnia, HF patients may benefited from strengthening RAR to improve sleep characteristics, cognitive function, and quality of life. Further research to assess the contributions of RAR in people who received the intervention for insomnia and the HF self-education separately is recommended.

Support (If Any)

R01NR016191 and P20NR014126
0208 Daytime alertness quantification and modelling: results from a large observational study
Authors: Barr Shawn , Garcia-Molina Gary
Published: May 2022

Introduction

Subjective alertness variations throughout the day can be characterized using the two-process model (TPM) of sleep regulation, which combines sleep homeostasis and the circadian rhythm to derive a theoretical daytime alertness curve. The TPM has been adopted to model the effect of sleep deprivation on memory, circadian misalignment, temperature regulation, and brain function; however, despite its broad influence, evidence supporting the TPM-derived alertness comes largely from small-scale, controlled studies. Here, we show that a similar three-parameter alertness measure can scale to a large study sample under real-world conditions.

Methods

Subjective alertness was voluntarily rated on a scale from 1 to 10 by Sleep Number smart bed users (N=22 499) through the SleepIQ app. Three age groups (18–40, 41–65, and 66–90 years) were analyzed. A 3-parameter version of the TPM-derived alertness curve was fit to the self-rated alertness responses using nonlinear least-squares fitting.

Results

A total of 65 528 sleep sessions were gathered over 95 days and analyzed. Overall, subjective alertness followed a similar trend to that reported in published literature: mean hourly alertness increased in the morning, dipped slightly in the afternoon, increased during the evening, and dropped again during the night. In contrast to previous studies, mean alertness ratings only changed by approximately 1 unit from low to high, and a greater increase in alertness occurred from afternoon to evening. Age-group analyses found that youngest sleepers’ mean daily alertness was more stable throughout the day, and the amplitude of alertness variation decreased with age. These experimental results showed high agreement with model prediction (R2=0.96, P<0.001).

Conclusion

Overall, our results were similar to previous reports, with the exception of a small absolute change over the course of the day (about 1 unit) and an evening peak in alertness that was more pronounced in our data. These results show that the TPM-derived alertness can effectively predict daily alertness trends in a large sample under real-world conditions.

Support (If Any)

This study was funded by Sleep Number Corporation. Medical writing support, provided by Rachel C. Brown, PhD, from Oxford PharmaGenesis Inc., Newtown, PA, USA, was funded by Sleep Number Corporation.