Non-consecutive Nights Research Articles

Music cue during slow wave sleep improves visuospatial memory consolidation.

The active system consolidation theory assumes that sleep between encoding and retrieval promotes memory consolidation. In the present study, we cued new memories during slow-wave (SWS) or rapid eye movements (REM) sleep stages by presenting an instrumental music stimuli that had been previously presented during a learning session. In a within-subjects design, 18 participants slept for three nonconsecutive nights (cue during SWS, cue during REM, and no cue during control night) and were trained in a visuo-spatial memory task. The administration of cue during SWS produced better memory accuracy in comparison with REM and the control condition.

Screen Use at Bedtime and Sleep Duration and Quality Among Youths.

Although questionnaire-based cross-sectional research suggests that screen time before bed correlates with poor sleep, self-reported data seem unlikely to capture the complexity of modern screen use, requiring objective night-by-night measures to advance this field. To examine whether evening screen time is associated with sleep duration and quality that night in youths. This repeated-measures cohort study was performed from March to December 2021 in participant homes in Dunedin, New Zealand. Participants included healthy youths aged 11 to 14.9 years. Data were analyzed from October to November 2023. Objectively measured screen time, captured using wearable or stationary video cameras from 2 hours before bedtime until the first time the youth attempted sleep (shut-eye time) over 4 nonconsecutive nights. Video data were coded using a reliable protocol (κ = 0.92) to quantify device (8 options [eg, smartphone]) and activity (10 options [eg, social media]) type. Sleep duration and quality were measured objectively via wrist-worn accelerometers. The association of screen use with sleep measures was analyzed on a night-by-night basis using mixed-effects regression models including participant as a random effect and adjusted for weekends. Of the 79 participants (47 [59.5%] male; mean [SD] age, 12.9 [1.1] years), all but 1 had screen time before bed. Screen use in the 2 hours before bed had no association with most measures of sleep health that night (eg, mean difference in total sleep time, 0 minutes [95% CI, -3 to 20 minutes] for every 10 minutes more total screen time). All types of screen time were associated with delayed sleep onset but particularly interactive screen use (mean difference, 10 minutes; 95% CI, 4 to 16 minutes for every additional 10 minutes of interactive screen time). Every 10 minutes of additional screen time in bed was associated with shorter total sleep time (mean difference, -3 minutes; 95% CI, -6 to -1 minute). The mean difference in total sleep time was -9 minutes (95% CI, -16 to -2 minutes) for every 10 minutes of interactive screen use and -4 minutes (95% CI, -7 to 0 minutes) for passive screen use. In particular, gaming (mean difference, -17 minutes; 95% CI, -28 to -7 minutes for every 10 minutes of gaming) and multitasking (mean difference, -35 minutes; 95% CI, -67 to -4 minutes on nights with vs without multitasking) were associated with less total sleep time. In this repeated-measures cohort study, use of an objective method showed that screen time once in bed was associated with impairment of sleep, especially when screen time was interactive or involved multitasking. These findings suggest that current sleep hygiene recommendations to restrict all screen time before bed seem neither achievable nor appropriate.

The first-night effect of sleep occurs over nonconsecutive nights in unfamiliar and familiar environments.

The first night in an unfamiliar environment is marked by reduced sleep quality and changes in sleep architecture. This so-called first-night effect (FNE) is well established for two consecutive nights and lays the foundation for including an adaptation night in sleep research to counteract FNEs. However, adaptation nights rarely happen immediately before experimental nights, which raises the question of how sleep adapts over nonconsecutive nights. Furthermore, it is yet unclear, how environmental familiarity and hemispheric asymmetry of slow-wave sleep (SWS) contribute to the explanation of FNEs. To address this gap, 45 healthy participants spent two weekly separated nights in the sleep laboratory. In a separate study, we investigated the influence of environmental familiarity on 30 participants who spent two nonconsecutive nights in the sleep laboratory and two nights at home. Sleep was recorded by polysomnography. Results of both studies show that FNEs also occur in nonconsecutive nights, particularly affecting wake after sleep onset, sleep onset latency, and total sleep time. Sleep disturbances in the first night happen in both familiar and unfamiliar environments. The degree of asymmetric SWS was not correlated with the FNE but rather tended to vary over the course of several nights. Our findings suggest that nonconsecutive adaptation nights are effective in controlling for FNEs, justifying the current practice in basic sleep research. Further research should focus on trait- and fluctuating state-like components explaining interhemispheric asymmetries.

Effects of deep brain stimulation on quantitative sleep electroencephalogram during non-rapid eye movement in Parkinson's disease.

Sleep dysfunction is frequently experienced by people with Parkinson's disease (PD) and negatively influences quality of life. Although subthalamic nucleus (STN) deep brain stimulation (DBS) can improve sleep in PD, sleep microstructural features such as sleep spindles provide additional insights about healthy sleep. For example, sleep spindles are important for better cognitive performance and for sleep consolidation in healthy adults. We hypothesized that conventional STN DBS settings would yield a greater enhancement in spindle density compared to OFF and low frequency DBS. In a previous within-subject, cross-sectional study, we evaluated effects of low (60 Hz) and conventional high (≥130 Hz) frequency STN DBS settings on sleep macroarchitectural features in individuals with PD. In this post hoc, exploratory analysis, we conducted polysomnography (PSG)-derived quantitative electroencephalography (qEEG) assessments in a cohort of 15 individuals with PD who had undergone STN DBS treatment a median 13.5 months prior to study participation. Fourteen participants had unilateral DBS and 1 had bilateral DBS. During three nonconsecutive nights of PSG, the participants were assessed under three different DBS conditions: DBS OFF, DBS LOW frequency (60 Hz), and DBS HIGH frequency (≥130 Hz). The primary objective of this study was to investigate the changes in sleep spindle density across the three DBS conditions using repeated-measures analysis of variance. Additionally, we examined various secondary outcomes related to sleep qEEG features. For all participants, PSG-derived EEG data underwent meticulous manual inspection, with the exclusion of any segments affected by movement artifact. Following artifact rejection, sleep qEEG analysis was conducted on frontal and central leads. The measures included slow wave (SW) and spindle density and morphological characteristics, SW-spindle phase-amplitude coupling, and spectral power analysis during non-rapid eye movement (NREM) sleep. The analysis revealed that spindle density was significantly higher in the DBS HIGH condition compared to the DBS LOW condition. Surprisingly, we found that SW amplitude during NREM was significantly higher in the DBS LOW condition compared to DBS OFF and DBS HIGH conditions. However, no significant differences were observed in the other sleep qEEG features during sleep at different DBS conditions. This study presents preliminary evidence suggesting that conventional HIGH frequency DBS settings enhance sleep spindle density in PD. Conversely, LOW frequency settings may have beneficial effects on increasing slow wave amplitude during sleep. These findings may inform mechanisms underlying subjective improvements in sleep quality reported in association with DBS. Moreover, this work supports the need for additional research on the influence of surgical interventions on sleep disorders, which are prevalent and debilitating non-motor symptoms in PD.

0502 Number of Nights to Achieve High Sensitivity/Specificity for Detecting OSA Using a Large US Sample by Home Under-Mattress Devices

Abstract Introduction Clinical sleep studies typically rely on one night for OSA detection and diagnosis. However, uncertainty exists regarding the degree of AHI stability across different nights. Population studies collecting continuous nightly data on a large scale enable detection of night-to-night variability in OSA severity; this study is the largest to date for evaluation of the number of nights to achieve high sensitivity/specificity for OSA detection. Methods Sleep-disordered breathing was analyzed by a commercially available home monitoring device (Sleeptracker-AI Monitor, Fullpower Technologies Inc., California, USA) that passively monitors sleep using piezo-electric sensors. Validated sleep/respiratory parameters were derived from device data. De-identified data were analyzed, following review and exemption of the study (#57681) from Stanford University IRB. Data from 10/01/2021 to 09/30/2022 were reviewed in 96,228 individuals with 19,148,323 recorded nights. Individuals with at least 300 nights with a computed AHI (TST≥4hrs) were included in the analytic dataset. Results A total of 23,105 individuals (10,711 men, 49.6±12.93 years; 9,430 women, 49.4±12.85 years; 2,964 no gender provided, 50.4±14.37 years) with 7,947,840 recorded nights met the inclusion criteria. Maximum (but not mean) AHIs for each individual for 3 randomly-selected (vs. consecutive) nights revealed sensitivities (≥95%)/specificities [and CIs] of 94.9%[94.8,95.1]/82.5%[82.2,82.7], 95.2%[95.0,95.5]/94.3%[94.1,94.5], and 96.2%[95.8,96.6]/97.9%[97.8,98.0] for detecting any, moderate-to-severe, and severe OSA, respectively, as categorized by mean AHI over 1 year. Sensitivities for a single night were in the low 70s, and, for maximum AHI over two randomly-selected nights, near 90%, with a tradeoff for decreased specificities for 3+ nights. For moderate-to-severe and severe OSA subjects over 1 year, means of 5.1±7.7% and 5.4±7.3% nights, respectively, showed OSA severity decreases by 2+ categories (i.e., moderate to normal, severe to mild/normal). Conclusion Use of a noninvasive in-home monitoring device enabling collection and analysis of a large sample of sleep/respiratory data on a continuous nightly basis showed that a single night yields low sensitivity for detection of OSA and on average OSA severity decreased by 2 categories on 5% or more nights. Maximum (but not mean) AHI across 3 non-consecutive nights yields good sensitivities/specificities for moderate-to-severe and severe OSA detection. Ongoing work explores statistics for nights beyond 3 to further improve sensitivity/specificity. Support (if any)

0302 Recovery Sleep in University Students

Abstract Introduction Poor sleep hygiene is common in American college students, with the majority reporting insufficient sleep. Previous studies suggest that many students extend sleep during the weekend to recover sleep debt accrued during the week. In the current study we objectively measured sleep to determine if weekend catch-up sleep was practiced. We also provided students with a 9h sleep opportunity in order to observe how an extended sleep period affected sleep architecture. Methods Students (N=36, 20 women, 19.9±1.7 years) participated in the study from September 2019-March 2020. Sleep-wake behavior was assessed for two weeks using wrist actigraphy and a twice-daily diary. During this two-week period, participants wore at-home polysomnography (PSG) on two non-consecutive nights. For these two nights, in counterbalanced order, participants were instructed to follow their typical sleep pattern or to extend their sleep opportunity to 9h. Within-subjects ANOVA were used to compare sleep between week (Sunday-Thursday) and weekend (Friday and Saturday) nights as well as between typical and 9h PSG nights. Results Compared to week nights, participants went to bed 35 minutes later and woke up 58 minutes later on weekend nights (ps<0.01). Measures of sleep duration and sleep continuity were comparable (ps>0.10) between week and weekend nights and indicated that students averaged less than 7h of sleep per night (6.3±1.0h on week nights and 6.7±1.1h on weekend nights). Self-report measures of sleep quality and daytime sleepiness were also comparable between week and weekend nights (ps>0.05). When instructed to extend their sleep opportunity to 9h, participants exhibited high adherence and increased total sleep time by 88 minutes compared to the typical night (p<0.05). This increase in sleep was due to significant increases in time spent in all four stages of sleep (NREM S1-3 and REM sleep, ps<0.05). Conclusion In this study, students did not utilize weekend nights to extend sleep in order to recover accumulated sleep debt from the week. When provided with a 9h sleep opportunity, participants were physically able to extend sleep and exhibited high quality sleep, suggesting that the primary driver of insufficient sleep in this population is a lack of sleep opportunity rather than impaired sleep ability. Support (If Any)

P056 Using Polysomnography in Young People with Borderline Personality Disorder: A Pilot and Feasibility Study

Abstract Introduction Few studies have assessed sleep in young people (aged 15–25 years) with BPD using polysomnography. The feasibility of using polysomnography in this population might be questioned due to polysomnography’s invasiveness, anxiety and sensory sensitivities in BPD, and misconceptions that individuals with BPD are uncooperative and non-compliant. This study aimed to provide pilot sleep quality and architecture data and assess polysomnography feasibility. Method Participants were 13 females aged 15–25, 7 (Mage = 19.97, SD = 3.15) with BPD and 6 age-matched healthy controls (Mage = 20.13, SD = 3.31). Participants completed two non-consecutive nights of polysomnography monitoring (second night’s data were used in analyses). Participants were given the option of completing polysomnography monitoring at home or in a sleep laboratory. Results Young people with BPD displayed less arousals across the night and specifically during NREM sleep compared with healthy young people. All other sleep parameters were comparable across groups. There was considerable heterogeneity among participant preferences for in-home vs. sleep laboratory-based monitoring, due to comfort, safety, convenience, interest in seeing a sleep laboratory, or their living situation (eg. presence of bed partner at home). Anxiety was identified as a potential barrier to polysomnography research in this population. Discussion There were some indications of more consolidated sleep in BPD, which might reflect a greater sleep need in this population. The feasibility and tolerability of in-home and sleep laboratory-based polysomnography were demonstrated. Future protocols should incorporate ways to minimise anxiety, for example through providing a choice of monitoring location.

Optical Analysis and Modeling of HD96670, a New Black Hole X-Ray Binary Candidate

Abstract We report on optical observations and modeling of HD96670, a single-line spectroscopic binary in the Carina OB2 association. We collected 10 epochs of optical spectroscopy, and optical photometry on 17 nonconsecutive nights on the source. We construct a radial velocity curve from the spectra, and update the orbital period of the binary to be P = 5.28388 ± 0.00046 days. The spectra show oxygen and helium absorption, consistent with an O-type primary. We see no evidence for spectral lines from the secondary star in the binary. We model the optical light curve and radial velocity curve simultaneously using the Wilson–Devinney code and find a best-fit mass of for the primary, and for the secondary. An object of this mass is consistent with either a B-type star, or a black hole. Given that we see no absorption lines from the secondary, in combination with an observed hard power-law X-ray spectrum with Γ = 2.6 detected past 10 keV that may have been produced by wind accretion onto the secondary, we conclude that the secondary is most likely a black hole. We see asymmetrical helium lines with a shape consistent with the presence of a third star. If the secondary is indeed a black hole, this system would add to the small sample of only four possible black hole high mass X-ray binaries in the galaxy.

Time Course of Sleep Inertia Dissipation in Memory Tasks

Sleep inertia (SI) refers to a complex psychophysiological phenomenon, observed after awakening, that can be described as the gradual recovery of waking-like status. The time course of cognitive performance dissipation in an everyday life condition is still unclear, especially in terms of the sleep stage at awakening (REM or NREM-stage 2) and the relative effects on performance. The present study aimed to investigate the SI dissipation in different memory performances upon spontaneous morning awakening after uninterrupted nighttime sleep. Eighteen young adults (7 females; mean age 24.9 ± 3.14 years) spent seven non-consecutive nights (one baseline, three REM awakenings and three St2 awakenings) in the laboratory under standard polysomnographic (PSG) control. Participants were tested after three REM awakenings and three St2 awakenings, and three times at 11:00 a.m. as a control condition. In each testing session, participants filled in the Global Vigor and Affect Scale and carried out one memory task (episodic, semantic, or procedural task). For each condition, participants were tested every 10 min within a time window of 80 min. In accordance with previous studies, SI affected subjective alertness throughout the entire time window assessed. Moreover, SI significantly affected performance speed but not accuracy in the semantic task. With reference to this task, the SI effect dissipated within 30 min of awakening from REM, and within 20 min of awakening from St2. No significant SI effect was observed on episodic or procedural memory tasks.

Dynamical modelling of CXOGBS J175553.2−281633: a 10 h long orbital period cataclysmic variable

ABSTRACT We present modelling of the long-term optical light and radial velocity curves of the binary stellar system CXOGBS J175553.2−281633, first detected in X-rays in the Chandra Galactic Bulge Survey. We analysed 7 yr of optical I-band photometry from Optical Gravitational Lensing Experiment and found long-term variations from year to year. These long-term variations can most likely be explained with by either variations in the luminosity of the accretion disc or a spotted secondary star. The phased light curve has a sinusoidal shape, which we interpret as being due to ellipsoidal modulations. We improve the orbital period to be P = 10.34488 ± 0.00006 h with a time of inferior conjunction of the secondary star T0 = HJD 2455260.8204 ± 0.0008. Moreover, we collected 37 spectra over 6 non-consecutive nights. The spectra show evidence for an evolved K7 secondary donor star, from which we obtain a semi-amplitude for the radial velocity curve of K2 = 161 ± 6 km s−1. Using the light-curve synthesis code xrbinary, we derive the most likely orbital inclination for the binary of i = 63.0 ± 0.7 deg, a primary mass of M1 = 0.83 ± 0.06 M⊙, consistent with a white dwarf accretor, and a secondary donor mass of M2 = 0.65 ± 0.07 M⊙, consistent with the spectral classification. Therefore, we identify the source as a long orbital period cataclysmic variable star.

The effect of nocturnal “meat” versus “vegetarian” dinners on sleep quality and daily functioning

Sleep and nutrition are central to an organism's continued physiological existence. Moreover, both of these functions include significant social-behavioral, educational, and cultural elements. This study examined the effects of two types of nocturnal dinners ("vegetarian" versus "meat") on the quality and quantity of sleep, as well as on subjective sleepiness and attention levels the following morning. 20 healthy subjects (10 men and 10 women) participated in a lab polysomnography study for two non-consecutive nights at the Sleep Institute at Tel-Hai College. They completed questionnaires (Karolinska Sleepiness Scale (KSS) and Brief Symptom Inventory Questionnaire (BSI)), as well as a computerized attention and concentration test (Conner's Continuous Performance Test-III (CPT-III)), on the mornings after each night of polysomnography. On the first night, subjects consumed a vegetarian meal made up of non-animal ingredients (vegetables and vegetable proteins). On the second night, they were given a meat meal composed of carbohydrates, fats, and animal proteins. No significant differences were measured in the various sleep parameters: efficacy, structure, and quality of sleep. There were also no significant differences found in the behavioral measures examined: subjective sleepiness (KSS), mood (BSI), and attention and concentration abilities (CPT-III). The findings of this study indicate that, contrary to popular belief, consuming a meat dinner may not affect a person's quality of sleep, or their ability to function the morning after, differently than a vegetarian dinner. Future studies should further examine the relationship between sleep and nutrition. The clinical trial is registered under the number 0010-18ASMC.

Wake Up, Work on Dreams, Back to Bed and Lucid Dream: A Sleep Laboratory Study.

Lucid dreaming offers many opportunities to study consciousness processes. However, laboratory research in this area is limited because frequent lucid dreamers are rare. Several studies demonstrated that different methods of induction could increase the number of lucid dreams. In four field studies, a combination of a wake-up-back-to-bed (WBTB) sleep protocol and a mnemonic technique (MILD) showed promising results. To further investigate the effectiveness of this combined approach, we conducted a sleep laboratory experiment with four different conditions. The general experimental procedure was the following: Participants were awakened after 6 h of sleep from a subsequent REM period and kept awake for 30 or 60 min, during which they were asked to practice MILD or a control task (e.g., reading). Then they returned to bed for a morning sleep period. In the first condition eleven sport students, who attended a seminar on sleep and dreams, spent one night in a sleep laboratory. To avoid biases due to the seminar attendance (e.g., higher motivation), in the second condition 15 participants who did not attend the seminar were recruited. In the third condition, 14 sport students were tested with a shorter awakening period (30 min). Finally, the fourth condition served as a control condition, whereas eleven sport students slept two non-consecutive nights in a laboratory. Instead of MILD, in one night the participants read a book (fiction, unrelated to dreams), while in the other night they played a Nintendo Wii video game. In the first three conditions, six (54%), eight (53%), and five participants (36%) reported lucid dreams during the morning sleep period, whereas three, (27%), four (27%), and two participants (14%) produced PSG-verified eye signals. In contrast, in the reading condition, only one (9%) participant reported lucid dreams and no eye movements. No lucid dreams were observed in the Wii condition. The findings of the present study show that by using a combination of WBTB and MILD, lucid dreams can be effectively induced in people who are not selected for their lucid dream abilities.

0167 The Effect of Nocturnal Dinner Type “Light” Versus “Heavy” on Sleep, Attention and Microbial Composition

Abstract Introduction Nutrition and sleep are two essential functions for the physiological existence of the organism. Furthermore, both have an acquired cultural, educational and social behavioral component. This study examined the effect of nocturnal dinner type (“light” vs. “heavy”) on the quality and quantity of sleep, attention abilities, fatigue, and mood in the following morning. In addition, the microbial composition was examined. Methods Twenty healthy subjects (10 men and 10 women), aged 25–33, were invited to two non-consecutive nights at the Sleep Institute for polysomnography test and filling out questionnaires: KSS; ESS; and Brief Symptom Inventory (BSI), attention abilities assessed with CPT-III. In one evening, the subjects consumed two hours before bedtime a “light” dinner based on vegetable ingredients (vegetables and vegetable proteins) with 342 calories that contained lentils, feta cheese, beet, and other vegetables. On the other evening, the subjects consumed two hours before bedtime a “heavy” dinner based on carbohydrates, fats, and animal protein with 501 calories that contained hamburger and French fries. In addition, subjects were required to give a microbial test before and after meals. Results There was no significant difference in the various sleep parameters between the two nights after each meal type: efficacy (t=-1.51,p=0.15); sleep latency stage 1 (t=1.81,p=0.08); sleep latency stage 2 (t=1.00,p=0.33); REM latency (t=0.57,p=0.57); total sleep time (t=-1.57,p=0.13); number of awakenings (t=0.30, p=0.76). No significant differences were found for: fatigue (KSS) (t=-0.30,p =0.77); sleepiness (ESS) (t=0.76,p =0.45); mood (BSI) (t=0.87,p =0.39); and attention deficit (CPT-III) (t=-0.68,p =0.50). The type of night meal did not show a significant effect on the microbial composition (H=0.059,p= 0.81). Conclusion The findings of this study show that, contrary to popular belief, “heavy” dinner did not affect the quality of sleep and functions measured in the study compared to a “light” dinner. In the current research, the population that was examined included only young and healthy subjects, therefore, the results may differ if the research in this field will extend and include other populations such as adults and subjects with different disorders. Future studies are needed to examine the relationships between sleep and nutrtion. Support No support

Sleep, Experimental Pain and Clinical Pain in Patients with Chronic Musculoskeletal Pain and Healthy Controls.

PurposeEveryday variations in night sleep in healthy pain-free subjects are at most weakly associated with pain, whereas strong alterations (eg, sleep deprivation, insomnia) lead to hyperalgesic pain changes. Since it remains unclear how substantial sleep alterations need to be in order to affect the pain system and lead to a coupling of both functions, the present study aimed at providing sufficient variance for co-variance analyses by examining a sample consisting of both healthy subjects and chronic pain patients.MethodsA sample of 20 chronic musculoskeletal pain patients and 20 healthy controls was examined. This sample was assumed to show high inter-individual variability in sleep and pain, as pain patients frequently report sleep disturbances, whereas healthy subjects were required to be pain-free and normal sleepers. Sleep of two non-consecutive nights was measured using portable polysomnography and questionnaires. Experimental pain parameters (pressure pain thresholds (PPT), temporal summation of pain (TSP), conditioned pain modulation (CPM)) and situational pain catastrophizing (SCQ) were assessed in laboratory sessions before and after sleep. Pain patients’ clinical pain was assessed via questionnaire.ResultsAs expected, both groups differed in several sleep parameters (reduced total sleep time and sleep efficiency, more time awake after sleep onset, lower subjective sleep quality in the patients) and in a few pain parameters (lower PPTs in the patients). In contrast, no differences were found in TSP, CPM, and SCQ. Contrary to our expectations, regression analyses indicated no prediction of overnight pain changes by sleep parameters.ConclusionSince sleep parameters were hardly apt to predict overnight pain changes, this leaves the association of both systems mainly unproven when using between-subject variance for verification.

Diversity and community structure of bats (Chiroptera) in the Centre Region of Cameroon

AbstractIn this survey, we investigated the diversity and community structure of bats in the Centre Region of Cameroon with respect to their distribution in the different vegetation zones of the region. We mist‐netted bats monthly from January 2016 to June 2017 for five nonconsecutive nights per month. Thirty‐nine sites were surveyed: 24 in traditional farms, nine in the savannah and six in the forests. A total of 668 bats were captured during 81 nights of capture, covering seven families, 21 genera and 36 species. This included 26 species in traditional farms, 13 species in savannah and 11 species in the forest. Micropteropus pusillus was the most abundant species (30.7%) recorded, followed by Hipposideros ruber (24.9%). The sample efficiency was estimated at 72.1% with fitted species accumulation curves not reaching asymptotes for the three habitat types, suggesting that the survey did not record all the bats present. There was an indication of general increased in abundance of bats during the dry and rainy seasons but it is not significant (Mann–Whitney U: 783.5, p = .195). The rarity index was highest in traditional farms (0.44), followed by savannah (0.38) and then forest (0.33). This preliminary survey provides baseline data on the distribution of bats in the different vegetation types in the Centre Region of Cameroon.

Use of linear features by the common vampire bat (Desmodus rotundus) in a tropical cattle-ranching landscape

Linear landscape features are used by many species of insectivorous bats as flight routes and foraging zones, as well as for providing protection against environmental factors and predation. However, very little is known about the role that these landscape features play for non-insectivorous species. In this study, we evaluated the use of linear features by the common vampire bat (Desmodus rotundus) in a cattle-ranching landscape in the state of Tabasco, Mexico. We selected 24 sampling sites in 2014 and 24 independent sites in 2016 to 2017, all adjacent to three types of linear landscape features: forest edges, live fences and streams . We monitored each site for two non-consecutive nights between February and April 2014, and every two months from February 2016 to June 2017. We placed 24 m (2014) or 12 m (2016 to 2017) of mist nets perpendicular to the linear feature from its edge. We recorded the height and distance from the edge for each individual captured. In total we captured 50 D. rotundus individuals in 2014 and 58 in 2016 to 2017. The average flight height was 77 cm for the 2014 data and 69 cm for 2016 to 2017. According to our results, the most used linear features were forest edges, followed by live fences and streams. Overall, 52 % of the 2014 captures and 62 % of the 2016 to 2017 ones occurred in the first 2 m from the edge, with the number of captures gradually decreasing with increasing distance. This study provides information on the commuting patterns of D. rotundus in predominantly open cattle-ranching landscapes.

A Preliminary Study Investigating the Influence of Auditory Stimulation on the Occurrence of Nocturnal Equine Sleep-Related Behavior in Stabled Horses

The physical environment is known to influence nocturnal behavioral time budgets of the stabled horse, but less evidence exists to suggest how this might be affected by including additional sensory stimuli. This study aimed to establish the impact of novel auditory stimuli on the frequency of equine sleep-related behavior. Seven horses stabled for 24 hours per day on the same yard receiving the same daily management routine were observed from 2030 to 0630 over nine nights. Frequency of nocturnal behavior was recorded using focal intermittent sampling against a predetermined ethogram and an infrared CCTV camera system. Data were recorded under the following conditions: without music for two nights (phase A1), exposure to music for five nights (Beethoven's ninth Symphony) played at an average of 62.3 decibels (phases B1 [nights 3-4] and B2 [nights 6-7]), and two further nonconsecutive nights (phase A2) when music was no longer played. A general linear model was used to determine differences in the frequency of parametric behavioral data with a significantly higher occurrence of “ingestion” (F [3,18] = 7.910, P = .001) during phases in B compared with A, and a significant decrease in the occurrence of “other” behavior (F [3,18] = 10.25, P = .000) comparing phase A1 with all other phases. The Wilcoxon signed rank test highlighted significant differences in the frequency of “lateral recumbency” between specific phases (P < .05). The addition of music appears to have a significant effect on the equine nocturnal time budget that might be beneficial from an equine sleep perspective.

Sleep Parameter Assessment Accuracy of a Consumer Home Sleep Monitoring Ballistocardiograph Beddit Sleep Tracker: A Validation Study.

Growing interest in monitoring sleep and well-being has created a market for consumer home sleep monitoring devices. Additionally, sleep disorder diagnostics, and sleep and dream research would benefit from reliable and valid home sleep monitoring devices. Yet, majority of currently available home sleep monitoring devices lack validation. In this study, the sleep parameter assessment accuracy of Beddit Sleep Tracker (BST), an unobtrusive and non-wearable sleep monitoring device based on ballistocardiography, was evaluated by comparing it with polysomnography (PSG) measures. We measured total sleep time (TST), sleep onset latency (SOL), wake after sleep onset (WASO), and sleep efficiency (SE). Additionally, we examined whether BST can differentiate sleep stages. We performed sleep studies simultaneously with PSG and BST in ten healthy young adults (5 female/5 male) during two non-consecutive nights in a sleep laboratory. BST was able to distinguish SOL with some accuracy. However, it underestimated WASO and thus overestimated TST and SE. Also, it failed to discriminate between non-rapid eye movement sleep stages and did not detect the rapid eye movement sleep stage. These findings indicate that BST is not a valid device to monitor sleep. Consumers should be careful in interpreting the conclusions on sleep quality and efficiency provided by the device.

Bats Assemblage and Lunar Phase Effect on Bat Activity at Mixed Dipterocarp Forest, Gunung Gading National Park, Sarawak, Borneo

Bat surveys at Gunung Gading National Park (GGNP) were conducted for 29 non-consecutive nights, which consisted of five separate sampling sessions from November 2011 until November 2015. A total of 378 individuals representing 36 species from six families were captured, from an accumulated effort of 435 trapping nights. This corresponds to approximately 39% (n=36) of the total species recorded in Borneo. The most commonly captured species in GGNP for insectivorous bats was Rhinolophus affinis (20.1%), whereas for frugivorous bats Penthetor lucasi (14.3%) dominated the capture. Species accumulation curve reached asymptote on the 24th sampling night suggesting that sampling saturation has been achieved for the trapping sites studied here. The species diversity (H’= 2.75) showed relatively high diversity of bat species in the park compared to other actively surveyed sites in western Sarawak including Bako National Park (Bako NP), Kubah National Park (Kubah NP) and Mount Penrisen (Mt Penrisen). This was further supported through rarefaction analysis showing that GGNP has largest value of estimated species compared to other actively surveyed sites in western Sarawak. Lunar phase and bat capture rate correlation analysis showed that there is no statistically significant relationship between lunar phase and the bat capture rate at GGNP. This suggests that bat activity reported here were not affected by moonlight. The results from these surveys provided the most comprehensive list of bats for GGNP. Our study highlights the importance of GGNP as an important habitat for bat conservation including the rare bat species found in Borneo, Phoniscus atrox.

The Effects of Low Air Temperatures on Thermoregulation and Sleep of Young Men While Sleeping Using Bedding

Most people do not use heating systems during nocturnal sleep in their bedrooms during the cold season in Japan; instead, they like to use extra blankets and quilts for sleeping. To investigate the effect of low air temperature (Ta) on sleep and thermoregulation when sleeping with bedding, 12 healthy young men participated in sleep experiments over three non-consecutive nights. The experimental conditions were at a Ta of 3 °C, 10 °C and 17 °C, with a relative humidity (Rh) of 50% and an air velocity of &lt;0.2 m/s in the climatic chambers. The 4.3-clo bedding consisted of cotton sheets, an acrylic blanket, a down-filled quilt and a futon mattress. The average sleep efficiency index (SEI) remained &gt;94% for each of the three Tas, and no disturbances were found by Ta in the sleep parameters, although the duration of rapid eye movement (REM) sleep showed variations at 3 °C. The skin temperature (Ts) of the forehead decreased in proportion to Ta and remained stable. The decreasing rate in rectal temperature (Tre), Ts of forehead and thigh during sleep were significantly greater at 3 °C than at 10 °C and 17 °C. The innermost microclimate temperature (Tmicro) made by the bedding did not correlate with the Tre. The young men were significantly more dissatisfied with 3 °C in the sleep quality evaluation.