Control Night 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.

Acute Responses to Repeated-SprintTraining in Hypoxia Combined With Whole-Body Cryotherapy: A Preliminary Study.

This study aimed to investigate acute psychophysiological responses to repeated-sprint training in hypoxia (RSH) combined with whole-body cryotherapy (WBC). Sixteen trained cyclists performed 3 sessions in randomized order: RSH, WBC-RSH (WBC pre-RSH), and RSH-WBC (WBC post-RSH). RSH consisted of 3 sets of 5 × 10-second sprints with 20-second recovery at a simulated altitude of 3000m. Power output, muscle oxygenation (tissue saturation index), heart-rate variability, and recovery perception were analyzed. Sleep quality was assessed on the nights following test sessions and compared with a control night using nocturnal ActiGraphy and heart-rate variability. Power output did not differ between the conditions (P = .27), while the decrease in tissue saturation index was reduced for WBC-RSH compared to RSH-WBC in the last set. In both conditions with WBC, the recovery perception was higher compared to RSH (WBC-RSH: +15.4%, and RSH-WBC: +21.9%, P < .05). The number of movements during the RSH-WBC night was significantly lower than for the control night (-18.7%, P < .01) and WBC-RSH (-14.9%, P < .05). RSH led to a higher root mean square of the successive differences of R-R intervals and high-frequency band during the first hour of sleep compared to the control night (P < .05) and RSH-WBC (P < .01). Inclusion of WBC in an RSH session did not modify the power output but could improve prolonged performance in hypoxia by maintaining muscle oxygenation. A single RSH session did not deteriorate sleep quality. WBC, particularly when performed after RSH, positively influenced recovery perception and sleep.

P013 The Effect of Noise Exposure during Sleep on the Cortisol Awakening Response

Abstract Introduction Environmental noise could negatively impact the sleep and well-being of nearby residents. This study tested for overnight noise exposure effects on the cortisol awakening response (CAR), a potential marker of noise-related stress responses, and for differences in CAR and hair cortisol between different prior noise exposure groups. Methods A randomised controlled laboratory trial was conducted in 68 individuals from four groups; including WFN-exposed residents n=14 with and n=18 without WFN-related complaints, n=18 quiet rural control and n=18 urban traffic-noise exposed residents. Across six nights, after an initial adaptation night, participants were exposed in random order to different noise conditions, which included intermittent WFN and road traffic noise (RTN), WFN at average exposure levels throughout wake, sleep or both and a quiet control night. Salivary CAR responses were evaluated from 5 serial saliva samples collected following awakening. Hair cortisol levels were also collected. Mixed effects models were used to examine group and night effects on CAR and group effects on hair cortisol. Results There was a significant main effect of condition on CAR (p=0.038), but no significant pairwise differences between the control night and noise exposure nights, and no further differences between nights or groups on CAR or hair cortisol concentrations. Conclusions Acute in-laboratory noise-related sleep disturbance at the levels used in this study do not appear to alter acute cortisol awakening responses. A better understanding of chronic noise exposure effects and stress responses is important to help clarify and mitigate potential environmental noise exposure effects on nearby residents.

O049 A Quantitative EEG Analysis of Overnight Noise Exposure Effects on Sleep– A Laboratory Study

Abstract The impact of overnight wind farm noise exposure on sleep is unclear and traditional manual sleep scoring may not be sensitive enough to detect subtle changes in sleep. This study used quantitative EEG (qEEG) to assess subtle effects of noise on sleep under well-controlled laboratory conditions. Sixty-eight individuals (Males: Females; 30:38) aged (Median [IQR]) 55.5yrs [31.3-66.3], from four groups (rural residents with and without WFN-related complaints, control rural residents, and urban traffic noise-exposed residents) underwent overnight polysomnography during six different noise exposure nights in random order. Noises included 20sec and 3min intermittent road traffic and wind farm noise exposures (full night averages 42dBA and 32dBA, respectively), continuous and intermittent wind farm noise at 25dBA, and a quiet control night (background noise,19dBA). Traditional polysomnography sleep metrics, qEEG power in delta (0.5-4Hz) to beta (32Hz) frequencies, and K-complex density (events/min) were compared between noise conditions, groups and sleep stages using likelihood ratio tests. Wake after sleep onset, time spent in N1 sleep and relative beta activity were higher, whilst time spent in N3 was reduced on the 20 second noise exposure night compared to control (all p&amp;lt;0.05). Full night average qEEG outcomes were not different between nights. K-complex density was significantly increased during both 20sec and 3min intermittent noise exposure conditions compared to control (p&amp;lt;0.001). Full night qEEG outcomes do not appear to be more sensitive to noise related sleep disturbance than traditional sleep scoring methods. However, K-complex density assessments may be particularly useful in future studies of noise effects on sleep.

Cannabis use following bariatric surgery is associated with anxiety and maladaptive eating

BackgroundThere are limited data regarding the association of cannabis use with outcomes after bariatric surgery. As such, it is challenging to know how to counsel patients using cannabis. ObjectivesThe purpose of this study was to examine whether postsurgical cannabis use was associated with psychiatric symptoms and maladaptive eating among individuals up to 4 years after bariatric surgery. SettingSingle health system. MethodsAll patients who underwent bariatric surgery over a 4-year period were invited to participate. Participants (N = 765) completed questionnaires online regarding postsurgical cannabis use, psychiatric symptoms, and maladaptive eating. ResultsAny cannabis use after bariatric surgery was associated with increased likelihood of having elevated symptoms of anxiety (odds ratio [OR] = 1.88, P = .003; 37.8% versus 24.4%), increased likelihood of grazing behaviors (OR = 1.77, P = .01; 71.2% versus 58.2%), and higher scores for eating in response to depression (P = .01; 12.13 versus 10.75). Weekly cannabis use was associated with loss of control eating (OR = 1.81, P = .04; 37.2% versus 24.7%), binge eating (OR = 2.16, P = .03; 20.0% versus 10.4%), and night eating behaviors (OR = 2.11, P = .01; 40.0% versus 24.0%). Cannabis use was not associated with depression (P > .05). ConclusionsCannabis use after bariatric surgery was associated with anxiety symptoms and engaging in maladaptive eating behaviors. Frequent cannabis use (i.e., ≥1 per week) was associated with additional types of maladaptive eating. Clinicians involved in presurgical and postsurgical care may want to counsel patients currently using cannabis, especially those who are engaging in frequent use.

Utilization of UGV in Mining Sectors

In various sectors such as defense and mining, existing Unmanned Ground Vehicle (UGV) applications face specific limitations, including the inability to achieve wide- range control and operate in dark environments. To mitigate human risks and reduce human involvement in bomb disposal operations, the need for UGVs has become crucial. In this context, we propose a model/framework that utilizes gas and temperature sensors to detect environmental conditions. Our framework aims to enhance UGV applications by incorporating wide-range Wi-Fi enabled control devices and night mode camera functionality. This enables rapid object detection over a greater distance and emphasizes remote control through a mobile application. As a result, the proposed system automates the process of bomb disposal, thereby reducing human risks involved in such operations.

0157 Physiological responses to acute psychosocial stress in adolescents with insomnia

Abstract Introduction Insomnia often develops during adolescence, with girls being at greater risk than boys. Alterations in response to psychosocial stress have been linked to the etiology of the disorder, but it remains unclear whether the reactivity of the major stress systems (hypothalamic-pituitary-adrenal (HPA) axis and autonomic nervous system (ANS)) in response to stress is altered in adolescents with insomnia. Methods Forty-seven post-pubertal adolescents (age range: 16-20 years, 28 female) with (N=16; insomnia group) and without (N=31; control group) insomnia symptomatology underwent two randomized nights of polysomnographic (PSG) laboratory recordings. Participants underwent an experimental pre-bedtime stress anticipation protocol (stress night) and a control night during which they engaged in neutral activities before bedtime. The morning after the stress night, participants underwent the Trier Social Stress Test (TSST), a standardized protocol that requires participants to complete verbal and arithmetic tasks in front of observers. On both nights, heart rate (HR) was measured across the night and cortisol was collected upon awakening and 30 minutes later to calculate cortisol awakening responses (CAR). Stress perception, salivary cortisol (HPA activity), and HR were measured during the TSST. Results There were no differences in nocturnal HR recovery or in the CAR on the stress night compared with the control night in either group. Morning pre-TSST stress levels did not differ between groups. Both groups exhibited significant increases in HR in response to the TSST (p&amp;lt; 0.05). HR was higher in girls compared to boys in the control group at baseline (p&amp;lt; 0.05). Potential group differences in HPA responses to the TSST were inconclusive due to the apparent confounding effect of the CAR on cortisol responses to stress: many participants did not show a cortisol response to the task and larger CARs were associated with an attenuated cortisol response. Conclusion There were no significant differences in HR responses to anticipation of experimental stress during the night or in response to the morning TSST between adolescents with and without insomnia. Further work is needed to examine whether altered responses to stress may emerge if insomnia becomes chronic. Support (if any) This study was supported by the National Heart, Lung and Blood Institute (NHLBI) grant R01HL139652(MdZ).

Eye movements during phasic vs. tonic REM sleep are biomarkers of dissociable EEG processes for the consolidation of novel problem-solving skills.

The hallmark eye movement (EM) bursts that occur during Rapid Eye Movement (REM) sleep are markers of consolidation for procedural memory involving novel cognitive strategies and problem-solving skills. Examination of the brain activity associated with EMs during REM sleep might elucidate the processes involved in memory consolidation, and may uncover the functional significance of REM sleep and EMs themselves. Participants performed a REM-dependent, novel procedural problem-solving task (i.e., the Tower of Hanoi; ToH) before and after intervals of either overnight sleep (n=20) or a daytime 8-hour wake period (n=20). In addition, event-related spectral perturbation (ERSP) of the electroencephalogram (EEG) time-locked to EMs occurring either in bursts (i.e., phasic REM), or in isolation (i.e., tonic REM), were compared to sleep on a non-learning control night. ToH improvement was greater following sleep compared to wakefulness. During sleep, frontal-central theta (~2-8 Hz) and central-parietal-occipital sensorimotor rhythm (SMR) activity (~8-16 Hz) time-locked to EMs, were greater on the ToH night vs. control night, and during phasic REM sleep, were both positively correlated with overnight memory improvements. Furthermore, SMR power during tonic REM increased significantly from the control night to ToH night, but was relatively stable from night-to-night during phasic REM. These results suggest that EMs are markers of learning-related increases in theta and SMR during phasic and tonic REM sleep. Phasic and tonic REM sleep may be functionally distinct in terms of their contribution to procedural memory consolidation.

Response of sleep slow oscillations to acoustic stimulation is evidenced by distinctive synchronization processes.

Closed-loop acoustic stimulation (CLAS) during sleep has shown to boost slow wave (SW) amplitude and spindle power. Moreover, sleep SW have been classified based on different processes of neuronal synchronization. Thus, different types of SW events may have distinct functional roles and be differentially affected by external stimuli. However, the SW synchronization processes affected by CLAS are not well understood. Here, we studied the effect of CLAS on the dissociation of SW events based on two features of neuronal synchronization in the electroencephalogram (topological spread and wave slope). We evaluated and classified individual SW events of 14 healthy subjects during a CLAS stimulated (STM) and a control night (CNT). Three main categories of SW events were found denoting (C1) steep slope SW with global spread, (C2) flat-slope waves with localized spread and homeostatic decline, and (C3) multipeaked flat-slope events with global spread. Comparing between conditions, we found a consistent increase of event proportion and trough amplitudes for C1 events during the time of stimulation. Furthermore, we found similar increases in post-stimulus spectral power in θ, β, and σ frequencies for CNT vs STIM condition independently of sleep stage or SW categories. However, topological analysis showed differentiated spatial dynamics in N2 and N3 for SW categories and the co-occurrence with spindle events. Our findings support the existence of multiple types of SW with differential response to external stimuli and possible distinct neuronal mechanisms.

Sleep Patterns Fluctuate Following Training and Games across the Season in a Semi-Professional, Female Basketball Team.

Quantifying athlete sleep patterns may inform development of optimal training schedules and sleep strategies, considering the competitive challenges faced across the season. Therefore, this study comprehensively quantified the sleep patterns of a female basketball team and examined variations in sleep between nights. Seven semi-professional, female basketball players had their sleep monitored using wrist-worn activity monitors and perceptual ratings during a 13-week in-season. Sleep variables were compared between different nights (control nights, training nights, training nights before games, nights before games, non-congested game nights, and congested game nights), using generalized linear mixed models, as well as Cohen's d and odds ratios as effect sizes. Players experienced less sleep on training nights before games compared to control nights, training nights, nights before games, and congested game nights (p < 0.05, d = 0.43-0.69). Players also exhibited later sleep onset times on non-congested game nights compared to control nights (p = 0.01, d = 0.68), and earlier sleep offset times following training nights before games compared to all other nights (p < 0.01, d = 0.74-0.79). Moreover, the odds of players attaining better perceived sleep quality was 88% lower on congested game nights than on nights before games (p < 0.001). While players in this study attained an adequate sleep duration (7.3 ± 0.3 h) and efficiency (85 ± 2%) on average across the in-season, they were susceptible to poor sleep on training nights before games and following games. Although limited to a team-based case series design, these findings suggest basketball coaches may need to reconsider scheduling team-based, on-court training sessions on nights prior to games and consider implementing suitable psychological and recovery strategies around games to optimize player sleep.

Traffic noise affects foraging behavior and echolocation in the Lesser Bulldog Bat, Noctilio albiventris (Chiroptera: Noctilionidae)

Urban noise, such as that of traffic, can affect the sensory capabilities in animals. Foragers acting optimally are expected to exploit feeding patches depending on the cost/benefit ratio, and some noises can cause increased foraging costs. We hypothesized that traffic noise affects foraging patch quality for aerial-insectivorous bats and predicted that there are measurable differences in their foraging activity and in their echolocation signals between nights with or without traffic noise. We tested these predictions in the Lesser Bulldog Bat, Noctilio albiventris, foraging over aquaculture fishponds, by recording bat activity on nights playing traffic noise and on traffic-sound free control nights. We measured foraging activity by counting the number of search passes and feeding buzzes made by the bats and measured several characteristics of echolocation signals. Foraging activity was higher during noisy nights than during control ones, probably due to the need of more time to obtain information about prey under noisy conditions. When exposed to traffic noise, the bats changed the spectral and temporal characteristics of echolocation signals. We suggest that exposure to traffic noise increases foraging costs for N. albiventris and posit that these bats continue foraging under noisy conditions because they can modulate their echolocation signals to obtain enough information.

Novel temperature-controlled sleep system to improve sleep: aproof-of-concept study.

The sleep-wake cycle is regulated by circadian Process C and homeostatic Process S. Selective thermal stimulation (STS) of the cervical spine region enhances glabrous skin blood flow (GSBF) and augments body heat dissipation to increase distal-to-proximal skin gradient (DPG) causing decrease of core body temperature (CBT), which can shorten sleep onset latency (SOL) and improve sleep quality. A total of 11 young healthy/normal sleeper males challenged to go to bed (lights-off) 2 h earlier than usual were subjected in a randomised order to non-consecutive treatment and control night-time sleep sessions. The treatment night entailed activation of a dual-temperature zone mattress with a cooler centre and warmer periphery plus STS pillow that applied mild heating to the cervical spinal skin for 30 min after lights-off for sleep. During the first 30 min after lights-off, GSBF (mean [standard error (SE)] Δ=49.77[19.13]perfusion units, p=0.013) and DPG (mean [SE] Δ=2.05[0.62]°C, p= 0.005) were significantly higher and CBT (mean [SE] Δ=-0.15[0.07]°C, p=0.029) was significantly lower in the treatment than control night, while there was no significant difference in these variables during the 45 min prior to lights-off (baseline). Moreover, SOL was significantly reduced (mean [SE] Δ=-48.6[23.4]min, p=0.032) and subjective sleep quality significantly better (p < 0.001) in the treatment than control night. In conclusion, the novel sleep facilitating system comprised of the STS pillow plus dual-temperature zone mattress induced earlier increase in GSBF and DPG and earlier decline in CBT. This resulted in statistically significant shortened SOL and improved overall sleep quality, thereby reducing sleep pressure of Process S, even under the challenging investigative protocol requiring participants to go to sleep 2 h earlier than customary.

0203 Rise and shine! The efficacy of a multimodal environmental alarm system on mitigating the effects of sleep inertia

Abstract 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 &amp;lt; 0.005) and fewer lapses (p = 0.002). Conversely, moderate evening-types who experienced a longer light exposure (&amp;gt;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)

A quiet place: The impact of the word "quiet" on clinical workload.

This study aimed to determine the impact of uttering the word "quiet" on clinical workload during the overnight otolaryngology call shift and understand the factors contributing to resident busyness. A multicenter, single-blind, randomized-controlled trial was conducted. A total of 80 overnight call shifts covered by a pool of 10 residents were randomized to the quiet or to the control group. At the start of shift, residents were asked to state aloud, "Today will be a quiet night" (quiet group) or "Today will be a good night" (control group). Clinical workload, as measured by number of consults, was the primary outcome. Secondary measures included number of sign-out tasks, unplanned inpatient and operating room visits, number of phone calls and hours of sleep, and self-perceived busyness. There was no difference in the number of total (P = 0.23), nonurgent (P = 0.18), and urgent (P = 0.18) consults. Tasks at signout, total phone calls, unplanned inpatient visits, and unplanned operating room visits did not differ between the control and quiet groups. While there were more unplanned operating room visits in the quiet group (29, 80.6%) compared to the control group (34, 94.4%), this was not found to be significant (P = 0.07). The majority of residents reported feeling "not busy" during control nights (18, 50.0%) compared to feeling "somewhat busy" during quiet nights (17, 47.2%; P = 0.42). Contrary to popular belief, there is no clear evidence that uttering the word "quiet" significantly increases clinical workload.

Settling in: space utilization behaviour of translocated Hazel Dormice (Muscardinus avellanarius)

The Hazel Dormouse (Muscardinus avellanarius) is protected under the EU’s Habitat Directive and its national implementation, whereby physical harm to individuals as well as the destruction of breeding and nesting sites is prohibited. Within the context of inevitable environmental impacts these protection goals are not always maintained. Therefore, mitigation and compensation measures to secure a population’s viability are required. For sedentary and less mobile species like the Hazel Dormouse, mitigation often includes the translocation of individuals to a different habitat patch. In 2017 and 2018 a total of 108 individuals were translocated from an old growth oak-hornbeam forest to an area that was re-forested 40 years ago. Prior to translocation, individuals were equipped with a radio transmitter and they were followed for three consecutive nights and one control night, during which bearings were taken every five minutes using the triangulation technique. A control group of established Hazel Dormice was followed in the same manner. Nests and resting sites were searched for during the daytime. Twelve male Hazel Dormice were radio-collared and between 234 and 427 bearings were taken per individual. Resting sites of translocated dormice were mainly located within the forest canopy (33.3%). Furthermore, individuals were often found active during the daytime. Mean activity range size (MCP) and resource search areas (LoCoH 95 %) were larger in translocated dormice, whereas the mean core habitat size (LoCoH 50 %) was larger in established dormice. The activity range during all of the monitored nights overlapped significantly more in established dormice, demonstrating exploratory behaviour by translocated individuals.

An experimental investigation on the impact of wind turbine noise on polysomnography-measured and sleep diary-determined sleep outcomes.

Carefully controlled studies of wind turbine noise (WTN) and sleep are lacking, despite anecdotal complaints from some residents in wind farm areas and known detrimental effects of other noises on sleep. This laboratory-based study investigated the impact of overnight WTN exposure on objective and self-reported sleep outcomes. Sixty-eight participants (38 females) aged (mean ± SD) 49.2 ± 19.5 were recruited from four groups; N = 14, living <10 km from a wind farm and reporting WTN related sleep disruption; N = 18, living <10 km from a wind farm and reporting no WTN sleep disruption; N = 18, reporting road traffic noise-related sleep disruption; and N = 18 control participants living in a quiet rural area. All participants underwent in-laboratory polysomnography during four full-night noise exposure conditions in random order: a quiet control night (19 dB(A) background laboratory noise), continuous WTN (25 dB(A)) throughout the night; WTN (25 dB(A)) only during periods of established sleep; and WTN (25 dB(A)) only during periods of wake or light N1 sleep. Group, noise condition, and interaction effects on measures of sleep quantity and quality were examined via linear mixed model analyses. There were no significant noise condition or group-by-noise condition interaction effects on polysomnographic or sleep diary determined sleep outcomes (all ps > .05). These results do not support that WTN at 25 dB(A) impacts sleep outcomes in participants with or without prior WTN exposure or self-reported habitual noise-related sleep disruption. These findings do not rule out effects at higher noise exposure levels or potential effects of WTN on more sensitive markers of sleep disruption. ACTRN12619000501145, UTN U1111-1229-6126. Establishing the physiological and sleep disruption characteristics of noise disturbances in sleep. https://www.anzctr.org.au/. This study was prospectively registered on the Australian and New Zealand Clinical Trial Registry.

Physical clutter affects the use of artificial ponds by the Lesser Bulldog Bat Noctilio albiventris (Chiroptera: Noctilionidae)

Bats frequently feed over water bodies, but the net value of the water bodies depends on characteristics such as the amount of physical clutter the water body has. More physical clutter may reduce the detection of prey by bats and may also increase energetic costs by increasing in the number of obstacles to avoid. Consequently, we hypothesized that increasing physical clutter affected the use of an artificial pond where the Lesser Bulldog Bat Noctilio albiventris, a Neotropical fishing bat, forages regularly over water. We experimentally tested this idea recording the number of passes and feeding buzzes emitted by the bats on different nights when we added two levels of obstacles over the water and on control nights with no obstacles. We only found differences between the treatment with the highest obstacle density and the control; there were fewer passes and less feeding buzzes with more obstacles. Therefore, the addition of obstacles did affect the foraging behavior of N. albiventris. Furthermore, we suggest that increasing physical clutter, as in our experiments, may be a cost-effective way to reduce conflicts between local fisher farmers and fishing bats in Neotropical rural areas.

Livestock guardian dog protection of free-range poultry from the red fox

Context Predation of layer chickens is a major issue for free-range egg producers. Using livestock guardian dogs (LGD) to protect free-ranging poultry is a possible option for producers, although there is little published literature regarding how the dogs protect chickens. Aims This case study was conducted at a free-range egg production farm in Western Australia, where red foxes (Vulpes vulpes) were a common predator of chickens prior to introducing Maremma LGD. We investigated LGD responses to experimental cues that might indicate fox incursion (fox urine and calls). Methods Four dogs were GPS tracked and monitored using camera traps. Over the first week, experimental fox cues were set out around the paddock boundaries, alternating with ‘non-cue’ experimental control nights. We recorded whether the LGD altered (1) their space use, (2) activity patterns (movement speed), or (3) behaviour in response to these cues. We also recorded (4) distances between LGD from known sightings of foxes. Key results The Maremmas appeared to work independently of each other, covering separate areas. There was no significant difference in overnight home range area by experimental fox cue treatment, but there was a significant (P &lt; 0.001) treatment × dog interaction term for distance moved. Three dogs spent most of their time at night around the chicken shelters and generally increased distances moved on experimental fox cue nights. The fourth dog was more bonded to people and did not alter its movements. Paradoxically, dogs rested more and barked less on experimental fox cue nights; however, we recorded foxes on camera traps placed around the chicken shelters on 17 of the 23 nights of monitoring, and the high background activity level of foxes on this property compromised our experimental control (nights without experimental fox cues). The dogs did not move towards known fox sightings. Conclusions The Maremmas in this trial closely guarded the chicken shelters rather than maintaining the entire paddock as a predator-exclusion zone. Implications Understanding how guardian dogs behave when challenged by potential predators will help increase producers’ confidence in the efficacy of these dogs as a viable method to protect livestock from predation threat.

The effect of wind turbine noise on polysomnographically measured and self-reported sleep latency in wind turbine noise naïve participants.

Wind turbine noise (WTN) exposure could potentially interfere with the initiation of sleep. However, effects on objectively assessed sleep latency are largely unknown. This study sought to assess the impact of WTN on polysomnographically measured and sleep diary-determined sleep latency compared to control background noise alone in healthy good sleepers without habitual prior WTN exposure. Twenty-three WTN naïve urban residents (mean ± SD age: 21.7 ± 2.1 years, range 18-29, 13 females) attended the sleep laboratory for two polysomnography studies, one week apart. Participants were blind to noise conditions and only informed that they may or may not hear noise during each night. During the sleep onset period, participants were exposed to counterbalanced nights of WTN at 33 dB(A), the upper end of expected indoor values; or background noise alone as the control condition (23 dB(A)). Linear mixed model analysis revealed no differences in log10 normalized objective or subjective sleep latency between the WTN versus control nights (median [interquartile range] objective 16.5 [11.0 to 18.5] vs. 16.5 [10.5 to 29.0] min, p = .401; subjective 20.0 [15.0 to 25.0] vs. 15.0 [10.0 to 30.0] min, p = .907). Although undetected small effects cannot be ruled out, these results do not support that WTN extends sleep latency in young urban-dwelling individuals without prior WTN exposure.

O003 The impact of wind farm noise in a laboratory setting on objective and subjective sleep efficiency

Abstract Introduction Well-controlled studies of wind farm noise (WFN) on sleep are lacking despite complaints and known effects of other noise types on sleep. This laboratory-based study investigated the impact of continuous full-night WFN exposure replicated from field recordings on polysomnography-measured (objective) and sleep diary-determined (subjective) sleep efficiency compared to a quiet control night. Methods Based on residential location and self-report data, 50 participants were categorised into three groups (14 living &amp;lt;10km from a wind farm and self-reporting sleep disturbance; 19 living &amp;lt;10km from a wind farm and self-reporting no sleep disturbance and 18 controls living in a quiet rural area). Participants underwent full in-laboratory polysomnography during exposure to continuous WFN (25 dB(A)) throughout the night and a quiet control night (background noise 19 dB(A)) in random order. Group and noise condition effects were examined via linear mixed model analysis. Results Participants (30 females) were aged (mean±SD) 54.9±17.6 range: 18–80 years. Sleep efficiency in the control condition was (median [interquartile range]) objective: 85.5 [77.4 to 91.2]%; subjective: 85.7 [69.2 to 92.7]%) versus the WFN condition (objective: 86.1 [78.6 to 91.7]% subjective: 85.8 [66.2 to 93.8]%) with no significant main or interaction effects of group or noise condition (all p’s &amp;gt;0.05). Conclusion These results do not support that WFN at 25 dB(A) significantly impacts objective or subjective sleep efficiency in participants with or without prior WFN exposure or self-reported WFN-related sleep disturbance. Further analyses to investigate potential sleep micro-structural changes remain warranted.