Adverse effects of community noise as a public health issue

Sleep and Biological Rhythms - Too much noise disturbs sleep, as well known. The number of persons affected by community noise is estimated to be huge. This paper summarizes the recommendation by...     

On the Influence of Freight Trains on Humans: A Laboratory Investigation of the Impact of Nocturnal Low Frequency Vibration and Noise on Sleep and Heart Rate

Background

A substantial increase in transportation of goods on railway may be hindered by public fear of increased vibration and noise leading to annoyance and sleep disturbance. As the majority of freight trains run during night time, the impact upon sleep is expected to be the most serious adverse effect. The impact of nocturnal vibration on sleep is an area currently lacking in knowledge. We experimentally investigated sleep disturbance with the aim to ascertain the impact of increasing vibration amplitude.

Methodology/Principal Findings

The impacts of various amplitudes of horizontal vibrations on sleep disturbance and heart rate were investigated in a laboratory study. Cardiac accelerations were assessed using a combination of polysomnography and ECG recordings. Sleep was assessed subjectively using questionnaires. Twelve young, healthy subjects slept for six nights in the sleep laboratory, with one habituation night, one control night and four nights with a variation of vibration exposures whilst maintaining the same noise exposure. With increasing vibration amplitude, we found a decrease in latency and increase in amplitude of heart rate as well as a reduction in sleep quality and increase in sleep disturbance.

Conclusions/Significance

We concluded that nocturnal vibration has a negative impact on sleep and that the impact increases with greater vibration amplitude. Sleep disturbance has short- and long-term health consequences. Therefore, it is necessary to define levels that protect residents against sleep disruptive vibrations that may arise from night time railway freight traffic.     

Heterogeneity of sleep quality based on the Pittsburgh Sleep Quality Index in a community sample: a latent class analysis

Sleep and Biological Rhythms - This study aims to assess the latent dimensional structure of sleep quality as measured by seven components of the Pittsburgh Sleep Quality Index (PSQI) and evaluate...     

Social and environmental impacts on sleep in captive Asian elephants (Elephas maximus)

Modern zoos strive to improve standards of animal management, husbandry and welfare of their animals as part of a continual evaluation process. Elephants (Elephantidae) have received particular attention in recent years due to the challenge of providing environments which promote natural behavior and opportunities for social interaction. A number of measures have been proposed to measure wellbeing, with sleep quality increasingly being used. Sleep is a vital aspect of life for cell replenishment as well as optimal development of young. Sleep deprivation can lead to immunosuppression and illness; therefore animal managers have a responsibility to ensure they reduce the potential for disturbance through noise, light, or other environmental factors. The social environment also plays an essential role in wellbeing, particularly for species that live in multi-generational family units. In this study the nocturnal behavior of a multi-generational captive herd was observed to determine impacts of husbandry changes on sleep duration and bout length (measured as recumbent rest). As expected, average total duration of sleep was higher in younger elephants and rates were comparable to those reported in other studies of Asian elephants. Overnight access to an outdoor paddock in warmer weather increased overall average bout length of sleep in the herd. Average total duration of sleep also increased for the herd following the movement of an unrelated adult female who had previously shown weak bonds with other herd members. This indicates that social compatibility is a vital component of elephant welfare, impacting not only behavioral interactions but sleep quality and duration.     

Relationship between nutrition and sleep quality,focusing on the melatonin biosynthesis

Sleep and Biological Rhythms - Sleep duration and quality are associated with many diseases. Evaluating the relationship between nutrient intake and sleep quality is important, because dietary...     

Sleep in birds: lying on the continuum of activity and rest

Abstract

Sleep is highly organized activity which is associated with decreased muscular activity and reduced response to environmental stimuli. The sleep is regulated by both, circadian and homeostatic mechanisms. Sleep patterns can be studied by behavioral assays by observing different sleep behaviors or by neuronal activity such as EEG (electroencephalogram), EOG (electro-oculogram), and EMG (electromyogram). Sleep is organized into non-rapid eye movement (NREM) and rapid eye movement. The sleep pattern in birds are similar to that in mammals, however, few differences such as existence of unihemispheric sleep (UHS) in almost all birds compared to few marine mammals do exist. The UHS results in asymmetry of the brain function measured as slow wave activity (SWA). Several migrants exhibit sleeplessness and they compensate it by NREM. They employ UHS during their migratory flight to remain alert while sleeping and maintain the balance while flying which is advantageous for these birds. Thus, sleep is of fundamental significance for the animal as it lies on the continuum of activity and rest. The present review focuses on some of above mentioned facts about sleep in higher vertebrates particularly in birds.     

Sex differences in subjective sleep quality,sleepiness, and health-related quality of life among collegiate soccer players

Sleep and Biological Rhythms - Sleep is an important recovery phase after exercise that should be taken into account by athletes. Females are likely to be dissatisfied with their sleep quality,...     

Validation of the Pittsburgh Sleep Quality Index (PSQI) with Arabic cancer patients

Sleep and Biological Rhythms - The Pittsburgh Sleep Quality Index (PSQI), a self-administrated questionnaire, is a frequently used instrument to assess sleep quality in clinical and non-clinical...     

Lowered Insulin Signalling Ameliorates Age-Related Sleep Fragmentation in Drosophila

Sleep fragmentation, particularly reduced and interrupted night sleep, impairs the quality of life of older people. Strikingly similar declines in sleep quality are seen during ageing in laboratory animals, including the fruit fly Drosophila. We investigated whether reduced activity of the nutrient- and stress-sensing insulin/insulin-like growth factor (IIS)/TOR signalling network, which ameliorates ageing in diverse organisms, could rescue the sleep fragmentation of ageing Drosophila. Lowered IIS/TOR network activity improved sleep quality, with increased night sleep and day activity and reduced sleep fragmentation. Reduced TOR activity, even when started for the first time late in life, improved sleep quality. The effects of reduced IIS/TOR network activity on day and night phenotypes were mediated through distinct mechanisms: Day activity was induced by adipokinetic hormone, dFOXO, and enhanced octopaminergic signalling. In contrast, night sleep duration and consolidation were dependent on reduced S6K and dopaminergic signalling. Our findings highlight the importance of different IIS/TOR components as potential therapeutic targets for pharmacological treatment of age-related sleep fragmentation in humans.     

Movement disorders in sleep: Parkinson's disease and restless legs syndrome.

In recent years, sleep abnormalities have increasingly been observed in patients with movement disorders. During sleep, most patients with Parkinson's disease also exhibit the movements characteristically seen during the wake period. Movement activity during sleep may impair sleep quality and lead to daytime sleepiness and reduced quality of life. Disordered REM sleep with enhanced muscle tone is common in patients with neurodegenerative disease, and may precede the clinically evident symptoms of Parkinson's disease by years. Sleep disorders in patients with Parkinson's disease are common, and require the application of individual treatment strategies. A further frequent disorder primarily classified as a sleep disorder (dyssomnia) is the restless legs syndrome (RLS), which is closely related to the nocturnal periodic limb movement disorder and affects up to 15% of the population. The present review focuses on nocturnal motor activity and sleep in Parkinson's disease and RLS.     

The influence of subjective sleep quality on the association between eveningness and depressive symptoms

Increasing evidence suggests that eveningness is associated with increased risk for depression. Eveningness, however, is also associated with poor sleep quality and the unique role of eveningness in depressive symptomatology remains to be elucidated. The goal of the current study, therefore, was to examine the inter-relationships between eveningness, subjective sleep quality and depressive symptoms in healthy participants free of current or previous depression and sleep disorder. Here, 167 healthy participants (mean age 24.16, 129/38 females/males) completed the reduced Morningness–Eveningness Questionnaire (rMEQ), the Pittsburgh Sleep Quality Index (PSQI) and the Centre for Epidemiological Studies Depression Scale (CES-D). Bootstrap mediation analysis for a simple mediation model including rMEQ, PSQI and CES-D was applied. Eveningness was associated with increased depressive symptoms and mediation analysis showed that this relationship was partly mediated by sleep quality. Our results suggest that indicators of depression observed in evening-type individuals cannot be attributed exclusively to disturbed sleep. We suggest that interventions that target both sleep quality and dysfunctional cognitive styles would be optimal to promote well-being in evening-type individuals.     

Microphone Handling Noise: Measurements of Perceptual Threshold and Effects on Audio Quality

A psychoacoustic experiment was carried out to test the effects of microphone handling noise on perceived audio quality. Handling noise is a problem affecting both amateurs using their smartphones and cameras, as well as professionals using separate microphones and digital recorders. The noises used for the tests were measured from a variety of devices, including smartphones, laptops and handheld microphones. The signal features that characterise these noises are analysed and presented. The sounds include various types of transient, impact noises created by tapping or knocking devices, as well as more sustained sounds caused by rubbing. During the perceptual tests, listeners auditioned speech podcasts and were asked to rate the degradation of any unwanted sounds they heard. A representative design test methodology was developed that tried to encourage everyday rather than analytical listening. Signal-to-noise ratio (SNR) of the handling noise events was shown to be the best predictor of quality degradation. Other factors such as noise type or background noise in the listening environment did not significantly affect quality ratings. Podcast, microphone type and reproduction equipment were found to be significant but only to a small extent. A model allowing the prediction of degradation from the SNR is presented. The SNR threshold at which 50% of subjects noticed handling noise was found to be 4.2 ± 0.6 dBA. The results from this work are important for the understanding of our perception of impact sound and resonant noises in recordings, and will inform the future development of an automated predictor of quality for handling noise.     

Association between smartphone addiction risk,sleep quality,and sleep duration among Korean school-age children: a population-based panel study

Sleep and Biological Rhythms - Smartphone addiction is regarded as a public health threat to the lives of children and adolescents. However, its association with sleep quality and quantity is...     

Subjective effects of glycine ingestion before bedtime on sleep quality

Sleep and Biological Rhythms - The effects of glycine on sleep quality were examined in a randomized double-blinded cross-over trial. The volunteers, with complaints about the quality of their...     

Influence of Noise Correction on Intra- and Inter-Subject Variability of Quantitative Metrics in Diffusion Kurtosis Imaging

Diffusion kurtosis imaging (DKI) is a promising extension of diffusion tensor imaging, giving new insights into the white matter microstructure and providing new biomarkers. Given the rapidly increasing number of studies, DKI has a potential to establish itself as a valuable tool in brain diagnostics. However, to become a routine procedure, DKI still needs to be improved in terms of robustness, reliability, and reproducibility. As it requires acquisitions at higher diffusion weightings, results are more affected by noise than in diffusion tensor imaging. The lack of standard procedures for post-processing, especially for noise correction, might become a significant obstacle for the use of DKI in clinical routine limiting its application. We considered two noise correction schemes accounting for the noise properties of multichannel phased-array coils, in order to improve the data quality at signal-to-noise ratio (SNR) typical for DKI. The SNR dependence of estimated DKI metrics such as mean kurtosis (MK), mean diffusivity (MD) and fractional anisotropy (FA) is investigated for these noise correction approaches in Monte Carlo simulations and in in vivo human studies. The intra-subject reproducibility is investigated in a single subject study by varying the SNR level and SNR spatial distribution. Then the impact of the noise correction on inter-subject variability is evaluated in a homogeneous sample of 25 healthy volunteers. Results show a strong impact of noise correction on the MK estimate, while the estimation of FA and MD was affected to a lesser extent. Both intra- and inter-subject SNR-related variability of the MK estimate is considerably reduced after correction for the noise bias, providing more accurate and reproducible measures. In this work, we have proposed a straightforward method that improves accuracy of DKI metrics. This should contribute to standardization of DKI applications in clinical studies making valuable inferences in group analysis and longitudinal studies.     

冠心病介入术前患者睡眠质量及相关因素研究

目的:探讨冠心病介入治疗患者术前睡眠质量及其影响因素。方法:采用一般状况调查表、匹兹堡睡眠质量指数(PSQI)量表、焦虑自评量表(SAS)、抑郁自评量表(SDS)、社会支持评定量表(SSRS)对2013年7月至2014年1月在某院心内科接受介入治疗的392例冠心病患者进行问卷调查。结果:发放问卷410份,回收有效问卷392份,有效率为95.6%。392例患者中287例存在睡眠质量问题,总发生率为73.2%,PSQI总分为9.88±3.63。相关因素分析显示年龄、性别、婚姻状况、焦虑、抑郁和社会支持6项是冠心病介入治疗术前患者睡眠质量的预测因素。结论:冠心病介入治疗患者术前睡眠质量较差,并受多种因素影响。     

An expert system for fault management assistance on a space sleep experiment

The expert system, Principal Investigator-in-a-box, or [PI], was designed to assist astronauts or other operators in performing experiments outside their expertise. Currently, the software helps astronauts calibrate instruments for a Sleep and Respiration Experiment without contact with the investigator on the ground. It flew on the Space Shuttle missions STS-90 and STS-95. [PI] displays electrophysiological signals in real time, alerts astronauts via the indicator lights when a poor signal quality is detected, and advises astronauts how to restore good signal quality. Thirty subjects received training on the sleep instrumentation and the [PI] interface. A beneficial effects of [PI] and training reduced troubleshooting time. [PI] benefited subjects on the most difficult scenarios, even though its lights were not 100% accurate. Further, questionnaires showed that most subjects preferred monitoring waveforms with [PI] assistance rather than monitoring waveforms alone. This study addresses problems of complex troubleshooting and the extended time between training and execution that is common to many human operator situations on earth such as in power plant operation, and marine exploration.     

Sleep Quality during Exam Stress: The Role of Alcohol,Caffeine and Nicotine

Academic exam stress is known to compromise sleep quality and alter drug consumption in university students. Here we evaluated if sleeping problems and changes in legal drug consumption during exam stress are interrelated. We used the Pittsburgh Sleep Quality Index (PSQI) to survey sleep quality before, during, and after an academic exam period in 150 university students in a longitudinal questionnaire study. Self-reports of alcohol, caffeine, and nicotine consumption were obtained. The Perceived Stress Questionnaire (PSQ-20) was used as a measure of stress. Sleep quality and alcohol consumption significantly decreased, while perceived stress and caffeine consumption significantly increased during the exam period. No significant change in nicotine consumption was observed. In particular, students shortened their time in bed and showed symptoms of insomnia. Mixed model analysis indicated that sex, age, health status, as well as the amounts of alcohol and caffeine consumed had no significant influence on global sleep quality. The amount of nicotine consumed and perceived stress were identified as significant predictors of diminished sleep quality. Nicotine consumption had a small-to-very-small effect on sleep quality; perceived stress had a small-to-moderate effect. In conclusion, diminished sleep quality during exam periods was mainly predicted by perceived stress, while legal drug consumption played a minor role. Exam periods may pose an interesting model for the study of stress-induced sleeping problems and their mechanisms.     

The effect of short-term sleep fragmentation produced by intense auditory stimuli on the arousal response to upper airway obstruction in lambs

Upper airway obstruction is recognized to cause apnoea in newborns as well as in adults. However, very little is known about factors that influence the arousal response from sleep during upper airway obstruction in newborns. Experiments were therefore done to investigate the effect of short-term sleep fragmentation on the arousal response to upper airway obstruction in six lambs aged 8 to 14 days. Each lamb was anaesthetized and instrumented for recordings of electrocorticogram, electro-oculogram, nuchal and diaphragm electromyograms and measurements of systemic arterial blood pressure and oxygen saturation (fiberoptic catheter oximeter). A tracheostomy was done and a fenestrated tracheostomy tube placed in the trachea. Experiments were not done before the third postoperative day. During a study, a 5F balloon tipped catheter was inserted into the tube so that airflow could be obstructed by inflating the balloon. Measurements were made during 30 s control periods and during experimental periods of upper airway obstruction in at least three epochs of quiet sleep and active sleep in each animal. These measurements were made following a period of uninterrupted sleep and repeated following a 36-42 h period of sleep fragmentation. Sleep fragmentation was produced by 30 s of noise separated by 2 min of quiet. Sleep fragmentation produced small but statistically significant increases in the time to arousal and decreases in the haemoglobin oxygen saturation at arousal during upper airway obstruction in quiet sleep but not active sleep. However, these changes, although consistent, were small and are of questionable biological significance. Therefore, I believe it is unlikely that short-term sleep fragmentation per se significantly impairs the arousal response to respiratory stimuli in newborns.     

Technical Note: Quality assessment of virtual monochromatic spectral images on a dual energy CT scanner

PurposeTo assess the quality of images obtained on a dual energy computed tomography (CT) scanner.MethodsImage quality was assessed on a 64 detector-row fast kVp-switching dual energy CT scanner (Revolution GSI, GE Medical Systems). The Catphan phantom and a low contrast resolution phantom were employed. Acquisitions were performed at eight different radiation dose levels that ranged from 9 mGy to 32 mGy. Virtual monochromatic spectral images (VMI) were reconstructed in the 40–140 keV range using all available kernels and iterative reconstruction (IR) at four different blending levels. Modulation Transfer Function (MTF) curves, image noise, image contrast, noise power spectrum and contrast to noise ratio were assessed.ResultsIn-plane spatial resolution at the 10% of the MTF curve was 0.60 mm⁻¹. In-plane spatial resolution was not modified with VMI energy and IR blending level. Image noise was reduced from 16.6 at 9 mGy to 6.7 at 32 mGy, while peak frequency remained within 0.14 ± 0.01 mm⁻¹. Image noise was reduced from 14.3 at IR 10% to 11.5 at IR 50% at a constant peak frequency. The lowest image noise and maximum peak frequency were recorded at 70 keV.ConclusionsOur results have shown how objective image quality is varied when different levels of radiation dose and different settings in IR are applied. These results provide CT operators an in depth understanding of the imaging performance characteristics in dual energy CT.