Nocturnal air, road, and rail traffic noise and daytime cognitive performance and annoyance

Various studies indicate that at the same noise level and during the daytime, annoyance increases in the order of rail, road, and aircraft noise. The present study investigates if the same ranking can be found for annoyance to nocturnal exposure and next day cognitive performance. Annoyance ratings and performance change during combined noise exposure were also tested. In the laboratory 72 participants were exposed to air, road, or rail traffic noise and all combinations. The number of noise events and LAS,eq were kept constant. Each morning noise annoyance questionnaires and performance tasks were administered. Aircraft noise annoyance ranked first followed by railway and road noise. A possible explanation is the longer duration of aircraft noise events used in this study compared to road and railway noise events. In contrast to road and rail traffic, aircraft noise annoyance was higher after nights with combined exposure. Pooled noise exposure data showed small but significant impairments in reaction times (6 ms) compared to nights without noise. The noise sources did not have a differential impact on performance. Combined exposure to multiple traffic noise sources did not induce stronger impairments than a single noise source. This was reflected also in low workload ratings

Auralization of Amplitude Modulated Helicopter Flyover Noise

Rotorcraft noise is an active field of study as the sound produced by these vehicles is often found to be annoying. A means to auralize rotorcraft flyover noise is sought to help understand the factors leading to annoyance. Previous work by the authors auralized a complete flyover event in which the source noise synthesis traversed a range of emission angles. The source noise definition process for the synthesis used helicopter flyover recordings. Although this process yielded both periodic and aperiodic (modulation) components at a set of discrete emission angles, only the periodic components were used in the previous work to synthesize the sound of the flyover event. In the current work, aperiodic amplitude modulation is incorporated into the source noise synthesis to improve its fidelity toward assessing rotorcraft noise annoyance. The method is demonstrated using ground recordings from a flight test of the AS350 helicopter for the source noise definition

Determining physiological reaction probabilities to noise events during sleep

Some of the activations that occur during sleep, e.g. awakening reactions, can be considered adverse effects of noise events (e.g., airplane overflights or train passings) during the night. The occurrence of such reactions is an important indicator of the sleep disturbing potential of the particular noise stimulus and it is often desired to exactly quantify that potential in terms of a probability. Awakenings are considered the strongest form of reaction to noise stimuli during sleep and are one of the most often adopted criteria in night time noise protection concepts. However, the correct determination of noise induced awakening probability has given rise to debate in the scientific community in recent years. Because during every night's sleep, spontaneous awakenings can occur at any time, it remains unknown in principle, whether a particular awakening observed during the presence of a noise stimulus was induced by that stimulus or emerged spontaneously. Nevertheless, correctly determining the awakening probability in question is key when it comes to forecasting noise effects during the night. This article introduces two definitions of reaction probability, discusses their advantages and disadvantages, and develops a model of the influence of the time window duration in which reactions of sleepers are screened on the calculated reaction probabilit

Impact of long-term daylight deprivation on retinal light sensitivity, circadian rhythms and sleep during the Antarctic winter.

Long-term daylight deprivation such as during the Antarctic winter has been shown to lead to delayed sleep timing and sleep fragmentation. We aimed at testing whether retinal sensitivity, sleep and circadian rest-activity will change during long-term daylight deprivation on two Antarctic bases (Concordia and Halley VI) in a total of 25 healthy crew members (mean age: 34 ± 11y; 7f). The pupil responses to different light stimuli were used to assess retinal sensitivity changes. Rest-activity cycles were continuously monitored by activity watches. Overall, our data showed increased pupil responses under scotopic (mainly rod-dependent), photopic (mainly L-/M-cone dependent) as well as bright-blue light (mainly melanopsin-dependent) conditions during the time without direct sunlight. Circadian rhythm analysis revealed a significant decay of intra-daily stability, indicating more fragmented rest-activity rhythms during the dark period. Sleep and wake times (as assessed from rest-activity recordings) were significantly delayed after the first month without sunlight (p < 0.05). Our results suggest that during long-term daylight deprivation, retinal sensitivity to blue light increases, whereas circadian rhythm stability decreases and sleep-wake timing is delayed

Inflight Pharmacokinetic and Pharmacodynamic Responses to Medications Commonly Used in Spaceflight

Researchers do not know if medications act the same in the spaceflight environment as they do on Earth. Aspects of the spaceflight environment (low gravity, radiation exposure, closed environment, stress) have been shown to alter human physiology. Some of these physiological changes could be expected to alter either pharmacokinetics (PK, how the body absorbs, distributes, metabolizes and excretes administered medications) or pharmacodynamics (PD, receptors or signaling systems that are the targets of medication action). Anecdotal data has suggested that, at least for certain medications or indications, inflight medication efficacy is poor. In order to prepare for exploration missions where speedy evacuation to Earth may not be a possibility, the likelihood of unexpected medication action must be determined

Introducing a Specific Term to Present Caries Experience in Populations with Low Caries Prevalence: Specific Affected Caries Index (SaC)

Up to now, indices like the mean dmft/DMFT and the SiC (Significant Caries Index) have been used to depict caries experience in populations with high prevalence. With the caries decline, particularly for populations with low caries levels, these indices reach their statistical limits. This paper aims to introduce a specific term, the Specific affected Caries Index (SaC) for the risk groups in populations with low caries prevalence and to illustrate its use based on the consecutive German National Oral Health Survey (GNOHS) in children. In groups with a caries prevalence less than one-third of the population, many caries-free children (DMFT = 0) are included in the SiC (risk group), which calls for a new way of illustration. Mean caries experience (DMFT), caries prevalence, the SiC and SaC were portrayed for 12-year-olds in the GNOHS from 1994/95 to 2016. The SaC describes the mean caries experience (DMFT) in the group presenting caries experience (DMFT > 0). In 12-year-old 6th graders in Germany, the mean caries experience decreased from 2.4 (1994/95) to 0.4 DMFT (2016), with a recent prevalence of 21.2% (DMFT > 0, 2016). In 2016, the mean number of affected teeth in children with DMFT > 0 (SaC) was 2.1, while the SiC including 12% DMFT-free children in the risk group was 1.3. The SiC fails to reflect the caries severity in children in a population with low caries prevalence. Therefore, the newly introduced term Specific affected Caries Index (SaC) may be used to describe accurately caries experience in caries risk children in populations presenting low caries prevalence

Effects of Acute Exposures to Carbon Dioxide Upon Cognitive Functions

Large quantities of carbon dioxide (CO2) originate from human metabolism and typically, within spacecraft, remain about 10-fold higher in concentration than at the earth's surface. There have been recurring complaints by crew members of episodes of "mental viscosity" adversely affecting their performance, and there is evidence from the International Space Station (ISS) that associates CO2 levels with reports of headaches by crewmembers. Additionally, there is concern that CO2 may contribute to vision impairment and intracranial pressure that has been observed in some crewmembers. Consequently, flight rules have been employed to control the level of CO2 below 4 mm Hg, which is well below the existing Spacecraft Maximum Allowable Concentration (SMAC) of 10 mm Hg for 24-hour exposures, and 5.3 mm Hg for exposures of 7 to 180 days. However, the flight rule imposed limit, which places additional demands upon resources and current technology, still exceeds the lower bound of the threshold range for reportable headaches (2 - 5 mm Hg). Headaches, while sometime debilitating themselves, are also symptoms that can provide evidence that physiological defense mechanisms have been breached. The causes of the headaches may elicit other subtle adverse effects that occur at CO2 levels well below that for headaches. The concern that CO2 may have effects at levels below the threshold for headaches appears to be substantiated in unexpected findings that CO2 at concentrations below 2 mm Hg substantially reduced some cognitive functions that are associated with the ability to make complex decisions in conditions that are characterized by volatility, uncertainty, complexity, ambiguity, and delayed feedback. These are conditions that could be encountered by crews in off-nominal situations or during the first missions beyond low earth orbit. If findings of the earlier study are confirmed in crew-like subjects, our findings would provide additional evidence that CO2 may need to be controlled at levels that are well below current spacecraft limits. Our study will extend the earlier study to determine if crew-like subjects are similarly effected by CO2. In addition to employing the Strategic Management Simulation tool, we will use the Cognition battery of psychometric measures that are being utilized aboard the ISS. It will be important to learn, by using Cognition, if additional cognitive domains are sensitive to concentrations of CO2 at or below limits currently controlled by flight rules. While spaceflight Cognition data will greatly enhance the knowledge base related to inflight behavioral health and performance, some of the measures may be influenced by fatigue (related to sleep deprivation and or workload) and changes in circadian rhythms. Therefore our use of this battery of tests in a well-controlled, ground-based study that is free of these potential confounding influences will establish a baseline terrestrial data set against which Cognition data collected in flight may be assessed. The findings from this study will be useful to the NASA Toxicology Office and the National Research Council Committee on Toxicology, which assists NASA in setting environmental standards, for revision of the SMAC for CO2, and for designing further studies on effects of CO2 upon cognitive functions

Experimental and computational characterization of a modified GEC cell for dusty plasma experiments

A self-consistent fluid model developed for simulations of micro- gravity dusty plasma experiments has for the first time been used to model asymmetric dusty plasma experiments in a modified GEC reference cell with gravity. The numerical results are directly compared with experimental data and the experimentally determined dependence of global discharge parameters on the applied driving potential and neutral gas pressure is found to be well matched by the model. The local profiles important for dust particle transport are studied and compared with experimentally determined profiles. The radial forces in the midplane are presented for the different discharge settings. The differences between the results obtained in the modified GEC cell and the results first reported for the original GEC reference cell are pointed out

Sleep During Pregnancy: The nuMoM2b Pregnancy and Sleep Duration and Continuity Study

Study Objectives: To characterize sleep duration, timing and continuity measures in pregnancy and their association with key demographic variables. Methods: Multisite prospective cohort study. Women enrolled in the nuMoM2b study (nulliparous women with a singleton gestation) were recruited at the second study visit (16-21 weeks of gestation) to participate in the Sleep Duration and Continuity substudy. Women <18 years of age or with pregestational diabetes or chronic hypertension were excluded from participation. Women wore a wrist activity monitor and completed a sleep log for 7 consecutive days. Time in bed, sleep duration, fragmentation index, sleep efficiency, wake after sleep onset, and sleep midpoint were averaged across valid primary sleep periods for each participant. Results: Valid data were available from 782 women with mean age of 27.3 (5.5) years. Median sleep duration was 7.4 hours. Approximately 27.9% of women had a sleep duration of 9 hours. In multivariable models including age, race/ethnicity, body mass index, insurance status, and recent smoking history, sleep duration was significantly associated with race/ethnicity and insurance status, while time in bed was only associated with insurance status. Sleep continuity measures and sleep midpoint were significantly associated with all covariates in the model, with the exception of age for fragmentation index and smoking for wake after sleep onset. Conclusions: Our results demonstrate the relationship between sleep and important demographic characteristics during pregnancy

Impact of Aerobic Fitness on Cognitive Performance During Simulated Military Operational Stress

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