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Barbara Griefahn

Bio: Barbara Griefahn is an academic researcher from Technical University of Dortmund. The author has contributed to research in topics: Noise & Annoyance. The author has an hindex of 30, co-authored 118 publications receiving 3307 citations.


Papers
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Journal ArticleDOI
TL;DR: An interdisciplinary field study examining the annoyance by rail and road traffic noise with special regard to sleep disturbance was carried out, and the noise induced responses were determined by questionnaires and physiological measurement of sleep disturbance.
Abstract: An interdisciplinary field study examining the annoyance by rail and road traffic noise with special regard to sleep disturbance was carried out. The noise induced responses were determined by questionnaires and physiological measurement of sleep disturbance. For subjects taking part in the physiological examination, acoustical measurements have been taken inside and outside the bedroom. The individual noise levels for all subjects have been calculated using the German standards RLS90 and Schall03. As input variables (such as number and speed of passing trains or vehicles) for these calculations on one hand measured data and on the other hand official data have been used. Whereas the measured data deliver reliable information about the traffic during the physiological measurements, the official data mostly refer to maximum (e.g., speed) or average values. Furthermore, the noise levels have been calculated for different measurement points. Thus, together with the measured noise levels a variety of subject ...

1 citations

Journal ArticleDOI
TL;DR: In this paper, the effects of sonic booms on sleep were investigated in two experimental series (19 resp. 53 nights, 2 different persons in each series, test-time 10.30 p.m. to 3.00 a.m.).
Abstract: In two experimental series (19 resp. 53 nights, 2 different persons in each series, test-time 10.30 p.m. to 3.00 a.m.) pulse rate after sonic booms had been recorded during sleep. In the first 3 nights the subjects slept undisturbed by noise. In the following 11 resp. 30 nights sonic booms were applied alternately 2 or 4 times. In the main series after 10 more nights without any noise 4 nights with 8 and 16 sonic booms alternately followed. The last 6 undisturbed nights in both series were used as comparison phase. The interval between two sonic booms was 40 min in nights with 2 booms, 20 min in nights with 4 sonic booms and in the nights with 8 and 16 sonic booms 8.6 resp. 4.6 min. Sound level of the sonic booms ranged from 0.48 mbar to 1.45 mbar, 1 mbar [83.5 dB (A)] in the average. The first sonic boom was applied if one of the two subjects had entered the deepest stage of sleep. Sonic booms induced a biphasic reaction in pulse rate. After an initial increase in frequency with a maximum in the 4th sec pulse rate decreased below the value before sonic boom; it was followed by a slow increase towards the baseline value. This reaction was analysed with special regard to the following factors: 1. Intensity. Due to very fast increase of noise intensity there was no significant correlation between the intensity of sonic boom and the pulse reaction. 2. Exogenic variables. There is no significant connection between postboom pulse rate and noiseless time before the sonic boom, the duration of the test series and the ambient temperature. 3. Endogenic variables. No correlation could be found between the stage of sleep and the reaction. On the contrary a very significant correlation was found between the maximum of postboom increase of pulse rate and the pulse rate before boom. With increasing pulse rate the extent of reaction becomes smaller.

1 citations

Journal ArticleDOI
TL;DR: In this article, a nonlinear two-stage model was applied to the increase of human core temperature for a set of 678 experiments where the subjects were exposed to warm and hot environments.
Abstract: In the context of medical or biological studies, very often parameters of interest are measured repeatedly over time under a given set of conditions. This results in a set of (often similarly shaped) time series. Then, the objective is the determination of the functional relationship between the parameter of interest and time on the one hand, and the analysis of the variation of this functional relationship between experiments, on the other hand. This may be done by means of a two-stage model. The present work describes the theory of the two-stage model and its application to the increase of human core temperature for a set of 678 experiments where the subjects were exposed to warm and hot environments. The data originating from 6 European research institutes, have been pooled into one database for the Heat Stress Project within the scope of the BIOMED 2 programme of the European Union. A nonlinear two-stage model was applied, with a logistic function modelling the nonlinear time course of the core temperature, and with its parameters depending on air temperature, mean radiant temperature, air velocity, partial vapour pressure, clothing insulation, metabolic rate, gender, acclimatisation status and body surface area. We conclude that acclimatisation, clothing insulation, body surface area, air temperature, air velocity, partial vapour pressure, metabolic rate, and the difference between mean radiant temperature and air temperature play an important role for work in warm and hot environments. We show how our results can be used for the estimation of allowable exposure times for work in hot environments.

1 citations

01 Jan 1997
TL;DR: In this paper, it was proved that whole body vibrations transmitted through the seat impair spatial retinal resolution and oculomotor alignment parallel to the vibration axis, which may lead to the development of asthenopic complaints.
Abstract: The hypothesis was proved that whole body vibrations transmitted through the seat impair spatial retinal resolution and oculomotor alignment parallel to the vibration axis. More specifically, it was assumed that the decrement increases gradually from single-axis lateral via single-axis vertical and dual-axis linear to dual-axis circular motions. 20 subjects (19-26 yrs, 14 men, 6 women) with good vision participated in the study where in separate experimental sessions either fixation disparity or contrast threshold for vertically and horizontally oriented test patterns were determined during 5 conditions. The latter comprized a control (az = aY= O) and 4 conditions where 5 Hz sinusoidal vibrations of 1.2 ins-2 r.m.s. were applied separately, either in the vertical or in the lateral direction or simultaneously in both directions, once without and once with a phase shift of 90° thus causing dualaxis linear or circular motions. The variability of vertical fixation disparity and contrast thresholds for horizontal gratings increased significantly whenever the subjects were exposed to vertical motions (alone or combined with lateral motions). These results indicate an increased difficulty to recognize properly characters and graphic patterns that contain horizontal lines. This may lead to the development of asthenopic complaints.

1 citations


Cited by
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Journal ArticleDOI
TL;DR: The importance of adequate noise prevention and mitigation strategies for public health is stressed, as Observational and experimental studies have shown that noise exposure leads to annoyance, disturbs sleep and causes daytime sleepiness.

1,189 citations

01 Jan 2013
TL;DR: In this paper, the authors stress the importance of adequate noise prevention and mitigation strategies for public health and stress that noise exposure leads to annoyance, disturbs sleep and causes daytime sleepiness, aff ects patient outcomes and staff performance in hospitals, increases the occurrence of hypertension and cardiovascular disease, and impairs cognitive performance in schoolchildren.
Abstract: Noise is pervasive in everyday life and can cause both auditory and non-auditory health eff ects. Noise-induced hearing loss remains highly prevalent in occupational settings, and is increasingly caused by social noise exposure (eg, through personal music players). Our understanding of molecular mechanisms involved in noise-induced haircell and nerve damage has substantially increased, and preventive and therapeutic drugs will probably become available within 10 years. Evidence of the non-auditory eff ects of environmental noise exposure on public health is growing. Observational and experimental studies have shown that noise exposure leads to annoyance, disturbs sleep and causes daytime sleepiness, aff ects patient outcomes and staff performance in hospitals, increases the occurrence of hypertension and cardiovascular disease, and impairs cognitive performance in schoolchildren. In this Review, we stress the importance of adequate noise prevention and mitigation strategies for public health.

942 citations

Journal ArticleDOI
TL;DR: This review of the psychometric properties and validity of CT measures as well as individual, environmental and genetic factors that influence the circadian typology provides a state of the art discussion to allow professionals to integrate chronobiological aspects of human behavior into their daily practice.
Abstract: The interest in the systematic study of the circadian typology (CT) is relatively recent and has developed rapidly in the two last decades. All the existing data suggest that this individual difference affects our biological and psychological functioning, not only in health, but also in disease. In the present study, we review the current literature concerning the psychometric properties and validity of CT measures as well as individual, environmental and genetic factors that influence the CT. We present a brief overview of the biological markers that are used to define differences between CT groups (sleep-wake cycle, body temperature, cortisol and melatonin), and we assess the implications for CT and adjustment to shiftwork and jet lag. We also review the differences between CT in terms of cognitive abilities, personality traits and the incidence of psychiatric disorders. When necessary, we have emphasized the methodological limitations that exist today and suggested some future avenues of work in order to overcome these. This is a new field of interest to professionals in many different areas (research, labor, academic and clinical), and this review provides a state of the art discussion to allow professionals to integrate chronobiological aspects of human behavior into their daily practice.

936 citations

Journal ArticleDOI
TL;DR: It is proposed that brain disorders and abnormal sleep have a common mechanistic origin and that many co-morbid pathologies that are found in brain disease arise from a destabilization of sleep mechanisms.
Abstract: Sleep and circadian rhythm disruption are frequently observed in patients with psychiatric disorders and neurodegenerative disease. The abnormal sleep that is experienced by these patients is largely assumed to be the product of medication or some other influence that is not well defined. However, normal brain function and the generation of sleep are linked by common neurotransmitter systems and regulatory pathways. Disruption of sleep alters sleep-wake timing, destabilizes physiology and promotes a range of pathologies (from cognitive to metabolic defects) that are rarely considered to be associated with abnormal sleep. We propose that brain disorders and abnormal sleep have a common mechanistic origin and that many co-morbid pathologies that are found in brain disease arise from a destabilization of sleep mechanisms. The stabilization of sleep may be a means by which to reduce the symptoms of--and permit early intervention of--psychiatric and neurodegenerative disease.

864 citations

Journal ArticleDOI
TL;DR: Melatonin is principally secreted at night and is centrally involved in sleep regulation, as well as in a number of other cyclical bodily activities, and its sleep-facilitating properties have been found to be useful for treating insomnia symptoms in elderly and depressive patients.
Abstract: Melatonin is a ubiquitous molecule and widely distributed in nature, with functional activity occurring in unicellular organisms, plants, fungi and animals. In most vertebrates, including humans, melatonin is synthesized primarily in the pineal gland and is regulated by the environmental light/dark cycle via the suprachiasmatic nucleus. Pinealocytes function as 'neuroendocrine transducers' to secrete melatonin during the dark phase of the light/dark cycle and, consequently, melatonin is often called the 'hormone of darkness'. Melatonin is principally secreted at night and is centrally involved in sleep regulation, as well as in a number of other cyclical bodily activities. Melatonin is exclusively involved in signaling the 'time of day' and 'time of year' (hence considered to help both clock and calendar functions) to all tissues and is thus considered to be the body's chronological pacemaker or 'Zeitgeber'. Synthesis of melatonin also occurs in other areas of the body, including the retina, the gastrointestinal tract, skin, bone marrow and in lymphocytes, from which it may influence other physiological functions through paracrine signaling. Melatonin has also been extracted from the seeds and leaves of a number of plants and its concentration in some of this material is several orders of magnitude higher than its night-time plasma value in humans. Melatonin participates in diverse physiological functions. In addition to its timekeeping functions, melatonin is an effective antioxidant which scavenges free radicals and up-regulates several antioxidant enzymes. It also has a strong antiapoptotic signaling function, an effect which it exerts even during ischemia. Melatonin's cytoprotective properties have practical implications in the treatment of neurodegenerative diseases. Melatonin also has immune-enhancing and oncostatic properties. Its 'chronobiotic' properties have been shown to have value in treating various circadian rhythm sleep disorders, such as jet lag or shift-work sleep disorder. Melatonin acting as an 'internal sleep facilitator' promotes sleep, and melatonin's sleep-facilitating properties have been found to be useful for treating insomnia symptoms in elderly and depressive patients. A recently introduced melatonin analog, agomelatine, is also efficient for the treatment of major depressive disorder and bipolar affective disorder. Melatonin's role as a 'photoperiodic molecule' in seasonal reproduction has been established in photoperiodic species, although its regulatory influence in humans remains under investigation. Taken together, this evidence implicates melatonin in a broad range of effects with a significant regulatory influence over many of the body's physiological functions.

842 citations