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Sample records for infrasonic noise-induced stress

  1. Possible effects of rosuvastatin on noise-induced oxidative stress in rat brain

    Directory of Open Access Journals (Sweden)

    Alevtina Ersoy

    2014-01-01

    Full Text Available The problem of noise has recently gained more attention as it has become an integral part of our daily lives. However, its influence has yet to be fully elucidated. Other than being an unpleasant stimulus, noise may cause health disorders through annoyance and stress, including oxidative stress. Rosuvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, may possess antioxidant properties. Based on rat models, our project investigates the effect of rosuvastatin on noise-induced oxidative stress in the brain tissue. Thirty-two male Wistar albino rats were used. The rats were divided into four groups: Noise exposure plus rosuvastatin usage, only noise exposure, only rosuvastatin usage, and control. After the data had been collected, oxidant and antioxidant parameters were analyzed in the cerebral cortex, brain stem, and cerebellum. Results indicated that superoxide dismutase values were significantly decreased in the cerebral cortex, while malondialdehyde values in the brainstem and cerebellum were significantly increased in the group with only noise exposure. Superoxide dismutase values in the brainstem were significantly increased, but nitric oxide values in the cerebellum and brainstem and malondialdehyde values in the cerebellum and cerebral cortex were significantly decreased in the group where only rosuvastatin was used. During noise exposure, the use of rosuvastatin caused significantly increased superoxide dismutase values in the cerebral cortex and brainstem, but significantly reduced malondialdehyde values in the brain stem. Consequently, our data show that brain tissue was affected by oxidative stress due to continued exposure to noise. This noise-induced stress decreases with rosuvastatin therapy.

  2. Chronic lead exposure induces cochlear oxidative stress and potentiates noise-induced hearing loss.

    Science.gov (United States)

    Jamesdaniel, Samson; Rosati, Rita; Westrick, Judy; Ruden, Douglas M

    2018-08-01

    Acquired hearing loss is caused by complex interactions of multiple environmental risk factors, such as elevated levels of lead and noise, which are prevalent in urban communities. This study delineates the mechanism underlying lead-induced auditory dysfunction and its potential interaction with noise exposure. Young-adult C57BL/6 mice were exposed to: 1) control conditions; 2) 2 mM lead acetate in drinking water for 28 days; 3) 90 dB broadband noise 2 h/day for two weeks; and 4) both lead and noise. Blood lead levels were measured by inductively coupled plasma mass spectrometry analysis (ICP-MS) lead-induced cochlear oxidative stress signaling was assessed using targeted gene arrays, and the hearing thresholds were assessed by recording auditory brainstem responses. Chronic lead exposure downregulated cochlear Sod1, Gpx1, and Gstk1, which encode critical antioxidant enzymes, and upregulated ApoE, Hspa1a, Ercc2, Prnp, Ccl5, and Sqstm1, which are indicative of cellular apoptosis. Isolated exposure to lead or noise induced 8-12 dB and 11-25 dB shifts in hearing thresholds, respectively. Combined exposure induced 18-30 dB shifts, which was significantly higher than that observed with isolated exposures. This study suggests that chronic exposure to lead induces cochlear oxidative stress and potentiates noise-induced hearing impairment, possibly through parallel pathways. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

  3. Is rosuvastatin protective against on noise-induced oxidative stress in rat serum?

    Directory of Open Access Journals (Sweden)

    Emine Rabia Koc

    2015-01-01

    Full Text Available Noise, one of the main components of modern society, has become an important environmental problem. Noise is not only an irritating sound, but also a stress factor leading to serious health problems. In this study, we have investigated possible effects of rosuvastatin, a 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor, thought to have an antioxidant effect, on noise-induced oxidative stress in the serum of rat models. Thirty-two male Wistar albino rats were used. In order to ease their adaptation, 2 weeks before the experiment, the rats were divided into four groups (with eight rats per each group: Noise exposure plus rosuvastatin usage, only noise exposure, only rosuvastatin usage and control. After the data had been collected, oxidant (Malondialdehyde, nitric oxide [NO], protein carbonyl [PC] and antioxidant (superoxide dismutase [SOD], glutathione peroxidase [GSH-PX], catalase [CAT] parameters were analyzed in the serum. Results indicated that SOD values were found to be significantly lower, while PC values in serum were remarkably higher in the group that was exposed to only noise. GSH-Px values in serum dramatically increased in the group on which only rosuvastatin was used. During noise exposure, the use of rosuvastatin caused significantly increased CAT values, whereas it resulted in reduced PC and NO values in serum. In conclusion, our data show that noise exposure leads to oxidative stress in rat serum; however, rosuvastatin therapy decreases the oxidative stress caused by noise exposure.

  4. Noise-Induced Hearing Loss

    Science.gov (United States)

    ... Home » Health Info » Hearing, Ear Infections, and Deafness Noise-Induced Hearing Loss On this page: What is ... I find additional information about NIHL? What is noise-induced hearing loss? Every day, we experience sound ...

  5. The Role of MicroRNAs in Environmental Risk Factors, Noise-Induced Hearing Loss, and Mental Stress.

    Science.gov (United States)

    Miguel, Verónica; Cui, Julia Yue; Daimiel, Lidia; Espinosa-Díez, Cristina; Fernández-Hernando, Carlos; Kavanagh, Terrance J; Lamas, Santiago

    2018-03-20

    MicroRNAs (miRNAs) are important regulators of gene expression and define part of the epigenetic signature. Their influence on every realm of biomedicine is established and progressively increasing. The impact of environment on human health is enormous. Among environmental risk factors impinging on quality of life are those of chemical nature (toxic chemicals, heavy metals, pollutants, and pesticides) as well as those related to everyday life such as exposure to noise or mental and psychosocial stress. Recent Advances: This review elaborates on the relationship between miRNAs and these environmental risk factors. The most relevant facts underlying the role of miRNAs in the response to these environmental stressors, including redox regulatory changes and oxidative stress, are highlighted and discussed. In the cases wherein miRNA mutations are relevant for this response, the pertinent literature is also reviewed. We conclude that, even though in some cases important advances have been made regarding close correlations between specific miRNAs and biological responses to environmental risk factors, a need for prospective large-cohort studies is likely necessary to establish causative roles. Antioxid. Redox Signal. 28, 773-796.

  6. Compact Infrasonic Windscreen

    Science.gov (United States)

    Zuckerwar, Allan J.; Shams, Qamar A.; Sealey, Bradley S.; Comeaux, Toby

    2005-01-01

    A compact windscreen has been conceived for a microphone of a type used outdoors to detect atmospheric infrasound from a variety of natural and manmade sources. Wind at the microphone site contaminates received infrasonic signals (defined here as sounds having frequencies <20 Hz), because a microphone cannot distinguish between infrasonic pressures (which propagate at the speed of sound) and convective pressure fluctuations generated by wind turbulence. Hence, success in measurement of outdoor infrasound depends on effective screening of the microphone from the wind. The present compact windscreen is based on a principle: that infrasound at sufficiently large wavelength can penetrate any barrier of practical thickness. Thus, a windscreen having solid, non-porous walls can block convected pressure fluctuations from the wind while transmitting infrasonic acoustic waves. The transmission coefficient depends strongly upon the ratio between the acoustic impedance of the windscreen and that of air. Several materials have been found to have impedance ratios that render them suitable for use in constructing walls that have practical thicknesses and are capable of high transmission of infrasound. These materials (with their impedance ratios in parentheses) are polyurethane foam (222), space shuttle tile material (332), balsa (323), cedar (3,151), and pine (4,713).

  7. Study on infrasonic characteristics of coal samples in failure process under uniaxial loading

    Directory of Open Access Journals (Sweden)

    Bing Jia

    Full Text Available To study the precursory failure infrasonic characteristics of coal samples, coal rock stress loading system and infrasonic wave acquisition system were adopted, and infrasonic tests in uniaxial loading process were made for the coal samples in the studied area. Wavelet filtering, fast Fourier transform, and relative infrasonic energy methods were used to analyze the characteristics of the infrasonic waves in the loading process, including time domain characteristics, and relative energy. The analysis results demonstrated that the frequencies of the infrasonic signals in the loading process mainly distribute within 5–10 Hz, which are significantly different from noise signals. The changes of the infrasonic signals show clear periodic characters in time domain. Meanwhile, the relative energy changes of the infrasonic wave also show periodic characters, which are divided into two stages by the yield limit of coal samples, and are clear and easy to be recognized, so that they can be used as the precursory characteristics for recognizing coal sample failures. Moreover, the infrasonic waves generated by coal samples have low frequency and low attenuation, which can be collected without coupling and transmitted in long distance. This study provides an important support for the further in-situ prediction of coal rock failures. Keywords: Infrasound, Relative energy, Time-frequency analysis, Failure prediction, Identification feature

  8. Design of double capacitances infrasonic receiver

    International Nuclear Information System (INIS)

    Wang Changhai; Han Kuixia; Wang Fei

    2003-01-01

    The article introduces the theory of infrasonic generation and reception of nuclear explosion. An idea of the design of double capacitances infrasonic receiver using CPLD technology is given in it. Compare with the single capacitance infrasonic receiver, sensitivity of the improved receiver can be improved scores of times, dynamic range can be improved largely, and the whole performance gets improvement a lots

  9. Acoustic Localization with Infrasonic Signals

    Science.gov (United States)

    Threatt, Arnesha; Elbing, Brian

    2015-11-01

    Numerous geophysical and anthropogenic events emit infrasonic frequencies (<20 Hz), including volcanoes, hurricanes, wind turbines and tornadoes. These sounds, which cannot be heard by the human ear, can be detected from large distances (in excess of 100 miles) due to low frequency acoustic signals having a very low decay rate in the atmosphere. Thus infrasound could be used for long-range, passive monitoring and detection of these events. An array of microphones separated by known distances can be used to locate a given source, which is known as acoustic localization. However, acoustic localization with infrasound is particularly challenging due to contamination from other signals, sensitivity to wind noise and producing a trusted source for system development. The objective of the current work is to create an infrasonic source using a propane torch wand or a subwoofer and locate the source using multiple infrasonic microphones. This presentation will present preliminary results from various microphone configurations used to locate the source.

  10. Infrasonic Emissions From A Tornado

    Science.gov (United States)

    Petrin, Christopher; Elbing, Brian

    2017-11-01

    Tornadoes cause dozens of deaths and significant damage throughout the United States every year. Tornado-producing storm systems emit infrasound (sound at frequencies below human hearing) up to 2 hours before tornadogenesis. Weak atmospheric attenuation at these frequencies allows them to be detected hundreds of miles away. Hence, passive infrasonic monitoring may be used for long-range study of tornadogenesis. This requires characterization of infrasound during the life of a tornado and from other background sources. This is being accomplished as part of the Collaboration Leading Operational UAS Development for Meteorology and Atmospheric Physics (CLOUD-MAP) project, a multi-university collaboration focused on the development and implementation of unmanned aerial systems (UAS) and their integration with sensors for atmospheric measurement. This presentation will report findings from a fixed infrasonic microphone that has been continuously monitoring the atmosphere since September 2, 2016. Infrasound from a tornado that occurred 19 km from the microphone on May 11, 2017 will be presented as well as an overview of other infrasonic observations. This work was supported by NSF Grant 1539070.

  11. Noise-induced hearing loss

    Directory of Open Access Journals (Sweden)

    Mariola Sliwinska-Kowalska

    2012-01-01

    Full Text Available Noise-induced hearing loss (NIHL still remains a problem in developed countries, despite reduced occupational noise exposure, strict standards for hearing protection and extensive public health awareness campaigns. Therefore NIHL continues to be the focus of noise research activities. This paper summarizes progress achieved recently in our knowledge of NIHL. It includes papers published between the years 2008-2011 (in English, which were identified by a literature search of accessible medical and other relevant databases. A substantial part of this research has been concerned with the risk of NIHL in the entertainment sector, particularly in professional, orchestral musicians. There are also constant concerns regarding noise exposure and hearing risk in "hard to control" occupations, such as farming and construction work. Although occupational noise has decreased since the early 1980s, the number of young people subject to social noise exposure has tripled. If the exposure limits from the Noise at Work Regulations are applied, discotheque music, rock concerts, as well as music from personal music players are associated with the risk of hearing loss in teenagers and young adults. Several recent research studies have increased the understanding of the pathomechanisms of acoustic trauma, the genetics of NIHL, as well as possible dietary and pharmacologic otoprotection in acoustic trauma. The results of these studies are very promising and offer grounds to expect that targeted therapies might help prevent the loss of sensory hair cells and protect the hearing of noise-exposed individuals. These studies emphasize the need to launch an improved noise exposure policy for hearing protection along with developing more efficient norms of NIHL risk assessment.

  12. Treatment of Noise-Induced Hearing Loss

    National Research Council Canada - National Science Library

    d'Aldin, Gervais

    1999-01-01

    .... Guinea pigs are subjected to an acoustic trauma. The recovery of the noise-induced hearing loss is followed up to 14 days post exposure by electrocochleography and morphologic examination of the cochlea is performed...

  13. Does erythropoietin augment noise induced hearing loss?

    DEFF Research Database (Denmark)

    Frederiksen, Birgitte Lidegaard; Cayé-Thomasen, Per; Lund, Søren Peter

    2007-01-01

    Noise-induced hearing loss may result from excessive release of glutamate, nitrogen oxide and reactive oxygen species. The effects of these factors on the inner ear may potentially be prevented or reduced by erythropoietin (EPO), as indicated by previously demonstrated neuro-protective effects of...

  14. Clustering of noise-induced oscillations

    DEFF Research Database (Denmark)

    Sosnovtseva, Olga; Fomin, A I; Postnov, D E

    2001-01-01

    The subject of our study is clustering in a population of excitable systems driven by Gaussian white noise and with randomly distributed coupling strength. The cluster state is frequency-locked state in which all functional units run at the same noise-induced frequency. Cooperative dynamics...

  15. Infrasonic Stethoscope for Monitoring Physiological Processes

    Science.gov (United States)

    Shams, Qamar A. (Inventor); Zuckerwar, Allan J. (Inventor); Dimarcantonio, Albert L. (Inventor)

    2018-01-01

    An infrasonic stethoscope for monitoring physiological processes of a patient includes a microphone capable of detecting acoustic signals in the audible frequency bandwidth and in the infrasonic bandwidth (0.03 to 1000 Hertz), a body coupler attached to the body at a first opening in the microphone, a flexible tube attached to the body at a second opening in the microphone, and an earpiece attached to the flexible tube. The body coupler is capable of engagement with a patient to transmit sounds from the person, to the microphone and then to the earpiece.

  16. Noise-induced enhancement of network reciprocity in social dilemmas

    International Nuclear Information System (INIS)

    Zhang, Gui-Qing; Sun, Qi-Bo; Wang, Lin

    2013-01-01

    Highlights: • We introduce the noise-induced mechanism into the prisoner’s dilemma game. • Cooperation will be largely enhanced by introducing the noise into the calculation of fitness. • Despite the defectors prevail initially, the stressed factor still promotes the cooperation. • The mechanism studied here is helpful on different kinds of interaction networks. -- Abstract: The network reciprocity is an important dynamic rule fostering the emergence of cooperation among selfish individuals. This was reported firstly in the seminal work of Nowak and May, where individuals were arranged on the regular lattice network, and played the prisoner’s dilemma game (PDG). In the standard PDG, one often assumes that the players have perfect rationality. However, in reality, we human are far from rational agents, as we often make mistakes, and behave irrationally. Accordingly, in this work, we introduce the element of noise into the measurement of fitness, which is determined by the parameter α controlling the degree of noise. The considered noise-induced mechanism remarkably promotes the behavior of cooperation, which may be conducive to interpret the emergence of cooperation within the population

  17. Noise-Induced Riddling in Chaotic Systems

    International Nuclear Information System (INIS)

    Lai, Y.; Grebogi, C.

    1996-01-01

    Recent works have considered the situation of riddling where, when a chaotic attractor lying in an invariant subspace is transversely stable, the basin of the attractor can be riddled with holes that belong to the basin of another attractor. We show that riddling can be induced by arbitrarily small random noise even if the attractor is transversely unstable, and we obtain universal scaling laws for noise-induced riddling. Our results imply that the phenomenon of riddling can be more prevalent than expected before, as noise is practically inevitable in dynamical systems. copyright 1996 The American Physical Society

  18. Infrasonic backpulsed membrane cleaning of micro- and ...

    African Journals Online (AJOL)

    Membrane fouling is universally considered to be one of the most critical problems in the wider application of membrane filtration. In this research microfiltration and ultrafiltration membranes were fouled during a cross-flow filtration process, using yeast and alumina suspensions in a flat cell. Infrasonic backpulsing directly ...

  19. Do manatees utilize infrasonic communication or detection?

    Science.gov (United States)

    Gerstein, Edmund; Gerstein, Laura; Forsythe, Steve; Blue, Joseph

    2004-05-01

    Some researchers speculate Sirenians might utilize infrasonic communication like their distant elephant cousins; however, audiogram measurements and calibrated manatee vocalizations do not support this contention. A comprehensive series of hearing tests conducted with West Indian manatees yielded the first and most definitive audiogram for any Sirenian. The manatee hearing tests were also the first controlled underwater infrasonic psychometric tests with any marine mammal. Auditory thresholds were measured from 0.4 to 46 kHz, but detection thresholds of possible vibrotactile origin were measured as low as 0.015 kHz. Manatees have short hairs on their bodies that may be sensitive vibrotactile receptors capable of detecting particle displacement in the near field. To detect these signals the manatee rotated on axis, exposing the densest portion of hairs toward the projector. Manatees inhabit shallow water where particle motion detection may be more useful near the water's surface, where sound pressures are low due to the Lloyd mirror effect. With respect to intraspecific communication, no infrasonic spectra have been identified in hundreds of calibrated calls. Low source levels and propagation limits in shallow-water habitats suggest low-frequency manatee calls have limited utility over long distances and infrasonic communication is not an attribute shared with elephants.

  20. Study on precursory characteristics of granite failure based on infrasonic energy

    Directory of Open Access Journals (Sweden)

    Jian-ping Wei

    Full Text Available To study signal characteristics of precursory infrasound of granite failure, coal-rock stress loading device and infrasound acquisition device were adopted to perform infrasound test in uniaxial loading process for granite samples. Wavelet filtering, infrasonic energy methods were used to process and analyze the test results. The results show that the infrasonic waves caused by the failure of rock samples are mainly in the middle and low frequency. Moreover, in the loading process, the ratio of relative energy of infrasound in different frequency sections and the total relative energy of the whole low frequency section both exhibit significant regularity of stage change, which is in consistent with the compaction stage, elastic stage, plastic stage of rock deformation. Additionally, the precursory characteristics of infrasound before rock failures are prominent and easy to be recognized. Meanwhile, infrasonic wave has the advantage of low attenuation in propagation process, which grants the superiority of infrasound prediction technology. A new method of rock failure prediction based on infrasound is formed, which provides an important reference for rock damage prediction in coal mining process. Keywords: Infrasonic energy, Wavelet filtering, Precursory characteristics, Failure prediction

  1. Moderators of noise-induced cognitive change in healthy adults

    Directory of Open Access Journals (Sweden)

    Bernice AL Wright

    2016-01-01

    Full Text Available Environmental noise causes cognitive impairment, particularly in executive function and episodic memory domains, in healthy populations. However, the possible moderating influences on this relationship are less clear. This study assessed 54 healthy participants (24 men on a cognitive battery (measuring psychomotor speed, attention, executive function, working memory, and verbal learning and memory under three (quiet, urban, and social noise conditions. IQ, subjective noise sensitivity, sleep, personality, paranoia, depression, anxiety, stress, and schizotypy were assessed on a single occasion. We found significantly slower psychomotor speed (urban, reduced working memory and episodic memory (urban and social, and more cautious decision-making (executive function, urban under noise conditions. There was no effect of sex. Variance in urban noise-induced changes in psychomotor speed, attention, Trail Making B-A (executive function, and immediate recall and social noise-induced changes in verbal fluency (executive function and immediate recall were explained by a combination of baseline cognition and paranoia, noise sensitivity, sleep, or cognitive disorganization. Higher baseline cognition (but not IQ predicted greater impairment under urban and social noise for most cognitive variables. Paranoia predicted psychomotor speed, attention, and executive function impairment. Subjective noise sensitivity predicted executive function and memory impairment. Poor sleep quality predicted less memory impairment. Finally, lower levels of cognitive disorganization predicted slower psychomotor speed and greater memory impairment. The identified moderators should be considered in studies aiming to reduce the detrimental effects of occupational and residential noise. These results highlight the importance of studying noise effects in clinical populations characterized by high levels of the paranoia, sleep disturbances, noise sensitivity, and cognitive

  2. Moderators of noise-induced cognitive change in healthy adults.

    Science.gov (United States)

    Wright, Bernice Al; Peters, Emmanuelle R; Ettinger, Ulrich; Kuipers, Elizabeth; Kumari, Veena

    2016-01-01

    Environmental noise causes cognitive impairment, particularly in executive function and episodic memory domains, in healthy populations. However, the possible moderating influences on this relationship are less clear. This study assessed 54 healthy participants (24 men) on a cognitive battery (measuring psychomotor speed, attention, executive function, working memory, and verbal learning and memory) under three (quiet, urban, and social) noise conditions. IQ, subjective noise sensitivity, sleep, personality, paranoia, depression, anxiety, stress, and schizotypy were assessed on a single occasion. We found significantly slower psychomotor speed (urban), reduced working memory and episodic memory (urban and social), and more cautious decision-making (executive function, urban) under noise conditions. There was no effect of sex. Variance in urban noise-induced changes in psychomotor speed, attention, Trail Making B-A (executive function), and immediate recall and social noise-induced changes in verbal fluency (executive function) and immediate recall were explained by a combination of baseline cognition and paranoia, noise sensitivity, sleep, or cognitive disorganization. Higher baseline cognition (but not IQ) predicted greater impairment under urban and social noise for most cognitive variables. Paranoia predicted psychomotor speed, attention, and executive function impairment. Subjective noise sensitivity predicted executive function and memory impairment. Poor sleep quality predicted less memory impairment. Finally, lower levels of cognitive disorganization predicted slower psychomotor speed and greater memory impairment. The identified moderators should be considered in studies aiming to reduce the detrimental effects of occupational and residential noise. These results highlight the importance of studying noise effects in clinical populations characterized by high levels of the paranoia, sleep disturbances, noise sensitivity, and cognitive disorganization.

  3. Prevention and Treatment of Noise-Induced Tinnitus

    Science.gov (United States)

    2014-09-01

    Tinnitus PRINCIPAL INVESTIGATOR: Dr. Richard A. Altschuler CONTRACTING ORGANIZATION: University of Michigan REPORT DATE: 2014...3 Ju 2014 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Prevention and Treatment of Noise-Induced Tinnitus 5b. GRANT NUMBER 5c. PROGRAM...prevent or treat noise induced tinnitus . Our studies showed a military relevant small arms fire-like noise will induce tinnitus in approximately 33

  4. Cellular mechanisms of noise-induced hearing loss.

    Science.gov (United States)

    Kurabi, Arwa; Keithley, Elizabeth M; Housley, Gary D; Ryan, Allen F; Wong, Ann C-Y

    2017-06-01

    Exposure to intense sound or noise can result in purely temporary threshold shift (TTS), or leave a residual permanent threshold shift (PTS) along with alterations in growth functions of auditory nerve output. Recent research has revealed a number of mechanisms that contribute to noise-induced hearing loss (NIHL). The principle cause of NIHL is damage to cochlear hair cells and associated synaptopathy. Contributions to TTS include reversible damage to hair cell (HC) stereocilia or synapses, while moderate TTS reflects protective purinergic hearing adaptation. PTS represents permanent damage to or loss of HCs and synapses. While the substrates of HC damage are complex, they include the accumulation of reactive oxygen species and the active stimulation of intracellular stress pathways, leading to programmed and/or necrotic cell death. Permanent damage to cochlear neurons can also contribute to the effects of NIHL, in addition to HC damage. These mechanisms have translational potential for pharmacological intervention and provide multiple opportunities to prevent HC damage or to rescue HCs and spiral ganglion neurons that have suffered injury. This paper reviews advances in our understanding of cellular mechanisms that contribute to NIHL and their potential for therapeutic manipulation. Published by Elsevier B.V.

  5. Modeling aircraft noise induced sleep disturbance

    Science.gov (United States)

    McGuire, Sarah M.

    occurrence of rapid eye movements, sleep spindles, and slow wave sleep. Using these features an approach for classifying sleep stages every one second during the night was developed. From observation of the results of the sleep stage classification, it was determined how to add faster dynamics to the nonlinear dynamic model. Slow and fast REM activity are modeled separately and the activity in the gamma frequency band of the EEG signal is used to model both spontaneous and noise-induced awakenings. The nonlinear model predicts changes in sleep structure similar to those found by other researchers and reported in the sleep literature and similar to those found in obtained survey data. To compare sleep disturbance model predictions, flight operations data from US airports were obtained and sleep disturbance in communities was predicted for different operations scenarios using the modified Markov model, the nonlinear dynamic model, and other aircraft noise awakening models. Similarities and differences in model predictions were evaluated in order to determine if the use of the developed sleep structure model leads to improved predictions of the impact of nighttime noise on communities.

  6. Studies Of Infrasonic Propagation Using Dense Seismic Networks

    Science.gov (United States)

    Hedlin, M. A.; deGroot-Hedlin, C. D.; Drob, D. P.

    2011-12-01

    Although there are approximately 100 infrasonic arrays worldwide, more than ever before, the station density is still insufficient to provide validation for detailed propagation modeling. Relatively large infrasonic signals can be observed on seismic channels due to coupling at the Earth's surface. Recent research, using data from the 70-km spaced 400-station USArray and other seismic network deployments, has shown the value of dense seismic network data for filling in the gaps between infrasonic arrays. The dense sampling of the infrasonic wavefield has allowed us to observe complete travel-time branches of infrasound and address important research problems in infrasonic propagation. We present our analysis of infrasound created by a series of rocket motor detonations that occurred at the UTTR facility in Utah in 2007. These data were well recorded by the USArray seismometers. We use the precisely located blasts to assess the utility of G2S mesoscale models and methods to synthesize infrasonic propagation. We model the travel times of the branches using a ray-based approach and the complete wavefield using a FDTD algorithm. Although results from both rays and FDTD approaches predict the travel times to within several seconds, only about 40% of signals are predicted using rays largely due to penetration of sound into shadow zones. FDTD predicts some sound penetration into the shadow zone, but the observed shadow zones, as defined by the seismic data, have considerably narrower spatial extent than either method predicts, perhaps due to un-modeled small-scale structure in the atmosphere.

  7. Preventing Noise-Induced Extinction in Discrete Population Models

    Directory of Open Access Journals (Sweden)

    Irina Bashkirtseva

    2017-01-01

    Full Text Available A problem of the analysis and prevention of noise-induced extinction in nonlinear population models is considered. For the solution of this problem, we suggest a general approach based on the stochastic sensitivity analysis. To prevent the noise-induced extinction, we construct feedback regulators which provide a low stochastic sensitivity and keep the system close to the safe equilibrium regime. For the demonstration of this approach, we apply our mathematical technique to the conceptual but quite representative Ricker-type models. A variant of the Ricker model with delay is studied along with the classic widely used one-dimensional system.

  8. Infrasonic Signals from the 29 June 2012 Derecho

    Science.gov (United States)

    Winslow, N.; Howard, W. B.; Pulli, J. J.; Kofford, A. S.

    2012-12-01

    Common weather events such as pressure fronts, tornados, and hurricanes generate infrasonic signals (sub-audible acoustic signals with an oscillatory frequency below 20 Hz). These signals can provide a distal (>10km) analysis of weather events because: (1) the attenuation of an infrasonic signal with distance is less than that of a similar audible signal, and (2) the propagation velocities of typical weather events are much slower than the speed of sound. The 29 June, 2012 Derecho (a widespread, long-lived, rapidly moving linear band of storms extending more than 240 miles and including wind gusts in excess of 58 mph) that stretched from Chicago, IL to Washington, DC generated infrasonic signals in addition to causing over $100 million in damage to the power systems of Virginia, West Virginia, and Maryland alone. The infrasonic (and seismic) signals from this event were recorded on the NCPA micro barometers along the northeastern edge of the current configuration of the USArray. These instruments, which sample at 40 Hz, exhibit a flat frequency response from around 0.1 Hz to above 20 Hz and show a sensitivity of 1.57 x 104 Volts/Pascal at 0.8 Hz. An analysis of the recordings observed at multiple stations identified several infrasonic signatures from the Derecho. The signal's duration was approximately 40 minutes and exhibited a large peak pressure fluctuation. A characteristic ramp up occurred before the peak pressure fluctuation, and the majority of the infrasonic energy occurred below 1 Hz. These signatures are analyzed within the context of the Derecho as an infrasonic source, and the propagation of infrasound in the atmosphere.

  9. Noise-induced hearing loss milestones: Past and future

    CSIR Research Space (South Africa)

    Edwards, A

    2011-01-01

    Full Text Available At the 2003 Mine Health and Safety Summit, the milestones for elimination of Noise-induced Hearing Loss (NIHL) in the mining industry were agreed on. The first milestone, December 2008, has passed and the next one in 2013 is looming. The study...

  10. Signatures of nonlinearity in single cell noise-induced oscillations

    NARCIS (Netherlands)

    Thomas, P.; Straube, A.V.; Timmer, J.; Fleck, C.; Grima, R.

    2013-01-01

    A class of theoretical models seeks to explain rhythmic single cell data by postulating that they are generated by intrinsic noise in biochemical systems whose deterministic models exhibit only damped oscillations. The main features of such noise-induced oscillations are quantified by the power

  11. Prevalence of noise induced hearing loss in textile industries in ...

    African Journals Online (AJOL)

    This cross sectional study measured the prevalence of Noise Induced Hearing Loss (NIHL) in textile industries in Dar Es Salaam city and Morogoro municipality. Data were collected from 125 employees randomly selected from each of the textile factory mill in each region through structured questionnaires and audiogram ...

  12. Prevalence and awareness of noise induced hearing loss in two ...

    African Journals Online (AJOL)

    Noise above a certain acceptable level or sustained noise may cause damage to the ears. The aim of this study is to determine the prevalence and level of awareness of noise induced hearing loss in Calabar. Seventy-five workers from two noise producing companies, in Calabar- Flour mill and Wartsilla were chosen for this ...

  13. Noise-induced chaos in a quadratically nonlinear oscillator

    International Nuclear Information System (INIS)

    Gan Chunbiao

    2006-01-01

    The present paper focuses on the noise-induced chaos in a quadratically nonlinear oscillator. Simple zero points of the stochastic Melnikov integral theoretically mean the necessary rising of noise-induced chaotic response in the system based on the stochastic Melnikov method. To quantify the noise-induced chaos, the boundary of the system's safe basin is firstly studied and it is shown to be incursively fractal when chaos arises. Three cases are considered in simulating the safe basin of the system, i.e., the system is excited only by the harmonic excitation, by both the harmonic and the Gaussian white noise excitations, and only by the Gaussian white noise excitation. Secondly, the leading Lyapunov exponent by Rosenstein's algorithm is shown to quantify the chaotic nature of the sample time series of the system. The results show that the boundary of the safe basin can also be fractal even if the system is excited only by the external Gaussian white noise. Most importantly, the almost-harmonic, the noise-induced chaotic and the thoroughly random responses can be found in the system

  14. Noise Induce Stress Assessment via Salivary Cortisol Measuring

    Directory of Open Access Journals (Sweden)

    2013-02-01

    Result: On the rest day and work day, between morning salivary cortisol was no significant difference in two groups. Comparing evening cortisol concentrations in work day with rest day a significant difference was observed, in worker group, but it was not significant in the other group. The evening cortisol in the working day in was significantly higher among workers than officers. .Conclusion: This study revealed that industrial noise exposure with levels higher than 80 dBA has a significant effect on salivary cortisol elevation.

  15. Infrasonic waves and air-conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Hoenmann, W.

    1986-08-01

    This article is a critical investigation of the recently-suggested possibility that the infrasound generated by an air conditioning system (up to 2o kHz) may adversely affect the well-being of human beings. After an introductory explanation of the infrasonic wave band and the dependency of the sound pressure level on the frequency for decibel values of 20 to 100 (diagram), the relevant results of studies by various experts are quoted. It became apparent that the influence of the inaudible infrasound has been greatly overestimated, whereas audibility was underestimated. Inaudible infrasound was shown to be completely harmless. A number of frequency variation analysis diagrams of various residences (old building, new building) with audibility thresholds marked in. The measurement results discussed in more detail indicate that it is possible not to raise the basic noise level of an air conditioning system in the low-frequency range. Therein lies the actual acoustic chance for air conditioning: In an air-conditioned building, there is no need to ventilate by means of open windows, thereby letting in traffic noise, the nuisance value of which is beyond dispute. (HWJ).

  16. Prevalence of occupational noise induced hearing loss amongst traffic police personnel

    OpenAIRE

    Singh, V K; Mehta, A K

    1999-01-01

    Traffic branch personnel of Pune traffic police were screened for presence of noise induced hearing loss. A very significant number (81.2%) showed sensorineural hearing loss. The various factors responsible for noise induced hearing loss are discussed.

  17. Coloured-noise-induced transitions in nonlinear structures

    International Nuclear Information System (INIS)

    Mankin, R.; Laas, T.; Soika, E.; Sauga, A.; Rekker, A.; Ainsaar, A.; Ugaste, Ue.

    2008-01-01

    In a stochastic framework, macroscopic approaches are sought to describe microscopic interaction between different species. Coloured-noise-induced transitions in stochastic N-species Lotka-Volterra systems are considered analytically as an appropriate model expendable to many natural and nano-technological processes. All the results discussed are computed by means of a dynamical mean-field approximation. It is demonstrated that interplay of coloured noise and interaction intensities of species can generate a variety of cooperation effects, such as discontinuous transitions of the mean population density, noise-induced Hopf bifurcations and relaxation oscillation. The necessary conditions for the cooperation effects are also discussed. Particularly, it is established that, in the case of the Beddington functional response, in certain parameter regions of the model an increase in noise correlation time can cause multiple transitions (more than two) between relaxation oscillatory regimes and equilibrium states. (authors)

  18. Macroscopic tunneling, decoherence and noise-induced activation

    Energy Technology Data Exchange (ETDEWEB)

    Lombardo, Fernando C; Monteoliva, Diana; Villar, Paula I [Departamento de Fisica Juan Jose Giambiagi, Facultad de Ciencias Exactas y Naturales, UBA, Ciudad Universitaria, Pabellon I, 1428 Buenos Aires (Argentina)

    2007-05-15

    We study the effects of the environment at zero temperature on tunneling in an open system described by a static double-well potential. We show that the evolution of the system in an initial Schroedinger cat state, can be summarized in terms of three main physical phenomena, namely decoherence, quantum tunneling and noise-induced activation. Using large-scale numerical simulations, we obtain a detailed picture of the main stages of the evolution and of the relevant dynamical processes.

  19. Noise-induced hearing loss: a recreational noise perspective.

    Science.gov (United States)

    Ivory, Robert; Kane, Rebecca; Diaz, Rodney C

    2014-10-01

    This review will discuss the real-world risk factors involved in noise-induced hearing loss as a result of common and popular recreational activities prone to mid and high levels of noise exposure. Although there are currently no interventional measures available to reverse or mitigate preexisting hearing loss from noise, we discuss the vital importance of hearing loss prevention from noise exposure avoidance and reduction. Despite a seeming understanding of the effects of noise exposure from various recreational activities and devices, a large percentage of the general public who is at risk of such noise-induced hearing loss still chooses to refrain from using hearing protection instruments. While occupational exposures pose the greatest traditional risk to hearing conservation in selected workers, recreational risk factors for noise-induced hearing loss may be more insidious in overall effect given the indifferent attitude of much of the general public and particularly our youths toward hearing protection during recreational activities. Active counseling regarding the consequences of excessive noise exposure and the potential benefits to hearing from usage of hearing protection instruments is critical to providing best possible care in the hearing health professions.

  20. Noise-induced drift in two-dimensional anisotropic systems

    Science.gov (United States)

    Farago, Oded

    2017-10-01

    We study the isothermal Brownian dynamics of a particle in a system with spatially varying diffusivity. Due to the heterogeneity of the system, the particle's mean displacement does not vanish even if it does not experience any physical force. This phenomenon has been termed "noise-induced drift," and has been extensively studied for one-dimensional systems. Here, we examine the noise-induced drift in a two-dimensional anisotropic system, characterized by a symmetric diffusion tensor with unequal diagonal elements. A general expression for the mean displacement vector is derived and presented as a sum of two vectors, depicting two distinct drifting effects. The first vector describes the tendency of the particle to drift toward the high diffusivity side in each orthogonal principal diffusion direction. This is a generalization of the well-known expression for the noise-induced drift in one-dimensional systems. The second vector represents a novel drifting effect, not found in one-dimensional systems, originating from the spatial rotation in the directions of the principal axes. The validity of the derived expressions is verified by using Langevin dynamics simulations. As a specific example, we consider the relative diffusion of two transmembrane proteins, and demonstrate that the average distance between them increases at a surprisingly fast rate of several tens of micrometers per second.

  1. Infrasonic measurements of the Non-Proliferation Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Whitaker, R.W.; Noel, S.; Meadows, W. [Los Alamos National Laboratory, NM (United States)

    1994-12-31

    Two infrasonic arrays were operated for the Non-Proliferation Experiment (NPE). The arrays were located at the Nevada Test Site and at St. George, UT. The results were consistent with experience on underground tests, and therefore close to underground nuclear tests of similar size.

  2. Transforming growth factor β1 inhibition protects from noise-induced hearing loss

    Directory of Open Access Journals (Sweden)

    Silvia eMurillo-Cuesta

    2015-03-01

    Full Text Available Excessive exposure to noise damages the principal cochlear structures leading to hearing impairment. Inflammatory and immune responses are central mechanisms in cochlear defensive response to noise but, if unregulated, they contribute to inner ear damage and hearing loss. Transforming growth factor ß (TGF-ß is a key regulator of both responses and high levels of this factor have been associated with cochlear injury in hearing loss animal models. To evaluate the potential of targeting TGF-ß as a therapeutic strategy for preventing or ameliorating noise-induced hearing loss, we studied the auditory function, cochlear morphology, gene expression and oxidative stress markers in mice exposed to noise and treated with TGF-ß1 peptidic inhibitors P17 and P144, just before or immediately after noise insult. Our results indicate that systemic administration of both peptides significantly improved both the evolution of hearing thresholds and the degenerative changes induced by noise-exposure in lateral wall structures. Moreover, treatments ameliorated the inflammatory state and redox balance. These therapeutic effects were dose-dependent and more effective if the TGF-ß1 inhibitors were administered prior to inducing the injury. In conclusion, inhibition of TGF-ß1 actions with antagonistic peptides represents a new, promising therapeutic strategy for the prevention and repair of noise-induced cochlear damage.

  3. Signatures of nonlinearity in single cell noise-induced oscillations.

    Science.gov (United States)

    Thomas, Philipp; Straube, Arthur V; Timmer, Jens; Fleck, Christian; Grima, Ramon

    2013-10-21

    A class of theoretical models seeks to explain rhythmic single cell data by postulating that they are generated by intrinsic noise in biochemical systems whose deterministic models exhibit only damped oscillations. The main features of such noise-induced oscillations are quantified by the power spectrum which measures the dependence of the oscillatory signal's power with frequency. In this paper we derive an approximate closed-form expression for the power spectrum of any monostable biochemical system close to a Hopf bifurcation, where noise-induced oscillations are most pronounced. Unlike the commonly used linear noise approximation which is valid in the macroscopic limit of large volumes, our theory is valid over a wide range of volumes and hence affords a more suitable description of single cell noise-induced oscillations. Our theory predicts that the spectra have three universal features: (i) a dominant peak at some frequency, (ii) a smaller peak at twice the frequency of the dominant peak and (iii) a peak at zero frequency. Of these, the linear noise approximation predicts only the first feature while the remaining two stem from the combination of intrinsic noise and nonlinearity in the law of mass action. The theoretical expressions are shown to accurately match the power spectra determined from stochastic simulations of mitotic and circadian oscillators. Furthermore it is shown how recently acquired single cell rhythmic fibroblast data displays all the features predicted by our theory and that the experimental spectrum is well described by our theory but not by the conventional linear noise approximation. © 2013 Elsevier Ltd. All rights reserved.

  4. Noise-induced transition in a quantum system

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Pulak Kumar [Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032 (India); Barik, Debashis [Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032 (India); Ray, Deb Shankar [Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032 (India)

    2005-07-04

    We examine the noise-induced transition in a fluctuating bistable potential of a driven quantum system in thermal equilibrium. Making use of a Wigner canonical thermal distribution for description of the statistical properties of the thermal bath, we explore the generic effects of quantization like vacuum field fluctuation and tunneling in the characteristic stationary probability distribution functions undergoing transition from unimodal to bimodal nature and in signal-to-noise ratio characterizing the cooperative effect among the noise processes and the weak periodic signal.

  5. Noise-induced transition in a quantum system

    International Nuclear Information System (INIS)

    Ghosh, Pulak Kumar; Barik, Debashis; Ray, Deb Shankar

    2005-01-01

    We examine the noise-induced transition in a fluctuating bistable potential of a driven quantum system in thermal equilibrium. Making use of a Wigner canonical thermal distribution for description of the statistical properties of the thermal bath, we explore the generic effects of quantization like vacuum field fluctuation and tunneling in the characteristic stationary probability distribution functions undergoing transition from unimodal to bimodal nature and in signal-to-noise ratio characterizing the cooperative effect among the noise processes and the weak periodic signal

  6. Cochlear Synaptopathy and Noise-Induced Hidden Hearing Loss

    Directory of Open Access Journals (Sweden)

    Lijuan Shi

    2016-01-01

    Full Text Available Recent studies on animal models have shown that noise exposure that does not lead to permanent threshold shift (PTS can cause considerable damage around the synapses between inner hair cells (IHCs and type-I afferent auditory nerve fibers (ANFs. Disruption of these synapses not only disables the innervated ANFs but also results in the slow degeneration of spiral ganglion neurons if the synapses are not reestablished. Such a loss of ANFs should result in signal coding deficits, which are exacerbated by the bias of the damage toward synapses connecting low-spontaneous-rate (SR ANFs, which are known to be vital for signal coding in noisy background. As there is no PTS, these functional deficits cannot be detected using routine audiological evaluations and may be unknown to subjects who have them. Such functional deficits in hearing without changes in sensitivity are generally called “noise-induced hidden hearing loss (NIHHL.” Here, we provide a brief review to address several critical issues related to NIHHL: (1 the mechanism of noise induced synaptic damage, (2 reversibility of the synaptic damage, (3 the functional deficits as the nature of NIHHL in animal studies, (4 evidence of NIHHL in human subjects, and (5 peripheral and central contribution of NIHHL.

  7. Sensitivity analysis of the noise-induced oscillatory multistability in Higgins model of glycolysis

    Science.gov (United States)

    Ryashko, Lev

    2018-03-01

    A phenomenon of the noise-induced oscillatory multistability in glycolysis is studied. As a basic deterministic skeleton, we consider the two-dimensional Higgins model. The noise-induced generation of mixed-mode stochastic oscillations is studied in various parametric zones. Probabilistic mechanisms of the stochastic excitability of equilibria and noise-induced splitting of randomly forced cycles are analysed by the stochastic sensitivity function technique. A parametric zone of supersensitive Canard-type cycles is localized and studied in detail. It is shown that the generation of mixed-mode stochastic oscillations is accompanied by the noise-induced transitions from order to chaos.

  8. Noise-induced perturbations of dispersion-managed solitons

    International Nuclear Information System (INIS)

    Li, Jinglai; Spiller, Elaine; Biondini, Gino

    2007-01-01

    We study noise-induced perturbations of dispersion-managed solitons. We do so by first developing soliton perturbation theory for the dispersion-managed nonlinear Schroedinger (DMNLS) equation, which governs the long-term behavior of optical fiber transmission systems and certain kinds of femtosecond lasers. We show that the eigenmodes and generalized eigenmodes of the linearized DMNLS equation around traveling-wave solutions can be generated from the invariances of the DMNLS equations, we quantify the perturbation-induced parameter changes of the solution in terms of the eigenmodes and the adjoint eigenmodes, and we obtain evolution equations for the solution parameters. We then apply these results to guide importance-sampled Monte Carlo (MC) simulations and reconstruct the probability density functions of the solution parameters under the effect of noise, and we compare with standard MC simulations of the unaveraged system. The comparison further validates the use of the DMNLS equation as a model for dispersion-managed systems

  9. Minocycline attenuates noise-induced hearing loss in rats.

    Science.gov (United States)

    Zhang, Jing; Song, Yong-Li; Tian, Ke-Yong; Qiu, Jian-Hua

    2017-02-03

    Noise-induced hearing loss (NIHL) is a serious health concern and prevention of hair cell death or therapeutic intervention at the early stage of NIHL is critical to preserve hearing. Minocycline is a semi-synthetic derivative of tetracycline and has been shown to have otoprotective effects in ototoxic drug-induced hearing impairment, however, whether minocycline can protect against NIHL has not been investigated. The present study demonstrated elevated ABR (auditory brainstem response) thresholds and outer hair cell loss following traumatic noise exposure, which was mitigated by intraperitoneal administration of minocycline (45mg/kg/d) for 5 consecutive days. In conclusion, the present study demonstrated that minocycline, a clinically approved drug with a good safety profile, can attenuate NIHL in rats and may potentially be used for treatment of hearing loss in clinic. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  10. Noise-induced cochlear synaptopathy in rhesus monkeys (Macaca mulatta).

    Science.gov (United States)

    Valero, M D; Burton, J A; Hauser, S N; Hackett, T A; Ramachandran, R; Liberman, M C

    2017-09-01

    Cochlear synaptopathy can result from various insults, including acoustic trauma, aging, ototoxicity, or chronic conductive hearing loss. For example, moderate noise exposure in mice can destroy up to ∼50% of synapses between auditory nerve fibers (ANFs) and inner hair cells (IHCs) without affecting outer hair cells (OHCs) or thresholds, because the synaptopathy occurs first in high-threshold ANFs. However, the fiber loss likely impairs temporal processing and hearing-in-noise, a classic complaint of those with sensorineural hearing loss. Non-human primates appear to be less vulnerable to noise-induced hair-cell loss than rodents, but their susceptibility to synaptopathy has not been studied. Because establishing a non-human primate model may be important in the development of diagnostics and therapeutics, we examined cochlear innervation and the damaging effects of acoustic overexposure in young adult rhesus macaques. Anesthetized animals were exposed bilaterally to narrow-band noise centered at 2 kHz at various sound-pressure levels for 4 h. Cochlear function was assayed for up to 8 weeks following exposure via auditory brainstem responses (ABRs) and otoacoustic emissions (OAEs). A moderate loss of synaptic connections (mean of 12-27% in the basal half of the cochlea) followed temporary threshold shifts (TTS), despite minimal hair-cell loss. A dramatic loss of synapses (mean of 50-75% in the basal half of the cochlea) was seen on IHCs surviving noise exposures that produced permanent threshold shifts (PTS) and widespread hair-cell loss. Higher noise levels were required to produce PTS in macaques compared to rodents, suggesting that primates are less vulnerable to hair-cell loss. However, the phenomenon of noise-induced cochlear synaptopathy in primates is similar to that seen in rodents. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Mechanism of Lightning Associated Infrasonic Pulses from Thunderclouds

    Science.gov (United States)

    Pasko, V. P.

    2008-12-01

    The infrasonic waves correspond to the region of frequencies of acoustic sound waves 0.02-10 Hz, higher than the acoustic cut-off frequency but lower than the audible frequencies [e.g., Blanc, Ann. Geophys., 3, 673, 1985]. There is a strong experimental evidence that thunderstorms represent significant sources of infrasonic wave activity spanning a broad altitude range from the troposphere and up to the thermosphere [e.g., Blanc, 1985; Few, in Handbook of Atmospheric Electrodynamics, Vol. 2, edited by H. Volland, pp. 1-31, CRC Press, 1995; Drob et al., JGR, 108, 4680, 2003]. This evidence includes electrostatic production of 0.1- 1 Hz infrasonic waves from thunderclouds [Few, 1995] and recent discovery of infrasound from lightning induced transient luminous events in the mesosphere called sprites [Liszka, J. Low Freq. Noise Vibr. Active Control, 23, 85, 2004; Farges et al., GRL, 32, L13824, 2005; Liszka and Hobara, JASTP, 68, 1179, 2006]. The understanding and classification of different infrasonic waves and their sources is of great current interest from a Comprehensive Nuclear-Test-Ban Treaty (CTBT) verification perspective [e.g., Assink et al., GRL, 35, L15802, 2008]. It has been pointed many decades ago by C. T. R. Wilson [Phil. Trans. R. Soc. London A, 221, 73, 1920] that sudden reduction of the electric field inside a thundercloud immediately following a lightning discharge should produce an infrasound signature. Wilson [1920] noted that the pressure within a charged cloud must be less than the pressure outside, similarly to that within a charged soap bubble. In contrast to the sudden expansion of the air along the track of a lightning flash, the sudden contraction of a large volume of air must furnish a measurable rarefaction pulse [Wilson, 1920]. Many experimental and theoretical contributions followed these predictions by C. T. R. Wilson (see [Few, JGR, 90, 6175, 1985] and extensive list of references therein). Modeling investigation of related scenarios

  12. Noise-induced polarization switching in complex networks

    Science.gov (United States)

    Haerter, Jan O.; Díaz-Guilera, Albert; Serrano, M. Ángeles

    2017-04-01

    The combination of bistability and noise is ubiquitous in complex systems, from biology to social interactions, and has important implications for their functioning and resilience. Here we use a simple three-state dynamical process, in which nodes go from one pole to another through an intermediate state, to show that noise can induce polarization switching in bistable systems if dynamical correlations are significant. In large, fully connected networks, where dynamical correlations can be neglected, increasing noise yields a collapse of bistability to an unpolarized configuration where the three possible states of the nodes are equally likely. In contrast, increased noise induces abrupt and irreversible polarization switching in sparsely connected networks. In multiplexes, where each layer can have a different polarization tendency, one layer is dominant and progressively imposes its polarization state on the other, offsetting or promoting the ability of noise to switch its polarization. Overall, we show that the interplay of noise and dynamical correlations can yield discontinuous transitions between extremes, which cannot be explained by a simple mean-field description.

  13. Noise-induced hearing loss: an occupational medicine perspective.

    Science.gov (United States)

    Stucken, Emily Z; Hong, Robert S

    2014-10-01

    Up to 30 million workers in the United States are exposed to potentially detrimental levels of noise. Although reliable medications for minimizing or reversing noise-induced hearing loss (NIHL) are not currently available, NIHL is entirely preventable. The purpose of this article is to review the epidemiology and pathophysiology of occupational NIHL. We will focus on at-risk populations and discuss prevention programs. Current prevention programs focus on reducing inner ear damage by minimizing environmental noise production and through the use of personal hearing protective devices. NIHL is the result of a complex interaction between environmental factors and patient factors, both genetic and acquired. The effects of noise exposure are specific to an individual. Trials are currently underway evaluating the role of antioxidants in protection from, and even reversal of, NIHL. Occupational NIHL is the most prevalent occupational disease in the United States. Occupational noise exposures may contribute to temporary or permanent threshold shifts, although even temporary threshold shifts may predispose an individual to eventual permanent hearing loss. Noise prevention programs are paramount in reducing hearing loss as a result of occupational exposures.

  14. The Antioxidant Effect of Rosmarinic Acid by Different Delivery Routes in the Animal Model of Noise-Induced Hearing Loss.

    Science.gov (United States)

    Fetoni, Anna R; Eramo, Sara Letizia Maria; Di Pino, Antonella; Rolesi, Rolando; Paciello, Fabiola; Grassi, Claudio; Troiani, Diana; Paludetti, Gaetano

    2018-03-01

    Trans-tympanic Rosmarinic Acid (RA), as compared with the systemic administration, protects against noise-induced auditory hair cell and hearing losses in rats in vivo. ROS production, lipoperoxidative damage, and an imbalance of antioxidant defences play a significant role in noise-induced hearing loss. Several molecules with antioxidant properties have been tested to restore redox homeostasis; however, drug delivery system represents a challenge for their effectiveness. In our model, acute and intense noise exposure induces hearing loss, hair cell death, and oxidative stress, with an increase in superoxide production and over-expression of lipid peroxidation in cochlear structures. RA was administrated in male Wistar rats by trans-tympanic (20 μl) and systemic (10 mg/kg) modality. In systemic administration, RA was injected 1 hour before noise exposure and once daily for the following 3 days. ABRs were measured before and at days 1, 3, 7, and 30 after noise exposure. Rhodamine-phalloidin staining, dihydroethidium and 8-isoprostane immunostainings were performed to assess and quantify outer hair cells loss, superoxide production, and lipid peroxidation in the different experimental groups. Systemic RA administration significantly decreased noise-induced hearing loss and the improvement of auditory function was paralleled by a significant reduction in cochlear oxidative stress. The trans-tympanic modality of drug administration showed a similar degree of protection both at the functional and morphological levels. The effectiveness of RA given via trans-tympanic injection could be interesting for the future application of this minimally-invasive procedure in the treatment of ROS-induced hearing loss.

  15. Towards an accurate real-time locator of infrasonic sources

    Science.gov (United States)

    Pinsky, V.; Blom, P.; Polozov, A.; Marcillo, O.; Arrowsmith, S.; Hofstetter, A.

    2017-11-01

    Infrasonic signals propagate from an atmospheric source via media with stochastic and fast space-varying conditions. Hence, their travel time, the amplitude at sensor recordings and even manifestation in the so-called "shadow zones" are random. Therefore, the traditional least-squares technique for locating infrasonic sources is often not effective, and the problem for the best solution must be formulated in probabilistic terms. Recently, a series of papers has been published about Bayesian Infrasonic Source Localization (BISL) method based on the computation of the posterior probability density function (PPDF) of the source location, as a convolution of a priori probability distribution function (APDF) of the propagation model parameters with likelihood function (LF) of observations. The present study is devoted to the further development of BISL for higher accuracy and stability of the source location results and decreasing of computational load. We critically analyse previous algorithms and propose several new ones. First of all, we describe the general PPDF formulation and demonstrate that this relatively slow algorithm might be among the most accurate algorithms, provided the adequate APDF and LF are used. Then, we suggest using summation instead of integration in a general PPDF calculation for increased robustness, but this leads us to the 3D space-time optimization problem. Two different forms of APDF approximation are considered and applied for the PPDF calculation in our study. One of them is previously suggested, but not yet properly used is the so-called "celerity-range histograms" (CRHs). Another is the outcome from previous findings of linear mean travel time for the four first infrasonic phases in the overlapping consecutive distance ranges. This stochastic model is extended here to the regional distance of 1000 km, and the APDF introduced is the probabilistic form of the junction between this travel time model and range-dependent probability

  16. Novel method of evaluating miners at risk for noise-induced hearing loss

    CSIR Research Space (South Africa)

    Edwards, AL

    2010-08-31

    Full Text Available Noise-induced hearing loss (NIHL) negatively affects the quality of life of mine employees and costs mining companies large amounts in compensation claims. The prevention of NIHL requires early identification and recent evidence about the ability...

  17. Sex Differences in Susceptibility and Resistance to Noise-Induced Hearing Loss in Chinchillas

    National Research Council Canada - National Science Library

    McFadden, Sandra

    1999-01-01

    .... The reasons for individual differences in susceptibility to noise-induced hearing loss (NIHL) are largely unknown, but may include factors such as levels of endogenous antioxidant enzymes or steroid hormones...

  18. Novel BCH Code Design for Mitigation of Phase Noise Induced Cycle Slips in DQPSK Systems

    DEFF Research Database (Denmark)

    Leong, M. Y.; Larsen, Knud J.; Jacobsen, G.

    2014-01-01

    We show that by proper code design, phase noise induced cycle slips causing an error floor can be mitigated for 28 Gbau d DQPSK systems. Performance of BCH codes are investigated in terms of required overhead......We show that by proper code design, phase noise induced cycle slips causing an error floor can be mitigated for 28 Gbau d DQPSK systems. Performance of BCH codes are investigated in terms of required overhead...

  19. In Vitro Studies and Preliminary Mathematical Model for Jet Fuel and Noise Induced Auditory Impairment

    Science.gov (United States)

    2015-06-01

    of JP-8 and a Fischer- Tropsch synthetic jet fuel following subacute inhalation exposure in rats. Toxicol Sci 116(1): 239-248. Gallinat, J...AFRL-RH-WP-TR-2015-0084 IN VITRO STUDIES AND PRELIMINARY MATHEMATICAL MODEL FOR JET FUEL AND NOISE INDUCED AUDITORY IMPAIRMENT...April 2014 – September 2014 4. TITLE AND SUBTITLE In Vitro Studies and Preliminary Mathematical Model for Jet Fuel and Noise Induced Auditory

  20. The consequences of noise-induced hearing loss on dairy farm communities in New Zealand.

    Science.gov (United States)

    Canton, Karen; Williams, Warwick

    2012-01-01

    The objective of this study was to investigate how noise-induced hearing loss (NIHL) or noise injury (NI) affects individuals and others of dairy farm communities in New Zealand. Using "grab" or opportunistic sampling at DairyNZ discussion groups and a recreational function, a survey questionnaire was completed by 74 participants from two dairy farming communities in New Zealand. Self-reported hearing difficulties were highlighted by 48% (42) of the 74 participants. The effects of NI on individuals and others included communication difficulties leading to the development of coping strategies, social isolation; decreased employment opportunities, loss of productivity, and increased effort and adjustments by family and work colleagues. Frustration, anxiety, stress, resentment, depression, and fatigue are also negative consequences that may contribute to a loss of quality of life and contribute to further health costs. Increased lateness, absenteeism, sickness and other behavioral aspects were not expressed as normal issues in the workplace, as the majority of the individuals are/were self-employed or working in a family business. This study shows that each year in New Zealand NI results in significant negative social, psychological, and economic consequences for those individuals affected, along with their families, friends, and work colleagues.

  1. Noise-induced transitions and resonant effects in nonlinear systems

    Science.gov (United States)

    Zaikin, Alexei

    2003-02-01

    Our every-day experience is connected with different acoustical noise or music. Usually noise plays the role of nuisance in any communication and destroys any order in a system. Similar optical effects are known: strong snowing or raining decreases quality of a vision. In contrast to these situations noisy stimuli can also play a positive constructive role, e.g. a driver can be more concentrated in a presence of quiet music. Transmission processes in neural systems are of especial interest from this point of view: excitation or information will be transmitted only in the case if a signal overcomes a threshold. Dr. Alexei Zaikin from the Potsdam University studies noise-induced phenomena in nonlinear systems from a theoretical point of view. Especially he is interested in the processes, in which noise influences the behaviour of a system twice: if the intensity of noise is over a threshold, it induces some regular structure that will be synchronized with the behaviour of neighbour elements. To obtain such a system with a threshold one needs one more noise source. Dr. Zaikin has analyzed further examples of such doubly stochastic effects and developed a concept of these new phenomena. These theoretical findings are important, because such processes can play a crucial role in neurophysics, technical communication devices and living sciences. Unsere alltägliche Erfahrung ist mit verschiedenen akustischen Einfluessen wie Lärm, aber auch Musik verbunden. Jeder weiss, wie Lärm stören kann und Kommunikation behindert oder gar unterbindet. Ähnliche optische Effekte sind bekannt: starkes Schneetreiben oder Regengüsse verschlechtern die Sicht und lassen uns Umrisse nur noch schemenhaft erkennen. Jedoch koennen ähnliche Stimuli auch sehr positive Auswirkungen haben: Autofahrer fahren bei leiser Musik konzentrierter -- die Behauptung von Schulkindern, nur bei dröhnenden Bässen die Mathehausaufgaben richtig rechnen zu können, ist allerdings nicht wissenschaftlich

  2. Noise-induced hearing loss in small-scale metal industry in Nepal.

    Science.gov (United States)

    Whittaker, J D; Robinson, T; Acharya, A; Singh, D; Smith, M

    2014-10-01

    There has been no previous research to demonstrate the risk of noise-induced hearing loss in industry in Nepal. Limited research on occupational noise-induced hearing loss has been conducted within small-scale industry worldwide, despite it being a substantial and growing cause of deafness in the developing world. The study involved a cross-sectional audiometric assessment, with questionnaire-based examinations of noise and occupational history, and workplace noise level assessment. A total of 115 metal workers and 123 hotel workers (control subjects) were recruited. Noise-induced hearing loss prevalence was 30.4 per cent in metal workers and 4.1 per cent in hotel workers, with a significant odds ratio of 10.3. Except for age and time in occupation, none of the demographic factors were significant in predicting outcomes in regression analyses. When adjusted for this finding, and previous noise-exposed occupations, the odds ratio was 13.8. Workplace noise was significantly different between the groups, ranging from 65.3 to 84.7 dBA in metal worker sites, and from 51.4 to 68.6 dBA in the control sites. Metal workers appear to have a greater risk of noise-induced hearing loss than controls. Additional research on occupational noise-induced hearing loss in Nepal and small-scale industry globally is needed.

  3. Historical review of efforts to reduce noise-induced hearing loss in the United States.

    Science.gov (United States)

    Kerr, Madeleine J; Neitzel, Richard L; Hong, OiSaeng; Sataloff, Robert T

    2017-06-01

    Noise-induced hearing loss is a centuries-old problem that is still prevalent in the United States and worldwide. To describe highlights in the development of hearing loss prevention in the U.S. from World War II to the present. Literature review. Approaches to occupational noise-induced hearing loss prevention in the United States over the past seven decades are described using a hierarchy of controls framework and an interdisciplinary perspective. Historical timelines and developmental milestones related to occupational noise-induced hearing loss prevention are summarized as a life course. Lessons are drawn for other countries in their hearing conservation efforts. Future developments building on the hearing loss prevention work of the past 70 years can prevent the problem of occupational NIHL in the 21st century. Am. J. Ind. Med. 60:569-577, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  4. Ascorbic acid reduces noise-induced nitric oxide production in the guinea pig ear.

    Science.gov (United States)

    Heinrich, Ulf-Rüdiger; Fischer, Ilka; Brieger, Jürgen; Rümelin, Andreas; Schmidtmann, Irene; Li, Huige; Mann, Wolf J; Helling, Kai

    2008-05-01

    Noise-induced hearing loss can be caused, among other causes, by increased nitric oxide (NO) production in the inner ear leading to nitroactive stress and cell destruction. Some studies in the literature suggest that the degree of hearing loss (HL) could be reduced in an animal model through ascorbic acid supplementation. To identify the effect of ascorbic acid on tissue-dependent NO content in the inner ear of the guinea pig, we determined the local NO production in the organ of Corti and the lateral wall separately 6 hours after noise exposure. Prospective animal study in guinea pigs. Over a period of 7 days, male guinea pigs were supplied with minimum (25 mg/kg body weight/day) and maximum (525 mg/kg body weight/day) ascorbic acid doses, and afterwards exposed to noise (90 dB sound pressure level for 1 hour). The acoustic-evoked potentials were recorded before and after noise exposure. The organ of Corti and the lateral wall were incubated differently for 6 hours in culture medium, and the degree of NO production was determined by chemiluminescence. Ascorbic acid treatment reduced the hearing threshold shift after noise exposure depending on concentration. When the maximum ascorbic acid dose was substituted, NO production was significantly reduced in the lateral wall after noise exposure and slightly reduced in the organ of Corti. Oral supplementation of the natural radical scavenger ascorbic acid reduces the NO-production rate in the inner ear in noisy conditions. This finding supports the concept of inner ear protection by ascorbic acid supplementation.

  5. Coherence Resonance and Noise-Induced Synchronization in Hindmarsh-Rose Neural Network with Different Topologies

    International Nuclear Information System (INIS)

    Wei Duqu; Luo Xiaoshu

    2007-01-01

    In this paper, we investigate coherence resonance (CR) and noise-induced synchronization in Hindmarsh-Rose (HR) neural network with three different types of topologies: regular, random, and small-world. It is found that the additive noise can induce CR in HR neural network with different topologies and its coherence is optimized by a proper noise level. It is also found that as coupling strength increases the plateau in the measure of coherence curve becomes broadened and the effects of network topology is more pronounced simultaneously. Moreover, we find that increasing the probability p of the network topology leads to an enhancement of noise-induced synchronization in HR neurons network.

  6. Physical model study of neutron noise induced by vibration of reactor internals

    International Nuclear Information System (INIS)

    Liu Jinhui; Gu Fangyu

    1999-01-01

    The author presents a physical model of neutron noise induced by reactor internals vibration in frequency domain. Based on system control theory, the reactor dynamic equations are coupled with random vibration equation, and non-linear terms are also taken into accounted while treating the random vibration. Experiments carried out on a zero-power reactor show that the model can be used to describe dynamic character of neutron noise induced by internals' vibration. The model establishes a method to help to determine internals'vibration features, and to diagnosis anomalies through neutron noise

  7. Wake Vortex Detection: Phased Microphone vs. Linear Infrasonic Array

    Science.gov (United States)

    Shams, Qamar A.; Zuckerwar, Allan J.; Sullivan, Nicholas T.; Knight, Howard K.

    2014-01-01

    infrasonic array at the Newport News-Williamsburg International Airport early in the year 2013. A pattern of pressure burst, high-coherence intervals, and diminishing-coherence intervals was observed for all takeoff and landing events without exception. The results of a phased microphone vs. linear infrasonic array comparison will be presented.

  8. Infrasonic Detection of a Large Bolide over South Sulawesi, Indonesia on October 8, 2009: Preliminary Results

    Science.gov (United States)

    Silber, E. A.; Brown, P. G.; Le Pinchon, A.

    2011-01-01

    In the morning hours of October 8, 2009, a bright object entered Earth's atmosphere over South Sulawesi, Indonesia. This bolide disintegrated above the ground, generating stratospheric infrasound returns that were detected by infrasonic stations of the global International Monitoring System (IMS) Network of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) at distances up to 17 500 km. Here we present instrumental recordings and preliminary results of this extraordinary event. Using the infrasonic period-yield relations, originally derived for atmospheric nuclear detonations, we find the most probable source energy for this bolide to be 70+/-20 kt TNT equivalent explosive yield. A unique aspect of this event is the fact that it was apparently detected by infrasound only. Global events of such magnitude are expected only once per decade and can be utilized to calibrate infrasonic location and propagation tools on a global scale, and to evaluate energy yield formula, and event timing.

  9. Noise.Induced Hearing Loss Still a Problem in Shipbuilders: A Cross ...

    African Journals Online (AJOL)

    Background: Workplace safety regulations seek to mitigate noise.induced hearing loss (NIHL), conventionally associated with the shipbuilding industry. Despite this, are workers still predisposed to NIHL? Aims: To study the prevalence of NIHL among noise.exposed subjects in the shipbuilding industry in Goa and to ...

  10. Effects of noise-induced hearing loss within Port Harcourt metropolis ...

    African Journals Online (AJOL)

    This paper investigates the effects of Noise-Induced Hearing Loss within Port Harcourt Metropolis using a micro-controlled diagnostic audiometer (Kamplex KLD21).The data was obtained at two specific locations namely: Rivers State University of Science and Technology and Port Harcourt International Airport.

  11. Pitch and Loudness from Tinnitus in Individuals with Noise-induced Hearing Loss

    Directory of Open Access Journals (Sweden)

    Flores, Leticia Sousa

    2015-08-01

    Full Text Available Introduction Tinnitus is one of the symptoms that affects individuals suffering from noise induced hearing loss. This condition can be disabling, leading the affected individual to turn away from work. Objective This literature review aims to analyze the possible association between gender and tinnitus pitch and loudness, the degree of hearing loss and the frequencies affected in subjects with noise-induced hearing loss. Methods This contemporary cohort study was conducted through a cross-sectional analysis. The study sample consisted of adults with unilateral or bilateral tinnitus, who had been diagnosed with noise-induced hearing loss. The patients under analysis underwent an otorhinolaryngological evaluation, pure tone audiometry, and acuphenometry. Results The study included 33 subjects with noise-induced hearing loss diagnoses, of which 22 (66.7% were men. Authors observed no statistical difference between gender and loudness/pitch tinnitus and loudness/pitch in subjects with bilateral tinnitus. Authors found an inverse relation between tinnitus loudness with intensity greater hearing threshold and the average of the thresholds and the grade of hearing loss. The tinnitus pitch showed no association with higher frequency of hearing threshold. Conclusion Data analysis shows that, among the individuals evaluated, the greater the hearing loss, the lower the loudness of tinnitus. We did not observe an association between hearing loss and tinnitus pitch.

  12. Noise induced hearing loss: Screening with pure-tone audiometry and speech-in-noise testing

    NARCIS (Netherlands)

    Leensen, M.C.J.

    2013-01-01

    Noise-induced hearing loss (NIHL) is a highly prevalent public health problem, caused by exposure to loud noises both during leisure time, e.g. by listening to loud music, and during work. In the past years NIHL was the most commonly reported occupational disease in the Netherlands. Hearing damage

  13. Effects of noise-induced hearing loss on parvalbumin and perineuronal net expression in the mouse primary auditory cortex.

    Science.gov (United States)

    Nguyen, Anna; Khaleel, Haroun M; Razak, Khaleel A

    2017-07-01

    Noise induced hearing loss is associated with increased excitability in the central auditory system but the cellular correlates of such changes remain to be characterized. Here we tested the hypothesis that noise-induced hearing loss causes deterioration of perineuronal nets (PNNs) in the auditory cortex of mice. PNNs are specialized extracellular matrix components that commonly enwrap cortical parvalbumin (PV) containing GABAergic interneurons. Compared to somatosensory and visual cortex, relatively less is known about PV/PNN expression patterns in the primary auditory cortex (A1). Whether changes to cortical PNNs follow acoustic trauma remains unclear. The first aim of this study was to characterize PV/PNN expression in A1 of adult mice. PNNs increase excitability of PV+ inhibitory neurons and confer protection to these neurons against oxidative stress. Decreased PV/PNN expression may therefore lead to a reduction in cortical inhibition. The second aim of this study was to examine PV/PNN expression in superficial (I-IV) and deep cortical layers (V-VI) following noise trauma. Exposing mice to loud noise caused an increase in hearing threshold that lasted at least 30 days. PV and PNN expression in A1 was analyzed at 1, 10 and 30 days following the exposure. No significant changes were observed in the density of PV+, PNN+, or PV/PNN co-localized cells following hearing loss. However, a significant layer- and cell type-specific decrease in PNN intensity was seen following hearing loss. Some changes were present even at 1 day following noise exposure. Attenuation of PNN may contribute to changes in excitability in cortex following noise trauma. The regulation of PNN may open up a temporal window for altered excitability in the adult brain that is then stabilized at a new and potentially pathological level such as in tinnitus. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Simultaneous infrasonic, seismic, magnetic and ionospheric observations in an earthquake epicentre

    Czech Academy of Sciences Publication Activity Database

    Laštovička, Jan; Baše, Jiří; Hruška, František; Chum, Jaroslav; Šindelářová, Tereza; Horálek, Josef; Zedník, Jan; Krasnov, V.

    2010-01-01

    Roč. 72, č. 16 (2010), s. 1231-1240 ISSN 1364-6826 R&D Projects: GA ČR GA205/07/1367 Institutional research plan: CEZ:AV0Z30420517; CEZ:AV0Z30120515 Keywords : Earthquake * Infrasonic effects * Ionospheric effects * Magnetic effects Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 1.579, year: 2010

  15. Validation of Noise Induced Hearing Loss Questionnaire Among Malay Sawmill Workers in Kelantan Malaysia

    OpenAIRE

    Razman, MR; Naing, L; Aziah, D; Kamarul, IM

    2010-01-01

    Exposure to excessive noise is the major avoidable cause of permanent hearing impairment. Sawmill is one of the workplaces where workers are exposed to hazardous noise level. This study was conducted to determine the reliability and validity of noise-induced hearing loss questionnaire among sawmill workers. Materials and Methods: This cross sectional study was conducted in March 2007 among 35 consented sawmill workers. A total of 40 items; 10 items for knowledge (8 areas), 20 items for attitu...

  16. Numerical results on noise-induced dynamics in the subthreshold regime for thermoacoustic systems

    Science.gov (United States)

    Gupta, Vikrant; Saurabh, Aditya; Paschereit, Christian Oliver; Kabiraj, Lipika

    2017-03-01

    Thermoacoustic instability is a serious issue in practical combustion systems. Such systems are inherently noisy, and hence the influence of noise on the dynamics of thermoacoustic instability is an aspect of practical importance. The present work is motivated by a recent report on the experimental observation of coherence resonance, or noise-induced coherence with a resonance-like dependence on the noise intensity as the system approaches the stability margin, for a prototypical premixed laminar flame combustor (Kabiraj et al., Phys. Rev. E, 4 (2015)). We numerically investigate representative thermoacoustic models for such noise-induced dynamics. Similar to the experiments, we study variation in system dynamics in response to variations in the noise intensity and in a critical control parameter as the systems approach their stability margins. The qualitative match identified between experimental results and observations in the representative models investigated here confirms that coherence resonance is a feature of thermoacoustic systems. We also extend the experimental results, which were limited to the case of subcritical Hopf bifurcation, to the case of supercritical Hopf bifurcation. We identify that the phenomenon has qualitative differences for the systems undergoing transition via subcritical and supercritical Hopf bifurcations. Two important practical implications are associated with the findings. Firstly, the increase in noise-induced coherence as the system approaches the onset of thermoacoustic instability can be considered as a precursor to the instability. Secondly, the dependence of noise-induced dynamics on the bifurcation type can be utilised to distinguish between subcritical and supercritical bifurcation prior to the onset of the instability.

  17. Noise Induced Hearing Loss Among Cotton Textile and Carpet Mill Workers

    OpenAIRE

    ERTEM, Melikşah

    1998-01-01

    In industry increased mechanisation results in increased noise levels. Operation of textile machines carries a high risk of hearing loss. In this study the evaluation of textile worker's noise induced hearing loss was reviewed cross sectionally. The hearing of 260 textile workers exposed to noise levels between 85-95 dB(A) in carpet and cotton textile factories was assessed by means of air and bone conductance audiograms obtained. The subjects were grouped into five hearin...

  18. Activation barrier scaling and crossover for noise-induced switching in micromechanical parametric oscillators.

    Science.gov (United States)

    Chan, H B; Stambaugh, C

    2007-08-10

    We explore fluctuation-induced switching in parametrically driven micromechanical torsional oscillators. The oscillators possess one, two, or three stable attractors depending on the modulation frequency. Noise induces transitions between the coexisting attractors. Near the bifurcation points, the activation barriers are found to have a power law dependence on frequency detuning with critical exponents that are in agreement with predicted universal scaling relationships. At large detuning, we observe a crossover to a different power law dependence with an exponent that is device specific.

  19. [Hearing loss and idoneity--the segnalation of noise-induced hearing loss hearing Loss].

    Science.gov (United States)

    Albera, Roberto; Dagna, Federico; Cassandro, Claudia; Canale, Andrea

    2011-01-01

    Work idoneity in hearing loss must be related to working ability and evolution risks. Working ability is referred to the difficulties found in speech comprehension and in signals perception. As regards hearing loss evolution it is necessary to define if the subject is affected by conductive or neurosensorial hearing loss. In conductive hearing loss it is necessary to evaluate entity and frequential distribution of the deficit. In neurosensorial hearing loss it is necessary to distinguish between noise-induced hearing loss and extraprofessional hearing loss. In noise-induced hearing loss the evolution risk is high if the noise exposure is less than 10-15 years or the actual noise exposure is louder than the former. In case of extraprofessional hearing loss the evolution risk is higher in presbycusis, endolymphatic hydrops and toxic hearing loss. The necessity to report the presence on professionale noise-induced hearing loss arises if audiometric threshold is more than 25 dB at 0.5-1-2-3-4 kHz and if it is verified the professional origine of hearing loss.

  20. Noise Induced Hearing Loss in Iran: (1997–2012): Systematic Review Article

    Science.gov (United States)

    SOLTANZADEH, Ahmad; EBRAHIMI, Hossein; FALLAHI, Majid; KAMALINIA, Mojtaba; GHASSEMI, Shadi; GOLMOHAMMADI, Rostam

    2014-01-01

    Noise-induced hearing loss, which is one of the 10 leading occupational diseases, is a debilitating and irreversible disease. During the recent 15-years period (1997–2012), several studies have investigated the association between noise, hearing damage and other side effects of noise in Iran. The aim of this study was to review systematically the relevant literature related to noise-induced hearing loss, lead to developing noise exposure limits. In this systematic review, two researchers independently extracted the data from 31 past studies that had considered noise-induced hearing loss (including hearing loss, temporary and permanent hearing threshold shift and auditory trauma). The data were then recorded in a modified form and Statistical analyses were performed using SPSS, version 16.0. In analyzed studies the weighted average equivalent sound pressure level [L Aeq ] was 90.29 dB(A) and average hearing loss was 26.44 dB(A). The Highest degree of hearing loss in the right ear was associated at 4000 Hz, and the highest degree of hearing loss in the left ear was associated to 1000 and 4000 Hz. The majority of the reviewed studies have confirmed that exposure to a noise level above 85 dB (A) can lead to an increased chance of hearing loss. Furthermore, the results of the present review indicated that as L Aeq increased up to 85 dB(A), so did the severity of the hearing loss. PMID:26171352

  1. The Protective Effect of Conditioning on Noise-Induced Hearing Loss Is Frequency-Dependent

    Directory of Open Access Journals (Sweden)

    Akram Pourbakht

    2012-10-01

    Full Text Available We compared the extent of temporary threshold shift (TTS and hair cell loss following high level 4 kHz noise exposure with those preconditioned with moderate level 1 and 4 kHz octave band noise. Fifteen Male albino guinea pigs (300- 350 g in weight were randomly allocated into three groups: those exposed to 4 kHz octave band noise at 102 dB SPL (group 1, n=5; those conditioned with 1 kHz octave band noise at 85 dB SPL, 6 hours per day for 5 days, then exposed to noise (group 2, n=5; those conditioned with 4 kHz octave band noise at 85 dB SPL, then exposed to noise (group 3, n=5. An hour and one week after noise exposure, threshold shifts were evaluated by auditory-evoked brainstem response (ABR and then animals were euthanized for histological evaluation. We found that TTS and cochlear damage caused by noise exposure were significantly reduced by 1 kHz and 4 kHz conditioning (P<0.001. We also showed that 4 kHz protocol attenuates noise- induced TTS but no significant TTS reduction occurred by 1 kHz conditioning. Both protocol protected noise-induced cochlear damage. We concluded that lower tone conditioning could not protect against higher tone temporary noise-induced hearing loss, thus conditioning is a local acting and frequency-dependent phenomenon.

  2. Comparison of Auditory Brainstem Response in Noise Induced Tinnitus and Non-Tinnitus Control Subjects

    Directory of Open Access Journals (Sweden)

    Ghassem Mohammadkhani

    2009-12-01

    Full Text Available Background and Aim: Tinnitus is an unpleasant sound which can cause some behavioral disorders. According to evidence the origin of tinnitus is not only in peripheral but also in central auditory system. So evaluation of central auditory system function is necessary. In this study Auditory brainstem responses (ABR were compared in noise induced tinnitus and non-tinnitus control subjects.Materials and Methods: This cross-sectional, descriptive and analytic study is conducted in 60 cases in two groups including of 30 noise induced tinnitus and 30 non-tinnitus control subjects. ABRs were recorded ipsilateraly and contralateraly and their latencies and amplitudes were analyzed.Results: Mean interpeak latencies of III-V (p= 0.022, I-V (p=0.033 in ipsilatral electrode array and mean absolute latencies of IV (p=0.015 and V (p=0.048 in contralatral electrode array were significantly increased in noise induced tinnitus group relative to control group. Conclusion: It can be concluded from that there are some decrease in neural transmission time in brainstem and there are some sign of involvement of medial nuclei in olivery complex in addition to lateral lemniscus.

  3. Model for Estimating Noise-Induced Hearing Loss Associated With Occupational Noise Exposure in a Specified US Navy Population

    National Research Council Canada - National Science Library

    Tufts, Jennifer; Weathersby, Paul K; Marshall, Lynne; Sachs, Felix

    2007-01-01

    This report details the initial steps in the development of a method for modeling the noise-induced hearing loss accrued by a population of Sailors exposed to high-level steady-state occupational noise...

  4. The ecological and evolutionary consequences of noise-induced acoustic habitat loss

    Science.gov (United States)

    Tennessen, Jennifer Beissinger

    negative physiological consequences, and that populations have adapted over short timescales to minimize the detrimental impacts of this novel pressure. Finally, I present results from a field acoustic playback experiment that show that noise from the invasive Cuban treefrog (Osteopilus septentrionalis ) differentially affects the vocal behavior of native anurans, with those with more similar calls being disproportionally more affected. Green treefrogs (Hyla cinerea) shortened their calls, called louder, and maintained call spacing (e.g. continued actively calling) during noise stimuli whereas pine woods treefrogs (H. femoralis) did not modify vocal behavior in response to any noise stimuli. Collectively, the results of these investigations (1) provide insight into the extent of noise-induced acoustic habitat loss in space and time, (2) reveal fitness-relevant individual- and population-level consequences of this form of habitat loss, and (3) show resiliency within ecological systems through the individual- and population-level responses to this novel pressure over short time-scales. These findings advance the field by illustrating how the spatiotemporal extent of anthropogenic noise impacts important ecological processes, and by demonstrating the resiliency of some species in responding rapidly to novel pressures.

  5. The Effect of the Cholesterol Levels on Noise-Induced Hearing Loss.

    Science.gov (United States)

    Demir, Mehmet Gokhan; Aydin, Sedat

    2018-01-01

    Introduction  Noise-induced hearing loss (NIHL), which is one of the most common occupational diseases among industrialized populations, is associated with longstanding exposure to high levels of noise. The pathogenesis of NIHL is not clear, but some genes and their activity at the tissue level have been investigated. Hypercholesterolemia, which can disturb the microcirculation, can be one of the underlying pathologies in hearing loss. Objective  To investigate the relationship between NIHL and hypercholesterolemia. Methods  The study group was selected among workers who had an occupational exposure of 85 dB of noise for at least 10 years. The audiologic assessment was recorded at seven frequencies (500 Hz, 1,000 Hz, 2,000 Hz, 3,000 Hz, 4,000 Hz, 6,000 Hz and 8,000 Hz). A total of 456 workers were included in the study and divided into two groups: the control group (252 patients) and the NIHL group (204 patients). After the audiologic measurement, blood samples were taken and investigated for blood cholesterol levels. According to these results, the groups were compared. Results  Both groups were similarly distributed regarding age and occupational exposure time ( p  > 0.05). We could not detect any association between cholesterol levels and noise-induced hearing loss ( p   0.05). Conclusion  Noise-induced hearing loss is still a common occupational problem that can be prevented by hearing conservation programs and occupational health and safety training. Still, we know little about the relationship between NIHL and hypercholesterolemia. According to our findings, we cannot detect any relationship. Controlled studies and studies with human individuals can be made possible in the future with diagnostic innovations in tissue imaging and tissue microcircular sampling.

  6. Swept-sine noise-induced damage as a hearing loss model for preclinical assays

    Directory of Open Access Journals (Sweden)

    Lorena eSanz

    2015-02-01

    Full Text Available Mouse models are key tools for studying cochlear alterations in noise-induced hearing loss and for evaluating new therapies. Stimuli used to induce deafness in mice are usually white and octave band noises that include very low frequencies, considering the large mouse auditory range. We designed different sound stimuli, enriched in frequencies up to 20 kHz (violet noises to examine their impact on hearing thresholds and cochlear cytoarchitecture after short exposure. In addition, we developed a cytocochleogram to quantitatively assess the ensuing structural degeneration and its functional correlation. Finally, we used this mouse model and cochleogram procedure to evaluate the potential therapeutic effect of transforming growth factor β1 inhibitors P17 and P144 on noise-induced hearing loss. CBA mice were exposed to violet swept-sine noise with different frequency ranges (2-20 or 9-13 kHz and levels (105 or 120 dB SPL for 30 minutes. Mice were evaluated by auditory brainstem response and otoacoustic emission tests prior to and 2, 14 and 28 days after noise exposure. Cochlear pathology was assessed with gross histology; hair cell number was estimated by a stereological counting method. Our results indicate that functional and morphological changes induced by violet swept-sine noise depend on the sound level and frequency composition. Partial hearing recovery followed the exposure to 105 dB SPL, whereas permanent cochlear damage resulted from the exposure to 120 dB SPL. Exposure to 9-13 kHz noise caused an auditory threshold shift in those frequencies that correlated with hair cell loss in the corresponding areas of the cochlea that were spotted on the cytocochleogram. In summary, we present mouse models of noise-induced hearing loss, which depending on the sound properties of the noise, cause different degrees of cochlear damage, and could therefore be used to study molecules which are potential players in hearing loss protection and repair.

  7. Renexin as a rescue regimen for noise-induced hearing loss

    Directory of Open Access Journals (Sweden)

    So Young Park

    2014-01-01

    Full Text Available Renexin, a compound of cilostazol and ginkgo biloba extract, has been reported to produce neuroprotective effects through antioxidant, antiplatelet, and vasodilatory mechanisms. This study was designed to investigate the protective effects of renexin on hearing, the organ of Corti (OC, and medial olivocochlear efferents against noise-induced damage. C57BL/6 mice were exposed to 110 dB SPL white noise for 60 min and then randomly divided into three groups: high- and low-dose renexin-treated groups and noise only group. Renexin were administered for 7 days: 90 mg/kg to the low-dose, and 180 mg/kg to the high-dose groups. All mice, including the controls underwent hearing tests on postnoise day 8 and were killed for cochlear harvest. We compared the hearing thresholds and morphology of the OC and cochlear efferents across the groups. The renexin-treated groups recovered from the immediate threshold shifts in a dose-dependent manner, while the noise group showed a permanent hearing loss. The renexin-treated ears demonstrated less degeneration of the OC. The diameters of the efferent terminals labeled with α-synuclein were preserved in the high-dose renexin-treated group. In the western blot assay of the cochlear homogenates, the treated groups displayed stronger expressions of α-synuclein than the noise and control groups, which may indicate that noise-induced enhanced activity of the cochlear efferent system was protected by renexin. Our results suggest that pharmacologic treatment with renexin is hopeful to reduce or prevent noise-induced hearing loss as a rescue regimen after noise exposure.

  8. [The role of acoustic impedance test in the diagnosis for occupational noise induced deafness].

    Science.gov (United States)

    Chen, H; Xue, L J; Yang, A C; Liang, X Y; Chen, Z Q; Zheng, Q L

    2018-01-20

    Objective: To investigate the characteristics of acoustic impedance test and its diagnostic role for occupational noise induced deafness, in order to provide an objective basis for the differential diagnosis of occupational noise induced deafness. Methods: A retrospective study was conducted to investigate the cases on the diagnosis of occupational noise-induced deafness in Guangdong province hospital for occupational disease prevention and treatment from January 2016 to January 2017. A total of 198 cases (396 ears) were divided into occupation disease group and non occupation disease group based on the diagnostic criteria of occupational noise deafness in 2014 edition, acoustic conductivity test results of two groups were compared including tympanograms types, external auditory canal volume, tympanic pressure, static compliance and slope. Results: In the occupational disease group, 204 ears were found to have 187 ears (91.67%) of type A, which were significantly higher than those in the non occupational disease group 143/192 (74.48%) , the difference was statistically significant (χ(2)=21.038, P occupation disease group in other type were 16/204 (7.84%) , 3/204 (1.47%) , were lower than Ad or As type of occupation disease group (15.63%) , other type (9.38%) , the differences were statistically significant[ (χ(2)=5.834, P Occupation disease group canal volume average (1.68±0.39) ml higher than that of non occupation disease group (1.57 ± 0.47) ml, the difference was statistically significant ( t =2.756, P occupation disease group mean static compliance (1.06±0.82) ml higher than that of non occupation disease group (0.89±0.64) ml. The difference was statistically singificant ( t =2.59, P occupational noise induced deafness, More than 90% of the confirmed cases showed an A-form tympanograms, it is one of the objective examination methods which can be used in the differential diagnosis of pseudo deafness.

  9. Comparative assessment of different treatment modalities in miners with vibration- and noise-induced disease

    Energy Technology Data Exchange (ETDEWEB)

    Velskaya, M.L.; Nekhorosheva, M.A.; Konovalova, S.I.; Kukhtina, G.V.; Gonchar, I.G.; Terentyeva, D.P.; Grishchenko, L.A.; Soboleva, N.P.; Kharitonov, S.A.; Priklonskiy, I.V.

    1985-02-01

    A group of 71 miners with vibration sickness and noise-induced pathology were managed either by standard methods, or in combination with acupuncture and/or hyperbaric oxygenation for a comparative assessment of the effectiveness of the different therapeutic approaches. Analysis of subjective factors as well as standard physiological parameters (EKG, rheoencephalography, peripheral rheography, EEG, neuropsychological tests) demonstrate that both acupuncture and hyperbaric oxygenation are effective modalities in the majority of the subjects. Nevertheless, the lack of improvement in certain criteria, or even what could be regarded as adverse sequelae, suggest that the use of hyperbaric oxygenation in the management of such disorders be approached with considerable care.

  10. Evaluation of the risk of noise-induced hearing loss among unscreened male industrial workers

    Science.gov (United States)

    Prince, Mary M.; Gilbert, Stephen J.; Smith, Randall J.; Stayner, Leslie T.

    2003-02-01

    Variability in background risk and distribution of various risk factors for hearing loss may explain some of the diversity in excess risk of noise-induced hearing loss (NIHL). This paper examines the impact of various risk factors on excess risk estimates of NIHL using data from the 1968-1972 NIOSH Occupational Noise and Hearing Survey (ONHS). Previous analyses of a subset of these data focused on 1172 highly ``screened'' workers. In the current analysis, an additional 894 white males (609 noise-exposed and 285 controls), who were excluded for various reasons (i.e., nonoccupational noise exposure, otologic or medical conditions affecting hearing, prior occupational noise exposure) have been added (n=2066) to assess excess risk of noise-induced material impairment in an unscreened population. Data are analyzed by age, duration of exposure, and sound level (8-h TWA) for four different definitions of noise-induced hearing impairment, defined as the binaural pure-tone average (PTA) hearing threshold level greater than 25 dB for the following frequencies: (a) 1-4 kHz (PTA1234), (b) 1-3 kHz (PTA123), (c) 0.5, 1, and 2 kHz (PTA512), and (d) 3, 4, and 6 kHz (PTA346). Results indicate that populations with higher background risks of hearing loss may show lower excess risks attributable to noise relative to highly screened populations. Estimates of lifetime excess risk of hearing impairment were found to be significantly different between screened and unscreened population for noise levels greater than 90 dBA. Predicted age-related risk of material hearing impairment in the ONHS unscreened population was similar to that predicted from Annex B and C of ANSI S3.44 for ages less than 60 years. Results underscore the importance of understanding differential risk patterns for hearing loss and the use of appropriate reference (control) populations when evaluating risk of noise-induced hearing impairment among contemporary industrial populations.

  11. [Criteria for the assessment of the noise-induced occupational hearing loss: international and national standards].

    Science.gov (United States)

    Izmerov, N F; Denisov, É I; Adeninskaia, E E; Gorblianskiĭ, Iu Iu

    2014-01-01

    The objective of the present paper was to review international and national standards for the criteria of assessment of the noise-induced occupational loss of hearing. The importance of healthy hearing for the occupational safety is emphasized which implies the necessity of the more rigorous criteria for hearing conservation in the workers engaged in the noisy technological environment compared with those for the general population. A rationale for the development of the standard program of hearing conservation in the workers engaged in the noisy technological environment is proposed including hygienic norms and rules or national state standards.

  12. Characterization of blasts in medium and low thermosphere from infrasonic wave observations

    International Nuclear Information System (INIS)

    Lalande, J.M.

    2012-01-01

    The International Monitoring System (IMS) designed to monitor compliance with the Comprehensive Nuclear Test-Ban Treaty (CTBT) uses four complementary verification methods: seismic, hydro-acoustic, radionuclide and micro-barometric stations spanning the entire globe. Micro-barometric stations record continuously infrasonic waves in the frequency band 0.02-4 Hz. These waves propagate at long-ranges through atmospheric ducts resulting from the natural stratification of atmospheric properties (temperature, density, winds,...) and represent a valuable information to understand atmospheric dynamic until the lower thermosphere. In this thesis, we seek to determine the possible contribution of infra-sound observations for improving current atmospheric specifications. We describe the atmospheric media and its circulation mechanisms as well as the conventional observations used in the development of atmospheric models. A description of the interaction between infrasonic waves and the atmosphere help to understand the interest of micro-barometric measurement compared with conventional observations. To highlight this potential we develop an inverse algorithm in order to estimate atmospheric parameters from infrasonic observations. The forward problem is handled by a ray-tracing algorithm. First-order perturbation equation resulting from perturbation of atmospheric properties, and especially wind parameters, are developed and numerically validated. We then analyse the inverse problem through several numerical experiments in order to show the capabilities and limitations of our algorithm. Results show the suitability of our approach and indicate that infrasonic observations can significantly improve current atmospheric specification at the altitudes of acoustic energy refraction, i.e. around 50 km and between 100 and 120 km. (author)

  13. RECENT ADVANCES AND DIFFICULTIES OF INFRASONIC WAVE INVESTIGATION IN THE IONOSPHERE

    Czech Academy of Sciences Publication Activity Database

    Krasnov, Valerij Michailovič; Drobzheva, Yana Viktorovna; Laštovička, Jan

    2006-01-01

    Roč. 27, č. 2 (2006), s. 169-209 ISSN 0169-3298 R&D Projects: GA ČR GA205/04/2110 Institutional research plan: CEZ:AV0Z30420517 Keywords : acoustic wave * atmosphere * Doppler measurement * energy transfer * explosion monitoring * infrasonic sources * ionosphere * nonlinear effect * radio wave Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 1.452, year: 2006

  14. Lévy stable noise-induced transitions: stochastic resonance, resonant activation and dynamic hysteresis

    International Nuclear Information System (INIS)

    Dybiec, Bartłomiej; Gudowska-Nowak, Ewa

    2009-01-01

    A standard approach to analysis of noise-induced effects in stochastic dynamics assumes a Gaussian character of the noise term describing interaction of the analyzed system with its complex surroundings. An additional assumption about the existence of timescale separation between the dynamics of the measured observable and the typical timescale of the noise allows external fluctuations to be modeled as temporally uncorrelated and therefore white. However, in many natural phenomena the assumptions concerning the above mentioned properties of 'Gaussianity' and 'whiteness' of the noise can be violated. In this context, in contrast to the spatiotemporal coupling characterizing general forms of non-Markovian or semi-Markovian Lévy walks, so called Lévy flights correspond to the class of Markov processes which can still be interpreted as white, but distributed according to a more general, infinitely divisible, stable and non-Gaussian law. Lévy noise-driven non-equilibrium systems are known to manifest interesting physical properties and have been addressed in various scenarios of physical transport exhibiting a superdiffusive behavior. Here we present a brief overview of our recent investigations aimed at understanding features of stochastic dynamics under the influence of Lévy white noise perturbations. We find that the archetypal phenomena of noise-induced ordering are robust and can be detected also in systems driven by memoryless, non-Gaussian, heavy-tailed fluctuations with infinite variance

  15. Stochastic amplification and signaling in enzymatic futile cycles through noise-induced bistability with oscillations

    Science.gov (United States)

    Samoilov, Michael; Plyasunov, Sergey; Arkin, Adam P.

    2005-02-01

    Stochastic effects in biomolecular systems have now been recognized as a major physiologically and evolutionarily important factor in the development and function of many living organisms. Nevertheless, they are often thought of as providing only moderate refinements to the behaviors otherwise predicted by the classical deterministic system description. In this work we show by using both analytical and numerical investigation that at least in one ubiquitous class of (bio)chemical-reaction mechanisms, enzymatic futile cycles, the external noise may induce a bistable oscillatory (dynamic switching) behavior that is both quantitatively and qualitatively different from what is predicted or possible deterministically. We further demonstrate that the noise required to produce these distinct properties can itself be caused by a set of auxiliary chemical reactions, making it feasible for biological systems of sufficient complexity to generate such behavior internally. This new stochastic dynamics then serves to confer additional functional modalities on the enzymatic futile cycle mechanism that include stochastic amplification and signaling, the characteristics of which could be controlled by both the type and parameters of the driving noise. Hence, such noise-induced phenomena may, among other roles, potentially offer a novel type of control mechanism in pathways that contain these cycles and the like units. In particular, observations of endogenous or externally driven noise-induced dynamics in regulatory networks may thus provide additional insight into their topology, structure, and kinetics. network motif | signal transduction | chemical reaction | synthetic biology | systems biology

  16. Noise-Induced Sleep Disturbance in Residences Near Two Civil Airports

    Science.gov (United States)

    Fidell, Sanford; Howe, Richard R.; Tabachnick, Barbara G.; Pearsons, Karl S.; Sneddon, Matthew D.

    1995-01-01

    A large-scale field study of noise-induced sleep disturbance was conducted in the vicinities of Stapleton International Airport (DEN) and Denver International Airport (DIA) in anticipation of the closure of the former and opening of the latter. Both indoor and outdoor measurements of aircraft and other nighttime noises were made during four time periods. Measurements were made in 57 homes located as close as feasible to the runway ends of the two airports. Sleep disturbance was measured by several indices of behaviorally confirmed awakening (button pushes upon awakening) and body movement (as measured with wrist-worn actimeters). A total of 2717 subject-nights of observations were made over the course of the study. Although average noise event levels measured outdoors decreased markedly at DEN after closure of the airport and increased slightly at DIA after its opening, indoor noise event levels varied much less in homes near both airports. No large differences were observed in noise-induced sleep disturbance at either airport. Indoor sound exposure levels of noise events were, however, closely related to and good predictors of actimetrically defined motility and arousal.

  17. Prevention of noise-induced hearing loss in the Canadian military.

    Science.gov (United States)

    Pelausa, E O; Abel, S M; Simard, J; Dempsey, I

    1995-10-01

    A prospective study was undertaken to investigate the development of noise-induced hearing loss in Canadian military recruits, and to assess the effectiveness of the hearing conservation program currently in place. The participants were 134 men and women, 20 to 30 years of age, employed in four trades, three of these (infantry, artillery, and armour) associated with high noise levels. The data comprised audiometric measurements made at the time of entry and after 3 years of employment, and responses to a questionnaire mainly relating to noise exposure in the workplace and during leisure activities, and the utilization of personal hearing protective devices. The findings showed that group audiograms at entry and at the 3-year recall were characterized by a 6-kHz notch that was indicative of noise-induced hearing loss, although mean threshold values were within normal limits. By the 3-year recall, 11% of the infantry had sustained a mild-to-moderate hearing loss in the left ear, greater than 25-dB HL, that was consistent with the use of small-calibre weapons. Responses to the questionnaire indicated that, while subjects appreciated the potential benefit of wearing hearing protectors, instructions in their proper use and education on the hazards of noise exposure were poor. The results suggested methods to strengthen the existing scheme for hearing conservation to further minimize risk.

  18. Combination therapy using antioxidants and low level laser therapy (LLLT) on noise induced hearing loss (NIHL)

    Science.gov (United States)

    Chang, So-Young; Lim, Sung Kyu; Lee, Min young; Chung, Phil-Sang; Jung, Jae-Yun; Rhee, Chung-Ku

    2016-02-01

    One of the most common factors that cause hearing disorders is noise trauma. Noise is an increasing hazard and it is pervasive, which makes it difficult to take precautions and prevent noise-induced hearing loss (NIHL). The prevalence of hearing loss among factory workers to be 42 %[1]. Ocupational noise induced hearing loss (ONIHL) continues to be a significant occupational hazard. ONIHL is permanent and may cause significant disability, for which there currently exists no cure, but is largely preventable. More than 30 million Americans are potentially exposed to hazardous noise levels in occupations such as transportation, construction, and coal mining, as well as recreationally. In the mainstream setting, exposure avoidance strategies aimed to reduce the incidence of ONIHL remain the focus of public health and occupational medicine approaches[2]. In military conditions this is most often caused by such things as explosions, blasts, or loud noises from vehicles ranging from 100 to 140 dB[3] and military weapons generating approximately 140-185 dB peak sound pressure levels[4].

  19. Medical surveillance of occupational Noise Induced Hearing Loss (NIHL) at RAPS hospital

    International Nuclear Information System (INIS)

    Manuwal, A.K.; Ganesan, S.

    2009-01-01

    Full text: One of the most challenging roles of a Certifying Surgeon is to act as catalyst for change. This paper is a presentation of the impact of such an effort. Noise is the insidious of all industrial pollutants, involving every industry and causing severe hearing loss. Exposure to excessive noise is the major avoidable cause of permanent hearing impairment. Noise - induced hearing loss (NIHL) is bilateral and symmetrical, usually affecting the higher frequencies 3 k, 4 k or 6 kHz ) and then spreading to the lower frequencies (0.5 k,1 k or 2 kHz). The major health effects are lack of concentration, irritation, fatigue, headache, sleep disturbances etc. Hearing protectors should be used when engineering controls and work practices are not feasible for reducing noise exposure to safe levels. Ear muffs, ear plugs and ear canal caps are the main types of hearing protectors. Awareness should be created among workers about the harmful effects of noise on hearing and other body systems by implementing compulsory education noise conservation programmes. The practice followed at RAPS Hospital for medical surveillance of Occupational Noise Induced Hearing Loss is being briefed

  20. Occupational noise-induced hearing loss in Indian steel industry workers: an exploratory study.

    Science.gov (United States)

    Singh, Lakhwinder Pal; Bhardwaj, Arvind; Deepak, Kishore Kumar

    2013-04-01

    The present study focused on exploring the current level of hearing protection and subsequently determined the prevalence of occupational noise-induced hearing loss among casting and forging industry workers. The casting and forging industry provides employment to a significant portion of the population. The level of hearing protection was assessed through questionnaire survey of 572 workers. Out of these workers, 165 and another control group of 57 participants were assessed by formal audiometry. Audiometric tests were conducted at frequencies of 1.0 KHz to 8.0 KHz.The occurrence of hearing loss was determined on the basis of a hearing threshold level with a low fence of 25 dB. Student's test and ANOVA were used to compare the various groups; a p value steel industry are highly exposed to occupational noise. The majority of workers are not protected from noise-induced hearing loss. There is a need to provide special ear protectors for workers engaged in forging. A complete hearing protection program, including training, audiometry, job rotation, and the use of hearing protection devices, needs to be introduced.

  1. [Analysis on occupational noise-induced hearing loss of different type workers in underground mining].

    Science.gov (United States)

    Liu, Q C; Duo, C H; Wang, Z; Yan, K; Zhang, J; Xiong, W; Zhu, M

    2017-11-20

    Objective: To investigate hearing loss status of blasters, drillers mechanics and so on in underground mining, and put forward suggestion diagnosis of occupational explosive deafness and occupational deafness. Methods: Underground excavation workers in a metal mine were recruited in this study, those with a history of ear disease and non-occupational deafness were all excluded. Finally, the features of pure tone audiometry of 459 noise-exposed workers were analyzed. Results: High-frequency hearing loss occurred on 351workers and the positive detection rate was 74.29%, workers who had both high-frequency and linguistic frequency hearing loss were 51 and the positive detection rate was 11.11%. The positive detection of high-frequency hearing loss in right ear (χ(2)=9.427 and P = 0.024) and in left ear (χ(2)=14.375, P =0.002) was significantly different between different exposure age groups. The positive detection of high-frequency hearing loss of driving group was the highest, followed by blasting group, mining group and machine repair group. The characteristics of the hearing loss caused by drilling noise of the blasting workers with no accident occurred were in line with that of noise-induced hearing loss. Conclusion: The diagnosis grading should be carried out according to the diagnostic criteria of occupational noise-induced deafness for the employees who engaged in the blasting operation with no record of blast accident.

  2. Noise-induced chaos and basin erosion in softening Duffing oscillator

    International Nuclear Information System (INIS)

    Gan Chunbiao

    2005-01-01

    It is common for many dynamical systems to have two or more attractors coexist and in such cases the basin boundary is fractal. The purpose of this paper is to study the noise-induced chaos and discuss the effect of noises on erosion of safe basin in the softening Duffing oscillator. The Melnikov approach is used to obtain the necessary condition for the rising of chaos, and the largest Lyapunov exponent is computed to identify the chaotic nature of the sample time series from the system. According to the Melnikov condition, the safe basins are simulated for both the deterministic and the stochastic cases of the system. It is shown that the external Gaussian white noise excitation is robust for inducing the chaos, while the external bounded noise is weak. Moreover, the erosion of the safe basin can be aggravated by both the Gaussian white and the bounded noise excitations, and fractal boundary can appear when the system is only excited by the random processes, which means noise-induced chaotic response is induced

  3. High Frequency Infrasonic Radiation from the 11 March 2011 Tohoku Mw 9.0 Earthquake

    Science.gov (United States)

    Walker, K. T.; Le Pichon, A.; Degroot-Hedlin, C. D.; Che, I.

    2011-12-01

    The tragic March 11 Mw 9.0 Tohoku earthquake ruptured the Wadati-Benioff zone beneath northeast Japan, generating a damaging seismic wavetrain and triggering a tsunami that devastated the nearby coastal areas. Centroid moment tensors, aftershocks, and the geometry of the trench suggest the rupture occurred on a plane roughly 400 km long by 200 km wide. Because the Earth's surface is effectively a speaker, the seismic wavetrain generated infrasonic emissions from northeast Japan that were recorded by seven infrasound arrays within 5600 km of the epicenter. Using a time progressive beamforming method and the Progressive Multi-Channel Correlation method, we detect and calculate back azimuths for the 0.3 to 3 Hz infrasonic signals at these stations. After application of predicted wind corrections, these back azimuths point to Honshu and Hokkaido, with the majority of detections illuminating a north-south elongated area near Sendai, where the USGS ShakeMap predicts the greatest intensity of surface shaking. An array near Tokyo (IS30) provides the first recording of locally generated infrasound from a very large dip-slip earthquake. At IS30 a six-minute arrival in the 0.3 to 1.5 Hz band is observed from northeast Japan spanning an 18° back azimuth range. Two shorter events originate from a source to the west, likely Mt. Fuji. Using constraints from propagation modeling, we back project the infrasonic amplitudes recorded at IS30 to a relatively localized area. The maximum amplitude of 1 Pa originates from surface shaking along the coast. This location is also just west of the epicenter and adjacent to the location of maximum P-wave radiation from back projection studies. Noise at IS30 after the mainshock limits the detection of additional signals. A more pronounced infrasonic wavetrain at IS44 (Kamchatka) illuminates the entire Honshu and Hokkaido region, especially along the east coast near Sendai. In agreement with propagation modeling predictions using global

  4. Noise-Induced Loss of Hair Cells and Cochlear Synaptopathy Are Mediated by the Activation of AMPK

    Science.gov (United States)

    Hill, Kayla; Yuan, Hu; Wang, Xianren

    2016-01-01

    Noise-induced hearing loss (NIHL) is a major unresolved public health problem. Here, we investigate pathomechanisms of sensory hair cell death and suggest a novel target for protective intervention. Cellular survival depends upon maintenance of energy homeostasis, largely by AMP-activated protein kinase (AMPK). In response to a noise exposure in CBA/J mice, the levels of phosphorylated AMPKα increased in hair cells in a noise intensity-dependent manner. Inhibition of AMPK via siRNA or the pharmacological inhibitor compound C attenuated noise-induced loss of outer hair cells (OHCs) and synaptic ribbons, and preserved auditory function. Additionally, noise exposure increased the activity of the upstream AMPK kinase liver kinase B1 (LKB1) in cochlear tissues. The inhibition of LKB1 by siRNA attenuated the noise-increased phosphorylation of AMPKα in OHCs, reduced the loss of inner hair cell synaptic ribbons and OHCs, and protected against NIHL. These results indicate that noise exposure induces hair cell death and synaptopathy by activating AMPK via LKB1-mediated pathways. Targeting these pathways may provide a novel route to prevent NIHL. SIGNIFICANCE STATEMENT Our results demonstrate for the first time that the activation of AMP-activated protein kinase (AMPK) α in sensory hair cells is noise intensity dependent and contributes to noise-induced hearing loss by mediating the loss of inner hair cell synaptic ribbons and outer hair cells. Noise induces the phosphorylation of AMPKα1 by liver kinase B1 (LKB1), triggered by changes in intracellular ATP levels. The inhibition of AMPK activation by silencing AMPK or LKB1, or with the pharmacological inhibitor compound C, reduced outer hair cell and synaptic ribbon loss as well as noise-induced hearing loss. This study provides new insights into mechanisms of noise-induced hearing loss and suggests novel interventions for the prevention of the loss of sensory hair cells and cochlear synaptopathy. PMID:27413159

  5. Epidemiology of noise-induced tinnitus and the attitudes and beliefs towards noise and hearing protection in adolescents.

    Directory of Open Access Journals (Sweden)

    Annick Gilles

    Full Text Available BACKGROUND AND OBJECTIVES: Previous research showed an increase of noise-induced symptoms in adolescents. Permanent tinnitus as a consequence of loud music exposure is usually considered as noise-induced damage. The objective was to perform an epidemiological study in order to obtain prevalence data of permanent noise-induced tinnitus as well as temporary tinnitus following noise exposure in a young population. In addition the attitudes and beliefs towards noise and hearing protection were evaluated in order to explain the use/non-use of hearing protection in a young population. METHODS: A questionnaire was completed by 3892 high school students (mean age: 16.64 years old, SD: 1.29 years. The prevalence of temporary and permanent tinnitus was assessed. In addition the 'Youth Attitudes to Noise Scale' and the 'Beliefs About Hearing Protection and Hearing Loss' were used in order to assess the attitudes and beliefs towards noise and hearing protection respectively. RESULTS: The prevalence of temporary noise-induced tinnitus and permanent tinnitus in high school students was respectively 74.9% and 18.3%. An increasing prevalence of temporary tinnitus with age was present. Most students had a 'neutral attitude' towards loud music and the use of hearing protection was minimal (4.7%. The limited use of hearing protection is explained by a logistic regression analysis showing the relations between certain parameters and the use of hearing protection. CONCLUSIONS: Despite the very high prevalence of tinnitus in such a young population, the rate of hearing protection use and the knowledge about the risks of loud music is extremely low. Future preventive campaigns should focus more on tinnitus as a warning signal for noise-induced damage and emphasize that also temporary symptoms can result in permanent noise-induced damage.

  6. Activity of coenzyme Q 10 (Q-Ter multicomposite) on recovery time in noise-induced hearing loss.

    Science.gov (United States)

    Staffa, Paola; Cambi, Jacopo; Mezzedimi, Chiara; Passali, Desiderio; Bellussi, Luisa

    2014-01-01

    A potential consequence of exposure to noise is a temporary reduction in auditory sensitivity known as temporary threshold shift (TTS), which mainly depends on the intensity and duration of exposure to the noise. Recovery time is related to the amount of initial hearing loss, and the most recovery takes place during the first 15 min following exposure. This study evaluated the efficacy in otoprotection against noise-induced hearing loss of an orally administrated food supplement containing coenzyme Q 10 -Ter. This water-soluble formulation of coenzyme Q 10 shows better bioavailability than the native form and has been found to have a protective effect on outer hair cells after exposure to noise in animal models. Thirty volunteers were enrolled, and the right ear of each subject was exposed to a narrow-band noise centered at 3 kHz for 10 min at the intensity of 90 dB HL. In the 30 subjects enrolled, TTS was evaluated after 2, 15, and 30 min and the recovery time was recorded in each subject. The longest recovery time was 45 min. Among the 18 subjects who underwent a second test after treatment with Q-Ter, the mean recovery time was 31.43 min. The results of the present study show that 30 days' treatment with Q-Ter can aid faster recovery after exposure to noise (P < 0.0001). The reduction in the recovery time following treatment can be explained by Q-Ter-mediated improvement of the outer hair cells' response to oxidative stress.

  7. Concorde noise-induced building vibrations: International Airport Dulles. [studies by Langley Research Center

    Science.gov (United States)

    Mayes, W. H.; Scholl, H. F.; Stephens, D. G.; Holliday, B. G.; Deloach, R.; Finley, T. D.; Holmes, H. K.; Lewis, R. B.; Lynch, J. W.

    1977-01-01

    A series of studies were conducted to assess the noise-induced building vibrations associated with Concorde operations. The vibration levels of windows, walls, and floors were measured along with the associated noise levels of Concorde, subsonic aircraft and some nonaircraft events. Test sites included Sully Plantation which is adjacent to Dulles International Airport and three residential homes located in Montgomery County, Maryland. The measured vibration response levels due to Concorde operations were found to be: (1) higher than the levels due to other aircraft, (2) less than the levels due to certain household events which involve direct impulsive loading such as door and window closing, (3) less than criteria levels for building damage, and (4) comparable to levels which are perceptible to people.

  8. Could driving safety be compromised by noise exposure at work and noise-induced hearing loss?

    Science.gov (United States)

    Picard, Michel; Girard, Serge André; Courteau, Marilène; Leroux, Tony; Larocque, Richard; Turcotte, Fernand; Lavoie, Michel; Simard, Marc

    2008-10-01

    A study was conducted to verify if there is an association between occupational noise exposure, noise-induced hearing loss and driving safety expanding on previous findings by Picard, et al. (2008) that the two factors did increase accident risk in the workplace. This study was made possible when driving records of all Quebec drivers were made available by the Societe de l'assurance automobile du Quebec (SAAQ is the state monopoly responsible for the provision of motor vehicle insurance and the compensation of victims of traffic accidents). These records were linked with personal records maintained by the Quebec National Institute of Public Health as part of its mission to prevent noise induced hearing loss in the workplace. Individualized information on occupational noise exposure and hearing sensitivity was available for 46,030 male workers employed in noisy industries who also held a valid driver's permit. The observation period is of five years duration, starting with the most recent audiometric examination. The associations between occupational noise exposure levels, hearing status, and personal driving record were examined by log-binomial regression on data adjusted for age and duration of exposure. Daily noise exposures and bilateral average hearing threshold levels at 3, 4, and 6 kHz were used as independent variables while the dependent variables were 1) the number of motor vehicle accidents experienced by participants during the study period and 2) participants' records of registered traffic violations of the highway safety code. The findings are reported as prevalence ratios (PRs) with their 95% confidence intervals (CIs). Attributable numbers of events were computed with the relevant PRs, lesser-noise, exposed workers and those with normal hearing levels making the group of reference. Adjusting for age confirmed that experienced workers had fewer traffic accidents. The data show that occupational noise exposure and hearing loss have the same effect on

  9. On common noise-induced synchronization in complex networks with state-dependent noise diffusion processes

    Science.gov (United States)

    Russo, Giovanni; Shorten, Robert

    2018-04-01

    This paper is concerned with the study of common noise-induced synchronization phenomena in complex networks of diffusively coupled nonlinear systems. We consider the case where common noise propagation depends on the network state and, as a result, the noise diffusion process at the nodes depends on the state of the network. For such networks, we present an algebraic sufficient condition for the onset of synchronization, which depends on the network topology, the dynamics at the nodes, the coupling strength and the noise diffusion. Our result explicitly shows that certain noise diffusion processes can drive an unsynchronized network towards synchronization. In order to illustrate the effectiveness of our result, we consider two applications: collective decision processes and synchronization of chaotic systems. We explicitly show that, in the former application, a sufficiently large noise can drive a population towards a common decision, while, in the latter, we show how common noise can synchronize a network of Lorentz chaotic systems.

  10. Personal cassette players ('Walkman'). Do they cause noise-induced hearing loss?

    Science.gov (United States)

    Turunen-Rise, I; Flottorp, G; Tvete, O

    1991-01-01

    Playing selected types of music on five different personal cassette players (PCPs) and using different gain (volume) settings, A-weighted maximum and equivalent sound pressure levels (SPLs) were measured on KEMAR (Knowles Electronics Manikin for Acoustic Research). The octave band SPLs were measured on KEMAR ear and transformed to field values in order to compare measured values with the Norwegian noise risk criteria. Temporary threshold shifts (TTS) measured in 6 subjects after listening to two different pop music cassettes on one PCP in two separate sessions, are presented. Based upon these studies we conclude that the risk of acquiring permanent noise-induced hearing loss (NIHL) from use of PCP is very small for what we found to be normal listening conditions.

  11. Noise-Induced Hearing Loss (NIHL: literature review with a focus on occupational medicine

    Directory of Open Access Journals (Sweden)

    Metidieri, Mirella Melo

    2013-04-01

    Full Text Available According to the Ministry of Health (2006, Noise-Induced Hearing Loss (NIHL is hearing loss caused by prolonged exposure to noise. It is characterized as sensorineural hearing loss and is usually bilateral, irreversible, and progressive while the exposure to noise continues. A NIHL is a predictable and preventable disease with an epidemiologically relevant prevalence in urban communities. The hearing loss begins and predominates in the frequencies of 3, 4, and 6 kHz and eventually progresses to 8, 2, 1, 0.5, and 0.25 kHz. In Brazil, regulatory standard 15 limits the exposure to continuous noise to no more than 4 hours' exposure to 90 dBA and a maximum level of 85 dB for a full 8-hour working period. As NIHL is a preventable and predictable disease, preventive action by professionals may be able to change the prevalence of hearing loss in noisy environments.

  12. Calculation of the ex-core neutron noise induced by fuel vibrations in PWRs

    International Nuclear Information System (INIS)

    Tran Hoai Nam; Cao Van Chung; Hoang Thanh Phi Hung; Hoang Van Khanh

    2015-01-01

    Calculation of the neutron noise induced by fuel assembly vibrations in two pressurized water reactor (PWR) cores has been performed to investigate the effect of cycle burnup on the properties of the ex-core detector noise. Pendular vibrations of individual fuel assemblies were assumed to occur at different locations in the core. The auto power spectra density (APSD) of the ex-core detector noise was evaluated with the assumption of stochastic vibrations along a random two-dimensional trajectory. The results show that no general monotonic variation of APSD was found. The increase of APSD occurs predominantly for peripheral assemblies. Assuming simultaneous vibrations of a number of fuel assemblies uniformly distributed over the core with the more realistic perturbation model, the effect of the peripheral assemblies will dominate and the increase of the amplitude of the ex-core neutron noise with burnup can be confirmed. (author)

  13. Noise-Induced Hearing Loss (NIHL): literature review with a focus on occupational medicine.

    Science.gov (United States)

    Metidieri, Mirella Melo; Rodrigues, Hugo Fernandes Santos; Filho, Francisco José Motta Barros de Oliveira; Ferraz, Daniela Pereira; Neto, Antonio Fausto de Almeida; Torres, Sandro

    2013-04-01

    According to the Ministry of Health (2006), Noise-Induced Hearing Loss (NIHL) is hearing loss caused by prolonged exposure to noise. It is characterized as sensorineural hearing loss and is usually bilateral, irreversible, and progressive while the exposure to noise continues. A NIHL is a predictable and preventable disease with an epidemiologically relevant prevalence in urban communities. The hearing loss begins and predominates in the frequencies of 3, 4, and 6 kHz and eventually progresses to 8, 2, 1, 0.5, and 0.25 kHz. In Brazil, regulatory standard 15 limits the exposure to continuous noise to no more than 4 hours' exposure to 90 dBA and a maximum level of 85 dB for a full 8-hour working period. As NIHL is a preventable and predictable disease, preventive action by professionals may be able to change the prevalence of hearing loss in noisy environments.

  14. Noise-induced multistability in the regulation of cancer by genes and pseudogenes

    Energy Technology Data Exchange (ETDEWEB)

    Petrosyan, K. G., E-mail: pkaren@phys.sinica.edu.tw [Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan (China); Hu, Chin-Kun, E-mail: huck@phys.sinica.edu.tw [Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan (China); National Center for Theoretical Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Business School, University of Shanghai for Science and Technology, Shanghai 200093 (China)

    2016-07-28

    We extend a previously introduced model of stochastic gene regulation of cancer to a nonlinear case having both gene and pseudogene messenger RNAs (mRNAs) self-regulated. The model consists of stochastic Boolean genetic elements and possesses noise-induced multistability (multimodality). We obtain analytical expressions for probabilities for the case of constant but finite number of microRNA molecules which act as a noise source for the competing gene and pseudogene mRNAs. The probability distribution functions display both the global bistability regime as well as even-odd number oscillations for a certain range of model parameters. Statistical characteristics of the mRNA’s level fluctuations are evaluated. The obtained results of the extended model advance our understanding of the process of stochastic gene and pseudogene expressions that is crucial in regulation of cancer.

  15. Occupational noise-induced hearing loss among workers at Jomo Kenyatta International Airport, Nairobi.

    Science.gov (United States)

    Anino, J O; Afullo, A; Otieno, F

    2010-02-01

    Occupational noise induced hearing loss (NIHL) occurs among workers exposed to excessive amounts of noise for long durations. The average level of noise in some locations at Jomo Kenyatta International Airport (JKIA) was above the safe limit of 85dB hence workers were thought to be at risk. To determine the occurrence and socio demographic attributes for NIHL at JKIA. Cross sectional descriptive study. Jomo Kenyatta International Airport, Nairobi, Kenya. Mean age of respondents was 37 years with range 22 to 62, SD 8.98. Mean duration of exposure to noise was 10.7 years with range 1 to 40, SD 8.15. Prevalence of NIHL was 15.3%, with ground crew at 14.8% and air crew 16.1%. Ground crew had significantly poorer mean hearing threshold level at 3, 4 and 6 kHz than air crew (p = 0.015). Male workers were affected more than female counterparts with a male to female ratio of 4:3. 97% of those affected were non-managers, 3% managers while 68% of those affected resided in Embakasi Division close to the airport. Hearing threshold level at 4 kHz deteriorated with increasing age whereby those aged 50 years and above had a 13.7 times higher relative risk than those aged 20 to 29 years. Duration of exposure more than 10 years also had significantly higher risk (p hearing loss at 4 kHz. Occupational noise induced hearing loss occurs atJKIA and that ground crew and older workers are more vulnerable. We recommend that prevention programmes be put in place.

  16. Noise-induced nitrotyrosine increase and outer hair cell death in guinea pig cochlea.

    Science.gov (United States)

    Han, Wei-ju; Shi, Xiao-rui; Nuttall, Alfred

    2013-01-01

    Modern research has provided new insights into the biological mechanisms of noise-induced hearing loss, and a number of studies showed the appearance of increased reactive oxygen species (ROS) and reactive nitrogen species (RNS) during and after noise exposure. This study was designed to investigate the noise exposure induced nitrotyrosine change and the mechanism of outer hair cells death in guinea pig cochlea. Thirty guinea pigs were used in this study. The experimental animals were either exposed for 4 hours per day to broadband noise at 122 dB SPL (A-weighted) for 2 consecutive days or perfused cochleae with 5 mg/ml of the SIN1 solutions, an exogenous NO and superoxide donor, for 30 minutes. Then the cochleae of the animals were dissected. Propidium iodide (PI), a DNA intercalating fluorescent probe, was used to trace morphological changes in OHC nuclei. The distribution of nitrotyrosine (NT) in the organ of Corti and the cochlear lateral wall tissue from the guinea pigs were examined using fluorescence immunohistochemistry method. Whole mounts of organ of Corti were prepared. Morphological and fluorescent changes were examined under a confocal microscope. Either after noise exposure or after SIN1 perfusion, outer hair cells (OHCs) death with characteristics of both apoptotic and necrotic degradation appeared. Nitrotyrosine immunolabeling could be observed in the OHCs from the control animals. After noise exposure, NT immunostaining became much greater than the control animals in OHCs. The apoptotic OHC has significant increase of nitrotyrosine in and around the nucleus following noise exposure. In the normal later wall of cochleae, relatively weak nitrotyrosine immunolabeling could be observed. After noise exposure, nitrotyrosine immunoactivity became stronger in stria vascularis. Noise exposure induced increase of nitrotyrosine production is associated with OHCs death suggesting reactive nitrogen species participation in the cochlear pathophysiology of noise-induced

  17. Observed seismic and infrasonic signals around the Hakone volcano -Discussion based on a finite-difference calculation-

    Science.gov (United States)

    Wakamatu, S.; Kawakata, H.; Hirano, S.

    2017-12-01

    Observation and analysis of infrasonic waves are important for volcanology because they could be associated with mechanisms of volcanic tremors and earthquakes (Sakai et al., 2000). Around the Hakone volcano area, Japan, infrasonic waves had been observed many times in 2015 (Yukutake et al., 2016, JpGU). In the area, seismometers have been installed more than microphones, so that analysis of seismograms may also contribute to understanding some characteristics of the infrasonic waves. In this study, we focused on the infrasonic waves on July 1, 2015, at the area and discussed their propagation. We analyzed the vertical component of seven seismograms and two infrasound records; instruments for these data have been installed within 5 km from the vent emerged in the June 2015 eruption(HSRI, 2015). We summarized distances of the observation points from the vent and appearance of the signals in the seismograms and the microphone records in Table 1. We confirmed that, when the OWD microphone(Fig1) observed the infrasonic waves, seismometers of the OWD and the KIN surface seismic stations(Fig1) recorded pulse-like signals repeatedly while the other five buried seismometers did not. At the same time, the NNT microphone(Fig1) recorded no more than unclear signals despite the shorter distance to the vent than that of the KIN station. We found that the appearance of pulse-like signals at the KIN seismic station usually 10-11 seconds delay after the appearance at the OWD seismic station. The distance between these two stations is 3.5km, so that the signals in seismograms could represent propagation of the infrasonic waves rather than the seismic waves. If so, however, the infrasound propagation could be influenced by the topography of the area because the signals are unclear in the NNT microphone record.To validate the above interpretation, we simulated the diffraction of the infrasonic waves due to the topography. We executed a 3-D finite-difference calculation by

  18. Evaluation of the current practices of noise-induced hearing loss (NIHL) awareness training in the South African mining industry

    CSIR Research Space (South Africa)

    Edwards, AL

    2015-01-01

    Full Text Available This study aimed to evaluate the current practices in relation to best practice criteria and make recommendations for improvements to noise-induced hearing loss (NIHL) awareness training in the South African mining industry. A survey tool based...

  19. The Physiological Bases of Hidden Noise-Induced Hearing Loss: Protocol for a Functional Neuroimaging Study.

    Science.gov (United States)

    Dewey, Rebecca Susan; Hall, Deborah A; Guest, Hannah; Prendergast, Garreth; Plack, Christopher J; Francis, Susan T

    2018-03-09

    procedures for hidden hearing loss, enabling early identification of noise-induced auditory damage via the detection of changes in central auditory processing. Consequently, this will generate the opportunity to give personalized advice regarding provision of ear defense and monitoring of further damage, thus reducing the incidence of noise-induced hearing loss. ©Rebecca Susan Dewey, Deborah A Hall, Hannah Guest, Garreth Prendergast, Christopher J Plack, Susan T Francis. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 09.03.2018.

  20. Evidence of noise-induced hearing loss in young people studying popular music.

    Science.gov (United States)

    Barlow, Christopher

    2011-06-01

    The number of students studying popular music, music technology, and sound engineering courses at both school and university to has increased rapidly in the last few years. These students are generally involved in music-making/recording and listening to a high level, usually in environments with amplified music. Recent studies have shown that these students are potentially exposed to a high risk of noise-induced hearing loss (NIHL( and are not covered by the same regulatory framework as employees. This study examined the pure tone air conduction hearing thresholds of 50 undergraduate students, including recent school leavers, on a range of popular music courses, to assess if there was evidence of hearing loss. Forty-four percent of students showed evidence of audiometric notch at 4-6 kHz, and 16% were classified under the UK Occupational Health and Safety guidelines as exhibiting mild hearing loss. Instance of audiometric notch was considerably higher than reported from studies of the general population but was around the same level or lower than that reported from studies of "traditional" music courses and conservatoires, suggesting no higher risk for popular music students than for "classical" music students. No relationship with age was present, suggesting that younger students were as likely to exhibit audiometric notch as mature students. This indicates that these students may be damaging their hearing through leisure activities while still at school, suggesting a need for robust education measures to focus on noise exposure of young people.

  1. Numerical investigation on vibration and noise induced by unsteady flow in an axial-flow pump

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Eryun; Ma, Zui Ling; Yang, Ai Ling; Nan, Guo Fang [School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai (China); Zhao, Gai Ping [School of Medical Instruments and Food Engineering, University of Shanghai for Science and Technology, Shanghai (China); Li, Guo Ping [Shanghai Marine Equipment Research Institute, Shanghai (China)

    2016-12-15

    Full-scale structural vibration and noise induced by flow in an axial-flow pump was simulated by a hybrid numerical method. An unsteady flow field was solved by a large eddy simulation-based computational fluid dynamics commercial code, Fluent. An experimental validation on pressure fluctuations was performed to impose an appropriate vibration exciting source. The consistency between the computed results and experimental tests were interesting. The modes of the axial-flow pump were computed by the finite element method. After that, the pump vibration and sound field were solved using a coupled vibro-acoustic model. The numerical results indicated that the the blade-passing frequency was the dominant frequency of the vibration acceleration of the pump. This result was consistent with frequency spectral characteristics of unsteady pressure fluctuation. Finally, comparisons of the vibration acceleration between the computed results and the experimental test were conducted. These comparisons validated the computed results. This study shows that using the hybrid numerical method to evaluate the flow-induced vibration and noise generated in an axial-flow pump is feasible.

  2. Macrophage recruitment, but not interleukin 1 beta activation, enhances noise-induced hearing damage.

    Science.gov (United States)

    Mizushima, Yu; Fujimoto, Chisato; Kashio, Akinori; Kondo, Kenji; Yamasoba, Tatsuya

    2017-11-18

    It has been suggested that macrophages or inflammatory monocytes participate in the pathology of noise-induced hearing loss (NIHL), but it is unclear how extensively these cells contribute to the development of temporary and/or permanent NIHL. To address this question, we used clodronate liposomes to deplete macrophages and monocytes. After clodronate liposome injection, mice were exposed to 4-kHz octave band noise at 121 dB for 4 h. Compared to vehicle-injected controls, clodronate-treated mice exhibited significantly reduced permanent threshold shifts at 4 and 8 kHz and significantly smaller outer hair cell losses in the lower-apical cochlear turn. Following noise exposure, the stria vascularis had significantly more cells expressing the macrophage-specific protein F4/80, and this effect was significantly suppressed by clodronate treatment. These F4/80-positive cells expressed interleukin 1 beta (IL-1β), which noise exposure activated. However, IL-1β deficient mice did not exhibit significant resistance to intense noise when compared to wild-type mice. These findings suggest that macrophages that enter the cochlea after noise exposure are involved in NIHL, whereas IL-1β inhibition does not reverse this cochlear damage. Therefore, macrophages may be a promising therapeutic target in human sensorineural hearing losses such as NIHL. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Characteristic of Noise-induced Hearing Loss among Workers in Construction Industries

    Science.gov (United States)

    Naadia Mazlan, Ain; Yahya, Khairulzan; Haron, Zaiton; Amsharija Mohamed, Nik; Rasib, Edrin Nazri Abdul; Jamaludin, Nizam; Darus, Nadirah

    2018-03-01

    Noise-induced hearing loss (NIHL) is among the most common occupational disease in industries. This paper investigates NIHL in construction related industries in Malaysia with particular emphasis on its relation with risk factors. The objectives of this research were to (1) quantify the prevalence of NIHL in construction related industries, and (2) assess the relationship between hearing loss and risk factors and it's characteristic. The study was conducted using 110 NIHL compensation record collected from Social Security Organisation (SOCSO), Malaysia. Risk factors namely area noise, age, temperature, smoking habit, hobby, diabetic and cardiovascular disease were identified and analysed. Results showed that there was no direct relationship between area noise with hearing impairment while there was only low relationship between age and hearing impairment. The range for area noise and age were between 70 to 140 dB(A) and 20 to 70 years, respectively. The other risk factors classified as categorical data and analysed using frequency method. Grade of impairment does not depend solely on area noise but also in combination with age and other risk factors. Characteristic of NIHL prevailed in construction related industries were presented using scatterplots and can serve as a references for future hazard control on site.

  4. Noise-induced phase space transport in two-dimensional Hamiltonian systems.

    Science.gov (United States)

    Pogorelov, I V; Kandrup, H E

    1999-08-01

    First passage time experiments were used to explore the effects of low amplitude noise as a source of accelerated phase space diffusion in two-dimensional Hamiltonian systems, and these effects were then compared with the effects of periodic driving. The objective was to quantify and understand the manner in which "sticky" chaotic orbits that, in the absence of perturbations, are confined near regular islands for very long times, can become "unstuck" much more quickly when subjected to even very weak perturbations. For both noise and periodic driving, the typical escape time scales logarithmically with the amplitude of the perturbation. For white noise, the details seem unimportant: Additive and multiplicative noise typically have very similar effects, and the presence or absence of a friction related to the noise by a fluctuation-dissipation theorem is also largely irrelevant. Allowing for colored noise can significantly decrease the efficacy of the perturbation, but only when the autocorrelation time, which vanishes for white noise, becomes so large that there is little power at frequencies comparable to the natural frequencies of the unperturbed orbit. Similarly, periodic driving is relatively inefficient when the driving frequency is not comparable to these natural frequencies. This suggests that noise-induced extrinsic diffusion, like modulational diffusion associated with periodic driving, is a resonance phenomenon. The logarithmic dependence of the escape time on amplitude reflects the fact that the time required for perturbed and unperturbed orbits to diverge a given distance scales logarithmically in the amplitude of the perturbation.

  5. [Protective effect of indirect activator of calcium pump on noise-induced hearing loss].

    Science.gov (United States)

    Liu, Jun; Yu, Ning; Han, Dongyi; Yang, Weiyan; Li, Xingqi

    2002-12-01

    To investigate the possible protective effect of phorbol-12-myristate-13-acetate (PMA), an activator of protein kinase C (PKC) and indirect activator of Ca2+ pump, on noise-induced hearing loss (NIHL). Twenty guinea pigs were divided randomly into two groups, and then perfused with artificial perilymph solutions in one group and with artificial perilymph solutions containing 3 mumol/L PMA in the other one, respectively. All animals were exposed with 100 dB SPL white noise for 2 hours. Cochlear microphonics (CM) and compound action potential (CAP) were recorded from the round window (RW) before noise exposure and 2 hours after noise exposure. There was no significant difference in CAP threshold and CM amplitude between two groups before noise exposure. A significant difference was observed in CAP threshold and CM amplitude between two groups after noise exposure. The amplitude of CM decreased and the threshold of CAP increased in both group after noise exposure, but in the PMA group the decrease of the amplitude of CM was higher while the increase of threshold of CAP lower than that in control (P < 0.05). PMA might have partly protective effect on NIHL. These findings indirectly proved that intracellular Ca2+ overload might involve in the mechanism of NIHL.

  6. Falls risk and hospitalization among retired workers with occupational noise-induced hearing loss.

    Science.gov (United States)

    Girard, Serge André; Leroux, Tony; Verreault, René; Courteau, Marilène; Picard, Michel; Turcotte, Fernand; Baril, Julie

    2014-03-01

    This study sought to ascertain whether occupational noise-induced hearing loss (NIHL) increased the risk of falls requiring hospitalization among retired workers. The study population consisted of males (age ≥ 65) with an average occupational noise exposure of 30.6 years and whose mean bilateral hearing loss was 42.2 dB HL at 3, 4, and 6 kHz. Seventy-two retired workers admitted to hospitals after a fall were matched with 216 controls from the same industrial sectors. Conditional logistic regression models were used to estimate the risk (odds ratio; [OR]) of falls leading to hospitalization by NIHL categories. Results showed a relationship between severe NIHL (≥ 52.5 dB HL) and the occurrence of a fall (OR: 1.97, CI95%: 1.001-3.876). Reducing falls among seniors fosters the maintenance of their autonomy. There is a definite need to acquire knowledge about harmful effects of occupational noise to support the prevention of NIHL and ensure healthier workplaces.

  7. Implementation of a method to visualize noise-induced hearing loss in mass stranded cetaceans

    Science.gov (United States)

    Morell, Maria; Brownlow, Andrew; McGovern, Barry; Raverty, Stephen A.; Shadwick, Robert E.; André, Michel

    2017-02-01

    Assessment of the impact of noise over-exposure in stranded cetaceans is challenging, as the lesions that lead to hearing loss occur at the cellular level and inner ear cells are very sensitive to autolysis. Distinguishing ante-mortem pathology from post-mortem change has been a major constraint in diagnosing potential impact. Here, we outline a methodology applicable to the detection of noise-induced hearing loss in stranded cetaceans. Inner ears from two mass strandings of long-finned pilot whales in Scotland were processed for scanning electron microscopy observation. In one case, a juvenile animal, whose ears were fixed within 4 hours of death, revealed that many sensory cells at the apex of the cochlear spiral were missing. In this case, the absence of outer hair cells would be compatible with overexposure to underwater noise, affecting the region which transduces the lowest frequencies of the pilot whales hearing spectrum. Perfusion of cochlea with fixative greatly improved preservation and enabled diagnostic imaging of the organ of Corti, even 30 hours after death. This finding supports adopting a routine protocol to detect the pathological legacy of noise overexposure in mass stranded cetaceans as a key to understanding the complex processes and implications that lie behind such stranding events.

  8. Acoustic noise induces attention shifts and reduces foraging performance in three-spined sticklebacks (Gasterosteus aculeatus.

    Directory of Open Access Journals (Sweden)

    Julia Purser

    2011-02-01

    Full Text Available Acoustic noise is known to have a variety of detrimental effects on many animals, including humans, but surprisingly little is known about its impacts on foraging behaviour, despite the obvious potential consequences for survival and reproductive success. We therefore exposed captive three-spined sticklebacks (Gasterosteus aculeatus to brief and prolonged noise to investigate how foraging performance is affected by the addition of acoustic noise to an otherwise quiet environment. The addition of noise induced only mild fear-related behaviours--there was an increase in startle responses, but no change in the time spent freezing or hiding compared to a silent control--and thus had no significant impact on the total amount of food eaten. However, there was strong evidence that the addition of noise increased food-handling errors and reduced discrimination between food and non-food items, results that are consistent with a shift in attention. Consequently, noise resulted in decreased foraging efficiency, with more attacks needed to consume the same number of prey items. Our results suggest that acoustic noise has the potential to influence a whole host of everyday activities through effects on attention, and that even very brief noise exposure can cause functionally significant impacts, emphasising the threat posed by ever-increasing levels of anthropogenic noise in the environment.

  9. Simultaneous bilateral laser therapy accelerates recovery after noise-induced hearing loss in a rat model

    Directory of Open Access Journals (Sweden)

    Jae-Hun Lee

    2016-07-01

    Full Text Available Noise-induced hearing loss is a common type of hearing loss. The effects of laser therapy have been investigated from various perspectives, including in wound healing, inflammation reduction, and nerve regeneration, as well as in hearing research. A promising feature of the laser is its capability to penetrate soft tissue; depending on the wavelength, laser energy can penetrate into the deepest part of the body without damaging non-target soft tissues. Based on this idea, we developed bilateral transtympanic laser therapy, which uses simultaneous laser irradiation in both ears, and evaluated the effects of bilateral laser therapy on cochlear damage caused by noise overexposure. Thus, the purpose of this research was to assess the benefits of simultaneous bilateral laser therapy compared with unilateral laser therapy and a control. Eighteen Sprague-Dawley rats were exposed to narrow-band noise at 115 dB SPL for 6 h. Multiple auditory brainstem responses were measured after each laser irradiation, and cochlear hair cells were counted after the 15th such irradiation. The penetration depth of the 808 nm laser was also measured after sacrifice. Approximately 5% of the laser energy reached the contralateral cochlea. Both bilateral and unilateral laser therapy decreased the hearing threshold after noise overstimulation in the rat model. The bilateral laser therapy group showed faster functional recovery at all tested frequencies compared with the unilateral laser therapy group. However, there was no difference in the endpoint ABR results or final hair cell survival, which was analyzed histologically.

  10. The state of the art of predicting noise-induced sleep disturbance in field settings.

    Science.gov (United States)

    Fidell, Sanford; Tabachnick, Barbara; Pearsons, Karl S

    2010-01-01

    Several relationships between intruding noises (largely aircraft) and sleep disturbance have been inferred from the findings of a handful of field studies. Comparisons of sleep disturbance rates predicted by the various relationships are complicated by inconsistent data collection methods and definitions of predictor variables and predicted quantities. None of the relationships is grounded in theory-based understanding, and some depend on questionable statistical assumptions and analysis procedures. The credibility, generalizability, and utility of sleep disturbance predictions are also limited by small and nonrepresentative samples of test participants, and by restricted (airport-specific and relatively short duration) circumstances of exposure. Although expedient relationships may be the best available, their predictions are of only limited utility for policy analysis and regulatory purposes, because they account for very little variance in the association between environmental noise and sleep disturbance, have characteristically shallow slopes, have not been well validated in field settings, are highly context-dependent, and do not squarely address the roles and relative importance of nonacoustic factors in sleep disturbance. Such relationships offer the appearance more than the substance of precision and objectivity. Truly useful, population-level prediction and genuine understanding of noise-induced sleep disturbance will remain beyond reach for the foreseeable future, until the findings of field studies of broader scope and more sophisticated design become available.

  11. The state of the art of predicting noise-induced sleep disturbance in field settings

    Directory of Open Access Journals (Sweden)

    Sanford Fidell

    2010-01-01

    Full Text Available Several relationships between intruding noises (largely aircraft and sleep disturbance have been inferred from the findings of a handful of field studies. Comparisons of sleep disturbance rates predicted by the various relationships are complicated by inconsistent data collection methods and definitions of predictor variables and predicted quantities. None of the relationships is grounded in theory-based understanding, and some depend on questionable statistical assumptions and analysis procedures. The credibility, generalizability, and utility of sleep disturbance predictions are also limited by small and nonrepresentative samples of test participants, and by restricted (airport-specific and relatively short duration circumstances of exposure. Although expedient relationships may be the best available, their predictions are of only limited utility for policy analysis and regulatory purposes, because they account for very little variance in the association between environmental noise and sleep disturbance, have characteristically shallow slopes, have not been well validated in field settings, are highly context-dependent, and do not squarely address the roles and relative importance of nonacoustic factors in sleep disturbance. Such relationships offer the appearance more than the substance of precision and objectivity. Truly useful, population-level prediction and genuine understanding of noise-induced sleep disturbance will remain beyond reach for the foreseeable future, until the findings of field studies of broader scope and more sophisticated design become available.

  12. Reducing Risk of Noise-Induced Hearing Loss in Collegiate Music Ensembles Using Ambient Technology.

    Science.gov (United States)

    Powell, Jason; Chesky, Kris

    2017-09-01

    Student musicians are at risk for noise-induced hearing loss (NIHL) as they develop skills and perform during instructional activities. Studies using longitudinal dosimeter data show that pedagogical procedures and instructor behaviors are highly predictive of NIHL risk, thus implying the need for innovative approaches to increase instructor competency in managing instructional activities without interfering with artistic and academic freedom. Ambient information systems, an emerging trend in human-computer interaction that infuses psychological behavioral theories into technologies, can help construct informative risk-regulating systems. The purpose of this study was to determine the effects of introducing an ambient information system into the ensemble setting. The system used two ambient displays and a counterbalanced within-subjects treatment study design with six jazz ensemble instructors to determine if the system could induce a behavior change that alters trends in measures resulting from dosimeter data. This study assessed efficacy using time series analysis to determine changes in eight statistical measures of behavior over a 9-wk period. Analysis showed that the system was effective, as all instructors showed changes in a combination of measures. This study is in an important step in developing non-interfering technology to reduce NIHL among academic musicians.

  13. The worker's ear: a history of noise-induced hearing loss.

    Science.gov (United States)

    Thurston, Floyd E

    2013-03-01

    Hearing loss afflicts millions of people throughout the world, and many of those millions are workers who have been exposed to excessive noise. People have always been surrounded by a variety of sounds in their environments, but the invention of gunpowder and the Industrial Revolution introduced new sounds of greater intensity than ever before. It is only within the past 40 years that serious efforts to reduce excessive noise at work sites have been initiated. In the latter half of the 20th century, many governments imposed regulations to limit workers' exposure to loud sounds. Because of this recent action, some people may believe that the recognition of occupational noise-induced hearing loss (NIHL) is relatively new. However, a review of selected historical and medical manuscripts, books, and articles show that the association of hearing changes with loud noise exposure was recognized for centuries before systematic attempts were made to limit the exposure. Delays in implementing controls to limit noise exposure were due to cultural reasons, technical problems in controlling noise generation, and a lack of understanding of the mechanics of hearing loss. A historical perspective on this issue may remind health care providers that they need to continue to emphasize hearing conservation measures as occupational noise exposures change with the shift of industrial activities between countries. Copyright © 2012 Wiley Periodicals, Inc.

  14. Emergence of noise-induced oscillations in the central circadian pacemaker.

    Directory of Open Access Journals (Sweden)

    Caroline H Ko

    2010-10-01

    Full Text Available Bmal1 is an essential transcriptional activator within the mammalian circadian clock. We report here that the suprachiasmatic nucleus (SCN of Bmal1-null mutant mice, unexpectedly, generates stochastic oscillations with periods that overlap the circadian range. Dissociated SCN neurons expressed fluctuating levels of PER2 detected by bioluminescence imaging but could not generate circadian oscillations intrinsically. Inhibition of intercellular communication or cyclic-AMP signaling in SCN slices, which provide a positive feed-forward signal to drive the intracellular negative feedback loop, abolished the stochastic oscillations. Propagation of this feed-forward signal between SCN neurons then promotes quasi-circadian oscillations that arise as an emergent property of the SCN network. Experimental analysis and mathematical modeling argue that both intercellular coupling and molecular noise are required for the stochastic rhythms, providing a novel biological example of noise-induced oscillations. The emergence of stochastic circadian oscillations from the SCN network in the absence of cell-autonomous circadian oscillatory function highlights a previously unrecognized level of circadian organization.

  15. Noise-induced hearing loss in construction workers being assessed for hand-arm vibration syndrome.

    Science.gov (United States)

    House, Ronald A; Sauvé, John T; Jiang, Depeng

    2010-01-01

    Construction workers are at risk of noise-induced hearing loss (NIHL) but often have no periodic audiometric testing. The participants were construction workers assessed for Hand-Arm Vibration Syndrome (HAVS) at the Occupational Health Clinic, St. Michael's Hospital, Toronto, Ontario. Audiometry was offered and 169 of the 191 workers assessed for HAVS agreed to have the audiometric test. The objective was to examine the prevalence of hearing loss in these 169 workers and to determine the effect on hearing of duration of work in construction (as a proxy for noise exposure) and the severity of vibration white finger (VWF) which previous studies have suggested is a marker for increased individual susceptibility for NIHL. VWF was measured by the Stockholm vascular scale. All participants were men, median age of 57 (range: 28-75), median number of years worked in construction of 35 (range: 4-52). All of the Spearman rank correlations between years worked in construction and the hearing levels at each audiometric frequency were statistically significant (p hearing loss at or above the level at which a workers' compensation pension would be granted in Ontario and the prevalence of this auditory outcome had a statistically significant increase as years worked in construction increased. Multivariate linear regression indicated that VWF also had a statistically significant effect on hearing loss for all audiometric frequencies combined after controlling for years worked in construction. Improved prevention of hearing loss in construction workers is needed.

  16. Noise-induced hearing loss in a longitudinal study of Norwegian railway workers.

    Science.gov (United States)

    Lie, Arve; Skogstad, Marit; Johnsen, Torstein Seip; Engdahl, Bo; Tambs, Kristian

    2016-09-02

    The aim of this study was to analyse longitudinal data to assess the risk of noise-induced hearing loss (NIHL) in Norwegian railway workers. Longitudinal. A major Norwegian railway company. We examined data from the first and last audiograms for the period 1991-2014, from 9640 railway workers with varying occupational noise exposure and with an average observation period of 10 years. The course of hearing acuity in seven groups of railway workers (train drivers, conductors, bus drivers, traffic controllers, train maintenance workers, track maintenance workers and others) were compared with each other and with ISO standards (ISO 1999). The change in hearing threshold during the observation period was 2-3 dB in the 0.5-4 kHz range and 6-7 dB in the 3-6 kHz range adjusted for age and sex, for all occupational groups, which is slightly less than expected (8 dB) according to ISO 1999. The risk of NIHL in Norwegian railway workers during the period 1991-2014 has been negligible. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  17. Occupational noise-induced hearing loss in auto part factory workers in welding units in Thailand.

    Science.gov (United States)

    Sriopas, Apiradee; Chapman, Robert S; Sutammasa, Saravudh; Siriwong, Wattasit

    2017-01-24

    Most workers in auto part factories in Thailand are usually exposed to excessive noise in their workplace. This study aimed to assess the level of occupational noise-induced hearing loss and investigate risk factors causing hearing loss in auto part factory workers in the welding units in Thailand. This was a cross-sectional study. One hundred eighty subjects were recruited from 356 workers in the welding unit of three factories. Sixty eligible subjects in each factory were selected by systemic random sampling. The subjects were interviewed using a face-to-face questionnaire. Noise exposure levels and audiograms were measured by a noise dosimeter and an audiometer, respectively. The findings confirmed that noise exposure levels of 86-90 dB (A) and exceeding 90 dB (A) significantly increased the risk of hearing loss in either ear. A noise exposure level exceeding 90 dB (A) significantly increased the prevalence of hearing loss in both ears. Regarding, a 10-pack-year smoking history increased the prevalence of hearing loss in either ear or both ears. In addition, subjects with employment duration exceeding 10 years significantly developed hearing loss in either ear. The engineering control or personal control by wearing hearing protection device should be used to decrease noise exposure levels lower than 85 dB (A) for 8 h. Moreover, if the exposure level reaches 85 dB (A) for 8 h, the employer needs to implement a hearing conservation program in the workplace.

  18. Estimates of Workers with Noise-Induced Hearing Loss and Population at Risk

    Science.gov (United States)

    Miyakita, T.; Ueda, A.

    1997-08-01

    Towards the goal of protecting workers from damage due to noise exposure, a vast store of knowledge has been generated about its nature, etiology and time course. There still exists, however, a strong need to reclarify the locations, nature and magnitude of the problem of noise-induced hearing loss (NIHL). Based on the rate of positive results in a hearing screening test in the workplace, this paper presents an attempt to estimate the total number of workers with more than 40 dB hearing loss at 4 kHz caused by occupational noise exposure. The estimated values in major industry groups were as follows: about 780 000 in manufacturing; 410 000 in construction; 360 000 in agriculture; forestry and fishing; and around 2 million in total. Although it is rather difficult to estimate the number of workers exposed to noise above 85 dB(A), it may be reasonable to believe that at least several million workers exposed to noise should be covered by the 1992 guidelines for the prevention of noise hazards.

  19. High-frequency audiometry: A means for early diagnosis of noise-induced hearing loss

    Directory of Open Access Journals (Sweden)

    Amir H Mehrparvar

    2011-01-01

    Full Text Available Noise-induced hearing loss (NIHL, an irreversible disorder, is a common problem in industrial settings. Early diagnosis of NIHL can help prevent the progression of hearing loss, especially in speech frequencies. For early diagnosis of NIHL, audiometry is performed routinely in conventional frequencies. We designed this study to compare the effect of noise on high-frequency audiometry (HFA and conventional audiometry. In a historical cohort study, we compared hearing threshold and prevalence of hearing loss in conventional and high frequencies of audiometry among textile workers divided into two groups: With and without exposure to noise more than 85 dB. The highest hearing threshold was observed at 4000 Hz, 6000 Hz and 16000 Hz in conventional right ear audiometry, conventional left ear audiometry and HFA in each ear, respectively. The hearing threshold was significantly higher at 16000 Hz compared to 4000. Hearing loss was more common in HFA than conventional audiometry. HFA is more sensitive to detect NIHL than conventional audiometry. It can be useful for early diagnosis of hearing sensitivity to noise, and thus preventing hearing loss in lower frequencies especially speech frequencies.

  20. Occupational noise-induced tinnitus: does it affect workers' quality of life?

    Science.gov (United States)

    Muluk, Nuray Bayar; Oguztürk, Omer

    2008-02-01

    This prospective study aimed to investigate the quality of life of workers in a steel factory. The study group was composed of 16 male workers with tinnitus and 30 ears. Fifteen male workers without tinnitus and 30 ears were included into the control group. Workers were evaluated by questionnaire, pure-tone audiometry, and the SF-36 Health Survey. In the study group, tinnitus loudness levels (TLLs) were found. In the study group, the domains general mental health and role limitations owing to emotional problems were significantly lower than in the control group. Older age, industrial noise exposure over a long period, higher noise exposure during work, and hearing loss secondary to occupational noise caused workers to experience higher TLLs. Earheadings protected workers more than earplugs, and TLLs were lower. Important factors that affect workers' quality of life are maximum exposed noise levels, daily and total noise exposure time, and exposure to continuous noise. Occupational noise-induced tinnitus mainly causes emotional disability rather than physical disability. Emotionally impaired QOL results may be due to tinnitus-related psychological problems. Workers should have knowledge about the hazardous effects of noise. Periodic health checkups and regular seminars have great importance. Workers must be aware of other ototoxic factors, such as medications and noisy music. In the future, researchers should develop a screening method to detect those with a more hereditary affinity to hearing loss.

  1. Protective role of hydrogen sulfide against noise-induced cochlear damage: a chronic intracochlear infusion model.

    Directory of Open Access Journals (Sweden)

    Xu Li

    Full Text Available BACKGROUND: A reduction in cochlear blood flow plays an essential role in noise-induced hearing loss (NIHL. The timely regulation of cochlear perfusion determines the progression and prognosis of NIHL. Hydrogen sulfide (H(2S has attracted increasing interest as a vasodilator in cardiovascular systems. This study identified the role of H(2S in cochlear blood flow regulation and noise protection. METHODOLOGY/PRINCIPAL FINDINGS: The gene and protein expression of the H(2S synthetase cystathionine-γ-lyase (CSE in the rat cochlea was examined using immunofluorescence and real-time PCR. Cochlear CSE mRNA levels varied according to the duration of noise exposure. A chronic intracochlear infusion model was built and artificial perilymph (AP, NaHS or DL-propargylglycine (PPG were locally administered. Local sodium hydrosulfide (NaHS significantly increased cochlear perfusion post-noise exposure. Cochlear morphological damage and hearing loss were alleviated in the NaHS group as measured by conventional auditory brainstem response (ABR, cochlear scanning electron microscope (SEM and outer hair cell (OHC count. The highest percentage of OHC loss occurred in the PPG group. CONCLUSIONS/SIGNIFICANCE: Our results suggest that H(2S plays an important role in the regulation of cochlear blood flow and the protection against noise. Further studies may identify a new preventive and therapeutic perspective on NIHL and other blood supply-related inner ear diseases.

  2. Noise-induced hearing loss and associated factors among vector control workers in a Malaysian state.

    Science.gov (United States)

    Masilamani, Retneswari; Rasib, Abdul; Darus, Azlan; Ting, Anselm Su

    2014-11-01

    This study aims to determine the prevalence and associated factors of noise-induced hearing loss (NIHL) among vector control workers in the state of Negeri Sembilan, Malaysia. This was an analytical cross-sectional study conducted on 181 vector control workers who were working in district health offices in a state in Malaysia. Data were collected using a self-administered questionnaire and audiometry. Prevalence of NIHL was 26% among this group of workers. NIHL was significantly associated with the age-group of 40 years and older, length of service of 10 or more years, current occupational noise exposure, listening to loud music, history of firearms use, and history of mumps/measles infection. Following logistic regression, age of more than 40 years and noise exposure in current occupation were associated with NIHL with an odds ratio of 3.45 (95% confidence interval = 1.68-7.07) and 6.87 (95% confidence interval = 1.54-30.69), respectively, among this group of vector control workers. © 2012 APJPH.

  3. Patterns of patterns of synchronization: Noise induced attractor switching in rings of coupled nonlinear oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Emenheiser, Jeffrey [Complexity Sciences Center, University of California, Davis, California 95616 (United States); Department of Physics, University of California, Davis, California 95616 (United States); Chapman, Airlie; Mesbahi, Mehran [William E. Boeing Department of Aeronautics and Astronautics, University of Washington, Seattle, Washington 98195 (United States); Pósfai, Márton [Complexity Sciences Center, University of California, Davis, California 95616 (United States); Department of Computer Science, University of California, Davis, California 95616 (United States); Crutchfield, James P. [Complexity Sciences Center, University of California, Davis, California 95616 (United States); Department of Physics, University of California, Davis, California 95616 (United States); Department of Computer Science, University of California, Davis, California 95616 (United States); Santa Fe Institute, Santa Fe, New Mexico 87501 (United States); D' Souza, Raissa M. [Complexity Sciences Center, University of California, Davis, California 95616 (United States); Department of Computer Science, University of California, Davis, California 95616 (United States); Santa Fe Institute, Santa Fe, New Mexico 87501 (United States); Department of Mechanical and Aerospace Engineering, University of California, Davis, California 95616 (United States)

    2016-09-15

    Following the long-lived qualitative-dynamics tradition of explaining behavior in complex systems via the architecture of their attractors and basins, we investigate the patterns of switching between distinct trajectories in a network of synchronized oscillators. Our system, consisting of nonlinear amplitude-phase oscillators arranged in a ring topology with reactive nearest-neighbor coupling, is simple and connects directly to experimental realizations. We seek to understand how the multiple stable synchronized states connect to each other in state space by applying Gaussian white noise to each of the oscillators' phases. To do this, we first analytically identify a set of locally stable limit cycles at any given coupling strength. For each of these attracting states, we analyze the effect of weak noise via the covariance matrix of deviations around those attractors. We then explore the noise-induced attractor switching behavior via numerical investigations. For a ring of three oscillators, we find that an attractor-switching event is always accompanied by the crossing of two adjacent oscillators' phases. For larger numbers of oscillators, we find that the distribution of times required to stochastically leave a given state falls off exponentially, and we build an attractor switching network out of the destination states as a coarse-grained description of the high-dimensional attractor-basin architecture.

  4. Cochlear NMDA Receptors as a Therapeutic Target of Noise-Induced Tinnitus

    Directory of Open Access Journals (Sweden)

    Dan Bing

    2015-03-01

    Full Text Available Background: Accumulating evidence suggests that tinnitus may occur despite normal auditory sensitivity, probably linked to partial degeneration of the cochlear nerve and damage of the inner hair cell (IHC synapse. Damage to the IHC synapses and deafferentation may occur even after moderate noise exposure. For both salicylate- and noise-induced tinnitus, aberrant N-methyl-d-aspartate (NMDA receptor activation and related auditory nerve excitation have been suggested as origin of cochlear tinnitus. Accordingly, NMDA receptor inhibition has been proposed as a pharmacologic approach for treatment of synaptopathic tinnitus. Methods: Round-window application of the NMDA receptor antagonist AM-101 (Esketamine hydrochloride gel; Auris Medical AG, Basel, Switzerland was tested in an animal model of tinnitus induced by acute traumatic noise. The study included the quantification of IHC ribbon synapses as a correlate for deafferentation as well as the measurement of the auditory brainstem response (ABR to close-threshold sensation level stimuli as an indication of sound-induced auditory nerve activity. Results: We have shown that AM-101 reduced the trauma-induced loss of IHC ribbons and counteracted the decline of ABR wave I amplitude generated in the cochlea/auditory nerve. Conclusion: Local round-window application of AM-101 may be a promising therapeutic intervention for the treatment of synaptopathic tinnitus.

  5. Resistance to antitumor chemotherapy due to bounded-noise-induced transitions

    Science.gov (United States)

    D'Onofrio, Alberto; Gandolfi, Alberto

    2010-12-01

    Tumor angiogenesis is a landmark of solid tumor development, but it is also directly relevant to chemotherapy. Indeed, the density and quality of neovessels may influence the effectiveness of therapies based on blood-born agents. In this paper, first we define a deterministic model of antiproliferative chemotherapy in which the drug efficacy is a unimodal function of vessel density, and then we show that under constant continuous infusion therapy the tumor-vessel system may be multistable. However, the actual drug concentration profiles are affected by bounded even if possibly large fluctuations. Through numerical simulations, we show that the tumor volume may undergo transitions to the higher equilibrium value induced by the bounded noise. In case of periodically delivered boli-based chemotherapy, we model the fluctuations due to time variability of both the drug clearance rate and the distribution volume, as well as those due to irregularities in drug delivery. We observed noise-induced transitions also in case of periodic delivering. By applying a time dense scheduling with constant average delivered drug (metronomic scheduling), we observed an easier suppression of the transitions. Finally, we propose to interpret the above phenomena as an unexpected non-genetic kind of resistance to chemotherapy.

  6. Noise-Induced Loss of Hair Cells and Cochlear Synaptopathy Are Mediated by the Activation of AMPK.

    Science.gov (United States)

    Hill, Kayla; Yuan, Hu; Wang, Xianren; Sha, Su-Hua

    2016-07-13

    Noise-induced hearing loss (NIHL) is a major unresolved public health problem. Here, we investigate pathomechanisms of sensory hair cell death and suggest a novel target for protective intervention. Cellular survival depends upon maintenance of energy homeostasis, largely by AMP-activated protein kinase (AMPK). In response to a noise exposure in CBA/J mice, the levels of phosphorylated AMPKα increased in hair cells in a noise intensity-dependent manner. Inhibition of AMPK via siRNA or the pharmacological inhibitor compound C attenuated noise-induced loss of outer hair cells (OHCs) and synaptic ribbons, and preserved auditory function. Additionally, noise exposure increased the activity of the upstream AMPK kinase liver kinase B1 (LKB1) in cochlear tissues. The inhibition of LKB1 by siRNA attenuated the noise-increased phosphorylation of AMPKα in OHCs, reduced the loss of inner hair cell synaptic ribbons and OHCs, and protected against NIHL. These results indicate that noise exposure induces hair cell death and synaptopathy by activating AMPK via LKB1-mediated pathways. Targeting these pathways may provide a novel route to prevent NIHL. Our results demonstrate for the first time that the activation of AMP-activated protein kinase (AMPK) α in sensory hair cells is noise intensity dependent and contributes to noise-induced hearing loss by mediating the loss of inner hair cell synaptic ribbons and outer hair cells. Noise induces the phosphorylation of AMPKα1 by liver kinase B1 (LKB1), triggered by changes in intracellular ATP levels. The inhibition of AMPK activation by silencing AMPK or LKB1, or with the pharmacological inhibitor compound C, reduced outer hair cell and synaptic ribbon loss as well as noise-induced hearing loss. This study provides new insights into mechanisms of noise-induced hearing loss and suggests novel interventions for the prevention of the loss of sensory hair cells and cochlear synaptopathy. Copyright © 2016 the authors 0270-6474/16/367497-14$15.00/0.

  7. Pathogenesis mechanism by noise induced clinical pictures-lessons from the Spandau health-survey; Pathogenesemechanismen bei laerminduzierten Krankheitsbildern - Schlussfolgerungen aus dem Spandauer Gesundheits-Survey

    Energy Technology Data Exchange (ETDEWEB)

    Maschke, C. [Forschungs- und Beratungsbuero Maschke (FBB-Maschke), Berlin (Germany); Hecht, K. [Interdisziplinaerer Forschungsverbund Laerm und Gesundheit, Berlin (Germany)

    2005-07-01

    Traffic noise (road noise, flight noise, train noise) is the predominant noise source in the living environment, followed by neighbourhood noise. Through the central nervous processes noise can lead, via disturbed sleep as well as via subjective experience, to an inadequate neuro-endocrine reaction with the possibility of finally leading to diseases which are mediated or triggered by stress. Noise induced health disturbances by traffic noise is a large and contrarily discussed problem. In the context of the Spandau health survey, both the noise load (equivalent sound level) and the noise experience (disturbances) were collected and the relationship with medically treated illnesses evaluated. The results suggest that two different ''effect mechanisms'' exist regarding the health effect of traffic noise. Besides the noise disturbed sleep, an insufficient coping with the noise exposures can lead to increased disease risks. The study shows convincing relations between impairments of the heart circulation system (e.g. with hypertension) and the nightly equivalent sound level (22.00-6:00 hours) at the place of residents of the test persons. It has to be assumed that this is the long-term result of sleep which is not restful. On the other hand, psychic disturbances were less connected to the sound level and had more correlation with the noise experience. With psychic disturbances the individual overtaxing of the information-processing processes plays an important role and is classified as an emotional stress situation. (orig.)

  8. Noise-induced phase space transport in two-dimensional Hamiltonian systems

    International Nuclear Information System (INIS)

    Pogorelov, I.V.; Kandrup, H.E.

    1999-01-01

    First passage time experiments were used to explore the effects of low amplitude noise as a source of accelerated phase space diffusion in two-dimensional Hamiltonian systems, and these effects were then compared with the effects of periodic driving. The objective was to quantify and understand the manner in which open-quotes stickyclose quotes chaotic orbits that, in the absence of perturbations, are confined near regular islands for very long times, can become open-quotes unstuckclose quotes much more quickly when subjected to even very weak perturbations. For both noise and periodic driving, the typical escape time scales logarithmically with the amplitude of the perturbation. For white noise, the details seem unimportant: Additive and multiplicative noise typically have very similar effects, and the presence or absence of a friction related to the noise by a fluctuation-dissipation theorem is also largely irrelevant. Allowing for colored noise can significantly decrease the efficacy of the perturbation, but only when the autocorrelation time, which vanishes for white noise, becomes so large that there is little power at frequencies comparable to the natural frequencies of the unperturbed orbit. Similarly, periodic driving is relatively inefficient when the driving frequency is not comparable to these natural frequencies. This suggests that noise-induced extrinsic diffusion, like modulational diffusion associated with periodic driving, is a resonance phenomenon. The logarithmic dependence of the escape time on amplitude reflects the fact that the time required for perturbed and unperturbed orbits to diverge a given distance scales logarithmically in the amplitude of the perturbation. copyright 1999 The American Physical Society

  9. Lightning-Discharge Initiation as a Noise-Induced Kinetic Transition

    Science.gov (United States)

    Iudin, D. I.

    2017-10-01

    The electric fields observed in thunderclouds have the peak values one order of magnitude smaller than the electric strength of air. This fact renders the issue of the lightning-discharge initiation one of the most intriguing problems of thunderstorm electricity. In this work, the lightning initiation in a thundercloud is considered as a noise-induced kinetic transition. The stochastic electric field of the charged hydrometeors is the noise source. The considered kinetic transition has some features which distinguish it from other lightning-initiation mechanisms. First, the dynamic realization of this transition, which is due to interaction of the electron and ion components, is extended for a time significantly exceeding the spark-discharge development time. In this case, the fast attachment of electrons generated by supercritical bursts of the electric field of hydrometeors is balanced during long-term time intervals by the electron-release processes when the negative ions are destroyed. Second, an important role in the transition kinetics is played by the stochastic drift of electrons and ions caused by the small-scale fluctuations of the field of charged hydrometeors. From the formal mathematical viewpoint, this stochastic drift is indistinguishable from the scalar-impurity advection in a turbulent flow. In this work, it is shown that the efficiency of "advective mixing" is several orders of magnitude greater than that of the ordinary diffusion. Third, the considered transition leads to a sharp increase in the conductivity in the exponentially rare compact regions of space against the background of the vanishingly small variations in the average conductivity of the medium. In turn, the spots with increased conductivity are polarized in the mean field followed by the streamer initiation and discharge contraction.

  10. Predictive factors of occupational noise-induced hearing loss in Spanish workers: A prospective study.

    Science.gov (United States)

    Pelegrin, Armando Carballo; Canuet, Leonides; Rodríguez, Ángeles Arias; Morales, Maria Pilar Arévalo

    2015-01-01

    The purpose of our study was to identify the main factors associated with objective noise-induced hearing loss (NIHL), as indicated by abnormal audiometric testing, in Spanish workers exposed to occupational noise in the construction industry. We carried out a prospective study in Tenerife, Spain, using 150 employees exposed to occupational noise and 150 age-matched controls who were not working in noisy environments. The variables analyzed included sociodemographic data, noise-related factors, types of hearing protection, self-report hearing loss, and auditory-related symptoms (e.g., tinnitus, vertigo). Workers with pathological audiograms had significantly longer noise-exposure duration (16.2 ± 11.4 years) relative to those with normal audiograms (10.2 ± 7.0 years; t = 3.99, P hearing protection measures had audiometric abnormalities (94.1%). Additionally, workers using at least one of the protection devices (earplugs or earmuffs) had significantly more audiometric abnormalities than those using both protection measures simultaneously (Chi square = 16.07; P hearing protection measures [odds ratio (OR) = 12.30, confidence interval (CI) = 4.36-13.81, P hearing protection measures, in particular earplugs and earmuffs, associates with a lower rate of audiometric abnormalities in subjects with high occupational noise exposure. The use of hearing protection measures at work and noise-exposure duration are best predictive factors of NIHL. Auditory-related symptoms and self-report hearing loss do not represent good indicators of objective NIHL. Routine monitoring of noise levels and hearing status are of great importance as part of effective hearing conservation programs.

  11. Noise-induced hearing loss and combined noise and vibration exposure.

    Science.gov (United States)

    Turcot, A; Girard, S A; Courteau, M; Baril, J; Larocque, R

    2015-04-01

    While there is a wide body of literature addressing noise-induced hearing loss (NIHL) and hand-arm vibration syndrome (HAVS) independently, relatively few studies have considered the combined effects of noise and vibration. These studies have suggested an increased risk of NIHL in workers with vibration white finger (VWF), though the relationship remains poorly understood. To determine whether hearing impairment is worse in noise-exposed workers with VWF than in workers with similar noise exposures but without VWF. The Quebec National Institute of Public Health audiometric database was used in conjunction with work-related accident and occupational diseases data from the Quebec workers' compensation board to analyse differences in audiometry results between vibration-exposed workers in the mining and forestry industries and the overall source population, and between mining and forestry workers with documented VWF and those without VWF. The International Organization for Standardization (ISO) 7029 standards were used to calculate hearing loss not attributable to age. 15751 vibration-exposed workers were identified in an overall source population of 59339. Workers with VWF (n = 96) had significantly worse hearing at every frequency studied (500, 1000, 2000 4000 Hz) compared with other mining and forestry workers without VWF. This study confirms previous findings of greater hearing loss at higher frequencies in workers with VWF, but also found a significant difference in hearing loss at low frequencies. It therefore supports the association between combined noise and hand-arm vibration (HAV) exposure and NIHL. © The Author 2015. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Effect of Ascorbic Acid on Noise Induced Hearing Loss in Rats

    Directory of Open Access Journals (Sweden)

    Ziba Loukzadeh

    2015-07-01

    Full Text Available Introduction: After presbycusis, noise-induced hearing loss is the second most common cause of acquired hearing loss. Numerous studies have shown that high-intensity noise exposure increases free radical species; therefore, use of antioxidants to detoxify the free radicals can prevent cellular damage in the cochlea. We studied the potential hearing protective effect of different doses of ascorbic acid administered prior to noise exposure in rats.   Materials and Methods: Twenty-four male albino Wistar rats were randomly allocated into four groups: groups A, B, and C received 1250, 250, and 50 mg/kg/day of ascorbic acid, respectively, and group D acted as the control group. After 14 days of ascorbic acid administration, the rats were exposed to noise (105 dB sound pressure level for 2 h. Distortion product otoacoustic emissions (DPOAE were recorded prior to starting the ascorbic acid as baseline and 1 h after the noise exposure.   Results: The amplitude decrease was 14.99 dB for group A, 16.11 dB for group B, 28.82 dB for group C, and 29.91 dB for the control group. Moderate and high doses of ascorbic acid significantly reduced the transient threshold shift in the rats.   Conclusion:  The results of present study support the concept of cochlea protection by antioxidant agents. This dose-dependent protective effect was shown through the use of ascorbic acid treatment prior to noise exposure.

  13. Effect of occupational noise-induced sleep disturbance on worker's health

    Directory of Open Access Journals (Sweden)

    Milad Abbasi

    2017-01-01

    Full Text Available Aims: In addition to the noise, sleep disturbance (SD as an outcome of the exposure to the wind turbine noises (WTNs can adversely affect general health. This study aimed to investigate the effect of SD induced from WTNs on general health indicators. Materials and Methods: A total number of fifty tree workers from Manjil wind farm voluntarily participated in this study. Based on the job similarity and vicinity to the sound sources, workers were classified into three occupational groups including repairman, security, and official staff. Individual's health and sleep status were gathered using the 28-item General Health Questionnaire and Epworth Sleepiness Scales, respectively. Noise was measured based on ISO 9612. ANOVA, Chi-square, and linear and multiple regression tests were used for data analysis in the SPSS 20 software environment. Results: The mean values of 8-h equivalent continuous A-weighted sound pressure level (LAeq, 8 h among whole workers was 71 ± 10 dB (A. The averages of somatic symptom, anxiety insomnia, social dysfunction, depression, and general health among the participants were 5 ± 2.44, 7 ± 2.35, 11 ± 2.65, 2 ± 1.54, 22 ± 6.53, and 7.3 ± 3.1, respectively. According to the results, SD and noise exposure had an adverse health effect on physical symptoms, depression, and overall general health of participants. Moreover, SD and work experience were effective factors on anxiety-insomnia. SD had greatest effect on general health when all variables are controlled, so that general health will increase by 2.42 units for each unit increase of SD. Conclusion: We found that in addition to the sound effect, noise-induced SD also affects worker's health and strengthen sound effects on human well-being.

  14. Zebrafish hair cell mechanics and physiology through the lens of noise-induced hair cell death

    Science.gov (United States)

    Coffin, Allison B.; Xu, Jie; Uribe, Phillip M.

    2018-05-01

    Hair cells are exquisitely sensitive to auditory stimuli, but also to damage from a variety of sources including noise trauma and ototoxic drugs. Mammals cannot regenerate cochlear hair cells, while non-mammalian vertebrates exhibit robust regenerative capacity. Our research group uses the lateral line system of larval zebrafish to explore the mechanisms underlying hair cell damage, identify protective therapies, and determine molecular drivers of innate regeneration. The lateral line system contains externally located sensory organs called neuromasts, each composed of ˜8-20 hair cells. Lateral line hair cells are homologous to vertebrate inner ear hair cells and share similar susceptibility to ototoxic damage. In the last decade, the lateral line has emerged as a powerful model system for understanding hair cell death mechanisms and for identifying novel protective compounds. Here we demonstrate that the lateral line is a tractable model for noise-induced hair cell death. We have developed a novel noise damage system capable of inducing over 50% loss of lateral line hair cells, with hair cell death occurring in a dose- and time-dependent manner. Cell death is greatest 72 hours post-exposure. However, early signs of hair cell damage, including changes in membrane integrity and reduced mechanotransduction, are apparent within hours of noise exposure. These features, early signs of damage followed by delayed hair cell death, are consistent with mammalian data, suggesting that noise acts similarly on zebrafish and mammalian hair cells. In our future work we will use our new model system to investigate noise damage events in real time, and to develop protective therapies for future translational research.

  15. Coding deficits in noise-induced hidden hearing loss may stem from incomplete repair of ribbon synapses in the cochlea

    Directory of Open Access Journals (Sweden)

    Lijuan eShi

    2016-05-01

    Full Text Available Recent evidence has shown that noise-induced damage to the synapse between inner hair cells (IHCs and type I afferent auditory nerve fibers (ANFs may occur in the absence of permanent threshold shift (PTS, and that synapses connecting IHCs with low spontaneous rate (SR ANFs are disproportionately affected. Due to the functional importance of low-SR ANF units for temporal processing and signal coding in noisy backgrounds, deficits in cochlear coding associated with noise-induced damage may result in significant difficulties with temporal processing and hearing in noise (i.e., hidden hearing loss. However, significant noise-induced coding deficits have not been reported at the single unit level following the loss of low-SR units. We have found evidence to suggest that some aspects of neural coding are not significantly changed with the initial loss of low-SR ANFs, and that further coding deficits arise in association with the subsequent reestablishment of the synapses. This suggests that synaptopathy in hidden hearing loss may be the result of insufficient repair of disrupted synapses, and not simply due to the loss of low-SR units. These coding deficits include decreases in driven spike rate for intensity coding as well as several aspects of temporal coding: spike latency, peak-to-sustained spike ratio and the recovery of spike rate as a function of click-interval.

  16. Noise-induced hearing loss - An examination of the methods of assessment in a cross-sectional study of 87 industrial workers.

    Science.gov (United States)

    Das, S; Mulheran, M; Brewster, M; Banerjee, A R

    2018-04-01

    The surveillance of noise-induced hearing loss (NIHL) according to the Health and Safety Executive (HSE) differs from the medico-legal criteria used to assess NIHL. Our study compares the two systems and proposes a novel method of simplifying the medico-legal criteria and applying it to ascertain noise-induced hearing loss. The anonymised audiograms of a group of 87 industrial workers from a single site were analysed with both methods. The comparison showed approximately one-third of the workers assessed in this study had their noise-induced hearing loss underestimated by the HSE criteria. The majority of these individuals were over 40 years of age. The HSE criteria for noise-induced hearing loss need review and re-alignment with the medico-legal criteria to address the discrepancy between the two systems. © 2017 John Wiley & Sons Ltd.

  17. Deterioration of noise-induced hearing loss among bottling factory workers.

    Science.gov (United States)

    Ologe, F E; Olajide, T G; Nwawolo, C C; Oyejola, B A

    2008-08-01

    monitoring hearing deterioration. It is necessary to enforce existing occupational health laws in our industries in order to prevent noise-induced hearing loss, since it is eminently preventable.

  18. Subchronic JP-8 jet fuel exposure enhances vulnerability to noise-induced hearing loss in rats.

    Science.gov (United States)

    Fechter, L D; Fisher, J W; Chapman, G D; Mokashi, V P; Ortiz, P A; Reboulet, J E; Stubbs, J E; Lear, A M; McInturf, S M; Prues, S L; Gearhart, C A; Fulton, S; Mattie, D R

    2012-01-01

    Both laboratory and epidemiological studies published over the past two decades have identified the risk of excess hearing loss when specific chemical contaminants are present along with noise. The objective of this study was to evaluate the potency of JP-8 jet fuel to enhance noise-induced hearing loss (NIHL) using inhalation exposure to fuel and simultaneous exposure to either continuous or intermittent noise exposure over a 4-wk exposure period using both male and female Fischer 344 rats. In the initial study, male (n = 5) and female (n = 5) rats received inhalation exposure to JP-8 fuel for 6 h/d, 5 d/wk for 4 wk at concentrations of 200, 750, or 1500 mg/m³. Parallel groups of rats also received nondamaging noise (constant octave band noise at 85 dB(lin)) in combination with the fuel, noise alone (75, 85, or 95 dB), or no exposure to fuel or noise. Significant concentration-related impairment of auditory function measured by distortion product otoacoustic emissions (DPOAE) and compound action potential (CAP) threshold was seen in rats exposed to combined JP-8 plus noise exposure when JP-8 levels of 1500 mg/m³ were presented with trends toward impairment seen with 750 mg/m³ JP-8 + noise. JP-8 alone exerted no significant effect on auditory function. In addition, noise was able to disrupt the DPOAE and increase auditory thresholds only when noise exposure was at 95 dB. In a subsequent study, male (n = 5 per group) and female (n = 5 per group) rats received 1000 mg/m³ JP-8 for 6 h/d, 5 d/wk for 4 wk with and without exposure to 102 dB octave band noise that was present for 15 min out of each hour (total noise duration 90 min). Comparisons were made to rats receiving only noise, and thosereceiving no experimental treatment. Significant impairment of auditory thresholds especially for high-frequency tones was identified in the male rats receiving combined treatment. This study provides a basis for estimating excessive hearing loss under

  19. [Association between eye absent homolog 4 gene polymorphisms and occupational noise-induced hearing loss].

    Science.gov (United States)

    Yang, Q Y; Xu, X R; Jiao, J; Zheng, Y X; He, L H; Yu, S F; Gu, G Z; Chen, G S; Zhou, W H; Wu, H; Li, Y H; Zhang, H L; Zhang, Z R

    2017-01-06

    Objective: To identify the association between genetic polymorphisms in the eye absent homolog 4 (EYA4) gene and noise-induced hearing loss (NIHL). Method: A nested case control study was conducted based on a cohort of noise-exposed subjects. In total, 292 cases were selected from a steel factory from 6 297 subjects during Jan 1, 2006 to Dec 12, 2015,who had an average hearing threshold of more than 40 dB(A); 584 matched control subjects for each case were designated on the basis of matched criteria including same gender, age (±5 years) and duration of exposure to noise (±2 years). What's more, the control group had an average hearing threshold of less than 35 dB(A) in high frequency and less than 25 dB(A) in speech frequency. Four single nucleotide polymorphisms (SNPs) of the EYA4 gene were genotyped using a SNPscan TM multiplex SNP genotyping kit. Hardy-Weinberg equilibrium tests were performed using a χ 2 test for goodness-of-fit for each SNP among the control group, and the effects of genotypes of the EYA4 gene on NIHL were analyzed by logistic regression. The haplotypes were established and their frequencies in the two groups were assessed using Haploview 4.2 and Phase 2.1 software, and interactive effects between haplotypes and cumulative noise exposure were analyzed. Results: The average age of the subjects was (40.1±8.4) years and the average number of noise-exposed working years was 20.3 (8.4, 27.3) years. The range of noise exposure levels and the cumulative noise exposure were 80.2- 98.8 dB (A) and 86.6- 111.2 dB(A) · year, respectively. After adjustment for covariates including height, blood pressure, drinking status and smoking status, in the noise intensity>85 dB (A) group, subjects carrying the rs3813346 TT genotype had a higher NIHL risk than those carrying the GG genotype, and the adjusted OR (95% CI ) value was 2.12 (1.21- 3.69). In the cumulative noise exposure>98 dB (A) · year group, compared with haplotype TGC, haplotype CGT showed a

  20. Occupationally-acquired noise-induced hearing loss: a senseless workplace hazard.

    Science.gov (United States)

    Kurmis, Andrew P; Apps, Stacey A

    2007-01-01

    Occupational noise-induced hearing loss (ONIHL) describes an acquired hearing deficiency directly attributable to excessive workplace noise exposure. Data suggest that excessive noise attributes to approximately 37% of all adult causes of hearing loss and remains a significant contributor to employment-related morbidity internationally. Typically insidiously-acquired, often without frank progressive symptomatology, regional medical agencies continue to struggle with this potentially debilitating condition. The aim of the study was to provide a synopsis of the current understanding of ONIHL, its impact on individual workers and the wider international community, and to identify barriers to more uniform adoption of personal hearing protection. A review of the contemporary literature was performed using defined keyword searches and OVID, PubMed, and Google Scholar as primary electronic search engines. A number of published works were identified, describing aspects of the relationship between workplace-related noise exposure and subsequent development of employee hearing impairment, which demonstrate an overwhelming gender imbalance, with up to 97% of affected individuals being male. Industry-specific associations (e.g., mining, manufacturing and heavy construction) were well documented, as were links to toxin-specific exposures, in the recognized development of hearing loss. However, evidence of integration of appraisal of the topically-current area of genetic susceptibility was often lacking. Much discordance still exists among international agencies in the prescriptive regulation and enforcement of "safe" exposure limits. Despite a high level of public awareness regarding the importance of hearing preservation and increasingly stringent international occupational health, safety and welfare requirements mandating provision of safer work environments, ONIHL continues to be a significant occupational hazard. ONIHL is permanent and may cause significant disability, for

  1. Bioconversion of Scutellaria baicalensis extract can increase recovery of auditory function in a mouse model of noise-induced hearing loss.

    Science.gov (United States)

    Rodriguez, Isabel; Hong, Bin Na; Nam, Youn Hee; Kim, Eun Young; Park, Geun Ha; Ji, Min Gun; Kang, Tong Ho

    2017-09-01

    In noise-induced hearing loss (NIHL), noise exposure damages cochlear sensory hair cells, which lack the capacity to regenerate. Following noise insult, intense metabolic activity occurs, resulting in a cochlear free radical imbalance. Oxidative stress and antioxidant enzyme alterations, including lipoxygenase upregulation, have been linked to chronic inflammation, which contributes to hearing impairment. We previously proposed Scutellaria baicalensis (SB) extract as an alternative therapeutic for preventing NIHL and attributed its pharmacological effects to baicalein. Although baicalein was most effective, its concentration in SB extract is much lower compared to baicalin. In this study, we performed enzymatic bioconversion using an Sumizyme (SM) enzyme to increase baicalein concentration in SB extract and consequently improve its therapeutic efficacy. HPLC analysis revealed that baicalein concentration in SB extract after bioconversion (BSB) was significantly increased. Moreover, BSB-treated mice exhibited significantly improved auditory function compared with control mice and tended to have improved auditory function compared with SB-treated mice. We also demonstrated that BSB effectively stimulates hair cell regeneration compared to SB that did not achieve the same effect in a zebrafish model. Finally, when compared the abilities of SB and BSB to inhibit lipoxygenase (LOX), BSB showed a greater efficacy. Cumulatively, our data suggest that BSB exhibits improved pharmacological properties for treating NIHL compared with SB. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  2. Effects of small-world connectivity on noise-induced temporal and spatial order in neural media

    International Nuclear Information System (INIS)

    Perc, Matjaz

    2007-01-01

    We present an overview of possible effects of small-world connectivity on noise-induced temporal and spatial order in a two-dimensional network of excitable neural media with FitzHugh-Nagumo local dynamics. Small-world networks are characterized by a given fraction of so-called long-range couplings or shortcut links that connect distant units of the system, while all other units are coupled in a diffusive-like manner. Interestingly, already a small fraction of these long-range couplings can have wide-ranging effects on the temporal as well as spatial noise-induced dynamics of the system. Here we present two main effects. First, we show that the temporal order, characterized by the autocorrelation of a firing-rate function, can be greatly enhanced by the introduction of small-world connectivity, whereby the effect increases with the increasing fraction of introduced shortcut links. Second, we show that the introduction of long-range couplings induces disorder of otherwise ordered, spiral-wave-like, noise-induced patterns that can be observed by exclusive diffusive connectivity of spatial units. Thereby, already a small fraction of shortcut links is sufficient to destroy coherent pattern formation in the media. Although the two results seem contradictive, we provide an explanation considering the inherent scale-free nature of small-world networks, which on one hand, facilitates signal transduction and thus temporal order in the system, whilst on the other hand, disrupts the internal spatial scale of the media thereby hindering the existence of coherent wave-like patterns. Additionally, the importance of spatially versus temporally ordered neural network functioning is discussed

  3. Predicting hearing thresholds in occupational noise-induced hearing loss by auditory steady state responses.

    Science.gov (United States)

    Attias, Joseph; Karawani, Hanin; Shemesh, Rafi; Nageris, Ben

    2014-01-01

    Currently available behavioral tools for the assessment of noise-induced hearing loss (NIHL) depend on the reliable cooperation of the subject. Furthermore, in workers' compensation cases, there is considerable financial gain to be had from exaggerating symptoms, such that accurate assessment of true hearing threshold levels is essential. An alternative objective physiologic tool for assessing NIHL is the auditory steady state response (ASSR) test, which combines frequency specificity with a high level of auditory stimulation, making it applicable for the evaluation of subjects with a moderate to severe deficit. The primary aim of the study was to assess the value of the multifrequency ASSR test in predicting the behavioral warble-tone audiogram in a large sample of young subjects with NIHL of varying severity or with normal hearing. The secondary goal was to assess suprathreshold ASSR growth functions in these two groups. The study group included 157 subjects regularly exposed to high levels of occupational noise, who attended a university-associated audiological clinic for evaluation of NIHL from 2009 through 2011. All underwent a behavioral audiogram, and on the basis of the findings, were divided into those with NIHL (108 subjects, 216 ears) or normal hearing (49 subjects, 98 ears). The accuracy of the ASSR threshold estimations for frequencies of 500, 1000, 2000, and 4000 Hz was compared between groups, and the specificity and sensitivity of the ASSR test in differentiating ears with or without NIHL was calculated using receiver operating characteristic analysis. Linear regression analysis was used to formulate an equation to predict the behavioral warble-tone audiogram at each test frequency using ASSR thresholds. Multifrequency ASSR amplitude growth as a function of stimulus intensity was compared between the NIHL and normal-hearing groups for 1000 Hz and 4000 Hz carrier frequencies. In the subjects with NIHL, ASSR thresholds to various frequencies were

  4. [Association between variations in protocadherin 15 gene and occupational noise-induced hearing loss].

    Science.gov (United States)

    Xu, X R; Yang, Q Y; Jiao, J; Zheng, Y X; He, L H; Yu, S F; Gu, G Z; Chen, G S; Zhou, W H; Wu, H; Li, Y H; Zhang, H L; Zhang, Z R

    2017-01-06

    Objective: The aim of this study was to investigate whether genetic variability in the protocadherin 15 (PCDH15) gene may correspond with increased susceptibility to noise-induced hearing loss (NIHL) in a Chinese population. Methods: A nested case-control study was performed that followed a cohort of 7 445 noise-exposed workers in a steel factory of Henan province in China from January 1, 2006 to December 31, 2015. In this study, 394 cases who had an average hearing threshold of more than 40 dB (A) in high frequency were defined as the case group, and 721 controls who had an average hearing threshold of less than 35 dB (A) in high frequency and less than 25 dB (A) in speech frequency were defined as the control group. A questionnaire was completed by participants and a physical test was also conducted. SNP genotyping was performed using the SNPscan TM Kit. Multivariate unconditional logistic regression additive models were used to analyze the genotypes in different groups, and the association with NIHL. Unconditional logistic regression models were used to assess the associations between the genotypes and NIHL. Results: The average age of study participants was (40.5±8.3) years and the median number of noise-exposed working years M ( P 25 , P 75 ) was 21.1 (9.1, 27.3). The range of noise exposed levels and the levels of cumulative noise exposure (CNE) were 80.1- 98.8 dB(A) and 86.6- 111.2 dB(A), respectively. Only the distribution of the genotypes (TT/CC/CT) of rs11004085 in the PCDH15 gene showed a significant difference between the case and control groups ( P= 0.049). In the case group, the distribution was 370 (93.9%), 24 (6.1%) and 0; in the control group, the distribution was 694 (96.3%), 23 (3.2%) and 1 (0.1% ). After smoking, drinking, hypertension, height and CNE adjustment, compared with the TT genotype individuals with the CC/CT genotype had a 1.90-fold increased risk of NIHL (95% CI: 1.06- 3.40). After stratified these data by the noise exposure level

  5. Atmospheric Propagation Modeling Indicates Homing Pigeons use Loft-Specific Infrasonic 'Map' Cues

    Science.gov (United States)

    Hagstrum, J. T.; Baker, L. M.; Spritzer, J. M.; McKenna, M. H.

    2011-12-01

    Pigeons (Columba livia) released at distant sites commonly depart in directions significantly off the actual homeward bearing. Such site-dependent deviations, or biases, for birds from a given loft are generally stable over time, but can also change from hour to hour, day to day, and year to year. At some release sites, birds consistently vanish in random directions and have longer flight times and lower return rates. Release sites characterized by frequent disorientation are not uncommon for pigeon lofts in both Europe and the USA. One such site is the Jersey Hill fire tower in upstate New York located ~120 km W of the Cornell loft in Ithaca. Cornell birds released at Jersey Hill between 1968 and 1987 almost always vanished randomly, although birds from other lofts had little difficulty orienting there. The results for one day, however, stand out: on August 13, 1969, Cornell birds released at Jersey Hill vanished consistently to the NE (r = 0.921; n=7) and returned home after normal flight times. Cornell pigeons released the next day again showed 'normal' behavior for the site and departed randomly. If, in fact, the birds are using acoustic cues to navigate, the long-term acoustic 'dead' zone we propose for Jersey Hill, due to prevailing atmospheric conditions, indicates that the cues are coming from a single, relatively restricted area, most likely surrounding the home loft. We have modeled the transmission of infrasonic waves, presumably coupled to the atmosphere from ocean-generated microseisms (0.14 Hz), between the Cornell loft and a number of release sites using HARPA (Hamiltonian Acoustic Ray-tracing Program for the Atmosphere) and rawinsonde data collected near Albany and Buffalo, NY. The HARPA modeling shows that acoustic signals from the Cornell loft reached Jersey Hill only on a few release days with unusual atmospheric conditions, including August 13, and were launched at angles less than ~2° above horizontal, most likely from steep-sided terrain in

  6. A simple parameter can switch between different weak-noise-induced phenomena in a simple neuron model

    Science.gov (United States)

    Yamakou, Marius E.; Jost, Jürgen

    2017-10-01

    In recent years, several, apparently quite different, weak-noise-induced resonance phenomena have been discovered. Here, we show that at least two of them, self-induced stochastic resonance (SISR) and inverse stochastic resonance (ISR), can be related by a simple parameter switch in one of the simplest models, the FitzHugh-Nagumo (FHN) neuron model. We consider a FHN model with a unique fixed point perturbed by synaptic noise. Depending on the stability of this fixed point and whether it is located to either the left or right of the fold point of the critical manifold, two distinct weak-noise-induced phenomena, either SISR or ISR, may emerge. SISR is more robust to parametric perturbations than ISR, and the coherent spike train generated by SISR is more robust than that generated deterministically. ISR also depends on the location of initial conditions and on the time-scale separation parameter of the model equation. Our results could also explain why real biological neurons having similar physiological features and synaptic inputs may encode very different information.

  7. Economic Impact of Hearing Loss and Reduction of Noise-Induced Hearing Loss in the United States.

    Science.gov (United States)

    Neitzel, Richard L; Swinburn, Tracy K; Hammer, Monica S; Eisenberg, Daniel

    2017-01-01

    Hearing loss (HL) is pervasive and debilitating, and noise-induced HL is preventable by reducing environmental noise. Lack of economic analyses of HL impacts means that prevention and treatment remain a low priority for public health and environmental investment. This article estimates the costs of HL on productivity by building on established estimates for HL prevalence and wage and employment differentials between those with and without HL. We estimate that HL affects more than 13% of the working population. Not all HL can be prevented or treated, but if the 20% of HL resulting from excessive noise exposure were prevented, the economic benefit would be substantial-we estimate a range of $58 billion to $152 billion annually, with a core estimate of $123 billion. We believe this is a conservative estimate, because consideration of additional costs of HL, including health care and special education, would likely further increase the benefits associated with HL prevention. HL is costly and warrants additional emphasis in public and environmental health programs. This study represents an important first step in valuing HL prevention-in particular, prevention of noise-induced HL-where new policies and technologies appear promising.

  8. Comparison of Vestibular Evoked Myogenic Potential and Caloric Tests Findings in Noise Induced Hearing Loss-Affected and Healthy Individuals

    Directory of Open Access Journals (Sweden)

    Farinoosh Fakharnia

    2010-06-01

    Full Text Available Background and Aim: Balance disturbance is one of the non-auditory effects of noisy industrial environments that is usually neglected. The aim of the current study was to investigate the effect of occupational noise on vestibular system among workers with noise-induced hearing loss (NIHL, based on both vestibular evoked myogenic potentials (VEMP and caloric tests.Methods: Thirty male workers with noise-induced hearing loss and thirty male matched controls were examined by VEMP and caloric tests. Study parameters included unilateral weakness, p13 and n23 latencies, and p13-n23 amplitude. Caloric test was performed only for 20 patients.Results: No significant difference was observed in unilateral weakness between the two groups. On the other hand, the difference in mean latencies of p13 in the right ear (p=0.003 and left ear (p=0.01 was significant between the two groups. However, the difference in n23 latency was significant only in the right ear (p=0.03. There was no significant difference between groups in p13-n23 amplitude.Conclusion: It seems that pars inferior of vestibule is the susceptible part in individuals with NIHL. In general, abnormal findings in both VEMP and caloric tests were more common compared to functional symptoms such as vertigo, which may be due to central compensation and the symmetry of the disorder.

  9. [A cohort study on occupational noise induced hearing loss in workers at an iron and steel plant].

    Science.gov (United States)

    Yu, S F; Chen, G S; Jiao, J; Gu, G Z; Zhang, H L; Wang, X M; Zhou, W H; Wu, H; Li, Y H; Zheng, Y X

    2017-01-06

    Objective: To analyze the incidence rate of occupational noise-induced hearing loss in noise-exposed workers in an iron and steel plant from 2006 to 2015. Methods: Using a cohort study method, workers exposed to occupational noise from Jan 1, 2006 to Dec 12, 2015 were followed up and the pure tone hearing test was conducted. In total, 6 297 subjects completed two or more physical checks and the pure tone hearing test and were included in the analysis. The noise exposure level at the workplace and the equivalent continuous A-weighted sound pressure level for workers was monitored and the cumulative noise exposure dose was evaluated. The subjects were divided into low, middle and high exposure groups according to the noise exposure level, and the equivalent continuous A-weighted sound pressure level for 8 hours for each group was 80.6-85.0, 85.1-90.0 and 90.1-103.4 dB (A), respectively. While the RR and 95% CI were derived from unconditional logistic regression models. In logistic regression analysis, confounding factors such as age, gender, smoking habit, drinking habit, high temperature exposure and chemical hazards exposure level were controlled. Results: During the follow-up period, 392 cases of occupational noise-induced hearing loss were diagnosed among the 6 297 subjects, with an incidence rate of 6.23%; 318 cases of high-frequency hearing loss were diagnosed, with an incidence rate of 5.05%; and 74 cases of occupational noise-induced deafness were diagnosed, with an incidence rate of 1.18% . The incidence rates of hearing loss among the high, medium and low exposure groups were 9.22% (158/1 737), 6.49% (204/3 142) and 2.08% (30/1 442), respectively; the rates of high-frequency hearing loss were 7.41% (127/1 737), 5.25% (165/3 142) and 1.80% (26/1 442), respectively; and the rates of occupational noise-induced deafness were 1.81% (31/1 737), 1.24% (39/3 142) and 0.28% (4/1 442), respectively. For the groups corresponding to cumulative noise exposure doses of

  10. Noise-induced hearing loss among quarry workers in a north-eastern state of malaysia: a study on knowledge, attitude and practice.

    Science.gov (United States)

    Ismail, Ahmad Filza; Daud, Aziah; Ismail, Zaliha; Abdullah, Baharudin

    2013-09-01

    Noise is known to be one of the environmental and occupational hazards listed in the Factory and Machinery Act 1967. Quarries with loud deafening sounds from trucks and machineries pose the risk of noise-induced hearing loss to workers. This study was designed to assess the knowledge, attitude and practice towards noise-induced hearing loss and to determine the prevalence of noise-induced hearing loss and its associated factors among quarry workers in a north-eastern state of Malaysia. A cross-sectional study was conducted at six quarries in a north-eastern state of Malaysia, with 97 consented respondents who answered a validated version of a questionnaire and underwent pure tone audiogram. The respondents were male, aged between 18 to 50 years, working in the quarry area for at least 6-months duration with no family history of ear diseases. The mean percentage scores of knowledge, attitude and practice were 44 (11), 70 (10) and 28 (16) percent, respectively. The prevalence of noise-induced hearing loss was found to be 57 (95% CI: 47, 67) with 46 (84%) having mild and moderate noise-induced hearing loss, and 34 (62%) involved both ears. Multiple logistic regressions showed that age and practice score were the associated factors with odd ratios of 1.1 (95% CI: 1.1, 1.2; phearing loss was contributed by factors such as poor practice and old age.

  11. Raynaud′s phenomenon among men and women with noise-induced hearing loss in relation to vibration exposure

    Directory of Open Access Journals (Sweden)

    Hans Pettersson

    2014-01-01

    Full Text Available Raynaud′s phenomenon is characterized by constriction in blood supply to the fingers causing finger blanching, of white fingers (WF and is triggered by cold. Earlier studies found that workers using vibrating hand-held tools and who had vibration-induced white fingers (VWF had an increased risk for hearing loss compared with workers without VWF. This study examined the occurrence of Raynaud′s phenomenon among men and women with noise-induced hearing loss in relation to vibration exposure. All 342 participants had a confirmed noise-induced hearing loss medico legally accepted as work-related by AFA Insurance. Each subject answered a questionnaire concerning their health status and the kinds of exposures they had at the time when their hearing loss was first discovered. The questionnaire covered types of exposures, discomforts in the hands or fingers, diseases and medications affecting the blood circulation, the use of alcohol and tobacco and for women, the use of hormones and whether they had been pregnant. The participation rate was 41% (n = 133 with 38% (n = 94 for men and 50% (n = 39 for women. 84 men and 36 women specified if they had Raynaud′s phenomenon and also if they had used hand-held vibrating machines. Nearly 41% of them had used hand-held vibrating machines and 18% had used vibrating machines at least 2 h each workday. There were 23 men/6 women with Raynaud′s phenomenon. 37% reported WF among those participants who were exposed to hand-arm vibration (HAV and 15% among those not exposed to HAV. Among the participants with hearing loss with daily use of vibrating hand-held tools more than twice as many reports WF compared with participants that did not use vibrating hand-held tools. This could be interpreted as Raynaud′s phenomenon could be associated with an increased risk for noise-induced hearing loss. However, the low participation rate limits the generalization of the results from this study.

  12. Theory for the asymmetry in the auroral ionization density profile for the generation of auroral infrasonic waves

    International Nuclear Information System (INIS)

    Goodwin, P.A.

    1979-01-01

    Traveling pressure waves with periods from 10 to 100 seconds are generated in the lower ionosphere by auroral electrojet current filaments as they move supersonically in an equatorward direction. The infrasonic waves produced by the auroral motions propagate to the ground as highly directional bow waves that can be detected by infrasonic microphones on the surface. There is an asymmetry in the reception of auroral infrasonic waves (AIW) with respect to whether the auroral arcs are moving equatorward to poleward. In the literature it is suggested that the asymmetry may be due to anisotropic propagation conditions along the acoustic ray path from the E-region, where AIW are produced, to the surface. Some intrinsic property of the AIW generation mechanism itself has also been suggested as a possible explanation. In this thesis anisotropic propagation is eliminated as the cause of the AIW reception asymmetry. Theoretical calculations, beginning with a model of an auroral precipitation region, are presented to show that there can be a significant difference in the transverse ionization density profiles between an auroral arc that is moving equatorward and an arc that is moving poleward, for a given equatorward-directed E-region ambient electric field. The calculation has been accomplished by solving the equations of motion and continuity for the cross-sectional ionization density profile associated with the transverse motion of a filamentary auroral electrojet. Thus, it is shown that there is an asymmetry in the ionization profiles associated with moving arcs, and in their coupling, that is related to the relative direction of motion of the arc with respect to the ambient electric field, and that it is this asymmetry that is probably the cause of the observed AIW reception asymmetry

  13. Water-soluble Coenzyme Q10 formulation (Q-ter) promotes outer hair cell survival in a guinea pig model of noise induced hearing loss (NIHL).

    Science.gov (United States)

    Fetoni, Anna Rita; Piacentini, Roberto; Fiorita, Antonella; Paludetti, Gaetano; Troiani, Diana

    2009-02-27

    The mitochondrial respiratory chain is a powerful source of reactive oxygen species (ROS) also in noise induced hearing loss (NIHL) and anti-oxidants and free-radicals scavengers have been shown to attenuate the damage. Coenzyme Q(10) (CoQ(10)) or ubiquinone has a bioenergetic role as a component of the mithocondrial respiratory chain, it inhibits mitochondrial lipid peroxidation, inducing ATP production and it is involved in ROS removal and prevention of oxidative stress-induced apoptosis. However the therapeutic application of CoQ(10) is limited by the lack of solubility and poor bio- availability, therefore it is a challenge to improve its water solubility in order to ameliorate the efficacy in tissues and fluids. This study was conducted in a model of acoustic trauma in the guinea pig where the effectiveness of CoQ(10) was compared with a soluble formulation of CoQ(10) (multicomposite CoQ(10) Terclatrate, Q-ter) given intraperitoneally 1 h before and once daily for 3 days after pure tone noise exposure (6 kHz for 1 h at 120 dB SPL). Functional and morphological studies were carried out by measuring auditory brainstem responses, scanning electron microscopy for hair cell loss count, active caspase 3 staining and terminal deoxynucleotidyl transferase-mediated dUTP labelling assay in order to identify initial signs of apoptosis. Treatments decreased active caspase 3 expression and the number of apoptotic cells, but animals injected with Q-ter showed a greater degree of activity in preventing apoptosis and thus in improving hearing. These data confirm that solubility of Coenzyme Q(10) improves the ability of CoQ(10) in preventing oxidative injuries that result from mitochondrial dysfunction.

  14. Noise-induced extinction for a ratio-dependent predator-prey model with strong Allee effect in prey

    Science.gov (United States)

    Mandal, Partha Sarathi

    2018-04-01

    In this paper, we study a stochastically forced ratio-dependent predator-prey model with strong Allee effect in prey population. In the deterministic case, we show that the model exhibits the stable interior equilibrium point or limit cycle corresponding to the co-existence of both species. We investigate a probabilistic mechanism of the noise-induced extinction in a zone of stable interior equilibrium point. Computational methods based on the stochastic sensitivity function technique are applied for the analysis of the dispersion of random states near stable interior equilibrium point. This method allows to construct a confidence domain and estimate the threshold value of the noise intensity for a transition from the coexistence to the extinction.

  15. The Effect of PCDH15 Gene Variations on the Risk of Noise-induced Hearing Loss in a Chinese Population.

    Science.gov (United States)

    Xu, Xiang Rong; Wang, Jing Jing; Yang, Qiu Yue; Jiao, Jie; He, Li Hua; Yu, Shan Fa; Gu, Gui Zhen; Chen, Guo Shun; Zhou, Wen Hui; Wu, Hui; Li, Yan Hong; Zhang, Huan Ling; Zhang, Zeng Rui; Jin, Xian Ning

    2017-02-01

    Noise-induced hearing loss (NIHL) is a complex disease caused by interactions between environmental and genetic factors. This study investigated whether genetic variability in protocadherin related 15 (PCDH15) underlies an increased susceptibility to the development of NIHL in a Chinese population. The results showed that compared with the TT genotype of rs11004085, CT/CC genotypes were associated with an increased risk of NIHL [adjusted odds ratio (OR) = 2.64; 95% confidence interval (CI): 1.14-6.11, P = 0.024]. Additionally, significant interactions between the rs11004085 and rs978842 genetic variations and noise exposure were observed in the high-level exposure groups (P variations in PCDH15 modify the susceptibility to NIHL development in humans. Copyright © 2017 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  16. Opioid receptor subtypes mediating the noise-induced decreases in high-affinity choline uptake in the rat brain.

    Science.gov (United States)

    Lai, H; Carino, M A

    1992-07-01

    Acute (20 min) exposure to 100-dB white noise elicits a naltrexone-sensitive decrease in sodium-dependent high-affinity choline uptake in the frontal cortex and hippocampus of the rat. In the present study, the subtypes of opioid receptors involved were investigated by pretreating rats with microinjection of specific opioid-receptor antagonists into the lateral cerebroventricle before noise exposure. We found that the noise-induced decrease in high-affinity choline uptake in the hippocampus was blocked by pretreatment with either mu-, delta-, or kappa-opioid-receptor antagonists, whereas the effect of noise on frontal cortical high-affinity choline uptake was blocked by a mu- and delta- but not by a kappa-antagonist. These data further confirm the role of endogenous opioids in mediating the effects of noise on central cholinergic activity and indicate that different neural mechanisms are involved in the effects of noise on the frontal cortical and hippocampal cholinergic systems.

  17. Calculation of the neutron noise induced by periodic deformations of a large sodium-cooled fast reactor core

    International Nuclear Information System (INIS)

    Zylbersztejn, F.; Tran, H.N.; Pazsit, I.; Filliatre, P.; Jammes, C.

    2014-01-01

    The subject of this paper is the calculation of the neutron noise induced by small-amplitude stationary radial variations of the core size (core expansion/compaction, also called core flowering) of a large sodium-cooled fast reactor. The calculations were performed on a realistic model of the European Sodium Fast Reactor (ESFR) core with a thermal output of 3600 MW(thermal), using a multigroup neutron noise simulator. The multigroup cross sections and their fluctuations that represent the core geometry changes for the neutron noise calculations were generated by the code ERANOS. The space and energy dependences of the noise source represented by the core expansion/compaction and the induced neutron noise are calculated and discussed. (authors)

  18. A study of the possibility of acquiring noise-induced hearing loss by the use of personal cassette players (walkman).

    Science.gov (United States)

    Turunen-Rise, I; Flottorp, G; Tvete, O

    1991-01-01

    Playing various types of music on five selected personal cassette players (PCPs), A-weighted sound pressure levels (SPLs), together with octave band spectrum, were measured on KEMAR (Knowles Electronics Manikin for Acoustic Research). Maximum and equivalent SPLs were measured for various types of music, PCPs and for different gain (volume) settings. The measured SPL-values on KEMAR ear were transformed to field values outside the ear canal by means of corrections based on KEMAR's ear canal resonance curve--in order to compare measured values with the Norwegian national noise risk criteria. Temporary threshold shift (TTS) was measured after listening to PCP music for one hour in order to obtain additional information about possible risk of hearing damage. TTS values are presented for six subjects when playing two different pop music cassettes on one type PCP. Our analysis indicates that the risk for permanent noise-induced hearing loss from listening to PCP is very small for normal listening conditions.

  19. Using the extended parallel process model to prevent noise-induced hearing loss among coal miners in Appalachia

    Energy Technology Data Exchange (ETDEWEB)

    Murray-Johnson, L.; Witte, K.; Patel, D.; Orrego, V.; Zuckerman, C.; Maxfield, A.M.; Thimons, E.D. [Ohio State University, Columbus, OH (US)

    2004-12-15

    Occupational noise-induced hearing loss is the second most self-reported occupational illness or injury in the United States. Among coal miners, more than 90% of the population reports a hearing deficit by age 55. In this formative evaluation, focus groups were conducted with coal miners in Appalachia to ascertain whether miners perceive hearing loss as a major health risk and if so, what would motivate the consistent wearing of hearing protection devices (HPDs). The theoretical framework of the Extended Parallel Process Model was used to identify the miners' knowledge, attitudes, beliefs, and current behaviors regarding hearing protection. Focus group participants had strong perceived severity and varying levels of perceived susceptibility to hearing loss. Various barriers significantly reduced the self-efficacy and the response efficacy of using hearing protection.

  20. [Progressive noise induced hearing loss caused by hearing AIDS, a dilemma for the worker and the expert alike].

    Science.gov (United States)

    Feldmann, H

    2001-12-01

    Investigating cases of noise induced hearing loss the expert is often confronted with the situation that the hearing loss is progressive although the noise exposure has been reduced to almost non-damaging levels. Other causes such as age, hereditary deafness, head injuries, blasts, internal diseases can be excluded. Hearing aids as sources of damaging noise? By consulting the protocol of the hearing-aid acoustician and by own examinations the expert should obtain the following data: loudness level that yields best discrimination score of speech; level of discomfort for tones and speech, discrimination score that is achieved under free field condition with a speech level of 65 dB, using the hearing aids. Furthermore he should explore the circumstances under which the hearing aids are used: how many hours per day, at what occasions etc.? It is likely that in using the hearing aids they are adjusted to emit an intensity level identical to the one yielding the optimal discrimination score. If this e. g. is 100 dB and the hearing aids are used for 2 hours per day this would be equivalent to an exposure to industrial noise of 94 dB (A) for 8 hours daily without ear protection. Among all individuals working under industrial noise exposure today only about 1 - 2 % having unusually vulnerable inner ears will suffer a noise induced hearing loss. On the other hand workers in industrial noise are accustomed to loud noise levels, usually have a raised threshold of discomfort and therefore are likely to adjust their hearing aids to such high intensities. The expert will have to decide whether in an individual case the industrial noise exposure or the use of the hearing aids is the dominant risk for further damage. The consequences in respect to the regulations of the workers' health insurance are discussed.

  1. Molecular mechanisms underlying the protective effects of hydrogen-saturated saline on noise-induced hearing loss.

    Science.gov (United States)

    Chen, Liwei; Han, Mingkun; Lu, Yan; Chen, Daishi; Sun, Xuejun; Yang, Shiming; Sun, Wei; Yu, Ning; Zhai, Suoqiang

    2017-10-01

    This study aimed to explore the molecular mechanism of the protective effects of hydrogen-saturated saline on NIHL. Guinea pigs were divided into three groups: hydrogen-saturated saline; normal saline; and control. For saline administration, the guinea pigs were given daily abdominal injections 3 d before and 1 h before noise exposure. ABR were tested to examine cochlear physiology changes. The changes of 8-hydroxy-desoxyguanosine (8-HOdG), interleukin-1 (IL-1), interleukin-6 (IL-6), interleukin-10 (IL-10), tumor necrosis factor-α (TNF-α), intercellular cell adhesion molecule-1 (ICAM-1) and high mobility group box-1 protein (HMGB1) in the cochlea were also examined. The results showed that pre-treatment with hydrogen-saturated saline could significantly attenuate noise-induced hearing loss. The concentration of 8-HOdG was also significantly decreased in the hydrogen-saturated saline group compared with the normal saline group. After noise exposure, the concentrations of IL-1, IL-6, TNF-α, and ICAM-1 in the cochlea of guinea pigs in the hydrogen-saturated saline group were dramatically reduced compared to those in the normal saline group. The concentrations of HMGB-1 and IL-10 in the hydrogen-saturated saline group were significantly higher than in those in the normal saline group immediately and at 7 d after noise exposure. This study revealed for the first time the protective effects of hydrogen-saturated saline on noise-induced hearing loss (NIHL) are related to both the anti-oxidative activity and anti-inflammatory activity.

  2. Compensation claims for occupational noise induced hearing loss between 1998 and 2008: yearly incidence rates and trends in older workers.

    Science.gov (United States)

    Radi, Samia; Benke, Geza; Schaafsma, Frederieke; Sim, Malcolm

    2016-04-01

    To estimate yearly incidence rates for occupational noise induced hearing loss (ONIHL) claims and to describe occupational factors in relation to age for incident cases in Victoria, Australia, between 1998 and 2008. All compensation claims lodged for deafness between 1 July 1998 and 30 June 2008 in the working population covered by the Victorian compensation scheme were analysed. Denominators were provided from 1999-2000 and incidence rates were expressed per 100,000 workers for each financial year. Overall, 81.2% of the 4,518 claims lodged were accepted. Successful claimants were predominantly males (96.5%) and claimants aged 56 to 65 years formed half the overall claims. The number of accepted claims was almost five times higher in 2007-08 than 1998-99. The highest rise was in claimants aged 56 years and above, particularly in those after retirement age. The number of claims and yearly incidence rates (IR) more than doubled over the period (240 claims and IR of 15.1 per 100,000 workers in 1999-2000 versus 669 claims and IR of 34.2 in 2007-08) with a sharp increase from 2004-05 to almost double within one single year and remained at high levels afterwards. The dramatic increase in eligible claims may reflect an increase in awareness of entitlements among workers eligible to make a successful claim. This awareness may be the result of increased opportunities for screening coinciding with changes in regulations. Older workers who worked in smaller workplaces may also be targeted by services providers as they combine occupational noise induced hearing loss (ONIHL) and presbycusis (hearing loss due to age), but this hypothesis needs further evaluation. © 2015 Public Health Association of Australia.

  3. Infrasonic harmonic tremor and degassing bursts from Halema'uma'u Crater, Kilauea Volcano, Hawaii

    Science.gov (United States)

    Fee, David; Garcés, Milton; Patrick, Matt; Chouet, Bernard; Dawson, Phil; Swanson, Donald A.

    2010-01-01

    The formation, evolution, collapse, and subsequent resurrection of a vent within Halema'uma'u Crater, Kilauea Volcano, produced energetic and varied degassing signals recorded by a nearby infrasound array between 2008 and early 2009. After 25 years of quiescence, a vent-clearing explosive burst on 19 March 2008 produced a clear, complex acoustic signal. Near-continuous harmonic infrasonic tremor followed this burst until 4 December 2008, when a period of decreased degassing occurred. The tremor spectra suggest volume oscillation and reverberation of a shallow gas-filled cavity beneath the vent. The dominant tremor peak can be sustained through Helmholtz oscillations of the cavity, while the secondary tremor peak and overtones are interpreted assuming acoustic resonance. The dominant tremor frequency matches the oscillation frequency of the gas emanating from the vent observed by video. Tremor spectra and power are also correlated with cavity geometry and dynamics, with the cavity depth estimated at ~219 m and volume ~3 x 106 m3 in November 2008. Over 21 varied degassing bursts were observed with extended burst durations and frequency content consistent with a transient release of gas exciting the cavity into resonance. Correlation of infrasound with seismicity suggests an open system connecting the atmosphere to the seismic excitation process at depth. Numerous degassing bursts produced very long period (0.03-0.1 Hz) infrasound, the first recorded at Kilauea, indicative of long-duration atmospheric accelerations. Kilauea infrasound appears controlled by the exsolution of gas from the magma, and the interaction of this gas with the conduits and cavities confining it.

  4. Stress

    Science.gov (United States)

    ... can be life-saving. But chronic stress can cause both physical and mental harm. There are at least three different types of stress: Routine stress related to the pressures of work, family, and other daily responsibilities Stress brought about ...

  5. Cochlea hair cell rescue after a noise-induced hearing loss using a low level laser therapy (LLLT)

    Science.gov (United States)

    Rhee, Chung-Ku; Bahk, Chan Woong; Jung, Jae Yun; Ahn, Jin-Chul; Suh, Myung-Whan

    2011-03-01

    Aim: To see the effect of LLLT on noise-induced hearing loss. Methods: Eleven rats were exposed to noise (120 dB, 16 kHz, 6 h) and left ears were irradiated at 60J/cm2, 830 nm laser for 12 days. Right ears were control. Hearing levels were measured at frequencies of 4, 8, 12, 16, 32 kHz before noise exposure and after 12th irradiations. Results: The initial hearing levels were 26.5+/-4.7, 24.5+/-5.0, 24.0+/-5.2, 24.0+/-3.2, 24.5+/-5.5 dB SPL. After noise exposure, thresholds were 63.5+/-15.1, 64+/-16.8, 71.5+/-11.3, 73.5+/-15.6, 67.5+/-14.4 dB SPL in 4, 8, 12, 16, 32 kHz. After 12th irradiation, thresholds of treated ears recovered significantly 21+/-4.2, 20+/-3.5, 24+/-11.9, 24+/-12.9, 21+/-2.2 dB SPL and that of the untreated right ears measured 36.3+/-22.9, 45+/-15.8, 66.3+/-22.9, 50+/-16.8, 43.8+/-21.4 dB SPL. Conclusion: LLLT may promote recovery of hearing after noiseinduced hearing loss.

  6. Effects of the network structure and coupling strength on the noise-induced response delay of a neuronal network

    International Nuclear Information System (INIS)

    Ozer, Mahmut; Uzuntarla, Muhammet

    2008-01-01

    The Hodgkin-Huxley (H-H) neuron model driven by stimuli just above threshold shows a noise-induced response delay with respect to time to the first spike for a certain range of noise strengths, an effect called 'noise delayed decay' (NDD). We study the response time of a network of coupled H-H neurons, and investigate how the NDD can be affected by the connection topology of the network and the coupling strength. We show that the NDD effect exists for weak and intermediate coupling strengths, whereas it disappears for strong coupling strength regardless of the connection topology. We also show that although the network structure has very little effect on the NDD for a weak coupling strength, the network structure plays a key role for an intermediate coupling strength by decreasing the NDD effect with the increasing number of random shortcuts, and thus provides an additional operating regime, that is absent in the regular network, in which the neurons may also exploit a spike time code

  7. Noise-induced hearing loss in agriculture: Creating partnerships to overcome barriers and educate the community on prevention

    Directory of Open Access Journals (Sweden)

    Janet J Ehlers

    2011-01-01

    Full Text Available Noise-induced hearing loss (NIHL is a common and preventable injury for farmers. Farmers are frequently exposed to excessive noise, ranking among the top three occupations and industries with the highest risk for hearing loss. Use of hearing protection among farmers is not common. Although the age when NIHL begins among farmers is unknown, its prevalence is higher among male adolescents who live and work on farms. The purpose of this paper is to describe how NIOSH created partnerships to promote hearing conservation for this hard-to-reach population. Partnerships included organizations and individuals who were trusted sources of information for the target population, young farmers 14-35 years of age and their families, and those who had linkages in rural communities. NIOSH engaged partners through exhibits and train-the-trainer workshops at state or national conventions. NIOSH workshops included basic information on NIHL as well as information on free or low-lost resources that participants could use in training others at schools and community events. People with hearing conservation expertise have an important role and many opportunities to improve the knowledge and implementation of hearing conservation among those in agriculture.

  8. Loss of Myh14 Increases Susceptibility to Noise-Induced Hearing Loss in CBA/CaJ Mice

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    Xiaolong Fu

    2016-01-01

    Full Text Available MYH14 is a member of the myosin family, which has been implicated in many motile processes such as ion-channel gating, organelle translocation, and the cytoskeleton rearrangement. Mutations in MYH14 lead to a DFNA4-type hearing impairment. Further evidence also shows that MYH14 is a candidate noise-induced hearing loss (NIHL susceptible gene. However, the specific roles of MYH14 in auditory function and NIHL are not fully understood. In the present study, we used CRISPR/Cas9 technology to establish a Myh14 knockout mice line in CBA/CaJ background (now referred to as Myh14−/− mice and clarify the role of MYH14 in the cochlea and NIHL. We found that Myh14−/− mice did not exhibit significant hearing loss until five months of age. In addition, Myh14−/− mice were more vulnerable to high intensity noise compared to control mice. More significant outer hair cell loss was observed in Myh14−/− mice than in wild type controls after acoustic trauma. Our findings suggest that Myh14 may play a beneficial role in the protection of the cochlea after acoustic overstimulation in CBA/CaJ mice.

  9. The use of hearing protection devices with approach risk perception of noise induced hearing loss in several manufacturing industry

    Directory of Open Access Journals (Sweden)

    Behzad Fouladi Deahghi

    2015-06-01

    Full Text Available Background & Objective : Noise is a widespread physical agent and although is a most risk factors in workplaces that workers of health to exposed. Thus, different actions is done for reduce exposure to it in work places, which one of them is use of hearing protection devices. The use of hearing protection devices with approach risk perception of noise induced hearing loss in several manufacturing industry Method: This study was Cross-sectional study and done in five industrial unit with a sound pressure level more of 85 dB-A with the participation of 340 workers. To collect data , individual risk perception and self-investigator questionnaires were used. After collecting data, statistical analysis including Cronbach's alpha and regression were used to analyze the data. Results : Range use of hearing protection devices during shifts work by workers, respectively equal to: 50.4% sometimes, 31.58% never and 18.2% at all times. Also, results indicate significant differences between individual differences and hearing protection devices. Conclusion : Results of this study showed that individual risk perception as an important factor, can do a significant role in predicting the behavior of personals in the use of hearing protection devices, which should be considered in any design and implementation of hearing protection program.

  10. A Method for Calculating the Area of Zostera marina Leaves from Digital Images with Noise Induced by Humidity Content

    Directory of Open Access Journals (Sweden)

    Cecilia Leal-Ramirez

    2014-01-01

    Full Text Available Despite the ecological importance of eelgrass, nowadays anthropogenic influences have produced deleterious effects in many meadows worldwide. Transplantation plots are commonly used as a feasible remediation scheme. The characterization of eelgrass biomass and its dynamics is an important input for the assessment of the overall status of both natural and transplanted populations. Particularly, in restoration plots it is desirable to obtain nondestructive assessments of these variables. Allometric models allow the expression of above ground biomass and productivity of eelgrass in terms of leaf area, which provides cost effective and nondestructive assessments. Leaf area in eelgrass can be conveniently obtained by the product of associated length and width. Although these variables can be directly measured on most sampled leaves, digital image methods could be adapted in order to simplify measurements. Nonetheless, since width to length ratios in eelgrass leaves could be even negligible, noise induced by leaf humidity content could produce misidentification of pixels along the peripheral contour of leaves images. In this paper, we present a procedure aimed to produce consistent estimations of eelgrass leaf area in the presence of the aforementioned noise effects. Our results show that digital image procedures can provide reliable, nondestructive estimations of eelgrass leaf area.

  11. The music listening preferences and habits of youths in Singapore and its relation to leisure noise-induced hearing loss.

    Science.gov (United States)

    Lee, Gary Jek Chong; Lim, Ming Yann; Kuan, Angeline Yi Wei; Teo, Joshua Han Wei; Tan, Hui Guang; Low, Wong Kein

    2014-02-01

    Noise-induced hearing loss (NIHL) is a preventable condition, and much has been done to protect workers from it. However, thus far, little attention has been given to leisure NIHL. The purpose of this study is to determine the possible music listening preferences and habits among young people in Singapore that may put them at risk of developing leisure NIHL. In our study, the proportion of participants exposed to > 85 dBA for eight hours a day (time-weighted average) was calculated by taking into account the daily number of hours spent listening to music and by determining the average sound pressure level at which music was listened to. A total of 1,928 students were recruited from Temasek Polytechnic, Singapore. Of which, 16.4% of participants listened to portable music players with a time-weighted average of > 85 dBA for 8 hours. On average, we found that male students were more likely to listen to music at louder volumes than female students (p students in our study listened to louder music than the Chinese students (p leisure NIHL from music delivered via earphones. As additional risks due to exposure to leisure noise from other sources was not taken into account, the extent of the problem of leisure NIHL may be even greater. There is a compelling need for an effective leisure noise prevention program among young people in Singapore.

  12. [Transcultural adaptation of an instrument to evaluate hearing handicap in workers with noise-induced hearing loss].

    Science.gov (United States)

    Holanda, Wanessa Tenório Gonçalves; de Lima, Maria Luiza Carvalho; Figueiroa, José Natal

    2011-01-01

    The noise-induced hearing loss (NIHL) is a chronic and irreversible disease resulting of the exposure to noise in high levels at work. Even in the beginning, this hearing loss can damage in many degrees the worker's quality of life. Before this study, there wasn't an instrument, in Portuguese, to evaluate the psychosocial disadvantages of workers with NIHL. The aim of this research was to make a transcultural adaptation of an especific instrument to evaluate the hearing handicap from the original language to Portuguese, and check the reliability and legitimacy. The selected instrument passed by a process of semantic equivalence that was conducted in five stages: translation, back translation, critical appraisal of the versions, pre-test and a final review by a multi-professional group to develop a consensual version of the instrument for current use in Brazil. The instrument called "Inabilities Scale and Hearing Handicap" had, in general, acceptable psychometric measures, considering the little size of the sample and the fact that workers' hearing loss weren't too significant. Therefore, the Portuguese version of this instrument needs to be further tested in a representative sample of Brazilian workers with NIHL to ratify its utility in order to evaluate hearing handicap in this population.

  13. Noise-induced plasticity of KCNQ2/3 and HCN channels underlies vulnerability and resilience to tinnitus

    Science.gov (United States)

    Li, Shuang; Kalappa, Bopanna I; Tzounopoulos, Thanos

    2015-01-01

    Vulnerability to noise-induced tinnitus is associated with increased spontaneous firing rate in dorsal cochlear nucleus principal neurons, fusiform cells. This hyperactivity is caused, at least in part, by decreased Kv7.2/3 (KCNQ2/3) potassium currents. However, the biophysical mechanisms underlying resilience to tinnitus, which is observed in noise-exposed mice that do not develop tinnitus (non-tinnitus mice), remain unknown. Our results show that noise exposure induces, on average, a reduction in KCNQ2/3 channel activity in fusiform cells in noise-exposed mice by 4 days after exposure. Tinnitus is developed in mice that do not compensate for this reduction within the next 3 days. Resilience to tinnitus is developed in mice that show a re-emergence of KCNQ2/3 channel activity and a reduction in HCN channel activity. Our results highlight KCNQ2/3 and HCN channels as potential targets for designing novel therapeutics that may promote resilience to tinnitus. DOI: http://dx.doi.org/10.7554/eLife.07242.001 PMID:26312501

  14. Prevention of the Evolution of Workers' Hearing Loss from Noise-Induced Hearing Loss in Noisy Environments through a Hearing Conservation Program

    OpenAIRE

    Fonseca, Vinicius Ribas; Marques, Jair; Panegalli, Flavio; Gonçalves, Claudia Giglio de Oliveira; Souza, Wesley

    2016-01-01

    Introduction Noise-induced hearing loss (NIHL) is a serious problem for workers and therefore for businesses. The hearing conservation program (HCP) is a set of coordinated measures to prevent the development or evolution of occupational hearing loss, which involves a continuous and dynamic process of implementation of hearing conservation routines through anticipation, recognition, evaluation, and subsequent control of the occurrence of existing environmental risks or of those thatmay exist...

  15. Prevalence and risk factors of noise-induced hearing loss among liquefied petroleum gas (LPG) cylinder infusion workers in Taiwan.

    Science.gov (United States)

    Chang, Shu-Ju; Chang, Chin-Kuo

    2009-12-01

    We assessed the exposure levels of noise, estimated prevalence, and identify risk factors of noise-induced hearing loss (NIHL) among male workers with a cross-sectional study in a liquefied petroleum gas cylinder infusion factory in Taipei City. Male in-field workers exposed to noise and administrative controls were enrolled in 2006 and 2007. Face-to-face interviews were applied for demographics, employment history, and drinking/smoking habit. We then performed the measurements on noise levels in field and administration area, and hearing thresholds on study subjects with standard apparatus and protocols. Existence of hearing loss > 25 dBHL for the average of 500 Hz, 1 kHz, and 2 kHz was accordingly determined for NIHL. The effects from noise exposure, predisposing characteristics, employment-related factors, and personal habits to NIHL were estimated by univariate and multivariate logistic regressions. A total of 75 subjects were involved in research and 56.8% of in-field workers had NIHL. Between the in-field and administration groups, hearing thresholds on the worse ear showed significant differences at frequencies of 4 k, 6 k, and 8 kHz with aging considered. Adjusted odds ratio for field noise exposure (OR=99.57, 95% CI: 3.53, 2,808.74) and frequent tea or coffee consumption (OR=0.03, 95% CI: 0.01, 0.51) were found significant. Current study addressed NIHL in a specific industry in Taiwan. Further efforts in minimizing its impact are still in need.

  16. Noise-induced transitions at a Hopf bifurcation in a first-order delay-differential equation

    International Nuclear Information System (INIS)

    Longtin, A.

    1991-01-01

    The influence of colored noise on the Hopf bifurcation in a first-order delay-differential equation (DDE), a model paradigm for nonlinear delayed feedback systems, is considered. First, it is shown, using a stability analysis, how the properties of the DDE depend on the ratio R of system delay to response time. When this ratio is small, the DDE behaves more like a low-dimensional system of ordinary differential equations (ODE's); when R is large, one obtains a singular perturbation limit in which the behavior of the DDE approaches that of a discrete time map. The relative magnitude of the additive and multiplicative noise-induced postponements of the Hopf bifurcation are numerically shown to depend on the ratio R. Although both types of postponements are minute in the large-R limit, they are almost equal due to an equivalence of additive and parametric noise for discrete time maps. When R is small, the multiplicative shift is larger than the additive one at large correlation times, but the shifts are equal for small correlation times. In fact, at constant noise power, the postponement is only slightly affected by the correlation time of the noise, except when the noise becomes white, in which case the postponement drastically decreases. This is a numerical study of the stochastic Hopf bifurcation, in ODE's or DDE's, that looks at the effect of noise correlation time at constant power. Further, it is found that the slope at the fixed point averaged over the stochastic-parameter motion acts, under certain conditions, as a quantitative indicator of oscillation onset in the presence of noise. The problem of how properties of the DDE carry over to ODE's and to maps is discussed, along with the proper theoretical framework in which to study nonequilibrium phase transitions in this class of functional differential equations

  17. Genome-wide association study identifies nox3 as a critical gene for susceptibility to noise-induced hearing loss.

    Directory of Open Access Journals (Sweden)

    Joel Lavinsky

    2015-04-01

    Full Text Available In the United States, roughly 10% of the population is exposed daily to hazardous levels of noise in the workplace. Twin studies estimate heritability for noise-induced hearing loss (NIHL of approximately 36%, and strain specific variation in sensitivity has been demonstrated in mice. Based upon the difficulties inherent to the study of NIHL in humans, we have turned to the study of this complex trait in mice. We exposed 5 week-old mice from the Hybrid Mouse Diversity Panel (HMDP to a 10 kHz octave band noise at 108 dB for 2 hours and assessed the permanent threshold shift 2 weeks post exposure using frequency specific stimuli. These data were then used in a genome-wide association study (GWAS using the Efficient Mixed Model Analysis (EMMA to control for population structure. In this manuscript we describe our GWAS, with an emphasis on a significant peak for susceptibility to NIHL on chromosome 17 within a haplotype block containing NADPH oxidase-3 (Nox3. Our peak was detected after an 8 kHz tone burst stimulus. Nox3 mutants and heterozygotes were then tested to validate our GWAS. The mutants and heterozygotes demonstrated a greater susceptibility to NIHL specifically at 8 kHz both on measures of distortion product otoacoustic emissions (DPOAE and on auditory brainstem response (ABR. We demonstrate that this sensitivity resides within the synaptic ribbons of the cochlea in the mutant animals specifically at 8 kHz. Our work is the first GWAS for NIHL in mice and elucidates the power of our approach to identify tonotopic genetic susceptibility to NIHL.

  18. Modeling the Unites States government's economic cost of noise-induced hearing loss for a military population.

    Science.gov (United States)

    Tufts, Jennifer B; Weathersby, Paul K; Rodriguez, Francisco A

    2010-05-01

    The purpose of this paper is to demonstrate the feasibility and utility of developing economic cost models for noise-induced hearing loss (NIHL). First, we outline an economic model of NIHL for a population of US Navy sailors with an "industrial"-type noise exposure. Next, we describe the effect on NIHL-related cost of varying the two central model inputs--the noise-exposure level and the duration of exposure. Such an analysis can help prioritize promising areas, to which limited resources to reduce NIHL-related costs should be devoted. NIHL-related costs borne by the US government were computed on a yearly basis using a finite element approach that took into account varying levels of susceptibility to NIHL. Predicted hearing thresholds for the population were computed with ANSI S3.44-1996 and then used as the basis for the calculation of NIHL-related costs. Annual and cumulative costs were tracked. Noise-exposure level and duration were systematically varied to determine their effects on the expected lifetime NIHL-related cost of a specific US Navy sailor population. Our nominal noise-exposure case [93 dB(A) for six years] yielded a total expected lifetime cost of US $13,472 per sailor, with plausible lower and upper bounds of US $2,500 and US $26,000. Starting with the nominal case, a decrease of 50% in exposure level or duration would yield cost savings of approximately 23% and 19%, respectively. We concluded that a reduction in noise level would be more somewhat more cost-effective than the same percentage reduction in years of exposure. Our economic cost model can be used to estimate the changes in NIHL-related costs that would result from changes in noise-exposure level and/or duration for a single military population. Although the model is limited at present, suggestions are provided for adapting it to civilian populations.

  19. Early indication of noise-induced hearing loss from PMP use in adolescents: A cross-sectional analysis

    Directory of Open Access Journals (Sweden)

    Diana C Colon

    2016-01-01

    Full Text Available Context: Distortion product otoacoustic emissions (DPOAEs may indicate preclinical noise-induced hearing loss (NIHL in adolescents from unsafe personal music player (PMP use. Aims: The objective, therefore, was to observe preclinical signs of NIHL in 9th grade adolescents with clinically normal hearing by comparing DPOAE signals between different levels of A-weighted equivalent PMP exposure. Settings and Design: Subjects were recruited from all secondary-level schools located in the city of Regensburg, Germany during two academic years 2009/2010 and 2010/2011. Subjects and Methods: A-weighted equivalent sound pressure levels (SPLs for a 40-hour work week (LAeq,40h were estimated from questionnaire responses on output and duration of PMP use of the previous week. Subjects were then categorized into four levels of exposure: 85 to <90, and ≥90 A-weighted Decibel [dB(A]. DPOAE signals were collected by trained audiological staff, applying a standard optimized protocol, at the Department of Otorhinolaryngology of the University Hospital Regensburg. Statistical Analysis Used: Mean DPOAE signals were compared between levels by unpaired t test. Novel linear regression models adjusting for other leisure noise exposures and with outcome variables DPoutcome and 4 kilo Hertz (kHz DPOAEs estimated effects between levels. Results: A total of 1468 subjects (56% female, mostly aged 15 or 16 years were available for analysis. Comparison of DPOAE means by PMP exposure typically showed no greater than 1 dB difference between groups. In fact, comparisons between ≥90 dB(A and <80 dB(A presented the least differences in magnitude. Both DPoutcome and 4 kHz linear regression models presented a weak association with the 4-level PMP exposure variable. An expected dose-response to PMP exposure was not observed in any analyses. Conclusions: DPOAE signal strength alone cannot indicate preclinical NIHL in adolescents.

  20. Analysis of serum microRNA expression in male workers with occupational noise-induced hearing loss

    Directory of Open Access Journals (Sweden)

    Y.H. Li

    2018-01-01

    Full Text Available Occupational noise-induced hearing loss (ONIHL is a prevalent occupational disorder that impairs auditory function in workers exposed to prolonged noise. However, serum microRNA expression in ONIHL subjects has not yet been studied. We aimed to compare the serum microRNA expression profiles in male workers of ONIHL subjects and controls. MicroRNA microarray analysis revealed that four serum microRNAs were differentially expressed between controls (n=3 and ONIHL subjects (n=3. Among these microRNAs, three were upregulated (hsa-miR-3162-5p, hsa-miR-4484, hsa-miR-1229-5p and one was downregulated (hsa-miR-4652-3p in the ONIHL group (fold change >1.5 and Pbon value <0.05. Real time quantitative PCR was conducted for validation of the microRNA expression. Significantly increased serum levels of miR-1229-5p were found in ONIHL subjects compared to controls (n=10 for each group; P<0.05. A total of 659 (27.0% genes were predicted as the target genes of miR-1229-5p. These genes were involved in various pathways, such as mitogen-activated protein kinase (MAPK signaling pathway. Overexpression of miR-1229-5p dramatically inhibited the luciferase activity of 3′ UTR segment of MAPK1 (P<0.01. Compared to the negative control, HEK293T cells expressing miR-1229-5p mimics showed a significant decline in mRNA levels of MAPK1 (P<0.05. This preliminary study indicated that serum miR-1229-5p was significantly elevated in ONIHL subjects. Increased miR-1229-5p may participate in the pathogenesis of ONIHL through repressing MAPK1 signaling.

  1. Analysis of serum microRNA expression in male workers with occupational noise-induced hearing loss.

    Science.gov (United States)

    Li, Y H; Yang, Y; Yan, Y T; Xu, L W; Ma, H Y; Shao, Y X; Cao, C J; Wu, X; Qi, M J; Wu, Y Y; Chen, R; Hong, Y; Tan, X H; Yang, L

    2018-01-11

    Occupational noise-induced hearing loss (ONIHL) is a prevalent occupational disorder that impairs auditory function in workers exposed to prolonged noise. However, serum microRNA expression in ONIHL subjects has not yet been studied. We aimed to compare the serum microRNA expression profiles in male workers of ONIHL subjects and controls. MicroRNA microarray analysis revealed that four serum microRNAs were differentially expressed between controls (n=3) and ONIHL subjects (n=3). Among these microRNAs, three were upregulated (hsa-miR-3162-5p, hsa-miR-4484, hsa-miR-1229-5p) and one was downregulated (hsa-miR-4652-3p) in the ONIHL group (fold change >1.5 and Pbon value <0.05). Real time quantitative PCR was conducted for validation of the microRNA expression. Significantly increased serum levels of miR-1229-5p were found in ONIHL subjects compared to controls (n=10 for each group; P<0.05). A total of 659 (27.0%) genes were predicted as the target genes of miR-1229-5p. These genes were involved in various pathways, such as mitogen-activated protein kinase (MAPK) signaling pathway. Overexpression of miR-1229-5p dramatically inhibited the luciferase activity of 3' UTR segment of MAPK1 (P<0.01). Compared to the negative control, HEK293T cells expressing miR-1229-5p mimics showed a significant decline in mRNA levels of MAPK1 (P<0.05). This preliminary study indicated that serum miR-1229-5p was significantly elevated in ONIHL subjects. Increased miR-1229-5p may participate in the pathogenesis of ONIHL through repressing MAPK1 signaling.

  2. Exposure to music and noise-induced hearing loss (NIHL among professional pop/rock/jazz musicians

    Directory of Open Access Journals (Sweden)

    Dana N Halevi-Katz

    2015-01-01

    Full Text Available Noise-induced hearing loss (NIHL has been extensively studied in industrial work environments. With the advent of new technologies, loud music has been increasingly affecting listeners outside of the industrial setting. Most research on the effects of music and hearing loss has focused on classical musicians. The purpose of the current study was to examine the relationship between the amount of experience a professional pop/rock/jazz musician has and objective and subjective variables of the musician′s hearing loss. This study also examined professional pop/rock/jazz musicians′ use of hearing protection devices in relation to the extent of their exposure to amplified music. Forty-four pop/rock/jazz musicians were interviewed using the Pop/Rock/Jazz Musician′s Questionnaire (PRJMQ in order to obtain self-reported symptoms of tinnitus and hyperacusis. Forty-two of the subjects were also tested for air-conduction hearing thresholds in the frequency range of 1-8 kHz. Results show that the extent of professional pop/rock/jazz musicians′ exposure to amplified music was related to both objective and subjective variables of hearing loss: Greater musical experience was positively linked to higher hearing thresholds in the frequency range of 3-6 kHz and to the subjective symptom of tinnitus. Weekly hours playing were found to have a greater effect on hearing loss in comparison to years playing. Use of hearing protection was not linked to the extent of exposure to amplified music. It is recommended that further research be conducted with a larger sample, in order to gain a greater understanding of the detrimental effects of hours playing versus years playing.

  3. Association of genetic variations in FOXO3 gene with susceptibility to noise induced hearing loss in a Chinese population.

    Directory of Open Access Journals (Sweden)

    Haoran Guo

    Full Text Available Noise induced hearing loss (NIHL, a multifactorial disease involving both genetic and environmental factors, is one of the most important occupational health hazards. Nonetheless, the influence of FOXO3 variants on NIHL risk have not been illuminated. This research was conducted to explore the effects of FOXO3 polymorphisms on individual susceptibility to NIHL. A total of 2689 industrial workers from one textile factory of east China were recruited to participate in the current research. Venous blood was collected, questionnaire and pure-tone audiometry (PTA was conducted by specialist physicians. Then, we performed genotyping of three selected SNPs (rs2802292, rs10457180, and rs12206094 in FOXO3 gene in 566 NIHL patients and 566 controls. Subsequently, the main effects of genotype and its interactions were evaluated. Our results revealed that individuals with the G allele of rs2802292, G allele of rs10457180, T allele of rs12206094 (OR = 1.43, 1.43, and 1.31 respectively and the haplotype GAC and others (TGT/GGT/GGC/GAT (rs2802292-rs10457180-rs12206094 (OR = 1.49 and 2.09 respectively are associated with an increased risk of NIHL in a Chinese population. Stratified analysis showed that an increased NIHL risk was found in the subjects who exposed to noise >16 years with rs2802292 GG/GT and rs10457180 AG/GG genotype with an OR of 1.62 and 1.66 respectively. Multifactor dimensionality reduction analysis indicated that rs10457180, rs2802292, and rs12206094 have interactions and are related to increased NIHL risk (OR = 1.53. The genetic polymorphism rs2802292, rs10457180, and rs12206094 within FOXO3 gene are associated with an increased risk of NIHL in a Chinese population and have potential to be biomarkers for noise exposed workers.

  4. Exposure to music and noise-induced hearing loss (NIHL) among professional pop/rock/jazz musicians.

    Science.gov (United States)

    Halevi-Katz, Dana N; Yaakobi, Erez; Putter-Katz, Hanna

    2015-01-01

    Noise-induced hearing loss (NIHL) has been extensively studied in industrial work environments. With the advent of new technologies, loud music has been increasingly affecting listeners outside of the industrial setting. Most research on the effects of music and hearing loss has focused on classical musicians. The purpose of the current study was to examine the relationship between the amount of experience a professional pop/rock/jazz musician has and objective and subjective variables of the musician's hearing loss. This study also examined professional pop/rock/jazz musicians' use of hearing protection devices in relation to the extent of their exposure to amplified music. Forty-four pop/rock/jazz musicians were interviewed using the Pop/Rock/Jazz Musician's Questionnaire (PRJMQ) in order to obtain self-reported symptoms of tinnitus and hyperacusis. Forty-two of the subjects were also tested for air-conduction hearing thresholds in the frequency range of 1-8 kHz. Results show that the extent of professional pop/rock/jazz musicians' exposure to amplified music was related to both objective and subjective variables of hearing loss: Greater musical experience was positively linked to higher hearing thresholds in the frequency range of 3-6 kHz and to the subjective symptom of tinnitus. Weekly hours playing were found to have a greater effect on hearing loss in comparison to years playing. Use of hearing protection was not linked to the extent of exposure to amplified music. It is recommended that further research be conducted with a larger sample, in order to gain a greater understanding of the detrimental effects of hours playing versus years playing.

  5. The association between low levels of lead in blood and occupational noise-induced hearing loss in steel workers

    International Nuclear Information System (INIS)

    Hwang, Yaw-Huei; Chiang, Han-Yueh; Yen-Jean, Mei-Chu; Wang, Jung-Der

    2009-01-01

    As the use of leaded gasoline has ceased in the last decade, background lead exposure has generally been reduced. The aim of this study was to examine the effect of low-level lead exposure on human hearing loss. This study was conducted in a steel plant and 412 workers were recruited from all over the plant. Personal information such as demographics and work history was obtained through a questionnaire. All subjects took part in an audiometric examination of hearing thresholds, for both ears, with air-conducted pure tones at frequencies of 500, 1000, 2000, 3000, 4000, 6000 and 8000 Hz. Subjects' blood samples were collected and analyzed for levels of manganese, copper, zinc, arsenic, cadmium and lead with inductive couple plasma-mass spectrometry. Meanwhile, noise levels in different working zones were determined using a sound level meter with A-weighting network. Only subjects with hearing loss difference of no more than 15 dB between both ears and had no congenital abnormalities were included in further data analysis. Lead was the only metal in blood found significantly correlated with hearing loss for most tested sound frequencies (p < 0.05 to p < 0.0001). After adjustment for age and noise level, the logistic regression model analysis indicated that elevated blood lead over 7 μg/dL was significantly associated with hearing loss at the sound frequencies of 3000 through 8000 Hz with odds ratios raging from 3.06 to 6.26 (p < 0.05 ∼ p < 0.005). We concluded that elevated blood lead at level below 10 μg/dL might enhance the noise-induced hearing loss. Future research needs to further explore the detailed mechanism.

  6. The association between low levels of lead in blood and occupational noise-induced hearing loss in steel workers

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Yaw-Huei [Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University, Taipei, Taiwan, ROC Rm. 735, 17, Xu-Zhou Rd., Taipei, Taiwan, ROC (China); Department of Public Health, College of Public Health, National Taiwan University, Taipei, Taiwan, ROC Rm. 735, 17, Xu-Zhou Rd., Taipei, Taiwan, ROC (China); Chiang, Han-Yueh [Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University, Taipei, Taiwan, ROC Rm. 735, 17, Xu-Zhou Rd., Taipei, Taiwan, ROC (China); Yen-Jean, Mei-Chu [Division of Family Medicine, E-Da Hospital, Taiwan, ROC 1, E-Da Rd., Jiau-Shu Tsuen, Yan-Chau Shiang, Kaohsiung County, Taiwan, ROC (China); I-Shou University, Kaohsiung County, Taiwan, ROC 1, Sec. 1, Syuecheng Rd., Da-Shu Shiang, Kaohsiung County, Taiwan, ROC (China); Wang, Jung-Der, E-mail: jdwang@ntu.edu.tw [Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University, Taipei, Taiwan, ROC Rm. 735, 17, Xu-Zhou Rd., Taipei, Taiwan, ROC (China); Department of Public Health, College of Public Health, National Taiwan University, Taipei, Taiwan, ROC Rm. 735, 17, Xu-Zhou Rd., Taipei, Taiwan, ROC (China); Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan, ROC No. 1, Chang-Teh St., Taipei, Taiwan, ROC (China)

    2009-12-15

    As the use of leaded gasoline has ceased in the last decade, background lead exposure has generally been reduced. The aim of this study was to examine the effect of low-level lead exposure on human hearing loss. This study was conducted in a steel plant and 412 workers were recruited from all over the plant. Personal information such as demographics and work history was obtained through a questionnaire. All subjects took part in an audiometric examination of hearing thresholds, for both ears, with air-conducted pure tones at frequencies of 500, 1000, 2000, 3000, 4000, 6000 and 8000 Hz. Subjects' blood samples were collected and analyzed for levels of manganese, copper, zinc, arsenic, cadmium and lead with inductive couple plasma-mass spectrometry. Meanwhile, noise levels in different working zones were determined using a sound level meter with A-weighting network. Only subjects with hearing loss difference of no more than 15 dB between both ears and had no congenital abnormalities were included in further data analysis. Lead was the only metal in blood found significantly correlated with hearing loss for most tested sound frequencies (p < 0.05 to p < 0.0001). After adjustment for age and noise level, the logistic regression model analysis indicated that elevated blood lead over 7 {mu}g/dL was significantly associated with hearing loss at the sound frequencies of 3000 through 8000 Hz with odds ratios raging from 3.06 to 6.26 (p < 0.05 {approx} p < 0.005). We concluded that elevated blood lead at level below 10 {mu}g/dL might enhance the noise-induced hearing loss. Future research needs to further explore the detailed mechanism.

  7. Crossmodal plasticity in auditory, visual and multisensory cortical areas following noise-induced hearing loss in adulthood.

    Science.gov (United States)

    Schormans, Ashley L; Typlt, Marei; Allman, Brian L

    2017-01-01

    Complete or partial hearing loss results in an increased responsiveness of neurons in the core auditory cortex of numerous species to visual and/or tactile stimuli (i.e., crossmodal plasticity). At present, however, it remains uncertain how adult-onset partial hearing loss affects higher-order cortical areas that normally integrate audiovisual information. To that end, extracellular electrophysiological recordings were performed under anesthesia in noise-exposed rats two weeks post-exposure (0.8-20 kHz at 120 dB SPL for 2 h) and age-matched controls to characterize the nature and extent of crossmodal plasticity in the dorsal auditory cortex (AuD), an area outside of the auditory core, as well as in the neighboring lateral extrastriate visual cortex (V2L), an area known to contribute to audiovisual processing. Computer-generated auditory (noise burst), visual (light flash) and combined audiovisual stimuli were delivered, and the associated spiking activity was used to determine the response profile of each neuron sampled (i.e., unisensory, subthreshold multisensory or bimodal). In both the AuD cortex and the multisensory zone of the V2L cortex, the maximum firing rates were unchanged following noise exposure, and there was a relative increase in the proportion of neurons responsive to visual stimuli, with a concomitant decrease in the number of neurons that were solely responsive to auditory stimuli despite adjusting the sound intensity to account for each rat's hearing threshold. These neighboring cortical areas differed, however, in how noise-induced hearing loss affected audiovisual processing; the total proportion of multisensory neurons significantly decreased in the V2L cortex (control 38.8 ± 3.3% vs. noise-exposed 27.1 ± 3.4%), and dramatically increased in the AuD cortex (control 23.9 ± 3.3% vs. noise-exposed 49.8 ± 6.1%). Thus, following noise exposure, the cortical area showing the greatest relative degree of multisensory convergence

  8. Effect of cigarette smoking on noise-induced hearing loss in workers exposed to occupational noise in China.

    Science.gov (United States)

    Tao, Liyuan; Davis, Robert; Heyer, Nicholas; Yang, Qiuling; Qiu, Wei; Zhu, Liangliang; Li, Nan; Zhang, Hua; Zeng, Lin; Zhao, Yiming

    2013-01-01

    Excessive exposure to high noise level environments has the potential to cause noise-induced hearing loss (NIHL), and cigarette smoking has also been shown to have a potential adverse effect on hearing. The aim of this study was to determine whether smoking interacts with noise in the development of hearing loss, and if so, the extent of the contribution from smoking on NIHL. A cross-sectional study was designed to assess the effect of smoking on NIHL in 517 male workers (non-smokers: N = 199; smokers: N = 318) exposed to a high-level industrial noise environment in China. Shift-long temporal waveforms of the noise that workers were exposed to for evaluation of noise exposures, and audiometric threshold measures were obtained on all selected subjects. The subjects used hearing protection devices only within the last 1-2 years. The results suggest that smoking has an adverse effect on NIHL in workers exposed to high level industrial noise, i.e., the median high frequency hearing thresholds were significantly greater in smokers than non-smokers exposed to noise for more than 10 years. This effect was observed at 4.0 and 6.0 kHz. Smoking did not have an adverse effect on NIHL in workers exposed to noise less than 10 years. Multivariate regression analysis revealed that the odds ratio (OR) for high frequency hearing loss (i.e., hearing threshold greater than 40 dB at 4.0 kHz) were 1.94 for smokers in comparison to non-smokers. The results suggest that: (1) smokers have a higher risk of developing high frequency hearing loss than non-smokers with a similar occupational noise exposure, and (2) the interaction between cigarette smoking and high-level noise exposure may be additive. There is a need to develop and analyze a larger database of workers with well-documented exposures and smoking histories for better understanding of the effect of smoking on NIHL incurred from high-level industrial noise exposures. A better understanding of the role of smoking may lead to its

  9. Analysis of plasma microRNA expression profiles in male textile workers with noise-induced hearing loss.

    Science.gov (United States)

    Ding, Lu; Liu, Jing; Shen, Huan-Xi; Pan, Li-Ping; Liu, Qing-Dong; Zhang, Heng-Dong; Han, Lei; Shuai, Li-Guo; Ding, En-Min; Zhao, Qiu-Ni; Wang, Bo-Shen; Zhu, Bao-Li

    2016-03-01

    Circulating microRNAs (miRNAs) have attracted interests as non-invasive biomarkers of physiological and pathological conditions, which may be applied in noise-induced hearing loss (NIHL). However, no epidemiology studies have yet examined the potential effects of NIHL or noise exposure on miRNA expression profiles. We sought to identify permanent NIHL-related miRNAs and to predict the biological functions of the putative genes encoding the indicated miRNAs. In the discovery stage, we used a microarray assay to detect the miRNA expression profiles between pooled plasma samples from 10 noise-exposed individuals with normal hearing and 10 NIHL patients. In addition, we conducted a preliminary validation of six candidate miRNAs in the same 20 workers. Subsequently, three miRNAs were selected for expanded validation in 23 non-exposed individuals with normal hearing and 46 noise-exposed textile workers which including 23 noise-exposed workers with normal hearing and 23 NIHL patients. Moreover, we predicted the biological functions of the putative target genes using a Gene Ontology (GO) function enrichment analysis. In the discovery stage, compared with the noise exposures with normal hearing, 73 miRNAs demonstrated at least a 1.5-fold differential expression in the NIHL patients. In the preliminary validation, compared with the noise exposures, the plasma levels of miR-16-5p, miR-24-3p, miR-185-5p and miR-451a were all upregulated (P < 0.001) in the NIHL patients. In the expanded validation stage, compared with the non-exposures, the plasma levels of miR-24, miR-185-5p and miR-451a were all significantly downregulated (P < 0.001) in the exposures. And compared with the noise exposures, the plasma levels of miR-185-5p and miR-451a were slightly elevated (P < 0.001) in the NIHL patients, which were consistent with the results of preliminary validation and microarray analysis. The two indicated plasma miRNAs may be biomarkers of indicating responses to noise exposure

  10. Noise-Induced Hearing Loss in Relation With Vibration Disease and Exposure to Vibration Among Employees in Latvia

    Directory of Open Access Journals (Sweden)

    Kristina Karganova

    2016-05-01

    Full Text Available Occupational noise-induced hearing loss (ONIHL is a form of sensorineural hearing loss that is caused by intensive and continuous exposure to noise. It is one of the most frequently encountered occupational diseases worldwide despite numerous available control measures. ONIHL is a preventable disease, however, once the damage to the inner ear structures has occurred no medical intervention can reverse it. Aim. The purpose of this study was to describe and analyse incidence of registered cases of ONIHL in relation to vibration disease and exposure to vibration among employees in Latvia between 2005 and 2014. Materials and methods. The data used in the study were acquired from the Latvian State Register of Patients with Occupational Diseases and afterwards analyzed with applicable statistical tests using both Excel and IBM SPSS programmes to compare epidemiological parameters between ONIHL, vibration disease (VD and exposure to vibration and to identify the association between them. Results. In total data were obtained about 2302 patients with 2562 cases of occupational ear, nose and throat (ENT diseases. Out of them ONIHL was registered in 1699 cases (819 cases were ONIHL in combination with VD. Most of the employees with ONIHL and ONIHL simultaneously with VD were males aged 55-64. There was found statistically significant association between ONIHL and VD (p<0.001; Cramer’s V=0.42; OR=32.08; 95% confidence interval (95% CI 19.62–52.45. Statistically significant association was encountered between ONIHL and exposure to vibration as well (p<0.001; Cramer’s V=0.46; OR=10.97; 95% CI: 8.63–13.96. Conclusion. In total ONIHL was the most prevalent occupational ENT disease followed by chronic laryngitis, chronic pharyngitis and allergic rhinitis. Statistically significant association was found between ONIHL and VD, and ONIHL and exposure to vibration. Study revealed that hearing quality of workers employed in manufacturing; transport, storage

  11. PREVALENCE OF NOISE-INDUCED HEARING LOSS POLICE PERSONNEL COMING FOR HEALTH CHECKUP AT GOVERNMENT THENI MEDICAL COLLEGE AND HOSPITALS

    Directory of Open Access Journals (Sweden)

    Indra Thirugnanam

    2017-08-01

    Full Text Available BACKGROUND Occupational settings and transport is the prominent sources of noise that affect health. Noise-Induced Hearing Loss (NIHL is sensory neural hearing loss due to exposure to intense impulse or continuous sound. Exposure to noise can be occupational or non-occupational. The audiologic profile of NIHL is the presence of sensorineural hearing loss that is most pronounced in the high-frequency region between 3,000 Hz and 6,000 Hz of the audiogram and the greatest amount of hearing loss is typically around the 4,000-Hz region (i.e. 4,000 Hz dip.1 The main causes of hearing loss resulting in deafness in adults in India are excessive noise, age and ear infection. Although, occupational hearing loss is a well-recognized occupational condition arising from industries or occupations with exposure to high noise levels (e.g., airline crew,2 it has not been fully evaluated in occupations where the risk is not so overt such as the police force. Police officers are potentially exposed to multiple sources of noise including vehicle horns, gunfire, barking from police dog and traffic noise.3 The aim of the study is to study the incidence of noise-induced hearing loss amongst traffic police personnel who came for master health checkup. MATERIALS AND METHODS A total of 812 constables were examined. All individuals underwent a complete general, systemic and ENT examination to detect any obvious pathology, which may result in hearing loss. A detailed history was taken regarding the number of years of service in traffic branch, place of duty, past history of ear disease or intake of ototoxic drugs. Subjects suffering from preexisting ear disease such as CSO, OME, otosclerosis and suffering from URI has been excluded. Policemen suffering from hypertension and diabetes were also excluded. Remaining 774 was included in the study. This study was approved by the institutional ethical committee, Government Theni Medical College. Written consent was obtained from

  12. Stress

    Science.gov (United States)

    ... taking care of an aging parent. With mental stress, the body pumps out hormones to no avail. Neither fighting ... with type 1 diabetes. This difference makes sense. Stress blocks the body from releasing insulin in people with type 2 ...

  13. Safety and efficacy of ebselen for the prevention of noise-induced hearing loss: a randomised, double-blind, placebo-controlled, phase 2 trial.

    Science.gov (United States)

    Kil, Jonathan; Lobarinas, Edward; Spankovich, Christopher; Griffiths, Scott K; Antonelli, Patrick J; Lynch, Eric D; Le Prell, Colleen G

    2017-09-02

    Noise-induced hearing loss is a leading cause of occupational and recreational injury and disease, and a major determinant of age-related hearing loss. No therapeutic agent has been approved for the prevention or treatment of this disorder. In animal models, glutathione peroxidase 1 (GPx1) activity is reduced after acute noise exposure. Ebselen, a novel GPx1 mimic, has been shown to reduce both temporary and permanent noise-induced hearing loss in preclinical studies. We assessed the safety and efficacy of ebselen for the prevention of noise-induced hearing loss in young adults in a phase 2 clinical trial. In this single-centre, randomised, double-blind, placebo-controlled phase 2 trial, healthy adults aged 18-31 years were randomly assigned (1:1:1:1) at the University of Florida (Gainsville, FL, USA) to receive ebselen 200 mg, 400 mg, or 600 mg, or placebo orally twice daily for 4 days, beginning 2 days before a calibrated sound challenge (4 h of pre-recorded music delivered by insert earphones). Randomisation was done with an allocation sequence generated by an independent third party. The primary outcome was mean temporary threshold shift (TTS) at 4 kHz measured 15 min after the calibrated sound challenge by pure tone audiometry; a reduction of 50% in an ebselen dose group compared with the placebo group was judged to be clinically relevant. All participants who received the calibrated sound challenge and at least one dose of study drug were included in the efficacy analysis. All randomly assigned patients were included in the safety analysis. This trial is registered with ClinicalTrials.gov, number NCT01444846. Between Jan 11, 2013, and March 24, 2014, 83 participants were enrolled and randomly assigned to receive ebselen 200 mg (n=22), 400 mg (n=20), or 600 mg (n=21), or placebo (n=20). Two participants in the 200 mg ebselen group were discontinued from the study before the calibrated sound challenge because they no longer met the inclusion criteria; these

  14. Stress

    DEFF Research Database (Denmark)

    Keller, Hanne Dauer

    2015-01-01

    Kapitlet handler om stress som følelse, og det trækker primært på de få kvalitative undersøgelser, der er lavet af stressforløb.......Kapitlet handler om stress som følelse, og det trækker primært på de få kvalitative undersøgelser, der er lavet af stressforløb....

  15. Stress !!!

    OpenAIRE

    Fledderus, M.

    2012-01-01

    Twee op de vijf UT-studenten hebben last van ernstige studiestress, zo erg zelfs dat het ze in hun privéleven belemmert. Die cijfers komen overeen met het landelijk beeld van stress onder studenten. Samen met 14 andere universiteits- en hogeschoolbladen enquêteerde UT Nieuws bijna 5500 studenten. Opvallend is dat mannelijke studenten uit Twente zich veel minder druk lijken te maken over hun studie. Onder vrouwen ligt de stress juist erg hoog ten opzichte van het landelijk gemiddelde.

  16. [Study the impacts of diagnosis on occupational noise-induced deafness after bring into the different high frequency hearing threshold weighted value].

    Science.gov (United States)

    Xue, L J; Yang, A C; Chen, H; Huang, W X; Guo, J J; Liang, X Y; Chen, Z Q; Zheng, Q L

    2017-11-20

    Objective: Study of the results and the degree on occupational noise-induced deafness in-to the different high frequency hearing threshold weighted value, in order to provide theoretical basis for the re-vision of diagnostic criteria on occupational noise-induced deafness. Methods: A retrospective study was con-ducted to investigate the cases on the diagnosis of occupational noise-induced deafness in Guangdong province hospital for occupational disease prevention and treatment from January 2016 to January 2017. Based on the re-sults of the 3 hearing test for each test interval greater than 3 days in the hospital, the best threshold of each frequency was obtained, and based on the diagnostic criteria of occupational noise deafness in 2007 edition, Chi square test, t test and variance analysis were used to measure SPSS21.0 data, their differences are tested among the means of speech frequency and the high frequency weighted value into different age group, noise ex-posure group, and diagnostic classification between different dimensions. Results: 1. There were totally 168 cases in accordance with the study plan, male 154 cases, female 14 cases, the average age was 41.18 ±6.07 years old. 2. The diagnosis rate was increased into the weighted value of different high frequency than the mean value of pure speech frequency, the weighted 4 kHz frequency increased by 13.69% (χ(2)=9.880, P =0.002) , 6 kHz increased by 15.47% (χ(2)=9.985, P =0.002) and 4 kHz+6 kHz increased by15.47% (χ(2)=9.985, P =0.002) , the difference was statistically significant. The diagnostic rate of different high threshold had no obvious differ-ence between the genders. 3. The age groups were divided into less than or equal to 40years old group (A group) and 40-50 years old group (group B) , there were higher the diagnostic rate between high frequency weighted 4 kHz (A group χ(2)=3.380, P =0.050; B group χ(2)=4.054, P =0.032) , weighted 6 kHz (A group χ(2)=6.362, P =0.012; B group χ(2

  17. Antioxidant mediated response of Scoparia dulcis in noise-induced redox imbalance and immunohistochemical changes in rat brain.

    Science.gov (United States)

    Wankhar, Wankupar; Srinivasan, Sakthivel; Rajan, Ravindran; Sheeladevi, Rathinasamy

    2017-01-19

    Noise has been regarded as an environmental/occupational stressor that causes damages to both auditory and non-auditory organs. Prolonged exposure to these mediators of stress has often resulted in detrimental effect, where oxidative/nitrosative stress plays a major role. Hence, it would be appropriate to examine the possible role of free radicals in brain discrete regions and the "antioxidants" mediated response of S. dulcis. Animals were subjected to noise stress for 15 days (100 dB/4 hours/day) and estimation of endogenous free radical and antioxidant activity were carried out on brain discrete regions (the cerebral cortex, cerebellum, brainstem, striatum, hippocampus and hypothalamus). The result showed that exposure to noise could alleviate endogenous free radical generation and altered antioxidant status in brain discrete regions when compared to that of the control groups. This alleviated free radical generation (H 2 O 2 and NO) is well supported by an upregulated protein expression on immunohistochemistry of both iNOS and nNOS in the cerebral cortex on exposure to noise stress. These findings suggest that increased free radical generation and altered anti-oxidative status can cause redox imbalance in the brain discrete regions. However, free radical scavenging activity of the plant was evident as the noise exposed group treated with S. dulcis[200 mg/(kg·b·w)] displayed a therapeutic effect by decreasing the free radical level and regulate the anti-oxidative status to that of control animals. Hence, it can be concluded that the efficacy of S. dulcis could be attributed to its free radical scavenging activity and anti-oxidative property.

  18. Duration of works, flight hours, and blood pressure related to noise-induced hearing loss among Indonesian Air Force helicopter pilots

    Directory of Open Access Journals (Sweden)

    Kholidah Hanum

    2006-09-01

    Full Text Available Helicopter pilots exposed to high intensity noise and other risk factors had increased risk to be noise-induced hearing loss (NIHL. Therefore, it is beneficial to study several risk factors related to NIHL. This study was a nested case-control. Data was extracted from available medical records among helicopter pilots who performed routine aerophysiology training indoctrination (ILA during 1980 through March 2004 at Saryanto Institute for Aviation and Aerospace Medicine (Lakespra, Jakarta. Case was those who had audiogram with a notch of 40 dB or more and of 4000 Hertz on one site or bilateral ears. A case was matched by two controls who free from NIHL up to 2004. All risk factors for cases and controls were counted as of reference date of cases diagnosed. There were 187 medical records available for this study. A number of 32 cases and 64 controls were identified. The final model reveals that NIHL was related to total duration of works, flight hours, and blood pressure. Those who had 500 hours or more than less 500 hours had a moderate increased risk for 2.5 to be NIHL [Adjusted odds ratio (ORa= 2.50; 95% confidence intervals (CI = 0.66-9.29; p = 0.180]. Those who had total duration works 11-24 years had a moderate increased to be NIHL for 2.7 times (ORa = 2.71; 95% CI=0.90-8.10; p = 0.075. Furthermore, prehypertension and hypertension stage 1 subjects than normal blood pressure had moderate trend increased risk to be NIHL. In conclusion total flight hours for 500 hours or more, total duration works 11-24 years, or prehypertension and hypertension stage 1 increased risk NIHL. (Med J Indones 2006; 15:185-90 Keywords: noise induced hearing loss, flight hours, working duration, blood pressure

  19. Stress !!!

    NARCIS (Netherlands)

    Fledderus, M.

    2012-01-01

    Twee op de vijf UT-studenten hebben last van ernstige studiestress, zo erg zelfs dat het ze in hun privéleven belemmert. Die cijfers komen overeen met het landelijk beeld van stress onder studenten. Samen met 14 andere universiteits- en hogeschoolbladen enquêteerde UT Nieuws bijna 5500 studenten.

  20. Glucocorticoid metabolites in newborns: A marker for traffic noise related stress?

    DEFF Research Database (Denmark)

    Lech Cantuaria, Manuella; Usermann, Jakob; Proietti, Elena

    2018-01-01

    Traffic noise has been associated with an increased risk for several non-auditory health effects, which may be explained by a noise-induced release of stress hormones (e.g. glucocorticoids). Although several studies in children and adults have indicated an increased secretion of glucocorticoids...

  1. Low frequency noise case study : identification and mitigation of a severe infrasonic tone from a mine shaft ventilation fan

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, R.D. [HGC Engineering, Mississauga, ON (Canada)

    2007-07-01

    This paper presented a solution for a severe low frequency infrasound problem experienced at a home near a large mine shaft ventilation fan in Dallas, West Virginia. Strong low frequency acoustic pulsations were detected as far as 200 metres from the fan. HGC Engineering was retained by the coal mine company to investigate the source of the problem and to find solutions. Controlling low frequency sound is a challenge because the wavelengths of sound are long at low frequencies. The relatively high level of acoustic energy of a low frequency sound or infrasound that is loud enough to be heard also presents a problem for noise control. In order to be effective, low frequency noise control measures must usually be large, bulky and expensive. In this study, HGC Engineering readily identified acoustic pulsations in the order of 75 dB at 15 Hz outside the residences. At 15 Hz, the infrasound was not audible at the residence, but was causing rattling of lightweight furnishings inside the home. The measured sound pressure level at 15 Hz was approximately 10 dB greater than the onset of risk for rattling and perceptible vibration. The vibration was also perceptible on the walls and windows of the dwellings. The vibration of the dwelling structure had a high measured coherence with the air-borne pulsations at 15 Hz, suggesting that the vibration was induced by the air-borne infrasonic pulsations. HGC Engineering determined that 15 Hz corresponded to the rotational speed of the fan. A reduction of 15 dB at 15 Hz was targeted, in order to reduce the perceptibility and risk of rattling at the residence. A tuned acoustic plenum was considered to be a viable method to silence the fan. In order to investigate the effectiveness of this approach, HGC Engineering conducted a preliminary analytical design and parametric study of an acoustic plenum tuned to 15 Hz. An analytical model was developed to determine the acoustic behaviour of the plenum. In addition, a numerical boundary

  2. Stress.

    Science.gov (United States)

    Chambers, David W

    2008-01-01

    We all experience stress as a regular, and sometimes damaging and sometimes useful, part of our daily lives. In our normal ups and downs, we have our share of exhaustion, despondency, and outrage--matched with their corresponding positive moods. But burnout and workaholism are different. They are chronic, dysfunctional, self-reinforcing, life-shortening habits. Dentists, nurses, teachers, ministers, social workers, and entertainers are especially susceptible to burnout; not because they are hard-working professionals (they tend to be), but because they are caring perfectionists who share control for the success of what they do with others and perform under the scrutiny of their colleagues (they tend to). Workaholics are also trapped in self-sealing cycles, but the elements are ever-receding visions of control and using constant activity as a barrier against facing reality. This essay explores the symptoms, mechanisms, causes, and successful coping strategies for burnout and workaholism. It also takes a look at the general stress response on the physiological level and at some of the damage American society inflicts on itself.

  3. Perda auditiva induzida pelo ruído em trabalhadores de metalúrgica Noise induced hearing loss in metallurgical workers

    Directory of Open Access Journals (Sweden)

    Simone Adad Araújo

    Full Text Available Introdução: A perda auditiva induzida pelo ruído é uma patologia insidiosa cumulativa, que cresce ao longo dos anos de exposição ao ruído associado ao ambiente de trabalho. Objetivos: Identificar e quantificar a ocorrência de alterações auditivas sugestivas de Perda Auditiva Induzida pelo Ruído e os principais sintomas otorrinolaringológicos referidos pelos trabalhadores. Forma de estudo: prospectivo clínico randomizado. Casuística e métodos: Pesquisa realizada no período de janeiro a março de 2000 com 187 trabalhadores de indústria metalúrgica no município de Goiânia, avaliados por médicos otorrinolaringologistas através de roteiro de entrevista e audiometria ocupacional. Resultados: Foram obtidas audiometrias ocupacionais sendo: 21% sugestivas de PAIR, 72%, normais e 7%, sugestivas de outras doenças auditivas. Os sintomas auditivos mais freqüentes foram: dificuldade de compreensão da fala, 12%; hipoacusia, 7%; tinitus, 13%; sensação de plenitude auricular, 4%; otorreia, 6%; tonturas, 12%. Conclusão: Concluímos que em metalúrgica há ocorrência de alterações auditivas sugestivas de Perda Auditiva Induzida pelo Ruído e queixa de sintomas otorrinolaringológicos significativos.Introduction: Noise induced hearing loss is a cumulative pathological disease that increases over the years with exposure to noise associated with the work atmosphere. Objectives: To identify and quantify the occurrence of hearing loss suggestive of Noise Induced Hearing Loss (NIHL and the principle otolaryngological symptoms referred to by workers. Study design: prospective clinical randomized. Material and method: Research was carried out from January to March of 2000 with 187 metallurgical workers in the city of Goiânia, who were evaluated by otolaryngologists by means of a combination of interviews and occupational hearing exams. Results: Occupational hearing tests results were: 21% suggestive of NIHL, 72% normal, and 7% suggestive of

  4. Road and rail traffic noise induce comparable extra-aural effects as revealed during a short-term memory test

    Directory of Open Access Journals (Sweden)

    Eugen Gallasch

    2016-01-01

    Full Text Available To examine extraaural effects as induced by 20 min of road (ROAD and 20 min of rail (RAIL traffic noise with same loudness (75 dBA, a laboratory study was carried out. The study (N = 54 consisted of 28 high and 26 low-annoyed healthy individuals as determined by a traffic annoyance test. To control attention, all individuals performed a nonauditory short-term memory test during the noise exposures. A within-subject design, with phases of ROAD, RAIL, and CALM (memory test only, alternated by phases of rest, was defined. Heart rate (HR, systolic blood pressure (sBP, total peripheral resistance (TPR, as well as three autonomic variables, preejection period (PEP, 0.15–0.4 Hz high-frequency component of HR variability (HF, and salivary stress biomarker alpha amylase (sAA were measured. In relation to CALM, HR increased (RAIL +2.1%, ROAD +2.5%, sBP tended to increase against the end of noise exposure, PEP decreased (RAIL −0.7%, ROAD −0.8%, HF decreased (RAIL −3.4%, ROAD −2.9%, and sAA increased (RAIL +78%, ROAD +69%. No differences were found between RAIL and ROAD, indicating that both noise stressors induced comparable extraaural effects. Factor annoyance showed significant during CALM. Here a reduced sympathetic drive (higher PEP values combined with an increased vascular tone (higher TPR values was found at the high-annoyed subgroup.

  5. Mesopause temperature perturbations caused by infrasonic waves as a potential indicator for the detection of tsunamis and other geo-hazards

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    M. Bittner

    2010-07-01

    Full Text Available Many geo-hazards such as earthquakes, tsunamis, volcanic eruptions, severe weather, etc., produce acoustic waves with sub-audible frequency, so called infrasound. This sound propagates from the surface to the middle and upper atmosphere causing pressure and temperature perturbations. Temperature fluctuations connected with the above mentioned events usually are very weak at the surface, but the amplitude increases with height because of the exponential decrease of atmospheric pressure with increasing altitude. At the mesopause region (80–100 km height signal amplitudes are about two to three orders of magnitude larger than on the ground.

    The GRIPS (GRound-based Infrared P-branch Spectrometer measurement system operated by the German Remote Sensing Data Center of the German Aerospace Center (DLR-DFD derives temperatures of the mesopause region by observing hydroxyl (OH airglow emissions in the near infrared atmospheric emission spectrum originating from a thin layer at approximately 87 km height.

    The GRIPS instrument is in principle suited for the detection of infrasonic signals generated by e.g. tsunamis and other geo-hazards. This is due to the fact that the infrasound caused by such events should induce observable short-period fluctuations in the OH airglow temperatures. First results obtained during a field campaign performed at the Environmental Research Station "Schneefernerhaus", Zugspitze (47.4° N, 11.0° E from October to December 2008 are presented regarding potential sources of meteorological and orographical origin.

    An adequate distinction of the overlapping infrasonic signatures caused by different infrasound sources in the OH temperature record is needed for the ascription to the proper source. The approach presented here could form a contribution to a hazard monitoring and early warning system.

  6. Protective effect of unilateral and bilateral ear plugs on noise-induced hearing loss: Functional and morphological evaluation in animal model

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    Dong-Kee Kim

    2014-01-01

    Full Text Available The aim of the following study is to evaluate immediate protective effect of ear plug from noise morphologically and functionally. An 1-month aged 29 male C57BL/6 mice. Subjects were divided into four groups as normal control(G1, bilaterally plugged group (G2, unilaterally plugged group (G3 and noise control group (G4 and later 3 groups were exposed to 110 sound pressure level white noise for 60 min. Immediately after noise exposure, audiologic tests were performed and cochlear morphology and expression levels of a-synuclein in the cochlea were investigated. There were no functional changes in G2 and plugged ears of G3 after noise exposure, whereas unplugged ears of G3 and G4 showed significant hearing loss. In morphological study, there were a significant degeneration of the organ of Corti and mean number and diameter of efferent buttons, in unplugged ears of G3 and G4. Plugged ears of G3 also showed mild changes in morphological study. Reduction of a-synuclein was observed at the efferent terminals or cochlear extracts after noise exposure. The protective effect of ear plug on noise exposure was proven morphologically and functionally in the animal model of noise-induced hearing loss. Further study on cellular or ultrastructural level with ear plug will be needed to reveal more precise mechanism.

  7. Prevention of the Evolution of Workers' Hearing Loss from Noise-Induced Hearing Loss in Noisy Environments through a Hearing Conservation Program.

    Science.gov (United States)

    Fonseca, Vinicius Ribas; Marques, Jair; Panegalli, Flavio; Gonçalves, Claudia Giglio de Oliveira; Souza, Wesley

    2016-01-01

    Introduction Noise-induced hearing loss (NIHL) is a serious problem for workers and therefore for businesses. The hearing conservation program (HCP) is a set of coordinated measures to prevent the development or evolution of occupational hearing loss, which involves a continuous and dynamic process of implementation of hearing conservation routines through anticipation, recognition, evaluation, and subsequent control of the occurrence of existing environmental risks or of those that may exist in the workplace and lead to workers' hearing damage. Objective The aim of this study was to evaluate the effectiveness of the HCP in preventing further hearing loss in workers with audiograms suggestive of NIHL. The audiometric tests and medical records of 28 furniture company workers exposed to noise were reviewed and monitored for 2 years. Methods This retrospective, cross-sectional study examined five audiometric tests in the medical records (on admission and every semester) of 28 workers in a furniture company (totaling 140 audiometric exams) following the introduction of the HCP. Results Data analysis showed no differences between the audiometric tests conducted on admission and those performed every semester. Conclusions The HCP implemented was effective in preventing the worsening of hearing loss in workers already with NIHL when exposed to occupational noise. Therefore, such a measure could be useful for the employment of workers with hearing loss in job sectors that have noise exposure.

  8. Analysis of audiometric notch as a noise-induced hearing loss phenotype in US youth: data from the National Health And Nutrition Examination Survey, 2005-2010.

    Science.gov (United States)

    Bhatt, Ishan S; Guthrie, O'neil

    2017-06-01

    Bilateral audiometric notch (BN) at 4000-6000 Hz was identified as a noise-induced hearing loss (NIHL) phenotype for genetic association analysis in college-aged musicians. This study analysed BN in a sample of US youth. Prevalence of the BN within the study sample was determined and logistic-regression analyses were performed to identify audiologic and other demographic factors associated with BN. Computer-simulated "flat" audiograms were used to estimate potential influence of false-positive rates in estimating the prevalence of the BN. 2348 participants (12-19 years) following the inclusion criteria were selected from the National Health and Nutrition Examination Survey data (2005-2010). The prevalence of BN was 16.6%. Almost 55.6% of the participants showed notch in at least one ear. Noise exposure, gender, ethnicity and age showed significant relationship with the BN. Computer simulation revealed that 5.5% of simulated participants with "flat" audiograms showed BN. Association of noise exposure with BN suggests that it is a useful NIHL phenotype for genetic association analyses. However, further research is necessary to reduce false-positive rates in notch identification.

  9. Self-assessment of hearing status and risk of noise-induced hearing loss in workers in a rolling stock plant.

    Science.gov (United States)

    Pawlaczyk-Łuszczyńska, Małgorzata; Dudarewicz, Adam; Zamojska, Małgorzata; Sliwinska-Kowalska, Mariola

    2012-01-01

    Noise measurements and questionnaire inquiries were carried out for 124 workers of a rolling stock plant to develop a hearing conservation program. On the basis of that data, the risk of noise-induced hearing loss (NIHL) was evaluated. Additionally, the workers' hearing ability was assessed with the (modified) Amsterdam inventory for auditory disability and handicap, (m)AIADH. The workers had been exposed to noise at A-weighted daily noise exposure levels of 74-110 dB for 1-40 years. Almost one third of the workers complained of hearing impairment and the (m)AIADH results showed some hearing difficulties in over half of them. The estimated risk of hearing loss over 25 dB in the frequency range of 3-6 kHz was 41-50% when the standard method of predicting NIHL specified in Standard No. ISO 1999:1990 was used. This risk increased to 50-67% when noise impulsiveness, coexposure to organic solvents, elevated blood pressure and smoking were included in calculations.

  10. A functional Ser326Cys polymorphism in hOGG1 is associated with noise-induced hearing loss in a Chinese population.

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    Huanxi Shen

    Full Text Available DNA damage to cochlear hair cells caused by 8-oxoguanine (8-oxoG is essential for the development of noise-induced hearing loss (NIHL. Human 8-oxoG DNA glycosylase1 (hOGG1 is a key enzyme in the base excision repair (BER pathway that eliminates 8-oxoG. Many epidemiological and functional studies have suggested that the hOGG1 Ser326Cys polymorphism (rs1052133 is associated with many diseases. The purpose of this investigation was to investigate whether the hOGG1 Ser326Cys polymorphism in the human BER pathway is associated with genetic susceptibility to NIHL in a Chinese population. This polymorphism was genotyped among 612 workers with NIHL and 615 workers with normal hearing. We found that individuals with the hOGG1 Cys/Cys genotype had a statistically significantly increased risk of NIHL compared with those who carried the hOGG1 Ser/Ser genotype (adjusted OR=1.59, 95% CI=1.13-2.25 and this increased risk was more pronounced among the workers in the 15- to 25- and >25-year noise exposure time, 85-92 dB(A noise exposure level, ever smoking, and ever drinking groups, similar effects were also observed in a recessive model. In summary, our data suggested that the hOGG1 Cys/Cys genotype may be a genetic susceptibility marker for NIHL in the Chinese Han population.

  11. Noise-induced and age-related hearing loss:  new perspectives and potential therapies [version 1; referees: 4 approved

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    M Charles Liberman

    2017-06-01

    Full Text Available The classic view of sensorineural hearing loss has been that the primary damage targets are hair cells and that auditory nerve loss is typically secondary to hair cell degeneration. Recent work has challenged that view. In noise-induced hearing loss, exposures causing only reversible threshold shifts (and no hair cell loss nevertheless cause permanent loss of >50% of the synaptic connections between hair cells and the auditory nerve. Similarly, in age-related hearing loss, degeneration of cochlear synapses precedes both hair cell loss and threshold elevation. This primary neural degeneration has remained a “hidden hearing loss” for two reasons: 1 the neuronal cell bodies survive for years despite loss of synaptic connection with hair cells, and 2 the degeneration is selective for auditory nerve fibers with high thresholds. Although not required for threshold detection when quiet, these high-threshold fibers are critical for hearing in noisy environments. Research suggests that primary neural degeneration is an important contributor to the perceptual handicap in sensorineural hearing loss, and it may be key to the generation of tinnitus and other associated perceptual anomalies. In cases where the hair cells survive, neurotrophin therapies can elicit neurite outgrowth from surviving auditory neurons and re-establishment of their peripheral synapses; thus, treatments may be on the horizon.

  12. Prevention of the Evolution of Workers' Hearing Loss from Noise-Induced Hearing Loss in Noisy Environments through a Hearing Conservation Program

    Science.gov (United States)

    Fonseca, Vinicius Ribas; Marques, Jair; Panegalli, Flavio; Gonçalves, Claudia Giglio de Oliveira; Souza, Wesley

    2015-01-01

    Introduction Noise-induced hearing loss (NIHL) is a serious problem for workers and therefore for businesses. The hearing conservation program (HCP) is a set of coordinated measures to prevent the development or evolution of occupational hearing loss, which involves a continuous and dynamic process of implementation of hearing conservation routines through anticipation, recognition, evaluation, and subsequent control of the occurrence of existing environmental risks or of those that may exist in the workplace and lead to workers' hearing damage. Objective The aim of this study was to evaluate the effectiveness of the HCP in preventing further hearing loss in workers with audiograms suggestive of NIHL. The audiometric tests and medical records of 28 furniture company workers exposed to noise were reviewed and monitored for 2 years. Methods This retrospective, cross-sectional study examined five audiometric tests in the medical records (on admission and every semester) of 28 workers in a furniture company (totaling 140 audiometric exams) following the introduction of the HCP. Results Data analysis showed no differences between the audiometric tests conducted on admission and those performed every semester. Conclusions The HCP implemented was effective in preventing the worsening of hearing loss in workers already with NIHL when exposed to occupational noise. Therefore, such a measure could be useful for the employment of workers with hearing loss in job sectors that have noise exposure. PMID:26722345

  13. Infrasonic induced ground motions

    Science.gov (United States)

    Lin, Ting-Li

    On January 28, 2004, the CERI seismic network recorded seismic signals generated by an unknown source. Our conclusion is that the acoustic waves were initiated by an explosive source near the ground surface. The meteorological temperature and effective sound speed profiles suggested existence of an efficient near-surface waveguide that allowed the acoustic disturbance to propagate to large distances. An explosion occurring in an area of forest and farms would have limited the number of eyewitnesses. Resolution of the source might be possible by experiment or by detailed analysis of the ground motion data. A seismo-acoustic array was built to investigate thunder-induced ground motions. Two thunder events with similar N-wave waveforms but different horizontal slownesses are chosen to evaluate the credibility of using thunder as a seismic source. These impulsive acoustic waves excited P and S reverberations in the near surface that depend on both the incident wave horizontal slowness and the velocity structure in the upper 30 meters. Nineteen thunder events were chosen to further investigate the seismo-acoustic coupling. The consistent incident slowness differences between acoustic pressure and ground motions suggest that ground reverberations were first initiated somewhat away from the array. Acoustic and seismic signals were used to generate the time-domain transfer function through the deconvolution technique. Possible non-linear interaction for acoustic propagation into the soil at the surface was observed. The reverse radial initial motions suggest a low Poisson's ratio for the near-surface layer. The acoustic-to-seismic transfer functions show a consistent reverberation series of the Rayleigh wave type, which has a systematic dispersion relation to incident slownesses inferred from the seismic ground velocity. Air-coupled Rayleigh wave dispersion was used to quantitatively constrain the near-surface site structure with constraints afforded by near-surface body wave refraction and Rayleigh wave dispersion data. Theoretical standard high-frequency and air-coupled Rayleigh wave dispersion calculated by the inferred site structure match the observed dispersion curves. Our study suggests that natural or controlled air-borne pressure sources can be used to investigate the near-surface site structures for earthquake shaking hazard studies.

  14. Influence of risky and protective behaviors connected with listening to music on hearing loss and the noise induced threshold shift among students of the Medical University of Bialystok

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    Beata Modzelewska

    2017-03-01

    Full Text Available Background . Currently, significant changes have occurred in the character of sound exposure, along with the properties of the group affected by it. Thus, primary care physicians have to keep in mind that a sizable group of young adults comprises groups in which the prevalence of hearing loss is increasing. Objectives . The goal of the following study was to determine the auditory ability of the students attending the Medical University in Bialystok and to analyze their risky and protective behaviors relating to music consumption. Material and methods . In total, 230 students (age: 18–26 years completed a questionnaire about general personal information and their music-listening habits. Thereafter, pure tone audiometry at standard frequencies (0.25 kHz–8 kHz was performed. Results . Hearing loss was more frequent in subjects who listened to music at higher volumes (‘very loud’ – 22.2%, ‘loud’ – 3.9%, ‘not very loud’ – 2.1%, ‘quiet’ – 9.1%, p = 0.046. Hearing loss was more prevalent among those students who were living in a city with more than 50,000 inhabitants before starting higher education compared to the remaining subjects (7.95% vs. 0.97%, p = 0.025. Conclusions . The study demonstrated that surprisingly few medical students suffer from hearing loss or a noise induced threshold shift. There is no correlation between risky behavior such as a lengthy daily duration of listening to music or the type of headphone used and hearing loss. Hearing screening tests connected with education are indicated in the group of young adults due to the accumulative character of hearing damage.

  15. Genetic Variation in POU4F3 and GRHL2 Associated with Noise-Induced Hearing Loss in Chinese Population: A Case-Control Study

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    Xiangrong Xu

    2016-06-01

    Full Text Available Noise-induced hearing loss (NIHL is an important occupational disease worldwide resulting from interactions between genetic and environmental factors. The purpose of this study was to examine whether genetic variations in POU4F3 and GRHL2 may influence susceptibility to NIHL in the Chinese population. A matched case-control study was carried out among 293 hearing loss individuals and 293 normal hearing workers drawn from a population of 3790 noise-exposed workers. Ten single-nucleotide polymorphisms (SNPs in POU4F3 and GRHL2 were selected and genotyped. Logistic regression was performed to analyze the main effects of SNPs and the interactions between noise exposure and SNPs. Moreover, the interactions between predictor haplotypes and noise exposure were also analyzed. Analysis revealed that the CC genotype of rs1981361 in the GRHL2 gene was associated with a higher risk of NIHL (adjusted OR = 1.59; 95% CI: 1.08–2.32, p = 0.018. Additionally, the GG genotype of rs3735715 in the GRHL2 gene was also a risk genotype (adjusted OR = 1.48; 95% CI: 1.01–2.19, p = 0.046. Significant interactions were found between rs3735715, rs1981361 (GRHL2, rs1368402 as well as rs891969 (POU4F3 and noise exposure in the high-level exposure groups. Furthermore, the protective haplotype CA in the POU4F3 gene and the risk haplotype GCCG in the GRHL2 gene were identified combined with noise exposure. These results indicated that GRHL2 might be an NIHL susceptibility gene, but the effect of POU4F3 on NIHL could only be detected when taking noise exposure into account, and their effects were enhanced by higher levels of noise exposure. However, the differences were not significant after the Bonferroni correction was applied. These results should be seen as suggestive.

  16. Occupational noise exposure and noise-induced hearing loss are associated with work-related injuries leading to admission to hospital.

    Science.gov (United States)

    Girard, Serge-André; Leroux, Tony; Courteau, Marilene; Picard, Michel; Turcotte, Fernand; Richer, Olivier

    2015-04-01

    This study focuses on work-related injuries that required admission to hospital in a population of male workers exposed to occupational noise (≥80 dBA) which some displayed a hearing loss due to their exposure. The study population count 46 550 male workers, 1670 (3.6%) of whom incurred at least one work-related injury requiring admission to hospital within a period of 5 years following hearing tests conducted between 1987 and 2005. The noise exposure and hearing loss-related data were gathered during occupational noise-induced hearing loss (NIHL) screening. The hospital data were used to identify all members of the study population who were admitted, and the reason for admission. Finally, access to the death-related data made it possible to identify participants who died during the course of the study. Cox proportional hazards model taking into account hearing status, noise levels, age and cumulative duration of noise exposure at the time of the hearing test established the risk of work-related injuries leading to admission to hospital. For each dB of hearing loss, a statistically significant risk increase was observed (HR=1.01 dB 95% CI 1.006 to 1.01). An association (HR=2.36 95% CI 2.01 to 2.77) was also found between working in an occupational ambient noise ≥100 dBA and the risk of injury. From a safety perspective, this issue is highly relevant; especially when workers are exposed to intense ambient noise and NIHL. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  17. Trends in incidence of occupational asthma, contact dermatitis, noise-induced hearing loss, carpal tunnel syndrome and upper limb musculoskeletal disorders in European countries from 2000 to 2012.

    Science.gov (United States)

    Stocks, S Jill; McNamee, Roseanne; van der Molen, Henk F; Paris, Christophe; Urban, Pavel; Campo, Giuseppe; Sauni, Riitta; Martínez Jarreta, Begoña; Valenty, Madeleine; Godderis, Lode; Miedinger, David; Jacquetin, Pascal; Gravseth, Hans M; Bonneterre, Vincent; Telle-Lamberton, Maylis; Bensefa-Colas, Lynda; Faye, Serge; Mylle, Godewina; Wannag, Axel; Samant, Yogindra; Pal, Teake; Scholz-Odermatt, Stefan; Papale, Adriano; Schouteden, Martijn; Colosio, Claudio; Mattioli, Stefano; Agius, Raymond

    2015-04-01

    The European Union (EU) strategy for health and safety at work underlines the need to reduce the incidence of occupational diseases (OD), but European statistics to evaluate this common goal are scarce. We aim to estimate and compare changes in incidence over time for occupational asthma, contact dermatitis, noise-induced hearing loss (NIHL), carpal tunnel syndrome (CTS) and upper limb musculoskeletal disorders across 10 European countries. OD surveillance systems that potentially reflected nationally representative trends in incidence within Belgium, the Czech Republic, Finland, France, Italy, the Netherlands, Norway, Spain, Switzerland and the UK provided data. Case counts were analysed using a negative binomial regression model with year as the main covariate. Many systems collected data from networks of 'centres', requiring the use of a multilevel negative binomial model. Some models made allowance for changes in compensation or reporting rules. Reports of contact dermatitis and asthma, conditions with shorter time between exposure to causal substances and OD, were consistently declining with only a few exceptions. For OD with physical causal exposures there was more variation between countries. Reported NIHL was increasing in Belgium, Spain, Switzerland and the Netherlands and decreasing elsewhere. Trends in CTS and upper limb musculoskeletal disorders varied widely within and between countries. This is the first direct comparison of trends in OD within Europe and is consistent with a positive impact of European initiatives addressing exposures relevant to asthma and contact dermatitis. Taking a more flexible approach allowed comparisons of surveillance data between and within countries without harmonisation of data collection methods. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  18. Noise-Induced Hearing Loss

    Science.gov (United States)

    ... can have profound, negative effects on speech, language comprehension, communication, classroom learning, and social development. Studies indicate ... very loud sound, blast, or impulse, or from listening to loud sounds over an extended period. Preventing ...

  19. Effect of GRM7 polymorphisms on the development of noise-induced hearing loss in Chinese Han workers: a nested case-control study.

    Science.gov (United States)

    Yu, Peipei; Jiao, Jie; Chen, Guoshun; Zhou, Wenhui; Zhang, Huanling; Wu, Hui; Li, Yanhong; Gu, Guizhen; Zheng, Yuxin; Yu, Yue; Yu, Shanfa

    2018-01-05

    Noise-induced hearing loss (NIHL) is a complex, irreversible disease caused by the interaction of genetic and environmental factors. In recent years, a great many studies have been done to explore the NIHL susceptibility genes among humans. So far, high powerful detections have been founded that genes of potassium ion channel genes (KCNQ4 and KCNE1), catalase (CAT), protocadherin 15 (PCDH15), myosin 14 (MYH14) and heart shock protein (HSP70) which have been identified in more than one population may be associated with the susceptibility to NIHL. As for metabolic glutamate receptor7 gene (GRM7), a lot of researches mainly focus on age-related hearing loss (ARHL) and the results have shown that the polymorphisms of GRM7 are linked to the development of ARHL. However, little is known about the association of GRM7 and the susceptibility to NIHL. Therefore, the aim of this study was to explore the effect of GRM7 polymorphisms on the susceptibility to NIHL. A nested case-control study based on the cohort in a Chinese steel factory was implemented in 292 cases and 584 controls matched with the same sex, the age difference ≤ 5 years old, the same type of work, duration of occupational noise exposure ≤2 years. Five single nucleotide polymorphisms (SNPs) of GRM7 were gained through selecting and genotyping SNPs. Conditional logistic regression analysis was used to assess the main effect of GRM7 polymorphisms on the susceptibility to NIHL and the gene-by-environment interaction. Furthermore, the gene-by-gene interactions were analyzed by generalized multiple dimensionality reduction (GMDR). This research discovered for the first time that the mutant allele C in rs1485175 of the GMR7 may decrease individuals' susceptibility to NIHL. The interaction between rs1485175 and cumulative noise exposure (CNE) at high level was found after the stratification according to CNE (p/p bon  = 0.014/0.007, OR = 0.550, 95% CI: 0.340-0.891). Permutation test of GMDR suggested

  20. Multidirectional seismo-acoustic wavefield of strombolian explosions at Yasur, Vanuatu using a broadband seismo-acoustic network, infrasound arrays, and infrasonic sensors on tethered balloons

    Science.gov (United States)

    Matoza, R. S.; Jolly, A. D.; Fee, D.; Johnson, R.; Kilgour, G.; Christenson, B. W.; Garaebiti, E.; Iezzi, A. M.; Austin, A.; Kennedy, B.; Fitzgerald, R.; Key, N.

    2016-12-01

    Seismo-acoustic wavefields at volcanoes contain rich information on shallow magma transport and subaerial eruption processes. Acoustic wavefields from eruptions are predicted to be directional, but sampling this wavefield directivity is challenging because infrasound sensors are usually deployed on the ground surface. We attempt to overcome this observational limitation using a novel deployment of infrasound sensors on tethered balloons in tandem with a suite of dense ground-based seismo-acoustic, geochemical, and eruption imaging instrumentation. We present preliminary results from a field experiment at Yasur Volcano, Vanuatu from July 26th to August 4th 2016. Our observations include data from a temporary network of 11 broadband seismometers, 6 single infrasonic microphones, 7 small-aperture 3-element infrasound arrays, 2 infrasound sensor packages on tethered balloons, an FTIR, a FLIR, 2 scanning Flyspecs, and various visual imaging data. An introduction to the dataset and preliminary analysis of the 3D seismo-acoustic wavefield and source process will be presented. This unprecedented dataset should provide a unique window into processes operating in the shallow magma plumbing system and their relation to subaerial eruption dynamics.

  1. Ocorrência de perda auditiva induzida pelo ruído em carpinteiros Occurrence of noise induced hearing loss in carpenters

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    Victor Hygor Veríssimo Farias

    2012-06-01

    Full Text Available OBJETIVO: investigar a ocorrência de perda auditiva induzida pelo ruído (PAIR em carpinteiros, caracterizando a perda auditiva por faixa etária, tempo de exposição total ao ruído e uso regular de protetores auditivos durante o tempo total de exposição. MÉTODO: estudo retrospectivo, descritivo, em uma população de 80 carpinteiros da construção civil, atendidos em uma clínica particular. Foram analisados 60 trabalhadores, conforme dados obtidos na anamnese e ficha do exame audiométrico. RESULTADOS: 49% dos trabalhadores apresentaram audição normal, sendo 58% com limiares auditivos normais bilateralmente e 35% com entalhe audiométrico em 3 kHz, 4 kHz e/ou 6 kHz. 44% apresentaram perfil audiométrico sugestivo de PAIR, destes 74% foram classificados como PAIR bilateral e 19% como PAIR unilateral. Houve diferença estatística significante entre os grupo PAIR e Normal em relação às variáveis idade (p=0,001, assim como o tempo total de exposição ao ruído ocupacional (p=0,002. CONCLUSÃO: quanto maior a idade e o tempo de profissão como carpinteiro, maior é a sua alteração auditiva, principalmente, devido à exposição ao ruído elevado durante a jornada de trabalho, sendo também constatado que as medidas de controle pelo uso do protetor são insuficientes para prevenir perdas auditivas. Portanto, sugerem-se medidas preventivas em saúde auditiva ativamente nessa população estudada, no ramo da construção civil.PURPOSE: to investigate the occurrence of noise induced hearing loss in carpenters, characterizing the hearing loss for age group, time of total exposure to noise and regular use of hearing protectors during the total exposure time. METHOD: retrospective and descriptive study in a population of 80 construction carpenters, attended at a private clinic. 60 workers were analyzed, as data on medical history and record of audiometric testing. RESULTS: 49% of the workers shoed normal hearing, being 58% with normal

  2. Associação entre perda auditiva induzida pelo ruído e zumbidos Association between noise-induced hearing loss and tinnitus

    Directory of Open Access Journals (Sweden)

    Adriano Dias

    2006-01-01

    Full Text Available O estudo verificou a associação entre perda auditiva induzida por ruído (PAIR e queixa de zumbido em trabalhadores expostos ao ruído ocupacional. Foram entrevistados e avaliados trabalhadores com histórico de exposição ao ruído ocupacional atendidos em dois ambulatórios de audiologia. Estudou-se a existência de associação entre PAIR e ocorrência de zumbido por intermédio do ajuste de modelo de regressão logística, tendo como variável dependente o zumbido e como variável independente a PAIR, classificada em seis graus, controlada pelas co-variáveis idade e tempo de exposição ao ruído. Os dados foram coletados entre abril e outubro de 2003, na Cidade de Bauru, Estado de São Paulo, Brasil, contemplando 284 trabalhadores. Estimou-se que a prevalência de zumbido aumenta de acordo com a evolução do dano auditivo, controlado para a idade e tempo de exposição ao ruído. Os achados justificam o investimento em programas de conservação auditiva particularmente voltados para o controle da emissão de ruídos na fonte e para a intervenção na evolução das perdas auditivas geradas pela exposição ao ruído visando à manutenção da saúde auditiva e à diminuição dos sintomas associados.The objective of this study was to verify an association between noise-induced hearing loss (NIHL and tinnitus in workers exposed to occupational noise. Workers with a history of work noise exposure who attended two audiology outpatient clinics were interviewed and evaluated. The statistical association between NIHL and tinnitus was evaluated using an adjusted linear regression model, with tinnitus as the dependent variable and NIHL, classified into six levels, as the independent variable, with age and length of noise exposure as covariates. Data were collected from 284 workers between April and October, 2003, in Bauru, São Paulo State, Brazil. Tinnitus was observed to increase with the progression of auditory damage, controlled by age

  3. Association of Behavior With Noise-Induced Hearing Loss Among Attendees of an Outdoor Music Festival: A Secondary Analysis of a Randomized Clinical Trial.

    Science.gov (United States)

    Kraaijenga, Véronique J C; van Munster, J J C M; van Zanten, G A

    2018-06-01

    To date, factors associated with noise-induced hearing loss at music festivals have not yet been analyzed in a single comprehensive data set. In addition, little is known about the hearing loss-associated behavior of music festival attendees. To assess which factors are associated with the occurrence of a temporary threshold shift (TTS) after music exposure and to investigate the behavior of music festival attendees. This prospective post hoc analysis gathered data from a randomized, single-blind clinical trial conducted on September 5, 2015, at an outdoor music festival in Amsterdam, the Netherlands. Adult volunteers with normal hearing were recruited via social media from August 26 through September 3, 2015. Intention to use earplugs was an exclusion criterion. Of 86 volunteers assessed, 51 were included. This post hoc analysis was performed from October 3, 2016, through February 27, 2017. Music festival visit for 4.5 hours. The primary outcome was a TTS on a standard audiogram for the frequencies 3.0- and 4.0-kHz. Multivariable linear regression was performed to determine which factors are associated with a TTS. A questionnaire on behavior, hearing, and tinnitus was distributed to the participants before and after the festival visit. A total of 51 participants were included (18 men [35%] and 33 women [65%]) with a mean (SD) age of 27 (6) years. Mean (SD) threshold change across 3.0 and 4.0 kHz was 5.4 (5.7) dB for the right ear and 4.0 (6.1) dB for the left ear. Earplug use (absolute difference in the left ear, -6.0 dB [95% CI, -8.7 to -3.2 dB]; in the right ear, -6.4 dB [95% CI, -8.8 to -4.1 dB]), quantity of alcohol use (absolute difference per unit in the left ear, 1.1 dB [95% CI, 0.5 to 1.7 dB]; in the right ear, 0.7 dB [95% CI, 0.1 to 1.4 dB]), drug use (absolute difference in the right ear, 6.0 dB [95% CI, 0.9 to 11.1 dB]), and male sex (absolute difference in the right ear, 4.1 dB [95% CI, 0.3 to 5.9 dB]) were independently associated with hearing loss

  4. Infrasonic attenuation in the upper mesosphere-lower thermosphere: a comparison between Navier-Stokes and Burnett predictions.

    Science.gov (United States)

    Akintunde, Akinjide; Petculescu, Andi

    2014-10-01

    This paper presents the results of a pilot study comparing the use of continuum and non-continuum fluid dynamics to predict infrasound attenuation in the rarefied lower thermosphere. The continuum approach is embodied by the Navier-Stokes equations, while the non-continuum method is implemented via the Burnett equations [Proc. London Math. Soc. 39, 385-430 (1935); 40, 382-435 (1936)]. In the Burnett framework, the coupling between stress tensor and heat flux affects the dispersion equation, leading to an attenuation coefficient smaller than its Navier-Stokes counterpart by amounts of order 0.1 dB/km at 0.1 Hz, 10 dB/km at 1 Hz, and 100 dB/km at 10 Hz. It has been observed that many measured thermospheric arrivals are stronger than current predictions based on continuum mechanics. In this context, the consistently smaller Burnett-based absorption is cautiously encouraging.

  5. Role of Scoparia dulcis linn on noise-induced nitric oxide synthase (NOS) expression and neurotransmitter assessment on motor function in Wistar albino rats.

    Science.gov (United States)

    Wankhar, Wankupar; Srinivasan, Sakthivel; Sundareswaran, Loganathan; Wankhar, Dapkupar; Rajan, Ravindran; Sheeladevi, Rathinasamy

    2017-02-01

    Noise pollution is one of the most widespread and fast growing environmental and occupational menaces in the modern era. Exposure to noise above 100dB is not adaptable through the brain homeostatic mechanism. Yet, the detrimental effects of noise have often been ignored. Developing reliable animal models to understand the neurobiology of noise stress and advance our research in the field of medicine to impede this growing stressor is needed. In this study experimental animals were divided into four groups, (i) Control and (ii) S. dulcis extract (200mg/kgbw) treated control group. (iii) To mimic the influence of noise, animals in this group were exposed to noise stress (100dB/4h/day) for 15days and finally, (iv) Noise exposed treated with S. dulcis extract (200mg/kgbw) group. Rota-rod and narrow beam performance results showed impaired motor co-ordination in noise exposed group on both 1st and 15th day when compared to controls. This impaired motor function on exposure to noise could be attributed to the altered norepinephrine, dopamine and serotonin levels in both the striatum and cerebellum. Moreover, the motor impaired associated changes could also be attributed to upregulated nNOS and iNOS protein expression in the cerebellum resulting in increased nitric oxide radical production. This increased reactive free radicals species can initiate lipid peroxidation mediated changes in the cerebellar Purkinje cells, which is responsible for initiating inhibitory motor response and ultimately leading to impaired motor co-ordination. Treatment with S. dulcis extract (200mg/kgbw) could control motor impairment and regulate neurotransmitter level as that of control groups when compared to noise exposed group. One key aspect of therapeutic efficacy of the plant could have resulted due to attenuated lipid peroxidation mediated damages on the cerebellar Purkinje cells thereby regulating motor impairment. Thus, targeting the antioxidant and free radicals scavenging properties of

  6. Perda auditiva induzida por ruído e hipertensão em condutores de ônibus Noise-induced hearing loss and high blood pressure among city bus drivers

    Directory of Open Access Journals (Sweden)

    Heleno Rodrigues Corrêa Filho

    2002-12-01

    Full Text Available OBJETIVO: Estimar as prevalências de perda auditiva induzida por ruído e hipertensão arterial em condutores de ônibus urbanos. MÉTODOS: Executou-se estudo transversal em amostra probabilística de 108 motoristas da cidade de Campinas, SP. Aplicou-se questionário sobre história profissional, jornadas de trabalho e repouso, e realizou-se exame físico e laboratorial incluindo medida da pressão arterial, audiometria tonal limiar, logoaudiometria e dados antropométricos, após a obtenção de consentimento. RESULTADOS: A prevalência de perda auditiva induzida por ruído foi de 32,7% do total examinado. Segundo a classificação de Merluzzi, nos 31 casos classificados em primeiro e segundo graus, observou-se que a freqüência audiométrica com perda auditiva mais acentuada foi a de 6 kHz (61,3%, seguida pela de 4 kHz (38,7%, sem diferenças significantes quanto à lateralidade. A prevalência de hipertensão arterial diastólica (PAD³90 mmHG; PAS³140 mmHG foi de 13,2% dos examinados. CONCLUSÕES: O risco de disacusia induzida por ruído foi maior para os motoristas com mais de seis anos de trabalho, após ajuste para a perda relacionada com a idade, com um odds ratio de 19,25 (1,59OBJECTIVE: To estimate the prevalence of occupational noise-induced hearing loss and arterial hypertension among city bus drivers. METHODS: A cross-sectional study was carried out on a probability random sample of 108 city bus drivers taken out of a total of 1,529 estimated professionals in the city of Campinas, Brazil, in 1991. Drivers were interviewed using questionnaires on job history, shift work and vacation schedules and underwent clinical and laboratory examinations including measures of blood pressure, pure-tone audiometry, speech audiometry, and anthropometric data analysis after an informed consent was obtained. RESULTS: The prevalence of noise-induced hearing loss was 32.7%. According to Merluzzi's classification, 91.2% (31 cases were classified as

  7. Algorithmic-Reducibility = Renormalization-Group Fixed-Points; ``Noise''-Induced Phase-Transitions (NITs) to Accelerate Algorithmics (``NIT-Picking'') Replacing CRUTCHES!!!: Gauss Modular/Clock-Arithmetic Congruences = Signal X Noise PRODUCTS..

    Science.gov (United States)

    Siegel, J.; Siegel, Edward Carl-Ludwig

    2011-03-01

    Cook-Levin computational-"complexity"(C-C) algorithmic-equivalence reduction-theorem reducibility equivalence to renormalization-(semi)-group phase-transitions critical-phenomena statistical-physics universality-classes fixed-points, is exploited with Gauss modular/clock-arithmetic/model congruences = signal X noise PRODUCT reinterpretation. Siegel-Baez FUZZYICS=CATEGORYICS(SON of ``TRIZ''): Category-Semantics(C-S) tabular list-format truth-table matrix analytics predicts and implements "noise"-induced phase-transitions (NITs) to accelerate versus to decelerate Harel [Algorithmics(1987)]-Sipser[Intro. Theory Computation(1997) algorithmic C-C: "NIT-picking" to optimize optimization-problems optimally(OOPO). Versus iso-"noise" power-spectrum quantitative-only amplitude/magnitude-only variation stochastic-resonance, this "NIT-picking" is "noise" power-spectrum QUALitative-type variation via quantitative critical-exponents variation. Computer-"science" algorithmic C-C models: Turing-machine, finite-state-models/automata, are identified as early-days once-workable but NOW ONLY LIMITING CRUTCHES IMPEDING latter-days new-insights!!!

  8. Polymorphisms of heat shock protein 70 genes (HSPA1A, HSPA1B and HSPA1L and susceptibility of noise-induced hearing loss in a Chinese population: A case-control study.

    Directory of Open Access Journals (Sweden)

    Yanhong Li

    Full Text Available Noise-induced hearing loss (NIHL is the second-most frequent form of sensorineural hearing loss. When exposed to the same noise, some workers develop NIHL while others do not, suggesting that NIHL may be associated with genetic factors. To explore the relationship between single nucleotide polymorphisms (SNPs in heat shock protein 70 (HSP70 genes (HSPA1A, HSPA1B and HSPA1L and susceptibility to NIHL in Han Chinese workers exposed to noise, a case-control association study was carried out with 286 hearing loss cases and 286 matched with gender, age, type of work, and exposure time, drawn from a population of 3790 noise-exposed workers. Four SNPs were selected and genotyped. Subsequently, the effects of the alleles and genotypes of the three HSP70 genes (HSPA1A, HSPA1B and HSPA1L on NIHL were analyzed by using a conditional logistic regression. A generalized multiple dimensionality reduction (GMDR was applied to further detect an interaction between the four SNPs. Compared with the combined genotypes CC/TC, carriers of the TT genotype of rs2763979 appeared to show greater susceptibility to NIHL (P = 0.042, adjusted OR = 1.731, 95% CI 1.021-2.935. A significant interaction between rs2763979 and CNE was found (P = 0.029, and a significant association was found between TT of s2763979 and NIHL (P = 0.024, adjusted OR = 5.694, 95%CI 1.256-25.817 in the 96 dB (A≤CNE<101 dB (A group. The results suggest that the rs2763979 locus of the HSP70 genes may be associated with susceptibility to NIHL in Chinese individuals, and other HSP70 genes may also be susceptibility genes for NIHL, but the results must be further replicated in additional independent sample sets.

  9. Can intrinsic noise induce various resonant peaks?

    Energy Technology Data Exchange (ETDEWEB)

    Torres, J J; Marro, J; Mejias, J F, E-mail: jtorres@ugr.es [Institute Carlos I for Theoretical and Computational Physics and Departamento de Electromagnetismo y Fisica de la Materia, University of Granada, Granada (Spain)

    2011-05-15

    We theoretically describe how weak signals may be efficiently transmitted throughout more than one frequency range in noisy excitable media by a sort of stochastic multiresonance. This helps us to reinterpret recent experiments in neuroscience and to suggest that many other systems in nature might be able to exhibit several resonances. In fact, the observed behavior happens in our model as a result of competition between (i) changes in the transmitted signals as if the units were varying their activation threshold, and (ii) adaptive noise realized in the model as rapid activity-dependent fluctuations of the connection intensities. These two conditions are indeed known to characterize heterogeneously networked systems of excitable units, e.g. sets of neurons and synapses in the brain. Our results may find application also in the design of detector devices.

  10. Can intrinsic noise induce various resonant peaks?

    International Nuclear Information System (INIS)

    Torres, J J; Marro, J; Mejias, J F

    2011-01-01

    We theoretically describe how weak signals may be efficiently transmitted throughout more than one frequency range in noisy excitable media by a sort of stochastic multiresonance. This helps us to reinterpret recent experiments in neuroscience and to suggest that many other systems in nature might be able to exhibit several resonances. In fact, the observed behavior happens in our model as a result of competition between (i) changes in the transmitted signals as if the units were varying their activation threshold, and (ii) adaptive noise realized in the model as rapid activity-dependent fluctuations of the connection intensities. These two conditions are indeed known to characterize heterogeneously networked systems of excitable units, e.g. sets of neurons and synapses in the brain. Our results may find application also in the design of detector devices.

  11. Noise-induced effects in population dynamics

    Science.gov (United States)

    Spagnolo, Bernardo; Cirone, Markus; La Barbera, Antonino; de Pasquale, Ferdinando

    2002-03-01

    We investigate the role of noise in the nonlinear relaxation of two ecosystems described by generalized Lotka-Volterra equations in the presence of multiplicative noise. Specifically we study two cases: (i) an ecosystem with two interacting species in the presence of periodic driving; (ii) an ecosystem with a great number of interacting species with random interaction matrix. We analyse the interplay between noise and periodic modulation for case (i) and the role of the noise in the transient dynamics of the ecosystem in the presence of an absorbing barrier in case (ii). We find that the presence of noise is responsible for the generation of temporal oscillations and for the appearance of spatial patterns in the first case. In the other case we obtain the asymptotic behaviour of the time average of the ith population and discuss the effect of the noise on the probability distributions of the population and of the local field.

  12. Hearing: Noise-Induced Hearing Loss

    Science.gov (United States)

    ... reduce your exposure to noise by choosing quiet leisure activities rather than noisy ones. Develop the habit ... the degree of your hearing loss, you may benefit from using a hearing aid (a device you ...

  13. Stress Management: Job Stress

    Science.gov (United States)

    Healthy Lifestyle Stress management Job stress can be all-consuming — but it doesn't have to be. Address your triggers, keep perspective and ... stress triggers, it's often helpful to improve time management skills — especially if you tend to feel overwhelmed ...

  14. Childhood Stress

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Childhood Stress KidsHealth / For Parents / Childhood Stress What's in this ... and feel stress to some degree. Sources of Stress Stress is a function of the demands placed ...

  15. [Investigation into the relationship between mitochondrial 12 S rRNA gene, tRNA gene and cytochrome oxidase Ⅱ gene variations and the risk of noise-induced hearing loss].

    Science.gov (United States)

    Jiao, J; Gu, G Z; Chen, G S; Li, Y H; Zhang, H L; Yang, Q Y; Xu, X R; Zhou, W H; Wu, H; He, L H; Zheng, Y X; Yu, S F

    2017-01-06

    Objective: To explore the relationship between mitochondrial 12 S rRNA gene variation, tRNA gene variation and cytochrome oxidase Ⅱ gene point mutations and the risk of noise-induced hearing loss (NIHL). Methods: A nested case-control study was performed that followed a cohort of 7 445 noise-exposed workers in a steel factory in Henan province, China, from January 1, 2006 to December 31, 2015. Subjects whose average hearing threshold was more than 40 dB(A) in high frequency were defined as the case group, and subjects whose average hearing threshold was less than 35 dB(A) in high frequency and less than 25 dB (A) in speech frequency were defined as the control group. Subjects was recruited into the case group ( n =286) and the control group ( n= 286) according to gender, age, job category and time of exposure to noise, and a 1∶1 case-control study was carried out. We genotyped eight single nucleotide polymorphisms in the mitochondrial 12 S rRNA gene, the mitochondrial tRNA gene and the mitochondrial cytochrome oxidase Ⅱ gene using SNPscan high-throughput genotyping technology from the recruited subjects. The relationship between polymorphic sites and NIHL, adjusted for covariates, was analyzed using conditional logistic regression analysis, as were the subgroup data. Results: The average age of the recruited subjects was (40.3±8.1) years and the length of service exposure to noise was (18.6±8.9) years. The range of noise exposed levels and cumulative noise exposure (CNE) was 80.1- 93.4 dB (A) and 86.8- 107.9 dB (A) · year, respectively. For workers exposed to noise at a CNE level<98 dB (A) · year, smokers showed an increased risk of NIHL of 1.88 (1.16-3.05) compared with non-smokers; for workers exposed to noise at a CNE level ≥98 dB(A) · year, smokers showed an increased risk of NIHL of 2.53 (1.49- 4.30) compared with non-smokers. For workers exposed to noise at a CNE level<98 dB (A) · year, the results of univariate analysis and multifactor analysis

  16. Stress Management

    Science.gov (United States)

    Healthy Lifestyle Stress management By Mayo Clinic Staff Stress basics Stress is a normal psychological and physical reaction to the demands of life. ... some people's alarm systems rarely shut off. Stress management gives you a range of tools to reset ...

  17. Manage Stress

    Science.gov (United States)

    ... Manage Stress Print This Topic En español Manage Stress Browse Sections The Basics Overview Signs and Health ... and Health Effects What are the signs of stress? When people are under stress, they may feel: ...

  18. Stress Incontinence

    Science.gov (United States)

    Stress incontinence Overview Urinary incontinence is the unintentional loss of urine. Stress incontinence happens when physical movement or activity — such ... coughing, sneezing, running or heavy lifting — puts pressure (stress) on your bladder. Stress incontinence is not related ...

  19. Nuclear stress test

    Science.gov (United States)

    ... Persantine stress test; Thallium stress test; Stress test - nuclear; Adenosine stress test; Regadenoson stress test; CAD - nuclear stress; Coronary artery disease - nuclear stress; Angina - nuclear ...

  20. Occupational Stress

    OpenAIRE

    Löblová, Klára

    2011-01-01

    The thesis deals with load, stress and related questions of the working life. Work-related stress brings numerous difficulties not only to affected individuals, but as a result also to organizations. The thesis follows symptoms, impacts, somatic and mental aspects of stress, its types and also types of stressors, which cause this problem. It is concentrated on workload as a specific area of work-related stress, individual resistance to the load, factors of workload and work-related stress and...

  1. Seismic Methods of Infrasonic Signal Detection

    Science.gov (United States)

    1982-09-30

    Volcanol. & Geothermal Res., 6, pp. 139-164. Le Guern, F., Bernard, A., and Chevrier, R. M., (1980), Soufriere of Guadeloupe 1976-1977 eruption-mass...eruptions-V. Obser vations of plume dynamics during the 1979 Soufriere eruption, St. Vincent, Geophys. J. R. Astr. Soc., 69, pp. 551-570. -9b- TR 82-5...volcanic event, Bull. Volcanol., 27, pp. 5-24. Le Guern, F., Bernard, A., and Chevrier, R. M., (1980), Soufriere of Guadeloupe 1976-1977 eruption-mass

  2. Infrasonic backpulsed membrane cleaning of micro- and ...

    African Journals Online (AJOL)

    2011-08-29

    Aug 29, 2011 ... become prominent in water treatment for domestic and indus- trial water ... fouling and cleaning in a reverse osmosis (RO) system, and showed that the .... used to make yeast suspensions with concentrations of 1 g/ℓ. Alumina ...

  3. Explosive Infrasonic Events: Sensor Comparison Experiment (SCE)

    Energy Technology Data Exchange (ETDEWEB)

    Schnurr, J. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Garces, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Rodgers, A. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-02-06

    SCE (sensor comparison experiment) 1 through 4 consists of a series of four controlled above-ground explosions designed to provide new data for overpressure propagation. Infrasound data were collected by LLNL iPhones and other sensors. Origin times, locations HOB, and yields are not being released at this time and are therefore not included in this report. This preliminary report will be updated as access to additional data changes, or instrument responses are determined.

  4. Cold Stress

    Science.gov (United States)

    ... Publications and Products Programs Contact NIOSH NIOSH COLD STRESS Recommend on Facebook Tweet Share Compartir Workers who ... cold environments may be at risk of cold stress. Extreme cold weather is a dangerous situation that ...

  5. Heat Stress

    Science.gov (United States)

    ... Publications and Products Programs Contact NIOSH NIOSH HEAT STRESS Recommend on Facebook Tweet Share Compartir OSHA-NIOSH ... hot environments may be at risk of heat stress. Exposure to extreme heat can result in occupational ...

  6. Neuromuscular Stress.

    Science.gov (United States)

    White, Timothy P.; Kern, Marialice

    1994-01-01

    Discusses exercise-induced stress that results from motor unit recruitment, the impact of recruitment on selected systemic support systems, and some of the environmental overlays that affect the degree of physiological stress. Adaptations to sustained changes in physical activity and muscle and myotendinous injury induced by stress are examined.…

  7. Stress Fractures

    Science.gov (United States)

    Stress fractures Overview Stress fractures are tiny cracks in a bone. They're caused by repetitive force, often from overuse — such as repeatedly jumping up and down or running long distances. Stress fractures can also arise from normal use of ...

  8. Cook-Levin Theorem Algorithmic-Reducibility/Completeness = Wilson Renormalization-(Semi)-Group Fixed-Points; ``Noise''-Induced Phase-Transitions (NITs) to Accelerate Algorithmics (``NIT-Picking'') REPLACING CRUTCHES!!!: Models: Turing-machine, finite-state-models, finite-automata

    Science.gov (United States)

    Young, Frederic; Siegel, Edward

    Cook-Levin theorem theorem algorithmic computational-complexity(C-C) algorithmic-equivalence reducibility/completeness equivalence to renormalization-(semi)-group phase-transitions critical-phenomena statistical-physics universality-classes fixed-points, is exploited via Siegel FUZZYICS =CATEGORYICS = ANALOGYICS =PRAGMATYICS/CATEGORY-SEMANTICS ONTOLOGY COGNITION ANALYTICS-Aristotle ``square-of-opposition'' tabular list-format truth-table matrix analytics predicts and implements ''noise''-induced phase-transitions (NITs) to accelerate versus to decelerate Harel [Algorithmics (1987)]-Sipser[Intro.Thy. Computation(`97)] algorithmic C-C: ''NIT-picking''(!!!), to optimize optimization-problems optimally(OOPO). Versus iso-''noise'' power-spectrum quantitative-only amplitude/magnitude-only variation stochastic-resonance, ''NIT-picking'' is ''noise'' power-spectrum QUALitative-type variation via quantitative critical-exponents variation. Computer-''science''/SEANCE algorithmic C-C models: Turing-machine, finite-state-models, finite-automata,..., discrete-maths graph-theory equivalence to physics Feynman-diagrams are identified as early-days once-workable valid but limiting IMPEDING CRUTCHES(!!!), ONLY IMPEDE latter-days new-insights!!!

  9. Residual stresses

    International Nuclear Information System (INIS)

    Sahotra, I.M.

    2006-01-01

    The principal effect of unloading a material strained into the plastic range is to create a permanent set (plastic deformation), which if restricted somehow, gives rise to a system of self-balancing within the same member or reaction balanced by other members of the structure., known as residual stresses. These stresses stay there as locked-in stresses, in the body or a part of it in the absence of any external loading. Residual stresses are induced during hot-rolling and welding differential cooling, cold-forming and extruding: cold straightening and spot heating, fabrication and forced fitting of components constraining the structure to a particular geometry. The areas which cool more quickly develop residual compressive stresses, while the slower cooling areas develop residual tensile stresses, and a self-balancing or reaction balanced system of residual stresses is formed. The phenomenon of residual stresses is the most challenging in its application in surface modification techniques determining endurance mechanism against fracture and fatigue failures. This paper discusses the mechanism of residual stresses, that how the residual stresses are fanned and what their behavior is under the action of external forces. Such as in the case of a circular bar under limit torque, rectangular beam under limt moment, reclaiming of shafts welds and peening etc. (author)

  10. Oxidative stress

    Directory of Open Access Journals (Sweden)

    Osredkar Joško

    2012-05-01

    Full Text Available The human organism is exposed to the influence of various forms of stress, either physical, psychological or chemical, which all have in common that they may adversely affect our body. A certain amount of stress is always present and somehow directs, promotes or inhibits the functioning of the human body. Unfortunately, we are now too many and too often exposed to excessive stress, which certainly has adverse consequences. This is especially true for a particular type of stress, called oxidative stress. All aerobic organisms are exposed to this type of stress because they produce energy by using oxygen. For this type of stress you could say that it is rather imperceptibly involved in our lives, as it becomes apparent only at the outbreak of certain diseases. Today we are well aware of the adverse impact of radicals, whose surplus is the main cause of oxidative stress. However, the key problem remains the detection of oxidative stress, which would allow us to undertake timely action and prevent outbreak of many diseases of our time. There are many factors that promote oxidative stress, among them are certainly a fast lifestyle and environmental pollution. The increase in oxidative stress can also trigger intense physical activity that is directly associated with an increased oxygen consumption and the resulting formation of free radicals. Considering generally positive attitude to physical activity, this fact may seem at first glance contradictory, but the finding has been confimed by several studies in active athletes. Training of a top athlete daily demands great physical effort, which is also reflected in the oxidative state of the organism. However, it should be noted that the top athletes in comparison with normal individuals have a different defense system, which can counteract the negative effects of oxidative stress. Quite the opposite is true for irregular or excessive physical activity to which the body is not adapted.

  11. Work Stress

    OpenAIRE

    Roeters, Anne

    2014-01-01

    Most of us agree that stress is a growing problem within organizations. We hear about the postal workers who had killed fellow employees and supervisors, and then hear that a major cause of tension is at work. Friends tell us that they are stressed due to increased workload and he has to work overtime because the company is restructured. We read the polls that employees complain about the stress in trying to balance family life with the work. Stress is a dynamic condition in which an individu...

  12. Residual stresses

    International Nuclear Information System (INIS)

    Macherauch, E.

    1978-01-01

    Residual stresses are stresses which exist in a material without the influence of external powers and moments. They come into existence when the volume of a material constantly changes its form as a consequence of mechanical, thermal, and/or chemical processes and is hindered by neighbouring volumes. Bodies with residual stress are in mechanical balance. These residual stresses can be manifested by means of all mechanical interventions disturbing this balance. Acoustical, optical, radiological, and magnetical methods involving material changes caused by residual stress can also serve for determining residual stress. Residual stresses have an ambivalent character. In technical practice, they are feared and liked at the same time. They cause trouble because they can be the cause for unexpected behaviour of construction elements. They are feared since they can cause failure, in the worst case with catastrophical consequences. They are appreciated, on the other hand, because, in many cases, they can contribute to improvements of the material behaviour under certain circumstances. But they are especially liked for their giving convenient and (this is most important) mostly uncontrollable explanations. For only in very few cases we have enough knowledge and possibilities for the objective evaluation of residual stresses. (orig.) [de

  13. Geopotential Stress

    DEFF Research Database (Denmark)

    Schiffer, Christian; Nielsen, S.B.

    Density heterogeneity in the Earth’s lithosphere causes lateral pressure variations. Horizontal gradients of the vertically integrated lithostatic pressure, the Geopotential Energy (GPE), are a source of stresses (Geopotential Stress) that contribute to the Earth’s Stress Field. In theory the GPE...... is linearly related to the lithospheric part of the Geoid. The Geopotential Stress can be calculated if either the density structure and as a consequence the GPE or the lithospheric contribution to the Geoid is known. The lithospheric Geoid is usually obtained by short pass filtering of satellite Geoid...... are not entirely suitable for the stress calculations but can be compiled and adjusted. We present an approach in which a global lithospheric density model based on CRUST2.0 is obtained by simultaneously fitting topography and surface heat flow in the presence of isostatic compensation and long-wavelength lateral...

  14. Effect of Scoparia dulcis on noise stress induced adaptive immunity and cytokine response in immunized Wistar rats.

    Science.gov (United States)

    Sundareswaran, Loganathan; Srinivasan, Sakthivel; Wankhar, Wankupar; Sheeladevi, Rathinasamy

    Noise acts as a stressor and is reported to have impact on individual health depending on nature, type, intensity and perception. Modern medicine has no effective drugs or cure to prevent its consequences. Being an environmental stressor noise cannot be avoided; instead minimizing its exposure or consuming anti-stressor and adaptogens from plants can be considered. The present study was carried out to evaluate the anti-stressor, adaptogen and immunostimulatory activity of Scoparia dulcis against noise-induced stress in Wistar rat models. Noise stress in rats was created by broadband white noise generator, 100 dB A/4 h daily/15 days and S. dulcis (200 mg/kg b.w.) was administered orally. 8 groups of rats were used consisting of 6 animals each; 4 groups for unimmunized and 4 groups for immunized. For immunization, sheep red blood cells (5 × 10 9  cells/ml) were injected intraperitoneally. Sub-acute noise exposed rats showed a significant increase in corticosterone and IL-4 levels in both immunized and unimmunized rats whereas lymphocytes, antibody titration, soluble immune complex, IL-4 showed a marked increase with a significant decrease in IL-2, TNF-α, IFN-γ cytokines only in unimmunized rats. Immunized noise exposed rats presented increased leukocyte migration index and decreased foot pad thickness, IL-2, TNF-α, IFN-γ with no changes in the lymphocytes. S. dulcis (SD) has normalized and prevented the noise induced changes in cell-mediated and humoral immunity and it could be the presence of anti-stressor and immuno stimulant activity of the plant. Copyright © 2016 Transdisciplinary University, Bangalore and World Ayurveda Foundation. Published by Elsevier B.V. All rights reserved.

  15. Learn to manage stress

    Science.gov (United States)

    Stress - managing; Stress - recognizing; Stress - relaxation techniques ... LEARN TO RECOGNIZE STRESS The first step in managing stress is recognizing it in your life. Everyone feels stress in a different way. ...

  16. A Strategy for Understanding Noise-Induced Annoyance

    Science.gov (United States)

    1988-08-01

    Estimation by Sequential Testing (PEST) (Taylor and Creelman , 1967) can be used to efficiently establish the indifference point for each such pair of...population on applicability of noise rating procedures". Noise Control Engineering, 4, 65-70. Taylor, M. M. & Creelman , C. D. "PEST: Efficient

  17. Noise Induces Biased Estimation of the Correction Gain.

    Directory of Open Access Journals (Sweden)

    Jooeun Ahn

    Full Text Available The detection of an error in the motor output and the correction in the next movement are critical components of any form of motor learning. Accordingly, a variety of iterative learning models have assumed that a fraction of the error is adjusted in the next trial. This critical fraction, the correction gain, learning rate, or feedback gain, has been frequently estimated via least-square regression of the obtained data set. Such data contain not only the inevitable noise from motor execution, but also noise from measurement. It is generally assumed that this noise averages out with large data sets and does not affect the parameter estimation. This study demonstrates that this is not the case and that in the presence of noise the conventional estimate of the correction gain has a significant bias, even with the simplest model. Furthermore, this bias does not decrease with increasing length of the data set. This study reveals this limitation of current system identification methods and proposes a new method that overcomes this limitation. We derive an analytical form of the bias from a simple regression method (Yule-Walker and develop an improved identification method. This bias is discussed as one of other examples for how the dynamics of noise can introduce significant distortions in data analysis.

  18. Noise-induced stability in dryland plant ecosystems.

    Science.gov (United States)

    D'Odorico, Paolo; Laio, Francesco; Ridolfi, Luca

    2005-08-02

    Dryland plant ecosystems tend to exhibit bistable dynamics with two preferential configurations of bare and vegetated soils. Climate fluctuations are usually believed to act as a source of disturbance on these ecosystems and to reduce their stability and resilience. In contrast, this work shows that random interannual fluctuations of precipitation may lead to the emergence of an intermediate statistically stable condition between the two stable states of the deterministic dynamics of vegetation. As a result, there is an enhancement of ecosystem resilience and a decrease in the likelihood of catastrophic shifts to the desert state.

  19. Interventions to prevent occupational noise-induced hearing loss.

    Science.gov (United States)

    Tikka, Christina; Verbeek, Jos H; Kateman, Erik; Morata, Thais C; Dreschler, Wouter A; Ferrite, Silvia

    2017-07-07

    This is the second update of a Cochrane Review originally published in 2009. Millions of workers worldwide are exposed to noise levels that increase their risk of hearing disorders. There is uncertainty about the effectiveness of hearing loss prevention interventions. To assess the effectiveness of non-pharmaceutical interventions for preventing occupational noise exposure or occupational hearing loss compared to no intervention or alternative interventions. We searched the CENTRAL; PubMed; Embase; CINAHL; Web of Science; BIOSIS Previews; Cambridge Scientific Abstracts; and OSH UPDATE to 3 October 2016. We included randomised controlled trials (RCT), controlled before-after studies (CBA) and interrupted time-series (ITS) of non-clinical interventions under field conditions among workers to prevent or reduce noise exposure and hearing loss. We also collected uncontrolled case studies of engineering controls about the effect on noise exposure. Two authors independently assessed study eligibility and risk of bias and extracted data. We categorised interventions as engineering controls, administrative controls, personal hearing protection devices, and hearing surveillance. We included 29 studies. One study evaluated legislation to reduce noise exposure in a 12-year time-series analysis but there were no controlled studies on engineering controls for noise exposure. Eleven studies with 3725 participants evaluated effects of personal hearing protection devices and 17 studies with 84,028 participants evaluated effects of hearing loss prevention programmes (HLPPs). Effects on noise exposure Engineering interventions following legislationOne ITS study found that new legislation in the mining industry reduced the median personal noise exposure dose in underground coal mining by 27.7 percentage points (95% confidence interval (CI) -36.1 to -19.3 percentage points) immediately after the implementation of stricter legislation. This roughly translates to a 4.5 dB(A) decrease in noise level. The intervention was associated with a favourable but statistically non-significant downward trend in time of the noise dose of -2.1 percentage points per year (95% CI -4.9 to 0.7, 4 year follow-up, very low-quality evidence). Engineering intervention case studiesWe found 12 studies that described 107 uncontrolled case studies of immediate reductions in noise levels of machinery ranging from 11.1 to 19.7 dB(A) as a result of purchasing new equipment, segregating noise sources or installing panels or curtains around sources. However, the studies lacked long-term follow-up and dose measurements of workers, and we did not use these studies for our conclusions. Hearing protection devicesIn general hearing protection devices reduced noise exposure on average by about 20 dB(A) in one RCT and three CBAs (57 participants, low-quality evidence). Two RCTs showed that, with instructions for insertion, the attenuation of noise by earplugs was 8.59 dB better (95% CI 6.92 dB to 10.25 dB) compared to no instruction (2 RCTs, 140 participants, moderate-quality evidence). Administrative controls: information and noise exposure feedbackOn-site training sessions did not have an effect on personal noise-exposure levels compared to information only in one cluster-RCT after four months' follow-up (mean difference (MD) 0.14 dB; 95% CI -2.66 to 2.38). Another arm of the same study found that personal noise exposure information had no effect on noise levels (MD 0.30 dB(A), 95% CI -2.31 to 2.91) compared to no such information (176 participants, low-quality evidence). Effects on hearing loss Hearing protection devicesIn two studies the authors compared the effect of different devices on temporary threshold shifts at short-term follow-up but reported insufficient data for analysis. In two CBA studies the authors found no difference in hearing loss from noise exposure above 89 dB(A) between muffs and earplugs at long-term follow-up (OR 0.8, 95% CI 0.63 to 1.03 ), very low-quality evidence). Authors of another CBA study found that wearing hearing protection more often resulted in less hearing loss at very long-term follow-up (very low-quality evidence). Combination of interventions: hearing loss prevention programmesOne cluster-RCT found no difference in hearing loss at three- or 16-year follow-up between an intensive HLPP for agricultural students and audiometry only. One CBA study found no reduction of the rate of hearing loss (MD -0.82 dB per year (95% CI -1.86 to 0.22) for a HLPP that provided regular personal noise exposure information compared to a programme without this information.There was very-low-quality evidence in four very long-term studies, that better use of hearing protection devices as part of a HLPP decreased the risk of hearing loss compared to less well used hearing protection in HLPPs (OR 0.40, 95% CI 0.23 to 0.69). Other aspects of the HLPP such as training and education of workers or engineering controls did not show a similar effect.In three long-term CBA studies, workers in a HLPP had a statistically non-significant 1.8 dB (95% CI -0.6 to 4.2) greater hearing loss at 4 kHz than non-exposed workers and the confidence interval includes the 4.2 dB which is the level of hearing loss resulting from 5 years of exposure to 85 dB(A). In addition, of three other CBA studies that could not be included in the meta-analysis, two showed an increased risk of hearing loss in spite of the protection of a HLPP compared to non-exposed workers and one CBA did not. There is very low-quality evidence that implementation of stricter legislation can reduce noise levels in workplaces. Controlled studies of other engineering control interventions in the field have not been conducted. There is moderate-quality evidence that training of proper insertion of earplugs significantly reduces noise exposure at short-term follow-up but long-term follow-up is still needed.There is very low-quality evidence that the better use of hearing protection devices as part of HLPPs reduces the risk of hearing loss, whereas for other programme components of HLPPs we did not find such an effect. The absence of conclusive evidence should not be interpreted as evidence of lack of effectiveness. Rather, it means that further research is very likely to have an important impact.

  20. Contemporary noise-induced hearing loss (NIHL) prevention.

    Science.gov (United States)

    Sułkowski, Wiesław; Owczarek, Kalina; Olszewski, Jurek

    2017-08-31

    Hearing impairment caused by noise, traditionally called - depending on the duration of exposure - acute or chronic acoustic trauma, includes, in addition to presbyacusis, the most common adult population of hearing impaired. In Poland - according to the report of the Central Statistical Office (GUS, 2011), the number of workers employed in NDN exceeded the noise level (85 dB) is about 200 thousand, the highest in the mining, metal and metal products production, textiles and wood production. According to the Regulation of the Council of Ministers of on June 30, 2009, on the list of occupational diseases (Journal of Laws No. 132, item 1115), it is defined as "bilateral permanent hearing loss of the cochlear or sensory-nerve type, expressed as an increase in hearing threshold of at least 45 dB in the ear better heard, calculated as an arithmetic mean for frequencies 1,2 and 3 kHz. Hearing impairments also occur in the military and police during field training and in combat where the source of acoustic injuries are firearms and pulse-inducing explosions (as in some industries) with high C peak levels (Lc peak) Time to rise to a maximum of <1 ms. The prevalence of loud music listening, particularly by personal stereo players, is also affecting children and adolescents with audiometric hearing loss, according to the World Health Organization (WHO) estimates of around 15-20%. The preventive action strategy is defined by the European Union legislation and the national implementing legislation that reduces or eliminates the risk and reduces (if not eliminated), taking into account available technical and organizational solutions to minimize the risk of hearing damage. If you can not reduce the noise levels with technical and organizational methods, you need individual hearing protectors. Ear protectors may be equipped with electronic systems with active noise reduction (which can improve low and medium frequency performance), adjustable attenuation (improves speech intelligibility and perception of warning signals), and wireless communication for verbal communication.

  1. Moderators of noise-induced cognitive change in healthy adults

    OpenAIRE

    Wright, Bernice AL; Peters, Emmanuelle R; Ettinger, Ulrich; Kuipers, Elizabeth; Kumari, Veena

    2016-01-01

    Environmental noise causes cognitive impairment, particularly in executive function and episodic memory domains, in healthy populations. However, the possible moderating influences on this relationship are less clear. This study assessed 54 healthy participants (24 men) on a cognitive battery (measuring psychomotor speed, attention, executive function, working memory, and verbal learning and memory) under three (quiet, urban, and social) noise conditions. IQ, subjective noise sensitivity, sle...

  2. Signs of noise-induced neural degeneration in humans

    DEFF Research Database (Denmark)

    Holtegaard, Pernille; Olsen, Steen Østergaard

    2015-01-01

    of background noise, while leaving the processing of low-level stimuli unaffected. The purpose of this study was to investigate if signs of such primary neural damage from noise-exposure could also be found in noiseexposed human individuals. It was investigated: (1) if noise-exposed listeners with hearing......Animal studies demonstrated that noise exposure causes a primary and selective loss of auditory-nerve fibres with low spontaneous firing rate. This neuronal impairment, if also present in humans, can be assumed to affect the processing of supra-threshold stimuli, especially in the presence...... thresholds within the “normal” range perform poorer, in terms of their speech recognition threshold in noise (SRTN), and (2) if auditory brainstem responses (ABR) reveal lower amplitude of wave I in the noise-exposed listeners. A test group of noise/music-exposed individuals and a control group were...

  3. Towards a Molecular Understanding of Noise-Induced Hearing Loss

    Science.gov (United States)

    2016-10-01

    Department of Defense, Washington Headquarters Services , Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway...Distribution Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT The purpose of this project is to generate the cell type-specific molecular blueprint of changes in...in hair cells, support cells and whole inner ears, 6 and 24 hours after noise exposure; (c) Collected and processed most of the tissue for TTS

  4. Noise-induced temporal dynamics in Turing systems

    KAUST Repository

    Schumacher, Linus J.; Woolley, Thomas E.; Baker, Ruth E.

    2013-01-01

    We examine the ability of intrinsic noise to produce complex temporal dynamics in Turing pattern formation systems, with particular emphasis on the Schnakenberg kinetics. Using power spectral methods, we characterize the behavior of the system using

  5. A minimal model of burst-noise induced bistability.

    Directory of Open Access Journals (Sweden)

    Johannes Falk

    Full Text Available We investigate the influence of intrinsic noise on stable states of a one-dimensional dynamical system that shows in its deterministic version a saddle-node bifurcation between monostable and bistable behaviour. The system is a modified version of the Schlögl model, which is a chemical reaction system with only one type of molecule. The strength of the intrinsic noise is varied without changing the deterministic description by introducing bursts in the autocatalytic production step. We study the transitions between monostable and bistable behavior in this system by evaluating the number of maxima of the stationary probability distribution. We find that changing the size of bursts can destroy and even induce saddle-node bifurcations. This means that a bursty production of molecules can qualitatively change the dynamics of a chemical reaction system even when the deterministic description remains unchanged.

  6. Toward a Molecular Understanding of Noise-Induced Hearing Loss

    Science.gov (United States)

    2017-10-01

    information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this...reverse NIHL. As a first step towards designing targeted therapeutics, we suggested to generate mouse models which allow cell type-specific translatome...year IV of the project. Future plans:  Validation of select genes by in-situ hybridization and/or immunohistochemistry  Possible interrogation of

  7. Noise induced stabilization of chaotic free-running laser diode

    Energy Technology Data Exchange (ETDEWEB)

    Virte, Martin, E-mail: mvirte@b-phot.org [Brussels Photonics Team, Department of Applied Physics and Photonics, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel (Belgium)

    2016-05-15

    In this paper, we investigate theoretically the stabilization of a free-running vertical-cavity surface-emitting laser exhibiting polarization chaos dynamics. We report the existence of a boundary isolating the chaotic attractor on one side and a steady-state on the other side and identify the unstable periodic orbit playing the role of separatrix. In addition, we highlight a small range of parameters where the chaotic attractor passes through this boundary, and therefore where chaos only appears as a transient behaviour. Then, including the effect of spontaneous emission noise in the laser, we demonstrate that, for realistic levels of noise, the system is systematically pushed over the separating solution. As a result, we show that the chaotic dynamics cannot be sustained unless the steady-state on the other side of the separatrix becomes unstable. Finally, we link the stability of this steady-state to a small value of the birefringence in the laser cavity and discuss the significance of this result on future experimental work.

  8. Long-term memory stabilized by noise-induced rehearsal.

    Science.gov (United States)

    Wei, Yi; Koulakov, Alexei A

    2014-11-19

    Cortical networks can maintain memories for decades despite the short lifetime of synaptic strengths. Can a neural network store long-lasting memories in unstable synapses? Here, we study the effects of ongoing spike-timing-dependent plasticity (STDP) on the stability of memory patterns stored in synapses of an attractor neural network. We show that certain classes of STDP rules can stabilize all stored memory patterns despite a short lifetime of synapses. In our model, unstructured neural noise, after passing through the recurrent network connections, carries the imprint of all memory patterns in temporal correlations. STDP, combined with these correlations, leads to reinforcement of all stored patterns, even those that are never explicitly visited. Our findings may provide the functional reason for irregular spiking displayed by cortical neurons and justify models of system memory consolidation. Therefore, we propose that irregular neural activity is the feature that helps cortical networks maintain stable connections. Copyright © 2014 the authors 0270-6474/14/3415804-12$15.00/0.

  9. Controlling Mitochondrial Dynamics to Mitigate Noise-Induced Hearing Loss

    Science.gov (United States)

    2017-10-01

    Alfred L. Nuttall CONTRACTING ORGANIZATION: Oregon Health & Science University Portland, OR 97201 REPORT DATE: October 2017 TYPE OF REPORT: Annual...ohsu.edu 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER Oregon Health & Science...based upon the results of these studies, we have also examined additional concentrations of mdivi-1 and performed a multiple-day (5 days) mdivi-1

  10. Thermodynamics aspects of noise-induced phase synchronization

    Science.gov (United States)

    Pinto, Pedro D.; Oliveira, Fernando A.; Penna, André L. A.

    2016-05-01

    In this article, we present an approach for the thermodynamics of phase oscillators induced by an internal multiplicative noise. We analytically derive the free energy, entropy, internal energy, and specific heat. In this framework, the formulation of the first law of thermodynamics requires the definition of a synchronization field acting on the phase oscillators. By introducing the synchronization field, we have consistently obtained the susceptibility and analyzed its behavior. This allows us to characterize distinct phases in the system, which we have denoted as synchronized and parasynchronized phases, in analogy with magnetism. The system also shows a rich complex behavior, exhibiting ideal gas characteristics for low temperatures and susceptibility anomalies that are similar to those present in complex fluids such as water.

  11. Controlling noise-induced behavior of excitable networks

    International Nuclear Information System (INIS)

    Patidar, S; Pototsky, A; Janson, N B

    2009-01-01

    The paper demonstrates the possibility to control the collective behavior of a large network of excitable stochastic units, in which oscillations are induced merely by external random input. Each network element is represented by the FitzHugh-Nagumo system under the influence of noise, and the elements are coupled through the mean field. As known previously, the collective behavior of units in such a network can range from synchronous to non-synchronous spiking with a variety of states in between. We apply the Pyragas delayed feedback to the mean field of the network and demonstrate that this technique is capable of suppressing or weakening the collective synchrony, or of inducing the synchrony where it was absent. On the plane of control parameters we indicate the areas where suppression of synchrony is achieved. To explain the numerical observations on a qualitative level, we use the semi-analytic approach based on the cumulant expansion of the distribution density within Gaussian approximation. We perform bifurcation analysis of the obtained cumulant equations with delay and demonstrate that the regions of stability of its steady state have qualitatively the same structure as the regions of synchrony suppression of the original stochastic equations. We also demonstrate the delay-induced multistability in the stochastic network. These results are relevant to the control of unwanted behavior in neural networks.

  12. Thermodynamics aspects of noise-induced phase synchronization.

    Science.gov (United States)

    Pinto, Pedro D; Oliveira, Fernando A; Penna, André L A

    2016-05-01

    In this article, we present an approach for the thermodynamics of phase oscillators induced by an internal multiplicative noise. We analytically derive the free energy, entropy, internal energy, and specific heat. In this framework, the formulation of the first law of thermodynamics requires the definition of a synchronization field acting on the phase oscillators. By introducing the synchronization field, we have consistently obtained the susceptibility and analyzed its behavior. This allows us to characterize distinct phases in the system, which we have denoted as synchronized and parasynchronized phases, in analogy with magnetism. The system also shows a rich complex behavior, exhibiting ideal gas characteristics for low temperatures and susceptibility anomalies that are similar to those present in complex fluids such as water.

  13. Colored-noise-induced discontinuous transitions in symbiotic ecosystems

    Science.gov (United States)

    Mankin, Romi; Sauga, Ako; Ainsaar, Ain; Haljas, Astrid; Paunel, Kristiina

    2004-06-01

    A symbiotic ecosystem is studied by means of the Lotka-Volterra stochastic model, using the generalized Verhulst self-regulation. The effect of fluctuating environment on the carrying capacity of a population is taken into account as dichotomous noise. The study is a follow-up of our investigation of symbiotic ecosystems subjected to three-level (trichotomous) noise [R. Mankin, A. Ainsaar, A. Haljas, and E. Reiter, Phys. Rev. E 65, 051108 (2002)]. Relying on the mean-field theory, an exact self-consistency equation for stationary states is derived. In some cases the mean field exhibits hysteresis as a function of noise parameters. It is established that random interactions with the environment can cause discontinuous transitions. The dependence of the critical coupling strengths on the noise parameters is found and illustrated by phase diagrams. Predictions from the mean-field theory are compared with the results of numerical simulations. Our results provide a possible scenario for catastrophic shifts of population sizes observed in nature.

  14. Prevalence of noise-induced hearing loss in drivers

    Directory of Open Access Journals (Sweden)

    Andréa Cintra Lopes1, , , ,

    2012-01-01

    Full Text Available Introduction: Work-related hearing loss is one of the most common occupational illness progresses over the years of noise exposure associated with the work environment, may cause damage to undertake physical activity, the individual's physiological and mental besides causing hearing damage irreversible interfering with communication and quality of life. With high prevalence of male evaluates which is the second leading cause of hearing loss. Since there is no medical treatment for this type of hearing loss, it is evident the importance of preventive and conferences aimed at preserving hearing and health as a whole. Objective: To assess the prevalence of hearing loss in audiometry admission of drivers. Methods: Retrospective study. By 76 charts of professional drivers in leased transport companies. We analyzed data from specific interview and pure tone audiometry. Results: The prevalence of abnormal tests was 22.36% with the lowest thresholds for tritonal average of 3,000, 4,000 and 6,000 Hz. The higher the age, the higher thresholds. Conclusion: This study has highlighted the occurrence of hearing in the absence of complaints. Considering that PAIR is preventable, justifies the importance of coordinated and multidisciplinary involving not only health teams and safety, but also the institutions involved in preserving the health of workers, as the team SESMET, unions or prosecutors.

  15. Interventions to prevent occupational noise-induced hearing loss

    NARCIS (Netherlands)

    Verbeek, Jos H.; Kateman, Erik; Morata, Thais C.; Dreschler, Wouter A.; Mischke, Christina

    2012-01-01

    Background Millions of workers worldwide are exposed to noise levels that increase their risk of hearing impairment. Little is known about the effectiveness of hearing loss prevention interventions. Objectives To assess the effectiveness of non-pharmaceutical interventions for preventing

  16. Interventions to prevent occupational noise induced hearing loss

    NARCIS (Netherlands)

    Verbeek, Jos H.; Kateman, Erik; Morata, Thais C.; Dreschler, Wout; Sorgdrager, Bas

    2009-01-01

    BACKGROUND: Millions of workers worldwide are exposed to noise levels that increase their risk of hearing impairment. Little is known about the effectiveness of hearing loss prevention interventions. OBJECTIVES: To assess the effectiveness of non-pharmaceutical interventions for preventing

  17. Interventions to prevent occupational noise-induced hearing loss

    NARCIS (Netherlands)

    Tikka, Christina; Verbeek, Jos H.; Kateman, Erik; Morata, Thais C.; Dreschler, Wouter A.; Ferrite, Silvia

    2017-01-01

    This is the second update of a Cochrane Review originally published in 2009. Millions of workers worldwide are exposed to noise levels that increase their risk of hearing disorders. There is uncertainty about the effectiveness of hearing loss prevention interventions. To assess the effectiveness of

  18. Noise-Induced Hearing Impairment As An Occupational Risk Factor ...

    African Journals Online (AJOL)

    Noise pollution in workplaces poses serious health risks including that of cardiovascular disturbances and impairment of hearing. The objective of this study was to assess the effects of occupational noise on hearing among selected industrial workers in Benin City, Nigeria. Male and female workers (n=150) in sawmills, ...

  19. Noise-induced Min phenotypes in E. coli.

    Directory of Open Access Journals (Sweden)

    David Fange

    2006-06-01

    Full Text Available The spatiotemporal oscillations of the Escherichia coli proteins MinD and MinE direct cell division to the region between the chromosomes. Several quantitative models of the Min system have been suggested before, but no one of them accounts for the behavior of all documented mutant phenotypes. We analyzed the stochastic reaction-diffusion kinetics of the Min proteins for several E. coli mutants and compared the results to the corresponding deterministic mean-field description. We found that wild-type (wt and filamentous (ftsZ- cells are well characterized by the mean-field model, but that a stochastic model is necessary to account for several of the characteristics of the spherical (rodA- and phospathedylethanolamide-deficient (PE- phenotypes. For spherical cells, the mean-field model is bistable, and the system can get trapped in a non-oscillatory state. However, when the intrinsic noise is considered, only the experimentally observed oscillatory behavior remains. The stochastic model also reproduces the change in oscillation directions observed in the spherical phenotype and the occasional gliding of the MinD region along the inner membrane. For the PE- mutant, the stochastic model explains the appearance of randomly localized and dense MinD clusters as a nucleation phenomenon, in which the stochastic kinetics at low copy number causes local discharges of the high MinD(ATP to MinD(ADP potential. We find that a simple five-reaction model of the Min system can explain all documented Min phenotypes, if stochastic kinetics and three-dimensional diffusion are accounted for. Our results emphasize that local copy number fluctuation may result in phenotypic differences although the total number of molecules of the relevant species is high.

  20. Noise-induced temporal dynamics in Turing systems

    KAUST Repository

    Schumacher, Linus J.

    2013-04-25

    We examine the ability of intrinsic noise to produce complex temporal dynamics in Turing pattern formation systems, with particular emphasis on the Schnakenberg kinetics. Using power spectral methods, we characterize the behavior of the system using stochastic simulations at a wide range of points in parameter space and compare with analytical approximations. Specifically, we investigate whether polarity switching of stochastic patterns occurs at a defined frequency. We find that it can do so in individual realizations of a stochastic simulation, but that the frequency is not defined consistently across realizations in our samples of parameter space. Further, we examine the effect of noise on deterministically predicted traveling waves and find them increased in amplitude and decreased in speed. © 2013 American Physical Society.

  1. Entropic noises-induced resonance in a geometrically confined system

    International Nuclear Information System (INIS)

    Zeng, Chunhua; Gong, Ailing; Wang, Hua

    2012-01-01

    We consider the motion of Brownian particles through a narrow tube of varying cross-section in a geometrically confined system subjected to a sinusoidal oscillating force. The varying cross-section of the confinement results in an effective purely entropic potential in reduced dimension. Besides an additive Langevin force, one external additive and another multiplicative noise are acting along the x-direction. We demonstrate that the presence of a periodic input may give rise to a maximum and a minimum of the spectral amplification at corresponding optimal values of the noise strength, and therefore to the appearance of the purely entropic stochastic resonance and reverse-resonance phenomena. Furthermore, we show that the cross-correlation between two noises leads to a decrease of the spectral amplification, i.e., we observe the cross-correlation between two noises weakening the resonance. Mechanisms for the cross-correlation weakening the resonance are explained from the point of view of the effective purely entropic potential. (paper)

  2. Use of Otoacoustic emissions in noise induced hearing loss prevention

    CSIR Research Space (South Africa)

    Edwards, A

    2010-10-01

    Full Text Available in laboratory- main clinical use on identification of hearing loss in newborn babies • Clinically sensitive tool for assessing NIHL and the outer hair cells (OHC) • repeatable results • identify cochlear damage before evidenced on an audiogram – normal... audiogram but evidence of OHC loss • Feasible method of evaluating HPD effectiveness using temporary emission shift (TES) • CSIR research developed a prediction model for Hearing Threshold Levels Copy of dancing hair cell.wm © CSIR 2010 Slide 6...

  3. Noise induced chaos in optically driven colloidal rings.

    Science.gov (United States)

    Roichman, Yael; Zaslavsky, George; Grier, David G.

    2007-03-01

    Given a constant flux of energy, many driven dissipative systems rapidly organize themselves into configurations that support steady state motion. Examples include swarming of bacterial colonies, convection in shaken sandpiles, and synchronization in flowing traffic. How simple objects interacting in simple ways self-organize generally is not understood, mainly because so few of the available experimental systems afford the necessary access to their microscopic degrees of freedom. This talk introduces a new class of model driven dissipative systems typified by three colloidal spheres circulating around a ring-like optical trap known as an optical vortex. By controlling the interplay between hydrodynamic interactions and fixed disorder we are able to drive a transition from a previously predicted periodic steady state to fully developed chaos. In addition, by tracking both microscopic trajectories and macroscopic collective fluctuations the relation between the onset of microscopic weak chaos and the evolution of space-time self-similarity in macroscopic transport properties is revealed. In a broader scope, several optical vortices can be coupled to create a large dissipative system where each building block has internal degrees of freedom. In such systems the little understood dynamics of processes like frustration and jamming, fluctuation-dissipation relations and the propagation of collective motion can be tracked microscopically.

  4. Electric Dipole Echoes and Noise-Induced Coherence

    International Nuclear Information System (INIS)

    Mestayer, J.J.; Zhao, W.; Lancaster, J.C.; Dunning, F.B.; Yoshida, S.; Reinhold, Carlos O.; Burgdorfer, J.

    2007-01-01

    The generation of echoes in the electric dipole moment of a Rydberg wavepacket precessing in an external electric field by reversal of the field is described. When the wavepacket experiences reversible dephasing, large echoes are observed pointing to strong refocusing of the wavepacket. The presence of irreversible dephasing leads to a reduction in the size of the echoes. The effect of irreversible dynamics on echoes is investigated using artificially synthesized noise. Methods to determine the decoherence rate are discussed

  5. The noise-induced hearing loss milestones: past and future

    CSIR Research Space (South Africa)

    Edwards, AL

    2012-10-01

    Full Text Available sought to answer the questions: Did we reach the 2008 milestone? What should the industry do now about hearing conservation that will ensure that there is no deterioration in hearing greater than 10% amongst noise-exposed miners? How can we ensure...

  6. Noise-Induced Hearing Loss - A Preventable Disease?

    DEFF Research Database (Denmark)

    Frederiksen, Thomas W.; Ramlau-Hansen, Cecilia H.; Stokholm, Zara A.

    2017-01-01

    AIMS: To survey current, Danish industrial noise levels and the use of hearing protection devices (HPD) over a 10-year period and to characterise the association between occupational noise and hearing threshold shift in the same period. Furthermore, the risk of hearing loss among the baseline and...

  7. Stress Management

    Science.gov (United States)

    ... with regions of your brain that control mood, motivation and fear. The body's stress-response system is ... problems Headaches Heart disease Sleep problems Weight gain Memory and concentration impairment That's why it's so important ...

  8. Stressing academia?

    DEFF Research Database (Denmark)

    Opstrup, Niels; Pihl-Thingvad, Signe

    Incongruences between the individual and the organizational work context are potential stressors. The present study focuses on the relationship between a complementary need-supply fit and Danish researchers’ self-perceived job stress. Strain is expected to increase as organizational supplies fall...... hand, the fit on “hard” dimensions as salary, financial rewards and career opportunities is found to be unrelated to the researchers’ self-perceived stress-level. The fit with regard to job security is an important exception, however....... to “soft” dimensions as freedom and independence in the job, personal and professional development at work, and receiving peer recognition is highly significant for the researchers’ self-perceived stress-level. The better the fit is the lower stress-levels the researchers’ on average report. On the other...

  9. Stress Management

    Directory of Open Access Journals (Sweden)

    Prof.Univ. Dr. Paul Marinescu

    2007-05-01

    Full Text Available In the post-modern management organizational leaders have the obligation of protecting their employees against factors that could cause damages to their potentially wealthy lives. Stress is such a factor. We shall attempt by means of the present article to draw attention on certain general aspects that should be taken into account in drafting plans for fighting against and diminishing the stress faced by the employees

  10. Stress fractures

    International Nuclear Information System (INIS)

    Berquist, T.H.; Cooper, K.L.; Pritchard, D.J.

    1985-01-01

    The diagnosis of a stress fracture should be considered in patients presented with pain after a change in activity, especially if the activity is strenuous and the pain is in the lower extremities. Since evidence of the stress fracture may not be apparent for weeks on routine radiographs, proper use of other imaging techniques will allow an earlier diagnosis. Prompt diagnosis is especially important in the femur, where displacement may occur

  11. Stress response in rat brain after different durations of noise exposure.

    Science.gov (United States)

    Samson, James; Sheeladevi, Rathinasamy; Ravindran, Rajan; Senthilvelan, Manohar

    2007-01-01

    The alteration in the levels of plasma corticosterone, brain norepinephrine (NE), and expression of brain heat shock proteins (Hsp70) after different durations of noise exposure (acute, 1 day; sub-acute, 15 days; chronic, 30 days) has been studied to analyze their role in combating time-dependent stress effects of noise. Broadband white noise (100dB) exposure to male Wistar albino rats significantly increased the levels of plasma corticosterone and NE in all three durations of noise exposure. The sustained increase observed in their levels in the chronic group suggests that animals are not getting adapted to noise even after 30 days of exposure. The important role of Hsp70 in combating noise induced stress is evident from the significant increase in its expression after chronic exposure, while there was a reciprocal decrease in the NE and corticosterone when compared with their levels after acute and sub-acute noise exposure. This clearly indicates that the time-dependent stress response to noise exposure is a complex mechanism involving highly interconnected systems such as hypothalamo-pituitary-adrenal (HPA) axis, heat shock proteins and may have serious implications in vital organs, particularly in the brain when there is a prolonged noise exposure.

  12. Professional stress

    Directory of Open Access Journals (Sweden)

    Stanojević Dragana Z.

    2011-01-01

    Full Text Available Job stress is a line, for the person at work hired adverse physiological, psychological and behavioral reactions to situations in which job requirements are not in accordance with its capabilities, abilities and needs. Sources of stress at work are numerous. Personal factors: personality types have been most studied so far, environmental changes and demographic characteristics as well. Interpersonal stress inducing factors act and influence to the occurrence of many psychosomatic diseases. Psychosocial climate and relationships which are prevented or encouraged such as: cooperation and competition, trust and suspicion certainly affect to the appearance of professional stress. The way of leadership is very important. Organizational factors are the type of work, work time, noncompliance of the job, the introduction of new ethnologies, the conflict of personal roles, fear of job loss, bad physical conditions of working environment. The consequences of stress at work are numerous: at the cognitive level, the emotional level, the production plan, the health, plan reduces the immune system that cause a variety of psychosomatic illnesses and accidents at work.

  13. Stress Analysis

    DEFF Research Database (Denmark)

    Burcharth, Hans F.

    The following types of forces contribute to the stresses in a Dolos in a pack exposed to waves: 1)Gravity forces Compaction forces (mainly due to settlements, gravity and flow forces) 2) Flow forces 3) Impact forces (impacts between moving concrete blocks)......The following types of forces contribute to the stresses in a Dolos in a pack exposed to waves: 1)Gravity forces Compaction forces (mainly due to settlements, gravity and flow forces) 2) Flow forces 3) Impact forces (impacts between moving concrete blocks)...

  14. Welding stresses

    International Nuclear Information System (INIS)

    Poirier, J.; Barbe, B.; Jolly, N.

    1976-01-01

    The aim is to show how internal stresses are generated and to fix the orders of magnitude. A realistic case, the vertical welding of thick plates free to move one against the other, is described and the deformations and stresses are analyzed. The mathematical model UEDA, which accounts for the elastic modulus, the yield strength and the expansion coefficient of the metal with temperature, is presented. The hypotheses and results given apply only to the instantaneous welding of a welded plate and to a plate welded by a moving electrode [fr

  15. Diazepam administration prevents testosterone decrease and lipofuscin accumulation in testis of mouse exposed to chronic noise stress.

    Science.gov (United States)

    Ruffoli, R; Carpi, A; Giambelluca, M A; Grasso, L; Scavuzzo, M C; Giannessi F, F

    2006-10-01

    Lipofuscin is an autofluorescent and undegradable material, which accumulates in tissues during ageing and under different types of stress. Among these, oxidative stress represents a major trigger for lipofuscin formation. However, prolonged noise exposure is also an effective stressful stimuli. Diazepam may inhibit lipofuscinogenesis in liver and prevent the noise-induced reduction of the steroidogenesis in the adrenal gland. The aim of the study was to ascertain whether chronic noise exposure causes lipofuscin accumulation in mouse testis, and to evaluate the effects of diazepam administration. Eight-week old mice were either exposed for 6 weeks (6 h day(-1)) to white-noise (group A), or received diazepam (3 mg kg(-1), i.p.) before noise exposures (group B), while a further group was used as control (group C). Light fluorescence and transmission electron microscopy revealed lipofuscin in large amounts in the Leydig cells in mice of group A, which concomitantly had low serum testosterone levels; pre-treatment with diazepam occluded both effects. The present study indicates that: (i) chronic noise exposure causes lipofuscin accumulation at the level of the Leydig cells and a decrease in testosterone; (ii) all these effects are suppressed by pre-treatment with diazepam. As the Leydig cells represent the only cellular type of the interstitial testicular tissue having peripheral benzodiazepine receptors, these results could be explained by the capacity of the peripheral benzodiazepine receptors to prevent reactive oxygen species damage and to increase the resistance of these cells to oxidative stress.

  16. Bacterial stress

    Indian Academy of Sciences (India)

    First page Back Continue Last page Graphics. Bacterial stress. Physicochemical and chemical parameters: temperature, pressure, pH, salt concentration, oxygen, irradiation. Nutritional depravation: nutrient starvation, water shortage. Toxic compounds: Antibiotics, heavy metals, toxins, mutagens. Interactions with other cells: ...

  17. (stress) testing

    African Journals Online (AJOL)

    However, maximal HR was significantly higher in all groups during their sporting activities than during stress testing in the laboratory (P < 0.01). Conclusions. Maximal HR in veteran athletes during specific sporting activities was significantly higher than that attained during a routine sECG. This finding was not sport-specific, ...

  18. In vivo immunoprotective role of Indigofera tinctoria and Scoparia dulcis aqueous extracts against chronic noise stress induced immune abnormalities in Wistar albino rats.

    Science.gov (United States)

    Madakkannu, Boothapandi; Ravichandran, Ramanibai

    2017-01-01

    Indigofera tinctoria and Scoparia dulcis are being widely used in Indian folk medicine for the treatment of various disorders. Environmental noise pollution is thought to be an important factor for many health problems and it causes immune abnormalities. In the present study immune-regulating potential of I. tinctoria and S. dulcis aqueous extracts on innate and adaptive immune system of wistar albino rats was evaluated during normal and chronic noise induced stress conditions. The results demonstrated that both I. tinctoria and S. dulcis aqueous extracts (200 mg/kg b.w) showed immunostimulant effect on both innate and adaptive immune response of wistar albino rat compared to control group under normal condition. The noise stress (100 dB for 1 h, 20 days) induced animals showed suppressive effects on immune response by decreasing macrophage phagocytosis, antibody secretion by spleen cells, humoral immune response, proliferation of lymphocytes, cytotoxicity, TNF α expression, granzyme B and perforin expression in splenic NK cells. Similarly, noise stress also caused DNA damage in tissues. However, the suppressed effects induced by noise stress on rat immune system were significantly prevented by oral administration of both I. tinctoria and S. dulcis aqueous extracts. Considering all these results it is suggested that the selected medicinal plant's aqueous extracts have the potential to prevent the effects of noise stress induced rat immune system and explore a strong immunostimulant potential applicable to clinical practices.

  19. Stress and Mood

    Science.gov (United States)

    ... Relaxation Emotions & Relationships HealthyYouTXT Tools Home » Stress & Mood Stress & Mood Many people who go back to smoking ... story: Time Out Times 10 >> share What Causes Stress? Read full story: What Causes Stress? >> share The ...

  20. Stress Management: Positive Thinking

    Science.gov (United States)

    Healthy Lifestyle Stress management Positive thinking helps with stress management and can even improve your health. Practice overcoming negative self-talk ... with optimism is a key part of effective stress management. And effective stress management is associated with ...

  1. Stress and your heart

    Science.gov (United States)

    Coronary heart disease - stress; Coronary artery disease - stress ... Your body responds to stress on many levels. First, it releases stress hormones that make you breathe faster. Your blood pressure goes up. Your muscles ...

  2. Repetitive Stress Injuries

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Repetitive Stress Injuries KidsHealth / For Teens / Repetitive Stress Injuries What's ... t had any problems since. What Are Repetitive Stress Injuries? Repetitive stress injuries (RSIs) are injuries that ...

  3. Oxidative stress

    Directory of Open Access Journals (Sweden)

    Stevanović Jelka

    2012-01-01

    Full Text Available The unceasing need for oxygen is in contradiction to the fact that it is in fact toxic to mammals. Namely, its monovalent reduction can have as a consequence the production of short-living, chemically very active free radicals and certain non-radical agents (nitrogen-oxide, superoxide-anion-radicals, hydroxyl radicals, peroxyl radicals, singlet oxygen, peroxynitrite, hydrogen peroxide, hypochlorous acid, and others. There is no doubt that they have numerous positive roles, but when their production is stepped up to such an extent that the organism cannot eliminate them with its antioxidants (superoxide-dismutase, glutathione-peroxidase, catalase, transferrin, ceruloplasmin, reduced glutathion, and others, a series of disorders is developed that are jointly called „oxidative stress.“ The reactive oxygen species which characterize oxidative stress are capable of attacking all main classes of biological macromolecules, actually proteins, DNA and RNA molecules, and in particular lipids. The free radicals influence lipid peroxidation in cellular membranes, oxidative damage to DNA and RNA molecules, the development of genetic mutations, fragmentation, and the altered function of various protein molecules. All of this results in the following consequences: disrupted permeability of cellular membranes, disrupted cellular signalization and ion homeostasis, reduced or loss of function of damaged proteins, and similar. That is why the free radicals that are released during oxidative stress are considered pathogenic agents of numerous diseases and ageing. The type of damage that will occur, and when it will take place, depends on the nature of the free radicals, their site of action and their source. [Projekat Ministarstva nauke Republike Srbije, br. 173034, br. 175061 i br. 31085

  4. Stressed podocytes

    DEFF Research Database (Denmark)

    Svenningsen, Per

    2015-01-01

    and in response to injury induced by endoplasmatic reticulum (ER) stress (Golubinskaya et al., 2015). Their report shed light on the complex regulation of Best3 in podocytes and will help pave the way for future studies on the pathogenesis of kidneys diseases with podocyte injury. This article is protected...... structure appears to be a common finding in acquired proteinuric conditions (Pavenstadt et al., 2003). Identification of genes that are involved in physiological and pathophysiological functions of the podocytes is a major task. Recent studies indicate that Bestrophin (Best) 3 has cell protective functions...... in a number of cell types (Lee et al., 2012, Jiang et al., 2013, Song et al., 2014). In the present issue of Acta Physiologica, Golubinskaya et al. use cultured podocytes, kidneys and isolated glomeruli of the mouse kidney to provide a thorough characterisation of Best3 expression under normal conditions...

  5. Managing Leadership Stress

    CERN Document Server

    Bal, Vidula; McDowell-Larsen, Sharon

    2011-01-01

    Everyone experiences stress, and leaders face the additional stress brought about by the unique demands of leadership: having to make decisions with limited information, to manage conflict, to do more with less . . . and faster! The consequences of stress can include health problems and deteriorating relationships. Knowing what signs of stress to look for and having a strategy for increasing your resources will help you manage leadership stress and be more effective over a long career.Table of ContentsThe Stress of Leadership 7Why Is Leadership Stressful? 8Stress Assessment 13When Stress Is Wh

  6. Stress Management: Yoga

    Science.gov (United States)

    Healthy Lifestyle Stress management Is yoga right for you? It is if you want to fight stress, get fit and stay healthy. By ... particular, may be a good choice for stress management. Hatha is one of the most common styles ...

  7. Stress and Heart Health

    Science.gov (United States)

    ... It Works Healthy Workplace Food and Beverage Toolkit Stress and Heart Health Updated:Jan 8,2018 When ... therapist in your community. Last reviewed 6/2014 Stress Management • Home • How Does Stress Affect You? Introduction ...

  8. Overcoming job stress

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000884.htm Overcoming job stress To use the sharing features on this page, ... stay healthy and feel better. Causes of Job Stress Although the cause of job stress is different ...

  9. Posttraumatic Stress Disorder

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Posttraumatic Stress Disorder (PTSD) KidsHealth / For Parents / Posttraumatic Stress Disorder ( ... My Child? Looking Ahead Print What Is Posttraumatic Stress Disorder (PTSD)? Someone who is the victim of ( ...

  10. Stress Management: Spirituality

    Science.gov (United States)

    Healthy Lifestyle Stress management Taking the path less traveled by exploring your spirituality can lead to a clearer life purpose, better personal relationships and enhanced stress management skills. By Mayo Clinic Staff Some stress relief ...

  11. Teacher Wellness: Too Stressed for Stress Management?

    Science.gov (United States)

    Kipps-Vaughan, Debi; Ponsart, Tyler; Gilligan, Tammy

    2012-01-01

    Healthier, happier teachers promote healthier, happier, and more effective learning environments. Yet, many teachers experience considerable stress. Studies have found that between one fifth and one fourth of teachers frequently experience a great deal of stress (Kyriacou, 1998). Stress in teaching appears to be universal across nations and…

  12. Prenatal Maternal Stress Programs Infant Stress Regulation

    Science.gov (United States)

    Davis, Elysia Poggi; Glynn, Laura M.; Waffarn, Feizal; Sandman, Curt A.

    2011-01-01

    Objective: Prenatal exposure to inappropriate levels of glucocorticoids (GCs) and maternal stress are putative mechanisms for the fetal programming of later health outcomes. The current investigation examined the influence of prenatal maternal cortisol and maternal psychosocial stress on infant physiological and behavioral responses to stress.…

  13. Stress and Health

    DEFF Research Database (Denmark)

    Rod, Naja Hulvej

    2014-01-01

    Background Stress is an important public health issue. One in ten Danish adults experience high levels of stress in their daily lives and stress is one of the main occupational health problems in Europe. The link between stress and health is still debated in the scientific literature...... and the pathways underlying these potential health effects are far from elucidated. The dissertation contributions to the literature on stress and health by empirically testing the relationship between stress and major chronic disorders and by providing new evidence on the underlying physiological, psychological...... and behavioral mechanisms. Stress is a complex concept and in order to better understand the relation between stress and health, the dissertation works with a clear distinction between the health consequences of different types of stress including external stressors, perceived stress, and measures of the stress...

  14. The effect of academic stress and attachment stress on stress-eaters and stress-undereaters.

    Science.gov (United States)

    Emond, Michael; Ten Eycke, Kayla; Kosmerly, Stacey; Robinson, Adele Lafrance; Stillar, Amanda; Van Blyderveen, Sherry

    2016-05-01

    It is well established that stress is related to changes in eating patterns. Some individuals are more likely to increase their overall food intake under conditions of stress, whereas others are more likely to consume less food when stressed. Attachment style has been linked to disordered eating and eating disorders; however, comparisons of eating behaviors under attachment versus other types of stress have yet to be explored. The present laboratory study examined the eating patterns in self-identified stress-undereaters and stress-eaters under various types of stress. More specifically, the study examined the effects of academic and attachment stress on calorie, carbohydrate and sugar consumption within these two groups. Under the guise of critiquing student films, university students viewed either one of two stress-inducing videos (academic stress or attachment stress, both designed to be emotionally arousing) or a control video (designed to be emotionally neutral), and their food intake was recorded. Results demonstrated that the video manipulations were effective in inducing stress. Differential patterns of eating were noted based on group and stress condition. Specifically, stress-undereaters ate fewer calories, carbohydrates and sugars than stress-eaters in the academic stress condition, but not in the attachment stress or control condition. Findings suggest that specific types of stressors may influence eating behaviors differently. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Stress og insomni

    DEFF Research Database (Denmark)

    Jennum, Poul; Zachariae, Bobby

    2012-01-01

    Insomnia and stress are two conditions, which are strongly associated and appear to be pathophysiologically integrated: the occurrence of stress increases the risk of insomnia, insomnia exacerbates stress, and coexistence of both factors has a negative influence on their prognosis. Stress...

  16. Stress og aldring

    DEFF Research Database (Denmark)

    Jørgensen, Anders; Jørgensen, Martin Balslev; Poulsen, Henrik Enghusen

    2012-01-01

    Accumulating evidence supports the popular notion that psychological stress states may accelerate aging. Stress has been shown to influence cellular systems known to be involved in the aging process. Furthermore, stress is associated with an increased risk of various age-related medical disorders....... These effects are likely mediated by the secretion of stress hormones. In this short review we focus on biochemical and epidemiological evidence for a link between stress and aging....

  17. Bruxism affects stress responses in stressed rats.

    Science.gov (United States)

    Sato, Chikatoshi; Sato, Sadao; Takashina, Hirofumi; Ishii, Hidenori; Onozuka, Minoru; Sasaguri, Kenichi

    2010-04-01

    It has been proposed that suppression of stress-related emotional responses leads to the simultaneous activation of both sympathetic and parasympathetic divisions of the autonomic nervous system (ANS) and that the expression of these emotional states has a protective effect against ulcerogenesis. In the present study, we investigated whether stress-induced bruxism activity (SBA) has a physiological effect of on the stress-induced changes of the stomach, thymus, and spleen as well as blood leukocytes, cortisol, and adrenaline. This study demonstrated that SBA attenuated the stress-induced ulcer genesis as well as degenerative changes of thymus and spleen. SBA also attenuated increases of adrenaline, cortisol, and neutrophils in the blood. In conclusion, expression of aggression through SBA during stress exposure attenuates both stress-induced ANS response, including gastric ulcer formation.

  18. Stress and Coping with Stress in Adolescence

    Directory of Open Access Journals (Sweden)

    Petra Dolenc

    2015-12-01

    Full Text Available Because of the many developmental changes in adolescence, young people are exposed to greater likelihood of experiencing stress. On the other hand, this period is critical for developing effective and constructive coping strategies. In the contribution, we summarize part of what is known about stress, stress responses and coping. Throughout, we focus on common stressful events among adolescents and emphasize the importance of dealing successfully with stressors in their daily lives. Finally, we highlight the most frequently used instruments to measure coping behaviour in youth and present an overview of the research findings on differences in coping among adolescents according to age and gender.

  19. Features of infrasonic and ionospheric disturbances generated by launch vehicle

    International Nuclear Information System (INIS)

    Drobzheva, Ya.V.; Krasnov, V.M.; Sokolova, O.I.

    2001-01-01

    In this paper we present a model, which describe the propagation of acoustic pulses through a model terrestrial atmosphere produced by launch vehicle, and effects of these pulses on the ionosphere above the launch vehicle. We show that acoustic pulses generate disturbances of electron density. The value of these disturbances is about 0.04-0.7% of background electron density. So such disturbances can not create serious noise-free during monitoring of explosions by ionospheric method. We calculated parameters of the blast wave generated at the ionospheric heights by launch vehicle. It was shown that the blast wave is intense and it can generates disturbance of electron density which 2.6 times as much then background electron density. This disturbance is 'cord' with diameter about 150-250 m whereas length of radio line is hundreds and thousand km. Duration of ionospheric disturbances are from 0.2 s to 3-5 s. Such values of duration can not be observed during underground and surface explosions. (author)

  20. Infrasonic observations of large-scale HE events

    Science.gov (United States)

    Whitaker, Rodney W.; Mutschlecner, J. Paul; Davidson, Masha B.; Noel, Susan D.

    1990-01-01

    The Los Alamos Infrasound Program has been operating since about mid-1982, making routine measurements of low frequency atmospheric acoustic propagation. Generally, the authors work between 0.1 Hz to 10 Hz; however, much of the work is concerned with the narrower range of 0.5 to 5.0 Hz. Two permanent stations, St. George, UT, and Los Alamos, NM, have been operational since 1983, collecting data 24 hours a day. For the purposes of this discussion, the authors concentrate on their measurements of large, high explosive (HE) events at ranges of 250 km to 5330 km. Because their equipment is well suited for mobile deployments, they can easily establish temporary observing sites for special events. The measurements are from the permanent sites, as well as from various temporary sites. A few observations that are typical of the full data set are given.

  1. Preamplifier with ultra low frequency cutoff for infrasonic condenser microphone

    DEFF Research Database (Denmark)

    Kinnerup, Rasmus Trock; Marbjerg, Kresten; Rasmussen, Per

    2012-01-01

    low frequencies becomes a challenge. The electric preamplifier presented in this paper together with a prepolarized condenser microphone form a measurement system. The developed preamplifier connects the microphone signal directly to the input of an operational amplifier with ultra high input...

  2. Infrasonic detection performance in presence of nuisance signal

    Science.gov (United States)

    Charbit, Maurice; Arrowsmith, Stephen; Che, Il-young; Le Pichon, Alexis; Nouvellet, Adrien; Park, Junghyun; Roueff, Francois

    2014-05-01

    The infrasound network of the International Monitoring System (IMS) consists of sixty stations deployed all over the World by the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO). The IMS has been designed to reliably detect, at least by two stations, an explosion greater than 1 kiloton located anywhere on the Earth [1]. Each station is an array of at least four microbarometers with an aperture of 1 to 3 km. The first important issue is to detect the presence of the signal of interest (SOI) embedded in noise. The detector is commonly based on the property that the SOI provides coherent observations on the sensors but not the noise. The statistic of test, called F-stat [2], [5], [6] , calculated in a time cell a few seconds, is commonly used for this purpose. In this paper, we assume that a coherent source is permanently present arriving from an unknown direction of arrivals (DOA). The typical case is the presence of microbaroms or the presence of wind. This source is seen as a nuisance signal (NS). In [4], [3] authors assume that a time cell without the SOI (CH0) is available, whereas a following time cell is considered as the cell under test (CUT). Therefore the DOA and the SNR of the NS can be estimated. If the signal-to-noise ration SNR of the NS is large enough, the distribution of the F-stat under the absence of SOI is known to be a non central Fisher. It follows that the threshold can be performed from a given value of the FAR. The major drawback to keep the NS is that the NS could hide the SOI, this phenomena is similar to the leakage which is a well-known phenomena in the Fourier analysis. An other approach consists to use the DOA estimate of the NS to mitigate the NS by spatial notch filter in the frequency domain. On this approach a new algorithm is provided. To illustrate, numerical results on synthetical and real data are presented, in term of Receiver Operating Characteristic ROC curves. REFERENCES [1] Christie D.R. and Campus P., The IMS infrasound netwrok: design and establishment of infrasound stations, Infrasound Monitoring for Atmospheric Studies, Springer Netherlands, Editor: Le Pichon, Alexis and Blanc, Elisabeth and Hauchecorne, Alain, pp 27-72, 2010. [2] Shumway R. H.,Advances in Mixed Signal Processing for Regional and Teleseismic Arrays 28th Seismic Research Review: Ground-Based Nuclear Explosion Monitoring Technologies, pp 503-509, 2007. [3] Park J., Hayward C.T., Zeiler C. P., Arrowsmith S.J. and Stump B.W., A Comparative Study of Automated Infrasound Detectors - PMCC and inframonitor with analyst review, SSA Annual Meeting, 2013. [4] Arrowsmith S.J., Whitaker R., Katz C. and Hayward C., The F-Detector Revisited: An Improved Strategy for Signal Detection at Seismic and Infrasound Arrays, Bulletin of the Seismological Society of America, 2008. [5] Arrowsmith S.J., Whitaker R., Steven R. Taylor, Burlacu R., Stump B.W., Hedlin M.A.H., Randall G., Hayward C. and ReVelle D., Regional monitoring of infrasound events using multiple arrays: application to Utah and Washington State, Geophys. J. Int., vol.175, pp 291-300, 2008. [6] Charbit M., Gaillard P. and Le Pichon A., Evaluating the performance of infrasound detectors, EGU, Vienne, Autriche, April 2012.

  3. In vivo immunoprotective role of Indigofera tinctoria and Scoparia dulcis aqueous extracts against chronic noise stress induced immune abnormalities in Wistar albino rats

    Directory of Open Access Journals (Sweden)

    Boothapandi Madakkannu

    Full Text Available Indigofera tinctoria and Scoparia dulcis are being widely used in Indian folk medicine for the treatment of various disorders. Environmental noise pollution is thought to be an important factor for many health problems and it causes immune abnormalities. In the present study immune-regulating potential of I. tinctoria and S. dulcis aqueous extracts on innate and adaptive immune system of wistar albino rats was evaluated during normal and chronic noise induced stress conditions. The results demonstrated that both I. tinctoria and S. dulcis aqueous extracts (200 mg/kg b.w showed immunostimulant effect on both innate and adaptive immune response of wistar albino rat compared to control group under normal condition. The noise stress (100 dB for 1 h, 20 days induced animals showed suppressive effects on immune response by decreasing macrophage phagocytosis, antibody secretion by spleen cells, humoral immune response, proliferation of lymphocytes, cytotoxicity, TNF α expression, granzyme B and perforin expression in splenic NK cells. Similarly, noise stress also caused DNA damage in tissues. However, the suppressed effects induced by noise stress on rat immune system were significantly prevented by oral administration of both I. tinctoria and S. dulcis aqueous extracts. Considering all these results it is suggested that the selected medicinal plant’s aqueous extracts have the potential to prevent the effects of noise stress induced rat immune system and explore a strong immunostimulant potential applicable to clinical practices. Keywords: Indigofera tinctoria, Scoparia dulcis, Chronic noise stress, Immunomodulatory, Innate immunity, Adaptive immunity

  4. Effect of Scoparia dulcis on noise stress induced adaptive immunity and cytokine response in immunized Wistar rats

    Directory of Open Access Journals (Sweden)

    Loganathan Sundareswaran

    2017-01-01

    Conclusion: S. dulcis (SD has normalized and prevented the noise induced changes in cell-mediated and humoral immunity and it could be the presence of anti-stressor and immuno stimulant activity of the plant.

  5. Overall bolt stress optimization

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2013-01-01

    The state of stress in bolts and nuts with International Organization for Standardization metric thread design is examined and optimized. The assumed failure mode is fatigue, so the applied preload and the load amplitude together with the stress concentrations define the connection strength....... Maximum stress in the bolt is found at the fillet under the head, at the thread start, or at the thread root. To minimize the stress concentration, shape optimization is applied. Nut shape optimization also has a positive effect on the maximum stress. The optimization results show that designing a nut......, which results in a more evenly distribution of load along the engaged thread, has a limited influence on the maximum stress due to the stress concentration at the first thread root. To further reduce the maximum stress, the transition from bolt shank to the thread must be optimized. Stress reduction...

  6. Stress at Work Place

    OpenAIRE

    Mohammad A. Shahrour

    2010-01-01

    One of hardest forms of stresses to avoid is that work place or job stress Job stress refers to stress experienced by an individual at or because of issues at their work place The term work related stress has many meanings and it causes different levels of anxiety. Not all challenges at work can be called stress as some of these challenges drive employees upward, and empower them to learn new skills or push them to work harder to achieve a certain goal. So, this type of challenges cannot be c...

  7. Stress: a concept analysis.

    Science.gov (United States)

    Goodnite, Patricia M

    2014-01-01

    To analyze the concept of stress and provide an operational definition of stress. Literature review revealed that stress is a commonly used, but often ambiguous, term. Findings supported a definition of stress entailing an individual's perception of a stimulus as overwhelming, which in turn elicits a measurable response resulting in a transformed state. This analysis adopts a dynamic definition of stress that may serve to encourage communication, promote reflection, and enhance concept understanding. This definition may provide direction for future work, as well as enhance efforts to serve patients affected by stress. © 2013 Wiley Periodicals, Inc.

  8. The stress of life

    National Research Council Canada - National Science Library

    Selye, H

    1978-01-01

    .... This is also a dependable personal guide that tells you how to combat both physical and mental stress, how to handle yourself during the stress of everyday life, and how your bodily changes can help...

  9. Stress and Migraine

    Science.gov (United States)

    ... Spotlight On News Content Capsule Contact Understanding Migraine Stress and Migraine Doctor Q&A Managing Migraine Migraine ... of Headache Disorders Cluster Headache Post-Traumatic Headache Stress and Migraine March 16, 2017 How to cope ...

  10. Institutional Preventive Stress Management.

    Science.gov (United States)

    Quick, James C.

    1987-01-01

    Stress is an inevitable characteristic of academic life, but colleges and universities can introduce stress management activities at the organizational level to avert excessive tension. Preventive actions are described, including flexible work schedules and social supports. (Author/MSE)

  11. Stress og aldring

    DEFF Research Database (Denmark)

    Jørgensen, Anders; Jørgensen, Martin Balslev; Poulsen, Henrik Enghusen

    2012-01-01

    Accumulating evidence supports the popular notion that psychological stress states may accelerate aging. Stress has been shown to influence cellular systems known to be involved in the aging process. Furthermore, stress is associated with an increased risk of various age-related medical disorders....... These effects are likely mediated by the secretion of stress hormones. In this short review we focus on biochemical and epidemiological evidence for a link between stress and aging.......Accumulating evidence supports the popular notion that psychological stress states may accelerate aging. Stress has been shown to influence cellular systems known to be involved in the aging process. Furthermore, stress is associated with an increased risk of various age-related medical disorders...

  12. Neuroepigenetics of stress.

    Science.gov (United States)

    Griffiths, B B; Hunter, R G

    2014-09-05

    Stress, a common if unpredictable life event, can have pronounced effects on physiology and behavior. Individuals show wide variation in stress susceptibility and resilience, which are only partially explained by variations in coding genes. Developmental programing of the hypothalamic-pituitary-adrenal stress axis provides part of the explanation for this variance. Epigenetic approaches have successfully helped fill the explanatory gaps between the influences of gene and environment on stress responsiveness, and differences in the sequelae of stress across individuals and generations. Stress and the stress axis interacts bi-directionally with epigenetic marks within the brain. It is now clear that exposure to stress, particularly in early life, has both acute and lasting effects on these marks. They in turn influence cognitive function and behavior, as well as the risk for suicide and psychiatric disorders across the lifespan and, in some cases, unto future generations. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  13. Stress and Health

    DEFF Research Database (Denmark)

    Rod, Naja Hulvej

    2014-01-01

    and behavioral mechanisms. Stress is a complex concept and in order to better understand the relation between stress and health, the dissertation works with a clear distinction between the health consequences of different types of stress including external stressors, perceived stress, and measures of the stress......’s disease patients. Results The combined evidence of this dissertation shows a moderately higher risk of some common chronic disorders including cardiovascular disease and atopic disorders among individuals exposed to work-related stressors and perceived stress. Most empirical studies also report higher...... of pathways. The physiological stress response has the ability to directly affect vital body systems including the cardiovascular, immune, and metabolic systems. Further, stress can lead to unfavorable changes in health-related behavior, impaired sleep and poor mental health. An increasing number of well...

  14. Optimization of Bolt Stress

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2013-01-01

    The state of stress in bolts and nuts with ISO metric thread design is examined and optimized. The assumed failure mode is fatigue so the applied preload and the load amplitude together with the stress concentrations define the connection strength. Maximum stress in the bolt is found at, the fillet...... under the head, at the thread start or at the thread root. To minimize the stress concentration shape optimization is applied....

  15. Stress og insomni

    DEFF Research Database (Denmark)

    Jennum, Poul; Zachariae, Bobby

    2012-01-01

    Insomnia and stress are two conditions, which are strongly associated and appear to be pathophysiologically integrated: the occurrence of stress increases the risk of insomnia, insomnia exacerbates stress, and coexistence of both factors has a negative influence on their prognosis. Stress...... and insomnia thus share complex interactions and the mechanisms involved are insufficiently understood but involve both psychological and physiological processes. First choice interventions involve behavioural and cognitive strategies and, to a lesser extent, pharmacological treatment....

  16. Stress and Protists: No life without stress.

    Science.gov (United States)

    Slaveykova, Vera; Sonntag, Bettina; Gutiérrez, Juan Carlos

    2016-08-01

    We report a summary of the symposium "Stress and Protists: No life without stress", which was held in September 2015 on the VII European Congress of Protistology in partnership with the International Society of Protistologists (Seville, Spain). We present an overview on general comments and concepts on cellular stress which can be also applied to any protist. Generally, various environmental stressors may induce similar cell responses in very different protists. Two main topics are reported in this manuscript: (i) metallic nanoparticles as environmental pollutants and stressors for aquatic protists, and (ii) ultraviolet radiation - induced stress and photoprotective strategies in ciliates. Model protists such as Chlamydomonas reinhardtii and Tetrahymena thermophila were used to assess stress caused by nanoparticles while stress caused by ultraviolet radiation was tested with free living planktonic ciliates as well as with the symbiont-bearing model ciliate Paramecium bursaria. For future studies, we suggest more intensive analyses on protist stress responses to specific environmental abiotic and/or biotic stressors at molecular and genetic levels up to ecological consequences and food web dynamics. Copyright © 2016 Elsevier GmbH. All rights reserved.

  17. Managing Stress. Project Seed.

    Science.gov (United States)

    Muto, Donna; Wilk, Jan

    One of eight papers from Project Seed, this paper describes a stress management project undertaken with high school sophomores. Managing Stress is described as an interactive workshop that offers young people an opportunity to examine specific areas of stress in their lives and to learn effective ways to deal with them. The program described…

  18. Stress i gymnasiet

    DEFF Research Database (Denmark)

    Nielsen, Anne Maj; Lagermann, Laila Colding

    Denne undersøgelse af stress hos gymnasieelever i Aalborg viser, hvordan stress giver sig udslag i gymnasiet, hvad der stresser eleverne, hvad der adskiller de stressramte elever fra andre elever, hvordan et stressreduktionskurset Åben og Rolig for Unge virker for de unge i gymnasiet, og hvad der...... kan modvirke stress i gymnasiet....

  19. Oxidative Stress in BPH

    Directory of Open Access Journals (Sweden)

    Murat Savas

    2009-01-01

    The present study has shown that there were not relationship between potency of oxidative stress and BPH. Further well designed studies should be planned to find out whether the oxidative stress-related parameters play role in BPH as an interesting pathology in regard of the etiopathogenesis. Keywords: benign prostatic hyperplasia, oxidative stress, prostate

  20. The price of stress

    NARCIS (Netherlands)

    Groot, W.; Maassen, van den H.

    1999-01-01

    In this paper an economic approach is taken to the analysis of work-related stress. This economic approach not only allows us to infer the monetary equivalent of stress, it also enables us to test some of the psychological theories on stress, such as the demand/control theory. Evidence is found that

  1. Leadership and Occupational Stress

    Science.gov (United States)

    Stickle, Fred E.; Scott, Kelly

    2016-01-01

    In a leadership position, it is important to understand what stress is and how it affects others. In an occupational setting, stressors vary according to personality types, gender, and occupational rank. The purpose of this manuscript is to review the foundations of stress and to explore how personality characteristics influence stress.…

  2. Occupational Stress among Teachers.

    Science.gov (United States)

    Albertson, Larry M.; Kagan, Dona M.

    1987-01-01

    Two studies were conducted to investigate the degree to which occupational stress among teachers could be attributed to personal characteristics of the individuals themselves. The first study developed dispositional stress scales. The second examined correlations between these scales, occupational stress scales, and teachers' attitudes toward…

  3. Sleep, Stress & Relaxation: Rejuvenate Body & Mind

    Science.gov (United States)

    Sleep, Stress & Relaxation: Rejuvenate Body & Mind; Relieve Stress; best ways to relieve stress; best way to relieve stress; different ways to relieve stress; does smoking relieve stress; does tobacco relieve stress; how can I relieve stress; how can you relieve stress; how do I relieve stress; reduce stress; does smoking reduce stress; how can I reduce stress; how to reduce stress; reduce stress; reduce stress levels; reducing stress; smoking reduce stress; smoking reduces stress; stress reducing techniques; techniques to reduce stress; stress relief; best stress relief; natural stress relief; need stress relief; relief for stress; relief from stress; relief of stress; smoking and stress relief; smoking for stress relief; smoking stress relief; deal with stress; dealing with stress; dealing with anger; dealing with stress; different ways of dealing with stress; help dealing with stress; how to deal with anger; how to deal with stress; how to deal with stress when quitting smoking; stress management; free stress management; how can you manage stress; how do you manage stress; how to manage stress; manage stress; management of stress; management stress; managing stress; strategies for managing stress; coping with stress; cope with stress; copeing with stress; coping and stress; coping skills for stress; coping strategies for stress; coping strategies with stress; coping strategy for stress; coping with stress; coping with stress and anxiety; emotional health; emotional health; emotional health article; emotional health articles; deep relaxation; deep breathing relaxation techniques; deep muscle relaxation; deep relaxation; deep relaxation meditation; deep relaxation technique; deep relaxation techniques; meditation exercises; mindful exercises; mindful meditation exercises; online relaxation exercises; relaxation breathing exercises; relaxation exercise; relaxation exercises; stress relaxation; methods of relaxation for stress; relax stress; relax techniques stress

  4. Stress and headache chronification.

    Science.gov (United States)

    Houle, Timothy; Nash, Justin M

    2008-01-01

    In this special section, the concept of stress has been linked to the chronification of headache and is considered to be one of several likely mechanisms for the progression of an otherwise episodic disorder to a chronic daily phenomenon. The present review discusses the concept of stress and describes the mechanisms through which stress could influence headache progression. The hypothesized mechanisms include stress serving as a unique trigger for individual attacks, as a nociceptive activator, and as a moderator of other mechanisms. Finally, the techniques used in the screening and management of stress are mentioned in the context of employing strategies for the primary, secondary, or tertiary prevention of headache progression.

  5. Neuropeptide Y and Stress

    Directory of Open Access Journals (Sweden)

    Murat Gulsun

    2012-03-01

    Full Text Available The neurobiological aspects of stress and coping skills has been the focus of interest for many researchers. Some of the studies has shown that there is a significant relationship among genetically variables, stress response and life events. Neuropeptide Y is one of the systems regulating the stress response. Under the prolonged or repeated trauma neuropeptide Y is released from the brain's key areas. This system shows different levels of functioning in individuals with different levels of resilience. There is particular interest in the variations of genes that encode stress-sensitive signaling molecules during gene-environment interaction. This condition may contribute to susceptibility of stress or stress resilience. Neuropeptide Y system plays a key role in the adaptation to behavioral stress. The reduced levels of neuropeptide Y have also been observed in treatment-resistant depression and posttraumatic stress disorder. Lower level of neuropeptide Y expression and dysfunctional neuropeptide Y system in response to stress and resulting decreased stress resilience could increase susceptibility to stress-related disorders.

  6. Stress Reactivity in Insomnia.

    Science.gov (United States)

    Gehrman, Philip R; Hall, Martica; Barilla, Holly; Buysse, Daniel; Perlis, Michael; Gooneratne, Nalaka; Ross, Richard J

    2016-01-01

    This study examined whether individuals with primary insomnia (PI) are more reactive to stress than good sleepers (GS). PI and GS (n = 20 per group), matched on gender and age, completed three nights of polysomnography. On the stress night, participants received a mild electric shock and were told they could receive additional shocks during the night. Saliva samples were obtained for analysis of cortisol and alpha amylase along with self-report and visual analog scales (VAS). There was very little evidence of increased stress on the stress night, compared to the baseline night. There was also no evidence of greater stress reactivity in the PI group for any sleep or for salivary measures. In the GS group, stress reactivity measured by VAS scales was positively associated with an increase in sleep latency in the experimental night on exploratory analyses. Individuals with PI did not show greater stress reactivity compared to GS.

  7. Stress and Cancer

    DEFF Research Database (Denmark)

    Christoffer, Johansen,; Sørensen, Ivalu; Lim Høeg, Beverly

    2017-01-01

    The role of stress in relation to cancer remains controversial. Stress is assumed to be an emerging public health problem in modern society. Still, we argue that it is relevant to view the role of stress in cancer from a scientific point of view. A critical overview of existing evidence...... is presented through previous review studies, and the importance of methodological challenges is highlighted. We summarize the evidence on the role of stress as a cause of cancer, on the impact of stress on cancer prognosis, and on how coping mechanisms may influence stress levels in cancer patients. Finally......, we describe the evidence on interventions to relieve stress in cancer patients for the purpose of improving both well-being and cancer prognosis. Against public opinion, we critically dismiss the evidence on psychotherapy as a tool to prolong life after cancer as inconsistent and unresolved....

  8. Oxidative Stress in Neurodegeneration

    Directory of Open Access Journals (Sweden)

    Varsha Shukla

    2011-01-01

    Full Text Available It has been demonstrated that oxidative stress has a ubiquitous role in neurodegenerative diseases. Major source of oxidative stress due to reactive oxygen species (ROS is related to mitochondria as an endogenous source. Although there is ample evidence from tissues of patients with neurodegenerative disorders of morphological, biochemical, and molecular abnormalities in mitochondria, it is still not very clear whether the oxidative stress itself contributes to the onset of neurodegeneration or it is part of the neurodegenerative process as secondary manifestation. This paper begins with an overview of how oxidative stress occurs, discussing various oxidants and antioxidants, and role of oxidative stress in diseases in general. It highlights the role of oxidative stress in neurodegenerative diseases like Alzheimer's, Parkinson's, and Huntington's diseases and amyotrophic lateral sclerosis. The last part of the paper describes the role of oxidative stress causing deregulation of cyclin-dependent kinase 5 (Cdk5 hyperactivity associated with neurodegeneration.

  9. Pain stress and headache.

    Science.gov (United States)

    Panerai, Alberto E

    2012-05-01

    The association between pain and stress is an old one, but still it is not really clear who comes first. Pain induces stress, and stress induces pain. Pain is part of our homeostatic system and in this way is an emotion, i.e., it tells us that something is out-of-order (control), and emotion drives our behavior and one behavior is stress response. Stress comes from ourselves: the imagination we have or would like to have of us, from the image others give of us, from the goals we assume it is necessary to reach for our well-being or the goals others want us to fulfill. Stress comes from our social condition and the condition we would like, stress comes from dangerous situations we cannot control. Headache easily fits in the picture.

  10. [Stress in surgeries].

    Science.gov (United States)

    Daian, Márcia Rodrigues; Petroianu, Andy; Alberti, Luiz Ronaldo; Jeunon, Ester Eliane

    2012-01-01

    The purpose of this article was to provide the literature regarding the psychological stress in the peri-operative period of adult patients undergoing operations under general anesthesia. The articles were obtained by surveying the papers published and catalogued in the Medline Pubmed interface database, Lilacs and the Biblioteca Virtual de Saúde (BVS) since 1984, crossing the headings stress, surgery, general anesthesia, psychology. Over 800 articles related to stress and surgery were analyzed with regards to their relevance to the considered subject. Eighteen articles were related to psychological stress. Their results confirmed the presence of psychological and physical stress, during the peri-operative period as well as relation between stress and de clinical post-operative recovery. There is a gap regarding in the peri-operative period. More studies on psychological influence on stress may benefit patients and help professionals during the surgical treatment.

  11. Stress Management and Gifted Children

    Science.gov (United States)

    Patel, Vidisha A.

    2009-01-01

    Stress can affect anyone, and gifted children are no exception. Giftedness can sometimes be the cause of the stress. Perfectionism, sensitivity, and intensity are characteristics of gifted children that may exacerbate stress. Stress can be constructive. Prolonged stress, however, with no time to recover becomes detrimental. Continued stress upsets…

  12. Interoception and Stress

    Directory of Open Access Journals (Sweden)

    André eSchulz

    2015-07-01

    Full Text Available Afferent neural signals are continuously transmitted from visceral organs to the brain. Interoception refers to the processing of visceral-afferent neural signals by the central nervous system, which can finally result in the conscious perception of bodily processes. Interoception can, therefore, be described as a prominent example of information processing on the ascending branch of the brain-body axis. Stress responses involve a complex neuro-behavioral cascade, which is elicited when the organism is confronted with a potentially harmful stimulus. As this stress cascade comprises a range of neural and endocrine pathways, stress can be conceptualized as a communication process on the descending branch of the brain-body axis. Interoception and stress are, therefore, associated via the bi-directional transmission of information on the brain-body axis. It could be argued that excessive and/or enduring activation (e.g. by acute or chronic stress of neural circuits, which are responsible for successful communication on the brain-body axis, induces malfunction and dysregulation of these information processes. As a consequence, interoceptive signal processing may be altered, resulting in physical symptoms contributing to the development and/or maintenance of body-related mental disorders, which are associated with stress. In the current paper, we summarize findings on psychobiological processes underlying acute and chronic stress and their interaction with interoception. While focusing on the role of the physiological stress axes (HPA axis and autonomic nervous system, psychological factors in acute and chronic stress are also discussed. We propose a feed-forward model involving stress (in particular early life or chronic stress, as well as major adverse events, the dysregulation of physiological stress axes, altered perception of bodily sensations, and the generation of physical symptoms, which may in turn facilitate stress.

  13. Stress transmission in soil

    DEFF Research Database (Denmark)

    Lamandé, Mathieu; Schjønning, Per

    We urgently need increased quantitative knowledge on stress transmission in real soils loaded with agricultural machinery. 3D measurements of vertical stresses under tracked wheels were performed in situ in a Stagnic Luvisol (clay content 20 %) continuously cropped with small grain cereals......). Seven load cells were inserted horizontally from a pit with minimal disturbance of soil in each of three depths (0.3, 0.6 and 0.9 m), covering the width of the wheeled area. The position of the wheel relative to the transducers was recorded using a laser sensor. Finally, the vertical stresses near...... the soil-tyre interface were measured in separate tests by 17 stress transducers across the width of the tyres. The results showed that the inflation pressure controlled the level of maximum stresses at 0.3 m depth, while the wheel load was correlated to the measured stresses at 0.9 m depth. This supports...

  14. Learning During Stressful Times

    Science.gov (United States)

    Shors, Tracey J.

    2012-01-01

    Stressful life events can have profound effects on our cognitive and motor abilities, from those that could be construed as adaptive to those not so. In this review, I discuss the general notion that acute stressful experience necessarily impairs our abilities to learn and remember. The effects of stress on operant conditioning, that is, learned helplessness, as well as those on classical conditioning procedures are discussed in the context of performance and adaptation. Studies indicating sex differences in learning during stressful times are discussed, as are those attributing different responses to the existence of multiple memory systems and nonlinear relationships. The intent of this review is to highlight the apparent plasticity of the stress response, how it might have evolved to affect both performance and learning processes, and the potential problems with interpreting stress effects on learning as either good or bad. An appreciation for its plasticity may provide new avenues for investigating its underlying neuronal mechanisms. PMID:15054128

  15. Stresses in Dolosse

    DEFF Research Database (Denmark)

    Burcharth, Hans F.; Liu, Zhou; Howell, Gary L.

    1991-01-01

    Failures of rubble mound breakwaters armoured with complex types of unreinforced concrete armour units are often due to breakage. This happens when the stresses exceed the material strength. Sufficient parametric studies of the stresses are not yet available to produce design diagrams for structu......Failures of rubble mound breakwaters armoured with complex types of unreinforced concrete armour units are often due to breakage. This happens when the stresses exceed the material strength. Sufficient parametric studies of the stresses are not yet available to produce design diagrams...... for structural integrity. The paper presents the results and the analyses of model tests with 200 kg and 200 g load-cell instrumented Dolosse. Static stresses and wave generated stresses were studied as well as model and scale effects. A preliminary design diagram for Dolosse is presented as well....

  16. Stress Erythropoiesis Model Systems.

    Science.gov (United States)

    Bennett, Laura F; Liao, Chang; Paulson, Robert F

    2018-01-01

    Bone marrow steady-state erythropoiesis maintains erythroid homeostasis throughout life. This process constantly generates new erythrocytes to replace the senescent erythrocytes that are removed by macrophages in the spleen. In contrast, anemic or hypoxic stress induces a physiological response designed to increase oxygen delivery to the tissues. Stress erythropoiesis is a key component of this response. It is best understood in mice where it is extramedullary occurring in the adult spleen and liver and in the fetal liver during development. Stress erythropoiesis utilizes progenitor cells and signals that are distinct from bone marrow steady-state erythropoiesis. Because of that observation many genes may play a role in stress erythropoiesis despite having no effect on steady-state erythropoiesis. In this chapter, we will discuss in vivo and in vitro techniques to study stress erythropoiesis in mice and how the in vitro culture system can be extended to study human stress erythropoiesis.

  17. The teacher under stress

    OpenAIRE

    Krnjajić Stevan B.

    2003-01-01

    Empirical records consistently point to the fact that the phenomenon of stress is characteristic of service professions, especially of teacher’s. Although stress in teachers is a problem of public interest, it is still a relatively new field of empirical investigations. Data available show that stress in teachers can have negative effects on school as an organization teacher professional achievement, his/her and his/her family psychosocial status. The most frequent symptoms of a prolonged pro...

  18. Rock stress investigations

    International Nuclear Information System (INIS)

    Pahl, A.; Heusermann, St.; Braeuer, V.; Gloeggler, W.

    1989-04-01

    On the research project 'Rock Stress Mesurements' the BGR has developed and tested several methods for use in boreholes at a depth of 200 m. Indirect stress measurements using overcoring methods with BGR-probes and CSIR-triaxial cells as well as direct stress measurements using the hydraulic-fracturing method were made. To determine in-situ rock deformation behavior borehole deformation tests, using a BGR-dilatometer, were performed. Two types of the BGR-probe were applied: a four-component-probe to determine horizontal stresses and a five-component-probe to determine a quasi three-dimensional stress field. The first time a computer for data processing was installed in the borehole together with the BGR-probe. Laboratory tests on low cylinders were made to study the stress-deformation behavior. To validate and to interprete the measurement results some test methods were modelled using the finite-element method. The dilatometer-tests yielded high values of Young's modulus, whereas laboratory tests showed lower values with a distinct deformation anisotropy. Stress measurements with the BGR-probe yielded horizontal stresses being higher than the theoretical overburden pressure. These results are comparable to the results of the hydraulic fracturing tests, whereas stresses obtained with CSIR-triaxial cells are lower. The detailed geological mapping of the borehole indicated relationships between stress and geology. With regard to borehole depth different zones of rock structure joint frequency, joint orientation, and orientation of microfissures as well as stress magnitude, stress direction, and degree of deformation anisotropy could be distinguished. (author) 4 tabs., 76 figs., 31 refs

  19. Stress and hormones

    Directory of Open Access Journals (Sweden)

    Salam Ranabir

    2011-01-01

    Full Text Available In the modern environment one is exposed to various stressful conditions. Stress can lead to changes in the serum level of many hormones including glucocorticoids, catecholamines, growth hormone and prolactin. Some of these changes are necessary for the fight or flight response to protect oneself. Some of these stressful responses can lead to endocrine disorders like Graves′ disease, gonadal dysfunction, psychosexual dwarfism and obesity. Stress can also alter the clinical status of many preexisting endocrine disorders such as precipitation of adrenal crisis and thyroid storm.

  20. The teacher under stress

    Directory of Open Access Journals (Sweden)

    Krnjajić Stevan B.

    2003-01-01

    Full Text Available Empirical records consistently point to the fact that the phenomenon of stress is characteristic of service professions, especially of teacher’s. Although stress in teachers is a problem of public interest, it is still a relatively new field of empirical investigations. Data available show that stress in teachers can have negative effects on school as an organization teacher professional achievement, his/her and his/her family psychosocial status. The most frequent symptoms of a prolonged professional stress are anxiety, depression, frustration, unfriendly behavior towards students and colleagues, emotional weariness, and extreme tension. Health and psychological problems cause, most frequently, the reduction of self-esteem job dissatisfaction, job resignation, absenteeism, and wrong decision-making. In an attempt to call professional public attention to negative effects of stress on the outcomes of teacher work, we have analyzed four important aspects of stress teachers experience in their everyday work (a definition and measurement of stress, (b distribution and sources of stress (problem behaviors in students, poor working conditions, lack of time, poor school ethos, (c teacher personality traits (sex, age, work experience, locus of control, job satisfaction, intention to resign absenteeism, (d strategies for overcoming and reducing negative effects of stress (direct action techniques, palliative techniques.

  1. Theory of thermal stresses

    CERN Document Server

    Boley, Bruno A

    1997-01-01

    Highly regarded text presents detailed discussion of fundamental aspects of theory, background, problems with detailed solutions. Basics of thermoelasticity, heat transfer theory, thermal stress analysis, more. 1985 edition.

  2. Forecasting Financial Stress

    OpenAIRE

    Jan Willem Slingenberg; Jakob de Haan

    2011-01-01

    This paper uses a Financial Stress Index (FSI) for 13 OECD countries to examine which variables can help predicting financial stress. A stress index measures the current state of stress in the financial system and summarizes it in a single statistic. We employ three criteria for indicators to be used in constructing a multi-country FSI (the index covers the entire financial system, indicators used are available at a high frequency for many countries for a long period, and are comparable) to c...

  3. Management of Occupational Stress

    Directory of Open Access Journals (Sweden)

    Trandafir Lenuţa

    2015-06-01

    Full Text Available Stress is an important problem in the majority of countries. Apart from the fact that it is responsible for numerous diseases, it also causes much suffering. Stress appears as an adaptation reaction of our body to those external factors that we perceive as being agressive and which frequently lead us to an alarm state, felt both psychically (tension, fear, anxiety, and physically (increase of the adrenaline secretion, intensity of heartbeats, sweating. It isn’t actually a disease, but it can lead to sickness in time. This is why it is good to know what stresses us and how we can escape stress.

  4. Stress: Concepts and applications

    International Nuclear Information System (INIS)

    Nielsen, O.H.; Martin, R.M.

    1984-01-01

    The stress theorem determines the stress from the electronic ground state of any quantum system with arbitrary strains and atomic displacements. We derive this theorem in reciprocal space, within the local-density-functional approximation. The evaluation of stress, force and total energy permits, among other things, the determination of complete stress-strain relations including all microscopic internal strains. We describe results of ab-initio calculations for Si, Ge, and GaAs, giving the equilibrium lattice constant, all linear elastic constants c ij and the internal strain parameter ζ. (orig.)

  5. STRESS IN ORGANIZATIONS

    Directory of Open Access Journals (Sweden)

    Maria-Elena, GHEORDUNESCU

    2014-11-01

    Full Text Available Taking into account the changes that are currently taking place in our country, it is clear that these changes, which occur in almost all companies, lead to new stress factors for both employees and the organization. Occupational stress is a major problem for employees and managers, but also for the whole society. The issue of stress in organizations has given birth to many debates and studies. It is a common theme that is addressed by managers, employees and consultants from different perspectives. According to a study by the European Agency for Safety and Health at Work, in the European Union, work-related stress is the second work-related health issue after dorsal disorders. It affects 28% of EU employees. The European Parliament is fully involved in addressing issues related to the psychological support of the staff. Preventing work-related stress is one of the objectives set out in the Communique of the European Commission for Employment and Social Affairs regarding their new health and safety at work strategy. Manifestations of stress in organizations are easily observable, being manifested by behaviors such as: difficulties in adapting to the changes required to work or the dramatic drop in labor productivity. Also a double action is met: both the person who passes through the stressful situation and at the organization level on which it is reflected the existence of a stressful environment. This paper aims to address the implications of workplace stress, symptoms of stress in the workplace and strategies to eliminate and prevent stress at work This paper represents an exploratory research based on qualitative methods, being consulted various sources of information: the literature, case studies, media articles, reports of relevant organizations, etc.

  6. Stress Management: Social Support

    Science.gov (United States)

    Healthy Lifestyle Stress management Having close friends and family has far-reaching benefits for your health. Here's how to build and maintain these ... article: http://www.mayoclinic.org/healthy-lifestyle/stress-management/in-depth/social-support/art-20044445 . Mayo Clinic ...

  7. Stress Management: Massage

    Science.gov (United States)

    Healthy Lifestyle Stress management Massage can be a powerful tool to help you take charge of your health and well-being. See if ... article: http://www.mayoclinic.org/healthy-lifestyle/stress-management/in-depth/massage/art-20045743 . Mayo Clinic Footer ...

  8. Stress Management for Sport.

    Science.gov (United States)

    Zaichkowsky, Leonard D., Ed.; Sime, Wesley E., Ed.

    Included in this volume are papers on stress management in athletics; eight of the ten papers are followed with a "Coach's Reaction": (1) "Competitive Athletic Stress Factors in Athletes and Coaches" (Walter Kroll); (2) "Mental Preparation for Peak Performance in Swimmers" (Eugene F. Gauron)--Coach's Reaction by Suzi…

  9. Stress of stoicism

    DEFF Research Database (Denmark)

    Doan, Stacey N.; Dich, Nadya; Evans, Gary W.

    2016-01-01

    The present longitudinal study examined the combined effects of task persistence and negative emotionality (NE) on allostatic load (AL), a physiological indicator of chronic stress. In line with John Henryism theory, we hypothesized that high persistence combined with low NE may be indicative...... persistence was associated with higher physiological stress. Our results have implications for both clinical and intervention contexts....

  10. Videnarbejde og stress

    DEFF Research Database (Denmark)

    Buch, Anders; Andersen, Vibeke; Sørensen, Ole Henning

    . Videnarbejde kan for den enkelte være vejen til selvrealisering og begejstring, men rummer også i sig kimen til stress og udbrændthed. Og det er netop i spændingsfeltet - i kampen - mellem begejstring og belastning, at bogen ser stress i det moderne arbejdsliv, som en uoverensstemmelse mellem ydre krav og...

  11. Stress and reward

    DEFF Research Database (Denmark)

    Chumbley, J R; Hulme, O; Köchli, H

    2014-01-01

    Healthy individuals tend to consume available rewards like food and sex. This tendency is attenuated or amplified in most stress-related psychiatric conditions, so we asked if it depends on endogenous levels of the 'canonical stress hormone' cortisol. We unobtrusively quantified how hard healthy...

  12. Stress and your health

    Science.gov (United States)

    ... way of protecting itself. When you have chronic stress, your body stays alert, even though there is no danger. Over time, this puts you at risk for health problems, including: ... condition, chronic stress can make it worse. SIGNS OF TOO MUCH ...

  13. Stress and Fear Extinction

    Science.gov (United States)

    Maren, Stephen; Holmes, Andrew

    2016-01-01

    Stress has a critical role in the development and expression of many psychiatric disorders, and is a defining feature of posttraumatic stress disorder (PTSD). Stress also limits the efficacy of behavioral therapies aimed at limiting pathological fear, such as exposure therapy. Here we examine emerging evidence that stress impairs recovery from trauma by impairing fear extinction, a form of learning thought to underlie the suppression of trauma-related fear memories. We describe the major structural and functional abnormalities in brain regions that are particularly vulnerable to stress, including the amygdala, prefrontal cortex, and hippocampus, which may underlie stress-induced impairments in extinction. We also discuss some of the stress-induced neurochemical and molecular alterations in these brain regions that are associated with extinction deficits, and the potential for targeting these changes to prevent or reverse impaired extinction. A better understanding of the neurobiological basis of stress effects on extinction promises to yield novel approaches to improving therapeutic outcomes for PTSD and other anxiety and trauma-related disorders. PMID:26105142

  14. Stress - Multiple Languages

    Science.gov (United States)

    ... and Well-Being 1 - Stress - Amarɨñña / አማርኛ (Amharic) MP3 Siloam Family Health Center Arabic (العربية) Expand Section ... and Well-Being 1 - Stress - myanma bhasa (Burmese) MP3 Siloam Family Health Center Chinese, Simplified (Mandarin dialect) ( ...

  15. Neuropathology of stress

    NARCIS (Netherlands)

    Lucassen, P.J.; Pruessner, J.; Sousa, N.; Almeida, O.F.X.; van Dam, A.M.; Rajkowska, G.; Swaab, D.F.; Czéh, B.

    2014-01-01

    Environmental challenges are part of daily life for any individual. In fact, stress appears to be increasingly present in our modern, and demanding, industrialized society. Virtually every aspect of our body and brain can be influenced by stress and although its effects are partly mediated by

  16. CD-ROM Stress.

    Science.gov (United States)

    Bunge, Charles A.

    1991-01-01

    Discussion of stress in library reference departments focuses on stress caused by CD-ROM reference tools. Topics discussed include work overload; nonreference duties; patron attitudes and behavior; staff attitudes; the need for proper staff training; and the need for library administrators to be sensitive to reference staff needs. (LRW)

  17. Release from Stress.

    Science.gov (United States)

    Gmelch, Walter H.

    An overview of the most recent ideas on managerial stress is presented along with worksheets and exercises for a program to help educational administrators, their staffs, and secretaries cope with and reduce organizational and personal stress. Research cited includes the author's survey of 1,200 Oregon school administrators and over 200…

  18. Prenatal stress in pigs

    NARCIS (Netherlands)

    Kranendonk, Godelieve

    2006-01-01

    Studies in many species, including humans, have demonstrated that stress during gestation can have long-term developmental, neuroendocrine, and behavioural effects on the offspring. Because pregnant sows can be subjected to regular stressful situations, it is relevant to study whether prenatal

  19. Photobiomodulation on Stress

    Directory of Open Access Journals (Sweden)

    Timon Cheng-Yi Liu

    2012-01-01

    Full Text Available Photobiomodulation (PBM is a nondamaged modulation of laser irradiation or monochromatic light (LI on a biosystem function. It depends on whether the function is in its function-specific homeostasis (FSH. An FSH is a negative-feedback response of a biosystem to maintain the function-specific conditions inside the biosystem so that the function is perfectly performed. A function in its FSH is called a normal function. A function far from its FSH is called a dysfunctional function. The process of a function from dysfunctional to normal is called a functional normalization. For a normal function in its FSH, there are FSH-essential subfunctions (FESs, FSH-nonessential subfunctions (FNSs, and an FES/FNS-specific homeostasis (FESH/FNSH. A FSH can resist internal/external disturbances under the threshold, but can be disrupted by an FSH-specific stress (FSS. A normal/dysfunctional FSS is called a successful/chronic stress. An FESH/FNSH-specific stress was called an extraordinary/ordinary stress. A low level LI (LLL cannot directly affect a normal function, but can modulate a chronic stress. A normal function may have a chronic ordinary stress, and an LLL may modulate the chronic ordinary stress so that it promotes the normalization of the dysfunctional FNS and then upgrades the normal function. A high level LI can modulate a normal function and may be a successful stress.

  20. Allometric trajectories and "stress"

    NARCIS (Netherlands)

    Anfodillo, Tommaso; Petit, Giai; Sterck, Frank; Lechthaler, Silvia; Olson, Mark E.

    2016-01-01

    The term "stress" is an important but vague term in plant biology. We show situations in which thinking in terms of "stress" is profitably replaced by quantifying distance from functionally optimal scaling relationships between plant parts. These relationships include, for example, the

  1. Stress, arousal, and sleep

    NARCIS (Netherlands)

    Sanford, Larry D.; Suchecki, Deborah; Meerlo, Peter; Meerlo, Peter; Benca, Ruth M.; Abel, Ted

    2015-01-01

    Stress is considered to be an important cause of disrupted sleep and insomnia. However, controlled and experimental studies in rodents indicate that effects of stress on sleep-wake regulation are complex and may strongly depend on the nature of the stressor. While most stressors are associated with

  2. Relaxation techniques for stress

    Science.gov (United States)

    ... raise your heart rate. This is called the stress response. Relaxation techniques can help your body relax and lower your blood pressure ... also many other types of breathing techniques you can learn. In many cases, you do not need much ... including those that cause stress. Meditation has been practiced for thousands of years, ...

  3. Expressive stress relievers

    NARCIS (Netherlands)

    Bruns Alonso, M.; Varkevisser, M.; Keyson, D.V.

    2012-01-01

    In this paper we describe three tangible interfaces that recognize stress by how they are manipulated and provide tactile feedback to support stress reduction. They were developed following a research through design methodology, in an iterative process of observing behavior, building prototypes, and

  4. Work-related stress

    NARCIS (Netherlands)

    Houtman, I.L.D.

    2005-01-01

    Changes in the content and organisation of work in recent decades have resulted in an intensification of work, which is commonly regarded as a cause of stress. This report presents trends in the risks and consequences of work-related stress, and identifies how these can be prevented. The focus

  5. Stress in childhood

    Science.gov (United States)

    ... body changes, in both boys and girls Seeing parents go through a divorce or separation Money problems in the family Living in an unsafe home or neighborhood SIGNS OF UNRESOLVED STRESS IN ... lead parents to suspect an increased stress level is present. ...

  6. Stress and disorders of the stress system.

    Science.gov (United States)

    Chrousos, George P

    2009-07-01

    All organisms must maintain a complex dynamic equilibrium, or homeostasis, which is constantly challenged by internal or external adverse forces termed stressors. Stress occurs when homeostasis is threatened or perceived to be so; homeostasis is re-established by various physiological and behavioral adaptive responses. Neuroendocrine hormones have major roles in the regulation of both basal homeostasis and responses to threats, and are involved in the pathogenesis of diseases characterized by dyshomeostasis or cacostasis. The stress response is mediated by the stress system, partly located in the central nervous system and partly in peripheral organs. The central, greatly interconnected effectors of this system include the hypothalamic hormones arginine vasopressin, corticotropin-releasing hormone and pro-opiomelanocortin-derived peptides, and the locus ceruleus and autonomic norepinephrine centers in the brainstem. Targets of these effectors include the executive and/or cognitive, reward and fear systems, the wake-sleep centers of the brain, the growth, reproductive and thyroid hormone axes, and the gastrointestinal, cardiorespiratory, metabolic, and immune systems. Optimal basal activity and responsiveness of the stress system is essential for a sense of well-being, successful performance of tasks, and appropriate social interactions. By contrast, excessive or inadequate basal activity and responsiveness of this system might impair development, growth and body composition, and lead to a host of behavioral and somatic pathological conditions.

  7. Assessment of Workplace Stress: Occupational Stress, Its Consequences, and Common Causes of Teacher Stress.

    Science.gov (United States)

    Hansen, Jo-Ida; Sullivan, Brandon A.

    This chapter introduces teachers and other education professionals to the assessment of occupational stress. It begins with a brief discussion of what occupational stress is, and overview of the consequences of prolonged stress, and a review of the common causes of teacher stress. Next, it presents methods for reducing occupational stress through…

  8. Bolt Stress Monitor

    Science.gov (United States)

    1978-01-01

    In photo, an engineer is using a new Ultrasonic Bolt Stress Monitor developed by NASA's Langley Research Center to determine whether a bolt is properly tightened. A highly accurate device, the monitor is an important tool in construction of such structures as pressure vessels, bridges and power plants, wherein precise measurement of the stress on a tightened bolt is critical. Overtightened or undertightened bolts can fail and cause serious industrial accidents or costly equipment break-downs. There are a number of methods for measuring bolt stress. Most widely used and least costly is the torque wrench, which is inherently inaccurate; it does not take into account the friction between nut and bolt, which has an influence on stress. At the other end of the spectrum, there are accurate stress-measuring systems, but they are expensive and not portable. The battery-powered Langley monitor fills a need; it is inexpensive, lightweight, portable and extremely accurate because it is not subject to friction error. Sound waves are transmitted to the bolt and a return signal is received. As the bolt is tightened, it undergoes changes in resonance due to stress, in the manner that a violin string changes tone when it is tightened. The monitor measures the changes in resonance and provides a reading of real stress on the bolt. The device, patented by NASA, has aroused wide interest and a number of firms have applied for licenses to produce it for the commercial market.

  9. [Osteoporosis and stress].

    Science.gov (United States)

    Kumano, Hiroaki

    2005-09-01

    There may be three ways of relationship between stress and osteoporosis. The first is that stress induces some physiological changes leading to osteoporosis. The second is that stress induces behavioral distortion of eating, drinking, exercise, and sleep habits, which leads to osteoporosis. The third is that osteoporosis, on the other hand, brings about anxiety, depression, loss of social roles, and social isolation, which leads to stress. The susceptible sex and age groups are postmenopausal women and young women. The abrupt decrease of estrogen in postmenopausal women promotes reabsorption of bone, and it was also reported that the increase of interleukin-6 (IL-6) that is downstream of estrogen was related to the production of osteoclast and to the development of disability of the aged. Regarding the association with stress, while it was reported that depression or depressive states directly increased inflammation-induced cytokines including IL-6, it was also pointed out that stress-induced easy infectious may produce chronic infection, which indirectly increases inflammation-induced cytokines. Anorexia Nervosa that is assumed to be associated with adolescent developmental stress is noteworthy in young women. Amenorrhea is always present in this disease, and in addition to bone reabsorption associated with estrogen deficiency, the decrease of bone formation associated with malnutrition may be related to the development of osteoporosis.

  10. Stress, the hippocampus, and epilepsy

    NARCIS (Netherlands)

    Joëls, M.

    2009-01-01

    Stress is among the most frequently self-reported precipitants of seizures in patients with epilepsy. This review considers how important stress mediators like corticotropin-releasing hormone, corticosteroids, and neurosteroids could contribute to this phenomenon. Cellular effects of stress

  11. Children and Stress

    OpenAIRE

    Johansson, Camilla

    2000-01-01

    Abstract This paper is about children and stress. Stress among children is a serious problem and to be aware of that as a preschool teacher is very important. I’ve focused on the youngest children in preschool. I’ve searched for information in litterateur and articles. To fins literature is not a problem because it is a lot written about this subject. I did two interviews with three preschool teachers. All my sources agree that stress among children is a problem that we must try to work again...

  12. Pacing stress echocardiography

    Directory of Open Access Journals (Sweden)

    Agrusta Marco

    2005-12-01

    Full Text Available Abstract Background High-rate pacing is a valid stress test to be used in conjunction with echocardiography; it is independent of physical exercise and does not require drug administration. There are two main applications of pacing stress in the echo lab: the noninvasive detection of coronary artery disease through induction of a regional transient dysfunction; and the assessment of contractile reserve through peak systolic pressure/ end-systolic volume relationship at increasing heart rates to assess global left ventricular contractility. Methods The pathophysiologic rationale of pacing stress for noninvasive detection of coronary artery disease is obvious, with the stress determined by a controlled increase in heart rate, which is a major determinant of myocardial oxygen demand, and thereby tachycardia may exceed a fixed coronary flow reserve in the presence of hemodynamically significant coronary artery disease. The use of pacing stress echo to assess left ventricular contractile reserve is less established, but promising. Positive inotropic interventions are mirrored by smaller end-systolic volumes and higher end-systolic pressures. An increased heart rate progressively increases the force of ventricular contraction (Bowditch treppe or staircase phenomenon. To build the force-frequency relationship, the force is determined at different heart rate steps as the ratio of the systolic pressure (cuff sphygmomanometer/end-systolic volume index (biplane Simpson rule. The heart rate is determined from ECG. Conclusion Two-dimensional echocardiography during pacing is a useful tool in the detection of coronary artery disease. Because of its safety and ease of repeatability noninvasive pacing stress echo can be the first-line stress test in patients with permanent pacemaker. The force-frequency can be defined as up- sloping (normal when the peak stress pacing systolic pressure/end-systolic volume index is higher than baseline and intermediate stress

  13. Basic stress analysis

    CERN Document Server

    Iremonger, M J

    1982-01-01

    BASIC Stress Analysis aims to help students to become proficient at BASIC programming by actually using it in an important engineering subject. It also enables the student to use computing as a means of learning stress analysis because writing a program is analogous to teaching-it is necessary to understand the subject matter. The book begins by introducing the BASIC approach and the concept of stress analysis at first- and second-year undergraduate level. Subsequent chapters contain a summary of relevant theory, worked examples containing computer programs, and a set of problems. Topics c

  14. Bolt Thread Stress Optimization

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2012-01-01

    of threads and therefore indirectly the bolt fatigue life. The root shape is circular, and from shape optimization for minimum stress concentration it is well known that the circular shape is seldom optimal. An axisymmetric Finite Element (FE) formulation is used to analyze the bolted connection, and a study...... is performed to establish the need for contact modeling with regard to finding the correct stress concentration factor. Optimization is performed with a simple parameterization with two design variables. Stress reduction of up to 9% is found in the optimization process, and some similarities are found...... in the optimized designs leading to the proposal of a new standard. The reductions in the stress are achieved by rather simple changes made to the cutting tool....

  15. Clinical Stress Echocardiography

    NARCIS (Netherlands)

    S.E. Karagiannis

    2007-01-01

    textabstractTwo-dimensional echocardiography is a commonly used non-invasive method for the assessment of left ventricular function. It provides precise information on both global and segmental myocardial function by displaying endocardial motion and wall thickening. Dobutamine stress

  16. Occupational stress among dentists

    DEFF Research Database (Denmark)

    Moore, Rod

    2011-01-01

    Dentists report a high degree of occupational stress.(Cooper, Mallinger, and Kahn, 1978;Coster, Carstens, and Harris, 1987;DiMatteo, Shugars, and Hays, 1993;Hakeberg et al., 1992;Möller and Spangenberg, 1996;Moore, 2000;Myers and Myers, 2004;O'Shea, Corah, and Ayer, 1984) This chapter reviews...... the literature of studies that elaborate on the circumstances of occupational stress of dentists. These will include the frequency of occurrence of occupational stress among dentists in several countries, frequency and intensity of identified stressors specific to dentistry, as well as the consequences...... of this occupational stress. The literature on consequences includes effects on dentists' physical health, personal and occupational performance, including "burnout" phenomena, as well as topics of alcohol or substance abuse and reports of suicidal behaviour among dentists. One specific and less conventionally...

  17. Survival pathways under stress

    Indian Academy of Sciences (India)

    First page Back Continue Last page Graphics. Survival pathways under stress. Bacteria survive by changing gene expression. pattern. Three important pathways will be discussed: Stringent response. Quorum sensing. Proteins performing function to control oxidative damage.

  18. Stress tolerant plants

    OpenAIRE

    Rubio, Vicente; Iniesto Sánchez, Elisa; Irigoyen Miguel, María Luisa

    2014-01-01

    [EN] The invention relates to transgenic plants and methods for modulating abscisic acid (ABA) perception and signal transduction in plants. The plants find use in increasing yield in plants, particularly under abiotic stress.

  19. Stress in Humanitarian Workers

    African Journals Online (AJOL)

    user

    recognized as one of the most serious occupational health hazards reducing workers' satisfaction and productivity,. 1-3 ... Using a self- ... Kan D, Yu X. Occupational Stress, Work-Family. Conflict and Depressive Symptoms among Chinese.

  20. Thermal stress and seismogenesis

    International Nuclear Information System (INIS)

    Zhou Huilan; Wei Dongping

    1989-05-01

    In this paper, the Fourier stress method was applied to deal with the problem of plane thermal stress, and a computing formula was given. As an example, we set up a variate temperature field to describe the uplifted upper mantle in Bozhong area of China, and the computing results shows that the maximum value of thermal plane shear stress is up to nearly 7x10 7 P α in two regions of this area. Since the Bohai earthquake (18 July, 1969, M s = 7.4) occurred at the edge of one of them and Tangshan earthquake (28 July, 1976, M s = 7.8) within another, their occurrences can be related reasonably to the thermal stress. (author). 15 refs, 7 figs

  1. MICRONUTRIENTS AND STRESS

    African Journals Online (AJOL)

    that both mental stress and nutritional factors are associated with the .... tract infections in endurance athletes." Vitamin ... the risk of breast cancer in women with very low intakes and .... smokers, and would be achieved by dietary means alone.

  2. Stress and Your Health

    Science.gov (United States)

    ... A. (2013). Sex differences in stress-related receptors: “micro” differences with “macro” implications for mood and anxiety disorders . Biology of Sex Differences ; 4(2). Goyal, M., Singh, S., ...

  3. Disruption of ion-trafficking system in the cochlear spiral ligament prior to permanent hearing loss induced by exposure to intense noise: possible involvement of 4-hydroxy-2-nonenal as a mediator of oxidative stress.

    Directory of Open Access Journals (Sweden)

    Taro Yamaguchi

    Full Text Available Noise-induced hearing loss is at least in part due to disruption of endocochlear potential, which is maintained by various K(+ transport apparatuses including Na(+, K(+-ATPase and gap junction-mediated intercellular communication in the lateral wall structures. In this study, we examined the changes in the ion-trafficking-related proteins in the spiral ligament fibrocytes (SLFs following in vivo acoustic overstimulation or in vitro exposure of cultured SLFs to 4-hydroxy-2-nonenal, which is a mediator of oxidative stress. Connexin (Cx26 and Cx30 were ubiquitously expressed throughout the spiral ligament, whereas Na(+, K(+-ATPase α1 was predominantly detected in the stria vascularis and spiral prominence (type 2 SLFs. One-hour exposure of mice to 8 kHz octave band noise at a 110 dB sound pressure level produced an immediate and prolonged decrease in the Cx26 expression level and in Na+, K(+-ATPase activity, as well as a delayed decrease in Cx30 expression in the SLFs. The noise-induced hearing loss and decrease in the Cx26 protein level and Na(+, K(+-ATPase activity were abolished by a systemic treatment with a free radical-scavenging agent, 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl, or with a nitric oxide synthase inhibitor, N(ω-nitro-L-arginine methyl ester hydrochloride. In vitro exposure of SLFs in primary culture to 4-hydroxy-2-nonenal produced a decrease in the protein levels of Cx26 and Na(+, K(+-ATPase α1, as well as Na(+, K(+-ATPase activity, and also resulted in dysfunction of the intercellular communication between the SLFs. Taken together, our data suggest that disruption of the ion-trafficking system in the cochlear SLFs is caused by the decrease in Cxs level and Na(+, K(+-ATPase activity, and at least in part involved in permanent hearing loss induced by intense noise. Oxidative stress-mediated products might contribute to the decrease in Cxs content and Na(+, K(+-ATPase activity in the cochlear lateral wall structures.

  4. Stress in Nursing Students

    Directory of Open Access Journals (Sweden)

    Sofia Zyga

    2013-01-01

    Full Text Available Throughout a Nursing academic course, students are confronted by situations that generate stress. Students from professionalizing Nursing courses are especially demanded at practical skills, such asperforming invasive procedures with venous punctures, bandaging, hygiene, and comfort care in patients with different degrees of illness. For these students, stress levels may render learning difficulty with the possibility of leading to errors, lack of concentration and oscillation of attention levels.

  5. Stress studies in EFG

    Science.gov (United States)

    1983-01-01

    Stress distributions were calculated for a creep law to predict a rate of plastic deformation. The expected reduction in stresses is obtained. Improved schemes for calculating growth system temperature distributions were evaluated. Temperature field modeling examined the possibility of using horizontal temperature gradients to influence stress distribution in ribbon. The defect structure of 10 cm wide ribbon grown in the cartridge system was examined. A new feature is identified from an examination of cross sectional micrographs. It consists of high density dislocation bands extending through the ribbon thickness. A four point bending apparatus was constructed for high temperature study of the creep response of silicon, to be used to generate defects for comparison with as grown defects in ribbon. The feasibility of laser interferometric techniques for sheet residual stress distribution measurement is examined. The mathematical formalism for calculating residual stress from changes in surface topology caused by an applied stress in a rectangular specimen was developed, and the system for laser interferometric measurement to obtain surface topology data was tested on CZ silicon.

  6. Student under stress

    Directory of Open Access Journals (Sweden)

    Krnjajić Stevan

    2006-01-01

    Full Text Available Stress is a natural phenomenon, sooner or later experienced by the most Rapid increase in the number of students with health problems, seeking health and advisory services, causes deep concern to parents, schools and wider community. This, in turn, arouses the interest in the research of the negative effects of poor physical and mental health on academic success. Considering the fact that school age population was rarely the subject of research, this paper deals with psycho-social and developmental aspects of stress, namely, with causes, consequences and the strategies for overcoming stressful events in the education of children and adolescents. Life events in which children most often participate and which are also potential sources of stress (stressors can be classified into familial, interpersonal, personal and academic. Out of numerous identified sources of stress, we have focused our attention on several less researched ones in the field of school life starting school, transition from primary school to secondary and from secondary school to university, peer rejection and problems concerning financing school education. Anxiety, depression and anger were analyzed as the most frequent consequences of unfavorable life events. The following strategies for overcoming stress are most often used by children and adolescents: seeking social support, problem-solving orientation, reduction and avoidance of tension as well as sport and recreation.

  7. Stress and asthma

    Directory of Open Access Journals (Sweden)

    Shoji Nagata

    1999-01-01

    Full Text Available Three factors in recent medical research and treatment (advances in the field of psychoneuroimmunology, epidemiological evidence regarding important interaction between psychosocial factors and development of disease, and the recognition of the importance of patient education for self-management of asthma have led clinicians and researchers to reconsider the role of psychosocial stress in asthma. There are many reports suggesting that stressful life events, family problems and a behavior pattern that increases psychological conflict may influence the development or relapse of asthma and influence its clinical course. Depression is known as one of the risk factors of fatal asthmatic attack. In laboratory studies, about 20% of asthmatics were considered reactors who showed an airway change after exposure to emotional stress. Studies regarding the pathway of stress effect on allergy and asthma are reviewed and discussed from the standpoint of psychoneuroimmunology; for example, the enhancement of IgE production and increased susceptibility to respiratory infection by stress, conditioned anaphylaxis and nerve/mast cell interaction, the effect of stress on various bronchial responses and the inhibition of the immediate and late asthmatic response by anterior hypothalamic lesioning.

  8. Stressful life events, vulnerable to stress and depression among ...

    African Journals Online (AJOL)

    The present study was carried out to observe the difference between male and female Eritrean students on the basis of stressful life events, vulnerable to stress and depression. Stressful life Events Questionnaire, Vulnerable to Stress Instrument and Beck Depression Scale were administered to gather information. The data ...

  9. Does oxidative stress shorten telomeres?

    NARCIS (Netherlands)

    Boonekamp, Jelle J.; Bauch, Christina; Mulder, Ellis; Verhulst, Simon

    Oxidative stress shortens telomeres in cell culture, but whether oxidative stress explains variation in telomere shortening in vivo at physiological oxidative stress levels is not well known. We therefore tested for correlations between six oxidative stress markers and telomere attrition in nestling

  10. Job stress and occupational health

    NARCIS (Netherlands)

    Blanc, Le P.M.; Jonge, de J.; Schaufeli, W.B.; Chmiel, N.

    2008-01-01

    This chapter focuses on job stress in relation to workers’ physical and psycho logical health. We begin with an outline of job stress as a social problem, fol lowed by a discussion of the main perspectives on (job) stress, resulting in a process model of job stress that will be used as a frame of

  11. Stress in hard metal films

    NARCIS (Netherlands)

    Janssen, G.C.A.M.; Kamminga, J.D.

    2004-01-01

    In the absence of thermal stress, tensile stress in hard metal films is caused by grain boundary shrinkage and compressive stress is caused by ion peening. It is shown that the two contributions are additive. Moreover tensile stress generated at the grain boundaries does not relax by ion

  12. Stress echocardiography expert consensus statement

    NARCIS (Netherlands)

    R. Sicari (Rosa); P. Nihoyannopoulos (Petros); A. Evangelista (Arturo); J. Kasprzak (Jaroslav); P. Lancellotti (Patrizio); D. Poldermans (Don); J.U. Voigt; J.L. Zamorano (Jose)

    2008-01-01

    textabstractStress echocardiography is the combination of 2D echocardiography with a physical, pharmacological or electrical stress. The diagnostic end point for the detection of myocardial ischemia is the induction of a transient worsening in regional function during stress. Stress echocardiography

  13. Staphylococcal response to oxidative stress

    Directory of Open Access Journals (Sweden)

    Rosmarie eGaupp

    2012-03-01

    Full Text Available Staphylococci are a versatile genus of bacteria that are capable of causing acute and chronic infections in diverse host species. The success of staphylococci as pathogens is due in part to their ability to mitigate endogenous and exogenous oxidative and nitrosative stress. Endogenous oxidative stress is a consequence of life in an aerobic environment; whereas, exogenous oxidative and nitrosative stress are often due to the bacteria’s interaction with host immune systems. To overcome the deleterious effects of oxidative and nitrosative stress, staphylococci have evolved protection, detoxification, and repair mechanisms that are controlled by a network of regulators. In this review, we summarize the cellular targets of oxidative stress, the mechanisms by which staphylococci sense oxidative stress and damage, oxidative stress protection and repair mechanisms, and regulation of the oxidative stress response. When possible, special attention is given to how the oxidative stress defense mechanisms help staphylococci control oxidative stress in the host.

  14. Stress, Epigenetics, and Alcoholism

    Science.gov (United States)

    Moonat, Sachin; Pandey, Subhash C.

    2012-01-01

    Acute and chronic stressors have been associated with alterations in mood and increased anxiety that may eventually result in the development of stress-related psychiatric disorders. Stress and associated disorders, including anxiety, are key factors in the development of alcoholism because alcohol consumption can temporarily reduce the drinker’s dysphoria. One molecule that may help mediate the relationship between stress and alcohol consumption is brain-derived neurotrophic factor (BDNF), a protein that regulates the structure and function of the sites where two nerve cells interact and exchange nerve signals (i.e., synapses) and which is involved in numerous physiological processes. Aberrant regulation of BDNF signaling and alterations in synapse activity (i.e., synaptic plasticity) have been associated with the pathophysiology of stress-related disorders and alcoholism. Mechanisms that contribute to the regulation of genetic information without modification of the DNA sequence (i.e., epigenetic mechanisms) may play a role in the complex control of BDNF signaling and synaptic plasticity—for example, by modifying the structure of the DNA–protein complexes (i.e., chromatin) that make up the chromosomes and thereby modulating the expression of certain genes. Studies regarding the epigenetic control of BDNF signaling and synaptic plasticity provide a promising direction to understand the mechanisms mediating the interaction between stress and alcoholism. PMID:23584115

  15. [Complex posttraumatic stress disorder].

    Science.gov (United States)

    Green, Tamar; Kotler, Moshe

    2007-11-01

    The characteristic symptoms resulting from exposure to an extreme trauma include three clusters of symptoms: persistent experience of the traumatic event, persistent avoidance of stimuli associated with the trauma and persistent symptoms of increased arousal. Beyond the accepted clusters of symptoms for posttraumatic stress disorder exists a formation of symptoms related to exposure to extreme or prolonged stress e.g. childhood abuse, physical violence, rape, and confinement within a concentration camp. With accumulated evidence of the existence of these symptoms began a trail to classify a more complex syndrome, which included, but was not confined to the symptoms of posttraumatic stress disorder. This review addresses several subjects for study in complex posttraumatic stress disorder, which is a complicated and controversial topic. Firstly, the concept of complex posttraumatic stress disorder is presented. Secondly, the professional literature relevant to this disturbance is reviewed and finally, the authors present the polemic being conducted between the researchers of posttraumatic disturbances regarding validity, reliability and the need for separate diagnosis for these symptoms.

  16. Pain in Times of Stress

    OpenAIRE

    AHMAD, Asma Hayati; ZAKARIA, Rahimah

    2015-01-01

    Stress modulates pain perception, resulting in either stress-induced analgesia or stress-induced hyperalgesia, as reported in both animal and human studies. The responses to stress include neural, endocrine, and behavioural changes, and built-in coping strategies are in place to address stressors. Peculiar to humans are additional factors that modulate pain that are experienced in times of stress, notably psychological factors that potentially influence the directionality of pain perception.

  17. Coping with Stress

    DEFF Research Database (Denmark)

    Nunes, Ines Marques

    is to provide insights into the ecological role of soil microbes living in a community and its capabilities to cope with short- and long-term stresses. In the introduction, the problem of using RNA based approaches in soil ecology is presented in parallel with the importance of soil microbes for the ecosystem...... research directions is presented. This PhD-thesis resulted in four draft-manuscripts where RNA sequencing techniques were used to answer different research questions related to the response of soil microorganisms to different types of stress: MANUSCRIPT 1 explores the effect of soil sieving...... towards microwaving-heat were detected and corresponded to traits conserved at high taxonomical level. Moreover, using the detected tolerance ranges, it was possible to point nitrification as “at risk” in systems exposed to rapid heat stress, even though some functional redundancy may have occurred...

  18. Posttraumatisk stress efter arbejdsulykker

    DEFF Research Database (Denmark)

    Rasmussen, K; Lauritsen, Jens; Hansen, O N

    1999-01-01

    This study focuses on post-traumatic stress disorder in a follow up one to two years after the occupational accident. The aim was to estimate the prevalence of PTSD, changes in general health status and issues of compensation. The material was all serious accidents registered in the Danish National...... of posttraumatic stress disorder as a chronic state was 2.8% (102 persons), of whom half had been given compensation. Among the most severe accidents the prevalence was 7.6%. In conclusion, in a large cohort of persons with moderate and severe occupational injuries this study demonstrated that post......-traumatic stress disorder and lasting psychological distress should be a matter for concern in addition to the physical injury....

  19. Stress fractures in athletes

    International Nuclear Information System (INIS)

    Kirschberger, R.; Henning, A.; Graff, K.H.

    1984-01-01

    The early exclusion of the presence of a stress fracture may be decisive for the success of an athlete. Scintigraphy with a bone-seeking radiopharmaceutical is suitable for the early detection of stress lesions. Of 30 athletes, fractures were demonstrated in 17 whereas in 6 they were excluded. We found most fractures in the tarsal bones such as os naviculare pedis, ossa cuneiformia and talus. The type of sport engaged in appears to be an important factor in determining the location of the fracture. Scintiphotos were taken in several views using region of interest techniques and two phase-scintigraphy. This method is considered to be useful for localization and follow-up of skeletal stress lesions as well as for differential diagnosis. (orig.) [de

  20. Stress fractures in athletes

    Energy Technology Data Exchange (ETDEWEB)

    Kirschberger, R; Henning, A; Graff, K H

    1984-12-01

    The early exclusion of the presence of a stress fracture may be decisive for the success of an athlete. Scintigraphy with a bone-seeking radiopharmaceutical is suitable for the early detection of stress lesions. Of 30 athletes, fractures were demonstrated in 17 whereas in 6 they were excluded. We found most fractures in the tarsal bones such as os naviculare pedis, ossa cuneiformia and talus. The type of sport engaged in appears to be an important factor in determining the location of the fracture. Scintiphotos were taken in several views using region of interest techniques and two phase-scintigraphy. This method is considered to be useful for localization and follow-up of skeletal stress lesions as well as for differential diagnosis.

  1. Stress wave focusing transducers

    Energy Technology Data Exchange (ETDEWEB)

    Visuri, S.R., LLNL

    1998-05-15

    Conversion of laser radiation to mechanical energy is the fundamental process behind many medical laser procedures, particularly those involving tissue destruction and removal. Stress waves can be generated with laser radiation in several ways: creation of a plasma and subsequent launch of a shock wave, thermoelastic expansion of the target tissue, vapor bubble collapse, and ablation recoil. Thermoelastic generation of stress waves generally requires short laser pulse durations and high energy density. Thermoelastic stress waves can be formed when the laser pulse duration is shorter than the acoustic transit time of the material: {tau}{sub c} = d/c{sub s} where d = absorption depth or spot diameter, whichever is smaller, and c{sub s} = sound speed in the material. The stress wave due to thermoelastic expansion travels at the sound speed (approximately 1500 m/s in tissue) and leaves the site of irradiation well before subsequent thermal events can be initiated. These stress waves, often evolving into shock waves, can be used to disrupt tissue. Shock waves are used in ophthalmology to perform intraocular microsurgery and photodisruptive procedures as well as in lithotripsy to fragment stones. We have explored a variety of transducers that can efficiently convert optical to mechanical energy. One such class of transducers allows a shock wave to be focused within a material such that the stress magnitude can be greatly increased compared to conventional geometries. Some transducer tips could be made to operate regardless of the absorption properties of the ambient media. The size and nature of the devices enable easy delivery, potentially minimally-invasive procedures, and precise tissue- targeting while limiting thermal loading. The transducer tips may have applications in lithotripsy, ophthalmology, drug delivery, and cardiology.

  2. Stressed skin panels

    Energy Technology Data Exchange (ETDEWEB)

    Anon

    2001-07-01

    Advantages and disadvantages of stressed skin panels, also known as structural insulated panels (SIPs), are discussed as material and labour-saving alternatives to traditional stick framing. Stressed skin panels are manufactured 'sandwich' assemblies with a rigid insulating polystyrene foam core, whose interior and exterior surfaces are bonded into panels. The skins distribute and carry the structural loading while the bonded foam core provides insulation and keeps the two skins aligned. Since there are fewer framing members, there is little thermal bridging and the R-value remains high. SIPs are usually manufactured in four feet by eight feet panels, although some manufacturers can produce panels up to eight feet by forty feet. SIPs are resource efficient as they use less wood than conventional framing (about 25 per cent less); can structurally cover large spans, requiring less supplementary framing. Use of SIPs eliminate the need for headers over small openings; provide the ability to nail anywhere; create less scrap and waste; lessen vulnerability to unfavourable weather and other job-site hazards, can reduce delays, and often can produce significant savings in material and labour costs. Limitations include the more complex approaches to plumbing and electrical systems, although this can be minimized by designers by incorporating much of the plumbing and electrical work on interior (non-panel) walls. Most stressed skin panels require one-half inch interior gypsum drywall. If become wet, stressed skin panels take a long time to dry out and may harbour mold growth. Larger stressed-skin panels used in floors and roofs, may require cranes or other machinery for handling because of their weight. Although not without some environmental impact, overall, stressed skin panels are judged to be a resource-efficient building technology with significant energy-efficiency benefits and distinct advantages over stick framing. 3 photos.

  3. Flow stress anisotropy

    DEFF Research Database (Denmark)

    Winther, G.

    1996-01-01

    stress Variation in the rolling plane, which may be as high as 20%, are presented. The traditional Taylor model is applied to the data to account for the effect of texture. However, texture effects alone are not enough to explain all of the observed anisotropy. New models which take the combined effects...... of texture and deformation microstructure into account are presented. The models are based on the Taylor and Sachs models but modified with an anisotropic critical shear stress to account for the effect of the microstructure. The agreement between experimental data and model predictions is definitely better...

  4. Thyro-stress

    Directory of Open Access Journals (Sweden)

    Sanjay Kalra

    2017-01-01

    Full Text Available Our understanding of the biopsychosocial model of health, and its influence on chronic endocrine conditions, has improved over the past few decades. We can distinguish, for example, between diabetes distress and major depressive disorders in diabetes. Similar to diabetes distress, we suggest the existence of “thyrostress” in chronic thyroid disorders. Thyro-stress is defined as an emotional state, characterized by extreme apprehension, discomfort or dejection, caused by the challenges and demand of living with thyroid disorders such as hypothyroidism. This communication describes the etiology, clinical features, differential diagnosis, and management of thyro-stress.

  5. Thyro-stress.

    Science.gov (United States)

    Kalra, Sanjay; Verma, Komal; Balhara, Yatan Pal Singh

    2017-01-01

    Our understanding of the biopsychosocial model of health, and its influence on chronic endocrine conditions, has improved over the past few decades. We can distinguish, for example, between diabetes distress and major depressive disorders in diabetes. Similar to diabetes distress, we suggest the existence of "thyrostress" in chronic thyroid disorders. Thyro-stress is defined as an emotional state, characterized by extreme apprehension, discomfort or dejection, caused by the challenges and demand of living with thyroid disorders such as hypothyroidism. This communication describes the etiology, clinical features, differential diagnosis, and management of thyro-stress.

  6. Residual-stress measurements

    Energy Technology Data Exchange (ETDEWEB)

    Ezeilo, A N; Webster, G A [Imperial College, London (United Kingdom); Webster, P J [Salford Univ. (United Kingdom)

    1997-04-01

    Because neutrons can penetrate distances of up to 50 mm in most engineering materials, this makes them unique for establishing residual-stress distributions non-destructively. D1A is particularly suited for through-surface measurements as it does not suffer from instrumental surface aberrations commonly found on multidetector instruments, while D20 is best for fast internal-strain scanning. Two examples for residual-stress measurements in a shot-peened material, and in a weld are presented to demonstrate the attractive features of both instruments. (author).

  7. Road traffic noise-induced sleep disturbances: a comparison between laboratory and field settings

    Science.gov (United States)

    Skånberg, Annbritt

    2004-10-01

    Due to the ongoing discussion about the relevance of sleep studies performed in the laboratory, the aim of this study was to assess the effects of road traffic noise exposure on sleep in laboratory and in field settings. Eighteen healthy young subjects participated in the study. They were exposed to noise from road traffic in the laboratory and exposed to the same recorded traffic noise exposure in their own homes. Their sleep was evaluated with wrist actigraphs and questionnaires on sleep. No significant increase in effects of noise on sleep in the laboratory was found. The results indicate that laboratory experiments do not exaggerate effects of noise on sleep.

  8. Symposium: Noise-Induced Hearing Loss Held in Beaune, France on 28-30 May 1990.

    Science.gov (United States)

    1991-01-01

    animals were allowed to survive varying embryos . lie found that regenerated organs amounts of th,ie ranging from t day to 32 were numerically similar... embryo persist into adulthood or also produces complete loss of hair cells in any emerge from the damaged epithelium. part of the cochlea. Althotgh the...indices visucis destinis A influencer Iaprocessing computers designe’d for hearing- silection de Ia bande di6coute en activant Iaimpaired persona

  9. Noise-induced hearing loss induces loudness intolerance in a rat Active Sound Avoidance Paradigm (ASAP).

    Science.gov (United States)

    Manohar, Senthilvelan; Spoth, Jaclyn; Radziwon, Kelly; Auerbach, Benjamin D; Salvi, Richard

    2017-09-01

    Hyperacusis is a loudness hypersensitivity disorder in which moderate-intensity sounds are perceived as extremely loud, aversive and/or painful. To assess the aversive nature of sounds, we developed an Active Sound Avoidance Paradigm (ASAP) in which rats altered their place preference in a Light/Dark shuttle box in response to sound. When no sound (NS) was present, rats spent more than 95% of the time in the Dark Box versus the transparent Light Box. However, when a 60 or 90 dB SPL noise (2-20 kHz, 2-8 kHz, or 16-20 kHz bandwidth) was presented in the Dark Box, the rats'' preference for the Dark Box significantly decreased. Percent time in the dark decreased as sound intensity in the Dark Box increased from 60 dB to 90 dB SPL. Interestingly, the magnitude of the decrease was not a monotonic function of intensity for the 16-20 kHz noise and not related to the bandwidth of the 2-20 kHz and 2-8 kHz noise bands, suggesting that sound avoidance is not solely dependent on loudness but the aversive quality of the noise as well. Afterwards, we exposed the rats for 28 days to a 16-20 kHz noise at 102 dB SPL; this exposure produced a 30-40 dB permanent threshold shift at 16 and 32 kHz. Following the noise exposure, the rats were then retested on the ASAP paradigm. High-frequency hearing loss did not alter Dark Box preference in the no-sound condition. However, when the 2-20 kHz or 2-8 kHz noise was presented at 60 or 90 dB SPL, the rats avoided the Dark Box significantly more than they did before the exposure, indicating these two noise bands with energy below the region of hearing loss were perceived as more aversive. In contrast, when the 16-20 kHz noise was presented at 60 or 90 dB SPL, the rats remained in the Dark Box presumably because the high-frequency hearing loss made 16-20 kHz noise less audible and less aversive. These results indicate that when rats develop a high-frequency hearing loss, they become less tolerant of low frequency noise, i.e., high intensity sounds are perceived as more aversive and should be avoided. Published by Elsevier B.V.

  10. [The issue of medico-legal assessment of noise induced hearing loss: comparison of methods].

    Science.gov (United States)

    Bosio, D; Coggiola, M; Baracco, A; Andreis, P; Perrelli, F

    2011-01-01

    Audiogram classification is crucial for hearing protection of workers occupationally exposed to noise. The methods that have been proposed are based on two principles: the morphological evaluation of the audiometric curve (eg. Merluzzi-Pira-Bosio--MPB) or the average hearing loss on different frequencies (eg. Albera-Beatrice--AB). The purpose of this study was to classify audiograms compatible with chronic acoustic trauma performed at the Occupational Medicine Outpatient Clinic of CTO Hospital in Turin from 2004 to 2011 with the methods outlined in Guidelines published by SIMLII. A substantial agreement among the methods was observed. While MPB is the most appropriate method for secondary prevention, the AB would seem more appropriate for the verification of a permanent weakening that has to be reported to the competent legal authorities.

  11. Noise-induced multistability in chemical systems: Discrete versus continuum modeling

    Czech Academy of Sciences Publication Activity Database

    Duncan, A.; Liao, S.; Vejchodský, Tomáš; Erban, R.; Grima, R.

    2015-01-01

    Roč. 91, č. 4 (2015), s. 042111 ISSN 1539-3755 EU Projects: European Commission(XE) 328008 - STOCHDETBIOMODEL Institutional support: RVO:67985840 Keywords : chemical master equation * chemical Fokker-Planck equation * multimodality Subject RIV: BA - General Mathematics Impact factor: 2.288, year: 2014 http://journals.aps.org/pre/abstract/10.1103/PhysRevE.91.042111

  12. Noise-induced effects on multicellular biopacemaker spontaneous activity: Differences between weak and strong pacemaker cells

    Science.gov (United States)

    Aghighi, Alireza; Comtois, Philippe

    2017-09-01

    Self-organization of spontaneous activity of a network of active elements is important to the general theory of reaction-diffusion systems as well as for pacemaking activity to initiate beating of the heart. Monolayer cultures of neonatal rat ventricular myocytes, consisting of resting and pacemaker cells, exhibit spontaneous activation of their electrical activity. Similarly, one proposed approach to the development of biopacemakers as an alternative to electronic pacemakers for cardiac therapy is based on heterogeneous cardiac cells with resting and spontaneously beating phenotypes. However, the combined effect of pacemaker characteristics, density, and spatial distribution of the pacemaker cells on spontaneous activity is unknown. Using a simple stochastic pattern formation algorithm, we previously showed a clear nonlinear dependency of spontaneous activity (occurrence and amplitude of spontaneous period) on the spatial patterns of pacemaker cells. In this study, we show that this behavior is dependent on the pacemaker cell characteristics, with weaker pacemaker cells requiring higher density and larger clusters to sustain multicellular activity. These multicellular structures also demonstrated an increased sensitivity to voltage noise that favored spontaneous activity at lower density while increasing temporal variation in the period of activity. This information will help researchers overcome the current limitations of biopacemakers.

  13. Phase 2 Clinical Trials: D-Methionine to Reduce Noise-Induced Hearing Loss

    Science.gov (United States)

    2016-07-01

    Pharmaceuticals: Task completed. KP Pharmaceutical Technology, Indianapolis , Indiana is the drug manufacturer for this clinical trial. e. FDA/Regulatory...and Open House at Fort Jackson. j. June 8-9: Dr. Campbell interviewed with the Wall Street Journal at Fort Jackson. k. June 10-11, 2015: Dr...recommended by DoD Operational Medicine, Dr. Campbell, in conjunction with her business partner Jennifer Seibert, started a new biotech company, MetArmor

  14. Measurement of ground and nearby building vibration and noise induced by trains in a metro depot.

    Science.gov (United States)

    Zou, Chao; Wang, Yimin; Wang, Peng; Guo, Jixing

    2015-12-01

    Metro depots are where subway trains are parked and where maintenance is carried out. They usually occupy the largest ground areas in metro projects. Due to land utilization problems, Chinese cities have begun to develop over-track buildings above metro depots for people's life and work. The frequently moving trains, when going into and out of metro depots, can cause excessive vibration and noise to over-track buildings and adversely affect the living quality of the building occupants. Considering the current need of reliable experimental data for the construction of metro depots, field measurements of vibration and noise on the ground and inside a nearby 3-story building subjected to moving subway trains were conducted in a metro depot at Guangzhou, China. The amplitudes and frequency contents of velocity levels were quantified and compared. The composite A-weighted equivalent sound levels and maximum sound levels were captured. The predicted models for vibration and noise of metro depot were proposed based on existing models and verified. It was found that the vertical vibrations were significantly greater than the horizontal vibrations on the ground and inside the building near the testing line. While at the throat area, the horizontal vibrations near the curved track were remarkably greater than the vertical vibrations. The attenuation of the vibrations with frequencies above 50 Hz was larger than the ones below 50 Hz, and the frequencies of vibration transmitting to adjacent buildings were mainly within 10-50 Hz. The largest equivalent sound level generated in the throat area was smaller than the testing line one, but the instantaneous maximum sound level induced by wheels squeal, contact between wheels and rail joints as well as turnout was close to or even greater than the testing line one. The predicted models gave a first estimation for design and assessment of newly built metro depots. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Noise-induced synchronization, desynchronization, and clustering in globally coupled nonidentical oscillators

    KAUST Repository

    Lai, Yi Ming

    2013-07-09

    We study ensembles of globally coupled, nonidentical phase oscillators subject to correlated noise, and we identify several important factors that cause noise and coupling to synchronize or desynchronize a system. By introducing noise in various ways, we find an estimate for the onset of synchrony of a system in terms of the coupling strength, noise strength, and width of the frequency distribution of its natural oscillations. We also demonstrate that noise alone can be sufficient to synchronize nonidentical oscillators. However, this synchrony depends on the first Fourier mode of a phase-sensitivity function, through which we introduce common noise into the system. We show that higher Fourier modes can cause desynchronization due to clustering effects, and that this can reinforce clustering caused by different forms of coupling. Finally, we discuss the effects of noise on an ensemble in which antiferromagnetic coupling causes oscillators to form two clusters in the absence of noise. © 2013 American Physical Society.

  16. Lévy-noise-induced transport in a rough triple-well potential.

    Science.gov (United States)

    Li, Yongge; Xu, Yong; Kurths, Jürgen; Yue, Xiaole

    2016-10-01

    Rough energy landscape and noisy environment are two common features in many subjects, such as protein folding. Due to the wide findings of bursting or spiking phenomenon in biology science, small diffusions mixing large jumps are adopted to model the noisy environment that can be properly described by Lévy noise. We combine the Lévy noise with the rough energy landscape, modeled by a potential function superimposed by a fast oscillating function, and study the transport of a particle in a rough triple-well potential excited by Lévy noise, rather than only small perturbations. The probabilities of a particle staying in the middle well are considered under different amplitudes of roughness to find out how roughness affects the steady-state probability density function. Variations in the mean first passage time from the middle well to the right well have been investigated with respect to Lévy parameters and amplitudes of the roughness. In addition, we have examined the influences of roughness on the splitting probabilities of the first escape from the middle well. We uncover that the roughness can enhance significantly the first escape of a particle from the middle well, especially for different skewness parameters, but weak differences are found for stability index and noise intensity on the probabilities a particle staying in the middle well and splitting probability to the right.

  17. The state of the art of predicting noise-induced sleep disturbance in field settings

    OpenAIRE

    Sanford Fidell; Barbara Tabachnick; Karl S Pearsons

    2010-01-01

    Several relationships between intruding noises (largely aircraft) and sleep disturbance have been inferred from the findings of a handful of field studies. Comparisons of sleep disturbance rates predicted by the various relationships are complicated by inconsistent data collection methods and definitions of predictor variables and predicted quantities. None of the relationships is grounded in theory-based understanding, and some depend on questionable statistical assumptions and analysis proc...

  18. Noise-Induced Transition in a Voltage-Controlled Oscillator Neuron Model

    International Nuclear Information System (INIS)

    Xie Huizhang; Liu Xuemei; Li Zhibing; Ai Baoquan; Liu Lianggang

    2008-01-01

    In the presence of Gaussian white noise, we study the properties of voltage-controlled oscillator neuron model and discuss the effects of the additive and multiplicative noise. It is found that the additive noise can accelerate and counterwork the firing of neuron, which depends on the value of central frequency of neuron itself, while multiplicative noise can induce the continuous change or mutation of membrane potential

  19. Dichotomous-noise-induced pattern formation in a reaction-diffusion system

    Science.gov (United States)

    Das, Debojyoti; Ray, Deb Shankar

    2013-06-01

    We consider a generic reaction-diffusion system in which one of the parameters is subjected to dichotomous noise by controlling the flow of one of the reacting species in a continuous-flow-stirred-tank reactor (CSTR) -membrane reactor. The linear stability analysis in an extended phase space is carried out by invoking Furutzu-Novikov procedure for exponentially correlated multiplicative noise to derive the instability condition in the plane of the noise parameters (correlation time and strength of the noise). We demonstrate that depending on the correlation time an optimal strength of noise governs the self-organization. Our theoretical analysis is corroborated by numerical simulations on pattern formation in a chlorine-dioxide-iodine-malonic acid reaction-diffusion system.

  20. Measuring neutron noise induced by travelling air bubbles in a research reactor

    International Nuclear Information System (INIS)

    Por, G.; Horanyi, S.

    1983-05-01

    Travelling air bubble experiments carried out in a research reactor confirm an earlier proposed model. The sink structure could be found experimentally in APSD of neutron signals and was used to determine the bubble velocity. The measurements show that neutron detectors measure the velocity of the travelling bubbles, the thermocouples that of the water flow. (author)

  1. Sex Difference in Susceptibility and Resistance to Noise-Induced Hearing Loss in Chinchillas

    Science.gov (United States)

    2000-10-01

    1994) Influence of intracellular glutathione concentration of lipofuscin accumulation in cultured neonatal rat cardiac myocytes. Free Rad Biol...0 - s o nA= £& 0. -10 - y$*%sf^ Q -20 - 1k c;n i i > i 40 - i a. 30 - JS. V3 CO 20 - rcP DU /cr 2, 10 - A* in /Jfr < 0...Liberman, M.C. (1998) Long- term effects of sectioning the olivocochlear bundle in neonatal cats. Journal ofNeuroscienceW, 3859-3869. 23. Zheng, X.Y

  2. Noise-induced drift in systems with broken symmetry and classical routes to superconductivity

    International Nuclear Information System (INIS)

    Shapiro, V.E.

    1994-01-01

    We discuss concepts and mechanisms of particle motion in a variety of conditions of asymmetry towards spatial inversion that suggest an idea for the possibility of persistent currents within classical statistical considerations. We expose misapplications of Gibbs statistics and the Langevin approach and show that the idea does not contradict general principles. It gains support from the classical mechanism of capillary wave instability and keeps within the detailed balance and fluctuation-dissipation theorems. (author). 7 refs., 2 figs

  3. Noise-induced hearing loss prevention in the South African mining industry

    CSIR Research Space (South Africa)

    Edwards, A

    2010-08-01

    Full Text Available ftb oss En gin eer ign as sis tan t Fir st a id W ork er Ba nks ma n En vir on me nta l Offi cer Sha ft F ore ma n Ch an geh ou se Cle rk Gold mining occupations L ae q (d BA ) © CSIR 2010 Slide 12 Results... l le ad er Oc cup ati on al Tra cer Opencast coal occupations L ae q (d BA ) © CSIR 2010 Slide 13 Results Noise exposure levels in underground coal occupations 60 65 70 75 80 85 90 95 100 105 Co nti nu os mi ne r...

  4. Preliminary Mathematical Model for Jet Fuel Exacerbated Noise-Induced Hearing Loss

    Science.gov (United States)

    2013-01-01

    pharmacokinetics of gasoline using PBPK modeling with a complex mixtures chemical lumping approach. Inhal . Toxicol. 15:961-986. Dennison, J. E., Andersen, M. E...loss in Long-Evans rats. JP-8 nose-only inhalation exposures were 1000 mg/m3 for 4 hours on 1 or 5 days, immediately followed by 97, 102 or 105 dB... inhalation of 1000 mg/m3 for 4 hours. 2.1 Objective For the project herein, the working hypothesis is that free radical generation and

  5. Application of the Lyapunov exponent to detect noise-induced chaos in oscillating microbial cultures

    International Nuclear Information System (INIS)

    Patnaik, P.R.

    2005-01-01

    Oscillating microbial processes can, under certain conditions, gravitate into chaotic behavior induced by external noise. Detection and control of chaos are important for the survival of the microorganisms and to operate a process usefully. In this study the largest Lyapunov exponent is recommended as a convenient and reliable index of chaos in continuous oscillating cultures. For the growth of Saccharomyces cerevisiae as a model system, the exponents increase with the oxygen mass transfer coefficient and decrease as the dilution rate increases. By comparing with the corresponding time-domain oscillations determined earlier, it is inferred that weakly oscillating cultures are less likely to be driven to chaotic behavior. The main carbon source, glucose, is quite robust to chaotic destabilization, thus enhancing its suitability as a manipulated variable for bioreactor control

  6. Jet Fuel Exacerbated Noise-Induced Hearing Loss: Focus on Prediction of Central Auditory Processing Dysfunction

    Science.gov (United States)

    2017-09-01

    standard deviation). 4.3.3 Lipid Class Determination for Partition Coefficient Prediction. Research was conducted on methods to quantify...Advancement of Military Medicine Aeromedical Research Department United States Air Force School of Aerospace Medicine Wright-Patterson AFB OH...Report for Oct 2015 to Mar 2017 Air Force Research Laboratory 711th Human Performance Wing Airman Systems Directorate Bioeffects Division

  7. Noise-induced coherence in bistable systems with multiple time delays

    International Nuclear Information System (INIS)

    Jiang Yu; Dong, Shi-Hai; Lozada-Cassou, M.

    2004-01-01

    We study the correlation properties of noise-driven bistable systems with multiple time-delay feedbacks. For small noisy perturbation and feedback magnitude, we derive the autocorrelation function and the power spectrum based on the two-state model with transition rates depending on the earlier states of the system. A comparison between the single and double time delays reveals that the auto correlation functions exhibit exponential decay with small undulation for the double time delays, in contrast with the remarkable oscillatory behavior at small time lags for the single time delay

  8. The effect of loss of immunity on noise-induced sustained oscillations in epidemics.

    Science.gov (United States)

    Chaffee, J; Kuske, R

    2011-11-01

    The effect of loss of immunity on sustained population oscillations about an endemic equilibrium is studied via a multiple scales analysis of a SIRS model. The analysis captures the key elements supporting the nearly regular oscillations of the infected and susceptible populations, namely, the interaction of the deterministic and stochastic dynamics together with the separation of time scales of the damping and the period of these oscillations. The derivation of a nonlinear stochastic amplitude equation describing the envelope of the oscillations yields two criteria providing explicit parameter ranges where they can be observed. These conditions are similar to those found for other applications in the context of coherence resonance, in which noise drives nearly regular oscillations in a system that is quiescent without noise. In this context the criteria indicate how loss of immunity and other factors can lead to a significant increase in the parameter range for prevalence of the sustained oscillations, without any external driving forces. Comparison of the power spectral densities of the full model and the approximation confirms that the multiple scales analysis captures nonlinear features of the oscillations.

  9. Impacts of clustering on noise-induced spiking regularity in the excitatory neuronal networks of subnetworks.

    Science.gov (United States)

    Li, Huiyan; Sun, Xiaojuan; Xiao, Jinghua

    2015-01-01

    In this paper, we investigate how clustering factors influent spiking regularity of the neuronal network of subnetworks. In order to do so, we fix the averaged coupling probability and the averaged coupling strength, and take the cluster number M, the ratio of intra-connection probability and inter-connection probability R, the ratio of intra-coupling strength and inter-coupling strength S as controlled parameters. With the obtained simulation results, we find that spiking regularity of the neuronal networks has little variations with changing of R and S when M is fixed. However, cluster number M could reduce the spiking regularity to low level when the uniform neuronal network's spiking regularity is at high level. Combined the obtained results, we can see that clustering factors have little influences on the spiking regularity when the entire energy is fixed, which could be controlled by the averaged coupling strength and the averaged connection probability.

  10. Analysis of impact noise induced by hitting of titanium head golf driver.

    Science.gov (United States)

    Kim, Young Ho; Kim, Young Chul; Lee, Jun Hee; An, Yong-Hwi; Park, Kyung Tae; Kang, Kyung Min; Kang, Yeon June

    2014-11-01

    The hitting of titanium head golf driver against golf ball creates a short duration, high frequency impact noise. We analyzed the spectra of these impact noises and evaluated the auditory hazards from exposure to the noises. Noises made by 10 titanium head golf drivers with five maximum hits were collected, and the spectra of the pure impact sounds were studied using a noise analysis program. The noise was measured at 1.7 m (position A) and 3.4 m (position B) from the hitting point in front of the hitter and at 3.4 m (position C) behind the hitting point. Average time duration was measured and auditory risk units (ARUs) at position A were calculated using the Auditory Hazard Assessment Algorithm for Humans. The average peak levels at position A were 119.9 dBA at the sound pressure level (SPL) peak and 100.0 dBA at the overall octave level. The average peak levels (SPL and overall octave level) at position B were 111.6 and 96.5 dBA, respectively, and at position C were 111.5 and 96.7 dBA, respectively. The average time duration and ARUs measured at position A were 120.6 ms and 194.9 units, respectively. Although impact noises made by titanium head golf drivers showed relatively low ARUs, individuals enjoying golf frequently may be susceptible to hearing loss due to the repeated exposure of this intense impact noise with short duration and high frequency. Unprotected exposure to impact noises should be limited to prevent cochleovestibular disorders.

  11. Addendum to "Colored-noise-induced discontinuous transitions in symbiotic ecosystems".

    Science.gov (United States)

    Sauga, Ako; Mankin, Romi

    2005-06-01

    A symbiotic ecosystem with Gompertz self-regulation and with adaptive competition between populations is studied by means of a N-species Lotka-Volterra stochastic model. The influence of fluctuating environment on the carrying capacity of a population is modeled as a dichotomous noise. The study is a follow up of previous investigations of symbiotic ecosystems subjected to the generalized Verhulst self-regulation [Phys. Rev. E 69, 061106 (2004); 65, 051108 (2002)]. In the framework of mean-field approximation the behavior of the solutions of the self-consistency equation for a stationary system is examined analytically in the full phase space of system parameters. Depending on the mutual interplay of symbiosis and competition of species, variation of noise parameters (amplitude, correlation time) can induce doubly unidirectional discontinuous transitions as well as single unidirectional discontinuous transitions of the mean population size.

  12. Addendum to ``Colored-noise-induced discontinuous transitions in symbiotic ecosystems''

    Science.gov (United States)

    Sauga, Ako; Mankin, Romi

    2005-06-01

    A symbiotic ecosystem with Gompertz self-regulation and with adaptive competition between populations is studied by means of a N -species Lotka-Volterra stochastic model. The influence of fluctuating environment on the carrying capacity of a population is modeled as a dichotomous noise. The study is a follow up of previous investigations of symbiotic ecosystems subjected to the generalized Verhulst self-regulation [Phys. Rev. E 69, 061106 (2004); 65, 051108 (2002)]. In the framework of mean-field approximation the behavior of the solutions of the self-consistency equation for a stationary system is examined analytically in the full phase space of system parameters. Depending on the mutual interplay of symbiosis and competition of species, variation of noise parameters (amplitude, correlation time) can induce doubly unidirectional discontinuous transitions as well as single unidirectional discontinuous transitions of the mean population size.

  13. Interventions to prevent occupational noise-induced hearing loss: A Cochrane systematic review

    Science.gov (United States)

    Verbeek, Jos H.; Kateman, Erik; Morata, Thais C.; Dreschler, Wouter A.; Mischke, Christina

    2015-01-01

    Objective To assess the effectiveness of interventions for preventing occupational noise exposure or hearing loss compared to no intervention or alternative interventions. Design We searched biomedical databases up to 25 January 2012 for randomized controlled trials (RCT), controlled before-after studies and interrupted time-series of hearing loss prevention among workers exposed to noise. Study sample We included 19 studies with 82 794 participants evaluating effects of hearing loss prevention programs (HLPP). The overall quality of studies was low to very low, as rated using the GRADE approach. Results One study of stricter legislation showed a favorable effect on noise levels. Three studies, of which two RCTs, did not find an effect of a HLPP. Four studies showed that better use of hearing protection devices in HLPPs decreased the risk of hearing loss. In four other studies, workers in a HLPP still had a 0.5 dB greater hearing loss at 4 kHz (95% CI – 0.5 to 1.7) than non-exposed workers. In two similar studies there was a substantial risk of hearing loss in spite of a HLPP. Conclusions Stricter enforcement of legislation and better implementation of HLPPs can reduce noise levels in workplaces. Better evaluations of technical interventions and long-term effects are needed. PMID:24564697

  14. Noise induced hearing loss and other hearing complaints among musicians of symphony orchestras

    NARCIS (Netherlands)

    Jansen, E. J. M.; Helleman, H. W.; Dreschler, W. A.; de Laat, J. A. P. M.

    2009-01-01

    OBJECTIVES: An investigation of the hearing status of musicians of professional symphony orchestras. Main questions are: (1) Should musicians be treated as a special group with regard to hearing, noise, and noise related hearing problems (2) Do patterns of hearing damage differ for different

  15. A retrospective analysis of noise-induced hearing loss in the Dutch construction industry

    NARCIS (Netherlands)

    Leensen, M. C. J.; Van Duivenbooden, J. C.; Dreschler, W. A.

    2011-01-01

    Purpose Noise exposure is an important and highly prevalent occupational hazard in the construction industry. This study examines hearing threshold levels of a large population of Dutch construction workers and compares their hearing thresholds to those predicted by ISO-1999. Methods In this

  16. Interventions to prevent occupational noise-induced hearing loss: a Cochrane systematic review

    NARCIS (Netherlands)

    Verbeek, Jos H.; Kateman, Erik; Morata, Thais C.; Dreschler, Wouter A.; Mischke, Christina

    2014-01-01

    To assess the effectiveness of interventions for preventing occupational noise exposure or hearing loss compared to no intervention or alternative interventions. We searched biomedical databases up to 25 January 2012 for randomized controlled trials (RCT), controlled before-after studies and

  17. Reduction of background noise induced by wind tunnel jet exit vanes

    Science.gov (United States)

    Martin, R. M.; Brooks, T. F.; Hoad, D. R.

    1985-01-01

    The NASA-Langley 4 x 7 m wind tunnel develops low frequency flow pulsations at certain velocity ranges during open throat mode operation, affecting the aerodynamics of the flow and degrading the resulting model test data. Triangular vanes attached to the trailing edge of flat steel rails, mounted 10 cm from the inside of the jet exit walls, have been used to reduce this effect; attention is presently given to methods used to reduce the inherent noise generation of the vanes while retaining their pulsation reduction features.

  18. Phase 3 Clinical Trials: D-Methionine to Reduce Noise-Induced Hearing Loss

    Science.gov (United States)

    2013-03-01

    tympanometry, and pure-tone hearing threshold testing at .5, 1, 2, 3, 4, 6, 8 kHz bilaterally. Tinnitus will be measured using standardized ...chemistry, and urinalysis ) on all study participants. The purpose of these recommendations were 1) to exclude participants with mild renal impairment until...analysis and urinalysis for the study participants to the study protocol. Therefore, during the third quarter, no additions were made to the original

  19. Noise induced multidecadal variability in the North Atlantic: excitation of normal modes

    NARCIS (Netherlands)

    Frankcombe, L.M.; Dijkstra, H.A.; von der Heydt, A.S.

    2009-01-01

    In this paper it is proposed that the stochastic excitation of a multidecadal internal ocean mode is at the origin of the multidecadal sea surface temperature variability in the North Atlantic. The excitation processes of the spatial sea surface temperature pattern associated with this multidecadal

  20. The prevalence of noise-induced occupational hearing loss in dentistry personnel.

    Science.gov (United States)

    Khaimook, Wandee; Suksamae, Puwanai; Choosong, Thitiworn; Chayarpham, Satit; Tantisarasart, Ratchada

    2014-09-01

    Occupational hearing loss is the second most common health problem in the industrialized world. Dental personnel exposed to occupational noise may experience hearing loss. This article compares the prevalence of hearing loss in the general population to that of dental personnel exposed to noise during work hours and identifies risk factors for hearing loss among workers at a dental school. This prospective study included 76 dental personnel on the faculty of dentistry at a major university in Asia who were exposed to noise and 76 individuals in a control group. Nearly 16% of the study group and 21% of the control group had lost hearing, a nonsignificant difference (p = .09). Hearing loss was significantly related to work tenure longer than 15 years and age older than 40 years (p < .001 ).

  1. Interventions to prevent occupational noise-induced hearing loss: a Cochrane systematic review.

    Science.gov (United States)

    Verbeek, Jos H; Kateman, Erik; Morata, Thais C; Dreschler, Wouter A; Mischke, Christina

    2014-03-01

    To assess the effectiveness of interventions for preventing occupational noise exposure or hearing loss compared to no intervention or alternative interventions. We searched biomedical databases up to 25 January 2012 for randomized controlled trials (RCT), controlled before-after studies and interrupted time-series of hearing loss prevention among workers exposed to noise. We included 19 studies with 82 794 participants evaluating effects of hearing loss prevention programs (HLPP). The overall quality of studies was low to very low, as rated using the GRADE approach. One study of stricter legislation showed a favorable effect on noise levels. Three studies, of which two RCTs, did not find an effect of a HLPP. Four studies showed that better use of hearing protection devices in HLPPs decreased the risk of hearing loss. In four other studies, workers in a HLPP still had a 0.5 dB greater hearing loss at 4 kHz (95% CI - 0.5 to 1.7) than non-exposed workers. In two similar studies there was a substantial risk of hearing loss in spite of a HLPP. Stricter enforcement of legislation and better implementation of HLPPs can reduce noise levels in workplaces. Better evaluations of technical interventions and long-term effects are needed.

  2. Noise-induced multistability in chemical systems: Discrete versus continuum modeling

    Czech Academy of Sciences Publication Activity Database

    Duncan, A.; Liao, S.; Vejchodský, Tomáš; Erban, R.; Grima, R.

    2015-01-01

    Roč. 91, č. 4 (2015), s. 042111 ISSN 1539-3755 EU Projects: European Commission(XE) 328008 - STOCHDETBIOMODEL Institutional support: RVO:67985840 Keywords : chemical master equation * chemical Fokker-Planck equation * multimodality Subject RIV: BA - General Mathematics Impact factor: 2.288, year: 2014 http://journals. aps .org/pre/abstract/10.1103/PhysRevE.91.042111

  3. Noise-induced synchronization, desynchronization, and clustering in globally coupled nonidentical oscillators

    KAUST Repository

    Lai, Yi Ming; Porter, Mason A.

    2013-01-01

    to synchronize nonidentical oscillators. However, this synchrony depends on the first Fourier mode of a phase-sensitivity function, through which we introduce common noise into the system. We show that higher Fourier modes can cause desynchronization due

  4. Hearing Preservation Electrodes in Veterans and Military Service members with Noise-Induced Hearing Loss

    Science.gov (United States)

    2016-07-01

    support the emotional message of a film (e.g., scary music in horror films , up-beat happy music for comedies, etc.). Prior research indicates that...people listen to music is because music is associated with mood and emotion. Consider, for example, how music is used as background for films to

  5. Noise-induced attractor annihilation in the delayed feedback logistic map

    International Nuclear Information System (INIS)

    Pisarchik, A.N.; Martínez-Zérega, B.E.

    2013-01-01

    We study dynamics of the bistable logistic map with delayed feedback, under the influence of white Gaussian noise and periodic modulation applied to the variable. This system may serve as a model to describe population dynamics under finite resources in noisy environment with seasonal fluctuations. While a very small amount of noise has no effect on the global structure of the coexisting attractors in phase space, an intermediate noise totally eliminates one of the attractors. Slow periodic modulation enhances the attractor annihilation.

  6. Adaptation to Cortical Noise Induced by Transcranial Magnetic Stimulation to the Occipital Lobe

    Directory of Open Access Journals (Sweden)

    David Heslip

    2012-05-01

    Full Text Available Transcranial magnetic stimulation (TMS is increasingly used as a method to modify and study functional brain activity. However, results from various studies have produced conflicting theories on how TMS of cortical tissue influences ongoing visual processing. To investigate this issue, single pulse TMS was applied over left V1 in five healthy subjects during an orientation discrimination task (vertical vs. horizontal using a Gabor patch (2 c/deg, presented 6° in the right visual field. Stimulus contrast was set to each individual's threshold, measured in the absence of TMS. When TMS was applied over V1 performance decreased in all observers (by 1.2–8.7% compared to accuracy levels obtained during stimulation of a control site (Cz. Crucially, accuracy levels during V1 stimulation gradually improved across blocks of 200 trials in some subjects, whereas performance remained stable during control site stimulation. In contrast, this pattern of recovery was not found in an analogous backward masking paradigm, using a brief visual noise mask instead of a TMS pulse. These results show that that the magnitude of TMS disruption can dissipate with repeated stimulation. This suggests that future studies using this technique should minimise the length of TMS exposure within each session to maximise its effectiveness. Our results show that the visual system can adapt dynamically to increased internal noise levels, minimising the impact of TMS induced cortical activity on sensory judgments.

  7. Assessment Of Noise-induced Sleep Fragility In Two Age Ranges By Means Of Polysomnographic Microstructure

    Science.gov (United States)

    Terzano, M. G.; Parrino, L.; Spaggiari, M. C.; Buccino, G. P.; Fioriti, G.; Depoortere, H.

    1993-04-01

    The microstructure of sleep, which translates the short-lived fluctuations of the arousal level, is a commonly neglected feature in polysomnographic studies. Specifically arranged microstructural EEG events may provide important information on the dynamic characteristics of the sleep process. CAP (cyclic alternating pattern) and non-CAP are complementary modalities in which arousal-related "phasic" EEG phenomena are organized in non-REM sleep, and they correspond to opposite conditions of unstable and stable sleep depth, respectively. Thus, arousal instability can be measured by the CAP rate, the percentage ratio of total CAP time to total non-REM sleep time. The CAP rate, an age-related physiological variable that increases in several pathological conditions, is highly sensitive to acoustic perturbation. In the present study, two groups of healthy subjects without complaints about sleep, belonging to different age ranges (six young adults, three males and three females, between 20 and 30 years, and six middle-aged individuals, three males and three females, between 40 and 55 years) slept, after adaptation to the sleep laboratory, in a random sequence for two non-consecutive nights either under silent baseline (27·3 dB(A) Lcq) or noise-disturbed (continuous 55 dB(A) white noise) conditions. Age-related and noise-related effects on traditional sleep parameters and on the CAP rate were statistically evaluated by a split-plot test. Compared to young adults, the middle-aged individuals showed a significant reduction of total sleep time, stage 2 and REM sleep and significantly higher values of nocturnal awakenings and the CAP rate. The noisy nights were characterized by similar alterations. The disruptive effects of acoustic perturbation were greater on the more fragile sleep architecture of the older group. The increased fragility of sleep associated with aging probably reflects the decreased capacity of the sleeping brain to maintain steady states of vigilance. Total non-REM sleep described by traditional parameters was statistically unaffected during the disturbed nights, but the perturbing effects of noise on non-REM sleep stability and continuity were revealed by a significant increase in the CAP rate. The perspectives for a wide-ranging exploitation of this sleep parameter are discussed.

  8. Environmental Factors Having an Impact on the Noise Induced by Motor Vahicles

    Directory of Open Access Journals (Sweden)

    Rasa Akelaitytė

    2013-12-01

    Full Text Available The transport sector is rapidly developing industry in Lithuania. Over the past few years, a significant increase in motor vehicles on our roads can be noticed. Both light and heavy vehicles create economic benefits, and, at the same time, cause ecological and social problems such as noise, a growing number of accidents and environmental pollution. In order to reduce the rate of accidents, many places have been equipped with speed-limiting humps. However, the vehicles approaching them will increase noise levels. The article describes a calculation method of how to determine the influence of various factors caused by car noise. Reflections on the surface, the atmosphere and sound waves on road obstacles can increase or decrease sounds in the environment. The above introduced factors must be taken into account conducting noise measurement tests.Article in Lithuanian

  9. Noise Induced Dissipation in Discrete-Time Classical and Quantum Dynamical Systems

    OpenAIRE

    Wolowski, Lech

    2004-01-01

    We introduce a new characteristics of chaoticity of classical and quantum dynamical systems by defining the notion of the dissipation time which enables us to test how the system responds to the noise and in particular to measure the speed at which an initially closed, conservative system converges to the equilibrium when subjected to noisy (stochastic) perturbations. We prove fast dissipation result for classical Anosov systems and ...

  10. The Risk of Noise-Induced Hearing Loss During Simulated Dives in Canadian Forces Hyperbaric Facilities

    Science.gov (United States)

    2012-10-01

    développement, à l’ingénierie et aux évaluations (STO/DEE) formulée par le SMA (Mat) relativement à la collecte de données sur le risque de perte...l’ingénierie et aux évaluations (STO/DEE) formulée par le SMA (Mat) relativement à la collecte de données sur le risque de perte auditive due au bruit chez...Selection of human participants The protocol was approved in advance by the Human Research Ethics Committee of Defence Research and Development Canada

  11. Stress and personality.

    Science.gov (United States)

    Lecic-Tosevski, D; Vukovic, O; Stepanovic, J

    2011-01-01

    Stress is an adaptation reaction of living organisms in response to internal or external threats to homeostasis. It is considered as a complex defence mechanism representing the final endpoint of numerous dynamic and interconnected factors of biological, psychological and social nature. Stress is not a simple, stimulus-response reaction, but the interaction between an individual and the environment, involving subjective perception and assessment of stressors, thus constituting a highly personalized process. Specific inherited characteristics, early experience in life, and particular, learned cognitive predispositions make individuals more or less susceptible to the effects of stressors. Resilience and vulnerability to stressors as well as intensity of stress response are greatly dependable on age, gender, intelligence, and numerous characteristics of personality, such as hardiness,locus of control, self-efficacy, self-esteem, optimism, hostility (component of type A personality)and type D traits (negative affectivity and social inhibition). To understand the relation between personality and stress, it is essential to recognize the impact of individual differences in the following four aspects: (1) choice or avoidance of environments that are associated with specific stressors, challenges or benefits, (2) way of interpreting a stressful situation and evaluating one's own abilities and capacities for proactive behaviour so as to confront or avoid it, (3) intensity of response to a stressor,and (4) coping strategies employed by the individual facing a stressful situation. Studies have recorded considerable consistency in coping strategies employed to confront stressful situations, independentlyof situational factors and in connection with permanent personality and temperamental traits,such as neuroticism, extraversion, sense of humour, persistence, fatalism, conscientiousness, andopenness to experience. Positive affect has been associated with positive reappraisal

  12. to salt stress

    African Journals Online (AJOL)

    Tony

    2012-02-14

    Feb 14, 2012 ... 3Inner Mongolia Industrial Engineering Research, Center of University for Castor, Tongliao 028042, ... strengthen and improve salt stress tolerance in plants. .... 2 µl cDNA, 1 µl each of 4 µM forward and reverse primer, 0.2 µl.

  13. Thermal Stresses in Welding

    DEFF Research Database (Denmark)

    Hansen, Jan Langkjær

    1998-01-01

    Studies of the transient temperature fields and the hereby induced deformations and stressses in a butt-welded mild steel plate modelledrespectively in 2D plane stress state (as well as plane strain state) and in full 3D have been done. The model has been implemented in the generalpurpose FE...

  14. Psychological Stress and Cancer

    Science.gov (United States)

    ... on or fail to adhere to potentially helpful therapy, engage in risky behaviors such as drug use, or do not maintain a healthy lifestyle, resulting in premature death. How can people who have cancer learn to cope with psychological stress? Emotional and social support can help patients ...

  15. Stress og Socialitet

    DEFF Research Database (Denmark)

    Strøbæk, Pernille Solveig

    2009-01-01

    Ifølge de etablerede arbejdsstressteorier skal miljømæssige krav balanceres op imod individuelle kontrolmuligheder, og der peges derfor på behovet for både sociologiske og psykologiske niveauer af arbejdsstress. Selvom en niveauinddelt tilgang til stress er vigtig, risikeres en opsplitning mellem...

  16. Warm pre-stressing

    International Nuclear Information System (INIS)

    Hedner, G.

    1983-01-01

    Literature survey and critical evaluation of the phenomenon of warm pre-stressing (WPS) is presented. It is found that the cause of it is not clear and a calculated control is missing. The effect of irradiation is unknown, and the influence of WPS on the behaviour of reactor vessels is discussed. (G.B.)

  17. Stress in medical students.

    Science.gov (United States)

    Nechita, Florina; Nechita, Dan; Pîrlog, Mihail Cristian; Rogoveanu, Ion

    2014-01-01

    Stress has been defined as the state of a body threatened by imbalance under the influence of agents or conditions endangering its homeostatic mechanisms but the concept have multiple meanings in correlation with the origin and biological support of its effects. Also, stressors are multiple, recording one of the highest levels during the academic studies. For the medical students, stress represents an important challenge, especially during the first year of medical school, caused by the absence of a learning strategy, the sleepless night before the exam and also an unhealthy food intake during the exams. The coping strategies are important, their background being represented by the social support, especially within the family, and emotional, the passions of the medicine students being the most important stress-combating factor. Gender represents also an important factor for the stress vulnerability, manifested through medical and psychiatric symptoms. In order to train good doctors, fair and above all healthy, it is important to consider not only the information we want to transmit, but also the context in which we educate.

  18. The stress of registrarship

    African Journals Online (AJOL)

    previous non-registrarship years happier and to believe that the following year would not be a happy one. Fewer registrars who engaged in 'moonlighting', compared to 'non- moonlighters', found it a happy year generally, but the difference was not significant (P =0,081). • .' Sources of stress. During registrarship, the trainee ...

  19. [Vitamins and oxidative stress].

    Science.gov (United States)

    Kodentsova, V M; Vrzhesinskaia, O A; Mazo, V K

    2013-01-01

    The central and local stress limiting systems, including the antioxidant defense system involved in defending the organism at the cellular and systemic levels from excess activation response to stress influence, leading to damaging effects. The development of stress, regardless of its nature [cold, increased physical activity, aging, the development of many pathologies (cardiovascular, neurodegenerative diseases, diseases of the gastrointestinal tract, ischemia, the effects of burns), immobilization, hypobaric hypoxia, hyperoxia, radiation effects etc.] leads to a deterioration of the vitamin status (vitamins E, A, C). Damaging effect on the antioxidant defense system is more pronounced compared to the stress response in animals with an isolated deficiency of vitamins C, A, E, B1 or B6 and the combined vitamins deficiency in the diet. Addition missing vitamin or vitamins restores the performance of antioxidant system. Thus, the role of vitamins in adaptation to stressors is evident. However, vitamins C, E and beta-carotene in high doses, significantly higher than the physiological needs of the organism, may be not only antioxidants, but may have also prooxidant properties. Perhaps this explains the lack of positive effects of antioxidant vitamins used in extreme doses for a long time described in some publications. There is no doubt that to justify the current optimal doses of antioxidant vitamins and other dietary antioxidants specially-designed studies, including biochemical testing of initial vitamin and antioxidant status of the organism, as well as monitoring their change over time are required.

  20. Stress and Child Development

    Science.gov (United States)

    Thompson, Ross A.

    2014-01-01

    Children's early social experiences shape their developing neurological and biological systems for good or for ill, writes Ross Thompson, and the kinds of stressful experiences that are endemic to families living in poverty can alter children's neurobiology in ways that undermine their health, their social competence, and their ability…