WorldWideScience

Sample records for space motion sickness

  1. Comparison of treatment strategies for Space Motion Sickness

    Science.gov (United States)

    Davis, J. R.; Jennings, R. T.; Beck, B. G.

    1992-01-01

    Treatment strategies for Space Motion Sickness were compared using the results of postflight oral debriefings. Standardized questionnaires were administered to all crewmembers immediately following Space Shuttle flights by NASA flight surgeons. Cases of Space Motion Sickness were graded as mild, moderate or severe based on published criteria, and medication effectiveness was judged based on subjective reports of symptom relief. Since October 1989, medication effectiveness is reported inflight through Private Medical Conferences with the crew. A symptom matrix was analyzed for 19 crewmembers treated with an oral combination of scopolamine and dextroamphetamine (scopdex) and 15 crewmembers treated with promethazine delivered by intramuscular (IM) or suppository routes. Scopdex has been given preflight as prophaxis for Space Motion Sickness but analysis showed delayed symptom presentation in 9 crewmembers or failed to prevent symptoms in 7. Only three crewmembers who took scopdex had no symptoms inflight. Fourteen out of 15 crewmembers treated with IM promethazine and 6 of 8 treated with promethazine suppositories after symptom development had immediate (within 12 h) symptom relief and required no additional medication. There were no cases of delayed symptom presentation in the crewmembers treated with promethazine. This response is in contrast to untreated crewmembers who typically have slow symptom resolution over 72-96 h. We conclude that promethazine is an effective treatment of Space Motion Sickness symptoms inflight. NASA policy currently recommends treating crewmembers with Space Motion Sickness after symptom development, and no longer recommends prophylaxis with scopdex due to delayed symptom development and apparent variable absorption of oral medications during early flight days.

  2. Autogenic feedback training experiment: A preventative method for space motion sickness

    Science.gov (United States)

    Cowings, Patricia S.

    1993-01-01

    Space motion sickness is a disorder which produces symptoms similar to those of motion sickness on Earth. This syndrome has affected approximately 50 percent of all astronauts and cosmonauts exposed to microgravity in space, but it differs from what is commonly known as motion sickness in a number of critical ways. There is currently no ground-based method for predicting susceptibility to motion sickness in space. Antimotion sickness drugs have had limited success in preventing or counteracting symptoms in space, and frequently caused debilitating side effects. The objectives were: (1) to evaluate the effectiveness of Autogenic-Feedback Training as a countermeasure for space motion sickness; (2) to compare physiological data and in-flight symptom reports to ground-based motion sickness data; and (3) to predict susceptibility to space motion sickness based on pre-flight data of each treatment group crew member.

  3. Subjective Vertical Conflict Theory and Space Motion Sickness.

    Science.gov (United States)

    Chen, Wei; Chao, Jian-Gang; Wang, Jin-Kun; Chen, Xue-Wen; Tan, Cheng

    2016-02-01

    Space motion sickness (SMS) remains a troublesome problem during spaceflight. The subjective vertical (SV) conflict theory postulates that all motion sickness provoking situations are characterized by a condition in which the SV sensed from gravity and visual and idiotropic cues differs from the expected vertical. This theory has been successfully used to predict motion sickness in different vehicles on Earth. We have summarized the most outstanding and recent studies on the illusions and characteristics associated with spatial disorientation and SMS during weightlessness, such as cognitive map and mental rotation, the visual reorientation and inversion illusions, and orientation preferences between visual scenes and the internal z-axis of the body. The relationships between the SV and the incidence of and susceptibility to SMS as well as spatial disorientation were addressed. A consistent framework was presented to understand and explain SMS characteristics in more detail on the basis of the SV conflict theory, which is expected to be more advantageous in SMS prediction, prevention, and training.

  4. Mechanisms of selective attention and space motion sickness

    Science.gov (United States)

    Kohl, R. L.

    1987-01-01

    The neural mismatch theory of space motion sickness asserts that the central and peripheral autonomic sequelae of discordant sensory input arise from central integrative processes falling to reconcile patterns of incoming sensory information with existing memory. Stated differently, perceived novelty reaches a stress level as integrative mechanisms fail to return a sense of control to the individual in the new environment. Based on evidence summarized here, the severity of the neural mismatch may be dependent upon the relative amount of attention selectively afforded to each sensory input competing for control of behavior. Components of the limbic system may play important roles in match-mismatch operations, be therapeutically modulated by antimotion sickness drugs, and be optimally positioned to control autonomic output.

  5. Pharmacological and neurophysiological aspects of space/motion sickness

    Science.gov (United States)

    Lucot, James B.; Crampton, George H.

    1991-01-01

    A motorized motion testing device modeled after a Ferris wheel was constructed to perform motion sickness tests on cats. Details of the testing are presented, and some of the topics covered include the following: xylazine-induced emesis; analysis of the constituents of the cerebrospinal fluid (CSF) during motion sickness; evaluation of serotonin-1A (5-HT sub 1A) agonists; other 5HT receptors; antimuscarinic mechanisms; and antihistaminergic mechanisms. The ability of the following drugs to reduce motion sickness in the cats was examined: amphetamines, adenosinergic drugs, opioid antagonists, peptides, cannabinoids, cognitive enhancers (nootropics), dextromethorphan/sigma ligands, scopolamine, and diphenhydramine.

  6. Space motion sickness: The sensory motor controls and cardiovascular correlation

    Science.gov (United States)

    Souvestre, Philippe A.; Blaber, Andrew P.; Landrock, Clinton K.

    Background and PurposeSpace motion sickness (SMS) and related symptoms remain a major limiting factor in Space operations. A recent comprehensive literature review [J.R. Lackner, Z. DiZio, Space motion sickness, Experimental Brain Research 175 (2006) 377-399, doi 10.1007/s00221-006-0697-y] concluded that SMS does not represent a unique diagnostic entity, and there is no adequate predictor of SMS' susceptibility and severity. No countermeasure has been found reliable to prevent or treat SMS symptoms onset. Recent neurophysiological findings on sensory-motor controls monitoring [P.A. Souvestre, C. Landrock, Biomedical-performance monitoring and assessment of astronauts by means of an ocular vestibular monitoring system, Acta Astronautica, 60 (4-7) (2007) 313-321, doi:10.1016/j.actaastro.2006.08.013] and heart-rate variability (HRV) measurements relationship could explain post-flight orthostatic intolerance (PFOI) in astronauts [A.P. Blaber, R.L. Bondar, M.S. Kassam, Heart rate variability and short duration space flight: relationship to post-flight orthostatic intolerance, BMC Physiology 4 (2004) 6]. These two methodologies are generally overlooked in SMS' analysis. In this paper we present the case for a strong relationship between sensory-motor controls related symptoms, including orthostatic intolerance (OI) and SMS symptoms. MethodsThis paper expands on several previously published papers [J.R. Lackner, Z. DiZio, Space motion sickness, Experimental Brain Research 175 (2006) 377-399, doi 10.1007/s00221-006-0697-y; P.A. Souvestre, C. Landrock, Biomedical-performance monitoring and assessment of astronauts by means of an ocular vestibular monitoring system, Acta Astronautica, 60 (4-7) (2007) 313-321, doi:10.1016/j.actaastro.2006.08.013] along with an updated literature review. An analysis of a 10-year period clinical data from trauma patients experiencing postural deficiency syndrome (PDS) show assessment and monitoring techniques which successfully identify trauma

  7. Autogenic-Feedback Training for the Control of Space Motion Sickness

    Science.gov (United States)

    Cowings, Patricia S.; Toscano, W. B.

    1994-01-01

    This paper presents case-studies of 9 shuttle crewmembers (prime and alternates) and one U.S. Navy F-18 pilot, as they participated in all preflight training and testing activities in support of a life sciences flight experiment aboard Spacelab-J, and Spacelab-3. The primary objective of the flight experiment was to determine if Autogenic-feedback training (AFT), a physiological self-regulation training technique would be an effective treatment for motion sickness and space motion sickness in these crewmembers. Additional objectives of this study involved the examining human physiological responses to motion sickness on Earth and in space, as well as developing predictive criteria for susceptibility to space motion sickness based on ground-based data. Comparisons of these crewmembers are made to a larger set of subjects from previous experiments (treatment and "test-only" controls subjects). This paper describes all preflight methods, results and proposed changes for future tests.

  8. A re-investigation of the role of utricular asymmetries in Space Motion Sickness

    NARCIS (Netherlands)

    Nooij, S.A.E.; Vanspauwen, R.; Bos, J.E.; Wuyts, F.L.

    2011-01-01

    During the first days of spaceflight, about 50-70% of the astronauts experience symptoms of Space Motion Sickness (SMS). It has been proposed that an asymmetry between the left and right otolith organs contributes to an astronaut's individual susceptibility. A recently developed test to measure

  9. Autogenic-Feedback Training (AFT) as a preventive method for space motion sickness: Background and experimental design

    Science.gov (United States)

    Cowings, Patricia S.; Toscano, William B.

    1993-01-01

    Finding an effective treatment for the motion sickness-like symptoms that occur in space has become a high priority for NASA. The background research is reviewed and the experimental design of a formal life sciences shuttle flight experiment designed to prevent space motion sickness in shuttle crew members is presented. This experiment utilizes a behavioral medicine approach to solving this problem. This method, Autogenic-Feedback Training (AFT), involves training subjects to voluntarily control several of their own physiological responses to environmental stressors. AFT has been used reliably to increase tolerance to motion sickness during ground-based tests in over 200 men and women under a variety of conditions that induce motion sickness, and preliminary evidence from space suggests that AFT may be an effective treatment for space motion sickness as well. Proposed changes to this experiment for future manifests are included.

  10. Travelers' Health: Motion Sickness

    Science.gov (United States)

    ... sickness, especially when pregnant, menstruating, or on hormones. Race/ethnicity—Asians may be more susceptible to motion ... it, sitting in the front seat of a car or bus, sitting over the wing of an ...

  11. Dizziness and Motion Sickness

    Science.gov (United States)

    ... that extends into the inner ear can completely destroy both the hearing and equilibrium function of that ... motion sickness: •Do not read while traveling •Avoid sitting in the rear seat •Do not sit in ...

  12. Motion Sickness: First Aid

    Science.gov (United States)

    ... com. Accessed July 29, 2017. Priesol AJ. Motion sickness. https://www.uptodate.com/content/search. Accessed July 29, 2017. Brunette GW, et al. CDC Health Information for International Travel 2018. New York, N. ...

  13. First intramuscular administration in the U.S. space program. [of motion sickness drugs

    Science.gov (United States)

    Bagian, James P.

    1991-01-01

    In the past, the only kind of medicines used for symptomatic treatment of space motion sickness (SMS) in space had been oral, transdermal, or suppositories. This paper describes the effect of the first intramuscular (IM) administration of Phenergan (50-mg in single dose) on SMS in one subject who exhibited grade-3 symptoms and signs which persisted unabated throughout the first and the second flight days aboard the Space Shuttle. Thirty minutes after the injection, the subject had completely recovered. His symptoms were gone, his appetite was back, and he had no recurrences for the remainder of the flight. Since that experiment, intramuscular injections have been given nine more times on subsequent flights, with similar results.

  14. Autogenic-feedback training - A treatment for motion and space sickness

    Science.gov (United States)

    Cowings, Patricia S.

    1990-01-01

    A training method for preventing the occurrence of motion sickness in humans, called autogenic-feedback training (AFT), is described. AFT is based on a combination of biofeedback and autogenic therapy which involves training physiological self-regulation as an alternative to pharmacological management. AFT was used to reliably increase tolerance to motion-sickness-inducing tests in both men and women ranging in age from 18 to 54 years. The effectiveness of AFT is found to be significantly higher than that of protective adaptation training. Data obtained show that there is no apparent effect from AFT on measures of vestibular perception and no side effects.

  15. Assessment of Evidence Base from Medical Debriefs Data on Space Motion Sickness Incidence and Treatment

    Science.gov (United States)

    Younker, D.R.; Daniels, V.R.; Boyd, J.L.; Putcha, L.

    2008-01-01

    An objective of this data compilation and analysis project is to examine incidence and treatment efficacy of common patho-physiological disturbances during spaceflight. Analysis of medical debriefs data indicated that astronauts used medications to alleviate symptoms of four major ailments for which astronauts received treatment for sleep disturbances, space motion sickness (SMS), pain (headache, back pain) and sinus congestion. In the present data compilation and analysis project on SMS treatment during space missions, subject demographics (gender, age, first-time or repeat flyer), incidence and severity of SMS symptoms and subjective treatment efficacy from 317 crewmember debrief records were examined from STS-1 through STS-89. Preliminary analysis of data revealed that 50% of crew members reported SMS symptoms on at least one flight and 22% never experienced it. In addition, there were 387 medication dosing episodes reported, and promethazine was the most commonly used medication. Results of analysis of symptom check lists, medication use/efficacy and gender and flight record differences in incidence and treatment efficacy will be presented. Evidence gaps for treatment efficacy along with medication use trend analysis will be identified.

  16. General Automatic Components of Motion Sickness

    Science.gov (United States)

    Suter, S.; Toscano, W. B.; Kamiya, J.; Naifeh, K.

    1985-01-01

    A body of investigations performed in support of experiments aboard the space shuttle, and designed to counteract the symptoms of Space Adaptation Syndrome, which resemble those of motion sickness on Earth is reviewed. For these supporting studies, the automatic manifestations of earth-based motion sickness was examined. Heart rate, respiration rate, finger pulse volume and basal skin resistance were measured on 127 men and women before, during and after exposure to nauseogenic rotating chair tests. Significant changes in all autonomic responses were observed across the tests. Significant differences in autonomic responses among groups divided according to motion sickness susceptibility were also observed. Results suggest that the examination of autonomic responses as an objective indicator of motion sickness malaise is warranted and may contribute to the overall understanding of the syndrome on Earth and in Space.

  17. Hyperventilation in a motion sickness desensitization program

    NARCIS (Netherlands)

    Mert, A.; Bles, W.; Nooij, S.A.E.

    2007-01-01

    Introduction: In motion sickness desensitization programs, the motion sickness provocative stimulus is often a forward bending of the trunk on a rotating chair, inducing Coriolis effects. Since respiratory relaxation techniques are applied successfully in these courses, we investigated whether these

  18. Motion sickness: a negative reinforcement model.

    Science.gov (United States)

    Bowins, Brad

    2010-01-15

    Theories pertaining to the "why" of motion sickness are in short supply relative to those detailing the "how." Considering the profoundly disturbing and dysfunctional symptoms of motion sickness, it is difficult to conceive of why this condition is so strongly biologically based in humans and most other mammalian and primate species. It is posited that motion sickness evolved as a potent negative reinforcement system designed to terminate motion involving sensory conflict or postural instability. During our evolution and that of many other species, motion of this type would have impaired evolutionary fitness via injury and/or signaling weakness and vulnerability to predators. The symptoms of motion sickness strongly motivate the individual to terminate the offending motion by early avoidance, cessation of movement, or removal of oneself from the source. The motion sickness negative reinforcement mechanism functions much like pain to strongly motivate evolutionary fitness preserving behavior. Alternative why theories focusing on the elimination of neurotoxins and the discouragement of motion programs yielding vestibular conflict suffer from several problems, foremost that neither can account for the rarity of motion sickness in infants and toddlers. The negative reinforcement model proposed here readily accounts for the absence of motion sickness in infants and toddlers, in that providing strong motivation to terminate aberrant motion does not make sense until a child is old enough to act on this motivation.

  19. Effects of Autonomic Conditioning on Motion Sickness Tolerance

    Science.gov (United States)

    Cowings, P. S.; Toscano, W. B.

    1994-01-01

    This paper presents case-studies of 9 shuttle crewmembers (prime and alternates) and one U.S. Navy F-18 pilot, as they participated in all preflight training and testing activities in support of a life sciences flight experiment aboard Spacelab-J, and Spacelab-3. The primary objective of the flight experiment was to determine if Autogenic-feedback training (AFT), a physiological self-regulation training technique would be an effective treatment for motion sickness and space motion sickness in these crewmembers. Additional objectives of this study involved the examining human Physiological- responses to motion sickness on Earth and in space, as well as developing predictive criteria for susceptibility to space motion sickness based on ground-based data. Comparisons of these crewmembers are made to a larger set of subjects from previous experiments (treatment and test-only controls subjects). This paper describes all preflight methods, results and proposed changes for future tests.

  20. Motion sickness in ancient China: Seasickness and cart-sickness.

    Science.gov (United States)

    Brandt, Thomas; Bauer, Matthias; Benson, Judy; Huppert, Doreen

    2016-07-19

    To find and analyze descriptions of motion sickness in Chinese historical sources. Databases and dictionaries were searched for various terms for seasickness and travel sickness, which were then entered into databases of full texts allowing selection of relevant passages from about the third to the 19th century ad. Already in 300 ad the Chinese differentiated cart-sickness, particularly experienced by persons from the arid north of China, from a ship-illness experienced by persons from the south, where rivers were important for transportation and travel. In the Middle Ages, a third form of motion sickness was called litter-influence experienced by persons transported in a bed suspended between 2 long poles. The ancient Chinese recognized the particular susceptibility of children to motion sickness. Therapeutic recommendations include drinking the urine of young boys, swallowing white sand-syrup, collecting water drops from a bamboo stick, or hiding some earth from the middle of the kitchen hearth under the hair. The Chinese medical classics distinguished several forms of travel sickness, all of which had their own written characters. The pathophysiologic mechanism was explained by the medicine of correspondences, which was based on malfunctions within the body, its invasion by external pathogens like wind, or the deficit or surfeit of certain bodily substances such as the life force Qi. The concept of motion as the trigger of sickness initially appeared in a chapter on warding off the influence of demons and corpses, e.g., ancient magic and beliefs. © 2016 American Academy of Neurology.

  1. Space sickness on earth

    Science.gov (United States)

    Nooij, S. A. E.; Bos, J. E.; Groen, E. L.; Bles, W.; Ockels, W. J.

    2007-09-01

    During the first days in space, i.e., after a transition from 1G to 0G, more than 50% of the astro- (and cosmonauts) suffer from the Space Adaptation Syndrome (SAS).The symptoms of SAS, like nausea and dizziness, are especially provoked by head movements. Astronauts have mentioned close similarities between the symptoms of SAS and the symptoms they experienced after a 1 hour centrifuge run on Earth, i.e., after a transition from 3G to 1G (denoted by Sickness Induced by Centrifugation, SIC). During several space missions, we related susceptibility to SAS and to SIC in 11 astronauts and found 4 of them being susceptible to both SIC and SAS, and 7 being not susceptible to SIC nor to SAS. This correspondence in susceptibility suggests that SIC and SAS share the same underlying mechanism. To further study this mechanism, several vestibular parameters have been investigated (e.g. postural stability, vestibularly driven eye movements, subjective vertical). We found some striking changes in individual cases that are possibly due to the centrifuge run. However, the variability between subjects generally is very large, making physiological links to SIC and SAS still hard to find.

  2. Motion sickness, stress and the endocannabinoid system.

    Directory of Open Access Journals (Sweden)

    Alexander Choukèr

    Full Text Available BACKGROUND: A substantial number of individuals are at risk for the development of motion sickness induced nausea and vomiting (N&V during road, air or sea travel. Motion sickness can be extremely stressful but the neurobiologic mechanisms leading to motion sickness are not clear. The endocannabinoid system (ECS represents an important neuromodulator of stress and N&V. Inhibitory effects of the ECS on N&V are mediated by endocannabinoid-receptor activation. METHODOLOGY/PRINCIPAL FINDINGS: We studied the activity of the ECS in human volunteers (n = 21 during parabolic flight maneuvers (PFs. During PFs, microgravity conditions (<10(-2 g are generated for approximately 22 s which results in a profound kinetic stimulus. Blood endocannabinoids (anandamide and 2-arachidonoylglycerol, 2-AG were measured from blood samples taken in-flight before start of the parabolic maneuvers, after 10, 20, and 30 parabolas, in-flight after termination of PFs and 24 h later. Volunteers who developed acute motion sickness (n = 7 showed significantly higher stress scores but lower endocannabinoid levels during PFs. After 20 parabolas, blood anandamide levels had dropped significantly in volunteers with motion sickness (from 0.39+/-0.40 to 0.22+/-0.25 ng/ml but increased in participants without the condition (from 0.43+/-0.23 to 0.60+/-0.38 ng/ml resulting in significantly higher anandamide levels in participants without motion sickness (p = 0.02. 2-AG levels in individuals with motion sickness were low and almost unchanged throughout the experiment but showed a robust increase in participants without motion sickness. Cannabinoid-receptor 1 (CB1 but not cannabinoid-receptor 2 (CB2 mRNA expression in leucocytes 4 h after the experiment was significantly lower in volunteers with motion sickness than in participants without N&V. CONCLUSIONS/SIGNIFICANCE: These findings demonstrate that stress and motion sickness in humans are associated with impaired endocannabinoid

  3. Stroboscopic Goggles for Reduction of Motion Sickness

    Science.gov (United States)

    Reschke, M. F.; Somers, Jeffrey T.

    2005-01-01

    A device built around a pair of electronic shutters has been demonstrated to be effective as a prototype of stroboscopic goggles or eyeglasses for preventing or reducing motion sickness. The momentary opening of the shutters helps to suppress a phenomenon that is known in the art as retinal slip and is described more fully below. While a number of different environmental factors can induce motion sickness, a common factor associated with every known motion environment is sensory confusion or sensory mismatch. Motion sickness is a product of misinformation arriving at a central point in the nervous system from the senses from which one determines one s spatial orientation. When information from the eyes, ears, joints, and pressure receptors are all in agreement as to one s orientation, there is no motion sickness. When one or more sensory input(s) to the brain is not expected, or conflicts with what is anticipated, the end product is motion sickness. Normally, an observer s eye moves, compensating for the anticipated effect of motion, in such a manner that the image of an object moving relatively to an observer is held stationary on the retina. In almost every known environment that induces motion sickness, a change in the gain (in the signal-processing sense of gain ) of the vestibular system causes the motion of the eye to fail to hold images stationary on the retina, and the resulting motion of the images is termed retinal slip. The present concept of stroboscopic goggles or eyeglasses (see figure) is based on the proposition that prevention of retinal slip, and hence, the prevention of sensory mismatch, can be expected to reduce the tendency toward motion sickness. A device according to this concept helps to prevent retinal slip by providing snapshots of the visual environment through electronic shutters that are brief enough that each snapshot freezes the image on each retina. The exposure time for each snapshot is less than 5 ms. In the event that a higher

  4. Sensory conflict in motion sickness: An observer theory approach

    Science.gov (United States)

    Oman, Charles M.

    1989-01-01

    Motion sickness is the general term describing a group of common nausea syndromes originally attributed to motion-induced cerebral ischemia, stimulation of abdominal organ afferent, or overstimulation of the vestibular organs of the inner ear. Sea-, car-, and airsicknesses are the most commonly experienced examples. However, the discovery of other variants such as Cinerama-, flight simulator-, spectacle-, and space sickness in which the physical motion of the head and body is normal or absent has led to a succession of sensory conflict theories which offer a more comprehensive etiologic perspective. Implicit in the conflict theory is the hypothesis that neutral and/or humoral signals originate in regions of the brain subversing spatial orientation, and that these signals somehow traverse to other centers mediating sickness symptoms. Unfortunately, the present understanding of the neurophysiological basis of motion sickness is far from complete. No sensory conflict neuron or process has yet been physiologically identified. To what extent can the existing theory be reconciled with current knowledge of the physiology and pharmacology of nausea and vomiting. The stimuli which causes sickness, synthesizes a contemporary Observer Theory view of the Sensory Conflict hypothesis are reviewed, and a revised model for the dynamic coupling between the putative conflict signals and nausea magnitude estimates is presented. The use of quantitative models for sensory conflict offers a possible new approach to improving the design of visual and motion systems for flight simulators and other virtual environment display systems.

  5. Do lower vertebrates suffer from motion sickness?

    Science.gov (United States)

    Lychakov, Dmitri

    The poster presents literature data and results of the author’s studies with the goal to find out whether the lower animals are susceptible to motion sickness (Lychakov, 2012). In our studies, fish and amphibians were tested for 2 h and more by using a rotating device (f = 0.24 Hz, a _{centrifugal} = 0.144 g) and a parallel swing (f = 0.2 Hz, a _{horizontal} = 0.059 g). The performed studies did not revealed in 4 fish species and in toads any characteristic reactions of the motion sickness (sopite syndrome, prodromal preparatory behavior, vomiting). At the same time, in toads there appeared characteristic stress reactions (escape response, an increase of the number of urinations, inhibition of appetite), as well as some other reactions not associated with motion sickness (regular head movements, eye retractions). In trout fry the used stimulation promoted division of the individuals into the groups differing by locomotor reaction to stress, as well as the individuals with the well-expressed compensatory reaction that we called the otolithotropic reaction. Analysis of results obtained by other authors confirms our conclusions. Thus, the lower vertebrates, unlike mammals, are immune to motion sickness either under the land conditions or under conditions of weightlessness. On the basis of available experimental data and theoretical concepts of mechanisms of development the motion sickness, formulated in several hypotheses (mismatch hypothesis, Traisman‘ s hypothesis, resonance hypothesis), there presented the synthetic hypothesis of motion sickness that has the conceptual significance. According to the hypothesis, the unusual stimulation producing sensor-motor or sensor-sensor conflict or an action of vestibular and visual stimuli of frequency of about 0.2 Hz is perceived by CNS as poisoning and causes the corresponding reactions. The motion sickness actually is a byproduct of technical evolution. It is suggested that in the lower vertebrates, unlike mammals

  6. Motion Cues in Flight Simulation and Simulator Induced Sickness

    Science.gov (United States)

    1988-06-01

    military F7 .. vehicles, surface excavation equipment, underground mining devices, railway locomotives, .A space vehicles, shiv bridges, and submarines. Of...Evaluatort Rleference to Fukuda is: Fukuda, T. Postural behavior and motion sickness. Acca Otolaryngol. (Stockholm), 1976, B1:37-241.) %kI RTD-5

  7. Respiratory impact on motion sickness induced by linear motion

    NARCIS (Netherlands)

    Mert, A.; Klöpping-Ketelaars, I.; Bles, W.

    2009-01-01

    Motion sickness incidence (MSI) for vertical sinusoidal motion reaches a maximum at 0.167 Hz. Normal breathing frequency is close to this frequency. There is some evidence for synchronization of breathing with this stimulus frequency. If this enforced breathing takes place over a larger frequency

  8. Genetics Home Reference: motion sickness

    Science.gov (United States)

    ... motion, particularly traveling in a car, bus, train, airplane, or boat. Amusement park rides, skiing, and virtual ... Association ClinicalTrials.gov (1 link) ClinicalTrials.gov Scientific Articles on PubMed (1 link) PubMed OMIM (1 link) ...

  9. Motion sickness and otolith sensitivity - A pilot study of habituation to linear acceleration

    Science.gov (United States)

    Potvin, A. R.; Sadoff, M.; Billingham, J.

    1977-01-01

    Astronauts, particularly in Skylab flights, experienced varying degrees of motion sickness lasting 3-5 days. One possible mechanism for this motion sickness adaptation is believed to be a reduction in otolith sensitivity with an attendant reduction in sensory conflict. In an attempt to determine if this hypothesis is valid, a ground-based pilot study was conducted on a vertical linear accelerator. The extent of habituation to accelerations which initially produced motion sickness was evaluated, along with the possible value of habituation training to minimize the space motion sickness problem. Results showed that habituation occurred for 6 of the 8 subjects tested. However, in tests designed to measure dynamic and static otolith function, no significant differences between pre- and post-habituation tests were observed. Cross habituation effects to a standard Coriolis acceleration test were not significant. It is unlikely that ground-based pre-habituation to linear accelerations of the type examined would alter susceptibility to space motion sickness.

  10. Artificial horizon effects on motion sickness and performance.

    Science.gov (United States)

    Tal, Dror; Gonen, Adi; Wiener, Guy; Bar, Ronen; Gil, Amnon; Nachum, Zohar; Shupak, Avi

    2012-07-01

    To investigate whether the projection of Earth-referenced scenes during provocative motion can alleviate motion sickness severity and prevent motion sickness-induced degradation of performance. Exposure to unfamiliar motion patterns commonly results in motion sickness and decreased performance. Thirty subjects with moderate-to-severe motion sickness susceptibility were exposed to the recorded motion profile of a missile boat under moderate sea conditions in a 3-degrees-of-freedom ship motion simulator. During a 120-minute simulated voyage, the study participants were repeatedly put through a performance test battery and completed a motion sickness susceptibility questionnaire, while self-referenced and Earth-referenced visual scenes were projected inside the closed simulator cabin. A significant decrease was found in the maximal motion sickness severity score, from 9.83 ± 9.77 (mean ± standard deviation) to 7.23 ± 7.14 (p pitch, and heave movements of the simulator. Although there was a significant decrease in sickness severity, substantial symptoms still persisted. Decision making, vision, concentration, memory, simple reasoning, and psychomotor skills all deteriorated under the motion conditions. However, no significant differences between the projection conditions could be found in the scores of any of the performance tests. Visual information regarding the vessel's movement provided by an artificial horizon device might decrease motion sickness symptoms. However, although this device might be suitable for passive transportation, the continued deterioration in performance measures indicates that it provides no significant advantage for personnel engaged in the active operation of modern vessels.

  11. Autogenic-feedback training exercise is superior to promethazine for control of motion sickness symptoms

    Science.gov (United States)

    Cowings, P. S.; Toscano, W. B.

    2000-01-01

    Motion sickness symptoms affect approximately 50% of the crew during space travel and are commonly treated with intramuscular injections of promethazine. The purpose of this paper is to compare the effectiveness of three treatments for motion sickness: intramuscular injections (i.m.) of promethazine, a physiological training method (autogenic-feedback training exercise [AFTE]), and a no-treatment control. An earlier study tested the effects of promethazine on cognitive and psychomotor performance and motion sickness tolerance in a rotating chair. For the present paper, motion sickness tolerance, symptom reports, and physiological responses of these subjects were compared to matched subjects selected from an existing database who received either AFTE or no treatment. Three groups of 11 men, between the ages of 33 and 40 years, were matched on the number of rotations tolerated during their initial rotating-chair motion sickness test. The motion sickness test procedures and the 7-day interval between tests were the same for all subjects. The drug group was tested under four treatment conditions: baseline (no injections), a 25 mg dose of promethazine, a 50 mg dose of promethazine, and a placebo of sterile saline. AFTE subjects were given four 30-minute AFTE sessions before their second, third, and fourth motion sickness tests (6 hours total). The no-treatment control subjects were only given the four rotating-chair tests. Motion sickness tolerance was significantly increased after 4 hours of AFTE when compared to either 25 mg (p training.

  12. Autogenic Feedback Training Exercise: Controlling Physiological Responses to Mitigate Motion Sickness

    Science.gov (United States)

    Walton, Nia; Spencer, Telissa; Cowings, Patricia; Toscano, William B.

    2018-01-01

    During space travel approximately 50 of the crew experience symptoms of motion sickness that can range from mild forms of nausea or dizziness to severe malaise and vomiting1. Developing an effective treatment for these symptoms has become a priority of the National Aeronautics and Space Administration (NASA). Autogenic-Feedback Training Exercise (AFTE) is a nonpharmacological countermeasure for mitigating motion sickness. It involves training subjects to control physiological responses in high stress environments2. The primary goal of this experiment is to evaluate the effectiveness of AFTE for increasing tolerance to motion sickness in high stress environments.

  13. Motion sickness and postural sway in console video games.

    Science.gov (United States)

    Stoffregen, Thomas A; Faugloire, Elise; Yoshida, Ken; Flanagan, Moira B; Merhi, Omar

    2008-04-01

    We tested the hypotheses that (a) participants might develop motion sickness while playing "off-the-shelf" console video games and (b) postural motion would differ between sick and well participants, prior to the onset of motion sickness. There have been many anecdotal reports of motion sickness among people who play console video games (e.g., Xbox, PlayStation). Participants (40 undergraduate students) played a game continuously for up to 50 min while standing or sitting. We varied the distance to the display screen (and, consequently, the visual angle of the display). Across conditions, the incidence of motion sickness ranged from 42% to 56%; incidence did not differ across conditions. During game play, head and torso motion differed between sick and well participants prior to the onset of subjective symptoms of motion sickness. The results indicate that console video games carry a significant risk of motion sickness. Potential applications of this research include changes in the design of console video games and recommendations for how such systems should be used.

  14. [Vestibular testing abnormalities in individuals with motion sickness].

    Science.gov (United States)

    Ma, Yan; Ou, Yongkang; Chen, Ling; Zheng, Yiqing

    2009-08-01

    To evaluate the vestibular function of motion sickness. VNG, which tests the vestibular function of horizontal semicircular canal, and CPT, which tests vestibulospinal reflex and judge proprioceptive, visual and vestibular status, were performed in 30 motion sickness patients and 20 healthy volunteers (control group). Graybiel score was recorded at the same time. Two groups' Graybiel score (12.67 +/- 11.78 vs 2.10 +/- 6.23; rank test P<0.05), caloric test labyrinth value [(19.02 +/- 8.59) degrees/s vs (13.58 +/- 5.25) degrees/s; t test P<0.05], caloric test labyrinth value of three patients in motion sickness group exceeded 75 degrees/s. In computerized posturography testing (CPT), motion sickness patients were central type (66.7%) and disperse type (23.3%); all of control group were central type. There was statistical significance in two groups' CTP area, and motion sickness group was obviously higher than control group. While stimulating vestibulum in CPT, there was abnormality (35%-50%) in motion sickness group and none in control group. Generally evaluating CPT, there was only 2 proprioceptive hypofunction, 3 visual hypofunction, and no vestibular hypofunction, but none hypofunction in control group. Motion sickness patients have high vestibular susceptible, some with vestibular hyperfunction. In posturography, a large number of motion sickness patients are central type but no vestibular hypofunction, but it is hard to keep balance when stimulating vestibulum.

  15. Motion sickness history, food neophobia, and sensation seeking.

    Science.gov (United States)

    Alley, Thomas R; Willet, Kathleen A; Muth, Eric R

    2006-06-01

    Motion sickness is believed to be caused by conflicting sensory signals, a situation that mimics the effects of ingesting certain toxins. Thus, one might suspect that individuals who have experienced a relatively high frequency of motion sickness may be particularly vigilant about avoiding anything that produces nausea, induding potentially nauseating toxins. Consequently, they may be more resistant to trying new foods, i.e., be more food neophobic, since unfamiliar foods can have unexpected adverse effects due to toxins or allergens. Likewise, many highly stimulating experiences can trigger motion sickness, so individuals who are more susceptible may be more prone to avoid such experiences, i.e., be less sensation seeking. Finally, it was expected that food neophobia would be more frequent in individuals low on sensation seeking tendencies. Self-reported motion sickness history in 308 adults (M= 18.8 yr.; SD = 1.6) was correlated with scores on the Arnett Inventory of Sensation Seeking and the Food Neophobia Scale. As predicted, greater history of motion sickness was associated with lower Sensation Seeking scores. Food Neophobia was not correlated with motion sickness history but, as expected, was negatively correlated (r = -.42) with scores on Sensation Seeking. Further research is recommended that measures actual sensitivity to motion sickness.

  16. Virtual reality sickness questionnaire (VRSQ): Motion sickness measurement index in a virtual reality environment.

    Science.gov (United States)

    Kim, Hyun K; Park, Jaehyun; Choi, Yeongcheol; Choe, Mungyeong

    2018-05-01

    This study aims to develop a motion sickness measurement index in a virtual reality (VR) environment. The VR market is in an early stage of market formation and technological development, and thus, research on the side effects of VR devices such as simulator motion sickness is lacking. In this study, we used the simulator sickness questionnaire (SSQ), which has been traditionally used for simulator motion sickness measurement. To measure the motion sickness in a VR environment, 24 users performed target selection tasks using a VR device. The SSQ was administered immediately after each task, and the order of work was determined using the Latin square design. The existing SSQ was revised to develop a VR sickness questionnaire, which is used as the measurement index in a VR environment. In addition, the target selection method and button size were found to be significant factors that affect motion sickness in a VR environment. The results of this study are expected to be used for measuring and designing simulator sickness using VR devices in future studies. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Reliability of provocative tests of motion sickness susceptibility

    Science.gov (United States)

    Calkins, D. S.; Reschke, M. F.; Kennedy, R. S.; Dunlop, W. P.

    1987-01-01

    Test-retest reliability values were derived from motion sickness susceptibility scores obtained from two successive exposures to each of three tests: (1) Coriolis sickness sensitivity test; (2) staircase velocity movement test; and (3) parabolic flight static chair test. The reliability of the three tests ranged from 0.70 to 0.88. Normalizing values from predictors with skewed distributions improved the reliability.

  18. Vection and visually induced motion sickness: How are they related?

    Directory of Open Access Journals (Sweden)

    Behrang eKeshavarz

    2015-04-01

    Full Text Available The occurrence of visually induced motion sickness has been frequently linked to the sensation of illusory self-motion (so-called vection, however, the precise nature of this relationship is still not fully understood. To date, it is still a matter of debate whether or not vection is a necessary prerequisite for visually induced motion sickness (VIMS. That is, can there be visually induced motion sickness without any sensation of self-motion? In this paper, we will describe the possible nature of this relationship, review the literature that may speak to this relationship (including theoretical accounts of vection and VIMS, and offer suggestions with respect to operationally defining and reporting these phenomena in future.

  19. Potential non-pharmacological countermeasures for motion sickness

    NARCIS (Netherlands)

    Houben, M.M.J.; Bos, J.E.; Groen, E.L.

    2012-01-01

    Motion sickness can occur in any motion environment to which a person is not adapted, varying from cars, boats, and planes to fun rides and virtual reality. With symptoms such as nausea, vomiting, headache, lethargy, dizziness, and loss of concentration it causes discomfort for passengers but also a

  20. Motion in images is essential to cause motion sickness symptoms, but not to increase postural sway

    NARCIS (Netherlands)

    Lubeck, A.J.A.; Bos, J.E.; Stins, J.F.

    2015-01-01

    Abstract Objective It is generally assumed that motion in motion images is responsible for increased postural sway as well as for visually induced motion sickness (VIMS). However, this has not yet been tested. To that end, we studied postural sway and VIMS induced by motion and still images. Method

  1. Motion control, motion sickness, and the postural dynamics of mobile devices.

    Science.gov (United States)

    Stoffregen, Thomas A; Chen, Yi-Chou; Koslucher, Frank C

    2014-04-01

    Drivers are less likely than passengers to experience motion sickness, an effect that is important for any theoretical account of motion sickness etiology. We asked whether different types of control would affect the incidence of motion sickness, and whether any such effects would be related to participants' control of their own bodies. Participants played a video game on a tablet computer. In the Touch condition, the device was stationary and participants controlled the game exclusively through fingertip inputs via the device's touch screen. In the Tilt condition, participants held the device in their hands and moved the device to control some game functions. Results revealed that the incidence of motion sickness was greater in the Touch condition than in the Tilt condition. During game play, movement of the head and torso differed as a function of the type of game control. Before the onset of subjective symptoms of motion sickness, movement of the head and torso differed between participants who later reported motion sickness and those that did not. We discuss implications of these results for theories of motion sickness etiology.

  2. Motion sickness and tilts of the inertial force environment : Active suspension systems vs. active passengers

    NARCIS (Netherlands)

    Golding, J. F.; van der Bles, W.; Bos, J. E.; Haynes, T.; Gresty, M. A.

    2003-01-01

    Background: Maneuvering in vehicles exposes occupants to low frequency forces (<1 Hz) which can provoke motion sickness. Hypothesis: Aligning with the tilting inertial resultant (gravity + imposed horizontal acceleration: gravito-inertial force (GIF)) may reduce motion sickness when tilting is

  3. Reliability of psychophysiological responses across multiple motion sickness stimulation tests

    Science.gov (United States)

    Stout, C. S.; Toscano, W. B.; Cowings, P. S.

    1995-01-01

    Although there is general agreement that a high degree of variability exists between subjects in their autonomic nervous system responses to motion sickness stimulation, very little evidence exists that examines the reproducibility of autonomic responses within subjects during motion sickness stimulation. Our objectives were to examine the reliability of autonomic responses and symptom levels across five testing occasions using the (1) final minute of testing, (2) change in autonomic response and the change in symptom level, and (3) strength of the relationship between the change in symptom level and the change in autonomic responses across the entire motion sickness test. The results indicate that, based on the final minute of testing, the autonomic responses of heart rate, blood volume pulse, and respiration rate are moderately stable across multiple tests. Changes in heart rate, blood volume pulse, respiration rate, and symptoms throughout the test duration are less stable across the tests. Finally, autonomic responses and symptom levels are significantly related across the entire motion sickness test.

  4. Motion sickness symptoms in a ship motion simulator: effects of inside, outside, and no view

    NARCIS (Netherlands)

    Bos, J.E.; MacKinnon, S.N.; Patterson, A.

    2005-01-01

    Vehicle motion characteristics differ between air, road, and sea environments, both vestibularly and visually. Effects of vision on motion sickness have been studied before, though less systematically in a naval setting. It is hypothesized that appropriate visual information on self-motion is

  5. Pleasant music as a countermeasure against visually induced motion sickness.

    Science.gov (United States)

    Keshavarz, Behrang; Hecht, Heiko

    2014-05-01

    Visually induced motion sickness (VIMS) is a well-known side-effect in virtual environments or simulators. However, effective behavioral countermeasures against VIMS are still sparse. In this study, we tested whether music can reduce the severity of VIMS. Ninety-three volunteers were immersed in an approximately 14-minute-long video taken during a bicycle ride. Participants were randomly assigned to one of four experimental groups, either including relaxing music, neutral music, stressful music, or no music. Sickness scores were collected using the Fast Motion Sickness Scale and the Simulator Sickness Questionnaire. Results showed an overall trend for relaxing music to reduce the severity of VIMS. When factoring in the subjective pleasantness of the music, a significant reduction of VIMS occurred only when the presented music was perceived as pleasant, regardless of the music type. In addition, we found a gender effect with women reporting more sickness than men. We assume that the presentation of pleasant music can be an effective, low-cost, and easy-to-administer method to reduce VIMS. Copyright © 2013 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  6. The effect of mild motion sickness and sopite syndrome on multitasking cognitive performance.

    Science.gov (United States)

    Matsangas, Panagiotis; McCauley, Michael E; Becker, William

    2014-09-01

    In this study, we investigated the effects of mild motion sickness and sopite syndrome on multitasking cognitive performance. Despite knowledge on general motion sickness, little is known about the effect of motion sickness and sopite syndrome on multitasking cognitive performance. Specifically, there is a gap in existing knowledge in the gray area of mild motion sickness. Fifty-one healthy individuals performed a multitasking battery. Three independent groups of participants were exposed to two experimental sessions. Two groups received motion only in the first or the second session, whereas the control group did not receive motion. Measurements of motion sickness, sopite syndrome, alertness, and performance were collected during the experiment Only during the second session, motion sickness and sopite syndrome had a significant negative association with cognitive performance. Significant performance differences between symptomatic and asymptomatic participants in the second session were identified in composite (9.43%), memory (31.7%), and arithmetic (14.7%) task scores. The results suggest that performance retention between sessions was not affected by mild motion sickness. Multitasking cognitive performance declined even when motion sickness and soporific symptoms were mild. The results also show an order effect. We postulate that the differential effect of session on the association between symptomatology and multitasking performance may be related to the attentional resources allocated to performing the multiple tasks. Results suggest an inverse relationship between motion sickness effects on performance and the cognitive effort focused on performing a task. Even mild motion sickness has potential implications for multitasking operational performance.

  7. Roll motion stimuli : sensory conflict, perceptual weighting and motion sickness

    NARCIS (Netherlands)

    Graaf, B. de; Bles, W.; Bos, J.E.

    1998-01-01

    In an experiment with seventeen subjects interactions of visual roll motion stimuli and vestibular body tilt stimuli were examined in determining the subjective vertical. Interindi-vidual differences in weighting the visual information were observed, but in general visual and vestibular responses

  8. Motion sickness incidence during a round-the-world yacht race.

    Science.gov (United States)

    Turner, M; Griffin, M J

    1995-09-01

    Motion sickness experiences were obtained from participants in a 9 month, round the world yacht race. Race participants completed questionnaires on their motion sickness experience 1 week prior to the start of the race, during the race, and following the race. Yacht headings, sea states, and wind directions were recorded throughout the race. Illness and the occurrence of vomiting were related to the duration at sea and yacht encounter directions relative to the prevailing wind. Individual crewmember characteristics, the use of anti-motion sickness drugs, activity while at sea, and after-effects of yacht motion were also examined with respect to sickness occurrence. Sickness was greatest among females and younger crewmembers, and among crewmembers who used anti-motion sickness drugs. Sickness varied as a function of drug type and activity while at sea. Crewmembers who reported after-effects of yacht motion also reported greater sickness while at sea. The primary determinants of motion sickness were the duration of time spent at sea and yacht encounter direction to the prevailing wind.

  9. Demonstrating the potential for dynamic auditory stimulation to contribute to motion sickness.

    Directory of Open Access Journals (Sweden)

    Behrang Keshavarz

    Full Text Available Auditory cues can create the illusion of self-motion (vection in the absence of visual or physical stimulation. The present study aimed to determine whether auditory cues alone can also elicit motion sickness and how auditory cues contribute to motion sickness when added to visual motion stimuli. Twenty participants were seated in front of a curved projection display and were exposed to a virtual scene that constantly rotated around the participant's vertical axis. The virtual scene contained either visual-only, auditory-only, or a combination of corresponding visual and auditory cues. All participants performed all three conditions in a counterbalanced order. Participants tilted their heads alternately towards the right or left shoulder in all conditions during stimulus exposure in order to create pseudo-Coriolis effects and to maximize the likelihood for motion sickness. Measurements of motion sickness (onset, severity, vection (latency, strength, duration, and postural steadiness (center of pressure were recorded. Results showed that adding auditory cues to the visual stimuli did not, on average, affect motion sickness and postural steadiness, but it did reduce vection onset times and increased vection strength compared to pure visual or pure auditory stimulation. Eighteen of the 20 participants reported at least slight motion sickness in the two conditions including visual stimuli. More interestingly, six participants also reported slight motion sickness during pure auditory stimulation and two of the six participants stopped the pure auditory test session due to motion sickness. The present study is the first to demonstrate that motion sickness may be caused by pure auditory stimulation, which we refer to as "auditorily induced motion sickness".

  10. Eye movements to yaw, pitch, and roll about vertical and horizontal axes : Adaptation and motion sickness

    NARCIS (Netherlands)

    Bos, J. E.; van der Bles, W.; de Graaf, B.

    2002-01-01

    Background: In the search for parameters to predict motion sickness that can be measured in the laboratory, we performed a longitudinal investigation in aviators. Since the vestibular system is involved in the generation of motion sickness as well as eye movements, vestibuloocular reflex (VOR)

  11. Eye movements to yaw, pitch, and roll about vertical and horizontal axes : Adaptation, and motion sickness

    NARCIS (Netherlands)

    Bos, J.E.; Bles, W.; Graaf, B. de

    2002-01-01

    Background: In the search for parameters to predict motion sickness that can be measured in the laboratory, we performed a longitudinal investigation in aviators. Since the vestibular system is involved in the generation of motion sickness as well as eye movements, vestibulo-ocular reflex (VOR)

  12. Motion sickness and tilts of the inertial force environment: active suspension systems vs. active passengers

    NARCIS (Netherlands)

    Golding, J.F.; Bles, W.; Bos, J.E.; Haynes, T.; Gresty, M.A.

    2003-01-01

    Maneuvering in vehicles exposes occupants to low frequency forces (<1 Hz) which can provoke motion sickness. Hypothesis: Aligning with the tilting inertial resultant (gravity + imposed horizontal acceleration: gravito-inertial force (GIF)) may reduce motion sickness when tilting is either 'active'

  13. The effects of autogenic-feedback training on motion sickness severity and heart rate variability in astronauts

    Science.gov (United States)

    Toscano, William B.; Cowings, Patricia S.

    1994-01-01

    Space motion sickness (SMS) affects 50 percent of all people during early days of spaceflight. This study describes the results of two Shuttle flight experiments in which autogenic-feedback training (AFT), a physiological conditioning method, was tested as a treatment for this disorder. Of the six who were designated as flight subjects (two women and four men), three were given treatment and three served as controls (i.e., no AFT). Treatment subjects were given 6 hours of preflight AFT. Preflight results showed that AFT produced a significant increase in tolerance to rotating chair motion sickness tests. Further, this increased tolerance was associated with changes in specific physiological responses and reports of reduced malaise. Flight results showed that two of the three control subjects experienced repeated vomiting on the first mission day, while one subject experienced only moderate malaise. Of the three treatment subjects, one experienced mild discomfort, one moderate discomfort, and one severe motion sickness. Only the three control subjects took medication for symptom suppression. Measures of cardiac function reflective of vagal control were shown to be affected especially strongly on the first day of space flight. AFT given for control of heart rate, respiration, and other autonomic activity influenced both the vagal control measures and SMS. These data suggest that AFT may be an effective treatment for space motion sickness; however, this cannot be demonstrated conclusively with the small number of subjects described.

  14. Various anti-motion sickness drugs and core body temperature changes.

    Science.gov (United States)

    Cheung, Bob; Nakashima, Ann M; Hofer, Kevin D

    2011-04-01

    Blood flow changes and inactivity associated with motion sickness appear to exacerbate the rate of core temperature decrease during subsequent body cooling. We investigated the effects of various classes of anti-motion sickness drugs on core temperature changes. There were 12 healthy male and female subjects (20-35 yr old) who were given selected classes of anti-motion sickness drugs prior to vestibular Coriolis cross coupling induced by graded yaw rotation and periodic pitch-forward head movements in the sagittal plane. All subjects were then immersed in water at 18 degrees C for a maximum of 90 min or until their core temperature reached 35 degrees C. Double-blind randomized trials were administered, including a placebo, a non-immersion control with no drug, and six anti-motion sickness drugs: meclizine, dimenhydrinate, chlorpheniramine, promethazine + dexamphetamine, promethazine + caffeine, and scopolamine + dexamphetamine. A 7-d washout period was observed between trials. Core temperature and the severity of sickness were monitored throughout each trial. A repeated measures design was performed on the severity of sickness and core temperature changes prior to motion provocation, immediately after the motion sickness end point, and throughout the period of cold-water immersion. The most effective anti-motion sickness drugs, promethazine + dexamphetamine (with a sickness score/duration of 0.65 +/- 0.17) and scopolamine + dexamphetamine (with a sickness score/duration of 0.79 +/- 0.17), significantly attenuated the decrease in core temperature. The effect of this attenuation was lower in less effective drugs. Our results suggest that the two most effective anti-motion sickness drugs are also the most effective in attenuating the rate of core temperature decrease.

  15. Motion sickness increases the risk of accidental hypothermia.

    Science.gov (United States)

    Nobel, Gerard; Eiken, Ola; Tribukait, Arne; Kölegård, Roger; Mekjavic, Igor B

    2006-09-01

    Motion sickness (MS) has been found to increase body-core cooling during immersion in 28 degrees C water, an effect ascribed to attenuation of the cold-induced peripheral vasoconstriction (Mekjavic et al. in J Physiol 535(2):619-623, 2001). The present study tested the hypothesis that a more profound cold stimulus would override the MS effect on peripheral vasoconstriction and hence on the core cooling rate. Eleven healthy subjects underwent two separate head-out immersions in 15 degrees C water. In the control trial (CN), subjects were immersed after baseline measurements. In the MS-trial, subjects were rendered motion sick prior to immersion, by using a rotating chair in combination with a regimen of standardized head movements. During immersion in the MS-trial, subjects were exposed to an optokinetic stimulus (rotating drum). At 5-min intervals subjects rated their temperature perception, thermal comfort and MS discomfort. During immersion mean skin temperature, rectal temperature, the difference in temperature between the non-immersed right forearm and 3rd finger of the right hand (DeltaTff), oxygen uptake and heart rate were recorded. In the MS-trial, rectal temperature decreased substantially faster (33%, P < 0.01). Also, the DeltaTff response, an index of peripheral vasomotor tone, as well as the oxygen uptake, indicative of the shivering response, were significantly attenuated (P < 0.01 and P < 0.001, respectively) by MS. Thus, MS may predispose individuals to hypothermia by enhancing heat loss and attenuating heat production. This might have significant implications for survival in maritime accidents.

  16. Console video games, postural activity, and motion sickness during passive restraint.

    Science.gov (United States)

    Chang, Chih-Hui; Pan, Wu-Wen; Chen, Fu-Chen; Stoffregen, Thomas A

    2013-08-01

    We examined the influence of passive restraint on postural activity and motion sickness in individuals who actively controlled a potentially nauseogenic visual motion stimulus (a driving video game). Twenty-four adults (20.09 ± 1.56 years; 167.80 ± 7.94 cm; 59.02 ± 9.18 kg) were recruited as participants. Using elastic bands, standing participants were passively restrained at the head, shoulders, hips, and knees. During restraint, participants played (i.e., controlled) a driving video game (a motorcycle race), for 50 min. During game play, we recorded the movement of the head and torso, using a magnetic tracking system. Following game play, participants answered a forced choice, yes/no question about whether they were motion sick, and were assigned to sick and well groups on this basis. In addition, before and after game play, participants completed the Simulator Sickness Questionnaire, which provided numerical ratings of the severity of individual symptoms. Five of 24 participants (20.83 %) reported motion sickness. Participants moved despite being passively restrained. Both the magnitude and the temporal dynamics of movement differed between the sick and well groups. The results show that passive restraint of the body can reduce motion sickness when the nauseogenic visual stimulus is under participants' active control and confirm that motion sickness is preceded by distinct patterns of postural activity even during passive restraint.

  17. Role of endogenous opioid peptides in the pathogenesis of motion sickness

    International Nuclear Information System (INIS)

    Yasnetsov, V.V.; Il'ina, S.L.; Karsanova, S.K.; Medvedev, O.S.; Mokrousova, A.V.; Sabaev, V.V.; Shashkov, V.A.; Tigranyan, R.A.; Vakulina, O.P

    1986-01-01

    This paper examines the pathogenesis of motion sickness and the role of the various neurochemical systems of the body in the genesis of the condition. It has been shown that the endogenous opioid system participates in the genesis of several pathological processes; this was the motivation for the study. The plasma beta-endorphin level was determined in samples from 19 clinically healthy males. Considering the positive prophylactic and therapeutic effect of naloxone against motion sickness it can be postulated that endogenous opioid peptides participate in the genesis of the vestibulo-autonomic disorders in motion sickness

  18. Role of endogenous opioid peptides in the pathogenesis of motion sickness

    Energy Technology Data Exchange (ETDEWEB)

    Yasnetsov, V.V.; Il' ina, S.L.; Karsanova, S.K.; Medvedev, O.S.; Mokrousova, A.V.; Sabaev, V.V.; Shashkov, V.A.; Tigranyan, R.A.; Vakulina, O.P

    1986-01-01

    This paper examines the pathogenesis of motion sickness and the role of the various neurochemical systems of the body in the genesis of the condition. It has been shown that the endogenous opioid system participates in the genesis of several pathological processes; this was the motivation for the study. The plasma beta-endorphin level was determined in samples from 19 clinically healthy males. Considering the positive prophylactic and therapeutic effect of naloxone against motion sickness it can be postulated that endogenous opioid peptides participate in the genesis of the vestibulo-autonomic disorders in motion sickness.

  19. Evaluation of the relationship between motion sickness symptomatology and blood pressure, heart rate, and body temperature

    Science.gov (United States)

    Graybiel, A.; Lackner, J. R.

    1980-01-01

    This study investigated the relationship between the development of symptoms of motion sickness and changes in blood pressure, heart rate, and body temperature. Twelve subjects were each evaluated four times using the vestibular-visual interaction test (Graybiel and Lackner, 1980). The results were analyzed both within and across individual subjects. Neither a systematic group nor consistent individual relationship was found between the physiological parameters and the appearance of symptoms of motion sickness. These findings suggest that biofeedback control of the physiological variables studied is not likely to prevent the expression of motion sickness symptomatology.

  20. Assessment of otolith function using cervical and ocular vestibular evoked myogenic potentials in individuals with motion sickness.

    Science.gov (United States)

    Singh, Niraj Kumar; Pandey, Preeti; Mahesh, Soumya

    2014-01-01

    The involvement of otolith organs in motion sickness has long been debated; however, equivocal findings exist in literature. The present study thus aimed at evaluating the otolith functioning in individuals with motion sickness. Cervical and ocular vestibular evoked myogenic potentials were recorded from 30 individuals with motion sickness, 30 professional drivers and 30 healthy individuals. The results revealed no significant difference in latencies and amplitudes between the groups (p>0.05). Nonetheless, thresholds were significantly elevated and inter-aural asymmetry ratio significantly higher in motion sickness susceptible group (p otolithic function seem the likely reasons behind motion sickness susceptibility.

  1. A preliminary study of MR sickness evaluation using visual motion aftereffect for advanced driver assistance systems.

    Science.gov (United States)

    Nakajima, Sawako; Ino, Shuichi; Ifukube, Tohru

    2007-01-01

    Mixed Reality (MR) technologies have recently been explored in many areas of Human-Machine Interface (HMI) such as medicine, manufacturing, entertainment and education. However MR sickness, a kind of motion sickness is caused by sensory conflicts between the real world and virtual world. The purpose of this paper is to find out a new evaluation method of motion and MR sickness. This paper investigates a relationship between the whole-body vibration related to MR technologies and the motion aftereffect (MAE) phenomenon in the human visual system. This MR environment is modeled after advanced driver assistance systems in near-future vehicles. The seated subjects in the MR simulator were shaken in the pitch direction ranging from 0.1 to 2.0 Hz. Results show that MAE is useful for evaluation of MR sickness incidence. In addition, a method to reduce the MR sickness by auditory stimulation is proposed.

  2. Control of a virtual ambulation influences body movement and motion sickness

    Directory of Open Access Journals (Sweden)

    Hagstrom Jens

    2011-12-01

    Full Text Available Drivers typically are less susceptible to motion sickness than passengers. The influence of vehicle control has theoretical implications for the etiology of motion sickness, and has practical implications for the design of virtual environments. In the present study, participants either controlled or did not control a nonvehicular virtual avatar (i.e., an ambulatory character in a console video game. We examined the incidence of motion sickness and patterns of movement of the head and torso as participants either played or watched the game. Motion sickness incidence was lower when controlling the virutal avatar than when watching an avatar that was controlled by someone else. Patterns of head and torso movement differed between particpants who did and did not control the avatar. Indepenently, patterns of movement differed between participants who reported motion sickness and those who did not. The results suggest that motion sickness is influenced by control of stimulus motion, whether that motion arises from a vehicle or from any other source. We consider implications for the design of humancomputer interfaces.

  3. The effect of autogenic training and biofeedback on motion sickness tolerance.

    Science.gov (United States)

    Jozsvai, E E; Pigeau, R A

    1996-10-01

    Motion sickness is characterized by symptoms of vomiting, drowsiness, fatigue and idiosyncratic changes in autonomic nervous system (ANS) responses such as heart rate (HR) and skin temperature (ST). Previous studies found that symptoms of motion sickness are controllable through self-regulation of ANS responses and the best method to teach such control is autogenic-feedback (biofeedback) training. Recent experiments indicated that biofeedback training is ineffective in reducing symptoms of motion sickness or in increasing tolerance to motion. If biofeedback facilitates learning of ANS self-regulation then autogenic training with true feedback (TFB) should lead to better control over ANS responses and better motion tolerance than autogenic training with false feedback (FFB). If there is a relationship between ANS self-regulation and coping with motion stress, a significant correlation should be found between amounts of control over ANS responses and measures of motion tolerance and/or symptoms of motion sickness. There were 3 groups of 6 subjects exposed for 6 weeks to weekly sessions of Coriolis stimulation to induce motion sickness. Between the first and second Coriolis sessions, subjects in the experimental groups received five episodes of autogenic training with either true (group TFB) or false (group FFB) feedback on their HR and ST. The control group (CTL) received no treatment. Subjects learned to control their HR and ST independent of whether they received true or false feedback. Learned control of ST and HR was not related to severity of motion sickness or subject's ability to withstand Coriolis stimulation following treatment. A lack of significant correlation between these variables suggested that subjects were not able to apply their skills of ANS self-regulation in the motion environment, and/ or such skills had little value in reducing symptoms of motion sickness or enhancing their ability to withstand rotations.

  4. Control of a Virtual Vehicle Influences Postural Activity and Motion Sickness

    Science.gov (United States)

    Dong, Xiao; Yoshida, Ken; Stoffregen, Thomas A.

    2011-01-01

    Everyday experience suggests that drivers are less susceptible to motion sickness than passengers. In the context of inertial motion (i.e., physical displacement), this effect has been confirmed in laboratory research using whole body motion devices. We asked whether a similar effect would occur in the context of simulated vehicles in a visual…

  5. Effects of decades of physical driving on body movement and motion sickness during virtual driving.

    Directory of Open Access Journals (Sweden)

    Thomas A Stoffregen

    Full Text Available We investigated relations between experience driving physical automobiles and motion sickness during the driving of virtual automobiles. Middle-aged individuals drove a virtual automobile in a driving video game. Drivers were individuals who had possessed a driver's license for approximately 30 years, and who drove regularly, while non-drivers were individuals who had never held a driver's license, or who had not driven for more than 15 years. During virtual driving, we monitored movement of the head and torso. During virtual driving, drivers became motion sick more rapidly than non-drivers, but the incidence and severity of motion sickness did not differ as a function of driving experience. Patterns of movement during virtual driving differed as a function of driving experience. Separately, movement differed between participants who later became motion sick and those who did not. Most importantly, physical driving experience influenced patterns of postural activity that preceded motion sickness during virtual driving. The results are consistent with the postural instability theory of motion sickness, and help to illuminate relations between the control of physical and virtual vehicles.

  6. Reliability of Autonomic Responses and Malaise Across Multiple Motion Sickness Stimulation Tests

    Science.gov (United States)

    Stout, Cynthia S.; Toscano, William B.; Cowings, Patricia S.

    1993-01-01

    There is general agreement that a high degree of variability exists between subjects in their autonomic nervous system responses to motion sickness stimulation. Additionally, a paucity of data exists that examines the variability within an individual across repeated motion sickness tests. Investigators have also examined the relationship of autonomic responses to motion sickness development. These investigations have used analyses at discrete points in time to describe this relationship. This approach fails to address the time course of autonomic responses and malaise development throughout the motion sickness test. Our objectives were to examine the reliability of autonomic responses and malaise using the final minute of the motion sickness test across five testing occasions, to examine the reliability of the change in autonomic responses and the change in malaise across five testing occasions, and to examine the relationship between changes in autonomic responses and changes in malaise level across the entire motion sickness test. Our results indicate that, based on the final minute of testing, the autonomic responses of heart rate, blood volume pulse, and respiration rate are moderately stable across multiple tests. Changes in heart rate, blood volume pulse, respiration rate, and malaise throughout the test duration were less stable across the tests. We attribute this instability to variations in individual susceptibility and the error associated with estimating a measure of autonomic gain.

  7. Behavioral methods of alleviating motion sickness: effectiveness of controlled breathing and a music audiotape.

    Science.gov (United States)

    Yen Pik Sang, Fleur D; Billar, Jessica P; Golding, John F; Gresty, Michael A

    2003-01-01

    Behavioral countermeasures for motion sickness would be advantageous because of the side effects of antiemetic drugs, but few alternative treatments are available. The objective of this study was to compare the effectiveness of controlling breathing and listening to a music audiotape designed to reduce motion sickness symptoms, on increasing tolerance to motion-induced nausea. Twenty-four healthy subjects were exposed to nauseogenic Coriolis stimulation on a rotating turntable under three conditions: whilst focusing on controlling breathing; listening to a music audiotape; or without intervention (control). The three conditions were performed by each subject according to a replicated factorial design at 1-week intervals at the same time of day. Ratings of motion sickness were obtained every 30 seconds. Once a level of mild nausea was reached subjects commenced controlling breathing or listened to the music audiotape. Motion was stopped after the onset of moderate nausea. Mean (+/- SD) motion exposure time in minutes tolerated before the onset of moderate nausea was significantly longer (p music (10.4 +/- 5.6 min) compared with control (9.2 +/- 5.9 min). Both controlling breathing and the music audiotape provided significant protection against motion sickness and with similar effectiveness. These nonpharmacologic countermeasures are only half as effective as standard doses of anti-motion sickness drugs, such as oral scopolamine; however, they are easy to implement and free of side effects.

  8. Relationship between motion sickness, migraine and menstruation in crew members of a "round the world" yacht race.

    Science.gov (United States)

    Grunfeld, E; Gresty, M A

    1998-11-15

    The similarities between the symptoms reported by patients with migraine and those experienced by severely motion sick individuals raises the question of whether the two conditions involve common mechanisms. In women, attacks of migraine may follow the menstrual cycle, and anecdote suggests this may also be true of motion sickness. The aim of this study was to determine whether there was a cyclical pattern in the occurrence of migraine/headache and motion sickness among crew members of a "round the world" yacht race. The participants were asked to complete pre- and postrace questionnaires that related to their susceptibility to motion sickness and headache/migraine; additionally, the female subjects were asked for details about their menstrual cycle. During the race the subjects completed a logbook to record the occurrence of motion sickness (using a four-point scale), migraine/headache (including the type of headache), menstruation, medication consumption and duties aboard the yacht. Female sailors were found to be more prone to motion sickness than the males. Motion sickness was also found to be linked to time at sea, and subjects who suffered migraine during the race were also more susceptible to motion sickness. A distinct pattern was found in the occurrence of motion sickness and headache that related to the menstrual cycle, although motion sickness and headache did not generally occur together in most of the subjects. A cyclical pattern was not obvious for the male subjects.

  9. The influence of sleep deprivation and oscillating motion on sleepiness, motion sickness, and cognitive and motor performance.

    Science.gov (United States)

    Kaplan, Janna; Ventura, Joel; Bakshi, Avijit; Pierobon, Alberto; Lackner, James R; DiZio, Paul

    2017-01-01

    Our goal was to determine how sleep deprivation, nauseogenic motion, and a combination of motion and sleep deprivation affect cognitive vigilance, visual-spatial perception, motor learning and retention, and balance. We exposed four groups of subjects to different combinations of normal 8h sleep or 4h sleep for two nights combined with testing under stationary conditions or during 0.28Hz horizontal linear oscillation. On the two days following controlled sleep, all subjects underwent four test sessions per day that included evaluations of fatigue, motion sickness, vigilance, perceptual discrimination, perceptual learning, motor performance and learning, and balance. Sleep loss and exposure to linear oscillation had additive or multiplicative relationships to sleepiness, motion sickness severity, decreases in vigilance and in perceptual discrimination and learning. Sleep loss also decelerated the rate of adaptation to motion sickness over repeated sessions. Sleep loss degraded the capacity to compensate for novel robotically induced perturbations of reaching movements but did not adversely affect adaptive recovery of accurate reaching. Overall, tasks requiring substantial attention to cognitive and motor demands were degraded more than tasks that were more automatic. Our findings indicate that predicting performance needs to take into account in addition to sleep loss, the attentional demands and novelty of tasks, the motion environment in which individuals will be performing and their prior susceptibility to motion sickness during exposure to provocative motion stimulation. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Perceptually Uniform Motion Space.

    Science.gov (United States)

    Birkeland, Asmund; Turkay, Cagatay; Viola, Ivan

    2014-11-01

    Flow data is often visualized by animated particles inserted into a flow field. The velocity of a particle on the screen is typically linearly scaled by the velocities in the data. However, the perception of velocity magnitude in animated particles is not necessarily linear. We present a study on how different parameters affect relative motion perception. We have investigated the impact of four parameters. The parameters consist of speed multiplier, direction, contrast type and the global velocity scale. In addition, we investigated if multiple motion cues, and point distribution, affect the speed estimation. Several studies were executed to investigate the impact of each parameter. In the initial results, we noticed trends in scale and multiplier. Using the trends for the significant parameters, we designed a compensation model, which adjusts the particle speed to compensate for the effect of the parameters. We then performed a second study to investigate the performance of the compensation model. From the second study we detected a constant estimation error, which we adjusted for in the last study. In addition, we connect our work to established theories in psychophysics by comparing our model to a model based on Stevens' Power Law.

  11. Orientation Preferences and Motion Sickness Induced in a Virtual Reality Environment.

    Science.gov (United States)

    Chen, Wei; Chao, Jian-Gang; Zhang, Yan; Wang, Jin-Kun; Chen, Xue-Wen; Tan, Cheng

    2017-10-01

    Astronauts' orientation preferences tend to correlate with their susceptibility to space motion sickness (SMS). Orientation preferences appear universally, since variable sensory cue priorities are used between individuals. However, SMS susceptibility changes after proper training, while orientation preferences seem to be intrinsic proclivities. The present study was conducted to investigate whether orientation preferences change if susceptibility is reduced after repeated exposure to a virtual reality (VR) stimulus environment that induces SMS. A horizontal supine posture was chosen to create a sensory context similar to weightlessness, and two VR devices were used to produce a highly immersive virtual scene. Subjects were randomly allocated to an experimental group (trained through exposure to a provocative rotating virtual scene) and a control group (untrained). All subjects' orientation preferences were measured twice with the same interval, but the experimental group was trained three times during the interval, while the control group was not. Trained subjects were less susceptible to SMS, with symptom scores reduced by 40%. Compared with untrained subjects, trained subjects' orientation preferences were significantly different between pre- and posttraining assessments. Trained subjects depended less on visual cues, whereas few subjects demonstrated the opposite tendency. Results suggest that visual information may be inefficient and unreliable for body orientation and stabilization in a rotating visual scene, while reprioritizing preferences for different sensory cues was dynamic and asymmetric between individuals. The present findings should facilitate customization of efficient and proper training for astronauts with different sensory prioritization preferences and dynamic characteristics.Chen W, Chao J-G, Zhang Y, Wang J-K, Chen X-W, Tan C. Orientation preferences and motion sickness induced in a virtual reality environment. Aerosp Med Hum Perform. 2017

  12. The efficacy of airflow and seat vibration on reducing visually induced motion sickness

    NARCIS (Netherlands)

    D’Amour, Sarah; Bos, Jelte E.; Keshavarz, Behrang

    2017-01-01

    Visually induced motion sickness (VIMS) is a well-known sensation in virtual environments and simulators, typically characterized by a variety of symptoms such as pallor, sweating, dizziness, fatigue, and/or nausea. Numerous methods to reduce VIMS have been previously introduced; however, a reliable

  13. The effect of internal and external fields of view on visually induced motion sickness

    NARCIS (Netherlands)

    Bos, J.E.; Vries, S.C. de; Emmerik, M.L. van; Groen, E.L.

    2010-01-01

    Field of view (FOV) is said to affect visually induced motion sickness. FOV, however, is characterized by an internal setting used by the graphics generator (iFOV) and an external factor determined by screen size and viewing distance (eFOV). We hypothesized that especially the incongruence between

  14. [Pharmacological prophylaxis of vestibulo-autonomous syndrome (motion sickness) in model investigations].

    Science.gov (United States)

    Shashkov, V S; Iasnetsov, V V; Shashkov, A V; Il'ina, S L; Galle, R R; Sabaev, V V; Potapov, M G

    2000-01-01

    The authors summarize results of multiyear investigations at the Institute of Biomedical Problems of induced motion sickness and development of prophylactic medicaments representing various classes of biologically active substances (choline blocking agents, sympathomimetics, antihistamines etc.) prescribed singularly or in an combination based on the knowledge of MS-provoking inter-receptor interactions and therapeutic effects of drugs.

  15. Reducing motion sickness - A comparison of autogenic-feedback training and an alternative cognitive task

    Science.gov (United States)

    Toscano, W. B.; Cowings, P. S.

    1982-01-01

    Eighteen men were randomly assigned to three groups matched for susceptibility to Coriolis motion sickness. All subjects were given six Coriolis Sickness Susceptibility Index (CSSI) tests separated by 5-d intervals. Treatment Group I subjects were taught to control their own autonomic responses before the third, fourth, and fifth CSSI tests (6 h total training). Group II subjects were given 'sham' training in an alternative cognitive task under conditions otherwise identical to those of Group I. Group III subjects received no treatment. Results showed that Group I subjects could withstand the stress of Coriolis acceleration significantly longer after training. Neither of the other two groups changed significantly.

  16. A heuristic mathematical model for the dynamics of sensory conflict and motion sickness

    Science.gov (United States)

    Oman, C. M.

    1982-01-01

    By consideration of the information processing task faced by the central nervous system in estimating body spatial orientation and in controlling active body movement using an internal model referenced control strategy, a mathematical model for sensory conflict generation is developed. The model postulates a major dynamic functional role for sensory conflict signals in movement control, as well as in sensory-motor adaptation. It accounts for the role of active movement in creating motion sickness symptoms in some experimental circumstance, and in alleviating them in others. The relationship between motion sickness produced by sensory rearrangement and that resulting from external motion disturbances is explicitly defined. A nonlinear conflict averaging model is proposed which describes dynamic aspects of experimentally observed subjective discomfort sensation, and suggests resulting behaviours. The model admits several possibilities for adaptive mechanisms which do not involve internal model updating. Further systematic efforts to experimentally refine and validate the model are indicated.

  17. A Review of Motion Sickness with Special Reference to Simulator Sickness

    Science.gov (United States)

    1985-04-15

    intuitive, neo-Freudian and neo- Pavlovian ! Although there are no hard data to support the supposition that anxiety is a provocative stimulus for motion...with increased cholinergic activity (Koelle. 1965) and decreased adrenergic. but the relationships aro not cleat-cut (Tang, 1970). While the drugs

  18. Imagined Spaces: Motion Graphics in Performance Spaces

    DEFF Research Database (Denmark)

    Steijn, Arthur

    2016-01-01

    through theories drawn from two different fields. The first is from the field of direct visual perception as explored and described by the American psychologist J. J. Gibson. I supplement this angle by introducing relevant new media theories extracted from writings from L. Manovich. I also briefly...... introduce a second theoretic perspective from neuroscience, especially neurological theories related to aesthetic experiences as studied, categorized and explained by V. S. Ramachandran. Key Words: Motion graphics, video projections, space, direct visual perception, design process, new media, neuroscience...

  19. Adaptive Changes In Postural Equilibrium And Motion Sickness Following Repeated Exposures To Virtual Environments

    Science.gov (United States)

    Harm, D. L.; Taylor, L. C.

    2006-01-01

    Virtual environments offer unique training opportunities, particularly for training astronauts and preadapting them to the novel sensory conditions of microgravity. Two unresolved human factors issues in virtual reality (VR) systems are: 1) potential "cybersickness", and 2) maladaptive sensorimotor performance following exposure to VR systems. Interestingly, these aftereffects are often quite similar to adaptive sensorimotor responses observed in astronauts during and/or following space flight. Changes in the environmental sensory stimulus conditions and the way we interact with the new stimuli may result in motion sickness, and perceptual, spatial orientation and sensorimotor disturbances. Initial interpretation of novel sensory information may be inappropriate and result in perceptual errors. Active exploratory behavior in a new environment, with resulting feedback and the formation of new associations between sensory inputs and response outputs, promotes appropriate perception and motor control in the new environment. Thus, people adapt to consistent, sustained alterations of sensory input such as those produced by microgravity, unilateral labyrinthectomy and experimentally produced stimulus rearrangements. Adaptation is revealed by aftereffects including perceptual disturbances and sensorimotor control disturbances. The purpose of the current study was to compare disturbances in postural control produced by dome and head-mounted virtual environment displays, and to examine the effects of exposure duration, and repeated exposures to VR systems. Forty-one subjects (21 men, 20 women) participated in the study with an age range of 21-49 years old. One training session was completed in order to achieve stable performance on the posture and VR tasks before participating in the experimental sessions. Three experimental sessions were performed each separated by one day. The subjects performed a navigation and pick and place task in either a dome or head-mounted display

  20. The effect of internal and external fields of view on visually induced motion sickness.

    Science.gov (United States)

    Bos, Jelte E; de Vries, Sjoerd C; van Emmerik, Martijn L; Groen, Eric L

    2010-07-01

    Field of view (FOV) is said to affect visually induced motion sickness. FOV, however, is characterized by an internal setting used by the graphics generator (iFOV) and an external factor determined by screen size and viewing distance (eFOV). We hypothesized that especially the incongruence between iFOV and eFOV would lead to sickness. To that end we used a computer game environment with different iFOV and eFOV settings, and found the opposite effect. We speculate that the relative large differences between iFOV and eFOV used in this experiment caused the discrepancy, as may be explained by assuming an observer model controlling body motion. Copyright 2009 Elsevier Ltd. All rights reserved.

  1. A Comparison of Intranasal and Oral Scopolamine for Motion Sickness Prevention in Military Personnel

    Science.gov (United States)

    2008-08-18

    G., Ho, T., Lee, S., Manaretto, J., & Tsai, C. (2003). Transdermal scopolamine drug delivery systems for motion sickness. Retrieved August 14, 2007...earlier studies, the current study was able to utilize a precise drug delivery system to achieve tight control on the amount of scopolamine administered...widely used medication, and perhaps the most extensively researched, is the anticholinergic drug scopolamine. Scopolamine, in oral and transdermal form

  2. Brain blood-flow changes during motion sickness. [thalamus vascular changes in dogs during swing tests

    Science.gov (United States)

    Johnson, W. H.; Hsuen, J.

    1973-01-01

    The possibility of diminished blood flow in the brain is studied as one of the factors resulting from an increase in skeletal muscle blood volume concomitant with other characteristics of motion sickness. Thermistors are implanted in the thalamus of dogs and blood flow changes are recorded while they are subjected to sinusoidal movement on a two pole swing. Results of these initial steps in a proposed long term exploration of different areas of the brain are presented.

  3. The Effect of Mild Motion Sickness and Sopite Syndrome on Multitasking Cognitive Performance

    Science.gov (United States)

    2013-03-01

    useful as a predictor of performance in occupations such as pilot , where demands on multitasking are presumably high.” 33 It is interesting to assess...Council Committee on Selection and Training of Aircraft Pilots , Executive Subcommittee. Washington, D.C. Wendt, G. R. (1951). Vestibular functions. In S...public release; distribution is unlimited THE EFFECT OF MILD MOTION SICKNESS AND SOPITE SYNDROME ON MULTITASKING COGNITIVE PERFORMANCE by

  4. The efficacy of airflow and seat vibration on reducing visually induced motion sickness.

    Science.gov (United States)

    D'Amour, Sarah; Bos, Jelte E; Keshavarz, Behrang

    2017-09-01

    Visually induced motion sickness (VIMS) is a well-known sensation in virtual environments and simulators, typically characterized by a variety of symptoms such as pallor, sweating, dizziness, fatigue, and/or nausea. Numerous methods to reduce VIMS have been previously introduced; however, a reliable countermeasure is still missing. In the present study, the effect of airflow and seat vibration to alleviate VIMS was investigated. Eighty-two participants were randomly assigned to one of four groups (airflow, vibration, combined airflow and vibration, and control) and then exposed to a 15 min long video of a bicycle ride shot from first-person view. VIMS was measured using the Fast Motion Sickness Scale (FMS) and the Simulator Sickness Questionnaire (SSQ). Results showed that the exposure of airflow significantly reduced VIMS, whereas the presence of seat vibration, in contrast, did not have an impact on VIMS. Additionally, we found that females reported higher FMS scores than males, however, this sex difference was not found in the SSQ scores. Our findings demonstrate that airflow can be an effective and easy-to-apply technique to reduce VIMS in virtual environments and simulators, while vibration applied to the seat is not a successful method.

  5. The relationship of motion sickness susceptibility to learned autonomic control for symptom suppression

    Science.gov (United States)

    Cowings, P. S.; Toscano, W. B.

    1982-01-01

    Twenty-four men were randomly assigned to four equal groups matched in terms of their Coriolis Sickness Susceptibility Index (CSSI). Two groups of subjects were highly susceptible to motion sickness, and two groups were moderately susceptible. All subjects were given six C551 tests at 5-d intervals. Treatment Groups I (highly susceptible) and II (moderately susceptible) were taught to control their autonomic responses, using a training method called autogenic-feedback training (AFT) before the third, fourth, and fifth CSSI tests. Control groups III (highly susceptible) and IV (moderately susceptible) received no treatment. Results showed that both treatment groups significantly improved performance on CSSI tests after training; neither of the control groups changed significantly. Highly and moderately susceptible subjects in the two treatment groups improved at comparable rates. Highly susceptible control group subjects did not habituate across tests as readily as the moderately susceptible controls.

  6. Differences in Otolith and Abdominal Viscera Graviceptor Dynamics: Implications for Motion Sickness and Perceived Body Position

    Science.gov (United States)

    vonGierke, Henning E.; Parker, Donald E.

    1993-01-01

    Human graviceptors, located in the trunk by Mittelstaedt probably transduce acceleration by abdominal viscera motion. As demonstrated previously in biodynamic vibration and impact tolerance research the thoraco-abdominal viscera exhibit a resonance at 4 to 6 Hz. Behavioral observations and mechanical models of otolith graviceptor response indicate a phase shift increasing with frequency between 0.01 and O.5 Hz. Consequently the potential exists for intermodality sensory conflict between vestibular and visceral graviceptor signals at least at the mechanical receptor level. The frequency range of this potential conflict corresponds with the primary frequency range for motion sickness incidence in transportation, in subjects rotated about Earth-horizontal axes (barbecue spit stimulation) and in periodic parabolic flight microgravity research and also for erroneous perception of vertical oscillations in helicopters. We discuss the implications of this hypothesis for previous self motion perception research and suggestions for various future studies.

  7. Motion sickness and development of synergy within the spatial orientation system. A hypothetical unifying concept

    Science.gov (United States)

    Guedry, F. E.; Rupert, A. R.; Reschke, M. F.

    1998-01-01

    Adaptation to research paradigms such as rotating rooms and optical alteration of visual feedback during movement results in development of perceptual-motor programs that provide the reflexive assistance that is necessary to skilled control of movement and balance. The discomfort and stomach awareness that occur during the adaptation process has been attributed to conflicting sensory information about the state of motion. Vestibular signals depend on the kinematics of head movements irrespective of the presence or absence of signals from other senses. We propose that sensory conflict when vestibular signals are at least one component of the conflict are innately disturbing and unpleasant. This innate reaction is part of a continuum that operates early in life to prevent development of inefficient perceptual-motor programs. This reaction operates irrespective of and in addition to reward and punishment from parental guidance or goal attainment to yield efficient control of whole body movement in the operating environment of the individual. The same mechanism is involved in adapting the spatial orientation system to strange environments. This conceptual model "explains" why motion sickness is associated with adaptation to novel environments and is in general consistent with motion sickness literature.

  8. Motion Sickness

    Science.gov (United States)

    ... potatoes. Don’t eat greasy, spicy, or acidic foods just before or during travel. Drink plenty of water. Avoid alcohol. Get a ... Conditions Prevention and Wellness Staying Healthy Healthy Living Travel ... myhealthfinder Food and Nutrition Healthy Food Choices Weight Loss and ...

  9. The application of virtual reality technology to testing resistance to motion sickness

    Directory of Open Access Journals (Sweden)

    Menshikova G. Ya.

    2017-09-01

    Full Text Available Background. Prolonged exposure to moving images in virtual reality systems can cause virtual reality induced motion sickness (VIMS. The ability to resist motion sickness may be associated with the level of vestibular function development. objective. The aim of the present research is to study the oculomotor characteristics of individuals whose observation of moving virtual environments causes the VIMS effect. We hypothesized that people who have a robust vestibular function as a result of their professional activity, are less susceptible to VIMS than people who have no such professional abilities. The differences in people’s abilities to resist the effects of the virtual environment may be revealed in the oculomotor characteristics registered during their interaction with a virtual environment. Design. Figure skaters, football players, wushu fighters, and non-trained people were tested. e CAVE virtual reality system was used to initiate the VIMS effect. three virtual scenes were constructed consisting of many bright balls moving as a whole around the observer. e scenes differed in the width of the visual field; all balls subtended either 45°, 90° or 180°. Results. The results showed more active eye movements for athletes compared to non-trained people, i.e. an increase in blink, fixation, and saccade counts. A decrease in saccadic amplitudes was revealed for figure skaters. These characteristics were considered specific indicators of the athletes’ ability to resist motion sickness. Conclusions. It was found that the strength of the VIMS effect increased with the increasing width of the visual field. The effectiveness of virtual reality and eye-tracking technologies to test the VIMS effect was demonstrated.

  10. The use of EEG to measure cerebral changes during computer-based motion-sickness-inducing tasks

    Science.gov (United States)

    Strychacz, Christopher; Viirre, Erik; Wing, Shawn

    2005-05-01

    Motion sickness (MS) is a stressor commonly attributed with causing serious navigational and performance errors. The distinct nature of MS suggests this state may have distinct neural markers distinguishable from other states known to affect performance (e.g., stress, fatigue, sleep deprivation, high workload). This pilot study used new high-resolution electro-encephalograph (EEG) technologies to identify distinct neuronal activation changes that occur during MS. Brain EEG activity was monitored while subjects performed a ball-tracking task and viewed stimuli on a projection screen intended to induce motion sickness/spatial disorientation. Results show the presence of EEG spectral changes in all subjects who developed motion sickness when compared to baseline levels. These changes included: 1) low frequency (1 to 10 Hz) changes that may reflect oculomotor movements rather than intra-cerebral sources; 2) increased spectral power across all frequencies (attributable to increased scalp conductivity related to sweating), 3) local increases of power spectra in the 20-50 Hz range (likely attributable to external muscles on the skull) and; 4) a central posterior (occipital) independent component that shows suppression of a 20 Hz peak in the MS condition when compared to baseline. Further research is necessary to refine neural markers, characterize their origin and physiology, to distinguish between motion sickness and other states and to enable markers to be used for operator state monitoring and the designing of interventions for motion sickness.

  11. A Historical View of Motion Sickness-A Plague at Sea and on Land, Also with Military Impact.

    Science.gov (United States)

    Huppert, Doreen; Benson, Judy; Brandt, Thomas

    2017-01-01

    Seasickness and its triggers, symptoms, and preventive measures were well known in antiquity. This chapter is based on an analysis of descriptions of motion sickness, in particular seasickness, in ancient Greek, Roman, and Chinese literature. A systematic search was made from the Greek period beginning with Homer in 800 BC to the late Roman period and ending with Aetios Amidenos in 600 AD, as well as in the Chinese medical classics dating from around 300 AD. Major aspects are the following: body movements caused by waves were identified in all cultures as the critical stimuli. The ancient Greeks and Romans knew that other illnesses and the mental state could precipitate seasickness and that experienced sailors were highly resistant to it (habituation). The Chinese observed that children were particularly susceptible to motion sickness; they first described the type of motion sickness induced by traveling in carts (cart-sickness) or being transported on a litter or in a sedan chair (litter-sickness). The western classics recommended therapeutic measures like fasting or specific diets, pleasant fragrancies, medicinal plants like white hellebore (containing various alkaloids), or a mixture of wine and wormwood. The East knew more unusual measures, such as drinking the urine of young boys, swallowing white sand-syrup, collecting water drops from a bamboo stick, or hiding earth from the kitchen hearth under the hair. The Greek view of the pathophysiology of seasickness was based on the humoral theory of Empedokles and Aristoteles and differed from the Chinese medicine of correspondences, which attributed malfunctions to certain body substances and the life force Qi. Many sources emphasized the impact of seasickness on military actions and famous naval battles such as the Battle of the Red Cliff, which marked the end of the Han dynasty in China, or the defeat of the Spanish Armada by the English in 1588. A peculiar form of motion sickness is associated with Napoleon

  12. NASA-Navy Telemedicine: Autogenic Feedback Training Exercises for Motion Sickness

    Science.gov (United States)

    Acromite, Michael T.; Cowings, Patricia; Toscano, William; Davis, Carl; Porter, Henry O.

    2010-01-01

    Airsickness is the most significant medical condition affecting naval aviation training. A 2001 study showed that airsickness was reported in 81% of naval aviation students and was associated with 82% of below average flight scores. The cost to a single training air-wing was over $150,000 annually for fuel and maintenance costs alone. Resistent cases are sent to the Naval Aerospace Medical Institute (NAMI) for evaluation and desensitization in the self-paced airsickness desensitization (SPAD) program. This approach is 75% successful, but can take up to 8 weeks at a significant travel cost. NASA Ames Research Center's Autogenic Feedback Training Exercises (AFTE) uses physiological and biofeedback training for motion sickness prevention. It has a remote capability that has been used from Moffett Field, CA to Atlanta, GA . AFTE is administered in twelve (30-minute) training sessions. The success rate for the NASA AFTE program has been over 85%. Methods: Implementation Phases: Phase I: Transfer NASA AFTE to NAMI; NASA will remotely train aviation students at NAMI. Phase II: NAMI-centered AFTE application with NASA oversight. Phase III: NAMI-centered AFTE to remotely train at various Navy sites. Phase IV: NAMI to offer Tri-service application and examine research opportunities. Results: 1. Use available telemedicine connectivity between NAMI and NASA. 2. Save over $2,000 per student trained. 3. Reduce aviation training attrition. 4. Provide standardization of multi-location motion sickness training. 5. Future tri-service initiatives. 6. Data to NASA and Navy for QA and research opportunities.

  13. Equations of motion in phase space

    International Nuclear Information System (INIS)

    Broucke, R.

    1979-01-01

    The article gives a general review of methods of constructing equations of motion of a classical dynamical system. The emphasis is however on the linear Lagrangian in phase space and the corresponding form of Pfaff's equations of motion. A detailed examination of the problem of changes of variables in phase space is first given. It is shown that the Linear Lagrangian theory falls very naturally out of the classical quadratic Lagrangian theory; we do this with the use of the well-known Lagrange multiplier method. Another important result is obtained very naturally as a by-product of this analysis. If the most general set of 2n variables (coordinates in phase space) is used, the coefficients of the equations of motion are the Poisson Brackets of these variables. This is therefore the natural way of introducing not only Poisson Brackets in Dynamics formulations but also the associated Lie Algebras and their important properties and consequences. We give then several examples to illustrate the first-order equations of motion and their simplicity in relation to general changes of variables. The first few examples are elementary (the harmonic Oscillator) while the last one concerns the motion of a rigid body about a fixed point. In the next three sections we treat the first-order equations of motion as derived from a Linear differential form, sometimes called Birkhoff's equations. We insist on the generality of the equations and especially on the unity of the space-time concept: the time t and the coordinates are here completely identical variables, without any privilege to t. We give a brief review of Cartan's 2-form and the corresponding equations of motion. As an illustration the standard equations of aircraft flight in a vertical plane are derived from Cartan's exterior differential 2-form. Finally we mention in the last section the differential forms that were proposed by Gallissot for the derivation of equations of motion

  14. EEG based time and frequency dynamics analysis of visually induced motion sickness (VIMS).

    Science.gov (United States)

    Arsalan Naqvi, Syed Ali; Badruddin, Nasreen; Jatoi, Munsif Ali; Malik, Aamir Saeed; Hazabbah, Wan; Abdullah, Baharudin

    2015-12-01

    3D movies are attracting the viewers as they can see the objects flying out of the screen. However, many viewers have reported various problems which are usually faced after watching 3D movies. These problems include visual fatigue, eye strain, headaches, dizziness, blurred vision or collectively may be termed as visually induced motion sickness (VIMS). This research focuses on the comparison between 3D passive technology with a conventional 2D technology to find that whether 3D is causing trouble in the viewers or not. For this purpose, an experiment was designed in which participants were randomly assigned to watch 2D or a 3D movie. The movie was specially designed to induce VIMS. The movie was shown for the duration of 10 min to every participant. The electroencephalogram (EEG) data was recorded throughout the session. At the end of the session, participants rated their feelings using simulator sickness questionnaire (SSQ). The SSQ data was analyzed and the ratings of 2D and 3D participants were compared statistically by using a two tailed t test. From the SSQ results, it was found that participants watching 3D movies reported significantly higher symptoms of VIMS (p value EEG data was analyzed by using MATLAB and topographic plots are created from the data. A significant difference has been observed in the frontal-theta power which increases with the passage of time in 2D condition while decreases with time in 3D condition. Also, a decrease in beta power has been found in the temporal lobe of 3D group. Therefore, it is concluded that there are negative effects of 3D movies causing significant changes in the brain activity in terms of band powers. This condition leads to produce symptoms of VIMS in the viewers.

  15. Motion of gas in highly rarefied space

    Science.gov (United States)

    Chirkunov, Yu A.

    2017-10-01

    A model describing a motion of gas in a highly rarefied space received an unlucky number 13 in the list of the basic models of the motion of gas in the three-dimensional space obtained by L.V. Ovsyannikov. For a given initial pressure distribution, a special choice of mass Lagrangian variables leads to the system describing this motion for which the number of independent variables is less by one. Hence, there is a foliation of a highly rarefied gas with respect to pressure. In a strongly rarefied space for each given initial pressure distribution, all gas particles are localized on a two-dimensional surface that moves with time in this space We found some exact solutions of the obtained system that describe the processes taking place inside of the tornado. For this system we found all nontrivial conservation laws of the first order. In addition to the classical conservation laws the system has another conservation law, which generalizes the energy conservation law. With the additional condition we found another one generalized energy conservation law.

  16. Does 3D produce more symptoms of visually induced motion sickness?

    Science.gov (United States)

    Naqvi, Syed Ali Arsalan; Badruddin, Nasreen; Malik, Aamir Saeed; Hazabbah, Wan; Abdullah, Baharudin

    2013-01-01

    3D stereoscopy technology with high quality images and depth perception provides entertainment to its viewers. However, the technology is not mature yet and sometimes may have adverse effects on viewers. Some viewers have reported discomfort in watching videos with 3D technology. In this research we performed an experiment showing a movie in 2D and 3D environments to participants. Subjective and objective data are recorded and compared in both conditions. Results from subjective reporting shows that Visually Induced Motion Sickness (VIMS) is significantly higher in 3D condition. For objective measurement, ECG data is recorded to find the Heart Rate Variability (HRV), where the LF/HF ratio, which is the index of sympathetic nerve activity, is analyzed to find the changes in the participants' feelings over time. The average scores of nausea, disorientation and total score of SSQ show that there is a significant difference in the 3D condition from 2D. However, LF/HF ratio is not showing significant difference throughout the experiment.

  17. Virtual reality body motion induced navigational controllers and their effects on simulator sickness and pathfinding.

    Science.gov (United States)

    Aldaba, Cassandra N; White, Paul J; Byagowi, Ahmad; Moussavi, Zahra

    2017-07-01

    Virtual reality (VR) navigation is usually constrained by plausible simulator sickness (SS) and intuitive user interaction. The paper reports on the use of four different degrees of body motion induced navigational VR controllers, a TiltChair, omni-directional treadmill, a manual wheelchair joystick (VRNChair), and a joystick in relation to a participant's SS occurrence and a controller's intuitive utilization. Twenty young adult participants utilized all controllers to navigate through the same VR task environment in separate sessions. Throughout the sessions, SS occurrence was measured from a severity score by a standard SS questionnaire and from body sway by a center of pressure path length with eyes opened and closed. SS occurrence did not significantly differ among the controllers. However, time spent in VR significantly contributed to SS occurrence; hence, a few breaks to minimize SS should be interjected throughout a VR task. For all task trials, we recorded the participant's travel trajectories to investigate each controller's intuitive utilization from a computed traversed distance. Shorter traversed distances indicated that participants intuitively utilized the TiltChair with a slower speed; while longer traversed distances indicated participants struggled to utilize the omni-directional treadmill with a unnaturalistic stimulation of gait. Therefore, VR navigation should use technologies best suited for the intended age group that minimizes SS, and produces intuitive interactions for the participants.

  18. Vection is the main contributor to motion sickness induced by visual yaw rotation: Implications for conflict and eye movement theories.

    Directory of Open Access Journals (Sweden)

    Suzanne A E Nooij

    Full Text Available This study investigated the role of vection (i.e., a visually induced sense of self-motion, optokinetic nystagmus (OKN, and inadvertent head movements in visually induced motion sickness (VIMS, evoked by yaw rotation of the visual surround. These three elements have all been proposed as contributing factors in VIMS, as they can be linked to different motion sickness theories. However, a full understanding of the role of each factor is still lacking because independent manipulation has proven difficult in the past. We adopted an integrative approach to the problem by obtaining measures of potentially relevant parameters in four experimental conditions and subsequently combining them in a linear mixed regression model. To that end, participants were exposed to visual yaw rotation in four separate sessions. Using a full factorial design, the OKN was manipulated by a fixation target (present/absent, and vection strength by introducing a conflict in the motion direction of the central and peripheral field of view (present/absent. In all conditions, head movements were minimized as much as possible. Measured parameters included vection strength, vection variability, OKN slow phase velocity, OKN frequency, the number of inadvertent head movements, and inadvertent head tilt. Results show that VIMS increases with vection strength, but that this relation varies among participants (R2 = 0.48. Regression parameters for vection variability, head and eye movement parameters were not significant. These results may seem to be in line with the Sensory Conflict theory on motion sickness, but we argue that a more detailed definition of the exact nature of the conflict is required to fully appreciate the relationship between vection and VIMS.

  19. Evaluation of adaptation to visually induced motion sickness based on the maximum cross-correlation between pulse transmission time and heart rate

    Directory of Open Access Journals (Sweden)

    Chiba Shigeru

    2007-09-01

    Full Text Available Abstract Background Computer graphics and virtual reality techniques are useful to develop automatic and effective rehabilitation systems. However, a kind of virtual environment including unstable visual images presented to wide field screen or a head mounted display tends to induce motion sickness. The motion sickness induced in using a rehabilitation system not only inhibits effective training but also may harm patients' health. There are few studies that have objectively evaluated the effects of the repetitive exposures to these stimuli on humans. The purpose of this study is to investigate the adaptation to visually induced motion sickness by physiological data. Methods An experiment was carried out in which the same video image was presented to human subjects three times. We evaluated changes of the intensity of motion sickness they suffered from by a subjective score and the physiological index ρmax, which is defined as the maximum cross-correlation coefficient between heart rate and pulse wave transmission time and is considered to reflect the autonomic nervous activity. Results The results showed adaptation to visually-induced motion sickness by the repetitive presentation of the same image both in the subjective and the objective indices. However, there were some subjects whose intensity of sickness increased. Thus, it was possible to know the part in the video image which related to motion sickness by analyzing changes in ρmax with time. Conclusion The physiological index, ρmax, will be a good index for assessing the adaptation process to visually induced motion sickness and may be useful in checking the safety of rehabilitation systems with new image technologies.

  20. Histaminergic and cholinergic neuron systems in the impairment of human thermoregulation during motion sickness.

    Science.gov (United States)

    Nobel, Gerard; Tribukait, Arne; Mekjavic, Igor B; Eiken, Ola

    2010-05-31

    Motion sickness (MS) exaggerates body cooling during cold-water immersion. The aim of the present study was to investigate whether such MS-induced predisposition to hypothermia is influenced by two anti-MS drugs: the histamine-receptor blocker dimenhydrinate (DMH) and the muscarine-receptor blocker scopolamine (Scop). Nine healthy male subjects were immersed in 15 degrees C water for a maximum of 90min in five conditions: (1) control (CN): no medication, no MS provocation; (2) MS-control (MS-CN): no medication, MS provocation; (3) MS-placebo (MS-P): placebo DMH and placebo Scop, MS provocation; (4) MS-DMH: DMH and placebo Scop, MS provocation; (5) MS-Scop: Scop and placebo DMH, MS provocation. MS was induced by use of a rotating chair. Throughout the experiments rectal temperature (T(re)), the difference in temperature between the non-immersed right forearm and third finger (T(ff)) as an index of peripheral vasoconstriction, and oxygen uptake (VO(2)) as a measure of shivering thermogenesis, were recorded. DMH and Scop were similarly efficacious in ameliorating nausea. The fall in T(re) was greater in the MS-CN and MS-P conditions than in the CN condition. DMH, but not Scop, prevented the MS-induced increase in body-core cooling. MS attenuated the cold-induced vasoconstriction, an effect which was fully prevented by DMH but only partially by Scop. MS provocation did not affect VO(2) in any condition. The results suggest that the MS-induced predisposition to hypothermia is predominantly mediated by histaminergic mechanisms and that DMH might be useful in conjunction with maritime accidents or other scenarios where exposure to cold and MS are imminent features. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  1. Bromide space, total body water, and sick cell syndrome

    International Nuclear Information System (INIS)

    Schober, O.; Hundeshagen, H.; Lehr, L.

    1982-01-01

    Displacements of the bromide space (Br-82-C, as a marker for the extracellular fluid compartment) are caused by an enhanced anatomical space and/or increased permeability of cells to bromide. The ratio Br-82-C: total body water (TBW) was evaluated to be 0.83 +- 0.17 in critically ill patients (n = 38) compared with the normal value of 0.46 +- 0.04 (n = 10). Because of normal TBW in critically ill patients (TBW = 505 +- 68 ml/kg), an increased bromide penetration into cells seems to be responsible for the enlarged ratio Br-82-C: TBW. Taking into consideration measurements in patients with malabsorption (Br-82-C: TBW = 0.56 +- 0.13; n = 13) and carcinoma of the rectum and colon (Br-82-C: TBW = 0.66 +- 0.24; n = 18) we think that the bromide space is a good measurement of the effective extracellular water. (orig.)

  2. An Evaluation of the Frequency and Severity of Motion Sickness Incidences in Personnel Within the Command and Control Vehicle (C2V)

    Science.gov (United States)

    Cowings, Patricia S.; Toscano, William B.; DeRoshia, Charles

    1998-01-01

    The purpose of this study was to assess the frequency and severity of motion sickness in personnel during a field exercise in the Command and Control Vehicle (C2V). This vehicle contains four workstations where military personnel are expected to perform command decisions in the field during combat conditions. Eight active duty military men (U.S. Army) at the Yuma Proving Grounds in Arizona participated in this study. All subjects were given baseline performance tests while their physiological responses were monitored on the first day. On the second day of their participation, subjects rode in the C2V while their physiological responses and performance measures were recorded. Self-reports of motion sickness were also recorded. Results showed that only one subject experienced two incidences of emesis. However, seven out of the eight subjects reported other motion sickness symptoms; most predominant was the report of drowsiness, which occurred a total of 19 times. Changes in physiological responses were observed relative to motion sickness symptoms reported and the different environmental conditions (i.e., level, hills, gravel) during the field exercise. Performance data showed an overall decrement during the C2V exercise. These findings suggest that malaise and severe drowsiness can potentially impact the operational efficiency of the C2V crew. It was concluded that conflicting sensory information from the subject's visual displays and movements of the vehicle during the field exercise significantly contributed to motion sickness symptoms. It was recommended that a second study be conducted to further evaluate the impact of seat position or orientation and C2V experience on motion sickness susceptibility. Further, it was recommended that an investigation be performed on behavioral methods for improving crew alertness, motivation, and performance and for reducing malaise.

  3. Evaluation of ride-quality and incidence of seasickness. 4. Motion sickness incidence and change of facial expression; Senpaku no norigokochi hyoka ni kansuru kenkyu ( 4 ). Norimonoyoi hasshoji no hyojo no henka

    Energy Technology Data Exchange (ETDEWEB)

    Arima, M.; Hirai, T.; Hosoda, R. [Osaka City Univ. (Japan)

    1998-12-31

    This paper studies the method of predicting and evaluating the motion sickness incidence from subject`s facial expressions during the whole-body exposure to oscillations. The facial expressions are recorded with a video camera which can measure them without invasion physiologically and mentally. Facial parameters, which are considered to relate to the motion sickness incidence, are selected, measured and analyzed quantitatively, and a method of evaluating the motion sickness incidence objectively from the facial expressions is proposed. Three facial expression parameters now selected to evaluate the motion sickness incidence are brow width, eye opening and mouth opening. It was clarified that the motion sickness incidence could be expressed joining the above parameters together. This paper consists of three sections, viz. Oscillation experiment for ride-quality evaluation, Measurement and analysis of facial expressions, and Modeling for evaluating facial expressions. 11 refs., 5 figs., 5 tabs.

  4. Artifacts produced during electrical stimulation of the vestibular nerve in cats. [autonomic nervous system components of motion sickness

    Science.gov (United States)

    Tang, P. C.

    1973-01-01

    Evidence is presented to indicate that evoked potentials in the recurrent laryngeal, the cervical sympathetic, and the phrenic nerve, commonly reported as being elicited by vestibular nerve stimulation, may be due to stimulation of structures other than the vestibular nerve. Experiments carried out in decerebrated cats indicated that stimulation of the petrous bone and not that of the vestibular nerve is responsible for the genesis of evoked potentials in the recurrent laryngeal and the cervical sympathetic nerves. The phrenic response to electrical stimulation applied through bipolar straight electrodes appears to be the result of stimulation of the facial nerve in the facial canal by current spread along the petrous bone, since stimulation of the suspended facial nerve evoked potentials only in the phrenic nerve and not in the recurrent laryngeal nerve. These findings indicate that autonomic components of motion sickness represent the secondary reactions and not the primary responses to vestibular stimulation.

  5. Reassessment of area postrema's role in motion sickness and conditioned taste aversion

    Science.gov (United States)

    Daunton, Nancy G.; Brizzee, Kenneth R.; Corcoran, Meryl Lee; Crampton, G. H.; Damelio, F.; Elfar, S.; Fox, Robert A.

    1991-01-01

    On the basis of classical studies on the role of the area psotrema (AP) in motion-induced emesis it was generally accepted that the AP is an essential structure for the production of vomiting in response to motion. However, in more recent studies it has been demonstrated that vomiting induced by motion can still occur in animals in which the AP has been destroyed bilaterally. It was inferred from some of these more recent studies that the AP plays no role in motion-induced emesis. From the standpoint of the current understanding of central nervous system (CNS) plasticity, redundancy, remodeling, unmasking, regeneration, and recovery of function, however, it is important to realize the limitations of using ablation procedures to determine the functional role of a given neural structure in a highly integrated, adaptable central nervous system (CNS). For example, the results of our recent investigations in cat and squirrel monkey on the role of the AP in emesis and conditioned taste aversion induced by motion indicate that while AP lesions do not prevent motion-induced emesis when animals are tested 30 days or more after surgery, the lesions do change the latency to emesis. Thus, contradictory findings from lesion studies must be evaluated not only in terms of species difference, differences in lesioning techniques and extent of lesions, and in stimulus parameters, but also in terms of duration of the recovery period, during which significant recovery of function may take place. In our judgment, inadequate consideration of the foregoing factors could lead to erroneous inferences about given structure's role in the behavior of the intact, nonablated animal.

  6. The Verriest Lecture: Color lessons from space, time, and motion

    Science.gov (United States)

    Shevell, Steven K.

    2012-01-01

    The appearance of a chromatic stimulus depends on more than the wavelengths composing it. The scientific literature has countless examples showing that spatial and temporal features of light influence the colors we see. Studying chromatic stimuli that vary over space, time or direction of motion has a further benefit beyond predicting color appearance: the unveiling of otherwise concealed neural processes of color vision. Spatial or temporal stimulus variation uncovers multiple mechanisms of brightness and color perception at distinct levels of the visual pathway. Spatial variation in chromaticity and luminance can change perceived three-dimensional shape, an example of chromatic signals that affect a percept other than color. Chromatic objects in motion expose the surprisingly weak link between the chromaticity of objects and their physical direction of motion, and the role of color in inducing an illusory motion direction. Space, time and motion – color’s colleagues – reveal the richness of chromatic neural processing. PMID:22330398

  7. Autonomous Motion Learning for Intra-Vehicular Activity Space Robot

    Science.gov (United States)

    Watanabe, Yutaka; Yairi, Takehisa; Machida, Kazuo

    Space robots will be needed in the future space missions. So far, many types of space robots have been developed, but in particular, Intra-Vehicular Activity (IVA) space robots that support human activities should be developed to reduce human-risks in space. In this paper, we study the motion learning method of an IVA space robot with the multi-link mechanism. The advantage point is that this space robot moves using reaction force of the multi-link mechanism and contact forces from the wall as space walking of an astronaut, not to use a propulsion. The control approach is determined based on a reinforcement learning with the actor-critic algorithm. We demonstrate to clear effectiveness of this approach using a 5-link space robot model by simulation. First, we simulate that a space robot learn the motion control including contact phase in two dimensional case. Next, we simulate that a space robot learn the motion control changing base attitude in three dimensional case.

  8. Adaptive Changes in Sensorimotor Coordination and Motion Sickness Following Repeated Exposures to Virtual Environments

    Science.gov (United States)

    Harm, D. L.; Taylor, L. C.; Bloomberg, J. J.

    2007-01-01

    Virtual environments offer unique training opportunities, particularly for training astronauts and preadapting them to the novel sensory conditions of microgravity. Two unresolved human factors issues in virtual reality (VR) systems are: 1) potential "cybersickness", and 2) maladaptive sensorimotor performance following exposure to VR systems. Interestingly, these aftereffects are often quite similar to adaptive sensorimotor responses observed in astronauts during and/or following space flight. Initial interpretation of novel sensory information may be inappropriate and result in perceptual errors. Active exploratory behavior in a new environment, with resulting feedback and the formation of new associations between sensory inputs and response outputs, promotes appropriate perception and motor control in the new environment. Thus, people adapt to consistent, sustained alterations of sensory input such as those produced by microgravity, unilateral labyrinthectomy and experimentally produced stimulus rearrangements. The purpose of this research was to compare disturbances in sensorimotor coordination produced by dome and head-mounted virtual environment displays and to examine the effects of exposure duration, and repeated exposures to VR systems. The first study examined disturbances in balance control, and the second study examined disturbances in eye-head-hand (EHH) and eye-head coordination.

  9. Differential Gene Expression Profile in the Rat Caudal Vestibular Nucleus is Associated with Individual Differences in Motion Sickness Susceptibility.

    Directory of Open Access Journals (Sweden)

    Jun-Qin Wang

    Full Text Available To identify differentially expressed genes associated with motion sickness (MS susceptibility in the rat caudal vestibular nucleus.We identified MS susceptible (MSS and insusceptible (inMSS rats by quantifying rotation-induced MS symptoms: defecation and spontaneous locomotion activity. Microarray analysis was used to screen differentially expressed genes in the caudal vestibular nucleus (CVN after rotation. Plasma stress hormones were identified by radioimmunoassay. Candidate genes were selected by bioinformatics analysis and the microarray results were verified by real-time quantitative-PCR (RT-qPCR methods. By using Elvax implantation, receptor antagonists or recombinant adenovirus targeting the candidate genes were applied to the CVN to evaluate their contribution to MS susceptibility variability. Validity of gene expression manipulation was verified by RT-qPCR and western blot analysis.A total of 304 transcripts were differentially expressed in the MSS group compared with the inMSS group. RT-qPCR analysis verified the expression pattern of candidate genes, including nicotinic cholinergic receptor (nAchR α3 subunit, 5-hydroxytryptamine receptor 4 (5-HT4R, tachykinin neurokinin-1 (NK1R, γ-aminobutyric acid A receptor (GABAAR α6 subunit, olfactory receptor 81 (Olr81 and homology 2 domain-containing transforming protein 1 (Shc1. In MSS animals, the nAchR antagonist mecamylamine significantly alleviated rotation-induced MS symptoms and the plasma β-endorphin response. The NK1R antagonist CP99994 and Olr81 knock-down were effective for the defecation response, while the 5-HT4R antagonist RS39604 and Shc1 over-expression showed no therapeutic effect. In inMSS animals, rotation-induced changes in spontaneous locomotion activity and the plasma β-endorphin level occurred in the presence of the GABAAR antagonist gabazine.Our findings suggested that the variability of the CVN gene expression profile after motion stimulation might be a putative

  10. Space and motion in nature and Scripture: Galileo, Descartes, Newton.

    Science.gov (United States)

    Janiak, Andrew

    2015-06-01

    In the Scholium to the Definitions in Principia mathematica, Newton departs from his main task of discussing space, time and motion by suddenly mentioning the proper method for interpreting Scripture. This is surprising, and it has long been ignored by scholars. In this paper, I argue that the Scripture passage in the Scholium is actually far from incidental: it reflects Newton's substantive concern, one evident in correspondence and manuscripts from the 1680s, that any general understanding of space, time and motion must enable readers to recognize the veracity of Biblical claims about natural phenomena, including the motion of the earth. This substantive concern sheds new light on an aspect of Newton's project in the Scholium. It also underscores Newton's originality in dealing with the famous problem of reconciling theological and philosophical conceptions of nature in the seventeenth century. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. One-carrier free space charge motion under applied voltage

    International Nuclear Information System (INIS)

    Camargo, P.C.; Ferreira, G.F.L.

    1976-01-01

    The system of partial differential equations describing the one-carrier free space-charge motion under a given applied voltage is transformed into a system of two ordinary differential equations. The method is applied to find the external current injection [pt

  12. Motion perception during tilt and translation after space flight

    Science.gov (United States)

    Clément, Gilles; Wood, Scott J.

    2013-11-01

    Preliminary results of an ongoing study examining the effects of space flight on astronauts' motion perception induced by independent tilt and translation motions are presented. This experiment used a sled and a variable radius centrifuge that translated the subjects forward-backward or laterally, and simultaneously tilted them in pitch or roll, respectively. Tests were performed on the ground prior to and immediately after landing. The astronauts were asked to report about their perceived motion in response to different combinations of body tilt and translation in darkness. Their ability to manually control their own orientation was also evaluated using a joystick with which they nulled out the perceived tilt while the sled and centrifuge were in motion. Preliminary results confirm that the magnitude of perceived tilt increased during static tilt in roll after space flight. A deterioration in the crewmember to control tilt using non-visual inertial cues was also observed post-flight. However, the use of a tactile prosthesis indicating the direction of down on the subject's trunk improved manual control performance both before and after space flight.

  13. Quantum Deformations and Superintegrable Motions on Spaces with Variable Curvature

    Directory of Open Access Journals (Sweden)

    Orlando Ragnisco

    2007-02-01

    Full Text Available An infinite family of quasi-maximally superintegrable Hamiltonians with a common set of (2N-3 integrals of the motion is introduced. The integrability properties of all these Hamiltonians are shown to be a consequence of a hidden non-standard quantum sl(2,R Poisson coalgebra symmetry. As a concrete application, one of this Hamiltonians is shown to generate the geodesic motion on certain manifolds with a non-constant curvature that turns out to be a function of the deformation parameter z. Moreover, another Hamiltonian in this family is shown to generate geodesic motions on Riemannian and relativistic spaces all of whose sectional curvatures are constant and equal to the deformation parameter z. This approach can be generalized to arbitrary dimension by making use of coalgebra symmetry.

  14. One-carrier free space charge motion under applied voltage

    Energy Technology Data Exchange (ETDEWEB)

    de ALMEIDA, L E.C.; FERREIRA, G F.L. [SAO PAULO UNIV., SAO CARLOS (BRAZIL). INSTITUTO DE FISICA E QUIMICA

    1975-12-01

    It is shown how to transform the system of partial differential equations, describing the free one-carrier space charge motion in solid dielectrics under a given applied voltage and while the charge distribution touches only one of the electrodes, into a first order ordinary differential equation from whose solution all the interesting quantities may be easily derived. It was found that some charge distributions can display current reversal.

  15. Autogenic Feedback Training Applications for Man in Space

    Science.gov (United States)

    Cowings, Patricia S.; Wade, Charles E. (Technical Monitor)

    1994-01-01

    Finding an effective treatment for the motion sickness-like symptoms that occur in space has become a high priority for NASA. This paper reviews the back-round research and procedures of an experiment designed to prevent space motion sickness in shuttle crewmembers. The preventive method used, Autogenic - Feedback Training (AFT) involves training subjects to control voluntarily several of their own physiological responses to environmental stressors. AFT has been used reliably to increase tolerance to motion sickness during around based tests in over 300 men and women under a variety of conditions that induce motion sickness, and preliminary evidence from space suggests that AFT may be an effective treatment for space motion sickness as well. Other applications of AFT described include; (1) a potential treatment for post flight orthostatic intolerance, a serious biomedical problem resulting from long duration exposure to micro-g and (2) improving pilot performance during emergency flying conditions.

  16. Desdemona and a ticket to space; training for space flight in a 3g motion simulator

    NARCIS (Netherlands)

    Wouters, M.

    2014-01-01

    On October 5, 2013, Marijn Wouters and two other contestants of a nation-wide competition ‘Nederland Innoveert’ underwent a space training exercise. One by one, the trainees were pushed to their limits in the Desdemona motion simulator, an experience that mimicked the Space Expedition Corporation

  17. Digital Motion Imagery, Interoperability Challenges for Space Operations

    Science.gov (United States)

    Grubbs, Rodney

    2012-01-01

    With advances in available bandwidth from spacecraft and between terrestrial control centers, digital motion imagery and video is becoming more practical as a data gathering tool for science and engineering, as well as for sharing missions with the public. The digital motion imagery and video industry has done a good job of creating standards for compression, distribution, and physical interfaces. Compressed data streams can easily be transmitted or distributed over radio frequency, internet protocol, and other data networks. All of these standards, however, can make sharing video between spacecraft and terrestrial control centers a frustrating and complicated task when different standards and protocols are used by different agencies. This paper will explore the challenges presented by the abundance of motion imagery and video standards, interfaces and protocols with suggestions for common formats that could simplify interoperability between spacecraft and ground support systems. Real-world examples from the International Space Station will be examined. The paper will also discuss recent trends in the development of new video compression algorithms, as well likely expanded use of Delay (or Disruption) Tolerant Networking nodes.

  18. Supersymmetries and constants of motion in spinning spaces

    International Nuclear Information System (INIS)

    Visinescu, Mihai

    1999-01-01

    The models of relativistic particles with spin have been proposed for a long time. The first published work concerning the Lagrangian description of the relativistic particle with spin was the paper by Frenkel which appeared in 1926. After that the literature on the particle with spin grew vast. The models involving only conventional coordinates are called the classical models while the models involving anticommuting (Grassmann) coordinates are generally called pseudo-classical. We shall confine ourselves to discuss the relativistic spin one half particle models involving anticommuting vectorial degrees of freedom which are usually called spinning particles. Spinning particles are in some sense the classical limit of the Dirac particles. After the first quantization these new anticommuting variables are mapped into the Dirac matrices and they disappear from the theory. We investigate the motion of pseudo-classical spinning point particles in curved spaces. The generalized Killing equations for the configuration space of spinning particles (spinning space) are analyzed and the solutions are expressed in terms of Killing-Yano tensors. The general results are applied to the case of the four-dimensional Euclidean Taub-NUT spinning space. (author)

  19. A New Perspective in the Etiology, Treatment, Prevention and Prediction of Space Motion Sickness

    Science.gov (United States)

    1988-12-01

    agents (e.g. scopolamine and promethazine) and psychological techniques (e.g. biofeedback, desensization and autogenic therapy). Three different...26:36). The objective of this approach is to be able to alter psychophysiologic functions. and includes such techniques as biofeedback, autogenic ...therapy, hypnosis, desensitization therapy, and meditation . A common and key attribute in the psychophysiological approach is relaxation. NASA

  20. Human otolith-ocular reflexes during off-vertical axis rotation: effect of frequency on tilt-translation ambiguity and motion sickness

    Science.gov (United States)

    Wood, Scott J.; Paloski, W. H. (Principal Investigator)

    2002-01-01

    The purpose of this study was to examine how the modulation of tilt and translation otolith-ocular responses during constant velocity off-vertical axis rotation varies as a function of stimulus frequency. Eighteen human subjects were rotated in darkness about their longitudinal axis 30 degrees off-vertical at stimulus frequencies between 0.05 and 0.8 Hz. The modulation of torsion decreased while the modulation of horizontal slow phase velocity (SPV) increased with increasing frequency. It is inferred that the ambiguity of otolith afferent information is greatest in the frequency region where tilt (torsion) and translational (horizontal SPV) otolith-ocular responses crossover. It is postulated that the previously demonstrated peak in motion sickness susceptibility during linear accelerations around 0.3 Hz is the result of frequency segregation of ambiguous otolith information being inadequate to distinguish between tilt and translation.

  1. Time and space: undergraduate Mexican physics in motion

    Science.gov (United States)

    Candela, Antonia

    2010-09-01

    This is an ethnographic study of the trajectories and itineraries of undergraduate physics students at a Mexican university. In this work learning is understood as being able to move oneself and, other things (cultural tools), through the space-time networks of a discipline (Nespor in Knowledge in motion: space, time and curriculum in undergraduate physics and management. Routledge Farmer, London, 1994). The potential of this socio-cultural perspective allows an analysis of how students are connected through extended spaces and times with an international core discipline as well as with cultural features related to local networks of power and construction. Through an example, I show that, from an actor-network-theory (Latour in Science in action. Harvard University Press, Cambridge, 1987), that in order to understand the complexities of undergraduate physics processes of learning you have to break classroom walls and take into account students' movements through complex spatial and temporal traces of the discipline of physics. Mexican professors do not give classes following one textbook but in a moment-to-moment open dynamism tending to include undergraduate students as actors in classroom events extending the teaching space-time of the classroom to the disciplinary research work of physics. I also find that Mexican undergraduate students show initiative and display some autonomy and power in the construction of their itineraries as they are encouraged to examine a variety of sources including contemporary research articles, unsolved physics problems, and even to participate in several physicists' spaces, as for example being speakers at the national congresses of physics. Their itineraries also open up new spaces of cultural and social practices, creating more extensive networks beyond those associated with a discipline. Some economic, historical and cultural contextual features of this school of sciences are analyzed in order to help understanding the particular

  2. Car Sickness

    Science.gov (United States)

    ... Preventable Diseases Healthy Children > Health Issues > Conditions > Head Neck & Nervous System > Car Sickness Health Issues Listen Español Text Size Email Print Share Car Sickness Page Content ...

  3. Sick of Taxes?

    DEFF Research Database (Denmark)

    Ljunge, Jan Martin

    I estimate a price elasticity of sickness absence. Sick leave is an intensive margin of labor supply where individuals are free to adjust. I exploit variation in tax rates over two decades, which provide thousands of differential incentives across time and space, to estimate the price responsiven...... of sick leave, -0.7, with respect to the net of tax rate. Though large relative to traditional labor supply elasticities, Swedes are half as price elastic as bike messengers, and just as elastic as stadium vendors on the margin which they can adjust freely....

  4. Modeling a space-variant cortical representation for apparent motion.

    Science.gov (United States)

    Wurbs, Jeremy; Mingolla, Ennio; Yazdanbakhsh, Arash

    2013-08-06

    Receptive field sizes of neurons in early primate visual areas increase with eccentricity, as does temporal processing speed. The fovea is evidently specialized for slow, fine movements while the periphery is suited for fast, coarse movements. In either the fovea or periphery discrete flashes can produce motion percepts. Grossberg and Rudd (1989) used traveling Gaussian activity profiles to model long-range apparent motion percepts. We propose a neural model constrained by physiological data to explain how signals from retinal ganglion cells to V1 affect the perception of motion as a function of eccentricity. Our model incorporates cortical magnification, receptive field overlap and scatter, and spatial and temporal response characteristics of retinal ganglion cells for cortical processing of motion. Consistent with the finding of Baker and Braddick (1985), in our model the maximum flash distance that is perceived as an apparent motion (Dmax) increases linearly as a function of eccentricity. Baker and Braddick (1985) made qualitative predictions about the functional significance of both stimulus and visual system parameters that constrain motion perception, such as an increase in the range of detectable motions as a function of eccentricity and the likely role of higher visual processes in determining Dmax. We generate corresponding quantitative predictions for those functional dependencies for individual aspects of motion processing. Simulation results indicate that the early visual pathway can explain the qualitative linear increase of Dmax data without reliance on extrastriate areas, but that those higher visual areas may serve as a modulatory influence on the exact Dmax increase.

  5. Wavelet-space correlation imaging for high-speed MRI without motion monitoring or data segmentation.

    Science.gov (United States)

    Li, Yu; Wang, Hui; Tkach, Jean; Roach, David; Woods, Jason; Dumoulin, Charles

    2015-12-01

    This study aims to (i) develop a new high-speed MRI approach by implementing correlation imaging in wavelet-space, and (ii) demonstrate the ability of wavelet-space correlation imaging to image human anatomy with involuntary or physiological motion. Correlation imaging is a high-speed MRI framework in which image reconstruction relies on quantification of data correlation. The presented work integrates correlation imaging with a wavelet transform technique developed originally in the field of signal and image processing. This provides a new high-speed MRI approach to motion-free data collection without motion monitoring or data segmentation. The new approach, called "wavelet-space correlation imaging", is investigated in brain imaging with involuntary motion and chest imaging with free-breathing. Wavelet-space correlation imaging can exceed the speed limit of conventional parallel imaging methods. Using this approach with high acceleration factors (6 for brain MRI, 16 for cardiac MRI, and 8 for lung MRI), motion-free images can be generated in static brain MRI with involuntary motion and nonsegmented dynamic cardiac/lung MRI with free-breathing. Wavelet-space correlation imaging enables high-speed MRI in the presence of involuntary motion or physiological dynamics without motion monitoring or data segmentation. © 2014 Wiley Periodicals, Inc.

  6. Supersymmetries and constants of motion in Taub-NUT spinning space

    International Nuclear Information System (INIS)

    Vaman, D.; Visinescu, M.

    1998-01-01

    Models of relativistic particles with spin have been proposed for a long time. The models involving only conventional coordinates are called classical, while the models involving anticommuting coordinates are generally called pseudo-classical. In this paper, the relativistic spin one half particle models involving anticommuting vectorial degrees of freedom, which are usually called the spinning particles, are considered. Spinning particles are in some sense the classical limit of the Dirac particles. After the first quantization these new anticommuting variables are mapped into the Dirac matrices and they disappear from the theory. In the present paper, the motion of pseudo-classical spinning particles in curved spaces is investigated and the relevant equations of motion are investigated. The generalized Killing equations for the configuration space of spinning particles (spinning spaces) are discussed and the constants of motion are derived in terms of the solutions of these equations. We also analysed the motion of pseudo-classical spinning particles in the Euclidean Taub-NUT space. The generalized Killing equations for this spinning space are examined and derivation of the constants of motion in terms of the Killing-Yano tensors is described. The equations obtained for the special case of motion on cone are solved. This case represents an extension of the scalar particle motions in the usual Taub-NUT space in which the orbits are conic sections. An explicit exact solution is given. In spite of its simplicity, this solution occurs to be far from trivial. (authors)

  7. Serum sickness

    Science.gov (United States)

    ... the problem should be stopped. Avoid using that medicine or antiserum in the future. ... Call your provider if you received medicine or antiserum in the last 4 weeks and have symptoms of serum sickness.

  8. Morning sickness

    Science.gov (United States)

    ... not predict how you will feel in future pregnancies. Causes The exact cause of morning sickness is unknown. It may be caused by hormone changes or lower blood sugar during early pregnancy. Emotional stress, fatigue, traveling, or some foods can ...

  9. Radiation sickness

    International Nuclear Information System (INIS)

    Endoh, Masaru; Ishida, Yusei; Saeki, Mitsuaki

    1983-01-01

    The frequency of radiation sickness in 1,060 patients treated at our Department was 12.8 percent. It was frequent in patients with brain cancer (12 percent), whole spine cancer (47 percent), uterus cancer (28 percent), lung cancer (22 percent) and esophagus cancer (12 percent). Radiation sickness following X-irradiation was studied in its relation to patient's age, size of radiation fields, dosis and white blood cell count. However, we could not find any definite clinical feature relevant to occurrence. There are many theories published concerning the mechanism of radiation sickness. Clinical experiences have shown that radiation sickness cannot be explained by one theory alone but by several theories such as those based on psychology, stress or histamine. (author)

  10. Motion tracking in narrow spaces: a structured light approach

    DEFF Research Database (Denmark)

    Olesen, Oline Vinter; Paulsen, Rasmus; Højgaard, Liselotte

    2010-01-01

    We present a novel tracking system for patient head motion inside 3D medical scanners. Currently, the system is targeted at the Siemens High Resolution Research Tomograph (HRRT) PET scanner. Partial face surfaces are reconstructed using a miniaturized structured light system. The reconstructed 3D...... the system to a standard optical motion tracker based on a rigid tracking tool. Our system achieves an angular RMSE of 0.11 degrees demonstrating its relevance for motion compensated 3D scan image reconstructions as well as its competitiveness against the standard optical system with an RMSE of 0.08 degrees...... point clouds are matched to a reference surface using a robust iterative closest point algorithm. A main challenge is the narrow geometry requiring a compact structured light system and an oblique angle of observation. The system is validated using a mannequin head mounted on a rotary stage. We compare...

  11. Three dimensional monocular human motion analysis in end-effector space

    DEFF Research Database (Denmark)

    Hauberg, Søren; Lapuyade, Jerome; Engell-Nørregård, Morten Pol

    2009-01-01

    In this paper, we present a novel approach to three dimensional human motion estimation from monocular video data. We employ a particle filter to perform the motion estimation. The novelty of the method lies in the choice of state space for the particle filter. Using a non-linear inverse kinemati...

  12. Non-Noether conserved quantity for differential equations of motion in the phase space

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A non-Noether conserved quantity for the differential equations of motion of mechanical systems in the phase space is studied. The differential equations of motion of the systems are established and the determining equations of Lie symmetry are given. An existence theorem of non-Noether conserved quantity is obtained. An example is given to illustrate the application of the result.

  13. Motion tracking in narrow spaces: A structured light approach

    DEFF Research Database (Denmark)

    Olesen, Oline Vinter; Paulsen, Rasmus Reinhold; Højgaard, Liselotte

    2010-01-01

    We present a novel tracking system for patient head motion inside 3D medical scanners. Currently, the system is targeted at the Siemens High Resolution Research Tomograph (HRRT) PET scanner. Partial face surfaces are reconstructed using a miniaturized structured light system. The reconstructed 3D...

  14. Attitude Motion of Cylindrical Space Debris during Its Removal by Ion Beam

    Directory of Open Access Journals (Sweden)

    Vladimir S. Aslanov

    2017-01-01

    Full Text Available The paper is devoted to the problem of space debris mitigation. Contactless method of the space debris deorbiting is considered. It is assumed that ion thrusters on the active spacecraft create the ion flow, which blows the debris and slows it down. The objectives of this work are the development of mathematical models and the research of space debris motion under the action of the ion flow. It is supposed that the space debris is a rigid body of a cylindrical shape. Calculation of ion beam force and torque was performed for a self-similar model of plasma plume expansion using the hypothesis of ion fully diffused reflection from a surface. A mathematical model describing plane motions of the cylindrical space debris under the influence of gravity gradient torque and the ion flux was constructed. It was shown that motion of the space debris around its center of mass has a significant effect on its removal time. Phase portraits, describing the motion of the space debris relative to its center of mass, were constructed. Comparison of the descent times in different motion modes was carried out. The results can be used to create new effective systems of large space debris removal.

  15. Relativistic algebraic spinors and quantum motions in phase space

    International Nuclear Information System (INIS)

    Holland, P.R.

    1986-01-01

    Following suggestions of Schonberg and Bohm, we study the tensorial phase space representation of the Dirac and Feynman-Gell-Mann equations in terms of the complex Dirac algebra C 4 , a Jordan-Wigner algebra G 4 , and Wigner transformations. To do this we solve the problem of the conditions under which elements in C 4 generate minimal ideals, and extend this to G 4 . This yields the linear theory of Dirac spin spaces and tensor representations of Dirac spinors, and the spin-1/2 wave equations are represented through fermionic state vectors in a higher space as a set of interconnected tensor relations

  16. Planning the Motion of a Robotic Assistant for Space Applications

    Data.gov (United States)

    National Aeronautics and Space Administration — Revolutions in computing hardware and software have brought about an age where robots and people will be able to peacefully and safely co-exist in the same...

  17. Habituation to novel visual vestibular environments with special reference to space flight

    Science.gov (United States)

    Young, L. R.; Kenyon, R. V.; Oman, C. M.

    1981-01-01

    The etiology of space motion sickness and the underlying physiological mechanisms associated with spatial orientation in a space environment were investigated. Human psychophysical experiments were used as the basis for the research concerning the interaction of visual and vestibular cues in the development of motion sickness. Particular emphasis is placed on the conflict theory in terms of explaining these interactions. Research on the plasticity of the vestibulo-ocular reflex is discussed.

  18. Cinerama sickness and postural instability.

    Science.gov (United States)

    Bos, Jelte E; Ledegang, Wietse D; Lubeck, Astrid J A; Stins, John F

    2013-01-01

    Motion sickness symptoms and increased postural instability induced by motion pictures have been reported in a laboratory, but not in a real cinema. We, therefore, carried out an observational study recording sickness severity and postural instability in 19 subjects before, immediately and 45 min after watching a 1 h 3D aviation documentary in a cinema. Sickness was significantly larger right after the movie than before, and in a lesser extent still so after 45 min. The average standard deviation of the lateral centre of pressure excursions was significantly larger only right afterwards. When low-pass filtered at 0.1 Hz, lateral and for-aft excursions were both significantly larger right after the movie, while for-aft excursions then remained larger even after 45 min. Speculating on previous findings, we predict more sickness and postural instability in 3D than in 2D movies, also suggesting a possible, but yet unknown risk for work-related activities and vehicle operation. Watching motion pictures may be sickening and posturally destabilising, but effects in a cinema are unknown. We, therefore, carried out an observational study showing that sickness then is mainly an issue during the exposure while postural instability is an issue afterwards.

  19. Philosophies Applied in the Selection of Space Suit Joint Range of Motion Requirements

    Science.gov (United States)

    Aitchison, Lindsway; Ross, Amy; Matty, Jennifer

    2009-01-01

    Space suits are the most important tool for astronauts working in harsh space and planetary environments; suits keep crewmembers alive and allow them to perform exploration, construction, and scientific tasks on a routine basis over a period of several months. The efficiency with which the tasks are performed is largely dictated by the mobility features of the space suit. For previous space suit development programs, the mobility requirements were written as pure functional mobility requirements that did not separate joint ranges of motion from the joint torques. The Constellation Space Suit Element has the goal to make more quantitative mobility requirements that focused on the individual components of mobility to enable future suit designers to build and test systems more effectively. This paper details the test planning and selection process for the Constellation space suit pressure garment range of motion requirements.

  20. Brownian motion, Minkowski space and principle of special relativity

    International Nuclear Information System (INIS)

    Caubet, J.-P.

    1977-01-01

    From the assumption that the brownian diffusion locally behaves like an ideal gas (pressure being inversely proportional to volume according to Boyle's law) one can deduce the signature +++- of the Minkowski space, the Lorentz addition of velocities, and the principle of special relativity [fr

  1. Climber Motion Optimization for the Tethered Space Elevator

    NARCIS (Netherlands)

    Williams, P.; Ockels, W.J.

    The tethered space elevator could provide a revolutionary means for enabling cheap transportation to geostationary altitude and beyond. Assuming that such a system can be built, one of the dynamic design problems is determining a means of moving the elevator along the tether so as to minimize the

  2. Predicted space motions for hypervelocity and runaway stars: proper motions and radial velocities for the Gaia Era

    Energy Technology Data Exchange (ETDEWEB)

    Kenyon, Scott J.; Brown, Warren R.; Geller, Margaret J. [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Bromley, Benjamin C., E-mail: skenyon@cfa.harvard.edu, E-mail: wbrown@cfa.harvard.edu, E-mail: mgeller@cfa.harvard.edu, E-mail: bromley@physics.utah.edu [Department of Physics, University of Utah, 115 S 1400 E, Rm 201, Salt Lake City, UT 84112 (United States)

    2014-10-01

    We predict the distinctive three-dimensional space motions of hypervelocity stars (HVSs) and runaway stars moving in a realistic Galactic potential. For nearby stars with distances less than 10 kpc, unbound stars are rare; proper motions alone rarely isolate bound HVSs and runaways from indigenous halo stars. At large distances of 20-100 kpc, unbound HVSs are much more common than runaways; radial velocities easily distinguish both from indigenous halo stars. Comparisons of the predictions with existing observations are encouraging. Although the models fail to match observations of solar-type HVS candidates from SEGUE, they agree well with data for B-type HVS and runaways from other surveys. Complete samples of g ≲ 20 stars with Gaia should provide clear tests of formation models for HVSs and runaways and will enable accurate probes of the shape of the Galactic potential.

  3. Range-Space Predictive Control for Optimal Robot Motion

    Czech Academy of Sciences Publication Activity Database

    Belda, Květoslav; Böhm, Josef

    2008-01-01

    Roč. 1, č. 1 (2008), s. 1-7 ISSN 1998-0140 R&D Projects: GA ČR GP102/06/P275 Institutional research plan: CEZ:AV0Z10750506 Keywords : Accurate manipulation * Industrial robotics * Predictive control * Range-space control Subject RIV: BC - Control Systems Theory http://library.utia.cas.cz/separaty/historie/belda-0305644.pdf

  4. Distributed Submodular Minimization And Motion Coordination Over Discrete State Space

    KAUST Repository

    Jaleel, Hassan

    2017-09-21

    Submodular set-functions are extensively used in large-scale combinatorial optimization problems arising in complex networks and machine learning. While there has been significant interest in distributed formulations of convex optimization, distributed minimization of submodular functions has not received significant attention. Thus, our main contribution is a framework for minimizing submodular functions in a distributed manner. The proposed framework is based on the ideas of Lovasz extension of submodular functions and distributed optimization of convex functions. The framework exploits a fundamental property of submodularity that the Lovasz extension of a submodular function is a convex function and can be computed efficiently. Moreover, a minimizer of a submodular function can be computed by computing the minimizer of its Lovasz extension. In the proposed framework, we employ a consensus based distributed optimization algorithm to minimize set-valued submodular functions as well as general submodular functions defined over set products. We also identify distributed motion coordination in multiagent systems as a new application domain for submodular function minimization. For demonstrating key ideas of the proposed framework, we select a complex setup of the capture the flag game, which offers a variety of challenges relevant to multiagent system. We formulate the problem as a submodular minimization problem and verify through extensive simulations that the proposed framework results in feasible policies for the agents.

  5. Sickness presence, sick leave and adjustment latitude

    Directory of Open Access Journals (Sweden)

    Joachim Gerich

    2014-10-01

    Full Text Available Objectives: Previous research on the association between adjustment latitude (defined as the opportunity to adjust work efforts in case of illness and sickness absence and sickness presence has produced inconsistent results. In particular, low adjustment latitude has been identified as both a risk factor and a deterrent of sick leave. The present study uses an alternative analytical strategy with the aim of joining these results together. Material and Methods: Using a cross-sectional design, a random sample of employees covered by the Upper Austrian Sickness Fund (N = 930 was analyzed. Logistic and ordinary least square (OLS regression models were used to examine the association between adjustment latitude and days of sickness absence, sickness presence, and an estimator for the individual sickness absence and sickness presence propensity. Results: A high level of adjustment latitude was found to be associated with a reduced number of days of sickness absence and sickness presence, but an elevated propensity for sickness absence. Conclusions: Employees with high adjustment latitude experience fewer days of health complaints associated with lower rates of sick leave and sickness presence compared to those with low adjustment latitude. In case of illness, however, high adjustment latitude is associated with a higher pro­bability of taking sick leave rather than sickness presence.

  6. Proper Motions of Dwarf Spheroidal Galaxies from Hubble Space Telescope Imaging. IV. Measurement for Sculptor

    Science.gov (United States)

    Piatek, Slawomir; Pryor, Carlton; Bristow, Paul; Olszewski, Edward W.; Harris, Hugh C.; Mateo, Mario; Minniti, Dante; Tinney, Christopher G.

    2006-03-01

    This article presents a measurement of the proper motion of the Sculptor dwarf spheroidal galaxy determined from images taken with the Hubble Space Telescope using the Space Telescope Imaging Spectrograph in the imaging mode. Each of two distinct fields contains a quasi-stellar object that serves as the ``reference point.'' The measured proper motion of Sculptor, expressed in the equatorial coordinate system, is (μα, μδ)=(9+/-13, 2+/-13) mas century-1. Removing the contributions from the motion of the Sun and the motion of the local standard of rest produces the proper motion in the Galactic rest frame: (μGrfα, μGrfδ)=(-23+/-13, 45+/-13) mas century-1. The implied space velocity with respect to the Galactic center has a radial component of Vr=79+/-6 km s-1 and a tangential component of Vt=198+/-50 km s-1. Integrating the motion of Sculptor in a realistic potential for the Milky Way produces orbital elements. The perigalacticon and apogalacticon are 68 (31, 83) and 122 (97, 313) kpc, respectively, where the values in the parentheses represent the 95% confidence interval derived from Monte Carlo experiments. The eccentricity of the orbit is 0.29 (0.26, 0.60), and the orbital period is 2.2 (1.5, 4.9) Gyr. Sculptor is on a polar orbit around the Milky Way: the angle of inclination is 86° (83°, 90°). Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

  7. Brain Activation by H1 Antihistamines Challenges Conventional View of Their Mechanism of Action in Motion Sickness: A Behavioral, c-Fos and Physiological Study in Suncus murinus (House Musk Shrew

    Directory of Open Access Journals (Sweden)

    Longlong Tu

    2017-06-01

    Full Text Available Motion sickness occurs under a variety of circumstances and is common in the general population. It is usually associated with changes in gastric motility, and hypothermia, which are argued to be surrogate markers for nausea; there are also reports that respiratory function is affected. As laboratory rodents are incapable of vomiting, Suncus murinus was used to model motion sickness and to investigate changes in gastric myoelectric activity (GMA and temperature homeostasis using radiotelemetry, whilst also simultaneously investigating changes in respiratory function using whole body plethysmography. The anti-emetic potential of the highly selective histamine H1 receptor antagonists, mepyramine (brain penetrant, and cetirizine (non-brain penetrant, along with the muscarinic receptor antagonist, scopolamine, were investigated in the present study. On isolated ileal segments from Suncus murinus, both mepyramine and cetirizine non-competitively antagonized the contractile action of histamine with pKb values of 7.5 and 8.4, respectively; scopolamine competitively antagonized the contractile action of acetylcholine with pA2 of 9.5. In responding animals, motion (1 Hz, 4 cm horizontal displacement, 10 min increased the percentage of the power of bradygastria, and decreased the percentage power of normogastria whilst also causing hypothermia. Animals also exhibited an increase in respiratory rate and a reduction in tidal volume. Mepyramine (50 mg/kg, i.p. and scopolamine (10 mg/kg, i.p., but not cetirizine (10 mg/kg, i.p., significantly antagonized motion-induced emesis but did not reverse the motion-induced disruptions of GMA, or hypothermia, or effects on respiration. Burst analysis of plethysmographic-derived waveforms showed mepyramine also had increased the inter-retch+vomit frequency, and emetic episode duration. Immunohistochemistry demonstrated that motion alone did not induce c-fos expression in the brain. Paradoxically, mepyramine increased c

  8. Yarkovsky-Schach effect on space debris motion

    Science.gov (United States)

    Murawiecka, M.; Lemaitre, A.

    2018-02-01

    The Yarkovsky-Schach effect is a small perturbation affecting Earth satellites and space debris illuminated by the Sun. It was first applied to the orbit of LAGEOS satellites as an explanation of the residuals in orbital elements. In this work, we carry out several numerical integration tests taking into consideration various orbit and rotation parameters, in order to analyse this effect in a broader context. The semi-major axis variations remain small and depend on the spin axis attitude with respect to the Sun. We show that the force amplitude is maximised for orbits inclined with i ≈ 20-30°. We also observe the influence on other orbital elements, notably on the orbit inclination. However, these effects are clearly observed only on long timescales; in our simulations, we propagated the orbits for 200 y. The Yarkovsky-Schach effect is thus confirmed to have a minuscule magnitude. It should be taken into account in studies requiring high-precision orbit determination, or on expanded timescales.

  9. Effective potential for equatorial motion in the Tomimatsu-Sato space-times

    Energy Technology Data Exchange (ETDEWEB)

    Calvani, M [Padua Univ. (Italy). Ist. di Astronomia

    1978-01-28

    We give general rules to draw the effective potential curves for equatorial motion in the T-S space-times either with am. Some general properties of the potentials are pointed out and few examples shown.

  10. Radiation sickness

    International Nuclear Information System (INIS)

    Chin, A.; Leer, J.W.H.; Craandijk, M.; Feenstra, W.F.F.

    1990-01-01

    In a prospective inventory analysis of 169 irradiated patients concerning the incidence and course of Acute Radiation Sickness (fatigue, loss of appetite, nausea and vomiting), it was found that 2/3 of the patients had these complaints. The complaints started during the first week of treatment and mostly even within a few hours after each radiotherapy session. All complaints were progressive during the radiotherapy course, but disappeared spontaneously within one week after completion of the treatment. The possible occurrence of these symptoms soon after the start of radiotherapy should be kept in mind, especially since they can be reduced by simple retimens. (author). 14 refs.; 2 tabs

  11. Development of a neural net paradigm that predicts simulator sickness

    Energy Technology Data Exchange (ETDEWEB)

    Allgood, G.O.

    1993-03-01

    A disease exists that affects pilots and aircrew members who use Navy Operational Flight Training Systems. This malady, commonly referred to as simulator sickness and whose symptomatology closely aligns with that of motion sickness, can compromise the use of these systems because of a reduced utilization factor, negative transfer of training, and reduction in combat readiness. A report is submitted that develops an artificial neural network (ANN) and behavioral model that predicts the onset and level of simulator sickness in the pilots and aircrews who sue these systems. It is proposed that the paradigm could be implemented in real time as a biofeedback monitor to reduce the risk to users of these systems. The model captures the neurophysiological impact of use (human-machine interaction) by developing a structure that maps the associative and nonassociative behavioral patterns (learned expectations) and vestibular (otolith and semicircular canals of the inner ear) and tactile interaction, derived from system acceleration profiles, onto an abstract space that predicts simulator sickness for a given training flight.

  12. Hybrid task priority-based motion control of a redundant free-floating space robot

    Directory of Open Access Journals (Sweden)

    Cheng ZHOU

    2017-12-01

    Full Text Available This paper presents a novel hybrid task priority-based motion planning algorithm of a space robot. The satellite attitude control task is defined as the primary task, while the least-squares-based non-strict task priority solution of the end-effector plus the multi-constraint task is viewed as the secondary task. Furthermore, a null-space task compensation strategy in the joint space is proposed to derive the combination of non-strict and strict task-priority motion planning, and this novel combination is termed hybrid task priority control. Thus, the secondary task is implemented in the primary task’s null-space. Besides, the transition of the state of multiple constraints between activeness and inactiveness will only influence the end-effector task without any effect on the primary task. A set of numerical experiments made in a real-time simulation system under Linux/RTAI shows the validity and feasibility of the proposed methodology. Keywords: Base attitude control, Hybrid task-priority, Motion planning, Multiple constraints, Redundant space robot

  13. Proper Motions of Dwarf Spheroidal Galaxies from Hubble Space Telescope Imaging. V. Final Measurement for Fornax

    Science.gov (United States)

    Piatek, Slawomir; Pryor, Carlton; Bristow, Paul; Olszewski, Edward W.; Harris, Hugh C.; Mateo, Mario; Minniti, Dante; Tinney, Christopher G.

    2007-03-01

    The measured proper motion of Fornax, expressed in the equatorial coordinate system, is (μα,μδ)=(47.6+/-4.6,-36.0+/-4.1) mas century-1. This proper motion is a weighted mean of four independent measurements for three distinct fields. Each measurement uses a quasi-stellar object as a reference point. Removing the contribution of the motion of the Sun and of the local standard of rest to the measured proper motion produces a Galactic rest-frame proper motion of (μGrfα,μGrfδ)=(24.4+/-4.6,-14.3+/-4.1) mas century-1. The implied space velocity with respect to the Galactic center has a radial component of Vr=-31.8+/-1.7 km s-1 and a tangential component of Vt=196+/-29 km s-1. Integrating the motion of Fornax in a realistic potential for the Milky Way produces orbital elements. The perigalacticon and apogalacticon are 118 (66, 137) and 152 (144, 242) kpc, respectively, where the values in the parentheses represent the 95% confidence intervals derived from Monte Carlo experiments. The eccentricity of the orbit is 0.13 (0.11, 0.38), and the orbital period is 3.2 (2.5, 4.6) Gyr. The orbit is retrograde and inclined by 101° (94°, 107°) to the Galactic plane. Fornax could be a member of a proposed ``stream'' of galaxies and globular clusters; however, the membership of another proposed galaxy in the stream, Sculptor, has been previously ruled out. Fornax is in the Kroupa-Theis-Boily plane, which contains 11 of the Galactic satellite galaxies, but its orbit will take it out of that plane. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

  14. Nearly automatic motion capture system for tracking octopus arm movements in 3D space.

    Science.gov (United States)

    Zelman, Ido; Galun, Meirav; Akselrod-Ballin, Ayelet; Yekutieli, Yoram; Hochner, Binyamin; Flash, Tamar

    2009-08-30

    Tracking animal movements in 3D space is an essential part of many biomechanical studies. The most popular technique for human motion capture uses markers placed on the skin which are tracked by a dedicated system. However, this technique may be inadequate for tracking animal movements, especially when it is impossible to attach markers to the animal's body either because of its size or shape or because of the environment in which the animal performs its movements. Attaching markers to an animal's body may also alter its behavior. Here we present a nearly automatic markerless motion capture system that overcomes these problems and successfully tracks octopus arm movements in 3D space. The system is based on three successive tracking and processing stages. The first stage uses a recently presented segmentation algorithm to detect the movement in a pair of video sequences recorded by two calibrated cameras. In the second stage, the results of the first stage are processed to produce 2D skeletal representations of the moving arm. Finally, the 2D skeletons are used to reconstruct the octopus arm movement as a sequence of 3D curves varying in time. Motion tracking, segmentation and reconstruction are especially difficult problems in the case of octopus arm movements because of the deformable, non-rigid structure of the octopus arm and the underwater environment in which it moves. Our successful results suggest that the motion-tracking system presented here may be used for tracking other elongated objects.

  15. Proper Motions of Dwarf Spheroidal Galaxies from Hubble Space Telescope Imaging. III. Measurement for Ursa Minor

    Science.gov (United States)

    Piatek, Slawomir; Pryor, Carlton; Bristow, Paul; Olszewski, Edward W.; Harris, Hugh C.; Mateo, Mario; Minniti, Dante; Tinney, Christopher G.

    2005-07-01

    This article presents a measurement of the proper motion of the Ursa Minor dwarf spheroidal galaxy determined from images taken with the Hubble Space Telescope in two distinct fields. Each field contains a quasi-stellar object that serves as the ``reference point.'' The measured proper motion for Ursa Minor, expressed in the equatorial coordinate system, is (μα,μδ)=(-50+/-17,22+/-16) mas century-1. Removing the contributions of the solar motion and the motion of the local standard of rest yields the proper motion in the Galactic rest frame: (μGrfα,μGrfδ)=(-8+/-17,38+/-16) mas century-1. The implied space velocity with respect to the Galactic center has a radial component of Vr=-75+/-44 km s-1 and a tangential component of Vt=144+/-50 km s-1. Integrating the motion of Ursa Minor in a realistic potential for the Milky Way produces orbital elements. The perigalacticon and apogalacticon are 40 (10, 76) and 89 (78, 160) kpc, respectively, where the values in the parentheses represent the 95% confidence intervals derived from Monte Carlo experiments. The eccentricity of the orbit is 0.39 (0.09, 0.79), and the orbital period is 1.5 (1.1, 2.7) Gyr. The orbit is retrograde and inclined by 124° (94°, 136°) to the Galactic plane. Ursa Minor is not a likely member of a proposed stream of galaxies on similar orbits around the Milky Way, nor is the plane of its orbit coincident with a recently proposed planar alignment of galaxies around the Milky Way. Comparing the orbits of Ursa Minor and Carina shows no reason for the different star formation histories of these two galaxies. Ursa Minor must contain dark matter to have a high probability of having survived disruption by the Galactic tidal force until the present. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

  16. Motion Perception and Manual Control Performance During Passive Tilt and Translation Following Space Flight

    Science.gov (United States)

    Clement, Gilles; Wood, Scott J.

    2010-01-01

    This joint ESA-NASA study is examining changes in motion perception following Space Shuttle flights and the operational implications of post-flight tilt-translation ambiguity for manual control performance. Vibrotactile feedback of tilt orientation is also being evaluated as a countermeasure to improve performance during a closed-loop nulling task. METHODS. Data has been collected on 5 astronaut subjects during 3 preflight sessions and during the first 8 days after Shuttle landings. Variable radius centrifugation (216 deg/s) combined with body translation (12-22 cm, peak-to-peak) is utilized to elicit roll-tilt perception (equivalent to 20 deg, peak-to-peak). A forward-backward moving sled (24-390 cm, peak-to-peak) with or without chair tilting in pitch is utilized to elicit pitch tilt perception (equivalent to 20 deg, peak-to-peak). These combinations are elicited at 0.15, 0.3, and 0.6 Hz for evaluating the effect of motion frequency on tilt-translation ambiguity. In both devices, a closed-loop nulling task is also performed during pseudorandom motion with and without vibrotactile feedback of tilt. All tests are performed in complete darkness. PRELIMINARY RESULTS. Data collection is currently ongoing. Results to date suggest there is a trend for translation motion perception to be increased at the low and medium frequencies on landing day compared to pre-flight. Manual control performance is improved with vibrotactile feedback. DISCUSSION. The results of this study indicate that post-flight recovery of motion perception and manual control performance is complete within 8 days following short-duration space missions. Vibrotactile feedback of tilt improves manual control performance both before and after flight.

  17. Study of influence of climber motion on the space elevator dynamics

    Directory of Open Access Journals (Sweden)

    A. S. Ledkov

    2014-01-01

    Full Text Available The operation of launching a payload into orbit by means of a space elevator is considered in this paper. The space elevator is a mechanical system that consists of a tether, a space station, and a climber. The tether connects the surface of the Earth with the space station, which is above the geostationary orbit. The climber lifts the payload to the required altitude. Then it is disconnected from the space elevator and starts free orbital flight. Creation of the space elevator will significantly reduce the cost of payloads delivery to orbit.The objective of this work is to study dynamics of the space elevator taking into account the climber motion. A mathematical model, which takes into consideration bending of the tether and features of the climber construction, is developed. In contrast to existing models, the climber is considered not as a mass point, but as a mechanical system consisting of two homogeneous weighty cylinders connected by a weightless strap upon which the payload is located. The payload and the space stations are considered as mass points. The tether is simulated as a pair of inelastic inextensible bars with variable length. The area of bars cross-sections is defined by a function, which depends on the distance to the end of the bars. Motion occurs in the equatorial plane in the gravitational field of the Earth.It is shown that lifting of the climber leads to swinging of the space elevator in the equatorial plane. This effect is caused by the influence of Coriolis forces of inertia. After stopping of the climber the space elevator oscillates about the vertical. An effect of the payload mass on amplitude of the space elevator oscillation is studied. It is shown that the increasing payload mass leads to the growing amplitude of the space elevator oscillations. A control torque providing steady lifting of the payload is obtained. The results of the calculations show that the practical implementation of the space elevator

  18. From stochastic phase-space evolution to brownian motion in collective space

    Energy Technology Data Exchange (ETDEWEB)

    Benhassine, B. (Lab. de Physique Nucleaire/ CNRS et Univ. de Nantes, 44 Nantes (France)); Farine, M. (Lab. de Physique Nucleaire/ CNRS et Univ. de Nantes, 44 Nantes (France) Ecole Navale, Lamveoc-Loulmic, 29 Brest-Naval (France)); Hernandez, E.S. (Dept. de Fisica - Facultad de Ciencias Exactas y Naturales, Univ. de Buenos Aires (Argentina)); Idier, D. (Lab. de Physique Nucleaire/ CNRS et Univ. de Nantes, 44 Nantes (France)); Remaud, B. (Lab. de Physique Nucleaire/ CNRS et Univ. de Nantes, 44 Nantes (France)); Sebille, F. (Lab. de Physique Nucleaire/ CNRS et Univ. de Nantes, 44 Nantes (France))

    1994-01-24

    Within the framework of stochastic transport equations in phase space, we study the dynamics of fluctuations on collective variables in homogeneous fermion systems. The transport coefficients are formally deduced in the relaxation-time approximation and a general method to compute dynamically the dispersions of collective observables is proposed as a set of coupled equations: respectively, the BUU/Landau-Vlasov equation for the average phase-space trajectories and the equations for the averages and dispersions of the observables. Independently, we derive the general covariance matrix of phase-space fluctuations and then by projection, the dispersion on collective variables at equilibrium. Detailed numerical applications of the formalism are given; they show that the dynamics of fluctuations can be extracted from noisy numerical simulations and that the leading parameter for collective fluctuations is the excitation energy, whatever is its degree of thermalization. (orig.)

  19. From stochastic phase-space evolution to brownian motion in collective space

    International Nuclear Information System (INIS)

    Benhassine, B.; Farine, M.; Hernandez, E.S.; Idier, D.; Remaud, B.; Sebille, F.

    1994-01-01

    Within the framework of stochastic transport equations in phase space, we study the dynamics of fluctuations on collective variables in homogeneous fermion systems. The transport coefficients are formally deduced in the relaxation-time approximation and a general method to compute dynamically the dispersions of collective observables is proposed as a set of coupled equations: respectively, the BUU/Landau-Vlasov equation for the average phase-space trajectories and the equations for the averages and dispersions of the observables. Independently, we derive the general covariance matrix of phase-space fluctuations and then by projection, the dispersion on collective variables at equilibrium. Detailed numerical applications of the formalism are given; they show that the dynamics of fluctuations can be extracted from noisy numerical simulations and that the leading parameter for collective fluctuations is the excitation energy, whatever is its degree of thermalization. (orig.)

  20. From stochastic phase space evolution to Brownian motion in collective space

    International Nuclear Information System (INIS)

    Benhassine, B.; Farine, M.; Hernandez, E.S.; Idier, D.; Remaud, B.; Sebille, F.

    1993-01-01

    Within the framework of stochastic transport equations in phase space, the dynamics of fluctuations on collective variables in homogeneous fermion systems is studied. The transport coefficients are formally deduced in the relaxation time approximation and a general method to compute dynamically the dispersions of collective observables is proposed as a set of coupled equations. Independently, the general covariance matrix of phase space fluctuations and the dispersion on collective variables at equilibrium are derived. Detailed numerical applications show that dynamics of fluctuations can be extracted from noisy numerical simulations and that the leading parameter for collective fluctuations is the excitation energy whatever is its degree of thermalization. (authors). 16 refs., 12 figs

  1. Visual motion transforms visual space representations similarly throughout the human visual hierarchy.

    Science.gov (United States)

    Harvey, Ben M; Dumoulin, Serge O

    2016-02-15

    Several studies demonstrate that visual stimulus motion affects neural receptive fields and fMRI response amplitudes. Here we unite results of these two approaches and extend them by examining the effects of visual motion on neural position preferences throughout the hierarchy of human visual field maps. We measured population receptive field (pRF) properties using high-field fMRI (7T), characterizing position preferences simultaneously over large regions of the visual cortex. We measured pRFs properties using sine wave gratings in stationary apertures, moving at various speeds in either the direction of pRF measurement or the orthogonal direction. We find direction- and speed-dependent changes in pRF preferred position and size in all visual field maps examined, including V1, V3A, and the MT+ map TO1. These effects on pRF properties increase up the hierarchy of visual field maps. However, both within and between visual field maps the extent of pRF changes was approximately proportional to pRF size. This suggests that visual motion transforms the representation of visual space similarly throughout the visual hierarchy. Visual motion can also produce an illusory displacement of perceived stimulus position. We demonstrate perceptual displacements using the same stimulus configuration. In contrast to effects on pRF properties, perceptual displacements show only weak effects of motion speed, with far larger speed-independent effects. We describe a model where low-level mechanisms could underlie the observed effects on neural position preferences. We conclude that visual motion induces similar transformations of visuo-spatial representations throughout the visual hierarchy, which may arise through low-level mechanisms. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Ambiguous Tilt and Translation Motion Cues in Astronauts after Space Flight

    Science.gov (United States)

    Clement, G.; Harm, D. L.; Rupert, A. H.; Beaton, K. H.; Wood, S. J.

    2008-01-01

    Adaptive changes during space flight in how the brain integrates vestibular cues with visual, proprioceptive, and somatosensory information can lead to impaired movement coordination, vertigo, spatial disorientation, and perceptual illusions following transitions between gravity levels. This joint ESA-NASA pre- and post-flight experiment is designed to examine both the physiological basis and operational implications for disorientation and tilt-translation disturbances in astronauts following short-duration space flights. The first specific aim is to examine the effects of stimulus frequency on adaptive changes in eye movements and motion perception during independent tilt and translation motion profiles. Roll motion is provided by a variable radius centrifuge. Pitch motion is provided by NASA's Tilt-Translation Sled in which the resultant gravitoinertial vector remains aligned with the body longitudinal axis during tilt motion (referred to as the Z-axis gravitoinertial or ZAG paradigm). We hypothesize that the adaptation of otolith-mediated responses to these stimuli will have specific frequency characteristics, being greatest in the mid-frequency range where there is a crossover of tilt and translation. The second specific aim is to employ a closed-loop nulling task in which subjects are tasked to use a joystick to null-out tilt motion disturbances on these two devices. The stimuli consist of random steps or sum-of-sinusoids stimuli, including the ZAG profiles on the Tilt-Translation Sled. We hypothesize that the ability to control tilt orientation will be compromised following space flight, with increased control errors corresponding to changes in self-motion perception. The third specific aim is to evaluate how sensory substitution aids can be used to improve manual control performance. During the closed-loop nulling task on both devices, small tactors placed around the torso vibrate according to the actual body tilt angle relative to gravity. We hypothesize

  3. Space Physiology and Operational Space Medicine

    Science.gov (United States)

    Scheuring, Richard A.

    2009-01-01

    The objectives of this slide presentation are to teach a level of familiarity with: the effects of short and long duration space flight on the human body, the major medical concerns regarding future long duration missions, the environmental issues that have potential medical impact on the crew, the role and capabilities of the Space Medicine Flight Surgeon and the environmental impacts experienced by the Apollo crews. The main physiological effects of space flight on the human body reviewed in this presentation are: space motion sickness (SMS), neurovestibular, cardiovascular, musculoskeletal, immune/hematopoietic system and behavioral/psycho-social. Some countermeasures are discussed to these effects.

  4. Rocking or rolling--perception of ambiguous motion after returning from space.

    Directory of Open Access Journals (Sweden)

    Gilles Clément

    Full Text Available The central nervous system must resolve the ambiguity of inertial motion sensory cues in order to derive an accurate representation of spatial orientation. Adaptive changes during spaceflight in how the brain integrates vestibular cues with other sensory information can lead to impaired movement coordination, vertigo, spatial disorientation, and perceptual illusions after return to Earth. The purpose of this study was to compare tilt and translation motion perception in astronauts before and after returning from spaceflight. We hypothesized that these stimuli would be the most ambiguous in the low-frequency range (i.e., at about 0.3 Hz where the linear acceleration can be interpreted either as a translation or as a tilt relative to gravity. Verbal reports were obtained in eleven astronauts tested using a motion-based tilt-translation device and a variable radius centrifuge before and after flying for two weeks on board the Space Shuttle. Consistent with previous studies, roll tilt perception was overestimated shortly after spaceflight and then recovered with 1-2 days. During dynamic linear acceleration (0.15-0.6 Hz, ±1.7 m/s2 perception of translation was also overestimated immediately after flight. Recovery to baseline was observed after 2 days for lateral translation and 8 days for fore-aft translation. These results suggest that there was a shift in the frequency dynamic of tilt-translation motion perception after adaptation to weightlessness. These results have implications for manual control during landing of a space vehicle after exposure to microgravity, as it will be the case for human asteroid and Mars missions.

  5. Motion state analysis of space target based on optical cross section

    Science.gov (United States)

    Tian, Qichen; Li, Zhi; Xu, Can; Liu, Chenghao

    2017-10-01

    In order to solve the problem that the movement state analysis method of the space target based on OCS is not related to the real motion state. This paper proposes a method based on OCS for analyzing the state of space target motion. This paper first establish a three-dimensional model of real STSS satellite, then change the satellite's surface into element, and assign material to each panel according to the actual conditions of the satellite. This paper set up a motion scene according to the orbit parameters of STSS satellite in STK, and the motion states are set to three axis steady state and slowly rotating unstable state respectively. In these two states, the occlusion condition of the surface element is firstly determined, and the effective face element is selected. Then, the coordinates of the observation station and the solar coordinates in the satellite body coordinate system are input into the OCS calculation program, and the OCS variation curves of the three axis steady state and the slow rotating unstable state STSS satellite are obtained. Combining the satellite surface structure and the load situation, the OCS change curve of the three axis stabilized satellite is analyzed, and the conclude that the OCS curve fluctuates up and down when the sunlight is irradiated to the load area; By using Spectral analysis method, autocorrelation analysis and the cross residual method, the rotation speed of OCS satellite in slow rotating unstable state is analyzed, and the rotation speed of satellite is successfully reversed. By comparing the three methods, it is found that the cross residual method is more accurate.

  6. The motion of a classical spinning point particle in a Riemann-Cartan space-time

    International Nuclear Information System (INIS)

    Amorim, R.

    1983-01-01

    A consistent set of equations of motion for classical charged point particles with spin and magnetic dipole moment in a Riemann-Cartan space-time is generated from a generalized Lagrangean formalism. The equations avoid the spurius free helicoidal solutions and at the same time conserve the canonical condition of normalization of the 4-velocity. The 4-velocity and the mechanical moment are paralell in this theory, where the condition of orthogonality between the spin and the 4-velocity is treated as a non-holonomic one. (Author) [pt

  7. Restoration of color images degraded by space-variant motion blur

    Czech Academy of Sciences Publication Activity Database

    Šorel, Michal; Flusser, Jan

    2007-01-01

    Roč. 2007, č. 4673 (2007), s. 450-457 ISSN 0302-9743. [Computer Analysis of Images and Patterns. Vienna, 27.08.2007-29.08.2007] R&D Projects: GA MŠk 1M0572 Institutional research plan: CEZ:AV0Z10750506 Keywords : deblurring * space-variant restoration * motion blur * color Subject RIV: JD - Computer Applications, Robotics Impact factor: 0.402, year: 2005 http://dx.doi.org/10.1007/978-3-540-74272-2_56

  8. Space Weather Influence on Relative Motion Control using the Touchless Electrostatic Tractor

    Science.gov (United States)

    Hogan, Erik A.; Schaub, Hanspeter

    2016-09-01

    With recent interest in the use of electrostatic forces for contactless tugging and attitude control of noncooperative objects for orbital servicing and active debris mitigation, the need for a method of remote charge control arises. In this paper, the use of a directed electron beam for remote charge control is considered in conjunction with the relative motion control. A tug vehicle emits an electron beam onto a deputy object, charging it negatively. At the same time, the tug is charged positively due to beam emission, resulting in an attractive electrostatic force. The relative position feedback control between the tug and the passive debris object is studied subject to the charging being created through an electron beam. Employing the nominal variations of the GEO space weather conditions across longitude slots, two electrostatic tugging strategies are considered. First, the electron beam current is adjusted throughout the orbit in order to maximize this resulting electrostatic force. This open-loop control strategy compensates for changes in the nominally expected local space weather environment in the GEO region to adjust for fluctuations in the local plasma return currents. Second, the performance impact of using a fixed electron beam current on the electrostatic tractor is studied if the same natural space weather variations are assumed. The fixed electron beam current shows a minor performance penalty (<5 %) while providing a much simpler implementation that does not require any knowledge of local space weather conditions.

  9. Longitudinal motion in high current ion beams: a self-consistent phase space distribution with an envelope equation

    International Nuclear Information System (INIS)

    Neuffer, D.

    1979-03-01

    Many applications of particle acceleration, such as heavy ion fusion, require longitudinal bunching of a high intensity particle beam to extremely high particle currents with correspondingly high space charge forces. This requires a precise analysis of longitudinal motion including stability analysis. Previous papers have treated the longitudinal space charge force as strictly linear, and have not been self-consistent; that is, they have not displayed a phase space distribution consistent with this linear force so that the transport of the phase space distribution could be followed, and departures from linearity could be analyzed. This is unlike the situation for transverse phase space where the Kapchinskij--Vladimirskij (K--V) distribution can be used as the basis of an analysis of transverse motion. In this paper a self-consistent particle distribution in longitudinal phase space is derived which is a solution of the Vlasov equation and an envelope equation for this solution is derived

  10. Compilation of Published Estimates of Annual Geocenter Motions Using Space Geodesy

    Science.gov (United States)

    Elosegui, P.

    2005-01-01

    The definition of the term "geocenter motion" depends on the adopted origin of the reference frame. Common reference frames used in Space Geodesy include: the center of mass of the whole Earth (CM), the center of mass of the Solid Earth without mass load (CE), and the center of figure of the outer surface of the Solid Earth (CF). There are two established definitions of the term geocenter: one, the vector offset of CF relative to CM and, two, the reverse, the vector offset of CM relative to CF. Obviously, their amplitude is the same and their phase differs by 180 deg. Following Dong et al. [2003], we label the first X(sub CF, sup CM) and the second X(sup CF, sup CM) (i.e., the superscript represents the frame, the subscript represents any point in the frame).

  11. The linear parameters and the decoupling matrix for linearly coupled motion in 6 dimensional phase space

    International Nuclear Information System (INIS)

    Parzen, G.

    1997-01-01

    It will be shown that starting from a coordinate system where the 6 phase space coordinates are linearly coupled, one can go to a new coordinate system, where the motion is uncoupled, by means of a linear transformation. The original coupled coordinates and the new uncoupled coordinates are related by a 6 x 6 matrix, R. It will be shown that of the 36 elements of the 6 x 6 decoupling matrix R, only 12 elements are independent. A set of equations is given from which the 12 elements of R can be computed form the one period transfer matrix. This set of equations also allows the linear parameters, the β i , α i , i = 1, 3, for the uncoupled coordinates, to be computed from the one period transfer matrix

  12. Worried sick? Sickness absence during organizational turmoil

    OpenAIRE

    Bratberg, Espen; Monstad, Karin

    2011-01-01

    Sickness absence has risen over the past years in Norway. An explanation put forward is that a tougher labour market represents a health hazard, while a competing hypothesis predicts that loss of job security works as a disciplinary device. In this analysis we aim to trace a causal impact of organizational turmoil or job insecurity on sickness absence, applying a difference-in-difference approach. Utilizing a negative financial shock that hit specific employers and workplaces, we find that...

  13. Vestibular factors influencing the biomedical support of humans in space.

    Science.gov (United States)

    Lichtenberg, B K

    1988-01-01

    This paper will describe the biomedical support aspects of humans in space with respect to the vestibular system. The vestibular system is thought to be the primary sensory system involved in the short-term effects of space motion sickness although there is increasing evidence that many factors play a role in this complex set of symptoms. There is the possibility that an individual's inner sense of orientation may be strongly coupled with the susceptibility to space motion sickness. A variety of suggested countermeasures for space motion sickness will be described. Although there are no known ground-based tests that can predict space motion sickness, the search should go on. The long term effects of the vestibular system in weightlessness are still relatively unknown. Some preliminary data has shown that the otoconia are irregular in size and distribution following extended periods of weightlessness. The ramifications of this data are not yet known and because the data was obtained on lower order animals, definitive studies and results must wait until the space station era when higher primates can be studied for long durations. This leads us to artificial gravity, the last topic of this paper. The vestibular system is intimately tied to this question since it has been shown on Earth that exposure to a slow rotating room causes motion sickness for some period of time before adaptation occurs. If the artificial gravity is intermittent, will this mean that people will get sick every time they experience it? The data from many astronauts returning to Earth indicates that a variety of sensory illusions are present, especially immediately upon return to a 1-g environment. Oscillopsia or apparent motion of the visual surround upon head motion along with inappropriate eye motions for a given head motion, all indicate that there is much to be studied yet about the vestibular and CNS systems reaction to a sudden application of a steady state acceleration field like 1-g. From

  14. Task-space separation principle: a force-field approach to motion planning for redundant manipulators.

    Science.gov (United States)

    Tommasino, Paolo; Campolo, Domenico

    2017-02-03

    In this work, we address human-like motor planning in redundant manipulators. Specifically, we want to capture postural synergies such as Donders' law, experimentally observed in humans during kinematically redundant tasks, and infer a minimal set of parameters to implement similar postural synergies in a kinematic model. For the model itself, although the focus of this paper is to solve redundancy by implementing postural strategies derived from experimental data, we also want to ensure that such postural control strategies do not interfere with other possible forms of motion control (in the task-space), i.e. solving the posture/movement problem. The redundancy problem is framed as a constrained optimization problem, traditionally solved via the method of Lagrange multipliers. The posture/movement problem can be tackled via the separation principle which, derived from experimental evidence, posits that the brain processes static torques (i.e. posture-dependent, such as gravitational torques) separately from dynamic torques (i.e. velocity-dependent). The separation principle has traditionally been applied at a joint torque level. Our main contribution is to apply the separation principle to Lagrange multipliers, which act as task-space force fields, leading to a task-space separation principle. In this way, we can separate postural control (implementing Donders' law) from various types of tasks-space movement planners. As an example, the proposed framework is applied to the (redundant) task of pointing with the human wrist. Nonlinear inverse optimization (NIO) is used to fit the model parameters and to capture motor strategies displayed by six human subjects during pointing tasks. The novelty of our NIO approach is that (i) the fitted motor strategy, rather than raw data, is used to filter and down-sample human behaviours; (ii) our framework is used to efficiently simulate model behaviour iteratively, until it converges towards the experimental human strategies.

  15. Tourists in space a practical guide

    CERN Document Server

    Seedhouse, Erik

    2014-01-01

    Forget Hawaii or the Mediterranean. Soon – very soon – you’ll be able to add a much more exotic stamp to your passport: space. How will you get there, what will the trip be like, and how much training will you need? All you need to know is right here in this guide. Tourists in Space: A Practical Guide supplies all the advice and information you need to make your spaceflight the most rewarding experience of your life. This definitive, real-world guide is packed with helpful facts and suggestions on everything from training, equipment, safety, and in-flight procedures to techniques for avoiding space motion sickness and bone demineralization. You’ll also find: • Advice on choosing your training agency • Techniques for minimizing the risk of space motion sickness • Information you need to prepare for your medical examination, training, and flight • Tips on activities near your training location And much more.

  16. Analyses of Sickness Absence

    NARCIS (Netherlands)

    Heijnen, S.M.M.

    2014-01-01

    Sickness absence is an empirical phenomenon of all time. Generally, it has a medical cause. However, other factors also appear to have an impact on the actual rate of sickness absence, such as the institutional setting, the business cycle and the economic structure. Many questions on the different

  17. Presenteeism among sick workers

    NARCIS (Netherlands)

    Houtman, I.L.D.

    2003-01-01

    Much attention has been focused on absenteeism. However, ‘presenteeism’ is also an issue, i.e. staying at work even when feeling sick. Analyses have shown that, the greater the work pressure, the higher the percentage of people who keep working when feeling sick.

  18. Human tolerance to space flight

    Science.gov (United States)

    Huntoon, C. L.

    1989-01-01

    Medical studies of astronauts and cosmonauts before, during, and after space missions have identified several effects of weightlessness and other factors that influence the ability of humans to tolerate space flight. Weightlessness effects include space motion sickness, cardiovascular abnormalities, reduction in immune system function, loss of red blood cells, loss of bone mass, and muscle atrophy. Extravehicular activity (EVA) increases the likelihood that decompression sickness may occur. Radiation also gives reason for concern about health of crewmembers, and psychological factors are important on long-term flights. Countermeasures that have been used include sensory preadaptation, prebreathing and use of various air mixtures for EVA, loading with water and electrolytes, exercise, use of pharmacological agents and special diets, and psychological support. It appears that humans can tolerate and recover satisfactorily from at least one year of space flight, but a number of conditions must be further ameliorated before long-duration missions can be considered routine.

  19. SU-E-T-510: Interplay Between Spots Sizes, Spot / Line Spacing and Motion in Spot Scanning Proton Therapy

    International Nuclear Information System (INIS)

    Lee, TK

    2015-01-01

    Purpose In proton beam configuration for spot scanning proton therapy (SSPT), one can define the spacing between spots and lines of scanning as a ratio of given spot size. If the spacing increases, the number of spots decreases which can potentially decrease scan time, and so can whole treatment time, and vice versa. However, if the spacing is too large, the uniformity of scanned field decreases. Also, the field uniformity can be affected by motion during SSPT beam delivery. In the present study, the interplay between spot/ line spacing and motion is investigated. Methods We used four Gaussian-shape spot sizes with 0.5cm, 1.0cm, 1.5cm, and 2.0cm FWHM, three spot/line spacing that creates uniform field profile which are 1/3*FWHM, σ/3*FWHM and 2/3*FWHM, and three random motion amplitudes within, +/−0.3mm, +/−0.5mm, and +/−1.0mm. We planned with 2Gy uniform single layer of 10×10cm2 and 20×20cm2 fields. Then, mean dose within 80% area of given field size, contrubuting MU per each spot assuming 1cGy/MU calibration for all spot sizes, number of spots and uniformity were calculated. Results The plans with spot/line spacing equal to or smaller than 2/3*FWHM without motion create ∼100% uniformity. However, it was found that the uniformity decreases with increased spacing, and it is more pronounced with smaller spot sizes, but is not affected by scanned field sizes. Conclusion It was found that the motion during proton beam delivery can alter the dose uniformity and the amount of alteration changes with spot size which changes with energy and spot/line spacing. Currently, robust evaluation in TPS (e.g. Eclipse system) performs range uncertainty evaluation using isocenter shift and CT calibration error. Based on presented study, it is recommended to add interplay effect evaluation to robust evaluation process. For future study, the additional interplay between the energy layers and motion is expected to present volumetric effect

  20. Orientation in space - one of constituents of dancings motions of deaf children 6-10 years old.

    Directory of Open Access Journals (Sweden)

    Statiev S.I.

    2011-12-01

    Full Text Available The indexes of development of orientation in space of deaf children of midchildhood are considered. 258 children took part in experiment (from them 100 are children without pathology of auditory to the analyzer. The constituents of dancings motions of children are considered. The necessity of perfection of specific co-ordinating capabilities is marked for children. Possibilities are rotined in relation to the arbitrary weakening of muscles, vestibular firmness. It is well-proven that indexes of development of orientation in space of deaf children considerably less indexes of children without violation of auditory to the analyzer. It is set that the basic constituents of dancings motions are instrumental in the improvement of parameters of orientation of children in space.

  1. Pharmacotherapeutic Aspects of Space Medicine

    Science.gov (United States)

    Putcha, Lakshmi

    2004-01-01

    Medications are used for a wide variety of indications during space flight. For example, astronauts have taken drugs in flight to ameliorate or prevent symptoms of space motion sickness, headache, sleeplessness, backache, nasal congestion, and constipation. Russian cosmonauts reportedly take medications to prevent metabolic disturbances of the myocardium and intestinal flora, and to optimize their work capacity. Although the discomfort associated with some acute responses to microgravity (e.g., space motion sickness) is expected to diminish with length of time in flight, other responses that have delayed onset (e.g., maintaining nutritional status, bone and muscle strength, and perhaps immune response) may affect health and quality of life during longer missions. Therefore, as the duration of space flights increases, the need for treatment with medications is expected to increase accordingly. Medications carried on Space Shuttle missions have varied somewhat from flight to flight, depending on the individual needs of the crewmembers. Medications use during Shuttle flights seems to be more prevalent than during earlier programs, perhaps because drugs are provided in easy-to-use forms. In fact, nearly all medications taken to date have been ingested orally in tablet form. However, given that the oral route may not be ideal for those suffering motion-sickness symptoms, intramuscular and intranasal preparations are being tested. For example, intramuscular administration of promethazine hydrochloride (Phenergan(Registered TradeMark)) has been reported to be more effective in alleviating motion-sickness symptoms. The difficulties involved in conducting definitive studies of drug efficacy during U.S. space flights have been compounded by the absence of a systematic approach to determining which drugs were taken by whom and under what circumstances. The use of some drugs in space has been less efficacious than expected. The onset, intensity, and duration of the response

  2. Geometrical-integrability constraints and equations of motion in four plus extended super spaces

    International Nuclear Information System (INIS)

    Chau, L.L.

    1987-01-01

    It is pointed out that many equations of motion in physics, including gravitational and Yang-Mills equations, have a common origin: i.e. they are the results of certain geometrical integrability conditions. These integrability conditions lead to linear systems and conservation laws that are important in integrating these equations of motion

  3. Quantum harmonic Brownian motion in a general environment: A modified phase-space approach

    International Nuclear Information System (INIS)

    Yeh, L.

    1993-01-01

    After extensive investigations over three decades, the linear-coupling model and its equivalents have become the standard microscopic models for quantum harmonic Brownian motion, in which a harmonically bound Brownian particle is coupled to a quantum dissipative heat bath of general type modeled by infinitely many harmonic oscillators. The dynamics of these models have been studied by many authors using the quantum Langevin equation, the path-integral approach, quasi-probability distribution functions (e.g., the Wigner function), etc. However, the quantum Langevin equation is only applicable to some special problems, while other approaches all involve complicated calculations due to the inevitable reduction (i.e., contraction) operation for ignoring/eliminating the degrees of freedom of the heat bath. In this dissertation, the author proposes an improved methodology via a modified phase-space approach which employs the characteristic function (the symplectic Fourier transform of the Wigner function) as the representative of the density operator. This representative is claimed to be the most natural one for performing the reduction, not only because of its simplicity but also because of its manifestation of geometric meaning. Accordingly, it is particularly convenient for studying the time evolution of the Brownian particle with an arbitrary initial state. The power of this characteristic function is illuminated through a detailed study of several physically interesting problems, including the environment-induced damping of quantum interference, the exact quantum Fokker-Planck equations, and the relaxation of non-factorizable initial states. All derivations and calculations axe shown to be much simplified in comparison with other approaches. In addition to dynamical problems, a novel derivation of the fluctuation-dissipation theorem which is valid for all quantum linear systems is presented

  4. Acute mountain sickness

    Science.gov (United States)

    ... GO About MedlinePlus Site Map FAQs Customer Support Health Topics Drugs & Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Acute mountain sickness URL of this page: //medlineplus.gov/ency/article/ ...

  5. Path integral approach for quantum motion on spaces of non-constant curvature according to Koenigs - Three dimensions

    International Nuclear Information System (INIS)

    Grosche, C.

    2007-08-01

    In this contribution a path integral approach for the quantum motion on three-dimensional spaces according to Koenigs, for short''Koenigs-Spaces'', is discussed. Their construction is simple: One takes a Hamiltonian from three-dimensional flat space and divides it by a three-dimensional superintegrable potential. Such superintegrable potentials will be the isotropic singular oscillator, the Holt-potential, the Coulomb potential, or two centrifugal potentials, respectively. In all cases a non-trivial space of non-constant curvature is generated. In order to obtain a proper quantum theory a curvature term has to be incorporated into the quantum Hamiltonian. For possible bound-state solutions we find equations up to twelfth order in the energy E. (orig.)

  6. Solvable Quantum Macroscopic Motions and Decoherence Mechanisms in Quantum Mechanics on Nonstandard Space

    Science.gov (United States)

    Kobayashi, Tsunehiro

    1996-01-01

    Quantum macroscopic motions are investigated in the scheme consisting of N-number of harmonic oscillators in terms of ultra-power representations of nonstandard analysis. Decoherence is derived from the large internal degrees of freedom of macroscopic matters.

  7. Mathematical models of decision making on space vehicle motion control at fuzzy conditions

    International Nuclear Information System (INIS)

    Arslanov, M.Z.; Ismail, E.E.; Oryspaev, D.O.

    2005-01-01

    the structure of decision making for control of spacecraft motion is considered. Mathematical models of decision making problems are investigated. New methods of criteria convolution are received. New convolution have properties of smoothness. (author)

  8. Sick building syndrome

    Directory of Open Access Journals (Sweden)

    Tjandra Y. Aditama

    2002-06-01

    Full Text Available Sick building syndrome describes a number of mostly unspesific complaints of some occupants of the building. The exact pathophysiological mechanism remains elusive. It is a multi factorial event which may include physical, chemical, biological as well as psycological factors. In many cases it is due to insufficient maintenance of the HVAC (heating, ventilation, air conditioning system in the building. Sign and symptoms can be uncomfortable and even disabling, which may include mucus membrane irritation, neurotoxic symptoms, asthma like symptoms, skin complaints, gastrointestinal symptoms and other related symptoms. There are various investigation methods to diagnose sick building syndrome, and on site assessment of the building is extremely useful. Prevention through a proactive air quality monitoring program is far more desirable than dealing with an actual sick building. Indoor air and the sick building symdrome serves as a paradigm of modern occupational and environmental medicine. (Med J Indones 2002; 11:124-31Keywords: indoor air pollution, sick building syndrome, building related illness

  9. Dynamic Visual Acuity and Landing Sickness in Crewmembers Returning from Long-Duration Spaceflight

    Science.gov (United States)

    Rosenberg, M.J.F; Peters, B.T.; Reschke, M. F.

    2016-01-01

    Long-term exposure to microgravity causes sensorimotor adaptations that result in functional deficits upon returning to a gravitational environment. At landing the vestibular system and the central nervous system, responsible for coordinating head and eye movements, are adapted to microgravity and must re-adapt to the gravitational environment. This re-adaptation causes decrements in gaze control and dynamic visual acuity, with astronauts reporting oscillopsia and blurred vision. Dynamic visual acuity (DVA) is assessed using an oscillating chair developed in the Neuroscience Laboratory at JSC. This chair is lightweight and easily portable for quick deployment in the field. The base of the chair is spring-loaded and allows for manual oscillation of the subject. Using a metronome, the chair is vertically oscillated plus or minus 2 cm at 2 Hz by an operator, to simulate walking. While the subject is being oscillated, they are asked to discern the direction of Landolt-C optotypes of varying sizes and record their direction using a gamepad. The visual acuity thresholds are determined using an algorithm that alters the size of the optotype based on the previous response of the subject using a forced-choice best parameter estimation that is able to rapidly converge on the threshold value. Visual acuity thresholds were determined both for static (seated) and dynamic (oscillating) conditions. Dynamic visual acuity is defined as the difference between the dynamic and static conditions. Dynamic visual acuity measures will be taken prior to flight (typically L-180, L-90, and L-60) and up to eight times after landing, including up to 3 times on R plus 0. Follow up measurements will be taken at R plus 1 (approximately 36 hours after landing). Long-duration International Space Station crewmembers will be tested once at the refueling stop in Europe and once again upon return to Johnson Space Center. In addition to DVA, subjective ratings of motion sickness will be recorded

  10. Controlled motion in an elastic world. Research project: Manipulation strategies for massive space payloads

    Science.gov (United States)

    Book, Wayne J.

    1992-01-01

    The flexibility of the drives and structures of controlled motion systems are presented as an obstacle to be overcome in the design of high performance motion systems, particularly manipulator arms. The task and the measure of performance to be applied determine the technology appropriate to overcome this obstacle. Included in the technologies proposed are control algorithms (feedback and feed forward), passive damping enhancement, operational strategies, and structural design. Modeling of the distributed, nonlinear system is difficult, and alternative approaches are discussed. The author presents personal perspectives on the history, status, and future directions in this area.

  11. On the Calculation of Quantum Mechanical Ground States from Classical Geodesic Motion on Certain Spaces of Constant Negative Curvature

    CERN Document Server

    Tomaschitz, R

    1989-01-01

    We consider geodesic motion on three-dimensional Riemannian manifolds of constant negative curvature, topologically equivalent to S x ]0,1[, S a compact surface of genus two. To those trajectories which are bounded and recurrent in both directions of the time evolution a fractal limit set is associated whose Hausdorff dimension is intimately connected with the quantum mechanical energy ground state, determined by the Schrodinger operator on the manifold. We give a rather detailed and pictorial description of the hyperbolic spaces we have in mind, discuss various aspects of classical and quantum mechanical motion on them as far as they are needed to establish the connection between energy ground state and Hausdorff dimension and give finally some examples of ground state calculations in terms of Hausdorff dimensions of limit sets of classical trajectories.

  12. On the calculation of quantum mechanical ground states from classical geodesic motion on certain spaces of constant negative curvature

    International Nuclear Information System (INIS)

    Tomaschitz, R.

    1989-01-01

    We consider geodesic motion on three-dimensional Riemannian manifolds of constant negative curvature, topologically equivalent to S x ]0,1[, S a compact surface of genus two. To those trajectories which are recurrent in both directions of the time evolution t → +∞, t → -∞ a fractal limit set is associated whose Hausdorff dimension is intimately connected with the quantum mechanical energy ground state, determined by the Schroedinger operator on the manifold. We give a rather detailed and pictorial description of the hyperbolic spaces we have in mind, discuss various aspects of classical and quantum mechanical motion on them as far as they are needed to establish the connection between energy ground state and Hausdorff dimension and give finally some examples of ground state calculations in terms of Hausdorff dimensions of limit sets of classical trajectories. (orig.)

  13. A motion of spacelike curves in the Minkowski 3-space and the KdV equation

    International Nuclear Information System (INIS)

    Ding Qing; Wang Wei; Wang Youde

    2010-01-01

    This Letter shows that soliton solutions to KdV equation describe a motion of spacelike curves in R 2,1 with initial data being suitably restricted. This gives a different geometric interpretation of KdV from that given recently by Musso and Nicolodi, and gives a unified geometric explanation for KdV and MKdV.

  14. Modeling and dynamic simulation of astronaut's upper limb motions considering counter torques generated by the space suit.

    Science.gov (United States)

    Li, Jingwen; Ye, Qing; Ding, Li; Liao, Qianfang

    2017-07-01

    Extravehicular activity (EVA) is an inevitable task for astronauts to maintain proper functions of both the spacecraft and the space station. Both experimental research in a microgravity simulator (e.g. neutral buoyancy tank, zero-g aircraft or a drop tower/tube) and mathematical modeling were used to study EVA to provide guidance for the training on Earth and task design in space. Modeling has become more and more promising because of its efficiency. Based on the task analysis, almost 90% of EVA activity is accomplished through upper limb motions. Therefore, focusing on upper limb models of the body and space suit is valuable to this effort. In previous modeling studies, some multi-rigid-body systems were developed to simplify the human musculoskeletal system, and the space suit was mostly considered as a part of the astronaut body. With the aim to improve the reality of the models, we developed an astronauts' upper limb model, including a torque model and a muscle-force model, with the counter torques from the space suit being considered as a boundary condition. Inverse kinematics and the Maggi-Kane's method was applied to calculate the joint angles, joint torques and muscle force given that the terminal trajectory of upper limb motion was known. Also, we validated the muscle-force model using electromyogram (EMG) data collected in a validation experiment. Muscle force calculated from our model presented a similar trend with the EMG data, supporting the effectiveness and feasibility of the muscle-force model we established, and also, partially validating the joint model in kinematics aspect.

  15. The motion and control of a complex three-body space tethered system

    Science.gov (United States)

    Shi, Gefei; Zhu, Zhanxia; Chen, Shiyu; Yuan, Jianping; Tang, Biwei

    2017-11-01

    This paper is mainly devoted to investigating the dynamics and stability control of a three body-tethered satellite system which contains a main satellite and two subsatellites connected by two straight, massless and inextensible tethers. Firstly, a detailed mathematical model is established in the central gravitational field. Then, the dynamic characteristics of the established system are investigated and analyzed. Based on the dynamic analysis, a novel sliding mode prediction model (SMPM) control strategy is proposed to suppress the motion of the built tethered system. The numerical results show that the proposed underactuated control law is highly effective in suppressing the attitude/libration motion of the underactuated three-body tethered system. Furthermore, cases of different target angles are also examined and analyzed. The simulation results reveal that even if the final equilibrium states differ from different selections of the target angles, the whole system can still be maintained in acceptable areas.

  16. Some analyses on the plasma motion in the space active region of the axial symmetry

    International Nuclear Information System (INIS)

    Li Zhongyuan; Hu Wenrui.

    1986-04-01

    In general, the potential magnetic field may gradually be twisted into the force-free magnetic field with the current produced by plasma rotation. In this paper, it is pointed out that if the magnetic field has no singularity on the symmetric axis, then the potential magnetic field cannot be twisted into the force-free magnetic field. Namely, it is not a perfect approach that the energy storage is only caused by the pure azimuthal motion in the active region. Besides the pure spiral motion, the unsteady coupling process between the magnetic field and both the toroidal and the poloidal velocity components should be analyzed. Finally, in the present note, some features of the kinematical force-free magnetic field of the axial symmetry are presented by the authors. (author)

  17. Applications and Innovations for Use of High Definition and High Resolution Digital Motion Imagery in Space Operations

    Science.gov (United States)

    Grubbs, Rodney

    2016-01-01

    The first live High Definition Television (HDTV) from a spacecraft was in November, 2006, nearly ten years before the 2016 SpaceOps Conference. Much has changed since then. Now, live HDTV from the International Space Station (ISS) is routine. HDTV cameras stream live video views of the Earth from the exterior of the ISS every day on UStream, and HDTV has even flown around the Moon on a Japanese Space Agency spacecraft. A great deal has been learned about the operations applicability of HDTV and high resolution imagery since that first live broadcast. This paper will discuss the current state of real-time and file based HDTV and higher resolution video for space operations. A potential roadmap will be provided for further development and innovations of high-resolution digital motion imagery, including gaps in technology enablers, especially for deep space and unmanned missions. Specific topics to be covered in the paper will include: An update on radiation tolerance and performance of various camera types and sensors and ramifications on the future applicability of these types of cameras for space operations; Practical experience with downlinking very large imagery files with breaks in link coverage; Ramifications of larger camera resolutions like Ultra-High Definition, 6,000 [pixels] and 8,000 [pixels] in space applications; Enabling technologies such as the High Efficiency Video Codec, Bundle Streaming Delay Tolerant Networking, Optical Communications and Bayer Pattern Sensors and other similar innovations; Likely future operations scenarios for deep space missions with extreme latency and intermittent communications links.

  18. Sick building syndrome

    International Nuclear Information System (INIS)

    Baechler, M.C.; Hadley, D.L.; Marseille, T.J.; Stenner, R.D.; Peterson, M.R.; Naugle, D.F.; Berry, M.A.

    1991-01-01

    This book discusses the aspect of indoor air pollution referred to as sick building syndrome. Covered are sources and health effects of various indoor air pollutants, and methods for mitigation of the problem, plus suggested analytical methods for environmental carcinogens found in indoor air

  19. Reduction of respiratory ghosting motion artifacts in conventional two-dimensional multi-slice Cartesian turbo spin-echo: which k-space filling order is the best?

    Science.gov (United States)

    Inoue, Yuuji; Yoneyama, Masami; Nakamura, Masanobu; Takemura, Atsushi

    2018-06-01

    The two-dimensional Cartesian turbo spin-echo (TSE) sequence is widely used in routine clinical studies, but it is sensitive to respiratory motion. We investigated the k-space orders in Cartesian TSE that can effectively reduce motion artifacts. The purpose of this study was to demonstrate the relationship between k-space order and degree of motion artifacts using a moving phantom. We compared the degree of motion artifacts between linear and asymmetric k-space orders. The actual spacing of ghost artifacts in the asymmetric order was doubled compared with that in the linear order in the free-breathing situation. The asymmetric order clearly showed less sensitivity to incomplete breath-hold at the latter half of the imaging period. Because of the actual number of partitions of the k-space and the temporal filling order, the asymmetric k-space order of Cartesian TSE was superior to the linear k-space order for reduction of ghosting motion artifacts.

  20. Archives, libraries and museums: containers often sick, sometimes seriously sick

    Directory of Open Access Journals (Sweden)

    Roberto Nicolucci

    2007-07-01

    Full Text Available As far as the feeling of quietness and peace that they often convey, archives, museums and libraries also hide dangers that you may not imagine, either for visitors or especially for the members of the staff. Indeed the poor microclimatic conditions – often the consequences of materials and construction or building technologies that appear definitely obsolete – often arouse suspicion and worry among the staff. Wrong Thermo hygrometric parameters, the presence of volatile organic elements, mineral fibers, biocides, radon gas, aerial dispersive molecules, are among others some of the chemical physical polluters of major influence that may contribute to giving life to the so-called Sick Building Syndrome. But such spaces also bear biological polluters that can provoke pathologies of various types and importance, among which the feared Illness of Legionnaire. The presence of electromagnetic fields, but above all wrong lighting and wrong ergonomic working positions represent some risk factors for members of staff and visitors.

  1. Design of Fuzzy Enhanced Hierarchical Motion Stabilizing Controller of Unmanned Ground Vehicle in Three DimensionalSpace

    Directory of Open Access Journals (Sweden)

    Yue Ma

    2011-12-01

    Full Text Available In this paper, stabilizing control of tracked unmanned ground vehicle in 3-D space was presented. Firstly, models of major modules of tracked UGV were established. Next, to reveal the mechanism of disturbances applied on the UGV, two kinds of representative disturbances (slope and general disturbances in yaw motion were discussed in depth. Consequently, an attempting PID method was employed to compensate the impacts of disturbances andsimulation results proved the validity for disturbance incited by slope force, but revealed the lack for general disturbance on yaw motion. Finally, a hierarchical fuzzy controller combined with PID controller was proposed. In lower level, there were two PID controllers to compensate the disturbance of slope force, and on top level, the fuzzy logic controller was employed to correct the yaw motion error based on the differences between the model and the real UGV, which was able to guide the UGV maintain on the stable state. Simulation results demonstrated the excellent effectiveness of the newly designed controller.

  2. A study of coronary artery rotational motion with dense scale-space optical flow in intravascular ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Danilouchkine, M G; Mastik, F; Steen, A F W van der [Department of Biomedical Engineering, Erasmus Medical Center, Ee2302, PO Box 2040, 3000 CA, Rotterdam (Netherlands)], E-mail: m.danilouchkine@ErasmusMC.nl, E-mail: f.mastik@ErasmusMC.nl, E-mail: a.vandersteen@ErasmusMC.nl

    2009-03-21

    This paper describes a novel method for estimating tissue motion in two-dimensional intravascular ultrasound (IVUS) images of a coronary artery. It is based on the classical Lukas-Kanade (LK) algorithm for optical flow (OF). The OF vector field quantifies the amount of misalignment between two consecutive frames in a sequence of images. From the theoretical standpoint, two fundamental improvements are proposed in this paper. First, using a simplified representation of the vessel wall as a medium with randomly distributed scatterers, it was shown that the OF equation satisfies the integral brightness conservation law. Second, a scale-space embedding for the OF equation was derived under the assumption of spatial consistency in IVUS acquisitions. The spatial coherence is equivalent to a locally affine motion model. The latter effectively captures and appropriately describes a complex deformation pattern of the coronary vessel wall under the varying physiological conditions (i.e. pulsatile blood pressure). The accuracy of OF tracking was estimated on the tissue-mimicking phantoms subjected to the controlled amount of angular deviation. Moreover, the performance of the classical LK and proposed approach was compared using the simulated IVUS images with an atherosclerotic lesion. The experimental results showed robust and reliable performance of up to 5{sup 0} of rotation, which is within the plausible range of circumferential displacement of the coronary arteries. Subsequently, the algorithm was used to analyze vessel wall motion in 18 IVUS pullbacks from 16 patients. The in vivo experiments revealed that the motion of coronary arteries is primarily determined by the cardiac contraction.

  3. The prevalence of sick leave

    DEFF Research Database (Denmark)

    Backhausen, Mette; Damm, Peter; Bendix, Jane

    2018-01-01

    of long-term sick leave. Method Data from 508 employed pregnant women seeking antenatal care was collected by questionnaires from August 2015 to March 2016. The questionnaires, which were filled in at 20 and 32 weeks of gestation, provided information on maternal characteristics, the number of days spent...... on sick leave and the associated reasons. Descriptive statistics and logistic regression analysis were applied. Results The prevalence of sick leave was 56% of employed pregnant women in the first 32 weeks of gestation and more than one in four reported long-term sick leave (>20 days, continuous...... was a negative predictor. Conclusions The prevalence of sick leave was 56% in the first 32 weeks of gestation and more than one in four women reported long-term sick leave. The majority of reasons for sick leave were pregnancy-related and low back pain was the most frequently given reason....

  4. Time and motion, experiment M151. [human performance and space flight stress

    Science.gov (United States)

    Kubis, J. F.; Elrod, J. T.; Rusnak, R.; Mcbride, G. H.; Barnes, J. E.; Saxon, S. C.

    1973-01-01

    Astronaut work performance during the preparation and execution of experiments in simulated Skylab tests was analyzed according to time and motion in order to evaluate the efficiency and consistency of performance (adaptation function) for several different types of activity over the course of the mission; to evaluate the procedures to be used by the same experiment in Skylab; to generate characteristic adaptation functions for later comparison with Skylab data; and to examine astronaut performance for any behavioral stress due to the environment. The overall results indicate that the anticipated adaptation function was obtained both for individual and for averaged data.

  5. Self-navigated 4D cartesian imaging of periodic motion in the body trunk using partial k-space compressed sensing.

    Science.gov (United States)

    Küstner, Thomas; Würslin, Christian; Schwartz, Martin; Martirosian, Petros; Gatidis, Sergios; Brendle, Cornelia; Seith, Ferdinand; Schick, Fritz; Schwenzer, Nina F; Yang, Bin; Schmidt, Holger

    2017-08-01

    To enable fast and flexible high-resolution four-dimensional (4D) MRI of periodic thoracic/abdominal motion for motion visualization or motion-corrected imaging. We proposed a Cartesian three-dimensional k-space sampling scheme that acquires a random combination of k-space lines in the ky/kz plane. A partial Fourier-like constraint compacts the sampling space to one half of k-space. The central k-space line is periodically acquired to allow an extraction of a self-navigated respiration signal used to populate a k-space of multiple breathing positions. The randomness of the acquisition (induced by periodic breathing pattern) yields a subsampled k-space that is reconstructed using compressed sensing. Local image evaluations (coefficient of variation and slope steepness through organs) reveal information about motion resolvability. Image quality is inspected by a blinded reading. Sequence and reconstruction method are made publicly available. The method is able to capture and reconstruct 4D images with high image quality and motion resolution within a short scan time of less than 2 min. These findings are supported by restricted-isometry-property analysis, local image evaluation, and blinded reading. The proposed method provides a clinical feasible setup to capture periodic respiratory motion with a fast acquisition protocol and can be extended by further surrogate signals to capture additional periodic motions. Retrospective parametrization allows for flexible tuning toward the targeted applications. Magn Reson Med 78:632-644, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  6. Fault-tolerant feature-based estimation of space debris rotational motion during active removal missions

    Science.gov (United States)

    Biondi, Gabriele; Mauro, Stefano; Pastorelli, Stefano; Sorli, Massimo

    2018-05-01

    One of the key functionalities required by an Active Debris Removal mission is the assessment of the target kinematics and inertial properties. Passive sensors, such as stereo cameras, are often included in the onboard instrumentation of a chaser spacecraft for capturing sequential photographs and for tracking features of the target surface. A plenty of methods, based on Kalman filtering, are available for the estimation of the target's state from feature positions; however, to guarantee the filter convergence, they typically require continuity of measurements and the capability of tracking a fixed set of pre-defined features of the object. These requirements clash with the actual tracking conditions: failures in feature detection often occur and the assumption of having some a-priori knowledge about the shape of the target could be restrictive in certain cases. The aim of the presented work is to propose a fault-tolerant alternative method for estimating the angular velocity and the relative magnitudes of the principal moments of inertia of the target. Raw data regarding the positions of the tracked features are processed to evaluate corrupted values of a 3-dimentional parameter which entirely describes the finite screw motion of the debris and which primarily is invariant on the particular set of considered features of the object. Missing values of the parameter are completely restored exploiting the typical periodicity of the rotational motion of an uncontrolled satellite: compressed sensing techniques, typically adopted for recovering images or for prognostic applications, are herein used in a completely original fashion for retrieving a kinematic signal that appears sparse in the frequency domain. Due to its invariance about the features, no assumptions are needed about the target's shape and continuity of the tracking. The obtained signal is useful for the indirect evaluation of an attitude signal that feeds an unscented Kalman filter for the estimation of

  7. Social inequalities in "sickness"

    DEFF Research Database (Denmark)

    van der Wel, Kjetil A; Dahl, Espen; Thielen, Karsten

    2012-01-01

    In comparative studies of health inequalities, public health researchers have usually studied only disease and illness. Recent studies have also examined the sickness dimension of health, that is, the extent to which ill health is accompanied by joblessness, and how this association varies...... consistent results. They analyze data from the European Union Statistics on Income and Living Conditions (EU-SILC); health was measured by limiting longstanding illness (LLSI). Results show that for both men and women reporting LLSI in combination with low educational level, the probabilities of non......-employment were particularly high in the Anglo-Saxon and Eastern welfare regimes, and lowest in the Scandinavian regime. For men, absolute and relative social inequalities in sickness were lowest in the Southern regime; for women, inequalities were lowest in the Scandinavian regime. The authors conclude...

  8. Real-time prediction of respiratory motion based on a local dynamic model in an augmented space.

    Science.gov (United States)

    Hong, S-M; Jung, B-H; Ruan, D

    2011-03-21

    Motion-adaptive radiotherapy aims to deliver ablative radiation dose to the tumor target with minimal normal tissue exposure, by accounting for real-time target movement. In practice, prediction is usually necessary to compensate for system latency induced by measurement, communication and control. This work focuses on predicting respiratory motion, which is most dominant for thoracic and abdominal tumors. We develop and investigate the use of a local dynamic model in an augmented space, motivated by the observation that respiratory movement exhibits a locally circular pattern in a plane augmented with a delayed axis. By including the angular velocity as part of the system state, the proposed dynamic model effectively captures the natural evolution of respiratory motion. The first-order extended Kalman filter is used to propagate and update the state estimate. The target location is predicted by evaluating the local dynamic model equations at the required prediction length. This method is complementary to existing work in that (1) the local circular motion model characterizes 'turning', overcoming the limitation of linear motion models; (2) it uses a natural state representation including the local angular velocity and updates the state estimate systematically, offering explicit physical interpretations; (3) it relies on a parametric model and is much less data-satiate than the typical adaptive semiparametric or nonparametric method. We tested the performance of the proposed method with ten RPM traces, using the normalized root mean squared difference between the predicted value and the retrospective observation as the error metric. Its performance was compared with predictors based on the linear model, the interacting multiple linear models and the kernel density estimator for various combinations of prediction lengths and observation rates. The local dynamic model based approach provides the best performance for short to medium prediction lengths under relatively

  9. ACUTE MOUNTAIN SICKNESS

    Directory of Open Access Journals (Sweden)

    Jakub Krzeszowiak

    2012-03-01

    Full Text Available This paper presents the most likely pathophysiological causes of the development of acute mountain sickness (AMS, also known as altitude sickness, its pulmonary form i.e. high altitude pulmonary edema (HAPE, and high altitude cerebral edema (HACE. These diseases constitute extraordinary environmental hazards because they are directly connected with low atmospheric pressure, and thus low partial oxygen pressure. The above adverse atmospheric conditions start to affect humans already at an altitude of 2,500 meters above the sea level and, coupled with extreme physical exertion, can quickly lead to respiratory alkalosis, which is not present under any other conditions in the lowlands. Mountaineering above 4,500 m a.s.l. leads to hypoxia of internal organs and, primarily, reduced renal perfusion with all its consequences. The above adverse changes, combined with inadequate acclimatization, can lead to a situation of imminent danger to life and health. This paper describes in detail the consequences of acute mountain sickness, which can ultimately lead to the development of AMS and one of severe forms of HACE and/or HAPE.

  10. Memories in Motion: Learning, Process, History and Art in Public Space

    Science.gov (United States)

    Qadri, Debbie

    2015-01-01

    This essay presents an art project as an example of two aspects of public pedagogy. The first, is that the project critically examined how history is made, and through art-making and installation it performed an alternative publishing of history. Secondly, the art project was utilised as both a process and outcome within public space, and through…

  11. Effect of pitch–space correspondence on sound-induced visual motion perception

    NARCIS (Netherlands)

    Hidaka, Souta; Teramoto, Wataru; Keetels, Mirjam; Vroomen, J.H.M.

    2013-01-01

    The brain tends to associate specific features of stimuli across sensory modalities. The pitch of a sound is for example associated with spatial elevation such that higher-pitched sounds are felt as being “up” in space and lower-pitched sounds as being “down.” Here we investigated whether changes in

  12. 20 CFR 218.28 - Sick pay.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Sick pay. 218.28 Section 218.28 Employees... Beginning Date § 218.28 Sick pay. (a) From railroad employer. If the employee is carried on the payroll while sick, the annuity can begin no earlier than the day after the last day of sick pay. However, sick...

  13. Modification of Otolith-Ocular Reflexes, Motion Perception and Manual Control During Variable Radius Centrifugation Following Space Flight

    Science.gov (United States)

    Wood, Scott J.; Clarke, A. H.; Rupert, A. H.; Harm, D. L.; Clement, G. R.

    2009-01-01

    Two joint ESA-NASA studies are examining changes in otolith-ocular reflexes and motion perception following short duration space flights, and the operational implications of post-flight tilt-translation ambiguity for manual control performance. Vibrotactile feedback of tilt orientation is also being evaluated as a countermeasure to improve performance during a closed-loop nulling task. Data is currently being collected on astronaut subjects during 3 preflight sessions and during the first 8 days after Shuttle landings. Variable radius centrifugation is utilized to elicit otolith reflexes in the lateral plane without concordant roll canal cues. Unilateral centrifugation (400 deg/s, 3.5 cm radius) stimulates one otolith positioned off-axis while the opposite side is centered over the axis of rotation. During this paradigm, roll-tilt perception is measured using a subjective visual vertical task and ocular counter-rolling is obtained using binocular video-oculography. During a second paradigm (216 deg/s, less than 20 cm radius), the effects of stimulus frequency (0.15 - 0.6 Hz) are examined on eye movements and motion perception. A closed-loop nulling task is also performed with and without vibrotactile display feedback of chair radial position. Data collection is currently ongoing. Results to date suggest there is a trend for perceived tilt and translation amplitudes to be increased at the low and medium frequencies on landing day compared to pre-flight. Manual control performance is improved with vibrotactile feedback. One result of this study will be to characterize the variability (gain, asymmetry) in both otolith-ocular responses and motion perception during variable radius centrifugation, and measure the time course of post-flight recovery. This study will also address how adaptive changes in otolith-mediated reflexes correspond to one's ability to perform closed-loop nulling tasks following G-transitions, and whether manual control performance can be improved

  14. Large motion high cycle high speed optical fibers for space based applications.

    Energy Technology Data Exchange (ETDEWEB)

    Stromberg, Peter G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Tandon, Rajan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gibson, Cory S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Reedlunn, Benjamin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rasberry, Roger David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rohr, Garth David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-10-01

    Future remote sensing applications will require higher resolution and therefore higher data rates (up to perhaps 100 gigabits per second) while achieving lower mass and cost. A current limitation to the design space is high speed high bandwidth data does not cross movable gimbals because of cabling issues. This requires the detectors to be off gimbal. The ability to get data across the gimbal would open up efficiencies in designs where the detectors and the electronics can be placed anywhere on the system. Fiber optic cables provide light weight high speed high bandwidth connections. Current options are limited to 20,000 cycles as opposed to the 1,000,000 cycles needed for future space based applications. To extend this to the million+ regime, requires a thorough understanding of the failure mechanisms and the materials, proper selection of materials (e.g., glass and jacket material) allowable geometry changes to the cable, radiation hardness, etc.

  15. Separation of atmospheric, oceanic and hydrological polar motion excitation mechanisms based on a combination of geometric and gravimetric space observations

    Science.gov (United States)

    Göttl, F.; Schmidt, M.; Seitz, F.; Bloßfeld, M.

    2015-04-01

    The goal of our study is to determine accurate time series of geophysical Earth rotation excitations to learn more about global dynamic processes in the Earth system. For this purpose, we developed an adjustment model which allows to combine precise observations from space geodetic observation systems, such as Satellite Laser Ranging (SLR), Global Navigation Satellite Systems, Very Long Baseline Interferometry, Doppler Orbit determination and Radiopositioning Integrated on Satellite, satellite altimetry and satellite gravimetry in order to separate geophysical excitation mechanisms of Earth rotation. Three polar motion time series are applied to derive the polar motion excitation functions (integral effect). Furthermore we use five time variable gravity field solutions from Gravity Recovery and Climate Experiment to determine not only the integral mass effect but also the oceanic and hydrological mass effects by applying suitable filter techniques and a land-ocean mask. For comparison the integral mass effect is also derived from degree 2 potential coefficients that are estimated from SLR observations. The oceanic mass effect is also determined from sea level anomalies observed by satellite altimetry by reducing the steric sea level anomalies derived from temperature and salinity fields of the oceans. Due to the combination of all geodetic estimated excitations the weaknesses of the individual processing strategies can be reduced and the technique-specific strengths can be accounted for. The formal errors of the adjusted geodetic solutions are smaller than the RMS differences of the geophysical model solutions. The improved excitation time series can be used to improve the geophysical modeling.

  16. Computer coordination of limb motion for locomotion of a multiple-armed robot for space assembly

    Science.gov (United States)

    Klein, C. A.; Patterson, M. R.

    1982-01-01

    Consideration is given to a possible robotic system for the construction of large space structures, which may be described as a multiple general purpose arm manipulator vehicle that can walk over the structure under construction to a given site for further work. A description is presented of the locomotion of such a vehicle, modeling its arms in terms of a currently available industrial manipulator. It is noted that for whatever maximum speed of operation is chosen, rapid changes in robot velocity create situations in which already-selected handholds are no longer practical. A step is added to the 'free gait' walking algorithm in order to solve this problem.

  17. Morning Sickness: Nausea and Vomiting of Pregnancy

    Science.gov (United States)

    ... About ACOG Morning Sickness: Nausea and Vomiting of Pregnancy Home For Patients Search FAQs Morning Sickness: Nausea ... PDF Format Morning Sickness: Nausea and Vomiting of Pregnancy Pregnancy How common is nausea and vomiting of ...

  18. SU-F-J-158: Respiratory Motion Resolved, Self-Gated 4D-MRI Using Rotating Cartesian K-Space Sampling

    Energy Technology Data Exchange (ETDEWEB)

    Han, F; Zhou, Z; Yang, Y; Sheng, K; Hu, P [UCLA School of Medicine, Los Angeles, CA (United States)

    2016-06-15

    Purpose: Dynamic MRI has been used to quantify respiratory motion of abdominal organs in radiation treatment planning. Many existing 4D-MRI methods based on 2D acquisitions suffer from limited slice resolution and additional stitching artifacts when evaluated in 3D{sup 1}. To address these issues, we developed a 4D-MRI (3D dynamic) technique with true 3D k-space encoding and respiratory motion self-gating. Methods: The 3D k-space was acquired using a Rotating Cartesian K-space (ROCK) pattern, where the Cartesian grid was reordered in a quasi-spiral fashion with each spiral arm rotated using golden angle{sup 2}. Each quasi-spiral arm started with the k-space center-line, which were used as self-gating{sup 3} signal for respiratory motion estimation. The acquired k-space data was then binned into 8 respiratory phases and the golden angle ensures a near-uniform k-space sampling in each phase. Finally, dynamic 3D images were reconstructed using the ESPIRiT technique{sup 4}. 4D-MRI was performed on 6 healthy volunteers, using the following parameters (bSSFP, Fat-Sat, TE/TR=2ms/4ms, matrix size=500×350×120, resolution=1×1×1.2mm, TA=5min, 8 respiratory phases). Supplemental 2D real-time images were acquired in 9 different planes. Dynamic locations of the diaphragm dome and left kidney were measured from both 4D and 2D images. The same protocol was also performed on a MRI-compatible motion phantom where the motion was programmed with different amplitude (10–30mm) and frequency (3–10/min). Results: High resolution 4D-MRI were obtained successfully in 5 minutes. Quantitative motion measurements from 4D-MRI agree with the ones from 2D CINE (<5% error). The 4D images are free of the stitching artifacts and their near-isotropic resolution facilitates 3D visualization and segmentation of abdominal organs such as the liver, kidney and pancreas. Conclusion: Our preliminary studies demonstrated a novel ROCK 4D-MRI technique with true 3D k-space encoding and respiratory

  19. Standing body sway in women with and without morning sickness in pregnancy.

    Science.gov (United States)

    Yu, Yawen; Chung, Hyun Chae; Hemingway, Lauren; Stoffregen, Thomas A

    2013-01-01

    Morning sickness typically is attributed to hormonal changes in pregnancy. We asked whether morning sickness is associated with changes in standing postural equilibrium, as occurs in research on visually induced motion sickness. Twenty-one pregnant women (mean age=30 years, mean height=163cm; mean weight=63kg) were tested during the first trimester. Laboratory-based balance measures were collected, along with perceived postural stability, the presence of morning sickness, and the severity of subjective symptoms. We varied the distance between the feet and the visual task performed during stance. Participants were classified as either experiencing (Sick, n=12) or not experiencing (Well, n=9) morning sickness. Perceived balance stability was lower for Sick than for Well women. The positional variability of sway was reduced for the Sick group, relative to the Well group. Positional variability decreased with wider stance width, and was reduced during performance of a more demanding visual task. Stance width and visual task also influenced the temporal dynamics of sway. Effects of stance width and visual task on postural sway were similar to effects in non-pregnant adults, suggesting that sensitive tuning of posture is maintained during the first trimester. The findings suggest that women with morning sickness may attempt to stabilize their bodies by reducing overall body sway. It may be useful to recommend that women adopt wider stance early in pregnancy. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Sickness and love: an introduction

    NARCIS (Netherlands)

    van der Geest, S.; Vandamme, S.

    2008-01-01

    Love is a neglected topic in anthropology, for good reasons: it has always resisted scientific definition and analysis. By associating love with sickness seven authors attempt to capture various meanings and experiences of love. Two broad concepts arise: love as sickness and love in response to

  1. Space-dependent effects of motion on the standard deviation of fMRI signals : a simulation study.

    NARCIS (Netherlands)

    Renken, R; Muresan, L; Duifhuis, H; Roerdink, JBTM; Yaffe, MK; Antonuk, LE

    2003-01-01

    In fMRI, any fluctuation of signal intensity, not recognized as a result of a specific task, is treated as noise. One source for "noise" is subject motion. Normally, motion effects are reduced by applying realignment. We investigate how apt a realignment procedure is in removing motion-related

  2. Sick boat syndrome

    Directory of Open Access Journals (Sweden)

    Dąbrowiecki Zbigniew

    2015-12-01

    Full Text Available Many pathogenic micro-organisms are likely to attack passengers of cruise ships and other vessels or travel between continents as a peculiar type of a “stowaway”. The epidemiological tests conducted since 1987 with regard to watercraft led to the coining of a term known as the Sick Boat Syndrome (SBS. The main illnesses encountered on watercraft include gastrointestinal diseases (foodborne and Legionellosis. Additionally, the ventilation and airconditioning systems of old commercial ships (the so-called Tramps constitute a real technical challenge. Conditioned air (with removed undesired odour and micro-organisms should constitute ca. 25% of circulating air. In practice this situation is not typical for vessels of this class. Unclean air poses a real hazard for the crew.

  3. Social inequalities in 'sickness'

    DEFF Research Database (Denmark)

    Wel, Kjetil A. van der; Dahl, Espen; Thielen, Karsten

    2011-01-01

    The aim of this paper is to examine educational inequalities in the risk of non-employment among people with illnesses and how they vary between European countries with different welfare state characteristics. In doing so, the paper adds to the growing literature on welfare states and social...... from Eurostat and OECD that include spending on active labour market policies, benefit generosity, income inequality, and employment protection. Using multilevel techniques we find that comprehensive welfare states have lower absolute and relative social inequalities in sickness, as well as more...... inequalities in health by studying the often overlooked ‘sickness’-dimension of health, namely employment behaviour among people with illnesses. We use European Union Statistics on Income and Living Conditions (EU-SILC) data from 2005 covering 26 European countries linked to country characteristics derived...

  4. [Workplace bullying and sickness absenteeism].

    Science.gov (United States)

    Campanini, Paolo; Conway, Paul Maurice; Neri, Luca; Punzi, Silvia; Camerino, Donatella; Costa, Giovanni

    2013-01-01

    To assess the relationship between workplace bullying and sickness absenteeism in a large sample of Italian workers. A cross-sectional study conducted by means of questionnaires. In all, 8,992 subjects filled in a questionnaire to detect workplace bullying, the presence of work stress factors and days of sickness absence in the last year. Workplace bullying and psychosocial stressor were measured by the means of the CDL 2.0 questionnaire. Days of sickness absence reported by the subjects. On average, days of sickness absence were 7.4, and 7.2% of the respondents were defined as bullied. Results from logistic regression analyses showed that a workplace bullying was associated with more days of sickness absence after controlling for gender, age, professional qualification, company sector and juridical nature and other psychosocial factors (men: OR =1.62; women: OR =2.15). The present study confirms that workers exposed to a workplace bullying reported higher sickness absenteeism as compared with non-exposed subjects, also when a potentially highly stressful work environment is considered. The results of the present study support that workplace bullying may be viewed as an extreme stressful condition. Interventions to avoid workplace bullying not only favoure workers' health, but also avoid the company costs associated with workers' sickness absenteeism.

  5. Non-retinotopic feature processing in the absence of retinotopic spatial layout and the construction of perceptual space from motion.

    Science.gov (United States)

    Ağaoğlu, Mehmet N; Herzog, Michael H; Oğmen, Haluk

    2012-10-15

    The spatial representation of a visual scene in the early visual system is well known. The optics of the eye map the three-dimensional environment onto two-dimensional images on the retina. These retinotopic representations are preserved in the early visual system. Retinotopic representations and processing are among the most prevalent concepts in visual neuroscience. However, it has long been known that a retinotopic representation of the stimulus is neither sufficient nor necessary for perception. Saccadic Stimulus Presentation Paradigm and the Ternus-Pikler displays have been used to investigate non-retinotopic processes with and without eye movements, respectively. However, neither of these paradigms eliminates the retinotopic representation of the spatial layout of the stimulus. Here, we investigated how stimulus features are processed in the absence of a retinotopic layout and in the presence of retinotopic conflict. We used anorthoscopic viewing (slit viewing) and pitted a retinotopic feature-processing hypothesis against a non-retinotopic feature-processing hypothesis. Our results support the predictions of the non-retinotopic feature-processing hypothesis and demonstrate the ability of the visual system to operate non-retinotopically at a fine feature processing level in the absence of a retinotopic spatial layout. Our results suggest that perceptual space is actively constructed from the perceptual dimension of motion. The implications of these findings for normal ecological viewing conditions are discussed. 2012 Elsevier Ltd. All rights reserved

  6. Measurements of the internal magnetic field on DIII-D using intensity and spacing of the motional Stark multiplet.

    Science.gov (United States)

    Pablant, N A; Burrell, K H; Groebner, R J; Kaplan, D H; Holcomb, C T

    2008-10-01

    We describe a version of a motional Stark effect (MSE) diagnostic based on the relative line intensities and spacing of Stark split D(alpha) emission from the neutral beams. This system, named B-Stark, has been recently installed on the DIII-D tokamak. To find the magnetic pitch angle, we use the ratio of the intensities of the pi(3) and sigma(1) lines. These lines originate from the same upper level and so are not dependent on the level populations. In future devices, such as ITER, this technique may have advantages over diagnostics based on MSE polarimetry. We have done an optimization of the viewing direction for the available ports on DIII-D to choose the installation location. With this placement, we have a near optimal viewing angle of 59.6 degrees from the vertical direction. All hardware has been installed for one chord, and we have been routinely taking data since January 2007. We fit the spectra using a simple Stark model in which the upper level populations of the D(alpha) transition are treated as free variables. The magnitude and direction of the magnetic field obtained using this diagnostic technique compare well with measurements from MSE polarimetry and EFIT.

  7. Three-directional motion compensation-based novel-look-up-table for video hologram generation of three-dimensional objects freely maneuvering in space.

    Science.gov (United States)

    Dong, Xiao-Bin; Kim, Seung-Cheol; Kim, Eun-Soo

    2014-07-14

    A new three-directional motion compensation-based novel-look-up-table (3DMC-NLUT) based on its shift-invariance and thin-lens properties, is proposed for video hologram generation of three-dimensional (3-D) objects moving with large depth variations in space. The input 3-D video frames are grouped into a set of eight in sequence, where the first and remaining seven frames in each set become the reference frame (RF) and general frames (GFs), respectively. Hence, each 3-D video frame is segmented into a set of depth-sliced object images (DOIs). Then x, y, and z-directional motion vectors are estimated from blocks and DOIs between the RF and each of the GFs, respectively. With these motion vectors, object motions in space are compensated. Then, only the difference images between the 3-directionally motion-compensated RF and each of the GFs are applied to the NLUT for hologram calculation. Experimental results reveal that the average number of calculated object points and the average calculation time of the proposed method have been reduced compared to those of the conventional NLUT, TR-NLUT and MPEG-NLUT by 38.14%, 69.48%, and 67.41% and 35.30%, 66.39%, and 64.46%, respectively.

  8. Industrial Sickness in Indian Manufacturing

    OpenAIRE

    Falk, Rahel

    2005-01-01

    In India, the term ‘sick units’ refers to economically unviable firms which are kept alive ‘in the public interest’ by means of subsidies of various kinds. Since this practice is common, and large parts of the industrial sector are affected, this phenomenon is referred to as industrial sickness. As of March 2001, the Reserve Bank of India counted over a quarter of a million of sick units with outstanding credit worth more than a quarter of a trillion of Indian Rupees, i.e. about 1.2 percent o...

  9. Human Perception of Ambiguous Inertial Motion Cues

    Science.gov (United States)

    Zhang, Guan-Lu

    2010-01-01

    Human daily activities on Earth involve motions that elicit both tilt and translation components of the head (i.e. gazing and locomotion). With otolith cues alone, tilt and translation can be ambiguous since both motions can potentially displace the otolithic membrane by the same magnitude and direction. Transitions between gravity environments (i.e. Earth, microgravity and lunar) have demonstrated to alter the functions of the vestibular system and exacerbate the ambiguity between tilt and translational motion cues. Symptoms of motion sickness and spatial disorientation can impair human performances during critical mission phases. Specifically, Space Shuttle landing records show that particular cases of tilt-translation illusions have impaired the performance of seasoned commanders. This sensorimotor condition is one of many operational risks that may have dire implications on future human space exploration missions. The neural strategy with which the human central nervous system distinguishes ambiguous inertial motion cues remains the subject of intense research. A prevailing theory in the neuroscience field proposes that the human brain is able to formulate a neural internal model of ambiguous motion cues such that tilt and translation components can be perceptually decomposed in order to elicit the appropriate bodily response. The present work uses this theory, known as the GIF resolution hypothesis, as the framework for experimental hypothesis. Specifically, two novel motion paradigms are employed to validate the neural capacity of ambiguous inertial motion decomposition in ground-based human subjects. The experimental setup involves the Tilt-Translation Sled at Neuroscience Laboratory of NASA JSC. This two degree-of-freedom motion system is able to tilt subjects in the pitch plane and translate the subject along the fore-aft axis. Perception data will be gathered through subject verbal reports. Preliminary analysis of perceptual data does not indicate that

  10. Late stage infection in sleeping sickness.

    Directory of Open Access Journals (Sweden)

    Hartwig Wolburg

    Full Text Available At the turn of the 19(th century, trypanosomes were identified as the causative agent of sleeping sickness and their presence within the cerebrospinal fluid of late stage sleeping sickness patients was described. However, no definitive proof of how the parasites reach the brain has been presented so far. Analyzing electron micrographs prepared from rodent brains more than 20 days after infection, we present here conclusive evidence that the parasites first enter the brain via the choroid plexus from where they penetrate the epithelial cell layer to reach the ventricular system. Adversely, no trypanosomes were observed within the parenchyma outside blood vessels. We also show that brain infection depends on the formation of long slender trypanosomes and that the cerebrospinal fluid as well as the stroma of the choroid plexus is a hostile environment for the survival of trypanosomes, which enter the pial space including the Virchow-Robin space via the subarachnoid space to escape degradation. Our data suggest that trypanosomes do not intend to colonize the brain but reside near or within the glia limitans, from where they can re-populate blood vessels and disrupt the sleep wake cycles.

  11. A Field Study of Performance Among Embarked Infantry Personnel Exposed to Waterborne Motion

    Science.gov (United States)

    2012-09-01

    motion sickness. However, the symptoms associated with these sicknesses may also arise in the absence of motion. Cinema sickness and simulator... identical courses were constructed to facilitate the timely completion of 35 the physical coordination course. Participants with an odd identification...nearly identical to the layout at Pelican Point. Figure 9 shows the detailed course layout superimposed over an aerial view of Red Beach

  12. Spacelab 3 flight experiment No. 3AFT23: Autogenic-feedback training as a preventive method for space adaptation syndrome

    Science.gov (United States)

    Cowings, Patricia S.; Toscano, William B.; Kamiya, Joe; Miller, Neal E.; Sharp, Joseph C.

    1988-01-01

    Space adaptation syndrome is a motion sickness-like disorder which affects up to 50 percent of all people exposed to microgravity in space. This experiment tested a physiological conditioning procedure (Autogenic-Feedback Training, AFT) as an alternative to pharmacological management. Four astronauts participated as subjects in this experiment. Crewmembers A and B served as treatment subjects. Both received preflight training for control of heart rate, respiration rate, peripheral blood volume, and skin conductance. Crewmembers C and D served as controls (i.e., did not receive training). Crewmember A showed reliable control of his own physiological responses, and a significant increase in motion sickness tolerance after training. Crewmember B, however, demonstrated much less control and only a moderate increase in motion sickness tolerance was observed after training. The inflight symptom reports and physiological data recordings revealed that Crewmember A did not experience any severe symptom episodes during the mission, while Crewmember B reported one severe symptom episode. Both control group subjects, C and D (who took antimotion sickness medication), reported multiple symptom episodes on mission day 0. Both inflight data and crew reports indicate that AFT may be an effective countermeasure. Additional data must be obtained inflight (a total of eight treatment and eight control subjects) before final evaluation of this treatment can be made.

  13. HUBBLE SPACE TELESCOPE PROPER MOTION (HSTPROMO) CATALOGS OF GALACTIC GLOBULAR CLUSTERS. I. SAMPLE SELECTION, DATA REDUCTION, AND NGC 7078 RESULTS

    Energy Technology Data Exchange (ETDEWEB)

    Bellini, A.; Anderson, J.; Van der Marel, R. P.; Watkins, L. L. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); King, I. R. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Bianchini, P. [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Chanamé, J. [Instituto de Astrofísica, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Macul 782-0436, Santiago (Chile); Chandar, R. [Department of Physics and Astronomy, The University of Toledo, 2801 West Bancroft Street, Toledo, OH 43606 (United States); Cool, A. M. [Department of Physics and Astronomy, San Francisco State University, 1600 Holloway Avenue, San Francisco, CA 94132 (United States); Ferraro, F. R.; Massari, D. [Dipartimento di Fisica e Astronomia, Università di Bologna, via Ranzani 1, I-40127 Bologna (Italy); Ford, H., E-mail: bellini@stsci.edu [Department of Physics and Astronomy, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States)

    2014-12-20

    We present the first study of high-precision internal proper motions (PMs) in a large sample of globular clusters, based on Hubble Space Telescope (HST) data obtained over the past decade with the ACS/WFC, ACS/HRC, and WFC3/UVIS instruments. We determine PMs for over 1.3 million stars in the central regions of 22 clusters, with a median number of ∼60,000 stars per cluster. These PMs have the potential to significantly advance our understanding of the internal kinematics of globular clusters by extending past line-of-sight (LOS) velocity measurements to two- or three-dimensional velocities, lower stellar masses, and larger sample sizes. We describe the reduction pipeline that we developed to derive homogeneous PMs from the very heterogeneous archival data. We demonstrate the quality of the measurements through extensive Monte Carlo simulations. We also discuss the PM errors introduced by various systematic effects and the techniques that we have developed to correct or remove them to the extent possible. We provide in electronic form the catalog for NGC 7078 (M 15), which consists of 77,837 stars in the central 2.'4. We validate the catalog by comparison with existing PM measurements and LOS velocities and use it to study the dependence of the velocity dispersion on radius, stellar magnitude (or mass) along the main sequence, and direction in the plane of the sky (radial or tangential). Subsequent papers in this series will explore a range of applications in globular-cluster science and will also present the PM catalogs for the other sample clusters.

  14. MR-guided PET motion correction in LOR space using generic projection data for image reconstruction with PRESTO

    International Nuclear Information System (INIS)

    Scheins, J.; Ullisch, M.; Tellmann, L.; Weirich, C.; Rota Kops, E.; Herzog, H.; Shah, N.J.

    2013-01-01

    The BrainPET scanner from Siemens, designed as hybrid MR/PET system for simultaneous acquisition of both modalities, provides high-resolution PET images with an optimum resolution of 3 mm. However, significant head motion often compromises the achievable image quality, e.g. in neuroreceptor studies of human brain. This limitation can be omitted when tracking the head motion and accurately correcting measured Lines-of-Response (LORs). For this purpose, we present a novel method, which advantageously combines MR-guided motion tracking with the capabilities of the reconstruction software PRESTO (PET Reconstruction Software Toolkit) to convert motion-corrected LORs into highly accurate generic projection data. In this way, the high-resolution PET images achievable with PRESTO can also be obtained in presence of severe head motion

  15. Constraints on the nature of inertial motion arising from the universality of free fall and the conformal causal structure of space-time

    International Nuclear Information System (INIS)

    Coleman, R.A.; Korte, H.

    1984-01-01

    According to the principle of the universality of free fall, the motions of all neutral monopole particles are governed by one common path structure. This principle does not, however, require the path structure to be geodesic; that is, the path structure need not be a projective structure. It is shown that any equation of motion structure (either a curve or a path structure) that has sufficient microisotropy to be compatible with the conformal causal structure of space-time must be geodesic and must be unique. Hence, the empirically well-supported principles of conformal causality and of the universality of free fall together require the existence of a unique Weyl structure on space-time

  16. Effects of C5/C6 Intervertebral Space Distraction Height on Pressure on the Adjacent Intervertebral Disks and Articular Processes and Cervical Vertebrae Range of Motion.

    Science.gov (United States)

    Lu, Tingsheng; Luo, Chunshan; Ouyang, Beiping; Chen, Qiling; Deng, Zhongliang

    2018-04-25

    BACKGROUND This study aimed to investigate the association between range of motion of the cervical vertebrae and various C5/C6 intervertebral space distraction heights. MATERIAL AND METHODS The cervical vertebrae from 6 fresh adult human cadavers were used to prepare the models. Changes in C4/C5 and C6/C7 intervertebral disk pressures, articular process pressure, and range of motion of the cervical vertebrae before and after the distraction of the C5/C6 intervertebral space at benchmark heights of 100%, 120%, 140%, and 160% were tested under different exercise loads. RESULTS The pressure on the adjacent intervertebral disks was highest with the standing upright position before distraction, varied with different positions of the specimens and distraction heights after distraction, and was closest to that before distraction at a distraction height of 120% (Particular processes was highest with left and right rotations before distraction, varied with different positions of the specimens and distraction heights after distraction, and was lowest under the same exercise load with different positions at a distraction height of 120% (Pdistraction and at a distraction height of 120% after distraction, respectively (Particular processes and range of motion of the cervical vertebrae and is therefore an appropriate intervertebral space distraction height.

  17. The sick-building syndrome; Das Sick-Building-Syndrom

    Energy Technology Data Exchange (ETDEWEB)

    Henne, A.; Neumann, H.F.; Winneke, G.

    1992-12-31

    The sick-building syndrome is characterized by the presence of general, non-specific symptoms (e.g., headache, tiredness, respiratory problems, eye trouble, vertigo, nausea, unspecific hypersensitivity) in association with a particular indoor ambience. It is clearly distinguishable from `building-related illness`, referring to a well-defined clinical syndrome due to staying in a building and for which a cause can, in general, be established. Disorders in the case of the sick-building syndrome are manifold and confirmed objectifiable results are hardly available so far. Yet there are some organ-related methods for the confirmation of findings concerning, for instance, the eyes, the skin and the area of the nose. The causes of the incidence of sick-building syndrome are more or less unclear. It is a multifactorial phenomenon involving physical, biological, chemical, individual-specific and psychological factors. Buildings where sick-building syndrome occurs typically exhibit certain properties. The European Community has already made proposals for the investigation of incriminated buildings. A systematic survey by questionnaire together with individual interviews plays an import part towards clarifying the syndrome. (orig./UWA) [Deutsch] Das Sick-Building-Syndrom beschreibt das Vorhandensein von allgemeinen, nicht spezifischen Symptomen (z.B. Kopfschmerzen, Muedigkeit, Atembeschwerden, Augenreizungen, Schwindelgefuehl, Uebelkeit, unspezifische Ueberempfindlichkeit), assoziiert mit einer besonderen Innenraumumgebung. Deutlich hiervon abzugrenzen ist die ``Building related illness``, bei der ein klinisch definiertes Krankheitsbild vorliegt, das durch den Aufenthalt im Gebaeude verursacht wird und fuer das im allgemeinen eine Ursache ermittelt werden kann. Das Beschwerdebild beim Sick-Building-Syndrom ist vielfaeltig, und gesicherte, objektivierbare Befunde liegen hierzu bisher kaum vor. Dennoch gibt es einige organbezogenen Methoden zur Befundabsicherung, z.B. fuer das

  18. Sleeping Sickness Surveillance In The Abraka Sleeping Sickness ...

    African Journals Online (AJOL)

    Confirmation of sleeping sickness (ss) was by the detection of trypanosomes in blood, body fluids and biopsy tissues. Thirteen (0.8%) seropositive subjects were parasitologically confirmed and treated with melasoprol at the Baptist Medical Centre (BMC) Eku. One (0.06%) patient died during the course of treatment.

  19. Micro-calibration of space and motion by photoreceptors synchronized in parallel with cortical oscillations: A unified theory of visual perception.

    Science.gov (United States)

    Jerath, Ravinder; Cearley, Shannon M; Barnes, Vernon A; Jensen, Mike

    2018-01-01

    A fundamental function of the visual system is detecting motion, yet visual perception is poorly understood. Current research has determined that the retina and ganglion cells elicit responses for motion detection; however, the underlying mechanism for this is incompletely understood. Previously we proposed that retinogeniculo-cortical oscillations and photoreceptors work in parallel to process vision. Here we propose that motion could also be processed within the retina, and not in the brain as current theory suggests. In this paper, we discuss: 1) internal neural space formation; 2) primary, secondary, and tertiary roles of vision; 3) gamma as the secondary role; and 4) synchronization and coherence. Movement within the external field is instantly detected by primary processing within the space formed by the retina, providing a unified view of the world from an internal point of view. Our new theory begins to answer questions about: 1) perception of space, erect images, and motion, 2) purpose of lateral inhibition, 3) speed of visual perception, and 4) how peripheral color vision occurs without a large population of cones located peripherally in the retina. We explain that strong oscillatory activity influences on brain activity and is necessary for: 1) visual processing, and 2) formation of the internal visuospatial area necessary for visual consciousness, which could allow rods to receive precise visual and visuospatial information, while retinal waves could link the lateral geniculate body with the cortex to form a neural space formed by membrane potential-based oscillations and photoreceptors. We propose that vision is tripartite, with three components that allow a person to make sense of the world, terming them "primary, secondary, and tertiary roles" of vision. Finally, we propose that Gamma waves that are higher in strength and volume allow communication among the retina, thalamus, and various areas of the cortex, and synchronization brings cortical

  20. Stream/Bounce Event Perception Reveals a Temporal Limit of Motion Correspondence Based on Surface Feature over Space and Time

    Directory of Open Access Journals (Sweden)

    Yousuke Kawachi

    2011-06-01

    Full Text Available We examined how stream/bounce event perception is affected by motion correspondence based on the surface features of moving objects passing behind an occlusion. In the stream/bounce display two identical objects moving across each other in a two-dimensional display can be perceived as either streaming through or bouncing off each other at coincidence. Here, surface features such as colour (Experiments 1 and 2 or luminance (Experiment 3 were switched between the two objects at coincidence. The moment of coincidence was invisible to observers due to an occluder. Additionally, the presentation of the moving objects was manipulated in duration after the feature switch at coincidence. The results revealed that a postcoincidence duration of approximately 200 ms was required for the visual system to stabilize judgments of stream/bounce events by determining motion correspondence between the objects across the occlusion on the basis of the surface feature. The critical duration was similar across motion speeds of objects and types of surface features. Moreover, controls (Experiments 4a–4c showed that cognitive bias based on feature (colour/luminance congruency across the occlusion could not fully account for the effects of surface features on the stream/bounce judgments. We discuss the roles of motion correspondence, visual feature processing, and attentive tracking in the stream/bounce judgments.

  1. Ambiguous Tilt and Translation Motion Cues after Space Flight and Otolith Assessment during Post-Flight Re-Adaptation

    Science.gov (United States)

    Wood, Scott J.; Clarke, A. H.; Harm, D. L.; Rupert, A. H.; Clement, G. R.

    2009-01-01

    Adaptive changes during space flight in how the brain integrates vestibular cues with other sensory information can lead to impaired movement coordination, vertigo, spatial disorientation and perceptual illusions following Gtransitions. These studies are designed to examine both the physiological basis and operational implications for disorientation and tilt-translation disturbances following short duration space flights.

  2. Visual-vestibular integration motion perception reporting

    Science.gov (United States)

    Harm, Deborah L.; Reschke, Millard R.; Parker, Donald E.

    1999-01-01

    Self-orientation and self/surround-motion perception derive from a multimodal sensory process that integrates information from the eyes, vestibular apparatus, proprioceptive and somatosensory receptors. Results from short and long duration spaceflight investigations indicate that: (1) perceptual and sensorimotor function was disrupted during the initial exposure to microgravity and gradually improved over hours to days (individuals adapt), (2) the presence and/or absence of information from different sensory modalities differentially affected the perception of orientation, self-motion and surround-motion, (3) perceptual and sensorimotor function was initially disrupted upon return to Earth-normal gravity and gradually recovered to preflight levels (individuals readapt), and (4) the longer the exposure to microgravity, the more complete the adaptation, the more profound the postflight disturbances, and the longer the recovery period to preflight levels. While much has been learned about perceptual and sensorimotor reactions and adaptation to microgravity, there is much remaining to be learned about the mechanisms underlying the adaptive changes, and about how intersensory interactions affect perceptual and sensorimotor function during voluntary movements. During space flight, SMS and perceptual disturbances have led to reductions in performance efficiency and sense of well-being. During entry and immediately after landing, such disturbances could have a serious impact on the ability of the commander to land the Orbiter and on the ability of all crew members to egress from the Orbiter, particularly in a non-nominal condition or following extended stays in microgravity. An understanding of spatial orientation and motion perception is essential for developing countermeasures for Space Motion Sickness (SMS) and perceptual disturbances during spaceflight and upon return to Earth. Countermeasures for optimal performance in flight and a successful return to Earth require

  3. Real-time prediction and gating of respiratory motion in 3D space using extended Kalman filters and Gaussian process regression network

    Science.gov (United States)

    Bukhari, W.; Hong, S.-M.

    2016-03-01

    The prediction as well as the gating of respiratory motion have received much attention over the last two decades for reducing the targeting error of the radiation treatment beam due to respiratory motion. In this article, we present a real-time algorithm for predicting respiratory motion in 3D space and realizing a gating function without pre-specifying a particular phase of the patient’s breathing cycle. The algorithm, named EKF-GPRN+ , first employs an extended Kalman filter (EKF) independently along each coordinate to predict the respiratory motion and then uses a Gaussian process regression network (GPRN) to correct the prediction error of the EKF in 3D space. The GPRN is a nonparametric Bayesian algorithm for modeling input-dependent correlations between the output variables in multi-output regression. Inference in GPRN is intractable and we employ variational inference with mean field approximation to compute an approximate predictive mean and predictive covariance matrix. The approximate predictive mean is used to correct the prediction error of the EKF. The trace of the approximate predictive covariance matrix is utilized to capture the uncertainty in EKF-GPRN+ prediction error and systematically identify breathing points with a higher probability of large prediction error in advance. This identification enables us to pause the treatment beam over such instances. EKF-GPRN+ implements a gating function by using simple calculations based on the trace of the predictive covariance matrix. Extensive numerical experiments are performed based on a large database of 304 respiratory motion traces to evaluate EKF-GPRN+ . The experimental results show that the EKF-GPRN+ algorithm reduces the patient-wise prediction error to 38%, 40% and 40% in root-mean-square, compared to no prediction, at lookahead lengths of 192 ms, 384 ms and 576 ms, respectively. The EKF-GPRN+ algorithm can further reduce the prediction error by employing the gating function, albeit

  4. Real-time prediction and gating of respiratory motion in 3D space using extended Kalman filters and Gaussian process regression network

    International Nuclear Information System (INIS)

    Bukhari, W; Hong, S-M

    2016-01-01

    The prediction as well as the gating of respiratory motion have received much attention over the last two decades for reducing the targeting error of the radiation treatment beam due to respiratory motion. In this article, we present a real-time algorithm for predicting respiratory motion in 3D space and realizing a gating function without pre-specifying a particular phase of the patient’s breathing cycle. The algorithm, named EKF-GPRN +  , first employs an extended Kalman filter (EKF) independently along each coordinate to predict the respiratory motion and then uses a Gaussian process regression network (GPRN) to correct the prediction error of the EKF in 3D space. The GPRN is a nonparametric Bayesian algorithm for modeling input-dependent correlations between the output variables in multi-output regression. Inference in GPRN is intractable and we employ variational inference with mean field approximation to compute an approximate predictive mean and predictive covariance matrix. The approximate predictive mean is used to correct the prediction error of the EKF. The trace of the approximate predictive covariance matrix is utilized to capture the uncertainty in EKF-GPRN + prediction error and systematically identify breathing points with a higher probability of large prediction error in advance. This identification enables us to pause the treatment beam over such instances. EKF-GPRN + implements a gating function by using simple calculations based on the trace of the predictive covariance matrix. Extensive numerical experiments are performed based on a large database of 304 respiratory motion traces to evaluate EKF-GPRN +  . The experimental results show that the EKF-GPRN + algorithm reduces the patient-wise prediction error to 38%, 40% and 40% in root-mean-square, compared to no prediction, at lookahead lengths of 192 ms, 384 ms and 576 ms, respectively. The EKF-GPRN + algorithm can further reduce the prediction error by employing the gating function

  5. Notes on Conservation Laws, Equations of Motion of Matter, and Particle Fields in Lorentzian and Teleparallel de Sitter Space-Time Structures

    Directory of Open Access Journals (Sweden)

    Waldyr A. Rodrigues

    2016-01-01

    Full Text Available We discuss the physics of interacting fields and particles living in a de Sitter Lorentzian manifold (dSLM, a submanifold of a 5-dimensional pseudo-Euclidean (5dPE equipped with a metric tensor inherited from the metric of the 5dPE space. The dSLM is naturally oriented and time oriented and is the arena used to study the energy-momentum conservation law and equations of motion for physical systems living there. Two distinct de Sitter space-time structures MdSL and MdSTP are introduced given dSLM, the first equipped with the Levi-Civita connection of its metric field and the second with a metric compatible parallel connection. Both connections are used only as mathematical devices. Thus, for example, MdSL is not supposed to be the model of any gravitational field in the General Relativity Theory (GRT. Misconceptions appearing in the literature concerning the motion of free particles in dSLM are clarified. Komar currents are introduced within Clifford bundle formalism permitting the presentation of Einstein equation as a Maxwell like equation and proving that in GRT there are infinitely many conserved currents. We prove that in GRT even when the appropriate Killing vector fields exist it is not possible to define a conserved energy-momentum covector as in special relativistic theories.

  6. Changes in the dark focus of accommodation associated with simulator sickness

    Science.gov (United States)

    Fowlkes, Jennifer E.; Kennedy, Robert S.; Hettinger, Lawrence J.; Harm, Deborah L.

    1993-01-01

    The relationship between the dark focus of accommodation and simulator sickness, a form of motion sickness, was examined in three experiments. In Experiment 1, dark focus was measured in 18 college students in a laboratory setting before and after they viewed a projected motion scene depicting low altitude helicopter flight. In Experiments 2 and 3, dark focus was measured in pilots (N = 16 and 23, respectively) before and after they 'flew' in moving-base helicopter flight simulators with optical infinity CRT visual systems. The results showed that individuals who experienced simulator sickness had either an inward (myopic) change in dark focus (Experiments 1 and 3) or attenuated outward shifts in dark focus (Experiment 2) relative to participants who did not get sick. These results are consonant with the hypothesis that parasympathetic activity, which may be associated with simulator sickness, should result in changes in dark focus that are in a myopic direction. Night vision goggles, virtual environments, extended periods in microgravity, and heads-up displays all produce related visual symptomatology. Changes in dark focus may occur in these conditions, as well, and should be measured.

  7. The use of adaptation to reduce simulator sickness in driving assessment and research.

    Science.gov (United States)

    Domeyer, Joshua E; Cassavaugh, Nicholas D; Backs, Richard W

    2013-04-01

    The technical advancement of driving simulators has decreased their cost and increased both their accuracy and fidelity. This makes them a useful tool for examining driving behavior in risky or unique situations. With the approaching increase of older licensed drivers due to aging of the baby boomers, driving simulators will be important for conducting driving research and evaluations for older adults. With these simulator technologies, some people may experience significant effects of a unique form of motion sickness, known as simulator sickness. These effects may be more pronounced in older adults. The present study examined the feasibility of an intervention to attenuate symptoms of simulator sickness in drivers participating in a study of a driving evaluation protocol. Prior to beginning the experiment, the experimental groups did not differ in subjective simulator sickness scores as indicated by Revised Simulator Sickness Questionnaire scores (all p>0.5). Participants who experienced a two-day delay between an initial acclimation to the driving simulator and the driving session experienced fewer simulator sickness symptoms as indicated by RSSQ total severity scores than participants who did not receive a two-day delay (F(1,88)=4.54, p=.036, partial η(2)=.049). These findings have implications for improving client well-being and potentially increasing acceptance of driving simulation for driving evaluations and for driving safety research. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Tight or sick building syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Thirumalaikolundusubramanian, P; Shanmuganadan, S [Madurai Kamaraj Univ. (India). Dept. of Geography; Uma, A [Madurai Medical Coll. (India). Dept. of Medicine and Microbiology

    1991-01-01

    Modern buildings are designed with the usual heating, air-conditioning and ventilation equipment. In most of these buildings, air is continuously recirculated and, as a result, workers suffer from tight or sick building syndrome. This syndrome is discussed with reference to symptoms of air contamination, ventilation system standards and research needs. The most common symptoms of tight building syndrome are eye, nose and throat irritation, headache, fatigue, sneezing, difficulty in wearing contact lenses, chest tightness, nausea, dizziness and dermatitis. Symptoms experienced by 50 doctors and 50 paramedical personnel working in an air-conditioned intensive care unit and operating theatres of the Government Rajaji Hospital, Madurai in India were studied by means of a questionnaire survey. In the present study, respiratory and ocular symptoms were observed more in those working in operating theatres and were believed to be due to excessive use of formaldehyde used for sterilization. Various suggestions were made to prevent sick building syndrome. Moreover, the physicians treating sick individuals should be aware of the symptoms caused by indoor air pollutants as sufferers invariably require a change of environment rather than drugs. (orig.).

  9. Respiratory motion-resolved, self-gated 4D-MRI using Rotating Cartesian K-space (ROCK): Initial clinical experience on an MRI-guided radiotherapy system.

    Science.gov (United States)

    Han, Fei; Zhou, Ziwu; Du, Dongsu; Gao, Yu; Rashid, Shams; Cao, Minsong; Shaverdian, Narek; Hegde, John V; Steinberg, Michael; Lee, Percy; Raldow, Ann; Low, Daniel A; Sheng, Ke; Yang, Yingli; Hu, Peng

    2018-06-01

    To optimize and evaluate the respiratory motion-resolved, self-gated 4D-MRI using Rotating Cartesian K-space (ROCK-4D-MRI) method in a 0.35 T MRI-guided radiotherapy (MRgRT) system. The study included seven patients with abdominal tumors treated on the MRgRT system. ROCK-4D-MRI and 2D-CINE, was performed immediately after one of the treatment fractions. Motion quantification based on 4D-MRI was compared with those based on 2D-CINE. The image quality of 4D-MRI was evaluated against 4D-CT. The gross tumor volumes (GTV) were defined based on individual respiratory phases of both 4D-MRI and 4D-CT and compared for their variability over the respiratory cycle. The motion measurements based on 4D-MRI matched well with 2D-CINE, with differences of 1.04 ± 0.52 mm in the superior-inferior and 0.54 ± 0.21 mm in the anterior-posterior directions. The image quality scores of 4D-MRI were significantly higher than 4D-CT, with better tumor contrast (3.29 ± 0.76 vs. 1.86 ± 0.90) and less motion artifacts (3.57 ± 0.53 vs. 2.29 ± 0.95). The GTVs were more consistent in 4D-MRI than in 4D-CT, with significantly smaller GTV variability (9.31 ± 4.58% vs. 34.27 ± 23.33%). Our study demonstrated the clinical feasibility of using the ROCK-4D-MRI to acquire high quality, respiratory motion-resolved 4D-MRI in a low-field MRgRT system. The 4D-MRI image could provide accurate dynamic information for radiotherapy treatment planning. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. A method for simulating sediment incipient motion varying with time and space in an ocean model (FVCOM): development and validation

    Science.gov (United States)

    Zhu, Zichen; Wang, Yongzhi; Bian, Shuhua; Hu, Zejian; Liu, Jianqiang; Liu, Lejun

    2017-11-01

    We modified the sediment incipient motion in a numerical model and evaluated the impact of this modification using a study case of the coastal area around Weihai, China. The modified and unmodified versions of the model were validated by comparing simulated and observed data of currents, waves, and suspended sediment concentrations (SSC) measured from July 25th to July 26th, 2006. A fitted Shields diagram was introduced into the sediment model so that the critical erosional shear stress could vary with time. Thus, the simulated SSC patterns were improved to more closely reflect the observed values, so that the relative error of the variation range decreased by up to 34.5% and the relative error of simulated temporally averaged SSC decreased by up to 36%. In the modified model, the critical shear stress values of the simulated silt with a diameter of 0.035 mm and mud with a diameter of 0.004 mm varied from 0.05 to 0.13 N/m2, and from 0.05 to 0.14 N/m 2, respectively, instead of remaining constant in the unmodified model. Besides, a method of applying spatially varying fractions of the mixed grain size sediment improved the simulated SSC distribution to fit better to the remote sensing map and reproduced the zonal area with high SSC between Heini Bay and the erosion groove in the modified model. The Relative Mean Absolute Error was reduced by between 6% and 79%, depending on the regional attributes when we used the modified method to simulate incipient sediment motion. But the modification achieved the higher accuracy in this study at a cost of computation speed decreasing by 1.52%.

  11. Clinical characteristics of subacute radiation sickness

    International Nuclear Information System (INIS)

    Jiang Benrong; Ye Genyao; Huang Shimin

    1991-01-01

    The clinical characteristics, diagnosis and differential diagnosis of subacute radiation sickness are analysed and discussed in this paper on the basis of clinical data from cases in a 137 Cs source accident in Mudanjiang and of a review of the literature. We consider that the subacute radiation sickness is a whole body disease caused by comparatively large dose of continuous or intermittent external irradiation in several weeks or months. it must be differentiated from acute radiation sickness, chronic radiation sickness, idiopathic aplastic anemia and other hematological diseases, such as paroxysmal nocturnal hemoglobinuria, acute leukemia and myelodysplastic syndrome

  12. General practitioners' use of sickness certificates.

    Science.gov (United States)

    Roope, Richard; Parker, Gordon; Turner, Susan

    2009-12-01

    At present, sickness certification is largely undertaken by general practitioners (GPs). Guidance from the Department of Work and Pensions (DWP) is available to help with this task; however, there has been little formal evaluation of the DWP's guidance in relation to day-to-day general practice. To assess GPs' training, knowledge and application of the DWP's sickness certification guidelines. A structured questionnaire was sent to GPs within a (former) primary care trust (PCT). It probed demographics, training and knowledge of sickness certification guidelines. Case histories and structured questions were used to assess current practice. In this group of 113 GPs, there was a low awareness and use of the DWP's guidelines and Website relating to sickness certification. The majority of the GPs (63%) had received no training in sickness certification, and the mean length of time for those who had received training was 4.1 h. Most GPs also felt that patients and GPs have equal influence on the duration of sickness certification. This evidence of variable practice indicates that GPs should have more guidance and education in sickness certification. Closer sickness certification monitoring through existing GP computer systems may facilitate an improvement in practice that benefits patients and employers. The DWP, medical educators and PCTs may all have an additional role in further improving sickness certification practice.

  13. Office design's impact on sick leave rates.

    Science.gov (United States)

    Bodin Danielsson, Christina; Chungkham, Holendro Singh; Wulff, Cornelia; Westerlund, Hugo

    2014-01-01

    The effect of office type on sickness absence among office employees was studied prospectively in 1852 employees working in (1) cell-offices; (2) shared-room offices; (3) small, (4) medium-sized and (5) large open-plan offices; (6) flex-offices and (7) combi-offices. Sick leaves were self-reported two years later as number of (a) short and (b) long (medically certified) sick leave spells as well as (c) total number of sick leave days. Multivariate logistic regression analysis was used, with adjustment for background factors. A significant excess risk for sickness absence was found only in terms of short sick leave spells in the three open-plan offices. In the gender separate analysis, this remained for women, whereas men had a significantly increased risk in flex-offices. For long sick leave spells, a significantly higher risk was found among women in large open-plan offices and for total number of sick days among men in flex-offices. A prospective study of the office environment's effect on employees is motivated by the high rates of sick leaves in the workforce. The results indicate differences between office types, depending on the number of people sharing workspace and the opportunity to exert personal control as influenced by the features that define the office types.

  14. A theoretical understanding of sickness absence among women who have experienced workplace bullying.

    Science.gov (United States)

    O'Donnell, Sue; MacIntosh, Judith; Wuest, Judith

    2010-04-01

    Historically, we have assumed that workplaces, where employed individuals spend approximately one third of their days, provide safe and supportive environments and opportunities to enhance women's capacities. Unfortunately, workplace bullying and consequent sickness absence are prevalent and costly realities that significantly influence women's health. In this study, sickness absence among 18 Canadian women who were targets of workplace bullying was explored using a grounded theory secondary analysis. Findings show that although sickness absence is critical in attenuating the health consequences of being bullied, it is a partial solution because rehabilitation and successful return to work is challenged when working conditions remain unchanged. This problem is addressed using is a three-stage process of discerning a path that involves gaining space, making sense, and moving forward. Organizational support is critical to all stages of the process; it can reduce the risk of declines in health and sickness absence, and is essential for successful return to work.

  15. sick: The Spectroscopic Inference Crank

    Science.gov (United States)

    Casey, Andrew R.

    2016-03-01

    There exists an inordinate amount of spectral data in both public and private astronomical archives that remain severely under-utilized. The lack of reliable open-source tools for analyzing large volumes of spectra contributes to this situation, which is poised to worsen as large surveys successively release orders of magnitude more spectra. In this article I introduce sick, the spectroscopic inference crank, a flexible and fast Bayesian tool for inferring astrophysical parameters from spectra. sick is agnostic to the wavelength coverage, resolving power, or general data format, allowing any user to easily construct a generative model for their data, regardless of its source. sick can be used to provide a nearest-neighbor estimate of model parameters, a numerically optimized point estimate, or full Markov Chain Monte Carlo sampling of the posterior probability distributions. This generality empowers any astronomer to capitalize on the plethora of published synthetic and observed spectra, and make precise inferences for a host of astrophysical (and nuisance) quantities. Model intensities can be reliably approximated from existing grids of synthetic or observed spectra using linear multi-dimensional interpolation, or a Cannon-based model. Additional phenomena that transform the data (e.g., redshift, rotational broadening, continuum, spectral resolution) are incorporated as free parameters and can be marginalized away. Outlier pixels (e.g., cosmic rays or poorly modeled regimes) can be treated with a Gaussian mixture model, and a noise model is included to account for systematically underestimated variance. Combining these phenomena into a scalar-justified, quantitative model permits precise inferences with credible uncertainties on noisy data. I describe the common model features, the implementation details, and the default behavior, which is balanced to be suitable for most astronomical applications. Using a forward model on low-resolution, high signal

  16. SICK: THE SPECTROSCOPIC INFERENCE CRANK

    Energy Technology Data Exchange (ETDEWEB)

    Casey, Andrew R., E-mail: arc@ast.cam.ac.uk [Institute of Astronomy, University of Cambridge, Madingley Road, Cambdridge, CB3 0HA (United Kingdom)

    2016-03-15

    There exists an inordinate amount of spectral data in both public and private astronomical archives that remain severely under-utilized. The lack of reliable open-source tools for analyzing large volumes of spectra contributes to this situation, which is poised to worsen as large surveys successively release orders of magnitude more spectra. In this article I introduce sick, the spectroscopic inference crank, a flexible and fast Bayesian tool for inferring astrophysical parameters from spectra. sick is agnostic to the wavelength coverage, resolving power, or general data format, allowing any user to easily construct a generative model for their data, regardless of its source. sick can be used to provide a nearest-neighbor estimate of model parameters, a numerically optimized point estimate, or full Markov Chain Monte Carlo sampling of the posterior probability distributions. This generality empowers any astronomer to capitalize on the plethora of published synthetic and observed spectra, and make precise inferences for a host of astrophysical (and nuisance) quantities. Model intensities can be reliably approximated from existing grids of synthetic or observed spectra using linear multi-dimensional interpolation, or a Cannon-based model. Additional phenomena that transform the data (e.g., redshift, rotational broadening, continuum, spectral resolution) are incorporated as free parameters and can be marginalized away. Outlier pixels (e.g., cosmic rays or poorly modeled regimes) can be treated with a Gaussian mixture model, and a noise model is included to account for systematically underestimated variance. Combining these phenomena into a scalar-justified, quantitative model permits precise inferences with credible uncertainties on noisy data. I describe the common model features, the implementation details, and the default behavior, which is balanced to be suitable for most astronomical applications. Using a forward model on low-resolution, high signal

  17. SICK: THE SPECTROSCOPIC INFERENCE CRANK

    International Nuclear Information System (INIS)

    Casey, Andrew R.

    2016-01-01

    There exists an inordinate amount of spectral data in both public and private astronomical archives that remain severely under-utilized. The lack of reliable open-source tools for analyzing large volumes of spectra contributes to this situation, which is poised to worsen as large surveys successively release orders of magnitude more spectra. In this article I introduce sick, the spectroscopic inference crank, a flexible and fast Bayesian tool for inferring astrophysical parameters from spectra. sick is agnostic to the wavelength coverage, resolving power, or general data format, allowing any user to easily construct a generative model for their data, regardless of its source. sick can be used to provide a nearest-neighbor estimate of model parameters, a numerically optimized point estimate, or full Markov Chain Monte Carlo sampling of the posterior probability distributions. This generality empowers any astronomer to capitalize on the plethora of published synthetic and observed spectra, and make precise inferences for a host of astrophysical (and nuisance) quantities. Model intensities can be reliably approximated from existing grids of synthetic or observed spectra using linear multi-dimensional interpolation, or a Cannon-based model. Additional phenomena that transform the data (e.g., redshift, rotational broadening, continuum, spectral resolution) are incorporated as free parameters and can be marginalized away. Outlier pixels (e.g., cosmic rays or poorly modeled regimes) can be treated with a Gaussian mixture model, and a noise model is included to account for systematically underestimated variance. Combining these phenomena into a scalar-justified, quantitative model permits precise inferences with credible uncertainties on noisy data. I describe the common model features, the implementation details, and the default behavior, which is balanced to be suitable for most astronomical applications. Using a forward model on low-resolution, high signal

  18. Indoor air pollution and sick building syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, J P

    1997-12-31

    The topics discussed in this paper are accept that SBS (Sick building syndrome) is a reality ; understand the dimensions of the problem ; differentiate between sick building syndrome and building related illness ; introduce standards ; understanding the economics ; act pro-actively not re-actively.

  19. GENETIC PREDICTORS OF IDIOPATHIC SICK SINUS SYNDROME

    Directory of Open Access Journals (Sweden)

    A. A. Chernova

    2012-01-01

    Full Text Available Published data demonstrating genetic determination of sick sinus syndrome is presented. The definition of this pathology is presented; the main symptoms are described, as well as genes that influence the development of idiopathic sick sinus syndrome, their polymorphisms and role in disorders of the cardiovascular system.

  20. Indoor air pollution and sick building syndrome

    International Nuclear Information System (INIS)

    Robertson, J.P.

    1996-01-01

    The topics discussed in this paper are accept that SBS (Sick building syndrome) is a reality ; understand the dimensions of the problem ; differentiate between sick building syndrome and building related illness ; introduce standards ; understanding the economics ; act pro-actively not re-actively

  1. Job demands, health perception and sickness absence

    NARCIS (Netherlands)

    Roelen, C.A.; Koopmans, P.C.; de Graaf, J.H.; van Zandbergen, J.W.; Groothoff, J.W.

    2007-01-01

    Background Investigation of the relations between job demands, health and sickness absence is required to design a strategy for the prevention of absence and disability. Aim To study the relationships between (physical and psychological) job demands, health perception and sickness absence. Methods

  2. Examining paid sickness absence by shift workers.

    Science.gov (United States)

    Catano, V M; Bissonnette, A B

    2014-06-01

    Shift workers are at greater risk than day workers with respect to psychological and physical health, yet little research has linked shift work to increased sickness absence. To investigate the relationship between shift work and sickness absence while controlling for organizational and individual characteristics and shift work attributes that have confounded previous research. The study used archive data collected from three national surveys in Canada, each involving over 20000 employees and 6000 private-sector firms in 14 different occupational groups. The employees reported the number of paid sickness absence days in the past 12 months. Data were analysed using both chi-squared statistics and hierarchical regressions. Contrary to previous research, shift workers took less paid sickness absence than day workers. There were no differences in the length of the sickness absence between both groups or in sickness absence taken by female and male workers whether working days or shifts. Only job tenure, the presence of a union in the workplace and working rotating shifts predicted sickness absence in shift workers. The results were consistent across all three samples. In general, shift work does not seem to be linked to increased sickness absence. However, such associations may be true for specific industries. Male and female workers did not differ in the amount of sickness absence taken. Rotating shifts, regardless of industry, predicted sickness absence among shift workers. Consideration should be given to implementing scheduled time off between shift changes. © The Author 2014. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Post-Newtonian equations of motion for LEO debris objects and space-based acquisition, pointing and tracking laser systems

    Science.gov (United States)

    Gambi, J. M.; García del Pino, M. L.; Gschwindl, J.; Weinmüller, E. B.

    2017-12-01

    This paper deals with the problem of throwing middle-sized low Earth orbit debris objects into the atmosphere via laser ablation. The post-Newtonian equations here provided allow (hypothetical) space-based acquisition, pointing and tracking systems endowed with very narrow laser beams to reach the pointing accuracy presently prescribed. In fact, whatever the orbital elements of these objects may be, these equations will allow the operators to account for the corrections needed to balance the deviations of the line of sight directions due to the curvature of the paths the laser beams are to travel along. To minimize the respective corrections, the systems will have to perform initial positioning manoeuvres, and the shooting point-ahead angles will have to be adapted in real time. The enclosed numerical experiments suggest that neglecting these measures will cause fatal errors, due to differences in the actual locations of the objects comparable to their size.

  4. EFFECTS ABILITIES MOTION IN SPACE OF CHILDREN WHO ARE DEAF OR HARD-OF-HEARING, WITHOUT USE OF EYESIGHT

    Directory of Open Access Journals (Sweden)

    Husnija Hasanbegović

    2014-09-01

    Full Text Available This study investigates knowledge on use of body extremities and body in space by children who are deaf or hard-ofhearing. A random sample of 60 participants was used in the study, with chronological age of 6 to 8 years. Experimental group of 30 participants involved pupils who are deaf or hard-of-hearing both male and female who attend school in Sarajevo (Bosnia and Herzegovina. Control group of 30 participants involved pupils who are typically hearing both male and female who were chronologically matched to the participants in the experimental group. Measuring instruments were created for the purpose of extracting quantitative data analysis, scaled from 1 to 5 units of measurement. The results are showed significant differences between children who are deaf or hard-of-hearing and children who are typically hearing (F=23, 08 p=0.00. The children who are deaf or hard-of-hearing showed significantly weaker knowledge of perception of body movements.

  5. EFFECTS ABILITIES MOTION IN SPACE OF CHILDREN WHO ARE DEAF OR HARD-OF-HEARING, WITHOUT USE OF EYESIGHT

    Directory of Open Access Journals (Sweden)

    Husnija Hasanbegović

    2014-09-01

    Full Text Available This study investigates knowledge on use of body extremities and body in space by children who are deaf or hard-of-hearing. A random sample of 60 participants was used in the study, with chronological age of 6 to 8 years. Experimental group of 30 participants involved pupils who are deaf or hard-of-hearing both male and female who attend school in Sarajevo (Bosnia and Herzegovina. Control group of 30 participants involved pupils who are typically hearing both male and female who were chronologically matched to the participants in the experimental group. Measuring instruments were created for the purpose of extracting quantitative data analysis, scaled from 1 to 5 units of measurement. The results are showed significant differences between children who are deaf or hard-of-hearing and children who are typically hearing (F=23, 08 p=0.00. The children who are deaf or hard-of-hearing showed significantly weaker knowledge of perception of body movements.

  6. Acute high-altitude sickness

    Directory of Open Access Journals (Sweden)

    Andrew M. Luks

    2017-02-01

    Full Text Available At any point 1–5 days following ascent to altitudes ≥2500 m, individuals are at risk of developing one of three forms of acute altitude illness: acute mountain sickness, a syndrome of nonspecific symptoms including headache, lassitude, dizziness and nausea; high-altitude cerebral oedema, a potentially fatal illness characterised by ataxia, decreased consciousness and characteristic changes on magnetic resonance imaging; and high-altitude pulmonary oedema, a noncardiogenic form of pulmonary oedema resulting from excessive hypoxic pulmonary vasoconstriction which can be fatal if not recognised and treated promptly. This review provides detailed information about each of these important clinical entities. After reviewing the clinical features, epidemiology and current understanding of the pathophysiology of each disorder, we describe the current pharmacological and nonpharmacological approaches to the prevention and treatment of these diseases.

  7. Decompression sickness in caisson workers

    Science.gov (United States)

    Ghawabi, Samir H. El; Mansour, Mohamed B.; Youssef, Fatma L.; Ghawabi, Mohamed H. El; Latif, Mohamed M. Abd El

    1971-01-01

    El Ghawabi, S. H., Mansour, M. B., Youssef, F. L., El Ghawabi, M. H., and Abd El Latif, M. M. (1971).Brit. J. industr. Med.,28, 323-329. Decompression sickness in caisson workers. An investigation of 55 bridge construction workers is reported. The overall bends rate was 0·97%. (The term `bends' as used in this study is defined in the paper.) Chokes were encountered in 67·27% of workers. A clinical, haematological, and radiological study was performed. Definite bony changes were found in 43·6% of all workers; 91·6% of these had lesions around the elbow. The presence of dense areas in the neck of the scapula is reported in two cases for the first time. The relatively high haematocrit value is thought to play a part in the pathogenesis of bone infarction through its relation with blood viscosity. Images PMID:5124832

  8. Workplace bullying and sickness presenteeism

    DEFF Research Database (Denmark)

    Conway, Paul Maurice; Clausen, Thomas; Hansen, Åse Marie

    2016-01-01

    Purpose: The aim of this study is to investigate exposure to workplace bullying as a potential risk factor for sickness presenteeism (SP), i.e., working while ill. Methods: This study is based on data collected through self-reported questionnaires in a 2-year prospective study on employees...... with missing values, the final samples were composed of 2,865 and 1,331participants in the cross-sectional and prospective analyses, respectively. Results: Modified poisson regression analyses showed that frequent (i.e., daily or weekly) exposure to workplace bullying was associated with reporting 8 or more...... indications of a significant relationship between exposure to frequent workplace bullying and SP, although causal connections could not be established. Methodological and theoretical considerations about study findings are provided, which could be of benefit to future studies examining the impact of being...

  9. System for analysing sickness absenteeism in Poland.

    Science.gov (United States)

    Indulski, J A; Szubert, Z

    1997-01-01

    The National System of Sickness Absenteeism Statistics has been functioning in Poland since 1977, as the part of the national health statistics. The system is based on a 15-percent random sample of copies of certificates of temporary incapacity for work issued by all health care units and authorised private medical practitioners. A certificate of temporary incapacity for work is received by every insured employee who is compelled to stop working due to sickness, accident, or due to the necessity to care for a sick member of his/her family. The certificate is required on the first day of sickness. Analyses of disease- and accident-related sickness absenteeism carried out each year in Poland within the statistical system lead to the main conclusions: 1. Diseases of the musculoskeletal and peripheral nervous systems accounting, when combined, for 1/3 of the total sickness absenteeism, are a major health problem of the working population in Poland. During the past five years, incapacity for work caused by these diseases in males increased 2.5 times. 2. Circulatory diseases, and arterial hypertension and ischaemic heart disease in particular (41% and 27% of sickness days, respectively), create an essential health problem among males at productive age, especially, in the 40 and older age group. Absenteeism due to these diseases has increased in males more than two times.

  10. Explaining the gender gap in sickness absence.

    Science.gov (United States)

    Østby, K A; Mykletun, A; Nilsen, W

    2018-04-17

    In many western countries, women have a much higher rate of sickness absence than men. To what degree the gender differences in sickness absence are caused by gender differences in health is largely unknown. To assess to what degree the gender gap in sickness absence can be explained by health factors and work- and family-related stressors. Norwegian parents participating in the Tracking Opportunities and Problems (TOPP) study were asked about sickness absence and a range of factors possibly contributing to gender differences in sickness absence, including somatic and mental health, sleep problems, job control/demands, work-home conflicts, parent-child conflicts and stressful life events. Using a cross-sectional design, we did linear regression analyses, to assess the relative contribution from health and stressors. There were 557 study participants. Adjusting for health factors reduced the gender difference in sickness absence by 24%, while adjusting for stressors in the family and at work reduced the difference by 22%. A simultaneous adjustment for health factors and stressors reduced the difference in sickness absence by about 28%. Despite adjusting for a large number of factors, including both previously well-studied factors (e.g. health, job control/demands) and lesser-studied factors (parent-child conflict and sexual assault), this study found that most of the gender gap in sickness absence remains unexplained. Gender differences in health and stressors account for only part of the differences in sickness absence. Other factors must, therefore, exist outside the domains of health, work and family stressors.

  11. Predictors of sickness absence in pregnancy

    DEFF Research Database (Denmark)

    Hansen, Mette Lausten; Thulstrup, Ane Marie; Juhl, Mette

    2014-01-01

    OBJECTIVE: The aim of this cohort study was to investigate associations between parity, pre-pregnancy body mass index (BMI), assisted reproductive therapy (ART), time to pregnancy (TTP), and engagement in physical exercise and the risk of sickness absence in pregnancy from 10-29 completed pregnancy...... with higher HR of sickness absence. Physical exercise of >120 minutes per week was associated with lower HR 0.84 (95% CI 0.75-0.95). CONCLUSION: Risk for sickness absence was higher among women who were multiparous, overweight, obese, received ART, and had prolonged TTP, and lower among women engaged...

  12. Healthy change processes - Relations with job insecurity, sickness absenteeism, sickness presenteeism and turnover intention

    OpenAIRE

    Bødal, Åshild

    2017-01-01

    The aim of this study was to investigate whether the presence of a healthy change process (HCPI) could predict negative outcomes that normally follow organisational change, such as qualitative job insecurity, total sickness (sickness absenteeism and -presenteesim) and turnover intention. It was hypothesised that negative relationships existed between a healthy change process and qualitative job insecurity, total sickness and turnover intention. In addition, it was believed that experienced st...

  13. When healthcare workers get sick: exploring sickness absenteeism in British Columbia, Canada.

    Science.gov (United States)

    Gorman, Erin; Yu, Shicheng; Alamgir, Hasanat

    2010-01-01

    To determine the demographic and work characteristics of healthcare workers who were more likely to take sickness absences from work in British Columbia, Canada. Payroll data were analyzed for three health regions. Sickness absence rates were determined per person-year and then compared across demographic and work characteristics using multivariate Poisson regression models. The direct costs to the employer due to sickness absences were also estimated. Female, older, full-time workers, long-term care workers and those with a lower hourly wage were more likely to take sickness absences and had similar trends with respect to the costs due to sickness absence. For occupations, licensed practical nurses, care aides and facility support workers had higher rates of sickness absence. Registered nurses, and those workers paid high hourly wages were associated with highest sickness related costs. It is important to understand the demographic and work characteristics of those workers who are more likely to take sickness absences in order to make sure that they are not experiencing additional hazards at work or facing detrimental workplace conditions. Policy makers need to establish healthy, safe and in turn more productive workplaces. Further research is needed on how interventions can reduce sickness absence.

  14. [Doctor, may I travel in space? Aeromedical considerations regarding commercial suborbital space flights].

    Science.gov (United States)

    Haerkens, Marck H T M; Simons, Ries; Kuipers, André

    2011-01-01

    Within a few years, the first commercial operators will start flying passengers on suborbital flights to the verge of space. Medical data on the effects of space journeys on humans have mainly been provided by professional astronauts. There is very little research into the aeromedical consequences of suborbital flights for the health of untrained passengers. Low air pressure and oxygen tension can be compensated for by pressurising the spacecraft or pressure suit. Rapid changes in gravitational (G-)force pose ultimate challenges to cardiovascular adaptation mechanisms. Zero-gravity and G-force may cause motion sickness. Vibrations and noise during the flight may disturb communication between passengers and crew. In addition, the psychological impact of a suborbital flight should not be underestimated. There are currently no legal requirements available for medical examinations for commercial suborbital flights, but it seems justifiable to establish conditions for potential passengers' states of health.

  15. Airsickness and aircraft motion during short-haul flights.

    Science.gov (United States)

    Turner, M; Griffin, M J; Holland, I

    2000-12-01

    There is little quantitative information that can be used to predict the incidence of airsickness from the motions experienced in military or civil aviation. This study examines the relationship between low-frequency aircraft motion and passenger sickness in short-haul turboprop flights within the United Kingdom. A questionnaire survey of 923 fare-paying passengers was conducted on 38 commercial airline flights. Concurrent measurements of aircraft motion were made on all journeys, yielding approximately 30 h of aircraft motion data. Overall, 0.5% of passengers reported vomiting, 8.4% reported nausea (range 0% to 34.8%) and 16.2% reported illness (range 0% to 47.8%) during flight. Positive correlations were found between the percentage of passengers who experienced nausea or felt ill and the magnitude of low-frequency lateral and vertical motion, although neither motion uniquely predicted airsickness. The incidence of motion sickness also varied with passenger age, gender, food consumption and activity during air travel. No differences in sickness were found between passengers located in different seating sections of the aircraft, or as a function of moderate levels of alcohol consumption. The passenger responses suggest that a useful prediction of airsickness can be obtained from magnitudes of low frequency aircraft motion. However, some variations in airsickness may also be explained by individual differences between passengers and their psychological perception of flying.

  16. Fundamentals of Space Medicine

    Science.gov (United States)

    Clément, Gilles

    2005-03-01

    A total of more than 240 human space flights have been completed to date, involving about 450 astronauts from various countries, for a combined total presence in space of more than 70 years. The seventh long-duration expedition crew is currently in residence aboard the International Space Station, continuing a permanent presence in space that began in October 2000. During that time, investigations have been conducted on both humans and animal models to study the bone demineralization and muscle deconditioning, space motion sickness, the causes and possible treatment of postflight orthostatic intolerance, the changes in immune function, crew and crew-ground interactions, and the medical issues of living in a space environment, such as the effects of radiation or the risk of developing kidney stones. Some results of these investigations have led to fundamental discoveries about the adaptation of the human body to the space environment. Gilles Clément has been active in this research. This readable text presents the findings from the life science experiments conducted during and after space missions. Topics discussed in this book include: adaptation of sensory-motor, cardio-vascular, bone, and muscle systems to the microgravity of spaceflight; psychological and sociological issues of living in a confined, isolated, and stressful environment; operational space medicine, such as crew selection, training and in-flight health monitoring, countermeasures and support; results of space biology experiments on individual cells, plants, and animal models; and the impact of long-duration missions such as the human mission to Mars. The author also provides a detailed description of how to fly a space experiment, based on his own experience with research projects conducted onboard Salyut-7, Mir, Spacelab, and the Space Shuttle. Now is the time to look at the future of human spaceflight and what comes next. The future human exploration of Mars captures the imagination of both the

  17. Sick of inequality: gender and support for paid sick days.

    Science.gov (United States)

    Lindemann, Danielle J; Houser, Linda; White, Karen

    2015-01-01

    The availability of paid sick days (PSD) is on the forefront of policy issues relating to women's health and well-being. Previous research regarding PSD and other forms of family-work balance legislation has linked access to paid time off from work for addressing one's own or another's health concerns to a range of health benefits for working women and their families. In general, public support for such policies is high, but little work has tested the extent to which support extends to PSD. Researchers have yet to engage in a rigorous statistical analysis of public opinion on PSD, including whether opinion varies by gender. Using data from a 2013 poll of adults in New Jersey (n = 925), we bridged this research gap by conducting the first multivariate analysis of public attitudes toward PSD. As expected, we found markedly high levels of support for PSD across all respondents, with a preponderance of most sociodemographic categories supporting proposed PSD legislation in New Jersey. We also found that gender was a strong predictor of support for PSD, with women significantly (odds ratio, 1.916; p ≤ .01) more likely than men to be in favor of such legislation. We discuss the implications of our findings for future work on PSD as well as for research concerning women, wellness, and work-life legislation more broadly. Published by Elsevier Inc.

  18. ZAG-Otolith: Modification of Otolith-Ocular Reflexes, Motion Perception and Manual Control during Variable Radius Centrifugation Following Space Flight

    Science.gov (United States)

    Wood, S. J.; Clarke, A. H.; Rupert, A. H.; Harm, D. L.; Clement, G. R.

    2009-01-01

    Two joint ESA-NASA studies are examining changes in otolith-ocular reflexes and motion perception following short duration space flights, and the operational implications of post-flight tilt-translation ambiguity for manual control performance. Vibrotactile feedback of tilt orientation is also being evaluated as a countermeasure to improve performance during a closed-loop nulling task. METHODS. Data is currently being collected on astronaut subjects during 3 preflight sessions and during the first 8 days after Shuttle landings. Variable radius centrifugation is utilized to elicit otolith reflexes in the lateral plane without concordant roll canal cues. Unilateral centrifugation (400 deg/s, 3.5 cm radius) stimulates one otolith positioned off-axis while the opposite side is centered over the axis of rotation. During this paradigm, roll-tilt perception is measured using a subjective visual vertical task and ocular counter-rolling is obtained using binocular video-oculography. During a second paradigm (216 deg/s, otolith-mediated reflexes correspond to one's ability to perform closed-loop nulling tasks following G-transitions, and whether manual control performance can be improved with vibrotactile feedback of orientation.

  19. WORRIED SICK? WORKER RESPONSES TO ORGANIZATIONAL TURMOIL

    OpenAIRE

    Bratberg, Espen; Monstad, Karin

    2012-01-01

    Sickness absence has risen over the past years in Norway. One explanation put forward is that a tougher labor market represents a health hazard, while a competing hypothesis predicts that loss of job security works as a disciplinary device. In this analysis we aim to trace a causal impact of organizational turmoil or job insecurity on sickness absence, applying a difference-in-difference approach. Utilizing a negative financial shock that hit specific employers and workplaces, we find that si...

  20. [Sickness absence associated with major life events].

    Science.gov (United States)

    Markussen, Simen; Røgeberg, Ole

    2012-05-29

    Sickness absence in the Norwegian workplace doubled in the period 1993-2003. However, the extent to which the driving factors were medical or non-medical remains unclear, as does the extent to which the cause may be found in the composition of the workforce. A differences-in-differences regression model was used to estimate the added sickness absence associated with major life events such as separation, death of spouse and pregnancy in the period 1993-2005. The data were obtained from administrative registers covering the entire Norwegian population, and include all absence periods of 16 days' duration or more reported by a doctor's medical certificate. The primary outcome measures were incidence (the proportion of absentees in a given time window) and absence (the proportion of sick days in a given time window). The level of absence among employees exposed to the specified life events was compared to control groups matched for gender, age, education and income. In 1993, people in each of the three groups exposed to major life events had more frequent and longer periods of absence than people in the control groups. This added sickness absence increased between 1993 and 2005. The changes in added sickness absence were at times significant, particularly for pregnant women. While sickness absence among pregnant women in 1993 was 15.4 percentage points higher than in the control group, the difference had increased to 24.8 percentage points in 2005. We find it improbable for the increase in added sickness absence to be caused by changes in the medical impact of life events or alterations in the workforce composition. We believe the increase is caused by changing attitudes among the working population and in the medical profession towards sickness absence on grounds that are not strictly medical, combined with improved social acceptance and diagnosis of mental health issues, and/or a medicalisation of natural health variations (pregnancy) and emotional distress (grief).

  1. Nutrition and human physiological adaptations to space flight

    Science.gov (United States)

    Lane, H. W.; LeBlanc, A. D.; Putcha, L.; Whitson, P. A.

    1993-01-01

    Space flight provides a model for the study of healthy individuals undergoing unique stresses. This review focuses on how physiological adaptations to weightlessness may affect nutrient and food requirements in space. These adaptations include reductions in body water and plasma volume, which affect the renal and cardiovascular systems and thereby fluid and electrolyte requirements. Changes in muscle mass and function may affect requirements for energy, protein and amino acids. Changes in bone mass lead to increased urinary calcium concentrations, which may increase the risk of forming renal stones. Space motion sickness may influence putative changes in gastro-intestinal-hepatic function; neurosensory alterations may affect smell and taste. Some or all of these effects may be ameliorated through the use of specially designed dietary countermeasures.

  2. Fever and sickness behavior: Friend or foe?

    Science.gov (United States)

    Harden, L M; Kent, S; Pittman, Q J; Roth, J

    2015-11-01

    Fever has been recognized as an important symptom of disease since ancient times. For many years, fever was treated as a putative life-threatening phenomenon. More recently, it has been recognized as an important part of the body's defense mechanisms; indeed at times it has even been used as a therapeutic agent. The knowledge of the functional role of the central nervous system in the genesis of fever has greatly improved over the last decade. It is clear that the febrile process, which develops in the sick individual, is just one of many brain-controlled sickness symptoms. Not only will the sick individual appear "feverish" but they may also display a range of behavioral changes, such as anorexia, fatigue, loss of interest in usual daily activities, social withdrawal, listlessness or malaise, hyperalgesia, sleep disturbances and cognitive dysfunction, collectively termed "sickness behavior". In this review we consider the issue of whether fever and sickness behaviors are friend or foe during: a critical illness, the common cold or influenza, in pregnancy and in the newborn. Deciding whether these sickness responses are beneficial or harmful will very much shape our approach to the use of antipyretics during illness. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Relative Deprivation and Sickness Absence in Sweden

    Directory of Open Access Journals (Sweden)

    Jonas Helgertz

    2013-08-01

    Full Text Available Background: A high prevalence of sickness absence in many countries, at a substantial societal cost, underlines the importance to understand its determining mechanisms. This study focuses on the link between relative deprivation and the probability of sickness absence. Methods: 184,000 men and women in Sweden were followed between 1982 and 2001. The sample consists of working individuals between the ages of 19 and 65. The outcome is defined as experiencing more than 14 days of sickness absence during a year. Based on the complete Swedish population, an individual’s degree of relative deprivation is measured through income compared to individuals of the same age, sex, educational level and type. In accounting for the possibility that sickness absence and socioeconomic status are determined by common factors, discrete-time duration models were estimated, accounting for unobserved heterogeneity through random effects. Results: The results confirm that the failure to account for the dynamics of the individual’s career biases the influence from socioeconomic characteristics. Results consistently suggest a major influence from relative deprivation, with a consistently lower risk of sickness absence among the highly educated. Conclusions: Altering individual’s health behavior through education appears more efficient in reducing the reliance on sickness absence, rather than redistributive policies.

  4. Relative deprivation and sickness absence in Sweden.

    Science.gov (United States)

    Helgertz, Jonas; Hess, Wolfgang; Scott, Kirk

    2013-08-29

    A high prevalence of sickness absence in many countries, at a substantial societal cost, underlines the importance to understand its determining mechanisms. This study focuses on the link between relative deprivation and the probability of sickness absence. 184,000 men and women in Sweden were followed between 1982 and 2001. The sample consists of working individuals between the ages of 19 and 65. The outcome is defined as experiencing more than 14 days of sickness absence during a year. Based on the complete Swedish population, an individual's degree of relative deprivation is measured through income compared to individuals of the same age, sex, educational level and type. In accounting for the possibility that sickness absence and socioeconomic status are determined by common factors, discrete-time duration models were estimated, accounting for unobserved heterogeneity through random effects. The results confirm that the failure to account for the dynamics of the individual's career biases the influence from socioeconomic characteristics. Results consistently suggest a major influence from relative deprivation, with a consistently lower risk of sickness absence among the highly educated. Altering individual's health behavior through education appears more efficient in reducing the reliance on sickness absence, rather than redistributive policies.

  5. Prognosis for a sick planet.

    Science.gov (United States)

    Maslin, Mark

    2008-12-01

    Global warming is the most important science issue of the 21st century, challenging the very structure of our global society. The study of past climate has shown that the current global climate system is extremely sensitive to human-induced climate change. The burning of fossil fuels since the beginning of the industrial revolution has already caused changes with clear evidence for a 0.75 degrees C rise in global temperatures and 22 cm rise in sea level during the 20th century. The Intergovernmental Panel on Climate Change synthesis report (2007) predicts that global temperatures by 2100 could rise by between 1.1 degrees C and 6.4 degrees C. Sea level could rise by between 28 cm and 79 cm, more if the melting of the polar ice caps accelerates. In addition, weather patterns will become less predictable and the occurrence of extreme climate events, such as storms, floods, heat waves and droughts, will increase. The potential effects of global warming on human society are devastating. We do, however, already have many of the technological solutions to cure our sick planet.

  6. [Subjective sensations indicating simulator sickness and fatigue after exposure to virtual reality].

    Science.gov (United States)

    Malińska, Marzena; Zuzewicz, Krystyna; Bugajska, Joanna; Grabowski, Andrzej

    2014-01-01

    The study assessed the incidence and intensity of subjective symptoms indicating simulator sickness among the persons with no inclination to motion sickness, immersed in virtual reality (VR) by watching an hour long movie in the stereoscopic (three-dimensional - 3D) and non-stereoscopic (two-dimensional - 2D) versions and after an hour long training using virtual reality, called sVR. The sample comprised 20 healthy young men with no inclination to motion sickness. The participants' subjective sensations, indicating symptoms of simulator sickness were assessed using the questionnaire completed by the participants immediately, 20 min and 24 h following the test. Grandjean's scale was used to assess fatigue and mood. The symptoms were observed immediately after the exposure to sVR. Their intensity was higher than after watching the 2D and 3D movies. A significant relationship was found between the eye pain and the type of exposure (2D, 3D and sVR) (Chi2)(2) = 6.225, p < or = 0.05); the relationship between excessive perspiration and the exposure to 31) movie and sVR was also noted (Chi2(1) = 9.173, p < or = 0.01). Some symptoms were still observed 20 min after exposure to sVR. The comparison of Grandjean's scale results before and after the training in sVR handing showed significant differences in 11 out of 14 subscales. Before and after exposure to 3D movie, the differences were significant only for the "tired-fatigued" subscale (Z = 2.501, p < or = 0.012) in favor of "fatigued". Based on the subjective sensation of discomfort after watching 2D and 3D movies it is impossible to predict symptoms of simulator sickness after training using sVR.

  7. Symmetries and conserved quantities in geodesic motion

    International Nuclear Information System (INIS)

    Hojman, S.; Nunez, L.; Patino, A.; Rago, H.

    1986-01-01

    Recently obtained results linking several constants of motion to one (non-Noetherian) symmetry to the problem of geodesic motion in Riemannian space-times are applied. The construction of conserved quantities in geodesic motion as well as the deduction of geometrical statements about Riemannian space-times are achieved

  8. Sick but yet at work. An empirical study of sickness presenteeism.

    Science.gov (United States)

    Aronsson, G; Gustafsson, K; Dallner, M

    2000-07-01

    The study is an empirical investigation of sickness presenteeism in relation to occupation, irreplaceability, ill health, sickness absenteeism, personal income, and slimmed down organisation. Cross sectional design. Swedish workforce. The study group comprised a stratified subsample of 3801 employed persons working at the time of the survey, interviewed by telephone in conjunction with Statistics Sweden's labour market surveys of August and September 1997. The response rate was 87 per cent. A third of the persons in the total material reported that they had gone to work two or more times during the preceding year despite the feeling that, in the light of their perceived state of health, they should have taken sick leave. The highest presenteeism is largely to be found in the care and welfare and education sectors (nursing and midwifery professionals, registered nurses, nursing home aides, compulsory school teachers and preschool/primary educationalists. All these groups work in sectors that have faced personnel cutbacks during the 1990s). The risk ratio (odds ratio (OR)) for sickness presenteeism in the group that has to re-do work remaining after a period of absence through sickness is 2.29 (95% CI 1.79, 2.93). High proportions of persons with upper back/neck pain and fatigue/slightly depressed are among those with high presenteeism (pwork when sick. The link between difficulties in replacement or finding a stand in and sickness presenteeism is confirmed by study results. The categories with high sickness presenteeism experience symptoms more often than those without presenteeism. The most common combination is low monthly income, high sickness absenteeism and high sickness presenteeism.

  9. Changes in sickness absenteeism following the introduction of a qualifying day for sickness benefit--findings from Sweden Post

    DEFF Research Database (Denmark)

    Voss, M; Floderus, B; Diderichsen, F

    2001-01-01

    AIMS: In 1993, a qualifying day without sickness benefit was introduced to the Swedish sickness benefit system. The aim of the present study is to investigate sickness absenteeism before and after the introduction of the qualifying day, in the light of conditions inside and outside working life....... METHODS: The study was based on 1,952 female and 2,229 male employees of Sweden Post. Sickness absence was measured by sickness incidence one year before and one year after the introduction of the qualifying day (sick-leave events/person days at risk). Information about explanatory factors was collected...

  10. Attitudes towards sickness absence and sickness presenteeism in health and care sectors in Norway and Denmark: a qualitative study.

    Science.gov (United States)

    Krane, Line; Larsen, Eva Ladekjær; Nielsen, Claus Vinther; Stapelfeldt, Christina Malmose; Johnsen, Roar; Risør, Mette Bech

    2014-08-27

    In the health and care sector, sickness absence and sickness presenteeism are frequent phenomena and constitute a field in need of exploration. Attitudes towards sickness absence involve also attitudes towards sickness presenteeism, i.e. going to work while sick, confirmed by previous studies. Sickness behavior, reflecting attitudes on work absence, could differ between countries and influence absence rates. But little is known about attitudes towards sickness absence and sickness presenteeism in the health and care sectors in Norway and Denmark. The aim of the present paper is therefore to explore attitudes towards sickness absence and sickness presenteeism among nursing home employees in both countries. Eight focus group discussions (FGDs) were conducted using a semi-structured interview guide, the main attention of which was attitudes towards sickness absence and sickness presenteeism. FGDs were conducted in two nursing homes in Norway and two in Denmark, with different geographic locations: one in a rural area and one in an urban area in each country. FGDs were recorded, transcribed and analyzed using framework analysis to identify major themes and explanatory patterns. Four major significant themes were identified from the FGDs: a) sickness absence and sickness presenteeism, b) acceptable causes of sickness absence, c) job identity, and d) organization of work and physical aspects of the workplace. Our analyses showed that social commitment and loyalty to residents and colleagues was important for sickness absence and sickness presenteeism, as were perceived acceptable and non-acceptable reasons for sickness absence. Organization of work and physical aspects of the workplace were also found to have an influence on attitudes towards sickness absence. The general interpretation of the findings was that attitudes towards sickness absence and sickness presenteeism among nursing home employees were embedded in situational patterns of moral relationships and were

  11. Validation of sick leave measures: self-reported sick leave and sickness benefit data from a Danish national register compared to multiple workplace-registered sick leave spells in a Danish municipality.

    Science.gov (United States)

    Stapelfeldt, Christina Malmose; Jensen, Chris; Andersen, Niels Trolle; Fleten, Nils; Nielsen, Claus Vinther

    2012-08-15

    Previous validation studies of sick leave measures have focused on self-reports. Register-based sick leave data are considered to be valid; however methodological problems may be associated with such data. A Danish national register on sickness benefit (DREAM) has been widely used in sick leave research. On the basis of sick leave records from 3,554 and 2,311 eldercare workers in 14 different workplaces, the aim of this study was to: 1) validate registered sickness benefit data from DREAM against workplace-registered sick leave spells of at least 15 days; 2) validate self-reported sick leave days during one year against workplace-registered sick leave. Agreement between workplace-registered sick leave and DREAM-registered sickness benefit was reported as sensitivities, specificities and positive predictive values. A receiver-operating characteristic curve and a Bland-Altman plot were used to study the concordance with sick leave duration of the first spell. By means of an analysis of agreement between self-reported and workplace-registered sick leave sensitivity and specificity was calculated. Ninety-five percent confidence intervals (95% CI) were used. The probability that registered DREAM data on sickness benefit agrees with workplace-registered sick leave of at least 15 days was 96.7% (95% CI: 95.6-97.6). Specificity was close to 100% (95% CI: 98.3-100). The registered DREAM data on sickness benefit overestimated the duration of sick leave spells by an average of 1.4 (SD: 3.9) weeks. Separate analysis on pregnancy-related sick leave revealed a maximum sensitivity of 20% (95% CI: 4.3-48.1).The sensitivity of self-reporting at least one or at least 56 sick leave day/s was 94.5 (95% CI: 93.4 - 95.5) % and 58.5 (95% CI: 51.1 - 65.6) % respectively. The corresponding specificities were 85.3 (95% CI: 81.4 - 88.6) % and 98.9 (95% CI: 98.3 - 99.3) %. The DREAM register offered valid measures of sick leave spells of at least 15 days among eldercare employees. Pregnancy

  12. Validation of sick leave measures: self-reported sick leave and sickness benefit data from a Danish national register compared to multiple workplace-registered sick leave spells in a Danish municipality

    Directory of Open Access Journals (Sweden)

    Stapelfeldt Christina Malmose

    2012-08-01

    Full Text Available Abstract Background Previous validation studies of sick leave measures have focused on self-reports. Register-based sick leave data are considered to be valid; however methodological problems may be associated with such data. A Danish national register on sickness benefit (DREAM has been widely used in sick leave research. On the basis of sick leave records from 3,554 and 2,311 eldercare workers in 14 different workplaces, the aim of this study was to: 1 validate registered sickness benefit data from DREAM against workplace-registered sick leave spells of at least 15 days; 2 validate self-reported sick leave days during one year against workplace-registered sick leave. Methods Agreement between workplace-registered sick leave and DREAM-registered sickness benefit was reported as sensitivities, specificities and positive predictive values. A receiver-operating characteristic curve and a Bland-Altman plot were used to study the concordance with sick leave duration of the first spell. By means of an analysis of agreement between self-reported and workplace-registered sick leave sensitivity and specificity was calculated. Ninety-five percent confidence intervals (95% CI were used. Results The probability that registered DREAM data on sickness benefit agrees with workplace-registered sick leave of at least 15 days was 96.7% (95% CI: 95.6-97.6. Specificity was close to 100% (95% CI: 98.3-100. The registered DREAM data on sickness benefit overestimated the duration of sick leave spells by an average of 1.4 (SD: 3.9 weeks. Separate analysis on pregnancy-related sick leave revealed a maximum sensitivity of 20% (95% CI: 4.3-48.1. The sensitivity of self-reporting at least one or at least 56 sick leave day/s was 94.5 (95% CI: 93.4 – 95.5 % and 58.5 (95% CI: 51.1 – 65.6 % respectively. The corresponding specificities were 85.3 (95% CI: 81.4 – 88.6 % and 98.9 (95% CI: 98.3 – 99.3 %. Conclusions The DREAM register offered valid measures of sick

  13. The Impact of Motion Induced Interruptions on Cognitive Performance

    Science.gov (United States)

    2014-07-23

    found that even participants presenting with minor physiological effects of motion experienced a decline in multitasking performance. Further, Yu...literature has investigated the impact of task based interruptions such as being inter- rupted by a phone call or writing an email . In these...Engineers Journal. 102 (2) 65-72. Matsangas, P. (2013). The Effect of Mild Motion Sickness and Sopite Syndrome on Multitasking Cognitive Performance

  14. Occupational exposures and sick leave during pregnancy

    DEFF Research Database (Denmark)

    Hansen, Mette Lausten; Thulstrup, Ane Marie; Juhl, Mette

    2015-01-01

    OBJECTIVE: This study aimed to investigate associations between work postures, lifting at work, shift work, work hours, and job strain and the risk of sick leave during pregnancy from 10-29 completed pregnancy weeks in a large cohort of Danish pregnant women. METHODS: Data from 51 874 pregnancies...... in the Danish National Birth Cohort collected between 1996-2002 were linked to the Danish Register for Evaluation of Marginalization. Exposure information was based on telephone interviews. Hazard ratios (HR) with 95% confidence intervals (95% CI) were calculated by Cox regression analysis, using time of first...... episode of sick leave as the primary outcome. RESULTS: We found statistically significant associations between all the predictors and risk of sick leave; for non-sitting work postures (HRrange 1.55-2.79), cumulative lifting HRtrend 1.29, 95% CI 1.26-1.31, shift work (HRevening 1.90, 95% CI 1...

  15. Study of prochlorperazine (Stemetil) in radiation sickness

    International Nuclear Information System (INIS)

    Dutta, A.K.

    1976-01-01

    The incidence of radiation sickness and the efficacy of prochlorperazine in alleviating it among the patients under radiotherapy have been investigated. 116 patients from those under radiotherapy were randomly chosen. 38% of this sample developed radiation sickness symptoms (nausea and vomiting). The onset of symptoms occurred in the earlier periods of radiotherapy. The younger and older group were more susceptible to side effects of radiation. Prochlorperazine was administered immediately after the onset of symptoms of radiation sickness in the dose schedule of 10 mg twice daily for adults and was continued for 5 to 10 days after the alleviation of the symptoms. This was found to be effective in all patients. (M.G.B.)

  16. Sleeping sickness surveys: game reserve adjacent villages in Malawi

    African Journals Online (AJOL)

    Sleeping sickness surveys: game reserve adjacent villages in Malawi. ... Sera from 160 game ranger volunteers and from 82 suspected cases_of Rhodesian sleeping sickness were tested by use of ELISA, ... AJOL African Journals Online.

  17. How to avoid simulation sickness in virtual environments during user displacement

    Science.gov (United States)

    Kemeny, A.; Colombet, F.; Denoual, T.

    2015-03-01

    Driving simulation (DS) and Virtual Reality (VR) share the same technologies for visualization and 3D vision and may use the same technics for head movement tracking. They experience also similar difficulties when rendering the displacements of the observer in virtual environments, especially when these displacements are carried out using driver commands, including steering wheels, joysticks and nomad devices. High values for transport delay, the time lag between the action and the corresponding rendering cues and/or visual-vestibular conflict, due to the discrepancies perceived by the human visual and vestibular systems when driving or displacing using a control device, induces the so-called simulation sickness. While the visual transport delay can be efficiently reduced using high frequency frame rate, the visual-vestibular conflict is inherent to VR, when not using motion platforms. In order to study the impact of displacements on simulation sickness, we have tested various driving scenarios in Renault's 5-sided ultra-high resolution CAVE. First results indicate that low speed displacements with longitudinal and lateral accelerations under a given perception thresholds are well accepted by a large number of users and relatively high values are only accepted by experienced users and induce VR induced symptoms and effects (VRISE) for novice users, with a worst case scenario corresponding to rotational displacements. These results will be used for optimization technics at Arts et Métiers ParisTech for motion sickness reduction in virtual environments for industrial, research, educational or gaming applications.

  18. Trends in sickness absence in Denmark

    DEFF Research Database (Denmark)

    Johansen, Kristina; Bihrmann, Kristine; Mikkelsen, Sigurd

    2009-01-01

    's Authority, and the Labor Force Survey indicated a stable and largely unaltered pattern of sickness absence during the last 20 years. Findings from Statistics Denmark showed an increase in the cumulative incidence proportion from 6.6 to 7.5% among employed people between 2000 and 2007. CONCLUSION: Our data...... a linear regression analysis to analyze time trends in sickness absence based on datasets from the Danish Employers Confederation, the State Employer's Authority, the Labour Force Survey, and Statistics Denmark. RESULTS: The findings from the Confederation of Danish Employers, the State Employer...

  19. Does paternity leave affect mothers’ sickness absence

    OpenAIRE

    Bratberg, Espen; Naz, Ghazala

    2009-01-01

    Female labour force participation is high in Norway but sickness absence rates are higher for women than for men. This may be partly a result of unequal sharing of childcare in the family. In this paper, we consider the effect of paternity leave on sickness absence among women who have recently given birth. We draw on a six-year panel taken from full population data from administrative sources. We find that in the 6% of families where fathers take out leave more than the standard quota (gende...

  20. Is part-time sick leave helping the unemployed?

    OpenAIRE

    Andrén, Daniela

    2011-01-01

    Using a discrete choice one-factor model, we estimate mean treatment parameters and distributional treatment parameters to analyze the effects of degree of sick leave on the probability of full recovery of lost work capacity for employed and unemployed individuals, respectively. Our results indicate that one year after the sick leave spell started, the average potential impact of part-time sick listing on an individual randomly chosen from the population on sick leave was positive for both gr...

  1. CNA-motion in a PS - Fn

    International Nuclear Information System (INIS)

    Singh, M.P.; Mishra, C.K.

    1989-12-01

    A Finsler space Fn (n > 2), throughout with the projective curvature tensor possessing vanishing covariant derivative, has been called a ''projectively symmetric Finsler space'' and such a space is denoted PS-Fn. The conditions in which an infinitesimal transformation defines non-affine motion with a contra-field, briefly called CNA-motion, are discussed. 7 refs

  2. Determinants of sick-leave duration : A tool for managers?

    NARCIS (Netherlands)

    Flach, P.A.; Krol, B.; Groothoff, J.W.

    AIMS: To provide managers with tools to manage episodes of sick-leave of their employees, the influence of factors such as age, gender, duration of tenure, working full-time or part-time, cause and history of sick-leave, salary and education on sick-leave duration was studied. METHOD: In a

  3. How Safe Is Measles Immunization Of Sick Children? | Ogbonna ...

    African Journals Online (AJOL)

    A prospective study to ascertain how safe is maeales immunization of sick children was carried out in Jos University Teaching Hospital, Family Health Centre. Out of 125 children who were vaccinated against measles 17(16%) were sick at the time of vaccination. Two (12%) of the sick children had post vaccination reaction.

  4. Reliability of sickness certificates in detecting potential sick leave reduction by modifying working conditions: a clinical epidemiology study

    Directory of Open Access Journals (Sweden)

    Johnsen Roar

    2004-03-01

    Full Text Available Abstract Background Medical sickness certificates are generally the main source for information when scrutinizing the need for aimed intervention strategies to avoid or reduce the individual and community side effects of sick leave. This study explored the value of medical sickness certificates related to daily work in Norwegian National Insurance Offices to identify sick-listed persons, where modified working conditions might reduce the ongoing sick leave. Methods The potential for reducing the ongoing sick leave by modifying working conditions was individually assessed on routine sickness certificates in 999 consecutive sick leave episodes by four Norwegian National Insurance collaborators, two with and two without formal medical competence. The study took place in Northern Norway in 1997 and 1998. Agreement analysed with differences against mean, kappa, and proportional-agreement analysis within and between groups of assessors was used in the judgement. Agreements between the assessors and the self-assessment of sick-listed subjects were additionally analysed in 159 sick-leave episodes. Results Both sick-listed subjects and National Insurance collaborators anticipated a potential reduction in sick leave in 20–30% of cases, and in another 20% the potential was assessed as possible. The chance corrected agreements, however, were poor (k Conclusion Information in medical sickness certificates proved ineffective in detecting cases where modified working conditions may reduce sick leave, and focusing on medical certificates may prevent identification of needed interventions. Strategies on how to communicate directly with sick-listed subjects would enable social authorities to exploit more of the sick leave reduction potential by modifying the working conditions than strategies on improving medical information.

  5. Circadian-Time Sickness: Time-of-Day Cue-Conflicts Directly Affect Health.

    Science.gov (United States)

    van Ee, Raymond; Van de Cruys, Sander; Schlangen, Luc J M; Vlaskamp, Björn N S

    2016-11-01

    A daily rhythm that is not in synchrony with the environmental light-dark cycle (as in jetlag and shift work) is known to affect mood and health through an as yet unresolved neural mechanism. Here, we combine Bayesian probabilistic 'cue-conflict' theory with known physiology of the biological clock of the brain, entailing the insight that, for a functional pacemaker, it is sufficient to have two interacting units (reflecting environmental and internal time-of-day cues), without the need for an extra homuncular directing unit. Unnatural light-dark cycles cause a time-of-day cue-conflict that is reflected by a desynchronization between the ventral (environmental) and dorsal (internal) pacemaking signals of the pacemaker. We argue that this desynchronization, in-and-of-itself, produces health issues that we designate as 'circadian-time sickness', analogous to 'motion sickness'. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Cerebral blood flow in acute mountain sickness

    DEFF Research Database (Denmark)

    Jensen, J B; Wright, Anne; Lassen, N A

    1990-01-01

    Changes in cerebral blood flow (CBF) were measured using the radioactive xenon technique and were related to the development of acute mountain sickness (AMS). In 12 subjects, ascending from 150 to 3,475 m, CBF was 24% increased at 24 h [45.1 to 55.9 initial slope index (ISI) units] and 4% increased...

  7. [The sick individual as a concept].

    Science.gov (United States)

    Tejerizo López, Luis Carlos

    2011-01-01

    We start from the premise, shared by some current philosophical movements and by the author, which states that philosophy is not contemplation, or reflection, or introspection or communication. Philosophy is the art of shaping, inventing and creating concepts. It is an explicit way of introducing new differences in life, a different reading level, a specific jargon, which may imply revealing the flip side of the coin, or a dissimilar view of the side facing us. The philosopher is the friend of the concept, he holds it in his power, which means, basically and in all honesty, that philosophy is the discipline of creating concepts. Let us remember the brilliant idea of the Russian director Tarkovsky, who announced his greatest ambition as an artist: "To capture time". At the same time, we must recall one of the sayings of this director: "Every film I have directed and I intend to direct is always tied to characters who have something to overcome". The healthy individual lives in a specific time, with precise coordinates, aware that his life consists only of living that time. That is, living as defined by Josep María Esquirol: "Then we could also see that the best way of living the present is not to run after the fleeing time, but to see and live the opportunity that appears before us". One of the many circumstances that can intercept the way we see and live the opportunity that appears before us is sickness, one of those inescapable experiences we have not been taught how to pay an adequate attention to, and the meaning of which can, in a way, go unnoticed. As "time" goes by, the circumstance that we consider to be the basis on which existence is founded, sickness can appear, thus introducing a new dimension in the time of the healthy individual. For this reason we, as doctors and professionals, know that sickness "is tied to characters who have something to overcome". In view of the fact that a sickness invades a healthy individual and transforms him into a sick one

  8. Sick Leave and Factors Influencing Sick Leave in Adult Patients with Atopic Dermatitis : A Cross-Sectional Study

    NARCIS (Netherlands)

    van Os-Medendorp, Harmieke; Appelman-Noordermeer, Simone; Bruijnzeel-Koomen, Carla A.F.M.; de Bruin-Weller, MS

    2015-01-01

    BACKGROUND: Little is known about the prevalence of sick leave due to atopic dermatitis (AD). The current literature on factors influencing sick leave is mostly derived from other chronic inflammatory diseases. This study aimed to determine the prevalence of sick leave due to AD and to identify

  9. Modification of Time-dependent Schrodinger Equation in Quantum Mechanics by Adding Derivations of Time's Flow (Relative Time) with Respect of the Both Space and Time Based on the ``Substantial Motion'' Theory of Iranian Philosopher; Mulla Sadra

    Science.gov (United States)

    Gholibeigian, Hassan; Gholibeigian, Kazem

    2016-03-01

    In Sadra's theory, the relative time for an atom (body) which is varying continuously becomes momentums of its involved fundamental particles (strings), (time's relativity) [Gholibeigian, APS March Meeting 2015, abstract #V1.023]. Einstein's theory of special relativity might be special form of Sadra's theory. ``The nature has two magnitudes and two elongations, the one is gradual being (wavy-like motion) which belongs to the time and dividable to the former and the next times in mind, and the other is jerky-like motion which belongs to the space and dividable to the former and the next places'' [Asfar, Mulla Sadra, (1571/2-1640)]. Sadra separated the nature of time from nature of space. Therefore we can match these two natures on wave-particle duality. It means that the nature of time might be wavy-like and the nature of space might be jerky-like. So, there are two independent variable sources for particle(s)' flow with respect of its two natures such as potential of flow and relative time which vary with respect of both space and time. Consequently we propose two additional parts to Schrodinger's equation: H⌢ Ψ +tp ∇t' = ih/2 π ∂/∂t Ψ +tp∂/∂t t' , where tp is Planck's time and t' is relative time: t' = f (m , v , t) = t +/- Δt , in which t is time, m is mass and vis speed of particle . AmirKabir University of Technology, Tehran, Iran.

  10. Modification of Schrodinger Equation in Quantum Mechanics by Adding Derivations of Time's Flow (Relative Time) with Respect of the Both Space and Time Based on the ``Substantial Motion'' Theory of Iranian Philosopher; Mulla Sadra

    Science.gov (United States)

    Gholibeigian, Hassan; Amirshahkarami, Abdolazim; Gholibeigian, Kazem

    2016-05-01

    ``The nature has two magnitudes and two elongations, one is gradual being (wavy-like motion) which belongs to the time and dividable to the former and the next times in mind, and the other one is jerky-like motion which belongs to the space and dividable to the former and the next places'' [Asfar, Mulla Sadra, (1571/2-1640)]. These two separated natures of space-time are matched on wave-particle duality. Therefore, the nature of time can be wavy-like and the nature of space can be jerky-like. So, there are two independent variable sources of particle(s)' flow while they are match exactly with each other. These two sources are potential of flow and potential of time (relative time) which vary with respect to both space and time. Here, we propose two additional parts to Schrodinger's equation with respect to relative time: HΨ + ∇t' = EΨ + ∂t' / ∂t , where t is time and t' is relative time: t' = t +/- Δt [Gholibeigian et al., APS March Meeting 2016], which for each atom becomes: tatom = ∑mnucleons + ∑melectrons where m is momentum [Gholibeigian, APS March Meeting 2015, abstract #V1.023]. Using time's relativity in Schrodinger equation will give us more precious results. AmirKabir University of Technology,Tehran, Iran.

  11. Part-Time Sick Leave as a Treatment Method?

    OpenAIRE

    Andrén D; Andrén T

    2009-01-01

    This paper analyzes the effects of being on part-time sick leave compared to full-time sick leave on the probability of recovering (i.e., returning to work with full recovery of lost work capacity). Using a discrete choice one-factor model, we estimate mean treatment parameters and distributional treatment parameters from a common set of structural parameters. Our results show that part-time sick leave increases the likelihood of recovering and dominates full-time sick leave for sickness spel...

  12. Predicting articulated human motion from spatial processes

    DEFF Research Database (Denmark)

    Hauberg, Søren; Pedersen, Kim Steenstrup

    2011-01-01

    recent work where prior models are derived in terms of joint angles. This approach has several advantages. First of all, it allows us to construct motion models in low dimensional spaces, which makes motion estimation more robust. Secondly, as many types of motion are easily expressed in spatial...

  13. Influenza in workplaces: transmission, workers' adherence to sick leave advice and European sick leave recommendations.

    Science.gov (United States)

    Edwards, Christina Hansen; Tomba, Gianpaolo Scalia; de Blasio, Birgitte Freiesleben

    2016-06-01

    Knowledge about influenza transmission in the workplace and whether staying home from work when experiencing influenza-like illness can reduce the spread of influenza is crucial for the design of efficient public health initiatives. This review synthesizes current literature on sickness presenteeism and influenza transmission in the workplace and provides an overview of sick leave recommendations in Europe for influenza. A search was performed on Medline, Embase, PsychINFO, Cinahl, Web of Science, Scopus and SweMed to identify studies related to workplace contacts, -transmission, -interventions and compliance with recommendations to take sick leave. A web-based survey on national recommendations and policies for sick leave during influenza was issued to 31 European countries. Twenty-two articles (9 surveys; 13 modelling articles) were eligible for this review. Results from social mixing studies suggest that 20-25% of weekly contacts are made in the workplace, while modelling studies suggest that on average 16% (range 9-33%) of influenza transmission occurs in the workplace. The effectiveness of interventions to reduce workplace presenteeism is largely unknown. Finally, estimates from studies reporting expected compliance with sick leave recommendations ranged from 71 to 95%. Overall, 18 countries participated in the survey of which nine (50%) had issued recommendations encouraging sick employees to stay at home during the 2009 A(H1N1) pandemic, while only one country had official recommendations for seasonal influenza. During the 2009 A(H1N1) pandemic, many European countries recommended ill employees to take sick leave. Further research is warranted to quantify the effect of reduced presenteeism during influenza illness. © The Author 2016. Published by Oxford University Press on behalf of the European Public Health Association.

  14. Influenza in workplaces: transmission, workers’ adherence to sick leave advice and European sick leave recommendations

    Science.gov (United States)

    Tomba, Gianpaolo Scalia; de Blasio, Birgitte Freiesleben

    2016-01-01

    Background: Knowledge about influenza transmission in the workplace and whether staying home from work when experiencing influenza-like illness can reduce the spread of influenza is crucial for the design of efficient public health initiatives. Aim: This review synthesizes current literature on sickness presenteeism and influenza transmission in the workplace and provides an overview of sick leave recommendations in Europe for influenza. Methods: A search was performed on Medline, Embase, PsychINFO, Cinahl, Web of Science, Scopus and SweMed to identify studies related to workplace contacts, -transmission, -interventions and compliance with recommendations to take sick leave. A web-based survey on national recommendations and policies for sick leave during influenza was issued to 31 European countries. Results: Twenty-two articles (9 surveys; 13 modelling articles) were eligible for this review. Results from social mixing studies suggest that 20–25% of weekly contacts are made in the workplace, while modelling studies suggest that on average 16% (range 9–33%) of influenza transmission occurs in the workplace. The effectiveness of interventions to reduce workplace presenteeism is largely unknown. Finally, estimates from studies reporting expected compliance with sick leave recommendations ranged from 71 to 95%. Overall, 18 countries participated in the survey of which nine (50%) had issued recommendations encouraging sick employees to stay at home during the 2009 A(H1N1) pandemic, while only one country had official recommendations for seasonal influenza. Conclusions: During the 2009 A(H1N1) pandemic, many European countries recommended ill employees to take sick leave. Further research is warranted to quantify the effect of reduced presenteeism during influenza illness. PMID:27060594

  15. Space Medicine: Shuttle - Space Station Crew Health and Safety Challenges for Exploration

    Science.gov (United States)

    Dervay, Joseph

    2010-01-01

    This slide presentation combines some views of the shuttle take off, and the shuttle and space station on orbit, and some views of the underwater astronaut training , with a general discussion of Space Medicine. It begins with a discussion of the some of the physiological issues of space flight. These include: Space Motion Sickness (SMS), Cardiovascular, Neurovestibular, Musculoskeletal, and Behavioral/Psycho-social. There is also discussion of the space environment and the issues that are posed including: Radiation, Toxic products and propellants, Habitability, Atmosphere, and Medical events. Included also is a discussion of the systems and crew training. There are also artists views of the Constellation vehicles, the planned lunar base, and extended lunar settlement. There are also slides showing the size of earth in perspective to the other planets, and the sun and the sun in perspective to other stars. There is also a discussion of the in-flight changes that occur in neural feedback that produces postural imbalance and loss of coordination after return.

  16. Diagnosis of moderate acute radiation sickness

    International Nuclear Information System (INIS)

    Yu Shoucheng; Chen Zhijian; Chen Youxin

    1989-01-01

    Forty patients with malignant lymphoma were given 60 Co TLI. 21 cases received 6 Gy and 19 received 8 Gy. It was estimated that a single TLI of 6 and 8 Gy would correspond to TBI of 3.55 Gy and 4.25 Gy (average values) by analysing peripheral blood cell chromosome aberrations and 1.85-2.37 Gy by measuring red bone marrow stem cells clinically. Moderate acute radiation sickness with digestive tract reaction and hemopoietic and immunologic depression was observed. WBC and platelets decreased rapidly. Lymphocytes showed quantitative and qualitative changes even at early stage. All these indexes are significant for diagnosis. Besides, the degree of labial stimulation response, levels of C-reactive protein, corticoid, and urinal nucleoside and alkaloid base presented great changes both pre-and post-irradiation. Early diagnosis of moderate acute radiation sickness could be made in cancer patients subjected to 6-8 Gy TLI

  17. Sickness absence and sickness attendance--what people with neck or back pain think.

    Science.gov (United States)

    Hansson, Margareta; Boström, Carina; Harms-Ringdahl, Karin

    2006-05-01

    This study explores the decision of 33 men and women to be sick-listed from work for neck pain or low-back pain. Qualitative interviews with the subjects, who lived in a city or a sparsely populated area of Sweden, were tape-recorded, transcribed and analysed in the interpretive tradition by the three authors. New, intense and threatening pain quickly made persons report sick. For other pain, sickness absence, its timing and duration, were negotiated on the basis of the subjects' self-image, work-duty norms, organisational and extra-organisational work factors. Thirty-one people aimed to return to work, but spine-related pain was a hindrance. Five strategies to avoid, delay or shorten sickness absence were identified. Concepts of the illness flexibility model well described how the workers balanced the factors driving them from work and those forcing them or attracting them to remain. The conclusion is that reporting sick is neither undertaken lightly nor for short-term reasons only. Instead, personal history and anticipated future, spine-related pain, workplace and labour market factors are also important considerations.

  18. Prediction of sickness absenteeism, disability pension and sickness presenteeism among employees with back pain.

    Science.gov (United States)

    Bergström, Gunnar; Hagberg, Jan; Busch, Hillevi; Jensen, Irene; Björklund, Christina

    2014-06-01

    The primary aim of this study was to evaluate the predictive ability of the Örebro Musculoskeletal Pain Screening Questionnaire (ÖMPSQ) concerning long-term sick leave, sickness presenteeism and disability pension during a follow-up period of 2 years. The study group consisted of 195 employees visiting the occupational health service (OHS) due to back pain. Using receiver operating characteristic (ROC) curves, the area under the curve (AUC) varied from 0.67 to 0.93, which was from less accurate for sickness presenteeism to highly accurate for the prediction of disability pension. For registered sick leave during 6 months following the baseline the AUC from the ROC analyses was moderately accurate (0.81) and a cut off score of 90 rendered a high sensitivity of 0.89 but a low specificity of 0.46 whereas a cut off score of 105 improves the specificity substantially but at the cost of some sensitivity. The predictive ability appears to decrease with time. Several workplace factors beyond those included in the ÖMPSQ were considered but only social support at the workplace was significantly related to future long-term sick leave besides the total score of the ÖMPSQ. The results of this study extend and confirm the findings of earlier research on the ÖMPSQ. Assessment of psychosocial risk factors among employees seeking help for back pain at the OHS could be helpful in the prevention of work disabling problems.

  19. The Negotiation of the Sick Role

    DEFF Research Database (Denmark)

    Mik-Meyer, Nanna; Roelsgaard Obling, Anne

    2012-01-01

    ’s particular circumstances in deciding whether that patient is legitimately sick. The doctor is thus a gatekeeper of legitimacy. This article presents results from a qualitative interview study conducted in Denmark with GPs concerning their approach to patients with MUS. We employ a symbolic interaction...... to which GPs are able to constitute these patients as people with social problems and problematic personality traits....

  20. Absenteeism due to sickness in coal miners

    Energy Technology Data Exchange (ETDEWEB)

    Szymczykiewicz, K.

    1980-01-01

    During two consecutive years sickness absence of 8005 miners from two pit coal mines (A and B) of different geological structure and mechanization degree was analysed. It was found that in mine ''A'' 37% had no sick leaves, whereas in mine ''B''--28%. Absence rate was similar in both mines (though the miners' work and living conditions differed), i.e. 5.21% in mine ''A'', and 5.98% in mine ''B''. Thus work and living conditions do not determine general sickness absence rate. The highest absence in both mines was that of miners frequently falling ill for a long time (approx. 5.5% miners). For the group the number of work disablement days was 28.8 and 26.7, respectively. Underground miners' sickness absence was higher than that of surface workers, the rate being 3.8 and 4.0 and 1.1 and 2.1, respectively. The highest absence was that of miners travelling to work on motor cycles (7.1 and 7.3) and bicycles (6.4 and 6.7). Those working regularly in the first shift were more frequently absent from work than those working in different shifts. Miners living in worse conditions had higher absence rate than those living in flats of a higher standard. Also elderly employees and those having children represented a higher absence rate. The highest absence rate was that of workers having four children, the lowest--that of single persons. In addition, specific absence rate of men, especially due to respiratory and circulatory system diseases, was found to be enhanced by smoking. Absence rate of smokers was 2--3 times higher than that of non-smokers.

  1. Sickness Absence: a Pan-European Study

    OpenAIRE

    Livanos, Ilias; Zangelidis, Alexandros

    2010-01-01

    This study, using the EU-LFS, examines the determinants of sickness absence in 26 EU countries. The analysis highlights the importance of demographic and workplace characteristics and of institutional and societal conditions. Female workers aged 26-35 exhibit higher absenteeism, possibly reflecting the level of high household labour pressure. Increased job insecurity, captured by temporary contracts, and labour market uncertainty, reflected in higher unemployment rates, have a negative effect...

  2. Work, Sickness, Absence, and Identity-Work

    OpenAIRE

    Trude Gjernes

    2013-01-01

    This article explores how a group of industrial workers experience long-term sickness absence and how they cope with this situation. The article presents data from in-depth interviews with male industrial workers employed in a Norwegian factory. The findings suggest that the factory workers handle their failing health by engaging in activities other than wage work. They did not accept a social situation characterized by passivity, social isolation, marginalization, or loss of self. The worker...

  3. GPs' negotiation strategies regarding sick leave for subjective health complaints

    DEFF Research Database (Denmark)

    Nilsen, Stein Tore; Malterud, Kirsti; Werner, Erik L.

    2015-01-01

    Objectives: To explore general practitioners ’(GPs’) specific negotiation strategies regarding sick-leave issues with patientssuffering from subjective health complaints. Design: Focus-group study. Setting: Nine focus-group interviews in three citiesin different regions of Norway. Participants: 48...... GPs (31 men, 17 women; age 32–65), participating in a course dealing with diagnostic practice and assessment of sickness certifi cates related to patients with subjective health complaints. Results: TheGPs identified some specific strategies that they claimed to apply when dealing with the question...... to sick leave. Conclusions and implications: GPs seem to have a conscious approach to negotiations of sickness certification, as they report applying specific strategies to limit the duration of sick leave due to subjective health complaints. This give-and-take way of handling sick leave negotiations has...

  4. Some problems of antibiotic therapy in radiation sickness

    International Nuclear Information System (INIS)

    Shalnova, G.A.

    1975-01-01

    Data on the application of antibiotics and the mechanism of their action in radiation sickness are reviewed. Questions are discussed, such as the effect of antibiotics on the course and outcome of radiation sickness, the development of dysbacteriosis following irradiation, the effect of antibiotics on endogenic infection, the development of resistance of autoflora microbes to antibiotics in an irradiated organism and various aspects of the mechanism of action of antibiotics in radiation sickness. (author)

  5. q-deformed Brownian motion

    CERN Document Server

    Man'ko, V I

    1993-01-01

    Brownian motion may be embedded in the Fock space of bosonic free field in one dimension.Extending this correspondence to a family of creation and annihilation operators satisfying a q-deformed algebra, the notion of q-deformation is carried from the algebra to the domain of stochastic processes.The properties of q-deformed Brownian motion, in particular its non-Gaussian nature and cumulant structure,are established.

  6. Sick Leave and Factors Influencing Sick Leave in Adult Patients with Atopic Dermatitis: A Cross-Sectional Study

    Directory of Open Access Journals (Sweden)

    Harmieke van Os-Medendorp

    2015-03-01

    Full Text Available Background: Little is known about the prevalence of sick leave due to atopic dermatitis (AD. The current literature on factors influencing sick leave is mostly derived from other chronic inflammatory diseases. This study aimed to determine the prevalence of sick leave due to AD and to identify influencing factors. Methods: A cross-sectional study was carried out in adult patients with AD. Outcome measures: sick leave during the two-week and one-year periods, socio-demographic characteristics, disease severity, quality of life and socio-occupational factors. Logistic regression analyses were used to determine influencing factors on sick leave over the two-week period. Results: In total, 253 patients were included; 12% of the patients had to take sick leave in the last two weeks due to AD and 42% in the past year. A higher level of symptom interference (OR 1.26; 95% CI 1.13–1.40 or perfectionism/diligence (OR 0.90; 95% CI 0.83–0.96 may respectively increase or decrease the number of sick leave days. Conclusion: Sick leave in patients with AD is a common problem and symptom interference and perfectionism/diligence appeared to influence it. Novel approaches are needed to deal with symptoms at work or school to reduce the amount of sick leave due to AD.

  7. Sick Leave and Factors Influencing Sick Leave in Adult Patients with Atopic Dermatitis: A Cross-Sectional Study.

    Science.gov (United States)

    van Os-Medendorp, Harmieke; Appelman-Noordermeer, Simone; Bruijnzeel-Koomen, Carla; de Bruin-Weller, Marjolein

    2015-03-27

    Little is known about the prevalence of sick leave due to atopic dermatitis (AD). The current literature on factors influencing sick leave is mostly derived from other chronic inflammatory diseases. This study aimed to determine the prevalence of sick leave due to AD and to identify influencing factors. A cross-sectional study was carried out in adult patients with AD. sick leave during the two-week and one-year periods, socio-demographic characteristics, disease severity, quality of life and socio-occupational factors. Logistic regression analyses were used to determine influencing factors on sick leave over the two-week period. In total, 253 patients were included; 12% of the patients had to take sick leave in the last two weeks due to AD and 42% in the past year. A higher level of symptom interference (OR 1.26; 95% CI 1.13-1.40) or perfectionism/diligence (OR 0.90; 95% CI 0.83-0.96) may respectively increase or decrease the number of sick leave days. Sick leave in patients with AD is a common problem and symptom interference and perfectionism/diligence appeared to influence it. Novel approaches are needed to deal with symptoms at work or school to reduce the amount of sick leave due to AD.

  8. Positive and negative consequences of sick leave for the individual, with special focus on part-time sick leave.

    Science.gov (United States)

    Sieurin, Leif; Josephson, Malin; Vingård, Eva

    2009-01-01

    To describe the consequences of long-term sick leave (>28 days) on working situation, health and lifestyle among employees from the public sector in Sweden. Employees in four county councils and two municipalities on long term sick leave on 1 November 2005 (n = 1,128) answered a questionnaire in February 2006. The response rate was 71.7%. Eighty seven per cent were still on sick leave when the questionnaire was answered: 54% part time and 33% full time. Reporting positive consequences was rare but reporting negative consequences, such as effects on the development of salary, the possibilities of pursuing a career or to change to another job were common. Sick leave seemed to lead to a considerable loss of zest for work, even if the respondents were back in work full time. Regardless of the negative consequences at work, 92% of those on part-time sick leave believed that the part-time sick leave was good for them even if many thought it had negative consequences for employer and colleagues. Long-term sick leave has negative consequences for the individual in work situations, even for those back at work full time. The development of salary and career seem to be most affected. The attitude towards part-time sick leave was positive and this result indicates that there is a potential for an increased degree of partial return to work in the group of people on long-term sick leave.

  9. The analytic gradient with a reduced molecular orbital space for the equation-of-motion coupled-cluster theory: systematic study of the magnitudes and trends in simple molecules

    International Nuclear Information System (INIS)

    Baeck, Kyoung K.; Jeon, Sang Il

    2000-01-01

    The analytic gradient method for the equation-of-motion coupled-cluster singles and doubles (EOM-CCSD) energy has been extended to employ a reduced molecular orbital (MO) space. Not only the innermost core MO s but also some of the outermost virtual MO s can be dropped in the reduced MO space, and a substantial amount of computation time can be reduced without deteriorating the results. In order to study the magnitudes and trends of the effects of the dropped MO s , the geometries and vibrational properties of the ground and excited states of BF, CO, CN, N 2 , AlCl, SiS, P 2 , BCl, AlF, CS, SiO, PN and GeSe are calculated with different sizes of molecular orbital space. The 6-31G and the aug-cc-pVTZ basis sets are employed for all molecules except GeSe for which the 6-311 G and the TZV+f basis sets are used. It is shown that the magnitudes of the drop MO effects are about 0.005 A in bond lengths and about 1% on harmonic frequencies and IR intensities provided that the dropped MO s correspond to (1s), (1s,2s,2p), and (1s,2s,2p,3s,3p) atomic orbitals of the first, the second, and the third row atoms, respectively. The geometries and vibrational properties of the first and the second excited states of HCN and HCN are calculated by using a drastically reduced virtual MO space as well as with the well defined frozen core MO space. The results suggest the possibility of using a very small MO space for qualitative study of valence excited states

  10. Paid Sick Leave as a Means to Reduce Sickness Presenteeism Among Physicians

    Directory of Open Access Journals (Sweden)

    Ingrid Steen Rostad

    2017-06-01

    Full Text Available Recurrent international data show that physicians often attend work while ill, termed sickness presenteeism. The current study investigated if sickness presenteeism scores among European physicians varied according to national paid sick leave legislation. We hypothesized that prevalence of presenteeism was higher in countries with lower levels of paid sick leave. We used repeated cross-sectional survey data, phase I (2004/2005, N = 1326 and phase II (2012/2013, N = 1403, among senior consultants at university hospitals in Sweden, Norway, and Italy. Analyses of variances assessed cross-country differences in presenteeism. To assess the impact of country on presenteeism, we used multiple regression analyses controlled for sex, age, family status, work hours, and work content. The results from phase I supported the initial hypothesis. At phase II, presenteeism scores had decreased among the Italian and Swedish sample. The results are discussed with regard to changes in legislation on workhours and medical liability in Italy and Sweden between phase I and II.

  11. Identifying the Subtle Presentation of Decompression Sickness.

    Science.gov (United States)

    Alea, Kenneth

    2015-12-01

    Decompression sickness is an inherent occupational hazard that has the possibility to leave its victims with significant long-lasting effects that can potentially impact an aircrew's flight status. The relative infrequency of this hazard within the military flying community along with the potentially subtle presentation of decompression sickness (DCS) has the potential to result in delayed diagnosis and treatment, leading to residual deficits that can impact a patient's daily life or even lead to death. The patient presented in this work was diagnosed with a Type II DCS 21 h after a cabin decompression at 35,000 ft (10,668 m). The patient had been asymptomatic with a completely normal physical/neurological exam following his flight. The following day, he presented with excessive fatigue and on re-evaluation was recommended for hyperbaric therapy, during which his symptoms completely resolved. He was re-evaluated 14 d later and cleared to resume flight duties without further incident. The manifestation of this patient's decompression sickness was subtle and followed an evaluation that failed to identify any focal findings. A high index of suspicion with strict follow-up contributed to the identification of DCS in this case, resulting in definitive treatment and resolution of the patient's symptoms. Determination of the need for hyperbaric therapy following oxygen supplementation and a thorough history and physical is imperative. If the diagnosis is in question, consider preemptive hyperbaric therapy as the benefits of treatment in DCS outweigh the risks of treatment. Finally, this work introduces the future potential of neuropsychological testing for both the diagnosis of DCS as well as assessing the effectiveness of hyperbaric therapy in Type II DCS.

  12. Changes in alcohol drinking and subsequent sickness absence.

    Science.gov (United States)

    Salonsalmi, Aino; Rahkonen, Ossi; Lahelma, Eero; Laaksonen, Mikko

    2015-06-01

    The aim was to examine whether changes in alcohol drinking are associated with sickness absence. Repeated postal questionnaires on alcohol drinking were conducted among employees of the City of Helsinki in 2000-2 and 2007 to assess changes in drinking habits between these two time points. Data on the number of self-certified and medically confirmed sickness absences were derived from the employer's register. Sickness absences were followed from 2007 until the end of 2010 among employees participating in both questionnaire surveys. The study includes 3252 female and 682 male employees 40-60 years old at baseline. Poisson regression was used in the data analysis and population attributable fractions (PAFs) were calculated. Alcohol drinking was associated especially with self-certified sickness absence. Rate ratios (RRs) and 95% confidence intervals (CIs) for increasing weekly average drinking were 1.38, 1.18-1.62 among women and 1.58, 1.18-2.12 among men. Also stable problem drinking (for women 1.39, 1.26-1.54, for men 1.44, 1.10-1.87) and among women stable heavy drinking (1.53, 1.20-1.94) increased self-certified sickness absence. There were associations between alcohol drinking and medically confirmed sickness absence but these were mainly explained by health and health behaviours. Also, a decrease in weekly average drinking was associated with sickness absence among women whereas among men former problem drinking increased sickness absence. According to the PAF values, problem drinking had a stronger contribution to sickness absence than weekly average drinking. Alcohol drinking is particularly associated with self-certified sickness absence. Reducing adverse drinking habits is likely to prevent sickness absence. © 2015 the Nordic Societies of Public Health.

  13. Sick-visit immunizations and delayed well-baby visits.

    Science.gov (United States)

    Robison, Steve G

    2013-07-01

    Giving recommended immunizations during sick visits for minor and acute illness such as acute otitis media has long been an American Academy of Pediatrics/Advisory Committee on Immunization Practice recommendation. An addition to the American Academy of Pediatrics policy in 2010 advised considering whether giving immunizations at the sick visit would discourage making up missed well-baby visits. This study quantifies the potential tradeoff between sick-visit immunizations and well-baby visits. This study was a retrospective cohort analysis with a case-control component of sick visits for acute otitis media that supplanted normal well-baby visits at age 2, 4, or 6 months. Infants were stratified for sick-visit immunization, no sick-visit immunization but quick makeup well-baby visits, or no sick-visit immunizations or quick makeup visits. Immunization rates and well-baby visit rates were assessed through 24 months of age. For 1060 study cases, no significant difference was detected in immunization rates or well-baby visits through 24 months of age between those with or without sick-visit immunizations. Thirty-nine percent of infants without a sick-visit shot failed to return for a quick makeup well-baby visit; this delayed group was significantly less likely to be up-to-date for immunizations (relative risk: 0.66) and had fewer well-baby visits (mean: 3.8) from 2 through 24 months of age compared with those with sick-visit shots (mean: 4.7). The substantial risk that infants will not return for a timely makeup well-baby visit after a sick visit should be included in any consideration of whether to delay immunizations.

  14. Towards new paradigms for the treatment of hypobaric decompression sickness.

    Science.gov (United States)

    Dart, T S; Butler, W

    1998-04-01

    Altitude induced (hypobaric) decompression sickness (DCS) has long been treated with ground level oxygen and U.S. Navy Treatment Tables 5 and 6. These treatment tables originate from surface excursion diving and, when implemented, require significant resource allocation. Although they are effective treatment regimens, these tables were not developed for treating hypobaric DCS which has an etiology similar to saturation diving DCS. In this review, different treatment options for hypobaric DCS are presented. These options include more aggressive use of ground level oxygen and treatment tables using a maximum pressure of 2 atmospheres (ATA). Specific attention is given to USAF Table VIII, an experimental hypobaric DCS treatment-table, and space suit overpressurization treatment. This paradigm shift for DCS treatment is based on a projected increase in hypobaric DCS treatment from exposure to low pressure during several operational conditions: cruise flight in the next generation aircraft (e.g., F-22); high altitude, unpressurized flight by special operations forces; and the extraordinary amount of extravehicular activity (EVA) required to construct the international space station. Anticipating the need to treat DCS encountered during these and other activities, it is proposed that 2 ATA or less hyperbaric oxygen (HBO) treatment conjoined with new collapsible chamber technology can be used to address these issues in a safe and cost effective fashion.

  15. Systematic review of active workplace interventions to reduce sickness absence.

    Science.gov (United States)

    Odeen, M; Magnussen, L H; Maeland, S; Larun, L; Eriksen, H R; Tveito, T H

    2013-01-01

    The workplace is used as a setting for interventions to prevent and reduce sickness absence, regardless of the specific medical conditions and diagnoses. To give an overview of the general effectiveness of active workplace interventions aimed at preventing and reducing sickness absence. We systematically searched PubMed, Embase, Psych-info, and ISI web of knowledge on 27 December 2011. Inclusion criteria were (i) participants over 18 years old with an active role in the intervention, (ii) intervention done partly or fully at the workplace or at the initiative of the workplace and (iii) sickness absence reported. Two reviewers independently screened articles, extracted data and assessed risk of bias. A narrative synthesis was used. We identified 2036 articles of which, 93 were assessed in full text. Seventeen articles were included (2 with low and 15 with medium risk of bias), with a total of 24 comparisons. Five interventions from four articles significantly reduced sickness absence. We found moderate evidence that graded activity reduced sickness absence and limited evidence that the Sheerbrooke model (a comprehensive multidisciplinary intervention) and cognitive behavioural therapy (CBT) reduced sickness absence. There was moderate evidence that workplace education and physical exercise did not reduce sickness absence. For other interventions, the evidence was insufficient to draw conclusions. The review found limited evidence that active workplace interventions were not generally effective in reducing sickness absence, but there was moderate evidence of effect for graded activity and limited evidence for the effectiveness of the Sheerbrooke model and CBT.

  16. Sick leave analysis among self-employed Dutch farmers

    NARCIS (Netherlands)

    Hartman, E.; Oude Vrielink, H.H.E.; Huirne, R.B.M.; Metz, J.H.M.

    2003-01-01

    Background Agriculture is one of the most physically demanding and risky industries. Aim The objective of this study was to provide baseline data on the diagnoses, occurrence and duration of sick leave of self-employed Dutch farmers. Method A database of 22807 sick leave claims of 12627 farmers

  17. Return to work following sickness absence due to infectious mononucleosis

    NARCIS (Netherlands)

    Koopmans, P.C.; Bakhtali, R.; Katan, A.A.; Groothoff, J.W.; Roelen, C.A.

    BACKGROUND: Epstein-Barr virus infectious mononucleosis among adults is notorious because of the prolonged incapacitating fatigue it causes. AIMS: To investigate the duration of sickness absence and return to work following infectious mononucleosis. METHODS: Episodes of sickness absence due to

  18. Identifying employees at risk for job loss during sick leave

    NARCIS (Netherlands)

    Flach, Peter A.; Groothoff, Johan W.; Bultmann, Ute

    2013-01-01

    Purpose: To examine the associations between medical, work-related, organizational and sociodemographic factors and job loss during sick leave in a Dutch population of 4132 employees on sick leave. Methods: Data were assessed by occupational health physicians (OHPs) on sociodemographic, medical,

  19. Job satisfaction and sickness absence: a questionnaire survey.

    Science.gov (United States)

    Roelen, Corné A M; Koopmans, Petra C; Notenbomer, Annette; Groothoff, Johan W

    2008-12-01

    When dissatisfaction with work precedes sickness absence, screening for satisfaction levels might usefully detect workers at risk of sickness absence. To investigate whether job satisfaction was associated with subsequent sickness absence days or episodes. A sample of workers was randomly drawn from a population of employees who had an episode of absence between January and April 2003. Job satisfaction was measured using a validated single question with a Likert-type scale ranging from 1 (very dissatisfied) to 7 (very satisfied). Job satisfaction levels were linked to the number of recorded sickness absence days and episodes in 2003, distinguishing between short (1-7 days) episodes and long (>7 days) episodes. Of 898 questionnaires distributed, 518 (58%) were returned. The mean+/-standard deviation job satisfaction level was 5.1+/-1.4 and negatively related to the number of sickness absence days. Job satisfaction was also negatively related to the number of short episodes and long episodes of absence, but these associations were not significant. Job satisfaction was significantly related to total sickness absence duration. The association with the number of sickness absence episodes was weak and just below the level of statistical significance. Assessing work satisfaction levels might usefully identify those workers most likely to have the greatest sickness absence duration.

  20. SICK SINUS SYNDROME IN PATIENTS WITH ACUTE CEREBROVASCULAR ACCIDENTS

    Directory of Open Access Journals (Sweden)

    E. K. Kazakova

    2015-01-01

    Full Text Available The article presents a clinical case of 2 patients with heart arrhythmias of the sick sinus syndrome type, who were implanted electriccardiac pacemakers in the acute period of cerebrovascular accidents. There were no cardiac complaints in the clinical manifestation, however, a comprehensive assessment confirmed the diagnosis of sick sinus syndrome.

  1. Does muscle strength predict future musculoskeletal disorders and sickness absence?

    DEFF Research Database (Denmark)

    Faber, A; Sell, L; Hansen, J V

    2012-01-01

    High muscle strength is considered relevant for preventing musculoskeletal disorders and long-term sickness absence. However, prospective studies on the association between muscle strength and future musculoskeletal disorders and long-term sickness absence are few and show contrasting results....

  2. Focus Group Study Exploring Factors Related to Frequent Sickness Absence.

    Science.gov (United States)

    Notenbomer, Annette; Roelen, Corné A M; van Rhenen, Willem; Groothoff, Johan W

    2016-01-01

    Research investigating frequent sickness absence (3 or more episodes per year) is scarce and qualitative research from the perspective of frequent absentees themselves is lacking. The aim of the current study is to explore awareness, determinants of and solutions to frequent sickness absence from the perspective of frequent absentees themselves. We performed a qualitative study of 3 focus group discussions involving a total of 15 frequent absentees. Focus group discussions were audiotaped and transcribed verbatim. Results were analyzed with the Graneheim method using the Job Demands Resources (JD-R) model as theoretical framework. Many participants were not aware of their frequent sickness absence and the risk of future long-term sickness absence. As determinants, participants mentioned job demands, job resources, home demands, poor health, chronic illness, unhealthy lifestyles, and diminished feeling of responsibility to attend work in cases of low job resources. Managing these factors and improving communication (skills) were regarded as solutions to reduce frequent sickness absence. The JD-R model provided a framework for determinants of and solutions to frequent sickness absence. Additional determinants were poor health, chronic illness, unhealthy lifestyles, and diminished feeling of responsibility to attend work in cases of low job resources. Frequent sickness absence should be regarded as a signal that something is wrong. Managers, supervisors, and occupational health care providers should advise and support frequent absentees to accommodate job demands, increase both job and personal resources, and improve health rather than express disapproval of frequent sickness absence and apply pressure regarding work attendance.

  3. Sickness Behaviour: Causes and Effects | Viljoen | South African ...

    African Journals Online (AJOL)

    This paper discusses sickness behaviour as a central motivational state. It deals with the adaptational value and underlying mechanisms of sickness behaviour and with the consequences of the body's failure to terminate the activity of the symptoms-producing cytokines. SA Fam Pract 2003;45(10):15-18 ...

  4. Identifying workers at risk of sickness absence by questionnaire

    NARCIS (Netherlands)

    Roelen, Corne A. M.; van der Pol, Tjepke R.; Koopmans, Petra C.; Groothoff, Johan W.

    2006-01-01

    Background Sickness absence is an important economic problem, because of high costs and lost productivity. Determining factors associated with increased risk of sickness absence may lead to the development of preventive measures. Aims To determine whether self-report questionnaires can identify

  5. Current problems of prevention diagnosis and treatment of radiation sickness

    International Nuclear Information System (INIS)

    Gus'kova, A.K.

    1986-01-01

    Causes of increasing interest to the problems of prevention, diagnosis and treatment of radiation sickness are presented. On the basis of recent publications some new aspects as quantitative criteria in radiobiology, organization problems of medical aid at radiation incidents estimation of efficiency of preventive medicine and radiation sickness therapy, theoretical development of radiotherapy of different organs et al., are characterized

  6. Subjective health complaints in relation to sickness absence

    NARCIS (Netherlands)

    Roelen, Corne A. M.; Koopmans, Petra C.; Groothoff, Johan W.

    2010-01-01

    Objective: The Dutch population is healthy in terms of living and working conditions, but the levels of subjective health complaints (SHC) and sickness absence are high in the Dutch workforce. Are SHC related to sickness absence? Participants: The study population included the personnel of four

  7. Avoidable sickness absence in a dutch working population

    NARCIS (Netherlands)

    Kremer, A.M.; Steenbeek, R.

    2010-01-01

    Introduction Sickness absence has an important impact on employers (e.g. reduced productivity, high costs) and employees (e.g. replacement, job loss). Therefore, we investigated possible reduction by exploring avoidable sickness absence. Methods A questionnaire was filled out by 2,954 Dutch workers

  8. Sickness absence frequency among women working in hospital care

    NARCIS (Netherlands)

    Roelen, Corne A. M.; Schreuder, Jolanda A. H.; Koopmans, Petra C.; Moen, Bente E.; Groothoff, Johan W.

    2009-01-01

    Background Frequent short sickness absences result in understaffing and interfere with work processes. We need more knowledge about factors associated with this type of absence. Aims To investigate associations between the frequency of previous sickness absence and self-reported perceptions of

  9. Suggested classification of acute radiation sickness

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Guo; Mingyue, Zhu; Zhiqin, Zhao

    1984-08-01

    Acute radiation sickness is usually classified into three types. Over the last decade, we have been engaged in experimental studies on the classification of this syndrome. Our findings from these studies, however, point to the fact that between the hemopoietic and intestinal types, and between the intestinal and cerebral types there are transitive forms, namely, hemopoieto-intestinal type and cardio-vascular type, respectively. In this article the required radiation doses and the clinical courses of these transitive forms with special emphasis on their histological and clinical manifestations are described. In case of the hemopoieto-intestinal form, histological examination may reveal residual crypts and typical ''abnormal cells'' in the intestinal mucosa, and clinical manifestations include almost the whole spectrum of symptoms and signs of infection and hemorrhage. The watery stool in pink colour may be specific and helpful in diagnosis. In case of the cardio-vascular form, shock may occur immediately after exposure, and histological examination may show myocardial edema, hemorrhage, cell-infiltration and even necrosis. We propose that the acute radiation sickness should be divided into 5 forms, namely, hemopoietic, hemopoieto-intestinal, intestinal, cardio-vascular and cerebral types. Accurate diagnosis can only be made by taking an comprehensive view of radiation dose, clinical course, clinical manifestations and histological findings. (author).

  10. A suggested classification of acute radiation sickness

    International Nuclear Information System (INIS)

    Guo Yao; Zhu Mingyue; Zhao Zhiqin

    1984-01-01

    Acute radiation sickness is usually classified into three types. Over the last decade, we have been engaged in experimental studies on the classification of this syndrome. Our findings from these studies, however, point to the fact that between the hemopoietic and intestinal types, and between the intestinal and cerebral types there are transitive forms, namely, hemopoieto-intestinal type and cardio-vascular type, respectively. In this article the required radiation doses and the clinical courses of these transitive forms with special emphasis on their histological and clinical manifestations are described. In case of the hemopoieto-intestinal form, histological examination may reveal residual crypts and typical ''abnormal cells'' in the intestinal mucosa, and clinical manifestations include almost the whole spectrum of symptoms and signs of infection and hemorrhage. The watery stool in pink colour may be specific and helpful in diagnosis. In case of the cardio-vascular form, shock may occur immediately after exposure, and histological examination may show myocardial edema, hemorrhage, cell-infiltration and even necrosis. We propose that the acute radiation sickness should be divided into 5 forms, namely, hemopoietic, hemopoieto-intestinal, intestinal, cardio-vascular and cerebral types. Accurate diagnosis can only be made by taking an comprehensive view of radiation dose, clinical course, clinical manifestations and histological findings. (author)

  11. The study of thrombocytopenia in sick neonates

    International Nuclear Information System (INIS)

    Aman, I.; Hassan, K.A.; Ahmad, T.M.

    2004-01-01

    Objective: To determine the number of cases and manifestations of thrombocytopenia in sick neonates. Subjects and Methods: A total of 365 neonates from 0-28 days of age admitted with different clinical problems irrespective of birth weight and gestational age were evaluated for thrombocytopenia. These neonates were categorized into five different groups (A-E), which were of neonatal infections, asphyxia neonatorum, preterm and smallness for gestational age, jaundice and miscellaneous respectively. Results: Out of 365 cases, 88 were found to have thrombocytopenia (platelet counts < 150,000 per mm/sup 3/) which was 24.1% of the total. In group A (neonatal infections), out of 152 neonates, 62 had low platelet counts (40.78%). In group B (neonatal asphyxia), out of 90 only 11 had thrombocytopenia (12.2%). In group C (preterm and small for gestational age), out of 60 cases only 9 had thrombocytopenia. In group D (jaundice), all 33 cases had normal platelet counts. In group E (miscellaneous), out of 30 cases only 6 had thrombocytopenia. The common manifestations in thrombocytopenic babies were petechiae and bruises followed by gastrointestinal hemorrhages. The percentage of manifest thrombocytopenia cases was 56.8% and of occult thrombocytopenia 43.1 %. Conclusion: The leading causes of thrombocytopenia in sick neonates are infections, asphyxia, complicated pre- maturity and smallness for gestational age. Apart from the platelet counts the bleeding mainfestations also depend upon the underlying ailments. (author)

  12. Effect of domperidone on radiation sickness

    Energy Technology Data Exchange (ETDEWEB)

    Sakakibara, T; Sato, K [Nihon Univ., Tokyo. School of Medicine; Watari, T; Tanaka, T; Furuta, A

    1981-07-01

    Domperidone was administered to 95 patients with radiation sickness following radiotherapy for various cancers. The chest and the mediastinum were irradiated in 43 patients, the upper and lower abdomen in 40 patients, and the head, neck, and supraclavicular region in 12 patients. As to radiation source, x-ray was used for 46 patients, ..gamma..-ray for 41 patients, electron beam for 3 patients, and more than one radiation was used for 5 patients. The dose given before the onset of radiation sickness totaled 3000 rad in 20 patients, 1000 rad -- 3000 rad in 41, and less than 1000 rad in 34. Domperidone was given to the patients one tablet (5 mg or 10 mg) P.O., 3 times per day before meals, for 1 -- 2 weeks. The overall effective rate of the drug was 68.4%. The 10 mg tablets were slightly more effective than the 5 mg ones. In the patients who were given the drug in a dose of 10 mg, the ameliorating rate of subjective symptoms was 68.1% for nausea, 88.9% for vomiting, 44.6% for anorexia, 17.5% for general fatigue, and 69.2% for dizziness. Laboratory findings showed no abnormal effects of the drug. One patient had itching with eruptions, which, however, was mild and disappeared immediately after withdrawal of the medication.

  13. Drugs in space: Pharmacokinetics and pharmacodynamics in astronauts.

    Science.gov (United States)

    Kast, Johannes; Yu, Yichao; Seubert, Christoph N; Wotring, Virginia E; Derendorf, Hartmut

    2017-11-15

    Space agencies are working intensely to push the current boundaries of human spaceflight by sending astronauts deeper into space than ever before, including missions to Mars and asteroids. Spaceflight alters human physiology due to fluid shifts, muscle and bone loss, immune system dysregulation, and changes in the gastrointestinal tract and metabolic enzymes. These alterations may change the pharmacokinetics and/or pharmacodynamics of medications used by astronauts and subsequently might impact drug efficacy and safety. Most commonly, medications are administered during space missions to treat sleep disturbances, allergies, space motion sickness, pain, and sinus congestion. These medications are administered under the assumption that they act in a similar way as on Earth, an assumption that has not been investigated systematically yet. Few inflight pharmacokinetic data have been published, and pharmacodynamic and pharmacokinetic/pharmacodynamic studies during spaceflight are also lacking. Therefore, bed-rest models are often used to simulate physiological changes observed during microgravity. In addition to pharmacokinetic/pharmacodynamic changes, decreased drug and formulation stability in space could also influence efficacy and safety of medications. These alterations along with physiological changes and their resulting pharmacokinetic and pharmacodynamic effects must to be considered to determine their ultimate impact on medication efficacy and safety during spaceflight. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Parental availability for the care of sick children.

    Science.gov (United States)

    Heymann, S J; Earle, A; Egleston, B

    1996-08-01

    Parents have always played a critical role in the care of sick children. Although parents' roles remain crucial to children's health, parental availability has declined during the past half century. The percentage of women with preschool children who work has risen almost fivefold in 45 years from 12% in 1947 to 58% in 1992. The percentage of women in the paid work force with school-aged children has almost tripled in the same period, from 27.3% to 75.9%. Research has examined the effects of a variety of parental work conditions on children. However, past research has not examined how working conditions affect the ability of parents to care for their sick children. In this article, we examine how often the children of working parents get sick and whether parents receive enough paid leave to care for their sick children. This analysis makes use of two national surveys, which provide complementary information regarding the care of sick children. The National Longitudinal Survey of Youth is a longitudinal survey of a nationally representative probability sample of 12,686 men and women; the National Medical Expenditure Survey is a panel survey of 34,459 people. First, we estimated the family illness burden. Second, we looked in detail at the number of days of sick leave mothers had. Third, we examined whether mothers who had sick leave had it consistently during a 5-year period. Finally, we conducted a logistic regression to determine what factors were significant predictors of both lacking sick leave. More than one in three families faced a family illness burden of 2 weeks or more each year. Yet, 28% of mothers had sick leave none of the time they were employed between 1985 and 1990. Employed mothers of children with chronic conditions had less sick leave than other employed mothers. Thirty-six percent of mothers whose children had chronic conditions had sick leave none of the time they were employed. Although 20% of working parents who did not live in poverty lacked

  15. Analyzing sickness absence with statistical models for survival data

    DEFF Research Database (Denmark)

    Christensen, Karl Bang; Andersen, Per Kragh; Smith-Hansen, Lars

    2007-01-01

    OBJECTIVES: Sickness absence is the outcome in many epidemiologic studies and is often based on summary measures such as the number of sickness absences per year. In this study the use of modern statistical methods was examined by making better use of the available information. Since sickness...... absence data deal with events occurring over time, the use of statistical models for survival data has been reviewed, and the use of frailty models has been proposed for the analysis of such data. METHODS: Three methods for analyzing data on sickness absences were compared using a simulation study...... involving the following: (i) Poisson regression using a single outcome variable (number of sickness absences), (ii) analysis of time to first event using the Cox proportional hazards model, and (iii) frailty models, which are random effects proportional hazards models. Data from a study of the relation...

  16. Explanation of diagnosis criteria for radiation sickness from internal exposure

    International Nuclear Information System (INIS)

    Xing Zhiwei; Jiang Enhai; Du Jianying; Bai Guang

    2012-01-01

    A revised edition of the Diagnostic Criteria for Radiation Sickness from Internal Exposure has been approved and issued by the Ministry of Health. It is necessary to research the internal radiation sickness to adapt to the current serious anti-terrorism situation. This standard was enacted based on the extensive research of related literature, from which 12 cases with internal radiation sickness and screened out were involving 7 types of radionuclide. The Development of Emergency Response Standard Extension Framework: Midterm Evaluation Report is the main reference which approved by the International Atomic Energy Agency and World Health Organization. This amendment contains many new provisions such as internal radiation sickness effects models and threshold dose, and the appendix added threshold dose of serious deterministic effects induced by radionuclide intake and radiotoxicology parameters of some radionuclides. In order to understand and implement this standard, and to diagnose and treat the internal radiation sickness correctly, the contents of this standard were interpreted in this article. (authors)

  17. Addendum to: Modelling duality between bound and resonant meson spectra by means of free quantum motions on the de Sitter space-time dS{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Kirchbach, M. [Instituto de Fisica, UASLP, San Luis Potosi (Mexico); Compean, C.B. [Instituto Tecnologico de San Luis Potosi, Soledad de Graciano Sanchez (Mexico)

    2017-04-15

    In the article under discussion the analysis of the spectra of the unflavored mesons lead us to some intriguing insights into the possible geometry of space-time outside the causal Minkowski light cone and into the nature of strong interactions. In applying the potential theory concept of geometrization of interactions, we showed that the meson masses are best described by a confining potential composed by the centrifugal barrier on the three-dimensional spherical space, S{sup 3}, and of a charge-dipole potential constructed from the Green function to the S{sup 3} Laplacian. The dipole potential emerged in view of the fact that S{sup 3} does not support single-charges without violation of the Gauss theorem and the superposition principle, thus providing a natural stage for the description of the general phenomenon of confined charge-neutral systems. However, in the original article we did not relate the charge-dipoles on S{sup 3} to the color neutral mesons, and did not express the magnitude of the confining dipole potential in terms of the strong coupling α{sub S} and the number of colors, N{sub c}, the subject of the addendum. To the amount S{sup 3} can be thought of as the unique closed space-like geodesic of a four-dimensional de Sitter space-time, dS{sub 4}, we hypothesized the space-like region outside the causal Einsteinian light cone (it describes virtual processes, among them interactions) as the (1+4)-dimensional subspace of the conformal (2+4) space-time, foliated with dS{sub 4} special relativity for strong interaction processes. The potential designed in this way predicted meson spectra of conformal degeneracy patterns, and in accord with the experimental observations. We now extract the α{sub s} values in the infrared from data on meson masses. The results obtained are compatible with the α{sub s} estimates provided by other approaches. (orig.)

  18. Scaling of the space-time correlation function of particle currents in a suspension of hard-sphere-like particles: exposing when the motion of particles is Brownian.

    Science.gov (United States)

    van Megen, W; Martinez, V A; Bryant, G

    2009-12-18

    The current correlation function is determined from dynamic light scattering measurements of a suspension of particles with hard spherelike interactions. For suspensions in thermodynamic equilibrium we find scaling of the space and time variables of the current correlation function. This finding supports the notion that the movement of suspended particles can be described in terms of uncorrelated Brownian encounters. However, in the metastable fluid, at volume fractions above freezing, this scaling fails.

  19. Sickness benefit cuts mainly affect blue-collar workers.

    Science.gov (United States)

    Aaviksoo, E; Kiivet, R-A

    2014-08-01

    To analyse the impact of sick-pay cuts on the use of sickness absence by employees of different socioeconomic groups. In 2009 cuts in sick pay were implemented in reaction to an economic crisis in Estonia. Nationwide health survey data from the years 2004, 2006, 2008, and 2010 were used to evaluate sickness absence among blue-collar and white-collar workers. The dataset comprised 7,449 employees of 20-64 years of age. Difference in prevalence of absentees before and after the reform was assessed using the chi-squared test. Odds ratios (OR) for sickness absence were calculated in a multivariate logistic regression model. After the reform, the proportion of blue-collar workers who had been on sick leave decreased from 51% to 40% (pgender, age, self-rated health, and presence of chronic disease, especially among those with low incomes; in white-collar employees it reached statistical significance only in those with good self-rated health (p=0.033). In a multivariate model the odds of having lower sickness absence were highly significant only in blue-collar employees (OR 0.63; 95% confidence interval 0.51-0.77, p<0.001). The cuts in sickness benefits had a major impact on the use of sickness absence by blue-collar employees with low salaries. This indicates that lower income was a major factor hindering the use of sick leave as these employees are most vulnerable to the loss of income. © 2014 the Nordic Societies of Public Health.

  20. How physicians have learned to handle sickness-certification cases.

    Science.gov (United States)

    Löfgren, Anna; Silén, Charlotte; Alexanderson, Kristina

    2011-05-01

    Sickness absence is a common ''prescription'' in health care in many Western countries. Despite the significance of sick-listing for the life situation of patients, physicians have limited training in how to handle sickness-certification cases and the research about sickness-certification practices is scarce. Gain knowledge on physicians' learning regarding management of sickness certification of patients in formal, informal, and non-formal learning situations, respectively, and possible changes in this from 2004 to 2008. Data from two comprehensive questionnaires to physicians in Sweden about their sickness-certification practice in 2004 (n = 7665) and 2008 (n = 36,898); response rates: 71% and 61%, respectively. Answers from all the physicians ≤64 years old and who had sickness certification tasks (n = 4019 and n = 14,210) were analysed. ratings of importance of different types of learning situations for their sickness-certification competence. Few physicians stated that formal learning situations had contributed to a large or fairly large extent to their competence in sickness certification, e.g. undergraduate studies had done that for 17%, internship for 37%, and resident training for 46%, respectively. Contacts with colleagues had been helpful for 65%. One-third was helped by training arranged by social insurance offices. There was a significant increase between 2004 and 2008 in all items related to formal and non-formal learning situations, while there were no changes regarding informal learning situations. This study of all physicians in Sweden shows that physicians primarily attain competence in sickness certification in their daily clinical practice; through contacts with colleagues and patients.

  1. Medically certified sickness absence among health care workers.

    Science.gov (United States)

    Khawaja, Rajab Ali; Sikander, Raheel; Khawaja, Asad Ali; Jareno, Rechel Joy Macadaan; Halepota, Aurangzeb Taj

    2012-09-01

    To compare the days and spells of sickness absence among males versus females and Saudi nationals versus expatriate employees of King Khalid University Hospital, Riyadh, and to identify the cause of sickness absence. The cross-sectional, descriptive study comprised 3117 King Khalid University Hospital employees. Records of physician-certified sickness absence from January 1 to June 30, 2009, were obtained from the employee health clinic's register. Absence rate, frequency, duration and severity were assessed and compared between genders and nationalities, and causes were noted. SPSS version 16 and student's t test were used for statistical analyses and comparison. A total of 377 (12.1 %) employees had 416 spells of sickness absence with 639 sick-off days (mean: 1.54 +/- 0.85). The probability of sickness absence was higher among Saudi (OR=1.33) and female (OR=1.39) employees. The association of sickness absence was not found among the absentees with either gender (p= 0.335) or nationality (p = 0.086). Almost all spells of sick-off days were of short duration. Longer spells were mainly due to chicken pox which was found to be more among the expatriates. Heavy absenteeism was found only among the Saudis. The most common causes of sickness absence were acute upper respiratory infection, diseases of musculoskeletal system and the digestive system. The rate, frequency and duration of absence due to sickness in the study were higher among Saudi and female employees. The rate of absence, with passage of time, has increased significantly among Saudi nationals.

  2. Network and user interface for PAT DOME virtual motion environment system

    Science.gov (United States)

    Worthington, J. W.; Duncan, K. M.; Crosier, W. G.

    1993-01-01

    The Device for Orientation and Motion Environments Preflight Adaptation Trainer (DOME PAT) provides astronauts a virtual microgravity sensory environment designed to help alleviate tye symptoms of space motion sickness (SMS). The system consists of four microcomputers networked to provide real time control, and an image generator (IG) driving a wide angle video display inside a dome structure. The spherical display demands distortion correction. The system is currently being modified with a new graphical user interface (GUI) and a new Silicon Graphics IG. This paper will concentrate on the new GUI and the networking scheme. The new GUI eliminates proprietary graphics hardware and software, and instead makes use of standard and low cost PC video (CGA) and off the shelf software (Microsoft's Quick C). Mouse selection for user input is supported. The new Silicon Graphics IG requires an Ethernet interface. The microcomputer known as the Real Time Controller (RTC), which has overall control of the system and is written in Ada, was modified to use the free public domain NCSA Telnet software for Ethernet communications with the Silicon Graphics IG. The RTC also maintains the original ARCNET communications through Novell Netware IPX with the rest of the system. The Telnet TCP/IP protocol was first used for real-time communication, but because of buffering problems the Telnet datagram (UDP) protocol needed to be implemented. Since the Telnet modules are written in C, the Adap pragma 'Interface' was used to interface with the network calls.

  3. Motion of a particle in a radial space-charge field and in an axial magnetic field; Le mouvement d'une particule dans un champ de charge d'espace radial et un champ magnetique axial

    Energy Technology Data Exchange (ETDEWEB)

    Canobbio, E [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires. Services de Physique Appliquee, Service d' Ionique Generale, Section d' Etudes des Interactions Ondes Plasmas; Finzi, U [Institut de Physique Theorique de Milan (Italy)

    1966-07-01

    The motion of a charged particle in an axial uniform steady magnetic field, under the action of a radial space charge is calculated. A cylindrical symmetric charge distribution similar to the one which is observed in HF plasma accelerators is assumed. The particle motion is discussed with the method of effective potentials. A radial acceleration of ions is shown to be possible if the space charge density is sufficiently high. The displacement of the turning points of the trajectories due to the electrostatic field is calculated in the low plasma density approximation. Finally a HF circularly polarized electric field is introduced, the shift in cyclotron resonance is calculated and a low frequency resonance is found to be possible. (authors) [French] On etudie le mouvement d'une particule dans un champ magnetique axial uniforme et constant en presence d'un champ de charge d'espace radial. On considere une distribution de charge a symetrie cylindrique, semblable a celle qu'on observe dans les accelerateurs de plasma a H.F. On se sert des potentiels effectifs pour discuter les caracteristiques du mouvement. Une acceleration radiale des ions est possible lorsque la densite de charge est assez elevee. On calcule aussi les deplacements des points de rebroussement des trajectoires produits par un champ electrostatique faible. On introduit enfin un champ electrique HF polarise circulairement et on calcule le deplacement de la resonance de cyclotron du au champ de charge d'espace. En meme temps on voit apparaitre dans l'energie cinetique de la particule une resonance a basse frequence. (auteurs)

  4. Pilot Studies on Object Motion Perception During Linear Self-Motion After Long Duration Centrifugation of Human Subjects

    Science.gov (United States)

    1993-02-01

    Taylor & Creelman , 1967.) Measurements were taken with the sled moving either in forward or backward direction, each threshold being measured once...Furrer, R. & Messerschmid, E. (1990). Space Sickness on Earth. Experimental Brain Research 79(3), 661-663. Taylor, M.M. & Creelman . C.D. (1967). PEST

  5. Feeling Motion

    DEFF Research Database (Denmark)

    Thelle, Mikkel

    2015-01-01

    The article relates the study of mobility history to the fields of history of emotion and affect theory in the promotion of a cross-disciplinary research agenda. Taking as its point of departure a workshop in Copenhagen on feeling and space, the text draws lines and points of potential interface...... between historical mobility studies and the two related fields....

  6. 46 CFR 168.15-35 - Hospital space.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Hospital space. 168.15-35 Section 168.15-35 Shipping... VESSELS Accommodations § 168.15-35 Hospital space. (a) Each vessel must be provided with a hospital space. This space must be situated with due regard for the comfort of the sick so that they may receive proper...

  7. Space space space

    CERN Document Server

    Trembach, Vera

    2014-01-01

    Space is an introduction to the mysteries of the Universe. Included are Task Cards for independent learning, Journal Word Cards for creative writing, and Hands-On Activities for reinforcing skills in Math and Language Arts. Space is a perfect introduction to further research of the Solar System.

  8. Home care services for sick children

    DEFF Research Database (Denmark)

    Castor, Charlotte; Hallström, Inger; Hansson, Eva Helena

    2017-01-01

    as challenging for healthcare professionals in home care services used to providing care predominately for adults. DESIGN: An inductive qualitative design. METHOD: Seven focus group interviews were performed with 36 healthcare professionals from multidisciplinary home care services. Data were analysed stepwise......AIMS AND OBJECTIVES: To explore healthcare professionals' conceptions of caring for sick children in home care services. BACKGROUND: Families often prefer home care to hospital care, and the number of home care services for children is increasing. Caring for children at home has been recognised...... using a phenomenographic analysis. RESULTS: Three description categories emerged: "A challenging opportunity", "A child perspective", and "Re-organise in accordance with new prerequisites." Providing home care services for children was conceived to evoke both professional and personal challenges...

  9. Associations between work stress, alcohol consumption and sickness absence.

    Science.gov (United States)

    Vasse, R M; Nijhuis, F J; Kok, G

    1998-02-01

    To test an interactional model on the associations between work stressors, perceived stress, alcohol consumption and sickness absence. Cross-sectional survey. The study was part of a Worksite Health Project including an Employee Assistance Programme and a Health Promotion Programme in the Netherlands. Participants were blue-collar workers from two Municipal Garbage Collecting Departments and white-collar workers from a Pharmaceutical Company (N = 471). Measurements included socio-demographic characteristics (gender, age, education, marital status), work stressors, perceived stress, alcohol consumption and sickness absence. Type of work-site (blue- or white-collar) and smoking behaviour were used as covariates. Regression analyses resulted in three major findings. First, in the presence of stress, abstinence increased the risk of sickness absence compared with moderate drinking. We failed to find a significant relationship between excessive drinking and sickness absence. Secondly, stress mediated the associations between stressor and alcohol consumption, and between stressor and sickness absence, although stressors also directly predicted sickness absence. The association between abstinence and sickness absence could reflect medical problems of abstainers or a lack of skills for coping with stress. The failure to find a significant detrimental effect of excessive drinking may have been due to use of a low threshold for excessive drinking and/or low power. Prospective studies are needed to gain insight in causal relationships between the variables concerned.

  10. Work health determinants in employees without sickness absence.

    Science.gov (United States)

    Schell, E; Theorell, T; Nilsson, B; Saraste, H

    2013-01-01

    Working ability is known to be related to good physical condition, clear work tasks, positive feedback and other occupational, organizational and psychosocial factors. In Sweden, high levels of sickness absence are due to stress-related disorders and musculoskeletal pain. To identify work health characteristics in a working population with a large variety of professional skills and occupational tasks. Employers' data on occupation, sickness absence, age and gender in a working population of 11 occupational groups and questionnaire responses regarding work-organization, environment, work stress, pain, health, and socio-demographic factors were collected. Employees with no history of sick-leave were compared with those with a history of sick-leave (1-182 days, mean 25 days). Of 2641 employees, 1961 participated. Those with no history of sick-leave reported less work-related pain, work-related stress, sleep disturbances, worry about their health, 'sick-presenteeism', monotonous work, bent and twisted working positions and exposure to disturbing noise than those with a history of sick-leave (P health, support from superiors, having influence on their working hours and evening and week-end working, longer working hours per week (P health and less neck, shoulder and back pain and more support from their superiors and influence on their working hours.

  11. Student nurses experience of a "fairy garden" healing haven garden for sick children.

    Science.gov (United States)

    van der Riet, Pamela; Jitsacorn, Chaweewan; Junlapeeya, Piyatida; Thursby, Peter

    2017-12-01

    The concept and philosophy of healing environments in health care is not new and there has been recent research into the experience of nurses and families experience of healing environments producing positive outcomes in relieving stress and improving quality of life. However, there is little in-depth information about student nurse's experience of healing environments in support of patients. To report on the stories of student nurses who participated in formal and informal activities in a healing haven environment called a Fairy Garden (FG) within a hospital in northern Thailand. Their beliefs about the care of sick children in an environment designed to provide educational and recreational activity during hospital care are explored. Narrative inquiry, a qualitative methodology was selected to capture the main threads of the participants' experience. Clandinin's narrative inquiry framework involving the three commonality dimensions of sociality, temporality and place were used in analysing the data. Sixty-two student nurses from a Thai College of Nursing and from an Australian university were interviewed. In this study the place of a FG has been investigated as a non-clinical environment providing sick children with exposure to nature, play activities and spaces to explore. Findings include three main threads: freedom to be a child not a sick child, engaging in care and professionalism, a moment in time of living fantasy. Student nurses in this study had a broader understanding of health care other than the biomedical model. It transformed their learning and opened their eyes to a more holistic approach to humanising care of sick children. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Force and motion

    CERN Document Server

    Robertson, William C

    2002-01-01

    Intimidated by inertia? Frightened by forces? Mystified by Newton s law of motion? You re not alone and help is at hand. The stop Faking It! Series is perfect for science teachers, home-schoolers, parents wanting to help with homework all of you who need a jargon-free way to learn the background for teaching middle school physical science with confidence. With Bill Roberton as your friendly, able but somewhat irreverent guide, you will discover you CAN come to grips with the basics of force and motion. Combining easy-to-understand explanations with activities using commonly found equipment, this book will lead you through Newton s laws to the physics of space travel. The book is as entertaining as it is informative. Best of all, the author understands the needs of adults who want concrete examples, hands-on activities, clear language, diagrams and yes, a certain amount of empathy. Ideas For Use Newton's laws, and all of the other motion principles presented in this book, do a good job of helping us to underst...

  13. GPs' negotiation strategies regarding sick leave for subjective health complaints.

    Science.gov (United States)

    Nilsen, Stein; Malterud, Kirsti; Werner, Erik L; Maeland, Silje; Magnussen, Liv Heide

    2015-03-01

    To explore general practitioners' (GPs') specific negotiation strategies regarding sick-leave issues with patients suffering from subjective health complaints. Focus-group study. Nine focus-group interviews in three cities in different regions of Norway. 48 GPs (31 men, 17 women; age 32-65), participating in a course dealing with diagnostic practice and assessment of sickness certificates related to patients with subjective health complaints. The GPs identified some specific strategies that they claimed to apply when dealing with the question of sick leave for patients with subjective health complaints. The first step would be to build an alliance with the patient by complying with the wish for sick leave, and at the same time searching for information to acquire the patient's perspective. This position would become the basis for the main goal: motivating the patient for a rapid return to work by pointing out the positive effects of staying at work, making legal and moral arguments, and warning against long-term sick leave. Additional solutions might also be applied, such as involving other stakeholders in this process to provide alternatives to sick leave. GPs seem to have a conscious approach to negotiations of sickness certification, as they report applying specific strategies to limit the duration of sick leave due to subjective health complaints. This give-and-take way of handling sick-leave negotiations has been suggested by others to enhance return to work, and should be further encouraged. However, specific effectiveness of this strategy is yet to be proven, and further investigation into the actual dealings between doctor and patients in these complex encounters is needed.

  14. Health-related behaviours and sickness absence from work.

    Science.gov (United States)

    Laaksonen, M; Piha, K; Martikainen, P; Rahkonen, O; Lahelma, E

    2009-12-01

    To compare associations of health-related behaviours with self-certified and medically confirmed sickness absence, and to examine whether these associations can be explained by psychosocial and physical working conditions and occupational social class. The study included 5470 female and 1464 male employees of the City of Helsinki surveyed in 2000-2002. These data were linked to sickness absence records until the end of 2005, providing a mean follow-up time of 3.9 years. Poisson regression analysis was used to examine associations of smoking, alcohol use, physical activity, dietary habits and relative weight (body mass index) with self-certified (1-3 days) and medically confirmed (> or =4 days) absence spells. Population attributable fractions (PAFs) were calculated to quantify the sickness absence burden related to the behaviours. Smoking and high relative weight were most strongly associated with sickness absence, while the associations of other studied health-related behaviours were weaker. The associations were stronger for medically confirmed sickness absence spells for which heavy smoking and obesity more than doubled the risk of sickness absence in men and nearly doubled it in women. Adjusting for psychosocial working conditions had little or no effect on the associations. Physical working conditions and social class somewhat attenuated the associations, especially for smoking and relative weight. In self-certified sickness absence the PAF for smoking (16.4 in men, 10.3 in women) was largest, while in medically confirmed absence relative weight had the largest PAF (23.5 in men, 15.0 in women). Health-related behaviours, smoking and high relative weight in particular, were associated with subsequent sickness absence independently of psychosocial and physical working conditions and social class. Decreasing smoking and relative weight is likely to provide important gains in work ability and reduce sickness absence.

  15. Habitat Options to Protect Against Decompression Sickness on Mars

    Science.gov (United States)

    Conkin, J.

    2000-07-01

    Men and women are alive today, although perhaps still in diapers, who will explore the surface of Mars. Two achievable goals to enable this exploration are to use Martian resources, and to provide a safe means for unrestricted access to the surface. A cost-effective approach for Mars exploration is to use the available resources, such as water and atmospheric gases. Nitrogen (N2) and Argon (Ar) in a concentration ratio of 1.68/1.0 are available, and could form the inert gas component of a habitat atmosphere at 8.0, 9.0, or 10.0 pounds per square inch absolute (psia). The habitat and space suit must be designed as an integrated, complementary, system: a comfortable living environment about 85% of the time and a safe working environment about 15% of the time. A goal is to provide a system that permits unrestricted exploration of Mars. However the risk of decompression sickness (DCS) during the extravehicular activity (EVA) in a 3.75 psia suit after exposure to either of the three habitat conditions may limit unrestricted exploration.

  16. Inner ear decompression sickness in compressed-air diving.

    Science.gov (United States)

    Klingmann, Christoph

    2012-01-01

    Inner ear decompression sickness (IEDCS) has become more frequently reported in recreational diving. We examined 34 divers after IEDCS and analyzed their dive profiles, pattern of symptoms, time of symptom onset and the association with a right-to left shunt (r/l shunt). Four divers used mixed gas and were excluded from the analysis. Of the remaining 30 divers, 25 presented with isolated IEDCS alone, while five divers had additional skin and neurological symptoms. All divers presented with vertigo (100%), and 12 divers reported additional hearing loss (40%). All symptoms occurred within 120 minutes (median 30 minutes) of ascent. Twenty-two of 30 divers (73.3%) showed a r/l shunt. A possible explanation for the frequent association of a r/l shunt and the dominance of vestibular rather than cochlear symptoms could be attributed to the different blood supply of the inner ear structures and the different size of the labyrinthine compartments. The cochlea has a blood supply up to four times higher than the vestibular part of the inner ear, whereas the vestibular fluid space is 30% larger. The higher prevalence of symptoms referrable to the less well-perfused vestibular organ provides further evidence that persistent local inert gas supersaturation may cause growth of incoming arterial bubbles and may therefore be an important pathophysiological factor in IEDCS.

  17. Auditory Motion Elicits a Visual Motion Aftereffect

    Directory of Open Access Journals (Sweden)

    Christopher C. Berger

    2016-12-01

    Full Text Available The visual motion aftereffect is a visual illusion in which exposure to continuous motion in one direction leads to a subsequent illusion of visual motion in the opposite direction. Previous findings have been mixed with regard to whether this visual illusion can be induced cross-modally by auditory stimuli. Based on research on multisensory perception demonstrating the profound influence auditory perception can have on the interpretation and perceived motion of visual stimuli, we hypothesized that exposure to auditory stimuli with strong directional motion cues should induce a visual motion aftereffect. Here, we demonstrate that horizontally moving auditory stimuli induced a significant visual motion aftereffect—an effect that was driven primarily by a change in visual motion perception following exposure to leftward moving auditory stimuli. This finding is consistent with the notion that visual and auditory motion perception rely on at least partially overlapping neural substrates.

  18. Auditory Motion Elicits a Visual Motion Aftereffect.

    Science.gov (United States)

    Berger, Christopher C; Ehrsson, H Henrik

    2016-01-01

    The visual motion aftereffect is a visual illusion in which exposure to continuous motion in one direction leads to a subsequent illusion of visual motion in the opposite direction. Previous findings have been mixed with regard to whether this visual illusion can be induced cross-modally by auditory stimuli. Based on research on multisensory perception demonstrating the profound influence auditory perception can have on the interpretation and perceived motion of visual stimuli, we hypothesized that exposure to auditory stimuli with strong directional motion cues should induce a visual motion aftereffect. Here, we demonstrate that horizontally moving auditory stimuli induced a significant visual motion aftereffect-an effect that was driven primarily by a change in visual motion perception following exposure to leftward moving auditory stimuli. This finding is consistent with the notion that visual and auditory motion perception rely on at least partially overlapping neural substrates.

  19. Auditory motion capturing ambiguous visual motion

    Directory of Open Access Journals (Sweden)

    Arjen eAlink

    2012-01-01

    Full Text Available In this study, it is demonstrated that moving sounds have an effect on the direction in which one sees visual stimuli move. During the main experiment sounds were presented consecutively at four speaker locations inducing left- or rightwards auditory apparent motion. On the path of auditory apparent motion, visual apparent motion stimuli were presented with a high degree of directional ambiguity. The main outcome of this experiment is that our participants perceived visual apparent motion stimuli that were ambiguous (equally likely to be perceived as moving left- or rightwards more often as moving in the same direction than in the opposite direction of auditory apparent motion. During the control experiment we replicated this finding and found no effect of sound motion direction on eye movements. This indicates that auditory motion can capture our visual motion percept when visual motion direction is insufficiently determinate without affecting eye movements.

  20. INTERACTIVE MOTION PLATFORMS AND VIRTUAL REALITY FOR VEHICLE SIMULATORS

    Directory of Open Access Journals (Sweden)

    Evžen Thöndel

    2017-12-01

    Full Text Available Interactive motion platforms are intended for vehicle simulators, where the direct interaction of the human body is used for controlling the simulated vehicle (e.g. bicycle, motorbike or other sports vehicles. The second use of interactive motion platforms is for entertainment purposes or fitness. The development of interactive motion platforms reacts to recent calls in the simulation industry to provide a device, which further enhances the virtual reality experience, especially with connection to the new and very fast growing business in virtual reality glasses. The paper looks at the design and control of an interactive motion platform with two degrees of freedom to be used in virtual reality applications. The paper provides the description of the control methods and new problems related to the virtual reality sickness are discussed here.

  1. [Assistance and care of the sick in early Christianity].

    Science.gov (United States)

    Maritano, Mario

    2012-01-01

    Christianity presents a new vision of man (personalistic anthropology) and refers to the example and words of Jesus, highlighting the inseparable relationship between the love of God and the love of man. The article describes the assistance and care of the sick in the East and West in the early Christian centuries; the 'places of care'- nosokomia for the sicks, gerontokomia for the olders, brephotropia for abandoned children, orphanage structures; the managers of hospitals, ecclesistical dignitaries, lay personnel, monks, operators and employees. Christianity gave dignity to the sick and opportunity to serve humanity to the healthy.

  2. Psychosocial work conditions associated with sickness absence among hospital employees

    DEFF Research Database (Denmark)

    Suadicani, P; Olesen, K; Bonde, J P

    2014-01-01

    's salary database. RESULTS: A total of 1809 hospital employees took part with a response rate of 65%. The mean age was 43 (range: 20-69) and 75% were female. Totally, 363 study participants (20%) had at least 14 days sickness absence (defined as high absence) during the preceding year. Associations between...... essential covariates of sickness absence. METHODS: A cross-sectional questionnaire study of hospital employees which sought information on elements of the psychosocial work environment, general health status, life style, age, gender and profession. Data on sickness absence were obtained from the employer...

  3. Managerial leadership is associated with self-reported sickness absence and sickness presenteeism among Swedish men and women.

    Science.gov (United States)

    Nyberg, Anna; Westerlund, Hugo; Magnusson Hanson, Linda L; Theorell, Töres

    2008-11-01

    The objective of this study was to investigate the relationship between managerial leadership and self-reported sickness absence/presenteeism among Swedish men and women. Five thousand one hundred and forty-one Swedish employees, 56% of the participants in a nationally representative sample of the Swedish working population, were included in this cross-sectional questionnaire study. The leadership dimensions measured were five subscales of a standardized leadership questionnaire (Global Leadership and Organizational Behaviour Effectiveness Programme): Integrity, Team integration, Inspirational leadership, Autocratic leadership, and Self-centred leadership. Multiple logistic regression analyses were conducted, adjusting for factors in private life, employment category, labour-market sector, working conditions, self-reported general health, and satisfaction with life in general. Inspirational leadership was associated with a lower rate of short spells of sickness absence (women. Autocratic leadership was related to a greater amount of total sick days taken by men. Sometimes showing integrity was associated with higher rate of sickness absence >1 week among men, and seldom showing integrity was associated with more sickness presenteeism among women. Managers performing Team integration were sometimes associated with women taking fewer short (1 week) spells of sickness absence. Adjustment for self-reported general health did not alter these associations for men, but did so to some extent for women. Managerial leadership was found to be relevant for the understanding of sickness absence in the Swedish working population. There were distinctive gender differences.

  4. The Role of Motion Concepts in Understanding Non-Motion Concepts

    Directory of Open Access Journals (Sweden)

    Omid Khatin-Zadeh

    2017-12-01

    Full Text Available This article discusses a specific type of metaphor in which an abstract non-motion domain is described in terms of a motion event. Abstract non-motion domains are inherently different from concrete motion domains. However, motion domains are used to describe abstract non-motion domains in many metaphors. Three main reasons are suggested for the suitability of motion events in such metaphorical descriptions. Firstly, motion events usually have high degrees of concreteness. Secondly, motion events are highly imageable. Thirdly, components of any motion event can be imagined almost simultaneously within a three-dimensional space. These three characteristics make motion events suitable domains for describing abstract non-motion domains, and facilitate the process of online comprehension throughout language processing. Extending the main point into the field of mathematics, this article discusses the process of transforming abstract mathematical problems into imageable geometric representations within the three-dimensional space. This strategy is widely used by mathematicians to solve highly abstract and complex problems.

  5. Motion control report

    CERN Document Server

    2013-01-01

    Please note this is a short discount publication. In today's manufacturing environment, Motion Control plays a major role in virtually every project.The Motion Control Report provides a comprehensive overview of the technology of Motion Control:* Design Considerations* Technologies* Methods to Control Motion* Examples of Motion Control in Systems* A Detailed Vendors List

  6. Homothetic motions in general relativity

    International Nuclear Information System (INIS)

    McIntosh, C.B.G.

    1976-01-01

    Properties of homothetic or self-similar motions in general relativity are examined with particular reference to vacuum and perfect-fluid space-times. The role of the homothetic bivector with components Hsub((a;b)) formed from the homothetic vector H is discussed in some detail. It is proved that a vacuum space-time only admits a nontrivial homothetic motion if the homothetic vector field is non-null and is not hypersurface orthogonal. As a subcase of a more general result it is shown that a perfect-fluid space-time cannot admit a non-trivial homothetic vector which is orthogonal to the fluid velocity 4-vector. (author)

  7. Undetected common mental disorders in long-term sickness absence

    DEFF Research Database (Denmark)

    Søgaard, Hans Jørgen

    2012-01-01

    Background. Undetected Common Mental Disorders (CMDs) amongst people on sick leave complicate rehabilitation and return to work because appropriate treatments are not initiated. Aims. The aim of this study is to estimate (1) the frequencies of CMD, (2) the predictors of undetected CMD, and (3...... individuals registered on LSA who were sick-listed without a psychiatric sick leave diagnosis. In this respect, Phase 1 included 831 individuals, who were screened for mental disorders. In Phase 2, following the screening of Phase 1, 227 individuals were thoroughly examined by a psychiatrist applying Present...... State Examination. The analyses of the study were carried out based on the 227 individuals from Phase 2 and, subsequently, weighted to be representative of the 831 individuals in Phase 1. Results. The frequencies of undetected mental disorders among all sick-listed individuals were for any psychiatric...

  8. Job demands, job resources, and behavior in times of sickness

    DEFF Research Database (Denmark)

    Schneider, Daniel; Winter, Vera; Schreyögg, Jonas

    2017-01-01

    BACKGROUND: The concept of presenteeism, that is, employees coming to work despite being sick, has recently received more attention in the literature. Presenteeism not only threatens employees' health but also substantially drains productivity and drives considerable costs. When they are sick......, employees have the choice of whether to go to work or to stay at home. Therefore, determinants of (sickness) absenteeism and presenteeism should be examined simultaneously. Nursing homes are faced with a particularly high prevalence of both absenteeism and presenteeism and are therefore a relevant object...... of investigation. PURPOSE: The aim of our study is to analyze the effect of job demands and job resources on absenteeism, presenteeism, and the tendency to choose one behavior (being absent or being present in times of sickness) rather than the other over the last 12 months. To do so, we identify the determinants...

  9. Braid My Hair - Randy Owen sings out for sick children

    Science.gov (United States)

    ... Issue Past Issues Braid My Hair - Randy Owen sings out for sick children Past Issues / Spring 2008 ... to it. Former Alabama lead singer Randy Owen sings his new song, "Braid My Hair." Photo courtesy ...

  10. Gut Feelings About Gastritis: When Your Stomach's Sick

    Science.gov (United States)

    ... November 2012 Print this issue Gut Feelings About Gastritis When Your Stomach’s Sick Send us your comments ... protective response to injury or infection. is called gastritis, and it can cause long-term problems. Some ...

  11. Sickness absence, moral hazard, and the business cycle.

    Science.gov (United States)

    Pichler, Stefan

    2015-06-01

    The procyclical nature of sickness absence has been documented by many scholars in literature. So far, explanations have been based on labor force composition and reduced moral hazard caused by fear of job loss during recessions. In this paper, we propose and test a third mechanism caused by reduced moral hazard during booms and infections. We suggest that the workload is higher during economic booms and thus employees have to go to work despite being sick. In a theoretical model focusing on infectious diseases, we show that this will provoke infections of coworkers leading to overall higher sickness absence during economic upturns. Using state-level aggregated data from 112 German public health insurance funds (out of 145 in total), we find that sickness absence due to infectious diseases shows the largest procyclical pattern, as predicted by our theoretical model. Copyright © 2014 John Wiley & Sons, Ltd.

  12. Identifying risk factors that contribute to acute mountain sickness

    African Journals Online (AJOL)

    Acute mountain sickness (AMS) is an ever-increasing burden on the health sector. With reported incidences .... schedule to reduce the likelihood of AMS. The data ... of Health and. Multidisciplinary Board on Exercise to identify individuals who.

  13. Explanation of nurse standard of external exposure acute radiation sickness

    International Nuclear Information System (INIS)

    Lu Xiuling; Jiang Enhai; Sun Feifei; Zhang Bin; Wang Xiaoguang; Wang Guilin

    2012-01-01

    National occupational health standard-Nurse Standard of External Exposure Acute Radiation Sickness has been approved and issued by the Ministry of Health. Based on the extensive research of literature, collection of the previous nuclear and radiation accidents excessive exposed personnel data and specific situations in China, this standard was enacted according to the current national laws, regulations, and the opinions of peer experts. It is mainly used for care of patients with acute radiation sickness, and also has directive significance for care of patients with iatrogenic acute radiation sickness which due to the hematopoietic stem cell transplantation pretreatment. To correctly carry out this standard and to reasonably implement nursing measures for patients with acute radiation sickness, the contents of this standard were interpreted in this article. (authors)

  14. [Teacher sick leave: Prevalence, duration, reasons and covariates].

    Science.gov (United States)

    Vercambre-Jacquot, M-N; Gilbert, F; Billaudeau, N

    2018-02-01

    Absences from work have considerable social and economic impact. In the education sector, the phenomenon is particularly worrying since teacher sick leave has an impact on the overall performance of the education system. Yet, available data are scarce. In April-June 2013, 2653 teachers responded to a population-based postal survey on their quality of life (enquête Qualité de vie des enseignants, MGEN Foundation/Ministry of education, response rate 53 %). Besides questions on work environment and health, teachers were asked to describe their eventual sick leave(s) since the beginning of the school year: duration, type and medical reasons. Self-reported information was reinforced by administrative data from ministerial databases and weighted to be extrapolated to all French teachers. Tobit models adjusted for individual factors of a private nature were used to investigate different occupational risk factors of teacher sick leave, taking into account both the estimated effect on the probability of sick leave and the length of it. More than one in three teachers (36 %) reported having had at least one day of sick leave since the beginning of the school year. Respiratory/ENT diseases were the leading reason for sick leave (37 %). However, and because sick leave duration depended on the underlying health problem, such diseases came in third place among justifications of sick leave days (14 %), far behind musculoskeletal problems (27 %) and neurological and psychological disorders (25 %). Tobit models suggested that some occupational factors significantly associated with the risk of sick leave may represent promising preventive targets, including high psychological demand, workplace violence and unfavorable socio-environmental context. Our study provides objective evidence about the issue of sick leave among French teachers, highlighting the usefulness of implementing actions to minimize its weight. To this end, the study findings point-out the importance of

  15. Spatial filtering precedes motion detection.

    Science.gov (United States)

    Morgan, M J

    1992-01-23

    When we perceive motion on a television or cinema screen, there must be some process that allows us to track moving objects over time: if not, the result would be a conflicting mass of motion signals in all directions. A possible mechanism, suggested by studies of motion displacement in spatially random patterns, is that low-level motion detectors have a limited spatial range, which ensures that they tend to be stimulated over time by the same object. This model predicts that the direction of displacement of random patterns cannot be detected reliably above a critical absolute displacement value (Dmax) that is independent of the size or density of elements in the display. It has been inferred that Dmax is a measure of the size of motion detectors in the visual pathway. Other studies, however, have shown that Dmax increases with element size, in which case the most likely interpretation is that Dmax depends on the probability of false matches between pattern elements following a displacement. These conflicting accounts are reconciled here by showing that Dmax is indeed determined by the spacing between the elements in the pattern, but only after fine detail has been removed by a physiological prefiltering stage: the filter required to explain the data has a similar size to the receptive field of neurons in the primate magnocellular pathway. The model explains why Dmax can be increased by removing high spatial frequencies from random patterns, and simplifies our view of early motion detection.

  16. Passive infrared motion sensing technology

    International Nuclear Information System (INIS)

    Doctor, A.P.

    1994-01-01

    In the last 10 years passive IR based (8--12 microns) motion sensing has matured to become the dominant method of volumetric space protection and surveillance. These systems currently cost less than $25 to produce and yet use traditionally expensive IR optics, filters, sensors and electronic circuitry. This IR application is quite interesting in that the volumes of systems produced and the costs and performance level required prove that there is potential for large scale commercial applications of IR technology. This paper will develop the basis and principles of operation of a staring motion sensor system using a technical approach. A model for the motion of the target is developed and compared to the background. The IR power difference between the target and the background as well as the optical requirements are determined from basic principles and used to determine the performance of the system. Low cost reflective and refractive IR optics and bandpass IR filters are discussed. The pyroelectric IR detector commonly used is fully discussed and characterized. Various schemes for ''false alarms'' have been developed and are also explained. This technology is also used in passive IR based motion sensors for other applications such as lighting control. These applications are also discussed. In addition the paper will discuss new developments in IR surveillance technology such as the use of linear motion sensing arrays. This presentation can be considered a ''primer'' on the art of Passive IR Motion Sensing as applied to Surveillance Technology

  17. You’re the Flight Surgeon: Pulmonary Decompression Sickness

    Science.gov (United States)

    2008-06-01

    follow-up of this patient Diagnosis: Decompression sickness (DeS) with pulmonary symptoms (Type Il DeS, older nomenclature). Treatment: Hyperbaric ...is quite clear thai any case of suspected decompression sickness in the USAF be discussed with the hyperbariC medicine specialists at Brooks City...physician in as respectful manner as you can that you suspect the patient’s condition is likely related to his hypobaric exposure. B. Agree with

  18. Worried sick? Worker Responses to a Financial Shock

    OpenAIRE

    Bratberg, Espen; Monstad, Karin

    2013-01-01

    Excessive sickness absence may hurt productivity and put a strain on public finances. One explanation put forward for increasing absence rates is that a tougher labour market represents a health hazard. A competing hypothesis is that loss of job security works as a disciplinary device. We use a financial shock that hit the public sector in Norway in 2007 in some, but not all, municipalities to identify the effect of reduced job security on sickness absence. Public sector workers i...

  19. Focus Group Study Exploring Factors Related to Frequent Sickness Absence.

    Directory of Open Access Journals (Sweden)

    Annette Notenbomer

    Full Text Available Research investigating frequent sickness absence (3 or more episodes per year is scarce and qualitative research from the perspective of frequent absentees themselves is lacking. The aim of the current study is to explore awareness, determinants of and solutions to frequent sickness absence from the perspective of frequent absentees themselves.We performed a qualitative study of 3 focus group discussions involving a total of 15 frequent absentees. Focus group discussions were audiotaped and transcribed verbatim. Results were analyzed with the Graneheim method using the Job Demands Resources (JD-R model as theoretical framework.Many participants were not aware of their frequent sickness absence and the risk of future long-term sickness absence. As determinants, participants mentioned job demands, job resources, home demands, poor health, chronic illness, unhealthy lifestyles, and diminished feeling of responsibility to attend work in cases of low job resources. Managing these factors and improving communication (skills were regarded as solutions to reduce frequent sickness absence.The JD-R model provided a framework for determinants of and solutions to frequent sickness absence. Additional determinants were poor health, chronic illness, unhealthy lifestyles, and diminished feeling of responsibility to attend work in cases of low job resources. Frequent sickness absence should be regarded as a signal that something is wrong. Managers, supervisors, and occupational health care providers should advise and support frequent absentees to accommodate job demands, increase both job and personal resources, and improve health rather than express disapproval of frequent sickness absence and apply pressure regarding work attendance.

  20. Systematic review of active workplace interventions to reduce sickness absence

    OpenAIRE

    Odeen, Magnus; Magnussen, Liv Heide; Mæland, Silje; Larun, Lillebeth; Eriksen, Hege Randi; Tveito, Torill Helene

    2013-01-01

    Background: The workplace is used as a setting for interventions to prevent and reduce sickness absence, regardless of the specific medical conditions and diagnoses. Aims: To give an overview of the general effectiveness of active workplace interventions aimed at preventing and reducing sickness absence. Methods: We systematically searched PubMed, Embase, Psych-info, and ISI web of knowledge on 27 December 2011. Inclusion criteria were (i) participants over 18 years old with ...

  1. Decompression sickness in breath-hold divers: a review.

    Science.gov (United States)

    Lemaitre, Frederic; Fahlman, Andreas; Gardette, Bernard; Kohshi, Kiyotaka

    2009-12-01

    Although it has been generally assumed that the risk of decompression sickness is virtually zero during a single breath-hold dive in humans, repeated dives may result in a cumulative increase in the tissue and blood nitrogen tension. Many species of marine mammals perform extensive foraging bouts with deep and long dives interspersed by a short surface interval, and some human divers regularly perform repeated dives to 30-40 m or a single dive to more than 200 m, all of which may result in nitrogen concentrations that elicit symptoms of decompression sickness. Neurological problems have been reported in humans after single or repeated dives and recent necropsy reports in stranded marine mammals were suggestive of decompression sickness-like symptoms. Modelling attempts have suggested that marine mammals may live permanently with elevated nitrogen concentrations and may be at risk when altering their dive behaviour. In humans, non-pathogenic bubbles have been recorded and symptoms of decompression sickness have been reported after repeated dives to modest depths. The mechanisms implicated in these accidents indicate that repeated breath-hold dives with short surface intervals are factors that predispose to decompression sickness. During deep diving, the effect of pulmonary shunts and/or lung collapse may play a major role in reducing the incidence of decompression sickness in humans and marine mammals.

  2. A review of the influence of physical condition parameters on a typical aerospace stress effect: Decompression sickness

    Science.gov (United States)

    West, V. R.; Parker, J. F., Jr.

    1973-01-01

    The study examines data on episodes of decompression sickness, particularly from recent Navy work in which the event occurred under multiple stress conditions, to determine the extent to which decompression sickness might be predicted on the basis of personal characteristics such as age, weight, and physical condition. Such information should ultimately be useful for establishing medical selection criteria to screen individuals prior to participation inactivities involving extensive changes in ambient pressure, including those encountered in space operations. The main conclusions were as follows. There is a definite and positive relationship between increasing age and weight and the likelihood of decompression sickness. However, for predictive purposes, the relationship is low. To reduce the risk of bends, particularly for older individuals, strenuous exercise should be avoided immediately after ambient pressure changes. Temperatures should be kept at the low end of the comfort zone. For space activities, pressure changes of over 6-7 psi should be avoided. Prospective participants in future missions such as the Space Shuttle should not be excluded on the basis of age, certainly to age 60, if their general condition is reasonably good and they are not grossly obese. (Modified author abstract)

  3. Go to work or report sick? A focus group study on decisions of sickness presence among offshore catering section workers.

    Science.gov (United States)

    Krohne, Kariann; Magnussen, Liv Heide

    2011-03-18

    To identify and explore the factors promoting sickness presenteeism among offshore catering section workers. Twenty men and women, working in the offshore catering section onboard three offshore oil and gas production platforms on the Norwegian Continental Shelf, participated in three focus groups. Data from the focus groups were analysed according to a phenomenological approach, and supported by theories on presenteeism. The results show that the decision to attend work despite illness, first and foremost, was based on the severity of the health complaint. Other factors identified were; the individual's location once the health complaint occurred, job satisfaction, the norms of the team, and experiences of how company policies on sickness absenteeism were implemented by the catering section leaders. Offshore working conditions may promote sickness presenteeism. The factors promoting sickness presenteeism onboard the platforms reflected experiences of a healthy work environment.

  4. Go to work or report sick? A focus group study on decisions of sickness presence among offshore catering section workers

    Directory of Open Access Journals (Sweden)

    Krohne Kariann

    2011-03-01

    Full Text Available Abstract Background To identify and explore the factors promoting sickness presenteeism among offshore catering section workers. Methods Twenty men and women, working in the offshore catering section onboard three offshore oil and gas production platforms on the Norwegian Continental Shelf, participated in three focus groups. Data from the focus groups were analysed according to a phenomenological approach, and supported by theories on presenteeism. Results The results show that the decision to attend work despite illness, first and foremost, was based on the severity of the health complaint. Other factors identified were; the individual's location once the health complaint occurred, job satisfaction, the norms of the team, and experiences of how company policies on sickness absenteeism were implemented by the catering section leaders. Conclusions Offshore working conditions may promote sickness presenteeism. The factors promoting sickness presenteeism onboard the platforms reflected experiences of a healthy work environment.

  5. [Temporal Analysis of Body Sway during Reciprocator Motion Movie Viewing].

    Science.gov (United States)

    Sugiura, Akihiro; Tanaka, Kunihiko; Wakatabe, Shun; Matsumoto, Chika; Miyao, Masaru

    2016-01-01

    We aimed to investigate the effect of stereoscopic viewing and the degree of awareness of motion sickness on posture by measuring body sway during motion movie viewing. Nineteen students (12 men and 7 women; age range, 21-24 years) participated in this study. The movie, which showed several balls randomly positioned, was projected on a white wall 2 m in front of the subjects through a two-dimensional (2-D)/three-dimensional (3-D) convertible projector. To measure body sway during movie viewing, the subjects stood statically erect on a Wii balance board, with the toe opening at 18 degrees. The study protocol was as follows: The subjects watched (1) a nonmoving movie for 1 minute as the pretest and then (2) a round-trip sinusoidally moving-in-depth-direction movie for 3 minutes. (3) The initial static movie was shown again for 1 minute. Steps (2) and (3) were treated as one trial, after which two trials (2-D and 3-D movies) were performed in a random sequence. In this study, we found that posture changed according to the motion in the movie and that the longer the viewing time, the higher the synchronization accuracy. These tendencies depended on the level of awareness of motion sickness or the 3-D movie viewed. The mechanism of postural change in movie viewing was not vection but self-defense to resolve sensory conflict between visual information (spatial swing) and equilibrium sense (motionlessness).

  6. A Kink that Makes you Sick: the Effect of Sick Pay on Absence in a Social Insurance System

    OpenAIRE

    Petri Bockerman; Ohto Kanninen; Ilpo Suoniemi

    2014-01-01

    We examine the effect of the replacement rule of a social insurance system on sickness absence. The elasticity of absence with respect to the benefit level is a critical parameter in defining the optimal sickness insurance scheme. A pre-determined, piecewise linear policy rule in which the replacement rate is determined by past earnings allows identification of the causal effect using a regression kink design. Using a large administrative dataset, we find a substantial and robust behavioral r...

  7. Diagnosis and treatment for sick building; Diagnostico y tratamiento para edificios saludables

    Energy Technology Data Exchange (ETDEWEB)

    Perez, Maria M; Salomon, Jorge A; Lazcano, Alejandro S [Facultad de Ingenieria UADY, Merida Yucatan (Mexico)

    2000-07-01

    In recent years, the indoor air quality (IAQ) in work spaces have acquired special importance. Health symptoms refer to a productivity and economic loss. IAQ health symptoms associated with acute discomfort that improve while away from work. More common, however, are apparent outbreaks of illness within work spaces in which neither environmental causes non recognized diseases can be identified. Usually reported within the last years, these events are often called sick building syndrome. To determine a sick building diagnosis and treatment, it is necessary to plan methodology based on environment comfort, habitability, energy efficiency use and nature preservation. Hereby it is presented a methodology to determine a sick building diagnosis and treatment which was applied in Superior Court of Justice building (Tribunales Primero y Segundo del Decimocuarto Circuito del Poder Judicial de la Federacion), where employees have expressed diseases as sleepiness, cold and difficulty breathing. [Spanish] En los ultimos anos, la calidad del aire en el ambiente de trabajo ha adquirido especial interes debido a la importancia que representa para el bienestar, eficiencia y productividad de los empleados. Los edificios carentes de esa calidad del aire ocasionan trastornos de salud relacionados con la falta de confort que prevalece en el ambiente de trabajo, es comun encontrar en los empleados que alli laboran, brotes de sintomas como dolores de cabeza, letargo y resfriados, entre otros. Usualmente encontrados en los ultimos anos en ambientes de oficinas a estos sintomas se les llama sindrome del edificio enfermo. Para lograr el diagnostico y tratamiento de un edificio enfermo es necesario plantear una metodologia basada en criterios de confort ambiental, habitabilidad, uso eficiente de la energia y preservacion del medio ambiente. En este trabajo presentamos una metodologia para el diagnostico y tratamiento de edificios con ese sindrome y presentamos un estudio de casos de los

  8. Do work-place initiated measures reduce sickness absence? Preventive measures and sickness absence among older workers in Norway.

    Science.gov (United States)

    Midtsundstad, Tove I; Nielsen, Roy A

    2014-03-01

    The article examines whether preventive measures and work adjustments at the establishment level affects sickness absence among workers aged 50 years and older. We combine survey data from a representative sample of 713 Norwegian companies, mapping the prevalence of preventive health measures in the work place in 2005, with register data on sickness absence and demographic variables for workers aged 50 years or older in 2001 and 2007. By means of a difference-in-differences approach, we compare changes and differences in the likelihood of sickness absence among the sample group, with and without the various measures/ instruments in 2005 respectively. In general, work-place preventive measures at the establishment level have not contributed to reducing the probability for sickness absence among workers aged 50 years and older. However, analyses comparing differences between industries find that the work-place measures have had a positive effect on public administration employees. Whether work-place preventive initiatives influence levels of sickness absence seems to be contingent on sector and industry. Therefore, work-place measures may be more effective in the public administration sector where most employees have office jobs compared to sectors such as manufacturing, construction and transportation, where many employees have manual work and more physical demanding jobs. Work-place initiatives thus seem to have less effect on preventing sickness absence in sectors dominated by manual labour.

  9. Human factors and nuclear space technology in long-term exploration

    International Nuclear Information System (INIS)

    Brown-VanHoozer, S.A.; VanHoozer, W.R.

    2000-01-01

    Allocation of manual versus automated tasks for operation and maintenance of nuclear power systems in space will be crucial at the onset and at the return of a space flight. Such factors as space adaptation syndrome (SAS), a temporary space motion sickness that has affected 40 to 50% of crew members on past space flights, can result in lost effort ranging from a few hours to a full day. This could have a significant impact on manual performance where high levels of execution are likely to be required in the very early stages of the mission. Other considerations involving higher-level behavioral phenomena such as interpersonal and group processes, individual belief systems, social and motivational factors, and (subjective) cognitive function have received little attention; nevertheless these will be essential elements for success in long-term exploration. Understanding that long-term space flight missions may create groups that become unique societies distinct unto themselves will test current ethical, moral, and social belief systems, requiring one to examine the amalgamation as well as organizational structures for the safety and balance of the crew

  10. Sick building syndrome - results of the 'Proklima' research project; Befindlichkeitsstoerungen in Buerogebaeuden - Ergebnisse aus dem Proklima Forschungsprojekt

    Energy Technology Data Exchange (ETDEWEB)

    Kruppa, B. [Bundesindustrieverband Heizungs-, Klima-, Sanitaertechnik und Technische Gebaeudesysteme e.V., Bonn (Germany); Bischof, W.; Brasche, S. [Arbeitsgruppe Raumklimatologie der FSU Jena (ARK), Erfurt (Germany); Bullinger-Naber, M. [Hamburg Univ. (Germany). Abt. fuer Medizinische Psychologie; Mayer, E. [Fraunhofer-Institut fuer Bauphysik, Holzkirchen (Germany); Gebhardt, H. [Wuppertal Univ. (Gesamthochschule) (Germany). Inst. fuer Arbeitsmedizin, Sicherheitstechnik und Ergonomie

    2000-07-01

    In the world's biggest research project, the sick building syndrome was investigated in Germany between 1995 and 1999. In all, 8 air-conditioned buildings and 6 non-air-conditioned buildings, 40 space HVAC systems and 1497 places of work were analyzed, and 4,500 persons were asked to provide data. For the first time ever, measured physical, biological and chemical data were compared with the subjective data provided by the inquiry forms. It was found that the concentrations and hygienic status of air conditioning systems do have an effect on subjective comfort. Buildings with well-designed and well-serviced space HVAC systems had better results than buildings without air conditioning systems. However, it is the psychosocial environment and the job description of building inhabitants that decide their response in terms of sick building syndrome. Factors like gender, job satisfaction, job specifications and educational level are more important than space HVAC systems. [German] Im Rahmen eines der weltweit groessten Forschungsprojekte zum Thema 'Sick Building Syndrome' wurden in Deutschland zwischen 1995 und 1999 umfangreiche Untersuchungen durchgefuehrt mit dem Ziel, die Ursachen und Folgen von Befindlichkeitsstoerungen in Buerogebaeuden zu ermitteln. Insgesamt wurden 8 klimatisierte und 6 nicht klimatisierte Gebaeude, 40 raumlufttechnische Anlagen und 1497 Arbeitsplaetze untersucht sowie ueber 4.500 Personen befragt. Die Ergebnisse erlauben zum ersten Mal einen direkten Vergleich der gemessenen physikalischen, biologischen und chemischen Werte mit den subjektiven Angaben (Fragebogendaten) an klimatisierten und nicht klimatisierten Arbeitsplaetzen. Die Auswertung zeigt, dass die Konzentration der Anlagen und deren hygienischer Wartungszustand einen Einfluss auf die Befindlichkeit der Mitarbeiter haben. Gebaeude mit gut geplanten und gewarteten RLT-Anlagen schneiden in der Bewertung sogar besser ab als nicht klimatisierte Gebaeude. Die groessten

  11. Part-time sick leave as a treatment method for individuals with musculoskeletal disorders.

    Science.gov (United States)

    Andrén, Daniela; Svensson, Mikael

    2012-09-01

    There is increasing evidence that staying active is an important part of a recovery process for individuals on sick leave due to musculoskeletal disorders (MSDs). It has been suggested that using part-time sick-leave rather than full-time sick leave will enhance the possibility of full recovery to the workforce, and several countries actively favor this policy. The aim of this paper is to examine if it is beneficial for individuals on sick leave due to MSDs to be on part-time sick leave compared to full-time sick leave. A sample of 1,170 employees from the RFV-LS (register) database of the Social Insurance Agency of Sweden is used. The effect of being on part-time sick leave compared to full-time sick leave is estimated for the probability of returning to work with full recovery of lost work capacity. A two-stage recursive bivariate probit model is used to deal with the endogeneity problem. The results indicate that employees assigned to part-time sick leave do recover to full work capacity with a higher probability than those assigned to full-time sick leave. The average treatment effect of part-time sick leave is 25 percentage points. Considering that part-time sick leave may also be less expensive than assigning individuals to full-time sick leave, this would imply efficiency improvements from assigning individuals, when possible, to part-time sick leave.

  12. Software for Project-Based Learning of Robot Motion Planning

    Science.gov (United States)

    Moll, Mark; Bordeaux, Janice; Kavraki, Lydia E.

    2013-01-01

    Motion planning is a core problem in robotics concerned with finding feasible paths for a given robot. Motion planning algorithms perform a search in the high-dimensional continuous space of robot configurations and exemplify many of the core algorithmic concepts of search algorithms and associated data structures. Motion planning algorithms can…

  13. Articulated Human Motion Tracking Using Sequential Immune Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Yi Li

    2013-01-01

    Full Text Available We formulate human motion tracking as a high-dimensional constrained optimization problem. A novel generative method is proposed for human motion tracking in the framework of evolutionary computation. The main contribution is that we introduce immune genetic algorithm (IGA for pose optimization in latent space of human motion. Firstly, we perform human motion analysis in the learnt latent space of human motion. As the latent space is low dimensional and contents the prior knowledge of human motion, it makes pose analysis more efficient and accurate. Then, in the search strategy, we apply IGA for pose optimization. Compared with genetic algorithm and other evolutionary methods, its main advantage is the ability to use the prior knowledge of human motion. We design an IGA-based method to estimate human pose from static images for initialization of motion tracking. And we propose a sequential IGA (S-IGA algorithm for motion tracking by incorporating the temporal continuity information into the traditional IGA. Experimental results on different videos of different motion types show that our IGA-based pose estimation method can be used for initialization of motion tracking. The S-IGA-based motion tracking method can achieve accurate and stable tracking of 3D human motion.

  14. Severe occupational hand eczema, job stress and cumulative sickness absence.

    Science.gov (United States)

    Böhm, D; Stock Gissendanner, S; Finkeldey, F; John, S M; Werfel, T; Diepgen, T L; Breuer, K

    2014-10-01

    Stress is known to activate or exacerbate dermatoses, but the relationships between chronic stress, job-related stress and sickness absence among occupational hand eczema (OHE) patients are inadequately understood. To see whether chronic stress or burnout symptoms were associated with cumulative sickness absence in patients with OHE and to determine which factors predicted sickness absence in a model including measures of job-related and chronic stress. We investigated correlations of these factors in employed adult inpatients with a history of sickness absence due to OHE in a retrospective cross-sectional explorative study, which assessed chronic stress (Trier Inventory for the Assessment of Chronic Stress), burnout (Shirom Melamed Burnout Measure), clinical symptom severity (Osnabrück Hand Eczema Severity Index), perceived symptom severity, demographic characteristics and cumulative days of sickness absence. The study group consisted of 122 patients. OHE symptoms were not more severe among patients experiencing greater stress and burnout. Women reported higher levels of chronic stress on some measures. Cumulative days of sickness absence correlated with individual dimensions of job-related stress and, in multiple regression analysis, with an overall measure of chronic stress. Chronic stress is an additional factor predicting cumulative sickness absence among severely affected OHE patients. Other relevant factors for this study sample included the 'cognitive weariness' subscale of the Shirom Melamed Burnout Measure and the physical component summary score of the SF-36, a measure of health-related life quality. Prevention and rehabilitation should take job stress into consideration in multidisciplinary treatment strategies for severely affected OHE patients. © The Author 2014. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. Blind retrospective motion correction of MR images.

    Science.gov (United States)

    Loktyushin, Alexander; Nickisch, Hannes; Pohmann, Rolf; Schölkopf, Bernhard

    2013-12-01

    Subject motion can severely degrade MR images. A retrospective motion correction algorithm, Gradient-based motion correction, which significantly reduces ghosting and blurring artifacts due to subject motion was proposed. The technique uses the raw data of standard imaging sequences; no sequence modifications or additional equipment such as tracking devices are required. Rigid motion is assumed. The approach iteratively searches for the motion trajectory yielding the sharpest image as measured by the entropy of spatial gradients. The vast space of motion parameters is efficiently explored by gradient-based optimization with a convergence guarantee. The method has been evaluated on both synthetic and real data in two and three dimensions using standard imaging techniques. MR images are consistently improved over different kinds of motion trajectories. Using a graphics processing unit implementation, computation times are in the order of a few minutes for a full three-dimensional volume. The presented technique can be an alternative or a complement to prospective motion correction methods and is able to improve images with strong motion artifacts from standard imaging sequences without requiring additional data. Copyright © 2013 Wiley Periodicals, Inc., a Wiley company.

  16. Motion in radiotherapy

    DEFF Research Database (Denmark)

    Korreman, Stine Sofia

    2012-01-01

    This review considers the management of motion in photon radiation therapy. An overview is given of magnitudes and variability of motion of various structures and organs, and how the motion affects images by producing artifacts and blurring. Imaging of motion is described, including 4DCT and 4DPE...

  17. Breast feeding a sick child; can social media influence practice?

    Science.gov (United States)

    Mylod, Dominique

    2015-06-01

    Breast milk represents optimum infant nutrition. The World Health Organization's recommendation that babies should be exclusively breastfed for a minimum of 6 months (Kramer & Kakuma, 2001) remains unchanged in its second decade (Kramer & Kakuma, 2014), which is acknowledged in industrialized countries by successive policies and guidelines for the promotion and care of breastfeeding in children's wards and departments. The known protective influence of breast milk in preventing the onset of disease in later life is of particular import for any sick infant, but the user voice as represented by Helen Calvert's Twitter campaign @heartmummy#hospitalbreastfeeding has united service user and professional voices to call for improved breastfeeding support in pediatric care. Although breastfeeding rates in industrialized countries drop markedly in the first 6 weeks, breastfed babies with cardiac conditions benefit from better oxygen saturations, faster weight gain, and shorter hospital stays. Unwell babies are most in need of the benefits of breast milk. However, families and staff overcome physical barriers to the initiation and maintenance of breastfeeding, including lack of space, privacy, and separation of the maternal-infant dyad. Many women are motivated to breastfeed or express milk but are reluctant to approach health professionals for help and advice. Despite robust evidence and sound guidelines and policies, breastfeeding knowledge and experience amongst Child Health professionals is often inadequate and leaves them unable to support families. While @heartmummy#hospitalbreastfeeding highlights the issue, Child Health strategy needs investment in young people's long term health by increasing staff skills and focusing on breastfeeding as a core therapeutic intervention. Lactation Consultants could offer training, disseminate good practice, and address the needs of breastfeeding families.

  18. The Mars Project: Avoiding Decompression Sickness on a Distant Planet

    Science.gov (United States)

    Conkin, Johnny

    2000-05-01

    A cost-effective approach for Mars exploration is to use available resources, such as water and atmospheric gases. Nitrogen (N2) and argon (Ar) are available and could form the inert gas component of a habitat atmosphere at 8.0, 9.0, or 10.0 pounds per square inch (psia). The habitat and space suit are designed as an integrated system: a comfortable living environment about 85% of the time and a safe working environment about 15% of the time. A goal is to provide a system that permits unrestricted exploration of Mars, but the risk of decompression sickness (DCS) during the extravehicular activity in a 3.75-psia suit, after exposure to any of the three habitat conditions, may limit unrestricted exploration. I evaluate here the risk of DCS since a significant proportion of a trinary breathing gas in the habitat might contain Ar. I draw on past experience and published information to extrapolate into untested, multivariable conditions to evaluate risk. A rigorous assessment of risk as a probability of DCS for each habitat condition is not yet possible. Based on many assumptions about Ar in hypobaric decompressions, I conclude that the presence of Ar significantly increases the risk of DCS. The risk is significant even with the best habitat option: 2.56 psia oxygen, 3.41 psia N2, and 2.20 psia Ar. Several hours of prebreathing 100% 02, a higher suit pressure, or a combination of other important variables such as limited exposure time on the surface or exercise during prebreathe would be necessary to reduce the risk of DCS to an acceptable level. The acceptable level for DCS risk on Mars has not yet been determined. Mars is a great distance from Earth and therefore from primary medical care. The acceptable risk would necessarily be defined by the capability to treat DCS in the Rover vehicle, in the habitat, or both.

  19. Sickness presenteeism in Norway and Sweden

    Directory of Open Access Journals (Sweden)

    Vegard Johansen

    2013-01-01

    Full Text Available Introduction: Sickness presenteeism (SP refers to the practice of going to work despite illness. This article describes the distribution of SP in Norway and Sweden. It also discusses relations between SP and various work characteristics and personal factors in the two countries. Methods: More than 2500 Norwegian and Swedish workers between 20 and 60 years of age answered a postal questionnaire. The Norwegian and Swedish samples are weighed and representative with regard to both variables of regional background and demography, but the response rate was low. The distribution of SP is measured by frequency (episodes in the previous year and by length (total days of SP in the previous year. This study employed binary and multinomial logistic regression to detect which factors influence the frequency of SP. Results: Fifty-five per cent of the respondents in Norway and Sweden practised SP in the previous year. The frequency of SP episodes is similar in the two countries. Further, respondents with low/medium income, physical work, and managerial responsibilities report SP more often in both countries. Non-western immigrants, the less educated, and those employed by others are overrepresented with SP in Norway. Neither gender nor age had any particular influence. Discussion: In accordance with previous studies, this study among Norwegian and Swedish workers suggests that some SP during a working year may be more common than no SP. Our analyses of determinants of SP present some previously undocumented differences. Divisions between sedentary versus physical work and management versus non-management were important for SP in Norway and Sweden. Moreover, non-western immigrants are overrepresented with SP in Norway, but this pattern does not prevail in Sweden. Some possible causes for non-western immigrants to report more SP are suggested in the article, but we need more research to follow up on the missing correlation between ethnic background and SP in

  20. The probability and severity of decompression sickness

    Science.gov (United States)

    Hada, Ethan A.; Vann, Richard D.; Denoble, Petar J.

    2017-01-01

    Decompression sickness (DCS), which is caused by inert gas bubbles in tissues, is an injury of concern for scuba divers, compressed air workers, astronauts, and aviators. Case reports for 3322 air and N2-O2 dives, resulting in 190 DCS events, were retrospectively analyzed and the outcomes were scored as (1) serious neurological, (2) cardiopulmonary, (3) mild neurological, (4) pain, (5) lymphatic or skin, and (6) constitutional or nonspecific manifestations. Following standard U.S. Navy medical definitions, the data were grouped into mild—Type I (manifestations 4–6)–and serious–Type II (manifestations 1–3). Additionally, we considered an alternative grouping of mild–Type A (manifestations 3–6)–and serious–Type B (manifestations 1 and 2). The current U.S. Navy guidance allows for a 2% probability of mild DCS and a 0.1% probability of serious DCS. We developed a hierarchical trinomial (3-state) probabilistic DCS model that simultaneously predicts the probability of mild and serious DCS given a dive exposure. Both the Type I/II and Type A/B discriminations of mild and serious DCS resulted in a highly significant (p probability of ‘mild’ DCS resulted in a longer allowable bottom time for the same 2% limit. However, for the 0.1% serious DCS limit, we found a vastly decreased allowable bottom dive time for all dive depths. If the Type A/B scoring was assigned to outcome severity, the no decompression limits (NDL) for air dives were still controlled by the acceptable serious DCS risk limit rather than the acceptable mild DCS risk limit. However, in this case, longer NDL limits were allowed than with the Type I/II scoring. The trinomial model mild and serious probabilities agree reasonably well with the current air NDL only with the Type A/B scoring and when 0.2% risk of serious DCS is allowed. PMID:28296928

  1. Does self-efficacy predict return-to-work after sickness absence? A prospective study among 930 employees with sickness absence for three weeks or more

    DEFF Research Database (Denmark)

    Labriola, Merete; Lund, Thomas; Christensen, Karl B

    2007-01-01

    follows a cohort of 5357 working employees and 106 long-term sickness absent employees in Denmark. They were interviewed in 2000 regarding self-efficacy and various co-variates, and followed for 78 weeks in a national sickness absence register. Cox regression analysis was performed in order to assess...... or with Return-to-Work. CONCLUSION: The results may suggest that lower self-efficacy among employees with sickness absence is a result of the sickness absence itself rather than a precursor of it. This indicates a need to investigate the potential change in self-efficacy in relation to the employee's change......AIM: To compare levels of self-efficacy among the general working population and employees with sickness absence from work, and to examine if general self-efficacy measured before occurrence of sickness absence predicted subsequent onset of sickness absence and Return-to-Work. METHODS: The study...

  2. Sickness absence among health workers in belo horizonte, brazil.

    Science.gov (United States)

    Bassi, Iara; Assunção, Ada Ávila; Pimenta, Adriano Marçal; Benavides, Fernando G; Ubalde-Lopez, Monica

    2016-05-25

    To describe the prevalence of sickness absence and to analyze factors associated with the outcome according to gender in a sample of healthcare workers at the Belo Horizonte Health Department. This study was based on a Belo Horizonte Health Department survey carried out between September 2008 and January 2009. From a randomly selected sample of 2,205 workers, 1,808 agreed to participate. Workers were classified into Health Staff or Health Care. Other explanatory variables were social and demographic data, work characteristics, and personal health. The Poisson regression was applied to analyze factors associated with sickness absence by the prevalence ratio (PR). The overall prevalence of sickness absence was 31.5% (23.8% for men and 34.6% for women). In the final model, we found higher rates of sickness absence in both male and female workers involved in tasks with high psychosocial demands (PR=1.86 men; PR=1.38 women) and in those that reported using medication for treating chronic diseases (PR=1.96 men; PR=1.50 women). Women having a permanent job contract had a higher prevalence of sickness absence than those having a temporary job contract (PR=1.71). Our findings suggest a paradox in how healthcare is organized: good results in terms of its global objective of providing healthcare for citizens contrast with lack of effective measures for protecting healthcare workers.

  3. SICKNESS PRESENCE AND STRESSFUL LIFE EVENTS OF HEALTH CARE WORKERS.

    Science.gov (United States)

    Škerjanc, Alenka; Fikfak, Metoda Dodič

    2015-09-01

    The aim of the study is to investigate the relationship between sickness presence and stressful life events among health care workers. Data were gathered from all health care workers at the University Medical Centre Ljubljana employed there in the period between 1 January 2010 and 31 December 2010. Each employee obtained a questionnaire composed of two standardized international questionnaires. There were 57% of sickness present health care workers among the participants. The sickness present reported to have more diseases of family member than the non-sickness present (OR = 1.5; 95% CI = 1.2-2.0), loan (OR = 1.4; 95% CI = 1.1-1.6), their partner lost job (OR = 1.4; 95% CI = 1.0-1.8), or they changed the place of living (OR = 1.4; 95% CI = 1.0-2.0). The results of the study indicate that stressful life events with economic consequences might have an important influence on sickness presence.

  4. Nuclear friction and chaotic motion

    International Nuclear Information System (INIS)

    Srokowski, T.; Szczurek, A.; Drozdz, S.

    1990-01-01

    The concept of nuclear friction is considered from the point of view of regular versus chaotic motion in an atomic nucleus. Using a realistic nuclear Hamiltonian it is explicitly shown that the frictional description of the gross features of nuclear collisions is adequate if the system behaves chaotically. Because of the core in the Hamiltonian, the three-body nuclear system already reveals a structure of the phase space rich enough for this concept to be applicable

  5. Motion Transplantation Techniques: A Survey

    NARCIS (Netherlands)

    van Basten, Ben; Egges, Arjan

    2012-01-01

    During the past decade, researchers have developed several techniques for transplanting motions. These techniques transplant a partial auxiliary motion, possibly defined for a small set of degrees of freedom, on a base motion. Motion transplantation improves motion databases' expressiveness and

  6. Sickness absence at a young age and later sickness absence, disability pension, death, unemployment and income in native Swedes and immigrants

    Science.gov (United States)

    Johansson, Bo; Nordqvist, Tobias; Lundberg, Ingvar; Vingård, Eva

    2015-01-01

    Background: Sickness absence with cash benefits from the sickness insurance gives an opportunity to be relieved from work without losing financial security. There are, however, downsides to taking sickness absence. Periods of sickness absence, even short ones, can increase the risk for future spells of sickness absence and unemployment. The sickness period may in itself have a detrimental effect on health. The aim of the study was to investigate if there is an association between exposure to sickness absence at a young age and later sickness absence, disability pension, death, unemployment and income from work. Methods: Our cohort consisted of all immigrants aged 21–25 years in Sweden in 1993 (N = 38 207) and a control group of native Swedes in the same age group (N = 225 977). We measured exposure to sickness absence in 1993 with a follow-up period of 15 years. We conducted separate analyses for men and women, and for immigrants and native Swedes. Results: Exposure to ≥60 days of sickness absence in 1993 increased the risk of sickness absence [hazard ratio (HR) 1.6–11.4], unemployment (HR 1.1–1.2), disability pension (HR 1.2–5.3) and death (HR 1.2–3.5). The income from work, during the follow-up period, among individuals with spells of sick leave for ≥60 days in 1993 was around two-thirds of that of the working population who did not take sick leave. Conclusions: Individuals on sickness absence had an increased risk for work absence, death and lower future income. PMID:25634955

  7. Short-Term Solutions to Prevent Simulator-Induced Motion Sickness: Report of a Conference.

    Science.gov (United States)

    1986-03-01

    important thing for the human’s stability of closed loop. The gains and 4 magnitudes can be grossly off and he can compensate for that almost subconsciously ...that problem without going into the expense of reprogramming simulators or designing simulators that would give you relatively higher frequencies, I

  8. Efficacy of Intranasal Scopolamine Gel for Motion Sickness Treatment in Aviation Candidates

    Science.gov (United States)

    2009-04-13

    Baseline 15 25 80 115 145 190 M ea n B lo o d P re ss u re (m m H g ) 0 20 40 60 80 100 120 140 Systolic BP P Systolic BPIN Diastolic BPP Diastolic...scopolamine when compared to placebo, p < .05. BPP = Blood Pressure, Placebo, BPIN = Blood Pressure, Intranasal Scopolamine 31 Time (min) Baseline 15 25 80

  9. Motion Sickness When Driving With a Head-Slaved Camera System

    Science.gov (United States)

    2003-02-01

    YPR-765 under armour (Report TM-97-A026). Soesterberg, The Netherlands: TNO Human Factors Research Institute. Van Erp, J.B.F., Padmos, P. & Tenkink, E...Institute. Van Erp, J.B.F., Van den Dobbelsteen, J.J. & Padmos, P. (1998). Improved camera-monitor system for driving YPR-765 under armour (Report TM-98

  10. On equations of motion on complex grassman manifold

    International Nuclear Information System (INIS)

    Berceanu, S.; Gheorghe, A.

    1989-02-01

    We investigate the equations of motion on the 'classical' phase space which corresponds to quantum state space in the case of the complex Grassmann manifold appearing in the Hartree-Fock problem. First and second degree polynomial Hamiltonians in bifermion operators are considered. The 'classical' motion corresponding to linear Hamiltonians is described by a Matrix Riccati equation.(authors)

  11. Associations between partial sickness benefit and disability pensions: initial findings of a Finnish nationwide register study.

    Science.gov (United States)

    Kausto, Johanna; Virta, Lauri; Luukkonen, Ritva; Viikari-Juntura, Eira

    2010-06-23

    Timely return to work after longterm sickness absence and the increased use of flexible work arrangements together with partial health-related benefits are tools intended to increase participation in work life. Although partial sickness benefit and partial disability pension are used in many countries, prospective studies on their use are largely lacking. Partial sickness benefit was introduced in Finland in 2007. This register study aimed to investigate the use of health-related benefits by subjects with prolonged sickness absence, initially on either partial or full sick leave. Representative population data (13 375 men and 16 052 women either on partial or full sick leave in 2007) were drawn from national registers and followed over an average of 18 months. The registers provided information on the study outcomes: diagnoses and days of payment for compensated sick leaves, and the occurrence of disability pension. Survival analysis and multinomial regression were carried out using sociodemographic variables and prior sickness absence as covariates. Approximately 60% of subjects on partial sick leave and 30% of those on full sick leave had at least one recurrent sick leave over the follow up. A larger proportion of those on partial sick leave (16%) compared to those on full sick leave (1%) had their first recurrent sick leave during the first month of follow up. The adjusted risks of the first recurrent sick leave were 1.8 and 1.7 for men and women, respectively, when subjects on partial sick leave were compared with those on full sick leave. There was no increased risk when those with their first recurrent sick leave in the first month were excluded from the analyses. The risks of a full disability pension were smaller and risks of a partial disability pension approximately two-fold among men and women initially on partial sick leave, compared to subjects on full sick leave. This is the first follow up study of the newly adopted partial sickness benefit in

  12. Associations between partial sickness benefit and disability pensions: initial findings of a Finnish nationwide register study

    Directory of Open Access Journals (Sweden)

    Luukkonen Ritva

    2010-06-01

    Full Text Available Abstract Background Timely return to work after longterm sickness absence and the increased use of flexible work arrangements together with partial health-related benefits are tools intended to increase participation in work life. Although partial sickness benefit and partial disability pension are used in many countries, prospective studies on their use are largely lacking. Partial sickness benefit was introduced in Finland in 2007. This register study aimed to investigate the use of health-related benefits by subjects with prolonged sickness absence, initially on either partial or full sick leave. Methods Representative population data (13 375 men and 16 052 women either on partial or full sick leave in 2007 were drawn from national registers and followed over an average of 18 months. The registers provided information on the study outcomes: diagnoses and days of payment for compensated sick leaves, and the occurrence of disability pension. Survival analysis and multinomial regression were carried out using sociodemographic variables and prior sickness absence as covariates. Results Approximately 60% of subjects on partial sick leave and 30% of those on full sick leave had at least one recurrent sick leave over the follow up. A larger proportion of those on partial sick leave (16% compared to those on full sick leave (1% had their first recurrent sick leave during the first month of follow up. The adjusted risks of the first recurrent sick leave were 1.8 and 1.7 for men and women, respectively, when subjects on partial sick leave were compared with those on full sick leave. There was no increased risk when those with their first recurrent sick leave in the first month were excluded from the analyses. The risks of a full disability pension were smaller and risks of a partial disability pension approximately two-fold among men and women initially on partial sick leave, compared to subjects on full sick leave. Conclusions This is the first follow

  13. Use of Virtual Reality for Space Flight

    Science.gov (United States)

    Harm, Deborah; Taylor, L. C.; Reschke, M. F.

    2011-01-01

    Virtual environments offer unique training opportunities, particularly for training astronauts and preadapting them to the novel sensory conditions of microgravity. Two unresolved human factors issues in virtual reality (VR) systems are: 1) potential "cybersickness", and 2) maladaptive sensorimotor performance following exposure to VR systems. Interestingly, these aftereffects are often quite similar to adaptive sensorimotor responses observed in astronauts during and/or following space flight. Active exploratory behavior in a new environment, with resulting feedback and the formation of new associations between sensory inputs and response outputs, promotes appropriate perception and motor control in the new environment. Thus, people adapt to consistent, sustained alterations of sensory input such as those produced by microgravity. Our research examining the effects of repeated exposures to a full field of view dome VR system showed that motion sickness and initial decrements in eye movement and postural control were greatly diminished following three exposures. These results suggest that repeated transitions between VR and the normal environment preflight might be a useful countermeasure for neurosensory and sensorimotor effects of space flight. The range of VR applications is enormous, extending from ground-based VR training for extravehicular activities at NASA, to medical and educational uses. It seems reasonable to suggest that other space related uses of VR should be investigated. For example, 1) use of head-mounted VR on orbit to rehearse/practice upcoming operational activities, and 2) ground-based VR training for emergency egress procedures. We propose that by combining VR designed for operational activities preflight, along with an appropriate schedule to facilitate sensorimotor adaptation and improve spatial orientation would potentially accomplish two important goals for astronauts and cosmonauts, preflight sensorimotor adaption and enhanced operational

  14. Reducing sick leave of Dutch vocational school students: adaptation of a sick leave protocol using the intervention mapping process.

    Science.gov (United States)

    de Kroon, Marlou L A; Bulthuis, Jozien; Mulder, Wico; Schaafsma, Frederieke G; Anema, Johannes R

    2016-12-01

    Since the extent of sick leave and the problems of vocational school students are relatively large, we aimed to tailor a sick leave protocol at Dutch lower secondary education schools to the particular context of vocational schools. Four steps of the iterative process of Intervention Mapping (IM) to adapt this protocol were carried out: (1) performing a needs assessment and defining a program objective, (2) determining the performance and change objectives, (3) identifying theory-based methods and practical strategies and (4) developing a program plan. Interviews with students using structured questionnaires, in-depth interviews with relevant stakeholders, a literature research and, finally, a pilot implementation were carried out. A sick leave protocol was developed that was feasible and acceptable for all stakeholders. The main barriers for widespread implementation are time constraints in both monitoring and acting upon sick leave by school and youth health care. The iterative process of IM has shown its merits in the adaptation of the manual 'A quick return to school is much better' to a sick leave protocol for vocational school students.

  15. MRI diagnosis of acute spinal cord decompression sickness

    International Nuclear Information System (INIS)

    Tang Xiaofeng; Yuan Fengmei; Ma Heng; Xu Yongzhong; Gai Qingzhu; Wang Ying

    2008-01-01

    Objective: To describe MRI findings of acute spinal cord decompression sickness. Methods: MRI findings of 5 cases with clinical definite acute spinal cord decompression sickness were retrospectively analyzed. The main clinical informations included underwater performance history against regulations, short-term complete or incomplete spinal cord injury symptoms after fast going out of water, sensory disability and urinary and fecal incontinence, etc. Results: Spinal cord vacuole sign was found in all 5 cases. Iso-signal intensity (n=3), high signal intensity (n=1), and low signal intensity (n=1) was demonstrated on T 1 WI, and high signal intensity (n=5) was found on T 2 WI. Owl eye sign was detected in 3 cases, and lacune foci were seen in 2 cases. Conclusion: MRI findings of acute spinal cord decompression sickness had some characteristics, and it was easy to diagnose by combining diving history with clinical manifestations. (authors)

  16. Multidimensional intervention and sickness absence in assistant nursing students

    DEFF Research Database (Denmark)

    Svensson, Annemarie Lyng; Strøyer, Jesper; Ebbehøj, Niels Erik

    2009-01-01

    BACKGROUND: When handling patients, nursing assistant (NA) students and nurse students are frequently exposed to risk factors for low back pain (LBP) including sudden loads and twisting and bending of the spine. Furthermore, LBP is a major cause of sickness absence. AIMS: To ascertain...... if a multidimensional prevention programme combining physical training, patient transfer technique and stress management prevents sickness absence and LBP in NA students. METHODS: The study was a 14-month cluster randomized controlled study. The participants were NA students from 37 randomly selected classes located...... at two schools of health and social care in Copenhagen, Denmark. The participants completed a comprehensive questionnaire regarding sickness absence, LBP and psychosocial factors on commencement and after completion of the study. RESULTS: Of 766 female NA students, 668 (87%) completed the baseline...

  17. Can walking motions improve visually induced rotational self-motion illusions in virtual reality?

    Science.gov (United States)

    Riecke, Bernhard E; Freiberg, Jacob B; Grechkin, Timofey Y

    2015-02-04

    Illusions of self-motion (vection) can provide compelling sensations of moving through virtual environments without the need for complex motion simulators or large tracked physical walking spaces. Here we explore the interaction between biomechanical cues (stepping along a rotating circular treadmill) and visual cues (viewing simulated self-rotation) for providing stationary users a compelling sensation of rotational self-motion (circular vection). When tested individually, biomechanical and visual cues were similarly effective in eliciting self-motion illusions. However, in combination they yielded significantly more intense self-motion illusions. These findings provide the first compelling evidence that walking motions can be used to significantly enhance visually induced rotational self-motion perception in virtual environments (and vice versa) without having to provide for physical self-motion or motion platforms. This is noteworthy, as linear treadmills have been found to actually impair visually induced translational self-motion perception (Ash, Palmisano, Apthorp, & Allison, 2013). Given the predominant focus on linear walking interfaces for virtual-reality locomotion, our findings suggest that investigating circular and curvilinear walking interfaces offers a promising direction for future research and development and can help to enhance self-motion illusions, presence and immersion in virtual-reality systems. © 2015 ARVO.

  18. Modeling repetitive motions using structured light.

    Science.gov (United States)

    Xu, Yi; Aliaga, Daniel G

    2010-01-01

    Obtaining models of dynamic 3D objects is an important part of content generation for computer graphics. Numerous methods have been extended from static scenarios to model dynamic scenes. If the states or poses of the dynamic object repeat often during a sequence (but not necessarily periodically), we call such a repetitive motion. There are many objects, such as toys, machines, and humans, undergoing repetitive motions. Our key observation is that when a motion-state repeats, we can sample the scene under the same motion state again but using a different set of parameters; thus, providing more information of each motion state. This enables robustly acquiring dense 3D information difficult for objects with repetitive motions using only simple hardware. After the motion sequence, we group temporally disjoint observations of the same motion state together and produce a smooth space-time reconstruction of the scene. Effectively, the dynamic scene modeling problem is converted to a series of static scene reconstructions, which are easier to tackle. The varying sampling parameters can be, for example, structured-light patterns, illumination directions, and viewpoints resulting in different modeling techniques. Based on this observation, we present an image-based motion-state framework and demonstrate our paradigm using either a synchronized or an unsynchronized structured-light acquisition method.

  19. Measures of work-family conflict predict sickness absence from work.

    Science.gov (United States)

    Clays, Els; Kittel, France; Godin, Isabelle; Bacquer, Dirk De; Backer, Guy De

    2009-08-01

    To examine the relation between work-family conflict and sickness absence. The BELSTRESS III study comprised 2983 middle-aged workers. Strain-based work-home interference (WHI) and home-work interference (HWI) were assessed by means of self-administered questionnaires. Prospective data of registered sickness absence during 12-months follow-up were collected. Multiple logistic regression analysis was conducted. HWI was positively and significantly related to high sickness absence duration (at least 10 sick leave days) and high sickness absence frequency (at least 3 sick leave episodes) in men and women, also after adjustments were made for sociodemographic variables, health indicators, and environmental psychosocial factors. In multivariate analysis, no association between WHI and sickness absence was found. HWI was positively and significantly related to high sickness absence duration and frequency during 12-months follow-up in male and female workers.

  20. The effect of part-time sick leave for employees with mental disorders

    DEFF Research Database (Denmark)

    Høgelund, Jan; Holm, Anders

    reduces the duration until employees with mental disorders end their sick leave by reporting ready for returning to regular working hours. The programme allows fully sick-listed employees to resume work at reduced hours. When the sick-listed employee’s health improves, working hours are increased until...... the employee is able to work regular hours. We use combined survey and register data about 226 long-term sick-listed employees with mental disorders and 638 employees with physical disorders. Our analyses show that part-time sick-listing significantly reduces the duration until returning to regular working...... hours for employees with physical disorders. In contrast, we find that part-time sick-listing does not reduce durations for employees with mental disorders. The analyses also illustrate the importance of adjusting for unobserved differences between part-time sick-listed and full-time sick...

  1. Leadership styles of nurse managers and registered sickness absence among their nursing staff

    NARCIS (Netherlands)

    Schreuder, Jolanda A. H.; Roelen, Corne A. M.; van Zweeden, Nely F.; Jongsma, Dianne; van der Klink, Jac J. L.; Groothoff, Johan W.

    2011-01-01

    Background: Sickness absence leads to understaffing and interferes with nursing efficiency and quality. It has been reported in literature that managerial leadership is associated with self-reported sickness absence in the working population. Purposes: This study investigated the relationship

  2. Sleep disturbances and fatigue : independent predictors of sickness absence? A prospective study among 6538 employees

    NARCIS (Netherlands)

    Bultmann, Ute; Nielsen, Maj Britt D.; Madsen, Ida E. H.; Burr, Hermann; Rugulies, Reiner

    Background: Although sleep disturbances and fatigue are common conditions, frequently shown to be associated with sickness absence, only a few studies have prospectively investigated their independent effects on sickness absence, while adjusting for depressive symptoms. This study aims (i) to

  3. Is Sickness Presenteeism a Risk Factor for Depression?

    DEFF Research Database (Denmark)

    Conway, Paul Maurice; Hogh, Annie; Rugulies, Reiner Ernst

    2014-01-01

    was associated with an increased risk of depression among initially nondepressed participants (odds ratio, 2.45; 95% confidence interval, 1.06 to 5.64). No significant sex-related differences were observed in this relationship. CONCLUSION:: Adding to previous evidence on the health effects of SP, this study......OBJECTIVE:: To examine the prospective association between sickness presenteeism (SP), that is, working while ill, and the onset of depression. METHODS:: We carried out a two-wave (2006 to 2008) questionnaire-based study among 1271 employees from 60 Danish workplaces. Sickness presenteeism...... suggests that working while ill may also be a significant risk factor for the development of depression....

  4. Some determinants of sick leave for respiratory disease : Occupation, asthma, obesity, smoking and rehabilitation

    OpenAIRE

    Nathell, Lennart

    2002-01-01

    The cost to society of sick leave and disability pensions is currently the most urgent economic problem in Sweden. The availability of a large sick-listing database, Collective Group Health Insurance, AGS (in Swedish: Avtalsgruppsjukförsäkring) provides a rare opportunity to study sick leave in Sweden. Periods of sick leave exceeding 14 days are recorded together with a mandatory diagnosis by a physician, gender, age, residential area, name of the employer, and occupation. ...

  5. Predictive validity of common mental disorders screening questionnaire as a screening instrument in long sickness absence

    DEFF Research Database (Denmark)

    Søgaard, Hans Jørgen; Bech, Per

    2010-01-01

    AIMS: Screening instruments for detection of common mental disorders have not been validity tested in long term sickness absence (LSA), which is the aim of this study for the Common Mental Disorders Screening Questionnaire (CMD-SQ). METHODS: Of all 2,414 incident persons on continuous sick...... in Denmark there is not a legal requirement that sick-listed persons are certified as sick by a physician....

  6. Time travel in Goedel's space

    International Nuclear Information System (INIS)

    Pfarr, J.

    1981-01-01

    An analysis is presented of the motion of test particles in Goedel's universe. Both geodesical and nongeodesical motions are considered; the accelerations for nongeodesical motions are given. Examples for closed timelike world lines are shown and the dynamical conditions for time travel in Goedel's space-time are discussed. It is shown that these conditions alone do not suffice to exclude time travel in Goedel's space-time. (author)

  7. The effect on length of sickness absence by recognition of undetected psychiatric disorder in long-term sickness absence

    DEFF Research Database (Denmark)

    Søgaard, Hans Jørgen; Bech, Per

    2009-01-01

    of return to work. METHODS: Over one year all 2,414 incident persons on LSA in a well-defined population were within one week after eight weeks of continuous sickness absence posted the Common Mental Disorders Screening Questionnaire (CMD-SQ) to screen for mental disorders. In a randomized controlled trial...... (RCT), of 1,121 responding participants, persons with a minimum level of psychiatric symptoms 420 were allocated to the intervention group and 416 to the control group. The intervention was a psychiatric examination including diagnostics with Present State Examination and feedback regarding treatment...... to work. RESULTS: The rate of return to work was non-significantly lower for the intervention group than for the control group, except for persons without a psychiatric sick-leave diagnosis who were sick-listed from full time work, who showed a significantly higher rate of return to work...

  8. Integration Method of Emphatic Motions and Adverbial Expressions with Scalar Parameters for Robotic Motion Coaching System

    Science.gov (United States)

    Okuno, Keisuke; Inamura, Tetsunari

    A robotic coaching system can improve humans' learning performance of motions by intelligent usage of emphatic motions and adverbial expressions according to user reactions. In robotics, however, method to control both the motions and the expressions and how to bind them had not been adequately discussed from an engineering point of view. In this paper, we propose a method for controlling and binding emphatic motions and adverbial expressions by using two scalar parameters in a phase space. In the phase space, variety of motion patterns and verbal expressions are connected and can be expressed as static points. We show the feasibility of the proposing method through experiments of actual sport coaching tasks for beginners. From the results of participants' improvements in motion learning, we confirmed the feasibility of the methods to control and bind emphatic motions and adverbial expressions, as well as confirmed contribution of the emphatic motions and positive correlation of adverbial expressions for participants' improvements in motion learning. Based on the results, we introduce a hypothesis that individually optimized method for binding adverbial expression is required.

  9. Mental imagery of gravitational motion.

    Science.gov (United States)

    Gravano, Silvio; Zago, Myrka; Lacquaniti, Francesco

    2017-10-01

    There is considerable evidence that gravitational acceleration is taken into account in the interaction with falling targets through an internal model of Earth gravity. Here we asked whether this internal model is accessed also when target motion is imagined rather than real. In the main experiments, naïve participants grasped an imaginary ball, threw it against the ceiling, and caught it on rebound. In different blocks of trials, they had to imagine that the ball moved under terrestrial gravity (1g condition) or under microgravity (0g) as during a space flight. We measured the speed and timing of the throwing and catching actions, and plotted ball flight duration versus throwing speed. Best-fitting duration-speed curves estimate the laws of ball motion implicit in the participant's performance. Surprisingly, we found duration-speed curves compatible with 0g for both the imaginary 0g condition and the imaginary 1g condition, despite the familiarity with Earth gravity effects and the added realism of performing the throwing and catching actions. In a control experiment, naïve participants were asked to throw the imaginary ball vertically upwards at different heights, without hitting the ceiling, and to catch it on its way down. All participants overestimated ball flight durations relative to the durations predicted by the effects of Earth gravity. Overall, the results indicate that mental imagery of motion does not have access to the internal model of Earth gravity, but resorts to a simulation of visual motion. Because visual processing of accelerating/decelerating motion is poor, visual imagery of motion at constant speed or slowly varying speed appears to be the preferred mode to perform the tasks. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Mitigating vestibular disturbances during space flight using virtual reality training and reentry vehicle design guidelines

    Science.gov (United States)

    Stroud, Kenneth Joshua

    Seventy to eighty percent of astronauts reportedly exhibit undesirable vestibular disturbances during the first few days of weightlessness, including space motion sickness (SMS) and spatial disorientation (SD). SMS presents a potentially dangerous situation, both because critical piloted tasks such as docking maneuvers and emergency reentry may be compromised, and because of the potential for asphyxiation should an astronaut vomit while wearing a space suit. SD can be provocative for SMS as well as become dangerous during an emergency in which it is critical for an astronaut to move quickly through the vehicle. In the U.S. space program, medication is currently used both for prevention and treatment of SMS. However, this approach has had only moderate success, and the side effects of drowsiness and lack of concentration are undesirable. Research suggests that preflight training in virtual reality devices can simulate certain aspects of microgravity and may prove to be an effective countermeasure for SMS and SD. It was hypothesized that exposing subjects preflight to variable virtual orientations, similar to those encountered during space flight, will reduce the incidence and/or severity of SMS and SD. Results from a study conducted at the NASA Johnson Space Center as part of this research demonstrated that this type of training is effective for reducing motion sickness and improving task performance in potentially disorienting visual surroundings, thus suggesting the possibility that such training may prove an effective countermeasure for SMS, SD and related performance decrements that occur in space flight. In addition to the effects associated with weightlessness, almost all astronauts experience vestibular disturbances associated with gravity-transitions incurred during the return to Earth, which could be exacerbated if traveling in a spacecraft that is designed differently than a conventional aircraft. Therefore, for piloted descent and landing operations

  11. Associations of work ability with frequent and long-term sickness absence

    NARCIS (Netherlands)

    Notenbomer, A.; Groothoff, J. W.; van Rhenen, W.; Roelen, C. A. M.

    Background Reduced work ability is related to long-term sickness absence. The relationship between work ability and frequent sickness absence has not previously been investigated. It is important to distinguish between frequent and long-term sickness absence as they are outcomes of different

  12. Care for Sick Children as a Proxy for Gender Equality in the Family

    Science.gov (United States)

    Eriksson, Rickard; Nermo, Magnus

    2010-01-01

    Swedish parents are entitled to government paid benefits to take care of sick children. In this paper we show that the gender distribution of paid care for sick children is a good proxy for the gender division of household work. Using two examples we show that registry data on care for sick children is a useful data source for studies on gender…

  13. Attention and apparent motion.

    Science.gov (United States)

    Horowitz, T; Treisman, A

    1994-01-01

    Two dissociations between short- and long-range motion in visual search are reported. Previous research has shown parallel processing for short-range motion and apparently serial processing for long-range motion. This finding has been replicated and it has also been found that search for short-range targets can be impaired both by using bicontrast stimuli, and by prior adaptation to the target direction of motion. Neither factor impaired search in long-range motion displays. Adaptation actually facilitated search with long-range displays, which is attributed to response-level effects. A feature-integration account of apparent motion is proposed. In this theory, short-range motion depends on specialized motion feature detectors operating in parallel across the display, but subject to selective adaptation, whereas attention is needed to link successive elements when they appear at greater separations, or across opposite contrasts.

  14. Sick-listing adherence: a register study of 1.4 million episodes of sickness benefit 2010-2013 in Sweden.

    Science.gov (United States)

    Leijon, Ola; Josephson, Malin; Österlund, Niklas

    2015-04-14

    This register study aims to increase the knowledge on how common it is that sickness benefit recipients are sick-listed for as long as their physician prescribes in their medical sickness certificate, i.e. sick-listing adherence, or wholly/partly bring return-to-work (RTW) forward, i.e. early RTW. The unit for analysis was an episode of 100% sickness benefit, commenced between 1 January 2010 and 31 December 2013. Completed episodes of sickness benefit and full or partial early RTW was analysed by comparing the prescribed length of sick leave in medical sickness certificates and benefit days disbursed by the sickness insurance system. Probability for a full and partial early RTW was estimated with hazard ratio (HR) using the Cox proportional hazard model. In total, about 1.4 million episodes of sickness benefit (60% women) were included in the study. The overall sick-listing adherence was 84% for women and 82% for men during the first year of sick leave. Adherence varied between 82 and 87% among women and between 79 and 86% among men with regard to ICD-10 diagnosis chapter. The probability of an early RTW varied between diagnosis chapters, where mental disorders was associated with a lower probability of a full early RTW among women and men (HR 0.52 and HR 0.47) as well as a partial early RTW (HR 0.51 and HR 0.46). Younger age (16-29 years), high educational level and high income was associated with a higher probability of an early RTW, while older age (≥ 50 years), not native-born, low educational level, unemployment and parental leave were associated with a lower probability. The study demonstrates that sick-listing adherence is relatively high. Probability of an early RTW differs with regard to diagnosis chapter, demographic, socioeconomic and labour market characteristics of the sickness benefit recipients. Interventions intended to improve the sick-listing process, and to affect the length and degree of sick leave in certain target groups, should include

  15. Are environmental characteristics in the municipal eldercare, more closely associated with frequent short sick leave spells among employees than with total sick leave: a cross-sectional study

    Science.gov (United States)

    2013-01-01

    Background It has been suggested that frequent-, short-term sick leave is associated with work environment factors, whereas long-term sick leave is associated mainly with health factors. However, studies of the hypothesis of an association between a poor working environment and frequent short spells of sick leave are few and results are inconsistent. Therefore, we aimed to explore associations between self-reported psychosocial work factors and workplace-registered frequency and length of sick leave in the eldercare sector. Methods Employees from the municipal eldercare in Aarhus (N = 2,534) were included. In 2005, they responded to a work environment questionnaire. Sick leave records from 2005 were dichotomised into total sick leave days (0–14 and above 14 days) and into spell patterns (0–2 short, 3–9 short, and mixed spells and 1–3 long spells). Logistic regression models were used to analyse associations; adjusted for age, gender, occupation, and number of spells or sick leave length. Results The response rate was 76%; 96% of the respondents were women. Unfavourable mean scores in work pace, demands for hiding emotions, poor quality of leadership and bullying were best indicated by more than 14 sick leave days compared with 0–14 sick leave days. For work pace, the best indicator was a long-term sick leave pattern compared with a non-frequent short-term pattern. A frequent short-term sick leave pattern was a better indicator of emotional demands (1.62; 95% CI: 1.1-2.5) and role conflict (1.50; 95% CI: 1.2-1.9) than a short-term non-frequent pattern. Age (= 40 years) statistically significantly modified the association between the 1–3 long-term sick leave spell pattern and commitment to the workplace compared with the 3–9 frequent short-term pattern. Conclusions Total sick leave length and a long-term sick leave spell pattern were just as good or even better indicators of unfavourable work factor scores than a frequent short-term sick leave

  16. Objects in Motion

    Science.gov (United States)

    Damonte, Kathleen

    2004-01-01

    One thing scientists study is how objects move. A famous scientist named Sir Isaac Newton (1642-1727) spent a lot of time observing objects in motion and came up with three laws that describe how things move. This explanation only deals with the first of his three laws of motion. Newton's First Law of Motion says that moving objects will continue…

  17. Motion compensated digital tomosynthesis

    NARCIS (Netherlands)

    van der Reijden, Anneke; van Herk, Marcel; Sonke, Jan-Jakob

    2013-01-01

    Digital tomosynthesis (DTS) is a limited angle image reconstruction method for cone beam projections that offers patient surveillance capabilities during VMAT based SBRT delivery. Motion compensation (MC) has the potential to mitigate motion artifacts caused by respiratory motion, such as blur. The

  18. Reflection Negative Kernels and Fractional Brownian Motion

    Directory of Open Access Journals (Sweden)

    Palle E. T. Jorgensen

    2018-06-01

    Full Text Available In this article we study the connection of fractional Brownian motion, representation theory and reflection positivity in quantum physics. We introduce and study reflection positivity for affine isometric actions of a Lie group on a Hilbert space E and show in particular that fractional Brownian motion for Hurst index 0 < H ≤ 1 / 2 is reflection positive and leads via reflection positivity to an infinite dimensional Hilbert space if 0 < H < 1 / 2 . We also study projective invariance of fractional Brownian motion and relate this to the complementary series representations of GL 2 ( R . We relate this to a measure preserving action on a Gaussian L 2 -Hilbert space L 2 ( E .

  19. The effects of area postrema lesions and selective vagotomy on motion-induced conditioned taste aversion

    Science.gov (United States)

    Fox, Robert A.; Sutton, R. L.; Mckenna, Susan

    1991-01-01

    Conditioned taste aversion (CTA) is one of several behaviors which was suggested as a putative measure of motion sickness in rats. A review is made of studies which used surgical disruption of area postrema or the vagus nerve to investigate whether CTA and vomiting induced by motion may depend on common neural pathways or structures. When the chemoreceptive function of the area postrema (AP) is destroyed by complete ablation, rats develop CTA and cats and monkeys develop CTA and vomit. Thus the AP is not crucially involved in either CTA or vomiting induced by motion. However, after complete denervation of the stomach or after labyrinthectomy rats do not develop CTA when motion is used as the unconditioned stimulus. Studies of brainstem projections of the vagus nerve, the area postrema, the periaqueductal grey, and the vestibular system are used as the basis for speculation about regions which could mediate both motion-induced vomiting and behavioral food aversion.

  20. Auditory capture of visual motion: effects on perception and discrimination.

    Science.gov (United States)

    McCourt, Mark E; Leone, Lynnette M

    2016-09-28

    We asked whether the perceived direction of visual motion and contrast thresholds for motion discrimination are influenced by the concurrent motion of an auditory sound source. Visual motion stimuli were counterphasing Gabor patches, whose net motion energy was manipulated by adjusting the contrast of the leftward-moving and rightward-moving components. The presentation of these visual stimuli was paired with the simultaneous presentation of auditory stimuli, whose apparent motion in 3D auditory space (rightward, leftward, static, no sound) was manipulated using interaural time and intensity differences, and Doppler cues. In experiment 1, observers judged whether the Gabor visual stimulus appeared to move rightward or leftward. In experiment 2, contrast discrimination thresholds for detecting the interval containing unequal (rightward or leftward) visual motion energy were obtained under the same auditory conditions. Experiment 1 showed that the perceived direction of ambiguous visual motion is powerfully influenced by concurrent auditory motion, such that auditory motion 'captured' ambiguous visual motion. Experiment 2 showed that this interaction occurs at a sensory stage of processing as visual contrast discrimination thresholds (a criterion-free measure of sensitivity) were significantly elevated when paired with congruent auditory motion. These results suggest that auditory and visual motion signals are integrated and combined into a supramodal (audiovisual) representation of motion.

  1. Gambiense Sleeping Sickness In The Abraka Region Of Delta State ...

    African Journals Online (AJOL)

    Gambiense Sleeping Sickness In The Abraka Region Of Delta State, Nigeria: Passive Case Detection (Pcd) At The Baptist Medical Centre (BMC) Eku 1999 – 2004. ... The highest prevalence of infection was among patients aged between 26-35 years with 35.6% infection rate, 23.3 percent was recorded among those aged ...

  2. [Sick teachers? --Analysis of disability data from Mecklenburg-Vorpommern].

    Science.gov (United States)

    Meierjürgen, R; Paulus, P

    2002-11-01

    Based on a review of the latest research results on teachers' health, the review shows the extent as well as the structure of sick-leave of people working in schools in the Bundesland Mecklenburg-Vorpommern. Data concerning diseases of more than 7,000 employees who are insured by the Barmer Ersatzkasse were analysed. The results show that teachers are more often sick than all the persons insured by the Barmer Ersatzkasse. Differences between sexes show disadvantages for women. The sick-leave rates increase with age. Dominant diseases reflect very well the job routine of people working in schools: The most frequent diseases concern the respiratory organs, the skeleton, muscles and the connective tissue and mental illness issues; mental illnesses cause the longest periods of disablement. The conclusion refers to the restrictions of sick-leave statistics. It is argued that it is necessary to combine different data sources (e. g. work-place health reports) in order to get a more differentiated picture of factors of demand and strain on teachers' health.

  3. Psychosocial work factors and long sickness absence in Europe.

    Science.gov (United States)

    Slany, Corinna; Schütte, Stefanie; Chastang, Jean-François; Parent-Thirion, Agnès; Vermeylen, Greet; Niedhammer, Isabelle

    2014-01-01

    Studies exploring a wide range of psychosocial work factors separately and together in association with long sickness absence are still lacking. The objective of this study was to explore the associations between psychosocial work factors measured following a comprehensive instrument (Copenhagen psychosocial questionnaire, COPSOQ) and long sickness absence (> 7 days/year) in European employees of 34 countries. An additional objective was to study the differences in these associations according to gender and countries. The study population consisted of 16 120 male and 16 588 female employees from the 2010 European working conditions survey. Twenty-five psychosocial work factors were explored. Statistical analysis was performed using multilevel logistic regression models and interaction testing. When studied together in the same model, factors related to job demands (quantitative demands and demands for hiding emotions), possibilities for development, social relationships (role conflicts, quality of leadership, social support, and sense of community), workplace violence (physical violence, bullying, and discrimination), shift work, and job promotion were associated with long sickness absence. Almost no difference was observed according to gender and country. Comprehensive prevention policies oriented to psychosocial work factors may be useful to prevent long sickness absence at European level.

  4. General introduction to altitude adaptation and mountain sickness

    DEFF Research Database (Denmark)

    Bartsch, P.; Saltin, B.

    2008-01-01

    ascent (average ascent rate 300 m/day above 2000 m a.s.l.), primarily in order to sleep and feel well, and minimize the risk of mountain sickness. A new classification of altitude levels based on the effects on performance and well-being is proposed and an overview given over the various modalities using...

  5. What bothers the sick-listed employee with severe MUPS?

    NARCIS (Netherlands)

    Hoedeman, R.; Blankenstein, A. H.; Koopmans, P. C.; Groothoff, J. W.

    Aims: The aim of this study was to explore what employees with severe medically unexplained physical symptoms (MUPS) experience as causes of distress with regard to employees with mild or no MUPS. Methods: This study is an additional analysis of a cross-sectional study in which 486 sick-listed

  6. Common mental disorders : Prediction of sickness absence durations and recurrences

    NARCIS (Netherlands)

    Kuper, Lammechiena

    2016-01-01

    Psychological disorders cause a considerable proportion of long-term sickness absence and constitute the most significant reason for disability pensions of employees under 55 years of age. Knowledge of the risk factors will help occupational physicians to initiate treatments and interventions at an

  7. A LITERATURE REVIEW ON SICK LEAVE DETERMINANTS (1984-2004)

    NARCIS (Netherlands)

    Beemsterboer, Willibrord; Stewart, Roy; Groothoff, Johan; Nijhuis, Frans

    2009-01-01

    Objectives: A literature review for the years 1984-2004 was performed to identify the determinants of the sick leave frequency and duration over that period and to establish the continuity in the character of those determinants. Materials and Methods: The review referred to national and

  8. Pathophysiology of acute mountain sickness and high altitude pulmonary oedema

    DEFF Research Database (Denmark)

    Sutton, J R; Lassen, N

    1979-01-01

    We review the evidence that acute mountain sickness (AMS) and high altitude pulmonary oedema (HAPO) occur together more often than is realized. We hypothesize that AMS and HAPO have a common pathophysiological basis: both are due to increased pressure and flow in the microcirculation, causing...

  9. 20 CFR 335.2 - Manner of claiming sickness benefits.

    Science.gov (United States)

    2010-04-01

    ..., or in the case of a female employee, pregnancy, miscarriage, or childbirth, an employee must file the... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Manner of claiming sickness benefits. 335.2 Section 335.2 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD UNEMPLOYMENT...

  10. Mental disorder sick leave in Sweden: A population study.

    Science.gov (United States)

    Lidwall, Ulrik; Bill, Sofia; Palmer, Edward; Olsson Bohlin, Christina

    2018-01-01

    The inability to perform productive work due to mental disorders is a growing concern in advanced societies. To investigate medically certified mental disorder and all-cause sick leave in a working population using demographic, socioeconomic and occupational predictors. The study population was the entire Swedish work force aged 16-64 years in December 31st 2011. The outcome was sick leave exceeding 14 days in 2012 with adjustment for 13 confounders. The risk of sick leave with a mental disorder is higher among women compared to men, among persons aged 30-39 and among parents in families with underage children. Employees in welfare service occupations within health care, education and social services have an elevated risk of mental disorder sick leave and constitute a large proportion of the workforce. The results support the need for improving early detection and prevention of mental disorders in the workforce. Improvements in psychosocial work environments are essential, where the higher risk in female dominated welfare occupations particularly, have repercussions on the quality of the welfare services provided for vulnerable groups in society. Better work-life balance in families with younger children could also mitigate the effects of a high total workload in that particular phase of life.

  11. Dose-response relation between physical activity and sick leave

    NARCIS (Netherlands)

    Proper, K.I.; Heuvel, S.G. van den; Vroome, E.M. de; Hildebrandt, V.H.; Beek, A.J. van der

    2006-01-01

    Objective: To investigate the dose-response relation between moderate and vigorous physical activity and sick leave in a working population. Methods: Data were used from three large Dutch databases: two continuous, cross sectional surveys among a representative sample of the Dutch population and one

  12. Effect of carbon dioxide in acute mountain sickness

    DEFF Research Database (Denmark)

    Harvey, T C; Raichle, M E; Winterborn, M H

    1988-01-01

    of the respiratory alkalosis normally seen at high altitude. Symptoms of acute mountain sickness were rapidly relieved. In three subjects cerebral blood flow increased by 17-39%, so that oxygen delivery to the brain would have been considerably improved. This study confirms earlier suggestions of the beneficial...

  13. Atrial fibrillation in patients with sick sinus syndrome

    DEFF Research Database (Denmark)

    Nielsen, Jens Cosedis; Thomsen, Poul Erik B; Højberg, Søren

    2012-01-01

    between minimal-paced programmed AVI = 100 and >100 ms (median value), respectively (P= 0.60).ConclusionsThe present study indicates that a longer baseline PQ-interval is associated with an increased risk of AF in patients with sick sinus syndrome. Atrial fibrillation burden is not associated...

  14. Management of Sick Leave due to Musculoskeletal Disorders

    NARCIS (Netherlands)

    E. Faber (Elske)

    2007-01-01

    textabstractMusculoskeletal disorders are a common problem that may lead to func-Ational limitations and (work) disability. It is not clear yet how improvement in Apain or functional limitations is related to return to work after an episode of sick Aleave. Furthermore, several physicians are

  15. Dexmedetomidine reduces lipopolysaccharide induced neuroinflammation, sickness behavior, and anhedonia.

    Directory of Open Access Journals (Sweden)

    Ching-Hua Yeh

    Full Text Available Peripheral innate immune response may induce sickness behavior through activating microglia, excessive cytokines production, and neuroinflammation. Dexmedetomidine (Dex has anti-inflammatory effect. We investigated the effects of Dex on lipopolysaccharide (LPS-induced neuroinflammation and sickness behavior in mice.BALB/c mice were intraperitoneally (i.p. injected with Dex (50 ug/kg or vehicle. One hour later, the mice were injected (i.p. with Escherichia coli LPS (0.33 mg/kg or saline (n = 6 in each group. We analyzed the food and water intake, body weight loss, and sucrose preference of the mice for 24h. We also determined microglia activation and cytokines expression in the brains of the mice. In vitro, we determine cytokines expression in LPS-treated BV-2 microglial cells with or without Dex treatment.In the Dex-pretreated mice, LPS-induced sickness behavior (anorexia, weight loss, and social withdrawal were attenuated and microglial activation was lower than vehicle control. The mRNA expression of TNF-α, MCP-1, indoleamine 2, 3 dioxygenase (IDO, caspase-3, and iNOS were increased in the brain of LPS-challenged mice, which were reduced by Dex but not vehicle.Dexmedetomidine diminished LPS-induced neuroinflammation in the mouse brain and modulated the cytokine-associated changes in sickness behavior.

  16. Sickness absenteeism at an all-time low

    NARCIS (Netherlands)

    Klein Hesselink, J.

    2011-01-01

    Absenteeism in the Netherlands rose steadily in the 1960s and 70s, driven by legislation that made it attractive for employees to take long-term sick leave. Changes in laws on absenteeism and disability seem to have been a driving force behind the fall in rates since the early 1980s and employers

  17. Is there a suburban sleeping sickness in Libreville? | Kohagne ...

    African Journals Online (AJOL)

    Background: The transmission of sleeping sickness occurs primarily in rural areas, and exposed populations are those living from rural activities such as agriculture, fishing, animal husbandry or hunting. However, urban and suburban foci are more and more reported in T. b. gambiense areas. In Libreville town, sleeping ...

  18. The sweating sickness in England | Sloan | South African Medical ...

    African Journals Online (AJOL)

    An acute infect;ous fever, called the sweating sickness, broke out in England in five major epidemics in the years 1485, 1508, 1517, 1528 and 1551. Only one epidemic, that of 1528, spread also on the continent of Europe. The disease I-vas characterized by headache, pain in the chest, and profuse sweating, and frequently ...

  19. Rolling Shutter Motion Deblurring

    KAUST Repository

    Su, Shuochen

    2015-06-07

    Although motion blur and rolling shutter deformations are closely coupled artifacts in images taken with CMOS image sensors, the two phenomena have so far mostly been treated separately, with deblurring algorithms being unable to handle rolling shutter wobble, and rolling shutter algorithms being incapable of dealing with motion blur. We propose an approach that delivers sharp and undis torted output given a single rolling shutter motion blurred image. The key to achieving this is a global modeling of the camera motion trajectory, which enables each scanline of the image to be deblurred with the corresponding motion segment. We show the results of the proposed framework through experiments on synthetic and real data.

  20. Smoothing Motion Estimates for Radar Motion Compensation.

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-07-01

    Simple motion models for complex motion environments are often not adequate for keeping radar data coherent. Eve n perfect motion samples appli ed to imperfect models may lead to interim calculations e xhibiting errors that lead to degraded processing results. Herein we discuss a specific i ssue involving calculating motion for groups of pulses, with measurements only available at pulse-group boundaries. - 4 - Acknowledgements This report was funded by General A tomics Aeronautical Systems, Inc. (GA-ASI) Mission Systems under Cooperative Re search and Development Agre ement (CRADA) SC08/01749 between Sandia National Laboratories and GA-ASI. General Atomics Aeronautical Systems, Inc. (GA-ASI), an affilia te of privately-held General Atomics, is a leading manufacturer of Remotely Piloted Aircraft (RPA) systems, radars, and electro-optic and rel ated mission systems, includin g the Predator(r)/Gray Eagle(r)-series and Lynx(r) Multi-mode Radar.

  1. Part-time sick leave as a treatment method for individuals with musculoskeletal disorders

    OpenAIRE

    Andrén, Daniela; Svensson, Mikael

    2009-01-01

    There is increasing evidence that staying active is an important part of a recovery process for individuals on sick leave due to musculoskeletal disorders (MSDs). It has been suggested that using part-time sick-leave rather than full-time sick leave will enhance the possibility of full recovery to the workforce, and several countries actively favor this policy. However, to date only few studies have estimated the effect of using part-time sick leave in contrast to full-time sick leave. In thi...

  2. Ventilation in day-care centres and sick leave among nursery children

    DEFF Research Database (Denmark)

    Kolarik, Barbara; Andersen, Zorana Jovanovic; Ibfelt, Tobias

    2016-01-01

    ventilation in DCCs and sick leave among nursery children. Data on child sick leave within an 11 week period was obtained for 635 children attending 20 DCCs. Ventilation measurements included three proxies of ventilation: air exchange rate (ACR) measured with the decay method, ACR measured...... inverse relationship between the number of sick days and ACR measured with the decay method was found for crude and adjusted analysis, with a 12% decrease in number of sick days per 1 h(-1) increase in ACR measured with the decay method. This study suggests a relationship between sick leave among nursery...

  3. Longitudinal associations of active commuting with wellbeing and sickness absence.

    Science.gov (United States)

    Mytton, Oliver Tristan; Panter, Jenna; Ogilvie, David

    2016-03-01

    Our aim was to explore longitudinal associations of active commuting (cycling to work and walking to work) with physical wellbeing (PCS-8), mental wellbeing (MCS-8) and sickness absence. We used data from the Commuting and Health in Cambridge study (2009 to 2012; n=801) to test associations between: a) maintenance of cycling (or walking) to work over a one year period and indices of wellbeing at the end of that one year period; and b) associations between change in cycling (or walking) to work and change in indices of wellbeing. Linear regression was used for testing associations with PCS-8 and MCS-8, and negative binomial regression for sickness absence. After adjusting for sociodemographic variables, physical activity and physical limitation, those who maintained cycle commuting reported lower sickness absence (0.46, 95% CI: 0.14-0.80; equivalent to one less day per year) and higher MCS-8 scores (1.50, 0.10-2.10) than those who did not cycle to work. The association for sickness absence persisted after adjustment for baseline sickness absence. No significant associations were observed for PCS-8. Associations between change in cycle commuting and change in indices of wellbeing were not significant. No significant associations were observed for walking. This work provides some evidence of the value of cycle commuting in improving or maintaining the health and wellbeing of adults of working age. This may be important in engaging employers in the promotion of active travel and communicating the benefits of active travel to employees. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  4. Curves from Motion, Motion from Curves

    Science.gov (United States)

    2000-01-01

    De linearum curvarum cum lineis rectis comparatione dissertatio geometrica - an appendix to a treatise by de Lalouv~re (this was the only publication... correct solution to the problem of motion in the gravity of a permeable rotating Earth, considered by Torricelli (see §3). If the Earth is a homogeneous...in 1686, which contains the correct solution as part of a remarkably comprehensive theory of orbital motions under centripetal forces. It is a

  5. Structural motion engineering

    CERN Document Server

    Connor, Jerome

    2014-01-01

    This innovative volume provides a systematic treatment of the basic concepts and computational procedures for structural motion design and engineering for civil installations. The authors illustrate the application of motion control to a wide spectrum of buildings through many examples. Topics covered include optimal stiffness distributions for building-type structures, the role of damping in controlling motion, tuned mass dampers, base isolation systems, linear control, and nonlinear control. The book's primary objective is the satisfaction of motion-related design requirements, such as restrictions on displacement and acceleration. The book is ideal for practicing engineers and graduate students. This book also: ·         Broadens practitioners' understanding of structural motion control, the enabling technology for motion-based design ·         Provides readers the tools to satisfy requirements of modern, ultra-high strength materials that lack corresponding stiffness, where the motion re...

  6. Predictors of recurrent sickness absence among workers having returned to work after sickness absence due to common mental disorders

    NARCIS (Netherlands)

    Arends, I.; van der Klink, J.J.L.; van Rhenen, W.; de Boer, M.R.; Bultmann, U.

    2014-01-01

    Objective The aim of this study was to investigate whether sociodemographic, disease-related, personal, and work-related factors - measured at baseline - are predictors of recurrent sickness absence (SA) at 6 and 12 months follow-up among workers who returned to work after SA due to common mental

  7. Predictors of recurrent sickness absence among workers having returned to work after sickness absence due to common mental disorders

    NARCIS (Netherlands)

    Arends, Iris; van der Klink, Jac J. L.; van Rhenen, Willem; de Boer, Michiel R.; Bultmann, Ute

    Objective The aim of this study was to investigate whether sociodemographic, disease-related, personal, and work-related factors - measured at baseline - are predictors of recurrent sickness absence (SA) at 6 and 12 months follow-up among workers who returned to work after SA due to common mental

  8. Sick leave and depression - determining factors and clinical effect in outpatient care.

    Science.gov (United States)

    Bermejo, Isaac; Kriston, Levente; Schneider, Frank; Gaebel, Wolfgang; Hegerl, Ulrich; Berger, Mathias; Härter, Martin

    2010-12-30

    Sickness leave is a major source of societal costs in depression treatment. However, very little is known about the rationale behind sick leave and their effects on depressive symptoms. Aim of the paper is to evaluate the effect of sick leave on treatment outcome and the association of sick leave with patient, depression and treatment-related factors. For this we compared patients with sick leave and non-sick leave regarding symptom reduction following 6 weeks of treatment. A total of 118 patients of 41 physicians in a controlled clinical trial with a naturalistic prospective design were analysed. After 8 weeks of treatment no significant differences were found between patients who had or did not have sick leave, in terms of improvement of depressive symptoms. The analyses of physician, patient and illness-related variables regarding their predictive value showed no significant effect. No systematic effect of sick leave and no clear criteria were found that were related to receiving a sick leave certificate. It can be assumed that physicians do not only base the decision of whether to sign a depressive patient off sick on illness-specific factors. For a targeted implementation of sick leave as therapeutic measure predictors for effectiveness should be defined. Copyright © 2010 Elsevier Ltd. All rights reserved.

  9. Does evening work predict sickness absence among female carers of the elderly?

    DEFF Research Database (Denmark)

    Tüchsen, Finn; Christensen, Karl Bang; Nabe-Nielsen, Kirsten

    2008-01-01

    OBJECTIVES: The aim of the present study was to predict the risk ratio of sickness absence lasting > or = 2 weeks due to shift work among Danish workers caring for the elderly during the evening and at night. METHODS: A sample of Danish carers of the elderly were interviewed in 2005. The response...... rate was 78%. A cohort of 5627 shift and day workers was followed for sickness absence lasting > or = 2 weeks and for sickness absence lasting > or = 8 weeks in a sickness compensation register covering all social transfer payments in Denmark. RESULTS: Among the evening workers, the rate ratio (RR......) of sickness absence lasting > or = 2 weeks was 1.29 (95% confidence interval (95% CI) 1.10-1.52). The rate ratio for sickness absence lasting > or = 8 weeks was 1.24 (95% CI 0.99-1.56). CONCLUSIONS: Evening work may cause long-term sickness absence lasting > or = 2 weeks....

  10. Motion Capturing Emotions

    Directory of Open Access Journals (Sweden)

    Wood Karen

    2017-12-01

    Full Text Available The paper explores the activities conducted as part of WhoLoDancE: Whole Body Interaction Learning for Dance Education which is an EU-funded Horizon 2020 project. In particular, we discuss the motion capture sessions that took place at Motek, Amsterdam as well as the dancers’ experience of being captured and watching themselves or others as varying visual representations through the HoloLens. HoloLens is Microsoft’s first holographic computer that you wear as you would a pair of glasses. The study embraced four dance genres: Ballet, Contemporary, Flamenco and Greek Folk dance. We are specifically interested in the kinesthetic and emotional engagement with the moving body and what new corporeal awareness may be experienced. Positioning the moving, dancing body as fundamental to technological advancements, we discuss the importance of considering the dancer’s experience in the real and virtual space. Some of the artists involved in the project have offered their experiences, which are included, and they form the basis of the discussion. In addition, we discuss the affect of immersive environments, how these environments expand reality and what effect (emotionally and otherwise that has on the body. The research reveals insights into relationships between emotion, movement and technology and what new sensorial knowledge this evokes for the dancer.

  11. Ethical and medical dilemmas of space tourism

    Science.gov (United States)

    Marsh, Melinda

    Space tourism is an important new venture, however it raises several issues that must be addressed; namely, the medical implications associated with space flight and potential for ethical problems surrounding the safety of such travel. It seems highly likely that businesses involved in space tourism could find themselves liable for any passenger deaths or injuries, if they are found to have been negligent. This paper, therefore, discusses such issues as the medical facilities that need to be made available on board a space facility, and the companies' duty to disclose to potential passengers the risks associated with microgravity and the likelihood of space sickness, loss of bone density, disease, and pregnancy.

  12. Onboard Risk-Aware Real-Time Motion Planning Algorithms for Spacecraft Maneuvering

    Data.gov (United States)

    National Aeronautics and Space Administration — Unlocking the next generation of complex missions for autonomous spacecraft will require significant advances in robust motion planning. The aim of motion planning...

  13. Motion and relativity

    CERN Document Server

    Infeld, Leopold

    1960-01-01

    Motion and Relativity focuses on the methodologies, solutions, and approaches involved in the study of motion and relativity, including the general relativity theory, gravitation, and approximation.The publication first offers information on notation and gravitational interaction and the general theory of motion. Discussions focus on the notation of the general relativity theory, field values on the world-lines, general statement of the physical problem, Newton's theory of gravitation, and forms for the equation of motion of the second kind. The text then takes a look at the approximation meth

  14. Brain Image Motion Correction

    DEFF Research Database (Denmark)

    Jensen, Rasmus Ramsbøl; Benjaminsen, Claus; Larsen, Rasmus

    2015-01-01

    The application of motion tracking is wide, including: industrial production lines, motion interaction in gaming, computer-aided surgery and motion correction in medical brain imaging. Several devices for motion tracking exist using a variety of different methodologies. In order to use such devices...... offset and tracking noise in medical brain imaging. The data are generated from a phantom mounted on a rotary stage and have been collected using a Siemens High Resolution Research Tomograph for positron emission tomography. During acquisition the phantom was tracked with our latest tracking prototype...

  15. Improved motion description for action classification

    Directory of Open Access Journals (Sweden)

    Mihir eJain

    2016-01-01

    Full Text Available Even though the importance of explicitly integrating motion characteristics in video descriptions has been demonstrated by several recent papers on action classification, our current work concludes that adequately decomposing visual motion into dominant and residual motions, i.e.: camera and scene motion, significantly improves action recognition algorithms. This holds true both for the extraction of the space-time trajectories and for computation of descriptors.We designed a new motion descriptor – the DCS descriptor – that captures additional information on local motion patterns enhancing results based on differential motion scalar quantities, divergence, curl and shear features. Finally, applying the recent VLAD coding technique proposed in image retrieval provides a substantial improvement for action recognition. These findings are complementary to each other and they outperformed all previously reported results by a significant margin on three challenging datasets: Hollywood 2, HMDB51 and Olympic Sports as reported in (Jain et al. (2013. These results were further improved by (Oneata et al. (2013; Wang and Schmid (2013; Zhu et al. (2013 through the use of the Fisher vector encoding. We therefore also employ Fisher vector in this paper and we further enhance our approach by combining trajectories from both optical flow and compensated flow. We as well provide additional details of DCS descriptors, including visualization. For extending the evaluation, a novel dataset with 101 action classes, UCF101, was added.

  16. Computational Approaches for Developing Active Radiation Dosimeters for Space Applications Based on New Paradigms for Risk Assessment

    Data.gov (United States)

    National Aeronautics and Space Administration — Exposure to ionizing radiation can cause acute injury or sickness in humans under circumstances of very large doses and it presents the possibility of causing cancer...

  17. Sickness absence: a systematic review and meta-analysis of psychological treatments for individuals on sick leave due to common mental disorders.

    Science.gov (United States)

    Salomonsson, Sigrid; Hedman-Lagerlöf, Erik; Öst, Lars-Göran

    2018-01-30

    Sick leave due to common mental disorders (CMDs) increase rapidly and present a major societal challenge. The overall effect of psychological interventions to reduce sick leave and symptoms has not been sufficiently investigated and there is a need for a systematic review and meta-analysis of the field. The aim of the present meta-analysis was to calculate the effect size of psychological interventions for CMDs on sick leave and psychiatric symptoms based on all published randomized controlled trials. Methodological quality, the risk of bias and publication bias were also assessed. The literature searches gave 2240 hits and 45 studies were included. The psychological interventions were more effective than care as usual on both reduced sick leave (g = 0.15) and symptoms (g = 0.21). There was no significant difference in effect between work focused interventions, problem-solving therapy, cognitive behavioural therapy or collaborative care. We conclude that psychological interventions are more effective than care as usual to reduce sick leave and symptoms but the effect sizes are small. More research is needed on psychological interventions that evaluate effects on sick leave. Consensual measures of sick leave should be established and quality of psychotherapy for patients on sick leave should be improved.

  18. Differences in predictors of return to work among long-term sick-listed employees with different self-reported reasons for sick leave

    NARCIS (Netherlands)

    Huijs, J.J.J.M.; Koppes, L.L.J.; Taris, T.W.; Blonk, R.W.B.

    2012-01-01

    Introduction The present study aimed to gain insight in the predictors of full return to work (RTW) among employees on long-term sick leave due to three different self-reported reasons for sick leave: physical, mental or comorbid physical and mental problems. This knowledge can be used to develop

  19. Common Mental Disorders in Longterm-Sickness Absence

    DEFF Research Database (Denmark)

    Søgaard, Hans Jørgen

    provided, in a randomized controlled design, a psychiatric examination giving feedback to the individuals, primary care, and rehabilitation officers with regard to treatment and rehabilitation. Half of individuals who just had passed eight weeks of continuous sickness absence had a mental disorder of which......Common Mental Disorders (CMD) such as depression, anxiety, and somatoform disorders impose heavy burdens on individuals and on society in the form of sickness absence. CMD are frequently undetected in primary care which postpone the initiation of proper treatment. This seriously worsens return...... to work (RTW). Comorbidity with somatic disorders also worsens RTW. CMD are, controlled for lifestyle, independent causes for the development of chronic and disabling somatic disorders. Collaborative care seems to be most effective intervention with regard to RTW. In this dissertation, the intervention...

  20. Interaction of Physical Exposures and Occupational Factors on Sickness Absence in Automotive Industry Workers.

    Science.gov (United States)

    Valirad, Fateme; Ghaffari, Mostafa; Abdi, Alireza; Attarchi, Mirsaeed; Mircheraghi, Seyed Farzin; Mohammadi, Saber

    2015-04-23

    Increased sickness absence in recent years has been a trouble making issue in industrial society. Identify the causes of sickness absence and its influencing factors, is an important step to control and reduce its associated complications and costs. The aim of this study was to evaluate main factors associated with the incidence of sickness absence. In 2012, a cross-sectional study on 758 employees of a car accessories producing company was applied and relevant information about the number of days and episodes of sickness absence, Disease resulting in absence from work, personal features, occupational factors and physical exposures were collected. To determine risk factors associated with sickness absence, Logistic regression analysis was used. The most common diseases leading to sickness absence in order of frequency were Respiratory diseases, musculoskeletal disorders, gastrointestinal diseases and injuries at work. Musculoskeletal disorders increased the danger of long term absence by 4/33 times. Blue collar and shift works were the most important occupational factors associated with the incidence of sickness absence. The main physical factors that affect incidence of sickness absence were frequent bending-twisting and heavy lifting. Identifying controllable factors of sickness absence and trying to prevent and modify them such as compliance of ergonomic principals to decrease physical can be effective in reducing sickness absence.