565 research outputs found

    Integration of Kinesthetic and Tactile Display: A Modular Design Concept

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    This paper describes the systematic design of a modular setup for several integrated kinesthetic and cutaneous (tactile) display configurations. The proposed modular integration of a kinesthetic display and several tactile displays in serial configuration provides a versatile experimental setup to explore the integration of the kinesthetic and tactile modality of the human perception. The kinesthetic base display is a hyper-redundant device and sufficiently powerful to carry each of the compact tactile displays. In addition to a detailed description of the partly novel displays, a series of preliminary evaluation experiments is presented

    An instance of tactile suppression: Active exploration impairs tactile sensitivity for the direction of lateral movement

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    The phenomenon of a reduction in tactile sensitivity during voluntarily executed body movement we call “tactile suppression”. This is in analogy to saccadic suppression where the visual sensitivity is reduced during voluntarily executed eye movements [1]. Here we investigate tactile suppression using an integrated tactile/kinesthetic display – consisting of a tactile shear force device [2] mounted on a hyper redundant haptic display (ViSHaRD10 [3]). To quantify the tactile suppression effect we measured subject’s motion-direction discrimination performance for tactile stimuli moving laterally on the index finger under various active and passive exploration conditions. In the baseline condition (“static”) only tactile stimuli were provided using the shear-force device while the arm was held still. In the “active” condition subjects had to discriminate the direction of tactile motion while actively executing arm movements at the same time. Finally, in the “passive” condition the kinesthetic device passively moved the subjects’ arm, while the subject was performing the discrimination task. Compared to the “still” condition results indicate a significant decrease of tactile sensibility during active movements whereas passive movements seem to have a minor effect on tactile discrimination performance

    Assessment of Exposure to Shiftwork Mechanisms in the General Population: the Development of a New Job-Exposure Matrix

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    Objective. To develop a job-exposure matrix (JEM) that estimates exposure to eight variables representing different aspects of shiftwork among female workers. Methods. Occupational history and shiftwork exposure data were obtained from a population-based breast cancer case–control study. Exposure to light at night, phase shift, sleep disturbances, poor diet, lack of physical activity, lack of vitamin D, and graveyard and early morning shifts, was calculated by occupational code. Three threshold values based on the frequency of exposure were considered (10%, 30% and 50%) for use as cut-offs in determining exposure for each occupational code. JEM-based exposure classification was compared with that from the OccIDEAS application (job-specific questionnaires and assessment by rules) by assessing the effect on the OR for phase shift and breast cancer. Using data from the Australian Workplace Exposure Study, the specificity and sensitivity of the threshold values were calculated for each exposure variable. Results. 127 of 413 occupational codes involved exposure to one or more shiftwork variables. Occupations with the highest probability of exposure shiftwork included nurses and midwives. Using the 30% threshold, the OR for the association between phase shift exposure and breast cancer was decreased and no longer statistically significant (OR=1.14, 95% CI 0.92 to 1.42). The 30% cut-off point demonstrated best specificity and sensitivity, although results varied between exposure variables. Conclusions This JEM provides a set of indicators reflecting biologically plausible mechanisms for the potential impact of shiftwork on health and may provide an alternative method of exposure assessment in the absence of detailed job history and exposure data

    Spatial disparities in the reported incidence and survival of myeloproliferative neoplasms in Australia

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    Acknowledgments:The authors wish to thank the MPN Alliance Australia for motivating this study and financial support. We would also like to thank the reviewers for their helpful comments. Funding: was provided by the MPN Alliance Australia. The MPN Alliance Australia did not play any role in study design; in the collection, analysis and interpretation of data; in the writing of the report; or in the decision to submit the paper for publication.Peer reviewedPostprintPostprintPostprin

    Prevalence and patterns of self-reported animal-related injury among veterinarians in metropolitan Kampala

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    To establish the prevalence, patterns and risk factors of animal-related injuries among veterinarians, self-administered questionnaires were given to 60 veterinarians practicing in metropolitan Kampala. The prevalence of animal-related injuries in metropolitan Kampala was 72% (95%CI, 57~84). Some veterinarians (34%) suffered multiple injuries with a mean and median of 2.1 and 2.0 injuries per veterinarian, respectively. Of a total of 70 self-reported animal related injuries, cattle accounted for 72%, cats for 25%, dogs for 23%, self inoculation for 15% and birds for 13%. Injuries associated with poultry did not require hospital treatment. The upper limb was the most the frequently (68%) injured anatomical body part of veterinarians, and vaccination of animals (25%) was the major activity associated with injury. Animal-related injuries are common among practicing veterinarians in metropolitan Kampala; however, they did not differ significantly based on the veterinarian's gender, experience or risk awareness

    Left-handedness and risk of breast cancer

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    Left-handedness may be an indicator of intrauterine exposure to oestrogens, which may increase the risk of breast cancer. Women (n=1786) from a 1981 health survey in Busselton were followed up using death and cancer registries. Left-handers had higher risk of breast cancer than right-handers and the effect was greater for post-menopausal breast cancer (hazard ratio=2.59, 95% confidence interval 1.11–6.03)

    Chronotype and environmental light exposure in a student population

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    In humans and most other species, changes in the intensity and duration of light provide a critical set of signals for the synchronisation of the circadian system to the astronomical day. The timing of activity within the 24 h day defines an individual’s chronotype, i.e. morning, intermediate or evening type. The aim of this study was to investigate the associations between environmental light exposure, due to geographical location, on the chronotype of university students. Over 6 000 university students from cities in the Northern Hemisphere (Oxford, Munich and Groningen) and Southern Hemisphere (Perth, Melbourne and Auckland) completed the Munich ChronoType Questionnaire. In parallel, light measures (daily irradiance, timing of sunrise and sunset) were compiled from satellite or ground stations at each of these locations. Our data shows that later mid-sleep point on free days (corrected for oversleep on weekends MFSsc) is associated with (i) residing further from the equator, (ii) a later sunset, (iii) spending more time outside and (iv) waking from sleep significantly after sunrise. However, surprisingly, MSFscdid not correlate with daily light intensity at the different geographical locations. Although these findings appear to contradict earlier studies suggesting that in the wider population increased light exposure is associated with an earlier chronotype, our findings are derived exclusively from a student population aged between 17 and 26 years. We therefore suggest that the age and occupation of our population increase the likelihood that these individuals will experience relatively little light exposure in the morning whilst encountering more light exposure later in the day, when light has a delaying effect upon the circadian system

    Risk of non-Hodgkin lymphoma associated with occupational exposure to solvents,metals, organic dusts and PCBs (Australia)

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    Objective: Several studies have suggested that there is an occupational component to the causation of non-Hodgkin lymphoma (NHL). We aimed to use accurate means to assess occupational exposures to solvents, metals, organic dusts and polychlorinated biphenyls (PCBs) in a case-control study. Methods: Cases were incident NHLs during 2000 and 2001 in two regions of Australia. Controls were randomly selected from the electoral roll and frequency matched to cases by age, sex and region. A detailed occupational history was taken from each subject. For jobs with likely exposure to the chemicals of interest, additional questions were asked by telephone interview using modified job specific modules. An expert allocated exposures using the information in the job histories and the interviews. Odds ratios were calculated for each exposure adjusting for age, sex, region and ethnic origin. Results: 694 cases and 694 controls (70% and 45% respectively of those potentially eligible) participated. The risk of NHL was increased by about 30% for exposure to any solvent with a dose response relationship, subgroup analysis showed the finding was restricted to solvents other than benzene. Exposure to wood dust also increased the risk of NHL slightly. Exposures to other organic dusts, metals, and PCBs were not strongly related to NHL. Conclusions: The risk of NHL appears to be increased by exposure to solvents other than benzene and possibly to wood dust

    MASSART-PIÉRARD, Françoise. La langue : Vecteur d'organisation internationale. Louvain-la-Neuve, Éditions d'Acadie, 1995, 194 v.

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    Gait and balance training is an essential ingredient for locomotor rehabilitation of patients with neurological impairments. Robotic overhead support systems may help these patients train, for example by relieving them of part of their body weight. However, there are only very few systems that provide support during overground gait, and these suffer from limited degrees of freedom and/or undesired interaction forces due to uncompensated robot dynamics, namely inertia. Here, we suggest a novel mechanical concept that is based on cable robot technology and that allows three-dimensional gait training while reducing apparent robot dynamics to a minimum. The solution does not suffer from the conventional drawback of cable robots, which is a limited workspace. Instead, displaceable deflection units follow the human subject above a large walking area. These deflection units are not actuated, instead they are implicitly displaced by means of the forces in the cables they deflect. This leads to an underactuated design, because the deflection units cannot be moved arbitrarily. However, the design still allows accurate control of a three-dimensional force vector acting on a human subject during gait. We describe the mechanical concept, the control concept, and we show first experimental results obtained with the device, including the force control performance during robot-supported overground gait of five human subjects without motor impairments
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