76 research outputs found

    A multi-factorial model for performance under vibration

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    Whole-body vibration affects drivers and passengers in vehicles. These people could be performing a variety of tasks that could be directly related to the control of the vehicle, or could be something unrelated to the vehicle. There is potential for the exposure to WBV whilst performing a task to adversely affect task performance. This paper uses two case studies to illustrate a model of performance and workload whilst exposed to vibration. It is shown that performance whilst completing a discrete task (Purdue pegboard) is easily affected by vibration, but a continuous task (steering wheel) is unaffected. However, in both cases, the self-reported workload increases with vibration. A model is presented that shows that where there is adaptive capacity of the operator, they are able to compensate for the vibration with greater control but at the cost of workload. However, beyond a coping threshold the performance will degrade

    Effects of horizontal whole-body vibration and standing posture on activity interference

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    Standing people are exposed to whole-body vibration in many environments. This paper investigates the effects of horizontal whole-body vibration and standing posture on task performance. Sixteen participants were exposed to random vibration (up to 4Hz), whilst performing a timed pegboard task in two standing postures. Objective and subjective indicators of performance were used. Time taken to complete the task increased progressively with increases in vibration magnitude; the fore-and-aft posture generally showed greater performance decrements and postural interruptions (>1.0ms-2 r.m.s.) than the lateral. For both postures, performance was better during y-axis vibration than during x-axis vibration. Subjective ratings showed similar trends to time data. Impairments due to dual axis exposure were well predicted using r.s.s. summation calculations based on single axis components. These results indicate that best performance for those standing in moving environments will be achieved if individuals adopt a lateral posture with the most severe vibration in the y-axis

    Overview of recent physics results from the National Spherical Torus Experiment (NSTX)

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    Remission of histiocytic ulcerative colitis in Boxer dogs correlates with eradication of invasive intramucosal Escherichia coli

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    BACKGROUND: Historically, histiocytic ulcerative (HUC) (or granulomatous) colitis of Boxer dogs was considered an idiopathic immune-mediated disease with a poor prognosis. Recent reports of dramatic responses to enrofloxacin and the discovery of invasive Escherichia coli within the colonic mucosa of affected Boxer dogs support an infectious etiology. HYPOTHESIS: Invasive E. coli is associated with colonic inflammation in Boxer dogs with HUC, and eradication of intramucosal E. coli correlates with clinical and histologic remission. ANIMALS: Seven Boxer dogs with HUC. METHODS: Prospective case series. Colonic biopsies were obtained at initial evaluation in 7 dogs, and in 5 dogs after treatment with enrofloxacin. Biopsies were evaluated by standardized histopathology, and fluorescence in situ hybridization (FISH) with probes to eubacteria and E. coli. RESULTS: Intramucosal E. coli was present in colonic biopsies of 7/7 Boxers with HUC. Clinical response was noted in all dogs within 2 weeks of enrofloxacin (7 + or - 3.06 mg/kg q24 h, for 9.5 + or - 3.98 weeks) and was sustained in 6 dogs (median disease-free interval to date of 47 months, range 17-62). FISH was negative for E. coli in 4/5 dogs after enrofloxacin. E. coli resistant to enrofloxacin were present in the FISH-positive dog that relapsed. CONCLUSIONS AND CLINICAL RELEVANCE: The correlation between clinical remission and the eradication of mucosally invasive E. coli during treatment with enrofloxacin supports the causal involvement of E. coli in the development of HUC in susceptible Boxer dogs. A poor response to enrofloxacin treatment might be due to colonization with enrofloxacin-resistant E. coli

    Sleep disturbances may influence lifestyle behaviours in women with self-reported polycystic ovary syndrome

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    Polycystic ovary syndrome (PCOS) is associated with a higher prevalence of sleep disturbances and obesity. Treatment of PCOS includes modifying lifestyle behaviours associated with weight management. However, poor sleep in the non-PCOS population has been associated with poorer lifestyle behaviours. The aim was to investigate whether sleep disturbance confounds or modifies the association between lifestyle factors and PCOS. This was a cross-sectional analysis from the Australian Longitudinal Study on Women’s Health cohort aged 31–36 years in 2009 were analysed (n 6067, 464 PCOS, 5603 non-PCOS). Self-reported data were collected on PCOS, anthropometry, validated modified version of the Active Australia Physical Activity survey, validated FFQ and sleep disturbances through latent class analysis. Women with PCOS had greater adverse sleep symptoms including severe tiredness (P = 0·001), difficulty sleeping (P < 0·001) and restless sleep (P < 0·001), compared with women without PCOS. Women with PCOS also had higher energy consumption (6911 (SD 2453) v. 6654 (SD 2215) kJ, P = 0·017), fibre intake (19·8 (SD 7·8) v. 18·9 (SD 6·9) g, P = 0·012) and diet quality (dietary guidelines index (DGI)) (88·1 (SD 11·6) v. 86·7 (SD 11·1), P = 0·008), lower glycaemic index (50·2 (SD 4·0) v. 50·7 (SD 3·9), P = 0·021) and increased sedentary behaviour (6·3 (SD 2·8) v. 5·9 (SD 2·8) h, P = 0·009). There was a significant interaction between PCOS and sleep disturbances for DGI (P = 0·035), therefore only for women who had adequate sleep was PCOS associated with a higher DGI. For women with poorer sleep, there was no association between PCOS and DGI. The association between PCOS and improved diet quality may only be maintained if women can obtain enough good quality sleep.Christie J. Bennett, Darren R. Mansfield, Lin Mo, Anju E. Joham, Sean W. Cain, Michelle L. Blumfield, Allison M. Hodge, and Lisa J. Mora

    A Data Hiding Method for Image Retargeting

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