Simulated hyperopic anisometropia and reading, visual information processing, and reading-related eye movement performance in children.

Purpose: This study investigated the impact of simulated hyperopic anisometropia and sustained near work on performance of academic-related measures in children.
Methods: Participants included 16 children (mean age: 11.1 ± 0.8 years) with minimal refractive error. Academic-related outcome measures included a reading test (Neale Analysis of Reading Ability), visual information–processing tests (Coding and Symbol Search subtests from the Wechsler Intelligence Scale for Children), and a reading-related eye movement test (Developmental Eye Movement test). Performance was assessed with and without 0.75 diopters of simulated monocular hyperopic defocus (administered in a randomized order), before and after 20 minutes of sustained near work. Unilateral hyperopic defocus was systematically assigned to either the dominant or nondominant sighting eye to evaluate the impact of ocular dominance on any performance decrements.
Results: Simulated hyperopic anisometropia and sustained near work both independently reduced performance on all of the outcome measures (P < 0.001). A significant interaction was also observed between simulated anisometropia and near work (P < 0.05), with the greatest decrement in performance observed during simulated anisometropia in combination with sustained near work. Laterality of the refractive error simulation (ocular dominance) did not significantly influence the outcome measures (P > 0.05). A reduction of up to 12% in performance was observed across the range of academic-related measures following sustained near work undertaken during the anisometropic simulation.
Conclusions: Simulated hyperopic anisometropia significantly impaired academic-related performance, particularly in combination with sustained near work. The impact of uncorrected habitual anisometropia on academic-related performance in children requires further investigation. © 2014 The Association for Research in Vision and Ophthalmology, Inc.

Leadership and teamwork in medical emergencies: Performance of nursing students and registered nurses in simulated patient scenarios

Aims and objectives: To examine nursing students' and registered nurses' teamwork skills whilst managing simulated deteriorating patients. Background: Studies continue to show the lack of timely recognition of patient deterioration. Management of deteriorating patients can be influenced by education and experience. Design: Mixed methods study conducted in two universities and a rural hospital in Victoria, and one university in Queensland, Australia. Methods: Three simulation scenarios (chest pain, hypovolaemic shock and respiratory distress) were completed in teams of three by 97 nursing students and 44 registered nurses, equating to a total of 32 student and 15 registered nurse teams. Data were obtained from (1) Objective Structured Clinical Examination rating to assess performance; (2) Team Emergency Assessment Measure scores to assess teamwork; (3) simulation video footage; (4) reflective interview during participants' review of video footage. Qualitative thematic analysis of video and interview data was undertaken. Results: Objective structured clinical examination performance was similar across registered nurses and students (mean 54% and 49%); however, Team Emergency Assessment Measure scores differed significantly between the two groups (57% vs 38%, t = 6·841, p < 0·01). In both groups, there was a correlation between technical (Objective Structured Clinical Examination) and nontechnical (Team Emergency Assessment Measure) scores for the respiratory distress scenario (student teams: r = 0·530, p = 0·004, registered nurse teams r = 0·903, p < 0·01) and hypovolaemia scenario (student teams: r = 0·534, p = 0·02, registered nurse teams: r = 0·535, p = 0·049). Themes generated from the analysis of the combined quantitative and qualitative data were as follows: (1) leadership and followership behaviours; (2) help-seeking behaviours; (3) reliance on previous experience; (4) fixation on a single detail; and (5) team support. Conclusions: There is scope to improve leadership, team work and task management skills for registered nurses and nursing students. Simulation appears to be beneficial in enabling less experienced staff to assess their teamwork skills. Relevance to clinical practice: There is a need to encourage less experienced staff to become leaders and for all staff to develop improved teamwork skills for medical emergencies.

The impact of sleep restriction while performing simulated physical firefighting work on cortisol and heart rate responses

PURPOSE: Physical work and sleep restriction are two stressors faced by firefighters, yet the combined impact these demands have on firefighters' acute stress responses is poorly understood. The purpose of the present study was to assess the effect firefighting work and sleep restriction have on firefighters' acute cortisol and heart rate (HR) responses during a simulated 3-day and 2-night fire-ground deployment. METHODS: Firefighters completed multiple days of simulated physical work separated by either an 8-h (control condition; n = 18) or 4-h sleep opportunity (sleep restriction condition; n = 17). Salivary cortisol was sampled every 2 h, and HR was measured continuously each day. RESULTS: On day 2 and day 3 of the deployment, the sleep restriction condition exhibited a significantly higher daily area under the curve cortisol level and an elevated cortisol profile in the afternoon and evening when compared with the control condition. Firefighters' HR decreased across the simulation, but there were no significant differences found between conditions. CONCLUSION: Findings highlight the protective role an 8-h sleep opportunity between shifts of firefighting work has on preserving normal cortisol levels when compared to a 4-h sleep opportunity which resulted in elevated afternoon and evening cortisol. Given the adverse health outcomes associated with chronically high cortisol, especially later in the day, future research should examine how prolonged exposure to firefighting work (including restricted sleep) affects firefighters' cortisol levels long term. Furthermore, monitoring cortisol levels post-deployment will determine the minimum recovery time firefighters need to safely return to the fire-ground.

Optimisation of nonlinear motion cueing algorithm based on genetic algorithm

Motion cueing algorithms (MCAs) are playing a significant role in driving simulators, aiming to deliver the most accurate human sensation to the simulator drivers compared with a real vehicle driver, without exceeding the physical limitations of the simulator. This paper provides the optimisation design of an MCA for a vehicle simulator, in order to find the most suitable washout algorithm parameters, while respecting all motion platform physical limitations, and minimising human perception error between real and simulator driver. One of the main limitations of the classical washout filters is that it is attuned by the worst-case scenario tuning method. This is based on trial and error, and is effected by driving and programmers experience, making this the most significant obstacle to full motion platform utilisation. This leads to inflexibility of the structure, production of false cues and makes the resulting simulator fail to suit all circumstances. In addition, the classical method does not take minimisation of human perception error and physical constraints into account. Production of motion cues and the impact of different parameters of classical washout filters on motion cues remain inaccessible for designers for this reason. The aim of this paper is to provide an optimisation method for tuning the MCA parameters, based on nonlinear filtering and genetic algorithms. This is done by taking vestibular sensation error into account between real and simulated cases, as well as main dynamic limitations, tilt coordination and correlation coefficient. Three additional compensatory linear blocks are integrated into the MCA, to be tuned in order to modify the performance of the filters successfully. The proposed optimised MCA is implemented in MATLAB/Simulink software packages. The results generated using the proposed method show increased performance in terms of human sensation, reference shape tracking and exploiting the platform more efficiently without reaching the motion limitations.

The impact of sleep restriction and simulated physical firefighting work on acute inflammatory stress responses

OBJECTIVES: This study investigated the effect restricted sleep has on wildland firefighters' acute cytokine levels during 3 days and 2 nights of simulated physical wildfire suppression work. METHODS: Firefighters completed multiple days of physical firefighting work separated by either an 8-h (Control condition; n = 18) or 4-h (Sleep restriction condition; n = 17) sleep opportunity each night. Blood samples were collected 4 times a day (i.e., 06:15, 11:30, 18:15, 21:30) from which plasma cytokine levels (IL-6, IL-8, IL-1β, TNF-α, IL-4, IL-10) were measured. RESULTS: The primary findings for cytokine levels revealed a fixed effect for condition that showed higher IL-8 levels among firefighters who received an 8-h sleep each night. An interaction effect demonstrated differing increases in IL-6 over successive days of work for the SR and CON conditions. Fixed effects for time indicated that IL-6 and IL-4 levels increased, while IL-1β, TNF-α and IL-8 levels decreased. There were no significant effects for IL-10 observed. CONCLUSION: Findings demonstrate increased IL-8 levels among firefighters who received an 8-h sleep when compared to those who had a restricted 4-h sleep. Firefighters' IL-6 levels increased in both conditions which may indicate that a 4-h sleep restriction duration and/or period (i.e., 2 nights) was not a significant enough stressor to affect this cytokine. Considering the immunomodulatory properties of IL-6 and IL-4 that inhibit pro-inflammatory cytokines, the rise in IL-6 and IL-4, independent of increases in IL-1β and TNF-α, could indicate a non-damaging response to the stress of simulated physical firefighting work. However, given the link between chronically elevated cytokine levels and several diseases, further research is needed to determine if firefighters' IL-8 and IL-6 levels are elevated following repeated firefighting deployments across a fire season and over multiple fire seasons.

Resistive simulated weightbearing exercise with whole body vibration reduces lumbar spine deconditioning in bed-rest

STUDY DESIGN: Randomized controlled trial. OBJECTIVE: Determine the effectiveness a resistive exercise countermeasure with whole-body vibration in relation to lumbo-pelvic muscle and spinal morphology changes during simulated spaceflight (bed-rest). SUMMARY OF BACKGROUND DATA: Spinal lengthening, flattening of the spinal curves, increases in disc size, and muscle atrophy are commonly seen in spaceflight simulation. This may represent a risk for low back injury. Consideration of exercise countermeasures against these changes is critical for success of long-term spaceflight missions. METHODS: Twenty healthy male subjects underwent 8-weeks of bed-rest with 6-months follow-up and were randomly allocated to an inactive control or countermeasure exercise group. Magnetic resonance imaging of the lumbo-pelvic region was conducted at regular time-points during and after bed-rest. Using uniplanar images at L4, cross-sectional areas of the multifidus, lumbar erector spinae, quadratus lumborum, psoas, anterolateral abdominal, and rectus abdominis muscles were measured. Sagittal scans were used to assess lumbar spine morphology (length, sagittal disc area and height, and intervertebral angles). RESULTS: The countermeasure group exhibited less multifidus muscle atrophy (P = 0.024) and its atrophy did not persist long-term as in the control group (up to 3-months; P < 0.006). Spinal lengthening (P = 0.03) and increases in disc area (P = 0.041) were also reduced. Significant partial correlations (P < 0.001) existed between spinal morphology and muscle cross-sectional area changes. CONCLUSION: The resistive vibration exercise countermeasure reduced, but did not entirely prevent, multifidus muscle atrophy and passive spinal tissue deconditioning during bed-rest. Atrophy of the multifidus muscles was persistent long-term in the inactive subjects. Future work could consider closer attention to spinal posture during exercise and optimizing exercise dose.

Altered response of the anterolateral abdominal muscles to simulated weight-bearing in subjects with low back pain

An important aspect of neuromuscular control at the lumbo-pelvic region is stabilization. Subjects with low back pain (LBP) have been shown to exhibit impairments in motor control of key muscles which contribute to stabilization of the lumbo-pelvic region. However, a test of automatic recruitment that relates to function has been lacking. A previous study used ultrasound imaging to show that healthy subjects automatically recruited the transversus abdominis (TrA) and internal oblique (IO) muscles in response to a simulated weight-bearing task. This task has not been investigated in subjects with LBP. The aim of this study was to compare the automatic recruitment of the abdominal muscles among subjects with and without LBP in response to the simulated weight-bearing task. Twenty subjects with and without LBP were tested. Real-time ultrasound imaging was used to assess changes in thickness of the TrA and internal oblique IO muscles as well as lateral movement ("slide") of the anterior fascial insertion of the TrA muscle. Results showed that subjects with LBP showed significantly less shortening of the TrA muscle (P < 0.0001) and greater increases in thickness of the IO muscle (P = 0.002) with the simulated weight-bearing task. There was no significant difference between groups for changes in TrA muscle thickness (P = 0.055). This study provides evidence of changes in motor control of the abdominal muscles in subjects with LBP. This test may provide a functionally relevant and non-invasive method to investigate the automatic recruitment of the abdominal muscles in people with and without LBP.

Decision making after 50 days of simulated weightlessness

By restricting physical activity levels, the bed rest simulation of weightlessness could be associated with changes in prefrontal cortex functioning that manifest as cognitive decrements, particularly for executive cognitive functions. We aimed to determine if performance on an executive function task was indeed affected by bed rest. The Iowa Gambling Task, a card game measuring real-life decision making processes, was administered to 25 healthy males (aged 21-45 years) selected to undergo 60 days of 6 degrees head-down tilt bed rest for the 2nd Berlin BedRest Study (BBR2-2). Testing was conducted either 6 days before beginning bed rest (n=13) or on the 51st day of bed rest (n=12). The task performance scores of subjects tested before bed rest were not significantly different from those tested during bed rest. However, subjects tested during bed rest failed to adapt their card selection strategy as the Iowa Gambling Task progressed. This was unlike the subjects tested before bed rest, who switched between decks on consecutive card selections less frequently in latter stages of the task. An influence of prolonged bed rest on decision making could have implications for the planning of human spaceflights to Mars, or for any circumstance in which adequate physical activity levels are not achieved.

WISE-2005: bed-rest induced changes in bone mineral density in women during 60 days simulated microgravity

To better understand the effects of prolonged bed-rest in women, 24 healthy women aged 25 to 40 years participated in 60-days of strict 6° head-down tilt bed-rest (WISE-2005). Subjects were assigned to either a control group (CON, n=8) which performed no countermeasure, an exercise group (EXE, n=8) undertaking a combination of resistive and endurance training or a nutrition group (NUT, n=8), which received a high protein diet. Using peripheral quantitative computed tomography (pQCT) and dual X-ray absorptiometry (DXA), bone mineral density (BMD) changes at various sites, body-composition and lower-leg and forearm muscle cross-sectional area were measured up to 1-year after bed-rest. Bone loss was greatest at the distal tibia and proximal femur, though losses in trabecular density at the distal radius were also seen. Some of these bone losses remained statistically significant one-year after bed-rest. There was no statistically significant impediment of bone loss by either countermeasure in comparison to the control-group. The exercise countermeasure did, however, reduce muscle cross-sectional area and lean mass loss in the lower-limb and also resulted in a greater loss of fat mass whereas the nutrition countermeasure had no impact on these parameters. The findings suggest that regional differences in bone loss occur in women during prolonged bed-rest with incomplete recovery of this loss one-year after bed-rest. The countermeasures as implemented were not optimal in preventing bone loss during bed-rest and further development is required.

Managing women with acute physiological deterioration: student midwives performance in a simulated setting

OBJECTIVE: Midwives' ability to manage maternal deterioration and 'failure to rescue' are of concern with questions over knowledge, clinical skills and the implications for maternal morbidity and, mortality rates. In a simulated setting our objective was to assess student midwives' ability to assess, and manage maternal deterioration using measures of knowledge, situation awareness and skill, performance. METHODS: An exploratory quantitative analysis of student performance based upon performance, ratings derived from knowledge tests and observational ratings. During 2010 thirty-five student, midwives attended a simulation laboratory completing a knowledge questionnaire and two video, recorded simulated scenarios. Patient actresses wearing a 'birthing suit' simulated deteriorating, women with post-partum and ante-partum haemorrhage (PPH and APH). Situation awareness was, measured at the end of each scenario. Applicable descriptive and inferential statistical tests were, applied to the data. FINDINGS: The mean total knowledge score was 75% (range 46-91%) with low skill performance, means for both scenarios 54% (range 39-70%). There was no difference in performance between the scenarios, however performance of key observations decreased as the women deteriorated; with significant reductions in key vital signs such as blood pressure and blood loss measurements. Situation, awareness scores were also low (54%) with awareness decreasing significantly (t(32)=2.247, p=0.032), in the second and more difficult APH scenario. CONCLUSION: Whilst knowledge levels were generally good, skills were generally poor and decreased as the women deteriorated. Such failures to apply knowledge in emergency stressful situations may be resolved by repetitive high stakes and high fidelity simulation.

The impact of an authentic, simulated learning activity on student preparedness for work-integrated learning

Student preparation for work-integrated learning using simulated learning experiences is an under researched field in occupational therapy. In 2013 the Deakin University occupational therapy degree introduced a simulated learning experience for students aimed at preparing them for work-integrated learning experiences. The session gave students an opportunity to practice fundamental skills of the discipline. A Likert scale survey was written and critically reviewed by the authors. Students rated the extent to which they felt that they could communicate effectively, build rapport, safely transfer clients, apply occupational health and safety principles and write case notes, prior to and after participation in the simulated learning experience. A statistically significant improvement was found for all outcomes measured. Students also reported improved confidence and valued opportunities to practice and receive feedback on skills. The results demonstrate that participation in a simulated learning activity improves confidence and skills in a range of areas that are relevant to work-integrated learning placement.

Acute psychophysiological relationships between mood, inflammatory and cortisol changes in response to simulated physical firefighting work and sleep restriction

This study examined how changes in wildland firefighters' mood relate to cytokine and cortisol levels in response to simulated physical firefighting work and sleep restriction. Firefighters completed 3 days of simulated wildfire suppression work separated by an 8-h (control condition; n = 18) or 4-h sleep opportunity (sleep restriction condition; n = 17) each night. Firefighters' mood was assessed daily using the Mood Scale II and Samn-Perelli fatigue scale. Participants also provided samples for the determination of salivary cortisol and pro- (IL-6, IL-8, IL-1β, TNF-α) and anti-inflammatory (IL-4, IL-10) cytokine levels. An increase in the positive mood dimension Happiness was related to a rise in IL-8 and TNF-α in the sleep restriction condition. A rise in the positive mood dimension Activation among sleep restricted firefighters was also related to higher IL-6 levels. An increase in the negative mood dimension Fatigue in the sleep restriction condition was associated with increased IL-6, TNF-α, IL-10 and cortisol levels. In addition, an increase in Fear among sleep restricted firefighters was associated with a rise in TNF-α. Elevated positive mood and immune activation may reflect an appropriate response by the firefighters to these stressors. To further understand this relationship, subsequent firefighting-based research is needed that investigates whether immune changes are a function of affective arousal linked to the expression of positive moods. Positive associations between negative mood and inflammatory and cortisol levels to physical work and restricted sleep provide useful information to fire agencies about subjective fire-ground indicators of physiological changes.

Relationships between inflammatory cytokine and cortisol responses in firefighters exposed to simulated wildfire suppression work and sleep restriction

The interplay between inflammatory and cortisol responses modulates an appropriate response to a stressor. Exposure to severe stressors, however, may alter the actions and relationships of these responses and contribute to negative health outcomes. Physical work and sleep restriction are two stressors faced by wildland firefighters, yet their influence on the relationship between inflammatory and cortisol responses is unknown. The aim of the present study was to quantify the relationship between the cytokine and cortisol responses to sleep restriction while performing simulated physical wildfire suppression work. Firefighters completed 3 days of simulated physical firefighting work separated by either an 8-h (Control condition; n = 18) or 4-h sleep (Sleep restriction condition; n = 17) opportunity on each of the two nights. Salivary cortisol and inflammatory cytokines (IL-6, IL-8, IL-1β, TNF-α, IL-4, and IL-10) were measured throughout each day. An increase in morning IL-6 was related to a rise (6.2%, P = 0.043) in evening cortisol among firefighters in the sleep restriction condition. Higher morning IL-6 levels were related to increased (5.3%, P = 0.048) daily cortisol levels, but this relationship was not different between conditions. Less pronounced relationships were demonstrated between TNF-α, IL-10, IL-4, and cortisol independent of the sleep opportunity, but relationships did not persist after adjusting for demographic factors and other cytokines. These findings quantify the relationship between cytokine and cortisol responses among wildland firefighters exposed to simulated occupational stressors. Potential disturbances to the IL-6 and cortisol relationship among sleep-restricted firefighters' supports further investigations into the negative health effects related to possible imbalances between these systems.

The driving force of government in promoting BIM implementation

The adoption of Building Information Modelling (BIM) is one of the greatest technological innovations in the construction industry to date. However, the implementation of BIM lags far behind its potential due to the existence of various barriers. Strong government support is critical for the successful development and deployment of complex technology systems. BIM could seek government support to drive its implementation process and overcome the barriers. Through a survey, this paper aims to discover stakeholders’ expectations of the government role in BIM implementation and explores specific ways for governments to promote BIM implementation. The research findings are expected to assist related departments to accelerate BIM implementation.

Corrosion protection afforded by praseodymium conversion film on Mg alloy AZNd in simulated biological fluid studied by scanning electrochemical microscopy

Surface passivation of AZNd Mg alloy with Pr(NO3)3 is studied using scanning electrochemical microscopy (SECM) in surface generation/tip collection (SG/TC) and AC modes. Corrosion protection afforded by the Pr treatment and the degradation mechanism in a simulated biological environment was examined on a local scale and compared with non-treated AZNd. SG/TC mode results revealed a drastic decrease in H2 evolution due to the Pr treatment. Mapping the local insulating characteristics using AC-SECM showed higher conductivity of the surface where H2 evolution was most favorable.