In the United States, the proportion of Helicopter Emergency Medical Service (HEMS) fatal accidents remained unchanged despite an overall decreasing accident rate. Previous research showed night HEMS ...operations influenced fatal outcomes. Pilots with <6 yr of HEMS domain task experience (low-DTE) had a higher likelihood of a night operational accident in conditions associated with adverse weather. This study sought to determine whether a difference existed between day and night fatal accident rates and identify influences contributing to night fatal HEMS accidents. Any risk factors identified will be used for a risk analysis to inform future operational safety of the night visual flight rule (VFR) HEMS transport system.
Historical accident data and industry hours were obtained. Both pilot DTE groups (low and high) and mission VFR and instrument flight rule (IFR) capability were identified using data from 32 night VFR operational fatal HEMS accidents. Accidents were stratified by loss of control and controlled flight into terrain, pilot DTE, and flight rule capability. The effectiveness of both DTE groups and both flight rule capabilities were measured using system safety risk analysis techniques.
Night fatal accident rates were statistically different from daytime. Low-DTE pilots and the VFR capability combination had the highest likelihood of night operational nonsurvivable accident.
Low-DTE pilots and the VFR capability were the least effective mission combination to avoid hazardous conditions at night and maintain spatial orientation, respectively. The analysis identified measures to reduce likelihood of night fatal operational accidents.
Since the 1990s, standardized competency to stand trial assessment measures have been developed to improve the reliability and validity of expert assessment and opinion in legal settings. This study ...aimed to meta-analyze the psychometric properties of the four ‘second generation’ assessment tools: the MacCAT-CA, MacCAT-FP, ECST-R and CAST*MR.
A systematic search of published and unpublished studies was undertaken on PsycNet, PubMed, Scopus, Web of Science and Science Direct up until February 2018. Test manuals were sourced and attempts at finding grey literature included contacting study authors and test developers.
Eleven studies were included in the final analysis. The MacCAT-CA, ECST-R and CAST*MR demonstrated acceptable subscale internal consistencies and interrater reliability. The MacCAT-CA and CAST*MR discriminated between competent and incompetent defendants with large effects. The MacCAT-FP had insufficient reliability data and poor discrimination. There was insufficient data to meta-analyze the factor structure, sensitivity, specificity, or effect sizes between types of clinical presentation on any tool.
Very few studies have investigated the psychometric properties of the selected tools. Many studies were excluded for not providing original data or simply re-reporting the psychometric properties stated in test manuals. Whilst the MacCAT-CA and ECST-R have promising psychometric properties, ongoing construct validation is required.
Adverse weather and poor visual cues are common elements in night-time Helicopter Emergency Medical Service (HEMS) operations contributing to spatial disorientation and fatal accidents. Pilots are ...required to make weather-related preflight risk assessments to accept or reject a flight. This study's aim was to develop predictive risk assessment tools based on historical accident data to assist the decision-making process.
We analyzed 32 single-pilot HEMS night-time visual flight rules fatal accidents to identify contributory risk factors. Logistic regression analysis was used to develop prediction nomograms for nonvisual meteorological conditions (non-VMC), cause and nonsurvivable accidents as dependent variables. Risk factors such as temperature dew point spread, elevation difference, and years of HEMS pilot experience, were entered as continuous variables. Flight crew composition, pilot DTE (domain task experience) and flight rule capability, primary missions, and temperature dew point spread were entered as categorical variables. A point scoring matrix transposed model probability to likelihood and consequence severity.
The nomograms correctly predicted the likelihood of entering non-VMC, accident cause, and sustaining a nonsurvivable accident in 75%, 55%, and 94% of cases, respectively. Using data from a recent nonsurvivable HEMS accident, the nomogram estimated a 92% probability (Very Likely) of nonsurvivable accident if visual cues were lost.
These nomograms can provide preflight information to predict the likelihood of adverse safety outcomes occurring during a planned HEMS mission. While further development work is needed, this approach has the potential to improve HEMS operational safety.
Although the use of heterogeneous overlapping drug-eluting stents (DES) is not uncommon in clinical practice, whether the implantation sequences of heterogeneous DES will influence the ...endothelialization or arterial responses differently remains unclear.
Twenty-one rabbits were randomized to receive overlapping stents in the iliac artery for 3 months {distal sirolimus-eluting stent (SES, Cypher™)+proximal paclitaxel-eluting stent (PES, Taxus™) (C+T, n=7), distal Taxus+proximal Cypher (T+C, n=7) and bare metal stent (BMS)+BMS (B+B, n=7)}. Endothelial function was evaluated by the acetylcholine provocation test during follow-up angiography. Histopathological changes in proximal, overlapped, and distal stented segments were evaluated.
Although the overall angiographic outcomes were comparable, late loss (mm) in the distal stented segment was higher in the B+B (0.39±0.07) and C+T (0.40±0.20) than that in the T+C (0.06±0.02) group (p<0.001). The incidence of acetylcholine-induced spasm was higher in the DES groups compared with BMS, regardless of the implantation sequences (85.7% in C+T vs. 14.3% in B+B vs. 71.4% in T+C, p=0.017). Notably, only the distal Cypher implantation group (C+T) had three cases of stent fracture. A histopathological analysis showed that despite similar arterial injury scores, Taxus and Cypher stents had higher inflammatory reactions at the overlapped and distal segments compared with those of BMS.
Despite similar arterial injury, higher inflammatory reactions were observed in overlapping DES segments regardless of the implantation sequence compared with that of BMS. Moreover, DES was associated with impaired endothelial function on the adjacent non-stented segments.
•A pioneering study exploring self-regulatory practices amongst motorcycle riders.•Motorcycle riders were found to be at risk of crash involvement and riding cessation.•Behavioural and psychological ...factors were important contributors to self-regulation.•Interventions should be customised to cater for populations with mixed travel modes.
The ability to drive longer and safely are crucial for many older adults. There is a growing evidence on self-regulatory practices amongst older drivers in developed countries, but limited studies are conducted in developing countries. This study aimed to explore self-regulatory practices amongst older Malaysian car drivers and motorcycle riders.
A cross-sectional study was conducted amongst older adults aged 60 years and above residing in two states located in the west coast of Peninsular Malaysia using a self-administered questionnaire. Stepwise regressions were performed to identify for key factors associated with driving/riding self-regulation and crash involvement. Multilevel modelling was conducted to examine the clustering effect of respondents recruited from the two states.
Six-hundred and thirty-seven respondents completed the questionnaire, with over three-quarters of them still driving/riding at the time of data collection. Physical fitness, behavioural and psychological changes experienced with advancing age were important motivators towards self-regulation. Motorcycle riders were found to be at a higher risk of crash involvement, and they were more prone to cease riding compared to car drivers.
Self-regulatory practices amongst older car drivers and motorcycle riders were found to be different. As such, there is a need to customise evidenced-based approaches to cater for specific age groups and road users, particularly in a developing country like Malaysia, where motorcycle is often considered as an affordable mode of transport and is largely involved in road traffic crashes.
Much of the research on transportation and safe mobility focuses on older adult's thoughts and feelings on driving transition in high-income countries, but there is limited knowledge on this process ...and its consequences in low-and-middle-income countries. Moreover, there is very little understanding of the transition process involving other forms of transport, specifically the motorcycle. This study aimed to understand the process of driving/riding cessation involving former car drivers and former motorcycle riders, including the motivations that act as driving forces influencing the decision to cease driving/riding, challenges faced during the transition, and strategies adopted to adjust to life without driving/riding.
Older Malaysian adults aged 60 years and above who had ceased driving and/or riding were interviewed and responded to questions relating to their decision to stop driving/riding. All interview responses were transcribed verbatim and examined using a thematic approach to identify the factors contributing to this decision.
Five themes and 16 sub-themes were identified: 1 being a driver/rider; 2 making the adjustment; 3 making the decision; 4 experiencing multiple losses; and, 5 coping with transition. Physical, psychological, and social factors were important contributors to driving/riding cessation. Motorcycle riders were at higher risk of road crash and ceased more readily than car drivers. Renewing license, transitioning from riding to driving, and utilising multiple alternative means of transportation were unique coping strategies adopted during post-cessation phase.
The current findings suggest that cessation is a transition outcome of self-regulation and a successful transition requires discovery of safer mobility opportunities beyond driving and riding. These findings provide direction for the development of culturally sensitive policy and interventions by taking into consideration travel mode preferences and distribution in countries with mixed travel modes to assist retiring car drivers and motorcycle riders to maintain mobility and access in safety.
•A pioneering study describing older motorcycle riders' experiences in riding cessation.•Motorcycle riders were at higher risk of road crash and ceased riding more readily than car drivers.•Renewing license was a coping strategy contributing to self-identity and emotional adjustment.•Dual-mode road users reduced crash risk by transitioning from riding to driving.•Combined transportation was a form of self-regulation of driving for dual-mode road users.
We examined whether there were differences in the circadian variation in blood pressure and the morning surge in blood pressure between black and white Africans. Clinic and ambulatory blood pressure ...data obtained from the Sympathetic Activity and Ambulatory Blood Pressure in Africans (SABPA) study was examined (n = 406; 49% black African). Ambulatory blood pressure readings were fitted to a six‐parameter double logistic equation to determine the power and rate of the morning surge in blood pressure. Multiple linear regression analysis was used to examine differences in blood pressure between black and white participants. Clinic and ambulatory blood pressure were higher in black participants throughout the day and night. In those taking medications, blood pressure was less well controlled in black subjects. Despite the higher systolic blood pressure, the day‐night difference estimated by the logistic function was similar in black and white participants. However, the rate of rise and power in the morning surge in blood pressure was lower in black participants. We conclude that black participants of the SABPA study present with higher blood pressure throughout the day and night but have a lower power of the morning surge in blood pressure due to a slower morning rate of increase. Moreover, they had an increased prevalence of undiagnosed hypertension and, in those taking medication, were less likely to have their blood pressure controlled than their white counterparts.
We demonstrate high fidelity repetitive projective measurements of nuclear spin qubits in an array of neutral ytterbium-171 (\(^{171}\)Yb) atoms. We show that the qubit state can be measured with a ...fidelity of 0.995(4) under a condition that leaves it in the state corresponding to the measurement outcome with a probability of 0.993(6) for a single tweezer and 0.981(4) averaged over the array. This is accomplished by near-perfect cyclicity of one of the nuclear spin qubit states with an optically excited state under a magnetic field of \(B=58\) G, resulting in a bright/dark contrast of \(\approx10^5\) during fluorescence readout. The performance improves further as \(\sim1/B^2\). The state-averaged readout survival of 0.98(1) is limited by off-resonant scattering to dark states and can be addressed via post-selection by measuring the atom number at the end of the circuit, or during the circuit by performing a measurement of both qubit states. We combine projective measurements with high-fidelity rotations of the nuclear spin qubit via an AC magnetic field to explore several paradigmatic scenarios, including the non-commutivity of measurements in orthogonal bases, and the quantum Zeno mechanism in which measurements "freeze" coherent evolution. Finally, we employ real-time feedforward to repetitively deterministically prepare the qubit in the \(+z\) or \(-z\) direction after initializing it in an orthogonal basis and performing a projective measurement in the \(z\)-basis. These capabilities constitute an important step towards adaptive quantum circuits with atom arrays, such as in measurement-based quantum computation, fast many-body state preparation, holographic dynamics simulations, and quantum error correction.
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