The estimation of vehicle speed and stopping distance by pedestrians crossing streets in a naturalistic traffic environment

The ability to estimate vehicle speed and stopping distance accurately is important for pedestrians to make safe road crossing decisions. In this study, a field experiment in a naturalistic traffic environment was conducted to measure pedestrians’ estimation of vehicle speed and stopping distance when they are crossing streets. Forty-four participants (18–45 years old) reported their estimation on 1043 vehicles, and the corresponding actual vehicle speed and stopping distance were recorded. In the speed estimation task, pedestrians’ performances change in different actual speed levels and different weather conditions. In sunny conditions, pedestrians tended to underestimate actual vehicle speeds that were higher than 40 km/h but were able to accurately estimate speeds that were lower than 40 km/h. In rainy conditions, pedestrians tended to underestimate actual vehicle speeds that were higher than 45 km/h but were able to accurately estimate speeds ranging from 35 km/h to 45 km/h. In stopping distance estimation task, the accurate estimation interval ranged from 60 km/h to 65 km/h, and pedestrians generally underestimated the stopping distance when vehicles were travelling over 65 km/h. The results show that pedestrians have accurate estimation intervals that vary by weather conditions. When the speed of the oncoming vehicle exceeded the upper bound of the accurate interval, pedestrians were more likely to underestimate the vehicle speed, increasing their risk of incorrectly deciding to cross when it is not safe to do so.     

Safety–critical events in everyday cycling – Interviews with bicyclists and video annotation of safety–critical events in a naturalistic cycling study

Research in cycling safety seeks to better understand bicycle-related crashes and injuries. The present naturalistic cycling study contributes to this research by collecting data about bicyclists’ behavior and impressions of safety–critical situations, information unavailable in traditional data sources (e.g., accident databases, observational studies). Naturalistic data were collected from 16 bicyclists (8 female; M = 39.1 years, SD = 11.4 years) who rode instrumented bicycles for two weeks. Bicyclists were instructed to report all episodes in which they felt uncomfortable while riding (subjective risk perception), even if they didn’t fall. After data collection, the bicyclists were interviewed in detail regarding their self-reported safety–critical events. Environmental conditions were also recorded via video (e.g., road surface, weather). In total, 63 safety–critical events (56 non-crashes, 7 crashes) were reported by the bicyclists, mainly due to interactions with other road users – but also due to poorly maintained infrastructure. In low-visibility conditions, vehicle-bicycle and bicycle-bicycle events were the most uncomfortable for the bicyclists. Self-reported pedestrian–bicycle events primarily consisted of pedestrians starting to cross the bicycle path without looking. With one exception, all crashes found in the study belonged to poorly maintained road and infrastructure. In particular, construction work or obstacles in the bicycle path were reported as uncomfortable and annoying by the bicyclists. This study shows how naturalistic data and bicyclists’ interviews together can provide a more informative picture of safety–critical situations experienced by the bicyclist than traditional data sources can.     

The CS-Preexposure Effect in Conditioned Taste-Aversion Learning in Golden Hamsters

In Experiment 1, golden hamsters were injected with either 0.9% saline or the nausea-inducing agent, lithium chloride (LiCL), immediately after consuming a flavored diet that was either novel or familiar. The LiCl-induced aversion was strong in hamsters for which the flavored diet was novel, but no significant aversion was observed in hamsters that were familiar with the flavored diet. In Experiment 2, the strength of the LiCl-induced aversion was related inversely to the amount of conditioned-stimulus (CS) preexposure and directly to the duration of the preexposure-conditioning interval. Thus, although some previous researchers have suggested that hamsters may not demonstrate the CS-preexposure effect in a conditioned taste-aversion paradigm, they clearly did so under the conditions of the present experiments, and moreover, the characteristics of the CS-preexposure effect in hamsters were generally similar to those observed in rats.     

Age-Related Changes in Grip Force and Dynamics of Hand Movement

The authors investigated whether older adults (n = 16; mean age = 65 years) increased grip force to compensate for load force fluctuations during up and down movements more than young adults did (n = 16; mean age = 24 years) and whether older and young adults exhibited similar adaptation of grip force to alterations in friction associated with changes in object surface texture. As previously reported, older adults used a higher level of grip force than young adults during static holding. Increased grip force was observed in the older group during movement. The increase was appropriate to the lower coefficient of friction estimated for the older group. In both groups, grip force was greater with a smooth than with a rough surface (the latter having the higher coefficient of friction) during static holding and during movement. Moreover, grip force modulation was equally well synchronized with load force fluctuation during movement in the two groups. The authors concluded that changes in organization of grip force with age are well adapted to change in hand-object interface properties. Elevated grip force in older adults does not necessarily signify a fundamental change in synchronizing grip force modulation with load force fluctuation.     

Preference for Sex of Child Among Primiparous Women

Primiparous American women (N = 140) were questioned during their third trimester concerning their choice of sex of offspring and their willingness to use sex preselection techniques (if available). Eighty-two women expressed no preference for sex of offspring; of the remaining 58, 33 chose girls and 25 chose boys. Of the 26 women who indicated they would have used preselection technology, 13 chose boys and 13 chose girls. Fifty-three percent of the sample indicated they would not have used preselection techniques; 29% were undecided. These results were at variance with earlier studies that indicated a consistent choice of male firstborns, especially in nonpregnant samples. The discrepancy is discussed in terms of a move from boy preference to no preference and a gradual weakening of societal bias against women.     

The effects of safety behavior availability versus utilization on inhibitory learning during exposure

ABSTRACT

This study re-analyzes data from Sy and colleagues (2011; Behaviour Research and Therapy, 49, 305–314) comparing safety behavior availability (SBA) to safety behavior utilization (SBU) during exposure therapy for claustrophobic concerns. The present investigation assessed differential rates of inhibitory learning (i.e. change in danger expectancy and coping self-efficacy) between SBA and SBU before, during, and after a single-session treatment. Thirty-nine participants with marked claustrophobic fear completed six consecutive 5-minute exposure trials in a claustrophobia chamber. Participants in the SBA condition exhibited more interference with inhibitory learning relative to the SBU condition. Danger expectancy was significantly higher in the SBA group and decreased at a markedly slower rate across exposure trials relative to SBU. Coping self-efficacy was also significantly lower among participants in the SBA condition, although groups demonstrated similar rates of change across trials. Limitations, clinical implications, and future directions are discussed.     

Safety Behaviour Enhances the Acceptability of Exposure

Compulsive washing and contamination fears are among the most common symptoms of obsessive-compulsive disorder (OCD). Research suggests that exposure and response prevention (ERP) is effective for OCD. However, ERP is prone to dropouts and refusals, and a substantial proportion of clients therefore do not receive the care they need. A proposed solution involves the judicious use of safety behaviour to enhance the acceptability of exposure-based interventions. The current study aimed to test this proposed solution. Participants were 70 undergraduate students who completed two exposure exercises for contamination fear, one with safety behaviour and one without. Participants then rated the acceptability of the two exercises. Exposure with safety behaviour (ESB) was rated as significantly more acceptable than ERP. Furthermore, subjective fear ratings were lower and behavioural approach to a series of contaminants was greater in the ESB condition. Results demonstrated the acceptability-enhancing potential of safety behaviour in exposure, and are discussed in terms of both theoretical and practical aspects of safety behaviour, exposure, and evidence-based interventions for anxiety disorders.     

工作要求-资源模型新视角——基于心理社会安全氛围的分析

心理社会安全氛围(Psychosocial safety climate,简称PSC)指员工对组织是否重视员工工作过程中与心理健康和安全相关的政策、规程和行为实践的共同感知和看法.回顾相关研究,对PSC的理论建构、测量方法、效度验证及PSC在工作要求-资源模型(Job Demand-Resource Model,简称JD-R模型)中的作用机制等进行了系统梳理.在此基础上,总结JD-R模型完善的理论贡献与管理启示,并提出PSC理论与测量工具完善、工作要求与工作资源层次匹配、考虑组织外及个人因素、开展本土化研究等未来研究方向.     

Perception of threat and safety at work among employees in the Norwegian ministries after the 2011 Oslo bombing

Background and objectives: Terrorism can heighten fears and undermine the feeling of safety. Little is known, however, about the factors that influence threat and safety perception after terrorism. The aim of the present study was to explore how proximity to terror and posttraumatic stress reactions are associated with perceived threat and safety after a workplace terrorist attack. Design and methods: A cross-sectional questionnaire survey was administered to employees in 14 of 17 Norwegian ministries 9–10 months after the 2011 bombing of the government headquarters in Oslo (n = 3520). Results: About 198 of 1881 employees completing the survey were at work when the bomb exploded. Regression analysis showed that this high-exposed group had elevated perceived threat (β = 0.36; 95% CI = 0.19 to 0.53) and reduced perceived safety (β = ?0.42; 95% CI = ?0.62 to ?0.23) compared to a reference group of employees not at work. After adjusting for posttraumatic stress reactions, however, proximity to the explosion no longer mattered, whereas posttraumatic stress was associated with both high perceived threat (β = 0.55; 95% CI = 0.48 to 0.63) and low perceived safety (β = ?0.71; 95% CI, ?0.80 to ?0.63). Conclusion: Terror-exposed employees feel more threatened and less safe after a workplace terrorist attack, and this is closely linked to elevated levels of posttraumatic stress reactions.     

Substitutes for leadership in anaesthesia teams and their impact on leadership effectiveness

In this study we aim to increase our understanding of leadership in anaesthesia teams by investigating the relationship between substitutes for leadership, leadership behaviour, and team performance in situations with varying levels of routine and standardization. The present study relied on video recordings of 12 anaesthesia teams in a simulated setting with the occurrence of a nonroutine event. Clinical team performance was measured by the speed of adequate team reaction to this event. The leadership behaviours observed were coded either as content oriented (e.g., information transmission) or structuring (e.g., assigning tasks). Results showed that leadership behaviour changed depending upon the level of routine of a situation, the degree of standardization, and, to some extent, on the experience of team members. Leadership tends to be positively related to team performance during nonroutine and low standardized situations but negatively related to team performance in routine and highly standardized situations. Furthermore, leadership is only slightly related to team member experience. This study improves our understanding of influences of substitutes for leadership on successful leadership behaviour in anaesthesia teams. The findings also lead to suggestions for both further research and the enhancement of team leadership in critical care.