Postural control in children with and without neurofibromatosis type 1

Previous research has evaluated the motor proficiency of children with neurofibromatosis type 1 (NF1) and found delays on the balance subtest. However the balance subtest was found to have low sensitivity for identifying balance impairments. This study examines the differences in postural control between children with NF1 and peers with typical development using a force plate. A single limb stance test on a force plate was completed for all participants. The force plate variables, center of pressure maximum distance in the anterior/posterior direction (COPmax A/P) and center of pressure velocity (COPvel A/P) were compared between groups. The NF1 group’s performance was significantly poorer than the control group in both COPmax A/P (p = .01) and COPvel A/P (p = .01). When separated into specific age ranges, only the children in the NF1 group between 5 and 12 years of age demonstrated statistically significant differences in the COP variables. The COP variables for the 13- to 18-year-old group were not significantly different. These results indicate that young children with NF1 have poor postural control. However, postural control appears to improve with maturation.     

When saying no leads to compliance: The door-in-the-face technique for changing attitudes and behaviors towards smoking at work

IntroductionThe aim of this action research was to encourage workers to comply with an anti-smoking charter and get them to effectively reduce their tobacco use. Two change procedures were compared: a classic one based on an information campaign and an original one based on the door-in-the-face technique.MethodForty-three smoking workers participated in this study. They were assigned to one of the two groups: information campaign group or door-in-the-face group. Two types of measures were administered. The first assessed self-reported attitudes towards smoking, such as perceived dependence (Fagerström Test); the second assessed effective behavior, such as number of cigarettes smoked and physiological nicotine addiction.ConclusionTaken together, the results show that the door-in-the-face technique was more effective than the information campaign. These results are discussed in light of the social acceptability of the initial refusal.     

Reinvestment: Examining convergent,discriminant, and criterion validity using psychometric and behavioral measures

Given scarce external validity available to date concerning the reinvestment construct, the aim of this four-study research project was to further explore the validity of the Movement-Specific Reinvestment Scale and the Decision-Specific Reinvestment Scale, using psychometric and behavioral measures. Study 1 showed that deliberative participants had a higher reinvestment tendency than intuitive participants. Study 2 showed that reinvestment was linked to self-consciousness, rumination, perfectionism, and had satisfactory test–retest reliability. Moreover, it provided some potential insights on the development of reinvestment due to parental criticisms. Study 3 indicated that high decision reinvestors performed worse than their low decision reinvestor counterparts in a visual search task under pressure. Study 4 showed that older participants had a lower reinvestment score, and that reinvestment was associated with higher motor imagery ability, challenging the idea that reinvestment can only be seen as detrimental to performance.     

Re-examining the effects of verbal instructional type on early stage motor learning

The present study investigated the differential effects of analogy and explicit instructions on early stage motor learning and movement in a modified high jump task. Participants were randomly assigned to one of three experimental conditions: analogy, explicit light (reduced informational load), or traditional explicit (large informational load). During the two-day learning phase, participants learned a novel high jump technique based on the ‘scissors’ style using the instructions for their respective conditions. For the single-day testing phase, participants completed both a retention test and task-relevant pressure test, the latter of which featured a rising high-jump-bar pressure manipulation. Although analogy learners demonstrated slightly more efficient technique and reported fewer technical rules on average, the differences between the conditions were not statistically significant. There were, however, significant differences in joint variability with respect to instructional type, as variability was lowest for the analogy condition during both the learning and testing phases, and as a function of block, as joint variability decreased for all conditions during the learning phase. Findings suggest that reducing the informational volume of explicit instructions may mitigate the deleterious effects on performance previously associated with explicit learning in the literature.     

Effects of cementite morphology on short-fatigue-crack propagation in binary Fe–C steel

The effects of cementite morphology on short-fatigue-crack propagation were investigated by subjecting smooth steel specimens to rotating-bending fatigue tests. Intergranular and transgranular cementite precipitation steels free of other phases were prepared through heat treatments. In the intergranular cementite precipitation steel, short-fatigue-crack propagation was decelerated at the grain boundaries, and accelerated in the grain interiors. In contrast, the transgranular precipitation steel showed the deceleration of the crack propagation in the grain interiors but not in the vicinity of the grain boundaries.     

L’intensification du travail,et l’intensification des changements dans le travail : quels enjeux pour les travailleurs expérimentés ?

In this article we address, on the basis of various knowledge in ergonomics, work psychology and work demography, the stakes of a confrontation between two trends in progress: on one side the structural ageing of workforce, on the other side work intensification, and intensification of changes at work. This analyze includes statements on these evolutions by themselves, and a synthesis of knowledge on the difficulties created by the intensification of work, or changes at work, for elderly workers, but also on work strategies that those can elaborate, using their experience, in order to cope with these constraints.     

Taking Racism to Heart: Race-Related Stressors and Cardiovascular Reactivity for Multiracial People

Multiracial people experience an accumulation of racial stress for both their minority and their multiracial identities, yet no research has examined the physiological impact of this stress. This within-groups experimental study examined whether two race-related stressors—identity invalidation and discrimination from family—affect cardiovascular reactivity for Black/White multiracial adults (N = 60). The authors found a Condition × Phase interaction effect indicating that discrimination from family affected blood pressure. Invalidation had no effect on blood pressure. Las personas multirraciales experimentan una acumulación de estrés racial tanto a causa de su identidad multirracial como de su identidad como minoría, pero no hay investigaciones que hayan examinado el impacto psicológico de este estrés. Este estudio experimental dentro de grupos examinó si dos factores causantes de estrés relacionados con la raza (la invalidación de la identidad y la discriminación por parte de la familia) afectan a la reactividad cardiovascular de personas adultas multirraciales blancas/negras (N = 60). Los autores hallaron un efecto de interacción Condición × Fase que indica que la discriminación por parte de la familia tuvo un efecto sobre la presión sanguínea. La invalidación no tuvo efecto sobre la presión sanguínea.     

时间压力下图标语义距离对雷达界面信息工作记忆的影响

本研究分别在无时间压力和有时间压力的条件下,通过两个实验探究了图标语义距离?目标数量以及目标类型对雷达界面信息工作记忆的影响?结果发现无时间压力下图标语义距离在工作记忆的编码提取上没有差异,而有时间压力下,强语义图标相较于弱语义图标在工作记忆的提取上具有优势;且无论是在无时间压力下还是有时间压力下,工作记忆容量最佳为3个目标项;对敌机的提取时长于友机长于不明飞行物?结果表明仅在有时间压力下强语义图标在信息提取上具有优势,验证了工作记忆容量的限制,为雷达界面的设计提供了参考意见?     

Impact of time pressure on acceleration behavior and crossing decision at the onset of yellow signal

This study investigates acceleration behavior and crossing decision of the drivers under increasing time pressure driving conditions. A typical urban route was designed in a fixed-base driving simulator consisting of four signalized intersections with varying time to stop line (4 s and 6 s) and maneuver type (right-turn and go-through). 97 participants’ data were obtained under No Time Pressure (NTP), Low Time Pressure (LTP), and High Time Pressure (HTP) driving conditions. The acceleration behavior was examined at the onset of yellow signal in four ways: continuous deceleration, acceleration-deceleration, deceleration-acceleration, and continuous acceleration. A random forest model was used to build an acceleration behavior prediction model for identifying the significant explanatory variables based on variable importance ranking. Further, a Mixed Effects Multinomial Logit (MEML) model was developed using the explanatory variables obtained from a random forest model. Additionally, a generalized linear mixed model was incorporated for estimating the likelihood of crossing an intersection by considering all the explanatory variables. A MEML model result revealed that the odds of adopting acceleration-deceleration, deceleration-acceleration, and continuous acceleration instead of continuous deceleration increased by 63 %, 123 %, and 77 %, respectively under HTP driving conditions. Moreover, the likelihood of crossing a signalized intersection increased by 2.73 times and 4.26 times when the drivers were under LTP and HTP driving conditions, respectively as compared to NTP driving condition. Apart from this, time to stop line (reference: 6 s) and age showed negative association with crossing probability. Overall, the findings from this study revealed that drivers altered their acceleration behavior for executing risky driving decisions under increasing time pressure driving conditions.