Development of student drivers' self-assessment accuracy during French driver training: Self-assessments compared to instructors' assessments in three risky driving situations

Promoting self-assessment accuracy among student drivers could help improve road safety for young novice drivers (Minimum Requirement for Driving Instructor Training, 2005). It is crucial to investigate the development of this ability in student drivers, although few studies have been conducted on this issue to our knowledge. The present study was aimed at examining the development of accuracy in student drivers’ self-assessments. Students’ self-ratings of their skills were compared to instructors’ ratings based on the students’ progression through the four steps of the French driver training course. The ratings were collected from two versions of an ad hoc questionnaire about students’ ability to turn right, overtake another vehicle, and turn left in driving situations. The questionnaire included a three-part assessment scale (six driving subtasks required to perform the maneuver, the number of driving subtasks managed simultaneously, and the student's autonomy), demographic data, and the students’ progress in the training program. The participants were 149 student drivers (58 men and 91 women) with a mean age of 22.2 years, and 38 professional driving instructors (36 men and 2 women) from 13 driving schools in Paris. The psychometric quality of the scale was satisfactory (α_s > .9) concerning the self-ratings as well as the instructors’ ratings in the three parts of the scale. As a whole and as expected, the self-ratings and the instructors’ ratings became increasingly positive as the training progressed, on each part of the assessment scale. The students’ and the instructors’ ratings did not differ significantly between the three driving situations tested, nor between male and female students in each training step. Furthermore, students’ overestimation of their driving skills was mainly observed on step 1, less on steps 2 and 3, but never on step 4. Thus, the students became rather aware of their current driving skills as the driver training course progressed. The results on the development of the self-assessment accuracy in driver training are discussed.     

Blockade of NMDA receptors 2A subunit in the dorsal striatum impairs the learning of a complex motor skill.

Accumulating evidence proposes that the striatum, known to control voluntary movement, may also play a role in learning and memory. Striatum learning is thought to require long-lasting reorganization of striatal circuits and changes in the strength of synaptic connections during the memorization of a complex motor task. Whether the ionotropic glutamate receptor N-methyl-D-aspartate (NMDAR) contributes to the molecular mechanisms of these memory processes is still unclear. The aim of the present study was to investigate the role of striatal NMDAR and its subunit composition during the learning of the accelerating rotarod task in mice. To this end, we injected directly into the dorsal striatum of mice, via chronically implanted cannula, the NMDAR channel blocker MK-801 as well as the NR2A and NR2B subunit-selective antagonists NVP-AAM077 and Ro 25-6981, respectively, before rotarod training. There was no effect in the motor performances of mice treated with 1.0 μg/side of MK-801, 0.1 μg/side of NVP-AAM077, or 5 and 10 μg/side of Ro 25-6981. In contrast, injections of 2.5 and 5 μg/side of MK-801 or 0.5 and 1 μg/side of NVP-AAM077 impaired motor learning at Day 3 and 8. Interestingly, treatments with MK-801 and NVP-AAM077 did not alter the general motor capacities of mice as revealed by the stepping, wire suspension, and pole tests. Our study demonstrates that the NMDAR of the dorsal striatum contributes to motor learning, especially during the slow acquisition phase, and that NR2A subunits play a critical role in this process. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Invisible wounds, visible savings? Using microsimulation to estimate the costs and savings associated with providing evidence-based treatment for PTSD and depression to veterans of Operation Enduring Freedom and Operation Iraqi Freedom.

This research used microsimulation modeling to estimate the social costs of depression and posttraumatic stress disorder (PTSD) for the 261,827 troops deployed on June 30, 2008, for Operations Enduring Freedom and Iraqi Freedom. Given current standards of care, roughly half of these individuals will be treated for these conditions in the 2 years after they return, and 30% of those treated will receive evidence-based treatment (EBT). Our results suggest that the 2-year social costs of depression and PTSD for this cohort will be $923 million. Policy simulations evaluating the savings associated with universal access to EBT suggest that such access would generate cost savings of $138 million (15%). (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

A meta-analytic review of internalizing, externalizing, and academic adjustment among children of deployed military service members.

Parental deployment during military conflicts has the potential to impact child adjustment. As increased numbers of military Service members have children, it is critical to understand the association between military deployment and child adjustment. In order to resolve inconsistencies in the existing literature, we performed a meta-analytic review of 16 studies that report associations of military deployment with internalizing, externalizing, and academic adjustment among children. Results indicate a small association between deployment and poorer adjustment. This association varied across several features of the studies. Age moderation was such that the associations are strongest in middle childhood and weakest during adolescence. The method that adjustment was assessed also moderated this association, such that maladjustment was evident primarily with parents' reports. Study design also moderated associations, such that comparisons to civilian controls indicated associations with maladjustment, whereas comparisons to nondeployed military and prepost comparisons did not. These findings summarize the existing quantitative literature to indicate that parental deployment has a negligible association with child maladjustment and provide a foundation for future research. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Using age and usage for prediction of reliability of an arbitrary system from a finite population

For single‐use non‐repairable systems, reliability is commonly estimated as a function of age and usage. For the effective management of individual systems or populations of systems, it is frequently important and necessary to predict the reliability in the future for age and usage values not yet observed. When predicting future system reliability, the age of the future system is easily predicted whereas future usage values will typically be unknown. In this paper we present the methodology for how to estimate both individual and population reliability summaries based on the currently known age and usage values. Projected usage values for future points in time can be obtained based on observed usage patterns or user‐specified patterns of usage rates. Individual system summaries can be used to answer the questions ‘For a given system of age A and usage U, what is its reliability with associated uncertainty?’ or ‘For a given system with known current age A and usage U, but unknown usage in the future, what is its reliability with associated uncertainty?’ The population summary of interest predicts the probability that a system randomly selected from the population of systems works. This summary takes into consideration the estimation of future usage, the estimated probability of individual systems working at their given ages and usage values, and the life cycle demographics of the population of interest. In this paper we discuss these questions for a given application. Published in 2010 by John Wiley & Sons, Ltd.     

Characterization of piezocrystals for practical configurations with temperature- and pressure-dependent electrical impedance spectroscopy

Piezoelectric single crystal materials such as (x)Pb(Mg(1/3)Nb(2/3))O(3-)(1-x)PbTiO(3) (PMN-PT) have, by some measures, significantly better performance than established piezoelectric ceramics for ultrasound applications. However, they are also subject to phase transitions affecting their behavior at temperatures and pressures encountered in underwater sonar and actuator applications and in non-destructive testing at elevated temperatures. Materials with modified compositions to reduce these problems are now under development, but application-oriented characterization techniques need further attention. Characterization with temperature variation has been reported extensively, but the range of parameters measured is often limited and the effects of pressure variation have received almost no attention. Furthermore, variation in properties between samples is now rarely reported. The focus of this paper is an experimental system set up with commercially available equipment and software to carry out characterization of piezoelectric single crystals with variation in temperature, pressure, and electrical bias fields found in typical practical use. We illustrate its use with data from bulk thickness-mode PMN-29%PT samples, demonstrating variation among nominally identical samples and showing not only the commonly reported changes in permittivity with temperature for bulk material but also significant and complicated changes with pressure and bias field and additional ultrasonic modes which are attributed to material phase changes. The insight this provides may allow the transducer engineer to accelerate new material adoption in devices.     

Narrow emission linewidths of positioned InAs quantum dots grown on pre-patterned GaAs(100) substrates

We report photoluminescence measurements on a single layer of site-controlled InAs quantum dots (QDs) grown by molecular beam epitaxy (MBE) on pre-patterned GaAs(100) substrates with a 15 nm re-growth buffer separating the dots from the re-growth interface. A process for cleaning the re-growth interface allows us to measure single dot emission linewidths of 80 μeV under non-resonant optical excitation, similar to that observed for self-assembled QDs. The dots reveal excitonic transitions confirmed by power dependence and fine structure splitting measurements. The emission wavelengths are stable, which indicates the absence of a fluctuating charge background in the sample and confirms the cleanliness of the re-growth interface.     

TEM observation of liquid-phase bonded aluminum–silicon/aluminum nitride hetero interface

Liquid-phase bonded aluminum–silicon/aluminum nitride interface structure was investigated using high-resolution transmission electron microscopy. A textured layer of aluminum formed a stable orientation relationship with aluminum nitride, which showed Al(111) to be tilted by about 4° with respect to the AlN(0001) interface plane. The unique orientation relationship between Al and AlN was predicted as one of the stable orientation relationships using coincidence of reciprocal lattice point method, which surveys the degree of geometrical coherency between two crystals in three-dimensional space. A stable orientation relationship was found to be (001)[1_boxclose \bar{1} 0]Al//(2[`2] \bar{2} 03)[11[`2] \bar{2} 0]AlN.