Dynamics of expertise level: Coordination in handstand

The aim of the present study was to investigate the effect of expertise on coordination patterns. We thus tested the coordination dynamics of two groups: experts in the handstand also having high expertise in gymnastics and experts in the handstand but only intermediate expertise in gymnastics. All participants were instructed to track a target with their ankles while maintaining the handstand. The target moved on the anterior-posterior axis according to three frequency conditions: 0.2, 0.4 and 0.6 Hz. The results showed that the suprapostural task was performed better by the group with high gymnastics expertise. Moreover, the spontaneous coordination was specific to the level of gymnastics expertise. We concluded that (i) the dynamics of coordination progress with the overall level of expertise in a sport discipline, independently of the mastery of a single skill, (ii) persistence and change are seen in related movement properties, and (iii) high expertise offers greater adaptability relative to the task.     

Automated gait analysis in the open-field test for laboratory mice

In this article, an automated and accurate mouse observation method, based on a conventional test for motor function evaluation, is outlined. The proposed measurement technique was integrated in a regular open-field test, where the trajectory and locomotion of a free-moving mouse were measured simultaneously. The system setup consisted of a transparent cage and a camera placed below it with its lens pointing upward, allowing for images to be captured from underneath the cage while the mouse was walking on the transparent cage floor. Thus, additional information was obtained about the position of the limbs of the mice for gait reconstruction. In a first step, the camera was calibrated as soon as it was fixed in place. A linear calibration factor, relating distances in image coordinates to real-world dimensions, was determined. In a second step, the mouse was located and its body contour segmented from the image by subtracting a previously taken “background” image of the empty cage from the camera image. In a third step, the movement of the mouse was analyzed and its speed estimated from its location in the past few images. If the speed was above a 1-sec threshold, the mouse was recognized to be running, and the image was further processed for footprint recognition. In a fourth step, color filtering was applied within the recovered mouse region to measure the position of the mouse’s paws, which were visible in the image as small pink spots. Paws that were detected at the same location in a number of subsequent images were kept as footprints—that is, paws in contact with the cage floor. The footprints were classified by their position relative to the mouse’s outline as corresponding to the front left or right paw or the hind left or right paw. Finally, eight parameters were calculated from the footprint pattern to describe the locomotion of the mouse: right/left overlap, front/hind base, right/left front limb stride, and right/left hind limb stride. As an application, the system was tested using normal mice and mice displaying pentobarbital-induced ataxia. The footprint parameters measured using the proposed system showed differences of 10% to 20% between normal and ataxic mice.     

Psychometric analysis of the Stunkard-Messick Eating Questionnaire (SMEQ) and Comparison with the dutch Eating Behavior Questionnaire (DEBQ)

The factor structure of the Stunkard-Messick Eating Questionnaire (SMEQ) differs from that of the Dutch Eating Behavior Questionnaire (DEBQ). Using students and members of a weight watchers club, we factor-analyzed responses to the SMEQ and produced a solution which was different from that obtained by Stunkard and Messick, but which had some similarities to the factor structure of the DEBQ. “External” taste items and “internal” hunger items loaded on the same factor, a finding inconsistent with externality theory but consistent with the common sense notion of appetite strength. Although our finding suggests factor instability of the SMEQ, the stability of the DEBQ appears to be the consequence of a restricted range of DEBQ items compared with SMEQ items. Financial support for this research was given by Lilly Industries.     

Normative mid-life concerns among Vietnam veterans with post-traumatic stress disorders: Some preliminary empirical findings

Most Vietnam veterans are now in the mid-life years. Veterans suffering from post-traumatic stress disorder (PTSD) may find that mid-life concerns both precipitate and exacerbate their PTSD symptomatology. Preliminary research with four groups of adult males supports this notion. A cross-sectional study with nonveteans, Vietnam era noncombatants, Vietnam combat veterans not in treatment, and Vietnam veterans in treatment for PTSD suggests that the mid-life issues of affiliation, identity, demonic guilt, and work may be the most problematic. Implications for treatment are discussed.     

Union Influence on Internal Organizational Decisions: An Empirical Analysis

The development of appropriate models of organizational decision making requires a complete determination of the different groups that affect the decision-making process. The present investigation examines the influence of union officials as a group on internal organizational decisions. The rank and file membership of three local unions ( N = 1324) and their first level supervisors ( N = 205) were surveyed regarding the perceived influence of five different groups within the organizational hierarchy. A methodology developed by Tannenbaum (1968) and his associates was modified to include lower-level union representatives as one of five groups who potentially wield influence over organizational decisions. The results of this investigation determined that union representatives are seen as possessing significant levels of influence regarding microlevel organizational decisions. Additional analyses revealed that first-level supervisors believed that union representatives possessed more influence in organizational decisions than they possessed as a group. The implications of these findings and suggestions for future research are discussed.