Fatigue-related changes in the coordination of lifting and their effect on low back load

In this study, changes in movement coordination caused by fatigue that developed during repetitive lifting were examined. Five men performed 6 times a 5-min bout of lifting an 8-kg barbell at 15 lifts/min, using two lifting techniques; one minimized trunk rotation (squat lift), and the other minimized rotation in the knee joint (stoop lift). Kinematics and dynamics were studied by means of movement analysis and inverse dynamics, using a two-dimensional linked segment model. Within-subject variation over repetitive lifts of the time course of joint angles was smaller than between-subjects variation on the first analyzed lift. Relative timing between joint rotations did not change significantly across repetitive lifts, except between knee and hip in the squat lift. No change of the lumbosacral torque over repetitive lifts was found. The adaptability of the neural control appeared to be sufficient to accommodate the strong changes of the input-output characteristics of the muscles caused by fatigue so that an essentially constant performance of the movement act was maintained.     

Turbo Pascal timing routines for the IBM microcomputer family

Two Turbo Pascal (versions 3.0 and 4.0) software timers for the IBM microcomputer family are described: one with a 55-msec resolution and another with a 1-msec resolution. Both can be implemented without additional hardware requirements. The 55-msec timer makes use of the system-time-of-day clock; the 1-msec timer is a Turbo Pascal translation of the timer described by Bührer, Sparrer, and Weitkunat (1987). The logic of each timer is shown by a short demonstration program.     

Career adapt-abilities scale-France form: Psychometric properties and relationships to anxiety and motivation

The CAAS-France Form consists of four scales, each with six items, which measure concern, control, curiosity, and confidence as psychosocial resources for managing occupational transitions, developmental tasks, and work traumas. Internal consistency estimates for the subscale and total scores ranged from moderate to good. The factor structure was quite similar to the one computed for combined data from 13 countries. The CAAS France Form is identical to the International Form 2.0. Concurrent validity evidence was collected relative to motivation and anxiety given that adaptability has been identified as a meta-competency for career construction in information societies. Relations between career adaptability and motivation measures were as predicted. However, they provide partial support to the relations between career adaptability and general or career anxiety.     

Spatial integration under contextual control in a virtual environment

The role of context was examined in the selection and integration of independently learned spatial relationships. Using a dynamic 3D virtual environment, participants learned one spatial relationship between landmarks A and B which was established in one virtual context (e.g., A is left of B) and a different spatial relationship which was established in another virtual context (e.g., A is in front of B). A spatial relationship between B and a goal was then established, using the same landmark-to-goal relationship in each context. When given A in either context at test, participants were more likely to choose a position in expectation of the goal, based on the relationship of A to B previously established in that context. Thus, context can be used to disambiguate conflicting spatial information. This research is discussed in light of Miller and Escobar's (2002) retrieval model.     

The mental representation of the magnitude of symbolic and nonsymbolic ratios in adults

This study mainly investigated the specificity of the processing of fraction magnitudes. Adults performed a magnitude-estimation task on fractions, the ratios of collections of dots, and the ratios of surface areas. Their performance on fractions was directly compared with that on nonsymbolic ratios. At odds with the hypothesis that the symbolic notation impedes the processing of the ratio magnitudes, the estimates were less variable and more accurate for fractions than for nonsymbolic ratios. This indicates that the symbolic notation activated a more precise mental representation than did the nonsymbolic ratios. This study also showed, for both fractions and the ratios of dot collections, that the larger the components the less precise the mental representation of the magnitude of the ratio. This effect suggests that the mental representation of the magnitude of the ratio was activated from the mental representation of the magnitude of the components and the processing of their numerical relation (indirect access). Finally, because most previous studies of fractions have used a numerical comparison task, we tested whether the mental representation of magnitude activated in the fraction-estimation task could also underlie performance in the fraction-comparison task. The subjective distance between the fractions to be compared was computed from the mean and the variability of the estimates. This distance was the best predictor of the time taken to compare the fractions, suggesting that the same approximate mental representation of the magnitude was activated in both tasks.     

Examination of the Hierarchical Structure of the Brief COPE in a French Sample: Empirical and Theoretical Convergences

This study aimed to determine whether the various factors of coping as measured by the Brief COPE could be integrated into a more parsimonious hierarchical structure. To identify a higher structure for the Brief COPE, several measurement models based on prior theoretical and hierarchical conceptions of coping were tested. First, confirmatory factor analysis (CFA) results revealed that the Brief COPE's 14 original factors could be represented more parsimoniously with 5 higher order dimensions: problem-solving, support-seeking, avoidance, cognitive restructuring, and distraction (N = 2,187). Measurement invariance across gender was also shown. Second, results provided strong support for the cross-validation and the concurrent validity of the hierarchical structure of the Brief COPE (N = 584). Results indicated statistically significant correlations between Brief COPE factors and trait anxiety and perceived stress. Limitations and theoretical and methodological implications of these results are discussed.     

The Necklace of Numbers

The necklace of numbers is a symbol that came in one of my dreams at the end of 2006, at the time when I was about to leave France, my native country, and come to the United States. As I was going through the process of becoming an American citizen, I felt compelled to reconnect to my French roots. The result was this personal account which tells the most important dreams that led me to this country. It is also a tale of a mid-life transformation, a tale of an immigrant viewed from inside, and a tale of individuation by following the path of love.