A Novel Route to Optimize Placement Equipment Kinematics by Coupling Capacitive Accelerometers.

Machine end-effector kinematic analysis is critical to optimizing transporting components where inertial forces are the main loads. While displacements may be measured with relatively high accuracy in transportation equipment motors, the inertial forces in the transported components are seldom optimized. This is especially relevant in electronic component placement systems, where the components have a wide range of configurations (i.e., geometry and mass) and the deployment dimensional/geometric tolerances are remarkably good. The optimization of these systems requires the monitoring of the real position of the accelerometers relative to the measurement point of interest with sufficient accuracy that allows the assembly position to be predicted instantaneously. This study shows a novel method to calibrate this equipment using triaxial accelerometers on a surface mount machine to measure the end-effector accelerations and velocities in its planar motion. The dynamic equations of the system and the method for integration are presented to address the uncertainty on the exact position of the accelerometer sensors relative to the measuring point of interest exist and allow the position correction to optimize response and accuracy.

Work-family conflicts, cognitive appraisal, and burnout: Testing the mediation effect with structural equation modelling.

Work-family conflict constitutes an important source of occupational stress predicting teachers' burnout, and cognitive variables have shown to be core structures in explaining human adaptation to stress. Nevertheless, the role of cognitive appraisal needs to be fully analysed to comprehend how it can mediate the relationship between stress and burnout. In order to understand the potential mediation of cognitive appraisal in the relationship between stress and burnout, we adopted conceptual models of stress that highlighted the value of cognitive appraisal on positive and negative reactions to work demands. Also, we analysed the potential moderation of sex and age in the relationship between work-family conflict, cognitive appraisal, and burnout due to inconsistent findings on how these personal variables can interfere on these relations. In this study, we used structural equation modelling (SEM) to test the mediating of cognitive appraisal in the relationship between work-family conflicts and burnout. A survey with measures of work-family conflicts, cognitive appraisal, and burnout was administered to the participants consisting of 438 Portuguese teachers from kindergarten through high school, aged between 28 and 67 years (M = 46.85; SD = 7.88), 304 of whom were females (69.41%). The results confirmed that cognitive appraisal partially mediated the relationship between work-family conflict and burnout. The mediation effect of cognitive appraisal on the relationship between work-family conflict and burnout was invariant regardless of teachers' sex or age. In sum, cognitive appraisal should be considered in order to understand teachers' adaptation to work.

Effects of Acupuncture on Gait of Patients with Multiple Sclerosis.

BACKGROUND: Multiple sclerosis is considered a complex and heterogeneous disease. Approximately 85% of patients with multiple sclerosis indicate impaired gait as one of the major limitations in their daily life. Acupuncture studies found a reduction of spasticity and improvement of fatigue and imbalance in patients with multiple sclerosis, but there is a lack of studies regarding gait. DESIGN: We designed a study of acupuncture treatment, according to the Heidelberg model of Traditional Chinese Medicine (TCM), to investigate if acupuncture can be a useful therapeutic strategy in patients with gait impairment in multiple sclerosis of relapsing-remitting type. The sample consisted of 20 individuals with diagnosis of multiple sclerosis of relapsing-remitting type. Gait impairment was evaluated by the 25-foot walk test. RESULTS: The results showed differences in time to walk 25 feet following true acupuncture. In contrast, there was no difference in time to walk 25 feet following sham acupuncture. When using true acupuncture, 95% of cases showed an improvement in 25-foot walk test, compared with 45% when sham acupuncture was done. CONCLUSIONS: Our study protocol provides evidence that acupuncture treatment can be an attractive option for patients with multiple sclerosis, with gait impairment.