The Red Blood Cell Acetylcholinesterase Levels of Depressive Patients with Suicidal Behavior in an Agricultural Area

Long-term exposure to organophosphate pesticides (OPs) without acute poisoning can lead to various OPs. Environmental exposure to organophosphate pesticides may be associated with depression and suicide attempts in a population living in a rural agricultural area. Patients (n = 149) suffering from major depressive disorder (with and without attempted suicide) and a control group of healthy individuals (n = 64) who had been living in the same rural district for at least 1 year were selected. Red blood cell acetylcholine esterase (RBC-AChE) activity was examined as the basis of evaluating the degree of chronic environmental exposure to OPs residues. There were negative association between RBC-AChE activity levels and suicide attempts, the number of past suicide attempts and hopelessness levels in the depressive patients. The results of the study may support the idea that environmental exposure to OPs may be associated with mental health in individuals living in agricultural districts who are not farmers or working in occupations with access to OPs.     

Activating positive affective experiences in the classroom: “Nice to have” or something more?

This study investigated students’ activating positive affective experiences in mathematics lessons, their antecedents, their cognitive and motivational consequences, as well as their effect on achievement. The participants were 682 Grade 8 and 9 students from 37 classes from Germany and Switzerland who participated in a video study of lessons on the Pythagorean theorem. Control and value beliefs as well as autonomy support proved to be relevant predictors of positive affective experiences. Moreover, positive affective experiences were associated with more cognitive activity during the lessons, which for its part predicted achievement in the posttest. In a follow-up test, there was also an indirect effect of positive affective experiences on achievement, mediated by cognitive activity and expectancy of success.     

Gross efficiency predicts a 6-min double-poling ergometer performance in recreational cross-country skiers

The purpose of the study was to investigate which physiological parameters would most accurately predict a 6-min, all-out, double-poling (DP) performance in recreational cross-country skiers. Twelve male recreational cross-country skiers performed tests consisting of three series lasting 10 s, one lasting 60 s, plus a 6-min, all-out, DP performance test to estimate mean and peak power output. On a separate day, gross mechanical efficiency (GE) was estimated from a 10-min, submaximal, DP test and maximal oxygen consumption (VO₂ max) was estimated from an incremental treadmill running test. Power was measured after each stroke from the acceleration and deceleration of the flywheel that induced the friction on the ergometer. The power was shown to the skier on a small computer placed on the ergometer. A multivariable correlation analysis showed that GE most strongly predicted 6-min DP performance (r = 0.79) and interestingly, neither DP VO₂ max, nor treadmill-running VO₂ max, correlated with 6-min DP performance. In conclusion, GE correlated most strongly with 6-min DP performance and GE at the ski ergometer was estimated to be 6.4 ± 1.1%. It is suggested that recreational cross-country skiers focus on skiing technique to improve gross mechanical efficiency during intense DP.     

The effect of three surface conditions,speed and running experience on vertical acceleration of the tibia during running*

Research has focused on parameters that are associated with injury risk, e.g. vertical acceleration. These parameters can be influenced by running on different surfaces or at different running speeds, but the relationship between them is not completely clear. Understanding the relationship may result in training guidelines to reduce the injury risk. In this study, thirty-five participants with three different levels of running experience were recruited. Participants ran on three different surfaces (concrete, synthetic running track, and woodchip trail) at two different running speeds: a self-selected comfortable speed and a fixed speed of 3.06 m/s. Vertical acceleration of the lower leg was measured with an accelerometer. The vertical acceleration was significantly lower during running on the woodchip trail in comparison with the synthetic running track and the concrete, and significantly lower during running at lower speed in comparison with during running at higher speed on all surfaces. No significant differences in vertical acceleration were found between the three groups of runners at fixed speed. Higher self-selected speed due to higher performance level also did not result in higher vertical acceleration. These results may show that running on a woodchip trail and slowing down could reduce the injury risk at the tibia.