Concept of Evidence and the Quality of Evidence-Based Reasoning in Elementary Students

The present study has two goals: to explore elementary students’ understanding of evidence and the ways they deploy it to construct arguments, and to examine whether eliciting their concept of evidence during argumentation improves students’ evidence-based reasoning. Individual semi-structured interviews were conducted with 4th and 6th graders (N?=?66) in a public school in Mexico. We found significant differences between groups regarding the concept of evidence, with better performance in the older group. A positive correlation between the concept of evidence and the quality of evidence-based reasoning was found. Also, three performance profiles were observed after eliciting the concept of evidence when grade was excluded as a factor. Results suggest that the concept of evidence plays an essential role in developing argumentative competence in pre-adolescence.

     

The differential effect of team members' trust on team performance: The mediation role of team cohesion

This study examines team performance as affected by various trusting relationships: trust between team members and the team's trust in their direct manager and in top management. Data for the study were collected from a survey of 690 professional elite athletes (belonging to 59 different sports clubs) playing in the regular, top professional Spanish leagues. The model was tested at the team level. Findings reveal that team member trust with respect to the different foci has both a direct and indirect effect on team performance, and that team player trust and cohesion play a mediating role. This study illustrates the dynamic relationship within teams, and, as such, trust among teammates mediates the relationship between trust in the coach as well as team cohesion in determining team performance. The implications for managing teams in other contexts are also evaluated.     

Intrahippocampal wortmannin infusion enhances long-term spatial and contextual memories

The transition from short- to long-term memory involves several biochemical cascades, some of which act in an antagonistic manner. Post-training intrahippocampal administration of wortmannin, a pharmacological inhibitor of phosphatidylinositol 3-kinase, had no effect on memory tested 3 h later, but improved long-term memory tested 48 h following the completion of training. This effect was seen in two hippocampus-dependent tasks: the Morris water maze, using both massed and distributed training paradigms, and contextual fear conditioning. The improvement of long-term memory appears to be the result of enhanced consolidation, as wortmannin had no effect on memory recall. These results are consistent with the hypothesis that memory consolidation involves competing processes, and that blockade of an inhibitory constraint facilitates the consolidation process.     

The behavioral pharmacology of effort-related choice behavior: dopamine, adenosine and beyond

For many years, it has been suggested that drugs that interfere with dopamine (DA) transmission alter the "rewarding" impact of primary reinforcers such as food. Research and theory related to the functions of mesolimbic DA are undergoing a substantial conceptual restructuring, with the traditional emphasis on hedonia and primary reward yielding to other concepts and lines of inquiry. The present review is focused upon the involvement of nucleus accumbens DA in effort-related choice behavior. Viewed from the framework of behavioral economics, the effects of accumbens DA depletions and antagonism on food-reinforced behavior are highly dependent upon the work requirements of the instrumental task, and DA-depleted rats show a heightened sensitivity to response costs, especially ratio requirements. Moreover, interference with accumbens DA transmission exerts a powerful influence over effort-related choice behavior. Rats with accumbens DA depletions or antagonism reallocate their instrumental behavior away from food-reinforced tasks that have high response requirements, and show increased selection of low reinforcement/low cost options. Nucleus accumbens DA and adenosine interact in the regulation of effort-related functions, and other brain structures (anterior cingulate cortex, amygdala, ventral pallidum) also are involved. Studies of the brain systems regulating effort-based processes may have implications for understanding drug abuse, as well as symptoms such as psychomotor slowing, fatigue or anergia in depression and other neurological disorders.     

When Trust in the Leader Matters: The Moderated-Mediation Model of Team Performance and Trust

This study contributes to the sport and team literature by exploring the conditions in which trust in a leader translates into trust in a team and subsequent team performance. Findings from 709 athletes on 74 basketball teams demonstrated that trust in the coach represents a critical antecedent of team trust, especially when the team's past performance has been poor. We also found a combined effect of the level and consensus in trust on team performance. Practical implications suggest that a coach needs to ensure that every player, rather than just some or even the majority of individual team members, trusts him or her and the team.     

Transformational leadership and team performance in sports teams: A conditional indirect model

This study tests how transformational leadership fosters team performance through team cohesion and how that relationship is moderated by previous team performance and leadership consensus. We computed a moderated-mediation model based on a sample of 690 professional players in 59 top professional teams in interactive team sports leagues (basketball, handball, roller hockey, and indoor football/soccer) in Spain. Our findings suggest that transformational leadership indirectly influences objective team performance through the mediation role of team cohesion and that this indirect effect is more prominent when the level of previous performance is higher. We also found that the indirect effect of transformational leadership on team performance via cohesion is stronger in teams with higher consensus regarding their coaches' leadership. Overall, our results demonstrate the importance of integrating dispersion and contextual variables into research models, in particular, previous performance and leadership consensus.     

Schizophrenia and B-lymphocyte alteration--a hypothesis

We studied the immunglobulin synthesis of peripheral blood lymphocytes of healthy blood donors and of patients suffering from acute schizophrenia and endogenous depression. The detection of cytoplasmic immunglobulins was performed by immunofluorescence. The schizophrenic patients showed an increased immunglobulin synthesis without cultivation of lymphocytes, after cultivation for 7 days and after pokeweed mitogen stimulation. This activation of B cells could be the result of disturbances in the prostaglandin formation and activation.