Influence of football match time–motion parameters on recovery time course of muscle damage and jump ability

ABSTRACT

We analysed the time course of recovery of creatine kinase (CK) and countermovement jump (CMJ) parameters after a football match, and correlations between changes in these variables and match time–motion parameters (GPS-accelerometry) in 15 U-19 elite male players. Plasma CK and CMJ height (CMJ_H), average concentric force (CMJ_CON) and average eccentric force (CMJ_ECC) were assessed 2 h before and 30 min, 24 h and 48 h post-match. There were substantially higher CK levels 30 min, 24 h and 48 h (ES: 0.43, 0.62, 0.40, respectively), post-match. CMJ_ECC (ES: ?0.38), CMJ_H (ES: ?0.35) decreased 30 min post, CMJ_CON (ES: ?0.35), CMJ_ECC (ES: ?0.35) and CMJ_H (ES: ?1.35) decreased 24 h post, and CMJ_CON (ES: ?0.41) and CMJ_H (ES: ?0.53) decreased 48 h post. We found correlations between distance covered at velocities ≤21 km · h^?1 and changes in CK at 24 h (r = 0.56) and at 48 h (r = 0.54) and correlations between CK and distance covered >14 km · h^?1 (r = 0.50), accelerations (r = 0.48), and decelerations (r = 0.58) at 48 h. Changes in CMJ_CON 30 min and 24 h post (both r = ?0.68) correlated with impacts >7.1·G. Decelerations >2 m · s^?2 correlated with changes CMJ_CON (r = ?0.49) at 48 h and CMJ_ECC (r = ?0.47) at 30 min. Our results suggest that match GPS-accelerometry parameters may predict muscle damage and changes in components of neuromuscular performance immediately and 24–48 h post-match.     

Independent Olympic Athletes and the Legitimacy of the International Olympic Committee in Resolving International Conflicts

Abstract

Over the last three centuries (nineteenth, twentieth, and twenty-first) humanity has been facing huge political and ideological conflicts, especially wars. For these reasons, it was seen how necessary it was to create global institutions that aimed to promote peace and reduce or stop conflicts of this magnitude. Therefore, an international institution had already brought on its premises the principles of international peace and reconciliation through sport: the International Olympic Committee (IOC). However, despite bringing together nations around peaceful ties in an international competition, the IOC and the Olympic Games event have always been affected by constant conflicts along their path in the twentieth century, emphasizing issues involving nationalities. Thereby, in a mediator posture of international conflicts and in an effort to reduce the subversions that surrounded it, the IOC, in the 1990s, created the delegation of Independent Olympic Athletes. Such a delegation consists of athletes who cannot represent their respective nationalities at the Olympics due to political factors and/or armament conflicts. This proposal of the IOC demonstrates its posture to avoid, minimize, and even cease ideological and political events that might interfere with the Olympics Games or the athletes participating in them.     

What counts as science? Expansive learning actions for teaching and learning science with bilingual children

Cultural Studies of Science Education - Science education should help children acquire sophisticated understandings about science, how it is done, and how they can be scientists. Consequently,...     

Trajectories of Online Racial Discrimination and Psychological Functioning Among African American and Latino Adolescents

This study investigated trajectories of individual and vicarious online racial discrimination (ORD) and their associations with psychological outcomes for African American and Latinx adolescents in 6th–12th grade (N = 522; M_grade = 9th) across three waves. Data were analyzed using growth mixture modeling to estimate trajectories for ORD and to determine the effects of each trajectory on Wave 3 depressive symptoms, anxiety, and self-esteem. Results showed four individual and three vicarious ORD trajectories, with the majority of participants starting out with low experiences and increasing over time. Older African American adolescents and people who spend more time online are at greatest risk for poor psychological functioning.     

Interactive effects of the probability of the cue and the probability of the outcome on the overestimation of null contingency

Overestimations of null contingencies between a cue, C, and an outcome, O, are widely reported effects that can arise for multiple reasons. For instance, a high probability of the cue, P(C), and a high probability of the outcome, P(O), are conditions that promote such overestimations. In two experiments, participants were asked to judge the contingency between a cue and an outcome. Both P(C) and P(O) were given extreme values (high and low) in a factorial design, while maintaining the contingency between the two events at zero. While we were able to observe main effects of the probability of each event, our experiments showed that the cue- and outcome-density biases interacted such that a high probability of the two stimuli enhanced the overestimation beyond the effects observed when only one of the two events was frequent. This evidence can be used to better understand certain societal issues, such as belief in pseudoscience, that can be the result of overestimations of null contingencies in high-P(C) or high-P(O) situations.     

Acceleration Nation: An Investigation into the Violence of Speed and the Uses of Accidents in Iceland

Abstract

There are two starting points from which this paper is constructed: first, Virilio’s observation that the wealth of societies is founded on their dromocratic condition, that the faster societies accelerate their citizens, commercial goods and communication the more political and economic power they have and, second, the links that he traces between technologies of speed and acceleration and the accident. We suggest that Virilio’s ideas on this invite and deserve a closer ethnographic scrutiny than they have so far received, scrutiny that highlights the varied ways in which speed, acceleration and the accident are articulated in different cultural contexts. To this end we offer an investigation into the dromocratic condition, the violence of speed and the uses of accidents in Iceland.     

Creating a Virtuous Circle of Student Engagement with the Tech Corner

While many academic libraries have followed the public library lead in developing makerspaces, not all libraries have the money or space to dedicate to such large-scale operations. This case study explores a different approach to engaging users with new technology and investigates how to support their creativity without a costly investment in space and staffing. It demonstrates not only how students can be provided a virtual space to explore technology equipment, but also how their opinions can be leveraged for growing the collection and creating training materials.     

Tres pies al gato: significado,sentido y cultura cotidiana en la educación

Resumen

Se pasa revista en este artículo a los tres ejes que conforman la línea de investigación de los autores en psicología de la educación, a saber, considerar la arquitectura, no sólo cognitiva, sino instrumental y cultural, del significado; la necesidad de unir en la investigación y en el diseño educativo las vertientes de significado y de sentido que caracterizan el funcionamiento psicológico de los individuos, y que solo se articulan sobre la base de sistemas de actividad; por último, la necesidad de contemplar las formas de representación humanas menos formalizadas y desdeñadas hasta hace muy poco por la psicología de la educación: las denominadas bajo el epígrafe de conocimiento informal. En torno a estos tres ejes, se exponen ejemplos de investigación y de intervención que conforman lo que hemos denominado diseño cultural.     

Construct Validation of the Self-Efficacy Teaching and Knowledge Instrument for Science Teachers-Revised (SETAKIST-R): Lessons Learned

Described herein is the academic lineage and independent validation of the Self-Efficacy Teaching and Knowledge Instrument for Science Teachers-Revised (SETAKIST-R). Data from 334 K-12 science teachers were analyzed using Partial Credit Rasch models. Principal components analysis on the person-item residuals suggest two latent dimensions: Knowledge and Teaching Self-Efficacies. Item-fit statistics were used to select items for each subscale. Person and item separation (reliability) indices were quite low, and we noted disordered response patterns on the person-item maps that revealed problems with item content and/or scaling for both subscales. These issues include the presence of: verbal negatives, ambiguous modifiers, counter-intuitive scaling, and an “undecided/uncertain” option. The SETAKIST-R, in its current form, cannot be recommended as a measure of science teacher self-efficacy.