Effects of nicotinamide adenine dinucleotide hydride on physical and mental performance     

Antti Mero  Riikka Raitanen  Joerg Birkmayer  Paavo Komi 《Journal of sports sciences》2013,31(3):311-319

Abstract

The aim of this study was to assess the effects of nicotinamide adenine dinucleotide hydride (NADH) on maximal oxygen uptake ([Vdot]O_2max), maximal anaerobic running time, and mental performance. Eight men were exposed to a supplement treatment (30 mg NADH as ENACHI tablets per day) and to a placebo treatment, each of 4 weeks' duration, in a balanced, double-blind, and cross-over design. The two treatments were separated by a 14-week wash-out period. The results indicated that [Vdot]O_2max, maximal anaerobic running time, and the ability to concentrate were similar in the NADH and placebo conditions. There were also no differences in blood lactate, creatine kinase, reaction time or feelings of fatigue between the treatments. A counter-movement jump performed at rest and 2 min after the aerobic test differed significantly (P ≤ 0.05) between the treatment conditions and was higher in the NADH group. In conclusion, the NADH supplementation for 4 weeks had no effects on [Vdot]O_2max, maximal anaerobic running time or mental performance.  相似文献   

Relative age effects in professional German soccer: A historical analysis     

Stephen P. Cobley  Joerg Schorer  Joseph Baker 《Journal of sports sciences》2013,31(14):1531-1538

Abstract

Relative age effects (RAEs) refer to the specific selection, participation and attainment (dis)advantages which occur as a result of physical and cognitive differences within annual age-grouped cohorts. The present study tracked the existence of RAEs in professional German soccer by examining RAEs in players, head coaches and referees who represented professional soccer clubs or officiated in the Bundesliga from 1963/64 to 2006/07. An additional objective was to consider the social-cultural mechanisms responsible for RAEs, so for a similar period, population and soccer participation information was also obtained. When players were categorised into half decade groups, chi-square analyses predominantly showed RAEs across the history of the Bundesliga, irrespective of dates used for annual age grouping in junior/youth soccer. RAEs were also apparent for head coaches but not for referees. Participation data indicated consistent and progressive growth from 1950 to 1990. RAEs influence the likelihood of attaining professional player and coaching status in German soccer. With many coaches being former players, inequalities associated with annual age-grouping appear to extend beyond a playing career. Officiating was not affected, with referees suggested to emerge from an alternative development pathway. Increased popularity of soccer may have propagated RAEs over time, through intensification of competition and selection mechanisms.  相似文献   

Effectiveness of experiential learning in improving cognitive Planning and its impact on problem solving and mathematics performance / Eficacia del aprendizaje experiencial para mejorar la Planificación cognitiva y su repercusión en la resolución de problemas y el rendimiento matemático     

Silvia Mayoral-Rodríguez  Carme Timoneda-Gallart  Frederic Pérez-Álvarez 《Cultura y Educación》2018,30(2):308-337

This study is based on PASS theory, which suggests that the cognitive process of Planning is responsible for developing metacognitive strategies. The aim is to verify the effect of stimulating the cognitive process of PASS Planning on secondary school students using two different methodologies, with experiential learning (inductive) being applied in one group and deductive learning in the other. The study also aims to verify if improvements are observed in student grades in maths and problem solving. A quantitative study with a quasi-experimental design was carried out with two experimental groups of 59 and 57 students and a control group of 57. The results confirm significant improvements in both experimental groups in relation to their capacity to plan after the stimulations sessions, regardless of the methodology used. Nevertheless, improved grades in maths and problem solving were only found in the group who were administered the experiential learning (inductive) method. The conclusion drawn is that these kinds of methodologies need to be promoted for the stimulation of Planning to have the desired effect on mathematics performance.  相似文献   

The international exchange programme of the University of Hamburg     

Joerg Lippert 《European Journal of Engineering Education》1981,6(3-4):199-202

Universities, just as much as towns and cities, are increasingly establishing strong relations with their counterparts abroad. There are now more than 350 universities which operate exchange schemes with universities in the German Federal Republic, and the most active participant in these exchanges is the University of Hamburg. Like the concept of the twin town, the concept of the “twin university” is a specifically postwar development aiming at the creation of regular and, if possible, contract-regulated relations between two institutions as a contribution to international cooperation in the field of science, the prerequisite of which is a solid mutual understanding.  相似文献   

A six-year monitoring case study of a top-10 cycling Grand Tour finisher     

Julien Pinot  Frederic Grappe 《Journal of sports sciences》2015,33(9):907-914

This study analysed the evolution of the physical potential of a twice top-10 Grand Tour cycling finisher (Tour de France and Vuelta a España) whose training was monitored between the ages of 18 and 23 years. The world-class cyclist’s power output (PO) data and training indices were analysed over six years to determine the evolution of his record power profile and training load (TL), which were estimated by using the session rating of perceived exertion (RPE) method. The total annual duration and TL increased through six seasons by 79% and 83%, respectively. The record POs in all exercise intensity zones improved over the six years. The increases in TL, monotony (+34%) and strain (+162%) from the junior category to the world-class level significantly correlated with an improvement in his aerobic potential, which was characterised by an increase in the record POs between 5 min and 4 h. This case study of the performance level and training parameters of a world-class cyclist provides comprehensive insight into the evolution of a cyclist to the top level. Furthermore, determining the record power profile of this athlete over six competitive seasons illuminates the maturation of the physical potential of a top-10 Grand Tour finisher.  相似文献   

Adolescents' attachment and coping with stress     

Michelle S. Howard  Frederic J. Medway 《Psychology in the schools》2004,41(3):391-402

This study examined how high school students cope with stress as a function of their attachment style. Data were gathered from 75 adolescent–parent pairs in Texas and included measures of attachment, coping style, life stress, and whom the respondent would turn to in times of stress. Adolescents' attachment security was positively related to family communication and negatively related to negative avoidance behaviors such as drinking or using drugs. Attachment insecurity was positively related to negative avoidance. Parent and child attachment ratings were related for secure and preoccupied but not fearful or dismissing styles. Research limitations and implications for school psychologists are discussed. © 2004 Wiley Periodicals, Inc. Psychol Schs 41: 391–402, 2004.  相似文献   

Loudness and Intelligibility of Irrelevant Background Speech Differentially Hinder Children's Short Story Reading     

Giada Guerra  Jurgen Tijms  Anniek Vaessen  Adam Tierney  Frederic Dick  Milene Bonte 《Mind, Brain, and Education》2021,15(1):77-87

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An Exploratory Analysis of Differential Item Functioning and Its Possible Sources in a Higher Education Admissions Context     

Maria Elena Oliveri  Rene Lawless  Frederic Robin  Brent Bridgeman 《教育实用测度》2018,31(1):1-16

We analyzed a pool of items from an admissions test for differential item functioning (DIF) for groups based on age, socioeconomic status, citizenship, or English language status using Mantel-Haenszel and item response theory. DIF items were systematically examined to identify its possible sources by item type, content, and wording. DIF was primarily found in the citizenship group. As suggested by expert reviewers, possible sources of DIF in the direction of U.S. citizens was often in Quantitative Reasoning in items containing figures, charts, tables depicting real-world (as opposed to abstract) contexts. DIF items in the direction of non-U.S. citizens included “mathematical” items containing few words. DIF for the Verbal Reasoning items included geocultural references and proper names that may be differentially familiar for non-U.S. citizens. This study is responsive to foundational changes in the fairness section of the Standards for Educational and Psychological Testing, which now consider additional groups in sensitivity analyses, given the increasing demographic diversity in test-taker populations.  相似文献   

NONINTELLECTUAL LEARNING FACTORS AS DETERMINANTS FOR SUCCESS IN COLLEGE     

Larose  Simon  Robertson  Donald U.  Roy  Roland  Legault  Frederic 《Research in higher education》1998,39(3):275-297

This article presents the results of two studieshypothesizing that nonintellectual learning dispositionsare as important as intellectual assets in predictingthe success of college students. The first study was conducted with a low-risk francophonepopulation (N = 298) and indicated that the Test ofReactions and Adaptation in College (TRAC:nonintellectual dispositions) predicts the collegesuccess of first-year students above and beyond thatpredicted by the high school rank (academicdispositions) and a French-language measure of aptitude(intellectual dispositions). The latter measure added noadditional variation to the high school rank in predictingsuccess. These results were replicated in a second studyconducted with an American student population who wereacademically at risk (N = 179) and using the Scholastic Aptitude Test as a measure ofintellectual dispositions. Findings are discussed interms of their implications for selection, screening,and intervention for first-year collegestudents.  相似文献   

Introducing Bayes     

Joerg Meyer 《Teaching Statistics》2020,42(1):17-21

Some situations are presented with perplexing properties, which become clearer by looking at contingency tables. This in turn leads to problems that can be solved using conditional frequencies and thus leading to the Bayes formula with natural frequencies or probabilities.  相似文献