The influence of live- vs. video-model presentation on the early acquisition of a new complex coordination

Background: Demonstration is a widely used method in sports teaching and coaching, based on the assumption that it is more beneficial than verbal instructions or trial-and-error methods for skill acquisition. Although in teaching/coaching situations, the demonstration is usually carried out in front of the learners, in a research context, it is most often presented via a video. However, a direct comparison between these two types of model has rarely been undertaken in a motor context.

Purpose: In this study, we aimed to compare the effectiveness of the observation of a live and a videomodel for the early acquisition of a complex judo movement.

Research Design: Participants observed either a live or a videomodel executing the task. After observation, they practised for three minutes taking five trials and then performed it for analysis. This procedure was repeated three times. The form and technique of each participant's execution were evaluated using a technical score.

Main results: The results indicated a significant improvement in the task execution by the end of the practice session. However, this improvement occurred only for the video-model group between the second and third blocks of practice.

Conclusions: The video demonstration seems more effective than the live one for the early acquisition of a completely new complex coordination. This may be due to the simplification of the visual information in the former condition because of its two-dimensionality. This simplification may allow the observer to identify the more key elements that would guide him/her for the subsequent performance of the task.     

The Online Market for Illegal Copies of Magazines: A German Case Study

A few years ago, publishing companies started to sell digital copies of their magazines. This study investigates a consequence of this change: the increasing online trade with illegal copies. We collected data on almost 10,000 issues of German magazines that are illegally offered online. The files are distributed in a three-sided market, in which a small number of platforms bring suppliers of illegal copies, consumers, and advertisers together. The market has been growing rapidly—between 2009 and 2012 by a factor of 10. In contrast to the legal magazine market, the illegal trade mostly concerns IT and consumer electronics magazines.     

Shifting the Perspective of the Research Librarian: A CoResearch Paradigm

This article proposes the coresearch engagement model (CoRE), which addresses how the academic research librarian can become a coresearch partner with any patron. The CoRE model is an interpersonal process and is founded upon the concepts of mutual respect, collaboration, reciprocity, and empowerment. Grounded in Howard Gardner’s multiple intelligences theory, Malcolm Knowles’ andragogical model, and guidelines from the Reference and User Services Association, CoRE has the potential to result in engagement for the librarian and patron. The CoRE model can be utilized in many ways including self-awareness and development for those who need and want to expand their abilities as a research librarian. It provides a theoretical framework and a knowledge base, in addition to giving a context for further development by expanding, comparing the related theories for further research, and implementing various applications suggested by this article.     

Biofunctionalized nanoslits for wash-free and spatially resolved real-time sensing with full target capture

We propose biofunctionalized nanofluidic slits (nanoslits) as an effective platform for real-time fluorescence-based biosensing in a reaction-limited regime with optimized target capture efficiency. This is achieved by the drastic reduction of the diffusion length, thereby a boosted collision frequency between the target analytes and the sensor, and the size reduction of the sensing element down to the channel height comparable to the depletion layer caused by the reaction. Hybridization experiments conducted in DNA-functionalized nanoslits demonstrate the analyte depletion and the wash-free detection ∼10 times faster compared to the best microfluidic sensing platforms. The signal to background fluorescence ratio is drastically increased at lower target concentrations, in favor of low-copy number analyte analysis. Experimental and simulation results further show that biofunctionalized nanoslits provide a simple means to study reaction kinetics at the single-pixel level using conventional fluorescence microscopy with reduced optical depth.     

Effectiveness during ball screens in elite basketball games

Ball screens are one of the most frequently used tactical behaviour in elite basketball games. The aim of the present study was to identify their predictors of success related to time, space, players, and tasks performed. The sample was composed of 818 ball screens corresponding to 20 close games (mean differences in score of 3.1 ± 0.8 points) randomly selected from the playoff games of the Spanish Basketball League (2008–2011). Classification tree analysis (CHAID) was used to analyse which variable or combination of variables, better predicts effectiveness during ball screens. The main results allowed identifying interactions with dribbler actions after the screen and the orientation of the screen on the ball. The results showed no interaction with game quarter and quarter minute temporal-related variables in both analyses. The present findings allow improving coaches’ strategic plans that involve selecting the most appropriate offensive approach when performing ball screens.     

Kinematic,kinetic and EMG analysis of four front crawl flip turn techniques

This study aimed to analyse the kinematic, kinetic and electromyographic characteristics of four front crawl flip turn technique variants. The variants distinguished from each other by differences in body position (i.e. dorsal, lateral, ventral) during rolling, wall support, pushing and gliding phases. Seventeen highly trained swimmers (17.9 ± 3.2 years old) participated in interventional sessions and performed three trials of each variant, being monitored with a 3-D video system, a force platform and an electromyography (EMG) system. Studied variables: rolling time and distance, wall support time, push-off time, peak force and horizontal impulse at wall support and push-off, centre of mass horizontal velocity at the end of the push-off, gliding time, centre of mass depth, distance, average and final velocity during gliding, total turn time and electrical activity of Gastrocnemius Medialis, Tibialis Anterior, Biceps Femoris and Vastus Lateralis muscles. Depending on the variant, total turn time ranged from 2.37 ± 0.32 to 2.43 ± 0.33 s, push-off force from 1.86 ± 0.33 to 1.92 ± 0.26 BW and centre of mass velocity during gliding from 1.78 ± 0.21 to 1.94 ± 0.22 m · s^?1. The variants were not distinguishable in terms of kinematical, kinetic and EMG parameters during the rolling, wall support, pushing and gliding phases.