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Supervised classification combined with genetic algorithm variable selection for microplastics measured by infrared spectrometry
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Effects of visual training on motor performance in young tennis players using FitLight trainer
No full textBACKGROUND: Tennis is an open-skill sport in which the athletes have a short period of time to elaborate all the information coming from the surrounding environment and produce a motor answer based on them. The aim of this study was divided in two hypotheses: 1) to assess if belonging to a certain category, athlete, or non-athlete, older or younger, can affect the development of reaction time on children; and 2) if a protocol based on visual training (VT) of 6 weeks could improve the motor performance on the field in young tennis players using FitLight Trainer (Medical Graphics, Milan, Italy). METHODS: In this evidence a group of young children (N.=40) have been tested on light board through reaction test then some young tennis players (N.=15, age: 7-12 years old) were taken as reference for the second hypothesis. They were divided in two groups: 7 of them were in the group Under-10 (U10) while 8 in a second group (U12). They performed a VT protocol once a week for at least 40 minutes for 6 weeks. They were tested at baseline (T0) and follow-up (T6) to evaluate the reaction time, time in specific lateral shift and precision about forehand and backhand. RESULTS: The development of reaction time of the athletes is principally caused by their growth (P<0.05). Principal components analysis (PCA) showed significant improvements in the Under-10 category in all the tests while in the Under-12 category not every individual showed a significant result in terms of performance. CONCLUSIONS: The developing of reaction time and coordination eye-hand is mainly due to the growth of young athletes. Also, performing a 6-week VT using FitLight Trainer is possible improve the reaction time and the motor performance on the field especially in young tennis players under 10 years old
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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