44 research outputs found
Preciseness of Subtyping on Intersection and Union Types
Abstract. The notion of subtyping has gained an important role both in theoretical and applicative domains: in lambda and concurrent calculi as well as in programming languages. The soundness and the complete-ness, together referred to as the preciseness of subtyping, can be consid-ered from two different points of view: denotational and operational. The former preciseness is based on the denotation of a type which is a math-ematical object that describes the meaning of the type in accordance with the denotations of other expressions from the language. The latter preciseness has been recently developed with respect to type safety, i.e. the safe replacement of a term of a smaller type when a term of a bigger type is expected. We propose a technique for formalising and proving operational pre-ciseness of the subtyping relation in the setting of a concurrent lambda calculus with intersection and union types. The key feature is the link between typings and the operational semantics. We then prove sound-ness and completeness getting that the subtyping relation of this calculus enjoys both denotational and operational preciseness.
Preliminary results on organization on the court, physical and technical performance of Brazilian professional futsal players: comparison between friendly pre-season and official match
Deshidratación y reposición hídrica en jugadores de fútbol sala: Efectos de un programa de intervención sobre la pérdida de líquidos durante la competición
This work has a double purpose, on one hand, to know the dehydration of a futsal team during the competition, and on the other, to assess the effects of an intervention programme, which last fifteen days, in order to make players aware of the importance of hydration in sport performance and avoid processes of dehydration during the competition and training. Three official matches were evaluated, the first before the intervention programme and the second and the third in the following two weeks. The mean of the dehydration in the three marches were 1.7±1.0%, 0.8±0.8% and 0.9±0.7%, respectively. Comparing the dehydration values of the first match (before the intervention) with the following two matches (during and after the programme) we find significant differences during the half time (and the end of the match. Results give us the idea that the futsal players, despite having many opportunities to drink enough fluid, don¿t drink all they need and reach a high dehydration that could affect players¿ performance. The use of strategies to improve fluid replacement produces a significant decrease of the dehydration during the competition.El propósito de este trabajo ha sido doble, por un lado, conocer las pérdidas de líquidos (deshidratación) de un equipo profesional de fútbol sala durante la competición, y por otro, valorar los efectos de un programa de intervención de 15 días para concienciar acerca de la importancia de la hidratación en el rendimiento deportivo y evitar procesos de deshidratación durante la competición y los entrenamientos. Se valuaron tres partidos oficiales, uno previo a la intervención y los jugados en las dos semanas siguientes. La deshidratación media en los tres encuentros fue de 1.7±1.0%, 0.8±0.8% y 0.9±0.7%, respectivamente. Al comparar los valores de deshidratación encontrados en el primer partido (previo a la intervención) con los 2 partidos siguientes (durante y después del programa), hallamos diferencias significativas, tanto en el descanso como al finalizar el encuentro. Los resultados obtenidos sugieren que los jugadores de fútbol sala, a pesar de disponer de un elevado número de ocasiones para ingerir volúmenes adecuados de líquido, no son capaces de beber suficiente y alcanzan estados de deshidratación sustanciales y muy heterogéneos que podrían afectar el rendimiento de los deportistas. El empleo de estrategias para favorecer la reposición de líquidos produce una disminución significativa de la deshidratación voluntaria durante la competición
Muscle damage, inflammatory, immune and performance responses to three football games in 1 week in competitive male players
Purpose: We examined effects of a three-game, 1-week microcycle (G1, G2, G3) on recovery of performance and inflammatory responses in professional male footballers. Methods: Players were randomized into an experimental (EXP; N = 20) and a control group (CON; N = 20). Blood was drawn and repeated sprint ability (RSA), muscle soreness and knee range of motion (KJRM) were determined pre- and post-games and during recovery. Results: High-intensity running during G2 was 7–14 % less compared to G1 and G3. RSA declined in EXP by 2–9 % 3 days post-game with G2 causing the greatest performance impairment. In EXP, game play increased muscle soreness (~sevenfold) compared to CON with G2 inducing the greatest rise, while KJRM was attenuated post-game in EXP compared to CON (5–7 %) and recovered slower post G2 and G3 than G1. CK, CRP, sVCAM-1, sP-Selectin and cortisol peaked 48 h post-games with G2 eliciting the greatest increase. Leukocyte count, testosterone, IL-1β and IL6 responses, although altered 24 h post each game, were comparable among games. Plasma TBARS and protein carbonyls rose by ~50 % post-games with G2 eliciting the greatest increase 48 h of recovery. Reduced to oxidized glutathione ratio declined for 24 h post all games with G2 displaying the slowest recovery. Total antioxidant capacity and glutathione peroxidase activity increased (9–56 %) for 48 h in response to game play. Conclusion: In summary, post-game performance recovery and inflammatory adaptations in response to a three-game weekly microcycle displayed a different response pattern, with strong indications of a largest physiological stress and fatigue after the middle game that was preceded by only a 3-day recovery. © 2015, Springer-Verlag Berlin Heidelberg
Bisimulation Proof Methods for Mobile Ambients
We study the behavioural theory of Cardelli and Gordon's Mobile Ambients. We give an LTS based operational semantics, and a labelled bisimulation based equivalence that coincides with reduction barbed congruence. We also provide up-to proof techniques and prove a set of algebraic laws, including the perfect firewall equation