Manipulation of exercise to rest ratio within set duration on physical and technical outcomes during small-sided games in elite youth soccer players

Training practices for elite soccer players should take into account specific technical, tactical and physical components. As a consequence of these demands small-sided games (SSGs) have become a popular conditioning tool that replicate the demands encountered during match play. The aim of this investigation was to examine how the manipulation of exercise to rest ratio, within the same overall duration, affected both physical and technical outcomes during SSGs in elite youth soccer. Twelve elite youth soccer players participated in three variations of eight minute 6v6 SSGs. The three variations included eight minutes continuous, 2 × 4 min and 4 × 2 min. Players perceived the continuous 8 min block as the hardest (4.5 ± 1.5 AU), followed by the 2 × 4 min (3.9 ± 1.4 AU) and the 4 × 2 min (3.3 ± 1.4 AU), although no difference in mean HR or physical measures via GPS analysis between SSGs was evident. From the technical perspective, only goals scored reached significance, with post hoc analysis identifying the number of goals scored were significantly higher during the 4 × 2 min and 2 × 4 min SSGs compared to 8 min continuous block. These results show that subjective ratings of exertion differed between conditions, but only minor technical manipulations were observed by adjusting work to rest ratios, with no significant effect on physical performance.     

Critical Poisson’s ratio between toughness and brittleness

We have a new understanding on a unified fracture criterion based on two kinds of strain energy density. A definite expression which is a function of Poisson’s ratio to describe a crucial parameter in the unified fracture criterion is derived. The critical value of Poisson’s ratio between brittle and ductile materials can be derived as 2/7 which is verified by experimental data. Besides, the effect of Poisson’s ratio on the fracture loci in stress spaces is studied using unified fracture criterion. It is found that the decrease in Poisson’s ratio increases the asymmetry of fracture loci between tensile stress states and compressive stress states in principal stress spaces and between Lode parameters are 1 and ?1 in deviatoric-stress spaces. In addition, stress triaxiality has a great effect on the fracture behaviour with different Poisson’s ratios.     

Distinguishing the Ratio Bias from Unsystematic Error: Situation and Individual‐difference Effects

People often perceive the occurrence of events to be less likely when the likelihood of the event is expressed in ratios consisting of smaller numbers versus larger numbers, an effect known as the ratio bias. This work presents a theoretical framework for the conditions that need to be met for the ratio bias to occur. In doing so, we contrast effects on the ratio bias to those on unsystematic error, which have often been confounded in previous research. We find that the ratio bias is weaker (1) when both sets of numbers are relatively large than when both sets of numbers are relatively small; (2) for scenarios involving lottery tickets than for scenarios involving drawing balls from a bin; and (3) when a physical display depicting the numbers is provided to participants. Each of these factors reduced the ratio bias without reducing unsystematic error. Additionally, we show that unsystematic error is lower among people who (1) reason on the basis of proportions rather than on the basis of the numerator and denominator individually; (2) score higher on the rational scale of the Rational–Experiential Inventory; and (3) are of higher numeracy. We use these results to distinguish causes of error generally from those on the ratio bias specifically and discuss the implications for our understanding of when the ratio bias occurs. Copyright © 2018 John Wiley & Sons, Ltd.     

The sunk cost effect with pigeons: some determinants of decisions about persistence

The sunk cost effect occurs when an individual persists following an initial investment, even when persisting is costly in the long run. The current study used a laboratory model of the sunk cost effect. Two response alternatives were available: Pigeons could persist by responding on a schedule key with mixed ratio requirements, or escape by responding on a second key. In Experiment 1, mean response requirements for persistence and escape were varied across conditions. Pigeons persisted (committing the sunk cost error) when persisting increased the mean response requirement only slightly but not when persisting was sufficiently nonoptimal. Experiment 2 explored more systematically combinations of ratios and probabilities assigned to the schedule key. Persistence varied with the ratio of the mean global response requirements for persistence and escape. In Experiment 3, transitions between ratios were signaled. This reduced nonoptimal persistence, and produced some instances of a reverse sunk cost error--escaping when persistence was optimal. In Experiment 4, it was optimal to escape after the second-smallest ratio ever presented. Pigeons escaped at approximately the optimal juncture, especially in conditions with added signals. Overall, this series of experiments suggests that the sunk cost error may arise in part because persistence is the default behavioral strategy in situations where the contingencies for escape and persistence are insufficiently disparate and/or it is relatively difficult to discriminate when to escape. The study also demonstrates the utility of animal models of complex decision making situations.     

Immediate postsession feeding reduces operant responding in rats

Three experiments investigated the effects of immediate and delayed postsession feeding on progressive-ratio and variable-interval schedule performance in rats. During Experiments 1 and 2, immediate postsession feeding decreased the breakpoint, or largest completed ratio, under progressive-ratio schedules. Experiment 3 was conducted to extend the results of the first two experiments to responding maintained by variable-interval schedules with different session lengths (15 and 60 min). Response rates decreased in all 4 subjects when postsession feeding immediately followed a 15-min session and in 3 of 4 subjects when postsession feeding immediately followed a 60-min session. The implications of this research are twofold: (1) The functional context in which within-session reinforcers are embedded extends outside the experimental chamber, and (2) supplemental postsession feedings should be sufficiently delayed from the end of a session to avoid weakening operant behavior in the experimental sessions.     

Body weight, not facial width-to-height ratio, predicts aggression in pro hockey players

Studies indicate that facial characteristics may predict behavior, but it is unclear if this will hold within highly selective populations. One relevant characteristic is the face’s width-to-height ratio (FWHR), a sexually dimorphic trait that has been shown to predict aggression. That FWHR may predict aggression within highly selective populations was suggested by Carré and McCormick’s (2008) finding that professional hockey players with greater FWHRs accrued more penalties. We attempted to replicate this result using all NHL players. We also explored fighting penalties as another aggression measure and height and weight as additional aggression predictors. We found that body weight predicted substantial variance in aggression but FWHR did not. Thus, in highly selective populations, inferences based on faces may be inaccurate.     

Intrinsic factor controlling the deformation and ductile-to-brittle transition of metallic glasses

The energetic driving force and resistance for shearing and cracking in metallic glasses (MGs) are quantitatively evaluated. A universal thermodynamic criterion is proposed for better understanding the intrinsic correlations between fracture toughness and Poisson’s ratio, the competitions between various deformation modes and the ductile-to-brittle transition in MGs and other materials. A new cooperation parameter δ is also introduced to depict quantitatively the relative propensity of shearing versus cracking. This work could provide insights into the long-standing issues of deformation mechanisms of glassy materials, and be helpful in searching for ductile and tough MGs.     

Simulation of surface effects on the intrinsic dissipation of nanooscillators

The rapid increase of surface area-volume ratio (SVR) with shrinking structure size has a great impact on surface-related intrinsic dissipation, which usually leads to low quality factors for the devices composed of nanoelectromechanical systems. In the present study, the flexural oscillations of nanocantilevers with varying thicknesses and lengths were simulated using the molecular dynamics method, in which the surface effects on the energy dissipation was evaluated when SVR was increased to extremely large values (between 0.4 and 2.0 nm^?1). And, it is also interesting to note that the prediction of the size-dependent Young's modulus by means of resonant frequency of the underdamped oscillation showed good agreement with previous findings.     

Aristotle's Metaphysics: Form,Matter and Identity

ABSTRACT

The example of the Spanish poet’s amnesia, mentioned by Spinoza in the scholium of proposition 39 of part IV of the Ethics in order to elucidate his conception of death, has given rise to many controversies in the scholarly interpretations, which in most cases maintain that the poet dies and that Spinoza himself thought this way. However, the matter is more complex than it at first appears and in this article I take a different path by reconstructing this scholium anew and providing an alternative interpretation. The comparison with selected passages of part V highlights the presence of a bi-conditional between the ratio of motion and rest that a body possesses, and its aptitude to be affected and affect in many more ways. In particular, the latter allows us to acknowledge the continuity of the poet’s individuality, expressed in his mind–body union grounded by the parallelism theory. As a result, the poet case has a crucial explanatory role for Spinoza’s theory of the eternity of the human mind and if one misunderstands the former, the latter is also misconceived.