Biological significance attenuates overshadowing, relative validity, and degraded contingency effects     

Philippe Oberling  Adam S. Bristol  Helena Matute  Ralph R. Miller 《Learning & behavior》2000,28(2):172-186

Miller and Matute (1996) showed that blocking is attenuated when the blocked conditioned stimulus (CS) is “biologically significant” (i.e., when the CS has the potential to elicit vigorous responding of any kind). To the extent that blocking is representative of cue competition, this finding suggests that biological significance protects CSs against cue competition effects in general. In the present experiments, we tested this possibility by examining the influence of biological significance of CSs on other examples of cue competition, namely, overshadowing, the relative stimulus validity effect, and the degraded contingency effect in rats. In Experiment 1, we found that intense auditory stimuli induced transient unconditioned lick suppression, thereby indicating that intense sounds were of high inherent biological significance. In Experiment 2A, we found that cues with high inherent biological significance were protected from overshadowing. In Experiment 2B, this finding was extended to cues with high acquired biological significance, which was obtained through prior pairings with a reinforcer of the valence opposite to that used in the overshadowing treatment. In Experiments 3 and 4, we found that cues with high inherent biological significance attenuated the relative validity effect and the degraded contingency effect, respectively. These results lend support to the view that biological significance (inherent and acquired) protects stimuli from cue competition effects, a finding that is problematic for many contemporary theories of learning.  相似文献   

Modelling performance and skeletal muscle adaptations with exponential growth functions during resistance training     

Antony G. Philippe  Fabio Borrani  Guillaume Py  Robin Candau 《Journal of sports sciences》2019,37(3):254-261

System theory is classically applied to describe and to predict the effects of training load on performance. The classic models are structured by impulse-type transfer functions, nevertheless, most biological adaptations display exponential growth kinetics. The aim of this study was to propose an extension of the model structure taking into account the exponential nature of skeletal muscle adaptations by using a genetic algorithm. Thus, the conventional impulse-type model was applied in 15 resistance trained rodents and compared with exponential growth-type models. Even if we obtained a significant correlation between actual and modelled performances for all the models, our data indicated that an exponential model is associated with more suitable parameters values, especially the time constants that correspond to the positive response to training. Moreover, positive adaptations predicted with an exponential component showed a strong correlation with the main structural adaptations examined in skeletal muscles, i.e. hypertrophy (R² = 0.87, 0.96 and 0.99, for type 1, 2A and 2X cross-sectional area fibers, respectively) and changes in fiber-type composition (R² = 0.81 and 0.79, for type 1 and 2A fibers, respectively). Thus, an exponential model succeeds to describe both performance variations with relevant time constants and physiological adaptations that take place during resistance training.  相似文献   

A genealogical reading of security: power,politics and resistance     

Philippe Fournier 《Culture, Theory & Critique》2018,59(3):262-280

This article assesses French philosopher Frédéric Gros’ contribution to the analysis of security and suggests ways in which it can help us analyse and critique it. By organising security around distinct, historically defined clusters of meaning, Gros gives us a sense of how deeply embedded security is in the constitution of the self, in totalising theological and political projects and in the foundation and maintenance of the modern political order. Indirectly, Gros’ hypotheses can provide us with the critical resources to respond to and resist the various embodiments of security. Whilst resistance to contemporary modes of risk-management can take the form of aesthetic disruptions and agonistic self-definition, resistance to more traditional forms of security requires the mobilisation of bodies and juridical resources. Building on but also departing from Gros’ genealogy, the article contends that these forms of resistance have to be combined and simultaneous if we are to disrupt security’s multiple power effects.  相似文献   

Initial foot contact and related kinematics affect impact loading rate in running     

Bastiaan Breine  Philippe Malcolm  Ine Van Caekenberghe  Pieter Fiers  Edward C. Frederick  Dirk De Clercq 《Journal of sports sciences》2017,35(15):1556-1564

This study assessed kinematic differences between different foot strike patterns and their relationship with peak vertical instantaneous loading rate (VILR) of the ground reaction force (GRF). Fifty-two runners ran at 3.2 m · s^?1 while we recorded GRF and lower limb kinematics and determined foot strike pattern: Typical or Atypical rearfoot strike (RFS), midfoot strike (MFS) of forefoot strike (FFS). Typical RFS had longer contact times and a lower leg stiffness than Atypical RFS and MFS. Typical RFS showed a dorsiflexed ankle (7.2 ± 3.5°) and positive foot angle (20.4 ± 4.8°) at initial contact while MFS showed a plantar flexed ankle (?10.4 ± 6.3°) and more horizontal foot (1.6 ± 3.1°). Atypical RFS showed a plantar flexed ankle (?3.1 ± 4.4°) and a small foot angle (7.0 ± 5.1°) at initial contact and had the highest VILR. For the RFS (Typical and Atypical RFS), foot angle at initial contact showed the highest correlation with VILR (r = ?0.68). The observed higher VILR in Atypical RFS could be related to both ankle and foot kinematics and global running style that indicate a limited use of known kinematic impact absorbing “strategies” such as initial ankle dorsiflexion in MFS or initial ankle plantar flexion in Typical RFS.  相似文献   

Active tuning of stroke-induced vibrations by tennis players     

Delphine Chadefaux  Guillaume Rao  Philippe Androuet  Eric Berton  Laurent Vigouroux 《Journal of sports sciences》2017,35(16):1643-1651

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Antidepressant effects associated with different exercise conditions in participants with depression: a pilot study     

Legrand F  Heuze JP 《运动与训练心理学杂志》2007,29(3):348-364

In this article, we examined the antidepressant influence of an 8-week-long aerobic exercise intervention in which two training parameters were manipulated: exercise frequency and group environment. Twenty-three individuals with elevated symptoms of depression were recruited in a sport and fitness facility and agreed to participate in this 8-week study. They were randomly assigned to three groups: (a) low-frequency exercise (control) (n = 7), (b) high-frequency exercise (n = 8), and (c) high-frequency exercise + group-based intervention (n = 8). Participants completed the Beck Depression Inventory (BDI-II) at study entry, and at 4 and 8 weeks subsequently. The results showed that those in the high-frequency aerobic exercise experimental groups reported lower depression scores than those in the low-frequency (control) group at 4 weeks (13.2 +/- 7.3 and 11.7 +/- 3.1 vs. 22.4 +/- 7.5) and 8 weeks (10.9 +/- 8.1 and 9.6 +/- 2.5 vs. 20.7 +/- 6.3). However, alleviation in depressive symptoms was not found to be greater in those participants who received a group-based intervention.  相似文献   

Three Gorges Dam: friend or foe of riverine greenhouse gases?     

Jinren Ni  Haizhen Wang  Tao Ma  Rong Huang  Philippe Ciais  Zhe Li  Yao Yue  Jinfeng Chen  Bin Li  Yuchun Wang  Maosheng Zheng  Ting Wang  Alistair G L Borthwick 《国家科学评论(英文版)》2022,9(6)

Dams are often regarded as greenhouse gas (GHG) emitters. However, our study indicated that the world''s largest dam, the Three Gorges Dam (TGD), has caused significant drops in annual average emissions of CO₂, CH₄ and N₂O over 4300 km along the Yangtze River, accompanied by remarkable reductions in the annual export of CO₂ (79%), CH₄ (50%) and N₂O (9%) to the sea. Since the commencement of its operation in 2003, the TGD has altered the carbonate equilibrium in the reservoir area, enhanced methanogenesis in the upstream, and restrained methanogenesis and denitrification via modifying anoxic habitats through long-distance scouring in the downstream. These findings suggest that ‘large-dam effects’ are far beyond our previous understanding spatiotemporally, which highlights the fundamental importance of whole-system budgeting of GHGs under the profound impacts of huge dams.  相似文献   

Initial psychometric testing of the coach-adapted version of the empowering and disempowering motivational climate questionnaire: A Bayesian approach     

Bård Erlend Solstad  Andreas Stenling  Yngvar Ommundsen  Bente Wold  Jean-Philippe Heuzé  Philippe Sarrazin 《Journal of sports sciences》2020,38(6):626-643

ABSTRACT

The present study examined the psychometric properties of the coach-adapted version of the Empowering and Disempowering Motivational Climate Questionnaire (EDMCQ) using Bayesian structural equation modelling (BSEM). The sample included 780 (M_age = 36.4; SD = 10.8; males n = 698; females n = 54; 28 participants did not report sex) youth sport coaches representing five European countries (i.e., England, France, Greece, Norway, and Spain). The results did not support a 34-item five-factor, hierarchical, a two-factor BSEM, or a bifactor BSEM model across the participating countries. However, the results supported a reduced 19-item first-order, two-factor BSEM model that largely showed approximate metric invariance, but not approximate scalar invariance across the five countries. The pool of items constituting empowering and disempowering motivational climates should be refined to further enhance the empirical operationalisation of the coach-adapted version of the EDMCQ. Advancing the quality of translation-back-translation procedures across cultures and conducting multi-national pilot testing seems warranted as well. These recommendations may help to identify the distinctive aspects of each underlying sub-dimension of the EDMCQ, where coaches are the respondents, and pave the way for further examination of the proposed hierarchical multidimensional factor structure and the cross-cultural equivalence of the EDMCQ for this population.  相似文献   

From Mitropa Cup to UEFA Cup: the role of UEFA in the establishment of a European scale in football, 1927–1972     

Philippe Vonnard 《Soccer & Society》2019,20(7-8):1025-1040

ABSTRACT

Since the 1920s, many European exchanges began to exist in the domain of football. However, it was during the 1950s that a European scale was established primarily due to the creation of UEFA (Union of European Football Associations) in 1954, which quickly organized the first European tournament in the game’s history– The European Champions Clubs’ Cup. The present essay argues that Europeanization of the game has to be understood in a long-term perspective. The papers examines the creation and development of three competitions as key defining events, which represented different stages of the Europeanization of the game: Mitropa Cup (created in 1927), European Champion Clubs’ Cup (created in 1955) and UEFA Cup (created in 1971). Thus, afocus on these cases can help us better understand the background of the Europeanization of the game which happened during the 1990s.  相似文献   

Assessment of the risk and biomechanical consequences of lateral epicondylalgia by estimating wrist and finger muscle capacities in tennis players     

Laurent Vigouroux  Benjamin Goislard de Monsabert  Chris Hayot  Philippe Androuet  Éric Berton 《Sports biomechanics / International Society of Biomechanics in Sports》2017,16(4):434-451

Previous studies suggested that a pronounced weakness of the extensor muscles relative to the flexor muscles could increase the risk of occurrence of lateral epicondylalgia. This study investigates this hypothesis by estimating the ratio of extensor to flexor muscle capacities among healthy non-players (n = 10), healthy tennis players (n = 20), symptomatic players (n = 6), and players who have recovered from lateral epicondylalgia (n = 6). Maximum net joint moments in flexion or extension were measured during seven tasks involving the voluntary contraction of wrist and fingers. Using these data, the muscle capacities of the main muscle groups of the hand (wrist flexors, wrist extensors, finger flexors, finger extensors, and intrinsic muscles) were estimated using a musculoskeletal model. These capacities were then used to compute the extensor/flexor capacity ratios about the wrist and the finger joints. Compared to healthy non-players, healthy players presented higher extensor muscle capacities and greater capacity ratios showing that playing tennis generates specific adaptations of muscle capacities. Interestingly, symptomatic players, similar to those of non-players, showed more imbalanced ratios than healthy players. These results confirm that the ratio of extensor/flexor muscle capacities seems to be associated with lateral epicondylalgia and can be further used to understand its incidence and consequences.  相似文献