An integrative analysis of intrinsic and extrinsic motivation in sport

Author: Vallerand, R.J.; Losier, G.F. Description: The purpose of this paper is to propose a motivational sequence that integrates much of the intrinsic and extrinsic motivation literature in sport. The proposed motivational sequence: “Social Factors –>Psychological Mediators –>Types of Motivation –>Consequences” is in line with self-determination theory (Deci & Ryan. 1985. 1991) and the Hierarchical model of intrinsic and extrinsic motivation (Vallerand, 1997). Using the sequence, it is first shown that the motivational impact of social factors inherent in sport, such as competition/cooperation, success/failure, and coaches’ behaviors toward athletes, takes…

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The joint evolution of mating system and pollen performance: Predictions regarding male gametophytic evolution in selfers vs. outcrossers

Author: Mazer, S.J.; Hove, A.A.; Miller, B.S.; Barbet-Massin, M. Description: Studies of sexual selection in plants historically have focused on pollinator attraction, pollen transfer, gametophytic competition, and post-fertilization discrimination by maternal plants. Pollen performance (the speeds of germination and pollen tube growth) in particular is thought to be strongly subject to intrasexual selection, but the effect of mating system on this process has not been rigorously evaluated. Here we propose four predictions derived from the logic that pollen performance should evolve with mating system as an adaptive response to: (1)…

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The effects of violent video games on aggression: A meta-analysis

Author: Sherry, J. Description: Violent content video games such as Mortal Kombat and Doom have become very popular among children and adolescents, causing great concern for parents, teachers, and policy makers. This study cumulates findings across existing empirical research on the effects of violent video games to estimate overall effect size and discern important trends and moderating variables. Results suggest there is a smaller effect of violent video games on aggression than has been found with television violence on aggression. This effect is positively associated with type of game violence…

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Inhibitory effect of Cinnamomum cassia oil on non-O157 Shiga toxin-producing Escherichia coli

Author: Sheng, L.; Zhu, M.-J. Description: Shiga toxin-producing Escherichia coli (STEC) have caused numerous foodborne outbreaks. Compared with the most well-known STEC E. coli O157:H7, importance of non-O157 STEC has been underestimated and they have gained far less attention till increasing outbreaks recently. Using natural plant materials as antimicrobial agents is a heated area. Therefore in this study, Cinnamomum cassia, a widely used spice in cuisine, was tested for its antibacterial efficacy on CDC “top six” non-O157 STECs including O26, O45, O103, O111, O121, O145. Gas chromatography-mass spectrometry analysis showed…

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Priming Mammies, Jezebels, and Other Controlling Images: An Examination of the Influence of Mediated Stereotypes on Perceptions of an African American Woman

Author: Brown Givens, S.M.; Monahan, J.L. Description: This study examines how mediated portrayals of African American women influence judgments of African American women in social situations. Participants (N = 182) observed a mammy, jezebel, or nonstereotypic image on video. Participants then observed a mock employment interview involving either an African American or White woman. Participants completed measures of implicit and explicit racial prejudice. As hypothesized, participants associated the African American interviewee more quickly with negative terms (e.g., aggressive) than with positive terms (e.g., sincere). Also as hypothesized, when evaluating the…

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Synapse-specific control of synaptic efficacy at the terminals of a single neuron

Author: Davis, G.W.; Goodman, C.S. Description: The regulation of synaptic efficacy is essential for the proper functioning of neural circuits. If synaptic gain is set too high or too low, cells are either activated inappropriately or remain silent. There is extra complexity because synapses are not static, but form, retract, expand, strengthen, and weaken throughout life. Homeostatic regulatory mechanisms that control synaptic efficacy presumably exist to ensure that neurons remain functional within a meaningful physiological range. One of the best defined systems for analysis of the mechanisms that regulate synaptic…

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Photo-electrochemical hydrogen generation from water using solar energy. Materials-related aspects

Author: Bak, T.; Nowotny, J.; Rekas, M.; Sorrell, C.C. Description: The present work considers hydrogen generation from water using solar energy. The work is focused on the materials-related issues in the development of high-efficiency photo-electrochemical cells (PECs). The property requirements for photo-electrodes, in terms of semiconducting and electrochemical properties and their impact on the performance of PECs, are outlined. Different types of PECs are overviewed and the impact of the PEC structure and materials selection on the conversion efficiency of solar energy are considered. Trends in research in the development…

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Enhancement of the photoelectrochemical performance of CuWO4 films for water splitting by hydrogen treatment

Author: Tang, Y.; Rong, N.; Liu, F.; Chu, M.; Dong, H.; Zhang, Y.; Xiao, P. Description: CuWO4 films with feature particle sizes of 100–200 nm and thickness up to 700–900 nm on fluorine-doped tin oxide (FTO) substrates were prepared by hydrothermal synthesis. The prepared CuWO4 films were treated in hydrogen atmosphere at constant temperature 300 °C for different annealing time and used for photoelectrochemical (PEC) water oxidation. Compared with pristine CuWO4 film, the optimized hydrogen-treated CuWO4 film presented three times enhanced photocurrent density of 0.75 mA/cm2 at 1.2 V vs….

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Listen to the noise: noise is beneficial for cognitive performance in ADHD

Author: Soderlund, G.; Sikstrom, S.; Smart, A. Description: BACKGROUND: Noise is typically conceived of as being detrimental to cognitive performance. However, given the mechanism of stochastic resonance, a certain amount of noise can benefit performance. We investigate cognitive performance in noisy environments in relation to a neurocomputational model of attention deficit hyperactivity disorder (ADHD) and dopamine. The Moderate Brain Arousal model (MBA; Sikstrom & Soderlund, 2007) suggests that dopamine levels modulate how much noise is required for optimal cognitive performance. We experimentally examine how ADHD and control children respond to…

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Human information processing during physical exercise

Author: Paas, F.G.; Adam, J.J. Description: This study was designed to investigate how conditions of physical exercise affect human information processing. Sixteen subjects performed two information processing tasks (perception and decision) during two exercise conditions (endurance vs interval protocols) and during two control conditions (rest vs minimal load protocols). The control conditions required subjects either to perform the information processing tasks under resting conditions or while pedalling a bicycle ergometer at a minimal workload. Workload during the exercise protocols consisted of a fixed percentage of the subject’s maximal workload. Each…

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