775 research outputs found

    Executive Function and Mood: The Moderating Role of Athletic Expertise

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    Executive function (EF) is known to be influenced by mood, but whether this relationship holds for populations of athletes and whether athletic expertise moderates it is uncertain. Thus, in the current study, we examined relationships between positive and negative affect (i.e., mood), the lower-order cortical aspects of executive function (i.e., inhibition, shifting and updating), and athletic expertise. A sample of 256 participants (55.08% male; Mage = 20.69) completed a self-report mood measure and computerized tests of EF. Individuals with more athletic expertise reported higher positive affect and better EF scores, whereas those with less athletic expertise reported higher negative affect. Structural equation modelling indicated that positive affect was related to better inhibition, shifting, and updating performance but was not related to performance errors. Similarly, negative affect was related to better EF, except for the inhibition latency score. Athletic expertise moderated all significant associations between mood and EF and higher expertise facilitated higher EF performance. Together, athletic expertise is an important individual differences factor in understanding the influence of mood on EF performance

    The empirical accuracy of uncertain inference models

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    Uncertainty is a pervasive feature of the domains in which expert systems are designed to function. Research design to test uncertain inference methods for accuracy and robustness, in accordance with standard engineering practice is reviewed. Several studies were conducted to assess how well various methods perform on problems constructed so that correct answers are known, and to find out what underlying features of a problem cause strong or weak performance. For each method studied, situations were identified in which performance deteriorates dramatically. Over a broad range of problems, some well known methods do only about as well as a simple linear regression model, and often much worse than a simple independence probability model. The results indicate that some commercially available expert system shells should be used with caution, because the uncertain inference models that they implement can yield rather inaccurate results

    Impact of ethanol on continuous inline diafiltration of liposomal drug products

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    Liposomal drug products are playing an increasing role in the field of drug delivery. With this increased demand comes the need to increase the capabilities and capacity of manufacturing options. Continuous manufacturing techniques present a significant opportunity to address these needs for liposomal manufacturing processes. Liposomal formulations have unique considerations that impact translation from batch to continuous process designs. This article examines aspects of converting to a continuous design that were previously viewed as inconsequential in a batch process. The batch process involves the removal of ethanol (EtOH) through tangential flow filtration (TFF). EtOH was found to reduce the permeability of the hollow fibers used for TFF. This effect was determined to have minimal impact on the overall batch process design but considerable influence on the design of continuous TFF such as inline diafiltration (ILDF). Using a pilot scale setup, EtOH was found to decrease permeability in an inverse manner to EtOH concentration. Further assessment found that dilution of the EtOH levels prior to diafiltration can significantly reduce the amount of ILDF stages needed and that a continuous design requires less buffer to the commensurate batch design

    Psychometrics of the Emotional Intelligence Scale in Elite, Amateur and Non-athletes

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    The purpose of this study was to assess the psychometrics properties of the Emotional Intelligence Scale (Schutte et al., 1998) and assess the measurement invariance across elite (n = 367), amateur (n = 629) and non-athletes (n = 550). In total, 1,546 participants from various sports completed the emotional intelligence scale. Several competing models were compared through exploratory structural equation modelling. The analyses were performed on the whole sample before subsequent invariance testing between athletic groups. The internal consistency of the scale was tested through Omega for the total scale and relevant subscales, which indicated largely unacceptable levels of stability. Results failed to support the purported unidimensional or four factor models proposed in the literature. However, a six-factor model provided the best fit to the data. Nonetheless, there was no evidence for weak or strong invariance suggesting that the scale may not be appropriate for use within athletic samples

    Attention, working-memory control, working-memory capacity, and sport performance: The moderating role of athletic expertise

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    The aim of this research was to detangle the association between attention, working-memory (focusing on both control and capacity functions), and sport performance across athletic expertise. Specifically, the mediating effect of working-memory-control and working-memory-capacity on the attention and performance relationship will be investigated, and whether this effect differs across athlete expertise. A sample of 359 athletes (Mage = 18.91 ± SD = 1.01; 54.87% male) with a range of athletic expertise (novice n = 99, amateur n = 92, elite n = 87, and super-elite n = 81) completed a battery of neurocognitive tasks assessing attention, working-memory-control, working-memory-capacity, and a cognitively engaging motor task (e.g., basketball free-throw task). Athletes with more expertise performed better on tasks of attention, working-memory-control and working-memory-capacity. Results of structural equation modelling indicated a positive association between the cognitive measures and sport performance. Specifically, working-memory-control and working-memory-capacity mediated the attention and sport performance relationship. Additionally, invariance testing indicated larger effects for those with more athletic expertise. These findings provide a better understanding of how attention and the control and capacity functions of working-memory interact to predict performance. Theoretical and practical implications of these results are discussed

    Measuring Leadership in Sport

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    The following chapter provides an overview of the more established methods of measuring leadership in sport. The Mediational Model of Leadership and the Multidimensional Model of leadership are outlined with their respective measures, the Coaching Behaviour Assessment System and the Leadership Scale for Sports respectively (Smoll & Smith, 1989; Chelladurai, 1993). The chapter also highlights specific issues regarding measurement of the scales i.e. psychometrics. An explanation of the methods used to assess scales psychometrics is also provided throughout therefore enhancing the usability of the chapter for students and practitioners interested in measuring leadership. The reliability and validity of the instruments are discussed with reference to the scales development and later empirical research assessing the utility of the measures. Furthermore, Recommendations and summaries of current directions along with alternative measures are proposed

    The Remarkably Featureless High Resolution X-ray Spectrum of Mrk 478

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    An observation of Mrk 478 using the Chandra Low Energy Transmission Grating Spectrometer is presented. The source exhibited 30-40% flux variations on timescales of order 10000 s together with a slow decline in the spectral softness over the full 80 ks observation. The 0.15--3.0 keV spectrum is well fitted by a single power law with photon index of Gamma = 2.91 +/- 0.03. Combined with high energy data from BeppoSAX, the spectrum from 0.15 to 10 keV is well fit as the sum of two power laws with Gamma = 3.03 +/- 0.04, which dominates below 2 keV and 1.4 +/- 0.2, which dominates above 2 keV (quoting 90% confidence uncertainties). No significant emission or absorption features are detected in the high resolution spectrum, supporting our previous findings using the Extreme Ultraviolet Explorer but contradicting the claims of emission lines by Hwang & Bowyer (1997). There is no evidence of a warm absorber, as found in the high resolution spectra of many Sy 1 galaxies including others classified as narrow line Sy 1 galaxies such as Mrk 478. We suggest that the X-ray continuum may result from Comptonization of disk thermal emission in a hot corona through a range of optical depths.Comment: 21 pages, 7 figures; accepted for publication in the Astronomical Journa
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