543 research outputs found

    A Meta-Analytic Review of Achievement Goal Orientation Correlates in Competitive Sport: A Follow-Up to Lochbaum et al. (2016)

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    Recent quantitative research in competitive sport with the Task and Ego Orientations in Sport Questionnaire (TEOSQ) and Perceptions of Success Questionnaire (POSQ) pointed to a potential critical issue that the two questionnaires did not agree across a number tested hypotheses (Lochbaum, Kazak Çetinkalp, Graham, Wright, & Zazo, 2016). Thus, the present quantitative review examined whether correlates of the two achievement goal orientations were moderated by the two measures. To achieve this purpose, 772 unique correlates (489 TEOSQ, 283 POSQ; 402 task orientation, 370 ego orientation) from 93 studies spanning 1989-2016 from 32 countries with 26,387 participants were placed into 15 different categories and meta-analyzed. The task goal orientation was significantly and small to moderate in meaningfulness related to adaptive success factors (rw=.29), maladaptive success factors (rw=-.12), desirable behaviors (rw=.28), positive emotions (rw=.35), amotivation (rw=-.13), extrinsic motivation (rw=.20), external regulations (rw=.12), internal regulations (rw=.34), intrinsic motivation (rw=.47), the mastery/task climate (rw=.38), perceived competence (rw=.26), and trait selfesteem (rw=.35). The ego goal orientation was significantly and small in meaningfulness related to adaptive success factors (rw=.10), maladaptive success factors (rw=.12), negative emotions (rw=.11), undesirable behaviors (rw=.23), amotivation (rw=.16), extrinsic motivation (rw=.28), external regulation (rw=.21), intrinsic motivation (rw=.14), performance/ego climate (rw=.28), and perceived competence (rw=.17). The questionnaire measure was a significant moderator for the task goal orientation relationship with desirable behaviors (POSQ rw=.24; TEOSQ rw=.37), internal regulations (POSQ rw=.26; TEOSQ rw=.39), and trait self-esteem (POSQ rw=.45; TEOSQ rw=.32) and for the ego goal orientation relationship with performance/ego climate (POSQ rw=.34; TEOSQ rw=.24). Overall, the extent of the questionnaire type being a concern when examining correlates was fortunately minimal. Yet, differences in the two dominant measures exit. Recommendations for future research examining both the TEOSQ and POSQ were proposed

    Vertical-external-cavity surface-emitting lasers and quantum dot lasers

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    The use of cavity to manipulate photon emission of quantum dots (QDs) has been opening unprecedented opportunities for realizing quantum functional nanophotonic devices and also quantum information devices. In particular, in the field of semiconductor lasers, QDs were introduced as a superior alternative to quantum wells to suppress the temperature dependence of the threshold current in vertical-external-cavity surface-emitting lasers (VECSELs). In this work, a review of properties and development of semiconductor VECSEL devices and QD laser devices is given. Based on the features of VECSEL devices, the main emphasis is put on the recent development of technological approach on semiconductor QD VECSELs. Then, from the viewpoint of both single QD nanolaser and cavity quantum electrodynamics (QED), a single-QD-cavity system resulting from the strong coupling of QD cavity is presented. A difference of this review from the other existing works on semiconductor VECSEL devices is that we will cover both the fundamental aspects and technological approaches of QD VECSEL devices. And lastly, the presented review here has provided a deep insight into useful guideline for the development of QD VECSEL technology and future quantum functional nanophotonic devices and monolithic photonic integrated circuits (MPhICs).Comment: 21 pages, 4 figures. arXiv admin note: text overlap with arXiv:0904.369

    Diminished salivary epidermal growth factor secretion : a link between Sjogren's syndrome and autoimmune gastritis?

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    Objectives: Healthy human labial salivary glands produce epidermal growth factor (EGF). In Sjogren's syndrome (SS), EGF staining is diminished. SS is also associated with chronic autoimmune corpus gastritis. We therefore hypothesized that EGF secretion would be diminished in SS and that this could affect gastric target cells.Methods: Salivary EGF secretion in SS was compared to that in healthy controls using an enzyme-linked immunosorbent assay (ELISA). EGF receptor (EGFR) immunoreactive cells in the gastric corpus of healthy human subjects were analysed using immunostaining.Results: Salivary secretion of EGF was diminished in SS patients (232.4, range 52.6-618.4, vs. 756.6, range 105.3-1631.6 pg/min, p=0.002). Proton-pump positive parietal cells were mostly EGFR immunoreactive whereas very few pepsinogen I (PGI)-positive cells were EGFR positive.Conclusions: As EGF is relatively acid resistant, salivary gland-derived EGF might participate in an exo/endocrine mode of parietal cell maintenance in the gastric corpus. Deficiency of salivary gland-derived EGF in SS patients may cause impairment of gastric parietal cells resulting in exposure of immunogenic cryptic antigens and loss of immunological self-tolerance.Peer reviewe

    Quiet Eye Duration and Gun Motion in Elite Shotgun Shooting

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    INTRODUCTION: No literature exists to document skill-related differences in shotgun shooting and whether these may be a function of eye movements and control of gun motion. We therefore conducted an exploratory investigation of the visual search behaviors and gun barrel kinematics used by elite and subelite shooters across the three shotgun shooting subdisciplines. METHODS: Point of gaze and gun barrel kinematics were recorded in groups of elite (n = 24) and subelite (n = 24) shooters participating in skeet, trap, and double trap events. Point of gaze was calculated in relation to the scene, while motion of the gun was captured by two stationary external cameras. Quiet eye (final fixation or tracking gaze that is located on a specific location/object in the visual display for a minimum of 100 ms) duration and onset were analyzed as well as gun motion profiles in the horizontal and vertical planes. RESULTS: In skeet, trap, and double trap disciplines, elite shooters demonstrated both an earlier onset and a longer relative duration of quiet eye than their subelite counterparts did. Also, in all three disciplines, quiet eye duration was longer and onset earlier during successful compared with unsuccessful trials for elite and subelite shooters. Kinematic analyses indicated that a slower movement of the gun barrel was used by elite compared with subelite shooters. CONCLUSIONS: Overall, stable gun motion and a longer quiet eye duration seem critical to a successful performance in all three shotgun disciplines
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