2,937 research outputs found

    Mentale Toughness im Sport: Ein Review

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    Zusammenfassung: In dem vorliegenden Beitrag wird die bestehende Literatur zum Thema mentale Toughness im Sport zusammengefasst. Die Literaturübersicht zeigt, dass es zunächst mittels qualitativer Studien gelang, konzeptuelle Klarheit zu schaffen und Orientierungshilfen für die Operationalisierung des Konstrukts bereitzustellen. In der Folge wurden über das Psychological Performance Inventory (PPI) hinaus weitere quantitative Messinstrumente entwickelt, deren Validität und Reliabilität ansatzweise dokumentiert sind. Mit Hilfe dieser Instrumente konnte nachgewiesen werden, dass zwischen mentaler Toughness und sportlichem Erfolg ein Zusammenhang besteht. Mit Blick auf die möglichen Wirkungsmechanismen deutet sich an, dass mental starke Athleten über günstigere Bewältigungsstrategien verfügen. Obschon Konsens besteht, dass mentale Toughness einem überdauernden Merkmal entspricht, konnte belegt werden, dass sich auch mit Hilfe eines Mentaltrainings positive Effekte erzielen lassen. Zum aktuellen Zeitpunkt besteht ein großer Bedarf an quantitativen, längsschnittlichen und experimentell angelegten Studien. Ebenso ist der biopsychologische Ansatz ein vielversprechender Zugang für weitere Studie

    Acculturation and physical activity among immigrants: a systematic review

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    Aim: The acculturation process presents numerous challenges that could benefit or adversely affect immigrants' health practices. The goal of this review was to present a systematic summary of studies examining the relationship between acculturation and physical activity among immigrants and ethnic minority populations. Subjects and methods: Systematic review based on 44 original studies found in electronic databases (Psychinfo/Psyndex, Eric, Pubmed/Medline, Web of Science, SportDiscus). Studies were eligible if they were written in English, German or French, incorporated a measure of acculturation and physical activity, exercise, or sport as independent and dependent variables, and provided statistical information to judge the level of significance. The 44 studies found included 760,242 participants. A narrative synthesis was performed. Causality of effects was examined based on seven criteria: consistency, strength of associations, specificity of effects, temporality, gradient, plausibility and experimental evidence. Results: Acculturation was associated with higher leisure time physical activity in 57% of all studies (even after controlling for potential confounds), independent of participants' gender, age and ethnic background. The main limitations of this review are that findings were not weighted for sample size and that publication biases might have contributed to an overestimation of the relationships. Conclusion: Prevention programs aimed at stimulating participation in physical activity among immigrants should give priority to individuals with low acculturation levels and it should consider culturally specific beliefs and constraints. Additionally, prevention programs could make an effort to promote acculturation among immigrants. Future studies should use longitudinal designs which include objective assessments of physical activity and which use multidimensional and bidirectional definitions of acculturatio

    Fluid leakage past tracheal tube cuffs: evaluation of the new Microcuff endotracheal tube

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    Objective: This study compared the recently introduced Microcuff endotracheal tube HVLP ICU featuring an ultrathin (7-µm) polyurethane cuff membrane with endotracheal tubes from different manufacturers regarding fluid leakage past the tube cuff. Design: In vitro setup. Measurements and results: The following endotracheal tubes (ID 7.5mm) were compared: Mallinckrodt HiLo, Microcuff HVLP ICU, Portex Profile Soft Seal, Rüsch Super Safety Clear, and Sheridan CF. A vertical PVC trachea model (ID 20mm) was intubated, and cuffs were inflated to 10, 15, 20, 25, 30, and 60cmH2O. Colored water (5ml) was added to the top of the cuff. The amount of leaked fluid past the tube cuff within 5, 10, and 60min was recorded. Experiments were performed four times using two examples of each tube brand. Fluid leakage past tube cuffs occurred in all conventional endotracheal tubes at cuff pressures from 10 to 60cmH2O. In the Microcuff tube cuff pressure fluid leakage was observed within 10min only at 10cmH2O. Results with the Microcuff tube were significantly better than all other tube brands at cuff pressures of 10-30cmH2O. Conclusions: Within the acceptable upper limit for tracheal cuff pressure (25-30cmH2O) the Microcuff endotracheal tube was the only one of the tested tubes to prevent fluid leakage in our in vitro setup. In vivo studies are required to confirm these finding

    Effects of two types of exercise training on psychological well-being, sleep, quality of life and physical fitness in patients with high-grade glioma (WHO III and IV): study protocol for a randomized controlled trial

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    There is existing evidence on whether and to what degree regular exercise training improves the quality of life (QoL) among cancer survivors. However, in regards to patients with high-grade glioma (HGG; WHO grade III and IV), no conclusive study has been performed so far. The present trial aims to fill this gap by examining whether psychological well-being, sleep, QoL and physical fitness might be improved with two different types of exercise, as compared to an active control condition. Active control condition represent individuals participating at regular meetings to talk about their current life situation, though, the meetings were not intended as that of the psychotherapy group. Regular meetings are of the same frequency, duration, and intensity as the exercise interventions.; A total of 45 patients with HGG after undergoing neurosurgery and adjuvant radiotherapy, chemotherapy, or chemoradiotherapy will be consecutively and randomly assigned to (a) an endurance training, (b) a resistance training or (c) to an active control condition. The intervention will last for 6 consecutive weeks, consisting of 2 weekly sessions (30-45 min per session). Measurements would take place at three time points, namely at the beginning of the study (baseline), 3 weeks after the beginning of the study, and 6 weeks after the beginning of the study. The last measurement also represents the end of the study. Aerobic exercise performance will be assessed objectively with a 6-min walking test, and a handgrip test will be used to assess the upper body strength. Further, participants will complete a battery of questionnaires covering sociodemographic information, QoL, sleep quality and sleep patterns, coping with stress, state- and trait-anxiety, depression, and fatigue. In parallel, experts will use the Hamilton Depression Rating Scale to determine and rate participants' symptoms of depression.; The present study will be the first to investigate and compare the impact of two different exercise modalities, namely endurance and resistance training, on physical fitness and dimensions of well-being, and sleep among patients with HGG who underwent neurosurgery followed by adjuvant radiotherapy, chemotherapy, or chemoradiotherapy. Importantly, unlike the majority of previous studies, the control condition consists of an active set-up to detect possible factual beneficial effects of exercise training, irrespective of social interactions

    Stress-buffering effects of physical activity and cardiorespiratory fitness on metabolic syndrome: A prospective study in police officers

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    Metabolic syndrome (MetS) is a worldwide health concern related to cardiovascular disease. Stress at work increases the risk for MetS, whereas physical activity and cardiorespiratory fitness (CF) have been shown to be potential buffers against stress. The aim of this study was to test the stress-buffering effects of physical activity and CF on the relationship between work stress and MetS. In a prospective study, we followed 97 police officers (mean age = 39.7 years; mean body mass index = 25.74 kg/m2) over one year and assessed MetS, as defined by the National Cholesterol Education Program Adult Treatment Panel III. Stress at work was measured with the Job Content Questionnaire, as well as the Effort-Reward Imbalance Questionnaire. Physical activity was assessed objectively via 7-day accelerometry. CF was assessed with the Astrand bicycle ergometer test. Hierarchical linear regression models were carried out to predict MetS at follow-up (mean overall MetS score = 1.22), after controlling for baseline levels and sociodemographic background (mean overall MetS score = 1.19). Higher CF levels were significantly associated with lower MetS risk at follow-up ( β = -.38). By contrast, no main effects were found for physical activity and work stress. However, high effort and demand were significantly correlated with increased blood pressure (effort: r = .23 for systolic blood pressure; r = .21 for diastolic blood pressure) and waist circumference (effort: r = .26; demand: r = .23). Moreover, no significant interaction effects occurred between work stress and CF/physical activity. The results emphasize the importance of high levels of CF in the prevention of MetS in police officers. Accordingly, provision of regular training opportunities and repeated CF testing should be considered as a strategy in overall corporate health promotion

    The relation between sleep and pain among a non-clinical sample of young adults

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    Poor sleep is linked to poorer daily functioning and increased risk of psychiatric symptoms. With respect to pain, the relation is bi-directional; poor sleep exacerbates pain, while greater pain adversely affects sleep. Moreover, perception of pain is subject to cognitive-emotional processes. Surprisingly, no data are available from non-clinical samples of young adults. The aim of the present study was therefore to investigate the relation between sleep and pain as a function of quality of life and depressive symptoms in young adults. The direction of influence between sleep and pain was statistically tested with two different structural equation models (SEMs). A total of 862 participants (639 women, 223 men; mean age: 24.67; SD=5.91) completed a series of validated self-report questionnaires assessing sleep, quality of life, depressive symptoms and cognitive-emotional elaboration of pain. Sleep, pain, quality of life, and depressive symptoms were interrelated. The first SEM suggested both a direct and an indirect influence of pain on sleep, whereas the second SEM suggested that sleep had only an indirect influence on pain. Irrespective of the SEM, the relation between sleep and cognitive-emotional elaboration of pain was mediated by quality of life and depressive symptoms. For a non-clinical sample of young adults, findings did support the bi-directional relation between poor sleep and increased cognitive-emotional elaboration of pain, though other cognitive-emotional processes such as depressive symptoms and quality of life should be taken into accoun

    Associative Learning of Stimuli Paired and Unpaired With Reinforcement: Evaluating Evidence From Maggots, Flies, Bees, and Rats

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    Finding rewards and avoiding punishments are powerful goals of behavior. To maximize reward and minimize punishment, it is beneficial to learn about the stimuli that predict their occurrence, and decades of research have provided insight into the brain processes underlying such associative reinforcement learning. In addition, it is well known in experimental psychology, yet often unacknowledged in neighboring scientific disciplines, that subjects also learn about the stimuli that predict the absence of reinforcement. Here we evaluate evidence for both these learning processes. We focus on two study cases that both provide a baseline level of behavior against which the effects of associative learning can be assessed. Firstly, we report pertinent evidence from Drosophila larvae. A re-analysis of the literature reveals that through paired presentations of an odor A and a sugar reward (A+) the animals learn that the reward can be found where the odor is, and therefore show an above-baseline preference for the odor. In contrast, through unpaired training (A/+) the animals learn that the reward can be found precisely where the odor is not, and accordingly these larvae show a below-baseline preference for it (the same is the case, with inverted signs, for learning through taste punishment). In addition, we present previously unpublished data demonstrating that also during a two-odor, differential conditioning protocol (A+/B) both these learning processes take place in larvae, i.e., learning about both the rewarded stimulus A and the non-rewarded stimulus B (again, this is likewise the case for differential conditioning with taste punishment). Secondly, after briefly discussing published evidence from adult Drosophila, honeybees, and rats, we report an unpublished data set showing that relative to baseline behavior after truly random presentations of a visual stimulus A and punishment, rats exhibit memories of opposite valence upon paired and unpaired training. Collectively, the evidence conforms to classical findings in experimental psychology and suggests that across species animals associatively learn both through paired and through unpaired presentations of stimuli with reinforcement – with opposite valence. While the brain mechanisms of unpaired learning for the most part still need to be uncovered, the immediate implication is that using unpaired procedures as a mnemonically neutral control for associative reinforcement learning may be leading analyses astray

    Vibrational Density Matrix Renormalization Group

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    Variational approaches for the calculation of vibrational wave functions and energies are a natural route to obtain highly accurate results with controllable errors. However, the unfavorable scaling and the resulting high computational cost of standard variational approaches limit their application to small molecules with only few vibrational modes. Here, we demonstrate how the density matrix renormalization group (DMRG) can be exploited to optimize vibrational wave functions (vDMRG) expressed as matrix product states. We study the convergence of these calculations with respect to the size of the local basis of each mode, the number of renormalized block states, and the number of DMRG sweeps required. We demonstrate the high accuracy achieved by vDMRG for small molecules that were intensively studied in the literature. We then proceed to show that the complete fingerprint region of the sarcosyn-glycin dipeptide can be calculated with vDMRG.Comment: 21 pages, 5 figures, 4 table
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