160 research outputs found

    Effekte der Einnahme von Natriumbikarbonat auf die Langzeit-Ausdauerleistungsfähigkeit von gut trainierten Radsportlern

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    Risk of SARS-CoV-2 transmission from on-field player contacts in amateur, youth and professional football (soccer)

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    Objective To investigate the risk of transmission among potentially infectious SARS-CoV-2-positive football players while participating in training or matches at amateur, youth and professional levels. Methods Between August 2020 and March 2021, football players who tested positive for SARS-CoV-2 and participated in matches or training during the period of potential contagiousness were identified through media search (professional level) and a nationwide registry in Germany (amateur and youth level) to determine symptoms, source of infection and hygiene measures adopted. The definition of potentially infectious players was based on the time of a positive PCR testing and symptom onset. Transmission-relevant contacts on the pitch were evaluated through doubly reviewed video analysis. Results Out of 1247 identified football matches and training sessions (1071 amateur and youth level, 176 professional level), 104 cases (38 training sessions, 66 matches) with 165 potentially infectious players were detected. Follow-up PCR testing at the professional level (44 cases) revealed no transmission. At the amateur and youth level, the combination of partial PCR testing (31 of 60 cases) and symptom monitoring within 14 days post-exposure (46 of 60 cases) identified 2 of 60 matches in which follow-up infections occurred that were attributed to non-football activities. This is consistent with the video analysis of 21 matches demonstrating frontal contacts were <1 per player-hour (88%, 30 of 34 players), each lasting no longer than 3 s. Conclusion On-field transmission risk of SARS-CoV-2 in football is very low. Sources of infections in football players are most likely not related to activities on the pitch

    Dwarfs on the Shoulders of Giants: Bayesian Analysis With Informative Priors in Elite Sports Research and Decision Making

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    While sample sizes in elite sports are necessarily small, so are the effects that may be relevant. This conundrum is complicated by an understandable reluctance of athletes to comply with extensive study requirements. In Bayesian analyses, pre-existing knowledge (e.g., from sub-elite trials) can be formally included to supplement scarce data. Moreover, some design specifics for small sample research extend to the extreme case of a single subject. This provides the basis for actionable feedback (e.g., about individual responses) thereby incentivising participation. As a proof-of-concept, we conducted a replicated cross-over trial on the effect of cold-water immersion (CWI) on sprint performance recovery in soccer players. Times for 30 m linear sprint and the initial 5 m section, respectively, were measured by light gates before and 24 h after induction of fatigue. Data were analysed by Bayesian and by standard frequentist methods. Informative priors are based on a published metaanalysis. Seven players completed the trial. Sprint performance was 4.156 ± 0.193 s for 30 m linear sprint and 0.978 ± 0.064 s for the initial 5 m section. CWI improved recovery of sprint time for the initial 5 m section (difference to control: -0.060 ± 0.060 s, p = 0.004) but not for the full 30 m sprint (0.002 ± 0.115 s, p = 0.959), with general agreement between Bayesian and frequentist interval estimates. On the individual level, relevant differences between analytical approaches were present for most players. Changes in the two performance measures are correlated (p = 0.009) with a fairly good reproducibility of individual response patterns. Bayesian analyses with informative priors may be a practicable and meaningful option particularly for very small samples and when the analytical aim is decision making (use / don't use in the specific setting) rather than generalizable inference

    Aboveground biomass and carbon stock of the riparian vegetation in the Danube Delta

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    Intact wetlands can act as carbon sinks and mitigate increased amounts of greenhouse gases in the atmosphere following climate change. In addition to organic soils, the riparian vegetation plays an important role in carbon storage and cycling within wetlands. In the context of the project ‘EDAPHIC-BLOOM Danube’, the riparian vegetation in the Danube Delta was investigated. Preliminary results show differences in aboveground biomass and carbon content between softwood and hardwood riparian forests and artificial poplar plantations. The aboveground biomass in the reed beds is much lower per plot, but due to their huge extension, they are very important for carbon storage

    k-strip: A novel segmentation algorithm in k-space for the application of skull stripping

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    Objectives: Present a novel deep learning-based skull stripping algorithm for magnetic resonance imaging (MRI) that works directly in the information rich k-space. Materials and Methods: Using two datasets from different institutions with a total of 36,900 MRI slices, we trained a deep learning-based model to work directly with the complex raw k-space data. Skull stripping performed by HD-BET (Brain Extraction Tool) in the image domain were used as the ground truth. Results: Both datasets were very similar to the ground truth (DICE scores of 92\%-98\% and Hausdorff distances of under 5.5 mm). Results on slices above the eye-region reach DICE scores of up to 99\%, while the accuracy drops in regions around the eyes and below, with partially blurred output. The output of k-strip often smoothed edges at the demarcation to the skull. Binary masks are created with an appropriate threshold. Conclusion: With this proof-of-concept study, we were able to show the feasibility of working in the k-space frequency domain, preserving phase information, with consistent results. Future research should be dedicated to discovering additional ways the k-space can be used for innovative image analysis and further workflows.Comment: 11 pages, 6 figures, 2 table

    Automatic vocalisation-based detection of fragile X syndrome and Rett syndrome

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    Fragile X syndrome (FXS) and Rett syndrome (RTT) are developmental disorders currently not diagnosed before toddlerhood. Even though speech-language deficits are among the key symptoms of both conditions, little is known about infant vocalisation acoustics for an automatic earlier identification of affected individuals. To bridge this gap, we applied intelligent audio analysis methodology to a compact dataset of 4454 home-recorded vocalisations of 3 individuals with FXS and 3 individuals with RTT aged 6 to 11 months, as well as 6 age- and gender-matched typically developing controls (TD). On the basis of a standardised set of 88 acoustic features, we trained linear kernel support vector machines to evaluate the feasibility of automatic classification of (a) FXS vs TD, (b) RTT vs TD, (c) atypical development (FXS+RTT) vs TD, and (d) FXS vs RTT vs TD. In paradigms (a)–(c), all infants were correctly classified; in paradigm (d), 9 of 12 were so. Spectral/cepstral and energy-related features were most relevant for classification across all paradigms. Despite the small sample size, this study reveals new insights into early vocalisation characteristics in FXS and RTT, and provides technical underpinnings for a future earlier identification of affected individuals, enabling earlier intervention and family counselling

    Effects of face masks on performance and cardiorespiratory response in well-trained athletes

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    Background During the COVID-19 pandemic, compulsory masks became an integral part of outdoor sports such as jogging in crowded areas (e.g. city parks) as well as indoor sports in gyms and sports centers. This study, therefore, aimed to investigate the effects of medical face masks on performance and cardiorespiratory parameters in athletes. Methods In a randomized, cross-over design, 16 well-trained athletes (age 27 ± 7 years, peak oxygen consumption 56.2 ± 5.6 ml kg−1 min−1, maximum performance 5.1 ± 0.5 Watt kg−1) underwent three stepwise incremental exercise tests to exhaustion without mask (NM), with surgical mask (SM) and FFP2 mask (FFP2). Cardiorespiratory and metabolic responses were monitored by spiroergometry and blood lactate (BLa) testing throughout the tests. Results There was a large effect of masks on performance with a significant reduction of maximum performance with SM (355 ± 41 Watt) and FFP2 (364 ± 43 Watt) compared to NM (377 ± 40 Watt), respectively (p < 0.001; ηp2 = 0.50). A large interaction effect with a reduction of both oxygen consumption (p < 0.001; ηp2 = 0.34) and minute ventilation (p < 0.001; ηp2 = 0.39) was observed. At the termination of the test with SM 11 of 16 subjects reported acute dyspnea from the suction of the wet and deformed mask. No difference in performance was observed at the individual anaerobic threshold (p = 0.90). Conclusion Both SM and to a lesser extent FFP2 were associated with reduced maximum performance, minute ventilation, and oxygen consumption. For strenuous anaerobic exercise, an FFP2 mask may be preferred over an SM

    The rostro-caudal gradient in the prefrontal cortex and its modulation by subthalamic deep brain stimulation in Parkinson’s disease

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    Acknowledgements The authors thank Benjamin Rahm (University of Freiburg) and Michael Fox (Harvard Medical School) for valuable comments on a previous version of this manuscript. This work was supported by a grant of the BrainLinks-BrainTools Cluster of Excellence funded by the German Research Foundation (DFG, grant number EXC 1086) to C.P.K., F.A., T.P., B.O.S., C.W, and V.A.C.; A.H. was supported by the German Research Foundation (Deutsche Forschungsgemeinschaft, Emmy Noether Stipend 410169619 and 424778381 – TRR 295) as well as Deutsches Zentrum für Luft- und Raumfahrt (DynaSti grant within the EU Joint Programme Neurodegenerative Disease Research, JPND). Funding Open Access funding enabled and organized by Projekt DEAL.Peer reviewedPublisher PD

    Evaluation of an OSCE’s implementation and a two-step approach for a theoretical and practical training program in Obstetrics and Gynecology

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    Objective structured clinical examination (OSCE) is a well-known assessment method to evaluate clinical skills and competence in healthcare. Following the recently reformed National Competence-Based Catalog of Learning Objectives in Medicine, the implementation of this assessment method in the training program for medical students is now obligatory in Germany. This major change requires a reorganization not only of the training programs but also of the students themselves and the way they learn. We performed a poll evaluating the students’ opinions regarding these major changes and the implementation of the OSCE with a new training program. To implement this assessment method and to evaluate the OSCE, Kern’s six-step approach comprising (1) problem identification and general needs assessment, (2) needs assessment of the targeted learners, (3) goals and objectives, (4) educational strategies, (5) implementation, and (6) evaluation and feedback was applied. To evaluate and gather feedback, a poll was used to analyze the student’s opinions regarding OSCE in gynecology and obstetrics and OSCE in general, in addition to the regular analysis of the students’ results. To reform the educational strategy, a two-step approach was developed: First, the students completed the regular training program and a written examination, and second, they participated in a 1-week clerkship, in small group teaching, and in the OSCE. The OSCE stations were developed primarily based on the National Competence-Based Catalog and the German Catalog of Learning Objectives in Medicine, as well as on the feedback of experts reflecting their expectations for physicians beginning their careers. The students performed well in the OSCE and gave positive feedback regarding this examination method. Furthermore, they welcomed the upcoming changes by considering OSCE a valuable assessment tool, and they showed appreciation for the two-step approach by supporting the combination of an OSCE and a written examination. Thus, this article presents the implementation of an OSCE and a strategy for the adaptation of the curriculum to fulfill the new OSCE requirements and—to our knowledge—reveals students’ primary opinions regarding the changes in their medical training program for the first time
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