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Variable transcription of the cardiac sodium channel gene is a candidate mechanism determining arrhythmia susceptibility. We have previously cloned and characterized the core promoter and flanking region of SCN5A, encoding the cardiac sodium channel. Loss-of-function mutations in this gene have been reported in ∼20% of patients with Brugada syndrome, an inherited cardiac electrical disorder associated with a high incidence of life-threatening arrhythmias. In this study, we identified DNA variants in the proximal 2.8 kb promoter region of SCN5A and determined their frequency in 1121 subjects. This population consisted of 88 Brugada syndrome patients with no SCN5A coding region mutation, and 1033 anonymized subjects from various ethnicities. Variant promoter activity was assayed in CHO cells and neonatal cardiomyocytes by transient transfection of promoter–reporter constructs. Single-nucleotide polymorphisms (SNPs) were identified at ∼1/200 base pairs which are: 11 in the 5′-flanking region, 1 in exon 1, and 5 in intron 1. In addition, a haplotype consisting of two SNPs in complete linkage disequilibrium was identified. Minor allele frequencies were >5% in at least one ethnic panel at 5/19 polymorphic sites. In vitro functional analysis in cardiomyocytes identified four variants with significantly (P<0.05) reduced reporter activity (up to 63% reduction). The largest changes were seen with c.−225−1790 G>A, which reduced reporter activity by 62.8% in CHO cells and 55% in cardiomyocytes. From these results, we can conclude that the SCN5A core promoter includes multiple DNA polymorphisms with altered in vitro activity, further supporting the concept of interindividual variability in transcription of this cardiac ion channel gene.European Journal of Human Genetics (2008) 16, 350–357; doi:10.1038/sj.ejhg.5201952; published online 5 December 2007 [ABSTRACT FROM AUTHOR]

Athlete age-grouping and age-banding has been shown to impact sport participation and athlete development. The current study examined the impact of within-year (WYEs) and between-year effects (BYEs), and their interactions with playing position, on female participation in elite German football. The sample of 1,378 German first-league players revealed expected participation inequities within-year with relatively older players being over-represented and younger players being under-represented. From a between-year perspective there were no participation differences. The interaction of WYEs and BYEs revealed an over-representation of odd-year players in Q1, and Q2 in even years. With respect to the interaction between year effects and playing position, for WYEs the expected effect was present for goalkeepers and defenders, while there was no significant interaction for BYEs. Overall, the results offer insight regarding the impact of system structure on participation, and highlight unique characteristics associated with playing positions., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2024 Smith, Koopmann, Weir and Schorer.)

Background: Hemoglobinopathies, the most common inherited blood disorder, are frequently underdiagnosed. Early identification of carriers is important for genetic counseling of couples at risk. The aim of this study was to develop and validate a novel machine learning model on a multicenter data set, covering a wide spectrum of hemoglobinopathies based on routine complete blood count (CBC) testing., Methods: Hemoglobinopathy test results from 10 322 adults were extracted retrospectively from 8 Dutch laboratories. eXtreme Gradient Boosting (XGB) and logistic regression models were developed to differentiate negative from positive hemoglobinopathy cases, using 7 routine CBC parameters. External validation was conducted on a data set from an independent Dutch laboratory, with an additional external validation on a Spanish data set (n = 2629) specifically for differentiating thalassemia from iron deficiency anemia (IDA)., Results: The XGB and logistic regression models achieved an area under the receiver operating characteristic (AUROC) of 0.88 and 0.84, respectively, in distinguishing negative from positive hemoglobinopathy cases in the independent external validation set. Subclass analysis showed that the XGB model reached an AUROC of 0.97 for β-thalassemia, 0.98 for α0-thalassemia, 0.95 for homozygous α+-thalassemia, 0.78 for heterozygous α+-thalassemia, and 0.94 for the structural hemoglobin variants Hemoglobin C, Hemoglobin D, Hemoglobin E. Both models attained AUROCs of 0.95 in differentiating IDA from thalassemia., Conclusions: Both the XGB and logistic regression model demonstrate high accuracy in predicting a broad range of hemoglobinopathies and are effective in differentiating hemoglobinopathies from IDA. Integration of these models into the laboratory information system facilitates automated hemoglobinopathy detection using routine CBC parameters., (© Association for Diagnostics & Laboratory Medicine 2024. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Tools that provide a fair estimate of young table tennis players' potential and their chances to succeed will support making decisions whether to commit to an extensive development program and the accompanying lifestyle. Consequently, this study included two research questions (RQ) to evaluate the capability of the Dutch perceptuo-motor skills assessment to predict competition participation/drop-out (RQ1) and competition performance (RQ2) in young table tennis players (n = 39; 7-11 years) using a tracking period of 9 years. The perceptuo-motor skills assessment consists of eight tests assessing gross motor function (i.e., sprint, agility, vertical jump) and ball control (i.e., speed while dribbling, aiming at target, ball skills, throwing a ball and eye-hand coordination). A Cox regression analysis demonstrated that a higher level of ball control was associated with a lower risk to drop-out from table tennis competition. The eye-hand coordination test appeared to be most suitable since it was the only test included in the multivariable Cox regression model (HR = .908; p = .001) (RQ1). Similarly, a multilevel regression analysis showed that a higher level of ball control was associated with a higher future competition performance. The eye-hand coordination and aiming at target tests were included in the multivariable multilevel model (p < 0.05; R2 = 36.4%) (RQ2). This evaluation demonstrates promising prospects for the perceptuo-motor skills assessment to be included in a talent development programme. Future studies are needed to obtain valid thresholds scores and clarify the predictive value in a larger sample of youth competition players., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Faber et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Research on talent in sports aims to identify predictors of future performance. This study retrospectively investigated 1) relationships between young handball field players' technical throwing skills and (a) their potential nomination to youth national teams and (b) their long-term career attainment 10 years later, and 2) associations between nomination status and career attainment., Results: Results from retrospectively predicting nomination status and career attainment using logistic regression analyses show that technical throwing skills were partly able to explain players' nomination status (Nagelkerke R 2 : females 9.2%, males 13.1%) and career attainment (Nagelkerke R 2 : 9.8% for female players). Here, variables throwing velocity and time on exercise showed statistically significant effects. In addition, nomination status and career attainment were shown to be associated using chi-square tests (w of .37 and .23 for female and male players, respectively) and nomination status as a predictor increased the prediction of career attainment remarkably (Nagelkerke R 2 : females 20.3%, males 12.7%)., Conclusions: Given these results, basic technical throwing skills may serve rather as a prerequisite in this age group on national level, emphasizing its importance already on lower levels and in younger age groups. Furthermore, advantages from entering the national TID system early especially for females are discussed., (© 2021. The Author(s).)

Background: The assessment of technical skills as part of a multidimensional approach for talent identification and development in sports seems promising, especially in a technique-based sport like table tennis. However, current instruments mostly focus on a single element of technical skills, mainly use quantitative outcomes, and/or are not developed for talent purposes. Practice would benefit from a new instrument using a more ecologically valid approach. Thus, the purpose of this study was to identify the essential elements of technical skills in young table tennis players and to establish a first tool while using a multi-methods study design including an archive search for professional literature, a systematic search for scientific literature, as well as ten in-depth interviews with expert coaches., Results: This approach taken ensured empirical findings to be combined with knowledge and experiences from the practical field and detailed explications by high-level expert coaches. Results for the literature searches yielded 23 professional and 21 scientific articles while data saturation was reached through all ten interviews. The triangulation process resulted in two general (i.e., individuality, interconnection between elements) and five specific (i.e., bat grip, ready position, footwork/body positioning, service, stroke) elements of technical skills in young table tennis players. In addition, criteria for both flawed and excellent executions were identified for each of the five specific elements. Finally, these results were used to create an observation sheet usable for an assessment during competition., Conclusions: This study revealed the crucial elements of technical skills that should be taken into account when assessing sport-specific technical skills of youth table tennis players (8-12 years). Moreover, it provided concise descriptions of what is considered to be flawed or excellent executions of technical skills. Based on these findings, a first observation sheet, the Oldenburg observation sheet for Table Tennis Technique (O3T), was created to be used for the assessment of the current technical skill level within a competitive context at the early stage of a table tennis player's career. Future research should focus on its measurement properties and its value within a multidimensional assessment for talent purposes.

The purpose of this study was to investigate fatigue-related changes in spinal kinematics, kinetics, and muscle activity of back muscles during a 2000 m all-out ergometer rowing performance. We analyzed ten male subjects with experience in both rowing and CrossFit exercises. We applied a novel kinematic method to describe spine curvature, determined bending moments at the spine using inverse dynamics and collected EMG data. We identified significant increases in spine curvature of the thoracic spine (i.e. vertebrae Th6 to Th11). Significant increases in peak moments were found only at the upper spine (i.e. Th2). We found no significant changes in EMG amplitudes, while the frequency analysis showed significant decreases in the mean frequencies (MNF) for the M. latissimus dorsi, the M. trapezius descendens and the M. deltoideus posterior. No significant changes on MNF were found for the Mm. erector spinae. We hypothesize that the significant increase in curvature for the thoracic spine is connected to the fatigued back muscles, especially the Mm. trapezius descendens, and might lead to an unbalanced loading of intervertebral discs and other structures. These findings are particularly important for athletes and coaches in CrossFit as strenuous rowing intervals are combined with technical exercises with high loads on the back and spine (e.g. power and Olympic lifting) leading to impaired muscular stabilization and potentially to an increased injury risk.

Treadmills are essential to the study of human and animal locomotion as well as for applied diagnostics in both sports and medicine. The quantification of relevant biomechanical and physiological variables requires a precise regulation of treadmill belt velocity (TBV). Here, we present a novel method for time-efficient tracking of TBV using standard 3D motion capture technology. Further, we analyzed TBV fluctuations of four different treadmills as seven participants walked and ran at target speeds ranging from 1.0 to 4.5 m/s. Using the novel method, we show that TBV regulation differs between treadmill types, and that certain features of TBV regulation are affected by the subjects' body mass and their locomotion speed. With higher body mass, the TBV reductions in the braking phase of stance became higher, even though this relationship differed between locomotion speeds and treadmill type (significant body mass × speed × treadmill type interaction). Average belt speeds varied between about 98 and 103% of the target speed. For three of the four treadmills, TBV reduction during the stance phase of running was more intense (> 5% target speed) and occurred earlier (before 50% of stance phase) unlike the typical overground center of mass velocity patterns reported in the literature. Overall, the results of this study emphasize the importance of monitoring TBV during locomotor research and applied diagnostics. We provide a novel method that is freely accessible on Matlab's file exchange server ("getBeltVelocity.m") allowing TBV tracking to become standard practice in locomotion research.

Despite the importance of technique and tactics for athlete performance, there has been surprisingly little research on the value of these skills in talent identification and development. This study investigated the relationship between coaches' early notational analyses of female youth handball players and the long-term success of these athletes. Participants included sixty-eight female handball players involved in a talent selection camp in Germany when they were between 12 and 14 years of age (mean = 14.42, SD  = 0.42). All subsequently ended up as non-, semi- or professional adult players. During the initial selection camp, participants were evaluated on a range of quantitative and qualitative measures of technical and tactical skill. Results indicated significant differences between the groups, but only for the number of actions taken, not for the quality of those actions. While this seems counterintuitive, it may reflect the likelihood that more skilled and/or talented players take more actions. Further work is necessary to explore the validity and implications of these findings.

Background: Talent identification and development (TID) programs aim to identify players with the greatest potential for long-term success. Previous research suggests that the assessment of sport-specific technical skills is valuable for discriminating between more and less skilled individuals and/or for predicting future performance., Objective: This review aims to provide an overview on both the instruments used to assess sport-specific technical skills and their discriminatory, explanatory and/or predictive findings in the context of TID., Methods: Electronic searches were conducted in PubMed, Web of Knowledge, SPORTDiscus, SURF and Scopus (January 1990-October 2019). Search terms covered the areas of sport, technical skills assessment, performance, skill level and youth. In the end, 59 relevant studies were identified and evaluated., Results: The results highlight the widespread and important role of technical skills in TID; almost all studies (93%) reported discriminatory, explanatory and/or predictive benefits for the assessment of sport-specific technical skills. Analyzing and categorizing the number of assessment methods applied in the studies (n = 69) according to their method type ('technique-related' or 'outcome-related' variables) and method set-up ('experimental' or 'competition' data acquisition environment) indicated a clear tendency towards 'outcome-related' (73%) and 'experimental' (75%) assessment methods. We also found a strong overrepresentation of studies assessing cross-sectional data (75%) in soccer (53%) in male samples (74% of studies reporting subjects' sex) from European countries (64%)., Conclusions: On the one hand, our findings demonstrate the great capability of sport-specific technical skills assessments to discriminate different performance levels and predict future performance in TID activities. On the other hand, this review highlights the focus on 'outcome-related' and 'experimental' methods in specific populations and, consequently, the limited knowledge in other areas. Here, the application of 'technique-related' and 'competition' methods appears promising for adding new knowledge, especially in the light of technological advances.

Purpose: In sports games, coaches often use tactic boards to present tactical instructions during time-outs (e.g., 20 s to 60 s in basketball). Instructions should be presented in a way that enables fast and errorless information processing for the players. The aim of this study was to test the effect of different orientations of visual tactical displays on observation time and execution performance. High affordances in visual-spatial transformation (e.g., mental rotation processes) might impede information processing and might decrease execution performance with regard to the instructed playing patterns., Method: In a within-subjects design with 1 factor, 10 novice students were instructed with visual tactical instructions of basketball playing patterns with different orientations either showing the playing pattern with low spatial disparity to the players' on-court perspective (basket on top) or upside down (basket on bottom)., Results: The self-chosen time for watching the pattern before execution was significantly shorter and spatial accuracy in pattern execution was significantly higher when the instructional perspective and the real perspective on the basketball court had a congruent orientation., Conclusion: The effects might be explained by interfering mental rotation processes that are necessary to transform the instructional perspective into the players' actual perspective while standing on the court or imagining themselves standing on the court. According to these results, coaches should align their tactic boards to their players' on-court viewing perspective.