Self-assessed tactical skills in tennis players:Psychometric evaluation of the Tactical Skills Questionnaire in Tennis

To our knowledge, no feasible, valid and reliable instrument exists to examine tactical skills over the course of multiple training and game situations in tennis yet. Therefore, the aim of this study was to develop and evaluate the psychometric properties of the Tactical Skills Questionnaire in Tennis (TSQT). The TSQT is a new instrument with closed-ended questions designed to examine tactical skills in tennis players. Participants were 233 competitive tennis players (age: 17.06 ± 4.74 years) competing on national or regional levels. With a principal component analysis (PCA) we identified four theoretically meaningful subscales for the 31-item TSQT: “Anticipation and positioning,” “Game intelligence and adaptability,” “Decision-making,” and “Recognizing game situations” and confirmed them with a confirmatory factor analysis (CFA) (χ2 = 527.02, df = 426, p 0.05). Relative test-retest reliability was moderate with ICC values ranging from 0.65 to 0.71. National players outperformed regional players on the subscales “Game intelligence and adaptability,” “Decision-making,” and “Recognizing game situations” (p < 0.05), and there was a trend toward significance for “Anticipation and positioning” (p = 0.07). This study supported the psychometric properties of the TSQT. Evaluating tactical skills with the TSQT provides players, coaches and other professionals with insight in players' self-assessed tactical skills over the course of multiple training and game situations. It creates the opportunity for players to reflect on their skills and detect personal development areas with their coach. We advise to use this information as input for tailor-made training programs

Tunable quantum interferometer for correlated moir\'e electrons

Magic-angle twisted bilayer graphene (MATBG) can host an intriguing variety of gate-tunable correlated states, including superconducting and correlated insulator states. Junction-based superconducting devices, such as Josephson junctions and SQUIDs, have been introduced recently and enable the exploration of the charge, spin, and orbital nature of superconductivity and the coherence of moir\'e electrons in MATBG. However, complementary fundamental coherence effects - in particular, the Little-Parks effect in a superconducting and the Aharonov-Bohm effect in a normal conducting ring - remained to be observed. Here, we report the observation of both these phenomena in a single gate-defined ring device where we can embed a superconducting or normal conducting ring in a correlated or band insulator. We directly observe the Little-Parks effect in the superconducting phase diagram as a function of density and magnetic field, confirming the effective charge of $2e$. By measuring the Aharonov-Bohm effect, we find that in our device, the coherence length of normal conducting moir\'e electrons exceeds a few microns at 50 mK. Surprisingly, we also identify a regime characterized by $h/e$-periodic oscillations but with superconductor-like nonlinear transport. Taken together, these experiments establish a novel device platform in MATBG, and more generally in tunable 2D materials, to unravel the nature of superconductivity and other correlated quantum states in these materials

Bekendheid, benutting en effectiviteit van professionaliseringsprikkels in het voortgezet onderwijs:Rapportage deelstudie 2

Rapportage behorend bij NRO-project 'Bestuurlijk Vermogen en de werking van professionaliseringsprikkels in het voortgezet onderwijs

Genetics of rheumatoid arthritis contributes to biology and drug discovery

A major challenge in human genetics is to devise a systematic strategy to integrate disease-associated variants with diverse genomic and biological datasets to provide insight into disease pathogenesis and guide drug discovery for complex traits such as rheumatoid arthritis (RA)1. Here, we performed a genome-wide association study (GWAS) meta-analysis in a total of >100,000 subjects of European and Asian ancestries (29,880 RA cases and 73,758 controls), by evaluating ~10 million single nucleotide polymorphisms (SNPs). We discovered 42 novel RA risk loci at a genome-wide level of significance, bringing the total to 1012–4. We devised an in-silico pipeline using established bioinformatics methods based on functional annotation5, cis-acting expression quantitative trait loci (cis-eQTL)6, and pathway analyses7–9 – as well as novel methods based on genetic overlap with human primary immunodeficiency (PID), hematological cancer somatic mutations and knock-out mouse phenotypes – to identify 98 biological candidate genes at these 101 risk loci. We demonstrate that these genes are the targets of approved therapies for RA, and further suggest that drugs approved for other indications may be repurposed for the treatment of RA. Together, this comprehensive genetic study sheds light on fundamental genes, pathways and cell types that contribute to RA pathogenesis, and provides empirical evidence that the genetics of RA can provide important information for drug discovery