Injury Risk Estimation Expertise Assessing the ACL Injury Risk Estimation Quiz

Background: Available methods for screening anterior cruciate ligament (ACL) injury risk are effective but limited in application as they generally rely on expensive and time-consuming biomechanical movement analysis. A potential efficient alternative to biomechanical screening is skilled movement analysis via visual inspection (ie, having experts estimate injury risk factors based on observations of athletes’ movements). Purpose: To develop a brief, valid psychometric assessment of ACL injury risk factor estimation skill: the ACL Injury Risk Estimation Quiz (ACL-IQ). Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: A total of 660 individuals participated in various stages of the study, including athletes, physicians, physical therapists, athletic trainers, exercise science researchers/students, and members of the general public in the United States. The ACL-IQ was fully computerized and made available online (www.ACL-IQ.org). Item sampling/reduction, reliability analysis, cross-validation, and convergent/discriminant validity analysis were conducted to optimize the efficiency and validity of the assessment. Results: Psychometric optimization techniques identified a short (mean time, 2 min 24 s), robust, 5-item assessment with high reliability (test-retest: r = 0.90) and consistent discriminability (average difference of exercise science professionals vs general population: Cohen d = 1.98). Exercise science professionals and general population individuals scored 74% and 53% correct, respectively. Convergent and discriminant validity was demonstrated. Scores on the ACL-IQ were most associated with ACL knowledge and various cue utilities and were least associated with domain-general spatial/decision-making ability, personality, or other demographic variables. Overall, 23% of the total sample (40% exercise science professionals; 6% general population) performed better than or equal to the ACL nomogram. Conclusion: This study presents the results of a systematic approach to assess individual differences in ACL injury risk factor estimation skill; the assessment approach is efficient (ie, it can be completed in\3 min) and psychometrically robust. The results provide evidence that some individuals have the ability to visually estimate ACL injury risk factors more accurately than other instrument-based ACL risk estimation methods (ie, ACL nomogram). The ACL-IQ provides the foundation for assessing the efficacy of observational ACL injury risk factor assessment (ie, does simple skilled visual inspection reduce ACL injuries?). It also provides a representative task environment that can be used to increase our understanding of the perceptual-cognitive mechanisms underlying observational movement analysis and to improve injury risk assessment performance

Geometric Effects and Computation in Spin Networks

When initially introduced, a Hamiltonian that realises perfect transfer of a quantum state was found to be analogous to an x-rotation of a large spin. In this paper we extend the analogy further to demonstrate geometric effects by performing rotations on the spin. Such effects can be used to determine properties of the chain, such as its length, in a robust manner. Alternatively, they can form the basis of a spin network quantum computer. We demonstrate a universal set of gates in such a system by both dynamical and geometrical means

Medically Important Venomous Animals: Biology, Prevention, First Aid, and Clinical Management

Venomous animals are a significant health problem for rural populations in many parts of the world. Given the current level of the international mobility of individuals and the inquisitiveness of travelers, clinicians and travel clinics need to be able to give advice on the prevention, first aid, and clinical management of envenoming. Health professionals often feel overwhelmed by the taxonomy of venomous animals; however, venomous animals can be grouped, using a simple set of criteria, into cnidarians, venomous fish, sea snakes, scorpions, spiders, hymenoterans, and venomous terrestrial snakes. Geographic distribution, habitats, and circumstances of accidents further reduce the range of culprits that need to be considered in any single event. Clinical management of envenomed patients relies on supportive therapy and, if available, specific antivenoms. Supplies of life-saving antivenoms are scarce, and this scarcity particularly affects rural populations in resource-poor settings. Travel clinics and hospitals in highly industrialized areas predominantly see patients with injuries caused by accidents involving marine animals: in particular, stings by venomous fish and skin damage caused by jellyfish. However, globally, terrestrial venomous snakes are the most important group of venomous animal

Scaling of the low temperature dephasing rate in Kondo systems

We present phase coherence time measurements in quasi-one-dimensional Ag wires doped with Fe Kondo impurities of different concentrations $n_s$. Due to the relatively high Kondo temperature $T_{K}\approx 4.3K$ of this system, we are able to explore a temperature range from above $T_{K}$ down to below $0.01 T_{K}$. We show that the magnetic contribution to the dephasing rate $\gamma_m$ per impurity is described by a single, universal curve when plotted as a function of $(T/T_K)$. For $T>0.1 T_K$, the dephasing rate is remarkably well described by recent numerical results for spin $S=1/2$ impurities. At lower temperature, we observe deviations from this theory. Based on a comparison with theoretical calculations for $S>1/2$, we discuss possible explanations for the observed deviations.Comment: 4 pages, 3 figures, submitted to Phys. Rev. Let

Effects of the gg-factor in semi-classical kinetic plasma theory

A kinetic theory for spin plasmas is put forward, generalizing those of previous authors. In the model, the ordinary phase space is extended to include the spin degrees of freedom. Together with Maxwell's equations, the system is shown to be energy conserving. Analysing the linear properties, it is found that new types of wave-particle resonances are possible, that depend directly on the anomalous magnetic moment of the electron. As a result new wave modes, not present in the absence of spin, appear. The implications of our results are discussed.Comment: 4 pages, two figures, version to appear in Physical Review Letter

Non-adiabatic holonomic quantum computation

We develop a non-adiabatic generalization of holonomic quantum computation in which high-speed universal quantum gates can be realized by using non-Abelian geometric phases. We show how a set of non-adiabatic holonomic one- and two-qubit gates can be implemented by utilizing optical transitions in a generic three-level $\Lambda$ configuration. Our scheme opens up for universal holonomic quantum computation on qubits characterized by short coherence times.Comment: Some changes, journal reference adde

Continuous variable entanglement sharing in non-inertial frames

We study the distribution of entanglement between modes of a free scalar field from the perspective of observers in uniform acceleration. We consider a two-mode squeezed state of the field from an inertial perspective, and analytically study the degradation of entanglement due to the Unruh effect, in the cases of either one or both observers undergoing uniform acceleration. We find that for two observers undergoing finite acceleration, the entanglement vanishes between the lowest frequency modes. The loss of entanglement is precisely explained as a redistribution of the inertial entanglement into multipartite quantum correlations among accessible and unaccessible modes from a non-inertial perspective. We show that classical correlations are also lost from the perspective of two accelerated observers but conserved if one of the observers remains inertial.Comment: 19 pages, 13 EPS figures (most low-res due to oversize); terminology revise

Qualitative perspectives on how Manchester United Football Club developed and sustained serial winning

Talent development in sport is well represented in scientific literature. Yet, the drive to protect ‘trade secrets’ often means that access to these high performing groups is rare, especially as these high level performances are being delivered. This leaves the details of high-end working practices absent from current academic commentary. As a result, clubs interested in developing excellent practice are left to build on personal initiative and insight and/or custom-and-practice, which is unlikely to yield successful outcomes. To address this shortfall the current study reports on prolonged engagement with a single high performing club, considering how their practice corresponds with existing sport talent development models. The paper ends by proposing an evidence-based, football-specific model for talent development, maintained high level performance and serial winning. This model emphasises four dominant features: culture, behavioral characteristics, practice engagement and the managing and guiding of performance ‘potential’. The study provides insights into the visceral reality of daily experiences across the life course of professional soccer, while advancing the evidence-base for understanding how Manchester United achieved their serial success