The Impact of Sleep on Mental Toughness: Evidence From Observational and N-of-1 Manipulation Studies in Athletes

This is the author accepted manuscript. The final version is available from American Psychological Association via the DOI in this recordhe purpose of this study was to explore the direction and magnitude of the relationship between sleep and mental toughness and examine the effect of time in bed extension and restriction on mental toughness. Study 1 was an observational study examining the relationship between sleep quality and duration (hours) and mental toughness in 181 participants. Winsorized correlations revealed both longer sleep duration (ρω = .176 [.033, .316], p = .016) and higher quality (ρω = .412 [.270, .541], p ≤ .001) were associated with increased mental toughness. Follow-up regression analyses revealed sleep quality (b = 0.177, [0.117, 0,238], p ≤ .001), but not sleep duration (b = 0.450, [0.3254, 1.22], p = .256), predicted mental toughness score. In Study 2, we utilized a longitudinal N-of-1 influenced methodology with 6 participants to further examine whether manipulated time in bed (i.e., sleep duration) influenced mental toughness. Participants recorded sleep quality, duration, and mental toughness over 5 weekdays during 2 separate 2-week periods of baseline (normal sleeping pattern) followed by manipulated time in bed (counterbalanced 9 hr or 5 hr). Visual analyses (including determination of nonoverlapping data points between baseline and intervention weeks) revealed reduced time in bed negatively impacted the mental toughness of 4 of the participants. Social validation interviews were conducted to further explore participants' perceptions of the sleep manipulation. A cumulative effect of reduced sleep on mental toughness was noted by specific individuals. In addition, participants identified potential buoys of mental toughness in the absence of sleep

An exploratory case study of mental toughness variability and potential influencers over 30 Days

This is the final version. Available from the publisher via the DOI in this record.The purpose of this study was to explore whether mental toughness varies across a 30-day training block and whether such variability is associated with specific antecedents. This exploratory case study research investigated mental toughness variability using the Mental Toughness Index (MTI) with thirteen elite master runners across a series of self-selected training sessions, followed by interviews and follow-up questionnaires, to identify primary influencers of variability. There were significant differences in the MTI scores between baseline (before the training period), and the minimum and the maximum reported score over five self-selected training sessions (p's < 0.004). The proceeding follow-up interviews and questionnaires then provided insights into factors influencing this intra-individual variability. These higher-level themes included foundational wellbeing, specific preparation, and actions utilized in the moment. This study is the first to demonstrate within-person MTI variability across specific training sessions and provides initial insights for both athletes and practitioners into potential influencers of mental toughness

A 3000-mile tour of mental toughness: An autoethnographic exploration of mental toughness intra-individual variability in endurance sport

This is the author accepted manuscript. The final version is available from Routledge via the DOI in this recordMental toughness has garnered considerable attention over the past two decades because of the perception that this psychological construct influences an athlete’s ability to strive, thrive, and survive in sport. However, few researchers have explored the lived experiences of mental toughness within endurance sport. Analysis of lived experiences could help reveal how an athlete demonstrates (or does not demonstrate) mental toughness in real-world settings and provide insights for researchers, coaches and athletes in the future. The current autoethnographic approach offers an alternative perspective to supplement the existing mental toughness literature, and provides the most appropriate format to analyze the within-person mental toughness element at the core of this research study. The study recounts and analyses the personal experience of mental toughness across a trilogy of cycling, triathlon, and running endurance events by a single athlete over a 5-month period. The main findings focus on the variability of perceived mental toughness at different stages of competition and training and identify potential factors driving the notable fluctuation in levels of mental toughness. Factors identified as increasing this within-person mental toughness included anger, love, competition, encouragement and the recognition of a last chance to achieve meaningful goals. These findings are expected to support future research into within-person mental toughness and the practical application across a broader spectrum of settings

From Rotating Atomic Rings to Quantum Hall States

Considerable efforts are currently devoted to the preparation of ultracold neutral atoms in the emblematic strongly correlated quantum Hall regime. The routes followed so far essentially rely on thermodynamics, i.e. imposing the proper Hamiltonian and cooling the system towards its ground state. In rapidly rotating 2D harmonic traps the role of the transverse magnetic field is played by the angular velocity. For particle numbers significantly larger than unity, the required angular momentum is very large and it can be obtained only for spinning frequencies extremely near to the deconfinement limit; consequently, the required control on experimental parameters turns out to be far too stringent. Here we propose to follow instead a dynamic path starting from the gas confined in a rotating ring. The large moment of inertia of the fluid facilitates the access to states with a large angular momentum, corresponding to a giant vortex. The initial ring-shaped trapping potential is then adiabatically transformed into a harmonic confinement, which brings the interacting atomic gas in the desired quantum Hall regime. We provide clear numerical evidence that for a relatively broad range of initial angular frequencies, the giant vortex state is adiabatically connected to the bosonic $\nu=1/2$ Laughlin state, and we discuss the scaling to many particles.Comment: 9 pages, 5 figure

Dynamical Autler-Townes control of a phase qubit

Routers, switches, and repeaters are essential components of modern information-processing systems. Similar devices will be needed in future superconducting quantum computers. In this work we investigate experimentally the time evolution of Autler-Townes splitting in a superconducting phase qubit under the application of a control tone resonantly coupled to the second transition. A three-level model that includes independently determined parameters for relaxation and dephasing gives excellent agreement with the experiment. The results demonstrate that the qubit can be used as a ON/OFF switch with 100 ns operating time-scale for the reflection/transmission of photons coming from an applied probe microwave tone. The ON state is realized when the control tone is sufficiently strong to generate an Autler-Townes doublet, suppressing the absorption of the probe tone photons and resulting in a maximum of transmission.Comment: 8 pages, 8 figure

Exoplanet phase curves: observations and theory

Phase curves are the best technique to probe the three dimensional structure of exoplanets' atmospheres. In this chapter we first review current exoplanets phase curve observations and the particular challenges they face. We then describe the different physical mechanisms shaping the atmospheric phase curves of highly irradiated tidally locked exoplanets. Finally, we discuss the potential for future missions to further advance our understanding of these new worlds.Comment: Fig.5 has been updated. Table 1 and corresponding figures have been updated with new values for WASP-103b and WASP-18b. Contains a table sumarizing phase curve observation

Evidence for a fractional quantum Hall state with anisotropic longitudinal transport

At high magnetic fields, where the Fermi level lies in the N=0 lowest Landau level (LL), a clean two-dimensional electron system (2DES) exhibits numerous incompressible liquid phases which display the fractional quantized Hall effect (FQHE) (Das Sarma and Pinczuk, 1997). These liquid phases do not break rotational symmetry, exhibiting resistivities which are isotropic in the plane. In contrast, at lower fields, when the Fermi level lies in the $N\ge2$ third and several higher LLs, the 2DES displays a distinctly different class of collective states. In particular, near half filling of these high LLs the 2DES exhibits a strongly anisotropic longitudinal resistance at low temperatures (Lilly et al., 1999; Du et al., 1999). These "stripe" phases, which do not exhibit the quantized Hall effect, resemble nematic liquid crystals, possessing broken rotational symmetry and orientational order (Koulakov et al., 1996; Fogler et al., 1996; Moessner and Chalker, 1996; Fradkin and Kivelson, 1999; Fradkin et al, 2010). Here we report a surprising new observation: An electronic configuration in the N=1 second LL whose resistivity tensor simultaneously displays a robust fractionally quantized Hall plateau and a strongly anisotropic longitudinal resistance resembling that of the stripe phases.Comment: Nature Physics, (2011

Coherent quantum state storage and transfer between two phase qubits via a resonant cavity

A network of quantum-mechanical systems showing long lived phase coherence of its quantum states could be used for processing quantum information. As with classical information processing, a quantum processor requires information bits (qubits) that can be independently addressed and read out, long-term memory elements to store arbitrary quantum states, and the ability to transfer quantum information through a coherent communication bus accessible to a large number of qubits. Superconducting qubits made with scalable microfabrication techniques are a promising candidate for the realization of a large scale quantum information processor. Although these systems have successfully passed tests of coherent coupling for up to four qubits, communication of individual quantum states between qubits via a quantum bus has not yet been demonstrated. Here, we perform an experiment demonstrating the ability to coherently transfer quantum states between two superconducting Josephson phase qubits through a rudimentary quantum bus formed by a single, on chip, superconducting transmission line resonant cavity of length 7 mm. After preparing an initial quantum state with the first qubit, this quantum information is transferred and stored as a nonclassical photon state of the resonant cavity, then retrieved at a later time by the second qubit connected to the opposite end of the cavity. Beyond simple communication, these results suggest that a high quality factor superconducting cavity could also function as a long term memory element. The basic architecture presented here is scalable, offering the possibility for the coherent communication between a large number of superconducting qubits.Comment: 17 pages, 4 figures (to appear in Nature

Training Auto-encoder-based Optimizers for Terahertz Image Reconstruction

Terahertz (THz) sensing is a promising imaging technology for a wide variety of different applications. Extracting the interpretable and physically meaningful parameters for such applications, however, requires solving an inverse problem in which a model function determined by these parameters needs to be fitted to the measured data. Since the underlying optimization problem is nonconvex and very costly to solve, we propose learning the prediction of suitable parameters from the measured data directly. More precisely, we develop a model-based autoencoder in which the encoder network predicts suitable parameters and the decoder is fixed to a physically meaningful model function, such that we can train the encoding network in an unsupervised way. We illustrate numerically that the resulting network is more than 140 times faster than classical optimization techniques while making predictions with only slightly higher objective values. Using such predictions as starting points of local optimization techniques allows us to converge to better local minima about twice as fast as optimization without the network-based initialization.Comment: This is a pre-print of a conference paper published in German Conference on Pattern Recognition (GCPR) 201

Sign-reversal of the in-plane resistivity anisotropy in hole-doped iron pnictides

The in-plane anisotropy of the electrical resistivity across the coupled orthorhombic and magnetic transitions of the iron pnictides has been extensively studied in the parent and electron-doped compounds. All these studies universally show that the resistivity $\rho_{a}$ across the long orthorhombic axis $a_{O}$ - along which the spins couple antiferromagnetically below the magnetic transition temperature - is smaller than the resistivity $\rho_{b}$ of the short orthorhombic axis $b_{O}$, i. e. $\rho_{a}<\rho_{b}$. Here we report that in the hole-doped compounds Ba$_{1-x}$K$_{x}$Fe$_{2}$As$_{2}$, as the doping level increases, the resistivity anisotropy initially becomes vanishingly small, and eventually changes sign for sufficiently large doping, i. e. $\rho_{b}<\rho_{a}$. This observation is in agreement with a recent theoretical prediction that considers the anisotropic scattering of electrons by spin-fluctuations in the orthorhombic/nematic state.Comment: This paper has been replaced by the new version offering new explanation of the experimental results first reported her