1,310 research outputs found

    Effects of progressive fatigue and expertise on self-talk content in running: an ambulatory assessment approach

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    Effects of Progressive Fatigue and Expertise on Self-Talk Content in Running: An Ambulatory Assessment Approach Arne Nieuwenhuys (1)*, Laurens J. Veltman (2), Louise M.A. Braakman-Jansen (2), & Paul A. Davis (3) (1) Behavioural Science Institute, Radboud University Nijmegen, The Netherlands (2) Institute for Behavioral Research, Twente University, The Netherlands (3) Department of Sport Development, Northumbria University, United Kingdom Introduction In this study we investigated how progressive fatigue differentially affects self-talk use (nr. of statements) and content (instructional, motivational, positive, negative) in recreational and competitive runners, by using a new ambulatory assessment method called ā€œPsyqRunā€ ā€“ a smartphone application that enables online assessment of psychological states and variables (e.g. self-perceived exertion, self-talk) during exercise. Methods 42 participants (20 recreational runners, 22 competitive runners) performed a strenuous running exercise in which they attempted to reach a maximal distance over eight 2-minute intervals. Self-perceived exertion (RPE) and self-talk were assessed at the end of every interval by using the PsyqRun application. Heart rate was measured continuously with a heart rate monitor. Results RPE scores and heart rate measurement confirmed that fatigue systematically increased as a function of exercise interval. Under high levels of fatigue (i.e., at later intervals) participants generally reported more self-talk statements than under low levels of fatigue (i.e., at earlier intervals). More specifically, with increasing fatigue, participantsā€™ use of positive and motivational self-talk strongly increased at the cost of instructional self-talk, which strongly decreased. Finally, a marginally significant effect of expertise (p = .058) indicated that competitive runners used more instructional self-talk than recreational runners ā€“ also under high levels of fatigue. Discussion Using modern smartphone technology, the current study was the first to provide an online assessment of fatigue and self-talk in running. Findings indicated that participants actively focused on their running technique at the start of the exercise (e.g., ā€œkeep running smoothlyā€) but shifted to self-motivation and perseverance during later intervals, when they became more fatigued (e.g., ā€œjust one more interval!ā€). These results are consistent with research on fatigue and attentional focus and indicate that ā€“ with increasing fatigue ā€“ runnersā€™ thoughts and attention are automatically drawn inwards towards the monitoring of internal states and processes. Finally, it is suggested that by using more instructional self-talk, competitive runners may be able to maintain a more efficient running technique, also under high levels of fatigue. Further development of the PsyqRun application should clarify this matter, by relating the assessment of self-talk to objective measures of running technique and performance

    Identification performance of evidential value estimation for ridge-based biometrics

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    Law enforcement agencies around the world use ridge-based biometrics, especially fingerprints, to fight crime. Fingermarks that are left at a crime scene and identified as potentially having evidential value (EV) in a court of law are recorded for further forensic analysis. Here, we test our evidential value algorithm (EVA) which uses image features trained on forensic expert decisions for 1428 fingermarks to produce an EV score for an image. First, we study the relationship between whether a fingermark is assessed as having EV, either by a human expert or by EVA, and its correct and confident identification by an automatic identification system. In particular, how often does an automatic system achieve identification when the mark is assessed as not having evidential value? We show that when the marks are captured by a mobile phone, correct and confident automatic matching occurs for 257 of the 1428. Of these, 236 were marked as having sufficient EV by experts and 242 by EVA thresholded on equal error rate. Second, we test four relatively challenging ridge-based biometric databases and show that EVA can be successfully applied to give an EV score to all images. Using EV score as an image quality value, we show that in all databases, thresholding on EV improves performance in closed set identification. Our results suggest an EVA application that filters fingermarks meeting a minimum EV score could aid forensic experts at the point of collection, or by flagging difficult latents objectively, or by pre-filtering specimens before submission to an AFIS

    Thermodynamic properties of thin films of superfluid 3He-A

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    The pairing correlations in superfluid He-3 are strongly modified by quasiparticle scattering off a surface or an interface. We present theoretical results and predictions for the order parameter, the quasiparticle excitation spectrum and the free energy for thin films of superfluid He-3. Both specular and diffuse scattering by a substrate are considered, while the free surface is assumed to be a perfectly reflecting specular boundary. The results are based on self-consistent calculations of the order parameter and quasiparticle excitation spectrum at zero pressure. We obtain new results for the phase diagram, free energy, entropy and specific heat of thin films of superfluid He-3.Comment: Replaced with an updated versio

    Cryptic loxP sites in mammalian genomes: genome-wide distribution and relevance for the efficiency of BAC/PAC recombineering techniques

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    Cre is widely used for DNA tailoring and, in combination with recombineering techniques, to modify BAC/PAC sequences for generating transgenic animals. However, mammalian genomes contain recombinase recognition sites (cryptic loxP sites) that can promote illegitimate DNA recombination and damage when cells express the Cre recombinase gene. We have created a new bioinformatic tool, FuzznucComparator, which searches for cryptic loxP sites and we have applied it to the analysis of the whole mouse genome. We found that cryptic loxP sites occur frequently and are homogeneously distributed in the genome. Given the mammalian nature of BAC/PAC genomic inserts, we hypothesised that the presence of cryptic loxP sites may affect the ability to grow and modify BAC and PAC clones in E. coli expressing Cre recombinase. We have observed a defect in bacterial growth when some BACs and PACs were transformed into EL350, a DH10B-derived bacterial strain that expresses Cre recombinase under the control of an arabinose-inducible promoter. In this study, we have demonstrated that Cre recombinase expression is leaky in un-induced EL350 cells and that some BAC/PAC sequences contain cryptic loxP sites, which are active and mediate the introduction of single-strand nicks in BAC/PAC genomic inserts

    Towards a Stringy Resolution of the Cosmological Singularity

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    We study cosmological solutions to the low-energy effective action of heterotic string theory including possible leading order Ī±ā€²\alpha' corrections and a potential for the dilaton. We consider the possibility that including such stringy corrections can resolve the initial cosmological singularity. Since the exact form of these corrections is not known the higher-derivative terms are constructed so that they vanish when the metric is de Sitter spacetime. The constructed terms are compatible with known restrictions from scattering amplitude and string worldsheet beta-function calculations. Analytic and numerical techniques are used to construct a singularity-free cosmological solution. At late times and low-curvatures the metric is asymptotically Minkowski and the dilaton is frozen. In the high-curvature regime the universe enters a de Sitter phase.Comment: 6 pages, 2 Figures; minor revisions; references added; REVTeX 4; version to appear in Phys. Rev.

    Superfluid toroidal currents in atomic condensates

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    The dynamics of toroidal condensates in the presence of condensate flow and dipole perturbation have been investigated. The Bogoliubov spectrum of condensate is calculated for an oblate torus using a discrete-variable representation and a spectral method to high accuracy. The transition from spheroidal to toroidal geometry of the trap displaces the energy levels into narrow bands. The lowest-order acoustic modes are quantized with the dispersion relation Ļ‰āˆ¼āˆ£māˆ£Ļ‰s\omega \sim |m| \omega_s with m=0,Ā±1,Ā±2,...m=0,\pm 1,\pm 2, .... A condensate with toroidal current Īŗ\kappa splits the āˆ£māˆ£|m| co-rotating and counter-rotating pair by the amount: Ī”Eā‰ˆ2āˆ£māˆ£ā„2Īŗ<rāˆ’2>\Delta E \approx 2 |m|\hbar^2 \kappa < r^{-2}>. Radial dipole excitations are the lowest energy dissipation modes. For highly occupied condensates the nonlinearity creates an asymmetric mix of dipole circulation and nonlinear shifts in the spectrum of excitations so that the center of mass circulates around the axis of symmetry of the trap. We outline an experimental method to study these excitations.Comment: 8 pages, 8 figure

    Disordered eating behaviour is associated with blunted cortisol and cardiovascular reactions to acute psychological stress

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    Research suggests a potential dysregulation of the stress response in individuals with bulimia nervosa. This study measured both cardiovascular and cortisol reactions to a standardised laboratory stress task in individuals identified as showing disordered eating behaviour to determine whether dysregulation of the stress response is characteristic of the two branches of the stress response system. Female students (N = 455) were screened using two validated eating disorder questionnaires. Twelve women with disordered eating, including self-induced vomiting, and 12 healthy controls were selected for laboratory stress testing. Salivary cortisol and cardiovascular activity, via Doppler imaging and semi-automatic blood pressure monitoring, were measured at resting baseline and during and after exposure to a 10-min mental arithmetic stress task. Compared to controls the disordered eating group showed blunted cortisol, cardiac output, heart rate, and stroke volume reactions to the acute stress, as well as an attenuated vasodilatory reaction. These effects could not be accounted for in terms of group differences in stress task performance, subjective task impact/engagement, age, BMI, neuroticism, cardiorespiratory fitness, or co-morbid exercise dependence. Our findings suggest that disordered eating is characterised by a dysregulation of the autonomic stress-response system. As such, they add further weight to the general contention that blunted stress reactivity is characteristic of a number of maladaptive behaviours and states

    Modelling the cost-effectiveness of a newborn hearing screening programme:Usability and pitfalls

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    Objective: The EUSCREEN project concerns the study of European vision and hearing screening programmes. Part of the project was the development of a cost-effectiveness model to analyse such programmes. We describe the development and usability of an online tool to enable stakeholders to design, analyse or modify a newborn hearing screening (NHS) programme. Design: Data from literature, from existing NHS programmes, and observations by users were used to develop and refine the tool. Required inputs include prevalence of the hearing impairment, test sequence and its timing, attendance, sensitivity, and specificity of each screening step. Outputs include the number of cases detected and the costs of screening and diagnostics. Study sample: Eleven NHS programmes with reliable data. Results: Three analyses are presented, exploring the effect of low attendance, number of screening steps, testing in the maternity ward, or screening at a later age, on the benefits and costs of the programme. Knowledge of the epidemiology of a staged screening programme is crucial when using the tool. Conclusions: This study presents a tool intended to aid stakeholders to design a new or analyse an existing hearing screening programme in terms of benefits and costs.</p

    Persistent currents in a circular array of Bose-Einstein condensates

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    A ring-shaped array of Bose-Einstein condensed atomic gases can display circular currents if the relative phase of neighboring condensates becomes locked to certain values. It is shown that, irrespective of the mechanism responsible for generating these states, only a restricted set of currents are stable, depending on the number of condensates, on the interaction and tunneling energies, and on the total number of particles. Different instabilities due to quasiparticle excitations are characterized and possible experimental setups for testing the stability prediction are also discussed.Comment: 7 pages, REVTex

    Loop-Generated Bounds on Changes to the Graviton Dispersion Relation

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    We identify the effective theory appropriate to the propagation of massless bulk fields in brane-world scenarios, to show that the dominant low-energy effect of asymmetric warping in the bulk is to modify the dispersion relation of the effective 4-dimensional modes. We show how such changes to the graviton dispersion relation may be bounded through the effects they imply, through loops, for the propagation of standard model particles. We compute these bounds and show that they provide, in some cases, the strongest constraints on nonstandard gravitational dispersions. The bounds obtained in this way are the strongest for the fewest extra dimensions and when the extra-dimensional Planck mass is the smallest. Although the best bounds come for warped 5-D scenarios, for which the 5D Planck Mass is O(TeV), even in 4 dimensions the graviton loop can lead to a bound on the graviton speed which is comparable with other constraints.Comment: 18 pages, LaTeX, 4 figures, uses revte
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