539 research outputs found

    Study of an auroral zone rocket experiment Final report

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    Measurement of flux and energy spectra of protons, energetic particles, hydrogen atoms, and electrons in auroral zone by Nike-Tomahawk sounding rocke

    Phenomenology of Sterile Neutrinos

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    The indications in favor of short-baseline neutrino oscillations, which require the existence of one or more sterile neutrinos, are reviewed. In the framework of 3+1 neutrino mixing, which is the simplest extension of the standard three-neutrino mixing which can partially explain the data, there is a strong tension in the interpretation of the data, mainly due to an incompatibility of the results of appearance and disappearance experiments. In the framework of 3+2 neutrino mixing, CP violation in short-baseline experiments can explain the difference between MiniBooNE neutrino and antineutrino data, but the tension between the data of appearance and disappearance experiments persists because the short-baseline disappearance of electron antineutrinos and muon neutrinos compatible with the LSND and MiniBooNE antineutrino appearance signal has not been observed.Comment: 8 pages. Invited paper to NUFACT 11, XIIIth International Workshop on Neutrino Factories, Super beams and Beta beams, 1-6 August 2011, CERN and University of Geneva (Submitted to IOP conference series

    A Comparison of Three Different Warm-Ups on 800-Meter Running Performance in Elite Division I Track Athletes – A Pilot Study

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    International Journal of Exercise Science 14(6): 1400-1407, 2021. Track and Field athletes perform different types of warm-ups at varying levels of volume and/or intensity prior to competition. Theoretically, this prepares sport specific muscles for activity by increasing muscle temperature, thus mitigating the chance for injury. There is a paucity of information regarding the optimum level for warm-ups regarding maximizing performance in middle distance events. The aim of this study was to examine the effects of three different warm-ups on 800-meter performance. Thirteen Division I student-athletes (seven males and six females) from the Southeastern Conference (SEC) who were middle distance runners participated in this study. We utilized a randomized, cross-over study design to test low, medium, and high-volume warm-up protocols on 800-meter performance. Trials were conducted over a span of three weeks on a SEC University outdoor track. We used a 2 (Sex) x 3 (Warm-Up Protocol) mixed-factor ANOVA, and our results show a main effect of warm-up volume that is not moderated by sex. Post-hoc tests reveal a high-volume warm-up yields superior results for the 800-meter run in comparison to a medium volume warm-up, which provides better results than a low-volume warm-up. These findings may be of value in providing information in program design for coaches on the most effective warm-up protocols for 800-meter runners. Identifying the best warm-up protocol to prime an 800-meter runner for peak performance may not only assist in preventing injury, but enhance performance thus leading to an increased of achievement, and confidence in personal ability

    A phase Ib/II study of cabozantinib (XL184) with or without erlotinib in patients with non-small cell lung cancer.

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    PurposeCabozantinib is a multi-kinase inhibitor that targets MET, AXL, and VEGFR2, and may synergize with EGFR inhibition in NSCLC. Cabozantinib was assessed alone or in combination with erlotinib in patients with progressive NSCLC and EGFR mutations who had previously received erlotinib.MethodsThis was a phase Ib/II study (NCT00596648). The primary objectives of phase I were to assess the safety, pharmacokinetics, and pharmacodynamics and to determine maximum tolerated dose (MTD) of cabozantinib plus erlotinib in patients who failed prior erlotinib treatment. In phase II, patients with prior response or stable disease with erlotinib who progressed were randomized to single-agent cabozantinib 100 mg qd vs cabozantinib 100 mg qd and erlotinib 50 mg qd (phase I MTD), with a primary objective of estimating objective response rate (ORR).ResultsSixty-four patients were treated in phase I. Doses of 100 mg cabozantinib plus 50 mg erlotinib, or 40 mg cabozantinib plus 150 mg erlotinib were determined to be MTDs. Diarrhea was the most frequent dose-limiting toxicity and the most frequent AE (87.5% of patients). The ORR for phase I was 8.2% (90% CI 3.3-16.5). In phase II, one patient in the cabozantinib arm (N = 15) experienced a partial response, for an ORR of 6.7% (90% CI 0.3-27.9), with no responses for cabozantinib plus erlotinib (N = 13). There was no evidence that co-administration of cabozantinib markedly altered erlotinib pharmacokinetics or vice versa.ConclusionsDespite responses with cabozantinib/erlotinib in phase I, there were no responses in the combination arm of phase II in patients with acquired resistance to erlotinib. Cabozantinib did not appear to re-sensitize these patients to erlotinib

    An exact analytical solution for generalized growth models driven by a Markovian dichotomic noise

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    Logistic growth models are recurrent in biology, epidemiology, market models, and neural and social networks. They find important applications in many other fields including laser modelling. In numerous realistic cases the growth rate undergoes stochastic fluctuations and we consider a growth model with a stochastic growth rate modelled via an asymmetric Markovian dichotomic noise. We find an exact analytical solution for the probability distribution providing a powerful tool with applications ranging from biology to astrophysics and laser physics

    Linear systems with adiabatic fluctuations

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    We consider a dynamical system subjected to weak but adiabatically slow fluctuations of external origin. Based on the ``adiabatic following'' approximation we carry out an expansion in \alpha/|\mu|, where \alpha is the strength of fluctuations and 1/|\mu| refers to the time scale of evolution of the unperturbed system to obtain a linear differential equation for the average solution. The theory is applied to the problems of a damped harmonic oscillator and diffusion in a turbulent fluid. The result is the realization of `renormalized' diffusion constant or damping constant for the respective problems. The applicability of the method has been critically analyzed.Comment: Plain Latex, no figure, 21 page

    Random paths and current fluctuations in nonequilibrium statistical mechanics

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    An overview is given of recent advances in nonequilibrium statistical mechanics about the statistics of random paths and current fluctuations. Although statistics is carried out in space for equilibrium statistical mechanics, statistics is considered in time or spacetime for nonequilibrium systems. In this approach, relationships have been established between nonequilibrium properties such as the transport coefficients, the thermodynamic entropy production, or the affinities, and quantities characterizing the microscopic Hamiltonian dynamics and the chaos or fluctuations it may generate. This overview presents results for classical systems in the escape-rate formalism, stochastic processes, and open quantum systems

    Characterization of a periodically driven chaotic dynamical system

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    We discuss how to characterize the behavior of a chaotic dynamical system depending on a parameter that varies periodically in time. In particular, we study the predictability time, the correlations and the mean responses, by defining a local--in--time version of these quantities. In systems where the time scale related to the time periodic variation of the parameter is much larger than the ``internal'' time scale, one has that the local quantities strongly depend on the phase of the cycle. In this case, the standard global quantities can give misleading information.Comment: 15 pages, Revtex 2.0, 8 figures, included. All files packed with uufile

    Measured quantum probability distribution functions for Brownian motion

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    The quantum analog of the joint probability distributions describing a classical stochastic process is introduced. A prescription is given for constructing the quantum distribution associated with a sequence of measurements. For the case of quantum Brownian motion this prescription is illustrated with a number of explicit examples. In particular it is shown how the prescription can be extended in the form of a general formula for the Wigner function of a Brownian particle entangled with a heat bath.Comment: Phys. Rev. A, in pres

    The influence of charge detection on counting statistics

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    We consider the counting statistics of electron transport through a double quantum dot with special emphasis on the dephasing induced by a nearby charge detector. The double dot is embedded in a dissipative enviroment, and the presence of electrons on the double dot is detected with a nearby quantum point contact. Charge transport through the double dot is governed by a non-Markovian generalized master equation. We describe how the cumulants of the current can be obtained for such problems, and investigate the difference between the dephasing mechanisms induced by the quantum point contact and the coupling to the external heat bath. Finally, we consider various open questions of relevance to future research.Comment: 15 pages, 2 figures, Contribution to 5-th International Conference on Unsolved Problems on Noise, Lyon, France, June 2-6, 200
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