Holder exponent spectra for human gait

The stride interval time series in normal human gait is not strictly constant, but fluctuates from step to step in a complex manner. More precisely, it has been shown that the control process for human gait is a fractal random phenomenon, that is, one with a long-term memory. Herein we study the Holder exponent spectra for the slow, normal and fast gaits of 10 young healthy men in both free and metronomically triggered conditions and establish that the stride interval time series is more complex than a monofractal phenomenon. A slightly multifractal and non-stationary time series under the three different gait conditions emerges.Comment: 23 pages, 12 figures, 9 Table

A history of biographical research in the United Kingdom

Biograpahical researchers in the United Kingdom have been influenced by symbolic interactionism, feminism, oral history, critical sociology, psychoanalysis and what we term an auto/biographical imagination. The latter involves reflexively situating the researcher and her influence, via power, unconscious processes and writing, into the text and by acknowledging the co-construction of stories. The focus of much research has been on marginalised peoples, as part of a democratising project to bring more diverse voices and stories into the historical or contemporary social record. It is important to avoid too rigid a distinction between mainland Europe and developments in Britain. Collaboration and dialogue have been extensive, across various research networks, including in the European Society for Research in the Education of Adults (ESREA)

On Holomorphic Effective Actions of Hypermultiplets Coupled to External Gauge Superfields

We study the structure of holomorphic effective action for hypermultiplet models interacting with background super Yang-Mills fields. A general form of holomorphic effective action is found for hypermultiplet belonging to arbitrary representation of any semisimple compact Lie group spontaneously broken to its maximal abelian subgroup. The applications of obtained results to hypermultiplets in fundamental and adjoint representations of the SU(n), SO(n), Sp(n) groups are considered.Comment: 8 pages, no figure

Non-Poisson dichotomous noise: higher-order correlation functions and aging

We study a two-state symmetric noise, with a given waiting time distribution $\psi (\tau)$, and focus our attention on the connection between the four-time and the two-time correlation functions. The transition of $\psi (\tau)$ from the exponential to the non-exponential condition yields the breakdown of the usual factorization condition of high-order correlation functions, as well as the birth of aging effects. We discuss the subtle connections between these two properties, and establish the condition that the Liouville-like approach has to satisfy in order to produce a correct description of the resulting diffusion process

Non-Poisson dichotomous noise: higher-order correlation functions and aging

We study a two-state symmetric noise, with a given waiting time distribution $\psi (\tau)$, and focus our attention on the connection between the four-time and the two-time correlation functions. The transition of $\psi (\tau)$ from the exponential to the non-exponential condition yields the breakdown of the usual factorization condition of high-order correlation functions, as well as the birth of aging effects. We discuss the subtle connections between these two properties, and establish the condition that the Liouville-like approach has to satisfy in order to produce a correct description of the resulting diffusion process

Actively Tuned and Spatially Trapped Polaritons

We report active tuning of the polariton resonance of quantum well excitons in a semiconductor microcavity using applied stress. Starting with the quantum well exciton energy higher than the cavity photon mode, we use stress to reduce the exciton energy and bring it into resonance with the photon mode. At the point of zero detuning, line narrowing and strong increase of the photoluminescence are seen. By the same means, we create an in-plane harmonic potential for the polaritons, which allows trapping, potentially making Bose-Einstein condensation of polaritons analogous to trapped atoms possible. We demonstrate drift of the polaritons into this trap.Comment: 10 pages, 5 figure

Galaxy Orientations in the Coma Cluster

We have examined the orientations of early-type galaxies in the Coma cluster to see whether the well-established tendency for brightest cluster galaxies to share the same major axis orientation as their host cluster also extends to the rest of the galaxy population. We find no evidence of any preferential orientations of galaxies within Coma or its surroundings. The implications of this result for theories of the formation of clusters and galaxies (particularly the first-ranked members) are discussed.Comment: Accepted for publication in the Astrophysical Journal Letters. 4 pages, 4 figure

Metastable Resistance Anisotropy Orientation of Two-Dimensional Electrons in High Landau Levels

In half-filled high Landau levels, two-dimensional electron systems possess collective phases which exhibit a strongly anisotropic resistivity tensor. A weak, but as yet unknown, rotational symmetry-breaking potential native to the host semiconductor structure is necessary to orient these phases in macroscopic samples. Making use of the known external symmetry-breaking effect of an in-plane magnetic field, we find that the native potential can have two orthogonal local minima. It is possible to initialize the system in the higher minimum and then observe its relaxation toward equilibrium.Comment: 5 pages, 3 figures. Figure references corrected. Version accepted for publication in Physical Review Letter

On the relation between nuclear and nucleon Structure Functions and their moments

Calculations of nuclear Structure Functions (SF) F_k^A(x,Q^2) routinely exploit a generalized convolution, involving the SF for nucleons F_k^N and the linking SF f^{PN,A} of a fictitious nucleus, composed of point-particles, with the latter usually expressed in terms of hadronic degrees of freedom. For finite Q^2 the approach seemed to be lacking a solid justification and the same is the case for recently proposed, effective nuclear parton distribution functions (pdf), which exactly reproduce the above-mentioned hadronically computed F_k^A. Many years ago Jaffe and West proved the above convolution in the Plane Wave Impulse Approximation (PWIA) for the nuclear components in the convolution. In the present note we extend the above proof to include classes of nuclear Final State Interactions (FSI). One and the same function appears to relate parton distribution functions (pdf) in nuclei and nucleons, and SF for nuclear targets and for nucleons. That relation is the previously conjectured one,with an entirely different interpretation of f^{PN,A}. We conclude with an extensive analysis of moments of nuclear SF based on the generalized convolution. Characteristics of those moments are shown to be quite similar to the same for a nucleon. We conclude that the above evidences asymptotic freedom of a nucleon in a medium and not of a composite nucleus.Comment: 18 pages, 9 figure