465 research outputs found

    Dichotic Auditory Training in 6 to 15 year olds

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    The purpose of this study was to determine if participants with normal auditory processing skills would improve after receiving the Dichotic Auditory Training (DAT) when compared to a group of normal participants who only received pre- and post-testing. Twenty participants, age 6:0 to 15:11 years, participated in this study. A standard audiological evaluation was completed for each participant. Pretest and posttest were completed that included (1) DAT testing, (2) SCAN-C/A, (3) Staggered Spondaic Word test, and (4) Dichotic Digits (Single/Double). The results were analyzed for statistically significant differences between pre- and post-testing results and between groups. Any significant results were thought to be the evidence of the plastic changes desired. It was found that statistically significant differences existed between the two groups for 4 of the 22 testing conditions. Also, when comparing pre- to post-test results, 7 of the 22 conditions were found statistically significant

    Improving Trip- and Slip-Resisting Skills in Older People: Perturbation Dose Matters

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    Aging negatively affects balance recovery responses after trips and slips. We hypothesize that older people can benefit from brief treadmill-based trip and slip perturbation exposure despite reduced muscular capacities, but with neuropathology, their responsiveness to these perturbations will be decreased. Thus, to facilitate long-term benefits and their generalizability to everyday life, one needs to consider the individual threshold for perturbation dose. This is a non-final version of an article published in final form in Exercise and Sport Sciences Review

    Ion and polymer dynamics in polymer electrolytes PPO-LiClO4: II. 2H and 7Li NMR stimulated-echo experiment

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    We use 2H NMR stimulated-echo spectroscopy to measure two-time correlation functions characterizing the polymer segmental motion in polymer electrolytes PPO-LiClO4 near the glass transition temperature Tg. To investigate effects of the salt on the polymer dynamics, we compare results for different ether oxygen to lithium ratios, namely, 6:1, 15:1, 30:1 and infinity. For all compositions, we find nonexponential correlation functions, which can be described by a Kohlrausch function. The mean correlation times show quantitatively that an increase of the salt concentration results in a strong slowing down of the segmental motion. Consistently, for the high 6:1 salt concentration, a high apparent activation energy E_a=4.1eV characterizes the temperature dependence of the mean correlation times at Tg < T< 1.1T_g, while smaller values E_a=2.5eV are observed for moderate salt contents. The correlation functions are most nonexponential for 15:1 PPO-LiClO4, whereas the stretching is reduced for higher and lower salt concentrations. A similar dependence of the correlation functions on the evolution time in the presence and in the absence of ions indicates that addition of salt hardly affects the reorientational mechanism. For all compositions, mean jump angles of about 15 degree characterize the segmental reorientation. In addition, comparison of results from 2H and 7Li NMR stimulated-echo experiments suggests a coupling of ion and polymer dynamics in 15:1 PPO-LiClO4.Comment: 14 pages, 12 figure

    The Curse of Copying , 7 J. Marshall Rev. Intell. Prop. L. 296 (2008)

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    The concept of “copying” has long been involved with various aspects of intellectual property law, particularly in regard to patents and trademarks. In the absence of legally determined exclusive rights, “copying” is permitted, and is in fact, encouraged. However, because the term “copying” carries an undercurrent of disapproval and unfavorable practices, it is a favorite of patentees looking to portray an accused infringer in the most negative light, especially before a jury. Hence, the curse of “copying.” This article will review the current state of “copying” by addressing the substantive precedent in areas where “copying” has traditionally had a substantive effect—willfulness of any accused infringing conduct and obviousness of the patented invention. With respect to “copying” and willful infringement, this article outlines two important considerations that the precedent is weak upon—“‘copying’ what?” and “‘copying’ when?” Lifting the curse requires care and some courage at trial, in view of a precedential framework that is less than favorable to the accused infringer and the pejorative impact the term “copying” will likely have on the jury and the court. These issues will be discussed and suggestions are advanced throughout as to how one might lift the curse once it is pronounced

    Biomechanical mechanisms of jumping performance in youth elite female soccer players

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    We aimed to determine key biomechanical parameters explaining age-related jumping performance differences in youth elite female soccer players. Multiple biomechanical parameters from countermovement (CMJ) squat (SJ) and drop (DJ) jump testing of elite female soccer players (n?=?60) within the same national training centre were analysed across ages 9-11y, 12-14y and 15-19y. Effects of age group and jump type on jump height were found, with the older jumping higher than the younger groups in all jumps (P

    From caging to Rouse dynamics in polymer melts with intramolecular barriers: a critical test of the Mode Coupling Theory

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    By means of computer simulations and solution of the equations of the Mode Coupling Theory (MCT), we investigate the role of the intramolecular barriers on several dynamic aspects of non-entangled polymers. The investigated dynamic range extends from the caging regime characteristic of glass-formers to the relaxation of the chain Rouse modes. We review our recent work on this question, provide new results and critically discuss the limitations of the theory. Solutions of the MCT for the structural relaxation reproduce qualitative trends of simulations for weak and moderate barriers. However a progressive discrepancy is revealed as the limit of stiff chains is approached. This disagreement does not seem related with dynamic heterogeneities, which indeed are not enhanced by increasing barrier strength. It is not connected either with the breakdown of the convolution approximation for three-point static correlations, which retains its validity for stiff chains. These findings suggest the need of an improvement of the MCT equations for polymer melts. Concerning the relaxation of the chain degrees of freedom, MCT provides a microscopic basis for time scales from chain reorientation down to the caging regime. It rationalizes, from first principles, the observed devations from the Rouse model on increasing the barrier strength. These include anomalous scaling of relaxation times, long-time plateaux, and non-monotonous wavelength dependence of the mode correlators.Comment: 15 pages, 14 figure

    Aspects of topology of condensates and knotted solitons in condensed matter systems

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    The knotted solitons introduced by Faddeev and Niemi is presently a subject of great interest in particle and mathematical physics. In this paper we give a condensed matter interpretation of the recent results of Faddeev and Niemi.Comment: v2: Added a reference to the paper E. Babaev, L.D. Faddeev and A.J. Niemi cond-mat/0106152 where an exact equivalence was shown between the two-condensate Ginzburg-Landau model and a version of Faddeev model. Miscelaneous links related to knotted solitons are available at the author homepage at http://www.teorfys.uu.se/PEOPLE/egor/ . Animations of knotted solitons by Hietarinta and Salo are available at http://users.utu.fi/h/hietarin/knots/c45_p2.mp

    Retention of gait stability improvements over 1.5 years in older adults:effects of perturbation exposure and triceps surae neuromuscular exercise

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    The plantarflexors play a crucial role in recovery from sudden disturbances to gait. The objective of this study was to investigate whether medium (months)- or long(years)-term exercise-induced enhancement of triceps surae (TS) neuromuscular capacities affects older adults' ability to retain improvements in reactive gait stability during perturbed walking acquired from perturbation training sessions. Thirty-four adult women (65 +/- 7 yr) were recruited to a perturbation training group (n = 13) or a group that additionally completed 14 wk of TS neuromuscular exercise (n = 21), 12 of whom continued with the exercise for 1.5 yr. The margin of stability (MoS) was analyzed at touchdown of the perturbed step and the first recovery step following eight separate unexpected trip perturbations during treadmill walking. TS muscle-tendon unit mechanical properties and motor skill performance were assessed with ultrasonography and dynamometry. Two perturbation training sessions (baseline and after 14 wk) caused an improvement in the reactive gait stability to the perturbations (increased MoS) in both groups. The perturbation training group retained the reactive gait stability improvements acquired over 14 wk and over 1.5 yr. with a minor decay over time. Despite the improvements in TS capacities in the additional exercise group. no benefits for the reactive gait stability following perturbations were identified. Therefore, older adults' neuromotor system shows rapid plasticity to repeated unexpected perturbations and an ability to retain these adaptations in reactive gait stability over a long time period, but an additional exercise-related enhancement of TS capacities seems not to further improve these effects. NEW & NOTEWORTHY Older adults' neuromotor system shows rapid plasticity to repeated exposure to unexpected perturbations to gait and an ability to retain the majority of these adaptations in reactive recovery responses over a prolonged time period of 1.5 yr. However, an additional exercise-related enhancement of TS neuromuscular capacities is not necessarily transferred to the recovery behavior during unexpected perturbations to gait in older adults

    Perturbation-based balance training: Principles, mechanisms and implementation in clinical practice

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    Since the mid-2000s, perturbation-based balance training has been gaining interest as an efficient and effective way to prevent falls in older adults. It has been suggested that this task-specific training approach may present a paradigm shift in fall prevention. In this review, we discuss key concepts and common issues and questions regarding perturbation-based balance training. In doing so, we aim to provide a comprehensive synthesis of the current evidence on the mechanisms, feasibility and efficacy of perturbation-based balance training for researchers and practitioners. We address this in two sections: “Principles and Mechanisms” and “Implementation in Practice.” In the first section, definitions, task-specificity, adaptation and retention mechanisms and the dose-response relationship are discussed. In the second section, issues related to safety, anxiety, evidence in clinical populations (e.g., Parkinson's disease, stroke), technology and training devices are discussed. Perturbation-based balance training is a promising approach to fall prevention. However, several fundamental and applied aspects of the approach need to be further investigated before it can be widely implemented in clinical practice
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