Elastic, Viscous, and Mass Load Effects on Poststroke Muscle Recruitment and Co-contraction During Reaching: A Pilot Study

Background: Resistive exercise after stroke can improve strength (force-generating capacity) without increasing spasticity (velocity-dependent hypertonicity). However, the effect of resistive load type on muscle activation and co-contraction after stroke is not clear. Objective: The purpose of this study was to determine the effect of load type (elastic, viscous, or mass) on muscle activation and co-contraction during resisted forward reaching in the paretic and nonparetic arms after stroke. Design: This investigation was a single-session, mixed repeated-measures pilot study. Methods: Twenty participants (10 with hemiplegia and 10 without neurologic involvement) reached forward with each arm against equivalent elastic, viscous, and mass loads. Normalized shoulder and elbow electromyography impulses were analyzed to determine agonist muscle recruitment and agonist-antagonist muscle co-contraction. Results: Muscle activation and co-contraction levels were significantly higher on virtually all outcome measures for the paretic and nonparetic arms of the participants with stroke than for the matched control participants. Only the nonparetic shoulder responded to load type with similar activation levels but variable co-contraction responses relative to those of the control shoulder. Elastic and viscous loads were associated with strong activation; mass and viscous loads were associated with minimal co-contraction. Limitations: A reasonable, but limited, range of loads was available. Conclusions: Motor control deficits were evident in both the paretic and the nonparetic arms after stroke when forward reaching was resisted with viscous, elastic, or mass loads. The paretic arm responded with higher muscle activation and co-contraction levels across all load conditions than the matched control arm. Smaller increases in muscle activation and co-contraction levels that varied with load type were observed in the nonparetic arm. On the basis of the response of the nonparetic arm, this study provides preliminary evidence suggesting that viscous loads elicited strong muscle activation with minimal co-contraction. Further intervention studies are needed to determine whether viscous loads are preferable for poststroke resistive exercise programs

Coplanar constant mean curvature surfaces

We consider constant mean curvature surfaces of finite topology, properly embedded in three-space in the sense of Alexandrov. Such surfaces with three ends and genus zero were constructed and completely classified by the authors in arXiv:math.DG/0102183. Here we extend the arguments to the case of an arbitrary number of ends, under the assumption that the asymptotic axes of the ends lie in a common plane: we construct and classify the entire family of these genus-zero coplanar constant mean curvature surfaces.Comment: 35 pages, 10 figures; minor revisions including one new figure; to appear in Comm. Anal. Geo

Triunduloids: Embedded constant mean curvature surfaces with three ends and genus zero

In 1841, Delaunay constructed the embedded surfaces of revolution with constant mean curvature (CMC); these unduloids have genus zero and are now known to be the only embedded CMC surfaces with two ends and finite genus. Here, we construct the complete family of embedded CMC surfaces with three ends and genus zero; they are classified using their asymptotic necksizes. We work in a class slightly more general than embedded surfaces, namely immersed surfaces which bound an immersed three-manifold, as introduced by Alexandrov.Comment: LaTeX, 22 pages, 2 figures (8 ps files); full version of our announcement math.DG/9903101; final version (minor revisions) to appear in Crelle's J. reine angew. Mat

Constant mean curvature surfaces with three ends

We announce the classification of complete, almost embedded surfaces of constant mean curvature, with three ends and genus zero: they are classified by triples of points on the sphere whose distances are the asymptotic necksizes of the three ends.Comment: LaTex, 4 pages, 1 postscript figur

Aircraft noise synthesis system: Version 4 user instructions

A modified version of the Aircraft Noise Synthesis System with improved directivity and tonal content modeling has been developed. The synthesis system is used to provide test stimuli for studies of community annoyance to aircraft flyover noise. The computer-based system generates realistic, time-varying audio simulations of aircraft flyover noise at a specified observer location on the ground. The synthesis takes into account the time-varying aircraft position relative to the observer; specified reference spectra consisting of broadband, narrowband, and pure tone components; directivity patterns; Doppler shift; atmospheric effects; and ground effects. These parameters can be specified and controlled in such a way as to generate stimuli in which certain noise characteristics such as duration or tonal content are independently varied while the remaining characteristics such as broadband content are held constant. The modified version of the system provides improved modeling of noise directivity patterns and an increased number of pure tone components. User instructions for the modified version of the synthesis system are provided

It\u27s What\u27s For Lunch: Nectarines, Mushrooms, and Beef - The First Amendment and Compelled Commercial Speech

JAMES WEINSTEIN: Time for dessert, intellectual dessert. It\u27s my great pleasure to introduce and moderate a discussion between two of the nation\u27s most distinguished law professors: Kathleen Sullivan and Robert Post. Any introduction that would do justice to their accomplishments would take up far too much of the short time allotted. So, by way of a very summary and incomplete introduction, Kathleen Sullivan is the Stanley Morrison Professor of Law at Stanford Law School where she served as dean from 1999 to 2004. She is the author of numerous works on various aspects of constitutional law, including, with the late Gerald Gunther, co-author of the leading constitutional case book. Robert Post is the David Boies Professor of Law at Yale Law School and also the author of numerous works on constitutional law, including Constitutional Domains, an extremely influential book on free speech. Despite their wide-ranging interests and accomplishments in other areas of constitutional law, I think it\u27s fair to say that they both have written most extensively on and have a special interest in free speech. Both have written important articles on commercial speech, including, as it turns out, in The Supreme Court Review. And, Robert Post\u27s recent article in that publication is on the subject of today\u27s presentation, compelled commercial speech

Notes

Notes by Robert E. Sullivan, Frederick N. Hoover, Robert Lowell Miller, Robert M. Million, F. Gerard Feeney, and James D. Sullivan

Dedication in Memory of William Dewey Rollison

William Dewey Rollison, Professor of Law Emeritus: University of Notre Dame 1897-197