Asymptotic behavior of initially "large and smooth" pulses is investigated at two typical stages of their evolution governed by the defocusing nonlinear Schrödinger equation. At first, wave breaking phenomenon is studied in the limit of small dispersion. A solution of the Whitham modulational equations is found for the case of dissipationless shock wave arising after the wave breaking point. Th...

BACKGROUND AND PURPOSE Recent reports have suggested that electrical stimulation trains that take advantage of the catchlike property of skeletal muscle can produce higher forces from skeletal muscle than traditionally used constant-frequency trains. This study investigated the effects of catchlike-inducing trains on human quadriceps femoris muscles while the kneejoint was held at 15 degrees of...

The posterior parietal cortex (PPC) of monkeys and prosimian galagos contains a number of subregions where complex, behaviorally meaningful movements, such as reaching, grasping, and body defense, can be evoked by electrical stimulation with long trains of electrical pulses through microelectrodes. Shorter trains of pulses evoke no or simple movements. One possibility for the difference in effe...

Neuromuscular electrical stimulation (NMES) involves the use of electrical current to facilitate contraction of skeletal muscle. However, little is known concerning the effects of varying stimulation parameters on muscle function in humans. The purpose of this study was to determine the extent to which varying pulse duration and frequency altered torque production and fatigability of human skel...

The clinical efficacy of functional electrical stimulation (FES) is limited by the rapid onset of fatigue. Functional electrical stimulation applications typically stimulate skeletal muscles with constant-frequency trains (CFTs). Our laboratory has identified trains that we call doublet-frequency trains (DFTs) and that produce greater forces than CFTs, but more fatigue during repetitive activat...

dans cet article i' intervalle entre deux trains successifs a ete etudie en fonction de leur vitesses dans deux cas differents. dans ie premier cas ,on suppose que la vitesse des deux trains a une valeur constante, et on etudie les variations de l'intervalle minimum en fonction de la vitesse on determine la vitesse optimale et on etudie les variations de l'intervalle minimum en f...

Short-term synaptic depression is an important component of computation within neural networks, but little is known of its contribution to information processing during synaptically generated spike trains. We analyzed short-term synaptic depression at a synapse between two identified motoneurons innervating the hind leg of the locust: the FETi-FlTi synapse (fast extensor tibiae-flexor tibiae). ...

More than 30,000 hearing-impaired human subjects have learned to use cochlear implants for speech perception and speech discrimination. To understand the basic mechanisms underlying the successful application of contemporary speech processing strategies, it is important to investigate how complex electrical stimuli delivered to the cochlea are processed and represented in the central auditory s...