The insufficient temporal resolution of imaging devices has made the analysis of very fast movements, such as those required to measure active muscle-tendon unit stiffness, difficult. Thus the relative contributions of tendon, aponeurosis, and fascicle to muscle-tendon unit compliance remain to be determined. The present study analyzed the dynamic interactions of fascicle, tendon, and aponeuros...

We studied whether the oxygen cost of mechanical energy is time-invariant in the excised, cross-circulated canine heart. The total mechanical energy generated by ventricular contraction can be quantified by the total pressure-volume area (PVA) according to the time-varying eiastance model. In this model, mechanical energy generated until a specified time (t) during systole can be quantified by ...

We studied whether the oxygen cost of mechanical energy is time-invariant in the excised, cross-circulated canine heart. The total mechanical energy generated by ventricular contraction can be quantified by the total pressure-volume area (PVA) according to the time-varying elastance model. In this model, mechanical energy generated until a specified time (t) during systole can be quantified by ...

Series elastic element stiffness was studied during isometric muscle contraction in cylindrical segments of dog common carotid artery. These vessel segments were mounted in vitro and restored to in situ length. Vessel diameter was constantly monitored with a linear displacement transducer. The arteries were subjected to isometric contraction by adding norepinephrine to the bath and elevating th...

In this Quick Guide, Brierley provides a brief overview of a pervasive aspect of aquatic ecosystems, the daily movement of organisms up and down the water column.

BACKGROUND Catch-up saccades during passive head movements, which compensate for a deficient vestibulo-ocular reflex (VOR), are a well-known phenomenon. These quick eye movements are directed toward the target in the opposite direction of the head movement. Recently, quick eye movements in the direction of the head movement (covert anti-compensatory quick eye movements, CAQEM) were observed in ...

To test current hypotheses on the contribution of the basal ganglia (BG) to motor control, we examined the effects of muscimol-induced inactivations in the skeletomotor region of the internal globus pallidus (sGPi) on visually directed reaching. Injections were made in two monkeys trained to perform four out-and-back reaching movements in quick succession toward four randomly selected target lo...

We have studied the effect of duration of stimulation on the dynamic behavior of isolated dog trachealis muscle tonically contracted by alternating current or carbachol. With the muscle contracted quick stretch and quick release maneuvers were performed. The force-length curves during the quick maneuvers were similar for both methods of stimulation and regardless of the duration of stimulation....