This study examines the potential for a ventilatory drive, independent of mean PCO2, but depending instead on changes in PCO2 that occur during the respiratory cycle. This responsiveness is referred to here as "dynamic ventilatory sensitivity." The normal, spontaneous, respiratory oscillations in alveolar PCO2 have been modified with inspiratory pulses approximating alveolar PCO2 concentrations...

In the extrusion of polymeric melts at high ow rates, often ow instabilities observed as surface distortions of the extrudate occur. The ow instability 'spurt' in piston-driven ows is accompanied by persistent oscillations in the pressure. In this paper spurt is explained in terms of constitutive instabilities (mechanical failure of the polymeric uid itself), while the no-slip boundary conditio...

OBJECTIVE Cross-transfer effects were investigated during an occupationally embedded task that involved learning a fine motor skill. Cross-transfer is a phenomenon that occurs when an untrained limb receives some of the same benefits in performance from unilateral training that the contralateral limb received. It was hypothesized that cross-transfer would occur after a unilateral training regim...

The four-year oscillations of the number of spawning sockeye salmon (Oncorhynchus nerka) that return to their native stream within the Fraser River basin in Canada are a striking example of population oscillations. The period of the oscillation corresponds to the dominant generation time of these fish. Various-not fully convincing-explanations for these oscillations have been proposed, includin...

The Electromagnetic transients progr am and its variants all use the “trapezoidal rule” numerical integration method. The trapezoidal rule is a second order numerical integration technique that is simple to implement. However, it is also susceptible to numerical oscillations when differentiat ing step changes in voltage and current. The program user should be aware of the potential for these os...

We consider theoretically the spontaneous oscillations of an elastic cylinder in a streaming fluid flow. Such oscillations are responsible for stall flutter in e.g. turbine blades and bridges, or Æolian tones when in the acoustic range. The process of vortex separation from the oscillating surface is modelled as a self-excited oscillator. The vortex separation frequency remains synchronized wit...

While odorant-evoked oscillations in the vertebrate olfactory bulb have been studied extensively, information about their possible cognitive role has been missing. Using voltage-sensitive dye imaging, we show that repeated odorant presentations with interstimulus intervals of 2-12 s had dramatic and diverse effects on the three oscillations that occur in the turtle olfactory bulb. Two of the os...

The voltage oscillations which occur in an ideally current-biased Josephson junction were proposed to make a current standard for metrology. We demonstrate similar oscillations in a more complex Josephson circuit derived from the Cooper pair box: the quantronium. When a constant current I is injected in the gate capacitor of this device, oscillations develop at the frequency f(B)=I/2e, with e t...

The intriguing midair oscillations of a party balloon, which occur once its buoyancy is no longer capable of keeping it against the ceiling, is shown to require a rather sophisticated explanation in terms of variable-mass dynamics. The ubiquity of this phenomenon, the accessibility of its actual observation, and the subtlety of its analytic description provide a good opportunity for an interest...

Reaction temperature plays a major role in product selectivity in the oscillatory mode of the palladium-catalyzed phenylacetylene oxidative carbonylation reaction. At 40 °C, dimethyl (2Z)-2-phenyl-2-butenedioate is the major product whereas at 0 °C the major product is 5,5-dimethoxy-3-phenyl-2(5H)-furanone. The occurrence of oscillations in pH coincides with an increase in the rate of phenylace...