The impact of two predictor variables (estimated knee extensor fast-twitch fiber percentage, body mass) on performance measures (vertical jump power output, leg press peak angular velocity) were examined. Subjects (25 men, 27 women) performed 5 workouts involving 2 vertical jump, leg press, and 50-repetition isokinetic tests (to estimate knee extensor fast-twitch fiber percentage). Multivariate...

The mechanism of twitch prolongation of hypoxic myocardium after reoxygenation was studied before and after interventions that affect cellular cyclic nucleotide levels, subcellular calcium handling, or oxygen-derived free radical production/survival. Right ventricular ferret papillary muscles were subjected to two 20-minute periods of hypoxia, each followed by 1 hour of reoxygenation. The first...

We examined whether adenosine equally attenuated the stimulatory effects of isoproterenol on arrhythmic activity and twitch shortening of guinea pig isolated ventricular myocytes. Transmembrane voltages and whole cell currents were recorded with patch electrodes, and cell twitch shortening was measured using a video-motion detector. Isoproterenol increased the action potential duration at 50% r...

During neonatal development, there is an increase in myocardial stiffness that coincides with an increase in the contractility of the heart. In vitro assays have shown that substrate stiffness plays a role in regulating the twitch forces produced by immature cardiomyocytes. However, its effect on twitch power is unclear due to difficulties in measuring the twitch velocity of cardiomyocytes. Her...

Single muscle fibers were exposed to solutions made hypertonic (approximately 460 milliosmols/kg water) by addition of either NaCl, glycerol, urea, acetamide, ethylene glycol, or propylene glycol. The changes in either the fiber twitch tension or the volume were measured. In the case of NaCl both fiber volume and twitch tension fall rapidly to 64 and 27% of the respective initial value. These t...

Twitch is a live video streaming platform used for broadcasting video gameplay, ranging from amateur players to eSports tournaments. This platform has gathered a substantial world wide community, reaching more than 1.7 million broadcasters and 100 million visitors every month. Twitch is fundamentally different from “static” content distribution platforms such as YouTube and Netflix, as streams ...

An attempt has been made in the three previous papers (Pennycuick, 1964 a, b, c) to give an account of the time course of the various components of mechanical power output during a single twitch in frog fast muscle fibres. These observations were mainly made on the third of a series of three twitches, at 50 msec, intervals (that is, at intervals considerably shorter than the duration of the com...

We have studied the relationship between post-tetanic twitch (PTT) and single twitch response after administration of vecuronium 0.2 mg kg-1 in 100 patients during neuroleptanaesthesia (NLA) (droperidol and fentanyl) and during anaesthesia with halothane, isoflurane, enflurane or sevoflurane (1 MAC in nitrous oxide and oxygen). Intervals from PTT1 to single twitch, and post-tetanic-count (PTC) ...

Unfused tetanic contractions evoked by trains of stimuli at variable interpulse 32 intervals (IPIs) were recorded for 10 fast fatigable (FF), 10 fast resistant (FR) and 10 33 slow (S) motor units (MUs), and subsequently decomposed using a mathematical 34 algorithm into trains of twitch-shape responses to successive stimuli. The mean 35 stimulation frequencies were matched for each MU to evoke t...