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Fano factor analysis was used to characterize the spike trains of single medullary neurons with sympathetic nerve-related activity in cats that were decerebrate or anesthetized with Dial-urethan or urethan. For this purpose, values (Fano factor) of the variance of the number of extracellularly recorded spikes divided by the mean number of spikes were(More)
In 48 conscious resting subjects we examined the temporal coupling of heart beat timing and the onset of inspiration (cardioventilatory coupling), and the relationship between coupling and spectral indices of autonomic function. Using the proportional Shannon entropy (SH(alpha)) of the RI(-1) interval (interval between inspiration and the preceding ECG R(More)
We examined interbreath interval (IBI) time series of 19 term infants during active and quiet sleep for fractal properties using Fano factor analysis. For each time series we calculated the fractal exponent (alpha), comparing alpha for the original time series with two forms of surrogate data, a temporally independent surrogate set and an autoregressive(More)
OBJECTIVES We assessed the impact of restaurant menu calorie labels on food choices and intake. METHODS Participants in a study dinner (n=303) were randomly assigned to either (1) a menu without calorie labels (no calorie labels), (2) a menu with calorie labels (calorie labels), or (3) a menu with calorie labels and a label stating the recommended daily(More)
We describe a simple model of cardioventilatory coupling in which a hypothetical inspiratory pacemaker is stimulated by a signal related to cardiac action. At suitable values for the control variables (cardiac signal magnitude, heart rate, inspiratory pacemaker rate and inspiratory rate variability), the model was found to: (1) replicate all clinically(More)
In a group of spontaneously breathing anaesthetized subjects, we examined the ability of simple spectral and non-linear methods to detect the presence of cardioventilatory coupling in heart rate time series. Using the proportional Shannon entropy (H(RI-1)) of the RI(-1) interval (interval between inspiration and the preceding ECG R wave) as a measure of(More)
We examined spectral components of beat to beat variability in AC and DC signals of the reflectance photoplethysmograph at finger and earlobe sites in 20 resting volunteers and 20 patients during propofol, alfentanil, isoflurane, nitrous oxide anaesthesia. We observed that at rest, the majority of spectral power at both sites and in both signals was in the(More)
Cardioventilatory coupling (CVC), a temporal alignment between the heartbeat and inspiratory activity, is a major determinant of breath-to-breath variation in observed respiratory rate (f(o)). The cardiac-trigger hypothesis attributes this to adjustments of respiratory timing by baroreceptor afferent impulses to the central respiratory pattern generator. A(More)
We have studied the relationship between pulse synchronous baroreceptor input (represented by the arterial pulse, AP) and the cardiac-related rhythm in sympathetic nerve discharge (SND) of urethan-anesthetized cats by using partial autospectral and partial coherence analysis. Partial autospectral analysis was used to mathematically remove the portion of SND(More)
Recent studies have suggested a role for respiratory sinus arrhythmia in improving pulmonary gas transfer. However, the physiological role of cardioventilatory coupling is unknown. We have tested the hypothesis that cardioventilatory coupling aligns heart beats at positions of the ventilatory cycle where they are maximally affected by respiratory sinus(More)