Search results for "rhythm"

Production and chronobiology of emergence of the cercariae of Euparyphium albuferensis (Trematoda: Echinostomatidae).

1999

The production and the chronobiology of emergence of the cercariae of Euparyphium albuferensis from Gyraulus chinensis experimentally infected with a single miracidium were established during 28 consecutive days from the first day of cercarial shedding. Moreover, the effect of a sudden change in light-dark cycling was investigated. Although the daily cercarial shedding rates show great variability, a progressive increase in cercarial production was observed in the first weeks of the cercarial shedding periods, probably in relation to the demography of intramollusean larval stages. Under 12:12 light-dark cycling condition;, it, albuferensis cercariae emerged in the light, and the rhythm was …

Diurnal changes in the perception of emotions in music: Does the time of day matter?

2014

According to the Hindustani music tradition, the ability of a song to induce certain emotions depends on the time of day: playing a song at the right time is said to maximise its emotional effect. The present exploratory study investigated this claim by combining findings in chronobiology, mood research and music perception. It has already been established that some aspects of our mood fluctuations follow a cyclical pattern. Besides, it is a known fact that our current mood influences our perception and assessment of emotions. However, these elements have never been linked together in a study examining the effect of mood cyclicity on perceived emotions in music. To test the hypothesis of a…

Diurnal variation of corticotropin-releasing factor binding sites in the rat brain and pituitary.

1996

1. Corticotropin-releasing factor (CRF) is thought to be involved in the regulation of the diurnal activity of the hypothalamus-pituitary-adrenal (HPA) axis and to act as a neurotransmitter in the brain. To date it is unknown whether the binding sites of the central CRF system are subject to diurnal variations. 2. We measured the number of CRF binding sites over the course of a complete 24-hr light-dark cycle in the pituitary, amygdala, bed nucleus of the stria terminalis (BNST), cingulate cortex, visceral cortex, paraventricular nucleus of the hypothalamus, hippocampus, and locus ceruleus of rats by in vitro receptor autoradiography with iodinated ovine CRF. A 24-hr time course was also es…

Cardiac Remodeling According to the Nocturnal Fall of Blood Pressure in Hypertensive Subjects: The Whole Assessment of Cardiac Abnormalities in Non-D…

2021

Objective: Several epidemiological studies suggest that the preservation of the physiological circadian rhythm of blood pressure or its disruption affects the extent of the organ damage developed by the patient. If we classify the circadian rhythm of blood pressure into four nocturnal profiles, significant differences emerge in terms of organ damage burden and prognosis: reverse dippers have the worst prognosis while dippers and mild dippers fall into an intermediate risk range. The risk profile of extreme dippers is still debated, and the available data are very conflicting and inconclusive. Starting from this gap of knowledge, we aimed to evaluate, retrospectively, in a cohort of hyperten…

A fifth class of antiarrhythmic action?

1981

La agrupación temporal y los patrones como facilitadores de la comprensión psicológica de la información rítmica

2020

Grouping influences the mental fragmentation of sounds in memory, which is why it is considered a fundamental element in modern theories of musical cognition. This work reviews research on the phenomena of temporal structuring, grouping of events and formation of rhythmic patterns. Therefore, an updated panorama is offered regarding certain facilitating factors of temporal processing that may be relevant in musical training contexts, for example, that regularity and the 2:1 relationship are important elements for the perception and production of rhythmic patterns. La agrupación influye en la fragmentación de sonidos en la memoria, por lo que es considerada un elemento fundamental en las teo…

Tempo Induction from Music Recordings Using Ensemble Empirical Mode Decomposition Analysis

2011

Tempo and beat are among the most important features of Western music. Owing to the perceptual nature of tempo, its automatic analysis and extraction remains a difficult task for a large variety of music genres. Western music notation represents musical events using a hierarchical metrical structure distinguishing different time scales. This hierarchy is often modeled using three levels: the tatum, the tactus, and the measure. The tatum represents the shortest durational value in music that is not just an accidental phenomenon (Bilmes 1993). The tactus period is the most perceptually prominent period, and is the period at which most humans would tap their feet in time with the music (Lerdah…

Improving diagnostic accuracy of MDCT coronary angiography in patients with mild heart rhythm irregularities using ECG editing

2006

OBJECTIVE. The objective of our study was to compare diagnostic accuracy of MDCT coronary angiography in a population of patients with mild heart rhythm irregularities before and after editing the ECG. SUBJECTS AND METHODS. Thirty-eight patients who underwent MDCT coronary angiography and conventional coronary angiography were enrolled in the study. The inclusion criterion was the presence of mild heart rhythm irregularities (i.e., premature beats; atrial fibrillation; mistriggering; or low heart rate, defined as 40 beats per minute or less) during the scan. All patients underwent MDCT with the following parameters: 16 detectors; collimation, 0.75 mm; gantry rotation time, 375 msec; 120 kV;…

Non-linear dynamics of alpha and theta rhythm: correlation dimensions and Lyapunov exponents from healthy subject's spontaneous EEG.

1997

The aim of the present paper was to analyze some non-linear dynamic properties of the resting EEG from healthy subjects under eyes closed conditions. For this purpose we digitally filtered the spontaneous EEG in the theta (3-8 Hz) and alpha frequency range (8-13 Hz) and considered these independent rhythms as signals from a deterministic system. Under certain conditions non-linear dynamic systems are able to generate deterministic chaos, which means that similar causes do not produce similar effects. This phenomenon is called sensitive dependence on initial conditions. From different lead positions (F3, F4, Cz, P3, P4, O1 and O2) we calculated the so-called correlation dimension D2, which i…

Kognitive Prozesse und dynamische Zeitstrukturen. Vorstellung eines Meßgerätes zur Untersuchung der Mikro-Vigilanz-Shift-(MVS-)Hypothese. Cognitive P…

2003

The psychophysiological measuring method for the determination of the auditory order threshold (OT) is steadily gaining in importance, both for the diagnosis and treatment of speech disorders. Observed intraindividual variability of (macro-) vigilance led to the hypothesis of discontinuous cognitive processing in the central nervous system. The base for the variability of microvigilance is hypothesized to be in the phase difference of the alpha rhythm. To test for this hypothesis, we developed an EEG-comparator, which allows for a phase-dependent triggering of external stimuli. In direct comparison with stochastic (i.e. non-phase-dependent) stimulus presentation, the threshold in phase-depe…