scholarly journals Bivariate Entropy Analysis of Electrocardiographic RR–QT Time Series

Entropy ◽  
2020 ◽  
Vol 22 (12) ◽  
pp. 1439
Author(s):  
Bo Shi ◽  
Mohammod Abdul Motin ◽  
Xinpei Wang ◽  
Chandan Karmakar ◽  
Peng Li
Keyword(s):  
Resting State ◽  
Conditional Entropy ◽  
Sample Entropy ◽  
Entropy Analysis ◽  
Physiological Conditions ◽  
Dynamic Relationship ◽  
Relationship Of ◽  
Upstream Control ◽  
Qt Interval Variability ◽  
Ventricular Depolarization

QT interval variability (QTV) and heart rate variability (HRV) are both accepted biomarkers for cardiovascular events. QTV characterizes the variations in ventricular depolarization and repolarization. It is a predominant element of HRV. However, QTV is also believed to accept direct inputs from upstream control system. How QTV varies along with HRV is yet to be elucidated. We studied the dynamic relationship of QTV and HRV during different physiological conditions from resting, to cycling, and to recovering. We applied several entropy-based measures to examine their bivariate relationships, including cross sample entropy (XSampEn), cross fuzzy entropy (XFuzzyEn), cross conditional entropy (XCE), and joint distribution entropy (JDistEn). Results showed no statistically significant differences in XSampEn, XFuzzyEn, and XCE across different physiological states. Interestingly, JDistEn demonstrated significant decreases during cycling as compared with that during the resting state. Besides, JDistEn also showed a progressively recovering trend from cycling to the first 3 min during recovering, and further to the second 3 min during recovering. It appeared to be fully recovered to its level in the resting state during the second 3 min during the recovering phase. The results suggest that there is certain nonlinear temporal relationship between QTV and HRV, and that the JDistEn could help unravel this nuanced property.

scholarly journals Conditional Entropy: A Potential Digital Marker for Stress

Entropy ◽  
2021 ◽  
Vol 23 (3) ◽  
pp. 286
Author(s):  
Soheil Keshmiri
Keyword(s):  
Resting State ◽  
Nearest Neighbor ◽  
Brain Activity ◽  
Solution Concept ◽  
Conditional Entropy ◽  
K Nearest Neighbor ◽  
Brain Response ◽  
Substantial Progress ◽  
Eeg Recordings ◽  
The Brain

Recent decades have witnessed a substantial progress in the utilization of brain activity for the identification of stress digital markers. In particular, the success of entropic measures for this purpose is very appealing, considering (1) their suitability for capturing both linear and non-linear characteristics of brain activity recordings and (2) their direct association with the brain signal variability. These findings rely on external stimuli to induce the brain stress response. On the other hand, research suggests that the use of different types of experimentally induced psychological and physical stressors could potentially yield differential impacts on the brain response to stress and therefore should be dissociated from more general patterns. The present study takes a step toward addressing this issue by introducing conditional entropy (CE) as a potential electroencephalography (EEG)-based resting-state digital marker of stress. For this purpose, we use the resting-state multi-channel EEG recordings of 20 individuals whose responses to stress-related questionnaires show significantly higher and lower level of stress. Through the application of representational similarity analysis (RSA) and K-nearest-neighbor (KNN) classification, we verify the potential that the use of CE can offer to the solution concept of finding an effective digital marker for stress.

scholarly journals Multiscale Sample Entropy of Two-Dimensional Decaying Turbulence

Entropy ◽  
2021 ◽  
Vol 23 (2) ◽  
pp. 245
Author(s):  
Ildoo Kim
Keyword(s):  
Time Series ◽  
Time Series Data ◽  
Soap Film ◽  
Sample Entropy ◽  
Series Data ◽  
Entropy Analysis ◽  
Measured Time ◽  
Energetic Analysis ◽  
Turbulence Data ◽  
Decaying Turbulence

Multiscale sample entropy analysis has been developed to quantify the complexity and the predictability of a time series, originally developed for physiological time series. In this study, the analysis was applied to the turbulence data. We measured time series data for the velocity fluctuation, in either the longitudinal or transverse direction, of turbulent soap film flows at various locations. The research was to assess the feasibility of using the entropy analysis to qualitatively characterize turbulence, without using any conventional energetic analysis of turbulence. The study showed that the application of the entropy analysis to the turbulence data is promising. From the analysis, we successfully captured two important features of the turbulent soap films. It is indicated that the turbulence is anisotropic from the directional disparity. In addition, we observed that the most unpredictable time scale increases with the downstream distance, which is an indication of the decaying turbulence.

Inverse sample entropy analysis for stock markets

2021 ◽  
Author(s):  
Yue Wu ◽  
Pengjian Shang ◽  
Jianan Xia
Keyword(s):  
Stock Markets ◽  
Sample Entropy ◽  
Entropy Analysis

scholarly journals Dynamic Relationship of Focal Contacts and Hemidesmosome Protein Complexes in Live Cells

2010 ◽  
Vol 130 (6) ◽  
pp. 1624-1635 ◽  
Author(s):  
Toshiyuki Ozawa ◽  
Daisuke Tsuruta ◽  
Jonathan C.R. Jones ◽  
Masamitsu Ishii ◽  
Kazuo Ikeda ◽  
...  
Keyword(s):  
Protein Complexes ◽  
Live Cells ◽  
Dynamic Relationship ◽  
Focal Contacts ◽  
Relationship Of

scholarly journals Only One Moment in Time? Investigating the Dynamic Relationship of Emotions and Attention Toward Political Information With Mobile Experience Sampling

2019 ◽  
Vol 47 (8) ◽  
pp. 1131-1154
Author(s):  
Lukas P. Otto ◽  
Fabian Thomas ◽  
Michaela Maier ◽  
Charlotte Ottenstein
Keyword(s):  
Sampling Design ◽  
Experience Sampling ◽  
Attentional Focus ◽  
Emotional Reactions ◽  
Political Information ◽  
News Item ◽  
Political News ◽  
Dynamic Relationship ◽  
Relationship Of ◽  
The Relationship

This article attempts to (a) investigate the relationship between distinct emotional reactions toward political information and attention toward political news and (b) analyze whether this relationship is dynamic. We use an experience sampling design to assess recipients’ immediate emotional reactions and attention toward news. Participants reported their emotional reactions (anger, fear, happiness, contentment) and attentional focus directly after following a news item for eight days in a row up to five times a day via smartphone. Results indicate that anger is positively and fear negatively correlated with attention toward political news. For positive emotional reactions, happiness is not correlated with attention to news, while contentment is negatively correlated with attention and also shows a negative lagged effect on attention at a later point in time. The study shows promising ways to assess and analyze dynamic processes in everyday media consumption.

scholarly journals Employees' perceptions of workplace change

2001 ◽  
Vol 24 (4) ◽  
pp. 128 ◽  
Author(s):  
Jeanette London
Keyword(s):  
Health Care Organisation ◽  
Workplace Change ◽  
Individual Level ◽  
Spheres Of Influence ◽  
Dynamic Relationship ◽  
Care Organisation ◽  
General Terms ◽  
Workplace Environments ◽  
Implementation Communication ◽  
Relationship Of

Change is endemic, but it creates fear in the workplace. In this study, five people from a health care organisation were interviewed to gain a better understanding of their concerns in the workplace. Each person regarded the effects of workplace change somewhat differently in variety and intensity but in general terms they all identified two major spheres of influence. Each sphere represents a complex dynamic relationship of several effects. The first, which is at an individual level, includes feelings and attitudes, and behavioural, psychological and social effects. The second, which is at an organisational level, includes culture, leadership, decision making and strategy implementation. Communication and education were viewed as key elements that facilitated the change process. In the surveyed organisation, service closure was viewed as the overriding concern that dominated most participants' perceptions of change. Additional research is required to ascertain if this model can be generalised to other workplace environments.

scholarly journals Entropy Analysis of RR and QT Interval Variability during Orthostatic and Mental Stress in Healthy Subjects

Entropy ◽  
2014 ◽  
Vol 16 (12) ◽  
pp. 6384-6393 ◽  
Author(s):  
Mathias Baumert ◽  
Barbora Czippelova ◽  
Anand Ganesan ◽  
Martin Schmidt ◽  
Sebastian Zaunseder ◽  
...  
Keyword(s):  
Qt Interval ◽  
Mental Stress ◽  
Healthy Subjects ◽  
Entropy Analysis ◽  
Qt Interval Variability
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