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multiscale entropy

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https://www.readbyqxmd.com/read/28877180/decreased-complexity-of-glucose-dynamics-preceding-the-onset-of-diabetes-in-mice-and-rats
#1
Xiaohua Douglas Zhang, David Pechter, Liming Yang, Xiaoli Ping, Zuliang Yao, Rumin Zhang, Xiaolan Shen, Nina Xiaoyan Li, Jonathan Connick, Andrea R Nawrocki, Manu Chakravarthy, Cai Li
Continuous glucose monitoring (CGM) is a platform to measure blood glucose (BG) levels continuously in real time with high enough resolution to document their underlying fluctuations. Multiscale entropy (MSE) analysis has been proposed as a measure of time-series complexity, and when applied to clinical CGM data, MSE analysis revealed that diabetic patients have lower MSE complexity in their BG time series than healthy subjects. To determine if the clinical observations on complexity of glucose dynamics can be back-translated to relevant preclinical species used routinely in diabetes drug discovery, we performed CGM in both mouse (ob/ob) and rat (Zucker Diabetic Fatty, ZDF) models of diabetes...
2017: PloS One
https://www.readbyqxmd.com/read/28845049/reactive-molecular-dynamics-models-from-ab-initio-molecular-dynamics-data-using-relative-entropy-minimization
#2
Christopher Arntsen, Chen Chen, Gregory A Voth
We present two new multiscale molecular dynamics (MS-RMD) models for the hydrated excess proton in water developed directly from ab initio molecular dynamics (AIMD) simulation data of the same system. The potential of mean force along the proton transfer reaction coordinate and radial distribution functions for the MS-RMD models are shown faithfully reproduce those of AIMD. The models are developed using an algorithm based on relative entropy minimization, thus demonstrating the ability of the method to rapidly generate accurate and highly efficient reactive MD force fields...
September 1, 2017: Chemical Physics Letters
https://www.readbyqxmd.com/read/28839247/spatiotemporal-changes-in-regularity-of-gamma-oscillations-contribute-to-focal-ictogenesis
#3
Yosuke Sato, Simeon M Wong, Yasushi Iimura, Ayako Ochi, Sam M Doesburg, Hiroshi Otsubo
In focal ictogenesis, gamma oscillations (30-70 Hz) recorded by electroencephalography (EEG) are related to the epileptiform synchronization of interneurons that links the seizure onset zone (SOZ) to the surrounding epileptogenic zone. We hypothesized that the synchronization of interneurons could be detected as changes in the regularity of gamma oscillation rhythmicity. We used multiscale entropy (MSE) analysis, which can quantify the regularity of EEG rhythmicity, to investigate how the regularity of gamma oscillations changes over the course of a seizure event...
August 24, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28782680/bilinguals-have-more-complex-eeg-brain-signals-in-occipital-regions-than-monolinguals
#4
John G Grundy, John A E Anderson, Ellen Bialystok
Brain signal complexity increases with development and is associated with better cognitive outcomes in older age. Research has also shown that bilinguals are able to stave off cognitive decline for longer periods of time than monolinguals, but no studies to date have examined whether bilinguals have more complex brain signals than monolinguals. Here we explored the hypothesis that bilingualism leads to greater brain signal complexity by examining multiscale entropy (MSE) in monolingual and bilingual young adults while EEG was recorded during a task-switching paradigm...
August 4, 2017: NeuroImage
https://www.readbyqxmd.com/read/28769817/suicidal-ideation-is-associated-with-altered-variability-of-fingertip-photo-plethysmogram-signal-in-depressed-patients
#5
Ahsan H Khandoker, Veena Luthra, Yousef Abouallaban, Simanto Saha, Khawza I U Ahmed, Raqibul Mostafa, Nayeefa Chowdhury, Herbert F Jelinek
Physiological and psychological underpinnings of suicidal behavior remain ill-defined and lessen timely diagnostic identification of this subgroup of patients. Arterial stiffness is associated with autonomic dysregulation and may be linked to major depressive disorder (MDD). The aim of this study was to investigate the association between arterial stiffness by photo-plethysmogram (PPG) in MDD with and without suicidal ideation (SI) by applying multiscale tone entropy (T-E) variability analysis. Sixty-one 10-min PPG recordings were analyzed from 29 control, 16 MDD patients with (MDDSI+) and 16 patients without SI (MDDSI-)...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/28763292/quantifying-the-dynamics-of-electroencephalographic-eeg-signals-to-distinguish-alcoholic-and-non-alcoholic-subjects-using-an-mse-based-k-d-tree-algorithm
#6
Lal Hussain, Wajid Aziz, Sharjil Saeed, Saeed Arif Shah, Malik Sajjad A Nadeem, Imtiaz Ahmed Awan, Ali Abbas, Abdul Majid, Syed Zaki Hassan Kazmi
In this paper, we have employed K-d tree algorithmic based multiscale entropy analysis (MSE) to distinguish alcoholic subjects from non-alcoholic ones. Traditional MSE techniques have been used in many applications to quantify the dynamics of physiological time series at multiple temporal scales. However, this algorithm requires O(N2), i.e. exponential time and space complexity which is inefficient for long-term correlations and online application purposes. In the current study, we have employed a recently developed K-d tree approach to compute the entropy at multiple temporal scales...
August 1, 2017: Biomedizinische Technik. Biomedical Engineering
https://www.readbyqxmd.com/read/28750035/the-modulation-of-eeg-variability-between-internally-and-externally-driven-cognitive-states-varies-with-maturation-and-task-performance
#7
Jessie M H Szostakiwskyj, Stephanie E Willatt, Filomeno Cortese, Andrea B Protzner
Increasing evidence suggests that brain signal variability is an important measure of brain function reflecting information processing capacity and functional integrity. In this study, we examined how maturation from childhood to adulthood affects the magnitude and spatial extent of state-to-state transitions in brain signal variability, and how this relates to cognitive performance. We looked at variability changes between resting-state and task (a symbol-matching task with three levels of difficulty), and within trial (fixation, post-stimulus, and post-response)...
2017: PloS One
https://www.readbyqxmd.com/read/28682254/multiscale-shannon-s-entropy-modelling-of-orientation-and-distance-in-steel-fiber-micro-tomography-data
#8
John P Chiverton, Olubisi Ige, Stephanie J Barnett, Tony Parry
This work is concerned with the modelling and analysis of the orientation and distance between steel fibers in Xray Micro-Tomography (XCT) data. The advantage of combining both orientation and separation in a model is that it helps provide a detailed understanding of how the steel fibers are arranged, which is easy to compare. The developed models are designed to summarise the randomness of the orientation distribution of the steel fibers both locally and across an entire volume based on multiscale entropy...
June 30, 2017: IEEE Transactions on Image Processing: a Publication of the IEEE Signal Processing Society
https://www.readbyqxmd.com/read/28660343/tissue-mineral-density-measured-at-the-sub-millimetre-scale-can-provide-reliable-statistics-of-elastic-properties-of-bone-matrix
#9
Davide Gagliardi, Salah Naili, Christophe Desceliers, Vittorio Sansalone
Reliability of multiscale models of bone is related to the accuracy of the experimental information available on bone microstructure. X-ray-based imaging techniques allow to inspect bone structure and mineralization in vitro at the micrometre scale. However, spatial resolution achievable in vivo is much coarser and can produce blurry, uncertain information on bone microstructure. Working with uncertain data calls for new modelling paradigms able to propagate uncertainty through the scales. In this paper we investigate the effects of uncertain bone mineralization on the elastic coefficients of the bone matrix...
June 28, 2017: Biomechanics and Modeling in Mechanobiology
https://www.readbyqxmd.com/read/28653659/continuous-assessment-of-schizophrenia-using-heart-rate-and-accelerometer-data
#10
Erik Reinertsen, Maxim Osipov, Chengyu Liu, John M Kane, Georgios Petrides, Gari D Clifford
OBJECTIVE: Schizophrenia has been associated with changes in heart rate (HR) and physical activity measures. However, the relationship between analysis window length and classifier accuracy using these features has yet to be quantified. APPROACH: Here we used objective HR and activity data to classify contiguous days of data as belonging to a schizophrenia patient or a healthy control. HR and physical activity recordings were made on 12 medicated subjects with schizophrenia and 12 healthy controls...
June 27, 2017: Physiological Measurement
https://www.readbyqxmd.com/read/28628398/skill-level-changes-the-coordination-and-variability-of-standing-posture-and-movement-in-a-pistol-aiming-task
#11
Ji-Hyun Ko, Dong-Wook Han, Karl M Newell
The study investigated the coordination and variability of posture and pistol motion for skilled pistol shooters and novices in a pistol-aiming task. The participants stood on a force platform and held a pistol with the preferred arm to aim for accuracy to a target on 30 s trials. The results revealed that the amount of the centre of pressure (COP) and pistol motion was lower for the expert than novice group. The time-varying structure of COP as indexed by multiscale entropy (MSE) and detrended fluctuation analysis (DFA) was also lower for the expert than the novice group...
June 19, 2017: Journal of Sports Sciences
https://www.readbyqxmd.com/read/28599118/sensory-metrics-of-neuromechanical-trust
#12
William Softky, Criscillia Benford
Today digital sources supply a historically unprecedented component of human sensorimotor data, the consumption of which is correlated with poorly understood maladies such as Internet addiction disorder and Internet gaming disorder. Because both natural and digital sensorimotor data share common mathematical descriptions, one can quantify our informational sensorimotor needs using the signal processing metrics of entropy, noise, dimensionality, continuity, latency, and bandwidth. Such metrics describe in neutral terms the informational diet human brains require to self-calibrate, allowing individuals to maintain trusting relationships...
September 2017: Neural Computation
https://www.readbyqxmd.com/read/28592844/the-complexity-of-standing-postural-sway-associates-with-future-falls-in-community-dwelling-older-adults-the-mobilize-boston-study
#13
Junhong Zhou, Daniel Habtemariam, Ikechukwu Iloputaife, Lewis A Lipsitz, Brad Manor
Standing postural control is complex, meaning that it is dependent upon numerous inputs interacting across multiple temporal-spatial scales. Diminished physiologic complexity of postural sway has been linked to reduced ability to adapt to stressors. We hypothesized that older adults with lower postural sway complexity would experience more falls in the future. 738 adults aged ≥70 years completed the Short Physical Performance Battery test (SPPB) test and assessments of single and dual-task standing postural control...
June 7, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28507237/multiscale-ordinal-network-analysis-of-human-cardiac-dynamics
#14
M McCullough, M Small, H H C Iu, T Stemler
In this study, we propose a new information theoretic measure to quantify the complexity of biological systems based on time-series data. We demonstrate the potential of our method using two distinct applications to human cardiac dynamics. Firstly, we show that the method clearly discriminates between segments of electrocardiogram records characterized by normal sinus rhythm, ventricular tachycardia and ventricular fibrillation. Secondly, we investigate the multiscale complexity of cardiac dynamics with respect to age in healthy individuals using interbeat interval time series and compare our findings with a previous study which established a link between age and fractal-like long-range correlations...
June 28, 2017: Philosophical Transactions. Series A, Mathematical, Physical, and Engineering Sciences
https://www.readbyqxmd.com/read/28495840/nonlinearities-of-heart-rate-variability-in-animal-models-of-impaired-cardiac-control-contribution-of-different-time-scales
#15
Luiz Eduardo Virgilio Silva, Renata Maria Lataro, Jaci Airton Castania, Carlos Alberto Aguiar Silva, Helio C Salgado, Rubens Fazan, Alberto Porta
Heart rate variability (HRV) has been extensively explored by traditional linear approaches (e.g. spectral analysis). However, several studies have pointed to the presence of nonlinear features in HRV, suggesting that linear tools might fail to account for the complexity of the HRV dynamics. Even though the prevalent notion is that HRV is nonlinear, the actual presence of nonlinear features is rarely verified. In this study, the presence of nonlinear dynamics was checked as a function of time scales in three experimental models of rats with different impairment of the cardiac control, namely rats with heart failure (HF), spontaneously hypertensive rats (SHRs) and sinoaortic denervated (SAD) rats...
May 11, 2017: Journal of Applied Physiology
https://www.readbyqxmd.com/read/28484994/associations-of-blood-glucose-dynamics-with-antihyperglycemic-treatment-and-glycemic-variability-in-type-1-and-type-2-diabetes
#16
K-D Kohnert, P Heinke, L Vogt, P Augstein, A Thomas, E Salzsieder
AIMS: The dynamical structure of glucose fluctuation has largely been disregarded in the contemporary management of diabetes. METHODS: In a retrospective study of patients with diabetes, we evaluated the relationship between glucose dynamics, antihyperglycemic therapy, glucose variability, and glucose exposure, while taking into account potential determinants of the complexity index. We used multiscale entropy (MSE) analysis of continuous glucose monitoring data from 131 subjects with type 1 (n = 18), type 2 diabetes (n = 102), and 11 nondiabetic control subjects...
May 8, 2017: Journal of Endocrinological Investigation
https://www.readbyqxmd.com/read/28462498/refined-multiscale-fuzzy-entropy-based-on-standard-deviation-for-biomedical-signal-analysis
#17
Hamed Azami, Alberto Fernández, Javier Escudero
Multiscale entropy (MSE) has been a prevalent algorithm to quantify the complexity of biomedical time series. Recent developments in the field have tried to alleviate the problem of undefined MSE values for short signals. Moreover, there has been a recent interest in using other statistical moments than the mean, i.e., variance, in the coarse-graining step of the MSE. Building on these trends, here we introduce the so-called refined composite multiscale fuzzy entropy based on the standard deviation (RCMFEσ) and mean (RCMFEμ) to quantify the dynamical properties of spread and mean, respectively, over multiple time scales...
May 2, 2017: Medical & Biological Engineering & Computing
https://www.readbyqxmd.com/read/28437466/stage-call-cardiovascular-reactivity-to-audition-stress-in-musicians
#18
Theerasak Chanwimalueang, Lisa Aufegger, Tricia Adjei, David Wasley, Cinzia Cruder, Danilo P Mandic, Aaron Williamon
Auditioning is at the very center of educational and professional life in music and is associated with significant psychophysical demands. Knowledge of how these demands affect cardiovascular responses to psychosocial pressure is essential for developing strategies to both manage stress and understand optimal performance states. To this end, we recorded the electrocardiograms (ECGs) of 16 musicians (11 violinists and 5 flutists) before and during performances in both low- and high-stress conditions: with no audience and in front of an audition panel, respectively...
2017: PloS One
https://www.readbyqxmd.com/read/28383496/measuring-complexity-and-predictability-of-time-series-with-flexible-multiscale-entropy-for-sensor-networks
#19
Renjie Zhou, Chen Yang, Jian Wan, Wei Zhang, Bo Guan, Naixue Xiong
Measurement of time series complexity and predictability is sometimes the cornerstone for proposing solutions to topology and congestion control problems in sensor networks. As a method of measuring time series complexity and predictability, multiscale entropy (MSE) has been widely applied in many fields. However, sample entropy, which is the fundamental component of MSE, measures the similarity of two subsequences of a time series with either zero or one, but without in-between values, which causes sudden changes of entropy values even if the time series embraces small changes...
April 6, 2017: Sensors
https://www.readbyqxmd.com/read/28336915/a-novel-method-of-evaluating-knee-joint-stability-of-patients-with-knee-osteoarthritis-multiscale-entropy-analysis-with-a-knee-aiming-task
#20
Diange Zhou, Shijie Zhang, Hui Zhang, Long Jiang, Jue Zhang, Jing Fang
Deteriorating knee stability is a local risk factor that reflects the occurrence and aggregative of osteoarthritis (OA). Despite the many biomechanics-based methods for assessing the structural stability of knee joints in clinics, these methods have many limitations. The stability of the knee joint relies on not only biomechanical factors, but also proprioception and the central nervous system. In this study, we attempt to depict the stability of knee joint from a holistic viewpoint, and a novel index of knee joint stability (IKJS) was thus extracted...
March 23, 2017: Scientific Reports
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