Anomalous Stochastic Transport of Particles with Self-Reinforcement and Mittag–Leffler Distributed Rest Times

We introduce a persistent random walk model for the stochastic transport of particles involving self-reinforcement and a rest state with Mittag–Leffler distributed residence times. The model involves a system of hyperbolic partial differential equations with a non-local switching term described by the Riemann–Liouville derivative. From Monte Carlo simulations, we found that this model generates superdiffusion at intermediate times but reverts to subdiffusion in the long time asymptotic limit. To confirm this result, we derived the equation for the second moment and find that it is subdiffusive in the long time limit. Analyses of two simpler models are also included, which demonstrate the dominance of the Mittag–Leffler rest state leading to subdiffusion. The observation that transient superdiffusion occurs in an eventually subdiffusive system is a useful feature for applications in stochastic biological transport.

Hypoventilation Yoga Exercises: Effects on Respiratory Metabolism

Aim. Assessment of changes in respiratory metabolism and parameters of external respiration during hypoventilation yoga exercises. Material and methods. 22 experienced volunteers (18 men and 4 women, mean age 42.95 ± 8.14 years) performed yoga breathing exercises with a frequency of 3 times per minute, 1.5 times per minute, 1 time per minute, as well as free breathing for 2 minutes. Respiratory rate (RR), minute ventilation (MV), tidal volume (TV), partial pressure of CO2 in expired air at the end of exhalation (PetCO2), percentage of O2 in expired air (FeO2) and hemoglobin saturation (SpO2) were recorded. Results and discussion. The breathing regimen with RR = 3 times / min is hyperventilating, accompanied by a statistically significant increase in respiratory minute volume (RMV) and a decrease in PetCO2; hemoglobin saturation indices are not changed. Breathing with a frequency of 1.5 times/min is accompanied by a statistically significant decrease in RMV compared to the rest state, as well as an increase in PetCO2 and a decrease in FeO2, that is, it is hypoventilating, although there is a certain heterogeneity within this subgroup depending on the recruited tidal volume. Indicators of hemoglobin saturation with a given breathing mode do not change. The breathing regimen with RR = 1 time / min is accompanied by a statistically significant decrease in the RMV, an increase in PetCO2 and a decrease in FeO2; the average values of hemoglobin saturation do not change, but the minimum saturation values (observed once during each respiratory cycle) are statistically significantly lower than at the rest state. These results suggest that hypoventilating yoga exercises may have a positive effect on cerebral blood flow and cerebrovascular reactivity. Conclusion. Performing yoga breathing exercises at the respiration rate of 1.5 and 1 times per minute is accompanied by statistically significant hypoventilation, alveolar hypercapnia and hypoxia.

Time series analysis of trial-to-trial variability of MEG power spectrum during rest state, unattented listening and frequency-modulated tones classification

The nonstationarity of EEG/MEG signals is important for understanding the functioning of human brain. From the previous research we know that even very short, i.e. 250—500ms MEG signals are variance-nonstationary. The covariance of stochastic process is mathematically associated with its spectral density, therefore we investigate how the spectrum of such nonstationary signals varies in time.We analyze the data from 148-channel MEG, that represent rest state, unattented listening and frequency-modulated tones classification. We transform short-time MEG signals to the frequency domain using the FFT algorithm and for the dominant frequencies 8—12 Hz we prepare the time series representing their trial-to-trial variability. Then, we test them for level- and trend-stationarity, unit root, heteroscedasticity and gaussianity and based on their properties we propose the ARMA-modelling for their description.The analyzed time series have the weakly stationary properties independently of the functional state of brain and localization. Only their small percentage, mostly related to the cognitive task, still presents nonstationarity. The obtained mathematical models show that the spectral density of analyzed signals depends on only 2—3 previous trials.The presented method has limitations related to FFT resolution and univariate models, but it is not computationally complicated and allows to obtain a low-complex stochastic models of the EEG/MEG spectrum variability.Although the physiological short-time MEG signals are in principle nonstationary in time domain, its power spectrum at the dominant frequencies varies as weakly stationary stochastic process. Described technique has the possible applications in prediction of the EEG/MEG spectral properties in theoretical and clinical neuroscience.

Ultrasonic evaluation of muscle functional recovery following free functioning gracilis transfer, a preliminary study

Background Ultrasonic measurement has not been utilized to assess the functional recovery of transplanted muscle. This study aimed to investigate the feasibility of using B-ultrasound measurement to assess muscle recovery following free functioning gracilis transfer. Methods From January 2009 to January 2014, 35 patients receiving free functioning gracilis transfer to treat total brachial plexus injury were enrolled. B-ultrasound was adopted to determine the cross-sectional area (CSA) of transplanted gracilis muscle at rest and contraction state. The ratio of pre- to post-transplant CSA value at rest state was defined as muscle bulk ratio (MBR). The ratio of CSA value at contraction state to rest state was defined as contraction ratio (CR). Results Patients with muscle strength M ≥ 4 had significantly higher CR1 (post-transplant), CR2 (pre-transplant), and range of motion (ROM, joint mobility) than those with muscle strength M < 4. The CR1 > CR2 group had significantly higher CR1, muscle strength, and ROM than the CR1 ≤ CR2 group. The MBR > 1 group had significantly higher muscle strength than the MBR ≤ 1 group. CR1 value was highly correlated with muscle strength and with ROM. CR2 value was moderately correlated with muscle strength and ROM. Multivariate linear regression analysis showed that a higher CR1/CR2 value was associated with a higher muscle strength and joint mobility. The CR1 > CR2 group had better muscle strength and ROM than the CR1 ≤ CR2 groups. Conclusion B-ultrasound measurement can quantitatively reflect muscle strength following gracilis transfer, and CR value could be a potential indicator for functional recovery of the transplanted gracilis muscle. Level of Evidence: Prognostic studies, Level II.

Abnormal regional homogeneity and its relationship with symptom severity in cervical dystonia: a rest state fMRI study

Background Although several brain networks play important roles in cervical dystonia (CD) patients, regional homogeneity (ReHo) changes in CD patients have not been clarified. We investigated to explore ReHo in CD patients at rest and analyzed its correlations with symptom severity as measured by Tsui scale. Methods A total of 19 CD patients and 21 gender-, age-, and education-matched healthy controls underwent fMRI scans at rest state. Data were analyzed by ReHo method. Results Patients showed increased ReHo in the right cerebellum crus I and decreased ReHo in the right superior medial prefrontal cortex (MPFC). Moreover, the right precentral gyrus, right insula, and bilateral middle cingulate gyrus also showed increased ReHo values. A significantly positive correlation was observed between ReHo value in the right cerebellum crus I and symptom severity (p < 0.05). Conclusions Our investigation suggested abnormal ReHo existed in brain regions of the “pain matrix” and salience network (the right insula and bilateral middle cingulate gyrus), the motor network (the right precentral gyrus), the cerebellum and MPFC and further highlighted the significance of these networks in the pathology of CD.

Abnormal regional homogeneity and its relationship with symptom severity in cervical dystonia: A rest state fMRI study

Background: Although several brain networks play important roles in cervical dystonia (CD) patients, regional homogeneity (ReHo) changes in CD patients have not been clarified. We investigated to explore ReHo in CD patients at rest and analyzed its correlations with symptom severity as measured by Tsui scale.Methods: A total of 19 CD patients and 21 gender-, age-, and education-matched healthy controls underwent fMRI scans at rest state. Data were analyzed by ReHo method.Results: Patients showed increased ReHo in the right cerebellum crus I and decreased ReHo in the right superior medial prefrontal cortex (MPFC). Moreover, the right precentral gyrus, right insula, and bilateral middle cingulate gyrus also showed increased ReHo values. A significantly positive correlation was observed between ReHo value in the right cerebellum crus I and symptom severity (p < 0.05).Conclusions: Our investigation suggested abnormal ReHo existed in brain regions of the "pain matrix" and salience network (the right insula and bilateral middle cingulate gyrus), the motor network (the right precentral gyrus), the cerebellum and MPFC and further highlighted the significance of these networks in the pathology of CD.

Abnormal regional homogeneity and its relationship with symptom severity in cervical dystonia: A rest state fMRI study

Background: Although several brain networks play important roles in cervical dystonia (CD) patients, regional homogeneity (ReHo) changes in CD patients have not been clarified. We investigated to explore ReHo in CD patients at rest and analyzed its correlations with symptom severity as measured by Tsui scale.Methods: A total of 19 CD patients and 21 gender-, age-, and education-matched healthy controls underwent fMRI scans at rest state. Data were analyzed by ReHo method.Results: Patients showed increased ReHo in the right cerebellum crus I and decreased ReHo in the right superior medial prefrontal cortex (MPFC). Moreover, the right precentral gyrus, right insula, and bilateral middle cingulate gyrus also showed increased ReHo values. A significantly positive correlation was observed between ReHo value in the right cerebellum crus I and symptom severity (p < 0.05).Conclusions: Our investigation suggested abnormal ReHo existed in brain regions of the "pain matrix" and salience network (the right insula and bilateral middle cingulate gyrus), the motor network (the right precentral gyrus), the cerebellum and MPFC and further highlighted the significance of these networks in the pathology of CD.

Cognitive Analytics for Rapid Stress Relief in Humans Using EEG Based Analysis of Tratak Sadhana (Meditation)

The article reports the effect of Tratak Sadhana (meditation) on humans using electroencephalograph (EEG) signals. EEG represents the brain activities in the form of electrical signals. Due to non-stationary nature of the EEG signals, nonlinear parameters like approximate entropy, wavelet entropy and Higuchi' fractal dimensions are used to assess the variations in EEG rest as well as during Tratak Sadhana, i.e. at a rest state with eyes closed and during Tratak meditation. EEG signals are captured using EPOC Emotive EEG sensor. The sensor has 14 electrodes covering human scalp. Results shows that new practitioners can also achieve a rapid meditative state as compared to other meditation techniques. Further, the Big Data perspective of the present study is discussed. The present study shows that Tratak Sadhana meditation is an effective tool for rapid stress relief in humans.