electric activity
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2022 ◽  
Vol 78 (03) ◽  
pp. 6625-2022
Author(s):  
MARIAN GHIȚĂ ◽  
IULIANA CODREANU ◽  
CARMEN PETCU ◽  
ADRIAN RĂDUȚĂ ◽  
DRAGOȘ POPESCU ◽  
...  

The electrocardiogram is a graph recording of heart’s electric activity, so it is used in medical practice mainly in order to observe the heart’s activity. The values of the main components of the electrocardiogram in pregnant goats were determined within the current research. All of these were performed in three different stages of pregnancy (the beginning, the middle and the ending), being focused on the variation of these values during the pregnancy. The gestation diagnosis was confirmed by ultrasound-exam. During the pregnancy, the following values for the duration of the main ECG’s components were found: the P wave (0.045-0.044 s), the P-R segment (0.061-0.048 s), of the P-R range (0.105-0.086 s), of the QRS complex (0.042-0.040 s), of the Q-T range (0.242-0.218 s), of the P-T range (0.377-0.368 s), of the R-R range (0.465-0.431 s), the T wave (0.091-0.104 s) and of the T-P segment (0.097-0.101 s). Our results show that during the pregnancy the duration of: the P wave, the P-R segment, the P-R range, the QRS complex, the Q-T range, the P-T range and the R-R range, decrease, while the duration of the T wave and the T-P segment increase.


Entropy ◽  
2021 ◽  
Vol 23 (12) ◽  
pp. 1655
Author(s):  
Philippe Ravier ◽  
Antonio Dávalos ◽  
Meryem Jabloun ◽  
Olivier Buttelli

Surface electromyography (sEMG) is a valuable technique that helps provide functional and structural information about the electric activity of muscles. As sEMG measures output of complex living systems characterized by multiscale and nonlinear behaviors, Multiscale Permutation Entropy (MPE) is a suitable tool for capturing useful information from the ordinal patterns of sEMG time series. In a previous work, a theoretical comparison in terms of bias and variance of two MPE variants—namely, the refined composite MPE (rcMPE) and the refined composite downsampling (rcDPE), was addressed. In the current paper, we assess the superiority of rcDPE over MPE and rcMPE, when applied to real sEMG signals. Moreover, we demonstrate the capacity of rcDPE in quantifying fatigue levels by using sEMG data recorded during a fatiguing exercise. The processing of four consecutive temporal segments, during biceps brachii exercise maintained at 70% of maximal voluntary contraction until exhaustion, shows that the 10th-scale of rcDPE was capable of better differentiation of the fatigue segments. This scale actually brings the raw sEMG data, initially sampled at 10 kHz, to the specific 0–500 Hz sEMG spectral band of interest, which finally reveals the inner complexity of the data. This study promotes good practices in the use of MPE complexity measures on real data.


2021 ◽  
Author(s):  
Elinor Tzvi ◽  
Leila Gajiyeva ◽  
Laura Bindel ◽  
Gesa Hartwigsen ◽  
Joseph Classen

The cerebellum and its interaction with cortical areas play a key role in our ability to flexibly adapt a motor program in response to sensory input. Current knowledge about specific neural mechanisms underlying the process of visuomotor adaptation is however lacking. Using a novel placement of EEG electrodes to record electric activity from the cerebellum, we studied local cerebellar activity, as well as its coupling with neocortical activity to obtain direct neurophysiological markers of visuomotor adaptation in humans. We found increased theta (4-8Hz) power in cerebellar as well as cortical electrodes, when subjects first encountered a visual perturbation. Theta power decreased as subjects adapted to the perturbation, and rebounded when the perturbation was suddenly removed. This effect was observed in two distinct locations: a cerebellar cluster and a central cluster, which were localized in left cerebellar crus I (lCB) and right supplementary motor area (rSMA) using linear constrained minimum variance beamforming. Importantly, we found that better adaptation was associated with increased theta power in left cerebellar electrodes and a right sensorimotor cortex electrode. Finally, increased rSMA -> lCB connectivity was significantly decreased with adaptation. These results demonstrate that: (1) cerebellar theta power is markedly modulated over the course of visuomotor adaptation and (2) theta oscillations could serve as a key mechanism for communication within a cortico-cerebellar loop.


Author(s):  
Sofiia Berezka ◽  
◽  
Ellina Panasenko ◽  
Oksana Zhukova ◽  
Halyna Radchuk ◽  
...  

The article considers emotional intelligence as a complex integrative formation, which includes cognitive, behavioural and emotional qualities. These qualities ensure awareness, understanding and regulation of their own and others’ emotions and effect on the success of interpersonal interaction and personal development. A review of relevant scientific sources has revealed the insufficient study of brain correlates and the specifics of future psychologists’ emotional intelligence. In turn, it has determined the purpose of the study, that is the neuropsychological study of features of future psychologists’ emotional intelligence. The parameters of emotional intelligence in the first- and second-year students majoring in Specialty 053 Psychology are received due to the test-questionnaire at simultaneous registration of electric activity of the brain. The Neuron-Spectrum 5 electroencephalograph was used for the EEG registration. The recording was performed monopolarly in 32 leads, using samples “eyes closed”, “eyes opened” and filling out the test-questionnaire to identify the levels of emotional intelligence. The obtained results have made it possible to determine that the levels of psychology students’ emotional intelligence are related to the activation indicators of different parts in the cortex of their brain. The students mostly are at average and initial levels of emotional intelligence, tend to show an interpersonal type of emotional intelligence and control their own and others’ emotions rather than to differentiate the emotions and establish the cause of their occurrence.


2021 ◽  
Vol 15 ◽  
Author(s):  
Ekaterina Kopeikina ◽  
Eugene D. Ponomarev

The central nervous system (CNS) is highly vascularized where neuronal cells are located in proximity to endothelial cells, astroglial limitans, and neuronal processes constituting integrated neurovascular units. In contrast to many other organs, the CNS has a blood-brain barrier (BBB), which becomes compromised due to infection, neuroinflammation, neurodegeneration, traumatic brain injury, and other reasons. BBB disruption is presumably involved in neuronal injury during epilepsy and psychiatric disorders. Therefore, many types of neuropsychological disorders are accompanied by an increase in BBB permeability leading to direct contact of circulating blood cells in the capillaries with neuronal cells in the CNS. The second most abundant type of blood cells are platelets, which come after erythrocytes and outnumber ~100-fold circulating leukocytes. When BBB becomes compromised, platelets swiftly respond to the vascular injury and become engaged in thrombosis and hemostasis. However, more recent studies demonstrated that platelets could also enter CNS parenchyma and directly interact with neuronal cells. Within CNS, platelets become activated by recognizing major brain gangliosides on the surface of astrocytes and neurons and releasing a milieu of pro-inflammatory mediators, neurotrophic factors, and neurotransmitters. Platelet-derived factors directly stimulate neuronal electric and synaptic activity and promote the formation of new synapses and axonal regrowth near the site of damage. Despite such active involvement in response to CNS damage, the role of platelets in neurological disorders was not extensively studied, which will be the focus of this review.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
D. I. Khomskii

AbstractSpin ice systems display a variety of very nontrivial properties, the most striking being the existence in them of magnetic monopoles. Such monopole states can also have nontrivial electric properties: there exist electric dipoles attached to each monopole. A novel situation is encountered in the moment fragmentation (MF) state, in which monopoles and antimonopoles are perfectly ordered, whereas spins themselves remain disordered. We show that such partial ordering strongly modifies the electric activity of such systems: the electric dipoles, which are usually random and dynamic, become paired in the MF state in (d, −d) pairs, thus strongly reducing their electric activity. The electric currents existing in systems with noncoplanar spins are also strongly influenced by MF. We also consider modifications in dipole and current patterns in magnetic textures (domain walls, local defects) and at excitations with nontrivial dynamics in a MF state, which show very rich behaviour and which could in principle allow to control them by electric field.


Author(s):  
O. E. Dik ◽  

Based on the analysis of joint recurrence plots of the brain’s response to functional load in the form of rhythmic photostimulation, quantitative indicators of changes in the bioelectrical activity of the brain of patients with moderate cognitive impairments were revealed before and after the method of therapy associated with the formation of stable functional brain connections. It has been shown that such therapy, leading to an improvement in the condition of patients, correlates with changes in the indicators of joint recurrence plots of the bioelectrical activity of the brain and photostimulus.


Author(s):  
Ganesh Birajadar, Et. al.

Electroencephalogram (EEG) is nothing but measuring electric activity of brain. EEG is non-stationary signal. EEG characterizes human behavior. There are many brain abnormalities that can be identified and treated using EEG behavior analysis. As per researchers study Epilepsy is commonly happening disorder that is getting spread over the time. It is nothing but sudden stroke in brain where patient suffers from unusual activities seizures. Sometimes symptoms are such severe that ignorance leads to death. So it is important to identify its earlier symptoms and treat it in time so as to avoid risk. EEG signals are used for getting features in time as well as frequency domain. These features are further analyzed and classified to identify EEG abnormality.  


Author(s):  
Diana Campos-Beltrán ◽  
Lisa Marshall

AbstractSleep is one of the most ubiquitous but also complex animal behaviors. It is regulated at the global, systems level scale by circadian and homeostatic processes. Across the 24-h day, distribution of sleep/wake activity differs between species, with global sleep states characterized by defined patterns of brain electric activity and electromyography. Sleep patterns have been most intensely investigated in mammalian species. The present review begins with a brief overview on current understandings on the regulation of sleep, and its interaction with aging. An overview on age-related variations in the sleep states and associated electrophysiology and oscillatory events in humans as well as in the most common laboratory rodents follows. We present findings observed in different studies and meta-analyses, indicating links to putative physiological changes in the aged brain. Concepts requiring a more integrative view on the role of circadian and homeostatic sleep regulatory mechanisms to explain aging in sleep are emerging.


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