LFPs coding working memory task via information entropy using plugin method / 国际生物医学工程杂志

Objective Toinvestigatetheentropyoflocalfieldpotentials(LFPs)recordedinratmedialprefrontal cortex during a Y-maze working memory (WM) task, to provide computing support for neural coding mechanism.Methods Sixteen-channel LFPs were recorded from SD rats while they performed a Y-maze WM task.The data came from 4 rats, 20 trials (10 correct trials and 10 incorrect trials) per rat provided by laboratory of neurobiology in medicine,Tianjin Medical University.Original LFPs were preprocessed to remove 50 Hz power line noise and baseline drift.Multi-taper Fourier transform was applied to calculate spatial distributions of LFPs and band pass filter were used to extract characteristic signal.The entroy coding of 16 channel LFPs was as follows: the physiological window was set to be 500 ms, the step length of physiological window was set to be 125 ms, windows were added to LFPs data, and then LFPs entropy of each sliding window was computed and averaged to get the trend of multichannel entropy values duringthe WM task.Results The power of θ band (4-12 Hz) in LFPs increased.The averaged entropy value ofmultichannel θ band LFPs in correct trials was 0.939±-0.020, which were larger than those in the resting state, 0.795±0.031 (P＜0.05).Those during wrong WM task had no significant difference, which didn't encode the WM task.Conclusions The principal frequency band related to WM is the θ band and LFPs entropy encodes the WM effectively.

Heart rate dynamics by novel chaotic globals to HRV in obese youths

OBJECTIVE: this study aimed to assess the heart rate dynamics in young obese subjects by novel chaotic globals to HRV METHODS: eighty-six young subjects were distributed in two equal groups (n = 43) according to the nutritional status: obese and control following Body Mass Index. For the analysis of HRV indexes, the heart rate was recorded heartbeat to heartbeat with the young resting in dorsal (prone) position for 30 minutes RESULTS: after Anderson-Darling and Lilliefors tests, the data was deemed non-normal. So, Kruskal-Wallis test of significance was applied for the statistical analysis, level set at (p < 0.01). Principal Component Analysis (PCA) identified two components represented 100% of total variance. The algorithm which applies all three parameters is suggested as the most influential and statistically very significant at the level (p < 0.001); it also elevates the chaotic response CONCLUSION: youth obesity increases the chaotic response. The reasons for the study include quantitative assessment to allow effective dietary, pharmacological or even surgical intervention in the condition.

Risk appraisal by novel chaotic globals to HRV in subjects with malnutrition

The aim of this study is to assess the risk of dynamical diseases in malnourished children. This is achieved by the application of novel chaotic global techniques to the RR-intervals of the electrocardiogram (ECG) in the cohort. Heart Rate Variability (HRV) is an inexpensive and non-invasive tool to measure the autonomic impulses. Here there has been a decrease in chaotic response of HRV. Seventy children were divided into equal groups and the HRV monitored for 20-25 minutes. The Chaos Forward Parameter (CFP) which applies all three chaotic global parameters is suggested to be the most robust algorithm. These three parameters are high spectral entropy (hsEntropy), high spectral detrended fluctuation analysis (hsDFA) and spectral multi-taper method (sMTM)...

O objetivo deste estudo é avaliar o risco de doenças dinâmicas em crianças desnutridas. Isto é feito por meio da aplicação de novas técnicas caóticas globais para os intervalos R-R do ECG. A variabilidade da frequência cardíaca (VFC) é uma ferramenta de baixo custo e não-invasiva que mensura os impulsos autonômicos. Na desnutrição ocorreu uma diminuição na resposta caótica da VFC. Setenta crianças foram divididas em grupos iguais e a VFC foi monitorada por 20 a 25 minutos. O parâmetro caótico avançado (CFP), que utiliza os três parâmetros caóticos globais é o algoritmo mais robusto. Estes três parâmetros são: alta entropia espectral (hsEntropia), análise da alta flutuação depurada espectral (hsDFA) e método espectral multi-taper (sMTM)...