EEG Dimension Reduction in Motor Imagery-based BCI Approach
Dmitry Lazurenko,
Valery Kiroy,
Dmitry Shaposhnikov
Issue:
Volume 7, Issue 1, June 2022
Pages:
1-7
Received:
7 December 2021
Accepted:
4 January 2022
Published:
12 January 2022
DOI:
10.11648/j.aap.20220701.11
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Abstract: Although a significant number of studies have been devoted to the investigation of the electrographic correlates and neurophysiological mechanisms of voluntary movement and motor imagery-related brain activity, there is a question on which EEG characteristics reflect its content. Considering that motor imagery is a complex cognitive process which requires coordinated activity of a number of cortical structures of the hemispheres, the EEG dimension reduction problems were studied. The values were recorded from 14 channels in eight subjects in the task of voluntary movement execution and motor imagery activity. The principal component analysis has shown that the orthogonal transformation of the EEG channels has formed of 3 components, sufficient to describe a multidimensional brain pattern. The description of invariant EEG patterns of voluntary movements and motor imagery can be performed on the basis of a compressed set of features of the covariance matrix. It has been shown that frontal and central areas as critical brain structures controlling behaviour predominantly participated in the performance of movement execution. Whereas under conditions of motor imagery-related brain activity, the loci remaining in the primary motor cortex were additionally formed in the parieto-occipital associative regions of the brain, with a partial dominance of the right hemisphere. The eigenvectors of target spatio-temporal EEG patterns associated with the movements execution and motor imagery can be used as markers for classification in the BCIs.
Abstract: Although a significant number of studies have been devoted to the investigation of the electrographic correlates and neurophysiological mechanisms of voluntary movement and motor imagery-related brain activity, there is a question on which EEG characteristics reflect its content. Considering that motor imagery is a complex cognitive process which r...
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Acute Blood Pressure and Pulse Rate Response to Isometric Handgrip Exercise at 30% Maximum Voluntary Contraction in Prehypertensive Subjects
Ogbutor Udoji Godsday,
Nwangwa Eze Kingsley,
Agbonifo Chijiokwu Ejime,
Nwabueze Zuwaira,
Ephraim Chukwuemeka,
Nwogueze Bartholomew Chukwuebuka,
Nkemakonam Ezeonu,
Ugoeze Francis Chinedu,
Ezunu Emmanuel,
Awele Nworah,
Igweh John Chukwuma
Issue:
Volume 7, Issue 1, June 2022
Pages:
8-14
Received:
24 January 2022
Accepted:
13 February 2022
Published:
9 March 2022
DOI:
10.11648/j.aap.20220701.12
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Abstract: Public health promotion and recommendation of physical exercise by agencies and organizations have not favourably considered isometric exercise in contrast with dynamic exercise. This reluctance has been premised on the fear that isometric exercise could be hazardous due to the striking acute increase in the blood pressure. Therefore, this study examined the acute effects of isometric handgrip exercise at 30% maximum voluntary contraction (MVC) on the blood pressure and pulse rates in prehypertensives. One hundred and ninety two (n=192) middle aged (30-50years) sedentary prehypertensive subjects, were enrolled into the study. The subjects completed two bouts of isometric handgrip exercise at 30% MVC and their blood pressure and pulse rates were measured within 5minutes and 10 minutes post-exercise. Following the completion of the study, result shows an acute (5minutes) blood pressure and pulse rate increase of 8.9mmHg, 6.96mmHg and 9.57b/min in the systolic and diastolic blood pressure and pulse rate respectively which was statistically significant at P<0.05. On the other hand the rise in blood pressure and pulse rates rapidly dropped to -0.91±1.73mmHg, 2.06±1.15mmHg and 5.06±2.37b/min respectively within 10 minutes post exercise which was statistically significant at P<0.05. In summary, this study has established that the blood pressure response at to isometric handgrip exercise at 30%MVC comprises of an immediate rise in blood pressure and pulse rate but rapidly returns to pre exercise levels within ten minutes post-exercise. The acute significant rise in the blood pressure and pulse rates following isometric handgrip exercise at 30%MVC requires that caution should be applied in its application in hypertensive patient’s population but the rapid decline to pre training levels could be an added advantage.
Abstract: Public health promotion and recommendation of physical exercise by agencies and organizations have not favourably considered isometric exercise in contrast with dynamic exercise. This reluctance has been premised on the fear that isometric exercise could be hazardous due to the striking acute increase in the blood pressure. Therefore, this study ex...
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Varied Fasting Periods Moderate Intestinal Glucose Absorption in Male Wistar Rats
Odukanmi Olugbenga Adeola
Issue:
Volume 7, Issue 1, June 2022
Pages:
15-21
Received:
1 April 2022
Accepted:
18 April 2022
Published:
26 April 2022
DOI:
10.11648/j.aap.20220701.13
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Abstract: Fasting is abstaining from food and/or drinking water for a while, observed majorly for medical or spiritual purposes. The effect of varied fasting durations on intestinal glucose uptake was investigated in this study. Forty male Wistar rats, weighing between 100 and 120 g were used. They were randomly assigned into four groups (n=10 per group), Group 1: control (no fast), groups 2, 3, and 4, were fasted for 24, 48, and 72 hours respectively. Five rats each from the groups were used for the in vivo and ex vivo studies. The fasting blood glucose (FBG) level, intestinal glucose uptake (in vivo and ex vivo methods), and intestinal luminal electrolytes for sodium and potassium were determined. The FBG and the intestinal glucose uptake of the rats were determined by the glucose oxidase method. Data were represented as Mean±SEM and analysis was done by one-way ANOVA using GraphPad Prism version 7.0. Results were considered significant at p<0.05. The FBG (mg/dl) in the 24H (62.00±5.17), 48H (51.80±4.48) and 72H (75.00±8.32) groups decreased significantly compared with the control (103.80±4.35). Intestinal glucose concentration (mg/dl/g tissue) in vivo method decrease significantly in the 48H (11.21±0.38) and 72H (10.39±0.77) groups compared to the control (15.02±0.51) respectively in the jejunum and implied increased glucose absorption. Luminal glucose concentration (mg/dl/g tissue) of the fasted 48H group (27.92±0.66) increased significantly compared to control (13.86±0.75), 24H (17.84±0.65), and 72H (13.56±1.00). The ileum luminal glucose concentration (mg/dl/g tissue) decreased significantly in 48H (11.11±0.63) and 72H (11.02±0.56) groups compared to the control (13.86±0.59). In the assessment of varied fasting durations in vitro, intestinal glucose absorption increased while potassium concentration increased and sodium concentration decreased within the mucosa end. The results suggest that varied fasting periods increase intestinal glucose absorption. Conclusively, this study reported an overall increase in intestinal glucose absorption at both the jejunum and ileum ends after 48 and 72 h of continuous fasting.
Abstract: Fasting is abstaining from food and/or drinking water for a while, observed majorly for medical or spiritual purposes. The effect of varied fasting durations on intestinal glucose uptake was investigated in this study. Forty male Wistar rats, weighing between 100 and 120 g were used. They were randomly assigned into four groups (n=10 per group), Gr...
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