DOAJ (DOAJ: Directory of Open Access Journals), Jun 1, 2001
Neste trabalho apresentamos uma avaliacao da nossa experiencia com o uso da estrategia de "a... more Neste trabalho apresentamos uma avaliacao da nossa experiencia com o uso da estrategia de "aprendizagem assistida por computador". Usamos uma simulacao em computador no ensino de fisiologia cardiovascular, em uma aula pratica sobre regulacao da pressao arteria. Um questionario avaliando a atitude dos alunos frente ao uso de uma simulacao como um instrumento didatico foi aplicado antes e apos o uso da simulacao. Nossos resultados mostraram que a simulacao foi positivamente avaliada pelo estudante como um efetivo instrumento para ensino. O potencial de uso da estrategia de aprendizagem assistida por computador e discutida com o resultados
Estrogen levels have been reported to influence cognitive performance measures. Notably, cognitio... more Estrogen levels have been reported to influence cognitive performance measures. Notably, cognition is also subjected to the time stamp phenomenon, in which optimal performance occurs when the time of testing matches the time of training, highlighting the importance of carefully examining external cues in the synchronization of consciously controlled brain activity. The current study tested intact, sham-operated and ovariectomized Wistar rats to investigate the time stamp phenomenon at different phases of the estrous cycle to control for internal hormonally regulated time-dependent neuroendocrine activity that may influence learning outcome measures. Rats were trained and tested in an object recognition task, at matching Zeitgeber Time (ZT14–ZT14) or nonmatching times (ZT14–ZT18), during proestrus or estrus phases. Intact rats tested in the estrus phase significantly exhibited increased exploration of the new object, but only when training and testing times matched. Contrastingly, intact rats tested in proestrus exhibited increased exploration of the new object at both times tested. Moreover, the ovariectomized rats resulted in an abolished preference selectivity for new objects, even when the testing was performed at the same time as the training. Finally, the sham-operated rats tested in proestrus also exhibited an increased exploration of the new object at both times tested. Taken together, these results suggest that high estrogen levels during the proestrus phase in rats can facilitate object recognition.
We analyzed the effect of dissociation of the circadian rhythm of locomotor activity on the perfo... more We analyzed the effect of dissociation of the circadian rhythm of locomotor activity on the performance in two memory tasks in rats. One group of animals was maintained in a normal 24 h light-dark cycle of 12:12 (T24 group, control). A second group was housed in a 22 h cycle of 11:11 (T22 group, experimental), a condition which is known to produce dissociation of the circadian rhythm of locomotor activity in two components. Both groups were tested on two memory tasks: passive avoidance and object recognition. An additional control group, kept under constant darkness (DD group), was used for a passive avoidance task. Testing occurred 30 min (short-term memory--STM) and 24 h (T24 and DD group) or 22 h (T22 group) (long-term memory--LTM) after training. The T22 group showed impairment on the passive avoidance task (STM and LTM) compared with the T24 and DD groups. On the object recognition task, the T22 and T24 groups performed similarly in all the sessions. In conclusion, circadian rhythm dissociation induced a performance deficit in the passive avoidance task but had no effect on the object recognition task. We suggest that dissociation of the circadian rhythm of locomotor activity may selectively affect some emotional component related to fear and risk evaluation.
2020 IEEE International Instrumentation and Measurement Technology Conference (I2MTC)
The exposure to colored light with different wavelengths has proved to affect the physiological f... more The exposure to colored light with different wavelengths has proved to affect the physiological functions of the human body. To test such influence, this work was focused on heart rate variability (HRV) analysis associated with different colored light exposure of healthy volunteers. A Photoplethysmography (PPG) wireless sensor network node was employed to acquire information about the cardiac activity, as it proves to be a more convenient and less intrusive method as electrocardiography (ECG). A small group of healthy volunteers were exposed to 10 minutes of blue and red light, preceded and followed by 5 minutes of dark lighting conditions. HRV was acquired during the last 5 minutes of each colored illumination period. The HRV analysis was based on time-domain variables, frequency-domain variables and fractal (nonlinear) analysis. The experimental results from this study show that PPG can be considered as a reliable method to study HRV. The exposure to different colored light conducted to HRV variations that characterize the autonomous nervous system balance. Experimental results obtained for volunteers exposed to different illumination conditions are also included in the paper.
2020 International Conference and Exposition on Electrical And Power Engineering (EPE)
The article presents a heart rate variability (HRV) monitoring system for the detection of attent... more The article presents a heart rate variability (HRV) monitoring system for the detection of attention status during learning activity. Developing an embedded system, the ECG and PPG signals are acquired simultaneously. Acquired signal primary including peak detection was applied to extract information about peak to peak time intervals that is used to calculate the HR abut also HRV. The primary processing data are sent in real time to a database in the cloud. Subsequently, HRV is analysed based on Matlab implemented algorithms considering time and frequency domains as so as non-linear measures. Several tests were carried out and the recorded results were analysed as the starting point to classify situations that capture the state of attention.
Alterations in the circadian rhythms are present in the presymptomatic phase of Alzheimer’s disea... more Alterations in the circadian rhythms are present in the presymptomatic phase of Alzheimer’s disease (AD), possibly contributing to its pathogenesis. However, it is unknown whether such alterations could be associated with worse outcomes once the individuals are diagnosed with the disease. We aimed to evaluate the association between the rest‐activity rhythm and AD‐related outcomes in patients with mild‐moderate AD.
DOAJ (DOAJ: Directory of Open Access Journals), Jun 1, 2001
Neste trabalho apresentamos uma avaliacao da nossa experiencia com o uso da estrategia de "a... more Neste trabalho apresentamos uma avaliacao da nossa experiencia com o uso da estrategia de "aprendizagem assistida por computador". Usamos uma simulacao em computador no ensino de fisiologia cardiovascular, em uma aula pratica sobre regulacao da pressao arteria. Um questionario avaliando a atitude dos alunos frente ao uso de uma simulacao como um instrumento didatico foi aplicado antes e apos o uso da simulacao. Nossos resultados mostraram que a simulacao foi positivamente avaliada pelo estudante como um efetivo instrumento para ensino. O potencial de uso da estrategia de aprendizagem assistida por computador e discutida com o resultados
Estrogen levels have been reported to influence cognitive performance measures. Notably, cognitio... more Estrogen levels have been reported to influence cognitive performance measures. Notably, cognition is also subjected to the time stamp phenomenon, in which optimal performance occurs when the time of testing matches the time of training, highlighting the importance of carefully examining external cues in the synchronization of consciously controlled brain activity. The current study tested intact, sham-operated and ovariectomized Wistar rats to investigate the time stamp phenomenon at different phases of the estrous cycle to control for internal hormonally regulated time-dependent neuroendocrine activity that may influence learning outcome measures. Rats were trained and tested in an object recognition task, at matching Zeitgeber Time (ZT14–ZT14) or nonmatching times (ZT14–ZT18), during proestrus or estrus phases. Intact rats tested in the estrus phase significantly exhibited increased exploration of the new object, but only when training and testing times matched. Contrastingly, intact rats tested in proestrus exhibited increased exploration of the new object at both times tested. Moreover, the ovariectomized rats resulted in an abolished preference selectivity for new objects, even when the testing was performed at the same time as the training. Finally, the sham-operated rats tested in proestrus also exhibited an increased exploration of the new object at both times tested. Taken together, these results suggest that high estrogen levels during the proestrus phase in rats can facilitate object recognition.
We analyzed the effect of dissociation of the circadian rhythm of locomotor activity on the perfo... more We analyzed the effect of dissociation of the circadian rhythm of locomotor activity on the performance in two memory tasks in rats. One group of animals was maintained in a normal 24 h light-dark cycle of 12:12 (T24 group, control). A second group was housed in a 22 h cycle of 11:11 (T22 group, experimental), a condition which is known to produce dissociation of the circadian rhythm of locomotor activity in two components. Both groups were tested on two memory tasks: passive avoidance and object recognition. An additional control group, kept under constant darkness (DD group), was used for a passive avoidance task. Testing occurred 30 min (short-term memory--STM) and 24 h (T24 and DD group) or 22 h (T22 group) (long-term memory--LTM) after training. The T22 group showed impairment on the passive avoidance task (STM and LTM) compared with the T24 and DD groups. On the object recognition task, the T22 and T24 groups performed similarly in all the sessions. In conclusion, circadian rhythm dissociation induced a performance deficit in the passive avoidance task but had no effect on the object recognition task. We suggest that dissociation of the circadian rhythm of locomotor activity may selectively affect some emotional component related to fear and risk evaluation.
2020 IEEE International Instrumentation and Measurement Technology Conference (I2MTC)
The exposure to colored light with different wavelengths has proved to affect the physiological f... more The exposure to colored light with different wavelengths has proved to affect the physiological functions of the human body. To test such influence, this work was focused on heart rate variability (HRV) analysis associated with different colored light exposure of healthy volunteers. A Photoplethysmography (PPG) wireless sensor network node was employed to acquire information about the cardiac activity, as it proves to be a more convenient and less intrusive method as electrocardiography (ECG). A small group of healthy volunteers were exposed to 10 minutes of blue and red light, preceded and followed by 5 minutes of dark lighting conditions. HRV was acquired during the last 5 minutes of each colored illumination period. The HRV analysis was based on time-domain variables, frequency-domain variables and fractal (nonlinear) analysis. The experimental results from this study show that PPG can be considered as a reliable method to study HRV. The exposure to different colored light conducted to HRV variations that characterize the autonomous nervous system balance. Experimental results obtained for volunteers exposed to different illumination conditions are also included in the paper.
2020 International Conference and Exposition on Electrical And Power Engineering (EPE)
The article presents a heart rate variability (HRV) monitoring system for the detection of attent... more The article presents a heart rate variability (HRV) monitoring system for the detection of attention status during learning activity. Developing an embedded system, the ECG and PPG signals are acquired simultaneously. Acquired signal primary including peak detection was applied to extract information about peak to peak time intervals that is used to calculate the HR abut also HRV. The primary processing data are sent in real time to a database in the cloud. Subsequently, HRV is analysed based on Matlab implemented algorithms considering time and frequency domains as so as non-linear measures. Several tests were carried out and the recorded results were analysed as the starting point to classify situations that capture the state of attention.
Alterations in the circadian rhythms are present in the presymptomatic phase of Alzheimer’s disea... more Alterations in the circadian rhythms are present in the presymptomatic phase of Alzheimer’s disease (AD), possibly contributing to its pathogenesis. However, it is unknown whether such alterations could be associated with worse outcomes once the individuals are diagnosed with the disease. We aimed to evaluate the association between the rest‐activity rhythm and AD‐related outcomes in patients with mild‐moderate AD.
Uploads
Papers by JOHN ARAUJO