Search for: observational-study
0.004 seconds

    Switching kalman filter based methods for apnea bradycardia detection from ECG signals

    , Article Physiological Measurement ; Volume 36, Issue 9 , 2015 , Pages 1763-1783 ; 09673334 (ISSN) Ghahjaverestan, N. M ; Shamsollahi, M. B ; Ge, D ; Hernandez, A. I ; Sharif University of Technology
    Apnea bradycardia (AB) is an outcome of apnea occurrence in preterm infants and is an observable phenomenon in cardiovascular signals. Early detection of apnea in infants under monitoring is a critical challenge for the early intervention of nurses. In this paper, we introduce two switching Kalman filter (SKF) based methods for AB detection using electrocardiogram (ECG) signal. The first SKF model uses McSharry's ECG dynamical model integrated in two Kalman filter (KF) models trained for normal and AB intervals. Whereas the second SKF model is established by using only the RR sequence extracted from ECG and two AR models to be fitted in normal and AB intervals. In both SKF approaches, a... 

    Young EFL learners’ attitude towards rall: An observational study focusing on motivation, anxiety, and interaction

    , Article 9th International Conference on Social Robotics, ICSR 2017, 22 November 2017 through 24 November 2017 ; Volume 10652 LNAI , 2017 , Pages 252-261 ; 03029743 (ISSN); 9783319700212 (ISBN) Alemi, M ; Meghdari, A ; Haeri, N. S ; Sharif University of Technology
    Springer Verlag  2017
    In this paper we aimed to explore young Iranian EFL learners’ attitude towards Robot Assisted Language Learning (RALL) in an English language classroom. To this end, 19 preschool children ranging from 3 to 6 years old were randomly assigned to a RALL group which had a robot as an assistant to the teacher. Their attitude towards the robot was video recorded for one month, during ten sessions of their English classroom course. Their overall attitude was examined focusing on the three factors of anxiety, motivation and interaction based on human-robot interaction (HRI) theory. The result of this study showed that children’s motivation increased as a result of interacting with the robot and... 

    COVID and nutrition: A machine learning perspective

    , Article Informatics in Medicine Unlocked ; Volume 28 , 2022 ; 23529148 (ISSN) Jafari, N ; Besharati, M. R ; Izadi, M ; Talebpour, A ; Sharif University of Technology
    Elsevier Ltd  2022
    A self-report questionnaire survey was conducted online to collect big data from over 16000 Iranian families (who were the residents of 1000 urban and rural areas of Iran). The resulting data storage contained over 1 M records of data and over 1G records of automatically inferred information. Based on this data storage, a series of machine learning experiments was conducted to investigate the relationship between nutrition and the risk of contracting COVID-19. With highly accurate scores, the findings strongly suggest that foods and water sources containing certain natural bioactive and phytochemical agents may help to reduce the risk of apparent COVID-19 infection. © 2022 The Author(s)  

    Speed/accuracy trade-off between the habitual and the goal-directed processes

    , Article PLoS Computational Biology ; Volume 7, Issue 5 , 2011 ; 1553734X (ISSN) Keramati, M ; Dezfouli, A ; Piray, P ; Sharif University of Technology
    Instrumental responses are hypothesized to be of two kinds: habitual and goal-directed, mediated by the sensorimotor and the associative cortico-basal ganglia circuits, respectively. The existence of the two heterogeneous associative learning mechanisms can be hypothesized to arise from the comparative advantages that they have at different stages of learning. In this paper, we assume that the goal-directed system is behaviourally flexible, but slow in choice selection. The habitual system, in contrast, is fast in responding, but inflexible in adapting its behavioural strategy to new conditions. Based on these assumptions and using the computational theory of reinforcement learning, we... 

    Magnitude, symmetry and attenuation of upper body accelerations during walking in women: The role of age, fall history and walking surface

    , Article Maturitas ; Volume 139 , 2020 , Pages 49-56 Soleimanifar, M ; Mazaheri, M ; van Schooten, K. S ; Asgari, M ; Mosallanezhad, Z ; Salavati, M ; Sedaghat Nejad, E ; Parnianpour, M ; Sharif University of Technology
    Elsevier Ireland Ltd  2020
    Objectives: The present experiment examined the role of age and fall history in upper body accelerations when walking on an even and on an uneven surface. Study design: An observational cross-sectional study. Main outcome measures: The magnitude (root mean square [RMS]), symmetry (harmonic ratio) and attenuation (attenuation coefficient) of upper body accelerations were quantified as primary outcomes; gait spatiotemporal parameters were measured as secondary outcomes. Methods: Twenty young adults (mean ± SD age: 29.00 ± 4.51 yrs), 20 older non-fallers (66.60 ± 5.43 yrs) and 20 older fallers (68.55 ± 4.86 yrs) walked on an even and on an uneven surface, while wearing four accelerometers... 

    Some natural hypomethylating agents in food, water and environment are against distribution and risks of COVID-19 pandemic: Results of a big-data research

    , Article Avicenna Journal of Phytomedicine ; Volume 12, Issue 3 , 2022 , Pages 309-324 ; 22287930 (ISSN) Besharati, M. R ; Izadi, M ; Talebpour, A ; Sharif University of Technology
    Mashhad University of Medical Sciences  2022
    Objective: This study analyzes the effects of lifestyle, nutrition, and diets on the status and risks of apparent (symptomatic) COVID-19 infection in Iranian families. Materials and Methods: A relatively extensive questionnaire survey was conducted on more than 20,000 Iranian families (residing in more than 1000 different urban and rural areas in the Islamic Republic of Iran) to collect the big data of COVID-19 and develop a lifestyle dataset. The collected big data included the records of lifestyle effects (e.g. nutrition, water consumption resources, physical exercise, smoking, age, gender, health and disease factors, etc.) on the status of COVID-19 infection in families (i.e. residents of... 

    MicroRNAs 29, 150, 155, 223 level and their relation to viral and immunological markers in HIV-1 infected naive patients

    , Article Future Virology ; Volume 13, Issue 9 , 2018 , Pages 637-645 ; 17460794 (ISSN) Moghoofei, M ; Bokharaei Salim, F ; Esghaei, M ; Keyvani, H ; Honardoost, M ; Mostafaei, S ; Ghasemi, A ; Tavakoli, A ; Javanmard, D ; Babaei, F ; Garshasbi, S ; Monavari, S. H ; Sharif University of Technology
    Aim: The aim of this study was to assess the relationship between microRNAs and viral and immunological markers in HIV-1 infection. Materials & methods: The expression level of miRNAs was evaluated in 60 HIV-1 patients and 20 healthy controls using real-time PCR assays. Results: The results showed that among all miRNAs, miR-29 and miR-150 were significantly downregulated in HIV-1 patients compared with healthy controls, while miR-155 and miR-223 were significantly upregulated compared with healthy controls (p < 0.001 for all comparisons). Conclusion: The mentioned miRNAs seem to influence the clinical progression of HIV-1 infection in naive patients. Moreover, determining the profiles of...