Psychology - Publication4 Publications found
Heart Rate Variability: A Longitudinal Comparison of Commercial Devices for Individual and Group Stress-Response
Authors: Kaela Hierholzer , Robert Briggs , Michael Tolston , Nicholas Mackowski , Jason Eckerle , Maegan O’Connor , Kristyn Barrett , Roger Smith , Adam Strang
The collection of heart rate variability (HRV) for health and performance observations have become prominent. However, each wearable device has proprietary algorithms that govern methods and timing of HRV capture and subsequent analysis. The purpose of this study was to evaluate HRV metrics taken from three, commonly used commercial wearables, and identify reliability and relationships to one another over time. Methods: Twenty-five subjects (18 males; 7 females) with ages ranging from 23 to 41 years (32.70 ± 4.65 years) were included in this study. These subjects were participants in a 12-week exercise intervention study. Each subject was equipped with a Whoop Strap (v2.0), the Garmin Fenix 5 Smartwatch and chest strap, and the Omegawave chest strap and sensor. Statistical Analysis: Between and within-subject correlations were calculated as well as average correlations, descriptive and inferential statistics, and the resultant z-score, which was transformed back into a correlation. Intraclass correlation coefficients (ICC) were calculated. Finally, linear mixed models were used to evaluate trends in HRV. Results: Within-subject correlations (0.24 ± 0.27) were lower than between-subjects correlations (0.54 ± 0.43), t (35) = -4.02, p < 0.001. Garmin HRV Stress, Whoop RMSSD, Omegawave SDNN, and Omegawave RMSSD yielded an ICC between 0.65 and 0.75. Garmin All-day stress, Garmin prior all-day stress, and Omegawave LF/HF yielded an ICC of 0.30 and 0.37. To test the effects of day of the week on HRV, we fitted linear mixed models to HRV metrics from three of the identified communities related to ICC: Omegawave RMSSD (moderate to high ICC), Omegawave LF/HF (low to moderate ICC), and Whoop recovery score (very low ICC). There was a main effect of gender on Omegawave RMSSD (p = 0.020) and a negative effect of day of the week (p = 0.030). Day of the week was the only significant predictor of Whoop recovery score (p < 0.001). Conclusion: The correlations of HRV values remain more consistent when assessed at similar times of the day, rather than being device dependent. Regardless of which wearable device is considered, HRV measures should be collected at a specific time each day for the best reliability. When creating an individualized or group exercise program, the human performance specialist should be aware that fatigue may become increasingly evident during the course of each week (e.g. individuals demonstrably fatigued by Friday may exhibit physiological indicators of relative recovery by Monday).
Optimization of a High Capacity Industrial Bar Press for Jatropha Curcas Oil Extraction
Authors: Moussa Abdoul-Aziz , Sidibe Sadio Sayon , Ouedraogo Abdoulaye , Ouedraogo Emmanuel , Ousmane Moctar , Coulibaly Ousmane
This study allowed us to achieve the optimal yield for the extraction of Jatropha Curcas oil from the main operating variables of an industrial press. We used an industrial bar press with a large extraction capacity to carry out this work. Two interesting and indicative parameters on the influence of the efficiency of the press have been analyzed, namely the number of steps of screw and the no-load temperature on the efficiency, the temperatures of the screw, oil and cake, the flow rate of the press, the power, the specific mechanical energy of the press. The best result of 31.09%, which corresponds to the maximum recovery rate of 76.92%, was obtained with the highest number of steps of screw and the highest no-load temperature. The influence of the no-load temperature of the screw on the stability of the press has also been highlighted. The screw, the oil and the cake temperatures stabilize when the no-load temperature is greater than or equal to 100°C. The study of operating variables shows their role on the specific mechanical energy. Indeed, the increase in the number of steps of screw from 4 to 6 results in a decrease in seed flow and increase in power leading to an increase in the specific mechanical energy from 34.01 to 49.83 Wh/kg.
Psychiatrists' Perspectives on the Indicators of Transmission of Anxiety from Parents to Their Infants by Using the Grounded Theory
Authors: Izzeldeen Daoud Mahmoud Shehadeh , Ahmad Mahmood Ahmad Kharabsha
The current research seeks to explore and generate scientific indications about diagnosis, challenges and future suggestions from psychiatrists' point of view for the possibility of transmitting anxiety from parents to their children using the Grounded Theory. To achieve these goals, the researchers used the grounded theory approach as one of the qualitative research designs and analyzed the data collected from (11) specialized psychiatrists at the National Center for Psychiatry in the Hashemite Kingdom of Jordan through structured and semi-structured interviews. The results of interviews with psychiatrists revealed the presence of four developed categories or concepts, the first developed concept “scientific indicators for diagnosing the possibility of transmission of anxiety from the psychiatrist’s point of view,” the second developed concept “the challenges facing the psychiatrist in diagnosing the possibility of transmission of anxiety,” and the third developed concept. Solutions: future prospects for the psychiatrist to prevent the possibility of anxiety transmission” and finally, the fourth developed concept “important aspects of the psychiatrist’s focus on preventing the possibility of anxiety transmission.” From parents to their children and to prevent them in the future, and that this process is difficult due to the multiple sources of anxiety and their continuous interaction (environmental indicators, genetic indicators), and therefore it must face challenges, which need future follow-up, in order to reduce this possibility and prevent it in the future. The results of the current research, we need to pay attention to focusing on the prevention aspect by preparing for a comprehensive integrated plan in the system Health care for the Hashemite Kingdom of Jordan (considering the results of this current research) to prevent the transmission of anxiety in the future.