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Research suggests that massive open online course (MOOC) students prefer to study in groups, and that social facilitation within the study groups may render the learning of difficult concepts a pleasing experience. We report on a longitudinal study that investigates how co-located study groups watch and study MOOC videos together. The study was conducted with on-campus flipped classroom students. Our subjects reported an overall high satisfaction with the study group style. The research reveals that students like to stay synchronized in the group while watching MOOC videos. However, they have to find a balance between synchronization, video interaction, and the amount of conversation. Watching MOOCs on a shared display addresses the need of synchronicity, and the distribution of control can increase the video interactivities.

Introduction Low-frequency noise (LFN) is hazardous to hearing. Long-term exposure to LFN may lead to vibroacoustic disease (VAD), which not only affects a specific organ but the physiological function of entire systems, such as the auditory, phonatory, respiratory, and cardiac systems. Moreover, VAD may lead to many psychological problems and hence affect the quality of life. Objective To investigate the adverse effects of LFN on hearing, acoustic and perceptual correlates of the voice, blood pressure, cardiac rate, and anxiety level. Method A total of 20 subjects exposed to LFN and 20 not exposed to LFN were included, and a detailed case history was recorded. The patients were submitted to pure tone audiometry, otoscopic examination, acoustic and perceptual analyses of the voice, maximum phonation time, and an assessment of the s/z ratio. We also assessed blood pressure, and the results of a voice-related quality of life questionnaire and of the Hamilton anxiety rating scale. Results The results indicate that LFN had an adverse impact on the high-frequency threshold. The present study found a significant difference in shimmer and harmonics-to-noise ratio (HNR) values. Few subjects had high blood pressure and showed the sign of anxiety on the Hamilton anxiety rating scale. Conclusion Low-frequency noise has adverse effects on entire systems of the body and causes many psychological issues, which, in turn negatively affect quality of life. [ABSTRACT FROM AUTHOR]

Background Traumatic cervical spinal cord injury (TCSCI) is a disabling condition with uncertain neurologic recovery. Clinical and preclinical studies have suggested early surgical decompression and other measures of neuroprotection improve neurologic outcome. We investigated the role of intramedullary lesion length (IMLL) on preoperative magnetic resonance imaging (MRI) and the effect of early cervical decompressive surgery on ASIA impairment scale (AIS) grade improvement following TCSCI. Methods In this retrospective study, we investigated 34 TCSCI patients who were admitted over a 12-year period, from January 1, 2008 to January 31, 2020. We studied the patient demographics, mode of injury, IMLL and timing of surgical decompression. The IMLL is defined as the total length of edema and contusion/hemorrhage within the cord. Short tau inversion recovery (STIR) sequences or T2-weighted MR imaging with fat saturation increases the clarity of edema and depicts abnormalities in the spinal cord. All patients included had confirmed adequate spinal cord decompression with cervical fixation and a follow-up of at least 6 months. Results Of the 34 patients, 16 patients were operated on within 24 hours (early surgery group) and 18 patients were operated on more than 24 hours after trauma (delayed surgery group). In the early surgery group, 13 (81.3%) patients had improvement of at least one AIS grade, whereas in the delayed surgery group, AIS grade improvement was seen in only in 8 (44.5%) patients (early vs. late surgery; odds ratio [OR] = 1.828; 95% confidence interval [CI]: 1.036–3.225). In multivariate regression analysis coefficients, the timing of surgery and intramedullary edema length on MRI were the most significant factors in improving the AIS grade following cervical SCI. Timing of surgery as a unique variance predicted AIS grade improvement significantly (p < 0.001). The mean IMLL was 41.47 mm (standard deviation [SD]: 18.35; range: 20–87 mm). IMLL was a predictor of AIS grade improvement on long-term outcome in bivariate analysis (p < 0.001). This study suggests that patients who had IMLL of less than 30 mm had a better chance of grade conversion irrespective of the timing of surgery. Patients with an IMLL of 31 to 60 mm had chances of better grade conversion after early surgery. A longer IMLL predicts lack of improvement (p < 0.05). If the IMLL is greater than 61 mm, the probability of nonconversion of AIS grade is higher, even if the patient is operated on within 24 hours of trauma. Conclusion Surgical decompression within 24 hours of trauma and shorter preoperative IMLL are significantly associated with improved neurologic outcome, reflected by better AIS grade improvement at 6 months' follow-up. The IMLL on preoperative MRI can reliably predict outcome after 6 months. The present study suggests that patients have lesser chances of AIS grade improvement when the IMLL is ≥61 mm. [ABSTRACT FROM AUTHOR]

Blockchains have ushered in the next stage in the evolution of the Internet, transitioning us from Web 2.0 to 3.0. However, given the complex nature of this innovative technology and the inability to clearly measure and properly communicate the risks in blockchains, arguably this murkiness has hampered the development, growth, proper regulation, and, ultimately, the true societal beneficial contributions of blockchains. In an attempt to clear the confusion, the authors propose the Johns Hopkins Blockchain Risk Map. The authors present their risk map prototype, their current multidimensional exhibit of risks across the various stakeholders, and their current modest progress with some data on their current risk measures. The authors are attempting to create a safe space whereby blockchain risks are defined, displayed, debated, researched, fine-tuned, standardized, and freely shared. The authors believe that such a platform would be an ideal mechanism for education, networking, and collaboration for the next generation, specifically those who are underrepresented in the current blockchain development community. By increasing the transparency and debating risk issues in a safe academic environment, the authors hope that this risk map will help move blockchain adoption forward and spur more entrepreneurial activity across this industry. In this article, the authors lay down their initial thoughts and current progress and challenges. Although this article is in no way exhaustive, the authors provide several categorizations of blockchain risks: operational, decentralization, security, social sentiment, investment, and systemic, to name a few. [ABSTRACT FROM AUTHOR]