Learning Together in Public and in Private: Exploring Learner Interactions and Engagement in a Blended-Platform MOOC Environment

With the growing popularity of connectivist MOOCs, the aim of facilitators has increasingly shifted from helping students meet completion-oriented goals to encouraging meaningful engagement among participants. In this paper, we study the relationship between platform of engagement and learner participation, controlling for relevant demographic factors of participants including gender, age, and level of education attained. Our study employs four distinct measures of participatory engagement: autonomous learning, knowledge reproduction, information networking, and scholarly engagement. We find that on the public platform of Twitter, participants were more likely to exhibit meaningful engagement patterns across all measures studied than they were on the closed EdX class discussion space

Does larger tumor volume explain the higher prostate specific antigen levels in black men with prostate cancer—Results from the SEARCH database

OBJECTIVES: To assess whether larger tumor volume in black men explains higher presurgical PSA levels versus white men with prostate cancer. METHODS: We retrospectively analyzed 1904 men from the Shared Equal Access Regional Cancer Hospital database who underwent radical prostatectomy from 1990 to 2013. Geometric mean of tumor volume and preoperative PSA for each race were estimated from multivariable linear regression models. RESULTS: There were 1104 (58%) white men and 800 (42%) black men. Black men were younger (60.2 vs. 62.9years, p<0.001) had a higher PSA (6.7 vs. 6.0ng/mL, p<0.001), more positive margins (47 vs. 38%, p<0.001), and seminal vesicle invasion (13 vs. 9%, p=0.007). White patients had higher clinical stage (p<0.001) and greater median tumor volume (6.0 vs. 5.3gm, p=0.011). After multivariable adjustment (except for PSA), white men had smaller mean tumor volumes (5.2 vs. 5.8gm, p=0.011). When further adjusted for PSA, there was no racial difference in mean tumor volume (p=0.34). After multivariable adjustment, black men had higher mean PSAs vs. white men (7.5 vs. 6.1ng/mL, p<0.001). Results were similar after further adjusting for tumor volume: black men had 16% higher mean PSAs versus white men (7.4 vs. 6.2ng/mL, p<0.001). CONCLUSIONS: In this study of men undergoing radical prostatectomy at multiple equal access medical centers, racial differences in tumor volume did not explain higher presurgical PSA levels in black versus white men. The exact reason for higher PSA values in black men remains unclear

Carbon Fiber Reinforced Polymer (CFRP) Composite Materials, Their Characteristic Properties, Industrial Application Areas and Their Machinability

Technology-oriented applications are becoming more important in today’s world and the use of technological processes continues to grow rapidly, day by day. Because of the advantages offered by composite materials, there is a great deal of interest in this material group in various industrial applications. Composite materials continue to develop at a great pace in parallel with the developments in metallic, ceramic and polymeric materials. Therefore, composite materials have found wide usage in engineering materials in recent years. In this material group, carbon fiber reinforced polymer (CFRP) composite materials, from the advanced composite material class, are commonly preferred in strategic applications due to their outstanding features such as high load-carrying capacity and low density. In this study, the production, characteristics and industrial usages of CFRP composite materials, milling and drilling operations carried out on them are presented along with current technology-oriented applications. © Springer Nature Switzerland AG 2020