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Student Perceptions of Teacher-Generated Educational Videos Shown in a Korean EFL Classroom
Harrison,Michael Fraser(Harrison,Michael Fraser ) 영상영어교육학회 2023 영상영어교육 (STEM journal) Vol.24 No.1
The purpose of this study was to analyze the perceptions of Korean English as a Foreign Language (EFL) university students toward teacher-generated educational videos and the recommendations they have for improving their effectiveness. While playing short video clips is now common practice in many EFL classes, few teachers choose to generate their own educational videos and little research has been done on how to create effective educational videos for EFL learners. Nine Korean university students participated in this study with qualitative data being collected from a focus group and semi-structured interviews. The videos shown to the students were viewed on the YouTube website during class and were created by their teacher and the author of this paper. The results show that the students find the videos helpful and effective for improving their English, although it is recommended to limit the time spent in class watching videos as students would rather spend time practicing the language. Other opinions and recommendations are grounded in cognitive load theory. The implications of this study suggest that teachers should consider creating their own educational videos and suggestions are made of how to create effective presentations.
Conor James Craig Gouk,Ryan Mark Shulman,Craig Buchan,Michael John Evan Thomas,Fraser James Taylor 대한정형외과학회 2019 Clinics in Orthopedic Surgery Vol.11 No.2
Background: Massive retracted rotator cuff tears represent a therapeutic dilemma, particularly in the young and middle-aged patients who are not appropriate for a reverse total shoulder replacement. Interposition grafting using human dermal allograft offers an alternative treatment. Methods: A retrospective review of all patients who underwent interposition grafting using human dermal allograft between December 2013 and May 2015 for massive rotator cuff tears at our tertiary referral center was performed. Preoperative and 6 month postoperative magnetic resonance imaging (MRI) assessments were performed in all patients, with postoperative graft integrity being the primary outcome measure. Clinical evaluation was performed using the Oxford shoulder score, Constant score, and Disabilities of the Arm, Shoulder and Hand (DASH) score. Results: The mean age at the time of follow-up was 54 years. On MRI, 84% of grafts were seen to have failed at 6 months. Strength was grossly reduced on the operative side when supraspinatus and subscapularis were tested; despite this, Constant score (mean, 48.2) was comparable to that in the previous reports. DASH and Oxford scores were a mean of 24.94 and 37.16, respectively. Conclusions: Based on these results, in particular the MRI findings, we cannot advocate the use of dermal allograft as an interposition graft for the repair of massive rotator cuff tears.
Tetrathiafulvalene Hetero Radical Cation Dimerization in a Redox-Active [2]Catenane
Wang, Cheng,Dyar, Scott M.,Cao, Dennis,Fahrenbach, Albert C.,Horwitz, Noah,Colvin, Michael T.,Carmieli, Raanan,Stern, Charlotte L.,Dey, Sanjeev K.,Wasielewski, Michael R.,Stoddart, J. Fraser American Chemical Society 2012 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.134 No.46
<P>The electronic properties of tetrathiafulvalene (TTF) can be tuned by attaching electron-donating or electron-withdrawing substituents. An electron-rich macrocyclic polyether containing two TTF units of different constitutions, namely 4,4′-bis(hydroxymethyl)tetrathiafulvalene (OTTFO) and 4,4′-bisthiotetrathiafulvalene (STTFS), has been synthesized. On two-electron oxidation, a hetero radical dimer is formed between OTTFO<SUP>•+</SUP> and STTFS<SUP>•+</SUP>. The redox behavior of the macrocyclic polyether has been investigated by electrochemical techniques and UV–vis and electron paramagnetic resonance (EPR) spectroscopies. The [2]catenane in which the macrocyclic polyether is mechanically interlocked with the cyclobis(paraquat-<I>p</I>-phenylene) (CBPQT<SUP>4+</SUP>) ring has also been prepared using template-directed protocols. In the case of the [2]catenane, the formation of the TTF hetero radical dimer is prevented sterically by the CBPQT<SUP>4+</SUP> ring. After a one-electron oxidation, a 70:30 ratio of OTTFO<SUP>•+</SUP> to STTFS<SUP>•+</SUP> is present at equilibrium, and, as a result, two translational isomers of the [2]catenane associated with these electronically different isomeric states transpire. EPR titration spectroscopy and simulations reveal that the radical states of the two constitutionally different TTF units in the [2]catenane still experience long-range electronic intramolecular coupling interactions, despite the presence of the CBPQT<SUP>4+</SUP> ring, when one or both of them are oxidized to the radical cationic state. These findings in the case of both the free macrocyclic polyether and the [2]catenane have led to a deeper fundamental understanding of the mechanism of radical cation dimer formation between constitutionally different TTF units.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2012/jacsat.2012.134.issue-46/ja307577t/production/images/medium/ja-2012-07577t_0013.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja307577t'>ACS Electronic Supporting Info</A></P>
Stimulated Release of Size‐Selected Cargos in Succession from Mesoporous Silica Nanoparticles
Wang, Cheng,Li, Zongxi,Cao, Dennis,Zhao, Yan‐,Li,Gaines, Justin W.,Bozdemir, O. Altan,Ambrogio, Michael W.,Frasconi, Marco,Botros, Youssry Y.,Zink, Jeffrey I.,Stoddart, J. Fraser WILEY‐VCH Verlag 2012 Angewandte Chemie Vol.124 No.22
<P><B>Zwei Fliegen mit einer Klappe</B>: Die kovalente Bindung von β‐Cyclodextrin (gelb; siehe Bild) an mesoporöse Siliciumdioxid‐Nanopartikel (MSNs) ergibt ein duales Freisetzungssystem, das mit unterschiedlich großen Wirkstoffen (blaue und rote Kugeln) beladen werden kann, die sich auf verschiedene Stimuli hin nacheinander freisetzen lassen. Die kleineren Moleküle werden durch Absenken des pH‐Wertes freigesetzt, die größeren nach Abspaltung der Cyclodextrine von der MSN‐Oberfläche.</P>