Retraction Note: Distance learning impact on the English language teaching during COVID-19.

[This retracts the article DOI: 10.1007/s10639-021-10588-y.].

Distance learning impact on the English language teaching during COVID-19.

These days, distance learning has almost completely replaced traditional teaching methods due to the COVID-19 pandemic and the introduction of quarantine measures. A sharp rise in interest in distance learning methodology has raised a number of new questions and challenges. This research examines changes in the training process and cognitive abilities and academic performance during the coronavirus pandemic. Students of the I.M. Sechenov University and Al Ain University were surveyed (103) during classroom and distance English learning before and during the COVID-19. Three samples of the average values of the respondents' self-assessment of academic performance, cognitive abilities (namely concentration and memory), progress in performing oral assignments, progress in performing written assignments, ability to absorb information while reading and by ear; general health condition during the training and were obtained and tested for the Gaussian distribution law compliance. All of the rates studied fell during distance learning during a pandemic compared to distance learning outside a pandemic. However, it should be noted that they still turned out to be higher than the marks obtained in classroom teaching. Students were interviewed for possible factors influencing the reviewed teaching modes effectiveness (the survey showed that these factors are an increase in the amount of leisure time, ability to take breaks more often, more comfortable learning environment, no need to spend time on the road to the university).

Point Mutations of Nicotinic Receptor α1 Subunit Reveal New Molecular Features of G153S Slow-Channel Myasthenia.

Slow-channel congenital myasthenic syndromes (SCCMSs) are rare genetic diseases caused by mutations in muscle nicotinic acetylcholine receptor (nAChR) subunits. Most of the known SCCMS-associated mutations localize at the transmembrane region near the ion pore. Only two SCCMS point mutations are at the extracellular domains near the acetylcholine binding site, α1(G153S) being one of them. In this work, a combination of molecular dynamics, targeted mutagenesis, fluorescent Ca2+ imaging and patch-clamp electrophysiology has been applied to G153S mutant muscle nAChR to investigate the role of hydrogen bonds formed by Ser 153 with C-loop residues near the acetylcholine-binding site. Introduction of L199T mutation to the C-loop in the vicinity of Ser 153 changed hydrogen bonds distribution, decreased acetylcholine potency (EC50 2607 vs. 146 nM) of the double mutant and decay kinetics of acetylcholine-evoked cytoplasmic Ca2+ rise (τ 14.2 ± 0.3 vs. 34.0 ± 0.4 s). These results shed light on molecular mechanisms of nAChR activation-desensitization and on the involvement of such mechanisms in channelopathy genesis.