A Functional Analysis of EFL Students' Discourse in the Social Practice of Learning to Play a Board Game

How do second language (L2) students learn a social practice in their target language? This paper reports on some of the findings of a qualitative study that took a sociocultural approach (e.g., Bruner, 1983; Rogoff, 1990; Schieffelin & Ochs, 1986) to examine how a group of five EFL students learned the social practice of board gaming. A social practice theory analysis (Mohan, 2007) showed that the students worked together to help each other participate in the game and to create a shared understanding of its rules and procedures, revealing how action and reflection discourses were woven together. The analysis also illustrated how the students as active agents altered one of the rules of the game as well as how a relatively novice player, after receiving assistance from more experienced players and observing other players’ actions, assumed a more active role as the play progressed. These findings highlight the important co-construction of actions, roles, and understanding that takes place through L2 collaborative discourse in learning to play a game

Oligopeptides production by a method involving an enzymatic reaction and a subsequent chemical reaction

We previously reported that an amide bond is unexpectedly formed1) by an acyl-CoA synthetase, AcsA, which plays an essential role in acid utilization in the nitrile-degrative pathway2). Although AcsA essentially catalyzes the formation of a carbon-sulfur bond (the ligation of an acid with CoA), it surprisingly synthesized N-acyl-l-cysteine when a suitable acid and l-cysteine are used as substrates. Furthermore, this unexpected enzyme activity was also observed for acetyl-CoA synthetase and firefly luciferase, both of which belong to the same superfamily of adenylate-forming enzymes. However, the mechanism underlying the carbon-nitrogen bond synthesis remained unknown. Next, we succeeded in producing N-(D-alanyl)-l-cysteine (a dipeptide) from D-alanine and l-cysteine by using DltA, which is homologous to the adenylation domain of nonribosomal peptide synthetase (NRPS) and belongs to the superfamily of adenylate-forming enzymes. To elucidate the mechanism of these surprising reaction, DltA was used. When cysteine derivatives with a protected amino group N-Boc-l-Cys was used instead of l-cysteine, we confirmed the formation of an thioester intermediate. Thereby, we proposed the following unprecedented reaction mechanism underlying these carbon-nitrogen bond synthetic reactions by the thioester-bond-synthesizing enzymes: (i) the formation of S-acyl-l-cysteine as an intermediate via its “enzymatic activity” and (ii) subsequent “chemical“ S→N acyl transfer in the intermediate, resulting in peptide formation3). Step (ii) of this reaction mechanism is identical to the corresponding reaction in native chemical ligation, a method of chemical peptide synthesis, whereas step (i) is not. We predicted that enzymes belonging to the superfamily of adenylate-forming enzymes can synthesize peptide/amide compounds by the same mechanism. Accordingly, we tried to express and purify DhbE, a stand-alone adebylation domain of NRPS, for production of valuable peptide/amide compounds. The purified DhbE synthesized N-aromatic acyl-l-cysteine4). Here, we reported the first demonstration of the N-acylation by “internal” adenylation domains in the multidomain enzyme DhbF. The adenylation domain of NRPS originally is responsible for its selective substrate recognition and activation of the substrate. DhbF is an NRPS involved in bacillibactin synthesis and consists of multiple domains (adenylation domain, condensation domain, peptidyl carrier protein domain, and thioesterase domain). DhbFA1 and DhbFA2 (here named) are “internal” adenylation domains in DhbF. Here, we firstly succeeded in expressing and purifying “internal” adenylation domain DhbFA1 or DhbFA2 separately. When glycine and l-cysteine were used as substrates of DhbFA1, the formation of N-glycyl-l-cysteine (Gly-Cys) was observed. When l-threonine and l-cysteine were used as substrates of DhbFA2, N-l-threonyl-l-cysteine (Thr-Cys) was formed. Furthermore, DhbFA1 or DhbFA2 synthesizes not only dipeptides but also various oligopeptides. Because many adenylation domains that could activate the respective substrates are present in the natural world, we can synthesize various peptides or amides by using adenylation domains or enzymes belonging to the superfamily of adenylate-forming enzymes. References: 1. Abe, T. et al., J. Biol. Chem. 283, 11312-11321 (2008). 2. Hashimoto, Y. et al., J. Biol. Chem. 280, 8660-8667 (2005). 3. Abe, T. et al., J. Biol. Chem. 291, 1735-1750 (2016). 4. Abe, T. et al., J. Antibiot. 70, 435-442 (2017)

The Bright Side and Dark Side of Workplace Social Capital: Opposing Effects of Gender on Overweight among Japanese Employees

Background: A growing number of studies have sought to examine the health associations of workplace social capital; however, evidence of associations with overweight is sparse. We examined the association between individual perceptions of workplace social capital and overweight among Japanese male and female employees. Methodology/Principal Findings We conducted a cross-sectional survey among full-time employees at a company in Osaka prefecture in February 2012. We used an 8-item measure to assess overall and sub-dimensions of workplace social capital, divided into tertiles. Of 1050 employees, 849 responded, and 750 (624 men and 126 women) could be linked to annual health check-up data in the analysis. Binomial logistic regression models were used to calculate odds ratios and 95% confidence intervals for overweight (body mass index: ≥25 kg/m2, calculated from measured weight and height) separately for men and women. The prevalence of overweight was 24.5% among men and 14.3% among women. Among men, low levels of bonding and linking social capital in the workplace were associated with a nearly 2-fold risk of overweight compared to high corresponding dimensions of social capital when adjusted for age, sleep hours, physiological distress, and lifestyle. In contrast, among women we found lower overall and linking social capital to be associated with lower odds for overweight even after covariate adjustment. Subsequently, we used multinomial logistic regression analyses to assess the relationships between a 1 standard deviation (SD) decrease in mean social capital and odds of underweight/overweight relative to normal weight. Among men, a 1-SD decrease in overall, bonding, and linking social capital was significantly associated with higher odds of overweight, but not with underweight. Among women, no significant associations were found for either overweight or underweight. Conclusions/Significance: We found opposite gender relationships between perceived low linking workplace social capital and overweight among Japanese employees

Potential Involvement of the Stem Cell Factor Receptor c-kit in Alopecia Areata and Androgenetic Alopecia: Histopathological, Immunohistochemical, and Semiquantitative Investigations

Alopecia areata (AAR) and androgenetic alopecia (AGA) are two major forms of alopecia based on altered hair growth condition. In general, the cell cycle is regulated by several mechanisms including the stem cell factor/c-kit signaling. To assess a role for stem cell activity in alopecia, we performed histopathological, immunohistochemical, and semiquantitative analyses of c-kit as well as Ki-67 in scalp biopsy specimens obtained from 14 patients with AAR, 18 patients with AGA, and 6 age-matched control subjects, using the specific antibodies. Formalin-fixed, paraffin-embedded skin sections were examined. Immunoreactivities for Ki-67 and c-kit were localized in keratinocytes and melanocytes in the outermost layer of hair follicles. The mean length of hair follicles was significantly shorter in the AAR and AGA groups than in the control group. The mean number of Ki-67-immunoreactive cells per follicle was significantly reduced in the AAR and AGA groups as compared with the control group. The mean number of c-kit-immunoreactive cells per follicle was significantly increased in the AAR and AGA groups as compared with the control group. Our results indicate that c-kit is upregulated in the hair follicle cells in these forms of alopecia, and suggest that the upregulation reflects a negative feedback mechanism in response to possible downregulation of the ligand stem cell factor

A Ring-structured Retrieval System for Moss Specimens

第2回極域科学シンポジウム/第33回極域生物シンポジウム 11月18日（金） 統計数理研究所 3階リフレッシュフロ

Direct Ink Write Printing of Chitin-Based Gel Fibers with Customizable Fibril Alignment, Porosity, and Mechanical Properties for Biomedical Applications

A fine control over different dimensional scales is a challenging target for material science since it could grant control over many properties of the final material. In this study, we developed a multivariable additive manufacturing process, direct ink write printing, to control different architectural features from the nano- to the millimeter scale during extrusion. Chitin-based gel fibers with a water content of around 1500% were obtained extruding a polymeric solution of chitin into a counter solvent, water, inducing instant solidification of the material. A certain degree of fibrillar alignment was achieved basing on the shear stress induced by the nozzle. In this study we took into account a single variable, the nozzle's internal diameter (NID). In fact, a positive correlation between NID, fibril alignment, and mechanical resistance was observed. A negative correlation with NID was observed with porosity, exposed surface, and lightly with water content. No correlation was observed with maximum elongation (similar to 50%), and the scaffold's excellent biocompatibility, which appeared unaltered. Overall, a single variable allowed a customization of different material features, which could be further tuned, adding control over other aspects of the synthetic process. Moreover, this manufacturing could be potentially applied to any polymer