In Conversation Analysis (CA), laughter, which is treated as a systematically produced activity, has been investigated in connection with troubles. This paper examines initiating laughter in three writing tutoring sessions at a university writing center in Korea, deploying the method of CA. Laughter can be used in two ways in the dataset. Firstly, tutors can use laughter to mitigate their negative assessment about the studentʹs essay. Along with delays and mitigating expressions, laughter infiltrated in the assessment can mitigate the dispreferred nature of the negative assessment. Secondly, both tutors and students can display their talk or action as inappropriate through laughter. The tutor uses laughter when producing talk that can be treated problematic or accountable. The students join in the tutorʹs laughter, and this shared laughter mitigates the problematic nature of the tutorʹs talk. Students may similarly use laughter to display their awareness of the inappropriate nature of their talk or conduct, when responding to the tutorʹs questions. The analysis suggests that laughter can be associated with interactional troubles. The conclusion will include comparisons with other institutional contexts.
Autophagy is conserved response to starvation by which cells catabolize their components to create an internal supply of essential nutrients. Ceramide is known to induce autophagy in many cells through down-regulation of amino acid and glucose transporters. The mechanism of starvation induced-autophagy in mouse embryo remains unclear. In order to understand the mechanism by which starvation regulates autophagy, in this study, we investigated nutrient transporters expression and the effect of c2-ceramide on the in vitro development, apoptosis and autophagy via starvation in mouse embryo. Glucose transporters (Glut1 and Glut 3), high levels of transcript were expressed from 1 to 2 cells and gradually decreased through the morula and blastocyst (BL) stages. Amino acid transporters (LAT-1 and 4F2hc) gradually decreased from the zygote to the BL stage. Furthermore, the expression of nutrient transporters (Glut1, 3, LAT-1 and 4F2hc) were significantly reduced at the BL stage after ceramide treatment. Especially, mTOR expression after ceramide treatment of embryos was significantly higher than controls. Ceramide treated embryos exhibited significantly reduced developmental rates and total cell numbers, and increased apoptotic cell death at the BL stage. Consequently, we next evaluated the effect of ceramide treatment on mitochondrial number and morphology. There was a significant decrease in the average mtDNA copy number and the mitochondrial area in ceramide treated BL stage embryos. Both the expression of autophagy-related genes, Lc3, Gabarap, Atg4A and Atg4B, and the synthesis of LC3 were significantly induced at the BL stage. These results suggest that autophagy under starvation condition influences the in vitro development and apoptosis and autophagy, and may play a role in early mouse embryogenesis.
Autophagy is an evolutionarily conserved lysosomal pathway for degrading cytoplasmic proteins, macromolecules, and organelles, in addition to recycling protein and ATP synthesis. Although programmed cell death (PCD) is very important during embryogenesis, the mechanism underlying the dynamic development during this process remains largely unknown. In order to obtain insights into autophagy and it's relation with apoptosis in early embryo development, we first evaluated LC3 gene expression levels in mouse embryos developing in vitro. qRT-PCR revealed high expression levels from 1- to 4 cell stage embryo, and then expression decreased during morula and blastocyst formation. Indirect immunocytochemistry showed protein synthesis of LC3 in these stage embryos. Introducing of autophagy inhibitor, 3-MA (2mM) significantly decreased both developmental rate (54.85±11.0%) and total cell number (n=71±8), but increased apoptosis rate (5.68± 1.9%) at the blastocyst. Real time RT-PCR confirmed reduced expression of selected autophagy related genes, including ULK1, Atg4A, B, C, D, Atg5, Atg8, Gabarap, Atg9A, B and Atg16L. Treatment of autophagy inducer, rapamycin (50 ng/㎖) increased both mRNA expression and protein synthesis of LC3 and apoptosis rate (16.11±3.42%), but decreased developmental rates (50.16±9.78) and total cell numbers (n=60±7) as compared to control developmental rate (70.74±12.9%), Total cell number (89.8±9) and apoptotic cell death (1.11±0.7%). These results suggest that autophagy is related with apoptosis in mouse embryo, which possibly give a role for early development.
Four medicinal plants selected from preliminary screening study were evaluated in the aspects of their antioxidant activities in alcohol-intoxicated rats. Rats fed 1% α-tocopherol-supplemented diet as positive control and ones done α-tocopherol-deficient diet as negative control were compared with ones done the plant extract-supplemented diet (n=8). After the administration of the experimental diets for 4 weeks, typical increments in activities of manganese-superoxide dismutase (Mn-SOD) and glutathione peroxidase (GSH-px) indicated in alcohol-intoxicated rats, were not observed in ones fed Lagerstroemia and Ulmus extract-supplemented diet. The content of thiobarbituric acid reactive substance (TBARS), the product of lipid peroxidation, did not increased in rats fed plant extracts-supplemented diet except for Terminalia. From the results, it is concluded that Lagerstroemia and Ulmus have physiologically efficient antioxidant activities.