• Journal of Embryo Transfer
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• v.32 no.3
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• pp.201-207
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• 2017

To increase the productivity of in vitro development, the antioxidants have been used for culture system of bovine oocytes and embryos. However, comparative studies on these molecules are rare and direct beneficial effects on blastocyst production cannot be discriminated for best results. The study was conducted to determine the influence of N-acetyl-L-cysteine (NAC), N-acetyl-L-cysteine amide (NACA), glutathione (GSH) and cysteamime (CYS) on maturation competence of COCs from GV to MII stage and productivity of blastocyst formation during in vitro fertilization and culture. There was no difference among maturation rates of oocytes to metaphase II with polar body with antioxidants for any of the treatment groups (p>0.05). However, the significant improvement on the rate of blastocysts ($32.3{\pm}5.0%$) was found in 0.1 mM CYS treatment than 0.3 mM NAC, 0.2 mM NACA or 0.5mM GSH (p<0.05). The addition of NAC ($18.8{\pm}3.7%$) or NACA ($21.2{\pm}3.9%$) did not improve development competence to morula and blastocysts than control ($24.4{\pm}4.1%$) and GSH ($26.5{\pm}5.0%$) (p>0.05). Our study showed that medium supplementation with CYS during IVM and IVC improved the rate of bovine embryo development but not with NAC, NACA and GSH addition.

• Korean Journal of English Language and Linguistics
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• v.4 no.1
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• pp.33-60
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• 2004

This study was an attempt to present an appropriate way of interpreting L2 learners' linguistic behavior within Universal Grammar (UG) framework. Based on the Korean EFL adult learners' performance on the Subjacency violation sentences, the study suggested that the EFL learners are able to acquire subtle knowledge of target grammar and their linguistic behavior should be interpreted with the most recent version of UG theory, the Minimalist Program (MP) notion. The MP notion seems more plausible to accommodate incomplete L2 grammar while acknowledging UG-constrained interlanguage which the previous version, Principles and Parameters (P&P) approach, could not explain very well. The study observed no age-effects among the Korean EFL learners in their linguistic competence measured by the performance on the UG-constraint violation sentences. Having suggested that the MP notion can be a more reasonable tool to explain the EFL learners' linguistic behavior, the study introduced comprehensive hypotheses such as Constructionist Model (CM) and the Ontogeny Phylogeny Model (OPM).

• English Language & Literature Teaching
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• v.15 no.4
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• pp.75-94
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• 2009

This study was designed to assess demotivation factors and compare the factor between two secondary school student groups. It furthermore examined how the factors related to students' L2 proficiency. A 31-item questionnaire was completed by 407 junior (JH) and senior high school (SH) students. Five factors were extracted through the principal axis factoring: Teachers' competence and teaching styles, Dissatisfaction with English classes and grading system, Difficulty of learning English, Lack of motivation and interest in learning English, and Inadequate learning contents. Although both JH and SH students did not perceive their English teacher as a strong attribution of demotivation, Difficulty of learning English and Dissatisfaction with English classes and grading system were the two strongest demotivating factors. When compared the overall mean scores of each factor between JH and SH groups, significant differences were found in all factors except Factor 4, with SH students reporting stronger demotivation. JH students attributed their demotivation to Difficulty of learning English, while SH students attributed that to Dissatisfaction with English classes and grading system. Both groups tended to attribute their demotivation to external forces. The study also showed that several demotivation factors related negatively to L2 proficiency.

• English Language & Literature Teaching
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• v.16 no.1
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• pp.41-59
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• 2009

The present study investigated Korean learners' knowledge on the range of possible interpretations of English locative PPs with manner of motion verbs, and considers whether learners can arrive at a superset L2 grammar on the basis of positive L2 input. Unlike Korean, some English locative PPs occurring with manner of motion verbs (such as in John jumped on the bed) are ambiguous as they can be interpreted as either directional or locational. Thirty Korean learners of English in three distinct groups (Advanced EFL-only group; Intermediate-EFL-only group; and ESL-experienced group) participated in an experimental study, along with a control group of nine native speakers of English. The results of the study showed that I) Korean learners, overall, tended to interpret English locative PPs as only locational, failing to recognize the ambiguity between the directional and locational readings in the target structure; 2) For the learners who experienced only the EFL context, even highly proficient learners, as well as intermediate level learners, failed to acknowledge the ambiguity; 3) The learners who experienced the ESL context for an extended period of time could identify the target reading to some extent, although they still could not reach the native-like competence. From these results, it is argued that robustness of positive evidence, not simply its availability, is critical in the acquisition of the superset L2 targets like the present one.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.357-366
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• 2017

This study was conducted to identify the diabetes self-care (DSM) knowledge, DSM competence, DSM behavior, and quality of life according to HbA1c control in diabetic elderly. The participants were 205 diabetes elderly who visited the citizen health promotion center located in D city, Korea. Data were collected from April, 4 to August 31 2015, and were analyzed by the t-test and chi-squared test using IBM SPSS 23.0. The mean scores of DSM knowledge, DSM competence, DSM behavior and quality of life were $50.61{\pm}16.39$, $71.27{\pm}10.21$, $62.78{\pm}1.29$ and $0.86{\pm}0.11$, respectively. Additionally, DSM behavior (t=2.17, p=0.031), education level (t=11.80, p=0.0019) l, BMI (t=0.001, p=0.012), and number of visits to citizen health center (t=16.497, p=0.001) differed significantly between the controlled HbA1c group and uncontrolled HbA1C group. However, ANCOVA revealed that the level of HbA1c did not affect the DSM behaviors. Therefore, it is necessary to develop and apply a DSM education program that reflects the characteristics knowledge level of the elderly. In addition, healthcare institutions with high accessibility in terms of distance and cost to guide and manage desirable diabetic self-care behaviors should be provided everywhere.

• Phonetics and Speech Sciences
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• v.13 no.1
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• pp.25-36
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• 2021

This study examined the perception and production of eight English fricatives /f/, /v/, /θ/, /ð/, /s/, /z/, /ʃ/, and /ʒ/ by thirty Chinese English majors and thirty Chinese middle school students through a fricative identification test, an intelligibility test, and a goodness rating test and focused on error patterns and the perception-production relationship. The results showed that substitution errors occurred frequently in the perception and production of English fricatives by both the English majors and the middle school students. Further, the error patterns were attributed to various influencing factors such as the negative transfer from Chinese consonant inventory, hypercorrection or overcompensation mistakes, deficiency of L2 teaching, and acoustic similarities. Significant overall correlations were found between the fricative perception and production by the two subject groups but were not manifested in all the eight fricatives, indicating that Chinese learners' perceptual competence of target fricatives was not necessarily tied to their productive excellence of those sounds in all cases. Furthermore, precedences of perception over production were incompletely manifested in the eight fricatives, which suggested that perception might not always be a necessary prerequisite for production. Additionally, subject group and vowel context differences were observed. The English majors performed better than the middle school students, both perceptually and productively, and the subjects' performances in perception and production varied when vowel contexts changed.

• International Journal of Contents
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• v.17 no.4
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• pp.62-78
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• 2021

This ethnographic multiple case study, based on Zappa-Hollman and Duff's construct of individual networks of practice (INoPs), explored English as a second language (L2) competence development and socialization process of a group of English-major undergraduates through their social connections and interactions at a public university located in an underdeveloped city in Northwest China. The study lasted for one academic semester and three students were selected as primary participants. Semi-structured interviews, student observations in English-related micro-settings, and associated texts were used to collect data. These data were coded to identify the thematic categories, and then data triangulation and member checking were conducted to select the most representative evidence to provide an in-depth description of students' perspective about mediating their English L2 socialization by their INoPs. Findings showed that factors in the formation of students' INoPs, including intensity, density, and nature, played significant roles in their academic or affective returns from their English learning, both of which had a substantial influence on the students' English L2 socialization. Considering that the macro-setting was a non-English, underdeveloped monolingual society, both educational institutions and individual students need to seek and create more English-mediated interactional opportunities to develop their English proficiency and adapt to local English learning communities.

• Korean Journal of Plant Tissue Culture
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• v.22 no.3
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• pp.143-148
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• 1995

The competence of callus formation and plant regeneration from root derived callus was higher in japonica cultivars than those of Tongil-type cultivars of rice. A japonica type cultivars Yeongdeogbyeo, showed the highest capacity (13%) for plant regeneration from root calli of 6 cultivars tested. The callus induced from seed and root tissues maintained higher capacity for plant regeneration during 7 passages of subculture on N$_{6}$ solid media at 2-week intervals. The maximum frequency (2 x 10$^{5}$ mL) of round cells and their cell colonies showed about 24 days after suspension culture of root-derived callus in N$_{6}$ medium with lmg/L 2,4-D, 300mg/L casein hydrolysate, 10mM L-proline, 20g/L sucrose and 30g/L sorbitol. The frequency of somatic embryo formation in suspension cultures of root-derived callus increased with prolonged advance of subculture time from 30 to 90 days, but their regenerative capacities decreased.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.9
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• pp.1245-1252
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• 2017

Objective: Phellodendron amurense (P. amurense) and Humulus japonicus (H. japonicus) are closely involved in anti-oxidative response and increasing antioxidant enzymes activities. However, the effects of their extracts on development of preimplantation bovine embryos have not been investigated. Therefore, we investigated the effects of P. amurense and H. japonicus extracts on developmental competence and quality of preimplantation bovine embryos. Methods: After in vitro fertilization, bovine embryos were cultured for 7 days in Charles Rosenkrans amino acid medium supplemented with P. amurense ($0.01{\mu}g/mL$) and H. japonicus ($0.01{\mu}g/mL$). The effect of this supplementation during in vitro culture on development competence and antioxidant was investigated. Results: We observed that the blastocysts rate was significantly increased (p<0.05) in P. amurense ($28.9%{\pm}2.9%$), H. japonicus ($30.9%{\pm}1.5%$), and a mixture of P. amurense and H. japonicus ($34.8%{\pm}2.1%$) treated groups compared with the control group ($25.4%{\pm}1.6%$). We next confirmed that the intracellular levels of reactive oxygen species (ROS) were significantly decreased (p<0.01) in P. amurense and/or H. japonicus extract treated groups when compared with the control group. Our results also showed that expression of cleaved caspase-3 and apoptotic cells of blastocysts were significantly decreased (p<0.05) in bovine blastocysts derived from both P. amurense and H. japonicus extract treated embryos. Conclusion: These results suggest that proper treatment with P. amurense and H. japonicus extracts in the development of preimplantation bovine embryos improves the quality of blastocysts, which may be related to the reduction of ROS level and apoptosis.

• Korean Journal of Plant Tissue Culture
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• v.24 no.6
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• pp.369-374
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• 1997

Immature flower buds of 'Desio' carnation were cultured on MS agar medium supplemented with 1 ㎎/L 2,L-D. Embryogenic calli were formed from 5-10% of the buds less than 20 ㎜ in length, but only non-embryogenic calli were produced from explants of shoot apex leaf, internode, and flowere buds larger than 20 ㎜. The same method was applied to 16 cultivars of cut Sower carnation and embryogenic calli were obtained in 7 cultivars. Several embryogenic callus lines were selected and maintained through subcultures over 120 weeks without loss of embryogenic competence. The embryogenic cultures were also proliferated rapidly in liquid agitation cultures using MS medium supplemented with 1mg/L 2,4-D. Numerous embryos were formed on the periphery of the cell aggregates upon transfer to auxin-free MS agar medium. Plantlets were transplanted in potting soil and grown to bloom in six months.