To investigate the tolerance limit and critical thermal maximum (CTM), behavioral responses of wild goldeye rockfish Sebastes thompsoni according to exposure to high water temperature were observed using a continuous behavior tracking system. As a result, behavioral index (BI) of S. thompsoni in each temperature (20.0, 25.0, and 30.0°C) showed a significant difference (p<0.05) when compared with the value measured in a stable condition of 15.0°C. The activity level of S. thompsoni exposed to 25.0°C decreased sharply after 20 hours. Their rest time at the bottom of experiment chamber increased, and their normal swimming and metabolic activities were disturbed. In addition, at a high water temperature of 30.0°C, S. thompsoni reached the limit of resistance and showed a sub-lethal reaction of swimming behavior, with energy consumption in the body increased and all test organisms died. In conclusion, the eco-physiological response of S. thompsoni to water temperature varied greatly depending on the fluctuation range of the exposed temperature and the exposure time. In addition, the tolerance limit of S. thompsoni to high water temperature was predicted to be 25.0- 30.0°C. The maximum critical thermal that had a great influence on the survival of this species was found to be around 30.0°C.

The present study examined the receptive and productive knowledge of collocations of second language (L2) and heritage speakers of Korean and also investigated the influence of phrasal frequency, exposure to Korean, and phonological short-term memory (PSTM). Seventeen L2 learners and 14 heritage speakers of Korean were tested on 30 Korean noun-verb collocations, which varied in phrasal frequency, using an acceptability judgment task and a collocation completion test. The results showed that both L2 and heritage speakers demonstrated considerable receptive knowledge of Korean collocations while productive knowledge was more limited for both groups. The mixed-effects modelling results of four independent variables of interest (i.e., phrasal frequency, exposure via media, academic use, and PSTM) showed that phrasal frequency was the only significant predictor of receptive knowledge of collocations for both L2 and heritage speakers; none of the four factors had a significant impact on productive knowledge of collocations for either group. These data are discussed in relation to previous studies on collocation development of L2 learners and heritage speakers.

This study is for evaluation and optimization of workers’ radiation exposure for dismantling Reactor Vessel (RV) at Kori unit 1 in connection with its decommissioning process for the purpose of establishing Radiation Safety Management Plan. This is because the safety of workers in a radiation environment is an important issue. The basis of radiological conditions of this evaluation is supposed to be those of 10 years after the permanent shutdown of Kori unit 1 when dismantling work of Reactor Vessel would suppose to be started. Dose rates of work areas were evaluated on the basis of spatial dose rate derived from activation level calculated by MCNP (Monte Carlo N-Particle Transport) and ORIGEN-S code. RV are radiated by neutrons during operation, creating an environment in which it is difficult for operators to access and work. Therefore, the RV must be dismantled remotely. However, due to work such as installing devices or dismantling surrounding structures, it is not possible to completely block the access of workers. Accordingly, the exposure of workers to the RV dismantling process should be assessed and safety management carried out. The dismantling process of Kori unit 1 RV was developed based on in-situ execution in atmospheric environment using the oxigen-propane cutting technology as the following steps of Preparation, Dismantling of Peripheral Structures, Dismantling of RV and Finishing Work. For evaluation of exposure of RV dismantling work, those processes of each steps are correlated with spatial dose rates of each work areas where the jobs being done. Results of the evaluation show that workers’ collective dose for RV dismantling work would be in the range of 536–778 man- mSv. The most critical process would be dismantling of upper connecting parts of RV with 170–256 manmSv while among the working groups, the expert group performing dismantling of ICI (In-core instrumentation) nozzles and handling & packaging of cut-off pieces is evaluated as the most significantly affected group with 37.5–39.4 man- mSv. Based on the evaluation, improvement plan for better working conditions of the most critical process and the most affected workers in terms of radiation safety were suggested.

최근 살진균제는 세계 식량 안보에 없어서는 안될 필수 요소이며, 그 사용량은 증가하고 있다. 살진균제는 직접적 또는 간접적으로 곤충에 영 향을 미쳐 유전자 및 분자 수준의 변화를 일으킨다. 곤충은 다양한 해독 매커니즘을 통해 살진균제를 포함한 농약으로부터 유발되는 활성산소 (ROS) 독성을 제거한다. 본 연구는 살진균제 캡탄의 비치명적 투여량(0.2, 2, and 20 μg/μL)을 주입 후 갈색거저리의 유충에서 해독효소의 mRNA 발현량을 분석했다. 갈색거저리의 전사체 분석을 통해 해독 매커니즘 관련 유전자인 퍼옥시다제(POX), 카탈라제(CAT), 슈퍼옥사이드 디스뮤타제(SOD) 및 글루타티온-S-트랜스퍼라제(GST)를 발굴하였다. 처리 24시간 후 TmPOX5 mRNA가 유의하게 증가한 것으로 나타났다. 처리 3 시간 후 TmSOD4의 mRNA가 유사하게 증가하였다. 또한 2 μg/μL 처리 24시간 후 TmCAT2의 mRNA 가 유의하게 증가하였다. 캡탄 노출 후 TmGST1 및 TmGST3의 mRNA 발현량도 증가하였다. 결론적으로, TmPOX5 및 TmSOD4 유전자는 갈색거저리에서 캡탄 노출에 대한 바이오마커 또는 생체이물 센서로 작용할 수 있음을 시사한다.

In this study, using a continuous behavior measurement technique, the short-term behavioral responses and tolerance limits of red seabream Pagrus major fingerlings to sudden exposure to low salinity in a controlled environment were observed. The activity of the fingerlings suddenly exposed to 21.4, 17.3, and 9.8 psu increased temporarily at the initial exposure to show irregular swimming behavior, but then recovered a stable activity pattern through rapid salinity adaptation. However, the organisms suddenly exposed to 7.3 and 4.3 psu could not withstand the salinity stress, and their swimming behavior was severely disturbed and all individuals died within 48 hours. The findings suggest that red seabream underwent a temporary salinity stress process at the beginning of the exposure to concentrations of 10.0 psu or higher. At these concentrations, osmotic control was possible within at least 11 hours, so stable metabolic activity was also possible. However, organisms suddenly exposed to concentrations below 5.0 psu exceeded the tolerance to low salinity and the sublethal limit. In red seabream exposed to this concentration range, severe behavioral and metabolic disturbances were observed, and death was observed due to osmotic control failure. In conclusion, a salinity range of 5.0 to 10.0 psu can be predicted to correspond to a concentration range in which the osmotic control ability of the red seabream fingerlings is lost, and sub-lethal reactions occur.

통상적으로 직업소음에 의한 청력손실을 최소화하기 위해서는 작업자가 8시간 동안 85 dBA 이상 소음에 노출되지 않도록 권고하고 있다. 이번 연구에서는 실습선박에서 7종류의 담당업무별 작업자들의 소음노출레벨을 측정하였다. 항해 중, 24시간 동안 작업자의 위치하는 A특성등가소음레벨(LAeq,i)과 소음장소의 지속기간(h) 및 소음기여도(Lex,24h,i)를 고려한 소음노출레벨(Lex,24h)을 측정하였다. 그 결과, 갑판사관 그룹 Lex,24h=56.1 dB, 갑판부원 그룹은 Lex,24h=58.9 dB, 실습항해사들은 Lex,24h=62.0 dB, 취사부원들은 Lex,24h=64.3 dB, 실습기관사그룹 은 Lex,24h=91.1 dB, 기관사관 그룹은 Lex,24h=91.1 dB, 그리고 기관부원 그룹은 Lex,24h=95.1 dB를 나타내고 있다. 따라서 기관 업무를 담당하는 기관사들, 기관부원들 그리고 기관실습생들은 반드시 청력보호구를 착용해야함을 알 수 있었다. 소음이 심한 기관실에서 청력보호구를 착용한다면 기관사관그룹은 Lex,24h=23.1 dB, 기관부원그룹은 Lex,24h=24.4 dB 그리고 기관실습생들은 Lex,24h=21.5 dB의 소음노출레벨을 줄일 수 있을 것으로 추정된다. 또한 실습생들의 거주구역인 제2 강의실 겸 식당구역에 바닥시공을 64 mm, A-60-class 뜬바닥 구조로 개선했다면 실습항해사들의 소음노출도는 Lex,24h=4.3 dB, 실습기관사들은 Lex,24h=1.8 dB 정도 추가적인 감소가 있었을 것이다.