• 농약과학회지
• /
• 제16권2호
• /
• pp.187-193
• /
• 2012

내분비계 장애 추정물질로 알려진 alachlor의 어류 생체내 호르몬에 미치는 영향을 검색하고자 송사리를 이용한 급성독성, 수중 분해성 및 단기번식독성시험을 수행하였다. 시험결과 96시간 $LC_{50}$은 2.37(1.994~2.805) mg/L 이었으며, 수중 분해성이 15일에 초기 처리농도에 비해 20% 정도 분해되었으므로 단기번식독성시험의 시험용수 교체는 매 7일로 하였다. 송사리를 이용한 21일 단기번식시험의 노출농도는 용매대조군, alachlor(0.02, 0.04, 0.11, 0.27, 0.68ppm)처리군, 양성 대조군($17{\beta}$ estradiol, 0.01, 0.1, 0.5ppb)을 두어 수행한 결과 산란 수는 대조군에 비해 최고투여 농도에서 47.9% 감소하였고, 유정란 율은 47.8% 감소하였다. 기형율도 부분적으로 농도 의존성 경향이 관찰되었다. 또한 내분비계 장애성 중 에스트로겐 영향을 검색할 목적으로 어체내 vitellogenin 농도 변화를 조사한 결과 유의성이 나타나지 않았으므로 alachlor는 vitellogenin성 에스트로겐은 아닌 것으로 판단되었다.

• 한국소음진동공학회논문집
• /
• 제14권12호
• /
• pp.1279-1286
• /
• 2004

This paper continues companion paper, part I : measurement and analysis. As shown in companion Paper, information and energy in monaural signal is quite different from that of binaural signal. In this paper, difference between monaural and binaural signal of transportation noise are investigated in subjective response test. We executed hearing screening test before giving a subject response test and excluded subjects who had physical hearing loss. An annoyance response test was conducted using headphone to avoid cross-talk effect in binaural testing. Percentage of highly annoyed under binaural signal reproduction is higher than percentage of highly annoyed under monaural signal reproduction. Result implies binaural reproduction technique is proper for a study of human response to short-term noise exposure in a headphone simulated-environment.

• 한국환경과학회지
• /
• 제16권4호
• /
• pp.425-432
• /
• 2007

The water flea has been used as a test organism of toxicity test for surface water. Toxicity test with water flea is categorized into two parts. One is acute toxicity test with observing immobility and mortality and the other is chronic toxicity test determined by survival and reproduction of water flea. Heartbeat measurement of water flea was designed as a short-term toxicity test in this study. Direct measurement of heartbeat under microscope by aid of video camera gives and early diagnosis of mortality in short time. Therefore, the effects of measuring illumination, measuring time, and non-feeding during the test on heartbeat of water flea was evaluated to establish a new test approach. Test organisms used in this study are Daphnia magna, a well standardizes toxicity test organism, and Simocephalus mixtus, a newly refined organism $IC_{50}$ values of these test organism by heartbeat measurement were compared and discussed. It was found that toxicity test by heartbeat measurement was a reproducible, easy and simple method accomplished in a few hours.

• 한국발생생물학회지:발생과생식
• /
• 제27권4호
• /
• pp.213-220
• /
• 2023

Previously, we showed that a chronic-low-dose nonylphenol (NP) exposure resulted in histological changes with sexually dimorphic pattern in rat adrenal glands. We hypothesized that such structural changes are closely related to the hormonal secretory patterns. To test this hypothesis, we developed the short-term adrenal incubation method, and measured the levels of catecholamines and cortical steroids using the high-performance liquid chromatography with electrochemical detection (HPLC-ECD) and specific enzyme-linked immunosorbent assay, respectively. The norepinephrine (NE) levels in media from NP-treated female adrenal, except 100 pM NP, were significantly increased [control (CTL) vs 1 nM NP, p<0.001; vs 10 nM NP, p<0.05; vs 100 nM NP, p<0.001; vs 1 µM NP, p<0.01]. The NE secretion from male adrenal was higher when treated with 100 nM and 1 µM NP (CTL vs 100 nM NP, p<0.05; vs 1 µM NP, p<0.05, respectively). The aldosterone level in the female adrenal media treated with 100 pM NP was significantly decreased, on the other hand, that of media treated with 10 nM NP was significantly increased (CTL vs 100 pM NP, p<0.05; vs 10 nM NP, p<0.01). In male adrenal media, the aldosterone levels of 10 nM, 100 nM and 1 µM NP-treated media were significantly declined (CTL vs 10 nM NP, p<0.001; vs 100 nM NP, p<0.001; vs 1 µM NP, p<0.001). These results showed the NP treatment altered secretory pattern of aldosterone from adrenals of both sexes, showing sexual dimorphism. It may be helpful for understanding possible adrenal pathophysiology, and endocrine disrupting chemicals-related sexually dimorphic phenomena in adrenals.

• 한국기후변화학회지
• /
• 제5권4호
• /
• pp.277-284
• /
• 2014

Biochar application to soil is widely known to have effects of climate change mitigation and soil quality improvement. However, effects of biochar on soil ecosystem are not always positive and some biochars are reported to contain toxic materials which might influence soil ecosystem. In this context, this study aims to investigate behavioral changes of earthworms(Eisenia fetida, Eisenia andrei) in response to different application rates of biochar to artificial soil. Treatment included two types of biochars made from rice husk (RH_Char) and wastewater sludge (SL_Char) with 1% and 10% application rates, respectively. Avoidance test revealed that earthworms did not avoid SL_Char treatments at 1% and 10%, while they rather moved to the RH_Char treatments probably due to higher labile carbon content(Hot water extractable carbon) of the RH_Char. The HWC content of RH_Char was 4 times higher than that of the SL_Char. Results of reproduction test showed that the survival rates, number of juveniles and number of cocoons were not influenced by biochar application except for the treatment of SL_Char at 10% rate. In the SL_Char 10% treatment, fatality was approximately 3.3 times as high as the control and the number of cocoons was 1.3 times higher in the same treatment than the control, indicating that earthworms were under environmental stress. The possible explanation for the stress condition was related to higher Cd, Ni, Cr, and As contents in the SL_Char. Overall results imply that biochar application at low rate might not change earthworms' behavior for the short term, while the reproduction behavior might be negatively influenced under the high application rate.

• 인간행동과 음악연구
• /
• 제1권1호
• /
• pp.1-10
• /
• 2004

음악 활동에 참여하기 위해서는 기본적인 인지기능을 필요로 하는데, 이는 학습에 필요한 기능과도 공통점을 가진다. 음악을 듣고 기억하는 데에 복합적인 의식 활동이 요구되며, 일련의 소리 자극들이 음악으로서 의미를 갖고 기억되기 위해서는 주어진 소리 정보에 내재해 있는 특징들을 지각하고 처리할 수 있는 기능이 요구된다. 여러 선행 연구에서는 음악활동을 통해서 기본적인 학습 기능이 강화될 수 있다는 결과를 제시하였다. 본 연구는 학습부진 아동들이 청각정보처리기술과 단기기억력 강화를 중심으로 구성된 음악치료 세션에 참여하였을 때 음악 활동과 학습에 필요한 인지기능에 향상이 있는지를 보고자 하는 데에 그 목적이 있다. 본 연구에서는 음악 활동 내에서 다루어지는 인지기능을 사정할 수 있는 척도를 개발하여 학습기술 증진을 위한 음악치료 프로그램을 실행 전 후에 각각 실시하였다. 음악인지기술척도(Music Cognitive Skills Test)는 청각 지각인지력과 단기기억력 측정을 중심으로 모두 5 항목으로 구성되어 있는데, 1) 리듬 모방력, 2) 선율 모방력, 3) 음고 구별력, 4) 동화음 구별력, 5) 음보존력으로 구성되어 있다. 본 연구에는 기초학력기능검사 결과를 중심으로 담임교사가 추천한 18명의 초등학교 4, 5, 6학년 학생들이 참여하였으며, 4 개월간 주 2회씩 음악치료 프로그램이 투입되었다. 연구 결과, 리듬 모방력과 선율 모방력은 사후 검사에서 통계적으로 유의미한 차이가 있었다. 그 외에 음고 구별력, 동화음 구별력, 그리고 음보존력에서는 사후검사에서 증가된 결과를 보여주었다. 결과와 함께 본 연구에서는 참여자들이 수행한 시험을 통해서 나타낸 공통점을 분석한 결과 선율모방 보다 리듬모방에서 더 높은 결과를 보여주었다. 이는 리듬이 시간적인 개념만을 다루지만, 선율은 이외에 공간적인 개념이 추가된 것이기 때문에 더 난이도가 높은 작업이라고 분석될 수 있다. 선율 모방에서는 공통적으로 특정 음역에서 어려움을 보였는데, 4도 이상의 음역이 제시되었을 때와 2도의 음역을 가지고 있는 경우는 동일한 음으로 지각되는 경우가 많았다. 이러한 연구결과는 제시된 청각적 정보를 의미있는 단위로 구분하고 이를 이해하고, 기억하여 재생산해내는 작업은 모방은 물론, 음의 구별과 보존에도 필요한 기술임으로, 체계적으로 구성된 음악활동은 이러한 인지기술들을 강화시켜 줄 수 있는 전략으로 활용될 수 있다는 점을 시사한다.

• Toxicological Research
• /
• 제26권1호
• /
• pp.67-74
• /
• 2010

The present study was conducted to obtain information on the effects of amitraz on reproductive and developmental parameters in rats. The test chemical was administered via the drinking water containing 0, 40, 120, and 360 ppm to male rats from 2 weeks before mating to the end of 14-day mating period and to females from 2 weeks before mating, throughout mating, gestation and up to lactational day 4. During the study period, clinical signs, body weights, food intake, organ weights, reproductive and littering findings, necropsy findings, sperm parameters, and histopathology were examined. At 360 ppm, decreases in the body weight gain, food consumption, and the number of live pups and an increase in the post-implantation loss were observed. In addition, decreases in the seminal vesicle weight and sperm motility were found in males. At 120 ppm, a decrease in the food consumption was found transiently in both males and females, but no reproductive and developmental toxicity was observed in both sexes. There were no signs of either general or reproductive and developmental toxicity in the 40 ppm group. Based on these results, it was concluded that the repeated oral administration of amitraz to rats resulted in a decrease in the food consumption at 120 ppm and decreases in the seminal vesicle weight, sperm motility, and the number of live pups and an increase in the post-implantation loss at 360 ppm in rats. Under these experimental conditions, the no-observed-adverse-effect level (NOAEL) of amitraz for general and reproduction/developmental toxicity was believed to be 120 ppm, and the no-observed-effect level (NOEL) of amitraz was believed to be 40 ppm in rats.