• Journal of Microbiology and Biotechnology
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• v.22 no.3
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• pp.378-384
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• 2012

In aquatic invertebrates, particularly marine gastropods, organotin compounds induce irreversible sexual abnormality in females, which is termed imposex, at very low concentrations. Organotin compounds are agonists for nuclear receptors such as RXRs and $PPAR{\gamma}$. However, the imposex phenomenon has not been reported to act as an antagonist on estrogen receptors in other species, including vertebrates and invertebrates. In order to gain insights into the antagonistic activity of organotin compounds on estrogen receptors (ERs), we examined the inhibitive effect of these compounds on estradiol-dependent ${\beta}$-galactosidase activity using the yeast two-hybrid detection system consisting of a combination of the human estrogen receptor ($hER{\beta}$) ligand-binding domain and the co-activator steroid receptor co-activator-1 (SRC1). Tributyltin-hydroxide (TBT-OH) and triphenyltin-chlorine (TPT-Cl) exhibited an inhibitive effect on $E_2$-dependent transcriptional activity, similar to antagonistic chemicals such as 4-hydroxytamoxifen (OHT) or ICI 182,780, at a very low concentration of $10^{-14}$ M TBT or $10^{-10}$ M TPT, respectively. The yeast growth and transcriptional activity with transcriptional factor GAL4 did not exhibit any effect at the tested concentration of TBT or TPT. Moreover, the yeast two-hybrid system using the interaction between p53 and the T antigen of SV40 large did not describe any effect at the tested concentration of OHT or ICI 182,780. However, the interaction between p53 and T antigen was inhibited at a TBT or TPT concentration of $10^{-9}$ M, respectively. These results indicate that TBT and TPT act as inhibitors of ER-dependent reporter gene transcriptional activation and of the interaction between $hER{\beta}$ LBD and the co-activator SRC1 in the yeast two-hybrid system. Consequently, our data could partly explain the occurrence of organotin compound-induced imposex on the endocrine system of mammals, including humans.

• Korean Journal of Heritage: History & Science
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• v.52 no.3
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• pp.146-159
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• 2019

This study focuses on the understanding of human subsistence and pottery use during ancient times on the Korean peninsula through lipid analysis of potsherds from several major prehistoric settlement sites. Ancient human subsistence has been one of the long-standing topics in Korean archaeology. However, since the high acidity of sediments does not allow long-term preservation of organic remains, we still lack some critical information related to the prehistoric diet. Pottery contains relatively well-preserved organic remains created during past cooking events. Though pottery is one of the most studied material cultures in Korean archaeology, almost no attention has been given to analyzing the pottery itself. This is a surprising omission and represents a serious gap in our understanding of prehistoric technology and subsistence. The analysis of ancient lipids extracted from the pottery matrix using GC-MS and isotope analysis can contribute to our understanding of the true nature of past subsistence strategies. Potsherd samples for the analyses in this study were collected from six prehistoric and early historic settlement sites located in the central part of the Korean peninsula. The results showed that subsistence strategies differed by both location and time period. For example, at Jungdo, an inland open-air Bronze Age settlement site in Chuncheon City, we were able to see the presence of terrestrial mammals. At Gahak-dong, Gwangmyeong City, marine resources were utilized, as the location of the site is not far from the coastline. At the early historic site of Guwol-dong, Incheon City, we were able to detect dairy products. The results of this study suggest that there was utilization of a wider range of resources among ancient dwellers in the central part of the Korean peninsula.

• The Journal of the Acoustical Society of Korea
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• v.43 no.3
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• pp.314-323
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• 2024

Recently, a score-penalty method has been used for the acoustic passive tracking of marine mammals. The interesting aspect of this technique lies in the loss function, which has a penalty term representing the mismatch between the measured signal and the modeled signal, while the traditional time-domain matched-field processing is positively considering the match between them. In this study, we apply the score-penalty method into the depth estimation of a passive target with a known source waveform. Assuming deep ocean environments with uncertainties in the sound speed profile, we evaluate the score-penalty method, comparing it with the time-domain matched field processing method. We shows that the score-penalty method is more accurate than the time-domain matched field processing method in the ocean environment with weak mismatch of sound speed profile, and has better efficiency. However, in the ocean enviroment with strong mismatch of the sound speed profile, the score-penalty method also fails in the depth estimation of a target, similar to the time-domain matched-field processing method.