• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2010년도 추계 학술발표회 3차
• /
• pp.37-46
• /
• 2010

Marine clays are soft soil deposits having complicated mineralogy and formation characteristics. Thus, characterization of its geotechnical behavior has been a main issue for geotechnical engineers. Nowadays, the importance and applications of geophysical exploration on marine clays are increasing significantly according to the accuracy, efficiency, and reliability of geophysical survey technology. For marine clays, seismic survey is effective for density and elasticity characterization, while electro-magnetic wave provides the information about the fluid conductivity phenomena inside soil. For practical applications, elastic wave technology can evaluate the consolidation state of natural marine clay layers and estimate important geotechnical engineering parameters of artificially reclaimed marine deposits. Electrical resistivity can provide geophysical characteristics such as particle cementation, pore geometry shape, and pore material phase condition. Furthermore, nondestructive geophysical monitoring is applicable for risk management and efficiency enhancement during natural methane gas extraction from gas hydrate-bearing sediments.

• Mycobiology
• /
• 제49권2호
• /
• pp.151-160
• /
• 2021

Despite recent studies, relatively few are known about the diversity of fungal communities in the deep Atlantic Ocean. In this study, we investigated the diversity of fungal communities in 15 different deep-sea sediments from the South Atlantic Ocean with a culture-dependent approach followed by phylogenetic analysis of ITS sequences. A total of 29 fungal strains were isolated from the 15 deep-sea sediments. These strains belong to four fungal genera, including Aspergillus, Cladosporium, Penicillium, and Alternaria. Penicillium, accounting for 44.8% of the total fungal isolates, was a dominant genus. The antiaflatoxigenic activity of these deep-sea fungal isolates was studied. Surprisingly, most of the strains showed moderate to strong antiaflatoxigenic activity. Four isolates, belonging to species of Penicillium polonicum, Penicillium chrysogenum, Aspergillus versicolor, and Cladosporium cladosporioides, could completely inhibit not only the mycelial growth of Aspergillus parasiticus mutant strain NFRI-95, but also the aflatoxin production. To our knowledge, this is the first report to investigate the antiaflatoxigenic activity of culturable deep-sea fungi. Our results provide new insights into the community composition of fungi in the deep South Atlantic Ocean. The high proportion of strains that displayed antiaflatoxigenic activity demonstrates that deep-sea fungi from the Atlantic Ocean are valuable resources for mining bioactive compounds.

• BMB Reports
• /
• 제41권11호
• /
• pp.796-802
• /
• 2008

Suppression subtractive hybridization (SSH) cDNA libraries of the giant tiger shrimp, Penaeus monodon, were constructed. In total, 178 and 187 clones from the forward and reverse SSH libraries, respectively, of P. monodon were unidirectionally sequenced. From these, 37.1% and 53.5% Expressed Sequence Tags (ESTs) significantly matched known genes (E-value < 1e-04). Three isoforms of P. monodon progestin membrane receptor component 1: PM-PGMRC1-s (1980 bp), PM-PGMRC1- m (2848 bp), and PM-PGMRC1-l (2971 bp), with an identical ORF of 573 bp corresponding to a deduced polypeptide of 190 amino acids, were successfully identified by RACE-PCR. Interestingly, PMPGMRC1 showed a greater expression level in testes of juvenile than broodstock P. monodon (P < 0.05). Dopamine administration ($10^{-6}$ mol/shrimp) resulted in up-regulation of PM-PGMRC1 in testes of juveniles at 3 hrs post treatment (P < 0.05), but had no effect on PM-Dmc1 (P > 0.05).

• Genes and Genomics
• /
• 제40권11호
• /
• pp.1213-1223
• /
• 2018

Pelagic larval dispersal habits influence the population genetic structure of marine mollusk organisms via gene flow. The genetic information of the clam Gomphina aequilatera (short larval stage, 10 days) which is ecologically and economically important in the China coast is unknown. To determine the influence of planktonic larval duration on the genetic structure of G. aequilatera. Mitochondrial markers, cytochrome oxidase subunit i (COI) and 12S ribosomal RNA (12S rRNA), were used to investigate the population structure of wild G. aequilatera specimens from four China Sea coastal locations (Zhoushan, Nanji Island, Zhangpu and Beihai). Partial COI (685 bp) and 12S rRNA (350 bp) sequences were determined. High level and significant $F_{ST}$ values were obtained among the different localities, based on either COI ($F_{ST}=0.100-0.444$, P<0.05) or 12S rRNA ($F_{ST}=0.193-0.742$, P<0.05), indicating a high degree of genetic differentiation among the populations. The pairwise $N_m$ between Beihai and Zhoushan for COI was 0.626 and the other four pairwise $N_m$ values were >1, indicating extensive gene flow among them. The 12S rRNA showed the same pattern. AMOVA test results for COI and 12S rRNA indicated major genetic variation within the populations: 77.96% within and 22.04% among the populations for COI, 55.73% within and 44.27% among the populations for 12S rRNA. A median-joining network suggested obvious genetic differentiation between the Zhoushan and Beihai populations. This study revealed the extant population genetic structure of G. aequilatera and showed a strong population structure in a species with a short planktonic larval stage.

• Natural Product Sciences
• /
• 제21권4호
• /
• pp.251-254
• /
• 2015

Recently, we reported violapyrones B, C, H and I, unusual 3, 4, 6-trisubstituted ${\alpha}-pyrones$ derivatives, from the culture broth of the marine Streptomyces sp. 112CH148. In previous studies, violapyrones have been shown to have antibacterial and antitumor activities. However, the anti-inflammatory effect of violapyrones has not been reported yet. As part of our ongoing study for the discovery of bioactive metabolites from marine microorganisms, we found that violapyrones also have anti-inflammatory activity. In this study, we investigated the effect of violapyrones on LPS-induced inflammatory responses in vitro. Violapyrones B and C did not affect the viability of RAW 264.7 cells at concentrations up to $25{\mu}M$. However, violapyrones B and C inhibited the production of NO compared to the LPS-induced control. In addition, violapyrones B and C down-regulated the expression of iNOS protein in LPS-stimulated RAW 264.7 cells. To the best of our knowledge, this is the first report on the anti-inflammatory activity of violapyrones B and C.

• 한국군사과학기술학회지
• /
• 제16권5호
• /
• pp.622-630
• /
• 2013

The purpose of this study is to investigate trends of characteristics and changes in the field of marine/naval/underwater military science and technology in Korea. This study analyzed the keywords that appeared in marine/naval/underwater section of the "Journal of the Korean Military Science and Technology" during the period, 1998~2012. One hundred and seven articles were analyzed by keywords in English. Four hundred and fifty four keywords in English were analyzed by appearance frequency. Finally those results of source literatures and keywords were compared with each other and a better direction for the future of the field with further studies was suggested.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
• /
• pp.942-942
• /
• 2006

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
• /
• pp.499-499
• /
• 2006

• 한국어업기술학회:학술대회논문집
• /
• 한국어업기술학회 2001년도 추계 수산관련학회 공동학술대회발표요지집
• /
• pp.145-146
• /
• 2001

Despite a variety of development in fish farming during the last decades, fish diseases by bacteria, virus, and parasites are still major problems in aquaculture. Aquaculture of Hounder fish is widely performed around Korea as well as Jeju island, due to relatively stable seed production, short farming period, and a higher value in market. However, intensive feeding and environmental pollution in aquacutural farm act as a great limiting factor in economic aspect. (omitted)

• 한국어업기술학회:학술대회논문집
• /
• 한국어업기술학회 2001년도 추계 수산관련학회 공동학술대회발표요지집
• /
• pp.151-152
• /
• 2001

Chitin, a polymer of N-acetylglucosamine ($\beta$-1,4 linked 2-acetamido-D-glucose), is a cellulose-like biopolymer present richly in the exoskeleton of crustaceans and in cell walls of fungi, insects and yeast. Chitosan is derived from chitin by deacetylation, to different degrees, in the presence of alkali. [l]. Recent studies for chitin and chitosan have been concentrated in bioactivities such as antitumor activity, immuno-enhancing effects, enhancing protective effects against infection with some pathogens in mice, and antimicrobial activeity [2]. (omitted)