• Animal Systematics, Evolution and Diversity
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• v.39 no.4
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• pp.264-271
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• 2023

The edible jellyfish Rhopilema esculentum occurs in waters throughout northeastern Asia, including in Korea, China, and Japan. In Korean waters, R. esculentum has appeared in two regions (Gangwha and Muan). Based on the appearance of young medusae and coastal distribution records, these two regions may be key R. esculentum breeding sites. In the present study, we investigate and compare the genetic structure of R. esculentum in the two regions using mitochondrial sequences (16S ribosomal RNA and cytochrome c oxidase subunit I). The genetic diversity of the R. esculentum population at Ganghwa exceeded that of the population at Muan. Despite considerable geographic separation (400 km) between the two regions(Gangwha and Muan), our haplotype network suggests that the Gangwha and Muan populations of R. esculentum are related. The simple and monotonous genetic structure of the Muan population shows that R. esculentum emergence is relatively recent. In contrast, the Gangwha population shows evolution. Moreover, jellyfish of the Gangwha population are genetically diverse and remain constant despite environmental fluctuations in the Han River. The Gangwha area is considered to be the old origin of R. esculentum in Korea.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.43 no.4
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• pp.355-361
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• 2007

A giant jellyfish (Nemopilema nomurai), which is presumed developing in the East China Sea, is recently one of major issues in the Northeast Asia region due to its fatal damage to the fishery. The biomass estimates have generally been conducted by trawl sampling and sighting survey methods. The biological research is also needed to clarify such environmental origin or diurnal migration patterns. While trawl sampling or sighting survey methods are effective to investigate its density estimates in its distributed community of near bottom or surface, they have a problem in investigation on the vertical distribution of jellyfishes. In this case, an echo sounding detection would have an advantage to survey it more extensively and effectively. This trial was conducted to observe the vertical distribution of giant jellyfish, where thermocline strongly formed, during mooring at each station of the East China Sea and southern coastal area using acoustical and optical methods. By the results, they were observed to exit and move at the water column under the thermocline using the optical camera and echo sounder system, and the information was analyzed to find out the acoustical sound scattering characteristics relatives to 120kHz frequency. These results can be utilized effectively to estimate the vertical distribution and biomass of Giant jellyfish with comparing results from trawl sampling and sighting survey methods, hereafter.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.57 no.4
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• pp.351-364
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• 2021

In this study, the vertical distribution of giant jellyfish analyzed echo counting method and such survey methods as sighting and trawl were used to compare its density estimates. In May and July 2021, surveys were conducted in the East China Sea and the coastal waters of Korea. As a result, Nemopilema nomurai were evenly distributed in all water layers in East China Sea in May and July. When considered the correlation by each survey methods, it is possible to identify jellyfish in the surface area by sighting method and using sampling net; however, it has a low correlation with acoustic estimates due to marine environmental factor such as weather condition, wind and atmospheric pressure. Therefore, the result can be utilized by basic data when estimating jellyfish's distribution patterns and density estimates from each survey methods hereafter.

• BMB Reports
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• v.28 no.4
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• pp.323-330
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• 1995

Recent studies have shown that dopamine applied to cultured swimming motor neurons of Polyorchis penicillatus produces an inhibitory action by opening potassium channels through $D_2$-like receptors. In this study, it was demonstrated that dopamine found in the hydromedusa was not from exogenous sources and the content of dopamine depended on the $Ca^{2+}$ content of the dissecting media. In addition, a combination of thin layer chromatography and high performance liquid chromatography showed the presence of DOPA and DO PAC-like compounds in the jellyfish. The glyoxylic acid method for catecholamines suggested that a population of small cells, neither swimming motor neurons nor B-like neurons, had dopaminergic systems. From all these results, it is suggested here that DA synthesized from DOPA in some cells is released. being dependent on calcium concentrations, into a synaptic cleft and degraded into DOPAC after acting as an inhibitory transmitter to swimming motor neurons.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.10a
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• pp.215-218
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• 2009

In this paper, there analyzed the UV behavior and detection images due to corona discharge of insulators at 22.9kV. As the results, the shapes of UV detection images are jellyfish, sunflower, and amoeba type. Generally, the jellyfish and sunflower type appeared in air discharge. In surface discharge, Amoeba is generated. Also, there are classified 8 patterns such as sunflower A or B, jellyfish A or B, amoeba A, B, C, D. This method of the facilities assessment has an immediate effect in the field.

• Natural Product Sciences
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• v.18 no.1
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• pp.8-12
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• 2012

An anacardic acid analog (1) was isolated from the fungus Paecilomyces variotii which was derived from the giant jellyfish Nemopilema nomurai. Compound 1 was isolated from a natural source for the first time and was evaluated for antibacterial activity against human and marine pathogens, including MDR (multidrugresistant) strains. Compound 1 exhibited mild antibacterial activity against Escherichia coli DC 2, Streptococcus iniae, and methicillin-resistant Staphylococcus aureus 3089 (MRSA).

• Natural Product Sciences
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• v.19 no.1
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• pp.61-65
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• 2013

A bioassay-guided fractionation of the extract of the fungus Paecilomyces variotii, which was derived from the giant jellyfish Nemopilema nomurai, led to the isolation of antibacterial compounds viriditoxin and its monomeric subunit semi-viriditoxin. Viriditoxin showed significant antibacterial activity against several marine fish and human pathogens including MDR strains. Significant potencies against resistant pathogens such as VRE Enterococcus faecium, VRE Enterococcus faecalis, and MRSA were highly interesting. Viriditoxin also showed notable antibacterial activity against the fish pathogen Streptococcus iniae. Its potency was over 100-fold higher than oxytetracycline which is employed as a general antibiotic for aquaculture.

• Journal of Communications and Networks
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• v.8 no.3
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• pp.339-350
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• 2006

Several novel concepts and tools have revolutionized our understanding of the Internet topology. Most of the existing efforts attempt to develop accurate analytical models. In this paper, our goal is to develop an effective conceptual model: A model that can be easily drawn by hand, while at the same time, it captures significant macroscopic properties. We build the foundation for our model with two thrusts: a) We identify new topological properties and b) we provide metrics to quantify the topological importance of a node. We propose the jellyfish as a model for the inter-domain Internet topology. We show that our model captures and represents the most significant topological properties. Furthermore, we observe that the jellyfish has lasting value: It describes the topology for more than six years.

• Bulletin of the Korean Chemical Society
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• v.31 no.12
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• pp.3803-3805
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• 2010

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.2
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• pp.153-162
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• 2016

In this study, we investigated the moisturizing effects of collagen extract from jellyfish. The mositurizing effects were measured by the caspase 14 expression, filaggrin, hyaluronan synthase-3 (HAS-3), aquaporin-3 (AQP-3) and desmocollin (DSC). As a results, effect of caspase 14 mRNA expression of collagen extract are similar to that of retinoic acid (RA) which is a reference control. And the collagen extract showed inhibitory of filaggrin, HAS-3, AQP-3 and DSC mRNA expression of 211.7%, 139.9%, 212.5% and 116.8% respectively, at the concentration of 2%. Therefore, our study suggested that jellyfish collagen extract has considerable potential as a cosmetics ingredient with moisturizing effect.