• Korean Journal of Environmental Biology
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• v.39 no.2
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• pp.147-155
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• 2021

To investigate the incidence of plant-parasitic nematodes (PPNs) in perilla fields in Korea, 55 soil samples were collected from open fields and plastic-film house fields and were analyzed during January 2020 to October 2020. Root-lesion nematodes (RLNs), spiral nematodes, root-knot nematodes, and stunt nematodes were detected in perilla fields, and the incidences of RLNs (39%) and spiral nematodes (55%) were higher than those of other nematodes. Among PPNs, RLNs are very important species found on economic crops. The detection frequency of RLNs was increased due to continuous crop cultivation, and the frequency of fields that cultivated only one crop continuously for over 11 years was twice higher than the frequency of fields that cultivated only one crop for less than 5 years. The PPN species diversity and density were different between leaf-perilla cultivation fields and seed-perilla cultivation fields. In phylogenetic analysis of RLNs, Pratylenchus penetrans, P. vulnus, and Pratylenchoides leiocauda were identified in perilla fields. These results suggest the RLNs should be considered for establishing nematode management strategies in perilla fields in Korea.

• Animal Bioscience
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• v.34 no.4
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• pp.546-557
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• 2021

Objective: If fertilization does not occur within a specific period, the quality of unfertilized oocytes in the oviduct (in vivo aging) or in culture (in vitro aging) will deteriorate over time. Icariin (ICA), found in all species of Epimedium herbs, has strong antioxidant activity, and is thought to exert anti-aging effects in vitro. We asked whether ICA protects oocytes against age-related changes in vitro. Methods: We analyzed the reactive oxygen species (ROS) levels and expression of antioxidant, maternal, and estrogen receptor genes, and along with spindle morphology, and the developmental competence and quality of embryos in the presence and absence of ICA. Results: Treatment with 5 μM ICA (ICA-5) led to a significant reduction in ROS activity, but increased mRNA expression of glutathione and antioxidant genes (superoxide dismutase 1 [SOD1], SOD2, peroxiredoxin 5, and nuclear factor erythroid 2-like 2), during aging in vitro. In addition, ICA-5 prevented defects in spindle formation and chromosomal alignment, and increased mRNA expression of cytoplasmic maturation factor genes (bone morphogenetic protein 15, cyclin B1, MOS proto-oncogene, serine/threonine kinase, and growth differentiation factor-9). It also prevented apoptosis, increased mRNA expression of antiapoptotic genes (BCL2-like 1 and baculoviral IAP repeat-containing 5), and reduced mRNA expression of pro-apoptotic genes (BCL2 antagonist/killer 1 and activation of caspase-3). Although the maturation and cleavage rates were similar in all groups, the total cell number per blastocyst and the percentage of apoptotic cells at the blastocyst stage were higher and lower, respectively, in the control and ICA-5 groups than in the aging group. Conclusion: ICA protects oocytes against damage during aging in vitro; therefore, it can be used to improve assisted reproductive technologies.

• The Korea Journal of Herbology
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• v.33 no.4
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• pp.59-67
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• 2018

Objectives : Ojeoksan, originally recorded in an ancient Korean medicinal book named "Donguibogam" and has been used for the treatment of circulation disorder of blood which was called blood accumulation (血積) in Korean medicine. Therefore, this study was carried out to investigate the beneficial effect of OJS on vascular inflammation in HUVECs. Methods : We evaluated the effect of OJS on the expression of cell adhesion molecules and protective role in HUVEC stimulated by TNF-${\alpha}$ by using Western blot. Results : Pretreatment with OJS decreased the adhesion of HL-60 cells to TNF-${\alpha}$-induced HUVEC. OJS suppressed TNF-${\alpha}$-induced expression level of cell adhesion molecules such as intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1(VCAM-1), and endothelial cell selectin (E-selectin). Moreover, OJS significantly decreased TNF-${\alpha}$-induced production of intracellular reactive oxygen species (ROS); and inhibited the phosphorylation of $I{\kappa}B-{\alpha}$ in the cytoplasm compared to the experimental group. Pretreatment with OJS inhibited the trans-location of NF-${\kappa}B$ p65 to the nucleus. OJS also inhibited phosphorylation of MAPKs compared to the experimental group. OJS significantly increased the protein expression of Nrf2 and HO-1. Conclusions : Ojeoksan has a protective effect on vascular inflammation, and might be a potential therapeutic agent for early atherosclerosis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.6
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• pp.777-790
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• 2022

This study was conducted to investigate the nutritional characteristics of the following Korean-distributed fish species commonly consumed as sliced raw fish (CC-SRF): olive flounder Paralichthys olivaceus (OF), red sea bream Pagrus major (RS), Atlantic salmon (AS), coho salmon (CS) and sockeye salmon (SS). The crude protein and lipid contents of OF, RS, AS, CS and SS were 20.2% and 5.5%, 21.2% and 6.8%, 17.7% and 18.5%, 18.3% and 16.1%, and 20.4% and 5.7%, respectively. Regardless of the type and weight of fish species, the major amino acids were leucine, lysine, aspartic acid, and glutamic acid, whereas histidine was identified as a limiting amino acid. The major minerals in all CC-SRF were P, K and Se based on the recommended daily intake or sufficient intake for Korean males aged between 19-49 years. Among the different types of all CC-SRF, the intake of OF and SS lipids is predicted to be associated with a lower n-6/n-3 fatty acid ratio, whereas among the free amino acids, which are expected to have health functionality, we identified taurine in OF and RS, and anserine in salmons. The digestibility of OF, RS, AS, CS and SS were 60.7%, 54.9%, 48.5%, 49.6%, and 53.4%, respectively.

• ALGAE
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• v.37 no.2
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• pp.149-161
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• 2022

Noctiluca scintillans is a heterotrophic dinoflagellate that causes red-colored oceans during the day (red tides) and glowing oceans at night (bioluminescence). This species feeds on diverse prey, including phytoplankton, heterotrophic protists, and eggs of metazoans. Thus, many scientists have conducted studies on the ecophysiology of this species. It is easy to cultivate N. scintillans at a scale of <1 L, but it is difficult to cultivate them at a scale of >100 L because N. scintillans cells usually stay near the surface, while prey cells stay below the surface in large water tanks. To obtain mass-cultured N. scintillans cells, we developed an automatic system for cultivating N. scintillans on a scale of 100 L. The system consisted of four tanks containing fresh nutrients, the chlorophyte Dunaliella salina as prey, N. scintillans for growth, and N. scintillans for storage, respectively. The light intensities supporting the high growth rates of D. salina and N. scintillans were 300 and 20 µmol photons m^-2 s^-1, respectively. Twenty liters of D. salina culture from the prey culture tank were transferred to the predator culture tank, and subsequently 20 L of nutrients from the nutrient tank were transferred to the prey culture tank every 2 d. When the volume of N. scintillans in the predator culture tank reached 90 L 6 d later, 70 L of the culture were transferred to the predator storage tank. To prevent N. scintillans cells from being separated from D. salina cells in the predator culture tank, the culture was mixed using an air pump, a sparger, and a stirrer. The highest abundance of N. scintillans in the predator culture tank was 45 cells mL^-1, which was more than twice the highest abundance when this dinoflagellate was cultivated manually. This automatic system supplies 100 L of N. scintillans pure culture with a high density every 10 d for diverse experiments on N. scintillans.

• Korean Journal of Ecology and Environment
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• v.55 no.4
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• pp.294-304
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• 2022

This study carried out from March 2021 to October 2021 in the upper part (St. 1) and middle part (St. 2) section of Yongsu stream, a branch of the Geum river, using PIT telemetry to understand the movement patterns and habitat characteristics of Odontobutis interrupta, a Korean endemic species. O. interrupta collection was used kick net (5×5 mm) and fish trap (5×5 mm). After collecting fish, PIT tag insertion was performed immediately in the site. Reader (HPR Plus Reader, biomark, USA) and portable Antenna (BP Plus Portable Antenna, biomark, USA) were used for detection of fish to monitoring the tagged O. interrupta. As a result of PIT telemetry applied to 70 individuals, mean movement distance was 36.5 (SE, ±6.6) m. There was a significant difference between total length and movement distance (P≤0.05). O. interrupta was mainly identified in average water depth, 36.2±1.9 cm, average water velocity, 0.03±0.07 m s^-1 and average distance from watershed, 4.4±0.3 m. Extent of rock used for habitat was varied from 32 to 4,000 cm². There was no statistical difference between the area of the first selected rock and the area of the after selected rock (P>0.05). but there was significant difference between total length and the area of the rock except for detection before 24 hours (P<0.01). Therefore, to restore the habitat, it is considered necessary to create various substrate structures by providing various habitat environments (water depth, flow rate, stone, etc.) for each individual size.

• Journal of Marine Life Science
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• v.1 no.1
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• pp.8-17
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• 2016

The family Pristiophoridae belonging to the order Pristiophoriformes consists of about 8 species and 2 genera in the world. Among them, only one species (Pristiophorus japonicus) is distributed in northwestern Pacific. The family is characterized by having an elongated and flattened rostrum with laterally projecting a low of sharp teeth. In order to clarify variability of local populations of P. japonicus, we investigated 16 individuals collected from four locations (Korea, n=6; Miyagi, n=1; Kochi Pref., n=1; Okinawa, n=8) for morphological and molecular analyses. Morphological analysis showed that there may exist three morphotypes, of which A morphotype (Korea, Miyagi, Kochi Pref.) has a short snout (26.8% of TL), being most similar to syntypes of P. japonicus. On the other hand, B morphotype (Okinawa) has a long (31.7% of TL) and wider snout (snout width at nostrils 5.2 times pre-oral length) and, C morphotype (Okinawa) has a long (31.7% of TL) and narrower snout (6.3 times). Molecular analysis using mitochondrial DNA cytochrome b DNA sequences (386 base pairs) showed that the K2P distance between A and C morphotypes were 2.1~2.7%, but those within A morphotype were 0.0~0.5%. We identified A morphotype as P. japonicus, and designated B and C morphotypes as Pristiophorus sp. 1 and Pristiophorus sp. 2, respectively. Further studies are required to elucidate the taxonomic status of two morphotypes of the sawshark in Okinawa.

• ALGAE
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• v.38 no.1
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• pp.57-70
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• 2023

The mortality rate of red-tide dinoflagellates owing to predation is a major parameter that affects their population dynamics. The dinoflagellates Ansanella granifera and Ansanella sp. occasionally cause red tides. To understand the interactions between common heterotrophic protists and A. granifera, we explored the feeding occurrence of nine heterotrophic protists on A. granifera and the growth and ingestion rates of the heterotrophic dinoflagellate Gyrodinium dominans on A. granifera as a function of prey concentration and those of Oxyrrhis marina at a single high prey concentration. The heterotrophic dinoflagellates Aduncodinium glandula, G. dominans, Gyrodinium moestrupii, Luciella masanensis, Oblea rotunda, O. marina, Polykrikos kofoidii, and Pfiesteria piscicida and the naked ciliate Strombidium sp. were able to feed on A. granifera. With increasing mean prey concentrations, the growth and ingestion rates of G. dominans feeding on A. granifera rapidly increased and became saturated or slowly increased. The maximum growth and ingestion rates of G. dominans on A. granifera were 0.305 d^-1 and 0.42 ng C predator^-1 d^-1 (3.8 cells predator^-1 d^-1), respectively. Furthermore, the growth and ingestion rates of O. marina on A. granifera at 1,700 ng C mL^-1 (15,454 cells mL^-1) were 0.037 d^-1 and 0.19 ng C predator^-1 d^-1 (1.7 cells predator^-1 d^-1), respectively. The growth and ingestion rates of G. dominans and O. marina feeding on A. granifera were almost the lowest among those on the dinoflagellate prey species. Therefore, G. dominans and O. marina may prefer A. granifera less than other dinoflagellate prey species. The low mortality rate of A. granifera may positively affect its bloom formation.

• Korean Journal of Plant Resources
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• v.36 no.4
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• pp.314-340
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• 2023

Vascular plants of Yeonhwasan Mt., located in Taebaek-si, Gangwon-do, were investigated. Field surveys were conducted fourteen times between April and September of 2022. A total of 505 taxa were found consisting of 87 families, 282 genera, 441 species, 15 subspecies, 41 varieties, and 8 forma. Among them, the endemic plants of Korea were 22 taxa. The number of threatened and near threatened Red List plants designated by the Korean National Arboretum was four, comprising each one of critically endangered (CN), endangered (EN), vulnerable (VU), and near threatened (NT) species. The number of floristic target plants designated by the Ministry of Environment was 102, including one taxon of level V, 9 taxa of level IV, and 34 taxa of level III. Invasive alien plants were 34 taxa, and three taxa were ecosystem disturbance plants. The urbanization index of investigated site was 12.8%, and the naturalization index was 6.7%. To wisely manage Yeonhwasan, measures for preserving biodiversity and preventing invasive plants are needed.

• Korean Journal of Ichthyology
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• v.35 no.1
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• pp.50-56
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• 2023

This study is the first to report the biometric information between the length and weight relationships (LWR) and seasonal body condition factors (K) of Sebastes zonatus Chen & Barsukov, 1976 and Thamnaconus modestus (Günther, 1877) inhabiting the waters off Ulleung-do and Dokdo. The LWRs in spring and summer, and all seasons combined were highly correlated (r²>0.959), and the regression slopes of LWRs were significantly different between the spring and summer in both species. The body conditions of the two fish were significantly higher during the spring than during the summer, reflecting their fatness in relation to spawning. The results from this study contribute to the understanding of the biology of S. zonatus and T. modestus and provide useful data for the development of conservation and management plans for these species.